JP2008175714A - Encoder sheet, position detector, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem wherein a user can erroneously touch an encoder sheet in the working, because the encoder sheet is inconspicuous in an apparatus body, thereby resulting in defective detection. <P>SOLUTION: This encoder sheet 15 is configured, such that scales (lines) 32 are printed at a predetermined interval on a sheet-type base member 31 made of a light-transmissive film and a white line 33 for recognition of the encoder sheet 15 is printed in a line on the base member 31 at substantially the entire region of one end in the short side thereof. The presence or the position of the encoder sheet 15 can be readily recognized by the line 33, in a condition where the encoder sheet 15 is placed in the apparatus body. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an encoder sheet, a position detection device, and an image forming apparatus.

  As an image forming apparatus such as a printer, a facsimile machine, a copying machine, and a multifunction machine of these, for example, a recording head constituted by a liquid discharge head that discharges liquid droplets of a recording liquid (liquid) is provided as an image forming means, and a medium (hereinafter “ Although it is also referred to as “paper”, the material is not limited, and a recording medium (recording medium, recording medium, transfer material, recording paper, etc. is also used synonymously) and a recording liquid as a liquid (hereinafter also referred to as ink). Is used to form an image (recording, printing, printing, and printing are also used synonymously).

  The image forming apparatus means an apparatus for forming an image by discharging a liquid onto a medium such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics, etc. The term “not only” 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. Further, the liquid is not limited to the recording liquid and ink, and is not particularly limited as long as it is a liquid capable of forming an image. Further, the liquid ejecting apparatus means an apparatus that ejects liquid from liquid ejection.

  As such an image forming apparatus, a liquid discharge head as an image forming unit is mounted on a carriage, the liquid discharge head is moved and scanned in the main scanning direction, and the medium is moved intermittently in the sub-scanning direction orthogonal to the main scanning direction. In addition, there is known a serial type image forming apparatus that forms an image by ejecting liquid droplets from a liquid ejection head. In the following description, 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 is similarly applied to other image forming units. can do.

  In such a serial type image forming apparatus, a linear encoder (position detecting device) including an encoder scale arranged along a main scanning direction of a carriage on which a liquid discharge head is mounted, and an encoder sensor for reading the scale of the encoder scale. And detecting the position and speed of the carriage, and controlling the moving speed of the carriage, driving of the liquid ejection head, and the like based on the detection result.

As a conventional linear encoder, for example, in Patent Document 1, position information related to other functions is magnetized on another line of the scale unit, and the carriage has a plurality of color recording heads arranged in parallel. On the line, an encoder sheet on which position information is magnetized corresponding to the capping position of each color recording head is described.
Japanese Patent No. 3121679

Patent Document 2 describes an encoder including an encoder sensor that detects a scale pattern (scale) provided on an encoder scale, and an imaging unit that can recognize the shape of a mark that forms the scale pattern.
JP 2006-27146 A

In Patent Document 3, when replacing the carriage and encoder sensor, the linear sensor is not removed, and the encoder sensor is held in order to allow the operator to work without fear of touching it by hand. For this purpose, a sensor holding member for detachable in the vertical direction is described.
JP 2006-187905 A

  By the way, in general, the encoder sheet is installed in an exposed state inside the apparatus main body. In addition, the conventional encoder sheet is formed by printing a black fine line (scale) on a translucent base member (film member), and the visibility of the dim apparatus body is not high. Therefore, the recording liquid mist scattered on the encoder sheet may be attached, or the operator may accidentally contact the encoder sheet when jamming is performed, and oils and fats such as hand grease may adhere to the encoder sheet. is there.

  However, when the recording liquid adheres to the encoder sheet or oils and fats adhere, there is a problem that normal reading cannot be performed by the encoder sensor.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and has as its object to provide an encoder sheet that is particularly improved in visibility, a position detection device that includes this encoder sheet, and an image forming apparatus that includes this position detection device. And

  In order to solve the above-described problems, the encoder sheet according to the present invention is configured such that at least a part of the base member is colored.

  In the encoder sheet according to the present invention, the base member is a member that transmits light, the scale is a color scale that does not transmit light, and at least a part of the base member is colored.

