Optical system and virtual reality device

Abstract

The invention provides an optical system and virtual reality equipment. The optical system provided by the invention comprises a display assembly and an optical assembly, the optical assembly comprises a semi-transparent and semi-reflective film, a first quarter-wave plate, a reflective polarizing film, a first polarizing film and a second quarter-wave plate which are sequentially arranged in the light emitting direction of the display assembly. And the reflection polaroid and the first polaroid have the same vibration transmission direction.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical technology, in particular to an optical system and a virtual reality device. BACKGROUND

[0002] Currently, mainstream virtual reality devices adopt a Pancake scheme. Compared with a Fresnel lens scheme, the Pancake scheme has an advantage of being easier to realize thinness. However, the Pancake scheme is prone to ghosting (also referred to as ghosting), thereby affecting the display effect of the virtual reality device. SUMMARY

[0003] Embodiments of the present application provide an optical system and a virtual reality device to solve the problem of ghosting in the virtual reality device.

[0004] To solve the above technical problem, the present application is implemented as follows: In a first aspect, an embodiment of the present application provides an optical system.

[0005] The optical system provided by the embodiment of the present application comprises a display assembly and an optical assembly; the optical assembly comprises, in sequence along a light ray exit direction of the display assembly, a semi-transmissive semi-reflective film, a first quarter-wave plate, a reflective polarizer, a first polarizer, and a second quarter-wave plate; and the transmission vibration directions of the reflective polarizer and the first polarizer are the same.

[0006] In some embodiments, the optical assembly further comprises a first lens, the first lens comprising a first side and a second side facing away from each other; the semi-transmissive semi-reflective film is arranged on the first side of the first lens, and the first quarter-wave plate, the reflective polarizer, the first polarizer, and the second quarter-wave plate are arranged on the second side of the first lens.

[0007] In some embodiments, the optical assembly further comprises a first lens and a second lens arranged oppositely, the first lens comprising a first side and a second side facing away from each other, the second lens comprising a third side and a fourth side facing away from each other, and the third side of the second lens is opposite to the second side of the first lens; the semi-transmissive semi-reflective film is arranged on the first side of the first lens, and the first quarter-wave plate, the reflective polarizer, the first polarizer, and the second quarter-wave plate are arranged on at least one of the second side of the first lens, the third side of the second lens, and the fourth side of the second lens.

[0008] In some embodiments, the first quarter-wave plate, the reflective polarizer, the first polarizer, and the second quarter-wave plate are all arranged on the third side of the second lens.

[0009] In some embodiments, the first quarter-wave plate, the reflective polarizer, the first polarizer, and the second quarter-wave plate are arranged on the third side of the second lens and the fourth side of the second lens, respectively. In some embodiments, the first quarter-wave plate, the reflective polarizer, the first polarizer, and the second quarter-wave plate are arranged on the third side of the second lens and the fourth side of the second lens, respectively.

[0010] In some embodiments, the first quarter-wave plate, the reflective polarizer, the first polarizer and the second quarter-wave plate are respectively arranged on the second side of the first lens and the fourth side of the second lens.

[0011] In some embodiments, the first quarter-wave plate, the reflective polarizer, the first polarizer and the second quarter-wave plate are respectively arranged on the second side of the first lens and the third side of the second lens.

[0012] In some embodiments, the optical assembly further comprises a phase compensation film, the phase compensation film is arranged on a side of the second quarter-wave plate facing the first polarizer, or the phase compensation film is arranged on a side of the second quarter-wave plate away from the first polarizer.

[0013] In some embodiments, the optical assembly further comprises a second protective layer, the second protective layer is arranged on a side of the second quarter-wave plate away from the first polarizer; wherein the second protective layer comprises a second hardening layer; or the second protective layer comprises a second anti-reflection layer and a second hardening layer.

[0014] In the second aspect, the embodiments of the present application provide a virtual reality device.

[0015] The virtual reality device provided by the embodiments of the present application comprises a housing and any one of the optical systems provided by the embodiments of the present application.

