CN107957626B - A six-degree-of-freedom parallel automatic polarization adjustment system and method for optical lenses - Google Patents

Abstract

A kind of six-freedom parallel automatic deflection adjusting system and method towards optical mirror slip, belongs to optical mirror slip precise automatic mounting technology field.The automatic deflection adjusting of eyeglass is realized based on the inclined measurement result in center and six-freedom parallel structure.Automatic deflection adjusting system is mainly made of lens barrel adjustment module, align measurement module and automatic deflection adjusting module.Automatic deflection adjusting method calculates two sphere centre coordinates of lens to be assembled based on align measurement data, six-degree-of-freedom parallel connection mechanism is driven to realize tuningout again, by the way of measurement and adjustment alternately, that is tuningout of every progress, center need to be re-measured partially to verify whether tuningout result meets the requirements, if being unsatisfactory for requiring, need to be fitted again optical axis again tuningout until precision reaches requirement.The present invention realizes the integration of align measurement and eyeglass adjust automatically, can rapid survey center of lens partially and adjustment offset, not only ensure that the tuningout precision of eyeglass met the requirements, but also substantially increase eyeglass adjustment efficiency.

Description

A six-degree-of-freedom parallel automatic polarization adjustment system and method for optical lenses

technical field

The invention relates to a 6-DOF parallel automatic polarization adjustment system and method for optical lenses, in particular to a 6-DOF parallel polarization adjustment system for optical lenses and an automatic and efficient polarization adjustment algorithm, which belongs to the automatic assembly of optical lens precision assembly and optical systems and electromechanical technology.

Background technique

With the rapid development of aerospace and digital technology, optical lens sets have been widely used in spacecraft, unmanned aerial vehicles, intelligent robots, digital cameras, and civilian mobile phones. The demand for high-efficiency and high-reliability assembly is increasing. strong. However, the current general situation is that the measurement and adjustment of the lens center deviation are basically performed manually, and the reliability of assembly accuracy and assembly efficiency are difficult to guarantee. Therefore, a more reliable and faster lens assembly system is urgently needed.

After literature and patent searches, the adjustment systems or devices related to lens centroid measurement and lens assembly are as follows:

(1) Application No. CN201310411023, the name of the invention is: a central deviation detection device and a detection method, which discloses a central deviation detection device and method with a simple structure, which can quickly and efficiently detect the central deviation of the lens under test, which solves the problem of mechanical In the three-coordinate method, it is laborious, time-consuming, low-efficiency, and low-precision to read data each time. However, this method is only limited to quickly measuring the center deviation of the lens, and there is no plan for adjusting the deviation.

(2) Application No. CN201410115050.4, the name of the invention is: Optical Lens Auxiliary Adjustment Device, which discloses an optical lens auxiliary adjustment device, which solves the problem of detecting the center deviation of the optical lens and the low measurement accuracy of the lens interval in the prior art. , The technical problem of high cost improves the efficiency of optical lens assembly and adjustment. However, although this device realizes the combination of the measurement of the central deviation and the measurement of the lens spacing, it still does not propose how to adjust the deviation after the central deviation of the lens is measured.

To sum up, although there are many measuring equipments for the center deviation of optical lenses, it is usually only possible to realize the automation of the lens center deviation measurement. When the lens has a center deviation, it still needs to be adjusted manually, although the efficiency is compared with pure manual assembly. It has been greatly improved, but it is still impossible to automate the entire process of lenses from measurement to polarization.

The center deviation automatic measurement and adjustment system for optical lenses provided by the present invention adopts the method of alternating measurement and adjustment, and realizes a high degree of integration of the center deviation measurement and lens adjustment.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a six-degree-of-freedom parallel automatic polarization adjustment system for optical lenses in view of the technical status of the existing optical lens center deviation measurement equipment that still needs to be adjusted manually and the efficiency is low when the lens has center deviation. And the method adopts the method of alternately performing measurement and adjustment, and realizes a high degree of integration of center deviation measurement and lens adjustment.

A six-degree-of-freedom parallel automatic polarization adjustment system and method for optical lenses, including a six-degree-of-freedom parallel automatic polarization adjustment system for optical lenses, referred to as "automatic polarization adjustment system" for short; and a six-degree-of-freedom parallel automatic polarization adjustment system for optical lenses Degree of freedom parallel automatic deviation adjustment method, referred to as "automatic deviation adjustment method".

The automatic polarization adjustment system realizes the integration of the central deviation measurement and the automatic adjustment of the lens. It can not only realize the rapid measurement of the central deviation of the lens, but also based on the measurement results of the central deviation, a six-degree-of-freedom parallel structure is proposed to realize the automatic adjustment of the lens deviation. Adjustment method; this automatic polarization adjustment system proposes a method of alternating measurement and adjustment during the lens assembly process. Every time adjustment is performed, the center offset should be re-measured to verify whether the adjustment result can meet the requirements. To meet the accuracy requirements, it is necessary to re-fit the optical axis and adjust the polarization again until the accuracy meets the requirements, which can ensure that the adjustment accuracy of the lens meets the requirements;

Among them, the automatic polarization adjustment system is mainly composed of the lens barrel adjustment module, the center deviation measurement module and the automatic polarization adjustment module; the automatic polarization adjustment system can realize the height integration of the center deviation measurement and the lens adjustment;

It is stipulated that the reference axis of the automatic polarization adjustment system is the rotation axis of the lower air-floating turntable in the lens barrel adjustment module; for a single lens with two spherical surfaces, the line connecting the two spherical centers is the optical axis of the lens.

