WO2022068956A1 - 光学模组、近眼显示装置和光投射方法 - Google Patents
光学模组、近眼显示装置和光投射方法 Download PDFInfo
- Publication number
- WO2022068956A1 WO2022068956A1 PCT/CN2021/128391 CN2021128391W WO2022068956A1 WO 2022068956 A1 WO2022068956 A1 WO 2022068956A1 CN 2021128391 W CN2021128391 W CN 2021128391W WO 2022068956 A1 WO2022068956 A1 WO 2022068956A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- light
- unit
- phase
- beam splitter
- phase delay
- Prior art date
Links
- 230000003287 optical effect Effects 0.000 title claims abstract description 277
- 238000000034 method Methods 0.000 title claims description 27
- 230000010287 polarization Effects 0.000 claims description 139
- 230000005540 biological transmission Effects 0.000 claims description 63
- 238000011144 upstream manufacturing Methods 0.000 claims description 20
- 210000001508 eye Anatomy 0.000 claims description 9
- 230000031700 light absorption Effects 0.000 claims description 6
- 238000005266 casting Methods 0.000 claims 1
- 238000002834 transmittance Methods 0.000 abstract description 4
- 101100335307 Xenopus laevis foxe4 gene Proteins 0.000 description 20
- AVWQQPYHYQKEIZ-UHFFFAOYSA-K trisodium;2-dodecylbenzenesulfonate;3-dodecylbenzenesulfonate;4-dodecylbenzenesulfonate Chemical compound [Na+].[Na+].[Na+].CCCCCCCCCCCCC1=CC=C(S([O-])(=O)=O)C=C1.CCCCCCCCCCCCC1=CC=CC(S([O-])(=O)=O)=C1.CCCCCCCCCCCCC1=CC=CC=C1S([O-])(=O)=O AVWQQPYHYQKEIZ-UHFFFAOYSA-K 0.000 description 10
- 238000010586 diagram Methods 0.000 description 9
- 101150046160 POL1 gene Proteins 0.000 description 8
- 101100117436 Thermus aquaticus polA gene Proteins 0.000 description 8
- 230000008569 process Effects 0.000 description 8
- 230000008859 change Effects 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 4
- 101100224481 Dictyostelium discoideum pole gene Proteins 0.000 description 3
- 101150110488 POL2 gene Proteins 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000003384 imaging method Methods 0.000 description 3
- 230000003190 augmentative effect Effects 0.000 description 2
- 238000004364 calculation method Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 235000012771 pancakes Nutrition 0.000 description 2
- 201000009310 astigmatism Diseases 0.000 description 1
- 210000005252 bulbus oculi Anatomy 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 238000002310 reflectometry Methods 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
- G02B27/28—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00 for polarising
- G02B27/283—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00 for polarising used for beam splitting or combining
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N9/00—Details of colour television systems
- H04N9/12—Picture reproducers
- H04N9/31—Projection devices for colour picture display, e.g. using electronic spatial light modulators [ESLM]
- H04N9/3141—Constructional details thereof
- H04N9/3147—Multi-projection systems
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B26/00—Optical devices or arrangements for the control of light using movable or deformable optical elements
- G02B26/06—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the phase of light
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
- G02B27/01—Head-up displays
- G02B27/017—Head mounted
- G02B27/0172—Head mounted characterised by optical features
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B5/00—Optical elements other than lenses
- G02B5/30—Polarising elements
- G02B5/3083—Birefringent or phase retarding elements
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
- G03B21/00—Projectors or projection-type viewers; Accessories therefor
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N9/00—Details of colour television systems
- H04N9/12—Picture reproducers
- H04N9/31—Projection devices for colour picture display, e.g. using electronic spatial light modulators [ESLM]
- H04N9/3141—Constructional details thereof
- H04N9/315—Modulator illumination systems
- H04N9/3152—Modulator illumination systems for shaping the light beam
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N9/00—Details of colour television systems
- H04N9/12—Picture reproducers
- H04N9/31—Projection devices for colour picture display, e.g. using electronic spatial light modulators [ESLM]
- H04N9/3141—Constructional details thereof
- H04N9/315—Modulator illumination systems
- H04N9/3167—Modulator illumination systems for polarizing the light beam
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
- G02B27/01—Head-up displays
- G02B27/0101—Head-up displays characterised by optical features
- G02B2027/0118—Head-up displays characterised by optical features comprising devices for improving the contrast of the display / brillance control visibility
- G02B2027/012—Head-up displays characterised by optical features comprising devices for improving the contrast of the display / brillance control visibility comprising devices for attenuating parasitic image effects
Definitions
- the present invention generally relates to the field of optics, and in particular, to an optical module, a near-eye display device and a light projection method.
- optical modules are required to present images to the user.
- Existing optical modules are generally larger in size, and the thickness is often more than 30mm.
- users pay more and more attention to the volume and weight of products. Therefore, it is necessary to develop a small and light product to meet the needs of the market. demand.
- the optical module therein.
- many companies have launched VR or AR solutions based on pancake technology solutions, that is, optical modules based on folded optical paths.
- this optical module with a folded optical path mainly includes a mirror with a semi-reflective and semi-transparent function, a 1/4 phase retarder and a reflective polarizer, which are arranged in sequence. After the image source enters the mirror with the function of transflective and transflective, the light is refracted many times between the mirror, the phase retarder and the reflective polarizer, and finally exits from the reflective polarizer. Through this optical solution, the product volume is greatly reduced.
- the light entering the user's eyes also has some undesired light, which affects the user experience.
- the incident angle of the light is large, when the incident light passes through the reflective polarizer for the first time, it may not be completely reflected, but a large proportion of light leakage will occur, and part of the light will still pass through the reflective polarizer.
- the intensity of the leaked light may reach 38% of the signal light intensity along the optical axis, thereby affecting the user's viewing experience.
- an optical module comprising:
- Transflective layer receiving circularly polarized light or elliptically polarized light
- a second phase delay unit located downstream of the optical path of the transflective layer, to receive the transmitted circularly polarized light or elliptically polarized light and modulate it to output;
- a polarizing beam splitter arranged downstream of the optical path of the second phase delay unit, the polarizing beam splitter has a light transmission axis
- the optical module further includes a second phase compensation unit located between the second phase retardation unit and the polarizing beam splitter, wherein the optical axis of the second phase compensation unit is located at a distance from the polarizing beam splitter. In a plane orthogonal to the light transmission axis, or in a plane orthogonal to the reflection axis of the polarizing beam splitter.
- the optical module further includes a polarizer and a first phase retardation unit located upstream of the optical path of the transflective layer, the polarizer is configured to generate linearly polarized light, the The first phase delay unit receives linearly polarized light from the polarizer, modulates the linearly polarized light into circularly polarized light or elliptically polarized light, and then emits it to the transflective layer.
- the second phase compensating unit is configured such that: according to the polarization state distribution of the light beam at each incident angle first incident on the second phase compensating unit, it is modulated so that it is first incident on the second phase compensating unit.
- the polarization states of the light beams of each incident angle on the phase compensation unit after passing through the second phase compensation unit meet the conditions of being reflected by the polarization beam splitter.
- the first phase retardation unit is configured to cause a phase retardation of n* ⁇ +3/4 ⁇ , or n* ⁇ +1, of the polarization component of the linearly polarized light incident thereon along the optical axis direction /4 ⁇ phase retardation;
- the second phase retardation unit is configured to make the polarization component of the linearly polarized light incident thereon along the optical axis direction produce a phase retardation of n*pi+3/4pi, or a phase retardation of n* ⁇ +1/4 ⁇ Phase delay, where n is an integer.
- the light beam reflected by the polarizing beam splitter is transmitted through the second phase compensation unit and the second phase delay unit, partially reflected by the transflective layer, and transmitted through the second phase again.
- the polarization direction of the folded light beam reaching the polarization beam splitter is parallel to the light transmission axis of the polarization beam splitter.
- the first phase delay unit and the second phase delay unit are both positive phase delay units or both negative phase delay units, and satisfy the following relationship:
- ⁇ 1 is the angle through which the light transmission axis of the polarizer is rotated counterclockwise to the optical axis of the first phase delay unit when viewed against the optical path direction, and ⁇ 2 is viewed against the optical path direction, The light transmission axis of the polarizing beam splitter is rotated counterclockwise to the rotated angle of the optical axis of the second phase retardation unit.
- the first phase delay unit and the second phase delay unit are positive phase delay units or negative phase delay units of opposite types, and satisfy the following relationship:
- ⁇ 1 is the angle by which the light transmission axis of the polarizer rotates counterclockwise to the optical axis of the first phase delay unit when viewed against the optical path direction
- ⁇ 2 is the angle when viewed against the optical path direction
- the second phase compensating unit is configured such that: according to the polarization state distribution of the light beam at each incident angle first incident on the second phase compensating unit, it is modulated so that it is first incident on the second phase compensating unit.
- the polarization states of the light beams of each incident angle on the phase compensation unit after passing through the second phase compensation unit meet the conditions of being reflected by the polarization beam splitter.
- the optical module further includes a first phase compensation unit located between the first phase delay unit and the polarizer, wherein the optical axis of the first phase compensation unit is located at the same distance as the first phase compensation unit. in a plane orthogonal to the light transmission axis of the polarizer, or in a plane orthogonal to the light absorption axis of the polarizer.
- the first phase compensation unit is configured such that linearly polarized light incident thereon from the polarizer is modulated according to its polarization state distribution such that it is first incident on the polarizing beam splitter The polarization state of the beam meets the conditions for being reflected by the polarization beam splitter.
- the optical module further includes a lens, and the lens is disposed adjacent to the transflective layer.
- the transflective layer is attached to the surface of the lens.
- the present invention also relates to a near-eye display device, comprising:
- the optical module as described above is disposed downstream of the optical path of the display screen.
- the present invention also relates to a light projection method, comprising:
- S101 Receive circularly polarized light or elliptically polarized light through a transflective layer, and allow the circularly polarized light or elliptically polarized light to transmit at least partially;
- S102 Receive the transmitted circularly polarized light or elliptically polarized light through the second phase delay unit, modulate it, and then output it;
- S103 modulate and output the light beam from the second phase delay unit through a second phase compensation unit located downstream of the optical path of the second phase delay unit;
- S104 Receive the light beam from the second phase compensation unit through a polarizing beam splitter, the polarizing beam splitter is arranged downstream of the optical path of the second phase compensation unit, and the polarizing beam splitter has a light transmission axis, allowing the polarization direction to be different from the Part of the light beam parallel to the transmission axis of the polarizing beam splitter is transmitted, and the remaining part of the light beam is reflected back to the second phase retarder,
- the optical axis of the second phase compensation unit is located in a plane orthogonal to the light transmission axis of the polarization beam splitter, or in a plane orthogonal to the reflection axis of the polarization beam splitter.
- the second phase compensating unit is configured such that: according to the polarization state distribution of the light beam at each incident angle first incident on the second phase compensating unit, it is modulated so that it is first incident on the second phase compensating unit.
- the polarization states of the light beams of each incident angle on the phase compensation unit after passing through the second phase compensation unit meet the conditions of being reflected by the polarization beam splitter.
- the light projection method further includes:
- Linearly polarized light is generated through a polarizer
- the first phase delay unit receives linearly polarized light from the polarizer, converts it into circularly polarized light or elliptically polarized light, and protects it from being incident on the transflective layer.
- the light projection method further comprises,
- the linearly polarized light from the polarizer is modulated by a first phase compensation unit located between the first phase retardation unit and the polarizer, and then enters the first phase retardation unit, wherein the first phase retardation unit is The optical axis of a phase compensation unit is located in a plane orthogonal to the light transmission axis of the polarizer, or in a plane perpendicular to the light absorption axis of the polarizer, wherein the first phase compensation unit is configured such that: according to The polarization state distribution of the linearly polarized light incident thereon from the polarizer is modulated so that the polarization state of the light beam incident on the polarization beam splitter for the first time conforms to the condition of being reflected by the polarization beam splitter.
- ⁇ 1 is the angle through which the light transmission axis of the polarizer is rotated counterclockwise to the optical axis of the first phase delay unit when viewed against the optical path direction
- ⁇ 2 is viewed against the optical path direction , the light transmission axis of the polarizing beam splitter is rotated counterclockwise to the angle that the optical axis of the second phase delay unit is rotated.
- the light projection method is implemented by the optical module as described above.
- the optical module of the embodiment of the present invention can reduce the occurrence of light leakage in the folded optical path, especially some preferred embodiments can reduce or eliminate the light leakage in the folded optical path within a large angle range, which helps to improve the user's feeling effect.
- FIG. 1 shows a schematic diagram of an optical module based on a folded optical path
- FIG. 2 shows a schematic diagram of an optical module according to an embodiment of the first aspect of the present invention
- FIG. 3 shows a schematic diagram of an optical module according to another embodiment of the present invention.
- 4A, 4B, 4C and 4D are schematic diagrams showing optical parameters of an optical module according to an embodiment of the present invention.
- FIG. 5 shows a schematic diagram of an optical module according to Embodiment 1 of the present invention.
- 6A and 6B respectively show the polarization state change of the light beam incident at a specific angle of the optical module according to Embodiment 1 of the present invention
- 6C and 6D respectively show the distribution of the signal light and stray light intensity of the optical module according to Embodiment 1 of the present invention with different incident angles of the light;
- FIG. 7 shows a schematic diagram of an optical module according to Embodiment 2 of the present invention.
- FIG. 9 shows a schematic diagram of an optical module according to Embodiment 3 of the present invention.
- FIG. 10A shows the polarization state of the light beam of the optical module according to Embodiment 3 of the present invention
- 10B shows the distribution of the signal light and stray light intensity of the optical module according to Embodiment 3 of the present invention with different incident angles of the light;
- Figure 11 shows a light projection method according to an embodiment of the present invention
- Fig. 12 shows the optical module according to the first embodiment of the second aspect of the present invention
- FIG. 13 shows a schematic diagram of the optical path of the optical module according to the first embodiment of the second aspect of the present invention
- FIG. 14A shows the light leakage situation in the absence of the phase compensation unit
- FIG. 14B shows the light leakage situation in the case of adding the phase compensation unit according to the second aspect of the present invention
- Figure 15 shows an optical module according to a second embodiment of the second aspect of the invention
- Figure 16 shows an optical module according to a third embodiment of the second aspect of the present invention.
- FIG. 17 shows an optical module according to a fourth embodiment of the second aspect of the present invention.
- connection should be understood in a broad sense, for example, it may be a fixed connection or a detachable connection Connection, or integral connection: it can be a mechanical connection, an electrical connection or can communicate with each other; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal communication of two elements or the interaction of two elements relation.
- connection should be understood in a broad sense, for example, it may be a fixed connection or a detachable connection Connection, or integral connection: it can be a mechanical connection, an electrical connection or can communicate with each other; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal communication of two elements or the interaction of two elements relation.
- sheet and film should be understood in a broad sense, for example, it may be an independent optical element, or a film layer attached to a lens or a transparent substrate.
- a first feature "on” or “under” a second feature may include direct contact between the first and second features, or may include the first and second features Not directly but through additional features between them.
- the first feature being “above”, “over” and “above” the second feature includes that the first feature is directly above and diagonally above the second feature, or simply means that the first feature is level higher than the second feature.
- the first feature “below”, “below” and “beneath” the second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature has a lower level than the second feature.
