Imaging type real-time stress birefringence measurement system

Abstract

The utility model discloses an imaging type real-time stress birefringence measuring system, which is characterized in that a plurality of imaging units comprising four pixels are arranged, and four polarizers of 0 degree, 45 degrees, 90 degrees and 135 degrees are respectively arranged at the positions of the four pixels of each imaging unit, so that light rays emitted by a light source module are imaged in a telecentric imaging lens, and then the light rays are reflected by the light source module. Light intensity images with four polarization directions of 0 degree, 45 degrees, 90 degrees and 135 degrees are obtained through shooting of the multi-phase linear polarization camera, frequent movement of a wave plate and a polarizer is avoided, meanwhile, arrangement of a multi-position camera is avoided, the use cost of stress measurement is reduced, and the stress measurement efficiency is improved; meanwhile, stress distribution in the glass material is accurately solved based on a least square method through light intensity images in different polarization directions, influence errors caused by an average signal of light intensity, image modulation and an uncertain reference phase to a stress measurement result in the stress measurement process are fully considered, and the accuracy of a final stress detection result is ensured.

Description

Technical Field

[0001] The utility model belongs to the technical field of stress measurement and relates to an imaging type real-time stress birefringence measurement system. Background Art

[0002] Existing internal stress detection of glass materials often relies on naked eye observation of stress measurement systems, using orthogonal polarization method or Sénarmonte compensation method, using human eyes to observe the internal stress of materials. With the continuous improvement of industrial technology, the accuracy requirements for testing the internal stress distribution of glass materials are increasing. The errors caused by the original manual estimation and manual operation cannot meet daily requirements.

[0003] With the technological innovation, the birefringence stress measurement system is subsequently used to detect the internal stress distribution of the glass. Although the detection accuracy is improved, the existing birefringence stress detection system is complex and requires a motor to control the polarization device to be synchronized with the computer image acquisition. The motor needs to be used to control the rotation angle of the wave plate. Every time the wave plate rotates an angle, a light intensity image needs to be collected in real time. There is a defect that the polarizer or wave plate needs to be moved frequently. In addition, in order to cooperate with the frequent movement of the wave plate and polarizer, the existing birefringence stress measurement system needs to set up multiple cameras to synchronously collect images, resulting in the existing birefringence stress system. The manufacturing cost and use cost are very high.

[0004] Therefore, in view of the defects of the existing birefringence stress system, such as the need to frequently move the wave plate or the polarizer and the high cost of use, the utility model discloses an imaging type real-time stress birefringence measurement system. Utility Model Content

[0005] The purpose of the utility model is to provide an imaging real-time stress birefringence measurement system, which can efficiently and accurately measure the stress distribution inside the glass material through a single exposure without moving the wave plate and the polarizer, while effectively reducing the use cost.

[0006] The utility model is realized by the following technical solutions:

[0007] An imaging type real-time stress birefringence measurement system comprises a light source module and a data acquisition module, wherein the light source module is used to provide circularly polarized light to the data acquisition module, and the data acquisition module comprises a multi-phase linear polarization camera and a telecentric imaging lens; the telecentric imaging lens is arranged at the shooting end of the multi-phase linear polarization camera, the multi-phase linear polarization camera comprises a plurality of array-arranged photodiodes, the photodiodes correspond to at least four array-arranged pixels, and polarizers of 0°, 45°, 90°, and 135° are respectively arranged at the four pixels; the multi-phase linear polarization camera also comprises a microlens, and the microlens is arranged at the incident end of the polarizer.

[0008] In order to better realize the utility model, further, an air gap nanowire grid is formed between the polarizer and the photodiode, and an anti-reflection coating is provided in the air gap nanowire grid.

[0009] In order to better implement the utility model, further, an imaging window glass is provided at the incident end of the telecentric imaging lens.

[0010] In order to better realize the utility model, further, the light source module includes a monochromatic LED light source, a light source telecentric lens, and a polarization filter. The light-emitting end of the monochromatic LED light source is connected to the light source telecentric lens. The output end of the light source telecentric lens is provided with a polarization filter. The polarization filter is used to filter the polarized light into circularly polarized light.

