WO2022052769A1 - 光学成像系统及头戴显示装置 - Google Patents

光学成像系统及头戴显示装置 Download PDF

Info

Publication number
WO2022052769A1
WO2022052769A1 PCT/CN2021/113421 CN2021113421W WO2022052769A1 WO 2022052769 A1 WO2022052769 A1 WO 2022052769A1 CN 2021113421 W CN2021113421 W CN 2021113421W WO 2022052769 A1 WO2022052769 A1 WO 2022052769A1
Authority
WO
WIPO (PCT)
Prior art keywords
cover plate
imaging system
optical imaging
display screen
lens
Prior art date
Application number
PCT/CN2021/113421
Other languages
English (en)
French (fr)
Inventor
罗诚
靳云峰
Original Assignee
华为技术有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 华为技术有限公司 filed Critical 华为技术有限公司
Priority to JP2023515872A priority Critical patent/JP2023540387A/ja
Priority to US18/044,749 priority patent/US20230367122A1/en
Priority to EP21865825.0A priority patent/EP4198609A4/en
Publication of WO2022052769A1 publication Critical patent/WO2022052769A1/zh

Links

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
    • G02B27/01—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
    • G02B25/00—Eyepieces; Magnifying glasses
    • G02B25/001—Eyepieces
    • 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
    • G02B27/09—Beam shaping, e.g. changing the cross-sectional area, not otherwise provided for
    • G02B27/0938—Using specific optical elements
    • G02B27/095—Refractive optical elements
    • G02B27/0955—Lenses
    • 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
    • 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
    • G02B2027/0138—Head-up displays characterised by optical features comprising image capture systems, e.g. camera
    • 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
    • G02B2027/0178—Eyeglass type

