JP5101864B2 - Image reading apparatus and image forming apparatus - Google Patents

Description

The present invention relates to an image reading apparatus such as an image scanner, and an image forming apparatus such as a copying machine or a facsimile provided with the image reading apparatus.

An image reading apparatus that reads image data of a document represented on a sheet or the like and provides it for various processes irradiates illumination light emitted from a light source onto the document surface, and uses reflected light reflected on the document surface as reading light as a CCD or the like. It is made to inject into the imaging means provided with the photoelectric conversion device.
As a conventional image reading apparatus, there is an image reading apparatus described in Patent Document 1 that includes a light source lamp such as a fluorescent lamp as a light source. The image reading apparatus disclosed in Patent Document 1 includes a light source lamp having a length that reaches the entire width in the main scanning direction of an area in which an image can be read, and a one-dimensional imaging element that can image the entire area in the main scanning direction. This one-dimensional image sensor receives reading light reflected by a reading region having a full width in the main scanning direction and a limited width in the sub-scanning direction, and picks up an image. Illumination by the light source lamp has a full width of the original surface in the main scanning direction and a somewhat wide width in the sub-scanning direction as an illumination area, and can acquire one-dimensional image information of the original image located in the reading area within the illumination area. Then, the two-dimensional image information of the document image can be acquired by moving the relative position between the document image and the reading area in the sub-scanning direction.

If the light emitted from the light source lamp is viewed on a plane orthogonal to the main scanning direction, light is diffused around the light source lamp, and a part of the light emitted from the light source lamp is incident on the document surface. It is the structure to do. Also, since the document surface is incident at a certain width in the sub-scanning direction, the light incident on the document surface located in the reading area is a part of the light incident on the document surface. In such a configuration using a light source lamp, the light that enters the reading region and contributes to the acquisition of image information is only a part of the light emitted from the light source lamp, and is thus supplied to the light source for light emission. It leads to waste of electricity.
As a configuration that can reduce the waste of power of such a light source, an illumination device that emits light having directivity that concentrates the amount of light within a predetermined width in a specific direction on the illumination target surface (for example, a patent) Some of them have a line light source of Document 2 and irradiate the original light with this illumination light. In the image reading apparatus provided with such an illuminating device, the specific direction on the surface of the original to be illuminated is the sub-scanning direction, and the reading area is within a predetermined width where the light quantity is concentrated in the sub-scanning direction. Constitute. Thereby, only the reading region and its periphery can be illuminated in the sub-scanning direction, light diffusion can be suppressed, and power supplied to the light source for light emission can be used more effectively.

  An illuminating device that emits directional illumination light can effectively use light from a light source for illumination by concentrating the amount of light within a predetermined width in a specific direction on a surface to be illuminated. However, the illuminance may not be uniform over the entire reading area within a predetermined width in the specific direction, and the illuminance may vary on the document surface that is the illumination target surface. This is because even if the illumination light from the light source has directivity, there is a variation in the amount of light that passes depending on the position on the orthogonal cross section of the illumination light that is orthogonal to the optical axis, and the variation is directly reflected in the illuminance on the document surface. It is to be done. In the image reading apparatus of Patent Document 2, since the width of the reading area in the sub-scanning direction, which is a specific direction, is narrow, the sub-scanning direction has little influence on illuminance variation, but the width of the reading area in the main scanning direction is wide. The effect of illuminance variation tends to appear in the scanning direction.

As a configuration capable of suppressing such variations in illuminance on the document surface, there is a configuration including the illumination device described in Patent Document 3. In the illumination device of Patent Document 3, a light source that emits directional illumination light, illumination light dividing means that divides the illumination light into a plurality of divided lights, and an illumination area of the plurality of divided lights on the document surface are on the document surface. Split light guide means for guiding the split light so as to overlap with each other.
The illumination light splitting means provided in the illumination device of Patent Document 3 includes a focusing lens group including a plurality of focusing lenses for focusing the passing light in the main scanning direction and a diverging lens for diverging the passing light. And the same number of diverging lens groups.
The illumination light emitted from the light source is focused toward the focal point of each lens by passing through a plurality of focusing lenses. By passing through the plurality of focusing lenses, the illumination light is split in the main scanning direction as the same number of split lights as the focusing lenses. Further, since the divided light is focused toward the focal point of each converging lens, the diverging lenses are arranged in accordance with the positions of the respective focal points, so that each divided light can be efficiently incident on each diverging lens. Each split light passes through each diverging lens facing each focusing lens, so that the longer the distance to the illumination target surface, the wider the illumination area on the illumination target surface.

The split light guiding means included in the illumination device of Patent Document 3 integrates light refracting so that the optical axis of the incident light is directed to a predetermined position on the document surface, regardless of the position on the light receiving surface. This integrated lens is arranged so that all the divided light beams that have passed through each diverging lens are incident on the light receiving surface thereof. The split lights that have passed through the diverging lenses are refracted by passing through the integrated lenses, respectively, and the intersections of the document surface and the optical axes of the split lights coincide with each other. Thereby, the illumination areas of the respective divided lights can be overlapped on the document surface.
As in the illumination device of Patent Document 3, the illumination light is divided, and the divided illumination light illumination regions are overlapped on the document surface, so that the cross section is orthogonal to the optical axis of the illumination light before passing through the focusing lens group. Even if the amount of light passing through the upper position varies, the illuminance on the document surface can be flat without variation. This is due to the following reason.
If the amount of light passing through the position varies on the cross section perpendicular to the optical axis of the illumination light, the divided light is divided when the illumination light is divided by a plurality of converging lenses arranged in a direction parallel to the cross section. The light quantity varies depending on the position of the focused lens. The split light divided at a position where the amount of light is low illuminates the illumination area on the original surface uniformly with a relatively small amount of light, and the divided light divided at a position where the amount of light is high illuminates the illumination area on the original surface. Illuminates uniformly with a relatively large amount of light. Since the intersection of the original surface and the optical axis of each split light coincides with each other by passing through the integrated lens, the illumination area uniformly illuminated by the split light with a small amount of light and the split light with a large amount of light are used. Thus, the illuminated area overlaps the original surface. On the document surface, the illumination areas uniformly illuminated by the respective divided lights are overlapped with each other and the illumination areas on the document surface are in a flat state without variations.

In the image reading apparatus of Patent Document 3, when the length of the optical path from the integrated lens to the document surface changes, the intersection between the optical axis of each split light and the document surface does not coincide with each other, and the illumination areas on the document surface overlap. There is a risk that the illuminance will vary due to changes in conditions. In addition, when the length of the optical path from the diverging lens group to the original surface changes, the width of the illumination area on the original surface changes, and the amount of light incident on an arbitrary area on the original surface changes. The illuminance on the document surface changes depending on the length. In an image reading apparatus having an illuminating device including such an imaging lens and a diverging lens, the length of the illuminating optical path that is the optical path from the illuminating device to the document surface needs to be kept constant. When the length of the illumination optical path is changed, the illuminance in the main scanning direction on the document surface varies due to the illuminance variation due to the change in the overlapping state of the illumination areas. Further, since the illuminance on the document surface changes depending on the length of the optical path, the illuminance on the document surface varies depending on the reading timing. When the illuminance of the document surface varies as described above, image information having a lightness different from that of the document image is read according to the variation.
In addition, since the imaging device is set so that the focus of the reading light from the document surface becomes the surface of the imaging device, the focus of the reading light and the imaging device change when the length of the optical path from the document surface to the imaging device changes. And the positional relationship changes. In order to keep the positional relationship between the focus of the reading light and the imaging element constant, it is necessary to keep the length of the reading optical path, which is the optical path from the document surface to the imaging device, constant. When the length of the reading optical path changes and the positional relationship between the focus of the reading light and the image sensor changes, even if the image has the same size on the document surface, the length of the optical path is obtained in the image information obtained by imaging. There arises a problem that the image is recognized as an image having a different size.
As described above, if the length of the illumination optical path or the reading optical path changes, it becomes impossible to read a good image. Therefore, it is necessary to keep the lengths of the illumination optical path and the reading optical path constant.

  The image reading apparatus disclosed in Patent Document 3 includes an illuminating unit that illuminates illumination light toward an original surface by an illumination light guide unit that guides illumination light from the illumination apparatus to the original surface, and reading light from the original surface to the imaging device. The reading light guide means has a moving unit including a light receiving unit that receives the reading light reflected from the document surface. This moving unit is movable in the sub-scanning direction parallel to the document surface. In such an image reading apparatus, by moving the moving unit, the irradiation unit and the light receiving unit can be moved with respect to the document surface, and the document image on the document surface can be scanned in the sub-scanning direction.

In this image reading apparatus, since the moving unit moves parallel to the document surface, the distance between the irradiation unit and the light receiving unit and the document surface is constant. For this reason, in order to keep the length of the illumination optical path constant, it is necessary to keep the length of the optical path from the illumination device to the irradiation unit constant, and in order to keep the length of the reading optical path constant, from the light receiving unit It is necessary to keep the length of the optical path to the imaging device constant.
In the image reading apparatus disclosed in Patent Document 3, the illumination device and the image forming apparatus are fixed to the image reading apparatus main body even though the moving unit including the irradiation unit and the light receiving unit moves relative to the apparatus main body. In order to keep the length of the optical path between the illumination device and the image forming device fixed to the apparatus main body and the irradiation unit and the light receiving unit of the moving unit constant, the constituent members of the illumination light guide unit and the reading light guide unit As a second unit with a folding mirror. This second unit can move in the sub-scanning direction, and when the moving unit moves, it moves in the same direction as the moving unit at a moving speed half that of the moving unit. When the illuminating device, the image forming device, and the second unit are in the most distant positional relationship, the moving unit and the second unit are in the closest positional relationship.
Illumination light emitted from the illuminating device fixed to the apparatus main body reaches the irradiation unit in the moving unit via the folding mirror of the second unit. When the moving unit moves and the distance between the lighting device and the irradiation unit approaches by an arbitrary distance, the distance between the lighting device and the folding mirror is reduced by half of the arbitrary distance, and the distance between the folding mirror and the irradiation unit is arbitrary. Separate by half of the distance. Since the distance between the folding mirror and the irradiation unit is the same distance as the distance between the lighting device and the folding mirror is reduced, the length of the illumination optical path from the lighting device to the irradiation unit via the folding mirror is constant. Become. Similarly, the length of the reading optical path from the light receiving unit to the irradiation unit fixed to the apparatus main body via the folding mirror is also constant.
In this way, good image reading can be realized by keeping the lengths of the illumination optical path and the reading optical path constant.

