JP2010063163A - Image reading apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact image reading apparatus which has a long depth of focus. <P>SOLUTION: An image reading apparatus has: a first concave aspherical mirror which collimates light from a first mirror, which receives scattered light of light reflected on a document and reflects it in a sub scanning direction, and reflects it as a parallel pencil of rays; an aperture mirror which reflects light from the first aspherical mirror through an opening that is light-shielded therearound for selectively transmitting light; a second concave aspherical mirror which receives light from the aperture mirror and reflects it as convergent light; and a light receptor which receives light from the second mirror, which is provided on a light path of light converged by the second aspherical mirror and reflects light in a vertical direction to a document surface, and has a light receiving area to form an image corresponding to light from the opening, wherein an optical distance from the first aspherical mirror to the aperture mirror becomes longer than an optical distance from an irradiation part to the first mirror and an optical distance from the first mirror to the first aspherical mirror. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image reading apparatus used for image reading and image identification, such as a copying machine and a financial terminal device.

  As an image reading apparatus for reading image information, for example, Japanese Patent Laid-Open No. 11-8742, FIG. 2 (see Patent Document 1) discloses a reading apparatus using a mirror array.

  FIG. 2 (see Patent Document 2) of Japanese Patent Laid-Open No. 2003-331267 includes a telecentric optical system and an illumination system suitable for inspecting a plurality of inspected parts existing on a mounting substrate by one main scanning. A reader having the same is disclosed.

  Further, in FIG. 1 of JP-A-5-328024 (refer to Patent Document 3), a light source lamp 24 for irradiating the object to be read G with the beam and an optical beam from the object to be read G are transmitted. Optical means 20, 30 for performing the processing, an optical element 44 for dividing the optical beam from the optical means 20, 30 into a plurality of light beams separated by a predetermined distance, and an optical beam divided by the optical element 44. An image reading apparatus is disclosed that includes a plurality of detection units 46r, 46g, and 46b provided through different color filters at positions where each light is received.

Japanese Patent Laid-Open No. 11-8742 (FIG. 2) Japanese Patent Laying-Open No. 2003-331267 (FIG. 2) Japanese Patent Laid-Open No. 5-328024 (FIG. 1)

  However, in the device described in Patent Document 1, the mirror array on the optical path from the document 10 to the photosensor array 15 is parallel to the axis perpendicular to the reading surface of the document reading unit and the axis perpendicular to the light receiving surface of the photosensor array. Although it is configured to determine the inclination of the optical axis of the first and second mirror arrays, there is no detailed description regarding the specific installation position of the mirror array and the inclination of the optical axis.

  The one described in Patent Document 2 includes an epi-illumination light source 1 and a side illumination light source 4, and is composed of a first lens 9 made of a cylindrical lens and a second lens 7 of an imaging system, and the first lens 9 is a substrate to be inspected. Although a compact telecentric optical system is obtained by bringing the first lens 9 and the entrance pupil position of the second lens 7 to coincide with each other within 50 mm of the first lens 9, a detailed description regarding a specific installation position and scanning method is obtained. There is no.

  Further, the device described in Patent Document 3 has a problem that the structure is complicated because the focusing optical element 42 for changing the focal length for reading the RGB image information by the 3-line CCD sensor 46 is required.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an image reading apparatus having a small depth of focus and a small size.

  According to a first aspect of the present invention, there is provided an image reading apparatus according to a first aspect of the present invention, wherein a light source that irradiates light to an irradiating portion of a document over the main scanning direction The mirror, the concave first aspherical mirror that collimates the light from the first mirror and reflects it as a substantially parallel light beam, and the opening that is shielded from the surroundings and selectively allows the light to pass through. An aperture mirror that reflects light from the first aspherical mirror, a concave second aspherical mirror that receives light from the aperture mirror and reflects it as convergent light, and is converged by the second aspherical mirror A second mirror that is provided on the optical path of the light and reflects light in a direction perpendicular to the document surface, and a light receiving unit that receives light from the second mirror and forms an image corresponding to the light from the opening. A light receiving portion having a region, and at least the first A spherical mirror and the second aspherical mirror are installed on one side in the sub-scanning direction, and the aperture mirror is installed on the other side in the sub-scanning direction, and the first aspherical mirror to the aperture mirror Is longer than the optical distance from the irradiation unit to the first mirror and the optical distance from the first mirror to the first aspherical mirror.

  According to a second aspect of the present invention, there is provided the image reading apparatus according to the first aspect, wherein the aperture mirror is installed at a focal position of the first aspherical mirror.

