JP2015051589A - Ink jet recorder and ink jet record method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress wear generated on a slide bearing, thereby improve durability and achieve cost reduction on a whole body of a recorder.SOLUTION: The recorder comprises: a bearing 305 disposed on a head unit having a record head; and guide rails 20a, 20b, 20c disposed on a frame. The guide rails 20a, 20b, 20c guide the head unit in directions where the head unit comes close to a record medium and the heat unit is separated from the record medium. A contact area of the bearing 305 to the guide rails 20a, 20b, 20c changes according to a movement position of the head unit.

Description

  The present invention relates to an ink jet recording apparatus provided with a movable recording head capable of ejecting ink, and an ink jet recording method using the recording head.

  In general, in a full line type recording apparatus using a long recording head (line head), the recording head is provided so as to be movable toward and away from the recording medium. Within the moving range of the recording head, there are set a plurality of stop positions at which the recording head is stopped, including a recording position where the recording head is stopped for recording an image.

  The recording head is provided with a bearing portion guided by the guide rail so as to move along the guide rail. For example, a metal round bar guide shaft or a sheet metal guide plate is used as the guide rail. As described in Patent Document 1, the bearing portion of the recording head is configured to slide while always maintaining a contact state with the slide shaft necessary for positioning the recording head at a stop position such as a recording position. Has been.

JP 2012-183766 A

  When the bearing of the recording head slides while always maintaining the same contact state as the guide rail, wear of the slide bearing is promoted, and the moving load of the recording head increases, or the recording head moves to a predetermined stop position. There is a risk that accurate positioning cannot be performed.

  An object of the present invention is to suppress wear of a slide bearing.

  An ink jet recording apparatus of the present invention is capable of ejecting ink to a recording medium, and is configured to be movable in a direction approaching and separating from the recording medium, and movement of the recording head in the direction A first guide part that guides the movement of the recording head together with the first guide part, and a first guide part that guides the movement of the recording head together with the first guide part. The guide portion and the second guide portion are configured such that their contact areas change according to the moving position of the recording head.

  According to the present invention, the wear of the slide bearing can be suppressed by changing the contact area of the bearing with respect to the guide rail according to the moving position of the recording head.

1 is a schematic front view for explaining a basic configuration of a recording apparatus of the present invention. FIG. 2 is a block diagram of a control system of the recording apparatus in FIG. 1. It is a perspective view of the engine unit in the embodiment of the present invention. FIG. 4 is a perspective view of an engine frame in the engine unit of FIG. 3. It is the perspective view which looked at the engine frame of Drawing 4 from a different direction. It is a perspective view of the head unit with which an engine unit is equipped. FIG. 4 is a VII arrow view of the head unit of FIG. 3. It is a VIII arrow line view of the head unit of FIG. FIG. 4 is a IX arrow view of the head unit of FIG. 3. FIG. 4 is an X arrow view of the head unit of FIG. 3. It is the perspective view which looked at the head unit of Drawing 3 from a different direction. FIG. 4 is a perspective view of a head unit on which an ink cartridge is mounted. FIG. 13 is an XIII arrow view of the head unit of FIG. 12. It is explanatory drawing of the partition wall in a head unit. It is explanatory drawing of the relationship between an ink cartridge and a partition wall. It is explanatory drawing of the slide bearing with which a head unit is equipped. It is a perspective view of the head drive part with which an engine unit is equipped. It is a perspective view for demonstrating the relationship between a head drive part and a head unit. It is the perspective view which looked at the engine frame of the engine unit from the lower part. It is explanatory drawing of the plunger with which an engine frame is equipped. It is explanatory drawing of the nut unit before attaching to the head holder of a head unit. It is a perspective view of the component of a nut unit. It is explanatory drawing of the nut unit in the middle of attachment with respect to a head holder. It is explanatory drawing of the nut unit at the time of completion of attachment with respect to a head holder. It is a top view of an engine frame. It is sectional drawing in the YY line | wire of FIG. 25 when a head unit exists in a head reference position. It is sectional drawing in the XX line of FIG. 25 when a head unit exists in a head reference position. FIG. 26 is a sectional view taken along line ZZ in FIG. 25 when the head unit is at the head reference position. It is sectional drawing in the YY line | wire of FIG. 25 when a head unit exists in a wiping position. It is sectional drawing in the XX line of FIG. 25 when a head unit exists in a wiping position. FIG. 26 is a cross-sectional view taken along the line ZZ in FIG. 25 when the head unit is in the wiping position. It is sectional drawing in the YY line | wire of FIG. 25 when a head unit exists in a capping position. It is sectional drawing in the XX line of FIG. 25 when a head unit exists in a capping position. FIG. 26 is a cross-sectional view taken along line ZZ in FIG. 25 when the head unit is at the capping position. It is sectional drawing in the YY line | wire of FIG. 25 when a head unit exists in a recording position. FIG. 26 is a sectional view taken along line XX in FIG. 25 when the head unit is at the recording position. FIG. 26 is a sectional view taken along line ZZ in FIG. 25 when the head unit is at the recording position. It is a perspective view of a conveyance unit. It is a perspective view for demonstrating the relationship between a conveyance unit and a head holder. It is a perspective view for demonstrating the relationship between a conveyance unit and a head holder. It is explanatory drawing of the bridge attached to the head holder. It is explanatory drawing of the positional relationship of a slide bearing and a guide rail when a head unit exists in a head reference position and a wiping position. It is explanatory drawing of the positional relationship of a slide bearing and a guide rail when a head unit exists in a head capping position and a recording position.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The recording apparatus of this embodiment is an application example as a full-line type inkjet recording apparatus.

