JP2008055756A - Ink-jet recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink-jet recording device which always carries out adequate image recording even if ink is ejected to a recording medium having a different thickness by recording heads arranged along a circumference of a drum. <P>SOLUTION: According to the structure of the ink-jet recording device, the four recording heads 10 arranged along a circumferential surface of the drum 23 in a manner opposed to the same, are individually held by a guide mechanism 25 so as to cope with maintenance and difference in thickness of the recording medium. The guide mechanism 25 has an engaging portion 29 for engaging two guide plates 27-1, 27-2 arranged on both edges of the drum 23 in parallel with each other, with a drum shaft 26, and four guide slots 31 radially formed therein from the engaging portion 29 at regular angular intervals. Then, guide engaging pins 15 of each recording head 10 are slidably fitted into the guide slot 31, and the recording head 10 reciprocatively moves radially with respect to the center of the drum 23. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an ink jet recording apparatus that performs image recording by ejecting ink droplets from a recording head disposed along a circumferential direction of a drum onto a recording medium conveyed on the circumferential surface of the drum.

  Conventionally, ink jet recording apparatuses have been widely used. Inkjet recording apparatuses include those equipped with serial type recording heads mainly used for personal use and those equipped with line type recording heads used for industrial use and capable of high-speed recording.

  The line-type recording head is a recording head having a length corresponding to the dimension in the width direction of a recording medium conveyed by one long head or a plurality of short heads. An ink jet recording apparatus provided with this line type recording head has attracted attention in recent years because it can produce a high-quality recorded matter with a very high processing capacity.

  In an ink jet recording apparatus including a line type recording head, for example, one effective means for transporting a recording medium such as cut paper or roll paper is a transporting means using a drum.

When the recording medium held and conveyed by the drum reaches just below the recording head, ink is ejected from the ink ejection surface of the recording head based on the image information, and an image is recorded.
In general, an ink jet recording apparatus including a line type recording head has four recording heads that discharge, for example, four colors of ink of black, cyan, magenta, and yellow along the circumferential surface of the drum in order to record a color image. Have

  If the ink ejected from the ink ejection surface of these recording heads does not land at the desired same position on the recording medium transported at a constant speed, the image will have a hue different from the hue of the original image, and the image quality will deteriorate. Invite.

  For this reason, the ink ejected from the ink ejection surface of the recording head maintains an accurate gap between the ink ejection surface and the drum outer peripheral surface in order to make the flight distance (time) until landing on the recording surface of the recording medium constant. There must be.

  A configuration of an ink jet recording apparatus that solves such a proposition is disclosed in Patent Document 1. The ink jet printer of Patent Document 1 is a unit main body that collectively holds at least a drum that conveys a print medium (recording medium) and nozzle heads (recording heads) of four colors (cyan, yellow, magenta, and black). And a three-point support mechanism provided on the bracket (device frame), and a lifting unit that lifts and lowers the unit body.

  In this ink jet printer, since the three-point support mechanism holds the unit body at the printing position, the gap between the recording head of each color and the drum outer peripheral surface is accurately maintained at a predetermined value (for example, 1 mm), and each recording is performed. The flying distance of the ink ejected from the head is constant.

In addition, since the center of the arc of the curve connecting the ink discharge surfaces of the recording heads of each color coincides with the central axis of the drum, the discharge direction of the ink discharged from the recording head of each color is orthogonal to the outer peripheral surface of the drum. Yes.
Japanese Patent Laid-Open No. 11-277764

  However, the ink jet printer disclosed in Patent Document 1 is set on the assumption that an image is recorded on a recording medium having a specific thickness in the gap between the recording head and the drum at the printing position. However, various types of recording media having different thicknesses are used as recording media for image recording.

  For example, in the ink jet printer disclosed in Patent Document 1, when a thick recording medium is used, the unit main body holding the recording heads together by the lifting mechanism is raised in a direction away from the drum center in the radial direction. It will be.