Definitions

  • the present application relates to the field of optical technology, and in particular, to an optical imaging system and a head-mounted display device.
  • VR Virtual Reality
  • AR refers to the projection of digital content to the human eye through an optical imaging system, allowing users to feel as if they are in a virtual world and realize an immersive virtual experience.
  • users can use the head-mounted display device to see the pictures in the virtual world, and the optical imaging system is a key component in the head-mounted display device.
  • the optical imaging system includes a display screen and a lens group.
  • the light emitted by the display screen is refracted by the lens group and then enters the pupil of the human eye.
  • the reverse extension line of the light entering the through hole of the human eye converges at a distance to form a virtual image, which is viewed by the human eye.
  • the image is the virtual image, and the virtual image is the enlarged image of the image displayed on the display screen.
  • foreign objects such as dust, dander, and fiber debris may fall between the display screen and the lens group.
  • the foreign objects When the human eye observes the display screen through the optical imaging system, the foreign objects will be imaged, resulting in black spots and black lines. , bright spots, bright lines, etc. display poor.
  • the present application provides an optical imaging system and a head-mounted display device, which can make display defects caused by foreign objects between the display screen and the lens group difficult to be detected by human eyes.
  • embodiments of the present application provide an optical imaging system, including a display screen and a lens group; the display screen is located on a side of the lens group away from human eyes, the display screen includes a display panel and a cover plate, and the display screen includes a display panel and a cover plate.
  • the cover plate is arranged on the side of the display panel facing the lens group, and the thickness of the cover plate satisfies:
  • f' is the equivalent image square focal length of the lens group
  • n is the refractive index of the cover plate
  • a is the photopic distance of the human eye.
  • the thickness of the cover plate is increased to a certain proportion of the focal length of the optical imaging system, so as to increase the thickness of the cover plate between the lens group and the display screen.
  • the image distance of the foreign object on the cover surface is far from the image distance of the display image, showing a blurring effect, which cannot be seen by the human eye. Clear capture, resulting in poor display such as black spots, black lines, bright spots, bright lines, etc. can go unnoticed.
  • a is not greater than 300 mm.
  • the photopic distance is the shortest distance at which the human eye can see the object clearly.
  • the range of the photopic distance does not exceed 300mm.
  • the photopic distance is substituted into the above formula. , which can make the image of foreign objects on the surface of the cover plate appear blurred.
  • the cover plate includes a first cover plate covering the display panel and a second cover plate disposed on the first cover plate, and the second cover plate is bonded on the first cover.
  • the display screen is generally covered with a thin protective layer as the first cover plate on the surface of the display panel.
  • a thin protective layer as the first cover plate on the surface of the display panel.
  • a second cover plate is added on the surface of the screen, and the second cover plate can be arranged on the display screen by means of bonding, etc., the process is simple and easy to realize, and the cost is low.
  • the thickness of the cover plate is less than 3.5 mm.
  • the thickness of the cover plate is in the range of less than 3.5mm, so as to make the image distance of the foreign matter on the surface of the cover plate and the image distance of the displayed image farther, and to prevent the excessive thickness of the cover plate from affecting the optical imaging system.
  • the volume and weight have a great influence, and it satisfies the light and thin design of the optical imaging system as a whole.
  • the cover plate is made of transparent glass or plastic, and the refractive index of the cover plate is in the range of 1.3-1.9.
  • the cover plate of the display screen is set to optical glass or optical plastic.
  • the refractive index and density of the cover plate of different materials are different.
  • selecting a material with a smaller refractive index as the cover plate can make the thickness of the cover plate smaller. Try to make it as thin as possible to meet the overall thin and light design of the optical imaging system.
  • the equivalent image-square focal length of the lens group is in the range of 10mm-60mm.
  • the focal length of the lens group tends to be smaller.
  • the smaller the focal length of the lens group the greater the corresponding magnification.
  • the lens group includes at least one lens, and the lens includes a Fresnel lens, a plano-convex lens, a biconvex lens, a positive meniscus lens, a plano-concave lens, a biconcave lens, or a negative meniscus lens.
  • the lens group of the optical imaging system can be set with different types of lenses and the number of lenses, and the combination of lenses can improve the imaging quality and meet more imaging needs.
  • a head-mounted display device including a device body, a wearing part, and the above-mentioned optical imaging system installed in the device body.
  • the head-mounted display device includes a device main body and a wearing part.
  • the device main body is located in front of the user's eyes to provide a display screen for the user's eyes, and the wearing part is used to be fixed on the user's head or On the ear, the reliable wearing of the head-mounted display device is realized.
  • the optical imaging system is arranged in the main body of the device to realize the display of the virtual picture.
  • the head-mounted display device includes virtual reality glasses.
  • the head-mounted display device may be in the form of glasses.
  • the main body of the device may include a frame mounted on the bridge of the user's nose and in front of the user's eyes, and the wearing part may be a temple mounted on the user's ear.
  • Embodiments of the present application provide an optical imaging system and a head-mounted display device.
  • the thickness of the cover plate is increased to a certain proportion of the focal length of the optical imaging system, so as to increase the thickness of the cover plate on the lens.
  • the distance between the foreign object between the group and the display screen and the display panel, so that the display image on the display panel is clearly imaged, the image distance of the foreign object on the cover surface is far from the image distance of the display image, and the image is blurred.
  • the effect cannot be clearly captured by the human eye, resulting in poor display such as black spots, black lines, bright spots, and bright lines that cannot be detected.
  • FIG. 1 is a schematic structural diagram of a head-mounted display device according to an embodiment of the present application
  • FIG. 2 is a schematic structural diagram of another angle of a head-mounted display device provided by an embodiment of the present application.
  • FIG. 3 is a schematic structural diagram of an optical imaging system provided by the related art
  • FIG. 4 is a schematic diagram of the imaging principle of the optical imaging system provided by the related art.
  • FIG. 5 is an imaging schematic diagram of a head-mounted display device provided by the related art
  • FIG. 6 is a schematic diagram of an imaging principle of an optical imaging system provided by an embodiment of the present application.
  • FIG. 7 is a schematic diagram of an object-image relationship of an optical imaging system according to an embodiment of the present application.
  • FIG. 8 is a schematic imaging diagram of a head-mounted display device according to an embodiment of the present application.
  • FIG. 9 is a schematic structural diagram of an optical imaging system provided by an embodiment of the present application before optimization.
  • FIG. 10 is a schematic structural diagram of the optical imaging system provided in FIG. 9 after optimization;
  • FIG. 11 is a schematic structural diagram of an optical imaging system before optimization provided by another embodiment of the application.
  • FIG. 12 is a schematic structural diagram of the optical imaging system provided in FIG. 11 after optimization.
  • 100-head mounted display device 11-device body; 12-wearing part; 200-optical imaging system; 21-display screen; 211-display panel; 212-cover; 212a-first cover; 212b-second cover plate; 22-lens group; 221-first lens; 222-second lens; 223-third lens; 224-fourth lens; 225-fifth lens; 300-foreign body.
  • FIG. 1 is a schematic structural diagram of a head-mounted display device according to an embodiment of the application
  • FIG. 2 is a schematic structural diagram of another angle of the head-mounted display device according to an embodiment of the application.
  • an embodiment of the present application provides a head-mounted display device 100 .
  • the head-mounted display device 100 includes a device body 11 and a wearing part 12 .
  • the device body 11 is located at The front of the user's eyes is used to provide a display screen for the user's eyes, and the wearing part 12 is used to be fixed on the user's head or ears, so as to realize reliable wearing of the head-mounted display device 100 .
  • the head-mounted display device 100 may be in the form of glasses.
  • the device body 11 may include a frame mounted above the bridge of the user's nose and in front of the user's eyes, and the wearing part 12 may be a temple mounted on the user's ear.
  • the head-mounted display device 100 can also be in the form of a helmet or the like, the device body 11 can be an eye mask that is placed in front of the user's eyes, and the wearing part 12 can be a helmet that is placed on the user's head.
