JPH0929957A - Ink jet printing recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable printing of high resolving power by an inexpensive apparatus while performing interlace printing by simple constitution without enhancing the preciseness of a paper feed mechanism and complicating said mechanism in a ink jet printing recording apparatus. SOLUTION: A carriage 3 is supported on a carriage shaft 7 in a freely revolvable and slidable manner and also supported on a guide plate 8 in a freely slidable manner through a slider 30 composed of a cam having long and short sides (or a roller supported by an inclined groove). The slider 30 changes a posture corresponding to the moving direction of the carriage 3. By this constitution, the carriage 3 is revolved around the carriage shaft 7 when moved forwardly and rearwardly and the printing position of a printing head 2 becomes different and interlace printing is performed by the reciprocal movement of the printing head 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inkjet print recording apparatus, and more particularly to an inkjet print recording apparatus having a print head and a carriage capable of interlaced printing.

[0002]

2. Description of the Related Art Conventionally, in an ink jet type printing recording apparatus (hereinafter referred to as an ink jet printer),
One that has an interlaced printing function that enables high-resolution printing even if the nozzle pitch of the print head is large by shifting the print position during the first and second printing by the reciprocating movement or one-way movement of the print head. is there. When performing such interlaced printing, 1
It is known that the paper feed is made half of the nozzle pitch of the print head in the second and second printing.

[0003]

However, in the conventional ink jet printer for performing interlaced printing as described above, the paper feeding mechanism for interlaced printing must have a high resolution. Therefore, a paper feeding motor or a paper feeding motor is required. It is necessary to increase the precision of the drive gear, which is expensive.
In addition, there is a problem that interlaced printing cannot be performed accurately if the paper feeding mechanism slips. The present invention has been made to solve the above-mentioned problems, and makes it possible to accurately perform interlaced printing by making the position of the print head different between the forward pass and the return pass of the print head with a simple configuration. It is an object of the present invention to provide an inkjet print recording apparatus that can perform high-resolution printing with an inexpensive apparatus that does not require a highly accurate paper feeding mechanism.

[0004]

In order to achieve the above object, an ink jet print recording apparatus according to a first aspect of the present invention includes an ink jet print head for ejecting ink onto a printing medium for printing. Print head unit,
An ink jet type print record comprising a carriage for mounting a print head unit and moving it for printing on a printing medium, the carriage being guided by a carriage shaft and a guide plate so as to be rotatable and linearly reciprocally movable. In the device, the carriage is guided on the guide plate via a slide member provided on the carriage, and the slide member has different postures during forward and backward movements of the carriage, whereby the angular posture of the carriage is changed. Changed to enable interlaced printing.

In the above structure, when the carriage reciprocates, the posture of the slide member is changed between the forward path and the homeward path to change the angular orientation of the carriage, so that the print head mounted on the slide member moves forward and backward. The position is different when returning, and thus interlaced printing can be performed. Therefore, it is possible to perform high-resolution printing with a constant nozzle pitch of the print head with a simple configuration without increasing the precision and complexity of the feeding mechanism of the printing medium.

An ink jet type print recording apparatus according to a second aspect of the present invention is the ink jet type print recording apparatus according to the first aspect, wherein the slide member is rotatably provided and has a long side. It is composed of a cam having a short side or a roller whose shaft is supported by an inclined groove provided in the carriage, and the posture of the cam or roller is different between the forward and backward movements of the carriage, and the print position by the print head is different. The print head is different in pitch by half the nozzle pitch.

