CN215932268U - Near-to-eye display optical machine and equipment thereof - Google Patents

Abstract

The utility model relates to a near-eye display optical machine and equipment thereof, which can simplify the structure of a DLP optical machine system, and is beneficial to reducing the volume of the optical machine and the cost of the optical machine. The near-eye display light machine comprises a backlight source, a DMD chip, an imaging lens, a relay assembly and a stray light intercepting prism. The relay assembly is correspondingly arranged among the backlight source, the DMD chip and the imaging lens and is used for transmitting the illuminating light emitted by the backlight source to the DMD chip and transmitting the image light modulated by the DMD chip to the imaging lens. The stray light intercepting prism is correspondingly arranged in a light path between the backlight source and the relay assembly and used for intercepting first-angle light rays in the illuminating light emitted by the backlight source and allowing second-angle light rays in the illuminating light emitted by the backlight source to transmit to the relay assembly, wherein the emergent angle of the first-angle light rays is larger than that of the second-angle light rays.

Description

Near-to-eye display optical machine and equipment thereof

Technical Field

The utility model relates to the technical field of near-eye display, in particular to a near-eye display optical machine and equipment thereof.

Background

In recent years, with the development of new display technologies, more and more devices such as small portable projection media players, projection mobile phones, wearable display devices (e.g., AR glasses, etc.) come into the market successively, so that the application modes thereof are more diversified, and the development prospects are expected.

In the field of near-eye display, optical waveguide display technology attracts attention in its closest approach to the form of glasses and can provide users with a good experience. Among various display schemes such as an LCoS display scheme, an LCD display scheme, a Micro-LED display scheme, and a DLP display scheme, which carry an optical waveguide, the DLP display scheme is popular and controversial because it has high light efficiency and high contrast.

However, a DMD (Digital Micro-Mirror Device; chinese: Digital Micro-Mirror Device) chip in the existing DLP optical machine is used as a semiconductor optical switch, and has three working states of an on state, a flat state and an off state, wherein the light of the on state is effective modulation light which needs to enter an imaging system, that is, target image light; the light in the flat and off states is the ineffective modulation light, and needs to be intercepted as much as possible to avoid interfering with the imaging and contrast ratio when entering the imaging system. Therefore, in order to ensure that light rays in the flat state and the off state cannot enter the imaging system, the conventional DLP optical mechanical system is complex in structure, and usually has to include modules such as collimation, color combination and dodging, so as to provide illumination light with a small divergence angle for the DMD chip, but this results in that the system does not have any advantages in terms of system volume and cost, but rather becomes an obstacle to the development thereof.

SUMMERY OF THE UTILITY MODEL

An advantage of the present invention is to provide a near-eye display optical engine and a device thereof, which can simplify the structure of a DLP optical engine system, and contribute to reducing the size and cost of the optical engine.

Another advantage of the present invention is to provide a near-eye display optical engine and an apparatus thereof, wherein in an embodiment of the present invention, the near-eye display optical engine can simplify the configuration of the DLP optical engine system and compress the volume of the optical engine system to the greatest extent by matching the backlight source with the stray light intercepting prism.

Another advantage of the present invention is to provide a near-eye display optical engine and a device thereof, wherein in an embodiment of the present invention, the near-eye display optical engine can effectively eliminate system stray light while compressing the size of the optical engine, thereby improving and enhancing the contrast of the optical engine.

Another advantage of the present invention is to provide a near-eye display optical engine and an apparatus thereof, wherein in an embodiment of the present invention, the near-eye display optical engine can reduce adverse effects on system contrast due to a large exit angle of the backlight source through the stray light intercepting prism, which is helpful for compressing the size of the optical engine and improving the optical engine contrast.

Another advantage of the present invention is to provide a near-eye display optical engine and a device thereof, wherein in an embodiment of the present invention, the near-eye display optical engine can balance the size of the optical engine system and balance the performance of the optical engine system in other aspects (such as cost or contrast).

Another advantage of the present invention is to provide a near-eye display light engine and apparatus thereof, wherein expensive materials or complex structures are not required in the present invention in order to achieve the above objects. Therefore, the present invention successfully and effectively provides a solution to not only provide a simple near-eye display optical-mechanical device and its equipment, but also increase the practicality and reliability of the near-eye display optical-mechanical device and its equipment.

To achieve at least the above and other advantages and in accordance with the purpose of the utility model, as embodied and broadly described herein, there is provided a near-eye display light engine including:

a backlight source;

a DMD chip;

an imaging lens;

the relay assembly is correspondingly arranged among the backlight source, the DMD chip and the imaging lens and is used for transmitting the illuminating light emitted by the backlight source to the DMD chip and transmitting the image light modulated by the DMD chip to the imaging lens; and

and the stray light intercepting prism is correspondingly arranged in a light path between the backlight source and the relay assembly and is used for intercepting first-angle light rays in the illuminating light emitted by the backlight source and allowing second-angle light rays in the illuminating light emitted by the backlight source to transmit to the relay assembly, wherein the emergent angle of the first-angle light rays is greater than that of the second-angle light rays.

