JPH0970985A - Ink jet recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To conserve the consumption quantity of ink for restoring nozzle function used when printing inferiority is generated. SOLUTION: A nozzle restoring switch 15 and a changeover switch 20 changed over by opening and closing the unit lid of an ink tank unit are provided to a nozzle restoring circuit. When the nozzle restoring switch 15 is operated in such a state that the unit lid is closed when slight printing inferiority is generated, a head operating circuit Ch injecting restoring ink from a nozzle is selected by the operation control circuit 29 of a printing head and, when heavy printing inferiority is generated, the unit lid is opened to operate the nozzle restoring switch 15 and a pump driving circuit Cp driving a nozzle restoring pump 24 to forcibly discharge the restoring ink from a nozzle is selected. A nozzle function restoring means can be selected according to the degree of printing inferiority and the wasteful consumption of ink can be suppressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention prints characters, numbers and other marks (hereinafter referred to as "characters") indicating the manufacturer, the contents of the package, the quantity thereof, etc., on the lateral side of a cardboard box for packaging. The present invention relates to an ink jet type recording apparatus used for the.

[0002]

2. Description of the Related Art A conventional recording apparatus of this type is roughly divided into a head block for ejecting ink to a cardboard box and the like, and an ink tank unit for accommodating an ink tank for storing ink to be supplied to the head block. ,
An input device including a display device and a keyboard for inputting the output content of the print head, and a control unit for controlling the print head by an input signal from the input device are composed of four blocks.

In the above-mentioned ink jet recording apparatus,
When the print head nozzle is clogged or air bubbles are mixed in the nozzle and some or all of the nozzles become unprintable and printing defects occur, the ink is forcibly discharged from the nozzle and It has a nozzle function recovery means for recovering the function of. The function of the nozzle is recovered by operating the nozzle recovery switch to drive the nozzle recovery pump to forcibly eject the recovery ink from the nozzle.

[0004]

In the above-mentioned prior art, when printing failure occurs due to defective ink ejection, the nozzle recovery pump is always driven to eject the recovery ink from the nozzle. Functional recovery measures have been taken. Therefore, even if printing failure occurs due to the occurrence of a minor nozzle function failure that can be recovered by other simple operation, the nozzle recovery operation is performed by the nozzle recovery pump as in the case of severe printing failure. ing. The nozzle function recovery operation by driving the nozzle function recovery pump has a problem that the ink consumption is large and the running cost for printing is high.

Therefore, an object of the present invention is to divide the functional malfunction of nozzles that causes printing defects into minor ones and severe ones, and normalize the nozzles having the functional malfunctions by the nozzle recovery pump only in the case of serious malfunctions. It is possible to reduce the running cost of the ink jet recording device by recovering the function of the nozzle by the operation of the print head without relying on the nozzle recovery pump in the case of a slight failure. It is to plan.

[0006]

In order to achieve the above-mentioned object, the present invention is suitable for operating a nozzle recovery switch when a printing failure occurs in an ink jet recording apparatus according to the degree of the printing failure. It is characterized in that it is possible to reduce the consumption of the recovery ink for eliminating printing defects by selecting various ink discharging means.

Specifically, a nozzle recovery switch is provided for turning on / off a circuit for recovering the function of the nozzle by forcibly discharging the recovery ink from the nozzle when a printing failure occurs during printing. In addition, the ink tank unit has a head operation circuit that ejects recovery ink from the nozzles by driving the print head, and a pump drive circuit that compulsorily ejects the recovery ink from the nozzles by driving the nozzle recovery pump. A changeover switch for changing over is provided.

When the printing failure is slight, if the nozzle recovery switch is pressed while the unit cover of the ink tank unit is closed, the changeover switch causes the ink discharging function of the print head itself to operate and ejects the ink from the nozzle. Then, select the head operation circuit that eliminates the printing failure.

On the other hand, when the nozzle recovery switch is operated while the unit cover is open, the pump for recovering the ink is ejected from the print head by the nozzle recovery pump to eliminate the malfunction of the nozzle. Is selected.