Among them, the lens barrel adjustment module includes a lower air-floating turntable, a four-dimensional adjustment table, a lens barrel clamping mechanism and a dial indicator measuring mechanism; the dial indicator measuring mechanism includes a dial indicator motion platform, an upper dial indicator, and a lower dial indicator; The lower air-floating turntable is fixed on the equipment workbench, the four-dimensional adjustment table is fixed on the lower air-floating turntable, and the dial indicator measuring mechanism is fixed on the equipment workbench. The lower air-floating turntable has a central through hole, and the diameter of the through hole is The through hole is located at the shaft of the lower air-floating turntable, so that the light beam can pass through the lower air-floating turntable;

Among them, the diameter The range is arrive

The four-dimensional adjustment stage includes two linear displacement stages, an adjustment stage and a lens barrel clamp; the motion axes of the two linear translation stages are vertically stacked on each other in space, and the adjustment platform is fixed on the two linear translation stages, and the lens barrel clamp Fixed on the adjustment platform; the center of the four-dimensional adjustment platform has a diameter of The through hole of the 4D adjustment table is to allow the light beam to pass through the 4D adjustment stage. Considering that the solid part without the through hole may obstruct the optical path during the movement of the linear stage, the through hole of the 4D adjustment stage is larger than that of the lower air-floating turntable. ;

Among them, the diameter The range is In order to facilitate manual adjustment, it is preferred to use a fine thread marked with a scale to drive the adjustment platform, that is, use a centicard to drive the adjustment platform;

The adjustment platform mainly includes the working plate and the lower bottom plate; the rotating contact surface between the working plate and the lower bottom plate is a spherical surface, and there will be no horizontal displacement at the center of the sphere when leveling. The dial is just away from the table h, that is, the lower dial indicator is just pointing to the center of the sphere where the adjustment platform is in contact with the spherical surface, then during the deviation adjustment process, there will be no horizontal displacement at the height of the lower dial indicator, so there will be no horizontal displacement when adjusting the angle. Displacement, realizes the separate adjustment of angle and offset, and avoids errors in principle;

Among them, the range of height h is 40mm to 60mm;

The dial gauge measuring mechanism mainly includes the upper dial gauge, the lower dial gauge, the slide rail, and the x-y two-dimensional translation stage;

The connection method of the above four parts is as follows: both the upper dial indicator and the lower dial indicator are locked on the slide rail by screws to ensure that the measurement axes of the upper dial indicator and the lower dial indicator are in the same vertical plane; The screws are fixed on the x-y two-dimensional translation stage.

The center deviation measurement module mainly includes an autocollimator adjustment mechanism, an autocollimator and a 45° reflector; when the autocollimator is installed, the position and attitude of the autocollimator and the 45° reflector are adjusted to ensure self-collimation. Coaxiality between the optical axis of the straight instrument and the reference axis of the system;

The adjustment mechanism of the autocollimator includes a support plate, three screw adjustment mechanisms, and the support plate is placed horizontally on the frame. The screw adjustment mechanism is composed of three screws and a metal plate. A part of the metal plate is fixed to the frame by two screws, and the other part of the metal plate is fixed to the support plate by a screw. By adjusting the screws, the support plate can be adjusted in the frame. position; two screw adjustment mechanisms are arranged on both sides of the pallet, and one screw adjustment mechanism is arranged on the end face of the pallet; the autocollimator is placed horizontally on the pallet, and a ccd camera is fixed at the end of the autocollimator; 45° The mirror is used to turn the beam, turning the collimator's horizontal light into vertical light.

The automatic deviation adjustment module mainly includes a z-axis displacement stage, an upper air-floating turntable, a six-degree-of-freedom parallel mechanism, a six-degree-of-freedom force sensor and a pneumatic adsorption head; The movement axis is parallel to the system reference axis; the upper air-floating turntable is fixedly connected to the z-axis displacement stage through an adapter plate, and the coaxiality between the rotating shaft of the upper air-floating turntable and the system reference axis must be within the Inside; the base of the 6-DOF parallel mechanism and the upper air-floating turntable are fixedly connected through the transfer shaft, the 6-DOF parallel mechanism is placed upside down, and the coaxiality between the z-axis of the 6-DOF parallel mechanism and the system reference axis is guaranteed to be within within; one end of the six-degree-of-freedom force sensor is fixedly connected to the working surface of the six-degree-of-freedom parallel mechanism, and the geometric axis of the six-degree-of-freedom force sensor and the system reference axis are guaranteed to be within the same coaxiality. One end of the pneumatic suction head is fixedly connected with the six-degree-of-freedom force sensor, and the geometric axis of the pneumatic suction head and the coaxiality of the system reference axis are guaranteed to be within within;

The automatic offset adjustment method mainly includes data collection, calculation of spherical center coordinates and rapid offset adjustment;

Step 1. Collect data, and collect parameters such as curvature radius, diameter, material, thickness, lens interval and inner diameter of the lens barrel of the lens to be adjusted in advance;

Step 2. Determine the spatial coordinates of the spherical center of the lens to be adjusted by performing geometric calculation through the collected data;

If the lens to be adjusted is two spherical single lenses, the two spherical center coordinates corresponding to the two spherical single lenses are calculated as formulas (1) and (2):

The calculated spherical center coordinate values are all values in the offset adjustment coordinate system, and the offset adjustment coordinate system is specified as:

The x and y axes of the offset adjustment coordinate system coincide with the x and y axes of the autocollimator itself, the z axis of the offset adjustment coordinate system is vertically upward and coincides with the reference axis of the automatic offset adjustment system, and the z axis of the offset adjustment coordinate system The origin is set as the intersection of the first spherical surface of the first lens contacted by the autocollimator beam from bottom to top;

