JP5811382B2 - Image reading apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to an image reading apparatus and an image forming apparatus.

  2. Description of the Related Art There is known an image reading apparatus that irradiates a document with a light source including a plurality of LED elements and reads an image of the document with light reflected from the document. Since it is known that the amount of light and the color tone of LED elements generally change depending on temperature, a proposal has been made to dissipate the heat of the LED elements used in such an image reading apparatus (for example, Patent Document 1). reference).

  The image reading apparatus described in Patent Document 1 includes an LED element that emits light for irradiating a document, and an image reading unit that reads an image of the document with reflected light that is reflected by the light from the LED element. The heat generated by the plurality of LED elements mounted on the front surface and the back surface is radiated by a heat conductive reflecting mirror having a function of condensing the luminous flux of the LED elements.

JP 2008-177918 A

An object of the present invention is to provide an image reading apparatus and an image forming apparatus capable of reducing the bending of a light guide during image reading.

[1] A plurality of light emitting elements that emit light for irradiating a document, and a substrate on which the plurality of light emitting elements are mounted, the substrate on which the plurality of light emitting elements are mounted along the longitudinal direction of the substrate And a first surface of the substrate on which the plurality of light emitting elements are mounted, the first surface contacting the portion where the plurality of light emitting elements are not mounted, and fixing the substrate, and the first surface A support member having a second surface arranged at a predetermined angle with respect to the light source, and the light from the plurality of light emitting elements is incident and guided in the direction of the document, and at least three protrusions are formed. A light guide, a pressing member that presses the light guide against the second surface, and a reading unit that reads an image of the document with reflected light reflected from the document by light emitted from the light guide. And at least one of the at least three protrusions Is formed at a location closer to the longitudinal center of the light guide than the other two projections, and the other two projections are positioned in the longitudinal direction of the light guide from the center across the center. The at least three protrusions are formed at locations close to both end faces of the body, and the position of the at least three protrusions is restricted with respect to the substrate and the support member, so that the light guide body is the first surface or the second surface. An image reading apparatus, wherein the image reading apparatus is held parallel to a surface .

[2] A plurality of light emitting elements that emit light for irradiating a document, and a substrate on which the plurality of light emitting elements are mounted, wherein the plurality of light emitting elements are mounted along the longitudinal direction of the substrate. And a light guide body on which light from the plurality of light emitting elements is incident and guided in the direction of the document and at least three protrusions are formed, and a surface of the substrate on which the plurality of light emitting elements are mounted. A first surface for contacting the portion where the plurality of light emitting elements are not mounted and fixing the substrate, and a second surface for supporting the light guide on the plurality of light emitting element sides when viewed from the substrate. A support member having a surface; a pressing member that presses the light guide against the support member; and a reading unit that reads an image of the document with reflected light reflected from the document by light emitted from the light guide. The pressing member includes the first surface and The light guide is pressed toward the second surface from a direction different from the intersecting direction, and one of the at least three protrusions is longer in the longitudinal direction of the light guide than the other two protrusions At least one of the other two protrusions is fitted into a slot formed in the second surface, and the one protrusion is the other two protrusions. The image reading apparatus is characterized in that the light guide is held in parallel to the first surface or the second surface by restricting the position at a position closer to the center.

[3] The image reading apparatus according to [1] or [2], wherein the light guide is pressed from a direction parallel to the protruding direction.

[4] A plurality of light emitting elements that emit light for irradiating a document, and a substrate on which the plurality of light emitting elements are mounted, wherein the plurality of light emitting elements are mounted along a longitudinal direction of the substrate. And a light guide body on which light from the plurality of light emitting elements is incident and guided in the direction of the document and at least three protrusions are formed, and a surface of the substrate on which the plurality of light emitting elements are mounted. A first surface for contacting the portion where the plurality of light emitting elements are not mounted and fixing the substrate, and a second surface for supporting the light guide on the plurality of light emitting element sides when viewed from the substrate. A support member having a surface, and a reading unit that reads an image of the document by reflected light reflected from the document by light emitted from the light guide, and at least one of the at least three protrusions includes: The light guide than the other two protrusions The other two projections are formed at locations closer to both end faces of the light guide in the longitudinal direction than the center across the center, and the at least three projections are formed at locations near the center in the longitudinal direction. The position of the protrusion is regulated by the support member, so that the light guide is held in parallel with the first surface or the second surface .

[5] The [2], wherein the other two projections of the at least three projections are respectively fitted into a round hole and a long hole provided in the second surface. Image reading device.

[6] The image reading device according to any one of claims 1 to 5, and an image forming unit that forms an image on a recording medium based on information of an image read by the reading unit of the image reading device And an image forming apparatus.
[7] The at least three protrusions protrude from the main body of the light guide body on the first surface side or the second surface side, respectively. The image forming apparatus described in 1.

According to the first to seventh aspects of the present invention, it is possible to reduce the bending of the light guide during image reading.

