CN216434423U

CN216434423U - Optical element and projection system

Info

Publication number: CN216434423U
Application number: CN202123188717.8U
Authority: CN
Inventors: 朱小龙
Original assignee: Chengdu Jimi Technology Co Ltd
Current assignee: Chengdu Jimi Technology Co Ltd
Priority date: 2021-12-17
Filing date: 2021-12-17
Publication date: 2022-05-03
Anticipated expiration: 2031-12-17

Abstract

The utility model discloses an optical element, including first prism and second prism, first prism closes on the setting of modulation component, the first surface of first prism with the fourth surface of second prism is adjacent and two between the surface packing have the clearance dielectric layer, the refracting index of clearance dielectric layer increases to the direction of other end edge along the one end edge of first surface on the section at light path transmission place, the maximum refractive index of clearance dielectric layer is less than the refracting index of first prism. Optical element and projection system utilize the refracting index to have the clearance dielectric layer that changes to make the better according to predetermineeing the requirement of light beam transmit and the total reflection, reduce light loss, improve the light yield, improve the efficiency that the light beam passes through optical element.

Description

Optical element and projection system

Technical Field

The utility model relates to a projection lighting technology field especially relates to an optical element and projection system.

Background

A TIR prism is generally used in a projection system, an illumination beam of a light source system is guided to a DMD (Digital micromirror Device) through the TIR prism, then the Digital micromirror Device reflects the illumination beam to obtain an imaging beam, the imaging beam is guided to an imaging lens through the TIR prism, the TIR prism and the Digital micromirror Device cooperate to separate the illumination beam and the imaging beam reflected by the Digital micromirror Device, the illumination beam enters an interface (total reflection or transmission occurs at the interface) in the TIR prism in a state close to a critical angle of total reflection, the imaging beam formed by the Digital micromirror Device after reflecting the illumination beam has an angle change relative to the original illumination beam, so as to change an angle of the illumination beam relative to the interface in the TIR prism, in other words, the illumination beam is totally reflected at the interface and then the imaging beam is transmitted at the interface, or the illumination light beam is transmitted at the interface, and then the imaging light beam is totally reflected at the interface, so that the separation of the illumination light beam and the imaging light beam reflected by the digital micro-mirror element is realized.

As shown in fig. 1, in the TIR prism, an illumination beam entering into a TIR prism 2 from a light source system 1 is a focused beam, the illumination beam enters into a first prism from an AC surface and reaches a BC surface, the illumination beam has a varying incident angle with respect to the BC surface, the illumination beam passes through the BC surface and enters into an air gap between the first prism and a second prism, and then enters into the second prism from a DF surface, the illumination beam penetrates through a DE surface and emits to a digital micro-mirror element 3, an imaging beam is obtained by reflection of the digital micro-mirror element, the imaging beam passes through the DE surface and enters into the second prism and reaches the DF surface, the imaging beam is a divergent beam, the imaging beam has a varying incident angle with respect to the DF surface, the imaging beam is totally reflected at the DF surface and then exits from an EF surface, and finally enters into an imaging lens 4. The illumination light beam needs to penetrate through the BC surface as much as possible without total reflection, and the imaging light beam needs to be totally reflected as much as possible without transmission, so that the system efficiency and the light output power can be guaranteed.

SUMMERY OF THE UTILITY MODEL

The utility model discloses the technical problem that will solve and the technical task who provides improve prior art, provide an optical element, solve traditional TIR prism among the prior art and be difficult to make the light beam according to predetermineeing the requirement and transmit or the total reflection as far as, the great problem of luminous power loss.

For solving the above technical problem, the technical scheme of the utility model is that:

an optical element comprises a first prism and a second prism, wherein the first prism is arranged close to a modulation element, a first surface of the first prism is adjacent to a fourth surface of the second prism, a gap dielectric layer is filled between the first surface and the fourth surface of the second prism, the refractive index of the gap dielectric layer is increased along the direction from one end edge of the first surface to the other end edge on a section where an optical path is transmitted, and the maximum refractive index of the gap dielectric layer is smaller than that of the first prism. Optical element utilize and effectively improve the transmission and the total reflection situation of light beam at the clearance dielectric layer that sets up between first prism and second prism, because light source system gets into optical element's illuminating beam is conical focus light beam, light in the focus light beam has the angle of incidence that changes for the interface, utilize the clearance dielectric layer that has the refractive index change to make all light in the illuminating beam can both transmit or be the total reflection, the formation of image light beam that goes out by the modulation component reflection is conical divergent light beam, light in the divergent light beam also has the angle of incidence that changes for the interface, utilize the clearance dielectric layer that has the refractive index change to make all light in the formation of image light beam can both transmit or be the total reflection, thereby effectively reduce light loss, improve final light yield.

