CN218413185U - Light beam deflection device and projection system - Google Patents

Abstract

The embodiment of the application provides a light turning device and a projection system, wherein the light turning device comprises a light guide part and a turning part, the turning part is arranged on an emergent light path of the light guide part and comprises a first transflective element and a second transflective element which are connected in an angle mode, and a reflecting element connected between the first transflective element and the second transflective element; the first transflective element and the second transflective element are used for transmitting light rays with incidence angles smaller than a first angle value and in accordance with a set wavelength range, reflecting light rays with incidence angles larger than a second angle value and in accordance with the set wavelength range, and the first angle value is smaller than the second angle value; the light guide is used for guiding light rays to enter the first transflective element at an incidence angle smaller than a first angle value, and the second transflective element is used for transmitting the light rays entering the second transflective element at the incidence angle smaller than the first angle value. The light turning device that this application embodiment provided can turn over light, avoids light reverse transmission to cause the waste simultaneously, improves the utilization ratio of light energy.

Description

Light refraction device and projection system

technical field

The present application relates to the field of optics, in particular to a light refraction device and a projection system.

Background technique

In an optical system, it is often necessary to use optical devices such as prisms to bend light to change the direction of light propagation. However, existing optical devices such as prisms not only bend the light, but also reflect the light in the incident direction, causing the light to be transmitted backwards, resulting in a waste of light energy.

Utility model content

The purpose of this application is to propose a light refraction device and a projection system to solve the above problems. The present application achieves the above object through the following technical solutions.

In the first aspect, the embodiment of the present application provides a light refraction device, including: a light guide and a refraction member. The second transreflective element and the reflective element, the first transreflective element and the second transreflective element are connected at an angle, and the reflective element is connected between the first transreflective element and the second transreflective element; the first transreflective element and the second transflective element The transflective elements are used to transmit the light whose incident angle is smaller than the first angle value and meet the set wavelength range, and reflect the light whose incident angle is greater than the second angle value and meet the set wavelength range, wherein the first angle value is smaller than the second Angle value; the light guide is used to guide the light to enter the first transflective element at an incident angle smaller than the first angle value, and the second transflective element is used to transmit the second transflective element at an incident angle smaller than the first angle value of light.

In one embodiment, a part of the light transmitted by the first transflective element is incident on the reflective element, and after being reflected by the reflective element, it is incident on the first transflective element at an incident angle greater than the second angle value, and is transmitted by the first transflective element. After being reflected by the reflective element, it is incident on the second transflective element at an incident angle smaller than the first angle value and then emerges.

In one embodiment, a part of light transmitted by the first transflective element is incident on the second transflective element at an incident angle greater than the second angle value, and is reflected by the second transflective element to the reflective element, and reflected by the reflective element Then, it is incident on the second transflective element at an incident angle smaller than the first angle value and then emerges.

In one embodiment, the first transflective element comprises a first optical multilayer interference film, the second transflective element comprises a second optical multilayer interference film, the first optical multilayer interference film and the second optical multilayer interference film Both are used to transmit the light whose incident angle is smaller than the first angle value and meet the set wavelength range, and reflect the light whose incident angle is greater than the second angle value and meet the set wavelength range.

In one embodiment, the first transflective element further includes a first transparent sheet coated with a first optical multilayer interference film; the second transflective element further includes a second transparent sheet coated with There is a second optical multilayer interference film; the reflection element is a reflection mirror connected between the first transparent sheet and the second transparent sheet.

In one embodiment, the light guide is a hollow conduit.

In one embodiment, one end of the light guide member facing the first transflective element is provided with an exit end surface, and the exit end surface is connected to the first transflective element.

In one embodiment, the shape of the output end surface is consistent with the incident surface of the first transflective element, and the output end surface coincides with the incident surface of the first transflective element.

In one embodiment, the optical axis of the first transflective element and the optical axis of the light guide are parallel to each other, the optical axis of the second transflective element and the optical axis of the first transflective element are perpendicular to each other, and the normal of the reflective element It forms an included angle of 45° with the optical axis of the first transflective element.

In the second aspect, the embodiment of the present application provides a projection system, including a light source, a light modulation device, a light combining prism, and the light refraction device described in the first aspect. The light modulating device is used to guide the outgoing light of the light source to the light modulating device, the light modulating device is used to modulate the light to form image light carrying image information, and the light combining prism is used to synthesize the image light.

