JPS6048360A - Ink jet printer - Google Patents

Abstract

PURPOSE:To reduce the consumption of ink required in releasing non-emission of ink, by constituting the titled printer so that a plurality of ink jet nozzles are divided into plural blocks and the ink restoration of each block can be independently controlled. CONSTITUTION:Ink jet nozzle groups Y, M, C are respectively divided into plural blocks in the width direction of recording paper P and solenoid valves V1-Vn are driven by plungers PL1-PLn to perform the ON/OFF control of ink continuity and each block is independently controlled with respect to ink restoration. The release operation of non-emission of ink from each ink jet nozzle is performed only to the corresponding nozzle block to reduce ink wastefulness.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an inkjet printer, and more particularly to an operation for resolving inkjet nozzle failure and returning the nozzle to a normal state.

[Prior Art] In an inkjet printer, a recording paper is run facing a plurality of inkjet nozzles, and ink is intermittently ejected from the nozzles. At this time, the inkjet is turned on and off from each nozzle. By appropriately selecting the dots at the appropriate times, characters and other patterns made up of a large number of dots are printed on the recording paper. Turn on ink ejection from the nozzle in such an inkjet printer.

The OFF control is performed using conventional electro-mechanical means so that a predetermined pattern is printed.

The nozzles may be arranged in one row covering a predetermined IJ of the recording paper, but recently they are also arranged in two or more rows to improve printing speed. In addition, for color printing, inkjet nozzles for multiple primary colors (usually three primary colors) are arranged in multiple rows, with one row for each color, and one dot on the recording paper is printed according to the mixing ratio of the primary color inks from the nozzles in each row. It is also practiced to form it in a desired color.

Incidentally, the inkjet nozzle often has dust attached to its tip or air bubbles entering from the tip, so that ink is not ejected even though the ink ejection signal is ON.

In this case, printing will be defective, so it is necessary to immediately resolve the ink ejection failure. In conventional inkjet printers, in such cases, the ejection signals of all nozzles are turned ON to simultaneously push out ink or suck ink to the recording paper side, thereby removing dust or air bubbles from the non-ejecting nozzles, and then Printing later resumed. Therefore, there are problems such as a considerable amount of ink being wasted and the frequency of ink replenishment increasing. This is a big problem, especially in high-speed printers and color printers that have a large number of inkjet nozzles.

[Object of the present invention] In view of the above-mentioned prior art, it is an object of the present invention to reduce ink consumption as much as possible when resolving ink non-discharge from a nozzle in an inkjet printer.

[Embodiment of the present invention] FIG. 1 is a tthm diagram of a color inkjet printer which is an embodiment of the inkjet printer of the present invention. The recording paper is made to travel from inside the main body exterior OC to the outside through the exit PO in the direction of the arrow. Printing is performed on the recording paper P by an inkjet before it exits from the outlet PO.

FIG. 2 is a perspective view showing an example of the internal mechanism of the color inkjet printer according to the present invention.

Note that, in this figure, a mechanism for controlling ON/OFF of ink discharge from an inkjet nozzle in order to form a predetermined printing pattern is omitted.

The inkjet nozzle consists of three groups, Y, M, and C, and each group is for ejecting ink of a mutually different color among the three primary colors. These three nozzle groups are vertically fixed at appropriate distances and fixed in parallel.

The inkjet nozzle group Y includes a plurality of blocks Y1 to Yn.
Each block is removably fixed onto the plate l- with screws or the like (not shown). Each block has a plurality of nozzles arranged in a row in the horizontal direction, and all blocks are arranged in the running direction (up and down direction) of the recording paper P.
The nozzles are positioned so as to correspond one by one to the dot positions that cover the maximum recording IJL of the recording paper when viewed from above.

When fixing the nozzle block to Play) 1, it is necessary to assemble it with the adjacent block, and it is also necessary to adjust the nozzle spacing between the blocks, so there must be a dimensional margin between the blocks. is required. Therefore, every other nozzle block is arranged upside down (staggered) with respect to the plate 1.

One end of tubes T1 to Tn for supplying ink is connected to the nozzle blocks Y1 to Yn, respectively. Solenoid valves v1 to Vn are provided at the other ends of the tubes T1 to Tn, respectively.
is connected. These solenoid valves Vl-Vn each have tubes Tut-Tu for supplying ink to the valves.
One end of n is connected. The solenoid valves Vl-Vn are driven by plungers P L 1- P L n, respectively, and are connected from the tube Tut-Tun to the tube Tl.
- ON/OFF control of ink conduction to Tn.

The other ends of tubes Tul to Tun are all tube connectors T.
Therefore, the tubes Tul-Tun are all in communication. One end of the tube TB is connected to the tube coupler TC so as to be electrically connected to the tubes Tul to Tun. There is a conduction needle N at the other end of the tube TB.
l is attached. Needle N1 is ink tank I
Connected to T.

FIG. 3 is a schematic cross-sectional view of the ink tank IT. An ink bag MT made of a flexible material is housed inside the ink tank IT, and a rubber stopper R1 is attached to the opening of the ink bag MT. A rubber stopper R1 is attached to the wall of the ink tank, and a needle N1 attached to the tip of the tube TB is pierced into the rubber stopper R1. This brings the tube TB into electrical continuity with the ink bag MT. Of course, by pulling out the needle N1, the conductive state is canceled, and the rubber stopper R1 restores its shape due to its elasticity, the needle puncture hole is closed, and the ink bag MT is sealed. A rubber stopper R2 similar to the rubber stopper R1 is also provided in the ink tank IT. however,
The rubber stopper R2 is in contact not with the ink bag but with the space outside the ink bag inside the ink tank IT.

