JP2011110844A - Inkjet recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet recording device can easily and highly accurately adjusting a paper interval between a recording head and a platen in the whole area of the platen and easily and properly adjusting the paper interval even with respect to a recording material different in thickness. <P>SOLUTION: The platen 40 supporting the recording material 1 includes a plurality of partial platens 4 which are divided in the scanning direction of the recording head 3 and can be moved independently in a direction where the plurality of partial platens 4 come into contact with or separate from the recording head. Each partial platen is positioned in a position at a predetermined distance from the recording head by a positioning means 2a moved toward a guide shaft 7 and held by a platen holding mechanism 6. Each partial platen held by the platen holding mechanism is positioned by the positioning means, to adjust the paper interval. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an ink jet recording apparatus that performs recording by discharging ink from a recording head to a recording material based on image information.

  As an example of a recording device that records an image on a recording material based on image information, such as a printer, a copying machine, a facsimile, or the like, an inkjet that performs recording by discharging ink from a recording head to a recording material such as paper or a plastic sheet There is a recording device. In an ink jet recording apparatus, it is important to keep the distance between the nozzle surface of the recording head and the platen that supports the recording material (hereinafter referred to as the inter-paper distance) at an appropriate value. In order to output high-quality images with high-precision pixel dot placement due to ink droplet adhesion, the distance between the recording surface of the recording material and the nozzle surface of the recording head (hereinafter, between the head paper) is not in contact. It is desirable that it is as small as possible and constant in the scanning direction of the recording head. Further, the optimum value between the head sheets varies depending on the type of recording material and the surrounding environment. Therefore, the ink jet recording apparatus is provided with a function of allowing the recording head to move in the direction of approaching or separating from the platen and changing the inter-paper distance according to the recording conditions.

  In the ink jet recording apparatus, adjustment is performed in the assembly process of the apparatus in order to keep the distance between sheets constant in the scanning direction of the recording head. Further, in order to keep the inter-paper distance constant, it is also necessary to adjust the platen to be parallel to the guide rail that guides the scanning of the recording head. However, in a large recording apparatus that uses a recording material with a width exceeding 1 meter, the casing member that supports the platen may be deformed by its own weight. For this reason, it is necessary not only to adjust the positions of the guide rail and the platen, but also to adjust the parallelism between the recording head to be scanned and the platen with high accuracy.

  In order to suppress deformation of the casing member, there is an apparatus in which rigidity is increased by using an extruded material of an aluminum alloy as a casing material. However, in this case, the cost is several times higher than the case where the casing is configured by combining sheet metal members. Therefore, the flatness is adjusted with high accuracy by moving the platen surface up and down. As a method of adjustment, there are used a method in which the casing supporting the platen is stretched and deformed with respect to other members, and a method in which the platen is attached to a free position with respect to the supporting casing. Yes.

  Patent Document 1 proposes a method of manufacturing an ink jet recording apparatus that processes the platen so that the distance from the recording head to the platen is a predetermined distance instead of adjusting the flatness. Furthermore, the adjusted inter-paper distance may be slightly changed due to vibration shock during transportation, a sudden change in temperature and humidity, or aging. Therefore, Patent Document 2 discloses a method of calculating and storing the relative inclination between the platen and the recording head and correcting the gap calculated when measuring the inclination of the platen using the stored data.

JP 2002-200800 Japanese Patent Laid-Open No. 08-058165

  However, to adjust the paper distance by moving the platen surface up and down, measure the paper distance, move the platen surface, and then measure the paper distance again until the standard accuracy is satisfied. It must be repeated and is very time consuming. In addition, since a special measuring instrument is used to measure the distance between papers, readjustment outside the assembly factory is virtually impossible, and market service personnel need to replace parts related to the adjustment point. There is a problem that repair is not possible.

  The present invention has been made in view of such technical problems. It is an object of the present invention to easily and accurately adjust the paper gap between the recording head and the platen over the entire platen area, and to perform an appropriate paper gap adjustment even for recording materials having different thicknesses. It is an object to provide an ink jet recording apparatus that can be easily performed.

