JP2010269453A - Inkjet recording apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent deterioration in ink droplet ejection accuracy resulting from the swing of an inkjet head. <P>SOLUTION: An inkjet recording apparatus 1 is configured to perform image formation by ejecting ink droplets from recording heads 76, to a recording medium, and includes: a first carriage 5 which is mounted with the recording heads 76, and is movable in a sub-scanning direction Y; a second carriage 6 which is mounted with ink tanks 62, 62 connected to the recording head 76, main substrates 63, and ink flow valves 64, and is movable in the sub-scanning direction Y following the first carriage 5; and a control section 10 configured to control the movement of the first carriage 5 and the second carriage 6. The control section 10 causes the first carriage 5 to stop when forming an image on the recording medium. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an ink jet recording apparatus.

  Conventionally, as an inkjet recording apparatus for recording a desired image by ejecting ink droplets from an inkjet head to a recording medium, a line head type in which a plurality of inkjet heads are arranged in a head unit for shortening the recording time, etc. It has been known.

  The head unit in this line head type ink jet recording apparatus has a larger weight than a single ink jet head because a plurality of ink jet heads are provided and electrical equipment and ink supply equipment are also added. To increase. In such a heavy-weight head unit, the vibration during acceleration / deceleration increases as the inertial force acting during scanning increases, and as a result of shaking the inkjet head greatly, the ink during image formation that ejects ink droplets while being scanned is obtained. The droplet ejection accuracy is lowered, and as a result, the image quality is degraded.

  Therefore, the electrical equipment and ink supply device are mounted on the moving means separate from the head unit provided with the inkjet head, and the moving means is moved together with the head unit, thereby reducing the weight of the head unit and discharging accuracy. There has been proposed a method for suppressing the decrease in the thickness (see Patent Document 1, for example).

JP 2008-225248 A

  However, in the method described in Patent Document 1, although the reduction in ejection accuracy is suppressed to a certain extent due to the weight reduction of the head unit, the head unit is scanned during image formation, and accordingly, the ink jet head shakes. The drop in discharge accuracy itself still occurs.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an ink jet recording apparatus capable of preventing a drop in ink droplet ejection accuracy associated with shaking of an ink jet head.

In order to solve the above-mentioned problem, the invention according to claim 1
An inkjet recording apparatus that forms an image by ejecting ink droplets from at least one inkjet head to a recording medium,
A first moving means mounted with the inkjet head and movable in a predetermined direction;
Ink supply equipment and electrical equipment connected to the inkjet head are mounted, and second movement means that can move in the predetermined direction following the first movement means;
Movement control means for controlling movement of the first moving means and the second moving means;
With
The movement control means stops the first movement means when an image is formed on the recording medium.

Invention of Claim 2 is the inkjet recording device of Claim 1, Comprising:
The first moving means includes
While having a head position adjustment mechanism capable of adjusting the position of the inkjet head in a direction other than the predetermined direction,
It is possible to move with higher accuracy than the second moving means.

Invention of Claim 3 is an inkjet recording device of Claim 1 or 2, Comprising:
The first moving means and the second moving means are supported on a gantry structure by a gate-shaped first support base and a second support base,
The first support base is formed of a material having a greater weight or strength than the second support base.

  According to the present invention, when the image is formed on the recording medium, the first moving unit on which the ink jet head is mounted is stopped, so that the ink jet head does not shake during image formation. Accordingly, it is possible to prevent a drop in ink droplet ejection accuracy due to the shaking of the inkjet head.

1 is a perspective view of an ink jet recording apparatus according to the present invention. It is the perspective view which looked at the head unit from the back side. It is a front view of a second carriage peripheral part. It is a block diagram which shows the control structure of an inkjet recording device.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view of an ink jet recording apparatus 1 according to the present invention.
As shown in FIG. 1, the inkjet recording apparatus 1 includes a bottom plate 2, and a first support base 3 and a second support base 4 disposed on the bottom plate 2.

  On the bottom plate 2, a platen 21 that supports a recording medium (not shown) from the non-recording surface side and a maintenance unit 22 that performs maintenance of recording heads 76, which will be described later, are shown in the direction of arrow Y in the figure (hereinafter referred to as sub-scanning). In the direction Y). Among these, the platen 21 can be moved in two directions, an arrow X direction (hereinafter referred to as a main scanning direction X) perpendicular to the sub-scanning direction Y and a sub-scanning direction Y by a platen moving mechanism 211 (see FIG. 4). In addition, rotation in the XY plane (horizontal plane) is possible.

