JP2017224945A - Image reading device, image forming apparatus, and image transmitting and receiving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image reading device that can suppress deformation of and variation in a holding plate and stably ensure the high position accuracy of an emission surface of a light guide body that affects an illuminance distribution in a main scanning direction.SOLUTION: An optical scanning unit 42 comprises: a light irradiation part 45 that includes a light emitting element substrate 52 and a light guide body 53; a housing 48 that includes a concave part 81 storing mirrors 61 to 65; a holding plate 54 that holds the light guide body 53 while closing part of the concave part 81; and a cover 55 that urges the light guide body 53 toward the holding plate 54. The housing 48 includes a plurality of coupling boss parts 83 that are in at least an inner part of the concave part 81 and at both sides in a main scanning direction and project from an inner bottom surface part 81 of the concave part, and a pair of end plate parts 85 that are in contact with the holding plate 54 at both ends in the main scanning direction. While the holding plate 54 is in contact with the pair of end plate parts 85 and the plurality of boss parts 83, the holding plate 54 and the cover 55 overlapped thereon are coupled integrally onto the plurality of coupling boss parts 83 with a common screw 88.SELECTED DRAWING: Figure 4

Description

  The present invention relates to an image reading apparatus, an image forming apparatus, and an image transmitting / receiving apparatus, and more particularly, to an image reading apparatus having an optical scanning unit, an image forming apparatus including the same, and an image transmitting / receiving apparatus.

  Conventionally, an image reading apparatus that irradiates light on a document surface from a light source, reflects reflected light from the document surface in a predetermined optical axis direction by a plurality of mirrors, and makes it incident on a CCD image sensor or the like. Recently, an image forming apparatus and an image transmission / reception apparatus have been known. In recent years, an apparatus using a light emitting element as a light source has been proposed in order to increase the speed of activation of the light source, save energy, and extend the life.

  In this type of apparatus, there is a case where a light guide that guides light from the light emitting diode to the document surface is sometimes used so as to prevent a uniform illuminance distribution in the main scanning direction from being difficult to be obtained due to insufficient light quantity.

  As such a conventional image reading apparatus, for example, an LED substrate in which a plurality of LEDs are linearly arranged in the main scanning direction on a carriage of an optical scanning unit that reciprocates in the sub-scanning direction, and the light emitting surface of the LEDs are opposed. A light guide that guides an incident surface and incident light to an irradiation area of an irradiated object is supported by a cradle. In this apparatus, the cradle is fastened to the base member of the carriage with screws, and the cover member that covers the LED substrate and the light guide is fastened to the base member or the common cradle (for example, paragraph 0005 of Patent Document 1). And FIG. 5).

  However, in the conventional image reading apparatus, the first fastening portion for fastening the pedestal for positioning and holding the light guide to the base member of the carriage with the screw, and the cover member for the cradle or the base member of the carriage The second fastening portion that is fastened to the head is separately provided. Therefore, there is a problem that not only the configuration of the fastening means using the first and second fastening portions is complicated, but also the fastening work takes time.

  On the other hand, for example, a jig that receives pressure can be manufactured and the cover member and the holding member can be fastened first, but this is not desirable because the manufacturing cost of the jig and the assembly process of the apparatus become complicated.

  In the above conventional image reading apparatus, the positioning accuracy of the light guide with respect to the document surface (document image placement surface) decreases due to variations in the fastening state of the two fastening portions. There is also a problem that the illuminance value in the scanning direction is not constant, and the read image noise increases.

  Furthermore, since the pedestal for positioning and holding the light guide body is made of bent sheet metal or the like, its shape accuracy is limited, and it is possible to ensure the support height and mounting angle of the light guide body with high precision. It was not easy, and it was not easy to stably secure the support height and mounting angle of the light guide with high accuracy.

  In addition, since the light guide is supported on the upper end side (document surface side) of the cradle, it is difficult to suppress the height of the light irradiation unit in the optical scanning unit, and the optical scanning unit is used to reduce the size of the apparatus. If the mounting space is reduced, the thickness of the cradle and the cover member in the height direction cannot be sufficiently secured. For this reason, the holding plate and the light guide due to heat generation from the LED substrate are likely to be warped and lifted due to thermal deformation, and also from this point, the support height and the mounting angle of the light guide can be secured stably with high accuracy. It was not easy.

  The present invention has been made to solve the above-described conventional problems, and suppresses deformation and variation of the holding plate, and affects the illuminance distribution in the main scanning direction. An object of the present invention is to provide an image reading apparatus, an image forming apparatus, and an image transmitting / receiving apparatus capable of stably ensuring accuracy.

