TWI470251B - Photoelectric detection system - Google Patents

Description

Photoelectric detection system

The present disclosure relates to a photodetection system.

As thin-film solar cells, touch panels, and flexible displays continue to thrive, they must be tested to ensure product quality during product manufacturing. In the past, the probe contact type electrical detection equipment was used, and the sampling inspection method was adopted as the quality control mechanism; however, as the production size of the product became larger and larger, the processing speed became faster and faster, and the line width of the process became smaller and smaller, The demand for high-speed image detection equipment is also receiving more and more attention.

In the manufacturing process of the above products, one of the processes is a laser etching process of transparent conductive patterns. If the etching is incomplete, the pixels will form a dead pixel, resulting in a decrease in yield. In the laser etching process, transparent conductive patterns may also cause defects such as short/open circuits, scratches, and impurities. Since the conductive pattern is transparent, the conventional photodetection system cannot obtain an etching condition of a transparent conductive film pattern such as ITO or AZO. The conventional non-contact photodetection system is only suitable for single sheet (Sheet by Sheet) process inspection and is not suitable for roll to roll process inspection. How to directly perform defect detection through appearance and provide better precision, fast and accurate measurement quality of the roll process, which will be a problem that the photoelectric detection system needs to solve in the future.

Therefore, in view of the above problems, the present disclosure provides a photoelectric inspection The measurement method is suitable for defect detection of a transparent conductive pattern of a roll process.

The present disclosure provides a photodetection system comprising: a circuit rotary connector and a photodetection roller. The circuit rotary connector includes an external fixing portion and an inner rotating portion, and is supplied with power from an external power source through the external fixing portion. The inner rotating portion and the outer fixing portion are connected through a rotary bearing, and the inner rotating portion rotates as the photodetecting roller rotates, and the inner rotating portion has a first terminal and a second terminal. The photo-sensing roller includes a roller, a photoelectric layer and at least one conductive ring. The outer side of the roller is covered with a metal layer electrically connected to the first terminal. The photovoltaic layer is coated on the outer side of the metal layer, and a side of the photovoltaic layer and the metal layer is applied with a first voltage by the metal layer. The conductive ring is disposed on an axial outer side of the photo-sensing roller and electrically connected to the second terminal having a second voltage. The first voltage and the second voltage have a predetermined voltage difference, and when a film to be tested is attached to the photo-sensing roller, the conductive ring applies a second voltage to one of the conductive patterns on the film to be tested, so that the photoelectric The layer controls the light transmittance of the photoelectric layer corresponding to a portion of the conductive pattern according to a voltage difference between the conductive pattern and the metal layer.

1‧‧‧Photoelectric detection system

2‧‧‧Circuit Rotating Connector

3‧‧‧Photoelectric detection wheel

4‧‧‧External power supply

5‧‧‧ diaphragm

6‧‧‧ conductive pattern

7‧‧‧ terminal electrode

8‧‧‧ lead

9‧‧‧ITO electrodes

10‧‧‧ camera

11‧‧‧Electronic computer

12‧‧‧Light source

BS‧‧‧beam splitter

21‧‧‧ External fixation

22‧‧‧Internal rotation

31‧‧‧roller

32‧‧‧Black metal plating

32'‧‧‧Metal reflector

33‧‧‧Photoelectric layer

34‧‧‧Transparent coverage

35‧‧‧ Conductive ring

36‧‧‧Insulation ring

Embodiments of the present disclosure will now be described in more detail with reference to the accompanying schematic drawings in which:

1A and 1B illustrate the detection principle of the photodetection system of the present disclosure.

2A is a schematic diagram of an embodiment of the photodetection system of the present disclosure.

2B is a schematic diagram of another embodiment of the photodetection system of the present disclosure.

Figure 3A is a y-axis view of an embodiment of the photodetection system of the present disclosure.

Figure 3B is a view of the x-axis direction (a-a' connection) of an embodiment of the photodetection system of the present disclosure.

