CN110940497A

CN110940497A - An optical lens athermalization test device

Info

Publication number: CN110940497A
Application number: CN201911404009.8A
Authority: CN
Inventors: 季荣
Original assignee: Maolai (Nanjing) Instrument Co Ltd
Current assignee: Maolai (Nanjing) Instrument Co Ltd
Priority date: 2019-12-31
Filing date: 2019-12-31
Publication date: 2020-03-31
Anticipated expiration: 2039-12-31
Also published as: CN110940497B

Abstract

The invention discloses an optical lens athermalization test device, comprising a heating and heat preservation device for heating and heat preservation of a lens to be tested, and an image detection system for image detection; the image detection system includes a light source for generating a light source. The target generator and the image receiver for receiving the detection light, the image receiver is connected to the computer through a communication cable; the target generator, the lens to be tested and the image receiver are coaxial, and the light sent by the target generator passes through the lens to be tested by The image receiver receives. In the present invention, the lens to be measured can be heated and kept warm by the heating and heat preservation device, so that the lens is at different ambient temperatures, so as to carry out the measurement under different ambient temperatures; the movement device is used to control the displacement of the image receiver, so as to realize the collection of images at different positions ( Perform imaging acquisition at different positions at the corresponding temperature, and finally obtain the influence of the temperature on the imaging effect of the lens).

Description

Optical lens athermalization testing device

Technical Field

The invention relates to a athermalization testing device for an optical lens, and belongs to the field of optical detection.

Background

Athermalization is a special requirement in the design of optical lenses, and particularly in the fields of space technology, vehicle-mounted lenses and the like, the working temperature of the lenses is greatly changed, and the focal length and the imaging definition of the lenses in the temperature range need to be kept unchanged or changed slightly. Athermal means can be divided into active and passive athermal means. The active athermalization technology is used for realizing that the optical image quality is not influenced when the temperature changes by adopting a preset automatic adjusting device. The passive athermalization is to consider the influence of temperature change on the lens and the mechanical structure in the design process, and to make the changes offset each other through optimization, thereby achieving the unchanged image quality.

The athermalization performance of the lens can be generally simulated and analyzed through design software, but the simulated analysis and the actual situation have difference due to the tolerance influence of actual materials and machining assembly. Therefore, the lens needs to measure the defocusing and the image quality of the lens at different temperatures, and parameters are provided for active athermal adjustment.

Disclosure of Invention

The purpose of the invention is as follows: the invention aims to solve the technical problem of providing an optical lens athermalization testing device which can generate corresponding testing temperature, automatically complete image acquisition and optical parameter measurement and can be used for detecting the imaging quality and the defocusing amount of a lens at high and low temperatures.

In order to achieve the purpose, the invention adopts the technical scheme that:

an optical lens athermalization testing device comprises a heating and heat-insulating device for heating and insulating a lens to be tested and an image detection system for detecting images; the image detection system comprises a target generator for generating a light source and an image receiver for receiving detection light, wherein the image receiver is connected with a computer through a communication cable; the target generator, the lens to be detected and the image receiver are coaxial, and light rays sent by the target generator penetrate through the lens to be detected and are received by the image receiver.

The heating and heat-insulating device comprises a heat-insulating pipeline, and a heating belt for heating or insulating the heat-insulating pipeline is wrapped outside the heat-insulating pipeline; the temperature controller is connected with the heating belt to control the heating belt to work; the lens to be tested is fixedly arranged in the heat insulation pipeline and is coaxial with the heat insulation pipeline; and temperature sensors are respectively arranged on the inner wall of the heat-insulating pipeline and the outer side of the lens to be measured, and the temperature sensors are connected with a temperature controller through cables.

The system comprises a motion control device, a position sensor and a control device, wherein the motion control device comprises a one-dimensional motion platform and the position sensor is used for detecting the position change of an image receiver; the image receiver is fixed on the one-dimensional moving platform and is driven by the one-dimensional moving platform to move along the axial direction.

And window glass is arranged in the heat-insulating pipeline relative to the front end of the lens to be detected.

The position sensor comprises a fixed end and a probe, wherein the fixed end is fixed on the image receiver, and the probe is in contact with the end face of the lens to be measured; an elastic device is arranged between the probe and the fixed end, and the probe extends out of or retracts into the fixed end along with the position change between the lens to be detected and the image receiver; the position sensor is connected with the computer through a cable.

Has the advantages that: the lens to be measured can be heated and insulated through the heating and insulating device, so that the lens is at different environmental temperatures, and the measurement at different environmental temperatures is carried out; the movement device is adopted to carry out displacement control on the image receiver, so that the acquisition of images at different positions is realized; the detection device and the heating device are integrated, so that the measurement process is simplified, the measurement space is saved (the equipment is small in size), and the defocusing variable quantity can be detected in real time.

Drawings

FIG. 1 is a schematic diagram of a system structure of an athermal test apparatus for an optical lens according to the present invention;

FIG. 2 is a graph of contrast and movement of an image measured by the athermal test apparatus for an optical lens according to the present invention;

fig. 3 is a graph showing the temperature measured by the athermal test apparatus for an optical lens according to the present invention and the variation curve of the rear lens intercept.

Detailed Description

The technical solution of the present invention is further explained with reference to the accompanying drawings and specific embodiments.