  An inkjet recording apparatus according to the present invention includes a recording head that discharges ink to record an image on a recording material, a carrier that moves by mounting the recording head, a guide shaft that guides the movement of the carrier, A platen that supports a recording material at a position facing the recording head, and the platen is divided in the scanning direction of the recording head, and each of them can be moved in a direction in which the recording head is in contact with or separated from the recording head independently The partial platens are positioned at a predetermined distance from the recording head by positioning means that moves in the direction of the guide shaft, and can be held by a platen holding mechanism. Each partial platen is held by the positioning means while the partial platen is held by the platen holding mechanism. And performing inter-sheet adjustment by positioning.

  According to the present invention, the paper gap between the recording head and the platen can be easily adjusted with high accuracy over the entire platen, and appropriate paper gap adjustment can be performed even for recording materials having different thicknesses. An ink jet recording apparatus that can be easily performed is provided.

1 is a perspective view of an ink jet recording apparatus according to an embodiment. 1 is a longitudinal sectional view of an ink jet recording apparatus according to an embodiment. Perspective view of platen and platen holding mechanism An exploded perspective view of the platen holding mechanism It is a figure which shows the action | operation of the platen holding mechanism by a link, (a) is a perspective view of the state which hold | maintained the platen, (b) is a perspective view when the platen is open | released Longitudinal cross section of inkjet recording device when adjusting the distance between papers The positional relationship of the recording head with respect to the platen is shown, (a) is a longitudinal sectional view showing a standard recording position, and (b) is a longitudinal sectional view showing a paper gap adjustment position.

  Embodiments of the present invention will be specifically described below with reference to the drawings. Note that the same reference numerals denote the same or corresponding parts throughout the drawings. FIG. 1 is a perspective view of an ink jet recording apparatus according to an embodiment, and FIG. 2 is a longitudinal sectional view of the ink jet recording apparatus according to an embodiment. A carrier 2 which is guided by the guide shaft 7 and the guide rail 8 and reciprocates in the width direction of the recording material 1 is disposed. The carrier 2 is equipped with a recording head 3 that records an image by discharging ink. A platen 40 that supports the recording material 1 is disposed at a position facing the recording head 3.

  On the upstream side of conveyance of the platen 40, a conveyance roller pair including a conveyance roller 9 as a driving roller and a pinch roller 10 as a driven roller is disposed. A plurality of nozzles are formed in a predetermined arrangement on the nozzle surface 3 a facing the recording material 1 of the recording head 3. The recording head 3 records an image on the recording material 1 by selectively ejecting ink from a plurality of nozzles based on the image information. In the recording operation, an image for one line is formed by ejecting ink from each nozzle of the recording head 3 to the recording material 1 in synchronization with the movement of the carrier 2. When the recording for one line is completed, the recording material 1 is conveyed by a predetermined pitch by the conveying roller pairs 9 and 10 and then an image for the next one line is formed. In this way, the entire recording material 1 is recorded by alternately repeating the recording for one line and the conveyance at a predetermined pitch.

  The recording apparatus is provided with control means 50 including a controller having a CPU, a memory, an I / O circuit, and the like. The control means 50 controls the operation of the drive motor and various devices according to a control program stored in advance in the internal memory. Thus, the feeding and conveying operations of the recording material 1 are controlled, and the recording head 3 is controlled based on the image information, thereby recording an image on the recording material. The control means 50 controls the operation of the entire apparatus and the timing thereof, in addition to controlling the operation for adjusting the gap between papers to be described later.

  The platen 40 includes a plurality of partial platens 4 divided in the width direction of the recording material 1, that is, in the scanning direction of the recording head 3. Each partial platen 4 is configured to be independently movable in a direction of approaching / separating (approaching or separating) from the recording head 3. FIG. 3 is a perspective view showing a platen 40 composed of a plurality of partial platens and a plurality of platen holding mechanisms 6 provided corresponding to the partial platens. FIG. 4 is an exploded perspective view of the platen holding mechanism 6 operatively connected by the link 24 in FIG. 5 shows a state in which each platen holding mechanism 6 is operated by the link 24, FIG. 5 (a) is a perspective view showing a state in which each partial platen 4 is held, and FIG. 5 (b) shows each partial platen 4 being opened. FIG. FIG. 6 is a longitudinal sectional view of the apparatus for adjusting the distance (inter-paper distance) between the recording head 3 and each partial platen 4. 7 shows the positional relationship of the recording head 3 with respect to the platen 40, FIG. 7 (a) is a longitudinal sectional view showing a standard recording position at a standard inter-paper distance, and FIG. 7 (b) shows a carrier positioning means as a platen. 4 is a longitudinal sectional view showing a paper gap adjustment position for setting an appropriate paper gap distance by being brought into contact with 40. FIG.

