Automatic batch testing device for image performance of microscopic camera

Abstract

The utility model discloses an automatic batch testing device for microscopic camera image performance, which comprises a sealed cabin body (10), a cabin cover (20) connected with the sealed cabin body (10) and a light source controller (30), the sealed cabin body (10) is provided with at least two light source parts (40) electrically connected with the light source controller (30), the sealed cabin body (10) and the cabin cover (20) isolate the internal space into at least two light source chambers (11), and the sealed cabin body (10) is provided with at least two light source parts (40) electrically connected with the light source controller (30). The at least two light source parts (40) are respectively arranged in the at least two light source chambers (11), the hatch cover (20) is provided with light outlets (21) at positions corresponding to the light source parts (40), and the light outlets (21) are connected with crimping assemblies (50) used for being connected with a tested camera. According to the automatic batch testing device for the image performance of the microscopic camera, the size of the testing device is greatly reduced, the structure is simple, the cost is low, a plurality of cameras can be measured at the same time, and the automatic batch testing device is a standardized testing device which can be used in a camera production line and a research and development laboratory.

Description

Technical Field

[0001] The utility model relates to the technical field of image sensors and camera testing, in particular to an automatic batch testing device for microscope camera image performance. Background Art

[0002] The image performance of a camera refers to a series of parameters such as conversion gain, read noise, full well charge, dark current, signal-to-noise ratio, dynamic range and linearity. The European Machine Vision Association has developed the EMVA1288 (European Machine Vision Association 1288) standard for the above performance tests of image sensors and cameras. It is an electronic standard that aims to characterize the performance of industrial camera sensors through scientific methods. This standard provides test parameters and equipment for generating EMVA 1288 reports and defines methods for evaluating image performance between different cameras. It is currently the only international standard recognized by the machine vision industry and is recognized and adopted by all major image sensor and camera manufacturers in the world.

[0003] The China Machine Vision Industry Union (CMVU) officially released the Chinese version of the standard in October 2017 and began to vigorously promote the standard in China. At the same time, it is also working hard to apply for the standard to be upgraded to a national standard, hoping to guide domestic camera manufacturers and users with standardized testing methods, and improve the overall level of research and development, production and application of domestic image sensors and cameras. Domestic related units have developed some image sensor and camera performance test platforms based on the EMVA1288 standard, such as the camera performance test device based on the EMVA1288 standard with a publication number of CN 108848375 A, which is mainly composed of LED flat panel light source, cylindrical light path, aperture, camera adapter ring and camera darkroom. The compact structure enables the entire test device to be implemented in the form of a portable instrument. Combined with the supporting computer software, it can automatically complete the full set of EMVA1288 parameter tests.

[0004] The test device in the prior art has a complex structure and is difficult to test multiple or batches at the same time; multiple separate tests will cause variable interference and lead to inaccurate test evaluation results. In addition, the test methods and evaluation standards of different manufacturers are not completely consistent, so it is impossible to compare the performance of sensors from different manufacturers. A unified test method is needed to test the chip. Utility Model Content

[0005] The utility model aims to provide an automated batch testing device for the image performance of a microscope camera, which has a small size, a simple structure, can measure multiple cameras at the same time, and is a standardized testing device that can be used in camera production lines and R&D laboratories.

[0006] In order to solve the above problems, the specific technical solutions adopted by the utility model are as follows:

[0007] An automated batch testing device for image performance of a microscope camera comprises a sealed cabin, a cabin cover connected thereto and a light source controller, the sealed cabin being provided with at least two light source components both electrically connected to the light source controller, the sealed cabin and the cabin cover isolating an internal space into at least two light source chambers, the at least two light source components are respectively arranged in the at least two light source chambers, the cabin cover is provided with a light outlet at a position corresponding to each light source component, the light outlet is connected with a crimping assembly for connecting to a camera under test.

[0008] Furthermore, the light outlet is arranged in a coaxial direction of the light source component, and the light source controller is provided with a first interface which can be connected to a host computer.

[0009] Furthermore, the light source controller is provided with a second interface which can be connected to an adapter for power supply.

[0010] Furthermore, the crimping assembly includes a clamping member and a connecting member, both of which are tubular structures, wherein the two ends of the connecting member are respectively connected to the light outlet and the camera under test, and the clamping member is sleeved on the outside of the connecting member and the light outlet, and the central axis of the connecting member is perpendicular to the light-emitting surface of the light source.

