JP2005156600A - Lighting device, image reading apparatus and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain uniform illuminance by preventing generation of an illuminance ripple at a lighting position when a lighting object is lit by a light source by linearly arranging a plurality of point light sources. <P>SOLUTION: A lighting device includes the plurality of linearly arranged point light sources 32, a condensing body 33 that is arranged in front of a direction of the rays emitted from the point light sources 32 and that condenses the rays on a direction to perpendicularly cross arranged directions of the point light source 32 and an optical diffusion part 34 that is arranged on an optical path on which the rays emitted from the point light sources 32 reach the lighting object and diffuses the rays at random. Since the rays emitted from the plurality of point light sources 32 are diffused at random by the optical diffusion part 34 and irradiated on the lighting object, the generation of illuminance ripple resulting from a fact that the light source is the point light sources 32 is prevented and the uniform illuminance is obtained at the lighting position of the lighting object. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

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

  2. Description of the Related Art Conventionally, an image reading apparatus such as a scanner has a light source that is positioned on a contact glass and emits light toward a document surface of a document to be scanned, and is reflected along the scanning optical axis after being reflected by the document surface. The reading light that travels in this manner forms an image on an image reading unit such as a CCD through a lens to read an original image.

  As a light source of such an image reading apparatus, a rod light source such as a fluorescent lamp or a xenon lamp, or a point light source such as an LED is used. By using a point light source such as an LED, it is possible to reduce the size of the image reading apparatus and reduce power consumption.

  When a point light source is used as the light source, a plurality of point light sources are arranged in a straight line in the main scanning direction (reading line direction), so that light emitted from each point light source is read on a reading surface such as a document surface. When the light is directly irradiated, an illuminance ripple (irradiance unevenness) occurs in the main scanning direction, and an image density unevenness caused by an illuminance lip occurs when an image is formed according to the read image data.

  Therefore, various inventions for suppressing the generation of illuminance ripple in an image reading apparatus using a point light source have been proposed. For example, the invention disclosed in Patent Document 1 is known. In the invention of Patent Document 1, illuminance uniformizing means having a diffraction grating is provided between a plurality of point light sources and a document surface of a document as a reading object.

Japanese Patent Laid-Open No. 10-322521

  However, since the invention described in Patent Document 1 is configured to diffract light emitted from a point light source with a diffraction grating, the difference between the maximum illuminance value and the minimum illuminance value of the illuminance ripple is reduced, but the number of ripples is increased. The illuminance ripple still remains.

  An object of the present invention is to obtain a uniform illuminance by preventing the occurrence of an illuminance nipple at an illumination position when an object to be illuminated is illuminated by a light source in which a plurality of point light sources are linearly arranged.

  The illumination device according to claim 1 is arranged in front of a plurality of point light sources arranged linearly and light emitted from the point light source, and the light emitted from the point light source is the point light. A light collector for condensing light in a direction orthogonal to the arrangement direction of the light sources, and a light diffusing unit that is disposed on an optical path where the light emitted from the point light source reaches the illumination target and randomly diffuses the light. It has.

  Therefore, the light emitted from the plurality of point light sources is randomly diffused by the light diffusing unit and irradiated onto the illumination object, and therefore the light source is a point light source at the illumination position of the illumination object. The generation of illuminance ripple is prevented and the illuminance is uniform.

  According to a second aspect of the present invention, in the illuminating device according to the first aspect, the light diffusing unit has a light diffusivity of 80 ± 10% and a light transmittance of 90% or more.

  Therefore, at the illumination position of the object to be illuminated, the occurrence of an illuminance nipple is prevented, uniform illuminance is obtained, and sufficient illuminance is obtained by effectively using the light emitted from the point light source.

  According to a third aspect of the present invention, in the illumination device according to the first or second aspect, the light diffusing unit is configured such that the light emitted from the point light source passes through the light collector and is incident on the light collector or It is formed on at least one surface of the emission surface.

  Therefore, by forming the light diffusing part integrally with the light collector, reduction in the number of parts, miniaturization, and the like are achieved.

  According to a fourth aspect of the present invention, in the illuminating device according to the third aspect, the light diffusion portion is formed on at least one of the incident surface and the emission surface.

  Therefore, since all the light emitted from the point light source is diffused by the light diffusing unit, the generation of the illuminance nipple is effectively prevented.