FIG. 1 is a diagram showing an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a schematic diagram showing the internal structure of the image reading apparatus according to the embodiment of the present invention. FIG. 3A is a diagram showing the shape of the light guide according to the embodiment of the present invention. FIG. 3B is a diagram showing the shape of the light guide according to the embodiment of the present invention. 3C is a cross-sectional view taken along the line CC of FIG. 3B showing the shape of the light guide according to the embodiment of the present invention. FIG. 4A is a perspective view showing the configuration of the first carriage and its peripheral part according to the embodiment of the present invention. FIG. 4B is an exploded perspective view of FIG. 4A showing the configuration of the first carriage and its peripheral part according to the embodiment of the present invention. FIG. 4C is an end view taken along the line DD in FIG. 4A showing the configuration of the first carriage and its peripheral portion according to the embodiment of the present invention. FIG. 5 is a diagram showing an attached state of the light guide according to the embodiment of the present invention. FIG. 6 is a diagram showing an attached state of the light guide according to the embodiment of the present invention. FIG. 7 is an explanatory diagram for explaining the operation of the embodiment of the present invention.

(Configuration of the entire image forming apparatus)
FIG. 1 shows an image forming apparatus according to an embodiment of the present invention. In the drawing, the appearance of the image reading apparatus 1 and the internal structure of the main body 100A disposed on the lower side of the image reading apparatus 1 are shown.

  The image forming apparatus 100 includes an image reading device 1 that reads an image from a document 9, an image forming unit 2 that prints an image on a sheet 30 as a recording medium, and a tray unit 3 that supplies the sheet to the image forming unit 2. It is prepared for. The image reading apparatus 1 is supported above the main body portion 100A by the support portion 4 so as to form a space in which printed sheets are discharged between the image forming portion 2 and the main body portion 100A that accommodates the tray portion 3. Has been.

  A touch panel 111 that presents an operation menu to the user and accepts various settings and the like, and a control panel 110 having a plurality of operation buttons 112 are provided on the upper portion of the front wall 121 corresponding to the front surface of the housing 12 of the image reading apparatus 1. Yes. A document cover 10 that can be opened and closed with respect to the housing 12 is disposed above the control panel 110. The document cover 10 is provided with an automatic sheet feeder 101 that conveys the document 9 placed on the sheet feed tray 101a to a reading position and discharges the document 9 after reading to a sheet discharge table 101b.

  The image forming unit 2 transfers the toner images of each color of yellow (Y), magenta (M), cyan (C), and black (K) to the intermediate transfer belt 20 and the intermediate transfer belt 20. Image forming units 25Y, 25M, 25C, and 25K, and an optical scanning device 250 that irradiates the first to fourth image forming units 25Y, 25M, 25C, and 25K with laser light modulated based on image information. Yes.

  The first image forming unit 25Y uses the photosensitive drum 251, the charger 252 that uniformly charges the surface of the photosensitive drum 251, and the electrostatic latent image formed on the surface of the photosensitive drum 251 by the optical scanning device 250 as a toner. And a primary transfer roller 254 for pressing the intermediate transfer belt 20 against the photosensitive drum 251. The second to fourth image forming units 25M, 25C, and 25K are configured in the same manner as the first image forming unit 25Y.

  The intermediate transfer belt 20 is driven by a driving roller 21 connected to a motor (not shown), and is formed by a first driven roller 22, a second driven roller 23, and a tension roller 24 that applies tension to the intermediate transfer belt 20. Rotate along the circulation path.

  Further, the image forming unit 2 faces the secondary transfer roller 26 disposed at a position facing the second driven roller 23 with the intermediate transfer belt 20 interposed therebetween, and the fixing roller 271 and the fixing roller 271 having a built-in heater. A fixing unit 27 having a pressurized pressure roller 272 and a discharge roller 28 for discharging the paper that has passed through the fixing unit 27 to a discharge table 29 are provided.

  The tray unit 3 has first to third trays 31 to 33 that store sheets 30 of different orientations, sizes, paper quality, and the like and are arranged in the vertical direction.

  In addition, the tray unit 3 corresponds to each of the first to third trays 31 to 33, and pick-up rollers 34A, 34B, and 34C for taking out the stored paper 30 and a plurality of papers 30 are taken out. In this case, separation rollers 35A, 35B, and 35C for separating them and registration rollers 36A, 36B, and 36C for conveying the paper 30 further downstream are provided. The registration rollers 36 </ b> A, 36 </ b> B, and 36 </ b> C operate in synchronization with the timing of image formation by the image forming unit 2, and the secondary transfer roller along the conveyance path 37 for the sheet 30 taken out from the first to third trays 31 to 33. 26 and the intermediate transfer belt 20.

  In this image forming apparatus 100, when sheets 30 having different sizes and orientations are stored in the respective trays 31 to 33, the sheet 30 supplied from each of the trays 31 to 33 has a conveyance path 37 at the center of the sheet 30. The sheet is conveyed so as to substantially coincide with the center of the sheet, and is discharged from the discharge roller 28 onto the discharge table 29.