According to an embodiment of this application, the veiling glare interception prism has incident surface, interception functional surface and exit surface, wherein the veiling glare interception prism the incident surface towards the backlight, and the veiling glare interception prism the exit surface towards relay unit spare, wherein the veiling glare interception prism the interception functional surface is inclined to relatively the light emitting area of backlight for make this first angle light in this illumination light follow the incident surface is penetrated in order to propagate to behind the interception functional surface the reflection takes place in interception functional surface department with deviating the exit surface.

According to an embodiment of the present application, the intercepting function face of the veiling glare intercepting prism is a total internal reflection face.

According to one embodiment of the present application, the stray light intercepting prism includes a first prism adjacent to the backlight and a second prism adjacent to the relay assembly, wherein the first prism and the second prism are disposed in a face-to-face spaced apart to form a total reflection gap between the first prism and the second prism.

According to an embodiment of the application, the first prism and the second prism are implemented as triangular prisms or wedge prisms.

According to one embodiment of the present application, the incident surface of the stray light intercepting prism is parallel to the light emitting surface of the backlight.

According to an embodiment of the present application, the entrance face of the stray light intercepting prism is parallel to the exit face of the stray light intercepting prism.

According to an embodiment of the present application, the relay assembly is an RTIR prism, wherein the RTIR prism includes a wedge prism close to the stray light intercepting prism and a total reflection prism close to the DMD chip and the imaging lens, and the wedge prism and the total reflection prism are disposed inclined to inclined and spaced apart by an inclined plane to form a gap between the wedge prism and the total reflection prism.

According to an embodiment of the present application, the inclined plane of the wedge prism in the RTIR prism is relatively inclined to the light emitting plane of the backlight, and the inclined direction of the inclined plane of the wedge prism is perpendicular to the inclined direction of the intercepting function plane of the stray light intercepting prism.

According to an embodiment of the present application, the near-eye display light engine further includes a light absorbing element, wherein the light absorbing element is correspondingly disposed on a side surface of the stray light intercepting prism for absorbing light rays propagating to the side surface of the stray light intercepting prism.

According to one embodiment of the application, the relay component is an RTIR prism or a TIR prism.

According to one embodiment of the application, the relay component is an intercepting RTIR prism or an intercepting TIR prism.

According to another aspect of the present application, there is further provided a near-eye display device comprising:

an optical waveguide; and

a near-eye display light engine, wherein the near-eye display light engine is correspondingly disposed on the coupling side of the optical waveguide, and the near-eye display light engine includes:

a backlight source;

a DMD chip;

an imaging lens;

the relay assembly is correspondingly arranged among the backlight source, the DMD chip and the imaging lens and is used for transmitting the illuminating light emitted by the backlight source to the DMD chip and transmitting the image light modulated by the DMD chip to the imaging lens so as to project the image light to the coupling port of the optical waveguide through the imaging lens; and

and the stray light intercepting prism is correspondingly arranged in a light path between the backlight source and the relay assembly and is used for intercepting first-angle light rays in the illuminating light emitted by the backlight source and allowing second-angle light rays in the illuminating light emitted by the backlight source to transmit to the relay assembly, wherein the emergent angle of the first-angle light rays is greater than that of the second-angle light rays.

Drawings

Fig. 1 is a schematic structural diagram of a near-eye display optical machine according to a first embodiment of the present invention;

fig. 2 is a schematic perspective view illustrating a stray light intercepting device in the near-eye display optical machine according to the first embodiment of the present invention;

fig. 3 is a schematic structural diagram of a backlight in the near-eye display light machine according to the first embodiment of the utility model;

fig. 4 is a schematic view showing an optical path of the stray light intercepting device according to the above-described first embodiment of the present invention when intercepting stray light;

fig. 5 is a schematic diagram illustrating an optical path of a wedge prism of an RTIR prism in the near-eye display optical machine for intercepting stray light according to the first embodiment of the present invention;

fig. 6 shows a variant of the near-eye display light engine according to the above-described first embodiment of the utility model.

