AR optical waveguide detection equipment calibration device

Abstract

The utility model relates to a calibration device for AR optical waveguide detection equipment, which comprises a waveguide carrying platform, a reflection optical flat arranged on the waveguide carrying platform, and a projection module and an imaging module arranged on the upstream of the reflection optical flat, and the positions of the projection module and the imaging module relative to the reflection optical flat are adjustable respectively. The projection module comprises a first light source module, a first light splitting module, a first lens group and a first image detection module which are arranged in sequence, and the imaging module comprises a second light source module, a second light splitting module, a second lens group and a second image detection module which are arranged in sequence. According to the utility model, by adopting the special projection module and the imaging module, external auxiliary tooling equipment such as a photoelectric auto-collimator and the like can be replaced to calibrate the initial position relation among the projection light path, the imaging light path and the waveguide carrying platform, and the calibration device has the advantages of simple structure, few tolerance transmission surfaces, high calibration precision and high calibration efficiency.

Description

Technical Field

[0001] The utility model relates to the technical field of AR optical waveguide detection equipment, in particular to an AR optical waveguide detection equipment calibration device. Background Art

[0002] As a lightweight AR technology solution, AR optical waveguide near-eye display technology has the potential to become a mainstream technology. With the gradual mass production of AR optical waveguides, the production quality control of AR optical waveguides has become increasingly important, and how to improve the repeatability of test results has become a problem that must be faced. Projection optical machines and imaging detection instruments are two core devices in AR optical waveguide detection. The projection optical machine projects the test pattern into the optical coupling area of ​​the AR optical waveguide, and the imaging detection instrument takes images near the eye movement range of the optical coupling end of the AR optical waveguide and detects the imaging quality. The spatial position relationship between the projection optical path, the imaging optical path, and the waveguide carrier requires a calibration method, otherwise the detection equipment will drift in position during long-term use, resulting in unlimited expansion of the measurement error.

[0003] Most existing technical solutions use external auxiliary devices for calibration, and can only calibrate some position parameters of the imaging optical path. For example, CN117232787A uses external auxiliary lasers and auxiliary cameras to calibrate the tilt angle of the optical axis of the detection camera. A few devices that can perform dual calibration of the projection optical path and the imaging optical path are relatively complex. For example, CN116952544A uses external auxiliary calibration tooling to calibrate the projection optical axis and the imaging optical axis. The number of components in the auxiliary tooling is relatively large. The more components there are, the more calibration errors will be accumulated. Utility Model Content

[0004] The problem to be solved by the utility model is to provide an AR optical waveguide detection equipment calibration device in view of the above-mentioned deficiencies existing in the prior art. The device can replace external auxiliary tooling equipment such as photoelectric autocollimator by adopting special projection and imaging structure to calibrate the initial position relationship among the projection optical path, imaging optical path and waveguide carrier. The device has the advantages of simple structure, few tolerance transfer surfaces, high calibration accuracy and high calibration efficiency.

[0005] The above utility model object of the utility model is achieved through the following technical solutions:

[0006] A calibration device for AR optical waveguide detection equipment comprises a waveguide carrier, a reflection flat crystal arranged on the waveguide carrier, and a projection module and an imaging module arranged upstream of the reflection flat crystal, wherein the positions of the projection module and the imaging module relative to the reflection flat crystal are respectively adjustable, the projection module comprises a first light source module, a first spectroscopic module, a first lens group and a first image detection module arranged in sequence, the first lens group and the first image detection module are respectively arranged on a transmission light path and a reflection light path of the first spectroscopic module, the imaging module comprises a second light source module, a second spectroscopic module, a second lens group and a second image detection module arranged in sequence, the second lens group and the second image detection module are respectively arranged on a reflection light path and a transmission light path of the second spectroscopic module.

[0007] By adopting the above technical solution, the light emitted by the first light source module in the projection module is transmitted through the first light splitting module to form a transmitted light which is sequentially transmitted through the first lens group, reflected by the reflection flat crystal, and transmitted twice by the first lens group, and then reflected by the first light splitting module to form a reflected light which is visually detected by the first image detection module, thereby forming a projection light path;

[0008] The light emitted by the second light source module in the imaging module is reflected by the second light splitting module to form reflected light, which is sequentially transmitted through the second lens group, reflected by the reflection flat crystal, and transmitted twice by the second lens group. The transmitted light formed by the second light splitting module is then visually detected by the second image detection module, thereby forming an imaging light path;

[0009] Based on this, in order to calibrate the initial position relationship between the projection optical path, imaging optical path and waveguide stage, the calibration of the optical axis is divided into two steps: calibration of the optical axis tilt angle of the reflection flat crystal and calibration of the XYZ position of the projection optical path and imaging optical path:

[0010] (1) Calibration of the optical axis tilt angle: When the waveguide stage tilts, the first image detection module and the second image detection module can capture the change of the central reflected light and infer the tilt amount. Since the positions of the projection module and the imaging module relative to the reflection flat crystal are adjustable, the orientations of the waveguide stage, the projection module and the imaging module can be adjusted synchronously. When the reflected light and the projected light coincide, it is recorded as the initial state of the optical axis tilt.

