JP6398374B2 - Image inspection apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to an image inspection apparatus that reads an image on a recording sheet and inspects an image formed on the recording sheet, and an image forming apparatus including the image inspection apparatus. The present invention relates to an image inspection apparatus and an image forming apparatus capable of reading glossiness of recording paper.

  2. Description of the Related Art In recent years, an image forming apparatus that is provided with an image inspection apparatus that reads an image again from a printed recording sheet and inspects the print state has been widely used because of a demand for high reproducibility in an image after printing. The image inspection apparatus has a configuration similar to that of an image reading apparatus that reads an image of a document, thereby reading an image on a recording sheet after printing. By the way, an image reading apparatus has been proposed that can detect the gloss and color of an image of a document by utilizing a difference in optical path between regular reflection light and diffuse reflection light (Patent Document 1 and Patent Document 2). reference).

  The image reading device (imaging device) disclosed in Patent Document 1 is provided with means for selectively blocking the optical path of specularly reflected light from an original and the light of diffusely reflected light from the original. Only one of the reflected lights is incident on the line sensor (solid-state imaging device). On the other hand, the image reading apparatus disclosed in Patent Document 2 is provided with a mechanism for combining an optical system for forming an optical path of specularly reflected light with an optical system that constitutes an optical path of diffusely reflected light, so that the reading position of the document On the other hand, by sliding the mechanism, only one of the regular reflection light and the diffuse reflection light is made incident on the image sensor (solid-state imaging device).

JP 2006-279228 A JP 2010-245918 A

  As described above, each of the image reading devices disclosed in Patent Document 1 and Patent Document 2 selects one of the optical paths of regular reflection light and diffuse reflection light, and reads the gloss or color of the image. . For this reason, the image reading apparatuses of Patent Document 1 and Patent Document 2 need to provide an optical system suitable for each optical path of regular reflection light and diffuse reflection light, and to provide a mechanism for selecting each optical system. The configuration becomes complicated. Further, since the image reading apparatuses of Patent Document 1 and Patent Document 2 are not configured to read the color and gloss of the image at a time, in order to read the color and gloss of the image, two reading operations are performed on one original. It was necessary to do it once.

  In view of such a problem, an object of the present invention is to provide an image inspection apparatus and an image forming apparatus that can read the color and gloss of an image with a single reading operation and can simplify the structure thereof. And

In order to achieve the above object, an image inspection apparatus according to the present invention includes a light source for irradiating light on an image formed on a recording paper, and an optical path for allowing specularly reflected light from the light source to pass on the recording paper. In an image inspection apparatus comprising an optical system that configures and a solid-state imaging device that receives light guided by the optical system, the image inspection apparatus is disposed on an optical path from the light source to the recording paper, and emits light emitted from the light source. A first polarizer that transmits light linearly polarized in a predetermined polarization direction toward the recording paper, and a polarization direction of light received by the solid-state imaging device, provided as part of the optical system. A solid-state imaging device comprising: a second polarizer for regulating; a plurality of lines arranged in a second direction orthogonal to the first direction, line sensors each having a plurality of pixels arranged in a first direction. , The second polarizer from the recording paper Which has a gloss measurement filters and color measurement filter for blocking specular reflection light is transmitted through the specular reflected light, the every pixel constituting the solid-state imaging device, said measuring a color filter of the gloss measurement filter Any one of them is arranged, and the color image data and the glossy image data of the image on the recording paper are output simultaneously while passing one recording paper.

  In this image inspection apparatus, the gloss measurement filter may be arranged at predetermined pixel positions along the first direction with the second polarizer. In the second polarizer, at least one gloss measurement filter may be disposed at all pixel positions adjacent in the second direction. Furthermore, the second polarizer may be configured such that at least one gloss measurement filter is disposed at all pixel positions along the first direction.

  In the image inspection apparatus, the gloss measurement filter and the color measurement filter may be alternately arranged along the first direction in the second polarizer.

In each of the above image inspection apparatuses, the gloss measurement filter may be configured to transmit all reflected light. Further, the gloss measurement filter may be a neutral density filter that attenuates the amount of transmitted light.

In each of the above image inspection apparatuses, the specular reflection light can be transmitted by intersecting the transmission axis direction of the gloss measurement filter with the polarization direction of the specular reflection light at an angle smaller than 90 °. it can. At this time, the transmission axis direction of the gloss measurement filter may be the same as the polarization direction of the regular reflection light.

On the other hand, in each of the image inspection apparatuses described above, the transmission axis direction of the colorimetric filter is perpendicular to the polarization direction of the regular reflection light, so that the regular reflection light is shielded and only diffuse reflection light is present. Can be transmitted.

In the above image inspection apparatus, the second polarizer is composed of a thin film finely processed into a porous shape, and the thin film portion functions as the colorimetric filter , while the through hole portion of the thin film is The filter may function as the gloss measurement filter .

  In the above image inspection apparatus, the direction of light irradiated from the light source to the recording paper through the first polarizer may be 45 ° or less with respect to the normal line of the image inspection surface of the recording paper. I do not care. Further, the light source may be arranged so as to image the specularly reflected light from the recording paper at all pixels of the solid-state imaging device.

  The image forming apparatus according to the present embodiment includes any one of the above-described image inspection apparatuses, and thereby obtains color image data and glossy image data at a time for a printed recording paper image. can do.

According to the present invention, since the second polarizer is configured to have both a colorimetric filter that blocks specularly reflected light and a gloss measuring filter that transmits specularly reflected light, the color of the image formed on the recording paper In order to measure gloss, it is not necessary to perform the reading operation on the recording paper twice. Therefore, unlike the prior art, it is not necessary to install two image inspection devices in the image forming apparatus in order to measure the color and gloss of the image formed on the recording paper, and the image forming apparatus can only be miniaturized. In addition, the time required for measuring each of color and gloss can be shortened, and the conveyance of the recording paper can be simplified. Further, in the second polarizer, the color measurement filter and the gloss measurement filter are arranged in a dispersed manner along the arrangement direction of the pixels of the solid-state imaging device, so that the resolutions of the color image data and the gloss image data are lowered. Therefore, the measurement of color and gloss can be performed with high accuracy.

FIG. 1 is a schematic configuration diagram showing an internal configuration of an image forming apparatus which is a basic configuration of the present invention. FIG. 2 is a block diagram illustrating a schematic configuration of an image inspection apparatus in the image forming apparatus illustrated in FIG. 1. These are the figures which show the relationship of the transmission axis direction of each of 1st and 2nd polarizer, Comprising: (a)-(c) is a figure which shows the relationship with the transmission axis direction of the filter for glossiness measurement, (d ) Is a diagram showing the relationship with the transmission axis direction of the colorimetric filter. FIG. 2 is a schematic diagram showing a part of a configuration of a control device in the image forming apparatus of FIG. 1. These are the schematic diagrams which show the structure of the solid-state image sensor of the image inspection apparatus in the image forming apparatus of the 1st Embodiment of this invention. These are the schematic diagrams which show the structure of the 2nd polarizer of the image inspection apparatus in the image forming apparatus of the 1st Embodiment of this invention. These are the schematic diagrams which show another structure of the 2nd polarizer of the image inspection apparatus in 1st Embodiment. These are the schematic diagrams which show another structure of the 2nd polarizer of the image inspection apparatus in 1st Embodiment. These are the schematic diagrams which show another structure of the 2nd polarizer of the image inspection apparatus in 1st Embodiment. These are the schematic which shows the structure of the solid-state image sensor of another example used as a different pixel row | line in 1st Embodiment. These are the schematic diagrams which show the structure of the 2nd polarizer corresponding to the solid-state image sensor of the structure of FIG. 10 in 1st Embodiment. These are the schematic diagrams which show the structure of the solid-state image sensor of the image inspection apparatus in the image forming apparatus of the 2nd Embodiment of this invention. These are the schematic diagrams which show the structure of the 2nd polarizer of the image inspection apparatus in the image forming apparatus of the 2nd Embodiment of this invention. These are the schematic diagrams which show the structure of the 2nd polarizer of the image inspection apparatus in the image forming apparatus of the 3rd Embodiment of this invention. These are the schematic diagrams which show the structure which becomes another example of the 2nd polarizer in the image forming apparatus of 3rd Embodiment. These are the schematic diagrams which show the structure of the 2nd polarizer of the image inspection apparatus in the image forming apparatus of the 4th Embodiment of this invention.

