Member for detecting defect of transparent body and defect detecting apparatus

Abstract

To efficiently detect a linear flaw on a transparent body 5 to be inspected with high reliability.SOLUTION: The member 4 for defect detection has a defect drawing surface 10 in which a translucent region is formed of a plurality of circular translucent parts 11 and the circular translucent parts 11 are scattered in a non-translucent region 12. The defect drawing surface 10 is arranged between a transparent body 5 to be inspected and a light source 1, the transparent body 5 is irradiated with diffused light from the light source 1 transmitted through the translucent region, and the defect drawing surface 10 is imaged on the side opposite to the defect drawing surface 10 across the transparent body 5. The imaging operation is repeated by relatively moving the defect drawing surface 10 in a fixed direction with respect to the transparent body 5. A defect such as a flaw existing in the transparent body 5 is detected on the basis of image data obtained by imaging.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a defect detection device for detecting defects such as scratches on the surface of a transparent body as an inspection target, and a transparent body defect detection member suitable for the device. [Background technology]

[0002] A known example of this type of defect detection device for transparent bodies is the optically transparent product defect detection device described in Patent Document 1, which was previously proposed by one of the inventors of the present application. Note that the reference numerals in parentheses below are the reference numerals that indicate the components described in Patent Document 1. The flaw detection device described in the document 1 is configured to irradiate diffused light from a flat light source (5) through a filter member (4) onto a light-transmitting film (2) to be inspected, and to have a CCD camera (6) installed on the opposite side of the light-transmitting film (2) from the filter member (4). Here, the filter member (4) has translucent regions (42a) that transmit diffused light and non-translucent regions (42b) that do not transmit the light, which are formed alternately in parallel strips of a predetermined width (see Figure 3 of the same document 1).

[0003] The light-transmitting film (2) to be inspected is moved in a certain direction, and the light-transmitting film (2) is imaged at each moving position by a CCD camera (6), and defects on the light-transmitting film (2) are detected based on the image data obtained by the image capture.

[0004] According to the defect detection device of Patent Document 1, if there is a defect in the light-transmitting film (2) to be inspected, the diffused light that is refracted by the defect and enters the CCD camera (6) is imaged with the non-light-transmitting region (42b) of the filter member (4) as the background, and the image of the defect is clearly depicted in the image data obtained by the image capture. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2020-60491 [Patent Document 2] Patent No. 6732243 Summary of the Invention [Problem to be solved by the invention]

[0006] Although rare, a linear defect may occur in the light-transmitting film 2 to be inspected, extending along the length of the strip-shaped light-transmitting region 42a. In this case, the image of the linear defect is buried between the strip-shaped light-transmitting region 42a and the non-light-transmitting region 42b, making it undetectable.

[0007] Therefore, in the defect detection device of Patent Document 1, although not described in the same document 1, in order to perform reliable defect detection taking into consideration the above-mentioned inconvenience, the filter member (4), in which translucent regions (42a) and non-translucent regions (42b) are formed alternately in a band-like shape, is rotated by 90° with respect to the moving direction of the light-transmitting film (2), and a series of imaging steps using the CCD camera (6) is repeated at least twice.

[0008] The present invention has been made in view of the above circumstances, and has as its object to enable efficient and highly reliable detection of linear flaws on a transparent body to be inspected. [Means for solving the problem]

[0009] In order to achieve the above-mentioned object, the transparent body defect detection component of the present invention is a transparent body defect detection component used to implement a defect detection method in which a defect imaging surface consisting of a light-transmitting region that transmits light and a non-light-transmitting region that does not transmit light is placed between the transparent body to be inspected and a light source, diffused light from the light source that has passed through the light-transmitting region is irradiated onto the transparent body, and the defect imaging surface is imaged on the opposite side of the transparent body from the defect imaging surface, and defects such as scratches present in the transparent body are detected based on the image data obtained by the image capture, and is characterized in that the light-transmitting region is formed by a plurality of circular light-transmitting portions and has a defect imaging surface configured such that circular light-transmitting portions are scattered throughout the non-light-transmitting region.

[0010] Furthermore, the transparent body defect detection member of the present invention can also be configured so that when the defect imaging surface is moved relative to the transparent body in a certain direction, a plurality of circular light-transmitting portions are scattered relative to the non-light-transmitting regions so that the non-light-transmitting regions are positioned relative to the transparent body at the same positions as the circular light-transmitting portions were positioned before the relative movement.