  An image reading apparatus according to a third aspect of the present invention is the image reading apparatus according to the first aspect, wherein the aperture mirror is installed at a focal position of the second aspherical mirror.

  In an image reading apparatus according to a fourth aspect of the present invention, the first aspherical mirror and the second aspherical mirror are integrated, and the first aspherical mirror is disposed on the irradiation unit side, and the second nonspherical mirror is provided. 4. A spherical mirror according to claim 1, wherein the spherical mirror is installed on the light receiving unit side.

  5. The image reading apparatus according to claim 5, wherein the first mirror and the second mirror are installed linearly with respect to the normal line of the transport surface of the irradiated object. It is a thing of crab.

  According to a sixth aspect of the present invention, there is provided an image reading apparatus according to the sixth aspect, wherein the RGB light source for irradiating light to the irradiating portion of the original in the main scanning direction and the scattered light of the light reflected from the original are incident and reflected in the sub-scanning direction. Through a first mirror, a concave first aspherical mirror that collimates the light from the first mirror and reflects it as a substantially parallel light beam, and an aperture that is shielded from the surroundings and selectively allows light to pass through. An aperture mirror that reflects light from the first aspherical mirror, a concave second aspherical mirror that receives light from the aperture mirror and reflects it as convergent light, and the second aspherical mirror converges the light. And a second mirror that reflects the light in a direction perpendicular to the original surface, and the light from the second mirror is incident to form an image corresponding to the light from the opening. In the light receiving area, the optical wavelength of the RGB light source is adjusted. A light receiving unit having a corresponding RGB filter, at least the first aspherical mirror and the second aspherical mirror are installed on one side in the sub-scanning direction, and the aperture mirror is installed on the other side in the sub-scanning direction. An optical distance from the first aspherical mirror to the aperture mirror, an optical distance from the irradiating unit to the first mirror, and from the first mirror to the first aspherical mirror. It is characterized by being longer than the optical distance.

  According to a seventh aspect of the present invention, there is provided an image reading apparatus in which a fluorescent light source that irradiates fluorescence to an irradiation portion of a document in the main scanning direction and scattered light of light reflected by the document are incident and reflected in the sub-scanning direction. Through a first mirror, a concave first aspherical mirror that collimates the light from the first mirror and reflects it as a substantially parallel light beam, and an aperture that is shielded from the surroundings and selectively allows light to pass through. An aperture mirror that reflects light from the first aspherical mirror, a concave second aspherical mirror that receives light from the aperture mirror and reflects it as convergent light, and the second aspherical mirror converges the light. And a second mirror that reflects the light in a direction perpendicular to the original surface, and the light from the second mirror is incident to form an image corresponding to the light from the opening. Multiple colors with a wavelength longer than blue in the light receiving area A light receiving unit having a filter, a housing in which at least the first aspherical mirror and the second aspherical mirror are installed on one side in the sub-scanning direction, and the aperture mirror is installed on the other side in the sub-scanning direction; A low-pass filter that cuts a wavelength shorter than a blue wavelength in a light path between the fluorescent light source and the document, and an optical distance from the first aspherical mirror to the aperture mirror is from the irradiation unit to the first The optical distance to one mirror is longer than the optical distance from the first mirror to the first aspherical mirror.

  According to the image reading apparatus of the present invention, the sub-scanning is performed on the aperture mirror that reflects the light from the first aspherical mirror and the second aspherical mirror that receives the light from the aperture mirror and reflects it as convergent light. The aperture mirror is installed on the other side in the sub-scanning direction, and the optical distance from the first aspherical mirror to the aperture mirror is equal to the optical distance from the irradiation unit to the first mirror, and the first Since it is longer than the optical distance from the mirror to the first aspherical mirror, it is possible to obtain a compact image reading apparatus despite the deep subject depth.

