Uniform light source device for flat field correction

Abstract

The utility model discloses a uniform light source device for flat field correction, and belongs to the field of flat field correction. The uniform light source device comprises an area light source, a shading box, a TEC (thermoelectric cooler) arranged inside or on the surface of the area light source and used for reducing the temperature of a light-emitting part of the area light source, the illuminance sensor is arranged at any illuminance non-zero position on a non-shielding light emitting path in the shading box and is used for indirectly judging the illuminance change of a light outlet of the shading box; and the controller is connected with the TEC control circuit and the light source driver, and controls the TEC working voltage and the light source driving voltage according to the illumination change fed back by the illumination sensor so as to ensure that the illumination of the light outlet of the shading box is kept stable. Based on the structure, the controller can adjust the temperature of the area light source through the TEC so as to maintain the temperature of the area light source to be constant, the illuminance change of the light outlet of the shading box is judged according to the illuminance sensor, the driving voltage of the light source is adjusted, and the uniformity of the area light source is improved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the field of flat field correction, especially relates to a uniform light source device for flat field correction. BACKGROUND

[0002] Due to the limitation of production process, the image generated by the image sensor often has defects such as bad points, horizontal or vertical stripes, and non-uniformity in space. The above defects can be solved by flat field correction of the camera under uniform light source. Therefore, in the test or flat field correction process of the camera, the test device needs to provide stable and uniform light source for detecting the performance parameters of the camera and verifying the functional characteristics of the camera.

[0003] The existing uniform light source device often lacks temperature control structure, which not only needs a very long time for thermal stability, but also easily causes the uniform light provided by the light source to fluctuate.

[0004] Therefore, there is an urgent need for a uniform light source device to solve the above problems. INVENTION CONTENTS

[0005] The utility model provides a kind of uniform light source device for improving the stability of uniform light source.

[0006] To achieve the above object, the utility model provides the following technical scheme:

[0007] The utility model provides a kind of uniform light source device for flat field correction, including area light source and light shield box only for the light of area light source to enter, it is built-in multiple containing baffle of through-hole to remove non-light direction light, still include:

[0008] TEC, is arranged in area light source interior or surface, for reducing the temperature of area light source luminous part;

[0009] Illuminance sensor, is arranged in any illuminance non-zero place on the non-shield light path in light shield box, for indirectly judging the illuminance change of light shield box light outlet;

[0010] Controller, connects TEC control circuit, light source drive, and controller controls TEC working voltage and light source drive voltage according to the illuminance change of illuminance sensor feedback, to ensure that the illuminance of light shield box light outlet maintains stable.

[0011] Optionally, it further includes: integrating sphere light source, for replacing area light source, and integrating sphere light source light outlet is installed in light shield box light inlet;Wherein, TEC is arranged in the interior or surface of the integrating sphere light source, for reducing the temperature of integrating sphere light source luminous part.

[0012] Optionally, the TEC is located on the back of the light-emitting part inside the surface light source, or on the back of the PCB board inside the surface light source, to directly reduce the temperature of the light-emitting part.

[0013] Optionally, the TEC can be replaced by one or any combination of water-cooled equipment, air-cooled equipment, or compressor refrigeration equipment.

[0014] Optionally, it also includes one or any combination of water-cooled equipment, air-cooled equipment or compressor refrigeration equipment, which is connected to the light-emitting part through a heat conduction medium or directly, or whose cooling end is connected to the heating end of the TEC, and used in combination with the TEC to reduce the temperature of the light-emitting part.

[0015] Optionally, the areas where the illuminance sensor is installed include: the area on the baffle excluding the through holes, and the area on the inner wall of the light-shielding box excluding the light outlet and the light inlet.

[0016] Optionally, the illuminance sensor located inside the light-shielding box can be replaced with an illuminance sensor located outside the light-shielding box; wherein the illuminance sensor is located in one or more places inside the surface light source or the camera under test.