Figure 3C is an x-axis view (c-c' connection) of an embodiment of the photodetection system of the present disclosure.

Figure 3D is an x-axis view (b-b' connection) of an embodiment of the photodetection system of the present disclosure.

Figure 3E is a z-axis view of an embodiment of the photodetection system of the present disclosure.

Figure 3F is an x-axis view (b-b' connection) of an embodiment of the photodetection system of the present disclosure.

Figure 3G is a z-axis view of an embodiment of the photodetection system of the present disclosure.

Figure 4 is a schematic view of another embodiment of the photodetection system of the present disclosure.

The disclosure will be described below in conjunction with the drawings.

When the detailed description of the related art can avoid unnecessary confusion of the subject matter of the present invention, the description thereof will be omitted. In addition, the following terms, whose definitions take into account the functions disclosed herein, may vary depending on the user's intention or judicial precedent. Therefore, the meaning of each term should be interpreted based on the entire disclosure of this specification.

1A and 1B illustrate the detection principle of the photodetection system of the present disclosure. 2A is a schematic diagram of an embodiment of the photodetection system of the present disclosure. 2B is a schematic diagram of another embodiment of the photodetection system of the present disclosure. 3A to 3E are respectively three views of an embodiment of the photodetection system of the present disclosure. Figure 4 is a schematic view of another embodiment of the photodetection system of the present disclosure.

Referring to FIG. 1A, the film structure represents a portion of the photo-sensing roller, and the film layer structure is a black metal plating layer 32, a photovoltaic layer 33, a transparent covering surface 34, and a transparent ITO electrode 9 from bottom to top, wherein the ITO electrode 9 is not even The continuation part is the disconnection part. The transparent cover 34 is located on the opposite side of the black metal plating 32 and serves to protect the photovoltaic layer 33. The photo-electric layer 33 is a polymer dispersed liquid crystal (PDLC). When a voltage is applied to both sides of the PDLC, the PDLC and the polymer material doped therein have similar refractive indices, so the PDLC is transparent. When no voltage is applied to both sides of the PDLC (or below the driving voltage), the PDLC appears milky white because the liquid crystal molecules scatter light.

In the present embodiment, it is assumed that the ITO electrode 9 is applied with a positive voltage, and the ferrous metal layer 32 is applied with a negative voltage. Since the photovoltaic layer 33 interposed between the ferrous metal layer 32 and the ITO electrode 9 is applied with voltage on both sides, the photovoltaic layer 33 is transparent to allow incident light to penetrate. When the incident light passes through the transparent photovoltaic layer 33, the black metal plating layer 32 completely absorbs the incident light, so there is no reflected light. When the ITO electrode 9 has an open circuit, since the photovoltaic layer under the disconnected portion of the ITO electrode 9 is not applied with a positive voltage, the photovoltaic layer 33 appears milky white and partially reflects the incident light. The reflected light (bright portion) reflected from the photovoltaic layer 33 has the same contour as that of the broken portion of the ITO electrode 9. Further, the portion (dark portion) where no light is reflected has the same contour as that of the ITO electrode 9. In other words, the outline of the reflected light of the ITO electrode 9 or its disconnected portion is the same as that of the ITO electrode 9, and the difference is only that the dark portion indicates the ITO electrode 9, and the bright portion indicates the broken portion of the ITO electrode 9. Therefore, a camera (ie, a phase module) is disposed above the film layer and an electronic computer respectively receives and records the reflected light reflected from the photoelectric layer 33, thereby obtaining a contour image of the ITO electrode 9. Further, it is possible to judge whether or not the ITO electrode 9 has a disconnecting portion based on the brightness and darkness of the contour image of the ITO electrode 9. In the present embodiment, the dark portion represents the portion having the ITO electrode 9, and the bright portion represents no A portion having an ITO electrode 9 (i.e., a broken portion). In other words, when the photovoltaic layer 33 is rendered transparent, the black metal plating 32 will completely absorb the incident light, so the reflectance at this time is the first reflectance (for example, zero). When the photovoltaic layer 33 exhibits a milky white color, the photovoltaic layer 33 reflects a portion of the incident light, and thus the reflectance is higher than the second reflectance of the first reflectance.