1 is a cross-sectional view of an image reading apparatus according to Embodiment 1 of the present invention. 1 is a configuration diagram of an optical lens system of an image reading apparatus according to Embodiment 1 of the present invention. 1 is a configuration diagram of an optical mirror system of an image reading apparatus according to Embodiment 1 of the present invention. 1 is a plan view of an image reading apparatus according to Embodiment 1 of the present invention. It is a top view of the sensor board | substrate which concerns on Embodiment 1 of this invention. It is a top view of sensor IC concerning Embodiment 1 of this invention. It is a figure explaining the light source part containing the light guide which concerns on Embodiment 1 of this invention. It is a figure explaining the light source part containing the light guide which concerns on Embodiment 1 of this invention. 1 is a block configuration diagram of an image reading apparatus according to Embodiment 1 of the present invention. FIG. 3 is a connection diagram between sensor ICs of the image reading apparatus according to the first embodiment of the present invention. FIG. 6 is a connection diagram according to another example of the sensor IC of the image reading apparatus according to the first embodiment of the present invention. 3 is a timing chart of the image reading apparatus according to the first embodiment of the present invention. It is a principle figure explaining the optical path | route of the image reading apparatus which concerns on Embodiment 1 of this invention. FIGS. 14A and 14B are diagrams for explaining rearrangement of reverse image data of the image reading apparatus according to the first embodiment of the present invention. FIG. 14A illustrates a case where interpolation processing is not performed, and FIG. It is a figure explaining the optical distance of the subscanning direction of the image reading apparatus which concerns on Embodiment 1 of this invention. It is the figure which embodied the optical path of the subscanning direction of the image reading apparatus which concerns on Embodiment 1 of this invention. It is explanatory drawing of the light-shielding plate of the image reading apparatus based on Embodiment 1 of this invention, Fig.17 (a) is a side view which mounted the light-shielding plate in the optical lens system, FIG.17 (b) is a side view of a light-shielding plate. 17 (c) is a diagram showing the surface roughness of the light shielding plate. It is sectional drawing of the image reading apparatus which concerns on Embodiment 2 of this invention. It is a top view of the image reading apparatus which concerns on Embodiment 2 of this invention. It is a top view of the sensor board | substrate which concerns on Embodiment 2 of this invention. It is a figure explaining the optical distance of the subscanning direction of the image reading apparatus which concerns on Embodiment 2 of this invention. It is explanatory drawing of the light-shielding plate mounted in the optical lens system of the image reading apparatus which concerns on Embodiment 2 of this invention. FIG. 23A is an explanatory diagram when another LED light source is used in the image reading apparatus according to the third embodiment of the present invention, and FIG. 23A shows a light source portion including a light guide, and FIG. b) shows a partially enlarged view around the electrode part. It is explanatory drawing at the time of using another LED light source for the image reading apparatus which concerns on Embodiment 3 of this invention, and shows the case where a vertical light guide is used. It is a figure which shows the output of each wavelength in the case where the LED which uses purple light emission is used for the image reader which concerns on Embodiment 3 of this invention, and when it does not mount with the cut filter with respect to the fluorescence to generate | occur | produce.

Embodiment 1 FIG.
Hereinafter, an image reading apparatus according to Embodiment 1 of the present invention will be described with reference to FIG. FIG. 1 is a cross-sectional configuration diagram of an image reading apparatus according to the first embodiment. In FIG. 1, reference numeral 1 denotes an object to be irradiated such as a document or a medium (also referred to as an original), 2 denotes a top plate for supporting the object to be irradiated 1, 3 denotes a light guide for propagating light, and 3 a denotes light from the light guide 3. An emission part (emission part), 4 is a transmitting body that allows light to pass through, 5 is an irradiation part of light to the irradiated object 1, 6 is a first mirror that reflects scattered light from the irradiation part 5 in the sub-scanning direction, and 7 is A concave first lens mirror (also referred to as a first lens or a first aspherical mirror) that receives reflected light from the first mirror 6, 8 is an aperture mirror that receives parallel light from the first lens 7, and 9 is an aperture mirror. A concave second lens mirror (also referred to as a second lens or a second aspherical mirror) that receives the reflected light from 8, and 10 is an aperture mirror 8 that is shielded from the surroundings and relieves chromatic aberration of light incident on and reflected by the aperture mirror 8. The opening provided in the surface of the It receives light from 9, a second mirror for reflecting.

  Reference numeral 12 denotes a photoelectric conversion circuit that receives reflected light from the second lens 9 and performs photoelectric conversion, and a sensor IC having a MOS semiconductor configuration including its driving unit. Reference numeral 13 denotes a sensor substrate on which the sensor IC 12 is mounted. A signal processing IC (ASIC) 15 that processes the converted signal, 15 is an electronic component such as a capacitor and a resistor placed on the sensor substrate 13, and 16 is a housing that includes the sensor substrate 13 and houses an optical system. .

  FIG. 2 is a configuration diagram of an optical lens system installed in an array with a pitch of 6 mm mounted on the image reading apparatus according to Embodiment 1 of the present invention. Reference numeral 17 denotes a first lens 7 and a second lens 9 integrated with each other. Reference numeral 18 denotes a light-shielding plate for preventing light interference between the first lens 7 and the second lens 9 disposed in an array on the lens support 17. The lens cradle 17, the first lens 7, and the second lens 9 are made of acrylic resin, and a black light shielding material is applied except for the mirror surface of the lens. The lens cradle 17, the first lens 7 and the second lens 9 may be integrally formed with acrylic resin. In the figure, the same reference numerals as those in FIG. 1 denote the same or corresponding parts.