  At that time, the center of the arc of the curve connecting the ink ejection surfaces of the recording heads rises by the amount of radial movement from the drum center. That is, the ejection direction of the ink ejected from the ink ejection surface of each recording head is not orthogonal to the drum outer circumferential surface. In addition, the flying distance of the ink ejected to the recording medium differs for each recording head.

As a result, the landing positions of the ink ejected from the recording heads are deviated and the quality of the recorded image is deteriorated.
Accordingly, in order to solve the above-described problem, the present invention provides an ink jet recording apparatus that always performs proper recording even when ink droplets are ejected onto recording media having different thicknesses by a recording head arranged along the circumference of the drum. The purpose is to provide.

  In order to solve the above-described problems, an ink jet recording apparatus of the present invention includes a rotatable drum that holds a recording medium on a cylindrical peripheral surface, a drum that faces the drum, and an ink discharge direction on the peripheral surface of the drum. The recording head arranged perpendicularly to the recording head and the recording head between the image recording position close to the drum and the retracted position separated from the drum move linearly along the ink discharge direction of the recording head. And a guide mechanism for guiding.

  According to the present invention, it is possible to provide an ink jet recording apparatus that always performs proper recording even when ink droplets are ejected onto a recording medium having a different thickness by a recording head arranged along the circumference of the drum. .

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

  FIG. 1A is a perspective view of the configuration of the recording head used in the ink jet recording apparatus according to the first embodiment when viewed obliquely from below, and FIG. 1B is a perspective view of the configuration of the maintenance unit viewed from diagonally above. It is.

  In this embodiment, since four ink colors are used, for example, black, cyan, magenta, and yellow, four recording heads 10 (10k, 10c, 10m, 10y) are used. As shown in FIG. 2, the configuration of each recording head is the same.

  As shown in FIG. 4A, the recording head 10 is provided with four recording head modules 12 on the bottom surface of the head frame 11 with their positions changed in a zigzag shape in the longitudinal direction. The lower surface of each recording head module 12 is an ink ejection surface, and a large number (for example, 300 nozzles per 2.5 cm) of ink ejection nozzles 13 are formed.

  These four recording head modules 12 constitute a line head corresponding to the width of the recording medium. In this embodiment, for example, cut paper or continuous paper is used as the recording medium. Although not particularly shown, ink is supplied to these recording head modules 12 from an ink tank located away from the recording head 10 through a flexible pipe.

  Further, on the head frame 11 of the recording head 10, guide engaging portions 14, which are engaging members corresponding to a guide mechanism described later, are erected integrally with the head frame 11 on both end surfaces in the longitudinal direction.

  On the outer surface of the guide engagement portion 14, guide engagement pins 15 are provided so as to project right next to the upper and lower portions. The two upper and lower guide engaging pins 15 are arranged in series on a line perpendicular to the ink ejection surface of the recording head 10.

The four recording heads 10 for ejecting four colors of ink are provided with maintenance units 16 shown in FIG.
The maintenance unit 16 is configured by holding four maintenance units 17 corresponding to the four recording head modules 12 on a maintenance frame 18. Each maintenance part 17 includes a cap part 21 and a wiper part 22 held by a holding member 19 having a bowl shape.

  The maintenance unit 16 maintains an appropriate ink ejection state of the ink ejection nozzle 13 immediately before the recording head 10 starts recording on the recording medium or every certain period during recording, that is, to prevent clogging. Various maintenance is performed.

  That is, wiping for wiping the ink discharge surface of the recording head module 12 by the wiper unit 22, nozzle suction for ejecting ink into the ink fountain of the cap unit 21, and ink by the cap unit 21 during the recording operation pause of the recording head 10. Perform maintenance operations such as capping to seal the discharge surface from the outside.

  2A is a diagram showing a schematic configuration of an ink jet recording apparatus including the recording head 10 and the maintenance unit 16, and FIG. 2B is a side view of the guide mechanism, and FIG. (d) is a figure explaining the function of a guide mechanism.

  In FIG. 9A, only the drum 23, the maintenance device 24 having the maintenance unit 16, the guide mechanism 25, and the four recording heads 10 (however, the guide engaging portion 14 shown in FIG. 1A) are shown. Show.