Furthermore, the refractive index of the gap dielectric layer is gradually increased or is increased in a step manner, and the gap dielectric layer with the gradually increased refractive index and the gap dielectric layer with the step increased refractive index can enable the light beam to be transmitted or totally reflected as far as possible according to requirements, so that the loss is reduced, and the light output power is improved.

Furthermore, the gap dielectric layer is formed by combining a plurality of sections with different refractive indexes, which are distributed along the increasing direction of the refractive index, so that the gap dielectric layer with the refractive index changing according to requirements is more convenient and simpler.

Furthermore, the change amplitude of the refractive index of the gap medium layer from the side close to the modulation element to the side far away from the modulation element along the first surface is in direct proportion to the sine value of the incident angle of the illumination light beam when the illumination light beam enters the first surface, so that the emergent condition of the imaging light beam at the interface is ensured to be different from that of the illumination light beam, namely, the illumination light beam is transmitted, the imaging light beam is changed into total reflection, and the illumination light beam is totally reflected, so that the imaging light beam is changed into transmission.

Further, the first prism includes a second surface and a third surface, the second surface being adjacent to the modulating element;

the first surface is used for transmitting the illuminating light beams which sequentially pass through the second prism and the gap medium layer into the first prism, the second surface is used for transmitting the illuminating light beams to the modulation element, the second surface is used for transmitting the imaging light beams formed by reflection of the modulation element into the first prism, and the first surface is used for totally reflecting the imaging light beams so that the imaging light beams are transmitted out from the third surface;

or the third surface is used for transmitting the illumination light beam into the first prism, the first surface totally reflects the illumination light beam so that the illumination light beam is transmitted from the second surface and is emitted to the modulation element, the second surface is used for transmitting the imaging light beam formed by reflection of the modulation element into the first prism, and the first surface is used for transmitting the imaging light beam and then sequentially passes through the gap medium layer and the second prism and is emitted.

The illumination light beam of the light source system enters the light from the first prism, the imaging light beam exits the light from the second prism, the illumination light beam of the light source system enters the light from the second prism, the imaging light beam exits the light from the first prism, and the illumination light beam and the imaging light beam can be flexibly selected according to needs.

Furthermore, the cross-sectional shapes of the first prism and the second prism are respectively triangular, so that the structure is simple and the implementation is convenient.

A projection system comprises the optical element.

Compared with the prior art, the utility model discloses the advantage lies in:

optical element and projection system utilize the refracting index to have the clearance dielectric layer that changes to make the better according to predetermineeing the requirement of light beam transmit and the total reflection, reduce light loss, improve the light yield, improve the efficiency that the light beam passes through optical element.

Drawings

FIG. 1 is a schematic diagram of a projection system according to the prior art;

FIG. 2 is a schematic structural diagram of a first embodiment of an optical device;

FIG. 3 is a schematic structural diagram of a second embodiment of an optical device;

fig. 4 is a schematic structural diagram of a third embodiment of an optical element.

In the figure:

light source system 1, TIR prism 2, DMD3, imaging lens 4, second prism 5, fourth surface 51, first prism 6, first surface 61, second surface 62, third surface 63, gap medium layer 7, and modulation element 8.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

The embodiment of the utility model discloses an optical element enables the light beam and transmits as far as possible and the total reflection according to predetermineeing, improves the efficiency that the light beam passes through optical element, improves the light yield.

Example one

As shown in fig. 2, an optical element mainly includes a first prism 6 and a second prism 5, the first prism 6 is disposed adjacent to a modulation element 8, a first surface 61 of the first prism 6 is adjacent to a fourth surface 51 of the second prism 5, and a gap medium layer 7 is filled between the two surfaces, a refractive index of the gap medium layer 7 increases along an edge of one end of the first surface 61 toward an edge of the other end on a cross section where an optical path is transmitted, a maximum refractive index of the gap medium layer 7 is smaller than a refractive index of the first prism 6, an interface formed by the first surface 61 and the gap medium layer 7 is a most important interface, and mainly realizes separation of an illumination beam and an imaging beam through the interface, in other words, the illumination beam is totally reflected at the interface to transmit the imaging beam, or the illumination beam is transmitted at the interface to totally reflect the imaging beam, the modulation element 8 reflects the illumination beam to form an imaging beam, and the imaging beam has an angle change with respect to the illumination beam, so that an incident angle of the imaging beam with respect to the interface is different from an incident angle of the illumination beam with respect to the interface, thereby realizing that the illumination beam and the imaging beam have different exit states at the interface, one being transmitted and the other being totally reflected, or the other being totally reflected and the other being transmitted.

