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CN-121978838-A - AR display module, AR display device and control method

CN121978838ACN 121978838 ACN121978838 ACN 121978838ACN-121978838-A

Abstract

The application relates to an AR display module, an AR display device and a control method, which belong to the technical field of AR display and comprise an optical machine module and a waveguide lens module, wherein the waveguide lens module comprises a first waveguide layer and a second waveguide layer, the first waveguide layer comprises a first polarized volume grating, the first polarized volume grating is configured to diffract first rotary circular polarized light, the second waveguide layer comprises a second polarized volume grating, the second polarized volume grating is configured to diffract second rotary circular polarized light, projections of the first polarized volume grating and the second polarized volume grating on the waveguide lens module are overlapped with each other to form a transition zone, and in the transition zone, the refractive index modulation depth of the first polarized volume grating gradually decreases along the direction towards the second waveguide layer, and the refractive index modulation depth of the second polarized volume grating gradually decreases along the direction towards the first waveguide layer so as to complement polarized image beams emitted by the first waveguide layer and the second waveguide layer.

Inventors

  • WANG YUYANG
  • CUI HAITAO

Assignees

  • 广东谷东智能科技有限公司

Dates

Publication Date
20260505
Application Date
20260318

Claims (10)

  1. 1. An AR display module, comprising: The optical machine module (1) comprises an Lcos display chip (11) and a polarization switching component (12), wherein the Lcos display chip (11) is used for outputting polarized image light beams, and the polarization switching component (12) is used for alternately switching the polarization states of the polarized image light beams so as to enable the polarized image light beams to form first rotary circular polarized light or second rotary circular polarized light after being transmitted; A waveguide lens module (2) comprising a first waveguide layer (21) and a second waveguide layer (22), the first waveguide layer (21) comprising a first polarization volume grating (211), the first polarization volume grating (211) being configured to diffract the first circularly polarized light, the second waveguide layer (22) comprising a second polarization volume grating (221), the second polarization volume grating (221) being configured to diffract the second circularly polarized light; Projections of the first polarizing volume grating (211) and the second polarizing volume grating (221) on the waveguide lens module (2) are overlapped with each other to form a transition region (3), and in the transition region (3), the refractive index modulation depth of the first polarizing volume grating (211) gradually decreases along the direction towards the second waveguide layer (22), and the refractive index modulation depth of the second polarizing volume grating (221) gradually decreases along the direction towards the first waveguide layer (21) so as to complement polarized image light beams emitted by the first waveguide layer (21) and the second waveguide layer (22).
  2. 2. The AR display module set according to claim 1, wherein the refractive index modulation depth of the first polarization volume grating (211) is defined as K1, the refractive index modulation depth of the second polarization volume grating (221) is defined as K2, and a predetermined constant K is set at any position in the transition region (3), wherein the predetermined constant K satisfies K1+K2=K.
  3. 3. The AR display module according to claim 1, wherein the waveguide lens module (2) further comprises: A first glass substrate (23), wherein the first waveguide layer (21) and the second waveguide layer (22) are respectively positioned at the left end and the right end of the same side of the first glass substrate (23); Dimming and focusing module (24), dimming and focusing module (24) set up in first waveguide layer (21) and second waveguide layer (22) keep away from one side of first glass substrate (23), first waveguide layer (21) and second waveguide layer (22) with form first air gap (25) between first glass substrate (23), form second air gap (26) in transition district (3) between first waveguide layer (21) and second waveguide layer (22), first waveguide layer (21) and second waveguide layer (22) with form third air gap (27) between dimming and focusing module (24).
  4. 4. An AR display module according to claim 3, wherein the dimming and focusing module (24) comprises: A glass separator (241), wherein the glass separator (241) is arranged on one side of the first waveguide layer (21) and the second waveguide layer (22), and forms the third air gap (27) with the first waveguide layer (21) and the second waveguide layer (22); -a concentric annular ITO layer (242), the concentric annular ITO layer (242) being arranged on a side of the glass separator (241) facing away from the third air gap (27); A liquid crystal layer (243), wherein dichroic dye molecules are arranged in the liquid crystal layer (243), and the liquid crystal layer (243) is arranged on one side of the concentric annular ITO layer (242) away from the glass partition plate (241); A planar ITO layer (244), the planar ITO layer (244) being disposed on a side of the liquid crystal layer (243) facing away from the concentric annular ITO layer (242); and a second glass substrate (245), wherein the second glass substrate (245) is arranged on one side of the planar ITO layer (244) away from the liquid crystal layer (243).
