JPH0566381A - Gloss detection device - Google Patents

Abstract

PURPOSE:To detect the degree of gloss on the surface of an object without requiring the adjustment of the thickness and the fitting rotation angle of components corresponding to the variation of a reflecting angle caused by the solid shape of the surface of the object. CONSTITUTION:An irradiating light source 1 for natural light, a collimator lens 2, a polarizer 3 which forms incident light 4 in a linearly polarized state, an analyzer 8 which detects the component of a specified polarized direction in the linearly or the elliptically polarized state of light 6 reflected from the surface of the object 5, an image sensor 10 which detects the image of the reflected light 6 formed by an image forming lens 9, a liquid crystal device 7 which is inserted between the object 5 and the polarizer 3 or the analyzer 8 and which rotates the polarization of the incident light 4 or the reflected light 6, a display device 11 and a gloss detection image processor 12 which are provided on the output side of the sensor 10 and a liquid crystal device driving circuit 13 which is connected between the processor 12 and the device 7 are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for inspecting the appearance of an object surface, and more particularly to a gloss inspection apparatus for detecting the degree of gloss of an object surface having a surface exhibiting metallic luster.

[0002]

2. Description of the Related Art As a conventional device for detecting the appearance of the surface of an object having a metallic luster surface, there is a three-dimensional shape detecting device described in Japanese Patent Laid-Open No. 61-31909, and this device is shown in FIG. And an elliptically polarized light source comprising a polarized laser 101 for irradiating the object 5 with slit-shaped elliptically polarized light, a wave plate 102 and a cylindrical lens 104,
The slit-shaped bright line 105 generated on the target object 5 has only a specific polarization component in a direction different from the irradiation direction,
It is composed of a polarizing plate 8 for detecting the sectional shape of the object 5 and an image detector including a two-dimensional image detector 10.

This device uses the light cutting method to make slit light into an elliptically polarized state by adjusting the attachment rotation angle γ of the polarization laser 101 and the thickness t of the wavelength plate 102 or the attachment rotation angle α, and the polarization plate 8 is attached. By detecting only the polarization component of the slit bright line in a specific direction by adjusting the rotation angle β, the amount of light reflected from the metallic glossy surface can be suppressed to a low level and stable detection of the light cutting line can be performed.

[0004]

SUMMARY OF THE INVENTION Such a conventional method is as follows.
Even when the surface of the target object includes a glossy surface such as a metallic glossy surface, the specular reflection component from the metallic glossy surface can be suppressed to a low level to suppress the effect of gloss and to accurately detect a three-dimensional shape. It is not for detecting the degree of gloss by mainly detecting the light amount of the specular reflection component from the metallic glossy surface of the object. Furthermore, the incident light is made into an elliptically polarized state, and by detecting only the polarized component in a specific direction, the light amount of the specular reflection component of the metallic glossy surface is suppressed to a low level, and the diffuse reflection component is mainly detected. It is necessary to adjust the mounting rotation angle, the polarization laser mounting rotation angle, the polarizing plate mounting rotation angle, etc., especially when the three-dimensional shape of the object surface is different,
Since the reflection angle is different and the direction of the polarization component is also different accordingly, it is necessary to perform the above-mentioned adjustment which is not easy depending on the three-dimensional shape. Therefore, the conventional means does not exhibit a satisfactory function on the surface of a three-dimensional object having different reflection angles.

An object of the present invention is to provide an object having a surface exhibiting a metallic luster, etc. without the need to adjust the thickness of the component and the mounting rotation angle according to the change of the reflection angle due to the three-dimensional shape of the object surface. An object of the present invention is to provide a gloss detecting device that can detect the degree of gloss of the surface and can be used in an appearance inspection device that needs to suppress the influence of gloss.

[0006]

The gloss detection device of the present invention comprises:
A natural light irradiation light source, a collimator lens, a polarizer that forms incident light in a linearly polarized state, and a linearly polarized state or an elliptically polarized light of the reflected light from the surface when the incident light in this linearly polarized state is incident on an object. An analyzer for detecting a specific polarization direction component of the state, an imaging lens provided in the optical path of the reflected light, an image sensor for detecting imaging by the imaging lens, the object and the polarizer, or Inserted between analyzers to rotate the polarization of the incident or reflected light,
Liquid crystal display device (L
CD), a liquid crystal device having a structure in which the polarizer and the analyzer are removed, a display device and a gloss detection image processing device provided on the output side of the image sensor, the gloss detection image processing device and the liquid crystal device And a liquid crystal device drive circuit connected between them.