Fig. 7 is a schematic structural diagram of a near-eye display optical machine according to a second embodiment of the utility model;

fig. 8 is a schematic optical path diagram of on-state light of a DMD chip in the near-eye display optical machine according to the second embodiment of the present application;

fig. 9 is a schematic optical path diagram illustrating flat state light of the DMD chip in the near-eye display optical machine according to the second embodiment of the present application;

FIG. 10 is a schematic diagram showing the optical path of the off-state light of the DMD chip in the near-eye display optical engine according to the second embodiment of the present application;

fig. 11 is a schematic structural diagram of a near-eye display optical machine according to a third embodiment of the utility model;

fig. 12 is a schematic optical path diagram of on-state light of a DMD chip in the near-eye display optical machine according to the third embodiment of the present application;

fig. 13 is a schematic optical path diagram illustrating flat state light of the DMD chip in the near-eye display optical engine according to the third embodiment of the present application;

FIG. 14 is a schematic diagram showing the optical path of the off-state light of the DMD chip in the near-eye display optical engine according to the third embodiment of the present application;

fig. 15 is a schematic structural diagram of a near-eye display device according to an embodiment of the utility model.

Description of the main element symbols: 1. a near-eye display light machine; 10. a backlight source; 100. a light emitting face; 11. a light emitting element; 12. a light guide plate main body; 20. a DMD chip; 30. an imaging lens; 40. a relay component; 41. an RTIR prism; 411. a wedge prism; 4111. a bevel; 4112. an end face; 412. a total reflection prism; 42. a TIR prism; 421. a prism; 422. a right-angle prism; 43. an intercept RTIR prism; 431. an illumination prism; 432. an image prism; 44. an intercepting type TIR prism; 441. an incident prism; 442. a display prism; 443. an exit prism; 50. a stray light intercepting prism; 500. a total reflection gap; 501. an incident surface; 502. intercepting a functional surface; 503. an exit surface; 504. a side surface; 51. a first prism; 52. a second prism; 60. a light absorbing element; 61. a black object; 2. an optical waveguide.

The present invention is described in further detail with reference to the drawings and the detailed description.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It will be understood that when an element is referred to as being "mounted on" another element, it can be directly on the other element or intervening elements may also be present. When a component is referred to as being "disposed on" another component, it can be directly on the other component or intervening components may also be present. When an element is referred to as being "secured to" another element, it can be directly secured to the other element or intervening elements may also be present.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the utility model herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the utility model. As used herein, the term "or/and" includes any and all combinations of one or more of the associated listed items.

Considering that the existing DLP optical-mechanical system is complex in structure, and generally includes modules such as collimation, color combination and light uniformization, and combines with market demands, how to make the volume of the DLP optical-mechanical system smaller and more compact and reduce system cost is a key element for focusing on directions of researchers at present and also for improving core competitiveness of such display schemes. Therefore, the application provides a new near-eye display optical machine and equipment thereof, and the technical scheme of illuminating through a backlight source and matching with a stray light intercepting prism not only can simplify the structure of an optical machine system to the maximum extent and compress the volume of the optical machine system, but also can well solve the problem of reducing the contrast of the optical machine system due to the larger angle of emergent light rays of the backlight source, so that the performances of all aspects of the system play a good balance role.

Referring to fig. 1 to 5, a first embodiment of the present invention provides a near-eye display light engine 1, which is adapted to project image light to a near-eye display device such as a light guide, so as to project the image light into human eyes through the near-eye display device, thereby obtaining a near-eye display experience. Specifically, as shown in fig. 1 to 5, the near-eye display light engine 1 may include a backlight 10 for emitting illumination light, a DMD chip 20 for modulating the illumination light into image light, an imaging lens 30 for projecting the image light, a relay assembly 40, and a stray light intercepting prism 50. The relay assembly 40 is correspondingly disposed between the backlight 10, the DMD chip 20 and the imaging lens 30, and is configured to transmit the illumination light emitted from the backlight 10 to the DMD chip 20, and transmit the image light modulated by the DMD chip 20 to the imaging lens 30.

In particular, the stray light intercepting prism 50 is correspondingly disposed in the optical path between the backlight 10 and the relay assembly 40, and is configured to intercept a first angle ray of the illumination light emitted from the backlight 10, and allow a second angle ray of the illumination light emitted from the backlight 10 to transmit to the relay assembly 40, wherein the exit angle of the first angle ray is greater than that of the second angle ray. Thus, when the backlight 10 emits illumination light, the light ray with a larger exit angle (i.e., the first-angle light ray) in the illumination light will be intercepted by the stray light intercepting prism 50 and will not enter the relay assembly 40; meanwhile, the light ray with a smaller exit angle (i.e. the second angle light ray) in the illumination light passes through the stray light intercepting prism 50 to enter the relay assembly 40, and then is transmitted to the DMD chip 20 through the relay assembly 40 to be modulated into corresponding image light, and then is transmitted to the imaging lens 30 through the relay assembly 40 to be projected.

