JP2870838B2 - Inkjet head protection mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a print head protection mechanism in an ink jet printer, and more specifically, to prevent ink at the tip of a head nozzle from drying out and discharge air bubbles that have entered the nozzle. Regarding the mechanism.

[Conventional technology]

In recent years, with the spread of office automation, there has been an increasing demand for creating and printing documents in offices, and there has been a demand for a printer with low noise and good printing quality. Also, with the spread of personal computers, there is an increasing demand for outputting characters and graphics on a color display in color. In recent years, ink jet kanji printers and ink jet color printers have been put to practical use as printers satisfying these requirements.

Conventionally, this type of printer forms a nozzle unit, an ink pressurizing chamber, and an ink supply unit on the surface of a glass plate or a metal plate by using a technique such as photoetching. The ink pressurizing chamber is pressurized by the bending deformation of the nozzle, and an ink droplet is ejected from the nozzle tip.

In such an ink jet head, when ink droplets are not ejected for a long time, the ink passage at the nozzle end face is blocked, and it is often impossible to eject ink droplets. To prevent this ink evaporation and solidification, when printing is not performed, the nozzle end face is dipped in water, sealed in a small chamber filled with water vapor, and the nozzle end face is pressed with a flexible member such as rubber. A method of completely shutting off the ink and the air has been taken. Also, while ejecting ink from the nozzle end surface, due to pressure fluctuation due to some disturbance applied to the ink, bubbles are sucked from the nozzle end surface,
Often, the residual air in the ink penetrates into the nozzle and disables the ejection of the ink.

[Problems to be solved by the invention]

In the above method, a container for storing water or steam and a work for periodically replenishing the water are required, or when air bubbles are sucked into the nozzle, it is necessary to return the device to the maker and remove the air bubbles, It was a very unreliable printer.

[Means for solving the problem]

In order to solve the above problem, the ink jet protection mechanism according to the present invention forcibly ejects ink from the nozzle cap of the ink jet head, which is opposed to the retreat position of the ink jet head when printing is not performed, and is filled with ink vapor. An ink pressurizing pump for discharging and an ink discharging pump for performing a discharge ink collecting operation after the operation of the ink pressurizing pump are provided.

〔Example〕

 Next, the present invention will be described with reference to the drawings.

FIG. 1 shows an inkjet head protection mechanism according to the present invention. FIG. 2 is a diagram showing the configuration of an apparatus according to the present invention.
The ink jet printer is mounted on a carrier 3 so that the ink jet 1 can be scanned by guiding the guide shaft 2 along the platen 18 in order to print on the printing paper 17 wound around the platen 18. On the carrier 3, a small sub-tank is integrated with the inkjet head 1.
19 is provided, and is frozen by a pipe via an ink pressurizing pump 15 to an ink cartridge 4 fixed at an arbitrary position in the apparatus. When the ink jet head 1 does not perform printing, the carrier 3 is moved along the guide shaft 2 to the ink jet head retreat position, that is, the printing area and the head cap mechanism installation position which is off the side end of the platen 18.
Moves and is closed by the head cap 6 of the head cap mechanism 20 as shown in FIG. Head cap 6
The inside is filled with vapor due to the evaporation of discharged ink absorbed in the felt 10 in the cap tank 14 to prevent the ink on the end face of the head nozzle from drying. Further, when the apparatus power is turned on, and every time a predetermined time elapses, or when air bubbles enter the head nozzle, the ink pressurizing pump 15 is operated while the ink jet head 1 is capped,
The ink containing bubbles is forcibly ejected from the nozzle nozzle end face from inside the nozzle, and flows into the head cap 6. The discharged ink flowing into the head cap 6 is absorbed by the felt 10 in the cap tank 14 through the rubber tube 8. In addition, a part of the ejected ink, the ink flowing along the nozzle end surface is absorbed by the absorbing material 13. After the operation of the ink pressurizing pump 15, the ink discharge pump 9 is operated to collect a part of the discharged ink absorbed by the absorbing material 13 into the discharged ink recovery tank 5 through the discharged ink recovery pipe 16. In addition, the overflowing ink that cannot be absorbed by the felt 10 in the cap tank 14 and overflows through the absorbing material 11 of the branch pipe 12 provided in a part of the waste ink collecting pipe 16 when the ink discharging pump operates. Collected in 5. Therefore, in the cap tank 14, the felt 10 is always kept in a state where 100% ink is absorbed by the operation of the ink pressurizing pump and the ink discharging pump.

〔The invention's effect〕

As described above, according to the present invention, by operating the inkjet head protection mechanism periodically, the inside of the head cap is always kept at a high humidity to prevent the ink from drying on the end face of the inkjet head nozzle, and the air bubbles always flow in the inkjet head nozzle. To achieve a highly reliable printer.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the ink jet head protection mechanism of the present invention, and FIG. 2 shows a schematic view of the device mounting of the present invention. 1 ... inkjet head, 2 ... guide shaft,
3. Carrier 4, Ink cartridge 5, Ink collection tank 6, Head cap 7, Seal rubber 8, Rubber tube 9, Ink discharge pump 10,
... Felt, 11 ... Absorbent, 12 ... Branch pipe, 13 ...
Absorbent material, 14 Cap tank, 15 Ink pressure pump, 16 Ink collection pipe, 17 Printing paper, 18
... platen, 19 ... sub tank, 20 ... head cap mechanism.

Claims (2)

(57) [Claims] A head cap which is filled with ink vapor and faces an evacuation position of the ink jet head when printing is not performed; an ink pressurizing pump for forcibly discharging ink from nozzles of the ink jet head; An ink jet head protection mechanism comprising: an ink discharge pump that performs a discharge ink recovery operation after a pressure pump operation. 2. The head cap according to claim 1, further comprising: a cap tank having a first absorbent for absorbing the discharged ink and a second absorbent for absorbing ink overflowing from the first absorbent. And a third absorbing material that absorbs a part of the discharged ink, and wherein the ink discharge pump collects ink from the second absorbing material and the third absorbing material. 2. The inkjet head protection mechanism according to 1.