Inline measurement system, apparatus, and method for an optical device
The optical device measurement system addresses the challenge of controlling light intensity in augmented and virtual reality devices by using a single-stage path to measure display leakage and other criteria efficiently, improving throughput and reducing costs.
Patent Information
- Application Number
- JP2023522941
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- Priority Date
- 2020-10-15
- Filing Date
- 2021-10-04
- Publication Date
- 2025-07-16
- Estimated Expiration
- 2041-10-04
Smart Images

Figure 0007709523000003 
Figure 0007709523000004 
Figure 0007709523000005
Abstract
Description
Technical Field
[0001] Embodiments of the present disclosure relate to optical devices for augmented reality applications, virtual reality applications, and / or mixed reality applications. In one or more embodiments, an optical device measurement system is configured to measure a plurality of first measurement criteria and one or more second measurement criteria of the optical device, and the one or more second measurement criteria include display leakage measurement criteria.
Background Art
[0002] Virtual reality is generally considered to be a computer-generated and simulated environment in which a user clearly recognizes their physical presence. A virtual reality experience is generated in 3D and can be viewed with a head-mounted display (HMD) (for example, glasses or other wearable display devices having a near-eye display panel as a lens for displaying a virtual reality environment that replaces the actual environment).
[0003] However, with augmented reality, a user can experience being able to view an image of a virtual object that is generated for display and appears as part of this environment while still being able to visually recognize the surrounding environment through the display lens of glasses or other HMD device. Augmented reality may include any type of input (such as voice input and haptic input), as well as virtual images, graphics, and video that enhance or augment the environment experienced by the user. As a new technology, augmented reality has many challenges and design constraints.
[0004] One such problem is to display a virtual image superimposed on the surrounding environment. An extended waveguide coupler is used to assist in the superimposition of the image. The generated light is in-coupled (incident) into the extended waveguide coupler, propagates through the extended waveguide coupler, is out-coupled (emitted) from the extended waveguide coupler, and superimposed on the surrounding environment. The light is in-coupled and out-coupled with the extended waveguide coupler using a surface relief grating. The intensity of the out-coupled light may not be sufficiently controllable.
[0005] Accordingly, there is a need in the art for optical device measurement systems and methods. SUMMARY OF THE INVENTION
[0006] Embodiments of the present disclosure relate to optical devices for augmented reality applications, virtual reality applications, and / or mixed reality applications. In one or more embodiments, an optical device measurement system is configured to measure a plurality of first measurement criteria and one or more second measurement criteria of an optical device, and the one or more second measurement criteria include a display leakage measurement criterion.
[0007] In one embodiment, the optical device measurement system includes a stage configured to move a tray along a stage path and a first subsystem. The first subsystem includes a first body having the first opening and the second opening to allow the stage to move through the first opening and the second opening, and a first light engine positioned within the first body and mounted above the stage path. The first light engine is configured to direct a first light beam toward the stage path. The first light engine includes a first irradiator, and the first irradiator includes a first light source and a first projection structure. The first light engine includes a first lens positioned between the first irradiator and the stage path along an optical path, and one or more two-dimensional galvanometric mirrors configured to turn the first light beams along a 90 degree turn toward the stage path. The first subsystem includes a first detector positioned within the first body and mounted above the stage path to receive a first projected light beam projected upward from the stage path. The first subsystem includes a second detector positioned within the first body and mounted below the stage path to receive a second projected light beam projected downward from the stage path. The optical device measurement system includes a second subsystem, and the second subsystem includes a second body having the first opening and the second opening to allow the stage to move through the first opening and the second opening of the second body. The second subsystem includes a second light engine positioned within the second body and mounted above the stage path. The second light engine is configured to direct a second light beam toward the stage path. The second subsystem includes a face irradiation detector configured to receive a third projected light beam projected upward from the stage path. The optical device measurement system includes a controller that communicates with the stage, the first subsystem, and the second subsystem.When executed, the controller includes instructions to position the optical device within the first subsystem to align the optical device with the first detector and the second detector of the first subsystem on the stage. The instructions cause the first light engine to direct a first light beam toward the optical device, which includes rotating the first light beam 90 degrees toward the stage path. The instructions also cause the first detector to capture a plurality of first images of a first projected light beam projected from the optical device and the second detector to capture a plurality of second images of a second projected light beam projected from the optical device. The instructions also cause one or more of the plurality of first images or the plurality of second images to be processed to determine a plurality of first measurement criteria of the optical device. The instructions also cause the stage to position the optical device within the second subsystem to align the optical device with the face illumination detector of the second subsystem. The instructions also cause the second light engine to direct a second light beam toward the optical device and the face illumination detector to capture a plurality of third images of a third projected light beam projected from the optical device. The instructions also cause the plurality of third images to be processed to determine one or more second measurement criteria of the optical device, including display leakage measurement criteria.
[0008] In one embodiment, the optical device measurement system includes a stage configured to move a tray along a stage path and a first subsystem. The first subsystem includes a first body having the first aperture and the second aperture to allow the stage to move through the first aperture and the second aperture, and a first optical engine positioned within the first body and mounted above the stage path. The first optical engine is configured to direct a first light beam toward the stage path. The first optical engine includes a first irradiator, and the first irradiator includes a first light source and a first projection structure. The first optical engine includes a first lens positioned between the first irradiator and the stage path along the optical path, and one or more two-dimensional galvanometric mirrors configured to rotate the first light beam along a 90-degree rotation toward the stage path. The first subsystem includes a first detector positioned within the first body and mounted above the stage path to receive a first projected light beam projected upward from the stage path, and a second detector positioned within the first body and mounted below the stage path to receive a second projected light beam projected downward from the stage path. The optical device measurement system includes a second subsystem. The second subsystem includes a second body having the first aperture and the second aperture to allow the stage to move through the first aperture and the second aperture of the second body. The second subsystem includes a second optical engine positioned within the second body and mounted above the stage path. The second optical engine is configured to direct a second light beam toward the stage path. The second subsystem includes a face irradiation detector configured to receive a third projected light beam projected upward from the stage path.
[0009] In one embodiment, a method of analyzing an optical device includes positioning the optical device within a first subsystem to align the optical device with a first detector and a second detector of the first subsystem, and directing a first light beam from a first light engine of the first subsystem toward the optical device. Directing includes rotating the first light beam 90 degrees toward a stage path. The method includes capturing, using a first detector of the first subsystem, a plurality of first images of a first projected light beam projected from the optical device, and capturing, using a second detector of the first subsystem, a plurality of second images of a second projected light beam projected from the optical device. The method includes processing one or more of the plurality of first images or the plurality of second images to determine a plurality of first measurement criteria of the optical device, and positioning the optical device within a second subsystem to align the optical device with a face illumination detector of the second subsystem. The method includes directing a second light beam from a second light engine of the second subsystem toward the optical device, and capturing, using the face illumination detector of the second subsystem, a plurality of third images of a third projected light beam projected from the optical device. The method includes processing the plurality of third images to determine one or more second measurement criteria of the optical device. The one or more second measurement criteria include display leakage measurement criteria.
[0010] To enable a more detailed understanding of the above features of the present disclosure, a more specific description of the present disclosure, briefly summarized above, may be made by reference to embodiments, some of which are illustrated in the accompanying drawings. However, it should be noted that the accompanying drawings illustrate only exemplary embodiments and should not be regarded as limiting its scope, and other equally effective embodiments may be permitted.
Brief Description of the Drawings
[0011]
Fig. 1A
Fig. 1B
Fig. 2
Fig. 3A
Fig. 3B
Fig. 3C
Fig. 4A
Fig. 4B
Fig. 4C
Fig. 4D
Fig. 4E
Fig. 4F
Fig. 4G
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12
[0012] For ease of understanding, where possible, the same reference numbers are used to denote the same elements common to multiple figures. It is assumed that the elements and features of one embodiment can be beneficially incorporated into other embodiments without further description.