  5. 5. The AR display module according to claim 4, wherein the polarization switching component (12) includes a PBS polarizing beam splitter (121), an electrically controlled polarization switch (122), a transmission optical component (123) and a polarization beam splitter (124), and the PBS polarizing beam splitter (121), the electrically controlled polarization switch (122) and the polarization beam splitter (124) are sequentially arranged at intervals along the transmission direction of the polarized image beam; the PBS polarizing beam splitter (121) is configured to direct illumination light reflection to the Lcos display chip (11) and to split the polarized image beam transmission to output a polarized image beam; The electrically controlled polarization switch (122) is configured to receive the linearly polarized image beam and convert it into a first linearly polarized beam or a second linearly polarized beam and output alternately; the polarizing beam splitter (124) is configured to output the first linearly polarized light beam in a first direction, or Outputting the second linearly polarized light beam in a second direction different from the first direction; the first linearly polarized light beam and the second linearly polarized light beam are coupled into the first waveguide layer (21) and the second waveguide layer (22) through transmission optical components (123) in a one-to-one correspondence, respectively.
  6. 6. The AR display module set according to claim 5, wherein the transmission optical components (123) are provided in two groups, which are respectively and correspondingly disposed on transmission paths of the first linearly polarized light beam and the second linearly polarized light beam, and each group of the transmission optical components (123) comprises: A quarter wave plate (1231), the quarter wave plate (1231) being configured to convert the first linearly polarized light beam into first circularly polarized light, or Converting the second linearly polarized light beam into second circularly polarized light of a second handedness opposite to the first handedness; A coupling lens (1232), the coupling lens (1232) being configured to focus and couple the first circularly polarized light emitted by the quarter-wave plate (1231) into the coupling-in region of the first waveguide layer (21), or The coupling lens (1232) is configured to focus the second circularly polarized light emitted by the quarter wave plate (1231) and to couple it into the coupling-in region of the second waveguide layer (22).
  7. 7. An AR display device, characterized by comprising an AR display module according to any one of claims 4-6, a frame (4) and a connector (5); The waveguide lens module (2) is embedded in the mirror frame (4), a light machine bin (41) is arranged in the middle of the mirror frame (4), and the light machine module (1) is arranged in the light machine bin (41); One end of the connecting piece (5) is fixedly connected to one end of the upper portion of the glasses frame (4), the other end of the connecting piece protrudes in the horizontal direction, a screw hole is formed in the connecting piece (5), and the connecting piece (5) is connected to the AR glasses body through screw hole threads.
  8. 8. A control method of an AR display device for augmented reality display using an AR display device according to claim 7, comprising the steps of: s1, controlling a polarization switching assembly (12) in an optical machine module (1) to be in a first working state in a first time period, enabling the optical machine module (1) to output first rotary circularly polarized light carrying first eye image information, and enabling the first rotary circularly polarized light to be diffracted and emitted to a first eye by a first polarization volume grating (211) after being transmitted by a first waveguide layer (21); S2, in a second time period after the first time period, controlling the polarization switching assembly (12) to switch to a second working state, so that the optical machine module (1) outputs second rotary circularly polarized light carrying second eye image information, and the second rotary circularly polarized light propagates through the second waveguide layer (22) and is diffracted and emitted to a second eye by the second polarization volume grating (221); S3, repeating the step S1 and the step S2, so that the first time period and the second time period are alternately carried out, and the sum of the first time period and the second time period is smaller than the human eye persistence period, so that a single optical machine module (1) alternately projects independent images to two eyes respectively; S4, according to the display depth of the virtual image target, driving voltages with corresponding gradient distribution are applied to the concentric annular ITO layer (242), so that the dimming and focusing module (24) generates diopter matched with the target display depth; And S5, applying a common-mode bias voltage to the concentric annular ITO layer (242) according to the ambient light intensity information, changing the overall orientation of the dichroism dye molecules in the dimming and focusing module (24), and adjusting the transmittance of ambient light.
  9. 9. The method according to claim 8, wherein in step S4 and step S5, a lookup table is provided, and the actual driving voltage value of the concentric ring ITO layer (242) is determined according to the lookup table, wherein the lookup table contains the mapping relation among the target diopter, the target transmittance and the voltage values of the ring electrodes, so as to compensate the coupling effect between the focusing function and the dimming function.
  10. 10. The method for controlling an AR display device according to claim 8, wherein the determining mode of the target display depth in step S4 is at least one of the following modes: Determining according to virtual object depth information output by a rendering engine; determining according to the gaze point depth detected by the eye movement tracking module; And determining according to the preset depth value of the application scene.

