JP2537032B2 - Operation method of ink jet recording apparatus - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for operating an inkjet recording apparatus,
In particular, the present invention relates to a method for operating an inkjet recording apparatus having a unit for preventing or recovering ejection failure of an ink ejection port of a recording head.

[Prior art]

An ink jet recording apparatus supplies ink into a recording head, and drive elements (electrical heat energy converters such as heating elements or electric elements such as piezoelectric elements) corresponding to a plurality of ink ejection openings formed on the front surface of the recording head, for example. A mechanical energy converter is driven based on a data signal to form flying ink droplets from an ink ejection port toward a recording medium (paper or the like) for recording.

In this type of ink jet recording device, in order to prevent clogging of the ink ejection port due to ink thickening due to evaporation of the ink solvent, dust adhesion, air bubble mixing, etc., and to stabilize the printing quality, In some cases, a capping operation of sealing the ink ejection port with a cap and an ink recovery operation of ejecting the ink idly may be performed.

By the way, it is difficult to judge whether or not the ink recovery operation is necessary. Generally, the user visually recognizes the print quality and the judgment is performed.

However, there is a problem that it is difficult to always maintain the stabilization of ink ejection during the recording operation only by such an ink recovery operation.

Further, there is a problem that the ink accumulated in the cap overflows due to the idle discharge and the device is easily contaminated.

〔Purpose〕

The present invention has been made in view of the above prior art,
An object of the present invention is to prevent clogging of an ejection port and always obtain stable ink ejection, and to perform idle ejection and idle suction for recovery operation during a paper feeding operation which is an idle time during a recording operation. By performing the recovery operation without spending extra time, the throughput of the recording operation can be improved by using the paper ejection operation and the paper ejection operation. Ink contamination can be prevented, and the existing suction recovery device can be used to perform each process of idle discharge and idle suction, requiring no special device means and changing only the control circuit. It is an object of the present invention to provide a method for operating an inkjet recording device that can be easily and easily implemented.

〔Overview〕

The present invention relates to a cap for covering an ejection port of an inkjet recording head that ejects ink onto a recording medium to perform recording by driving a driving element that generates energy used to eject ink, and the cap. Suction means connected to the cap for performing recovery by sucking ink from the discharge port through the cap when the discharge port is covered, and a transport means for transporting the recording medium. A method for operating an inkjet recording apparatus, comprising: the recording head and the cap being opposed to each other and the driving element being driven to discharge the recording medium from the ejection port each time the conveying unit conveys the recording medium by a predetermined amount. The suction means is driven at each idle discharge step of discharging ink into the cap and each operation of the transport means to discharge the recording medium. The method of operating an ink jet recording apparatus characterized by having a dry suction step of discharging from within the cap to suck the ink in the cap without sucking ink from the discharge port and,
The above object is achieved.

〔Example〕

 The present invention will be specifically described below with reference to the drawings.

FIG. 1 shows a plan view of a main part of an inkjet recording apparatus suitable for carrying out the method of the present invention.

In FIG. 1, a guide shaft 3 is installed in front of a recording medium 2 such as a sheet of paper or a plastic sheet backed up by a platen 1, and a plurality of carriages (shown in the figure) are mounted on a carriage 4 which moves in the direction of arrow A along the guide shaft. Four recording heads 5A, 5B, 5C and 5D are mounted.

On the front surface of each recording head 5A to 5D, as shown in FIG. 2, a plurality of ink discharge ports (examples of dots) 9A to
9D is provided, and recording is performed on the recording medium 2 by driving each ink ejection port based on a data signal.

The plurality of recording heads 5A to 5D are generally provided for recording using respective ink colors for color printing (cyan, magenta, yellow, black) or dark and light inks of the same hue.

The recording medium 2 is fed in the direction of arrow B by a paper feeding roller (a roller-shaped platen 1 also serves as a paper feeding roller in the illustrated example) 1 which is a conveying means.

A pump suction type ink recovery means 6 is provided at the home position HP of the carriage 4.

