WO2001038013A1

WO2001038013A1 - Work inspection device

Info

Publication number: WO2001038013A1
Application number: PCT/JP2000/008213
Authority: WO
Inventors: Kazuhiro Kikawa; Kenji Kobayashi
Original assignee: Lintec Corporation
Priority date: 1999-11-22
Filing date: 2000-11-21
Publication date: 2001-05-31
Also published as: KR20010083922A; CN1322155A; MXPA01004151A; IL144414A0; JP2001327929A

Abstract

A work inspection device wherein a conveyor belt (201) is formed with a V-groove (201a) and work (1) is placed in the V-groove (201a) and conveyed, during which conveyance the size of the work (1) and its two adjacent surfaces (1c, 1d) are inspected by a first camera (203). Further, a reversing belt (205) abuts against the conveyor belt (201), the reversing belt (205) being likewise formed with a V-groove (205a), so that the work (1) is continuously reversedly transferred from the conveyor belt (201) to the reversing belt (205) while being held between the conveyor belt (201) and the reversing belt (205), and the reversed work (1) has its two other adjacent surfaces (1e, 1f) inspected by a second camera (207). After inspection, the capacity of capacitors is measured by a measuring probe (233) and upon completion they are counted off into groups of a fixed number which are then packed each in a bulk case (303).

Description

Specification

Work inspection equipment Technical field

The present invention relates to a work inspection device for inspecting an end face of a work. Conventional technology

As a conventional work inspection apparatus, an apparatus described in Japanese Patent Application No. Hei 9-1315506 is known. This device is for inspecting the end face of a hexahedral work. A first disc having a number of first concave portions formed on an outer periphery for gripping the work is arranged orthogonally to the first disc. A second disk having a plurality of second recesses formed on the outer periphery for receiving and gripping the work in the first recess. Further, a first end face inspection force lens for inspecting three surfaces of the work is provided outside the first disk, and a second inspection force for inspecting the remaining three surfaces of the work is provided outside the second disk. An end face inspection camera is provided.

In the work inspection apparatus described in the above publication, the work is gripped by the concave portion formed in the disk for the inspection, so that when the work is inserted into the disk and discharged from the disk, the rotation of the disk is performed each time. This has to be stopped, which limits the ability to inspect the workpiece while transporting it at high speed.

The present invention has been made in view of the above points, and an object of the present invention is to further improve the inspection speed of a workpiece in a workpiece inspection device.

Disclosure of the invention

In order to solve the above-mentioned problems, according to the present invention, a groove inspection device is formed such that a groove is formed in a conveyor belt, a work is placed in the groove, and the work is conveyed. Was configured.

Further, in the present invention, the work is placed and transported in a gap formed between at least two transport belts, and the gap is gradually narrowed toward the downstream side in the transport direction, so that the The posture was provided so that it could be corrected.

The reverse belt is provided with a groove facing the groove, and the workpiece is transferred from the transport belt to the reverse belt. The work was turned over by transferring it to the work.

By providing the vibration means for vibrating the transport belt, the posture of the work placed on the transport belt can be corrected.

The groove may be formed in a V shape.

Further, a first camera for imaging the exposed surface of the work placed on the transport belt and a second camera for imaging the exposed surface of the work inverted by the reversing belt are provided.

Here, on the downstream side of the first and second cameras, defective product discharge units capable of discharging the work determined to be defective in the inspection of each of the cameras are provided, respectively. The work is configured so that the work can be discharged by blowing compressed air.

In addition, a non-defective product extracting unit that sends a non-defective product that has passed the inspection of the first and second cameras to a work filling unit is provided, and the non-defective product extracting unit is provided so as to be able to discharge the work by blowing compressed air. A configuration was also adopted.