  The carrier 2 is located at a standard recording position where the distance (inter-paper distance) between the nozzle surface 3a of the recording head 3 and each partial platen 4 is a predetermined set value (standard inter-paper distance C). In order to obtain an inter-paper distance for recording with the optimum head paper distance (distance between the nozzle surface 3a and the recording material 1) according to the type of recording material 1 (type of material, thickness, etc.), the carrier 2 is mounted so that the vertical position can be adjusted. In the present embodiment, the guide shaft 7 can be adjusted in vertical position by a cam drive (not shown). By adjusting the height position of the guide shaft 7 and adjusting the vertical position of the carrier 2, the recording head 3 and each part are adjusted. The distance between sheets with the platen 4 can be changed from the standard distance C between sheets shown in FIG.

  The width of each partial platen 4 is smaller than the width of the recording head 3 in the scanning direction, and preferably smaller than the width of the nozzle surface 3a in the scanning direction. At the lower end of the carrier 2, an abutting portion 2 a is provided as a positioning means that can abut on each partial platen 4. The lower end (contact surface) of the contact portion 2a is positioned below the nozzle surface 3a by a predetermined distance A (FIG. 7). Further, each partial platen 4 is independently pressed (biased) in a direction approaching the carrier 2 by a spring 5 which is a pressing means. Each partial platen 4 is held at a position defined by a contact portion (positioning means) 2 a provided on the carrier 2 by a plurality of platen holding mechanisms 6 mounted on the chassis 11. The friction member 21 provided in each platen holding mechanism 6 is held in contact with the holding rib 4a of each partial platen 4 by the friction force therebetween. Therefore, each platen holding mechanism 6 is attached so that a friction member arm 22 having a friction member 21 that contacts the holding rib 4 a of each partial platen can move along a friction member arm guide 23 fixed to the chassis 11. ing. That is, each friction member 21 is fixed to the inside of the friction member arm 22, and each friction member arm 22 is movably attached along a guide groove 25 formed in an arm guide 23 fixed to the chassis 11. Yes.

  As described above, each partial platen 4 can be positioned at a predetermined distance from the nozzle surface 3 a of the recording head 3 by the positioning means 2 a provided on the carrier 2 moving along the guide shaft 7. Each partial platen 4 is configured to be held at a predetermined position by a frictional force by each platen holding mechanism 6. And each partial platen 4 becomes a structure which can position each vertical position by the contact part 2a which moves along the guide shaft 7 in the state which hold | maintained each partial platen 4 with the platen holding mechanism 6. FIG. Yes.

  As shown in FIG. 3, links 24 are provided so as to be movable along a plurality of arm guides 23 fixed to the chassis 11. As shown in FIGS. 5A and 5B, each platen holding mechanism 6 is operatively connected by a link 24, and the link 24 scans the recording head 3 in the scanning direction (arrow P direction and It can be moved by a predetermined distance in the opposite direction). Further, each platen holding mechanism 6 moves in a direction in which the print head abuts and separates from the holding rib 4a of each partial platen 4 (in the direction of the arrow Q and in the opposite direction) as the recording head moves in the scanning direction. Guided support is possible.

  Specifically, the arm guide 23 is provided with a guide groove 25 for moving the friction member arm 22 in a direction in which the friction member arm 22 contacts and separates from the partial platen 4. When each platen holding mechanism 6 moves, each friction member arm 22 moves along the guide groove 25, so that the friction member 21 fixed to each friction member arm 22 contacts the holding rib 4a of each partial platen. Move in the direction of contact / separation. Each friction member 21 constitutes friction holding means for holding each partial platen 4 with a frictional force. When the friction member 21 is in contact with the holding rib 4a of the partial platen 4, the link 24 is held so as not to move by a link support member (not shown).

