JP2006088648A - Ink jet recording head and ink jet recording apparatus - Google Patents

Abstract

To realize further downsizing and cost reduction of an ink jet recording head.
An ink supply port includes a discharge port, a substrate provided with a heater corresponding to the discharge port, and an ink supply port that penetrates the substrate. The ink supply port includes a pair of parallel sides having different lengths. And a second discharge port array 23 composed of a plurality of discharge ports 13 arranged along the short side and a second discharge port array 23 composed of the plurality of discharge ports 13 arranged along the long side. The first ejection port array along which the axis of the first ejection port array 20 along the short side of one ink supply port 15 adjacent in the arrangement direction is formed along the short side of the other ink supply port 15 20 is consistent.
[Selection] Figure 4

Description

  The present invention relates to an ink jet recording head that ejects liquid droplets by applying energy to a liquid, and an ink jet recording apparatus including such a recording head.

  As an example of the ink jet recording head, there is an ink jet recording head that obtains a driving force for ejecting droplets by applying thermal energy to a liquid. A conventional example of such an ink jet recording head will be described with reference to FIGS. FIG. 10 is an external perspective view of a conventional inkjet recording head unit 201. 11 is a schematic cross-sectional view of the main part of the ink jet recording head 207 mounted on the ink jet recording head unit 201 shown in FIG. 10, FIG. 12 is a plan view, and FIG. 13 is a partially enlarged plan view. is there.

  10 includes a support member 202, a plate 203 provided on the upper surface of the support member 202, a connector 204 provided on a side surface of the support member 202, and one end side joined to the plate 203. A flexible circuit board 205 having the other end bonded to the connector 204, and an ink jet recording head 207 respectively disposed inside three rectangular holes provided on one end of the flexible circuit board 205 bonded to the plate 203. Have.

  As shown in FIG. 11, in each ink jet recording head 207, a channel 212 and a discharge port 213 are formed on a silicon substrate 210 by a channel forming member 211, and a heater 214 is disposed in the channel 212. The liquid (ink) is supplied into the flow path 212 from the back side of the silicon substrate 210 through the ink supply port 215 that penetrates the silicon substrate 210. When a voltage is applied to the heater 214 to heat and foam the ink in the flow path 212, a droplet (ink droplet) is ejected from the ejection port 213. Application of voltage to the heater 214 is performed by a transistor circuit (not shown) provided on the silicon substrate 210. Specifically, an electric signal input to the connector 214 shown in FIG. 10 is input to the transistor circuit via an electric circuit board (not shown) and the flexible circuit board 205. The transistor circuit operates according to the input electric signal, and turns on / off the voltage application to the heater 214.

As a method of forming the flow paths and the discharge ports with high density in the ink jet recording head having the basic structure as described above, methods described in Patent Document 1 and Patent Document 2 have been proposed. As for the formation of the ink supply port, a method of making a hole in a silicon substrate by anisotropic etching is known. Further, as a method for elongating the ink jet recording head, a method of forming a plurality of ink supply ports along the longitudinal direction of the substrate is known, and the ink jet recording head 207 shown in FIGS. The method is adopted.
JP-A-5-330066 JP-A-6-286149

  As shown in FIG. 12, in the ink jet recording head 207 mounted on the conventional ink jet recording head unit 201, the rectangular ink supply port 215 is in the sub-scanning direction of the ink jet recording head unit 201 (the arrow Y direction in the figure). A plurality of ejection ports 213 are arranged in a line along the long side of each ink supply port 215. Here, in order to prevent the printing omission from occurring when printing while scanning the ink jet recording head unit 201 in the main scanning direction (arrow X direction in the figure), the ejection port 213 is made constant in the sub scanning direction. It is necessary to arrange at a pitch. Therefore, as shown in FIG. 13, the longitudinal direction ends of the plurality of ink supply ports 215 arranged in a staggered manner overlap each other by d (mm) in the main scanning direction. Therefore, it is necessary to provide a beam portion having a predetermined dimension Wh (mm) between the ink supply ports 215 adjacent in the main scanning direction to maintain the mechanical strength of the silicon substrate 210, and the width Wc (mm of the silicon substrate). ) Became wide. The wide width of the silicon substrate 210 not only hinders the miniaturization of the ink jet recording head 207, but also causes a reduction in the number of substrates taken from the wafer, leading to an increase in the cost of the ink jet recording head 207.