Japanese Patent Laid-Open No. 9-284486 JP-A-10-190990 JP 2006-295914 A

  However, the image reading apparatus described in Patent Document 3 includes two moving bodies, a moving unit and a second unit, and secures a space in which the two moving bodies are arranged and a space in which each moving body is moved in the reading apparatus. Therefore, it is difficult to save space, and there is a problem that the apparatus main body is enlarged.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an image reading apparatus capable of downsizing the apparatus main body while maintaining good image reading performance, and the same. An image forming apparatus is provided.

In order to achieve the above object, the invention according to claim 1 is based on illumination means that emits illumination light, illumination light guide means that guides the illumination light emitted by the illumination means to a document surface, and incident light. An image pickup means for picking up an image; reading light guide means for guiding the reading light reflected by the illumination light on the document surface to the image pickup means; and a moving unit movable in a predetermined direction parallel to the document surface. The moving unit includes an irradiating unit that illuminates the illumination light toward the document surface by the illumination light guide unit, and a light receiving unit that receives the reading light reflected from the document surface by the reading light guide unit. The illumination means includes a light source that emits the directional illumination light, illumination light dividing means for dividing the illumination light into a plurality of divided lights, and respective illumination areas on the document surface of the plurality of divided lights. Divided light guide for guiding the divided light so as to overlap on the original surface In the image reading apparatus and a stage, the mobile unit is said illuminating means, imaging means, comprising a total configuration of the entire structure and said read Tohikari guide means illumination light guide means, as the illumination light guide means, the opposing Two mirror surfaces are provided, and the reading illumination light reciprocates at least once between the two mirror surfaces before the illumination light reaches the original surface from the illumination means. It is.
Also, until the invention of claim 2, in the image reading apparatus according to claim 1, the two mirror surfaces are used as the reading light guide means, the read light reaching the imaging means from the document surface In addition, the reading light is configured to reciprocate between the two mirror surfaces at least once .
Also, the invention of claim 3 is the image reading apparatus according to claim 2, the illumination light guide means, the space where the reading light is reciprocated between the two mirror surfaces in different spatial, guiding the illumination light It is characterized by doing.
According to a fourth aspect of the present invention, in the image reading apparatus according to the third aspect , the boundary between the space where the reading light reciprocates between the two mirror surfaces and the space where the illumination light guiding means guides the illumination light. A mirror surface that can be reflected on both sides is provided .
Also, the invention of claim 5, in the image reading apparatus according to claim 1, 2, 3 or 4, comprising a focusing means for the illumination light guide means for condensing the illumination light, the condenser means Is also provided with a function as the reading light guiding means, and the vicinity of the light collecting means through which the optical axis of the reading light passes is a non-condensing portion that does not have the light collecting function of the light collecting means. Is.
The invention of claim 6 is the image reading apparatus according to claim 1, 2, 3, 4 or 5, provided with focusing means for the illumination light guide means for condensing the illumination light, the condenser The means also has a function as the reading light guiding means, and the reading light is collected at a position through which the optical axis of the reading light passes before the reading light emitted from the condensing means reaches the imaging means. It is characterized by comprising reading light distortion correction means for correcting distortion caused by passing through the optical means.
The invention of claim 7, claim 1, 2, 3, 4, 5 or in the image reading apparatus 6, an image pickup apparatus that is the image pickup means is capable imaging in the main scanning direction entire area of the document A two-dimensional illuminating device as the illuminating means, wherein the illuminating device divides the illuminating light in the main scanning direction and superimposes them on the document surface. Are arranged so as to sandwich the imaging device in the main scanning direction, and the two illumination devices illuminate document surfaces opposite to each other in the main scanning direction with the optical axis of the reading light incident on the imaging device as a boundary. It is comprised so that it may carry out.
The invention of claim 8, claim 1, 2, 3, 4, in the 7 image reading device was 6 or, on a plane perpendicular to the main scanning direction, the optical axis and above the illumination light The optical axis of the reading light is configured to be inconsistent.
The invention of claim 9, in the image reading apparatus according to claim 1,2,3,4,5,6, 7 or 8, the illumination light is to reach the document surface from said illuminating means In the meantime, a focusing means for focusing the illumination light is provided, and the focusing means is a reflecting surface mirror.
According to a tenth aspect of the present invention, in the image reading apparatus according to the ninth aspect, the reflecting mirror is a parabolic mirror.
According to an eleventh aspect of the present invention, in the image reading apparatus according to the ninth aspect, the reflecting mirror is an ellipsoidal mirror.
The invention of claim 12, in the image reading apparatus according to claim 1,2,3,4,5,6,7,8,9,1 0 or 11, on a plane perpendicular to the main scanning direction The angle formed by the optical axis of the illumination light and the document surface, the reflection angle formed by the optical axis of the reading light and the document surface are different from each other, and the optical axis of the illumination light and the optical axis of the reading light Is not symmetric with respect to the normal of the original surface.
The invention of claim 13, in the image reading apparatus according to claim 1,2,3,4,5,6,7,8,9,10,1 1 or 12, the reading light guide means or said The illumination light guide means includes a reflection mirror having a transmission part, and a light emission position at which the illumination means emits the illumination light is arranged at a position facing the back side of the reflection surface of the reflection mirror at a position facing the transmission part. It is characterized by that.
According to a fourteenth aspect of the present invention, there is provided an image forming apparatus comprising: an image reading unit; and an image forming unit that forms an image on a recording medium based on image information read by the image reading unit. , claim 1,2,3,4,5,6,7,8,9,10,11,1 2 or is characterized in the use of the image reading apparatus 13.

In the image reading apparatus according to any one of claims 1 to 14, the moving unit including the irradiating unit and the light receiving unit includes the entire configuration of the illumination unit, the imaging unit, the illumination light guide unit, and the entire configuration of the read light guide unit. Wherever the moving unit moves, the length of the illumination optical path and the length of the reading optical path can be kept constant. In addition, since the illumination light guide means for forming the illumination optical path and the read light guide means for forming the read optical path can be housed together in the moving unit, the length of the illumination optical path and the length of the read optical path can be kept constant. The second unit is unnecessary, and the moving body in the image reading apparatus is only the moving unit.

According to the first to fourteenth aspects of the present invention, the length of the illumination optical path and the length of the reading optical path can be kept constant, so that the image reading performance can be maintained, and the moving body in the apparatus is only a moving unit. By doing so, the space for moving the moving body and the space for moving the moving body need only be one moving body, so that the space for the moving body can be saved and the apparatus main body can be reduced in size. There is an excellent effect of being able to.

Embodiments in which the present invention is applied to a tandem type color image forming apparatus will be described below.
FIG. 2 is a schematic configuration diagram of a copying machine as an image forming apparatus according to the embodiment. The copying machine includes a copying apparatus main body (hereinafter referred to as a printer unit 100) and a paper feed table (hereinafter referred to as a paper feed unit 200). Further, an image reading device 300 that is a scanner unit attached to the upper part of the printer unit 100 and an automatic document feeder (ADF) (hereinafter referred to as a document conveying unit 400) attached to the upper part of the image reading device 300 are provided. A control unit (not shown) for controlling the operation of each device in the copying machine is also provided.

  The printer unit 100 includes an intermediate transfer belt 10 as an intermediate transfer member at the center thereof. The intermediate transfer belt 10 is wound around the first support roller 14, the second support roller 15, and the third support roller 16, and can move on the surface in the clockwise direction in the drawing. Then, four photosensitive drums 40K, 40Y, 40M as latent image carriers, each carrying a toner image of one of black, yellow, magenta, and cyan on the surface so as to face the intermediate transfer belt 10, are provided. 40C is provided. Developing units 61K, 61Y, 61M, and 61C for forming toner images on the surfaces of the four photosensitive drums 40K, 40Y, 40M, and 40C are provided. Further, photoconductor cleaning devices 63K, 63Y, 63M, and 63C for removing toner remaining on the surfaces of the photoconductor drums 40K, 40Y, 40M, and 40C after the primary transfer are also provided. Four image forming units 18K, 18Y, 18M, 18C including four photosensitive drums 40K, 40Y, 40M, 40C, developing units 61K, 61Y, 61M, 61C, and photosensitive member cleaning devices 63K, 63Y, 63M, 63C. Are arranged side by side to constitute the tandem image forming unit 20. Further, belt cleaning for removing residual toner remaining on the intermediate transfer belt 10 after the toner image is transferred onto a transfer sheet as a recording body so as to face the third support roller 16 with the intermediate transfer belt 10 interposed therebetween. A device 17 is provided. In addition, the printer unit 100 includes an exposure device 21 above the tandem image forming unit 20.

  Further, primary transfer rollers 62K, 62Y, 62M, and 62C are provided at positions inside the intermediate transfer belt 10 that face the photosensitive drums 40K, 40Y, 40M, and 40C with the intermediate transfer belt 10 interposed therebetween. The primary transfer rollers 62K, 62Y, 62M, and 62C are provided by being pressed against the photosensitive drums 40K, 40Y, 40M, and 40C with the intermediate transfer belt 10 interposed therebetween, thereby forming a primary transfer portion.

  On the other hand, a secondary transfer device is provided on the opposite side of the intermediate transfer belt 10 from the tandem image forming unit 20. This secondary transfer device is configured by a secondary transfer belt 24 being stretched between a secondary transfer roller 22 and a secondary transfer belt stretching roller 23. In the secondary transfer device, the secondary transfer belt 24 is pressed against the third support roller 16 via the intermediate transfer belt 10 at a position supported by the secondary transfer roller 22, and the secondary transfer belt 24 and the intermediate transfer belt 10. And a secondary transfer nip portion as a secondary transfer portion.