[0011] Furthermore, the transparent body defect detection member according to the present invention can also be configured so that, when the defect imaging surface is moved intermittently relative to the transparent body one or more times at regular intervals in a certain direction, non-light-transmitting regions are placed in relative positions with the transparent body where the circular light-transmitting portions were placed before the relative movement, and circular light-transmitting portions are dotted among the non-light-transmitting regions so that, after a predetermined number of movements, the circular light-transmitting portions are placed in relative positions with the transparent body where the circular light-transmitting portions were placed before the start of the relative movement.

[0012] In addition, the transparent body defect detection device of the present invention is a transparent body defect detection method used to implement a defect detection method in which a defect imaging surface consisting of a light-transmitting area that transmits light and a non-light-transmitting area that does not transmit light is placed between the transparent body to be inspected and a light source, diffused light from the light source that has passed through the light-transmitting area is irradiated onto the transparent body, and the defect imaging surface is imaged on the opposite side of the transparent body from the defect imaging surface, and defects such as scratches present in the transparent body are detected based on the image data obtained by the image capture, and is characterized in that the device comprises a light source that irradiates diffused light, a defect detection member having a defect imaging surface and placed between the transparent body and the light source, and an imaging camera that images the defect imaging surface on the opposite side of the transparent body from the defect imaging member, and the defect detection member is composed of the transparent body defect detection member described above. [Effects of the Invention]

[0013] According to the present invention, the defect detection member is constructed by forming a light-transmitting region from a plurality of circular light-transmitting portions and distributing the circular light-transmitting portions in a non-light-transmitting region, thereby making it possible to efficiently and reliably detect linear defects on a transparent body to be inspected.

[0014] Patent Document 2 discloses a defect detection device previously proposed by one of the inventors of the present application, and also describes a filter member having a plurality of circular through-holes (see Figure 2 in Patent Document 2). However, the filter member in Patent Document 2 has the function of converting diffused light from a light source into a plurality of parallel light beams, while the defect detection member of the present invention, as will be described in detail later, has the function of enabling efficient and reliable detection of linear defects on a transparent body to be inspected. Therefore, the function is completely different from that of the filter member in Patent Document 2, and furthermore, Patent Document 2 does not contain any description suggesting the function performed by the defect detection member of the present invention. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a configuration diagram showing an overview of a transparent body defect detection device according to an embodiment of the present invention; [Figure 2]1A and 1B are diagrams for explaining the configuration and operation of a defect detection member, in which FIG. 1A is an explanatory diagram of the operation when an image of a defect imaging surface is captured by an imaging camera, and FIG. 1B is a plan view showing the defect imaging surface. [Figure 3] 2A and 2B are diagrams for explaining the configuration and operation of the defect detection member, in which (a) is an explanatory diagram of the operation when imaging a defect imaging surface with an imaging camera, and (b) is a plan view showing the defect imaging surface. [Figure 4] 10 is a conceptual diagram showing the relationship between an image of a defect and its background when the defect depiction surface is moved relative to the transparent body. [Figure 5] 4 is a flowchart illustrating an example of each step related to image data acquisition and image processing by the defect detection device according to the embodiment of the present invention. [Figure 6] 5 is a conceptual diagram for explaining an example of each step related to image data acquisition and image processing by the defect detection device according to the embodiment of the present invention. [Figure 7] 1 is a plan view showing an example of the configuration of a defect imaging surface in a defect detection member according to the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. First, an overview of the defect detection device for a transparent body according to this embodiment will be described with reference to FIG. FIG. 1 is a schematic diagram showing an overview of a surface inspection device according to this embodiment. The surface inspection device inspects a transparent body 5 that has the property of transmitting light. The transparent body 5 to be inspected includes those of various shapes, such as a film, a plate, or a block with a curved surface.

[0017] The surface inspection device includes a light source 1 that emits diffused light from a planar light emitting surface, a defect detection member 4, an imaging camera 2, and an image data processing unit 3. The defect detection member 4 is disposed opposite the light emitting surface of the light source 1, and a transparent body 5 to be inspected is disposed on the opposite side of the defect detection member 4 from the light source 1. The structure is such that the diffused light from the light source 1 that has passed through the defect detection member 4 is irradiated onto the transparent body 5. The light source 1 can be configured by arranging a large number of white LEDs on a plane.

