JP2911787B2 - Automatic ink supply device for inkjet printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic ink supply device for an ink jet printer which automatically supplies ink to a print head of the ink jet printer.

[0002]

2. Description of the Related Art As a conventional automatic ink supply device for an ink jet printer, as disclosed in Japanese Patent Application Laid-Open No. 7-17046, when an ink remaining amount in a print head becomes a predetermined amount or less, the ink supply device is attached to the print head. The ink 13 is supplied by operating the pump 5 based on the detection signal of the remaining ink amount detection unit. That is, FIG. 5 is a configuration diagram of the conventional print head.

[0003]

However, as shown in FIG. 5, the discharge tube 7a is only connected to the ink supply port 9 of the print head 3, and when the pump 5 operates, the ink 13 vigorously flows. In some cases, the ink 13 jumped out and foamed in the print head 3. In addition, it is necessary to make a hole for venting the ink supply port 9 of the print head 3 so that the pressure discharged from the pump 5 is not applied to the inside of the print head 3. For this reason, while the pump is stopped, the ink remaining between the discharge side tubes 7a coming out of the pump outlet has a water head, and flows out into the print head 3 as time elapses. The air enters. Then pump 5
When the operation is performed, the air in the discharge side tube 7a blows out first, and the ink 13 remaining in the print head 3 is scattered, which causes foaming. SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and its purpose is to reduce a printing defect in which a mixture of air and ink due to bubbles enters an ink jet generation unit at the time of printing, and this air causes an unprintable portion to be generated. An object of the present invention is to provide an automatic ink supply device for an ink jet printer to be solved.

[0004]

In order to achieve the object, a discharge tube for supplying ink from the pump outlet to the print head is inserted into the print head through the ink supply port of the print head. In addition, a backflow prevention device for preventing backflow, for example, a device having a diode structure, is added to the end of the printhead so as to eliminate the generation of bubbles which may cause printing defects in the print head.

[0005]

The operation will be described in conjunction with the embodiment described below.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. 1 is an overall configuration diagram for explaining the present invention, FIG. 2 is a main portion configuration diagram showing one embodiment of the present invention, and FIGS. 3 and 4 are explanatory diagrams for explaining the function of a diode. 1 and 2, reference numeral 1 denotes a body of the printer, in which a platen roller 11 rotatably supported in the body 1 in cooperation with a rotary driving device, and inside the body 1 in parallel with the platen roller 11. And the rail 2
And a carriage 4 that can move along. Then, the ink jet type print head 3 mounted on the carriage 4 and the printing unit faces the platen roller 11 is
The print head 3 is mounted on the paper 10 guided on the surface of the platen roller 11 so as to perform printing by the print unit of the print head 3 while moving along the platen roller 11. In the present invention, a replenishing ink tank 6 containing ink as shown in FIG. 2 and a pump 5 for feeding ink from the replenishing ink tank 6 into the print head 3 are mounted on the carriage 4 as shown in FIG. The tank 6 and the ink head 3 are connected to a tube 7 through a pump 5, and a detector attached to the print head 3 when the amount of ink in the print head 3 becomes a predetermined amount or less during printing, that is, an ink remaining amount detecting unit The pump 5 operates based on the detection signal of 8, and the ink in the replenishment ink tank 6 is supplied into the print head 3 by an amount controlled by the controller of the printer (not shown), and printing is continued.

In FIG. 2, the discharge side tube 7 a penetrating the ink supply port 9 is located near the bottom of the ink reservoir of the print head 3, that is, below the upper surface of the ink when the ink remaining amount detecting unit 8 detects out of ink. I will extend it. FIG. 3 shows a state in which the pressure-applied ink flows out of the pump, that is, a state in which the pump pressure is reduced by the diode 12, thereby preventing the ejection state and the drop discharge state. FIG. 4 is a view in which a diode 12 for preventing backflow is attached to the end of the discharge tube 7 and shows a state where the operation of the pump is stopped. And backflow are prevented. The diode 12 has the same function as a fluid blocking diode using elasticity.

[0008]

As described above, according to the present invention, the replenishment ink tank 6 and the print head 3 are connected by the discharge side tube 7a and the suction side tube 7b through the pump 5, so that the inside of the print head 3 When the remaining amount of the ink 13 becomes a certain amount or less, the pump 5 operates based on the detection signal of the ink remaining amount detecting unit 8 attached to the print head 3, and the ink 13 in the replenishing ink tank 6 When an amount controlled by the controller unit is supplied into the print head 3 through the discharge side tube 7, the action of reducing the ink supply pressure into the print head 3 due to the decompression effect of the diode causes the inside of the print head 3 to decrease. In addition to preventing the bubbling of the ink 13, the entry of air into the tubes 7 a and 7 b due to the water head causing the bubbling also occurs due to the decompression effect of the diode 12. Prevents leakage of cube 7a of the ink 13, and has an excellent effect that air discharged to maintain without satisfactory printing. Also, in the present invention, an example in which the diode 12 is added to the tip of the discharge side tube 7 has been described. However, if a tube material having elasticity is used, for example, by using a material which is thermally deformed, a round tube can be flattened by heat. Needless to say, this also has the same effect. Further, in the present embodiment, the platen type medium feeding device for printing has been described. However, flat printing, that is, a device in which the head moves up and down in addition to the left and right operation, has the same effect. It is.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram for explaining the present invention.

FIG. 2 is a main part configuration diagram showing one embodiment of the present invention.

FIG. 3 is an explanatory diagram showing an ink supply state.

FIG. 4 is an explanatory diagram illustrating a state in which ink supply is stopped.

FIG. 5 is an explanatory diagram showing an example of the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Body 2 Rail 3 Print head 4 Carriage 5 Pump 6 Refill ink tank 7a Discharge side tube 7b Suction side tube 8 Ink remaining amount detection part 9 Ink supply port 10 Paper 11 Platen roller 12 Diode 13 Ink

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-8400 (JP, A) JP-A-7-17046 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B41J 2/175

Claims (1)

(57) [Claims] 1. A platen roller rotatably supported by a body in cooperation with a rotary drive device, a rail disposed on the body in parallel with the platen roller, and a carriage movable along the rail. A print head for performing printing by a print unit of a print head while moving along the platen roller on a sheet facing the platen roller and guided on the surface of the platen roller, and an ink for the print head. And a pump for feeding ink from the replenishing ink tank into the print head, and a detector for detecting the remaining amount of ink, are mounted between the replenishing ink tank and the print head via a pump. When the remaining amount of ink in the print head falls below a certain amount, the detector operates to output a detection signal of the remaining amount of ink. At least the pump is operated, and the ink is supplied from the pump to the print head in the ink jet printer automatic ink supply device in which the ink is supplied from the replenishment ink tank into the print head by an amount controlled by the controller of the ink jet printer. A tube extends through an ink supply port of the print head, and a diode is provided at a tip end thereof as a backflow prevention device for preventing backflow of ink, that is, intrusion of air.The diode is located near the bottom of the ink reservoir of the printhead, An automatic ink supply device for an ink jet printer, wherein the ink supply device is provided at an end of a discharge side tube extending below the upper surface of the ink when an out-of-ink state is detected by an ink remaining amount detection unit.