Bifocal plane visual optical system and display device
The dual-focus ophthalmic system addresses the need for adjustable virtual image distance in near-eye displays by combining shared optical components to enhance visual training and eye health, optimizing image quality and reducing device size and power consumption.
Patent Information
- Application Number
- CN202421906879.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-07
- Publication Date
- 2025-07-15
- Estimated Expiration
- 2034-08-07
AI Technical Summary
Existing near-eye display devices cannot meet the needs of myopia or hyperopia users, and lack vision adjustment functions, so they cannot adapt to different vision needs, especially in specific application scenarios such as visual training.
The bifocal surface visual optical system is adopted, and two focal surfaces with different positions are formed through the first and second display optical paths, and the Birdbath optical system and the eyepiece optical system are combined with a planar spectroscope, a first lens and a concave spectroscope, to add the first lens to simplify the design and optimize the imaging effect, and to improve the light energy utilization rate with polarization performance.
The vision adjustment function is realized, adapted to different vision needs, simplified optical system design, reduced volume, and improved imaging quality and light energy utilization, and is suitable for vision training and adjustment of myopia or hyperopia users.
Smart Images
Figure CN223108155U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a dual - focal - plane visual optical system and also relates to a display device, belonging to the field of display technology. Background Art
[0002] In recent years, with the development of virtual reality (VR) and augmented reality (AR) technologies, near - eye display devices for VR or AR have shown great development potential.
[0003] A near - eye display device can magnify the image of an image source and present it in front of the user's eyes. For a large number of myopic or hyperopic users, a near - eye display device with a virtual image located at a fixed position cannot meet the needs of users. At the same time, for certain specific application scenarios, such as in visual training and other requirements, users need to adjust the distance of the virtual image according to the purpose to achieve the adjustment of visual acuity.
[0004] In addition, children and adolescents are in the growth and development period and the peak period of eye use. Helping them establish good eye - using habits, conducting scientific physical exercises and training on the eyes and visual system, enhancing the eye adjustment ability, helps to prevent and control myopia, repair amblyopia, improve the level of uncorrected visual acuity health, and reduce the dependence on vision correction means such as glasses and surgery. Therefore, a display device with a visual acuity adjustment function is increasingly needed by the vast user group.
[0005] A dual - focal - plane display optical system can exercise the eye function by regularly changing the depth of focus, fully mobilize the potential of the eyes, relieve visual fatigue, improve the adjustment speed, increase the adjustment amplitude, and effectively improve adjustment lag, insufficient adjustment function, etc. Summary of the Utility Model
[0006] The technical problem to be solved by the utility model is to provide a dual - focal - plane visual optical system.
[0007] The technical problem to be solved by the utility model is to simultaneously provide a display device.
[0008] In order to achieve the above - mentioned technical purpose, the utility model adopts the following technical solutions:
[0009] A dual - focal - plane visual optical system includes a first display optical path and a second display optical path; wherein,
[0010] The first display optical path includes a planar beam splitter, a first lens, a concave beam splitter, and a first lens group arranged along the visual axis direction from the human eye to the first image source; the surface of the first lens away from the human eye is convex and coated with a beam splitting film to form the concave beam splitter; the light emitted from the first image source passes through the first lens group, the concave beam splitter, the first lens, and the planar beam splitter in sequence and then forms an image on the human eye; the first display optical path forms a first focal plane;
[0011] The second display optical path includes the planar beam splitter, the first lens, the concave beam splitter, and a second lens group arranged from the human eye to the second image source; the first display optical path and the second display optical path share the planar beam splitter, the first lens, and the concave beam splitter; the light emitted from the second image source passes through the second lens group, is reflected by the planar beam splitter, then passes through the first lens and is reflected by the concave beam splitter, and then passes through the first lens and the planar beam splitter in sequence to form an image on the human eye; the second display optical path forms a second focal plane;
[0012] The positions of the first focal plane and the second focal plane are different.
[0013] Preferably, one of the focal planes corresponds to a diopter of -6D to -0D, and the other focal plane corresponds to a diopter of +0D to +5D; the positions of the first focal plane and / or the second focal plane are adjustable.
[0014] Preferably, the first lens is a positive lens, and the surface of the first lens facing the human eye is concave, convex, or planar.
