Optical system capable of adjusting display and AR (Augmented Reality) equipment

Abstract

The invention discloses an optical system capable of adjusting display and AR (Augmented Reality) equipment. The optical system comprises a first projection module, a second projection module, a polarization element, a semi-transparent and semi-reflective element and a receiving end, the polarization element is obliquely arranged relative to the first projection module, the second projection module and the receiving end are respectively arranged at two sides of the polarization element, the first projection module comprises a display and a doublet lens, and the doublet lens comprises a first lens and a second lens; the second projection module comprises a third lens, a fourth lens, a fifth lens and a protection element; the semi-transparent and semi-reflective element is attached to the face, close to the polarization element, of the third lens. The distance between the doublet lens and the polarization element is D1, the distance between the doublet lens and the display is D2, the distance between the fourth lens and the fifth lens is D3, and the following conditions are satisfied: 9.465 mm < = D1 < = 13.485 mm, 0.045 mm < = D2 < = 1.323 mm, and 0.199 mm < = D3 < = 0.581 mm. Compared with the prior art, the imaging quality can be improved, the function of adjusting the diopter of the double optical paths is achieved, fatigue and dizziness of eyes of a user are relieved, and the use experience of the user is improved.

Description

Technical Field

[0001] The present invention relates to the field of projection display technology, and in particular to an optical system and AR equipment capable of adjusting display. Background Art

[0002] With the rapid development of optical technology, users have higher and higher requirements for the functions and user experience of AR devices. The reasons that affect the user experience of AR devices mainly involve the optical system in AR devices. The optical system of existing AR devices usually adopts bi rdbath optical display technology, and existing AR devices usually cannot adjust the diopter of the real optical path and the virtual optical path at the same time. Instead, they use magnetic myopia lenses for auxiliary adjustment. This method will increase additional costs and also affect the user's wearing comfort to a certain extent.

[0003] In view of this, it is necessary to provide an optical system and AR device with adjustable display to solve the above problems. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention provides an optical system and AR device with adjustable display, which can effectively relieve the fatigue and dizziness of users when observing real images and virtual images, effectively correct the aberration of the system, improve the imaging quality, and improve the user's experience and comfort.

[0005] To achieve the above-mentioned purpose, the first aspect of the present invention provides an optical system with adjustable display, which includes a first projection module, a second projection module, a polarizing element, a semi-transparent and semi-reflective element and a receiving end; the polarizing element is arranged obliquely relative to the first projection module, the second projection module and the receiving end are respectively arranged on both sides of the polarizing element, the first projection module includes a display and a double-glued lens arranged between the display and the polarizing element, the double-glued lens includes a first lens and a second lens arranged in sequence in a direction away from the display; the second projection module includes a third lens, a fourth lens, a fifth lens and a protective element arranged in sequence in a direction away from the polarizing element; the semi-transparent and semi-reflective element is attached to a surface of the third lens close to the polarizing element; the distance between the double-glued lens and the polarizing element is D1, the distance between the double-glued lens and the display is D2, the distance between the fourth lens and the fifth lens is D3, and the following conditions are satisfied: 9.465mm°≤D1≤13.485mm, 0.045mm≤D2≤1.323mm, 0.199mm≤D3≤0.581mm.

[0006] In a preferred embodiment, the effective focal length of the first lens is F1, the effective focal length of the second lens is F2, the effective focal length of the first projection module is F3, and the following conditions are satisfied: 0.740≤F1 / F3≤0.828, 1.176≤F2 / F3≤1.430.

[0007] In a preferred embodiment, the refractive indices of the first lens and the second lens under D light are N1 and N2 respectively, the Abel numbers of the first lens and the second lens under D light are V1 and V2 respectively, and satisfy: 1.68≤N1≤1.76, 1.55≤N2≤1.65, 52≤V1≤75, 24≤V2≤35.

