JP6205458B2 - Image reading apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to an image reading apparatus that reads a document or the like, and an image forming apparatus including the image reading apparatus.

  In this type of image reading apparatus, an original is illuminated by an illuminating device under the glass while the original is conveyed on the glass in the sub-scanning direction, and the original is mainly captured by an imaging device such as a CCD (Charge Coupled Device). The document is scanned and scanned repeatedly in the scanning direction, or the original is positioned and placed on the glass, and the original is illuminated by the illuminator while moving the illumination device and the image sensor in the sub-scanning direction below the glass. Thus, the document is repeatedly scanned in the main scanning direction by the image sensor and read. There are various illumination devices for illuminating a document, and fluorescent lamps, LED arrays, and the like are used.

  Further, in Patent Documents 1 to 3, LEDs are arranged at both ends of a rod-shaped light guide member, and light emitted from each LED is incident on both ends of the light guide member to guide the light. The light is emitted from the light emitting surface along the longitudinal direction of the light guide member, and the original is illuminated by the emitted light.

JP 2010-119054 A JP 2012-160866 A JP 2012-212069 A

  By the way, when providing LED near the edge part of a light guide member like patent document 1 thru | or 3, since a light guide member is made of synthetic resins, such as an acrylic resin, a light guide member is heated by heat_generation | fever of LED. There is a possibility of deformation. In recent years, the document reading speed of the image reading apparatus has been increased, and the amount of light for illuminating the document has been increased accordingly. Therefore, the amount of heat generated by the LED tends to increase, and the life of the LED tends to decrease. is there. For this reason, the board | substrate with which LED is mounted employ | adopts the thing with high heat dissipation efficiency, or has provided the heat sink on the board | substrate.

  However, in Patent Document 1, a light guide member, an LED substrate, a heat sink, and the like are mounted on a frame, and a part of the frame is positioned below the light guide member and the LED substrate. There was a problem that the convection of surrounding air such as the end portion of the member, the LED substrate, and the heat sink deteriorates and the heat dissipation efficiency of the LED substrate and the heat sink decreases.

  Further, in Patent Documents 2 and 3, the heat sink is exposed to the outside of the frame or the casing, and the heat dissipation efficiency of the heat sink is improved. Therefore, the heat dissipation efficiency from the light guide member or the LED was low.

  Accordingly, the present invention has been made in view of the above-described conventional problems, and provides an image reading apparatus and an image forming apparatus that can maintain high heat dissipation efficiency of a light guide member while having a simple configuration. For the purpose.

In order to solve the above-described problems, an image reading apparatus according to the present invention includes a light guide member, a light emitting element disposed on an end side of the light guide member, a reading unit that reads an irradiated object, and the light guide member. An image reading apparatus provided with a housing that supports the substrate, the substrate on which the light emitting element is mounted, a heat dissipation member in contact with the substrate being provided, and a gap is provided between the heat dissipation member and the housing. The light guide member is a long light guide member, and the heat radiating member has a main surface opposite to a surface of the substrate opposite to the mounting surface of the light emitting element, and the main surface. A side surface intersecting the housing side, and in the longitudinal direction of the light guide member, a gap is provided between the housing side end of the side surface of the heat dissipation member and the housing. Yes. In addition, the image reading apparatus of the present invention includes a light guide member, a light emitting element disposed on an end side of the light guide member, a reading unit that reads an irradiated object, and a housing that supports the light guide member. An image reading apparatus comprising: a substrate on which the light emitting element is mounted; a heat radiating member in contact with the substrate; a gap is provided between the heat radiating member and the housing; An end portion of the optical member is protruded from the side end of the casing to the outside of the casing. In addition, the image reading apparatus of the present invention includes a light guide member, a light emitting element disposed on an end side of the light guide member, a reading unit that reads an irradiated object, and a housing that supports the light guide member. An image reading apparatus comprising: a substrate on which the light emitting element is mounted; and a heat dissipation member in contact with the substrate, wherein a gap is provided between the heat dissipation member and the housing, A holding member that holds the light guide member and the light emitting element is provided at an opening of the housing facing the illuminator, and an end portion of the holding member together with the light guide member from a side end of the housing It protrudes to the outside of the housing .

In the image reading apparatus of the present invention, the light guide member is a long light guide member, and the heat radiating member is a main surface facing a surface of the substrate opposite to the mounting surface of the light emitting element. A side surface that intersects the main surface toward the housing side, and in the longitudinal direction of the light guide member, between the end portion of the side surface of the heat dissipation member on the housing side and the housing A gap is provided in

In the image reading apparatus of the present invention is an end of the front Kishirubeko member projecting outwardly of the housing from the side end of the housing.

  In such an image reading apparatus of the present invention, the end portion of the light guide member protrudes from the side end of the casing to the outside of the casing. Accordingly, the end portion of the light guide member is disposed outside the housing, and the light emitting element disposed on the end portion side of the light guide member is also disposed outside the housing. For this reason, heat hardly accumulates in the vicinity of the end portion of the light guide member and the light emitting element, and heat dissipation efficiency from the end portion of the light guide member and the light emitting element is improved.

In the image reading apparatus of the present invention, the image reading apparatus includes a holding member that holds the light guide member and the light emitting element, and is provided at an opening of the casing facing the irradiated body. Are projected from the side end of the casing together with the end of the light guide member to the outside of the casing .

  When the end portion of such a holding member is arranged outside the casing, the end portion of the light guide member and the light emitting element are arranged outside the casing.

In the image reading apparatus of the present invention, the end portion of the holding member has a front Kimoto plate, and a front Kiho heat member is provided.

  Thus, by disposing the heat dissipation member on the outside of the housing, the heat dissipation efficiency of the heat dissipation member is high, and the temperature rise of the end portion of the light guide member and the light emitting element can be suppressed by the heat dissipation member.