[0015] Preferably, the first lens group is a positive focal power lens group.
[0016] Preferably, the first lens group includes a plurality of positive lenses and a positive-negative doublet lens, and the positive-negative doublet lens is close to the image source side.
[0017] Preferably, the outer surfaces on both sides of the positive-negative doublet lens are concave towards the image source and have the same radius of curvature.
[0018] Preferably, the transmission-reflection splitting ratio of the beam splitting film of the concave beam splitter is less than 1.
[0019] Preferably, the exit pupil distances of the first display optical path and the second display optical path range from 30mm to 50mm.
[0020] Preferably, the second display optical path uses the polarization property of light to improve the light energy utilization rate entering the human eye.
[0021] A display device includes the above-mentioned bifocal visual optical system, as well as a first microdisplay and a second microdisplay, which respectively provide image sources to a first display optical path and a second display optical path.
[0022] The bifocal visual optical system provided by the present utility model combines a Birdbath optical system and an eyepiece optical system together by sharing a planar beam splitter, a first lens, and a concave beam splitter to form two focal planes with different positions in front of the human eye; by disposing a concave mirror on the surface of the first lens away from the human eye side and adding the first lens in the shared optical path, not only the design of the eyepiece system is simplified, the volume of the entire bifocal visual optical system is reduced, but also the imaging effect of the BB optical path is optimized. Description of the Drawings
[0023] Figure 1 is the optical path diagram of the optical system provided by the present utility model;
[0024] Figure 2 is the optical path schematic diagram of the first display optical path;
[0025] Figure 3 is the schematic diagram of the lens group of the first display optical path;
[0026] Figure 4 is the second display optical path diagram with zero diopter;
[0027] Figure 5 is the second display optical path diagram with +2D diopter;
[0028] Figure 6 is the optical path diagram of the optical system with a polarization device. Detailed Embodiments
[0029] The following provides a detailed description of exemplary embodiments of the present utility model to explain the present utility model, and its examples are shown in the drawings, where the same reference numerals always represent the same components. Unless otherwise clearly stated, those skilled in the art should understand that the so-called front and back are only relative descriptions and do not serve as absolute limitations of being actually in front or behind. Moreover, terms such as first and second should only be understood as differentiating different components and do not have a limiting effect on the order. And in different embodiments, the component structures that are also called the first part may also be different.
[0030] The present utility model will be further described in detail below in conjunction with the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present utility model and are not intended to limit the present utility model. Additionally, it should be noted that for the sake of description, only parts related to the present utility model rather than all structures are shown in the drawings.
[0031] As Figure 1As shown in the figure, the display device provided by the present utility model includes a bifocal visual optical system and two micro displays. The bifocal visual optical system includes a first display optical path and a second display optical path; the first display optical path is an eyepiece optical system, and the second display optical path is a Birdbath type optical system; the focal plane positions of the first display optical path and the second display optical path may be the same or different. The two micro displays respectively provide image sources for the first display optical path and the second display optical path, and the two micro displays can perform axial movement along the optical axis to achieve focal plane position adjustment. The exit pupil distances and exit pupil diameters of the two display optical paths are relatively large, the exit pupil distance ranges from 30 to 50 mm, and the field of view angle ranges from 40 to 50 degrees.
[0032] As Figure 2 shown in the figure, the first display optical path includes a planar beam splitter 12, a first lens 13, a concave beam splitter 132, and a first lens group 14 that are coaxially arranged along the visual axis from the human eye 11 to the first micro display 15. Among them, the planar beam splitter 12 is coated with a beam splitting film or a polarization beam splitting film; the first lens 13 is a meniscus positive lens or a biconvex positive lens, the surface 132 of the first lens 13 facing the human eye is concave or convex, and the surface 132 of the first lens 13 facing the micro display is convex and coated with a beam splitting film to form a concave beam splitter 132; the first lens group 14 includes multiple lenses and constitutes a positive optical power eyepiece group. The image light 16 emitted by the first micro display 15 passes through the first lens group 14, the concave beam splitter 132, the first lens 13, and the planar beam splitter 12 in sequence and then reaches the exit pupil plane 11 and enters the human eye. During this process, the first image light is split twice, and only part of the light is used for human eye imaging. At this time, a virtual image is formed at the first focal plane position. For example, the virtual image of the first display optical path is presented in an approximately infinite distance in accordance with the natural visual state. By adjusting the distance between the first micro display 15 and the first lens group 14, the position of the first focal plane can be adjusted.