[0017] Optionally, the illuminance sensor located inside the light-shielding box can be replaced with an illuminance sensor located outside the light-shielding box. The illuminance sensor can also be located at one or more points between the surface light source and the light-shielding box, and between the camera under test and the light-shielding box. Light-shielding plates are installed in the gaps between the light-shielding box and the surface light source and the camera under test to block ambient light, so that the detection value of the illuminance sensor corresponds to the illuminance at the light outlet of the light-shielding box.

[0018] Optionally, it also includes: a light-diffusing plate, which is disposed on the surface of the light-emitting part inside the surface light source, between the surface light source and the light inlet of the light-shielding box, on the inner walls at both ends of the light-shielding box or on the baffle, and completely covers any light-emitting surface in the light-emitting path.

[0019] Optionally, the plurality of baffles are parallel to the light inlet and light outlet of the light-shielding box, and the light outlet of the surface light source or integrating sphere light source coincides with the central axis of the light inlet, light outlet and through hole of the light-shielding box.

[0020] The beneficial effects of this utility model are as follows:

[0021] This utility model provides a uniform light source device, including a surface light source and a light-shielding box that allows only the light from the surface light source to enter. The box contains multiple baffles with through holes to block light from non-emitting directions. It also includes:

[0022] TEC is installed inside or on the surface of a surface light source to reduce the temperature of the light-emitting part of the surface light source;

[0023] An illuminance sensor is arranged at any non-zero illuminance position on the non-shielded light-emitting path in the light-shield box, and is used for indirectly judging the illuminance change of the light-emitting port of the light-shield box.

[0024] A controller is connected to the TEC control circuit and the light source driver, and controls the working voltage of the TEC and the driving voltage of the light source according to the illuminance change fed back by the illuminance sensor, so as to maintain the stable illuminance of the light-emitting port of the light-shield box.

[0025] Based on the above structure, the light-shield box can shield the ambient light outside the box body, and prevent the ambient light from entering the photosensitive surface of the measured camera, so as to improve the uniformity of the area light source. Meanwhile, the controller can adjust the temperature of the area light source by using the TEC, so as to maintain the constant temperature of the area light source, and avoid the fluctuation of the light source caused by the temperature fluctuation, thereby improving the uniformity of the area light source. In addition, according to the detection value of the illuminance sensor on the illuminance in the light-shield box, the illuminance change of the light-emitting port of the light-shield box can be judged, and the driving voltage of the light source is adjusted according to the detection value by the controller, so as to maintain the stability of the light-emitting port of the light-shield box, and improve the uniformity of the area light source. BRIEF DESCRIPTION OF DRAWINGS

[0026] The accompanying drawings, which are included to provide a further understanding of the present application and are incorporated in and constitute a part of this application, illustrate embodiments of the present application and serve to explain the present application. In the drawings:

[0027] Figure 1 is a schematic view of a uniform light source device provided by the present application;

[0028] Figure 2 is a structural schematic view of a light-shield box provided by the present application;

[0029] Figure 3 is a structural schematic view of a through hole provided by the present application.

[0030] In the drawings: 1-area light source; 2-light-shield box; 3-measured camera; 4-TEC; 5-controller; 6-illuminance sensor; 7-baffle; 8-through hole; 9-light-blocking sheet; 21-light-inlet port of light-shield box; 22-light-emitting port of light-shield box. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are some embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0032] The flat field correction and performance detection of the camera need to be carried out under a uniform light source, and therefore the stability of the uniform light source is very important for the production and use of the camera.

[0033] In the existing flat field correction or optical test of the camera, an integrating sphere light source is generally used for the related test.The main disadvantage of the integrating sphere light source is that a temperature control structure is lacked, and a long time is needed for the thermal stability of the device, and the fluctuation of the temperature leads to the fluctuation of the light source.

