Device for testing resolution of camera module

Abstract

The utility model discloses a device for testing the resolution of a camera module, and belongs to the technical field of camera modules. The device for testing the resolution of the camera module comprises a machine table, a host, a moving mechanism, a test graphic card and three-dimensional shooting equipment, the moving mechanism is arranged on the moving mechanism, and the test graphic card is connected to the moving mechanism; the three-dimensional shooting equipment is arranged on the machine table, and a lens of the three-dimensional shooting equipment faces the test graphic card so as to shoot image information of a plurality of markers on the test graphic card; the host is connected with the three-dimensional shooting device and the moving mechanism so as to obtain three-dimensional coordinates of the multiple markers based on the image information of the multiple markers, the three-dimensional coordinates are compared with preset coordinates to obtain the adjustment amount of the test graphic card, and then the moving mechanism is controlled to move the test graphic card based on the adjustment amount. The device for testing the resolution of the camera module provided by the utility model can improve the precision of the installation position of the test graphic card and improve the quality of the resolution test.

Description

Technical Field

[0001] The present application belongs to the field of camera module technology, and in particular, relates to a camera module resolution testing device. Background Art

[0002] Camera resolution is also called analytical power or resolution, which refers to the ability of the lens to distinguish image details. It reflects the clarity and sharpness of the image taken and is the main indicator for measuring the quality of shooting. In order to test the quality of the pictures taken by the camera, the resolution test chart is often used for testing.

[0003] There are two testing methods: First, use the projection or actual shooting of the black and white lines on the identification chart to calculate, usually expressed as a number of black and white parallel line pairs that can be distinguished within 1 mm, the unit is "line pair / mm", the more line pairs that can be distinguished in the film, the higher the resolution of the lens; second, shoot a radial or line resolution chart with absolute contrast to measure the resolution of the lens, which is to determine the diameter of the completely blurred center part on the film or to measure it according to the maximum number of lines that can be visually distinguished in each direction in each square on the film.

[0004] Among them, the accuracy and reliability of the resolution test are greatly affected by the centering accuracy of the resolution test chart and the distance to the lens. In addition, for lenses of different specifications or uses, the resolution test chart needs to be replaced or the distance to the lens needs to be adjusted. Therefore, the frequency of disassembly and assembly of the resolution test chart is relatively high, so the installation accuracy needs to be strictly controlled. However, the resolution test chart often needs to be installed manually, which is prone to centering deviation, which is not conducive to maintaining the quality of the resolution test. Summary of the invention

[0005] The present application provides a camera module resolution test device, which aims to at least to some extent solve the technical problem of poor accuracy and reliability of camera module resolution test.

[0006] The embodiment of the present application provides a camera module resolution test device, comprising: a machine platform, a host, a moving mechanism, a test chart, and a three-dimensional shooting device;

[0007] The mobile mechanism is arranged on the mobile mechanism, and the test chart is connected to the mobile mechanism;

[0008] The 3D shooting device is arranged on the machine platform, and the lens of the 3D shooting device faces the test chart to shoot image information of multiple markers on the test chart;

[0009] The host is connected to the three-dimensional shooting device and the moving mechanism to obtain the three-dimensional coordinates of the multiple markers based on the image information of the multiple markers, and compare them with the preset coordinates to obtain the adjustment amount of the test card, and then control the moving mechanism to move the test card based on the adjustment amount.

[0010] In some embodiments, the adjustment amount includes: a first movement amount along the optical axis direction of the 3D shooting device, a second movement amount and a third movement amount perpendicular to the optical axis direction of the 3D shooting device, and the directions of the second movement amount and the third movement amount are perpendicular.

[0011] In some embodiments, the number of the markers is five, which are respectively arranged in the center and four corners of the test chart.

[0012] In some embodiments, the test chart includes a chart and a back plate, the back plate is connected to the moving mechanism, and the chart is arranged on the back plate.

[0013] In some embodiments, the camera module resolution testing device further includes a flattener;

[0014] The flattener is connected to the back plate and flattens the picture card laid on the back plate.

[0015] In some embodiments, the picture card is a black and white grid.

[0016] In some embodiments, the moving mechanism includes a three-axis moving platform, and the test chart is connected to a moving part of the three-axis moving platform.

[0017] In some embodiments, the moving part of the three-axis moving platform can move along the optical axis direction of the 3D shooting device and a first direction and a second direction perpendicular to the optical axis direction of the 3D shooting device, and the first direction is perpendicular to the second direction.

[0018] In some embodiments, the three-dimensional shooting device includes: a test fixture and a ToF camera module;

[0019] The test fixture is arranged on the machine platform and connected to the host;

[0020] The ToF camera module can be detachably mounted on the test fixture to be connected to the host through the test fixture.

