TWI896611B - Inspection device - Google Patents

Abstract

The present invention provides an inspection device specifically for detecting defects and peelings on the electrode portion of an electronic component. The device comprises a conveyor mechanism for conveying an object to be inspected, a first lighting mechanism disposed on one side of the object to be inspected, a second lighting mechanism disposed on the opposite side, and a camera disposed on the side of the object to be inspected to photograph the inspected surface. The first lighting mechanism positions a first light emitter located near the conveyor path at a position farther from the inspection position than another set of first light emitters. The second lighting mechanism is disposed at a position symmetrical to the first lighting mechanism across a conveyor sheet and comprises a second light emitter located near the conveyor path and another set of second light emitters. The 1/2 beam angle of the first light emitter of the first lighting mechanism and the second light emitter of the second lighting mechanism is within the range of 30° to 80°, and the 1/2 beam angle of the first light emitter of the first lighting mechanism and the second light emitter of the second lighting mechanism is within the range of 10° to 25°.

Description

Inspection device

The present invention relates to an inspection device capable of inspecting the external appearance of tiny objects such as electronic components with high precision.

As one device for inspecting the appearance of electronic components, the inspection device disclosed in Patent Document 1 (Japanese Patent Application Publication No. 5-288527) is known in the prior art. This inspection device comprises: a mechanism for moving a printed circuit board placed on a stage in the X and Y directions; an illumination mechanism comprising a plurality of LEDs arranged in a dome shape to illuminate the inspected portion of the printed circuit board; and a video camera for capturing the inspected portion of the printed circuit board through an aperture formed in the top of the illumination mechanism.

According to this inspection device, the inspection portion on the printed circuit board is illuminated by the illumination mechanism, and an image of the inspection portion is captured by the video camera. The captured image data is then analyzed to determine whether the appearance of the inspection portion is satisfactory.

Conventional inspection devices, while maintaining the same basic structure, include mechanisms for moving the object under inspection, illuminating the object, and capturing images of the object. However, these devices are designed and modified to suit the shape of the object under inspection and the area to be inspected.

For example, when inspecting the end faces of hexahedral electronic components (e.g., capacitors), the following configuration is employed: The electronic component is suitably transported in a predetermined direction by a transport mechanism. At an inspection position located at a predetermined position along the transport path, the front face of the electronic component is illuminated from the front in the transport direction by an illumination mechanism. Furthermore, the front face of the electronic component is suitably photographed from an oblique front angle using a camera.

In this case, the lighting mechanism adopts the aforementioned lighting mechanism in which the LEDs are arranged in a dome shape by dividing the LEDs along a vertical plane perpendicular to the conveying direction of the conveying mechanism, so that the front end surface of the electronic component is illuminated from the portion on the front side in the conveying direction.

In addition, a through-hole is provided in the position of the lighting mechanism where no LED is arranged, and the camera is used to photograph the front surface of the electronic component through this through-hole.

Furthermore, when inspecting the appearance of the front surface of an electronic component, for high-precision inspection, it is best to position the camera so that the angle (elevation angle) between the transport direction and the camera's optical axis is as small as possible, allowing the front surface of the component to be photographed from the front whenever possible. Photographing the front surface from the front maximizes image data and enables more accurate analysis.

Furthermore, the LEDs of the illumination mechanism are preferably positioned so that their illumination optical axes are as close to a right angle as possible with respect to the front face of the electronic component, in other words, as close as possible to the transport path of the transport mechanism. By placing the LEDs close to the transport path, a camera positioned so that the elevation angle of its imaging optical axis is as small as possible can capture more reflected light from the front face, resulting in clearer images captured by the camera. This sharp image improves the accuracy of analysis performed based on the image.

In recent years, the miniaturization of electronic components has accelerated. Previously, electronic components had a cross-section of 3mm x 2mm, but now they have been reduced to 0.4mm x 0.2mm. To accommodate this miniaturization, the aforementioned camera and LED configuration is also preferred.

However, when adopting a structure that minimizes the elevation angle of the camera's optical axis and places the LEDs as close as possible to the transport path of the transport mechanism, the camera's optical axis and the LEDs interfere with each other, making it impossible to provide a through-hole in the lighting mechanism for capturing electronic components, effectively preventing the electronic components from being captured.

Therefore, in view of this problem, the inventors of this case have proposed the inspection device disclosed in the following Patent Document 2.