As shown in fig. 1 to 3, the optical lens athermalization testing device of the present invention includes a heating and heat-insulating device for heating and insulating a lens 104 to be tested (for changing and maintaining an ambient temperature of the lens 104 to be tested, and measuring the temperature of the lens and the ambient temperature in real time by a temperature controller), and further includes an image detection system for performing image detection (the image detection system is used for detecting a resolution of lens imaging to find an optimal imaging position of the lens); the image detection system comprises an object generator 106 for generating light source and an image receiver 107 for receiving detection light, wherein the image receiver 107 is connected with an external computer 110 through a communication cable; the target generator 10+, the lens 104 to be measured and the image receiver 107 are coaxial, and light rays sent by the target generator 106 pass through the lens 104 to be measured and are received by the image receiver 107.

The target generator 106 and the image receiver 107 are located on the optical axis of the test lens 104, on both sides of the lens 104, respectively. The light beam generated by the target generator 106 is focused and imaged on an image surface position through the lens 104, the objective lens of the image receiver 107 is also focused on the image surface position, the image is magnified and imaged on the camera through the objective lens, and the image is input into the computer 110 to be analyzed and calculated for image contrast. The image receiver 107 is located on the one-dimensional linear motion platform 108, and can move back and forth along the optical axis direction of the measured lens 104 to obtain the image contrast at different positions. The position sensor 109 (for detecting defocus variation) includes a fixed end and a probe, the fixed end of the position sensor 109 is fixedly connected with the image receiver 107, and the probe of the position sensor 109 is in contact with the right flange surface of the lens 104. When the image receiver 107 moves back and forth for scanning, the position sensor 109 can accurately measure the distance change between the flange surface of the lens 104 and the image receiver 107. The image receiver 107 can move back and forth along the optical axis of the lens to scan images at different positions, and the computer analyzes the contrast of the images to generate a curve relation between the contrast and the movement amount, and judges the position with the maximum image contrast (the clearest image).

The lens 104 is held in a heat-insulating pipe 102, and the flange surface of the lens 104 is fixed with the inner wall of the pipe 102. The lens 104 has a window 105 on the left side thereof for allowing the light beam generated by the target generator 106 to enter the lens 104 while sealing the surrounding environment therein for heat preservation. The heat preservation pipeline 102 is wrapped by a layer of heating belt 101, and the heating belt 101 is controlled by the temperature controller 100 to heat or preserve heat. The temperature controller 100 is connected with two temperature sensors 103, which are respectively positioned on the inner wall of the heat preservation pipeline 102 and the outer wall of the lens 104, and measures the temperature of the lens and the ambient environment in real time.

The optical lens athermalization testing device specifically comprises the following detection steps:

the method comprises the following steps: a specified lens temperature is set in the temperature controller 100, and the temperature controller 100 controls the heating belt 101 to heat according to temperature information measured by the temperature sensor 103 in real time; when the temperature of the lens 104 reaches the set temperature, the controller 100 controls the heating belt 101 to keep the temperature for a period of time, so as to ensure that the overall temperature of the lens 104 tends to be constant;

step two: the one-dimensional motion platform 108 drives the image receptor 107 to scan and collect an image according to a preset step length and a preset moving range, the image is analyzed by the computer 110 to obtain a curve of the contrast and the moving amount of the image, as shown in fig. 2, and the motion platform 108 is controlled to move to the optimal position of the contrast; obtaining the defocusing amount at the corresponding temperature;

step three: and recording the information of the image contrast and the position sensor, and calculating the defocus amount through the curve of the image contrast and the movement amount.

And setting a new temperature for the lens to be measured through the temperature controller 100, and repeating the steps. And obtaining the curve of the image contrast and the movement amount at the new temperature and the defocus amount at the temperature. Namely, a plurality of different temperatures are set, the measurement steps are repeated, the change of the defocusing amount at different temperatures can be obtained, and a curve of the temperature and the change of the rear intercept of the lens can be drawn, as shown in fig. 3. The curve reflects the defocusing and image quality change of the optical lens along with the change of the working temperature.

Claims

1. An optical lens athermalization test device is characterized in that: it comprises a heating and heat preservation device for heating and heat preservation for the lens to be tested, and also includes an image detection system for image detection; The target generator of the light source and the image receiver for receiving the detection light, the image receiver is connected to the computer through a communication cable; the target generator, the lens to be tested and the image receiver are coaxial, and the light sent by the target generator passes through the lens to be tested Then received by the image receiver.

2 . The optical lens athermalization test device according to claim 1 , wherein the heating and heat preservation device comprises a heat preservation pipe, and the heat preservation pipe is wrapped with a heating tape for heating or heat preservation of the heat preservation pipe; further comprising: 3 . a temperature controller, the temperature controller is connected with the heating belt to control the operation of the heating belt; the lens to be measured is fixedly installed in the heat preservation pipe and coaxial with the heat preservation pipe; the inner wall of the heat preservation pipe and the outside of the lens to be measured are respectively provided with temperature sensors; The temperature sensor is connected to the temperature controller through a cable.

3. The optical lens athermalization test device according to claim 1, characterized in that: further comprising a motion control device, the motion control device comprising a one-dimensional motion platform and a position sensor for detecting the position change of the image receiver; The image receiver is fixed on the one-dimensional motion platform, and is driven by the one-dimensional motion platform to move in the axial direction.

4 . The athermalization test device for an optical lens according to claim 2 , wherein a window glass is further provided inside the heat preservation pipe relative to the front end of the lens to be tested. 5 .

5. The optical lens athermalization test device according to claim 3, wherein the position sensor comprises a fixed end and a probe, the fixed end is fixed on the image receiver, and the probe touches the end face of the lens to be tested; the probe There is an elastic device between the fixed end and the probe, and the probe extends or retracts inside the fixed end according to the position change between the lens to be tested and the image receiver; the position sensor is connected with the computer through a cable.