<Basic Configuration in Embodiment for Implementing the Present Invention>
Hereinafter, a basic configuration in an embodiment of the present invention will be described with reference to the drawings. In the following drawings, the same reference numerals are given to the same parts or corresponding parts. In addition, this basic configuration describes a configuration common to the configurations in the following embodiments. The image forming apparatus according to the present invention, including the following embodiments, may be any apparatus provided with both an image reading mechanism and an image inspection mechanism. For example, a copying machine, a printer or a multifunction machine having a copying function is available. It does not matter.

1. Configuration of Image Forming Apparatus The configuration of the image forming apparatus 1 will be described with reference to FIG. FIG. 1 is a schematic configuration diagram showing an internal configuration of the image forming apparatus 1.

  An image forming apparatus 1 shown in FIG. 1 stores an image reading apparatus 2 that reads an image from a document and a recording paper 10 for printing an image, and feeds the recording paper 10 into the image forming apparatus 1. The mechanism 3, the image forming device 4 that transfers the toner image to the recording paper 10 based on the original image data read by the image reading device 2, and the toner image transferred to the recording paper 10 by the image forming device 4 The fixing device 5 for fixing, the image inspection device 6 for inspecting the printing state of the recording paper 10 on which the toner image is fixed by the fixing device 5, and the recording paper 10 after printing inspected by the image inspection device 6 A paper discharge mechanism 7 for discharging the paper.

  The image reading apparatus 2 forms an image on the solid-state imaging device 22, a light source 21 that irradiates light on the document, a solid-state image sensor 22 that receives reflected light from the document and converts it into an electrical signal, and the reflected light from the document. The imaging lens 23, the original glass plate 24 on which the original is placed, the reflecting mirror 25 that reflects the light from the light source 21 and irradiates the surface of the original, and the reflected light from the original is guided to the imaging lens 23. The reflectors 26A to 26C and a reference plate 27 for generating a correction value for shading correction are provided.

  The imaging lens 23 and the solid-state imaging device 22 each have a plurality of elements in a direction (corresponding to “main scanning direction”) perpendicular to the document reading direction (corresponding to “sub-scanning direction”). It consists of a group of elements arranged for each. Further, in the solid-state imaging device 22, since a primary color or complementary color filter is installed on the light receiving surface of each pixel, the light of the light transmitted through the color filter is received by each pixel device, so Read the image as a color image. Further, the light source 21 and the reflecting mirrors 25 and 26A are provided in the first slider portion 211, and the reflecting mirrors 26B and 26C are provided in the second slider portion 212. The first and second slider parts 211 and 212 are simultaneously moved in the sub-scanning direction by a moving mechanism (not shown) such as a rail and a motor, so that the sub-scanning direction of the original placed on the surface of the original glass plate 24 is increased. Reading to is performed.

  In the image reading apparatus 2 configured as described above, when reading an image of a document, the document is placed on a document glass plate 24 of a document placing table, or an automatic document feeder (ADF: Auto Document Feeder). ) To the original glass plate 24. At this time, when the irradiation light from the light source 21 and the reflected light from the reflecting mirror 25 are irradiated to the reading position of the document, the reflected light from the document with respect to this irradiation light is incident on the reflecting mirror 26A. Then, the reflected light from the reflecting mirror 26A is sequentially reflected by the reflecting mirrors 26B and 26C, guided to the imaging lens 23, and the reflected light from the original is transmitted through the imaging lens 23, and the solid-state imaging device 22 takes an image. The image is formed on the area. The solid-state imaging device 22 outputs an electric signal corresponding to the amount of received light for each line at a constant interval in accordance with the reading width along the sub-scanning direction, so that a two-dimensional original image based on the image on the original is obtained. Data is generated.

  Further, the image reading device 2 moves the first slider portion 211 and the second slider portion 212 to move the first slider portion 211 to a position directly below the reference plate 27 before performing the image reading operation of the document. The reference plate 27 is read. Thereby, the correction value for carrying out the shading correction | amendment of the output value of the electric signal output from the solid-state image sensor 22 to a main scanning direction is generable. Therefore, by performing shading correction based on this correction value for the electrical signal output from the solid-state image pickup device 22, variation in the amount of light in the main scanning direction by the light source 21 can be suppressed in the generated document image data.

  As shown in FIG. 1, the paper feed mechanism 3 includes a paper feed cassette 31 that stores a recording paper 10 on which an image is printed, a paper feed roller pair 32 that takes out the recording paper 10 stored in the paper feed cassette 31, and Is provided. Further, on the downstream side of the paper feed mechanism 3, a transport roller pair 33 for transporting the recording paper 10 fed from the paper feed cassette 31 to the recording paper transport path by the paper feed roller pair 32 to the image transfer mechanism 4 is provided. ing. The recording paper transport path represents a transport path from the paper feed cassette 31 to the paper discharge tray 72 along which the recording paper 10 on which an image is printed by the image forming mechanism is transported. The sheet feeding mechanism 3 configured in this manner takes out the recording sheets 10 stored in the sheet feeding cassette 31 one by one by the rotation of the pair of sheet feeding rollers 32 and supplies the recording sheets 10 to the recording sheet conveyance path. Then, the recording paper 10 discharged from the paper feeding cassette 31 is conveyed to the image forming device 4 by the rotation of the conveying roller 33 installed on the downstream side of the paper feeding mechanism 3 along the conveying direction of the recording paper 10. The

  The image forming device 4 is carried on the photosensitive drums 41 to 44 on which electrostatic latent images of each color of Y (Yellow) M (Magenta) C (Cyan) K (Key tone) are formed, and the photosensitive drums 41 to 44, respectively. Further, an intermediate transfer unit 45 to which toner of each color of YMCK is transferred, and a secondary transfer roller 46 that transfers the toner transferred to the intermediate transfer unit 45 to the recording paper 10 are provided. At this time, although not shown, each of the photosensitive drums 41 to 44 is provided with a charger for charging the photosensitive drums 41 to 44 by corona discharge or the like, and a laser beam or the like to the charged photosensitive drums 41 to 44. An exposure device that forms an electrostatic latent image by irradiation, a developing device that charges the YMCK toners by stirring and adheres them to the photosensitive drums 41 to 44, and the photosensitive drums 41 to 44 after being transferred to the intermediate transfer unit 45. And a cleaning member for removing the toner remaining on the toner.