The steps to calculate the coordinates of the center of the sphere are as follows:

Step 2.1 Adjust the focal length of the autocollimator, let the autocollimator focus on the center of the sphere O ₂ , and rotate the upper air-floating turntable 360°, then the reflective cursor of the sphere center O ₂ on the ccd camera of the auto-collimator draw a circle, and then determine the z-axis coordinate of the spherical center O ₂ according to the structural size of the pneumatic adsorption head and the radius of curvature of the adsorbed spherical surface, as shown in formula (1):

in, is the z-axis coordinate of the spherical center O ₂ , d _x represents the diameter of the contact surface between the bottom end of the pneumatic adsorption head and the lens, L represents the distance from the contact surface to the origin O after the lens is adsorbed, and R ₂ represents the radius of curvature of the adsorbed mirror surface , the adsorbed mirror surface is called "sphere 2";

Step 2.2 Adjust the focal length of the autocollimator, let the autocollimator focus on the center of the sphere of O ₁ , and rotate the upper air-floating turntable by 360°, then the reflective cursor of the sphere center O ₁ on the ccd camera of the autocollimator draws A circle, at this time, the center of the lens can be calculated to be the exact χ, so as to determine the z-axis coordinate of the center of the sphere O ₁ as in formula (2):

in, is the z-axis coordinate of the spherical center O ₁ , R ₁ represents the radius of curvature of the lens spherical surface that is not adsorbed, and the lens spherical surface that is not adsorbed is called "sphere 1", d ₁₂ represents the thickness of the lens, χ represents the center deviation of the lens, cosχ represents the cosine value of the center bias χ;

Step 2.3 Calculate the coordinates of center 1 and center 2 in the offset coordinate system as follows: formulas (3) and (4):

Among them, the sphere centers O ₁ and O ₂ collected by the ccd camera twice respectively draw two circles on the reflection cursor on the autocollimator ccd camera, X _1.0 , X _1.180 , Y _1.0 and Y _1.180 represent the sphere center O respectively ₁ The coordinates of the four points corresponding to the circle in the positive x-axis, negative x-axis, positive y-axis and negative y-axis directions; X _2.0 , X _2.180 , Y _2.0 and Y _2.180 represent the center of the sphere O respectively ₂ The coordinate values of the four points corresponding to the circle corresponding to the positive direction of the x-axis, the negative direction of the x-axis, the positive direction of the y-axis and the negative direction of the y-axis;

β _T (1) represents the vertical axis magnification during the imaging process from the sphere center O ₁ to the detector target surface, β _T (2) represents the vertical axis magnification during the imaging process from the sphere center O ₂ to the detector target surface, representing the spherical surface The magnification of the sphere center O of ₂ relative to the imaging of sphere 1, Indicates the image distance when the center O ₂ of sphere 2 is imaged relative to sphere 1;

Step 3, use the 6-DOF parallel mechanism to realize rapid deviation adjustment. Steps 3.1 to 3.5 are a complete round of rapid deviation adjustment for the 6-DOF parallel mechanism. One round of deviation adjustment mainly includes the following steps:

(i=1,2; j=1,2,3,4,5) represents the position of the center of the sphere i after the jth offset adjustment is completed; respectively represent the coordinates of the center of the sphere i on the x, y and z axes after the jth offset adjustment is completed; T _Aj represents the motion matrix of the jth offset adjustment;

Step 3.1 Adjust the lens position in the horizontal plane composed of the x-axis and the y-axis, and the translation amount in the x-direction is The amount of translation in the y direction is Translate the center of the sphere O ₂ to the reference axis of the automatic deflection system, and the motion matrix of the six-degree-of-freedom parallel mechanism is shown in formula (5):

is the x-axis coordinate of the sphere center O ₂ in the offset coordinate system before the offset starts, is the y-axis coordinate of the sphere center O ₂ in the offset adjustment coordinate system before the offset adjustment starts, and the sphere center is obtained after the first adjustment

Step 3.2 The six-degree-of-freedom parallel mechanism rotates around the x-axis, and the rotation angle is θ ₂ , such that The connection line is parallel to the xz plane, and the motion matrix of the six-degree-of-freedom parallel mechanism is shown in formula (6):

θ ₂ is the optical axis of the lens The angle formed with the y-axis of the offset coordinate system, the calculation formula is as follows (7):

Step 3.3 The six-degree-of-freedom parallel mechanism moves along the y and z axes, and the amount of movement in the y direction is The amount of movement in the z direction is ΔZ _A3 , so that the third adjusted The line is in the xz plane, let back The position of the point; the motion matrix of the six-degree-of-freedom parallel mechanism is shown in formula (8):

The calculation formula of -ΔZ _A3 is as (9) and (10):

Step 3.4 The six-degree-of-freedom parallel mechanism rotates around the y-axis, and the rotation angle is θ ₁ , so that the adjusted The connection line is parallel to the yz plane, and the motion matrix of the six-degree-of-freedom parallel mechanism is shown in formula (11):

θ ₁ is the optical axis of the lens The angle formed with the x-axis of the offset coordinate system, the calculation formula is as follows (12):

Step 3.5 Move along the x and z axes, and the adjustment amount in the x axis direction is The adjustment amount in the z-axis direction is -ΔZ _A5 ; let the fifth adjustment The line coincides with the z-axis, and let back The position of the point, the motion matrix of the six-degree-of-freedom parallel mechanism is as formula (13):

The calculation formula of -ΔZ _A5 is as (14):

So far, from step 1 to step 3, the automatic bias adjustment method is completed.