  An object of the present invention is to realize an ink jet recording head that is further reduced in size and cost while maintaining at least the same recording density and durability as in the past.

  The inkjet recording head of the present invention includes a plurality of ejection ports for ejecting ink, a substrate provided in correspondence with the ejection ports and provided with a plurality of energy generation elements, and supplies ink to the plurality of energy generation elements. In order to do this, an ink jet recording head comprising a plurality of ink supply ports formed through the substrate, the plurality of ink supply ports have a set of parallel sides of different lengths, and A first discharge port array in which the plurality of discharge ports are arranged in a row along the short side of the set of sides, and a plurality of discharge ports is 1 along the long side of the set of sides. A plurality of ink supply ports arranged in a zigzag state such that the long side and the short side alternate in the longitudinal direction. , One ink supply adjacent in the array direction The axis of the first ejection port array provided along the short side of the first ink ejection port coincides with the first ejection port array provided along the short side of the other ink supply port, or the first ejection port. It passes between the second ejection port row provided along the long side of the second ink supply port and the second ink supply port.

  According to the above-described configuration, the width Wc of the silicon substrate can be reduced by reducing the width of Wh shown in FIG. 13 while maintaining the strength, so that at least the recording density and durability equivalent to those of the prior art can be maintained and the inkjet can be performed. Further downsizing and cost reduction of the recording head can be realized.

(Embodiment 1)
Hereinafter, an example of an ink jet recording head unit provided with the ink jet recording head of the present invention will be described in detail with reference to FIGS. FIG. 1 is an external perspective view of the ink jet recording head unit 1 of this example, and FIG. 2 is an enlarged cross-sectional view of the main part. 3 is a partial cross-sectional view of the ink jet recording head 7 mounted on the ink jet recording head unit 1 of this example, FIG. 4 is a plan view, and FIG. 5 is a partial enlarged plan view. Moreover, FIG. 6 is explanatory drawing which shows typically the printing dot by the inkjet recording head unit 1 of this example.

  As shown in FIGS. 1 and 2, the ink jet recording head unit 1 of this example includes a support member 2, a plate 3 joined to the upper surface of the support member 2, and a connector 4 joined to the side surface of the support member 2. The flexible circuit board 5 having one end joined to the upper surface of the plate 3 and the other end joined to the end of the connector 4, and the three provided on one end of the flexible circuit board 5 joined to the upper surface of the plate 3 And an inkjet recording head 7 disposed inside the rectangular hole 6. In the inkjet recording head 7 shown in FIG. 2, the upper layer portion from the ink supply port 15 is omitted for convenience.

  As shown in FIG. 3, each inkjet recording head 7 has a flow path forming member 11 on a silicon substrate 10, and a large number of flow paths 12 and ejection ports 13 communicating with the flow paths 12 are formed. A heater 14 is provided in the path 12. The liquid (ink) is supplied into the flow path 12 from the back side of the silicon substrate 10 through the substantially trapezoidal ink supply port 15 penetrating the silicon substrate 10 and is heated by the heater 14 to be discharged as ink droplets. Discharge from the outlet 13.

  The ink jet recording head 7 will be described in more detail. As shown in FIG. 4, the ink jet recording head 7 has two supply ports in which a plurality of substantially trapezoidal ink supply ports 15 are arranged at regular intervals along the longitudinal direction. Rows 21 and 22 are provided parallel to each other. Here, the ink supply port 13 constituting one supply port row 21 or 22 and the ink supply port 13 constituting the other supply port row 22 or 21 have one pitch (supply port 1) in the arrangement direction. Are present in a staggered manner.