  In the encoder sheet in which at least a part of the base member is colored, at least one of the short-side end portions of the base member may be colored in a line shape. It is preferable to adopt a configuration as described above. Further, the colored portion of the base member may be colored white. Further, the colored portion of the base member may be colored with a fluorescent paint or a phosphorescent paint. Further, the base member may be a color film.

  In the encoder sheet according to the present invention, the base member is a member that transmits light, and the scale is a color scale that does not transmit light.

  The position detection apparatus according to the present invention includes the encoder sheet according to the present invention.

  An image forming apparatus according to the present invention includes the position detection device according to the present invention. Here, the encoder sheet of the position detection device can be arranged along the moving direction of the image forming means.

According to the encoder sheet of the present invention, since at least a part of the base member is colored, the entire base member is easily noticeable and visibility is improved.
Is.

  According to the encoder sheet of the present invention, the base member is a member that transmits light, the scale is a color scale that does not transmit light, and at least a part of the base member is colored. The whole becomes conspicuous and the visibility is further improved.

  According to the encoder of the present invention, since the base member is a member that transmits light and the scale is a color scale that does not transmit light, the scale is easily noticeable and visibility is improved.

  According to the position detection device according to the present invention, since the encoder sheet according to the present invention is provided, the visibility of the encoder sheet is improved, so that it is possible to reduce erroneous contact with the encoder sheet.

  According to the image forming apparatus according to the present invention, since the position detection device according to the present invention is provided, the visibility of the encoder sheet of the position detection device is improved, so that erroneous contact with the encoder sheet can be reduced.

  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 a guide rod 11 which is a guide member horizontally mounted on the left and right side plates 2A and 2B provided upright on the base member 1, and a carriage by a slide rail 12 (see FIG. 2). 13 is slidably held in the main scanning direction (arrow X direction), and is moved and scanned in the main scanning direction via a timing belt by a main scanning motor (not shown).

  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.

  An encoder scale 15 is arranged along the main scanning direction of the carriage 13, and an encoder sensor 16 composed of a transmission type photosensor for reading the scale (scale) of the encoder scale 15 is attached to the rear side of the carriage 13. The scale 15 and the encoder sensor 16 constitute a linear encoder 17 as a position detection device.

  In addition, a flexible cable (FFC) 18 that transmits a drive signal to be supplied to the recording head unit 14 is provided. The FFC 18 is held by a pressing member 19 on the rear plate 3.

  On the other hand, below the carriage 13, a transport belt 21 is disposed as a transport unit that transports paper (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.

Therefore, a first embodiment of an encoder sheet according to the present invention, which is an encoder sheet 15 constituting a position detecting device in the image forming apparatus, will be described with reference to FIG.
The encoder sheet 15 is provided by printing scales (lines) 32 at a predetermined interval (not necessarily constant) on a sheet-like base member 31 made of a light-transmitting film. A white encoder sheet recognition line 33 is printed and formed in a line over substantially the entire area at one end of the hand direction.

  With this configuration, the encoder sheet 15 is easily noticeable by the recognition line 33 in a state where the encoder sheet 15 is arranged in the apparatus, and the position or shape of the encoder sheet 15 can be easily grasped. Visibility is improved. As a result, the possibility of erroneous contact with the encoder 15 when performing jam processing or the like can be reduced.

  Here, the width 41 of the encoder sheet 15 for main scanning is usually an elongated shape of about several mm to several tens mm, and the range 42 actually read by the encoder sensor 16 is often a narrower range. By forming the encoder sheet recognition line 33 at the end in the short direction as a region other than the range read by the encoder sensor 16, the encoder sensor 15 can be read without obstructing the reading of the scale 32 by the encoder sensor 16. Can be improved.

  Also, the encoder sheet recognition line, that is, the coloring is white, so that it can be printed with an inexpensive paint, and the presence of the encoder sheet in the apparatus becomes more conspicuous, and the shape of the encoder sheet The position can be easily grasped. Furthermore, by forming the encoder sheet recognition line 33, that is, coloring, with a luminescent paint, a fluorescent paint, or a phosphorescent paint, the presence of the encoder sheet in the apparatus becomes more conspicuous, and the shape or position of the encoder sheet is grasped. Becomes easier. Note that the encoder sheet recognition line need not be formed continuously over the entire area, but can be formed in a jumping manner.

