JP2020201086A - Inspection device of led-mounted substrate - Google Patents

Abstract

To provide an inspection device of an LED-mounted substrate that can inspect the luminance and chromaticity of an LED with a simple structure and at low cost.SOLUTION: An LED-mounted substrate 100 is fixed to a fixing bench. A detection unit 30 is mounted with a plurality of color sensors 31 so that a position relation of the plurality of color sensors 31 is the same as a position relation of a plurality of LEDs on the LED-mounted substrate 10. A microcomputer 51 of a control unit 50 transmits a lighting pattern signal to the plurality of LEDs while capturing a digital signal value of each color of RGB output by each color sensor 31 when the plurality of LEDs are lit according to the lighting pattern signal, inspects the luminance and chromaticity of each LED based on the captured digital signal value, and determines the acceptance/rejection of the LED-mounted substrate 100 based on the inspection result. A result output unit 60 outputs a determination result of the LED-mounted substrate 100 transmitted from the control unit 50.SELECTED DRAWING: Figure 3

Description

The present invention relates to an LED-mounted substrate inspection device that inspects an LED-mounted substrate on which a plurality of LEDs (Light Emitting Diodes) are mounted.

For example, a game machine such as a pachinko machine or a rotating body type game machine is provided with a plurality of production means for performing various effects according to the situation of the game. Among such effect means, there is one that displays an image, characters, or the like by lighting a plurality of LEDs in a desired lighting pattern. These a plurality of LEDs are mounted on a substrate, and in the manufacturing process of the game machine, the LED-mounted substrate on which the plurality of LEDs is mounted is inspected.

Currently, various inspection devices have been proposed for inspecting such LED-mounted substrates. Specifically, an inspection device (see, for example, Patent Document 1) that directly images the entire LED mounting substrate with an imaging means such as a camera and confirms the brightness and chromaticity of the LED based on the captured image. An inspection device (for example, a patent) in which an optical fiber is arranged directly above each LED, light from an LED guided by each optical fiber is photographed by an imaging means, and the brightness and chromaticity of the LED are confirmed based on the captured image. Refer to Reference 2.) Etc.

Japanese Unexamined Patent Publication No. 11-2018868 Patent No. 4530429

By the way, not only a plurality of LEDs but also many other electronic components are mounted on the LED mounting substrate. When inspecting an LED-mounted substrate using an inspection device that captures the entire LED-mounted substrate with an imaging means, for example, a tall electronic component may exist as an obstacle between the LED and the imaging means. In this case, the light from those LEDs is blocked by the obstacle and cannot be imaged by the imaging means, so that an accurate inspection cannot be performed. Not limited to tall electronic components, for example, a jig required for fixing the LED mounting substrate to the inspection device can be an obstacle. Further, in an inspection device that captures light from an LED by an imaging means via an optical fiber, it is difficult to arrange a plurality of optical fibers corresponding to the plurality of LEDs if the LEDs are densely mounted on the LED mounting substrate. Therefore, it is not possible to perform an accurate inspection. Further, any of the above inspection devices requires an imaging means and a personal computer for processing image data captured by the imaging means, so that there is a problem that the cost required for the inspection is very high.

The present invention has been made based on the above circumstances, and an object of the present invention is to provide an LED mounting substrate inspection device capable of inspecting the brightness and chromaticity of an LED with a simple structure and at low cost. Is.

The present invention for achieving the above object is an LED mounting board inspection device for inspecting an LED mounting board on which a plurality of LEDs are mounted, and is a fixing means for fixing the LED mounting board and each RGB color of incident light. It has a plurality of color sensors that detect components and output them as digital signals, and the positions of the plurality of color sensors are determined according to the positional relationship of the plurality of LEDs on the LED mounting substrate, and a plurality of color sensors are determined at the time of inspection. A detection means in which the color sensors of the above are arranged so as to face a plurality of LEDs at a constant interval, and lighting for lighting each LED in a predetermined lighting pattern on a plurality of LEDs mounted on an LED mounting substrate at the time of inspection. Along with transmitting the pattern signal, the digital signal value of each RGB color output by each color sensor when a plurality of LEDs are lit according to the lighting pattern signal is captured, and based on the digital signal value of each RGB color of each captured color sensor. A control means that inspects each LED mounted on the LED mounting board and determines the pass / fail of the LED mounting board based on the inspection result, and an output means that outputs the determination result of the LED mounting board sent from the control means. , Is provided.

In the LED-mounted substrate inspection device according to the present invention, the positions of a plurality of color sensors are determined according to the positional relationship of the plurality of LEDs on the LED-mounted substrate, and a plurality of color sensors are used during the inspection. The detection means arranged so as to face the LEDs at regular intervals, and the digital signal values of each RGB color output by each color sensor when a plurality of LEDs are lit according to a predetermined lighting pattern signal are captured and each of the captured digital signals. It is provided with a control means for inspecting each LED mounted on the LED mounting substrate based on the digital signal value of each RGB color of the color sensor and determining the pass / fail of the LED mounting substrate based on the inspection result. Therefore, the LED-mounted substrate inspection device according to the present invention is different from the conventional inspection device in which the light from each LED is imaged by the imaging means via the optical fiber or the entire LED-mounted substrate is imaged by the imaging means. Unlike this, it is not necessary to use an imaging means or a personal computer or the like for processing the image data captured by the imaging means, so that the LED can be inspected with a simple structure and at low cost.