Compared with the prior art, the light refraction device provided by the embodiment of the present application can realize the refraction of light through the cooperation of the first transflective element, the second transflective element and the reflective element, and utilizes the first transflective element and the second transflective element The two transflective elements transmit the light whose incident angle is smaller than the first angle value and meet the set wavelength range, and reflect the optical characteristics of the light whose incident angle is greater than the second angle value and meet the set wavelength range, which can avoid large reflections by the reflective element. The angled light passes through the first transflective element again and returns to the light guide, thereby avoiding the waste caused by the reverse transmission of the light to the greatest extent, and improving the utilization rate of light energy.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those skilled in the art, other drawings can also be obtained based on these drawings without any creative effort.

FIG. 1 is a schematic diagram of a light refraction device provided by an embodiment of the present application.

FIG. 2 is a graph of spectral characteristics of the first transflective element and the second transflective element in the light refraction device provided by the embodiment of the present application.

Fig. 3 is another schematic diagram of the light refraction device provided by the embodiment of the present application.

Fig. 4 is a schematic diagram of a light guide in the light refraction device provided by the embodiment of the present application.

FIG. 5 is a schematic diagram of a projection system provided by an embodiment of the present application.

FIG. 6 is a schematic structural diagram of a liquid crystal panel and a light-combining prism in the projection system shown in FIG. 5 .

Detailed ways

Embodiments of the present application are described in detail below, examples of which are shown in the drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the figures are exemplary, are only for explaining the present application, and should not be construed as limiting the present application.

In order to enable those skilled in the art to better understand the solutions of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Apparently, the described embodiments are only some of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making creative efforts belong to the scope of protection of this application.

Please refer to FIG. 1 , the light refraction device 100 provided by the embodiment of the present application includes a light guide 110 and a deflection member 120, the deflection member 120 is arranged on the exit light path of the light guide 110, and the deflection member 120 includes a first transparent The reflective element 121, the second transflective element 122 and the reflective element 123, the first transflective element 121 and the second transflective element 122 are connected at an angle, the reflective element 123 is connected to the first transflective element 121 and the second transflective element 122 between.

FIG. 2 is a graph showing the spectral characteristics of the first transflective element 121 and the second transflective element 122. Please refer to FIG. 1 and FIG. incident light, and reflect long-wavelength incident light, and the spectral characteristics of the first transflective element 121 and the second transflective element 122 change with the incident angle of the light beam. When the incident angle increases, the first transflective element 121 and the spectral characteristics of the second transflective element 122 shift to the short wavelength direction.

Curve 1 in FIG. 2 is the reflectivity curve of the first transflective element 121 and the second transflective element 122 when the incident angle is θ ₁ (0°≤θ ₁ <90°). As shown in curve 1, the wavelength is greater than λ ₂ incident light rays can be reflected, and incident light rays with wavelengths smaller than λ ₂ are transmitted. Curve 2 is the reflectivity curve of the first transflective element 121 and the second transflective element 122 when the incident angle is θ ₂ (0°≤θ ₁ <θ ₂ <90°), as shown in curve 2, the wavelength is greater than λ ₁ The incident light with wavelength is reflected, and the incident light with wavelength less than λ ₁ is transmitted (λ ₁ <λ ₂ ). Therefore, for the light rays whose wavelength λ satisfies _λ1 <λ< _λ2 , when the incident angle θ< _θ1 , the light is transmitted by the first transflective element 121 and the second transflective element 122; when the incident angle θ> _θ2 , the light is reflected by the first transflective element 121 and the second transflective element 122 .

Thus, the first transflective element 121 and the second transflective element 122 can transmit incident light at a small angle and reflect incident light at a large angle for light with a specific spectral width, that is, the first transflective element 121 and the second transflective element The transflective element 122 can be used to transmit the light whose incident angle is smaller than the first angle value (such as θ ₁ ) and conforms to the set wavelength range, and reflect the light whose incident angle is larger than the second angle value (such as θ ₂ ) and conforms to the set wavelength range Light; wherein, the first angle value is smaller than the second angle value; the set wavelength range may be 390nm-470nm, that is, the light conforming to the set wavelength range may be short-wave light with a wavelength between 390nm-470nm.

Further, the light guide 110 is used to guide the light to enter the first transflective element 121 at an incident angle smaller than the first angle value, and the second transflective element 122 is used to transmit the light incident to the second transflective element at an incident angle smaller than the first angle value. light from the transflective element 122 .

