Centering method and device for medical electronic endoscope lens module

Abstract

The invention relates to the technical field of optics, and discloses a centering method and device for a medical electronic endoscope lens module, and the centering method sequentially comprises the following steps: S1, adjusting a laser collimator to be parallel to a horizontal base plane; s2, the plane where the beam splitter prism is located is adjusted to be parallel to the horizontal base plane; s3, using a beam splitter prism to simultaneously correct the plane where the test card and the sensor are located; and S4, adjusting the lens and the sensor to be centered, and gluing and curing the lens and the sensor. Centering correction of the test card and the sensor is carried out by adopting the beam splitter prism and the laser collimator through optical calibration, the alignment precision is improved through optical level alignment, only the degree of freedom of the lens needs to be adjusted after the test card and the sensor are centered and fixed, and the adjustment steps are reduced. The optimal imaging quality is achieved by collecting the imaging quality of the test card and finely adjusting the degree of freedom of the lens to replace the numerical value of the test card observed by human eyes, the lens modules are rapidly and efficiently assembled in batches, the assembly qualification rate is high, and the precision stability and consistency of the modules are improved.

Description

Technical Field

[0001] The present invention relates to the field of optical technology, and in particular to a centering method and device for a medical electronic endoscope lens module. Background Art

[0002] During the lens installation, after the optical lens and the lens housing are aligned and assembled, the centering accuracy must also be ensured. Centering accuracy is a crucial parameter indicator in the installation of optical lenses, which characterizes the consistency of the optical axes of the optical lens. Due to the existence of the matching clearance, the optical axis of each optical lens will have a center deviation of translation, tilt, or both relative to the reference axis. The center deviation of the lens will directly affect the centering accuracy, destroy the coaxiality and symmetry of the optical system, and the center deviation will cause aberrations in the optical system, and even seriously affect the optical quality of the system. After the optical lens barrel is aligned and assembled, the lens and the sensor are aligned and assembled. At this time, the lens and the sensor are in a free state. The relative position of the lens and the sensor is adjusted by analyzing the test card data of the lens imaging. After that, the complete lens module is encapsulated by curing the glue.

[0003] Many domestic companies mainly rely on experienced technicians to manually operate the lens assembly and adjustment test, assisted by relevant optical testing instruments and manual translation stages. This requires extremely high experience from the operators. Assembly process parameters such as assembly position and assembly alignment accuracy can only be completed through the cooperation of human eyes and hands. Human subjective factors have a great influence on the assembly and adjustment process, which will cause problems such as low optical lens assembly accuracy and one-time assembly pass rate, poor accuracy stability and consistency. Summary of the invention

[0004] In order to overcome or alleviate one or more of the above technical problems, the purpose of the present invention is to provide a method and device for centering a medical electronic endoscope lens module. After the centering device is assembled, batches of medical electronic endoscope lens modules (sensors and lenses) can be quickly and efficiently centered or tested, thereby greatly improving the assembly efficiency of the module.

[0005] The present invention provides the following technical solutions:

[0006] In a first aspect, the present invention provides a centering method for a medical electronic endoscope lens module, comprising the following steps in sequence:

[0007] S1: Adjust the laser collimator to be parallel to the horizontal base plane;

[0008] S2: Adjust the plane where the beam splitter prism is located to be parallel to the horizontal base plane;

[0009] S3: using a beam splitter prism to simultaneously calibrate the planes where the test card and the sensor are located, the laser beam emitted by the laser collimator is respectively directed to the sensor below and the center of the detection surface of the test card above through the beam splitter prism, and then reflected back to the laser collimator through the beam splitter prism, and two reflection points appear on the display of the laser collimator, and the positions of the sensor and the test card are respectively adjusted so that the two reflection points on the display of the laser collimator overlap, and at this time the planes where the sensor and the test card are located are parallel;

[0010] S4: Adjust the centering of the lens and the sensor, place the lens above the sensor, collect and test the imaging quality of the test card, cyclically adjust the lens posture until the axis of the lens coincides with the axis of the sensor, and then apply glue to the lens and the sensor for curing.

[0011] According to some embodiments, step S1 specifically includes: reflecting the laser beam emitted by the laser collimator through a plane mirror in a vertical direction, observing a display connected to the laser collimator, observing the display connected to the laser collimator, and fixing the laser collimator when the reflection point remains within an error range.

[0012] According to some embodiments, step S2 is specifically as follows: after the laser beam emitted by the laser collimator is split by a dichroic prism, the downward laser beam is reflected by a horizontal plane mirror, and a display connected to the laser collimator is observed. When the reflection point remains within an error range, the dichroic prism is fixed.