[0021] In some embodiments, the camera module resolution testing device further includes: a teleconverter, which is arranged between the three-dimensional shooting device and the test chart.

[0022] The embodiments of the present application have at least the following beneficial effects:

[0023] The camera module resolution test device provided in the embodiment of the present application sets a host and a test chart based on a machine, provides a background host and a photographed target for the lens resolution test of the camera module, and transmits the target image photographed by the camera module to be tested back to the host to complete the test image acquisition process. Further, a moving mechanism is set as a centering adjustment mechanism for the test chart, and the test chart is moved in three mutually perpendicular directions to meet the centering adjustment requirements of the test chart; and a three-dimensional shooting device is set to cooperate with the host to shoot the image information of multiple markers on the test chart and determine the three-dimensional coordinates of the multiple markers, so that the three-dimensional coordinates and the three-dimensional coordinates of the photographed multiple markers can be compared to obtain the adjustment amount of the test chart; the host can control the movement of the moving mechanism based on the adjustment amount to complete the centering adjustment of the test chart, ensure its centering accuracy, and thus improve the quality of the resolution test. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following is a brief introduction to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0025] Figure 1 The schematic diagram of the principle of the camera module resolution testing device in the embodiment of the present application is shown;

[0026] Figure 2 Shows Figure 1 A schematic diagram of the structure of a test chart of a camera module resolution test device;

[0027] Figure 3 Shows Figure 1 The principle block diagram of the camera module resolution test device.

[0028] Reference numerals:

[0029] 100-test chart, 110-marker, 200-moving mechanism, 300-3D shooting equipment, 310-test fixture, 320-ToF camera module, 400-machine, 500-host. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0031] In addition, the present application may repeat reference numbers and / or reference letters in different examples, and such repetition is for the purpose of simplicity and clarity, and does not in itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present application provides various specific examples of processes and materials, but those of ordinary skill in the art may recognize the application of other processes and / or the use of other materials.

[0032] The present application is described below with reference to the accompanying drawings and specific embodiments:

[0033] In the camera resolution test, it is necessary to imagine shooting a preset test chart, and then evaluate the camera resolution based on the lines or area features of the captured image. According to the purpose and specifications of the camera, the type of the test chart, the centering position, the distance to the camera, etc. also need to be adjusted accordingly. Therefore, the centering accuracy after adjustment needs to be guaranteed.

[0034] However, when actually replacing the test chart, adjusting the centering position and distance often requires the operator to perform manual operations based on the collimator. In particular, when the distance from the camera to the test chart is small, the error of the adjustment operation is large, which directly affects the quality and reliability of the camera resolution test.

[0035] To this end, an embodiment of the present application provides a camera module resolution test device to improve the accuracy and reliability of the centering adjustment operation of the test chart, thereby maintaining the resolution test quality of the camera.

[0036] Figure 1 The schematic diagram of the principle of the camera module resolution testing device in the embodiment of the present application is shown; Figure 2 Shows Figure 1 A schematic diagram of the structure of a test chart of a camera module resolution test device; Figure 3 Shows Figure 1 The principle block diagram of the camera module resolution test device.

[0037] See also Figure 1 , Figure 2 and Figure 3 The camera module resolution testing device includes: a machine platform 400, a host 500, a test chart 100, a moving mechanism 200 and a three-dimensional shooting device 300.

[0038] The platform 400 is used as an installation base to carry the above-mentioned components, and a matching installation structure should be provided thereon to install and fix the test chart 100 , the moving mechanism 200 and the 3D shooting device 300 .

[0039] The test chart 100, as a photographic target for the resolution test, can be connected to the moving part of the moving mechanism 200, so that the test chart 100 can be moved by operating the moving mechanism 200 to achieve the centering adjustment of the test chart 100. In addition, a plurality of markers 110 can be provided on the test chart 100 to locate the spatial position of the test chart 100, so as to facilitate the movement of the test chart 100.

[0040] The host 500 serves as a background host, connected to the mobile mechanism 200 and the three-dimensional shooting device 300, and is used to receive and store image information of the test chart 100 shot by the camera to be tested, and to control the movement of the mobile mechanism 200.

[0041] The three-dimensional shooting device 300 is installed on the machine platform 400 and connected to the host 500 to shoot the markers 110 on the test chart 100 and realize positioning, obtain the three-dimensional coordinates of the multiple markers, that is, realize the spatial positioning of the test chart 100. The host 500 can be set with a preset standard position of the test chart 100, and correspondingly, the multiple markers 110 should also have preset standard coordinates, so that they can be compared with the measured spatial coordinates of the multiple markers 110 to obtain the corresponding adjustment amount, so that the host 500 can control the moving mechanism 200 to move based on the adjustment amount to adjust the position of the test chart 100.