Further, according to the present invention, there is provided a workpiece inspection apparatus for forming a groove in a transport belt, placing a workpiece in the groove, transporting the workpiece, and imaging and inspecting an exposed surface of the workpiece. A vibrating means for causing the workpiece to have a rectangular cross-section; a width of the groove being shorter than a length of a diagonal line of the rectangle; and a depth of the groove when the workpiece is placed in the groove. The work was configured such that the corners of the work did not touch the bottom of the groove. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a side view of the work inspection apparatus according to the first embodiment of the present invention, FIG. 2 is a plan view of the work inspection apparatus, FIG. 3 is a perspective view of the work, and FIG. FIG. 5 is a perspective view, FIG. 5 is a cross-sectional view of a process of inspecting the work with a camera, FIG. 6 is a cross-sectional view taken along the line II-II of FIG. FIG. 8 is a cross-sectional view showing a second embodiment of the conveyor belt and a reversing belt, FIG. 9 is a cross-sectional view showing still another example of the conveyor belt, and FIG. Side view of the workpiece inspection device according to the third embodiment, FIG. FIG. 12 is a perspective view showing the transport belt according to the embodiment together with the workpiece, FIG. 12 is a plan view showing the transport belt according to the third embodiment together with the workpiece, and FIG. 13 (A) is a view at a position S on the upstream side in FIG. FIG. 13 (B) is a cross-sectional view at the downstream P position and the first camera position in FIG. 12, and FIG. 14 illustrates a defective product discharging unit and a non-defective product extracting unit according to the third embodiment. FIG. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described with reference to the drawings.

1 and 2 show a work inspection apparatus 10 according to a first embodiment of the present invention. This apparatus uses a work 1 (ceramic chip capacitor) having dimensions and four end faces (1 ld, le, Check 1 f). The work 1 is, for example, a hexahedron of about l mm x 0.5 mm x 0.5 thigh, and two opposing surfaces 1 a and 1 b are electrodes. The work inspection device 10 of the present invention inspects the dimensions of the work 1 and the presence or absence of scratches, discoloration, and dents on the mold 1 (dielectric portion) using the cameras 203 and 207.

As shown in FIG. 1, the work inspection apparatus 100 includes a work supply unit 100 for aligning and supplying the work 1 and a work inspection unit for inspecting the dimensions of the work 1 and inspecting the quality of the remaining four surfaces other than the electrodes. It is composed of 200 and a work filling unit 300 that counts the number of works 1 that have been inspected and packs the counted works 1 into a case.

A parts feeder 101 is arranged in the work supply unit 100. A large number of workpieces 1 put into the ball portion of the powder feeder 101 are supplied one by one to the transport path 103 while being aligned and transported by the transport grooves on the spiral. As the part feeder 101, for example, the one described in Japanese Patent Application Laid-Open No. 5-285649 can be used. The workpiece 1 is pushed out to the transport path 103 by the parts feeder 101 so that the electrodes 1 a and 1 b are located at the front and rear positions in the transport direction, and is sent to the work inspection unit 200.

The workpiece inspection unit 200 includes an endless transport belt 201 that transports the workpiece 1, a first camera 203 that images the workpiece 1 transported on the transport belt 201, and a transport belt 210. And a second camera 207 for picking up an image of the workpiece 1 on the reversing belt 205. Conveyor belt 201 is a drive pulley — 209, the driven pulley 2 1 1, and the tension pulley 1 2 1 3, and the driving pulley 209 is rotated by the motor 215.

As shown in FIG. 4, the V-grooves 201a are formed on the transport surface of the transport belt 201 along the transport direction of the transport belt 201 (from left to right in FIG. 4). Endlessly formed in the center of 1. As shown in FIG. 4, the work 1 is placed one after another in the V-groove 201 a from the transport path 103 with the electrodes l a and lb forward and backward. At this time, the end surfaces 1 e and 1 f of the work 1 are placed in contact with the groove surface of the V-groove 201 a, and the other opposing end surface 1 c Id is exposed. An image is taken by the exposed end face l c, 1 d force first camera 203. Based on the output signal from the first camera 203, the external dimensions of the work 1 and the cracks, scratches, discoloration, flying of the silver paste, etc. of the end faces l c and I d are image-processed and inspected.

On the upstream side of the first camera 203, a photo sensor 217 for detecting the passage of the work 1 is arranged. Based on a detection signal of the photo sensor 217, the shooting timing of the first camera 203 is determined. It is determined and the dimensions of the work 1 and the image processing of the inspection surfaces 1c and 1d are performed. Further, a suction nozzle 2 19 is disposed downstream of the first camera 203, and the work 1 determined to be defective in the inspection of the first force camera 203 is sucked and discharged by the suction nozzle 2 19. .

