JP2012121185A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem of complexity of a mechanism for adjusting the height of a carriage in conjunction with the movement of the carriage.SOLUTION: A rotary member 401 with a main scanning direction as its rotation axis is provided in the carriage 4 so as to be freely rotated. The rotary member 401 comprises: a cam member 502 with a slide face 512 disposed in contact with the guide face 301 of a guide member 3 to freely slide over the guide face 301; and first and second rotation guide members 503 and 504 with contact faces 513 and 514 formed obliquely along the main scanning direction. The slide face 512 of the cam member 502 changes in distance between the rotation axis and the guide face 301 of the guide member 3 according to a rotated position. First and second pressing members 603 and 604 capable of coming into contact with the contact faces 513 and 514 of the first and the second rotation guide members 503 and 504 are arranged at both ends in the main scanning direction.

Description

  The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus including a carriage on which image forming means is mounted.

  As an image forming apparatus such as a printer, a facsimile, a copying machine, a plotter, or a complex machine of these, for example, a liquid discharge recording type image forming using a recording head composed of a liquid discharge head (droplet discharge head) that discharges ink droplets. As an apparatus, an ink jet recording apparatus or the like is known. This liquid discharge recording type image forming apparatus means that ink droplets are transported from a recording head (not limited to paper, including OHP, and can be attached to ink droplets and other liquids). Yes, it is also ejected onto a recording medium or a recording medium, recording paper, recording paper, etc.) to form an image (recording, printing, printing, and printing are also used synonymously). And a serial type image forming apparatus that forms an image by ejecting liquid droplets while the recording head moves in the main scanning direction, and a line type head that forms images by ejecting liquid droplets without moving the recording head There are line type image forming apparatuses using

  In the present application, the “image forming apparatus” of the liquid discharge recording method is an apparatus that forms an image by discharging liquid onto a medium such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics, or the like. In addition, “image formation” means not only giving an image having a meaning such as a character or a figure to a medium but also giving an image having no meaning such as a pattern to the medium (simply It also means that a droplet is landed on a medium). “Ink” is not limited to ink, but is used as a general term for all liquids capable of image formation, such as recording liquid, fixing processing liquid, and liquid. DNA samples, resists, pattern materials, resins and the like are also included. In addition, the “image” is not limited to a planar image, and includes an image given to a three-dimensionally formed image and an image formed by three-dimensionally modeling a solid itself. In addition, the present invention is not limited to the one having a recording head composed of a liquid ejection head as the image forming means, but will be described below with a liquid ejection type image forming apparatus.

  In such an image forming apparatus, since the gap (gap) between the nozzle surface of the recording head and the recording medium (medium conveying surface) affects the droplet landing position accuracy, the gap is set according to the thickness of the recording medium. It is known to include a gap adjusting mechanism (also referred to as a carriage height adjusting mechanism) for adjusting.

  In this case, there is one that includes a drive source for driving the gap adjustment mechanism (Patent Document 1). In addition, the first abutting portion provided on the carriage and the second abutting portion that is accommodated and protruded according to the scanning direction of the carriage, the first abutting the second abutting portion on the frame side is switched. And a second pressing means, wherein the first contact portion or the second contact portion is selectively slidably contacted with the frame to change the carriage posture and adjust the gap (Patent Document 2). )

JP 2005-103835 A JP 2004-322515 A

  As disclosed in Patent Document 1 described above, when an independent drive source for driving the gap adjusting means is provided, there is a problem that the configuration becomes complicated and the cost increases. Although this point can be solved by providing means for mechanically changing the posture of the carriage by moving and scanning the carriage as disclosed in Patent Document 2, there is a problem that the mechanical configuration becomes complicated.

  The present invention has been made in view of the above problems, and an object thereof is to enable gap adjustment with a simple configuration.