  The intermediate transfer unit 45 also includes an intermediate transfer belt 451 to which toner of each color of YMCK is transferred from the photosensitive drums 41 to 44, a driving roller 452 and a driven roller 453 for rotating the intermediate transfer belt 451, and photosensitive drums 41 to 44, respectively. Are provided with primary transfer rollers 454 to 457 installed at positions facing each other with the intermediate transfer belt 451 interposed therebetween. Further, the intermediate transfer unit 45 includes a cleaning member (not shown) for removing toner remaining on the intermediate transfer belt 451 without being transferred to the recording paper 10 from the surface of the intermediate transfer belt 451. The secondary transfer roller 46 is installed at a position facing the driving roller 452 with the intermediate transfer belt 451 interposed therebetween.

  In the image forming apparatus 4 configured as described above, the photosensitive drums 41 to 44 have electrostatic latent images of each color of YMCK on the surfaces of the photosensitive drums 41 to 44 based on the document image data acquired by the image reading mechanism 2. Is formed, the charged YMCK color toners are carried on the electrostatic latent images of the photosensitive drums 41 to 44, respectively. In the intermediate transfer unit 45, the intermediate transfer belt 451 is rotated by the driving roller 452, and the toner images of each color of YMCK carried on the photosensitive drums 41 to 44 are primary transfer rollers 454 to 457 to which a predetermined potential is applied. Is transferred to the intermediate transfer belt 451 by the electrostatic force.

  At this time, the intermediate transfer belt 451 sequentially transfers the toner images of the respective colors from the photosensitive drums 41 to 44 in the order of YMCK by the portions where the toner images to be transferred to the recording paper 10 are sequentially contacted with the photosensitive drums 41 to 44. Is done. Further, YMCK toner images on the surfaces of the photosensitive drums 41 to 44 are formed in the order of the photosensitive drums 41 to 44 in accordance with the timing of transferring the toner to the intermediate transfer belt 451.

  The toner image formed by transferring the YMCK color toners onto the surface of the intermediate transfer belt 451 moves to a position where the surface of the intermediate transfer belt 451 on which the toner image is formed is opposed to the secondary transfer roller 46. Then, the image is transferred to the recording paper 10 sandwiched between the intermediate transfer belt 451 and the secondary transfer roller 46. The transfer of the toner image onto the recording paper 10 is realized by the charged toner of each color being attracted to the secondary transfer roller 46 by the voltage applied to the secondary transfer roller 46. The recording paper 10 onto which the toner image is transferred is not only conveyed from the paper feeding mechanism 3 to the secondary transfer roller 46, but also includes a recording paper reversing mechanism (not shown) for reversing the recording paper 10. In the case where it is provided on the downstream side of 5, it is conveyed from the secondary transfer roller 46 by the recording paper reversing mechanism.

  The fixing device 5 includes a heating roller 51 including a halogen lamp for heating to fix the toner on the recording paper 10, and a pressure roller 52 that presses the recording paper 10 while sandwiching the heating roller 51 and the recording paper 10. Is provided. In the fixing device 5, the recording paper 10 onto which the toner image is transferred by the image forming device 4 is transported by guidance by a pair of transport rollers 53 installed between the image forming device 4 and the fixing device 5. The recording paper 10 on which the toner image has been transferred passes between the heating roller 51 and the pressure roller 52, thereby receiving the heating by the heating roller 51 and the pressure by the heating roller 51 and the pressure roller 52. . As a result, the transferred toner image is fixed on the recording paper 10, and an image based on the original image data is printed on the recording paper 10. The heating roller 51 may be one in which the surface of the heating roller 51 is heated by generating an eddy current on the surface by electromagnetic induction.

  The paper discharge mechanism 7 is provided outside the image forming apparatus 1 and the paper discharge roller 71 for discharging the recording paper 10 that has passed through the image inspection apparatus 6 to the outside of the image forming apparatus 1. A paper discharge tray 72 for receiving the printed recording paper 10. The paper discharge mechanism 7 configured as described above guides the recording paper 10 on which the toner image is fixed on the recording surface by the fixing device 5 by the drive of the paper discharge roller 71 from the image inspection device 6. Then, the paper is discharged to a paper discharge tray 72 outside the image forming apparatus 1.

2. Configuration of Image Inspection Apparatus As shown in FIG. 2, the image inspection apparatus 6 receives a light source 61 that irradiates light onto a recording paper 10 on which an image is printed, and receives reflected light from the recording paper 10 and converts it into an electrical signal. The solid-state imaging device 62, the imaging lens 63 that forms an image of the reflected light from the recording paper 10 on the solid-state imaging device 62, and the recording that moves in the sub-scanning direction (corresponding to the conveyance direction in the recording paper conveyance path Q). A glass plate 64 with which the image recording surface of the paper 10 abuts, reflecting mirrors 65A to 65C for guiding reflected light from the recording paper 10 to the imaging lens 63, and a reference plate for generating correction values for shading correction 66, a first polarizer 67 that aligns light emitted from the light source 61 with linearly polarized light, and a second polarizer 68 that determines the polarization direction of the light to be imaged on the solid-state imaging device 62.

  The reflecting mirror 65A is disposed on the optical path of specularly reflected light that is reflected at an angle substantially equal to the incident angle of the light from the light source 61. In other words, with reference to the normal line of the recording paper 10 at the reading position P1, the reflection is performed at a position where the straight line connecting the light source 61 and the reading position P1 and the straight line connecting the reflecting mirror 65A and the reading position P1 are symmetric. A mirror 65A is installed. A first polarizer 67 is disposed on the optical path of the light from the light source 61 that connects the light source 61 and the reading position P1. For example, the light source 61 is irradiated with light having directivity, such as a light emitting diode (LED) light source and a light guide member that uniformly emits light from the LED light source. Preferably. The light source 61 is arranged so that regular reflection light from the recording paper 10 is imaged in all pixels of a solid-state imaging device 62 described later.

  When reading the image on the recording paper 10, the light from the light source 61 passes through the first polarizer 67, so that the light that is linearly polarized in the polarization direction regulated by the transmission axis of the first polarizer 67 is changed. The reading position P1 is irradiated. When the irradiation light whose polarization direction is aligned by the first polarizer 67 enters the recording paper 10, the regular reflection light and the diffuse reflection light with respect to the irradiation light are reflected at the reading position P1 of the recording paper 10 and reflected by the reflecting mirror. Proceed on the optical path to 65A. The incident direction of the light incident on the recording paper 10 from the light source 61 through the first polarizer 67 is preferably 45 ° or less with respect to the normal line of the paper surface (image inspection surface) of the recording paper 10. The polarization direction by the first polarizer 67 is preferably perpendicular to the incident surface of the incident light with respect to the irradiated surface of the recording paper 10.

  At this time, since the optical path toward the reflecting mirror 65A coincides with the optical path of the regular reflection light at the reading position P1, only a part of the diffuse reflection light traveling in all directions is reflected unlike the regular reflection light. Incident on the mirror 65A. Therefore, the light intensity of the specularly reflected light incident on the reflecting mirror 65A is stronger than the light intensity of the diffusely reflected light also incident on the reflecting mirror 65A. The regular reflection light is linearly polarized light having the same polarization direction as that regulated by the first polarizer 67, while the diffuse reflection light is non-polarized light whose polarization direction is not fixed. . The regular reflection light and diffuse reflection light reflected by the reflecting mirror 65A are guided to the imaging lens 63 by the reflecting mirrors 65B and 65C, and pass through the imaging lens 63 so as to form an image in the imaging region of the solid-state imaging device 62. . That is, the reflecting mirrors 65A to 65C and the imaging lens 63 constitute an optical system that allows regular reflected light from the recording paper 10 to pass therethrough, and a first polarizer 67 is provided as part of the optical system. .