- Figure 1 shows an optical module based on a folded optical path.
- the right side in the figure is the object side, for example, a display screen is placed, and the left side in the figure is the image side (observation side), that is, the position of the user's eyeball.
- the optical module as shown in FIG. 1 along the direction of the optical path (from the object side to the image side), it sequentially includes a quarter-wave plate 11 and a semi-transparent and semi-reflective layer 13 (attached on the lens 12 in FIG. 1 ). ), quarter wave plate 14, polarizing beam splitter 15.
- the light beam E1 (linearly polarized light) from the object side passes through the quarter-wave plate 11, the lens 12, the transflective layer 13 and the quarter-wave plate 14 in turn and then enters the polarization beam splitter 15.
- the light beam E3 incident on the polarizing beam splitter 15 is linearly polarized light, and the polarization direction is perpendicular to the transmission axis of the polarizing beam splitter 15, so theoretically, it should be reflected by the polarizing beam splitter 15, and then transmitted through the quarter-wave plate 14 and then be reflected by the polarizing beam splitter 15.
- the transflective layer 13 reflects, passes through the quarter-wave plate 14 again, and is incident on the polarizing beam splitter 15 again.
- the polarization direction of the polarized light E6 is parallel to the transmission axis of the polarizing beam splitter 15, so it can be transmitted through
- the polarizing beam splitter 15 is shown as "Signal" in FIG. 1 .
- part of the beam will be transmitted through the polarizing beam splitter 15 to form the “noise” shown in FIG. 1 , that is, light leakage.
- the inventors of the present application have found that the above problems can be solved by arranging one or more phase compensation units in the optical path. And further preferably, it can be further improved by combining the parameter settings of some elements in the optical module. Details are described below.
- FIG. 2 shows an optical module 20 according to an embodiment of the present invention, which will be described in detail below with reference to FIG. 2 .
- the optical module 20 includes a polarizer Pol, a first phase retardation unit QWP1, a transflective layer BS, a second
- the phase delay unit QWP2 and the polarization beam splitter PBS further include a second phase compensation unit RB, which is located between the second phase delay unit QWP2 and the polarization beam splitter PBS.
- the polarizer Pol is configured to receive the incident light beam and modulate it into linearly polarized light E1
- the first phase delay unit QWP1 is configured to receive the linearly polarized light E1 from the polarizer Pol and modulate it into circularly polarized light or Elliptical polarized light E2.
- the transflective layer BS is located downstream of the optical path of the first phase delay unit QWP1, and receives the circularly polarized light or elliptically polarized light E2, and makes it partially transmit and partially reflect.
- the second phase delay unit QWP2 is located downstream of the optical path of the transflective layer BS, the second phase compensation unit RB is located downstream of the optical path of the second phase delay unit QWP2, and the polarizing beam splitter PBS is arranged on the second phase compensation unit RB Downstream of the optical path, the polarizing beam splitter PBS has a light transmission axis.
- the working process of the optical module 20 shown in FIG. 2 is as follows.
- the polarizer Pol receives the incident light beam and emits linearly polarized light E1.
- the linearly polarized light E1 is modulated into circularly polarized light or elliptically polarized light E2 through the first phase delay unit QWP1, and the circularly polarized light or elliptically polarized light E2 is incident on the transflective layer BS.
- the transflective layer BS is located downstream of the optical path of the first phase retardation unit QWP1, and receives the circularly polarized light or elliptically polarized light E2, allowing the circularly polarized light or elliptically polarized light to transmit at least partially, and the present invention does not limit the transflective light
- the specific transmittance of the semi-reflective layer BS may be 50% or other ratios.
- the partially transmitted light beam is modulated into linearly polarized light E3 through the second phase delay unit QWP2, the linearly polarized light E3 is incident on the second phase compensation unit RB and is modulated into linearly polarized light E3', and the polarization direction of the linearly polarized light E3' is the same as the polarization beam splitter.
- the light transmission axis of PBS is vertical, so it is reflected by the polarizing beam splitter PBS and folded back, and then the folded beam is transmitted through the second phase compensation unit RB and the second phase delay unit QWP2 (circularly polarized light or elliptically polarized light E4) and is semi-transparent and semi-reflected.
- the layer BS reflects (circularly or elliptically polarized light E5), passes through the second phase retardation unit QWP2 (linearly polarized light E6) and the second phase compensation unit RB (linearly polarized light E6') again and is incident on the polarizing beam splitter PBS again.
- the polarizing beam splitter PBS is arranged downstream of the optical path of the second phase retardation unit QWP2, and the polarizing beam splitter has a light transmission axis TPBS, allowing part of the light beam whose polarization direction is parallel to the light transmission axis TPBS to transmit, and reflects the remaining part of the light beam back the second phase delay unit QWP2.
- the polarization direction of the polarized light E6' is parallel to the light transmission axis of the polarizing beam splitter PBS, so it can be transmitted through the polarizing beam splitter PBS. That is, the light beam reflected by the polarizing beam splitter PBS is transmitted through the second phase compensation unit RB and the second phase delay unit QWP2, partially reflected by the transflective layer BS, and transmitted through the second phase again.
- the retardation unit QWP2 and the second phase compensation unit RB, the polarization direction of the folded beam reaching the polarizing beam splitter PBS is parallel to the light transmission axis of the polarizing beam splitter PBS, so that it can transmit to form a signal (light).
- the light beams of each incident angle incident on the polarizing beam splitter PBS for the first time
- the polarization state of E3' meets or tries to meet the conditions of being reflected by the polarizing beam splitter PBS, which greatly reduces the intensity of light leakage and stray light, and the intensity of stray light can be reduced to 5% of the signal light intensity. Signal light will not be affected.
- the dots or arrows above the arrows used to indicate the light beams in FIG. 2 represent the corresponding polarization states of the light beams.
- the polarizer Pol and the first phase delay unit QWP1 may be integrated into a light source (eg, a screen) upstream of the optical module 20 . Meanwhile, the light beam incident on the first phase delay unit QWP1 may be linearly polarized light, or may be linearly polarized light with a certain circular polarization component.
- the optical module 20 of FIG. 2 includes a second phase compensation unit RB located between the second phase delay unit QWP2 and the polarizing beam splitter PBS.
- the optical axis of the second phase compensation unit RB is located in a plane orthogonal to the light transmission axis TPBS of the polarizing beam splitter PBS, or is reflected from the polarizing beam splitter PBS in the plane orthogonal to the axes.
- the second phase compensation unit RB is configured such that: according to the polarization state distribution of the light beam at each incident angle first incident on the second phase compensation unit RB, it is modulated, so that the first incident light beam is modulated.
- the polarization states of the light beams of each incident angle on the second phase compensation unit RB after passing through the second phase compensation unit RB meet the conditions of being reflected by the polarization beam splitter PBS.
- the second phase compensation unit RB makes the polarization states of the light beams of each incident angle incident on the polarizing beam splitter PBS for the first time meet the conditions of being reflected by the polarizing beam splitter, which is not necessarily
- the polarization state of the light beam incident on the polarizing beam splitter for the first time fully meets the conditions of being reflected, as long as the polarization state of a larger proportion of the light beams meets the conditions of being reflected (compared with the case where the phase compensation unit is not provided).
- orthogonal or perpendicular includes the case of 90 degrees between each other, but is not strictly limited to this, for example, within the range of 90° ⁇ 5°, it can be considered as “ Orthogonal” or “Vertical”.
- the first phase delay unit QWP1 is configured to cause the polarization component of the linearly polarized light incident thereon along the optical axis direction to generate a phase delay of n* ⁇ +3/4 ⁇ , or n* The phase retardation of ⁇ +1/4 ⁇ ;
- the second phase retardation unit QWP2 is configured to make the polarization component of the linearly polarized light incident thereon along the optical axis direction produce a phase retardation of n* ⁇ +3/4 ⁇ , or n* ⁇ + A phase delay of 1/4 ⁇ , where n is an integer.
- both the first phase delay unit QWP1 and the second phase delay unit QWP2 are quarter wave plates.
- a first phase compensation unit may also be disposed upstream of the optical path of the first phase delay unit QWP1 Unit RA.
- FIG. 3 shows the optical module 30 according to such an embodiment, wherein the first phase compensation unit RA is located between the first phase delay unit QWP1 and the polarizer Pol.
- the xyz coordinate system is also shown in Figure 3, in which the positive x direction is vertically inward on the paper, the positive y direction is vertically downward, and the horizontal left (from the object side to the image side) is the positive z direction (that is, along the optical path). direction).
- the optical axis of the first phase compensation unit RA is located in a plane orthogonal to the light transmission axis TPol of the polarizer Pol, or in a plane orthogonal to the light absorption axis of the polarizer Pol.
- the linearly polarized light E1 from the polarizer Pol passes through the first phase compensation unit RA, and then emerges linearly polarized light with a certain circular polarization component, and then passes through the first phase delay unit QWP1 to be Modulated as circularly or elliptically polarized light E2.
- the first phase compensation unit RA is configured such that the linearly polarized light incident thereon from the polarizer Pol in various directions is modulated according to its polarization state distribution, so that the first incident light is The polarization states of the light beams at each incident angle on the polarizing beam splitter meet the conditions for being reflected by the polarizing beam splitter.
- the first phase compensation unit RA makes the polarization states of the light beams of each incident angle incident on the polarizing beam splitter PBS for the first time meet the conditions of being reflected by the polarizing beam splitter, which is not necessarily
- the polarization state of the light beam incident on the polarizing beam splitter for the first time fully meets the conditions of being reflected, as long as the polarization state of a larger proportion of the light beams meets the conditions of being reflected (compared with the case where the phase compensation unit is not provided).
- the first phase compensation unit RA and the second phase compensation unit RB jointly compensate the phase of the light beam, wherein the first phase compensation unit RA is configured to The polarization state distribution of the linearly polarized light incident thereon from various directions modulates it, and the second phase compensation unit RB is configured to be configured according to the polarization state distribution of the light beams of each incident angle first incident on the second phase compensation unit RB. It is modulated so that the polarization state of the light beam incident on the polarizing beam splitter PBS for the first time conforms to the condition of being reflected by the polarizing beam splitter PBS.
- the optical modules 20 and 30 both include polarizers Pol, but the present invention is not limited thereto.
- the optical modules 20 and 30 may also not include polarizers Pol.
- the polarizers Pol may be upstream of the optical path.
- the light sources (such as screens) are integrated together, which are all within the protection scope of the present invention.
- the phase compensation amounts of the first phase compensation unit RA and the second phase compensation unit RB are not limited to specific values, as long as they can help improve the ratio of the reflected light when the light beam is first incident on the polarizing beam splitter PBS, that is, Can.
- the first phase compensation unit RA and the second phase compensation unit may both be composed of a single phase compensation plate, or may include a plurality of phase compensation plates, the specific number of which is not limited in the present invention.
- the first phase compensation unit RA can be performed after the wavelength, polarizer Pol, the optical parameters of the first phase delay unit QWP1, the second phase delay unit QWP2, and the PBS and the device orientation parameters are given.
- the design of the second phase compensation unit RB only needs to improve the ratio of the reflected light when the light beam is first incident on the polarization beam splitter PBS, compared to when the first phase compensation unit RA and the second phase compensation unit RB are not added. The specific calculation method will not be repeated here.
- the optical module further includes a lens, and the lens is disposed adjacent to the transflective layer BS.
- the transflective layer BS can be attached to the surface of the lens. .
- Positive phase retardation unit Make the polarization component of the incident beam along the optical axis to generate a phase retardation of N* ⁇ +1/4 ⁇ , where N is an integer;
- Negative phase retardation unit Make the polarization component of the incident beam along the optical axis to produce a phase retardation of M* ⁇ +3/4 ⁇ , where M is an integer.
- ⁇ 1 is the polarization direction D1 counterclockwise when the linearly polarized light incident on the first phase delay unit QWP1 is normally incident when viewed against the optical path direction (that is, viewed from left to right in FIG. 2 or FIG. 3 )
- ⁇ 2 is viewed against the optical path direction
- the light transmission axis TPBS of the polarizing beam splitter rotates counterclockwise to the second phase delay unit QWP2.
- the light transmission axis of the polarizer Pol is parallel to the polarization direction D1 when the linearly polarized light incident on the first phase retardation unit QWP1 is normally incident, so ⁇ 1 is opposite to Viewed from the direction of the optical path (ie, viewed from left to right in FIG. 2 ), the light transmission axis of the polarizer rotates counterclockwise to the angle through which the optical axis TQWP1 of the first phase delay unit QWP1 rotates.
- Fig. 4A shows the case where ⁇ 1 is 45 degrees
- Fig. 4B shows the case where ⁇ 1 is 135 degrees
- Fig. 4C shows the case where ⁇ 2 is 45 degrees
- Fig. 4D shows the case where ⁇ 2 is 135 degrees situation.
- the polarization direction D1 is the polarization direction of the linearly polarized light.
- the polarization direction corresponds to the light transmission axis of the polarizer.
- the first phase compensating unit RA by adding the first phase compensating unit RA, the second phase compensating unit RB, setting the type of the first phase delay unit QWP1 and the second phase delay unit QWP2, and the optical axis angle relationship, it is possible to make the first incident incident
- the polarization state of the light beams of each incident angle on the polarizing beam splitter PBS conforms to or as far as possible meets the conditions of being reflected by the polarizing beam splitter PBS, that is, the polarization direction is perpendicular to or as perpendicular to the light transmission of the polarizing beam splitter PBS as possible.
- the axis TPBS is either parallel or as parallel as possible to the reflection axis of the polarizing beam splitter PBS.
- the light beams incident on the polarizing beam splitter for the first time (first time) and the beams incident on the polarizing beam splitter for the second time will be distinguished.
- the light beam E1 is modulated into a light beam E3' after passing through the first phase compensation unit RA, the first phase delay unit QWP1, the transflective layer BS, and the second phase delay unit QWP2, and is incident on the polarization beam splitter PBS,
- the light beam E3' is called the light beam incident on the polarization beam splitter PBS for the first time (first time)
- the light beam E3 is called the light beam incident on the second phase compensation unit RB for the first time (first time)
- the light beam E6' is called the second incident light beam on the polarization beam splitter
- the light beam on the sheet, the light beam E6 is called the light beam that is incident on the second phase compensation unit RB twice, and the light beams E4, E5, E6 and E6' can
- the technical solution of the present invention can make the ratio of the light beam incident on the polarizing beam splitter PBS transmitted through the polarizing beam splitter PBS for the first time to be smaller, and the resulting noise (miscellaneous) astigmatism) is smaller.
- Most of the light beams are reflected and form a folded beam, and when it is incident on the polarizing beam splitter PBS for the second time, its polarization direction is parallel to the light transmission axis TPBS of the polarizing beam splitter PBS or as parallel as possible, so it can transmit and form a signal ( Light).
- the first phase compensation unit RA and the second phase compensation unit RB are named along the optical path direction of the optical module, which does not mean that the first phase compensation unit RA is necessarily provided.
- the example does not include the first phase compensation unit RA.
- Example 1 The optical path structure of Example 1 is shown in FIG. 5 , in which there is a light-emitting screen upstream of the optical path of the absorbing polarizer Pol.