  According to a fifth aspect of the present invention, in the illuminating device according to the third aspect, the light diffusing portion is intermittently included in a range including a region perpendicular to the point light source on at least one of the incident surface and the emission surface. Is formed.

  Therefore, light that is likely to cause an illuminance nipple at the illumination position among the light emitted from the point light source is light emitted from the point light source in a vertical direction or a direction close to the vertical direction. The diffusion of the light diffusing portion formed in the above prevents the generation of an illuminance nipple at the illumination position. Furthermore, light emitted obliquely from a point light source is unlikely to cause illuminance nipples, and this light is passed through intermittently formed light diffusion sections to illuminate the illumination position, thereby illuminating Increase in illuminance at the position is achieved.

  According to a sixth aspect of the present invention, in the illumination device according to any one of the second to fifth aspects, the light diffusion portion is formed by a surface roughening process.

  Therefore, the formation of the light diffusion portion can be realized by surface roughening treatment. Examples of the surface roughening treatment include sand breast.

  According to a seventh aspect of the present invention, in the illumination device according to any one of the second to fifth aspects, the light diffusion portion is formed by a matte coating process.

  Therefore, the formation of the light diffusion portion can be realized by a matte coating process.

  According to an eighth aspect of the present invention, in the illuminating device according to any one of the second to fifth aspects, the light diffusion portion is formed by a texture treatment.

  Therefore, the formation of the light diffusing portion can be realized by the embossing process. According to the embossing process, the formation of the light collecting body and the formation of the light diffusing portion can be performed at the same time, thereby reducing the number of work steps.

  According to a ninth aspect of the present invention, in the illumination device according to the first or second aspect, the light diffusing portion is formed in a light diffusing member, and the light diffusing member is interposed between the light collector and the illumination object. Has been placed.

  Therefore, the degree of freedom in selecting the material of the light diffusing member is increased, and an optimum light diffusing portion can be formed.

  The invention according to claim 10 is the invention according to claim 9, wherein the light diffusing member is attached to the light collector.

  Therefore, the light collector and the light diffusing member can be aligned with high accuracy.

  According to an eleventh aspect of the present invention, in the illuminating device according to the ninth or tenth aspect, the light diffusing section is formed over the entire optical path of the light emitted from the point light source toward the illumination object.

  Therefore, since all the light emitted from the point light source is diffused by the light diffusing unit, the generation of the illuminance nipple is effectively prevented.

  A twelfth aspect of the present invention is the illumination device according to the ninth or tenth aspect, wherein the light diffusing unit includes a region on an optical path where light emitted from the point light source in a vertical direction is directed to the illumination object. It is formed intermittently.

  Therefore, light that is likely to cause an illuminance nipple at the illumination position among the light emitted from the point light source is light emitted from the point light source in a vertical direction or a direction close to the vertical direction. The diffusion of the light diffusing portion formed in the above prevents the generation of an illuminance nipple at the illumination position. Furthermore, light emitted obliquely from a point light source is unlikely to cause illuminance nipples, and this light is passed through intermittently formed light diffusion sections to illuminate the illumination position, thereby illuminating Increase in illuminance at the position is achieved.

  According to a thirteenth aspect of the present invention, in the illumination device according to any one of the ninth to twelfth aspects, the light diffusion portion is formed by a surface roughening treatment.

  Therefore, the formation of the light diffusion portion can be realized by surface roughening treatment. Examples of the surface roughening treatment include sand breast.

  According to a fourteenth aspect of the present invention, in the illumination device according to any one of the ninth to twelfth aspects, the light diffusion portion is formed by a matte coating process.

  Therefore, the formation of the light diffusion portion can be realized by a matte coating process.

  According to a fifteenth aspect of the present invention, in the illuminating device according to any one of the ninth to twelfth aspects, the light diffusion portion is formed by a texture treatment.

  Therefore, the formation of the light diffusing portion can be realized by the embossing process. According to the embossing process, the formation of the light collecting body and the formation of the light diffusing portion can be performed at the same time, thereby reducing the number of work steps.

  An image reading device according to a sixteenth aspect of the invention is an illumination device according to any one of claims 1 to 15 that illuminates a document surface of a document that is an illumination target, and an image reading unit that reads reflected light from the document surface. And.