Further, in the LED mounting substrate inspection device according to the present invention, the plurality of color sensors are attached to the detection means so that each color sensor has a one-to-one correspondence with each LED on the LED mounting substrate, and the control means. Captures the digital signal values of each RGB color output by each color sensor when a plurality of LEDs are lit according to the lighting pattern signal, and the captured digital signal values of the RGB colors of each color sensor correspond to the color sensor. It is desirable to inspect the brightness and / or chromaticity of each LED mounted on the LED mounting substrate by comparing the gradation value of each color with respect to the lighting pattern signal of the LED with a predetermined reference value. As a result, one color sensor detects the illuminance of the light from one LED, so that the LED can be inspected accurately.

In this case, the detection means may be provided with a light-shielding plate having a plurality of openings formed so that only the light from the LED facing the color sensor is incident on each color sensor. As a result, only the light from the LED facing the LED is incident on each color sensor, and the light from the other LEDs can be prevented from being incident on the color sensor. Therefore, each color sensor determines the illuminance of the LED facing the LED. It can be detected accurately.

As lighting pattern signals, only R color, G color only, B color only, RGB all colors, and RGB all are lit for a plurality of color sensors mounted on the LED mounting board. There are five types of signals that indicate each of the five types of non-lighting, and it is desirable that the control means determine that the LED mounting substrate has passed when the inspection results for the five types of lighting pattern signals are all good. .. In this way, the control means inspects the brightness and chromaticity of each LED for each of the above five types of lighting pattern signals, so that the pass / fail determination of the LED mounting substrate can be accurately performed.

Further, in the LED mounting substrate inspection device according to the present invention, the plurality of color sensors may be attached to the detection means so that each color sensor has a one-to-many correspondence with the plurality of LEDs on the LED mounting substrate. ..

Further, in the LED mounting board inspection device according to the present invention, the detection means may be a circuit board on which a plurality of color sensors are mounted. In this way, by using a circuit board on which a plurality of color sensors are mounted as the detection means, even when a plurality of LEDs are mounted on the LED mounting board at a high density, each color sensor is mounted on each LED on the LED mounting board. A detection means to which a plurality of color sensors are attached so as to have a one-to-one correspondence with the above can be easily manufactured.

Further, the LED mounting substrate inspection device according to the present invention is suitable for use when inspecting an LED mounting substrate used in a game machine.

In the LED-mounted substrate inspection device according to the present invention, the positions of the plurality of color sensors are determined according to the positional relationship of the plurality of LEDs on the LED-mounted substrate, and a plurality of color sensors are used during the inspection. The detection means arranged so as to face the LEDs at regular intervals, and the digital signal values of each RGB color output by each color sensor when a plurality of LEDs are lit according to a predetermined lighting pattern signal are captured and each of the captured digital signals. It is provided with a control means for inspecting each LED mounted on the LED mounting substrate based on the digital signal value of each RGB color of the color sensor and determining the pass / fail of the LED mounting substrate based on the inspection result. Therefore, the LED-mounted substrate inspection device according to the present invention is different from the conventional inspection device in which the light from each LED is imaged by the imaging means via the optical fiber or the entire LED-mounted substrate is imaged by the imaging means. Unlike this, it is not necessary to use an imaging means or a personal computer or the like for processing the image data captured by the imaging means, so that the LED can be inspected with a simple structure and at low cost.

FIG. 1 is a diagram for explaining an LED driving method on an LED mounting substrate. FIG. 2 is a schematic configuration diagram of an LED mounting substrate inspection device according to an embodiment of the present invention. FIG. 3 is a schematic block diagram of the inspection device for the LED mounting substrate. FIG. 4 is a diagram for explaining the configuration of a color sensor used in the inspection device for the LED mounting substrate. FIG. 5 is a flowchart for explaining a processing procedure when the inspection device for the LED mounting board of the present embodiment inspects one LED mounting board. FIG. 6 is a diagram for comparing and explaining the arrangement interval of a plurality of optical fibers in a conventional inspection device using an optical fiber and the mounting interval of a plurality of color sensors in the inspection device for the LED mounting substrate of the present invention. FIG. 7 is a diagram for explaining a detection unit to which a light-shielding plate is attached in the inspection device for the LED mounting substrate of the present invention.

Hereinafter, modes for carrying out the invention according to the present application will be described with reference to the drawings. FIG. 1 is a diagram for explaining an LED driving method on an LED mounting substrate. Further, FIG. 2 is a schematic configuration diagram of an LED-mounted substrate inspection device according to an embodiment of the present invention, FIG. 3 is a schematic block diagram of the LED-mounted substrate inspection device, and FIG. 4 is an LED-mounted substrate inspection device. It is a figure for demonstrating the structure of the color sensor used.

The LED-mounted substrate inspection device of the present embodiment inspects an LED-mounted substrate on which a plurality of LEDs are mounted. In general, any LED-mounted substrate incorporated in any electronic device can be inspected by the LED-mounted substrate inspection device of the present invention, but in the present embodiment, it is particularly used for a game machine. Consider the case of inspecting an LED mounting board.

In addition to the plurality of LEDs, many other electronic components are also mounted on the LED mounting substrate. In the following, detailed description of electronic components other than the LED mounted on the LED mounting board will be omitted. The number of LEDs mounted on the LED mounting substrate varies depending on the electronic device in which the LEDs are mounted. In fact, the LED-mounted substrate used in the game machine may be equipped with only one LED or 256 LEDs. In the present embodiment, as an example, a case where 16 LEDs are mounted on the LED mounting substrate 100 will be described as shown in FIGS. 1, 2 and 3. Further, the LED used in the present embodiment is capable of displaying RGB colors, and for example, an LTRB RASF manufactured by OSRAM Opto Semiconductors is used.

