JPH01174459A - Ink jet recorder - Google Patents

Abstract

PURPOSE:To make a waste ink storage sump compact or to reduce the complexity in waste ink disposal, by a construction wherein the discharge recovery of a recording head by a predischarge is superimposed on a black pixel, if present. CONSTITUTION:An elapsed time after the last ink discharge is managed for every nozzle. When the elapsed time is beyond a set time, a discharge recovery processing is carried out by a predischarge. At this time, if black dots are recorded in one-line recording process, a discharge recovery processing in recording heads 102Y, 102M, and 102C for colors other than Black is superimposed on dots formed on a recording medium R with the black ink. In this manner, the amount of a waste ink stored in a waste ink tank 105 is decreased, the waste ink sump 105 can be made compact, or the complexity in waste ink disposal can be decreased. On the other hand, since the positioning to a recovery system 100 or the drive number thereof can be reduced, the throughput in recording can be enhanced.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an inkjet recording device that records on a recording medium using ink, and in particular, an inkjet recording device that is capable of recording in multiple colors including black on the recording medium. A material suitable for application to an inkjet recording device or the like is used.

[Prior Art] Inkjet recording apparatuses have many advantages, such as extremely low noise during recording and the ability to record on plain paper, and have been attracting more and more attention in recent years.

Among them, on-demand type inkjet recording devices use electromechanical transducers such as piezoelectric elements, magnetostrictive elements, or electrothermal transducers to eject ink during recording, and consume ink only when necessary for recording. Therefore, it has the great advantage that it does not require a means for collecting unnecessary ink or a high voltage power supply for changing the ink.

In such inkjet recording devices, the recording head is equipped with a large number of nozzles, and whether or not all the nozzles are used during recording depends on the shape and type of the image to be formed. In the case of inkjet recording apparatuses that carry out this process, there is also uncertainty depending on the color. Rather, there are many cases where one of the nozzles is not used.

By the way, one of the problems that needs to be solved with on-demand type inkjet recording devices is that if the nozzles are not used for a long time, that is, if the frequency of use of the nozzles is uneven, they tend to become clogged. Even if this does not occur, if the ink is suddenly used after a long period of non-use, the ink may increase in viscosity and may not be ejected normally, resulting in a decrease in printing quality.

Therefore, an ink collecting member is provided so as to be able to face the recording head, and a timer is started during printing, and when the non-printing state exceeds a set time, the head and ink collecting member are moved relative to each other to face each other. However, there is one in which all the nozzles are driven toward the ink collecting member to eject ink (preliminary ejection). In addition, there are some devices in which ink is sucked from the nozzle by a suction device provided on the ink collecting member side, and ink is discharged from the nozzle by a pressure device provided in the ink supply system.

In order to improve the recording quality, it is most desirable to use the nozzle all the time, so the above operation (
(hereinafter referred to as ejection recovery processing) needs to be performed frequently.

[Problems to be Solved by the Invention] However, although the amount of ink used at one time in the above-mentioned forced ejection or preliminary ejection in an inkjet recording device is small, it is desirable to perform it many times. The amount of ink used is enormous.

Therefore, the waste ink storage member that stores such ink (waste ink) becomes large, which causes the problem of increasing the size of the device.To avoid this, it is necessary to frequently dispose of the waste ink or waste ink storage member. There will be complications that have to be done.

Furthermore, since the ejection recovery process involves a process of performing preliminary ejection and forced ejection with the print head and ink collection member facing each other, the print operation is often interrupted, which tends to reduce the print throughput.

In addition, there is a problem in that as ink is consumed, the frequency of ink replenishment and ink cassette replacement increases.

The purpose of the present invention is to solve these problems, and to reduce the size of the waste ink storage member or the complexity of waste ink disposal, especially in an inkjet recording device that is capable of recording images including black on a recording medium. At the same time, the objective is to improve the recording throughput.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides an inkjet recording apparatus having a recording head that is compatible with a plurality of types of ink. a control means for ejecting another type of ink not related to pixel formation to a position superimposed on the pixel to be formed, and a processing means for controlling the control means for performing ejection recovery processing for ejecting ink from the recording head. It is characterized by having the following.