  Therefore, according to this image reading apparatus, since the generation of illumination ripple due to illumination light is prevented on the original surface of the original, which is the illumination target, the reading performance of the original surface is improved.

  An image forming apparatus according to a seventeenth aspect includes the image reading device according to the sixteenth aspect and an image forming unit that forms an image on a recording medium in accordance with image data read by the image reading apparatus. .

  Therefore, according to this image forming apparatus, the image data read by the image reading apparatus is improved in reading performance without being affected by the illumination ripple, so that the image quality formed according to the image data is improved. .

  According to the first aspect of the present invention, the light emitted from the plurality of point light sources is randomly diffused by the light diffusing unit and applied to the illumination object, so that the light source is a point light source at the illumination position of the illumination object. It is possible to prevent the occurrence of illuminance ripple caused by the fact that the illuminance is equal, and uniform illumination at the illumination position.

  According to the second aspect of the present invention, it is possible to obtain a uniform illuminance by preventing the generation of an illuminance nipple at the illumination position of the illumination object, and to effectively utilize the light emitted from the point light source. Sufficient illuminance can be obtained.

  According to the third aspect of the present invention, the light diffusing portion is formed integrally with the light collector, so that reduction of the number of parts, miniaturization, and the like can be achieved.

  According to the fourth aspect of the present invention, since all the light emitted from the point light source is diffused by the light diffusing portion, the generation of the illuminance nipple can be effectively prevented.

  According to the fifth aspect of the present invention, it is possible to prevent the occurrence of the illuminance nipple at the illumination position and to increase the illuminance at the illumination position.

  According to invention of Claim 6, formation of a light-diffusion part is realizable by surface roughening process.

  According to invention of Claim 7, formation of a light-diffusion part is realizable by a matt coating process.

  According to the invention described in claim 8, the formation of the light diffusing portion can be realized by the embossing process.

  According to the ninth aspect of the invention, the degree of freedom in selecting the material of the light diffusing member is increased, and an optimal light diffusing portion can be formed.

  According to the tenth aspect of the present invention, alignment between the light collector and the light diffusing member can be performed with high accuracy.

  According to the eleventh aspect of the present invention, since all the light emitted from the point light source is diffused by the light diffusing portion, the generation of the illuminance nipple can be effectively prevented.

  According to invention of Claim 12, generation | occurrence | production of the illumination intensity nipple in an illumination position can be prevented, and the illumination intensity in an illumination position can be aimed at.

  According to invention of Claim 13, formation of a light-diffusion part is realizable by surface roughening process.

  According to invention of Claim 14, formation of a light-diffusion part is realizable by a matt coating process.

  According to the fifteenth aspect of the present invention, the formation of the light diffusing portion can be realized by the embossing process.

  According to the sixteenth aspect of the present invention, it is possible to prevent the occurrence of illumination ripples due to illumination light on the document surface of the document that is the illumination target, and to improve the reading performance of the document surface.

  According to the seventeenth aspect of the present invention, since the reading performance of the image data read by the image reading device is improved without being affected by the illumination ripple, the quality of the image formed according to the image data is improved. be able to.

  A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a schematic front view showing the internal structure of a full-color copying machine 1 which is an image forming apparatus to which the present invention is applied.

  An image forming unit 3 for forming a color image is provided at the center in the apparatus main body 2 of the copying machine 1. The image forming unit 3 includes four drum-shaped photosensitive members 4 that are spaced apart at equal intervals and arranged in parallel in the horizontal direction, a charging roller 5 that uniformly charges the outer peripheral surface of the photosensitive member 4, and a charging roller 5 An exposure device 6 that forms an electrostatic latent image by exposing the outer peripheral surface of each of the photosensitive members 4 charged in accordance with image data according to the image data, and supplying the toner to the electrostatic latent image to convert the electrostatic latent image into a toner image. A developing device 7 that visualizes the toner image, an intermediate transfer belt 8 to which the toner image on the photoconductor 4 is sequentially transferred, and a cleaning that removes toner remaining on the photoconductor 4 after the transfer of the toner image onto the intermediate transfer belt 8. The apparatus 9 includes a transfer roller 10 that transfers the toner image transferred onto the intermediate transfer belt 8 to the recording medium S, and the like. Note that toner images of different colors (Y: yellow, M: magenta, C: cyan, B: black) are formed on the four photoconductors 4, and the toner images of these colors are formed on the intermediate transfer belt 8. By being transferred, a color toner image is formed on the intermediate transfer belt 8, and the color toner image is transferred to the recording medium S.