  FIG. 1 is an explanatory diagram of a conceptual configuration example of a full-line type inkjet recording apparatus (hereinafter also referred to as “printer”) 10.

  The printer 10 is connected to a host device 12 such as a personal computer, and image information and the like are sent from the host device 12 to the printer 10. In the printer 10, four recording heads 22 (22K, 22C, 22M, 22Y) capable of ejecting ink are arranged so as to be aligned in the conveyance direction (arrow A direction) of the roll paper P as a recording medium. The recording heads 22K, 22C, 22M, and 22Y are recording heads for ejecting black, cyan, magenta, and yellow ink, respectively. Each recording head 22 is configured to eject corresponding ink from a plurality of ejection ports using ejection energy generating elements such as electrothermal conversion elements (heaters) and piezo elements. In the case of using an electrothermal conversion element, the ink can be foamed by the heat generation, and the ink can be ejected from the ejection port using the foaming energy. These discharge ports are arranged in a direction intersecting (in the present example, orthogonal) with the conveyance direction of the arrow A. These recording heads 22 are so-called long line heads, and extend in a direction intersecting (in the present example, orthogonal) with the conveying direction of the arrow A. The lengths of these recording heads 22 are slightly longer than the maximum width of recording media that can be recorded by the printer 10 (the length in the direction perpendicular to the paper surface of FIG. 1). The recording heads 22 are positioned at predetermined recording positions during the image recording operation.

  A recovery unit 400 is incorporated in the printer 10 for the recovery operation of the recording head 22 (operation for maintaining a good ink discharge state). The recovery unit 400 includes a capping mechanism 50 for removing ink from the ejection port formation surfaces (ejection port formation surfaces) of the respective recording heads 22K, 22C, 22M, and 22Y. The capping mechanism 50 is provided independently for each recording head 22K, 22C, 22M, 22Y. The capping mechanism 50 includes a wiper for wiping the discharge port forming surface, a wiper holding member for holding the wiper, an ink removing member for removing ink adhering to the wiper, and a cap closely contacting the discharge port surface. Is provided.

  The roll paper P is supplied from the supply unit 24 and is conveyed in the direction of arrow A by the conveyance mechanism 26 incorporated in the printer 10. The transport mechanism 26 includes a transport belt 26a for placing and transporting the roll paper P, a transport motor 26b for rotating the transport belt 26a, and a roller 26c for applying tension to the transport belt 26a. The conveyance mechanism 26 may be configured to convey the roll paper P using a conveyance roller, or may constitute a unitized conveyance unit. In a specific configuration example described later, the transport mechanism 26 includes a supply unit 24 and is configured as a transport unit that transports the roll paper P using a transport roller.

  When an image is recorded on the roll paper P, after the recording start position on the roll paper P being conveyed reaches below the recording head 22K, a plurality of discharges in the recording head 22K is performed based on the recording data (image information). Black ink is selectively ejected from the outlet. Similarly, each color ink is ejected in the order of the recording head 22C, the recording head 22M, and the recording head 22Y to record a color image on the roll paper P. The printer 10 includes an ink tank 28 (28K, 28C, 28M, 28Y) that supplies ink to each recording head 22 (22K, 22C, 22M, 22Y). Further, the printer 10 is provided with various pumps (see FIG. 3 and the like) for performing ink supply operation and recovery operation to the respective recording heads 22K, 22C, 22M, and 22Y.

  FIG. 2 is a block diagram of the control system of the printer 10.

  Information such as recording data and commands transmitted from the host PC 12 is received by the CPU 100 via the interface controller 102. The CPU 100 handles the overall control of the printer 10 such as the reception of recording data of the printer 10, the recording operation, and the handling of the roll paper P (including control corresponding to the lifting / lowering operation of the recording head 22, which will be described later). It is. After analyzing the received command, the CPU 100 renders image data of each color component of the recording data by developing a bitmap on the image memory 106. The CPU 100 is connected to various sensors (including a photo interrupter sensor 606 (see FIG. 18) described later).

  When recording an image, first, the capping motor 122 and the head lifting / lowering motor 118 are driven and controlled via the output port 114 and the motor drive unit 116, and the respective recording heads 22 are separated from the corresponding capping mechanism 50 for recording. Move to position. The capping motor 122 is a motor for moving the capping mechanism 50 in the directions of arrows B1 and B2 in FIG. 1, and the head elevating motor 118 is for elevating the recording head 22 in the directions of arrows C1 and C2 in FIG. Motor. Thereafter, a drive motor (not shown) for feeding the roll paper P, a transport motor 26b for transporting the roll paper P at a constant speed, and the like are driven and controlled via the output port 114 and the motor drive unit 116. The roll paper P is conveyed in the direction of arrow A. The timing (recording timing) at which ink starts to be ejected onto the roll paper P conveyed at a constant speed is determined based on the detection timing of the leading edge of the roll paper P by a leading edge detection sensor (not shown). . In synchronism with the conveyance of the roll paper P, the CPU 100 sequentially reads out the recording data corresponding to each ink color from the image memory 106, and the corresponding recording heads 22 </ b> K and 22 </ b> C via the recording head control circuit 112. , 22M, 22Y.