  On the optical path from the imaging lens 63 to the solid-state imaging device 62, a second polarizer 68 having optical elements (corresponding to “optical filters”) having different transmission axis directions is disposed. The light in the polarization direction along the transmission axis direction of the light enters the solid-state imaging device 62. That is, either regular reflection light or diffuse reflection light transmitted through the imaging lens 63 is selectively incident on each pixel in the solid-state image sensor 62 according to the transmission axis direction of each optical element constituting the second polarizer 68. be able to. Therefore, when the transmission axis direction of the optical element in the second polarizer 68 is a direction that blocks the light in the polarization direction of the regular reflection light, the diffuse reflection light is transmitted and incident on the solid-state image sensor 62. On the other hand, when the transmission axis direction of the optical element in the second polarizer 68 is not a direction that blocks the light in the polarization direction of the regular reflection light, the regular reflection light is mainly transmitted and incident on the solid-state imaging element 62.

At this time, the optical element 68a that shields the specularly reflected light from the second polarizer 68 (hereinafter referred to as “colorimetric optical element”) has its transmission axis direction as shown in FIG. The direction is perpendicular to the transmission axis direction of the polarizer 67. As a result, the specularly reflected light whose polarization direction is perpendicular to the transmission axis of the colorimetric optical element (corresponding to the “ colorimetric filter ”) 68a is shielded. Only the diffuse reflected light is incident on the pixel facing the optical element 68a. Then, the solid-state imaging device 62 performs a photoelectric conversion operation on the incident diffuse reflected light, and outputs image data representing the color component of the image formed on the recording paper 10 to the control device 8 (see FIG. 4). To do.

On the other hand, the optical element 68b (hereinafter referred to as “gloss measuring optical element”) that does not block the specularly reflected light in the second polarizer 68 has its transmission axis direction as shown in FIG. 3 (a) or (b). The first polarizer 67 is parallel or crossed with the transmission axis direction of the first polarizer 67. As a result, the specular reflection light is not blocked by the gloss measurement optical element (corresponding to a “ gloss measurement filter ”) 68b, and the regular reflection light is applied to the pixels of the solid-state imaging device 62 that are opposite to the gloss measurement optical element 68b. Is incident. Then, the solid-state imaging device 62 performs a photoelectric conversion operation on the incident regular reflection light, and outputs image data representing the gloss component of the image formed on the recording paper 10 to the control device 8 (see FIG. 7). To do.

  That is, as shown in FIG. 3A, in the gloss measuring optical element 68b in which the transmission axis direction coincides with the transmission axis direction of the first polarizer 67, the polarization direction of the regular reflection light coincides with the transmission axis direction. Then, the specularly reflected light is passed, and a part of the diffusely reflected light (diffusely reflected light whose change direction does not coincide with the transmission axis of the gloss measuring optical element 68b) is blocked. Further, as shown in FIG. 3B, the gloss measuring optical element 68b whose transmission axis direction intersects the transmission axis direction of the first polarizer 67 at a non-perpendicular and non-perpendicular angle transmits regular reflection light. However, it is sufficiently larger than the light flux of the diffusely reflected light that can be transmitted. Then, by determining the transmission axis direction as shown in FIG. 3B, the amount of specularly reflected light incident on the solid-state image sensor 62 can be reduced. It is possible to prevent the dynamic range of the solid-state image sensor 62 from being exceeded. Therefore, when the gloss measurement optical element 68b having the configuration shown in FIG. 3A or FIG. 3B is arranged, the solid-state image sensor 62 can output image data based on the amount of specularly reflected light.

  Further, as shown in FIG. 3C, when the gloss measuring optical element 68b that can transmit all the reflected light is disposed (including a configuration without the optical element), the solid-state image sensor 62 includes the regular reflected light and the reflected light. Each diffusely reflected light is incident, but the amount of specularly reflected light is larger than that of diffusely reflected light. Therefore, even if the optical element itself is not provided, the regular reflection from the solid-state image sensor 62 is the same as in the case where the gloss measuring optical element 68b having the configuration of FIG. 3A or FIG. Image data based on the amount of light can be output.

  As described above, in the image inspection apparatus 6, the second polarizer 68 includes the color measurement optical element 68 a and the gloss measurement optical element 68 b having different transmission axis directions. Image data can be output from the solid-state imaging device 62. As a result, the image inspection apparatus 6 performs image data (hereinafter referred to as “color image data”) based on diffused light transmitted through the colorimetric optical element 68a by one reading operation with respect to one recording sheet 10. )) And image data based on specularly reflected light transmitted through the gloss measurement optical element 68b (hereinafter referred to as “gloss image data”) can be output.

  The image inspection apparatus 6 can simultaneously output the color image data and glossy image data of the recording paper 10 when performing a reading operation on one recording paper 10. The image inspection apparatus 6 performs the reading operation of the reference plate 67 before performing the image reading operation of the recording paper 10. Thereby, in the control device 8 (see FIG. 4), the electrical signal output from the solid-state imaging device 62 when the reading operation is performed on the reference plate 67 is stored in advance as shading correction data.

  Therefore, the control device 8 (see FIG. 4) uses the shading correction data for each of the color image data and the glossy image data output from the solid-state image sensor 62 to perform the shading correction, whereby the light source 61 The variation in the amount of light in the main scanning direction can be suppressed. The reference plate 67 may be configured such that the white plate and the blackboard are adjacent to each other in the conveyance direction of the recording paper 10 and can be slid in the conveyance direction of the recording paper 10. As a result, shading correction data can be generated for each of the white plate portion and the blackboard portion of the reference plate 67, and shading correction can be applied to each of the color image data and the gloss image data in accordance with the respective black and white standards.

3. Components for Controlling the Operation of the Image Inspection Apparatus As described above, the image inspection apparatus 6 that performs the image reading operation on the recording paper 10 is supplied with a signal from the control apparatus 8 having the configuration shown in FIG. The operation is controlled by. Further, the image inspection device 6 controlled by the control device 8 outputs the color image data and the gloss image data generated by the solid-state image sensor 62 to the control device 8. A configuration for controlling the operation of the image inspection apparatus 6 will be described with reference to a block diagram shown in FIG. The control device 8 has a configuration for communicating with each device and the mechanisms 2 to 7 including the image inspection device 6 in the image forming apparatus 1 and controlling the operation of each device and the mechanisms 2 to 7. However, in FIG. 4, a configuration related to the image inspection apparatus 6 is shown, and the other configuration and description are omitted.

  The control device 8 includes a CPU (Central Processing Unit) 81 that executes various arithmetic processes and controls, a ROM (Read Only Memory) 82 that stores control programs, and a RAM (Random Access Memory) that temporarily stores arithmetic data. ) 83, an image data generation unit 84 that generates color image data and glossy image data from the electrical signal output from the solid-state imaging device 62, and a shading correction that is a correction value for the shading correction by the image data generation unit 84 A shading correction value calculation unit 85 that generates data, an input / output interface 87 that transmits / receives signals to / from the image inspection device 6, and a bus 88 that transmits / receives signals to establish communication between the blocks in the control device 8 .

  On the other hand, the image inspection apparatus 6 includes a light emission control unit 610 configured by a PWM (Pulse Width Modulator) circuit for setting the light emission amount of the light source 61 and an imaging control for controlling an imaging operation in the solid-state imaging device 62. A unit 620 and an output amplifier 621 that amplifies the electrical signal output from the solid-state image sensor 62. In addition, when the light source 61 is comprised by LED (light Emitting Device), you may comprise as a PWM circuit etc. which polarize the duty ratio of the pulse current which gives the light emission control part 610 to LED.