  In order to achieve the above object, an image reading apparatus according to the present invention provides a light irradiator capable of irradiating light over the entire area in the main scanning direction with respect to the document surface, and the main scanning through the optical system with the light reflected by the document surface. An image reading unit configured to include an image reading unit that receives light in a light receiving region extending in a direction and reads an image on the document surface, and includes an optical scanning unit that optically scans the document surface with light from the light irradiation unit. The light irradiation unit includes a plurality of light emitting elements, a light emitting element substrate extending in the main scanning direction while supporting the plurality of light emitting elements, and light from the light emitting elements over the entire area in the main scanning direction. A light guide that extends in the main scanning direction so as to be guided to the surface side, and the optical system transmits light reflected by the image surface of the document to the image reading unit in a reflection area in the main scanning direction. Toward the predetermined optical path The optical scanning unit includes a housing having a recess that opens to the document surface side to accommodate the mirror and an internal space that forms the predetermined optical path, and at least the recess. A holding plate extending in the main scanning direction so as to hold the light guide, and extending in the main scanning direction so as to cover the light emitting element substrate and the light guide. A cover that biases the light body toward the holding plate, and the housing is at least an inner side of the concave portion and on both sides in the main scanning direction, and an inner bottom surface portion of the concave portion, respectively. A pair of end plate portions that form a receiving surface that contacts the holding plate on both sides in the main scanning direction. The holding plate and the cover overlapping the holding plate are attached to the plurality of fastening boss portions in a state where the holding plate is in contact with the pair of end plate portions and the plurality of boss portions. It is characterized by being integrally fastened on the plurality of fastening boss portions by a common screw to be screwed together.

  With this configuration, in the present invention, the cover that covers the light-emitting element substrate and the light guide body is disposed on the holding plate that holds the light guide body while urging the light guide body toward the holding plate. In a state where the holding plate, the light emitting element substrate, and the cover are in contact with a pair of end plate portions at both ends of the housing and a plurality of boss portions in a recess for housing a plurality of mirrors on both sides in the main scanning direction. They are fastened together on a plurality of fastening boss portions by screws common to them. Therefore, warpage and lifting of the holding plate and the cover due to heat generation of the light emitting element substrate and the like are further suppressed between these and the housing. Therefore, the deformation of the holding plate and its variation are suppressed, and the pressing posture of the cover against the light guide and the gap between the two members are suppressed from varying in the main scanning direction, which affects the illuminance distribution in the main scanning direction. It is possible to stably ensure high positional accuracy of the light exit surface of the light guide. Furthermore, since the height of the light emitting element substrate, the cover, and the holding plate can be defined without increasing the number of fastening screws, the optical scanning unit can be made compact by space saving.

  In the image reading apparatus of the present invention, the optical system is a reduction optical system that reduces the light reflected by the original surface by a lens disposed on the optical axis and introduces the light into the image reading unit, and the housing Are provided on the inner side of the concave portion and on both outer sides of the optical path in the main scanning direction, with the plurality of fastening boss portions protruding from the inner bottom surface portion of the concave portion to a height contacting the holding plate. It can be set as the structure which has.

  In this case, the width in the main scanning direction in the optical path of the reflected light from the document surface becomes smaller as the light approaches the lens. Therefore, the outer side of the portion where the optical path width in the main scanning direction decreases on the optical path to the lens. The fastening boss portion can be disposed on the image reading apparatus, and the image reading apparatus, which often has the main scanning direction as the depth direction, can be easily downsized.

  In the image reading apparatus of the present invention, the light emitting element substrate is held by the holding plate so that the plurality of light emitting elements face the light guide body, and overlaps the holding plate and the holding plate. The light emitting element substrate and the cover may be integrally fastened on the plurality of fastening boss portions by the common screw.

  In this case, the warp or lift of the holding plate or cover due to the heat generation of the light-emitting element substrate or the warp or lift of the light-emitting element substrate is effectively suppressed between them, and a plurality of light-emitting elements Since the light emitting element substrate having the light guide and the light guide are supported by the same holding plate, the deviation of incident light from the light emitting element to the light guide is reduced, and there is no difference in the illuminance value on the document surface. It becomes a device.

  In the image reading apparatus of the present invention, the pair of end plate portions have a convex or concave shape with respect to the opening-side end surface portion of the concave portion, and the holding plate is at least a subsidiary to the document surface with respect to the holding plate. It is preferable to have a positioning engagement portion that engages with the concave and convex portions so as to be positioned in the scanning direction.

  In this way, the holding position accuracy of the light guide by the holding plate is sufficiently increased in the sub-scanning direction, and the accuracy of the position and inclination of the exit surface of the light guide in the sub-scanning direction is increased. An image reading apparatus that more effectively suppresses variations in illuminance distribution.

  In the image reading apparatus of the present invention, a sponge-like elastic member may be inserted in a compressed state between the cover and the light guide. In this case, the elastic deformation allowance can be set larger than in the case of using a leaf spring or a coil spring, variation in the pressing force for urging the light guide to the holding plate can be suppressed, and damage to the light guide can be prevented. It is also advantageous for downsizing the apparatus.

  An image forming apparatus according to the present invention includes an image reading apparatus having any one of the above-described configurations. Therefore, the deformation and variation of the light guide holding plate can be effectively suppressed, and the high positional accuracy of the light exit surface of the light guide that affects the illuminance distribution in the main scanning direction can be stably secured. The image can be read while suppressing variations in illuminance distribution. Therefore, it is possible to form a good image with reduced density unevenness of the image.

  An image transmitting / receiving apparatus according to the present invention includes an image reading apparatus having any one of the above-described configurations. Therefore, the deformation and variation of the light guide holding plate can be effectively suppressed, and the high positional accuracy of the light exit surface of the light guide that affects the illuminance distribution in the main scanning direction can be stably secured. Therefore, it is possible to read an image with reduced variation in the illuminance distribution in the image, so that it is possible to perform good image transmission with reduced image density unevenness.