[0008] In a preferred embodiment, the curvature radius of a side of the second lens close to the polarizing element is R1, the curvature radius of the bonding surface of the first lens and the second lens is R2, and the curvature radius of a side of the first lens close to the display is R3, and the following conditions are satisfied: 25mm≤R1≤40mm, -30mm≤R2≤-18mm, -13mm≤R3≤-20mm.

[0009] In a preferred embodiment, the half horizontal field of view of the first projection module is HFOV, the half vertical field of view of the first projection module is VFOV, and the following conditions are satisfied: 19°≤HFOV≤23°, 12°≤VFOV≤14°.

[0010] In a preferred embodiment, the effective focal length of the third lens is F4, the effective focal length of the fourth lens is F5, the effective focal length of the fifth lens is F6, the effective focal length of the second projection module is F7, and the following conditions are satisfied: -0.186≤F4 / F7≤0.241, 0.950≤F5 / F7≤1.340, 0.535≤F6 / F7≤1.219.

[0011] In a preferred embodiment, the refractive indices of the third lens, the fourth lens and the fifth lens under D light are N3, N4 and N5 respectively, and the Abel numbers of the third lens, the fourth lens and the fifth lens under D light are V3, V4 and V5 respectively, and satisfy: 1.53≤N3≤1.58, 1.51≤N4≤1.55, 1.87≤N5≤1.92, 65≤V3≤80, 50≤V4≤60, 25≤V5≤42.

[0012] In a preferred embodiment, the curvature radius difference of the third lens is R4, the curvature radius difference of the fourth lens is R5, and the curvature radius difference of the fifth lens is R6, and the following conditions are satisfied: 11.5 mm ≤ R4 ≤ 14.5 mm, 1.6 mm ≤ R5 ≤ 5 mm, and 31 mm ≤ R6 ≤ 33 mm.

[0013] In a preferred embodiment, the diagonal field of view of the second projection module is DFOV, and satisfies: 15°≤DFOV≤19°.

[0014] A second aspect of the present invention provides an AR device, comprising the optical system with adjustable display as described in any one of the above items.

[0015] The beneficial effects of the present invention are as follows: by dynamically adjusting the position of the double-cemented lens between the display and the polarization element, and dynamically adjusting the distance between the fourth lens and the fifth lens, the dual-optical path refractive power adjustable function of the optical system can be realized, which can effectively alleviate the user's fatigue and dizziness when observing real images and virtual images. At the same time, by reasonably configuring the lens group, the system's aberrations can be effectively corrected, the imaging quality can be improved, and the user's experience and comfort can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic structural diagram of a first projection module provided by an embodiment of the present invention;

[0017] Figure 2 A schematic diagram of the structure of a second projection module provided by an embodiment of the present invention;

[0018] Figure 3 A schematic diagram of the structure of a polarization element provided in an embodiment of the present invention;

[0019] Figure 4 A spot diagram of a first projection module provided by an embodiment of the present invention;

[0020] Figure 5 A field curvature distortion diagram of the first projection module provided by an embodiment of the present invention;

[0021] Figure 6 An MTF curve diagram of the first projection module provided by an embodiment of the present invention;

[0022] Figure 7 A spot diagram of a second projection module provided by an embodiment of the present invention;

[0023] Figure 8 A field curvature distortion diagram of the second projection module provided by an embodiment of the present invention;

[0024] Fig. 9 This is an MTF curve diagram of the second projection module provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0025] In the present invention, the terms "disposed", "provided with" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, elements or components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0026] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, "plurality" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0027] In addition, some of the above terms may be used to express other meanings in addition to indicating orientation or positional relationship. For example, the term "on" may also be used to express a certain dependency or connection relationship in some cases. For those skilled in the art, the specific meanings of these terms in the present invention can be understood according to specific circumstances.

[0028] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0029] Please refer to Figure 1 and Figure 2 In this embodiment, the adjustable display optical system includes a first projection module, a second projection module, a polarization element 30, a semi-transparent and semi-reflective element 40 and a receiving end 50. The polarization element 30 is tilted relative to the first projection module, and the second projection module and the receiving end 50 are respectively arranged on both sides of the polarization element 30.