(Configuration of image reading apparatus)
FIG. 2 is a schematic diagram showing the internal structure of the image reading apparatus 1. In this figure, the document cover 10 is not shown. The image reading apparatus 1 is disposed in the housing 12 along the main scanning direction and is movable in the sub-scanning direction, a lens 160 and a CCD (Charge Coupled Device). ) 161 and the like. The first carriage 14 is an example of a support member.

  The casing 12 has a box shape in which a part of the upper wall 122 facing the document cover 11 is opened. The casing 12 is opposed to the bottom wall 123 facing the top wall 122, and the sub-scanning direction (the horizontal direction in FIG. ) And the above-mentioned front wall 121 (see FIG. 1), and the front wall 121 and the rear wall 126 facing the main scanning direction (direction perpendicular to the paper surface of FIG. 2). Yes. An opening 122 a is formed in the upper wall 122 at a portion corresponding to the reading position of the document 9, and the opening 122 a is covered with a platen glass 120 that supports the document 9.

  A first rail 131 extending in the sub-scanning direction is fixed to the rear wall 126. A second rail 132 that extends in the sub-scanning direction is fixed to the bottom wall 123. Two each of the first rail 131 and the second rail 132 are arranged so as to be aligned in the main scanning direction, but only one of them is shown in FIG.

  The first carriage 14 includes a substrate 140 that extends in the main scanning direction along the first carriage 14, an LED 141 that is mounted on the substrate 140 and emits light for irradiating the document 9, and the substrate 140. The heat radiation member 145 that supports the surface opposite to the surface on which the LED 141 is mounted, and the light guide that extends in the main scanning direction along the first carriage 14 and is parallel to the substrate 140. 5, a reflector 143 that reflects part of the light emitted from the light guide 5 in the direction of the document 9, and a first mirror 146 that receives the reflected light of the document 9 are fixed. A plurality of LEDs 141 are mounted on the substrate 140, and the plurality of LEDs 141 constitute a light source as a whole.

  The first carriage 14 is guided by the first rail 131 and irradiates the image reading portion of the document 9 while moving in the sub-scanning direction together with each member such as the light guide 5, and the first mirror 146 The reflected light of the document 9 is reflected toward a second mirror 151 of the second carriage 15 described later.

  The light guide 5 is a rod-shaped polyhedron formed of a light-transmitting material such as polymethyl methacrylate resin, the incident surface 50a on which the light of the LED 141 is incident, and a part of the light incident from the incident surface 50a Has a first emission surface 50 b that emits the light toward the document 9, and a second emission surface 50 c that emits another part of the light incident from the incidence surface 50 a toward the reflector 143.

  The substrate 140 is mainly composed of epoxy resin, glass fiber, or the like, and a wiring pattern for supplying current to the LED 141 is formed on the surface thereof.

  Fixed to the second carriage 15 are a second mirror 151 that receives the reflected light from the first mirror 146 and a third mirror 152 that receives the reflected light from the second mirror 151. Yes.

  The second carriage 15 reflects the reflected light of the document 9 toward the lens 160 of the image reading unit 16 while being guided by the second rail 132 and moving in the sub-scanning direction.

The first carriage 14 and the second carriage 15 are driven by a driving mechanism (not shown), and the optical path length from the image reading portion of the document 9 to the CCD 161 (to be described later) while the first carriage 14 is moving in the sub-scanning direction. So that the movement amount of the second carriage 15 is half of the movement amount of the first carriage 14. The first carriage 14 and the second carriage 15 when the first carriage 14 moves to the vicinity of the end of the document 9 in the sub-scanning direction are indicated by a two-dot chain line in FIG.

  The image reading unit 16 includes a substrate 160 mounted with a lens 160 and a CCD (Charge Coupled Device) 161 fixed to a base plate 133 supported by the second rail 132.

  The image reading unit 16 is configured such that the reflected light from the third mirror 152 passes through the lens 160 and forms an image on the CCD 161, reads an image of the document 9 by the CCD 161, and outputs image data.

(Shape of light guide)
3 is a diagram showing the shape of the light guide 5 as a single unit. FIG. 3A shows the shape seen from the direction of arrow A in FIG. 2 parallel to the substrate 140, and FIG. 3B shows the shape orthogonal to the substrate 140. FIG. 3C shows a cross-sectional shape taken along the line CC of FIG. 3B. In these drawings, the curvature of the light guide 5 is exaggerated for the sake of explanation.

  As illustrated in FIG. 3A, the light guide 5 includes a main body 50, a pair of first protrusions 51 formed at both ends in the longitudinal direction of the main body 50, and a central portion in the longitudinal direction of the main body 50. And a second protrusion 52 formed integrally with each other.

  The main body 50 has an entrance surface 50a and first and second exit surfaces 50b, 50c, and a first portion that projects from the longitudinal direction (left-right direction in FIG. 3A) toward the entrance surface 50a. Is curved in the direction of When the length in the longitudinal direction of the main body 50 is D1 and the amount of displacement of the central portion with respect to the straight line connecting both ends in the longitudinal direction of the main body 50 is D2, the ratio (curvature) of D2 to D1 is 0.1. It is desirably 0.5%, and more desirably 0.2 to 0.4%. In the present embodiment, this ratio is set to 0.3%.

