WO2019104915A1

WO2019104915A1 - Projection system and tir prism group

Info

Publication number: WO2019104915A1
Application number: PCT/CN2018/080694
Authority: WO
Inventors: 高志强; 杨伟樑; 赵远; 林清云
Original assignee: 广景视睿科技（深圳）有限公司
Priority date: 2017-12-01
Filing date: 2018-03-27
Publication date: 2019-06-06
Also published as: CN207424511U

Abstract

A projection system and a TIR prism group, the projection system comprising: an illumination light source (21), a TIR prism group (22), a DMD chip (23) and a projection lens (24), the TIR prism group (22) is provided between the illumination light source (21) and the projection lens (24); a reflective film is provided in the TIR prism group (22), such that an illumination light beam emitted from the illumination light source (21) is parallel or coincident with an optical axis of a projection light beam which is emitted to the projection lens (24) after light path converting by means of the TIR prism group (22), enabling the illumination light source (21), the TIR prism group (22) and the projection lens (24) to be arranged in a straight line. The projection system of the present invention is capable of reducing the size of a DLP projector without affecting the projection performance.

Description

Projection system and TIR prism set

The present application claims priority to Chinese Patent Application No. PCT Application No. No. No. No. No. No. No. No. No. No. No. No. No. in.

Technical field

The present application relates to the field of digital projection display technology, and in particular to a projection system and a TIR prism set.

Background technique

With the development of semiconductor technology, the increasingly diversified portable electronic products have made the demand for micro projectors more and more. At present, the more common digital light processing (DLP) micro projectors.

The existing DLP pico projector usually uses an illumination prism (TIR prism or RTIR prism) to compensate the illumination source of the digital micro mirror device (DMD) to form a telecentric optical path to match the needs of the DMD chip. The incident light and the reflected light, and the conventional TIR prism projection system structure is as shown in FIG. 1. The illumination beam from the illumination source 11 is once totally reflected by the TIR prism group 12 and enters the DMD chip 13, and the projection beam of the DMD chip 13 is emitted. After being transmitted through the TIR prism group 12, it is incident on the projection lens 14. At this time, the illumination beam and the projection beam are perpendicular, that is, the illumination source 11 and the projection lens 14 are disposed perpendicularly, not on the same line. Due to the large volume of the TIR prism group itself, and the vertical arrangement of the conventional TIR prism projection system illumination source 11 and projection lens 14, the volume of the DLP pico projector is further increased, which is not convenient to carry. Further, It is also impossible to embed electronic devices such as mobile phones or tablets. Therefore, if DLP pico projectors are to be widely used, the size and weight of the projection system should be further reduced without affecting the projection performance to ensure high projection quality. It is also more portable.

Based on this, the inventors have proposed a projection system and a TIR prism group, which can reduce the size of the DLP projector without affecting the projection performance.

Summary of the invention

The technical problem to be solved by the embodiments of the present application is to provide a projection system and a TIR prism group, which can reduce the size of the DLP projector without affecting the projection performance.

In order to solve the above technical problem, a technical solution adopted by the embodiment of the present application is to provide a projection system, including:

Illumination source, TIR prism set, DMD chip and projection lens;

The TIR prism group is disposed between the illumination source and the projection lens for receiving an illumination beam emitted by the illumination source, and optically converting the illumination beam to cause the illumination beam to be incident on the DMD a chip, and receiving a projection beam output by the DMD chip according to the illumination beam, and performing optical path conversion on the projection beam to output to a projection lens;

The illumination beam emitted by the illumination source is parallel or coincident with the optical axis of the projection beam emitted by the TIR prism group, and the TIR prism group, the illumination source and the projection lens are arranged in a straight line.

Optionally, the TIR prism set comprises:

a first prism and a second prism;

The first prism includes a first surface, a second surface, and a third surface; the second prism includes a fourth surface, a fifth surface, and a sixth surface; wherein the second surface and the fourth surface have inner dimensions a reflective interface, the fifth surface is plated with a reflective film;

The DMD chip is disposed adjacent to a side of a third surface of the first prism, the illumination source is adjacent to a first surface of the first prism, and the projection lens is adjacent to a sixth surface of the second prism.

