JPH045053A - Ink jet printer - Google Patents

Abstract

PURPOSE:To perform always stabilized purging irrespective of much or little of a residual quantity of ink by a method wherein an ink bag is pushed by a pushing lever means, and a driving means is controlled by detecting the ink residual quantity of ink in the ink bag. CONSTITUTION:When a purging command is given, a motor 13 is rotated, and a cam is counterclockwise rotated. A first lever 16 enters an acting operating position, swings clockwise, and a second lever 12 swings clockwise via a spring component 19. A pushing part 12a pushes a presser plate 4a, pressurizes ink in an ink bag 4, and the ink is made to flow out from a nozzle 1a of a printing head 1. As the ink in the ink bag 4 is being decreased, a reflecting board 22 descends, a light receiving element gradually approaches a position near a floodlight element, and a small residual detection value is obtained with an ink residue detection circuit. A number of many rotations of the cam is determined with an operation circuit based on the residual detection value, and the cam is rotated. The ink is pushed, and purging is performed.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention applies pressure to an ink bag that supplies ink to a print head, and flows out dust and air bubbles in an ink flow path together with ink from a nozzle. - This invention relates to an inkjet printer that performs zinc printing.

[Prior Art] Conventionally, when purging a print head, the ink bag is pressed directly with a fingertip or with a thin rod-shaped object, such as a pressure needle (Japanese Patent Laid-Open No. 63-274555). I was doing it.

[Problems to be solved] With these conventional methods, the pressing time and force must be constant, or too much ink may be produced, resulting in wasted ink.
If not enough, air bubbles and dirt may not be completely flushed out, or if the force is too strong, the ink bag or print head may be damaged. Further, even if the ink bag can be pushed with a uniform force, the internal pressure inside the ink bag varies depending on the amount of remaining ink, which may cause fluctuations in the amount and pressure of ink sent to the print head.

Therefore, an object of the present invention is to make it possible to always send a constant amount of ink to the print head during purging, regardless of the amount of ink remaining in the ink bag, and to perform stable purging, thereby ensuring that air bubbles and dirt are removed. The objective is to perform the removal and to enable initial ink filling. Furthermore, the purpose is to prevent damage to the print head or ink bag.

[Means for Solving the Problems] In order to achieve the above object, an inkjet printer of the present invention includes an ink case housing an ink bag connected to a print head mounted on a carriage, and an ink bag. It has a presser plate that is placed on top of the ink bag and moves according to the deformation of the ink bag, and a pressing part that can press the presser plate and is supported in a swingable manner. A pressing lever means that presses the ink bag via the presser plate by a pressing part when swinging, a driving means that swings the pressing lever means during purging, and detecting the amount of ink remaining in the ink bag. The apparatus includes a detection means and a control circuit that controls the drive means based on a value detected by the detection means.

The above-mentioned remaining ink amount detection means consists of a light emitting/receiving element provided on the carriage and a reflecting plate disposed to follow the deformation of the ink bag and facing the light emitting/receiving element. The remaining amount of ink may be detected based on the distance between the element and the reflecting plate. This reflecting plate may be provided on the holding plate.

The above-mentioned driving means may be composed of a cam rotationally driven by a motor, and in this case, a cam rotation detection switch is provided which can be turned on and off by swinging the pressing lever means, and the control circuit is configured to control the remaining ink. The rotational speed of the cam is determined based on the remaining amount detection value supplied from the amount detection means, and the cam is controlled by comparing it with the rotation detection value supplied from the rotation detection switch.

The driving means described above may be constituted by a stepping motor, and in this case, the control circuit is configured to control the driving pulses of the stepping motor based on the remaining amount detection value supplied from the remaining ink amount detecting means.

[Example code] Embodiments of the present invention will be described below based on the drawings.