  • the device main body 11 is provided with an optical imaging system 200 to realize the display of a virtual image.
  • the number of optical imaging systems 200 may be two, corresponding to the user's left eye and right eye respectively.
  • the two optical imaging systems 200 can achieve the purpose of stereoscopic imaging by means of interlaced display, image exchange or parallax fusion.
  • FIG. 3 is a schematic structural diagram of an optical imaging system provided by the related art.
  • the optical imaging system 200 includes a display screen 21 and a lens group 22.
  • the display screen 21 is located on the side of the lens group 22 away from the human eye.
  • the display screen 21 is used to display images, and the light emitted by the display screen 21 passes through the lens Group 22 enters the human eye after refraction or reflection.
  • the display screen 21 includes a display panel 211 and a cover plate 212.
  • the display panel 211 includes a laminated structure such as a light-emitting layer, an optical adhesive layer, a polarizer, etc.
  • the display panel 211 is used for display as a whole. In fact, the light-emitting layer emits light.
  • the overall thickness of the display panel 211 is less than 0.2 mm, and the thickness of each internal layer can be ignored, and it is considered that light is emitted from the side surface of the display panel 211 facing the lens group 22 .
  • the cover plate 212 is disposed on the display panel 211 to protect the display panel 211 .
  • the lens group 22 can be composed of at least one lens, which includes but is not limited to Fresnel lenses, plano-convex lenses, biconvex lenses, positive meniscus lenses, plano-concave lenses, biconcave lenses, negative meniscus lenses, etc. , so that the light emitted by the display screen 21 enters the human eye in a state of approximately parallel light after being refracted or reflected by one or more lenses.
  • the working principle of the optical imaging system 200 of the head-mounted display device 100 is that the position of the display screen 21 is fixed, and the light emitted by the display screen 21 is imaged to the human eye at a certain image distance through the lens group 22, and the human eye can observe it. to the image at a fixed image distance position.
  • a gap between the display screen 21 and the lens group 22 there is a gap between the display screen 21 and the lens group 22 , and the gap is at least 0.2 mm to prevent collision between the display screen 21 and the lens group 22 .
  • a sealing structure such as a sealing ring is arranged on the periphery to prevent dust in the external environment from entering the gap between the display screen 21 and the lens group 22 .
  • the head mounted display device 100 can be assembled in a class 100 clean room.
  • a static class 100 clean room the diameter of particles in the air is mostly below 1 ⁇ m, which can be ignored.
  • the diameter of these foreign bodies is between 10 ⁇ m and 2000 ⁇ m.
  • the size of foreign objects is small, and it is difficult for the staff who assemble the head-mounted display device 100 to find and clean them. Therefore, after the display screen 21 and the lens group 22 are assembled, the foreign objects may fall into the gap between the display screen 21 and the lens group 22 , such as the surface of the cover plate 212 adhered to the display screen 21 .
  • FIG. 4 is a schematic diagram of an imaging principle of an optical imaging system provided in the related art
  • FIG. 5 is a schematic diagram of an imaging diagram of a head-mounted display device provided in the related art.
  • the side surface of the cover plate 212 facing the lens group 22 is adhered with a foreign object 300 .
  • there are two types of light entering the human eye through the lens group 22 .
  • the first type is the light emitted by the display panel 211 , such as the point p on the display panel 211
  • the second type is the light emitted by the foreign object 300 , such as the point q on the foreign object 300 .
  • the light emitted by the point p on the display panel 211 can enter the human eye as nearly parallel light after passing through the lens group 22, and the image distance of the virtual image p' is in the range of 1 meter to infinity.
  • the thickness h' of the cover plate 212 is small, the light from the point q on the foreign object 300 passes through the lens group 22 and also enters the human eye as a nearly parallel light, and the image distance of the virtual image q' is in the range of 1 meter to infinity.
  • the positions of the two virtual images p' and q' are close, and both are within the visual range of the human eye. .
  • the equivalent focal length of the lens group 22 in the head-mounted display device 100 is generally in the range of 10mm-100mm, and the corresponding magnification is in the range of 2.5 times-25 times.
  • the equivalent focal length of the lens group 22 can be reduced to a range of 10mm-60mm.
  • the diameter of the displayed virtual image can reach a size range of millimeters or even centimeters, which is large enough to be captured by the user's eyes.
  • the extremely small foreign objects 300 such as dander, fiber debris, dust, etc. adhering to the display screen 21 during the assembly process, after being enlarged and imaged by the optical imaging system 200, Poor display such as black dots, black lines, bright spots, bright lines, etc. will occur, which will affect the display effect of the head-mounted display device 100, resulting in poor user experience.
  • the embodiments of the present application provide an optical imaging system and a head-mounted display device.
  • the thickness of the cover plate is increased to a certain proportion of the focal length of the optical imaging system, so as to increase the thickness of the cover plate.
  • the distance between the foreign object falling between the lens group and the display screen and the display panel is large, so that the image distance of the foreign object on the cover surface is farther from the image distance of the displayed image when the display image on the display panel is clearly imaged. , showing a blur effect, which cannot be clearly captured by the human eye, resulting in poor display such as black spots, black lines, bright spots, and bright lines that cannot be detected.
  • FIG. 6 is a schematic diagram of the imaging principle of an optical imaging system provided by an embodiment of the present application.
  • the optical imaging system 200 includes a display screen 21 and a lens group 22 , and the display screen 21 is located in the lens group 22
  • the display screen 21 includes a display panel 211 and a cover plate 212 , and the cover plate 212 is connected to the side of the display panel 211 facing the lens group 22 .
  • n is the refractive index of the cover plate 212
  • f' is the equivalent image-side focal length (unit mm) of the optical imaging system 200
  • f' is a positive value
  • its size is equal to the size of the equivalent object-side focal length
  • a represents the human The visual distance of the eye, the range is not more than 300mm.
  • the thickness h of the cover plate 212 in the embodiment of the present application is greater than the thickness h′ of the cover plate 212 in the related art, and the distance between the foreign objects 300 on the surface of the cover plate 212 and the display panel 211 increases.
  • FIG. 7 is a schematic diagram of an object-image relationship of an optical imaging system according to an embodiment of the present application.
  • HH' is the thickness of the equivalent lens of the optical imaging system 200
  • B is the object to be imaged
  • B' is the virtual image after B is imaged
  • F is the focal point of the equivalent lens of the optical imaging system 200.
  • L' is the distance from the virtual image to the equivalent lens of the optical imaging system 200
  • L is the distance from the display panel 211 to the equivalent lens of the optical imaging system 200 .
  • the object distance of the point p is defined as L1 and the image distance is L1 ′.
  • the object distance L1 is less than the distance between the display panel 211 and the lens group 22, and is less than 60 mm
  • the image distance L1' that is, the virtual image distance of the display screen observed by the human eye, is in the range of 1 meter to infinity . Therefore, L1' is much larger than L1, and the above object image formula can be simplified as:
  • the object distance of the point q is L2
  • the image distance of the point q is L2'
  • the relationship between L2 and L1 satisfies the following formula:
  • Equation 3 Substitute Equation 3 and Equation 4 into Equation 5, the following formula can be obtained:
  • the reciprocal of the virtual image distance represents the diopter
  • 1/L2' is the reciprocal of the virtual image distance of the point q, which represents the virtual diopter of the foreign object 300 on the surface of the cover plate 212.
  • the photopic distance a is not greater than 300mm.
  • the photopic distance is about 250mm.
  • the photopic distance is shorter than 250mm.
  • Hyperopia photopic distance longer than 250mm.
  • Formula 1 can be obtained by substituting the situation that the human eye cannot see the foreign object at the photopic distance a at the same time when looking at infinity into Formula 7.
  • the distance between the virtual image of the point q of the foreign object 300 and the human eye is within the range of 300 mm. Since the imaging virtual image distance of the display screen observed by the human eye at this time is 1 meter to infinity, the foreign object is The virtual image viewing angle of the point q of 300 is significantly greater than the virtual image viewing degree of the point p on the display panel 211 , and it can be considered that the human eye cannot perceive the image of the foreign object 300 of a certain size.
  • the maximum value of the photopic distance a of 300mm is substituted into Formula 8 obtained by Formula 1, and the range of h includes the range of h corresponding to when a is less than 300mm.
  • FIG. 8 is a schematic imaging diagram of a head-mounted display device according to an embodiment of the present application.