In order to solve the above problems, an image forming apparatus according to the present invention provides:
A carriage mounted with image forming means and moving in the main scanning direction;
A guide member having a support surface for slidably guiding the carriage,
The carriage is rotatably provided with a rotating member having a main scanning direction as a rotation axis,
The rotating member is
A cam member having a sliding surface slidably contacting the support surface of the guide member;
A rotation guide member having a contact surface formed obliquely along the main scanning direction,
The sliding surface of the cam member changes the distance between the rotation axis and the support surface of the guide member according to the rotational position,
At the end in the main scanning direction, a pressing member that can contact the contact surface of the rotation guide member is disposed,
By moving the carriage toward the pressing member, the contact surface of the rotation guiding member is pressed by the pressing member, the rotating member rotates, and the cam member rotates, so that the guide of the carriage The height position of the member relative to the support surface is changed.

Here, the rotation member includes a first rotation guide member having a contact surface that rotates in a first rotation direction, and a contact surface that rotates in a second rotation direction opposite to the first direction. A second rotation induction member having
A first pressing member capable of contacting the contact surface of the first rotation guide member is provided at one end portion in the main scanning direction, and a contact surface of the second rotation guide member is contacted at the other end portion. A possible second pressing member is provided,
When the carriage is moved toward the first pressing member, the rotating member rotates in the first rotating direction, and the height position of the carriage with respect to the support surface of the guide member is increased, and the carriage is moved. When the second pressing member is moved, the rotating member rotates in the second rotating direction, and the height position of the carriage with respect to the support surface of the guide member is lowered.

  In this case, the inclination of the contact surface of the first rotation induction member can be made gentler than the inclination of the contact surface of the second rotation induction member.

Further, the sliding surface of the cam member
A first sliding contact portion where the distance between the rotation axis and the support surface is a first distance; and a second sliding contact portion which is a second distance shorter than the first distance;
The first sliding contact portion and the second sliding contact portion may be formed on a flat surface in the circumferential direction.

  In this case, it can be set as the structure by which the recessed part is formed in the said 1st, 2nd sliding contact part of the said cam member.

  According to the image forming apparatus of the present invention, the carriage is rotatably provided with a rotating member having the rotation axis as the main scanning direction, and the rotating member is slidably in contact with the support surface of the guide member. A cam member having a surface and a rotation guide member having an abutment surface formed obliquely along the main scanning direction, and the sliding surface of the cam member has a rotation axis and a guide member according to the rotation position. The distance from the support surface changes, and at the end in the main scanning direction, a pressing member that can contact the contact surface of the rotation guiding member is arranged, and the carriage is moved to the pressing member side, thereby rotating the guide Since the contact surface of the member is pressed by the pressing member, the rotating member rotates and the cam member rotates, the height position of the carriage with respect to the support surface of the guide member changes. Can be adjusted.

1 is an external perspective view illustrating an example of an image forming apparatus according to an embodiment of the present invention. It is principal part plane explanatory drawing of the mechanism part of the apparatus. It is a principal part perspective explanatory drawing of a mechanism part similarly. It is side surface explanatory drawing of a carriage part similarly. FIG. 6 is a front perspective view of the carriage portion. Similarly, it is front explanatory drawing of a carriage part. It is side explanatory drawing with which it uses for description of a cam member. It is front explanatory drawing with which it uses for description of a rotation induction member. It is side surface explanatory drawing which shows the other example of a cam member. It is side surface explanatory drawing which shows the further another example of a cam member. It is side surface explanatory drawing used for description of other embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. An outline of an example of an image forming apparatus according to the present invention will be described with reference to FIGS. FIG. 1 is an external perspective view of the image forming apparatus, and FIG. 2 is a plan view of the mechanism of the apparatus.

  This image forming apparatus is a serial type image forming apparatus, and a cover 101 is provided on the upper surface side of the apparatus main body 100 so as to be openable and closable. By opening the cover 101, an internal mechanism unit can be accessed.

  As shown in FIG. 2, the mechanism unit supports the carriage 4 slidably in the main scanning direction by a guide member 3 which is a guide member horizontally mounted on the left and right main side plates 1 </ b> A and 1 </ b> B. The carriage 4 is moved and scanned in the main scanning direction via a timing belt 8 stretched between the driving pulley 6 and the driven pulley 7.

  The carriage 4 is supplied with a liquid discharge head as an image forming unit that discharges yellow (Y), cyan (C), magenta (M), and black (K) droplets, and ink is supplied to the liquid discharge head. A recording head unit (hereinafter also simply referred to as “recording head”) 11 including a head tank is arranged in a sub-scanning direction orthogonal to the main scanning direction, and a droplet discharge direction is directed downward. Wearing. The plurality of recording heads 11 are unitized by being held by a head holder (not shown) and mounted on the carriage 4.