[0033] As Figure 2 and Figure 3 shown in the figure, in this embodiment, the first lens group 14 includes 4 lenses, which are lenses 14A - 14D arranged in sequence along the visual axis from the human eye to the first micro display 15. Among them, the side facing the human eye is the front, and the side facing the first micro display 15 is the rear. The lens 14A is an approximately plano-convex lens, the surface facing the human eye is convex, and the surface facing the first micro display 15 is approximately planar; the lens 14B is a biconvex lens; the lens 14C is a biconvex lens, the lens 14D is a biconcave lens, and the lens 14C and the lens 14D are positive-negative doublet lenses. Preferably, the curvature radii of the outer surfaces on both sides of the lens 14C and the lens 14D are the same. The first lens group 14 has a positive optical power. Table 1 exemplarily gives the optical structure parameters of the first display optical path of the optical system in Embodiment 1 of the present utility model.
[0034] Optical structure parameters of the first display optical path in Table 1
[0035]
[0036]
[0037] As Figure 4 shown, the second display optical path includes a planar beam splitter 12, a first lens 13, a concave beam splitter 132, a second lens group 17, and a second micro display 18. The first display optical path and the second display optical path share the planar beam splitter 12, the first lens 13, and the concave beam splitter 132. The second lens group 17 is preferably a positive-negative cemented lens to correct chromatic aberration. The second micro display 18 can be a display or a mask with backlight. The light emitted by the second micro display 18 reaches the planar beam splitter 12 after being refracted by the second lens group 17, and then is reflected by the planar beam splitter 12 and enters the first lens 13, and is reflected by the rear surface of the first lens 13 (i.e., the concave beam splitter 132); the light reflected by the concave beam splitter 132 passes through the first lens 13 and passes through the planar beam splitter 12 to reach the human eye for imaging. In this process, the second image light is split three times, and only part of the light is used for human eye imaging. The second display optical path has a second focal plane, and the second image light forms an image at the second focal plane position.
[0038] The position of the second focal plane and the position of the first focal plane can be the same or different; when the positions of the two focal planes are the same, more abundant picture content can be displayed on the same focal plane; when the positions of the two focal planes are different, the two focal planes can be alternately displayed, and the human eye can switch between the two focal planes, or one focal plane can be normally imaged while the other focal plane is out-of-focus imaged to achieve vision training. When the positions of the two focal planes are different, one of the focal planes corresponds to a diopter of -6D to -0D, and the other focal plane corresponds to a diopter of +0D to +5D. The corresponding diopter range of the display focal plane of the first display optical path is preferably negative, and the corresponding diopter range of the display focal plane of the second display optical path is preferably positive.
[0039] Figure 4 and Figure 5 are the optical path structure diagrams of the second display optical path for imaging at 0D diopter and +2D diopter respectively. Figure 4 is the optical path diagram of the second display optical path in the 0 diopter state. The image light 19 emitted by the micro display device 18 at a variable position( Figure 1 and Figure 4As shown by the solid line in [figure reference], after passing through the plane beam splitter 12 for the first time through the doublet lens group 17 and entering the first lens 13, the light is reflected on the concave beam splitter 132 according to a predetermined splitting ratio, passes through the first lens 13 for the second time, and then passes through the plane beam splitter 12. Finally, the transmitted light reaches the exit pupil plane 11 and enters the human eye for imaging. At this time, the virtual image of the second focal plane is presented at approximately infinity in the natural vision state, and the diopter is 0D. In actual use, it is preferred that the two focal planes are not both at the position with a diopter of 0D at the same time.
