CN108957781A - Optical lens adjustment and detection system and method - Google Patents

Abstract

An optical lens assembly and detection system, including assembly equipment and image quality detection equipment; the assembly equipment includes an eccentricity measurement device and a mirror distance measurement device, and the image quality detection equipment includes a wavefront aberration detection device; the eccentricity measurement device It includes an optical measurement head, an air bearing turntable and a column guide rail. The optical measurement head includes an illumination module, a projection module, a microscopic secondary amplification module and a first detector. The optical measurement head is slidably connected to the column guide rail. The optical measurement head can move along the column guide rail Moving up and down, the air bearing turntable is used to fix the lens to be tested. The above-mentioned optical lens assembly and inspection system can not only detect the eccentricity of the lens to be tested, the distance between the lenses to be tested and the thickness of the lens to be tested, but also detect the wavefront aberration of the entire lens to be tested, and evaluate the performance of the entire lens to be tested. Image quality, and the microscopic secondary magnification module of the optical measuring head is used to re-magnify the imaging of the projection module to improve the detection accuracy of the optical lens assembly and detection system.

Description

Optical lens assembly and testing system and method

technical field

The invention relates to the technical field of optical adjustment, in particular to an optical lens adjustment and detection system and method.

Background technique

With the rapid development of optoelectronic technology, a large number of high-end lenses appear in various fields such as scientific research and life, such as mobile phone lenses, endoscopes, high-end microscope objectives, surveillance mirrors, etc. The production and processing of these lenses are closely related to optical adjustment. Strictly controlling the distance between the eccentricity of the lens and the mirror surface, and quantifying the imaging quality of the lens become the key to the adjustment of the optical lens.

Lens eccentricity measurement is the application of relevant measurement methods to measure the tilt and radial offset of the lens. The measurement of the distance between the mirror surfaces is to measure the thickness of the optical material (lens) and its air gap by using related measurement methods. Lens eccentricity and spacing measurements provide accurate evaluation data for lens assembly tolerances and indicate the direction of optical assembly improvement. Finally, the lens assembly and adjustment can meet the design tolerance requirements, and good optical performance can be obtained. Wave aberration detection is a detection method that uses technologies such as interference and wavefront sensors to quantitatively evaluate the imaging quality of lenses. The image quality inspection module is introduced into the lens assembly system to realize the integration of assembly and inspection. While quantifying the tolerance, an evaluation of the lens image quality inspection is given.

However, due to the limitation of the measurement accuracy of the linear guide rail and the grating ruler, the measurement accuracy of the traditional loading and inspection system is not high.

Contents of the invention

In view of this, it is necessary to provide an optical lens assembly and detection system and method with high measurement accuracy.

An optical lens assembly and inspection system, including assembly equipment and image quality inspection equipment;

The assembly and adjustment equipment includes an eccentricity measurement device and a mirror distance measurement device, and the image quality detection device includes a wavefront aberration detection device;

The eccentricity measurement device includes an optical measuring head, an air bearing turntable and a column guide rail, the optical measuring head includes an illumination module, a projection module, a microscopic secondary amplification module and a first detector, and the optical measuring head is connected to the The column guide rail is slidingly connected, the optical measuring head can move up and down along the column guide rail, and the air-floating turntable is used to fix the lens to be measured.

In one embodiment, the air bearing turntable includes an air bearing and a four-dimensional adjustment frame, and the four-dimensional adjustment frame is used to fix the lens under test and adjust the mechanical axis of the lens under test.

In one embodiment, the axial and radial asynchronous runout of the air bearing turntable is less than 20 nm, and the axial and radial synchronous runout of the air bearing turntable is less than 70 nm.

In one embodiment, the rotary encoding positioning accuracy of the air bearing turntable is 1".

In one embodiment, the projection module includes a collimating objective lens and a switching objective lens, the collimating objective lens collimates the light emitted by the center of the target; the switching objective lens includes a switching turntable and multiple groups of objective lenses with different focal lengths, the Multiple groups of objective lenses are arranged on the switching dial, and the objective lenses of each group are switched through the switching dial to meet the measurement of the lens to be measured with different curvatures, and the objective lens projects the target pattern onto the lens to be measured. The center of curvature is the image plane.

