JP2008116527A - Light source unit, reader, image reader and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light source contributing to satisfactory image reading or image forming by achieving illumination and reading free from irregular density and irregular color. <P>SOLUTION: Luminous fluxes 12a, 13a and 14a emitted from respective LEDs 12, 13 and 14, and reflected by reflectors 15, 16 and 17 are guided toward a contact glass 11 by a light transmission plate 18. A plurality of light incident surfaces 18a, 18b and 18c respectively corresponding to the light emitting parts of the respective LEDs 12, 13 and 14 are formed on the light transmission plate 18 so that the adjacent light incident surfaces may have an angle to each other in order to condense and superpose the luminous fluxes 12a, 13a and 14a on the surface of an original on the contact glass 11. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a light source unit that irradiates a surface to be illuminated with light emitted from a light source through a light guide member, and relates to a reading apparatus, an image reading apparatus, and an image forming apparatus having the light source unit as a part of the configuration.

  In recent years, light emitting diodes (hereinafter referred to as LEDs) have been actively developed, and the development of LED elements has progressed, and the brightness thereof has increased rapidly. LEDs generally have advantages such as long life, high efficiency, high G resistance, and monochromatic light emission, and are expected to be applied in many lighting fields. One of the applications is a document illumination device of an image reading apparatus such as a digital copying machine or an image scanner.

  As an example of a document illumination device, there is a device that uses a light guide plate made of a prism or the like that can efficiently and uniformly guide light emitted from a light source to a document surface (see Patent Documents 1 to 3).

  FIG. 12 is a basic configuration diagram of a light source unit using a conventional light guide plate. 1 is a contact glass on which a document to be illuminated is placed, 2, 3 and 4 are red (R), green (G), Blue (B) three primary color LEDs, 5, 6, and 7 are reflectors disposed on the LEDs 2, 3, and 4, and 8 is a shape that extends from the installation side of the LEDs 2, 3, and 4 toward the contact glass 1. This is a light guide plate made of a plate-shaped optical material.

  In FIG. 12, LEDs 2, 3, and 4 for R, G, and B are arranged side by side in the main scanning direction with the exit surface facing away from the contact glass 1 side that is the original surface. Are provided with dome-shaped reflectors 5, 6, and 7.

The light beams La, Lb, and Lc emitted from the LEDs 2, 3, and 4 are reflected to the contact glass 1 side by the reflecting plates 5, 6, and 7, respectively. Since the light guide plate 8 is disposed between the contact glass 1 and the LEDs 2, 3, 4, the light beams La, Lb, Lc are guided through the inside of the light guide plate 8 and the original on the contact glass 1. Reach the plane.
JP 2005-229647 A JP 2005-252646 A JP 2006-67551 A

  However, in the prior art, since the LEDs 2, 3, 4 are arranged side by side, the irradiation area on the document surface corresponding to the LEDs 2, 3, 4 is as shown in FIG. The arrangement intervals (pitch) of 3 and 4 are shifted in the main scanning direction by the respective colors of R, B, and G, causing uneven illumination.

  In an image reading apparatus of an inexpensive facsimile machine on which the original illumination device is mounted, it is not a big problem because the data is binarized in black and white. In such cases, density irregularities and color irregularities occur, resulting in a problem that good image data cannot be obtained.

  Patent Documents 1 to 3 describe inventions that solve various problems in this type of document illumination device.

  Patent Document 1 describes a configuration of an illumination unit including a light source on one end face of a light guide, but there is a problem that a clear read image cannot be obtained due to insufficient illumination light quantity.

  Patent Document 2 describes a configuration of an illuminating device in which an illumination unit using R, G, and B color LEDs and a light guide plate is connected in the main scanning direction. Color unevenness occurs, and a good read image cannot be obtained.

  Patent Document 3 describes a configuration of an illuminating device that illuminates a document surface using LEDs arranged in the main scanning direction and having a length equal to the length of the LED array as a light guide plate. Since a light guide plate that is long in the main scanning direction is required, there is a problem that the cost is increased.