[0016] The above at least one technical scheme adopted by the embodiments of the present application can achieve the following beneficial effects: In the embodiments of the present application, in the case that the reflective polarizer and the first polarizer are both used for transmitting vertically polarized light, the right circularly polarized light emitted by the display assembly can transmit through the half-transmission half-reflection film. The right circularly polarized light transmitting through the half-transmission half-reflection film becomes horizontally polarized light after transmitting through the first quarter-wave plate. The horizontally polarized light is reflected back to the first quarter-wave plate under the action of the reflective polarizer. The reflected horizontally polarized light becomes right circularly polarized light after transmitting through the first quarter-wave plate. The right circularly polarized light is reflected back after being incident on the half-transmission half-reflection film. The right circularly polarized light reflected back by the half-transmission half-reflection film becomes left circularly polarized light. The left circularly polarized light becomes vertically polarized light after transmitting through the first quarter-wave plate. The vertically polarized light transmits through the first polarizer and the second quarter-wave plate in sequence and is projected to the eyes of the user.

[0017] In the case that the vertical linear polarized light is projected to the interface between the optical system and the air on the side of the optical system facing the user's eye, part of the vertical linear polarized light is reflected back by the interface. The reflected vertical linear polarized light, after passing through the second quarter wave plate, becomes horizontal linear polarized light. Since the first polarizer is used to transmit the vertical linear polarized light and the first polarizer can absorb the horizontal linear polarized light; thus, the reflected horizontal linear polarized light is absorbed by the first polarizer. Therefore, the reflected horizontal linear polarized light is prevented from being reflected by the half-transmission half-reflection film and projected to the user's eye to form a ghost image.

[0018] Additional aspects and advantages of the present application will be made apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application or in the related art, the following will briefly introduce the drawings needed to be used in the embodiments or the related art description. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without any creative labor.

[0020] Figure 1 A light path schematic diagram of an optical system provided by an embodiment of the present application; Figure 2 Another light path schematic diagram of an optical system provided by an embodiment of the present application; Figure 3 A schematic diagram of a first optical system provided by an embodiment of the present application; Figure 4 A schematic diagram of the principle of eliminating ghost images of an optical system provided by an embodiment of the present application; Figure 5 A schematic diagram of a second optical system provided by an embodiment of the present application; Figure 6 A schematic diagram of a third optical system provided by an embodiment of the present application; Figure 7 A schematic diagram of a fourth optical system provided by an embodiment of the present application; Figure 8 A schematic diagram of a fifth optical system provided by an embodiment of the present application; Figure 9 A principle diagram of eliminating reflected light by using a quarter wave plate provided by an embodiment of the present application.

[0021] Explanation of reference signs: 1 - optical system; 100 - display assembly; 110 - display device; 120 - second polarizer; 130 - third quarter-wave plate; 140 - first protective layer; 200 - optical assembly; 210 - half-transmission half-reflection film; 220 - first quarter-wave plate; 230 - reflective polarizer; 240 - first polarizer; 250 - second quarter-wave plate; 260 - phase compensation film; 270 - second protective layer; 280 - first lens; 281 - first side of the first lens; 282 - second side of the first lens; 290 - second lens; 291 - third side of the second lens; 292 - fourth side of the second lens. DETAILED DESCRIPTION

[0022] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions of the present application will be described below in conjunction with specific embodiments of the present application and corresponding drawings. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0023] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting" should be understood in a broad sense, for example, can be fixedly connected, can be detachably connected, or integrally connected; can be directly connected, or indirectly connected through an intermediate medium; can be internal communication of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0024] In addition, although the terms used in the present application are selected from the commonly known and used terms, some terms mentioned in the description of the present application can be selected by the applicant according to his or her judgment, and the detailed meanings of which are described in the relevant parts of the description.

[0025] In addition, the present application is required to be understood not only by the actual terms used, but also by the meanings implied by each term.

[0026] First of all, it should be noted that polarization is a property of light, and polarized light can be divided into partially polarized light, linearly polarized light (LPL), elliptically polarized light (EPL) and circularly polarized light (CPL) according to the wave vector perpendicular to the direction of light wave propagation.