  FIG. 3 is a configuration diagram of the optical mirror system. The first mirror 6 and the second mirror 11 are continuously arranged in a strip shape so as to face each other with the aperture mirror 8 interposed therebetween, and the surface of the aperture mirror 8 is made of black resin or metal. Holes are provided in the thin plate and the openings 10 are discretely installed in an array at a pitch of 6 mm. In the figure, the same reference numerals as those in FIG. 1 denote the same or corresponding parts.

  FIG. 4 is a plan view of the image reading apparatus according to Embodiment 1 of the present invention, in which 19 is a light source unit for making light incident on the light guide 3, and 20 is an input / output interface connector for driving the image reading apparatus. is there.

  FIG. 5 is a plan view of the sensor board 13, and 19 a is a light source connection part that electrically connects the light source part 19 and the connector 20 of the sensor board 13.

  FIG. 6 is a plan view of the sensor IC 12. Reference numeral 21 denotes a light receiving unit in which an RGB filter composed of gelatin material made of red (R), green (G), and blue (B) is arranged on the light receiving surface for one pixel. (Cell) 22 is a photoelectric conversion / RGB shift register drive circuit that photoelectrically converts the light incident on the cell 21 for each RGB and holds the output, and 24 is a wire that inputs and outputs signals and power to the sensor IC 12. It is a bonding pad part.

  FIG. 7 is a view for explaining a light source portion including the light guide 3, 25 is a light scattering layer for uniformly irradiating light from the emitting portion 3 a of the light guide 3 in the main scanning direction, and 26 is a light guide. The electrode parts 27 and 27 installed at both ends of the light body 3 are light sources, each of which includes LED chips that emit red (R), green (G), and blue (B) wavelengths. As shown in FIG. 8, the electrode unit 26 is provided with an R light source (27R), a B light source (27B), and a G light source (27G). Further, when the light source 27 is installed at both ends of the light guide 3, the light scattering layer 25 is wide at the center in the main scanning direction, and when it is installed at one side, the light scattering layer 25 is widened away from the light source 27. The light emission from the part 3a is made uniform.

  Note that the optical wavelength of each RGB light source 27 substantially matches the wavelength of each RGB color of the RGB filter provided in the light receiving unit 21. 4-7, the same code | symbol as FIG. 1 shows the same or equivalent part.

  FIG. 9 is a block configuration diagram of the image reading apparatus according to the first embodiment, in which 30 is an amplifier that amplifies a signal photoelectrically converted by the sensor IC 12, and 31 is an analog that performs analog / digital conversion on the amplified photoelectric conversion output. A digital converter (A / D converter), 32 is a signal processing unit that processes digital output of each RGB color, 33 is a system interface that exchanges signals between the image reader (also called CIS) and the system side, and 34 is A RAM for storing image information of each color, 35 is a CPU, and 36 is a light source driving circuit.

  Next, the operation of the image reading apparatus according to Embodiment 1 of the present invention will be described. In FIG. 9, based on the system control signal (SYC) and the system clock signal (SCLK) signal from the system main body, the clock signal (CLK) of the signal processing IC (ASIC) 14 is synchronized with this via the system interface 33. A start signal (SI) is output to the sensor IC 12, and a continuous analog signal of each pixel (n) is output from the sensor IC 12 for each reading line (m) at the timing. In the example shown in FIG. 10, 7200 pixels are sequentially output as analog signals, and in the example shown in FIG. 11 divided outputs are output in units of 144 pixels.

  The analog signal amplified by the amplifier 30 is A / D converted by the A / D converter 31 and converted into a digital signal. After the A / D conversion, the signal output of each pixel (bit) is subjected to shading correction and all bit correction. Processing is performed by a correction circuit to be performed. In this correction, the correction data is read from the RAM 34 storing correction data obtained by uniformizing the data read in advance with a reference test chart such as a white original, and a digital signal corresponding to the A / D converted image information is processed. By doing. Such a series of operations is performed under the control of the CPU 35. This correction data is for correcting the sensitivity variation among the elements of the sensor IC 12 and the non-uniformity of the light sources 27.