[0030] The first projection module is a virtual image projection module, the second projection module is a real image projection module, and the receiving end 50 is a channel for users to receive real images and virtual images. The display 11 can be an LED type light-emitting panel, an LCD type non-self-luminous panel, an LCOS type non-self-luminous panel, etc.

[0031] Specifically, the first projection module includes a display 11 and a double-cemented lens arranged between the display 11 and the polarizing element 30, the double-cemented lens includes a first lens 121 and a second lens 122 arranged in sequence in a direction away from the display 11; the second projection module includes a third lens 21, a fourth lens 22, a fifth lens 23 and a protective element 24 arranged in sequence in a direction away from the polarizing element 30; the semi-transparent and semi-reflective element 40 is attached to a surface of the third lens 21 close to the polarizing element; the distance between the double-cemented lens and the polarizing element 30 is D1, the distance between the double-cemented lens and the display 11 is D2, the distance between the fourth lens 22 and the fifth lens 23 is D3, and the following conditions are satisfied: 9.465mm°≤D1≤13.485mm, 0.045mm≤D2≤1.323mm, 0.199mm≤D3≤0.581mm.

[0032] In this embodiment, the polarizing element 30 includes a flat lens 31 and a first polarizing unit 32 and a second polarizing unit 33 sequentially disposed on a surface of the flat lens 31 close to the semi-transmissive and semi-reflective element 40. The first polarizing element 30 is a quarter wave plate, and the second polarizing unit 33 is a polarizing reflective film.

[0033] During the operation of the first projection module, light containing imaging information is emitted from the display 11. After passing through the double-cemented lens, the imaging light is projected onto the polarization element 30, and then modulated by the first polarization unit 32 and the second polarization unit 33 on the polarization element 30, and then the imaging light is reflected onto the semi-transmissive and semi-reflective element 40. The semi-transmissive and semi-reflective element 40 then reflects part of the imaging light back to the polarization element 30. Since the state of the imaging light has changed, the imaging light that passes through the polarization element 30 again can directly pass through the polarization element 30 to reach the receiving end 50. During the operation of the second projection module, after external light containing environmental information is incident from the outside, the external light passes through the protective element 24, the fifth lens 23, the fourth lens 22 and the third lens 21 in sequence. After the external light is modulated by the semi-transmissive and semi-reflective element 40, the external light can directly pass through the polarization element 30 and be projected into the receiving end 50. The receiving end 50 fuses the received imaging light with the external light, so that the virtual information to be displayed can be superimposed on the real world information.

[0034] During the operation of the first projection module, by adjusting the distance between the polarization element 30 and the display 11 of the double-cemented lens, that is, by adjusting the size of D1 and D2, the optical path system of the first projection module can be adjusted from 0D to -5D diopter; during the operation of the second projection module, by adjusting the distance between the fourth lens 22 and the fifth lens 23, the optical path system of the second projection module can be adjusted from 2D to -5D diopter, thereby realizing the dual optical path diopter adjustment function of the overall optical system.

[0035] It can be understood that by dynamically adjusting the position of the double-cemented lens between the display 11 and the polarization element 30, and dynamically adjusting the distance between the fourth lens 22 and the fifth lens 23, the dual-optical path adjustable diopter function of the optical system can be realized, which can effectively alleviate the user's fatigue and dizziness when observing real images and virtual images. At the same time, by reasonably configuring the lens group, the system's aberrations can be effectively corrected, the imaging quality can be improved, and the user's experience and comfort can be improved.

[0036] Further, in one embodiment, the effective focal length of the first lens 121 is F1, the effective focal length of the second lens 122 is F2, the effective focal length of the first projection module is F3, and the following conditions are satisfied: 0.740≤F1 / F3≤0.828, 1.176≤F2 / F3≤1.430. The first lens 121 is a meniscus lens, and the second lens 122 is a biconvex lens.

