CN1089065C - Ink tank, inkjet recording head, and inkjet recording system using ink tank - Google Patents

Abstract

The present invention provides an ink tank, an ink jet recording head and an ink jet recording system using the ink tank. The liquid tank, for containing printing liquid to be supplied to a recording head for an inkjet recording apparatus, includes: a first chamber containing a negative pressure generating material, having an air hole communicable with ambient air and a printing liquid supply port , to allow the printing liquid to be supplied to the recording head; a second chamber, which provides a printing liquid storage chamber for the first chamber, communicates with the first chamber through a communication port communicating with the first chamber, allowing the printing liquid to flow into the first chamber One cavity, and allows air to be introduced from the first cavity to the second cavity, wherein the second cavity includes a replaceable printing liquid cavity.

Description

Ink tank, inkjet recording head, and inkjet recording system using ink tank

This application is a divisional application of No. 93117093.1 patent application.

The present invention relates to an ink tank containing ink supplied to an ink jet recording head, ink, and an ink jet recording apparatus using the ink tank.

An ink tank used with an inkjet recording device supplies an appropriate amount of ink according to the amount of ink ejected by the recording head during recording, and at the same time prevents ink from leaking through the ejection port of the recording head when recording is not performed.

When the ink tank is in a replaceable form, it is required that the ink tank can be easily disassembled from the recording device without ink leakage, and that the ink can be reliably supplied into the recording head.

A common example of an ink tank that can be used in conjunction with an inkjet recording device is Japanese Patent Application Publication No. 87242/1988 (first prior art). In this application, the inkjet recording stand has an ink tank, and the ink tank There is foam material and many ink jet holes. Foamed polyurethane materials, for example, can thus create a negative pressure by means of capillary forces in the foam, preventing ink from escaping from the ink tank.

Japanese Patent Laid-Open No. 522/1990 (Second Prior Art) discloses an inkjet recording stand in which a first ink tank and a second ink tank are connected together with a porous material, and the second ink tank is The porous material is connected to the inkjet recording head. In this prior art, the porous material is not contained in the ink tank, but is only provided in the ink passage, which improves ink utilization. Since the second ink storage part is provided, the air expands due to the temperature rise (pressure drop) in the first ink tank, and the ink flowing out from it is stored, so that the vacuum degree of the recording head during the recording process is basically maintained. must.

However, in the first prior art, the foam material is required to occupy substantially the entire space in the ink tank, and therefore, the ink capacity is limited. In addition, the amount of ink remaining unused is relatively large, that is, the ink utilization rate is low. Here it is that there is a problem in the prior art. Additionally, it is difficult to gauge the amount of ink remaining, and it is also difficult to maintain a substantially constant vacuum as the ink is consumed. These are additional questions.

In the second prior art, when not recording, the material due to the vacuum is provided on the ink channel. Therefore, there is enough ink in the porous material, but the negative pressure generated by the capillary force of the porous material is not enough. Small holes leak out. This is a problem. If the ink-jet holder is replaceable, its ink-jet recording head is integrated with the ink tank, and the ink tank is mounted on the ink-jet recording head, so the second prior art cannot be used. This is another question.

Japanese Patent No. 67269/1981 and No. 98857/1984 disclose an ink tank employing a spring-loaded oil bladder, which has the advantage of utilizing spring force so that the internal negative pressure generated in the ink supply portion is stabilized. However, this device has problems in that the shape of the spring is limited, the method of providing the required internal negative pressure, and fixing the ink tank to the ink bag is complicated, and therefore, the cost is high. In addition, for thin ink tanks, the ink retention rate is small.

Japanese Patent No. 214666/1990 discloses a compartmentalized ink tank, the inner space of which is divided into many ink chambers, and each chamber is connected by a small hole that can provide negative pressure. In the divided chamber ink tank, the internal negative pressure of the ink supply part is generated by the capillary force of the small orifice connected to the ink chamber. In this device, the structure of the ink tank is simpler than that of the elastic bag device, so it is advantageous in terms of manufacturing cost. Moreover, the shape of the ink tank is not limited by the structure. However, the divided chamber type has a problem that when the position of the ink tank changes, the small hole cannot reach the ink depending on the amount of remaining ink, and as a result, the internal negative pressure becomes unstable and may even reach the level of ink leakage. Therefore, this ink tank is limited in use.

SUMMARY OF THE INVENTION Accordingly, the main object of the present invention is to provide an ink tank that is easy to handle, an ink jet recording head using the ink tank, and an ink jet recording apparatus using the ink tank.

The present invention provides a liquid tank for containing printing liquid to be supplied to a recording head for an inkjet recording device, comprising: a first chamber containing a negative pressure generating material, having an air hole communicated with ambient air and a printing liquid supply port to allow the printing liquid to be supplied to the recording head; a second chamber, which provides a printing liquid storage chamber for the first chamber, communicates with the first chamber through a communication port communicated with the first chamber, and allows the printing liquid to flow in The first chamber, and allows air to be introduced from the first chamber to the second chamber, wherein the second chamber includes a replaceable printing liquid chamber.

The present invention provides a liquid tank for holding printing liquid to be supplied to a recording head for an inkjet recording device, comprising: a first chamber containing a negative pressure generating material, and having an air hole communicating with ambient air and a supply port for supplying printing liquid to the recording head; and a second chamber communicating with the first chamber through a communication port to provide a printing liquid storage chamber for the first chamber, a part of the second chamber being separable from the rest Open to provide a replaceable print fluid chamber.

The present invention provides a component for forming a liquid tank for containing printing liquid to be supplied to a recording head for an inkjet recording apparatus, comprising a first chamber containing a negative pressure generating material, and having an air hole communicating with ambient air and a supply port for supplying printing liquid to the recording head; and an additional chamber which is smaller than the first chamber and communicates with the first chamber through a communication port, the additional chamber being connected to another additional chamber Coupled to form a printing liquid storage chamber for the first cavity, the coupling port of the additional cavity protrudes from the additional cavity, and is configured to move the closing part of the other additional cavity, allowing the printing liquid to flow from the other cavity when the other additional cavity is coupled to the additional cavity. An additional cavity flows to the additional cavity.

The present invention provides a recording head assembly for an inkjet recording apparatus, including a liquid tank, and a recording head connectable to a supply port of a first chamber, so that printing liquid can be supplied to the recording head.

The present invention provides an ink jet recording apparatus comprising a recording head assembly, and means for mounting the recording head assembly to said apparatus for recording on a recording medium.

The above and other objects, features and advantages of this invention will be better understood by understanding the following preferred embodiments of the invention with reference to the accompanying drawings.

FIG. 1 is a connection between a recording head and an ink tank according to an embodiment of the present invention.

Fig. 2 is a recording head and an ink tank according to another embodiment of the present invention.

Fig. 3 is an ink tank according to an embodiment of the present invention.

Fig. 4 is a perspective view of a recording device.

Fig. 5 is an ink tank according to another embodiment of the present invention.

Fig. 6 is an ink tank according to another embodiment of the present invention.

Fig. 7 is an ink tank according to another embodiment of the present invention.

Fig. 8 is an ink tank according to another embodiment of the present invention.

Fig. 9 is an ink tank according to another embodiment of the present invention.

Figure 10 is an ink supply method.

Fig. 11 is a graph showing the change of internal pressure in the ink supply portion of the ink tank according to an embodiment of the present invention.

Fig. 12 shows the ink supply method in the comparative example.

Fig. 13 is a graph showing pressure changes in the ink supply portion in the comparative example.

Figure 14 is the original state when the ink tank is full of ink.

Figure 15 is the state where the gas-liquid interface begins to form.

Figure 16 The state when the ink is about to run out.

Fig. 17 is the state when the ink has been used up.

Figure 18 is a perspective view of a recording head unit having four combined, and a corresponding ink tank used in the unit.

Fig. 19 is an ink tank according to another embodiment of the present invention.

Figure 20 is an ink supply method.

Fig. 21 is a longitudinal sectional view of an ink holder main body for ink jet recording according to still another embodiment of the present invention.

Fig. 22 is a cross-sectional view of the main body of the ink holder on the ink jet recording apparatus in Fig. 21.

Fig. 23 is a sectional view of the main body of the ink holder, particularly showing the surface of the rib in Fig. 21;

Fig. 24 is a sectional view of the main body of the ink holder, showing the surface of a rib in another embodiment of the present invention.

Fig. 25 is an enlarged sectional view of a rib plate in another embodiment of the present invention.

Fig. 26 is a longitudinal sectional view of the ink holder main body of a replaceable inkjet recording device according to still another embodiment of the present invention.

Fig. 27 is a cross-sectional view of the ink holder main body of an interchangeable inkjet recording device according to another embodiment of the present invention.

Fig. 28 is a sectional view of the main body of the ink holder according to still another embodiment of the present invention, showing the surface of its ribs.

Fig. 29 is a longitudinal sectional view of an ink holder main body for an ink jet recording apparatus according to a comparative example.

Fig. 30 is a sectional view of the main body of the ink holder for the inkjet recording apparatus in the comparative example.

Fig. 31 is a sectional view of the main body of the ink holder, showing the surface of a rib in a comparative example.

Fig. 32 is an enlarged cross-sectional view showing a cross-section of a rib in the comparative example.

Figure 33 is the horizontal printing position.

Figure 34 is the cushioning effect of the compressed ink absorbing material in the ink chamber penetrating ink.

Fig. 35 is an example of distribution of compressibility in a compressed ink absorbing material according to still another embodiment of the present invention.

Fig. 36 is another example of the compressibility distribution of the compressed ink absorbing material in the Fig. 35 embodiment.

Fig. 37 is yet another example of the compressibility distribution of the compressed ink absorbing material in the Fig. 35 embodiment.

Fig. 38 is an example of the compressibility distribution of the compressed ink absorbing material in the comparative example.

Fig. 39 is still another example of the compressibility distribution of the compressed ink absorbing material in the comparative example.

Figure 40 is an example of an additional ink chamber according to yet another embodiment of the present invention.

Figure 41 is an example of an additional ink chamber in the Figure 40 embodiment.

Figure 42 is an example of a separate compressed ink absorbing material according to yet another embodiment of the present invention.

Fig. 43 is an example of the arrangement of the ink absorbing material in the ink chamber in still another embodiment of the present invention.

Fig. 44 is a problem when assembling the device in the embodiment of Fig. 43.

Fig. 45 is the consumption of ink in the comparative example.

Fig. 46 is the leakage of ink when the pressure drops in the comparative example of Fig. 45 .

Fig. 47 is a modified example of still another embodiment of the present invention.

Fig. 48 is a modified example of the embodiment of Fig. 47 .

Fig. 49 is a sectional view of an embodiment of the present invention, showing a replaceable ink tank and a recording head mounted on a holder.

Fig. 50 is the consumption of ink in the device of Fig. 49 embodiment.

Figure 51 is the principle of exchange between air and ink.

Figure 52 is a graph showing the internal pressure of the ink supply portion in still another embodiment of the present invention.

Fig. 53 is the buffering effect of ink in the device of Fig. 52 embodiment.

Fig. 54 is an example of a block diagram of a control system for this device.

Fig. 55 is a state when detecting the amount of remaining ink according to another embodiment of the present invention.

Figure 56 is a graph showing the internal pressure of the ink supply portion of the ink tank of the Figure 55 embodiment.

Fig. 57 is an example of a method of replenishing ink.

Fig. 58 is the ink consumption situation of another embodiment of the present invention.

Figure 59 is the further consumption of ink in the embodiment of Figure 58.

Fig. 60 is the situation of detecting the amount of remaining ink in the device of Fig. 58 embodiment.

Figure 61 is the state of re-injecting ink after the ink in the ink cavity is used up.

Fig. 62 is the detection of remaining ink amount in another embodiment of the present invention.

Fig. 63 is the detection of the remaining ink amount improved in the embodiment of Fig. 62 .

Fig. 64 is a method for replenishing ink according to another embodiment of the present invention.

Figure 65 is ink flow when pressure drops.

Fig. 66 is a graph showing the relationship between the amount of remaining ink and the resistance between electrodes.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a sectional view of the connection between a recording head, an ink tank and a holder in an ink jet recording apparatus according to an embodiment of the present invention. In this embodiment, the recording head 20 is of an ink-jet type, which uses an electrothermal transducer to generate thermal energy in response to an electric signal, causing lamellar boiling in the ink. In FIG. 1, the main part of the recording head 20 is connected or pressed into a laminated structure with the recording head base plate 111 by using the positioning reference protrusions 111-1 and 111-2 on the recording head base plate 111. In the direction perpendicular to the plane of FIG. 1, the positioning position is realized by the recording head positioning portion 104 on the holder HC and a protrusion 111-2. Along the vertical direction of the cross section in Fig. 1, a part of the protrusion 111-2 protrudes to cover the positioning part 104 of the recording head, but the protrusion 11-2 is cut off (not shown) part and the recording head positioning part 104 is used for correct positioning. The heating plate 113 is formed by a film-forming process, and includes a sheet heat transfer member (jet heater) mounted on a Si substrate and an electric circuit for supplying power thereto, and the electric circuit can be made of a metal such as aluminum. The circuit is made to be compatible with the recording head flexible base plate (the PCB of the recording head) that accommodates the circuit, and the end of the flexible base plate has a pad that accepts the electrical signal transmitted from the host. These components are all connected by wires. On the integral top plate 112 made of polysulfone or the like, there are wall plates for separating a plurality of ink passages corresponding to the ejection heaters. There is a common fluid chamber for receiving ink from a replaceable ink tank through a channel, and supplying ink to a plurality of ink channels, and a plurality of orifices for ejection ports. The top plate 112 is pressed against the heating plate 113 by an unshown spring, and the heating plate is pressed and spaced apart by a sealing member, thus constituting the ink ejection outlet portion.

In order to communicate with the replaceable ink tank 1, a channel 115 integrated in the top plate 112 in a sealed manner passes through a plurality of holes in the head PCB 113 and the head bottom plate 111 to the opposite side of the head bottom plate 111. In addition, the recording head PCB 113 is connected and fixed to the recording head substrate 111 at the penetrating portion. A filter 25 is provided at the end of the channel 115 connected to the ink tank 1 to prevent foreign matter or air bubbles from entering the ink ejection part.