  The first support base 3 and the second support base 4 are both gate-shaped support bases arranged to extend in the sub-scanning direction Y across the platen 21 and the maintenance unit 22. It is installed side by side. Among these, the 1st support stand 3 is formed with the material of larger weight or intensity | strength than the 2nd support stand 4, and is formed with the stone material in this embodiment. On the other hand, the 2nd support stand 4 is arrange | positioned by the front side (front side of FIG. 1) of the 1st support stand 3, and is formed with the aluminum material in this embodiment.

  The first support table 3 and the second support table 4 support the gantry structure so that the first carriage 5 and the second carriage 6 can move in the sub-scanning direction Y.

  The first carriage 5 supported by the first support 3 is a first moving unit according to the present invention, and a drive motor 81 (see FIG. 4) for moving the first carriage 5 in the sub-scanning direction Y. It is connected. The first carriage 5 includes a first housing body 51 having a substantially casing shape, and a projecting portion 52 projecting from the first carriage body 51 in the main scanning direction X. The protruding portion 52 is supported by the first carriage body 51 via a head lifting mechanism 82 (see FIG. 4), and can be moved in the vertical direction Z with respect to the first carriage body 51 by the head lifting mechanism 82. It has become. Further, the head unit 7 is suspended from the tip of the projecting portion 52 so as to be close to the second carriage 6 on the front side (front side in FIG. 1) of the second carriage 6.

FIG. 2 is a perspective view of the head unit 7 as seen from the back side (the back side in FIG. 1).
As shown in this figure, the head unit 7 is a rectangular parallelepiped frame. The head unit 7 is suspended from the upper surface of the projecting portion 52 of the first carriage 5 via the head rotating mechanism 83 (see FIG. 4). It can rotate in the XY plane. The head rotating mechanism 83 and the head lifting mechanism 82 are head position adjusting mechanisms according to the present invention.

  A substrate mounting plate 71 is provided at a middle height of the head unit 7. On the substrate mounting plate 71, a relay substrate 72 (see FIG. 4) for controlling driving of nozzles 760,. ) Are stored in the two board boxes 73, 73, respectively. On the back side of the head unit 7 (front side in FIG. 2), two cameras 74, 74 capable of photographing the lower side are arranged. The two cameras 74 and 74 are for confirming and adjusting the ink droplet ejection position, and are used for fine adjustment and coarse adjustment, and have different telephoto magnifications.

  A head plate 75 is attached to the lower end of the head unit 7. On the lower surface of the head plate 75, a plurality of recording heads 76 arranged in the sub-scanning direction Y for each column are provided in two rows in the main scanning direction X so as to form a staggered arrangement.

  The recording heads 76 are ink jet heads according to the present invention, and a plurality of nozzles 760 for ejecting ink droplets are arranged in the sub-scanning direction Y. Further, relay boards 72, 72 (see FIG. 4) in the board boxes 73, 73 are connected to the recording heads 76,. The nozzles 760,... Are provided with piezoelectric elements (not shown) that are deformed by application of a voltage, and the nozzles 760,. And ink droplets are ejected. More specifically, when a driving voltage is applied to the piezoelectric elements, the nozzles 760,... Are deformed to compress an ink flow path (not shown) inside the nozzles 760,. It is designed to be ejected as drops. In addition, although a well-known material can be used as a piezoelectric element material, lead zirconate titanate (PZT) is particularly preferable.

FIG. 3 is a front view of the periphery of the second carriage 6. In addition, in FIG. 3, the external shape of the head unit 7 is shown with the broken line.
As shown in this figure, the second carriage 6 is a second moving means according to the present invention, and is a long box-like shape placed on the second support 4 so as to be movable in the sub-scanning direction Y. The housing 61 is provided. Ink tanks 62 and 62 for storing ink are fixed on the upper surface of the casing 61 at both ends in the sub-scanning direction Y.