In the image reading apparatus of the present invention, the light guide member is a long light guide member, and the holding member is provided along a longitudinal direction of the light guide member and is reflected by the irradiated body. It has been reflected light has a slit bets passing into the interior of the housing, and the front Symbol slits extended to the outside of the housing.

  When such a slit of the holding member is extended to the outside of the housing, air convects through the slit, so that the heat radiation efficiency of the end portion of the light guide member, the light emitting element, the substrate, the heat radiation member, and the like is further improved.

  Furthermore, in the image reading apparatus of the present invention, the heat dissipation perpendicular to the outward direction opposite to the light guide member with respect to the heat dissipation member, the vertical direction of the heat dissipation member, the outward direction, and the vertical direction. Spaces are provided on both lateral sides of the member.

  In this case, the heat dissipation efficiency of the heat radiating member can be increased, and the temperature rise of the end portion of the light guide member and the light emitting element can be further suppressed.

  On the other hand, an image forming apparatus of the present invention includes the image reading apparatus of the present invention and a printing unit that prints an image of the irradiated object read by the image reading apparatus on a recording sheet.

  Even in such an image forming apparatus, the same effects as the image reading apparatus of the present invention can be obtained.

In the present invention, the heat dissipation efficiency of the light guide member can be kept high while having a simple configuration.
It becomes .

1 is a cross-sectional view illustrating an image forming apparatus including a first embodiment of an image reading apparatus of the present invention. FIG. 2 is a cross-sectional view illustrating the image reading device and the document conveying device of FIG. 1. It is a perspective view which extracts each light guide member and each LED of the illuminating device in the scanning unit of the image reading apparatus of FIG. It is a perspective view which extracts and shows each light guide member and each LED of the illuminating device of FIG. 3 from the downward direction. It is a perspective view which expands and shows the light guide member in an illuminating device. It is sectional drawing which expands and shows a scanning unit. It is a perspective view which shows a scanning unit. It is a perspective view which expands and shows the edge part of a scanning unit. In a scanning unit, it is a perspective view which expands and shows the state which removed the heat sink and exposed the LED board. In a scanning unit, it is a perspective view which expands and shows the state which removed the LED board and the heat sink and exposed the edge part of the lid-shaped holding member. It is a perspective view which shows the state which attached the LED board and the heat sink to the edge part of a lid-shaped holding member seeing from the downward direction. FIG. 11B is a perspective view showing the state of FIG. 11A viewed from below at another angle. (A), (b) is the top view and side view which show the light guide member in the illuminating device of the image reader of 2nd Embodiment. (A), (b) is the top view and side view which show the light guide member in the illuminating device of the image reader of 3rd Embodiment. It is sectional drawing which expands and shows the image reading apparatus of 4th Embodiment. It is sectional drawing which expands and shows the image reading apparatus of 5th Embodiment. It is sectional drawing which shows the image reading apparatus and document conveying apparatus of 6th Embodiment. FIG. 17 is a side view schematically showing a first scanning unit and an illumination device in the image reading device of FIG. 16. It is a perspective view which shows typically a 1st scanning unit and an illuminating device seeing from diagonally upward direction.

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

  FIG. 1 is a sectional view showing an image forming apparatus provided with a first embodiment of an image reading apparatus of the present invention. The image forming apparatus 1 has a copying function of reading a document and printing it on a recording sheet, and includes an image reading device 2, a document conveying device 3, a printing unit 4, a paper feed cassette 5, and the like.

  The image data handled in the image forming apparatus 1 corresponds to a color image using each color of black (K), cyan (C), magenta (M), yellow (Y), or a single color (for example, black). This corresponds to the monochrome image used. For this reason, the printing unit 4 is provided with four developing devices 12, photosensitive drums 13, drum cleaning devices 14, and chargers 15 in order to form four types of toner images corresponding to the respective colors. Four image stations Pa, Pb, Pc, and Pd are configured in association with black, cyan, magenta, and yellow.

  In each of the image stations Pa, Pb, Pc, and Pd, after the residual toner on the surface of the photosensitive drum 13 is removed and collected by the drum cleaning device 14, the surface of the photosensitive drum 13 is set to a predetermined potential by the charger 15. It is charged uniformly, the surface of the photosensitive drum 13 is exposed by the optical scanning device 11, an electrostatic latent image is formed on the surface, and the electrostatic latent image on the surface of the photosensitive drum 13 is developed by the developing device 12, A toner image is formed on the surface of the photosensitive drum 13. As a result, a toner image of each color is formed on the surface of each photosensitive drum 13.

  Subsequently, while the intermediate transfer belt 21 is moved in the direction of the arrow C, the residual toner on the intermediate transfer belt 21 is removed and collected by the belt cleaning device 25, and then each color toner image is transferred onto the surface of each photosensitive drum 13. The toner images are sequentially transferred onto the belt 21 and overlapped to form a color toner image on the intermediate transfer belt 21.

  A nip area is formed between the intermediate transfer belt 21 and the transfer roller 26a of the secondary transfer device 26, and the recording sheet conveyed through the sheet conveyance path R1 is sandwiched and conveyed in the nip area. The color toner image on the surface of the intermediate transfer belt 21 is transferred onto a recording sheet. Then, the recording paper is sandwiched between the heating roller 31 and the pressure roller 32 of the fixing device 17 and heated and pressed to fix the color toner image on the recording paper.

