JP2814852B2 - Inkjet printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet printer, and more particularly to an ink jet printer for printing an output of a computer, a facsimile, a video tape recorder, or the like as a color image or a character on a predetermined sheet.

[0002]

2. Description of the Related Art FIG. 6 is a perspective view showing a main part of a conventional ink jet printer of this type, and FIG. 7 is a perspective view of a print head 1A shown in FIG. .

[0003] Conventional color ink jet printers
As shown in FIG. 7, a print head 1A having a plurality of nozzle groups arranged in a staggered arrangement for each color is used. That is, the head 3 having a plane parallel to one plane of the print head 1A
A is attached via a tab tape 4 and a plurality of nozzles 31 supplied with ink from an ink tank (not shown) storing yellow ink built in the print head 1A. A nozzle 32 that discharges during printing, a nozzle 33 that discharges cyan ink during printing, and a nozzle 34 that discharges black ink are provided in the head 3A.
4 is provided on the surface of the head 3A.

When printing is performed, as shown in FIG. 6, the print head 1A is connected to the printing paper 13 by the wide surface of the head 3A.
Is fixed on the carriage 6 with a fixture (not shown) so as to face. The carriage 6 is slidably mounted on a sliding shaft 7 and a positioning rail 8 and is driven by a pulley 10 of a motor 11 via a belt 9 in a direction A perpendicular to the paper feeding direction B of the printing paper 13. Go to This print head 1
The drive of A is called main operation drive.

The carriage 6 has a print head 1A
One end of a carrier cable 5 for electrically driving the ejection of ink from the inkjet nozzles 31 to 34 is attached, and is electrically connected to the head 3A of the print head 1A via the tab tape 4. Have been. The other end of the carrier cable 5 is connected to a control board 12 for driving the ejection of ink from an inkjet ejection nozzle provided in the print head 1A. This control board 12
Is controlled so that ink is ejected from a predetermined nozzle when the print head 1A passes a predetermined position of the printing paper 13 by the main scanning drive by an electric signal output from the printer.

When one main scanning drive is completed, the printing paper 13 is fed by the width of the openings of the nozzles for discharging ink of each color, that is, the width of the group of nozzles for one color. Paper feed rollers 15a, 15a in the direction (B direction).
The rotation of b, 16a and 16b advances in the direction of arrow B in the figure. Hereinafter, this paper feed drive is referred to as sub-scan drive.
The sub-scanning drive is performed by the motor 17 by each of the paper feed rollers 15.
a, 15b, 16a and 16b.

When these printing operations are performed, dust and paper dust in the air adhere to the surface of the head 3 of the print head 1A, and the ink penetrates into the attached dust and paper powder, and the head 3 Stains the surface. Cleaning is performed by the elastic blade 2A in order to remove such dust and paper dust.

The elastic blade 2A used for cleaning is mainly made of an elastic material such as rubber and has a plate shape. The elastic blade 2A projects in a direction to push the surface of the head 3A slightly more than the opening surface of the nozzles 31 to 34 of the head 3A so that the elastic blade 2A comes into contact with the opening surfaces of the nozzle rows 31 to 34 substantially in parallel. Fixed. As the print head 1A passes over the end surface of the elastic blade 2A, dust, paper dust and excess ink attached to the surface of the head 3A are scraped off. This cleaning operation is performed, for example, every time printing is performed for a predetermined number of lines during printing.

However, among the plurality of nozzles 31 to 34 provided for each color described above, for example, the uppermost nozzle in the drawing of the group of nozzles 31 and the group of nozzles 3
2 is located on or near one horizontal straight line, so if frequent cleaning is performed, the elastic blades 2A in contact with adjacent nozzles in different colors will Different colors of ink are mixed,
The mixed ink enters the nozzles, and if printing is performed in such a state, the characters and images printed on the printing paper are mixed and dirty. In order to avoid this, after cleaning, preliminary ejection of ink in the nozzles has been performed, and ink that may have been mixed has been discarded.

[0010]

In the above-described conventional color ink jet printer, the ink in the nozzle may be mixed in color by the cleaning by the elastic blade, and the ink in the nozzle must be preliminarily ejected and discarded after cleaning. It has disadvantages such as wasteful consumption of ink and a decrease in print output efficiency.