  A fixing device 25 for fixing the transfer image on the transfer paper is provided on the left side of the secondary transfer device. The fixing device 25 is configured by pressing a pressure roller 27 against a fixing belt 26 that is an endless belt. Further, the above-described secondary transfer device is also provided with a transfer paper transport function for transporting the transfer paper that has received the transfer of the toner image to the fixing device 25 at the secondary transfer nip portion. Note that a transfer roller or a non-contact charger may be disposed as the secondary transfer device. In such a case, it is difficult to provide this transfer paper conveyance function together.

  Under the secondary transfer device and the fixing device 25, a transfer paper reversing device 28 for reversing the transfer paper so as to record an image on both sides of the transfer paper is provided in parallel with the tandem image forming unit 20 described above. As a result, after the image is fixed on one side of the transfer paper, the transfer paper path is switched to the transfer paper reversing device side with the switching claw, and the transfer paper is transferred again to the secondary transfer nip portion to transfer the toner image. After that, the paper can be discharged onto a paper discharge tray.

  The image reading device 300, which will be described in detail later, reads image information of a document placed on the contact glass 6 with the imaging device 2, and sends the read image information to the control unit.

  A control unit (not shown) controls laser (not shown) and LEDs arranged in the exposure device 21 of the printer unit 100 based on the image information received from the image reading device 300, and writes laser light toward the photosensitive drum. Irradiate light L. By this irradiation, an electrostatic latent image is formed on the surface of the photosensitive drum 40, and this latent image is developed into a toner image via a predetermined development process.

  The paper feed unit 200 includes a paper cassette 43 provided in multiple stages in the paper bank 43, a paper feed roller 42 that feeds transfer paper from the paper feed cassette, a separation roller 45 that separates the fed transfer paper and sends it to a paper feed path 46, a printer A conveyance roller 47 for conveying the transfer paper is provided in the paper feed path 48 of the unit.

  In the copying machine according to the present embodiment, in addition to the paper feed unit 200, manual paper feed is also possible. The manual feed tray 51 for manual feed and the transfer paper on the manual tray 51 are directed toward the manual paper feed path 53. A separation roller 52 for separating the sheets one by one is also provided on the side of the apparatus.

  The registration roller 49 discharges only one sheet of transfer paper placed on the paper feed cassette 44 or the manual feed tray 51, and is positioned between the intermediate transfer belt 10 as an intermediate transfer member and the secondary transfer device. Send to the next transfer nip.

In the copying machine according to the present embodiment, when copying a color image, an original is set on the original tray 401 of the original conveying unit 400, or the original conveying unit 400 is opened and placed on the contact glass 6 of the image reading apparatus 300. The original can be pressed by setting the original and closing the original conveying section 400.
When a start switch (not shown) is pressed, the original is conveyed onto the contact glass 6 when the original is set on the original conveying section 400, and immediately after the original is set on the other contact glass 6, the image is immediately displayed. The reading device 300 is driven to read the image information of the document.

When the image information is received from the image reading device, a laser image as described above or a development process described later is performed to form a toner image on the photosensitive drum, and a transfer paper having a size corresponding to the image information is formed. In order to feed paper, one of the four paper feed rollers is operated.
Along with this, one of the first support roller 14, the second support roller 15 and the third support roller 16 is rotationally driven by a drive motor (not shown), and the other two support rollers are driven to rotate. The intermediate transfer belt 10 is rotated and conveyed. At the same time, the photosensitive drums 40 are rotated by the individual image forming units 18 to form monochrome images of black, yellow, magenta, and cyan on the photosensitive drums 40, respectively. Then, along with the conveyance of the intermediate transfer belt 10, the monochrome images are sequentially transferred to form a composite color image on the intermediate transfer belt 10.
On the other hand, in the paper feed unit 200, one of the paper feed rollers 42 is selectively rotated, the transfer paper is fed out from one of the paper feed cassettes 44, separated one by one by the separation roller 45, and put into the paper feed path 46 for conveyance. The roller 47 leads to a paper feed path 48 in the printer unit 100 which is a copying machine main body, and the transfer paper is abutted against the registration roller 49 and stopped. Alternatively, the transfer paper on the manual feed tray 51 is fed out by rotating the paper feed roller 50, separated one by one by the separation roller 52, put into the manual paper feed path 53, and abutted against the registration roller 49 and stopped. When the transfer paper on the manual feed tray 51 is used, the paper feed roller 50 is rotated to feed out the sheets on the manual feed tray 51, separated one by one by the separation roller 52, and put into the manual feed path 53. Stop against the registration roller 49.
Then, the registration roller 49 is rotated in synchronization with the composite color image on the intermediate transfer belt 10, and the transfer paper is sent to the secondary transfer nip portion where the intermediate transfer belt and the secondary transfer roller 22 are in contact with each other. The color image is secondarily transferred by the influence of the transfer electric field and contact pressure formed in the nip, and the color image is recorded on the transfer paper.

After the transfer of the color image at the secondary transfer nip portion, the transfer paper is sent to the fixing device 25 by the secondary transfer belt 24 of the secondary transfer device, and the pressure roller 27 and the fixing belt are fixed by the fixing device 25. The color image is fixed by applying pressure and applying heat. Thereafter, the paper is discharged by a discharge roller 56 and stacked on a paper discharge tray 57. Further, after the color image is fixed, the transfer paper on which images are formed on both sides is switched by the switching claw 55 and conveyed to the transfer paper reversing device 28, where it is reversed and led again to the secondary transfer nip portion, After the image is also recorded on the back surface, the paper is discharged onto a paper discharge tray 57 by a discharge roller 56.
On the other hand, the residual toner remaining on the surface of the intermediate transfer belt 10 after the color image is transferred onto the transfer paper at the secondary transfer nip portion is removed by the belt cleaning device 17, so that the tandem image forming unit 20 can form an image again. Prepare.

FIG. 1 is an explanatory perspective view of an image reading apparatus 300 according to the present embodiment.
As shown in FIG. 1, an image reading apparatus 300 includes an illuminating device 1 that is an illuminating unit, an imaging device 2 that is an imaging unit, an entire configuration of an illumination light guiding unit, and an entire configuration of a reading light guiding unit in a housing 4. A mirror box 30 is provided. The mirror box 30 provided with the illumination light guide means is a document original placed on the contact glass 6 from the image reading section 31 formed on the upper surface of the illumination light emitted from the illumination section of the illumination light guide means. Irradiate toward the surface. Also, in the lens barrel 30 provided with the reading light guiding means, the reading light reflected from the document surface enters from the image reading section 31 and is received by the light receiving section of the reading light guiding means.

The contact glass 6 is a transparent glass, which is also referred to as a document table, on which a document such as a sheet or a book is placed so that the document surface with the document image faces downward. The mirror box 30 stores a plurality of mirror surfaces for bending the illumination light from the illuminating device 1 into a reading region by bending the illumination light, and guiding the image light in the reading region into the reading unit by bending the image light.
The illuminating device 1 emits illuminating light, and the illuminating light emitted from the illuminating device 1 is guided by a lens box 30 having an illuminating light guiding means and travels from the irradiating unit to the document surface through the image reading unit 31. Is irradiated.
The imaging device 2 receives and captures reading light reflected from the original surface by illumination light, and includes an imaging lens 201 and a CCD 202. The reading light reflected from the original surface is incident on the light receiving portion of the reading light guiding means in the mirror case 30 from the image reading portion 31, guided by the mirror case 30, and incident on the imaging lens 201 of the imaging device 2. The imaging lens 201 is generally configured by integrating a plurality of lenses with a lens barrel, and forms an image of a document in a region where the reading light is reflected on the CCD 202. Then, the CCD 202 converts document image image light in an area where the reading light obtained through the imaging lens 201 is reflected into an electric signal.

  The illumination light emitted from the illuminating device 1 has directivity in the irradiation direction, the light amount is concentrated within a predetermined width in the sub-scanning direction (arrow B direction in the figure), which is a specific direction on the document surface, and the seed scanning direction (in the figure). The arrow C direction) is incident on the entire reading region S on the contact glass 6 in the main scanning direction. The illuminating device 1 mentioned later for details is equipped with LED as a light source which emits directional illumination light. Further, an illumination light splitting unit that splits the illumination light into a plurality of split lights in the main scanning direction, and a split light guide that guides the split lights so that respective illumination areas of the plurality of split light on the document surface overlap on the document surface. And various lens members constituting the means. With such an illuminating device 1, variation in the main scanning direction of the amount of illumination light incident on the document surface can be suppressed, and good image reading can be performed.

  The CCD 202 provided in the imaging device 2 is a one-dimensional imaging device capable of imaging the entire region in the main scanning direction, and the illumination light from the illumination device 1 illuminates the entire region in the main scanning direction of the document surface, whereby the document image in the main scanning direction. Image information for the entire area can be acquired. Then, by moving the image reading unit 31 in the sub-scanning direction indicated by the arrow B in FIG. 1, the document image is scanned in the sub-scanning direction to acquire image information. Thereby, the document image can be read two-dimensionally.