The structure for achieving the above-mentioned object is provided with a light source 1 for irradiating natural light, a collimator lens 2, and a polarizer 3 as a light source for forming incident light in a linearly polarized state, while one of the object 5 is provided. An analyzer 8 for detecting a specific polarization direction component of the linearly polarized state or the elliptically polarized state of the reflected light from the surface of is inserted into the reflected light path of the object 5, and the reflected light is directed in a direction different from the irradiation direction of the incident light. A liquid crystal display device (LCD) 7 normally used for a display in which an image sensor 10 for forming an image by an image forming lens 9 and detecting the image formation is arranged in the reflected light path to rotate the polarization of incident light or reflected light. The liquid crystal device 7 from which the polarizer and the analyzer having the integral structure in (1) are removed is inserted between the object 5 and the polarizer 3 or the analyzer 8. The analyzer 8 and the image sensor 10 or the liquid crystal device 7 are arranged at positions where the specular reflection component from the surface of the object 5 can be reliably received. Further, a liquid crystal device drive circuit 13 for driving this device is connected to the liquid crystal device 7, and further,
The display device 11 and the gloss detection image processing device 12 are connected to the output side of the image sensor 10, and the gloss detection image processing device 12 is also connected to the input side of the liquid crystal device drive circuit 13.

[0008]

The gloss detecting apparatus retains the polarization of the reflected light or the incident light passing through the liquid crystal device 7 in the linearly polarized state or the elliptically polarized state and rotating the polarized light by 90 ° by turning the liquid crystal device 7 on / off. By detecting the polarization component in the specific direction by the analyzer 8 and the image sensor 10 that pass only the polarization component in the specific direction of the light, the polarization component in the specific direction of the reflected light and the polarization component in the direction orthogonal to this direction are detected. Detects the image of the main object, compares the two detected images, and obtains the light intensity of both images to detect the degree of gloss and obtain an image with the influence of gloss suppressed to a low level. it can.

[0009]

【Example】

(First Embodiment) (Structure): FIG. 1 is a perspective block diagram showing the structure of an embodiment according to the present invention, and FIG. 2 is a structural diagram and an operation explanatory diagram showing details of the liquid crystal device 7 of FIG. ) Is the operation under no electric field, (b) is the state of polarized light passing through the device under no electric field, (c) is the operation under electric field application, (d) is the polarized light passing through the device under electric field application FIG. 3 is a block circuit diagram showing details of the gloss detection image processing device 12 of FIG. 1 respectively showing the states of light.

In FIG. 1, a light source 1 for forming incident light 4 in a linearly polarized state, a collimator lens 2 and a polarizer 3 are provided. As the light source 1, a surface light source, a spot light source, a slit light source, or the like can be used. On the other hand, object 5
Liquid crystal device 7 for rotating the polarization of reflected light 6 in a linear or elliptical polarization state from the surface (such as surface mount parts)
And an analyzer 8 for detecting a specific polarization direction component of the reflected light in which the rotation of the polarization has occurred are inserted in the reflected light path of the object 5, and the reflected light 6 is directed in a direction different from the irradiation direction of the incident light 4. An image is formed by the image forming lens 9 and an image sensor 10 for detecting this image formation is arranged in the reflected light path. The liquid crystal device 7, the analyzer 8 and the image sensor 10 are arranged at positions where the specular reflection component from the surface of the object 5 can be reliably received.

The liquid crystal device 7 is a liquid crystal display device (LC) used for a normal display as shown in FIG.
The configuration is such that the polarizer and the analyzer of the integral structure in D) are removed, and the twist angle of the liquid crystal, that is, the rotation of the polarized light is 90%.
A liquid crystal such as a TN type field-effect type liquid crystal can be used.

That is, as shown in FIG. 2 (a), the liquid crystal device 7 used in this example is provided with two transparent substrates 21, transparent electrodes 22 are adhered inside the transparent substrates 21, respectively. A liquid crystal layer 24 formed by applying a liquid crystal molecule alignment layer 23, providing a sealing material 26 at both ends of the liquid crystal molecule alignment layer 23 to provide a space, and filling the space with a liquid crystal containing liquid crystal molecules 25. The electrode 22
An AC power supply 29 is connected between them so that an electric field can be applied.