This ink recovery means is driven forward and backward with respect to the recording heads 5A to 5D in the direction of arrow C to close the ink ejection ports at the time of forward movement, and a suction pump (negative pressure source) for sucking a negative pressure in the cap. 8 and.

However, during the recording (printing) operation, the above recording apparatus recovers the ink from the recording heads 5A to 5D together with the carriage 4 for each predetermined paper feed amount of the recording medium 2, that is, for each constant paper feed length L. The means 6 is moved to a position facing the cap 7 (home position HP in the illustrated example), the cap 7 is moved forward to cap, and the drive element corresponding to each ink ejection port is driven to move the ink into the cap. It operates so as to perform blank discharge.

Further, this recording apparatus operates so as to drive the suction pump 8 for each discharging operation of the recording medium 2 to suck and discharge the ink in the cap 7.

FIG. 3 is a block diagram of a control system for controlling the above operation.

In FIG. 3, the CPU (control circuit) 10 of the printing apparatus is a first driver (drive circuit) 11 and a second driver on the carriage 4.
Of the recording head 5A via the second driver 12 by driving the carriage motor 13, the paper feed motor 14, the motor 15 for operating the ink recovery means 6 and the like via the first driver 11. The ~ 5D ink ejection ports 9A to 9D are driven.

The motor 15 for operating the ink recovery means is commonly used for driving the cap 7 forward and backward and for driving the suction pump 8, but in some cases, these may be driven by separate motors.

In addition, the control program of the control system of FIG.
It is stored in the ROM attached to.

Further, the CPU 10 feeds a predetermined amount of the recording medium 2 as a recording material during the recording operation (the constant paper feed length L).
An empty discharge timing sensor 16 for detecting that there is
A suction timing sensor 17 for detecting that the recording medium 2 has been ejected is connected to these sensors 16,
Based on the detection signal from 17, the operating method according to the invention is carried out.

FIG. 4 is a flow chart showing the operation procedure of the control system of FIG.

In FIG. 4, when the power of the recording apparatus is turned on, the operation is started in step 100, the presence or absence of a print signal is determined in step 101, and if there is no print signal, the process proceeds to step 102 to enter the print standby state.

If there is a print signal in step 101, the process proceeds to step 103, and it is determined whether or not there is a constant paper feed length L, and NO
In the case of, the process returns to step 101 repeatedly, but if YES, the process proceeds to step 104, where the carriage 4 is moved to a position facing the ink recovery means 6 (normal home position HP) and the recording head 5A is moved.
.About.5D is capped, and then in step 105, the ink ejection ports 9A to 9D are driven to idle eject ink into the cap 7.

In step 106 following this, it is determined whether or not the recording medium 2 is ejected.

If the decision result in the step 106 is NO, the process is returned to the step 101 and the above operation is repeated, but if the decision result is YES, the process proceeds to the step 107 to drive the suction pump 8 to drive the inside of the cap 7 inside. Negative pressure suction (empty suction) of ink is performed.

Next, the presence or absence of the print signal in step 108 is determined. If yes, the process returns to step 101 and the above operation is repeatedly executed. If no, the process proceeds to step 109 to enter the print standby state.

According to the operation method of the inkjet recording apparatus described above, in a multi-head (a plurality of recording head mounted type) recording apparatus, during a recording (printing) operation, a specific recording head or a specific dot (ink ejection) of each recording head is used. Even when a part of the outlet is not used (driven) for a long time, it is carried out for each predetermined paper feed amount of the recording medium 2, that is, a constant paper feed length L.
Since the blank discharge is performed for each dot, the ink in each dot, that is, the ink discharge ports 9A to 9D, is prevented from being dried or thickened, and stable ink discharge can be obtained at all times to maintain good print quality.

Further, since the idle discharge process is performed for each predetermined feed amount of the recording medium 2 and the idle suction process is performed for each discharge operation of the recording medium 2, these idle discharge and idle suction operations are a paper time which is an idle time during the recording operation. This can be performed by utilizing the feeding operation and the paper discharging operation, and therefore, the recovery operation can be performed without spending extra time, and the throughput of the recording operation can be improved.

