A board transport positioning system and automated optical inspection apparatus

Abstract

The application provides a board conveying positioning system and an automatic optical detection device, four groups of photoelectric sensors, namely, an entering board opening sensor, a decelerating sensor, a stopping board sensor and an exiting board opening sensor, are arranged in sequence along a conveying direction of the board, a complete board position sensing and conveying speed control system is established, and the board is stopped in a non-contact manner, physical collision and scratching caused by mechanical blocking of the board are fundamentally avoided, the board is ensured to be undamaged, and the technical problem that the traditional physical blocking of the board is extremely easy to cause damage to the board is solved.

Description

Technical Field

[0001] This utility model relates to the field of automation control, and in particular to a board transmission and positioning system and an automated optical inspection device. Background Technology

[0002] Currently, the mainstream board positioning method in AOI (Automated Optical Inspection) systems generally relies on mechanical stop mechanisms. The workflow typically involves a physical stop arm being raised by a cylinder or motor when the conveyor belt transports the board to the inspection station, thus blocking the board's forward movement and achieving rigid positioning. This method is highly dependent on the machining accuracy and installation position of the stop arm itself to determine the board's position, and its positioning accuracy has theoretically reached the physical limit (typically ±1.5mm).

[0003] However, the traditional mechanical stop method, by its very nature of physical obstruction, means that the stop arm will directly collide and rub against the edge of the high-speed moving circuit board, which can easily cause scratches, indentations, and other mechanical damage to high-value or precision circuit boards. Secondly, its accuracy is no longer sufficient to meet the testing requirements of higher-precision components, and the accuracy will further decrease due to mechanical wear. Utility Model Content

[0004] This application provides a board transmission and positioning system and an automated optical inspection device. This application can realize contactless board stopping, which solves the technical problem that traditional physical blocking of boards can easily damage the boards.

[0005] In a first aspect, this application provides a board transmission and positioning system, comprising: A rack is used to provide structural support and mounting reference for the various components of a system. A transmission mechanism, mounted on the rack, is used to transport circuit boards; Multiple sets of photoelectric sensors include an inlet sensor for detecting the board entering, a deceleration sensor for triggering the transmission mechanism to decelerate when the board is detected, a stop sensor for triggering the transmission mechanism to stop when the board is detected, and an outlet sensor for detecting the board leaving. The inlet sensor, the deceleration sensor, the stop sensor, and the outlet sensor are sequentially fixed on the frame along the transmission direction of the transmission mechanism.

[0006] As described above, this application provides a board transmission and positioning system. By setting four sets of photoelectric sensors—an inlet sensor, a deceleration sensor, a stop sensor, and an outlet sensor—arranged sequentially along the transmission direction of the board, a complete board position perception and transportation speed control system is established. This system enables contactless board stopping, fundamentally avoiding physical collisions and scratches caused by using mechanical blocks to obstruct the board, ensuring the board remains undamaged, and solving the technical problem that traditional physical methods of obstructing the board are prone to causing damage.

[0007] The photoelectric sensor includes a through-beam photoelectric sensor; each group of photoelectric sensors includes a pair of through-beam photoelectric sensors; each pair of through-beam photoelectric sensors includes a transmitter and a receiver arranged opposite to each other.

[0008] As described above, this application uses through-beam photoelectric sensors, and each group of through-beam photoelectric sensors includes a transmitter and a receiver arranged opposite to each other. By using the detection method of blocking light, it can accurately identify whether the board has reached the corresponding detection position. It has strong anti-ambient light interference capability and high detection stability. At the same time, the independent transmitter and receiver design can ensure accurate perception of the board edge and its status, effectively improving the positioning accuracy during the board transmission process.

[0009] The photoelectric sensor is a through-beam fiber optic sensor. At least one of the multiple sets of through-beam fiber optic sensors has its transmitting and receiving ends positioned opposite each other on a plane perpendicular to the plane where the board is located. A signal is triggered by a change in light flux caused by the thickness of the board obstructing the light path as it passes by; or... At least one of the multiple sets of through-beam fiber optic sensors has its transmitter and receiver positioned on opposite sides of the plane where the board is located, so that when the board passes by, it completely blocks the optical path trigger signal between the transmitter and the receiver.

[0010] As described above, this application provides a simple, low-cost, and reliable detection scheme by installing at least one set of through-beam fiber optic sensors with the transmitter and receiver facing each other and triggering the detection by blocking the light through the thickness of the board. This scheme is particularly suitable for detecting boards with uniform thickness and can effectively balance cost and performance in specific application scenarios. Alternatively, by installing at least one set of through-beam fiber optic sensors with the transmitter and receiver misaligned and triggering the detection by completely blocking the light path, this scheme avoids missed detections that may occur due to gaps at the front end of the board.

[0011] The photoelectric sensor is a through-beam fiber optic sensor; at least one of the multiple through-beam fiber optic sensors has its transmitting end and receiving end arranged on opposite sides of the plane where the board is located, so that when the board passes by, it completely blocks the optical path trigger signal between the transmitting end and the receiving end, and at least one end of the transmitting end and the receiving end is mounted on the rack through an angle adjustment device.

[0012] As described above, this application can calibrate the optical path of the through-beam fiber optic sensor by adding an angle adjustment device. When the optical path is deviated due to the widening track, mechanical vibration or long-term use, the optical path can be quickly calibrated by fine-tuning the angle, thereby ensuring the accuracy of detection.