- the specific parameters of the optical path structure of Embodiment 1 are as follows:
- the light transmission axis of the absorptive polarizer Pol is parallel to the x-axis;
- the transmissivity of the transflective layer BS is 50%, and the reflectivity is 50%;
- the transmission axis of the polarizing beam splitter PBS is parallel to the y-axis.
- Incidence angle ⁇ and azimuth angle of light is defined as follows: ⁇ is the angle between the ray and the positive direction of the z-axis, It is the angle between the projection of the light in the xy plane and the positive direction of the x-axis.
- FIG. 6C and FIG. 6D The intensity distribution of the signal light and stray light with different incident angles of the light is shown in FIG. 6C and FIG. 6D . It can be seen from the figure that when the ⁇ is less than 30o, the intensity of the signal light is much greater than that of the stray light, and the light leakage phenomenon in this area is not obvious.
- the rotation axis composed of the fast axis and the slow axis of the first phase delay unit QWP1 is the magenta line F O S O
- the rotation axis composed of the fast axis and the slow axis of QWP2 is the red line F N S N , such as As shown in Figure 6A
- it When it is incident, it first passes through the first phase delay unit QWP1 and the second phase delay unit QWP2 for the first time and then the polarization is modulated.
- the process is represented on the Poincare sphere as: QWP1 modulation process - M point around the magenta line F N S N rotates 90° clockwise to point N; QWP2 modulation process - rotate point N 90° clockwise around the red line F O S O to point O. (Clockwise rotation refers to clockwise rotation when looking from the F end to the S end for the straight line FS)
- the incident light passes through the absorbing polarizer Pol, the first phase retardation unit QWP1, and the second phase retardation unit QWP2 for the first time in sequence.
- the angle is relatively large, so the light that first reaches the polarizing beam splitter PBS will not be completely absorbed, and a certain degree of light leakage will occur.
- FIG. 7 shows the optical path structure of the second embodiment.
- the optical path structure of Embodiment 2 has the following differences: a second phase compensation unit RB is added.
- the first phase delay unit QWP1 is a positive phase delay unit.
- the second phase compensation unit RB may have various configurations.
- the parameters of the second phase compensation unit RB selected in this embodiment are shown in the following table, which includes a phase retardation plate B1 and a phase retardation plate B2 superimposed along the direction of the optical path.
- the parameters of the phase retardation plate B1 are as follows: n o ⁇ n e , the optical axis direction is parallel to the x-axis, and the phase retardation is 133 nm.
- the parameters of the phase retarder B2 are as follows: n o ⁇ n e , the optical axis direction is parallel to the z-axis, and the phase retardation amount is 104 nm.
- Phase retarder B1 Phase retarder B2 Optical axis direction parallel to the x-axis parallel to the z-axis Retardance (phase delay amount) 133nm 104nm type n o ⁇ n e n o ⁇ n e
- Fig. 8B The distribution of the intensity of stray light with different incident angles of the light is shown in Fig. 8B.
- this embodiment greatly reduces the light leakage in the folded optical path, and the intensity of the leakage light is reduced to 10% of the original.
- FIG. 9 shows the optical path structure of Embodiment 3.
- FIG. Compared with Embodiment 1, the optical path structure of Embodiment 3 has the following differences: a first phase compensation unit RA and a second phase compensation unit RB are added.
- the first phase delay unit QWP1 is a positive phase compensation unit.
- the first phase compensation unit RA may have various configurations.
- the selected parameters of the first phase compensation unit RA in this embodiment are as follows: it includes a phase retardation plate A1 and a phase retardation plate A2 superimposed along the direction of the optical path.
- the parameters of the phase retardation plate A1 are as follows: n o ⁇ n e , the optical axis direction is parallel to the x-axis, and the phase retardation amount is 206 nm.
- the parameters of the retardation plate A2 are as follows: n o ⁇ n e , the optical axis direction is parallel to the y-axis, and the phase retardation amount is 85 nm.
- Phase retarder A1 Phase retarder A2 Optical axis direction parallel to the x-axis parallel to the y-axis Retardance (phase delay amount) 206nm 85nm type n o ⁇ n e n o >n e
- the second phase compensation unit RB may have various configurations.
- the parameters of the second phase compensation unit RB selected in this implementation are as follows: it includes a phase retarder B1 and a phase retarder B2 superimposed along the direction of the optical path.
- the parameters of the phase retardation plate B1 are as follows: n o > ne , the optical axis direction is parallel to the x-axis, and the phase retardation is 85 nm.
- the parameters of the phase retardation plate B2 are as follows: n o > ne , the optical axis direction is parallel to the y-axis, and the phase retardation amount is 206 nm.
- Phase retarder B1 Phase retarder B2 Optical axis direction parallel to the x-axis parallel to the y-axis Retardance (phase delay amount) 85nm 206nm type n o >n e n o >n e
- Fig. 10B The distribution of the intensity of stray light with different incident angles of the light is shown in Fig. 10B.
- the light leakage in the folded optical path is greatly reduced in this embodiment, and the light leakage intensity is reduced to 7% of the original.
- the optical module according to the embodiment of the present invention can reduce the occurrence of light leakage in the folded optical path.
- the present invention also relates to a near-eye display device, comprising: a display screen; and the optical module 20, 30 or 40 as described above, and the optical module 20, 30 or 40 is arranged downstream of the optical path of the display screen.
- the near-eye display device is such as an augmented reality AR device, a virtual reality VR device, or other types of mixed reality MR devices.
- FIG. 11 shows a light projection method 100 according to an embodiment of the present invention, which will be described in detail below with reference to FIG. 16 .
- step S101 receiving circularly polarized light or elliptically polarized light through the transflective layer, and allowing the circularly polarized light or elliptically polarized light to transmit at least partially;
- step S102 the transmitted circularly polarized light or elliptically polarized light is received by the second phase delay unit, modulated and then emitted;
- step S103 modulate and output the light beam from the second phase delay unit by the second phase compensation unit located downstream of the optical path of the second phase delay unit;
- step S104 receiving the light beam from the second phase compensation unit through a polarizing beam splitter, the polarizing beam splitter is arranged downstream of the optical path of the second phase compensation unit, the polarizing beam splitter has a light transmission axis, allowing a polarization direction Part of the beam parallel to the transmission axis of the polarizing beam splitter is transmitted, and the remaining part of the beam is reflected back to the second phase retarder,
- the optical axis of the second phase compensation unit is located in a plane orthogonal to the light transmission axis of the polarization beam splitter, or in a plane orthogonal to the reflection axis of the polarization beam splitter.
- the second phase compensation unit is configured such that: according to the polarization state distribution of the light beams at each incident angle first incident on the second phase compensation unit, it is modulated, so that the first incident light beams are The polarization states of the light beams of each incident angle on the second phase compensation unit after passing through the second phase compensation unit meet the conditions of being reflected by the polarization beam splitter.
- the light projection method further comprises:
- Linearly polarized light is generated through a polarizer
- the first phase delay unit receives linearly polarized light from the polarizer, converts it into circularly polarized light or elliptically polarized light, and protects it from being incident on the transflective layer.
- the light projection method further comprises:
- the linearly polarized light from the polarizer is modulated by a first phase compensation unit located between the first phase retardation unit and the polarizer, and then enters the first phase retardation unit, wherein the first phase retardation unit is The optical axis of a phase compensation unit is located in a plane orthogonal to the light transmission axis of the polarizer, or in a plane perpendicular to the light absorption axis of the polarizer, wherein the first phase compensation unit is configured such that: according to The polarization state distribution of the linearly polarized light incident thereon from the polarizer is modulated so that the polarization state of the light beam incident on the polarization beam splitter for the first time conforms to the condition of being reflected by the polarization beam splitter.
- ⁇ 1 is the angle through which the light transmission axis of the polarizer is rotated counterclockwise to the optical axis of the first phase delay unit when viewed against the optical path direction
- ⁇ 2 is viewed against the optical path direction , the light transmission axis of the polarizing beam splitter is rotated counterclockwise to the angle that the optical axis of the second phase delay unit is rotated.
- the light projection method is implemented by the optical module 20 or 30 as described above.
- the optical module 10 includes a lens (a first lens unit), and the optical module may also include a plurality of lens units, which will be described in detail below with reference to the accompanying drawings.
- FIG. 12 shows an optical module 40 according to an embodiment of the present invention, which will be described in detail below with reference to FIG. 12 .
- the optical module 40 includes a first lens unit LENS1, a transflective layer BS, a first lens unit LENS1, a transflective layer BS, a Two lens units LENS2, a second phase delay unit QWP2, a second phase compensation unit RB and a polarizing beam splitter PBS.
- a display screen 11 is provided upstream of the optical path of the optical module 40 , and the light emitted by the display screen 11 is incident on the optical module 40 , folds inside the optical module 40 and finally exits, and enters the human eye. imaging.
- the light emitted by the display screen 11 is preferably circularly polarized light or elliptically polarized light.
- the specific working manner of the optical module 40 will be described in detail below.
- the transflective layer BS is located downstream of the optical path of the first lens unit LENS1, and is attached to the surface of the first lens unit LENS1.
- the transflective layer BS may also be located upstream of the optical path of the first lens unit LENS1, or may have a certain interval from the first lens unit LENS1, which are all within the scope of the present invention.
- the second phase retardation unit QWP2, the second phase compensation unit RB and the polarizing beam splitter PBS are sequentially stacked on the surface of the second lens unit LENS2, and these optical components may also be spaced apart from each other. , and will not be repeated here.
- the first lens unit LENS1 and the second lens unit LENS2 are configured to image the image light incident on the first lens unit LENS1 into the user's eyes downstream of the second lens unit LENS2.
- the first lens unit LENS1 and the second lens unit LENS2 can image the content of the display screen 11 into the human eye.
- the first lens unit LENS1 can adjust the diopter of the optical module.
- the first lens unit LENS1 and the second lens unit LENS2 may be composed of a single lens, or may include a lens group, which are all within the scope of the present invention.
- FIG. 13 shows the working process of the optical module 40 of FIG. 12 , which will be described in detail below with reference to FIG. 13 .
- the display screen 11 emits circularly polarized light or elliptically polarized light E2 , and the circularly polarized light or elliptically polarized light E2 passes through the first lens unit LENS1 and enters the transflective layer BS.
- the transflective layer BS is located downstream of the optical path of the first lens unit LENS1, and receives the circularly polarized light or elliptically polarized light E2, allowing the circularly polarized light or elliptically polarized light E2 to transmit at least partially, and the present invention does not limit the transflective light
- the specific transmittance of the semi-reflective layer BS may be 50% or other ratios.
- the partially transmitted light beam E2 then passes through the second lens unit LENS2 and is incident on the second phase delay unit QWP2.
- the first lens unit LENS1, the transflective layer BS and the second lens unit LENS2 do not change the polarization state of the light beam, so the first lens unit LENS1, the transflective layer BS and the second lens unit
- the beams upstream and downstream of the optical path of LENS2 are denoted by E2.
- the light beam E2 is modulated into a linearly polarized light E3 after passing through the second phase delay unit QWP2, and the linearly polarized light E3 is incident on the second phase compensation unit RB and is modulated into a linearly polarized light E3', and the polarization direction of the linearly polarized light E3' is the same as the polarization beam splitter PBS.
- the light transmission axis is vertical, so it is reflected by the polarizing beam splitter PBS and folded back, and then the folded beam is transmitted through the second phase compensation unit RB and the second phase delay unit QWP2 (circularly polarized light or elliptically polarized light E4, and the display screen 11 emits light.
- the polarization of the light E2 is different, one of which is right-handed circularly (elliptically) polarized light, and the other is left-handed circularly (elliptically) polarized light), which is partially reflected by the transflective layer BS after passing through the second lens unit LENS2 (circularly polarized light or
- the elliptically polarized light E5) passes through the second phase retardation unit QWP2 (linearly polarized light E6) and the second phase compensation unit RB (linearly polarized light E6') again and is incident on the polarization beam splitter PBS again.
- the polarizing beam splitter PBS is arranged downstream of the optical path of the second phase retardation unit QWP2, and the polarizing beam splitter PBS has a light transmission axis TPBS, allowing part of the light beam whose polarization direction is parallel to the light transmission axis TPBS to transmit, and reflects the rest of the light beam back to the second phase delay unit QWP2.
- the polarization direction of the polarized light E6' is parallel to the light transmission axis of the polarizing beam splitter PBS, so it can be transmitted through the polarizing beam splitter PBS.
- the light beam reflected by the polarizing beam splitter PBS is transmitted through the second phase compensation unit RB and the second phase delay unit QWP2, partially reflected by the transflective layer BS, and transmitted again through the The second phase delay unit QWP2 and the second phase compensation unit RB, the polarization direction of the folded beam reaching the polarizing beam splitter PBS is parallel to the light transmission axis of the polarizing beam splitter PBS, so that it can transmit and form a signal (light ), imaged in the human eye.
- each incident incident on the polarizing beam splitter PBS for the first time is made.
- the polarization state of the beam E3' of the angle meets or tries to meet the conditions of being reflected by the polarizing beam splitter PBS, which greatly reduces the intensity of light leakage and stray light, and the intensity of stray light can be reduced to 5% of the signal light intensity. , while basically not affecting the signal light.
- the dots or arrows above the arrows used to indicate the light beams in FIG. 13 represent the corresponding polarization states of the light beams.
- the optical axis of the second phase compensation unit RB is located in a plane orthogonal to the light transmission axis TPBS of the polarizing beam splitter PBS, or is reflected from the polarizing beam splitter PBS in the plane orthogonal to the axes.
- the second phase compensation unit RB is configured such that: according to the polarization state distribution of the light beam at each incident angle first incident on the second phase compensation unit RB, it is modulated, so that the first incident light beam is modulated.
- the polarization states of the light beams of each incident angle on the second phase compensation unit RB after passing through the second phase compensation unit RB meet the conditions of being reflected by the polarization beam splitter 16 .
- the second phase compensation unit RB makes the polarization states of the light beams of each incident angle incident on the polarizing beam splitter PBS for the first time meet the conditions of being reflected by the polarizing beam splitter PBS, not It is necessary to make the polarization state of the light beam incident on the polarizing beam splitter PBS completely meet the conditions of being reflected, as long as the polarization state of a larger proportion of the light beam meets the conditions of being reflected (compared with the case where the phase compensation unit is not set) ).
- ⁇ represents the wavelength of the incident light.
- Table I shows a combination of lens parameters of the optical module of the first embodiment of the present invention (where the upstream of the optical path is "front”, and the downstream of the optical path is "rear”).
- the second phase compensation unit RB may have various configurations.
- the second phase compensation unit includes a phase retarder A and a phase retarder B superimposed along the direction of the optical path.
- the parameters of the phase retarder A are as follows: no ⁇ ne, the optical axis direction is parallel to its plane and perpendicular to the transmission axis of the polarizing beam splitter PBS, and the phase retardation is 80nm;
- the parameters of the phase retarder B are as follows: no>ne, the light The axis direction was parallel to its plane and parallel to the light transmission axis of the polarizing beam splitter PBS, and the phase retardation amount was 80 nm.
- FIG. 14A and 14B show comparative schematic diagrams of light leakage cases. According to the prior art, in the absence of a phase compensation unit, there will be serious light leakage in a large field of view (as shown in FIG. 14A ); while according to the first embodiment of FIG. 12 and FIG. 13 of the present invention, by adding With the phase compensation unit, the light leakage can be reduced to 4.3% (as shown in FIG. 14B ).