When a serious printing defect occurs, the operator always opens the unit lid to check the remaining amount of ink in the ink tank, so that the head operating circuit and the pump driving circuit are selected. Is inevitable.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 7 shows a schematic structure of the present invention. This recording device prints on the lateral abdominal surface of a cardboard box B for packaging conveyed by a conveyor A without stopping the conveyance. As shown in the figure, the structure of the ink jet recording apparatus is roughly divided into the following four blocks.

The head block H, which is the first block
Is equipped with an inkjet print head 1 and has a drive signal correction circuit board mounted therein. The second block is an ink tank unit T containing an ink tank that supplies ink to the print head. The input device I in the third block is for inputting print contents, and includes a display 2 and a keyboard 3 for input. The fourth block is a control unit C for controlling the drive of the print head. The control unit C includes a drive circuit board for generating a drive signal and a signal for driving the print head, and a power supply circuit board. Other control circuit boards are mounted. The drive circuit board of the control unit C and the drive signal correction circuit board in the head block H are electrically connected by a conduit 4 of a bellows-shaped pipe having a flat cable therein. The drive signal generated by the drive circuit is corrected by the drive signal correction circuit board according to the characteristics of the print head 1 and supplied to the print head, and the print head is driven to eject ink from the nozzles. Is.

The head block H and the ink tank unit T are provided at the upper end of a support column 6 standing on the support base 5,
It is mounted on a mounting table 7 supported by a handle (not shown) so that its height and position can be adjusted.

An input device I including a keyboard 3 and a display device 2 and a control unit C including a floppy disk drive are mounted on a rack L with casters. The control unit C and the head block H are connected by a conduit 4 having a built-in flat cable, whereby the control circuit board in the control unit C and the print head 1 are connected.
Further, between the tank unit T and the head block H,
They are connected by a conduit 16 containing an ink tube 25 described later.

As shown in FIG. 3, the head block H is
A drive circuit board is provided in the box-shaped base 8 (not shown). This board includes a circuit for generating a drive signal for the print head. The conduit 4 described above is connected to the back side of the head block via a conduit connector 9. Although not shown, the flat cable housed in the conduit 4 is connected to the drive circuit board inside the box-shaped base 8, and the drive signal correction circuit board is connected to the tip of the drive circuit board. There is. The drive signal input from the drive circuit board is corrected to a signal corresponding to the characteristics of the print head and can be output to the print head 1.

On the lower surface of the base of the head block H, there is provided means 10 for rotating the print head, and the head block H is mounted on the mounting table 7 via this means 10 (see FIG. 7). ). The means 10 for rotating the print head comprises a bracket 11 for supporting the head block H.
Further, a rotation support plate 12 which is integrally rotatable with the box-shaped base 8 is swingably provided via a fulcrum pin 13.

FIG. 4 shows the state of the back side of the head block H. An arc-shaped guide groove 11a is provided on the back side of the bracket 11, and a rotation provided on the inner surface of the bracket from this guide groove. A fixing bolt 14 is screwed and fixed in a screw hole provided in the support plate 12 (see FIG. 3). The head block H can be fixed at a predetermined angle by inclining the head block H with an angle scale provided along the guide groove 11a as a guide and tightening the fixing bolt 14.

On the back side of the head block H, there is provided a push-type nozzle recovery switch 15 which is operated when the print head is defective in printing. Also here
A conduit 16 containing an ink tube for supplying ink from the conduit 4 and the ink tank unit T is connected via a conduit connector 17 (see FIG. 7).

As shown in FIGS. 1 and 2, the ink tank unit T is housed in a unit case 18. The unit case 18 is an openable and closable unit lid 1 that occupies about half of the base unit 18a and the unit case.
And 8b. The unit lid 18b is
The lower end is swingably connected to the base unit 18a via a hinge 18c. A switch pressing portion 19 is provided at the center of the end of the unit lid 18b.

