Line camera viewpoint adjustment reference sample, uniform viewpoint adjustment device, and uniform viewpoint adjustment method

Abstract

To simply and efficiently adjust the viewpoints of a plurality of line cameras in an inspection device using a diffuse transmission optical system. [Solution] A line camera viewpoint adjustment reference sample having a plurality of parallel grooves with arc-shaped cross sections and different arc widths, the grooves being the same depth and vertical grooves, a uniform viewpoint adjustment device and a uniform viewpoint adjustment method using the line camera viewpoint adjustment reference sample, are provided, making it possible to easily determine that multiple line cameras are at the same degree of adjustment.

Description

[Technical field]

[0001] The present invention relates to a uniform viewpoint adjustment device and method for adjusting the viewpoint of multiple line cameras in a diffuse transmission optical system when inspecting for defects in a translucent object such as a film or sheet, and to a line camera viewpoint adjustment reference sample and a uniform viewpoint adjustment method for eliminating variations when implementing a line sensor using the viewpoint adjustment reference sample. [Background technology]

[0002] Transparent defects such as unevenness, fish eyes, etc. occur in light-transmitting objects to be inspected, such as films. In order to inspect for such defects, an inspection device with a diffuse transmission optical system irradiates a line of light from a light source, and irradiates a moving object to be inspected with a slit light, the spread of which is limited by a slit.

[0003] Here, the term "diffuse transmission optical system" refers to an optical system in which a slit is inserted to reduce the variation in the direction in which light travels, and which has the characteristic of emphasizing the refraction of light when it hits an uneven defect. In contrast, a regular transmission optical system refers to an optical system in which no slit is inserted and all light from the light source is applied, and in which the refraction of light is difficult to see even when the light hits an uneven defect. For this reason, defects may not be found when inspecting with a regular transmission optical system.

[0004] A number of line cameras are arranged in a line facing the light source across the object to be inspected, and capture the light that passes through the moving object to be inspected. The presence or absence of defects in the object to be inspected is determined based on the image data output from these line cameras, and if a defect is detected, the position, shape, etc. of the defect are identified.

[0005] For this reason, it is necessary to implement multiple line cameras, and depending on the line camera sensor, there may be individual variations, so it is necessary to adjust them to a uniform and identical degree of adjustment, and the line cameras are adjusted so that the degree of adjustment is the same detection level.

[0006] For example, if the position of the line camera is misaligned when installing or using the inspection device, the detection level may change, making it difficult to perform uniform detection.

[0007] Furthermore, in order to easily grasp the positional misalignment of the line camera, in Patent Document 1, the position of the light source is adjusted, and whether or not the position of the line sensor camera is appropriate is judged based on the output value of the line sensor camera at each position, and if the position of the line sensor camera is not appropriate, the worker adjusts the positions of the light source and the line sensor camera. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Patent No. 6459026 Summary of the Invention [Problem to be solved by the invention]

[0009] In the above-mentioned inspection device, in order to check the sensitivity of the inspection device, an actual defect is placed at the scanning position, the inspection waveform is measured using an oscilloscope or the like, and the S / N and signal level are measured. The light source is then moved and its position is adjusted to determine whether the line sensor camera is misaligned, and the position of the line sensor camera is adjusted based on the determination.

[0010] For this reason, particularly when a large number of actual machines are installed, the edge amount is calculated by simply calculating the ratio of the sensor position setting to the output value, and there is no indicator to serve as a guide for adjustment, which means that adjustment takes a long time.

[0011] In addition, because it is based only on the amount of received light, the adjustment is prone to variation and may not be performed properly. For this reason, it is difficult to adjust uniformly when using multiple line cameras.

[0012] It is necessary to search for defects that emit a light intensity close to the threshold in actual inspection, and it is unclear whether the defects searched for will necessarily emit a standard amount of light. Since adjustments must be made by trial and error, there is a problem in that it is not possible to efficiently adjust the viewpoints of multiple line cameras.

[0013] Therefore, the present invention aims to provide a line camera viewpoint adjustment reference sample that can easily perform adjustment on an actual device when uniformly adjusting the viewpoint of multiple line cameras in a diffuse transmission optical system, and a viewpoint adjustment device and uniform viewpoint adjustment method using the viewpoint adjustment reference sample.

[0014] Another object of the present invention is to provide a viewpoint adjustment reference sample and a uniform viewpoint adjustment device and method using the viewpoint adjustment reference sample, which enable easy viewpoint adjustment of multiple line cameras with individual variations when designing, inspecting, installing, implementing, and maintaining the inspection device.