  An encoder scale 15 is arranged along the main scanning direction of the carriage 4, and an encoder sensor 16 composed of a transmissive photosensor that reads the scale (scale: position identification unit) of the encoder scale 15 is attached to the carriage 4 side. The encoder scale 15 and the encoder sensor 16 constitute a linear encoder as a position detection device.

  On the other hand, below the carriage 4 is disposed a conveyance belt 21 as a conveyance unit that conveys a sheet (not shown) in the sub-scanning direction. The transport belt 21 is an endless belt, is stretched between the transport roller 22 and the tension roller 23, and the transport roller 22 is rotationally driven by the sub-scanning motor 31 via the timing belt 32 and the timing pulley 33. Thus, it is moved around in the sub-scanning direction.

  Further, a maintenance / recovery mechanism 41 that performs maintenance / recovery of the recording head 11 is disposed on the side of the conveyance belt 21 on one side of the carriage 4 in the main scanning direction. The maintenance / recovery mechanism 41 includes, for example, a cap member for capping the nozzle surface (surface on which the nozzle is formed) of the recording head 11, a wiper member for wiping the nozzle surface, and an empty discharge receiver for discharging liquid droplets that do not contribute to image formation. Etc.

  Further, as shown in FIG. 1, a sheet on which an image is formed by adhering liquid ejected from a recording head 11 serving as an image forming unit or a sheet feeding unit that feeds a sheet to the conveyance belt 21 is discharged. A paper supply / discharge tray 103 constituting paper discharge means and the like is detachably attached to the apparatus main body 100.

  In the image forming apparatus configured as described above, the fed paper is intermittently transported by the transport belt 21 and the recording head 11 is driven according to the image signal while moving the carriage 4 in the main scanning direction. In this manner, droplets are ejected onto the stopped paper to record one line, and after the paper is conveyed by a predetermined amount, the operation for recording the next line is repeated to form an image on the paper. The paper is ejected.

  Next, a carriage support structure and a height adjustment mechanism in this image forming apparatus will be described with reference to FIGS. 3 is a perspective view of the main part of the mechanism, FIG. 4 is a side view of the carriage, FIG. 5 is a front perspective of the carriage, and FIG. 6 is a front view of the carriage. .

  The guide member 3 is made of a sheet metal member, and includes a guide surface 301 and guide surfaces 302 and 303 that serve as support surfaces for slidably guiding the carriage 4. The carriage 4 includes a sliding portion 401 including a height adjustment mechanism slidably supported on the guide surface 301 of the guide member 3, a sliding portion 402 slidably contacting the guide surface 302, and a guide surface 303. And a sliding portion 403 in sliding contact. In this case, the guide surface 301 of the guide member 3 is a surface that determines the height position of the carriage 4, the guide surface 302 is a surface that receives a moment due to the weight of the carriage 4 (rotation stopper), and the guide surface 303 is the surface of the carriage 4. This is a surface that determines the position in the sub-scanning direction.

  Here, on the sliding portion 401 of the carriage 4, a rotating member 501 having a rotation axis as the main scanning direction is rotatably held by four holding members 404 fixed to the carriage 4. The rotating member 501 is formed by two cam members 502 having sliding surfaces 512 that are slidably in contact with the guide surface 301 that is a support surface of the guide member 301, and an oblique curve along the main scanning direction. A first rotation guide member 503 having a contact surface (rotation guide surface, guide surface) 513, and a second contact surface (rotation guide surface, guide surface) 514 formed obliquely along the main scanning direction. A rotation guide member 504 is provided.

  As shown in FIG. 7, the cam member 502 has a sliding surface 512 in which the distance between the rotation axis 511 and the guide surface 301 of the guide member 3 varies between the distance a and the distance b according to the rotational position. is doing. In this case, as shown in FIG. 7A, when the portion (this is referred to as “second sliding contact portion”) 502a that is the distance a of the sliding surface 512 of the cam member 502 is in contact with the guide surface 301, The carriage 4 is at a low height, and as shown in FIG. 7B, a portion (this is referred to as a “first sliding contact portion”) 502b that becomes the distance b of the sliding surface 512 of the cam member 502 is a guide surface. When in contact with 301, the carriage 4 is at a high height.