Specifically, the light is confined in the light guide 110 after being incident on the light guide 110, and can enter the first transflective element 121 at an incident angle smaller than the first angle value through the light guiding function of the light guide 110, The light can enter the folding member 120 smoothly through the first transflective element 121. Since the incident angles of the light rays incident on the first transflective element 121 are usually different, the light paths of light rays with different incident angles in the folding member 120 are different. Utilizing the optical characteristics of the first transflective element 121 and the second transflective element 122 to transmit the light with an incident angle smaller than the first angle value and reflect the light with an incident angle greater than the second angle value, the large-angle light reflected by the reflective element 123 can be avoided (The light whose incident angle is greater than the second angle value) passes through the first transflective element 121 again and returns to the light guide 110, thereby avoiding the light waste caused by the reverse transmission of the light to the greatest extent, and improving the utilization rate of light energy.

Further, the second transflective element 122 is used to transmit the light rays whose incident angle is smaller than the first angle value, and reflect the optical characteristics of the light rays whose incident angle is larger than the second angle value, so that finally only the light rays with the incident angle smaller than the first angle value Only the light that enters the second transflective element 122 can exit, that is, the second transflective element 122 finally emits the light that is incident on the second transflective element 122 at a small angle, and according to the law of refraction of light, the incident angle is relatively small. The hourly refraction angle (that is, the exit angle) is also small, so that the exit angle of the light can be limited, and the convergence of the light can be realized; at the same time, the first transflective element 121 and the second transflective element 122 are connected at an angle, through the first transflective The cooperation of the reflective element 121 , the second transflective element 122 and the reflective element 123 can realize light deflection and change the propagation direction of light.

In some implementations, a part of the light transmitted by the first transflective element 121 (for example, the first marginal ray 131 ) may be incident on the reflective element 123, and after reflection by the reflective element 123, incident on the The first transflective element 121 is incident on the second transflective element 122 at an incident angle smaller than the first angle value after being reflected by the first transflective element 121 , and emerges to form usable light.

In some implementations, a part of the light transmitted by the first transflective element 121 (for example, the second edge ray 132 ) may enter the second transflective element 122 at an incident angle greater than the second angle value, and pass through the second transflective element 122 is reflected to the reflective element 123 , and then reflected by the reflective element 123 , enters the second transflective element 122 at an incident angle smaller than the first angle value, and emerges to form usable light.

Certainly, the above-mentioned embodiment only uses the first marginal ray 131 and the second marginal ray 132 as an example to illustrate the folding principle of the light deflection device 100. Except for the first marginal ray 131 and the second marginal ray 132, the light guide 110 The light to the first transflective element 121 may also include a central ray (not shown), and the incident angle of the central ray to the first transflective element 121 is smaller than the first edge ray 131 and the second edge ray 132, that is, smaller than the first edge ray 131 and the second edge ray 132. Therefore, the central ray can also pass through the first transflective element 121 and finally exit from the second transflective element 122 .

In some embodiments, the first transflective element 121 may include a first optical multilayer interference film (not shown), and the second transflective element 122 may include a second optical multilayer interference film (not shown). The spectral characteristics of the optical multilayer interference film change with the incident angle of the light beam. When the incident angle increases, the effective thickness of the film decreases, and the spectral characteristics of the film system shift to the short wavelength direction. The optical multilayer interference film can be formed by laminating multiple film layers. Through the interference effect of the optical multilayer interference film, the multi-beam interference is used, so that both the first optical multilayer interference film and the second optical multilayer interference film can be used for The light with an incident angle smaller than the first angle value and within the set wavelength range is transmitted, and the light with an incident angle greater than the second angle value and within the set wavelength range is reflected, thereby achieving the function of the light deflection device 100 to limit the outgoing light angle.

Please refer to FIG. 3 , in some embodiments, the first transflective element 121 can also include a first transparent sheet 1211, and the first transparent sheet 1211 is coated with a first optical multilayer interference film; the second transflective element 122 can also include The second transparent sheet 1221, the second transparent sheet 1221 is coated with the second optical multilayer interference film; the reflective element 123 may be a mirror connected between the first transparent sheet 1211 and the second transparent sheet 1221.

Thus, the turning member 120 is equivalent to a hollow structure surrounded by two coated transparent sheets and a reflective mirror. Filling makes the turning member 120 have the characteristics of light weight, low processing cost, simple structure and easy assembly, which greatly improves the market competitiveness of the light turning device 100 .

