Constant temperature control system of visual inspection camera

Abstract

The utility model discloses a constant temperature control system of a visual inspection camera. The constant temperature control system comprises a heat dissipation shell and a semiconductor cooler which are arranged on a camera lens, a magnetic suspension centrifugal radiator arranged on a camera body, a temperature sensor used for detecting the working temperature of the camera, and a controller, the heat dissipation shell comprises a heat conduction substrate, a vacuum cavity temperature equalizing plate and a heat insulation layer which are arranged in sequence, and the heat conduction substrate layer is in interference fit with the camera lens barrel; the controller comprises a data acquisition unit and a control unit, the data acquisition unit is used for monitoring the rotating speed of the magnetic suspension centrifugal radiator and the vibration frequency spectrum of the camera body, the data acquisition unit is electrically connected with the control unit, and the control unit is electrically connected with the semiconductor cooler, the temperature sensor and the magnetic suspension centrifugal radiator. And the adjusting module is used for adjusting working parameters of the semiconductor cooler and the magnetic suspension centrifugal radiator.

Description

Technical Field

[0001] This utility model relates to the technical field of precision processing equipment for printed circuit boards, and specifically to a constant temperature control system for a visual inspection camera. Background Technology

[0002] Visual inspection cameras are mainly used in industrial inspection for image analysis and recognition, and visual inspection and judgment. They have functions such as color presence / absence discrimination, color area calculation, contour finding and positioning, object feature grayscale matching, color or grayscale intensity detection, object counting, size measurement, barcode / QR code recognition and reading, mechanical guide positioning, and character recognition.

[0003] Visual inspection cameras typically operate in industrial automation environments, performing visual inspections on targets. The lens is aimed at the target and takes real-time pictures, which are then used for motion tracking and positioning, defect feature recognition and quality inspection, object counting, and other purposes.

[0004] Due to the characteristics of industrial vision inspection, most of the targets are objects on automated production lines. Therefore, the lenses of vision inspection cameras are usually set vertically or obliquely downwards during the design process. However, the temperature of the inspection environment in industrial automation sites is uncertain and may change significantly due to adjustments in the production process. The changing temperature, especially when the high-temperature airflow emitted by the inspection target rises, can interfere with the vision inspection camera.

[0005] In existing technologies, temperature control for electronic components such as vision inspection cameras primarily focuses on the circuit board, specifically the heat dissipation of the camera chip to ensure its performance. For example, in temperature control devices for cameras used in hole position measuring instruments for PCB drilling machines, traditional air cooling can cause airflow disturbances within the camera, affecting measurement stability. Furthermore, existing temperature control devices neglect constant temperature control of the vision inspection camera lens. During actual inspection, the influence of hot or cold airflow can significantly interfere with the camera's imaging; a 1°C change in lens temperature can lead to a 0.02% image shift, failing to meet the 5µm resolution requirement for micro-hole inspection on high-density multilayer PCBs. Simultaneously, existing temperature control devices cannot simultaneously meet the requirements for rapid heating and cooling and ultra-low vibration (≤0.1gRMS).

[0006] Therefore, the purpose of this utility model is to provide a new constant temperature control system for a visual inspection camera to solve the above-mentioned technical problems. Utility Model Content

[0007] The technical problem to be solved by this utility model is to provide a constant temperature control system for a visual inspection camera, which enables the temperature difference between the CMOS area and the lens of the visual inspection camera to be ≤0.03℃, the camera to have good thermal stability, and can simultaneously meet the requirements of rapid heating and cooling and ultra-low vibration; it can also enable the camera to maintain thermal stability in an environment of -10℃ to 50℃, the PCB drilling position measurement accuracy can reach ±0.8μm, and the yield rate can be improved by more than 15%.

[0008] The technical solution of this utility model is as follows:

[0009] A constant temperature control system for a visual inspection camera includes a heat dissipation housing and a semiconductor cooler disposed on the camera lens, a magnetic levitation centrifugal heat sink disposed on the camera body, a temperature sensor for detecting the operating temperature of the camera, and a controller.