[0018] The imaging camera 2 is installed on the opposite side of the transparent body 5 from the defect detection member 4, and captures an image of the surface of the defect detection member 4 through the transparent body 5. A CCD camera, for example, can be used as the imaging camera 2. The image data captured by the imaging camera 2 is sent to the image data processing unit 3 and stored in the memory of the unit. The image data processing unit 3 is composed of, for example, a general-purpose personal computer and a program for processing the image data.

[0019] 2 and 3, the surface of the defect detection member 4 forms a defect imaging surface 10. The defect imaging surface 10 is a flat surface made up of a light-transmitting region 11 that transmits light and a light-opaque region 12 that does not transmit light, and this defect imaging surface 10 is disposed opposite the imaging camera 2 with the transparent body 5 interposed therebetween.

[0020] 2(b), the light-transmitting region 11 is formed of a plurality of circular light-transmitting portions 11. The plurality of circular light-transmitting portions 11 are interspersed with a non-light-transmitting region 12 that does not transmit light, thereby forming a defect imaging surface 10.

[0021] 2(a), the diffused light from the light source 1 passes through the circular light-transmitting portion 11 and is irradiated onto the back surface of the transparent body 5. Since the transparent body 5 has the property of transmitting the diffused light irradiated onto its back surface, the diffused light from the light source 1 also passes through the transparent body 5 and enters the imaging camera 2. As a result, the defect imaging surface 10 of the defect detection member 4 is imaged by the imaging camera 2 through the transparent body 5.

[0022] In this embodiment, the non-light-transmitting regions 12 of the defect imaging surface 10 are colored black to absorb light. Therefore, in an image of the defect imaging surface 10 captured by the imaging camera 2, the non-light-transmitting regions 12 appear black with low brightness, and the circular light-transmitting portions 11, which transmit diffused light, appear white with high brightness. The color of the non-light-transmitting region 12 is not limited to black, and may be formed in a color that clearly depicts the boundary with the circular light-transmitting portion 11, depending on the wavelength of the diffused light emitted from the light source 1. Specifically, when light of a specific wavelength is used for the inspection and the light is visible light, the color of the non-light-transmitting region 12 may be the complementary color (opposite color) of the visible light.

[0023] 3(a), if a defect 5a such as a scratch is present in the transparent body 5 disposed between the defect detection member 4 and the imaging camera 2, diffused light refracted by the defect 5a enters the imaging camera 2. When the diffused light refracted by the defect 5a enters the imaging camera 2 against the background of the non-light-transmitting region 12 of the defect imaging surface 10, an image 5b of the defect 5a is clearly projected in the imaging portion of the non-light-transmitting region 12, as shown in FIG. 3(a). On the other hand, when the diffused light refracted by the defect 5a enters the imaging camera 2 against the background of the circular light-transmitting portion 11 of the defect imaging surface 10, the luminance of the diffused light that has transmitted through the circular light-transmitting portion 11 and the luminance of the diffused light refracted by the defect 5a are approximately the same value, and therefore the image 5b of the defect 5a blends into the image of the circular light-transmitting portion 11 and is not clearly visualized.

[0024] Therefore, by moving the defect imaging surface 10 relative to the transparent body 5 in a certain direction and capturing images of the defect imaging surface 10 at multiple relative movement positions, even if the background of the diffused light refracted by the defect 5a becomes a circular light-transmitting portion 11 at one relative movement position, the background of the diffused light refracted by the defect 5a becomes a non-light-transmitting region 12 at another relative movement position, thereby obtaining an image 5b of the defect 5a.

[0025] Furthermore, it is preferable that the non-light-transmitting regions 12 and the circular light-transmitting portions 11 are arranged on the defect imaging surface 10 so as to satisfy the following condition: That is, when the defect imaging surface 10 is moved relative to the transparent body 5 in a certain direction, the plurality of circular light-transmitting portions 11 are scattered relative to the non-light-transmitting regions 12 so that the non-light-transmitting regions 12 are positioned relative to the transparent body 5 at the positions where the circular light-transmitting portions 11 were positioned before the relative movement.