  The drum 23 shown in FIGS. 4A and 4B is a device (not shown) that rotates around a drum shaft 26 while adsorbing and holding a recording medium (not shown) on its peripheral surface by a negative pressure or the like. It is attached to the frame.

  A plurality (four in this example) of recording heads 10 are arranged to engage with the guide mechanism 25 so as to face the peripheral surface of the drum 23. The four recording heads 10 are individually held by the guide mechanism 25 for maintenance or to cope with a difference in the thickness of the recording medium.

  The guide mechanism 25 includes two guide plates 27 (27-1, 27-2) provided on both ends of the drum 23, and a stay 28 for connecting the two guide plates 27 in parallel. Is done.

  The two guide plates 27 are each provided with an engaging portion 29 that engages with the drum shaft 26. The two guide plates 27 are formed with four guide long holes 31 which are guide portions arranged radially at equal angles around the engaging portion 29.

  The four guide long holes 31 formed in the two guide plates 27-1 and 27-2, respectively, do not shift in phase in the rotation direction of the engaging portion 29 between the guide plates 27-1 and 27-2. As shown in FIG. A guide engagement pin 15 of the recording head 10 is slidably fitted into the guide long hole 31.

  As a result, the four recording heads 10 are held in a state in which their postures are restricted by the guide mechanisms 25, respectively, and maintained in their restricted postures as shown in FIGS. In this state, the drum shaft 26 is moved toward or away from the peripheral surface of the drum 23 in the radiation direction of the drum shaft 26.

The four recording heads 10 move to positions close to the peripheral surface of the drum 23 with a predetermined gap corresponding to the thickness of the recording medium with respect to the peripheral surface of the drum 23 during the image recording operation.
When a recording medium that is in close contact with the peripheral surface of the drum 23 by suction due to negative pressure or the like passes under the recording head 10 (10k, 10c, 10m, 10y), ink is applied from each recording head 10 to the recording surface of the recording medium. The discharged image is recorded. After the recording operation is completed, the recording medium is removed from the drum 23.

  At the time of assembling the ink jet recording apparatus or replacing the recording head 10, the recording head 10 is attached to the drum 23 simply by engaging the guide engagement pin 15 of the recording head 10 with the guide long hole 31 of the guide mechanism 25. Positioned correctly.

  Further, since the engaging portion 29 of the guide mechanism 25 is fitted to the drum shaft 26 and the guide long hole 31 is formed in the radial direction with respect to the drum shaft 26, the guide engaging pin is inserted into the guide long hole 31. The ink ejection direction of the recording head 10 can be made to coincide with the radiation direction of the drum shaft 26, that is, the perpendicular direction of the peripheral surface of the drum 23.

  Furthermore, with this configuration, as shown in FIGS. 3C and 3D, the recording head 10 can maintain image recording positions corresponding to different thicknesses while the ink ejection direction always passes through the drum shaft 26. It is possible to move between the retracted positions.

  On the other hand, the maintenance device 24 has a maintenance holding part 32 for holding the four maintenance units 16 and a maintenance holding part 32 at the upper end, as shown in FIG. A rotation holding portion 33 that rotates is provided.

  The lower surface 32 d of the maintenance holding portion 32 is formed with an arc slightly larger than the arc formed by the peripheral surface of the drum 23 with the drum shaft 26 as the center, and is disposed with a predetermined gap from the peripheral surface of the drum 23. ing.

  The upper surface 32u of the maintenance holding part 32 is also formed along a virtual line connecting the upper surfaces of the maintenance parts 17 of the maintenance units 16 shown in FIG. This imaginary line also forms a large arc around the drum shaft 26. The maintenance device 24 is disposed in a state of being retracted from the recording head 10 to the downstream side of the recording medium conveyance direction of the drum 23 when performing image recording.

  Thereby, the lower surface 32d of the maintenance holding part 32 can be used as a guide for the recording medium. That is, by disposing the lower surface 32d and the peripheral surface of the drum 23 with a predetermined gap, it is not necessary to separately provide a mechanism for guiding the recording medium after image recording, and the cost can be reduced.

