JPS63224957A - Ink jet recorder - Google Patents

Abstract

PURPOSE:To achieve saving of ink by miniaturizing an ink recovery system, by connecting a plurality of recording heads to one piece of a suction pump via an individual switch valve. CONSTITUTION:A switching valve unit 25 is installed between a cap unit 14 sticked fast to a plurality of recording heads and a single suction pump 13. Switching valves 25A-25D corresponding to respective recording heads in this switching valve unit 25 are selectively opened and shut, and ink recovery action by a suction pump 13 is carried out to a recording head corresponding to an opened switching valve. Thus by providing the switching valves 25A-25D, an ink recovery system can be miniaturized and ink is saved by eliminating useless ink suction.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an ink recovery device for an inkjet recording apparatus including a plurality of recording heads, such as a color inkjet printer.

(Prior Art) An inkjet recording apparatus supplies ink to the recording head, drives driving elements corresponding to a plurality of ink ejection ports formed on the front surface of the recording head based on a data signal,
In this method, flying ink droplets are formed from an ink ejection port toward a recording medium, and the ink droplets are attached to record.

In this type of inkjet recording device, when unpacking,
To maintain good ink ejection by uniformly filling the ink supply system with ink without interruption when replacing ink or recording heads, or ink ejection openings caused by dust, thickened ink adhesion, or air bubbles. Ink recovery involves sealing the ink ejection port with a cap and generating a negative pressure suction force within the cap using a negative pressure source to suck ink through the ink ejection port in order to eliminate clogging and maintain image quality. An operation is being performed.

Furthermore, a color inkjet recording apparatus is equipped with four recording heads corresponding to four color inks, for example, cyan, magenta, yellow, and black. Also,
Even when using dark and light inks of the same hue, the number of recording heads corresponding to the type of ink is mounted.

By the way, conventional ink recovery devices for inkjet recording devices with multiple heads have a structure in which a suction pump is provided for each recording head and each of these is connected to a cap of each head via a suction tube, or a structure in which a suction pump is provided for each recording head and a suction pump is connected to a cap of each head through a suction tube, or a suction pump is provided for each recording head. One suction pump was used and this suction pump was connected to each cap.

However, the former structure has problems in that the structure is complicated due to the large number of pumps and that it requires a large amount of space.

On the other hand, in the latter structure, ink is sucked from all print heads even when a single print head with ejection failure is recovered, so a large amount of ink is wasted (uneconomical) during recovery. There was a problem.

〔the purpose〕

An object of the present invention is to solve the problems of the prior art, and to enable recovery of a specific head using one negative pressure source.
To provide an inkjet recording device in which a recovery system for a plurality of color recording heads can be configured compactly, and ink is not sucked from a normal head, resulting in excellent ink economy.

[Means to achieve the purpose]

The present invention provides an inkjet recording device that is equipped with a plurality of recording heads and in which a cap connected to a negative pressure source via a suction tube can be brought into close contact with each recording head. The above object is achieved by connecting to one negative pressure source and providing a switching valve for each suction tube to turn on and off the communication.

〔Example〕

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

FIG. 5 shows an inkjet recording apparatus suitable for carrying out the present invention.

In FIG. 5, a sheet (recording medium) 3 is moved along a guide shaft 4.4 to the front surface of a sheet (recording medium) 3 that is fed in the direction of arrow A through sheet feeding rollers l and 2 that are installed at a predetermined interval above and below. A carriage 5 is provided, and a plurality of (four (II) in the illustrated example) recording heads 6 are mounted on the carriage.
A, 6B, and 6C16D are installed.

A plurality of ink ejection ports for forming dots are formed in a predetermined array (usually one vertical row) on the front surface of each of the recording heads 68 to 6D.

The carriage 5 is reciprocated in the direction of the arrow by a carriage drive motor 8 via a belt transmission mechanism 9.

In the case of color image formation, the four recording heads 6A to 6
D is used for recording with each ink color of cyan, magenta, yellow, and blank, for example.

