JP2012065149A - Image reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image reader for reducing a difference of a color tone generated between an image obtained by a manually placed document reading and an image obtained by a sheet-through document reading.SOLUTION: A platen glass 16 is installed in a body 12 and a document P is placed on a main face. A transport device 15 transports the document P. A platen glass 17 is arranged in the body 12 and the document P being transported by the transport device 15 passes through on the main face. A slider portion 18 is constituted to be movable below the platen glasses 16 and 17, and includes a light source device 27 irradiating the document P on the platen glass 16 or the document P on the platen glass 17. The slider portion 18 can vary a spectral characteristic of light with which the document P on the platen glass 16 is irradiated and that of light with which the document P on the platen glass 17 is irradiated.

Description

  The present invention relates to an image reading apparatus, and more particularly, an image reading apparatus capable of reading a document placed on a first transparent plate and further reading while conveying the document on a second transparent plate. About.

  2. Description of the Related Art Image reading apparatuses that can perform manual placement original reading and through original reading are widely used. Manual document reading is an operation of reading a document placed on a platen glass. “Through original reading” is an operation of reading an original through the platen glass by an ADF (Auto Document Feeder) mechanism. Such an image reading apparatus is provided with a platen glass for reading a manually placed document and a platen glass for reading a through document.

  By the way, the image reading apparatus has a problem that a color tone difference occurs between an image obtained by manual placement original reading and an image obtained by through-through original reading. More specifically, the platen glass for reading through documents is provided with an antifouling coating or a conductive coating so that the platen glass is not contaminated. Therefore, the relationship between the transmittance and wavelength of the platen glass for manual document reading (spectral transmittance) is different from the relationship between the transmittance and wavelength of the platen glass for through-document reading (spectral transmittance). ing. As a result, there is a difference in color tone between an image obtained by manual placement document reading and an image obtained by through document reading.

  As a conventional document reading device, for example, a color document reading device described in Patent Document 1 is known. In the color original reading apparatus, the thickness of the filter member of the color filter is changed in order to correct the spectral sensitivity distribution shift of the CCD color filter. However, Patent Document 1 does not include a description relating to reducing a difference in color tone that occurs between an image obtained by manual placement document reading and an image obtained by through document reading.

JP-A-11-136443

  Accordingly, an object of the present invention is to provide an image reading apparatus capable of reducing a difference in color tone generated between an image obtained by manual placement original reading and an image obtained by through document reading.

  An image reading apparatus according to an aspect of the present invention includes a main body, a first transparent plate that is provided on the main body and on which a document is placed, a transport unit that transports the document, and the main body And a second transparent plate through which a document conveyed by the conveying means passes on the main surface, and is movable below the first transparent plate and the second transparent plate. A slider portion including a light source device that irradiates light to the original on the first transparent plate or the original on the second transparent plate, and The slider portion can make a spectral characteristic of light radiated to the original on the first transparent plate different from a spectral characteristic of light radiated to the original on the second transparent plate. And

  According to the present invention, it is possible to reduce a difference in color tone generated between an image obtained by manual placement original reading and an image obtained by through-through original reading.

1 is a configuration diagram of an image reading apparatus according to a first embodiment of the present invention. 1 is a configuration diagram of an image reading apparatus according to a first embodiment of the present invention. It is a block diagram of the light source device of an image reading apparatus. It is the graph which showed the spectral transmittance | permeability of the platen glass with which platen glass, the conductive coating were given, and the platen glass with which antifouling coating and conductive coating were given. FIG. 5A and FIG. 5C are graphs showing the spectral characteristics of light reflected from the original and transmitted through the platen glass. FIG. 5B and FIG. 5D are graphs showing the spectral characteristics of the LED. FIG. 5E is a graph showing the spectral characteristics of the LED. It is a block diagram of the light source device which concerns on a 1st modification. It is a block diagram of the light source device which concerns on a 2nd modification. It is a block diagram of the image reading apparatus which concerns on the 2nd Embodiment of this invention. It is a block diagram of the image reading apparatus which concerns on the 2nd Embodiment of this invention. It is a block diagram of the image reading apparatus which concerns on the 3rd Embodiment of this invention. It is a block diagram of the image reading apparatus which concerns on the 3rd Embodiment of this invention.