  In order to move the maintenance device 24 between the retracted position and the maintenance position, an independent motor may be used, but a drive system for driving the drum 23 is used, and a switching device such as a clutch is provided. The rotation of the drum 23 and the rotation of the maintenance device 24 may be switched and used.

  FIGS. 3A to 3D are diagrams for explaining an operation when the recording head 10 is maintained. FIG. 2A shows the positional relationship between the recording head 10 at the image recording position and the maintenance device 24 at the retracted position.

  2B shows the positional relationship between the recording head 10 in the retracted position and the maintenance device 24 in the retracted position, and FIG. 2C shows the recording head 10 in the retracted position and the maintenance device 24 in the maintenance position. The positional relationship is shown. FIG. 4D shows the positional relationship between the recording head 10 at the maintenance position and the maintenance device 24 at the maintenance position.

  That is, each recording head 10 is configured to be able to move the image recording position, the retracted position, and the maintenance position in both forward and reverse directions, and the maintenance device 24 is configured to be able to move the retracted position and the maintenance position in both forward and reverse directions. .

  Thus, by rotating the maintenance device 24 around the axis of the drum 23, the size of the entire maintenance unit in the main body device (inkjet recording device) becomes compact and the linear movement is made. Has the advantage of reducing dead space.

  When maintenance is performed on the recording head 10 by the maintenance device 24, first, each recording head 10 is moved from the image recording position shown in FIG. 5A to the retracted position shown in FIG. Moves away from each other radially.

Next, the maintenance device 24 rotates from the retracted position shown in FIG. 5B to the maintenance position shown in FIG.
Subsequently, each recording head 10 moves from the retracted position shown in FIG. 4C to the maintenance position shown in FIG.

  At this time, the moving direction of each recording head 10 arranged in an arc shape moves toward the center of the arc, that is, the drum shaft 26, so that the maintenance unit 16 of the maintenance device 24 and the recording head module 12 of the recording head 10 are connected. The relative displacement of the two at the time of contact is only a displacement in the direction perpendicular to the nozzle surface, and no displacement in a direction rubbing the nozzle surface occurs.

  In the relationship between the recording heads 10 and the maintenance device 24 at the maintenance position, the maintenance unit 17 of each maintenance unit 16 of the maintenance device 24 is correctly placed on the arrangement surface of the ink discharge nozzle 13 in the recording head module 12 of each recording head 10. It is comprised so that it may oppose.

  In this state, the maintenance operation by the maintenance device 24 for the recording head 10, for example, cleaning or capping is performed. When the maintenance of the recording head 10 is completed (cleaning is completed or capping is released), the recording head 10 is moved to the retracted position shown in FIG.

Next, the maintenance device 24 rotates from the maintenance position to the retracted position shown in FIG. Then, the recording head 10 returns to the image recording position shown in FIG.
At this time, the moving direction of the recording head 10 is moved in such a posture that the extended line in the ink discharge direction always passes through the center of the drum 23 while being guided by the guide slot 31 of the guide mechanism 25 as described above.

Thereby, the landing position of the ejected ink at the time of returning to the image recording position is accurately reproduced, and the gap between the recording head 10 and the peripheral surface of the drum 23 is also accurately reproduced.
FIG. 4 is a diagram illustrating an example of a moving mechanism for moving the recording head up and down with respect to the drum in the ink jet recording apparatus having the above configuration.

  In FIG. 4, the guide engagement pins 15 provided at the guide engagement portions 14 at both ends of the recording head 10 are in contact with the lower side thereof and are moved up and down so as to be linearly movable in the radiation direction of the drum shaft 26. A member 34 is provided.

  The elevating member 34 is formed with an abutting portion 35 that abuts on the lower guide engaging pin 15 of the recording head 10, and an inclined upward outward from the abutting portion side along the radiation direction of the drum shaft 26. A slope portion 36 is provided.

  Further, conical moving cams 37 having the drum shaft 26 as the axial center position are arranged on both sides of the drum 23. A conical slope portion 38 of the moving cam 37 is in contact with the slope portion 36 of the elevating member 34.