The implementation process of the automatic deviation adjustment system of the present invention includes the following steps:

Step 1, to ensure that the coaxiality of "autocollimator, lower air-floating turntable rotating shaft, upper air-floating turntable rotating shaft" is within 3 microns during equipment installation;

Step II, the z-axis displacement stage is raised, and the automatic polarization adjustment module is lifted to facilitate the placement of the lens barrel;

Step III, place the lens barrel on the four-dimensional adjustment table and fasten it with the lens barrel clamp;

Step IV, adjust the position of the dial gauge measuring mechanism, so that the upper dial gauge and the lower dial gauge point to the rotation axis of the lower air-floating turntable, and let the two dial gauges contact the outer surface of the lens barrel at the same time, ready to measure the diameter of the lens barrel. circular runout tolerance;

In step V, the lower air-floating turntable rotates once, and the lens barrel axis is fitted according to the beating tolerance of the outer contour of the lens barrel measured by the two dial indicators, and the declination angle of the lens barrel axis in space is analyzed;

Step VI, by adjusting the two linear displacement stages and one adjustment stage of the four-dimensional adjustment stage, so that the axis of the lens barrel coincides with the reference axis of the automatic polarization adjustment system;

Step VII, the pneumatic adsorption head starts to work, and the lens is manually placed at the pneumatic adsorption head to be adsorbed;

Step VIII, use the automatic polarization adjustment method to complete the first polarization adjustment of the lens;

Step IX, measure the center deviation of the lens to see if it meets the accuracy requirements. If the center deviation is still large and exceeds the accuracy requirements, repeat step VIII; if the center deviation has met the accuracy requirements, continue to step X;

In step X, the z-axis displacement stage is lowered, and the lens is slowly put into the lens barrel. When the 6-DOF force sensor detects that the lens has touched the spacer, the movement is stopped immediately;

Step XI, manually use a glue dispenser to apply ultraviolet light curing adhesive on the circumference of the lens, and cure it with ultraviolet light to fix the lens; the automatic polarization adjustment module is moved up, and the next lens is ready to be installed;

So far, from step I to step XI, the implementation process of an optical lens-oriented six-degree-of-freedom parallel automatic polarization adjustment system has been completed.

beneficial effect

Compared with the prior art, a six-degree-of-freedom parallel automatic polarization adjustment system and method for optical lenses provided by the present invention has the following beneficial effects:

(A) Compared with the traditional automatic center deviation measurement equipment, the automatic polarization adjustment system of the present invention can not only realize the measurement of the center deviation of the lens, but also does not require manual adjustment when adjusting the lens, and has six degrees of freedom for automatic polarization adjustment. The parallel mechanism has high motion accuracy, which can basically meet the requirements of the adjustment accuracy after one-time adjustment of the lens. At the same time, the parallel mechanism can respond quickly, that is, the assembly is highly automated, which can greatly improve the lens assembly and adjustment efficiency;

(B) The polarization adjustment algorithm can measure the spherical center coordinates and center deviation of the mirror to be adjusted in real time, and adjust the lens according to the current measurement value. The measurement and adjustment are carried out crosswise until the adjustment meets the accuracy; , which can better ensure the accuracy of the adjustment;

(C) The input of the automatic offset adjustment algorithm is the spherical center coordinates of the mirror to be adjusted measured by the autocollimator, and the output is the adjustment amount of the six-degree-of-freedom parallel mechanism. The spherical center coordinates measured by the autocollimator directly reflect the center deviation, and the six-degree-of-freedom parallel mechanism is directly connected to the lens, so this polarization adjustment algorithm directly solves the lens adjustment and alignment problem with the center deviation as the objective function;

(D) This automatic polarization adjustment system proposes an inverted structure layout with the autocollimator on the bottom and the automatic polarization adjustment module on the top, which is beneficial to the assembly of subsequent lenses; Compared with the layout, this layout provides the convenience of operation space for the automatic polarization adjustment module;

(E) In the lens barrel adjustment module of the present invention, compared with the traditional adjustment platform, the adjustment platform can not only realize the fine adjustment of the angle, but also ensure that the mirror can The barrel always rotates around the center of the ball without offset errors during the leveling process; compared to the traditional leveling platform, this leveling platform has no offset error when adjusting the angle and has less adjustment times, and higher leveling efficiency.

Description of drawings

1 is a structural diagram of a six-degree-of-freedom parallel automatic polarization adjustment system oriented to an optical lens according to the present invention;

2 is a schematic diagram of a lens barrel adjustment module in a six-degree-of-freedom parallel automatic polarization adjustment system for optical lenses according to the present invention;

3 is a schematic diagram of a central polarization measurement module in a six-degree-of-freedom parallel automatic polarization adjustment system oriented to an optical lens according to the present invention;

4 is a schematic diagram of an automatic polarization adjustment module in a six-degree-of-freedom parallel automatic polarization adjustment system for optical lenses according to the present invention;

5 is a schematic diagram of solving the z-axis coordinates of the two spherical centers of the lens in a six-degree-of-freedom parallel automatic polarization adjustment method for an optical lens according to the present invention;

6 is a schematic diagram of the change process of the line connecting the two sphere centers in the polarization adjustment coordinate system in a six-degree-of-freedom parallel automatic polarization adjustment method for an optical lens according to the present invention.

FIG. 7 is a flow chart of an embodiment of an optical lens-oriented six-degree-of-freedom parallel automatic polarization adjustment method according to the present invention.