  The dimension of D2 is desirably 0.3 to 1.5 mm, and more desirably 0.6 to 1.2 mm. In the present embodiment, the dimension of D2 is set to 1.0 mm.

  The first protrusion 51 protrudes in a direction perpendicular to the incident surface 50a rather than the incident surface 50a, and a tip surface 51a is formed at the tip of the protruding portion.

  The second protrusion 52 protrudes by the same distance as the protrusion distance from the incident surface 50a of the first protrusion 51 in the direction perpendicular to the incident surface 50a rather than the incident surface 50a, and the tip of the protruding portion is the tip. A surface 52a is formed.

  As shown in FIG. 3B, the light guide 5 has a central portion that protrudes in the longitudinal direction (left-right direction in FIG. 3B) in the second direction that intersects the first direction perpendicularly. Is so curved.

  The first and second protrusions 51 and 52 are formed so as to protrude from the main body 50 in the thickness direction of the light guide 5 (vertical direction in FIG. 3B), and the tips of the protrusions of the first protrusion 51 A tip end surface 51b is formed on the surface. The distal end surface 51b is formed with a boss portion 51c having a cylindrical base end portion on the distal end surface 51 side and a gradually decreasing distal end diameter. Further, a flat tip surface 52 b is formed at the tip of the protruding portion of the second protrusion 52. When viewed from the direction shown in FIG. 3B, the protruding amount of the tip surface 51b of the first protrusion 51 and the protruding amount of the tip surface 52b of the second protrusion 52 with respect to the main body 50 are the same.

  As shown in FIG. 3C, the main body 50 of the light guide 5 includes a first reflecting surface 50d that reflects a part of light incident from the incident surface 50a toward the first emitting surface 50b, and a first reflecting surface 50d. A first side surface 50e formed between the reflective surface 50d and the second output surface 50c, a second side surface 50f formed between the first reflective surface 50d and the incident surface 50a, A second reflecting surface 50g that reflects part of the light incident from the surface 50a toward the second emitting surface 50c, and a second reflecting surface 50g formed between the second reflecting surface 50g and the first emitting surface 50b. 3 side surfaces 50h.

  The incident surface 50a and the tip surface 52a of the second protrusion 52 are formed in parallel, and the tip surface 52b of the second protrusion 52 is formed to be perpendicular to the tip surface 52a.

  The first protrusion 51 is formed with the same shape and the same size as the second protrusion 52 in a cross section orthogonal to the central axis of the light guide 5, but in FIG. Only the portion that appears to be displaced from the second protrusion 52 is shown.

  In the state where no external force is applied, each surface 50a to 50h of the main body 50 is curved with respect to the longitudinal direction, but the light guide 5 can be bent by the external force until it is at least parallel to the longitudinal direction. It has flexibility and has elasticity to return to its original curved shape when external force is lost.

  Such a curved shape of the light guide 5 can be formed, for example, by changing the temperature of the mold at the time of injection molding depending on the part.

(Configuration of first carriage and member fixed to first carriage)
FIG. 4 is a view showing the first carriage 14 and the light guide 5 fixed to the first carriage 14, the substrate 140, the reflector 143, the first mirror 146, and the like. FIG. 4A shows these members. FIG. 4B is an exploded perspective view, and FIG. 4C is an end view taken along the line D-D in FIG. 4A.

  The first carriage 14 is molded from a metal plate such as a galvanized steel plate and is formed to extend in the main scanning direction. Both end portions of the first carriage 14 are slidably supported by the first rail 131.

  As shown in FIG. 4B, a support surface 14a for supporting the light guide 5 is formed on the first carriage 14 along the longitudinal direction. The first support surface is a flat surface formed so as to be parallel to the main scanning direction and the sub-scanning direction orthogonal to the main scanning direction.

  The first carriage 14 is provided with a reflector mounting base 142 in parallel with the support surface 14 a, and the reflector 143 is attached to the reflector mounting base 142. A mirror mounting plate 14d is provided below the reflector mounting base 142, and a first mirror 146 is mounted on the mirror mounting plate 14d.

  Further, the first carriage 14 is formed with a substrate mounting surface 14b which is continuous with the support surface 14a and is bent at right angles to the support surface 14a in the sub-scanning direction (see FIG. 4C). The board attachment surface 14b is provided with screw holes 14c for screwing the board 140 at a plurality of places (five places in the present embodiment).

  As shown in FIG. 4B, a plurality of LEDs 141 (46 in this embodiment) are mounted on the surface 140a of the substrate 140 in a line along the main scanning direction. The substrate 140 has five through holes 140d corresponding to the five screw holes 14c of the first carriage 14, respectively. The board 140 is formed with a long hole 140e for temporarily fastening the board 140 when assembled to the first carriage 14.