[0011]

According to the ink jet printer of the present invention, a print head having a plurality of nozzle openings for ink jet discharge for each color on one plane is moved in one direction, and a graphic including a color designation from the outside is provided. Alternatively, when a print command for at least one of the characters is received, printing is performed on a predetermined print sheet in accordance with the print command and printing is performed for a predetermined number of lines. In an ink jet printer having a blade drive unit that cleans an opening surface of the nozzle opening provided in the print head at a side end of a blade and performs cleaning of ink attached near the nozzle opening, a plurality of each of the colors is provided. The relative positions of the nozzle openings are the same, and they are separated by a fixed distance in each of the colors in the horizontal and vertical directions. Further, the center lines of the uppermost objects among the openings of the nozzles for each color are arranged so as to be present on one oblique line, and the printing paper is moved in a direction orthogonal to the paper feeding direction of the printing paper. When the opening of the nozzle provided in the print head is displaced to the side of the paper, a straight line that is perpendicular to the plane in which the opening of the nozzle is provided and that is offset from the opening area of each nozzle is rotated. A shaft driving section configured to rotate the elastic blade in a state where one side end of the elastic blade is substantially parallel to the oblique line around the rotation axis.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a perspective view showing a main part of an ink jet printer according to the present invention. FIG. 2 is a partially enlarged view of a print head 1 used in FIG. FIGS. 3 to 5 are explanatory views of different blade driving units used for the elastic blades used in the ink jet printer shown in FIG.

In the embodiment of the present invention shown in FIG. 1, the print head 1 is of a cartridge type in which four colors of ink are built in the print head, and the ink is printed in the order of yellow, magenta, cyan and black from the bottom of the figure. It is built into the ink tank inside. As shown in FIG. 2, the nozzles corresponding to each color include a plurality of nozzles 31 for yellow, a plurality of nozzles 32 for magenta, a plurality of nozzles 33 for cyan, and a plurality of nozzles 34 for black from the bottom in order. Print head 1
The opening surface is provided so as to coincide with the wide surface of the head 3 mounted via the tab pad 4 on the side facing the printing paper,
As shown in the drawing, the nozzle groups of each color are arranged shifted in one direction (rightward in the drawing). For example, a plurality of nozzles 3 arranged similarly to the right nozzle 36 among a plurality of nozzles 31 arranged alternately on two vertical straight lines in a staggered manner.
The nozzles are arranged so as to have an interval of about 0.1 to 1 mm between the leftmost nozzles of the two nozzles. Similarly, the nozzles 33 and 34 for ejecting the other two colors of ink are arranged in the same direction so as to be spaced apart by about 0.1 to 1 mm. The upper and lower positions of the nozzle groups 31 and 32 are arranged such that the uppermost one of the nozzles 31 and the lowermost one of the nozzles 32 are located on a straight line in the horizontal direction. The vertical relationship of 34 and the vertical relationship of nozzles 32 and 33 have the same arrangement. Although the example shown in FIG. 2 is an example of a print head in which the ink tank and the print head are integrated, the case where the ink tank is separate can be similarly considered. Also, regarding the driving of the head, the example of FIG. 1 assumes the case of thermal inkjet, but the method of the present invention is used irrespective of the method as long as the head driving method can be accommodated in a plurality of nozzles. It is possible.

When performing printing, the print head 1 is fixed on the carriage 6 with a fixture (not shown). The carriage 6 is mounted so as to be slidable on a sliding shaft 7 having a longitudinal axis parallel to the paper surface of the printing paper 13 and a positioning rail 8, and is fixed to a rotating shaft of a motor 11 via a belt 9. Pulley 10
Is driven in the direction A by the rotation of. Hereinafter, the driving of the print head 1 is referred to as main scanning driving.

One end of a carrier cable 5 is attached to the carriage 6 in order to electrically drive ink ejection from each nozzle provided in the print head 1. And are electrically connected via a tab tape 4. The other end of the carrier cable 5 is connected to a control board 12 for driving a print head. When the print head 1 passes a predetermined position of the printing paper 13 by the main scanning drive by the control board 12,
Control is performed so that ink is ejected from a predetermined nozzle.

When one main scanning drive is completed, the printing paper 13 is fed by the paper feed rollers 15a, 15 by the width of one nozzle group, for example, a nozzle group formed by a plurality of nozzles 31.
The rotation of b, 16a and 16b advances in the direction of arrow B in the figure. Hereinafter, this paper feed drive is referred to as sub-scan drive. The sub-scanning drive is performed by driving each paper feed roller (15a to 16b) by the motor 17.

When these printing operations are performed, dust and paper dust in the air adhere to the surface of the head 3 provided in the print head 1, and ink penetrates into the attached dust and paper powder. As a result, the surface of the head 3 is soiled. In order to remove these, the elastic blade 2 is arranged so that the side end portion of the elastic blade 2 passes while rubbing the surface of the head 3. This cleaning operation is performed, for example, every time the main scanning drive is performed a predetermined number of times.

The elastic blade 2 is, as shown in FIG.
The head 3 is tilted with the wide surface of the elastic blade inclined with respect to the vertical line by an angle substantially equal to the angle d formed by the oblique line C connecting the uppermost one of the nozzle groups of the head 3 and the vertical line D. The opening of the nozzles 31 to 34 is cleaned by rotating the elastic blade 2 about a rotation axis 20 perpendicular to the wide surface of the nozzle. By doing so, when the side end of the elastic blade 2 passes over the surface of the head 3 during cleaning, a portion where the elastic blade 2 comes into contact with a nozzle that ejects ink of the same color, for example, 31; Since the adjacent nozzles 32 can be made different from the portions where the elastic blades 2 are in contact, ink attached to the adjacent different color discharge nozzles does not enter the nozzles.

