WO2011103807A1

WO2011103807A1 - Image projection system and optical path synthesizer thereof

Info

Publication number: WO2011103807A1
Application number: PCT/CN2011/071273
Authority: WO
Inventors: 黄河·H
Original assignee: 上海丽恒光微电子科技有限公司
Priority date: 2010-02-26
Filing date: 2011-02-24
Publication date: 2011-09-01
Also published as: CN102591020A; CN102591020B

Abstract

An image projection system and an optical path synthesizer thereof are provided in the embodiments of the present invention. The optical path synthesizer includes: an optical element, which at least includes a first incidence surface for receiving a first light beam, a second incidence surface for receiving a second light beam, and an output surface for emitting the first light beam and the second light beam along a first direction; a total reflector, provided in the interior of the optical element, which includes a transmission surface for receiving the first light beam incident along the first direction and transmiting the first light beam for transmission along the first direction and a reflection surface for receiving the second light beam incident along the second direction and reflecting the second light beam for transmission along the first direction. The optical synthesizer of the present invention can effectively synthesize the parallel light beams from two independent light sources in different directions into illumination light beam in a single direction, thereby improving the imaging brightness of the image projection system.

Description

Image projection system and optical path synthesizer thereof

Embodiments of the present invention relate to optical instrument technology, and more particularly to an image projection system and an optical path synthesizer. Background technique

The image projection system is used for magnifying and projecting images, and is widely used in people's daily life, such as: projection systems built in digital cameras, handheld projectors, and the like. With the increasing use of its applications, the related technology of image projection systems has also been greatly developed.

Image projection systems typically use a microdisplay imager as an optical spatial modulator that first parallelizes and homogenizes the light from the source, and then directs the illumination beam to the microdisplay imager to project the image onto the screen.

FIG. 1 is a schematic structural view of an image projection system in the prior art. The image projection system includes: a light source 11, an illumination system 13, a mirror 15, a beam splitter 19, a display substrate 17, a projection lens 12, and a receiving screen 14. The display substrate 17 can be displayed in a reflective display mode by reflecting incident light. Specifically, the display substrate 17 may be a Liquid Crystal on LCD (LCOS) display. The beam splitter 19 can be a Total Internal Reflection (TIR) prism, and the beam splitter 19 includes a first prism and a second prism for separating the illumination beam and the illumination emitted by the illumination system 13 via the mirror 15. The modulated beam emitted by the substrate 17. The structure of the existing image projection system can also be found in the Chinese patent application with the publication number CN101819327A.

The image projection system works as follows: Light emitted by the light source 11 is projected into the illumination system 13; the illumination system 13 collimates the light emitted by the light source 11 to form a parallel illumination beam; the parallel illumination beam passes through the reflection of the mirror 15 and enters The beam splitter 19; the parallel illumination beam is reflected on the reflection surface of the first prism of the beam splitter 19, and then the reflected light is projected onto the display substrate 17, after being displayed The substrate 17 is modulated to form a modulated beam, and the modulated beam enters the beam splitter 19 again. The modulated beam passes through the beam splitter 19 without change, and is then projected onto the projection lens 12. The projection lens 12 amplifies the displayed image and enlarges the displayed image. The image is projected onto the receiving screen 14.

In the prior art, how to improve the brightness of the projected output light passing through the microdisplay imager and the projection lens is one of the research directions. However, the image projection system in the prior art uses a single direction white light source or a R\G\B tricolor lamp hybrid light source, and it is not possible to mix a plurality of light sources to simultaneously illuminate a display substrate. This causes the projected luminous flux to be limited by the luminous efficiency of the light source and cannot meet the requirements of a high brightness projection system. In addition, simply coupling or mixing the light sources of the array structure to produce a single, collimated, and uniformly colored beam will change the ductility and further exacerbate the complexity of the system structure, affecting the illumination of the display substrate, so Improvements in lighting brightness are limited.

Therefore, in order to improve the brightness of the projection system, how to couple or mix a plurality of light beams, especially mixing light beams of similar wavelengths or spectra from a plurality of independent light sources, is a problem to be solved in the prior art. Summary of the invention

Embodiments of the present invention provide an image projection system and an optical path synthesizer for synthesizing a plurality of light source beams to improve brightness of an image projection system.

An embodiment of the present invention provides an optical path synthesizer, including:

An optical device comprising at least a first incident surface for receiving the first light beam, a second incident surface for receiving the second light beam, and an exit surface for emitting the first light beam and the second light beam in the first direction; And disposed inside the optical device, and the total reflector includes:

a transmissive surface for receiving the first light beam incident in the first direction and transmitting the first light beam to be transmitted in the first direction;

a reflecting surface for receiving the second light beam incident in the second direction and reflecting the second light beam to be transmitted in the first direction.

Embodiments of the present invention also provide an image projection system including a light source, a display substrate, and a projection a lens and a receiving screen, wherein: the optical path synthesizer provided by the embodiment of the invention is further included; the light source includes a first light source and a second light source, wherein the first light source is configured to emit the first light beam toward the first incident surface The second light source is configured to emit a second light beam toward the second incident surface; the first light beam and the second light beam exit from the exit surface in a first direction to form an illumination light beam.

The optical path synthesizer provided by the embodiment of the invention can effectively combine the parallel light beams from the independent light sources in two directions into a single direction illumination beam, thereby realizing the mixing of the light beams in the two directions, and improving the luminous flux entering the display substrate, which has a multiplication. The brightness of the light enhances the brightness of the image projection system. The total reflector of the optical path synthesizer is integrated inside the optical device, which can realize transmission and reflection at the same time, and the space required for the optical path is small, so that the integration of the optical path synthesizer can be improved, the size can be reduced, and the image can be made. The projection system is miniaturized. DRAWINGS

1 is a schematic structural view of an image projection system in the prior art;

2 is a schematic structural diagram of an optical path synthesizer according to Embodiment 1 of the present invention;

3 is a schematic structural diagram of an optical path synthesizer according to Embodiment 2 of the present invention;

4 is a schematic structural diagram of an optical path synthesizer according to Embodiment 3 of the present invention;

FIG. 5 is a schematic structural diagram of an optical path synthesizer according to Embodiment 4 of the present invention; FIG.