  As shown in FIG. 4C, a sheet-like heat transfer member 140c having insulating properties and thermal conductivity is attached to the back surface 140b of the substrate 140 corresponding to the region where the LEDs 141 are fixed. The board 140 is fixed to the first carriage 14 by being screwed into the five screw holes 14c of the board mounting surface 14b with bolts 17. The heat transfer member 140c is made of, for example, silicon.

  As shown in FIGS. 4B and 4C, a heat dissipation member 145 is disposed to face the back surface 140 b of the substrate 140. The heat dissipating member 145 includes a plate-like heat transfer portion 145a that contacts the back surface 140b of the substrate 140, and a heat dissipating portion 145b that is formed by bending the heat transfer portion 145a at a right angle toward the substrate 140. Yes. The heat dissipation member 145 is made of a metal plate such as a galvanized steel plate and has a thickness of 0.5 mm, for example.

  The heat transfer portion 145a of the heat radiating member 145 contacts the back surface 140b of the substrate 140 and the heat transfer member 140c, and is screwed together with the substrate 140 into the three screw holes 14c of the substrate mounting surface 14b by the bolts 17, and the first It is fixed to the carriage 14.

  As shown in FIG. 4C, since the heat transfer member 140c is not attached to the portion to which the substrate 140 is screwed, the substrate 140 and the heat dissipation member 145 are elastically deformed according to the thickness of the heat transfer member 140c, The heat transfer portion 145a of the heat dissipation member 145 facing the heat transfer member 140c is pressed against the heat transfer member 140c.

  The heat radiating portion 145b of the heat radiating member 145 is positioned above the light guide 5 in the vertical direction, and covers the upper portion of the light emitting surface 141a of the LED 141 so that light emitted from the LED 141 does not directly enter the user's eyes. .

(Retaining light guide)
As shown in FIGS. 4A and 4B, the light guide 5 includes a first protrusion 51 supported by a holding member 144 fixed to the first carriage 14, and a second protrusion 52 having a first protrusion 51. The support surface 14a of the carriage 14 and the surface 140a of the substrate 140 are supported.

  FIG. 5 is a view of the light guide 5 attached to the first carriage 14 as viewed from the upper side in the direction perpendicular to the support surface 14a. FIG. 5A is a view showing the light guide 5 and its peripheral portion. (B) And (c) is the elements on larger scale. 5A shows a state in which the heat radiating portion 145b of the heat radiating member 145 is removed.

  As shown in FIG. 5A, 46 LEDs 141 are mounted on the substrate 140 at equal intervals, and two LEDs 141 located in the center (the 23rd counted from one end side of the substrate 140) The tip surface 52a of the second protrusion 52 of the light guide 5 is configured to contact the surface 140a of the substrate 140 at a position between the 24th LEDs 141).

  The first protrusion 51 of the light guide 5 is supported by the holding member 144 so that the first contact surface 51 a is pressed toward the surface 140 a of the substrate 140.

  The holding member 144 includes a flat portion 144a that contacts the first carriage 14, a first arm 144b that presses the first protrusion 51 of the light guide 5 against the support surface 14a of the first carriage 14, and a light guide. And a second arm 144c that integrally presses the first projection 51 of the five against the surface 140a of the substrate 140.

  The second arm 144 c is in contact with the back surface 51 d, the tip of which is opposite to the tip surface 51 a of the first protrusion 51. The first and second arms 144b and 144c have elasticity, and press the first protrusion 51 in an elastically deformed state.

  Further, in the flat portion 144a of the holding member 144, there are two positioning holes 144d that are fitted into two protrusions 14e formed on the first carriage 14 to position the holding member 144, and the first carriage. 14 is formed at a position corresponding to the screw hole 14 f formed in the through hole 144 e through which the bolt 17 for fixing the holding member 144 to the first carriage 14 is passed, and the opening 14 g of the first carriage 14. Correspondingly provided long holes 144 are formed.

  In the light guide 5, the second protrusion 52 comes into contact with the surface 140 a of the substrate 140, and the first protrusions 51 at both ends in the longitudinal direction are pressed toward the surface 140 a of the substrate 140 by the holding members 144. Therefore, the curved surface is supported in a state of being elastically deformed from a curved shape so that the incident surface 50a is parallel to the surface 140a of the substrate 140. The tip end surface 52a of the second protrusion 52 is pressed against the surface 140a of the substrate 140 by the elasticity of the light guide 5 itself.

  The protrusion amount of the first and second protrusions 51 and 52 from the main body 50 is larger than the distance from the substrate 140 of the light emitting surface 141a of the LED 141, and the main body 50 of the light guide 5 is separated from the incident surface 50a. The LED 141 is positioned at a position where a gap is formed between the LED 141 and the light emitting surface 141a.

  FIG. 5B shows an enlarged view of the periphery of the left first protrusion 51 in FIG. A boss 51 c formed on the first protrusion 51 is fitted in a through hole 14 h formed on the first carriage 14. The diameter of the through hole 14h is formed larger than the diameter of the columnar portion of the boss portion 51c so as to absorb the expansion and contraction in the longitudinal direction due to the temperature change of the light guide 5.