  An object of the present invention is to solve the above-mentioned problems of the prior art, enable illumination and reading without density unevenness and color unevenness, and contribute to good image reading or image formation, a reading device, an image reading device, An object is to provide an image forming apparatus.

  In order to achieve the object, the invention according to claim 1 is directed to a light source unit that irradiates a surface to be illuminated by guiding light emitted from a plurality of light sources through the light guide member. A different light incident surface corresponding to each light emitting portion of each of the light sources is formed so that the emitted light is superimposed on the irradiated surface. Without being provided, the light emitted from the light source can be polymerized on the irradiated surface by the light guide member, so that the emitted light can efficiently and uniformly illuminate, and the density unevenness compared to the conventional light source unit. Or lighting without color unevenness becomes possible.

  According to a second aspect of the present invention, in the light source unit according to the first aspect, the light incident surfaces of the light guide member are formed at an angle to each other. Thus, the polymerization of the emitted light is favorably performed.

  According to a third aspect of the present invention, in the light source unit according to the first or second aspect, the plurality of light sources are a red light emission light source, a green light emission light source, and a blue light emission light source. White illumination with no color unevenness can be achieved by polymerization of R, G, and B light.

  According to a fourth aspect of the present invention, in the light source unit according to any one of the first to third aspects, the light source is a light emitting diode.

  According to a fifth aspect of the present invention, in the reading apparatus that reads reflected light from the reading object illuminated by the light source onto the imaging element with an imaging lens and reads the reading object in a one-dimensional manner, the light source is as described in the first aspect. 4. The light source unit according to any one of 4 is installed, and stable and satisfactory reading can be performed by using the light source unit having no density unevenness or color unevenness.

  According to a sixth aspect of the present invention, in the reading apparatus that reads the read target one-dimensionally, the reflected light from the read target illuminated by the light source is imaged on the imaging element by the imaging lens. 4. A plurality of light source units as set forth in any one of 4 are provided, and by this configuration, a plurality of light source units having no density unevenness or color unevenness are used, so that more stable and good with a larger amount of light. Reading can be performed.

  According to a seventh aspect of the present invention, in the reading device according to the fifth or sixth aspect, the light source unit, the imaging lens, and the imaging device are integrally attached to the apparatus main body. Assembly can be simplified.

  According to an eighth aspect of the present invention, in the reading device according to any one of the fifth to seventh aspects, the light source unit according to any one of the first to fourth aspects, or an illumination unit comprising a plurality of the light source units. Are arranged so that the light emitting sides face in the same direction. It is possible to prevent the occurrence of problems such as.

  The invention according to claim 9 is characterized in that, in the reading device according to claim 8, the number of light sources in the light source unit of the illumination unit is appropriately changed in each light source unit, and the light emission amount by the part is adjusted by this configuration. Thus, it is possible to eliminate the peripheral light reduction based on the cos 4th law indicating the relationship between the aperture angle and the peripheral light attenuation in the imaging lens, that is, the shortage of light quantity around the lens.

  The invention according to claim 10 is characterized in that, in the reading device according to claim 8, the power supplied to the light source unit of the illumination unit is appropriately non-uniform, and by this configuration, the amount of light emitted by the part is adjusted, It is possible to eliminate the peripheral light reduction based on the cos 4 power law indicating the relationship between the aperture angle and the peripheral light attenuation in the imaging lens, that is, the shortage of the light amount around the lens.

  The invention according to claim 11 is the reading device according to any one of claims 5 to 10, wherein a lid is provided on the apparatus body, and the light source unit or the illumination unit is held by the lid. With this configuration, it is possible to secure a distance between the heat source of the constituent members in the apparatus main body and the light source unit or the lighting unit, and it is possible to prevent thermal stress from occurring.