  On the upper bottom side of each ink supply port 15, a plurality of ejection ports 13 are provided in a row at a constant pitch along the upper bottom. Further, the ejection ports 13 provided on the upper bottom side of each ink supply port 15 are arranged on a common straight line parallel to the long side of the inkjet recording head 7 to form a first ejection port array 20. . In other words, a first ejection port array 20 in which a plurality of ejection ports 13 are arranged in a line at a constant pitch along the longitudinal direction of the inkjet recording head 7 is approximately at the center in the width direction of the inkjet recording head 7. A plurality of ink supply ports 15 are arranged in a staggered manner so that the upper base and the first discharge port array 20 face each other across the first discharge port array 20.

  Further, on the lower bottom side of each ink supply port 15, a second ejection port array 23 is provided in which a plurality of ejection ports 13 are arranged in a line at a constant pitch along the lower bottom. That is, there is one first ejection port array 20, but there are as many second ejection port arrays 23 as the number of ink supply ports 15. Then, as shown in FIG. 5, the ejection port 13 a at the end in the arrangement direction of the second ejection port array 23 formed on the lower bottom side of each ink supply port 15, and the ink supply port closest to the ink supply port 15 15 overlaps with the discharge port 13b at the beginning of the arrangement direction of the second discharge port array 23 provided on the lower bottom side of the ink jet recording head 7 in the main scanning direction (arrow X direction in FIG. 5). . That is, the discharge port 13 a at the end in the arrangement direction and the discharge port 13 b at the start end exist on a straight line orthogonal to the first discharge port array 20. However, depending on the ratio of the length of the upper base and the lower base of the ink supply port 15, not only the discharge ports 13 a and 13 b at the end in the arrangement direction and the start end, but also two or more discharge ports at the end in the arrangement direction including them. Can be overlapped as described above.

  Here, at the time of printing, the inkjet recording head 7 is reciprocated in the direction of arrow X in FIG. 5, so the recording density in the sub-scanning direction (arrow Y direction) is determined by the pitch of the ejection ports 13 in the same direction. Is done. In this example, the pitch of the ejection ports 13 in the sub-scanning direction is all constant, and P1 and P2 shown in FIG. 5 are both 42.3 μm (= 600 dpi).

  Referring to FIG. 2 again, the support member 2 and the plate 3 on which the ink jet recording head 7 having the above structure is mounted are provided with a common liquid chamber 30 communicating with each ink supply port 15 of each ink jet recording head 7. Yes. The common liquid chamber 30 has a structure in which ink is supplied from an ink inlet (not shown), and the ink supplied to the common liquid chamber 30 flows from the ink supply port 15 of each inkjet recording head 7 to the flow path. 12 is heated by the heat of the heater 14. The voltage is applied to the heater 14 by a transistor circuit (not shown) provided on the silicon substrate 10 (FIG. 3). Specifically, the electric signal input to each contact terminal 31 of the connector 4 shown in FIG. 1 is input to the transistor circuit via an electric circuit board (not shown) and the flexible circuit board 5. The transistor circuit operates in accordance with the input electric signal, and turns on / off the voltage application to the heater 14.

  2 can be supplied with different color inks such as yellow, magenta, and cyan, or can be supplied with the same color ink. Therefore, the inkjet recording head 1 of this example can perform printing of up to three colors.