In one embodiment, the mirror distance measurement device includes an interference optical system and a focusing lens;

The interference optical path system includes a long coherent scale optical path module and a short coherent measurement optical path module;

The long coherent scale optical path module includes a long coherent light source, a first coupler, a reference arm, a scale delay arm and a second detector, the reference arm is provided with an optical fiber retroreflector, and the scale delay arm is provided with a A movable reflector, the light emitted by the long-term coherent light source is divided into two paths through the first coupler, one path enters the reference arm, and the other path enters the scale delay arm, and finally the two paths of light are reflected back to the first coupling The detector forms interference and is received by the second detector;

The short coherent measurement optical path module includes a short coherent light source, a second coupler, a first circulator, a second circulator, a measurement arm, a third coupler and a balance detector, and the light emitted by the short coherent light source passes through the The second coupler is divided into two paths, one path enters the scale delay arm through the first circulator, and the other path enters the measurement arm through the second circulator, the reflected light of the scale delay arm and the The reflected light of the measuring arm respectively exits the ports of the first circulator and the second circulator to form an interference signal at the third coupler, and is received by the balance detector;

The long coherent scale optical path module and the short coherent measurement optical path module share the scale delay arm equipped with the movable mirror, and are coupled and split through a first wavelength division multiplexer.

In one embodiment, the axial scanning system of the scale delay arm includes a collimating objective lens, a corner mirror, a plane mirror and a linear guide rail;

The collimating objective lens and the plane reflector are fixed on one end of the linear guide rail;

The corner reflector is fixed on the slider of the linear guide rail, and the corner reflector makes the reflected light exit at the same angle as the incident light;

The outgoing light from the optical fiber is collimated by the collimating objective lens and then incident on the corner reflector, and finally the outgoing light hits the plane reflector, is reflected by the plane reflector, and returns to the same path.

In one embodiment, the wavefront aberration detection device includes a collimating beam expander, a beam splitter, a beam expander assembly, a standard mirror and a wavefront sensor;

The light emitted from the fiber head passes through the collimating beam expander and is reflected by the beam splitter into the beam expander assembly. The expanded parallel beam passes through the lens under test and irradiates the standard reflector in a confocal manner. The light beam reflected by the mirror returns to the wavefront sensor through the original path.

A method for assembling and testing an optical lens, comprising the following steps:

S10, importing the data of the lens to be tested, and determining the position of the spherical center image of each surface, and initializing the zero point position;

S20, loading a mechanical lens barrel, and using a dial indicator to adjust the mechanical axis of the lens barrel to coincide with the rotation axis of the air bearing turntable;

S30. Using the eccentricity difference measuring device and the mirror distance measuring device to adjust the lens of the lens to be tested;

S40, switch to the wavefront detection mode, and use the wavefront aberration detection device to measure the wavefront aberration;

S50, judging whether the image quality meets the requirement;

S60, if so, end the adjustment;

S70. If not, switch back to the assembly and adjustment mode, detect the eccentricity and spacing of the lens to be tested, analyze the measured data, and introduce it into optical design software for optimization and redesign;

S80. Using the redesigned parameters, repeat steps S30 to S50 until the image quality meets the requirements.

In one embodiment, the method for adjusting the lens of the lens to be tested by using the mirror distance measuring device includes the following steps:

Solve the coherent signal envelope of the short coherent optical path signal by using the de-enveloping algorithm, and then use the peak-finding algorithm to find the position of the signal point of each mirror;

Find the signal point of the corresponding long coherent scale delay optical path through the position of the signal point, and use the phase shift algorithm to find the phase of each point;

Calculate the number a of interference signals between each mirror surface and the phase difference in the period between each surface From this, the optical path difference between the mirrors can be obtained as: Where λ is the wavelength of long-term coherent light;

The thickness between the mirror surfaces is: d=OLD/n, where n is the refractive index of the medium between the surfaces where the short coherent light is located.

The above-mentioned optical lens assembly and detection system can not only detect the eccentricity of the lens to be tested, the distance between the lens to be tested and the thickness of the lens to be tested, It can also detect the wavefront aberration of the entire lens to be tested, and evaluate the image quality of the entire lens to be tested, and the optical measurement head includes a projection module and a microscopic secondary amplification module. The imaging is enlarged twice to improve the detection accuracy of the optical lens adjustment and detection system.