  According to a twelfth aspect of the present invention, in the reading device according to the eleventh aspect, the apparatus main body and the lid body are detachably engaged. With this configuration, without using a fixing screw or the like, Easy and simple assembly and disassembly.

  According to a thirteenth aspect of the present invention, in the reading device according to the eleventh or twelfth aspect, a lid locking portion is provided in a reading optical system setting portion including an image pickup element and an optical system that are set in the apparatus main body. It can be assembled and disassembled with a simple structure, and the number of parts can be reduced and the cost can be reduced.

  The invention described in claim 14 is characterized in that, in the reading device according to any one of claims 11 to 13, the light source unit or the illumination unit is sandwiched and fixed by the reading optical system installation portion and the lid. Thus, the reading optical system installation part and the light source unit or the illumination unit are brought close to each other, so that a simpler fixing structure can be achieved, and the number of parts can be further reduced and the cost can be reduced.

  According to the fifteenth aspect of the present invention, a reflected light from an original illuminated by a light source is imaged on an image sensor by an imaging lens, an image of the original is read one-dimensionally, and scanned to scan a two-dimensional image. An image reading apparatus including a document reading unit for reading a two-dimensional image by mounting the reading device according to claim 5 as the document reading unit and running the reading device in a sub-scanning direction. With this configuration, it is possible to read a good two-dimensional image, and it is possible to read a color image without density unevenness or color unevenness.

  According to the sixteenth aspect of the present invention, the reflected light from the original illuminated by the light source is imaged on the image sensor by the imaging lens, the image of the original is read one-dimensionally, and scanned to scan the two-dimensional image. 16. An image forming apparatus comprising: a document image reading unit that reads image data; and an image forming unit that receives image information from the document image reading unit and forms an image on a recording medium. The image reading apparatus described above is mounted. With this configuration, it is possible to form a good image, and it is possible to form a color image without uneven density or uneven color.

  According to the light source unit of the present invention, the light emitted from the light source is superposed on the irradiated surface by the light guide member without providing a complicated optical system, so that the illumination with the emitted light can be performed efficiently and uniformly. Compared with a conventional light source unit, illumination without uneven density or uneven color becomes possible.

  Moreover, according to the reading apparatus using the light source unit according to the present invention, it is possible to perform stable and favorable reading particularly corresponding to a color image.

  In addition, according to the light source unit, the image reading apparatus using the reading apparatus, and the image forming apparatus according to the present invention, it is possible to read a good image and form an image. Formation can be performed.

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

  FIG. 1 is a schematic configuration diagram of a color image forming apparatus which is an embodiment of an image forming apparatus according to the present invention, in which 100 is an image forming unit, 200 is a sheet feeding unit, 300 is an image reading unit, and 400 is document feeding. Part.

  The image forming unit 100 is arranged around the photoconductors 101a, 101b, 101c, and 101d on which toner images corresponding to R, G, and B colors and black (Bk) are formed, and the photoconductors 101a to 101d. A known electrophotographic image forming process 106 including a charging unit 102, an exposure unit 103, a toner developing unit 104, and a cleaning unit 105 is provided, and each of the photosensitive members 101 a to 101 d is in contact with each of the intermediate transfer units 107. An intermediate transfer belt 108 on which a toner image is transferred and a color toner image is formed on the surface, and a transfer for transferring the color toner image on the surface of the intermediate transfer belt 108 to a sheet as a recording medium conveyed by a registration roller 109 Part 110 is installed.

  Further, the sheet on which the color toner image is transferred by the transfer unit 110 is sent to the fixing unit 112 by the conveyance belt 111, and the toner image is fixed. It is discharged to 114.

  Also, in the vicinity of the fixing unit 112, an image is formed on the other side of the sheet on which the image is formed on one side, so the conveyance path switching claw 115 for reversing the sheet and conveying it again to the registration roller 109 and the sheet reversal A device 116 is installed.

  The paper feeding unit 200 transports the paper P from a plurality of paper feeding cassettes 201 containing paper P and the paper feeding cassette 201 containing paper P selected for use to the registration roller 109. A roller 202, a conveyance guide 203, and the like are installed.