[0040] Figure 5 is the optical path diagram when the second display optical path is in the +2D diopter state. Compared with Figure 4 In comparison, Figure 5 in [figure reference], only the position of the micro display device 18 is moved approximately 2 mm in the direction away from the second lens group along the light direction (moved to the position 181 shown in the figure), and the rest of the optical structure remains unchanged. The image light 191 ( Figure 1 and Figure 5 shown by the dashed line in [figure reference]) is a converging beam when entering the human eye pupil, generating a positive diopter, and the imaging focal plane of the virtual display image in the second display optical path can be moved. The selectable second lens group 17 can be implemented as a doublet lens, a liquid lens, a relay lens group, or other forms.
[0041] Specifically, both the plane beam splitter 12 and the concave beam splitter 132 have beam splitting film layers with a predetermined transmission and reflection splitting ratio, such as a semi-transparent and semi-reflective film or other beam splitting films with different transmission and reflection ratios, so that the image light can enter the human eye as effectively as possible after being split by the plane beam splitter 12 and the concave beam splitter 132. In this example, the image light 16 of the first display optical path passes through the concave beam splitter 132 and the plane beam splitter 12 in sequence and then reaches the exit pupil plane 11, while the image light 19 of the second display optical path passes through the plane beam splitter 12 for the first reflection splitting, the concave beam splitter 132 for reflection splitting, and then passes through the plane beam splitter 12 for transmission splitting for the second time. Since the image light 19 of the second reflection optical path passes through the plane beam splitter 12 twice, the energy utilization rate of the second display optical path is less than that of the first display optical path. The light efficiency of the first display optical path and the second display optical path can be adjusted to be the same by modulating the splitting efficiency of the concave beam splitter 132. At this time, the transmission and reflection splitting ratio of the concave beam splitter is less than 1. For example, (transmission: reflection) = 1:2, that is, the transmittance is 33% and the reflectance is 67%.
[0042] Furthermore, in the above embodiment, if a polarization-type image light providing element is used, such as an LCD micro display device or an OLED micro display combined with a polarizer combination device, the beam splitting film of the plane beam splitter 12 can have the characteristics of polarization beam splitting, so as to improve the utilization rate of the image light reflected onto the concave beam splitter 132, reduce beam splitting loss, and eliminate stray light. As Figure 6As shown in the figure, the second display optical path utilizes the polarization property of light. Specifically, a polarization beam splitting film layer is coated on the planar beam splitter 12 to form a polarization planar beam splitter 12. The quarter-wave plate 124 is disposed between the planar beam splitter 12 and the concave beam splitter 132. Preferably, the quarter-wave plate 124 is disposed on the surface of the first lens 13. A polarization polarizer 122 and a quarter-wave plate 123 are added in front of the OLED micro display device 18. The light beam emitted by the second display optical path passes through the polarization polarizer 122 and the quarter-wave plate 123 to convert the natural light emitted by the light source 18 into circularly polarized light. After passing through the quarter-wave plate 124 before the polarization beam splitter 12, the circularly polarized image light 19 is converted into the first linearly polarized light. After being reflected by the polarization planar beam splitter 12 and then reflected by the concave beam splitter 132 and reaching the polarization planar beam splitter 12 again, the first linearly polarized light passes through the quarter-wave plate 124 twice, and the polarization phase of the image light 19 changes to become the second linearly polarized light. The polarization directions of the second linearly polarized light and the first linearly polarized light are perpendicular. When the image light 19 passes through the polarization planar beam splitter 12 for the second time, it is transmitted. The image light 19 after polarization conversion only suffers light energy loss at the polarization polarizer 122 and the concave beam splitter 132, and the light splitting can be approximated as 100% each time when passing through the polarization planar beam splitter 12 twice, improving the light energy utilization rate entering the human eye.
[0043] In this embodiment, compared with the existing commercial solutions, the use of polarized light and polarization devices can increase the light energy utilization rate by more than 1 time, improve the brightness of the image light, reduce the power consumption of the micro display, and reduce the heat generation of the overall system. At the same time, when stray light from the outside is incident on the planar beam splitter 12, some of the polarized light in the stray light will pass through the polarization planar beam splitter 12, and only part of the stray light is reflected into the exit pupil plane 11 and enters the human eye, which can reduce the light effect of the stray light, improve the overall image contrast, and reduce the interference of external light.