A conductive needle N2 similar to the needle Nl is pierced through the rubber stopper R2 in the same manner as the needle Nl, and the needle N2 is attached to one end of the tube FT. At the other end of the tube FT is an air pump P.
u is connected, and air can be forced into the ink tank IT and outside the ink bag MT through the tube FT and needle N2 by driving the pump Pu. A hole H is also provided on the wall of the ink tank IT. A plunger PG is arranged close to the ink tank IT at a position facing this hole H, and a rubber member PR is fixed to the tip of the plunger PG. can close hole H.

Although the inkjet nozzle group Y has been described above, the same applies to the nozzle groups M and C.

As shown in FIG. 1, marks B1 to Bn are attached to the front edge of the recording paper outlet PO of the exterior OC to divide the maximum recording area of the recording paper P into n blocks. This mark corresponds to inkjet nozzle pro Y1 to Yn. That is, the portion P1 of the recording paper P to which ink is applied by the nozzle block Yl is always at the outlet PO →
In the same manner, the portion Pn to which ink is applied by the nozzle block Yn always runs within the block specified by the mark Bn at the exit PO. Although not shown, the nozzle blocks Ml-Mn and CI-Cn of the inkjet nozzle groups M and C have exactly the same correspondence.

FIG. 4 is a diagram showing an example of the logic for canceling ink non-discharge in the printer of the present invention.

When ink failure occurs in a certain nozzle during printing, that is, ink is not ejected from the nozzle even though the ink ejection ON command has been issued to the nozzle, for example, nozzle group Y
When non-ejection occurs in the nozzles belonging to the nozzle block Yl, a printing defect occurs in a specific dot row DL along the recording paper running direction on the portion tl of the recording paper P coming out from the recording paper outlet PO. This dot row may be missing or the color tone may be completely different. If such a printing defect occurs, press Y of the color key group C5 corresponding to the three primary colors YlM and C provided on the main body exterior OC, and then press the blocks B1 to Bn provided on the main body exterior 9C. Press B1 of block key group S corresponding to .

As a result, in FIG. 4, flip-flops FY and Fl are set and F2 to Fn are not set, so F
The signal 1 passes through the OR gate OR, opens the AND gate A, and the OS is activated. As a result, the plunger PG is driven, and the hole H of the ink tank IT is closed by the rubber member PR.
At the same time, the air pump Pu is driven, and the pressure inside the ink tank IT increases. On the other hand, the signals from flip-flops F1 to Fn are NAND groups NAI to NAn.
Through the action of the two AND groups A1 to An and ADI to ADn, only PLI of the plungers PLI to PLn is transmitted so as to operate <PL2 to PLn, which closes the solenoid valves v2 to Vn. Vl remains open.

Therefore, the ink in the ink bag MT is forced out through the tube TB and the tube coupler TC, the tube Tu 1
．． Nozzle block Y via solenoid valve ■1 and tube T1
The ink is supplied into the gutter GY and pushed out from all the nozzles of the block Y1, and the pushed out ink flows through the gutter GY and is collected in one place. This state continues until the flip-flop is reset. As a result, the non-discharge of ink from the non-discharge nozzle is canceled.

In addition, although only Y is shown as a color key in FIG. 4, M and C are also connected in the same way as Y, so even if a nozzle belonging to inkjet nozzle block M or C fails to eject ink, Non-discharge can be canceled in the same way.

Although a color inkjet printer has been specifically described above, it is clear that ink non-discharge can be canceled in the same manner for a monochrome inkjet printer.

[Effects of the Present Invention] According to the present invention as described above, since the operation for canceling the ink jet nozzle's ink failure is performed only for the corresponding nozzle block, it is more effective in eliminating the ink failure than when it is performed for all nozzles. Ejection can be canceled, less ink is wasted, and ink does not need to be replaced as frequently.

[Brief explanation of the drawing]

Fig. 1 is an external view of a color inkjet printer according to the present invention, Fig. 2 is a perspective view of its internal mechanism, Fig. 3 is a sectional view of its ink tank, and Fig. 4 is an ink non-discharge release release. FIG. l Nibrate P: Recording paper OC: Main body exterior PO: Recording paper outlet B1 to Bn: Mark C3: Color key 1 group S Nib block key 1 group Y, M, C: Nozzle group Yl-Yn: Nozzle block GY, GM, GC nigator Tl to Tn , Tul-Tun, TB, PT: Tube V1~■n: Solenoid valve PL 1~PLn, PG Nib lunger Nl, N
2: Conduction button Pu: Air pump PR: Rubber member H:
Hole hole T: Ink tank MT: Ink bag R1, R2: Rubber stopper Figure 1

Claims (3)

[Claims] (1) In an inkjet printer that performs inkjet printing on a predetermined width of the recording paper using multiple inkjet nozzles while running the recording paper in one direction, the multiple inkjet nozzles print on multiple blocks in the 11] direction of the recording paper. It is characterized in that it is divided into sections, and each block is configured so that ink recovery can be controlled independently. inkjet printer. (2) The inkjet printer according to item 1, wherein the inkjet nozzle blocks are configured separately, and each block is removably fixed to an appropriate member. (3) Item 1, wherein each inkjet nozzle block is connected to an ink supply source by a tube, and a valve is interposed in the middle of the tube, and the ink flow to the nozzle block can be controlled by the valve. Inkje End Printer.