[0013] According to some embodiments, further comprising:

[0014] S5: Testing the imaging data and quality of the medical electronic endoscope lens module under different back focal lengths and different object distances.

[0015] According to some embodiments, the laser collimator, the beam splitter, the sensor, the test card and the lens are all adjusted in position by a six-axis micro-motion stage.

[0016] In the second aspect, the present invention also provides a centering device for a medical electronic endoscope lens module, which includes a base, wherein the base is provided with two brackets, a horizontal laser collimator is fixed on one side bracket; a test card with an adjustable posture is fixed above the other side bracket in the vertical direction, a dichroic prism is fixed in the middle in the horizontal direction, a detachable and adjustable lens is fixed at the bottom, and an adjustable posture sensor is provided below the lens.

[0017] According to some embodiments, the laser collimator, the beam splitter, the sensor, the test card and the lens are all adjusted in position by a six-axis micro-motion stage.

[0018] According to some embodiments, the laser collimator is adjusted to be horizontal by a plane mirror arranged in a vertical direction.

[0019] According to some embodiments, the horizontal prism is adjusted to be horizontal by a plane mirror arranged in a horizontal direction.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The present invention provides a centering method and device for a medical electronic endoscope lens module, which uses a dichroic prism and a laser collimator to perform optical calibration to perform centering correction of a test card and a sensor, improves the alignment accuracy through optical-level alignment, and only needs to adjust the lens degree of freedom after the test card and the sensor are centered and fixed, thereby reducing the number of adjustment steps. In addition, the imaging quality of the test card is collected and the lens degree of freedom is fine-tuned to achieve the best imaging quality to replace the value of the test card observed by the human eye. Medical electronic endoscope lens modules can be assembled in batches quickly and efficiently, and a high one-time assembly pass rate is ensured, and the precision stability and consistency of the module are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of light for adjusting the level of a laser collimator provided in an embodiment of the present invention.

[0023] Figure 2 A schematic diagram of adjusting the parallel light rays of a beam splitter prism provided in an embodiment of the present invention.

[0024] Figure 3 A principle block diagram of adjusting the alignment of a sensor and a test card provided in an embodiment of the present invention.

[0025] Figure 4 This is a schematic diagram of the structure of the lens and sensor alignment in S4 provided by an embodiment of the present invention.

[0026] Figure 5 A principle block diagram of lens and sensor alignment provided in an embodiment of the present invention.

[0027] Figure 6 A schematic structural diagram of a centering device for a medical electronic endoscope lens module provided in an embodiment of the present invention.

[0028] Figure 7 A flow chart of a method for centering a medical electronic endoscope lens module provided in an embodiment of the present invention.

[0029] In the figure:

[0030] Laser collimator 1; beam splitter prism 2; test card 3; sensor 4; lens 5; base 6; display 7; six-axis micro-motion stage 8; plane mirror 9. DETAILED DESCRIPTION

[0031] The present invention is described in detail below in conjunction with the embodiments and drawings, but it should be understood that the embodiments and drawings are only used to exemplify the present invention and do not constitute any limitation on the protection scope of the present invention. All reasonable changes and combinations within the scope of the inventive concept of the present invention fall within the protection scope of the present invention.

[0032] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", "front", "rear" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention; the terms "first", "second", and "third" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance. In addition, unless otherwise clearly specified and limited, the terms "set", "install", "connected", and "connected" should be understood in a broad sense, for example, it 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 it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] The present invention will be further described below in conjunction with the accompanying drawings.

[0034] Example 1

[0035] like Figure 7 The present invention discloses a centering method for a medical electronic endoscope lens module, which uses a laser collimator 1, a beam splitter 2, a test card 3, a sensor 4 to be centered, and a lens 5. The laser collimator 1 is used to emit a horizontal laser beam to illuminate the beam splitter 2 located in the horizontal direction. The beam splitter 2 divides the laser beam into two vertical laser beams, the upper one is the test card 3, and the lower one is the sensor 4. By adjusting the planes of the test card 2 and the sensor 4 to achieve a parallel and centering state, the lens 6 is inserted between the test card 3 and the sensor 4, and the MTF data of the test card is collected and tested, and the position of the lens 6 is adjusted; the axis of the lens 6 coincides with the axis of the sensor 4 or the imaging quality of the test card 3 reaches the design target or the best imaging quality, and it can also be considered that the lens 6 is assembled to the best position; then the lens 6 and the sensor 4 can be fixed with glue. The laser collimator 1, the beam splitter 2, the test card 3, the sensor 4, and the lens 5 are all adjusted in six degrees of freedom using a corresponding six-axis micro-motion stage 8.