  The image reading unit 300 includes a light source unit, a document reading unit, and the like according to the present invention described later, and moves on the document placed on the contact glass 401 below the document feeding unit 400 or on the contact glass 401. A document to be read is irradiated with light, and the reflected light is imaged on an image pickup element by an imaging lens, and photoelectrically converted to read image data to be read. In the image reading unit 300, the document reading unit is scanned in the horizontal direction (sub-scanning direction) at a predetermined speed by a driving device (not shown) so as to read a two-dimensional image of the document.

  The document feeder 400 is provided with a document placement table 402, a document discharge tray 403, and a document transport roller 404. The document transport roller 404 passes a document from the document mount table 402 to the document discharge tray 403 through the contact glass 401. It is configured to carry.

  FIG. 2 is a schematic configuration diagram for explaining Embodiment 1 of the light source unit according to the present invention.

  In the light source unit 10 of FIG. 2, reference numeral 11 denotes a contact glass on which a document to be illuminated is placed, and 12, 13 and 14 are directed side by side in the main scanning direction with the exit surface facing away from the contact glass 11 side. The red (R), green (G), and blue (B) primary color LEDs 15, 16, and 17, which are light sources arranged in the, are curved reflectors arranged corresponding to the LEDs 12, 13, and 14, respectively. , 18 is a light guide plate as a light guide member made of a plate-like optical material having a shape that expands from the installation side of the LEDs 12, 13, 14 toward the contact glass 11.

  On the light guide plate 18, light beams (showing only the optical axis) 12 a, 13 a, and 14 a that are emitted from the LEDs 12, 13, and 14 and reflected by the reflection plates 15, 16, and 17 pass through the light guide plate 18. A plurality of light incident surfaces 18a, corresponding to each of the light emitting portions of the respective LEDs 12, 13, 14 so as to be led and condensed on the surface of the original as an irradiated surface on the surface of the contact glass 11. 18b and 18c are formed with an angle between adjacent ones.

  As shown in FIG. 2, in the light incident surfaces 18a, 18b, 18c of the light guide plate 18 corresponding to the respective LEDs 12, 13, 14, the light incident surface 18b is parallel to the light emitting surface of the green LED 13 disposed in the middle. It is formed and reaches the original surface at the optical axis 13a indicated by the solid line. The light incident surface 18a corresponding to the red LED 12 is inclined at an angle as shown in the figure, and reaches the document surface at the optical axis 12a indicated by a one-dot chain line. The light incident surface 18c corresponding to the blue LED 14 is inclined so as to be substantially symmetrical with the light incident surface 18a corresponding to the red LED 12, and is configured to reach the document surface at the optical axis 14a indicated by the broken line. Yes.

  In this configuration, light emitted from the LEDs 12, 13, and 14 does not reach the light incident surfaces of the other LEDs, and the light incident surfaces 18a, 18b, and 18c of the light guide plate 18 are different from each other. The one-to-one relationship is maintained and no color mixing occurs.

  The inclination angles of the light incident surfaces 18a, 18b, and 18c are based on design level parameters such as the distance to the surface (document surface) of the contact glass 11 and the shapes of the curved reflectors 15, 16, and 17, for example. Can be set optimally.

For example, the inclination angles θ of the light incident surfaces 18a and 18b and the light incident surfaces 18b and 18c shown in the explanatory diagram of FIG. 3 are determined by the refractive index n of the light guide plate 18 made of an optical material such as a prism and between the LEDs. In the relationship between the distance X and the distance Y between each LED and the contact glass surface, the following equation is satisfied.
sinθ = n · sinΦ
Y = (X · tan θ) / 2 + X / (tan (θ−Φ))
However, (PHI) is the angle which the incident light to the light-guide plate 18 of LED and the perpendicular with respect to a light-incidence surface make.

