JP2012247280A - Image inspection device and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive image inspection device and image forming apparatus for highly accurately inspecting concentration distribution and glossiness distribution in the overall area of an object to be measured.SOLUTION: The image inspection device is configured to simultaneously light an illumination device 14 for glassiness and an illumination device 15 for concentration, and to make a paper feeding device 13 convey an output image. Also, the image inspection device includes: an image pickup element line 11a for receiving only the regular reflection rays of light of invisible rays of light from the surface of the image of an object 22 to be inspected, and for outputting glossiness distribution on the basis of the light quantity; and an image pickup element line 11b for receiving only the distributed reflection rays of light of visible rays of light reflected after transmitted inside the image of the object 22 to be inspected, and for outputting concentration distribution on the basis of the light quantity. Thus, it is possible to simultaneously inspect the glossiness distribution and concentration distribution of the whole area of the object to be inspected.

Description

  The present invention relates to an image inspection apparatus that inspects an image of an object to be inspected, and an image forming apparatus including the image inspection apparatus.

  In the electrophotographic image forming apparatus, the formed toner image is melted and fixed on the paper by the heat fixing device, so that the glossiness of the toner image increases in accordance with the toner adhesion amount. However, even if an image can be formed with an accurate toner adhesion amount distribution, the fixing state of the toner image may become non-uniform and the fixing state may change in a streak shape due to a defect of the heat fixing device. In such a case, the density distribution of the toner that forms the image has almost no change, but when observed from an oblique direction, a change is seen in a streak shape, and it is determined that the image is called a fixing streak. Therefore, the gloss distribution of the object to be inspected is detected in order to detect this fixing stripe. Also, when an electrophotographic image forming apparatus is used as a digital printing machine, it is attempted to form gloss on an output image by using transparent toner, or to form an image using high gloss paper. There is a growing demand for image quality.

  As an inspection apparatus for inspecting an output image, an image inspection apparatus capable of inspecting an image output from an electrophotographic image forming apparatus on demand, and capable of inspecting not only the density distribution but also the gloss distribution of the entire output image is desired. ing. As described in the JIS optical field (JIS Z 8722-2000 “Color Measurement Method—Reflection and Transmission Object Color”), the density distribution is measured by irradiating the object to be inspected at a predetermined angle with illumination light. Let The irradiation light transmitted in the image on the object to be inspected formed with the toner of each color is partially absorbed by the toner of each color, the remaining irradiation light is diffusely reflected, and the amount of the diffuse reflection light is measured. Done in In addition, the gloss distribution is measured by irradiating the object to be inspected with a certain angle of illumination light as described in detail in the optical field of JIS (JIS Z 8741-1997 “Specular Gloss Measurement Method”). This is done by measuring the amount of outgoing light regularly reflected from the object to be inspected. In this case, the incident angle of the irradiation light and the emission angle of the reflected light coincide with each other, and the angle is set according to the object to be inspected.

  A method described in Patent Document 1 is known as a method for measuring the gloss distribution of an output image, and a method described in Patent Document 2 is known as a method for measuring the gloss distribution and density distribution of an output image. In the method of the above-mentioned patent document 1, parallel illumination light is irradiated from a predetermined incident angle to an object to be inspected, and an image is captured by a two-dimensional image pickup unit arranged in a direction in which the object is regularly reflected from the object to be inspected. A two-dimensional gloss distribution is acquired. However, in Patent Document 1, the two-dimensional imaging unit can acquire only a local gloss distribution in a predetermined area.

  The method of Patent Document 2 is a reflective linear light source as one gloss distribution inspection illumination means, a diffuse reflection linear light source as a density distribution inspection illumination means, a half mirror, and an optical reading means. A line sensor camera is used. The irradiation light emitted from the reflecting linear light source is reflected by the half mirror and applied to the object to be inspected, and the reflected light reflected from the object to be inspected passes through the half mirror and is received by the line sensor camera. The On the other hand, the irradiation light emitted from each diffuse reflection linear light source is first applied to the inspection object, and the reflected light reflected from the inspection object passes through the half mirror and is received by the line sensor camera. . Then, the object to be inspected is scanned in one direction by alternately turning on the reflecting linear light source and each of the diffuse reflecting linear light sources. As a result, the line sensor camera can receive the reflected light from the object to be inspected one-dimensionally and acquire the gloss distribution and density distribution of the entire output image.