[0015] In addition, the present invention also aims to provide a reference sample for adjusting the viewpoint of a line camera, and to provide a uniform viewpoint adjustment device and a uniform viewpoint adjustment method for a line camera that use the reference sample for adjusting the viewpoint of the line camera to determine the degree of adjustment based on the light quantity waveform. [Means for solving the problem]

[0016] In order to achieve the above object, the first invention is: A rectangular flat plate made of a colorless and transparent acrylic resin, in which a plurality of grooves are provided in parallel from one end to the other end of a long side of the flat plate, the cross sections of the plurality of grooves are arc-shaped, the cross sections are parallel to a plane perpendicular to the extension direction of the grooves, the widths of the arcs of the plurality of grooves are different, and the depths of the plurality of grooves are the same. The line camera viewpoint adjustment reference sample was used.

[0017] In addition, as a second invention, there is provided an inspection device having a line-shaped light source that irradiates light onto a translucent inspection object, a number of line cameras that are arranged in a line facing the light source across the inspection object and capture the light that passes through the moving inspection object, and a slit that cuts off the spread of light from the light source, and which is a line camera uniform viewpoint adjustment device that uses a line camera viewpoint adjustment reference sample to determine the degree of adjustment of the viewpoints of the multiple line cameras.

[0018] As a third aspect of the present invention, a uniform viewpoint adjustment device for a line camera is provided, in which a viewpoint adjustment reference sample for the line camera is installed at a work position at an angle with respect to the moving direction of an object to be inspected.

[0019] As a fourth invention, a uniform viewpoint adjustment device for a line camera is provided, which is provided with an installation jig for installing a viewpoint adjustment reference sample for the line camera at a work position at an angle with respect to the moving direction of an object to be inspected.

[0020] In addition, as a fifth invention, there is provided an inspection device having a line-shaped light source that irradiates light onto a translucent inspection object, a number of line cameras that are arranged in a line facing the light source across the inspection object and capture the light that passes through the moving inspection object, and a slit that cuts off the spread of light from the light source, and a method for uniformly adjusting the viewpoint of a line camera that uses a viewpoint adjustment reference sample for the line camera to adjust the adjustment degree of the viewpoint of the multiple line cameras.

[0021] Furthermore, as a sixth invention, there is provided an inspection device having a line-shaped light source which irradiates light onto a translucent inspection object, a number of line cameras which are arranged in a line facing the light source across the inspection object and which capture the light which passes through the moving inspection object, and a slit which cuts off the spread of light from the light source, and a method for uniformly adjusting the viewpoint of a line camera which uses a reference sample for adjusting the viewpoint of the line camera to measure the waveform of the amount of light received by each of the multiple line cameras and adjust the degree of adjustment of the viewpoint of the line camera. Effect of the Invention

[0022] According to the present invention, by using a reference sample for adjusting the viewpoint of the line camera, the viewpoints of a plurality of line cameras can always be adjusted based on the same reference.

[0023] Furthermore, by grasping the degree of adjustment of the line cameras when the inspection device is designed and adjusting the viewpoints of the multiple line cameras when the device is set up, the multiple line cameras can be adjusted to the same performance without variation. Furthermore, by easily adjusting the viewpoints of the multiple line cameras to the same state during periodic inspection of the inspection device, when the inspection device is installed at the installation site, and during maintenance after a certain period of time has passed, the inspection accuracy of the inspection device can be maintained at the same level and the reliability of the inspection device can be improved.

[0024] Furthermore, the present invention can provide a uniform viewpoint adjustment device and a uniform viewpoint adjustment method for a line camera, which uses a viewpoint adjustment reference sample of the line camera to determine the adjustment degree based on a light quantity waveform. [Brief description of the drawings]