This inspection device transports an object to be inspected, such as an electronic component, in a predetermined transport direction and inspects at least the front or rear end of the object in the transport direction. The inspection device comprises at least: a transport mechanism having a transport path along the transport direction for transporting the object on the transport path in the transport direction; an illumination mechanism disposed on the same side of the transport path as the object to be inspected, and illuminating the inspected surface of the object being transported by the transport mechanism at a predetermined inspection position on the transport path; and a camera disposed on the same side as the object to be inspected, for capturing an image of the inspected surface of the object at the inspection position.

The illumination mechanism includes a plurality of light emitters for illuminating the inspected surface of the inspected object and a support body for supporting the plurality of light emitters. The support body supports the light emitters closer to the transport path at a position farther from the inspection position than the other light emitters, and defines a space between the farther light emitters and the other light emitters, allowing the inspected surface of the inspected object to be observed from the back side opposite to the inspection position. The camera is disposed on the back side of the support body and images the inspected surface of the inspected object through the space in the support body.

According to this inspection device, the object to be inspected is transported along its transport path by a transport mechanism. At the inspection position on the transport path, the inspection surface is photographed by the camera while the illumination mechanism illuminates the inspection surface.

Furthermore, the illumination mechanism positions at least the light emitters proximate to the transport path at a position farther from the inspection position than the other light emitters. Therefore, while the light emitters proximate to the transport path are positioned as close as possible to the transport path of the transport mechanism, an appropriate distance can be set between the light emitters and the other light emitters, allowing space to be provided in this area for capturing images of the inspected surface of the object being inspected.

Furthermore, by adopting this structure, the camera can be positioned so that the angle (elevation angle) between its imaging optical axis and the transport path is as small as possible, that is, as close to the transport path as possible. This positioning allows the camera to capture the inspected surface of the object as closely as possible from the front. This allows the image of the inspected surface captured by the camera to be captured in a larger image, resulting in highly accurate inspection of the surface's appearance.

Furthermore, as described above, since the light emitter is positioned as close to the transport path as possible, the camera can capture more reflected light from the inspected surface, resulting in clearer images. This allows for a clearer image of the inspected surface, enabling highly accurate inspection of its appearance.

Existing technical literature Patent Literature

Patent Document 1: Japanese Patent Application Publication No. 5-288527

Patent Document 2: Japanese Patent Publication No. 2014-160016

However, while the inspection disclosed in Patent Document 2 achieves the aforementioned favorable effects, further improvements are required in the following aspects.

In the field of electronic components such as capacitors, electrical characteristics are inspected by placing a probe in contact with the end face of an electrode. This contact sometimes creates a probe mark on the end face. Since the probe makes contact, the contact mark appears flatter than the rest of the surface. Therefore, this does not constitute a cosmetic defect, nor does it constitute a quality defect.

On the other hand, scratches, chips, and peeling on the electrode are considered cosmetic defects. While scratches do not pose a significant quality issue, chips and peeling are defects in the electrode and therefore considered defective in terms of quality.

Therefore, in the field of visual inspection of electronic components, from the perspective of improving yield, there is a demand for the development of inspection equipment that can only detect defects and peelings that pose quality problems.

The present invention was completed against this background, and its purpose is to provide an inspection device that can only detect defects and detachments on the electrode portion of an electronic component.

The present invention, which is intended to solve the above-mentioned technical problems, is an inspection device that transports an object to be inspected in a predetermined transport direction and inspects at least the front end or rear end of the object in the transport direction. The inspection device comprises: a transport mechanism having a transparent sheet-like transport sheet that moves along the transport direction, and the transport sheet transports the object to be inspected, placed on the transport sheet, in the transport direction; and a first illumination mechanism that illuminates the object with the transport sheet at a predetermined inspection position on a transport path formed by the transport sheet. The first lighting mechanism comprises: a first light emitter, which illuminates the inspected surface of the object to be inspected; a second lighting mechanism, which is arranged on the side opposite to the object to be inspected, and illuminates the inspected surface of the object to be inspected; and a photographing camera, which is arranged on the same side as the object to be inspected, and photographs the inspected surface of the object to be inspected at the inspection position, wherein the first lighting mechanism comprises: a plurality of first light emitters, which illuminate the inspected surface of the object to be inspected; and a first support body, which supports the plurality of first light emitters. The first support body is configured to support at least the first light emitter close to the conveying path at a position farther from the inspection position than the other group of first light emitters, and there is a space between the first light emitter farther away and the other group of first light emitters for observing the inspected surface of the inspected object from the back side on the side opposite to the inspection position, the photographing camera is configured to be arranged on the back side of the first support body, and to photograph the inspected surface of the inspected object through the space of the first support body, and the second lighting mechanism is arranged across the conveying sheet The first illumination mechanism is located in a plane-symmetrical position relative to the first illumination mechanism, and comprises: a plurality of second light emitters for illuminating the inspection surface of the inspection object; and a second support body for supporting the plurality of second light emitters. Half the beam angle of the first light emitters of the first illumination mechanism proximate to the transportation path and the second light emitters of the second illumination mechanism proximate to the transportation path is within a range of 30° to 80°, and half the beam angle of the other first light emitters of the first illumination mechanism and the other second light emitters of the second illumination mechanism is within a range of 10° to 25°.