Referring to FIG. 1B, the film layer structure represents a portion of the photo-sensing roller, and the film layer structure is a metal reflective layer 32', a photovoltaic layer 33, a transparent cover surface 34, and a transparent ITO electrode 9, respectively, from bottom to top, wherein the ITO electrode 9 The discontinuous part is the disconnected part. The transparent cover 34 is located on the opposite side of the metal reflective layer 32' and serves to protect the photovoltaic layer 33. As described above, the photovoltaic layer 33 is a PDLC.

In the present embodiment, we assume that the ITO electrode 9 is applied with a positive voltage and the metal reflective layer 32' is applied with a negative voltage. Since the photovoltaic layer 33 interposed between the metal reflective layer 32' and the ITO electrode 9 is applied with voltage on both sides, the photovoltaic layer 33 is transparent to allow incident light to penetrate. When the incident light passes through the transparent photovoltaic layer 33, the metallic reflective layer 32' completely reflects the incident light. When the ITO electrode 9 has an open circuit, since the photovoltaic layer under the disconnected portion of the ITO electrode 9 is not applied with a positive voltage, the photovoltaic layer 33 appears milky white and partially reflects the incident light. The difference from Fig. 1A is that since the ferrous metal layer 32 is replaced by the metal reflection layer 32', there is reflected light regardless of the ITO electrode 9 or the disconnected portion. Since the incident light is completely reflected by the metal reflective layer 32', the ITO electrode 9 has a strong reflected light. Since the incident portion of the ITO electrode 9 is only partially reflected by the photovoltaic layer 33, the reflected light is weak. Strong reflected light is defined as a bright portion, and weak reflected light is defined as a dark portion. Therefore, a camera and an electronic computer are disposed above the film layer to respectively receive and record the reflected light reflected from the photoelectric layer 33, thereby obtaining the wheel of the ITO electrode 9. Profile image. Further, it is possible to judge whether or not the ITO electrode 9 has a disconnecting portion based on the brightness and darkness of the contour image of the ITO electrode 9. In the present embodiment, the dark portion where the reflected light is weak represents the portion having no ITO electrode 9 (i.e., the broken portion), and the bright portion where the reflected light is strong represents the portion having the ITO electrode 9. In other words, when the photovoltaic layer 33 is transparent, the metal reflective layer 32' will completely reflect the incident light, so the reflectance at this time is the first reflectance. When the photovoltaic layer 33 exhibits a milky white color, the photovoltaic layer 33 reflects only a portion of the incident light, and thus the reflectance is lower than the second reflectance of the first reflectance.

Referring to Figure 2A, a schematic diagram of an embodiment of the present photodetection system is shown. The photodetection system 1 includes a rotating electrical connector 2 and a photo-sensing roller 3. The circuit rotary connector 2 drives the photo-sensing roller 3 to rotate by the power supplied from the external power source 4. Figure 2B shows a schematic diagram of another embodiment of the photodetection system of the present disclosure. The difference between FIG. 2B and FIG. 2A is that the terminal electrode 7 and the lead 8 on the diaphragm 5 are disposed only on one side of the diaphragm (left side of the diaphragm), and the other side of the diaphragm (on the right side of the diaphragm) is not provided. Terminal electrode 7 and lead 8. Therefore, among the photodetecting roller 3, the terminal electrode 7 and one side of the lead 8 (the left side of the diaphragm) are disposed correspondingly with a conductive ring and an insulating ring, and the side of the terminal electrode 7 and the lead 8 (the right side of the diaphragm) are not provided. The conductive ring and the insulating ring are not provided.