[0011] In order to better realize the utility model, further, the polarization filter unit includes a polarizer and a quarter wave plate, the polarizer is arranged at the exit end of the light source telecentric lens, and the quarter wave plate is arranged at the exit end of the polarizer.

[0012] In order to better implement the utility model, further, a quartz window glass is provided at the output end of the quarter wave plate.

[0013] Compared with the prior art, the utility model has the following advantages and beneficial effects:

[0014] The utility model arranges a plurality of imaging units including four pixels in a multi-phase linear polarization camera, and respectively arranges four polarizers of 0°, 45°, 90° and 135° at the positions of the four pixels of each imaging unit, so that after the light emitted by the light source module is imaged in the telecentric imaging lens, a light intensity image with four polarization directions of 0°, 45°, 90° and 135° is obtained by photographing with the multi-phase linear polarization camera, thereby avoiding frequent movement of wave plates and polarizers, and avoiding setting of multi-position cameras, thereby reducing the use cost of stress measurement and improving the efficiency of stress measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Schematic diagram of an imaging real-time stress birefringence measurement system;

[0016] Figure 2 is a structural schematic diagram of an imaging unit;

[0017] Figure 3 is a cross-sectional view of an imaging unit;

[0018] Figure 4 Schematic diagram of the planar arrangement of polarizers in four polarization directions.

[0019] Among them: 1-light source module; 2-data acquisition module; 11-monochromatic LED light source; 12-light source telecentric lens; 13-polarization filter; 14-quartz window glass; 21-multi-phase linear polarization camera; 22-telecentric imaging lens; 23-photodiode; 24-polarizer; 25-microlens; 26-imaging window glass; 131-polarizer; 132-quarter wave plate. DETAILED DESCRIPTION

[0020] The following detailed descriptions are all illustrative and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0021] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the utility model. As used herein, unless the utility model explicitly states otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0022] Embodiment 1:

[0023] An imaging real-time stress birefringence measurement system of this embodiment is as follows: Figure 1-Figure 4 As shown, it includes a light source module 1 and a data acquisition module 2, the light source module 1 is used to provide circularly polarized light to the data acquisition module 2, the data acquisition module 2 includes a multi-phase linear polarization camera 21 and a telecentric imaging lens 22; the telecentric imaging lens 22 is arranged at the shooting end of the multi-phase linear polarization camera 21, the multi-phase linear polarization camera 21 includes a plurality of imaging units arranged in an array, the imaging unit includes a photodiode 23, the photodiode corresponds to at least four pixels arranged in an array, and polarizers 24 with angles of 0°, 45°, 90°, and 135° are respectively arranged at the four pixels; the imaging unit also includes a microlens 25, and the microlens 25 is arranged at the incident end of the polarizer 24.

[0024] The light source module 1 is used to emit circularly polarized light to the telecentric imaging lens 22 in the data acquisition module 2, and to form an image in the telecentric imaging lens 22. The imaging in the telecentric imaging lens 22 is photographed by the multi-phase linear polarization camera 21, and the four polarizers 24 of 0°, 45°, 90°, and 135° are respectively set at the four pixel positions in each imaging unit, and then the light intensity images of the four polarization directions of 0°, 45°, 90°, and 135° are obtained after a single exposure. The multi-phase linear polarization camera 21 sends the obtained light intensity images of the four polarization directions of 0°, 45°, 90°, and 135° to an external computer, and solves the stress distribution in the sample to be tested according to the light intensity images of different polarizations.

[0025] The microlens 25 is arranged at the incident end of the polarizer 24. That is, the microlens 25, the polarizer 24, and the photodiode 23 are arranged in sequence along the incident direction of the light. This arrangement structure can effectively reduce polarization crosstalk and improve the extinction ratio.