  Next, the drive timing of the image reading apparatus according to the first embodiment will be described with reference to FIGS. 9 and 12, the ASIC 14 turns on the light source lighting signal (LC) in conjunction with the CPU 35, and in response to this, the light source driving circuit 36 supplies power to each of the light sources 27 for a predetermined time. Emits white light. The start signal (SI) in synchronization with the continuously driven CLK signal sequentially turns on the output of the shift register of each element (pixel) forming the RGB drive circuit of the sensor IC 12, and the corresponding switch group is SIG (SO). By sequentially opening and closing the line, RGB image information (image output) synchronized with CLK is obtained. This image output is an output of each image read and accumulated in the previous line. Note that CNT is a color / monochrome switching signal, and is normally at a high level in the color mode. BLK (blanking) time is set for each color reading section of one line, and exposure time setting is varied. Therefore, all SIG (SO) is released in the BLK section.

  Next, the image signal SIG (SO) output sequentially will be described with reference to FIG. FIG. 13 is a principle diagram for explaining the light path in the main scanning direction. The irradiation unit 5 varies with respect to the direction perpendicular to the transport surface depending on the thickness of the irradiation object 1. When the point light source is assumed on the surface of the irradiated object (original) 1 through the first mirror that reflects in the sub-scanning direction, the scattered light is collimated and reflected as a substantially parallel light beam. Incident on the first aspherical mirror. The light from each optical system arranged in an array is focused by apertures (windows) discretely installed at a pitch of 6 mm, and the light emitted from the windows is a light shielding plate 18 that prevents light interference for each array. Each light beam is incident on the sensor IC 12 through a lens provided with the image sensor, so that the image information is formed as an inverted image on the light receiving surface of the sensor IC 12. Accordingly, the image information formed on the light receiving portion (also referred to as a pixel) 21 of each sensor IC 12 is a reverse image with respect to the irradiated object 1 such as a document. As the SIG (SO) signal, analog signals are simultaneously output in three series for each RGB by a shift register sequential switching signal provided in the drive circuit of the sensor IC 12.

  FIG. 14 is a diagram for explaining rearrangement of the reverse image data of the A / D converted RGB signal. FIG. 14A shows a case where the data is rearranged every 144 bits. In FIG. 14A, each RGB (SO) signal is stored in each cell constituted by the shift register circuit after the data left-shifted by the shift register circuit is latched (LA), and then the write signal ( WR) sequentially, data rearranged as SIG (SO) from the first cell of the sensor IC 12 is stored in the RAM 34, and correction calculation processing is performed.

  FIG. 14B is an example in the case where a virtual bit (element) generated between the light receiving portions 21 arranged at the outermost position of the sensor IC 12 is required. The data of the virtual bit is the data at the outermost position. A data address is added as simple averaged data and sent to the RAM 34. In this case, the RAM 34 also stores data in which virtual bits are woven in advance, and correction calculation processing is performed. As shown in FIG. 1 of Japanese Patent Application Laid-Open No. 8-28966, the image data subjected to the correction calculation processing is transmitted through a system interface 33 by a color management system including data analysis, data restoration, and the like by a color conversion and color management engine. It is output as SIG (RGB) color data.

  FIG. 15 is a diagram for explaining the optical distance in the sub-scanning direction. One focal position of the first lens 7 is substantially coincident with the irradiating portion 5 of the irradiated object 1, and the other focal position is the aperture. It matches the mirror 8. Further, one focal position of the second lens 9 is coincident with the aperture mirror 8, and the other focal position is coincident with the light receiving surface. That is, there are relationships of L3 = L1 + L2, L4 = L5 + L6, and L3 = L4 + B. FIG. 16 embodies the path of light in the sub-scanning direction, and the optical distances L3 and L4 from the first lens 7 to the second lens 9 are substantially parallel light. The scattered light reflected from the first mirror 6 in the sub-scanning direction may be radiated in either direction as long as it is a mirror target, and the light receiving unit 21 installed on the light receiving surface also has an arbitrary value as long as L4 = L5 + L6 is satisfied. Location.

  FIG. 17 is an explanatory diagram of the light shielding plate 18 attached to the first lens 7 and the second lens 9 which are integrally configured. In FIG. 17A, reference numeral 17a denotes a groove (groove portion) of the lens receiving base 17 installed between the lenses arranged in an array. A light shielding plate 18 is inserted into the groove 17a to prevent light leakage mainly to the adjacent second lens 9. FIG. 17B is a partially enlarged view of the light shielding plate 18, and the surface of the light shielding plate 18 having a thickness of 0.3 mm made of a carbon glass material is subjected to sand blasting or etching treatment, and about 0 as shown in FIG. By performing a surface roughening of about 0.02 mmp-p, the reflection of unnecessary light incident on both ends of the second lens 9 in the main scanning direction and reflected by the light shielding plate 18 is completely absorbed. In addition, a black nitride film (ALN) material is vapor-deposited on an acrylic resin to roughen the surface, and if the reflectance is 15 to 20% even when black, the ghost phenomenon with respect to the generated image is reduced in hardware. It is possible.