(First embodiment)
Hereinafter, an image reading apparatus 10 according to a first embodiment of the present invention will be described with reference to the drawings. 1 and 2 are configuration diagrams of an image reading apparatus 10 according to the first embodiment of the present invention. FIG. 3 is a configuration diagram of the light source device 27 of the image reading device 10. Hereinafter, the vertical direction is defined as the z-axis direction, and the moving direction of the slider portions 18 and 20 is defined as the x-axis direction. A direction orthogonal to the x-axis direction and the z-axis direction is defined as the y-axis direction.

  As shown in FIG. 1, the image reading device 10 includes a main body 12, a document cover 14, a transport device 15, platen glasses 16 and 17, slider units 18 and 20, an imaging lens 22, an image sensor 24, and a control unit 50. ing.

  The main body 12 is a rectangular parallelepiped housing provided with a document cover 14, a transport device 15, platen glasses 16 and 17, slider portions 18 and 20, an imaging lens 22, and an image sensor 24. The platen glass 16 is a rectangular transparent plate attached to an opening provided on the positive side of the main body 12 in the z-axis direction. The document P is placed on the main surface of the platen glass 16 with the reading surface facing the negative direction in the z-axis direction. The platen glass 17 is a rectangular transparent plate attached to an opening provided on the positive side in the z-axis direction of the main body 12, and is located on the negative side in the x-axis direction than the platen glass 16. Yes.

  As shown in FIG. 1, the document cover 14 functions to bring the document P into close contact with the platen glass 16 by covering the document P.

  The transport device 15 transports the document P, and the transport device 15 includes trays 15a and 15b and a transport unit 15c. The document P is placed on the tray 15a with the reading surface facing the positive side in the z-axis direction. The transport unit 15c passes the document P on the tray 15a over the main surface of the platen glass 17 with the reading surface of the document P facing the negative side in the z-axis direction. Thereafter, the document P is discharged onto the tray 15b.

  As shown in FIGS. 1 and 2, the slider portion 18 is configured to be movable in the x-axis direction on the negative side of the platen glass 16, 17 in the z-axis direction, and includes a light source device 27 and a mirror 29. .

  The light source device 27 irradiates the original P on the platen glass 16 (see FIG. 1) or the original P on the platen glass 17 (see FIG. 2) from two directions. As shown in FIG. 3, the light source device 27 includes light guides 28 a and 28 b, LEDs 40 a and 40 b, substrates 42 a and 42 b, and a casing (combining means) 44.

  The LEDs 40a and 40b are semiconductor elements that emit light. Each of the substrates 42a and 42b incorporates a circuit for driving the LEDs 40a and 40b. As shown in FIG. 3, the substrates 42a and 42b are provided perpendicular to the y-axis direction. At this time, the board | substrate 42a is located in the positive direction side of the y-axis direction rather than the board | substrate 42b. The LED 40a is mounted on the main surface on the positive side in the y-axis direction of the substrate 42a, and the LED 40b is mounted on the main surface on the negative direction side in the y-axis direction of the substrate 42b. That is, LED40a, 40b is arrange | positioned so that light may be irradiated to an opposite direction.

  The housing 44 forms a container for housing the LEDs 40a, 40b and the substrates 42a, 42b, and has a mirror surface on the inner peripheral surface. The housing 44 reflects the light irradiated by the LEDs 40a and 40b on the inner peripheral surface, and generates light in which these lights are combined.

  The light guide 28a is a transparent resin member having a cylindrical shape extending in the y-axis direction. The end of the light guide 28 a on the negative side in the y-axis direction is attached to an opening provided in the housing 44. Thereby, the light generated by the housing 44 enters from the end of the light guide 28a on the negative direction side in the y-axis direction. The light guide 28a irradiates the original P with light output from the housing 44 by a prism formed on the surface thereof. The light irradiated by the light guide 28 a is diffusely reflected on the reading surface of the original P.

  The light guide 28b is a transparent resin member having a cylindrical shape extending in the y-axis direction. The light guide 28b is provided in parallel to the light guide 28a on the negative side of the light guide 28a in the x-axis direction. The end of the light guide 28 b on the negative side in the y-axis direction is attached to an opening provided in the housing 44. Thereby, the light generated by the housing 44 enters from the end of the light guide 28b on the negative direction side in the y-axis direction. The light guide 28b irradiates the document P with light output from the housing 44 by a prism formed on the surface thereof. The light irradiated by the light guide 28 b is diffusely reflected on the reading surface of the original P. With the above configuration, the light source device 27 irradiates the document P with light from two directions.