A changeover switch 20 is provided inside the upper end of the unit case 18 at a position where the switch pressing portion 19 should be located when the unit cover 18b is closed. The changeover switch 20 is set so that the contact is opened and turned off when the unit lid is closed, and the contact is closed and turned on when the unit lid 18b is opened.

An ink reservoir 21 is fixed to the bottom of the unit case 18, and an ink tank 22 for storing ink for supplying ink to the print head is removably attached to the ink reservoir 21. A nozzle recovery pump 24 is provided on the side of the ink reservoir 21. The nozzle recovery pump 24 is driven by a motor 28 (shown in FIG. 5) described later, and has a function of forcibly discharging recovery ink from the print head when a printing failure occurs.

Ink supply hole 21a of ink reservoir 21
Is an ink tube 25 that constitutes an inlet pipe.
Is connected to one end and the other end is connected to a nozzle recovery pump 24. The nozzle recovery pump 24 is further connected to one end of an ink tube 26 as an outlet pipe. The outlet pipe 26 extends downward from the bottom of the unit case 18. Outgoing pipe 26
The outer portion of the unit case is protected by a conduit 16 which is a bellows-shaped protection tube. The other end of the conduit 16 that protects the outlet pipe 26 is connected to the head block H described above, and the recovery ink can be forcibly discharged from the print head 1 by the nozzle recovery pump 24 ( (See FIG. 7).

FIG. 5 shows the circuit configuration of the control unit of the nozzle recovery means of the present invention, in which the motor power supply 27 and the drive motor 28 of the nozzle recovery pump 24 are connected in series, and this series circuit is connected. A nozzle recovery switch 15 and a changeover switch 20 are provided. In addition, the nozzle recovery switch 15
A circuit for outputting a signal generated by the ON / OFF state of the changeover switch to the control circuit 29 for controlling the print head is connected between the switch 20 and the changeover switch 20. In this circuit, when the changeover switch 20 is turned on and the nozzle recovery switch 15 is pressed, a pump drive circuit Cp that connects the power source 27 and the motor 28 is configured, and the motor 28 becomes rotatable. The nozzle recovery pump 24 is driven by the rotation of the motor 28, and the recovery ink can be forcibly discharged from the print head. At this time, the control circuit 29 is set so as not to operate. In contrast,
When the changeover switch 20 is turned off and the nozzle recovery switch 15 is pressed, a head operation circuit Ch for operating the print head control circuit 29 is constructed. When the head operation circuit Ch is closed, the recovery ink is not discharged from the nozzle recovery pump 24, and the piezoelectric element of the print head operates to forcibly discharge the ink in the ink flow path as the recovery ink. Is.

[0024]

[Operation] First, the height of the head block H is adjusted by a height adjusting screw (not shown), and the head surface of the print head 1 is set so as to maintain a predetermined distance from the cardboard print surface, thereby preparing to start printing. do. The print contents are input by the keyboard 3 of the input device I, and the print contents are input.
And the output contents are edited, and then characters are output and printed by ejecting ink from the print head 1 from the control unit C through the cable housed in the conduit 4 (see FIG. 7).

When a printing failure occurs during printing, the degree of the printing failure is judged, and when the printing failure is judged to be slight, the nozzle recovery switch 15 is immediately pushed (see FIGS. 3 and 4). ). Then, the head operation circuit Ch is closed and the print head 1 is operated to forcibly discharge the recovery ink from the nozzles (see FIG. 5). This operation facilitates the operation for recovering the function of the nozzle, and has an advantage that the consumption of the recovery ink is extremely small. Here, the slight printing failure corresponds specifically to printing failure due to thickening of ink in the nozzle portion, which is likely to occur when the apparatus is left unused for a long time, or intrusion of minute bubbles. .