The photo-sensing measuring roller 3 has a cylindrical shape and is engaged with the circuit rotary connector 2 and rotated about the rotating shaft by the rotation of the circuit rotating connector 2. The diaphragm 5 is a flexible PE plastic having a conductive pattern 6 plated thereon. The conductive pattern 6 includes a terminal electrode 7, a lead 8, and a transparent ITO (Indium-tin oxide electrode) electrode 9. When the diaphragm 5 is attached to the surface of the photo-sensing roller 3 and rolls, The electric pattern 6 is in contact with the radially outer side of the photo-sensing roller 3.

The photodetection system 1 further includes a camera 10 and an electronic computer 11. In some embodiments, camera 10 can be viewed as an imaging module for converting a beam of light reflected by a photovoltaic layer into an image signal. For example, camera 10 can be a line scan camera that receives reflected light from a linear region when reflected light is reflected from ferrous metal layer 32 or reflective metal layer 32'. The computer 11 is coupled to the camera 10 and records the reflected light received by the camera 10 to obtain a contour image of the ITO. Further, it is possible to judge whether or not the ITO electrode 9 has a disconnected portion based on the brightness and darkness of the outline image of the ITO electrode 9 in the electronic computer 10.

Figure 3A is a y-axis view of an embodiment of the photodetection system of the present disclosure. Fig. 3A shows the cross-sectional direction of the photodetecting roller in the radial direction. As shown in Fig. 3A, the diaphragm 5 has an ITO electrode 9. When the diaphragm 5 is attached to the surface of the photodetecting roller 3, the ITO electrode 9 is in contact with the transparent covering surface 34. In the present embodiment, in order to simplify the explanation, it is assumed that the ITO electrode 9 is applied with a positive voltage, and the ferrous metal layer 32 is applied with a negative voltage. Since the photovoltaic layer 33 interposed between the ferrous metal layer 32 and the ITO electrode 9 is applied with voltage on both sides, the photovoltaic layer 33 is transparent to allow incident light to penetrate. When the incident light passes through the transparent photovoltaic layer 33, the black metal plating layer 32 completely absorbs the incident light, so that the portion of the diaphragm 5 having the ITO electrode 9 becomes a dark portion because there is no reflected light. When the diaphragm 5 rolls to a portion of the diaphragm 5 that does not have the ITO electrode 9 (for example, a hatched portion), since the portion of the diaphragm 5 that does not have the ITO electrode 9 is not subjected to a positive voltage, the photovoltaic layer is not applied thereto. The layer 33 is milky white and partially reflects the incident light, so that the portion of the film 5 having the ITO electrode 9 becomes a bright portion because it has reflected light. According to the image received by the camera (not shown here), whether it is light or dark, it can be judged whether the film is on the film. It has an ITO electrode.

Fig. 3B is a view of the x-axis direction of the embodiment of the photodetection system of the present invention (a-a' line seen from the x-axis direction). Fig. 3B shows the cross-sectional direction of the photodetecting roller in the axial direction. As shown in FIG. 3B, the circuit rotary connector 2 includes an outer fixing portion 21 and an inner rotating portion 22, and the circuit rotary connector 2 is supplied with power from the external power source 4 through the outer fixing portion 21. The inner rotating portion 22 is connected to the outer fixing portion 21 through the rotary bearing, and the inner rotating portion 22 is rotated in accordance with the rotation of the photodetecting roller 3. The inner rotating portion 22 has a positive terminal (+) and a negative terminal (-). In some embodiments, the negative terminal (-) can be regarded as a first terminal, and the positive terminal (+) can be regarded as a second terminal, but is not limited thereto. In some embodiments, the inner rotating portion 22 is rotated by a power source supplied from the external power source 4.

Referring to FIG. 3B, the photodetecting roller 3 includes a roller 31, a black metal plating layer 32, a photovoltaic layer 33, a transparent covering surface 34, a conductive ring 35, and an insulating ring 36. The roller 31 serves as a central axis of the photoelectric detecting roller about the axis of rotation, and the outer side thereof is covered with a black metal plating layer 32. The black metal plating layer 32 is electrically connected to the negative terminal (-) of the inner rotating portion 22, and is capable of conducting and absorbing incident. Light. The photovoltaic layer 33 is coated on the outer side of the ferrous plating layer 32, and a side of the photovoltaic layer 33 in contact with the ferrous metal plating layer 32 is applied with a negative voltage by the ferrous metal plating layer 32. The transparent cover 34 covers the other side of the photovoltaic layer 33 that is not in contact with the black metal plating 32 and protects the photovoltaic layer 33.

