JP2779359B2 - Ink jet printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a physical distribution system and the like, for example, letters, numbers, and other marks and symbols indicating the manufacturer, the contents of the package, the quantity thereof, etc. on the side of the cardboard box for packaging. The present invention relates to an ink-jet printing apparatus used for printing an image.

[0002]

2. Description of the Related Art Conventionally, this type of printing apparatus is roughly composed of four blocks, and a head block of a first block is provided with an ink jet print head and mounted with a drive signal correction board. The second block is an ink tank unit having a built-in ink tank for supplying ink to the print head. The input terminal of the third block is for inputting print contents, and the display device A fourth unit is a control unit that controls the driving of the print head, and includes a drive circuit board that generates a drive signal and generates a signal for driving the print head. 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 bellows-shaped pipe conduit having a flat cable therein, and the drive circuit generated by this drive circuit is provided. The signal is corrected by the drive signal correction circuit board in accordance with the characteristics of the print head and supplied to the print head, and the print head is driven.

[0003] Conventionally, a head block is shown in FIG.
As shown in FIG. 2, an ink jet print head b is stored in an outer case a, and a nozzle plate d of the print head is fitted into a square window hole c opened in the front of the case. As shown in FIGS. 13A and 13B, the outer case a
In the front of the window hole c adjacent to the window hole c protruding beyond the front surface.
There is one in which an L-shaped protective plate e of another member that covers the side surface is adhered.

[0004]

By the way, the cardboard box to be printed flows on the conveyor, passes through the front surface of the ink jet type printing apparatus which is fixedly installed, and is printed on the side surface of the ink jet printing apparatus at the time of passing. Things. FIG.
In the example shown in FIG. 2, the nozzle surface of the print head b is exposed from the window c of the case a, and the nozzle surface is in direct contact with the side surface of the cardboard box.
May be damaged. In the case of the example shown in FIG.
Since the protection plate e is stuck, the print head b can be prevented, but since the protection plate e of a separate member is used,
If there is a problem in terms of cost and the conveyor moves in the opposite direction, for example, when the conveyor moves from left to right on the front surface in FIG. 13A, the protection plate e projects from the nozzle surface and immediately after printing. The printing surface may be slid on the printing surface, and the printing surface may be stained.

Accordingly, an object of the present invention is to prevent the nozzle surface of the print head from directly contacting the surface of a cardboard box or the like on the conveyor, and at the same time, to prevent the printing surface from being stained even when the conveyor moves in the reverse direction. An object of the present invention is to provide an ink jet printing apparatus which can minimize the cost.

[0006]

In order to achieve the above object, the present invention has a head block equipped with an ink jet type print head, and the head block is rotated to change its posture to change the position of a printed character. In a printing apparatus having a variable size, a head block is formed with a square nozzle window for exposing a nozzle surface of the print head, and at least one of the head block and the print head has a nozzle surface. A protrusion protruding more forward than the head block is provided near one of the two sets of corners in a diagonal positional relationship with the window hole. Is configured such that when changing the size of a print character, the protrusion rotates in a direction located outside the print area.

[0007] The above-mentioned projection is constituted by a first projection extending along one side of the corner and a second projection extending along the other side of the corner. Protrusion and second
It is preferable that a gap through which ink can pass is formed between the protrusions.

[0008]

An embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a schematic configuration of a head block 1.
Are supported by a support base 2 so as to be adjustable in height and in a reciprocating direction. That is, the vertical column 21 is provided on the support 2
The horizontal plate 24 is supported by a mounting member 23 fixed to the vertical column, and the head block 1 can move forward and backward and rotate at the rear end at the front end of the horizontal plate. It is 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 separately installed behind the support base 2
Is fixed to the upper end of the support column 41. A control unit 5 including a power supply circuit board and a control circuit board (not shown) is fixed on the fixing base 4.

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

FIGS. 2 and 3 are a cross-sectional view and a vertical cross-sectional view of the head block 1, respectively.
Inside, a driving circuit board 12 is supported by columns 11. The drive circuit board 12 includes a circuit for generating a drive signal for the print head 16 described later. The conduit 7 is connected to the head block 1 via a conduit connector 71.
It is connected to the rear end of the drive circuit board 12 via a socket 73. A drive signal correction circuit board 14 is connected to a leading end of the drive circuit board 12 via a card edge connector 13. The drive signal correction circuit board 14 is supplied with a drive signal from the drive circuit board 12 and corrects the drive signal from the drive circuit board 12 according to the characteristics of a print head described later and supplies the drive signal to the print head. It is. The ink tube 82 contained in the conduit 8 connected via the conduit connector 81 penetrates the front plate 10a of the base plate 10 and reaches the front. The upper opening of the base plate 10 is covered by an upper cover 15.

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

An ink jet 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 ink jet print head 16 is detachably connected to the front plate 10a by a set screw 17a. The front end of the drive signal correction circuit board 14 is the print head 1
6, the front end of the ink tube 82 is connected to the print head 16, and can supply ink to the nozzle portion 16a provided on the front surface of the print head. The nozzle portion 16a is fitted in a square window hole 17c opening on the front surface 17b of the front cover 17, and the nozzle surface 16b is exposed, and the nozzle portion 16a is slightly dented. Surface 16b and front surface 17b of front cover
And are kept at almost the same level.