[0013] The angle adjustment device includes: A mounting bracket installed on the frame; The mounting block is rotatably mounted on the fixed base and is used to mount the transmitter or receiver. An angle adjustment mechanism, connected to the fixed base and the mounting block, is used to drive the mounting block to rotate around a rotation center to adjust the angle of the mounting block; A locking mechanism is used to fix the transmitter or the receiver to the mounting block; An elastic reset element is used to provide an elastic force to reset the mounting block to its initial position.

[0014] As described above, this application provides a simple, low-cost, and reliable mechanical optical path calibration scheme that can effectively compensate for optical path offset caused by track width adjustment, mechanical deformation, or installation tolerances, and significantly improve the stability and adaptability of sensor detection.

[0015] The mounting block is provided with an optical fiber jack, which is used to insert the transmitting end or the receiving end of the through-beam optical fiber sensor. The angle adjustment mechanism is an angle adjustment component connected to the fixed base and the mounting block. By screwing it in or out, its protrusion depth is changed to push the mounting block to rotate. The locking mechanism is an optical fiber fastener connected to the mounting block, used to lock the transmitter or receiver inserted into the optical fiber jack. The elastic reset element is a return spring disposed between the fixed base and the mounting block.

[0016] As described above, this application achieves high-precision and high-stability calibration and maintenance of the optical path through the combination of mounting blocks, angle adjustment components, fiber optic fixing components, and return springs.

[0017] This also includes: A friction module is disposed downstream of and adjacent to the deceleration sensor, and is used to apply a preset friction force to the surface of the board when the transmission mechanism decelerates.

[0018] As described above, this application adds a friction module to the board transmission and positioning system. The friction module provides a controllable auxiliary braking force during the board deceleration process, which effectively consumes the kinetic energy inertia of the board, suppresses the overshoot phenomenon of the board, and improves the stopping accuracy.

[0019] This also includes: A clamping mechanism is disposed on the side of the transmission mechanism corresponding to the detection position of the stop sensor, and is used to clamp and fix the board after the board stops; A width adjustment mechanism, connected to the transmission mechanism, is used to adjust the width of the transmission mechanism to accommodate boards of different sizes; A closed-loop width-adjusting motor is driven and connected to the width-adjusting mechanism to control the width-adjusting mechanism to adjust the width.

[0020] As described above, this application, by setting up a clamping mechanism, can provide stable clamping force from both sides of the board after it has come to a stop, completely eliminating any possible slight shaking or slippage of the board, and providing a stable reference platform for subsequent automated optical inspection, thereby ensuring inspection accuracy; and by setting up a width adjustment mechanism and a closed-loop width adjustment motor, the width of the transmission mechanism can be adjusted to adapt to boards of different sizes, avoiding the cumbersome process of changing tooling fixtures.

[0021] This also includes: The fine-tuning compensation module is used to control the transmission mechanism to move in the opposite direction of the transmission direction when the stop sensor is triggered and the overshoot of the board is detected, so as to compensate for the overshoot distance of the board.

[0022] As described above, by setting a fine-tuning compensation module, when the board overshoot is detected after the stop sensor is triggered, the transmission mechanism can be automatically controlled to move in the opposite direction to compensate for the overshoot distance. This effectively corrects the positioning deviation of the board caused by factors such as inertia, ensuring that the board accurately stops at the preset position and avoiding the impact of overshoot on the accuracy of subsequent detection, processing and other operations.

[0023] Secondly, this application provides an automated optical inspection device, including an automated optical inspection module for performing automated optical inspection on circuit boards and the circuit board transmission and positioning system described in the first aspect. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of a board transmission and positioning system provided in an embodiment of the present utility model.

[0025] Figure 2 This is one of the schematic diagrams illustrating the configuration of a through-beam fiber optic sensor according to an embodiment of the present invention.

[0026] Figure 3 This is a second schematic diagram illustrating the configuration of a through-beam fiber optic sensor according to an embodiment of the present invention.

[0027] Figure 4This is the third schematic diagram of a through-beam fiber optic sensor configuration provided in this embodiment of the present invention.

[0028] Figure 5 An exploded view of an angle adjustment device provided in an embodiment of this utility model.

[0029] Figure 6 This is a schematic flowchart of a board feeding process provided for an embodiment of the present utility model.

[0030] Figure 7 This is a schematic diagram illustrating how a board moves from the board inlet to the position corresponding to the stop sensor, as provided in an embodiment of this utility model.

[0031] Figure 8 This is a schematic diagram of a board ejection process provided for an embodiment of the present utility model.

[0032] Figure 9 This is a schematic diagram illustrating how a board moves from a stop position to the position corresponding to the outlet sensor, as provided in an embodiment of this utility model.

[0033] Reference numerals: 1. Frame; 2. Transmission mechanism; 31. Inlet sensor; 32. Deceleration sensor; 33. Stop sensor; 34. Outlet sensor; 4. Board; 5. Transmitter T; 6. Receiver R; 7. Angle adjustment device; 8. Fixing base; 9. Mounting block; 10. Angle adjustment mechanism; 11. Locking mechanism; 12. Elastic reset element; 13. Fiber optic jack; 14. Fiber optic socket. Detailed Implementation

[0034] The following description and accompanying drawings fully illustrate specific embodiments of this application to enable those skilled in the art to practice them. The embodiments represent only possible variations. Individual components and functions are optional unless explicitly required, and the order of operations may vary. Parts and features of some embodiments may be included in or replace parts and features of other embodiments. The scope of embodiments of this application includes the entire scope of the claims and all available equivalents of the claims. In this document, each embodiment may be referred to individually or collectively by the term "utility model," which is merely for convenience and, if more than one utility model is disclosed, is not intended to automatically limit the scope of the application to any single utility model or utility model concept. Relational terms such as "first" and "second" are used herein only to distinguish one entity or operation from another, without requiring or implying any actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed. The various embodiments in this document are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the structures, products, etc., disclosed in the embodiments, since they correspond to the disclosed parts, the descriptions are relatively simple; relevant details can be found in the method section.