Next, the characteristic part of this embodiment is demonstrated.
As shown in FIG. 1, the image reading apparatus 300 according to the present embodiment includes a moving unit 3 that integrates the illumination device 1, the imaging device 2, and the mirror case 30. The moving unit 3 is movable in the sub-scanning direction in parallel with the contact glass 6. By moving the moving unit 3 including the mirror box 30 in the sub-scanning direction, the image reading unit 31 formed on the upper surface of the mirror box 30 can be moved in the sub-scanning direction, and the original image is scanned in the sub-scanning direction. can do.
In this image reading apparatus 300, since the mirror case 30 including the illumination light guiding means and the illumination apparatus 1 are integrated, the length of the illumination optical path can be kept constant, so that the illuminance in the main scanning direction on the document surface It is possible to prevent the occurrence of variations. On the other hand, since the lens box 30 provided with the reading light guiding means and the imaging device 2 are integrated, the length of the reading light path can be kept constant, so that the reading light is favorably imaged on the surface of the CCD 202. Can do. Thus, the length of the illumination optical path and the length of the reading optical path can be kept constant, so that the image reading performance can be maintained.
In addition, since the lens box 30 including the illumination light guide means for forming the illumination light path and the read light guide means for forming the read light path can be housed in one moving body as the moving unit 3, the length of the illumination light path and the reading The second unit for keeping the length of the optical path constant becomes unnecessary, and the moving body of the housing 4 is only the moving unit 3. Since the mobile unit 3 is the only mobile unit that moves in the housing 4, the space in which the mobile unit is arranged and the space in which the mobile unit moves are only one mobile unit, ie, the mobile unit 3. Thus, the space of the image reading apparatus 300 can be reduced.
The above-described entire reading area S on the contact glass 6 is determined by the reading range in the main scanning direction of the CCD 202 which is a one-dimensional imaging device and the range in which the image reading unit 31 moves as the moving unit 3 moves. .

Next, the lighting device 1 will be described.
FIG. 3 is an explanatory diagram of the lighting device 1. FIG. 3 (a) is a top explanatory view viewed from the contact glass 6 side when mounted on the image reading apparatus 300. FIG. 3B is a front explanatory view seen from the front side (front side in FIG. 2) of the copying machine when the image reading apparatus 300 is attached to the copying machine as shown in FIG.

As shown in FIG. 3, the illumination device 1 includes a light source 101 arranged in a straight line in the main scanning direction, and includes a condenser lens 102, an illumination lens 103, and an integrated lens 104 in the irradiation direction of illumination light emitted from the light source 101. Prepare. As shown in FIG. 3, the distance from the integrated lens 104 to the illumination target surface F is a, the distance from the illumination lens 103 to the integrated lens 104 is b, the distance from the condenser lens 102 to the illumination lens 103 is c, The distance from the light source 101 to the condenser lens 102 is d.
The light source 101 includes an LED 101a and a rotary parabolic mirror 101b. By placing the LED 101a at the focal position of the rotary parabolic mirror 101b and reflecting the illumination light emitted by the LED 101a, the illumination light emitted from the light source 101 is irradiated as directional parallel light. However, since the light emitting surface of the LED 101a is not completely a point but has a certain area, it deviates from parallel light as it deviates from other than the focal position of the rotary parabolic mirror 101b. A representative example of the light distribution characteristic is shown in FIG.

  The condensing lens 102 which is a focusing lens group is a lens for efficiently causing the illumination light including not only parallel light but also divergent light to enter the illumination lens 103. The shape is a cylinder lens array having a shape as shown in FIG. 5A, and a plurality of cylinder lenses are arranged. The condensing lens 102 has a condensing cylinder lens 102a, which is a plurality of converging lenses, arranged in a straight line in the main scanning direction. When the illumination light is incident, the illumination light is converged on the respective focal points of the respective condensing cylinder lenses 102a to divide the illumination light in the main scanning direction to obtain the same number of divided lights as the number of cylinders. Each split light is incident on the illumination lens 103. The focal length of the condenser cylinder lens 102a is the distance from the condenser lens 102 to the illumination lens 103. That is, if the focal length of the condensing cylinder lens 102a is f1, f1 = c.

  The illumination lens 103, which is a diverging lens group, becomes substantially parallel light by the rotary parabolic mirror 101b, and divides each divided light focused by the condenser lens 102 in the main scanning direction to illuminate the illumination target surface F. This is a cylinder array lens. The shape is a cylinder lens array having a shape as shown in FIG. 5A, like the condenser lens 102, and a plurality of cylinder lenses are arranged. In the illumination lens 103, illumination cylinder lenses 103a, which are the same number of diverging lenses as the condensing cylinder lenses 102a, are arranged in a straight line in the main scanning direction, and the divided light beams divided by the condensing cylinder lenses 102a are separated by the illumination cylinder lenses 103a. The illumination target surface F is illuminated by diverging. Assuming that the focal length of the condensing cylinder lens 102a is f2, approximately f2 = 1 / (1 / (a + b) + 1 / c).

In the illuminating device 1, the condenser lens 102 and the illuminating lens 103 constitute an illuminating light dividing unit.
It is possible to design f1 = f2, so that the condenser lens 102 and the illumination lens 103 can be used as members of the same standard. If the condensing lens 102 and the illumination lens 103 are made the same, the management burden such as during manufacturing, sales, and service is reduced.

The integrated lens 104 is a lens for superimposing the illumination areas on the illumination target surface F of the divided light divided by the condenser lens 102 and the illumination lens 103. Specifically, this is a lens that refracts light so that the optical axis of the incident light is directed to a predetermined position on the illumination target surface F, regardless of the position on the light receiving surface. All the divided lights that have passed through each illumination cylinder lens 103a are arranged so as to enter the light receiving surface. The predetermined position of the illumination target surface F described above is a position where the main optical axis Lm, which is the optical axis of the entire illumination light emitted from the illumination device 1, intersects the illumination target surface F.
If the focal length of the integrated lens 104 is f0, then f0 = a. With this setting, the intersection between the optical axis (referred to as the sub optical axis Ls) of each split light divided by the condenser lens 102 and the illumination lens 103 and the illumination target plane F is defined as the illumination target plane F and the main optical axis Lm. Can be matched to the intersection of Thereby, the illumination area | region in the illumination object surface F of all the divided lights can be overlapped.
As described above, the integrated lens 104 has a function as a divided light guiding unit that guides the divided light so that the illumination areas of the plurality of divided lights on the illumination target surface F overlap on the illumination target surface F.

Further, as the shape of the integrated lens 104 in the main scanning direction, a general lens having the main optical axis Lm as an axis object can be used. Further, as shown in FIG. 3B, the integrated lens 104 is unnecessary for the width in the vertical direction in FIG. 3B, which is the width in the direction corresponding to the sub-scanning direction in the width direction of the illumination light. The shape is a cut part. That is, the shape of the integrated lens 104 is obtained by cutting an unnecessary portion in the vertical direction of a general circular convex lens.
Note that in the image reading apparatus 300 of the present embodiment, the illumination light irradiation direction is substantially the sub-scanning direction when the illumination apparatus 1 emits light, but the details provided in the mirror case 30 will be described later by the illumination light guide means described later. When incident on the light, the vertical direction is obtained. Therefore, the direction in the vicinity of the illuminating device 1 corresponding to the direction of the sub-scanning direction when entering the document surface with respect to the width of the illumination light is the vertical direction.

  When the width of the condensing cylinder lens 102a in the main scanning direction is m1, and the width of the illumination area on the illumination target surface F is m0, m1 / m0 = c / a. In the actual machine, f0 and f1 are set after determining the relationship of m1 / m0 = c / a. With this setting, an image having a width m1 in the main scanning direction of the condensing cylinder lens 102a is projected on the illumination target surface F to a size of m0, and the divided light that was m1 in the main scanning direction is reflected on the illumination target surface F. The entire width of the illumination area in the main scanning direction can be illuminated.

  As the condensing lens 102 and the illuminating lens 103 which are the illumination light dividing means, it is desirable that the number of the light sources 101 and the number of the condensing cylinder lenses 102a are not matched. By comprising in this way, the influence of the profile formed with LED101a and the rotary parabolic mirror 101b can be reduced, and the variation in the illumination intensity in an illumination object surface can be suppressed. In addition, when it is set as the number of the condensing cylinder lenses 102a exceeding twice the number of the light sources 101, it may be an integer multiple.

As shown in FIG. 3, in the configuration in which the number of condensing cylinder lenses 102a does not match the number of light sources 101 and is not an integral multiple of the number of light sources 101, light sources 101 that emit illumination light of the same color are arranged in the main scanning direction. Applies to what you do. This is because, when illumination lights of a plurality of colors are incident on one condenser cylinder lens 102a, color unevenness may occur in illumination on the illumination target surface F. If the number of condensing cylinder lenses 102a is an integral multiple of the number of light sources 101, the light sources 101 that emit illumination light of different colors in the main scanning direction can be arranged.
As a configuration in which the light source 101 that emits illumination light of different colors in the main scanning direction is arranged, three colors of R (red), G (green), and B (blue) are used as a light emitting diode as the LED 101a. At this time, it is sufficient that at least three light sources 101 are provided for each color, and it is also possible to increase only the light sources 101 having a small amount of emitted light in consideration of the color balance even with an integral multiple thereof. The number of condensing cylinder lenses 102a is an integral multiple of the number of light sources 101, and a single condensing cylinder lens 102a is arranged so that one color of illumination light is incident thereon, whereby the light source 101 of a plurality of colors is subjected to main scanning. Can be arranged side by side in the direction.
Note that the light source 101 of a plurality of colors can be arranged side by side in the main scanning direction as long as the illumination light of one color is incident on one condensing cylinder lens 102a without being limited to an integral multiple.

Next, using the front explanatory view shown in FIG. 3B, the vertical direction in the illumination device 1 and the sub-scanning direction on the document surface corresponding to the vertical direction in the illumination device 1 with respect to the width of the illumination light (in the drawing) The state of illumination light in the direction of arrow B will be described.
Until the LED 101a emits light and exits the rotating parabolic mirror 101b, it behaves in the same manner as in the top view of FIG. That is, the illumination light emitted from the light source 101 is parallel light. Since the condenser lens 102 and the illumination lens 103 are only parallel plates perpendicular to the main optical axis Lm when viewed from the front, the illumination light incident on the condenser lens 102 and the illumination lens 103 passes through as parallel light. . Since the focal length of the integrated lens 104 is f0 = a, the illumination light that has entered the integrated lens 104 as parallel light is focused on the illumination target surface F so as to be focused. In this way, the illumination light emitted from the LED 101a of the light source 101 is collected in a straight line in the main scanning direction on the illumination target surface F without waste, and high-quality illumination can be performed with little uneven illuminance.
The integrated lens 104 only needs to pass through a region where the amount of illumination light is concentrated due to the directivity of the illumination light. Therefore, as described above, the integrated lens 104 does not remain circular but is cut by unnecessary upper and lower portions. Can be very thin.