  The CPU 100 executes processing based on the processing program stored in the program ROM 104. The program ROM 104 stores processing programs and tables corresponding to the control flow. The work RAM 108 is used as a working memory. The CPU 100 drives and controls the pump motor 124 via the output port 114 and the motor driving unit 116 during the cleaning operation and the recovery operation of the respective recording heads 22 so as to pressurize and suck ink.

  FIG. 3 is a perspective view of the engine unit 200 incorporated in the printer 10. The engine unit 200 includes a head unit 300, a recovery unit 400, and a pump unit 500 in a resin engine frame 20. It becomes the composition. 4 and 5 are perspective views of the engine frame 20 as seen from different directions. The head unit 300 including the recording head 22 is supported by rail portions 20a, 20b, and 20c formed integrally with the engine frame 20 so as to be movable up and down in the directions of arrows C1 and C2. The recovery unit 400 including the capping mechanism 50 is supported by the rail portions 20d and 20e formed integrally with the engine frame 20 so as to be slidable in the directions of arrows B1 and B2.

  When image recording is started from the capping position where the capping mechanism 50 of the recovery unit 400 is capping the recording head 22 of the head unit 300, the head unit 300 is first raised in the direction of the arrow C1. As a result, the recording head 22 is separated from the capping mechanism 50 and the capping by the capping mechanism 50 is released. The rise of the head unit 300 to the uppermost head reference position is detected by a sensor (a photo interrupter sensor 606 (see FIG. 18 described later)). After detecting this, the head unit 300 is lowered in the arrow C2 direction to a wiping position between the head reference position and the capping position. The head unit 300 is raised and lowered in a direction approaching and separating from the roll paper P in accordance with the rotation direction and the rotation amount of the head lifting motor 118. After the head unit 300 is lowered to the wiping position, as will be described later, the wiper provided in the recovery unit 400 is slid in the direction of arrow D1, and the discharge port surface of the recording head 22 provided in the head unit 300 is wiped by the wiper.

  Thereafter, the head unit 300 is raised until the sensor detects that the head unit 300 has reached the uppermost head reference position. Thereafter, the wiper is moved in the direction of arrow D2 to return to the original standby position, and then the recovery unit 400 is moved in the direction of arrow B2 to shift the capping mechanism 50 from the position directly below the recording head 22. In the meantime, the head unit 300 is lowered in the direction of the arrow C2, and is lowered to a recording position below the capping position for the recording head 22 to record an image.

  By ejecting ink from the recording head 22 at this recording position, an image is recorded on the roll paper P that is continuously conveyed in the direction of arrow A as described above. After the image recording is completed, the head unit 300 is raised, and after the sensor detects that the head unit 300 is raised to the highest head reference position, the head unit 300 is lowered. Meanwhile, the recovery unit 400 is moved to the original position in the direction of the arrow B1, and the head unit 300 is lowered to the capping position, whereby the recording head 22 is capped by the capping mechanism 50.

  FIG. 6 is a perspective view of the head unit 300 as viewed from the discharge port side. 7, 8, 9, and 10 are views taken along arrows VII, VIII, IX, and X in FIG. 6, respectively. The recording head 22 (22K, 22C, 22M, 22Y) is attached to the head holder 302 in parallel by a long screw 307 (see FIG. 8) and a nut 308 (see FIG. 10).

  FIG. 11 is a perspective view of the head unit 300 as viewed from above. In the head unit 300, as shown in FIG. 12, cartridge type ink tanks 28 (28K, 28C, 28M, 28Y) are detachably accommodated. Is done. A storage portion in which these ink tanks (hereinafter also referred to as “ink cartridges”) 28 are stored is partitioned by a partition plate 312. 13 is a perspective view of one partition plate 312, and FIG. 14B is a cross-sectional view of the partition plate 312. The partition plate 312 has a configuration in which two members 315 and 316 are bonded together, and the signal line 313 can be passed between the members 315 and 316 as shown in FIG. . The signal line 313 is for electrically connecting the recording head 22 and the substrate on the recording apparatus side. 15A is an XVa arrow view of FIG. 12, and FIG. 15B is an enlarged view of a part of one partition plate taken along the line XVb-XVb of FIG. 15A.

  16A is a perspective view of the slide bearing 305 provided in the head unit 300, and FIGS. 16B, 16C, 16D, and 16E are respectively XVIb in FIG. 16A. , XVIc, XVId, XVIe. The slide bearing 305 is fixed to the head unit 300 so as to be slidably guided in the directions of arrows C1 and C2 with respect to guide rails (first guide portions) 20a, 20b, and 20c (see FIG. 4) of the engine frame 20. Attach to position.