  On the upper part of the apparatus main body 2, an ADF 11 that automatically feeds a document that is an object to be illuminated by an illuminating device described later, a contact glass 12 on which a document that is an illuminated object by an illuminating device to be described later is placed, and an ADF 11 automatically An image reading device 13 for reading the sent document or the document placed on the contact glass 12 is arranged.

  The image reading device 13 includes first and second traveling bodies 14 and 15 that can run at a speed of 2: 1 in parallel with the contact glass 12, a lens 16, a CCD 17 that is an image reading unit, and the like. The first traveling body 14 includes an illuminating device 18 for illuminating the document surface of the document placed on the contact glass 12 or the document conveyed by the ADF 11, and is reflected on the document surface to be a reading optical axis. A first mirror 19 that reflects the reading light traveling along is mounted. The second traveling body 15 is equipped with a second mirror 20 and a third mirror 21 that further reflect the light reflected by the first mirror 19. A lens 16 and a CCD 17 are disposed in front of the reading light sequentially reflected by the first to third mirrors 19, 20, and 21 in the traveling direction.

  A plurality of, for example, four-stage paper cassettes 24 for storing the recording medium S are provided at the lower part of the apparatus main body 2. The recording media S stored in these paper cassettes 24 are separated and fed one by one by a pickup roller 25 and a feed roller 26, and the separated and fed recording media S are conveyed by a sheet provided in the apparatus main body 2. It is conveyed along the path 27. On the paper conveyance path 27, a registration roller 28, a transfer roller 10, a fixing device 29, a paper discharge roller 30, and the like are disposed.

  In such a configuration, laser light corresponding to the image data of each color (yellow Y, magenta M, cyan C, black B) is emitted from the semiconductor laser of the exposure device 6 according to the reading result by the image reading device 13, An electrostatic latent image is formed by exposing the outer peripheral surface of each photoreceptor 4 to which the laser light is uniformly charged by the charging roller 5. Each color toner is supplied from each developing device 7 to the electrostatic latent image, whereby each color toner image is formed. The toner image on each photoconductor 4 is sequentially transferred onto an intermediate transfer belt 8 that moves in synchronization with the photoconductor 4, and a color toner image is formed on the intermediate transfer belt 8.

  On the other hand, before and after the start of the image forming operation in the image forming unit 3, the recording medium S is started to be separated and fed from the inside of the sheet cassette 24, and the separated and fed recording medium is conveyed on the sheet conveyance path 27. S is timed by a registration roller 28 that rotates intermittently and is sent to a transfer position between the intermediate transfer belt 8 and the transfer roller 10.

  The registration roller 28 is rotated and the recording medium S is sent between the intermediate transfer belt 8 and the transfer roller 10, whereby the color toner image on the intermediate transfer belt 8 is transferred onto the recording medium S. The color toner image transferred onto the recording medium S is fixed to the recording medium S while the recording medium S transported on the paper transport path 27 passes through the fixing device 29, and the color toner image is fixed. The medium S is discharged onto a discharge tray 31 by a discharge roller 30.

  Under such a configuration, characteristic portions of the present embodiment will be described in order.

  FIG. 2 is a front view showing the lighting device 18 and the first mirror 19 mounted on the first traveling body 14. FIG. 3 is an exploded perspective view showing the lighting device 18. The illumination device 18 includes a plurality of point light sources such as LEDs 32, a light collector 33, a light diffusing unit 34, a reflecting plate 35, a light shielding member 36, and the like.

  The LEDs 32 are linearly arranged on the long substrate 37 at equal intervals, and the substrate 37 is positioned in a direction in which the plurality of LEDs 32 are arranged along the main scanning direction during image reading.

  The condensing body 33 is formed in a long shape having a lens 38, a light guide body 39, and a condensing lens 40 that are integrally molded and having substantially the same length as the substrate 37. The light collector 33 is positioned with its long direction aligned with the main scanning direction at the time of image reading, and the light emitted from the plurality of LEDs 32 is transmitted through the light collector 33 and the arrangement direction of the LEDs 32. The light is condensed in an orthogonal direction (sub-scanning direction during image reading).