[0042] That is to say, the host 500 and the test chart 100 cooperate to form a system framework for the resolution test, and then the camera to be tested is connected to the host 500, and the test chart 100 is photographed, and then the photographed image data is sent back to the host 500 as the basic data for the resolution analysis of the camera to be tested. Further, on this basis, the mobile mechanism 200 and the three-dimensional shooting device 300 are set up and connected to the host 500, and the spatial positioning of the multiple markers 110 on the test chart 100 is realized through the three-dimensional shooting device 300, and the measured three-dimensional coordinates are obtained, and then the host 500 compares the measured three-dimensional coordinates with the preset coordinates to obtain the adjustment amount of the test chart 100 and control the movement of the mobile mechanism 200, so as to realize the automatic adjustment of the position of the test chart 100. Thus, a resolution test device capable of automatically adjusting the test chart 100 is obtained to maintain the reliability and quality of the test.

[0043] In some embodiments, considering that in the camera resolution test, the parameters such as the alignment and distance between the test chart 100 and the camera vary greatly, the moving direction of the moving mechanism 200 can be set to three mutually perpendicular directions based on the optical axis direction of the three-dimensional shooting device 300.

[0044] Specifically, the adjustment amount of the moving mechanism is divided into a first movement amount, a second movement amount and a third movement amount in three mutually perpendicular directions.

[0045] Among them, the first movement amount can be set to the movement amount along the optical axis direction of the three-dimensional shooting device, the second movement amount and the third movement amount are the movement amounts in two directions perpendicular to the optical axis of the three-dimensional shooting device, and the directions of the second movement amount and the third movement amount are perpendicular to each other; forming an adjustment system similar to a three-dimensional coordinate system to avoid mutual interference between the movement operations in the three directions.

[0046] In some embodiments, the moving mechanism 200 can be set as a three-axis moving platform that can move in three mutually perpendicular directions, and the test chart 100 can be set on the moving part of the three-axis moving platform to cooperate in realizing the movement of the test chart 100 in three mutually perpendicular directions.

[0047] The three mutually perpendicular directions may be set as directions corresponding to the first movement amount, the second movement amount and the third movement amount.

[0048] In some embodiments, the three-axis mobile platform can be composed of three sets of drive mechanisms based on the screw principle, which are arranged on the machine 400, and the driving directions of the three sets of drive mechanisms based on the screw principle are respectively along the above three mutually perpendicular directions.

[0049] Among them, the driving mechanism of the screw principle includes a basic bracket, a screw, a nut and a driving motor. The screw can be rotatably arranged on the basic bracket around its axis, the driving motor is connected to the screw, the nut is screwed on the screw, and the nut can be slidably arranged on the basic bracket along the axis direction of the screw, so that the driving motor can be rotated forward and reversely to drive the nut to reciprocate in the axial direction of the screw for position adjustment.

[0050] A platform base may be provided on the nut to install a basic bracket of other driving mechanisms or to install the test chart 100 to achieve the position of the test chart 100.

[0051] In some embodiments, the marker 110 may be configured as a dotted graphic, or other graphic with identifiable features, to facilitate accurate positioning.

[0052] Alternatively, the marker 110 may be set to a striking color such as red for differentiation.

[0053] In some embodiments, the marker 110 may be disposed at the center of the test chart 100 to achieve centering positioning. The marker 110 may also be disposed at two or more other positions of the test chart 110 to reduce the positioning error of the test chart 100 by multi-point positioning.

[0054] In some embodiments, the test chart 110 can be set to a regular shape such as a rectangle or a square, so as to measure the black and white line pairs, the area of ​​the blurred center part, and other characteristics of the analysis and characterization of the resolution.

[0055] In some embodiments, the test chart 110 may be configured as a black and white grid plate, so as to characterize the resolution by measuring the number of black and white grids.

[0056] In some embodiments, in order to facilitate replacement, the test chart 110 may include a back plate and a chart, wherein the chart can be set as a test pattern, and the back plate serves as a laying board for stably supporting the unfolded chart, suppressing defects such as wrinkles and undulations on the chart, and improving the flatness to improve the quality of the captured image, thereby improving the reliability of the resolution test.

[0057] In some embodiments, a flattener may be further provided on the back plate to stably flatten the chart card on the back plate, thereby maintaining the flat state of the chart card and reducing adverse effects on the resolution test.

[0058] Generally speaking, a vacuum flattener or a mechanical flattener can be used.