Description of drawings

Fig. 1 is a structural schematic diagram of an optical element of an optical lens assembly and detection system according to an embodiment;

Figure 2 is a switching optical path diagram of the optical lens assembly and detection system;

Fig. 3 is a structural schematic diagram of the optical lens assembly and detection system;

Fig. 4 is the switching dial of the objective lens of the eccentricity measurement head and the reference mirror for wavefront aberration measurement;

Fig. 5 is the schematic diagram of the principle of the eccentricity measurement device;

Fig. 6 is a principle optical path diagram of the mirror spacing measuring device;

Fig. 7 is a short-coherent and long-coherent acquisition signal diagram of the mirror spacing measurement system;

Fig. 8 is the optical path design diagram of the scale delay arm in the mirror distance measuring device;

Figure 9a is a schematic structural view of the eccentricity measurement module;

Fig. 9b is a schematic diagram of using the eccentricity measurement module to complete the double-lens bonding;

FIG. 10 is a flow chart of an optical lens assembly and inspection method according to an embodiment.

Detailed ways

In order to make the purpose, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

As shown in FIG. 1 , an optical lens assembly and inspection system according to an embodiment includes assembly equipment and image quality inspection equipment. The assembly equipment includes an eccentricity difference measurement device 100 and a mirror distance measurement device 200 , and the image quality detection device includes a wavefront aberration detection device 300 .

The eccentricity measurement device 100, the mirror distance measurement device 200 and the wavefront aberration detection device 300 of the optical lens assembly and detection system are independent of each other and can be selectively assembled and used according to user needs.

Please refer to FIG. 2 and FIG. 3 , the eccentricity measurement device 100 includes an optical measuring head 605 , an air bearing turntable 610 and a column guide rail 604 . The optical measurement head 605 includes an illumination module 3 , a projection module 5 , a microscopic secondary amplification module 2 and a first photodetector 1 . The optical measuring head 605 is slidingly connected with the column guide rail 604, and the optical measuring head 605 can move up and down along the column guide rail 604, which is convenient for the optical measuring head 605 to move up and down to find the image of the center of the sphere. The air bearing turntable 14 is used to fix the lens to be tested.

The above-mentioned optical lens assembly and detection system can not only detect the eccentricity of the lens to be tested, the distance between the lens to be tested and the distance between the lens to be tested can also detect the wavefront aberration of the entire lens to be tested, and evaluate the image quality of the entire lens to be tested, and the optical measuring head 605 includes a projection module and a microscopic secondary amplification module 2, which is used for the microscopic secondary amplification module 2 The imaging through the projection module 5 is enlarged again to improve the detection accuracy of the optical lens assembly and detection system.

FIG. 2 is a switching optical path of the eccentricity measurement device 100 , the mirror distance measurement device 200 and the wavefront aberration detection device 300 of the above-mentioned optical lens assembly and detection system. The left side is the assembly and adjustment equipment, including the upper end eccentricity difference measuring device 100 and the focusing lens 316 of the lower end mirror distance measuring device 200 . On the right is the wavefront aberration detection device 300 . After the lens assembly and adjustment is completed, the standard reflector 14 (reference mirror) is switched to the optical path by turning the switching dial (as shown in FIG. 4 ), and enters into the wavefront aberration measurement mode. The standard mirror 14 is a reference mirror.

In one embodiment, the air bearing turntable 14 includes an air bearing and a four-dimensional adjustment frame, and the four-dimensional adjustment frame is used to fix the lens to be tested and adjust the mechanical axis of the lens to be tested.

In one embodiment, the axial and radial asynchronous runout of the air bearing turntable 14 is less than 20 nm, and the axial and radial synchronous runout of the air bearing turntable 14 is less than 70 nm. The positioning accuracy of the rotary encoding of the air-floating turntable 14 is 1". With this arrangement, the eccentricity measurement accuracy of the eccentricity difference measuring device can reach 0.1 μm.

In one embodiment, the post guide rail 604 has high requirements on repeat positioning accuracy, and its repeat positioning accuracy reaches 1 μm in order to meet the automatic measurement of multi-mirror surfaces.

In one embodiment, the lighting module 3 is a cold light source or an LED lighting target. There are two types of target patterns, one is a crosshair, and the other is a rectangular array with different spatial frequency distributions.