[0027] Linearly polarized light includes horizontal linearly polarized light and vertical linearly polarized light. Horizontal linearly polarized light is also called P (Parallel) light, and horizontal linearly polarized light refers to light whose polarization direction is parallel to the incident plane. Vertical linearly polarized light is also called S (Senkrecht) light, and vertical linearly polarized light refers to light whose polarization direction is perpendicular to the incident plane. For circularly polarized light, the electric field and magnetic field components of the electromagnetic wave rotate at a constant rate around the propagation vector. If the field rotates in a left-handed direction relative to the direction of wave propagation, it is called left-handed circularly polarized light (LH-CPL), otherwise it is called right-handed circularly polarized light (RH-CPL).

[0028] For ease of description, in the embodiments of the present application, horizontal linearly polarized light is denoted as P light, vertical linearly polarized light is denoted as S light, left-handed circularly polarized light is denoted as L light, and right-handed circularly polarized light is denoted as R light.

[0029] The technical solutions provided by the embodiments of the present application will be described in detail below with reference to the accompanying drawings. The present application provides an optical system. Referring to Figures 1 to 9 , the optical system 1 provided by the embodiments of the present application includes a display assembly 100 and an optical assembly 200.

[0030] In the embodiments of the present application, the optical assembly 200 includes a beam splitter half-transmissive (BS) 210, a first quarter wave plate 220, a reflective polarizing beam splitter (PBS) 230, a first polarizing plate 240 and a second quarter wave plate 250 arranged in sequence along the light exit direction of the display assembly 100.

[0031] The transmission direction of the reflective polarizer 230 and the first polarizer 240 is the same. For example, both the reflective polarizer 230 and the first polarizer 240 are configured to transmit vertically polarized light; and the reflective polarizer 230 is further configured to reflect horizontally polarized light. Alternatively, both the reflective polarizer 230 and the first polarizer 240 are configured to transmit horizontally polarized light; and the reflective polarizer 230 is further configured to reflect vertically polarized light.

[0032] In this way, in the embodiment of the present application, in the case that both the reflective polarizer 230 and the first polarizer 240 are configured to transmit vertically polarized light, the right circularly polarized light emitted by the display assembly 100 can transmit through the half-transmission half-reflection film 210. The right circularly polarized light transmitting through the half-transmission half-reflection film 210 becomes horizontally polarized light after transmitting through the first quarter-wave plate 220. The horizontally polarized light is reflected back to the first quarter-wave plate 220 under the action of the reflective polarizer 230. The reflected horizontally polarized light becomes right circularly polarized light after transmitting through the first quarter-wave plate 220. The right circularly polarized light is reflected back after being incident on the half-transmission half-reflection film 210. The right circularly polarized light reflected back by the half-transmission half-reflection film 210 becomes left circularly polarized light. The left circularly polarized light becomes vertically polarized light after transmitting through the first quarter-wave plate 220. The vertically polarized light transmits through the first polarizer 240 and the second quarter-wave plate 250 in turn, and is projected to the user's eye.

[0033] In the case that the vertically polarized light is incident on the interface between the side of the optical system 1 facing the user's eye and the air, part of the vertically polarized light is reflected back by the interface. The reflected vertically polarized light becomes horizontally polarized light after transmitting through the second quarter-wave plate 250. Since the first polarizer 240 is configured to transmit vertically polarized light and the first polarizer 240 can absorb horizontally polarized light; thus, the reflected horizontally polarized light is absorbed by the first polarizer 240. Thus, the reflected horizontally polarized light is prevented from being reflected by the half-transmission half-reflection film 210 and projected to the user's eye to form ghosting.

[0034] In the above description, the scheme for eliminating ghosting is illustrated by taking the case that both the reflective polarizer 230 and the first polarizer 240 are configured to transmit vertically polarized light. In other embodiments, both the reflective polarizer 230 and the first polarizer 240 can be configured to transmit horizontally polarized light. Since both the reflective polarizer 230 and the first polarizer 240 are configured to transmit horizontally polarized light, similar to the case that both the reflective polarizer 230 and the first polarizer 240 are configured to transmit vertically polarized light, the scheme for eliminating ghosting in the case that both the reflective polarizer 230 and the first polarizer 240 are configured to transmit horizontally polarized light is not described here. In other words, in the embodiment of the present application, horizontally polarized light and vertically polarized light can be interchanged. Similarly, left circularly polarized light and right circularly polarized light can also be interchanged.