A reversing belt 205 (FIG. 1) is hung on the pulley 209. The reversing belt 205 has a V-groove 201a similar to the V-groove formed on the conveyor belt 201, and as shown in FIG. 0 Partially in contact with 1. That is, as shown in FIG. 1, the transport belt 201 and the reversing belt 205 come into contact with each other over substantially half of the circumference of the pulley 209, and the reversing belt 205 has a plurality of pulleys 220. The belt is hung on 1, 2 2 2, and the pulley 2 2 2 is driven to rotate in synchronization with the conveyor belt 201 by a drive motor (not shown). The work 1 is rotated by approximately 180 degrees by the pulley 209 while being sandwiched between the V-groove 201 a of the conveyor belt 201 and the V-groove 201 a of the reversing belt 205. It is delivered from the conveyor belt 201 to the reversing belt 205. In the reversing belt 205, the end faces 1e and 1f of the work 1 reversely transferred in the V-groove 201a of the conveyor belt 205 are exposed. A scraper 225 is disposed near the lower peripheral edge of the pulley 209. The work 1 is restricted so that the work 1 does not return to the transport belt 201 again, whereby the work 1 is surely transferred to the reversing belt 205.

On the downstream side of the scraper 225, a second camera 207 is arranged. By the second camera 207, the dimensions of the work 1 and the cracks, scratches, discoloration and silver paste of the end faces 1e and If are formed. Inspection and image processing are performed for skipping. In addition, as in the case of the first camera 203, the second camera 200 detects the work 1 with a photo sensor (not shown) installed on the upstream side of the second camera 200, processes the image, and processes the image. Defective products are sucked and discharged by the suction nozzle 227 provided downstream of 207.

At the downstream end of the reversing belt 205, a chute 229 is arranged, whereby the peak 1 is transferred from the reversing belt 205 to the pickup roller 231. A large number of recesses 2 31 a are formed on the circumferential surface of the pickup roller 2 31, and the work 1 flowing along the chute 229 is accommodated one by one in the recess 2 31 a. Pickup roller 1 2 3 1 rotates counterclockwise. Workpiece 1 at the top is measured by measuring probe 2 3 3 Capacitor capacitance of work 1 is measured one by one, and defective product is suction nozzle 2 3 Sucked and discharged by 5. The work 1 that has passed the inspection is sent to the next work filling section 300.

The work filling section 300 transports a hopper 301 that accumulates and drops the work 1 by a fixed quantity, a bulk case 300 that stores the work that falls from the hopper 301, and a bulk case 303 that conveys the work. And a labeler 323 for attaching a bar code label 325 to the bulk case 303. Pickup rollers — counting hoppers 307 and 309 are arranged between 231 and hopper 301, and counting hoppers 307 and 309 are connected by connecting plate 311 and cylinder 3 It can be switched by 13. Each counting hopper 307, 309 has a shutter (not shown) on the lower surface of each hopper.

First, the work 1 is counted by a counting counter sensor 302, and a predetermined number of works 1 are accumulated in a counting hopper 307. When a predetermined number is reached, a shutter (not shown) is opened and the work 1 is moved to the hopper 3 0 Dropped to 1. This is the quantity of work 1 for one case of the bank case 303. At this time, the rotation of the pick-up port 2 3 1 stops temporarily, the cylinder 3 13 is driven, and the counting hopper 3 09 The pickup roller 231 moves immediately below the pickup roller 231, and then the pickup roller 231 rotates again, and a predetermined number of works 1 are counted by the sensor 302 and accumulated in the counting hopper 309.

The bulk case 303 is conveyed by the conveyor belt 305 and the sensor 315 confirms that the bulk case shutter 303 a (bulk case lid) is closed before the filling nozzle 3 of the hopper 301 Conveyed to 0 1 a. Immediately below the filling nozzle 301a, the positioning arm 317 positions the bulk case 303. After that, the bulk case shutter opening / closing device 3 19 opens the bulk case shutter 3 0 3 a to stand by, and opens a shutter (not shown) at the end of the filling nozzle 3 0 1 a to open a predetermined amount of one bulk case 3 0 3. The work 1 is caused to flow down from the hopper 301 to fill the bulk case 303, and then the bulk case shutter 303 a is closed by the operation of the bulk case shutter opening / closing device 319. After completion, the positioning arm 3 17 is released, and the bulk case 303 is transported downstream (from left to right in Fig. 1) by the transport belt 300, and on the way, the bulk case shirt is detected by the sensor 3 21 Evening 30 3 Make sure that a is closed. Next, a bar code label 325 is attached to the side of the bulk case 303 by the labeler 323, and the bulk case 303 is transported further downstream, packed in a predetermined manner, and shipped.