6A is a schematic structural diagram of an image projection system according to Embodiment 5 of the present invention;

6B is a schematic enlarged structural view of a display substrate according to Embodiment 5 of the present invention;

7 is a schematic structural diagram of an image projection system according to Embodiment 6 of the present invention;

8 is a schematic structural diagram of an image projection system according to Embodiment 7 of the present invention;

9 is a schematic structural diagram of an image projection system according to Embodiment 8 of the present invention;

FIG. 10 is a schematic structural diagram of an image projection system according to Embodiment 9 of the present invention; FIG.

11 is a schematic structural diagram of an image projection system according to Embodiment 10 of the present invention;

FIG. 12 is a schematic structural diagram of an image projection system according to Embodiment 11 of the present invention.

The reference numerals in the figure indicate: 11-light source 12-projection lens 13-illumination system

14-Receive screen 15-mirror 17-display substrate

19-beam splitter 21 - first axis 22 - second axis

28-Base lens shaft 41-Micro display imaging plane 42-Base lens surface

58-illumination beam 59-modulation beam 101-first beam

102 - second beam 103 - first direction 104 - second direction

105 - third direction 106 - modulation direction 107 - incident direction

108-projection direction 110-first light source 120-second light source

201-first incident surface 202-second incident surface 203-exit surface

204-transmissive surface 205-reflecting surface 210-first optical device

220-Second Optics 230 - Total Reflector 300-Receive Screen

400-mirror 510 - first collimating unit 520 - second collimating unit

600-display substrate 610-reflective liquid crystal modulation device 700-beam splitter

800-projection lens

detailed description

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is a partial embodiment of the invention, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

Embodiments of the present invention provide an optical path synthesizer, which may be referred to as a dual optical path synthesizer or a parallel illumination synthesizer according to its function. The optical path synthesizer includes optics and a total reflector. Wherein the optical device includes at least a first incident surface for receiving the first light beam, a second incident surface for receiving the second light beam, and an exit surface for exiting the first light beam and the second light beam in the first direction; Reflector setting Placed inside the optics, and the total reflector includes a transmissive surface and a reflective surface. The transmissive surface is configured to receive the first light beam incident in the first direction and transmit the first light beam to transmit in the first direction; the reflective surface is configured to receive the second light beam incident in the second direction and reflect the second light beam to the first Direction transfer. The beam emerging from the exit face can be used as a projection illumination beam for an image projection system.

According to the technical solution of the embodiment of the present invention, the first beam and the second beam incident in different directions can be unified and transmitted in the first direction, and can be effectively improved when the optical path synthesizer is integrated in the image projection system. The brightness of the projected image.

In an embodiment of the invention, the optical device may be any medium entity capable of transmitting a light beam, typically a transparent medium capable of efficiently transmitting a light beam, such as glass, plastic, or the like. A total reflector integrated inside the optics is used to unify the beam direction by different treatments of incident light in different directions within the optics, specifically by using total reflection of the beam to change the direction of beam propagation.

Preferably, the total reflector has a refractive index that is less than the refractive index of the optical device such that total reflection is achieved on the reflective surface and transmission is achieved on the transmission surface. Alternatively, transmission and total reflection can also be achieved by adding corresponding antireflection or total reflection films to the transmissive and reflective surfaces.

The first beam and the second beam can be made by designing a reasonable fit of various angles, such as the angle between the transmissive surface and the reflecting surface, the angle between the first direction and the second direction, and a reasonable fit with the total reflection angle. Unify to exit in the first direction. The magnitude of the total reflection angle can be determined by selecting the refractive index relationship of the optical device and the total reflector.

The miniaturization of the image projection system is its development trend. In order to minimize the size of the optical path synthesizer and minimize the size required for the incident light source, it is preferable to make the reflective surface and the transmissive surface as close as possible to the first beam and The optical path of the second beam reuses the space within the optic. For example, the reflecting surface can be arranged in parallel with the transmitting surface. Preferably, the reflecting surface and the transmitting surface are disposed in parallel to form a flat layered total reflector, and the first light beam is transmitted in the same manner as the second light beam.

The integrated optics and total reflector scheme, preferably the optics, includes a first optic and a second optic, the total reflector being sandwiched between the first optic and the second optic. The optics can be glass or plastic prisms. The total reflector is preferably formed in the first optical device and The air gap between the two optics may generally be such that the first optical device and the second optical device are bonded to each other to form a thin air layer therebetween.

The refractive indices of the materials employed by the first optical device and the second optical device may be the same or different. The refractive index of the full reflector is smaller than the refractive index of the optical device, and total reflection can be formed on the reflecting surface.

There are various embodiments for realizing the optical path synthesizer of the present invention. The structure and working principle of the optical path synthesizer will be explained in detail below with reference to the embodiments.

Embodiment 1

FIG. 2 is a schematic structural diagram of an optical path synthesizer according to Embodiment 1 of the present invention. The basic structure of the optical path synthesizer includes an optical device and a total reflector 230.

The optical device includes a first incident surface 201 for receiving the first light beam 101, a second incident surface 202 for receiving the second light beam 102, and a first light beam 101 and a second light beam 102 for exiting in the first direction 101. Exit surface 203. The first beam 101 is specifically a beam of light transmitted along a first axis 21 in a first direction 103. The second beam 102 is specifically a beam of light that is transmitted along a second axis 22 in the second direction 104. The first beam 101 and the second beam 102 can have different, similar or uniform wavelengths or frequencies.

The total reflector 230 is disposed inside the optical device, and the total reflector 230 includes a transmissive surface 204 and a reflective surface 205. The transmissive surface 204 is for receiving the first light beam 101 incident in the first direction 103 and transmitting the first light beam 101 to the first direction 103; the reflecting surface 205 is for receiving the second light beam 102 incident in the second direction 104 and reflecting The second beam 102 is transmitted in a first direction 103.

In this embodiment, the refractive index of the total reflector 230 is smaller than the refractive index of the optical device; the angle between the normal of the transmission surface 204 and the first direction 103 is the transmission angle, and the transmission angle is smaller than the total reflection critical angle of the transmission surface 204. The first light beam 101 can be transmitted through the transmission surface 204; the angle between the normal line of the reflection surface 205 and the second direction 104 is a reflection angle, and the reflection angle is greater than or equal to the total reflection critical angle of the reflection surface 205, ensuring the second Light beam 102 can be totally reflected by reflective surface 205.