[0034] In addition, a portable plane light source is also often used in the test of the camera, and the open structure of the plane light source leads to serious light leakage during the test, and the plane light source also lacks a temperature control device and cannot be used in a high-precision test scene. In order to solve the above problems, the utility model provides a uniform light source device for flat field correction, as shown in the figure, the uniform light source device comprises: Figures 1-2

[0035] a surface light source 1 and a light shielding box 2 for the light of the surface light source 1 to enter only, a plurality of baffles 7 with through holes 8 are arranged in the light shielding box 2 to remove the light in the non-light emission direction.

[0036] A TEC 4 (Thermo Electric Cooler, semiconductor cooler) is arranged in the surface light source 1 or on the surface of the surface light source 1 and is used for reducing the temperature of the light emitting part of the surface light source 1.

[0037] An illuminance sensor 6 is arranged at any non-zero illuminance position on the non-shielded light emission path in the light shielding box 2 and is used for indirectly judging the illuminance change of the light shielding box light outlet 22.

[0038] A controller 5 is connected with a TEC 4 control circuit and a light source drive, and the controller 5 controls the working voltage of the TEC 4 and the driving voltage of the light source according to the illuminance change fed back by the illuminance sensor 6, so as to ensure that the illuminance of the light shielding box light outlet 22 is maintained stable.

[0039] Based on the above structure, the light shielding box 2 can shield the ambient light outside the box body and prevent the ambient light from entering the photosensitive surface of the measured camera 3, so as to improve the uniformity of the surface light source 1. Meanwhile, the controller 5 can adjust the temperature of the surface light source 1 by using the TEC 4, so as to maintain the temperature of the surface light source 1 constant, avoid the fluctuation of the light source caused by the fluctuation of the temperature, and improve the uniformity of the surface light source 1. In addition, according to the detection value of the illuminance of the light shielding box 2 detected by the illuminance sensor 6, the illuminance change of the light shielding box light outlet 22 is judged, the driving voltage of the light source is adjusted according to the detection value by the controller 5, the stability of the light shielding box light outlet 22 can be maintained, and the uniformity of the surface light source 1 is improved.

[0040] In some embodiments, the light source for generating uniform light provided by the utility model can also be an integrating sphere light source, which is used to replace the area light source 1, and the light outlet of the integrating sphere light source is installed at the light inlet 21 of the light shielding box. Wherein, the TEC 4 is arranged inside or on the surface of the integrating sphere light source, which is used to reduce the temperature of the light emitting part of the integrating sphere light source.

[0041] In some embodiments, the box body of the light shielding box 2 is composed of black matte acrylic plate or surface sandblasted black metal plate to minimize internal light reflection. Taking the acrylic plate as an example, two cross beams are respectively installed on the upper and lower box bodies made of acrylic plate material to increase the structural strength and avoid deformation.

[0042] The light shielding box 2 is used to shield ambient light to prevent the ambient light from affecting the uniformity of the light source (including the area light source 1 and the integrating sphere light source). The light shielding box 2 is provided with a light shielding box light inlet 21 and a light shielding box light outlet 22 on both sides of the box body.

[0043] The light shielding box light inlet 21 is circular and consistent in shape and size with the light outlet of the integrating sphere light source, which can reduce the gap between the two during installation, thereby avoiding light leakage and the entry of ambient light. The light shielding box light outlet 22 is rectangular or circular, and its size is matched with the size of the light sensing surface of the image sensor in the measured camera 3. The lens of the measured camera 3 is arranged in close contact with the light shielding box light outlet 22, which is used to detect the imaging performance of the measured camera 3 by using uniform light. In addition, the light emitting part of the area light source 1 is formed by a rectangular array of LED lamps.

[0044] In actual work, a mounting rack can be arranged below the measured camera 3 to adjust the position of the measured camera 3 so that the light sensing surface of the measured camera 3 is located in the middle of the light shielding box light outlet 22.