[0011] (2) Z-axis position calibration: The basis for Z-axis position calibration is that the positions of the first exit pupil diaphragm and the second exit pupil diaphragm must coincide with the surface of the reflective flat crystal. When the two do not coincide, part of the reflected light is blocked by the first exit pupil diaphragm or the second exit pupil diaphragm and cannot enter the first image detection module or the second image detection module. At this time, it is necessary to adjust the Z-axis position of the projection module and the imaging module to move them closer to or away from the surface of the reflective flat crystal so that the first exit pupil diaphragm and the second exit pupil diaphragm coincide with the reflective flat crystal. Under the above position relationship, the first image detection module and the second image detection module will detect the reflected light with the strongest brightness and record the Z-axis position of the projection light path and the imaging light path at this time as the initial state;

[0012] (3) XY axis position calibration: Move the projection module and the imaging module as a whole to the vicinity of the boundary of the reflective flat crystal in the X direction or the Y direction. At this time, the central brightness of the reflected image detected by the first image detection module and the second image detection module will be halved. The spatial XY two-dimensional coordinates of the projection module and the imaging module at this time are recorded as the initial state.

[0013] After the calibration steps of the optical axis, the initial relative positions of the projection optical path, imaging optical path and waveguide stage in the five-dimensional space can be uniquely determined. The waveguide stage is the only reference in the entire calibration process. The calibration process only accumulates the tolerance of one optical element, the reflective flat crystal, which has high calibration accuracy. The switching between the calibration process and the detection process only requires switching the reflective flat crystal hardware. It has the advantages of simple structure, few tolerance transfer surfaces, high calibration accuracy and high calibration efficiency.

[0014] The utility model is further configured as follows: it also includes a main control module, a first driving module and a second driving module, the signal input end of the main control module is respectively connected to the first image detection module and the second image detection module, and the signal output end is respectively connected to the first driving module and the second driving module, the projection module is arranged at the mobile end of the first driving module, and the imaging module is arranged at the mobile end of the first driving module.

[0015] By adopting the above-mentioned technical scheme, on the basis of visual detection based on the first image detection module and the second image detection module, the main control module can be further arranged to receive the visual detection signal and compare it with the set value, and then selectively control the action of the first driving module and the second driving module to complete the position adjustment of the projection module and the imaging module relative to the reflective flat crystal, thereby realizing automatic calibration of the optical axis.

[0016] The utility model is further configured as follows: the main control module is configured as a single chip microcomputer, a microprocessor, a control panel or a main control chip.

[0017] By adopting the above technical solution, the visual detection signal acquisition processing and drive signal control between the first image detection module and the second image detection module, the first drive module and the second drive module can be completed.

[0018] The utility model is further configured as follows: the waveguide carrier is configured as a one-dimensional slide, and the first drive module and the second drive module are each independently configured as a two-dimensional slide; or, the waveguide carrier is configured as a two-dimensional slide, and the first drive module and the second drive module are each independently configured as a one-dimensional slide; the moving direction of the one-dimensional slide and the two moving directions of the two-dimensional slide are perpendicular to each other.

[0019] By adopting the above technical solution, the one-dimensional slide preferably uses a linear guide rail, and the two-dimensional slide preferably uses a cross slide, so as to realize the translation and lifting of the projection module and the imaging module relative to the reflective flat crystal surface, thereby realizing automatic XYZ axis position calibration.

[0020] The utility model is further configured as follows: at least two of the waveguide carrier, the first driving module and the second driving module are independently configured as three-dimensional slide platforms.

[0021] By adopting the above technical solution, the three-dimensional slide preferably uses a rectangular coordinate robot or a six-axis robotic arm to achieve the translation and lifting of the projection module and the imaging module relative to the reflective flat crystal surface, thereby realizing automatic XYZ axis position calibration.

[0022] The utility model is further configured to include: a first exit pupil stop arranged between the reflective flat crystal and the first lens group, and a second exit pupil stop arranged between the reflective flat crystal and the second lens group.