In the above structure, a roller having a shaft supported by an inclined groove provided on a cam or carriage having a long side and a short side, which is rotatably provided, is provided as a slide member, and a forward path and a backward path are provided. By changing the posture depending on time, the angular posture of the carriage is changed, and the printing position is shifted by ½ of the nozzle pitch between the forward pass and the backward pass of the print head, which enables interlaced printing. This allows
The same effect as described above can be obtained by simply providing the carriage with simple components.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of an inkjet printer according to the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of a main part of an inkjet printer. The inkjet printer 1 is provided with a carriage 3 that holds a print head 2 that prints by ejecting ink onto printing paper. The print head 2 is provided integrally with the head unit 4, and an ink cartridge 5 (also called an ink tank) that supplies ink to the print head 2 is detachably mounted on the carriage 3 together with the head unit 4. A rear portion of the carriage 3 is movable along a carriage shaft 7 provided in parallel with the sheet feeding roller 6, and a front portion is slidably supported on a guide plate 8. Both ends of the carriage shaft 7 and the guide plate 8 are held by the frame 1a. The reciprocating movement of the carriage 3 is driven by a carriage motor 9 via a belt 10. A platen 11 is provided at a position facing the print head 2. The platen 11 and the print head 2 constitute a printing unit that prints on the fed printing paper. Below the platen 11, a paper feed roller 6 that conveys the print paper while facing the print head 2 is provided. A pressure roller 12 is provided opposite to the paper feed roller 6 to bring the printing paper into close contact with the paper feed roller 6. The paper feed roller 6 is driven by a motor (not shown). The printing paper thus conveyed to the position of the print head 2 is discharged by the paper feed roller 13 and the pressure roller 14 provided above the platen 11 after finishing the printing in the printing section.

A purging device 15 is provided on the side of the platen 11.
Is provided. Inkjet type print head 2
May cause ejection failure due to air bubbles being generated inside or ink droplets adhering to the ejection surface during use, so in order to eliminate this and to recover to a good ejection state There is a purging device 15. The purging device 15 is
When the print head 2 is covered by the cap provided at the tip of the print head 2, a negative pressure is generated by the pump, and the defective ink inside the print head 2 is sucked to recover the print head 2.

Next, the carriage 3 equipped with the head unit 4 of the print head 2 and the ink cartridge 5 provided in the ink jet printer 1 will be described.

2 and 3 are views showing a first embodiment of the carriage 3, and FIGS. 2 (a) and 2 (b) are a front view and a side view showing the carriage 3 in the forward path, and FIG. )
(B) is a front view and a side view showing the carriage 3 when returning. As described above, the carriage 3 has its rear portion slidably supported by the carriage shaft 7 and its front portion
It is slidably supported by the guide plate 8 via a slider 30 provided below the front portion. The slider 30 is provided in order to change the posture of the carriage 3 when the carriage 3 moves forward and backward, and is composed of a cam having a long side and a short side, and a shaft 34 provided on the carriage base 3b below the carriage 3. It is rotatably supported by. Further, the slider 30 is provided with protruding pieces 32a and 32b, and the attitude of the slider 30 is maintained in a state where these protruding pieces 32a and 32b are in contact with the stopper 33 provided on the carriage base 3b. A carriage motor 9 and a belt 10 are connected to a driving piece 3a below the carriage 3, and the carriage 3 is linearly reciprocated.

The print head 2 is provided with a piezoelectric element for ejecting ink, and a plurality of nozzles 2a, which are ink ejection ports when viewed from the front, are obliquely and continuously provided. in this way,
By providing the nozzles 2a obliquely, a large number of nozzles 2a can be provided within a fixed width, so that the nozzle pitch can be substantially miniaturized and the resolution is improved. When the interlaced printing is performed using the print head 2 configured as above, the resolution is further improved. The print head 2 prints by ejecting ink from the nozzles 2 a on the platen 11 onto the printing paper p conveyed by the paper feed roller 6 and the pressure roller 12. The printing paper p after printing is discharged by the paper feed roller 13 and the pressure roller 14.

4A and 4B are a front view and a side view showing the state of the slider 30 when the carriage 3 moves to the left (outward path), and the long side (c + Δ) of the slider 30 is the guide plate 8. Touches. 5A and 5B are a front view and a side view when the carriage 3 moves to the right (return path), and the short side (c) of the slider 30 is in contact with the guide plate 8. In this way, the slider 30 rotates during the forward movement and backward movement of the carriage 3, and the protruding piece 3 of the slider 30 is rotated.
With 2a or 32b in contact with the stopper 33, its rotation is suppressed and its posture is maintained. In this way, the height of the shaft 34 from the guide plate 8 changes by Δ between the forward and backward movements of the carriage 3. Therefore, the carriage 3 rotates around the carriage shaft 7 between the forward path and the moving path, and the vertical position perpendicular to the reciprocating direction becomes different. As a result, the vertical position of the print head 2 That is, the printing positions are different.