  A plurality of main substrates 63 for driving the nozzles 760 of the recording heads 76 are arranged in parallel in the sub-scanning direction Y inside the casing 61 and at both ends in the sub-scanning direction Y. . The main boards 63 are electrical equipment according to the present invention, and are connected to the relay boards 72 and 72 of the head unit 7 by wiring cables (not shown) (see FIG. 4). .. Are provided in the same number as the recording heads 76,... Are connected to the corresponding recording heads 76 via the relay substrates 72, 72.

  A plurality of ink circulation valves 64,... For distributing ink to the nozzles 760,... Of the recording heads 76,. The ink circulation valves 64,... Are electromagnetic valves, and communicate with the ink tanks 62, 62 and the recording heads 76,. Further, the ink circulation valves 64,... Are provided in the same number as the recording heads 76, and each communicates with the corresponding recording head 76. The ink circulation valves 64,... And the ink tanks 62, 62 are ink supply devices according to the present invention.

  In addition, two dampers 65 and 65 are erected obliquely upward in the front of the inside of the casing 61 in the center in the sub-scanning direction Y. The front ends of the two dampers 65 and 65 Are fixed to both ends in the sub-scanning direction Y of the head unit 7 suspended from the first carriage 5. Accordingly, the second carriage 6 is connected to the first carriage 5 via the dampers 65, 65, and thereby can move in the sub-scanning direction Y following the first carriage 5.

Next, the control configuration of the inkjet recording apparatus 1 will be described with reference to FIG.
FIG. 4 is a block diagram showing a control configuration of the inkjet recording apparatus 1.

  As shown in this figure, the ink jet recording apparatus 1 includes a control unit 10. The control unit 10 is a movement control unit according to the present invention, and includes a platen movement mechanism 211, a drive motor 81, a head lifting mechanism 82, a head rotation mechanism 83, cameras 74 and 74, a main substrate 63,. ... and the maintenance unit 22 are connected to control them.

Next, the operation of the inkjet recording apparatus 1 will be described.
First, the operation of the inkjet recording apparatus 1 when an image is formed on a recording medium will be described.
At this time, first, the control unit 10 controls the movement of the first carriage 5 and the second carriage 6 that follows the first carriage 5 in the sub-scanning direction Y by controlling the drive of the drive motor 81, and thereby the first carriage. 5 head units 7 are arranged above the platen 21. Thus, since the first carriage 5 is directly driven by the drive motor 81, the first carriage 5 can be moved with higher accuracy than the second carriage 6 pulled by the first carriage 5 via the dampers 65, 65. Accurate position control is possible.

  Next, the control unit 10 controls the cameras 74 and 74 to focus on the recording medium on the platen 21, and then controls the head lifting mechanism 82 based on the video from the cameras 74 and 74. While adjusting the height of the head unit 7 suspended from the installation portion 52, the rotational position of the head unit 7 is adjusted by controlling the head rotation mechanism 83. Thus, by adjusting the positions of the recording heads 76,... Provided in the head unit 7, the ejection positions of the ink droplets from the nozzles 760,.

  Next, the control unit 10 opens the ink circulation valves 64,... So that ink can be supplied from the ink tanks 62, 62 to the nozzles 760,. Then, the control unit 10 controls the platen moving mechanism 211 while the first carriage 5 is stopped, thereby moving the platen 21 on which the recording medium is placed in the main scanning direction X and / or the sub-scanning direction Y. By controlling the main substrate 63 while moving, a drive voltage is applied to the piezoelectric elements of the nozzles 760,... Via the relay substrates 72, 72, and ink droplets are ejected from the ejection openings of the nozzles 760,. Discharge. Thus, a desired image is formed on the recording medium.

Next, the operation of the ink jet recording apparatus 1 when maintenance of the recording heads 76,... Is performed will be described.
At this time, the control unit 10 controls the drive of the drive motor 81 to move the first carriage 5 and the second carriage 6 in the sub-scanning direction Y, and arranges the head unit 7 above the maintenance unit 22. Then, the control unit 10 controls the maintenance unit 22 to cause the recording heads 76,... Of the head unit 7 to perform a predetermined maintenance operation. The maintenance of the devices other than the recording heads 76 of the first carriage 5 and the second carriage 6 is also performed above the maintenance unit 22.

  As described above, according to the inkjet recording apparatus 1 according to the present embodiment, when the image is formed on the recording medium, the first carriage 5 on which the recording heads 76,. The recording heads 76 are not shaken during the formation. Therefore, it is possible to prevent the ink droplet ejection accuracy from being lowered due to the shaking of the recording heads 76.