  FIG. 5C shows an enlarged view of the peripheral portion of the first protrusion 51 on the right side in FIG. A boss 51 c formed on the first protrusion 51 is fitted in a long hole 14 i formed on the first carriage 14. The long hole 14i is formed so as to extend in a direction orthogonal to the longitudinal direction of the light guide 5. The length in the width direction of the long hole 14i along the longitudinal direction of the light guide 5 is the length of the through hole 14h. The dimension is smaller than the diameter and slightly longer than the diameter of the cylindrical portion of the boss 51c. The length of the long hole 14i in the length direction is set to a dimension that allows deformation of the light guide 5 from a curved shape to a linear shape.

  FIG. 6 is a view of the light guide 5 attached to the first carriage 14 and its peripheral portion as seen from a direction perpendicular to the substrate attachment surface 14b.

  The first arm 144 b of the holding member 144 comes into contact with the back surface 51 e on the opposite side of the tip surface 51 b of the first protrusion 51 of the light guide 5, and the first protrusion 51 is a support surface of the first carriage 14. It is pressed toward 14a. Further, the front end surface 52b of the second protrusion 52 is pressed against the support surface 14a by the elasticity of the light guide 5 itself.

  As described above, the light guide 5 is elastically deformed from a curved shape before assembly to a linear shape so that a gap is formed between the main body 50 and the support surface 14a of the first carriage 14. And supported by the holding member 144 and the support surface 14a.

(Assembly procedure)
Next, a procedure for assembling the first carriage 14, the light guide 5, the substrate 140, and the heat dissipation member 145 will be described.

  The worker who performs the assembly work has a boss 51c formed in one first protrusion 51 of the light guide 5 in the long hole 14i of the first carriage 14 in the through hole 14h of the first carriage 14. The light guide 5 is arranged on the support surface 14a so that the bosses 51c formed on the other first protrusion 51 of the light guide 5 are fitted together.

  Next, the operator fixes the two holding members 144 to the first carriage 14 so as to support the pair of first protrusions 51. In the process of fixing the holding member 144, the curved shape of the light guide 5 shown in FIG. 3B is deformed into a linear shape. Further, at this stage, the first protrusion 51 and the second protrusion 52 partially protrude from the support surface 14a of the first carriage 14 toward the side on which the substrate 140 is attached.

  Next, the operator attaches the long holes 140e of the board 140 to the two protrusions 14j formed on the board mounting surface 14b and supports the board 140 in the five screw holes formed on the board mounting surface 14b. The board | substrate 140 is screwed in two places of these, and the board | substrate 140 is fixed. In the process of fixing the substrate 140, the light guide 5 is pushed by the substrate 140, the curvature of the light guide 5 is reduced, and the light guide 5 is deformed into a linear shape.

  Next, the operator fastens the substrate 140 and the heat radiating member 145 together with the bolts 17 at the remaining three of the five screw holes formed on the substrate mounting surface 14b, and the heat radiating member 145 is attached to the first carriage. 14 is fixed. As described above, the first carriage 14, the light guide 5, the substrate 140, and the heat dissipation member 145 are assembled.

(Operation of this embodiment)
Next, the operation of the present embodiment will be described separately for (1) operation of the image forming apparatus and (2) suppression of deformation of the light guide.

(1) Operation of Image Forming Apparatus 100 When a user places document 9 on paper feed tray 101a or platen glass 120 and operates touch panel 111 and operation button 112 of control panel 110 to instruct the copying of the document. The image reading apparatus 1 starts reading an image. When a document 9 is placed on the sheet feed tray 101a, a control unit (not shown) of the image reading apparatus 1 controls the automatic sheet feed unit 101 to read the document 9 on the platen glass 120. Transport to.

  The control unit of the image reading apparatus 1 supplies current to the plurality of LEDs 141 to emit light, and controls the drive mechanism to drive the first and second carriages 14 and 15 in the sub-scanning direction. The light incident on the incident surface 50a of the light guide 5 is emitted from the first emission surface 50b of the light guide 5 or emitted from the second emission surface 50c and reflected by the reflector 143, and the document 9 is reflected. Irradiate. The reflected light reflected from the surface of the document 9 is reflected by the first mirror 146, the second mirror 151, and the third mirror 152, and enters the lens 160 of the image reading unit 16.

  The light transmitted through the lens 160 forms an image on the CCD 161, and the image of the document 9 is read by the CCD 161. The control unit of the image reading apparatus 1 sends image data as an image reading result to the optical scanning device 250 of the image forming unit 2. Thereafter, when the control unit reads the document 9 placed on the sheet feed tray 101a, the control unit controls the automatic sheet feed unit 101 to discharge the document 9 to the discharge table 101b.