1 to 4 show a first embodiment, in which a print head 1
The head is attached to the carriage 3 while being fixed by the block 2. An ink case 5 containing an ink bag 4 is detachably mounted on the carriage 3. In order to connect the print head 1 and the ink bag 4, a connecting body 6 or head mounting is provided in the block 2, and the ink supply needle 7 provided in the print head 1 is connected to the ink bag through this connecting body 6. 4 and supplies the ink inside to the nozzle 1a of the print head 1. The carriage 3 is guided by a guide shaft 8 and is conveyed in the left-right direction in FIG. The position of the carriage 3 in FIG. 1 indicates the home position of the print head 1, and at this position the nozzle 1a is capped by the camp 9 and purging is performed.

As shown in FIGS. 2 to 4, a window hole 5a is formed in the upper part of the ink case 5, and a presser plate 4a is provided on the upper surface of the ink bag 4 in the ink case 5, facing the window hole 5a.
is listed.

An ink pressing means 10 consisting of a pressing lever means 10A and a driving means 10B for swinging the pressing lever means 10A is provided on the mounting plate 11 provided at the home position. That is, a first lever 16 is rotatably supported on a shaft 15, and a second lever 12 is coaxially supported rotatably on the shaft 15, and a pressing portion 12a provided at the tip of the second lever 12 is Enter through the window hole 5a of the ink case 5 and press the presser plate 4a.
can be pressed. A spring member 19 is hooked between the first lever 16 and the second lever 12, which is a biasing member that biases the pressing portion 12a in a direction to press the holding plate 4a. A cam 14 is provided as the driving means 10B.

The cam 14 is rotated counterclockwise by the rotation of the motor 13, which is a drive source, via a transmission wheel train (not shown). A roller 17 that follows the cam 14 is provided at the tip of the first lever 16, and a protrusion 16b that presses a rotation detection switch Swl, which will be described later, is provided at the other end. A tension spring 18 is hooked to the lever 16, and the stop position is regulated by a positioning pin 16a. The lever 12 has a regulating protrusion 1 that can be engaged with the lever 16.
2C is provided upright, and this also serves as a spring hook for the spring member 19.

With such a structure, the pressing lever means 10A can be placed in the first position (shown in the second figure) where it is not in contact with either the pressing part 12a or the holding plate 4a, and in the first position (shown in the second figure) where the pressing part 12a is biased by the spring member 19 and the pressing part 12a is in the ink bag 4. and a second position (shown in the third figure) in which it abuts.

The first lever 16 is located between a rest position (shown in the second figure) where it engages with the degree setting pin 16a and an operating position (shown in the third figure) where it slides on the cam surface of the cam 14 and swings. It can be swung.

On the carriage 3, there is provided ink remaining amount detection means 20 for detecting the amount of ink remaining in the ink bag 4. That is, the carriage 3 is provided with a light emitting/receiving element 21 in which one light emitting element and a plurality of light receiving elements are aligned. A holding plate 4a provided on the top surface of the ink bag 4 is displaced following the deformation of the ink bag 4. A part of this holding plate protrudes from the ink case 5, and is located at a position facing the light emitting/receiving element 21. A reflecting plate 22 is provided at the top. The remaining ink amount detection means 20 is composed of a light emitting/receiving element 21 and a reflecting plate 22,
The remaining amount detection value changes in response to a change in the distance between the light emitting/receiving element 21 and the reflecting plate 22. That is, the light emitted from the light projecting element is reflected by the reflecting plate 22 and enters the light receiving element.

At this time, the remaining amount detection value is determined depending on which light receiving element receives the light. In this embodiment, the remaining amount detection value increases as the light-receiving element is farther from the light-emitting element.

The block diagram shown in FIG. 5 shows the control circuit 23 of this first embodiment, and when a purging command is given from the purging switch Sw, a driving signal is supplied from the driving circuit 24 to the ink pressing means lO, Purging is performed. On the other hand, in response to the output of the remaining ink amount detection means 20, the remaining amount detection value is supplied from the ink remaining amount detection circuit 25 to the arithmetic circuit 26, and the cam 14 is
The number of revolutions is determined. Further, during purging, a signal supplied from the rotation detection switch S w I every rotation of the cam is counted by the counter 27 to obtain a rotation detection value. This rotation detection value is sent to the comparator circuit 28 and the arithmetic circuit 2
6, and when the two match, the drive of the cam is controlled.