In this embodiment, the first transparent sheet 1211, the second transparent sheet 1221, and the reflective element 123 can be substantially rectangular sheet structures, and the first transparent sheet 1211, the second transparent sheet 1221, and the reflective element 123 can be enclosed to form a hollow triangular prism structure. Wherein, the first transparent sheet 1211 and the second transparent sheet 1221 may be transparent glass sheets, transparent quartz sheets or transparent plastic sheets or the like. The first optical multilayer interference film can be disposed on the surface of the first transparent sheet 1211 facing the reflective element 123 , and the second optical multilayer interference film can be disposed on the surface of the second transparent sheet 1221 facing the reflective element 123 . The coated surfaces of the first transparent sheet 1211 and the second transparent sheet 1221 may be flat, curved, or sawtooth surfaces composed of multiple flat surfaces.

In this embodiment, the included angle between the normal of the reflective element 123 and the optical axis of the light guide 110 may be any angle between 0° and 90°, so as to realize the bending of light in any direction. As an example, the included angle between the normal of the reflective element 123 and the optical axis of the light guide 110 is 45 degrees, so that the light can be deflected by 90 degrees and emitted.

In this embodiment, the first transflective element 121 may be perpendicular to the optical axis of the light guide 110, or the angle between the first transflective element 110 and the optical axis of the light guide 110 is an acute angle, that is, the optical axis of the first transflective element 121 The optical axis of the light guide 110 may be parallel to each other, or intersect with the optical axis of the light guide 110 . The included angle between the second transflective element 122 and the first transflective element 121 may be a right angle, an acute angle or an obtuse angle, so as to meet the requirements of transmission and reflection of different light rays.

As an example, the optical axis of the first transflective element 121 is parallel to the optical axis of the light guide 110, the optical axis of the second transflective element 122 is perpendicular to the optical axis of the first transflective element 121, and the reflective element 123 The normal to the first transflective element 121 forms an included angle of 45° with the optical axis of the first transflective element 121. At this time, the first transparent sheet 1211, the second transparent sheet 1221 and the reflective element 123 enclose to form a right-angled triangular prism structure, which can refract the incident light After 90°, it is equivalent to realizing the function of a right-angle prism.

In some other embodiments, the folding member 120 may also include a triangular prism (not shown), the triangular prism may include a first side, a second side and a third side, and the first side may be coated with a first optical multilayer interference film to form The second transflective element 121 is coated with the second optical multilayer interference film to form the second transflective element 122 , and the third side is coated with a reflective film to form the reflective element 123 . As an example, the triangular prism may be a right-angle prism, so that the incident light can be deflected by 90° and then emitted.

Please refer to FIG. 3 and FIG. 4 , the end of the light guide 110 facing the first transflective element 121 is provided with an exit end surface 111, and the end away from the first transflective element 121 is provided with an incident end surface 112, and the exit end surface 111 can be connected to the first transflective element 121. The transflective element 121 , that is, the exit end surface 111 and the first transflective element 121 are attached to each other to ensure that light does not escape from between the exit end surface 111 and the first transflective element 121 . Further, the shape of the exit end surface 111 is consistent with the shape of the incident surface of the first transflective element 121, and the exit end surface 111 coincides with the incident surface of the first transflective element 121, so that an optical waveguide can be formed to maintain the optical expansion to the greatest extent. quantity.

In some embodiments, the light guide 110 may be a hollow conduit to reduce the weight of the light guide 110 , thereby reducing the overall weight of the light deflection device 100 and facilitating assembly.

In this embodiment, the light guiding element 110 may be a hollow tube in the shape of a cuboid or a hollow tube in the shape of a prism. Specifically, when the outgoing end surface 111 and the incident end surface 112 are both rectangular and have the same area, the light guide 110 is a cuboid hollow conduit. When the outgoing end surface 111 and the incident end surface 112 are both rectangular and the areas of the outgoing end surface 111 and the incident end surface 112 are different, the light guide 110 is a truncated square hollow conduit. Wherein, the area of the exit end surface 111 may be larger than that of the entrance end surface 112, which can make the area of the exit light spot larger than the area of the incident light spot, thereby reducing the divergence angle of the light beam. In some other implementation manners, the area of the exit end surface 111 may also be smaller than that of the entrance end surface 112, so that the exit light spot has a smaller size.