[0037] The refractive indices of the first lens 121 and the second lens 122 under D light are N1 and N2 respectively, the Abel numbers of the first lens 121 and the second lens 122 under D light are V1 and V2 respectively, and satisfy: 1.68≤N1≤1.76, 1.55≤N2≤1.65, 52≤V1≤75, 24≤V2≤35.

[0038] The curvature radius of a side of the second lens 122 close to the polarizing element 30 is R1, the curvature radius of a bonding surface of the first lens 121 and the second lens 122 is R2, and the curvature radius of a side of the first lens 121 close to the display 11 is R3, and the following conditions are satisfied: 25mm≤R1≤40mm, -30mm≤R2≤-18mm, -13mm≤R3≤-20mm.

[0039] The half horizontal field of view of the first projection module is HFOV, the half vertical field of view of the first projection module is VFOV, and the following conditions are satisfied: 19°≤HFOV≤23°, 12°≤VFOV≤14°.

[0040] For details, please refer to Figure 4 , Figure 4 is the point diagram of the virtual projection light path corresponding to the first projection module. Figure 4 From the information in, it can be seen that the virtual projection optical path corresponding to the first projection module has a total of 12 fields of view. When the diopter is 0D, the root mean square radius of the 12 fields of view are 2.591um, 5.158um, 5.139um, 5.066um, 5.083um, 6.403um, 6.453um, 7.082um, 5.814um, 5.820um, 7.093um and 6.557um, that is, the root mean square radius of the spot diagram corresponding to all fields of view is less than 8um. When the diopter is in the range of 0D to -5D, the root mean square radius of the virtual projection optical path corresponding to the first projection module changes, but the root mean square radius remains within the size of two pixels, which is acceptable to the human eye.

[0041] Please refer to Figure 5 , Figure 5 is the field curvature and distortion diagram of the virtual projection light path corresponding to the first projection module. Figure 5From the information in, it can be seen that the field curvature of the virtual projection light path corresponding to the first projection module is less than 0.08mm, and the distortion value in the whole field of view does not exceed 5%. When the diopter is adjusted within the range of 0D to -5D, the field curvature of the virtual projection light path corresponding to the first projection module remains within 0.08mm, and the distortion is 3.94%, 2.75%, 1.97%, 1.21%, 0.61% and 0.60% respectively, which meets the design requirements and can be further corrected through the subsequent anti-distortion algorithm.

[0042] Please refer to Figure 6 , Figure 6 is the MTF curve diagram of the virtual projection light path corresponding to the first projection module at 0D, Figure 6 From the information in, it can be seen that the optical transfer function value of the virtual projection optical path corresponding to the first projection module is greater than 0.1 at 67lp / mm in the full field of view, which means that the image quality and resolution meet the design requirements. When the diopter is within the range of 0D to -5D, the optical transfer function curve changes, but it is still greater than 0.1 at 67lp / mm, which means that the imaging quality is relatively good.

[0043] It is understandable that by setting the optical parameter information of the first lens 121, the second lens 122 and the first projection module as a whole, the chromatic aberration of the light path can be effectively corrected and the distortion of the imaging can be improved, thereby ensuring the imaging quality of the first projection module and improving the user experience.

[0044] Further, in one embodiment, the effective focal length of the third lens 21 is F4, the effective focal length of the fourth lens 22 is F5, the effective focal length of the fifth lens 23 is F6, the effective focal length of the second projection module is F7, and the following conditions are satisfied: -0.186≤F4 / F7≤0.241, 0.950≤F5 / F7≤1.340, 0.535≤F6 / F7≤1.219. Among them, the third lens is a positive front meniscus lens, the fourth lens 22 is a biconvex lens, and the fifth lens 23 is a biconcave lens.

[0045] The refractive indices of the third lens 21, the fourth lens 22 and the fifth lens 23 under D light are N3, N4 and N5 respectively, and the Abel numbers of the third lens 21, the fourth lens 22 and the fifth lens 23 under D light are V3, V4 and V5 respectively, and satisfy: 1.53≤N3≤1.58, 1.51≤N4≤1.55, 1.87≤N5≤1.92, 65≤V3≤80, 50≤V4≤60, 25≤V5≤42.