[0035] Currently, the mainstream stopping and positioning methods in automated optical inspection systems generally rely on mechanical stop mechanisms. The workflow typically involves a cylinder or motor driving a physical stop arm to rise when the conveyor belt transports the board to the inspection station. This rigid physical stop arm forcibly blocks the moving board, bringing it to a stop and achieving rigid positioning. This method is highly dependent on the machining accuracy and installation position of the stop arm to determine the stopping position, and its positioning accuracy has theoretically reached the physical limit (typically ±1.5mm).

[0036] However, the traditional mechanical stop method, by its very nature of physical obstruction, means that the stop arm will directly collide and rub against the edge of the high-speed moving circuit board, easily causing scratches, cracks, or hidden damage to high-value or precision circuit boards. Furthermore, its accuracy depends entirely on the machining and installation precision of the mechanical stop itself; the ±1.5mm limit is difficult to improve, failing to meet the testing requirements of high-precision components, and accuracy will further decrease due to mechanical wear. Simultaneously, traditional mechanical stops cannot intelligently adapt to different board weights and materials, requiring manual stop replacement, which is inefficient. For irregularly shaped circuit boards with protruding connectors or grooves, not only is effective positioning impossible, but there is also a risk of scratching and damaging critical parts such as gold fingers. In conclusion, the traditional method of stopping circuit boards using mechanical stops severely restricts the requirements of modern electronic manufacturing for precision, efficiency, and flexible production.

[0037] Based on this, in order to solve the above-mentioned technical problems, this utility model provides a board transmission and positioning system. This utility model establishes a complete board position perception and transportation speed control system to realize contactless board stopping, fundamentally avoiding physical collisions and scratches caused by using mechanical blocks to block the board, ensuring that the board is undamaged, and solving the technical problem that traditional physical blocking of boards is very likely to damage the board.

[0038] like Figure 1 As shown, Figure 1 This is a schematic diagram of a board transmission and positioning system provided in an embodiment of the present invention. The board transmission and positioning system provided in this embodiment of the present invention includes: Frame 1 is used to provide structural support and mounting reference for the various components of the system.

[0039] The transmission mechanism 2, mounted on the frame 1, is used to transport the board 4.

[0040] Multiple sets of photoelectric sensors, including an inlet sensor 31 for detecting the entry of board 4, a deceleration sensor 32 for triggering the deceleration of the transmission mechanism 2 when board 4 is detected, a stop sensor 33 for triggering the stop of the transmission mechanism 2 when board 4 is detected, and an outlet sensor 34 for detecting the exit of board 4, are sequentially fixed on the frame 1 along the transmission direction of the transmission mechanism 2.

[0041] In this embodiment, the board transmission and positioning system includes a frame 1, a transmission mechanism 2, and multiple sets of photoelectric sensors. The frame 1 provides a rigid support foundation for the board transmission and positioning system and can be constructed using aluminum alloy profiles connected by angle brackets. The transmission mechanism 2 is used to transport the board 4. For example, the transmission mechanism 2 can be a mechanism that drives or propels the board 4 to move in a specific direction via a belt, chain, or roller. For example, taking a belt transmission mechanism as an example, the belt transmission mechanism includes an open-loop stepper motor, a synchronous pulley, and a belt. The open-loop stepper motor receives pulse signals from the board transmission and positioning system and drives the synchronous pulley to rotate according to the pulse signals. The synchronous pulley drives the belt to move linearly through friction. In addition, four sets of photoelectric sensors are installed on the frame 1. The working principle of the photoelectric sensors is based on the photoelectric effect, which refers to the phenomenon where electrons in a substance absorb the energy of photons and produce corresponding electrical effects when light shines on them. In this embodiment, the position of the board is detected by the photoelectric sensors through changes in the light signal. Photoelectric sensors can be types such as photoelectric switches, laser sensors, or infrared sensors. A photoelectric switch is triggered when an object enters its detection range, blocking or reflecting light, causing a change in the intensity of the light signal received by the receiver. A trigger signal is generated when the light signal intensity falls below a preset light intensity threshold. A laser sensor is triggered when an object blocks, reflects, or diffusely reflects the laser beam emitted by the transmitter, altering the laser energy received by the receiver. A trigger signal is generated when the change in laser energy exceeds a set threshold. An infrared sensor is triggered when an object enters the detection area, blocking or reflecting the infrared beam, causing a change in the intensity of the infrared signal received by the receiver. A trigger signal is generated when the infrared signal intensity falls below a preset infrared signal intensity threshold.

[0042] In this embodiment, the four sets of photoelectric sensors are an inlet sensor 31, a deceleration sensor 32, a stop sensor 33, and an outlet sensor 34. These four sets of photoelectric sensors are installed at intervals along the transmission direction of the transmission mechanism 2. Each set of photoelectric sensors can be set at equal or unequal intervals, depending on the detection requirements; no specific limitation is made in this embodiment. In this embodiment, when the board 4 passes through the area detected by the photoelectric sensor, the light signal detected by the photoelectric sensor changes, triggering the photoelectric sensor to output a corresponding signal. The board transmission positioning system can determine that the board 4 has reached the corresponding position based on the signal output by the photoelectric sensor to trigger the corresponding action.