Illustration

Among them, 1-1 - lens barrel adjustment module, 1-2 - center deviation measurement module, 1-3 - automatic polarization adjustment module;

Among them, 2-1-dial indicator movement platform, 2-2-upper dial indicator, 2-3-lower indicator, 2-4-lens barrel, 2-5-lens barrel clamping mechanism, 2-6 - Four-dimensional adjustment table, 2-7 - lower air-floating turntable;

Among them, 3-1-autocollimator adjustment mechanism, 3-2-autocollimator, 3-3-45°reflector;

Among them, 4-1—Z-axis displacement stage, 4-2—upper air-floating turntable, 4-3—six degrees of freedom parallel mechanism, 4-4—six degrees of freedom force sensor, 4-5—pneumatic adsorption head.

Among them, OXYZ in Figure 5 constitutes the offset coordinate system, O _1B and O _2B are the actual spherical center positions of the two spherical surfaces, and O ₁ and O ₂ represent the theoretical spherical center positions, that is, the ideal position of the lens without center deviation; In the manual, O ₁ and O ₂ are uniformly replaced, χ represents the center deviation of the lens, dx is the diameter of the suction port of the pneumatic suction head, and L is the length of the pneumatic suction head;

Among them, OXYZ in Figure 6 is the offset coordinate system, Indicates that the lens obtains the spherical center position after the first adjustment, and θ ₁ is the optical axis of the lens The angle formed with the x-axis of the polarization coordinate system, θ ₂ is the optical axis of the lens The angle formed with the y-axis of the offset coordinate system;

FIG. 7 is a flow chart of the specific implementation of automatic polarization adjustment of the lens.

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

Example 1

Referring to FIG. 1 , the optical adjustment system mainly includes three main parts: 1-1 lens barrel adjustment module, 1-2 center deviation measurement module and 1-3 automatic polarization adjustment module. Through the coordination and cooperation of various parts, a high degree of integration of the central deviation measurement and lens adjustment can be achieved.

Take the rotating shaft of the 4-2 upper air-floating turntable as the reference axis of the whole system, respectively ensure that the coaxiality between the 2-7 lower air-bearing turntable and the 3-2 autocollimator optical axis and the reference axis is within plus or minus 3 microns .

Referring to FIG. 2 , the pose of the lens barrel is adjusted through the lens barrel adjustment module 1-1, which includes a dial gauge measuring mechanism and a four-dimensional adjustment stage 2-6. Place the lens barrel on the 2-6 four-dimensional adjustment table, fix the lens barrel with the 2-5 lens barrel clamping mechanism, adjust the position of the dial indicator by adjusting the displacement table of the dial indicator measuring mechanism, so that the head of the dial indicator can be adjusted. Contact the busbar of the lens barrel, among which, the 2-3 lower dial indicator needs to be exactly 40mm away from the table, that is, the 2-3 lower dial indicator just points to the center of the 2D adjustment platform contacting the spherical surface, then during the adjustment process, in the There will be no horizontal displacement at 2-3 lower dial gauge heights.

2-7 Lower the air-floating turntable for one rotation, and the two dial indicators measure the readings. According to the beating of the dial indicators, the offset vector of the mechanical axis of the lens barrel can be judged, so that the 2-6 four-dimensional adjustment table can be used to adjust the posture of the lens barrel. Adjust so that the mechanical axis of the lens barrel coincides with the reference axis of the system.

Referring to Figure 3, place the 3-2 autocollimator assembly horizontally under the workbench, and adjust the 3-1 adjustment screw and 3-3 reflector of the collimator so that the optical axis of the collimator and the reference axis of the system are Concentricity is within 3 microns. Input the curvature radius, material, lens spacing, thickness and other information of each lens to be assembled into the computer, and calculate the theoretical position of the curvature center of each mirror surface.

Referring to FIG. 4 , the polarization adjustment of the lens is completed by using 1-3 automatic polarization adjustment modules. Let the 4-1Z-axis stage rise, and lift the polarization adjustment module to facilitate the placement of the lens barrel. The pneumatic suction head starts to work, manually place the lens on the 4-5 pneumatic suction head to absorb it,

Referring to Figure 5, according to the suction port diameter dx and length L of the pneumatic suction head, and the spherical radius R ₂ of the lens spherical surface 2, the z-axis coordinate Z _{O 2} of the spherical center O 2 can be calculated; The spherical radius R ₁ of the spherical surface 2 is calculated, and the z-axis coordinate Z _O1 of the spherical center O ₁ is calculated; then the 3-2 autocollimator is controlled by the computer, and the focal length of the The focus of the collimator is focused on the theoretical sphere center position of the measured sphere; 4-2 The upper air-floating turntable drives the lens to rotate once, if the lens is deviated from the center, a circular trajectory will appear on the photosensitive surface of the CCD camera of the collimator , the 3-2 autocollimator can measure the actual spherical center position of the measured spherical surface according to the circular trajectory data; adjust the focal length of the 3-2 autocollimator again, repeat the above steps, and measure the actual spherical surface of the same lens The position of the center of the sphere; the optical axis of the tested lens is fitted by the computer, and the center deviation value of the lens is calculated;

Referring to Fig. 6, after calculating the coordinates of the two spherical centers of the single lens, the actual position O ₁ O ₂ of the spherical center is obtained, and the six-degree-of-freedom parallel mechanism is used to realize rapid deviation adjustment. First, the spherical center O ₂ is translated to automatic deviation adjustment. On the reference axis of the system, the state shown in Figure 6 is obtained; then the six-degree-of-freedom parallel mechanism is used to adjust the pose of the lens, so that the line connecting the two spherical centers finally coincides with the reference axis of the automatic polarization adjustment system;

Referring to Figure 7, after completing one round of deviation adjustment with the six-degree-of-freedom parallel mechanism, it is necessary to measure the center deviation of the lens to see if it meets the requirements. If the center deviation is still relatively large and exceeds the accuracy requirements, repeat the deviation adjustment steps; If the accuracy requirements have been met, the 4-1Z-axis stage is lowered, and the lens is put into the lens barrel. During this process, if the lens touches the lens barrel, the six-degree-of-freedom force sensor will generate a signal feedback to the system, and stop 4 - Downward motion of the 1Z-axis stage.