In other words, the stray light intercepting prism 50 can intercept light rays in a first exit angle range in the illumination light emitted from the backlight 10, and allow light rays in a second exit angle range in the illumination light emitted from the backlight 10 to pass through to be transmitted to the relay assembly 40, wherein the angle value in the first exit angle range is larger than the angle value in the second exit angle range. It is understood that the exit angle of the light mentioned in the present application refers to the angle between the light and the light emitting path of the backlight 10, i.e. the angle between the light and the normal of the light emitting surface 100 of the backlight 10. For example, the angle values in the first exit angle range may each be greater than 12 °, and the angle values in the second exit angle range may each be less than 12 °.

It should be noted that, on one hand, the near-eye display optical engine 1 of the present application replaces the conventional illumination system with the backlight source 10 with a smaller size, and omits modules with larger size, heavier weight, and higher price, such as collimation, color combination, and light uniformization, which helps to simplify the structure of the optical engine system to the greatest extent and compress the volume of the optical engine system; on the other hand, the near-to-eye display optical engine 1 of the present application intercepts, by the stray light intercepting prism 50, light rays with a larger exit angle in the illumination light emitted by the backlight 10, and allows light rays with a smaller exit angle in the illumination light to pass through to be transmitted to the DMD chip 20 through the relay assembly 40, so that light rays in a flat state and an off state do not enter an imaging system, which is beneficial to well improving the problem that the contrast of the optical engine system is reduced due to an excessively large exit light angle in a conventional backlight.

It can be understood that the exit angle of the backlight 10 is very large, which results in a large divergence angle of the illumination light emitted therefrom, and if the backlight 10 is directly used to provide illumination light for the DMD chip 20, the light rays with a large exit angle in the illumination light may not enter the imaging system after being modulated into on-state light by the DMD chip 20, but instead, will cause flat-state light or off-state light to enter the imaging system, which will seriously affect the imaging quality and image contrast, so it appears to those skilled in the art that: the backlight 10 is not usable in DLP light engine systems. The near-eye display optical machine 1 of the present application breaks through the barrier of the conventional technology, that is, the modules of collimation, color combination, and light uniformization are used to obtain the illumination light required by the DMD chip 20, and instead, the backlight source 10 discarded in the prior art is used to provide the illumination light for the DMD chip 20, so that not only the structure of the optical machine system is simplified to the greatest extent and the volume of the optical machine system is compressed, but also the contrast of the optical machine system is improved well, so that the performances of the near-eye display optical machine 1 are well balanced.

More specifically, as shown in fig. 1, fig. 2 and fig. 4, the stray light intercepting prism 50 may have an incident surface 501 facing the backlight 10, an intercepting function surface 502 inclined with respect to the light emitting surface 100 of the backlight 10, and an exit surface 503 facing the relay assembly 40, wherein after the light rays with larger exit angles in the illumination light enter from the incident surface 501 to propagate to the intercepting function surface 502, the light rays with larger exit angles in the illumination light are reflected at the intercepting function surface 502 to deviate from the exit surface 503, so that the light rays with larger exit angles are prevented from exiting from the exit surface 503 to enter the relay assembly 40, thereby avoiding the interference with the contrast of the optical-mechanical system.

Preferably, the intercepting function surface 502 of the stray light intercepting prism 50 is implemented as a total internal reflection surface, that is, after the light ray with a larger exit angle in the illumination light enters from the incident surface 501 to propagate to the intercepting function surface 502, the total internal reflection condition is satisfied at the intercepting function surface 502, so as to generate total reflection to change the original propagation direction.

Illustratively, as shown in fig. 1, 2 and 4, the stray light intercepting prism 50 may include a first prism 51 adjacent to the backlight 10 and a second prism 52 adjacent to the relay assembly 40, wherein the first prism 51 and the second prism 52 are disposed in a face-to-face spaced apart manner to form a total reflection gap 500 between the first prism 51 and the second prism 52. Thus, the surface of the first prism 51 will provide the entrance surface 501 and the intercepting function surface 502 of the stray light intercepting prism 50; and the surface of the second prism 52 provides the exit surface 503 of the stray light intercepting prism 50. It is understood that the total reflection gap 500 may be implemented as, but not limited to, an air gap; of course, in other examples of the present application, the total reflection gap 500 may also be implemented as a non-air gap, for example, another transparent medium with a low refractive index, such as glue or glass, is disposed between the first prism 51 and the second prism 52, as long as it is ensured that the light ray with a large exit angle satisfies the total internal reflection condition at the intercepting function surface 502, and details of the present application are omitted.

Preferably, the first prism 51 and the second prism 52 are each implemented as a triangular prism, and the first prism 51 and the second prism 52 are disposed at intervals in a slope-to-slope manner to form the total reflection gap 500 between the slope of the first prism 51 and the slope of the second prism 52. At this time, the inclined surface of the first prism 51 is implemented as the intercepting function surface 502 of the stray light intercepting prism 50; and a surface of the first prism 51 facing the backlight 10 serves as the incident surface 501 of the stray light intercepting prism 50, and a surface of the second prism 52 facing the relay assembly 40 serves as the exit surface 503 of the stray light intercepting prism 50.