Furthermore, the inspection object applicable to this inspection device is an electronic component composed of a base portion and an electrode portion, including at least a portion of the end surface of the base portion covered with a metal layer. The base portion is composed of a material having a lower light reflectivity than the electrode portion. In this inspection device, the end surface (inspected surface) of the electrode portion is inspected.

According to this inspection device, the object to be inspected is placed on a transparent transport sheet of a transport mechanism and transported by the movement of the transport sheet. Furthermore, at a predetermined inspection position on the transport path, the inspected surface is illuminated by a first light emitter (first B light emitter) and another set of first light emitters (first A light emitters) of a first illumination mechanism located near the transport path, and by a second light emitter (second B light emitter) and another set of second light emitters (second A light emitters) of a second illumination mechanism located near the transport path. The camera then captures the inspected surface. Furthermore, light emitted from the second A light emitter and the second B light emitter passes through the transparent transport sheet to illuminate the inspected surface of the object to be inspected.

In the first illumination mechanism, at least the first B light emitter is positioned farther from the inspection position than the first A light emitter. Therefore, while the first B light emitter is positioned as close as possible to the transport path of the transport mechanism, an appropriate distance can be set between the first B light emitter and the first A light emitter, and space can be provided in this portion for capturing images of the inspected surface of the object under inspection.

Furthermore, by adopting this structure, the camera can be positioned so that the angle (elevation angle) between its imaging optical axis and the transport path is as small as possible, that is, as close to the transport path as possible. This positioning allows the camera to capture the inspected surface of the object as closely as possible from the front. This allows the image of the inspected surface captured by the camera to be captured in a larger image, resulting in highly accurate inspection of the surface's appearance.

Furthermore, the 1/2 beam angle of each of the first B light emitter of the first lighting mechanism and the second B light emitter of the second lighting mechanism is within the range of 30° to 80°. Meanwhile, the 1/2 beam angle of each of the first A light emitter of the first lighting mechanism and the second A light emitter of the second lighting mechanism is within the range of 10° to 25°. In other words, the first A light emitter and the second A light emitter each emit light with relatively high directivity, while the first B light emitter and the second B light emitter emit light with relatively low directivity. Furthermore, the 1/2 beam angle refers to the internal angle in the irradiation direction of light having an intensity of 1/2 the maximum intensity, centered on the optical axis having the maximum intensity emitted from the light emitter.

Furthermore, the first and second illumination mechanisms enable the camera to capture images that emphasize only scratches, contact marks, defects, and peelings on the end surface of the electrode portion, thereby enabling the inspection object to be judged as defective based solely on the defects and peelings.

Specifically, the first B light emitter on the upper side and the second B light emitter on the lower side illuminate the inspected surface with relatively non-directional light, while the first A light emitter on the upper side and the second A light emitter on the lower side illuminate the inspected surface with directional light from an oblique direction. Therefore, if a scratch or contact mark is present on the inspected surface, the relatively non-directional light and the directional light irradiated from the upper and lower sides combine to illuminate the entire area of the concave portion where the scratch or contact mark is formed. As a result, light reflected from the entire area of the concave portion where the scratch or contact mark is formed enters the camera. Therefore, even if scratches or contact marks are present on the inspected surface, the image captured by the camera will be an image in which the scratches or contact marks are abstracted.