In this embodiment, it is preferable that the reflecting surface 205 is disposed in parallel with the transmitting surface 204, and the angle between the transmitting surface 204 and the reflecting surface 205 of the total reflector 230 and the first axis 21 is denoted by α, and the second axis 22 The angle between them is denoted by β.

The total reflector 230 may be an optical component integrated inside a monolithic optical device, as shown in FIG. 2 of the present embodiment. For the sake of clarity, the portion of the optical device on the side of the transmissive surface 204 is referred to as the first optical device 210. A portion located on the side of the reflecting surface 205 is referred to as a second optical device 220. In practical applications, the optical device may also be formed by two separate devices, that is, a separate first optical device 210 and a second optical device 220. The total reflector 230 is clamped between the first optical device 210 and the second device. Between optics 220. When the refractive indices of the first optical device 210 and the second optical device 220 are the same, α and β are not equal, and are acute angles, which are not equal to an integral multiple of 45°, in order to satisfy the requirements of the transmission angle and the reflection angle.

The total reflector 230 may be an air gap formed between the first optical device 210 and the second optical device 220, whether it is a unitary structure or a separate structure. Alternatively, other materials having a lower refractive index than the optical device may be used. The refractive indices of the materials used by the first optical device 210 and the second optical device 220 may be the same or different. An anti-reflection film is preferably provided on the transmission surface 204 of the first optical device 210 to increase the amount of transmission.

In this embodiment, the cross-sectional shapes of the first optical device 210 and the second optical device 220 are both right-angled trapezoids, and the two right-angled trapezoids are combined into a rectangular shape. The cross section refers to a plane parallel to the first direction 103 and the second direction 104. The first direction 103 and the second direction 104 are incident directions that do not overlap each other and are not parallel, as long as the above-described transmission and reflection conditions are satisfied. In the present embodiment, the first direction 103 and the second direction 104 are preferably perpendicular to each other.

The working principle of the optical path synthesizer will be specifically described below with reference to FIG.

The first light beam 101 emitted by the first light source 110 is transmitted through the transmission surface 204 of the total reflector 230, enters the second optical device 220, and then exits from the exit surface 203 in the first direction 103; is emitted by the second light source 120. The second light beam 102 is totally reflected by the reflecting surface 205 of the total reflector 230, reflected to the first direction 103, and emitted from the exit surface 203. The transmitted first beam 101 and the totally reflected second beam 102 are ultimately combined into an illumination beam that is transmitted in a first direction.

Embodiment 2 FIG. 3 is a schematic structural diagram of an optical path synthesizer according to Embodiment 2 of the present invention. The difference between this embodiment and the first embodiment is that the optical device includes the first optical device 210 and the second optical device 220, and the second optical device 220 is polygonal, and the second light beam 102 does not directly enter the reflective surface along the second direction 104. 205 is incident on the reflective surface 205 after being internally reflected by the second optical device 220.

The technical solution of this embodiment is specifically as follows: the first optical device 210 has a transmission edge forming a transmission surface 204; the second optical device 220 is a polygon, and the polygon includes at least a second incident edge, a total reflection edge, a first reflection edge, and a second a reflecting edge and an exiting edge; a total reflecting edge as the reflecting surface 205, and a total reflector 230 is sandwiched between the transmitting edge; and a second incident side as the second incident surface 202 for receiving the second beam incident in the third direction 105 a first reflective edge and a second reflective edge are configured to reflect the second light beam 102 incident from the second incident edge in the second direction 104 to the total reflection edge; the exit edge as the exit surface 203 for use in the first direction The first light beam 101 transmitted through the transmission 103 and the second light beam 102 reflected in the first direction 103 are emitted.

By properly selecting the materials of the optics and the total reflector, and properly designing the angles of the various sides of the optics, the transmission paths of the first beam and the second beam can satisfy the above requirements.

First, in the embodiment, the refractive indices of the materials used by the first optical device and the second optical device in the embodiment may be the same; and the angle between the first direction and the normal of the reflective surface is greater than or equal to the first The total reflection critical angle of the two optical devices, the surface of the first optical device and the second optical device are disposed with an anti-reflection film. Thereby, the first light beam is transmitted on the transmission surface, and the second light beam is totally reflected on the reflection surface. Alternatively, this embodiment may also set the refractive indices of the materials used for the first optical device and the second optical device to be different. And setting an angle between the first direction and the normal of the reflective surface is smaller than a total reflection critical angle of the first optical device; an angle between the first direction and the normal of the reflective surface is greater than or equal to a total reflection threshold of the second optical device angle.

For the other sides of the polygonal second optical device, the angle between the normal of the first reflecting edge and the third direction is preferably greater than or equal to the total reflection critical angle of the first reflecting edge; the normal of the second reflecting edge The angle between the second direction and the second direction is preferably greater than or equal to the total reflection critical angle of the second emission side, so that the second beam can be internally totally reflected on the first reflection side and the second reflection side to reduce light loss. the amount. Alternatively, in order to increase the internal reflectance, the first reflective side and the second reflective side may be coated with a total reflection film to ensure reflection efficiency and reduce light loss.

In the technical solution of the embodiment, by internally reflecting the second light beam, the second light beam can be allowed to enter in a third direction different from the second direction and the first direction, and the requirement for the position of the light source is more flexible, further expanding the optical path synthesis. And the possibility of image projection system design. The first direction and the third direction do not overlap or are not parallel to each other, and preferably the first direction and the third direction are perpendicular to each other. The technical solution of the present embodiment can use the optical path synthesizer to unify the two beams incident in the mutually perpendicular direction to the same direction.

There may be a plurality of shapes of the first optical device and the second optical device that satisfy the above requirements. In order to increase the incident rate of the first light beam, it is preferable to set the first incident side of the first optical device to be perpendicular to the first direction, and the exit side of the second optical device is perpendicular to the first direction, that is, the first incident side is parallel to the exit side and positive For the setting, the first beam can be transmitted and transmitted. When the first direction and the third direction are perpendicular to each other, it is preferable to provide the second incident side of the second optical device in parallel with the first direction to reduce the amount of reflection of the substantially incident second light beam on the second incident side.