- FIG. 15 shows an optical module 40 according to a second embodiment of the present invention.
- the following description focuses on the differences from the embodiment in FIG. 12 , and the similarities will not be repeated.
- the transflective layer BS is located upstream of the optical path of the first lens unit LENS1 , and is attached to the surface upstream of the optical path of the first lens unit LENS1 .
- the second lens unit LENS2 is located downstream of the optical path of the polarization beam splitter PBS, and a second polarizer POL2 is also disposed between the polarization beam splitter PBS and the second lens unit LENS2.
- Table II below shows a combination of lens parameters of the optical module of the second embodiment of the present invention (where the upstream of the optical path is "front”, and the downstream of the optical path is "rear”).
- the working manner of the optical module 40 in the embodiment of FIG. 15 is basically the same as that shown in FIG. 13 , and details are not repeated here.
- FIG. 16 shows an optical module 40 according to a third embodiment of the present invention.
- the second lens unit LENS2 includes sub-lenses LENS2-1 and LENS2-2.
- the second lens unit LENS2 is located upstream of the optical path of the second phase delay unit QWP2, and is located in the transflective layer BS. Downstream of the light path.
- the optical module 40 in FIG. 16 further includes a second polarizer POL2 located downstream of the optical path of the polarizing beam splitter PBS.
- the optical module 40 further includes a first polarizer POL1 and a first phase delay unit QWP1 located between the display screen 11 and the first lens unit LENS1.
- the first polarizer POL1 receives the light beam from the display screen 11 and emits linearly polarized light, which is modulated into circularly polarized light or elliptically polarized light E2 through the first phase delay unit QWP1 and incident on the first lens unit LENS1.
- Table III shows a combination of lens parameters of the optical module of the third embodiment of the present invention (where the upstream of the optical path is "front”, and the downstream of the optical path is "rear”).
- FIG. 17 shows the optical module 40 according to the fourth embodiment of the present invention, wherein the second lens unit LENS2 includes sub-lenses LENS2-1 and LENS2-2.
- the optical module 40 sequentially includes a transflective layer BS, a first lens unit LENS1, a second lens unit LENS2 (sub-lenses LENS2-1 and LENS2-2), and a second phase retardation along the optical path direction.
- Table IV shows a combination of lens parameters of the optical module of the fourth embodiment of the present invention (where the upstream of the optical path is "front”, and the downstream of the optical path is "rear”).
- the display screen 11 may also constitute a part of the optical module 40 .
- the position of the second lens unit LENS2 can be set flexibly, as long as the second lens unit LENS2 is located downstream of the optical path of the transflective layer BS.
- the second phase retardation unit QWP2 is configured to cause a phase retardation of n* ⁇ +3/4 ⁇ , or n* ⁇ + A phase delay of 1/4 ⁇ , where n is an integer.
- the first phase retardation unit QWP1 is configured to cause the polarization component of the linearly polarized light incident thereon along the optical axis direction to generate n* A phase delay of ⁇ +3/4 ⁇ , or a phase delay of n* ⁇ +1/4 ⁇ .
- both the second phase delay unit QWP2 and the first phase delay unit QWP1 are quarter wave plates.
- the optical module 40 may not include the first polarizer POL1.
- the first polarizer POL1 may be integrated with the light source (such as the display screen 11) upstream of the optical path, which are all within the scope of the present invention. within the scope of protection.
- the first polarizer POL1 and the first phase delay unit QWP1 can be simultaneously integrated in the light source (display screen 11 ).
- phase compensation amount of the second phase compensation unit RB is not limited to a specific value, as long as it can help to improve the reflected ratio of the light beam when it first enters the polarization beam splitter PBS.
- the second phase compensation unit RB may be composed of a single phase compensation plate, or may include a plurality of phase compensation plates, the specific number of which is not limited in the present invention.
- the optical parameters of the first polarizer POL1, the first phase delay unit QWP1, the second phase delay unit QWP2, the polarization beam splitter PBS and the device orientation parameters are given, the first The design of the two-phase compensation unit RB only needs to be able to improve the ratio of the reflected light when the light beam is first incident on the polarizing beam splitter PBS compared to when the second phase compensation unit RB is not added. The specific calculation method will not be repeated here.
- Positive phase retardation unit Make the polarization component of the incident beam along the optical axis to generate a phase retardation of N* ⁇ +1/4 ⁇ , where N is an integer;
- Negative phase retardation unit Make the polarization component of the incident beam along the optical axis to produce a phase retardation of M* ⁇ +3/4 ⁇ , where M is an integer.
- ⁇ 1 and ⁇ 2 are as defined in the first aspect of the invention.
- the relationship between the angles ⁇ 1 and ⁇ 2 has been described above, and those skilled in the art can easily understand that the above equation allows errors within the acceptable range of the project, for example, when the difference between the two and the target angle is within the range of plus or minus 5 degrees. can be considered to satisfy the above equation.
- the light transmission axis of the first polarizer POL1 is parallel to the polarization direction D1 when the linearly polarized light incident on the first phase retardation unit QWP1 is normally incident, so ⁇ 1 Viewed against the optical path direction (ie, viewed from left to right in the figure), the light transmission axis of the first polarizer rotates counterclockwise to the angle through which the optical axis TQWP1 of the first phase delay unit QWP1 rotates.
- the light beams incident on the polarizing beam splitter PBS for the first time (first time) and the beams incident on the polarizing beam splitter plate PBS for the second time will be distinguished. Referring to Fig.
- the light beam E3' is called the light beam incident on the polarizing beam splitter PBS for the first time (first time)
- the light beam E3 is called the light beam incident on the second phase compensation unit RB for the first time (first time);
- the light beam E6' is called the second time
- the light beam incident on the polarizing beam splitter PBS, the light beam E6 is called the light beam incident on the second phase compensation unit RB twice
- the light beams E4, E5, E6 and E6' can all be called folded light beams.
- the technical solution of the present invention can make the ratio of the light beam incident on the polarizing beam splitter transmitted through the polarizing beam splitter for the first time to be smaller, so the generated noise (stray light) is lower. Small. Most of the light beams are reflected and form a folded beam.
- its polarization direction is parallel or as parallel as possible to the light transmission axis TPBS of the polarizing beam splitter, so it can transmit and form a signal (light).