  Further, the first carriage 5 (head unit 7) on which the recording heads 76,... Are mounted has relay boards 72, 72 and a camera 74 that cannot be separated from the recording heads 76,. , 74 are mounted, and the ink tanks 62, 62, the main substrate 63,..., And the ink circulation valves 64, which can be separated from the recording heads 76 by a certain distance are mounted on the second carriage 6. Therefore, the head unit 7 can be reduced in weight. Thereby, the shaking at the time of acceleration / deceleration of the head unit 7 can be suppressed, and even when the head unit 7 continues to shake when image formation is performed with the first carriage 5 stopped, It is possible to suppress a drop in ink droplet ejection accuracy due to the shaking. Further, the shaking due to the external force of the head unit 7 can be suppressed, and even when the head unit 7 shakes due to the vibration accompanying the movement of the platen 21 at the time of image formation, the ejection of ink droplets accompanying this shaking. A decrease in accuracy can be suppressed. These effects particularly remarkably act on a head unit (recording head) having a suspended structure like the head unit 7 in the present embodiment.

  Further, the main substrate 63,... And the ink circulation valves 64,... Which are main heating elements are mounted on the second carriage 6, so that the head unit 7 of the first carriage 5 on which the recording heads 76,. The main substrate 63,... And the ink flow valve 64,. Therefore, it is possible to suppress the positional deviation of the recording heads 76,.

  Further, since the head unit 7 is disposed close to the second carriage 6, the relay boards 72, 72 mounted on the head unit 7 are connected to the main boards 63,... Mounted on the second carriage 6. The wiring cable that does not do can be shortened. Thereby, the superimposition of noise on the drive voltage signal can be suppressed. This noise suppression is particularly effective when the ink droplet ejection frequency is high and minute ink droplets are ejected.

  Further, the head unit 7 on which the recording heads 76,... Are mounted only includes the relay boards 72, 72 and the cameras 74, 74 that cannot be separated from the recording heads 76,. Therefore, sufficient space is secured around these devices. Thereby, workability | operativity when performing the maintenance of the head unit 7 can be improved.

  It should be noted that the present invention should not be construed as being limited to the above-described embodiment, and of course can be modified or improved as appropriate.

  For example, in the above embodiment, a plurality of recording heads 76 are mounted on the head unit 7, but it is sufficient that at least one recording head 76 is mounted. However, there are a plurality of effects such as suppression of a decrease in ejection accuracy due to the shaking of the head unit 7 described above, reduction in weight of the head unit 7, and suppression of positional deviation of the recording heads 76 due to thermal deformation of the head unit 7. The recording heads 76,... Are particularly prominent in the line head type ink jet recording apparatus 1.

DESCRIPTION OF SYMBOLS 1 Inkjet recording device 3 1st support stand 4 2nd support stand 5 1st carriage (1st moving means)
6 Second carriage (second moving means)
10 Control unit (movement control means)
62 Ink tank (ink supply device)
63 Main board (electric equipment)
64 Ink distribution valve (ink supply device)
76 Recording head (inkjet head)
82 Head lifting mechanism (head position adjustment mechanism)
83 Head rotation mechanism (head position adjustment mechanism)
Y Sub-scanning direction (predetermined direction)

Claims (3)

An inkjet recording apparatus that forms an image by ejecting ink droplets from at least one inkjet head to a recording medium,
A first moving means mounted with the inkjet head and movable in a predetermined direction;
Ink supply equipment and electrical equipment connected to the inkjet head are mounted, and second movement means that can move in the predetermined direction following the first movement means;
Movement control means for controlling movement of the first moving means and the second moving means;
With
The ink jet recording apparatus, wherein the movement control unit stops the first moving unit when an image is formed on the recording medium. The first moving means includes
While having a head position adjustment mechanism capable of adjusting the position of the inkjet head in a direction other than the predetermined direction,
The inkjet recording apparatus according to claim 1, wherein the inkjet recording apparatus is capable of moving with higher accuracy than the second moving unit. The first moving means and the second moving means are supported on a gantry structure by a gate-shaped first support base and a second support base,
3. The ink jet recording apparatus according to claim 1, wherein the first support base is made of a material having a weight or strength higher than that of the second support base.

Images