[0035] It should be noted here that the reference Figure 9 In the case where a linear polarizer is designed to transmit vertically polarized light and absorb horizontally polarized light, the vertically polarized light can pass through the linear polarizer normally. After further passing through the quarter-wave plate, the vertically polarized light is projected onto the reflector, where it becomes right-handed circularly polarized light at the reflective surface of the reflector. The right-handed circularly polarized light is reflected back by the reflective surface of the reflector, and the reflected light becomes left-handed circularly polarized light. Further, the left-handed circularly polarized light passes through the quarter-wave plate and becomes horizontally polarized light. Since the linear polarizer is designed to absorb horizontally polarized light, the reflected horizontally polarized light will be absorbed by the linear polarizer.

[0036] Combine Figure 1 、 Figure 2 、 Figure 4 and Figure 9 , exemplarily, the light emitted by the display component 100, after passing through the various optical elements before the first polarizer 240, is directed toward the first polarizer 240. In the case where the first polarizer 240 is used to transmit vertical linear polarized light and absorb horizontal linear polarized light, the vertical linear polarized light can pass through the first polarizer 240 normally. After the vertical linear polarized light further passes through the second quarter wave plate 250, it is projected onto the reflection surface formed between the second quarter wave plate 250 and the air, and the vertical linear polarized light is converted into right-handed circularly polarized light at the reflection surface. The right-handed circularly polarized light is reflected back through the reflection surface, and the reflected light is converted into left-handed circularly polarized light. Further, the left-handed circularly polarized light is converted into horizontal linear polarized light after passing through the second quarter wave plate 250. Since the first polarizer 240 is used to absorb horizontal linear polarized light, the reflected horizontal linear polarized light will be absorbed by the first polarizer 240. In this way, with reference to Figure 4 Since the reflected light is absorbed by the first polarizer 240, it is possible to prevent the reflected light from being reflected again by the interface between the semi-transmissive and semi-reflective film 210 and the air to form a double image.

[0037] It should be noted that Figure 1 and Figure 2 The figure shows a situation where the side of the second quarter-wave plate 250 facing the user's eye is exposed to air, and the interface between the second quarter-wave plate 250 and the air forms a reflective surface. In other embodiments, if the side of the second quarter-wave plate 250 facing the user's eye is provided with other optical elements, the interface between the optical element and the air will also form a reflective surface, which will also reflect light back to the second quarter-wave plate 250. After the reflected light passes through the second quarter-wave plate 250, it is absorbed by the first polarizer 240.

[0038] refer to Figure 2In some embodiments, the display assembly 100 includes a display device 110. For example, the display device can be a liquid crystal display (LCD). Alternatively, the display device can be an organic light-emitting diode (OLED) display, such as a micro OLED and a silicon-based OLED.

[0039] In some embodiments, the incident light of the optical assembly 200 needs to be circularly polarized light, and thus the light emitted by the display assembly 100 is circularly polarized light. For example, the light emitted by a liquid crystal display (LCD) is linearly polarized light, and thus a quarter wave plate can be added in front of the LCD to convert the light emitted by the LCD into circularly polarized light. The light emitted by an organic light-emitting diode (OLED) display is non-polarized light, and thus a linear polarizer can be added in front of the OLED display to convert the light emitted by the OLED display into linearly polarized light, and then a quarter wave plate can be added to convert the linearly polarized light that passes through the linear polarizer into circularly polarized light.

[0040] In some embodiments, the display assembly 100 includes the display device 110, a second polarizer 120, and a third quarter wave plate 130. For example, the second polarizer 120 is a linear polarizer (LP). In this way, the light emitted by the display device 110 can be converted into linearly polarized light by the second polarizer 120. It should be noted that, for example, the first polarizer 240 can also be a linear polarizer. For the sake of distinction, for example, the first polarizer 240 can be referred to as a first linear polarizer, and the second polarizer 120 can be referred to as a second linear polarizer.