[0026] Furthermore, an air gap nanowire grid is formed between the polarizer 24 and the photodiode, and an anti-reflection coating is provided in the air gap nanowire grid. By providing the anti-reflection coating, the flash and ghost effects during imaging can be suppressed.

[0027] Furthermore, an imaging window glass 26 is provided at the incident end of the telecentric imaging lens 22 .

[0028] Embodiment 2:

[0029] The imaging real-time stress birefringence measurement system of this embodiment is improved on the basis of embodiment 1, such as Figure 1 As shown, the light source module 1 includes a monochromatic LED light source 11, a light source telecentric lens 12, and a polarization filter 13. The light emitting end of the monochromatic LED light source 11 is connected to the light source telecentric lens 12. The output end of the light source telecentric lens 12 is provided with a polarization filter 13. The polarization filter 13 is used to filter the polarized light into circularly polarized light.

[0030] Furthermore, the polarization filter 13 includes a polarizer 131 and a quarter wave plate 132. The polarizer 131 is arranged at the exit end of the light source telecentric lens 12, and the quarter wave plate 132 is arranged at the exit end of the polarizer 131. The angle between the polarization axis of the polarizer 131 and the optical axis of the quarter wave plate 132 is 45°. The light emitted by the monochromatic LED light source 11 becomes linear polarized light after passing through the polarizer 131, and the linear polarized light becomes circular polarized light after passing through the quarter wave plate 132, and then reaches the telecentric imaging lens 22 for imaging after passing through the sample to be tested.

[0031] Furthermore, a quartz window glass 14 is provided at the output end of the quarter wave plate 132 .

[0032] The other parts of this embodiment are the same as those of the above-mentioned embodiment 1, and thus will not be described in detail.

[0033] The above are only preferred embodiments of the present invention and are not intended to limit the present invention in any form. Any simple modifications or equivalent changes made to the above embodiments based on the technical essence of the present invention fall within the protection scope of the present invention.

Claims

1. An imaging real-time stress birefringence measurement system, comprising a light source module (1) and a data acquisition module (2), characterized in that: The light source module (1) is used to provide circularly polarized light to the data acquisition module (2); the data acquisition module (2) comprises a multi-phase linear polarization camera (21) and a telecentric imaging lens (22); the telecentric imaging lens (22) is arranged at the shooting end of the multi-phase linear polarization camera (21); the multi-phase linear polarization camera (21) comprises a plurality of array-arranged photodiodes (23); the photodiodes (23) correspond to at least four array-arranged pixels; polarizers (24) with angles of 0°, 45°, 90°, and 135° are respectively arranged at the four pixels; the multi-phase linear polarization camera (21) further comprises a microlens (25); the microlens (25) is arranged at the incident end of the polarizer (24).

2. The imaging real-time stress birefringence measurement system according to claim 1, characterized in that: An air gap nanowire grid is formed between the polarizer (24) and the photodiode (23), and an anti-reflection coating is provided in the air gap nanowire grid.

3. The imaging real-time stress birefringence measurement system according to claim 2, characterized in that: An imaging window glass (26) is provided at the incident end of the telecentric imaging lens (22).

4. An imaging real-time stress birefringence measurement system according to any one of claims 1 to 3, characterized in that: The light source module (1) comprises a monochromatic LED light source (11), a light source telecentric lens (12), and a polarization filter (13); the light emitting end of the monochromatic LED light source (11) is connected to the light source telecentric lens (12); the light output end of the light source telecentric lens (12) is provided with a polarization filter (13); the polarization filter (13) is used to filter polarized light into circularly polarized light.

5. The imaging real-time stress birefringence measurement system according to claim 4, characterized in that: The polarization filter unit (13) comprises a polarizer (131) and a quarter-wave plate (132); the polarizer (131) is arranged at the exit end of the light source telecentric lens (12); and the quarter-wave plate (132) is arranged at the exit end of the polarizer (131).

6. The imaging real-time stress birefringence measurement system according to claim 5, characterized in that: A quartz window glass (14) is provided at the output end of the quarter-wave plate (132).

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