[0011] Furthermore, the crimping assembly includes a port sleeve of a tubular structure connected to the light outlet, the port sleeve is detachably connected to one end of a connecting piece, the connecting piece has a clamping platform extending outward, the clamping piece has a clamping platform extending inward that abuts against the clamping platform, and the clamping piece is detachably connected to the port sleeve.

[0012] Furthermore, the port kit is provided with a first positioning groove, and the connecting piece is provided with a positioning platform inserted in the first positioning groove.

[0013] Furthermore, a limiting groove is provided beside the light outlet, and a limiting platform plugged into the limiting groove is provided on the outlet kit.

[0014] Furthermore, the sealed cabin body includes a cabin body and a cabin bottom connected thereto, the cabin body is provided with at least two light source openings, the light source openings, the cabin bottom and the cabin cover together form the light source room, the light source component is an LED ring light source, and the light outlet diameter is smaller than the diameter of the LED ring light source.

[0015] Furthermore, a second positioning groove is provided in the light source chamber, and the light source component is inserted into the second positioning groove.

[0016] Furthermore, the cabin body is provided with a line opening, the cabin cover is provided with a line hole corresponding to the line opening, the cabin cover is provided with a first reinforcing rib surrounding the light outlet and the line opening, and the cabin bottom is provided with a criss-crossing second reinforcing rib.

[0017] Compared with the large darkroom structure used in the prior art, the beneficial effect of the utility model is that the volume of the test device is greatly reduced, the structure is simple, the cost is low, and multiple cameras can be measured simultaneously, avoiding the problem of variable interference caused by multiple tests and resulting in inaccurate test evaluation results.

[0018] The testing device provided by the utility model is a standardized testing device used in a camera production line and a research and development laboratory.

[0019] The test device provided by the utility model can be used in accordance with the requirements of the EMVA1288 standard for the test light source, and can cooperate with the LED ring light source and the test software designed according to the EMVA1288 standard algorithm to quickly and efficiently complete the full set of EMVA1288 standard parameter tests automatically; the test software can adjust the intensity and brightness of the light source to ensure that the illumination uniformity of the sensor of the camera under test reaches the requirement of better than 98%. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present utility model;

[0022] Figure 2 This is a schematic diagram of the bottom structure of Example 1 of the utility model;

[0023] Figure 3 This is a bottom schematic diagram of Example 1 of the utility model with the cabin bottom and a light source component hidden;

[0024] Figure 4 It is a partial schematic diagram of Example 1 of the utility model with the hatch cover hidden;

[0025] Figure 5 It is a cross-sectional schematic diagram of Embodiment 1 of the present utility model;

[0026] Figure 6 This is a schematic diagram of the structure of Embodiment 2 of the present utility model;

[0027] In the figure: a sealed cabin 10, a light source chamber 11, a cabin body 12, a cabin bottom 13, a hatch 20, a light outlet 21, a light source controller 30, a first interface 31, a second interface 32, a light source component 40, a power cord 41, a crimping assembly 50, a clamping member 51, a connector 52, a port kit 53, a camera under test 60, a pressing platform 511, a first positioning groove 531, a card platform 521, a positioning platform 522, a plug-in groove 523, a limit groove 211, a limit platform 532, a second positioning groove 111, a light source opening 121, a line-accommodating opening 122, an embedding groove 124, a first reinforcing rib 201, a second reinforcing rib 131, and a screw 70. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field through simple deformation should fall within the scope of protection of the utility model.

[0029] The meanings of the terms involved in the utility model are explained as follows: Conversion gain: Electrons are converted into digital signals according to a certain conversion coefficient through an analog-to-digital converter (ADC). This conversion coefficient is called conversion gain (Gain). Readout noise: In the readout process, the noise generated when electrons produce images through analog-to-digital conversion, amplification and processing is called readout noise. Full well charge: Electrons are stored in each pixel and converted into electric charge. The amount of light falling on each pixel can be displayed by measuring the charge. The maximum charge is called the full well charge. Dark current: In addition to electrons generated by incident light, heat generated by the silicon lattice inside the camera sensor can also generate electrons, which is the dark current. Signal-to-noise ratio: The signal-to-noise ratio of a camera is defined as the ratio of the signal to the noise in the image, which represents the quality of the image. Dynamic range: The dynamic range is the ratio of the signal in the saturated state to the lowest signal that the sensor can measure. The dynamic range indicates the ability of the camera to display the brightest and darkest parts of the image and the degree of change between the two. Linearity: Linearity is an important indicator to describe the static characteristics of the sensor, and it is based on the premise that the measured input quantity is in a stable state. Under specified conditions, the maximum deviation (ΔYmax) between the sensor calibration curve and the fitting straight line and the percentage of the full-scale output (Y) is called linearity (linearity is also called "non-linear error"). The smaller the value, the better the linear characteristics.