  The optical scanning device 250 irradiates the photosensitive drum 251 charged by the charger 252 with a light beam modulated based on the image data of each color of YMCK, and forms an electrostatic latent image on the surface of the photosensitive drum 251. The electrostatic latent image is developed with toner by the developing unit 253 to form a toner image. The toner image on the photosensitive drum 251 is transferred to the intermediate transfer belt 20 by the primary transfer roller 254.

  On the other hand, after any one of the first to third trays 31 to 33, for example, the first tray 31, the sheet 30 is taken into the sheet conveyance path 37 by the pickup roller 34A and is rolled by the separation roller 35A. The toner image on the intermediate transfer belt 20 is transferred onto the paper 30 by being conveyed between the secondary transfer roller 26 and the intermediate transfer belt 20 by the registration roller 36A.

  Thereafter, the toner image on the paper 30 is fixed by the fixing unit 27 and then discharged to the discharge table 29 by the discharge roller 28.

(2) Suppression of Deformation of Light Guide Body As shown in FIG. 7, when the incident surface 50 a of the light guide body 5 is heated by heat generated from the LED 141 when the image forming apparatus 1 is used, the heated portion expands. Then, a force is generated to warp the light guide 5 such that both ends of the light guide 5 are separated from the surface 140 a of the substrate 140 and the center portion protrudes toward the substrate 140. However, the back surface 140b of the substrate 140 is supported by the heat radiating member 145, and deformation of the substrate 140 together with the light guide 5 is suppressed.

[Other embodiments]
The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention.

  The shape of the light guide 5 is not limited to that shown in the above embodiment, and may be a rectangular parallelepiped, for example. In the above-described embodiment, one second protrusion 52 is provided at the center of the light guide 5 in the longitudinal direction. However, the present invention is not limited to this, and the first protrusion 51 formed at both ends. A plurality of second protrusions 52 may be provided between the two. Further, the material of the light guide 5 is not particularly limited.

  The place where the light guide 5 is held by the holding member 144 is not limited to the vicinity of the end face in the longitudinal direction of the light guide 5 as in the above embodiment, but the support surface 14a of the first carriage 14 or the surface of the substrate 140. What is necessary is just to be a plurality of places closer to both end faces in the longitudinal direction than the center part in contact with 140a.

  In the above embodiment, the second support surface 52a of the second protrusion 52 is configured to come into contact with the surface 140a of the substrate 140 at a portion between the two LEDs 141. For example, the second support surface 52a of the second protrusion 52 may contact the surface 140a of the substrate 140 at a position shifted in the width direction of the substrate 140 with respect to the arrangement direction of the LEDs 141.

  In the above embodiment, the heat transfer member 145a and the heat dissipating part 145b are formed by bending the heat dissipating member 145 with a plate-like member. However, the heat dissipating part 145b is not limited to this. You may form by attaching a radiation fin to the continuous plane. Moreover, the thermal radiation part 145b is not restricted to what covers the upper side of the light emission surface 141a of LED141 in the perpendicular direction.

DESCRIPTION OF SYMBOLS 1 ... Image reading device, 2 ... Image formation part, 3 ... Tray part, 4 ... Support part, 5, 5A, 5B, 5C, 7 ... Light guide, 5a ... Incident surface, 5b, 5d ... Side surface, 5c ... Outgoing Surface, 5e ... first end surface, 5f ... second end surface, 7a ... incident surface, 7b ... first reflective surface, 7c ... outgoing surface, 7d ... first exit surface, 7e ... second exit surface, 7f ... second reflective surface, 7g ... side surface, 9 ... document, 11 ... document cover, 12 ... housing, 14 ... first carriage, 14a ... first support surface, 14b ... substrate mounting surface, 14c ... screw Hole, 14d ... Mirror mounting plate, 14e ... Projection part, 14f ... Screw hole, 4g ... Opening part, 14h ... Through-hole, 14i ... Long hole, 14j ... Projection part, 15 ... Second carriage, 16 ... Image reading part , 17 ... bolts, 20 ... intermediate transfer belt, 21 ... drive roller, 22, 23 ... driven roller, 24 ... tension Roller, 25Y ... first image forming unit, 25M ... second image forming unit, 25C ... third image forming unit, 25K ... fourth image forming unit, 26 ... secondary transfer roller, 27 ... fixing unit, 28 ... discharge roller, 29 ... discharge table, 30 ... paper, 31 ... first tray, 32 ... second tray, 33 ... third tray, 34A, 34B, 34C ... pickup roller, 35A, 35B, 35C ... Separation roller, 36A, 36B, 36C ... registration roller, 37 ... conveying path, 50 ... main body, 50a ... incident surface, 50b ... first exit surface, 50c ... second exit surface, 50d ... first reflection surface, 50e ... first side surface, 50f ... second side surface, 50g ... second reflection surface, 50h ... third side surface, 51 ... first projection, 51a ... first tip surface, 51b ... third Tip surface, 51c ... , 52 ... second protrusion, 52 a ... second tip surface, 52 b ... fourth tip surface, 100 ... image forming apparatus, 100 A ... body part, 110 ... control panel, 111 ... touch panel, 112 ... operation buttons , 120 ... platen glass, 121 ... front wall, 122 ... upper wall, 122a ... opening, 123 ... bottom wall, 124 ... side wall, 125 ... side wall, 126 ... rear wall, 131 ... first rail, 132 ... second Rail, 133 ... base plate, 140 ... substrate, 140a ... front surface, 140b ... back surface, 140c ... heat transfer member, 140d ... through hole, 140e ... long hole, 141 ... LED, 141a ... light emitting surface, 142 ... reflector mounting base , 143 ... reflector, 144 ... holding member, 144a ... plane part, 144b ... first arm, 144c ... second arm, 144d ... positioning hole, 144e ... penetrating Through hole, 145 ... heat radiating member, 145a ... heat transfer part, 145b ... heat radiating part, 146 ... first mirror, 151 ... second mirror, 152 ... third mirror, 160 ... lens, 162 ... substrate, 250 ... Optical scanning device, 251 ... photosensitive drum, 252 ... charger, 253 ... developer, 254 ... primary transfer roller, 271 ... fixing roller, 272 ... pressure roller

