JP2010107757A - Illuminating device, image reader, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reliable illuminating device which accurately radiates irradiating light by preventing influence by stray light, an image reader in which image noise is reduced and an image forming apparatus. <P>SOLUTION: The illuminating device 100 includes a rod type light guiding member 101 having a light radiation surface 101s for radiating the irradiating light LS to the outside in a length direction DL, and a light emitting element 102 arranged to be opposed to the end 101t of the light guiding member 101 and radiating the irradiating light LS to the end 101t of the light guiding member 101. The illuminating device 100 includes a holding member 105 holding the light guiding member 101 and exposing the light radiation surface 101s. Reflectance of the inside 105r of the holding member 105 is made higher than reflectance of the outside 105b of the holding member 105. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an illumination device including a light guide member and a light emitting element, an image reading device to which such an illumination device is applied, and an image forming apparatus.

  Copiers and facsimiles have an image reading device.

  The image reading apparatus includes at least a rod-like light source such as a halogen lamp or a xenon lamp or an LED light source that illuminates the document to read the document placed on the platen glass on which the document is placed, and irradiates the document with irradiation light. It is as a structure to irradiate.

  The image reading apparatus further corresponds to a lamp unit in which a first mirror that converts an optical path of reflected light from a document is disposed, a second mirror that further converts an optical path of reflected light from the lamp unit, and a second mirror. A third mirror that converts the optical path, a lens that forms an image of reflected light, and a solid-state imaging device (CCD) that photoelectrically converts document data imaged according to the reflected light.

  The reflected light from the original irradiated by the light emitted from the rod-shaped light source or LED light source passes through the slit of the frame body to which the rod-shaped light source or LED light source is attached, and the first mirror, the second mirror, the third mirror, and the lens. The image is formed on the solid-state imaging device (line sensor) via the image data, and image data is obtained as an electrical signal.

  Image data imaged on the line sensor is converted into an electrical signal. The image data converted into the electrical signal is subjected to image processing. As image processing, there is a case where image formation (printing) is executed or a case where the image is transmitted to a personal computer connected to a network via a storage device or the like. That is, the image reading apparatus is applied to many uses as image data acquisition means.

  As a light source unit of an image reading apparatus, a light source unit having an LED array formed by arranging a plurality of semiconductor light emitting elements (LEDs) is proposed (for example, see Patent Document 1).

According to the technique of Patent Document 1, the irradiation light from the LED array is reflected by the reflecting member and irradiated toward the reading range of the document via the light guide plate. The reflecting member is made of a material made of metal, glass, or synthetic resin, and uses a highly reflective material such as an aluminum material.
JP 2008-172562 A

  However, such conventional techniques have the following problems.

  When a reflective member is made by applying a material having a high reflectance, the entire surface has a high reflectance, and part of the irradiation light emitted from the LED array becomes stray light, reflected by the reflective member, and the first mirror, the second mirror The light enters the solid-state imaging device (line sensor) via a mirror, a third mirror, or the like.

  When stray light, which is noise relative to the original signal light, is input to the solid-state imaging device, it interferes with the image data as noise, reducing the accuracy of the read image and reducing the accuracy of image formation.

  The present invention has been made in view of such a situation, a rod-shaped light guide member having a light irradiation surface for irradiating irradiation light to the outside, and a light emitting element for irradiating irradiation light to an end of the light guide member. The illumination device includes a holding member that holds the light guide member and exposes the light irradiation surface, and has a light irradiation surface that has a higher reflectance on the inner side of the holding member than a reflectance on the outer side of the holding member. The irradiation light from the light irradiation surface is prevented by effectively irradiating the irradiation light from the outside and suppressing the stray light leaking outside from being reflected by the holding member to prevent the influence of the stray light. It is an object to provide a highly reliable lighting device that can be executed easily and with high accuracy.

  The present invention also provides an image reading apparatus including a document placement table on which a document is placed, an illumination device that irradiates the document with irradiation light, and an imaging device that detects reflected light from the document. Another object of the present invention is to provide an image reading apparatus that can read an original with high accuracy and reduce image noise with little influence of stray light caused by the lighting apparatus. .

  In addition, the present invention is an image forming apparatus including an image reading apparatus. By using the image reading apparatus as an image reading apparatus according to the present invention, reading accuracy is high, image forming is performed with high accuracy, and image noise is reduced. Another object of the present invention is to provide an image forming apparatus with reduced image quality.

