JPH07242000A - Inkjet recording device - Google Patents

Abstract

(57) [Summary] [Purpose] To recover the head with a simple structure and without affecting the printing speed. [Structure] A platen drive gear 7 is attached to the platen 3, and the platen drive gear 7 is connected to a motor 6
Is connected to the drive gear 6a. A suction pump drive gear 8 is attached to the platen 3, and the suction pump drive gear 8 is connected to a drive gear 16 a that drives the suction pump 9. The suction pump 9 communicates with the cap 10 and the waste ink tank 11. Then, when the motor 6 is driven, the platen 3 and the suction pump 9 are operated, and the ink in the head 1 is sucked at the same time when the recording medium 5 is conveyed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus.

[0002]

2. Description of the Related Art In an ink jet recording apparatus, ejection failure such as dot omission occurs due to increase in viscosity due to drying of ink, clogging of nozzles due to entry of dust or the like, and penetration of bubbles. As a method of preventing this ejection failure, conventionally, as disclosed in JP-A-59-222360, a mechanism for sucking bubbles and dust with ink from a nozzle of a head is provided by using a negative pressure. It prevented the discharge failure of.

In Japanese Patent Laid-Open No. 4-25467, a paper feed motor for conveying a recording medium and a negative pressure source motor for sucking ink are provided, and the motors are individually driven. A technique for performing the ink suction operation when the recording medium is ejected is disclosed.

[0004]

However, in the technique disclosed in Japanese Unexamined Patent Publication No. 4-25467, a paper feed motor for conveying a recording medium and a negative pressure source motor for sucking ink are respectively provided. Since they are required individually, there are problems that the cost is high and the control is complicated.

Therefore, in Japanese Patent Laid-Open No. 63-53048, negative pressure generating means for sucking ink and a platen for conveying a recording medium are connected to a single motor through a switching means. A technique is disclosed in which the switching unit transmits the driving force of the motor to the negative pressure generating unit or the platen, and the single motor sucks the ink and conveys the recording medium.

However, in the technique disclosed in Japanese Patent Laid-Open No. 63-53048, since the driving force of the single motor is transmitted by switching between the negative pressure generating means and the platen, a switching means for that is required, and the structure is constituted. Becomes complicated. Furthermore, when the recording medium such as paper or OHP sheet is discharged, the driving force of the motor is transmitted to the platen, so that the negative pressure generating means cannot be driven. For this reason, the ink suction operation must be performed after the recording medium is ejected or interrupted during the printing on the recording medium. Therefore, there is a problem that the printing speed is reduced.

The present invention has been made to solve the above-mentioned problems, and it is possible to perform an ink suction operation and a recording medium conveying operation by a single driving means.
Moreover, it is an object of the present invention to provide an inkjet recording device that does not affect the printing speed.

[0008]

In order to achieve this object, according to a first aspect of the present invention, there is provided an ink jet recording apparatus having a suction means for sucking ink from a nozzle of a head and a conveying means for conveying a recording medium. , A single drive means that is connected to the suction means and the transport means and that drives the suction means and the transport means at the same time.

According to a second aspect of the present invention, the suction means includes a cap that surrounds the nozzle of the head, and a pump mechanism that communicates with the cap and that generates a negative pressure in the cap, and the drive means. , And is connected to the pump mechanism.

According to a third aspect of the present invention, the driving means is a motor.

[0011]

In the ink jet recording apparatus of the present invention having the above structure, the single driving means connected to the suction means and the carrying means simultaneously drives the suction means and the carrying means, During the transport operation of the recording medium by the transport means, bubbles, dust, and the like are sucked together with the ink from the nozzles of the head by the suction means, and ink non-ejection is prevented.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing the structure of the ink jet recording apparatus of this embodiment. As shown in FIG. 1, a head 1 that ejects ink from nozzles (not shown) is mounted on a carriage 2, and the carriage 2 is moved along a platen 3 by a drive source (not shown). On the right side of the platen 3 in FIG. 1, the platen drive gear 7
The platen drive gear 7 is connected to the drive gear 6 a attached to the motor 6. The recording medium 5 conveyed to the platen 3 is
The driving force of the motor 6 is transmitted to the platen 3 by the driving gear 6a and the platen driving gear 7, the platen 3 is rotated, and the recording medium 5 is conveyed and discharged. The recording medium 5 up to the platen 3
The paper feeding is performed by a known paper feeding means (not shown). This paper feeding means comprises a paper feeding roller and a switching means, and transmits the driving force of the motor 6 to the paper feeding roller via the switching means. Then, the switching unit is controlled so that the driving force of the motor 6 is not transmitted to the sheet feeding roller when the sheet is discharged. In addition, ink is ejected from the head 1 as the carriage 2 moves, and image data is printed on the recording medium 5.