[0025] [Figure 1] FIG. 2 is a perspective view of a reference sample for adjusting the viewpoint of the line camera of the present invention; [Diagram 2] A cross-sectional view of a groove of a reference sample for adjusting the viewpoint of a line camera according to the present invention. [Diagram 3] FIG. 1 is a diagram showing a schematic configuration of an inspection device according to an embodiment of the present invention; [Figure 4] Plan view showing the positional relationship between multiple line cameras and light sources [Diagram 5] Plan view of the reference sample for adjusting the viewpoint of the line camera installed at the work position [Figure 6] FIG. 13 shows the output waveform when inspecting a reference sample for adjusting the viewpoint of a line camera. [Figure 7] FIG. 13 is a diagram showing an example of an output waveform when inspecting an actual machine on which a reference sample for adjusting the viewpoint of a line camera is installed. [Figure 8] FIG. 13 is a diagram showing an example of an output waveform when inspecting an actual machine on which a reference sample for adjusting the viewpoint of a line camera is installed. [Figure 9] FIG. 1 is a plan view showing an installation jig for installing a reference sample for adjusting the viewpoint of a line camera; [Figure 10]A front view showing an installation jig for installing a reference sample for adjusting the viewpoint of the line camera. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] (Line camera viewpoint adjustment reference sample) A reference sample for adjusting the viewpoint of the line camera of the present invention will be described.

[0027] FIG. 1 is a perspective view of a reference sample for adjusting the viewpoint of a line camera of the present invention, and FIG. 2 is a cross-sectional view of a groove of the reference sample for adjusting the viewpoint of a line camera of the present invention.

[0028] In Fig. 1, 1 is a reference sample for adjusting the viewpoint of a line camera of the present invention. 2, 3, and 4 are grooves provided on the reference sample for adjusting the viewpoint of a line camera 1. These grooves 2, 3, and 4 are grooves that have arc-shaped cross sections with different arc widths, are provided parallel to each other, have the same depth, and are vertical grooves.

[0029] For example, the present embodiment shows a line camera viewpoint adjustment reference sample 1 made of acrylic resin (colorless and transparent) (length 50 mm, width 70 mm), groove 2 has a width of 20 mm, groove 3 has a width of 10 mm, and groove 4 has a width of 5 mm, and the depth of each of grooves 2, 3, and 4 is 5 mm.

[0030] There is no particular restriction on the size of the line camera viewpoint adjustment reference sample, and the width and depth of the groove are not limited to these either.

[0031] However, by making the widths of at least grooves 2, 3, and 4 different, the peak values ​​of the light quantity waveform (contrast difference, brightness difference, and intensity difference) can be clearly detected. Based on these contrast differences, the degree of viewpoint adjustment of the line camera can be adjusted.

[0032] In addition, it becomes possible to adjust the position of the slit together with adjusting the viewpoint of the line camera.

[0033] Moreover, by making the depths of the grooves 2, 3, and 4 the same, the peak value of the light quantity waveform can be changed according to the difference in the width of the grooves.

[0034] In the present embodiment, the width of the groove is as follows: Groove 2>Groove 3>Groove 4 Therefore, the peak value of the light intensity waveform is The peak value of the groove 2 portion < the peak value of the groove 3 portion < the peak value of the groove 4 portion.

[0035] In general, the peak value of a groove with a large width is smaller than the peak value of a groove with a small width.

[0036] (Outline of the inspection device) Here, an overview of the inspection device will be given.

[0037] FIG. 3 is a diagram showing a schematic configuration of an inspection device according to an embodiment of the present invention, and FIG. 4 is a plan view showing the positional relationship between a plurality of line cameras and a light source.

[0038] In Fig. 3, reference numeral 5 denotes an object to be inspected, which is a light-transmitting film, sheet, etc. The object to be inspected 5 moves from left to right as shown by the arrow in Fig. 3.

[0039] A light source 6 emits light, a line camera 7, and a slit 8.

[0040] As shown in Figure 3, this inspection device has a line-shaped light source 6 that irradiates light onto a translucent inspection object 5 such as a film or sheet, a number of line cameras 7 that are arranged in a line facing the light source 6 across the inspection object 5 and capture the light that passes through the moving inspection object 5, and a slit 8 that cuts off the spread of light from the light source 6.

[0041] The slit 8 has an edge at its tip. The intensity of the diffuse transmission can be changed by adjusting the width of the slit 8, which greatly changes how defects are captured.

[0042] The light source 6 is an LED, a fluorescent lamp, a halogen lamp, or the like, and is attached to the case 9 and arranged in the longitudinal direction perpendicular to the moving direction of the inspection object 5. The case is stored and fixed in a cabinet (not shown). The lighting of the light source 6 is controlled, and light is irradiated toward the inspection object 5 moving above.

[0043] A slit 8 having a knife-edge tip is disposed in the longitudinal direction above the light source 6 so as to cover part of the light source 6. When viewed from above, the slit 8 covers the downstream half of the light source 6 in the direction of movement of the object 5 to be inspected.