  As described above, according to the image reading apparatus of the first embodiment, the aperture mirror that reflects the light from the first aspherical mirror, and the second aspherical mirror that receives the light from the aperture mirror and reflects it as convergent light. Is installed on one side in the sub-scanning direction, and the aperture mirror is installed on the other side in the sub-scanning direction. An image reading apparatus can be obtained.

  Further, since the RGB light emission color is used for the light source 27 and the RGB filter corresponding to the RGB light emission color of the light source 27 is used on the light receiving side, the surface of the black light-shielding plate 18 that absorbs light is further roughened. Compared with a light source having, it is possible to obtain high-quality image information with good image quality that matches the dropout color with no ghost in the image.

Embodiment 2. FIG.
Although the case where the light source is irradiated from both sides using the rod-shaped light guide 3 is described in the first embodiment, the case where the array type light source is used will be described in the second embodiment. FIG. 18 is a cross-sectional configuration diagram of the image reading apparatus according to the second embodiment. In FIG. 18, reference numeral 130 denotes a vertical light guide that propagates light, 130 a denotes an emission part of the light guide 130, and 140 denotes a slit that allows light to pass in the vicinity of the irradiation part 5, and is one of the transport paths of the irradiated object 1. A cover made of a plastic material that constitutes the part, 160 is a first mirror that reflects scattered light from the irradiation unit 5, and 170 is a concave first lens mirror (first lens) that receives the reflected light from the first mirror 160. , 180 is an aperture mirror that receives parallel light from the first lens 170, and 190 is a concave second lens mirror (second lens) that receives reflected light from the aperture mirror 180.

  Reference numeral 200 denotes a second mirror that receives and reflects light from the second lens 190, 201 a sensor substrate on which the sensor IC 12 and the light source 27 are placed in an array, and 202 a housing that includes the sensor substrate 201 and houses an optical system. , 202a is a part of the housing 200, a light guide 130 housing portion (holder), and 203 is a pulley (conveying pulley) for conveying the irradiated object 1. In the figure, the same reference numerals as those in FIG. 1 denote the same or corresponding parts.

  FIG. 19 is a plan view of an image reading apparatus according to Embodiment 2 of the present invention, and reference numeral 140a denotes a slit portion of a cover 140 provided in a reading area in the main scanning direction.

  FIG. 20 is a plan view of the sensor substrate 201. The light source 27 is composed of LED chips sequentially provided in RGB colors at the end of the sensor substrate 201 in the main scanning direction. The drive power supply for each RGB light source 27 is wired from the connector 20.

  FIG. 21 is a diagram for explaining the optical distance in the sub-scanning direction of the image reading apparatus according to Embodiment 2 of the present invention. One focal position of the first lens 170 is the top plate 2 position and the irradiation of the cover 140. It coincides with the center position with the body 1 side position, and the other focal position coincides with the aperture mirror 180. Further, one focal position of the second lens 190 coincides with the aperture mirror 180, and the other focal position coincides with the light receiving surface. That is, there are relationships of L3 = L1 + L2, L4 = L5 + L6, and L3 = L4 + B. In addition, the 1st mirror 160 and the 2nd mirror 200 are installed linearly with respect to the normal line of the conveyance surface of the to-be-irradiated body 1. FIG.

  FIG. 22 is an explanatory view of a light shielding plate 18 attached to the first lens 170 and the second lens 190 installed in the housing 202. In FIG. 22, 202 b is a groove (groove portion) installed on the housing 202 side between the second lenses 190 installed in an array. The light shielding plate 18 is inserted into the groove 202 b and the light to the adjacent second lens 190 is transmitted. Prevent leakage and contamination. As in Embodiment 1, the light shielding plate 18 is subjected to surface roughening by sandblasting or etching the surface of a 0.3 mm thick plate made of a carbon glass material. The first lens 170 and the second lens 190 are made of acrylic resin independently, and a black light-shielding material is applied except for the mirror surface of the lens and is directly bonded and fixed to the housing 202 with resin. Since the operation of the image reading apparatus according to the second embodiment is the same as that of the first embodiment, detailed description thereof is omitted.