Description

AR display module, AR display device and control method Technical Field The application relates to the technical field of AR display, in particular to an AR display module, an AR display device and a control method. Background In recent years, AR display systems designed based on planar waveguides with coupling elements have been greatly developed and widely used in military and commercial fields, and in AR devices, the above waveguide structure must satisfy the characteristics of light weight, small volume, high transparency and wide exit pupil, and as one of the basic components of a coupling waveguide near-to-eye display system, the coupling elements can determine important parameters such as field of view (FOV), coupling efficiency, color rendering, and the like. The prior art relates to an AR waveguide and AR equipment, wherein the AR waveguide comprises a first optical waveguide body, a first entrance pupil area, a first turning area, a second turning area, a first exit pupil area and a second exit pupil area, the second optical waveguide at least comprises a second optical waveguide body, a second entrance pupil area and a third exit pupil area, the projection of the second entrance pupil area to the surface of the first entrance pupil area is at least partially overlapped with the first entrance pupil area, the projection of the third exit pupil area to the surface of the first turning area or the second turning area is overlapped with the partial area of the first turning area or the second turning area, and therefore the brightness of one side edge of an image represented by the image light beam is improved by arranging the second optical waveguide so as to improve the brightness of the second exit pupil area, further the phenomenon that the brightness of the image edge area is lower is reduced, the display effect of the image is improved, and the experience of a user is further improved. The above and the prior art generally adopts a multilayer waveguide superposition mode to expand the total view angle, when the sub-view fields carried by each waveguide layer are spatially combined, the pixel gray values of each sub-view field in the joint area are fused and rendered frame by frame usually by relying on image processing software, and when the available calculation power of a processor is insufficient to complete the fusion operation within a single frame time window after the scene rendering is completed, the problems of processing delay accumulation, frame rate reduction and even frame dropping can be caused. Disclosure of Invention The application provides an AR display module, an AR display device and a control method, which can solve the problems of processing delay, frame rate reduction and even frame dropping caused by image processing software when field splicing is carried out. The technical scheme of the application is as follows, an AR display module comprises: The optical machine module comprises an Lcos display chip and a polarization switching component, wherein the Lcos display chip is used for outputting polarized image light beams, and the polarization switching component is used for alternately switching the polarization states of the polarized image light beams so as to enable the polarized image light beams to form first rotary circular polarized light or second rotary circular polarized light after being transmitted; a waveguide lens module comprising a first waveguide layer and a second waveguide layer, the first waveguide layer comprising a first polarization volume grating configured to diffract the first circularly polarized light, the second waveguide layer comprising a second polarization volume grating configured to diffract the second circularly polarized light; The projections of the first polarizing volume grating and the second polarizing volume grating on the waveguide lens module are overlapped with each other to form a transition zone, in the transition zone, the refractive index modulation depth of the first polarizing volume grating gradually decreases along the direction towards the second waveguide layer, and the refractive index modulation depth of the second polarizing volume grating gradually decreases along the direction towards the first waveguide layer so as to complement polarized image light beams emitted by the first waveguide layer and the second waveguide layer. By adopting the scheme, the refractive index modulation depth of the first polarized volume grating and the second polarized volume grating in the transition region gradually decreases along the direction of approaching each other, the diffraction emergent light intensity of the first waveguide layer in the transition region gradually decreases along with the position, the diffraction emergent light intensity of the second waveguide layer in the transition region gradually increases along with the position, and the two layers form a brightness complementary relation in the transition regio