  The light diffusing unit 34 emits light over the entire surface of an emission surface 33a that emits light from the light collector 33 when the light emitted from the LED 32 passes through the light collector 33 (a surface facing the contact glass 12 in the light collector 33). A diffusion portion 34 is formed. In other words, the light diffusing unit 34 is arranged on the optical path where the light emitted from the LED 32 reaches the document surface of the document that is the illumination target. The light diffusing unit 34 has a function of randomly diffusing the light transmitted through the light collector 33 and emitted from the emission surface 33a.

  The light diffusion portion 34 is formed by surface roughening treatment such as sandblasting or etching, and has a light diffusion degree of 80 ± 10% and a light transmittance of 90% or more.

  The light diffusing portion 34 may be formed by a method other than the surface roughening treatment. For example, a matte coating treatment in which a matting agent containing amorphous silicon dioxide or other fine particles is applied; It can be formed by a texture treatment or the like in which a texture is formed on the inner surface of the mold for forming the texture. Further, with respect to the formation position of the light diffusing portion 34, the incident surface (surface facing the LED 32 in the light collector 33) 33 b of the light when the light emitted from the LED 32 passes through the light collector 33. It may be formed on the entire surface.

  The reflecting plate 35 has substantially the same length as the substrate 37 and the light collector 33 and is formed in a paraboloid shape in which the side facing the light collector 33 is a concave surface, and the concave surface is a side surface in the longitudinal direction of the light collector 33. It is arrange | positioned facing.

  FIG. 4 is a side view for explaining how light emitted from the LED 32 and transmitted through the light collector 33 is randomly diffused by the light diffusing unit 34. The light emitted from the LEDs 32 is collected by the light collecting body 33 in a direction orthogonal to the arrangement direction of the LEDs 32, and is randomly diffused by the light diffusion unit 34 when emitted from the light collecting body 33.

  In such a configuration, the light emitted from the LED 32 passes through the light collector 33 and is transported by the original surface of the document placed on the contact glass 12 after passing through the light collector 33 or by the ADF 11. Irradiates the original surface of the original.

  When the light emitted from the LED 32 passes through the light collector 33, this light is diffused by the light diffusion portion 34 formed on the light emission surface 33 a of the light collector 33. For this reason, at the illumination position on the document surface, the occurrence of an illuminance nipple caused by the fact that the LED 32 is a point light source is prevented, and the illuminance is uniform over the entire region along the main scanning direction of image reading on the document surface.

  For this reason, the occurrence of unevenness in illuminance on the document surface is prevented, the occurrence of unevenness in the density of image data caused by unevenness in the illuminance of the light that illuminates the document surface is prevented, and unevenness in the density of the formed image is generated. Is prevented. As a result, the image formed on the recording medium S does not have a striped pattern due to the illuminance nipple, and a high-quality image can be obtained.

  A second embodiment of the present invention will be described with reference to FIGS. The same parts as those described in FIGS. 1 to 4 are denoted by the same reference numerals, and description thereof is also omitted (the same applies to the following embodiments).

  The basic structure of this embodiment is the same as that of the first embodiment. The present embodiment is different from the first embodiment in that, in the first embodiment, the light diffusing portion 34 is formed on the entire surface of the light exit surface 33a in the light collecting body 33. In this embodiment, the light diffusion portions 34 are formed intermittently at equal intervals along the arrangement direction of the LEDs 32. The position where the light diffusing section 34 is intermittently formed is a range including a region perpendicularly facing the LED 32 when the LED 32 and the light collector 33 are connected and positioned.

  In such a configuration, among the light emitted from the LED 32, light that is likely to cause an illuminance nipple at the illumination position on the document surface is light emitted from the LED 32 in a vertical direction or a direction close to vertical. The light emitted obliquely from the LED 32 is unlikely to cause an illuminance nipple at the illumination position on the document surface. Therefore, the light diffusing portion 34 is intermittently formed on the light exit surface 33a of the light collecting body 33, and the light emitted from the LED 32 in the vertical direction or in a direction close to the vertical is diffused by the light diffusing portion 34, whereby the document Generation of an illuminance nipple at the illumination position on the surface is prevented.