On the other hand, if a defect or peel exists on the inspected surface and the base portion is exposed at that location, the base portion has a lower light reflectivity than the electrode portion formed of the metal layer. Therefore, the amount of light reflected from the inspected surface that enters the camera is lower in the portion corresponding to the defect or peel. As a result, the image captured by the camera becomes darker in the portion corresponding to the defect or peel. Therefore, by processing the resulting image to detect this dark portion, defects such as defects or peels can be detected. This allows the system to detect defects or peelings on the inspected surface as defects only.

Furthermore, as described above, since the first and second B light emitters can be positioned as close as possible to the transport path, the camera can capture more reflected light from the inspected surface, thereby making the image captured by the camera clearer. This allows for a clear image of the inspected surface, enabling high-precision inspection of its appearance.

Furthermore, while LEDs can be representative examples of the first A light emitter, the first B light emitter, the second A light emitter, and the second B light emitter, they are not limited to any LEDs as long as they can illuminate the inspected surface with sufficient light intensity for inspection.

As described above, the inspection device of the present invention having the above-described structure can inspect the external appearance of the object being inspected with high precision. It also detects only defects and peelings that pose quality problems as defective, without detecting scratches or contact marks that pose no quality problems.

In the above-mentioned inspection device, it is preferred that the imaging camera be arranged so that its imaging optical axis is located within a plane perpendicular to the transport path and intersects the transport path at an angle within a range of 10° to 35°. Furthermore, the first B light emitter of the first illumination mechanism and the second B light emitter of the second illumination mechanism are arranged so that their illumination optical axes intersect the transport path at an angle within a range of 3° to 20°.

By setting the imaging optical axis of the camera and the illumination optical axes of the first and second B light emitters to angles within the aforementioned range, the image of the object under inspection captured by the camera can be made more appropriate, thereby enabling high-precision inspection of the inspection surface of the object under inspection.

In the above-mentioned inspection device, preferably, the first A light emitter and the first B light emitter of the first lighting mechanism, and the second A light emitter and the second B light emitter of the second lighting mechanism are configured so as to be individually dimmable.

By adjusting the intensities (illuminance) of the first A light emitter, the first B light emitter, the second A light emitter, and the second B light emitter, the brightness of the image of the inspected object captured by the camera can be uniform across the entire area. For example, if the first B light emitter is farther from the inspection position than the first A light emitter, the brightness of the inspected surface illuminated by the first B light emitter will be lower than that of the portion illuminated by the first A light emitter. However, by increasing the intensity of the first B light emitter, the brightness across the entire inspected surface can be made substantially uniform. Furthermore, if the shape of the inspected surface causes uneven brightness, the intensity of each light emitter can be adjusted according to the shape of the inspected surface to achieve substantially uniform brightness across the entire inspected surface.

As described in detail above, the inspection device of the present invention can inspect the appearance of the object with high precision. It also detects only defects and peelings that pose quality problems as defective, without detecting scratches or contact marks that pose no quality issues.

1: Inspection device

2: Transport mechanism

3: Rotating table

4: Take a photo

5: First Lighting Unit

6: First A support

7: End face

8: Lower surface

9: End face

10: Concave surface

11: Groove

12: First B light emitter

12a: Light Axis

12b: Light

13: First B support

14: End face

15: Lower surface

16: First A light emitter

16a: Light Axis

16b: Light

25: Second lighting mechanism

26: Second support body

27: End face

28: Lower surface

29: End face

30: Concave surface

31: Groove

32: Second B light emitter

33: Second support body B

34: End face

36: Second A light emitter

36a: Light Axis

50: Inspection device

A: Arrow

B: Direction

C: Direction

D: Direction

E: Direction

G1: LED group

G2: LED group

G3: LED Group

G4: LED Group

G5: LED Group

G6: LED Group

P: Check position

W: Object to be inspected

W ₁ : base

W ₂ : Electrode

W _a : front face, inspected face

θa: interior angle

θb: interior angle

[Figure 1] is a front view of an inspection device according to one embodiment of the present invention.

Figure 2 is an enlarged view of Figure 1, showing the first and second lighting mechanisms in cross-section.

Figure 3 is a side view taken along the B-B direction in Figure 2.

Figure 4 is a side view taken along the C-C direction in Figure 2.

Figure 5a (Figure 5a, 5b) shows a top view of the object being inspected, and Figure 5b shows a side view of the object in the direction D.

Figures 6a and 6b are diagrams used to illustrate the 1/2 beam angle of the LED used in this embodiment.

Figure 7 is a front view of an inspection device according to a modified example of this embodiment.

