JP2009208376A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that a main guide member using an inverted V-shaped sheet metal drops as a result of applying a lubricant to a sliding part, with the result that the shape of the bearing of a carriage is limited and a change in the shape of the carriage is required when the angle of the receiving face of the main guide member needs to be changed, and accordingly this member is insufficient for wide use. <P>SOLUTION: The image forming apparatus includes: the carriage 13 having a recording head 14 mounted thereon; a main guide member 11 that guides the carriage 13 so that it freely slides; and a sub-guide member 12 that prevents rotation of the carriage 13 with respect to the main guide member 11. The main guide member 11 is V-shaped guide rail having a V-shaped sectional shape. The sliding part 31 of the carriage 13 is supported by the V-shaped guide rail 11 at two points, thereby reducing backlash. The main guide member 11 can be used as a lubricant receptacle, and can be optimized simply by inclining the V-shape guide rail 11 without changing the shape of the carriage 13. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

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 machine, a copying machine, a plotter, and a complex machine of these, for example, an ink jet recording apparatus using a recording head for ejecting ink droplets as an image forming means 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, “image forming apparatus” means an apparatus that discharges droplets onto a medium such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics, etc. “To not only give an image having a meaning such as a character or a figure to a medium, but also to give an image having no meaning such as a pattern to the medium (simply causing a droplet to land on the medium). Also means. “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 and the like are also included.

  As such an image forming apparatus, a recording head as an image forming unit is mounted on a carriage, the carriage is moved and scanned in the main scanning direction, and the paper is moved intermittently in the sub-scanning direction orthogonal to the main scanning direction. A serial type image forming apparatus that forms an image with a recording head is known. In the following description, the recording head as the image forming unit is described as an example of a liquid discharge head. However, the image forming unit is not limited to the liquid discharge head, and the present invention may be applied to other image forming units. Can be applied as well.

  In such a serial type image forming apparatus, as a main guide member for slidably guiding a carriage, a guide rod having a circular cross section as shown in FIG. However, it is known that troubles such as color misalignment in the sub-scanning direction and ruled line print misalignment between different heads occur due to the clearance (backlash) between the carriage bearing 502 and the guide rod 501. In particular, when the head is long, the ruled line printing misalignment due to “backlash” may be a problem.

  Therefore, for example, it is known to reduce the occurrence of play by setting the shape of the carriage bearing to a “C” shape. Moreover, as shown in FIG. 9, it is also known to use a guide member 503 formed of “inverted V-shaped metal plate” (see Patent Document 2).

JP 2004-255758 A JP 2006-095797 A

  However, in the configuration in which the above-described conventional “inverted V-shaped sheet metal” is used as the main guide member, when the lubricant (grease) is applied to the sliding portion, the grease drops, and the carriage side However, there is a problem that the shape of the bearing surface is not versatile because it is necessary to change the shape on the carriage side when it is desired to change the angle of the receiving surface in accordance with the carriage configuration (weight balance).

  The present invention has been made in view of the above-described problems. With a simple configuration, the lubricant can be applied while reducing the backlash of the carriage, increasing the degree of freedom in designing the carriage, and improving the durability of the carriage. The purpose is to improve the stability of performance and behavior.

In order to solve the above problems, an image forming apparatus according to the present invention provides:
A carriage mounted with a recording head;
A main guide member for slidably guiding the carriage;
A sub guide member for preventing rotation of the carriage with respect to the main guide member,
The main guide member has a V-shaped cross section.

  Here, a belt member that transmits a driving force to the carriage passes through a sliding portion that contacts the main guide member of the carriage. The main guide member may be supported so that the mounting angle can be changed. In addition, an eccentric cam is provided in a sliding portion that contacts the main guide member of the carriage, and the eccentric cam can be configured to slidably contact the main guide member.

  According to the image forming apparatus of the present invention, since the main guide member that slidably guides the carriage is a member having a V-shaped cross section, lubrication can be achieved with a simple configuration while reducing the backlash of the carriage. The agent can be applied, the degree of freedom in designing the carriage side can be increased, and the durability and behavioral stability of the carriage can be improved.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. First, an example of an image forming apparatus according to the present invention provided with a position detection device according to the present invention including an encoder sheet according to the present invention will be described with reference to FIGS. 1 and 2. 1 is an explanatory perspective view of a mechanism portion of the image forming apparatus, and FIG. 2 is an explanatory side view of a carriage portion.