In one embodiment, the projection module 5 includes a collimating objective lens and a switching objective lens. The collimating objective lens collimates the light emitted from the center of the target. Switch the objective lens and project the target pattern onto the image plane of the center of curvature of the lens to be tested. The switching objective lens includes multiple sets of objective lenses with different focal lengths to meet the measurement of the lenses to be tested with different curvatures, and each set of objective lenses is switched through the switching dial. The focal lengths of the objective lens group are: +20, +50, +100, +150, +200, +400, +800, +1200, +1600, +2000, -2000, -1600, -1200, -800, -400 , -200, etc., for users to choose.

Specifically, the structure of the switching turntable is shown in FIG. 4 . In practical applications, a suitable combination of objective lenses is selected for different lenses to be tested to complete multi-lens inspection.

In one embodiment, the microscopic secondary magnification module 2 includes a microscopic objective lens and a tube lens.

The eccentricity measurement module software of the eccentricity measurement device can automatically calculate the spherical center image position of each surface of the lens. The so-called spherical center image position is the position where the spherical center of each mirror surface of the measured lens is imaged by all the optical lenses above the surface.

The eccentricity measurement module software can automatically organize the eccentricity difference data of each surface, and calculate the eccentricity of each lens relative to the rotation axis of the air bearing turntable 14 . When the optical axis of the installed lens does not coincide with the rotating axis of the air bearing turntable 14, the best optical axis of the lens can also be fitted.

In actual measurement, it is necessary to manually input or import through the optical lens file the curvature radius, thickness, spacing and material parameters of the glass. It is used for the eccentricity measurement module software to generate the position data of the spherical center image, and guide the measurement of the eccentricity difference of each mirror surface and the fitting of the best optical axis.

Specifically, please refer to FIG. 2 . The eccentricity measurement device 100 includes a light source 3011, a condenser lens 3012, a target 3013, a beam splitter 4, a projection module 5, an air bearing turntable 14, a microscopic secondary amplification module 2 and a first detector. 1. The mirror 6 to be tested is set on the air bearing turntable 14 . The first detector 1 is a CCD camera.

The light source 3011 , the condenser 3012 , the target 3013 and the beam splitter 4 are arranged sequentially in a straight line.

The projection module 5, the beam splitter 4, the microscopic secondary amplification module 2 and the detector 1 are arranged in sequence in a straight line, and the projection module 5, the microscopic secondary amplification module 2 and the first detector 1 are located in the reflection optical path of the beam splitter 4 on the straight line.

The light emitted by the light source 3011 is irradiated on the target 3013 after passing through the condenser lens 3012. After the pattern of the target 3013 is reflected by the beam splitter 4, it is imaged on the curvature center plane of the mirror to be tested by the projection module 5, and the image of the center of curvature is captured by the mirror to be tested. The reflection is imaged above the beam splitter 4 through the projection module 5 , and the center of curvature image is imaged on the first detector 1 through the microscopic secondary amplification module 2 .

The principle of the reflective self-collimation eccentricity measurement of the eccentricity difference measuring device 100 is shown in Figure 5. Please refer to Figure 2 at the same time. The heart draws a circle with radius d. The image formed by the incident light beam of the projection module 5 and reflected by the measured mirror 6 will draw a circle with a radius of 2d=D. The curvature center image is finally imaged on the first detector 1 through the optical measuring head, and a circle is drawn with D' as the radius. β=D'/D is the magnification of the whole system.

Please refer to FIG. 1 and FIG. 2 at the same time. In one embodiment, the mirror distance measuring device 200 includes an interference optical system and a focusing lens 316 . Please refer to FIG. 3 at the same time, the interference optical system is set in the optical fiber optical box 601 . The focusing lens 316 and the wavefront aberration detection device 300 are integrated in the concentration box 611 . The optical lens assembly and inspection system 100 also includes a control box 608 .

Please refer to FIG. 6 , the interference optical system includes a long coherent scale optical path module and a short coherent measurement optical path module.

The long coherent scale optical path module includes a long coherent light source 301, a first coupler 304, a reference arm, a scale delay arm and a second detector 302, the reference arm is provided with an optical fiber retroreflector 309, and the scale delay arm is provided with a movable Reflector, the light emitted by the long-term coherent light source 301 is divided into two paths through the first coupler 304, one path enters the reference arm, and the other path enters the scale delay arm, and finally the two paths of light are reflected back to the first coupler 304 to form interference and are transmitted by the second Detector 302 receives. The result is shown in the scale signal in Figure 5.