[0046] The difference in curvature radius of the third lens 21 is R4, the difference in curvature radius of the fourth lens 22 is R5, and the difference in curvature radius of the fifth lens 23 is R6, and they satisfy: 11.5mm≤R4≤14.5mm, 1.6mm≤R5≤5mm, 31mm≤R6≤33mm. The difference in curvature radius of the third lens 21 is the difference in curvature radius between the front surface of the third lens 21 and the rear surface of the third lens 21; the difference in curvature radius of the fourth lens 22 is the difference in curvature radius between the front surface of the fourth lens 22 and the rear surface of the fourth lens 22; the difference in curvature radius of the fifth lens 23 is the difference in curvature radius between the front surface of the fifth lens 23 and the rear surface of the fifth lens 23.

[0047] The diagonal field of view of the second projection module is DFOV, and satisfies: 15°≤DFOV≤19°.

[0048] For details, please refer to Figure 7 , Figure 7 is the point diagram of the real projection light path corresponding to the second projection module. Figure 7 From the information, it can be seen that the real projection optical path corresponding to the second projection module has 6 fields of view. When the diopter is 0D, the root mean square radius of the 6 fields of view are 17.049um, 17.840um, 9.309um, 7.844um, 7.634um and 10.862um respectively, that is, the root mean square radius of the spot diagram of all fields of view is below 18um. In the range of diopter from 2D to -5D, the root mean square radius of the real projection optical path corresponding to the second projection module changes, but the size of the diffuse spot can be accepted by the human eye.

[0049] Please refer to Figure 8 , Figure 8 is the field curvature and distortion diagram of the real projection light path corresponding to the second projection module. Figure 8 It can be seen from the information that when the diopter is 0D, the field curvature of the real projection light path corresponding to the second projection module is less than 0.4mm, and the distortion value in the whole field of view does not exceed 5%. When the diopter is adjusted within the range of -2D to 5D, the field curvature of the real projection light path corresponding to the second projection module remains within 0.4mm, and the distortion is 4.43%, 4.47%, 4.53% and 4.39% respectively, which meets the design requirements and can be further corrected through the subsequent anti-distortion algorithm.

[0050] Please refer to Fig. 9 , Fig. 9 is the MTF curve of the real projection light path corresponding to the second projection module at 0D, Fig. 9From the information in, it can be seen that the optical transfer function value of the real projection light path corresponding to the second projection module is greater than 0.2 at 30lp / mm in the full field of view, which means that the image quality and resolution meet the design requirements. When the diopter ranges from 2D to -5D, the optical transfer function curve changes, but it is still greater than 0.15 at 30l p / mm, which means that the imaging quality is relatively good.

[0051] It can be understood that by setting the optical parameter information of the third lens 21, the fourth lens 22, the fifth lens 23 and the second projection module as a whole, the chromatic aberration of the light path can be effectively corrected and the distortion of the imaging can be improved, thereby ensuring the imaging quality of the second projection module and improving the user experience.

[0052] In summary, the present invention can realize the function of adjustable refractive power of dual optical paths of the optical system by dynamically adjusting the position of the double-cemented lens between the display 11 and the polarization element 30 and dynamically adjusting the distance between the fourth lens 22 and the fifth lens 23, which can effectively alleviate the fatigue and dizziness of the user when observing the real image and the virtual image. At the same time, by reasonably configuring the lens group, the aberration of the system can be effectively corrected, the imaging quality can be improved, and the user's experience and comfort can be improved.

[0053] The second aspect of the present invention provides an AR device, which includes the aforementioned adjustable display optical system, which can effectively alleviate the fatigue and dizziness of the user when observing real images and virtual images, effectively correct the system's aberrations, improve imaging quality, and improve the user's experience and comfort.

