JPH04156338A - Ink jet recording device - Google Patents

Abstract

PURPOSE:To facilitate the return of a printing head whose printing has once been inoperable, achieve the miniaturization of an ink jet recording device and reduce the cost of said device by a method wherein the printing head and a discharging means are set on a carriage, the discharging means is operated by pressing a part thereof against a frame, and a capping means is positioned at the moving end of the carriage. CONSTITUTION:A printing head 1 is set on a carriage 4 together with an ink tank 2 and a pump 3. A piston 5 is operated in the moving direction (horizontal scanning direction) of the carriage 4 by an external force that works in the direction shown by the arrow A. When the external force is eliminated, the piston 5 is permitted to return by means of a return spring 6. The carriage 4 is located in a home position HP. The operation of the pump and a capping operation are carried out in a capping position CP which is on the farther right of the home position HP. When the carriage 4 moves to the left, a cap 15 and a waste liquid case 19 move to the left together with the carriage 4. Simultaneously, the piston 5 is permitted to return by the spring force of the return spring 6, and ink in the pump 3 moves to the fore side of the piston 5.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an inkjet recording device, and particularly to a mechanism for removing air bubbles, dust, etc. from a print head, and a protection mechanism for the print head.

[Prior Art] Conventionally, in an inkjet recording apparatus, an ink discharging means was as shown in Japanese Patent Application Laid-Open No. 61-230940 shown in FIG. A carriage 21 carrying a print head 20 moves in the main scanning direction along a guide shaft 23 and records on a recording paper 25 fed by a platen 24. When discharging ink to remove air bubbles, dust, etc. from the head, the following operation is performed. Carriage 21 is available on HP (
home position). A cap 26 operated in the direction of the arrow by external power comes into contact with the print head 20,
A suction pump 28 , which is powered separately from the cap 26 , sucks ink from the print head 20 through a tube 27 . In this way, a dedicated motor and complicated mechanism were installed to discharge ink and protect the head, and a dedicated control unit was also required to control them.

[Problems and Objectives to be Solved by the Invention] The inkjet recording device as described above not only requires space to accommodate a dedicated motor and mechanism, but also increases the number of component parts, which increases the cost of the recording device. This resulted in an increase in size and size. On the other hand, in a recording apparatus that does not have the above-mentioned mechanism, there is a problem that once printing becomes impossible due to the influence of air bubbles in the print head or clogging of nozzles due to dust or the like, it is very difficult to recover.

The present invention simplifies the ink ejection means and the capping means for the print head without using a dedicated motor or complicated mechanism, thereby making it possible to easily restore a print head that has become unable to print, and to make the inkjet recording device more compact. The aim is to realize lower prices and lower prices.

[Means for Solving the Problems] The inkjet recording device of the present invention includes a print head in which the nozzle is formed, a discharge means for pressurizing and discharging ink in the print head, and a discharge means for receiving the discharged ink. A capping means is provided, the head and the ejection means are installed on a carriage, and the ejection means is operated by pressing a part of the ejection means against a frame of the inkjet recording apparatus,
Further, the capping means is located at a moving end of the carriage.

[Function] According to the present invention, when the nozzle of the print head becomes unable to print, the carriage carrying the print head and the ejecting means simply moves to the moving end, and the cap is airtightly attached to the nozzle. It can come into contact with the nozzle to protect the nozzle and discharge the ink inside the head. By the above operation, air bubbles, dust, etc. inside the head are discharged, and the nozzle becomes in a stable state, and ink droplets can be ejected again.

[Example] An embodiment of the present invention will be described based on the drawings.

FIG. 1 is a perspective view showing an inkjet recording apparatus of the present invention, FIG. 2 is a sectional view of an ink discharge means according to an embodiment of the present invention, and FIG. 3 is a perspective view of a capping means. The print head 1 is installed on a carriage 4 along with an ink tank 2 and a pump 3. The outer shape of the pump 3 is cylindrical, and the inside is also cylindrical. Inside there is a piston 5 with an outer diameter slightly smaller than the inner diameter of the pump 3. The piston 5 is installed so as to be actuated in the direction of movement of the carriage 4 (main scanning direction) by an external force in the direction of the arrow. When the external force is removed, the piston 5 is returned to its original position by a return spring 6.

Further, the O-ring 7 is interposed between the piston 5 and the pump 3, and has the effect of preventing ink leakage by being slightly compressed. Ink is supplied from an ink tank 2, passes through a print head 1 and a pump 3 installed at the bottom of the ink tank 2, and is supplied to the print head 1 for printing.

During printing, no external force is applied, so the piston 5 does not move, and ink is supplied through a small gap between the pump 3 and the piston 5. When discharging ink, the piston 5 is actuated by an external force in the direction of arrow A having an arbitrary speed, which will be described later. The backflow of ink between the pump 3 and the piston 5 is
Less resistance due to ink viscosity. The ink will be forcibly sent to print head 1.
The ink that was present inside is jetted out from the nozzle 1a at the tip of the print head 1 and replaced with new ink.

At that time, the rear side of the piston 5, that is, the ink tank 2
There will be negative pressure on the side. Therefore, ink is supplied from the ink tank 2 having a relatively high pressure. When the piston 5 returns, the ink moves to the front of the piston 5 instead of the piston 5 moving backward. When the piston 5 returns, its return speed is set so as not to destroy the meniscus due to negative pressure.