Next, a second embodiment of the encoder sheet according to the present invention will be described with reference to FIG.
The encoder sheet 15 is provided with a color-printed scale (line) 33 that does not transmit light at a predetermined interval (not necessarily constant) on a sheet-like base member 31 made of a light-transmitting film. . That is, the scale 33 of light-impermeable color (color other than black) is provided.

  With this configuration, the color scales 34 are arranged at an extremely short interval, so that the entire encoder sheet 15 is colored in the color of the scale 34, and the encoder sheet 15 is arranged in the apparatus. In this state, the encoder sheet 15 is easily noticeable, the position or shape of the encoder sheet 15 is easily grasped, and the visibility of the encoder sheet 15 is improved. As a result, the possibility of erroneous contact with the encoder 15 when performing jam processing or the like can be reduced.

Next, a third embodiment of the encoder sheet according to the present invention will be described with reference to FIG.
The encoder sheet 15 is provided with a scale (line) 36 that does not transmit light at a required interval (not necessarily constant) on a sheet-like base member 35 made of a color film that transmits light.

  Thus, since the base member 35 itself of the encoder sheet 15 is made of a colored film, the encoder sheet 15 is easily noticeable in a state where the encoder sheet 15 is disposed in the apparatus, and the position or shape of the encoder sheet 15 is determined. And the visibility of the encoder sheet 15 is improved. As a result, the possibility of erroneous contact with the encoder 15 when performing jam processing or the like can be reduced.

  In the above embodiment, the liquid ejection apparatus according to the present invention has been described as an example applied to an image forming apparatus having a printer configuration. However, the present invention is not limited to this. For example, an image forming apparatus such as a printer / fax / copier multifunction machine is used. Can be applied to. 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 the present invention. It is side surface explanatory drawing of a carriage part similarly. It is a typical explanatory view showing a 1st embodiment of an encoder sheet concerning the present invention. It is a typical explanatory view showing a 2nd embodiment of an encoder sheet concerning the present invention. It is a typical explanatory view showing a 2nd embodiment of an encoder sheet concerning the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 13 ... Carriage 14 ... Recording head unit 15 ... Encoder sheet 16 ... Encoder sensor 17 ... Linear encoder (position detection apparatus)
31, 35 ... Base member 32, 36 ... Scale 33 ... Encoder sheet recognition line 34 ... Color scale

Claims (11)

  An encoder sheet, wherein the base member is graduated at a required interval, and at least a part of the base member is colored.   In an encoder sheet in which a scale is attached to a base member at a required interval, the base member is a member that transmits light, the scale is a color scale that does not transmit light, and at least a part of the base member is colored An encoder sheet characterized by being made.   3. The encoder sheet according to claim 1, wherein at least one of the short-side end portions of the base member is colored in a line shape. 4.   The encoder sheet according to claim 3, wherein at least one of the end portions in the short direction of the base member is colored over substantially the entire region.   5. The encoder sheet according to claim 1, wherein a colored portion of the base member is colored in white. 6.   6. The encoder sheet according to claim 1, wherein the colored portion of the base member is colored with a fluorescent paint or a phosphorescent paint.   The encoder sheet according to claim 1 or 2, wherein the base member is a color film.   An encoder sheet in which a scale is attached to a base member at a predetermined interval, wherein the base member is a member that transmits light, and the scale is a color scale that does not transmit light.   A position detection apparatus comprising an encoder sheet and an encoder sensor that reads the encoder sheet, wherein the encoder sheet is the encoder sheet according to any one of claims 1 to 8.   An image forming apparatus comprising an image forming means for forming an image, comprising the position detecting device according to claim 9.   The image forming apparatus according to claim 10, wherein the image forming unit is movably provided, and an encoder sheet of the position detecting device is arranged along a moving direction of the image forming unit. Forming equipment.

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