A suction pump drive gear 8 is attached to the left side of the platen 3 in FIG. 1, and the suction pump drive gear 8 is connected to a drive gear 16a for driving the suction pump 9. The suction pump 9 communicates with the cap 10 and the waste ink tank 11, sucks ink from the nozzle of the head 1 through the cap 10, and discharges the sucked ink to the waste ink tank 11.

Next, the structure of the suction pump 9 will be described with reference to FIG. The suction pump 9 is provided with a cylinder 12 communicating with the suction hole 23 of the cap 10. Inside the cylinder 12, a piston 13 having a seal rubber 14 is provided. One end is rotatably connected. Also rod 1
The other end of 5 is rotatably connected to an eccentric position of a crank disk 16, and the crank disk 16 is connected to a drive gear 16a. Therefore, when the platen 3 rotates, the crank disk 16 is rotated via the suction pump drive gear 8 and the drive gear 16a, and the rotational movement thereof is converted into a linear movement by the rod 15 and the cylinder 12 and transmitted to the piston 13. The piston 13 reciprocates up and down in the cylinder 12. The vertical movement of the piston 13 changes the internal pressure of the cylinder 12.

A one-way valve 18 is provided at the communication port of the cylinder 12 with the cap 10. The one-way valve 1
8 opens when the inside of the cylinder 12 becomes negative pressure, and closes when it becomes positive pressure. The cylinder 12 communicates with the waste ink tank 11, and a one-way valve 19 is provided at the communication port with the waste ink tank 1. The one-way valve 19 opens when the inside of the cylinder 12 has a positive pressure, and closes when the inside of the cylinder 12 has a negative pressure.

Next, the cap 10 is arranged parallel to the nozzle surface of the head 1 at the home position, and is separated from the nozzle surface of the head 1 by a solenoid 22 at a capping position where the cap 10 is in close contact with the nozzle surface of the head 1. Moved to the separated position.

In the above construction, when the platen 3 is driven by the motor 6, the driving force thereof drives the ink pump 9 via the ink pump drive gear 8. That is,
The crank disk 16 is rotated by the rotation of the drive gear 16a connected to the ink pump drive gear 8, and the piston 13
Moves up and down, the internal pressure of the cylinder 12 changes.
Then, due to the downward movement of the piston 13, a negative pressure is generated inside the cylinder 12, the suction valve 18 of the cylinder 12 is opened, and the discharge valve 20 is closed. Further, the upward movement of the piston 13 generates a positive pressure inside the cylinder 12, so that the suction valve 18 of the cylinder 12 is closed and the discharge valve 20 is opened.

Therefore, when the carriage 2 returns to the home position and the cap 10 is brought into close contact with the nozzle surface of the head 1 by the solenoid 22, the platen 3 is driven by the motor 6 to eject the recording medium 5, The piston 13 moves downward and a negative pressure is generated in the cylinder 12, and the cap 10 that is in close contact with the nozzle surface of the head 1
Ink containing bubbles and the like is drawn from the nozzle through the suction port 17
And flows into the cylinder 12. When the piston 13 is moved upward by the further driving of the platen 3 and a positive pressure is generated in the cylinder 12, the ink sucked by the above operation is discharged from the discharge port 18 to the waste ink tank 11. .

Next, the operation of the ink jet recording apparatus of this embodiment will be described with reference to the flow chart of FIG.

After the power of the ink jet recording apparatus is turned on, until the print signal from the outside enters the printer control circuit (not shown), the control circuit executes the step S1.
(Hereinafter, referred to as S1 and other steps are similarly referred to), the print standby state is determined (S1, No), and the solenoid 22
Is operated to bring the cap 10 into close contact with the nozzle surface of the head 1. At this time, the carriage 2 carrying the head 1 is located at the home position. When a print signal is input to the printer control circuit (S1, Yes
s), the motor 6 is driven, and the recording medium 5 is fed by the paper feeding means (S2). At this time, since the platen 3 and the suction pump 9 are simultaneously driven, the suction pump 9 sucks the ink in the head 1 (S3). Then, when it is confirmed that the recording medium 5 has been fed to the position of the platen 3 (S4, Yes), the solenoid 22 is activated and the cap 10 is removed from the nozzle surface of the head 1 (S5). After that, the carriage 2 moves from the home position to the recording medium 5
To the print area in which the carriage 2 is arranged (S6), and the carriage 2
Ink is ejected from the head 1 along with the movement of the print area to print on the recording medium 5 (S7).