[0026] In this embodiment, the defect imaging surface 10 is moved relative to the transparent body 5 in one direction parallel to the defect detection surface 10. Specifically, this can be achieved by moving the defect detection member 4 as shown by the solid arrow in Fig. 1, or by moving the transparent body 5 in the opposite direction as shown by the dashed arrow in Fig. 1. Furthermore, the defect detection member 4 and the transparent body 5 may be moved separately as necessary. Preferably, the defect imaging surface 10 is fixed relative to the light source 1, and the transparent body 5 is moved, so that the diffused light transmitted through the circular light-transmitting portion 11 can be irradiated onto the transparent body 5 from the same position, and the photographing conditions are fixed. Note that even if the photographing conditions change, they can be adjusted by image processing using the image data processing unit 3.

[0027] According to the defect detection principle of the present invention, the closer defect 5a is to circular light-transmitting portion 11 as viewed from imaging camera 2, the shorter the distance that diffused light that has passed through circular light-transmitting portion 11 must travel to reach defect 5a, and therefore the higher the brightness of the diffused light that is refracted by defect 5a and enters imaging camera 2. Even if circular light-transmitting portion 11 and defect 5a are far apart as viewed from imaging camera 2, they can be brought closer together by moving transparent body 5 and defect detection surface 10 relative to each other, so that a bright image 5b of defect 5a can be obtained.

[0028] FIG. 4 is a conceptual diagram showing the relationship between the image of a defect and its background when the defect imaging surface is moved relative to the transparent body. As shown in (a-1), (b-1), and (c-1) in the figure, it is assumed that there is a linear flaw (defect 5a) on the transparent body 5, and the defect imaging surface 10 is moved relative to the transparent body 5 from the state shown in (a-1) to the state shown in (b-1) in the figure, and then moved relative to the transparent body 5 from the state shown in (b-1) to the state shown in (c-1). The direction of the relative movement is a fixed direction.

[0029] Figures (a-2), (b-2), and (c-2) conceptually show the positional relationship between the image (i.e., image 5b of defect 5a) rendered by diffused light that is refracted by defect 5a and enters the imaging camera 2 when the defect rendering surface 10 is imaged at each relative movement position, and its background.

[0030] In FIG. 1(a-2), a portion of image 5b of defect 5a overlaps circular light-transmitting portion 11 and is not rendered, while the other portion is clearly rendered against the background of non-light-transmitting region 12. In FIG. 1(b-2), one end of image 5b of defect 5a slightly overlaps circular light-transmitting portion 11 and is not rendered, but most of defect 5a is rendered against the background of non-light-transmitting region 12. In FIG. 1(c-2), a portion of image 5b of defect 5a overlaps circular light-transmitting portion 11 and is not rendered, while the other portion is clearly rendered against the background of non-light-transmitting region 12. The portion of image 5b of defect 5a rendered in FIG. 1(c-2) includes the portion that overlaps circular light-transmitting portion 11 and is not rendered in FIG. 1(a-2).

[0031] Here, in the same figure (b-2), most of the defect 5a is depicted with the non-transparent region 12 as the background, but the light that is refracted by the defect 5a and diffused in irregular directions forms an image in the non-transparent region 12, but since the amount of light is very weak, there is a risk that the image 5b of the defect 5a will be blurred using only this image data 20.

[0032] However, by superimposing the images 5b of the defect 5a obtained at the relative movement positions in (a-2) and (c-2) of the same figure, it is possible to obtain clear image 5b data of the defect 5a. The defect detection member 4 of this embodiment is intended to form a defect imaging surface 10 by dotting circular light-transmitting portions 11 in a non-light-transmitting region 12, thereby dividing and drawing an image 5b of a defect 5a, and then overlaying the divided images to obtain a clear image 5b of the defect 5a. This eliminates the need to change direction and move relative to the transparent body 5 as in the prior art, and makes it possible to efficiently and reliably detect defects 5a (especially linear scratches) on the transparent body 5 simply by moving the defect imaging surface 10 relative to the transparent body 5 in a fixed direction and obtaining image data 20.

[0033] FIG. 5 is a flowchart for explaining an example of each step related to the acquisition of image data and image processing by the defect detection device, and FIG. 6 is a conceptual diagram of a defect imaging surface in the same manner. Each processing step for inspecting the transparent body 5 for defects 5a will be described with reference to these figures.