  Moreover, as the reflecting plates 15, 16, and 17, for example, reflecting mirrors having a substantially parabolic curved surface are used.

  With the light source unit of the present embodiment having the above-described configuration, the irradiation areas of the respective color LEDs 12, 13, and 14 on the document surface can be matched, and the RGB light is superimposed (superposed). The function and effect of the use, that is, the illumination light can be efficiently and uniformly illuminated, and the white illumination without density unevenness and color unevenness can be realized.

  FIG. 4 is a schematic configuration diagram showing Embodiment 1 of the reading apparatus according to the present invention on which the light source unit shown in FIG. 2 is mounted.

  In the light source unit 10 having the above-described configuration, the exit surface portion 20 of the light guide plate 18 has an angle and is inclined in the sub-scanning direction, and the illumination light La emitted from the exit surface portion 20 is emitted from the exit surface portion of the light guide plate 18. The reading area on the contact glass 11 is uniformly illuminated by being guided to 20.

  The reflected light Lb from the reading area is reflected by the first mirror 22 and then reflected by the second and third mirrors 21 and 23 twice, and is imaged by the imaging lens 24 onto the CCD 25 which is an image sensor. Dimensional image reading is performed. The CCD 25 is a 3-line CCD corresponding to each color of RGB and can read a color image. As a result, a color image without color unevenness can be read.

  FIG. 5 is a schematic configuration diagram for explaining Embodiment 2 of the light source unit according to the present invention.

  In FIG. 5, a plurality of light source units 10 (three in this example) are provided side by side in the main scanning direction, and the illumination unit 27 can arbitrarily secure an illumination width in the main scanning direction. In this illumination unit 27, since the illumination by each light source unit 10 is uniform, even if a plurality of light source units 10 are connected in a line, uniform illumination can be realized on the entire document surface.

  Further, the number of light source units 10 to be connected can be adjusted according to the required illumination range (length in the main scanning direction). For example, by connecting three A4 size scanners and four A3 size scanners, various illumination units can be designed.

  FIG. 6 is a schematic block diagram showing Embodiment 2 of the reading apparatus according to the present invention.

  6 differs from the first embodiment of FIG. 3 in that it has a double-sided illumination configuration. The light source unit 10 or the illumination unit 27 is opposed to both sides of the reading optical axis. A plurality of light emitting sides are installed so that they face in the same direction. In this way, by arranging the light source unit 10 or the illumination unit 27, the illumination light is emitted from both sides of the reading optical axis, so that the reading surface is substantially uniform regardless of the state of the reading target. It is possible to prevent the shadow of the cut and pasted document, and to reduce the shadow of the binding portion of the document.

  FIG. 7 is a schematic block diagram showing Embodiment 3 of the reading apparatus according to the present invention.

  As shown in FIG. 7, the reading apparatus has a configuration of non-uniform illumination, and shows a configuration example of a light source group (light source unit) divided into a plurality (divided into three in this example). The light source unit 10 made of LEDs is installed in the center, and the illumination units 27 made of 6 LEDs are installed on both sides thereof, and is composed of a total of three light source groups.

  In this way, by setting the number of LEDs in the central light source unit 10 to be smaller than the LEDs in the side illumination unit 27, the illumination on the original surface is illuminated at a dark central portion in the main scanning direction as shown in FIG. Distribution. As a result, the shortage of the peripheral light quantity of the cos 4th law as the cause of the peripheral dimming in the imaging lens 24 is solved.

  The same effect can also be realized by changing the power supplied to each light source unit 10 or lighting unit 27 (for example, when three units are installed, the power for the central unit is reduced relative to the other units). it can. In this case, there is a merit that a plurality of light source units 10 or illumination units 27 having the same configuration can be used.

  FIG. 9 is a cross-sectional view showing Structure Example 1 of the apparatus main body in the reading apparatus of the embodiment.