[0043] For example, taking the transmission mechanism 2 as an example, the inlet sensor 31, as the starting point of the detection process, is installed at the inlet of the board 4 in the transmission mechanism 2. When the inlet sensor 31 is triggered, the board transmission positioning system determines that board 4 has entered. At this time, a preset high-speed pulse signal needs to be sent to the open-loop stepper motor of the transmission mechanism 2 to make the belt run at high speed. The deceleration sensor 32 is located a certain distance downstream of the inlet sensor 31. When the deceleration sensor 32 is triggered, it indicates that board 4 has entered the deceleration positioning area. The board transmission positioning system needs to send a preset low-speed pulse signal to the open-loop stepper motor of the transmission mechanism 2 to smoothly switch the belt transmission speed from high speed to low speed, thereby reducing the transmission speed of board 4. The stop sensor 33 is set at a preset stop point. When the stop sensor 33 is triggered, the board transmission positioning system needs to send a stop signal to the open-loop stepper motor to stop the operation immediately, so that board 4 stops at the stop point. The board exit sensor 34 is installed at the exit of the transmission mechanism 2 to detect whether the board 4 has completely left the transmission area. When the board 4 blocks the optical path of the board exit sensor 34, the board exit sensor 34 outputs a low-level signal as a departure signal of the board 4; or when the tail of the board 4 leaves the light curtain of the board exit sensor 34 and the optical path of the board exit sensor 34 is restored, the receiving end R of the board exit sensor 34 outputs a reset level, which serves as the departure signal of the board 4. After the board is ejected, multiple sets of photoelectric sensors and the transmission mechanism 2 are reset to prepare for receiving the next board.

[0044] The above-described embodiment of the present invention provides a board transmission and positioning system. By setting four sets of photoelectric sensors—an inlet sensor, a deceleration sensor, a stop sensor, and an outlet sensor—arranged sequentially along the transmission direction of the board, a complete board position perception and transportation speed control system is established. This system enables contactless board stopping, fundamentally avoiding physical collisions and scratches caused by using mechanical blocks to obstruct the board, ensuring the board remains undamaged, and solving the technical problem that traditional methods of physically obstructing the board are prone to causing damage.

[0045] Based on the above embodiments, the photoelectric sensor includes a through-beam photoelectric sensor; each group of photoelectric sensors includes a pair of through-beam photoelectric sensors; each pair of through-beam photoelectric sensors includes a transmitter and a receiver arranged opposite to each other.

[0046] In this embodiment, the photoelectric sensor includes a through-beam photoelectric sensor. A through-beam fiber optic sensor is a sensor that detects objects by changing the optical path. Its core components include a transmitter and a spatially separated receiver. Each group of photoelectric sensors includes a transmitter T and a receiver R positioned opposite each other. The transmitter T emits a modulated light signal, and the receiver R receives the light signal. When the board 4 blocks the optical path between the transmitter T and receiver R of the same group of photoelectric sensors, the light flux decreases sharply, and the output level of the receiver R changes from high to low. This allows the board's positioning system to determine that the board 4 has reached the corresponding position based on the level signal output by the receiver R of the photoelectric sensor, thus triggering the corresponding action.

[0047] The above-mentioned method uses through-beam photoelectric sensors, with each group of through-beam photoelectric sensors including a transmitter and a receiver arranged opposite each other. By using a light-blocking detection method, it can accurately identify whether the board has reached the corresponding detection position. It has strong resistance to ambient light interference and high detection stability. At the same time, the independent transmitter and receiver design can ensure accurate perception of the board's edge and its status, effectively improving the positioning accuracy during the board's transmission process.

[0048] Based on the above embodiments, the photoelectric sensor is a through-beam fiber optic sensor; At least one of multiple sets of through-beam fiber optic sensors has its transmitter T and receiver R positioned directly opposite each other on a plane perpendicular to the board 4. A signal is triggered by a change in light flux caused by the thickness of the board 4 obstructing the light path as it passes by; or... At least one of the multiple sets of through-beam fiber optic sensors has its transmitter T and receiver R positioned on opposite sides of the plane of the board 4, so that when the board 4 passes by, it completely blocks the optical path trigger signal between the transmitter T and the receiver R.

[0049] In this embodiment, the transmitting end T and receiving end R of at least one set of through-beam fiber optic sensors are positioned opposite each other on a plane perpendicular to the plane where board 4 is located, both located above the belt, such as... Figure 2 As shown, Figure 2 This is one schematic diagram illustrating the setup of a through-beam fiber optic sensor according to an embodiment of this utility model. Its working principle is based on the thickness of the board 4 itself blocking the vertical optical path. The luminous flux monitored by the receiver R will decrease from 100% to 0%. By setting an appropriate luminous flux threshold (greater than 0%), a trigger signal is output when the luminous flux monitored by the receiver R falls below the threshold. This setup is suitable for detecting boards with uniform thickness and no gaps, and will not cause missed detections due to insufficient thickness.

[0050] The above-described method of mounting at least one set of through-beam fiber optic sensors with their transmitters and receivers facing each other, and triggering the detection by shielding the light through the thickness of the board, provides a simple, low-cost, and reliable detection solution. It is particularly suitable for detecting boards with uniform thickness and can effectively balance cost and performance in specific application scenarios.