  On the other hand, the recording sheet is pulled out from the sheet feeding cassette 5 by the pickup roller 33 and is conveyed through the sheet conveying path R 1, via the secondary transfer device 26 and the fixing device 17, and then the sheet discharge tray via the sheet discharge roller 36. To 39. In this paper conveyance path R1, after the recording paper is temporarily stopped and the leading edges of the recording paper are aligned, recording is performed in accordance with the transfer timing of the color toner image in the nip area between the intermediate transfer belt 21 and the transfer roller 26a. A registration roller 34 for starting the conveyance of the paper, each conveyance roller 35 for urging the conveyance of the recording paper, a paper discharge roller 36, and the like are arranged.

  When printing not only on the front side of the recording paper but also on the back side, the recording paper is conveyed in the reverse direction from the paper discharge roller 36 to the reverse path Rr, so that the front and back sides of the recording paper are reversed and the recording paper is registered. The image is guided again to the roller 34, and the image is recorded and fixed on the back surface of the recording paper, similarly to the front surface of the recording paper, and the recording paper is carried out to the paper discharge tray 39.

  Next, the image reading device 2 of the first embodiment will be described. FIG. 2 is a cross-sectional view showing the image reading device 2 and the document conveying device 3.

  In FIG. 2, the document conveying device 3 is pivotally supported on one side of the lower image reading device 2 by a hinge (not shown) and opened and closed by moving the front side up and down. When the document conveying device 3 is opened, the document placing glass 41 of the image reading device 2 is opened.

  The image reading apparatus 2 includes a document placing glass 41, a document reading glass 42, a scanning unit 43, a moving unit 44, and the like. The moving unit 44 includes a guide shaft 48 that guides the scanning unit 43 in the sub-scanning direction Y, and a drive unit (not shown) that moves and positions the scanning unit 43 in the sub-scanning direction Y.

  The scanning unit 43 includes an illumination device 45, an imaging lens 46, a CCD (Charge Coupled Device) 47, first to fourth reflection mirrors 51 to 54, and the like. The document placement glass 41 and the document reading glass are moved by the moving unit 44. 42, the original (illuminated body) placed on the original placing glass 41 is read (first reading mode), or the original conveyed on the original reading glass 42 (irradiated) Body) (second reading mode).

  In the first reading mode, the scanning unit 43 is moved below the document placement glass 41 by the moving unit 44, the document transport device 3 is opened, the document is placed on the document placement glass 41, and the document transport device 3. Close. Then, while the scanning unit 43 is moved by the moving unit 44 in the sub-scanning direction Y by a distance corresponding to the document size at a constant speed, the document on the document placement glass 41 is illuminated by the illumination device 45, and the reflected light is reflected by The light is sequentially reflected by the first to fourth reflecting mirrors 51 to 54 and guided to the imaging lens 46. The imaging lens 46 condenses the reflected light from the document on the CCD 47 and forms an image on the surface of the document on the CCD 47. The CCD 47 repeatedly scans the image on the document surface in the main scanning direction X and reads the image on the document surface.

  In the second reading mode, the scanning unit 43 is moved and positioned below the original reading glass 42 by the moving unit 44, and the original is pulled out from the original placing tray 56 by the original conveying device 3, and the sub scanning is performed on the original reading glass 42. It is conveyed in the scanning direction Y and discharged to the document discharge tray 57. When the original passes over the original reading glass 42, the illumination device 45 of the scanning unit 43 illuminates the original surface through the original reading glass 42, and the reflected light from the original surface is reflected by the first to fourth of the scanning unit 43. The light is sequentially reflected by the reflecting mirrors 51 to 54 and guided to the imaging lens 46, and the reflected light from the document surface is condensed on the CCD 47 by the imaging lens 46 to form an image on the document surface on the CCD 47. Thus, the image on the document surface is repeatedly scanned in the main scanning direction X to read the image on the document surface.

  Next, the illumination device 45 of the scanning unit 43 will be described. FIG. 3 is a perspective view showing the schematic configuration of the illumination device 45 as viewed from above, and FIG. 4 is a perspective view showing the schematic configuration of the illumination device 45 as viewed from below. As shown in FIGS. 3 and 4, in the illuminating device 45, the light guide members 71 are arranged on both sides of the slit St extending in the main scanning direction X, and the LEDs are arranged on the light incident surfaces 71 b at both ends of the light guide members 71. A (light emitting element) 72 is disposed. Instead of the LED, other types of semiconductor elements, light bulbs, and the like may be applied.

  The light guide member 71 has a light-transmitting quadrangular prism shape and is formed of a long light-transmitting main body. Light-transmitting surfaces 71b are formed at both ends in the longitudinal direction Q of the light-transmitting main body, respectively. The light emitting surface 71a is formed on one side surface along the longitudinal direction Q of the main body, and the light reflecting surface 71d and the emitted light amount adjusting unit 71e facing the light emitting surface 71a are formed on the other side surface along the longitudinal direction Q of the translucent main body. Is formed. The light guide member 71 is formed by molding an acrylic resin with a mold.

  As shown in an enlarged view in FIG. 5, the light reflecting surface 71d is a flat surface. In addition, the emitted light amount adjusting unit 71e has a saw blade-like vertical cross-sectional shape, and has a large number of inclined surfaces 71f that form a saw-blade vertical cross-sectional shape. Further, the width F of the emitted light amount adjusting unit 71 e in the direction orthogonal to the longitudinal direction Q of the light guide member 71 is gradually narrowed as it approaches the light incident surfaces 71 b at both ends of the light guide member 71.

  In the illuminating device 45 having such a configuration, the LEDs 72 are opposed to the light incident surfaces 71 b at both ends of the light guide member 71, so that the light emitted from each LED 72 is the light incident surface of the light guide member 71. The light is incident on 71b, guided inside the light guide member 71, and directly emitted from the light emitting surface 71a, or reflected by the light reflecting surface 71d or the emitted light amount adjusting unit 71e and emitted from the light emitting surface 71a. At this time, the sawtooth-shaped emitted light amount adjusting unit 71e is diffusely reflected and emitted from the light emitting surface 71a after being guided inside the light guide member 71 and incident on the emitted light amount adjusting unit 71e.

