JPH0880606A - Ink jet printer - Google Patents

Abstract

PURPOSE: To obtain a high-reliability printer having no possibility that a circuit board may be contaminated with ink or brought into contact with an ink tube. CONSTITUTION: An ink jet printing head 16 is provided on a head block 1. An ink tube 82 is connected to the rear part of the printing head. A drive signal correction circuit board 14 correcting a head drive signal correspondingly to the characteristics of the printing head and supplying the same to the printing head is provided rearward of the printing head. A front cover 17 covering only the printing head except a nozzle surface 16b thereof is detachably provided on the head block 1. A rear cover 15 covering the drive signal correction circuit board 14 and the ink tube 82 is fixedly provided. A packing member 18 is provided between the front cover 17 and the printing head 16 around the nozzle surface 16b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a physical distribution transport system, etc., for example, on the flank of a cardboard box for packaging, characters, numbers and other marks or symbols indicating the manufacturer, the contents of the package, the quantity thereof, etc. The present invention relates to an inkjet printing device used for printing.

[0002]

2. Description of the Related Art Conventionally, a printing apparatus of this type is roughly divided into four blocks, and a head block of the first block is equipped with an ink jet type print head and has a drive signal correction board mounted thereon. The second block is an ink tank unit having an ink tank for supplying ink to the print head, and the input terminal of the third block is for inputting print contents. And a keyboard for inputting, and the fourth block is a control unit for controlling the drive of the print head. In this unit, a drive circuit board for generating a drive signal and a signal for driving the print head is provided. Also, a power supply circuit board and other control circuit boards are mounted. The drive circuit board of the control unit and the drive signal correction circuit board in the head block are electrically connected by a conduit of a bellows pipe having a flat cable inside, and the drive circuit generated by this drive circuit is connected. The signal is corrected by the drive signal correction circuit board according to the characteristics of the print head and supplied to the print head, and the print head is driven.

Conventionally, as shown in FIGS. 11 and 12, an outer cover a is detachably provided on the head block. When the outer cover a is removed, the ink jet type print head inside the head block is removed. The circuit portion c such as b, the drive signal correction circuit board, and the ink tube d are entirely exposed. The case where it is necessary to remove the outer cover a is a case where air bubbles are generated or remain in the flow path of the print head b and printing cannot be performed due to the air bubbles. In that case, the head vent cap e is removed. The ink is opened and pushed out from the ink tank unit to remove air bubbles. In addition, the ink may be pushed out from the nozzle using a normal pump without removing the outer cover a.

[0004]

By the way, the head vent cap e is opened with the outer cover a removed,
When the internal ink is pushed out from the ink tank unit to remove bubbles and the like, there is a problem that a large amount of ink flows out and the exposed circuit board c is stained with the ink. Further, when the ink is pushed out from the nozzles using the pump without removing the outer cover a, the ink enters the head block through the gap between the print head b and the outer cover a, so that the outer cover a is frequently removed. It is necessary to remove and print the print head b to perform a cleaning operation. During this operation, the ink tube d is touched and the circuit board portion c is soiled, which also causes a failure.

SUMMARY OF THE INVENTION An object of the present invention is to provide a highly reliable ink jet printing apparatus which does not stain a circuit board portion with ink or touch an ink tube.

[0006]

In order to achieve the above object, a printing apparatus of the present invention is equipped with an ink jet type print head in which an ink tube for ink supply is connected to a rear portion, and the print head is provided behind the print head. The head block has at least a drive signal correction circuit board for correcting the drive signal of the print head according to the characteristics of the print head and supplying the drive signal to the print head. In this head block, only the print head is provided. A front cover that covers except the nozzle surface is detachably provided, and a rear cover that covers at least the drive signal correction circuit board and the ink tube is fixedly provided.

It is preferable that a packing member located around the nozzle surface is interposed between the front cover and the print head.