- the imaging effect in the human eye can be enhanced, such as improving the picture clarity or increasing the image field angle, and also improving the imaging mode.
- the focal length of the group makes the module lighter and thinner, and the diopter of the optical module can be adjusted to meet the naked eye observation needs of different myopic people.
- the present invention also relates to a near-eye display device, comprising: a display screen and the above-mentioned optical module, wherein the optical module is arranged downstream of the optical path of the display screen.
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Polarising Elements (AREA)
- Projection Apparatus (AREA)
Abstract
一种光学模组(20),包括:半透半反层(BS),接收圆偏光或椭圆偏光(E2);第二相位延迟单元(QWP2),位于半透半反层(BS)的光路下游,以接收透射的圆偏光或椭圆偏光并调制后出射;和偏振分光片(PBS),设置在第二相位延迟单元(QWP2)的光路下游,偏振分光片(PBS)具有透光轴,其中光学模组(20)还包括位于第二相位延迟单元(QWP2)和偏振分光片(PBS)之间的第二相位补偿单元(RB),其中第二相位补偿单元(RB)的光轴位于与偏振分光片(PBS)的透光轴正交的平面内、或与偏振分光片(PBS)的反光轴正交的平面内。通过这种光学模组(20),能够减少折叠光路中漏光的发生,尤其是能够在大角度范围内减少或者消除折叠光路中的漏光,有助于提高用户的感受效果。
Description
本发明大致涉及光学领域,尤其涉及一种光学模组、近眼显示装置以及光投射方法。
在虚拟显示(VR)、增强显示(AR)、其他混合显示技术中,需要采用光学模组来向用户呈现图像。现有的光学模组一般体积较大,厚度往往在30mm以上,随着科技的进步,用户越来越重视产品的体积以及重量,因此,需要研发一种体积小、重量轻的产品以满足市场的需求。其中,受限最大的因素为其中的光学模组。为了解决上述的体积和重量问题,许多公司推出基于pancake技术方案的VR或者AR方案,即基于折叠光路的光学模组。
在这种折叠光路的光学模组中,主要包括依序设置的具有半反半透功能的镜片、1/4相位延迟片以及反射式偏振片。图像源进入半反半透功能的镜片之后,光线在镜片、相位延迟片以及反射式偏振片之间多次折返的方式,最终从反射式偏振片射出。通过此种光学方案,极大的缩小了产品体积。
但在目前的pancake方案中,入射到用户眼中的光线,除了用户期望的光线之外,还有一些非期望的光线,影响用户体验。尤其是当光线的入射角较大时,入射光第一次经过反射式偏振片时,不一定会被完全反射,而是会产生较大比例的漏光现象,一部分光仍然会通过反射式偏振片进入用户的眼中,漏光的强度可能会达到沿着光轴的信号光强度的38%,从而影响用户的观看体验。
背景技术部分的内容仅仅是公开人所知晓的技术,并不当然代表本领域的现有技术。
发明内容
有鉴于现有技术的至少一个问题,本发明提供一种光学模组,包括:
半透半反层,接收圆偏光或椭圆偏光;
第二相位延迟单元,位于所述半透半反层的光路下游,以接收所述透射的圆偏光或椭圆偏光并调制后出射;和
偏振分光片,设置在所述第二相位延迟单元的光路下游,所述偏振分光片具有透光轴,
其中所述光学模组还包括位于所述第二相位延迟单元和所述偏振分光片之间的第二相位补偿单元,其中所述第二相位补偿单元的光轴位于与所述偏振分光片的透光轴正交的平面内、或与所述偏振分光片的反光轴正交的平面内。
根据本发明的一个方面,所述的光学模组,还包括位于所述半透半反层的光路上游的偏光片和第一相位延迟单元,所述偏光片配置成可产生线偏光,所述第一相位延 迟单元从所述偏光片接收线偏光并将其调制为圆偏光或椭圆偏光后出射到所述半透半反层。
根据本发明的一个方面,所述第二相位补偿单元配置成使得:根据初次入射到第二相位补偿单元上的各入射角的光束的偏振态分布,对其进行调制,使得初次入射到第二相位补偿单元上的各入射角的光束透过所述第二相位补偿单元后的偏振态符合被所述偏振分光器反射的条件。
根据本发明的一个方面,所述第一相位延迟单元配置成可令入射到其上的线偏光沿光轴方向的偏振分量产生n*λ+3/4λ的相位延迟、或n*λ+1/4λ的相位延迟;第二相位延迟单元配置成可令入射到其上的线偏光沿光轴方向的偏振分量产生n*pi+3/4pi的相位延迟、或n*λ+1/4λ的相位延迟,其中n为整数。
根据本发明的一个方面,被所述偏振分光片反射的光束透射通过所述第二相位补偿单元、第二相位延迟单元,被所述半透半反层部分反射,再次透射通过所述第二相位延迟单元和第二相位补偿单元,到达所述偏振分光片的折返光束的偏振方向与所述偏振分光片的透光轴平行。
根据本发明的一个方面,所述第一相位延迟单元和第二相位延迟单元同为正相位延迟单元或同为负相位延迟单元,并且满足以下关系:
α
1=α
2=45°或135°,
α
1为逆着所述光路方向观察、所述偏光片的透光轴逆时针旋转到第一相位延迟单元的光轴所述所转过的角度,α
2为逆着所述光路方向观察、所述偏振分光片的透光轴逆时针旋转到第二相位延迟单元的光轴所述所转过的角度。
根据本发明的一个方面,所述第一相位延迟单元和第二相位延迟单元为类型相反的正相位延迟单元或负相位延迟单元,并且满足以下关系:
α
1=-α
2=45°或135°,
α
1为逆着所述光路方向观察、所述偏光片的透光轴逆时针旋转到第一相位延迟单元的光轴所述所转过的角度,α
2为逆着所述光路方向观察、所述偏振分光片的透光轴逆时针旋转到第二相位延迟单元的光轴所述所转过的角度。
根据本发明的一个方面,所述第二相位补偿单元配置成使得:根据初次入射到第二相位补偿单元上的各入射角的光束的偏振态分布,对其进行调制,使得初次入射到第二相位补偿单元上的各入射角的光束透过所述第二相位补偿单元后的偏振态符合被所述偏振分光器反射的条件。
根据本发明的一个方面,所述光学模组还包括位于所述第一相位延迟单元和所述偏光片之间的第一相位补偿单元,其中所述第一相位补偿单元的光轴位于与所述偏光片的透光轴正交的平面内、或与所述偏光片的吸光轴正交的平面内。
根据本发明的一个方面,所述第一相位补偿单元配置成使得:根据从所述偏光片入射到其上的线偏光的偏振态分布对其进行调制,使得初次入射到所述偏振分光器上的光束的偏振态符合被所述偏振分光器反射的条件。
根据本发明的一个方面,所述光学模组还包括透镜,所述透镜与所述半透半反层相邻设置。
根据本发明的一个方面,所述半透半反层贴附在所述透镜的表面上。
本发明还涉及一种近眼显示装置,包括:
显示屏;和
如上所述的光学模组,设置在所述显示屏的光路下游。
本发明还涉及一种光投射方法,包括:
S101:通过半透半反层接收圆偏光或椭圆偏光,并允许所述圆偏光或椭圆偏光至少部分透射;
S102:通过第二相位延迟单元接收所述透射的圆偏光或椭圆偏光并调制后出射;
S103:通过位于所述第二相位延迟单元的光路下游的第二相位补偿单元从对来自所述第二相位延迟单元的光束进行调制并出射;
S104:通过偏振分光片从所述第二相位补偿单元接收光束,所述偏振分光片设置在所述第二相位补偿单元的光路下游,所述偏振分光片具有透光轴,允许偏振方向与所述偏振分光片的透光轴平行的部分光束透射,并将其余部分光束反射回所述第二相位延迟片,
其中所述第二相位补偿单元的光轴位于与所述偏振分光片的透光轴正交的平面内、或与所述偏振分光片的反光轴正交的平面内。
根据本发明的一个方面,所述第二相位补偿单元配置成使得:根据初次入射到第二相位补偿单元上的各入射角的光束的偏振态分布,对其进行调制,使得初次入射到第二相位补偿单元上的各入射角的光束透过所述第二相位补偿单元后的偏振态符合被所述偏振分光器反射的条件。
根据本发明的一个方面,所述光投射方法,还包括:
通过偏光片产生线偏光;
通过第一相位延迟单元从所述偏光片接收线偏光,转换为圆偏光或椭圆偏光并保护射到所述半透半反层上。
根据本发明的一个方面,所述光投射方法还包括,
通过位于所述第一相位延迟单元和所述偏光片之间的第一相位补偿单元对来自所述偏光片的线偏光进行调制后使其入射到所述第一相位延迟单元,其中所述第一相位补偿单元的光轴位于与所述偏光片的透光轴正交的平面内、或与所述偏光片的吸光轴垂直的平面内,其中所述第一相位补偿单元配置成使得:根据从所述偏光片入射到其上的线偏光的偏振态分布对其进行调制,使得初次入射到所述偏振分光器上的光束的偏振态符合被所述偏振分光器反射的条件。
根据本发明的一个方面,所述第一相位延迟单元和第二相位延迟单元同为正相位延迟单元或同为负相位延迟单元,并且满足以下关系:α
1=α
2=45°或135°;或者所述第一相位延迟单元和第二相位延迟单元为类型相反的正相位延迟单元或负相位延迟单元,并且满足以下关系:α
1=-α
2=45°或135°,
其中α
1为逆着所述光路方向观察、所述偏光片的透光轴逆时针旋转到第一相位延迟单元的光轴所述所转过的角度,α
2为逆着所述光路方向观察、所述偏振分光片的透光轴逆时针旋转到第二相位延迟单元的光轴所述所转过的角度。
根据本发明的一个方面,所述光投射方法通过如上所述的光学模组实施。
通过本发明实施例的光学模组,能够减少折叠光路中漏光的发生,尤其是一些优选实施例能够在大角度范围内减少或者消除折叠光路中的漏光,有助于提高用户的感受效果。
附图用来提供对本发明的进一步理解,并且构成说明书的一部分,与本发明的实施例一起用于解释本发明,并不构成对本发明的限制。在附图中:
图1示出了基于折叠光路的光学模组的示意图;
图2示出了根据本发明第一方面一个实施方式的光学模组的示意图;
图3示出了根据本发明另一个实施方式的光学模组的示意图;
图4A、图4B、图4C和图4D分别示出了根据本发明实施例的光学模组的光学参数的示意图;
图5示出了根据本发明实施例1的光学模组的示意图;
图6A、6B分别示出了根据本发明实施例1的光学模组的特定角度入射的光束的偏振状态变化;
图6C和6D分别示出了根据本发明实施例1的光学模组的信号光、杂散光的强度随光线不同入射角度的分布;
图7示出了根据本发明实施例2的光学模组的示意图;
图8A示出了根据本发明实施例2的光学模组的光束的偏振状态;
图8B示出了根据本发明实施例2的光学模组的信号光、杂散光的强度随光线不同入射角度的分布;
图9示出了根据本发明实施例3的光学模组的示意图;
图10A示出了根据本发明实施例3的光学模组的光束的偏振状态;
图10B示出了根据本发明实施例3的光学模组的信号光、杂散光的强度随光线不同入射角度的分布;
图11示出了根据本发明一个实施例的光投射方法;
图12示出了根据本发明的第二方面第一实施例的光学模组;
图13示出了根据本发明第二方面第一实施例的光学模组的光路示意图;
图14A示出了在缺少相位补偿单元的情况下的漏光情况,图14B示出了根据本发明的第二方面在添加相位补偿单元的情况下的漏光情况;;
图15示出了根据发明第二方面的第二实施例的光学模组;
图16示出了根据本发明第二方面的第三实施例的光学模组;和
图17示出了根据本发明第二方面的第四实施例的光学模组。
在下文中,仅简单地描述了某些示例性实施例。正如本领域技术人员可认识到的那样,在不脱离本发明的精神或范围的情况下,可通过各种不同方式修改所描述的实施例。因此,附图和描述被认为本质上是示例性的而非限制性的。
在本发明的描述中,需要理解的是,术语"中心"、"纵向"、"横向"、"长度"、"宽度"、"厚度"、"上"、"下"、"前"、"后"、"左"、"右"、"竖直"、"水平"、"顶"、"底"、"内"、"外"、"顺时针"、"逆时针"等指示的方位或位置关系为基于附图所示的方位或位置关系,仅是为了便于描述本发明和简化描述,而不是指示或暗示所指的装置或元件必须具有特定的方位、以特定的方位构造和操作,因此不能理解为对本发明的限制。此外,术语"第一"、"第二"仅用于描述目的,而不能理解为指示或暗示相对重要性或者隐含指明所指示的技术特征的数量。由此,限定有"第一"、"第二"的特征可以明示或者隐含地包括一个或者更多个所述特征。在本发明的描述中,"多个"的含义是两个或两个以上,除非另有明确具体的限定。
在本发明的描述中,需要说明的是,除非另有明确的规定和限定,术语"安装"、"相连"、"连接"应做广义理解,例如,可以是固定连接,也可以是可拆卸连接,或一体地连接:可以是机械连接,也可以是电连接或可以相互通讯;可以是直接相连,也可以通过中间媒介间接相连,可以是两个元件内部的连通或两个元件的相互作用关系。对于本领域的普通技术人员而言,可以根据具体情况理解上述术语在本发明中的具体含义。
在本发明的描述中,需要说明的是,。除非另有明确规定和限定,属于“片”,“膜”应做广义理解,例如,可以是独立光学元件,也可以是贴敷在透镜或透明基片上的带膜层。
在本发明中,除非另有明确的规定和限定,第一特征在第二特征之"上"或之"下"可以包括第一和第二特征直接接触,也可以包括第一和第二特征不是直接接触而是通过它们之间的另外的特征接触。而且,第一特征在第二特征"之上"、"上方"和"上面"包括第一特征在第二特征正上方和斜上方,或仅仅表示第一特征水平高度高于第二特征。第一特征在第二特征"之下"、"下方"和"下面"包括第一特征在第二特征正上方和斜上方,或仅仅表示第一特征水平高度小于第二特征。
下文的公开提供了许多不同的实施方式或例子用来实现本发明的不同结构。为了简化本发明的公开,下文中对特定例子的部件和设置进行描述。当然,它们仅仅为示例,并且目的不在于限制本发明。此外,本发明可以在不同例子中重复参考数字和/或参考字母,这种重复是为了简化和清楚的目的,其本身不指示所讨论各种实施方式和/或设置之间的关系。此外,本发明提供了的各种特定的工艺和材料的例子,但是本领域普通技术人员可以意识到其他工艺的应用和/或其他材料的使用。
以下结合附图对本发明的实施例进行说明,应当理解,此处所描述的实施例仅用于说明和解释本发明,并不用于限定本发明。
第一方面
图1示出了基于折叠光路的光学模组,图中右侧为物侧,例如放置显示屏,图中 左侧为像侧(观察侧),即用户的眼球所在的位置。如图1所示的光学模组中,沿着光路的方向(从物侧到像侧)依次包括四分之一波片11、半透半反层13(图1中贴附在透镜12上)、四分之一波片14、偏振分光片15。理论上,来自物侧的光束E1(线偏光)依次经过四分之一波片11、透镜12和半透半反层13、四分之一波片14后入射到偏振分光片15上,首次入射到偏振分光片15上的光束E3为线偏光,偏振方向与偏振分光片15的透光轴垂直,因而理论上应当被偏振分光片15反射,然后透射通过四分之一波片14后被半透半反层13反射,再次经过四分之一波片14并再次入射到偏振分光片15上,此时偏振光E6的偏振方向与偏振分光片15的透光轴平行,因此可透射通过偏振分光片15,如图1中的“信号”所示。但在实际的折叠光路中,首次入射到偏振分光片15上的光束,部分光束将透射通过偏振分光片15,形成图1所示的“噪声”,即产生漏光现象。尤其是当入射光束与光学组件的光轴OO(图1中水平方向)所成的入射角较大时,这种漏光现象更为严重,漏光的强度(噪声的强度)甚至可达到轴向信号光强度的38%,严重干扰用户的观看体验。
本申请的发明人发现,针对上述问题,可以通过在光路中设置一个或多个相位补偿单元来解决。并且进一步优选的,可以通过结合光学模组中的一些元件的参数设置来进一步改善。下面详细说明。
图2示出了根据本发明的一个实施例的光学模组20,下面参考图2详细描述。如图2所示,光学模组20沿着光路方向(从物侧到像侧,图中从右向左)包括偏光片Pol、第一相位延迟单元QWP1、半透半反层BS、第二相位延迟单元QWP2、以及偏振分光片PBS,并且还包括第二相位补偿单元RB,第二相位补偿单元RB位于所述第二相位延迟单元QWP2与所述偏振分光片PBS之间。
其中所述偏光片Pol配置成可接收入射光束,并将其调制成线偏光E1,第一相位延迟单元QWP1配置成可从偏光片Pol接收所述线偏光E1,并将其调制为圆偏光或椭圆偏光E2。半透半反层BS位于所述第一相位延迟单元QWP1的光路下游,并接收所述圆偏光或椭圆偏光E2,并使其部分透射,部分反射。第二相位延迟单元QWP2位于所述半透半反层BS的光路下游,第二相位补偿单元RB位于第二相位延迟单元QWP2的光路下游,偏振分光片PBS设置在所述第二相位补偿单元RB的光路下游,所述偏振分光片PBS具有透光轴。