[0013] Embodiments of the present disclosure relate to optical devices for augmented reality applications, virtual reality applications, and / or mixed reality applications. In one or more embodiments, an optical device measurement system is configured to measure a plurality of first measurement criteria and one or more second measurement criteria of an optical device, and the one or more second measurement criteria include display leakage measurement criteria.
[0014] FIG. 1A is a perspective front view of a substrate 101 according to one embodiment. The substrate includes a plurality of optical devices 100 disposed on a surface 103 of the substrate 101. The optical device 100 is a waveguide combiner used in virtual reality, augmented reality, and / or mixed reality. The optical device 100 can be part of the substrate 101 so that it can be cut off from the substrate 101.
[0015] FIG. 1B is a perspective front view of the optical device 100 according to one embodiment. It should be understood that the optical device 100 described herein is an exemplary optical device, and other optical devices (such as optical devices other than waveguide combiners) may be used together or modified to achieve the aspects of the present disclosure.
[0016] Optical device 100 includes a plurality of optical device structures 102 disposed on surface 103 of substrate 101. The optical device structures 102 can be nanostructures having submicron dimensions (e.g., nano-sized dimensions). The regions of the optical device structures 102 correspond to one or more gratings 104, such as a first grating 104a, a second grating 104b, and a third grating 104c. In one embodiment that can be combined with other embodiments, optical device 100 includes at least a first grating 104a corresponding to an input coupling grating and a third grating 104c corresponding to an output coupling grating. In one embodiment that can be combined with other embodiments described herein, optical device 100 also includes a second grating 104b corresponding to an intermediate grating. The optical device structures 102 may be angled and may be binary. The optical device structures 102 are rectangular. The optical device structures 102 can have other shapes including, but not limited to, circular, triangular, elliptical, regular polygonal, irregular polygonal, and / or irregular shaped cross-sections.
[0017] During operation (such as in the case of augmented reality glasses), the input coupling grating 104a receives an incident beam (virtual image) of light having intensity from the microdisplay. The incident beam is split by the optical device structure 102 into a T1 beam having all of the intensity of the incident beam in order to direct the virtual image to the intermediate grating 104b (if utilized) or the output coupling grating 104c. In one embodiment that can be combined with other embodiments, the T1 beam undergoes total internal reflection (TIR) through the optical device 100 until the T1 beam contacts the optical device structure 102 of the intermediate grating 104b. The optical device structure 102 of the intermediate grating 104b diffracts the T1 beam into a T-1 beam, and the T-1 beam undergoes TIR through the optical device 100 to the optical device structure 102 of the output coupling grating 104c. The optical device structure 102 of the output coupling grating 104c out-couples the T-1 beam to the user's eye, modulates the field of view of the virtual image generated from the microdisplay from the user's viewpoint, and further increases the viewing angle at which the user can view the virtual image. In one embodiment that can be combined with other embodiments, the T1 beam undergoes total internal reflection (TIR) through the optical device 100 until the T1 beam contacts the optical device structure 102 of the output coupling grating and is out-coupled to modulate the field of view of the virtual image generated from the microdisplay.
[0018] To facilitate ensuring that the optical device 100 meets the image quality criteria, the measurement criteria for the measurement of the manufactured optical device 100 are obtained prior to use of the optical device 100.
[0019] Figure 2 is a schematic diagram of an optical device measurement system 200 according to one embodiment. The embodiments of the optical device measurement system 200 described herein provide the ability to increase throughput and obtain measurement criteria for multiple measurements. The measurement criteria for the measurements include an angular uniformity measurement criterion, a contrast measurement criterion, an efficiency measurement criterion, a color uniformity measurement criterion, a modulation transfer function (MTF) measurement criterion, a field of view (FOV) measurement criterion, a ghost image measurement criterion, an eye box measurement criterion, a display leakage measurement criterion, a see-through distortion measurement criterion, a see-through flare measurement criterion, a see-through ghost image measurement criterion, and a see-through transmittance measurement criterion. The throughput is increased through the use of a supply system connected to each of one or more subsystems of the optical device measurement system 200.
[0020] The optical device measurement system 200 includes a first subsystem 202, a second subsystem 204, and a third subsystem 206. Each of the first subsystem 202, the second subsystem 204, and the third subsystem 206 includes a respective main body 201A - 201C having a first opening 203 and a second opening 205. The stage 207 is movable along a stage path 211 parallel to and / or within the X - Y plane through the first opening 203 and the second opening 205 thereof. The stage 207 is operable to move in the X, Y, and Z directions in the main bodies 201A - 201C of the first subsystem 202, the second subsystem 204, and the third subsystem 206. The stage 207 includes a tray 209 operable to hold the optical device 100 (shown herein) or one or more substrates 101. The stage 207 and the tray 209 can be transparent so that the measurement reference for the measurements obtained by the first subsystem 202, the second subsystem 204, and the third subsystem 206 is not affected by the translucency of the stage 207 of the tray 209. The first subsystem 202, the second subsystem 204, and the third subsystem 206 communicate with a controller 208 operable to control the operation of the first subsystem 202, the second subsystem 204, and the third subsystem 206. The controller 208 includes instructions stored in a non - transitory computer - readable medium (such as a memory). When the instructions are executed by a processor of the controller 208, the operations described herein are performed. When the instructions are executed by a processor of the controller 208, one or more operations of one or more of the methods 1000, 1100, and / or 1200 are performed.
[0021] The instructions of the controller 208 include machine learning algorithms and / or artificial intelligence algorithms for optimizing operations. In one embodiment that can be combined with other embodiments, the instructions of the controller 208 are a regression model and include a machine learning (ML) model that averages data (such as image data collected using the measurement criteria determined herein and / or the alignment module 494). In one example that can be combined with other examples, the ML model is used to average and merge data to determine the optimized pitch and tilt of the projection structure, lens, and camera. In one example that can be combined with other examples, the ML model is used to average and merge data and apply it to the light source and laser source to determine the optimized power for generating light rays and laser beams.
[0022] The first subsystem 202 is operable to obtain one or more metrology measurement criteria including angular uniformity measurement criteria, contrast measurement criteria, efficiency measurement criteria, color uniformity measurement criteria, MTF measurement criteria, FOV measurement criteria, ghost image measurement criteria, or eye box measurement criteria. The second subsystem 204 is operable to obtain display leakage measurement criteria. The third subsystem 206 is operable to obtain one or more measurement criteria for see-through metrology including see-through distortion measurement criteria, see-through flare measurement criteria, see-through ghost image measurement criteria, or see-through transmittance measurement criteria.
[0023] The optical device measurement system 200 is configured to determine display leakage measurement criteria, one or more see-through measurement criteria, and measurement criteria for one or more other measurements for a plurality of optical devices (such as waveguide couplers) on a single system using a single stage path 211.
[0024] FIG. 3A is a schematic partial cross-sectional view of the first subsystem 202 shown in FIG. 2 according to one embodiment. The first subsystem 202 may include one or more of the configurations 400A, 400B, 400C, 400D shown in FIGS. 4A-4D.
[0025] As shown in FIG. 3A, the first subsystem 202 includes an upper portion 304 oriented toward the upper side of the optical device 100 and a lower portion 306 oriented toward the bottom side of the optical device 100.
[0026] The first subsystem 202 includes a first body 201A having a first opening 203 and a second opening 205, and the stage 207 is movable through the first opening 203 and the second opening 205. The stage 207 is configured to move the tray 209 along the stage path 211. The first subsystem 202 includes a first optical engine 310 positioned within the first body 201A and mounted above the stage path 211. The first optical engine 310 is an upper optical engine. The first optical engine 310 is configured to direct a first light beam toward the stage path 211. In one embodiment that can be combined with other embodiments, the first light beam is directed in the optical pattern design toward the stage path 211 and toward one of the optical devices 100 for determination of a metrology metric. The first subsystem 202 includes a first detector 312 positioned within the first body 201A and mounted above the stage path 211 to receive a first projected light beam projected upward from the stage path 211. The present disclosure contemplates that the projected light can be light reflected from or transmitted through the optical device. The first detector 312 is a reflection detector. The first subsystem 202 includes a second detector 316 positioned within the first body 201A and mounted below the stage path 211 to receive a second projected light beam projected downward from the stage path 211. The second detector 316 is a transmission detector. The first projected light beam and the second projected light beam are projected from the optical device 100. In one embodiment that can be combined with other embodiments, the first optical engine 310 is configured to direct the first light beam toward the input coupling grating of the optical device 100, and the first and second detectors 312, 316 are configured to receive the projected light beams projected from the output coupling grating of the optical device 100.