As the image sensor 10, in addition to a two-dimensional sensor such as a TV camera and a position sensor using an image pickup tube or a solid two-dimensional image pickup device, a one-dimensional sensor using a linear sensor or a point sensor can be used. it can.

The liquid crystal device 7 is connected to a liquid crystal device drive circuit 13 for driving this device.
Further, a display device 11 such as a TV monitor and a gloss detection image processing device 12 are connected to the output side of the image sensor 10, and the gloss detection image processing device 12 is also connected to the input side of the liquid crystal device drive circuit 13.

As shown in FIG. 3, the gloss detection image processing apparatus 12 controls the entire gloss detection image processing apparatus 12 and outputs a drive signal to the control section 31 connected to each section and the liquid crystal device 7. Liquid crystal drive signal generating circuit 32
An image input circuit 33 for inputting an output signal from the image sensor 10 to output image data, an image memory 34 for inputting and storing the image data, and a smoothing circuit 35 for inputting and smoothing the image data. And an image A buffer memory 36 and an image B buffer memory 37 for inputting smoothed image data, and an image for inputting the image A and B data stored in these two memories 36 and 37 and outputting the result. The A / B subtraction circuit 38, the gloss portion extraction circuit 39 to which the result is input and the extracted gloss portion is output and the comparison reference data memory 40 is connected, and the gloss portion data is input to determine the gloss. The judgment reference data memory 42 is connected to the gloss judgment circuit 41.

(Operation): FIG. 4 is a flow chart of the operation of the present embodiment of the gloss detection image processing apparatus 12 used in the gloss detection apparatus of the present invention. As shown in FIG. 1, the collimator lens 2 collimates the light emitted from the light source, and the incident light 4 linearly polarized by the polarizer 3 has a surface that has a metallic glossy surface (the surface of the object 5). When the electrode part or the lead of the mounted component, the surface of the solder fillet, the land, etc.) is irradiated, the reflection indicating the degree of gloss of the surface of the object 5 is disclosed, as disclosed in the above-mentioned JP-A-61-31909. The specular reflection component of the light 6 becomes a linear polarization state or an elliptically polarization state. In the linear polarization state, there is a difference in the amount of light between the component in the direction of polarization and the component in the direction orthogonal thereto.In the state of elliptically polarized light, the amount of light in the polarization component parallel to the major axis of elliptically polarized light and the elliptically polarized light in the direction orthogonal to this major axis. There is a difference in the amount of light of the polarized component parallel to the short axis of. Further, the intensity or the light amount difference of the polarization component of each direction of the irregular reflection component is smaller than that of the regular reflection component. Therefore, if it is possible to detect the difference between the light amount of the polarized component of the reflected light 6 in the linear or elliptically polarized state in the specific direction and the light amount of the polarized component of the direction orthogonal to this direction, it is possible to detect the light amount of the specular reflected component, that is, the degree of gloss. You can

The liquid crystal device 7 is shown in FIGS.
As shown in (c), when the rubbing direction of the liquid crystal molecular alignment layer 23 on the incident light side is orthogonal to the rubbing direction of the liquid crystal molecular alignment layer 23 on the outgoing light side, the twist angle of the liquid crystal layer 43 is 90 °.
In the case of no electric field as shown in FIG. 2 (b), the polarized incident light 27 rotates its plane of polarization by 90 °, that is, 90 ° rotation of polarized light occurs, and as shown in FIG. That is, when the liquid crystal is driven, nothing acts on the polarized light, and the light passes while maintaining the polarized state.
That is, when the liquid crystal device 7 is turned on / off, the reflected light 6 passing through the liquid crystal device 7 is in a linearly polarized state or an elliptically polarized state.
The polarized light component of the reflected light 6 in the specific direction is detected by the analyzer 8 and the image sensor 10 which retain the polarized light and rotate the polarized light by 90 ° and transmit only the polarized light component of the reflected light 6 in the specific direction. Then, the image of the object 5 whose polarization component in the direction perpendicular to this direction is the main is detected. The detected image is processed by the gloss detection image processing device 12 based on the operation flow shown in FIG. 4, and the degree of gloss of the surface of the object 5 is detected.