  Each platen holding mechanism 6 is provided with a spring 5 as a pressing means for pressing (urging) the partial platen 4 in a direction in which the partial platen 4 is in contact with the contact portion 2a. Therefore, by automatically controlling the moving direction of the link 24 or manually operating the link 24, the state in which each partial platen 4 is held at a fixed position by a frictional force via each platen holding mechanism 6 and the frictional force is released. The spring 5 can be switched to a state of moving toward the recording head 3. Each partial platen 4 is pushed down to a predetermined position by the contact portion 2a, and is held at the predetermined position by the friction members 21 contacting each other. Each partial platen 4 is returned to the position before adjusting the sheet interval (positioning initial position) by the pressing force of the spring 5 as the pressing means by separating the friction member 21 by the operation of the link 24.

  Next, the configuration and operation for adjusting the paper gap (adjusting the paper gap) will be described. The operation for adjusting the paper gap is controlled by the control means 50. Before the paper gap adjustment, each partial platen 4 is pressed (biased) upward by the spring 5 to be in the standard paper gap position shown in FIG. . When the link 24 is moved in the direction of arrow P as shown in FIG. 5A, the friction member 21 moves away from the holding rib 4a of the partial platen 4, and the frictional force holding each partial platen 4 disappears. . For this reason, each partial platen 4 is pressed by the urging force of the spring 5 and is set at a position closest to the carrier 2 as shown in FIG. On the other hand, by moving the link 24 in the direction opposite to the arrow P and bringing the friction members 21 into contact with the holding ribs 4a of the partial platens 4, the partial platens 4 are moved by the frictional force of the friction members 21 as shown in FIG. ) Is held in the raised position.

  At the lowermost end portion of the carrier 2 guided and supported by the guide shaft 7, an abutting portion 2 a is provided as positioning means that can abut on the upper surface of each partial platen 4. 5B, when the carrier 2 having the contact portion 2a is moved along the guide shaft 7, the contact portion 2a also moves in the direction of the guide shaft 7. Then, when the abutting portion 2 a abuts on the upper surface of each partial platen 4, each partial platen 4 is sequentially pushed down against the frictional holding force. Thereby, each partial platen 4 is held at an appropriate height position having an appropriate inter-paper distance by the frictional force with the holding member 21. By pushing down all the partial platens 4 to the appropriate height position, the platen surface height adjustment work in the entire area of the platen 40 is completed.

  An abutting portion 2a capable of abutting with each partial platen 4 is provided at the lower end portion of the carrier 2, and the vertical position of the guide shaft 7 can be adjusted by operating a cam mechanism (not shown). Therefore, the guide shaft 7 is lowered by cam driving, and the carrier 2 is moved to a paper gap adjustment position as shown in FIGS. 6 and 7B. As shown in FIG. 7, the paper gap adjustment position includes a distance B that the guide shaft 7 has moved from the standard recording position, and a distance A from the nozzle surface 3a of the recording head 3 to the lower end of the contact portion 2a of the carrier 2. Is set to a position where the distance between the standard papers becomes the sum (total value) C. Since the contact portion 2a at this time is below the nozzle surface 3a, each partial platen 4 does not come into contact with the recording head 3.

  The paper spacing adjustment operation is started from the state set in the paper spacing adjustment position in FIG. The paper gap adjustment is performed with reference to the paper gap adjustment position shown in FIGS. 6 and 7B. In that case, it is necessary to adjust the distance (the distance between the head paper) between the nozzle surface 3a and the recording material 1, which is the actual ink droplet flight distance, to an appropriate value according to the thickness of the recording material 1 or the paper quality. . Accordingly, in the actual adjustment of the inter-paper distance, an appropriate amount of head paper is set for the recording material to be used, and the amount of adjustment in consideration of the difference between the head paper distance and the standard paper distance C An adjustment operation is performed with or without adjustment. In addition, the positioning of each partial platen 4 by the positioning means (contact portion) 2 a can be performed in a state where the recording material is supported on the platen 40. According to such a method, the optimum inter-paper distance is adjusted in accordance with the thickness of the recording material, the paper quality, and the like by taking a step of pushing down each partial platen 4 from above the recording material to be used by the contact portion 2a. It can be done automatically.

  As a means for starting the paper gap adjustment operation, for example, a method of operating a button on the operation panel of the recording apparatus is employed. First, in accordance with an instruction input from the operation panel, the link 24 connected to each platen holding mechanism 6 is driven by a solenoid, a motor or the like to release (release) the friction holding of each platen holding mechanism 6 and then adjust it. I do. As another method for starting the paper gap adjustment, for example, a flag for turning on / off a photosensor or the like is provided at a part of the link, and each partial platen 4 is switched when the photosensor is turned on / off. It is possible to take a method for determining that the adjustment state has been reached. Based on this determination, the adjustment operation can be automatically started. As described above, the user can perform an operation at a desired time by an operation from the operation unit or the host (PC or the like), so that the distance between the nozzle surface 3a of the recording head 3 and the platen surface of the platen 40 is always set. An optimal value can be set.