As shown in FIG. 1, there are a driver drive type and a direct drive type as the LED drive method in the LED mounting substrate 100. In the driver drive type, a driver circuit 110 for driving and controlling 16 LEDs is mounted on an LED mounting board 100, and the driver circuit 110 sends a drive signal to each LED based on an external control signal. It is a method to do. On the other hand, the direct drive type is a method in which a drive signal from the outside is directly sent to each LED. In the present embodiment, 16 LEDs mounted on the LED mounting substrate 100 are directly driven.

As shown in FIGS. 2 and 3, the LED mounting board inspection device of the present embodiment is mounted on the inspection start switch 10, the fixing base (fixing means) 20 for fixing the LED mounting board 100, and the LED mounting board 100. The detection unit (detection means) 30 that detects each color component of red (R) green (G) blue (B) as a digital signal for the light from each LED, and the light from each LED output from the detection unit 30. Inspection of the brightness and chromaticity of each LED based on the relay board 40 that relays the digital signal of each RGB color component of light and the digital signal of each RGB color component of light sent from each LED via the relay board 40. The control unit 50 that determines the pass / fail of the LED mounting board 100 based on the inspection result, and the result output unit that outputs the result of the inspection performed by the control unit 50 and the result of the pass / fail judgment of the LED mounting board 100 ( Output means) 60.

The inspection start switch 10 sends a signal to the control unit 50 to start the inspection when the switch operation is performed by the operator. The control unit 50 starts the inspection when it receives the signal from the inspection start switch 10.

The fixing base 20 is made of acrylic or the like. As shown in FIG. 2, the LED mounting substrate 100 is placed at a predetermined position of the fixing base 20, and is fixed to the fixing base 20 by using a predetermined jig (not shown). As this jig, for example, a belt, a rod, or the like may be used to prevent the LED mounting substrate 100 from rising. Further, when the LED mounting board 100 is fixed to the fixing base 20, 16 probes (not shown) come into contact with 16 terminals formed on the LED mounting board 100 for sending a drive signal to each LED. Will be. As shown in FIG. 3, the 16 signal lines connected to these probes are grouped into one cable 70 and connected to the control unit 50. As a result, the LED mounting board 100 and the control unit 50 are electrically connected.

As shown in FIGS. 2 and 3, the detection unit 30 includes 16 color sensors 31, a sensor fixing plate 32, and 16 connecting tools 33 for connecting each color sensor 31 and the sensor fixing plate 32. I have. The number of color sensors 31 provided in the detection unit 30 is the same as the number of LEDs mounted on the LED mounting substrate 100.

The color sensor 31 senses each RGB color component of the incident light and outputs it as a digital signal. In this embodiment, S11012-01CR manufactured by Hamamatsu Photonics is used as the color sensor 31. As shown in FIG. 4, the color sensor 31 includes a plurality of photodiodes 311a for detecting R color light, a plurality of photodiodes 311b for detecting G color light, a plurality of photodiodes 311c for detecting B color light, and R. It has a color digital signal conversion unit 312a, a G color digital signal conversion unit 312b, a B color digital signal conversion unit 312c, and a serial output circuit 313. Here, the photodiodes 311a, 311b, and 311c for each color sensing are arranged in a mosaic shape, and the light receiving portion is formed as a whole. The R color digital signal conversion unit 312a amplifies the signal measured by the plurality of photodiodes 311a and converts it into a 12-bit digital signal for R color. Similarly, the G color digital signal conversion unit 312b amplifies the signal measured by the plurality of photodiodes 311b and converts it into a 12-bit G color digital signal, and the B color digital signal conversion unit 312c , The signal measured by a plurality of photodiodes 311c is amplified and converted as a 12-bit B color digital signal. The serial output circuit 313 serially outputs digital signals of each color of RGB output from the three digital signal conversion units 312a, 312b, and 312c. Further, the color sensor 31 has a two-step sensitivity switching function of a high sensitivity mode and a low sensitivity mode. In the high-sensitivity mode, the entire light receiving portion of the color sensor 31 is used to detect the light, and in the low-sensitivity mode, a part of the light receiving portion of the color sensor 31 is used to detect the light. Specifically, it is desirable to select the high sensitivity mode when it is required to inspect the LED mounting substrate 100 with high accuracy, or when the inspection device is placed in a dark environment. By switching the sensitivity of the color sensor 31, it is possible to measure a wide range of illuminance.

As shown in FIG. 2, each color sensor 31 is fixed to the lower surface of the sensor fixing plate 32 via a rod-shaped connector 33. Here, the sensor fixing plate 32 and the connector 33 are made of, for example, acrylic. Further, the positions of the 16 color sensors 31 are determined according to the positional relationship of the 16 LEDs on the LED mounting substrate 100. In the present embodiment, the 16 color sensors 31 are attached to the sensor fixing plate 32 so that the positional relationship of these color sensors 31 is the same as the positional relationship of the 16 LEDs on the LED mounting substrate 100. That is, each color sensor 31 has a one-to-one correspondence with each LED on the LED mounting substrate 100. This is because one color sensor 31 detects the illuminance of the light from one LED. Specifically, when the detection unit 30 is manufactured, the fixing positions of the plurality of color sensors 31 on the sensor fixing plate 32 are determined based on the mounting data of the plurality of LEDs on the LED mounting substrate 100 to be inspected. ing.