  The illumination device according to the present invention is a rod-shaped light guide member having a light irradiation surface for irradiating irradiation light to the outside in the length direction, and is disposed to face an end of the light guide member. An illumination device including a light emitting element that irradiates irradiation light to an end portion, and includes a holding member that holds the light guide member and exposes the light irradiation surface, and the reflectance inside the holding member is the holding It is characterized by being higher than the reflectance on the outside of the member.

  With this configuration, it is possible to reflect the irradiation light irradiated from the light emitting element to the holding member inside the holding member and effectively radiate the light irradiation surface to the outside, and stray light leaking to the outside can be emitted from the holding member. Therefore, it is possible to prevent the influence of stray light from being reflected on the light, so that the light irradiation from the light irradiation surface can be performed easily and with high accuracy, and a highly reliable lighting device is obtained. be able to.

  In the lighting device according to the present invention, the holding member surrounds the light guide member in a shape that is disposed along the light guide member in the length direction and exposes the light irradiation surface. And

  With this configuration, irradiation light introduced into the light guide member can be efficiently irradiated from the light irradiation surface, the light intensity of the irradiation light irradiated from the light irradiation surface can be improved, and irradiation efficiency is high. It can be set as a lighting device.

  In the illumination device according to the present invention, a cross section of the light guide member at a surface intersecting the length direction is rectangular, and one side corresponds to the light irradiation surface, and the length direction The cross-section of the holding member at the surface intersecting with is a U-shape with the light irradiation surface exposed.

  With this configuration, it is possible to effectively execute the irradiation light reflection by the holding member, and the irradiation light can be efficiently irradiated from the light irradiation surface.

  In the lighting device according to the present invention, the outside of the holding member is black.

  With this configuration, reflection of stray light on the outside of the holding member can be reliably prevented, so that an illumination device that suppresses generation of stray light can be obtained.

  Moreover, in the illuminating device according to the present invention, the outer black color is provided by a coating film.

  With this configuration, black can be easily and highly accurately applied to the outside of the holding member, and the lighting device with high productivity and reliability can be obtained.

  Moreover, in the illuminating device according to the present invention, the light source parts formed by the light guide member and the holding member are paired and arranged symmetrically.

  With this configuration, it is possible to improve the uniformity of the irradiation light from the light source unit to the irradiation target region, and it is possible to improve the accuracy of the reflected light from the irradiation target region.

  Moreover, in the illuminating device which concerns on this invention, it is provided with the connection part which connects a pair of said light source parts mutually, and the slit part formed in the said length direction between a pair of said light source parts, It is characterized by the above-mentioned. .

  With this configuration, the positional relationship between the pair of light sources can be defined with high accuracy, and the reflected light from the irradiation target region can be passed through the slit portion, so that the reflected light can be detected with high accuracy. It can be set as a lighting device capable of.

  In the lighting device according to the present invention, the holding member is in close contact with the light guide member.

  With this configuration, it is possible to prevent leakage of irradiation light between the light guide member and the holding member, so that reflection by the holding member can be efficiently generated.

  In the illumination device according to the present invention, the light emitting element is mounted on an element substrate, and the element substrate is in contact with a heat radiating plate.

  With this configuration, it is possible to improve the heat dissipation of the light-emitting element, and thus a lighting device having excellent heat dissipation characteristics can be obtained.

  Further, the lighting device according to the present invention is characterized by including a reflecting member disposed in close contact with the inside of the holding member, and the reflecting member being in close contact with the light guide member.

  With this configuration, the irradiation light introduced from the light emitting element to the light guide member can be efficiently reflected by the reflection member, and the irradiation light can be efficiently irradiated from the light irradiation surface.

  In the illumination device according to the present invention, the light emitting element is mounted on an element substrate, and the element substrate is in contact with a heat radiating plate.

  With this configuration, it is possible to improve the heat dissipation of the light-emitting element, and thus a lighting device having excellent heat dissipation characteristics can be obtained.

  Moreover, in the illuminating device which concerns on this invention, the said reflection member is integrated with the said heat sink.

  With this configuration, the heat dissipation area of the heat sink can be substantially enlarged by the reflecting member to reduce the thermal resistance of the heat sink, so that the lighting device having excellent heat dissipation characteristics can be obtained.

  Further, in the lighting device according to the present invention, the holding member and the light emitting element are positioned in correspondence with each other, and the heat radiating plate in contact with the element substrate is positioned and fastened to the unit base. It is characterized by that.