[Function] According to the present invention, the ejection recovery process for the ink ejection ports provided in the ink recording head that does not involve the formation of black pixels is performed when the black pixel is at a position where the pixel can be recorded by the ejection port. This is done by superimposing it on black pixels. That is, compared to, for example, performing the ejection recovery process with the ink collection member facing the ejection port, the amount of waste ink is reduced, so the waste ink storage member can be made smaller, and the waste ink storage member can be made smaller during the information recording operation. Since the ejection recovery process is performed, the recording throughput is also improved. Furthermore, since ink consumption can be suppressed, the frequency of ink replenishment and ink cassette replacement is also reduced.

[Example] .

Hereinafter, the present invention will be described in detail with reference to the drawings.

Here, 101A and 10IB move the recording medium R in the sub-scanning direction V according to the drive of a line feed motor (not shown).
A pair of upper and lower rollers are provided to nip and convey the recording material S and to regulate the recording surface. 102 is the carriage 10
It moves back and forth in the direction shown by arrow IIs in the figure (main scanning direction) in response to the drive of the carriage motor 108A, and sprays ink onto the recording medium R during the forward movement (rightward direction in the figure). This is an inkjet recording head that performs recording by ejecting ink. In this example, in order to enable multi-color recording, for example, as shown in the figure, black, black,
A recording head 1028 having yellow, magenta and cyan nozzle groups includes nozzles 102Y, 102M and 102Y.
2C are placed in this order toward the recording medium R from the right hand side.

As shown in FIG. 2, each recording head 102 has N nozzles 102' (for example, 128) arranged over a range corresponding to the width of one line, each having an opening on the surface facing the recording medium R. That's what happens.

106BK, 106Y, 106M and 101ic are removably mounted on the carriage 108, and 102Y, 102M and 102C are mounted on the recording head 1028, respectively.
107Y, 107M, and 107 in the supply tube 1078.
It communicates with each recording head via C.

110 is a carriage motor for moving the carriage 108 in the H5 direction, and drives the carriage 108 via a wire 112 stretched around a pulley 111. Further, 113 is a guide rail for guiding the carriage 108 in the HS direction, and holds the carriage 108 slidably.

103 is a head 102B at a position outside the recording range of the head 102, for example, a home position.

103Y, 103M are attached to cap members 1038 disposed opposite to 102Y, 102M and 102C, respectively.
and 103C, and when the printer is not in use, it moves in the direction C in the figure in accordance with the drive of an appropriate drive means, and is bonded to the head 102 to protect it. ~1θ3C of each cap member 1038 is communicated with the pump 104, and when each print head and each cap member are joined and the pump 104 is driven, ink is sucked from the print head side, and ejection recovery is performed by suction. You can do it like this. Discharge recovery due to this suction is
This can be performed when a cause of ejection failure occurs that is difficult to remove by ejection recovery using preliminary ejection, such as when dust or air bubbles are mixed into the ink supply system. The rough pump 104 can be used to suck ejected ink when preliminary ejection is performed with each recording head and each cap member facing each other in close proximity.

The waste ink sucked in these processes is guided to a waste ink storage member 105 provided at an appropriate location in the apparatus. This member 105 may be removably disposed on the carriage 108; in this case, the member 105
8 is at the home position, the pump 104 and the storage member 105 may be configured to communicate with each other.

In this example, the elapsed time after the last ink ejection is managed for each nozzle, and when the elapsed time exceeds the set time, ejection recovery processing is performed by preliminary ejection. When a black dot is recorded, the ejection recovery process in the recording head of a color other than black is performed to overlap the dot formed on the recording medium R by the black ink.

FIG. 3 shows an example of the configuration of a control system related to the apparatus shown in FIG. Here, 1 is a CP in the form of a microcomputer, for example.
4, and controls each part based on the processing procedure described later with reference to FIG. 3 is a ROM that stores fixed data such as programs corresponding to the processing procedures executed by the CPIII. 5 is a RAM, in which the image information sent from the host device H, which is the image data supply source, is developed for each color, for example, for one line, and the CPUI controls the drive of the recording radar 102 according to the contents of the development. do. A timer 7 is used to manage the non-use time of each nozzle of each recording head 102.