The control section 31 first sends a drive-on command for the liquid crystal device 7 to the liquid crystal drive signal generation circuit 32, and the liquid crystal drive signal generation circuit 32 outputs a liquid crystal drive signal to the liquid crystal device drive circuit 13 to turn on the liquid crystal device 7. State.
At this time, the image of the polarization maintaining state of the reflected light 6 is detected by the image sensor 10 and is taken into the image memory 34 via the image input circuit 33. The image thus captured is smoothed by the smoothing circuit 35.
To the image A buffer memory 36, and smoothing is performed to remove noise due to the influence of diffuse reflection components.
(The image stored in this manner will be referred to as image A hereinafter). Next, the liquid crystal device 7 is turned off, and a smoothed image (hereinafter referred to as image B) in which the polarization of the reflected light 6 is rotated by 90 ° at this time is similarly stored in the image B buffer memory 37.

The subtraction circuit 38 between the images A and B obtains the number of pixels having a large density value from the histograms of the images A and B and compares them, and the number of pixels of the image A is larger than that of the image B. If the number is large, the density value of the image B is subtracted for each corresponding pixel. Conversely, if the number of pixels of the image B is larger than the number of pixels of the image A, the number of pixels of the image A is subtracted from the number of pixels of the image B. Then, the image resulting from the inter-image subtraction is output to the glossy portion extraction circuit 39. Here, since the light amount difference between the image A and the image B is obtained by comparing the number of pixels having large density values of the image A and the image B, the number of pixels of the image A and the number of pixels of the image B are almost equal. It is determined that it is not glossy. The glossy portion extraction circuit 39 compares the image of the subtraction result with the data in the comparison reference data memory 40, such as binarization, to obtain the glossy portion extracted image. The gloss determination circuit 41 matches the data in the determination reference data memory 42 with the gloss portion extraction image data by using the pattern matching method, and determines and detects the degree of gloss.

In the above example, the incident light is linearly polarized and the reflected light is linearly polarized or elliptically polarized to detect the degree of gloss, but the incident light is changed so that the reflected light is linearly polarized. With elliptically polarized light, the same result as described above can be obtained.

(Second Embodiment) Next, a second embodiment of the gloss detecting device of the present invention will be described with reference to FIG. The present embodiment is different from the first embodiment only in the following points, and the other points are the same as the above-mentioned embodiments, and thus detailed description thereof will be omitted. (Structure): FIG. 5 is a structural diagram and an operation explanatory diagram showing details of the liquid crystal device 7 of FIG. 1 used in the second embodiment. (A) is an operation when no electric field is applied, and (b) is a device when no electric field is applied. State of polarized light passing through the cells, (c) operation when electric field is applied to the cells 51 and 52, (d) cells 51 and 5
2, the state of polarized light passing through the device when an electric field is applied, (e) the operation when an electric field is applied to both cells 51 and 52, and (f) the device when an electric field is applied to both cells 51 and 52. It is the state of polarized light.

As shown in FIG. 5A, the liquid crystal device 7 has a structure in which a polarizer and an analyzer having an integral structure in a liquid crystal display device (LCD) used for an ordinary display are removed, and the twist angle of the liquid crystal, that is, Polarization rotation 90 ° for π / 2 cell 51 and polarization rotation 240 ° for 4
This is a combination of a π / 3 cell 52, and as the π / 2 cell 51, a field effect type TN liquid crystal or the like is used.
As the / 3 cell 52, a liquid crystal of a field effect type STN system or the like can be used. The detailed description of the structure of these liquid crystal cells is the same as that described in the first embodiment, and will be omitted.

(Operation): FIG. 6 is a flow chart showing the operation of the gloss detection image processing apparatus 12 used in the gloss detection apparatus of this embodiment.

When the angle between the polarization direction of the reflected light 6 from the surface of the object 5 and the polarization direction detected by the analyzer 8 is 45 °, the polarization component of the reflected light 6 in the detection direction of the analyzer 8 and this The difference in the amount of light between the polarized components in the direction perpendicular to the direction is not detected. As shown in FIG. 5, the liquid crystal device 7 of the present embodiment has π /
In the 2 cell 51, the rubbing direction of the liquid crystal molecular alignment layer 23A on the incident light side and the rubbing direction of the liquid crystal molecular alignment layer 23A on the outgoing light side are orthogonal to each other, so that the twist angle of the liquid crystal layer 24A is 90.
5 (a) and FIG. 5 (b), the incident light 27 polarized in the case of no electric field rotates its plane of polarization by 90 °, that is, the polarized light rotates by 90 °. As shown in FIG. 5C and FIG. 5D, when an electric field is applied, that is, when this cell 51 is driven, nothing acts on the polarized light, and the light passes while maintaining the polarized state.