  As shown in FIG. 16B, the slide bearing (second guide portion) 305 has a substantially circular plane shape having an outer peripheral surface located on a virtual circumference having a diameter D, and guide rails 20a, 20b, 20c. And a groove portion 305a having a width W that is slidably fitted. As shown in FIG. 8, two slide bearings 305 for slidably fitting to the guide rail 20a are attached to the head holder 302, and slidably fitted to the guide rail 20b as shown in FIG. Two slide bearings 305 for mounting are attached. Further, as shown in FIG. 9, one slide bearing 305 for slidably fitting to the guide rail 20c is attached to the head holder 302. A claw portion 305 d is formed on the slide bearing 305. The claw portion 305 d is elastically fitted into a hole 302 b (see FIGS. 7, 8, and 9) formed at the mounting position of the slide bearing 305 in the head holder 302, so that the slide bearing 305 is attached to the head holder 302. Mounted in place. The slide bearing 305 intersects (in the case of this example, orthogonal) the axis (the length direction of the guide rail (the moving direction of the head holder 302)) of the diameter D in FIG. Is attached to the hole 302b so as to be rotatable about the axis). Furthermore, the slide bearing 305 has its pivot range restricted to a predetermined range when the convex portion 302c (see FIGS. 7, 8, and 9) of the head holder 302 is positioned in the concave portion 305c of the slide bearing 305.

  Thus, in this example, a total of five slide bearings 305 are provided to engage with the guide rails 20a, 20b, and 20c. The two slide bearings 305 in FIG. 7 corresponding to the guide rail 20b and the one slide bearing 305 in FIG. 9 corresponding to the guide rail 20c particularly define the position of the side surface of the head unit 300. In addition, the two slide bearings 305 in FIG. 8 corresponding to the guide rail 20a particularly restrict the movement axis of the head unit 300 in the directions of arrows C1 and C2. Thus, the posture of the head unit 300 is determined by the total of five slide bearings 305 that can move together with the head unit 300 and the three guide rails 20a, 20b, and 20c for moving the head unit 300 together with the slide bearing 305. It is prescribed.

  FIG. 17 is a perspective view of a drive unit 600 that raises and lowers the head unit 300 in the directions of arrows C1 and C2. The head lifting motor 118 in the drive unit 600 is a pulse motor that can control the number of rotations (rotation angle) according to the number of pulses applied. The rotational force of the head lifting / lowering motor 118 is transmitted to the pinion 602, the idler gear 603, and the gear portion 604a of the lead screw 604 to rotate the lead screw portion 604b of the lead screw 604. The lead screw portion 604b has a male screw shape, and a nut unit 700 having a female screw shape portion matching the lead screw portion 604b is screwed into the lead screw 604. Since the nut unit 700 is restrained by the engine frame 20 only in its rotation (rotation around the rotation axis of the lead screw 604), the rotation of the lead screw 604 causes the nut unit 700 to move to the arrows C1, C2 according to the lead angle. Go up and down in the direction.

  The nut unit 700 and the head unit are fixed by fitting the nut unit 700 into the opening 302a of the head holder 302 as shown in FIG. When the lead screw 604 rotates, the nut unit 700 moves up and down, and the head unit 300 fixed to the nut unit 700 moves up and down as the nut unit 700 moves up and down. The head raising / lowering motor 118 of the drive unit 600 is screwed to the engine frame 20, and the idler gear 603 is fitted into the shaft portion 20f (see FIG. 4) of the engine frame 20. The lead screw 604 is inserted into a hole 20g (see FIG. 4) of the engine frame 20 and a hole 20h (see FIG. 19) below the hole 20g, and is supported rotatably.

  The lead screw 604 inserted into the hole 20h of the engine frame 20 is always given an upward thrust force (in the direction of the arrow C1) by the plunger 650 positioned below the lead screw 604. As shown in FIGS. 20A and 20B, the plunger 650 includes a piston 651, an outer 652, and a compression spring 653, and an upward thrust force is applied to the lead screw 604 by the compression spring 653. Since the compression spring 653 has a spring force that exceeds the weight of the head unit 300 (including the ink cartridge 28) that moves up and down, the lead screw 604 does not fall downward (in the direction of arrow C2) due to the weight of the head unit 300. Absent. Therefore, an upward thrust force can always be applied to the lead screw 604. This is because even if the lead screw 604 has an appropriate lead angle for self-locking and the nut unit 700 receives a force in the vertical direction (arrows C1 and C2) from other than the lead screw 604, the lead screw This is because 604 does not rotate.

  After attaching the idler gear 603 and the lead screw 604, the idler gear 603 and the lead screw 604 are prevented from coming off by covering the gear cover 605 (see FIG. 18) and screwing. Since the upward thrust force is always applied to the lead screw 604, the position of the lead screw 604 in the thrust direction is defined by the bottom surface of the gear cover 605. Further, a photo interrupter sensor 606 (see FIG. 18) is attached to the gear cover 605, and the aforementioned head reference position can be detected by detecting the sensor flag portion 302d (see FIG. 18) of the head holder 302. it can.

  FIGS. 21A and 21B are detailed views of the nut unit 700. FIG. In the nut unit 700, a latch 702 and a slider stopper 704 are attached to a nut 701 having a female screw shape by a pin 705 so as to be rotatable in the directions of arrows E1 and E2. The pin 705 is an axis having an axis whose axis intersects with the moving direction of the head holder 302 (in the present example, orthogonal). A slider 703 is supported by the latch 702 so as to be slidable in the directions of arrows F 1 and F 2, and the slider 703 is biased in the direction of arrow F 1 by a compression spring 706. The slider stopper 704 is formed with a spring portion 704a as shown in FIGS. 22A and 22B, and the slider stopper 704 is always urged in the direction of arrow E1 by the spring portion 704a.