  With this configuration, the light guide member can be positioned with high accuracy with respect to a unit base that can be applied to the image reading device. Therefore, the irradiation light can be applied to the image reading device with high accuracy. It can be set as the illuminating device which can be irradiated with respect to.

  In the illumination device according to the present invention, the light emitting element is a semiconductor light emitting element.

  With this configuration, since the semiconductor light emitting element is applied, a lighting device with high irradiation efficiency can be obtained.

  In addition, an image reading apparatus according to the present invention includes a document placement table on which a document is placed, an illumination device that is disposed opposite to the document placement table and irradiates the document with irradiation light, and detects reflected light from the document. An image reading apparatus including the imaging device, wherein the illumination device is an illumination device according to the present invention.

  With this configuration, it is possible to obtain an image reading apparatus in which an original is read with high accuracy and image noise is reduced with little influence of stray light caused by the illumination device.

  In the image reading apparatus according to the present invention, the light guide members are arranged as a pair symmetrically with respect to the vertical plane of the document.

  With this configuration, it is possible to make the irradiation light on the document to be read uniform, and an image reading apparatus capable of reading the document with higher accuracy can be obtained.

  The image forming apparatus according to the present invention is characterized in that the image reading device is the image reading device according to the present invention.

  With this configuration, it is possible to obtain an image forming apparatus that has high reading accuracy, executes image formation with high accuracy, and reduces image noise.

  According to the illuminating device of the present invention, a rod-shaped light guide member having a light irradiation surface for irradiating irradiation light to the outside in the length direction, and an end of the light guide member arranged to face an end portion of the light guide member. An illumination device including a light emitting element that irradiates a portion with irradiation light, a holding member that holds a light guide member and exposes a light irradiation surface, Therefore, it is possible to reflect the irradiation light irradiated from the light emitting element to the holding member on the inner side of the holding member and effectively radiate the light irradiation surface to the outside, and to leak outside. Therefore, it is possible to prevent the stray light from being reflected by the holding member and prevent the influence of the stray light, so that the light irradiation from the light irradiation surface can be performed easily and with high accuracy. There exists an effect that it can be set as a high illuminating device.

  According to the image reading apparatus of the present invention, a document placing table on which a document is placed, an illumination device that is arranged opposite to the document placing table and irradiates the document with irradiation light, and detects reflected light from the document. Since the illuminating apparatus is an illuminating apparatus according to the present invention, the illuminating apparatus is less affected by stray light caused by the illuminating apparatus, and reads an original with high accuracy, thereby reducing image noise. There is an effect that the image reading apparatus can be reduced.

  According to the image forming apparatus of the present invention, the image forming apparatus includes the image reading apparatus. Since the image reading apparatus is the image reading apparatus according to the present invention, the reading accuracy is high, and the image forming is performed with high accuracy. And the image forming apparatus with reduced image noise can be obtained.

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

<Embodiment 1>
Based on FIG. 1 thru | or FIG. 3, the illuminating device which concerns on this Embodiment is demonstrated.

  FIG. 1 is a schematic perspective view showing an outline of the overall configuration of the lighting apparatus according to Embodiment 1 of the present invention.

  FIG. 2 is a schematic perspective view showing an outline of a light source unit constituted by a light guide member and a holding member in the lighting apparatus according to Embodiment 1 of the present invention.

  FIG. 3 is an explanatory view showing an arrangement relationship between the light guide member and the light emitting element in the lighting apparatus according to Embodiment 1 of the present invention, and FIG. The perspective side view which shows arrangement | positioning relation transparently, (B) is an end view which shows the end surface of the cross section by the arrow BB of (A).

  The illumination device 100 according to the present embodiment includes a rod-shaped light guide member 101 having a light irradiation surface 101s that irradiates the irradiation light LS (FIG. 3) to the outside in the length direction DL, and an end 101t of the light guide member 101. And the light emitting element 102 that irradiates the end portion 101t of the light guide member 101 with the irradiation light LS.

  In addition, the lighting device 100 includes a holding member 105 that holds the light guide member 101 and exposes the light irradiation surface 101s, and the reflectance of the inner side 105r of the holding member 105 is higher than the reflectance of the outer side 105b of the holding member 105. It is.