Here, the length ratio of the long side to the short side of the slider 30 is set so that the print positions of the print head 2 in the forward pass and in the return pass are shifted from each other by a half pitch. ing. That is, when the nozzle pitch in printing of the nozzles 2a of the print head 2 is 2P, the length H2 from the carriage shaft 7 to the slider 30 and the carriage head 7 to the print head are set as shown in FIG. 2B. 2 nozzle 2
If the respective dimensions are set such that the relationship between the length H1 up to a and the height change amount Δ of the slider 30 is P = (H1 / H2) × Δ, the print position by the print head 2 is Since the forward path and the backward path are displaced by P, the interlaced printing can be performed by printing the carriage 3 twice.

By performing interlaced printing in this manner, for example, even when a print head of 90 dpi (dots per inch) is used, normal printing is performed using a print head equivalent to 180 dpi. A high-resolution printing result equivalent to that in the case can be obtained. Therefore, it becomes possible to perform high-resolution printing by using a print head that can be manufactured relatively inexpensively. It should be noted that, for example, even when two rows of 90 dpi nozzles are arranged side by side by a half pitch and the normal printing is performed, a print result equivalent to 180 dpi can be obtained.
There are two rows of nozzles, and there is a problem that the shape of the print head becomes large and heavy, but such a problem does not occur. Note that the print head 2 is tilted with respect to the print paper p by the rotation operation of the print head 2 due to the height change of the slider 30, but since H1 is larger than P, this tilt amount should be ignored. You can

FIGS. 6 and 7 are views showing a second embodiment of the carriage 3, and FIGS. 6 (a) and 6 (b) are a front view and a side view showing the carriage 3 in the forward path, and FIG. 7 (a). (B)
FIG. 3A is a front view and a side view showing the carriage 3 when returning. In this embodiment, the two carriage bases 3c provided under the carriage 3 are provided with a slant groove 40 whose right side is slanted downward when viewed from the front of the print head 2, and the slant groove 40 can be freely moved. And a roller 42 on which a shaft 41 is supported. A rear portion of the carriage 3 is slidably supported by the carriage shaft 7, and a front portion thereof is slidably supported by the guide plate 8 by rollers 42.

8A and 8B are a front view and a side view showing the state of the roller 42 when the carriage 3 moves to the left (outward path), and the roller 42 is located at the bottom of the inclined groove 40. . 9A and 9B are a front view and a side view showing the state of the roller 42 when the carriage 3 moves to the right (return path), and the roller 42 is located at the uppermost part of the inclined groove 40.
As shown in FIGS. 8A and 8B, when the carriage 3 moves in the forward path, the roller 42 moves the end of the inclined groove 40 in the direction opposite to the moving direction of the carriage 3, that is, the maximum position of the inclined groove 40. It is in the lower position. When the carriage 3 is switched to move in the backward direction, as shown in FIG.
2 moves in the direction opposite to the moving direction of the carriage 3 and moves to the uppermost left end of the inclined groove 40. Thus, the distance between the carriage 3 and the guide plate 8 is d + Δ on the outward path, while it is d on the return path, and the carriage 3
The posture of the printing paper p with respect to the printing paper p changes by Δ,
Along with this, the print head 2 rotates around the carriage shaft 7. Therefore, the print position by the print head 2 is also different when the carriage 3 is moving forward and backward.

Here, the heights of the uppermost portion and the lowermost portion of the inclined groove 40 are set so that the print positions on the forward path and the return path of the print head 2 are deviated from each other by a half pitch. To be done. In this way, interlaced printing can be performed by the reciprocating operation of the carriage 3. That is, the roller 42 provided on the carriage 3 changes its position by changing the position in the inclined groove 40 in accordance with the moving direction of the carriage 3, thereby performing the interlaced printing as in the case of the slider 30. High-resolution printing results can be obtained.

FIG. 10 is a diagram showing a printing state when interlaced printing is performed by shifting the printing position of the print head 2 by a pitch which is half the nozzle pitch. Black dots are dots printed. As described above, according to the inkjet printer 1 of the present embodiment, the slider 30 provided on the carriage 3 rotates in accordance with the moving direction of the carriage 3 to change its height, so that the carriage 3 moves. Since the print position by the print head 2 is rotated by a different distance by a pitch P that is half the nozzle pitch 2P, the interface of the paper feed mechanism is simple and simple without complicating the structure and increasing the accuracy. Race printing can be performed and high-resolution printing results can be obtained.