Specific embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a front view of an inspection device according to one embodiment of the present invention, and FIG. 2 is an enlarged front cross-sectional view of FIG. FIG. 3 is a side view taken along the line B-B in FIG. 2 , and FIG. 4 is a side view taken along the line C-C in FIG. 2 .

As shown in Figures 1 and 2, the inspection device 1 of this example includes: a conveying mechanism 2, which conveys the inspected object W in the direction of arrow A as the conveying direction; a first lighting mechanism 5 and a second lighting mechanism 25, both of which illuminate the front end surface (the end surface on the front side of the conveying direction) Wa of the inspected object _W conveyed by the conveying mechanism 2 at the inspection position P; and a photographing camera 4, which photographs the front end surface _Wa of the inspected object W located at the inspection position P.

In this example, the hexahedral electronic component shown in Figures 5a and 5b serves as the object to be inspected W, with its front end surface _Wa serving as the surface to be inspected. This electronic component consists of a base _W1 and electrodes _W2 disposed at each end of the base _W1 . The electrodes _W2 are formed by covering the base _W1 with a metal layer. Furthermore, the base _W1 is made of a material, such as ceramic, that has a lower light reflectivity than the electrodes _W2 .

Conveyor mechanism

The conveyor mechanism 2 includes a rotating table 3 for conveying sheets. The rotating table 3 is made of a transparent glass plate and is in the shape of a circular plate. A drive motor (not shown) rotates the rotating table 3 horizontally in the direction of arrow A. The rotating table 3 rotates, and the conveyor mechanism 2 conveys the inspection object W, which is fed onto the rotating table 3 with its front end _Wa facing in the conveying direction, in the conveying direction. The inspection object W, which is conveyed by the rotating table 3, naturally follows an arc-shaped path.

Shooting camera

The camera 4 is a camera that captures a two-dimensional image of the front end surface _Wa of the inspected object W. It is arranged at the inspection position P, with its shooting optical axis located in a vertical plane including the tangent of the transport path, and the angle formed with the upper surface of the turntable 3, i.e., the transport path, is in the range of 10° to 35°.

First Lighting Agency

As shown in Figures 2-4 , the first illumination mechanism 5 includes: a first A support 6; a first B support 13 fixed to the end surface 9 of the first A support 6 on the downstream side in the conveying direction; a plurality of LEDs 12 serving as first A light emitters supported on the first A support 6; and a plurality of LEDs 16 serving as first B light emitters supported on the first B support 13. The first illumination mechanism 5 is disposed downstream of the inspection position P in the conveying direction and above the turntable 3.

The first A-support 6 has a concave surface 10 extending from the upstream end surface 7 in the conveying direction toward the lower surface 8. The plurality of LEDs 12 are fixedly mounted on this concave surface 10. As shown in Figure 4 , these LEDs 12 are arranged on the concave surface 10 in three roughly concentric arc rows. In this example, seventeen LEDs 12 are arranged in the outermost arc row, thirteen LEDs 12 are arranged in the center arc row, and nine LEDs 12 are arranged in the centermost arc row.

Furthermore, the lower surface 8 of the first A support 6 is formed with a groove 11 that opens onto the end surface 9 on the downstream side in the conveying direction and the concave curved surface 10. The first B support 13 is fixed to the end surface 9 so as to close the opening on the end surface 9 side, leaving the upper side of the opening open.

On the other hand, a plurality of (in this example, four) LEDs 16 are arranged in a horizontal row on the upstream end surface 14 of the first B support 13 in the conveying direction. These LEDs 16 are located closer to the conveying path of the turntable 3 than the LEDs 12, and further away from the inspection position P in the conveying direction than the LEDs 12.

In addition, on the end face 9 of the first A support body 6, an opening is formed by the upper surface of the first B support body 13 and the inner surface of the groove 11, and the front end face _Wa of the inspection object W can be photographed through the opening by the photographing camera 4 whose photographing optical axis angle is set to the above-mentioned angle.

In this way, since LED16 serving as the first B light emitter is arranged at a position farther away from the inspection position P toward the transport direction than another group of LED12 serving as the first A light emitter, wherein the first B light emitter is arranged at a position close to the transport path of the turntable 3, a gap can be set between LED16 and LED12, thereby forming a space for photographing the front end surface _Wa of the inspected object W between the groove 11 formed on the first A support body 6 and the upper surface of the first B support body 13.