[0027] The upper part 304 of the first subsystem 202 includes an alignment detector 308. The alignment detector 308 includes a camera. The alignment detector 308 is operable to determine the positions of the stage 207 and the optical device 100. The lower part 306 of the first subsystem 202 includes a code reader 314 attached below the stage path 211. The code reader 314 is operable to read a code of the optical device 100, such as a quick response (QR) code or a barcode of the optical device 100. The code read by the code reader 314 may include instructions for obtaining measurement criteria for one or more measurements of various optical devices 100.
[0028] FIG. 3B is a schematic partial cross-sectional view of the second subsystem 204 shown in FIG. 2 according to one embodiment. The second subsystem 204 may include at least one configuration 400E as shown in FIG. 4E.
[0029] As shown in FIG. 3B, the second subsystem 204 includes an upper part 304 oriented toward the upper side of the optical device 100 and a lower part oriented toward the bottom side of the optical device 100.
[0030] The second subsystem 204 includes a second main body 201B and a second optical engine 360 positioned within the second main body 201B and attached above the stage path 211. The second optical engine 360 is configured to direct a second light beam toward the stage path 211. The upper part 304 of the first subsystem 202 includes an alignment detector 308.
[0031] The second subsystem 204 includes a face irradiation detector 318 configured to receive a third projected light beam projected upward from the stage path 211. The third projected light beam is projected from the optical device 100. The lower part 306 of the second subsystem 204 includes a code reader 314.
[0032] The face illumination detector 318 is operable to capture an image for obtaining a display leakage measurement criterion of the optical device 100. In one embodiment that can be combined with other embodiments, the optical pattern design is directed from the second light engine 360 towards the optical device 100, and an image of light outside the position of the user's eye is obtained and processed to obtain an eye box measurement criterion.
[0033] FIG. 3C is a schematic partial cross-sectional view of a third subsystem 206 shown in FIG. 2, according to one embodiment. The third subsystem 206 can include one or more configurations 400F and / or 400G as shown in FIGS. 4F and 4G.
[0034] As shown in FIG. 3C, the third subsystem 206 includes an upper portion 304 oriented towards the upper side of the optical device 100 and a lower portion 306 oriented towards the bottom side of the optical device 100. The third subsystem 206 includes a first light engine 370 mounted above the stage path 211 and configured to direct upper light rays towards the stage path 211, a second light engine 380 mounted below the stage path 211 and configured to direct lower light rays towards the stage path 211, and a detector 390 mounted above the stage path and configured to receive the projected light rays projected (e.g., reflected) from the output coupling grating from the upper side of the optical device 100. The upper portion 304 of the third subsystem 206 includes an alignment detector 308. The detector 390 is a reflection detector. The detector 390 detects light rays projected (e.g., reflected) from the output coupling grating from the upper side of the optical device 100. The lower portion 306 of the third subsystem 206 includes a code reader 314. Each of the first light engine 370, the second light engine 380, and the detector 390 is positioned within a third body 201C of the third subsystem 206.
[0035] FIG. 4A is a schematic diagram of a configuration 400A of the first subsystem 202 shown in FIGS. 2 and 3A, according to one embodiment. The configuration 400A includes a first light engine 310, a first detector 312, and a second detector 316.
[0036] The first light engine 310 includes a first irradiator 401, and the first irradiator 401 includes a first light source 402 and a first projection structure 404. The first light engine 310 includes a first lens 406 positioned between the first irradiator 401 and the stage path 211. The first light engine 310 includes one or more devices 413 (shown as one in FIG. 4A) positioned between the first lens 406 and the stage path 211. The one or more devices 413 include one or more of a quarter-wave plate or a linear polarizer. In one embodiment that may be combined with other embodiments described herein, the first light engine 310 is configured to emit (e.g., project) light rays in the red spectrum, green spectrum, and blue spectrum. In one example that can be combined with other examples, the first light engine 310 is configured to modulate or pulse light rays among the red spectrum, green spectrum, and blue spectrum. In one example that can be combined with other examples, the first light engine 310 includes three light sources each configured to emit light in the red spectrum, green spectrum, and blue spectrum, respectively.
[0037] The first projection structure 404 includes one or more of a display and / or a reticle. In one embodiment that may be combined with other embodiments, the first projection structure 404 includes one or more of a microdisplay, a spatial light modulator (SLM), and / or a reticle. In one example that can be combined with other examples, the SLM includes one or more of a digital micromirror device (DMD) and / or a liquid crystal on silicon (LCOS) emitter.
[0038] The first detector 312 includes a first camera 412 and a second lens 410 positioned between the first camera 412 and the stage path 211. The second detector 316 includes a second camera 416 and a third lens 414 positioned between the second camera 416 and the stage path 211. In the embodiment shown in FIG. 4A, the first projection structure 404 and the first lens 406 are oriented parallel to the stage path 211.
[0039] The optical device 100 is positioned to align the input coupler 121 of the optical device 100 with the first light engine 310 and the output coupler 122 of the optical device 100 with the first detector 312 and the second detector 316. The first light ray B1 is directed from the first light engine 310 toward the input coupler 121 of the optical device 100. The first detector 312 captures a plurality of first images of the first projection ray BP1 projected from the output coupler 122 in the red, green, and blue spectra. The second detector 316 captures a plurality of second images of the second projection ray BP2 projected from the output coupler 122 in the red, green, and blue spectra.
[0040] The first image and the second image are full-field images. One or more of the first image and / or the second image are processed (such as using the controller 208) to determine a plurality of first measurement criteria of the optical device 100.
[0041] The plurality of first measurement criteria includes an angular uniformity measurement criterion. The angular uniformity measurement criterion may represent the ratio of light intensity across a portion of the light illumination field. For angular uniformity, the processing of one or more of the plurality of first images or the plurality of second images of the image measurement criteria includes comparing one or more first portions of the light pattern design with one or more second portions of the light pattern design within a single image. For the angular uniformity measurement criterion, the first light ray B1 incident-coupled to the input coupler 121 undergoes TIR until it is out-coupled (e.g., projected (reflected, etc.)) to the first detector 312.
[0042] The plurality of first measurement criteria includes a contrast measurement criterion. The contrast measurement criterion can represent the contrast between the brightest captured light in the image and the darkest captured light in the image. For the contrast measurement criterion, the processing of one or more of the plurality of first images or the plurality of second images includes comparing one or more bright portions of the optical pattern design with one or more dark portions of the optical pattern design within a single image. For the contrast measurement criterion, the first light beam B1 that is in-coupled to the input coupler 121 undergoes TIR until the in-coupled first light beam B1 is out-coupled (e.g., projected (reflected, etc.)) to the first detector 312.
[0043] The plurality of first measurement criteria includes a color uniformity measurement criterion. The color uniformity measurement criterion can represent one or more ratios between red light, green light, and blue light in the field. One or more of the plurality of first images, the plurality of second images, and / or the plurality of third images (described later in relation to FIG. 4E) capture red, green, and blue spectra. For the color uniformity measurement criterion, the processing of one or more of the plurality of first images or the plurality of second images includes comparing the red spectrum image with the green spectrum image and the blue spectrum image using the same field area. For the color uniformity measurement criterion, the first light beam B1 that is in-coupled to the input coupler 121 undergoes TIR until the first light beam B1 is out-coupled (e.g., projected (reflected, etc.)) to the first detector 312.