Optionally, the shapes of the first prism and the second prism are both triangular.

Optionally, an angle between the second surface and the third surface of the first prism is 20° to 45°, and the shape of the second prism cross section is an isosceles right triangle.

Optionally, the DMD chip is parallel to a third surface of the first prism, the sixth surface of the second prism is perpendicular to the third surface of the first prism; and the projection beam is totally reflected by the fourth surface of the second prism The central optical axis is perpendicular to the sixth surface of the second prism.

Optionally, the fifth surface of the second prism is a plane or a curved surface.

Optionally, a gap is formed between the second surface of the first prism and the fourth surface of the second prism.

Optionally, a third prism is disposed between the second surface of the first prism and the fourth surface of the second prism.

Optionally, the third prism includes: a seventh surface and an eighth surface, and the seventh surface and the eighth surface may be a plane or a curved surface;

A gap is formed between the seventh surface of the third prism and the second surface of the first prism; and a gap is formed between the eighth surface of the third prism and the fourth surface of the second prism.

In order to solve the above technical problem, another technical solution adopted by the embodiment of the present application is to provide a TIR prism set applied to a projection system, including:

a first prism and a second prism;

The first prism includes a first surface, a second surface, and a third surface; the second prism includes a fourth surface, a fifth surface, and a sixth surface; wherein the second surface and the fourth surface have inner dimensions At the reflective interface, the fifth surface is plated with a reflective film.

The beneficial effects of the embodiments of the present application are: different from the prior art, the embodiment of the present application provides a projection system and a TIR prism set, the projection system includes: an illumination source, a TIR prism set, a DMD chip, and a projection lens. The TIR prism group is disposed between the illumination source and the projection lens, and a reflection film is disposed in the TIR prism group, so that the illumination beam emitted by the illumination source and the TIR prism group are converted into an optical path and then emitted to the projection. The optical axes of the projection beams of the lens are parallel or coincident, so that the illumination source, the TIR prism group and the projection lens can be arranged in a straight line, so that the layout of the projection system is compact and reasonable, and the size of the DLP projector is reduced without affecting the projection performance. .

DRAWINGS

The one or more embodiments are illustrated by the accompanying drawings, which are not to be construed as limiting. The drawings in the drawings do not constitute a scale limitation.

1 is a schematic structural view of a conventional TIR prism projection system;

2 is a schematic structural diagram of a projection system according to an embodiment of the present application;

3 is a schematic structural view of a TIR prism set provided by an embodiment of the present application;

4 is a schematic structural diagram of a projection system according to another embodiment of the present application;

FIG. 5 is a schematic structural diagram of a TIR prism set according to another embodiment of the present application; FIG.

6 is a schematic structural diagram of a projection system according to another embodiment of the present application;

7 is a schematic structural view of a TIR prism set according to still another embodiment of the present application;

Figure 8 is another embodiment of the TIR prism set shown in Figure 7.

Referring to FIG. 2 to FIG. 8 , 2 is a projection system, 21 is an illumination source, 22 is a TIR prism group, 221 is a first prism, 222 is a second prism, 2221 is a prism, 2222 is a relay lens, and 223 is a third prism. 23 is a DMD chip, 24 is a projection lens, P1 is the first surface, P2 is the second surface, P3 is the third surface, P4 is the fourth surface, P5 is the fifth surface, P6 is the sixth surface, and P7 is the seventh surface. On the surface, P8 is the eighth surface.

Detailed ways

In order to facilitate the understanding of the present application, the present application will be described in more detail below with reference to the accompanying drawings and specific embodiments. It is to be noted that when an element is described as being "fixed" to another element, it can be directly on the other element, or one or more central elements can be present. When an element is referred to as "connected" to another element, it can be a <RTI ID=0.0> </ RTI> </ RTI> <RTIgt; The terms "vertical," "horizontal," "left," "right," and the like, as used in this specification, are for the purpose of illustration.