Purging is performed by turning on the purging switch Sw when the user determines that there is an abnormality in the printing condition, such as missing dots, or when replacing the ink case or turning on the power. It is. In either case, print head 1
is in the home position, the first lever 16 is in rest position contacting the regulating protrusion 12C, and the second lever 12 is in the rest position.
It is integrated with. When performing purging, when a purging command is given, a drive signal is supplied from the drive circuit 24 to the motor 13, the motor rotates, and the cam 14 rotates counterclockwise. The roller 17 follows the cam surface of the cam 14 from the position shown in the second figure, and moves the first lever 1
6 enters the operating position, moves away from the regulating protrusion 12c, and swings clockwise against the spring force of the tension spring 18. This swinging of the first lever 16 causes the second lever 2 to swing clockwise via the spring member 19 as shown in FIG. Lever 12
The pressing portion 12a contacts and presses the holding plate 4a, pressurizes the ink in the ink bag 4, and causes the ink to flow out from the nozzle 1a of the print head 1. The pressing force for pressing the pressing part 12a or the pressing plate 4a is generated by the spring member 19.
It is determined by the balance between the spring force and the repulsive force from the ink in the ink bag 4. In addition, the presser plate 4a allows
The entire upper surface of the ink bag 4 is pressed almost evenly.

If there is enough ink in the ink bag 4, the third
As shown in the figure, the presser plate 4a is only slightly lowered and the distance between the light emitting/receiving element 21 and the reflecting plate 22 is large. Since the light is reflected by the plate 22, it is received by a light receiving element located far from the light projecting element, and the remaining ink amount detection circuit 25 obtains a large remaining amount detection value. Based on this remaining amount detection value, it is detected that there is a large amount of ink remaining, and the rotation speed of the cam 14 is determined by the arithmetic circuit 26.
In this case, the rotation speed is set to a low number.

When the cam 14 rotates once after passing through the state shown in the third figure, the roller 17 falls from the cam 14, the pressing part 12a stops pressing the ink bag 4, and the first lever 16 is moved by the spring force of the tension spring 18. It returns to the position shown in the second figure. At this time, the rotation detection switch Swl is closed by the protrusion 16b, and it is detected that the cam 14 has rotated once. The number of times this switch is closed is counted by a counter 27,
This count number and the number of rotations of the cam determined by the arithmetic circuit 26 are compared by the comparator circuit 28, and when they match, a stop signal is supplied to the drive circuit 24. This ends purging.

That is, when there is sufficient ink in the ink bag 4, the internal pressure is large and the ink is sent out to the nozzle with this large pressure, so that a predetermined amount of ink can be flowed out from the nozzle 1a by increasing the number of revolutions of the cam.

As the amount of ink in the ink bag 4 gradually decreases, the reflecting plate 22 gradually descends, so that the light receiving element that receives the light becomes one that is located gradually closer to the light emitting element, and the remaining ink amount detection circuit 25 detects the light. A gradually smaller remaining amount detection value is obtained. Based on this remaining amount detection value, the arithmetic circuit 26 determines the number of revolutions of the cam which is gradually increased, and the cam is rotated by the number of revolutions to press ink and perform purging.

As shown in FIG. 4, when there is little ink left in the ink bag 4, the reflection plate 22 comes very close to the light emitting/receiving element 21, so that the light is not received by the light receiving element located closest to the light emitting element. , the minimum remaining amount detection value is obtained by the ink remaining amount detection circuit 25. The maximum number of rotations of the cam is determined by the arithmetic circuit 26 based on this remaining amount detection value, purging is performed at this maximum number of rotations, and purging ends when it matches the value of the counter 27 in the same manner as above. do. When the amount of ink remaining is low, the ink internal pressure is low, so the ink is sent to the nozzle with low pressure. Therefore, by rotating the cam many times and pressing the ink bag 4, a predetermined amount of ink can be sent to the print head.