如图2所示的光学模组20的工作过程如下。偏光片Pol接收入射的光束并出射线偏光E1,线偏光E1经过第一相位延迟单元QWP1被调制为圆偏光或椭圆偏光E2,圆偏光或椭圆偏光E2入射到半透半反层BS。半透半反层BS位于所述第一相位延迟单元QWP1的光路下游,并接收所述圆偏光或椭圆偏光E2,允许所述圆偏光或者椭圆偏光至少部分透射,本发明不限制所述半透半反层BS的具体的透射率,可以为50%或其他比例。部分透射的光束经过第二相位延迟单元QWP2被调制为线偏光E3,线偏光E3入射到第二相位补偿单元RB上并且被调制为线偏光E3’,线偏光E3’的偏振方向与偏振分光片PBS的透光轴垂直,因而被偏振分光片PBS反射并发生折返,然后折返光束透射通过第二相位补偿单元RB和第二相位延迟单元QWP2后(圆偏光或椭圆偏光E4)被半透半反层BS反射(圆偏光或椭圆偏光E5),再次经过第二相位延迟单元QWP2(线偏光E6) 和第二相位补偿单元RB(线偏光E6’)并再次入射到偏振分光片PBS上。偏振分光片PBS设置在所述第二相位延迟单元QWP2的光路下游,所述偏振分光片具有透光轴TPBS,允许偏振方向与透光轴TPBS平行的部分光束透射,并将其余部分光束反射回所述第二相位延迟单元QWP2。此时偏振光E6’的偏振方向与偏振分光片PBS的透光轴平行,因此可透射通过偏振分光片PBS。也就是被所述偏振分光片PBS反射的光束透射通过所述第二相位补偿单元RB和第二相位延迟单元QWP2,被所述半透半反层BS部分反射,再次透射通过所述第二相位延迟单元QWP2和第二相位补偿单元RB,到达所述偏振分光片PBS的折返光束的偏振方向与所述偏振分光片PBS的透光轴平行,从而能够透射,形成信号(光)。
在图2的实施例中,通过在第二相位延迟单元QWP2和所述偏振分光片PBS之间增设第二相位补偿单元RB,使得初次入射到所述偏振分光片PBS上的各入射角的光束E3’的偏振态符合或者尽量符合被所述偏振分光片PBS反射的条件,极大地减小了漏光和杂散光的强度,杂散光的强度可被减小到信号光强度的5%,同时基本不会影响信号光。图2中用于表明光束的箭头上面的圆点或者箭头,代表了该光束对应的偏振态。另外,图2的光学模组20的结构中,也可以不包括偏光片Pol和第一相位延迟单元QWP1。偏光片Pol和第一相位延迟单元QWP1可以集成到光学模组20的上游的光源(例如屏幕)中。同时,入射到第一相位延迟单元QWP1上的光束可以为线偏光,也可以为带有一定圆偏分量的线偏光。
相比于图1的光学结构,图2的光学模组20中包括位于所述第二相位延迟单元QWP2和所述偏振分光片PBS之间的第二相位补偿单元RB。根据本发明的一个优选实施例,其中所述第二相位补偿单元RB的光轴位于与所述偏振分光片PBS的透光轴TPBS正交的平面内、或与所述偏振分光片PBS的反光轴正交的平面内。根据本发明的一个实施例,所述第二相位补偿单元RB配置成使得:根据初次入射到第二相位补偿单元RB上的各入射角的光束的偏振态分布,对其进行调制,使得初次入射到第二相位补偿单元RB上的各入射角的光束透过所述第二相位补偿单元RB后的偏振态符合被所述偏振分光器PBS反射的条件。本领域技术人员容易理解,本发明中,第二相位补偿单元RB使得初次入射到所述偏振分光片PBS上的各入射角的光束的偏振态符合被所述偏振分光片反射的条件,并非必然使得初次入射到偏振分光片上的光束的偏振态完全符合被反射的条件,只要使得更大比例的光束的偏振态符合被反射的条件即可(与不设置相位补偿单元的情形相比较)。
另外,本发明的上下文中,“正交”或“垂直”,包括相互之间成90度的情形,但不严格限制于此,例如在90°±5°的范围内,都可以认为是“正交”或“垂直”。
根据本发明的一个优选实施例,所述第一相位延迟单元QWP1配置成可令入射到其上的线偏光沿光轴方向的偏振分量产生n*λ+3/4λ的相位延迟、或n*λ+1/4λ的相位延迟;第二相位延迟单元QWP2配置成可令入射到其上的线偏光沿光轴方向的偏振分量产生n*λ+3/4λ的相位延迟、或n*λ+1/4λ的相位延迟,其中n为整数。根据本发明的一个优选实施例,所述第一相位延迟单元QWP1和第二相位延迟单元QWP2均为四分之一波片。
另外优选的,除了在所述第二相位延迟单元QWP2和所述偏振分光片PBS之间设置第二相位补偿单元RB之外,还可以在第一相位延迟单元QWP1的光路上游设置第一相位补偿单元RA。图3示出了根据这样一个实施例的光学模组30,其中第一相位补偿单元RA位于所述第一相位延迟单元QWP1与偏光片Pol之间。图3中还示出了xyz坐标系,其中垂直纸面向里为正x方向,竖直向下为正y方向,水平向左(从物侧到像侧)为正z方向(即沿着光路的方向)。下面参考附图详细描述。
其中所述第一相位补偿单元RA的光轴位于与所述偏光片Pol的透光轴TPol正交的平面内、或与所述偏光片Pol的吸光轴正交的平面内。在设置有第一相位补偿单元RA的情况下,来自偏光片Pol的线偏光E1经过第一相位补偿单元RA后,出射带有一定圆偏分量的线偏光,然后经过第一相位延迟单元QWP1被调制为圆偏光或椭圆偏光E2。根据本发明的一个实施例,所述第一相位补偿单元RA配置成使得:根据从所述偏光片Pol沿各个方向入射到其上的线偏光的偏振态分布对其进行调制,使得初次入射到所述偏振分光片上的各入射角的光束的偏振态符合被所述偏振分光片反射的条件。本领域技术人员容易理解,本发明中,第一相位补偿单元RA使得初次入射到所述偏振分光片PBS上的各入射角的光束的偏振态符合被所述偏振分光片反射的条件,并非必然使得初次入射到偏振分光片上的光束的偏振态完全符合被反射的条件,只要使得更大比例的光束的偏振态符合被反射的条件即可(与不设置相位补偿单元的情形相比较)。
因此,在图3的实施例中,第一相位补偿单元RA和第二相位补偿单元RB共同对光束的相位进行补偿,其中所述第一相位补偿单元RA配置成根据从所述偏光片Pol沿各个方向入射到其上的线偏光的偏振态分布对其进行调制,所述第二相位补偿单元RB配置成根据初次入射到第二相位补偿单元RB上的各入射角的光束的偏振态分布对其进行调制,使得初次入射到所述偏振分光片PBS上的光束的偏振态符合被所述偏振分光片PBS反射的条件。
在图2和图3的实施例中,光学模组20和30均包括偏光片Pol,本发明不限于此,光学模组20和30也可不包括偏光片Pol,偏光片Pol例如可以与光路上游的光源(例如屏幕)集成在一起,这些都在本发明的保护范围内。
本领域技术人员容易理解,第一相位补偿单元RA、第二相位补偿单元RB的相位补偿量不限于具体的数值,只要能够有助于提高光束初次入射到偏振分光片PBS时被反射的比例即可。另外,第一相位补偿单元RA和第二相位补偿单元可以均由单个相位补偿片构成,也可以包括多个相位补偿片,本发明不限制其具体数量。在进行具体的光路设计时,在给定了波长、偏光片Pol、第一相位延迟单元QWP1、第二相位延迟单元QWP2、PBS的光学参数和器件方位参数之后,可进行第一相位补偿单元RA、第二相位补偿单元RB的设计,只要相比于未增加第一相位补偿单元RA、第二相位补偿单元RB时能够提高光束初次入射到偏振分光片PBS时被反射的比例即可。具体计算方法此处不再赘述。
根据本发明的一个实施例,所述光学模组还包括透镜,所述透镜与所述半透半反层BS相邻设置,半透半反层BS例如可以贴附在所述透镜的表面上。
进一步优选的,通过设定第一相位延迟单元的类型和光轴角度关系,可以进一步 消除或者减少漏光。本发明中为了清楚描述,需要区分第一相位延迟单元QWP1和第二相位延迟单元QWP2的“正”和“负”的类型。“正”和“负”定义如下:
正相位延迟单元:令入射光束沿光轴方向的偏振分量产生N*λ+1/4λ的相位延迟,其中N为整数;
负相位延迟单元:令入射光束沿光轴方向的偏振分量产生M*λ+3/4λ的相位延迟,其中M为整数。
根据本发明的实施例,当满足以下关系时,图1所示的漏光现象可以被进一步减轻:第一相位延迟单元QWP1和第二相位延迟单元QWP2同为正相位延迟单元或同为负相位延迟单元,并且满足以下关系:α
1=α
2=45°或135°;或者所述第一相位延迟单元和第二相位延迟单元为类型相反的正相位延迟单元或负相位延迟单元,并且满足以下关系:α
1=-α
2=45°或135°,
其中α
1为逆着所述光路方向观察(即在图2或图3中从左向右观察)、入射到所述第一相位延迟单元QWP1上的线偏光正入射时的偏振方向D1逆时针旋转到第一相位延迟单元QWP1的光轴TQWP1所转过的角度,α
2为逆着所述光路方向观察、所述偏振分光片的透光轴TPBS逆时针旋转到第二相位延迟单元QWP2的光轴TQWP2所转过的角度。上面描述了角度α
1和α
2的关系,本领域技术人员容易理解,上述等式容许在工程可接受范围内的误差,例如当二者与目标角度之间的差异在正负5度的范围内时,均可认为满足上述等式。以目标角度α
1=α
2=45°为例,当实际中α
1=40°、α
2=50°时,可认为满足α
1=α
2=45°。
当光学模组包括偏光片时,偏光片Pol的透光轴与入射到所述第一相位延迟单元QWP1上的线偏光正入射时的偏振方向D1是平行的,因此α
1即为逆着所述光路方向观察(即在图2中从左向右观察)、所述偏光片的透光轴逆时针旋转到第一相位延迟单元QWP1的光轴TQWP1所转过的角度。
图4A示出了α
1为45度的情形,图4B示出了α
1为135度的情形,图4C示出了α
2为45度的情形,图4D示出了α
2为135度的情形。当入射到第一相位延迟单元QWP1上的光束为线偏光时,该偏振方向D1即为该线偏光的偏振方向。或者当第一相位延迟单元QWP1的上游设置有偏光片时,该偏振方向即对应于偏光片的透光轴。
在上述实施例中,通过增加第一相位补偿单元RA、第二相位补偿单元RB、设置第一相位延迟单元QWP1和第二相位延迟单元QWP2的类型以及光轴角度关系,能够使得初次入射到所述偏振分光片PBS上的各入射角的光束的偏振态符合或者尽可能符合被所述偏振分光片PBS反射的条件,即偏振方向垂直于或者尽可能垂直于所述偏振分光片PBS的透光轴TPBS,或平行于或者尽可能平行于所述偏振分光片PBS的反光轴。
另外,本发明中为了清楚起见,将区分初次(首次)入射到偏振分光片的光束以及二次入射到偏振分光片的光束。参考图2,光束E1经过第一相位补偿单元RA、第一相位延迟单元QWP1、半透半反层BS、第二相位延迟单元QWP2后被调制为光束E3’并 入射到偏振分光片PBS上,光束E3’称为初次(首次)入射到偏振分光片PBS上的光束,光束E3称为初次(首次)入射到第二相位补偿单元RB上的光束;光束E6’称为二次入射到偏振分光片上的光束,光束E6称为二次入射到第二相位补偿单元RB上的光束,光束E4、E5、E6和E6’均可称为折返光束。对于其余附图中的光路结构也可做相同的理解,此处不再赘述。
相比于现有技术的折叠光路的方案,通过本发明的技术方案,能够使得初次入射到所述偏振分光片PBS上的光束透射通过偏振分光片PBS的比例更小,因此产生的噪声(杂散光)更小。绝大部分光束被反射并形成折返光束,二次入射到偏振分光片PBS上时,其偏振方向与所述偏振分光片PBS的透光轴TPBS平行或尽可能平行,因而能够透射并形成信号(光)。
另外,本发明中,第一相位补偿单元RA和第二相位补偿单元RB是沿着光学模组的光路方向来命名的,并不代表必然具有第一相位补偿单元RA,例如在图2的实施例中并不包括第一相位补偿单元RA。
发明人通过如下具体实施例测试了本发明的效果。
实施例1
实施例1的光路结构如图5所示,其中在吸收式偏振片Pol的光路上游具有发光的屏幕。实施例1的光路结构的具体参数如下:
吸收性偏振片Pol的透光轴平行于x轴;第一相位延迟单元QWP1为正相位延迟单元,它由n
o<n
e且光轴满足α
1=45°的四分之一波片构成;半透半反层BS的透射率为50%,反射率为50%;第二相位延迟单元QWP2为正相位延迟单元,它由n
o<n
e且光轴满足α
2=α
1=45°的四分之一波片构成;偏振分光片PBS的透光轴平行于y轴。
信号光、杂散光的强度随光线不同入射角度分布如图6C、图6D所示。由图可知,光线在θ小于30o时,信号光的强度远大于杂散光强度,该区域漏光现象并不明显。
图6A表示在实施例1中,以θ=60°,
入射的入射光线在依次首次通过吸收型偏振片Pol、第一相位延迟单元QWP1、第二相位延迟单元QWP2、偏振分光片PBS后的偏振状态,分别用绿点M、品红点N、红点O、黑色点P表示;在光以θ=60°,
入射时:由第一相位延迟单元QWP1的快轴和慢轴组成的旋转轴为品红色直线F
OS
O,由QWP2的快轴和慢轴组成的旋转轴为红色直线F
NS
N,如图6A所示;当光以θ=60°,
入射时,它首次经过第一相位延迟单元QWP1和首次经过第二相位延迟单元QWP2后偏振被调制的过程在Poincare球上表示为:QWP1调制过程——将M点绕着品红色直线F
NS
N顺时针旋转90°到点N;QWP2调制过程——将N点绕着红色直线F
OS
O顺时针旋转90°到点O。(顺时针旋转指对于直线FS从F端向S端看去时顺时针旋转)
当光以θ=60°,
入射时,符合被偏振分光片PBS反射的偏振态在Pioncare球 上为黑点P关于球心对称的点(此时与绿点M重合),而由图6A可以看到以θ=60°,
入射的光在依次首次经过吸收型偏振片Pol、第一相位延迟单元QWP1、第二相位延迟单元QWP2后偏振态(红点O)与绿点M并不重合,且两点处半径构成的夹角较大,因此首先到达偏振分光片PBS的光不会被全部吸收,会产生一定程度的漏光。
图6B表示在实施例1中,以θ=60°,
入射的入射光线在依次首次通过吸收型偏振片Pol、第一相位延迟单元QWP1、第二相位延迟单元QWP2、偏振分光片PBS后的偏振状态,分别用绿点M、品红点N、红点O、黑色点P表示。光以θ=60°,
入射时,符合被PBS反射偏振态在Pioncare球上为黑点P关于球心对称的点,而由图6B可以看到以θ=60°,
入射的光在依次首次经过偏光片、第一相位延迟单元QWP1、第二相位延迟单元QWP2后偏振态与P点关于球心的对称点并不重合,且两点处半径构成的夹角很大,因此首次到达偏振分光片PBS的光会有一部分直接通过偏振分光片PBS,而不是被完全反射,会有一定程度的漏光产生。
实施例2
图7示出了实施例2的光路结构。相比于实施例1,实施例2的光路结构中具有如下区别:添加第二相位补偿单元RB。
第二相位延迟单元QWP2为负相位延迟单元,它由n
o>n
e且光轴满足α
2=-α
1=-45°(即135o)的四分之一波片构成。第一相位延迟单元QWP1为正相位延迟单元。
第二相位补偿单元RB可以有多种构型。本实施例中选定的第二相位补偿单元RB的参数如下表所示,其包括沿着光路方向叠加的相位延迟片B1和相位延迟片B2。其中相位延迟片B1的参数如下:n
o<n
e,光轴方向平行于x轴、相位延迟量为133nm。相位延迟片B2的参数如下:n
o<n
e,光轴方向平行于z轴、相位延迟量为104nm。
相位延迟片B1 | 相位延迟片B2 | |
光轴方向 | 与x轴平行 | 与z轴平行 |
Retardance(相位延迟量) | 133nm | 104nm |
类型 | n o<n e | n o<n e |
以θ=60,
入射的光线在实施例2结构中的偏振态变化如图8A所示,可以看到光第一次经过第二相位补偿单元的偏振态点V与P点关于球心的对称点几乎重合,因此该光线在第一次进入偏振分光片PBS时几乎全被反射,不产生漏光。
杂散光的强度随光线不同入射角度分布如图8B所示。与6D相比,本实施例极大 降低折叠光路中的漏光,漏光强度减小到原来的10%。
实施例3
图9示出了实施例3的光路结构。相比于实施例1,实施例3的光路结构中具有如下区别:添加第一相位补偿单元RA和第二相位补偿单元RB。
第二相位延迟单元QWP2为负相位延迟单元,它由n
o>n
e且光轴满足α
2=-α
1=-45°的四分之一波片构成。第一相位延迟单元QWP1为正相位补偿单元。
第一相位补偿单元RA可以有多种构型。本实施例中选定的第一相位补偿单元RA的参数如下:其包括沿着光路方向叠加的相位延迟片A1和相位延迟片A2。其中相位延迟片A1的参数如下:n
o<n
e,光轴方向平行于x轴、相位延迟量为206nm。相位延迟片A2的参数如下:n
o<n
e,光轴方向平行于y轴、相位延迟量为85nm。
相位延迟片A1 | 相位延迟片A2 | |
光轴方向 | 与x轴平行 | 与y轴平行 |
Retardance(相位延迟量) | 206nm | 85nm |
类型 | n o<n e | n o>n e |
第二相位补偿单元RB可以有多种构型。本实施中选定的第二相位补偿单元RB的参数如下:其包括沿着光路方向叠加的相位延迟片B1和相位延迟片B2。其中相位延迟片B1的参数如下:n
o>n
e,光轴方向平行于x轴、相位延迟量为85nm。相位延迟片B2的参数如下:n
o>n
e,光轴方向平行于y轴、相位延迟量为206nm。
相位延迟片B1 | 相位延迟片B2 | |
光轴方向 | 与x轴平行 | 与y轴平行 |
Retardance(相位延迟量) | 85nm | 206nm |
类型 | n o>n e | n o>n e |
以θ=60,
入射的光线在实施例3结构中的偏振态变化如图10A所示,可以看到光第一次经过第二相位补偿单元的偏振态点V与P点关于球心的对称点几乎重合,因此该光线在第一次进入偏振分光片PBS时几乎全被反射,不产生漏光。
杂散光的强度随光线不同入射角度分布如图10B所示。与图6D相比,本实施例极大降低折叠光路中的漏光,漏光强度减小到原来的7%。
通过上述实施例1-3可以看出,根据本发明实施例的光学模组,能够减少折叠光 路中漏光的发生。
本发明还涉及一种近眼显示装置,包括:显示屏;和如上所述的光学模组20、30或40,光学模组20、30或40设置在所述显示屏的光路下游。所述近眼显示装置诸如增强现实AR装置、虚拟现实VR装置或其他类型的混合现实MR装置。
图11示出了根据本发明一个实施例的光投射方法100,下面参考图16详细描述。
在步骤S101:通过半透半反层接收圆偏光或椭圆偏光,并允许所述圆偏光或椭圆偏光至少部分透射;
在步骤S102:通过第二相位延迟单元接收所述透射的圆偏光或椭圆偏光并调制后出射;
在步骤S103:通过位于所述第二相位延迟单元的光路下游的第二相位补偿单元从对来自所述第二相位延迟单元的光束进行调制并出射;
在步骤S104:通过偏振分光片从所述第二相位补偿单元接收光束,所述偏振分光片设置在所述第二相位补偿单元的光路下游,所述偏振分光片具有透光轴,允许偏振方向与所述偏振分光片的透光轴平行的部分光束透射,并将其余部分光束反射回所述第二相位延迟片,