  According to the present invention, it is possible to effectively suppress deformation and variation of the holding plate that holds the light guide, and to stably ensure high positional accuracy of the light exit surface of the light guide that affects the illuminance distribution in the main scanning direction. An image reading apparatus, an image forming apparatus, and an image transmitting / receiving apparatus that can be provided can be provided.

1 is a schematic configuration diagram of an image forming apparatus including an image reading apparatus according to an embodiment of the present invention. 1 is a schematic perspective view of an image reading apparatus according to an embodiment of the present invention, in which an optical scanning unit as a main part is hatched. 1 is a plan view of an essential part showing an integrated optical scanning unit in an image reading apparatus according to an embodiment of the present invention; It is MM sectional drawing of FIG. FIG. 5 is a plan view of a principal part showing a state where the cover of the integrated optical scanning unit is removed in the image reading apparatus according to the embodiment of the present invention. FIG. 3 is a top view of a housing of an integrated optical scanning unit in the image reading apparatus according to the embodiment of the present invention. It is explanatory drawing of the optical path area | region of the reading light in the reduction optical system of the image reading apparatus which concerns on one embodiment of this invention. It is explanatory drawing of the arrangement position of the press member in the image reading apparatus which concerns on one embodiment of this invention. FIG. 4 is a perspective view of a principal part showing a state where the cover of the integrated optical scanning unit is removed in the image reading apparatus according to the embodiment of the present invention. FIG. 3 is a perspective view of a main part of a holding plate in the image reading apparatus according to the embodiment of the present invention. FIG. 3 is a perspective view of a main part showing a state in which the cover, the light emitting element substrate, and the light guide of the integrated optical scanning unit in the image reading apparatus according to the embodiment of the present invention are removed. It is the top view which shows the open state of the integrated optical scanning unit in the image reader which concerns on other embodiment of this invention.

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

(One embodiment)
1 to 11 show a schematic configuration of an embodiment of an image reading apparatus according to the present invention and an image forming apparatus having the same.

  In this embodiment, the image reading apparatus of the present invention is either a color copying machine as an image forming apparatus, a facsimile apparatus as an image transmission / reception apparatus, or a multifunction machine having both a copying function and a facsimile function, for example, color copying. The example applied to the machine is shown. Note that the image reading apparatus may be applied to an image scanner. In addition, the image forming apparatus according to the present invention is applicable to image formation of an arbitrary system such as an electrophotographic system or an ink jet recording system, and the image transmitting / receiving apparatus according to the present invention is not limited to facsimile communication, and is capable of reading. The present invention can be applied to any image transmission / reception method for transmitting / receiving image data.

  First, the configuration will be described.

  The color copying machine 1 according to the present embodiment includes an apparatus main body 1M having a paper feeding section 2, an image forming section 3, and a scanner section 4, and an automatic document conveying section 5 disposed above the apparatus main body 1M. . The scanner unit 4 is integrally provided on the uppermost part of the apparatus main body 1M.

  As shown in FIG. 2, the scanner unit 4 includes a contact glass 41 having an upper surface 41a on which an image surface Da of the document D (hereinafter referred to as document surface Da) is set on the uppermost part of the apparatus body 1M, and the contact glass 41. And an optical scanning unit 42 that reciprocates in the sub-scanning direction (arrow B direction) while irradiating the entire area in the main scanning direction (arrow A direction in the figure) with respect to the document surface Da, and the optical scanning unit 42. And a guide rod 43 (see FIG. 11) for reciprocally moving in the sub-scanning direction.

  The optical scanning unit 42 is capable of irradiating at least the entire region in the main scanning direction, and has an optical system such as a mirror that folds and reflects the light reflected from the document surface in the direction of a predetermined optical path. It is held by a moving carriage. The optical scanning unit 42 is reciprocally conveyed in the sub-scanning direction (in the direction of arrow B in FIGS. 1 and 2) by a driving unit (not shown) provided in the scanner unit 4 so that the document placed on the contact glass 41 A two-dimensional color image of D can be exposed and scanned. The driving means is a well-known device including a wire fixed to the optical scanning unit 42, a plurality of driven pulleys and driving pulleys around which the wire is wound, a motor for rotating the driving pulley, and the like.

  Although details will be described later, the optical scanning unit 42 according to the present embodiment is a so-called integrated optical scanning unit, and includes a light source, a lens, a CCD (charge coupled device), and a mirror. Alternatively, the optical scanning unit 42 may integrally hold a light source and a contact image sensor whose longitudinal direction is the main scanning direction.

  The automatic document feeder 5 is hinged to the apparatus main body 1M by a hinge mechanism (not shown) on the back side of the apparatus main body 1M. The automatic document feeder 5 opens the contact glass 41 so that the original can be set or removes the original sheet on the contact glass 41. It can be in a closed state (see FIG. 1) that can be pressed onto the contact glass 41 via a thick plate (not shown).

  The automatic document feeder 5 automatically feeds a document set on the document placement tray 11 to a reading position on the contact glass 41, and manually places the document on the reading position on the contact glass 41. The pressure plate mode can be switched to the closed state.