[0041] In addition, the third quarter wave plate 130 can convert the horizontal linearly polarized light that passes through the third quarter wave plate 130 into right-handed circularly polarized light. In addition, the light that is reflected back by the semi-transparent and semi-reflective film 210 becomes left-handed circularly polarized light. The left-handed circularly polarized light becomes vertical linearly polarized light after passing through the third quarter wave plate 130. In some embodiments, the second polarizer 120 is perpendicular to the transmission direction of the reflective polarizer 230. For example, in the case where the second polarizer 120 is configured to transmit horizontal linearly polarized light and absorb vertical linearly polarized light, the second polarizer 120 can absorb the vertical linearly polarized light that passes through the third quarter wave plate 130 and is reflected back by the semi-transparent and semi-reflective film 210.

[0042] Reference Figure 1 In some embodiments, the second polarizer 120 and the third quarter wave plate 130 are arranged on the side of the display device 110 that faces the first lens 280.

[0043] In some embodiments, the display assembly 100 further comprises a first protective layer 140. The first protective layer 140 is disposed on a side of the third quarter-wave plate 130 facing away from the display device 110. Exemplarily, the first protective layer 140 comprises a first Anti-Reflection (AR) layer and a first Hard Coating (HC) layer.

[0044] In some embodiments, the third quarter-wave plate 130, the first quarter-wave plate 220 and the second quarter-wave plate 250 are all quarter-wave plates (QWP). It is noted that a quarter-wave plate can generate a phase delay of π / 2 odd multiple; a quarter-wave plate can change an incident linearly polarized light into an elliptically polarized light. If the light vector of the incident linearly polarized light forms an angle of ±45 degrees with the fast and slow axes of the quarter-wave plate, the quarter-wave plate can change the incident linearly polarized light into a circularly polarized light.

[0045] For example, the horizontal linearly polarized light reflected by the reflective polarizer 230 becomes right-handed circularly polarized light after passing through the first quarter-wave plate 220. The right-handed circularly polarized light becomes left-handed circularly polarized light after being reflected by the half-transmission half-reflection film 210. The left-handed circularly polarized light becomes vertical linearly polarized light after passing through the first quarter-wave plate 220. Thus, it can be known from this example that the linearly polarized light, after passing through a quarter-wave plate, being reflected back and passing through the quarter-wave plate again, becomes linearly polarized light whose polarization direction is perpendicular to that of the original linearly polarized light.

[0046] In some embodiments, the optical axes of the third quarter-wave plate 130 and the first quarter-wave plate 220 are ideally perpendicular. The optical axes of the third quarter-wave plate 130 and the first quarter-wave plate 220 form an angle of 45 degrees or 135 degrees with the adjacent polarizer, respectively. In this way, the horizontal linearly polarized light emitted by the display device 110 and passing through the second linear polarizer 120 is still horizontal linearly polarized light after passing through the first quarter-wave plate 220 for the first time.

[0047] In some embodiments, the transmittance of the half-transmission half-reflection film 210 is 50%, and the reflectance of the half-transmission half-reflection film 210 is 50%. In this way, half of the light rays incident on the half-transmission half-reflection film 210 pass through the half-transmission half-reflection film 210, and the other half of the light rays are reflected back by the half-transmission half-reflection film 210. Of course, in other embodiments, the transmittance and reflectance of the half-transmission half-reflection film 210 can also be other parameters, which are not listed one by one here.

[0048] Reference Figure 1In some embodiments, the optical assembly 200 further comprises a first lens 280. The first lens 280 comprises a first side 281 and a second side 282 facing away from each other. The semi-transmissive and semi-reflective film 210 is disposed on the first side 281 of the first lens 280. The first quarter wave plate 220, the reflective polarizer 230, the first polarizer 240 and the second quarter wave plate 250 are disposed on the second side 282 of the first lens 280. In this way, each film layer can be disposed on the first lens 280, so as to improve the compactness of the optical system 1.

[0049] For example, the first side 281 of the first lens 280 is convex, the second side 282 of the first lens 280 is flat, and the middle region of the first side 281 of the first lens 280 protrudes away from the second side 282 of the first lens 280 relative to the edge region.

[0050] Reference is made to Figures 4 to 7 In some embodiments, the optical assembly 200 further comprises a first lens 280 and a second lens 290 disposed opposite to each other. The first lens 280 comprises a first side 281 and a second side 282 facing away from each other, and the second lens 290 comprises a third side 291 and a fourth side 292 facing away from each other. The third side 291 of the second lens 290 is opposite to the first side 281 of the first lens 280.