[0034] 1 also functions as a control unit that controls the light source 1, the relative movement of the defect detection member 4 with respect to the transparent body 5 (specifically, the movement of the transparent body 5), and each component of the imaging camera 2. Therefore, each processing step described below is executed by the image data processing unit 3 and the personal computer that functions as a control unit.

[0035] First, as shown in Fig. 1, a transparent body 5 to be inspected is placed between the defect detection member 4 and the imaging camera 2, and an image of the defect imaging surface 10 of the defect detection member 4 is captured through the transparent body 5. Then, the image data 20 is stored in the image data processing unit 3 (step S1 in Fig. 5, (a-1) in Fig. 6). The acquired image data 20 depicts the non-transparent region 12 and the circular transparent portion 11 of the defect depicting surface 10, and an image 5b of a defect 5a such as a flaw present in the transparent body 5.

[0036] Next, a reference image 21 is created for the acquired image data 20 (step S2 in FIG. 5, (b-1) in FIG. 6). The reference image 21 is image data in which only the defect imaging surface 10 in the same state as the acquired image data 20 is depicted. Although the reference image 21 can be created by placing a transparent body 5 without a defect 5a and capturing an image, in this embodiment, the reference image 21 is created by using a known image processing technique called morphology to erase the image 5b of the defect 5a from the image data 20 acquired in step S1.

[0037] Next, the image data 20 acquired in step S1 is subjected to subtraction processing using the reference image 21 created in step S2, and only the image 5b of the defect 5a depicted in the image data 20 is extracted (step S3 in Figure 5, (c-1) in Figure 6).

[0038] The process from obtaining the image data 20 to subtracting the image data 20 (steps S1 to S3 in FIG. 5) is performed by moving the defect imaging surface 10 relative to the transparent body 5 at each relative movement position (step S4 in FIG. 5, (a-2)(b-2)(c-2) and (a-3)(b-3)(c-3) in FIG. 6).

[0039] In the example shown in Figure 6, the defect imaging surface 10 is moved relative to the transparent body 5 in a certain direction twice, and image data 20 is acquired at three relative movement positions including the initial imaging position, and only image 5b data of the defect 5a is extracted from each image data 20 ((c-1) (c-2) (c-3) in Figure 6).

[0040] Next, the image data 20 captured at each of these relative movement positions are superimposed to obtain clear image 5b data of the defect 5a (step S5 in FIG. 5, (d) in FIG. 6). Furthermore, by performing binary processing on the image 5b data of the defect 5a formed in step S6, the image 5b of the defect 5a can be depicted more clearly (step S6 in FIG. 5, (e) in FIG. 6). Also, if necessary, other image processing can be performed to clarify the image 5b of the defect 5a (step S7 in FIG. 5).

[0041] In this way, a clear image of the defect 5a present in the transparent body 5 can be obtained, making it possible to appropriately evaluate and deal with the defect 5a.

[0042] FIG. 7 is a plan view showing an example of the configuration of the defect imaging surface in the defect detecting member of the present invention. The defect detection member 4 is configured so that, when the defect imaging surface 10 is moved intermittently relative to the transparent body 5 in a certain direction at certain intervals one or more times, the non-light-transmitting regions 12 are positioned relative to the transparent body 5 at the positions where the circular light-transmitting portions 11 were positioned before the relative movement. Furthermore, it is preferable to configure the circular light-transmitting portions 11 to be scattered relative to the non-light-transmitting regions 12 so that, after a predetermined number of movements, the circular light-transmitting portions 11 are positioned relative to the transparent body 5 at the positions where the circular light-transmitting portions 11 were positioned before the relative movement began.

[0043] The defect imaging surface 10 shown in (a-1) of Figure 7 is configured such that the circular light-transmitting portions 11 are scattered relative to the non-light-transmitting region 12 by performing three relative movements intermittently in a certain direction at certain intervals (the intervals indicated by the arrows in the figure), so that the circular light-transmitting portions 11 after the relative movement are positioned relative to the transparent body 5 where the circular light-transmitting portions 11 were positioned before the relative movement began. That is, the circular light-transmitting portion 11 at the position indicated by the symbol "1" in (a-1) moves to the position indicated by the symbol "2" in (a-2) by the first relative movement, and then moves to the position indicated by the symbol "3" in (a-3) by the second relative movement. Then, the circular light-transmitting portion 11 returns to the position indicated by the symbol "1" in (a-1) by the third relative movement.