Further, since the negative pressure of the ink in the cap 7 is automatically sucked every time the recording medium 2 is ejected, the ink amount in the cap can be always kept below a certain level, and the contamination of the device due to the overflow can be prevented. I was able to.

Furthermore, since the idle discharge of the ink and the suction of the negative pressure inside the cap 7 are performed using the existing ink recovery device 6, it is possible to carry out by changing only the control circuit without requiring any special device means, and the configuration is extremely simple. Is.

Although the four recording heads 5A to 5D are provided in the illustrated embodiment, the present invention can be similarly implemented regardless of the number of recording heads including the case of one recording head.

〔effect〕

As is clear from the above description, according to the present invention, the ejection element of an inkjet recording head that ejects ink onto a recording medium to perform recording by driving a driving element that generates energy used for ejecting ink. A cap for covering the outlet; a suction means connected to the cap for performing recovery by sucking ink from the ejection port through the cap when the cap covers the ejection port; A method for operating an inkjet recording apparatus, comprising: a conveying unit configured to convey a recording medium, wherein the recording head and the cap are opposed to each other each time the conveying unit conveys the recording medium by a predetermined amount. A blank discharge step of driving a drive element to discharge ink from the discharge port into the cap; For each discharging operation, the suction means is driven to suck the ink in the cap without sucking the ink from the ejection port, and the empty suction step of discharging the ink from the cap is provided. Prevents clogging of the ejection port and always obtains stable ink ejection. Perform each step of idle ejection and idle suction by using the paper feed operation and paper ejection operation, which are free time during recording operation. Therefore, it is possible to improve the throughput of the recording operation by performing the recovery operation without spending extra time.
It is possible to prevent overflow of ink in the cap to prevent ink contamination of the device, and also to use the existing suction recovery device to perform each process of idle discharge and idle suction, which is a special device. There is provided a method of operating an inkjet recording apparatus which does not require any means and can be simply and easily implemented by changing only a control circuit.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of a main part of an inkjet recording apparatus suitable for carrying out the method of the present invention, FIG. 2 is a front perspective view of the recording head in FIG. 1, and FIG. Is a block diagram of a control system suitable for carrying out the method of the present invention, and FIG. 4 is a flowchart showing the operating means of the control system of FIG. 5A to 5D ... Recording head, 6 ... Ink recovery means, 7 ...
Cap, 8 ... Suction pump, 9A to 9D ... Ink ejection port (dot row), A ... Arrow for carriage (recording head) movement direction, B ... Arrow for paper feed direction, C ... For capping Movement arrow.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hideki Yamaguchi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (56) Reference JP-A-54-9928 (JP, A) JP-A-59 -7053 (JP, A) JP-A-60-13556 (JP, A) JP-A-60-71259 (JP, A)

Claims (6)

(57) [Claims] 1. A cap for covering an ejection port of an ink jet recording head for ejecting ink onto a recording medium for recording by driving a driving element that generates energy used for ejecting ink, Suction means connected to the cap for performing recovery by sucking ink from the ejection port through the cap when the cap covers the ejection port, and a transporting device for transporting the recording medium. And a method of operating an inkjet recording apparatus including: each time the conveying unit conveys the recording medium by a predetermined amount,
A blank discharge step of causing the recording head and the cap to face each other and driving the drive element to discharge ink from the discharge port into the cap; and, for each operation of the transport unit discharging the recording medium, A method of operating an inkjet recording apparatus, comprising: a step of driving a suction unit to suck the ink in the cap without discharging the ink from the ejection port and discharging the ink from the cap. 2. The method for operating an ink jet recording apparatus according to claim 1, wherein the drive element is an electrothermal converter. 3. The method of operating an ink jet recording apparatus according to claim 2, wherein the electrothermal converter is a heating element. 4. The method of operating an ink jet recording apparatus according to claim 1, wherein the drive element is an electromechanical converter. 5. The method of operating an ink jet recording apparatus according to claim 4, wherein the electromechanical converter is a piezo element. 6. The method for operating an ink jet recording apparatus according to claim 1, wherein a plurality of the recording heads are provided, and the cap collectively covers the ejection ports of the plurality of recording heads.