Further, in the LED mounting substrate inspection device of the present embodiment, as shown in FIG. 2, the detection unit 30 is located above the fixed base 20, but the fixed base 20 is in the front-rear direction, the left-right direction, and up and down. It is configured to be movable in each direction. Specifically, at the time of inspection, the operator first operates a predetermined lever (not shown) to move the detection unit 30 in the front-rear direction and the left-right direction, and each color sensor 31 corresponds to the LED. The horizontal position of the detection unit 30 is determined so as to face the above. Next, by operating another lever (not shown), the detection unit 30 is moved in the vertical direction so that the distance between each color sensor 31 and the corresponding LED becomes a predetermined value. Determine the height position of. Here, the distance between each color sensor 31 and the corresponding LED is such that, for example, most of the light from the corresponding LED is incident on each color sensor 31, and almost no light from the other LED is incident on each color sensor 31. It is set as an interval. By arranging each color sensor 31 so as to face the corresponding LED at a predetermined interval in this way, each color sensor 31 can reliably receive the light from the corresponding LED.

In the present embodiment, the color sensor 31 is not directly fixed to the sensor fixing plate 32, but is fixed to the sensor fixing plate 32 via a rod-shaped connector 33. That is, the color sensor 31 and the sensor fixing plate 32 are separated from each other by a fixed interval in advance by using the connector 33. This is so that the color sensor 31 can be arranged sufficiently close to the LED even if the tall electronic component is mounted on the LED mounting substrate 100.

Although not shown in FIG. 2, the relay board 40 is attached to a predetermined position of the detection unit 30. As shown in FIG. 3, digital signals serially output from a plurality of color sensors 31 are input to the relay board 40. The relay board 40 includes 16 buffer circuits 41 that temporarily store digital signals from each color sensor 31 and correct the signal strength. Further, in FIG. 3, the relay board 40 is connected to the control unit 50 by 16 lines, but in reality, the 16 output signal lines drawn out from the relay board 40 are combined into one cable. It is connected to the control unit 50. The reason why the 16 output signal lines are combined into one cable is that if this is not done, the 16 output signal lines will interfere with the movement when the detection unit 30 is moved in the vertical direction or the like. This is to prevent the occurrence of such a situation because there is a possibility that the detection unit 30 or the like may come into contact with the wire and be cut off.

As shown in FIG. 3, the control unit 50 includes a microcomputer (control means) 51, two input buffer circuits 52a and 52b, one output buffer circuit 53, and an IC circuit 54.

The microcomputer 51 controls the lighting of 16 LEDs mounted on the LED mounting substrate 100, and the brightness of each LED is determined based on the digital signals of each RGB color sent from the color sensors 31 provided in the detection unit 30. It inspects the chromaticity. Specifically, the microcomputer 51 outputs 16 lighting pattern signals (drive signals) for lighting each LED in a predetermined lighting pattern to the output buffer circuit 53 for each of the 16 LEDs. LED lighting control is performed. In this embodiment, the same lighting pattern signal is transmitted to each LED. A cable 70 connected to 16 probes provided in the detection unit 30 is connected to the output buffer circuit 53. When the microcomputer 51 transmits the lighting pattern signal to the output buffer circuit 53 and then transmits the output control signal to the output buffer circuit 53, the output buffer circuit 53 outputs the lighting pattern signal. As a result, the lighting pattern signal is transmitted to the LED mounting substrate 100 via the cable 70 and 16 probes. In this way, the 16 LEDs mounted on the LED mounting substrate 100 are lit according to the lighting pattern signal.

Specifically, in this embodiment, five types of signals are used as lighting pattern signals. That is, the lighting pattern signal instructing to turn on the R color, the lighting pattern signal instructing to turn on the G color, the lighting pattern signal instructing to turn on the B color, and all the RGB colors are turned on. It is a lighting pattern signal instructing that, and a lighting pattern signal instructing not to light all RGB colors. The LED inspection is performed on each of these five types of lighting pattern signals.

Further, in the present embodiment, an 8-bit microcomputer 51 is used. Therefore, out of the digital signals of each color of RGB from the 16 color sensors 31, the digital signals of each color of RGB from the eight color sensors 31 are input to the input buffer circuit 52a, and the RGB from the remaining eight color sensors 31 The digital signals of each color are configured to be input to the input buffer circuit 52b. The microcomputer 51 sends an output control signal to each of the two input buffer circuits 52a and 52b at a predetermined timing, thereby transmitting a digital signal of each RGB color from each color sensor 31 sent to each of the input buffer circuits 52a and 52b. take in. The microcomputer 51 compares the digital signal of each RGB color of each of the captured color sensors 31 with a predetermined reference value as a gradation value of each color with respect to the lighting pattern signal of the LED corresponding to the color sensor 31. The brightness of each LED mounted on the LED mounting substrate 100 is inspected. Specifically, the microcomputer 51 obtains the difference between the digital signal value of each color component and the corresponding reference value, and when the difference is within a certain range, the color of the LED corresponding to the color sensor 31 is changed. It is determined that the brightness is OK, and if not, it is determined to be NG. The microcomputer 51 also inspects the chromaticity of each LED. Since the chromaticity of the LED can be known from the ratio of the digital signal values of each color, whether the chromaticity of the LED is OK or NG by checking whether the ratio is within the range of the predetermined reference ratio. Is determined. Finally, the microcomputer 51 determines the pass / fail of the LED mounting substrate 100 based on the LED inspection result. Specifically, the microcomputer 51 determines the brightness / chromaticity inspection results for all five types of lighting pattern signals for all the LEDs mounted on the LED mounting board 100 when the LED mounting board 100 is OK. Is judged to pass.