  FIG. 6 schematically shows print dots printed using the ink jet recording head unit 1 of this example. 6 includes a plurality of ejection ports belonging to the second ejection port array 23 provided on the lower bottom side of the left ink supply port 15 among the three ink supply ports 15 illustrated in FIG. 13 (hereinafter referred to as “discharge port group 51a”) and a plurality of discharge ports 13 (hereinafter referred to as “discharge ports”) provided on the upper bottom side of the ink supply port 15 among the discharge ports 13 belonging to the first discharge port array 20. This is due to the ink droplets ejected from the outlet group 51b "). Also, the print dots 42 shown in FIG. 6 are formed by a plurality of discharge ports 13 (hereinafter referred to as “discharge port group 52a” belonging to the second discharge port array 23 provided on the lower bottom side of the central ink supply port 15 in FIG. ”) And a plurality of ejection ports 13 (hereinafter referred to as“ ejection port group 52b ”) provided on the upper bottom side of the ink supply port 15 among the ejection ports 13 belonging to the first ejection port array 20. This is due to ink drops. Further, the print dots 43 shown in FIG. 6 are a plurality of discharge ports 13 (hereinafter referred to as “discharge port group 53a”) belonging to the second discharge port array 23 provided on the lower bottom side of the right ink supply port 15 in FIG. ”) And a plurality of ejection ports 13 (hereinafter referred to as“ ejection port group 53b ”) provided on the upper bottom side of the ink supply port 15 among the ejection ports 13 belonging to the first ejection port array 20. This is due to ink drops.

  As can be seen from FIG. 6, at the boundary between the print dots 41 and 42, discharge is performed from the discharge port 13a positioned at the right end of the discharge port group 51a and the discharge port 13b positioned at the left end of the discharge port group 52b shown in FIG. Ink droplets land alternately in the main scanning direction. On the other hand, at the boundary between the print dots 42 and 43, the ink droplets ejected from the ejection port 13a located at the right end of the ejection port group 52b and the ejection port 13b located at the left end of the ejection port group 53a are alternately arranged in the main scanning direction. Has landed. That is, in the ink jet recording head 7 mounted on the ink jet recording head unit 1 of this example, the discharge ports 13 a and 13 b at the end of the second discharge port array 23 provided for each ink supply port 15 are mainly used. Since they overlap each other in the scanning direction, the ink droplets discharged from the pair of overlapping discharge ports 13a and 13b land alternately on the same straight line. As a result, even if there is some variation between the ink droplets ejected from one ejection port 13a or 13b and the ink droplets ejected from the other ejection port 13b or 13a, image degradation due to this variation. Disappears.

  Further, in each of the inkjet recording heads 7 mounted on the inkjet recording head unit 1 of this example, trapezoidal ink supply ports 15 are staggered so that the upper bottom faces inward in the width direction of the inkjet recording head 7. Accordingly, a necessary and sufficient clearance W1 is ensured between the nearest ink supply ports 15, and the width W2 of the ink jet recording head 7 is reduced without reducing the mechanical strength of the ink jet recording head 7 (FIG. 5). . Further, since the plurality of ejection ports 13 provided on the upper bottom side of each ink supply port 15 are all arranged in a straight line to form the first ejection port array 20, both the ejection port arrays 20. The outer ink supply ports 15 are close to each other, and the width W2 of the inkjet recording head 7 is further narrowed. Here, if the ejection ports 13 provided on the upper bottom side of each ink supply port 15 are arranged on two or more straight lines, the ink droplets ejected from the ejection ports 13 in each row land on the recording medium. Although there is a possibility that a deviation occurs in the timing of the ink jet recording, there is no possibility that the ink jet recording head 7 of this example is affected.

(Embodiment 2)
Hereinafter, another example of an ink jet recording head unit equipped with the ink jet recording head of the present invention will be described in detail with reference to the drawings. The basic configuration of the ink jet recording head unit of this example is the same as that of the ink jet recording head unit of the first embodiment, and the difference is the configuration of the ink jet recording head. Therefore, overlapping description of common portions is omitted, and here, an ink jet recording head will be mainly described. FIG. 7 is a plan view of the ink jet recording head 107 mounted on the ink jet recording head unit 101 of this example, and FIG. 8 is a partially enlarged plan view. FIG. 9 is an enlarged cross-sectional view of the main part of the ink jet recording head unit 101 of this example.