The conductive ring 32 is disposed at both axial ends of the photoelectric rod measuring roller 3, and is electrically connected to the positive terminal (+). An insulating ring 36 is disposed between each of the conductive rings 35 and the photodetecting roller 3, and electrically insulates each of the conductive rings 35 from the photovoltaic layer 33 of the photodetecting roller 3.

When the diaphragm 5 is rolled against the transparent cover surface 34 of the surface of the photodetecting roller 3, the terminal electrode 7 is in contact with the conductive ring 35, and the lead 8 is transmitted through the lead 8 so that the ITO electrode 9 is applied with a positive voltage. The image shown in Fig. 3B is an ITO electrode having no disconnecting portion. Since the positive and negative voltages are applied to the upper and lower sides of the photovoltaic layer 33, the photovoltaic layer 33 is transparent and the incident light is completely absorbed by the black metal plating layer 32, so that it is imaged by the camera. There is no reflected light in the linear area. In other words, when the ITO electrode 9 is intact and there is no open circuit, the image can be imaged by the camera, and we can observe the dark portion of the line in the electronic computer. In some embodiments, the negative voltage can be regarded as a first voltage, and the positive voltage can be regarded as a second voltage, and there is a predetermined voltage difference between the positive and negative voltages, but is not limited thereto.

Figure 3C is also a view of the x-axis direction of the embodiment of the photodetection system (viewing the c-c' line in the x-axis direction). The photodetection roller and the circuit rotary connector shown in FIG. 3C are identical to those shown in FIG. 3B, and will not be described again for simplification of the description. Unlike FIG. 3B, FIG. 3C shows the diaphragm 5 without the ITO electrode. Since the photovoltaic layer 33 does not have an ITO electrode thereon, the photovoltaic layer 33 applies a negative voltage only on one side of the contact with the black metal plating 32, so the photovoltaic layer 33 appears milky white and reflects incident light, and has reflection in a linear region imaged by the camera. Light. In other words, when the diaphragm 5 has no ITO electrode at all, through the camera imaging, we can observe the bright portion of the line in the electronic computer.

Fig. 3D is a view of the x-axis direction of the embodiment of the photodetection system of the present disclosure (viewing the b-b' line in the x-axis direction). Unlike FIG. 3B, FIG. 3C shows the diaphragm 5 having the ITO electrode 9 and the breaking portion (hatched portion). It can be seen from the foregoing description that when the ITO electrode 9 is provided above the photovoltaic layer 33 and positive and negative voltages are applied to both sides, the photovoltaic layer 33 is transparent, and the black metal plating layer 32 is completely absorbed. Incident light. Therefore, there is no reflected light in the linear region imaged by the camera to present a dark portion. Further, when a negative voltage is applied to the side of the photovoltaic 33 layer which does not have the ITO electrode 9 and is only in contact with the black metal plating layer 32, the photovoltaic layer 33 exhibits a milky white color and partially reflects the incident light. Therefore, there is reflected light in the linear region imaged by the camera to present a bright portion.