[0045] In some embodiments, a plurality of baffles 7 parallel to the light shielding box light inlet 21 and the light shielding box light outlet 22 are arranged in the light shielding box 2, and a through hole 8 is arranged at the center of each baffle 7. Moreover, the light outlet of the area light source 1 or the integrating sphere light source coincides with the central axis of the light shielding box light inlet 21, the light shielding box light outlet 22 and the through hole 8. In this way, the light outlet of the light source, the light shielding box light inlet 21, the light outlet of each baffle 7 (i.e. the through hole 8) and the light shielding box light outlet 22 are all on the same horizontal line, so that the light sensing surface of the measured camera 3 is located at the center of the optical axis, ensuring the uniformity of the light sensing surface. In addition, the light emitting direction represents the direction of light transmission from the light shielding box light inlet 21 to the light shielding box light outlet 22.

[0046] For the plurality of baffles 7 in the light box 2, the gap between adjacent baffles 7 increases as the distance from the light inlet 21 of the light box increases. The gap includes the minimum distance between the baffle 7 and the light inlet 21 of the light box. Specifically, the baffles 7 can be respectively arranged at one-half, one-fourth, one-eighth and one-sixteenth of the distance from the light inlet 21 of the light box. Based on the gap setting, the small spacing between the baffles 7 close to the light inlet 21 allows the reflected light with high intensity to be reflected back and forth between the baffles 7, thereby reducing the reflection of the light on the inner wall of the light box 2 into the photosensitive surface of the camera 3 under test. The reflected light on the baffle 7 is referred to as the non-light-out direction light of the present application.

[0047] In some embodiments, the shape of the through hole 8 is circular. When the uniform light source device provided by the present application is a surface light source 1, the diameters of the through holes 8 in different baffles 7 are the same.

[0048] In addition, to reduce the influence of the structure of the surface light source 1 on uniformity, the uniform light source device can further include a light homogenizing plate arranged on the surface of the light emitting portion of the surface light source, between the surface light source and the light inlet of the light box, on the inner wall at both ends of the light box, or on any baffle, and completely covers any light emitting surface in the light emitting path to improve the uniformity of the light emitted by the light source into the light outlet 22 of the light box. In actual work, the light homogenizing plate is usually arranged in the light box 2 and attached to the inner wall of the light box 2, covering the light inlet 21 of the light box, thereby improving the uniformity of the light emitted by the surface light source 1 into the light box 2.

[0049] When the uniform light source device provided by the present application is an integrating sphere light source, the diameter of the through hole 8 satisfies the following formula:

[0050]

[0051] Wherein, n represents the serial number of the baffle 7 in the light box 2, x n1 represents the distance between the nth baffle 7 and the light inlet 21 of the light box, x n2 represents the distance between the nth baffle 7 and the light outlet 22 of the light box, d represents the length of the diagonal line of the light outlet 22 of the light box, and D represents the diameter of the light inlet 21 in the light box.

[0052] If the through hole 8 on the baffle 7 is small, offset from the center or irregular in shape, the retracted area of the through hole 8 will block part of the light from the light outlet of the integrating sphere, causing the light from the light outlet 22 of the light box to be non-uniform.

[0053] If the through hole 8 on the baffle 7 is large, offset from the center or irregular in shape, the expanded area of the through hole 8 passes through more light, which is reflected from the edge of the through hole 8 into the photosensitive surface of the camera 3 under test, thereby reducing the uniformity of the illumination of the light outlet 22 of the light box.

[0054] Let the diameter of the integrating sphere's light exit center be D, and the diagonal of the light-shielding box's light exit 22 be d. Let the distances from the baffle to the integrating sphere's light exit and the light-shielding box's light exit be x, respectively. n1 x n2 It was obtained by converting the proportions of similar triangles.

[0055]

[0056] In some embodiments, such as Figure 3 As shown, a light-blocking plate 9 is provided at the edge of the through hole 8 of the baffle 7, and the light-blocking plate 9 is located on the side of the baffle 7 facing the light inlet 21 of the light-shielding box. The light-blocking plate 9 includes several blades, which are distributed in a rotating stack along the outer edge of the through hole 8. Specifically, the outer color of the light-blocking plate 9 is black, and the light-blocking plate 9 can be formed by fixing the blades to the baffle 7 with adhesive or black screws.