It should be noted that in other examples of the present application, the first prism 51 and the second prism 52 may also be implemented as other types of prisms such as wedge prisms, as long as the intercepting function surface 502 can be provided, and the description thereof is omitted here.

More preferably, the incident surface 501 of the stray light intercepting prism 50 is parallel to the exit surface 503 of the stray light intercepting prism 50, so that the propagation direction of the light ray with a smaller exit angle before and after passing through the stray light intercepting prism 50 is kept unchanged, which helps to simplify the light path design of the near-eye display light engine 1.

Most preferably, the incident surface 501 of the stray light intercepting prism 50 is parallel to the light emitting surface 100 of the backlight 10, so that the light with the zero outgoing angle is vertically emitted to the incident surface 501 of the stray light intercepting prism 50, and the loss of the light due to reflection at the incident surface 501 is avoided, which helps to reduce the loss of effective illumination light. It can be understood that, when the incident surface 501 of the stray light intercepting prism 50 is parallel to the light emitting surface 100 of the backlight 10, the smaller the incident angle of the light ray with the smaller exit angle in the illumination light at the incident surface 501 is, the weaker the reflection of the light ray with the smaller exit angle by the incident surface 501 is, so as to effectively reduce the loss of the light ray with the smaller exit angle, which is helpful to reduce the loss of the effective illumination light.

It is to be noted that an included angle between the intercepting functional surface 502 of the stray light intercepting prism 50 and the light emitting surface 100 of the backlight 10 may be designed according to a requirement of the DMD chip 20 on a divergence angle of effective illumination light, that is, the smaller the divergence angle of the effective illumination light required by the DMD chip 20 is, the larger the included angle between the intercepting functional surface 502 and the light emitting surface 100 needs to be designed, so that light rays with smaller exit angles in the illumination light can also satisfy a total reflection condition at the intercepting functional surface 502. It can be understood that, this application can be through adjusting the position and the angle of placing of backlight 10, and the angle of each light-passing face of veiling glare intercepting prism 50 to select the refracting index of each prism rationally, make the wide-angle veiling glare be reflected the prism lateral wall and avoid incidenting on DMD chip 20, also make simultaneously the incident angle of the light that reaches DMD chip 20 satisfy the illumination demand of chip.

In addition, since the light ray with a larger exit angle is emitted from the side surface of the stray light intercepting prism 50 (for example, the side surface of the first prism 51) after being reflected by the intercepting function surface 502, there is still a risk of entering the imaging system of the near-eye display light engine 1, and therefore, in order to solve this problem, as shown in fig. 2 and 4, the near-eye display light engine 1 according to the first embodiment of the present application may include a light absorbing element 60, wherein the light absorbing element 60 is correspondingly disposed on the side surface 504 of the stray light intercepting prism 50, and is used for absorbing the light ray transmitted to the side surface 504 of the stray light intercepting prism 50, so as to prevent the light ray with a larger exit angle from being emitted from the side surface of the stray light intercepting prism 50 after being reflected by the intercepting function surface 502 and entering the imaging system.

Preferably, the light absorbing element 60 is implemented as a black object 61 coated on the side 504 of the veiling glare intercepting prism 50. It is understood that the black object 61 may be, but is not limited to be, implemented as a black object such as an ink layer or black glue; of course, in other examples of the present application, the light absorbing element 60 may also perform surface treatment on the side surface 504 of the stray light intercepting prism 50 in some other extinction manners, as long as absorption of stray light can be achieved, which is not described herein again.

According to the first embodiment of the present application, as shown in fig. 1 and 3, the backlight 10 of the near-eye display light engine 1 may be, but is not limited to be, implemented as an edge-type backlight, that is, the backlight 10 includes a light emitting element 11 and a light guide plate body 12, wherein the light emitting element 11 is disposed on a side surface of the light guide plate body 12, so that light emitted by the light emitting element 11 is coupled in from a side of the light guide plate body 12. It is understood that the light emitting elements 11 of the backlight 10 may be, but are not limited to being, implemented as LEDs; accordingly, the light guide plate body 12 may be composed of, but not limited to, a light guide plate, various optical mold sheets such as a diffusion film, a cross prism film, and a reflective sheet, and a structural member.

It should be noted that the backlight 10 may also be implemented in other types of backlight illumination, such as direct-type backlight, as long as the required illumination light can be provided, and the description thereof is omitted here. It is understood that the backlight 10 may be implemented as, but is not limited to, a white light backlight, a color backlight (e.g., a backlight configured with RGB tri-color LEDs), or the like.