  Therefore, the irradiation light LS irradiated from the light emitting element 102 to the holding member 105 is reflected by the inner side 105r of the holding member 105, and can be effectively irradiated from the light irradiation surface 101s to the outside (irradiation facing region LSA, FIG. 3). Further, the stray light LN (FIG. 3) leaked to the outside can be prevented from being reflected by the holding member 105 and the influence of the stray light LN can be prevented, so that the irradiation light from the light irradiation surface 101 s LS irradiation can be performed easily and with high accuracy, and the lighting device 100 with high reliability can be obtained.

  When the illumination device 100 is applied to the image reading device 200 (see the third embodiment), the irradiation target area LSA becomes a document MS (see the third embodiment) as a target to be irradiated with irradiation light.

  The lighting device 100 according to the present embodiment can increase the reflectance by providing the inner side 105r of the holding member 105 with a reflection characteristic. For example, it is possible to make the reflectance at the inner side 105r higher than the reflectance at the outer side 105b by making the surface of the inner side 105r a mirror finish and making the outer side 105b a satin finish. Further, mirror plating can be applied instead of mirror finishing.

  As the light guide member 101, for example, acrylic resin, polycarbonate, or the like that has high translucency and easy workability can be used. As the holding member 105, a metal material (for example, aluminum) that can maintain high dimensional accuracy can be used.

  By configuring the holding member 105 with a metal material, the inner 105r can be easily mirror-finished, and when the mirror-finish is used, the formation of the reflecting member 107 can be omitted. In addition, when a metal material is applied as the holding member 105, it is possible to perform black processing (see Embodiment 2) on the outer side 105b.

  The holding member 105 is disposed along the light guide member 101 in the length direction DL, and surrounds the light guide member 101 in a shape that exposes the light irradiation surface 101s. Therefore, the irradiation light LS introduced into the light guide member 101 can be efficiently irradiated from the light irradiation surface 101s to the irradiation opposing region LSA, and the light intensity of the irradiation light LS irradiated from the light irradiation surface 101s is improved. Thus, the lighting device 100 with high irradiation efficiency can be obtained.

  The cross section (corresponding to the side surface shown in FIG. 3A) of the light guide member 101 at the surface intersecting the length direction DL is rectangular and one side corresponds to the light irradiation surface 101s. The cross section (corresponding to the side surface shown in FIG. 3A) of the holding member 105 on the surface intersecting the length direction DL is preferably U-shaped with the light irradiation surface 101s exposed. With this configuration, it is possible to effectively perform the reflection of the irradiation light LS by the holding member 105, and the irradiation light LS can be efficiently irradiated from the light irradiation surface 101s.

  The holding member 105 is preferably in close contact with the light guide member 101. With this configuration, it is possible to prevent the irradiation light LS from leaking between the light guide member 101 and the holding member 105, so that reflection by the holding member 105 can be efficiently generated.

  The illuminating device 100 includes a light source unit 100s formed by the light guide member 101 and the holding member 105, and the light source units 100s are paired and arranged symmetrically. Therefore, it is possible to improve the uniformity of the irradiation light LS with respect to the irradiation target area LSA from the light source unit 100s, and it is possible to improve the accuracy of the reflected light LR from the irradiation target area LSA.

  The lighting device 100 including the pair of light source units 100s includes a connecting unit 114 that connects the pair of light source units 100s to each other, and a slit unit 116 that is formed in the length direction DL between the pair of light source units 100s. The connecting portion 114 is formed at a position corresponding to the end portion 101t.

  Accordingly, the positional relationship between the pair of light source units 100s can be defined with high accuracy, and the reflected light LR from the irradiation target region LSA can be passed through the slit 116, so that the reflected light LR can be accurately processed. It can be set as the illuminating device 100 which can be detected.

  The light emitting element 102 is mounted on the element substrate 103, and the element substrate 103 is in contact with the heat radiating plate 110. Therefore, since the heat dissipation of the light emitting element 102 can be improved, the lighting device 100 having excellent heat dissipation characteristics can be obtained. The heat sink 110 is arranged outside the element substrate 103 in the length direction DL.

  In the above description, the reflectance of the inner side 105r of the holding member 105 is increased to provide a reflecting surface. That is, the reflectance of the inner side 105r of the holding member 105 is higher than the reflectance of the outer side 105b of the holding member 105.

  FIG. 3 shows a state in which the holding member 105 includes the reflecting member 107 on the inner side 105r as means for increasing the reflectance of the inner side 105r of the holding member 105.