Note that if the ink end lamp 29 is turned on when the remaining ink amount detection value of the ink remaining amount detection circuit 25 becomes smaller than a predetermined value, it is possible to visually check whether the ink is running out.

6 to 8 show a second embodiment, in which the driving means 30B, which is the ink pressing means 30, is driven by a stepping motor 33.
The pressing lever means 30A is rotatably supported coaxially with the sector gear 34 meshing with the motor gear 33a so as to be rotationally driven by the stepping motor 33, and the ink bag is rotated by the pressing lever means 30A. 4, and a spring member 35 hooked between the sector gear 34 and the press lever 32. 32c is a regulating protrusion. Other parts that are substantially the same as those in the first embodiment are given the same reference numerals.

The block diagram shown in FIG. 9 shows the control circuit 36 of this second embodiment, and based on the remaining amount detection value supplied from the remaining ink amount detection means 20 and the remaining ink amount detection circuit 25,
The drive pulse calculation circuit 37 supplies a drive pulse corresponding to the detected value of the remaining amount of the lever to the drive circuit. The rotation angle of the stepping motor 33 is controlled by this drive pulse.

To explain the operation, as shown in FIG. 6, the sector gear 34 is in a rest position in contact with the regulating protrusion 32c, and is integrated with the pressing lever 32. When performing purging, when a purging command is given, a drive signal is supplied from the drive circuit 24 to the stepping motor 33, causing the motor to rotate. The sector gear 34 rotates clockwise in accordance with the counterclockwise rotation of the motor gear 33a, enters the operating position, and separates from the regulating protrusion 32c. As shown in FIG. It oscillates clockwise in conjunction. Then, the spring force of the spring member 35 acts on the pressing lever 32, and the pressing portion 32a contacts and presses the presser plate 4a, pressurizing the ink in the ink hack 4 and causing it to flow from the nozzle 1a of the print head 1. Let the ink flow out.

If there is enough ink in the ink bag 4, the seventh
As shown in the figure, since the presser plate 4a is only held and lowered, a large remaining amount detection value is obtained as in the first embodiment. The number of drive pulses is calculated by the drive pulse calculation circuit 37 based on this remaining amount detection value, a small number of pulses is obtained, and the number of rotations of the stepping motor 33 is thereby controlled and purging is completed.

As the ink in the ink bag 4 gradually decreases, the reflecting plate 22 gradually descends, so that the ink remaining amount detection circuit 25 obtains a gradually smaller remaining amount detection value in the same manner as described above. Based on this remaining amount detection value, the drive pulse calculation circuit 37 gradually calculates a larger number of drive pulses and performs purging.

In this way, as shown in FIG. 8, when there is little ink remaining in the ink bag 4, the minimum remaining amount detection value is obtained by the ink remaining amount detection circuit 25. Based on this remaining amount detection value, the drive pulse calculation circuit 37 calculates the maximum number of drive pulses and performs purging.

In this way, as the amount of remaining ink decreases, the rotation angle of the stepping motor 33 increases, the swinging displacement of the pressing lever 32 increases, and the ink bag 4 is pressed more strongly. Similarly, a sufficient amount of ink can be delivered to the print head.

FIG. 10 shows a third embodiment, in which a driving means 40B using a stepping motor 43 similar to that of the second embodiment, and one pressing lever 42 having a pressing portion 42a similar to that of the second embodiment. The ink pressing means 40 is constituted by the pressing lever means 40A and the pressing lever means 40A. The control circuit in this embodiment is similar to that shown in FIG. In this example, the rotation of the stepping motor 43 directly swings the pressing lever 42 to press the ink bag 4, and the number of drive pulses supplied to the stepping motor 43 is controlled by the control circuit 36 as described in Section 2. Since the ink bag 4 is strictly controlled, there is no need to push the ink bag 4 too much.