Through the above operations, ink is discharged, and air bubbles, dust, etc. are removed from the nozzle 1a.

The carriage 4 is guided by guide shafts 11a and 11b, and is driven by a motor (not shown) via a belt 12 extending in the axial direction of the platen 10. Note that at this time, print head 1
is a position facing the platen 10 with the recording paper 13 in between. In the printing state, ink ejected from the print head 1 soaks into the recording paper 13 to form characters and symbols. During printing standby, the carriage 4 is at the home position HP. The operation of the pump and the capping operation are performed at the capping position CP, which is located further to the right in FIG. 1 than the home position HP. L-shaped lever 14
is attached to the mounting foot 8 so as to be rotatable about the bin 16. 1. On the upper part of the collar 14, a cap 15 is integrated so as to face the print head 1, and a case 19 for storing waste is integrated, further facing the cap 15 and on the opposite side of the cap 15 from the print head 1. installed.

This integrated member can be moved by a certain amount in the direction of arrow B relative to the lever 14, that is, along the elongated hole 14b provided in the lever 14 in the same direction as the main scanning direction of the carriage 4. ing. The cap 15 is provided with a hole 18 communicating from the print head 1 to the waste liquid case 19. The cap 15 can completely cover the nozzle 1a, and the space between the print head 1 and the cap 15 can be made airtight.

The ink discharged from the nozzle 1a passes through the cap 15 and is collected in the waste liquid case 19. The return of the lever 14 is performed by a lever return spring 17 whose other end is fixed to the frame 9.

FIG. 4, FIG. 5, and FIG. 6 are plan views showing the capping operation and the ink discharging operation. As shown in Figure 4,
When the carriage 4 moves to the right end in the figure, the lower end 14a of the lever 14 comes into contact with the carriage 4, and the lever 14 starts rotating counterclockwise about the bin 16. At this time, the cap 15 approaches the print head 1 at the same time. When the carriage 4 further moves to the right as shown in FIG. 5, the cap 15 approaches the head 1 further as the lever 14 rotates, and finally comes into contact with the print head 1.

When the carriage 4 further moves to the right, it becomes as shown in FIG. The cap 15 and waste liquid case 19 are attached to the lever 1.
The carriage 4 moves along the elongated hole 14b provided in the carriage 4. At this time, the piston 5 is moved in the direction of arrow C by the frame 9. As the piston 5 operates, the ink in the pump 3 is discharged from the nozzle 1a as described above, and air bubbles, dust, etc. in the head are removed. At the same time as the piston 5 operates, ink is filled from the ink tongue 2 into the rear side of the piston 5 inside the pump 3, as described above. The discharged ink passes through the cap 15 without leaking and is stored in the waste liquid case 19.

When the carriage 4 moves to the left, the cap 15 and the washing liquid case 19 move to the left together with the carriage 4. At the same time, the piston 5 is returned by the spring force of the return spring 6, and the ink in the pump 3 moves to the front side of the piston 5.

When the carriage 4 returns to the state shown in FIG. 5, the lever 14 begins to rotate clockwise due to the spring force of the lever return spring 17, and the cap 15 separates from the head 1.

Note that ink is not discharged every time the carriage returns to the home position, but only when it becomes impossible to eject ink from the nozzles. Furthermore, the amount of ink discharged at one time is set to the minimum that allows air bubbles and dust to be removed, so that ink consumption is kept to a minimum.

In this embodiment, the capping position is at the right end in FIG. 1, but it can also be installed at the left end by switching the orientations of the capping means and pump, and the positions of the head and ink tank. The structure of the pump does not have to be a piston type as in the embodiment, but may be a diaphragm type or the like.

[Effects of the Invention] As described above, according to the present invention, the ink ejection means is mounted on the carriage together with the print head, and the ejection means is operated by pressing against the frame of the inkjet recording device, and the capping position is set on the carriage. By disposing the ink at the moving end of the ink, the structure for discharging ink is extremely simplified compared to the conventional structure. - It has a function to easily restore a print head that has become unable to print without staining hands with ink, and is effective in downsizing and lowering the cost of inkjet recording apparatuses.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing one embodiment of the present invention. FIG. 2 is a sectional view showing the structure on the carriage of one embodiment of the present invention. Third
The figure is a perspective view showing details of a capping means according to an embodiment of the present invention. FIG. 4 is a plan view showing the capping means in operation, FIG. 5 is a plan view when the chapping operation is completed, and FIG. 6 is a plan view showing the discharge means in operation. FIG. 7 is a plan view showing a conventional example. 1...Print head 2...Ink tank 3...Pump 4...Carriage 5...Piston 14...Lever 15...Cap and above Applicant Seiko Epson Co., Ltd. Agent Patent attorney Suzuki Kisanbe and 1 other person

Claims (2)

[Claims] (1) In an inkjet recording device in which a carriage equipped with an inkjet head that ejects ink droplets from nozzles performs recording while moving in the main scanning direction, the printhead forming the nozzles and the ink in the printhead are combined. An inkjet recording apparatus comprising a discharge means for pressing and discharging the ink, and a capping means for receiving the discharged ink, and the print head and the discharge means are installed on the carriage. (2) The ejecting means operates by pressing a part of the ejecting means against the frame of the inkjet recording device, and the capping means is located at a moving end of the carriage. The inkjet recording device according to claim 1.