Further, one path of light entering the reference arm is reflected back to the first coupler 304 after the adjustable attenuator 307 and the optical fiber retroreflector 309 . Another path of light entering the delay arm of the scale enters the movable mirror 310 through the first wavelength division multiplexer 306 and the collimating mirror 308 . The movable mirror 310 is disposed on the linear guide rail 311 .

In one embodiment, the long-term coherent light source 301 may be a distributed feedback laser. The central wavelength of the distributed feedback laser is 1550nm and the bandwidth is 3M. Its coherence length is required to be greater than twice the effective distance of the mirror distance measurement, so as to ensure that the scale signal has a better contrast.

In one embodiment, the first coupler 304 is a 2×2 fiber optic coupler. Among them, 50% of the light of one path enters the reference arm, and 50% of the light of the other path enters the scale delay arm.

According to the temporal coherence of light, when the scale delay arm moves, the interference light intensity of the second detector 304 will change brightly and darkly, and each periodic change represents a difference of one wavelength in the optical path, so by counting the light intensity changes, we can Accurately calibrate the amount of movement of the scale delay arm.

The short coherent measurement optical path module includes a short coherent light source 321, a second coupler 320, a first circulator 305, a second circulator 318, a measurement arm, a third coupler 314 and a balance detector 313, and the light emitted by the short coherent light source 321 After the second coupler 320, it is divided into two paths, one path enters the scale delay arm through the first circulator 305, and the other path enters the measurement arm through the second circulator 318, and the reflected light of the scale delay arm and the reflected light of the measurement arm pass through the second circulator respectively. The ports of the first circulator 305 and the second circulator 318 form an interference signal at the third coupler 314 and are received by the balance detector 313 . The result is shown in the measured signal in Figure 7.

Further, the short coherent light emitted by the short coherent light source 321 is divided into two paths by the second coupler 320 and enters the first circulator 305 and the second circulator 318 respectively. The light emitted from the No. 2 end of the first circulator 305 is incident on the movable reflector 310 after passing through the first wavelength division multiplexer 306 and the collimating mirror 308. end, and finally enter the 2X2 third coupler 314 through the adjustable attenuator 315 (50:50). The second wavelength division multiplexer 317 couples the outgoing light of the No. 2 end of the second circulator 318 and the outgoing light of the indicator light source 319, wherein the indicator light source 319 has a wavelength of 660 nm, and is incident on the lens under test 312 through the focusing lens 316 Among them, the short coherent light reflected by each mirror in the lens under test 312 returns to the second circulator 318 through the focusing lens 316 and the second wavelength division multiplexer 317, and exits from the No. 3 end, and finally passes through the adjustable attenuator 315 Enter the third coupler 314 . The two paths of light interfere at the third coupler 314 and are finally received by the balanced detector 313 .

The long coherent scale optical path module and the short coherent measurement optical path module share a scale delay arm equipped with a movable mirror 310 , and are coupled and split through the first wavelength division multiplexer 306 . The long coherent scale optical path module and the short coherent measurement optical path module share the scale delay arm, which can increase the accuracy of scale measurement and improve the measurement accuracy to 0.1 μm.

In one embodiment, the short coherent light source 321 is a superradiant short coherent light source. The central wavelength of the short coherent light source is 1310nm, and the half-maximum width is 40-120nm. Among them, the larger the half-peak width is, the shorter the coherence length is, and the higher the axial resolution is.

In one embodiment, the second coupler 320 is a 95:5 fiber optic coupler. The short coherent light emitted by the short coherent light source is divided into two beams by a 95:5 fiber coupler, 5% of the light enters the scale delay arm through the first circulator 305 , and 95% of the light enters the measurement arm through the second circulator 318 .

According to the principle of short-coherence tomography, in the short-coherence measurement optical path, the interference signal can only be generated when the light paths of the measuring arm and the scale delay arm are close to each other, thereby marking the position of each mirror.

In one embodiment, please refer to FIG. 8 , the axial scanning system of the scale delay arm includes a collimating objective lens 212 , a corner mirror 214 , a plane mirror 216 and a linear guide.

The collimating objective lens 212 and the plane mirror 216 are fixed on one end of the linear guide rail.