[0044] As a result, part of the light emitted from the light source 6 is cut by the slit 8, forming a diffuse transmission optical system. In this optical system, the insertion of the slit 8 reduces the variation in the direction in which the light travels, emphasizing the refraction of the light when it hits a defect with unevenness. Therefore, defects are clearly visible, making it suitable for detecting defects such as unevenness and fisheyes.

[0045] A portion of the light from the light source 6 is cut off by the slit 8, and the uncut light passes through the moving object under inspection 5. The light that passes through the object under inspection 5 is captured by the line camera 7, and an image of the object under inspection 5 is captured. If there is a defect in the object under inspection 5, the transmitted light is scattered, causing a change in the amount of light received by the line camera 7. The line camera 7 outputs image data of the object under inspection 5 that has been captured.

[0046] The line camera 7 is, for example, a CCD camera or a CMOS camera. A plurality of line cameras 7 are arranged above the light source 6, and the line cameras 7 are aligned in a row in the longitudinal direction and attached to a pedestal 10. The pedestal 10 is housed in a cabinet and movably attached. To adjust the viewpoint position of the line camera 7, a viewpoint position adjustment sample 1 is used.

[0047] In the inspection device, the detection level must be kept constant in order to reliably and stably detect defects in the object 5. For this reason, the line camera 7 is adjusted and maintained at the same level. Since multiple line cameras 7 are installed, each line camera 7 needs to be adjusted.

[0048] As shown in Fig. 5, at the work position where the moving object under test 5 passes, the viewpoint position adjustment sample 1 is set so as to be inclined with respect to the moving direction of the object under test 5. Grooves 2, 3, and 4 face each other at an angle with respect to the longitudinal direction of the light source 6.

[0049] The inclination angle is set to 5° to 30°, and is preferably set to about 10°. The inclination angle can be adjusted as appropriate.

[0050] When light source 6 emits light in this state, the light restricted by slit 8 hits grooves 2 , 3 and 4 and is refracted, and the light that passes through viewpoint position adjustment sample 1 is captured by line camera 7 .

[0051] In detail, in FIG. 5, the contact point between the edge of the slit 8 and the light source 6 and the viewpoint adjustment sample 1 of the line camera of the present invention is A, I, U, E, O, Ka, Ki, Ku As shown in Fig.

[0052] Each point indicates the following part in the sample of the line camera viewpoint position adjustment of the present invention.

[0053] A-B Flat area A-U Arc portion of groove 2 U-E Flat area A-O Arc section of groove 3 Oka flat area Khaki Arc section of groove 4 Key Flat part 6 shows the output waveform of the light amount along the scan line in the output data. Three peak values ​​of the output waveform appear corresponding to the three grooves 2, 3, and 4. At positions corresponding to the vicinity of the edges on both sides of grooves 2, 3, and 4, the minimum peak of the darkest part or the maximum peak of the brightest part is obtained. Since the waveform height of the peak is greater than the waveform height of the minimum peak, it is preferable to manage the adjustment condition based on the maximum peak value of the viewpoint position adjustment sample 1.

[0054] Figure 6 shows the output waveform (contrast) when inspecting a line camera viewpoint adjustment reference sample, and shows the amount of light received by the line camera at each of the points (A, B, C, D, E, F, G, H).

[0055] The peak value at point K is indicated as 100%.

[0056] By adjusting multiple line cameras so that the output waveforms (contrast) of the received light amounts are the same, this serves as an index for determining whether the line cameras have been adjusted to have the same performance.

[0057] (1. Adjustments at the time of setting standards) First, during a reference inspection of the inspection device, the output waveform of the amount of received light is adjusted and measured.

[0058] Based on this output waveform, the position of the line camera 7 is adjusted using the viewpoint position adjustment sample 1 at the time of shipment, installation, and maintenance of the inspection device.

[0059] Furthermore, when the inspection device is shipped, installed, or maintained, the line camera is adjusted so that the waveform of the amount of received light during inspection is the same as that during inspection.

[0060] That is, when inspecting a new inquiry, the viewpoint adjustment reference sample 1 of the line camera of the present invention is used to reliably obtain the output waveform of the amount of received light.

[0061] This test is repeated to check the reproducibility of the output waveform of the amount of received light, and basic test data is obtained for adjusting multiple line cameras so that they have a uniform viewpoint.

[0062] In order to adjust the line camera, a precision stage is attached to the camera base 10 in advance.