Unless otherwise defined, all technical and scientific terms used in the specification are the same meaning The terms used in the specification of the present application are for the purpose of describing the specific embodiments and are not intended to limit the application. The term "and/or" used in this specification includes any and all combinations of one or more of the associated listed items.

The projection system of the embodiment of the present application can be applied to a Digital Light Processing (DLP) projector, and the projection system realizes projection by using a Digital Micromirror Device (DMD) as an imaging device, wherein The illumination source of the DMD chip is compensated by the TIR prism group, and different TIR prism groups have different influences on the projection performance of the projection system. The projection system will be specifically described below by several embodiments.

Embodiment 1:

Please refer to FIG. 2 , which is a projection system provided by an embodiment of the present application. The projection system 2 includes an illumination source 21 , a TIR prism set 22 , a DMD chip 23 , and a projection lens 24 .

The TIR prism group 22 is disposed between the illumination source 21 and the projection lens 24, and is located in the normal direction of the receiving surface of the DMD chip 23, and the illumination source 21, the TIR prism group 22 and the projection lens 24 are arranged in a straight line so that the projection The layout of System 2 is compact and reasonable.

Specifically, the receiving surface of the DMD chip 23 faces the TIR prism group 22 such that the illumination beam (a2 shown in FIG. 2) emitted from the TIR prism group 22 can be received by the receiving surface of the DMD chip 23, while the DMD The projection beam output from the chip 23 (shown as a3 in Fig. 2) can also be incident on the TIR prism group 22.

In the embodiment of the present application, the TIR prism group 22 is located above the receiving surface of the DMD chip 23. Of course, in some alternative embodiments, the TIR prism group 22 may also be located at the receiving of the DMD chip 23. Below the face, left or right side, etc.

It can be understood that the optical path of the projection system 2 is specifically: an illumination beam emitted from the illumination source 21 (shown as a1 in FIG. 2), received by the TIR prism group 22, and optically converted, and the illumination path after the optical path is converted (eg, A2) shown in FIG. 2 is emitted from the TIR prism group 22 to the DMD chip 23, and the DMD chip 23 outputs a projection beam (a3 shown in FIG. 2) and is incident on the TIR prism group 22 for optical path conversion and optical path. The converted projection beam (a4 as shown in FIG. 2) is emitted from the TIR prism group 22 to the projection lens 24. Wherein, the illumination beam (the a1 shown in FIG. 2) emitted by the illumination source 21 is parallel or coincident with the optical axis of the projection beam (a4 shown in FIG. 2) emitted by the TIR prism group 22, so that the TIR prism group 22, The illumination source 21 and the projection lens 24 can be arranged in a straight line, thereby making the layout of the projection system 2 more compact and reasonable, and reducing the size of the DLP projector.

In particular, the illumination source 21 is used to generate a white illumination beam. The illumination source 21 may be a light source component composed of a red LED light source, a green LED light source, and a blue LED light source, or may be a white LED light source. The light source component consisting of the red LED light source, the green LED light source and the blue LED light source obtains a white illumination beam by mixing red, green and blue light; and the white LED light source can directly obtain a white illumination beam.

The DMD chip 23 is used to output a projection beam, and the projection lens 24 is used to project the projection beam into an external display screen to realize projection.

Please refer to FIG. 3 , which is a TIR prism set provided by an embodiment of the present application. The TIR prism set 22 is configured to receive an illumination beam emitted by the illumination source 21 and perform optical path conversion on the illumination beam to enable the illumination beam. Incidentally incident on the DMD chip 23, and receiving the projection beam output by the DMD chip 23 according to the illumination beam, and performing optical path conversion on the projection beam to be emitted to the projection lens 24, specifically including: a first prism 221 and a second prism 222.