  In this case, the illumination device 100 according to the present embodiment includes the reflection member 107 disposed in close contact with the inner side 105r of the holding member 105, and the reflection member 107 is in close contact with the light guide member 101. Therefore, the irradiation light LS introduced from the light emitting element 102 to the light guide member 101 can be efficiently reflected by the reflection member 107, and the irradiation light LS can be efficiently irradiated from the light irradiation surface 101s. That is, since the reflection member 107 is sandwiched between the light guide member 101 and the holding member 105 (inner side 105r), stray light may be generated between each of the light guide member 101, the holding member 105, and the reflection member 107. There is no.

  As the reflection member 107, for example, a reflection member (reflection sheet, mirror-finished metal plate (aluminum, SUS, etc.) having a high reflectance can be applied. The formed sheet metal can be formed by sticking to the inner side 105r.

  When the reflecting member 107 is made of a metal material, the holding member 105 can be made of a synthetic resin. When the holding member 105 is made of, for example, black synthetic resin, the reflectance at the outer side 105b can be easily reduced.

  The light-emitting element 102 is a semiconductor light-emitting element, specifically, a semiconductor light-emitting diode (LED: Light Emitting Diode), so that it is possible to emit high-intensity irradiation light LS with low power consumption.

  That is, in this embodiment mode, the light-emitting element 102 is preferably a semiconductor light-emitting element. Since the semiconductor light emitting element is applied, the lighting device 100 with high irradiation efficiency can be obtained.

  The light emitting element 102 is mounted on the element substrate 103 and is disposed to face the end 101 t of the light guide member 101. In addition, a heat radiating plate 110 is in contact with the element substrate 103 in order to dissipate heat generated by the light emitting element 102. The heat sink 110 is arranged outside the element substrate 103 in the length direction DL.

  That is, the illumination device 100 according to the present embodiment includes the element substrate 103 on which the light emitting element 102 is mounted, and the heat radiating plate 110 in contact with the element substrate 103. Moreover, since the heat sink 110 can be comprised with a metal plate, it is preferable that the reflective member 107 and the heat sink 110 comprised with the metal plate are integrated.

  With this configuration, it is possible to reduce the thermal resistance of the heat radiating plate 110 by substantially expanding the heat radiating area of the heat radiating plate 110 by the reflecting member 107, so that the lighting device 100 having excellent heat radiating characteristics can be obtained. it can.

  In addition, each part / each member which comprises the illuminating device 100 (The light source part 100s, the light guide member 101, the light emitting element 102, the element substrate 103, the holding member 105, the reflection member 107, the heat sink 110, the connection part 114, the slit part 116) Are appropriately connected and fixed to and integrated with the unit base 120. Further, the unit base 120 is configured to be applicable to, for example, the image reading apparatus 200 (see Embodiment 3).

  That is, the holding member 105 and the light emitting element 102 (element substrate 103) are positioned corresponding to each other, and the heat sink 110 that is in contact with the element substrate 103 is positioned and fastened to the unit base 120. Therefore, the light guide member 101 can be positioned with high accuracy with respect to the unit base 120 in a form applicable to the image reading apparatus 200 (see Embodiment 3). Thus, the illumination device 100 capable of irradiating the original with the irradiation light with high accuracy can be obtained.

<Embodiment 2>
Based on FIG. 4, the illuminating device which concerns on this Embodiment is demonstrated. Since the basic configuration is the same as that of the lighting device 100 described in Embodiment 1, the reference numerals are used to mainly describe different items.

  FIG. 4 is a schematic side view showing a state of the holding member in the lighting apparatus according to Embodiment 2 of the present invention.

  In lighting device 100 (light source unit 100s) according to the present embodiment, outer side 105b of holding member 105 is black. Therefore, it is possible to reliably prevent the reflection of the stray light LN on the outer side 105b of the holding member 105, so that the lighting device 100 in which the generation of the stray light LN is suppressed can be obtained.

  Further, the black color of the outer side 105 b is given by the coating film 109. Accordingly, it is possible to easily and accurately apply black to the outer side 105b of the holding member 105, and the lighting device 100 with high productivity and reliability can be obtained.

<Embodiment 3>
The image reading apparatus according to the present embodiment will be described with reference to FIGS. About the matter which applies the illuminating device 100 shown in Embodiment 1 and Embodiment 2, a code | symbol may be used suitably and description may be abbreviate | omitted.