  The basic structure of the ink jet recording head 107 mounted on the ink jet recording head unit 101 of this example is the same as that of the ink jet recording head 7 mounted on the ink jet recording head unit 1 of the first embodiment. That is, as shown in FIG. 7, a large number of flow paths (not shown) and discharge ports 113 communicating with the flow paths are formed on the silicon substrate 110 by the flow path forming member 111. A heater (not shown) is provided. The liquid (ink) is supplied into the flow path from the back surface side of the silicon substrate 110 through the trapezoidal ink supply port 115 through the silicon substrate 110 and heated by the heater to form ink droplets. And discharged from the discharge port 113. Therefore, the ink jet recording head 107 mounted on the ink jet recording head unit 101 of this example is different from the ink jet recording head 7 mounted on the ink jet recording head unit 1 of Embodiment 1 in that the ejection port 113 and the ink supply port are different. There are only 115 arrangements.

  The ink jet recording head 107 is provided with supply port arrays 121 and 122 in which a plurality of ink supply ports 115 are arranged in a staggered manner along the longitudinal direction thereof. Here, since the arrangement state and the like of the ink supply ports 115 in the supply port arrays 121 and 122 are the same, the arrangement state of the ink supply ports 115 will be described by taking the supply port array 121 as an example. As shown in FIG. 8, a plurality of ejection ports 113 are provided in a row in parallel with the upper and lower bases on the upper and lower bases of each ink supply port 115 constituting the supply port array 121. Thus, the first discharge port array 120 and the second discharge port array 123 are formed. In addition, the plurality of ink supply ports 115 constituting the supply port array 121 are arranged such that their upper and bottom sides overlap each other in the arrangement direction. As a result, the first ejection port array 120 provided on the upper bottom side of each ink supply port 115 is different from the first ejection port array 120 of the other ink supply ports 115 adjacent in the arrangement direction. It is located between the outlet row 123. In other words, the axis of the first ejection port array 120 provided on the upper bottom side of each ink supply port 115 is the same as that of the first ejection port array 120 of the other ink supply port 115 adjacent in the arrangement direction. Two discharge port rows 123 are vertically cut.

  As shown in FIG. 9, the ink jet recording head 107 having the above structure is mounted on a plate 103 joined to the upper surface of the support member 102. The support member 102 and the plate 103 have a common liquid chamber 130 a communicating with each ink supply port 115 constituting the supply port row 121 and a common liquid chamber communicating with each ink supply port 115 constituting the supply port row 122. 130b. The common liquid chambers 130a and 130b are configured to be supplied with ink from an ink inflow port (not shown). The ink supplied to the common liquid chambers 130a and 130b passes through the supply port arrays 121 and 122, respectively. It is supplied to the corresponding flow path through and heated by the heat of the heater. Although not shown in FIG. 9, the support member 102 is provided with a connector, an electric circuit board, and a flexible circuit board, and the voltage application to the heater is the same as described in the first embodiment. Is turned ON / OFF. Further, in the ink jet recording head 107 shown in FIG. 9, the upper layer portion from the ink supply port 15 is omitted for convenience.

  As described above, since the ink jet recording head mounted on the ink jet recording head unit of this example is provided with two supply port arrays, two colors can be printed with one head. Further, it is not necessary to adjust the registration between colors after the head is mounted on the support member. Further, since the ink supply ports constituting each supply port array are arranged so that the upper bottom side thereof partially overlaps in the width direction of the head, the lateral width is larger than that of the head described in the first embodiment. It is getting narrower. Therefore, the ink jet recording head of this example is a cheaper and more compact ink jet recording head. In this example, an example in which two supply port arrays are provided in one head 107 is shown, but it is also possible to realize printing of three or more colors by providing three or more supply port arrays.