[0008]

An embodiment of the present invention will be described with reference to the drawings. A schematic configuration is shown in FIG.
Is supported by a support base 2 so that its position can be adjusted in the height and the moving direction. That is, the vertical column 21 is attached to the support base 2 by the handle 22.
Is supported so as to be movable up and down, and a horizontal plate 24 is supported by a mounting member 23 fixed to this vertical column, and the head block 1 can move forward and backward and rotate at the rear end of the horizontal plate. Supported by.

An ink tank unit 3 containing an ink tank (not shown) is mounted and fixed on an ink tank bracket 25 fixed to the rear end of the horizontal plate 24.

A fixed base 4 installed separately behind the support base 2.
Is fixed to the upper end of the support column 41. A control unit 5 containing a power supply circuit board and a control circuit board (not shown) is fixed on the fixed base 4.

An input terminal 6 is provided on the control unit 5, a keyboard 61 for inputting print contents, and a display device 62 for displaying the same are provided, and a control circuit in the control unit 5 is provided. It is connected to the board.

The control unit 5 and the head block 1 are connected by a conduit 7 containing a flat cable, and the ink tank unit 3 and the head block 1 are connected by a conduit 8 containing an ink tube. is there.

2 and 3 are a horizontal sectional view and a vertical sectional view of the head block 1, showing a box-shaped base plate 10 having an upper opening.
A drive circuit board 12 is supported by a pillar 11 therein. The drive circuit board 12 includes a circuit that generates a drive signal for the print head 16 described later. The conduit 7 is connected to the head block 1 via the conduit connector 71, and the tip of the flat cable 72 provided inside is
It is connected to the rear end of the drive circuit board 12 via the socket 73. A drive signal correction circuit board 14 is connected to the tip of the drive circuit board 12 via a card edge connector 13. A drive signal is supplied from the drive circuit board 12 to the drive signal correction circuit board 14, and the drive signal from the drive circuit board 12 is corrected in accordance with the characteristics of the print head 16 to be described later, and the print head 16 to be described later. Is to be supplied to. Further, the ink tube 8 built in the conduit 8 connected through the conduit connector 81.
2 passes through the front plate 10a of the base plate 10 and reaches the front thereof. The rear cover 15 is provided in the upper surface opening of the base plate 10.
Are fixedly provided, and cover the drive signal correction circuit board 14, the drive circuit board 12, and the ink tube 82.

The control circuit board built in the control unit 5 controls the drive of the print head 16 described later via the drive circuit board 12 and the drive signal correction circuit board 14.

An ink jet type print head 16 is fixed to the front surface of the front plate 10a of the base plate 10. A front cover 17 that covers the inkjet print head 16 except for the nozzle surface is detachably connected to the front plate 10a by a set screw 17a. A drive signal correction circuit board 14 is mounted behind the print head 16 and is electrically connected thereto. Further, the front end portion of the ink tube 82 is connected to the rear portion of the print head 16, and ink can be supplied to the nozzle portion 16a provided on the front surface of the print head. The nozzle portion 16a is fitted into a rectangular window hole 17c opening in the front surface 17b of the front cover 17, and the nozzle surface 1
6b is exposed and the nozzle portion 16a is slightly recessed (see FIG. 8).
And the front surface 17b of the front cover are maintained at substantially the same level.

As shown in FIG. 4, the front surface 17b of the front cover is shown.
In the vicinity of one corner of the two corners in the diagonal position of the window hole 17c (bottom right corner and top left corner)
, Each of which is provided with two protrusions 17d. The projections 17d are for contacting a printing surface, which is the lateral abdominal surface of the cardboard box for packaging, and for maintaining a predetermined gap between the printing surface and the printing surface during printing.

As shown in FIGS. 2, 3 and 8, the window hole 17
A packing member 18 such as rubber located around the nozzle surface 16b is interposed in the gap between the nozzle c and the nozzle portion 16a to prevent the ink ejected from the nozzle from entering the inside from the outside. A head vent cap 16c for forcibly pushing out the ink is projected from the side portion of the print head 16 when the ink is clogged due to dust or bubbles in the ink flow path.