[0044] In this embodiment, both the lens group 14 of the first display optical path and the lens group 17 of the second display optical path adopt spherical lens group designs. It can be understood that in the present invention, the lens group 14 of the first display optical path and the lens group 17 of the second display optical path can also adopt aspherical or free-form surfaces for design, increasing the degree of freedom of the system, reducing the difficulty of aberration correction, improving the imaging quality of the system, reducing the volume of the overall system, and the second lens group is not limited to the structure form of double-glue.
[0045] Table 2 exemplarily gives the optical structure parameters of the second display optical path of the optical system in Embodiment 1 of the present invention.
[0046] Table 2 Optical Structure Parameters of the Second Display Optical Path
[0047]
[0048] Therefore, the dual-focus binocular optical system provided by the present utility model enables the wearer to see virtual images formed by two different image sources through the first display system and the second display system respectively, which are located at different positions in front of the human eyes. By adjusting the positions of the two focal planes, the human eye can be switched between the two focal planes.
[0049] In summary, the dual-focus binocular optical system provided by the present utility model combines the Birdbath optical system and the eyepiece optical system together by sharing a planar beam splitter, a first lens and a concave beam splitter, and forms two focal planes with different positions in front of the human eyes; by arranging the concave mirror on the rear surface of the first lens and adding the first lens in the common optical path, not only the design of the eyepiece system is simplified, but also the imaging effect of the BB optical path is optimized. The human eye can be switched between the two focal planes, so that the human eye can be exercised for vision prevention and control. Moreover, the above dual-focus binocular optical system can also have a diopter adjustment function to meet the usage requirements of different diopter groups.
[0050] The above has made a detailed description of a dual-focus binocular optical system and a display device provided by the present utility model. For those of ordinary skill in the art, any obvious modification made to it without departing from the substantial content of the present utility model will constitute an infringement of the patent right of the present utility model and will bear corresponding legal responsibilities.
Claims
1. A bifocal binocular optical system, characterized in that Comprising a first display optical path and a second display optical path; wherein, The first display optical path includes a planar beam splitter, a first lens, a concave beam splitter, and a first lens group arranged along the optical axis direction from the human eye to the first image source; the first lens is a positive lens, the surface of the first lens facing the human eye side is concave, convex or planar, the surface of the first lens away from the human eye side is convex and coated with a beam splitting film to form the concave beam splitter; the first lens group is composed of multiple positive lenses and a positive-negative doublet lens, and the positive-negative doublet lens is arranged close to the first image source; the light emitted by the first image source passes through the first lens group, the concave beam splitter, the first lens, and the planar beam splitter in sequence and is refracted to form an image on the human eye; the first display optical path forms a first focal plane; The second display optical path includes the planar beam splitter, the first lens, the concave beam splitter, and a second lens group arranged from the human eye to the second image source; the first display optical path and the second display optical path share the planar beam splitter, the first lens, and the concave beam splitter; the light emitted by the second image source is refracted by the second lens group, reflected by the planar beam splitter, then passes through the first lens and is reflected by the concave beam splitter, and then passes through the first lens and the planar beam splitter in sequence to form an image on the human eye; the second display optical path forms a second focal plane; The positions of the first focal plane and the second focal plane are different.
2. The bifocal binocular optical system according to claim 1, wherein: One of the focal planes corresponds to a diopter of -6D to -0D, and the other focal plane corresponds to a diopter of +0D to +5D; the position of the first focal plane and / or the second focal plane is adjustable.
3. The bifocal binocular optical system according to claim 1, wherein: The first lens group is a positive focal power lens group.
4. The bifocal binocular optical system according to claim 1, wherein: The outer surfaces on both sides of the positive-negative doublet lens are concave towards the image source and have the same radius of curvature.
5. The bifocal binocular optical system according to claim 1, wherein: The transmission-reflection beam splitting ratio of the beam splitting film of the concave beam splitter is less than 1.
6. The bifocal binocular optical system according to claim 1, wherein: The exit pupil distance range of the first display optical path and the second display optical path is 30mm to 50mm.
7. The bifocal binocular optical system according to claim 1, wherein: The second display optical path utilizes the polarization property of light to improve the light energy utilization rate entering the human eye.
8. A display device, characterized in that: Comprising the bifocal binocular optical system according to any one of claims 1-7, and a first micro display and a second micro display.