As described above, according to the above device, the work 1 and the end faces 1c, Ic are kept while the work 1 is placed in the V-groove 201a formed in the transport belt 201 and the reversing belt 205. Since four cameras d, le, and 1f can be inspected by two cameras, the work 1 can be inspected efficiently. In addition, the V-grooves 201 formed in the transport belt 201 and the reversing belt 205 can continuously reverse the workpiece 1 while holding the workpiece 1 therebetween. It can be easily inverted, and high-speed image processing of the work dimensions and the end faces 1c to lf is possible.

Furthermore, in order to accommodate workpieces 1 of different sizes, the V-grooves 201a are provided with a plurality of rows of V-grooves 201a corresponding to different sizes on the same conveying belt 201 and reversing belt 205. It may be formed endlessly, and the transport path 103 may be switched to a V-groove that matches the work size. In the present embodiment, the V-grooves 201 a are formed along the belt conveyance direction. However, the present invention is not limited to this. May be formed in a direction orthogonal to. The shape of the groove is not limited to the V-shaped groove, but may be another shape such as a semicircular cross section.

In the above-described embodiment, the bulk case filling packaging described as the packaging form is not limited thereto, and the carrier 1 may be a carrier tape package for supplying the workpiece 1 by attaching the workpiece 1 to a paper or plastic carrier tape at predetermined intervals.

7 and 8 are cross-sectional views showing a second embodiment of the conveyor belt. A groove 202 a having a rectangular cross section is formed in the conveyor belt 202, and a work 1 having a square cross section (a square in the embodiment) is placed in the groove 202 a. The width W of the groove 202a is shorter than the length d of the diagonal line of the cross section of the work 1, and the depth of the groove 202a is the corner 1 when the work 1 is fitted into the groove 202a. g has such a size that it does not touch the bottom 202 b of the groove 202 a. Therefore, when the work 1 is placed in the groove 202a, as shown in FIG. 7, the side surfaces 1e and 1f of the workpiece 1 are edged to the groove 202c and 202, respectively. Point contact with d.

The conveyor belt 202 is supported by a belt receiver 204 and moves on the belt receiver 204. The belt receiver 204 is connected to a vibrator (vibration device) 206 composed of a motor and the like. Since the conveyor belt 202 is vibrated by the vibrator 206, the posture of the work 1 is changed by the vibration of the belt 202 even when the work 1 is placed at an angle as shown by the chain line in FIG. As shown by the solid line in FIG. 7, it is corrected so as to be substantially symmetrical, and the end faces lc and 1d of the work 1 can be uniformly photographed by the camera 203.

Although the vibrator 206 exhibits the effect of correcting the posture of the work 1 even when attached to the apparatus shown in FIG. 1, it is more preferable to use the vibrator 206 in combination with the configuration shown in FIG. can get. That is, the groove 202 a shown in FIG. 7 is in point contact with the end faces 1 e and 1 f of the work 1 by its two edges 200 c and 202 d, and the corner 1 g is a groove. since not in contact with the 2 0 2 a bottom 2 0 2 b of the vibrating the conveyor belt 2 0 2 by bi Bureta ₂ 0 _6, so that the attitude of the workpiece 1 by the vibration is facilitated symmetrical correction Is done.

After the work 1 is photographed by the camera 203, as shown in FIG. 8, the work 1 is inverted while being sandwiched between the transport belt 202 and the reversing belt 205A described above. It is. This inversion method is the same as described above.

FIG. 9 shows another example of the conveyor belts 208 and 210. As the grooves of the conveyor belt, a semi-circular groove 208a as shown in FIG. 9A and FIG. 9B A groove 210a having a V-shaped cross section as shown in FIG. In short, when the work 1 is inserted into the groove, it is sufficient that the corner 1 g of the work 1 does not contact the bottom of the groove.

Next, a third embodiment of the present invention will be described with reference to FIGS. In the following description, the same reference numerals are used for the same or equivalent components as those in the first and second embodiments, and the description is omitted or simplified. The third embodiment is characterized in that the work 1 is conveyed while nipping the work 1 between conveyance belts 240 and 241, which are provided in at least two rows in the conveyance direction. Is characterized in that the extraction of compressed air is performed by blowing compressed air.