The first prism 221 has a triangular cross-sectional shape, and includes a first surface P1, a second surface P2, and a third surface P3. The angle between the second surface P2 and the third surface P3 is 20° to 45°. The Snell's law is satisfied such that the second surface P2 has an internal total reflection interface, and by adjusting the angle between the second surface P2 and the third surface P3, the projection beam and the illumination source that can be emitted by the TIR prism group 22 can be made. The optical axis of the outgoing illumination beam of 21 is coincident to improve the projection performance.

The second prism 222 has a cross-sectional shape of an isosceles right triangle, and includes a fourth surface P4, a fifth surface P5, and a sixth surface P6, the fifth surface P5 being perpendicular to the sixth surface P6, the fourth The surface P4 has an angle of 45° with the fifth surface P5 and the sixth surface P6, satisfies Snell's law, has an internal total reflection interface, and is coated with a reflective film in the fifth surface P5. The DMD chip 23 is directed to reflect the projection beam output from the DMD chip 23 to the fourth surface P4 for total reflection such that the projection beam emitted from the second prism 222 is parallel or coincident with the optical axis of the illumination beam emitted from the illumination source 21. In the embodiment of the present application, the fifth surface P5 is a plane, and the projection beam can be compensated and reflected.

Further, the third surface P3 of the first prism 221 is perpendicular to the sixth surface P6 of the second prism 222, and is disposed opposite to the fifth surface P5, and the reflective film of the fifth surface P5 faces the first The third surface P3 is connected to the third surface P3.

Further, the first prism 221 and the second prism 222 are made of the same material, and are generally made of optical glass or quartz glass, such as uniform, non-cracking, isotropic, good in light transmittance, high in dispersion rate, and low in temperature coefficient. The refractive indices of the first prism 221 and the second prism 222 are both greater than the refractive index of the air.

The first prism 221 and the second prism 222 are optically coupled by a slight air gap, specifically, a slight air gap optical between the second surface P2 of the first prism 221 and the fourth surface P4 of the second prism 222. Coupling, at this time, the projection beam transmitted from the first prism 221 to the second prism 222 can be refracted in the air gap, so that the fourth surface P4 fully exerts a compensation effect, in particular, when the projection beam has an incident angle smaller than a specific angle When incident on the second prism 222, the projection beam can be corrected by the refraction of the air gap to reduce picture distortion and optical aberration. The micro air gap can also reduce the volume of the TIR prism group 22 to a certain extent, so that the projected beam that exits satisfies the spot size required for microdisplay.

In the projection system 2, the illumination source 21 is adjacent to the first surface P1, and the DMD chip 23 is disposed adjacent to the third surface P3 and parallel to the third surface P3, and the projection lens 24 Adjacent to the sixth surface P6 and disposed in parallel with the sixth surface P6 such that a central optical axis of a projection beam totally reflected by the fourth surface P4 of the second prism 222 is perpendicular to the sixth surface P6, thereby It is incident perpendicularly to the projection lens 24.

It can be understood that the specific process of the optical path conversion of the TIR prism group 22 is that the illumination beam is transmitted to the first prism 221 via the first surface P1, and the full emission occurs on the second surface P2 to be transmitted to the DMD chip via the third surface P3. 23, the projection beam emerging from the DMD chip 23 is incident on the second prism 222 via the third surface P3, the second surface P2, and the fourth surface P4, and is reflected on the fifth surface P5 and then totally reflected on the fourth surface P4. Transmitted to the projection lens 24 via the sixth surface P6. At this time, the projection beam transmitted through the sixth surface P6 is parallel or coincident with the optical axis of the illumination beam, so that the TIR prism group 22, the illumination source 21, and the projection lens 24 can be presented. The linear arrangement further makes the layout of the projection system 2 more compact and reasonable, reducing the size of the DLP projector.

Embodiment 2:

Please refer to FIG. 4 , which is a projection system provided by an embodiment of the present application. The projection system 2 is substantially the same as the first embodiment. For the same content, refer to the first embodiment, and details are not described herein. The difference is that, in the embodiment of the present application, the TIR prism group 21 further includes: a third prism 223.

Specifically, referring to FIG. 5, the third prism 223 has a triangular cross-sectional shape, and the third prism 223 includes a seventh surface P7 and an eighth surface P8, and the seventh surface P7 and the eighth surface P8 are planar.

