JPH05116330A - Ink jet recording apparatus - Google Patents

Abstract

PURPOSE:To prevent the inside of a cap from drying by sticking a cap cover to the cap, when a print head is operated. CONSTITUTION:A cap cover 1 having members 9 and 10 is attached to the upper end of a cap frame 4 so as to be movable. When a print head 13 is not operated, members 2 and 10 fixed to a cap frame support 6 hit frequently against each other so that the head cover 1 retreats to a position where a cap 3 and the print head 13 are not prevented from sticking to each other. When the print head 13 is operated, on the other hand, the cap 3 separates from the print head 13 and the members 2 and 9 hit frequently against each other so that the head cover 1 sticks to the cap 3 to intercept the contact of the inside of the cap 3 with the outside air.

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 Since the viscosity of ink in ink jet recording greatly changes with a change in temperature, it affects the amount of ink adhered to the nozzle surface of the print head and the ink drying time, which causes disturbance in recording quality. On the other hand, since the operating temperature of the inkjet recording apparatus is generally in a wide range of 0 ° C. to 40 ° C., a cap mechanism that is in close contact with the nozzle surface of the print head when the print head is not in operation is provided. This cap mechanism guarantees uniform recording quality by a cap operation that prevents excessive drying of the nozzle surface and a cleaning operation that sucks and removes the ink adhering to the nozzle surface and the ink inside the thickened head. There is.

[0003]

As described above, the cap mechanism is important in ink jet recording.
At the time of printing, the inside surface of the cap is kept open to the outside air, so if the printing is performed for a long time or the power is turned off during printing, the water inside the cap will continue to evaporate. , The cap is left in a very dry state. As a result, the ink remaining in the cap increases in viscosity, and the ink increased in viscosity due to the next cap operation adheres to the nozzle surface, causing deterioration of recording quality and, in the worst case, clogging of the nozzle. Further, there is a problem that the original function of the cap is impaired due to poor adhesion to the print head due to hardening of the cap.

The present invention eliminates the above-mentioned drawbacks and provides an ink jet recording apparatus having improved environmental resistance.

[0005]

On-demand type ink jet recording having a drive mechanism for ejecting ink droplets from a print head in response to a print command and a cap mechanism in close contact with the print head when the print head is not in operation. In the apparatus, the cap mechanism is provided with a cap cover that shields the cap when the print head is operating.

[0006]

According to the present invention, the inside of the cap can be prevented from being dried, and the thickening of the residual ink and the reattachment of the thickened ink to the nozzle surface can be avoided. Further, since the cap itself can be prevented from being hardened by drying, the function of the cap can be guaranteed for a long period of time.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments shown in the drawings will be described below.

FIG. 1 shows the structure of the cap mechanism in this embodiment.

The cap 3 is attached to the tip of the cap frame 4 and has a hole for the ink suction port 8. The ink suction port 8 communicates with the ink discharge tube 5 connected to the rear end of the cap frame 4. During the cleaning operation, the cap 3 comes into close contact with the nozzle surface of the print head 13, sucks ink from the ink suction port 8 and discharges it from the ink discharge tube 5. Cap frame 4
Has a single gear 14 and is attached to the cap frame support 6 by a cap frame attachment shaft 11. The cap frame 4 is rotated by the cap opening / closing motor 7 due to the engagement of the one-side gear 14 and the cap drive gear 15 to make a circular motion about the cap frame mounting shaft 11. Thereby, the opening / closing operation of the cap is performed. In order to improve the adhesion between the print head 13 and the cap cover 3, the cap 3 is made of an elastic material such as rubber.

The cap cover 1 has a member 9 and a member 10, and is attached to the upper end portion of the cap frame 4 by a cap cover mounting shaft 12, and the cap cover mounting shaft 12
A circular motion centered on is possible. The member 2 is fixed to the frame of the cap frame support 6. The members 9 and 10 of the cap cover 1 each contact the member 2 according to the opening / closing of the cap, and determine the position of the cap cover 1 according to the opening / closing of the cap.