  In the image inspection device 6, a control signal from the control device 8 is given to the imaging control unit 620. Thereby, the image inspection apparatus 6 performs an imaging operation with the solid-state imaging device 62, and generates and outputs image data for one frame composed of color image data and glossy image data. That is, the color image data and the gloss image data generated by the solid-state image sensor 62 are alternately output to the control device 8 through the output amplifier 621.

  When the control device 8 receives the image data obtained by reading from the single recording paper 10 by the image inspection device 6 from the input / output interface 87, the control device 8 sends the image data to the image data generation unit 84. In the shading correction value calculation unit 85 of the control device 8, the image data when the reference plate 67 is read by the image inspection device 6 is already input, and the shading correction value is calculated and stored from the image data. .

  Then, the image data generation unit 84 processes the image data for one frame given from the image inspection device 6 in synchronization with the input timing of the image data of each pixel, and the color image data and the gloss image data. And are separated. Each of the color image data and the gloss image data is subjected to shading correction based on the shading correction value acquired in advance by the shading correction value calculation unit 85. As described above, each unit of the control device 8 operates to generate color image data and glossy image data based on the image data output when the recording paper 10 is read by the image inspection device 6.

  Note that the amplification factor of the output amplifier 621 may be changed depending on whether the image inspection apparatus 6 outputs color image data or gloss image data. That is, when the image inspection device 6 outputs color image data, the amplification factor of the output amplifier 621 is increased, while when the image inspection device 6 outputs glossy image data, the amplification factor of the output amplifier 621. Make it smaller. Thereby, each of the color image data and the gloss image data generated by the control device 8 can be processed as data of the same gradation. Note that the amplification of the data values of the color image data and the glossy image data is not performed by the output amplifier 621 but may be performed by the image data generation unit 84 of the control device 8.

  In the image forming apparatus 1 of the present invention, the solid-state imaging device 62 is configured by arranging a plurality of line sensors in which a plurality of pixels are arranged in one line. Further, in the image forming apparatus 1 of the present invention, the second polarizer 68 has an optical element corresponding to each pixel of the solid-state imaging element 62, and a plurality of them are arranged in either the main scanning direction or the sub-scanning direction. For each optical element group, at least one optical element in the optical element group is a gloss measurement optical element 68b, and the remaining optical elements are color measurement optical elements 68a. Thereby, the image inspection apparatus 6 can output each of color image data and glossy image data from the solid-state imaging device 62 that receives the light transmitted through the second polarizer 68.

  Each of the following embodiments describes an image forming apparatus having the above-described image forming apparatus 1 as a basic configuration. The configuration for outputting color image data and glossy image data in the image inspection apparatus will be described in more detail. Is. Therefore, in the following embodiments, details will be described focusing on the configuration of the solid-state imaging element 62 and the second polarizer 68 in the image inspection apparatus 6.

<First Embodiment>
An image forming apparatus according to a first embodiment of the present invention will be described below with reference to the drawings. FIG. 5 is a schematic diagram illustrating a configuration of the solid-state imaging device 62 of the image inspection apparatus in the image forming apparatus of the present embodiment, and FIG. 6 is a schematic diagram illustrating a configuration of the second polarizer 68 in the image inspection apparatus. is there. In this embodiment, in order to simplify the description, as shown in FIG. 5, the image inspection apparatus 6 includes a solid-state imaging device 62 in which 10-pixel line sensors are arranged in three rows. However, it is not limited to these numerical values.

  As shown in FIG. 5, the image inspection apparatus 6 in the image forming apparatus 1 according to the present embodiment includes a solid-state imaging device 62 and line sensors CL <b> 1 to CL <b> 3 in which a plurality of pixels are arranged in one column. "). The line sensor CL1 is configured by arranging photodiodes P1-1 to P1-10 serving as photoelectric conversion elements forming pixels in the main scanning direction (corresponding to the “first direction”). The line sensor CL1 transfers output charges from the photodiodes P1-1 to P1-10 through a transfer device (not shown), converts the output charges into voltage signals by the amplifier A1, and outputs the voltage signals to the control device 8. Similarly, the line sensor CL2 includes photodiodes P2-1 to P2-10 and an amplifier A2, and the line sensor CL3 includes photodiodes P3-1 to P3-10 and an amplifier A3.

  As shown in FIG. 6, the second polarizer 68 includes three filter rows FL1 to FL3 arranged in parallel in the sub-scanning direction so as to correspond to the configuration of the line sensors CL1 to CL3 in the solid-state imaging device 62 described above. ing. The filter row FL1 includes filters F1-1 to F1-10 disposed on the incident optical paths to the photodiodes P1-1 to P1-10 that constitute the line sensor CL1. The filter row FL2 includes filters F2-1 to F2-10 disposed on the incident light paths to the photodiodes P2-1 to P2-10 of the line sensor CL2. The filter row FL3 includes filters F3-1 to F3-10 disposed on the incident optical paths to the photodiodes P3-1 to P3-10 of the line sensor CL3.

  The second polarizer 68 includes three filters F1-N to F3-N arranged adjacent to each other in the sub-scanning direction (N represents a filter position in the filter row, and in this example, a natural number of 1 to 10). Of these, one filter is constituted by the gloss measuring optical element 68b, and the remaining two filters are constituted by the color measuring optical element 68a. That is, the second polarizer 68 of the present embodiment includes at least one of the plurality of filters arranged adjacent to each other in the sub-scanning direction by the gloss measuring optical element 68b, and the remaining filters as the color measuring optical elements. 68a. In the configuration example of FIG. 6, the measurement optical element 68b has no optical element as shown in FIG.

  The second polarizer 68 includes a group of three adjacent filters in each of the filter rows FL1 to FL3 of each row, and one of the filters is composed of the gloss measuring optical element 68b, and the remaining two filters. The filter is composed of a colorimetric optical element 68a. In the example of FIG. 6, if the filter F1- (N + 2) of the three filters F1-N to F1- (N + 2) adjacent in the main scanning direction in the filter row FL1 is configured by the gloss measurement optical element 68b, the remaining The filters F1-N and F1- (N + 1) are constituted by the colorimetric optical element 68a.

  In the filter row FL2, among the adjacent three filters F2-N to F2- (N + 2), the filter F2- (N + 1) is configured by the gloss measuring optical element 68b, and the filters F2-N, F2- (N + 2) ) Is constituted by a colorimetric optical element 68a. Further, in the filter row FL3, of the three adjacent filters F3-N to F3- (N + 2), the filter F3-N is configured by the gloss measurement optical element 68b, and the filters F3- (N + 1), F3- (N + 2) ) Is constituted by a colorimetric optical element 68a.

  With this configuration, the filters F1-N, F1- (N + 1), F2-N, F2- (N + 2), F3- (N + 1), and F3- (N + 2) of the second polarizer 68 are colorimetric. Since the specularly reflected light perpendicular to the transmission axis of the optical element 68a is shielded, the photodiodes P1-N, P1- (N + 1), P2-N, P2- (N + 2), P3 of the solid-state image sensor 62 are blocked. Only diffuse reflection light is incident on each of − (N + 1) and P3− (N + 2). On the other hand, in the filters F1- (N + 2), F2- (N + 1), and F3-N of the second polarizer 68, the specularly reflected light is transmitted through the gloss measuring optical element 68b. Regularly reflected light is incident on (N + 2), P2- (N + 1), and P3-N.