  The automatic document feeder 5 also separates and feeds the document D from the document tray 11 onto the contact glass 41 one by one, and reads the separated document D on the contact glass 41. The conveyance belt 14 that is conveyed and positioned at the position, and further conveyed in the paper discharge direction, and the document after the image reading at the reading position is linearly conveyed onto the single-sided paper discharge tray 15 and discharged, or both sides are discharged. A paper discharge mechanism unit 19 that discharges paper on the paper discharge tray 16 is provided.

  The color copying machine 1 operates the paper feeding unit 2 and the image forming unit 3 in the apparatus main body 1M in accordance with the reading operation of the original image by the scanner unit 4 to transfer paper fed from the paper feeding unit 2. An image forming operation for copying the image of the document surface Da to P is executed.

  For example, the sheet feeding unit 2 can feed a cut sheet-like transfer sheet P having a different sheet size from any one of a plurality of stages of sheet feeding cassettes 21A, 21B, and 21C.

  The image forming method of the image forming unit 3 is not particularly limited, but the image forming unit 3 includes, for example, an exposure device 31, a plurality of photosensitive drums 32, cyan (C), magenta (M), yellow ( A plurality of developing devices 33 filled with toners of Y) and black (K), a primary transfer unit 34, a secondary transfer unit 35, and a fixing unit 36 are provided.

  For example, the exposure apparatus 31 generates laser light L for each color exposure based on the image read by the scanner unit 4 and exposes the photoconductor drum 32 of each color, so that the surface layer of each photoconductor drum 32 is exposed. An electrostatic latent image of each color corresponding to the read image can be formed. In addition, the plurality of developing devices 33 can supply the thin-layer toner to the corresponding photosensitive drums 32 so as to be close to each other, and perform development to visualize the electrostatic latent image with the toner.

  In the image forming unit 3, the toner images developed on the plurality of photosensitive drums 32 are primarily transferred to the primary transfer unit 34, and the toner images are transferred to the transfer paper by the secondary transfer unit 35 adjacent to the primary transfer unit 34. Secondary transfer to P. Then, the image forming unit 3 heats and pressurizes the toner image secondarily transferred onto the transfer paper P by the fixing unit 36 to melt the toner image, and fixes and records the color image on the transfer paper P.

  That is, the image forming unit 3 forms an image by color-coding on the plurality of photosensitive drums 32 based on the image information read by the scanner unit 4 and separated by color, and the transfer supplied from the paper feeding unit 2 After the toner on the photosensitive drum 32 is transferred to the paper P in an overlapping manner, the toner of the toner image transferred to the transfer paper P is melted by the fixing unit 36 to fix the color image on the transfer paper P. It has become.

  Since the image forming process itself is well known and will not be described in detail any more, the color copying machine 1 transmits the received image to an image transmission / reception apparatus (not shown) or receives it on the contrary. It also has the functions of an image transmission / reception device.

  As shown in FIGS. 3 to 5 and 7, the optical scanning unit 42 of the scanner unit 4 is capable of irradiating light over the entire area in the main scanning direction with respect to the document surface Da set on the upper surface 41 a of the contact glass 41. Part 45, an optical system 46 that introduces light (image reading light) reflected by document surface Da into image reading unit 47, and a light receiving region that extends light reflected by document surface Da in the main scanning direction via optical system 46. An image reading unit 47 that receives light at Zb (see FIG. 7) and reads a reduced image Db corresponding to the document surface Da is provided.

  As described above, the optical scanning unit 42 of the scanner unit 4 in the present embodiment integrates the main part of the image reading unit 47 in addition to the configuration for optically scanning the document surface Da with the light from the light irradiation unit 45. It is configured as an integrated optical scanning unit.

  Specifically, the light irradiation unit 45 includes a plurality of light emitting elements serving as a light source, for example, a plurality of LEDs 51, and a light emitting element substrate 52 extending in the main scanning direction while supporting the plurality of LEDs 51 on the same straight line on the same plate surface. And a light guide 53 extending in the main scanning direction so as to guide light from the plurality of LEDs 51 to the document surface Da side and the reflector 59 side in the entire region in the main scanning direction. The reflector 59 is a reflecting plate for eliminating shadows due to unevenness of the original.

  The light guide 53 includes an incident surface 53a formed on a single belt-like plane extending in the main scanning direction so that light from the plurality of LEDs 51 is incident, and a document that is an object to be irradiated with light incident from the incident surface 53a. And an emission surface 53b that emits toward the D light irradiation region.

  Further, the optical system 46 mirrors and reflects the light reflected by the document surface Da at each reflection position on the optical path Gp in the direction of a predetermined optical path Gp toward the image reading unit 47 as shown in FIG. 62, 63, 64, 65, and a lens 66 that is disposed on a predetermined optical path Gp and focuses the light from the mirror 65 to form an image on the light receiving region Zb of the image reading unit 47. Yes.

  The optical system 46 is a reduction optical system that reduces the reading light reflected by the document surface Da by the lens 66 and introduces it to the image reading unit 47. Accordingly, the optical path region Gw of the reading light beam that contributes to reading by the image reading unit 47 out of the light reflected by the document surface Da becomes narrower in the main scanning direction as it approaches the lens 66 from the document surface Da as shown in FIG. Thus, among the mirrors 61, 62, 63, 64, 65, the reflection regions R 1, R 2, R 3, R 4, R 5 that reflect the reading light beam are also narrower as they are closer to the lens 66.