Of course, in some alternative embodiments, the seventh surface P7 and the eighth surface P8 may also be curved surfaces, which can compensate for the convergence of the light beam, reduce picture distortion and optical aberration, and improve projection performance.

The third prism 223 is disposed in a minute air gap of the second surface P2 of the first prism 221 and the fourth surface P4 of the second prism 222, specifically, the seventh surface P7 of the third prism 223 and the first The second surface P2 of the prism 221 is optically coupled by a slight air gap, and the eighth surface P8 of the third prism 223 and the fourth surface P4 of the second prism 222 are optically coupled by a slight air gap from the first The projected beam of the prism 221 is transmitted through the third prism 223 into the second prism 222, and refraction occurs in the third prism 223, so that the fourth surface P4 sufficiently exerts a compensating action.

Wherein, the refractive index of the third prism 223 is smaller than the refractive index of the first prism 221 and the second prism 222, and is close to the refractive index of the air. By changing the refractive index of the third prism 223, the projection beam is refracted to different degrees, thereby correcting the projection beam, so that the projection beam can be completely incident on the projection lens 24, reducing picture distortion and optical aberration, improving projection performance, and capable of The projection beam emitted from the second prism 222 is coincident with the optical axis of the illumination beam emitted from the illumination source 21, so that the layout of the projection system is compact and reasonable, and the size of the DLP projector is reduced.

Of course, in some alternative embodiments, the refractive index of the third prism 223 may also be the same as the refractive indices of the first prism 221 and the second prism 222.

Embodiment 3:

Please refer to FIG. 6 , which is a projection system provided by an embodiment of the present application. The projection system 2 is substantially the same as the second embodiment. For the same content, refer to the second embodiment, and details are not described herein. The difference is that, in the embodiment of the present application, the fifth surface P5 of the second prism 222 of the TIR prism group 21 is a curved surface.

Specifically, referring to FIG. 7 , the curved surface is a convex surface, and the inner surface of the curved surface is plated with a reflective film, which can compensate and concentrate the projection beam and then reflect. For example, when the projection beam incident on the second prism 222 reaches the fifth surface P5, a deviation occurs, so that the projection beam after the fifth surface P5 is totally reflected by the fourth surface P4 is not completely incident on the projection lens 24, at this time, After the fifth surface P5 is set as a curved surface, the fifth surface P5 concentrates the projection beam to the target position of the fourth surface P4, so that the projection surface of the fifth surface P5 reflected to the fourth surface P4 is totally incident on the projection lens. , reduce picture distortion and optical aberrations, improve projection performance.

Referring to FIG. 8, in some embodiments, the second prism 222 is composed of a prism 2221 and a relay lens 2222, and a fifth surface P5 plated with a reflective film is disposed on the relay lens 2222 for performing projection beam Convergence and reflection. Wherein, the prism 2221 is a right-angled triangle, and the right-angled sides thereof are all capable of transmitting, and the first right-angled edge (b1 shown in FIG. 8) transmits the projection beam to the relay lens for concentrated reflection, and the second right-angled edge (as shown in the figure) 8) b2) transmitting the projection beam totally reflected by the fourth surface P4 to the projection lens 24.

Embodiment 4:

Referring to FIG. 3, FIG. 5, FIG. 7, and FIG. 8, a TIR prism set 22 according to an embodiment of the present application is applied to a projection system 2, and the TIR prism set 22 includes: a first prism 221 and a second prism. 222.

The first prism 221 includes a first surface P1, a second surface P2, and a third surface P3; the second prism 222 includes a fourth surface P4, a fifth surface P5, and a sixth surface P6; wherein the second The surface P2 and the fourth surface P4 have an internal total reflection interface, and the fifth surface P5 is plated with a reflection film.

Since the projection system 2 of the above embodiment includes the TIR prism set 22 of the embodiment, the specific content and beneficial effects of the TIR prism set 22 of the present embodiment can be referred to the contents of the embodiment of the projection system 2 described above, and will not be further described herein.