During printing, "ink end", "
Check if an interrupt signal such as "Page break", "Print stop", "Print end", etc. does not enter the printer control circuit (S
8). When the interrupt signal comes into the printer control circuit (S8, Yes), the carriage 2 is moved to the home position (S9). Then, it is determined whether or not the interrupt signal is a "print end" signal (S10). If it is determined that the interrupt signal is a "print end" signal (S10,
Yes), the solenoid 22 brings the cap 10 into close contact with the nozzle surface of the head 1 (S11). After that, the platen 3 is driven by the motor 6 to eject the recording medium 5 (S12). At this time, the suction pump 9 is simultaneously driven to suck the ink in the head 1 (S13). Then, when it is confirmed that the recording medium 5 is ejected (S14, Yes
s), the standby state is set.

If it is determined that the interrupt signal is not the "print end" signal (S10, No), it is determined whether the interrupt signal is "page break" (S15). If it is determined that the interrupt signal is not "page break" (S15, N
o) After performing a predetermined process (S16), the process returns to S6 to restart printing. And the interrupt signal is "Page break"
If it is determined that the value is (S16, Yes), the solenoid 2
2 brings the cap 10 into close contact with the nozzle surface of the head 1 (S17). After that, the platen 3 is driven by the motor 6 to eject the recording medium 5 (S18). At this time, the suction pump 9 is simultaneously driven to suck the ink in the head 1 (S19). When it is confirmed that the recording medium 5 has been ejected (S19, Yes), the recording medium 5 to be printed by the motor 6 is fed by the paper feeding means (S21). At this time, the suction pump 9 is also operated at the same time to suck the ink in the head 1 (S2).
2). Then, when it is confirmed that the recording medium 5 has been fed to the position of the platen 3 (S23, Yes), the solenoid 22 is activated to remove the cap 10 from the nozzle surface of the head 1 (S24), and the process returns to S6. Resume printing.

According to the ink jet recording apparatus of the above-described embodiment, the platen 3 and the suction pump 9 are simultaneously driven by the single motor 6 so that the ink is not ejected when the recording medium 5 is discharged and fed. Since bubbles or dust that cause the problem are sucked in, the conventional switching means is not required and the structure is simplified, and the decrease in printing speed due to the time required for nozzle recovery can be almost ignored. .

The amount of ink suction required to remove bubbles and dust is, for example, about 0.05 to 0.1 cc, and the printer control circuit controls the opening / closing time of the cap 10 by the solenoid 22. This makes it possible to adjust the ink suction amount regardless of the discharge time of the recording medium 5.

Further, in this embodiment, since the nozzle surface of the head 1 is capped when the recording medium 5 is fed / discharged,
In particular, when the recording medium 5 is discharged, dust such as paper powder and fibers of the recording medium 5 due to friction in the supply path of the recording medium 5 does not adhere to the nozzle surface of the head 1, and it is possible to prevent ejection failure. .

Although the cylinder 12 and the piston 13 are used for the suction pump 9 in this embodiment, for example, a cam-shaped crank disk is engaged with the expandable bellows to rotate the crank disk. A pump mechanism for suctioning and discharging may be provided by expanding and contracting the bellows portion.

[0028]

As is apparent from the above description, according to the ink jet recording apparatus of the present invention, the single driving means connected to the suction means and the carrying means has the suction means and the carrying means. By simultaneously driving the means, during the conveying operation of the recording medium by the conveying means,
Since ink is sucked from the nozzle of the head by the suction means, ink non-ejection due to air bubbles, dust, etc. can be performed with a simple structure that does not use a switching means as in the past, and also for recovering the nozzle. The decrease in printing speed with time can be almost ignored.

[Brief description of drawings]

FIG. 1 is a perspective view showing a configuration of a main part of an inkjet recording apparatus according to an embodiment of the present invention.

FIG. 2 is a sectional view showing the structure of the ink pump of the embodiment.

FIG. 3 is a flow chart showing an operation of the inkjet recording apparatus of the above-described embodiment during ink suction.

[Explanation of symbols]

 1 Head 2 Carriage 3 Platen 6 Motor 9 Ink Pump 10 Cap 12 Cylinder 13 Piston 16 Crankboard

Claims (3)

[Claims] 1. An inkjet recording apparatus having a suction means for sucking ink from a nozzle of a head and a transport means for transporting a recording medium, the suction means and the transport means being connected to the suction means and the transport means. An inkjet recording apparatus comprising: a single driving unit that drives the unit and the unit, and the suction operation is performed by the suction unit during the transport operation by the transport unit. 2. The suction means includes a cap that surrounds the nozzle of the head, and a pump mechanism that communicates with the cap and that generates a negative pressure in the cap, and the drive means includes the pump. The inkjet recording apparatus according to claim 1, wherein the inkjet recording apparatus is connected to a mechanism. 3. The ink jet recording apparatus according to claim 1, wherein the driving unit is a motor.