FIG. 10 shows a schematic diagram of a work inspection apparatus 20 according to the third embodiment. In this figure, the work inspection device 20 is different from the structure of the work inspection device 10 (FIG. 1) according to the first embodiment in that the work 1 is sandwiched between two rows of conveyor belts 240 and 241. In addition to the difference in that the structure is such that the workpiece 1 is conveyed while being inserted, the work 1 determined to be defective by the first and second cameras 203,207 is discharged by blowing compressed air. It is different in that it has defective product discharge sections 249 and 250 and a non-defective product extraction section 255 that transfers non-defective products that have passed the inspection to the work filling section 300 by blowing compressed air. . The other configuration is substantially the same as the configuration of the first embodiment.

As shown in FIGS. 11 and 12, the conveyor belts 240 and 241 move from the upstream side (left side in FIG. 12) in the conveying direction to the downstream side (right side in FIG. 12). The gaps, that is, the gaps (W), are gradually narrowed. In other words, the mutual separation width (W) formed between the transport belts 241 and 242 is determined by the S position on the upstream side in the transport direction (the workpiece transfer at the tip of the parts feeder-work alignment member 104). The width gradually decreases from the mounting portion 105) to the downstream P position (near the upstream of the first camera 203). Here, as shown in FIG. 13, the separation width W 1 at the most upstream (S) position in the transport direction is such that the corner 1 g of the work 1 does not come into contact with the bottom 2 45 a, It is sufficient that each end face I d, le of 1 has a separation width W 1 that can be hooked between the inner upper corners 240 a, 2 41 a of each belt 240, 241. In other words, at the most upstream (S) position in the transport direction, the separation width W1 is slightly smaller than the diagonal length d of the rectangular cross section of the work 1, while the most downstream (P) position in the transport direction (FIG. 13) In (B)), the separation width W2 is smaller than the separation width W1 at the upstream (S) position. Therefore, at the most upstream (S) position in the transport direction (work transfer section 105), the work 1 from the work supply section 100 is supplied and transferred to the transfer belts 240 and 241. At the same time as the distance between the regions L gradually decreases along the transport direction, the transport belt 240 and the transport belt 240 are provided by the vibrator 206 (vibration device) provided in the same manner as in the second embodiment. By vibrating 2 41, it is possible to gradually correct the posture of the work 1 left and right as it is conveyed. The vibrator 206 is synchronized with the rotation of the conveyor belts 240 and 241 so that the posture of the work 1 can be corrected more reliably.

The first and second defective product discharging units 249 and 250 are provided at two locations downstream of the first and second cameras 203 and 207, respectively. 255 are provided at two locations downstream of the second defective product discharge unit 250. Here, the first and second defective product discharge sections 249 and 250 and the non-defective product extraction section 255 are provided in two places, respectively. This is an auxiliary device to ensure that the work 1 can be taken out downstream if the work 1 cannot be taken out. In addition, the first and second defective product discharge sections 249, 250 and the non-defective product extraction section 255 are provided with the work belt 1 conveyed by the conveyance belts 240, 241 or the reversing belt 205. There is a pipeline 259 (Fig. 14) that crosses at right angles to the direction of travel above. The pipe line 259 in the first defective product discharge section 249 has an opening 261 large enough to allow the workpiece 1 to pass therethrough at a position above the conveyor belts 240, 241. Similarly, similar openings 261 are also formed in the ducts 259 in the second defective product discharging section 250 and the non-defective product extracting section 255, respectively. Further, the compressed air A is fed into the pipe line 259 from a compressed air generator (not shown) (not shown). The compressed air A is controlled by a control circuit (not shown), and the compressed air A supplied from the pipe 259 A is further compressed by the small-diameter pipe 259 B. A negative pressure is generated in the opening 261, by injecting the compressed gas into the large-diameter conduit 255C, and the workpiece 1 is sucked by the suction force generated in the opening 261 by the negative pressure. From the part 261, it is guided into the large-diameter conduit 2559C, and is discharged or extracted out of each of the conveyor belts 240, 241, or the reversing belt 205. In other words, in the first defective product discharging section 249, if a certain work 1 is determined to be defective by the inspection of the first camera 203, the small-diameter pipeline is shifted at a timing corresponding to the transfer speed of the work 1. Compressed air A is injected into the large-diameter pipeline 2559C from 2559B, thereby generating a negative pressure (suction force) at the opening 261, and the defect located at the opening 261 The work 1 determined to be is guided into the large-diameter pipeline 259C. On the other hand, the work 1 that is not determined to be defective by the inspection of the first camera 203 is conveyed as it is toward the downstream second camera 207 without blowing the compressed air A. In the second defective product discharge section 250, the same inspection as the first force camera 203 is performed on the back surface of the work 1 that has been turned approximately 180 degrees by the halfway reversing belt 205 in the same manner as the second camera 2. 07, and as a result, only the work 1 determined to be defective is placed in the large-diameter pipe 2559C by the same operation as the above-mentioned first defective discharge section 2449. I'm leading. Then, in the non-defective product extracting section 255, the compressed air A is fed into the pipe line 255 almost all the time, and the compressed air A is not discharged in the second defective product discharging section 250. The entire work 1 is extracted and supplied to a hopper 310 (FIG. 10). Hereinafter, in FIG. 10, components having the same reference numerals as those in FIG. 1 repeat the same operations as in FIG. 1, load a predetermined number of works 1, fill the bulk case 303, Furthermore, a specified label is attached and discharged outside the machine.