It should be noted that the preferred embodiments of the present application are given in the specification of the present application and the accompanying drawings. However, the present application can be implemented in many different forms, and is not limited to the embodiments described in the specification. The examples are not intended to be limiting as to the scope of the present application, and the embodiments are provided to make the understanding of the disclosure of the present application more comprehensive. Further, each of the above technical features is further combined with each other to form various embodiments that are not enumerated above, and are considered to be within the scope of the specification of the present application; further, those skilled in the art can improve or change according to the above description. All such improvements and modifications are intended to fall within the scope of the appended claims.

Claims

A projection system, comprising: an illumination source (21), a TIR prism group (22), a DMD chip (23), and a projection lens (24);

The TIR prism group (22) is disposed between the illumination source (21) and the projection lens (24) for receiving an illumination beam emitted by the illumination source (21), and performing optical path conversion on the illumination beam So that the illumination beam is incident on the DMD chip (23), and receives a projection beam output by the DMD chip (23) according to the illumination beam, and optically converts the projection beam to a projection lens (twenty four);

The illumination beam emitted by the illumination source (21) is parallel or coincident with the optical axis of the projection beam emitted by the TIR prism group (22), the TIR prism group (22), the illumination source (21) and the projection lens (24) Arranged in a straight line.
The projection system of claim 1 wherein:

The TIR prism group (22) includes: a first prism (221) and a second prism (222);

The first prism (221) includes a first surface (P1), a second surface (P2), and a third surface (P3); the second prism (222) includes a fourth surface (P4) and a fifth surface ( P5) and a sixth surface (P6); wherein the second surface (P2) and the fourth surface (P4) have an internal total reflection interface, and the fifth surface (P5) is plated with a reflective film;

The DMD chip (23) is disposed adjacent to a third surface (P3) side of the first prism (221), and the illumination light source (21) is adjacent to the first surface (P1) of the first prism (221), The projection lens (24) is adjacent to a sixth surface (P6) of the second prism (222).
A projection system according to claim 2, wherein

The shapes of the cross sections of the first prism (221) and the second prism (222) are all triangular.
A projection system according to claim 3, wherein

An angle between the second surface (P2) and the third surface (P3) of the first prism (221) is 20° to 45°, and the shape of the second prism (222) is an isosceles right triangle .
A projection system according to claim 3, wherein

The DMD chip (23) is parallel to the third surface (P3) of the first prism (221), the sixth surface (P6) of the second prism (222) and the third surface of the first prism (221) ( P3) Vertical; the central optical axis of the projected beam totally reflected by the fourth surface (P4) of the second prism (222) is perpendicular to the sixth surface (P6) of the second prism.
A projection system according to claim 2, wherein

The fifth surface (P5) of the second prism (222) is a plane or a curved surface.
A projection system according to any one of claims 2 to 6, wherein

There is a gap between the second surface (P2) of the first prism (221) and the fourth surface (P4) of the second prism (222).
A projection system according to any one of claims 2 to 6, wherein

A third prism (223) is disposed between the second surface (P2) of the first prism (221) and the fourth surface (P4) of the second prism (222).
A projection system according to claim 8 wherein:

The third prism (223) includes: a seventh surface (P7) and an eighth surface (P8), and the seventh surface (P7) and the eighth surface (P8) may be a plane or a curved surface;

a gap between the seventh surface (P7) of the third prism (223) and the second surface (P2) of the first prism (221); an eighth surface (P8) and a second of the third prism (223) There is a gap between the fourth surfaces (P4) of the prisms (222).
A TIR prism set for use in a projection system (2), comprising:

a first prism (221) and a second prism (222);

The first prism (221) includes a first surface (P1), a second surface (P2), and a third surface (P3); the second prism (222) includes a fourth surface (P4) and a fifth surface ( P5) and a sixth surface (P6); wherein the second surface (P2) and the fourth surface (P4) have an internal total reflection interface, and the fifth surface (P5) is plated with a reflection film.