  As shown in FIG. 1, the mirror 29 reflects the light reflected from the original P toward the negative side in the x-axis direction.

  As shown in FIGS. 1 and 2, the slider portion 20 is configured to be movable in the x-axis direction on the negative direction side of the platen glass 16, 17 in the z-axis direction, and includes mirrors 30, 32. The mirror 30 reflects the light from the mirror 29 to the negative direction side in the z-axis direction. The mirror 32 reflects the light from the mirror 30 to the positive direction side in the x-axis direction.

  The imaging lens 22 forms an optical image obtained by the light from the mirror 32 on the image sensor 24. The image sensor 24 is a light receiving element that receives light reflected from the document P. Specifically, the imaging device 24 has a one-dimensional imaging region extending in the y-axis direction, and is a CCD camera or the like that scans an optical image formed by the imaging lens 22 and reads an image of the original P. It is a line sensor.

  The control unit 50 is constituted by a CPU, for example, and controls the operation of the image reading apparatus 10.

  As shown in FIG. 1, the image reading apparatus 10 as described above includes a manual document reading for reading a document placed on the platen glass 16, and a conveying device 15 on the platen glass 17 as shown in FIG. Thus, it is possible to perform through-document reading that allows the document P to pass through. The operation of the slider portions 18 and 20 when manual placement original reading and through original reading are performed will be described below.

  When manual placement original reading is performed, the original P is placed on the main surface of the platen glass 16. Then, the document P is pressed against the platen glass 16 by the document cover 14. When the document P is being read, the slider portion 18 is moved toward the positive side in the x-axis direction along the platen glass 16 by moving means such as a motor, a belt, and a pulley (not shown) as shown in FIG. And moved at a speed V.

  On the other hand, when the document P is being read, the slider portion 20 is moved by a moving means such as a motor, a belt, and a pulley (not shown) on the negative side in the z-axis direction of the platen glass 16 as shown in FIG. It is moved at a speed V / 2 toward the positive side in the axial direction. Thus, by moving the slider unit 20 at half the speed of the slider unit 18, the length of the light path between the reading surface of the document P and the image sensor 24 during the movement is kept constant. .

  When the through document reading is performed, the document P is transported by the transport device 15 and passes over the platen glass 17 as shown in FIG. As shown in FIG. 2, the slider portion 18 is stationary on the negative side of the platen glass 17 in the z-axis direction. The slider unit 20 is stationary on the negative side of the slider unit 20 in the x-axis direction.

  By the way, in the image reading apparatus 10, as will be described below, the spectral transmittance (relationship between transmittance and wavelength) of the platen glass 16 and the spectral transmittance (relationship between transmittance and wavelength) of the platen glass 17 are described. Is different. FIG. 4 is a graph showing the spectral transmittance of platen glass, platen glass with conductive coating, and platen glass with antifouling coating and conductive coating. The vertical axis indicates the transmittance, and the horizontal axis indicates the wavelength.

  As described above, the original P is read through the platen glass 16 in the manual original reading, and the original P is read through the platen glass 17 in the through original reading. The platen glass 17 for reading through documents is provided with an antifouling coating or a conductive coating so that the platen glass 17 is not contaminated. On the other hand, the platen glass 16 for manual placement original reading is not subjected to antifouling coating or conductive coating. Therefore, the spectral transmittance of the platen glass 16 and the spectral transmittance of the platen glass 17 are different. Specifically, as shown in FIG. 4, the spectral transmittance of the platen glass with antifouling coating or conductive coating is higher than the spectral transmittance of the platen glass without antifouling coating or conductive coating. Is also low. In particular, at a wavelength in the range of 350 nm to 450 nm (wavelength from the wavelength of blue light to the wavelength of green light), the spectral transmittance of the platen glass to which antifouling coating or conductive coating is applied is It is lower than the spectral transmittance of platen glass to which no conductive coating or the like is applied. Such a difference in spectral transmittance causes a difference in color tone between an image obtained by manual placement original reading and an image obtained by through original reading.

  In view of this, in the image reading apparatus 10, the slider unit 18 can make the spectral characteristics of the light irradiated on the original P on the platen glass 16 different from the spectral characteristics of the light irradiated on the original P on the platen glass 17. . The spectral characteristic of the light irradiated on the original P on the platen glass 17 has stronger intensity than the spectral characteristic of the light irradiated on the original P on the platen glass 16 at a wavelength in the range of 350 nm to 450 nm.