The replaceable ink tank is connected to the recording head 20 by a constraining guide rail and the pressurizing device 103, while the ink-absorbing material in the ink supply part is in contact with the filter 25 at one end of the channel 115, so that the mechanical connection can be completed. After this connection, the ink is supplied in such a way that the ink is forced into the recording head 20 from the replaceable ink tank 1 by using the recording head suction recovery pump 5015 in the main body of the recording apparatus.

In this embodiment, the recording head 20 and the replaceable ink tank 1 are connected to each other through the action of the pressurizing device. At the same time, the recording head 20 and the support HC can also be connected mechanically and electrically in the same direction, so that , the positioning between the backing plate on the recording head PCB 105 and the driving electrode 102 of the recording head is reliably achieved.

In this embodiment, the sealing ring is a relatively thick elastic material ring, so the ink supply part is sealed with sufficient width at the connecting part with the replaceable ink tank outer wall.

As mentioned above, in the present embodiment, the replaceable ink tank 1 and the recording head are completely combined together, so by pushing the replaceable ink tank, the carriage and the recording head can be formed with a simple structure. Reliable positioning with each other, and at the same time, the recording head and the replaceable ink tank are connected together outside the main body with a simple structure, so that they can be mounted on the carriage. Therefore, the replacement operation is simple and convenient. In this embodiment, the electrical connection between the carriage (the main part of the recording apparatus) and the recording head is realized simultaneously. Therefore, the operability of replacing the recording head and the replaceable ink tank is good. A possible alternative is to use a separate junction box to make the electrical connections, but this would require an increased structural width to allow for positioning of the recording head and connection to the replaceable ink tank. Fig. 4 shows a horizontal recording apparatus. The arrangement and working process of the recording head in the inkjet recording device of this embodiment will be described below with reference to FIG. 4 . In FIG. 4, the recording paper P is fed upward by a flat roller 5000, and pressed against the flat roller 5000 by a platen 5002 over the entire range of the carriage moving direction. A carriage moving pin of the carriage HC is engaged in the helical groove 5004 . The carriage is supported by a lead screw 5005 (drive member) and a light rod 5003 parallel to the lead screw, and it can reciprocate along the surface of the recording paper P on the flat roller 5000. The lead screw 5005 is driven to rotate by the driving roller that can rotate forward and backward through the motion gears 5011 and 5009. The reference numerals 5007 and 5008 refer to photosensitive couplers, which are used to detect whether the carriage rod 5006 is in front of it, so as to switch the motor 5013 Direction of rotation (end position sensor). A signal for recording an image is transmitted to the recording head in a time relationship with the movement of the carriage carrying the recording head, and the ink dots are ejected to an appropriate position to complete the recording work. Reference numeral 5016 designates a part for supporting on the cap part 5002, and the cap part is used to cap the front surface of the recording head. Reference numeral 5015 refers to a suction device for sucking the inside of the cover. As such it relies on suction through the orifice 5023 in the cover to effect refresh or recovery of the recording head. The cleaning bracket 5017 is supported by a support member 5019 that reciprocates the bracket, and these two parts are all supported on the support plate 5018 of the main machine. The suction device, brackets or similar parts can also be of other known types. The lever 5012 used to time the suction and recovery actions moves together with the cam 5020 in contact with the carriage. The driving force transmitted from the driving motor is controlled by a known transmission such as a clutch. When the carriage enters the end position or the area close to the end position, the recovery device will realize the predetermined operation process in the predetermined time determined by the leading screw 5005 at the corresponding position.

As shown in Fig. 33, the ink jet recording apparatus of this embodiment operates in a vertical printing position. In the vertical position, the recording scanning process is performed with the recording material P facing the bottom surface of the recording head 2010 . At this time, feeding, printing and unloading of paper can be carried out substantially on the same plane, so that printing can be found on thick and rigid recording materials such as postcards and OHP paper. The casing of the replaceable inkjet recording device of this embodiment is provided with four rubber pads on the bottom surface in FIG. In this way, the print-finding device can be stably placed on the corresponding search position. In the vertical printing position, the replaceable ink tank 2001 is above the ink ejection portion of the recording head 2010 facing the recording material P, so it is necessary to support the hydrostatic head generated by the ink while keeping it small. It is best to maintain a small internal negative pressure of the ink in the ink ejection part, so that the meniscus of the ink in the ink ejection part can be kept stable.

The recording apparatus shown in FIGS. 4 and 33 can be used in various embodiments of the present invention which will be described below.

For the ink tank of the present invention, a detailed description will be made, firstly, the structure and working process of the ink tank will be described.

(structure)

As shown in Figure 2, an opening 2 for communicating with the inkjet head is arranged on the main body of the ink tank, a material 3 for placing a vacuum, a material chamber (or tank) 4 for generating a vacuum, and a An ink holding cavity or tank 6 for containing ink is adjacent to the vacuum-generating material tank, separated by ribs 5, and communicates with the vacuum-generating material tank 4 at the bottom 11 of the ink tank.

working process(1)

Fig. 2 is a schematic sectional view of an ink tank, wherein the connector 7 for supplying ink to the inkjet recording head is inserted in the ink tank and protrudes into the material for generating a vacuum, so that the inkjet recording device is in operation Down. A filter may be provided at the end of the connector to remove debris from the ink tank.

When the ink jet recording apparatus is in operation, ink is ejected through one or several small holes of the ink jet recording head, so that ink suction is generated in the ink tank. The ink 9 is sucked into the connecting piece 7 from the ink tank 6 through the gap 8 between the end of the rib plate and the bottom plate 11 of the oil quantity bracket, and in the material tank 4 that generates a vacuum through the material 3 that generates the vacuum, Then, the ink is supplied to the ink jet recording head. Thereafter, the internal pressure of the sealed ink tank 6 drops except for the space 8, and as a result, there is a pressure difference between the ink tank 6 and the vacuum-generating material tank 4. As the recording process continues, the pressure differential increases. Since the vacuum-generating material tank 4 communicates with the atmosphere through a vent hole, air enters the ink tank 6 through the gap 8 between the vacuum-generating material and the end portion 5 of the rib and the bottom plate 11 of the ink holder. At this point, the pressure difference between the ink tank 6 and the vacuum-generating material tank 4 disappears. Throughout the inkjet recording process, the above process is repeated, so that a substantially constant vacuum is maintained in the ink holder. The ink in the ink tank can be utilized substantially in its entirety, except for the ink sticking to the inner wall surface of the ink tank, so that the utilization rate of the ink is improved.

working process(2)

The main working process of the ink tank is described in further detail according to the model shown in Fig.10.

In FIG. 10, the ink tank 106 is corresponding to the ink tank 6 in FIG. 2, and ink is housed inside. Reference numerals 102, 103-1 and 103-2 refer to capillaries corresponding to the vacuum generating material 3. A vacuum is created in the ink tank by means of the surface tension of the capillary. The element 107 corresponds to the connection member 7, which is connected to an ink jet recording head not shown in the figure, and ink is supplied from an ink tank. The ink is ejected through the small hole and flows in the direction indicated by the arrow Q.

The state shown in this figure is a state in which a small amount of ink has been output from the vacuum-generating material. Therefore, a small amount of oil is also extracted from the ink tank, from the ink-filled state of the ink tank and the vacuum-generating material. status. A pressure balance is established between the hydrostatic head at the orifice of the recording head, the falling pressure in the ink tank 106, and the surface tension in the capillaries 102, 103-1 and 103-2. When the ink is output from this state, the ink levels in the capillaries 103 - 1 and 103 - 2 hardly change, and the ink is output from the ink tank 106 through the space 108 corresponding to the space 8 . Thus, the degree of vacuum in the ink tank 106 can be increased. Then, the meniscus of the capillary 102 changes, generating one or more air bubbles. Air bubbles enter the ink tank 106 due to the breakdown of the meniscus. The amount of ink consumed is replenished from the ink tank 106 in this way without significant changes in the liquid level in the capillary tubes 103-1 and 103-2, i.e. without causing the ink to remain in the vacuum-generating material. There is a noticeable change in the distribution, i.e. maintaining a balanced internal pressure.

When a total amount of ink Q is supplied, this change in volume appears as a change in the height of the meniscus in the capillary 102, and this change in the surface energy of the meniscus increases the negative pressure in the ink supply portion. However, the destruction of the meniscus allows air to enter the ink tank. As a result, the air replaces the ink, and the meniscus returns to its original position. Thus, the internal pressure of the ink supply portion is maintained at a predetermined internal pressure by the capillary force of the capillary tube 102 .

Fig. 11 shows the internal pressure in the ink supply portion of the ink tank of this embodiment of the present invention, as a function of the total amount of ink supplied (consumption). As mentioned above, in the start state (FIG. 14), the ink supply is started from the vacuum-generating material tank. More specifically, until the meniscus is formed at the void 8 at the bottom of the ink tank, the ink contained in the tank of material that generates the vacuum is supplied. Therefore, as with the ink tank filled with ink-absorbing material according to the prior art, the internal pressure in the ink supply part is caused by the ink on the top surface (air-liquid interface) of the compressed chewing material in the material tank that creates a vacuum. Produced by the balance between the surface tension and the static head of the ink itself. When, as mentioned above, due to the ink in the vacuum-generating material tank is reduced to such a state with the consumption (ink supply) of the ink, that is, when an air-liquid interface is formed at the bottom of the ink tank (Fig. 15, X of Fig. 11 dot) to start supplying ink from the ink tank. The internal pressure of the ink supply is maintained by the capillary force of the compressed ink-absorbing material adjacent the bottom of the ink chamber. As long as ink is supplied from the ink tank, the internal pressure remains substantially constant. When the ink is further consumed and the ink level in the ink tank drops below the bottom of the ink chamber wall, the ink in the ink tank is basically consumed (point Y in Figure 16 and Figure 11). Since the ink tank communicates with the outside atmosphere, air can immediately enter the ink tank. Then, the small amount of ink remaining in the ink tank is absorbed by the compressed ink-absorbing material contained in the vacuum-generating material tank, so that the amount of ink contained in the vacuum-generating material tank increases. This causes the internal pressure of the ink supply portion to change in the positive direction by the amount the ink top surface (air-liquid interface) rises slightly. As the ink is further consumed, the ink in the vacuum-generating tank is consumed. However, if the air-liquid interface is lowered below the ink supply portion, the recording head starts to suck air, and the ink supply device reaches its limit (Fig. 17). When this state is reached, the ink tank needs to be replaced. After investigation and research, the inventor found that the suction device of the main unit of the recording device is used to carry out the suction recovery operation at the connection with the recording head, to remove the air bubbles generated in the ink channel during the communication process, and to make a small amount of ink flow out of the ink. tank, a stable ink internal pressure can be maintained from the very beginning. In addition, even if the ink is supplied from the vacuum-generating material tank in the initial stage and the stage just before the ink tank is replaced, as long as it is within the period of stable ink supply shown in FIG. The recording performance is adversely affected, so the recording work can be carried out smoothly. In order to establish the ink supply method according to the above mechanism, the following points should be paid attention to:

It is necessary to form a stable meniscus between the ink and the atmosphere at the position closest to the gap 8 . Otherwise, in order for the meniscus to move into the ink tank, the ink would have to be consumed to such an extent that a high degree of vacuum would be created in the ink supply section. In that case, it is difficult for the recording device to operate at a high frequency, which is disadvantageous from the viewpoint of increasing the recording operation speed.

Fig. 11 shows the variation of the internal pressure in the ink supply portion of the ink tank according to the ink supply amount (consumption amount). In the figure, the so-called static pressure P111 in the state of not supplying ink and the so-called dynamic pressure P112 in the state of ink supply are shown.

The pressure difference between the dynamic pressure P112 and the static pressure P111 is the pressure loss δp during ink supply. The negative pressure generated during the movement of the meniscus is influential.

Therefore, it is necessary to cause the meniscus to break at this location without delay. For this purpose, air introduction channels are provided for forced introduction of air close to the recess 8 . Several embodiments in this regard are described below.

Example 1

Fig. 3 shows the first embodiment. The material 3 that creates the vacuum in the ink tank is an ink-absorbing material such as polyurethane foam or the like. When the absorbent material is placed in the vacuum-generating material tank 4, a gap A32 is left in a part of the vacuum-generating material tank to function as a passage for introducing air. This gap extends to the vicinity of the gap 8 between the bottom of the ink tank 11 and the end 8 of the rib 5 . In this way, it communicates with the atmosphere through the vent. When the ink supply from the ink supply portion is started, the ink in the absorbent material 3 is first consumed, so that the internal pressure of the ink supply portion reaches a predetermined value. Then, an ink surface A31 shown in FIG. 3 is stably formed in the absorbent material 3, while a meniscus between the ink and the atmosphere is formed adjacent to the void 8. FIG. The height of the gap 8 is preferably not greater than 1.5 mm, and it is as long as possible in its length direction. After such a state is established, the meniscus at the gap 8 is destroyed by continuous ink consumption without delay. Thus, ink can be supplied stably without increasing the pressure loss ?p. Therefore, stable ink ejection can be obtained at high-speed printing.

When recording is not performed, the surface tension of the vacuum-generating material itself (or the surface tension at the interface between the ink and the vacuum-generating material) remains constant, so ink can be prevented from leaking from the inkjet recording head.

In order to utilize the ink tank of the present invention in a color ink jet recording apparatus, separate ink tanks may be filled with inks of different colors, (eg, yellow, black, magenta and cyan). Individual ink holders can be combined into one ink tank. Another way is to provide a replaceable ink holder for the most commonly used black ink, and a replaceable ink holder for combining several color ink tanks. Other combinations can also be used according to the requirements of the ink device used.

The present invention is described in more detail below.