[0023] By adopting the above technical solution, the Z-axis position calibration is based on the position of the first exit pupil diaphragm and the second exit pupil diaphragm to coincide with the surface of the reflective flat crystal, which is used to calibrate the Z-axis position in cooperation with the projection module and the imaging module respectively.

[0024] The utility model is further configured as follows: the first light source module comprises a first illumination light source and a first slide arranged in sequence, and the second light source module comprises a second illumination light source and a second slide arranged in sequence.

[0025] By adopting the above technical solution, the light emitted by the first illumination light source illuminates the first slide, the projection module is used to project the pattern on the first slide onto the reflective flat crystal, the light emitted by the second illumination light source illuminates the second slide, and the imaging module is used to project the pattern on the second slide onto the reflective flat crystal.

[0026] The utility model is further configured as follows: the first light splitting module and the second light splitting module are each independently configured as a light splitting prism.

[0027] By adopting the above technical solution, the beam splitter prism is achieved by coating a thin film structure on the inclined surface of a right-angle prism and then gluing it into a cubic structure, thereby controlling the transmittance and reflectance of light based on the principle of light interference.

[0028] The utility model is further configured as follows: the first lens group is configured as a projection lens, and the second lens group is configured as an imaging lens.

[0029] By adopting the above technical solution, light can be easily transmitted.

[0030] The utility model is further configured as follows: the first image detection module and the second image detection module are each independently configured as an image detector.

[0031] By adopting the above technical solution, the image detector detects the shape or internal structure of the object through the energy radiation from the object. Since the surface shape and internal structure of the object will modulate the spatial distribution of the radiation signal, the spatial distribution of the radiation from the object will naturally carry the image information of the surface or internal structure of the object. By converting the radiation distribution of the image into an electrical signal, the shape or internal structure of the detected object can be obtained.

[0032] To sum up, the beneficial technical effect of the utility model is: by adopting a special projection module and an imaging module, it can replace external auxiliary tooling equipment such as a photoelectric autocollimator to calibrate the initial position relationship between the projection optical path, the imaging optical path, and the waveguide carrier, and has the advantages of simple structure, few tolerance transfer surfaces, high calibration accuracy, and high calibration efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a structural schematic diagram of the calibration device of Example 1 of the utility model.

[0034] Figure 2 It is a structural schematic diagram of the calibration device of Example 2 of the utility model.

[0035] Figure 3 It is a structural schematic diagram of the calibration device of Example 3 of the utility model for calibrating the optical axis tilt angle.

[0036] Figure 4 It is a structural schematic diagram of the calibration device of Example 3 of the utility model for Z-axis position calibration.

[0037] Figure 5 It is a structural schematic diagram of the calibration device of Example 3 of the utility model for performing XY position calibration.

[0038] Figure 6 It is a schematic diagram of tolerance transfer during the calibration process of the calibration device of Example 3 of the utility model.

[0039] In the figure, LG1, projection module; 1, first illumination light source; 2, first slide; 3, first spectroscopic module; 4, first image detection module; 5, first lens group; 6, waveguide carrier; 7, reflection flat crystal; LG2, imaging module; 8, second lens group; 9, second slide; 10, second spectroscopic module; 11, second image detection module; 12, second illumination light source; 13, first exit pupil diaphragm; 14, second exit pupil diaphragm; 15, main control module; 16, first drive module; 17, second drive module. DETAILED DESCRIPTION

[0040] In order to make the technical means, creative features, objectives and functions achieved by the present invention clearer and easier to understand, the present invention is further described below in conjunction with the accompanying drawings and specific implementation methods.

[0041] Example 1: Reference Figure 1 , is an AR optical waveguide detection equipment calibration device disclosed in the utility model, comprising a waveguide stage 6, a reflection flat crystal 7 disposed on the waveguide stage 6, and a projection module LG1 and an imaging module LG2 arranged upstream of the reflection flat crystal 7. The positions of the projection module LG1 and the imaging module LG2 relative to the reflection flat crystal 7 are adjustable.

[0042] The projection module LG1 includes a first light source module, a first spectroscopic module 3, a first lens group 5 and a first image detection module 4 which are arranged in sequence. The first light source module includes a first illumination light source 1 and a first slide 2 which are arranged in sequence, the first spectroscopic module 3 is configured as a spectroscopic prism, the first lens group 5 is configured as a projection lens, the first image detection module 4 is configured as an image detector, and the first lens group 5 and the first image detection module 4 are respectively arranged on the transmission light path and the reflection light path of the first spectroscopic module 3.