  FIG. 5 is a perspective side view showing a schematic configuration of the image reading apparatus according to the third embodiment of the present invention as seen through from the side.

  FIG. 6 is a schematic perspective view showing an outline of an attachment state of the illumination device according to the first embodiment with respect to the image reading device according to the third embodiment of the present invention.

  FIG. 7 is a schematic side view conceptually illustrating the operation of the illumination device in the image reading apparatus according to Embodiment 3 of the present invention.

  The document reading apparatus 200 according to the present embodiment has a document operation unit 202 as an area for manipulating (processing) the document MS, and image data reading for reading an image (image data) of the document MS operated by the document operation unit 202. Unit 204.

  The document operation unit 202 can automatically convey the document MS and read image data. Further, it is possible to read the image data by manually placing the document MS. That is, the manuscript operation unit 202 can operate in two modes, ie, an SPF (single pass feeder) mode and a platen mode, depending on the arrangement state and the conveying state of the manuscript MS, as an image operation mode (document reading mode). is there. Note that the document reading apparatus 200 may operate in only one of the modes.

  In the SPF mode, when the document MS is transported and passed through the surface of the SPF glass 216 with respect to the reading light source unit 240 stopped facing the SPF glass (single pass feeder glass) 216, the reading light source unit 240 The reflected light LR generated by the reflection of the irradiation light LS applied to the document is taken out as an image signal.

  In the platen mode, the reading light source unit 240 is scanned with respect to the original MS that is manually placed on the platen glass 220 and is stationary, and the irradiation light LS irradiated to the original MS from the reading light source unit 240 is reflected along with the scanning. The reflected light LR generated in this manner is extracted as an image signal.

  The manuscript operation unit 202 automatically picks up the manuscript introduction tray 211 on which the manuscript MS is placed and the pick-up for introducing the manuscript MS placed on the manuscript introduction tray 211 into the manuscript conveyance path 215 in order to automatically convey the manuscript MS. A roller 212. The document MS whose image data has been read by the SPF glass 216 is discharged to the document discharge tray 217.

  The document conveyance path 215 is configured to face the SPF glass 216 of the image data reading unit 204 in order to read the image data of the document MS automatically conveyed. When the document MS is placed on the platen glass 220, the reading light source unit 240 scans along the platen glass 220.

  That is, the SPF glass 216 and the platen glass 220 are configured to transmit the irradiation light LS applied to the document MS, and function as a document table on which the reflected light LR from the placed document MS can be taken out. As a configuration.

  The image data reading unit 204 includes a reading frame 230, a reading light source unit 240, and an image signal generating unit 250. The reading frame 230 mechanically holds the reading light source unit 240 and the image signal generating unit 250, and reads the reading light source. The unit 240 and the image signal generation unit 250 have a mechanism unit (not shown) that can scan along the platen glass 220.

  The reading light source unit 240 includes an illumination device 100 (see Embodiments 1 and 2) that irradiates the irradiation light LS to the document MS and a first mirror 241 that converts the optical path of the reflected light LR from the document MS. .

  When the irradiation light LS is irradiated from the reading light source unit 240 (illuminating device 100) to the document MS placed on the SPF glass 216 or the platen glass 220 as the document placement table, the reflected light LR is reflected from the document MS. The first mirror 241 converts the optical path of the reflected light LR and introduces the reflected light LR into the image signal generation unit 250.

  The reflected light LR introduced into the image signal generation unit 250 is input to the solid-state imaging device 258 via the lens 255 whose optical path is changed by the second mirror 252 and the third mirror 253 and forms the reflected light LR. The reflected light LR input to the solid-state imaging device 258 composed of a CCD (charge coupled device) is photoelectrically converted to generate image data as an electrical signal. The solid-state imaging device 258 is formed as a line sensor.

  Since the stray light LN generated by reflecting the irradiation light LS of the illumination device 100 by a surrounding member (for example, a peripheral member such as the reading frame 230) can be absorbed by the holding member 105 having a low reflectance. It is possible to prevent the stray light LN from traveling from the reading light source unit 240 to the image signal generation unit 250 and being detected by the solid-state imaging device 258.

  For example, when a halftone image (gray image) is read, the stray light LN has a high intensity (when a white original is read, the level of the reflected light is high, and therefore the level of the stray light LN may be high). For example, white streaks due to stray light LN are generated.