[0059] In some embodiments, the three-dimensional shooting device 300 may include a test fixture 310 and a ToF camera module 320. The test fixture 310 can be used as a connecting base to communicate with the host 500; when the test chart 100 is calibrated, it is used to install the ToF camera module 320 and communicate with the host 500.

[0060] Therefore, the test fixture 310 can be used as a common part, and when performing resolution testing, it can be used as a mounting seat for the camera to be tested and communicated with the host 500, which can simplify the scale of the test device to a certain extent.

[0061] In some embodiments, considering that some cameras require a longer test shooting distance, a teleconverter can be provided on the machine 400 and disposed between the test camera or the three-dimensional shooting device 300 and the test chart 100, so as to extend the shooting distance to a certain extent and meet the test requirements.

[0062] For example, when testing a lens with a focal length of less than 150 mm, the test chart 100 should be photographed at a distance that is more than 30 times greater than the focal length of the lens.

[0063] The embodiments of the present application have at least the following beneficial effects:

[0064] The camera module resolution test device provided in the embodiment of the present application sets a host and a test chart based on a machine, provides a background host and a photographed target for the lens resolution test of the camera module, and transmits the target image photographed by the camera module to be tested back to the host to complete the test image acquisition process. Further, a moving mechanism is set as a centering adjustment mechanism for the test chart, and the test chart is moved in three mutually perpendicular directions to meet the centering adjustment requirements of the test chart; and a three-dimensional shooting device is set to cooperate with the host to shoot the image information of multiple markers on the test chart and determine the three-dimensional coordinates of the multiple markers, so that the three-dimensional coordinates and the three-dimensional coordinates of the photographed multiple markers can be compared to obtain the adjustment amount of the test chart; the host can control the movement of the moving mechanism based on the adjustment amount to complete the centering adjustment of the test chart, ensure its centering accuracy, and thus improve the quality of the resolution test.

[0065] In the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0066] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise" and "counterclockwise" indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0067] It should be noted that all directional indications in the embodiments of the present application are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0068] In this application, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0069] In addition, the descriptions of "first", "second", etc. in this application are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0070] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification.

[0071] In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the fact that they can be implemented by ordinary technicians in this field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0072] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the claims and their equivalents.

Claims

1. A camera module resolution test device, characterized in that: include: Machine, host, mobile mechanism, test chart and 3D shooting equipment; The mobile mechanism is arranged on the mobile mechanism, and the test chart is connected to the mobile mechanism; The 3D shooting device is arranged on the machine platform, and the lens of the 3D shooting device faces the test chart to shoot image information of multiple markers on the test chart; The host is connected to the three-dimensional shooting device and the moving mechanism to obtain the three-dimensional coordinates of the multiple markers based on the image information of the multiple markers, and compare them with the preset coordinates to obtain the adjustment amount of the test card, and then control the moving mechanism to move the test card based on the adjustment amount.

2. The camera module resolution testing device according to claim 1, characterized in that: The adjustment amount includes: a first movement amount along the optical axis direction of the 3D shooting device, a second movement amount and a third movement amount perpendicular to the optical axis direction of the 3D shooting device, and the directions of the second movement amount and the third movement amount are perpendicular.

3. The camera module resolution testing device according to claim 1, characterized in that: The number of the markers is five, which are respectively arranged at the center and four corners of the test chart.

4. The camera module resolution testing device according to claim 1, characterized in that: The test chart includes a chart and a back plate, wherein the back plate is connected to the moving mechanism and the chart is arranged on the back plate.

5. The camera module resolution testing device according to claim 4, characterized in that: The camera module resolution testing device also includes a flattener; The flattener is connected to the back plate and flattens the picture card laid on the back plate.

6. The camera module resolution testing device according to claim 4, characterized in that: The picture card is a black and white grid plate.

7. The camera module resolution testing device according to claim 1, characterized in that: The moving mechanism comprises a three-axis moving platform, and the test chart is connected to the moving part of the three-axis moving platform.

8. The camera module resolution testing device according to claim 7, characterized in that: The moving part of the three-axis moving platform can move along the optical axis direction of the 3D shooting device and a first direction and a second direction perpendicular to the optical axis direction of the 3D shooting device, and the first direction is perpendicular to the second direction.

9. The camera module resolution testing device according to claim 1, characterized in that: The three-dimensional shooting device includes: a test fixture and a ToF camera module; The test fixture is arranged on the machine platform and connected to the host; The ToF camera module can be detachably mounted on the test fixture to be connected to the host through the test fixture.

10. The camera module resolution testing device according to claim 1, characterized in that: The camera module resolution testing device also includes: a teleconverter, which is arranged between the three-dimensional shooting device and the test chart.

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