  • the light emitted from the point p on the display panel 211 can enter the human eye as nearly parallel light after passing through the lens group 22, and the image distance of the virtual image p" is in the range of 1 meter to infinity.
  • the cover plate 212 When the thickness h satisfies Formula 8, the point q of the foreign object 300 on the surface of the cover plate 212 has an image distance of the virtual image q" within the range of less than 300 mm. At this time, the virtual image visibility of the foreign object 300 is significantly larger than that of the display screen of the display panel 211 , and the virtual image size of the foreign object 300 is small, which can be considered undetectable by the human eye.
  • the cover plate 212 can be a protective layer attached to the surface of the display panel 211 during the production process of the display screen 200 .
  • the thickness of the cover plate 212 can satisfy the formula 8, so as to blur the foreign matter on the display screen 200 . imaging.
  • the thickness of its own first cover plate cannot satisfy formula 8, and an additional layer of flat material can be added on the display screen 200 as the second cover plate, so that the The sum of the thicknesses of the second cover plate and the first cover plate satisfies Formula 8, so as to blur the image of foreign objects on the display screen 200 .
  • the material of the cover plate 212 includes but is not limited to transparent materials such as glass and plastic, and the refractive index of the cover plate may be in the range of 1.3-1.9.
  • the first cover plate covers the surface of the display panel 211 , and may be a film layer formed by deposition or the like during the manufacture of the display panel 211 , or connected to the display panel 211 by means of optical adhesive bonding.
  • the second cover plate can also be bonded to the first cover plate by optical glue, so as not to affect the display effect of the display panel 211 .
  • the display panel 211 has a display area and a non-display area around the display area
  • the second cover plate and the first cover plate can be bonded by glue or adhesive, and the glue or adhesive can be arranged in the area corresponding to the non-display area in order to avoid affecting the normal display of the display area.
  • a structural member can also be arranged around the display screen and the second cover plate, so that the second cover plate is arranged in close contact with the first cover plate.
  • the first cover plate and the second cover plate can be made of the same material, or they can be made of different materials.
  • the refractive indices of the two are similar, and the thickness of the first cover plate is much smaller than that of the second cover plate Therefore, when using the above formula to calculate the thickness of the second cover plate to be added, the difference in refractive index between the two can be ignored, and the refractive index of the second cover plate is substituted into the formula for calculation.
  • the thickness of the cover plate 212 may be less than 3.5 mm, so as to prevent the excessive thickness of the cover plate 212 from greatly affecting the volume and weight of the optical imaging system.
  • the distance between the foreign objects on the surface of the display screen and the display panel can be increased, so that the visual degree of the virtual image of the foreign object is greater than that represented by the clear vision distance of the human eye. , so that the position of the virtual image of the foreign object is far away from the virtual image of the display screen, ensuring that when the human eye observes the display screen through the optical imaging system, the black spots, black lines, bright spots, bright lines, etc. caused by foreign objects on the surface of the display screen are poorly displayed. , which cannot be clearly captured by the human eye.
  • optical imaging system and the head-mounted display device provided by the embodiments of the present application will be described below with reference to more specific embodiments.
  • FIG. 9 is a schematic structural diagram of an optical imaging system before optimization according to an embodiment of the present application.
  • the optical imaging system 200 includes a display screen 21 and a lens group 22, the display screen 21 may be an LCD (Liquid Crystal Display, liquid crystal display), and the lens group 22 may include a lens, and the lens may be a Fresnel lens , the surfaces on both sides of the lens are respectively the S1 surface and the S2 surface, the S2 surface is located on the side facing the display screen 21 , and the S1 surface is located on the side facing away from the display screen 21 and facing the human eye.
  • the equivalent focal length f of the lens group 22 is 24.67 mm under 530 nm illumination, the thickness of the first cover plate 212 a of the display screen 21 itself is relatively thin, and various parameters of the optical imaging system 200 are shown in Table 1.
  • the radius of curvature and thickness of the lens S1 refers to the radius of curvature and thickness corresponding to the center of the lens S1.
  • the thickness of the first cover plate 212a of the display screen 21 is set to 0.2 mm
  • the material is glass of type H-K9L
  • the corresponding refractive index n 1.52
  • the distance between the center of the S2 surface of the lens is the first
  • the distance between the surface of the cover plate 212a is 23.5mm
  • the center thickness of the lens is 5mm
  • the material is polymethyl methacrylate PMMA.
  • the virtual image distance of the foreign object in the center of the surface of the first cover plate 212a is 1130 mm, and the corresponding viewing angle is 0.88D. It can be seen that the distance between the virtual image of the display screen and the virtual image of the foreign object on the surface of the cover plate 212a is relatively close, and the virtual image of the foreign object is easily captured by the human eye, thereby affecting the viewing effect of the display screen.
  • FIG. 10 is a schematic structural diagram of the optical imaging system provided in FIG. 9 after optimization.
  • the embodiment of the present application solves this problem by adding a second cover plate 212b on the display screen 21.
  • the material and refractive index of the newly added second cover plate 212b are the same as those of the first cover plate 212a.
  • various parameters of the optical imaging system 200 are shown in Table 2.
  • the virtual image distance of the foreign object in the center of the surface of the cover plate 212 is 257 mm, and the corresponding viewing angle is 3.89D. It can be seen that after the second cover plate 212b is added, the virtual image caused by the foreign matter attached to the cover plate 212 requires the human eye to adjust the 3.89D diopter to complete refocusing, which is not easy to be found.
  • FIG. 11 is a schematic structural diagram of an optical imaging system before optimization provided by another embodiment of the present application.
  • the optical imaging system 200 includes a display screen 21 and a lens group 22, the display screen 21 may be an OLED (Organic Light Emitting Diode, organic light-emitting diode), and the lens group 22 may include a first lens 221, a second lens set in sequence The second lens 222 , the third lens 223 , the fourth lens 224 and the fifth lens 225 , the fifth lens 225 is the closest to the display screen 21 , each lens includes an S1 surface and an S2 surface, and the S2 surface is located facing the display screen 21 .
  • OLED Organic Light Emitting Diode, organic light-emitting diode
  • the S1 surface is located on the side facing away from the display screen 21 and facing the human eye.
  • the equivalent focal length f of the lens group 22 is 21.56 mm under 530 nm illumination, the thickness of the first cover 212 a of the display screen 21 itself is relatively thin, and various parameters of the optical imaging system 200 are shown in Table 3.
  • the curvature radius and thickness of the first lens S1 refers to the curvature radius and thickness corresponding to the center of the lens S1.
  • the thickness of the first cover plate 212a of the display screen 21 is set to 0.7mm
  • the material is H-K9L glass
  • the corresponding refractive index n 1.52
  • the S2 surface of the fifth lens 225 The distance between the surface of a cover plate 212a is 1.46mm
  • the lens materials APL, OKP, and E48R are different types of optical plastics respectively.
  • the virtual image distance of the foreign object in the center of the surface of the first cover plate 212a is 972 mm, and the corresponding viewing angle is 1.03D. It can be seen that the distance between the virtual image of the display screen and the virtual image of the foreign object on the surface of the first cover plate 212a is relatively close, and the virtual image of the foreign object is easily captured by the human eye, thereby affecting the viewing effect of the display screen.
  • FIG. 12 is a schematic structural diagram of the optical imaging system provided in FIG. 11 after optimization.
  • the embodiment of the present application solves this problem by adding a second cover plate 212b on the display screen 21.
  • the material and refractive index of the newly added second cover plate 212b are the same as those of the first cover plate 212a.
  • various parameters of the optical imaging system 200 are shown in Table 4.
  • the virtual image distance of the foreign object in the center of the surface of the cover plate 212 is 298 mm, and the corresponding viewing angle is 3.36D. It can be seen that, after the second cover plate 212b is added, the virtual image caused by the foreign matter attached to the cover plate 212 requires the human eye to adjust the 3.36D diopter to complete refocusing, which is not easy to be found.
  • the terms “installed”, “connected” and “connected” should be understood in a broad sense, for example, it may be a fixed connection or an intermediate medium.
  • the indirect connection can be the internal communication of the two elements or the interaction relationship between the two elements.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Lenses (AREA)