[0063] In order to adjust the position of the line camera 7, a moving unit is provided on the base 10 of the line camera 7, for example an electric stage such as a precision stage, and the moving unit is operated by a command signal from the adjustment unit to fine-tune the position of the base 10.

[0064] The position of the base 10 may be manually fine-tuned using a manual stage.

[0065] (2. Factory Adjustment) Next, at the time of shipment of the actual machine, the line camera viewpoint adjustment reference sample 1 is placed at the work position where the inspected object 5 is located so that the line camera viewpoint adjustment reference sample 1 is tilted relative to the direction of movement, and inspection is performed. The test data obtained by capturing the transmitted light through the line camera viewpoint adjustment reference sample 1 is compared with the data at the time of shipment, and each line camera is adjusted according to the comparison results so that the viewpoint positions of the line cameras 7 are uniform.

[0066] (3. Adjustment during installation) In addition, when the actual machine is installed, the line camera viewpoint adjustment reference sample 1 is placed at the work position so that the line camera viewpoint adjustment reference 1 is tilted relative to the movement direction of the inspected object 5, and inspection is performed. The test data obtained by capturing the transmitted light of the line camera viewpoint adjustment reference 1 is compared with the installation data, and the line camera 7 is adjusted and installed according to the comparison result.

[0067] (4. Adjustment during maintenance) Furthermore, during maintenance of the actual machine, a line camera viewpoint adjustment reference sample 1 is placed at the work position and inspection is performed so that the line camera viewpoint adjustment reference 1 is tilted relative to the movement direction of the inspected object 5, and the test data obtained by capturing the transmitted light through the line camera viewpoint adjustment reference 1 is compared with the maintenance data, and a maintenance adjustment is performed in which each line camera is adjusted according to the comparison result so that the viewpoint positions of the line cameras 7 are uniform.

[0068] In the sample inspection process, an existing defect inspection device is used to set the line camera viewpoint adjustment reference sample 1 at an angle to the work position, and a new inspection of the line camera viewpoint adjustment reference sample 1 is performed. Image data from the line camera 7 is output to the inspection unit, where image processing is performed to generate output data. This test data is stored in a storage unit such as a memory, HDD, or SSD.

[0069] Next, the test data is repeatedly acquired, and the line camera viewpoint adjustment reference sample 1 is similarly set at an angle to the work position, and the inspection is performed multiple times.

[0070] Each time an inspection is performed and test data is generated, the adjustment unit compares the test data with the shipping data to verify that there is no difference between the shipping data and the test data.

[0071] That is, the output value (maximum peak value) of the large defect in the test data as shown in Figure 7 is compared with the output value (maximum peak value) of the large defect in the shipping data, and the output value (maximum peak value) of the medium defect in the test data as shown in Figure 8 is compared with the output value (maximum peak value) of the medium defect in the shipping data, and it is checked whether the difference is within the threshold value (3%). When the output values ​​of all the test data are within the threshold value, the adjustment unit determines that there is no difference between the test data and the shipping data. This confirms the reproducibility of the test data.

[0072] Here, in order to improve the accuracy of the inspection during adjustment, it is necessary to set the line camera viewpoint adjustment reference sample 1 at a specified work position. Therefore, as shown in Figures 9 and 10, an installation jig 11 is used to set the line camera viewpoint adjustment reference sample 1 at an angle to the actual work position. The installation jig 11 holds the outer periphery of the line camera viewpoint adjustment reference sample 1, and is detachably attached to the case 9 of the light source 2 by the support 12 of the installation jig 11.

[0073] At the time of shipment, the line camera viewpoint adjustment reference sample 1 is tilted and installed at the work position using an installation jig 11 in the manufactured actual machine, and inspection is performed. The adjustment unit compares the test data with the shipment data to check whether the difference between the output value of the test data and the output value of the shipment data is within a threshold value. This check is performed in the same manner as the confirmation method used during repeated inspection in the sample inspection process. If the difference in output values ​​is within the threshold value, it is deemed to be passed, and no adjustment is made. If the difference in output values ​​is equal to or greater than the threshold value, it is deemed to be failed, and the position of the line camera 7 is adjusted.

[0074] The adjustment unit analyzes the rejected shipping data, identifies the shipping data corresponding to the rejected output value and the difference therebetween, and determines the degree of adjustment. A table storing data on the position direction and movement amount of the line camera 7 according to the identified defects and differences is saved in the memory unit, and the degree of adjustment can be determined by referring to the table. The adjustment unit outputs a command signal based on the determined degree of adjustment to the movement unit. The movement unit operates to adjust the position of the line camera 7. After the adjustment, an inspection is performed again to determine whether it passes or fails. If it passes, the installation jig 11 is removed, and the manufactured actual machine is shipped.