  The image reading unit 47 includes an element (photoelectric conversion element) that receives and photoelectrically converts the light collected by the lens 66, for example, a CCD (Charge Coupled Device) 71, and a reading substrate 72 on which the CCD is arranged. Has been. In this embodiment, the CCD 71 and the reading substrate 72 are provided integrally with the optical scanning unit 42, but may be provided in a scanning reading unit (not shown). Further, the optical scanning unit may be one in which an exposure scanning system of the optical scanning unit 42 excluding the image reading unit 47 and a contact image sensor whose longitudinal direction is the main scanning direction are integrally held.

  The optical scanning unit 42 further includes a housing 48 having a recess 81 that opens on the side of the original document Da to accommodate the mirrors 61 to 65 and an internal space 82 that forms a predetermined optical path Gp, and at least a part of the recess 81. A holding plate 54 that is formed in a closing plate shape and extends in the main scanning direction so as to integrally position and hold the light guide 53, and extends in the main scanning direction so as to cover the light emitting element substrate 52 and the light guide 53 and is also guided. A housing 48 or a cover 55 fixed to the holding plate 54 so as to bias the body 53 toward the holding plate 54. In FIG. 4, the light guide 53 has positioning and holding protrusions or protrusions 53 p that protrude toward the holding plate 54, but the manner of holding them integrally is arbitrary.

  The housing 48 is at least inward of the recess 81 and on both sides in the main scanning direction, as shown in FIGS. 3, 6, and 7, the height at which the housing 48 comes into contact with the holding plate 54 from the inner bottom surface portion 81 b of the recess 81. A plurality of fastening boss portions 83 projecting to h and a pair of end plate portions 85 forming respective receiving surfaces 84 that abut against the holding plate 54 on both sides in the main scanning direction, and irradiation from the plurality of fastening boss portions 83. And a side plate portion 87 that forms a receiving surface 86 that comes into contact with the holding plate 54 on one side in the short side direction, which is located on the light original reflection position Gp0 side.

  The holding plate 54 and the cover 55 that overlaps the holding plate 54 are screwed to the plurality of fastening boss portions 83 in a state where the holding plate 54 is in contact with the pair of end plate portions 85 and the plurality of fastening boss portions 83. Are integrally fastened on the plurality of fastening boss portions 83 by a common screw 88 (with a head).

  More specifically, the light-emitting element substrate 52 is held by the holding plate 54 so that the plurality of LEDs 51 face the incident surface 53a of the light guide 53 in their light irradiation direction. The light emitting element substrate 52 and the cover 55 that overlap the plate 54 are integrally fastened on the plurality of fastening boss portions 83 by a common screw 88.

  Further, the housing 48 is a plurality of fastening bosses projecting to the height h that abuts the holding plate 54 from the inner bottom surface portion 81b of the concave portion 81 on both outer sides of the optical path Gp in the main scanning direction inside the concave portion 81. Part 83 is provided.

  Furthermore, the pair of end plate portions 85 protrude from a receiving surface 84 which is an end surface portion on the opening side of the recess 81, so that the holding plate 54 can be positioned at least in the sub-scanning direction with respect to the document surface Da. It has a positioning convex part 85p (positioning engagement part).

  The holding plate 54 has a plurality of both-end side receiving portions 54b and 54c that are stepped and bent into a substantially Z shape with which a pair of end plate portions 85 can come into contact with the inner surface side and the upper surface side. Of these, a pair of substantially U-shaped notches 54v that open to both ends of the holding plate 54 with an inner width corresponding to the pair of positioning projections 85p are formed on the pair of both end receiving portions 54b on one side in the sub-scanning direction. Is formed. The pair of notches 54v is formed on one side in the short direction of the holding plate 54 on the side of the plurality of fastening boss portions 83 with respect to the document reflection position Gp0 of the irradiation light. Note that convex portions in the plate thickness direction may be provided on both end sides of the holding plate 54, and long hole-shaped or slit-shaped positioning concave portions corresponding to the convex portions of the holding plate 54 may be provided on the pair of end plate portions 85 side.

  The pair of both-end receiving portions 54c on the other side in the sub-scanning direction are formed on the pair of end-plate portions 85 on both ends of the light guide plate 53 and in the vicinity of the document reflection position Gp0 of the irradiation light in the sub-scanning direction. It contacts the receiving surface 84.

  As shown in FIGS. 9 to 11, at least the center in the longitudinal direction of the side plate portion 87 is located on the other end side in the sub-scanning direction, which is one side in the short direction of the holding plate 54 on the document reflection position Gp0 side of the irradiation light. Inserted into the upper receiving part 54e that is in contact with the receiving surface 86 on the side and supported by the side plate part 87, and slit-like holes 87a (see FIGS. 9 and 11) formed at both ends in the longitudinal direction of the side plate part 87. A pair of lower receiving portions 54f is provided.

  The holding plate 54 is vertically movable with respect to the side plate portion 87 so that a part of the side plate portion 87 is vertically clamped by the upper receiving portion 54e and the pair of lower receiving portions 54f on one side in the short direction. It can be fitted together.