[0043] The light emitted by the first illumination light source 1 illuminates the first slide 2. The light is transmitted through the first light splitting module 3 to form a transmitted light which is sequentially transmitted through the first lens group 5, reflected by the reflective flat crystal 7, and transmitted twice by the first lens group 5. The reflected light formed by the reflection of the first light splitting module 3 is then visually detected by the first image detection module 4. The projection module LG1 is used to project the pattern on the first slide 2 onto the reflective flat crystal 7, thereby forming a projection light path.

[0044] The imaging module LG2 includes a second light source module, a second light splitting module 10, a second lens group 8 and a second image detection module 11 arranged in sequence. The second light source module includes a second illumination light source 12 and a second slide 9 arranged in sequence, the second light splitting module 10 is configured as a light splitting prism, the second lens group 8 is configured as an imaging lens, the second image detection module 11 is configured as an image detector, and the second lens group 8 and the second image detection module 11 are respectively arranged on the reflected light path and the transmitted light path of the second light splitting module 10.

[0045] The light emitted by the second illumination light source 12 illuminates the second slide 9. The reflected light formed by the reflection of the light by the second light splitting module 10 is transmitted through the second lens group 8, reflected by the reflection flat crystal 7, and transmitted twice by the second lens group 8 in sequence. The transmitted light formed by the transmission of the light by the second light splitting module 10 is visually detected by the second image detection module 11. The imaging module LG2 is used to project the pattern on the second slide 9 onto the reflection flat crystal 7, thereby forming an imaging light path.

[0046] Example 2: Reference Figure 2 , is an AR optical waveguide detection equipment calibration device disclosed in the utility model, which is different from Example 1 in that it also includes a main control module 15, a first drive module 16 and a second drive module 17. Among them, the main control module 15 is configured as a single-chip microcomputer, a microprocessor, a control panel or a main control chip, and the first drive module 16 and the second drive module 17 are each independently configured as a three-dimensional slide (six-axis robotic arm).

[0047] At the same time, the signal input end of the main control module 15 is respectively connected to the first image detection module 4 and the second image detection module 11, and the signal output end is respectively connected to the first driving module 16 and the second driving module 17. The projection module LG1 is arranged at the mobile end of the first driving module 16, and the imaging module LG2 is arranged at the mobile end of the first driving module 16.

[0048] On the basis of visual detection based on the first image detection module 4 and the second image detection module 11, the main control module 15 can be further arranged to receive the visual detection signal and compare it with the set value, thereby selectively controlling the action of the first driving module 16 and the second driving module 17 to complete the position adjustment of the projection module LG1 and the imaging module LG2 relative to the reflective flat crystal 7, thereby realizing automatic calibration of the optical axis.

[0049] Example 3: Reference Figures 3-5 , is an AR optical waveguide detection equipment calibration device disclosed in the utility model. The difference from Example 1 is that it also includes a first exit pupil diaphragm 13 arranged between the reflective flat crystal 7 and the first lens group 5, and a second exit pupil diaphragm 14 arranged between the reflective flat crystal 7 and the second lens group 8.

[0050] Based on this, in order to calibrate the initial position relationship between the projection optical path, the imaging optical path and the waveguide stage 6, the calibration of the optical axis is divided into two steps: calibration of the optical axis tilt angle of the reflection flat crystal 7 and calibration of the XYZ position of the projection optical path and the imaging optical path:

[0051] (1) Calibration of optical axis tilt angle: refer to Figure 3 When the waveguide stage 6 is tilted, the first image detection module 4 and the second image detection module 11 can capture the change of the central reflected light and infer the tilt amount. Since the positions of the projection module LG1 and the imaging module LG2 relative to the reflection flat crystal 7 are adjustable, the orientations of the waveguide stage 6, the projection module LG1 and the imaging module LG2 can be adjusted synchronously. When the reflected light and the projected light coincide, it is recorded as the initial state of the optical axis tilt.

[0052] (2) Z-axis position calibration: refer to Figure 4 , the basis for Z-axis position calibration is that the positions of the first exit pupil diaphragm 13 and the second exit pupil diaphragm 14 must coincide with the surface of the reflective flat crystal 7. When the two do not coincide, part of the reflected light is blocked by the first exit pupil diaphragm 13 or the second exit pupil diaphragm 14 and cannot enter the first image detection module 4 or the second image detection module 11. At this time, it is necessary to adjust the Z-axis positions of the projection module LG1 and the imaging module LG2 to move them closer to or away from the surface of the reflective flat crystal 7 so that the first exit pupil diaphragm 13 and the second exit pupil diaphragm 14 coincide with the reflective flat crystal 7. Under the above position relationship, the first image detection module 4 and the second image detection module 11 will detect the reflected light with the strongest brightness, and record the Z-axis positions of the projection light path and the imaging light path at this time as the initial state;