Claims (7)

A plurality of light emitting elements that emit light for irradiating a document;
A substrate on which the plurality of light emitting elements are mounted, the substrate on which the plurality of light emitting elements are mounted along the longitudinal direction of the substrate;
A surface of the substrate on which the plurality of light emitting elements are mounted, and a first surface that contacts the portion on which the plurality of light emitting elements are not mounted and fixes the substrate, and the first surface And a support member having a second surface arranged at a predetermined angle;
A light guide that receives light from the plurality of light emitting elements and guides the light in the direction of the document, and is formed with at least three protrusions;
A pressing member that presses the light guide against the second surface;
A reading unit that reads the image of the document by reflected light reflected from the document by the light emitted from the light guide,
At least one of the at least three protrusions is formed at a location closer to the longitudinal center of the light guide than the other two protrusions;
The other two protrusions are formed at locations closer to both end faces of the light guide in the longitudinal direction than the center across the center,
The positions of the at least three protrusions are regulated with respect to the substrate and the support member, so that the light guide is held parallel to the first surface or the second surface. A characteristic image reading apparatus. A plurality of light emitting elements that emit light for irradiating a document;
A substrate on which the plurality of light emitting elements are mounted, wherein the plurality of light emitting elements are mounted along a longitudinal direction of the substrate;
A light guide that receives light from the plurality of light emitting elements and guides the light in the direction of the document, and is formed with at least three protrusions;
A surface of the substrate on which the plurality of light-emitting elements are mounted, a first surface that contacts a portion on which the plurality of light-emitting elements are not mounted and fixes the substrate, and the plurality as viewed from the substrate. A support member having a second surface for supporting the light guide on the light emitting element side;
A pressing member that presses the light guide against the support member; and a reading unit that reads an image of the document by reflected light reflected from the document by light emitted from the light guide;
The pressing member presses the light guide toward the second surface from a direction different from a direction orthogonal to the first surface, and one of the at least three protrusions is the other two. Formed at a location closer to the center of the light guide in the longitudinal direction than one projection, and at least one of the other two projections is fitted into a long hole formed in the second surface, The position of one protrusion is regulated at a position closer to the center than the other two protrusions , so that the light guide is held parallel to the first surface or the second surface. image reading apparatus characterized by.   The image reading apparatus according to claim 1, wherein the light guide is pressed from a direction parallel to the protruding direction. A plurality of light emitting elements that emit light for irradiating a document;
A substrate on which the plurality of light emitting elements are mounted, wherein the plurality of light emitting elements are mounted along a longitudinal direction of the substrate;
A light guide that receives light from the plurality of light emitting elements and guides the light in the direction of the document, and is formed with at least three protrusions;
A surface of the substrate on which the plurality of light-emitting elements are mounted, a first surface that contacts a portion on which the plurality of light-emitting elements are not mounted and fixes the substrate, and the plurality as viewed from the substrate. A support member having a second surface for supporting the light guide on the light emitting element side;
A reading unit that reads the image of the document by reflected light reflected from the document by the light emitted from the light guide,
At least one of the at least three protrusions is formed at a location closer to the center in the longitudinal direction of the light guide than the other two protrusions,
The other two protrusions are formed at positions closer to both end faces of the light guide in the longitudinal direction than the center across the center, and the positions of the at least three protrusions are regulated by the support member. Thus , the light guide is held in parallel to the first surface or the second surface .   5. The image reading apparatus according to claim 4, wherein the other two projections of the at least three projections are respectively fitted into a round hole and a long hole provided in the second surface. An image reading apparatus according to any one of claims 1 to 5,
An image forming apparatus comprising: an image forming unit that forms an image on a recording medium based on information of an image read by the reading unit of the image reading device. The said at least 3 protrusion protrudes from the main body of the said light guide to the said 1st surface side or the said 2nd surface side, The any one of Claim 1 to 6 characterized by the above-mentioned. Image forming apparatus.

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