其中所述第二相位补偿单元的光轴位于与所述偏振分光片的透光轴正交的平面内、或与所述偏振分光片的反光轴正交的平面内。
根据本发明的一个优选实施例,所述第二相位补偿单元配置成使得:根据初次入射到第二相位补偿单元上的各入射角的光束的偏振态分布,对其进行调制,使得初次入射到第二相位补偿单元上的各入射角的光束透过所述第二相位补偿单元后的偏振态符合被所述偏振分光器反射的条件。
根据本发明的一个优选实施例,所述光投射方法还包括:
通过偏光片产生线偏光;
通过第一相位延迟单元从所述偏光片接收线偏光,转换为圆偏光或椭圆偏光并保护射到所述半透半反层上。
根据本发明的一个优选实施例,所述光投射方法,还包括,
通过位于所述第一相位延迟单元和所述偏光片之间的第一相位补偿单元对来自所述偏光片的线偏光进行调制后使其入射到所述第一相位延迟单元,其中所述第一相位补偿单元的光轴位于与所述偏光片的透光轴正交的平面内、或与所述偏光片的吸光轴垂直的平面内,其中所述第一相位补偿单元配置成使得:根据从所述偏光片入射到其上的线偏光的偏振态分布对其进行调制,使得初次入射到所述偏振分光器上的光束的偏振态符合被所述偏振分光器反射的条件。
根据本发明的一个优选实施例,所述第一相位延迟单元和第二相位延迟单元同为正相位延迟单元或同为负相位延迟单元,并且满足以下关系:α
1=α
2=45°或135°;或者所述第一相位延迟单元和第二相位延迟单元为类型相反的正相位延迟单元或负相位延迟单元,并且满足以下关系:α
1=-α
2=45°或135°,
其中α
1为逆着所述光路方向观察、所述偏光片的透光轴逆时针旋转到第一相位延 迟单元的光轴所述所转过的角度,α
2为逆着所述光路方向观察、所述偏振分光片的透光轴逆时针旋转到第二相位延迟单元的光轴所述所转过的角度。
根据本发明的一个优选实施例,所述光投射方法通过如上所述的光学模组20或30实施。
第二方面
上面描述的本发明第一方面的实施例中,光学模组10包括透镜(第一透镜单元),光学模组也可包括多个透镜单元,下面参考附图详细描述。
图12示出了根据本发明的一个实施例的光学模组40,下面参考图12详细描述。如图12所示,光学模组40沿着光路方向从光路上游到光路下游(从物侧到像侧,图中从右向左)包括第一透镜单元LENS1、半透半反层BS、第二透镜单元LENS2、第二相位延迟单元QWP2、第二相位补偿单元RB以及偏振分光片PBS。图12中,在光学模组40的光路上游设置有显示屏11,显示屏11发射出的光线入射到光学模组40上,在光学模组40的内部发生折叠并最终出射,进入到人眼中成像。所述显示屏11发射出的光优选为圆偏光或者椭圆偏光。光学模组40的具体工作方式将在下文详细描述。
如图12所示,所述半透半反层BS位于第一透镜单元LENS1的光路下游,贴附在第一透镜单元LENS1的表面上,本领域技术人员理解,本发明不限于此,所述半透半反层BS也可以位于第一透镜单元LENS1的光路上游,或者也可以与第一透镜单元LENS1具有一定的间隔,这些都在本发明的范围内。
另外,在图12的实施例中,第二相位延迟单元QWP2、第二相位补偿单元RB以及偏振分光片PBS依次堆叠在第二透镜单元LENS2的表面上,这些光学部件彼此之间也可以间隔开,此处不再赘述。
本发明中,所述第一透镜单元LENS1和第二透镜单元LENS2配置成可将入射到所述第一透镜单元LENS1上的图像光成像到所述第二透镜单元LENS2的下游的用户眼中。第一透镜单元LENS1和第二透镜单元LENS2可将显示屏11的内容成像到人眼中,另外优选的,第一透镜单元LENS1可对光学模组的屈光度进行调节。第一透镜单元LENS1和第二透镜单元LENS2可以由单透镜构成,也可以包括透镜组,这些都在本发明的范围内。
图13示出了图12的光学模组40的工作过程,下面参考图13详细描述。
如图13所示,显示屏11发射出圆偏光或椭圆偏光E2,圆偏光或椭圆偏光E2经过第一透镜单元LENS1并入射到半透半反层BS。半透半反层BS位于所述第一透镜单元LENS1的光路下游,并接收所述圆偏光或椭圆偏光E2,允许所述圆偏光或者椭圆偏光E2至少部分透射,本发明不限制所述半透半反层BS的具体的透射率,可以为50%或其他比例。部分透射的光束E2然后通过第二透镜单元LENS2并入射到第二相位延迟单元QWP2上。本领域技术人员容易理解,第一透镜单元LENS1、半透半反层BS和第二透镜单元LENS2不改变光束的偏振状态,因此第一透镜单元LENS1、半透半反层BS和第二透镜单元LENS2的光路上游和光路下游的光束均以E2来表示。
光束E2经过第二相位延迟单元QWP2后被调制为线偏光E3,线偏光E3入射到第二 相位补偿单元RB上并且被调制为线偏光E3’,线偏光E3’的偏振方向与偏振分光片PBS的透光轴垂直,因而被偏振分光片PBS反射并发生折返,然后折返光束透射通过第二相位补偿单元RB和第二相位延迟单元QWP2后(圆偏光或椭圆偏光E4,与显示屏11发出的光线E2的偏振不同,其中一个是右旋圆(椭圆)偏振光,另一个是左旋圆(椭圆)偏振光),通过第二透镜单元LENS2后被半透半反层BS部分反射(圆偏光或椭圆偏光E5),再次经过第二相位延迟单元QWP2(线偏光E6)和第二相位补偿单元RB(线偏光E6’)并再次入射到偏振分光片PBS上。偏振分光片PBS设置在所述第二相位延迟单元QWP2的光路下游,所述偏振分光片PBS具有透光轴TPBS,允许偏振方向与透光轴TPBS平行的部分光束透射,并将其余部分光束反射回所述第二相位延迟单元QWP2。此时偏振光E6’的偏振方向与偏振分光片PBS的透光轴平行,因此可透射通过偏振分光片PBS。
上述光路折返的过程中,被所述偏振分光片PBS反射的光束透射通过所述第二相位补偿单元RB和第二相位延迟单元QWP2,被所述半透半反层BS部分反射,再次透射通过所述第二相位延迟单元QWP2和第二相位补偿单元RB,到达所述偏振分光片PBS的折返光束的偏振方向与所述偏振分光片PBS的透光轴平行,从而能够透射,形成信号(光),在人眼中成像。
在图12和图13的实施例中,通过在第二相位延迟单元QWP2和所述偏振分光片PBS之间增设第二相位补偿单元RB,使得初次入射到所述偏振分光片PBS上的各入射角的光束E3’的偏振态符合或者尽量符合被所述偏振分光片PBS反射的条件,极大地减小了漏光和杂散光的强度,杂散光的强度可被减小到信号光强度的5%,同时基本不会影响信号光。图13中用于表明光束的箭头上面的圆点或者箭头,代表了该光束对应的偏振态。
根据本发明的一个优选实施例,其中所述第二相位补偿单元RB的光轴位于与所述偏振分光片PBS的透光轴TPBS正交的平面内、或与所述偏振分光片PBS的反光轴正交的平面内。根据本发明的一个实施例,所述第二相位补偿单元RB配置成使得:根据初次入射到第二相位补偿单元RB上的各入射角的光束的偏振态分布,对其进行调制,使得初次入射到第二相位补偿单元RB上的各入射角的光束透过所述第二相位补偿单元RB后的偏振态符合被所述偏振分光器16反射的条件。本领域技术人员容易理解,本发明中,第二相位补偿单元RB使得初次入射到所述偏振分光片PBS上的各入射角的光束的偏振态符合被所述偏振分光片PBS反射的条件,并非必然使得初次入射到偏振分光片PBS上的光束的偏振态完全符合被反射的条件,只要使得更大比例的光束的偏振态符合被反射的条件即可(与不设置相位补偿单元的情形相比较)。
另外,本发明的上下文中,λ表示入射光的波长。
下表I给出了本发明第一实施例的光学模组的透镜参数的一种组合(其中光路上游为“前”,光路下游为“后”)。
表I
另外,第二相位补偿单元RB可以具有多种构成方式。根据本发明一个优选实施例,第二相位补偿单元包括沿着光路方向叠加的相位延迟片A和相位延迟片B。其中相位延迟片A的参数如下:no<ne,光轴方向与其平面平行且垂直于偏振分光片PBS的透光轴、相位延迟量为80nm;相位延迟片B的参数如下:no>ne,光轴方向与其平面平行且平行于偏振分光片PBS的透光轴、相位延迟量为80nm。
图14A和图14B示出了漏光情况的对比示意图。根据现有技术,在缺少相位补偿单元的情况下,在大视场内会有严重的漏光(如图14A所示的);而根据本发明图12和图13的第一实施例,通过添加相位补偿单元,漏光可被降低为原来的4.3%(如图14B所示的)。
图15示出了根据本发明第二实施例的光学模组40,下面重点描述与图12实施例的不同之处,相同之处不再赘述。
如图15所示,在图15的光学模组40中,所述半透半反层BS位于第一透镜单元LENS1的光路上游,贴附在第一透镜单元LENS1的光路上游的表面上。另外,第二透镜单元LENS2位于偏振分光片PBS的光路下游,同时在偏振分光片PBS与第二透镜单元LENS2之间还设置有第二偏光片POL2。通过设置第二偏光片POL2,能够进一步减少偏振分光片PBS的漏光。
下表II给出了本发明第二实施例的光学模组的透镜参数的一种组合(其中光路上游为“前”,光路下游为“后”)。
表II
图15实施例的光学模组40的工作方式基本与图13所示的相同,此处不再赘述。
图16示出了根据本发明第三实施例的光学模组40。如图16所示,所述第二透镜单元LENS2包括子透镜LENS2-1和LENS2-2,另外,第二透镜单元LENS2位于第二相位延迟单元QWP2的光路上游,位于半透半反层BS的光路下游。图16中的光学模组40还包括位于偏振分光片PBS的光路下游的第二偏光片POL2。光学模组40还包括位于所述显示屏11和第一透镜单元LENS1之间的第一偏光片POL1和第一相位延迟单元QWP1。第一偏光片POL1接收来自显示屏11的光束并出射线偏光,线偏光经过第一相位延迟单元QWP1被调制为圆偏光或椭圆偏光E2并入射到所述第一透镜单元LENS1上。
下表III给出了本发明第三实施例的光学模组的透镜参数的一种组合(其中光路上游为“前”,光路下游为“后”)。
表III
图17示出了根据本发明第四实施例的光学模组40,其中所述第二透镜单元LENS2包括子透镜LENS2-1和LENS2-2。如图17所示,光学模组40沿着光路方向依次包括半透半反层BS、第一透镜单元LENS1、第二透镜单元LENS2(子透镜LENS2-1和LENS2-2)、第二相位延迟单元QWP2、第二相位补偿单元RB和偏振分光片PBS。
下表IV给出了本发明第四实施例的光学模组的透镜参数的一种组合(其中光路上游为“前”,光路下游为“后”)。
表IV
在上述图12-17的实施例中,显示屏11也可以构成光学模组40的一部分。另外,本发明中,可以灵活设置第二透镜单元LENS2的位置,只要第二透镜单元LENS2位于所述半透半反层BS的光路下游即可。
根据本发明的一个优选实施例,第二相位延迟单元QWP2配置成可令入射到其上的线偏光沿光轴方向的偏振分量产生n*λ+3/4λ的相位延迟、或n*λ+1/4λ的相位延迟,其中n为整数。另外,在包括第一相位延迟单元QWP1的实施例中(例如图16的实施例),第一相位延迟单元QWP1配置成可令入射到其上的线偏光沿光轴方向的偏振分量产生n*λ+3/4λ的相位延迟、或n*λ+1/4λ的相位延迟。根据本发明的一个优选实施例,所述第二相位延迟单元QWP2和第一相位延迟单元QWP1均为四分之一波片。
另外,本发明的变型实施例中,光学模组40也可不包括第一偏光片POL1,第一偏光片POL1例如可以与光路上游的光源(例如显示屏11)集成在一起,这些都在本发明的保护范围内。另外,第一偏光片POL1和第一相位延迟单元QWP1可以同时集成在光源(显示屏11)中。
本领域技术人员容易理解,第二相位补偿单元RB的相位补偿量不限于具体的数值,只要能够有助于提高光束初次入射到偏振分光片PBS时被反射的比例即可。另外,第二相位补偿单元RB可以由单个相位补偿片构成,也可以包括多个相位补偿片,本发明不限制其具体数量。在进行具体的光路设计时,在给定了波长、第一偏光片POL1、第一相位延迟单元QWP1、第二相位延迟单元QWP2、偏振分光片PBS的光学参数和器件方位参数之后,可进行第二相位补偿单元RB的设计,只要相比于未增加第二相位补偿单元RB时能够提高光束初次入射到偏振分光片PBS时被反射的比例即可。具体计算方法此处不再赘述。
进一步优选的,通过设定第一相位延迟单元QWP1的类型和光轴角度关系,可以进一步消除或者减少漏光。本发明中为了清楚描述,需要区分第二相位延迟单元QWP2和第一相位延迟单元QWP1的“正”和“负”的类型。“正”和“负”定义如下:
正相位延迟单元:令入射光束沿光轴方向的偏振分量产生N*λ+1/4λ的相位延迟,其中N为整数;
负相位延迟单元:令入射光束沿光轴方向的偏振分量产生M*λ+3/4λ的相位延迟,其中M为整数。
根据本发明的实施例,当满足以下关系时,漏光现象可以被进一步减轻:第一相位延迟单元QWP1和第二相位延迟单元QWP2同为正相位延迟单元或同为负相位延迟单元,并且满足以下关系:α
1=α
2=45°或135°;或者所述第一相位延迟单元和第二相位延迟单元为类型相反的正相位延迟单元或负相位延迟单元,并且满足以下关系: α
1=-α
2=45°或135°,
其中α
1和α
2如本发明第一方面中的定义。上面描述了角度α
1和α
2的关系,本领域技术人员容易理解,上述等式容许在工程可接受范围内的误差,例如当二者与目标角度之间的差异在正负5度的范围内时,均可认为满足上述等式。以目标角度α
1=α
2=45°为例,当实际中α
1=40°、α
2=50°时,可认为满足α
1=α
2=45°。
当光学模组包括第一偏光片POL1时,第一偏光片POL1的透光轴与入射到所述第一相位延迟单元QWP1上的线偏光正入射时的偏振方向D1是平行的,因此α
1即为逆着所述光路方向观察(即在图从左向右观察)、所述第一偏光片的透光轴逆时针旋转到第一相位延迟单元QWP1的光轴TQWP1所转过的角度。
另外,本发明中为了清楚起见,将区分初次(首次)入射到偏振分光片PBS的光束以及二次入射到偏振分光片PBS的光束。参考图13,光束E3’称为初次(首次)入射到偏振分光片PBS上的光束,光束E3称为初次(首次)入射到第二相位补偿单元RB上的光束;光束E6’称为二次入射到偏振分光片PBS上的光束,光束E6称为二次入射到第二相位补偿单元RB上的光束,光束E4、E5、E6和E6’均可称为折返光束。对于其余附图中的光路结构也可做相同的理解,此处不再赘述。
相比于现有技术的折叠光路的方案,通过本发明的技术方案,能够使得初次入射到所述偏振分光片上的光束透射通过偏振分光片的比例更小,因此产生的噪声(杂散光)更小。绝大部分光束被反射并形成折返光束,二次入射到偏振分光片上时,其偏振方向与所述偏振分光片的透光轴TPBS平行或尽可能平行,因而能够透射并形成信号(光)。另外,相比于单透镜单元的技术方案,本申请中,通过设置多个透镜单元,一方面能够增强人眼中的成像效果比如提高画面清晰度或者增大图像视场角,还可以提高成像模组的焦距使模组更加轻薄化,另外可以调节光学模组的屈光度以适应不同近视人群的裸眼观测需求。
本发明还涉及一种近眼显示装置,包括:显示屏和如上所述的光学模组,所述光学模组设置在所述显示屏的光路下游。
本发明的第一方面与第二方面的实施例,在不发生冲突或者矛盾的情况下,均可以自由结合。
最后应说明的是:以上所述仅为本发明的优选实施例而已,并不用于限制本发明,尽管参照前述实施例对本发明进行了详细的说明,对于本领域的技术人员来说,其依然可以对前述各实施例所记载的技术方案进行修改,或者对其中部分技术特征进行等同替换。凡在本发明的精神和原则之内,所作的任何修改、等同替换、改进等,均应包含在本发明的保护范围之内。
Claims (22)
- 一种光学模组,包括:半透半反层,接收圆偏光或椭圆偏光;第二相位延迟单元,位于所述半透半反层的光路下游,以接收所述透射的圆偏光或椭圆偏光并调制后出射;和偏振分光片,设置在所述第二相位延迟单元的光路下游,所述偏振分光片具有透光轴,其中所述光学模组还包括位于所述第二相位延迟单元和所述偏振分光片之间的第二相位补偿单元,其中所述第二相位补偿单元的光轴位于与所述偏振分光片的透光轴正交的平面内、或与所述偏振分光片的反光轴正交的平面内。
- 如权利要求1所述的光学模组,还包括位于所述半透半反层的光路上游的偏光片和第一相位延迟单元,所述偏光片配置成可产生线偏光,所述第一相位延迟单元从所述偏光片接收线偏光并将其调制为圆偏光或椭圆偏光后出射到所述半透半反层。
- 如权利要求1所述的光学模组,其中所述第二相位补偿单元配置成使得:根据初次入射到第二相位补偿单元上的各入射角的光束的偏振态分布,对其进行调制,使得初次入射到第二相位补偿单元上的各入射角的光束透过所述第二相位补偿单元后的偏振态符合被所述偏振分光器反射的条件。
- 如权利要求2所述的光学模组,其中所述第一相位延迟单元配置成可令入射到其上的线偏光沿光轴方向的偏振分量产生n*λ+3/4λ的相位延迟、或n*λ+1/4λ的相位延迟;第二相位延迟单元配置成可令入射到其上的线偏光沿光轴方向的偏振分量产生n*λ+3/4λ的相位延迟、或n*λ+1/4λ的相位延迟,其中n为整数。
- 如权利要求1-3中任一项所述的光学模组,其中被所述偏振分光片反射的光束透射通过所述第二相位补偿单元、第二相位延迟单元,被所述半透半反层部分反射,再次透射通过所述第二相位延迟单元和第二相位补偿单元,到达所述偏振分光片的折返光束的偏振方向与所述偏振分光片的透光轴平行。
- 如权利要求2所述的光学模组,其中所述第一相位延迟单元和第二相位延迟单 元同为正相位延迟单元或同为负相位延迟单元,并且满足以下关系:α 1=α 2=45°或135°,α 1为逆着所述光路方向观察、所述偏光片的透光轴逆时针旋转到第一相位延迟单元的光轴所述所转过的角度,α 2为逆着所述光路方向观察、所述偏振分光片的透光轴逆时针旋转到第二相位延迟单元的光轴所述所转过的角度。
- 如权利要求2所述的光学模组,其中所述第一相位延迟单元和第二相位延迟单元为类型相反的正相位延迟单元或负相位延迟单元,并且满足以下关系:α 1=-α 2=45°或135°,α 1为逆着所述光路方向观察、所述偏光片的透光轴逆时针旋转到第一相位延迟单元的光轴所述所转过的角度,α 2为逆着所述光路方向观察、所述偏振分光片的透光轴逆时针旋转到第二相位延迟单元的光轴所述所转过的角度。