When adopting the ink tank of the present invention, in order to control the degree of vacuum in the inkjet recording head, the following various parameters are preferred: the material, shape and size of the village material 3 that generates the vacuum; the shape and size of the rib end 8; The shape and size of the space 8 between the rib end 8 and the ink tank bottom 11; the volume ratio between the material tank 4 and the ink tank 6 for creating a vacuum; the shape and size of the connection piece 7, and its insertion into the ink tank the depth of the filter; the shape, size and number of filters; and the surface tension of the ink.

The material of the vacuum-generating element may be any known material as long as it can bear the weight of the liquid (ink) stored therein and a small vibration. Examples are sponge-like materials made of fibers and porous materials with continuous microscopic pores. A porous plastic made of polyurethane foam is preferred because of its ease of regulating the vacuum and its ability to hold ink. Specifically, with this foam, the density of its cells can be adjusted during the manufacturing process. When the foam is thermocompressed to adjust its cell density, the heat causes it to decompose, changing the properties of the ink, and possibly causing adverse effects on recording quality, requiring cleaning. In order to meet the requirements of various ink holders for various ink jet recording devices, a foam material having a corresponding cell density is required. It is best not to use thermal compression to process foam materials, but to cut a foam material with a predetermined mesh number (the number of pores per inch) to the required size, and then put it into a material tank that generates a vacuum to reduce the pressure on the foam. This provides the desired pore density and capillary force.

Changes in environmental conditions in the inkjet recording apparatus.

In ink holders with closed ink tanks, ink may leak. This is because, when the environmental conditions of the ink tank contained in the inkjet recording device change (temperature increases or pressure increases), the air in the ink tank expands (and the ink also expands), and the ink contained in the ink tank Squeeze outward, and as a result, the ink leaks out. In the ink holder of the present embodiment, the volume of air expansion in the closed ink tank (including the volume of ink expansion, although this amount is very small) is considered according to the worst environmental conditions predicted, and the corresponding amount of The ink is dispensed from the ink tank to the village tank where the vacuum is created. The location of the vent is not limited, except that it is higher than the opening for connection to the vacuum-generating material canister. In order that the ink can also flow to the vacuum-generating material at a position far away from the connection opening when the environmental conditions change, the vent opening is preferably opened at a position far from the connection opening. Parameters such as the number, shape, and size of the air vents can be determined by those of ordinary skill in the art according to the situation of ink evaporation.

Shipping of the ink holder itself.

During the transport of the ink holder itself, the connection openings and/or vents are preferably sealed with seals or sealing compounds to prevent evaporation of the ink or expansion of ink and air within the ink holder. The seal is preferably a single-layer partition used in the packaging industry, a multi-layer seal made of a single-layer partition and a plastic film or a composite partition material, and the composite partition material has a single-layer partition, a plastic film and aluminum foil or reinforcing materials such as paper and cloth. It is preferable to add an adhesive layer of the same or similar material to that of the main body of the ink holder, and bond it with heat to improve the airtight sealing performance.

In order to prevent air ingress and ink evaporation, it is effective to pack the ink holder. The air is then sucked out of the inside and it is sealed again. As for the packaging material, it is preferable to select from the above-mentioned separator materials in consideration of air permeability and liquid permeability.

By making the correct selection as mentioned above, it is possible to highly reliably prevent the ink from leaking during the transportation of the ink holder.

Manufacturing method.

The material of the main body of the ink holder can be any known material. However, it is desirable that this material does not affect ink ejection from the recording head, or has been treated to avoid such effects. At the same time, it is also desirable to consider the productivity of the ink holder. For example, the main body of the ink holder is divided into the bottom 11 and the upper part, and are integrally formed with resin material, respectively, and after being placed in a vacuum-generating material, the bottom 11 and the upper part are bonded together, so that the ink holder is made. If the resin material is transparent, or translucent, the ink in the ink tank can be observed from the outside, and therefore, it is easy to judge when to replace the ink holder. In order to facilitate the bonding of the above-mentioned sealing materials and the like, it is advisable to provide a protrusion as shown in the figure. From an appearance point of view, the outer surface of the ink holder may be grainy.

Ink can be injected by pressurized or depressurized method. Preferably, ink filling ports are provided on the ink tanks so that other openings are not polluted during the ink filling operation. After filling the ink, it is best to cover the ink filling port with a plastic or metal plug.

The structure and shape of the ink holder can be varied within the scope of the inventive point of the present invention.

other.

The ink tank (ink holder) in the above embodiment can be replaceable, and can also be integrated with the recording head.

When the ink tank is replaceable, it is preferable that the main unit can detect the replacement of the ink tank, and the recovery process (for example, the suction process) is performed by the operator.

As shown in Figure 4, this ink tank can be used in an inkjet printing machine, in which 4 recording heads are connected into a recording head that can be connected with 4 color ink tanks Bkla, Clb, Mlc, Yld 20.

Comparative example 1

Next, a comparative example will be described in which the internal pressure of the ink supply portion of the ink tank varies with the ink supply surface.

There is no channel for introducing air on the ink tank, and the vacuum-generating material tank contains an absorbent material with micropores and substantially evenly distributed sizes.

As shown in FIG. 14, at the initial stage, the ink tank 6 is substantially filled with ink, and a certain amount of ink is also contained in the vacuum-generating material tank. When starting to supply ink from this state, the ink is output from the material tank 4 that generates the vacuum, so the ink top surface (air) of the absorbing material 3 in the material tank 4 that passes through the static pressure of the ink and the material tank 4 that generates the vacuum is output. - The balance between capillary forces at the liquid interface) creates internal pressure in the ink supply section. As the ink is continuously output, the top surface of the ink descends. Therefore, the negative pressure obviously increases linearly with the height of the ink, and reaches the state represented by symbol a in FIG. 13 . The negative pressure of the ink supply part continues to increase until the ink supply surface forms a gas-liquid interface (meniscus) at the gap at the bottom of the ink chamber.

The ink surface in the absorbing material is greatly lowered until a state of a meniscus is formed at the void, and, depending on the circumstances, the ink surface may be lowered beyond the connection portion with the recording head.

If so, air enters into the recording head, causing unstable or non-ejection of ink.

Even if it does not reach this level, the internal pressure in the ink supply portion may increase beyond a predetermined negative pressure determined by the pore size of the absorbing material in the void, as shown at b in FIG. 13 . The reason for this is as follows: the absorbent material is more or less compressed by the inner wall of the material tank that creates the vacuum around it, but there is no wall in the gap, the absorbent material is not compressed, and as a result, the compression rate here is slightly smaller than other parts point. Therefore, this situation is shown in FIG. 12 .

This situation is shown in the figure. At this time, part of the ink in the vacuum-generating material tank 4 has been consumed. If the ink consumption continues under this condition, the meniscus R4 corresponding to the largest pore size among R2, R3 and R4 in the absorbing material 3 moves a distance greater than that of the menisci in R3 and R4. As the meniscus approaches the void, the surface tension suddenly decreases, causing the meniscus to enter the ink tank, and the meniscus ruptures, allowing air to enter the ink tank. At this time, only a small amount of ink is supplied from the two parts of R ₃ and R ₄ , rather than output from the part of R ₂ . When the meniscus moves, the pressure loss δP is quite large.

However, when the meniscus that was once broken is restored, it is re-formed at a place close to the original position by inertia, so the state of high pressure loss continues for a period of time.

Until the meniscus stabilizes at the part with the micropore size _R1 , the same action process is repeated. Once the meniscus stabilizes in the void, air bubbles enter the ink tank until a negative pressure determined by the pore size _R1 in the void is established to reach a steady state.

The above process is shown in Figure 13.b. In this section, the ink can be output from both the ink tank and the absorbent material. If the air introduction channel is not specially provided, the internal pressure of the ink supply part will be unstable, and the pressure loss δp of the ink supply will increase. Therefore, the ink ejection performance is poor, and as a result, high-speed printing is difficult.

Example 2

Figure 5 shows another embodiment of the device.

In this embodiment, two ribs 61 are provided on the partition rib 5 of the vacuum-generating material tank 4 . An air introduction passage A51 is formed between these two ribs and the absorbent material 3 . The position of the bottom end A of the rib 61 is higher than the bottom end B of the rib plate 5, so that, as long as a rectangular parallelepiped absorbent material 3 is simply put into the vacuum-generating material tank 4, the gap 8 is covered by the absorbent material 3 . Therefore, the air introduction channel A51 can easily and stably extend to a position very close to the gap 8 . Arrow A52 indicates the air flow direction.

With this ink tank, the printing process can be effectively performed, and it has been confirmed that the ink surface and meniscus shown in Fig. 5 can be quickly formed due to the ink supply surface caused by the recording work, and the gap between the air and the ink Rapid replacement can also be achieved by the rupture of the meniscus. Therefore, the ink can be supplied with only a small pressure loss to the head, and thus a high-speed printing process can be realized stably.

Example 3

Fig. 6 shows a device of a third embodiment in which the number of ribs 71 is increased to increase the number of air introduction passages. Ribs 71 are provided to separate the vacuum-generating material tanks. According to this embodiment, a plurality of air introduction passages can provide stable airflow from the vent 13 to the vicinity of the gap 8, so, like the first and second embodiments, ink supply can be realized with a small pressure loss, And can stably realize high-speed printing process.

In this embodiment, even if the passage port 13 is arranged far from the gap 8, air can be smoothly introduced.

Example 4

Fig. 7 shows the apparatus of the fourth embodiment of the present invention.

In this embodiment, similarly to the second and third embodiments, ribs 81 are provided on the partition ribs to form air introduction passages A71. The ribs 81 are asymmetrical with respect to the ribs 5, so that the ink flows from the ink tank 6 through the gap 8 into the passage in the material tank 4 that creates a vacuum, corresponding to this ink flow A72, passing along the air introduction passage A71. The passage of the air flow A73 of the space 8 into the ink tank 6 can be formed independently of each other with respect to the center line A, so that the pressure loss due to exchange can be reduced.

More specifically, this structure is effective in reducing the pressure loss ?p required for the exchange between ink and air by about half.

Thus, ink can be stably ejected from the recording head.

Example 5

FIG. 8 is another embodiment of the device provided with ribs 91 . In Embodiments 2 to 4, the top end of the rib 91 extends to the upper portion of the inner surface of the wall of the tank 4 containing the vacuum-generating material, but in the present embodiment, the rib 91 does not extend to such an extent. Thus, the top of the absorbent is not compressed by the ribs 91, and surface tension can be generated in this compressed portion, thereby further stabilizing the vacuum control.

More specifically, ink is supplied by the absorbent material 3 until the ink surface A81 in the absorbent material 3 (the material 3 that generates the vacuum) moves to the stable ink surface A82 in the ink tank in the initial state that starts to supply the ink. . This is because, if the air 82 for gas-liquid exchange through the air-introduction channel is pushed too fast, the consumption of the ink in the absorbent material 3 becomes slow, with the result that the ink is supplied from the ink tank. The amount of ink that can flow from the ink tank 6 into the vacuum-generating material tank 4 is thus limited when environmental conditions change, such as pressure changes. The cushioning effect of the absorbent material 3 against ink leakage is then deteriorated. In the present embodiment, since the air introduction channel A83 is set in the above-mentioned manner, the air is introduced only after the ink in the absorbent material 3 is consumed to a certain extent, and the ink surface of the absorbent material 3 is controlled in this way, Thereby, the effect of resisting ink leakage is improved.

Example 6

Fig. 9 shows another embodiment.

In this embodiment, the air introduction channel is formed by slotting 100 on the isolation ribs or walls.

According to this embodiment, the inaction of the compressibility of the absorbing material contained in the vacuum-generating material tank is reduced, and therefore, it is easy to control the degree of vacuum, so that ink can be supplied stably.

Example 7

Fig. 20 shows yet another embodiment.

Its structure is similar to the embodiment in FIG. 6 , but the air introduction channel extends to the bottom end of the rib, which is different from FIG. 6 .

Similar to Embodiments 5 and 6, the absorbent material 3 in the ink tank is consumed until the ink surface at the initial stage of ink consumption moves to a stable ink surface position on one end C of the air introduction passage A201 ink in. Therefore, what is consumed is the ink in the ink tank 6, and the gas-liquid exchange is realized through the air introduction passage. This structure corresponds to the type shown in FIG. 21 because the air introduction passage extends to the bottom end of the rib. A detailed description will be given when describing the version in FIG. 21 .

The absorbent material 3 can be regarded as the hairline shown in FIG. 20 . The air introduction passage A201 leads from the C portion to the bottom end of the rib, and it can be considered that the air introduction passage A201 communicates with the capillary again at the upper part of the C portion.

As mentioned above, at the initial stage of ink supply, the ink surface in the absorbent material 3 is at a certain height. However, this surface gradually decreases as the ink is consumed. The internal pressure (negative pressure) in the ink supply portion gradually increases.

When the ink is consumed to the height C at the top of the air introduction channel A201, a meniscus is formed at the position D of the capillary. When the ink is further replenished and consumed, the meniscus of the ink, that is, the surface of the ink, drops again. If it falls to the position of E, the surface tension of the ink surface in the air introduction channel suddenly decreases, so the ink in the air introduction channel can be directly consumed. Thereafter, ink is consumed from the ink tank to maintain this position. That is to say, gas-liquid exchange emerges. During the consumption of the ink, the ink surface is stabilized in this way at a position slightly lower than the height C, so that the internal pressure of the ink supply portion is stabilized. When the ink supply is stopped, the meniscus in the capillary returns from position E to position D, thereby remaining stable.

As before, the ink surface in the absorbent stock is moved back and forth between positions D and E until the ink tank is completely used up. In the figure, A202 indicates the ink supply period, and A203 indicates the non-ink supply period.

Thereafter, ink is supplied from the ink-absorbing material. Therefore, the internal pressure (vacuum) of the ink supply portion increases, and it becomes no ink supply.

The internal pressure of the ink supply part causes a pressure difference between the capillary force of the absorbing material 3 (the height to which the absorbing material can suck the ink) and the height of the ink surface in the absorbing material 3, and therefore, the height is set relative to On the predetermined height of ink supply part 6. From this point of view, it is desirable that the pore size of the absorbent material 3 be relatively small.