  The light emission surface 71a of each light guide member 71 is directed to the same location of the document via the document placement glass 41 or the document reading glass 42, and is emitted from the light emission surface 71a of each light guide member 71. Is incident on the same portion of the document, the portion of the document is illuminated, the reflected light reflected at that portion of the document is guided to the inside of the scanning unit 43 through the slit St, and the reflected light is reflected from the first to the first. The light is sequentially reflected by the four reflecting mirrors 51 to 54 and enters the CCD 47 through the imaging lens 46, and the image on the surface of the original is read by the CCD 47.

  In addition, the light amount reflected near the center of the emitted light amount adjusting unit 71e is gradually reduced as the width F of the emitted light amount adjusting unit 71e of the light guide member 71 is gradually reduced toward the light incident surfaces 71b at both ends of the light guide member 71. Is adjusted to increase the amount of emitted light in the vicinity of the center of the light guide member 71, and the received light amount distribution received by the light receiving surface of the CCD 47 is made uniform.

  By the way, in the illuminating device 45, each LED 72 is provided in the vicinity of the light incident surfaces 71 b at both ends of the light guide member 71. However, since the light guide member 71 is made of acrylic resin, the light guide member is generated by the heat generated by each LED 72. 71 may be heated and deformed. Further, in the image reading apparatus 2, since the document reading speed is increased and the amount of light for illuminating the document is increased, the amount of heat generated by each LED 72 tends to increase and the life of each LED 72 tends to decrease.

  Therefore, in the first embodiment, both end portions of the light guide member 71 are projected from both side walls of the housing of the scanning unit 43 to the outside of the housing. Accordingly, both end portions of the light guide member 71 and the respective LEDs 72 are disposed outside the casing of the scanning unit 43, and thereby, the heat radiation efficiency of both end portions of the light guide member 71 and each of the LEDs 72 is improved. Yes.

  Next, the configuration of the scanning unit 43 and the illumination device 45 will be described in more detail. FIG. 6 is an enlarged cross-sectional view of the scanning unit 43. 7 is a perspective view showing the scanning unit 43, and FIG. 8 is an enlarged perspective view showing an end portion of the scanning unit 43. As shown in FIG.

  As shown in FIGS. 6 to 8, the scanning unit 43 includes a housing 61 having an opening on the upper side, a lid-shaped holding member 62 provided in the upper opening of the housing 61, and a lid-shaped holding member. And a CCD substrate 63 provided on a side wall along the longitudinal direction (main scanning direction X) of the housing 61.

  An imaging lens 46 and first to fourth reflection mirrors 51 to 54 are provided inside the housing 61. The lid-shaped holding member 62 substantially covers the upper opening of the housing 61 and holds the lighting device 45. Furthermore, the CCD 47 is mounted on the CCD substrate 63, and the light receiving surface of the CCD 47 faces the inside of the housing 61 through a slit (not shown) formed on the side wall of the housing 61.

  The lid-shaped holding member 62 is formed with two fitting grooves 62a that are long in the main scanning direction X and slits St between the fitting grooves 62a, and light guides to the fitting grooves 62a. A member 71 is fitted. In the illuminating device 45, as shown in FIGS. 3 and 4, the light of each LED 72 is made incident on the light incident surface 71b of the light guide member 71, and the light is emitted from the light output surface 71a of each light guide member 71. Light is irradiated onto the original through the original placement glass 41 or the original reading glass 42. The light reflected by the document passes through the document placement glass 41 or the document reading glass 42 and is guided to the inside of the housing 61 through the slit St of the lid-shaped holding member 62, and the first to fourth reflection mirrors 51 to 54. And sequentially enter the CCD 47 through the imaging lens 46.

  In the image reading apparatus 2, a heat radiating plate 65 that radiates the heat of the LED 72 is provided at the end of the lid-shaped holding member 62.

  Specifically, in addition to the two light guide members 71 and the four LEDs 72, the lighting device 45 is overlapped on two LED substrates 64 each having two LEDs 72 mounted thereon and on the outer surface of each LED substrate 64. It has two heat sinks 65 provided.

  FIG. 9 is an enlarged perspective view showing a state where the heat sink 65 is removed and the LED board 64 is exposed, and FIG. 10 is a perspective view of the lid-shaped holding member 62 after the LED board 64 and the heat sink 65 are removed. It is a perspective view which expands and shows the state which exposed the edge part. 11A and 11B are perspective views showing a state in which the LED board 64 and the heat radiating plate 65 are attached to the end of the lid-like holding member 62 as viewed from below.

  As shown in FIGS. 9, 10, 11 </ b> A, and 11 </ b> B, the lid-shaped holding member 62 includes the shielding portions 62 b and 62 c that cover the upper opening of the housing 61 except the slit St, and the shielding portions. 62b and 62c, and connecting portions 62d for connecting the both end portions. Respective fitting grooves 62a (shown in FIG. 6) into which the respective light guide members 71 are fitted are formed in the respective shielding portions 62b and 62c.

  Further, two opening holes 62e communicating with the respective fitting grooves 62a are formed in the connecting portion 62d of the lid-like holding member 62, and the light incident surfaces 71b of the two light guide members 71 are disposed in the respective opening holes 62e. Has been. Further, the light emitting surface 71a of the light guide member 71 facing the document placing glass 41 or the document reading glass 42 is exposed, and the other three side surfaces excluding the light emitting surface 71a of the light guide member 71 are inside the fitting groove 62a. Is arranged.