[0030] Example 1

[0031] like Figure 1-Figure 4As shown, the automated batch testing device for the image performance of a microscope camera provided by Example 1 of the utility model comprises a sealed cabin 10, a hatch 20 connected thereto, and a light source controller 30, wherein the light source controller 30 is provided with a first interface 31 that can be connected to a host computer, the sealed cabin 10 and the hatch 20 isolate the internal space into five light source chambers 11, the sealed cabin 10 is provided with five light source components 40 that are electrically connected to the light source controller 30, the five light source components 40 are respectively arranged in the five light source chambers 11, and the light source controller 30 is provided with a second interface 32 that can be connected to an adapter for power supply. The hatch 20 is provided with a light outlet 21 at a position corresponding to each light source component 40, the light outlet 21 is arranged in the coaxial direction of the light source component 40, and the light outlet 21 is connected to a crimping assembly 50 for connecting to a camera 60 to be tested.

[0032] In one implementation, Figure 3 As shown, the light source 40 is preferably an LED ring light source, which is a monochromatic light source, and the diameter of the light outlet 21 is smaller than the diameter of the LED ring light source.

[0033] In one implementation, the light source controller 30 has a total of seven interfaces, five interfaces on one side are respectively connected to the power lines 41 of the five LED ring light sources, and the first interface 31 on the other side (preferably a USB2.0 interface) is connected to the host computer via a data cable to power the ring light source. The test software designed according to the EMVA1288 standard algorithm runs on the host computer, and the brightness of the LED ring light source is adjusted by operating the test software; the second interface 32 is a backup power supply interface. When the voltage of the first interface 31 is insufficient, the second interface 32 can be connected to a 5V adapter for power supply, and the adapter power can be increased according to the number of light sources 40.

[0034] In one implementation, Figure 5 As shown, the crimping assembly 50 includes a clamping member 51 and a connecting member 52, both of which are tubular structures. The two ends of the connecting member 52 are connected to the light outlet 21 and the camera 60 under test, respectively. The clamping member 51 is sleeved on the outside of the connecting member 52 and the light outlet 21, so that the connecting member 52, the light outlet 21 and the camera 60 under test are tightly matched and fixed. The central axis of the connecting member 52 is perpendicular to the light-emitting surface of the light source member 40, and the light-emitting surface of the light source member 40 and the light outlet 21 are preferably circular, and the light-emitting surface and the light outlet 21 are arranged parallel to each other, and the dots of the two are on the central axis of the connecting member 52. At this time, the sealed cabin 10, the LED ring light source, the cabin cover 20, the light outlet 21, the clamping member 51, the connecting member 52 and the camera 60 under test form a closed light path, forming a darkroom that is not disturbed by external light. It is known to those skilled in the art that the connection between the connector 52 and the light outlet 21 can be achieved by threaded connection, snap-on connection, interference fit, magnetic connection, etc., all of which can achieve the purpose of detachable connection.

[0035] In one implementation, the crimping assembly 50 includes a mouth sleeve 53 of a tubular structure, which is fixedly connected to the edge of the light outlet 21 by a screw 70. The mouth sleeve 53 is plugged into one end of the connector 52, and can also be connected by a threaded connection or a snap-on connection, etc. The camera 60 under test and the other end of the connector 52 are threadedly connected or snap-connected, and the connector 52 has a card platform 521 extending outward, and the clamping member 51 has a pressure platform 511 extending inward that abuts against the card platform 521, and the mouth sleeve 53 is threadedly connected to the clamping member 51 so that the pressure platform 511 squeezes the card platform 521 toward the mouth sleeve 53, thereby fixing the camera 60 under test on the light outlet 21.