[0053] (3) XY axis position calibration: refer to Figure 5 , move the projection module LG1 and the imaging module LG2 as a whole to the vicinity of the boundary of the reflective flat crystal 7 in the X direction or the Y direction. At this time, the central brightness of the reflected image detected by the first image detection module 4 and the second image detection module 11 will be halved, and the spatial XY two-dimensional coordinates of the projection module LG1 and the imaging module LG2 at this time are recorded as the initial state;

[0054] Reference Figure 6 After the calibration step of the optical axis, the initial relative positions of the projection optical path, the imaging optical path and the waveguide stage 6 in the five-dimensional space can be uniquely determined. In the entire calibration process, the waveguide stage 6 is used as the only reference. The calibration process only accumulates the tolerance of one optical element, the reflection flat crystal 7, which has high calibration accuracy. The switching between the calibration process and the detection process only requires switching the hardware of the reflection flat crystal 7, which has the advantages of simple structure, few tolerance transfer surfaces, high calibration accuracy and high calibration efficiency.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the technical solution of the utility model can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the utility model, which should be included in the scope of the claims of the utility model.

Claims

1. A calibration device for AR optical waveguide detection equipment, comprising a waveguide carrier (6), a reflection flat crystal (7) arranged on the waveguide carrier (6), and a projection module (LG1) and an imaging module (LG2) arranged upstream of the reflection flat crystal (7), characterized in that: The positions of the projection module (LG1) and the imaging module (LG2) relative to the reflective flat crystal (7) are adjustable respectively. The projection module (LG1) comprises a first light source module, a first spectroscopic module (3), a first lens group (5) and a first image detection module (4) which are arranged in sequence. The first lens group (5) and the first image detection module (4) are arranged on the transmission light path and the reflection light path of the first spectroscopic module (3) respectively. The imaging module (LG2) comprises a second light source module, a second spectroscopic module (10), a second lens group (8) and a second image detection module (11) which are arranged in sequence. The second lens group (8) and the second image detection module (11) are arranged on the reflection light path and the transmission light path of the second spectroscopic module (10) respectively.

2. The AR optical waveguide detection equipment calibration device according to claim 1, characterized in that: The invention also comprises a main control module (15), a first driving module (16) and a second driving module (17); a signal input end of the main control module (15) is respectively connected to the first image detection module (4) and the second image detection module (11), and a signal output end is respectively connected to the first driving module (16) and the second driving module (17); the projection module (LG1) is arranged at the mobile end of the first driving module (16), and the imaging module (LG2) is arranged at the mobile end of the first driving module (16).

3. The AR optical waveguide detection equipment calibration device according to claim 2, characterized in that: The main control module (15) is configured as a single chip microcomputer, a microprocessor, a control panel or a main control chip.

4. The AR optical waveguide detection equipment calibration device according to claim 2, characterized in that: The waveguide carrier (6) is configured as a one-dimensional slide, and the first drive module (16) and the second drive module (17) are each independently configured as a two-dimensional slide; or, the waveguide carrier (6) is configured as a two-dimensional slide, and the first drive module (16) and the second drive module (17) are each independently configured as a one-dimensional slide; the moving direction of the one-dimensional slide and the two moving directions of the two-dimensional slide are perpendicular to each other.

5. The AR optical waveguide detection equipment calibration device according to claim 2, characterized in that: At least two of the waveguide carrier (6), the first driving module (16) and the second driving module (17) are independently configured as a three-dimensional slide table.

6. The AR optical waveguide detection equipment calibration device according to claim 5, characterized in that: It also includes a first exit pupil stop (13) arranged between the reflective flat crystal (7) and the first lens group (5), and a second exit pupil stop (14) arranged between the reflective flat crystal (7) and the second lens group (8).

7. The AR optical waveguide detection equipment calibration device according to claim 1, characterized in that: The first light source module comprises a first illumination light source (1) and a first slide (2) which are arranged in sequence, and the second light source module comprises a second illumination light source (12) and a second slide (9) which are arranged in sequence.

8. The AR optical waveguide detection equipment calibration device according to claim 1, characterized in that: The first light splitting module (3) and the second light splitting module (10) are each independently configured as a light splitting prism.

9. The AR optical waveguide detection equipment calibration device according to claim 1, characterized in that: The first lens group (5) is configured as a projection lens, and the second lens group (8) is configured as an imaging lens.

10. The AR optical waveguide detection equipment calibration device according to claim 1, characterized in that: The first image detection module (4) and the second image detection module (11) are each independently configured as an image detector.

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