  However, in the method of Patent Document 2, the amount of each reflected light reaching the line sensor camera by using the half mirror is greatly reduced compared to the amount of irradiated light. For this reason, there has been a problem that the voltage value of the output signal of the line sensor camera becomes low and an accurate inspection result cannot be obtained. In addition, as in the method of the above-mentioned Patent Document 2, a density image and a glossy image are sequentially read line by line and image reading is performed with high resolution, so that a line sensor camera with a high operation clock is required and the cost is high. Furthermore, so-called sequential blinking is performed in which the linear light source for reflection and each linear light source for diffuse reflection are alternately turned on in synchronization with the operation clock of the line sensor camera. High cost. In addition, since the inspection object is conveyed at a constant speed in the sub-scanning direction and sequentially read line by line, the preceding reading point and the subsequent reading point are not the same. For this reason, the reading points of the density image and the glossy image are not completely the same, and are shifted by 1/2 pixel in the sub-scanning direction. As a result, image processing for correcting the deviation of 1/2 pixel is necessary, which is disadvantageous for high-speed processing.

  In Japanese Patent Application No. 2010-96931 (hereinafter referred to as the prior application), the applicant of the present application is a gloss illumination device that is a gloss distribution inspection illumination device, a density illumination device that is a density distribution inspection illumination device, and an imaging device. Has proposed an image inspection apparatus provided. In the image inspection apparatus of this prior application, an image sensor is disposed at a position where the irradiation light irradiated from the gloss illumination device is directly regularly reflected from the object to be inspected, and irradiation is performed from the gloss illumination device by the arranged image sensor. The gloss distribution and density distribution acquired based on the specularly reflected light with respect to the illumination light and the diffusely reflected light with respect to the illumination light irradiated from the density illumination device are inspected. Since the illumination light emitted from the concentration illumination device is diffusely reflected from the image of the object to be inspected, the position of the imaging element may be arbitrary. According to the image inspection apparatus of the prior application, each line of one line (one-dimensional) gloss distribution and density distribution based on a sufficient amount of regular reflection light or diffuse reflection light without using the half mirror of Patent Document 2 is used. Gloss distribution and density distribution can be inspected with high accuracy over the entire area of the object to be inspected by measuring and transporting the output image by the transport device.

  However, in the image inspection apparatus of the prior application, the gloss illumination device is turned on, the density illumination device is turned off, and the illumination light is applied to the 1-line reading area, so that the image sensor corrects the normal from the reading area. Get the amount of reflected light. Then, the gloss distribution of the reading region is measured based on the acquired amount of the regular reflection light. Next, the illumination device for gloss is turned off, the illumination device for concentration is turned on, and the illumination light for concentration is irradiated to the reading region of one line, whereby the amount of diffuse reflected light from the reading region is acquired by the imaging device. Then, the density distribution of the reading region is measured based on the acquired amount of diffuse reflected light. That is, even in the image inspection apparatus of the prior application, it is necessary to have a control device that sequentially controls the lighting device for lighting and the lighting device for density in accordance with the operation clock of the image sensor, thereby increasing the cost of the device. It becomes. Further, the acquired image positions of the gloss distribution and the density distribution are shifted by one operation clock in the transport direction, and the reading points of the density image and the gloss image are not completely the same, but are shifted by 1/2 pixel in the sub-scanning direction. For this reason, an image processing apparatus that performs image processing for correcting this deviation is required, which increases the cost of the apparatus. Furthermore, in order to ensure the reading resolution in the conveyance direction of both the density distribution and the gloss distribution, an operation clock is required for each distribution reading, and as a result, the image must be read with twice the operation clock, and an expensive image sensor is required. Necessary. Thus, even the image inspection apparatus of the prior application has not been able to solve the high cost of the apparatus, which is a part of the problem of Patent Document 2.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a low-cost image inspection apparatus and image formation while being able to inspect the density distribution and the gloss distribution over the entire area of the measurement target with high accuracy. Is to provide a device.