As shown in FIG. 3, the second optical device 220 is specifically a polygonal prism, which may also be referred to as a polygonal prism. The first optical device 21 0 may specifically be a right-angle prism whose cross-sectional shape is a right-angled triangle, and the right-angled triangle includes a first right-angled side, a second right-angled side, and a hypotenuse, and the oblique side is a transmissive side. The first orthogonal side of the right triangle, i.e., the first incident side perpendicular to the first direction 103, serves as the first incident surface 201; and the transmissive side serves as the transmissive surface 204 of the total reflector 230. In order to reduce the overall volume of the optical path synthesizer, it is preferable that the cross-sectional shape of the right-angle prism and the polygonal prism is a right-angled pentagon, and the right-angled triangles cooperate to form a right angle of the pentagon.

In the present embodiment, as shown in FIG. 3, the optical path synthesizer is specifically formed by combining hexagonal prisms ABCDEF and right-angle prisms E 'F 'G '. In this embodiment, when the hexagonal prism ABCDEF and the material of the right-angle prism E 'F 'G ' are simultaneously parameterized, the inclined surface of the right-angle prism E 'F 'G ' is coated with an anti-reflection film. The refractive index of BK7-s cho tt or K9-CDGM glass is 1.516, so the transmissive surface 204 and reflection are relative to the total reflector 230 of the air layer. The critical angle of total reflection of face 205 is 41.275°.

The cross-sectional shape of the hexagonal prism ABCDEF is a convex hexagonal shape, and the hexagonal prism ABCDEF includes a surface AB (corresponding to the exit edge), a surface BC (corresponding to the first reflection edge), and a surface CD (corresponding to the second reflection edge) in clockwise order. ), face DE, face EF (corresponding to total reflection edge) and face FA (corresponding to second incident edge). Wherein, the face AB and the face DE are parallel, and the face FA and the face AB are perpendicular to each other, that is, the face FA and the apex angle FAB of the face AB are right angles. The other apex angles of the hexagonal prism ABCDEF are: apex angle ABC 135.00°, apex angle BCD 86.28°, apex angle CDE 138.73 °, apex angle DEF 138.725. The apex angle EFA is 131.545 °. In addition, the face BC and the face CD of the hexagonal prism ABCDEF are plated with a full reflection film, and the light in the hexagonal prism ABCDEF can be reflected into the hexagonal prism ABCDEF.

The right-angle prism E'F'G' includes a face F'E' (corresponding to the transmission side), a face E'G' (corresponding to the first incident side) and a face G'F' in a clockwise direction, wherein the face G' F' and face E'G' are perpendicular to each other, that is, the apex angle E'G'F' is a right angle. The right angle prism E'F'G' has a top angle G'F'E' of 48.725° and an apex angle F' E'G' of 41.275. .

The face EF of the hexagonal prism ABCDEF is attached to the face E'F' of the right-angle prism E'F'G'. Specifically, there is an air layer, the face EF and the face E' between the face EF and the face E'F'. The periphery of the bonding surface of F' is bonded together by adhesive tape, and the thickness of the air layer is uniform as a total reflector 230. In the present embodiment, the surface EF is the same as the surface E'F'. Here, the same meaning is that the surface EF and the surface E'F' are the same in shape and size, but the present invention is not limited thereto. The face E'G' of the right-angle prism E'F'G' and the face DE of the hexagonal prism ABCDEF are on one face, that is, the face E'G' of the right-angle prism E'F'G' and the face AB of the hexagonal prism ABCDEF Parallel, the face G'F' of the right-angle prism E'F'G' and the face FA of the hexagonal prism ABCDEF are on one face.

In the embodiment in which the face EF is different from the face E'F', the face E'G' of the right-angle prism E'F'G' is parallel to the face DE of the hexagonal prism ABCDEF, and the face G of the right-angle prism E'F'G' 'F' is parallel to the face FA of the hexagonal prism ABCDEF.

The operation principle of the optical path synthesizer of this embodiment will be specifically described below with reference to FIG.

The first incident light emitted by the first light source 110 enters the optical path combiner in the first direction 103 by the first incident surface 201 of the optical path combiner and exits the exit surface 203 of the optical path combiner in the first direction 103. Shoot out. The first incident light, i.e., the first light beam 101, enters the optical path combiner from the surface E'G' in a first direction 103 perpendicular to the face E'G' of the right-angle prism E'F'G'. Since the incident angle is zero degrees, the light entering the right-angle prism does not change direction and directly reaches the face E'F'. The incident angle of the first beam 101 at the face E'F' is equal to 41.275 °, since the antireflection film is disposed on the face E'F', and there is an air gap between the E'F' face of the right angle prism and the EF face of the hexagonal prism. Therefore, the light from E'F' can enter the air medium, then enter the EF surface of the hexagonal prism, and then exit from the face AB of the hexagonal prism ABCDEF. Since the face AB is parallel to the face E'G', the first incident light is vertical. The ground is transmitted to the face AB and then exits in the first direction 103. Alternatively, when the antireflection film is not disposed on the surface E'F', the incident angle of the first light beam 101 at the surface E'F' may be less than 41.275 by designing the prism angle. That is, less than the critical angle of total reflection, to achieve transmission of the first beam 101 from the plane E'F'.

The second incident light emitted by the second light source 120 enters the optical path combiner in the second direction 104 by the second incident surface 202 of the optical path combiner, reflects within the optical path combiner, and exits from the exit surface 203 in the first direction 103. . The second incident light is the second light beam 102 that enters the second optical device 220 from the face FA along a third direction 105 perpendicular to the face FA of the hexagonal prism ABCDEF. The second incident light has an incident angle of 45° on the face BC. Since the face BC is plated with a total reflection film, or the incident angle is greater than the total reflection critical angle of the face BC, the second incident light is Total reflection. After the reflection, the first reflected light is formed, and the first reflected light is projected onto the surface CD at an incident angle of 41.28°, because the surface CD is plated with a total reflection film, or the incident angle is larger than the total reflection critical angle of the surface CD, The first reflected light is totally reflected at the surface CD, and is reflected to form a second reflected light. The second reflected light is projected onto the surface EF at 41.275°. Since the material of the hexagonal prism ABCDEF is BK7_schott or K9-CDGM glass, the total reflection critical angle of the incident glass from the material glass is 41.275°, so the second reflected light is A full emission occurs at the face EF, and after the total reflection, a third emitted light is formed, and the third emitted light is projected onto the face AB in the first direction 103. The third emitted light then exits in the first direction 103.