  The moving cam 37 is configured to be movable along the extending direction of the drum shaft 26 by a driving means (not shown). As a driving means of the moving cam 37 in the direction of the drum shaft 26, for example, a feed screw or a stepping motor may be used.

  For the position control of the recording head 10 with respect to the drum 23, a position control means usually used for such position control such as a sensor for detecting the number of pulses of the stepping motor or the position of the recording head 10 may be used.

  When the moving cams 37 on both sides of the drum 23 reciprocate in the direction of the drum shaft 26, the inclined surface portion 36 of the elevating member 34 that is in contact with the inclined surface portion 38 of the moving cam 37 moves forward and backward in the radiation direction of the drum shaft 26. That is, the contact portion 35 of the elevating member 34 also moves forward and backward in the radiation direction.

  As the abutting portion 35 advances and retreats in the radiation direction, the guide engaging pin 15 of the recording head 10 abutting on the abutting portion 35 is pushed by the abutting portion 35 or released. The guide plate 27 reciprocates in the radiation direction along the guide long hole 31.

  That is, the recording head 10 can be displaced in the radiation direction. When performing image recording on recording media having different thicknesses, the movement of the movable cam 37 is stopped when the recording head 10 reaches a predetermined gap with respect to the drum 23 by the above-described known position control means. Image recording can also be performed on various recording media.

  As described above, since the moving cam 37 reciprocates in the direction of the drum shaft 26, the four recording heads 10 can be simultaneously moved in the radiation direction of the drum shaft 26 along the guide long holes 31 of the guide plate 27. When performing image recording on recording media having different thicknesses, a predetermined gap can be maintained between the drum 23 (the recording surface of the recording medium on which the image is recorded) and the recording head 10.

  That is, since the flying distance (time) of the ink ejected from each recording head 10 can be made constant with respect to the recording medium conveyed by the drum 23 at a predetermined speed, the ink is landed at the same desired position. Image quality deterioration due to landing deviation can be eliminated.

  Further, since each recording head 10 moves in the radiation direction of the drum shaft 26 along the guide long hole 31 of the guide plate 27, the ejection direction of the ink that is always ejected from the recording head is orthogonal to the drum 23. Therefore, even if the gap between the drum 23 and the recording head 10 changes according to the thickness of the recording medium, the ink can be landed vertically on the recording medium.

FIG. 5 is a diagram illustrating an example of a moving mechanism for moving the recording head up and down relative to the drum in the ink jet recording apparatus according to the second embodiment.
In the first embodiment described above, the recording head is moved in the radiation direction of the drum shaft by the moving cam and the lifting member. In this embodiment, the recording head is moved in the radiation direction of the drum shaft by the lifting pinion gear and the lifting rack gear.

  The overall configuration and maintenance operation of the ink jet recording apparatus including the recording head, maintenance unit, guide mechanism, and the like in this example are the same as those described in the first embodiment.

An elevating pinion gear 39 is disposed on the drum shaft 26. Four lift rack gears 41 are engaged with the lift pinion gear 39.
The lifting rack gear 41 is arranged in parallel to the longitudinal direction of the guide long hole 31 with which the guide engaging pin 15 of each recording head 10 is engaged. And it is supported so that the movement to the longitudinal direction is possible.

The lifting rack gear 41 is provided with a contact portion 42. The guide engaging pin 15 on the lower side of the recording head 10 that engages with the guide long hole 31 is in contact with the contact portion 42.
When the elevating pinion gear 39 rotates forward and backward, the elevating rack gear 41 moves back and forth along the longitudinal direction of the guide slot 31, that is, in the radiation direction of the drum shaft 26.

  At this time, the contact portion 42 is in contact with the guide engagement pin 15, thereby enabling the recording head 10 to linearly advance and retract in the radiation direction.

FIG. 6 is a diagram illustrating an example of a moving mechanism for moving the recording head up and down relative to the drum in the ink jet recording apparatus according to the third embodiment.
In the first embodiment, the recording head is moved in the radiation direction of the drum shaft by the moving cam and the lifting member. In this embodiment, the recording head is moved in the radiation direction of the drum shaft by the wire and the pulley.