  When the plurality of both-end side receiving portions 54b, 54c of the holding plate 54 abut on the inner surface side of the pair of end plate portions 85 and the respective receiving surfaces 84, the holding plate 54 is preliminarily provided with the upper receiving portion 54e and the pair of lower receiving portions. After the portion 54f is fitted to the side plate portion 87, the pair of positioning projections 85p are fitted to the pair of notches 54v, thereby being positioned parallel to the housing 48 and at a predetermined position in the short direction. . Further, when the holding plate 54 thus positioned is fastened on the plurality of fastening boss portions 83 at one end in the sub-scanning direction, the pair of both end side receiving portions 54b and 54c are received by the pair of end plate portions 85. The surface 84 is brought into pressure contact with a predetermined contact pressure. Thereby, the holding plate 54 is fixed in a fixed posture with respect to the housing 48 and can hold the light guide 53 in a predetermined position with respect to the housing 48 in a predetermined posture.

  A sponge-like elastic member 56 (pressing member) is inserted between the light guide 53 and the cover 55 in a compressed state. As shown in FIG. The cover 55 is arranged at a central position in the longitudinal direction and at equal intervals that are equally spaced from both sides of the cover 55 in the longitudinal direction and equally divide the specific pressing length region of the light guide 53.

  The plurality of elastic members 56 (pressing members) cooperate with the cover 55 extending in the main scanning direction so as to cover the light emitting element substrate 52 and the light guide 53, and the light guide 53 is sufficiently lower in hardness than the cover 55. And it is a thin plate-like member that is pressed so as to be biased toward the holding plate 54 with a low elastic coefficient.

  The light emitting element substrate 52, the cover 55, and the holding plate 54 are formed with screw insertion holes 52 a, 54 a, 55 a having substantially the same shape at positions corresponding to the plurality of fastening boss portions 83. A plurality of screw insertion holes 52 a, 54 a, 55 a corresponding thereto are positioned in a straight line, and a common screw 88 passes therethrough and is common to an insert nut 83 a embedded in the fastening boss portion 83. Screw 88 is screwed together. The insert nut 83a has a female screw that is screw-coupled to a common screw 88 on the inner peripheral side, and has a retaining shape such as a knurling on the outer peripheral side.

  The housing 48 is formed into a predetermined shape having a mounting portion for the plurality of mirrors 61 to 65, a concave portion 81, an internal space 82, a positioning convex portion 85p, receiving surfaces 84 and 86, etc., by a predetermined synthetic resin, for example, PC (polycarbonate). Thus, it is a molded part molded by a molding technique such as injection molding, and functions as a carriage in the optical scanning unit 42. The internal space 82 of the housing 48 communicates with the concave portion 81 on the side of the original surface Da of the optical path Gp, and on the image reading portion 47 side, a reading-side concave portion that opens to the image reading portion 47 side while accommodating the lens 66 is formed. Yes.

  Similar to the housing 48, the cover 55 is molded into a predetermined shape by a predetermined synthetic resin, for example, PC (polycarbonate) by a molding technique such as injection molding. On the other hand, the holding plate 54 is a pressed sheet metal part.

  The light emitting element substrate 52 may be held in advance on a holding plate 54 that holds the light guide 53 with another screw (not shown).

  Next, the operation will be described.

  In the color copying machine of the present embodiment configured as described above, the holding plate 54 is provided with a pair of end plate portions 85 on both sides of the housing 48 on both sides in the main scanning direction and a plurality of fastening bosses in the recess 81. The holding plate 54, the light emitting element substrate 52 and the cover 55 overlaid on the holding plate 54 are integrally fastened on the plurality of fastening boss portions 83 by a common screw 88 while being in contact with the portion 83. Therefore, the load from the holding plate 54 can be received by the plurality of fastening boss portions 83 and the pair of end plate portions 85, and can also be received by the cover 55.

  Therefore, even if the thickness of the holding plate 54 and the cover 55 in the height direction cannot be sufficiently secured due to restrictions on the device size, the holding plate 54 and the cover 55 due to heat generation of the light emitting element substrate 52 and the like. The warp and the lift of the light emitting element substrate 52 and the warp and the lift of the light emitting element substrate 52 are mutually suppressed between these and the housing 48. Therefore, deformation of the holding plate 54 and variations thereof are suppressed, and the pressing posture of the cover 55 against the light guide 53 and the gap between the two members are suppressed from varying in the main scanning direction. As a result, the positional accuracy of the exit surface 53b of the light guide 53 that affects the illuminance distribution in the main scanning direction can be ensured with high accuracy and stability.

  In addition, in this embodiment, the heights of the light emitting element substrate 52, the cover 55, and the holding plate 54 can be accurately defined without increasing the number of fastening screws 88, so that the optical scanning unit 42 can be made compact by saving space. Can be achieved. That is, if the number of screws for fastening is increased, not only the part cost and assembly man-hours, but also the number of screw fastening portions in the structure (resin molded product) to be the housing 48 must be increased, which is disadvantageous in terms of space. As a result, in the present embodiment, such a problem is solved.

  Further, in the present embodiment, the fastening position by the fastening boss portion 83 of the light irradiation unit 45 is set in the range of the regions Z1 and Z2 outside the optical path Gp of the reading light beam in the main scanning direction, so the main scanning direction is set to the depth. Therefore, it is possible to easily reduce the size of the image reading apparatus that is often set in the direction.