Furthermore, a gap is formed on the lower surface 15 of the first B support 13, which is in contact with the conveying path of the turntable 3 directly above, through which the inspection object W conveyed by the turntable 3 can pass.

The 1/2 beam angle of LED 12 is within the range of 10° to 25°, and the 1/2 beam angle of LED 16 is within the range of 30° to 80°. In other words, LED 12 emits light with relatively high directivity, while LED 16 emits light with relatively low directivity. Furthermore, the 1/2 beam angle is set as the internal angle in the irradiation direction of light with an intensity of 1/2 the maximum intensity, centered on the optical axis with the maximum intensity emitted from the light emitter.

Figures 6a and 6b illustrate the definition of the 1/2 beam angle. Figure 6a shows the case of LED 12. The 1/2 beam angle of LED 12 is defined as the internal angle θa of the direction of illumination of light beams 12b and 12b, each with an intensity 1/2 of the maximum intensity, centered on optical axis 12a, which has the maximum intensity of LED 12. Similarly, Figure 6b shows the case of LED 16. The 1/2 beam angle of LED 16 is defined as the internal angle θb of the direction of illumination of light beams 16b and 16b, each with an intensity 1/2 of the maximum intensity, centered on optical axis 16a, which has the maximum intensity of LED 16.

In addition, the LED 16 is arranged so that its optical axis 16a intersects the transmission path at an angle within the range of 3° to 20°.

Furthermore, the LEDs 12 arranged in the outermost arc row (LED group G1), the LEDs 16 arranged in other arc rows (LED group G2), and the LEDs 16 (LED group G3) can each have their light intensity adjusted.

Second lighting unit

The second illumination mechanism 25 has the same structure as the first illumination mechanism 5 and is positioned below the turntable 3 in a plane-symmetrical relationship with the first illumination mechanism 5. The following description will focus on the structure of the second illumination mechanism 25, although some explanations may be repeated.

The second lighting mechanism 25 includes: a second A support 26; a second B support 33 fixed to the end surface 29 of the second A support 26 on the downstream side in the conveying direction; a plurality of LEDs 32 serving as second A light emitters supported on the second A support 26; and a plurality of LEDs 36 serving as second B light emitters supported on the second B support 33.

The second A-support body 26 has a concave surface 30 extending from the upstream end surface 27 in the conveying direction toward the lower surface 28. The plurality of LEDs 32 are fixed to this concave surface 30. As shown in Figure 4, these LEDs 32 are arranged on the concave surface 30 in three roughly concentric arc rows. In this example, seventeen LEDs 32 are arranged in the outermost arc row, thirteen LEDs 32 are arranged in the center arc row, and nine LEDs 32 are arranged in the centermost arc row.

Furthermore, the lower surface 28 of the second A support 26 is formed with a groove 31 that opens into the end surface 29 on the downstream side in the conveying direction and the concave curved surface 30. The second B support 33 is fixed to the end surface 29 so as to close the opening on the end surface 29 side, leaving the upper side of the opening open.

On the other hand, on the upstream end surface 34 of the second B support 33 in the conveying direction, a plurality (in this example, four) of LEDs 36 are arranged in a horizontal row. These LEDs 36 are located closer to the conveying path of the turntable 3 than the LEDs 32, and are further away from the inspection position P in the conveying direction than the LEDs 32.

Furthermore, the half-beam angle (θa in Figure 6a) of LED 32 is within the range of 10° to 25°, emitting light with relatively high directivity. Furthermore, the half-beam angle (θb in Figure 6b) of LED 36 is within the range of 30° to 80°, emitting light with relatively low directivity. Furthermore, LED 36 is arranged so that its optical axis 36a, shown in Figure 6b, intersects the transmission path at an angle within the range of 3° to 20°.

Furthermore, the LEDs 32 arranged in the outermost arc row (LED group G4), the LEDs 36 arranged in other arc rows (LED group G5), and the LEDs 36 (LED group G6) can each be dimmed.

According to the inspection device 1 of this example having the above structure, on the rotating table 3 driven to rotate by the drive motor (not shown), multiple inspection objects W are supplied in sequence at specified intervals with their front end faces _Wa facing the conveying direction. The supplied inspection objects W pass through the rotating table 3 and are transported through the inspection position P.