Note that the ink remaining amount detection means is not limited to the one that determines the remaining amount detection value using a plurality of light receiving elements lined up and receiving light as described above, but may also be determined based on the amount of reflected light, or may be determined using a magnetic It may also be something that is detected.

Further, the remaining ink amount detecting means may not be provided on the carriage, but may be fixedly provided on the frame of the printer using a lever or the like.

[Effects] As described above, the inkjet printer of the present invention presses the ink bar using the pressing lever means.
Operation becomes stable.

During purging, the drive means is controlled by detecting the amount of ink remaining in the ink bag, so regardless of the amount of ink remaining, stable purging is always possible, and air bubbles and dirt are reliably removed. It can be removed and initial ink filling can be performed without causing damage to the print head or ink bag.

In addition, the driving means is a cam rotationally driven by a motor,
By turning the rotation detection switch on and off using the swinging of the pressing lever means, the number of rotations of the cam can be easily controlled with a simple configuration.

In addition, by using a stepping motor as the drive means and controlling the drive pulse of the motor based on the detected value of the remaining amount of ink, it is possible to easily adjust the pressing force applied to the ink bag with a simple configuration. Become something.

[Brief explanation of the drawing]

1 to 5 show a first embodiment of the present invention, FIG. 1 is a partially cutaway plan view, and FIGS. 2 to 4 are partially cutaway front views illustrating each stage of ink pressing. , FIG. 5 is a block diagram explaining the control circuit, and FIGS. 6 to 9 show the second embodiment.
Figure 8 is a partially cutaway front view explaining each stage of ink pressing;
FIG. 9 is a block diagram illustrating the control circuit, and FIG. 10 is a partially cutaway front view showing the third embodiment. DESCRIPTION OF SYMBOLS 1... Print head, 3... Carriage, 4... Ink bag, 4a... Holding plate, 5... Ink case, 10A, 30A, 40A... Pressing lever means, 10B
, 30B, 40B...driving means, 12a 32'a
, 42a...Press portion, 14...Drive means (cam), 20...Remaining ink amount detection means, 21...Light emitting/receiving element, 22...Reflection plate, 23.36...Control Circuit, 33.43...Driving means (stesoping motor SWI...
Rotation detection switch. (original), top

Claims (5)

[Claims] (1) An ink case housing an ink bag connected to a print head mounted on a carriage, and a presser foot that is placed on the ink bag and moves according to the deformation of the ink bag. It has a plate and a pressing part capable of pressing the presser plate, and is supported so as to be able to swing freely. At normal times, the pressing part is in a non-contact state with the presser plate, and when swinging, the pressing part pushes the presser plate. a pressing lever means for pressing the ink bag through a plate; a driving means for swinging the pressing lever means during purging; a detecting means for detecting the amount of ink remaining in the ink bag; and a detection value by the detecting means. An inkjet printer comprising: a control circuit that controls the driving means based on the following. (2) The remaining ink amount detection means includes a light emitting/receiving element provided on the carriage, and a reflecting plate disposed so as to be displaced in accordance with the deformation of the ink bag and facing the light emitting/receiving element. 2. The inkjet printer according to claim 1, wherein the remaining amount of ink is detected based on the distance between the light emitting/receiving element and the reflecting plate. (3) The inkjet printer according to claim 2, wherein the reflective plate is provided on the presser plate. (4) The driving means is a cam rotationally driven by a motor, and a rotation detection switch for the cam is provided which can be turned on and off by swinging the pressing lever means, and the control circuit is configured to control the residual ink. The number of rotations of the cam is determined based on the remaining amount detection value supplied from the amount detection means, and the cam is controlled by comparing it with the rotation detection value supplied from the rotation detection switch. The inkjet printer according to claim 1. (5) The drive means is a stepping motor, and the control circuit controls drive pulses of the stepping motor based on the remaining amount detection value supplied from the remaining ink amount detection means. Claim 1
The inkjet printer described in.