  This image forming apparatus is a serial type image forming apparatus, and is formed of a sheet metal having a V-shaped cross-section, which is a main guide member horizontally mounted on the left and right side plates 2A, 2B standing on the base member 1. The carriage 13 is slidably held in the main scanning direction (arrow X direction) by the character guide rail 11 and the slide rail 12 (see FIG. 2) which is a sub guide member.

  A timing belt 8 stretched between a driving pulley 6 and a driven pulley 7 which are rotationally driven by the main scanning motor 5 is fixed to the carriage 13 by a belt clamp 9 on the back side. By driving 5, the carriage 13 is moved and scanned in the main scanning direction.

  The carriage 13 has a liquid discharge head as image forming means for discharging liquid droplets of yellow (Y), cyan (C), magenta (M), and black (K), and a recording liquid to the liquid discharge head. The recording head units 14a, 14b including the head tank to be supplied (referred to as “recording head unit 14” when not distinguished from each other) are arranged in a sub-scanning direction (arrow Y direction) perpendicular to the main scanning direction in a nozzle row composed of a plurality of nozzles. Are mounted with the droplet discharge direction facing downward.

  Each of the recording heads 14 has two nozzle arrays. One nozzle array of the recording head 14a has black (K) droplets, the other nozzle array has cyan (C) droplets, and the recording head 14b One nozzle row ejects magenta (M) droplets, and the other nozzle row ejects yellow (Y) droplets.

  On the other hand, below the carriage 13, a transport belt 21 is disposed as a transport unit that transports 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 is rotated by a sub-scan motor (not shown) to rotate in the sub-scanning direction (indicated by an arrow). Y direction).

  Although not shown, a paper feeding unit that feeds the paper to the conveyance belt 21 and a paper discharging unit that discharges the paper on which an image is formed by the liquid ejected from the recording head unit 14 serving as an image forming unit being attached. And so on.

  In this image forming apparatus configured as described above, a sheet fed from a sheet feeding unit (not shown) is intermittently conveyed by the conveying belt 21 and recorded in accordance with an image signal while moving the carriage 13 in the main scanning direction. By driving the liquid discharge head of the head unit 14, a droplet is discharged onto a stopped sheet to record one line, and after the sheet is conveyed by a predetermined amount, the operation for recording the next line is repeated. An image is formed on the paper, and the paper is discharged after the image is formed.

  Here, the image forming apparatus includes a V-shaped guide rail 11 that slidably holds the carriage 3 as shown in FIG. 2, and the cross-sectional shape provided on the carriage 3 is a substantially semicircular slide. A moving part (bearing equivalent part) 31 is slidably mounted on the V-shaped guide rail 11. At this time, the sliding portion 3 of the carriage 3 abuts against the two receiving surfaces 11a of the V-shaped guide rail 11 and is supported at two points, so that there is no backlash between the carriage 3 and the V-shaped guide rail 11 (or Reduced). The rotation of the carriage 3 around the V-shaped guide rail 11 is restricted by a slide rail 12 that is a sub guide member.

  As described above, the main guide member that slidably guides the carriage is a member having a V-shaped cross section. Therefore, a lubricant is applied as described later while reducing the backlash of the carriage with a simple configuration. Even if it does not drop, the degree of freedom in designing the carriage can be increased, and the durability and behavioral stability of the carriage can be improved.

Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 3 is an explanatory side view of the carriage portion in the same embodiment.
In this embodiment, the bottom of the V-shaped guide rail 11 is used as a grease reservoir, and the grease 32 is accumulated. This is made possible by using the V-shaped guide rail 11, and a grease reservoir cannot be provided with an inverted V-shaped guide member as in the prior art. Since the grease can be used in this way, durability can be improved, and moving scanning can be performed stably over a long period of time.

Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 4 is an explanatory side view of the carriage portion in the same embodiment.
In this embodiment, a hollow portion 33 is formed in the sliding portion 31 of the carriage 13 along the main scanning direction, and a belt member that transmits a driving force for moving the carriage 13 into the hollow portion 33, for example, the timing belt described above. The timing belt 8 is attached to the carriage 13 by being clamped by the belt clamp 9. The hollow sliding portion 31 is formed with a slit-shaped opening 31a for fitting the timing belt 8 along the main scanning direction.