In this embodiment, the inner wall of the hollow conduit is coated with a high-reflection film to transmit the incident light to the exit end surface 111 by utilizing the light reflection on the inner wall. Different hollow conduit parameters can be set according to different light sources to guide the light to exit through the exit end surface 111. And incident to the first transflective element 121 at an incident angle smaller than the first angle value.

In some other embodiments, not all the light emitted from the exit end surface 111 can enter the first transflective element 121 at an incident angle smaller than the first angle value, for example, a part of the light emitted from the exit end surface 111 is incident at an angle greater than the first angle value. When the angle of incidence is incident on the first transflective element 121, this part of light cannot pass through the first transflective element 121, but will be reflected back into the hollow conduit by the first transflective element 121, and then re-reflected back and forth in the hollow conduit. The light is emitted through the exit end surface 111 to reach the first transflective element 121 , thereby improving the utilization rate of the light.

Please refer to FIG. 1 and FIG. 5 together. The embodiment of the present application also provides a projection system 200, including a light source 210, a light modulation device 220, a light combining prism 230, and a light refraction device 100. The light refraction device 100 is located on The outgoing light path of the light source 210 is used to guide the outgoing light of the light source 210 to the light modulation device 220, the light modulation device 220 is used to modulate the light to form image light carrying image information, and the light combining prism 230 is used to synthesize the image light.

The projection system 200 provided in the embodiment of the present application can realize the deflection of light through the light deflection device 100, so as to guide the outgoing light of the light source 210 to the light modulation device 220, and utilize the first transflective element 121 and the second transflective element 122 has the optical characteristics of transmitting light that is smaller than the first angle value and conforming to the set wavelength range, and reflecting light that is greater than the second angle value and conforming to the set wavelength range, so that only the incident angle of the first angle value is smaller than the first angle value. Only the light from the second transflective element 122 can exit, that is, the second transflective element 122 finally emits light that is incident on the second transflective element 122 at a small angle, and when the incident angle is small, the outgoing angle is also small, thus It can play the role of limiting the angle of light emission and realize the convergence of light.

In this embodiment, the projection system 200 may be a liquid crystal projection system, and the projection system 200 may also include a projection lens 240. The projection lens 240 is arranged on the outgoing light path of the light-combining prism 230, and is used to combine the combined light emitted by the light-combining prism 230 Projected onto the screen to form a projected image.

4 and 5, the light modulation device 220 may include a first liquid crystal panel 221, a second liquid crystal panel 222 and a third liquid crystal panel 223, the first liquid crystal panel 221 is used to modulate the first color light, such as green light; The second liquid crystal panel 222 is used to modulate the second color light, such as red light; the third liquid crystal panel 223 is used to modulate the third color light, such as blue light. The first liquid crystal panel 221 , the second liquid crystal panel 222 and the third liquid crystal panel 223 are all rectangular plate structures, and all have a length direction and a width direction. The second liquid crystal panel 222 and the third liquid crystal panel 223 can be disposed on opposite sides of the first liquid crystal panel 222 in the width direction, and the length directions of the first liquid crystal panel 221 , the second liquid crystal panel 222 and the third liquid crystal panel 223 are consistent.

The light-combining prism 230 is arranged between the first liquid crystal panel 221, the second liquid crystal panel 222 and the third liquid crystal panel 223, and the length of the light-combining prism 230 in the light emitting direction of the first liquid crystal panel 221 is adapted to that of the second liquid crystal panel. 222 and the width of the third liquid crystal panel 223 , the light combining prism 230 is used to combine the image light emitted by the first liquid crystal panel 221 , the second liquid crystal panel 222 and the third liquid crystal panel 223 into a beam of combined light.

Wherein, the light emitting direction of the first liquid crystal panel 221 is perpendicular to the first liquid crystal panel 221 . The length of the light-combining prism 230 on the light-emitting direction of the first liquid crystal panel 221 matches the width of the second liquid crystal panel 222 and the third liquid crystal panel 223, which can refer to the length of the light-combining prism 230 on the light-emitting direction of the first liquid crystal panel 221. The length is equal to the width of the second liquid crystal panel 222 and the third liquid crystal panel 223, or it may also mean that the length of the light-combining prism 230 in the light emitting direction of the first liquid crystal panel 221 is slightly smaller or slightly larger than that of the second liquid crystal panel 222 and the third liquid crystal panel 222. The width of the liquid crystal panel 223 .