[0051] For example, the first side 281 of the first lens 280 is convex, the second side 282 of the first lens 280 is flat, and the middle region of the first side 281 of the first lens 280 protrudes away from the second side 282 of the first lens 280 relative to the edge region. The third side 291 of the second lens 290 is flat. The fourth side 292 of the second lens 290 can be flat, or the fourth side 292 of the second lens 290 can be convex. In the case where the fourth side 292 of the second lens 290 is convex, the middle region of the fourth side 292 of the second lens 290 protrudes away from the third side 291 of the second lens 290 relative to the edge region.

[0052] Further, in some embodiments, the semi-transmissive and semi-reflective film 210 is disposed on the first side 281 of the first lens 280. The first quarter wave plate 220, the reflective polarizer 230, the first polarizer 240 and the second quarter wave plate 250 are respectively disposed on at least one of the second side 282 of the first lens 280, the third side 291 of the second lens 290 and the fourth side 292 of the second lens 290. In this way, by disposing the first lens 280 and the second lens 290, each film layer can be disposed on the first lens 280 and the second lens 290 as required, so as to improve the convenience of disposing the film layers.

[0053] It should be noted that the first quarter-wave plate 220, the reflective polarizer 230, the first polarizer 240 and the second quarter-wave plate 250 are arranged on at least one of the second side surface 282 of the first lens 280, the third side surface 291 of the second lens 290 and the fourth side surface 292 of the second lens 290, respectively, means that at least one side surface is selected from the three side surfaces of the second side surface 282 of the first lens 280, the third side surface 291 of the second lens 290 and the fourth side surface 292 of the second lens 290 as an arrangement surface, and the first quarter-wave plate 220, the reflective polarizer 230, the first polarizer 240 and the second quarter-wave plate 250 are arranged on the selected arrangement surface, respectively.

[0054] Exemplarily, in the case of selecting the third side surface 291 of the second lens 290 and the fourth side surface 292 of the second lens 290 as the arrangement surfaces, the first quarter-wave plate 220, the reflective polarizer 230, the first polarizer 240 and the second quarter-wave plate 250 can be arranged on the third side surface 291 of the second lens 290 and the fourth side surface 292 of the second lens 290, respectively. For example, the first quarter-wave plate 220 can be arranged on the third side surface 291 of the second lens 290, and the reflective polarizer 230, the first polarizer 240 and the second quarter-wave plate 250 can be arranged on the fourth side surface 292 of the second lens 290.

[0055] When the first quarter-wave plate 220, the reflective polarizer 230, the first polarizer 240 and the second quarter-wave plate 250 are arranged, it is only required that the half-transmission half-reflection film 210, the first quarter-wave plate 220, the reflective polarizer 230, the first polarizer 240 and the second quarter-wave plate 250 are arranged in sequence along the light-exit direction of the display assembly 100.

[0056] Reference Figure 4 In some embodiments, the first quarter-wave plate 220, the reflective polarizer 230, the first polarizer 240 and the second quarter-wave plate 250 are all arranged on the third side surface 291 of the second lens 290. In this way, the film layers can be located on the side of the second lens 290 away from the user's eyes, so that the film layers are built-in, thereby avoiding the film layers being contacted by the user. Thus, the film layers can be effectively prevented from being scratched, and the service life of the film layers can be improved.

[0057] Reference Figure 5In some embodiments, the first quarter-wave plate 220, the reflective polarizer 230, the first polarizer 240 and the second quarter-wave plate 250 are respectively arranged on the third side surface 291 of the second lens 290 and the fourth side surface 292 of the second lens 290. In this way, the film layers can be divided into two combined film layers, and the two combined film layers are arranged on two sides of the second lens 290 respectively. Since the film layers are divided into two combined film layers, the thickness of the composite film can be thinned, and thus the difficulty of the film pasting process can be reduced to improve the convenience of film layer arrangement.

[0058] Reference Figure 6 In some embodiments, the first quarter-wave plate 220, the reflective polarizer 230, the first polarizer 240 and the second quarter-wave plate 250 are respectively arranged on the second side surface 282 of the first lens 280 and the fourth side surface 292 of the second lens 290. In this way, the film layers can be divided into two combined film layers, and the two combined film layers are arranged on one side of the first lens 280 and one side of the second lens 290 respectively to improve the convenience of film layer arrangement.