Further, in the 4π / 3 cell 52, since the rubbing direction of the liquid crystal molecule alignment layer 23B on the incident light side and the rubbing direction of the liquid crystal molecule alignment layer 23B on the outgoing light side are 240 °, the twist of the liquid crystal layer 24B is twisted. The angle is 240 °, as shown in Fig. 5.
In the case of no electric field as shown in (a) and FIG. 5 (b), the incident light that is polarized rotates its plane of polarization by 240 °, that is, the polarization is rotated by 240 °, and FIGS. As shown in d), when an electric field is applied, that is, when the cell 52 is driven, nothing acts on the polarized light and the light passes while maintaining the polarized state.

By turning on / off the driving of the cells 51 and 52 of the liquid crystal device 7, the polarization of the reflected light 6 passing through the cells 51 and 52 is maintained, and the polarized light is rotated by 90 ° and 240 °. 6 is detected by the analyzer 8 and the image sensor 10 which pass only the polarization component of the specific direction 6, the polarization component of the reflected light 6 in the specific direction and the right angle to this direction according to the operation flow shown in FIG. The polarization component in the direction is detected when the detection result of the degree of gloss is matte according to the detection image of the object 5, and then the polarization component in the specific direction of the reflected light 6 and the polarization component in this direction and the 240 ° direction are mainly The degree of gloss is detected from the detected image of the target object 5.

(Effect): When the angle between the polarization direction of the reflected light 6 from the surface of the object 5 and the polarization direction detected by the analyzer 8 is 45 ° due to the above action, the degree of gloss of the surface of the object 5 is Can be detected.

(Third Embodiment) Next, a third embodiment of the gloss detecting apparatus of the present invention will be described with reference to FIG. This embodiment is different from the first embodiment in the following points, but other points are the same as the first embodiment, and thus detailed description thereof will be omitted. (Structure): FIG. 7 is a perspective view showing the structure of a third embodiment according to the present invention. As shown in FIG. 7, in this example, the light source 1 that emits natural light
, A collimator lens 2, and a light source for forming incident light 4 in a linearly polarized state or an elliptically polarized state, which includes a polarizer 3, and an object 5 (such as a surface-mounted component), a linearly polarized state or an elliptically polarized state. The liquid crystal device 7 for rotating the polarization of the incident light 4 in the state is inserted. The analyzer 8 and the image sensor 10 are arranged at positions where the specular reflection component from the surface of the object 5 can be reliably received. (Operation): Since the operation of this embodiment is the same as that described in the first embodiment, its detailed description is omitted. (Effect): When the apparatus having the configuration of the present embodiment is used as a commonly used appearance inspection apparatus having no gloss detection function, it is used without operating the liquid crystal device and without being affected by the action of the liquid crystal device. be able to.

(Fourth Embodiment) Next, a fourth embodiment of the gloss detecting device of the present invention will be described with reference to FIG. This embodiment is different from the above embodiment in the following points, and the others are omitted. (Structure): Since the structure itself of this embodiment is the same as that of the other embodiments, its explanation is omitted. (Operation): FIG. 8 is a flow chart of the gloss detection image processing apparatus 12 according to this embodiment.

According to the operation flow shown in FIG. 8, the difference between the light quantity of the polarization component of the reflected light 6 in the linearly polarized state or the elliptically polarized state in the specific direction and the light quantity of the polarized component in the direction orthogonal to this direction is compared, and the light quantity is compared. It is possible to obtain an image in which the influence of the gloss is suppressed to a low level by obtaining an image in which the smaller polarized light component is mainly.

(Effect): The apparatus of the present invention can be used as a visual inspection apparatus that needs to suppress the influence of gloss.

[0032]

As described above, according to the present invention, a metallic luster can be obtained without adjusting the thickness of the component and the mounting rotation angle according to the change of the reflection angle due to the three-dimensional shape of the surface of the object. It is possible to provide a gloss detection device that can detect the degree of gloss of the surface of an object having a surface to be presented and can be used in a visual inspection device that needs to suppress the influence of gloss.

[Brief description of drawings]

FIG. 1 is a perspective block diagram showing the configuration of an embodiment of a gloss detection device of the present invention.