  The overall configuration and maintenance operation of the ink jet recording apparatus including the recording head, maintenance unit, guide mechanism, and the like in this example are the same as those described in the first embodiment.

  In this example, a small pulley 43 is rotatably fitted to the guide engaging pin 15 on the lower side of each recording head 10 that engages with each guide long hole 31. In this example, only three guide long holes 31 are shown for the sake of simplicity.

  In this example, pulleys 44 (44-1, 44-2, 44-3) are further provided on a main unit frame (not shown) between the recording heads 10 and on the right side of the recording head 10 at the right end. (In reality, there are four recording heads 10, so there are also four pulleys 44).

A wire 45 is wound around these pulleys 44. One end of the wire 45 is fixed to the main body frame by a fixing portion 46.
The other end of the wire 45 is wound and fixed on the circumference of a winding / sending pulley 47 connected to the rotating shaft 46 of the motor. The winding / feeding pulley 47 is also fixed to the main unit frame.

  When the recording head 10 is moved away from the drum 23 in the radiation direction, the motor is rotated in the clockwise direction in the figure. As a result, the wire 45 is wound on the circumference of the winding / sending pulley 47.

  Then, the length of the wire 45 between the fixed portion 46 and the take-up / feeding pulley 47 is shortened, and accordingly, the guide engaging pin 15 is lifted in a direction away from the drum 23 in the radial direction. Thereby, the position of the recording head 10 can be moved from the drum 23 in the radiation direction.

  When the position of the recording head 10 is moved in the radiation direction close to the drum 23, the winding / sending pulley 47 is rotated counterclockwise in the drawing. As a result, the wire 45 is fed out from the circumference of the winding / sending pulley 47.

  Then, the length of the wire 45 between the fixed portion 46 and the winding / sending pulley 47 becomes longer, and accordingly, the guide engagement pin 15 is lowered in the radiation direction close to the drum 23. Thereby, the position of the recording head 10 can be moved in the radiation direction close to the drum 23.

  Needless to say, the combination of the timing belt and the timing belt pulley is not limited to the combination of the wire 45 and the pulley 44.

FIGS. 7A and 7B are diagrams illustrating an example of a moving mechanism for moving the recording head up and down relative to the drum in the ink jet recording apparatus according to the fourth embodiment.
In the first embodiment, the recording head is moved in the radiation direction of the drum shaft by the moving cam and the lifting member. In this embodiment, the recording head is moved in the radiation direction of the drum shaft by the lifting cam.

In FIG. 2A, the relationship between the four recording heads 10 and the drum 23 shown in FIG.
The overall configuration and maintenance operation of the ink jet recording apparatus including the recording head, maintenance unit, guide mechanism, and the like in this example are the same as those described in the first embodiment.

  In this example, the four recording heads 10 shown in FIG. 7 (a) are moved by a lifting cam 48 shown in FIG. 7 (b). That is, the elevating cam 48 is rotatably supported coaxially with the rotating shaft (drum shaft 26) of the drum 23.

  The elevating cam 48 has a shape composed of five different radii R1, R2, R3, R4 and R5. First, there is a radius R1 portion for keeping the four recording heads 10 at the image recording position for a thin recording medium.

Next, there is a radius R2 portion for keeping the four recording heads 10 at image recording positions for thick recording media.
Then, there is a radius R3 portion that keeps the four recording heads 10 at the capping position. In addition, there is a radius R4 portion for keeping the four recording heads 10 at a position where wiping and cleaning maintenance is performed.

  Further, there is a radius R5 portion for keeping the four recording heads 10 at the retracted positions. Between these radii R1, R2, R3, R4 and R5, there is a relationship of R1 <R2 <R3 <R4 <R5.

  Further, the central angle of each sector of the radii Rl, R2, R3, R4, and R5 is θ, and the perpendicular from the center of the ink discharge surface of the recording head 10 at both ends to the center of the drum 23 (center of the drum shaft 26). Assuming that the angle formed by θ0 is θ0, there is a relationship of θ ≧ θ0.