The reason why the height C is set at a predetermined height with respect to the ink supply portion 6 is that if the ink surface is lower than the ink supply portion 6, air will enter to cause abnormal ink ejection.

However, it is not desirable to be higher than the predetermined height, because the cushioning effect will be reduced when the internal pressure in the ink tank changes due to environmental conditions, so that too much ink flows from the ink tank into the absorbent material. Considering the above, the volume of the absorbing material above the height C should be roughly selected as half the volume of the ink tank.

The mechanism mentioned above will be explained in detail below.

Absorbent materials are generally considered to have a uniform density. The internal pressure (vacuum or negative pressure) in the ink supply part is determined by the height difference H ₁ -H ₂ , where H ₁ is the height to which the capillary force of the absorbent material can suck the ink from the ink supply part, and H ₂ is The height to which ink has been pumped up from the height of the ink supply section.

For example, the suction force of the absorbent material is 60 mm (H ₁ ), and the height of the air introduction channel A from the ink-containing part is 15 mm (H ₂ ), so the internal pressure of the ink supply part is 45 mm water column height = 60 mm-15 mm = H ₁ -H ₂ .

In the initial stage, as the ink is consumed from the absorbent material, the height of the liquid level decreases accordingly, and the internal pressure decreases greatly in a linear manner.

When the ink tank of the above structure is employed, ink can be stably supplied by means of vacuum.

The structure itself of this ink tank is so simple that it can be easily manufactured with a mold or the like, so a large number of ink tanks can be manufactured stably.

When the ink is consumed to such an extent that the height of the ink surface in the absorbent material is in the air introduction path A201, that is, at the position C, in other words, when the ink surface is at the E position, the bend in the air introduction path A201 The liquid level cannot be maintained, so the ink is absorbed into the absorbent material, and the air introduction channel is formed. Then, gas-liquid exchange occurs immediately. On the other hand, the liquid level in the absorbing material rises because the ink is absorbed from the ink tank, whereby the liquid level D is formed, and the gas-liquid exchange stops. In this state, the ink is provided in the air introduction path A201, and the absorbing material above the air introduction path in the model simply functions as a valve.

If in this state, ink is continued to be consumed, the liquid level in the absorbing material is only a little lower, which is equivalent to opening the valve, so that the gas-liquid exchange occurs immediately, so that the ink is consumed from the ink tank 6. When the ink consumption is completed, the liquid level in the absorbent material rises due to the capillary force of the absorbent material. When it rises to the D position, the gas-liquid exchange stops, so the liquid level stabilizes at this position.

Therefore, the liquid level of the ink can be controlled stably by the height of the air introduction channel A201 in this way, that is (the height of the part), and the capillary force of the absorbing material, that is, the suction height of the ink is adjusted in advance , In this way, the internal pressure of the ink supply part can be easily controlled.

In order not to cause the ink to flow too much from the ink tank 6 into the absorbent material 4 when the internal pressure of the ink changes due to changes in environmental conditions, the capillary force of the absorbent material, that is, the suction height of the ink increases, thereby preventing the ink from Spills from the ink tank and also prevents positive pressure in the ink supply.

Example 8

Fig. 21 is a longitudinal sectional view of an ink holder for an ink jet recording apparatus according to an eighth embodiment of the present invention. Fig. 22 is a cross-sectional view thereof, and Fig. 23 is a sectional view showing one surface of the rib.

On the rib 1005 serving as a partition wall between the ink tank 1006 and the vacuum-generating material tank 1004, an air introduction groove 1031 and a vacuum-generating material regulating chamber 1032 are formed. The air introduction groove 1031 is formed in the vacuum-generating material groove 1004, and extends from the center portion of the rib 1005 to one end of the rib 1005, ie, to the gap 1008 formed in common with the bottom 1011 of the ink holder. In the vicinity where the vacuum generating material 1003 is in contact with the air introduction passage 1031 on the rib plate 1005, a vacuum generating material regulating chamber 1032 is formed, which is in the form of a recess.

Since the vacuum-generating material 1003 is in contact with the inner surface of the vacuum-generating material tank 1004, therefore, that is, the material 1003 for generating the vacuum is unevenly pressed into the material tank 1004, and a part of the raw material 1003 for generating the vacuum Contact pressure (compression) is relieved. As shown in Figures 21 and 22. Therefore, when the recording head starts to consume ink, the ink stored in the vacuum-generating material 1003 is consumed first, and is consumed to the adjustment chamber 1032 . If the ink continues to be consumed, the air can easily break through the meniscus of the part where the contact pressure of the vacuum-generating material 1003 has been reduced due to the presence of the regulating chamber 1032, and quickly enter the air introduction channel 1031, thereby making more Easy to control vacuum.

In this embodiment, it is necessary to use an elastic porous material as the vacuum generating material 1003 .

When the recording operation is not performed, the capillary force of the vacuum generating material 1003 itself (surface tension on the interface between the ink and the vacuum generating material) can be used to prevent the ink from leaking out of the inkjet recording head.

29-31 show, as a comparative example, an example of an ink holder without a conditioning chamber for generating a vacuum material.

Even though the comparative example is a holder for ink, in a general state, a normal working process can be realized without any problem by the mechanism described below. Stable operation can be achieved because of the air introduction channel.

However, in order to further stabilize the working process, or to be able to use a porous resin material having continuous micropores as a negative pressure generating material, further control of the working stability is required.

As shown in the enlarged sectional view of FIG. 32 , the vacuum (or negative pressure) generating material 1003 is in contact with the rib 1005 , and part of it enters the air introduction groove 1031 . If so, the contact pressure (compressive force) against the material 1003 at the contact portion A does not decrease. This makes it difficult for air to break through the ink meniscus and enter the air introduction passage 1031 . If so, even if the ink continues to be consumed, gas-liquid exchange does not occur, and the air introduction passage does not function. There is a disadvantage of not being able to supply ink from an ink-absorbing material.

Compared with Comparative Example 2 described above, this embodiment is preferable in this matter.

Example 9

Fig. 24 is a longitudinal sectional view of two ribs 1005 having different cross-sectional portions. Figure 25 is an enlarged cross-sectional view of a rib.

As shown in the figure, the shape of the vacuum generator adjustment chamber 1032 and the air inlet groove 1031 are different from Embodiment 8:

In particular, the stepped position of the rib 105 in contact with the vacuum generator 1003 is circumscribed, further suggesting the effects of pressure contact and compression variation.

Near the rib 1005 , adjacent to the container 1004 , there is a curved surface R through which air is introduced into the ink through the substance 1003 , and the incoming air enters the ink tank 1006 . The ink that enters the ink tank with the air is fed into the substance chamber 1006 . In the context of the air-liquid exchange, air is introduced into the ink in the substance 1003 .

In order to make the air-liquid exchange more smoothly, it is preferable that the pressure contact between the substance 1003 and the substance holding chamber is located in the lower part of the air-liquid exchange range rather than the upper part.

This is because the flow of air from the gaseous ink phase is smoother, and this smoothness is achieved by air passing through the bladder tube of the vacuum pressure object 1003, and the contact force of the tube is released.

For example, the desired effect can be obtained in the form of a vacuum adjustment chamber created by a portion in the middle of the rib 1005 located at the end of the air introduction member.

In order to make the vacuum-generating substance adjustment chamber 1032 of this embodiment achieve the same function, the shape of the vacuum-generating substance can be changed, and the shape and size can be changed in many ways when the above requirements are met.

According to the foregoing, according to this embodiment, the air and the ink in the ink tank are smoothly and stably exchanged with the ink feeding process. As a result, the internal pressure of the ink supply part can be stably controlled, which enables the recording head to Perform high-speed, stable, ink jetting.

In addition, the ink tank does not drip, even if the pressure inside it changes due to changes in external conditions.

Example 10

The ink tank 2001 in this embodiment is a combined form, and its inside is divided into two cavities a and b, and the two cavities are connected at the bottom, and its characteristic is that the ink absorbing material 2002 with adjusted bladder tube force has no gap is placed in a so that an air channel 2003 is provided.

In the situation shown in FIG. 15 , the available ink has already been fed in from chamber 4 and is half consumed with the ink in chamber 6 already filled from both 4 and 6 . In Fig. 15, the ink in the compressed ink absorbing material 3 is maintained at a certain height, and the ink ejection portion on the recording head is stationary, the vacuum in the chamber 6 and the bladder force of the compressed ink absorbing material are at the same height. When the ink is replenished from the ink supply part, the amount of ink in the chamber 4 does not decrease, and the ink in the chamber b is consumed, that is, the amount of ink supplied from the ink chamber 6 to the ink chamber 4 is in accordance with the amount from the ink chamber 4 The amount provided is corresponding, and this corresponding supplement is realized by maintaining internal pressure balance. Corresponding to the above, air is introduced through the ink chamber 4 and the air passage.

At this time, as shown in Figure 15, the air and ink are exchanged at the bottom of the ink chamber, and as the air enters the chamber 6, the meniscus formed by the ink absorbing material in the chamber 4 is blocked by the part near the chamber 6, and the chamber 6 The pressure in is in balance with the aforementioned meniscus maintenance force created by the compressed ink absorbing material. Referring to Figure 2, ink replenishment and internal pressure generation in this type of combination will be described in more detail. When the ink in the chamber 4 is consumed to a predetermined level, the portion of the compression ring ink absorbing material near the wall of the chamber will communicate with the air passage, thereby creating a meniscus against atmospheric pressure. The ink internal pressure in the ink supply portion is maintained by the compressed ink absorber material adjacent the ink chamber wall, the pressure being adjusted to balance with the predetermined balloon force caused by the proper compression. Before the ink flows out, the closed space at the top of the cavity 6 is in balance with the bladder tube force of the compressed ink-absorbing material adjacent to the cavity wall, and the meniscus formed by the ink static head and the compressed ink-absorbing material remaining in the ink cavity b depends on the reduced pressure maintain. When the ink is supplied to the recording head through the ink supply part in this case, the ink flows out of the ink chamber 6, and the pressure in the chamber 6 is further reduced according to the consumption of the ink. At this time, the ink absorbing material at the bottom of the ink chamber wall forms The meniscus is partially destroyed, and air can enter the ink chamber from the damaged place. As a result, the pressure in chamber 6 is excessively reduced by the meniscus maintenance force of the compressed ink absorption village material and chamber b. The ink itself is balanced by the static head. In this manner, the internal pressure of the ink supply portion is maintained at a predetermined level by the bladder force of the compressed ink absorbing material near the bottom of the ink chamber wall.

Figure 34 shows the function of the compressed oil absorbing material as a cushion. The state shown in the figure is that, in the situation shown in FIG. In this embodiment, the ink flowing into the chamber 2004 is retained in the compressed absorbent material 2003, and the correlation between the ink absorption amount of the compressed ink absorbent material and the ink chamber is determined so as not to cause ink dripping when the environment or temperature changes prevail. The maximum ink absorption in the ink chamber 2004 is set with reference to the worst possible ink flow out of the chamber 2006, and the amount of ink remaining in the 2004 chamber when ink flows from 2006 into 2004. The ink chamber 2004 should have as little room as possible to accommodate the ink that the compressed absorbent material can absorb. The coordinates are shown in FIG. 65, in which a solid line represents the relationship between the initial accommodation space of the cavity 2006 before the pressure drops and the amount of ink flowing out when the pressure drops to 0.7 atmospheres. In this figure, the dashed line indicates the case where the maximum pressure drop is 0.5 atmospheres. Regarding the estimated worst case ink flow out of cavity 2006, the maximum amount of ink flowed from cavity 2006 is when the pressure is reduced to a maximum of 0.7 atmospheres, and there is still 30% of the ink contained in the cavity 2006 at this time. If the ink below the bottom end of the chamber wall is also absorbed by the compressed absorbent in chamber 2004, all the ink remaining in 2006 (30% capacity) can be considered to have dripped out. When the worst case is 0.5 atmospheres, 50% of the volume of chamber 2006 flows out. If the amount of ink left is smaller, the greater the expansion of the air in chamber 2006 caused by the pressure drop. This allows more ink to be pushed out. However the maximum amount of ink flowing out of chamber 2006 is less than the ink volume in chamber 2006, and therefore less than the air expansion volume when no more than 30% of the ink remains in the chamber at an assumed pressure of 0.7 atmospheres. The result is that the amount of ink flowing into cavity 2004 is reduced. Thus 30% of the volume of chamber 2006 is the maximum ink drop volume (50% at 0.5 atmospheres). The above applies to the case of temperature change, however, even if the temperature increases by 50°C, the amount of outflowing ink is smaller than that under the above-mentioned pressure drop.

If in the opposite case, atmospheric pressure rises, the low pressure air caused by a stationary ink head above chamber 2006 differs greatly from the increased ambient pressure, so there is a way to , so that the pressure difference returns to the practice trend of the predetermined difference. In this case, similar to the practice of supplying ink from the chamber 2006, the meniscus formed by the compressed ink absorbent 2003 near the bottom end of the chamber wall 2005 is broken, so that air is mainly introduced into the ink chamber 2006 to form a pressure equilibrium state. Therefore, the internal pressure of the ink supply part is difficult to change when there is no other influence on the recording device. In the foregoing example, when the ambient pressure returns to the original state, the amount of ink corresponding to the air introduced into the chamber 2006 Flows from cavity 2006 into cavity 2004. Thus, similar to the previous embodiments, the amount of ink in chamber 2004 temporarily increases as the air-liquid interface rises. Therefore, similar to the initial state, the internal pressure of the ink is also temporarily slightly higher than that in the steady state, but this influence on the ink ejection characteristics of the recording head is so small that it can be ignored. The above-mentioned problems arise in the case where, for example, a recording device used in a low-pressure environment such as a high altitude is moved to a low altitude. Even in this case, the inventive change is simply the entry of air into cavity 2006 . When the recording device is moved to a higher altitude, all that occurs is a slight increase in the internal pressure of the ink supply portion. There is no practical problem because the use of the device at excessively superatmospheric pressures is impracticable.

The ink is reliably retained in the ink chamber 2004 by the compressed ink absorber 2003 from the start of use until the change occurs, and since the ink chamber 2006 is closed, there is no leakage from the opening (air passage and ink supply portion), Thus easy to use.