[0036] The test card 3 is an optical test card, which is a tool specially designed for testing the performance of optical equipment. It is a standard test pattern made on cardboard or special materials, and is used to evaluate the performance of optical equipment, such as video cameras, cameras, lenses, etc. According to different test requirements and standards, optical test cards can be divided into multiple types, such as ISO12233 resolution test cards or SFRplus test cards, etc. Sensor 4 is a lens sensor, which is a device responsible for converting light into electronic signals. It is installed inside the lens and can convert light into digital images and transmit them to the processor behind through a data line, thereby generating the photos or videos you see; the main types are CCD and CMOS, and the sensor in this embodiment is of CMOS type.

[0037] like Figure 1 The device used for centering includes a base 6 arranged at the bottom, and three fixed brackets are arranged on the base 6. The left and right brackets are parallel, and the middle bracket is higher and arranged at the back. The left bracket is provided with a laser collimator 1, which is equipped with a six-axis micro-motion stage 8 for adjusting its position. A display 4 is connected to the top of the laser collimator 1; a test card 3 is arranged above the middle bracket, a dichroic prism 2 is arranged in the middle, and a sensor 4 is arranged vertically below. The lens 5 can be inserted between the dichroic prism 2 and the sensor 4. The test card 3, the dichroic prism 2 and the sensor 4 are respectively equipped with a six-axis micro-motion stage 8; a plane mirror 9 is vertically arranged on the right bracket, and the plane mirror 9 is used to adjust the horizontal base plane of the laser collimator 1 to be parallel. Similarly, when adjusting the dichroic prism 2 in the horizontal direction, another plane mirror 9 arranged on a six-axis micro-motion stage 8 can be used to adjust its horizontal reference. The present invention is suitable for the needs of centering and testing of medical electronic endoscope lens modules.

[0038] This embodiment provides a method for centering a medical electronic endoscope lens module, comprising the following steps:

[0039] S1: Adjust the laser collimator 1 to be parallel to the horizontal base plane, specifically:

[0040] like Figure 1 , the plane mirror 9 is connected to the right bracket and adjusted to be perpendicular to the base surface, and the six-axis micro-motion stage A2 of the laser collimator 1 is adjusted to make the laser collimator 1 perpendicular to the plane mirror 9. At this time, the laser collimator 1 is aligned and parallel to the base surface. After that, the six-axis micro-motion stage A2 of the laser collimator 1 is fixed, as shown in FIG. Figure 1 shown.

[0041] S2: Adjust the plane where the beam splitter prism 2 is located to be parallel to the base plane, specifically:

[0042] Fix the plane mirror 9 on a six-axis fine-motion stage 8 placed on the base 6, adjust the six-axis fine-motion stage 8 of the beam splitter prism 2 so that the laser emitted by the laser collimator 1 is reflected by the reflection surface of the beam splitter prism 2 to the horizontal plane mirror 9 and then reflected back along the original path, so that the reflection point on the display 7 is within the error range, and rotate the plane mirror 9. If the reflection point on the display 7 is always within the error range, it can be assumed that the plane where the beam splitter prism 2 is located is parallel to the base surface. After that, the six-axis fine-motion stage of the beam splitter prism 2 is fixed, such as Figure 2 shown.

[0043] S3: Use the beam splitter prism 2 to simultaneously calibrate the plane where the test card 3 and the sensor 4 are located, specifically:

[0044] The beam splitter prism 2 and the reflected light are Figure 3 As shown, after analysis, the intensities of the upper and lower reflected lights are 1 / 4 and 1 / 16 of the original laser respectively; the laser emitted by the laser collimator 1 is respectively irradiated to the planes where the sensor 4 and the test card 3 are located through the dichroic prism 2, and then reflected back through the dichroic prism 2 to form two reflection points on the display 5 of the laser collimator 1. The degrees of freedom of the six-axis micro-motion stage 8 corresponding to the sensor 4 and the test card 3 are adjusted respectively to make the two reflection points on the display 7 coincide. At this time, it can be considered that the planes where the sensor 4 and the test card 3 are located are parallel.