[0044] The plurality of first measurement criteria includes an efficiency metric. For the efficiency metric, prior to the capture of the plurality of first images and the capture of the plurality of second images, the second detector 316 is positioned to be aligned with the input coupler 121 of the optical device 100 at a calibration position (shown by the dashed line for the second detector 316 in FIG. 4A). While the second detector 316 is at the calibration position, the first light engine 310 directs a calibration light beam towards the input coupler 121 of the optical device 100, and the second detector 316 captures one or more calibration images of the calibration projection light beam CP1 projected from the input coupler 121 of the optical device 100. The one or more calibration images are full-field images. Then, the second detector 316 is positioned to be aligned with the output coupler 122 of the optical device 100. For the efficiency metric, the first light beam B1 incoupled into the input coupler 121 undergoes TIR until it is outcoupled (e.g., projected (reflected, etc.)) to the first detector 312 and outcoupled (e.g., projected (transmitted, etc.)) to the second detector 316. The first image is a reflection image and the second image is a transmission image.
[0045] For the efficiency metric, the processing of one or more of the plurality of first images or the plurality of second images includes comparing one or more calibration images with the plurality of first images and the plurality of second images.
[0046] One or more first measurement criteria include a modulation transfer function (MTF) measurement criterion. For the MTF measurement criterion, before capturing a plurality of first images and a plurality of second images, a calibration light beam is directed from the first light engine 301 towards the second detector 316. While the position of the second detector 316 is shifted from the optical device 100, the second detector 316 captures one or more calibration images of the calibration light beam. The second detector 316 is in a calibration position shown in dashed lines in FIG. 4A and can be aligned with the first light engine 310. On the other hand, the optical device 100 can be positioned away from the second detector 316 so as to be out of the fields of view of the second detector 316 and the first light engine 310 (as shown by the dashed line for the optical device 100 in FIG. 4A). Next, the second detector 316 can be positioned to be aligned with the first detector 312. In one embodiment that can be combined with other embodiments, the second image is captured before capturing the first image. For the MTF measurement criterion, the first light beam B1 in-coupled to the input coupler 121 undergoes TIR until it is out-coupled (e.g., projected (such as reflected or transmitted)) to the first detector 312 or the second detector 316.
[0047] For the MTF measurement criterion, processing of one or more of the plurality of first images or the plurality of second images includes comparing outer edges of one or more portions of one or more calibration images with the same outer edges of the same one or more portions of one or more of the plurality of first images or the plurality of second images.
[0048] The plurality of first measurement criteria includes the eye box measurement criteria. For the eye box measurement criteria, during the capture of the plurality of first images or during the capture of the plurality of second images, the first detector 312 or the second detector 316 is moved to scan over a plurality of locations along the output coupler 122 of the optical device 100. The processing of one or more of the plurality of first images or the plurality of second images includes comparing different images corresponding to different field areas of the output coupler 122. For the eye box measurement criteria, the first light beam B1 that is in-coupled to the input coupler 121 undergoes TIR until the in-coupled first light beam B1 is out-coupled (e.g., projected (such as reflected or transmitted)) to the first detector 312 or the second detector 316.
[0049] The plurality of first measurement criteria includes the ghost image measurement criteria. For the ghost image measurement criteria, before the capture of the plurality of first images and the capture of the plurality of second images, a calibration light beam is directed from the first light engine 310 towards the second detector 316. While the position of the second detector 316 is shifted from the optical device 100, the second detector 316 captures one or more calibration images of the calibration light beam. The second detector 316 is in a calibration position shown by the dashed line in FIG. 4A and can be aligned with the first light engine 310. On the other hand, the optical device 100 can be positioned away from the second detector 316 so as to be out of the field of view of the second detector 316 and the first light engine 310 (as shown by the dashed line for the optical device 100 in FIG. 4A). Next, the second detector 316 can be positioned to be aligned with the first detector 312. In one embodiment that can be combined with other embodiments, the second image is captured before the first image is captured.
[0050] Regarding the ghost image measurement criteria, the processing of one or more images among the plurality of first images or the plurality of second images includes comparing one or more calibration images with one or more of the plurality of first images or the plurality of second images to determine the offset between them. In one embodiment that can be combined with other embodiments, the offset is the offset between the optical pattern design (such as a reticle) in one or more calibration images and the optical pattern design (such as a reticle) in the first image or the second image.
[0051] FIG. 4B is a schematic diagram of a configuration 400B of the first subsystem 202 shown in FIGS. 2 and 3A according to one embodiment. The configuration 400B includes a first optical engine 310, a first detector 312, and a second detector 316. The first optical engine 310 includes a first light source 402, a first projection structure 404, and a first lens 406. The first optical engine 310 of the configuration 400B includes one or more two-dimensional galvanometer mirrors 408 (such as an array of two-dimensional galvanometer mirrors) configured to rotate the first light beam emitted by the first projection structure 404 by 90 degrees toward the stage path 211. In the embodiment shown in FIG. 4B, the first projection structure 404 and the first lens 406 are oriented perpendicular to the stage path 211.
[0052] The first detector 312 includes a second lens 410 and a first camera 412. The second detector 316 includes a third lens 414 and a second camera 416. The first optical engine 310 uses one or more two-dimensional galvanometer mirrors 408 to rotate the first light beam B1 by 90 degrees toward the stage path 211 and toward the input coupler 121 of the optical device 100.
[0053] In the embodiment shown in FIG. 4B, the first lens 406 is positioned between the first irradiator 401 and the stage path 211 along the optical path from the first irradiator to the stage path 211. One or more two-dimensional galvanometric mirrors 408 are positioned between the first lens 406 and the stage path 211 along the optical path. The optical path includes a 90-degree rotation.
[0054] FIG. 4C is a schematic diagram of a configuration 400C of the first subsystem 202 shown in FIGS. 2 and 3A according to one embodiment. The configuration 400C is similar to the configuration 400A shown in FIG. 4A and includes one or more of its aspects, features, components, and / or characteristics.
[0055] The configuration 400C includes an alignment module 494. The alignment module 494 is shown in relation to the first light engine 310 for aligning the first projection structure 404 and the first lens 406. The alignment module 494 includes a laser source 495, a beam splitter 496, and an alignment detector 497. The alignment module 494 includes a pinhole 498 formed in a plate 499. The alignment detector 497 may include a camera. The alignment module 494 can be used in addition to the alignment detector 308.
[0056] The alignment module 494 is used to perform an alignment process. In the alignment process, the first light source 402, the first projection structure 404, and the first lens 406 are moved with a shift in position from the input coupler 121 of the optical device 100. The alignment module 494 uses a laser source 495 to direct a first laser beam L1 through a pinhole 498 towards the optical device 100. Using an alignment detector 497, the light intensity of the first reflected laser beam RL1 is determined. The first reflected laser beam RL1 is the first laser beam L1 reflected from the optical device 100. The first reflected laser beam RL1 is directed towards the alignment detector 497 using a beam splitter 496. The tilt and pitch of the laser source 495 are adjusted to increase to an increased light intensity. The first position of the first reflected laser beam RL1 received by the alignment detector 497 is determined at the increased light intensity. The first position is the position of the first reflected laser beam RL1 within the image captured by the alignment detector 497 when the alignment detector 497 captures the first reflected laser beam RL1.
[0057] In the alignment process, the first lens 406 is moved to be aligned with the input coupler 121 of the optical device 100 (as shown by the dashed line in Figure 4C), and a second laser beam is directed through the pinhole 498 towards the first lens 406. The tilt and pitch of the first lens 406 are adjusted until the second position of the second reflected laser beam received by the alignment detector matches the first position of the first reflected laser beam RL1. The second reflected laser beam is the second laser beam reflected from the first lens 406 and returning towards the beam splitter 496.
[0058] In the alignment process, the first projection structure 404 is moved to be aligned with the input coupler 121 of the optical device 100 (as shown by the dashed line in FIG. 4C), and the third laser light is directed toward the first projection structure 404 through the pinhole 498. The tilt and pitch of the first projection structure 404 are adjusted until the third position of the third reflected laser light received by the alignment detector coincides with the first position of the first reflected laser light RL1. The third reflected laser light is the third laser light that is reflected from the first projection structure 404 and returns toward the beam splitter 496.