The desired working conditions of the ink chamber structure and the compressed ink absorber for this hybrid type of ink tank will be described as follows:

The relationship between the ink absorption amount of the compressed ink absorber 2003 and the ink chamber structure is considered based on not generating ink leakage when the surrounding environment changes. The determination of the maximum ink uptake of cavity 2004 is based on the amount of ink flowing out of cavity 2006 under worst-case conditions and the amount of ink remaining in cavity 2004 when cavity 2006 provides ink into cavity 2004 . The ink chamber 2004 should have at least enough space to accommodate the maximum amount of oil that the compressed absorbent can absorb. Regarding the estimate of the amount of oil that the ink chamber 2006 can flow out under worst conditions, the amount of ink that flows out of the ink chamber 2006 is maximum when the pressure drops to 0.7 atmospheres, leaving 30% of the space in the chamber 2006 at this time. If ink below the bottom end of the chamber wall is also absorbed by the compressed absorbent in chamber 2004, it can be assumed that the ink remaining in ink chamber 2006 (30% space) has leaked out. When the worst conditions reached 0.5 atmospheres, 50% of the cavity 2006 was filled with ink. The air in chamber 2006 expands more due to pressure reduction if the amount of ink remaining is less. A large amount of ink is thereby discharged. However, the maximum amount of ink flowing out is less than the amount of ink contained in the ink chamber 2006 . Therefore, assuming 0.7 atmospheric pressure, when the remaining ink is not more than 30%, the remaining ink volume is smaller than the space occupied by the expanding air, so that the ink volume of the newly flowing cavity 2004 is reduced. Thus 30% of the ink space in chamber 2006 is the maximum leakage of ink (50% at 0.5 atmospheres).

The size of the passage between the ink chambers formed at the bottom of the ink chamber wall 2005 is not smaller than the size at which the ink in the chamber 2006 cannot be formed at the passage. Cavity 2006 is closed above. The first case as described. Said size selection should be based on the maximum flow rate provided from the ink supply part (the ink supply speed during the stable printing or absorbing operation time of the recording device) to smoothly carry out air-liquid exchange when passing through the channel opening, taking into account the ink flow rate. properties, such as viscosity. However, this consideration should pay attention to the fact that when the upper surface of the ink remaining in the chamber 2006 is lower than the bottom of the ink chamber wall 2005, the internal pressure of the ink supply part is temporarily in the positive direction as mentioned above. The influence of this factor on the ink ejection quality of the recording head should be avoided when selecting the size.

According to the description of the working process of this ink tank, in this mixed type ink tank, the internal pressure in the ink supply part is maintained by the compressed ink absorber close to the wall of the ink chamber, so in order to maintain the desired The internal pressure when ink is supplied in the chamber 2006 can appropriately adjust the capsule force of the compressed ink absorber 2003 near the bottom portion of the ink chamber 2005. In particular, the compression ratio or initial pore size is selected such that the bladder force of the compressed ink absorber 2003 near the bottom end of the ink chamber wall 2005 can generate the internal pressure required for the recording process. For example, when the internal ink pressure of the ink supply part is -h(mmaq), the pressure of the compressed ink absorber 2003 near the bottom of the cavity wall 2005 can generate a capsular force of absorbing hmm. If the structure of the compressed ink-absorbing substance is simplified, its pore diameter P ₁ can satisfy the relationship of P ₁ =2γcosθ/ρgh. ρ represents the specific gravity or density of the ink, γ is its surface tension, θ represents the angle at which the absorbing substance contacts the ink, and g represents gravity.

During ink supply from the chamber 2006, when the air-liquid interface of the ink in the chamber 2004 is lower than the upper end of the ink supply portion, air enters into the recording head. Therefore the above-mentioned interface should be maintained higher than the upper end of the ink supply portion. Thus, the compressed ink absorber 2003 located above the ink supply part has a capsular force capable of absorbing (h+i) ink height, where i represents the distance imm of the air-liquid interface above the top of the ink supply part . Similar to the above, if the structure of the compressed ink absorber is simplified, its pore diameter P ₂ should satisfy P ₂ =2γcosθ/ρg(h+i).

The height i (mm) in the above equation needs only to be higher than the top end of the ink supply portion. The ink absorption force (capsule tube force) gradually decreases (if the absorber material is the same, its pore size _P3 gradually increases) (Figure 35), or the whole tube force of the compressed ink absorber decreases to only close to the ink chamber wall 2005 ( FIG. 36 ), so that the air-liquid interface also gradually decreases toward the wall of the ink chamber, which is located inside the absorber 2003 and located in the chamber 2004 . The change of the capsule force is consistent with the capsule force at the bottom end of the lumen wall 2005 (if the same material is used, P ₁ is satisfied).

If the present ink tank is not subjected to collision tilt, sudden temperature change or other special external force, the bladder tube force of the portion of the absorbent 2003 below the air-liquid interface may be any value. However, in order to supply the remaining ink in the cavity 2004, even if such an external force is conducted or the ink in the cavity 2006 is completely exhausted, the capsule tube force gradually increases toward the ink supply portion (the pore diameter P of the pores) ₄ ), this increase is greater than the capsule force (pore diameter P ₁ ) at the bottom of the ink cavity wall 2005 at the ink supply part (pore diameter P ₅ ) ( FIG. 37 ). That is, the adjustment of the capsule force should be suitable: the capsule force at the end of the cavity wall should be smaller than the capsule force immediately above the part provided by the ink, preferably, (capsule force at the bottom end of the cavity wall)<(ink cavity The relationship between the capsular tube force at the lower part of the middle part) < (the capsular tube force at the upper part of the ink cavity) < (the capsular tube force provided immediately above the part) < (the place where the ink is provided).

If the structure of the compressed ink absorber 2003 is simplified, the pore meridian i satisfies P ₁ =P ₂ , preferably P ₁ >(P ₃ P ₄ )<(P ₂ P ₅ ).

The relationship between P ₃ and P ₄ and the relationship between P ₂ and P ₅ can be consistent according to the compression ratio, such as: P ₃ <P ₄ , P ₂ <P ₅ , or P ₃ =P ₄ or P ₂ =P ₅ .

Referring to Figures 35, 36 and 37, selected compression ratios are shown. In this example, the above-mentioned relationships can be satisfied by selecting the same ink absorber 2003 and adjusting the compression ratio. In the figure, A351, A361, A371, indicate the air-liquid interface, while arrows A352, A362, and A372 indicate the compression ratio of the rising compressed ink absorber.

Fig. 38 shows a comparative example 3 in which the capsular force of the compressed ink absorber 2003 at the ink supply is not greater than that near the lumen wall. This figure shows a situation in which ink has been supplied from cavity 2004 to show a portion thereof. In this comparative example, the air-liquid interface A381 is formed near the bottom portion of the ink chamber wall 2005, and the conduction portion between the chambers 2004 and 2006 is located on the side of the air phase. In this case, the ink can no longer be provided from the cavity 2006, and the air introduced through the air passage portion 2013 is directly sent to the recording head through the ink supply portion, and the ink tank at this time has been exhausted. Cannot continue working.

What Fig. 39 shows is a comparative example 4, in the example, near the bottom part (Fig. 39 (B)) or cavity wall side (Fig. The power is opposite to the embodiment of the present invention.Similar to comparative example 3, before the air-liquid interface A391 was formed near the bottom end of the chamber wall 2005, the air-liquid interface fell below the top of the ink supply part, so that the ink It is impossible to be supplied from the cavity 2006, whereby the air entering through the air passage 2013 is directly sent to the recording head, and the ink tank cannot work at this time.

The foregoing description is about a monochrome recording apparatus having one recording head. But described embodiment also is applicable to the recording device (such as BK, C, M, and Y) that has 4 recording heads of a colored ink ejection, and this device can eject the ink of different colors; The recording head is a recording device that ejects ink of 4 colors. In this case, additional facilities are required to limit the connection position and direction of the replaceable ink tank.

In the foregoing embodiments, the ink tank is replaceable, but these examples are applied to a recording head disc which integrates the recording head and the ink tank.

Example 11

40 and 41 show a device according to an eleventh embodiment. Two additional ink chambers 2008 and 2009 are arranged to communicate with the chamber 2006 . In the example of this variation, the ink consumption sequence is: ink chambers 2006, 2008 and 2009. In this modified example, the ink chamber is divided into 4 chambers to better prevent the leakage phenomenon caused by the environment, pressure reduction and temperature change described in the previous example. If the air in the cavities 2006 and 2008 expands under the situation of Fig. 41, the expanded part of the air in the cavity 2006 is released through the cavity 2004 and the air channel 2013, and the expanded part in the cavity 2008 enters the cavity 2006 by the flow of the ink And to chamber 2004. The cavity 2004 thus has a buffering function. The ink holding capacity of the ink absorbent in the cavity 2004 can thus be determined based on the amount of leakage from one cavity. Therefore, the volume of the compressed ink absorber 2003 can be reduced to be smaller than that in Example 10, so that the ink holding amount can be increased.

Example 12

Fig. 42 shows a twelfth embodiment in which the compressed ink absorber in the ink chamber 2004 is divided into three parts, each part having a specific function. In Figure 42, the compression ratio of the compressed ink absorber near the ink delivery portion (which occupies most of the space in 2004) is relatively high to increase the balloon force. The compression ratio of the absorbent near the end of the lumen is low, but sufficient to provide sufficient balloon force needed to generate the internal pressure required to deliver the ink (A423 represents a relatively low compression ratio). In addition, a substance A424 with an even lower compression ratio is placed along the cavity wall to facilitate the formation of the air-liquid interface A421 at the bottom end of the cavity. In this embodiment, the compressed ink absorber 2003 is divided into three parts, compressed beforehand, and then set. Doing so makes the ink tank manufacturing process a little more complicated, but the compression ratio (thereby causing the bladder tube force) can be adjusted to an appropriate degree at the corresponding location. In addition, the above-mentioned low-capacity absorber is arranged on the lateral wall of the chamber, thereby allowing the internal pressure of the ink supply portion to rise to a predetermined level more quickly.

Example 13

Fig. 43 shows the thirteenth embodiment. Similar to the twelfth embodiment, the compressed ink absorber 2003 is divided into 3 pieces, the A432 part has a high compression ratio, the A434 part has a low compression ratio, and the small compression ratio part (middle bladder tube force) A433 is located in the chamber 2006 bottom. In this embodiment, even if the ink level in the cavity 2006 becomes lower than the bottom end of the cavity wall 2006, the entry of ink into the cavity 2004 can be suppressed. Thereby, the internal pressure change of the ink supply part is reduced. Thereby, the degree of conductance between the cavities can also be increased, so that the confinement aspect in the ink tank is slightly reduced. In this figure, A431 represents the air-liquid interface. But in this embodiment, as shown in Figure 44, if the ink absorber is further partially (P441) compressed at the bottom end of the cavity wall when the ink absorber is installed, the compression ratio near the cavity 2006 will locally change High, causing a local increase in capsular force. There is then the possibility that air is blocked between locations close to chamber 2004 which has a normal compression ratio, whereby less balloon force causes a meniscus to form, preventing the supply of ink from chamber 2006 . These should therefore be avoided.

As described above, according to Embodiments 10, 11, 12, and 13, the hybrid type ink tank was modified to provide the air passage to the supply portion of the recording head. Also provided is an ink supply chamber containing a compressed ink absorber with adjusted bladder force, and one or more ink chambers communicating therewith. The capsular force of the ink absorber, at least the entire tube force at the upper part of the ink supply part to the recording head, is greater than the capsular force of the absorber at the communicating part of the cavity, thereby maintaining stable ejection and preventing leakage . Accordingly, the ink tank is easy to handle and has a high ink retention rate.

Example 4

During the pressure drop test of the aforementioned ink tank, a problem was found that the ink leaked when the ink had the composition of Comparative Ink 3 to be described later. Therefore, the means of preventing leakage varies according to individual ink tanks. Various investigations and experiments by the inventors have revealed that the cushioning effect of the ink is affected by the resonance between the ink and the tank.

Figures 14, 45 and 46 show a comparison of leaking ink tanks. In FIG. 45, (I) represents a range in which the ink absorber has not been in contact with ink, (II) represents a range in which ink has been absorbed once, and (III) represents a range containing ink. Figure 14 shows the initial state of the ink tank, and Figure 45 shows a state where the available ink in the cavity 3004 has been consumed, and now there is only 1/5 of the ink in the cavity 3006. FIG. 46 shows that an increase in ambient pressure or a change in temperature that occurs in the state of FIG. 45 causes the air in chamber 3006 to expand. This allows time for the ink in chamber 3006 to be expelled into chamber 3004. Part of the ink is absorbed by the part of the absorbent that once absorbed the ink, but the other ink is not absorbed by this part, but along the ink tank wall or the gap between the walls and the ink absorbent, from the air Leak out via 303.

The reason for the above-mentioned phenomenon can be considered that an ink absorber that has never absorbed ink exhibits a weak absorbency. The ink-absorbing substance that has absorbed ink has a different surface state that is favorable for absorbing ink. These have been confirmed in the following manner. An unused compression absorbent (polyurethane foam) and a compression absorbent that had absorbed the ink once were immersed in the ink, and the ink absorption height was measured. (It was found that the former can hardly absorb ink (several millimeters), while the latter can absorb several centimeters, thereby confirming their obvious difference in absorption characteristics. On the ink tray of this embodiment, ink can be injected into the cavity 3006 to its initial The volume limit of state.In addition, ink also can be injected in the chamber 3004, to the quantity limit that it keeps.Therefore considering above-mentioned point of view, ink is injected into cavity 3006 according to its volume limit, then ink is injected in cavity 3004 , so that before use, the absorbent is wetted. Thereafter, in order to maintain a predetermined vacuum degree after the ink tray is separated, an appropriate amount of ink can be released from the cavity, so that the amount of ink in the cavity 3004 is less than the retention limit.