After the lens is placed in the installation position of the lens barrel, measure the center deviation of the lens again to see if it meets the requirements. If it does not meet the requirements, repeat the polarization adjustment steps. UV light curing, fixed lens; automatic polarization adjustment module moves up, ready to install the next lens.

To sum up, the above are only preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims (8)

1. A six-degree-of-freedom parallel automatic polarization adjustment system for an optical lens, characterized in that: the automatic polarization adjustment system realizes the integration of the center polarization measurement and the automatic adjustment of the lens, and not only can realize the rapid measurement of the center polarization of the lens, but also Based on the measurement results of the central deviation, an automatic polarization adjustment method using a six-degree-of-freedom parallel structure to realize the lens polarization adjustment is proposed. For deviation adjustment, re-measure the center deviation to verify whether the deviation adjustment result can meet the requirements. If it does not meet the accuracy requirements, it is necessary to re-fit the optical axis and adjust the deviation again until the accuracy meets the requirements, which can ensure the deviation adjustment accuracy of the lens. meet the requirements; Among them, the automatic polarization adjustment system is mainly composed of the lens barrel adjustment module, the center deviation measurement module and the automatic polarization adjustment module; the automatic polarization adjustment system can realize the height integration of the center deviation measurement and the lens adjustment; Among them, the lens barrel adjustment module includes a lower air-floating turntable, a four-dimensional adjustment table, a lens barrel clamping mechanism and a dial indicator measuring mechanism; the dial indicator measuring mechanism includes a dial indicator motion platform, an upper dial indicator, and a lower dial indicator; The lower air-floating turntable is fixed on the equipment worktable, the four-dimensional adjustment table is fixed on the lower air-floating turntable, and the dial indicator measuring mechanism is fixed on the equipment worktable; the lower air-floating turntable has a central through hole, and the diameter of the through hole is The through hole is located at the shaft of the lower air-floating turntable, so that the light beam can pass through the lower air-floating turntable; The center deviation measurement module mainly includes an autocollimator adjustment mechanism, an autocollimator and a 45° reflector; when the autocollimator is installed, the position and attitude of the autocollimator and the 45° reflector are adjusted to ensure autocollimation. The coaxiality between the optical axis of the instrument and the reference axis of the system; the automatic deviation adjustment module mainly includes a z-axis displacement stage, an upper air-floating turntable, a 6-DOF parallel mechanism, a 6-DOF force sensor and a pneumatic adsorption head; the connection methods of the five parts are: : The z-axis stage is placed vertically, and its motion axis is parallel to the system reference axis; the upper air-floating turntable is fixedly connected to the z-axis stage through an adapter plate, and the rotation axis of the upper air-floating turntable and the system reference axis must be ensured. coaxiality at Inside; the base of the 6-DOF parallel mechanism and the upper air-floating turntable are fixedly connected through the transfer shaft, the 6-DOF parallel mechanism is placed upside down, and the coaxiality between the z-axis of the 6-DOF parallel mechanism and the system reference axis is guaranteed to be within within; one end of the six-degree-of-freedom force sensor is fixedly connected to the working surface of the six-degree-of-freedom parallel mechanism, and the geometric axis of the six-degree-of-freedom force sensor and the system reference axis are guaranteed to be within the same coaxiality. One end of the pneumatic suction head is fixedly connected with the six-degree-of-freedom force sensor, and the geometric axis of the pneumatic suction head and the coaxiality of the system reference axis are guaranteed to be within within. 2. A six-degree-of-freedom parallel automatic polarization adjustment system for optical lenses as claimed in claim 1, characterized in that: the reference axis of the automatic polarization adjustment system is specified as the rotation axis of the lower air-floating turntable in the lens barrel adjustment module; for A single lens with two spherical surfaces, and the line connecting the two spherical centers is the optical axis of the lens; Through-hole diameter of the lower air-floating turntable The range is arrive 3. The six-degree-of-freedom parallel automatic polarization adjustment system for optical lenses according to claim 1, wherein the four-dimensional adjustment stage in the lens barrel adjustment module comprises two linear displacement stages, an adjustment stage and a mirror Tube fixture; the movement axes of the two linear displacement stages are stacked vertically with each other in space, the adjustment platform is fixed on the two linear displacement platforms, and the lens barrel clamp is fixed on the adjustment platform; the center of the four-dimensional adjustment platform has a diameter of The through hole of the 4D adjustment table is to allow the light beam to pass through the 4D adjustment stage. Considering that the solid part without the through hole may obstruct the optical path during the movement of the linear stage, the through hole of the 4D adjustment stage is larger than that of the lower air-floating turntable. ; The adjustment platform mainly includes the working plate and the lower base plate; the rotating contact surface between the working plate and the lower base plate is a spherical surface, and there will be no horizontal displacement at the center of the sphere when leveling. It is just away from the table h, that is, the lower dial indicator just points to the center of the sphere where the adjustment platform contacts the spherical surface, then during the deviation adjustment process, there will be no horizontal displacement at the height of the lower dial indicator, so there will be no horizontal displacement when adjusting the angle. , realizes the separate adjustment of angle and offset, and avoids the error in principle; The dial gauge measuring mechanism mainly includes the upper dial gauge, the lower dial gauge, the slide rail, and the x-y two-dimensional translation stage; The connection method of the above four parts is as follows: both the upper dial indicator and the lower dial indicator are locked on the slide rail by screws to ensure that the measurement axes of the upper dial indicator and the lower dial indicator are in the same vertical plane; The screws are fixed on the x-y two-dimensional translation stage. 