[0010] The heat dissipation housing includes a heat-conducting substrate, a vacuum chamber heat-equalizing plate, and a heat insulation layer arranged in sequence, and the heat-conducting substrate layer is interference-fitted with the camera lens barrel;

[0011] The controller includes a data acquisition unit for monitoring the rotational speed of the magnetic levitation centrifugal radiator and the vibration spectrum of the camera body, and a control unit. The data acquisition unit and the control unit are electrically connected, and the control unit is electrically connected to the semiconductor cooler, the temperature sensor and the magnetic levitation centrifugal radiator, for adjusting the operating parameters of the semiconductor cooler and the magnetic levitation centrifugal radiator.

[0012] Furthermore, the semiconductor cooler is installed between the thermally conductive substrate and the vacuum chamber vapor chamber plate. When the semiconductor cooler is used for lens heat dissipation, the hot end of the semiconductor cooler is in contact with the vacuum chamber vapor chamber plate.

[0013] Furthermore, the semiconductor cooler consists of multiple wafers arranged in a ring array.

[0014] Furthermore, the power of a single-chip semiconductor cooler is 5-10W.

[0015] Furthermore, multiple semiconductor coolers are arranged in a circular pattern with equal angles.

[0016] Furthermore, the spacing between two adjacent semiconductor coolers is 1 / 6 to 1 / 8 of the lens diameter.

[0017] Furthermore, the vacuum chamber is filled with nano-alumina thermal conductive liquid within the temperature-equalizing plate layer.

[0018] Furthermore, the temperature sensors consist of four sets, which are used to detect the temperature of the camera lens flange, CMOS chip, filter, and body, respectively.

[0019] Compared with the prior art, the constant temperature control system for the visual inspection camera provided by this utility model has the following advantages:

[0020] I. The constant temperature control system of the visual inspection camera provided by this utility model adopts a temperature regulation technology that combines a semiconductor cooler and a vacuum chamber heat exchanger for the camera lens, and a magnetic levitation centrifugal heat sink for heat dissipation for the body. The working parameters of the semiconductor cooler and the magnetic levitation centrifugal heat sink are controlled by a controller, so that the temperature difference between the CMOS area of ​​the visual inspection camera and the lens can be ≤0.03℃, thereby eliminating thermal stress deformation caused by temperature difference.

[0021] II. The constant temperature control system of the visual inspection camera provided by this utility model adopts a magnetic levitation centrifugal heat sink for heat dissipation of the body. The shaftless contact design has a vibration value of <0.05g, which meets the ultra-low vibration requirements of the visual inspection camera. At the same time, compared with traditional air cooling, the magnetic levitation centrifugal heat sink saves 62% energy and can meet the needs of long-term continuous operation.

[0022] III. The constant temperature control system of the visual inspection camera provided by this utility model, through temperature and vibration coordinated control technology, enables ultra-precise temperature control under complex working conditions, and can simultaneously meet the requirements of rapid heating and cooling and ultra-low vibration. This allows the camera to maintain thermal stability in environments ranging from -10℃ to 50℃, achieves PCB drilling position measurement accuracy of ±0.8μm, and improves the yield rate by more than 15%. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the constant temperature control system of the visual inspection camera of this utility model.

[0025] Figure 2 This is a structural schematic diagram of the lens in the constant temperature control system of the visual inspection camera of this utility model from another angle.

[0026] Figure 3 This is a block diagram illustrating the control principle of the constant temperature control system for the visual inspection camera of this utility model. Detailed Implementation

[0027] To enable those skilled in the art to better understand the technical solutions in the embodiments of this utility model, and to make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be further described below in conjunction with the accompanying drawings.

[0028] It should be noted that the descriptions of these embodiments are for the purpose of aiding understanding of the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0029] Please refer to the following: Figure 1 and Figure 2 ,in Figure 1 This is a schematic diagram of the constant temperature control system of the visual inspection camera of this utility model. Figure 2 This is a schematic diagram of the lens structure from another angle in the constant temperature control system of the visual inspection camera of this utility model. The visual inspection camera includes a body 101, a lens 102 disposed at the front end of the body 101, wherein the lens 102 includes lens elements 103 and a lens barrel 104 for fixing the lens elements. The constant temperature control system of the visual inspection camera of this utility model includes a heat dissipation housing 1 disposed on the lens, a semiconductor cooler 2 disposed on the lens, a magnetic levitation centrifugal heat sink 3 disposed on the body, a temperature sensor 4 for detecting the operating temperature of the camera, and a controller 5.