  The first rotation guide member 503 rotates the cam member 502 from the position of FIG. 7A to the position of FIG. 7B, that is, raises the carriage 4 with respect to the guide surface 301 (the gap becomes wider). It is a member that induces rotation of the rotating member 501 in the direction. The second rotation guiding member 504 rotates the cam member 502 from the position of FIG. 7B to the position of FIG. 7A, that is, lowers the carriage 4 with respect to the guide surface 301 (the gap becomes narrow). It is a member that induces rotation of the rotating member 501 in the direction.

  Further, as shown in FIG. 8, the contact surface 513 of the first rotation guide member 503 and the contact surface 514 of the second rotation guide member 504 are inclined with respect to the contact surface 513 of the first rotation guide member 503. The inclination of the contact surface 514 of the second rotation guiding member 504 is made gentler. That is, since the rotation member 501 rotates by the same angle, the first rotation guide member 503 needs to move the distance Lb, whereas the second rotation guide member 504 needs to move the distance La (La <Lb). It is.

  As a result, when the movement speed of the carriage 4 is the same, the adjustment operation is performed when the carriage 4 is lifted for a longer time than when the carriage 4 is lowered. This is because when the carriage 4 is raised, the carriage 4 is lifted against the dead weight of the carriage 4 so that the carriage 4 is raised slowly.

  On the other hand, on the side plate 1A (one end of the carriage main scanning direction) of the apparatus main body 1, a first pressing member 603 capable of contacting the contact surface 513 of the first rotation guiding member 503 is disposed, and the side plate 1B (carriage main scanning). A second pressing member 604 capable of contacting the contact surface 514 of the second rotation guiding member 504 is disposed at the other end in the scanning direction.

  In this case, since the second rotation guiding member 504 and the second pressing member 604 are disposed on the side where the maintenance / recovery mechanism 41 is disposed, that is, on the home position side of the carriage 3, the carriage 3 is moved to the home position. In some cases, the carriage 3 is returned to the low height position, and the maintenance and recovery mechanism 41 can be reliably capped by a cap member (not shown).

  With this configuration, in FIG. 6, the carriage 4 is moved in the direction of arrow A, and the contact surface 513 of the first rotation guiding member 503 is brought into contact with and pressed against the first pressing member 603. The member 501, that is, the cam member 502 rotates to the state shown in FIG. 7B and moves to a position where the first sliding contact portion 512 b of the sliding surface 512 contacts the guide surface 301 of the guide member 3. Rises and the height increases, and the gap (distance between the nozzle surface of the recording head 11 and the sheet conveyance surface by the conveyance belt 21) increases.

  On the other hand, in FIG. 6, the carriage 4 is moved in the direction indicated by the arrow B, and the abutting surface 514 of the second rotation guiding member 504 is brought into contact with and pressed against the second pressing member 604. The member 502 rotates to the state shown in FIG. 7A, moves to a position where the distance a of the sliding surface 512 is in contact with the guide surface 301 of the guide member 3, and the carriage 4 descends to raise the height. Lowering and narrowing the gap.

  In this way, the carriage 4 is moved up and down only by the movement of the carriage 4 to change the gap (the gap is adjusted).

  As described above, the carriage is rotatably provided with a rotation member having the main scanning direction as the rotation axis, and the rotation member includes a cam member having a sliding surface slidably contacting the support surface of the guide member; A rotation guide member having an abutment surface formed obliquely along the main scanning direction, and the sliding surface of the cam member has a distance between the rotation axis and the support surface of the guide member according to the rotational position. The pressing member that can be brought into contact with the contact surface of the rotation guiding member is arranged at the end in the main scanning direction, and the contact surface of the rotation guiding member is pressed by moving the carriage to the pressing member side. The gap can be adjusted with a simple configuration by adopting a configuration in which the height position of the carriage guide member relative to the support surface is changed by the rotation of the rotating member when pressed by the member and the rotation of the cam member. .