The front end surface _Wa of the inspection object W that has reached the inspection position P is illuminated by light emitted from the LEDs 12 and 16 of the first illumination mechanism 5, and by light emitted from the LEDs 32 and 36 of the second illumination mechanism 25, and also by light transmitted through the turntable 3. Thus, by illuminating the front end surface _Wa with the first illumination mechanism 5 and the second illumination mechanism 25 positioned above and below, the front end surface _Wa can be uniformly illuminated with high illumination intensity.

Then, the photographing camera 4 photographs the front end surface _Wa of the inspection object W uniformly illuminated in this manner, and the photographed image data is analyzed by a determination device (not shown) to determine whether the appearance of the front end surface _Wa is good or not.

In addition, in the inspection device 1 of this example, the LED 16 of the first lighting mechanism 5 and the LED 36 of the second lighting mechanism 25 are arranged so that their lighting optical axes 16a and 36a intersect the transport path at an angle within the range of 3° to 20°, so that the front end surface _Wa of the inspected object W can be illuminated roughly from the front.

Furthermore, by positioning LED 16 of the first illumination unit 5 farther from the inspection position P than LED 12, an appropriate spacing can be established between LED 16 and LED 12, partially creating a space for capturing the front end surface _Wa of the inspection object W. Furthermore, by establishing such control, the imaging camera 4 can be positioned so that the angle (elevation angle) between its imaging optical axis and the transport path is within a range of 10° to 35°, thereby locating it as close to the transport path as possible.

In this way, according to the thus configured shooting camera 4, the front end surface _Wa of the inspection object W can be photographed from its front side as much as possible, thereby enabling the image of the front end surface _Wa photographed by the shooting camera 4 to be captured as a larger image, and as a result, the appearance characteristics of the front end surface _Wa can be inspected with high precision.

Furthermore, as described above, the LEDs 16 and 36 illuminate the front end surface _Wa of the object to be inspected W from the front. Therefore, the camera 4 can receive more reflected light from the front end surface _Wa , thereby making the image captured by the camera 4 clearer. Thus, by obtaining a clear image of the front end surface _Wa , the external appearance of the front end surface _Wa can be inspected with higher precision.

In addition, according to the inspection device 1, when there are scratches, contact marks, defects and peelings on the end surface _Wa of the electrode part _W2 , the following effect can make the image captured by the camera 4 an image that only emphasizes the defects and peelings. Based on this, it is possible to judge whether the inspected object W is good or not based only on the defects and peelings.

Specifically, relatively non-directional light is irradiated toward the inspection surface _Wa from the LED 16 of the first illumination mechanism 5 disposed above the rotating table 3 and the LED 36 of the second illumination mechanism 25 disposed below the rotating table 3, while directional light is irradiated obliquely toward the inspection surface _Wa from the LED 12 of the first illumination mechanism 5 and the LED 32 of the second illumination mechanism 25. Therefore, if a scratch or a contact mark is present on the inspection surface _Wa , the relatively non-directional light irradiated from the upper and lower sides is combined with the directional light to illuminate the entire area of the concave portion where the scratch or contact mark is formed. As a result, light reflected from the entire area of the concave portion where the scratch or contact mark is formed enters the camera. Therefore, even when there are scratches or contact marks on the inspection surface _Wa , the image captured by the imaging camera 4 is an image in which the scratches or contact marks are abstracted.

On the other hand, if a defect or peel exists on the inspection surface _{Wa and} the base portion _W1 is exposed at that location, the base portion _W1 has a lower light reflectivity than the electrode portion _W2 formed of a metal layer. Therefore, the amount of light reflected from the inspection surface _Wa that enters the camera 4 is lower in the portion corresponding to the defect or peel. As a result, the image captured by the camera 4 becomes darker in the portion corresponding to the defect or peel. Therefore, by processing the resulting image to detect this dark portion, defects such as defects or peels can be detected. Therefore, when there is a defect or peeling on the inspection surface _Wa , only the defect or peeling can be detected as a defect.

Furthermore, in this example, the first lighting mechanism 5 and the second lighting mechanism 25 can dim the LED groups G1, G2, G3, G4, G5, and G6 individually. Therefore, by appropriately dimming the LED groups G1, G2, G3, G4, G5, and G6, the front end surface _Wa can be uniformly illuminated. Furthermore, the dimming can be performed according to the shape of the front end surface _Wa , which is the inspected surface. If the shape of the inspected surface causes uneven brightness on the inspected surface, the intensity of each LED group G1, G2, G3, G4, G5, and G6 can be adjusted according to the shape of the inspected surface, thereby achieving approximately uniform brightness across the entire inspected surface.