  FIG. 21 shows a state of the nut unit 700 before the head unit 300 is mounted in the engine frame 20. In this state, the latch 702 is rotated and inclined in the direction of the arrow E1, the slider 703 is held at the slide position in the direction of the arrow F2 by the slider stopper 704, and the compression spring 706 is in a contracted state. When the nut unit 700 is in this state, the head unit 300 can be advanced into the direction of the arrow C2 from above the engine frame 20 without causing the head holder 302 and the nut unit 700 to interfere with each other.

  Further, by causing the head unit 300 to enter in the direction of the arrow C2, as shown in FIGS. 23A and 23B, the inclined portion 302h in the opening 302a of the head holder 302 and the inclined portion 702a of the latch 702 are combined. Then, the latch 702 rotates in the direction of arrow E2. Thereafter, the head unit 300 is lifted up slightly, so that the slider 703 is lifted by the lower edge portion of the opening 302 a of the head holder 302. When the slider 703 is lifted, the stepped portion 703b of the slider 703 and the stopper portion 704b of the slider stopper 704 are separated from each other, and the slider stopper 704 returns in the direction of arrow E1 by the biasing force of the spring portion 704a. As a result, as shown in FIGS. 24A and 24B, the slider 703 is lowered in the direction of the arrow F1 by the compression spring 706, and the nut unit 700 moves in the opening 302a of the head holder 302 with the spring force of the compression spring 706. Locked to.

  As shown in FIG. 24, after the head unit 300 is attached to the engine frame 20 and the nut unit 700 is locked to the head holder 302 of the head unit 300, the head unit 300 can be raised and lowered according to the rotation of the lead screw 604. it can. When the head unit 300 is raised in the arrow C1 direction by the rotation of the lead screw 604, the head holder 302 and the nut unit 700 of the head unit 300 move while maintaining the locked state of FIG. Similarly, when the head unit 300 is lowered in the direction of arrow C2 by the rotation of the lead screw 604, the head holder 302 and the nut unit 700 of the head unit 300 move while maintaining the locked state of FIG. When the head unit 300 receives a force in the direction of the arrow C <b> 1 by the capping mechanism 50 (for example, a cap), the head unit 300 is displaced upward with respect to the nut 701. That is, the surface 302i (see FIG. 24B) of the upper edge portion of the opening 302a of the head holder 302 is displaced upward with respect to the upper surface 701a of the nut 701 (see FIG. 24B), and the compression spring 706. The head unit 300 is displaced in the direction of the arrow C1 so as to shrink. Such displacement of the head unit 300 will be described later.

  When the head unit 300 needs to be replaced for service or the like, the head unit 300 can be removed as follows. First, a flathead screwdriver is inserted into the hole 703a of the slider 703, and the slider 703 is returned to the state shown in FIG. 21 by pushing it in the arrow E1 direction while lifting the slider 703 in the arrow C1 direction. Thereby, the head unit 300 can be extracted in the arrow C1 direction. As described above, the slider 703 is attached in the order shown in FIG. 21, FIG. 23, and FIG.

  Next, a method for positioning the head unit 300 at the above-described (1) head reference position, (2) wiping position, (3) capping position, and (4) recording position will be described.

(1) Head Reference Position FIGS. 26, 27, and 28 are respectively the XX line, the YY line, and the ZZ line of FIG. 25 when the head unit 300 is positioned at the head reference position. FIG.

  The movement of the head unit 300 to the uppermost head reference position of the engine frame 20 is detected by the sensor flag unit 302d (see FIG. 18) in the head holder 302 shielding the photosensor 606. When the head unit 300 moves to the head reference position, the lead screw 604 is kept biased upward (arrow C1 direction) by the plunger unit 650.

  As shown in FIG. 26, the guide rail 20b includes wide guide portions 20b-1, 20b-2, 20b-3, and 20b-4, and narrow non-guide portions 20b-11, 20b-12, and 20b-13. Is formed. The guide portions 20b-1, 20b-2, 20b-3, and 20b-4 are in contact with the groove portion 305a having a width W in the slide bearing 305 attached to the head holder 302 of the head unit 300, and the head is interposed via the slide bearing 305. Position the unit 300. The non-guide portions 20B-11, 20b-12, and 20b-13 do not contact the groove portion 305a of the slide bearing 305 and do not position the head unit 300. Similarly, as shown in FIG. 27, the guide rail 20a has wide guide portions 20a-1, 20a-2, 20a-3, 20a-4 and narrow non-guide portions 20a-11, 20a-12. 20a-13 is formed. As shown in FIG. 28, wide guide portions 20c-1, 20c-2, and 20c-3 and narrow non-guide portions 20c-11 and 20c-12 are formed on the guide rail 20c. Thus, the guide rails 20a, 20b, and 20c have different cross-sectional shapes at different positions in the length direction.

  When the head unit 300 moves to the head reference position, as shown in FIG. 26, the two slide bearings 305 corresponding to the guide rail 20b are in contact with the guide portions 20b-3 and 20b-4 of the guide rail 20b. Further, as shown in FIG. 27, the two slide bearings 305 corresponding to the guide rail 20a are in contact with the guide portions 20a-3 and 20a-4 of the guide rail 20a. Furthermore, as shown in FIG. 28, one slide bearing 305 corresponding to the guide rail 20c contacts the guide portion 20c-3 of the guide rail 20c. FIG. 42A is a conceptual diagram showing the positional relationship between the slide bearing 305 and the guide rails 20a, 20b, and 20c at the head reference position. As described above, at the head reference position, all of the five slide bearings 305 are in contact with the guide portions of the guide rails 20a, 20b, and 20c, and the head unit 300 is positioned through the slide bearings 305. At that time, at least a part of the groove part 305a in each slide bearing 305 may be in contact with the guide part of the guide rails 20a, 20b, 20c, and the other part may be opposed to the non-guide part.