[0030] The heat dissipation housing 1 includes a thermally conductive substrate 11, a vacuum chamber heat exchange plate 12, and a heat insulation layer 13 arranged sequentially. The thermally conductive substrate 11 is interference-fitted with the mirror barrel 104 and is made of copper-tungsten alloy thermally conductive substrate with a coefficient of thermal expansion (CTE) of 6.5 × 10⁻⁶. -6 / ℃; The main function of the vacuum chamber heat spreader 12 is to efficiently transfer and uniformly distribute heat. By utilizing the phase change heat transfer principle in a vacuum environment, heat is rapidly transferred from the heat source to the entire surface of the heat spreader, thereby achieving efficient heat dissipation and uniform temperature distribution. The vacuum chamber heat spreader 12 is filled with boron nitride nano-modified conductive liquid, with a latent heat of phase change ≥280J / g. The heat insulation layer 13 is a ceramic fiber reinforced epoxy resin heat insulation cover with a thermal conductivity ≤0.03W / m·K.

[0031] A thermoelectric transducer (TEC) is a device based on the thermoelectric effect. Its working principle utilizes the properties of semiconductor materials to convert electrical energy into heat or cold energy. Under the influence of an applied electric field, current generates heat within the semiconductor and carries this heat from one end of the TEC to the other, creating a "hot" side and a "cold" side. When the current direction is reversed, the hot and cold sides of the TEC switch, meaning the previously hot side becomes the cold side, and vice versa. This is the heating and cooling principle of a TEC.

[0032] In this embodiment, the thermoelectric cooler 2 can be disposed between the thermally conductive substrate 11 and the vacuum chamber vapor chamber heat exchanger 12. When used for lens heat dissipation, the hot end of the thermoelectric cooler 2 contacts the vacuum chamber heat exchanger 12. The thermoelectric cooler TEC actively cools through the Peltier effect, rapidly reducing the temperature of the camera lens. The vacuum chamber heat exchanger has extremely high thermal conductivity, quickly transferring heat from the hot end of the thermoelectric cooler to the heat dissipation area, preventing the hot end temperature from becoming too high. The combined use of the thermoelectric cooler and the vacuum chamber heat exchanger achieves a lower temperature outside the lens barrel and a more uniform heat distribution. When the ambient temperature is too low and lens heating is required, the current direction of the thermoelectric cooler is changed, causing the hot end of the thermoelectric cooler 2 to contact the thermally conductive substrate 11, thereby heating the lens and preventing condensation on the lens.

[0033] In addition to the above solutions, semiconductor coolers can also be installed in areas such as lens hoods.

[0034] In this embodiment, the thermoelectric cooler consists of multiple pieces arranged in a circular array. Specifically, the power of a single thermoelectric cooler is 5-10W, and its power is adjustable. During installation, the multiple thermoelectric coolers are arranged in a circular pattern at equal angles, with the distance between two adjacent thermoelectric coolers being 1 / 6 to 1 / 8 of the lens diameter. In this embodiment, there are eight thermoelectric coolers.

[0035] The magnetic levitation centrifugal radiator 3 is located on one side of the body. It has a shaftless contact design and a vibration value of <0.05g, which meets the ultra-low vibration requirements of the visual inspection camera. At the same time, compared with traditional air cooling, the magnetic levitation centrifugal radiator saves 62% energy and can meet the needs of long-term continuous operation.

[0036] In this embodiment, multiple temperature sensors 4 are used to detect the operating temperature of the camera lens flange, CMOS chip, filter, and camera body. Based on real-time monitoring data, the operating status of the visual inspection camera can be monitored. PT100 platinum resistance thermometers can be selected as the temperature sensors.

[0037] Please see Figure 3This is a block diagram illustrating the control principle of the constant temperature control system for the visual inspection camera of this invention. The controller 5 is a temperature-vibration coupled controller, comprising a data acquisition unit 51 and a control unit 52, with the data acquisition unit electrically connected to the control unit. The data acquisition unit 51 monitors the rotational speed of the magnetic levitation centrifugal radiator and the vibration spectrum of the camera body, and sends the acquired data to the control unit 52. The control unit 52 is electrically connected to the semiconductor cooler 2, the temperature sensor 3, and the magnetic levitation centrifugal radiator 4. The temperature sensor 3 transmits multi-point operating temperature detection signals to the control unit, and, combined with the operating parameters of the magnetic levitation centrifugal radiator and the vibration spectrum of the camera body, adjusts the power of the semiconductor cooler and the rotational speed of the magnetic levitation centrifugal radiator. By adjusting the power of the semiconductor cooler, the temperature of its hot end can be adjusted; by adjusting the rotational speed of the magnetic levitation centrifugal radiator, the heat dissipation effect and vibration spectrum can be adjusted.