However, as described above, since the LED 101a is not completely a point, the illumination light emitted from the rotary parabolic mirror 101b includes divergent light. In the configuration shown in FIG. 3B, the divergent light deviates from the focal position and enters the illumination target surface. The illuminance distribution is similar to the orientation distribution of FIG. 3, and considering the orientation distribution half-value width, it can be considered that, for example, a width such as M ′ in FIG.
Another way of thinking is that if the size of the LED 101a which is a light emitter having an area is f3, the ratio of f3 and the focal length f0 of the integrated lens 104 is (f0) / ( f3) It can be said that the image is magnified by a factor of 2 and an image is formed on the illumination target surface F. Here, f0 = a, and the ratio between f0 and f3 increases from several tens to one hundred times, so that the image of the LED 101a chip with several millimeters of zero points is projected to a size of several centimeters. As a result, it can be seen that the illumination light width can be obtained only in the order of several tenths to one hundredth only in the direction of the sub-scanning direction on the document surface.

FIG.3 (c) is front explanatory drawing of the 1st example of the illuminating device 1 which can irradiate illumination light to an illumination object surface more efficiently compared with the structure of FIG.3 (b).
In the illumination device 1 of FIG. 3C, the integrated lens 104 is changed to a cylinder lens. The main scanning direction has the same curvature so as to have the same focal length as the integrated lens 104 having the configuration described with reference to FIGS. 3 (a) and 3 (b). On the other hand, the sub-scanning direction is straight.
In the configuration of FIG. 3C, the sub-scanning direction focusing lens 105 is provided on the illumination optical path that is separated from the illumination device 1. The sub-scanning direction converging lens 105 is a cylinder lens in which the condensing function in the sub-scanning direction is separated from the integrated lens 104 in FIG. When the distance between the sub-scanning direction focusing lens 105 and the illumination target surface F is a ′ and the focal length of the sub-scanning direction focusing lens 105 is f4, they are arranged so that f4 = a ′. The sub-scanning direction focusing lens 105 has a shape as shown in FIG.
In this way, the illumination light emitted from the rotary parabolic mirror 101b reaches the sub-scanning direction converging lens 105 while remaining substantially parallel light (including divergent light). The magnification of the image of the LED 101a chip described above is a ′ / f3, which is suppressed to several times. Thereby, the efficiency of illumination light is improved by an order of magnitude.

FIG.3 (d) is front explanatory drawing of the 2nd example of the illuminating device 1 which can irradiate illumination light to an illumination object surface more efficiently compared with the structure of FIG.3 (b). The illuminating device 1 in FIG. 3D includes a second focusing lens 106 in the sub-scanning direction in addition to the configuration described with reference to FIG. The sub-scanning direction second focusing lens 106 is a cylinder lens having a relationship such that the image of the LED 101 a is formed at the position of the sub-scanning direction focusing lens 105. That is, when the focal length of the second focusing lens 106 in the sub-scanning direction is f5, f5 = 1 / (1 / a ″) + (1 / b ″). Note that a ″ is the distance from the sub-scanning direction second focusing lens 106 to the sub-scanning direction focusing lens 105, and b ″ is the distance from the LED light source 101 to the sub-scanning direction focusing lens 105. The sub-scanning direction second focusing lens 106 has a shape as shown in FIG.
In this case, it is effective that the focal length f5 of the sub-scanning direction focusing lens 105 is f5 = 1 / (1 / a ′) + (1 / a ″). However, even if f5 = a ″ is maintained. Although the efficiency is slightly lowered, the efficiency is improved as compared with the configuration of FIG.
As a result of experiments conducted by the present inventors, the configuration shown in FIG. 3D was found to improve efficiency by about 50% compared to the configuration shown in FIG.
In FIG. 3 (a), the sub-scanning direction second focusing lens 106 and the sub-scanning direction focusing lens 105 are indicated by a two-dot chain line, but the configuration including both is shown in FIG. 3 (d). Configuration only.

In the illuminating device 1 shown in FIG. 3, the illuminance distribution in the sub-scanning direction of the reading area reflects the light distribution characteristics of FIG. 4, so that when obtaining a black and white image, the center of the CCD 202 may be aligned with the peak. However, when a three-line CCD is used to obtain a color image, when one color is matched to the peak as shown in FIG. 6A, the other two colors read the places where the amount of light has dropped.
This difference in the amount of light can be corrected by changing the amplification factor electrically after being read by the CCD, but it is more effective to optically suppress the difference in the amount of light, and the illumination efficiency is also improved.

FIG. 7 shows a configuration in which the illuminating device 1 having the configuration shown in FIG. 3D is arranged in three rows in the direction corresponding to the sub-scanning direction (up and down direction in the device) with respect to the illumination light. FIG. 7A is a top explanatory view, and FIG. 7B is a front explanatory view. As shown in FIG. 7A, the main optical axis Lm, which is the optical axis in the main scanning direction of the illumination light on the illumination target surface, is shifted from the optical axis of the reading system, and competition with the imaging lens 201 in that direction occurs. The structure is shown to avoid it.
The CCD 202 that reads an image for each color of R, G, and B and converts it into an electrical signal is arranged in three rows in the direction corresponding to the sub-scanning direction (up and down direction in the apparatus) with respect to the reading light. FIG. 7B shows a configuration in which the reading area is illuminated corresponding to each color.
As shown in FIG. 7B, the light sources 101 having LEDs for each of the three colors are arranged in a direction corresponding to the sub-scanning direction (up and down direction in the apparatus) for the illumination light. The illumination device 1 shown in FIG. 7 includes a sub-scanning direction illumination lens 107 and a sub-scanning direction integration lens 108. The integrated lens 104 shown in FIG. 7 has a shape as shown in FIG.

The sub-scanning direction illumination lens 107 is a cylinder lens array in which three cylinder lenses are arranged, and f6 = b ″ where one focal length of the cylinder lens is f6.
The sub-scanning direction integration lens 108 is a cylinder lens that aligns the optical axis of each illumination light emitted from each cylinder lens of the sub-scanning direction illumination lens 107 on the sub-scanning direction focusing lens 105. If the focal length of the sub-scanning direction integration lens 108 is f7, then f7 = a ″.
The combined focal length of the sub-scanning direction illumination lens 107 and the sub-scanning direction integration lens 108 is C = 1 / (1 / a ") in FIG. 2d) of the focal length f5 of the sub-scanning direction second focusing lens 106 described above. It becomes the same value as + (1 / b "). Note that b ′ is small enough to be ignored.

  With this configuration, in the illuminance distribution in the sub-scanning direction of the reading area, the peak of the illuminance distribution for each color of R, G, and B can be shifted as shown in FIG. It is most efficient to match with the position of the 3-line CCD.

8 includes a first illuminating device 1a and a second illuminating device 1b, and the two illuminating devices 1 are connected to the main optical axis Lm on the document surface, which is the illumination target surface of the illuminating light emitted, and the imaging device 2. It is explanatory drawing at the time of making the reading optical axis Lr of the incident reading light correspond in both the main scanning direction and the sub-scanning direction.
As shown in FIG. 8A, when the first illumination device 1a and the second illumination device 1b both illuminate the entire area of the document surface in the main scanning direction, the regular reflection light Ld on the surface of the contact glass 6 is directly emitted. The white streaks are superimposed on the read image after entering the imaging lens 201. In the case of this method, white streaks appear as many as the number of light sources 101.
On the other hand, FIG. 8B is an explanatory diagram of a configuration that prevents the regular reflection light Ld from gathering on the imaging lens 201 while keeping the optical axes of the illumination light and the reading light in the sub-scanning direction coincident with each other. It is. In the configuration of FIG. 8B, the main optical axis of each illuminating device 1 is adjusted to the position of ¼ of the reading area on the opposite side across the reading optical axis Lr. In FIG. 8B, the first main optical axis Lm1 of the illumination light of the first illumination device 1a is ¼ of the full width in the main scanning direction from the reading optical axis Lr of the reading area on the opposite side across the reading optical axis Lr. Intersects the original surface, which is the surface to be illuminated. The document surface which is the illumination target surface at the position where the second main optical axis Lm2 of the illumination light of the second illumination device 1b is ¼ of the full width in the main scanning direction from the reading optical axis Lr on the opposite side across the reading optical axis Lr Interact with. In this case, since the area illuminated by one illumination device 1 is half of the entire area, it is essential to use two illumination devices 1. In this way, regular reflection light from any light source 101 does not enter the imaging lens 201.
In addition, 104a in FIG.8 (b) has shown the cut part of the integrated lens 104 with which the 1st illuminating device 1a is provided, and 104b has shown the cut part of the integrated lens 104 with which the 2nd illuminating device 1b is provided.

Next, details of the necessary range of each mirror provided in the interior of the mirror case 30 described later will be described.
Since the length of the optical path from the document surface to the imaging device 2 or from the illumination device 1 to the document surface needs to be several tens of centimeters, in order to make the moving unit 3 compact, the optical path is formed by a plurality of mirrors. Need to wrap. In that case, the width required for the mirror depends on the position.
FIG. 9 is an explanatory diagram of the width required for a mirror that varies depending on the position of the mirror. FIG. 9A is an explanatory diagram of the reading optical path, and FIG. 9B is an explanatory diagram of the illumination optical path.
Since the size of the reading area A in the sub-scanning direction is several tens of microns, in this case, as shown in FIG. 9A, it can be ignored and viewed as a triangle similar shape with the opening 201d of the imaging lens 201 as the base. It ’s easy. Regarding the reading light, the width of the mirror corresponding to the sub-scanning direction on the document surface may be narrower closer to the document surface, but the width is required as it approaches the imaging lens 201.
As for the illumination optical path, as shown in FIG. 9B, a portion that diverges at the divergence angle θL is added to the opening L of the illumination device 1. This is opposite to the reading optical path and may be narrower near the illumination device 1, but the sub-scanning direction converging lens 105 requires a width as it approaches the document surface. However, this is not the case unless the illumination light is used efficiently.