[0059] Reference Figure 7 In some embodiments, the first quarter-wave plate 220, the reflective polarizer 230, the first polarizer 240 and the second quarter-wave plate 250 are respectively arranged on the second side surface 282 of the first lens 280 and the third side surface 291 of the second lens 290. In this way, the film layers can be divided into two combined film layers, and the two combined film layers are arranged on one side of the first lens 280 and one side of the second lens 290 respectively to improve the convenience of film layer arrangement. In addition, the film layers are all located on the side of the second lens 290 away from the user's eyes, realizing the built-in of the film layers, so as to avoid the film layers being touched by the user. Thus, the film layers can be effectively prevented from being scratched, and the service life of the film layers can be improved.

[0060] Reference Figure 1 , Figures 4 to 7 In some embodiments, the optical assembly 200 further comprises a phase compensation film 260. The phase compensation film 260 is arranged on the side of the second quarter-wave plate 250 facing the first polarizer 240, or the phase compensation film 260 is arranged on the side of the second quarter-wave plate 250 away from the first polarizer 240. In this way, the phase compensation film 260 can compensate for the phase difference of the second quarter-wave plate 250 at the oblique viewing angle, so that the second quarter-wave plate 250 and the phase compensation film 260 have a high ellipticity (ellipticity is used to represent the circular polarization performance) at the side viewing angle, thereby improving the display effect. Exemplarily, the optical axis of the phase compensation film 260 is perpendicular to the film surface, and the phase compensation (C-plate) film 260 is used for vertical compensation.

[0061] Reference Figure 1 , Figures 4 to 7In some embodiments, the optical assembly 200 further comprises a second protective layer 270. The second protective layer 270 is disposed on the side of the second quarter wave plate 250 facing away from the first polarizer 240. In other words, in some embodiments, the second protective layer 270 is located on the outer surface of the optical system 1 to improve the wear resistance of the optical system 1.

[0062] Exemplarily, the second protective layer 270 comprises a second hard coating (HC) layer. In this way, the hardness of the surface of the optical assembly 200 can be improved by using the second protective layer 270 to reduce the possibility of surface scratches, thereby improving the service life of the optical system 1.

[0063] Alternatively, the second protective layer 270 comprises a second anti-reflection (AR) layer and a second hard coating layer. In this way, the second protective layer 270 not only has a high hardness to reduce the possibility of surface scratches of the optical assembly 200, but also has the function of reducing reflected light and improving light transmittance, thereby improving the display effect of the optical system 1.

[0064] Further, the optical system 1 further comprises a phase compensation film 260. The phase compensation film 260 can be located on the side of the second quarter wave plate 250 facing the first polarizer 240, or the phase compensation film 260 can be located on the side facing away from the first polarizer 240.

[0065] Reference Figure 5 In some embodiments, the first quarter wave plate 220, the reflective polarizer 230 and the first polarizer 240 are disposed on the third side 291 of the second lens 290. The second quarter wave plate 250, the phase compensation film 260 and the second protective layer 270 are disposed on the fourth side 292 of the second lens 290.

[0066] Reference Figure 6 In some embodiments, the first quarter wave plate 220, the reflective polarizer 230 and the first polarizer 240 are disposed on the second side 282 of the first lens 280. The second quarter wave plate 250, the phase compensation film 260 and the second protective layer 270 are disposed on the fourth side 292 of the second lens 290.

[0067] Reference Figure 7 In some embodiments, the first quarter wave plate 220, the reflective polarizer 230 and the first polarizer 240 are disposed on the second side 282 of the first lens 280. The second quarter wave plate 250, the phase compensation film 260 and the second protective layer 270 are disposed on the third side 291 of the second lens 290.

[0068] In one embodiment, the film layers are connected by an adhesive layer between adjacent film layers. The film layers adjacent to the lens are also connected to the lens by an adhesive layer. Exemplarily, the adhesive layer can be a pressure sensitive adhesive (PSA).