To achieve the above object, the invention of claim 1 is directed to a concentration distribution inspection illumination means for irradiating a concentration distribution inspection illumination light to an inspection target object on which an image is formed, and to the inspection target object. And an optical reading means for receiving diffusely reflected light and specularly reflected light reflected from the object to be inspected, and illumination means for irradiating gloss distribution pre-inspection illumination light, In the image inspection apparatus for inspecting the density distribution and the gloss distribution of the image on the inspection object acquired based on the light amount of the diffusely reflected light and the light amount of the regular reflected light received by the reading unit, The illumination means irradiates the illumination light for density distribution inspection that is visible light, the illumination means for gloss distribution irradiates illumination light for gloss distribution inspection that is invisible light, and the optical reading means performs the density distribution inspection. Lighting means and said The light distribution illumination means is turned on at the same time, and only the diffuse reflected light of the visible light diffused and reflected by the image forming object after passing through the image on the inspection object is received and the amount of the diffuse reflected light is received. And a first optical reading unit that outputs a density distribution based on the image, and receives only the specularly reflected light of the invisible light that is specularly reflected from the surface of the image on the object to be inspected to obtain a light quantity of the specularly reflected light. And a second optical reading means for outputting a gloss distribution based on the second optical reading means.
According to a second aspect of the present invention, in the image inspection apparatus according to the first aspect, the first optical reading unit includes an image sensor line in which image sensors having sensitivity to the diffuse reflected light of the visible light are arranged in a line. And the first optical reading means includes image pickup element lines for each of RGB, in which image pickup elements having sensitivity to RGB of the visible light are arranged in a line.
The invention of claim 3 is the image inspection apparatus according to claim 2, wherein the visible light is white light.
According to a fourth aspect of the present invention, there is provided the image inspection apparatus according to any one of the first to third aspects, wherein the object to be inspected is provided between the illumination means for gloss distribution and the object to be inspected. A polarizing filter is provided between each of the second optical reading unit and the second optical reading unit, and reflected from the surface of the inspection object of the invisible light for inspecting the gloss distribution irradiated from the gloss distribution illumination unit. The polarization angle of each polarizing filter is set so that only the light component received is received by the second optical reading means.
Further, the invention according to claim 5 is equipped with the image inspection apparatus according to any one of claims 1 to 4, inspecting an image formed on the recording medium by the image inspection apparatus, and based on the inspection result. The image forming is controlled.

  In the present invention, when illumination light is irradiated to an image formed by the image forming apparatus, the color component of the illumination light that is the same as the color of the image component such as multicolor toner constituting the image is absorbed by the image component and absorbed. The remaining color components of the illumination light are reflected. Therefore, the density of the image on the object to be inspected is obtained from the amount of diffusely reflected light that is reflected light in which part of the irradiated light is absorbed and the rest is reflected. That is, an image component having a high density absorbs much of the same color component of illumination light as that color, so that the amount of diffuse reflected light is reduced. On the other hand, in the image component with a low density, the color component of the illumination light is little absorbed and the amount of diffuse reflected light is large. Therefore, the density distribution of the image can be obtained by measuring the amount of diffuse reflected light of each color and measuring the density of the image based on the amount of light. From this, the illumination light for density distribution inspection irradiated on the object to be inspected is light absorbed by the image components constituting the image and becomes visible light having each color component such as RGB. On the other hand, the gloss distribution of the image on the object to be inspected corresponds to the light amount distribution of specularly reflected light that is specularly reflected from the surface of the image. For this reason, the illumination light for gloss distribution inspection irradiated on the object to be inspected may be light reflected on the image on the object to be inspected, and may be either visible light or invisible light. When inspecting the density distribution and gloss distribution by irradiating only the visible light to the object to be inspected, the light component corresponding to the density of the image is mixed with the light component corresponding to the density of the image, and the density distribution cannot be measured accurately. As a result, the illumination light for density distribution inspection that is irradiated on the object to be inspected to measure the density distribution of the image is visible light, and the illumination light for inspection of the gloss distribution to be irradiated on the object to be measured to measure the gloss distribution. Is invisible light. Further, even if visible light and invisible light are simultaneously irradiated on the image on the object to be inspected, the light wavelengths are different from each other and do not interfere with each other, so that the inspection results of the density distribution and the gloss distribution are not affected. Therefore, the illumination means for density distribution inspection and the illumination means for gloss distribution inspection are turned on at the same time to irradiate the image of the object to be inspected with visible light and invisible light at the same time. Each can be measured. This eliminates the need to sequentially control turning on and off, and since the reading points of the gloss distribution and density distribution are the same because measurement is performed at the same time, it is not necessary to perform image processing for correcting misalignment. Further, since the density distribution and the gloss distribution are simultaneously read, an image pickup device having an operation clock of the same magnification may be used. Therefore, the control device for turning on / off each illumination device, the image processing device, and the high-speed output image sensor are not required, and the cost can be reduced.

  As described above, according to the present invention, it is possible to provide a low-cost image inspection apparatus and image forming apparatus while being able to inspect the density distribution and the gloss distribution with high accuracy over the entire area of the object to be measured.