In this way, according to the inspection device 1 of this example, the appearance characteristics of the front end surface _Wa of the inspected object W can be inspected with high precision. In addition, scratches and contact marks that are not a problem in terms of quality are not detected, and only defects and peeling that are a problem in terms of quality are detected as defective.

While the above describes specific embodiments of the present invention, the present invention is not limited to these specific embodiments. For example, in the above example, the front end surface _Wa of the inspection object W is inspected in the conveying direction. However, as shown in Figure 7 , the rear end surface _Wb of the inspection object W can also be inspected. This inspection device 50 reverses the conveying direction of the conveyor device 2 from direction A to direction E. Therefore, in Figure 7 , components identical to those of the inspection device 1 are designated with the same reference numerals. Since the structure and function of each component are identical to those of the inspection device 1, their description will be omitted.

1: Inspection device

2: Transport mechanism

3: Rotating table

4: Take a photo

5: First Lighting Unit

6: First A support

7: End face

8: Lower surface

9: End face

10: Concave surface

11: Groove

12: First B light emitter

13: First B support

14: End face

15: Lower surface

16: First A light emitter

25: Second lighting mechanism

26: Second support body

27: End face

28: Lower surface

29: End face

30: Concave surface

31: Groove

32: Second B light emitter

33: Second support body B

34: End face

36: Second A light emitter

A: Arrow

B: Direction

C: Direction

P: Check position

W: Object to be inspected

W _a : front face, inspected face

Claims (2)

An inspection device that transports an object to be inspected in a set transport direction and inspects at least the front end face or the rear end face of the object to be inspected in the transport direction, and is characterized in that it comprises: a transport mechanism having a transparent sheet-like transport sheet that moves along the transport direction, and the object to be inspected placed on the transport sheet is transported in the transport direction by the movement of the transport sheet; a first lighting mechanism that is arranged at a specified inspection position on a transport path formed by the transport sheet, on the same side as the object to be inspected, with the transport sheet as the boundary, and illuminates the inspected surface of the object to be inspected; a second lighting mechanism that is arranged at a specified inspection position on a transport path formed by the transport sheet, on the same side as the object to be inspected, with the transport sheet as the boundary, and illuminates the inspected surface of the object to be inspected; and a third lighting mechanism that is arranged at a specified inspection position on a transport path formed by the transport sheet, on the same side as the object to be inspected, with the transport sheet as the boundary, and illuminates the inspected surface of the object to be inspected. The first lighting mechanism comprises: a first light emitter, which is arranged on the side opposite to the object to be inspected, and illuminates the inspected surface of the object to be inspected; and a photographing camera, which is arranged on the same side as the object to be inspected, and photographs the inspected surface of the object to be inspected at the inspection position. The first lighting mechanism comprises: a plurality of first light emitters, which illuminate the inspected surface of the object to be inspected; and a first support body, which supports the plurality of first light emitters. The first support body is configured to support at least the first light emitter close to the transport path at a position farther from the inspection position than the other group of first light emitters, and to support the first light emitter, which is farther from the inspection position, at a position farther from the inspection position than the other group of first light emitters. The first support body has a space between the light emitters, which allows the inspection surface of the inspection object to be observed from the back side opposite to the inspection position. The camera is arranged on the back side of the first support body and photographs the inspection surface of the inspection object through the space of the first support body. The imaging light axis is located in a plane perpendicular to the conveying path and intersects the conveying path at an angle within the range of 10° to 35°. The second lighting mechanism is arranged at a position symmetrical to the first lighting mechanism across the conveying sheet, and comprises: a plurality of second light emitters, which illuminate the inspection surface of the inspection object; and a second support body. The first light emitter of the first lighting mechanism and the second light emitter of the second lighting mechanism near the transport path have a half-beam angle within a range of 30° to 80°, and the half-beam angle of the other first light emitters of the first lighting mechanism and the other second light emitters of the second lighting mechanism are within a range of 10° to 25°. Furthermore, the first light emitters of the first lighting mechanism and the second light emitters of the second lighting mechanism near the transport path are arranged so that their illumination optical axes intersect the transport path at an angle within a range of 3° to 20°. The inspection device according to claim 1 is characterized in that it is configured to separately dim the first light emitter and other first light emitters of the first lighting mechanism that are close to the transmission path, and the second light emitter and other second light emitters of the second lighting mechanism that are close to the transmission path.