Next, a configuration for reducing the weight of the integrated lens 104 will be described.
The integrated lens 104 in which many light sources 101 are arranged in the main scanning direction becomes large. Actually, there is no problem in optically extending to the width of the apparatus, but as the width is increased, the thickness (in the main optical axis direction) increases and the weight increases. Therefore, the integrated lens 104 is formed into a Fresnel lens as shown in FIG. By doing so, an increase in weight can be suppressed, so that inertia can be suppressed when mounted on the moving unit 3 and moved, and speeding up is not hindered. When the cylinder lens shown in FIG. 5C is made into a Fresnel lens, the range of the region α in FIG. 10 is used.

[Example 1]
Next, a first example (hereinafter referred to as Example 1) of a specific configuration of the mobile unit 3 of the present embodiment will be described.
FIG. 11 is an explanatory front view of the moving unit 3 according to the first embodiment.
As shown in FIG. 11, the moving unit 3 includes a lighting device 1, an imaging device 2, and a lens box 30 as a single unit. The mirror case 30 includes three mirror members, a first turning mirror M1, a second turning mirror M2, and a third turning mirror M3. These three mirror members are the illumination light guide means and the reading light guide. Means. The first turning mirror M1 is an irradiation unit that irradiates illumination light toward the document surface, and a light receiving unit that receives reading light that is reflected light from the document. Note that the moving unit 3 is movable in the sub-scanning direction indicated by an arrow B in FIG. The illumination device 1 provided in the moving unit 3 of FIG. 11 includes a parabolic mirror or an ellipsoidal mirror (from here on as a focusing mirror) in the configuration of the lighting device 1 described with reference to FIG. The first deflecting mirror M1 has a function as a condensing means.
Further, the first turning mirror M1 forms the plane mirror part 204 as a non-condensing part only in a range required by the optical path of the reading light with the optical axis of the focusing mirror as the center. This is for avoiding distortion of the read image on a paraboloid or ellipsoid.

The illumination light from the illuminating device 1 is reflected in the order of the third turning mirror M3, the second turning mirror M2, and the first turning mirror M1 from the image reading unit 31 to the reading area A on the document surface. Incident. The illumination light is converged by being reflected by the paraboloid of the first turning mirror M1 and converged in the reading area A. An optical axis in a direction corresponding to the sub-scanning direction of the illumination light is defined as an illumination optical axis Li.
The reading light reflected by the reading area A is reflected along the reading optical axis Lr in the order of the plane mirror unit 204 of the first turning mirror M1, the second turning mirror M2, and the third turning mirror M3. The light enters the imaging lens 201 of the imaging device 2. The reading light that has entered the imaging lens 201 forms an image on the CCD 202 and is imaged.
In the configuration of the first embodiment, the regular reflection light of the illumination optical axis Li coincides with the reading optical axis on a plane orthogonal to the main scanning direction as shown in FIG. 11, so the configuration shown in FIG. desirable.

As shown in FIG. 11, the lens box 30 includes a second turning mirror M2 and a third turning mirror M3 as two mirror surfaces facing each other. The illumination light reciprocates between the second turning mirror M2 and the third turning mirror M3 until the illumination optical axis Li reaches the reading area A on the document surface from the illumination device 1. Thus, the illumination optical path is formed. In this way, by forming the illumination optical path so that the illumination optical axis reciprocates at least once between the two mirror surfaces, the moving unit 3 having the illumination light guiding means can be reduced in size while ensuring the length of the illumination optical path. Can be planned.
Also, the illumination light reciprocates at least once between the second turning mirror M2 and the third turning mirror M3 until the reading optical axis Lr reaches the imaging device 2 from the reading area A on the original surface. Thus, the reading optical path is formed. In this way, the reading optical path is formed so that the reading optical axis makes at least one reciprocation between the two mirror surfaces, thereby reducing the size of the moving unit 3 provided with the reading light guiding means while ensuring the length of the reading optical path. Can be planned.

  As another method for avoiding the distortion of the read image, the correction lens 203 (paraboloid) is formed immediately before the imaging lens 201 while leaving the parabolic surface 204 or the ellipsoidal surface without forming the plane mirror portion 204 in the first deflecting mirror M1. A function that is an inverse function of a surface or an elliptical surface) may be inserted. In FIG. 11, both the correction lens 203 and the plane mirror unit 204 are shown, but only one of them is provided.

[Example 2]
Next, a second example (hereinafter referred to as Example 2) of the specific configuration of the mobile unit 3 of the present embodiment will be described.
FIG. 12 is an explanatory front view of the moving unit 3 according to the second embodiment.
In the first embodiment, as shown in FIG. 11, the second turning mirror M2 and the third turning mirror M3 are arranged to be inclined, but in the second embodiment, instead, the illumination device 1 and the imaging device 2 are arranged. And are tilted. Further, the tilt angle between the illumination device 1 and the imaging device 2 is made to be inconsistent, and the focusing mirror 109 is provided as a separate member from the first turning mirror M1. The reading optical axis Lr is kept perpendicular to the plane of the contact glass 6, and the illumination optical axis Li is tilted to illuminate the reading area A.
In the second embodiment, the illumination light guiding means includes the second turning mirror M2, the third turning mirror M3, and the focusing mirror 109, and the reading light guiding means includes the second turning mirror M2 and the third turning mirror M3. And a first turning mirror M1. The irradiation unit is the focusing mirror 109, and the light receiving unit is the first turning mirror M1.
By making the inclination angles of the illumination device 1 and the imaging device 2 inconsistent, the illumination optical axis Li and the reading optical axis Lr do not coincide on a plane orthogonal to the main scanning direction as shown in FIG. As a result, the focusing mirror 109 constituting the illumination light guiding means is provided as a separate member from the first turning mirror M1 constituting the reading light guiding means, and a member having a condensing function from the member constituting the reading guide means. Can be excluded. This eliminates the need to form a non-condensing part on a member having a condensing function or to provide a correction lens 203 as a light-collecting distortion correcting unit in front of the integrated lens 104 in the reading optical path.
As in the second embodiment, the reading optical axis Lr is perpendicular to the plane of the contact glass 6 on a plane orthogonal to the main scanning direction, and the illumination optical axis Li is tilted, whereby the contact glass 6 with the illumination optical axis Li is tilted. The specularly reflected light Ld on the plane can also be inconsistent with the reading optical axis Lr. Thereby, it is possible to prevent the regular reflection light of the illumination light from entering the imaging lens.

Example 3
Next, a third example (hereinafter referred to as Example 3) of the specific configuration of the mobile unit 3 of the present embodiment will be described.
FIG. 13 is an explanatory front view of the moving unit 3 according to the third embodiment.
In the second embodiment, the illumination device 1 and the imaging device 2 are arranged at the same position on a plane orthogonal to the main scanning direction. However, in the third embodiment, the illumination device 1 and the imaging device 2 are arranged on the same plane. Arranged at different positions on the top. By arranging in this manner, the illumination optical axis Li and the reading optical axis Lr can be made inconsistent on a plane orthogonal to the main scanning direction, and the illumination apparatus 1 and the imaging apparatus 2 are in the sub-scanning direction. The main optical axis in the corresponding direction can be shifted. Therefore, it is possible to prevent the regular reflection light of the illumination light from entering the imaging lens.
In the third embodiment, the illumination light guiding means includes the second turning mirror M2, the third turning mirror M3, and the focusing mirror 109, and the reading light guiding means includes the second turning mirror M2 and the third turning mirror M3. And a first turning mirror M1. The irradiation unit is the focusing mirror 109, and the light receiving unit is the first turning mirror M1.
In the third embodiment, the second turning mirror M2 constituting the reading term guiding means is a reflecting mirror including the transmission part β. And it is set as the structure which has arrange | positioned the light emission position which the illuminating device 1 emits illumination light in the position facing the transmission part (beta) in the position facing the back side of the 2nd direction change mirror M2. The second turning mirror M2 is mirror-finished on one side of a transparent body such as glass, and the transmission part β through which the illumination light emitted from the illumination device 1 passes is not configured to be a mirror surface. Of course, the second turning mirror M2 may be divided into two.
As in the case of the second turning mirror M2 in FIG. 13, the reading light is reflected at two places on the same plane, and the light emitting position of the illumination device 1 is arranged between the two places. Even if a reflecting mirror is provided at each position where light is reflected, the reading light can be guided in the same manner as in the third embodiment. However, if a reflecting mirror is provided at each of two locations, it is necessary to align the reflecting mirror for adjusting the reflection angle for each of the reflecting mirrors provided at two locations. On the other hand, as shown in FIG. 13, the second deflecting mirror M2 is provided with a transmission part β so that the illumination light can pass therethrough, and the reading light is reflected above and below the transmission part β, thereby providing one reflection mirror. The reading light can be reflected at two locations across the light emission position. For this reason, the position of the reflecting mirror for adjusting the reflection angle at two locations above and below the light emission position can be adjusted by the position of one member, and the adjustment of the reflection angle becomes easy.

Example 4
Next, a fourth example (hereinafter referred to as Example 4) of the specific configuration of the mobile unit 3 of the present embodiment will be described.
FIG. 14 is an explanatory front view of the moving unit 3 according to the fourth embodiment.
In the fourth embodiment, the second deflecting mirror M2 according to the third embodiment divides the area that reflects the illumination light and the area that reflects the reading light, and sets the mirror surface of the area that reflects the illumination light as the fourth turning mirror. The configuration is M4. Then, the second turning mirror M2 is arranged in parallel with the third turning mirror M3, and the fourth turning mirror M4 is more tightly tilted than the third turning mirror M3 so as to return the reflection angle slightly (for example, By increasing the tilt amount by 1.5), the width of the second turning mirror M2 can be reduced while avoiding vignetting by the first turning mirror M1.
Furthermore, in the third embodiment, even if dust or dirt is attached to the second turning mirror M2 or the third turning mirror M3 to cause flare of illumination light, the flare light is less likely to enter the integrated lens 104.
In the fourth embodiment, the illumination light guiding means includes the third turning mirror M3, the fourth turning mirror M4, and the focusing mirror 109, and the reading light guiding means includes the second turning mirror M2 and the third turning mirror M3. And a first turning mirror M1. The irradiation unit is the focusing mirror 109, and the light receiving unit is the first turning mirror M1.