  Accordingly, in the solid-state imaging device 62, the color image data for two pixels and the gloss image data for one pixel are output from the line sensors CL1 to CL3 at a cycle of three pixels. The image data output from the solid-state image sensor 62 is color image data for two pixels of the image data at the same pixel position in the sub-scanning direction, while gloss image data for one pixel. In the image data for three lines output from the solid-state imaging device 62, the pixel position in the sub-scanning direction of the glossy image data is switched for each pixel within a three-pixel cycle along the main scanning direction.

  In this way, the image inspection apparatus 6 can simultaneously output the color image data and the glossy image data of the recording paper 10 every three lines, so the time required for the inspection operation on the recording paper 10 in the image inspection apparatus 6 And the conveyance speed until the recording paper 10 is printed out can be increased. The control device 7 receives two lines of color image data and one line of glossy image data from the image inspection device 6. At this time, as described above, the pixel position of the gloss image data is not adjacent to each other in the main scanning direction and the sub scanning direction, so that the color image data at the pixel position from which the gloss image data is output can be It can be calculated by interpolation using color image data acquired from the pixel position.

  In the present embodiment, the gloss measurement optical element 68b has no optical element as shown in FIG. 3C, as in the configuration example of FIG. 6, but as in the configuration example of FIG. The gloss measuring optical device 68b may be configured by an optical element (see FIG. 3A) whose transmission axis direction coincides with the transmission axis direction of the first polarizer 67, as in the configuration example of FIG. In addition, the optical device 68b for gloss measurement may be configured by an optical element (see FIG. 3B) whose transmission axis direction is inclined with respect to the transmission axis direction of the first polarizer 67.

  Further, in the present embodiment, as described above, the gloss measurement optical element 68b is configured such that all the reflected light can be transmitted as a configuration in which no optical element is provided. However, as shown in FIG. A light reduction (ND: Natural Density) filter 68c that attenuates the amount of light may be installed. In other words, the filters F1- (N + 2), F2- (N + 1), and F3-N of the second polarizer 68 are configured by a dimming (ND: Natural Density) filter 68c, thereby reducing the amount of specular reflection light. Are incident on the photodiodes P1- (N + 2) and P2- (N + 1) P3-N of the solid-state imaging device 62. Accordingly, since the amount of specularly reflected light incident on the solid-state image sensor 62 can be reduced, the amount of specularly reflected light received by the solid-state image sensor 62 can be prevented from exceeding the dynamic range of the solid-state image sensor 62.

  In the present embodiment, the image inspection apparatus 6 reads the gloss image data together with the color image data every three lines on the recording paper 10, but the gloss image data together with the color image data every line. May be read. When the gloss image data is read together with the color image data for each line, the line sensors CL1 to CL3 detect the color image data and the gloss image data in the L (L is a natural number of 1 or more) line to the L + 2 line. , The recording paper 10 is conveyed by one line, and the line sensors CL1 to CL3 output the color image data and glossy image data of the (L + 1) th line to the (L + 3) th line.

  Thereafter, when the recording paper 10 is further conveyed by one line, the line sensors CL1 to CL3 output color image data and glossy image data of the L + 2 line to the L + 4 line. At this time, color image data and glossy image data in the (L + 2) th row are output from each of the line sensors CL1 to CL3. Accordingly, the color image data and the gloss image data on the entire surface of the recording paper 10 can be acquired without interpolating the color image data and the gloss image data.

  Moreover, in this embodiment, what is necessary is just to comprise the solid-state image sensor 62 by the line sensor of several rows, and it is not restricted to what is comprised by line sensor CL1-CL3 like the above-mentioned example. The second polarizer 68 includes a filter corresponding to each pixel of the solid-state image sensor 62 by being configured with the same number of filter rows as the line sensors that configure the solid-state image sensor 62.

  At this time, the second polarizer 68 has at least one filter in each filter group when K (K is an integer of 3 or more) filters arranged adjacent to each other in the sub-scanning direction are set as one group. The gloss measuring optical element 68b is configured, and the remaining filters are configured by the color measuring optical element 68a. The second polarizer 68 is configured so that the gloss measuring optical element 68b is not adjacent to the filter arranged in the main scanning direction in each filter row. That is, it is assumed that the arrangement positions of the colorimetric optical element 68a and the gloss measuring optical element 68b in the filter group differ between adjacent filter groups in the main scanning direction.

  As another example of the present embodiment, as shown in FIG. 10, a case where the solid-state imaging device 62 is configured by four rows of line sensors CL1 to CL4 will be described below. At this time, the second polarizer 68 includes filter rows FL1 to FL4 corresponding to the line sensors CL1 to CL4 of the solid-state imaging device 62, as shown in FIG. Of the four filters F1-N to F4-N arranged adjacent to each other in the sub-scanning direction, one filter is configured by the gloss measuring optical element 68b, and the remaining three filters are configured by the color measuring optical element 68a. Consists of.

  The second polarizer 68 includes a group of four adjacent filters in each of the filter rows FL1 to FL4 of each row, and one of the filters is composed of the gloss measuring optical element 68b, and the remaining three filters The filter is composed of a colorimetric optical element 68a. In the example of FIG. 11, among the four filters F1-N to F1- (N + 3) adjacent in the main scanning direction in the filter row FL1, the filter F1- (N + 3) is configured by the gloss measuring optical element 68b, and the filter row In FL2, among the four adjacent filters F2-N to F2- (N + 3), the filter F2- (N + 2) is constituted by the gloss measuring optical element 68b, and in the filter row FL3, the four adjacent filters F3-N ~ F3- (N + 3), the filter F3- (N + 1) is constituted by the gloss measurement optical element 68b, and the filter array FL4 includes the filter F4 among the four adjacent filters F4-N to F4- (N + 2). -N is constituted by the gloss measuring optical element 68b.

  Accordingly, in the solid-state imaging device 62, color image data for three pixels and glossy image data for one pixel are output from the line sensors CL1 to CL4 in a cycle of four pixels. The image data output from the solid-state image sensor 62 is color image data for three pixels among the image data at the same pixel position in the sub-scanning direction, while gloss image data is for one pixel. In the image data for four lines output from the solid-state imaging device 62, the pixel position in the sub-scanning direction of the glossy image data is switched for each pixel within a four-pixel cycle along the main scanning direction. In this way, the image inspection apparatus 6 can simultaneously output the color image data and the glossy image data of the recording paper 10 every four lines, so that the recording paper 10 can be compared with the configuration examples of FIGS. It is possible to further increase the conveyance speed until printing is output.

<Second Embodiment>
An image forming apparatus according to a second embodiment of the present invention will be described below with reference to the drawings. FIG. 12 is a schematic diagram illustrating a configuration of the solid-state imaging element 62 of the image inspection apparatus in the image forming apparatus of the present embodiment, and FIG. 13 is a schematic diagram illustrating a configuration of the second polarizer 68 in the image inspection apparatus. is there. 12 and 13, the same parts as those in FIGS. 5 and 6 are denoted by the same reference numerals, and detailed description thereof is omitted. In this embodiment, in order to simplify the description, as shown in FIG. 12, the image inspection apparatus 6 includes solid-state imaging devices 62 in which 10-pixel line sensors are arranged in five rows. It is not limited to these numerical values.