  In the image reading apparatus 10 according to the present embodiment, in order to obtain the spectral characteristics, the spectral characteristics of the light emitted from the LED 40a and the spectral characteristics of the light irradiated from the LED 40b are different. Then, when irradiating the document P on the platen glass 16 with light (that is, when reading a manually placed document), the control unit 50 irradiates only the LED 40 a with light and irradiates the document P on the platen glass 17 with light. Is irradiated (that is, in the case of through document reading), the LEDs 40a and 40b are irradiated with light. Hereinafter, description will be given with reference to the drawings.

  FIGS. 5A and 5C are graphs showing the spectral characteristics of light reflected by the original P and transmitted through the platen glasses 16 and 17, respectively. FIG. 5B and FIG. 5D are graphs showing the spectral characteristics of the LED 40a. FIG. 5E is a graph showing the spectral characteristics of the LED 40b. In FIG. 5, the vertical axis indicates the light intensity, and the horizontal axis indicates the wavelength.

  When irradiating the original P on the platen glass 16 with light, the control unit 50 turns on only the LED 40a. In this case, the light having the spectral characteristics shown in FIG. 5B is irradiated onto the original P through the platen glass 16 and diffusely reflected on the original P. Then, light diffusely reflected on the original P and then transmitted through the platen glass 16 has spectral characteristics shown in FIG.

  On the other hand, when irradiating the original P on the platen glass 17 with light, the control unit 50 turns on the LEDs 40a and 40b. LED40b irradiates the light of the wavelength of the range of 350 nm-450 nm, as shown in FIG.5 (e). Then, light having the spectral characteristics shown in FIGS. 5D and 5E is irradiated onto the original P through the platen glass 17 and diffusely reflected on the original P. Then, light diffusely reflected on the original P and then transmitted through the platen glass 16 has the spectral characteristics shown in FIG.

  Here, the spectral transmittance of the platen glass 17 is lower than the spectral transmittance of the platen glass 16 in a wavelength range of 350 nm to 450 nm. That is, the platen glass 17 is easier to absorb and reflect light having a wavelength in the range of 350 nm to 450 nm than the platen glass 16. Therefore, when irradiating light on the document P on the platen glass 17, the control unit 50 turns on the LED 40b that emits light having a wavelength in the range of 350 nm to 450 nm in addition to the LED 40a. Thereby, the difference between the light lost when transmitted through the platen glass 17 and the light lost when transmitted through the platen glass 16 can be compensated by the light emitted by the LED 40b. As a result, as shown in FIGS. 5A and 5C, the spectral characteristics of the light diffusely reflected on the original P and then transmitted through the platen glass 16, and the diffused reflection on the original P, and then the platen glass 17 It becomes possible to make close to the spectral characteristics of the light transmitted through. Accordingly, it is possible to reduce a difference in color tone that occurs between an image obtained by manual placement original reading and an image obtained by through-through original reading.

  Further, in the image reading apparatus 10 according to the present embodiment, the light irradiated by the LEDs 40a and 40b is combined in the housing 44 and then irradiated to the document P by the light guides 28a and 28b. Therefore, the spectral characteristics of the light irradiated by the light guides 28a and 28b are equal. As a result, the occurrence of color unevenness in the image obtained by reading the document P is suppressed.

  In the image reading apparatus 10 according to the present embodiment, the LEDs 40a and 40b are used as the light sources in the light source device 27. However, for example, two fluorescent tubes may be used as the light sources. In this case, the spectral characteristics of the light irradiated by the two fluorescent tubes may be different from the spectral characteristics of the light irradiated by the LEDs 40a and 40b.

(First modification)
The light source device 27a according to the first modification will be described below with reference to the drawings. FIG. 6 is a configuration diagram of a light source device 27a according to the first modification. In the light source device 27a, the same components as those of the light source device 27 are denoted by the same reference numerals. Therefore, the configuration of the light source device 27a will be described focusing on the differences from the light source device 27.

  The LEDs 40′a and 40′b of the light source device 27a irradiate light having the same spectral characteristics. The LED 40'a is provided closer to the light guides 28a and 28b than the LED 40'b. Thereby, most of the light irradiated by the LED 40'a is directly incident on the light guides 28a and 28b without being reflected by the inner peripheral surface of the housing 44a. On the other hand, most of the light emitted by the LED 40′b is reflected by the inner peripheral surface of the housing 44a and then enters the light guides 28a and 28b.