Abstract

一种光学成像系统（200）及头戴显示装置（100），光学成像系统（200）包括显示屏（21）和透镜组（22）；显示屏（21）位于透镜组（22）的远离人眼的一侧，显示屏（21）包括显示面板（211）和盖板（212），盖板（212）设置在显示面板（211）的面向透镜组（22）的一侧，盖板（212）的厚度范围与透镜组（22）的等效像方焦距（f'）、盖板（212）的折射率（n）及人眼的明视距离（a）相关。光学成像系统（200）及头戴显示装置（100），可以使显示屏（21）和透镜组（22）之间的异物（300）造成的显示不良不易被人眼察觉到。

Description

光学成像系统及头戴显示装置
本申请要求于2020年09月11日提交中国专利局、申请号为202010955672.3、申请名称为“光学成像系统及头戴显示装置”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本申请涉及光学技术领域，尤其涉及一种光学成像系统及头戴显示装置。
背景技术
虚拟现实(Virtual Reality，VR)指的是通过光学成像系统将数字化的内容投射到人眼，让用户仿佛置身于虚拟世界之中，实现沉浸式虚拟体验。随着VR技术的不断发展，用户能够利用头戴显示装置看到虚拟世界中的画面，光学成像系统是头戴显示装置中的关键部件。
光学成像系统包括显示屏和透镜组，显示屏发出的光经过透镜组折射后入设到人眼瞳孔，进入人眼通孔的光线的反向延长线汇聚在远处形成虚像，人眼观看到的图像为该虚像，该虚像为显示屏显示的图像放大后的像。
生产装配过程中，显示屏和透镜组之间可能会落入灰尘、皮屑、纤维碎屑等异物，导致人眼在通过光学成像系统观察显示屏时，异物会成像，产生黑点、黑线、亮点、亮线等显示不良。
发明内容
本申请提供一种光学成像系统及头戴显示装置，可以使显示屏和透镜组之间的异物造成的显示不良不易被人眼察觉到。
本申请实施例一方面提供一种光学成像系统，包括显示屏和透镜组；所述显示屏位于所述透镜组的远离人眼的一侧，所述显示屏包括显示面板和盖板，所述盖板设置在所述显示面板的面向所述透镜组的一侧，所述盖板的厚度满足：
Figure PCTCN2021113421-appb-000001
其中，f’为所述透镜组的等效像方焦距，n为所述盖板的折射率，a为人眼的明视距离。
本申请实施例提供的光学成像系统，通过增大显示屏上的盖板的厚度，使盖板的厚度增加至光学成像系统的焦距的一定比例，以增大落在透镜组和显示屏之间的异物与显示面板之间的距离，使显示面板上的显示图像清晰成像的情况下，盖板表面的异物成像的像距与显示图像的像距较远，呈现虚化效果，无法被人眼清晰捕捉，从而导致黑点、黑线、亮点、亮线等显示不良可以不被察觉到。
在一种可能的实施方式中，a不大于300mm。
明视距离为人眼能够看清物体的最近距离，明视距离的范围不超过300mm，人眼在注视无穷远时无法同时看清距离300mm及以内范围内的物体，因此将明视距离代入上述公式， 可以使盖板表面的异物成像呈现虚化效果。
在一种可能的实施方式中，所述盖板包括覆盖在所述显示面板上的第一盖板和设置在所述第一盖板上的第二盖板，所述第二盖板粘接在所述第一盖板上。
显示屏在生产过程中一般在显示面板表面覆盖有较薄的保护层作为第一盖板，若要增加盖板的厚度，除了在生产过程中直接增加第一盖板的厚度，还可以在显示屏表面增加设置第二盖板，第二盖板可以通过粘接等方式设置在显示屏上，工艺简单容易实现，且成本较低。
在一种可能的实施方式中，所述盖板的厚度小于3.5mm。
盖板的厚度处于小于3.5mm的范围内，以在起到使盖板表面的异物成像的像距与显示图像的像距较远的作用的同时，防止盖板厚度过大对光学成像系统的体积和重量造成较大影响，满足光学成像系统整体的轻薄化设计。
在一种可能的实施方式中，所述盖板由透明的玻璃或塑料制成，所述盖板的折射率处于1.3-1.9的范围内。
显示屏的盖板设置为光学玻璃或光学塑料，不同材料的盖板的折射率和密度不同，在设计盖板的厚度时，选择折射率较小的材质作为盖板，可以使盖板的厚度尽量做薄，以满足光学成像系统整体的轻薄化设计。
在一种可能的实施方式中，所述透镜组的等效像方焦距处于10mm-60mm的范围内。
随着对光学成像系统的体积及成像质量的要求，透镜组的焦距倾向于更小的范围，透镜组的焦距越小，对应的放大倍数越大，则透镜组和显示屏之间的异物导致的显示不良越明显，通过增大盖板厚度来解决该问题的必要性越大。
在一种可能的实施方式中，所述透镜组包括至少一个镜片，所述镜片包括菲涅尔镜片、平凸透镜、双凸透镜、弯月正透镜、平凹透镜、双凹透镜或弯月负透镜。
光学成像系统的透镜组可以设置不同的镜片类型和镜片数量，通过镜片的组合来提高成像质量，满足更多成像需求。
本申请实施例另一方面提供一种头戴显示装置，包括设备主体、穿戴部和安装在所述设备主体内的如上所述的光学成像系统。
头戴显示装置包括设备主体和穿戴部，用户佩戴头戴显示装置时，设备主体位于用户的眼睛的前方，用来为用户的眼睛提供显示画面，穿戴部则用来固定在用户的头部或者耳朵上，实现头戴显示装置的可靠佩戴。光学成像系统中设置在设备主体中，用来实现虚拟画面的显示。
在一种可能的实施方式中，所述头戴显示装置包括虚拟现实眼镜。
头戴显示装置可以为眼镜的形式，此时，设备主体可以包括架设在用户鼻梁上方且位于用户眼睛前方的镜架，穿戴部可以为架设在用户耳朵上的镜腿。
本申请实施例提供一种光学成像系统和头戴显示装置，通过增大显示屏上的盖板的厚度，使盖板的厚度增加至光学成像系统的焦距的一定比例，以增大落在透镜组和显示屏之间的异物与显示面板之间的距离，使显示面板上的显示图像清晰成像的情况下，盖板表面的异物成像的像距与显示图像的像距较远，呈现虚化效果，无法被人眼清晰捕捉，从而导致黑点、黑线、亮点、亮线等显示不良可以不被察觉到。
附图说明
图1为本申请一实施例提供的头戴显示装置的结构示意图；
图2为本申请一实施例提供的头戴显示装置的另一角度的结构示意图；
图3为相关技术提供的光学成像系统的结构示意图；
图4为相关技术提供的光学成像系统的成像原理示意图；
图5为相关技术提供的头戴显示装置的成像示意图；
图6为本申请一实施例提供的光学成像系统的成像原理示意图；
图7为本申请一实施例提供的光学成像系统的物像关系示意图；
图8为本申请一实施例提供的头戴显示装置的成像示意图；
图9为本申请一实施例提供的光学成像系统优化前的结构示意图；
图10为图9提供的光学成像系统在优化后的结构示意图；
图11为本申请又一实施例提供的光学成像系统在优化前的结构示意图；
图12为图11提供的光学成像系统在优化后的结构示意图。
附图标记说明：
100-头戴显示装置；11-设备主体；12-穿戴部；200-光学成像系统；21-显示屏；211-显示面板；212-盖板；212a-第一盖板；212b-第二盖板；22-透镜组；221-第一镜片；222-第二镜片；223-第三镜片；224-第四镜片；225-第五镜片；300-异物。
具体实施方式
图1为本申请一实施例提供的头戴显示装置的结构示意图，图2为本申请一实施例提供的头戴显示装置的另一角度的结构示意图。参考图1和图2所示，本申请实施例提供一种头戴显示装置100，该头戴显示装置100包括设备主体11和穿戴部12，用户佩戴头戴显示装置100时，设备主体11位于用户的眼睛的前方，用来为用户的眼睛提供显示画面，穿戴部12则用来固定在用户的头部或者耳朵上，实现头戴显示装置100的可靠佩戴。
示例性地，头戴显示装置100可以为眼镜的形式，此时，设备主体11可以包括架设在用户鼻梁上方且位于用户眼睛前方的镜架，穿戴部12可以为架设在用户耳朵上的镜腿。头戴显示装置100也可以为头盔等形式，设备主体11可以为罩设在用户眼睛前方的眼罩，穿戴部12可以为罩设在用户头部的头盔。
设备主体11内设置有光学成像系统200，以实现虚拟画面的显示，光学成像系统200的数量可以为两个，分别对应用户的左眼和右眼设置。两个光学成像系统200可以通过交错显示、画面交换或者视差融合的方式，达到立体显像的目的。
图3为相关技术提供的光学成像系统的结构示意图。参考图3所示，光学成像系统200包括显示屏21和透镜组22，显示屏21位于透镜组22的远离人眼的一侧，显示屏21用来显示画面，显示屏21发出的光线经过透镜组22的折射或反射后进入人眼。