  As described above, according to the image reading apparatus according to the second embodiment, the RGB light source is installed on the sensor substrate 201 and the vertical light guide 130 extending from the light receiving surface side to the vicinity of the irradiation unit 5 is used. Since a large number of LED chips 27 are arranged in 201 in 201, the illuminance in the irradiating unit 5 is greatly increased as compared with the first embodiment, and there is an advantage that a large effect is achieved in high-speed reading.

  In the second embodiment, the light guide 130 is one-sided with respect to the irradiation unit 5. However, the light guide 130 is further added to the housing 202 side facing the light guide 130, and the irradiation unit is applied to the reading surface. 5 may be irradiated with light from both sides.

Embodiment 3 FIG.
In the first and second embodiments, the RGB light sources are caused to emit light at the same time and the image information is read. In the third embodiment, a case where another LED light source is used will be described. Since the operation of the image reading apparatus according to the third embodiment is the same as that of the first embodiment, detailed description thereof is omitted.

  FIG. 23 is a diagram for explaining a light source portion including a light guide. In FIG. 23A, reference numeral 250 denotes light for uniformly irradiating light from the emitting portion 3a of the light guide 3 in the main scanning direction. A scattering layer, 260 is an electrode part installed at both ends of the light guide 3, 270 is a light source, and is composed of an LED chip that emits a purple wavelength of 405 nm or more.

  FIG. 23B is a partially enlarged view of the periphery of the electrode portion 260 of FIG. 23A. The light source portion of the electrode portion 260 reacts with the LED chip (V light source) 270 incorporated in the case and the V light source. And a transparent fluorescent resin 280 that emits fluorescence, a V-cut filter 290 that suppresses transmission of purple emission, and an electrode 300. The V light source 270 is composed of three LED chips at one end of the light guide 3 as in the first embodiment. In the figure, the same reference numerals as those in FIG. 1 denote the same or corresponding parts.

  FIG. 24 is a diagram for explaining a case where the V light sources 270 are arranged in an array on the sensor substrate 201, and the emitting part 130a is arranged in the vicinity of the irradiation part 5 by the vertical light guide 130. In FIG. 24, 202a is a part of the housing | casing 202, and is the light guide 130 accommodation part like Embodiment 2. In FIG. In the figure, the same reference numerals as those in FIGS. 18 and 23 denote the same or corresponding parts.

  FIG. 25 shows the relative output at each wavelength of the light emitted from the V-light source 270 of violet emission color and fluorescently emitted by the fluorescent resin 280. By inserting the V cut filter 290 into the light diffusion region of the V light source 270, the light receiving portion 21 of the sensor IC 12 is suppressed from receiving light of the violet emission wavelength, and the blue emission color is not greatly suppressed. The image information corresponding to each drop color of the RGB filter thus made can be received.

  In the third embodiment, a purple light emitting LED is used. However, by using a V-cut filter as a low-band wavelength cut filter 290 having a purple light emission color or less, a peak is generated around 475 nm necessary for image information of color expression. If the light emission wavelength is less than that of the blue light emission color, even if it is an ultraviolet (UV) light emitting LED in addition to the purple light emission color, the same effect as that of the purple light emission LED is obtained.

  From the above, according to the image reading apparatus according to the third embodiment, white light is obtained by using the fluorescence with a single wavelength light source, so that it is possible to reproduce a color image without using a plurality of wavelength light sources. In addition, since the RGB filter does not need to match the wavelength of the light source, various color filters can be mounted.

1..Subject to be irradiated (original) 2..Top plate 3..Light guide 3a..Ejecting unit 4..Transmitter 5..Irradiating unit 6..First mirror 7..First lens (first) Aspherical mirror)
8. Aperture mirror 9. Second lens (second aspherical mirror) 10. Opening 11 Second mirror 12. Sensor IC 13. Sensor substrate 14. Signal processing IC (ASIC) 15.・ Electronic parts 16 ・ ・ Housing 17 ・ ・ Lens base 17a ・ ・ Groove part 18 ・ ・ Light shielding plate 19 ・ ・ Light source part 19a ・ ・ Light source connection part 20 ・ ・ Connector 21 ・ ・ Light receiving part (cell pixel)
22.-Photoelectric conversion-RGB shift register drive circuit 24--W / B pad unit 25--Light scattering layer 26--Electrode unit 27--Light source (LED chip) 27R--R light source 27G--G light source 27B-- -B light source 30-Amplifier 31-A / D converter 32-Signal processing unit 33-System interface circuit 34-RAM (random access memory)
35..CPU 36..Light source driving circuit 130..Light guide 130a..Ejecting part 140..Cover 140a..Slit part 160..First mirror 170..First lens (first aspherical mirror)
180 .. Aperture mirror 190 .. Second lens (second aspherical mirror)
200..Second mirror 201..Sensor substrate 202..Case 202a..Holder (light guide housing portion) 202b..Groove portion 203..Pulley 250..Light scattering layer 260..Electrode portion 270..Light source (V light source)
280 ... Fluorescent resin 290 ... V cut filter (purple cut filter)
300 .. Electrode.