  However, in the image reading apparatus 200 according to the present embodiment, since the illumination device 100 that suppresses the stray light LN is applied, it is possible to prevent the stray light LN from entering the image signal generation unit 250, and thus based on the image data. It is possible to prevent white streaks that occur when an image is formed.

  As described above, the image reading apparatus 200 according to the present embodiment is arranged so as to face the document placement table (SPF glass 216 / platen glass 220) on which the document MS is placed, and the irradiation light LS. The illumination apparatus 100 that irradiates the document MS and a solid-state imaging device 258 that detects the reflected light LR from the document MS are provided.

  Moreover, the illuminating device 100 is the illuminating device 100 which concerns on Embodiment 1 and Embodiment 2. FIG. Therefore, it is possible to obtain the image reading apparatus 200 in which the reading of the document MS is performed with high accuracy and the image noise is reduced with little influence of the stray light LN caused by the illumination apparatus 100.

  In the image reading apparatus 200 according to the present embodiment, the light guide member 101 is disposed as a pair symmetrically with respect to the vertical plane of the document MS. Therefore, the irradiation light LS for the original MS can be made uniform, and the image reading apparatus 200 capable of reading the original MS with higher accuracy can be obtained.

<Embodiment 4>
The image forming apparatus according to the present embodiment will be described with reference to FIG. In addition, about the matter which applies the illuminating device 100 and the image reading apparatus 200 which were shown in Embodiment 1 thru | or Embodiment 3, a code | symbol may be used suitably and description may be abbreviate | omitted.

  FIG. 8 is a perspective side view showing a schematic configuration of the image forming apparatus according to the fourth embodiment of the present invention as seen through from the side.

  As is well known, the image forming apparatus 300 includes an image reading apparatus 200 (see Embodiment 3) that reads image data, and an image forming main body 301 that forms an image based on the read image data.

  The image forming main body 301 includes an exposure unit 310, a photosensitive developing unit 320, an intermediate transfer belt unit 330, a transfer unit 340, a fixing unit 350, and a paper feeding unit 360, as is well known.

  The exposure unit 310 irradiates the photosensitive developing unit 320 with laser light corresponding to the image data based on the image data. The photosensitive developing unit 320 forms an electrostatic latent image corresponding to the image data based on the laser light, and transfers the electrostatic latent image to the intermediate transfer belt unit 330 to form a transferred image. The intermediate transfer belt unit 330 transfers the transferred image to the transfer unit 340. The transfer unit 340 transfers the transfer image onto the recording paper fed from the paper feeding unit 360 and conveys the recording paper to the fixing unit 350. The fixing unit 350 fixes the image transferred on the recording paper and ends the image formation.

  As described above, the image forming apparatus 300 according to the present embodiment includes the image reading apparatus 200 described in the third embodiment. Therefore, since the stray light LN is suppressed, the image forming apparatus 300 with high reading accuracy, high-precision image formation, and reduced image noise can be obtained.

  Note that the image forming apparatus 300 according to the present embodiment corresponds to color image formation, and the photosensitive developing unit 320 corresponds to each color of black (K), cyan (C), magenta (M), and yellow (Y). Correspondingly, the image reading apparatus 200 and the image forming main body 301 (the photosensitive developing unit 320 and the intermediate transfer belt unit 330) are configured to function.

It is a schematic perspective view which shows the outline of the whole structure of the illuminating device which concerns on Embodiment 1 of this invention. It is a schematic perspective view which shows the outline of the light source part which the light guide member and holding member in the illuminating device which concerns on Embodiment 1 of this invention comprise. It is explanatory drawing which shows the arrangement | positioning relationship of the light guide member and light emitting element in the illuminating device which concerns on Embodiment 1 of this invention, (A) sees through the arrangement | positioning relationship between the light emitting element and light guide member seen from the length direction. FIG. 5B is a perspective side view schematically showing an end surface of a cross section taken along arrows BB in FIG. It is a schematic side view which shows the state of the holding member in the illuminating device which concerns on Embodiment 2 of this invention. It is a see-through | perspective side view which shows the schematic structure of the image reading apparatus which concerns on Embodiment 3 of this invention as the state seen through from the side. It is a schematic perspective view which shows the outline of the attachment state of the illuminating device which concerns on Embodiment 1 with respect to the image reader which concerns on Embodiment 3 of this invention. It is a schematic side view which illustrates notionally the effect | action of the illuminating device in the image reading apparatus which concerns on Embodiment 3 of this invention. FIG. 6 is a perspective side view showing a schematic configuration of an image forming apparatus according to a fourth embodiment of the present invention as seen through from the side.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Illuminating device 100s Light source part 101 Light guide member 101s Light irradiation surface 101t End part 102 Light emitting element (semiconductor light emitting element)
DESCRIPTION OF SYMBOLS 103 Element board | substrate 105 Holding member 105r Inner side 105b Outer side 107 Reflective member 109 Paint film 110 Heat sink 114 Connection part 116 Slit part 120 Unit base 200 Image reading apparatus 202 Original operation part 204 Image data reading part 211 Original introduction tray 212 Pickup roller 215 Document transport path 216 SPF glass (document placement table)
217 Document delivery tray 220 Platen glass (document placement table)
230 Reading Frame 240 Reading Light Source Unit 241 First Mirror 250 Image Signal Generation Unit 252 Second Mirror 253 Third Mirror 255 Lens 258 Solid-State Imaging Device 300 Image Forming Device 301 Image Forming Main Body 310 Exposure Unit:
320 Photosensitive development unit:
330 Intermediate transfer belt unit 340 Transfer unit 350 Fixing unit 360 Paper feed unit DL Length direction LS Irradiation light LR Reflected light LN Stray light LSA Irradiation target area MS Document