[0044] In addition, the defect imaging surface 10 shown in (b-1) of Figure 7 is configured so that by performing two relative movements intermittently in a certain direction at certain intervals (the interval between the arrows in the figure), the circular light-transmitting portions 11 are scattered relative to the non-light-transmitting region 12 so that the circular light-transmitting portions 11 after the relative movement are positioned relative to the transparent body 5 where the circular light-transmitting portions 11 were positioned before the relative movement began. That is, the circular light-transmitting portion 11 at the position indicated by the symbol "1" in (b-1) moves to the position indicated by the symbol "2" in (b-2) by the first relative movement, and then returns to the position indicated by the symbol "1" in (b-1) by the second relative movement.

[0045] The present invention is not limited to the above-described embodiment, and it goes without saying that various modifications and variations are possible as required. For example, in (a-1) of Figure 7, an arrangement pattern is formed in which the circular light-transmitting portion 11 returns to its original position after three relative movements, and in (b-1) after two relative movements, but any arrangement pattern can be formed as long as the configuration involves one or more relative movements. If only one relative movement is required, the amount of data to be acquired and stored is small, and image data can be processed quickly. On the other hand, the more times image data is acquired (the number of relative movements), the higher the scan density becomes, which has the advantage of enabling even minute defects 5a to be precisely depicted. [Explanation of symbols]

[0046] 1:Light source 2: Imaging camera 3: Image data processing unit 4: Defect detection components 5: Transparent body 5a: Defects (flaws) in transparent bodies 5b: Image of the defect 10: Defect visualization surface 11: Circular transparent part (transparent area) 12: Non-transparent area 20: Image data 21: Reference image

Claims

1. a defect imaging surface including a light-transmitting region that transmits light and a non-light-transmitting region that does not transmit light, is disposed between the transparent body to be inspected and the light source; A defect detection component for a transparent body used to implement a defect detection method, which includes irradiating the transparent body with diffused light from the light source that has passed through the light-transmitting region, capturing an image of the defect imaging surface on the opposite side of the transparent body from the defect imaging surface, and detecting defects such as flaws that exist in the transparent body based on image data obtained by capturing the image, A component for detecting defects in a transparent body, characterized in that the light-transmitting region is formed by a plurality of circular light-transmitting portions, and the defect imaging surface is configured so that the circular light-transmitting portions are scattered across the non-light-transmitting region.

2. 2. A defect detection member for a transparent body according to claim 1, wherein the plurality of circular light-transmitting portions are interspersed with the non-light-transmitting regions so that, when the defect imaging surface is moved relative to the transparent body in a certain direction, the non-light-transmitting regions are positioned relative to the transparent body at positions where the circular light-transmitting portions were positioned before the relative movement.

3. 3. The defect detection member for a transparent body according to claim 2, wherein the circular light-transmitting portions are interspersed with the non-light-transmitting portions so that, when the defect imaging surface is moved intermittently relative to the transparent body one or more times at constant intervals in a constant direction, the non-light-transmitting regions are disposed at relative positions with the transparent body where the circular light-transmitting portions were disposed before the relative movement, and the circular light-transmitting portions, after the relative movement, are disposed at relative positions with the transparent body where the circular light-transmitting portions were disposed before the start of the relative movement, for a predetermined number of movements.

4. a defect imaging surface including a light-transmitting region that transmits light and a non-light-transmitting region that does not transmit light, is disposed between the transparent body to be inspected and the light source; A transparent body defect detection device used to implement a defect detection method that irradiates the transparent body with diffused light from the light source that has passed through the light-transmitting region, captures an image of the defect imaging surface on the opposite side of the transparent body from the defect imaging surface, and detects defects such as scratches that exist in the transparent body based on image data obtained by capturing the image, a light source that emits diffused light; a defect detection member having the defect imaging surface and disposed between the transparent body and the light source; an imaging camera that images the defect imaging surface on the opposite side of the transparent body from the defect imaging member, 4. A transparent body defect detection device, wherein the defect detection member is constructed from the transparent body defect detection member according to claim 1.

Images