After the tank is separated, the oil in cavity 3004 is consumed and thereafter the oil in cavity 3006 is consumed. When the oil in the cavity 3006 with buffer function is consumed, the ink absorber in the cavity 3004 has been soaked, thus, it can easily absorb ink, and the buffer effect is also completed at the same time, thereby effectively preventing the ink from Air channel outflow. Such a tank was loaded into an ink jet recording device, and its pressure drop was tested. As a result, it was found that no oil leakage occurred in any of the tanks, and the record printing results were of high quality.

In order to make the ink tank with the above functions, it should be considered that the ink absorber should be wetted with ink, or soaked with other media with the property of wetting, and then loaded into the oil tank. However, this may require a drying step or the like, and if a medium other than ink is used, consideration should be given to the possibility of damage to the heater due to dissolution of this medium into the ink. It should also be considered to use inks that work well with the absorbent. However, such inks generally have good paper penetration, so the printed ink penetrates irregularly along the fibers on the paper, reducing the printing quality.

Figures 47 and 48 show variant embodiments of the present invention. (I), (II) and (III) in the figure show contents similar to those of (I), (II) and (III) in FIG. 45 . In this example, there are two ink chambers 3007 and 3008 which communicate with chamber 3006 . In this embodiment, the order in which ink is consumed is: chambers 3006, 3007 and 3008. In this modified example, the ink chamber is divided into 4 chambers to prevent oil leakage when the pressure drops and the temperature changes, which has been described in the previous embodiment. When the air in chambers 3006 and 3007 expands as shown in FIG. 48, the expanded air in chamber 3006 is released through the air passage through chamber 3004. The release of the expansion volume in chamber 3007 is through the flow of ink from chambers 3006 and 3004. In this manner, cavity 3004 becomes a buffer cavity. The ability of the compressed ink absorber in cavity 3004 to hold ink can be determined by the amount of oil that leaks from the cavity. In this case, the entirety of the compressed ink absorber in 3004 performs a single ink absorption, thereby enabling the advantageous effects described above. Because the buffer cavity (cavity 3004) can be reduced in size, the amount of ink that settles when it is transferred after being filled during the manufacturing process can be reduced.

Example 15

Referring to Fig. 49, Embodiment 15 will be described. The basic structure of its recording head is the same as that shown in Figure 1. The interior of the replaceable ink tank 3001 is divided into 4 chambers, a, b, c, d, "they communicate with each other at the bottom, and the ink absorber 3002 with adjusted bladder tube force is loaded into chamber a and other chambers The communicating parts between the other cavities are used as ink supply parts without gaps. The cavity d with the air channel 3003 is equipped with a buffer absorbent to prevent ink from leaking. This constitutes such a hybrid ink tray.

In the state of Fig. 49, about half of the ink in the cavity 3007 has been consumed. (In the initial state, cavities 3004, 3006 and 3007 are fully filled with ink). When the ink is further consumed, as shown in Figure 50, when the ink in the cavity 3007 is exhausted, the ink provided by the cavity 3006 will be consumed, and the ink will continue to be consumed after the state shown in Figure 50, and when the cavity 3006 When the ink in the chamber 3004 is exhausted, the ink absorber in the chamber 3004 starts to supply ink, and when the ink in the chamber 3004 is also exhausted, the ink tank is replaced.

Fig. 51 shows the principle of ink supply and ink pressure reduction of this Embodiment 15. The ink 3201 in the ink chamber on the left side of Figure 51 has been exhausted, and the pressure in the chamber is consistent with the atmospheric pressure due to the communication between the air channel and the chamber. The ink is supplied to the recording head through the communication part between the chambers, and at this time, the ink 3201 is supplied from the chamber communicated with the chamber having atmospheric pressure. The ink absorber 3201. The pressure drop in the ink chamber corresponds to the oil consumption. Thereafter, air breaks through the compressed ink-absorbent meniscus between the cavities into the cavities where a pressure drop occurs due to ink outflow. The ink provides part of the internal pressure maintained at a predetermined level by the bladder force of the compressed absorbent between the lumens.

Fig. 52 shows the variation of the internal pressure of the ink supply portion of the replaceable ink tank of Embodiment 15, which variation is caused by the consumption of the ink. The generation of internal pressure is due to the capsule tube force of the buffer absorbent or the ink absorbent, but the internal pressure is provided by the oil, by the entirety of the compressed ink absorbent (compressed part) on the passage between the chambers 3008 and 3007. Tube force is generated so that when ink is supplied from chamber 3007, a steady ink pressure can be maintained as previously described. As ink is further consumed, chamber 3006 begins to supply ink. At the start of ink supply, the internal pressure of the ink supply portion slightly changes. This phenomenon is believed to be related to the internal pressure measurement provided with the ink and to the occurrence of transient pressure drop conditions in chambers 3007 and 3006 . However, it has been confirmed that this variation does not cause significant problems to functions such as the operation of the recording head.

When the ink in the chamber 3006 is consumed stably, the internal pressure is also stable. When the ink in chamber 306 is depleted, chamber 3004 begins to provide ink. During the stable supply of ink shown in Fig. 52, there was no adverse effect on the recording work.

Figure 53 illustrates the function of the cushioning absorbent substance 3203. As the atmospheric pressure changes and the temperature rises, the air in the chamber 3007 expands, so that more ink flows out of the chamber 3007. In this embodiment, excess ink that flows into cavity 3008 is retained by the cushioning absorber. The ability of the cushioning absorbent 3300 to retain ink was rated at 30% of the maximum ink leakage from the cavity 3007 at 0.7 atmospheres. Ink that leaked into cavity 3008 and remained in buffer storage 3203 returns to cavity 3007 when the atmospheric pressure returns to the level before the pressure drop. This phenomenon also occurs when the temperature of the ink tank changes. But when the temperature changes, even if the temperature rises to 50°, the leakage caused by the temperature change is smaller than the leakage caused by the pressure drop.

In this case, the buffer absorbent is designed according to the maximum leakage. However, during the pressure drop test, a problem was found that ink was leaking from some ink tanks, so the nature of the leak prevention measures depends on the individual tanks. It has been found that this occurs due to resonance between the ink and the absorbing cushion of cavity 3008 .

In Example 15, the cushion absorbent 3203 was ink-absorbed before use. It has been confirmed that when the air in the cavity 3007 expands due to temperature rise or pressure drop, causing ink to be discharged into the cavity 3008, the buffer absorbent in the cavity 3008 absorbs the inflowing ink, thus no leakage occurs.

As mentioned above, the chamber 3008 is an ink buffer chamber, so it is preferable not to inject ink at the initial stage of use. Therefore, in this embodiment, a limited amount of ink is injected into the cavities 3004, 3006, and 3007, and a limited amount of ink is also injected into the cavity 3008. Thereafter, the ink in 3008 is removed to ensure its buffering capacity.

The ink tank thus constituted was loaded in an ink jet recording device, and then subjected to a pressure drop test. The results confirmed that not only were there no leaks, but the print quality was recorded to be good and stable.

As described above for Embodiments 14 and 15, a tank tray is mounted on it, and the tray includes an ink supply chamber containing an ink absorbent with adjusted capsular force and one or more ink supply chambers for holding ink and An ink chamber communicating with the supply chamber. The absorbent in the cavity has been wetted with ink, so that ink leakage does not occur even if the usage environment of the recording device changes, regardless of whether the device is in use or stopped. Therefore, ink usage efficiency and printing quality are high.

Example 16

In the ink tray of the above-mentioned embodiment, when the supply chamber containing the ink absorber becomes empty: in some cases, the refilling work is somewhat difficult.

Fig. 61 shows the state where the ink is to be refilled into the tank, where the ink in the supply chamber has been exhausted. Even if the ink in the supply chamber (4004) is used up after the ink in the chamber 4006 has been depleted, a small amount of ink remains in the ink absorber. In various parts of the absorbent, the ink forms a meniscus. The meniscus in the absorber in cavity 404 prevents dense injection of ink when ink is to be supplied to chamber 4006 that does not contain ink absorber 4202 . While retaining large bubbles, as shown in A611. When such an ink tank is coupled to the recording head, the inflow of ink is not sufficient due to the presence of the above-mentioned air bubbles, thereby easily stopping.

In this case, the operator will not pay attention to the emptying of the chamber 4006 because the ink is contained in the absorbent in the chamber 4004, so the recording work will be performed even though the oil in the chamber 4006 is exhausted. The operator will know that the ink in the chambers 4004 and 4006 is exhausted only when the recording operation cannot be performed due to the oil in the ink absorber in the chamber 4004 being exhausted. At this time, even if the chamber 4006 is refilled, the incoming ink does not come into contact with the ink contained in the absorbent in the chamber 4004, so the oiling cannot be performed, and as a result, no air bubbles remain in the absorbent 4202 in the chamber 4004.

To solve this problem, the ink supply chamber included in the oil tank should have an ink supply portion for supplying oil to the recording head, an air passage and an ink absorber placed at the center, at least one chamber should communicate with the ink supply chamber, and accommodate A device for detecting the reduction of the amount of remaining oil during the presence of ink and the predetermined amount of ink remaining in the ink chamber.

The following description is about the above-mentioned device for detecting the amount of oil.

Fig. 54 shows an example of a control system according to the present invention, which includes a microcomputer controller having an A/D converter, a voltage converter 4300 and an alarm device 4400. Reference numeral 4010 denotes a recording head. The warning device may be of the LED or similar type, or of a sounding type such as a buzzer or similar, or a combination of the above. A main scanning mechanism 4500 for scanningly moving the carrier HC includes a motor for feeding recorded information. The mark √ indicates the detection signal of the remaining oil in the oil tank. In this embodiment a constant current flows between the two electrodes in the chamber 4006, and the amount of ink remaining in the chamber 4006 is determined by the resistance between the two electrodes. In this case, the relationship between the remaining oil amount and the electrical resistance is shown in FIG. 66 .

As shown in Figure 55: when the oil level in the cavity 4006 is lower than the upper one of the two electrodes 410, the resistance between the two electrodes increases sharply, and a corresponding voltage is generated. This voltage is transferred to the A/D converter of the controller for AD conversion directly or through a voltage converter 4300 . When the measured value exceeds a predetermined level R+h, the operator will be notified by activation of the alarm device 4400 . Inject ink. At this point, the host computer may be stopped or will stop working soon.

As the consumption of ink ceases, a small amount of ink remains in cavity 4006, so ink can be refilled into the absorbent in cavity 4004, whereby the ink tank can be reused.

Fig. 56 shows how the internal pressure of the ink supply portion of the replaceable oil tank according to this embodiment changes according to the amount of ink consumption. In the initial stage, its internal pressure (negative pressure) is generated by the capsule tube force of the compressed ink absorbent in the cavity 4004, but as the ink in the cavity 4004 is consumed, the internal pressure generated by the capsule tube force gradually increases, and this change It is produced according to the compression ratio change of the compressed absorbent 4202.

As ink is further consumed, ink consumption in chamber 4004 proceeds steadily, and ink in chamber 4006 starts to be consumed, air enters chamber 4006 (in the manner previously described), and a stable internal pressure is maintained. When the ink consumption in 4006 has reached the predetermined amount, the eighth amount detector starts to work, and performs the functions of impelling, oil filling and printing work stop. Thereby, the ink in the cavity 4004 can be filled with oil before it is consumed to no more than a predetermined value, and the oil filling work is carried out when it is beneficial for injection.

As for the method of injecting ink, Fig. 57 shows an example. A plug hole in an ink supply portion 4005 of the chamber 4006 is opened, and ink is injected into the chamber 4006 through the tube 4052 and the like. After injection, the plug 4051 is plugged. The method of re-injection is not limited to this, and other methods can also be used, and the location of the provided part 4005 is not limited to the above. The ink tray can then be reused.

In the foregoing, the remaining amount of ink is detected by the resistance between the electrodes in the tank, but not limited thereto, it can also be detected by mechanical or optical means.

In this embodiment, the oil tank is of a replaceable type, however, the ink jet recording head disk may have the recording head and the ink tank integrally thereon.

Example 17

Referring to Figures: 58, 59, and 60, Embodiment 17 will be described. Two chambers 4007 and 4008 are in fluid communication with chamber 4006 . In this example, the ink consumption sequence is: chambers 4006, 4007 and 4008. The ink chamber in this embodiment is divided into 4 parts to prevent ink leakage caused by ambient pressure drop and temperature rise as described in Embodiment 16. For example: when the air in chambers 4006 and 4007 expands in the state shown in FIG. 58 , the expansion in chamber 4006 is released through the air passage and chamber 4004 . As shown in FIG. 59 , the amount of expansion in chamber 4007 is released as ink flows into chambers 4006 and 4004 . The ink chamber 4004 is then given the function of a buffer chamber. Thus, the ink retention capacity of the compressed ink absorber 4002 in the cavity 4004 can be determined by considering ink leakage from one cavity.

In this example, ink is consumed from chambers 4006 and 4007 sequentially. The ink depletion then goes to the last chamber 4008, depleting the ink in the chamber 4004 until terminated. To measure the amount of ink remaining in chamber 4008, chamber 4008 is filled with telegraph 4100 (shown in FIG. 60). The cavity 4006 is provided with an injection hole. In this embodiment, the remaining ink is measured in chamber 4008 only. Thus, cavities 4006 and 4007 can be filled with ink. If the electrodes are placed at a considerable height in Embodiment 16, when the electrodes detect the limit, the amount of ink remaining in the non-absorbent chamber can be reduced, making efficient use of the space.

In this embodiment, similar to embodiment 16, when the amount of oil in the chamber 4004 containing the absorbent is insufficient, it can be refilled.

Example 18

Fig. 62 shows embodiment 18, the tank wall of which is made of transparent or translucent material, so that the remaining ink amount can be seen by optical means. In this example, a reflective lens such as a mirror is placed on the wall of the cavity 4006, and a photosensitive member including a light directing member 4043 and a light receiving member 4044 is placed outside the oil tank. The light emitting member 4043 and the receiving member 4044 may be placed on a rack or at a main body location with a recovery system.