3 to 7 show a head block 1 and a horizontal plate 2.
4 shows a means 9 for movably and rotatably supporting. By rotating the head block 1, the height of characters or the like to be printed can be set. FIGS. 4 and 5 are seen from the front side, and FIGS. 6 and 7 are seen from the back side. Rotation support plates 91 and 92 are provided on the rear end side of the base plate 10 so as to project downward. The bracket 93 is provided so as to be capable of sliding contact with the rotation support plates 91 and 92. Figures 4 and 5
, The nozzles 16d are arranged in a row in the horizontal direction in the nozzle portion 16a.
As shown in FIG. 6, a rotation center screw 94 is provided at the rear surface position facing 6d1 so that the centers thereof coincide with each other, and the head block 1 and the bracket 93 are provided with the rotation center screw 94 as shown in FIGS. It is rotatably connected by a screw 94. The bracket 93 is slidably engaged with the horizontal plate 24 in a fixed posture so that the head block 1 moves forward and backward, the head block 1 is rotatable with respect to the bracket 93, and the head block 1 is fixed by the bracket 93.
It is possible to go back and forth with. Rotate the center screw 94 to the nozzle 16
By aligning with the center of the rightmost nozzle 16d1 of d, the portion (for example, the lower side position) of the character printed by the nozzle 16d1 is always kept constant, and the other nozzles 16d1
The height of characters printed by d changes according to the rotation angle.

As means for controlling this rotation angle, FIG.
The rotary support plate 91 shown in FIG. 5 is provided with an arc-shaped guide groove 91a centered on the nozzle 16d1.
Is aligned horizontally, a fixing screw 91b that penetrates the left end of the guide groove 91a and is slidable in the guide groove is screwed onto the front surface of the bracket 93. In addition, FIG.
7 is provided with an arc-shaped guide groove 93a centered on the rotation center screw 94 on the back surface of the bracket 93, and when the nozzle 16b is horizontally aligned, the guide groove 93a is formed.
A fixing screw 93b which penetrates the left end of the rotary support plate 92 and is slidable in the guide groove is screwed to the back surface of the rotary support plate 92.

4 and 6, the fixing screws 91b and 93b are positioned and fixed at the left ends of the guide grooves 91a and 93a, and the nozzles 16d are horizontally aligned. 5 and 7, the fixing screws 91b and 93b are attached to the guide groove 91.
The nozzles 16d ... Are aligned in an upper left slanting state in a state in which they are positioned and fixed in the intermediate portions of a and 93a. If this inclination angle is large, the height difference between the nozzle 16d at the right end and the nozzle 16d at the left end becomes large, so that high-height characters can be printed, and if the inclination angle is small, low-height characters can be printed. , When the nozzles are aligned horizontally, lines or dots are printed.

In order to facilitate setting of the inclination angle, FIG.
As shown in FIG. 7, a scale 95 is provided along the guide groove 93a. The large scale allows the height of characters to be set in steps of 5 mm, allowing printing of characters with a maximum height of 40 mm. The small scale indicates 8 mm and 12 mm as the height usually used for small letters.

In maintenance management of the head block 1, the front cover 17 may be removed without removing the front cover 17 when the ink is forcibly pushed out from the nozzle 16d as a daily management. The ink that has flowed out of the nozzle 16d is the window hole 1
Since the packing member 18 is interposed between the nozzle 7c and the nozzle surface 16b, the print head 16 is not contaminated by getting inside.

This printer is left for a long time,
If a large bubble enters the ink flow path for some reason, it will be out of the daily maintenance described above, so loosen the set screw 17a and remove the front cover 17.
The print head 16 is exposed. This state is shown in FIG. 9, and even if the front cover 17 is removed, the drive signal correction circuit board 14, the ink tube 82, etc. are covered and protected by the rear cover 15. So head vent cap 16
Open c and let a large amount of ink flow out from the nozzle to normalize the function of the printing apparatus.

Next, the printing operation will be described. This printing device prints on the lateral abdominal surface of a cardboard box for packaging, which is transported by a belt conveyor, for example, while transporting without stopping the transport.
The front surface 17b and the nozzle surface 16b can face the printing surface with a gap at least equal to the height of the protrusion 17d.