  In other words, in the present embodiment, since the optical system 46 is a reduction optical system that reduces the light reflected by the document surface Da by the lens 66 and introduces it to the image reading unit 47, the reading that proceeds in the optical scanning unit 42 is performed. Of the light, the region Gw in the main scanning direction of the optical path Gp of the reading light beam that is introduced into the image reading unit 47 and used is developed on a plane by folding the plurality of mirrors 61 to 65, as shown in FIG. It is shown as an optical path region Gw of a reading light beam from the original surface Da using the lens 66 to the light receiving region Zb of the CCD 71. In this case, the optical path region Gw of the reading light beam to be used has a width in the main scanning direction that becomes smaller as the light approaches the lens 66. Therefore, the fastening position by the fastening boss portion 83 of the light irradiation unit 45 is read in the main scanning direction. Even if it is set in the range of the areas Z1 and Z2 outside the optical path area Gw of the light beam, the necessary reading light beam is not blocked.

  In the present embodiment, the light emitting element substrate 52 is further held on the holding plate 54 so that the plurality of LEDs 51 face the light guide 53, and the light emitting element substrate 52 that overlaps the holding plate 54. The cover 55 and the cover 55 are integrally fastened on a plurality of fastening boss portions by a common screw 88. Accordingly, the warp and lift of the holding plate 54 and the cover 55 or the warp and lift of the light-emitting element substrate 52 due to heat generation of the light-emitting element substrate 52 are effectively suppressed between them. In addition, since the light emitting element substrate 52 having the plurality of LEDs 51 and the light guide 53 are supported by the same holding plate 54, the deviation of incident light from the plurality of LEDs 51 to the light guide 53 is reduced, and the document surface Image reading with no difference in illuminance values at Da is possible.

  In addition, in the present embodiment, the pair of end plate portions 85 protrude from the receiving surface 84 which is the end surface portion on the opening side of the recess 81, and the holding plate 54 is at least sub-scanned with respect to the document surface Da with respect to the holding plate 54. It has a substantially cylindrical positioning convex portion 85p that can be positioned in the direction. Therefore, the holding position accuracy of the light guide 53 by the holding plate 54 is sufficiently increased in the sub-scanning direction, and the accuracy of the position and the inclination of the emission surface 53b of the light guide 53 in the sub-scanning direction is increased. It is possible to read an image in which the variation in the illuminance distribution above is more effectively suppressed.

  In the present embodiment, since a plurality of sponge-like elastic members 56 are inserted between the cover 55 and the light guide 53 in a compressed state, the plate spring or coil spring made of mylar or the like is used. The elastic deformation allowance can be set large, variation in the pressing force for urging the light guide 53 against the holding plate 54 can be suppressed, and damage to the light guide 53 can be prevented. In addition, since the plurality of elastic members 56 can be compressed until they become sufficiently thin, it is advantageous for downsizing of the apparatus.

  As described above, in the present embodiment, the deformation of the holding plate 54 that holds the light guide 53 and variations thereof are effectively suppressed, and the height of the emission surface 53b of the light guide 53 that affects the illuminance distribution in the main scanning direction is increased. It is possible to provide a color copier 1 that includes a scanner unit 4 that can stably secure positional accuracy and has a function of an image forming apparatus such as a copier and an image transmitting / receiving apparatus such as a facsimile machine.

  In this embodiment, by performing image reading with reduced illuminance distribution variation in the main scanning direction, it is possible to form a good image with reduced image density unevenness, or to suppress image density unevenness. And good image transmission.

(Other embodiments)
FIG. 12 is a plan view showing an optical scanning unit in an image reading apparatus according to another embodiment of the present invention as an open lid with the cover removed.

  Since this embodiment has substantially the same configuration as that of the above-described one embodiment, the same or similar components as those of the embodiment are represented by the corresponding configurations shown in FIGS. Differences from the embodiment will be described below using the reference numerals of the elements.

  In the present embodiment, the arrangement positions of the mirror 62 and the plurality of fastening boss portions 83 shown in FIG. 4 are opposite to those in the embodiment in the sub-scanning direction. That is, the mirror 62 is arranged on the side of the original reflection position Gp0 of the irradiation light from the plurality of fastening boss portions 83, and the mirror 64 is arranged on the side away from the original reflection position Gp0 of the irradiation light from the plurality of fastening boss portions 83. The plurality of fastening boss portions 83 are located between the reflection positions R3 and R4 of the mirrors 63 and 64, which are wider in the light traveling direction than in the case of FIG. 7, and in the optical path region Gw in the main scanning direction of the optical path Gp. Arranged outside.

  Therefore, the interval between the two fastening boss portions 83 in FIG. 12 is narrower than that in the embodiment shown in FIG. 6, and is relatively located on the center side in the main scanning direction.

  Also in this embodiment, the same effect as the above-described one embodiment can be obtained.

  In each of the above-described embodiments, the optical system 46 of the optical scanning unit 42 is a single optical system that covers the entire area in the main scanning direction. However, the reduction optical systems are arranged in parallel so as to be adjacent to each other in the main scanning direction. In such a case, the fastening boss portion may be arranged on the center side in the main scanning direction.