In Fig. 62, 4043 emits light according to a predetermined angle, and light receiving member 4044 receives light through the reflective lens. For example, the light emitting member 4043 is an LED element, and the receiving member 4044 is a phototransistor or the like. In Fig. 62, (a) is the ink-filled state. At this time, the light emitted by 4043 is blocked by the oil in the cavity 4006, so 4044 cannot receive light, and thus the output of the detector is small. If the oil is consumed to the state of (b) in Figure 62, since there is no ink blocking the light, the output of the detector is high, when the light energy (detector output) accepted by the 4044 exceeds a predetermined limit, an additive will be generated. Oil warning sign.

Figure 63 shows an alternative embodiment in which the light emitting and receiving members are placed on opposite sides of the tank. Fig. 63(a) is a plan view, and Fig. 63(b) is a front sectional view. In this example, cavity 4006 is also made of transparent or translucent material. Therefore, there is no need for reflective lenses, and since the light is received directly, the detection effect is good.

In the foregoing, the description has been made with regard to a single tank, but the present invention is also applicable to a color ink jet recording apparatus having a plurality of recording heads to jet black, cyan, magenta and yellow. The present invention is also applicable to jetting different colors using one recording head.

For different colors, different thresholds can be used, and filter paper can be used to select predetermined wavelengths according to different ink colors, so that residual ink can be detected through the light conductivity of the ink.

The aforementioned oil tank is replaceable, however, it is in a form having an integral recording head and oil tank, ejection head disk.

Example 19

Figure 64 has shown, embodiment 19, among the figure, the ink chamber among the embodiment 16 is divided into two parts, and one of them (4007) is replaceable. What (a) among Fig. 64 shows is the state that remaining ink quantity detector is activated, and can replace a new cavity 4007 that is filled with ink to replace the ink cavity 4007 that has been used up at this moment. Figure 64(b) shows exactly this replacement state. Figure 64(c) shows that the above replacement has been completed. At this time, the valve plug 4052 at the bottom of the oil chamber is pushed away by the valve plug 4053 at the top of the chamber 4006, so that the ink is injected into the chamber 4006. This eliminates the need for tubing or injectors and does not dirty the operator's fingers. Therefore, the cavity 4004 and the cavity 4006 can communicate with each other and only need to change one part, which is economical.

In Embodiment 19, the ink remaining amount detecting member is not limited to the form of inter-electrode resistance, and it may be of the type described in Embodiment 18 or other types. A further method of detecting whether there is continuous flow of ink between the chamber 4004 and the chamber 4006 may be considered for determination. One structure of this method is to arrange two electrodes 4100 on both sides of the two-chamber channel respectively.

In this embodiment, the recording head and ink are separable. But the recording head can also be integrated with the ink tank having the chambers 4004 and 4006.

According to the above description of Embodiments 16-19, the oil tank has a portion for supplying ink to the recording head and an air passage, and it includes an ink supply chamber containing an ink absorbent, and at least one chamber for holding ink In communication therewith, in the chamber containing the ink, there is a detection member; whether the amount of ink is sufficient is determined, and the result of the detection is informed to the operator, so that the recording operation can be stopped and the oiling work can be performed.

The inventors investigated inks suitable for use in the foregoing embodiments of the present invention, and the most suitable inks exhibited stability of their air-liquid exchange portion against vibration of the ink, and stability against changes in environmental conditions.

Inks suitable for use in the tanks of the foregoing embodiments will be described below.

The basic components of the ink are at least water, pigments and water-soluble organic solvents. Organic solvents are low-volatility and low-viscosity substances with high water solubility. The following are examples of such solvents. Amides such as dimethylformamide and dimethylacetamide, ketones such as acetone; ethers such as dioxane and tetrahydrofuran; polyglycols such as polyethylene glycol and polypropylene glycol; ethylene glycol, propylene glycol, butylene glycol, triethylene glycol, thiodiglycol, hexylene glycol and diethylene glycol; lower alkyl ethers of polyhydric alcohols, such as ethylene ethylene glycol Methyl ether, diethylene glycol monomethyl ether and triethylene glycol monomethyl ether; monohydric alcohols such as ethanol and isopropanol; in addition, glycerol, 1,2,6 hexanethiol, N-methyl- 2-pyrrolidone, 1,3-dimethyl-2 imidazolidinone, triethanolamine, sulfolane and dimethyl sulfoxide, etc. The water-soluble organic solvent composition is not particularly limited. But it accounts for 1-80% by weight. The colorant used in the present invention may be a pigment or a dye, and the dye may be a water-soluble acid dye, toner, basic dye, reactive dye or the like. The dye composition is not limited, but preferably accounts for 1-20% of ink weight.

Surfactants are used to adjust the surface tension of liquids. Examples of surfactants are: anionic activators such as fatty acid salts, perethyl alcohol sulfates, alkylbenzene sulfonates, and per alcohol phosphonate salts; cationic active agents such as fatty amine salts and quaternary ammonium salts; Ethylene oxide adducts of ethanol, ethylene oxide adducts of alkylphenols, aliphatic ethylene oxide adducts, ethylene oxide adducts of high alcohol fatty acid esters, ethylene oxide adducts of high alkylamines, lipids Ethylene oxide adducts of acid amides, ethylene oxide adducts of polypropylene glycol, high glycolic fatty acid esters of polyols and alkanolamine fatty acid amides, and anionic surfaces of amphoteric surfactants of amino acids and trimethylammonium lactones active agent. There are no particular restrictions on the surfactant, but the best anionic surfactants to be used are high alcohol ethylene oxide adducts, alkylphenol ethylene oxide adducts, ethylene oxide-propylene oxide copolymers, acetylene ethylene oxide adducts, Ethylene oxide adducts of alcohols. Furthermore, the number of moles of added ethylene oxide should be in the range of 4-20, especially in the ethylene oxide adduct. There is no particular limitation on the addition amount of the surface active additive, but it is preferably 0.01-10% of the total weight. The surface tension can be controlled by the above-mentioned water-soluble organic solvent.

In addition to the above-mentioned ingredients, the initial liquid may contain viscosity modifying substances, pH adjusting agents, antifungal agents or antioxidants as required.

The viscosity of the ink is 1-20cp and the surface tension should be 25-50dyne/cm. If the surface tension of the ink is within this range, the liquid surface of the recording head will not break when the machine is not in use, so that the ink will not flow out from the recording head hole.

The amount of ink contained in the ink pan can be appropriately determined as its internal volume. In order to maintain the vacuum when the disc is removed, the ink can be filled to the limit. However, the amount of ink in the vacuum product may be lower than its holding capacity, so the ink holding capacity of the vacuum product refers to the amount that may be held.

The inks and comparative examples according to the examples of the present invention are described below.

Mix water and water-soluble organic solvent, add dye, stir for 4 hours, then add surfactant, and then filter to remove foreign matter. The prepared ink is injected into the ink tray in Fig. 11, and then the work of the device shown in Fig. 12 is carried out.

Below is a comparison of ink properties and recorded print results.

Example 1 case 2 cases 3 cases of 3 cases of 4 glycol 15 % 10 % 10 % 10 % cyclic ethanol 2 % glycerin 5 % sulfinyl 5 % surfron S-145 0.1 % (fluorine surfactant) ACETYLENOL EH 2 % (ethylene ethylene-oxiditne-oxidine bonus) dye 2.5 % 2.5 % 0.2 % 2.5 % of the water margin volume remaining amount remaining surface tension 31 (Dyne/cm) 25 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40

In use, the above inks of Examples 1-4 were exhausted smoothly and the print quality was very good.

Comparison Example 1 Comparison Example 2 Timanol 15 % glycerin 5 % surfron S-145 0.1 % (fluorine surfactant) ACETYLENOL EH Dyestuff 2.5% 2.5% water Residue Residue Surface tension 17.6(dy ne/cm) 7

When the ink of Example 1 was used, the color was cleared with a small amount of ink dripping from the recording head. When the ink of Example 2 was used, there was diffusion between the colors, and a small amount of ink dripped out of the recording head.

The yellow dye is Acid Yellow 23, the cyan dye is Acid Blue 9, the magenta is Acid Red 289, and the black dye is Pure Black 168.

Surface tension measurements were carried out by the Wilhelmy method at 25°C.

The following is the surface potential of a typical water-soluble organic solvent at 20°C-25°C:

Ethanol (22dyne/cm), isopropanol (22dyne/cm), cycloethanol (34dyne/cm), glycerin (63dyne/cm), diethylene glycol (49dyne/cm), diethylene glycol monomethyl ether (35dyne/cm cm), triethylene glycol (36dyne/cm), 2-pyrrolidone (47dyne/cm), N-methylpyrrolidone (41dyne/cm).

The desired surface tension is obtained by mixing with water.

A method of controlling the surface tension of an ink using a surfactant will be described below.

For example, to provide a surface tension of 28dyne/cm, add 1% sorbitan monolaurate and mix with water; to provide a surface tension of 35dyne/cm, add 1% polyoxyethylene-sorbitan monolaurate: 28dyne Not less than 1% ACETYLENOL EH (acetylene ethylene glycol-ethylene oxide adduct) is required per cm. If you want less tension, you can add 0.1% surflons-145 (perfluoroalkyl-ethylene oxide adduct) (available from A Sahi Glass Kabushiki Kaisha, Japan) to obtain a tension of 17dyne/cm. The surface tension can also be slightly changed with additional additives, and thus can be appropriately adjusted by those skilled in the art.

As above, the ink buffer is designed taking into account the maximum amount of leaked ink. It has been found that the cushioning effect is highly dependent on the ink composition.

Below is an example for comparison.

Comparative example 3

Dyes 4 parts

Glycerin, part 7.5

Thiodiglycol Part 7.5

Urea Part 7.5

Pure water Part 73.5

When ink is expelled from chamber 3006 to chamber 3004 (the air in chamber 3006 expands due to a decrease in pressure or an increase in temperature as shown in Figure 46), the problem that arises is that the ink is not absorbed by the absorbent material, but passes through the tank walls and Gaps between absorbents, or leaks through air channels.

Therefore, inks containing surfactants are used. The advantage of this ink is that the setting properties on copier bond paper or other plain paper are very good, i.e. colors are printed moderately without mixing (bleeding or the like), even when different colors are printed in close proximity The same is true. Therefore, overall coloring becomes possible. The following are examples of such ingredients.

Ingredient Example 5

Dye 4 parts

Glycerin 7.5 parts

Thiodiglycol 7.5 parts

Acetylene ethylene glycol ethylene oxide 5 parts

Adduct (m+n=10)

Urea 7.5 parts

Pure water 68.5 parts

When the ink described above is used, when the ink is expelled into the chamber 2004 due to the expansion of the air in the chamber 2006, it is absorbed by the ink absorbent in the chamber 2004, and the ink does not leak from the ink tray. The above-mentioned air expansion is caused by temperature rise or pressure drop as shown in FIG. 34 .

As previously described, the air-liquid phase boundary is maintained at a height when ink is supplied from chamber 2006 to chamber 2004, ie, the stationary head at the jetting site of the recording head and the vacuum portion of chamber 2006 and compressive absorbent pocket forces. Assuming that the average height of the gas-liquid phase boundary in the cavity 2004 is H at this time, when the ink in the cavity 2006 flows out due to changes in electrical pressure and temperature, the gas-liquid phase boundary in the cavity 2004 can be expected to be maintained at a higher on the h value. In an example of this embodiment, the total height of the ink in the cavity is 3 cm, and the cavity 2004 and the cavity 2006 each have a capacity of 6 cc. In the initial stage, the cavity 2006 is filled (6 cc), and the cavity 2004 (with compressed ink therein) Absorbent 2003, which is polyurethane foam) contains 4 cc of ink, and the porosity of the absorbent is not less than 95%. If it is assumed that the ink is completely contained within the pores of the absorbent, cavity 2004 can hold 6 cc of ink. The consumption of ink starts from the chamber 2004 first, and after a certain time, the ink in the chamber 2006 starts to be consumed, and the air-liquid phase boundary in the chamber 2004 is maintained at a certain level. At this level, the stationary head of the jetting portion of the recording head, the vacuum of the chamber 2006, and the bladder force compressing the ink absorber are in a state of balance. On average, the level (gas-liquid phase boundary) at this time is about 1.5 cm. If it is assumed that all the pores of the absorbent contain ink, the amount of ink in cavity 2004 is about 3 cc. At this point the maximum pressure is reduced to 0.7 atmospheres so that 1.8 cc of ink, which accounts for approximately 30% of the cavity 2006, can flow from the cavity 2006. Thus, cavity 2004 absorbs and holds approximately 3cc+1.8cc (approximately 2.4cm ink level) of ink. When the maximum pressure is reduced to 0.5 atmosphere, about 50% of the 3cc ink in the chamber 2006 can flow out from the chamber 2006, so that the chamber 2004 can absorb and maintain about 3cc+3cc (about 3cm high liquid surface) ink volume. Thus, the ink chamber 2004 has sufficient space to contain the volume of the absorber, as the volume of ink in its chamber and the volume of ink flowing in from chamber 2006. It can thus be seen that the determination of the capacity of chamber 2004 takes into account the amount of inflow from chamber 2006 into it.

The ink height H absorbed by the porous absorbent is generally compressed by the capsule force according to the following equation.

H=2γcosθ/ρgr, where γ is the surface tension of the ink, θ is the contact angle between the ink and its absorbent, ρ is the density of the ink, 9 is the strategy, and r is the average pore size of the absorbent.

It should be understood that in order to increase the ink retention capacity by increasing the height of H, it is necessary to consider increasing the surface tension of the ink, or reducing the contact angle between the ink and its absorber (cosθ increases).

Regarding the increase in surface tension, Comparative Example 3 has a relatively high surface tension (50 dyne/cm ² ). But as previously mentioned, the ink is not properly absorbed by the absorbent. For a decrease in the angle Θ, it means an increase in the wettability of the ink to the absorbent. To accomplish this, surfactants are used.

In the case of the ink of Example 5, the surface tension was small (30 dyne/cm ² ) due to the addition of the surfactant, but the wettability between the ink and the absorbent was improved. To improve penetration, improving ink wetting is more effective than increasing surface tension.