Example 5
Next, a fifth example (hereinafter referred to as Example 5) of the specific configuration of the mobile unit 3 of the present embodiment will be described.
FIG. 15 is an explanatory front view of the moving unit 3 according to the fifth embodiment.
The configuration of the fifth embodiment more actively separates the reading optical path and the illumination optical path than the configuration of the fourth embodiment. That is, each return space is made separate.
In the fifth embodiment, the illumination light guiding means includes the fourth turning mirror M4, the third turning mirror M3, the focusing mirror 109, and the fifth turning mirror M5, and the reading light guiding means is the second turning mirror M2. , Comprising a third turning mirror M3 and a first turning mirror M1. The irradiation unit is the fifth turning mirror M5, and the light receiving unit is the first turning mirror M1.
The imaging device 2 is arranged on the upper side of the mirror box 30, the second turning mirror M <b> 2 and the first turning mirror M <b> 1 are arranged on the left side of the mirror box 30, and the reading optical path is sandwiched between the image reading unit 31 in the mirror box 30. It is formed on the left side in the figure. On the other hand, the illuminating device 1 is arranged below the imaging device 2, the fourth turning mirror M4, the focusing mirror 109, and the fifth turning mirror M5 are arranged on the right side of the mirror case 30, and the illumination light path is arranged in the mirror case 30. It is formed on the right side in the figure with the image reading unit 31 in between. The illumination light from the illuminating device 1 passes below the area forming the reading optical path, reaches the area forming the illumination optical path, is reflected by each mirror, and enters the reading area A.
The positions of the focusing mirror 109 and the fifth turning mirror M5 may be changed. When the position is changed, the focal length of the focusing mirror 109, the size of the mirror, and the like are optimally designed according to the position.
The third turning mirror M3 is configured such that one surface of a transparent body such as glass is a mirror surface and the other is transparent. The side having the mirror-finished surface as the direct reflection surface is used for reflection of the reading system, and the side reflected through the transparent body from the opposite side is used for reflection of the illumination system. In this way, the mirror can be shared between the reading system and the illumination system without distorting the read image.

Example 6
Next, a sixth example (hereinafter referred to as Example 6) of the specific configuration of the mobile unit 3 of the present embodiment will be described.
FIG. 16 is an explanatory front view of the moving unit 3 according to the sixth embodiment.
The configuration of the sixth embodiment is a configuration in which the illumination device 1 having the configuration of the fifth embodiment is disposed above the imaging device 2.
In the sixth embodiment, the illumination light guiding means includes the fourth turning mirror M4, the third turning mirror M3, and the focusing mirror 109, and the reading light guiding means includes the second turning mirror M2 and the third turning mirror. It consists of M3 and the first turning mirror M1. The irradiation unit is the focusing mirror 109, and the light receiving unit is the first turning mirror M1.

Example 7
Next, a seventh example (hereinafter referred to as Example 7) of the specific configuration of the mobile unit 3 of the present embodiment will be described.
FIG. 17 is an explanatory front view of the moving unit 3 according to the seventh embodiment.
The seventh embodiment is an example in which the folding space of the reading system and the illumination system of the moving unit of the sixth embodiment is exchanged. In the seventh embodiment, the illumination light guiding means includes the fourth turning mirror M4, the fifth turning mirror M5, the third turning mirror M3, and the focusing mirror 109, and the reading light guiding means is the second turning mirror. M2, M2 ′, a third turning mirror M3, and a first turning mirror M1. The irradiation unit is the focusing mirror 109, and the light receiving unit is the first turning mirror M1.

  As the focusing mirror 109 provided in the second to seventh embodiments described above, a parabolic mirror or an ellipsoidal mirror having a shape as shown in FIG. 18 can be used.

As described above, according to the present embodiment, the moving unit 3 includes the illuminating device 1 that is the illuminating unit, the imaging device 2 that is the imaging unit, the entire configuration of the illumination light guiding unit, and the entire configuration of the reading light guiding unit. Thus, the length of the illumination optical path and the length of the reading optical path can be kept constant no matter where the moving unit 3 moves. Thereby, image reading performance can be maintained. Further, since the lens box 30 having the illumination light guide means for forming the illumination light path and the reading light guide means for forming the reading light path can be accommodated in the moving unit 3, the length of the illumination light path and the length of the reading light path can be accommodated. No other moving body is required to keep the image constant, and the moving body in the image reading apparatus 300 is only the moving unit 3. As a result, the space for arranging the moving body and the space for moving the moving body need only be one moving body. Therefore, the space for the moving body can be saved, and the apparatus main body can be reduced in size. it can.
Further, the reading light guide means includes a second turning mirror M2 and a third turning mirror M3, which are two mirror surfaces facing each other, and the second turning mirror before the reading light reaches the imaging device 2 from the document surface. Since the directional mirror M2 and the third deflecting mirror M3 are configured to reciprocate at least once, the moving unit 3 provided with the reading light guiding means can be reduced in size while ensuring the length of the reading light path. Can do.
The second turning mirror M2 and the third turning mirror M3 are also used as illumination light guiding means, and the second turning mirror M2 and the second turning mirror M2 are used until the illumination light reaches the document surface from the illumination device 1. Since it is configured to reciprocate at least once with the third turning mirror M3, it is possible to reduce the size of the moving unit 3 provided with the illumination light guiding means while ensuring the length of the illumination light path. Further, by providing a common member for the illumination light guide means and the reading light guide means, it is possible to reduce the weight of the moving unit 3 and reduce the manufacturing cost.
In the image reading apparatus 300 according to the first embodiment, the illumination light guide unit includes the first turning mirror M1 having a parabolic mirror surface as the light collecting unit that collects the illumination light, and the first turning mirror M1 includes the first turning mirror M1. It also has a function as a reading light guiding means, and the vicinity through which the optical axis of the reading light of the first turning mirror M1 passes is a plane mirror unit 204 as a non-condensing part that does not have a condensing function. As a result, even if the common member for the illumination light guiding means and the reading light guiding means has a condensing function, the condensing function can prevent the read image from being distorted.
Further, in the configuration of the first embodiment, instead of providing the first deflecting mirror M1 with the plane mirror unit 204, the reading light distortion correcting unit that corrects the distortion caused by the reading light passing through the first deflecting mirror M1 is provided. A correction lens 203 may be provided.
As shown in FIG. 8, the imaging device 2 includes a CCD 202 as a one-dimensional imaging device capable of imaging the entire area of the document in the main scanning direction, and includes two illumination devices 1 as illumination means. Is a configuration in which the illumination light emitted from each light source is divided in the main scanning direction and overlapped on the document surface. The first illumination device 1a and the second illumination device 1b, which are two illumination devices, are arranged in the main scanning direction. The first illuminating device 1 a and the second illuminating device 1 b are arranged so as to sandwich the imaging device 2, and each other in the main scanning direction (arrow B direction) with the reading optical axis Lr of the reading light incident on the imaging device 2 as a boundary. It is configured to illuminate the document surface on the opposite side. With this configuration, specularly reflected light does not enter the imaging lens 201 from any of the light sources 101, and white streaks can be prevented from occurring on the read image.
As shown in FIG. 12, the illumination device 1 and the imaging device 2 are arranged so that the illumination optical axis Li of the illumination light and the read optical axis Lr of the read light do not coincide on a plane orthogonal to the main scanning direction. Changed the tilt. Alternatively, as shown in FIGS. 13 to 17, the installation positions of the illumination device 1 and the imaging device 2 are changed. In this way, the focusing mirror 109, which is a focusing means for focusing the illumination light in the sub-scanning direction on the document surface, by making the illumination optical axis Li and the reading optical axis Lr inconsistent on a plane orthogonal to the main scanning direction. Can be configured such that the reading light does not enter the focusing mirror 109 even if it is disposed on the optical path of the illumination light, so that the reading image can be prevented from being distorted by the focusing mirror 109.
12 to 17 is a reflecting mirror as a focusing unit that focuses the illumination light before the illumination light reaches the document surface from the illumination device 1. A focusing mirror 109 is provided. In the mirror box 30, each deflecting mirror, which is a reflecting mirror, is arranged in order to secure an illumination optical path in a limited space. By using the converging mirror 109 as one of the deflecting mirrors, the deflecting mirror as the illumination light guiding unit can be provided with a condensing function. Thereby, it is not necessary to separately provide a lens member having a condensing function other than the mirror member that forms the illumination optical path, and the weight of the lens barrel 30 and the moving unit 3 can be reduced.
Further, by using a parabolic mirror as the focusing mirror 109, a reflecting mirror having a condensing function can be realized.
Further, even if an ellipsoidal mirror is used as the focusing mirror 109, a reflecting mirror having a condensing function can be realized.
Also, as shown in FIGS. 12 to 17, the illumination optical axis is set so that the reading optical axis Lr is perpendicular to the plane of the contact glass 6 that is the normal direction of the original surface on a plane orthogonal to the main scanning direction. By tilting Li, the regular reflection light Ld of the illumination optical axis Li on the plane of the contact glass 6 can also be made inconsistent with the reading optical axis Lr. As a result, it is possible to prevent the regular reflection light of the illumination light on the document surface or the surface of the contact glass 6 from entering the imaging lens 201, and to prevent the image quality from deteriorating.
Further, as shown in FIG. 13, the second turning mirror M2 constituting the reading term guiding means is a reflecting mirror having a transmission part β, and at a position facing the back side of the second turning mirror M2, By adopting a configuration in which the light emitting position where the illumination device 1 emits illumination light is arranged at a position facing the transmission part β, the alignment of the reflecting mirrors for adjusting the reflection angles at two locations above and below the light emitting position is one. The alignment of the two members can be completed, and the reflection angle can be easily adjusted.
Further, as shown in FIGS. 14 to 17, the fourth turning mirror M4, the third turning mirror M3, and the focusing mirror 109 (the fifth turning mirror M5 in FIGS. 15 and 17 are also illumination light guiding means). Including) reflects the illumination light in a space different from the space in which the reading light reciprocates between the two mirror surfaces of the second turning mirror M2 and the third turning mirror M3, and guides it to the reading area A on the document surface. is doing. As a result, even if dust or dirt adheres to the corner mirror of the illumination light guiding means and flare of the illumination light occurs, the flare light does not easily enter the integrated lens 104. Dust or dust may adhere to the mirror surface that reflects the illumination light over a long period of use, but even if it adheres, the generated flare light does not easily enter the imaging lens 201, resulting in a reduction in image quality. Can be avoided.
Further, as shown in FIGS. 15 and 17, a space in which the reading light reciprocates between two mirror surfaces of the second turning mirror M2 and the third turning mirror M3, and a fourth turning mirror that is an illumination light guiding means. M4, the third turning mirror M3, and the focusing mirror 109 (including the fifth turning mirror M5 in FIG. 15) are the fourth turning mirror M4, the third turning mirror M3, and the focusing light, which are illumination light guiding means. The mirror 109 (including the fifth turning mirror M5 in FIG. 15) is provided with a third turning mirror M3, which is a mirror that can be reflected on both sides, at the boundary with the space that guides the illumination light. Accordingly, the flare light generated is prevented from entering the imaging lens 201 and is reflected by both surfaces of the third turning mirror M3, thereby effectively using the space in the mirror case 30 and the reading optical path. An illumination optical path can be formed.
Further, since the copying machine, which is an image forming apparatus, includes the image reading apparatus 300 as an image reading unit, image reading performance can be maintained, so that favorable image formation can be performed. Since the size can be reduced, the copying machine including the size can also be reduced.