The present invention is not limited to the configuration of the above embodiment, and various modifications can be made. For example, in the above embodiment, interlaced printing is performed by changing the attitude of the carriage 3 by changing the height of the slider 30 or the roller 42 and changing the print position by the print head 2, but in addition to this, Interlace printing may be performed by feeding the paper by the paper feeding mechanism and shifting the pitch of the relative printing positions of the print head 2 and the printing paper p. In the above embodiment, the rear portion of the carriage 3 is pivotally supported by the carriage shaft 7, and the front portion thereof is the slider 3.
Although the one supported by the guide plate 8 via the roller 0 or the roller 42 is shown, the front part of the carriage 3 (on the side of the print head 2) is rotatably supported by the carriage shaft 7, and the rear part thereof is the slider. It may be supported by the guide plate 8 via 30 or the roller 42. Further, in the present invention, the print position on the outward path of the carriage 3 is shifted by a half pitch of the nozzle pitch, but the present invention is not limited to this.

[0021]

As described above, according to the ink jet print recording apparatus of the first aspect of the present invention, the attitude of the slide member provided on the carriage is changed depending on whether the carriage is moving forward or backward. As a result, the print head mounted on it has different printing positions during forward and backward passes,
As a result, interlaced printing can be performed. Therefore, it is possible to perform high-resolution printing with a simple configuration while maintaining the nozzle pitch of the print head constant and without increasing the precision and complexity of the feeding mechanism for the printing medium. Further, according to the ink jet print recording apparatus of the second aspect of the invention, the rotatable cam provided on the carriage or the roller whose shaft is supported by the slanted groove is formed in the forward path and the backward path. Interlaced printing is possible by changing the posture and shifting the print position by the print head by a half of one nozzle pitch. As a result, the same effect as described above can be obtained by simply providing the carriage with simple constituent members.

[Brief description of drawings]

FIG. 1 is a perspective view of a main part of an inkjet printer according to an embodiment of the present invention.

FIG. 2A is a front view showing the carriage at the time of the outward trip according to the first embodiment of the present invention, and FIG. 2B is a side view of the carriage.

FIG. 3A is a front view showing the carriage at the time of returning to the home according to the first embodiment of the present invention, and FIG. 3B is a side view of the carriage.

4A is a front view showing a state where a long side of a slider is in contact with a guide plate, and FIG. 4B is a side view of the same.

5A is a front view showing a state where a short side of a slider is in contact with a guide plate, and FIG. 5B is a side view of the same.

FIG. 6 (a) is a front view showing the carriage at the time of the outward travel according to the second embodiment of the present invention, and FIG. 6 (b) is a side view thereof.

FIG. 7A is a front view showing a carriage at the time of returning home according to a second embodiment of the present invention, and FIG. 7B is a side view of the same.

FIG. 8A is a front view showing a state in which the roller is at the lowermost portion of the inclined groove, and FIG. 8B is a side view of the same.

9A is a front view showing a state in which the roller is located at the uppermost part of the inclined groove, and FIG. 9B is a side view of the same.

FIG. 10 is a diagram showing a printing state when interlace printing is performed by shifting the print position of the print head by a pitch that is half the nozzle pitch.

[Explanation of symbols]

 1 Inkjet Printer 2 Print Head 3 Carriage 7 Carriage Axis 8 Guide Plate 30 Slider 40 Inclined Groove 41 Axis 42 Roller

Claims (2)

[Claims] 1. A print head unit including an ink jet print head for ejecting and printing ink on a printing medium, and a carriage for mounting the printing head unit and moving the printing head unit for printing on the printing medium. An ink jet type print recording apparatus, wherein the carriage is guided by a carriage shaft and a guide plate so as to be rotatable and linearly reciprocally movable, wherein the carriage is mounted on the guide plate via a slide member provided on the carriage. The inkjet recording apparatus is characterized in that the slide member has different postures during forward and backward movements of the carriage, thereby changing the angular posture of the carriage and enabling interlaced printing. apparatus. 2. The slide member is constituted by a rotatably provided cam having long sides and short sides or a roller having a shaft supported by an inclined groove provided in the carriage, and a forward path of the carriage. 2. The posture of the cam or roller is different at the time of returning and at the time of returning, so that the print position by the print head is different by a half pitch of one nozzle pitch of the print head. Inkjet printing and recording device.