1 is a schematic diagram illustrating a configuration of an image forming apparatus including an image inspection apparatus according to an embodiment. It is a side view which shows the structure of the image inspection apparatus of this embodiment. It is a front view which shows the structure of the image pick-up element used for the image inspection apparatus of this embodiment. It is a side view which shows the modification of the image inspection apparatus of this embodiment.

Hereinafter, an embodiment of an image forming apparatus to which the present invention is applied will be described in detail with reference to the drawings.
FIG. 1 is a schematic view showing a configuration of an image forming apparatus provided with the image inspection apparatus of the present embodiment. The image forming apparatus 100 shown in FIG. 1 includes the image inspection apparatus 10 according to the present embodiment, and further includes paper feed cassettes 101a and 101b, paper feed rollers 102a and 102b, a controller 103, an optical scanning optical system 104, a photoconductor 105, An intermediate transfer member 106, a fixing roller 107, and a paper discharge roller 108 are included. In such an image forming apparatus 100, the photosensitive member 105 is exposed to the image bearing medium 200 conveyed by the sheet feeding rollers 102a and 102b from the sheet feeding cassettes 101a and 101b by the scanning optical system 104, and a coloring material is applied. The developed image is transferred onto the intermediate transfer member 106 and then from the intermediate transfer member 106. The image transferred onto the image bearing medium 200 is fixed by the fixing roller 107, and the image bearing medium 200 is ejected by the ejection roller 108. An image inspection apparatus 10 according to the present embodiment, which will be described later, is installed at the subsequent stage of the fixing roller 107.

  According to the image forming apparatus 100 having such a configuration, the image bearing medium on which an image is formed by the image inspection apparatus 10 of the present embodiment installed at the subsequent stage of the fixing roller 107 which is a predetermined position of the image forming apparatus 100. The 200 gloss distribution can be inspected with high accuracy, and the density distribution can also be inspected. A high-quality image can be formed on the image bearing medium 200 by feeding back the inspection result of the gloss distribution and the density distribution to the image forming unit.

FIG. 2 is a side view showing the configuration of the image inspection apparatus of the present embodiment. An image inspection apparatus 10 according to this embodiment shown in the figure includes an image sensor 11, an imaging lens 12, a paper feeding device 13, a gloss illumination device 14, and a density illumination device 15. The imaging element 11 is a CCD type or CMOS type imaging element, and in particular, an imaging element of a type that reads in one dimension is used. The imaging lens 12 is an imaging lens that guides reflected light from the reading region 21 from which the image inspection apparatus 10 reads the gloss distribution and density distribution to the image sensor 11. The sheet feeding device 13 moves the inspection object 22 on which the output image is formed in the conveyance direction indicated by arrow A in one direction. The gloss illumination device 14 illuminates the reading area 21 of the inspection object 22 with an incident angle θ ₁ , and the illumination light 14 a is invisible light such as infrared light or ultraviolet light emitted from LED array illumination or the like. It is. Here, the invisible light is light having a wavelength outside the range of 360 [nm] to 830 [nm], and the visible light specifically refers to each light of RGB, and the wavelength is 450 [nm] to 750. [Nm] light. In the illumination light 14 a emitted from the gloss illumination device 14, the incident angle θ ₁ incident on the reading region 21 and the emission angle θ ₂ determined by the imaging element 11 and the imaging lens 12 exactly match. So that it is incident. The illumination light 14a from the gloss illumination device 14 is not parallel light but is directed toward the pupil of the imaging lens 21 when the emitted light that has reached the reading area 21 is regularly reflected.

  Since the surface reflection component, that is, the gloss component of the object does not depend on the wavelength of light, a difference between visible light and invisible light does not occur. On the other hand, the image density component, that is, the component of the light reflected after being transmitted into the object, has a different ratio of absorption depending on the wavelength, so if you want to obtain the density distribution of visible light, replace it with other wavelength light. I can't. Therefore, according to the present embodiment, the concentration illumination device 15 is set at a position where the incident angle and the emission angle with respect to the reading area 21 do not coincide with each other, and is incident on the reading area 21 of the inspection object 22 at a predetermined angle. Irradiate light 15a. The predetermined angle here may be arbitrary as long as it is different from the incident angle θ1, and may be 90 [deg], for example. As the concentration illumination device 15, for example, a diffuse illumination device such as normal xenon lamp illumination or LED array illumination can be used.