  Further, the connecting portion 62d of the lid-like holding member 62 is formed with a screw hole 62f located at the center of the connecting portion 62d and two pins 62g and 62h located on both sides of the screw hole 62f. The LED board 64 is made of metal (for example, aluminum), and has one mounting hole 64a and two positioning holes 64b and 64c located on both sides of the mounting hole 64a. Two LEDs 72 are mounted on one side of 64. The heat radiating plate 65 is made of metal (for example, aluminum) and includes a main plate 65a and two side plates 65b bent at both ends of the main plate 65a. The main plate 65a is formed with one mounting hole 65c and two positioning holes 65d and 65e located on both sides of the mounting hole 65c, and a notch 65f is formed on the upper side of each side plate 65b. Has been.

  Here, when the pins 62g and 62h projecting from the connecting portion 62d of the lid-like holding member 62 are inserted into the positioning holes 64b and 64c of the LED substrate 64, and the LED substrate 64 is superimposed on the connecting portion 62d, The LED board 64 is positioned with respect to the connecting part 62d, and the mounting hole 64a of the LED board 64 overlaps the screw hole 62f of the connecting part 62d. Further, each LED 72 on the LED substrate 64 is disposed in each opening hole 62e of the connecting portion 62d, and the light emitting surface of each LED 72 faces the light incident surface 71b of each light guide member 71 inside each opening hole 62e. The light emitted from the light emitting surface of each LED 72 can enter the light incident surface 71 b of each light guide member 71.

  Further, the pins 62g and 62h projecting from the connecting portion 62d of the lid-like holding member 62 are inserted into the two positioning holes 65d and 65e of the main plate 65a of the heat sink 65, and the main plate 65a of the heat sink 65 is connected to the LED. When superposed on the substrate 64, the main plate 65a of the heat radiating plate 65 is positioned with respect to the connecting portion 62d and the LED substrate 64, and the mounting hole 65c of the main plate 65a of the heat radiating plate 65 is connected to the mounting hole 64a of the LED substrate 64 and the connecting portion 62d. It overlaps with the screw hole 62f. In this state, the screw 73 is passed through the mounting hole 65c of the main plate 65a of the heat radiating plate 65 and the mounting hole 64a of the LED substrate 64 and screwed into the screw hole 62f of the connecting portion 62d to be fastened. Is fixed to the connecting portion 62d. The heat radiating plate 65 and the LED substrate 64 are fixed to both of the connecting portions 62 d at both ends of the lid-shaped holding member 62, and the respective LEDs 72 are arranged to face the light incident surfaces 71 b at both ends of each light guide member 71. .

  In the illuminating device 45 having such a configuration, as is apparent from FIGS. 6 to 10, FIG. 11A, and FIG. 11B, both ends of the shielding portions 62 b and 62 c of the lid-like holding member 62 are Projecting from both side walls to the outside of the housing 61, and connecting portions 62d provided at both ends of the shielding portions 62b and 62c also project to the outside of the housing 61. Further, a slit St between the shielding portions 62b and 62c is formed. It extends from both side walls of the casing 61 to the outside of the casing 61.

  Each light guide member 71 is fitted and held in the fitting groove 62 a of each shielding portion 62 b and 62 c of the lid-like holding member 62, and both end portions of each light guide member 71 are on both sides of the lid-like holding member 62. It extends to each connecting part 62d. For each connecting portion 62d, the light incident surfaces 71b of the two light guide members 71 are disposed in the respective opening holes 62e of the connecting portion 62d, and the LED substrate 64 and the heat radiating plate 65 are attached to the connecting portion 62d. Each LED 72 on 64 is arrange | positioned at each opening hole 62e of the connection part 62d. Therefore, both end portions of the two light guide members 71, the LEDs 72, the two LED substrates 64, and the two heat sinks 65 are disposed outside the housing 61.

  Here, when each LED 72 on the LED substrate 64 generates heat, the heat of each LED 72 is conducted to the heat radiating plate 65 through the LED substrate 64, and the heat of the heat radiating plate 65 is radiated by convection of air. Since the heat radiating plate 65 is disposed outside the housing 61, air convects around the heat radiating plate 65 without stagnation, the heat radiating efficiency of the heat radiating plate 65 is high, the temperature rise of each LED 72 is suppressed, and Thus, the temperature rise at the end of the light guide member 71 is also suppressed. Moreover, since not only the heat sink 65 but the edge part of the light guide member 71, LED board 64, and each LED72 are arrange | positioned on the outer side of the housing | casing 61, the edge part of the light guide member 71, LED board 64, and It is difficult for heat to be accumulated in the vicinity of each LED 72, and the heat dissipation efficiency from these is improved. This also suppresses the temperature rise at the ends of each LED 72 and the light guide member 71.

  More specifically, since the heat radiating plate 65 is disposed outside the housing 61, as shown in FIGS. 8 and 11A, the heat radiating plate 65 has vertical and vertical directions Z1, Z2 and left and right directions (both sides in the horizontal direction). ) Opened in Y1, Y2 and outward direction X1. The up and down directions Z1 and Z2, the left and right directions Y1 and Y2, and the outward direction X1 are orthogonal to each other. As is clear from FIG. 2, in the image reading apparatus 2, there are spaces in the vertical direction Z1 and Z2 and the horizontal direction Y1 and Y2 of the scanning unit 43, and further provided on both sides of the casing 61 of the scanning unit 43. There is also a space between each heat sink 65 and the inner walls on both sides of the housing of the image reading apparatus 2. Accordingly, there is a space in the vertical direction Z1 and Z2, the horizontal direction Y1 and Y2, and the outward direction X1 of each heat radiating plate 65 on both sides of the scanning unit 43.

  For this reason, when each LED 72 generates heat and the temperature of the heat radiating plate 65 rises, the air around the heat radiating plate 65 is heated and quickly convects, and the heat of the heat radiating plate 65 becomes efficient due to the rapid convection of the air. Heat is released.