[0051] However, during implementation, it was found that when there is a notch at the front end of board 4, and the notch is exactly on the vertical optical path, it will cause a brief period of optical path conduction. Therefore, setting the transmitter T and receiver R of the through-beam fiber optic sensor directly opposite each other may lead to false detection. Based on this, in another embodiment, the transmitter T and receiver R of at least one set of through-beam fiber optic sensors can be offset by a certain distance on both sides of the plane where board 4 is located. For example, Figure 3 As shown, Figure 3 This is a second schematic diagram illustrating the arrangement of a through-beam fiber optic sensor according to an embodiment of this utility model. Its working principle is that even if the notch on board 4 is directly opposite the transmitter T, the main body of board 4 will still cover the misaligned area, completely blocking the optical path. This causes the light flux detected by the receiver R to drop from 100% to 0%. The misaligned arrangement prevents the small notch on board 4 from penetrating the optical path, thus avoiding false detection.

[0052] As described above, this utility model embodiment avoids missed detections that may occur due to gaps at the front end of the board by setting the transmitter and receiver of at least one set of through-beam fiber optic sensors on opposite sides of the plane where the board is located, thereby completely blocking the light path trigger.

[0053] Based on the above embodiments, the photoelectric sensor is a through-beam fiber optic sensor; at least one of the multiple through-beam fiber optic sensors has its transmitting end T and receiving end R arranged on opposite sides of the plane where the board 4 is located, so that the optical path trigger signal between the transmitting end T and the receiving end R is completely blocked when the board 4 passes by, and at least one end of the transmitting end T and the receiving end R is mounted on the frame 1 through the angle adjustment device 5.

[0054] In another embodiment, based on the misaligned installation of the transmitter T and receiver R of the through-beam fiber optic sensor, at least one of the transmitter T and receiver R can be mounted on the frame 1 via an angle adjustment device 5. The angle adjustment device 5 can adjust the optical path of the through-beam fiber optic sensor, thereby allowing for recalibration of the optical path when misalignment occurs due to mechanical tolerances. Figure 4 As shown, Figure 4This is a third schematic diagram illustrating the configuration of a through-beam fiber optic sensor according to an embodiment of the present invention. Exemplarily, the angle adjustment device 5 is a rotatable bracket connected to the frame 1 via a rotating shaft. An adjustment knob is provided on the bracket, and the receiver R is mounted on the rotatable bracket. When the optical path of the receiver R deviates from that of the transmitter T, rotating the adjustment knob causes the rotatable bracket to rotate around the rotating shaft, realigning the receiver R with the transmitter T, thus achieving optical path calibration. The angle adjustment device 5 can be applied to scenarios requiring frequent adjustments to the track width, and by calibrating the optical path, it can quickly adapt to boards of different widths.

[0055] As described above, this utility model embodiment can calibrate the optical path of the through-beam fiber optic sensor by adding an angle adjustment device. When the optical path is deviated due to the widening track, mechanical vibration, or long-term use, the optical path can be quickly calibrated by fine-tuning the angle, thereby ensuring the accuracy of detection.

[0056] Based on the above embodiments, the angle adjustment device 5 includes: Mounting bracket 51 mounted on frame 1.

[0057] Mounting block 52 is rotatably mounted on fixed base 51 for mounting transmitter T or receiver R; Angle adjustment mechanism 53 is connected to fixed base 51 and mounting block 52, and is used to drive mounting block 52 to rotate around a rotation center to adjust the angle of mounting block 52.

[0058] The locking mechanism 54 is used to fix the transmitter T or receiver R to the mounting block 52.

[0059] The elastic reset element 55 is used to provide an elastic force to reset the mounting block 52 to its initial position.

[0060] In this embodiment, the transmitter T or receiver R of the through-beam fiber optic sensor can be fixed to the mounting block 52 by the locking mechanism 54. When the optical path needs to be adjusted, the user can operate the angle adjustment mechanism 53, which drives the mounting block 52 to rotate around its rotation center. The rotation of the mounting block 52 changes the angle of the receiver R or transmitter T fixed thereon. By observing the light flux of the receiver R, the operator can adjust the optical path to the optimal alignment state. Throughout the adjustment process, the elastic reset element 55 always provides a stable reset torque. This torque is used to eliminate mechanical backlash in the adjustment mechanism and, when the angle adjustment mechanism 53 is released, it helps the mounting block 52 return to its initial position, facilitating recalibration. The above-described embodiments of the present invention provide a simple, low-cost, and reliable mechanical optical path calibration scheme that can effectively compensate for optical path offset caused by track width adjustment, mechanical deformation, or installation tolerances, and significantly improve the stability and adaptability of sensor detection.

[0061] In one embodiment, such as Figure 5 As shown, Figure 5 This is an exploded view of an angle adjustment device 5 provided in an embodiment of the present invention. Figure 5 In the mounting block 52, there is an optical fiber jack 56 for inserting the transmitter T or receiver R of the through-beam optical fiber sensor; the angle adjustment mechanism 53 is an angle adjustment component connected to the fixing base 51 and the mounting block 52, which can be screwed in or out to change its protrusion depth to push the mounting block 52 to rotate; the locking mechanism 54 is an optical fiber fixing component connected to the mounting block 52, which is used to lock the transmitter T or receiver R inserted into the optical fiber jack 56; the elastic reset element 55 is a return spring disposed between the fixing base 51 and the mounting block 52.