  In FIG. 9, the apparatus main body 28 of the reading apparatus includes a lower casing 29 and an upper lid 30. The upper lid 30 is attached to and detached from the lower casing 29 so that the upper lid 30 covers the upper opening of the lower casing 29. The light source unit 10 or the illumination unit 27 is fixed in the upper lid 30, and the light emission window 31 is arranged so that the emitted light L is directed toward the contact glass 11 on the upper wall of the upper lid 30. Is formed.

  Thus, by providing the light source unit 10 or the illumination unit 27 in the upper lid 30, the distance from the substrate on which the drive circuit of the CCD 25 serving as a heat source installed in the lower housing 29 is mounted, The reading light path of the light source unit 10 or the illumination unit 27 can be arranged.

  This configuration is effective as a measure against image quality degradation during document reading, for example, image noise in flare light. Furthermore, by disposing the light source on the upper surface side inside the apparatus, it is possible to secure a distance to the heat source, both the light source and the CCD substrate can be relieved of thermal stress, and the upper lid 30 of the apparatus main body 28 is mounted and disposed. This is also advantageous in simplifying the assembly man-hours.

  FIG. 10 is a perspective view showing a structure example 2 of the apparatus main body in the reading apparatus of the embodiment. The structure is basically the same as that of the structure example 1, but the upper lid 30 and the apparatus main body 28 are joined. One of the portions is provided with a fitting hole 32 that is a locking portion, and the other is provided with a locking hook 33 that is a locking portion that locks into the fitting hole 32, so that the upper lid 30 and the apparatus main body 28 are connected. The difference is that they are detachably engaged.

  With this configuration, assembly is simplified and the number of assembly steps can be reduced. Also, since no fixing screws are used, the number of parts can be reduced and the cost of the unit can be reduced.

  FIG. 11 is a cross-sectional view showing Structural Example 3 of the apparatus main body in the reading apparatus of the embodiment.

  In FIG. 11, the apparatus main body 28 of the reading apparatus is composed of a lower casing 29 and an upper lid 30, and a plurality of locking projections 34 provided on the side of the light source unit 10 or the illumination unit 27 are provided on the lower casing 29. The upper lid 30 is detachably placed on the lower casing 29 so that the upper lid 30 covers the upper opening of the lower casing 29 and the upper casing 30 is detachably mounted. The convex portion 34 is sandwiched between the lower casing 29 and the upper lid 30. Thereby, the light source unit 10 or the illumination unit 27 is detachably fixed inside the apparatus main body 28.

  With this configuration, the light source unit 10 or the illumination unit 27 can be easily attached to or disassembled from the apparatus main body 28, and the light source unit 10 or the illumination unit 27 can flare the emitted light L that is the read illumination light. It functions as a prevention member and can improve the read image quality.

  In this embodiment, reflected light from a document illuminated by a light source is imaged on an image sensor by an imaging lens, the image of the document is read one-dimensionally, and a two-dimensional image is read by scanning this. By using the light source unit, the illumination unit, or the reading device having the above-described configuration at an appropriate position of the image reading apparatus including the image reading unit and the color image forming apparatus having the image reading apparatus mounted thereon as shown in FIG. A three-dimensional image can be read, and a color image without density unevenness or color unevenness can be read.

  The present invention is applied to a light source unit that irradiates a surface to be illuminated by guiding light emitted from a plurality of light sources through a light guide member, and in particular, a reading device such as a digital copying machine, an image scanner, a digital photographic apparatus, and a facsimile apparatus. It is effective for use in lighting devices used in