[0054] The above is only a specific implementation method of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. An optical system with adjustable display, characterized in that: The invention comprises a first projection module, a second projection module, a polarizing element, a semi-transparent and semi-reflective element and a receiving end; the polarizing element is arranged obliquely relative to the first projection module, the second projection module and the receiving end are arranged on both sides of the polarizing element respectively, the first projection module comprises a display and a double-glued lens arranged between the display and the polarizing element, the double-glued lens comprises a first lens and a second lens arranged in sequence away from the display; the second projection module comprises a third lens, a fourth lens, a fifth lens and a protective element arranged in sequence in the opposite direction away from the polarizing element; the semi-transparent and semi-reflective element is attached to a surface of the third lens close to the polarizing element; the distance between the double-glued lens and the polarizing element is D1, the distance between the double-glued lens and the display is D2, the distance between the fourth lens and the fifth lens is D3, and the following conditions are satisfied: 9.465mm°≤D1≤13.485mm, 0.045mm≤D2≤1.323mm, 0.199mm≤D3≤0.581mm.

2. The optical system for adjustable display according to claim 1, characterized in that: The effective focal length of the first lens is F1, the effective focal length of the second lens is F2, the effective focal length of the first projection module is F3, and the following conditions are satisfied: 0.740≤F1 / F3≤0.828, 1.176≤F2 / F3≤1.

430.

3. The optical system for adjustable display according to claim 1, characterized in that: The refractive indices of the first lens and the second lens under D light are N1 and N2 respectively, the Abel numbers of the first lens and the second lens under D light are V1 and V2 respectively, and satisfy: 1.68≤N1≤1.76, 1.55≤N2≤1.65, 52≤V1≤75, 24≤V2≤35.

4. The optical system for adjustable display according to claim 1, characterized in that: The curvature radius of a side of the second lens close to the polarizing element is R1, the curvature radius of a bonding surface of the first lens and the second lens is R2, the curvature radius of a side of the first lens close to the display is R3, and the following conditions are satisfied: 25mm≤R1≤40mm, -30mm≤R2≤-18mm, -13mm≤R3≤-20mm.

5. The adjustable display optical system according to claim 1, characterized in that: A half horizontal field of view of the first projection module is HFOV, a half vertical field of view of the first projection module is VFOV, and the following conditions are satisfied: 19°≤HFOV≤23°, 12°≤VFOV≤14°.

6. The optical system for adjustable display according to claim 1, characterized in that: The effective focal length of the third lens is F4, the effective focal length of the fourth lens is F5, the effective focal length of the fifth lens is F6, the effective focal length of the second projection module is F7, and the following conditions are satisfied: -0.186≤F4 / F7≤0.241, 0.950≤F5 / F7≤1.340, 0.535≤F6 / F7≤1.

219.

7. The optical system for adjustable display according to claim 1, characterized in that: The refractive indices of the third lens, the fourth lens and the fifth lens under D light are N3, N4 and N5 respectively, and the Abel numbers of the third lens, the fourth lens and the fifth lens under D light are V3, V4 and V5 respectively, and satisfy: 1.53≤N3≤1.58, 1.51≤N4≤1.55, 1.87≤N5≤1.92, 65≤V3≤80, 50≤V4≤60, 25≤V5≤42.

8. The optical system for adjustable display according to claim 1, characterized in that: The curvature radius difference of the third lens is R4, the curvature radius difference of the fourth lens is R5, and the curvature radius difference of the fifth lens is R6, and the following conditions are satisfied: 11.5 mm ≤ R4 ≤ 14.5 mm, 1.6 mm ≤ R5 ≤ 5 mm, and 31 mm ≤ R6 ≤ 33 mm.

9. The optical system for adjustable display according to claim 1, characterized in that: The diagonal field of view of the second projection module is DFOV, and satisfies: 15°≤DFOV≤19°.

10. An AR device, characterized in that: An optical system for an adjustable display comprising any one of claims 1 to 9.

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