  As shown in FIG. 12, the image inspection apparatus 6 in the image forming apparatus 1 according to the present embodiment includes a solid-state imaging device 62 in which line sensors CL1 to CL5 in which a plurality of pixels are arranged in a line are arranged in the sub-scanning direction. As in the first embodiment, the line sensor CL1 includes photodiodes P1-1 to P1-10 and an amplifier A1, and the line sensor CL2 includes photodiodes P2-1 to P2-10 and an amplifier A2. The line sensor CL3 includes photodiodes P3-1 to P3-10 and an amplifier A3. The line sensor CL4 includes photodiodes P4-1 to P4-10 and an amplifier A4. The line sensor CL5 includes a photodiode P5-1. To P5-10 and an amplifier A5.

  As shown in FIG. 13, the second polarizer 68 includes five filter rows FL1 to FL5 arranged in parallel so as to correspond to the configuration of the line sensors CL1 to CL5 in the solid-state imaging device 62 described above. In the first embodiment, the filter array FL1 includes filters F1-1 to F1-10, the filter array FL2 includes filters F2-1 to F2-10, and the filter array FL3 includes a filter F3-1. To F3-10, the filter row FL4 includes filters F4-1 to F4-10, and the filter row FL5 includes filters F5-1 to F5-10.

  In the present embodiment, as shown in FIG. 13, each of the filters F1-1 to F4-10 of each of the filter rows FL1 to FL4 is constituted by a colorimetric optical element 68a shown in FIG. Further, each of the filters F5-1 to F5-10 of the filter row FL5 is constituted by a gloss measuring optical element 68b shown in FIGS. 3 (a) to 3 (c). In the configuration example of FIG. 13, the filter array FL5 has no optical element as shown in FIG.

  With this configuration, in the filter rows FL1 to FL4 of the second polarizer 68, specularly reflected light that is perpendicular to the transmission axis of the colorimetric optical element 68a is shielded. Only diffuse reflected light is incident on each of the line sensors CL1 to CL4. On the other hand, in the filter row FL5 of the second polarizer 68, the specularly reflected light is transmitted through the gloss measuring optical element 68b, so that the specularly reflected light is incident on the line sensor CL5 of the solid-state image sensor 62.

  In the image inspection apparatus 6, the reflected light of the recording paper 10 is transmitted through the second polarizer 68, so that the solid-state imaging device 62 outputs color image data for four lines from the line sensors CL 1 to CL 4, and at the same time, the line sensor. Glossy image data for one line is output from CL5. By doing so, the image inspection apparatus 6 can simultaneously output the color image data and the glossy image data of the recording paper 10 every five lines, so that the time required for the inspection operation on the recording paper 10 in the image inspection apparatus 6 And the conveyance speed until the recording paper 10 is printed out can be increased. Further, by using the color image data for four lines, the resolution of the color image data in the sub-scanning direction can be increased, and the color reproducibility based on the color image data from the image inspection apparatus 6 can be made high definition. .

  In the present embodiment, as in the first embodiment, each of the filters F5-1 to F5-10 in the filter row FL5 is configured by the gloss measurement optical element 68b shown in FIGS. 3 (a) and 3 (b). Alternatively, it may be configured by a neutral density filter 68c (see FIG. 9).

  Moreover, in this embodiment, what is necessary is just to comprise the solid-state image sensor 62 by the line sensor of multiple rows, and it is not restricted to what is comprised by line sensor CL1-CL5 like the above-mentioned example. Further, the second polarizer 68 is also composed of the same number of filter rows as the number of row sensors constituting the solid-state imaging device 62, and K (K is an integer of 3 or more) rows of filter rows. Among them, at least one row is constituted by the gloss measuring optical element 68b. The number of filter rows formed by the color measuring optical element 68a is preferably larger than the number of filter rows formed by the gloss measuring optical element 68b.

<Third Embodiment>
An image forming apparatus according to a third embodiment of the present invention will be described below with reference to the drawings. FIG. 14 is a schematic diagram showing the configuration of the second polarizer 68 of the image inspection apparatus in the image forming apparatus of this embodiment. The image forming apparatus according to the present embodiment will be described below assuming that the image forming apparatus includes the solid-state imaging device having the configuration shown in FIG. 5 as in the first embodiment. In the present embodiment, in order to simplify the description, as in the first embodiment, as shown in FIG. 5, the image inspection apparatus 6 has a solid-state imaging device in which 10-pixel line sensors are arranged in three rows. However, the present invention is not limited to these values. In FIG. 14, the same components as those in FIG. 6 are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 14, the image inspection apparatus 6 in the image forming apparatus 1 of the present embodiment includes a second polarizer 68 in which three filter rows FLx1 to FLx3 are arranged in the sub-scanning direction. The filter rows FLx1 to FLx3 all have the same configuration, and the color measuring optical elements 68a and the gloss measuring optical elements 68b are alternately arranged. That is, in the second polarizer 68, the color measurement optical elements 68a arranged in a line in the sub-scanning direction and the gloss measurement optical elements 68b arranged in a line in the sub-scanning direction are main scanning. Alternating in the direction. Further, the color measuring optical element 68 a in the second polarizer 68 is an optical element in which the transmission axis direction coincides with the transmission axis direction of the first polarizer 67 as shown in FIG.

  With this configuration, regular reflection light is blocked by the filters F1-N, F2-N, and F3-N of the second polarizer 68, and thus the photodiodes P1-N and P2- of the solid-state imaging device 62 are blocked. Only diffuse reflected light is incident on each of N and P3-N. On the other hand, the filters F1- (N + 1), F2- (N + 1), and F3- (N + 1) of the second polarizer 68 transmit regular reflection light, so that the photodiodes P1- (N + 1), P2 of the solid-state image sensor 62 are transmitted. Regular reflection light is incident on − (N + 1) and P3− (N + 1).

  Accordingly, in the solid-state imaging device 62, the color image data and the gloss image data are alternately output from the line sensors CL1 to CL3 in the same cycle. In this way, the image inspection apparatus 6 can simultaneously output the color image data and the glossy image data of the recording paper 10 every three lines, so the time required for the inspection operation on the recording paper 10 in the image inspection apparatus 6 And the conveyance speed until the recording paper 10 is printed out can be increased.

  In the present embodiment, similarly to the first embodiment, the solid-state imaging device 62 may be configured by a plurality of lines of line sensors, and is configured by the line sensors CL1 to CL3 as in the above example. Not limited to things. The second polarizer 68 includes a filter corresponding to each pixel of the solid-state image sensor 62 by being configured with the same number of filter rows as the line sensors that configure the solid-state image sensor 62.

  In the present embodiment, the second polarizer 68 is configured by the filter rows FLx1 to FLx3 in which the colorimetric optical element 68a and the gloss measuring optical element 68b are arranged at the same pixel position in the main scanning direction. As shown in FIG. 15, in the second column, a filter column in which a color measuring optical element 68a and a gloss measuring optical element 68b are arranged opposite to the first and third filter columns FLx1 and FLx3. It may be configured with FLy2. That is, in the second polarizer 68, the color measuring optical element 68a and the gloss measuring optical element 68b are alternately arranged in both the main scanning direction and the sub scanning direction.

<Fourth Embodiment>
An image forming apparatus according to a fourth embodiment of the present invention will be described below with reference to the drawings. FIG. 16 is a schematic diagram showing the configuration of the second polarizer 68 of the image inspection apparatus in the image forming apparatus of this embodiment. Note that the image forming apparatus according to the present embodiment will be described below assuming that the image forming apparatus includes the solid-state imaging device having the configuration illustrated in FIG. 12, as in the second embodiment. And in this embodiment, in order to simplify the description, as in the second embodiment, as shown in FIG. 12, the image inspection apparatus 6 has a solid-state imaging device in which 10-pixel line sensors are arranged in five rows. However, the present invention is not limited to these values.