[0057] In the uniform light source device provided by this utility model, the surface light source 1 is a planar light source, which includes an open surface light source, a side-guided surface light source, and a parallel surface light source, etc. Meanwhile, the TEC4 provided by this utility model can be attached to the back of the light-emitting part within the surface light source 1 or the back of the PCB board to directly reduce the temperature of the light-emitting part, thereby improving the temperature regulation efficiency of the TEC4. Specifically, a heat-conducting block is provided on the back of the light-emitting part (i.e., the non-light-emitting surface), and the heat-conducting block is directly attached to the cooling part of the TEC4, or the PCB board within the surface light source 1 is made of pure copper to improve the thermal conductivity of the PCB board, so that the TEC4 can directly reduce the temperature of the light-emitting part.

[0058] by Figure 1 For example, surface light source 1 is an LED light board, and the PCB board on the back of the light board is a copper plate. TEC4 is attached to the back of the LED light board, and a heat sink is provided on the other side of TEC4. In addition, a temperature sensor is provided on surface light source 1 to detect the temperature value of surface light source 1.

[0059] For the light-emitting part of a surface light source, when the surface light source is an LED light panel, the light-emitting part can be an LED chip. In other types of surface light sources, the light-emitting part can also be an LED strip. For an integrating sphere light source, its light-emitting part can be represented as the light-emitting bulb inside the integrating sphere light source.

[0060] In some embodiments, TEC4 can be replaced by one or any combination of water-cooled equipment, air-cooled equipment, or compressor refrigeration equipment. Alternatively, in the uniform light source device provided by this utility model, one or any combination of water-cooled equipment, air-cooled equipment, or compressor refrigeration equipment can be added to TEC4, which is connected to the light-emitting part through a heat conduction medium or directly, or its cooling end is connected to the heating end of TEC, and used in combination with TEC to reduce the temperature of the light-emitting part.

[0061] The water-cooled device represents a device for heat dissipation by using the heat transfer performance of water, the air-cooled device represents a device for heat dissipation by using air as a heat transfer medium, and the compressor refrigeration device represents a device for heat transfer by driving a refrigerant to circulate through compression, condensation, expansion and phase change in evaporation. The refrigeration end represents one end of the above-mentioned device for heat dissipation. Specifically, the refrigeration of the above-mentioned device is through a heat transfer medium or is directly connected to the back of the light-emitting part, or the refrigeration end is connected to the heat-emitting end of the TEC 4, and is used for jointly adjusting the temperature of the light-emitting part with the TEC 4 or for rapidly reducing the temperature of the heat-emitting end of the TEC 4, thereby achieving the purpose of being used in combination with the TEC 4 to reduce the temperature of the light-emitting part. In addition, in the utility model, other types of active cooling devices can also be provided and used in combination with the TEC 4.

[0062] When the light source is an integrating sphere light source, the TEC 4 is arranged at the back of the light-emitting part in the integrating sphere light source, and is used for adjusting the temperature of the light-emitting part, thereby reducing the adverse effects of temperature fluctuation on the uniformity of the light source.

[0063] As shown in FIG. 1, the light-emitting path of the light provided by the surface light source 1 is composed of the light inlet 21 of the light shielding box, the through holes 8 and the light outlet 22 of the light shielding box. Therefore, the area of the non-shielded light-emitting path can be understood as the area on the baffle 7 except the through holes 8 or on the inner wall of the light shielding box. The illuminance sensor 6 is arranged on the area of the non-shielded light-emitting path, and the illuminance value of the area is not zero.

[0064] In some embodiments, the illuminance sensor 6 arranged in the light shielding box 2 can be arranged in the area on the baffle 7 except the through holes 8 or in the area on the inner wall of the light shielding box 2 except the light outlet and the light inlet.