As shown in FIG. 4, the front surface 17b of the front cover
Near one of the two corners of the diagonal position of the window hole 17c (lower right and upper left corners)
Are provided with two projections 17d, respectively. As shown in FIG. 8, the projections 17d abut on the printing surface g, which is the side surface of the packaging cardboard box G, to maintain a predetermined gap between the printing surface g during printing. is there.

As shown in FIGS. 2 and 3, a seal member 18 made of rubber or the like is provided in a gap between the window hole 17c and the nozzle portion 16a, and ink coming out of a nozzle 16d, which will be described later, enters the inside from the outside. Is prevented. An operation knob 16c protrudes from the side of the print head 16 for forcibly discharging ink when ink is clogged due to dust or bubbles in the ink flow path.

FIGS. 3 to 7 show the head block 1 connected to the horizontal plate 2.
4 shows a means 9 for supporting the retractable and rotatable support. By rotating the head block 1, the height of the characters to be printed can be set. 4 and 5 are viewed from the front side, and FIGS. 6 and 7 are viewed from the back side. On the rear end side of the base plate 10, rotation support plates 91 and 92 (shown in FIG. ) Protrudes, and a bracket 93 is provided so as to be able to slide on the rotation support plates 91 and 92. As shown in FIGS. 4 and 5, nozzles 16d are arranged in a horizontal row in the nozzle portion 16a, and the center of the nozzle portion 16a is located at the back face facing the rightmost nozzle 16d1 as shown in FIG. And a rotation center screw 94 is provided. The head block 1 and the bracket 93
As shown in FIG. 7, it is rotatably connected by the rotation center screw 94. The bracket 93 is slidably engaged with the horizontal plate 24 in a fixed posture so that the head block 1 advances and retreats. The head block 1 is rotatable with respect to the bracket 93, and the head block 1 is moved together with the bracket 93. You can go back and forth. By aligning the rotation center screw 94 with the center of the rightmost nozzle 16d1 of the nozzle 16d, a portion of a character or the like (for example, a lower side position) printed by the nozzle 16d1 is always kept constant and printed by the other nozzles 16d. The height of a part such as a character changes according to the rotation angle.

As means for controlling the rotation angle, FIG.
5 is provided with an arc-shaped guide groove 91a centered on the nozzle 16d1.
When they are horizontally aligned, a fixing screw 91b that penetrates through the left end of the guide groove 91a and is slidable in the guide groove is screwed into the front surface of the bracket 93. Also, FIG.
7 is provided on the back surface of the bracket 93 with an arc-shaped guide groove 93a centered on the rotation center screw 94. When the nozzle 16b is horizontally aligned, the guide groove 93a is provided.
A fixing screw 93b that passes through the left end of the rotation supporting plate 92 and is slidable in the guide groove is screwed to the back surface of the rotation supporting plate 92.

FIGS. 4 and 6 show a state in which the fixing screws 91b and 93b are fixed to the left ends of the guide grooves 91a and 93a, and the nozzles 16d are horizontally aligned. FIGS. 5 and 7 show that the fixing screws 91b and 93b
a, 93a are fixed in a middle position, and the nozzles 16d are aligned in a left-up incline. If the inclination angle is large, the height difference between the nozzle 16d at the right end and the nozzle 16d at the left end is large, so that characters with a high height can be printed. When printing is possible and the nozzles are aligned horizontally, it will be a line or dot print.

To facilitate the setting of the tilt angle, FIGS.
As shown in FIG. 7, a scale 95 is provided along the guide groove 93a. The height of characters and the like can be set in increments of 5 mm by a large scale, and printing of characters and the like having a maximum height of 40 mm is possible. The small scale indicates 8 mm and 12 mm as heights usually used for small letters and the like.

FIGS. 9 and 10 show in detail the formation positions of the protrusions 17d provided on the front surface 17b of the front case 17. FIG. That is, the projection 17d is provided near a set of corners in a diagonal positional relationship with the window hole 17c, and includes a first projection 17d1 extending along one side of the corner,
The second projection 17d2 extends along the other side. A gap 17d3 is formed between the first projection 17d1 and the second projection 17d2 so that ink can pass therethrough.

When the head block 1 is rotated by the above-described means 9 and the size of a character or the like is changed, if the projection 17d enters the printing area, the printing surface is changed. Would be dirty. Therefore, the head block 1 is configured to rotate in a direction in which the protrusion 17d is located outside the printing area.

In FIG. 10A, the rotation angle of the head block 1 is small, the height of a printed character or the like is low, and the printing area S1 is narrow. A first projection 17d1 and a second projection 17 provided at the upper left and lower right corners of the window hole 17c.
The head block 1 is rotated clockwise so that neither d2 is located inside the print area S1. FIG.
In the case of 0 (b), the head block 1 is further rotated and the printing area S2 is wide, but the projections 17d1, 17d
d2 is also located outside the print area S2. FIG.
The same applies to the case of 0 (c).
In this case, the projections 17d1 and 17d2 are located outside the printing area S3.