It can be seen that the first incident light incident on the optical path synthesizer in the first direction 103 and the second incident light incident on the optical path synthesizer in the third direction 105 are both in the first direction 103 when exiting from the optical path synthesizer Exit. It should be noted that only the positions where the light needs to pass are defined in the respective faces of the right-angle prism and the hexagonal prism, and the shapes of the other faces need not be strictly limited. among them:

When the second incident light enters the second optical device 220 from the face FA in the third direction 105 perpendicular to the face FA of the hexagonal prism ABCDEF, specifically, the face BC is incident on the projection area on the face FA in the third direction 105, that is, from The high region of the face FA is partially incident. The light entering the second optical device 220 from the low portion of the surface FA cannot be projected onto the surface BC. The light cannot be emitted in the first direction 103 according to the designed angle, and the low portion outside the high portion is prohibited from passing light. region. Preferably, the light incident region of the second incident light is limited to the upper portion of the face FA by setting the position of the light source or applying a light shielding layer at the low portion.

For the second incident light, total reflection occurs on the EF plane, and then exits from the AB plane in the first direction 103, and the first incident light enters from the plane E'G' and also exits from the plane AB. Preferably, only the projection surface of the surface EF and the surface E'F' plane along the first direction 103 on the surface AB is the exit surface 203, and the non-projection area on the surface AB cannot be normally emitted, and the shielding layer can be used to limit other The area is the area where the light is prohibited from passing through.

When the first incident light enters the first optical device 210 from the surface E'G', only the projection surface of the surface EF along the first direction 103 on the surface E'G' is the first incident surface 201 of the actual meaning. The first incident light incident on the projection surface can be effectively combined with the second incident light reflected on the EF surface. Therefore, it is preferable to limit the incident area of the first incident light to the projection area of the plane EF on the plane E'G', and accordingly, the plane DE of the hexagonal prism is the light-inhibiting region.

It should be noted that the present embodiment provides an example of incident light and a prism, but those skilled in the art can understand that the present invention is not limited thereto, wherein:

This embodiment gives various specific angles of the prism. The incident angle of the second incident light on the plane EF is exactly equal to the critical angle of total reflection (in order to cause total reflection, the angle of the hexagonal prism must be accurately set at the time of design). In other embodiments, the incident angle of the second reflected light on the surface EF is greater than the critical angle. The person skilled in the art can perform the angle between the hexagonal prism surface EF and the third direction according to the refractive index of the selected material. Designed to cause total reflection of the second reflected light on the surface EF and to make the total reflection shape The third reflected light is emitted in the first direction.

In this embodiment, the first incident light and the second incident light are also set to enter the optical path synthesizer perpendicularly to each other, but the angle between the first incident light and the second incident light may be other angles. A person skilled in the art can replace, modify and modify accordingly according to the above embodiments.

In this embodiment, the hexagonal prism ABCDEF and the right-angle prism E'F'G' are made of the same material, that is, the refractive index is the same, and the critical angle of total reflection with air is also the same. Therefore, an anti-reflection film is disposed on the inclined surface E'F' of the right-angle prism, so that the second incident light is totally reflected on the surface EF, and the first incident light is transmitted on the inclined surface E'F' of the right-angle prism, and For the implementation of the material of the hexagonal prism ABCDEF and the right-angle prism E'F'G', in order to pass the first incident light through the slope E'F' of the right-angle prism into the hexagonal prism ABCDEF, the first direction and the surface E'F The angle of the 'normal line' needs to be smaller than the total reflection critical angle of the right-angle prism E'F'G' to avoid total reflection of the incident light in the first direction on the surface E'F'.

Embodiment 3

4 is a schematic structural diagram of an optical path synthesizer according to Embodiment 3 of the present invention. The difference between this embodiment and the second embodiment is that the overall shape of the optical path synthesizer formed by combining the first optical device 210 and the second optical device 220 is not Regular polygons. In this embodiment, the first optical device 210 is still a right-angle prism, and the second optical device 220 is a pentagonal prism. The technical solution can still meet the optical transmission requirements as described in the second embodiment.

The shape of the first optical device 210 and the second optical device 220 in the optical path synthesizer is not the same as the fourth embodiment.

FIG. 5 is a schematic structural diagram of an optical path synthesizer according to Embodiment 4 of the present invention. The embodiment may be based on any of the foregoing embodiments. Specifically, the optical path synthesizer includes a plurality of sets of optical devices and total reflections arranged in the first direction 103. And the first incident surface 201 and the exit surface 203 of the adjacent two optical devices are disposed opposite to each other such that the outgoing light of the previous optical device can be incident as the first light beam into the first incident surface 201 of the next optical device.

This embodiment is specifically described by taking the optical path synthesizer shown in the second embodiment as an example, but the field The skilled person can understand that the optical path synthesizer of the first embodiment or the third embodiment, and the optical path synthesizer provided by other embodiments of the present invention can be similarly arranged.

With the technical solution of the present embodiment, when the second light beam 102 is emitted by the plurality of second light sources 120, or the second light beam 102 in the form of a surface light source is emitted, it can be unified to be transmitted in the first direction 103. The number of optical combiners can be two or more, depending on actual needs.

The technical solution of the embodiment increases the luminous flux of the second light beam. However, since there are a plurality of optical elements in Fig. 5, light is lost in the optical elements. Therefore, when the optical elements exceed a certain number, even if the light source is increased more, the light flux received at the display substrate cannot be increased. Those skilled in the art can select an appropriate number of components as needed in practical applications.

The optical path synthesizer provided by the embodiments of the present invention has the advantages of:

The optical path synthesizer can effectively combine the parallel beams from the independent light sources in two directions into a single direction illumination beam, and actually make the beam transmission direction in one direction unchanged, and the beam transmission direction in the other direction pass the reflection. The change, in turn, achieves mixing of the beams in the two directions, increasing the luminous flux entering the display substrate, and having a multiplied brightness, thereby improving the brightness of the image projection system.