  Both the ink jet recording head unit 101 of this example and the ink jet recording head unit 1 of Embodiment 1 can be mounted on a carriage provided in a recording apparatus main body provided with a conveying means for conveying recording paper. The carriage is reciprocated to the left and right by a carriage motor, and the mounted inkjet recording head unit is scanned in the same direction (main scanning direction). On the other hand, the transport unit transports the recording paper in a direction (sub-scanning direction) orthogonal to the moving direction of the carriage. Then, ink droplets are ejected from the inkjet recording head in accordance with an electrical signal output from the recording apparatus main body while the inkjet recording head unit is scanned in the main scanning direction, and printing on the recording paper is performed. The number of ink jet recording head units (ink jet recording heads) mounted on the recording apparatus is not limited to one, and there may be two or more. For example, two ink jet recording head units are installed, one head unit is assigned with ink of each color of yellow, magenta, and cyan, and the other head unit is supplied with ink of each color of black, light magenta, and light cyan. It can also be assigned.

2 is an external perspective view of the ink jet recording head unit shown in Embodiment 1. FIG. It is an expanded sectional view of the principal part of the inkjet recording head unit shown in FIG. FIG. 2 is a partial cross-sectional view of an ink jet recording head mounted on the ink jet recording head unit shown in FIG. 1. It is a top view of the inkjet recording head mounted in the inkjet recording head unit shown in FIG. FIG. 2 is a partially enlarged plan view of an ink jet recording head mounted on the ink jet recording head unit shown in FIG. 1. It is explanatory drawing which shows typically the printing dot by the inkjet recording head unit shown in FIG. 6 is a plan view of an ink jet recording head mounted on an ink jet recording head unit shown in Embodiment 2. FIG. FIG. 2 is a partially enlarged plan view of the ink jet recording head shown in FIG. 1. FIG. 6 is an enlarged cross-sectional view of a main part of an ink jet recording head unit shown in Embodiment 2. It is an external appearance perspective view of the conventional inkjet recording head unit. It is typical sectional drawing of the principal part of the inkjet recording head mounted in the inkjet recording head unit shown in FIG. It is a top view of the inkjet recording head mounted in the inkjet recording head unit shown in FIG. FIG. 11 is a partially enlarged plan view of an ink jet recording head mounted on the ink jet recording head unit shown in FIG. 10.

Explanation of symbols

1, 101, 201 Inkjet recording head unit 2, 102, 202 Support member 3, 103, 203 Plate 4, 204 Connector 5, 205 Flexible circuit board 7, 107, 207 Inkjet recording head 12 Flow path 13, 113, 213 Discharge port 14, 214 Heater 15, 115, 215 Ink supply port 20, 120 First discharge port array 21, 121 Supply port array 22, 122 Supply port array 23, 123 Second discharge port array

Claims (4)

A plurality of ejection openings for ejecting ink;
A substrate provided with a plurality of energy generating elements provided corresponding to the discharge ports;
A plurality of ink supply ports formed through the substrate to supply ink to the plurality of energy generating elements;
In an inkjet recording head comprising:
The plurality of ink supply ports have a set of parallel sides having different lengths, and a plurality of the discharge ports are arranged in a row along a short side of the set of sides. An outlet row, and a second ejection port row in which the plurality of ejection ports are arranged in one row along the long side of the set of sides,
The plurality of ink supply ports are arranged in a zigzag state so that the long side and the short side alternate in the longitudinal direction thereof,
The axis of the first ejection port array provided along the short side of one ink supply port adjacent in the arrangement direction is the same as the first ejection port array provided along the short side of the other ink supply port. An ink jet recording head characterized by passing between the first ejection port array and the second ejection port array provided along the long side of the other ink supply port.   2. The second ejection port array provided along the long side of each of the adjacent ink supply ports has a portion overlapping in a direction orthogonal to the second ejection port array. The inkjet recording head described.   The energy generating element is an electrothermal conversion element that converts electric energy into heat energy according to an electric signal input from the outside, and foams ink by the heat energy converted by the electrothermal conversion element, The ink jet recording head according to claim 1, wherein the ink jet recording head is ejected from the ejection port. An ink jet recording apparatus on which one or more ink jet recording heads according to claim 1 are mounted.

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