显示屏21包括显示面板211和盖板212，显示面板211包括发光层、光学胶层、偏光片等叠层结构，显示面板211整体用来显示，实际上是发光层在发出光线，由于显示面板211整体的厚度小于0.2mm，其内部各层厚度可以忽略，看作是由显示面板211的面向透镜组22的一侧表面发出光线。盖板212盖设在显示面板211上，用来保护显示面板211。
透镜组22可以由至少一个透镜组成，该透镜包括但不限于菲涅尔镜片、平凸透镜、 双凸透镜、弯月正透镜、平凹透镜、双凹透镜、弯月负透镜等类型，多个透镜配合使用，以使显示屏21发出的光线经过一个或多个透镜的折射或反射后，以近似平行光的状态进入人眼。
头戴显示装置100的光学成像系统200的工作原理为，将显示屏21的位置固定，通过透镜组22将显示屏21发出的光线，在一定的像距位置成像给人眼，人眼可以观察到固定像距位置处的图像。
显示屏21与透镜组22之间具有间隙，该间隙至少为0.2mm，用来防止显示屏21和透镜组22之间发生碰撞。显示屏21与透镜组22安装在设备主体11内时，外围设置有密封圈等密封结构，以防止外部环境中的灰尘进入到显示屏21与透镜组22之间的间隙内。但是，在装配过程中进入显示屏21与透镜组22之间的间隙内的灰尘难以完全避免。
相关技术中，头戴显示装置100可以在100级无尘车间内进行组装，静态的100级无尘车间内，空气中的颗粒物的直径大多在1μm以下，可以忽略不计。但是实际生产过程中，工作人员进入车间环境后，不可避免地会有皮肤或者衣物暴露在环境中，导致产生皮屑、纤维碎屑、灰尘等异物，这些异物的直径处于10μm-2000μm之间。异物尺寸较小，装配头戴显示装置100的工作人员难以发现和将其清理干净，因此显示屏21和透镜组22装配后，异物可能会落入显示屏21和透镜组22之间的间隙内，例如粘附在显示屏21上的盖板212表面。
图4为相关技术提供的光学成像系统的成像原理示意图，图5为相关技术提供的头戴显示装置的成像示意图。参考图4和图5所示，盖板212的面向透镜组22的一侧表面上粘附有异物300，此时，经透镜组22进入人眼的光线有两类。第一类为显示面板211发出的光线，例如显示面板211上的点p，第二类为异物300上发出的光线，例如异物300上的点q。
显示面板211上的点p发出的光线经过透镜组22后可以接近平行的光线进入人眼，其虚像p’的像距在1米至无穷远的范围内。盖板212的厚度h’较小时，异物300上的点q，发出的光线经过透镜组22后同样以接近平行的光线进入人眼，其虚像q’的像距在1米至无穷远的范围内。由于显示面板211上的点p和异物300上的点q，距离透镜组22之间的距离相差较小，因此两者虚像p’和q’的位置接近，均处于人眼的可视范围内。
并且，头戴显示装置100内的透镜组22的等效焦距一般处于10mm-100mm范围内，对应的放大倍数处于2.5倍-25倍之间，随着虚拟现实技术的发展，虚拟现实装置中的透镜组22的等效焦距可以缩小至10mm-60mm的范围。对于上述10μm-2000μm的异物300来说，经过透镜组22的放大后，显示的虚像的直径可以达到毫米级甚至厘米级的尺寸范围，其大小足以被用户的眼睛捕捉到。
也就是说，用户佩戴头戴显示装置100时，装配过程中粘附在显示屏21上的极小的皮屑、纤维碎屑、灰尘等异物300，经过光学成像系统200的放大和成像后，会产生黑点、黑线、亮点、亮线等显示不良，会影响到头戴显示装置100的显示效果，导致用户体验不佳。
基于上述描述，本申请实施例提供一种光学成像系统和头戴显示装置，通过增大显示屏上的盖板的厚度，使盖板的厚度增加至光学成像系统的焦距的一定比例，以增大落在透镜组和显示屏之间的异物与显示面板之间的距离，使显示面板上的显示图像清晰成像的情 况下，盖板表面的异物成像的像距与显示图像的像距较远，呈现虚化效果，无法被人眼清晰捕捉，从而导致黑点、黑线、亮点、亮线等显示不良可以不被察觉到。
图6为本申请一实施例提供的光学成像系统的成像原理示意图，参考图6所示，本申请实施例中，光学成像系统200包括显示屏21和透镜组22，显示屏21位于透镜组22的远离人眼的一侧，显示屏21包括显示面板211和盖板212，盖板212连接在显示面板211的面向透镜组22的一侧。
盖板212的远离显示面板211的表面与显示面板211的面向盖板212的表面之间的距离，即盖板212的厚度h(单位mm)，满足以下公式：
Figure PCTCN2021113421-appb-000002
其中，n为盖板212的折射率，f’为光学成像系统200的等效像方焦距(单位mm)，f’为正值，其大小与等效物方焦距的大小相等，a表示人眼的明视距离，范围为不大于300mm。
此时，相比于图4，本申请实施例中的盖板212的厚度h大于相关技术中盖板212的厚度h’，位于盖板212的表面上的异物300与显示面板211的距离增大，在显示面板211上的点p发出的光线清晰成像的情况下，异物300上的点q的虚像被虚化，不容易被人眼察觉到。
以下为盖板212的厚度范围即公式一的推导过程。
图7为本申请一实施例提供的光学成像系统的物像关系示意图。图7中，HH’为光学成像系统200的等效透镜的厚度，B为待成像的物体，B’为B经过成像后的虚像，F为光学成像系统200的等效透镜的焦点。参考图7所示，在具有一定厚度的盖板212的光学成像系统200中，由于盖板300表面上的异物300距离显示面板211的表面较远，物像关系公式为：
Figure PCTCN2021113421-appb-000003
其中，L’为虚像至光学成像系统200的等效透镜的距离，L为显示面板211到光学成像系统200的等效透镜的距离。
参考图6所示，当物面处于显示面板211上时，以显示面板211上的点p为例，定义点p的物距为L1，像距为L1’，对于头戴显示装置100中的光学成像系统200来说，物距L1小于显示面板211与透镜组22的距离，小于60mm，像距L1’即人眼所观察到的显示画面的虚像距，处于1米到无穷远的范围内。因此，L1’远大于L1，上述物像公式可以简化为：
Figure PCTCN2021113421-appb-000004
当物面处于盖板212上时，以异物300上的点q为例，点q的物距为L2，点q的像距为L2’，L2和L1的关系满足以下公式：
Figure PCTCN2021113421-appb-000005
此时，点q对应的物像公式为：
Figure PCTCN2021113421-appb-000006
将公式三和公式四代入到公式五中，可以得到以下公式：
Figure PCTCN2021113421-appb-000007
根据公式六，可以得到h与虚像距L2’、等效像方焦距f’、盖板212的折射率n之间的关系如下：
Figure PCTCN2021113421-appb-000008
在光学成像系统200中，虚像距的倒数代表着视度，1/L2’为点q的虚像距的倒数，代表着盖板212表面的异物300的虚像视度。当人眼观察到的显示画面的成像虚像距为1米至无穷远时，若异物300的点q的虚像视度明显大于显示面板211上点p的虚像视度，异物300的点q的虚像在人的明视距离以内，可以认为人眼无法察觉一定尺寸的该异物300的成像。
其中，人能够看清物体的最近距离称之为明视距离，明视距离a不大于300mm，对于健康的人眼，明视距离在250mm左右，对于近视眼，明视距离短于250mm，对于远视眼，明视距离长于250mm。
将人眼在注视无穷远时无法同时看清在明视距离a处的异物情况代入公式七，即可得到公式一。
选择明视距离a的最大值300mm代入公式一中，即可得到公式八。
Figure PCTCN2021113421-appb-000009
盖板212的厚度h满足公式八时，异物300的点q的虚像与人眼的距离在300mm范围内，由于此时人眼观察到的显示画面的成像虚像距为1米至无穷远，异物300的点q的虚像视度明显大于显示面板211上点p的虚像视度，可以认为人眼无法察觉一定尺寸的该异物300的成像。
不难理解的是，人眼无法察觉距离为300mm的异物的虚像时，同样也无法察觉距离小于300mm的异物的虚像。因此，将明视距离a的最大值300mm代入公式一得到的公式八中，h的范围包含了a小于300mm时对应的h的范围。
图8为本申请一实施例提供的头戴显示装置的成像示意图。参考图8所示，显示面板211上的点p发出的光线经过透镜组22后可以接近平行的光线进入人眼，其虚像p”的像距在1米至无穷远的范围内。盖板212的厚度h满足公式八时，盖板212的表面上的异物300的点q，其虚像q”的像距在小于300mm的范围内。此时异物300的虚像视度明显大于显示面板211的显示画面的虚像视度，且异物300的虚像尺寸较小，可以认为人眼无法察觉。