  In each of the above-described embodiments, the optical system 46 of the optical scanning unit 42 is a reduction optical system. However, the optical system 46 is not limited to the reduction optical system, and the apparatus size in the main scanning direction is smaller than that of the reduction optical system. For example, an erecting equal-magnification optical system may be used. Also in this case, the fastening boss portion can be provided outside the optical path region of the reading light to be used, and a pair of end plate portions can be provided outside the fastening boss portion.

  As described above, the present invention effectively suppresses deformation and variation of the holding plate that holds the light guide, and stabilizes the high positional accuracy of the light guide surface that affects the illuminance distribution in the main scanning direction. An image reading apparatus, an image forming apparatus, and an image transmission / reception apparatus that can be secured can be provided. The present invention is useful for an image reading apparatus having an optical scanning unit, an image forming apparatus having the same, and an image transmitting / receiving apparatus in general.

1 Color copier (image forming device, image transmission / reception device)
1M device body 4 scanner unit (image reading device)
5 Automatic Document Conveying Unit 41 Contact Glass 42 Optical Scanning Unit 45 Light Irradiating Unit 46 Optical System (Reduction Optical System)
47 Image reading unit 48 Housing (carriage, molded part)
51 LED (light emitting device)
52 Light-Emitting Element Substrate 52a, 54a, 55a Insertion Hole 53 Light Guide 54 Holding Plate 54b, 54c Both End Side Receiving Portion 54e Upper Receiving Portion 54f Lower Receiving Portion 54v Notch 55 Cover 56 Elastic Member (Pressing Member)
61, 62, 63, 64, 65 Mirror 66 Lens (reduction lens, imaging lens)
71 CCD (photoelectric change device, charge coupled device)
81 Recessed portion 81b Inner bottom surface portion 82 Internal space 83 Fastening boss portion 84, 86 Receiving surface (opening side end surface portion)
85 A pair of end plate parts 85p Convex part (positioning engagement part)
87 Side plate D Document Da Document surface (image image placement surface)
Gp optical path Gw optical path area (optical path area in main scanning direction of reading light to be used)
h Height (projection height)
R1, R2, R3, R4, R5 Reflection area Z1, Z2 Outside area

JP 2015-167409 A

Claims (7)

A light irradiating unit capable of irradiating light on the entire area of the document surface in the main scanning direction and light reflected by the document surface are received by a light receiving region extending in the main scanning direction via an optical system, and an image on the document surface is read An image reading unit, and an optical scanning unit configured to optically scan the document surface with light from the light irradiation unit,
The light irradiator includes a plurality of light emitting elements, a light emitting element substrate that supports the plurality of light emitting elements and extends in the main scanning direction, and emits light from the light emitting elements over the entire area in the main scanning direction. A light guide extending in the main scanning direction so as to lead to
The optical system includes a mirror that reflects light reflected on the image surface of the document in a direction of a predetermined optical path toward the image reading unit in a reflection region in the main scanning direction;
The optical scanning unit is formed in a plate shape that has a recess that opens to the document surface side so as to accommodate the mirror and an internal space that forms the predetermined optical path, and a plate that closes at least a part of the recess. A holding plate extending in the main scanning direction so as to hold the light guide, and extending in the main scanning direction so as to cover the light emitting element substrate and the light guide, and urging the light guide toward the holding plate. And a cover that includes
The housing has a plurality of fastening bosses protruding at a height in contact with the holding plate from the inner bottom surface of the recess at least on the inner side of the recess and on both sides in the main scanning direction, A pair of end plate portions that form receiving surfaces that contact the holding plate on both sides in the main scanning direction, and
A common screw in which the holding plate and the cover overlapping the holding plate are screw-coupled to the plurality of fastening boss portions in a state where the holding plate is in contact with the pair of end plate portions and the plurality of boss portions. The image reading apparatus is integrally fastened on the plurality of fastening boss portions by the above. The optical system is a reduction optical system that reduces the light reflected by the document surface by a lens disposed on the optical axis and introduces the light into the image reading unit;
The housing includes a plurality of fastening boss portions that protrude from the inner bottom surface of the recess to a height that abuts the holding plate on the inner side of the recess and on both outer sides of the optical path in the main scanning direction. The image reading apparatus according to claim 1, further comprising: The light emitting element substrate is held by the holding plate so that the plurality of light emitting elements face the light guide body;
The said holding plate, the said light emitting element board | substrate and the said cover which overlap on this holding plate are integrally fastened on these fastening boss | hub parts by the said common screw, The Claim 1 or 2 characterized by the above-mentioned. The image reading apparatus described.   The pair of end plate portions have a convex or concave shape with respect to the opening side end surface portion of the recess, and the concave and convex engagement is such that the holding plate can be positioned at least in the sub-scanning direction with respect to the document surface with respect to the holding plate. The image reading apparatus according to claim 1, further comprising a positioning engagement portion that performs positioning.   5. The image reading apparatus according to claim 1, wherein a sponge-like elastic member is inserted in a compressed state between the cover and the light guide. 6.   An image forming apparatus comprising the image reading apparatus according to claim 1.   An image transmission / reception apparatus comprising the image reading apparatus according to claim 1.

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