Since the color sensor 31 detects the illuminance of the light from the LED, to be precise, the microcomputer 51 inspects the illuminance of the light received from the LED by the color sensor 31. However, since the size of the light receiving surface of the color sensor 31 and the distance between the color sensor 31 and the LED are known in advance, the illuminance of the light received from the LED by the color sensor 31 is converted into the brightness of the LED by a predetermined relational expression. It is possible. For this reason and from the viewpoint of inspecting the LED, in the present embodiment, the microcomputer 51 expresses "inspecting the brightness of the LED" based on the digital signal of each RGB color from the color sensor.

The IC circuit 54 serves as an input interface for transmitting signals from the inspection start switch 10 to the microcomputer 51, and also serves as a peripheral control circuit for transmitting various signals from the microcomputer 51 to the result output unit 60. ..

As shown in FIG. 3, the result output unit 60 includes an inspection result display unit 61, an inspection pass number display unit 62, a stamp device 63, and an alarm device 64.

The inspection result display unit 61 displays the inspection result of the LED mounting substrate 100. For example, if the inspection result of the LED mounting substrate 100 is passed, the character "pass" is displayed on the inspection result display unit 61, and if it is not passed, the character "failed" is displayed. Further, in the LED-mounted substrate inspection device of the present embodiment, inspection is usually performed on a large number of LED-mounted substrates 100 of the same type, but the inspection pass number display unit 62 checks the LED-mounted substrate 100 of the same type. It displays the total number of LED-mounted substrates 100 that have passed the inspections performed so far. As the inspection pass number display unit 62, for example, a 7-segment LED display is used. A control signal for controlling the display is sent from the microcomputer 51 to the inspection result display unit 61 and the inspection pass number display unit 62 via the IC circuit 54, respectively. Further, the stamp device 63 is configured so that the stamp portion automatically moves, and the operation of the stamp portion is controlled based on the drive signal from the microcomputer 51. In the present embodiment, the stamp portion is engraved with the characters "pass". Therefore, the characters "pass" are stamped on the LED mounting substrate 100 determined to be pass by the stamp device 63. Here, the characters are imprinted on the unnecessary frame portion around the LED mounting substrate 100. Further, the alarm device 64 sounds an alarm for a certain period of time when the inspection result of the LED mounting substrate 100 is unacceptable. The operation of the alarm device 64 is also controlled based on the drive signal from the microcomputer 51 transmitted via the IC circuit 54.

Next, an inspection procedure using the inspection device for the LED mounting substrate of the present embodiment will be described. FIG. 5 is a flowchart for explaining a processing procedure when the inspection device for the LED mounting board of the present embodiment inspects one LED mounting board.

Now, consider a case where there are many LED-mounted substrates 100 of the same type and inspection of these LED-mounted substrates 100 is performed. Before starting the inspection, the operator first considers the accuracy required for this inspection, the environment in which the inspection device is placed, and the like, and sets the sensitivity of the color sensor 31 to the high sensitivity mode and the low sensitivity mode. Decide which of the modes to set. Then, the determined mode is set.

Further, the operator places the LED mounting substrate 100 to be inspected on the fixing base 20, and firmly fixes it to the fixing base 20 by using a predetermined fixture. At this time, each of the 16 probes connected to the signal line for transmitting the lighting pattern signal comes into contact with the LED driving terminal formed on the LED mounting substrate 100. Next, the operator performs the positioning work of the detection unit 30. Specifically, the operator moves the detection unit 30 in the front-rear direction and the left-right direction, and determines the horizontal position of the detection unit 30 so that each color sensor 31 faces the corresponding LED. After that, the detection unit 30 is moved in the vertical direction to determine the height position of the detection unit 30 so that the distance between each color sensor 31 and the corresponding LED becomes a predetermined value. In this way, each color sensor 31 provided in the detection unit 30 is arranged so as to face the corresponding LED at a predetermined interval.

When the preparatory work before the start of the inspection is completed, the operator presses the inspection start switch 10 to instruct the inspection device of the LED mounting substrate to start the inspection. As a result, a signal to start the inspection is sent to the microcomputer 51 via the IC circuit 54. When the microcomputer 51 receives the signal to start the inspection, the microcomputer 51 performs the process according to the flow of FIG.

First, the microcomputer 51 controls the lighting of 16 LEDs mounted on the LED mounting board 100 by transmitting a predetermined lighting pattern signal to the LED mounting board 100 (S11). Specifically, the microcomputer 51 sends a lighting pattern signal out of five types of lighting pattern signals to the output buffer circuit 53. After that, when the microcomputer 51 sends an output control signal to the output buffer circuit 53, the output buffer circuit 53 transmits the lighting pattern signal sent from the microcomputer 51 to the LED mounting board 100 via the cables 70 and 16 probes. .. As a result, the 16 LEDs mounted on the LED mounting substrate 100 are lit according to the transmitted lighting pattern signal (in the case of a lighting pattern signal instructing not to light all RGB colors, they are not lit). ..

When the 16 LEDs mounted on the LED mounting substrate 100 are turned on (or not turned on), the plurality of photodiodes 311a, 311b, and 311c in each color sensor 31 provided in the detection unit 30 are the color sensors, respectively. Among the light of each RGB color output by the LED facing the 31, the light of a predetermined color component is received. The signal obtained by the plurality of photodiodes 311a is converted into a 12-bit R color digital signal by the R color digital signal converter 312a, and the signal obtained by the plurality of photodiodes 311b is converted into a G color digital signal converter. It is converted into a 12-bit G-color digital signal by 312b, and the signal obtained by the plurality of photodiodes 311c is converted into a 12-bit B-color digital signal by the B-color digital signal converter 312c. The digital signals of each RGB color output from the three digital signal conversion units 312a, 312b, and 312c in this way are serially output via the serial output circuit 313.