  Further, light that is emitted from the LED 32 in an oblique direction and is unlikely to cause an illuminance nipple at the illumination position on the document surface is directly irradiated to the illumination position on the document surface without being diffused by the light diffusion unit 34. Thus, it is possible to increase the illuminance at the illumination position.

  Also in the present embodiment, the light diffusing portion 34 can be formed by surface roughening treatment, matte coating treatment, embossing treatment, or the like. Further, the light diffusion part 34 may be formed on the incident surface 33 b of the light collector 33.

  A third embodiment of the present invention will be described with reference to FIGS. The basic structure of this embodiment is the same as that of the first embodiment. This embodiment is different from the first embodiment in that the light diffusing portion 34 is formed on the exit surface 33a of the light collector 33 in the first embodiment, whereas in the present embodiment, the light diffusing portion 34 is a collection point. A light diffusing member 41 is provided separately from the light body 33, and a light diffusing portion 34 is formed on the light diffusing member 41. That is, also in the present embodiment, the light diffusing unit 34 is arranged on the optical path where the light emitted from the LED 32 reaches the document surface of the document that is the illumination target. Further, the light diffusing portion 34 is formed on the entire surface of the light diffusing member 41 facing the light exit surface 33 a of the light collector 33.

  Similarly to the light diffusing unit 34 of the first embodiment, the light diffusing unit 34 of the present embodiment is also formed by surface roughening treatment, matte coating treatment, embossing treatment, or the like.

  In such a configuration, also in the present embodiment, since the light diffusing unit 34 is provided on the optical path where the light emitted from the LED 32 reaches the document surface of the document, the light radiated from the LED 32 is transmitted to the light diffusing unit. Since the light is diffused in a random direction at 34 and then irradiated on the original surface of the original, the illumination nipple caused by the LED 32 being a point light source is prevented from occurring at the illumination position on the original, and the image on the original is The illuminance is uniform over the entire area along the main scanning direction of reading.

  For this reason, the occurrence of unevenness in illuminance on the document surface is prevented, the occurrence of unevenness in the density of image data caused by unevenness in the illuminance of the light that illuminates the document surface is prevented, and unevenness in the density of the formed image is generated. Is prevented. As a result, the image formed on the recording medium S does not have a striped pattern due to the illuminance nipple, and a high-quality image can be obtained.

  In the present embodiment, since the light diffusing portion 34 is formed on the light diffusing member 41 provided separately from the light collecting body 33, the degree of freedom in selecting the material of the light diffusing member 41 is increased. The light diffusing member 41 can be formed by selecting an optimal material for forming the light diffusing portion 34, and the light diffusing portion 34 having high performance in terms of light diffusivity and light transmittance is formed. Is possible.

  Then, by improving the performance of the light diffusing unit 34, the quality of the image formed on the recording medium S can be improved.

  A fourth embodiment of the present invention will be described with reference to FIGS. The basic structure of this embodiment is the same as that of the third embodiment. The third embodiment is different from the third embodiment in that the light diffusing portion 34 is formed on the entire surface of the light diffusing member 41 facing the emission surface 33a of the light collector 33 in the third embodiment. On the other hand, in the present embodiment, the light diffusing portion 34 is intermittently formed at equal intervals along the arrangement direction of the LEDs 32 on the surface of the light diffusing member 41 that faces the emission surface 33a of the light collector 33. It is a point. The position where the light diffusing portion 34 is intermittently formed is a range including a region facing the LED 32 perpendicularly when the light diffusing member 41 is connected to the light collector 33 and positioned.

  Similarly to the light diffusing unit 34 in the first to third embodiments, the light diffusing unit 34 in the present embodiment is also formed by surface roughening treatment, matte coating treatment, embossing treatment, or the like.

  In such a configuration, as described in the second embodiment, light that is likely to cause an illuminance nipple at the illumination position on the document surface is emitted from the LED 32 in the vertical direction. Alternatively, the light emitted in the direction close to the vertical direction and the light emitted in an oblique direction from the LED 32 is unlikely to cause an illuminance nipple at the illumination position on the document surface. Therefore, the light diffusing portion 34 formed on the light diffusing member 41 is intermittently formed along the arrangement direction of the LEDs 32, and the light emitted from the LED 32 in the vertical direction or a direction close to the vertical is diffused by the light diffusing portion 34. By doing so, the occurrence of an illuminance nipple at the illumination position on the document surface is prevented.