FIG. 3 is an explanatory perspective view of the image reading apparatus according to the embodiment. 1 is a schematic configuration diagram of a copier according to an embodiment. Explanatory drawing of the illuminating device which concerns on embodiment, (a) is upper surface explanatory drawing, (b) is front explanatory drawing, (c) is an illuminating device which can irradiate illumination light to an illumination object surface efficiently. Front explanatory drawing of the 1st example, (d) is a front explanatory drawing of the 2nd example of the illuminating device which can irradiate illumination light to an illumination object surface efficiently. FIG. 6 is an illuminance distribution diagram in the sub-scanning direction of a reading area. A perspective view of the lens, (a) is a cylinder lens array that can be used as a condenser lens or illumination lens, (b) is a second focusing lens in the sub-scanning direction, (c) is an integrated lens, (d) is Sub-scanning direction focusing lens. Model diagram of illuminance distribution in the sub-scanning direction, (a) shows a case where LEDs are arranged in a line, and (b) shows a case where LEDs are arranged corresponding to CCDs corresponding to respective colors. Explanatory drawing of the structure which arranged the illuminating device side by side in the direction corresponding to a subscanning direction, (a) is upper surface explanatory drawing, (b) is front explanatory drawing. An explanatory top view of a configuration including two illumination devices, (a) is an explanatory diagram of a configuration in which two illumination devices illuminate the entire illumination area, and (b) is an illumination region in which the two illumination devices are different from each other. Explanatory drawing of the structure which illuminates an area | region. Explanatory drawing of the width | variety required for a mirror, (a) is explanatory drawing of a reading optical path, (b) is explanatory drawing of an illumination optical path. The perspective explanatory view of the cylinder lens made into the Fresnel lens. FIG. 3 is an explanatory front view of the moving unit according to the first embodiment. Front explanatory drawing of the movement unit of Example 2. FIG. Front explanatory drawing of the moving unit of Example 3. FIG. Front explanatory drawing of the movement unit of Example 4. FIG. Front explanatory drawing of the movement unit of Example 5. FIG. Front explanatory drawing of the movement unit of Example 6. FIG. FIG. 10 is an explanatory front view of a moving unit according to a seventh embodiment. The perspective view of a parabolic mirror.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Illuminating device 2 Imaging device 3 Moving unit 4 Housing 6 Contact glass 10 Intermediate transfer belt 17 Belt cleaning device 18 Image forming unit 20 Tandem image forming unit 21 Exposure device 25 Fixing device 30 Lens box 31 Image reading unit 40 Photosensitive drum 42 Supply Paper roller 61 Development unit 62 Primary transfer roller 63 Photoconductor cleaning device 100 Printer unit 101 Light source 101a LED
101b Rotating paraboloid mirror 102 Condensing lens 102a Condensing cylinder lens 103 Illumination lens 103a Illumination cylinder lens 104 Integrated lens 105 Sub-scanning direction focusing lens 106 Sub-scanning direction second focusing lens 107 Sub-scanning direction illumination lens 108 Sub-scanning direction integration Lens 109 Focusing mirror 200 Paper feed unit 201 Imaging lens 202 CCD
300 Image reading device 400 Document transport unit

Claims (14)

Illumination means for emitting illumination light;
Illumination light guide means for guiding the illumination light emitted by the illumination means to the document surface;
Imaging means for imaging based on incident light;
Reading light guide means for guiding the reading light reflected by the document surface to the imaging means;
A moving unit movable in a predetermined direction parallel to the document surface,
The moving unit includes: an irradiating unit that illuminates the illumination light toward the document surface; and a light receiving unit that receives the reading light reflected from the document surface by the reading light guide unit.
The illumination means includes a light source that emits the directional illumination light, an illumination light dividing means that divides the illumination light into a plurality of divided lights, and an illumination area of each of the plurality of divided lights on the original surface. In an image reading apparatus comprising split light guide means for guiding the split light so as to overlap on a document surface,
The moving unit includes the entire configuration of the illumination unit, the imaging unit, the illumination light guide unit, and the read light guide unit ,
The illumination light guiding means includes two mirror surfaces facing each other, and the reading illumination light makes at least one reciprocation between the two mirror surfaces until the illumination light reaches the document surface from the illumination means. An image reading apparatus configured as described above . The image reading apparatus according to claim 1.
The two mirror surfaces are used as the reading light guide means so that the reading light reciprocates at least once between the two mirror surfaces until the reading light reaches the imaging means from the original surface. An image reading apparatus characterized by comprising . The image reading apparatus 請 Motomeko 2,
The image reading apparatus, wherein the illumination light guiding means guides the illumination light in a space different from a space in which the reading light reciprocates between the two mirror surfaces. The image reading apparatus according to claim 3 .
An image reading apparatus characterized in that a mirror surface body capable of reflecting on both sides is provided at a boundary between a space in which the reading light reciprocates between the two mirror surfaces and a space in which the illumination light guiding means guides the illumination light. . 請 Motomeko 1,2, 3 or in the image reading apparatus 4,
The illumination light guide means includes a light collecting means for collecting the illumination light,
The condensing means also has a function as the reading light guiding means, and a non-condensing portion that does not have the condensing function of the condensing means is provided in the vicinity of the optical axis of the reading light of the condensing means. An image reading apparatus. The image reading apparatus according to claim 1, 2, 3, 4 or 5,
The illumination light guide means includes a light collecting means for collecting the illumination light,
The condensing means also has a function as the reading light guiding means, and the reading light is provided at a position through which the optical axis of the reading light passes before the reading light emitted from the condensing means reaches the imaging means. An image reading apparatus comprising reading light distortion correction means for correcting distortion caused by passing through the light condensing means. Claim 1, 2, 3, 4, 5 or in the image reading apparatus 6,
The imaging device as the imaging means includes a one-dimensional imaging element capable of imaging the entire area of the document in the main scanning direction,
The illuminating device includes two illuminating devices, and the illuminating device divides the illuminating light in the main scanning direction and superimposes them on the document surface,
The two illumination devices are arranged so as to sandwich the imaging device in the main scanning direction,
The two illuminating devices are configured to illuminate document surfaces opposite to each other in the main scanning direction with the optical axis of the reading light incident on the imaging device as a boundary. The image reading apparatus according to claim 1, 2, 3, 4, 6 or 7,
An image reading apparatus, wherein the optical axis of the illumination light and the optical axis of the reading light do not coincide with each other on a plane orthogonal to the main scanning direction. The image reading apparatus according to claim 1,2,3,4,5,6, 7 or 8,
A focusing means for focusing the illumination light before the illumination light reaches the original surface from the illumination means;
An image reading apparatus characterized in that the focusing means is a reflecting mirror. The image reading apparatus according to claim 9 .
The image reading apparatus, wherein the reflecting mirror is a parabolic mirror. The image reading apparatus according to claim 9 .
An image reading apparatus, wherein the reflecting mirror is an ellipsoidal mirror. The image reading apparatus according to claim 1,2,3,4,5,6,7,8,9,1 0 or 11,
On the plane orthogonal to the main scanning direction, the angle formed by the optical axis of the illumination light and the original surface, and the reflection angle formed by the optical axis of the reading light and the original surface are different from each other. An image reading apparatus, wherein an axis and an optical axis of the reading light are not symmetrical with respect to a normal line of the original surface. The image reading apparatus according to claim 1,2,3,4,5,6,7,8,9,10,1 1 or 12,
The reading light guiding means or the illumination light guiding means includes a reflecting mirror having a transmission part,
An image reading apparatus characterized in that a light emitting position where the illuminating means emits the illumination light is arranged at a position facing the back side of the reflecting surface of the reflecting mirror and at a position facing the transmitting portion. Image reading means;
In an image forming apparatus having image forming means for forming an image on a recording body based on image information read by the image reading means,
As the image reading means, according to claim 1,2,3,4,5,6,7,8,9,10,11,1 2 or the image forming apparatus, which comprises using the image reading apparatus 13.

Images