Next, an embodiment of a blade driving unit for driving the elastic blade 2 for cleaning in the ink jet printer of FIG. 1 will be described with reference to FIGS.

FIG. 3 is an explanatory view showing the relationship between the print head 1, the elastic blade 2 and the blade drive section 18 when the print head 1 is viewed from above.

In the embodiment of the blade driving unit shown in FIG. 3, the elastic blade 2 is attached to the blade support 21a, and after the print head 1 stops at a predetermined cleaning position, it rotates in the arrow direction F as shown in the figure. Gear 22 around axis 20
The cleaning operation is performed by the rotation by and. The gear 3 is driven by a motor (not shown).

FIG. 4 is an explanatory diagram showing the relationship between the print head 1 and the blade drive unit 18a when viewed from above, which is different from FIG.

In the example shown in FIG. 4, the elastic blade 2 is attached to a blade support 21b, and is rotatable around a rotation shaft 20. Pin 25 is attached to blade support 21b.
Is fixed, and one end of the connecting rod 24 is rotatably attached to the pin 25. The other end of the connecting rod 24 is a pin 26
Thus, it is rotatably attached to the rotating disk 27.
The pin 26 is fixed near the outer periphery of the rotating disk 27.
When the rotating disk 27 is rotated in the E direction by a motor (not shown) or the like, the blade support 216 rotates about the rotation shaft 20 via the connecting rod 24, and the blade 2
In the direction of.

FIG. 5 is an explanatory view showing an embodiment of a blade drive unit different from those shown in FIGS. 3 and 4 used in the ink jet printer shown in FIG. 1, and the print head 1 viewed from above the print head 1. And the relationship with the blade drive unit described above.

The blade drive 18C shown in FIG.
The elastic blade 2 is attached to a blade support 21C rotatably mounted around a rotation shaft 20. One end of a coil spring 28 is fixed to a portion of the blade support 21 below the rotation shaft 20, and one end of the blade support 21C is pulled so as to rotate the blade support 21C counterclockwise. The curved surface of the cam 29 is brought into contact with a portion of the blade support 21C opposite to the fixed portion of the coil spring 28 with respect to the rotating shaft 20. The blade support 21C is rotated in the direction F by rotating the cam 29 by a motor (not shown).
Rotate around 0.

[0027]

As described above, according to the present invention, it is possible to prevent color mixture of ink on the elastic blade when cleaning the opening surface of the nozzle provided in the print head. Color mixing between nozzles that sometimes eject different colors of ink can be prevented, and a clear print output can be obtained. Further, since the preliminary ejection of the ink can be reduced, the ink can be saved, and the life of the ink cartridge and the print head can be prolonged, so that the running cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a main part of an embodiment of an ink jet printer of the present invention.

FIG. 2 is a partially enlarged view of the print head shown in FIG. 1 as viewed from a printing paper side.

FIG. 3 is an explanatory diagram showing one embodiment of a blade driving unit shown in FIG. 1;

FIG. 4 is an explanatory diagram showing an embodiment of a blade driving unit different from that of FIG. 3 in the blade driving unit shown in FIG. 1;

FIG. 5 is an explanatory view showing an embodiment of a blade drive unit shown in FIG. 1 which is different from those shown in FIGS. 3 and 4;

FIG. 6 is a perspective view showing a main part of a conventional ink jet printer of this type.

FIG. 7 is a perspective view of a print head 1A used in the ink jet printer of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Print head 2 Elastic blade 3 Head 4 Tab tape 5 Carrier cable 6 Carriage 9 Belt 10 Pulley 11 Motor 12 Control board 13 Printing paper 15a-15b Paper feed roller 16a-16b Paper feed roller 17 Motor 18 Blade drive part

Claims (1)

(57) [Claims] 1. A print command for at least one of a graphic and a character including a color designation from outside by moving a print head having a plurality of nozzle openings for discharging ink jets for each color on one plane in one direction. When you receive
When printing is performed on a predetermined print sheet in accordance with the print command and printing is performed for a predetermined number of lines, the side end of the elastic blade is provided on the print head outside the print area of the print sheet. An ink jet printer having a blade drive unit that cleans an opening surface of an opening and cleans ink attached near the nozzle opening,
The relative arrangement of the plurality of nozzle openings for each color is the same as each other, and is spaced apart from each other by a certain distance in the horizontal and vertical directions for each color. Are arranged so as to be present on one oblique line, and the opening of the nozzle provided in the print head is provided on the side of the paper surface of the printing paper in a direction orthogonal to the paper feeding direction of the printing paper. When displaced,
The rotation axis is a straight line that is perpendicular to the plane where the nozzle openings are provided and that is offset from the opening area of each nozzle, and one side end of the elastic blade around the rotation axis is An ink jet printer comprising a blade driving unit for rotating the elastic blade in a state substantially parallel to oblique lines.