100 is a cap device 103 and a pump 1 in FIG.
This is a recovery system that includes 04 and their drive systems. lO
and 20 are carriage 1 in FIG.
Carriage motor 1 for moving 08 in H5 direction
10 and a line feed motor 120 for conveying the recording medium R in the vS direction. 1
28, 12Y, 12M and 12G are connected to the recording head 102B, respectively.
This is a drive circuit for driving the ejection energy generating elements arranged in the nozzle group No. C (No. 1 to No. N).

FIG. 4 shows an example of the recording processing procedure etc. in the above configuration, in which the carriage 108 is directed toward the B shift start position (home position or reverse position) during the recording operation at the end of recording a predetermined amount, for example, one line or multiple lines. When starting the return, it can be started together with a line feed process.

First, in step Sl, image information for one line is stored in the RAM 5 for each color in preparation for recording the next line, and is sent to each nozzle and H.
The timer 7 for each nozzle of each recording head 102 is expanded in step S3.
Check. In step S5, it is determined whether there is any device whose non-use time exceeds a predetermined value (timeout), and if the determination is negative, the process proceeds to step 517, and if the determination is affirmative, the process proceeds to step S7.

In step S7, the nozzle (for example, the recording head 102
Recording head 10 on the same line as Y nozzle No. 2)
2BK nozzle (for example, nozzle number for recording head B,
2) is driven, that is, whether black pixels are recorded. If the determination is affirmative here, drive information is set in the RAM 5 so that after recording the black pixel, the nozzle that has timed out is driven to the recording position to perform superimposed ejection in step S9. On the other hand, step S
If a negative determination is made in step 7, the process proceeds to step Sll, where the carriage 108 is set to the home position, the recording head 102 and the cap device 103 are brought close to face each other or joined together, and preliminary ejection is performed for the nozzles that have timed out in step 513. let Note that forced evacuation performed by driving the pump 104 may also be used in this process. After the processing in step S9 or step 513, the timer for that nozzle is reset in step 515.

After the processing in step 515 or if a negative determination is made in step S7, in step 517 the carriage 10
8 in the right direction in FIG.
The recording process is executed while driving the recording heads 102B to 102C via 2G. In this process, if there is a black pixel on the same line for the nozzle that has timed out, superimposed ejection is performed on that black pixel.

In this way, in this example, when the non-use time of a nozzle exceeds a predetermined value, ejection recovery related to the recovery system 100 is not performed uniformly, but when there is a black pixel on the same line, this Since ejection recovery is performed by ejecting in a superimposed manner, the amount of waste ink stored in the waste ink tank 105 is reduced, which reduces the size of the waste ink tank 105 and reduces the complexity of waste ink disposal. We were able to achieve a reduction.

Furthermore, the number of times the recovery system 100 is set and driven can be reduced, and the recording throughput is improved compared to the conventional system.

In this embodiment, when recording in the forward direction, the nozzles whose non-use time exceeds a predetermined value are driven, but the line feed of the recording medium R is stopped at the start of the 8-movement in the backward direction. It is also possible to disable this and set the contents of the RAM 5 so that superimposed ejection to black pixels is performed at the time of recovery.

In addition, although the upper side is assumed to perform recording only when moving in the forward direction, it may be a device that performs reciprocating recording.
In this case, for example, the above process could be performed by placing black recording heads 1026 on both the left and right sides of the carriage 108. In addition, efficient ejection recovery reduces ink consumption, which reduces the frequency of ink replenishment and ink cartridge and ink cassette replacement. Furthermore, for example, the RAM 5 could store and develop the required amount data and perform the superimposed ejection prior to the black ejection. In this way, the arrangement of the recording heads 102 for each color could be selected as desired.

FIG. 5 shows another embodiment of the present invention, and the case where the present invention is applicable to an inkjet recording apparatus in the form of a line printer will be explained using this figure.

In FIG. 5, 201A and 201B are a pair of rollers provided to nip and convey the recording medium R in the sub-scanning direction. 202BK, 202)Y, 202M and 20
2C is a full multi-type recording head for recording black, yellow, magenta, and cyan in which nozzles are arranged over the entire width of the recording medium R, and are arranged in that order from the upstream side in the recording medium conveyance direction. 20
0 is the recovery system according to this example, and in the ejection recovery process, the recording head 202B to 202C is used instead of the recording medium R.
to face.