需要说明的是，盖板212可以为显示屏200生产过程中，附着在显示面板211表面的保护层，此时，盖板212的厚度可以满足公式八，以虚化显示屏200上的异物的成像。在另一种可能的实施方式中，显示屏200已经制作完成后，其自身的第一盖板厚度无法满足公式八，可以在显示屏200上额外增加一层平板材料作为第二盖板，使第二盖板和第一盖板的厚度之和，满足公式八，以虚化显示屏200上的异物的成像。
其中，盖板212的材料包括但不限于玻璃、塑料等透明材料，盖板的折射率可以处于1.3-1.9的范围内。第一盖板覆盖在显示面板211的表面，其可以为显示面板211制作时通过沉积等方式形成的膜层，或者采用光学胶粘接的方式连接在显示面板211上。额外增加第二盖板时，同样可以通过光学胶将第二盖板粘接在第一盖板上，以不影响显示面板211的显示效果。或者，显示面板211具有显示区和位于显示区四周的非显示区，第二盖板和 第一盖板可以通过胶水或背胶粘接，胶水或背胶可以设置在对应于非显示区的区域内，以避免影响到显示区的正常显示。或者，也可以在显示屏和第二盖板的周围设置结构件，以使第二盖板紧贴第一盖板设置。第一盖板和第二盖板可以采用相同的材料制成，也可以采用不同的材料制成，一般地，由于两者的折射率相近，且第一盖板的厚度远小于第二盖板的厚度，因此，在利用上述公式计算需要新增的第二盖板的厚度时，可以忽略掉两者的折射率差别，以第二盖板的折射率代入公式进行计算。
此外，本申请实施例中，盖板212的厚度可以小于3.5mm，以防止盖板212厚度过大对光学成像系统的体积和重量造成较大影响。
本申请实施例提供的光学成像系统，通过增加显示屏内盖板的厚度，可增大显示屏表面的异物与显示面板的距离，使异物的虚像视度大于人眼明视距离代表的视度，从而使异物的虚像与显示画面的虚像的位置相差较远，保证人眼通过光学成像系统观察显示屏时，显示屏表面的异物引起的黑点、黑线、亮点、亮线等显示不良的成像，无法被人眼清晰捕捉。
以下参考更具体的实施例，来描述本申请实施例提供的光学成像系统和头戴显示装置。
图9为本申请一实施例提供的光学成像系统优化前的结构示意图。参考图9所示，光学成像系统200包括显示屏21和透镜组22，显示屏21可以为LCD(Liquid Crystal Display，液晶显示器)，透镜组22可以包括一个镜片，该镜片可以为菲涅尔透镜，镜片两侧的表面分别为S1表面和S2表面，S2表面位于面向显示屏21的一侧，S1表面位于背向显示屏21面向人眼的一侧。透镜组22的等效焦距f在530nm光照下的大小为24.67mm，显示屏21自身的第一盖板212a的厚度较薄，光学成像系统200的各项参数如表1所示。
表1
Figure PCTCN2021113421-appb-000010
对于表1中的参数，需要说明的是，“材料”一栏对应的内容为空气时，“厚度”一栏的数值实际代表的含义是距离，且各项参数均是以各个结构的中心为标准，例如，镜片S1的曲率半径和厚度，指的是镜片S1的中心对应的曲率半径和厚度。根据表1可以得出，设定显示屏21自身的第一盖板212a的厚度为0.2mm，材料为型号H-K9L的玻璃，对应的折射率n＝1.52，镜片的S2表面中心距离第一盖板212a的表面的距离为23.5mm，镜片的中心厚度为5mm，材料为聚甲基丙烯酸甲酯PMMA，光学成像系统200的显示画面的像距大小为1500mm，对应的视度为0.67D。
此时，经过计算机仿真可以得到，第一盖板212a表面中心的异物的虚像距大小为1130mm，对应的视度为0.88D。可见，显示画面的虚像和盖板212a表面异物的虚像距离较近，异物虚像容易被人眼捕捉到，从而影响到显示画面的观看效果。
图10为图9提供的光学成像系统在优化后的结构示意图。参考图10所示，本申请实施例通过在显示屏21上新增第二盖板212b来解决这个问题，新增的第二盖板212b的材 料和折射率与第一盖板212a相同，将f’＝24.67和n＝1.52代入到公式一中，可以得到盖板212的厚度h大于等于2.85mm，新增的第二盖板212b的厚度大于等于2.65mm。此时，光学成像系统200的各项参数如表2所示。
表2
Figure PCTCN2021113421-appb-000011
此时，经过计算机仿真可以得到，盖板212表面中心的异物的虚像距大小为257mm，对应的视度为3.89D。可见，新增第二盖板212b之后，盖板212上附着的异物引起的虚像，需要人眼调节3.89D的视度完成重聚焦，不容易被发现。
图11为本申请又一实施例提供的光学成像系统在优化前的结构示意图。参考图11所示，光学成像系统200包括显示屏21和透镜组22，显示屏21可以为OLED(Organic Light Emitting Diode，有机发光二极管)，透镜组22可以包括依次设置的第一镜片221、第二镜片222、第三镜片223、第四镜片224和第五镜片225，第五镜片225与显示屏21的距离最近，每个镜片均包括S1表面和S2表面，且S2表面位于面向显示屏21的一侧，S1表面位于背向显示屏21面向人眼的一侧。透镜组22的等效焦距f在530nm光照下为21.56mm，显示屏21自身的第一盖板212a的厚度较薄，光学成像系统200的各项参数如表3所示。
表3
Figure PCTCN2021113421-appb-000012
对于表3中的数据，需要说明的是，“材料”一栏对应的内容为空气时，“厚度”一栏的数值实际代表的含义是距离，且各项参数均是以各个结构的中心为标准，例如，第一镜片S1的曲率半径和厚度，指的是镜片S1的中心对应的曲率半径和厚度。根据表3可以得出，设定显示屏21自身的第一盖板212a的厚度为0.7mm，材料为H-K9L的玻璃，对应的折 射率n＝1.52，第五镜片225的S2表面距离第一盖板212a的表面的距离为1.46mm，镜片的材料APL、OKP、E48R分别为不同型号的光学塑料，光学成像系统200的显示画面的像距为无穷远，对应的视度为0。
此时，经过计算机仿真可以得到，第一盖板212a表面中心的异物的虚像距大小为972mm，对应的视度为1.03D。可见，显示画面的虚像和第一盖板212a表面异物的虚像距离较近，异物虚像容易被人眼捕捉到，从而影响到显示画面的观看效果。
图12为图11提供的光学成像系统在优化后的结构示意图。参考图12所示，本申请实施例通过在显示屏21上新增第二盖板212b来解决这个问题，新增的第二盖板212b的材料和折射率与第一盖板212a相同，将f’＝21.56和n＝1.52代入到公式一中，可以得到盖板212的厚度h大于等于2.17mm，新增的第二盖板212b的厚度大于等于1.97mm。此时，光学成像系统200的各项参数如表4所示。
表4
Figure PCTCN2021113421-appb-000013
此时，经过计算机仿真可以得到，盖板212表面中心异物的虚像距大小为298mm，对应的视度为3.36D。可见，新增第二盖板212b之后，盖板212上附着的异物引起的虚像，需要人眼调节3.36D的视度完成重聚焦，不容易被发现。
本申请实施例中，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”应作广义理解，例如，可以是固定连接，也可以是通过中间媒介间接相连，可以是两个元件内部的连通或者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申请实施例中的具体含义。本申请实施例的说明书和权利要求书及上述附图中的术语“第一”、“第二”、“第三”等是用于区别类似的对象，而不必用于描述特定的顺序或先后次序。
此外，术语“包括”和“具有”以及他们的任何变形，意图在于覆盖不排他的包含，例如，包含了一系列步骤或单元的过程、方法、系统、产品或设备不必限于清楚地列出的那些步骤或单元，而是可包括没有清楚地列出的或对于这些过程、方法、产品或设备固有的其它步骤或单元。
最后应说明的是：以上各实施例仅用以说明本申请实施例的技术方案，而非对其限制；尽管参照前述各实施例对本申请实施例进行了详细的说明，本领域的普通技术人员应当理解：其依然可以对前述各实施例所记载的技术方案进行修改，或者对其中部分或者全部技术特征进行等同替换；而这些修改或者替换，并不使相应技术方案的本质脱离本申请实施例技术方案的范围。