During recording, in synchronization with the movement of the carriage 5 in the sheet 3 direction, the driving elements of each ink ejection port group of the rads 6A to 6D are driven to move the ink ejection ports from the sheet 3 to each recording.
Recording is performed while forming flying ink droplets that fly towards the target.

After recording ends, the carriage 5 returns to the home position HP outside the recording range.
A pump suction type ink recovery device 10 is provided at the home position.

The gsB diagram shows an ink recovery device 10.

In FIG. 6, a motor 12 as a drive source and a suction pump 13 for ink recovery are mounted on a frame 11, and caps 14A, 14B, 14C corresponding to each recording head 6A to 6D are mounted on the front part. , 14D are guided and supported so as to be able to move forward and backward in the direction of arrow F, and when the carriage 5 is at the home position, each cap 14A to 14D is moved forward and brought into close contact with each recording head 6A to 6D to perform capping. ing.

A porous ink absorber 15 is provided on the front surface (close contact surface) of each cap 14A to 14D.

Inside each cap 14A to 140 is a suction tube 16A.
, 16B, 16C, 16D via one suction pump 1
3, and a waste ink tube 17 for discharging the sucked ink is connected to the discharge side of the suction pump.

Further, the suction tubes L6A-16D are connected to a switching valve unit 25 consisting of four individually controlled switching valves, and the switching valve unit and the suction pump 13 are connected by a common suction tube 16.

On the frame 11 are the caps 14A to 14D.
a cap drive gear 19 having an inner cam 18 that drives the suction pump 13 back and forth; and an end cam 20 that drives the suction pump 13.
A pump drive gear 21 having a pump drive gear 19,21 is pivotally supported, and these gears 19,21 are driven by the motor 12 via a gear train.

A lever 2 is located between the pump drive gear 21 and the suction pump 13.
2 is pivotally supported, and the lever 2z is swung by the change in lift of the end cam 20 as the pump drive gear rotates, and the suction pump 13 is driven by the movement of the lever 22.

In the illustrated example, the entire ink recovery device 10 is also driven in the direction toward and away from the recording heads 6A to 6D.

The recovery operation by ink suction is performed by driving the suction pump 13 while the carriage 5 is at the home position HP (FIG. 1) and the caps 14A to 14D are in close contact with the recording heads 6A to 6D. This is done by sucking out ink from an ink supply system through an ink discharge port using suction force.

FIG. 1 shows the structure of an ink suction system between a plurality of caps 14A to 14D and a suction pump 13 according to the present invention.
The figure shows a cross section taken along the line ■--■ in FIG.

In FIGS. 1 and 2, caps 14A to 14D
A cap unit 14 consisting of a negative pressure source (suction pump)
13, 4 corresponding to each cap 14A to 14D
A switching valve unit 25 consisting of 11 m long switching valves 25A, 25B, and 25C125D is provided.

The cap unit 14 and the switching valve unit 25 are each cap 14A-140 and each switching valve 2 corresponding to these.
Separate suction tubes 16A for each of 5A to 25D
-160, and the switching valve unit 25
and one pump 13 have one common suction tube 16
connected with.

Each of the switching valves 25A to 25D is composed of a solenoid valve, and is arranged to individually turn on and off communication between each suction tube L6A-160 and the common suction tube 16 (or suction pump 13). .

In FIG. 2, the switching valve 25A (A to D have the same structure, so only A will be described below) includes an electrically controlled solenoid 26, a plunger 27 driven by the solenoid, and a plunger 27 driven by the solenoid. As shown in the figure, it is comprised of a return spring 28 that biases it to the closed position, and the entire body is housed within a housing 29.

A common passage 30 connected to the common suction tube 16 and four individual chambers 31A (31A to 31D) connected to the common passage and each individual suction tube 16A (16A to 16D) are formed in the housing 29. The structure is such that communication between the individual chamber 31A and the common passage 30 is turned on and off by the movement of the plunger 27.