[0075] When the actual machine is delivered and installed on-site, adjustments at the time of installation are made using the line camera viewpoint adjustment reference sample 1. The adjustments at the time of installation are made in the same way as the adjustments at the time of shipment.

[0076] Furthermore, when maintenance is performed during use of the actual machine, the line camera viewpoint adjustment reference sample 1 is used to perform adjustments during maintenance in the same manner as the adjustments at the time of shipment.

[0077] However, the threshold value (1%) in the adjustment process during maintenance is set higher than the threshold value (3%) in the inspection process before shipping.

[0078] As described above, by performing adjustments using the line camera viewpoint adjustment reference sample 1, it is possible to easily check the adjustments at the time of shipment, installation, and furthermore, during maintenance, and it is possible to eliminate variations among multiple line cameras and perform uniform viewpoint adjustments based on the same standard.

[0079] Therefore, the inspection accuracy of the defect inspection device can be maintained, and reliability can be improved.

[0080] In addition, by tilting the line camera viewpoint adjustment reference sample 1, the peak of the output waveform for the defect becomes clear, allowing the defect to be detected reliably and the effect of positional misalignment of the line camera 7 to be accurately recognized.

[0081] Moreover, by changing the installation angle of the line camera viewpoint adjustment reference sample 1 or shifting the installation position, the data from the line camera 7 can be set according to the inspection device.

[0082] It should be noted that the present invention is not limited to the above-described embodiment, and it is of course possible to make many modifications and changes to the above-described embodiment within the scope of the present invention. [Explanation of symbols]

[0083] 1 Line camera viewpoint adjustment reference sample 2 grooves 3 grooves 4 grooves 5. Test subject 6 light source 7 Line Camera 8 Slit 9 Cases 10 Pedestal 11 Installation jig 12 Support

Claims

1. A reference sample for adjusting the viewpoint of a line camera, comprising a rectangular flat plate made of colorless, transparent acrylic resin, having a plurality of grooves arranged in parallel from one end of the long side of the plate to the other end, the cross sections of the plurality of grooves being arc-shaped, the cross sections being a plane parallel to a plane perpendicular to the extension direction of the grooves, the widths of the arcs of the plurality of grooves being different, and the depths of the plurality of grooves being the same.

2. An inspection device comprising: a linear light source that irradiates a light-transmitting inspection object with light; a plurality of line cameras that are arranged in a line facing the light source across the inspection object and capture images of light that has passed through the moving inspection object; and a slit that cuts off the spread of light from the light source, 2. A uniform viewpoint adjustment device for line cameras, which uses the line camera viewpoint adjustment reference sample according to claim 1 to determine adjustment degrees of the viewpoints of a plurality of line cameras.

3. A uniform viewpoint adjustment device for a line camera as described in claim 2, characterized in that the viewpoint adjustment reference sample for the line camera as described in claim 1 is installed at the work position at an angle relative to the movement direction of the inspected object.

4. A uniform viewpoint adjustment device for a line camera as described in claim 2, characterized in that it is provided with an installation jig for installing a viewpoint adjustment reference sample for the line camera as described in claim 1 at a work position at an angle relative to the movement direction of the inspected object.

5. An inspection device comprising: a linear light source that irradiates a light-transmitting inspection object with light; a plurality of line cameras that are arranged in a line facing the light source across the inspection object and capture images of light that has passed through the moving inspection object; and a slit that cuts off the spread of light from the light source, 2. A method for uniformly adjusting viewpoints of line cameras, comprising: adjusting adjustment degrees of viewpoints of a plurality of line cameras using the line camera viewpoint adjustment reference sample according to claim 1.

6. An inspection device comprising: a linear light source that irradiates a light-transmitting inspection object with light; a plurality of line cameras that are arranged in a line facing the light source across the inspection object and capture images of light that has passed through the moving inspection object; and a slit that cuts off the spread of light from the light source, 2. A method for uniformly adjusting viewpoints of line cameras, comprising: measuring a waveform of the amount of received light of each of a plurality of line cameras using the line camera viewpoint adjustment reference sample according to claim 1; and adjusting the degree of adjustment of the viewpoints of the line cameras.

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