(2) Wiping position The wiping position is a position one step lower than the head reference position as shown in FIGS. 29, 30, and 31. The head unit 300 is moved to the wiping position by driving the head lifting motor 118 with a predetermined number of drive pulses after the photosensor 606 shielded by the sensor flag portion 302d of the head holder 302 is in the transmissive state. . At this time, since the lead screw 604 is maintained in a state of being biased upward by the plunger unit 650, it can be accurately stopped at the wiping position.

  In the wiping position, as in the head reference position, all the five slide bearings 305 are in contact with the guide portions of the guide rails 20a, 20b, and 20c as shown in FIGS. Therefore, the head unit 300 is positioned at the wiping position via these slide bearings 305. At that time, at least a part of the groove part 305a in each slide bearing 305 may be in contact with the guide part of the guide rails 20a, 20b, 20c, and the other part may be opposed to the non-guide part. FIG. 42B is a conceptual diagram showing the positional relationship between the slide bearing 305 and the guide rails 20a, 20b, and 20c at the wiping position.

  At this wiping position, the wiper 52 of the capping mechanism 50 moves in the direction of the arrow D1 while the tip of the wiper 52 enters a predetermined amount L (see FIG. 30) with respect to the ejection port surface of the recording head 22, thereby recording. The ejection port surface of the head 22 is wiped. After completion of the wiping operation, as described above, the head unit 300 is moved to the head reference position, the wiper 52 is moved in the arrow D2 direction, and the original standby position is returned.

(3) Capping position The capping position is a position two steps below the head reference position as shown in FIGS. 32, 33, and 34. The head unit 300 is moved to the capping position by driving the head lifting motor 118 with a predetermined number of drive pulses after the photosensor 606 shielded by the sensor flag portion 302d of the head holder 302 is in a transmissive state. .

  In the capping position, in order for the cap of the capping mechanism 50 to be in close contact with the discharge port forming surface of the recording head 22 and to reliably capping the recording head 22, a spring charged in the cap to urge the cap upward. Must be crushed. The compression spring 706 (see FIG. 24A) of the nut unit 700 that transmits the driving force to the head unit 300 is weaker than the spring charged in the cap. Therefore, when the head unit 300 moves to the capping position, the gap G (see FIG. 24B) between the latch 702 and the slider 703 is reduced, and the spring charged in the cap is compressed. At this time, the force received by the lead screw 604 is the same upward direction as the force urged by the plunger unit 650 (arrow C1 direction), so the head unit 300 accurately stops at the capping position.

  In the capping position, as shown in FIG. 32, the two slide bearings 305 corresponding to the guide rail 20b are in contact with the guide portions 20b-2 and 20b-4 of the guide rail 20b. Further, as shown in FIG. 33, the two slide bearings 305 corresponding to the guide rail 20a are in contact with the guide portions 20a-2 and 20a-4 of the guide rail 20a. As shown in FIG. 34, one slide bearing 305 corresponding to the guide rail 20c contacts the guide portion 20c-2 of the guide rail 20c. FIG. 43A is a conceptual diagram showing the positional relationship between the slide bearing 305 and the guide rails 20a, 20b, and 20c at the capping position. In this way, at the capping position, all of the five slide bearings 305 are in contact with the guide portions of the guide rails 20a, 20b, and 20c, and the head unit 300 is positioned via these slide bearings 305. At that time, at least a part of the groove part 305a in each slide bearing 305 may be in contact with the guide part of the guide rails 20a, 20b, 20c, and the other part may be opposed to the non-guide part.

  Further, in order to prevent excessive bending and tilting of the head holder 302 due to the force from the cap, as shown in FIG. 43B, the portion 20a of the guide portion 20a-4 of the rail 20a that contacts the upper slide bearing 305 at the capping position. -5 is larger in the direction of arrow B2. Thus, the head holder 302 can be supported so that the upper portion of the head unit 300 is not excessively bent or tilted in the B1 direction by the portion 20a-5 having a large cross section in the arrow B2 direction. . That is, the portion 20a-5 can support the head holder 302 via the slide bearing 305 together with the two slide bearings 305 corresponding to the guide rail 20b, and thus stable capping can be performed.

(4) Recording position The recording position is a position three steps below the head reference position as shown in FIGS. The head unit 300 is moved to the recording position by driving the head lifting motor 118 with a predetermined number of drive pulses after the photosensor 606 shielded by the sensor flag portion 302d of the head holder 302 is in a transmissive state. .