Figure 3E is a Z-axis direction view of an embodiment of the photodetection system of the present disclosure. When the diaphragm 5 is attached to the surface of the photodetecting roller 3, the terminal electrode 7 of the conductive pattern 6 is brought into contact with the conductive ring 35 to be applied with a positive voltage, and then the ITO electrode 9 is applied with a positive voltage by the lead 8. Taking the black metal plating layer 32 on the outer side of the roller as an example, when both positive and negative voltages are applied to both sides of the photovoltaic layer 33 (the ITO electrode is provided above the photovoltaic layer) and the ITO electrode 9 is completely open, we should be able to observe the complete linear dark portion. When the ITO electrode 9 has a disconnecting portion, the ITO contour image observed by us should be a linear dark portion, but with a partial bright portion therebetween, wherein the dark portion represents the diaphragm 5 having the ITO electrode 9, and the bright portion represents that the diaphragm 5 does not have the ITO electrode. 9 (breaking part). Taking the outer side of the roller as the metal reflective layer 32' as an example, when both positive and negative voltages are applied on both sides of the photovoltaic layer 33 (the ITO electrode is present on the photovoltaic layer) and the ITO electrode 9 is completely open, we should be able to observe the complete linear bright portion. . When the ITO electrode 9 has a broken portion, the ITO contour image observed by us should be a linear bright portion, but with a partial dark portion therebetween, wherein the bright portion represents the diaphragm 5 having the ITO electrode 9, and the dark portion represents the diaphragm 5 having no ITO electrode. 9 (breaking part). In short, when a film to be tested is attached to the photo-sensing roller 3, the conductive ring 35 applies a positive voltage (second voltage) to the conductive pattern 6 on the film to be tested, so that the photo-electric layer 33 is a voltage difference between the conductive pattern 6 and the metal layer (ie, the black metal plating layer 32 or the metal reflective layer 32'), and the control photoelectric layer 33 corresponds to the conductive pattern 6 Part of the light transmission.

As described in the embodiment of Fig. 2B, in some embodiments, the terminal electrode 7 and the lead 8 are disposed only on one side of the diaphragm, and the other side of the diaphragm is not provided with the terminal electrode 7 and the lead 8. In the embodiment shown in Fig. 3F, the ITO electrode 9 having the disconnecting portion is shown, and the photodetecting roller 3 is provided with the conductive ring 35 and the insulating ring 36 only on one side where the terminal electrode 7 and the lead 8 are disposed. In the present embodiment, the ITO electrode 9 is positively charged by the electrical coupling of the terminal electrode 7 and the lead 8. Further, the ferrous metal plating layer 32 is negatively charged, and therefore, the ITO contour image corresponding to the right side of the ITO electrode 9 is a dark portion. Since the ITO electrode disconnection portion is not charged, a sufficient voltage difference cannot be formed with the black plating layer under it, and therefore the ITO contour image corresponding to the disconnection portion of the ITO electrode 9 is a bright portion. Further, although the left side of the ITO electrode 9 (the left side of the ITO electrode) still has an ITO electrode, since it is not electrically coupled to the terminal electrode 7 and the lead 8, the corresponding ITO contour image on the left side of the ITO electrode is a bright portion. By the above method, we can know from the contour image of the ITO electrode that the ITO electrode has a disconnected portion and a position at which the disconnected portion starts (ie, the junction between the right side of the ITO electrode and the disconnected portion), because in practical applications, usually only It is known whether the ITO electrode has an open circuit and a disconnected position.

Figure 3G is a Z-axis view of an embodiment of the photodetection system of the present disclosure. In the embodiment shown in Fig. 3G, the terminal electrode 7 and the lead 8 are disposed only on one side of the diaphragm, and the other side of the diaphragm is not provided with the terminal electrode 7 and the lead 8. Among the photodetecting rollers 3, the side of the terminal electrode 7 and the lead 8 are not provided, and the conductive ring and the insulating ring are not provided correspondingly.

Figure 4 is a schematic view of another embodiment of the photodetection system of the present disclosure. Photodetection system different from Figure 2A (or Figure 2B), 4th The photodetection system 1 shown in the figure includes a plurality of photodetection rollers 3, and other constituent elements of the photodetection system 1 are the same as those of the photodetection system shown in FIG. 2A (or FIG. 2B), and are not described herein again. As shown in FIG. 4, when the diaphragm 5 rolls over the plurality of photodetecting rollers 3, the light source 12 generates light, and after being split by the beam splitter BS, incident light incident on the photovoltaic layer is formed, and after the reflected light passes through the beam splitter BS, Camera 10 receives the reflected light and forms a contour image of the ITO electrode.