In addition, in the first embodiment according to the present application, as shown in fig. 1 and 5, the relay assembly 40 of the near-eye display optical engine 1 may be, but is not limited to, implemented as an RTIR prism 41, such that the light emitted from the exit surface 503 of the veiling glare intercepting prism 50 firstly passes through the RTIR prism 41 to be transmitted to the DMD chip 20, and then is modulated into image light by the DMD chip 20 and then is transmitted to the imaging lens 30 through the total reflection of the RTIR prism 41.

Exemplarily, as shown in fig. 1 and 5, the RTIR prism 41 may include a wedge prism 411 adjacent to the stray light intercepting prism 50 and a total reflection prism 412 adjacent to the DMD chip 20 and the imaging lens 30, wherein the wedge prism 411 and the total reflection prism 412 are disposed at a face-to-face interval to form an air gap between the wedge prism 411 and the total reflection prism 412, so that the image light modulated via the DMD chip 20 satisfies a total internal reflection condition at an inclined surface of the total reflection prism 412 to be totally reflected to propagate to the imaging lens 30. In other words, the light with a smaller exit angle passing through the stray light intercepting prism 50 firstly passes through the RTIR prism 41 to propagate to the DMD chip 20, and then is modulated into image light by the DMD chip 20, and then is totally reflected by the total reflection prism 412 of the RTIR prism 41 to propagate to the imaging lens 30.

Preferably, as shown in fig. 1 and fig. 5, an inclined surface 4111 of the wedge-shaped prism 411 in the RTIR prism 41 is relatively inclined to the light emitting surface 100 of the backlight 10, so that even though the light ray with a larger exit angle in the illumination light emitted by the backlight 10 can pass through the stray light intercepting prism 50, a total reflection condition can be satisfied when the light ray propagates to the inclined surface 4111 of the wedge-shaped prism 411, so as to be totally reflected by the wedge-shaped prism 411 to change the propagation direction, and further avoid the light ray with a larger exit angle in the illumination light from propagating to the DMD chip 20 to interfere with the optical imaging and contrast ratio.

It is noted that, as shown in fig. 1 and fig. 5, the light absorbing element 60 of the present application may be further disposed on the end surface 4112 of the wedge-shaped prism 411 to absorb the light transmitted to the end surface 4112 of the wedge-shaped prism 411, so as to prevent the light with a larger exit angle from exiting from the side surface of the wedge-shaped prism 411 to enter the imaging system after being reflected by the inclined surface 4111 of the wedge-shaped prism 411.

More preferably, as shown in fig. 1, the inclined surface 4111 of the wedge-shaped prism 411 has a different inclination direction from the inclination direction of the intercepting function surface 502 of the stray light intercepting prism 50, so that the high-angle light rays in different deviation directions satisfy the total internal reflection condition at the inclined surface 4111 of the wedge-shaped prism 411 and the intercepting function surface 502 of the stray light intercepting prism 50, respectively, to intercept the high-angle light rays in different deviation directions through the inclined surface 4111 of the wedge-shaped prism 411 and the intercepting function surface 502 of the stray light intercepting prism 50, respectively.

It can be understood that when the deviation direction of some light rays with larger emergent angles in the illumination light is the same as the inclined direction of the intercepting function surface 502 of the stray light intercepting prism 50, the light rays can more easily satisfy the total internal reflection condition at the intercepting function surface 502, and can be more easily intercepted by the intercepting function surface 502; even if the exit angle of the light rays deviating from the oblique direction of the intercepting function surface 502 is large, it is difficult to satisfy the total internal reflection condition at the intercepting function surface 502, and the light rays cannot be intercepted by the intercepting function surface 502. In other words, this application near-to-eye display ray apparatus 1 through inclination is different stray light interception prism 50 intercept functional surface 502 with wedge prism 411 inclined plane 4111 intercepts the big exit angle light (stray light) in different deviation directions respectively for effective light in this illumination light can obtain the compression in different directions, helps improving the imaging quality and the contrast of ray apparatus.

Most preferably, the inclined plane 4111 of the wedge-shaped prism 411 is perpendicular to the inclined direction of the blocking function surface 502 of the stray light blocking prism 50, that is, when the blocking function surface 502 of the stray light blocking prism 50 is inclined relative to the light emitting surface 100 of the backlight 10 in the front-back direction, the inclined plane 4111 of the wedge-shaped prism 411 is inclined relative to the light emitting surface 100 of the backlight 10 in the left-right direction, so as to maximally block the light with a large emergent angle.

It should be noted that, although in the first embodiment of the present application and fig. 1 thereof, the near-eye display optical engine 1 includes only one stray light intercepting prism 50, it is only an example and does not limit the scope of the present application. It is understood that in other examples of the present application, the near-eye display light engine 1 may also include two or more of the stray light intercepting prisms 50, and the inclination directions of the intercepting functional surfaces 502 of different stray light intercepting prisms 50 are different, so as to improve the stray light intercepting performance.