Even for such an inkjet recording apparatus, ejection recovery processing during recording operation can be performed using the same control system and processing procedure as shown in FIGS. 3 and 4.
In the figure, each part 10, 110 related to driving in the main scanning direction is unnecessary).

That is, a procedure similar to that shown in FIG. 4 is started every predetermined amount, for example, every one or several lines or every one or several pages of the recording medium R,
Determine whether black pixels are recorded after the timer check,
In the case of an affirmative determination, when the black pixel comes to a position facing the nozzle involved in processing as the recording medium is transported, the nozzle may be driven to overlap the black pixel. This example also provides the same effects as the previously described example.

In addition, in the above two examples, by driving only the nozzles whose non-use time exceeds a predetermined value for black pixels, that is, pixels whose reflection density and hue are not affected even when ink of other colors is superimposed. Although the ejection recovery process is performed during the recording operation by performing superimposed recording, other nozzles may be driven at the same time if there is a corresponding black pixel. For example, when black vertical ruled lines are recorded in the configuration shown in the first figure, and black horizontal ruled lines are recorded in the configuration shown in the fifth figure, all the nozzles of other colors are driven to eject. You can let them do it. Furthermore, although the case where a separate recording head is provided for each color is described above, any type of inkjet recording device that performs superimposed ejection to record an image may be used; for example, an integrated recording head may be used. The present invention can be effectively and easily applied even when ejection ports for multiple types (colors, etc.) of ink are formed.

Furthermore, on the upper side, Y, M, C
Although the present invention is applied to an inkjet recording apparatus equipped with the recording heads shown in FIGS. Of course. For example, it may be possible to perform recording in two colors including black (for example, black and red). Alternatively, since black can also be expressed using the three colors Y, M, and C, in a device that uses these three colors and other types of ink, other types of ink may be superimposed on the black pixels of the above three colors. You may also do so. Furthermore, the present invention can be applied to an apparatus capable of expressing gradations using a plurality of types of ink having different densities.

[Effects of the Invention] As described above, according to the present invention, when performing ejection recovery of the recording head by preliminary ejection, if there is a black pixel, it is performed by superimposing it, so that the waste ink storage member Since the amount of waste ink introduced into the printer is reduced, the waste ink storage member can be made smaller and the complexity of waste ink disposal can be reduced, and since the ejection recovery process is performed during the recording operation, the throughput of recording can be improved. Furthermore, efficient ejection recovery reduced ink consumption and the frequency of ink replenishment and ink cassette replacement.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an example of the configuration of a serial printer type device as an embodiment of the inkjet recording apparatus of the present invention, FIG. 2 is a perspective view showing details of the recording head in FIG. 1, and FIG. 1 is a block diagram showing an example of the configuration of a control system related to the apparatus shown in FIG. 4; FIG. 4 is a flowchart showing an example of a recording processing procedure etc. by the control system shown in FIG. As an example, it is a perspective view showing a Hitotsubashi example of an inkjet recording device in the form of a line printer. 1...-cpu. 3...ROM. 5...RAM. 7...Timer, lO...Carriage motor drive circuit 1.20...Line feed motor drive circuit, 128, 12Y, 12
M, 12C... Recording head drive circuit, 100... Recovery system, 1028, 102Y, 102M, 102G, 202
8, 202Y, 202M. 202C... Recording head, 103... Cap device, 105-... Waste ink storage member.

Claims (1)

[Scope of Claims] 1) In an inkjet recording device having recording heads each corresponding to a plurality of types of ink, a recording medium not related to pixel formation is placed at a position superimposed on a pixel formed on a recording member with a predetermined type of ink. An inkjet recording apparatus comprising: a control means for ejecting another type of ink; and a processing means for controlling the control means for performing ejection recovery processing for ejecting ink from the recording head. . 2) The inkjet recording apparatus according to claim 1, wherein the predetermined type of ink is black ink. 3) The inkjet recording apparatus according to claim 1, wherein the predetermined type of ink and the other type of ink are the same color, and the predetermined type of ink has a high concentration. Inkjet recording device.