  Further, since both the LED substrate 64 and the heat radiating plate 65 are made of aluminum, the heat of each LED 72 is well conducted to the heat radiating plate 65 through the LED substrate 64 to be radiated, and the temperature rise of each LED 72 is suppressed. Furthermore, the amount of heat conducted from each LED 72 to the end of each light guide member 71 is suppressed, and the temperature rise at the end of each light guide member 71 is also suppressed.

  11A and 11B, the connecting portion 62d that connects the end portions of the shielding portions 62b and 62c of the lid-like holding member 62 is separated from the side wall of the housing 61, and between the shielding portions 62b and 62c. The slit St extends from the side wall of the casing 61 to the outside of the casing 61, and therefore air convection is generated between the connecting portion 62 d and the side wall of the casing 61 in the vertical direction through the slit St. . Since the vertical air convection generated through the slit St is generated around the connecting portion 62d, the heat of the connecting portion 62d is efficiently radiated, and the heat of each LED 72 arranged in each opening hole 62e of the connecting portion 62d. And the heat of the edge part of each light guide member 71 is hard to collect, and the temperature rise of the edge part of each LED72 and each light guide member 71 is suppressed. Further, the vertical air convection generated through the slit St promotes heat radiation from one side of the LED board 64 facing the side wall of the housing 61, that is, one side of the LED board 64 on which each LED 72 is mounted. The rise is further suppressed, and the temperature rise at the end of each light guide member 71 is further suppressed.

  11A and 11B, since the entire outer surface of each side plate 65b of the heat radiating plate 65 is exposed, the heat of the heat radiating plate 65 is also radiated by the convection of air along the outer surface of each side plate 65b. Is done. Further, the vertical width of the main plate 65a of the heat radiating plate 65 is wider than the vertical width of the LED substrate 64, the upper and lower portions of the inner side surface of the main plate 65a of the heat radiating plate 65 are exposed, and the inner side surfaces of the side plates 65b of the heat radiating plate 65 are almost all. Since it is exposed, the heat of the heat radiating plate 65 is radiated more efficiently by the convection of the air in the vertical direction through the slit St.

  As described above, in the first embodiment, both end portions of the two light guide members 71 are protruded outward from the both side walls of the housing 61, and the slit St of the lid-shaped holding member 62 is also extended outward. Accordingly, the LEDs 72, the two LED boards 64, and the two heat sinks 65 are arranged outside the housing 61 so as to be separated from both side walls of the housing 61. Therefore, air convects around the heat radiating plate 65 without stagnation, the heat radiating efficiency of the heat radiating plate 65 is high, the temperature rise of each LED 72 is suppressed, and the temperature rise at the end of the light guide member 71 is also suppressed. Further, heat hardly accumulates in the vicinity of the end portion of the light guide member 71, the LED substrate 64, and each LED 72, thereby improving the heat radiation efficiency, and this also increases the temperature of the end portions of each LED 72 and the light guide member 71. Is suppressed.

  Next, the image reading device 2 of the second embodiment will be described. The second embodiment is different from the first embodiment in that a light guide member 71A as shown in FIGS. 12A and 12B is used instead of the light guide member 71 of the illumination device 45. .

  In the second embodiment, similarly to the first embodiment, the two light guide members 71A are fitted into the fitting grooves 62a of the lid-like holding member 62, and the light of each LED 72 is sent to each light guide member 71A. The light is incident on the light incident surface 71b, the light is emitted from the light emitting surface 71a of each light guide member 71A, and the light is irradiated onto the original through the document placement glass 41 or the document reading glass 42.

  Similarly to the first embodiment, both ends of the lid-shaped holding member 62 are projected from both side walls of the casing 61 of the scanning unit 43 to the outside of the casing 61, and both ends of each light guide member 71 </ b> A are also connected to the casing 61. The heat dissipation efficiency of both ends of each light guide member 71A and each LED 72 is improved.

  Here, as shown in FIG. 12A, the light guide member 71A has a width of the light guide member 71A in a direction orthogonal to the longitudinal direction Q of the light guide member 71A, and the light incident surfaces 71b at both ends of the light guide member 71A. The width of the light emitting surface 71a of the light guide member 71A and the width F of the emitted light amount adjusting unit 71e are made to coincide with the width of the light guide member 71A. For this reason, the light guide member 71A does not have a surface corresponding to the light reflection surface 71d of the light guide member 71 of FIG.

  Even in such a configuration using the light guide member 71A, the reflected light amount near the center of the emitted light amount adjusting unit 71e is adjusted to increase the emitted light amount near the center of the light guide member 71A. The received light amount distribution received by the surface can be made uniform.

  Next, the image reading device 2 of the third embodiment will be described. The third embodiment is different from the first embodiment in that a light guide member 71B as shown in FIGS. 13A and 13B is used instead of the light guide member 71 of the illumination device 45. .

  In the third embodiment, similarly to the first embodiment, the two light guide members 71B are used by being fitted into the fitting grooves 62a of the lid-like holding member 62. Further, as in the first embodiment, both ends of the lid-shaped holding member 62 are projected from both side walls of the casing 61 of the scanning unit 43 to the outside of the casing 61, and both ends of each light guide member 71 B are also connected to the casing 61. The heat radiation efficiency of both ends of each light guide member 71B and each LED 72 is improved.

  Here, as shown in FIG. 13 (a), the light guide member 71B matches the width F of the emitted light amount adjusting portion 71e in the direction orthogonal to the longitudinal direction Q of the light guide member 71B to the constant width of the light guide member 71B. It has been made. For this reason, the light guide member 71B does not have a surface corresponding to the light reflection surface 71d of the light guide member 71 of FIG.