The RGB digital signals of each color output from each color sensor 31 are sent to the control unit 50 via the relay board 40. Here, among the digital signals of each color of RGB from the 16 color sensors 31, the digital signals of each color of RGB from the eight color sensors 31 are input to the input buffer circuit 52a, and the RGB from the remaining eight color sensors 31 The digital signals of each color are input to the input buffer circuit 52b. The microcomputer 51 sends an output control signal to each of the two input buffer circuits 52a and 52b at a predetermined timing, thereby transmitting a digital signal of each RGB color from each color sensor 31 sent to each of the input buffer circuits 52a and 52b. Capture (S12).

Next, the microcomputer 51 inspects the brightness and chromaticity of the LED corresponding to the color sensor 31 based on the digital signals of each RGB color from one color sensor 31 (S13). Specifically, the microcomputer 51 first compares the digital signal value of each of the RGB colors with a predetermined reference value as a gradation value of each color with respect to the lighting pattern signal of the LED corresponding to the color sensor 31. Then, when the difference between the digital signal value and the corresponding reference value is within a certain range for all the color components of RGB, the microcomputer 51 determines that the brightness of the LED corresponding to the color sensor 31 is OK. It is determined that there is, and if not, it is determined that it is NG. Next, the microcomputer 51 compares the ratio of the digital signal values of the RGB colors with the ratio of a predetermined reference with respect to the lighting pattern signal of the LED corresponding to the color sensor 31. Then, the microcomputer 51 determines that the chromaticity of the LED corresponding to the color sensor 31 is OK when the ratio of the former is close to the ratio of the latter, and determines that it is NG when it is not. After that, the microcomputer 51 determines whether the inspection result is OK in any of the inspections of the brightness and the chromaticity of the LED corresponding to the color sensor 31 (S14). When the microcomputer 51 determines that the inspection result of either the brightness or the chromaticity of the LED is NG, the microcomputer 51 outputs a signal indicating "failure" to the inspection result display unit 61 via the IC circuit 54. At the same time, a drive signal for sounding an alarm is output to the alarm device 64 via the IC circuit 54 (S15). As a result, the character "failed" is displayed on the inspection result display unit 61, and the alarm device 64 issues an alarm for a certain period of time. When the operator recognizes the inspection result, the LED mounting board is removed from the fixing base 20 and treated as a defective board.

On the other hand, in step S14, when the microcomputer 51 determines that the inspection result is OK in any inspection of the brightness and chromaticity of the LED corresponding to the color sensor 31, the RGB colors from all the color sensors 31 are checked. It is determined whether or not the brightness and chromaticity of the LED have been inspected based on the digital signal (S16). If the judgment is negative, the microcomputer 51 proceeds to step S13 and inspects the brightness and chromaticity of the LED corresponding to the color sensor 31 based on the digital signals of each RGB color from another color sensor 31. I do.

If the inspection results of the brightness and chromaticity of the LED based on the digital signals of each RGB color from all the color sensors 31 are OK, the judgment in step S16 is affirmative. In this case, the microcomputer 51 turns on the LEDs for all the lighting pattern signals and determines whether or not the brightness and chromaticity of the LEDs have been inspected (S17). If the judgment is negative, the microcomputer 51 proceeds to step S11 and transmits another lighting pattern signal to the LED mounting board 100 to control the lighting of the 16 LEDs mounted on the LED mounting board 100. As a result, the brightness and chromaticity of the LED are inspected.

On the other hand, when the microcomputer 51 determines in step S17 that the LEDs have been turned on for all the lighting pattern signals and the brightness and chromaticity of the LEDs have been inspected, the LED mounting substrate 100 has no problem and passes. Recognize that. In this case, the microcomputer 51 outputs a signal indicating "pass" to the inspection result display unit 61 via the IC circuit 54, and displays the number of passing inspections so far including the current inspection result. Is output to the inspection pass number display unit 62 via the IC circuit 54 (S18). As a result, the characters "pass" are displayed on the inspection result display unit 61, and the total number of LED mounting substrates 100 that have been passed at the present time is displayed on the inspection pass number display unit 62. Further, the microcomputer 51 outputs a drive signal for driving the operation of the stamp portion of the stamp device 63 to the stamp device 63 via the IC circuit 54. As a result, the stamp portion operates, and the characters "pass" are stamped on the predetermined portion of the LED mounting substrate 100. After that, the operator removes the LED mounting board 100 from the fixing base 20. This completes the processing flow of FIG.

After that, when the operator fixes another LED mounting board 100 to the fixing base 20 and presses the inspection start switch 10, the processing flow according to FIG. 5 is restarted for the LED mounting board 100.

In the LED mounting substrate inspection device of the present embodiment, 16 color sensors are attached so that the positional relationship of the 16 color sensors is the same as the positional relationship of the 16 LEDs on the LED mounting substrate. When the detection unit, in which each color sensor is arranged so as to face the corresponding LED at regular intervals during inspection, and a plurality of LEDs mounted on the LED mounting substrate according to a predetermined lighting pattern signal are lit. The digital signal values of each RGB color output by each color sensor are captured, and the captured digital signal values of each RGB color of each color sensor are used as the gradation value of each color with respect to the lighting pattern signal of the LED corresponding to the color sensor. It is provided with a control unit that inspects the brightness and chromaticity of each LED by comparing with a predetermined reference value and determines the pass / fail of the LED mounting substrate based on the inspection result. Therefore, the LED-mounted substrate inspection device of the present embodiment is different from the conventional inspection device in which the light from each LED is imaged by the imaging means via the optical fiber or the entire LED-mounted substrate is imaged by the imaging means. Unlike this, it is not necessary to use an imaging means or a personal computer or the like for processing the image data captured by the imaging means, so that the brightness and chromaticity of the LED can be inspected with a simple structure and at low cost. ..