The present invention has been described with reference to the accompanying drawings, and it should be understood by those of ordinary skill in the art that the present invention can be modified without departing from the scope and spirit of the invention and the scope of the claims. , additions, deletions and replacements. In addition, the method steps disclosed in the scope of the disclosure are only for explaining the photodetection method of the present disclosure, and are not intended to limit the order of steps of the method, and those skilled in the art should be able to know without departing from the invention and the patent application. Under the premise of the scope and spirit of the scope, some changes, additions, deletions and replacements can be made.

1‧‧‧Photoelectric detection system

2‧‧‧Circuit Rotating Connector

3‧‧‧Photoelectric detection wheel

4‧‧‧External power supply

5‧‧‧ diaphragm

6‧‧‧ conductive pattern

7‧‧‧ terminal electrode

8‧‧‧ lead

9‧‧‧ITO electrodes

10‧‧‧ camera

11‧‧‧Electronic computer

Claims (10)

A photoelectric detecting system comprising: a circuit rotating connector, wherein the circuit rotating connector comprises an external fixing portion and an inner rotating portion, and the external fixing portion is supplied with a power source by an external power source, the inner rotating portion and the above The outer fixing portion is connected through a rotating bearing, and the inner rotating portion rotates according to the rotation of the photoelectric detecting roller, the inner rotating portion has a first terminal and a second terminal; and a photo-sensing measuring roller comprises: a roller, the outer side of the roller is covered with a metal layer, the metal layer is electrically connected to the first terminal; a photoelectric layer, the photoelectric layer is coated on the outer side of the metal layer, and the photoelectric layer is in contact with the metal layer One side is applied with a first voltage by the metal layer; and at least one conductive ring is disposed on an axial outer side of the photo-sensing roller and electrically connected to the second terminal having a second voltage The first connection voltage and the second voltage have a predetermined voltage difference, and when a film to be tested is attached to the photo-electricity measuring roller The conductive ring applies the second voltage to one of the conductive patterns on the film to be tested, so that the photoelectric layer controls the photoelectric layer to correspond to a portion of the conductive pattern according to a voltage difference between the conductive pattern and the metal layer. Light transmission. The photodetection system of claim 1, further comprising an image capturing module for converting the light beam reflected by the photoelectric layer into an image signal. The photodetection system of claim 2, wherein the image capturing module is a line scan camera. The photodetection system of claim 2, wherein the metal layer is a black metal plating layer. The photodetection system of claim 4, wherein when the conductive pattern on the film to be tested is applied with the second voltage, the portion of the photo-electric layer corresponding to the conductive pattern is transparent, such that the black The portion of the conductive layer corresponding to the conductive pattern reflects an incident light back to the image capturing module by a first reflectance, and the portion of the photovoltaic layer that does not correspond to the conductive pattern exhibits milky white color and a second reflectance The incident light is partially reflected back to the image capturing module, and the first reflectance is lower than the second reflectance. The photodetection system of claim 2, wherein the metal layer is a metal reflective layer. The photodetection system of claim 6, wherein when the conductive pattern on the film to be tested is applied with the second voltage, the portion of the photo-electric layer corresponding to the conductive pattern is transparent, such that the metal The reflective layer corresponding to the portion of the conductive pattern reflects an incident light back to the image capturing module by a first reflectivity, and the portion of the photovoltaic layer that does not correspond to the conductive pattern exhibits milky white color and a second reflectivity The incident light is partially reflected back to the image capturing module, and the first reflectance is higher than the second reflectance. The photodetection system of claim 1, further comprising at least one insulating ring, wherein the insulating ring is disposed between each of the conductive rings and an axial direction of the photo-sensing roller, and the conductive ring is It is electrically insulated from the above-mentioned photo-electricity measuring roller. The photodetection system of claim 1, further comprising a transparent cover surface covering the other side of the photoelectric layer and protecting the photoelectric layer. The photodetection system of claim 1, wherein the photovoltaic layer is a polymer dispersed liquid crystal.