  As shown in FIG. 3 to be described later, the image sensor 11 includes an image sensor line 11a that is sensitive only to the invisible light of the gloss illumination device 14, and an image sensor that is sensitive only to the visible light of the density illumination device 15. Line 11b. From the installation position of the gloss illumination device 14, the imaging element line 11 a having sensitivity only to invisible light mainly detects the specular reflection light of the output image, that is, the gloss component, and the illumination light of the concentration illumination device 15 is detected. Unaffected by visible light. On the other hand, the imaging element line 11b having sensitivity only to visible light from the installation position of the density illumination device 15 mainly detects diffuse reflection light of the output image, that is, the image density component. Unaffected by illumination light.

  Each inspection of the gloss distribution and the density distribution in the image inspection apparatus 10 is performed as follows. That is, the image inspection apparatus 10 simultaneously turns on the gloss illumination device 14 and the density illumination device 15 and irradiates the illumination light 14 a and the illumination light 15 a to the reading area 21 of one line. Then, the image sensor 14 acquires the light amounts of the regular reflection light 14 b and the diffuse reflection light 15 b from the reading region 21. Then, the gloss distribution of the reading region 21 and the density distribution of the reading region 21 are inspected based on the acquired light amount of the regular reflection light 14b and the diffused reflection light 15b, respectively. This completes the inspection of the gloss distribution and density distribution of one line (one dimension). Such an inspection is photographed by the image pickup device 11 while sequentially sending the inspection object 22 by the paper feeding device 13, thereby obtaining a density image and a gloss image of the entire image to be measured. The wavelength of the illumination light of the glossy illumination device 14 must first be sensitive to the image sensor 11 and further have no adverse effect on the image equipment, the output image, and the person handling the image device. In general, a CCD or the like has sensitivity to near-infrared light and has a smaller adverse effect on humans than ultraviolet light, so that the near-infrared wavelength is 0.7 [μm] to 2.5 [μm]. Light is desirable.

  FIG. 3 is a front view showing the configuration of the image sensor used in the image inspection apparatus of the present embodiment. In the figure, an image pickup device 11 is an image pickup device line 11a that is sensitive to invisible light of the gloss illumination device 14, and a filter that band-passes invisible light and further cuts visible light is formed on the surface thereof. It is assumed that the imaging device itself has invisible light sensitivity. In addition, the image pickup device 11 is an image pickup device line 11b-R, 11b-G, 11b-B, which is an image pickup device having sensitivity to visible light of the density illumination device 15, and the RGB light (wavelength is 450 [nm] to 750 [ nm]), the density distribution of the color image of the output image can be detected. When the RGB band-pass filter passes invisible light, it is necessary to form a cut filter that does not pass through the imaging element having sensitivity to RGB light. Further, the concentration illumination device 15 emits visible light such as white light, that is, light that does not include invisible light. Thus, the diffuse reflected light 15b emitted from the density illumination device 15 and detected from the object 22 to be inspected is detected only in the RGB imaging element lines 11b-R, 11b-G, and 11b-B. And the illumination light of the glossy illumination device 14 is detected only by the imaging element line 11-a for invisible light by irradiating the illumination device 14 for glossy with light that is invisible light and does not contain white light. become. That is, even if both illumination lights are irradiated simultaneously, each image sensor line can detect the illumination light reflecting the output image without affecting each other.

  FIG. 4 is a side view showing a modification of the image inspection apparatus of the present embodiment. In the figure, the same reference numerals as those in FIG. 2 denote the same components. As shown in the figure, a polarizing filter 31 is installed on the exit side of the glossy illumination device 14, and a polarizing filter 32 is also installed on the front surface of the image sensor line 11a having sensitivity to invisible light. These polarizing filters 31 and 32 are set so that their polarization angles coincide. The illumination light emitted from the gloss illumination device 14 is invisible light, and at the same time becomes a light component having only a certain polarization angle by the action of the polarization filter 31. When this illumination light reaches the toner adhering portion 33 on the object 22 to be inspected, the component of the surface reflected light 34 reflected on the surface, that is, the gloss component does not change the polarization angle of the light, and the imaging element The immediately preceding polarizing filter 32 also passes and is detected by the image sensor line 11a. On the other hand, in the case of the illumination light that reaches the inside of the toner attaching portion 33, the polarization angle of the light of the density component that is the internally transmitted reflected light 35 changes inside the toner attaching portion 33. For this reason, the internal transmitted / reflected light 35 is excluded by the polarization filter 32 installed immediately before the image sensor line 11a in the image sensor 11, so that the density component is not detected.