  By using the V-shaped guide rail in this way, the degree of freedom in designing the carriage side is expanded. In particular, when the belt is passed through the sliding portion, the driving force of the carriage can be transmitted in the vicinity of the support portion of the carriage, and the behavior of the carriage can be stabilized.

Next, a fourth embodiment of the present invention will be described with reference to FIG. FIG. 5 is an explanatory side view of the carriage portion in the same embodiment.
In this embodiment, the shape of the sliding portion 31 that is slidably in contact with the V-shaped guide rail 11 of the carriage 3 is formed by cutting a part of a semicircular shape. That is, as long as the V-shaped guide rail 11 can be contacted at two points, the shape of the sliding portion may not be circular.

Next, a fifth embodiment of the present invention will be described with reference to FIG. FIG. 6 is an explanatory side view of the carriage unit in a different state according to the embodiment.
By holding the carriage 13 with the V-shaped guide rail 11 as described above, the backlash can be easily optimized without changing the shape of the carriage 13 even when the configuration of the carriage 13 is changed. That is, for example, when the weight of the carriage 13 changes and the position of the center of gravity moves to the front side, the V-shaped guide rail 11 in which the sliding portion 31 of the carriage 13 is slidably in contact as shown in FIG. As shown in FIG. 6B, the support balance may be improved by inclining by an angle θ (the surface with which the sliding portion 31 contacts: changing the angle of the receiving surface 11a).

  Therefore, the mounting angle of the V-shaped guide rail 11 can be changed. As a result, the play can be optimized without changing the shape on the carriage side, and a general-purpose design of the carriage becomes possible. At this time, if the rotation center of the V-shaped guide rail 11 is not changed, the head gap G between the head 14 of the carriage 13 and the transport surface 40 (for example, a platen member or a transport belt surface) is not changed.

Next, a sixth embodiment of the present invention will be described with reference to FIG. FIG. 7 is an explanatory side view of the carriage unit in a different state according to the embodiment.
In this embodiment, an eccentric cam 36 having a shaft 37 as a center of rotation is provided at a sliding portion slidably contacting the V-shaped guide rail 11 of the carriage 13, and the eccentric cam 36 is in contact with the V-shaped guide rail 11. Yes. Accordingly, by rotating the eccentric cam 36 by 180 ° from the state shown in FIG. 7A, the state shown in FIG. 7B is obtained, and the height of the carriage 13 with respect to the transport surface 40, that is, the head gap is set from the distance G1. The distance can be changed to G2 (G2 <G1).

  Thus, the head gap can be switched with a simple configuration, and the number of parts can be greatly reduced by providing the gap adjustment mechanism on the carriage side.

  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 recording liquid or a fixing processing liquid that is a liquid other than ink.

1 is an explanatory perspective view illustrating an example of an image forming apparatus according to a first embodiment of the present invention. It is side surface explanatory drawing of a carriage part similarly. It is side surface explanatory drawing of the carriage part in 2nd Embodiment of this invention. It is side surface explanatory drawing of the carriage part in 3rd Embodiment of this invention. It is side surface explanatory drawing of the carriage part in 4th Embodiment of this invention. It is side surface explanatory drawing which shows the different state of the carriage part in 5th Embodiment of this invention. It is side surface explanatory drawing which shows the different state of the carriage part in 5th Embodiment of this invention. It is sectional explanatory drawing which shows an example of the conventional main guide member. It is explanatory drawing which similarly shows another example.

Explanation of symbols

8 ... Timing belt 11 ... V-shaped guide rail 13 ... Carriage 14 ... Recording head unit 36 ... Eccentric cam 40 ... Conveying surface

Claims (4)

A carriage mounted with a recording head;
A main guide member for slidably guiding the carriage;
A sub guide member for preventing rotation of the carriage with respect to the main guide member,
An image forming apparatus, wherein the main guide member has a V-shaped cross section.   The image forming apparatus according to claim 1, wherein a belt member that transmits a driving force to the carriage passes through a sliding portion that contacts the main guide member of the carriage.   The image forming apparatus according to claim 1, wherein the main guide member is supported so that a mounting angle can be changed.   2. The image forming apparatus according to claim 1, wherein an eccentric cam is provided in a sliding portion of the carriage that contacts the main guide member, and the eccentric cam is slidably in contact with the main guide member. Image forming apparatus.

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