In this embodiment, the cross-sectional shapes of the first prism 6 and the second prism 5 are respectively triangular, in other words, the first prism 6 and the second prism 5 are both triangular prisms, and the structure is simple and easy to implement. Specifically, the first prism 6 has three surfaces, which are a first surface 61, a second surface 62 and a third surface 63, respectively, the first surface 61 is a DF surface, the second surface 62 is a DE surface, the third surface 63 is an EF surface, the modulation element 8 is disposed near the DE surface, the refractive index of the gap dielectric layer 7 increases from D to F, the second prism 5 also has three surfaces, which are a BC surface, an AC surface and an AB surface, the fourth surface 51 is a BC surface, and the BC surface is adjacent to the first surface 61, in this embodiment, the BC surface is parallel to the first surface 61, so that the gap dielectric layer 7 is a flat plate layer with two parallel surfaces;

the refractive index of the gap dielectric layer 7 gradually increases or increases in a stepped manner along the direction from one end edge of the first surface 61 to the other end edge on the section where the optical path transmission is located, the gap dielectric layer 7 can be formed by filling the gap dielectric layer 7 between the DF plane and the BC plane in a film coating and vapor deposition manner, the gap dielectric layer 7 can be manufactured separately first, then the gap dielectric layer 7 is glued in front of the first surface 61 and the BC plane, the refractive index change of the gap dielectric layer 7 can be realized in a manner of controlling the doping concentration, the gap dielectric layer 7 can also be formed by combining a plurality of segments with different refractive indexes, which are arranged along the direction from one end edge of the first surface 61 to the other end edge on the section where the optical path transmission is located, the structure is simple, the implementation difficulty is low, each segment is manufactured separately and then combined, the precision control of the refractive index of each segment is more convenient, More precisely, the increase of the refractive index along the first surface 61 from the side close to the modulating element 8 to the side far from the modulating element 8 can be conveniently realized, and the implementation cost is low.

The optical element described in this embodiment is specifically an RTIR prism, the illumination light beam enters from the second prism 5, and the imaging light beam finally exits from the first prism 6, specifically, the illumination light beam enters from the AC plane into the second prism 5, and then exits from the BC plane, the BC plane and the gap medium layer 7 form an interface, the illumination light beam integrally inclines to the interface, because the illumination light beam is a focused light beam, and therefore, the incident angle of the light beam in the illumination light beam relative to the interface changes, as shown in fig. 2, the incident angle of the light beam in the illumination light beam on the side close to the point C is larger, and the incident angle of the light beam on the side close to the point B is smaller, although the refractive index of the gap medium layer 7 needs to be smaller than that of the first prism 6, there is no condition that must be satisfied between the refractive index of the gap medium layer 7 and that of the second prism 5, normally, the maximum refractive index of the gap medium layer 7 is smaller than that of the second prism 5, therefore, the illuminating light beam is from the optically dense medium to the optically sparse medium, so that the light beam close to the point C in the illuminating light beam is easy to be totally reflected and lost, and the refractive index of the interstitial medium layer 7 is gradually increased from D to F, namely the refractive index of the interstitial medium layer 7 is gradually increased from B to C, so that the critical angle of total reflection on the side close to the point C on the interface of the BC surface and the interstitial medium layer 7 is larger, the light beam close to the point C in the illuminating light beam can be effectively transmitted, the light loss is reduced, and the risk of total reflection caused by the gradual increase of the incident angle of the light beam in the illuminating light beam is reduced;