[0036] In one implementation, the mouthpiece 53 is provided with a first positioning groove 531, and the connector 52 is provided with a positioning platform 522 inserted into the first positioning groove 531, so that the fixation is more stable and the positioning is faster. A limit groove 211 is provided next to the light outlet 21, and a limit platform 532 is provided on the mouthpiece 53 to be inserted into the limit groove 211, so as to facilitate the subsequent positioning and fixing of the screw 70 hole. A second positioning groove 111 is provided in the light source chamber 11, and the light source component 40 is inserted into the second positioning groove 111, so as to facilitate the positioning of the light source component 40 in a position that meets the standard requirements. The connector 52 is provided with a circle of plug-in grooves 523, which are used to be plugged in or threaded or clamped with the camera 60 under test.

[0037] In one implementation, the sealed cabin body 10 includes a cabin body 12 and a cabin bottom 13 connected thereto. The cabin body 12 is provided with a circle of embedding grooves 124 for the cabin cover 20 to be embedded therein, which is convenient for fixing with screws 70 and also better isolates external light. The cabin body 12 is provided with 5 light source openings 121. The light source openings 121, the cabin bottom 13 and the cabin cover 20 together form a light source chamber 11.

[0038] In one implementation, the cabin body 12 is provided with a cable opening 122 for accommodating the power cable 41 of the LED ring light source, the cabin cover 20 is provided with a cable hole corresponding to the cable opening 122, the power cable 41 of the LED ring light source is connected to the light source controller 30 through the cable hole, the cabin cover 20 is provided with a first reinforcing rib 201 surrounding the light outlet 21 and the cable opening 122, and the cabin bottom 13 is provided with a crisscross second reinforcing rib 131. Further stabilize the overall test device.

[0039] The automated batch test device for the image performance of the microscope camera provided in this embodiment can be used with the test software running on the host computer to adjust the brightness of the LED ring light source and test the image performance: start to obtain the camera parameters, automatically test according to the EMVA1288 standard, and after the test, a lot of image performance data can be obtained, such as conversion gain, readout noise, full well charge, dark current, signal-to-noise ratio, dynamic range, linearity and other parameters, and generate a test report after the test. The test process is a standard prior art, which is briefly summarized as follows:

[0040] Conversion gain According to the EMVA1288 standard, take a black image with a short exposure time to calculate the offset; take two pictures with average brightness to calculate the average grayscale value mean of the two pictures; subtract the two pictures to get the difference image, and calculate the standard deviation std of the difference image; finally, according to the formula Gain = (mean-offset) / (std 2 / 2) to obtain the conversion gain.

[0041] The read noise is calculated according to the EMVA1288 standard by taking a single dark field short exposure image and calculating the standard deviation std. The read noise is obtained according to the formula Read Noise = std*Gain.

[0042] The full well charge is calculated according to the EMVA1288 standard by taking a single image with the maximum exposure time to calculate the average gray value mean, and the full well charge is obtained according to the formula Full Well = (mean-offset)*Gain.

[0043] Dark current is calculated according to the EMVA1288 standard. A long exposure image and a short exposure image are taken to obtain the difference in average grayscale values ​​of the two images, and the time difference between the long exposure and the short exposure is recorded as t. The dark current is obtained according to the formula Dark Noise = mean / t*Gain.

[0044] The signal-to-noise ratio was obtained according to the EMVA1288 standard using the formula SNR=20log10(SQRT(Full Well)).

[0045] The dynamic range is obtained according to the EMVA1288 standard and the formula Dynamic Range = 20log10 (Full Well / Dark Noise).

[0046] The linearity is calculated according to the EMVA1288 standard. The light source intensity is fixed, the exposure time is increased proportionally, the camera grayscale value at each exposure time is recorded, and the linearity of the camera is calculated.

[0047] Example 2

[0048] like Figure 6 As shown, this embodiment is the same as embodiment 1 in other respects, except that the sealed cabin body 10 and the cabin cover 20 isolate the internal space into two light source chambers 11, and the sealed cabin body 10 is provided with two light source components 40 electrically connected to the light source controller 30, and the two light source components 40 are respectively arranged in the two light source chambers 11.

[0049] In one implementation, the hull 12 and the bottom 13 are integrally formed, which is convenient for installation and has good stability.

[0050] In one implementation, the mouthpiece 53 and the connector 52 are snap-connected.