[0059] Next, the alignment module 494 is moved out of alignment from the input coupler 121 of the optical device 100, and the first light source 402 can be moved to be aligned with the input coupler 121 of the optical device 100. The lens, the projection structure, and the camera can be aligned using the alignment module 494 and the alignment process to facilitate accurate processes such as accurate determination of the measurement reference of the optical device 100. The process described for the alignment process can be combined with the methods 1000, 1100, 1200 described below.
[0060] FIG. 4D is a schematic diagram of a configuration 400D of the first subsystem 202 shown in FIGS. 2 and 3A according to one embodiment. The configuration 400D includes a first light engine 310, a first detector 312, and a second detector 316. The first light engine 310 includes a first lens 406a positioned between the first light source 402, the first projection structure 404, and the first illuminator 401, and a lens 406b positioned between the first lens 406a and the stage path 211. The first light engine 310 includes an adjustable aperture 407 positioned between the lens 406b and the first lens 406a. The adjustable aperture 407 can be formed in the plate 415. The adjustable aperture 407 can be adjusted by moving the adjustable aperture 407 up and down (such as moving the plate 415) and / or opening and closing the adjustable aperture 407.
[0061] The first light engine 310 may include one or more devices 413 shown in FIG. 4A positioned between the lens 406b and the stage path 211. The first detector 312 includes a second lens 410 and a first camera 412. The second detector 316 includes a third lens 414 and a second camera 416. In one embodiment that can be combined with other embodiments, each of the first lens 406, the first lens 406a, the lens 406b, the second lens 410, and / or the third lens 414 is formed of the same convex lens structure having the same radius of curvature. Each of the first lens 406, the first lens 406a, the lens 406b, the second lens 410, and / or the third lens 414 has the same lens structure. By using the same lens structure for the lenses, it becomes easy to compensate for optical aberrations such as reflection and / or transmission aberrations of light.
[0062] FIG. 4E is a schematic diagram showing a configuration 400E of the second subsystem 204 shown in FIGS. 2 and 3B according to one embodiment. The configuration 400E includes a second light engine 360 and a face illumination detector 318. The second light engine 360 includes a second irradiator 461 and a fourth lens 466 positioned between the second irradiator 461 and the stage path 211. The second irradiator 461 includes a second light source 462 and a second projection structure 464. The second projection structure 464 and the fourth lens 466 are oriented parallel to the stage path 211.
[0063] The second projection structure 464 includes one or more of a display and / or a reticle. In one embodiment that can be combined with other embodiments, the second projection structure 464 includes one or more of a microdisplay, a spatial light modulator (SLM), and / or a reticle. In one example that can be combined with other examples, the SLM includes one or more of a digital micromirror device (DMD) and / or a liquid crystal on silicon (LCOS) emitter.
[0064] The face illumination detector 318 includes a third camera 426, a fifth lens 424 positioned between the third camera 426 and the stage path 211, and an eye box blocker 420 positioned between the fifth lens 424 and the stage path 211. The eye box blocker 420 is adjacent to the face level 422.
[0065] The optical device 100 is positioned to align the input coupler 121 with the second light engine 360 and the output coupler 122 with the face illumination detector 318. The second light beam B2 is directed from the second light engine 360 toward the input coupler 121 of the optical device 100. The face illumination detector 318 captures a plurality of third images of the third projection light beam BP3 (in addition to the first and second images described in connection with FIG. 4A) projected from the output coupler 122 of the optical device 100.
[0066] The plurality of third images includes the third projection light beam BP3 projected from the output coupler 122 of the optical device 100 and passing through the eye box blocker 420 of the face illumination detector 318. The plurality of third images is processed (such as by using the controller 208) to determine one or more second measurement criteria of the optical device. The one or more second measurement criteria includes a display leakage measurement criterion.
[0067] FIG. 4F is a schematic diagram of a configuration 400F of a third subsystem 206 shown in FIGS. 2 and 3C according to one embodiment. The third subsystem 206 includes a first light engine 310 mounted above the stage path 211 and configured to direct an upper light beam toward the stage path 211, and a second light engine 322 mounted below the stage path 211 and configured to direct a lower light beam toward the stage path 211.
[0068] Configuration 400F includes a detector 320 that is mounted above the stage path 211 and configured to receive the projection light beam projected from the stage path 211. The projected light beam is projected from the optical device 100. The first light engine 310 includes a first irradiator 401 and a first lens 406. The detector 320 includes a second lens 410 and a first camera 412. The second light engine 322 includes a device and a third lens.
[0069] The second light engine 322 includes a second irradiator 471 and a second lens 476 positioned between the second irradiator 471 and the stage path 211. The second irradiator 471 includes a second light source 472 and a second projection structure 474. The second projection structure 474 is a display or a reticle. In one embodiment that can be combined with other embodiments, using the configuration 400F, the output coupling grating of the optical device 100 is irradiated with the lower light beam emitted by the second light engine 322, whereby the see-through transmittance measurement criterion of the optical device 100 is obtained.
[0070] As shown in FIG. 4F, the input coupler 121 of the optical device 100 is aligned with the first light engine 310, and the output coupler 122 is aligned with the second light engine 322. The detector 320 is aligned with the second light engine 322 (e.g., in the vertical direction) and is misaligned from the first light engine 310. The second light engine 322 directs the first light beam LB1 toward the output coupler 122. The upper light beam LB2 can be directed from the first light engine 310 toward the input coupler 121 of the optical device 100. Using the detector 320, a plurality of first images of the first light beam LB1 that is transmitted through the output coupler 122 and projected from the output coupler 122 as the first projection light beam PB1 are captured. The optical device 100 is positioned away from the second light engine 322 to shift the position of the optical device 100 from the second light engine 322 (shown by the dashed line in FIG. 4F for the optical device 100) and to position the optical device 100 outside the fields of view of the second light engine 322 and the detector 320. The second light beam is directed from the second light engine 322 toward the detector 320. The detector captures a plurality of second images of the second light beam projected from the waveguide coupler as the second projection light beam. The first image and the second image are full-field images. The first light beam and the second light beam are emitted from the light engine in the red spectrum, green spectrum, and blue spectrum (e.g., sequentially). The plurality of first images and the plurality of second images each capture the first light beam and the second light beam in the red spectrum, green spectrum, and blue spectrum. In one embodiment that can be combined with other embodiments, the second image is captured before the first image.
[0071] The second image is compared with the first image (e.g., by using the controller 208) to determine the see-through transmittance measurement criterion of the optical device 100. In one embodiment that can be combined with other embodiments, comparing includes comparing the second light intensity of the plurality of second images with the first light intensity of the plurality of first images.
[0072] Figure 4G is a schematic diagram of a 400G configuration 400 of the third subsystem 206 shown in FIGS. 2 and 3C according to one embodiment. Configuration 400G includes a detector 320 and a first optical engine 310. Configuration 400G includes a patterned substrate 490 positioned below the stage path 211. The patterned substrate 490 includes a pattern design formed thereon. Each of the first optical engine 310, the patterned substrate 490, and the detector 320 is positioned within the third body 201C of the third subsystem 206. In one embodiment that can be combined with other embodiments, the patterned substrate 490 includes one or more of a plurality of protrusions 493 and / or a plurality of recesses 489 (shown by dashed lines in FIG. 4G) that form the pattern design.
[0073] In the aligned position shown in FIG. 4G, the patterned substrate 490 is at least partially aligned below the detector 320, and the patterned substrate 490 is at least partially misaligned from the first optical engine 310. The optical device 100 below the detector 320 aligns the optical device 100 with the detector 320, and the optical device 100 is positioned above the patterned substrate 490 at a distance D1 from the patterned substrate 490.