  The inner peripheral surface of the housing 44a reflects light having a wavelength in the range of 350 nm to 450 nm with a higher reflectance than light having a wavelength outside the range of 350 nm to 450 nm. Specifically, the inner peripheral surface of the housing 44a is configured such that a coating that absorbs light having a wavelength outside the range of 350 nm to 450 nm is applied on the mirror surface. Accordingly, light having a wavelength in the range of 350 nm to 450 nm is transmitted through the coating, reflected by the mirror surface, transmitted through the coating again, and is incident on the light guides 28a and 28b. On the other hand, light having a wavelength outside the range of 350 nm to 450 nm is absorbed by the coating, and therefore hardly enters the light guides 28a and 28b.

  In the image reading apparatus 1 provided with the light source device 27a as described above, when the document P on the platen glass 16 is irradiated with light, the control unit 50 turns on only the LED 40'a. Most of the light emitted by the LED 40'a is directly incident on the light guides 28a and 28b without being reflected by the inner peripheral surface of the housing 44a. On the other hand, when the original P on the platen glass 17 is irradiated with light, the control unit 50 turns on the LEDs 40'a and 40'b. Most of the light emitted by the LED 40'b is reflected by the inner peripheral surface of the housing 44a and then enters the light guides 28a and 28b. Therefore, light having a wavelength in the range of 350 nm to 450 nm is incident on the light guides 28a and 28b. Thereby, the difference between the light lost when transmitted through the platen glass 17 and the light lost when transmitted through the platen glass 16 can be compensated by the light irradiated by the LED 40 ′ b and reflected by the housing 44 a. As a result, it is possible to make the spectral characteristics of the light transmitted through the platen glass 16 after being diffusely reflected on the original P and the spectral characteristics of the light transmitted after being diffusely reflected on the original P and transmitted through the platen glass 17 closer. Accordingly, it is possible to reduce a difference in color tone that occurs between an image obtained by manual placement original reading and an image obtained by through-through original reading.

(Second modification)
The light source device 27b according to the second modification will be described below with reference to the drawings. FIG. 7 is a configuration diagram of a light source device 27b according to a second modification. In the light source device 27b, the same reference numerals are given to the same components as those of the light source devices 27 and 27a. Therefore, the configuration of the light source device 27b will be described focusing on differences from the light source devices 27 and 27a.

  The LEDs 40′a and 40′b of the light source device 27a irradiate light having the same spectral characteristics. The LED 40'a is provided closer to the light guides 28a and 28b than the LED 40'b. Thereby, most of the light irradiated by the LED 40'a is directly incident on the light guides 28a and 28b without being reflected by the inner peripheral surface of the housing 44a. On the other hand, most of the light emitted by the LED 40′b is reflected by the inner peripheral surface of the housing 44a and then enters the light guides 28a and 28b.

  The inner peripheral surface of the housing 44 reflects light having a wavelength in the range of 350 nm to 450 nm with a higher reflectance than light having a wavelength outside the range of 350 nm to 450 nm. Specifically, light having a wavelength in the range of 350 nm to 450 nm is reflected on the inner peripheral surface of the housing 44 and facing the LED 40 ′ b, and light having a wavelength outside the range of 350 nm to 450 nm. A half-mirror coating 45 that passes through is provided. Thereby, light having a wavelength in the range of 350 nm to 450 nm is reflected by the coating 45 and enters the light guides 28a and 28b. On the other hand, light having a wavelength outside the range of 350 nm to 450 nm passes through the coating 45 and is absorbed by the housing 44, so that it hardly enters the light guides 28a and 28b.

  In the image reading apparatus 10 provided with the light source device 27b as described above, as with the image reading apparatus 10 provided with the light source device 27a, an image obtained by manual placement original reading and an image obtained by through-through original reading The difference in color tone generated between the two can be reduced.

(Second Embodiment)
Next, an image reading apparatus 10a according to a second embodiment will be described with reference to the drawings. 8 and 9 are configuration diagrams of an image reading apparatus 10a according to the second embodiment of the present invention. In the image reading device 10a, the same components as those in the image reading device 10 are denoted by the same reference numerals. Therefore, hereinafter, the image reading device 10a will be described focusing on differences from the image reading device 10.