4. a kind of six-degree-of-freedom parallel automatic polarization adjustment system facing optical lens as claimed in claim 3, is characterized in that: The diameter of the center through hole of the four-dimensional adjustment table The range is For ease of manual adjustment, the adjustment platform is driven by a fine thread marked with a scale. 5 . The six-degree-of-freedom parallel automatic polarization adjustment system of claim 3 , wherein the distance between the lower dial indicator and the table h is 40mm to 60mm. 6 . 6. The six-degree-of-freedom parallel automatic polarization adjustment system for optical lenses as claimed in claim 1, characterized in that: The adjustment mechanism of the autocollimator includes a support plate, three screw adjustment mechanisms, the support plate is placed horizontally on the rack; the screw adjustment mechanism consists of three screws and a metal plate, and a part of the metal plate is connected to the rack through two screws Fixed connection, the other part of the metal plate is fixed with the support plate by a screw, and the position of the support plate on the rack can be adjusted by adjusting the screw; two screw adjustment mechanisms are arranged on both sides of the support plate, and one screw adjustment mechanism is arranged on the end face of the support plate ; The auto-collimator is placed horizontally on the pallet, and the end of the auto-collimator is fixed with a CCD camera; the 45° reflector is used to turn the beam, and the horizontal light of the collimator is turned into a vertical light. 7. A six-degree-of-freedom parallel automatic polarization adjustment method oriented to an optical lens, characterized in that: it mainly includes collecting data, calculating spherical center coordinates and fast adjustment; Step 1. Collect data, and collect parameters such as curvature radius, diameter, material, thickness, lens interval and inner diameter of the lens barrel of the lens to be adjusted in advance; Step 2. Determine the spatial coordinates of the spherical center of the lens to be adjusted by performing geometric calculation through the collected data; Among them, assuming that the lens to be adjusted is two spherical single lenses, the two spherical center coordinates corresponding to the two spherical single lenses are calculated as formulas (1) and (2): The calculated spherical center coordinate values are all values in the offset adjustment coordinate system, and the offset adjustment coordinate system is specified as: The x and y axes of the offset adjustment coordinate system coincide with the x and y axes of the autocollimator itself, the z axis of the offset adjustment coordinate system is vertically upward and coincides with the reference axis of the automatic offset adjustment system, and the z axis of the offset adjustment coordinate system The origin is set as the intersection of the first spherical surface of the first lens contacted by the autocollimator beam from bottom to top; The steps to calculate the coordinates of the center of the sphere are as follows: Step 2.1 Adjust the focal length of the autocollimator, let the autocollimator focus on the center of the sphere O ₂ , and rotate the upper air-floating turntable 360°, then the reflective cursor of the sphere center O ₂ on the ccd camera of the auto-collimator draw a circle, and then determine the z-axis coordinate of the spherical center O ₂ according to the structural size of the pneumatic adsorption head and the radius of curvature of the adsorbed spherical surface, as shown in formula (1): in, is the z-axis coordinate of the spherical center O ₂ , d _x represents the diameter of the contact surface between the bottom end of the pneumatic adsorption head and the lens, L represents the distance from the contact surface to the origin O after the lens is adsorbed, and R ₂ represents the radius of curvature of the adsorbed mirror surface , the adsorbed mirror surface is called "sphere 2"; Step 2.2 Adjust the focal length of the autocollimator, let the autocollimator focus on the center of the sphere of O ₁ , and rotate the upper air-floating turntable by 360°, then the reflective cursor of the sphere center O ₁ on the ccd camera of the autocollimator draws A circle, at this time, the center of the lens can be calculated to be the exact χ, so as to determine the z-axis coordinate of the center of the sphere O ₁ as in formula (2): in, is the z-axis coordinate of the spherical center O ₁ , R ₁ represents the radius of curvature of the lens spherical surface that is not adsorbed, and the lens spherical surface that is not adsorbed is called "sphere 1", d ₁₂ represents the thickness of the lens, χ represents the center deviation of the lens, cosχ represents the cosine value of the center bias χ; Step 2.3 Calculate the coordinates of center 1 and center 2 in the offset coordinate system as follows: formulas (3) and (4): Among them, the sphere center 1 and the sphere center 2 are represented by O ₁ and O ₂ respectively; the sphere centers O ₁ and O ₂ collected by the ccd camera twice respectively draw two circles on the reflection cursor on the autocollimator ccd camera, X _1.0 , X _1.180 , Y _1.0 and Y _1.180 respectively represent the coordinate values of the four points corresponding to the circle corresponding to the sphere center O ₁ in the positive direction of the x-axis, the negative direction of the x-axis, the positive direction of the y-axis and the negative direction of the y-axis; X _2.0 , X _2.180 , Y _2.0 and Y _2.180 respectively represent the coordinate values of the four points corresponding to the circle corresponding to the sphere center O ₂ in the positive direction of the