Next, another example of the cam member 502 will be described with reference to FIG. FIG. 9 is an explanatory side view of the cam member.
Of the sliding surface 512 of the cam member 502, the first sliding contact portion 512b in which the distance between the rotation axis and the support surface (guide surface 301) is the first distance b, and the second longer than the first distance b. Each of the second sliding contact portions 512a having a distance a is formed on a flat surface in the circumferential direction.

  As a result, the contact area between the first and second sliding contact portions 512b and 512a of the cam member 502 and the guide surface 301 of the guide member 3 is increased, and the sliding of the carriage 4 is further stabilized.

Next, still another example of the cam member 502 will be described with reference to FIG. FIG. 10 is an explanatory side view of the cam member.
Here, a recess 505 is formed in the first and second sliding contact portions 512b and 512a of the cam member 502. Providing the concave portion 505 reduces the sliding load, and filling the concave portion 505 with a lubricant such as grease makes it possible to reduce the sliding load.

Next, another embodiment of the present invention will be described with reference to FIG.
Here, a stopper member 510 that restricts the rotational position of the cam member 502 is provided. In this example, the cam member 502 is described as being rotated 90 degrees, but the present invention is not limited to this example. Thereby, the cam member 502 is restricted from rotating beyond a predetermined position, and the height position adjustment of the carriage 4 is stabilized.

  In the above embodiment, the present invention has been described with reference to an example in which the present invention is applied to an image forming apparatus having a printer configuration. However, the present invention is not limited to this. For example, the present invention may be applied to an image forming apparatus such as a printer / fax / copier multifunction machine. it can. Further, the present invention can be applied to an image forming apparatus using a liquid other than the narrowly defined ink, a fixing processing liquid, a patterning material, and the like.

3 Guide members (guide members)
4 Carriage 11 Recording head 301 Guide surface (support surface)
302, 303 Guide surfaces 401, 402, 403 Sliding part 501 Rotating member 502 Cam member 503 First rotation guiding member 504 Second rotation guiding member 603 First pressing member 604 Second pressing member

Claims (5)

A carriage mounted with image forming means and moving in the main scanning direction;
A guide member having a support surface for slidably guiding the carriage,
The carriage is rotatably provided with a rotating member having a main scanning direction as a rotation axis,
The rotating member is
A cam member having a sliding surface slidably contacting the support surface of the guide member;
A rotation guide member having a contact surface formed obliquely along the main scanning direction,
The sliding surface of the cam member changes the distance between the rotation axis and the support surface of the guide member according to the rotational position,
At the end in the main scanning direction, a pressing member that can contact the contact surface of the rotation guide member is disposed,
By moving the carriage toward the pressing member, the contact surface of the rotation guiding member is pressed by the pressing member, the rotating member rotates, and the cam member rotates, so that the guide of the carriage An image forming apparatus, wherein a height position of a member with respect to a support surface changes. The rotation member includes a first rotation guide member having a contact surface that rotates in a first rotation direction, and a contact surface that rotates in a second rotation direction opposite to the first direction. 2 rotation induction members are provided,
A first pressing member capable of contacting the contact surface of the first rotation guide member is provided at one end portion in the main scanning direction, and a contact surface of the second rotation guide member is contacted at the other end portion. A possible second pressing member is provided,
When the carriage is moved toward the first pressing member, the rotating member rotates in the first rotating direction, and the height position of the carriage with respect to the support surface of the guide member is increased, and the carriage is moved. The height position of the carriage with respect to the support surface of the guide member is lowered when the rotary member is moved to the second pressing member side and the rotary member rotates in the second rotational direction. The image forming apparatus according to 1.   The image forming apparatus according to claim 2, wherein the inclination of the contact surface of the first rotation induction member is gentler than the inclination of the contact surface of the second rotation induction member. On the sliding surface of the cam member,
A first sliding contact portion where the distance between the rotation axis and the support surface is a first distance; and a second sliding contact portion which is a second distance shorter than the first distance;
The image forming apparatus according to claim 1, wherein the first sliding contact portion and the second sliding contact portion are formed on a flat surface in the circumferential direction.   The image forming apparatus according to claim 4, wherein a concave portion is formed in the first and second sliding contact portions of the cam member.

Images