  In the image reading device 10a, the light source device 27c has a fluorescent tube 41 and a mirror 52, as shown in FIGS. As shown in FIG. 8, the fluorescent tube 41 irradiates the original P and the mirror 52 with light. The mirror 52 reflects the light emitted from the fluorescent tube 41 and irradiates the original P on the platen glass 16. Thereby, the fluorescent tube 41 and the mirror 52 irradiate the original P with light from two directions when irradiating the original P on the platen glass 16 with light (that is, when performing manual placement original reading).

  In the image reading apparatus 10a, as shown in FIGS. 8 and 9, a mirror 54 is provided on the negative side of the platen glass 17 in the z-axis direction. As shown in FIG. 9, the mirror 54 is positioned in the slider portion 18 when the light source 27 c irradiates light on the original P on the platen glass 17 (that is, when reading through originals). This is a reflecting member that reflects a part of the light toward the original P on the platen glass 17. The mirror 54 reflects light having a wavelength in the range of 350 nm to 450 nm with a higher reflectance than light having a wavelength outside the range of 350 nm to 450 nm. At this time, as shown in FIG. 9, the mirror 52 moves to the negative direction side in the z-axis direction so as not to reflect the light irradiated by the fluorescent tube 41. Thereby, the fluorescent tube 41 and the mirror 54 irradiate the original P with light from two directions when irradiating the original P on the platen glass 16 with light (that is, when performing manual placement original reading).

  In the image reading apparatus 10a, the mirror 54 reflects light having a wavelength in the range of 350 nm to 450 nm with a higher reflectance than light having a wavelength outside the range of 350 nm to 450 nm. Therefore, the ratio of light having a wavelength in the range of 350 nm to 450 nm included in the light reflected by the mirror 54 is higher than the ratio of light having a wavelength in the range of 350 nm to 450 nm included in the light reflected by the mirror 52. Therefore, the ratio of light having a wavelength in the range of 350 nm to 450 nm included in the light irradiated on the original P on the platen glass 17 by the slider 18 is included in the light irradiated on the original P on the platen glass 16 by the slider 18. The ratio of light having a wavelength in the range of 350 nm to 450 nm is larger. As a result, the difference between the light having a wavelength in the range of 350 nm to 450 nm that is lost when transmitted through the platen glass 17 and the light having a wavelength in the range of 350 nm to 450 nm that is lost when transmitted through the platen glass 16 is reflected by the light reflected by the mirror 54. Can be supplemented. As a result, it is possible to make the spectral characteristics of the light transmitted through the platen glass 16 after being diffusely reflected on the original P and the spectral characteristics of the light transmitted after being diffusely reflected on the original P and transmitted through the platen glass 17 closer. Accordingly, it is possible to reduce a difference in color tone that occurs between an image obtained by manual placement original reading and an image obtained by through-through original reading.

(Third embodiment)
Next, an image reading apparatus 10b according to a third embodiment will be described with reference to the drawings. 10 and 11 are configuration diagrams of an image reading apparatus 10b according to the third embodiment of the present invention. In the image reading device 10b, the same components as those in the image reading device 10a are denoted by the same reference numerals. Therefore, hereinafter, the image reading device 10b will be described focusing on differences from the image reading device 10a.

  In the image reading device 10b, the light source device 27c includes mirrors 52 and 54. The functions of the mirrors 52 and 54 are the same as the mirrors 52 and 54 of the image reading apparatus 10a. However, as shown in FIGS. 8 and 9, the mirrors 52 and 54 can move (more specifically, rotate) within the slider portion 18. Therefore, the slider unit 18 includes a moving mechanism (not shown) for moving the mirrors 52 and 54.

  More specifically, when irradiating light on the original P on the platen glass 16 (that is, when performing manual placement original reading), the mirror 52 is irradiated with light emitted from the fluorescent tube 41 as shown in FIG. Is reflected to irradiate the original P. At this time, the moving mechanism moves the mirror 54 to the negative side in the z-axis direction of the mirror 52 so that the light reflected by the mirror 54 does not irradiate the original P on the platen glass 16.

  On the other hand, when the original P on the platen glass 17 is irradiated with light (that is, when through-original reading is performed), the mirror 54 irradiates a part of the light irradiated by the fluorescent tube 41 as shown in FIG. Reflected and irradiated to the original P. At this time, the moving mechanism moves the mirror 52 to the negative side in the x-axis direction of the mirror 54 so that the light reflected by the mirror 52 does not irradiate the original P on the platen glass 16.