[0065] The illuminance sensor 6 can also be arranged outside the light shielding box 2, as long as the light detected by the illuminance sensor 6 is only generated by the light of the surface light source 1 or the integrating sphere light source. Specifically, the illuminance sensor 6 arranged outside the light shielding box 2 is arranged in one or more of the following areas: the surface light source 1 and the measured camera 3.

[0066] In addition, the illuminance sensor 6 can also be arranged in one or more of the following areas: between the surface light source 1 and the light shielding box 2 and between the measured camera 3 and the light shielding box 2. In order to ensure that the detection value of the illuminance sensor 6 is only provided by the surface light source 1, a light shielding piece needs to be arranged on the gap between the light shielding box 2 and the surface light source 1 and the measured camera 3, for shielding ambient light, so that the detection value of the illuminance sensor 6 and the illuminance of the light outlet 22 of the light shielding box have a calibrated corresponding relationship. The calibrated corresponding relationship can be understood as a one-to-one correspondence between the detection value and the illuminance, which is used for calibrating the illuminance. The light shielding piece can also be replaced by non-transparent adhesive tape or other light shielding materials.

[0067] In actual work, the illuminance sensor 6 is usually arranged on the area of the baffle 7 except the through hole 8, for detecting the reflected light on the baffle 7, so as to generate a detection value of the illuminance, and judge the illuminance change of the light outlet 22 of the light shielding box through the detection value.

[0068] The controller 5 is connected with a TEC control circuit and a light source drive, for judging the illuminance change of the light outlet 22 of the light shielding box according to the detection value of the illuminance sensor 6, and controlling the working voltage of the TEC 4 through the temperature value detected by the temperature sensor, so as to keep the temperature of the area light source 1 constant. Meanwhile, the light source drive voltage is changed according to the change direction of the detection value of the illuminance sensor 6, so as to ensure that the light outlet 22 of the light shielding box maintains stable. The TEC drive circuit represents a circuit structure for controlling the value of the working voltage input into the TEC 4, and the light source drive represents a light source adjustment electronic device for driving the LED to emit light or normally work, which can be used for controlling the value of the light source drive voltage.

[0069] In some embodiments, the controller 5 provided by the utility model comprises:

[0070] A data acquisition module is arranged in the controller 5, for acquiring working parameters in the uniform light source device, wherein the working parameters comprise a current temperature value, a target temperature value and a minimum voltage of the TEC 4.

[0071] A first voltage adjustment module is connected with the data acquisition module, for substituting the working parameters into a preset PID control formula, so as to obtain the working voltage of the TEC 4.

[0072] Specifically, the TEC 4 is switched between the heating and refrigeration states, and the working power of the TEC 4 is controlled by the working voltage output by the controller 5. After the TEC 4 is started, in order to stabilize at room temperature, if the ambient temperature cannot be stabilized at the minimum voltage of the TEC 4, the TEC 4 needs to be switched between the refrigeration and heating states constantly, but due to the time delay characteristics of the temperature change, the temperature oscillates in the target range, which reduces the temperature control accuracy.

[0073] In order to solve the above problems, a PID control formula is arranged in the first voltage adjustment module, for realizing the temperature control strategy of the integral separation link and the dynamic amplitude limiting cold and hot switching logic judgment link, and is suitable for TEC 4s of various power ranges.

[0074] Specifically, the specific content of the PID control formula is as follows:

[0075]

[0076] Wherein, U(K) represents the working voltage of the TEC4; U min represents the minimum voltage of the TEC4, and participates in iteration as a fixed integral; e(k) is the error between the temperature value at the current moment and the target temperature value, and e(k-1) is the error at the last moment; K p is a proportional coefficient; K d is a differential coefficient; K i is an integral coefficient.