Therefore, first, the head block 1 is rotated so that characters or the like having a desired height can be printed. As described above, the rotation center screw 94 and the fixing screw 9 of FIGS.
Loosen 1b and 93b, rotate the head block 1 and fix the screws 93b to a height of 15 mm for letters, for example, as shown in FIG.
And tighten the rotation center screw 94 and the fixing screws 91b and 93b again. As a result, the nozzles 16d are aligned in a slanting upward slant as shown in FIG. 5 so that characters or the like having a height of 15 mm can be printed.

Then, the power source is turned on, the print character is input by the keyboard 61 of the input terminal 6, and the print character is displayed on the display device 62. Control unit 5
The print signal, which has been subjected to data conversion by the control circuit board built in the disk, is input to the drive circuit board 12 of the head block 1 through the flat cable 72. Here, only drive pulse signals p1, p2 or p1 for driving the print head 16 in accordance with the print signal as shown in FIG. 10 are generated. Since this drive signal is transmitted to each piezoelectric element (not shown) of the print head 16, the drive circuit board 12
Is supplied to the drive signal correction circuit board 14 through the card edge connector 13. The drive signal given there is corrected according to the characteristics of the print head 16 to correct the print head 1.
6, the piezoelectric element is driven by this signal, ink droplets are ejected from the nozzle 16d, and printing is performed on the printing surface of the box that is conveyed at the same printing timing.
The consumed ink is supplied from the ink tank unit 3 to the print head 16 through the ink tube 82.

[0027]

As described above, in the ink jet printing apparatus of the present invention, the front cover that covers only the ink jet print head except the nozzle surface is detachably provided, and the drive signal correction circuit board and Since the rear cover that covers the ink tube is fixed, it is possible to remove the front cover when it is necessary to discharge a large amount of ink from the nozzles, such as when large bubbles enter the ink flow path. Since the circuit board and the ink tube are covered with the rear cover and are not exposed, there is no possibility that the board portion is stained with ink or touches the ink tube to cause a failure. In addition, even if the ink flows out from the nozzle during routine maintenance, the packing member is placed around the nozzle surface, so the ink does not enter inside and the front cover must be opened frequently. No cleaning work is required, and reliable printing can always be performed.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of the head block of FIG.

FIG. 3 is an enlarged vertical sectional view of the head block of FIG.

FIG. 4 is an enlarged front view showing means for rocking the head block of FIG.

5 is an enlarged front view of the head block of FIG. 1 in a tilted state.

FIG. 6 is an enlarged rear view showing means for rocking the head block of FIG.

FIG. 7 is an enlarged rear view of the head block of FIG. 1 in a tilted state.

FIG. 8 is a partially enlarged cross-sectional view showing a state in which the print head is covered with a front cover.

FIG. 9 is an enlarged exploded perspective view showing a state in which a front cover of the head block is removed.

FIG. 10 is a waveform diagram of a drive signal for the print head.

FIG. 11 is a sectional view of a head block showing a conventional example.

FIG. 12 is a developed perspective view showing a state in which the outer cover is removed and the same as above.

[Explanation of symbols]

 1 Head Block 14 Drive Signal Correction Circuit Board 15 Rear Cover 16 Inkjet Print Head 16b Nozzle Surface 17 Front Cover 82 Ink Tube

Claims (2)

[Claims] 1. An ink jet type print head having an ink tube for supplying ink connected to the rear portion thereof, and a drive signal of the print head is corrected behind the print head according to the characteristics of the print head. A head block having at least a drive signal correction circuit board for supplying the print head to the print head, and the head block is detachably provided with a front cover that covers only the print head except the nozzle surface. In addition, an inkjet printing apparatus is characterized in that a rear cover that covers at least the drive signal correction circuit board and the ink tube is fixedly provided. 2. The ink jet printing apparatus according to claim 1, wherein a packing member located around the nozzle surface is interposed between the front cover and the print head.