x-axis, the negative direction of the x-axis, the positive direction of the y-axis and the negative direction of the y-axis; β _T (1) represents the vertical axis magnification during the imaging process from the sphere center O ₁ to the detector target surface, β _T (2) represents the vertical axis magnification during the imaging process from the sphere center O ₂ to the detector target surface, representing the spherical surface The magnification of the sphere center O of ₂ relative to the imaging of sphere 1, Indicates the image distance when the center O ₂ of sphere 2 is imaged relative to sphere 1; In step 3, the six-degree-of-freedom parallel mechanism is used to realize rapid deviation adjustment. Specifically, through steps 3.1 to 3.5, a complete round of rapid deviation adjustment is realized by the six-degree-of-freedom parallel mechanism; one round of deviation adjustment mainly includes the following steps: Indicates the position of the center of the sphere i after the jth offset adjustment is completed; respectively represent the coordinates of the center of the sphere i on the x, y and z axes after the jth offset adjustment is completed; T _Aj represents the motion matrix of the jth offset adjustment; Step 3.1 Adjust the lens position in the horizontal plane composed of the x-axis and the y-axis, and the translation amount in the x-direction is The amount of translation in the y direction is Translate the center of the sphere O ₂ to the reference axis of the automatic deflection system, and the motion matrix of the six-degree-of-freedom parallel mechanism is shown in formula (5): is the x-axis coordinate of the sphere center O ₂ in the offset coordinate system before the offset starts, is the y-axis coordinate of the sphere center O ₂ in the offset adjustment coordinate system before the offset adjustment starts, and the sphere center is obtained after the first adjustment Step 3.2 The six-degree-of-freedom parallel mechanism rotates around the x-axis, and the rotation angle is θ ₂ , such that The connection line is parallel to the xz plane, and the motion matrix of the six-degree-of-freedom parallel mechanism is shown in formula (6): θ ₂ is the optical axis of the lens The angle formed with the y-axis of the offset coordinate system, the calculation formula is as follows (7): Step 3.3 The six-degree-of-freedom parallel mechanism moves along the y and z axes, and the amount of movement in the y direction is The amount of movement in the z direction is ΔZ _A3 , so that the third adjusted The line is in the xz plane, let back The position of the point; the motion matrix of the six-degree-of-freedom parallel mechanism is shown in formula (8): The calculation formula of -ΔZ _A3 is as (9) and (10): Step 3.4 The six-degree-of-freedom parallel mechanism rotates around the y-axis, and the rotation angle is θ ₁ , so that the adjusted The connection line is parallel to the yz plane, and the motion matrix of the six-degree-of-freedom parallel mechanism is shown in formula (11): θ ₁ is the optical axis of the lens The angle formed with the x-axis of the offset coordinate system, the calculation formula is as follows (12): Step 3.5 Move along the x and z axes, and the adjustment amount in the x axis direction is The adjustment amount in the z-axis direction is -ΔZ _A5 ; let the fifth adjustment The line coincides with the z-axis, and let back The position of the point, the motion matrix of the six-degree-of-freedom parallel mechanism is as formula (13): The calculation formula of -ΔZ _A5 is as (14): So far, from step 1 to step 3, the automatic bias adjustment method is completed. 8. The six-degree-of-freedom parallel automatic polarization adjustment system for optical lenses as claimed in claim 1, wherein the implementation process of the automatic polarization adjustment system comprises the following steps: Step 1, to ensure that the coaxiality of "autocollimator, lower air-floating turntable rotating shaft, upper air-floating turntable rotating shaft" is within 3 microns during equipment installation; Step II, the z-axis displacement stage is raised, and the automatic polarization adjustment module is lifted to facilitate the placement of the lens barrel; Step III, place the lens barrel on the four-dimensional adjustment table and fasten it with the lens barrel clamp; Step IV, adjust the position of the dial gauge measuring mechanism, so that the upper dial gauge and the lower dial gauge point to the rotation axis of the lower air-floating turntable, and let the two dial gauges contact the outer surface of the lens barrel at the same time, ready to measure the diameter of the lens barrel. circular runout tolerance; In step V, the lower air-floating turntable rotates once, and the lens barrel axis is fitted according to the beating tolerance of the outer contour of the lens barrel measured by the two dial indicators, and the declination angle of the lens barrel axis in space is analyzed; Step VI, by adjusting the two linear displacement stages and one adjustment stage of the four-dimensional adjustment stage, so that the axis of the lens barrel coincides with the reference axis of the automatic polarization adjustment system; Step VII, the pneumatic adsorption head starts to work, and the lens is manually placed at the pneumatic adsorption head to be adsorbed; Step VIII, use the automatic polarization adjustment method to complete the first polarization adjustment of the lens; Step IX, measure the center deviation of the lens to see if it meets the accuracy requirements. If the center deviation is still large and exceeds the accuracy requirements, repeat step VIII; if the center deviation has met the accuracy requirements, continue to step X; In step X, the z-axis displacement stage is lowered, and the lens is slowly put into the lens barrel. When the 6-DOF force sensor detects that the lens has touched the spacer, the movement is stopped immediately; Step XI, manually use a glue dispenser to apply ultraviolet light curing adhesive on the circumference of the lens, and cure it with ultraviolet light to fix the lens; the automatic polarization adjustment module is moved up, and the next lens is ready to be installed; So far, from step I to step XI, the implementation process of an optical lens-oriented six-degree-of-freedom parallel automatic polarization adjustment system has been completed.