The corner reflector 214 is fixed on the slider of the linear guide rail, and the corner reflector 214 makes the reflected light exit at the same angle as the incident light.

The outgoing light from the fiber is collimated by the collimating objective lens 212 and then incident on the corner reflector 214 , and finally the outgoing light strikes the plane reflector 216 , is reflected by the plane reflector 216 and returns on the same path. In the actual assembly and adjustment process, it is necessary to adjust the plane reflector 216 to make the light return along the original path, so that the coupling efficiency of the collimating objective lens 212 can be maximized.

The corner mirror 214 of the axial scanning system of the scale delay arm has low stability requirements and is suitable for application in a moving optical path. In addition, the folded optical path composed of the corner mirror 214 and the plane mirror 216 reduces the stroke requirement of the linear guide.

During the measurement process, the mirror distance measurement device 200 needs to strictly control the timing of signal acquisition, that is, simultaneously record the signal of the long coherent scale optical path and the signal of the short coherent measurement optical path.

In FIG. 2 , the mirror group 8 is used to introduce the measurement light of the mirror spacing measurement module to the lens under test.

In one embodiment, please refer to FIG. 2 , the wavefront aberration detection device 300 includes a collimator beam expander 1112 , a beam splitter 12 , a beam expander assembly 10 , a standard mirror 14 and a wavefront sensor 13 . The light emitted from the fiber head 1111 passes through the collimator beam expander 1112 and is reflected by the beam splitter 12 to enter the beam expander assembly 10 . The expanded parallel light beam passes through the lens under test 6 and irradiates to the standard reflector 14 in a confocal manner. The light beam reflected by the standard reflector 14 returns to the wavefront sensor 13 through the original path.

Specifically, the lens under test 6 is set on the four-dimensional adjustment table of the air bearing turntable 7 . After the centering adjustment is completed, there is no need to adjust the lens, and the integration of the adjustment system simplifies the steps of measurement. Another advantage of the integrated adjustment system is that the lens can be automatically adjusted by using the eccentricity difference measuring device 100, which reduces the wave aberration introduced by the tilt of the lens.

In the actual installation and adjustment process, it is necessary to use the wavefront aberration detection device 300 to perform wavefront detection on the outgoing light of the collimator beam expander 1112 and the beam expander assembly 10, so as to guide the system installation and adjustment. The light source module 11 for wavefront aberration detection is used to provide a light source.

In one embodiment, the wavefront sensor 13 may be a Hartmann-Shack wavefront sensor.

In one embodiment, the confocal position of the beam expander assembly 10 introduces a small hole for spatial filtering, so as to prevent system stray light from entering the Hartmann-Shack wavefront sensor 13 and affecting the measurement.

In one embodiment, the standard mirror 14 is a spherical standard mirror. The standard mirror 14 is the reference mirror of the wavefront aberration detection device 300 .

The standard reflector 14 is fixed on the switch turntable through a four-dimensional adjustment frame. The four-dimensional adjustment frame with a small adjustment amount and the column guide rail with a large stroke form a five-dimensional adjustment to meet the detection of objective lenses with different focal lengths. In the actual measurement, the optical path is returned along the original path through the five-dimensional adjustment of the standard mirror, and then the measurement is performed.

The wavefront aberration detection device 300 needs to calibrate the wavefront aberration of the optical system and the standard mirror during the measurement process. The systematic wave aberration needs to be removed when decomposing the wavefront.

In addition, referring to FIG. 10 , an embodiment of an optical lens assembly and inspection method is also provided, including the following steps:

S10. Importing the data of the lens to be tested, determining the positions of the center images of the spheres on each surface, and initializing the zero position.

S20. Load a mechanical lens barrel, and use a dial gauge to adjust the coincidence of the mechanical axis of the lens barrel with the rotation axis of the air bearing turntable.

S30. Using the eccentricity difference measuring device and the mirror surface distance measuring device to assemble and adjust the lens of the lens to be tested.

S40. Switch to the wavefront detection mode, and use the wavefront aberration detection device to measure the wavefront aberration.

S50 , judging whether the image quality meets a requirement.

S60. If so, end the adjustment.

S70. If not, switch back to the assembly and adjustment mode, detect the eccentricity and spacing of the lens to be tested, analyze the measured data, and introduce it into the optical design software for optimization and redesign.