In addition, in other examples of the present application, one of the stray light intercepting prisms 50 may include two or more of the intercepting function surfaces 502, and the inclination directions of the intercepting function surfaces 502 are different, so that the stray light intercepting efficiency can be improved by intercepting the large exit angle light rays having different deviation directions only by one of the stray light intercepting prisms 50. For example, the exit surface 503 of the stray light intercepting prism 50 may be relatively inclined to the light emitting surface 100 of the backlight 10, and the inclination direction of the exit surface 503 of the stray light intercepting prism 50 is preferably opposite to the inclination direction of the intercepting function surface 502 of the stray light intercepting prism 50, so that the exit surface 503 of the stray light intercepting prism 50 may also be regarded as another intercepting function surface to simultaneously intercept two large-angle light rays with opposite deviation directions by one stray light intercepting prism 50.

It should be noted that, although the relay assembly 40 of the near-eye display optical engine 1 is implemented as the RTIR prism 41 in the above-described first embodiment of the present application, it is only an example. In other words, in other examples of the present application, the relay assembly 40 may also be implemented as other types of relay systems, such as a TIR prism, as long as the light relay requirements of the DLP light engine are met.

Exemplarily, fig. 6 shows a modified implementation of the near-eye display optical engine 1 according to the first embodiment of the present application, wherein the relay component 40 is implemented as a TIR prism 42, so that the light emitted from the exit surface 503 of the stray light intercepting prism 50 is transmitted to the DMD chip 20 via total reflection of the TIR prism 42, and then is modulated into image light by the DMD chip 20, and then is transmitted to the imaging lens 30 via the TIR prism 42.

Specifically, as shown in fig. 6, the TIR prism 42 may include a triangular prism 421 adjacent to the stray light intercepting prism 50 and the DMD chip 20 and a right-angle prism 422 adjacent to the imaging lens 30, wherein the triangular prism 421 and the right-angle prism 422 are disposed at a face-to-face interval to form an air gap between the triangular prism 421 and the right-angle prism 422, so that the illumination light passing through the stray light intercepting prism 50 satisfies a total internal reflection condition at a surface of the triangular prism 421 distant from the stray light intercepting prism 50 and the DMD chip 20 to be totally reflected to propagate to the DMD chip 20. In other words, the light ray with a smaller exit angle passing through the stray light intercepting prism 50 is totally reflected by the TIR prism 42 to propagate to the DMD chip 20, and then modulated into image light by the DMD chip 20 to propagate through the TIR prism 42 to the imaging lens 30.

Preferably, in this modified embodiment of the present application, the near-eye display optical machine 1 may include two stray light intercepting prisms 50, wherein the two stray light intercepting prisms 50 are sequentially disposed in the optical path between the backlight 10 and the TIR prism 42, and the oblique directions of the intercepting function surfaces 502 of the two stray light intercepting prisms 50 are perpendicular to each other, which helps to multiply the stray light intercepting effect. For example, when the intercepting function surface 502 of one of the stray light intercepting prisms 50 is biased to the front of the backlight 10, and the intercepting function surface 502 of the other stray light intercepting prism 50 is biased to the right of the backlight 10, the two stray light intercepting prisms 50 intercept large exit angle light rays deviating to the front and the right in the illumination light, respectively.

It should be noted that, in the first embodiment and the modified embodiments of the present application, the near-eye display optical engine 1 only performs stray light interception on the illumination light before reaching the DMD chip 20, so as to improve the contrast of the optical engine system. If the system contrast is further improved, the image light modulated by the DMD chip 20 may also be intercepted and eliminated with respect to the ineffective parasitic light, so as shown in fig. 7, the second embodiment of the present application may further provide a near-eye display optical engine 1, which can improve the interception of the parasitic light in the illumination light before reaching the DMD chip 20, and can further improve the secondary interception of the parasitic light in the image light modulated by the DMD chip 20, so as to improve the contrast of the optical engine system to the maximum extent.

Specifically, as shown in fig. 7 to 10, the near-eye display light engine 1 according to the second embodiment of the present application is different from the above-described first embodiment of the present application in that: the relay assembly 40 is implemented as an intercepting RTIR prism 43, wherein the intercepting RTIR prism 43 may include one illumination prism 431 and two image prisms 432, and the illumination prism 431 and the two image prisms 432 are sequentially disposed at intervals to form two intervals in the intercepting RTIR prism 43, so that the intercepting RTIR prism 43 has two total reflection surfaces, and image light modulated by the DMD chip 20, that is, on-state light shown in fig. 8, can propagate to the imaging lens 30 through one total reflection of the intercepting RTIR prism 43, and ineffective stray light emitted from the DMD chip 20, that is, flat-state light shown in fig. 9 and total reflection off-state light shown in fig. 10, can be intercepted by two total reflections of the DMD prism 412 without propagating to the imaging lens 30. It is understood that the illumination prism 431 of the present application may be, but is not limited to being, implemented as a wedge prism, and the image prism 432 may be, but is not limited to being, implemented as a triangular prism.