[0062] In one embodiment, the angle adjustment component and the fiber optic fixing component are respectively an angle adjustment screw and a fiber optic fixing screw. By screwing in the angle adjustment screw, the mounting block 52 can be rotated; while by screwing in the fiber optic fixing screw, the transmitting end T or receiving end R in the fiber optic jack 56 can be locked. Specifically, the operator uses a tool to rotate the angle adjustment screw. Since the angle adjustment screw and the fixing base 51 are threaded together, rotation will cause the angle adjustment screw to produce a precise axial displacement. The bottom of the angle adjustment screw presses against one side of the mounting block 52. The forward pushing force can be decomposed into a torque that pushes the mounting block 52 to rotate about its axis. Under the action of this torque, the mounting block 52 will rotate a small angle (for example, if the screw advances 0.2mm, the mounting block 52 rotates 1°), thereby changing the angle of the fiber optic sensor end installed therein. After the fiber optic sensor angle is adjusted to the optimal position, the fiber optic fixing screw is tightened. The fiber optic fixing screw presses the fiber optic sensor in the fiber optic jack 56, and the generated static friction locks the fiber optic sensor in the mounting block 52, preventing it from sliding or shifting in a vibration environment, and ensuring the long-term stability of the calibrated angle. Throughout the adjustment process, the return spring remains under compression or tension, generating a continuous elastic restoring torque opposite to the adjustment direction. This ensures that the mounting block 52 maintains tight contact with the top of the angle adjustment screw, eliminating mechanical backlash and ensuring a smooth adjustment process. After adjustment, the angle adjustment device 5 is firmly held at the set angle position by the self-locking property of the angle adjustment screw and the tightening force of the fiber optic fixing screw. This resists external vibrations and impacts, maintaining long-term stability of the optical path.

[0063] As described above, the present invention achieves high-precision and high-stability calibration and maintenance of the optical path through the combination of mounting block, angle adjustment component, optical fiber fixing component and return spring.

[0064] Based on the above embodiments, it also includes: The friction module is located downstream of the deceleration sensor 32 and is used to apply a preset friction force to the surface of the board 4 when the transmission mechanism 2 decelerates.

[0065] In one embodiment, a friction module is further disposed downstream of the deceleration sensor 32. The friction module is used to further apply frictional force to the surface of the board 4 when the transmission mechanism 2 decelerates, to prevent overshoot and ensure a smooth stop for the board 4. In one embodiment, the friction module includes a cylinder-driven friction plate. When the board transmission positioning system detects that the deceleration sensor 32 has been triggered, it immediately drives the cylinder piston rod to extend, pushing the friction plate to contact the surface of the board 4 with a certain pressure, generating a frictional force opposite to the direction of movement of the board 4, assisting the board 4 in rapid deceleration. Furthermore, the friction plate adopts a detachable design, allowing for quick replacement after wear.

[0066] As described above, this utility model embodiment adds a friction module to the board transmission and positioning system. The friction module provides a controllable auxiliary braking force during the board deceleration process, effectively consuming the board's kinetic energy inertia, suppressing the board's overshoot phenomenon, and improving the stopping accuracy.

[0067] Based on the above embodiments, it also includes: The clamping mechanism is located on the side of the transmission mechanism 2, corresponding to the detection position of the stop sensor 33, and is used to clamp and fix the board 4 after the board 4 stops.

[0068] In this embodiment, the board transfer and positioning system also includes a clamping mechanism. The clamping point of the clamping mechanism is aligned with the detection position of the optical path of the stop sensor 33 in the transfer direction of the board 4. The clamping mechanism is installed on both sides of the transfer mechanism 2 to ensure that when the board 4 moves to the point where the stop sensor 33 is triggered, its main body has already entered the effective range of the clamping mechanism. The board transfer and positioning system can immediately control the clamping mechanism to accurately clamp the board 4 at the predetermined theoretical stopping point, thereby providing a stable platform with zero wobbling for high-precision detection (such as AOI). In one embodiment, the clamping mechanism may include a pair of symmetrically arranged cylinders and grippers. When the stop sensor 33 is triggered and the transfer mechanism 2 stops, the cylinders drive the grippers on both sides to move simultaneously towards the center, clamping the board 4 from both sides.

[0069] As described above, by adding a clamping mechanism, this utility model embodiment can provide a stable clamping force from both sides after the board has come to a stop, completely eliminating any possible slight shaking or slippage of the board, and providing a stable reference platform for subsequent automated optical inspection, thereby ensuring the accuracy of the inspection.

[0070] Based on the above embodiments, it also includes: A width adjustment mechanism, connected to the transmission mechanism 2, is used to adjust the width of the transmission mechanism 2 to accommodate boards 4 of different sizes; A closed-loop width-adjusting motor is connected to the width-adjusting mechanism and is used to control the width-adjusting mechanism to adjust the width.

[0071] In one embodiment, the board transmission positioning system further includes a width adjustment mechanism and a closed-loop width adjustment motor. The closed-loop width adjustment motor is driven and connected to the width adjustment mechanism. This drive connection means that the output shaft of the closed-loop width adjustment motor is directly mechanically coupled to the input end of the width adjustment mechanism (such as a ball screw or worm gear) through a physical transmission component (such as a coupling, synchronous belt, or gear set). This connection method ensures that the rotational torque and precise angular motion generated by the motor can be transmitted to the width adjustment mechanism without loss or slippage. The closed-loop width adjustment motor is typically a servo motor or stepper motor with an encoder. After receiving a width setting command, the closed-loop width adjustment motor begins to rotate. The output shaft of the closed-loop width adjustment motor drives the core transmission component of the width adjustment mechanism (usually a ball screw pair or a precision gear rack mechanism) through a coupling. The rotational motion of the motor is converted into precise linear motion of the nut on the screw or the slider on the rack. This linear motion is directly transmitted to the mechanically connected transmission mechanism 2 to change the width of the entire board transmission channel.