- 如权利要求1-3中任一项所述的光学模组,其中所述第二相位补偿单元配置成使得:根据初次入射到第二相位补偿单元上的各入射角的光束的偏振态分布,对其进行调制,使得初次入射到第二相位补偿单元上的各入射角的光束透过所述第二相位补偿单元后的偏振态符合被所述偏振分光器反射的条件。
- 如权利要求2所述的光学模组,还包括位于所述第一相位延迟单元和所述偏光片之间的第一相位补偿单元。
- 如权利要求9所述的光学模组,其中所述第一相位补偿单元的光轴位于与所述偏光片的透光轴正交的平面内、或与所述偏光片的吸光轴正交的平面内,所述第一相位补偿单元配置成使得:根据从所述偏光片入射到其上的线偏光的偏振态分布对其进行调制,使得初次入射到所述偏振分光器上的光束的偏振态符合被所述偏振分光器反射的条件。
- 如权利要求1所述的光学模组,还包括位于所述偏振分光片的光路下游的第二偏光片。
- 如权利要求1所述的光学模组,还包括第一透镜单元,所述第一透镜单元与 所述半透半反层相邻设置,位于所述半透半反层的光路上游或下游,所述半透半反层贴附在所述第一透镜单元的表面上。
- 如权利要求12所述的光学模组,还包括第二透镜单元,所述第二透镜单元位于所述半透半反层的光路下游。
- 如权利要求13所述的光学模组,所述第二透镜单元位于所述偏振分光片的光路下游,或位于所述第二相位延迟单元的光路上游。
- 如权利要求13所述的光学模组,其中所述第一透镜单元和第二透镜单元配置成可将入射到所述第一透镜单元上的图像光成像到所述第二透镜单元的下游的用户眼中。
- 一种近眼显示装置,包括:显示屏;和如权利要求1-15中任一项所述的光学模组,设置在所述显示屏的光路下游。
- 一种光投射方法,包括:S101:通过半透半反层接收圆偏光或椭圆偏光,并允许所述圆偏光或椭圆偏光至少部分透射;S102:通过第二相位延迟单元接收所述透射的圆偏光或椭圆偏光并调制后出射;S103:通过位于所述第二相位延迟单元的光路下游的第二相位补偿单元从对来自所述第二相位延迟单元的光束进行调制并出射;S104:通过偏振分光片从所述第二相位补偿单元接收光束,所述偏振分光片设置在所述第二相位补偿单元的光路下游,所述偏振分光片具有透光轴,允许偏振方向与所述偏振分光片的透光轴平行的部分光束透射,并将其余部分光束反射回所述第二相位延迟片,其中所述第二相位补偿单元的光轴位于与所述偏振分光片的透光轴正交的平面内、或与所述偏振分光片的反光轴正交的平面内。
- 如权利要求17所述的光投射方法,其中所述第二相位补偿单元配置成使得: 根据初次入射到第二相位补偿单元上的各入射角的光束的偏振态分布,对其进行调制,使得初次入射到第二相位补偿单元上的各入射角的光束透过所述第二相位补偿单元后的偏振态符合被所述偏振分光器反射的条件。
- 如权利要求17所述的光投射方法,还包括:通过偏光片产生线偏光;通过第一相位延迟单元从所述偏光片接收线偏光,转换为圆偏光或椭圆偏光并保护射到所述半透半反层上。
- 如权利要求17-19中任一项所述的光投射方法,还包括,通过位于所述第一相位延迟单元和所述偏光片之间的第一相位补偿单元对来自所述偏光片的线偏光进行调制后使其入射到所述第一相位延迟单元,其中所述第一相位补偿单元的光轴位于与所述偏光片的透光轴正交的平面内、或与所述偏光片的吸光轴垂直的平面内,其中所述第一相位补偿单元配置成使得:根据从所述偏光片入射到其上的线偏光的偏振态分布对其进行调制,使得初次入射到所述偏振分光器上的光束的偏振态符合被所述偏振分光器反射的条件。
- 如权利要求17-19中任一项所述的光投射方法,其中所述第一相位延迟单元和第二相位延迟单元同为正相位延迟单元或同为负相位延迟单元,并且满足以下关系:α 1=α 2=45°或135°;或者所述第一相位延迟单元和第二相位延迟单元为类型相反的正相位延迟单元或负相位延迟单元,并且满足以下关系:α 1=-α 2=45°或135°,其中α 1为逆着所述光路方向观察、所述偏光片的透光轴逆时针旋转到第一相位延迟单元的光轴所述所转过的角度,α 2为逆着所述光路方向观察、所述偏振分光片的透光轴逆时针旋转到第二相位延迟单元的光轴所述所转过的角度。
- 如权利要求17-19中任一项所述的光投射方法,其中所述光投射方法通过如权利要求1-15中任一项所述的光学模组实施。
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP21874610.5A EP4224240A4 (en) | 2020-09-30 | 2021-11-03 | OPTICAL MODULE, NEAR-EYE DISPLAY DEVICE AND LIGHT PROJECTION METHOD |
Applications Claiming Priority (10)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202011061771 | 2020-09-30 | ||
CN202022206054.7 | 2020-09-30 | ||
CN202011061771.3 | 2020-09-30 | ||
CN202022206054 | 2020-09-30 | ||
CN202022504347.3U CN217506272U (zh) | 2020-09-30 | 2020-11-03 | 光学模组和近眼显示装置 |
CN202011210641.1 | 2020-11-03 | ||
CN202022504347.3 | 2020-11-03 | ||
CN202011210641.1A CN112379519B (zh) | 2020-09-30 | 2020-11-03 | 光学模组、近眼显示装置和光投射方法 |
CN202121273674.0 | 2021-06-08 | ||
CN202121273674.0U CN215181229U (zh) | 2021-06-08 | 2021-06-08 | 光学模组和近眼显示装置 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2022068956A1 true WO2022068956A1 (zh) | 2022-04-07 |
Family
ID=80822453
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/CN2021/128391 WO2022068956A1 (zh) | 2020-09-30 | 2021-11-03 | 光学模组、近眼显示装置和光投射方法 |
Country Status (3)
Country | Link |
---|---|
US (1) | US11747640B2 (zh) |
EP (1) | EP4224240A4 (zh) |
WO (1) | WO2022068956A1 (zh) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN115113405B (zh) * | 2022-07-15 | 2024-07-23 | 联创电子科技股份有限公司 | 具有折叠光路的光学模组、近眼显示装置和光投射方法 |
Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6400493B1 (en) * | 1999-10-26 | 2002-06-04 | Agilent Technologies, Inc. | Folded optical system adapted for head-mounted displays |
US20110025965A1 (en) * | 2009-07-31 | 2011-02-03 | Canon Kabushiki Kaisha | Projection image display apparatus |
CN109946837A (zh) * | 2018-08-31 | 2019-06-28 | 华为技术有限公司 | 一种光学成像系统 |
CN209356760U (zh) * | 2019-03-08 | 2019-09-06 | 歌尔科技有限公司 | 光学成像结构及头戴显示设备 |
CN110716314A (zh) * | 2019-11-26 | 2020-01-21 | 深圳惠牛科技有限公司 | 一种轻薄型光学模组及vr设备 |
US20200284963A1 (en) * | 2017-10-25 | 2020-09-10 | 3M Innovative Properties Company | Optical retarder segements |
CN112379519A (zh) * | 2020-09-30 | 2021-02-19 | 上海悠睿光学有限公司 | 光学模组、近眼显示装置和光投射方法 |
CN112526754A (zh) * | 2020-12-10 | 2021-03-19 | 深圳惠牛科技有限公司 | 显示器件及头戴式显示器 |
CN113485012A (zh) * | 2021-06-29 | 2021-10-08 | 京东方科技集团股份有限公司 | 折叠光路结构、光学成像系统及虚拟现实设备 |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7773299B2 (en) * | 2007-05-31 | 2010-08-10 | Aither Optics Inc. | Controlling light transmission in a vehicle with polarization and ellipticity adjustment |
US11226482B2 (en) * | 2018-06-07 | 2022-01-18 | Facebook Technologies, Llc | Reverse-order crossed pancake lens with azimuthal compensation |
CN217506273U (zh) * | 2020-09-30 | 2022-09-27 | 上海悠睿光学有限公司 | 光学模组和近眼显示装置 |
CN112630965A (zh) * | 2020-09-30 | 2021-04-09 | 上海悠睿光学有限公司 | 光学模组、近眼显示装置和光投射方法 |
CN112255794B (zh) * | 2020-10-28 | 2022-07-19 | 上海悠睿光学有限公司 | 光学模组、近眼显示装置和光投射方法 |
-
2021
- 2021-08-30 US US17/461,119 patent/US11747640B2/en active Active
- 2021-11-03 WO PCT/CN2021/128391 patent/WO2022068956A1/zh unknown
- 2021-11-03 EP EP21874610.5A patent/EP4224240A4/en active Pending
Patent Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6400493B1 (en) * | 1999-10-26 | 2002-06-04 | Agilent Technologies, Inc. | Folded optical system adapted for head-mounted displays |
US20110025965A1 (en) * | 2009-07-31 | 2011-02-03 | Canon Kabushiki Kaisha | Projection image display apparatus |
US20200284963A1 (en) * | 2017-10-25 | 2020-09-10 | 3M Innovative Properties Company | Optical retarder segements |
CN109946837A (zh) * | 2018-08-31 | 2019-06-28 | 华为技术有限公司 | 一种光学成像系统 |
CN209356760U (zh) * | 2019-03-08 | 2019-09-06 | 歌尔科技有限公司 | 光学成像结构及头戴显示设备 |
CN110716314A (zh) * | 2019-11-26 | 2020-01-21 | 深圳惠牛科技有限公司 | 一种轻薄型光学模组及vr设备 |
CN112379519A (zh) * | 2020-09-30 | 2021-02-19 | 上海悠睿光学有限公司 | 光学模组、近眼显示装置和光投射方法 |
CN112526754A (zh) * | 2020-12-10 | 2021-03-19 | 深圳惠牛科技有限公司 | 显示器件及头戴式显示器 |
CN113485012A (zh) * | 2021-06-29 | 2021-10-08 | 京东方科技集团股份有限公司 | 折叠光路结构、光学成像系统及虚拟现实设备 |
Non-Patent Citations (1)
Title |
---|
See also references of EP4224240A4 * |
Also Published As
Publication number | Publication date |
---|---|
US11747640B2 (en) | 2023-09-05 |
EP4224240A4 (en) | 2024-05-08 |
US20220099988A1 (en) | 2022-03-31 |
EP4224240A1 (en) | 2023-08-09 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN217506273U (zh) | 光学模组和近眼显示装置 | |
US9235111B2 (en) | Projection display apparatus | |
CN217506272U (zh) | 光学模组和近眼显示装置 | |
WO2017008414A1 (zh) | 短距离光学放大模组及使用其的近眼显示光学模组 | |
CN112255794B (zh) | 光学模组、近眼显示装置和光投射方法 | |
WO2020181882A1 (zh) | 一种光学系统及显示设备 | |
CN111025658B (zh) | 一种增强现实光学模组及增强现实设备 | |
CN110320668B (zh) | 光学系统及具有其的虚拟现实设备 | |
WO2020244210A1 (zh) | 光学系统及具有其的虚拟现实设备 | |
US8955977B2 (en) | Projection-type image display apparatus | |
US20240230953A1 (en) | Relay redirector, display device and near-eye display system | |
CN209858857U (zh) | 光学系统及具有其的虚拟现实设备 | |
US20230176381A1 (en) | Augmented reality display system and ar goggle | |
WO2023092705A1 (zh) | 光学模组和头戴显示设备 | |
US20230145899A1 (en) | Optical apparatus and near-eye display device | |
WO2022068956A1 (zh) | 光学模组、近眼显示装置和光投射方法 | |
CN217279117U (zh) | 光学模组和近眼显示装置 | |
WO2023273991A1 (zh) | 光学系统和可穿戴设备 | |
CN215181229U (zh) | 光学模组和近眼显示装置 | |
WO2020220711A1 (zh) | 光学系统及具有其的虚拟现实设备 | |
US20220155513A1 (en) | Liquid crystal reflective polarizer and pancake lens assembly having the same | |
WO2019119258A1 (zh) | 光学系统及近眼显示装置 | |
US20220350154A1 (en) | Polarization optimized heads-up display | |
CN220367482U (zh) | 用于近眼显示设备的光学模组及近眼显示设备 | |
CN117647895A (zh) | 光学模组以及近眼显示装置 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 21874610 Country of ref document: EP Kind code of ref document: A1 |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
ENP | Entry into the national phase |
Ref document number: 2021874610 Country of ref document: EP Effective date: 20230502 |