2A is a configuration explanatory view showing the details of the configuration of the liquid crystal device of FIG. 1 and showing the operation in the absence of an electric field, and FIG. 2B is a diagram illustrating the liquid crystal device of FIG. 2A and 2B are operation explanatory views showing a state of polarized light, FIG. 6C is a detailed configuration view of the liquid crystal device shown in FIG. 1, and an operation when an electric field is applied, and FIG. FIG. 7 is an operation explanatory view showing a state of polarized light passing through the device when the electric field is applied.

FIG. 3 is a block circuit diagram showing details of the configuration of the gloss detection image processing apparatus of FIG.

FIG. 4 is a flowchart of the operation of the gloss detection image processing apparatus used in the gloss detection apparatus of the present invention.

5A is a configuration explanatory view showing the details of the configuration of each cell of the liquid crystal device of FIG. 1 in the second embodiment and showing the operation in the absence of an electric field, and FIG. 5B is a diagram in the second embodiment. FIG. 3 is an operation explanatory view showing a state of polarized light passing through the liquid crystal device of No. 1 when there is no electric field, and (c) shows details of the configuration of each cell of the liquid crystal device of FIG. 1 in the second embodiment. FIG. 9 is a configuration explanatory diagram showing an operation at the time of application, and FIG. 7D is an operation explanatory diagram showing a state of polarized light passing through the device at the time of applying an electric field to each cell of the liquid crystal device of FIG. 1 in the second embodiment. , (E) of FIG. 1 in the second embodiment.
FIG. 6B is a structural explanatory view showing the details of the constitution of both cells of the liquid crystal device of FIG. 6A and showing the operation when an electric field is applied, and FIG. 7F is a view of passing through the device when an electric field is applied to both cells of the liquid crystal device of FIG. 1 in the second embodiment. It is an operation explanatory view showing the state of the polarized light to be.

FIG. 6 is a flow chart of the operation of the gloss detection image processing apparatus used in the gloss detection apparatus according to the second embodiment of the present invention.

FIG. 7 is a perspective view showing the configuration of a third embodiment of the gloss detection device of the present invention.

FIG. 8 is a flowchart of a gloss detection image processing device according to a fourth embodiment of the gloss detection device of the present invention.

FIG. 9 is a perspective view showing a configuration of a conventional gloss detection device.

[Explanation of symbols]

 1 Light Source 2 Collimator Lens 3 Polarizer 4 Incident Light 5 Object 6 Reflected Light 7 Liquid Crystal Device 8 Analyzer 9 Imaging Lens 10 Image Sensor 11 Display Device 12 Configuration Detection Image Processing Device 13 Liquid Crystal Device Drive Circuit 21 Transparent Substrate 22 Electrode 23 Liquid crystal molecule alignment layer 24 Liquid crystal layer 25 Liquid crystal molecules 26 Sealing material 27 Polarized transmitted light 28 Polarization plane 29 Electric field application section 31 Control section 32 Liquid crystal drive signal generation circuit 33 Image input circuit 34 Image memory 35 Smoothing circuit 26 Image A buffer Memory 37 Image B buffer memory 38 Image A / B subtraction circuit 39 Gloss section extraction circuit 40 Comparative reference data memory 41 Gloss determination circuit 42 Judgment standard data memory 51 π / 2 cell 52 4π / 3 cell 102 Wave plate 103 Lens 104 Cylindrical Lens 105 Slit line 106 Light-section line extraction 107 Defect detection 108 Substrate surface 109 Table 110 Ball screw 111 Motor

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁵ Identification number Internal reference number FI Technical display location G06F 15/62 380 9287-5L H01L 21/66 J 7013-4M H04N 7/18 B 8626-5C

Claims (1)

[Claims] 1. A natural light irradiation light source, a collimator lens, a polarizer for forming incident light in a linearly polarized state, and a linearly reflected light from the surface of the incident light incident on the object. An analyzer for detecting a specific polarization direction component of a polarization state or an elliptically polarized state, an imaging lens provided in the optical path of the reflected light, an image sensor for detecting imaging by the imaging lens, and the target. A liquid crystal having a structure in which a polarizer and an analyzer having an integral structure in a liquid crystal display device (LCD) used in a normal display, which is inserted between an object and a polarizer or an analyzer to rotate the polarization of the incident light or the reflected light, is removed. A device, a display device and a gloss detection image processing device provided on the output side of the image sensor, and a device between the gloss detection image processing device and the liquid crystal display device. And a liquid crystal device drive circuit connected to the gloss detection device.