[0051] Example 3

[0052] This embodiment is the same as Embodiment 1 in other respects, except that the sealed cabin body 10 and the cabin cover 20 isolate the internal space into 10 light source chambers 11, and the sealed cabin body 10 is provided with 10 light source components 40 which are electrically connected to the light source controller 30, and the 10 light source components 40 are respectively arranged in the 10 light source chambers 11.

[0053] In one implementation, the ten light source chambers 11 are arranged in two rows of 5*2 to save more space.

[0054] In one implementation, the port kit 53 and the hatch cover 20 are integrally formed to reduce assembly steps.

[0055] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0056] Each embodiment in this specification is described in a related manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment. The above is only a preferred embodiment of the utility model and is not intended to limit the scope of protection of the utility model. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the utility model are included in the scope of protection of the utility model.

Claims

1. An automated batch testing device for image performance of a microscope camera, comprising a sealed cabin (10), a cabin cover (20) connected thereto, and a light source controller (30), characterized in that: The sealed cabin (10) is provided with at least two light source components (40) both electrically connected to a light source controller (30); the sealed cabin (10) and the cabin cover (20) isolate the internal space into at least two light source chambers (11); the at least two light source components (40) are respectively arranged in the at least two light source chambers (11); the cabin cover (20) is provided with a light outlet (21) at a position corresponding to each light source component (40); the light outlet (21) is connected to a crimping assembly (50) for connecting to a camera to be tested.

2. The automated batch testing device for microscope image performance according to claim 1, characterized in that: The light outlet (21) is arranged in a coaxial direction of the light source component (40), and the light source controller (30) is provided with a first interface (31) that can be connected to a host computer.

3. The automated batch testing device for microscope image performance according to claim 1, characterized in that: The light source controller (30) is provided with a second interface (32) which can be connected to an adapter for power supply.

4. The automated batch testing device for microscope image performance according to any one of claims 1 to 3, characterized in that: The crimping assembly (50) comprises a clamping member (51) and a connecting member (52) both of which are tubular structures, the two ends of the connecting member (52) being respectively connected to a light outlet (21) and a camera (60) to be tested, the clamping member (51) being sleeved on the outside of the connecting member (52) and the light outlet (21), and the central axis of the connecting member (52) being perpendicular to the light emitting surface of the light source member (40).

5. The automated batch testing device for microscope image performance according to claim 4, characterized in that: The crimping assembly (50) comprises a port sleeve (53) of a tubular structure connected to the light outlet (21); the port sleeve (53) is detachably connected to one end of a connecting member (52); the connecting member (52) has a clamping platform (521) extending outward; the pressing member (51) has a pressing platform (511) extending inward and abutting against the clamping platform (521); and the pressing member (51) is detachably connected to the port sleeve (53).

6. The automated batch testing device for microscope image performance according to claim 5, characterized in that: The port set (53) is provided with a first positioning groove (531), and the connecting piece (52) is provided with a positioning platform (522) inserted into the first positioning groove (531).

7. The automated batch testing device for microscope image performance according to claim 5 or 6, characterized in that: A limiting groove (211) is provided beside the light outlet (21), and a limiting platform (532) plugged into the limiting groove (211) is provided on the outlet sleeve (53).

8. The automated batch testing device for microscope image performance according to claim 3, characterized in that: The sealed cabin (10) comprises a cabin body (12) and a cabin bottom (13) connected thereto, the cabin body (12) being provided with at least two light source openings (121), the light source openings (121), the cabin bottom (13) and the cabin cover (20) together forming the light source chamber (11), the light source component (40) being an LED ring light source, and the diameter of the light outlet (21) being smaller than the diameter of the LED ring light source.

9. The automated batch testing device for microscope image performance according to claim 8, characterized in that: The cabin body (12) is provided with a line opening (122), the cabin cover (20) is provided with a line hole corresponding to the line opening (122), the cabin cover (20) is provided with a first reinforcing rib (201) surrounding the light outlet (21) and the line opening (122), and the cabin bottom (13) is provided with a crisscross second reinforcing rib (131).

10. The automated batch testing device for microscope image performance according to claim 1 or 2 or 3 or 5 or 6 or 8 or 9, characterized in that: A second positioning groove (111) is provided in the light source chamber (11), and the light source component (40) is inserted into the second positioning groove (111).

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