111 [! ! ! I is a flowchart illustrating the operation of the ink recovery system described above, and FIG. 4 is an explanatory diagram illustrating the recovery operation display on the operation panel.

In FIG. 3, when the recovery operation is started in step 100, it is first determined in step 101 whether or not there is an ink empty state in any of the ink colors, and if there is no ink empty state, visual confirmation is performed in step 102. Perform post-recording (normal state).

If the ink is empty in step 101, it is automatically detected whether the ink is empty or not for all ink colors in a fixed order in steps 103 to 106.

At the same time as the empty state is determined by the empty check for each ink color, a display indicating the empty state is performed in steps 103A to 106A.

This empty state is preferably displayed on the operation panel 40, for example, by a method as shown in FIG.

That is, on the operation panel 40, there is a display 41 that numerically indicates the ink color in the empty state, a switch 42 for specifying the changeover valves 25A to 25D (selection of the changeover valve to be communicated), a recovery operation switch 43, and an ink LED (indicates that the recovery operation is in progress). lit) 44
is provided.

In the illustrated example, for example, the number "2" on the display 41 indicates that magenta is empty, and in this case, if the ink LED 44 is on, the magenta switching valve 25B is opened and the recovery operation is enabled. be done. This switching valve operates in conjunction with the recovery switch operation.

In FIG. 3, after the above display is performed in steps 103A to 106A, the designation switch 42 is turned on in steps 103B to 106B, and the recovery operation switch 43 is turned on in step 107 to start the ink recovery operation by the suction pump 13. This is performed for the desired recording head(s).

Note that in certain cases, such as when an ink cartridge is replaced, the recovery operation switch is generally turned on automatically in step 107.

According to the embodiment described above, since the switching valves 25A to 25D that connect and disconnect communication with the pump 13 are provided corresponding to the plurality of recording heads 68 to 6D, one suction pump 13 is provided.
This makes it possible to recover from ink empty or ejection failure only for a specific head among the plurality of printheads 6A to 6D, allowing a compact recovery system for multiple printheads and eliminating unnecessary ink suction from normal ejection heads. It is now possible to eliminate.

Furthermore, by configuring a sequence to perform a recovery operation on each of the recording heads 6A to 6D, the capacity of the suction pump 13 can be minimized, and conversely, a stronger recovery operation can be achieved with the same pump capacity as before. We were also able to achieve the effect of obtaining

〔effect〕

As is clear from the above description (according to the present invention, multiple recording heads and one suction pump are connected via individual switching valves, the ink recovery system can be configured compactly. Provided is a multi-head inkjet recording device that can save ink by eliminating wasteful ink suction.

[Brief explanation of drawings]

FIG. 1 is a schematic perspective view of an ink recovery system of an inkjet recording apparatus according to the present invention, FIG. 2 is a sectional view taken along line -H in FIG. 1, and FIG. Flowchart showing the operating procedure, FIG. 4 is a schematic explanatory diagram of the display section of the operation panel, FIG. 5 is a perspective view of an inkjet recording apparatus implementing the present invention, and FIG. 6 is a perspective view of the ink recovery device shown in FIG. 5. It is a diagram. 6A to 6D--=-----1. Recording head, 10.
...--Ink recovery device, 12---------------------
-Motor, 13.--Suction pump, 1
4A~14D----------Cap, 16
A~l 6 I) -------1 suction tube, 2
5A~25 I) -・-・-・-Switching valve, HP・-・-
・−・−Home position. Agent Patent Attorney Yasushi Ooto Figure 1 Figure 2 Figure 4 Figure 5

Claims (1)

[Claims] (1) In an inkjet recording device equipped with a plurality of recording heads and in which a cap connected to a negative pressure source via a suction tube can be brought into close contact with each recording head, the plurality of suction tubes connected to each cap can be connected to one An inkjet recording device configured to be connected to two negative pressure sources, and provided with a switching valve for each suction tube to turn on and off the communication.