The total reflector of the optical path synthesizer is integrated inside the optical device, and substantially realizes both transmission and reflection, and the space required for the optical path is small, so that the integration of the optical path synthesizer can be improved, and the size can be reduced, thereby enabling The image projection system is miniaturized.

Embodiments of the present invention also provide an image projection system including a light source, a display substrate, a projection lens, and a receiving screen, and an optical path synthesizer provided by any of the embodiments of the present invention. The light source specifically includes a first light source for emitting a first light beam toward the first incident surface, and a second light source for emitting the second light beam toward the second incident surface; the first light beam and the second light beam are emitted from the first light source The face exits in a first direction to form an illumination beam. The first source and the second source can be any source used by the image projection system, such as a light emitting diode (LED) or a laser or arc lamp.

The first light source and the second light source respectively emitted by the first light source and the second light source pass through the optical path synthesizer Emitting in the first direction to form an illumination beam; the illumination beam in the first direction is incident on the display substrate, and after the modulation processing of the display substrate, the image modulated beam carrying the image information is formed to be emitted in the modulation direction; the modulated beam is directed to the projection The lens forms a projection beam along the projection direction through the projection lens, and projects the image on the receiving screen.

With the technical solution of the embodiment of the invention, the beams of two different incident directions can be unified to a single exit direction, thereby improving the brightness of the image projection system.

The image projection system using the optical path synthesizer can be embodied in various forms. For example, the display substrate can be classified into a reflective display substrate and a transmissive display substrate. The modulation direction of the reflective display substrate is generally parallel and opposite to the incident direction of the display substrate; the modulation direction of the transmissive display substrate generally overlaps with the incident direction.

When selecting a reflective display substrate, the image projection system usually also adds a beam splitter (or beam splitter) to change the direction of the light path. The optical splitter is disposed between the optical path synthesizer, the reflective display substrate and the projection lens, and is configured to receive the illumination beam emitted by the optical path synthesizer, and direct the illumination beam to the reflective display substrate, and the spectrometer simultaneously emits the modulation of the reflective display substrate. The beam is transmitted through the projection lens.

The display substrate can be implemented using a microdisplay imager. The microdisplay imager may be composed of a plurality of optically modulated pixels arranged in an array in the microdisplay imaging plane for optical spatial modulation based on the microdisplay imaging surface, the optical modulation pixels receiving the illumination beam in the incident direction, and generating An image carrying image information transmitted along the modulation direction modulates the beam.

The optically modulated pixels can be any reflective or transmissive optical spatial modulation device. The reflective optically modulated pixels may specifically be reflective microelectromechanical optically modulated pixels. The reflective microelectromechanical optical modulation pixel may specifically be a Deformable Micromirror Device (DMD), a Deformable Interference Modulation Device or a Reflective Liquid Crystal Modulation Device. The reflective liquid crystal modulation device is, for example, LCOS.

The transmissive optical modulation pixel may specifically be a transmissive liquid crystal modulation device or the like.

According to the requirements of the light source direction and the projection direction in the image projection system, there are various scheme groups. The relative positional relationship of the light source, the optical path synthesizer, the display substrate, the projection lens, and the receiving screen will be described in detail below by way of specific embodiments.

Embodiment 5

6A is a schematic structural diagram of an image projection system according to Embodiment 5 of the present invention. The image projection system includes a light source, a display substrate 600, a projection lens 800, and a receiving screen (not shown), and further includes optical path synthesis provided by the present invention. Device. The light source includes a first light source 110 and a second light source 120. The first light source 110 is configured to emit a first light beam 101 toward the first incident surface 201. The first light beam 101 is specifically along the first axis 21 in the first direction 103. The transmitted beam. The second source 120 is for emitting a second beam 102 toward the second entrance surface 202, the second beam 102 being specifically a beam of light transmitted along a second axis 22 in the second direction 104.

In this embodiment, the optical path synthesizer adopts the technical solution of the first embodiment. The display substrate 600 is specifically a reflective display substrate, and is composed of a plurality of reflective optical modulation pixels 610 arranged in an array form, as shown in FIG. 6B. Reflective light modulating pixels 610 are disposed on microdisplay imaging plane 41. The microdisplay imager receives the illumination beam 58 and forms an image modulated beam 59 that exits in the modulation direction 106.

In this embodiment, the reflective display substrate 600 is used, so that the optical splitter 700 is further disposed. The optical splitter 700 is disposed between the reflective display substrate 600 and the optical path combiner for separating the illumination beam 58 from the optical path synthesizer and the slave display. The modulated light beam 59 reflected by the substrate 600. Specifically, the illumination beam 58 is received in a first direction 103, and then the illumination beam 58 is directed in an incident direction 107 to the display substrate 600; the beam splitter 700 receives the modulated beam 59 emerging in the modulation direction 106 and directs its transmission to the projection lens 800.

The projection lens 800 is used to project an image onto the receiving screen, and is also used to adjust the quality of the image to obtain an image with the smallest aberration and the best imaging effect. Projection lens 800 can include a plurality of lenses defined by a base lens face 42 and a base lens axis 28 that is perpendicular to base lens face 42. The projection lens 800 receives the image modulated light beam 59 carried by the display substrate 600 and carries the image information, and then projects on the receiving screen in the projection direction. The projection direction can be perpendicular to the base lens face 42.

When the display substrate of the embodiment is DMD, the spectroscope can simply adopt a complete internal reflector. (core TIR), please refer to the spectroscope used in DMD Digital Light Processing (DLP). The technical solution using the spectroscope is also applicable to a reflective microdisplay imager such as a deformable micro-interference modulation device.

Embodiment 6

FIG. 7 is a schematic structural diagram of an image projection system according to Embodiment 6 of the present invention. The difference between the embodiment and the fifth embodiment is as follows: The optical path synthesizer selects the technical solution provided by the second embodiment, and the display substrate 600 is a reflective display substrate. . In this embodiment, a mirror 400 is further disposed between the optical path combiner and the beam splitter 700 to change the direction of the illumination beam 58 to reflect the illumination beam 58 to the beam splitter 700 to meet the position of other optical devices. Combination requirements.