  The partial platen 4 often uses a part formed by molding a resin material, and the flatness of a single part directly affects the distance between sheets. The smaller the dimension of each partial platen 4 in the recording material width direction is, the higher the accuracy of the flatness of the entire platen 40 can be, but the number of parts to be adjusted increases. In the adjustment mechanism according to the present embodiment, adjustment can be performed without measuring the distance between sheets. Therefore, the platen 40 is finely divided into partial platens 4 having the same width as the recording head 3 or smaller than the width of the recording head 3 or the nozzle surface 3a, so that adjustment is required even when the accuracy of the inter-paper distance is improved. Time and effort can be reduced. Furthermore, as a means for simplifying the adjustment of the inter-paper distance, there is a method in which the abutting portion 2a that abuts on the partial platen 4 is constituted by a driven rotating body such as a roller. According to such means, the carrier 2 can be moved with a small force by greatly reducing the frictional resistance between the carrier 2 and the partial platen 4, and the adjustment work can be further simplified.

  According to the embodiment described above, it is not necessary to measure the distance between sheets when adjusting the distance between sheets (adjustment of the distance between sheets), and the time required for the adjustment can be shortened. This eliminates the need for special measuring instruments and facilitates readjustment. Further, as a result of simplifying the adjustment work, the platen can be finely divided to adjust the distance between the sheets with high accuracy, and the quality of the recorded image can be improved. Furthermore, it is possible to obtain an appropriate inter-paper distance in the entire paper region even for recording materials having different thicknesses. Note that the present invention can be similarly applied regardless of the number of ink colors used in the recording head 3 and the number of nozzle surfaces 3a. Further, the recording material 1 may be a cut sheet of a certain size or a long roll paper, and the material thereof may be various as long as image formation is possible, such as paper, plastic sheet, photographic paper, and cloth. Material can be used.

DESCRIPTION OF SYMBOLS 1 Recording material 2 Carrier 2a Positioning means (contact part)
3 Recording head 4 Partial platen 5 Pressing means (spring)
6 Platen holding mechanism 7 Guide shaft 21 Friction holding means (friction member)
23 arm guide 24 link 25 guide groove 40 platen 50 control means

Claims (7)

A recording head that discharges ink and records an image on a recording material;
A carrier that moves with the recording head mounted thereon;
A guide shaft for guiding the movement of the carrier;
A platen that supports the recording material at a position facing the recording head;
With
The platen is composed of a plurality of partial platens that are divided in the scanning direction of the recording head and that are each independently movable in the direction of contact with and separating from the recording head.
The partial platens can be positioned at a predetermined distance from the recording head by positioning means that moves in the direction of the guide shaft, and can be held by a platen holding mechanism.
An ink jet recording apparatus comprising: adjusting the sheet interval by positioning each partial platen by the positioning means while the partial platen is held by the platen holding mechanism. 2. The ink jet recording apparatus according to claim 1, wherein the width of each partial platen is smaller than the width of the recording head in the scanning direction.   3. The ink jet recording apparatus according to claim 2, wherein the width of each partial platen is smaller than the width of the nozzle surface of the recording head in the scanning direction.   The inkjet recording apparatus according to claim 1, wherein the positioning unit is provided on the carrier. Pressing means for pressing the partial platen in a direction in contact with the positioning means; and friction holding means for holding the partial platen with a frictional force;
The partial platen is pushed down by the positioning means and held by the friction holding means coming into contact,
The inkjet recording apparatus according to claim 1, wherein the partial platen is returned to a position before the paper gap adjustment by the pressing unit by separating the friction holding unit.   2. The ink jet recording apparatus according to claim 1, wherein the platen holding mechanism of each partial platen is connected by a link, and simultaneously contacts or separates from each partial platen by the movement of the link.   2. The ink jet recording apparatus according to claim 1, wherein the positioning of the partial platens by the positioning means is performed in a state where a recording material is supported on the platen.

Images