On the other hand, when it is judged that the degree of printing failure such as printing failure is severe, first, the unit lid 1
8b is opened (see FIG. 1), and the presence or absence of ink in the ink tank 22 is confirmed. At this time, since the unit cover 18b is open, the changeover switch 20 is turned on. When the ink in the ink tank 22 is exhausted, the nozzle recovery switch 15
When is pressed, the pump drive circuit Cp is closed, and the recovery ink is forcibly discharged from the print head 1 by the nozzle recovery pump 24 to eliminate the cause of defective printing. of course,
When ink remains in the ink tank 22, the nozzle recovery switch 15 is pressed immediately, and similarly the recovery ink is forcibly discharged by the nozzle recovery pump 24.

When the recovery ink is forcibly discharged from the print head 1 to discharge dust adhering to the inside and outside of the nozzle, the operator puts a sheet on the front surface of the head,
A print pattern composed of N characters as shown in FIG. 6 is formed, and the recovery state of the nozzle function is determined. When it is determined that the functional recovery of the nozzles is insufficient, it is necessary to further force the recovery ink to be discharged. When it is determined that the nozzle function is sufficiently restored, the printing operation is restarted. Although the letter “N” is used as the above-mentioned print pattern, the print pattern is not limited to this and other patterns may be used.

Although a contact-type switch is used as the changeover switch 20 here, the invention is not limited to this. For example, a magnet is provided on the unit lid,
A magnetic sensor that responds to this may be used.

[0029]

According to the present invention, when the nozzle recovery switch is operated, ink is ejected from the nozzles by the operation of the print head when the unit lid is closed, and when the unit lid is open, Since the nozzle recovery pump forcibly discharges ink from the nozzles of the print head, it is easy to select the nozzle recovery function according to the weight of print defects, and the consumption of recovery ink is reduced by selecting the appropriate function. It has a terrifying effect. Further, when the recovery ink is forcibly discharged by the nozzle recovery pump, the ink may be consumed during operation because the ink consumption is large. However, in the present invention, unless the ink tank unit lid is open. Since the nozzle recovery pump is not operated, a large amount of recovery ink is not forcibly discharged by the nozzle recovery pump despite a slight printing defect. Furthermore, in the case of severe printing failure, the nozzle recovery switch is operated after opening the unit lid, so it is possible to constantly monitor the remaining amount of ink in the ink tank, and it is likely that the ink will be used up. It is possible to prevent unexpected accidents.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a state in which a unit lid of an ink tank unit of the present invention is opened.

FIG. 2 is a partially cutaway front view of the ink tank unit of the present invention.

FIG. 3 is a side view of the head block of the present invention.

FIG. 4 is a rear view of the head block of the present invention.

FIG. 5 is a circuit configuration diagram of a pump control unit of the present invention.

FIG. 6 is a pattern diagram showing an ink ejection pattern.

FIG. 7 is a perspective view showing the overall configuration of the present invention.

[Explanation of symbols]

 H head block T ink tank unit 1 print head 15 nozzle recovery switch 18b unit lid 20 changeover switch 22 ink tank 24 nozzle recovery pump Ch head operation circuit Cp pump drive circuit

Claims (1)

[Claims] 1. A head block equipped with an ink jet print head, an ink tank unit containing an ink tank for storing ink to be supplied to the print head, and an ink in the ink tank when a printing failure occurs. A nozzle recovery pump for sending the ink to the print head to recover the function of the nozzle of the print head, and a circuit for recovering the function of the nozzle by forcibly discharging the recovery ink from the nozzle when a print failure occurs. An ink jet recording apparatus having a nozzle recovery switch for turning on / off a head operation circuit for ejecting the recovery ink from the nozzles by driving the print head, and the nozzle recovery switch in the ink tank unit. The recovery ink is forcibly forced from the nozzle by driving the recovery pump. There is a changeover switch for switching to the pump drive circuit to be discharged, and when the nozzle recovery switch is operated, the changeover switch selects the head operation circuit when the unit lid of the ink tank unit is in the closed state. An ink jet recording apparatus, wherein the pump drive circuit is set to be selected when the unit cover is in an open state.