[0077] In addition, in order to reduce temperature oscillation, it often takes a long time to adjust the temperature to the target temperature for the above PID control formula, and if the integral link is enabled during the adjustment process, severe integral accumulation will be caused, and the temperature will easily exceed the possible limit control amount of the TEC4, causing overshoot and oscillation, and making the system difficult to stabilize. The integral itself is used to eliminate static error, so when the error value is relatively large, the integral action is cancelled (i.e. β=0), so as to prevent the adjustment stability from being reduced and the overshoot from being increased due to the integral action; when the controlled quantity approaches the target value (i.e. the error is small), the integral control (β=1) is introduced to eliminate the net error and improve the control precision.

[0078] In some embodiments, the controller 5 further comprises:

[0079] A light source calibration module is configured to count and store the driving voltage of the area light source 1 at different illumination nodes and the calibration value of the illumination sensor.

[0080] A second voltage adjustment module is configured to set the initial driving voltage of the area light source 1 as the driving voltage corresponding to the target illumination value, and adjust the driving voltage of the area light source 1 so that the current detection value of the illumination sensor is the calibration value corresponding to the target illumination value.

[0081] In addition, the controller 5 further comprises:

[0082] A calculation module is configured to obtain the target driving voltage and the target calibration value corresponding to the target illumination value by performing interpolation calculation on the driving voltage and the calibration value at two adjacent illumination nodes of the target illumination value.

[0083] In the actual working process, the process of adjusting the illumination of the light outlet 22 of the light shielding box by the controller 5 is as follows:

[0084] S1: Connect the controller 5 and the optical power meter to the upper computer.

[0085] S2: start the light source calibration program, divide the range of the light output port 22 of the light shielding box into several nodes, then adjust the driving voltage of the light source from low to high and read the corresponding illumination value of the external optical power meter and the detection value of the internal illumination sensor 6 of the device as the calibration value. The driving voltage, illumination value and calibration value at the above setting node are written into the light source calibration module in the controller 5 and saved.

[0086] S3: in the process of adjusting the illumination of the light output port 22 of the light shielding box, the target illumination value is sent to the controller 5, and the driving voltage and calibration value corresponding to the left and right two illumination value nodes of the target illumination value are extracted by the calculation module in the controller 5, and the corresponding driving voltage and calibration value are calculated by linear interpolation.

[0087] S4: after the controller 5 provides the driving voltage to the area light source 1, the current illumination value is collected by the illumination sensor 6, the calibration value obtained by linear interpolation in S3 is taken as the target calibration value, and the light source driving voltage is adjusted by the second voltage adjustment module to make the detection value of the illumination sensor 6 be the target calibration value, so that the illumination of the light output port 22 of the light shielding box is stabilized near the target illumination value.

[0088] In some embodiments, a plurality of illumination sensors 6 can be arranged at different positions in the light shielding box 2 to obtain a plurality of illumination values. Subsequently, the illumination sensor 6 with the optimal data stability can be selected as a reference, or the cumulative sum of the plurality of illumination values can be calculated by using different coefficients as the detection value corresponding to the node, thereby improving the accuracy of the illumination value collected by the illumination sensor 6.

[0089] Based on the above processing, the initial driving voltage provided by the utility model can make the illumination value of the light output port 22 of the light shielding box very close to the target illumination value, and can stabilize the illumination value in a very short time, greatly improving the efficiency of automatic testing.

[0090] From the above, the utility model provides a uniform light source device which can be applied to flat field correction, with temperature control equipment such as TEC4, which can prevent light source fluctuation caused by temperature fluctuation. In addition, the temperature of the light source and the illumination of the light output port 22 of the light shielding box can be controlled through the serial port of the controller 5, which meets the needs of different types of camera testing or flat field correction for uniform light source, and provides a fast and stable uniform light source with adjustable illumination of the light output port 22 of the light shielding box.