The reflective display substrate 600 in this embodiment may be a device including a multilayer microelectromechanical optical modulation micro-reflective lens array, wherein each micro-electromechanical optical modulation micro-reflective lens is equivalent to one pixel unit, and the aperture ratio thereof is over 90%. The spacing between every two microelectromechanical optically modulated micro-reflective lenses is only 1 micron or less.

The spectroscope 700 provided in this embodiment is a complete internal reflection prism (TIR prism), specifically including a first prism and a second prism. The illumination beam 58 incident on the TIR prism is totally reflected on the slope of the first prism, and is reflected. Light is projected into the display substrate 600. The modulated light beam 59 emitted from the display substrate 600 is transmitted through the interface of the first prism and the second prism to the projection lens 800 without changing direction, and is then directed to the receiving screen 300 via the lens lens 800.

The image projection system also includes a first collimating unit 510 and a second collimating unit 520. The first collimating unit 510 is disposed between the first light source 110 and the first incident surface 201; the second collimating unit 520 is disposed between the second light source 120 and the second incident surface 202. The first collimating unit 510 is configured to convert the light emitted by the first light source 110 into parallel light in the first direction 103; the second collimating unit 520 is configured to convert the light emitted by the second light source 120 into the second direction 104. Parallel light. The first collimating unit 510 and the second collimating unit 520 function to increase the parallelism of the light beams, and may be disposed as needed. The first collimating unit 510 and the second collimating unit 520 may be separately provided, or may be set together. .

Example 7 FIG. 8 is a schematic structural diagram of an image projection system according to Embodiment 7 of the present invention. The difference between this embodiment and the above embodiment is that the display substrate 600 adopts a reflective display substrate, specifically a reflective micro display imager, which is arranged in a matrix form. A reflective liquid crystal modulation device is used as a reflective light modulation pixel. And the incident direction and the modulation direction of the reflective display substrate are parallel and opposite to each other.

When a reflective liquid crystal modulation device is employed as the reflective microdisplay imager, the beam splitter 700 is preferably a polarization beam splitter (PBS). The polarization beam splitter 700 reflects the light beam of one of the polarization directions of the illumination beam 58 to the reflection type liquid crystal modulation device, and causes the modulated light beam 59 having the opposite polarization direction modulated by the reflection type liquid crystal modulation device to be reflected toward the projection lens 800. The reflective liquid crystal modulating device is disposed opposite to the optical path synthesizer, and the polarizing beam splitter 700 is disposed between the reflective liquid crystal modulating device and the optical path synthesizer.

Example eight

FIG. 9 is a schematic structural diagram of an image projection system according to Embodiment 8 of the present invention. The difference between this embodiment and the above embodiment is that the display substrate 600 is a transmissive display substrate, and no optical splitter is needed.

This embodiment is described by taking the optical path synthesizer provided in the first embodiment as an example. The display substrate 600 may specifically include a transmissive liquid crystal modulation device arranged in a matrix form, and the modulation direction 106 of the transmissive display substrate 600 overlaps with the incident direction 108 thereof. .

The transmissive display substrate 600 may be a transmissive liquid crystal modulation device. The transmissive display substrate 600 directly receives the illumination beam 58 from the optical path combiner in the first direction 103, and modulates to generate a modulated beam 59. The first direction 103 of the illumination beam 58 is transmitted. The modulation direction 106 is the same as the modulation beam 106 transmitted.

Example nine

FIG. 10 is a schematic structural diagram of an image projection system according to Embodiment 9 of the present invention. This embodiment is similar to Embodiment 8 above, and the display substrate 600 also adopts a transmissive display substrate, and there is no need to provide a spectroscope. This embodiment is specifically described by taking the optical path synthesizer provided in the second embodiment as an example.

Reference can be made to the description of the functions of the optical elements in the foregoing sixth embodiment. In the present embodiment, the transmissive display substrate 600 is used. The emission directions of the first light beam 101 and the second light beam 102 from the optical path synthesizer are the same as the incident direction of the display substrate 600. After the display substrate 600 forms the modulated light beam 59, the transmission direction is not changed. Transmission continues to the projection lens 800 in the modulation direction and is ultimately imaged on the receiving screen 300. Example ten

FIG. 11 is a schematic structural diagram of an image projection system according to Embodiment 10 of the present invention. The embodiment may be based on the foregoing embodiments, and the difference is that the number of optical path synthesizers is multiple, and the first direction is aligned in the first direction, and The first incident surface 201 and the exit surface 203 of the adjacent optical path combiner are disposed opposite each other. For the reference to the technical solution of the foregoing fourth embodiment, the number of the second light sources 120 is plural, and the first light source 120 is sequentially arranged in the first direction 103. The second incident surface 202 of the optical path combiner is correspondingly disposed.

The image projection system of the present embodiment includes a first light source 110 and a plurality of second light sources 120, and the second light source 120 and the optical path combiner are arranged side by side in the first direction 103. Preferably, the first incident surface 201 is opposite and adjacent to the adjacent exit surface 203. The plurality of optical path synthesizers are respectively matched with the plurality of second light sources 120, and the light emitted by the second light source 120 is separately synthesized by the matched optical path synthesizer and synthesized to be transmitted in the first direction 103.

It should be noted that, in the embodiment shown in FIG. 4, although two sets of optical path synthesizers are taken as an example, the present invention is not limited thereto, and may be an image projection system including a plurality of sets of optical path synthesizers, which is the embodiment. For a transmissive image projection system including a plurality of optical path synthesizers, in order to avoid loss of optical energy, the connected light exit surface and the light incident surface are aligned, and the light emitted by each of the second light sources is respectively matched by the optical path synthesizer matched thereto. Perform the synthesis. Those skilled in the art can select a reasonable number of optical path synthesizers in accordance with the above embodiments in accordance with their own needs.

Embodiment 11

FIG. 12 is a schematic structural diagram of an image projection system according to Embodiment 11 of the present invention. The difference between this embodiment and Embodiment 12 is that a reflective display substrate is used to form a reflective image lens system. The function and position of various optical components can be found in the technical solutions of the foregoing embodiments. It should be noted that the above embodiments are only for explaining the technical solutions of the present invention, and are not intended to be limiting; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those skilled in the art that: The technical solutions described in the foregoing embodiments are modified, or some of the technical features are equivalently replaced. The modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

Claim

An optical path synthesizer, comprising:

2. The optical path synthesizer according to claim 1, wherein:

The total reflector has a refractive index that is less than the refractive index of the optical device.