Further, in the LED mounting substrate inspection device of the present embodiment, 16 color sensors are attached to the detection unit so that each color sensor has a one-to-one correspondence with each LED on the LED mounting substrate. Since the illuminance of the light from one LED is detected by one color sensor, the LED can be inspected accurately.

Further, in the inspection device for the LED mounting substrate of the present embodiment, a color sensor that outputs a 12-bit digital signal for each RGB color of the incident light is used. As a result, the color sensor attached to the detection unit can output a digital signal value in 4096 steps for each of the RGB colors, so that the brightness and chromaticity of the LED can be inspected with high accuracy.

Further, in the inspection device for the LED-mounted substrate of the present embodiment, as the lighting pattern signal, only R color is lit, only G color is lit, and only B color is lit for a plurality of color sensors mounted on the LED mounted substrate. LEDs are used when five types of signals are used to indicate lighting, lighting of all RGB colors, and non-lighting of all RGB colors, and the control unit has good inspection results for these five lighting pattern signals. Judge the mounting board as acceptable. In this way, since the control unit inspects the brightness and chromaticity of each LED for each of the above five types of lighting pattern signals, it is possible to accurately determine the pass / fail of the LED mounting substrate.

The present invention is not limited to the above embodiment, and various modifications can be made within the scope of the gist thereof.

For example, in the above embodiment, as an example, a case of inspecting an LED mounting substrate on which 16 LEDs are mounted has been described, but of course, not only 16 LEDs but also one or a plurality of LEDs are mounted. It is possible to inspect the LED mounting substrate.

Further, in the above-described embodiment, a case where a detection unit in which each color sensor is fixed to the lower surface of the sensor fixing plate via a rod-shaped connector is used has been described. As the detection unit, a circuit board on which a plurality of color sensors are mounted may be used. As a result, even when a plurality of LEDs are mounted on the LED mounting board at a high density, the positional relationship of the plurality of color sensors is the same as the positional relationship of the plurality of LEDs on the LED mounting board. A detection unit to which a sensor is attached can be easily manufactured. This is an advantage of the LED-mounted substrate inspection device of the present invention over the conventional inspection device that captures the light from the LED via the optical fiber by the imaging means. Now, I will explain this point in detail.

FIG. 6 is a diagram for comparing and explaining the arrangement interval of a plurality of optical fibers in a conventional inspection device using an optical fiber and the mounting interval of a plurality of color sensors in the inspection device for the LED mounting substrate of the present invention. Generally, when the bending amount of an optical fiber exceeds a certain level, the light transmission characteristics deteriorate. As a countermeasure against this, in the conventional inspection device using an optical fiber, in order to keep the optical fiber in a straight state, a ride guide 220 is attached to the tip of the optical fiber 210 as shown in FIG. The guide 220 is press-fitted into a predetermined light guide fixing plate 230. At this time, the arrangement interval d of the optical fibers 210 is the sum of the thickness d1 of the light guide 220 and the processing dimension d2 of the press-fitting hole formed in the light guide fixing plate 230 (d = d1 + d2). Acrylic is usually used as the light guide fixing plate 230, but since acrylic is brittle, the processing dimension d2 cannot be made very narrow. Therefore, in the conventional inspection device using the optical fiber, there is a limitation that the arrangement interval d of the optical fiber 210 cannot be narrower than a certain fixed interval. Therefore, in the conventional inspection device using the optical fiber, it is not possible to inspect the LED mounting substrate in which a plurality of LEDs are mounted at a density narrower than the minimum arrangement interval of the optical fiber 210. On the other hand, in the LED-mounted substrate inspection device of the present invention, as shown in FIG. 6B, a circuit board 35 on which a plurality of color sensors 31 are mounted is fixed to a fixing plate 32a as a detection unit 30a. When used, the mounting interval D of the plurality of color sensors 31 can be made smaller than the shortest arrangement interval of the optical fiber 210. Therefore, it is possible to inspect an LED mounting substrate on which a plurality of LEDs are mounted at high density.

Further, in the above embodiment, a light-shielding plate having a plurality of openings formed may be attached to the detection unit so that only the light from the LED facing the color sensor is incident on each color sensor. FIG. 7 is a diagram for explaining a detection unit to which a light-shielding plate is attached in the inspection device for the LED mounting substrate of the present invention. The light-shielding plate 37 is arranged at a distance from the light-receiving surfaces of the plurality of color sensors 31 by a certain distance. Further, openings 38 are formed at each position of the light-shielding plate 37 corresponding to each color sensor 31. The size of the opening 38 is designed so that only the light from the LED facing the color sensor is incident on each color sensor. As a result, only the light from the LED facing the LED is incident on each color sensor, and the light from the other LEDs can be prevented from being incident on the color sensor. Therefore, each color sensor determines the illuminance of the LED facing the LED. It can be detected accurately.

Further, in the above embodiment, the case where each color sensor detects the illuminance of light from one LED has been described, but a plurality of LEDs are divided into a plurality of groups, and each color sensor belongs to a plurality of groups. The illuminance of the light from the LED may be detected collectively. That is, a plurality of color sensors may be attached to the detection unit so that each color sensor has a one-to-many correspondence with the plurality of LEDs on the LED mounting substrate. In this case, as the lighting pattern signal for lighting a plurality of LEDs belonging to one group at the same time, the five types of signals described in the above embodiment can be used. As a result, for example, when two LEDs are arranged in one group and one of the LEDs is not lit, the detected illuminance is the illuminance when the two LEDs are lit. It will be halved compared to that. Therefore, even with this method, it is possible to accurately determine the pass / fail of the LED mounting substrate. Further, as the lighting pattern signal, a plurality of signals that light a plurality of LEDs belonging to each group one by one may be used. Also by this method, it is possible to accurately determine the pass / fail of the LED mounting substrate as in the above embodiment.