[0074] The patterned substrate 490 directs the lower light beam 491 towards the optical device 100. The lower light beam 491 is reflected from the upper surface of the patterned substrate 490 towards the optical device 100. The lower light beam 491 passes through the optical device 100 and is captured using the detector 320. In one embodiment that can be combined with other embodiments, the patterned substrate 490 reflects ambient light as the lower light beam 491. In one embodiment that can be combined with other embodiments, the patterned substrate 490 reflects light from a light engine such as the second light engine 322. In one embodiment that can be combined with other embodiments, the configuration 400G includes a second light engine 322 configured to direct a light beam towards the patterned substrate 490, and the patterned substrate 490 reflects the light beam from the second light engine 322 as the lower light beam 491. The first light engine 310 includes a first light source 402, a first projection structure 404, and a first lens 406. The detector 320 includes a second lens 410 and a first camera 412.
[0075] While the patterned substrate 490 is partially aligned with the detector 320 and is partially misaligned from the detector 320 (shown in FIG. 4G), the detector 320 captures a plurality of first images of the projection light beam 492 projected from the output coupler 122 of the optical device 100. The plurality of first images capture the red spectrum, green spectrum, and blue spectrum of the projection light beam 492. The plurality of first images are processed (e.g., by the controller 208) to determine one or more see-through measurement criteria of the optical device 100.
[0076] One or more through-sheet measurement criteria include through-sheet flare measurement criteria. For through-sheet flare measurement criteria, the optical device 100 is positioned below the first light engine 310 to align the input coupler 121 of the optical device 100 with the first light engine 310. The first light beam LB3 is directed from the first light engine 310 toward the input coupler 121 of the optical device 100. In such an embodiment, the projected light beam 492 includes the first light beam LB3 from the first light engine 310 and the lower light beam 491 reflected from the patterned substrate 490. The first light beam LB3 is emitted from the first light engine 310 with a light pattern design different from the pattern design of the patterned substrate 490.
[0077] One or more through-sheet measurement criteria include one or more of through-sheet distortion measurement criteria and / or through-sheet transmittance measurement criteria. For through-sheet distortion measurement criteria and / or through-sheet transmittance measurement criteria, the projected light beam 492 includes the light beam 491 reflected from the patterned substrate 490. The optical device 100 is positioned away from the detector 320 to shift the position of the optical device 100 from the detector 320 and the patterned substrate 490 (shown by the dashed line for the optical device 100 in FIG. 4G) and to position the optical device 100 out of the field of view of the patterned substrate 490 and the detector 320. The detector 320 captures a plurality of second images of the reflected light beam reflected from the patterned substrate 490 toward the detector 320. The plurality of second images capture the reflected light beams in the red spectrum, green spectrum, and blue spectrum. Processing of the plurality of first images includes comparing the plurality of second images with the plurality of first images to determine the through-sheet distortion measurement criteria and / or through-sheet transmittance measurement criteria. In one embodiment that can be combined with other embodiments, the second image is captured before the first image is captured.
[0078] One or more through-sheet measurement criteria include through-sheet ghost image measurement criteria. For the through-sheet ghost image measurement criteria, the optical device 100 is positioned away from the detector 320 in order to shift the position of the optical device 100 from the detector 320 and the patterned substrate 490. The detector 320 captures a plurality of second images of the reflected light rays reflected from the patterned substrate 490 using the detector 320. The plurality of second images capture the reflected light rays in the red spectrum, green spectrum, and blue spectrum. Processing the plurality of first images includes determining an offset between the plurality of second images and the plurality of first images. In one embodiment that can be combined with other embodiments, the offset is the offset between the pattern design (such as a reticle) in the first image and the pattern design (such as a reticle) in the second image.
[0079] FIG. 5 is a schematic diagram of an image 500 according to one embodiment. The image 500 includes a light pattern design (such as a reticle) having a dark portion 501 and a bright portion 502. The image 500 can be used to determine contrast measurement criteria and / or angular uniformity measurement criteria.
[0080] For the angular uniformity measurement criteria, the processing includes comparing one or more first portions 502a of the light pattern design with one or more second portions 502b, 502c of the light pattern design within the image 500. The first and second portions 502a, 502b, 502c correspond to the bright portion 502. The processing includes comparing the light intensity of one or more first portions 502a with the light intensity of one or more second portions 502b, 502c. The portions 502a, 502b, 502c are arranged at different radii with respect to the center of the image 500.
[0081] Regarding the contrast measurement criteria, the process includes comparing the light intensity of one or more bright portions 502a of the optical pattern design within the image 500 with the light intensity of one or more dark portions 501a of the optical pattern design within the image 500. The bright portion 502a has a light intensity I1, and the dark portion 501a has a light intensity I2. The contrast measurement criteria can be determined and represented as "C" by Equation 1 below. TIFF0007709523000001.tif13170
[0082] Figures 6A - 6C are schematic diagrams of images 610, 620, 630 according to one embodiment. Figure 6A shows a red image 610, Figure 6B shows a green image 620, and Figure 6C shows a blue image 630. The images 610, 620, 630 are used to determine the color uniformity measurement criteria. The process includes comparing the images 610, 620, 630 using the same field area in each respective image 610, 620, 630. The same field area includes one or more bright portions 602a - 602c, 603a - 603c at the same position in each of the images 610, 620, 630. The color uniformity measurement criteria can represent the ratio of the light intensities of one or more bright portions 602a - 602c, 603a - 603c in each of the images 610, 620, 630.
[0083] Figures 7A - 7C are schematic diagrams of images 710, 720, 730 according to one embodiment. Figure 7A shows a calibration image 710, Figure 7B shows a first image (e.g., a reflection image), and Figure 7C shows a second image (e.g., a transmission image). The images 710, 720, 730 can be used to determine the efficiency measurement criteria.
[0084] The process includes comparing the calibration image 710 with the first image 720 and the second image 730 using the same field area in each of the respective images 710, 720, 730. The same field area includes one or more bright portions 702a-702c at the same position in each of the images 710, 720, 730. The process includes comparing the light intensities of one or more bright portions 702a-702c in the images 710, 720, 730. The calibration image 710 includes the light intensity IC1 of the bright portion 702a, the first image 720 includes the light intensity IR1 of the bright portion 702b, and the second image 730 includes the light intensity IT1 of the bright portion 702c.
[0085] The efficiency measurement criterion can be determined and represented as "E" by Equation 2 below. TIFF0007709523000002.tif14170
[0086] FIG. 8 is a schematic diagram of an image 800 according to one embodiment. The image 800 includes an optical pattern design (such as a reticle) having dark and bright portions. The image 800 can be used to determine the MTF measurement criterion. The process includes comparing an edge area 832 of one or more calibration images with the same edge area (e.g., the same position within the image) of the same one or more portions of one or more of the plurality of first images or the plurality of second images. The edge region 832 at least partially encompasses the outer edge 831 of one or more portions (such as bright portions).
[0087] FIGS. 9A-9C are schematic diagrams of images 910, 920, 930 according to one embodiment. Each of the images 910, 920, 930 shows an optical pattern design that can be used for light directed by the first light engine 310, the first light engine 370, the second light engine 360, the first light engine 370, the second light engine 380, the second light engine 322, and / or the patterned substrate 490. Each of the images 910, 920, 930 can be used to determine the ghost image measurement criterion and / or other measurement criteria (such as other first measurement criteria). Each of the images 910, 920, 930 includes a plurality of dark portions 901a-901c and a plurality of bright portions 902a-902c.
[0088] Figure 10 is a schematic block diagram of a method 1000 for analyzing an optical device according to one embodiment.
[0089] Step 1002 of method 1000 includes positioning the optical device within the first subsystem to align the optical device with a first detector and a second detector of the first subsystem.
[0090] Step 1004 includes directing a first light beam from a first light engine of the first subsystem toward the optical device. In one embodiment that can be combined with other embodiments, directing includes rotating the first light beam 90 degrees toward the stage path.
[0091] Step 1006 includes capturing a plurality of first images of a first projection light beam projected from the optical device using a first detector of the first subsystem.
[0092] Step 1008 includes capturing a plurality of second images of a second projection light beam projected from the optical device using a second detector of the first subsystem.