[0072] As described above, the board transmission and positioning system in this embodiment of the present invention also includes a width adjustment mechanism and a closed-loop width adjustment motor. Through the cooperation of the width adjustment mechanism and the width adjustment motor, the width of the transmission mechanism can be adjusted to adapt to boards of different sizes, thus avoiding the cumbersome process of changing tooling fixtures.

[0073] Based on the above embodiments, it also includes: The fine-tuning compensation module is used to control the transmission mechanism 2 to move in the opposite direction of the transmission direction when the stop sensor 33 is triggered and the board overshoot is detected, so as to compensate for the overshoot distance of the board 4.

[0074] In this embodiment, the board transmission and positioning system also includes a fine-tuning compensation module. This module compensates for board overshoot, which refers to the phenomenon where, after the transmission mechanism 2 stops, the board, due to its inertia, cannot immediately come to a stop and continues to move forward a distance along the original transmission direction, exceeding the preset stop position. Specifically, after the transmission mechanism 2 stops, the fine-tuning compensation module detects the position of the board 4 and determines whether its position exceeds the preset stop position. If it does, board overshoot is determined, and the fine-tuning compensation module controls the transmission mechanism 2 to move a certain distance in the opposite direction of the transmission direction to move the board 4 to the preset stop position.

[0075] For example, the fine-tuning compensation module includes a position detection unit and a drive unit. The position detection unit is an overshoot detection sensor installed downstream of the stop sensor 33, used to determine whether the board 4 exceeds the preset stop position. When the stop sensor 33 detects the edge of the board 4, the board transmission positioning system controls the transmission mechanism 2 to stop operating. If the fine-tuning compensation module detects that the overshoot detection sensor is blocked by the board 4 for a very short time (e.g., 50ms), it determines that the board has overshooted and position compensation is required. At this time, the drive unit of the fine-tuning compensation module controls the further transmission mechanism 2 to reverse, so as to drive the board 4 to move in the opposite direction of the original transmission direction to achieve position compensation.

[0076] As described above, by setting a fine-tuning compensation module, when the board overshoot is detected after the stop sensor is triggered, the transmission mechanism can be automatically controlled to move in the opposite direction to compensate for the overshoot distance. This effectively corrects the positioning deviation of the board caused by factors such as inertia, ensuring that the board accurately stops at the preset position and avoiding the impact of overshoot on the accuracy of subsequent detection, processing and other operations.

[0077] In one embodiment, such as Figure 6 As shown, Figure 6 A flowchart illustrating the board feeding process provided in this embodiment of the present invention is shown below. The control logic of the board feeding process is as follows: a. Incoming board inspection stage Triggering condition: After the board transmission and positioning system receives the board entry command, the board entry sensor 31 is blocked by the board 4.

[0078] Operation flow: The board transfer and positioning system controls the transfer mechanism 2 to operate in high-speed mode, quickly sending the board 4 into the transfer track; at the same time, it records the board entry timestamp, providing a data basis for subsequent production cycle statistics.

[0079] b. Deceleration Trigger Phase Triggering condition: Deceleration sensor 32 is blocked by board 4.

[0080] Operation Flow: The board transmission and positioning system switches the operating speed of transmission mechanism 2 from high-speed mode to low-speed mode (e.g., speed reduced from 80% to 20%); simultaneously, the friction module is activated to increase friction and achieve auxiliary deceleration, effectively suppressing the overshoot phenomenon caused by inertia of board 4. During this process, the current and load changes of the open-loop stepper motor are monitored in real time, and an alarm mechanism is triggered if any abnormality occurs.

[0081] c. Stop and Positioning Stage Triggering condition: Stop sensor 33 is blocked by board 4. For example... Figure 7 As shown, Figure 7This is a schematic diagram of a board 4 moving from the board inlet to the position corresponding to the stop sensor 33 in an embodiment of the present utility model. When the board 4 moves to the position corresponding to the stop sensor 33, it will block the light path of the stop sensor 33, thereby triggering the stop sensor 33.

[0082] Operation process: The board transmission and positioning system sends a stop command to the open-loop stepper motor of the transmission mechanism 2 to achieve a soft landing stop without mechanical collision; the stop signal is synchronously uploaded to the host computer and sent to the automated optical inspection equipment to notify it that it can prepare for automated optical inspection.

[0083] d. Clamping and fixing stage Operation flow: Activate the clamping mechanism to perform the clamping action, reliably fixing the already stationary board 4. Subsequent automated optical inspection equipment can then perform automated optical inspection on board 4.

[0084] After the automated optical inspection equipment completes the automated optical inspection of board 4, the subsequent board ejection process can be executed. In one embodiment, such as... Figure 8 As shown, Figure 8 This is a schematic diagram of a board ejection process provided by an embodiment of the present utility model. The control logic of the board ejection process is as follows: a. Unpacking and Inspection Stage Triggering condition: The board transmission and positioning system receives the board eject command.

[0085] Action flow: Control the clamping mechanism to release the clamping state of board 4.

[0086] b. High-speed plate ejection stage Operation flow: Control transmission mechanism 2 to operate in high-speed mode.

[0087] c. Board exit confirmation and reset stage.

[0088] Triggering condition: The outlet sensor 34 is blocked or changes from a blocked state to an unblocked state. For example... Figure 9 As shown, Figure 9 This is a schematic diagram illustrating how a board 4 moves from a stop position to the position corresponding to the outlet sensor 34, as provided in an embodiment of this utility model. When the board 4 moves from the stop position to the position where the outlet sensor 34 is located, blocking the optical path of the outlet sensor 34, the outlet sensor 34 is triggered.