  As described above, according to the embodiment, as shown in FIG. 2, the gloss illumination device 14 and the density illumination device 15 are turned on at the same time, and the output image is conveyed by the paper feed device 13. The amount of light corresponding to the gloss distribution over the entire area of the inspection object and the amount of light corresponding to the density distribution can be measured simultaneously. In particular, it is necessary to sequentially turn on and off the glossy illumination device and the concentration illumination device in accordance with the operation clock of the image sensor, and for the conventional technology that required a control device for that purpose, In this embodiment, since continuous lighting is sufficient, devices such as blinking control and operation clock synchronization control are not required, and the cost is reduced. Further, in the conventional technology, the acquired image positions of the gloss distribution and the density distribution are shifted by one operation clock in the transport direction. For this reason, image processing for correcting this is necessary, whereas in the present embodiment, since simultaneous reading is performed, image processing for correcting becomes unnecessary. Further, in the conventional method, one image sensor has to be read with twice the operation clock in order to ensure the reading resolution in the conveyance direction for both the density distribution and the gloss distribution. However, in the present embodiment, simultaneous reading is performed. The operation clock of the same magnification may be used, and the image sensor and the operation circuit can be made cheaper.

  In addition, according to the embodiment, as shown in FIG. 3, since the gloss image and the image density can be acquired completely independently and simultaneously, a full color image can be inspected particularly with high accuracy.

  Furthermore, according to the embodiment, as shown in FIG. 4, in the acquisition of the glossy image, illumination light other than the regular reflection component can be cut by the polarizing filters 31 and 32, so that it is not affected by the image density. In particular, the gloss distribution of the image can be inspected with higher quality because it is not affected by the diffuse reflected light that is transmitted and reflected inside the image portion of the image to be inspected.

DESCRIPTION OF SYMBOLS 10 Image inspection apparatus 11 Image pick-up element 11a Image pick-up element line 11b Image pick-up element line 12 Imaging lens 13 Paper feed apparatus 14 Glossy illumination apparatus 15 Density illumination apparatus 21 Reading area 22 Inspected object 31 Polarization filter 32 Polarization filter 33 Toner adhesion Part 34 surface reflected light 35 internally transmitted reflected light 100 image forming apparatus

JP 2006-284550 A JP 2000-123152 A

Claims (5)

Illumination means for density distribution inspection for irradiating the object to be inspected on which an image is formed with illumination light for density distribution inspection, and for gloss distribution inspection for irradiating the inspection object with illumination light before gloss distribution inspection Illumination means, and optical reading means for receiving diffuse reflection light and specular reflection light reflected from the object to be inspected, and the amount of the diffuse reflection light received by the optical reading means and the regular reflection In the image inspection apparatus for inspecting the density distribution and the gloss distribution of the image on the inspection object acquired based on the amount of light,
The illumination means for density distribution inspection irradiates the illumination light for density distribution inspection that is visible light,
The gloss distribution illumination means irradiates the gloss distribution inspection illumination light which is invisible light,
The optical reading unit simultaneously turns on the illumination device for density distribution inspection and the illumination device for gloss distribution and transmits visible light diffusely reflected by the image forming object after passing through the image on the inspection object. A first optical reading unit that receives only the diffusely reflected light and outputs a density distribution based on the amount of the diffusely reflected light; and the invisible light that is regularly reflected from the surface of the image on the inspection object. An image inspection apparatus comprising: a second optical reading unit that receives only regular reflection light and outputs a gloss distribution based on the amount of the regular reflection light. The image inspection apparatus according to claim 1,
The first optical reading means includes an imaging element line in which imaging elements having sensitivity to the diffuse reflection light of the visible light are arranged in a line, and the first optical reading means is provided for each of RGB of the visible light. An image inspection apparatus comprising image pickup element lines for each of RGB in which image pickup elements having sensitivity are arranged in a line. The image inspection apparatus according to claim 2,
The image inspection apparatus, wherein the visible light is white light. The image inspection apparatus according to any one of claims 1 to 3,
A polarizing filter is provided between the gloss distribution illumination unit and the inspection object and between the inspection object and the second optical reading unit, and irradiation is performed from the gloss distribution illumination unit. The polarization angle of each polarizing filter is set so that only the light component reflected from the surface of the inspection object among the illumination light for inspecting the gloss distribution of the invisible light received is received by the second optical reading means. An image inspection apparatus characterized by that.   An image inspection apparatus according to claim 1 is mounted, an image formed on a recording medium is inspected by the image inspection apparatus, and image formation is controlled based on the inspection result. Image forming apparatus.

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