then the illuminating beam propagates to the interface formed by the DF surface of the first prism 6 and the gap medium layer 7 through the gap medium layer 7, at this time, the illuminating beam is from the optically thinner medium to the optically denser medium, so that the illuminating beam is certainly transmitted into the first prism 6, then the illuminating beam is further transmitted from the DE surface to the modulating element 8, the modulating element 8 specifically adopts a DMD, the illuminating beam is reflected by the modulating element 8 to form an imaging beam, the imaging beam is further transmitted from the second surface 62 into the first prism 6, then the imaging beam travels to the interface formed by the DF surface and the gap medium layer 7, at this time, the imaging beam is from the optically denser medium to the optically thinner medium, under the action of the modulating element 8, the imaging beam is subjected to an angle change relative to the illuminating beam directed to the modulating element 8, so that the incident angle of the imaging beam relative to the interface formed by the DF surface and the gap medium layer 7 is increased, further, the imaging beam is totally reflected at the interface instead of transmitted, and the imaging beam is a conical diverging beam, so that the incident angle of the light in the imaging beam relative to the interface formed by the DF surface and the interstitial medium layer 7 is changed, specifically, as shown in fig. 2, the incident angle of the light near the D point in the imaging beam is smaller, the incident angle of the light near the F point in the imaging beam is larger, the imaging beam is from the optically dense medium to the optically sparse medium, so that the light near the D point in the imaging beam is more easily transmitted and lost, since the refractive index of the interstitial medium layer 7 is increased from D to F, that is, the critical angle of the total reflection of the light near the D point on the interface formed by the DF surface and the interstitial medium layer 7 is smaller, the total reflection of the light near the D point in the imaging beam can be realized even if the incident angle is reduced, the light loss is reduced, and the risk that the incidence angle of the light rays in the imaging light beam is gradually reduced to cause easy transmission is reduced.

The optical element of this embodiment mainly realizes the separation of the illumination beam and the imaging beam through the interface formed by the DF surface and the interstitial medium layer 7, where the angles of the illumination beam and the imaging beam with respect to the interface are close to the critical angle and are respectively located on both sides of the critical angle, in other words, the angle of the illumination beam with respect to the interface is greater than the critical angle, and the angle of the imaging beam with respect to the interface is smaller than the critical angle, or the angle of the illumination beam with respect to the interface is smaller than the critical angle, and the angle of the imaging beam with respect to the interface is greater than the critical angle, so as to ensure that one of the illumination beam and the imaging beam is transmitted through the interface, and the other is totally reflected at the interface. In the present embodiment, the amplitude of the change of the refractive index of the gap medium layer 7 from the side close to the modulation element 8 to the side far from the modulation element 8 along the first surface 61 is proportional to the sine value of the incident angle of the illumination light beam incident on the first surface 61, so as to ensure that the emergence condition of the imaging light beam at the interface is different from that of the illumination light beam, i.e. the illumination beam is transmitted, the imaging beam becomes totally reflected, the illumination beam is totally reflected, the imaging light beam becomes transmitted, the reflection angle of the modulation element is determined, the micro-mirror of the modulation element deflects +/-12 degrees or +/-10 degrees and the like, the imaging light beam reflected by the modulation element is deflected only at a small angle relative to the illumination light beam incident to the modulation element, and the larger the incident angle of the illumination light beam incident on the first surface is, the larger the critical angle is, the different the emergence condition of the imaging light beam at the interface from the illumination light beam is.

A projection system comprises the optical element, a light source system, a projection lens and a modulation element, wherein an illumination light beam generated by the light source system is emitted to the optical element, an imaging light beam is generated under the action of the modulation element, and the imaging light beam is emitted from the optical element to the projection lens.

Example two

As shown in fig. 3, the difference from the embodiment is that the optical element described in the embodiment is specifically a TIR prism, the illumination beam enters from the first prism 6, and the imaging beam finally exits from the second prism 5, specifically, the illumination beam enters from the EF surface into the first prism 6, and then is totally reflected at the DF surface, the illumination beam is entirely inclined to the DF surface, since the illumination beam is a focused beam, the incident angle of the light ray in the illumination beam with respect to the DF surface changes, the incident angle of the light ray near the F point is larger, the incident angle of the light ray near the D point is smaller, so that the light ray near the D point in the illumination beam is more easily transmitted, the refractive index near the D point of the gap medium layer 7 needs to be smaller, so that the critical angle is smaller, and it is also satisfied that the refractive index of the gap medium layer 7 increases from D to F, and then the illumination beam exits from the DE surface to the modulation element 8, the illumination light beam is reflected by the modulation element 8 to obtain an imaging light beam, the imaging light beam is incident into the first prism 6 from the DE surface, then the imaging light beam travels to an interface formed by the DF surface of the first prism 6 and the gap medium layer 7, the modulation element 8 causes the imaging light beam to be angularly deflected relative to the illumination light beam originally incident on the modulation element 8, so that the incident angle of the imaging light beam relative to the interface is reduced and smaller than the critical angle, so that the imaging light beam can be transmitted out from the interface, because the imaging light beam is a divergent light beam, the incident angle of the light beam close to the D point in the imaging light beam is smaller, and the incident angle of the light beam close to the F point in the imaging light beam is larger, so that the light beam close to the F point in the imaging light beam is more easily subjected to total reflection, and the refractive index of the gap medium layer 7 close to the F point is required to be larger so as to be closer to the refractive index of the first prism 6, therefore, the critical angle close to the point F is increased, the refractive index of the gap medium layer 7 is gradually increased from D to F, so that the imaging light beam can be sufficiently transmitted from the DF plane, the light loss is reduced, then the imaging light beam penetrates through the gap medium layer 7 and then enters the second prism 5 from the BC plane, and finally exits from the AC plane.