[0089] Operation flow: After detecting the downstream device sending a board request signal, the transmission mechanism 2 is restarted to smoothly transport board 4 to the downstream area; after board delivery is completed, all relevant sensors and actuators are reset to prepare for the transmission and positioning of the next board 4.

[0090] This utility model embodiment also provides an automated optical inspection device, including an automated optical inspection module for automated optical inspection of circuit boards and the aforementioned circuit board transmission and positioning system. This utility model embodiment establishes a complete circuit board position sensing and transport speed control system by setting four sets of photoelectric sensors—an inlet sensor, a deceleration sensor, a stop sensor, and an outlet sensor—arranged sequentially along the transmission direction of the circuit boards. This achieves contactless stopping of the circuit boards, fundamentally avoiding physical collisions and scratches caused by using mechanical blocks to obstruct the circuit boards, ensuring the circuit boards remain undamaged, and solving the technical problem that traditional methods of physically obstructing circuit boards easily damage them.

[0091] Note that the above are merely preferred embodiments and the technical principles applied in this utility model. Those skilled in the art will understand that this utility model is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the protection scope of this utility model. Therefore, although the embodiments of this utility model have been described in detail above, this utility model is not limited to the above embodiments. More other equivalent embodiments may be included without departing from the concept of this utility model, and the scope of this utility model is determined by the scope of the appended claims.

Claims

1. A board transmission and positioning system, characterized in that, include: A rack is used to provide structural support and mounting reference for the various components of a system. A transmission mechanism, mounted on the rack, is used to transport circuit boards; Multiple sets of photoelectric sensors include an inlet sensor for detecting the board entering, a deceleration sensor for triggering the transmission mechanism to decelerate when the board is detected, a stop sensor for triggering the transmission mechanism to stop when the board is detected, and an outlet sensor for detecting the board leaving. The inlet sensor, the deceleration sensor, the stop sensor, and the outlet sensor are sequentially fixed on the frame along the transmission direction of the transmission mechanism.

2. The board transmission and positioning system according to claim 1, characterized in that, The photoelectric sensor includes a through-beam photoelectric sensor; each group of photoelectric sensors includes a pair of through-beam photoelectric sensors; each pair of through-beam photoelectric sensors includes a transmitter and a receiver arranged opposite to each other.

3. The board transmission and positioning system according to claim 1, characterized in that, The photoelectric sensor is a through-beam fiber optic sensor; At least one of multiple sets of through-beam fiber optic sensors has its transmitter and receiver positioned opposite each other on a plane perpendicular to the board. A signal is triggered by a change in light flux caused by the thickness of the board obstructing the light path as it passes by; or... At least one of the multiple sets of through-beam fiber optic sensors has its transmitter and receiver positioned on opposite sides of the plane where the board is located, so that when the board passes by, it completely blocks the optical path trigger signal between the transmitter and the receiver.

4. The board transmission and positioning system according to claim 1, characterized in that, The photoelectric sensor is a through-beam fiber optic sensor; at least one of the multiple through-beam fiber optic sensors has its transmitting end and receiving end arranged on opposite sides of the plane where the board is located, so that when the board passes by, it completely blocks the optical path trigger signal between the transmitting end and the receiving end, and at least one end of the transmitting end and the receiving end is mounted on the rack through an angle adjustment device.

5. The board transmission and positioning system according to claim 4, characterized in that, The angle adjustment device includes: A mounting bracket installed on the frame; The mounting block is rotatably mounted on the fixed base and is used to mount the transmitter or receiver. An angle adjustment mechanism, connected to the fixed base and the mounting block, is used to drive the mounting block to rotate around a rotation center to adjust the angle of the mounting block; A locking mechanism is used to fix the transmitter or the receiver to the mounting block; An elastic reset element is used to provide an elastic force to reset the mounting block to its initial position.

6. The board transmission and positioning system according to claim 5, characterized in that, The mounting block is provided with an optical fiber jack, which is used to insert the transmitting end or the receiving end of the through-beam optical fiber sensor. The angle adjustment mechanism is an angle adjustment component connected to the fixed base and the mounting block. By screwing it in or out, its protrusion depth is changed to push the mounting block to rotate. The locking mechanism is an optical fiber fastener connected to the mounting block, used to lock the transmitter or receiver inserted into the optical fiber jack. The elastic reset element is a return spring disposed between the fixed base and the mounting block.

7. The board transmission and positioning system according to claim 1, characterized in that, Also includes: A friction module is disposed downstream of and adjacent to the deceleration sensor, and is used to apply a preset friction force to the surface of the board when the transmission mechanism decelerates.

8. The board transmission and positioning system according to claim 1, characterized in that, Also includes: A clamping mechanism is disposed on the side of the transmission mechanism corresponding to the detection position of the stop sensor, and is used to clamp and fix the board after the board stops; A width adjustment mechanism, connected to the transmission mechanism, is used to adjust the width of the transmission mechanism to accommodate boards of different sizes; A closed-loop width-adjusting motor is driven and connected to the width-adjusting mechanism to control the width-adjusting mechanism to adjust the width.

9. The board transmission and positioning system according to claim 1, characterized in that, Also includes: The fine-tuning compensation module is used to control the transmission mechanism to move in the opposite direction of the transmission direction when the stop sensor is triggered and the overshoot of the board is detected, so as to compensate for the overshoot distance of the board.

10. An automated optical inspection device, characterized in that, It includes an automated optical inspection module for performing automated optical inspection of circuit boards and a circuit board transmission and positioning system as described in any one of claims 1 to 9.

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