[0091] In the description of the specification, the description of the terms "one embodiment", "an example", "a specific example" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the utility model. In the specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0092] The basic principle, main features and advantages of the utility model are shown and described above. Those skilled in the art should understand that the utility model is not limited by the above embodiments, and the above embodiments and the description in the specification are only to illustrate the principle of the utility model, and various changes and improvements of the utility model can be made without departing from the spirit and scope of the utility model, and these changes and improvements all fall within the scope of the utility model claimed.

Claims

1. A uniform light source device for flat field correction, comprising a surface light source and a light blocking box for the light of the surface light source only, which is built-in with a plurality of baffle plates with through holes to remove light in non-light emitting directions, characterized in that, Also comprising: TEC, arranged inside or on the surface of the surface light source, for reducing the temperature of the light emitting part of the surface light source; Illuminance sensor, arranged in the light shielding box and not shielding any non-zero illuminance on the light emitting path, for indirectly judging the illuminance change of the light emitting port of the light shielding box; Controller, connected to the TEC control circuit and the light source driver, the controller controls the working voltage of the TEC and the driving voltage of the light source according to the illuminance change fed back by the illuminance sensor, so as to ensure that the illuminance of the light emitting port of the light shielding box is maintained stable.

2. The uniform light source apparatus according to claim 1, characterized by The surface light source is replaced by an integrating sphere light source, and the light emitting port of the integrating sphere light source is arranged at the light inlet port of the light shielding box; wherein the TEC is arranged inside or on the surface of the integrating sphere light source, for reducing the temperature of the light emitting part of the integrating sphere light source.

3. The uniform light source apparatus according to claim 1, wherein The TEC is arranged on the back surface of the light emitting part in the surface light source, or on the back surface of the PCB board in the surface light source, for directly reducing the temperature of the light emitting part.

4. The uniform light source arrangement according to any of claims 1 or 2, characterized in that, The TEC is replaced by one or any combination of water cooling equipment, air cooling equipment or compressor refrigeration equipment.

5. The uniform light source arrangement according to any of claims 1 or 2, characterized in that, Also comprising: One or any combination of water cooling equipment, air cooling equipment or compressor refrigeration equipment, which is connected to the light emitting part through a heat conduction medium or directly, or the refrigeration end of which is connected to the heat generating end of the TEC, and is used in combination with the TEC to reduce the temperature of the light emitting part.

6. The uniform source apparatus of any one of claims 1 or 2, wherein, The area where the illuminance sensor is arranged includes: the area on the baffle except the through hole, and the area on the inner wall of the light shielding box except the light emitting port and the light inlet port.

7. The uniform light source apparatus according to claim 1, wherein The illuminance sensor arranged in the light shielding box is replaced by an illuminance sensor arranged outside the light shielding box; wherein the arrangement area of the illuminance sensor includes one or more places in the surface light source and the measured camera.

8. The uniform light source apparatus according to claim 1, wherein The illuminance sensor arranged in the light shielding box is replaced by an illuminance sensor arranged outside the light shielding box, and the arrangement area of the illuminance sensor includes one or more places between the surface light source and the light shielding box, and between the measured camera and the light shielding box; wherein light shielding pieces are arranged on the gaps between the light shielding box and the surface light source, and between the light shielding box and the measured camera, for shielding ambient light, so that the detection value of the illuminance sensor and the illuminance of the light emitting port of the light shielding box have a calibrated corresponding relationship.

9. The uniform light source apparatus according to claim 1, wherein Also comprising: Uniform light plate, arranged on the surface of the light emitting part in the surface light source, between the surface light source and the light inlet port of the light shielding box, on the inner wall of both ends of the light shielding box or on the baffle, and completely covering any light emitting surface in the light emitting path.

10. The uniform source device of any of claims 1 or 2, wherein, The plurality of baffles are parallel to the light inlet port and the light emitting port of the light shielding box, and the light emitting port of the surface light source or the integrating sphere light source is coincided with the center axis of the light inlet port, the light emitting port and the through hole of the light shielding box.

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