  At the recording position, in order to ensure recording accuracy, the head unit 300 must be positioned so that the head unit 300 maintains a predetermined distance from the conveyance surface of the roll paper P in the conveyance mechanism 26 (see FIG. 1). . In a specific configuration example of the transport mechanism 26, the transport mechanism 26 forms a transport unit 800 that transports the roll paper P using a transport roller, as shown in FIG. Further, the transport unit 800 is configured to include the function as the supply unit 24 in FIG. 1. Therefore, in the case of this example, a predetermined space is provided between the head unit 300 and the transport surface 801 of the transport unit 800. Must be kept at an interval of

  On the conveyance surface 801 of the conveyance unit 800, four convex portions (first butting portions) 801a are provided. Further, a total of four locations, that is, two locations on the bottom surface of the head holder 302 in the head unit 300 and bottom surfaces 303a and 303b (see FIG. 41) of the bridge 303 rotatably attached to the head holder 302 as shown in FIG. A second butting portion is formed at the location. These second butting parts correspond to each of the four convex parts (first butting parts) 801a. As shown in FIGS. 39 and 40, the four convex portions 801a abut against each of the second abutting portions, so that the head unit 300 and the conveyance surface 801 of the conveyance unit 800 are spaced at a predetermined interval. Kept.

  FIG. 41 is an explanatory diagram of a bridge attached to the head holder. FIG. 41A is a perspective view of the bridge 303. FIG. 41B is a view of the bridge 303 as viewed from XLIa in FIG. FIG. 41C is a view of the bridge 303 as viewed from XLIc in FIG. FIG. 41D is a view of the bridge 303 as viewed from XLid in FIG.

  The bridge 303 is provided on the downstream side of the head holder 302 in the B1 direction. Note that two second butting portions other than the two second butting portions formed in the bridge 303 are provided on the upstream side of the head holder 302 in the B1 direction. Further, the bottom surface 303a and the bottom surface 303b, which are two second abutting portions of the bridge 303, are located at both ends of the transport surface portion for transporting the roll paper P in the transport mechanism 26 in the direction intersecting with the transport direction A. Is provided. As shown in FIG. 41, a rotation fulcrum 303c is provided at the center of the bridge 303 in the direction intersecting with the transport direction A. The central portion of the bottom surface of the head holder 302 in the direction intersecting with the transport direction A abuts on the rotation fulcrum 303 c of the bridge 303. In such a bumped state, the bridge 303 swings around the rotation fulcrum 303c with respect to the head holder 302, or the head holder 302 swings around the rotation fulcrum 303c with respect to the bridge 303. Thereby, the four convex portions 801a abut against the respective abutting surfaces without rattling.

  When the head unit 300 moves to the recording position, the gap G in FIG. 24B is reduced so that a pressure can be applied to the compression spring 706 of the nut unit 700 that transmits the driving force to the head unit 300. For example, the gap G is reduced from 2.5 mm to 1 mm to apply a pressure to the compression spring 706. Thus, the number of driving pulses of the head lifting motor 118 when the head unit 300 is moved to the recording position is set so as to apply pressure to the compression spring 706. Since the force received by the lead screw 604 at the recording position is in the same direction as the force urged by the plunger unit 650 (arrow C1 direction), the head unit 300 can be accurately stopped at the recording position.

  At the recording position, as shown in FIG. 35, of the two slide bearings 305 corresponding to the guide rail 20b, the lower slide bearing 305 is in contact with the guide portion 20b-1, and the upper slide bearing 305 is the non-guide portion 20c. Opposite to -12. In the recording position, as shown in FIG. 36, of the two slide bearings 305 corresponding to the guide rail 20a, the lower slide bearing 305 is in contact with the guide portion 20a-1, and the upper slide bearing 305 is not guided. It faces the portion 20a-12. Further, at the recording position, as shown in FIG. 37, one slide bearing 305 corresponding to the guide rail 20c is in contact with the guide portion 20c-1. Thus, at the recording position, out of the total five slide bearings 305, each of the three slide bearings 305 contacts the guide portions of the guide rails 20a, 20b, and 20c, and each of the other two slide bearings 305 is a guide. It does not contact the rails 20a and 20b. FIG. 43 (c) is a conceptual diagram showing the positional relationship between the slide bearing 305 and the guide rails 20a, 20b, 20c at the recording position. Thus, the head unit 300 is positioned on the guide rails 20a, 20b, and 20c via the three slide bearings 305. At least a part of the groove part 305a in the three slide bearings 305 may be in contact with the guide part of the guide rails 20a, 20b, and 20c, and the other part may be opposed to the non-guide part.

  In addition, since the other two slide bearings 305 are not constrained without being in contact with the guide rails 20a and 20b, the four projecting portions 801a of the transport surface 801 of the transport unit 800 are placed on the corresponding abutment surface. Certainty strikes. Further, a total of four abutting surfaces of the bottom surface of the head holder 302 facing the four convex portions 801a and the bottom surfaces 303a and 303b of the bridge 303 form a quadrangle, and a nut unit in the directions of arrows C1 and C2 inside the quadrangle. There are 700 field lines. Therefore, these four abutting surfaces do not float from the corresponding four projecting portions 802a, but reliably abut against these projecting portions 802a and are grounded.

  Thus, at the recording position, the three slide bearings contact the corresponding guide rails, while at the head reference position, the wiping position, and the capping position, the five slide bearings contact the corresponding guide rails. As described above, the number of slide bearings that contact the guide rail at the recording position is the smallest among the plurality of stop positions (head reference position, wiping position, capping position, and recording position) of the head unit within the movement range of the head unit. It becomes. That is, the mutual contact area between the slide bearing and the guide rail when the head unit including the recording head stops at each of the plurality of stop positions is minimized when the head unit stops at the recording position. In this way, at the recording position, the head unit is reliably positioned at the recording position by reducing the restraining force of the head unit due to the contact between the slide bearing and the guide rail and abutting the head unit against the convex portion on the transport unit side. Can be positioned.