In the third embodiment, the reversing belt 205 may also be constituted by two rows of belts capable of sandwiching the work 1, and may have the grooves described in the first and second embodiments. Of course, it may be constituted by a belt.

In the first to third embodiments, the work 1 is a ceramic chip capacitor, but may be a hexahedron such as a chip resistor.

As described above, according to the present invention, a groove is formed in a belt, a work is placed in the groove, and the two end faces of the work are inspected simultaneously. The conventional intermittent inversion method It is possible to speed up the inspection compared to the formula.

In addition, the work is placed and transported in the gap between the two belts, gradually narrowed toward the downstream side in the transport direction, and further transported while vibrating the belt. Can be corrected. Industrial applicability

INDUSTRIAL APPLICABILITY The present invention can be used, for example, as an apparatus that determines the quality by imaging an exposed surface of a work such as a ceramic chip capacitor.

Claims

The scope of the claims

1. A work inspection apparatus, wherein a groove is formed in a conveyance belt, a work is placed in the groove and conveyed, and an exposed surface of the work is imaged and inspected.

2. The work is placed and conveyed in the gap formed between at least two conveyor belts, and the gap is gradually narrowed toward the downstream side in the conveyance direction so that the posture of the work can be corrected. A work inspection device characterized by being provided.

3. A reversing belt is provided to partially contact the transport belt, and the reversing belt is provided with a groove corresponding to the groove or gap, and the workpiece is transferred from the transport belt to the reversing belt.ヮ according to claim 1 or 2, wherein

4. The work inspection apparatus according to claim 1, further comprising a vibration unit configured to vibrate the transport belt.

5. The work inspection apparatus according to claim 1, wherein the groove has a V shape.

6. A claim according to claim 3, comprising: a first camera for imaging an exposed surface of the work placed on the transport belt, and a second camera for imaging the exposed surface of the work inverted by the reversing belt. Work inspection device as described.

7. At the downstream side of the first and second cameras, there is provided a defective product discharge unit capable of discharging a work determined to be defective in the inspection of each of the cameras, and the defective product discharge unit The workpiece inspection device according to claim 6, wherein the workpiece inspection device is provided so as to be able to be discharged by blowing compressed air.

8. Send a good work that passed the inspection of the first and second cameras to the work filling section. The work according to claim 6, further comprising a non-defective product extraction unit, wherein the non-defective product extraction unit is provided so that the work can be discharged by blowing compressed air.

9.A workpiece inspection apparatus for forming a groove in a transport belt, placing a workpiece in the groove, transporting the workpiece, and imaging and inspecting an exposed surface of the workpiece, wherein a vibrating means for vibrating the transport belt is provided. The work has a rectangular cross-section, the width of the groove is shorter than the length of a diagonal line of the square, and the depth of the groove is a corner of the work when the work is placed in the groove. A workpiece inspection device having a dimension that does not touch the bottom of the groove.