The operation of this embodiment will be described below with reference to FIGS.

FIG. 2 shows a state in which the print head 13 is capped, that is, a state in which the print head 13 is in a non-operating state and a cap is closed during a cleaning operation. When the cap drive gear 15 rotates in the direction of arrow A, the single gear 14 rotates in the direction of arrow B. As a result, the cap frame 4 rotates about the cap frame mounting shaft 11, and the cap 3 comes into close contact with the print head 13.
At this time, the member 10 hits the member 2 so that the arrow C
Receives power in the direction of. Then, the cap cover 1 gradually rotates around the cap cover mounting shaft 12 in the direction of the arrow D, and is retracted to a position that does not prevent the cap 3 from closely contacting the print head 13.

FIG. 3 shows the state in which the cap is open, that is, the print head 13 is in the operating state. When the cap drive gear 15 rotates in the direction of arrow A ′, the one-side gear 14
Rotates in the direction of arrow B '. As a result, the cap frame 4 rotates about the cap frame mounting shaft 11,
The cap 3 is gradually separated from the print head 13. on the other hand,
The cap cover 1 gradually rotates in the direction of arrow D ′ depending on the contact between the member 10 and the member 2. When the cap frame 4 further rotates, the member 10 separates from the member 2,
The member 9 eventually hits the member 2. Member 9 is subjected to a force by member 2 in the direction of arrow C '. The cap cover 1 already in contact with the cap 3 further receives this force and further rotates in the direction of the arrow D ′ to come into close contact with the cap 3.

As described above, the cap cover 1 does not interfere with the operation of the print head 13 when the print head 13 is in close contact with the cap 3, and when the print head 13 is separated from the cap 3, the cap cover 1 is in close contact with the cap 3. The contact between the inside and the outside air is blocked to prevent the inner surface of the cap 3 from drying. Since the cap 3 is separated from the print head 13 and is shielded from the outside air by the cap cover 1 at the same time, the time when the inside of the cap 3 is in contact with the outside air is very short. Therefore, even if there is ink remaining inside the cap, the viscosity of the ink due to drying and the thickened ink will not redeposit on the nozzle surface.

Even if the power supply is cut off during printing, the cap cover 1 is always in close contact with the cap 3 during printing, so there is no fear of deterioration of the cap function due to hardening of the cap 3 due to excessive drying. ..

Further, since the operation of the cap cover 1 depends only on the opening / closing operation of the cap, no new electric signal or drive source is required, and the object can be achieved by simply adding a simple member to the conventional cap mechanism. It is possible to handle at low cost.

[0017]

As described above, according to the cap mechanism of the ink jet recording apparatus of the present invention, the cap 3 is separated from the print head 13 and, at the same time, is shielded from the outside air by the cap cover 1, and the inside of the cap 3 comes into contact with the outside air. Since the time is extremely short, even if there is ink remaining inside the cap, it is possible to improve the environmental resistance of the ink jet recording apparatus by preventing the ink viscosity from being dried and the thickened ink from re-adhering to the nozzle surface. ..

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the configuration of a cap mechanism of an inkjet recording apparatus of the present invention.

FIG. 2 is a structural diagram illustrating a state in which a cap is closed.

FIG. 3 is a structural diagram illustrating a state in which a cap is opened.

[Explanation of symbols]

 1 Cap Cover 2 Member 3 Cap 4 Cap Frame 5 Ink Discharge Tube 6 Cap Frame Support 7 Cap Opening / Closing Motor 8 Ink Suction Port 9 Member 10 Member 11 Cap Frame Mounting Shaft 12 Cap Cover Mounting Shaft 13 Print Head 14 Single Gear 15 Cap Drive gear

Claims (1)

[Claims] 1. An on-demand type ink jet recording apparatus having a drive mechanism for ejecting ink droplets from a print head in response to a print command and a cap mechanism that is in close contact with the print head when the print head is not in operation.
An ink jet recording apparatus, wherein the cap mechanism is provided with a cap cover that shields the cap when the print head is in operation.