EXAMPLE III

As shown in fig. 4, the illumination light beam is still incident from the second prism 5, and the imaging light beam finally exits from the first prism 6, which is different from the embodiment in that the modulation element 8 is disposed near the EF surface, the illumination light beam is incident from the AC surface to the second prism 5, then exits from the BC surface to the gap medium layer 7 after total reflection of the AB surface, then enters into the first prism 6 from the DF surface, then exits from the EF surface to the modulation element 8, the illumination light beam is reflected by the modulation element 8 to obtain the imaging light beam, the imaging light beam enters into the first prism 6 from the EF surface, then the imaging light beam finally exits from the DE surface after total reflection at the interface formed by the DF surface and the gap medium layer 7, likewise, the refractive index of the gap medium layer 7 increases from the side near the modulation element 8 to the side far from the modulation element 8 along the first surface 61, and the maximum refractive index of the gap medium layer 7 is smaller than that of the first prism 6 in short, the refractive index of the gap dielectric layer 7 is gradually increased from F to D, and the difference between the gap dielectric layer 7 and the first prism 6 is gradually reduced from F to D.

The above are only preferred embodiments of the present invention, and it should be noted that the above preferred embodiments should not be considered as limitations of the present invention, and the scope of the present invention should be subject to the scope defined by the claims. It will be apparent to those skilled in the art that various modifications and adaptations can be made without departing from the spirit and scope of the invention, and such modifications and adaptations are intended to be included within the scope of the invention.

Claims

1. An optical element is characterized by comprising a first prism (6) and a second prism (5), wherein the first prism (6) is arranged close to a modulation element (8), a first surface (61) of the first prism (6) is adjacent to a fourth surface (51) of the second prism (5), a gap medium layer (7) is filled between the first surface and the fourth surface, the refractive index of the gap medium layer (7) is increased along the direction from one end edge of the first surface (61) to the other end edge on a section where an optical path is transmitted, and the maximum refractive index of the gap medium layer (7) is smaller than that of the first prism (6).

2. Optical element according to claim 1, characterized in that the refractive index of the gap dielectric layer (7) increases gradually or stepwise.

3. Optical element according to claim 1, characterized in that the interstitial medium layer (7) is composed of a combination of several segments of different refractive index arranged along the direction of increasing refractive index.

4. An optical element according to claim 1, characterized in that the amplitude of the change of the refractive index of the gap dielectric layer (7) is proportional to the sine of the angle of incidence of the illumination beam on the first surface (61).

5. An optical element according to any one of claims 1 to 4, characterized in that the first prism (6) comprises a second surface (62) and a third surface (63), the second surface (62) being adjacent to the modulating element (8);

the first surface (61) is used for transmitting the illuminating light beams which sequentially pass through the second prism (5) and the gap medium layer (7) into the first prism (6), the second surface (62) is used for transmitting the illuminating light beams to the modulation element (8), the second surface (62) is used for transmitting the imaging light beams formed by reflection of the modulation element (8) into the first prism (6), and the first surface (61) is used for totally reflecting the imaging light beams so that the imaging light beams are transmitted out from the third surface (63).

6. An optical element according to any one of claims 1 to 4, characterized in that the first prism (6) comprises a second surface (62) and a third surface (63), the second surface (62) being adjacent to the modulating element (8);

the third surface is used for transmitting the illuminating light beam into the first prism (6), the first surface (61) is used for totally reflecting the illuminating light beam so that the illuminating light beam is transmitted from the second surface (62) to the modulation element (8), the second surface (62) is used for transmitting the imaging light beam formed by reflection of the modulation element (8) into the first prism (6), and the first surface (61) is used for transmitting the imaging light beam to be emitted and then sequentially passes through the gap dielectric layer (7) and the second prism (5) to be emitted.

7. An optical element according to any one of claims 1 to 4, characterized in that the cross-sectional shapes of the first prism (6) and the second prism (5) are respectively triangular.

8. A projection system comprising the optical element of any one of claims 1 to 7.