  Further, light that is emitted from the LED 32 in an oblique direction and is unlikely to cause an illuminance nipple at the illumination position on the document surface is directly irradiated to the illumination position on the document surface without being diffused by the light diffusion unit 34. Thus, it is possible to increase the illuminance at the illumination position.

1 is a front view showing a schematic structure of a copying machine according to a first embodiment of the present invention. It is a front view which shows the illuminating device and 1st mirror mounted in the 1st traveling body. It is a disassembled perspective view which shows an illuminating device. It is a side view explaining a mode that the light radiate | emitted from LED and permeate | transmitted the condensing body is diffused at random in a light-diffusion part. It is a disassembled perspective view which shows the illuminating device of the 2nd Embodiment of this invention. It is a side view explaining a mode that the light radiate | emitted from LED and permeate | transmitted the condensing body is diffused at random in a light-diffusion part. It is a front view which shows the illuminating device and the 1st mirror which are mounted in the 1st traveling body in the 3rd Embodiment of this invention. It is a disassembled perspective view which shows an illuminating device. It is a side view explaining a mode that the light radiate | emitted from LED and permeate | transmitted the condensing body is diffused at random in a light-diffusion part. It is a disassembled perspective view which shows the illuminating device of the 4th Embodiment of this invention. It is a side view explaining a mode that the light radiate | emitted from LED and permeate | transmitted the condensing body is diffused at random in a light-diffusion part.

Explanation of symbols

3 Image forming unit 13 Image reading device 17 Image reading unit 18 Illumination device 32 Point light source 33 Condensing body 34 Light diffusion unit 41 Light diffusion member

Claims (17)

A plurality of point light sources arranged in a straight line;
A light collector that is disposed in front of the emission direction of the light emitted from the point light source and collects the light emitted from the point light source in a direction orthogonal to the arrangement direction of the point light sources;
The light emitted from the point light source is disposed on the optical path leading to the object to be illuminated, and a light diffusing unit that randomly diffuses the light;
A lighting device comprising:   The lighting device according to claim 1, wherein the light diffusion unit has a light diffusion degree of 80 ± 10% and a light transmittance of 90% or more.   The said light-diffusion part is formed in the at least one surface of the entrance plane with respect to the said condensing body when the light radiate | emitted from the said point light source passes the said condensing body, or the output surface of Claim 2 Lighting device.   The lighting device according to claim 3, wherein the light diffusion portion is formed on the entire surface of at least one of the incident surface and the emission surface.   The lighting device according to claim 3, wherein the light diffusing unit is intermittently formed in a range including a region perpendicular to the point light source on at least one of the incident surface and the emission surface.   The lighting device according to claim 2, wherein the light diffusion portion is formed by a surface roughening process.   The lighting device according to claim 2, wherein the light diffusion portion is formed by a matte coating process.   The illuminating device according to claim 2, wherein the light diffusing unit is formed by a texture treatment.   The lighting device according to claim 1, wherein the light diffusion portion is formed on a light diffusion member, and the light diffusion member is disposed between the light collector and the illumination object.   The lighting device according to claim 9, wherein the light diffusion member is attached to the light collector.   The illumination device according to claim 9 or 10, wherein the light diffusing unit is formed in an entire region on an optical path where light emitted from the point light source is directed toward the illumination object.   The lighting device according to claim 9 or 10, wherein the light diffusing unit is intermittently formed in a range including a region on an optical path where light emitted in a vertical direction from the point light source is directed toward the illumination target.   The lighting device according to claim 9, wherein the light diffusion portion is formed by a surface roughening process.   The lighting device according to claim 9, wherein the light diffusion portion is formed by a matte coating process.   The illuminating device according to claim 9, wherein the light diffusing unit is formed by a texture treatment. An illumination device according to any one of claims 1 to 15, which illuminates a document surface of a document that is an illumination object;
An image reading unit that reads reflected light from the document surface;
An image reading apparatus comprising: An image reading apparatus according to claim 16,
An image forming unit that forms an image on a recording medium in accordance with image data read by the image reading device;
An image forming apparatus comprising:

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