S80. Using the redesigned parameters, repeat steps S30 to S50 until the image quality meets the requirements.

The above optical lens assembly and testing method can not only detect the eccentricity of the lens to be tested, the distance between the lens to be tested and the thickness of the lens to be tested, but also can detect the wavefront aberration of the entire lens to be tested, and evaluate the performance of the entire lens to be tested. The image quality is high, and the installation, adjustment and detection only need a simple switch, and the measurement accuracy is high.

In one embodiment, the method of using the mirror distance measuring device to adjust the lens of the lens to be tested comprises the following steps:

S110. Solve the coherent signal envelope of the short coherent optical path signal by using the de-enveloping algorithm, and then use the peak-finding algorithm to find the position of the signal point of each mirror.

S120. Find the signal point corresponding to the delay optical path of the long coherence scale through the position of the signal point, and use a phase shift algorithm to obtain the phase of each point.

S130, calculate the number a of the interference signal between each mirror surface and the phase difference in the period between each surface From this, the optical path difference between the mirrors can be obtained as: where λ is the wavelength of long-term coherent light.

S140. The thickness between the mirror surfaces is: d=OLD/n, where n is the refractive index of the medium between the surfaces where the short coherent light is located.

Please refer to Figure 9a and Figure 9b, use the eccentricity difference measuring device to complete the double lens bonding, the specific steps are as follows:

S210. Place the bottom lens on the four-dimensional adjustment frame of the air-floating turntable, and use a vacuum pump to absorb and fix it.

S220, after gluing the glued surface, place the top lens.

S230. Import the optical parameters of the doublet mirror into the eccentricity measurement system, and calculate the curvature center image positions of each surface.

Optical parameters refer to parameters such as radius of curvature, mirror spacing, glass material, etc.

S240. Select a suitable detection objective lens, move the eccentric measuring head up and down, make the projection objective lens focus on the upper surface of the top lens, and set the position of the linear guide rail at this time as the reference position (relative zero position) of the curvature center image position.

S250. Move the focus point of the measuring head to the center image position of the curvature of the three surfaces respectively, initially test the situation that each surface draws a circle on the CCD, and properly adjust the inclination of the cemented lens so that the three surfaces can be completely positioned on the CCD. Draw a circle.

S260. Further measure the eccentricity of each surface of the bottom lens and the top lens, and fit the optical axes of the bottom lens and the top lens, as shown by axes AB and BC in FIG. 9b respectively.

S270, finely adjust the top lens until the axes AB and BC coincide.

S280, UV curing glue, complete lens gluing.

The above are only preferred embodiments of the present invention. It should be pointed out that those skilled in the art can make some improvements and modifications without departing from the principles of the present invention. These improvements and modifications should also be regarded as the present invention. protection scope of the invention.

Claims (10)