  Any one of the five cam surfaces formed by the fan-shaped edge surfaces of the elevating cam 48 having the radius R1, R2, R3, R4 or R5 is always below the four recording heads 10. It abuts on the guide engaging pin 15 on the side.

  When the elevating cam 48 rotates, the radius from the center of the sector formed by the cam surface that contacts the guide engaging pin 15 of the recording head 10 changes. Thereby, the position of the recording head 10 relative to the drum 23 can be displaced in the radiation direction of the drum shaft 26.

Further, since θ ≧ θ0, the four recording heads 10 can always be kept on the same common cam surface (the position of the cam surface having the radius R3 in the example shown in FIG. 7B).
It should be noted that the above-described matters are descriptions and exemplifications of specific embodiments of the present invention. However, those skilled in the art will depart from the scope and technical idea of the present invention defined by the appended claims. However, various modifications and changes can be made to the present invention.

(a) is the perspective view which looked at the structure of the recording head used in the inkjet recording device of Example 1 from diagonally downward, (b) is the perspective view which looked at the structure of the maintenance unit from diagonally upward. (a) is a diagram illustrating a schematic configuration of the ink jet recording apparatus according to the first embodiment, (b) is a side view of the guide mechanism, and (c) and (d) are diagrams illustrating the function of the guide mechanism. (a)-(d) is a figure explaining the operation | movement at the time of maintaining the recording head in the structure of the inkjet recording device of Example 1. FIG. FIG. 3 is a diagram illustrating an example of a moving mechanism that moves a recording head up and down with respect to a drum in the ink jet recording apparatus according to the first exemplary embodiment. FIG. 6 is a diagram illustrating an example of a moving mechanism that moves a recording head up and down with respect to a drum in an ink jet recording apparatus according to a second embodiment. FIG. 6 is a diagram illustrating an example of a moving mechanism that moves a recording head up and down with respect to a drum in an ink jet recording apparatus according to a third embodiment. (a), (b) is a figure explaining the example of the moving mechanism which raises / lowers the recording head in the inkjet recording device of Example 4 with respect to a drum.

Explanation of symbols

10 (10k, 10c, 10m, 10y) Recording head 11 Head frame 12 Recording head module 13 Ink discharge nozzle 14 Guide engaging portion 15 Guide engaging pin 16 Maintenance unit 17 Maintenance portion 18 Maintenance frame 19 Holding member 21 Cap portion 22 Wiper Part 23 Drum 24 Maintenance device 25 Guide mechanism 26 Drum shaft 27 (27-1, 27-2) Guide plate 28 Stay 29 Engagement part 31 Guide long hole 32 Maintenance holding part 32u Upper surface 32d Lower surface 33 Rotation holding part 34 Lifting member 35 Contact part 36 Slope part 37 Moving cam 38 Slope part 39 Lift pinion gear 41 Lift rack gear 42 Contact part 43 Small pulley 44 (44-1, 44-2, 44-3) Pulley 45 Wire 46 Fixing part 46 Rotating shaft 47 Winding / feeding pulley 48 Lifting cam

Claims (4)

A drum capable of holding and rotating a recording medium on a cylindrical peripheral surface;
A recording head disposed so as to face the drum and have an ink ejection direction perpendicular to the peripheral surface of the drum;
A guide mechanism for guiding the recording head so as to linearly move along the ink ejection direction of the recording head between an image recording position close to the drum and a retracted position separated from the drum;
An ink jet recording apparatus comprising:   2. The ink jet recording apparatus according to claim 1, wherein the ink jet recording apparatus further includes a moving mechanism that allows the recording head to move to an image recording position close to the drum and a retracted position separated from the drum. Recording device.   The image recording positions are provided at a plurality of positions along the ink ejection direction in order to maintain different predetermined gaps for the plurality of types of recording media having different thicknesses during image recording. The ink jet recording apparatus according to claim 1 or 2. The guide mechanism includes an engaging portion that engages with a rotating shaft of the drum, and a guide portion that is linearly arranged in a radiation direction around the engaging portion,
The recording head includes an engaging member for engaging with the guide portion and keeping the linear movement posture constant.
The inkjet recording apparatus according to claim 1.