  As described above, the head unit 300 is positioned at (1) the head reference position, (2) the wiping position, (3) the capping position, and (4) the recording position by the slide bearing 305 and the guide rails 20a, 20b, and 20c. can do. Further, in the lifting / lowering range (movement range) of the head unit 300, the slide bearing 305 passes through a position facing the non-guide portion of the guide rails 20a, 20b, and 20c, and therefore is always relative to the guide rails 20a, 20b, and 20c. No contact in the same state. In this way, by changing the contact area of the slide bearing with respect to the guide rail according to the moving position of the head unit, in particular, the wear of the slide bearing is suppressed, the durability is improved, and the overall cost of the recording apparatus is reduced. Can be realized.

(Other embodiments)
The moving direction of the recording head is not limited to the ascending / descending direction as in the above-described embodiment, and can be arbitrarily set according to the facing direction of the recording head and the recording medium. The stop position of the recording head is not specified as the head reference position, the wiping position, the capping position, or the recording position, and at least the recording position may be included. The stop position of the recording head can be arbitrarily set as a position for executing various processes for the recording head. A high positioning accuracy of the recording head is not required at the recording head moving position other than these stop positions. Therefore, by reducing the contact area (contact amount) between the guide rail and the slide bearing at these moving positions, it is possible to suppress wear of the slide bearing while ensuring the high-precision positioning required for the recording head. it can.

  In addition, the slide bearing is mounted so as to be rotatable about an axis orthogonal to the length direction of the guide rail, so that the position of the slide bearing follows the guide rail, and the recording head can be moved smoothly. Can be. The center of rotation of the slide bearing may be an axis that is orthogonal to the length direction of the guide rail, and can be appropriately set according to the shape of the contact surface between the slide bearing and the guide rail. The slide bearing may be provided integrally with the recording head or a head unit including the recording head.

  Note that “recording” (also referred to as image formation) in the present specification is not specified only when significant information such as characters and graphics is formed. For example, images, patterns, patterns, etc. are widely formed or processed on a recording medium regardless of whether it is significant or not, and whether or not it is manifested so that humans can perceive it visually. This includes the case where it is performed.

  The “recording medium” (also referred to as a sheet) includes not only roll paper but also cut paper. Further, the “recording medium” includes not only paper used in general recording apparatuses but also a wide range including cloth, plastic film, metal plate, glass, ceramics, wood, leather, and the like that can accept ink. .

  Further, the term “ink” should be broadly interpreted in the same way as the definition of “recording”. For example, by being applied on the recording medium, it is used for forming an image, pattern, pattern, etc., processing the recording medium, or processing the ink (for example, coagulation or insolubilization of the colorant in the ink applied to the recording medium). Containing liquid that can be made.

20 Engine frame (frame)
20a, 20b, 20c Guide rail 22 Recording head 300 Head unit 305 Slide bearing (bearing)
P roll paper (recording medium)

Claims (10)

A recording head configured to be capable of ejecting ink to a recording medium and movable in a direction toward and away from the recording medium;
A first guide for guiding the movement of the recording head in the direction;
A second guide part that is movable in the direction along with the recording head and that guides the movement of the recording head together with the first guide part;
The ink jet recording apparatus according to claim 1, wherein the first guide portion and the second guide portion are configured such that a contact area between the first guide portion and the second guide portion changes according to a moving position of the recording head.   The inkjet recording apparatus according to claim 1, wherein the first guide portion has different cross-sectional shapes at different positions in the length direction. Within a range in which the recording head moves, set a plurality of stop positions for stopping the recording head,
The inkjet recording apparatus according to claim 1, wherein the stop position includes a recording position where the recording head stops in order to record an image on the recording medium.   The stop position is at least one of a wiping position at which the recording head stops in order to wipe the discharge port forming surface of the recording head, and a capping position at which the recording head stops to cap the recording head. The inkjet recording apparatus according to claim 3, comprising one of them.   5. The abutting portion for contacting the recording head and positioning the recording head at the recording position when the recording head is moved to the recording position. Inkjet recording device.   6. The ink jet recording apparatus according to claim 5, wherein the contact area when the recording head stops at each of the plurality of stop positions is minimized when the recording head stops at the recording position. .   The said 2nd guide part is attached to the said recording head so that rotation is possible centering | focusing on the axis line of the direction which cross | intersects the length direction of said 1st guide part. Inkjet recording apparatus. A recording head configured to be able to eject ink to the recording medium and movable in a direction approaching and separating from the recording medium; and a first guide portion for guiding the movement of the recording head in the direction. The recording head is movable in the direction together with the recording head, and the recording head is stopped at the recording position by the second guiding portion for guiding the movement of the recording head together with the first guiding portion; An inkjet recording method for recording an image on the recording medium by discharging ink from the recording head,
An ink jet recording method, wherein a contact area between the first guide portion and the second guide portion is changed according to a moving position of the recording head.   9. The ink jet recording method according to claim 8, wherein the recording head is positioned at the recording position by abutting the recording head against an abutting portion at a fixed position. As a stop position for stopping the recording head, a plurality of stop positions including the recording position are set,
The ink jet recording method according to claim 9, wherein the contact area when the recording head stops at each of the plurality of stop positions is minimized when the recording head stops at the recording position. .

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