The length of the light-combining prism 230 provided in this embodiment in the light emitting direction of the first liquid crystal panel 221 only needs to match the width of the second liquid crystal panel 222 and the width of the third liquid crystal panel 223, and does not need to match the width of the second liquid crystal panel 222 and the width of the third liquid crystal panel 223. The length of the third liquid crystal panel 223 can reduce the length of the light-combining prism 230 in the light emitting direction of the first liquid crystal panel 221 and the back focus of the projection lens 240 , making the entire projection system 200 more compact.

Still referring to FIG. 4 , in this embodiment, the light source 210 may be a white light source, specifically an LED or a laser fluorescent light source. The projection system 200 may further include a collecting device 250 , a polarizing device 260 and a dichroic prism 270 . The collecting device 250 , the polarizing device 260 and the dichroic prism 270 are sequentially arranged on the outgoing light path of the light source 210 and coaxial with the optical axis of the light source 210 . The collecting device 250 is used to collect the white light emitted by the light source 210 into parallel light, and the parallel light is polarized by the polarizing device 260 and enters the beam splitting prism 270 with a single polarization state. The dichroic prism 270 can be a dichroic dichroic prism, which has a first inclined plane and a second inclined plane that intersect each other and are perpendicular to each other. The green-transmitting red-anti-blue film is used to split the polarized light emitted by the polarizing device 260 into a first color light, a second color light and a third color light. This embodiment is described by taking the first color light as green light, the second color light as red light, and the third color light as blue light as an example.

The optical axis of the first liquid crystal panel 221 may be coaxial with the optical axis of the light source 210 , and the first color light may be directly incident on the first liquid crystal panel 221 after exiting the dichroic prism 270 for modulation. The optical axes of the second liquid crystal panel 222 and the third liquid crystal panel 223 are all perpendicular to the optical axis of the light source 210, and two groups of light deflection devices 100 can be arranged between the second liquid crystal panel 222 and the dichroic prism 270, the first group of light rays The optical axis of the light guide 110 of the refracting device 100 and the optical axis of the light source 210 are perpendicular to each other, the optical axis of the light guide 110 of the second group of light refracting device 100 and the optical axis of the light source 210 are parallel to each other, passing through the first group The continuous deflection of the second color light by the light deflection device 100 and the second group of light deflection devices 200 can guide the second color light emitted by the dichroic prism 270 to the second liquid crystal panel 222 for modulation. Two groups of light deflection devices 100 may also be arranged between the third liquid crystal panel 223 and the dichroic prism 270. Through the continuous deflection of the third color light by the two groups of light refraction devices 100, the third color light emitted by the dichroic prism 270 can be It is directed to the third liquid crystal panel 223 for modulation.

In this embodiment, detectors can be arranged between the first liquid crystal panel 221 and the dichroic prism 270, between the second liquid crystal panel 222 and the light deflection device 100, and between the third liquid crystal panel 223 and the light deflection device 100. The polarizer is used to analyze the light, so that the light incident on the liquid crystal panel is all polarized light with high purity.

In this embodiment, the collecting device 250 may include a conical homogenizing device 251 and a lens 252. The lens 252 may be a convex lens or a Fresnel lens. The light beam emitted by the light source 210 is collimated by the conical homogenizing device 251 and the lens 252 to form parallel light incident on the polarizer 260 . The polarizer 260 may be a polarizer, such as a polarizer, a Nicol prism, and the like. The light emitted by the collecting device 250 is unpolarized light, and the unpolarized light emitted by the collecting device 250 is incident on the polarizer and then exits the polarizer in a single polarization state.

In this embodiment, the projection system 200 may further include a pixel shifting device 280, which is arranged on the optical path between the light combining prism 230 and the projection lens 240, and is used to combine the combined light emitted by the light combining prism 230 along the Translating in a direction perpendicular to the optical axis and superimposing the synthetic light at different translation positions in time sequence can realize a small displacement of the image, thereby improving the display resolution.

The pixel shifting device 280 can be a transparent flat optical device using XPR (Pixel Shift Resolution System) technology, and the transparent flat optical device can control the rotation angle by current or voltage. Specifically, when the transparent plate of the pixel shifting device 280 rotates at a certain angle, the light passing through the transparent plate is refracted twice and translated as a whole, and the transparent plate stays at the rotated position for a predetermined time, and then rotates to other positions. In one image frame period, the pixel shifting device 280 can include 2 steady states or 4 steady states, and the image is split into 2 subframes or 4 subframes accordingly. Or 4 images are superimposed to form a high-resolution image in the brain. It can be understood that the pixel shifting device 280 may also include more stable states, so as to achieve higher resolution, and this embodiment does not limit the multiplication number of pixels.