[0045] S4: Adjust the centering of the lens 5 and the sensor 4, specifically:

[0046] At this time, the planes where the sensor 4 and the test card 3 are located have reached a parallel and centered state. The lens 5 is placed on the sensor 4 and the lens 5 is adjusted by its six-axis micro-motion stage 8. Figure 4 As shown, by collecting and testing the MTF data of the test chart 3 and adjusting the degrees of freedom of the six-axis micro-motion stage 8 of the lens 5 to change the posture of the lens 5, the axis of the lens 5 coincides with the axis of the sensor 4, as shown in FIG. Figure 5 As shown, the glue is then cured, and the imaging data and quality of the lens as a whole are tested under different back focal lengths and different object distances. The way to test the image in this embodiment is to test the MTF data of the image. The MTF test is used to evaluate the imaging performance of an optical system (such as a lens, a camera, etc.), especially its contrast restoration capability. For lens imaging testing, there are other testing methods, such as SFR data testing, and image distortion, contrast, uniformity and other indicators of optical test cards.

[0047] When a large number of medical electronic endoscope lens modules need to be centered, after executing S1 and S2, it is only necessary to cycle through S3 and S4 to quickly execute the centering or testing tasks for a large number of modules.

[0048] Of course, in some other examples, the base 6 is located on a horizontal plane, and the laser collimator 1 and the beam splitter 2 can also be adjusted to a horizontal level by other level adjustment instruments. After the laser collimator 1 and the beam splitter 2 are fixed parallel to the horizontal base, the centering and testing of steps S3 and S4 can be directly performed.

[0049] The above embodiments are only preferred implementations of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A centering method for a medical electronic endoscope lens module, characterized in that: The steps are as follows: S1: Adjust the laser collimator to be parallel to the horizontal base plane; S2: Adjust the plane where the beam splitter prism is located to be parallel to the horizontal base plane; S3: using a beam splitter prism to simultaneously calibrate the planes where the test card and the sensor are located, the laser beam emitted by the laser collimator is respectively irradiated to the center of the detection surface of the sensor below and the test card above through the beam splitter prism, and then reflected back to the laser collimator through the beam splitter prism, and two reflection points appear on the display of the laser collimator, and the positions of the sensor and the test card are respectively adjusted so that the two reflection points on the display of the laser collimator overlap, and at this time the planes where the sensor and the test card are located are parallel; S4: Adjust the centering of the lens and the sensor, place the lens above the sensor, collect and test the imaging quality of the test card, cyclically adjust the lens posture until the axis of the lens coincides with the axis of the sensor, and then apply glue to the lens and the sensor for curing.

2. The centering method for a medical electronic endoscope lens module according to claim 1, characterized in that: Step S1 specifically includes: reflecting the laser beam emitted by the laser collimator through a plane mirror in a vertical direction, observing a display connected to the laser collimator, and fixing the laser collimator when the reflection point remains within an error range.

3. The centering method for a medical electronic endoscope lens module according to claim 2, characterized in that: Step S2 is specifically as follows: after the laser beam emitted by the laser collimator is split by a beam splitter prism, the downward laser beam is reflected by a horizontal plane mirror, and the display connected to the laser collimator is observed. When the reflection point remains within the error range, the beam splitter prism is fixed.

4. The centering method for a medical electronic endoscope lens module according to claim 1, characterized in that: Also includes: S5: Testing the imaging data and quality of the medical electronic endoscope lens module under different back focal lengths and different object distances.

5. The centering method for a medical electronic endoscope lens module according to any one of claims 1 to 4, characterized in that: The laser collimator, the beam splitter, the sensor, the test card and the lens are all adjusted in position and posture through a six-axis micro-motion stage.

6. A centering device for a medical electronic endoscope lens module, characterized in that: The invention comprises a base, wherein the base is provided with two brackets, a laser collimator in the horizontal direction is fixed on one bracket, a test card with adjustable posture is fixed on the upper part of the other bracket in the vertical direction, a beam splitter prism is fixed in the horizontal direction in the middle part, a detachable and posture-adjustable lens is fixed on the lower part, and a sensor with adjustable posture is provided under the lens.

7. The centering device for a medical electronic endoscope lens module according to claim 6, characterized in that: The laser collimator, the beam splitter, the sensor, the test card and the lens are all adjusted in position and posture through a six-axis micro-motion stage.

8. The centering device for a medical electronic endoscope lens module according to claim 6, characterized in that: The laser collimator is adjusted to be horizontal by a plane mirror arranged in a vertical direction.

9. The centering device for a medical electronic endoscope lens module according to claim 6, characterized in that: The horizontal prism is adjusted to be horizontal by a plane mirror arranged in a horizontal direction.

Images