[0038] The constant temperature control system of the visual inspection camera of this invention enables the visual inspection camera to be used in high-temperature conditions or cold start scenarios.

[0039] When the ambient temperature rises to 38℃, the TEC cooling is activated 10 seconds in advance. The phase change material of the vacuum chamber heat exchange plate absorbs the instantaneous thermal shock and controls the rotation speed of the magnetic levitation centrifugal radiator to 12,000 rpm, maintaining the TEC hot end temperature ≤45℃.

[0040] When the system is initially powered on and the ambient temperature is less than or equal to 10°C, the lens assembly changes the current direction of the semiconductor cooler to bring the hot end into contact with the heat-conducting substrate, and adopts a stepped heating strategy, such as increasing the temperature by 2°C per minute, to avoid condensation on the lens.

[0041] The constant temperature control system of the visual inspection camera of this invention combines a vacuum chamber temperature equalization plate with a semiconductor cooler to ensure that the temperature difference between the lens and the CMOS area is ≤0.03℃, thereby eliminating thermal stress deformation.

[0042] Applying the constant temperature control system of the visual inspection camera of this utility model to the accuracy detection of PCB drilling hole positions can enable the camera to maintain thermal stability in an environment ranging from -10℃ to 50℃, and the PCB drilling hole position measurement accuracy can reach ±0.8μm, improving the yield rate by more than 15%.

[0043] The embodiments of this utility model have been described in detail above with reference to the accompanying drawings, but this utility model is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations made to these embodiments without departing from the principles and spirit of this utility model still fall within the protection scope of this utility model.

Claims

1. A constant temperature control system for a visual inspection camera, characterized in that, It includes a heat dissipation housing and semiconductor cooler installed on the camera lens, a magnetic levitation centrifugal heat sink installed on the camera body, a temperature sensor for detecting the camera's operating temperature, and a controller; The heat dissipation housing includes a heat-conducting substrate, a vacuum chamber heat-equalizing plate, and a heat insulation layer arranged in sequence, and the heat-conducting substrate layer is interference-fitted with the camera lens barrel; The controller includes a data acquisition unit for monitoring the rotational speed of the magnetic levitation centrifugal radiator and the vibration spectrum of the camera body, and a control unit. The data acquisition unit and the control unit are electrically connected, and the control unit is electrically connected to the semiconductor cooler, the temperature sensor and the magnetic levitation centrifugal radiator, for adjusting the operating parameters of the semiconductor cooler and the magnetic levitation centrifugal radiator.

2. The constant temperature control system for the visual inspection camera according to claim 1, characterized in that, The semiconductor cooler is installed between the thermally conductive substrate and the vacuum chamber heat exchanger. When the semiconductor cooler is used for lens heat dissipation, the hot end of the semiconductor cooler is in contact with the vacuum chamber heat exchanger.

3. The constant temperature control system for the visual inspection camera according to claim 1 or 2, characterized in that, The semiconductor cooler consists of multiple wafers arranged in a ring array.

4. The constant temperature control system for the visual inspection camera according to claim 3, characterized in that, The power of a single-chip semiconductor cooler is 5-10W.

5. The constant temperature control system for the visual inspection camera according to claim 3, characterized in that, Multiple semiconductor coolers are arranged in a circular pattern with equal angles.

6. The constant temperature control system for the visual inspection camera according to claim 5, characterized in that, The distance between two adjacent semiconductor coolers is 1 / 6 to 1 / 8 of the lens diameter.

7. The constant temperature control system for the visual inspection camera according to claim 1, characterized in that, The vacuum chamber is filled with nano-alumina thermal conductive liquid in the heat-dissipating plate layer.

8. The constant temperature control system for the visual inspection camera according to claim 1, characterized in that, The temperature sensors consist of four sets, which are used to detect the temperature of the camera lens flange, CMOS chip, filter, and body, respectively.

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