  As shown in FIG. 16, the image inspection apparatus 6 in the image forming apparatus 1 of the present embodiment includes a metal thin film 68 d finely processed into another hole shape as the second polarizer 68. The metal thin film 68 b that constitutes the second polarizer 68 has a plate shape that covers the line sensors CL <b> 1 to CL <b> 5 that constitute the solid-state imaging device 62. The metal thin film 68b has a perforated plate shape in which through holes 681 are provided every other pixel along the main scanning direction and the sub-scanning direction.

  With this configuration, since the reflected light passes only through the through hole 681 of the metal thin film 68d, the reflected light that has passed through the through hole 681 of the metal thin film 68d is incident on the solid-state imaging device 62. It will be. By the way, the solid-state imaging device 62 has the odd-numbered photodiodes PD1 disposed at the pixel positions corresponding to the through holes 681 in the line sensors CL1, CL3, and CL5, respectively. Even-numbered photodiodes PD4 are arranged at pixel positions corresponding to the holes 681. That is, the even-numbered photodiodes PD2 in the line sensors CL1, CL3, and CL5 and the odd-numbered photodiodes PD3 in the line sensors CL2 and CL4 are covered with the metal thin film 68d.

  The solid-state imaging device 62 receives the specularly reflected light passing through the through hole 681 by the photodiode PD1 in the line sensors CL1, CL3, and CL5 and the photodiode PD4 in the line sensors CL2 and CL4. On the other hand, since the photodiode PD2 in the line sensors CL1, CL3, and CL5 and the photodiode PD3 in the line sensors CL2 and CL4 are covered with the metal thin film 68d, adjacent pixel positions in the main scanning direction and the sub scanning direction, respectively. The diffuse reflected light passing through the through hole 681 is received.

  Therefore, the solid-state imaging device 62 alternately outputs gloss image data and color image data for each pixel from the line sensors CL1 to CL5. At this time, when the line sensors CL1, CL3, and CL5 alternately output the color image data and the gloss image data in this order, the line sensors CL2 and CL4 alternately output the gloss image data and the color image data in this order.

  In the present embodiment, as in the second embodiment, the solid-state imaging device 62 may be configured by a plurality of lines of line sensors, and is configured by the line sensors CL1 to CL4 as in the above example. Not limited to things. The second polarizer 68 is composed of a porous metal thin film 68d that covers the line sensor constituting the solid-state imaging device 62, and the through hole 681 in the metal thin film 68d is one pixel at a position corresponding to each line sensor. It is provided in a place. In the present embodiment, the second polarizer 68 is not limited to the metal thin film 68d as long as it shields the reflected light from the recording paper 10, and for example, a resin material having a light shielding property. It may be made of a material other than metal, such as a thin film made of.

  In the basic configuration and the first to fourth embodiments described above, the second polarizer 68 is disposed between the solid-state imaging device 62 and the imaging lens 63. What is necessary is just to be arrange | positioned on the optical path which light advances. That is, the second polarizer 68 is connected to the optical path connecting the reading position P1 of the recording paper 10 and the reflecting mirror 65A, the optical path connecting the reflecting mirrors 65A and 65B, the optical path of the reflecting mirrors 65B and 65C, and the reflecting mirror 65C. It may be arranged on the optical path connecting the image lens 63 or the like.

  In the basic configuration and the first to fourth embodiments described above, the first polarizer 67 is disposed between the light source 61 and the reading position P1, but for example, the reading position of the recording paper 10 is used. The light reflected from the recording paper 10 may be disposed at a position where it is polarized before entering the second polarizer 68, such as on an optical path connecting P1 and the reflecting mirror 65A. Furthermore, in the above-described basic configuration and the first to fourth embodiments, the electrophotographic image forming apparatus has been described as an example of the image forming apparatus in the present invention. However, the above-described image inspection apparatus and control apparatus are described above. As long as it is provided, the image forming apparatus is not limited to the electrophotographic method, and may be an image forming apparatus including an image forming mechanism of another method such as an ink jet method.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Image reading apparatus 3 Paper feed mechanism 4 Image forming apparatus 3 Fixing apparatus 6 Image inspection apparatus 7 Paper discharge mechanism 8 Control apparatus 61 Light source 62 Solid-state image sensor 63 Imaging lens 64 Glass plate 65A-65C Reflective mirror 66 Reference | standard Plate 67 First polarizer 68 Second polarizer 81 CPU
82 ROM
83 RAM
84 Image data generation unit 85 Shading correction value calculation unit 87 Input / output interface 88 Bus 610 Light emission control unit 620 Imaging control unit 621 Output amplifier

Claims (14)

A light source that irradiates light on an image formed on the recording paper, an optical system that configures an optical path through which the specularly reflected light from the light source passes on the recording paper, and light that is guided by the optical system is received. In an image inspection apparatus comprising:
A first polarizer that is disposed on an optical path from the light source to the recording paper, and that transmits light linearly polarized in a predetermined polarization direction of the irradiation light from the light source toward the recording paper;
A second polarizer that is provided as part of the optical system and regulates the polarization direction of light received by the solid-state imaging device;
With
A plurality of pixels arranged in a first direction are arranged in a plurality of columns in a second direction orthogonal to the first direction to constitute the solid-state imaging device,
The second polarizer has a colorimetric filter that shields specularly reflected light from the recording paper and a gloss measurement filter that transmits the specularly reflected light, and for each pixel constituting the solid-state imaging device, Arrange one of the colorimetric filter and the gloss measurement filter,
An image inspection apparatus for simultaneously outputting color image data and glossy image data of an image of the recording sheet while passing one recording sheet.   The image inspection apparatus according to claim 1, wherein in the second polarizer, the gloss measurement filter is disposed for each predetermined pixel position along the first direction.   3. The image inspection apparatus according to claim 1, wherein in the second polarizer, at least one gloss measurement filter is disposed at all pixel positions adjacent along the second direction. 4. .   4. The second polarizer according to claim 1, wherein at least one gloss measurement filter is disposed at all pixel positions along the first direction. 5. Image inspection device.   The image inspection apparatus according to claim 1, wherein in the second polarizer, the gloss measurement filter and the color measurement filter are alternately arranged along the first direction. The image inspection apparatus according to claim 1, wherein the gloss measurement filter is configured to transmit all reflected light. The image inspection apparatus according to claim 6, wherein the gloss measurement filter is a neutral density filter that attenuates the amount of transmitted light. The image inspection apparatus according to claim 1, wherein a transmission axis direction of the gloss measurement filter intersects with a polarization direction of the regular reflection light at an angle smaller than 90 °. The image inspection apparatus according to claim 8, wherein a transmission axis direction of the gloss measurement filter is the same as a polarization direction of the regular reflection light. The image inspection apparatus according to claim 1, wherein a transmission axis direction of the colorimetric filter is perpendicular to a polarization direction of the regular reflection light. The second polarizer is composed of a thin film finely processed into a porous shape, and the thin film portion functions as the colorimetric filter , while the through-hole portion of the thin film functions as the gloss measurement filter. The image inspection apparatus according to claim 1, wherein the image inspection apparatus is an image inspection apparatus.   The image inspection apparatus according to claim 1, wherein a polarization direction of the first polarizer is perpendicular to an incident surface of incident light with respect to an irradiated surface of the recording paper. .   The image according to any one of claims 1 to 12, wherein the light source is arranged so that the regular reflection light from the recording paper is imaged by all pixels of the solid-state imaging device. Inspection device.   An image forming apparatus comprising the image inspection apparatus according to claim 1.

Images