[0069] The applicant also tested the contrast of the optical system 1 using a 10x10 checkerboard. According to the contrast test, the average contrast of the optical system 1 is improved by 12% and the maximum contrast is improved by 27% in the scheme with the second quarter-wave plate 250 compared with the scheme without the second quarter-wave plate 250.

[0070] The virtual reality device provided by the embodiment of the present application includes a shell and any one of the optical systems 1 provided by the embodiments of the present application. Exemplarily, the shell is the outer shell of the virtual reality device.

[0071] It should be noted that, in this document, the terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed or inherent to such a process, method, article or device.

[0072] Although the embodiments of the present application have been shown and described, it should be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the embodiments of the present application, and the scope of the embodiments of the present application is defined by the appended claims and their equivalents.

Claims

1. An optical system, characterized in that: include: Display assembly (100) and optical assembly (200); The optical component (200) comprises a semi-transmissive and semi-reflective film (210), a first quarter-wave plate (220), a reflective polarizer (230), a first polarizer (240), and a second quarter-wave plate (250) which are sequentially arranged along the light emitting direction of the display component (100); the reflective polarizer (230) and the first polarizer (240) have the same transmission direction.

2. The optical system according to claim 1, wherein: The optical assembly (200) further includes a first lens (280), wherein the first lens (280) includes a first side surface (281) and a second side surface (282) that are opposite to each other; The semi-transparent and semi-reflective film (210) is arranged on a first side surface (281) of the first lens (280), and the first quarter-wave plate (220), the reflective polarizer (230), the first polarizer (240) and the second quarter-wave plate (250) are arranged on a second side surface (282) of the first lens (280).

3. The optical system according to claim 1, wherein: The optical assembly (200) further comprises a first lens (280) and a second lens (290) arranged opposite to each other, the first lens (280) comprising a first side surface (281) and a second side surface (282) which are separated from each other, the second lens (290) comprising a third side surface (291) and a fourth side surface (292) which are separated from each other, and the third side surface (291) of the second lens (290) is opposite to the second side surface (282) of the first lens (280); The semi-transparent and semi-reflective film (210) is arranged on the first side surface (281) of the first lens (280), and the first quarter-wave plate (220), the reflective polarizer (230), the first polarizer (240) and the second quarter-wave plate (250) are respectively arranged on at least one of the second side surface (282) of the first lens (280), the third side surface (291) of the second lens (290) and the fourth side surface (292) of the second lens (290).

4. The optical system according to claim 3, wherein: The first quarter-wave plate (220), the reflective polarizer (230), the first polarizer (240) and the second quarter-wave plate (250) are all arranged on the third side surface (291) of the second lens (290).

5. The optical system according to claim 3, wherein: The first quarter-wave plate (220), the reflective polarizer (230), the first polarizer (240), and the second quarter-wave plate (250) are respectively arranged on the third side surface (291) of the second lens (290) and the fourth side surface (292) of the second lens (290).

6. The optical system according to claim 3, wherein: The first quarter-wave plate (220), the reflective polarizer (230), the first polarizer (240) and the second quarter-wave plate (250) are respectively arranged on the second side surface (282) of the first lens (280) and the fourth side surface (292) of the second lens (290).

7. The optical system according to claim 3, wherein: The first quarter-wave plate (220), the reflective polarizer (230), the first polarizer (240) and the second quarter-wave plate (250) are respectively arranged on the second side surface (282) of the first lens (280) and the third side surface (291) of the second lens (290).

8. The optical system according to any one of claims 1 to 7, characterized in that The optical component (200) further includes a phase compensation film (260), wherein the phase compensation film (260) is provided on a side of the second quarter-wave plate (250) facing the first polarizer (240), or the phase compensation film (260) is provided on a side of the second quarter-wave plate (250) facing away from the first polarizer (240).

9. The optical system according to any one of claims 1 to 7, characterized in that The optical component (200) further comprises a second protective layer (270), wherein the second protective layer (270) is provided on a side of the second quarter-wave plate (250) facing away from the first polarizer (240); Wherein, the second protective layer (270) includes a second hardening layer; or, the second protective layer (270) includes a second anti-reflection layer and a second hardening layer.

10. A virtual reality device, characterized in that: The optical system comprises a housing and the optical system according to any one of claims 1 to 9.

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