[0093] Step 1010 includes processing one or more of the plurality of first images or the plurality of second images to determine a plurality of first measurement criteria for the optical device. The first measurement criteria includes an angular uniformity measurement criterion, a contrast measurement criterion, an efficiency measurement criterion, a color uniformity measurement criterion, a modulation transfer function (MTF) measurement criterion, a field of view (FOV) measurement criterion, a ghost image measurement criterion, and / or an eyebox measurement criterion.
[0094] Step 1012 includes positioning the optical device within the second subsystem to align the optical device with a face illumination detector of the second subsystem.
[0095] Operation 1014 includes directing a second light beam from a second light engine of a second subsystem toward an optical device.
[0096] Operation 1016 includes capturing, using a face illumination detector of a second subsystem, a plurality of third images of a third projected light beam projected from the optical device.
[0097] Operation 1018 includes processing the plurality of third images to determine one or more second measurement criteria of the optical device. The one or more second measurement criteria include display leakage measurement criteria.
[0098] FIG. 11 is a schematic block diagram of a method 1100 for analyzing an optical device according to one embodiment.
[0099] Operation 1102 of method 1100 includes positioning an optical device above a light engine to align the optical device with the light engine.
[0100] Operation 1104 includes directing a first light beam from the light engine toward the optical device.
[0101] Operation 1106 includes capturing, using a detector, a plurality of first images of the first light beam projected from the optical device as a first projected light beam.
[0102] Operation 1108 includes positioning the optical device away from the light engine to shift the position of the optical device from the light engine.
[0103] Operation 1110 includes directing a second light beam from the light engine toward the detector.
[0104] Operation 1112 includes capturing a plurality of second images of the second light beam.
[0105] Operation 1114 includes comparing a plurality of second images with a plurality of first images to determine a see-through transmittance measurement criterion for an optical device.
[0106] FIG. 12 is a schematic block diagram of a method 1200 for analyzing an optical device according to one embodiment.
[0107] Operation 1202 of method 1200 includes positioning an optical device below a detector to align the optical device with the detector.
[0108] Operation 1204 includes positioning the optical device above a patterned substrate at a distance from the patterned substrate. The patterned substrate includes a pattern design formed thereon.
[0109] Operation 1206 includes capturing, using the detector, a plurality of first images of projection light rays projected from the optical device while the patterned substrate is at least partially aligned with the detector.
[0110] Operation 1208 includes processing the plurality of first images to determine one or more see-through measurement criteria for the optical device. The one or more see-through measurement criteria include one or more of a see-through transmittance measurement criterion, a see-through distortion measurement criterion, a see-through flare measurement criterion, and / or a see-through ghost image.
[0111] The advantages of the present disclosure include using a single-stage path 211 to determine measurement criteria (such as display leakage measurement criteria, one or more see-through measurement criteria, and measurement criteria for one or more other measurements) for several measurements of multiple optical devices (such as waveguide couplers) on a single system, using a single optical device measurement system 200. In one embodiment that can be combined with other embodiments, a single system using a single-stage path 211 can be used to determine display leakage measurement criteria, angular uniformity measurement criteria, contrast measurement criteria, efficiency measurement criteria, color uniformity measurement criteria, modulation transfer function (MTF) measurement criteria, field of view (FOV) measurement criteria, ghost image measurement criteria, eye box measurement criteria, see-through distortion measurement criteria, see-through flare measurement criteria, see-through ghost image measurement criteria, and see-through transmittance measurement criteria. Also included are advantages such as an increase in throughput, reduction in delay and cost, and improvement in efficiency. The throughput increases through the utilization of a supply system connected to each subsystem of the optical device measurement system.
[0112] It is contemplated that one or more aspects disclosed herein may be combined. By way of example, one or more aspects, features, components, and / or characteristics of the optical device measurement system 200, the first subsystem 202, the second subsystem 204, the third subsystem 206, configuration 400A, configuration 400B, configuration 400C, configuration 400D, configuration 400E, configuration 400F, configuration 400G, image 500, images 610 - 630, images 710 - 730, image 800, images 910 - 930, method 1000, method 1100, and / or method 1200 may be combined. By way of example, one or more of the steps described in relation to the optical device measurement system 200, subsystems 202, 204, 206, and / or configurations 400A - 400G may be combined with one or more of the steps described in relation to method 1000, method 1100, and / or method 1200. Further, it is contemplated that one or more aspects disclosed herein may include some or all of the aforementioned advantages.
[0113] The above description is directed to embodiments of the present disclosure, but other and further embodiments of the present disclosure may be devised without departing from the basic scope thereof, and the scope of the present disclosure is determined by the following claims.
Claims
Claim 1 A measurement system for determining a plurality of measurement criteria for a waveguide coupler, comprising: a stage configured to move a tray along a stage path; a first subsystem, comprising: a first body having a first opening and a second opening to allow the stage to move through the first opening and the second opening; a first optical engine positioned within the first body and mounted above the stage path, the first optical engine being configured to direct a first light beam toward the stage path; a first irradiator comprising a first light source and a first projection structure; a first lens positioned along an optical path between the first irradiator and the stage path; and one or more two-dimensional galvanometer mirrors configured to rotate the first light beam 90 degrees toward the stage path; a first optical engine; a first detector positioned within the first body and mounted above the stage path to receive a first projected light beam projected upward from the stage path; and a second detector positioned within the first body and mounted below the stage path to receive a second projected light beam projected downward from the stage path; a first subsystem; a second subsystem, comprising: a second body having a first opening and a second opening to allow the stage to move through the first opening and the second opening of the second body; a second optical engine positioned within the second body and mounted above the stage path, the second optical engine being configured to direct a second light beam toward the stage path; a third detector configured to receive a third projected light beam projected upward from the stage path, comprising: a third camera; a fifth lens positioned between the third camera and the stage path; and an eyebox blocker positioned between the fifth lens and the stage path, the eyebox blocker blocking a central portion, but not the entire third projected light beam, from reaching the third camera; a third detector; a second subsystem; A controller that communicates with the stage, the first subsystem, and the second subsystem, and when executed, Positioning the waveguide coupler within the first subsystem to align the output coupler of the waveguide coupler with the first detector and the second detector of the first subsystem for the stage; Directing a first light ray toward the input coupler of the waveguide coupler in the first optical engine, including rotating the first light ray 90 degrees toward the stage path; Causing the first detector to capture a plurality of first images of a first projected light ray projected from the output coupler of the waveguide coupler; Causing the second detector to capture a plurality of second images of a second projected light ray projected from the output coupler of the waveguide coupler; Processing one or more of the plurality of first images or the plurality of second images to determine a plurality of first measurement criteria for the waveguide coupler; Positioning the waveguide coupler within the second subsystem to align the output coupler of the waveguide coupler with the third detector of the second subsystem for the stage; Directing a second light ray toward the input coupler of the waveguide coupler in the second optical engine; Causing the third detector to capture a plurality of third images of a third projected light ray projected from the output coupler of the waveguide coupler; Processing the plurality of third images to determine one or more second measurement criteria for the waveguide coupler, including display leakage measurement criteria for a portion of the third projected light ray that leaks outside the eyebox blocker; A controller including instructions to perform the above; A measurement system comprising the above. **Claim 2** The measurement system according to claim 1, wherein one or more of the plurality of first images, the plurality of second images, or the plurality of third images capture a red spectrum, a green spectrum, and a blue spectrum. **Claim 3** A measurement system for determining a plurality of measurement criteria for a waveguide coupler having input and output couplers spaced apart from each other, comprising A stage configured to move a tray along a stage path; A first subsystem, A first body having the first opening and the second opening for enabling the stage to move through the first opening and the second opening; A first light engine positioned within the first body and mounted above the stage path, the first light engine being configured to direct a first light beam to a first location of the stage path; A first irradiator comprising a first light source and a first projection structure; A first lens positioned between the first irradiator and the stage path along the optical path; One or more two-dimensional galvanometer mirrors configured to rotate the first light beam 90 degrees toward the first location of the stage path; The first light engine comprising; A first detector positioned within the first body and mounted above the stage path for receiving a first projection light beam projected upward from a second location of the stage path; A second detector positioned within the first body and mounted below the stage path for receiving a second projection light beam projected downward from the second location of the stage path; The first subsystem comprising, wherein the second location is a location aligned with the output coupler when the first location is aligned with the input coupler; A second subsystem, A second body having the first opening and the second opening for enabling the stage to move through the first opening and the second opening of the second body; A second light engine positioned within the second body and mounted above the stage path, the second light engine being configured to direct a second light beam to a third location of the stage path; A third detector configured to receive a third projection light beam projected upward from a fourth location of the stage path; The second subsystem comprising; The measurement system comprising, wherein the fourth location is a location aligned with the output coupler when the third location is aligned with the input coupler. Claim 4 The first projection structure and the first lens of the first subsystem are oriented perpendicular to the stage path, and the first optical engine further includes an alignment module including a laser source, a beam splitter, a pinhole, and an alignment detector. The measurement system according to claim 3.