To compare the ink penetration, the compressed ink absorbent (polyurethane foam) was dipped into the inks of Example 3 and Example 5, and then the absorption height was measured. The ink of Example 3 was absorbed only to a height of a few millimeters, whereas the ink of Example 5 was absorbed to a height of more than 2 cm. It can be understood from this that the ink permeability is improved by adding the surfactant (Example 5), so that the ink can be fully absorbed by the absorbent. Even if the ink in the ink chamber flows out excessively due to pressure drop or temperature rise, it can be fully absorbed.

The selected penetrants include anionic surfactants, such as OT aerosols, sodium dodecylbenzenesulfonate, sodium lauryl sulfate, high alcohol-ethylene oxide adduct (formulation 1 chemical formula), amphoteric ethylene oxide Adduct (Recipe 2), Ethylene Oxide Propylene Oxide Copolymer (Recipe 3) and Acetylene Ethylene Glycol Ethylene Oxide Adduct (Recipe 4).

Anionic surfactants have a strong tendency to generate foam, but their performance in terms of color spread, color integrity, and glaze sulfur is poor, and they are not as good as nonionic surfactants. The following formulations indicate the use of nonionic surfactant supplements.

4 chemical formulas

where R is alkyl

where R is alkyl

where R is hydrogen or alkyl

In chemical formulas (formulations) 1 and 2, n can take a value of 6-14, and R can have 5-26 carbon atoms. In Chemical Formulas 3 and 4, m+n may take 6-14, and m and n are monomers, respectively.

Among the ethylene oxide nonionic surfactants, the absorptivity of the absorbent, the printing quality on the record and the spraying work are considered as a whole, and ethylene oxide adducts of acetylene ethylene glycol can be selected. Hydrophilicity and permeability can be controlled by improving the value of m+n of added ethylene oxide. If the value is less than 6, the permeability is good, but the water solubility is not good. If the value is too large, the hydrophilicity becomes too strong and the permeability becomes poor. If the value is greater than 14, the permeability is sufficient, but the jetting quality becomes poor. Therefore, the value is better in the range of 6-14.

The non-ionic surfactant can account for 0.1-20% of the total weight, if it is less than 0.1, the printing quality and permeability are not good enough. If it is greater than 20%, not only will there be no better effect, but the cost will increase and the reliability will decrease.

One or more surfactants mentioned above may be used in combination.

Inks can contain dyes, low-volatility organic solvents such as polyols to prevent clogging, or organic solvents such as ethanol to improve the stability of foam generation and the immobilization of prints on printed matter.

The present embodiment ink that the water-soluble organic solvent constitutes can comprise the polyglycol such as polyethylene ethylene glycol and polypropylene glycol; Alkylene glycol has 2-6 carbon atoms, such as ethylene ethylene glycol, propylene glycol , butanediol, triethylene glycol, 1,2,6-ethanethiol, hexanediol and diethylene glycol; lower alkyl ethers of polyols, such as ethylene glycol methyl ether, diethylene glycol monomethyl Base (or ethyl) ether and triethylene glycol monomethyl (or ethyl) ether; ethanol, such as methyl ethanol, ethyl ethanol, n-n-propyl ethanol, isopropyl ethanol, n-butyl ethanol, F-butyl ethanol, T-butyl ethanol, isobutyl ethanol, benzyl ethanol and cyclohexanol; amides such as dimethylformamide and dimethylacetamide; ketones and ketols such as acetone and bis Acetol; ethers, such as tetrahydrofuran and dioxane; and nitrogen-containing rings, such as N-methyl-2-pyrrolidone, 2-pyrrolidone, 1,3-dimethyl-2-imidazolinone.

Addition of water-soluble organic solvents will not affect print quality and jetting reliability. Polyols or their alkyl ethers are preferred. The content can account for 1-3% by weight, and pure water accounts for 50-90% by weight.

Dyes suitable for use in the present invention include direct colorants, acid dyes, disperse dyes, vat dyes or the like. The amount of the dye depends on the composition of the ink and the characteristics required therefor, and the ejection amount of the recording head or the like. Generally, the amount of dye is 0.5-15% by weight, and it can also be 1-7%.

By adding thiodiglycol or urea (or derivatives thereof), the ejection quality and clogging (coagulation) prevention performance of the ink are remarkably improved. This is considered to be an improvement in the coagulation of the dye in the ink. Thiodiglycol or urea (or its derivatives) can account for 1-3% by weight in the ink, and can also be added as required.

The main components of the ink of the present invention have been described above. Other additives can also be used in conjunction to achieve the purpose of the present invention. The additives may include viscosity regulators, such as polyvinyl alcohol, cellulose, and water-soluble resins; pH control agents, such as diethanolamine, triethanolamine, and buffer solutions, bactericides, and the like. For the type of ink that has a charged form used in jet recording, its oil droplets are charged when used, so some resistance adjustment agents, such as lithium chloride, ammonium chloride and sodium chloride, can be added.

The following is a comparative example

Comparative Example 4 3 parts

Dye 5 parts

Diethylene glycol 5 parts

Thiodiglycol 3 parts

Pure water 84 parts

In this case, when the ink is excessively discharged from the oil chamber into the ink absorber chamber under pressure drop or temperature rise change, the problem arises that the ink passes through the gap between the tank wall and the absorber or through the The air channel is leaking.

So use ink to add surfactant. Such inks have the advantage of very fast settling of print marks, whether on copy, adhesive or other paper. It also has the advantage that undue color overlapping does not occur even if different colors come into contact in recording printing, whereby uniform coloring can be performed. Below are examples of such inks.

Comparative Example 6

Dye 3 parts

Glycerin 5 parts

Thiodiglycol 5 parts

Ethylene oxide-propylene oxide polymer 3 parts

Urea 5 parts

Pure water 79 parts

When the present ink is used, it is absorbed by the ink absorber in the cavity, and even if a drop in pressure or an increase in temperature causes a large amount of ink to flow into the cavity with the absorber, the absorption is sufficient.

As described above, the ink tray of the present invention includes an ink supply chamber with an ink absorbent for adjusting the capsular force, and one or more ink chambers. It is characterized in that the ink contains a nonionic surfactant, so that when the external conditions change , The ink does not leak when the recording operation is in progress or stopped, thereby improving the ink usage efficiency.

Progressive embodiments 1-13 all have corresponding advantages, and if used in combination, the advantages will be even greater. In addition, the combination of the processes of Examples 14 and 15 and the structures of Examples 16-19, together with the above-mentioned ink, has a better effect of the present invention.

The invention is applicable to any ink ejection device, such as those using electromechanical transducers, such as piezoelectric elements. But it is particularly suitable for such a recording device, that is, a device that uses thermal energy of an electrothermal conductor, laser beam or the like to cause a change in the state of the ink to eject or discharge the ink. This is because recording with high density and high resolution performance has become possible.

The typical structure and operation principle described can be the same as those disclosed in US Patent Nos. 4,723,129 and 4,740,796, which are applicable to a so-called imperative recording system and a continuous recording system. However, the reason it is particularly suitable for the command system is that its working principle is: at least one driving signal is transmitted to an electrothermal conductive member, and the conductive member is placed on the ink holding plate or channel, and the driving signal can quickly cause the temperature to rise. A deviation of more than one nucleation boiling point, thereby providing thermal energy through the electrothermal conductor, produces film boiling at the heating site on the recording head, whereby each signal can form a bubble in the ink.

Through generation, development and contraction of the bubble, at least one drop of ink passes through the ejection port. Since the development and contraction of bubbles can be performed instantaneously, the ejection response of the ink is very fast. The driving signal is in the form of a pulse, which can be in accordance with the contents disclosed in US Patent Nos. 4,463,359 and 4,345,262. In addition, the temperature increase rate of the heating surface can refer to the technical content disclosed in US Patent No. 4,313,124.

The construction of the recording head may also be as disclosed in US Patent Nos. 4,558,333 and 4,459,600. Its heating part is arranged on a curved part, and the combination structure of the above-mentioned injection port, liquid channel and electric heat conductor of the present invention is also housed on this curved part. In addition, the present invention is also applicable to Japanese Laid-Open Patent Application No. 123670/1984, in which common slits are used as injection ports for a plurality of electric heat conductors. The present invention is also applicable to the structure disclosed in Japanese Laid-Open Patent Application No. 138461/1984, in which an opening for absorbing a heat energy pressure wave corresponds to an ejection portion. The reason for this is that the present invention can perform recording work efficiently and securely, regardless of the type of recording head.

The present invention can be effectively applied to recording heads of the so-called full-line type, which have a length corresponding to the maximum recording width, and which can include a single recording head and a plurality of records in large combinations, covering the maximum recording width. .

In addition, the present invention can also be applied to a series of recording heads of a type which is fixed to the main body, and a recording head of the type of replaceable circuit integrated block which is electrically connected to the main body, and is mounted on the main body. After reaching the main device, ink can be ejected; or a disk-type recording head with only a unit ink tank.

Recovery means and pre-operation auxiliary means are still adopted, because they can further stabilize the effect of the present invention. Specific means include encapsulation, cleaning, pressurization or absorption of the recording head, a preheater which may be an electrothermal conductor, an additional heater or a combination of the above. Also, the means for performing pre-ejection can stabilize the recording operation.

As for the variation of the mountable recording head, it may be a recording head corresponding to a single color of a unit, or may be individual recording heads corresponding to a plurality of inks having different colors or densities. The present invention is effectively applicable to such a recording head device having at least one monochrome type mainly black, a multi-color type with inks of different colors, or a full-color type using mixed colors, which can be It is a recording head that forms a whole, or a plurality of recording heads are combined.

In the foregoing embodiments, the inks are all liquids. However, solid inks that cure below room temperature and liquefy at room temperature are also possible. Since the ink is controlled between 30° C. and 70° C. in a general recording apparatus to ensure viscosity and ejection, a fully liquid ink within this range can be used. Other types of inks can also be used with the present invention. One is that when its temperature tends to rise due to heat conduction, the heat that raises its temperature is absorbed and diverted to change the solid ink into liquid ink. Additional ink is cured when not in use, preventing evaporation. In all of the above cases, the thermal energy generated by the recording signal is used to liquefy the ink so that it can be ejected. Another ink may be cured at the same time as it reaches the recording material. The present invention is also applicable to ink substances which are liquefied by heat and which are retained in liquid or solid form in holes or pores of a porous sheet as disclosed in Japanese Patent Application Laid-Open Nos. 56847/1979 and 71260/1985 . The sheet retaining solid or liquid ink faces the electrical heat conductor. The most effective heating method for inks mentioned above is the film boiling system.

The ink jet recording device can be used as a terminal device of an information processing device such as a computer or the like; a reproduction device incorporating a screen reader or the like; or a facsimile machine having a function of information selection and reception.

The original structure of the present invention has been fully described, but the present invention is not limited to the foregoing content. This patent application intends to protect the variants within the scope of the following claims and the variants within the improved purpose of the present invention.

Claims (12)

1. A liquid tank for containing a printing liquid to be supplied to a recording head for an inkjet recording apparatus, comprising: a first chamber containing a negative pressure generating material, having an air hole communicable with ambient air and a printing liquid supply port to allow the printing liquid to be supplied to the recording head; a second chamber, providing a printing liquid storage chamber for the first chamber, communicating with the first chamber through a communication port communicating with the first chamber, allowing printing liquid to flow into said first chamber, and allowing air to be drawn from said first chamber The first chamber leads into said second chamber, wherein said second chamber includes a replaceable printing fluid chamber. 2. A liquid tank for containing printing liquid to be supplied to a recording head for an inkjet recording apparatus, comprising: a first chamber containing a negative pressure generating material, and having an air hole communicating with ambient air and a supply port for supplying printing liquid to the recording head; and A second chamber communicates with the first chamber through a communication port to provide a printing liquid storage chamber for the first chamber, and a part of the second chamber can be separated from the rest to provide a replaceable printing liquid chamber. 3. A liquid tank according to claim 2, wherein said second chamber is provided with a detection means for detecting any liquid remaining in the second chamber. 4. The liquid tank according to claim 3, wherein said detection means is provided in a non-replaceable part of said second chamber. 5. The liquid tank according to claim 4, wherein said detecting means comprises an electrode. 6. The liquid tank according to claim 4, wherein said detection means includes a reflective member, and a part of said liquid tank is transparent. 7. The liquid tank according to claim 2, wherein said second cavity comprises a first additional cavity integrally formed with the first cavity, and a second additional cavity through which a coupling port of the first additional cavity can be releasably coupled to said first additional cavity, the coupling port protruding from said first additional cavity and configured as a closure part of a movable second additional cavity, when the second additional cavity is coupled to the first additional cavity While allowing printing liquid to flow from the second to the first additional cavity. 8. The liquid tank according to claim 1 or 2, wherein said liquid tank contains liquid for printing. 9. A component for forming a liquid tank for containing printing liquid to be supplied to a recording head for an inkjet recording apparatus, comprising a first chamber containing a negative pressure generating material, and having an air hole communicating with ambient air and a supply port for supplying printing liquid to the recording head; and an additional cavity, which is smaller than the first cavity and communicates with the first cavity through a communication port, the additional cavity is coupled with another additional cavity to form a printing liquid storage room for the first cavity, the coupling port of the additional cavity protrudes from the additional cavity, A closed portion configured to move the other additional chamber allows printing liquid to flow from the other additional chamber to the additional chamber when the other additional chamber is coupled to the additional chamber. 10. A replaceable printing liquid chamber containing printing liquid and having a printing liquid outlet closed by a closure member, and adapted to be coupled to the liquid tank described in any one of claims 1-9, when the chamber is coupled Into the liquid tank, the closure member is displaced to allow printing liquid to flow from the replaceable chamber to the liquid tank. 11. A recording head assembly for an inkjet recording apparatus, comprising the liquid tank according to any one of claims 1-7, and a recording head connectable to the supply port of the first chamber, so that the printing liquid can be supplied to the record header. 12. An ink jet recording apparatus comprising a recording head assembly according to claim 11, and means for mounting the recording head assembly to said apparatus for recording on a recording medium.

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