  Even in the configuration using such a light guide member 71B, the light of each LED 72 is incident on the light incident surface 71b of each light guide member 71B, and the light is emitted from the light output surface 71a of each light guide member 71B. The light can be irradiated almost uniformly on the original through the original placement glass 41 or the original reading glass 42.

  Next, the image reading device 2 of the fourth embodiment will be described. FIG. 14 is an enlarged cross-sectional view of the image reading apparatus 2 according to the fourth embodiment. The fourth embodiment is different from the first embodiment in that only one light guide member 71 of the illumination device 45 is used.

  As shown in FIG. 14, one fitting groove 62a is formed in the lid-shaped holding member 62, and one light guide member 71 is fitted into the fitting groove 62a. Similarly to the first embodiment, both ends of the lid-shaped holding member 62 are projected from both side walls of the casing 61 of the scanning unit 43 to the outside of the casing 61, and both ends of the light guide member 71 are also connected to the casing 61. By projecting to the outside, the heat radiation efficiency of both ends of the light guide member 71 and each LED 72 is improved.

  Even in such a configuration using one light guide member 71, the light of each LED 72 is incident on the light incident surface 71 b of the light guide member 71, and light is emitted from the light output surface 71 a of the light guide member 71. The original can be irradiated almost uniformly on the original through the original placement glass 41 or the original reading glass 42.

  Next, an image reading apparatus 2 according to the fifth embodiment will be described. FIG. 15 is an enlarged cross-sectional view of the image reading apparatus 2 according to the fifth embodiment. Compared with the first embodiment, the fifth embodiment uses only one light guide member 71 of the illuminating device 45 and reflects the light emitted from the light exit surface 71a of the light guide member 71 to enter the original. The difference is that a mirror 74 is added.

  As shown in FIG. 15, one fitting groove 62a is formed in the lid-like holding member 62, and one light guide member 71 is fitted into the fitting groove 62a. What is the light guide member 71 with respect to the slit St? The mirror 74 is inclined and supported on the opposite side. Further, as in the first embodiment, both ends of the lid-shaped holding member 62 are projected from both side walls of the casing 61 of the scanning unit 43 to the outside of the casing 61, and both ends of the light guide member 71 and both ends of the mirror 74 are projected. Is also projected to the outside of the casing 61 to improve the heat dissipation efficiency of both ends of the light guide member 71 and the LEDs 72.

  In such a configuration using the light guide member 71 and the mirror 74, the light of each LED 72 is incident on the light incident surface 71b of the light guide member 71, and the light is emitted from the light output surface 71a of the light guide member 71. The original can be irradiated almost uniformly on the original through the original placement glass 41 or the original reading glass 42. Further, the light emitted from the light emitting surface 71 a of the light guide member 71 can be reflected by the reflecting surface 74 a of the mirror 74 and incident on the document. Thereby, the light emitted from the light emitting surface 71a of the light guide member 71 is efficiently used for illuminating the document. The first to fifth embodiments may be appropriately combined.

  Next, an image reading apparatus according to a sixth embodiment will be described. FIG. 16 is an enlarged cross-sectional view of the image reading apparatus according to the sixth embodiment.

  As shown in FIG. 16, the image reading device 81 of the sixth embodiment is used in the image forming apparatus 1 of FIG. 1 in combination with the document conveying device 3 shown in FIG.

  The image reading device 81 includes a document placing glass 41, a document reading glass 42, a first scanning unit 83, a second scanning unit 84, an imaging lens 85, a CCD (Charge Coupled Device) 86, and the like. The first scanning unit 83 includes an illumination device 91 and a first reflecting mirror 92, and moves on the document placement glass 41 while moving at a constant speed V in the sub-scanning direction Y by a distance corresponding to the document size. The original is illuminated by the illuminating device 91, and the reflected light is reflected by the first reflecting mirror 92 and guided to the second scanning unit 84, thereby scanning the image on the original surface in the sub-scanning direction Y. The second scanning unit 84 includes second and third reflecting mirrors 93 and 94, and follows the first scanning unit 83 while moving at a speed V / 2, while reflecting the reflected light from the document to the second and second. The light is reflected by the three reflecting mirrors 93 and 94 and guided to the imaging lens 85. The imaging lens 85 condenses the reflected light from the document on the CCD 86 and forms an image on the surface of the document on the CCD 86. The CCD 86 repeatedly scans the document image in the main scanning direction.

  The first and second scanning units 83 and 84 are provided with respective pulleys (not shown), and wires (not shown) are bridged between these pulleys, and these wires are driven by a stepping motor. Thus, the first and second scanning units 83 and 84 are moved synchronously.

  When reading the image on the surface of the document being conveyed by the document conveying device 3, the first scanning unit 83 is moved below the document reading glass 42 and the second scanning unit 84 is moved according to the position of the first scanning unit 83. In this state, the document conveying device 3 starts conveying the document, draws the document from the document placing tray 56, conveys the document on the document reading glass 42 in the sub-scanning direction Y, and moves to the document discharge tray 57. Let it drain.

  When the document is conveyed, the illumination device 91 of the first scanning unit 83 illuminates the document surface via the document reading glass 42, and the reflected light from the document surface is reflected on the reflection mirrors of the first and second scanning units 83 and 84. Then, the light is guided to the imaging lens 85, and the reflected light from the document surface is condensed on the CCD 86 by the imaging lens 85, and the image on the document surface is formed on the CCD 86, thereby reading the image on the document surface.