Claims (17)

A bar-shaped light guide member having a light irradiation surface for irradiating the irradiation light to the outside in the length direction, and disposed at the end of the light guide member so as to irradiate the end of the light guide member with the irradiation light. A lighting device comprising a light emitting element,
A holding member that holds the light guide member and exposes the light irradiation surface;
An illuminating device characterized in that the reflectivity inside the holding member is higher than the reflectivity outside the holding member. The lighting device according to claim 1,
The said holding member is arrange | positioned along the said light guide member in the said length direction, and surrounds the said light guide member in the shape which exposes the said light irradiation surface. The illuminating device characterized by these. The lighting device according to claim 2,
The cross section of the light guide member at a surface intersecting the length direction is rectangular, and one side corresponds to the light irradiation surface,
The cross section of the said holding member in the surface which cross | intersects the said length direction is made into the U shape which exposed the said light irradiation surface. The illuminating device characterized by the above-mentioned. It is an illuminating device as described in any one of Claim 1 thru | or 3, Comprising:
The lighting device, wherein the outside of the holding member is black. The lighting device according to claim 4,
The illuminating device characterized in that the outer black color is provided by a coating film. It is an illuminating device as described in any one of Claim 1 thru | or 5, Comprising:
The light source part which the said light guide member and the said holding member comprise is made into a pair, and is arrange | positioned symmetrically. The illuminating device characterized by the above-mentioned. The lighting device according to claim 6,
An illuminating device comprising: a coupling unit that couples the pair of light source units to each other; and a slit unit that is formed between the pair of light source units in the length direction. It is an illuminating device as described in any one of Claim 1 thru | or 7, Comprising:
The lighting device, wherein the holding member is in close contact with the light guide member. The lighting device according to claim 8,
The light emitting element is mounted on an element substrate, and the element substrate is in contact with a heat radiating plate. It is an illuminating device as described in any one of Claim 1 thru | or 7, Comprising:
A lighting device comprising: a reflecting member disposed in close contact with the inside of the holding member, wherein the reflecting member is in close contact with the light guide member. The lighting device according to claim 10,
The light emitting element is mounted on an element substrate, and the element substrate is in contact with a heat radiating plate. The lighting device according to claim 11,
The lighting device, wherein the reflecting member is integrated with the heat radiating plate. The lighting device according to claim 9 or 11,
The holding member and the light emitting element are positioned in correspondence with each other, and the heat dissipation plate in contact with the element substrate is positioned and fastened to a unit base. A lighting device according to any one of claims 1 to 13,
The lighting device, wherein the light emitting element is a semiconductor light emitting element. An image reading apparatus includes a document placement table on which a document is placed, an illumination device that is disposed opposite to the document placement table and irradiates the document with irradiation light, and an imaging device that detects reflected light from the document. And
The image reading apparatus, wherein the illumination device is the illumination device according to any one of claims 1 to 13. The image reading apparatus according to claim 14, wherein
The image reading apparatus, wherein the light guide members are arranged as a pair symmetrically with respect to a vertical plane of the document. An image forming apparatus including an image reading device,
The image forming apparatus according to claim 14, wherein the image reading apparatus is the image reading apparatus according to claim 14.

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