Further, in the above embodiment, the case where the detection unit is arranged above the LED mounting board and the LED whose upper part shines is inspected has been described. However, in the inspection device for the LED mounting board of the present invention, the LED whose side shines is also inspected. It is possible.

Further, in the above embodiment, the case of inspecting the LED mounting substrate used in the game machine by using the LED mounting substrate inspection device of the present invention has been described, but in general, it is incorporated in any electronic device. It is possible to inspect the LED-mounted substrate of the present invention with the inspection device of the LED-mounted substrate of the present invention.

As described above, in the LED mounting substrate inspection device according to the present invention, the positions of the plurality of color sensors are determined according to the positional relationship of the plurality of LEDs on the LED mounting substrate, and a plurality of color sensors are determined at the time of inspection. The detection means in which the color sensors of the above are arranged so as to face the plurality of LEDs at regular intervals, and the digital signal value of each RGB color output by each color sensor when the plurality of LEDs are lit according to a predetermined lighting pattern signal. A control means that inspects each LED mounted on the LED mounting board based on the digital signal value of each RGB color of the captured color sensor and determines the pass / fail of the LED mounting board based on the inspection result. I have. Therefore, the LED-mounted substrate inspection device according to the present invention is different from the conventional inspection device in which the light from each LED is imaged by the imaging means via the optical fiber or the entire LED-mounted substrate is imaged by the imaging means. Unlike this, it is not necessary to use an imaging means or a personal computer or the like for processing the image data captured by the imaging means, so that the LED can be inspected with a simple structure and at low cost. Therefore, the present invention is suitable for use when inspecting an LED mounting substrate provided in an electronic device such as a game machine.

10 Inspection start switch 20 Fixing base (fixing means)
30, 30a Detection unit (detection means)
31 Color sensor 311a R color sensing photodiode 311b G color sensing photodiode 311c B color sensing photodiode 312a R color digital signal conversion unit 312b G color digital signal conversion unit 312c B color digital signal conversion unit 313 Serial Output circuit 32, 32a Sensor fixing plate 33 Connector 35 Circuit board 37 Shading plate 38 Opening 40 Relay board 41 Buffer circuit 50 Control unit 51 Microcomputer (control means)
52a, 52b Input buffer circuit 53 Output buffer circuit 54 IC circuit 60 Result output unit (output means)
61 Inspection result display unit 62 Inspection pass number display unit 63 Stamp device 64 Alarm device 70 Cable 100 LED mounting board 110 Driver circuit 210 Optical fiber 220 Ride guide 230 Light guide fixing plate

Claims (7)

An LED-mounted board inspection device that inspects LED-mounted boards that mount multiple LEDs.
A fixing means for fixing the LED mounting board and
It has a plurality of color sensors that detect each RGB color component of incident light and output it as a digital signal, and the positions of the plurality of color sensors are determined according to the positional relationship of the plurality of LEDs on the LED mounting substrate. The detection means, in which the plurality of color sensors are arranged so as to face the plurality of LEDs at regular intervals during inspection.
When a lighting pattern signal for lighting each LED in a predetermined lighting pattern is transmitted to the plurality of LEDs mounted on the LED mounting substrate at the time of inspection, and the plurality of LEDs are lit according to the lighting pattern signal. The digital signal values of each RGB color output by each of the color sensors are taken in, and each of the LEDs mounted on the LED mounting substrate is inspected based on the captured digital signal values of each of the RGB colors of each color sensor. A control means for determining the pass / fail of the LED mounting substrate based on the inspection result,
An output means for outputting the determination result of the LED mounting board sent from the control means, and
An inspection device for an LED-mounted substrate. The plurality of color sensors are attached to the detection means so that each color sensor has a one-to-one correspondence with each LED on the LED mounting substrate.
The control means captures the digital signal values of the RGB colors output by the color sensors when the plurality of LEDs are lit according to the lighting pattern signal, and captures the captured digital signal values of the RGB colors of the color sensors. By comparing with a predetermined reference value as a gradation value of each color for the lighting pattern signal of the LED corresponding to the color sensor, the brightness and / or color of each LED mounted on the LED mounting substrate. The LED mounting substrate inspection device according to claim 1, wherein the inspection is performed. The inspection according to claim 2, wherein the detection means is provided with a light-shielding plate having a plurality of openings formed so that only light from an LED facing the color sensor is incident on the color sensor. apparatus. The lighting pattern signals include lighting of only R color, lighting of only G color, lighting of only B color, lighting of all RGB colors, and all of RGB for the plurality of color sensors mounted on the LED mounting substrate. There are five types of signals instructing each of the non-lighting of the colors of, and the control means determines that the LED mounting substrate has passed when the inspection results for the five types of lighting pattern signals are all good. The inspection device according to claim 2 or 3, wherein the inspection apparatus is used. The LED mounting substrate according to claim 1, wherein the plurality of color sensors are attached to the detection means so that each color sensor has a one-to-many correspondence with a plurality of LEDs on the LED mounting substrate. Inspection equipment. The inspection device according to claim 1, 2, 3, 4 or 5, wherein the detection means is a circuit board on which the plurality of color sensors are mounted. The inspection device according to claim 1, 2, 3, 4, 5 or 6, wherein the LED-mounted substrate to be inspected is used for a game machine.

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