In some other implementations, the pixel shifting device 280 can also be a liquid crystal birefringence device using E-shift (pixel expansion) technology, which controls the deflection angle of liquid crystal molecules through voltage, so that the light passing through the liquid crystal birefringence device The translation is performed to realize the effect of the overall pixel shift, and the effect is similar to that of the above-mentioned mechanically rotated pixel shift device, which will not be repeated here.

For the detailed structural features of the light bending device 100 , please refer to the related descriptions of the above-mentioned embodiments. Since the projection system 200 includes the light refraction device 100 in the above-mentioned embodiments, it has all the beneficial effects of the light refraction device 100 , so details are not repeated here.

The above-mentioned embodiments only express several implementation modes of the present application, and the description thereof is relatively specific and detailed, but should not be construed as limiting the patent scope of the present application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the scope of protection of the patent application should be based on the appended claims.

Claims (10)

1. A light refraction device, characterized in that, comprising: light guides; and The folding member is arranged on the outgoing light path of the light guiding member, the folding member includes a first transflective element, a second transflective element and a reflective element, the first transflective element and the second transflective element The reflective element is connected at an angle, and the reflective element is connected between the first transflective element and the second transflective element; both the first transflective element and the second transflective element are used to transmit incident light with an angle smaller than the first angle value and within the set wavelength range, and reflect light with an incident angle greater than the second angle value and within the set wavelength range, wherein the first angle value is smaller than the second angle value ; The light guide element is used to guide the light to be incident on the first transflective element at an incident angle smaller than the first angle value, and the second transflective element is used to transmit the incident light at an incident angle smaller than the first angle value Angle of light incident on the second transflective element. 2. The light refraction device according to claim 1, characterized in that, a part of the light transmitted by the first transflective element is incident on the reflective element, and after being reflected by the reflective element, it is larger than the first transflective element. The incident angle of two angle values is incident on the first transflective element, and after the first transflective element is reflected, it is incident on the second transflective element at an incident angle smaller than the first angle value and then emerges. . 3. The light refraction device according to claim 1, wherein a part of light transmitted by the first transflective element is incident on the second transflective element at an incident angle greater than the second angle value, It is reflected by the second transflective element to the reflective element, and is incident on the second transflective element at an incident angle smaller than the first angle value after being reflected by the reflective element, and then emerges. 4. The light refraction device according to any one of claims 1-3, wherein the first transflective element comprises a first optical multilayer interference film, and the second transflective element comprises a second optical The multilayer interference film, the first optical multilayer interference film and the second optical multilayer interference film are both used to transmit the light whose incident angle is smaller than the first angle value and conforms to the set wavelength range, and reflect Light rays whose incident angle is larger than the second angle value and conform to the set wavelength range. 5. The light refraction device according to claim 4, wherein the first transflective element further comprises a first transparent sheet, and the first transparent sheet is coated with the first optical multilayer interference film; The second transflective element also includes a second transparent sheet coated with the second optical multilayer interference film; the reflective element is connected to the first transparent sheet and the second transparent sheet. Mirrors between transparent sheets. 6. The light refracting device according to claim 1, wherein the light guide is a hollow conduit. 7. The light refraction device according to claim 1, characterized in that, one end of the light guide facing the first transflective element is provided with an exit end surface, and the exit end surface is connected to the first transflective element. element. 8. The light refraction device according to claim 7, characterized in that, the shape of the outgoing end surface is consistent with the incident surface of the first transflective element, and the shape of the outgoing end surface is consistent with that of the first transflective element The plane of incidence coincides. 9. The light refraction device according to claim 1, wherein the optical axis of the first transflective element is parallel to the optical axis of the light guide, and the optical axis of the second transflective element The optical axis of the first transflective element is perpendicular to each other, and the normal line of the reflective element forms an included angle of 45° with the optical axis of the first transflective element. 10. A projection system, characterized in that it comprises a light source, a light modulation device, a light combining prism, and the light refraction device according to any one of claims 1-9, the light refraction device is arranged on the light source The outgoing light path of the light source is used to guide the outgoing light of the light source to the light modulation device, the light modulation device is used to modulate the light to form image light carrying image information, and the light combining prism is used to synthesize the image Light.

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