Next, the illumination device 91 of the first scanning unit 83 will be described. FIG. 17 is a side view schematically showing the first scanning unit 83 and the illumination device 91, and FIG. 18 is a perspective view schematically showing the first scanning unit 83 and the illumination device 91 as viewed obliquely from above. is there. As shown in FIGS. 17 and 18 , the first scanning unit 83 includes a housing 101 having a slit St extending in the main scanning direction X, an illumination device 91 supported by the housing 101, and a built-in housing 101. The first reflecting mirror 92 is provided. The illuminating device 91 includes elongated parallel light guide members 102 disposed on both sides of the slit St, and respective LEDs (light emitting elements) disposed to face the light incident surfaces 102a at both ends of each light guide member 102. 103.

  For each light guide member 102, the light of each LED 103 enters the light guide member 102 from the light incident surfaces 102 a at both ends of the light guide member 102, and is emitted from the light exit surface 102 b of the light guide member 102. The light emitted from the light emitting surface 102b of each light guide member 102 is applied to the original through the original placement glass 41 or the original reading glass 42, and the reflected light from the original passes through the original placement glass 41 or the original reading glass 42. The light enters the slit St, and the reflected light enters the first reflection mirror 92 through the slit St.

  In such an illuminating device 91, as shown in FIG. 18, both end portions of each light guide member 102 and each LED 103 are arranged on both outer sides of the casing 101 of the first scanning unit 83. The improvement of the heat dissipation efficiency of both ends and each LED103 is aimed at. In order to support each light guide member 102 and each LED 103 on both outer sides of the casing 101, the same thing as the lid-shaped holding member 62 of the first embodiment may be provided in the opening of the casing 101. In this case, each LED board 64 and each heat sink 65 can be provided on both sides of each light guide member 102. Further, a space is provided around each heat sink 65 to improve the heat dissipation efficiency of each heat sink 65, or the slit St is extended to the outside of the housing 101 to cause air convection through the slit St. Or you may.

  As mentioned above, although preferred embodiment and modification of this invention were described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to the example which concerns. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. It is understood.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Image reading apparatus 3 Document conveying apparatus 4 Printing part 5 Paper feed cassette 11 Optical scanning apparatus 12 Developing apparatus 13 Photosensitive drum 14 Drum cleaning apparatus 15 Charger 17 Fixing apparatus 21 Intermediate transfer belt 26 Secondary transfer apparatus 43 Scanning unit 45 Illuminating device 46 Imaging lens 47, 86 CCD (reading unit)
51-54 1st-4th reflective mirror 61 Case 62 Cover-like holding member (holding member)
63 CCD substrate 64 LED substrate (substrate)
65 Heat Dissipator 71 Light Guide Member 72 LED (Light Emitting Element)
St slit

Claims (10)

An image reading apparatus comprising: a light guide member; a light emitting element disposed on an end side of the light guide member; a reading unit that reads an object to be irradiated; and a housing that supports the light guide member.
A substrate on which the light emitting element is mounted, and a heat dissipation member in contact with the substrate;
A gap is provided between the heat dissipation member and the housing ,
The light guide member is a long light guide member,
The heat dissipating member has a main surface that faces a surface of the substrate opposite to the mounting surface of the light emitting element, and a side surface that intersects the main surface toward the housing side,
An image reading apparatus , wherein a gap is provided between an end of the side surface of the heat radiating member on the housing side and the housing in the longitudinal direction of the light guide member . An image reading apparatus comprising: a light guide member; a light emitting element disposed on an end side of the light guide member; a reading unit that reads an object to be irradiated; and a housing that supports the light guide member.
A substrate on which the light emitting element is mounted, and a heat dissipation member in contact with the substrate;
A gap is provided between the heat dissipation member and the housing,
An image reading apparatus, wherein an end portion of the light guide member is projected from a side end of the housing to the outside of the housing. An image reading apparatus comprising: a light guide member; a light emitting element disposed on an end side of the light guide member; a reading unit that reads an object to be irradiated; and a housing that supports the light guide member.
A substrate on which the light emitting element is mounted, and a heat dissipation member in contact with the substrate;
A gap is provided between the heat dissipation member and the housing,
A holding member that holds the light guide member and the light emitting element is provided in the opening of the casing facing the irradiated body.
An image reading apparatus, wherein an end portion of the holding member is projected together with the light guide member from a side end of the housing to the outside of the housing. The image reading device according to claim 2 or 3 ,
The light guide member is a long light guide member,
The heat dissipating member has a main surface that faces a surface of the substrate opposite to the mounting surface of the light emitting element, and a side surface that intersects the main surface toward the housing side,
An image reading apparatus, wherein a gap is provided between an end of the side surface of the heat radiating member on the housing side and the housing in the longitudinal direction of the light guide member. The image reading apparatus according to claim 1 or 3 ,
An image reading apparatus, wherein an end portion of the light guide member is projected from a side end of the housing to the outside of the housing. The image reading apparatus according to claim 1 or 2 ,
A holding member that holds the light guide member and the light emitting element is provided in the opening of the casing facing the irradiated body.
An image reading apparatus, wherein an end portion of the holding member is projected together with the light guide member from a side end of the housing to the outside of the housing. The image reading apparatus according to claim 3 or 6 ,
An image reading apparatus, wherein the holding member is provided with the substrate and the heat radiating member at an end thereof. The image reading device according to claim 3, 6 or 7 ,
The light guide member is a long light guide member,
The holding member is provided along the longitudinal direction of the light guide member, and has a slit that allows the reflected light reflected by the irradiated body to pass into the housing,
An image reading apparatus, wherein the slit extends to the outside of the casing. An image reading apparatus according to any one of claims 1 to 8 , comprising:
Spaces are provided on both sides of the heat radiating member that are orthogonal to the outward direction opposite to the light guide member, the vertical direction of the heat radiating member, the outward direction, and the vertical direction of the heat radiating member. An image reading apparatus characterized by that. An image reading device according to any one of claims 1 to 9 ,
An image forming apparatus comprising: a printing unit that prints an image of the irradiated object read by the image reading device on a recording sheet.

Images