When the ink flows out of the nozzle 16d, the excess ink flowing down the nozzle surface 16b is removed by the first projection 17d1 and the second projection 17d2 near the lower right corner. Through the gap 17d3 between the front 1
7b, so that the printed surface g is not stained.

The shape of the projections formed at one set of corners is not limited to the example shown in the figure. A protrusion may be formed. In addition, one projection may be provided at one set of corners of the front surface 17b or the nozzle surface 16b. Alternatively, one protrusion may be provided at each set of corners of the front surface 17b, and a groove for ink recovery may be provided along the lower side of either the front surface 17b or the nozzle surface 16b.

Next, the printing operation will be described. This printing apparatus prints, for example, on the side surface of a cardboard box for packaging conveyed by a belt conveyor without stopping the conveyance, so that the front cover 17 is used.
The front surface 17b and the nozzle surface 16b can face the printing surface g with a gap at least equal to the height of the projection 17d (shown in FIG. 8).

First, the head block 1 is rotated so that characters of a desired height can be printed. As described above, the rotation center screw 94 and the fixing screw 9 shown in FIGS.
1b and 93b are loosened, and the head block 1 is rotated to set the fixing screw 93b to a height of 15 mm for characters, for example, as shown in FIG.
And retighten the rotation center screw 94 and the fixing screws 91b and 93b. As a result, the nozzles 16d can print characters and the like having a height of 15 mm in alignment with the upper left slope as shown in FIG. The projection 17d is located outside the printing area at this time.

Then, the power is turned on, and print characters and the like are input by the keyboard 61 of the input terminal 6 and displayed on the display device 62. The print signal subjected to data conversion by the control circuit board built in the control unit 5 is input to the drive circuit board 12 of the head block 1 through the flat cable 72. Here, only the drive pulse signals p1, p2, or p1 as shown in FIG. 11 for driving the print head 16 according to the print signal are generated. Since this drive signal is transmitted to each of the piezoelectric elements (not shown) of the print head 16, the drive circuit board 1
2 is supplied to the drive signal correction circuit board 14 via the card edge connector 13. Then, the given drive signal is corrected in accordance with the characteristics of the print head 16 and supplied to the print head 16, and the piezoelectric element is driven by this signal, ink droplets are ejected from the nozzle 16d, and the print timing is adjusted. Printing is performed on the printing surface g of the conveyed box. The consumed ink is supplied from the ink tank unit 3 to the print head 16 through the ink tube 82.

[0030]

As described above, in the ink jet printing apparatus according to the present invention, the projections provided at the corners of the window hole formed in the head block in a diagonal positional relationship are printed characters. Even if the head block is rotated when changing the size, etc., it is always positioned outside the print area, so that the nozzle surface of the print head does not directly contact the print surface and printing It is possible to prevent the printed surface from being stained when the surface is moved in any direction. Further, the configuration is simple, and the cost can be minimized.

[Brief description of the 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. 1;

FIG. 4 is an enlarged front view showing a means for swinging the head block of FIG. 1;

FIG. 5 is an enlarged front view of a state where the head block of FIG. 1 is inclined.

FIG. 6 is an enlarged rear view showing a unit for swinging the head block of FIG. 1;

FIG. 7 is an enlarged rear view of a state where the head block of FIG. 1 is inclined.

FIG. 8 is a sectional view showing a positional relationship between a printing surface and a head block during printing.

FIG. 9 is a developed perspective view of the head block of FIG. 1;

FIGS. 10A, 10B, and 10C are front views showing a relationship between a protrusion and a print area.

FIG. 11 is a waveform diagram of a drive signal of a print head.

FIG. 12 is a sectional view of a head block showing a conventional example.

13A is a front view of a head block showing another conventional example, and FIG. 13B is a partial cross-sectional view thereof.

[Explanation of symbols]

 Reference Signs List 1 head block 16 ink jet print head 16b nozzle surface 17c window hole 17d protrusion 17d1 first protrusion 17d2 second protrusion 17d3 gap S1, S2, S3 printing area

Claims (2)

(57) [Claims] 1. A printing apparatus having a head block equipped with an ink-jet type print head, wherein the size of a printed character can be changed by rotating the head block to change its posture. A rectangular window hole for exposing a nozzle surface of the print head is formed, and at least one of the head block and the print head is formed with a protrusion protruding forward from the nozzle surface. The protrusion is provided in the vicinity of one set of two corners in a diagonal positional relationship with the window hole, and the head block changes the size of the print character. An ink jet printing apparatus characterized in that the protrusion is rotated in a direction outside the printing area when the printing is performed. 2. The projection according to claim 1, wherein the projection comprises a first projection extending along one side of the corner and a second projection extending along the other side of the corner. An ink jet printing apparatus characterized in that a gap through which ink can pass is formed between the first protrusion and the second protrusion.