Claims (7)

  A light source for irradiating light to the irradiating portion of the document over the main scanning direction, a first mirror for entering scattered light reflected by the document and reflecting in the sub-scanning direction, and collimating the light from the first mirror And a concave first aspherical mirror that reflects as a substantially parallel light beam, and an aperture that reflects light from the first aspherical mirror through an opening that is shielded from light and selectively allows light to pass therethrough. A mirror, a concave second aspherical mirror that receives light from the aperture mirror and reflects it as convergent light, and an optical path of the light converged by the second aspherical mirror. A second mirror that reflects light in the vertical direction, a light receiving portion that receives light from the second mirror and forms an image corresponding to the light from the opening, and at least the first non-mirror. A spherical mirror and the second aspherical mirror; A housing that is disposed on one side in the sub-scanning direction and the aperture mirror is disposed on the other side in the sub-scanning direction, and an optical distance from the first aspherical mirror to the aperture mirror is An image reading apparatus, wherein the optical distance to the first mirror is longer than the optical distance from the first mirror to the first aspherical mirror.   The image reading apparatus according to claim 1, wherein the aperture mirror is installed at a focal position of the first aspherical mirror.   The image reading apparatus according to claim 1, wherein the aperture mirror is installed at a focal position of the second aspherical mirror.   The first aspherical mirror and the second aspherical mirror are integrated, the first aspherical mirror is installed on the irradiation unit side, and the second aspherical mirror is installed on the light receiving unit side. Item 4. The image reading apparatus according to any one of Items 1 to 3.   5. The image reading apparatus according to claim 1, wherein the first mirror and the second mirror are installed linearly with respect to the normal line of the transport surface of the irradiated object.   An RGB light source for irradiating light to the irradiating portion of the document over the main scanning direction, a first mirror for reflecting scattered light reflected by the document and reflecting in the sub-scanning direction, and light from the first mirror The light from the first aspherical mirror is reflected through a concave first aspherical mirror that is collimated and reflected as a substantially parallel light beam, and an opening that is shielded from light and selectively allows light to pass through. An aperture mirror, a concave second aspherical mirror that receives light from the aperture mirror and reflects it as convergent light, and an optical path of the light converged by the second aspherical mirror, A second mirror that reflects light in the vertical direction, and a light receiving area that receives light from the second mirror and forms an image corresponding to the light from the opening, respectively, corresponds to the optical wavelength of the RGB light source. Have RGB filter to An optical unit, and a housing in which at least the first aspherical mirror and the second aspherical mirror are installed on one side in the sub-scanning direction, and the aperture mirror is installed on the other side in the sub-scanning direction, The optical distance from the first aspherical mirror to the aperture mirror is longer than the optical distance from the irradiating unit to the first mirror and the optical distance from the first mirror to the first aspherical mirror. A characteristic image reading apparatus.   A fluorescent light source that irradiates fluorescence on the irradiating portion of the document over the main scanning direction, a first mirror that receives scattered light of light reflected by the document and reflects it in the sub-scanning direction, and light from the first mirror The light from the first aspherical mirror is reflected through a concave first aspherical mirror that is collimated and reflected as a substantially parallel light beam, and an opening that is shielded from light and selectively allows light to pass through. An aperture mirror, a concave second aspherical mirror that receives light from the aperture mirror and reflects it as convergent light, and an optical path of the light converged by the second aspherical mirror, A second mirror that reflects light in the vertical direction, and light from the second mirror is incident, and a light receiving region that forms an image corresponding to the light from the opening has a plurality of colors having a longer wavelength than blue. A light receiving section having a filter, and at least The first aspherical mirror and the second aspherical mirror are installed on one side in the sub-scanning direction, the aperture mirror is installed on the other side in the sub-scanning direction, and the light from the fluorescent light source and the document A low-pass filter that cuts a wavelength shorter than the blue wavelength in the passage path of the optical path, the optical distance from the first aspherical mirror to the aperture mirror is the optical distance from the irradiation unit to the first mirror, and An image reading apparatus having a longer optical distance from the first mirror to the first aspherical mirror.

Images