  Also in the image reading apparatus 10b as described above, as in the image reading apparatus 10a, it is possible to reduce a difference in color tone that occurs between an image obtained by manual placement document reading and an image obtained by through document reading. .

  INDUSTRIAL APPLICABILITY The present invention is useful for an image reading apparatus, and is particularly excellent in that a difference in color tone generated between an image obtained by manual placement original reading and an image obtained by through-through original reading can be reduced. .

10, 10a, 10b Image reading device 12 Main body 14 Document cover 15 Transport device 16, 17 Platen glass 18, 20 Slider portion 27, 27a, 27b Light source device 40a, 40b, 40′a, 40′b LED
41 Fluorescent tube 44, 44a Housing 45 Coating 50 Control unit 52, 54 Mirror

Claims (12)

The body,
A first transparent plate provided on the main body and on which a document is placed on a main surface;
Conveying means for conveying an original;
A second transparent plate provided on the main body and through which a document being conveyed by the conveying means passes on a main surface;
A slider portion configured to be movable below the first transparent plate and the second transparent plate, the original on the first transparent plate or the original on the second transparent plate A slider portion including a light source device for irradiating light to
With
The slider portion can make a spectral characteristic of light radiated to the original on the first transparent plate different from a spectral characteristic of light radiated to the original on the second transparent plate;
An image reading apparatus characterized by the above. The spectral characteristic of the light irradiated on the original on the second transparent plate has a stronger intensity at a wavelength within a predetermined range than the spectral characteristic of the light irradiated on the original on the first transparent plate. That
The image reading apparatus according to claim 1. The wavelength of the predetermined range is a wavelength from a wavelength of blue light to a wavelength of green light,
The image reading apparatus according to claim 2. The light source device
A first light source;
A second light source for irradiating light having spectral characteristics different from the spectral characteristics of the light emitted by the first light source;
Have
The image reading device includes:
When irradiating light on the original on the first transparent plate, only the first light source is irradiated with light, and when irradiating the original on the second transparent plate with light, A controller that irradiates light to the first light source and the second light source;
In addition,
The image reading apparatus according to claim 1, wherein: The light source device
Combining means for combining the light emitted from the first light source and the light emitted from the second light source;
A light guide that irradiates the original on the first transparent plate or the original on the second transparent plate with light output from the combining means;
Further having
The image reading apparatus according to claim 4. The second light source emits light having a wavelength between a wavelength of blue light and a wavelength of green light;
The image reading apparatus according to claim 4, wherein: The light source device
A first light source;
A second light source;
By forming a container that accommodates the first light source and the second light source, and reflecting the light irradiated by the first light source and the light irradiated by the second light source on the inner peripheral surface A synthesis means to synthesize,
A light guide that irradiates the original on the first transparent plate or the original on the second transparent plate with light output from the combining means;
Have
The image reading device includes:
When irradiating light on the original on the first transparent plate, only the first light source is irradiated with light, and when irradiating the original on the second transparent plate with light, A controller that irradiates light to the first light source and the second light source;
In addition,
The first light source is provided closer to the light guide than the second light source,
The combining means reflects light having a wavelength in a predetermined range with a higher reflectance than light having a wavelength outside the predetermined range;
The image reading apparatus according to claim 1, wherein: The image reading device includes:
A reflecting member that reflects a part of the light emitted by the light source device toward the original on the second transparent plate, wherein light having a wavelength in a predetermined range is higher than light having a wavelength outside the predetermined range Reflective member that reflects with reflectivity,
More
The image reading apparatus according to claim 1, wherein: The light source device
A light source that emits light;
A reflecting member that reflects a part of light emitted from the light source toward the original on the second transparent plate, and reflects light having a wavelength in a predetermined range higher than light having a wavelength outside the predetermined range; A reflective member that reflects at a rate;
Further having
The image reading apparatus according to claim 1, wherein: The light source device
When irradiating the original on the first transparent plate with light, the reflective member is moved so that the light reflected by the reflective member does not irradiate the original on the first transparent plate. The transportation means
In addition,
The image reading apparatus according to claim 9. The spectral transmittance of the first transparent plate is different from the spectral transmittance of the second transparent plate;
The image reading apparatus according to claim 1, wherein: The spectral transmittance of the second transparent plate is lower than the spectral transmittance of the first transparent plate at a predetermined wavelength range,
The image reading apparatus according to claim 11.

Images