1. An optical lens assembly and detection system, characterized in that it includes assembly equipment and image quality detection equipment; The assembly and adjustment equipment includes an eccentricity measurement device and a mirror distance measurement device, and the image quality detection device includes a wavefront aberration detection device; The eccentricity measurement device includes an optical measuring head, an air bearing turntable and a column guide rail, the optical measuring head includes an illumination module, a projection module, a microscopic secondary amplification module and a first detector, and the optical measuring head is connected to the The column guide rail is slidingly connected, the optical measuring head can move up and down along the column guide rail, and the air-floating turntable is used to fix the lens to be measured. 2. The optical lens adjustment and detection system according to claim 1, wherein the air bearing turntable comprises an air bearing and a four-dimensional adjustment frame, the four-dimensional adjustment frame is used to fix the lens to be tested, and Adjust the mechanical axis of the lens to be tested. 3. The optical lens assembly and inspection system according to claim 1, wherein the axial and radial asynchronous runout of the air-floating turntable is less than 20 nm, and the axial and radial runout of the air-floating turntable is less than 20 nm. Synchronous jitter is less than 70nm. 4. The optical lens assembly and inspection system according to claim 1, wherein the positioning accuracy of the rotary encoding of the air bearing turntable is 1". 5. The optical lens assembly and detection system as claimed in claim 1, wherein the projection module includes a collimating objective lens and a switching objective lens, and the collimating objective lens collimates the light emitted by the center of the target; The switching objective lens includes a switching dial and a plurality of groups of objective lenses with different focal lengths. The plurality of groups of objective lenses are all arranged on the switching dial, and the objective lenses of each group are switched through the switching dial to meet the requirements of the lenses to be tested with different curvatures. For measurement, the objective lens projects the target pattern onto the image plane of the center of curvature of the lens to be tested. 6. The optical lens assembly and detection system according to claim 1, wherein the mirror distance measuring device comprises an interference optical system and a focusing lens; The interference optical path system includes a long coherent scale optical path module and a short coherent measurement optical path module; The long coherent scale optical path module includes a long coherent light source, a first coupler, a reference arm, a scale delay arm and a second detector, the reference arm is provided with an optical fiber retroreflector, and the scale delay arm is provided with a A movable reflector, the light emitted by the long-term coherent light source is divided into two paths through the first coupler, one path enters the reference arm, and the other path enters the scale delay arm, and finally the two paths of light are reflected back to the first coupling The detector forms interference and is received by the second detector; The short coherent measurement optical path module includes a short coherent light source, a second coupler, a first circulator, a second circulator, a measurement arm, a third coupler and a balance detector, and the light emitted by the short coherent light source passes through the The second coupler is divided into two paths, one path enters the scale delay arm through the first circulator, and the other path enters the measurement arm through the second circulator, the reflected light of the scale delay arm and the The reflected light of the measuring arm respectively exits the ports of the first circulator and the second circulator to form an interference signal at the third coupler, and is received by the balance detector; The long coherent scale optical path module and the short coherent measurement optical path module share the scale delay arm equipped with the movable mirror, and are coupled and split through a first wavelength division multiplexer. 7. optical lens adjustment and detection system as claimed in claim 6, is characterized in that, the axial scanning system of described scale delay arm comprises collimating objective lens, pyramid reflector, planar reflector and linear guide rail; The collimating objective lens and the plane reflector are fixed on one end of the linear guide rail; The corner reflector is fixed on the slider of the linear guide rail, and the corner reflector makes the reflected light exit at the same angle as the incident light; The outgoing light from the optical fiber is collimated by the collimating objective lens and then incident on the corner reflector, and finally the outgoing light hits the plane reflector, is reflected by the plane reflector, and returns to the same path. 8. The optical lens assembly and inspection system according to claim 1, wherein the wavefront aberration detection device includes a collimating beam expander, a beam splitter, a beam expander assembly, a standard mirror and a wavefront sensor; The light emitted from the fiber head passes through the collimating beam expander and is reflected by the beam splitter into the beam expander assembly. The expanded parallel beam passes through the lens under test and irradiates the standard reflector in a confocal manner. The light beam reflected by the mirror returns to the wavefront sensor through the original path. 9. A method for adjusting and detecting an optical lens, comprising the following steps: S10, importing the data of the lens to be tested, and determining the position of the spherical center image of each surface, and initializing the zero point position; S20, loading a mechanical lens barrel, and using a dial indicator to adjust the mechanical axis of the lens barrel to coincide with the rotation axis of the air bearing turntable; S30. Using the eccentricity difference measuring device and the mirror distance measuring device to adjust the lens of the lens to be tested; S40, switch to the wavefront detection mode, and use the wavefront aberration detection device to measure the wavefront aberration; S50, judging whether the image quality meets the requirements; S60, if so, end the adjustment; S70. If not, switch back to the assembly and adjustment mode, detect the eccentricity and spacing of the lens to be tested, analyze the measured data, and introduce it into optical design software for optimization and redesign; S80. Using the redesigned parameters, repeat steps S30 to S50 until the image quality meets the requirements. 10. optical lens adjustment and detection method as claimed in claim 9, is characterized in that, utilizes the mirror distance measuring device to assemble the method for the eyeglass of described lens to be tested comprising the following steps: Solve the coherent signal envelope of the short coherent optical path signal by using the de-enveloping algorithm, and then use the peak-finding algorithm to find the position of the signal point of each mirror; Find the signal point of the corresponding long coherent scale delay optical path through the position of the signal point, and use the phase shift algorithm to find the phase of each point; Calculate the number a of interference signals between each mirror surface and the phase difference in the period between each surface From this, the optical path difference between the mirrors can be obtained as: Where λ is the wavelength of long-term coherent light; The thickness between the mirror surfaces is: d=OLD/n, where n is the refractive index of the medium between the surfaces where the short coherent light is located.