The optical path synthesizer according to claim 2, wherein the reflecting surface is disposed in parallel with the transmitting surface.

4. The optical path synthesizer according to claim 3, wherein: said optical device comprises first optical device and second optical device, said total reflector being clamped between said first optical device and said second optical device Between devices.

5. The optical path synthesizer according to claim 4, wherein:

The materials used by the first optical device and the second optical device have the same refractive index;

The angle between the first direction and the normal of the reflective surface is greater than or equal to a critical angle of total reflection of the second optical device, and the surface of the first optical device and the second optical device are disposed to be increased. Through the membrane.

6. The optical path synthesizer according to claim 4, wherein:

An angle between the first direction and a normal of the reflective surface is smaller than a total reflection critical angle of the first optical device;

An angle between the first direction and a normal to the reflective surface is greater than or equal to a critical angle of total reflection of the second optical device.

The optical path synthesizer according to any one of claims 2 to 6, wherein an air gap is formed between the reflecting surface and the transmitting surface of the total reflector.

8. The optical path synthesizer according to claim 6, wherein: the materials used in the first optical device and the second optical device have different refractive indices.

The optical path synthesizer according to claim 5 or 6 or 8, wherein the first direction and the second direction are perpendicular to each other.

The optical path synthesizer according to claim 9, wherein: the first optical device and the second optical device have a cross-sectional shape of a right-angled trapezoid, and the two right-angled trapezoids are combined into a rectangular shape.

The optical path synthesizer according to claim 5 or 8, wherein: the first optical device has a transmission side forming the transmission surface; the second optical device is a polygon, and the polygon includes at least a a second incident edge, a total reflection edge, a first reflection edge, a second reflection edge, and an exit edge; the total reflection edge serves as a reflection surface, and the total reflector is sandwiched between the transmission edge; a side as the second incident surface for receiving a second light beam incident in a third direction; the first reflective side and the second reflective side being used for a second light beam incident from the second incident side The two directions are reflected to the total reflection edge; the exit edge serves as the exit surface for emitting a first light beam transmitted and transmitted in the first direction and a second light beam reflected and transmitted in the first direction.

The optical path synthesizer according to claim 11, wherein the first direction and the third direction are perpendicular to each other.

The optical path synthesizer according to claim 12, wherein: the first incident side is perpendicular to the first direction, and the second incident side is parallel to the first direction, the exit side It is perpendicular to the first direction.

The optical path synthesizer according to claim 13, wherein: the first optical device is a right-angle prism whose cross-sectional shape is a right-angled triangle, the oblique side of the right-angled triangle is a transmission side, and the right-angled triangle and the first a first incident side perpendicular to the direction serves as the first incident surface; the second optical device is a polygonal prism.

The optical path synthesizer according to claim 14, wherein: the right angle prism and The cross-sectional shape of the polygonal prisms is a right-angled pentagon, and the right-angled triangles cooperate to be a right angle of the pentagon.

The optical path synthesizer according to claim 11, wherein the first reflecting side and the second reflecting side are coated with a total reflection film.

The optical path synthesizer according to any one of claims 1 to 10, wherein: the optical path synthesizer comprises a plurality of sets of optical devices and total reflectors arranged in a first direction, and adjacent optical devices. The first incident surface and the outgoing surface are disposed opposite each other.

18. An image projection system, comprising: a light source, a display substrate, a projection lens, and a receiving screen, further comprising: the optical path synthesizer according to any one of claims 1 to 16; wherein the light source comprises a first light source and a second a first light source for emitting a first light beam toward the first incident surface, the second light source for emitting a second light beam toward the second incident surface; the first light beam and the second light beam The exit surface exits in a first direction to form an illumination beam.

The image projection system according to claim 18, wherein: the number of the optical path synthesizers is plural, sequentially arranged in the first direction, and the first incident surface and the outgoing surface of the adjacent optical path synthesizer are positive For the setting; the number of the second light sources is plural, arranged in the first direction, and respectively corresponding to the second incident surfaces of the optical path synthesizers.

20. The image projection system of claim 18, wherein: the first source and the second source are light emitting diodes or lasers.

The image projection system according to claim 18, further comprising: a first collimating unit disposed between the first light source and the first incident surface; and/or a second collimating unit, Provided between the second light source and the second incident surface.

22. The image projection system of claim 18, wherein: the display substrate is a microdisplay imager comprising a plurality of optically modulated pixels tiling in an array in a microdisplay imaging plane, the optics The modulating pixel receives the illumination beam in the incident direction and provides an image modulated beam in the modulation direction.

The image projection system according to claim 22, wherein: said projection lens Defined by a base lens face that is perpendicular to the base lens face and a base lens axis that receives the image modulated beam and projects on the receiving screen in the projection direction.

The image projection system according to any one of claims 18 to 23, wherein: the display substrate is a reflective display substrate, and the image projection system further comprises a beam splitter disposed on the reflective display substrate Between the light path synthesizer and the light path.

The image projection system according to claim 24, wherein: the reflective display substrate is a reflective microdisplay imager, comprising reflective microelectromechanical optical modulation pixels, and the optical splitter is a complete internal reflection prism. .

The image projection system according to claim 25, wherein: the reflective microelectromechanical optical modulation pixel is a deformable micromirror device or a deformable micro interference modulation device, and the reflective display substrate is incident. The direction and modulation direction are parallel and opposite to each other.

The image projection system according to claim 24, wherein: the reflective display substrate is a reflective microdisplay imager, comprising a reflective liquid crystal modulation device arranged in a matrix form, wherein the optical splitter is a polarization beam splitter. And the incident direction and the modulation direction of the reflective display substrate are parallel and opposite to each other.

The image projection system according to any one of claims 18 to 23, wherein the display substrate is a transmissive display substrate.

The image projection system according to claim 28, wherein the transmissive display substrate comprises a transmissive liquid crystal modulation device arranged in a matrix form, and an incident direction and a modulation direction of the transmissive display substrate overlap each other.