1 is a schematic configuration diagram of a color image forming apparatus that is an embodiment of an image forming apparatus according to the present invention. Schematic block diagram for explaining Embodiment 1 of the light source unit according to the present invention Explanatory drawing for demonstrating the formula which sets the inclination angle of the light-incidence surface of the light-guide plate in this embodiment. FIG. 2 is a schematic configuration diagram showing a first embodiment of a reading apparatus according to the present invention on which the light source unit shown in FIG. 2 is mounted. Schematic block diagram for explaining Embodiment 2 of the light source unit according to the present invention Schematic configuration diagram showing Embodiment 2 of a reading apparatus according to the present invention Schematic configuration diagram showing Embodiment 3 of a reading apparatus according to the present invention Explanatory drawing which shows the illumination intensity of the document surface in Embodiment 3. Sectional drawing which shows the structural example 1 of the apparatus main body in the reader of this embodiment. The perspective view which shows the structural example 2 of the apparatus main body in the reader of this embodiment. The perspective view which shows the structural example 3 of the apparatus main body in the reader of this embodiment. Basic configuration diagram of a light source unit using a conventional light guide plate

Explanation of symbols

10 Light source unit 11 Contact glass 12, 13, 14 LED
15, 16, 17 Reflector 18 Light guide plates 18a, 18b, 18c Light incident surface 20 Output surface portions 21, 22, 23 Mirror 24 Imaging lens 25 CCD
27 Illumination unit 28 Device body 29 Lower casing 30 Upper lid 31 Light exit window 32 Fitting hole 33 Locking hook 34 Locking projection 300 Image reading unit

Claims (16)

  In a light source unit that irradiates a surface to be illuminated by guiding light emitted from a plurality of light sources through the light guide member, the light emitted from the light guide member is superimposed on the surface to be irradiated. A different light incident surface corresponding to each light emitting portion of each light source is formed.   The light source unit according to claim 1, wherein the light incident surfaces of the light guide member are formed at an angle to each other.   The light source unit according to claim 1, wherein the plurality of light sources are a red light emission light source, a green light emission light source, and a blue light emission light source.   The light source unit according to claim 1, wherein the light source is a light emitting diode.   5. The light source unit according to claim 1, wherein a reflected light from a reading object illuminated by a light source is imaged on an image pickup element by an imaging lens and the reading object is read one-dimensionally as the light source unit. A reader characterized by having installed.   5. The light source unit according to claim 1, wherein a reflected light from a reading object illuminated by a light source is imaged on an image pickup element by an imaging lens and the reading object is read one-dimensionally as the light source unit. A reading apparatus comprising a plurality of devices.   The reading apparatus according to claim 5 or 6, wherein the light source unit, the imaging lens, and the imaging device are integrally attached to an apparatus main body.   The light source unit according to any one of claims 1 to 4, or a plurality of illumination units including a plurality of the light source units are installed facing each other so that the light emission side faces the same direction. Item 8. The reading device according to any one of Items 5 to 7.   The reading apparatus according to claim 8, wherein the number of light sources in the light source unit of the illumination unit is appropriately changed in each light source unit.   The reading apparatus according to claim 8, wherein power supplied to the light source unit of the illumination unit is appropriately non-uniform.   The reading apparatus according to claim 5, wherein a lid is provided on the apparatus main body, and the light source unit or the illumination unit is held by the lid.   The reading apparatus according to claim 11, wherein the apparatus main body and the lid are detachably engaged.   The reading device according to claim 11 or 12, wherein a locking portion for the lid is provided in a reading optical system setting portion including an imaging element and an optical system provided in the device main body.   The reading apparatus according to claim 11, wherein the light source unit or the illumination unit is sandwiched and fixed by the reading optical system installation unit and the lid.   An image provided with a document reading unit that forms reflected light from a document illuminated by a light source on an image sensor with an imaging lens, reads the image of the document in one dimension, and scans this to read a two-dimensional image. An image reading device comprising: the reading device according to any one of claims 5 to 14 as the document reading portion; and reading the two-dimensional image by running the reading device in a sub-scanning direction. apparatus.   A reflected image from a document illuminated by a light source is imaged on an image sensor by an imaging lens, the image of the document is read one-dimensionally, and a two-dimensional image is read by scanning the image; 16. An image forming apparatus comprising an image forming unit that receives image information from a document image reading unit and forms an image on a recording medium, wherein the document reading device according to claim 15 is mounted as the document image reading unit. An image forming apparatus.

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