Claims (9)

  1. 一种光学成像系统，其特征在于，包括显示屏和透镜组；
    所述显示屏位于所述透镜组的远离人眼的一侧，所述显示屏包括显示面板和盖板，所述盖板设置在所述显示面板的面向所述透镜组的一侧，所述盖板的厚度满足：
    Figure PCTCN2021113421-appb-100001
    其中，f’为所述透镜组的等效像方焦距，n为所述盖板的折射率，a为人眼的明视距离。
  2. 根据权利要求1所述的光学成像系统，其特征在于，a不大于300mm。
  3. 根据权利要求1或2所述的光学成像系统，其特征在于，所述盖板包括覆盖在所述显示面板上的第一盖板和设置在所述第一盖板上的第二盖板，所述第二盖板粘接在所述第一盖板上。
  4. 根据权利要求1-3任一项所述的光学成像系统，其特征在于，所述盖板的厚度小于3.5mm。
  5. 根据权利要求1-4任一项所述的光学成像系统，其特征在于，所述盖板由透明的玻璃或塑料制成，所述盖板的折射率处于1.3-1.9的范围内。
  6. 根据权利要求1-5任一项所述的光学成像系统，其特征在于，所述透镜组的等效像方焦距处于10mm-60mm的范围内。
  7. 根据权利要求1-6任一项所述的光学成像系统，其特征在于，所述透镜组包括至少一个镜片，所述镜片包括菲涅尔镜片、平凸透镜、双凸透镜、弯月正透镜、平凹透镜、双凹透镜或弯月负透镜。
  8. 一种头戴显示装置，其特征在于，包括设备主体、穿戴部和安装在所述设备主体内的如权利要求1-7任一项所述的光学成像系统。
  9. 根据权利要求8所述的头戴显示装置，其特征在于，所述头戴显示装置包括虚拟现实眼镜。
PCT/CN2021/113421 2020-09-11 2021-08-19 光学成像系统及头戴显示装置 WO2022052769A1 (zh)

Priority Applications (3)

Application Number Priority Date Filing Date Title
JP2023515872A JP2023540387A (ja) 2020-09-11 2021-08-19 光学結像系及びヘッドマウント型表示装置
US18/044,749 US20230367122A1 (en) 2020-09-11 2021-08-19 Optical imaging system and head-mounted display apparatus
EP21865825.0A EP4198609A4 (en) 2020-09-11 2021-08-19 OPTICAL IMAGING SYSTEM AND HEAD-MOUNTED DISPLAY DEVICE

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202010955672.3A CN114167607A (zh) 2020-09-11 2020-09-11 光学成像系统及头戴显示装置
CN202010955672.3 2020-09-11

Publications (1)

Publication Number Publication Date
WO2022052769A1 true WO2022052769A1 (zh) 2022-03-17

Family

ID=80475410

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2021/113421 WO2022052769A1 (zh) 2020-09-11 2021-08-19 光学成像系统及头戴显示装置

Country Status (5)

Country Link
US (1) US20230367122A1 (zh)
EP (1) EP4198609A4 (zh)
JP (1) JP2023540387A (zh)
CN (1) CN114167607A (zh)
WO (1) WO2022052769A1 (zh)

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB392021A (en) * 1931-09-15 1933-05-11 Rca Corp Improvements in or relating to photographic sound records and to methods of reducingground noise during reproduction of sound from such records
US5508834A (en) * 1993-03-04 1996-04-16 Sony Corporation Liquid crystal display device having polarizers and microlens arrays attached to transparent cover members
US5742421A (en) * 1996-03-01 1998-04-21 Reflection Technology, Inc. Split lens video display system
US5757443A (en) * 1995-10-13 1998-05-26 Sony Corporation Transmission-type display device with a heat-dissipating glass plate external to at least one liquid crystal substrate
JP2014157307A (ja) * 2013-02-18 2014-08-28 Seiko Epson Corp 表示装置及び電子機器
US20150061975A1 (en) * 2013-09-03 2015-03-05 Seiko Epson Corporation Virtual image display apparatus
CN205003365U (zh) * 2015-09-07 2016-01-27 易志根 一种虚拟显示装置
CN110579880A (zh) * 2019-09-29 2019-12-17 Oppo广东移动通信有限公司 一种近眼显示光学系统及近眼显示装置
CN110927976A (zh) * 2019-12-25 2020-03-27 上海视欧光电科技有限公司 一种头戴显示光学模组及设备
US20210132397A1 (en) * 2019-11-03 2021-05-06 Facebook Technologies, Llc Head-mounted display assemblies and related methods for interpupillary distance adjustments

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP6255983B2 (ja) * 2013-12-25 2018-01-10 セイコーエプソン株式会社 虚像表示装置
KR102328689B1 (ko) * 2014-01-09 2021-11-22 삼성전자주식회사 착용식 디스플레이 장치

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB392021A (en) * 1931-09-15 1933-05-11 Rca Corp Improvements in or relating to photographic sound records and to methods of reducingground noise during reproduction of sound from such records
US5508834A (en) * 1993-03-04 1996-04-16 Sony Corporation Liquid crystal display device having polarizers and microlens arrays attached to transparent cover members
US5757443A (en) * 1995-10-13 1998-05-26 Sony Corporation Transmission-type display device with a heat-dissipating glass plate external to at least one liquid crystal substrate
US5742421A (en) * 1996-03-01 1998-04-21 Reflection Technology, Inc. Split lens video display system
JP2014157307A (ja) * 2013-02-18 2014-08-28 Seiko Epson Corp 表示装置及び電子機器
US20150061975A1 (en) * 2013-09-03 2015-03-05 Seiko Epson Corporation Virtual image display apparatus
CN205003365U (zh) * 2015-09-07 2016-01-27 易志根 一种虚拟显示装置
CN110579880A (zh) * 2019-09-29 2019-12-17 Oppo广东移动通信有限公司 一种近眼显示光学系统及近眼显示装置
US20210132397A1 (en) * 2019-11-03 2021-05-06 Facebook Technologies, Llc Head-mounted display assemblies and related methods for interpupillary distance adjustments
CN110927976A (zh) * 2019-12-25 2020-03-27 上海视欧光电科技有限公司 一种头戴显示光学模组及设备

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP4198609A4

Also Published As

Publication number Publication date
EP4198609A4 (en) 2024-02-21
JP2023540387A (ja) 2023-09-22
US20230367122A1 (en) 2023-11-16
CN114167607A (zh) 2022-03-11
EP4198609A1 (en) 2023-06-21

Similar Documents

Publication Publication Date Title
US12111471B2 (en) Free-form prism-lens group and near-eye display apparatus
TWI481901B (zh) 頭戴式顯示裝置
JP3199148U (ja) ヘッドマウントディスプレイ及びその光学レンズ
US10620438B2 (en) Head-borne viewing system comprising crossed optics
CN107111132A (zh) 通过超精细结构保护的紧凑型头戴式显示系统
CN104536129A (zh) 一种微显示目镜、头戴目镜系统和头戴可视设备
CN106908953A (zh) 一种集成视力矫正的双目近眼显示装置
WO2021139725A1 (zh) 近眼显示装置
WO2019149176A1 (zh) 目镜、眼镜、头盔式显示器和vr系统
TWM585357U (zh) 實現空中懸浮顯示的光學系統
CN207833115U (zh) Ar显示设备
US10558041B2 (en) Virtual reality image system with high definition
JPWO2019087996A1 (ja) 網膜投影装置、網膜投影システム
EP2381291A1 (en) Vision correction lens assembly for viewing three-dimensional (3D) images
JP7194470B2 (ja) 広視野角・高画質接眼レンズ光学システム及び設備
CN205374869U (zh) 一种目镜
WO2022052769A1 (zh) 光学成像系统及头戴显示装置
CN109425986A (zh) 头戴式显示装置及成像镜头
US11054646B1 (en) Head-mounted display device with Fresnel lenses
JP7471453B2 (ja) ディスプレイに表示されたコンテンツを投影するための方法及び機器
TW201918747A (zh) 虛實影像整合裝置
JPWO2017109857A1 (ja) 接眼投影光学装置
TWI446084B (zh) 電子觀景窗
WO2023092421A1 (zh) 光学系统及vr显示设备
JP2007334185A (ja) 眼鏡型映像表示装置

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: 21865825

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2023515872

Country of ref document: JP

Kind code of ref document: A

ENP Entry into the national phase

Ref document number: 2021865825

Country of ref document: EP

Effective date: 20230316

NENP Non-entry into the national phase

Ref country code: DE