5. The first detector includes a first camera and a second lens positioned between the first camera and the stage path. The second detector includes a second camera and a third lens positioned between the second camera and the stage path. The measurement system according to claim 4.
6. The second optical engine of the second subsystem includes a second irradiator and a fourth lens positioned between the second irradiator and the stage path. The second irradiator includes a second light source and a second projection structure. The measurement system according to claim 5.
7. The second projection structure and the fourth lens are oriented parallel to the stage path. The measurement system according to claim 6.
8. The third detector of the second subsystem is a third camera and a fifth lens positioned between the third camera and the stage path, and an eyebox blocker positioned between the fifth lens and the stage path, the eyebox blocker blocking a central portion that is not the entire third projection ray from reaching the third camera The measurement system according to claim 7.
9. The measurement system further includes a controller that communicates with the first subsystem and the second subsystem. When executed, the controller determines one or more first measurement criteria of the waveguide coupler using the first subsystem, including one or more of an angular uniformity measurement criterion, a contrast measurement criterion, an efficiency measurement criterion, a color uniformity measurement criterion, a modulation transfer function (MTF) measurement criterion, a field of view (FOV) measurement criterion, a ghost image measurement criterion, or an eyebox measurement criterion. one or more second measurement criteria of the waveguide coupler using the second subsystem, including a display leakage measurement criterion regarding a portion of the third projection ray that leaks outside the eyebox blocker. The measurement system according to claim 8, including instructions to determine.
10. A method for analyzing a waveguide coupler, comprising: Positioning the waveguide coupler within the first subsystem to align an output coupler of the waveguide coupler with a first detector and a second detector of a first subsystem; Directing a first light beam from a first light engine of the first subsystem toward an input coupler of the waveguide coupler, including rotating the first light beam 90 degrees toward a stage path; Capturing, using the first detector of the first subsystem, a plurality of first images of a first projected light beam projected from the output coupler of the waveguide coupler; Capturing, using the second detector of the first subsystem, a plurality of second images of a second projected light beam projected from the output coupler of the waveguide coupler; Processing one or more of the plurality of first images or the plurality of second images to determine a plurality of first measurement criteria for the waveguide coupler; Positioning the waveguide coupler within the second subsystem to align the output coupler of the waveguide coupler with a third detector including an eyebox blocker of a second subsystem; Directing a second light beam from a second light engine of the second subsystem toward the input coupler of the waveguide coupler; Capturing, using the third detector of the second subsystem, a plurality of third images of a third projected light beam projected from the output coupler of the waveguide coupler; Processing the plurality of third images to determine one or more second measurement criteria for the waveguide coupler, including a display leakage measurement criterion for a portion of the third projected light beam that leaks outside the eyebox blocker; Including The method, wherein the eyebox blocker blocks a central portion that is not the entire third projected light beam from being detected by the third detector. **Claim 11** Further comprising performing an alignment process for the first light engine, the alignment process comprising: Directing a first laser beam through a pinhole toward the waveguide coupler using a laser source; Determining the light intensity of a first reflected laser beam using an alignment detector; Adjusting the tilt and pitch of the laser source to increase the light intensity to an increased light intensity. Determining a first position of the first reflected laser light received by the alignment detector at the increased light intensity; Directing a second laser light through the pinhole towards a first lens of the first light engine; Adjusting a tilt and a pitch of the first lens until a second position of a second reflected laser light received by the alignment detector matches the first position; Directing a third laser light through the pinhole towards a first projection structure of the first light engine; Adjusting a tilt and a pitch of the first projection structure until a third position of a third reflected laser light received by the alignment detector matches the first position The method according to claim 10, comprising. **Claim 12** The method according to claim 10, wherein the plurality of first images are captured while the first detector is aligned with the output coupler of the waveguide coupler, and the plurality of second images are captured while the second detector is aligned with the output coupler of the waveguide coupler. **Claim 13** The plurality of first measurement criteria includes an angular uniformity measurement criterion, and processing one or more of the plurality of first images or the plurality of second images comprises: Comparing one or more first portions of a light pattern design with one or more second portions of the light pattern design within a single image The method according to claim 10, comprising. **Claim 14** The plurality of first measurement criteria includes a contrast measurement criterion, and processing one or more of the plurality of first images or the plurality of second images comprises: Comparing one or more bright portions of a light pattern design with one or more dark portions of the light pattern design within a single image The method according to claim 10, comprising. **Claim 15** The plurality of first measurement criteria includes a color uniformity measurement criterion, One or more of the plurality of first images, the plurality of second images, or the plurality of third images capture a red spectrum, a green spectrum, and a blue spectrum, Processing one or more of the plurality of first images or the plurality of second images comprises: Comparing a red spectrum image with a green spectrum image and a blue spectrum image using the same field area The method according to claim 10, comprising. **Claim 16** The plurality of first measurement criteria includes efficiency measurement criteria, and before capturing the plurality of first images and capturing the plurality of second images, the method positions the second detector to align with the input coupler of the waveguide coupler; directs a calibration light beam from the first light engine of the first subsystem towards the waveguide coupler; captures one or more calibration images of the calibration projection light beam projected from the input coupler of the waveguide coupler using the second detector; positions the second detector to align with the output coupler of the waveguide coupler The method according to claim 10, further comprising. **Claim 17** The one or more first measurement criteria includes modulation transfer function (MTF) measurement criteria, and before capturing the plurality of first images and capturing the plurality of second images, the method directs a calibration light beam from the first light engine of the first subsystem towards the second detector; captures one or more calibration images of the calibration light beam using the second detector while the position of the second detector is shifted from the waveguide coupler further comprising Processing one or more of the plurality of first images or the plurality of second images includes comparing outer edges of one or more portions of the one or more calibration images with the same outer edges of the same one or more portions of one or more of the plurality of first images or the plurality of second images. The method according to claim 10. **Claim 18** The plurality of first measurement criteria includes eye box measurement criteria, The first detector or the second detector is moved to scan over a plurality of locations along the output coupler of the waveguide coupler during capturing of the plurality of first images or during capturing of the plurality of second images, Processing one or more of the plurality of first images or the plurality of second images includes comparing different images corresponding to different field areas of the output coupler. The method according to claim 10. **Claim 19** The plurality of first measurement criteria includes ghost image measurement criteria, and before capturing the plurality of first images and capturing the plurality of second images, the method directs a calibration light beam from the first light engine of the first subsystem towards the second detector; While the position of the second detector is shifted from the waveguide coupler, capturing one or more calibration images of the calibration light beam using the second detector further comprising processing one or more of the plurality of first images or the plurality of second images comprises comparing the one or more calibration images with one or more of the plurality of first images or the plurality of second images to determine an offset therebetween, the method of claim 10 Claim 20 The method according to any one of claims 10 to 19, wherein the waveguide coupler is a waveguide coupler used in virtual reality, augmented reality, and / or mixed reality
Citation Information
Patent Citations
Visual inspection method and device of semiconductor wafer
JP1997252035A
Tester and inspection device
JP2005164488A
Methods and apparatus for waveguide metrology
US20200141802A1
Optical inspection device
WO2018088423A1
Optical device testing method and apparatus
WO2020148574A1