In other words, in the second embodiment of the present application, the intercepting RTIR prism 43 is equivalent to splitting the total reflection prism 412 in the RTIR prism 41 into two image prisms 432 arranged at intervals to form a gap in the total reflection prism 412, so that the total reflection prism 412 has two total reflection surfaces, and the light in the on state only satisfies the total reflection condition at the first total reflection surface, and only one total reflection occurs to be transmitted to the imaging lens 30; the light rays in the flat state and the off state can satisfy the total reflection condition at both the total reflection surfaces, so that the light rays are totally reflected twice and are not transmitted into the imaging lens 30.

Preferably, as shown in fig. 9 and 10, the light absorbing element 60 of the present application may be further disposed at the side end of the image prism 432 to absorb the light rays in the flat state and the off state after being totally reflected twice, so as to prevent the stray light from entering the imaging system and interfering with the imaging and contrast.

It should be noted that fig. 11 to 14 are close-to-eye display light engine according to the third embodiment of the present application, and the close-to-eye display light engine 1 according to the third embodiment of the present application is different from the above-mentioned first embodiment of the present application in that: the relay assembly 40 is implemented as an intercepting TIR prism 44, and the intercepting TIR prism 44 may include an incident prism 441 adjacent to the stray light intercepting prism 50, a display prism 442 adjacent to the DMD chip 20, and an exit prism 443 adjacent to the imaging lens 30, wherein the incident prism 441, the display prism 442, and the exit prism 443 are disposed two by two at intervals to form three intervals within the intercepting TIR prism 44, so that the incident prism 441 and the display prism 442 of the intercepting TIR prism 44 can each provide one total reflection surface. Thus, when the illumination light passing through the stray light intercepting prism 50 is totally reflected by the incident prism 441 to propagate to the DMD chip, the image light modulated by the DMD chip 20, i.e., the on-state light shown in fig. 12, can pass through the intercepting TIR prism 44 to propagate to the imaging lens 30, and the ineffective stray light emitted from the DMD chip 20, i.e., the flat-state light shown in fig. 13 and the off-state light shown in fig. 14, is totally reflected by the display prism 442 to be intercepted and not to propagate to the imaging lens 30. It is understood that the entrance prism 441 and the exit prism 443 of the present application may be implemented as, but not limited to, a four-prism, and the display prism 442 may be implemented as, but not limited to, a right-angle prism.

In other words, in the third embodiment of the present application, the intercepting TIR prism 44 is equivalent to first cutting off the corners of the three prisms 421 and the right-angle prism 422 of the TIR prism 42 adjacent to the DMD chip 20, and then additionally disposing a new right-angle prism at the cut edge of the TIR prism 42 to form two gaps in the intercepting TIR prism 44, so that the intercepting TIR prism 44 has two total reflection surfaces, and thus the on-state light is transmitted to the imaging lens 30 through the display prism 442, the incident prism 441 and the exit prism 443 in sequence; the light beams in the flat state and the off state can satisfy the total reflection condition at the inclined surface of the display prism 442, so as to be totally reflected and not transmitted into the imaging lens 30.

Preferably, as shown in fig. 13 and 14, the light absorbing element 60 of the present application is further disposed at the side of the display prism 442 to absorb the light rays in the flat state and the off state after being totally reflected twice, so as to prevent the stray light from entering the imaging system and interfering with the imaging and contrast.

It should be noted that, in other embodiments of the present application, the intercepting function surface 502 of the veiling glare intercepting prism 50 can be implemented as a surface coated with an angle selection film system in addition to the above-mentioned total internal reflection surface, so as to intercept the first angle light and allow the second angle light to pass through the angle selection film system, which is not described herein again.

According to another aspect of the present application, as shown in fig. 15, an embodiment of the present application may further provide a near-eye display device, which may include the above-mentioned near-eye display light engine 1 and a light guide 2, wherein the near-eye display light engine 1 is correspondingly disposed on the coupling side of the light guide 2, so as to transmit the image light projected by the near-eye display light engine 1 to human eyes through the light guide 2, thereby realizing near-eye display.

In addition, the near-eye display apparatus may further include a turning prism, wherein the turning prism is correspondingly disposed between the imaging lens 30 of the near-eye display optical machine 1 and the coupling port of the optical waveguide 2, and is configured to totally reflect the image light projected via the near-eye display optical machine 1 to be switchably transmitted to the coupling port of the optical waveguide 2. It is understood that, in other examples of the present application, the optical waveguide 2 in the near-eye display device may also be implemented as other types of near-eye display devices, such as a birdbath, as long as the image light projected by the near-eye display light engine 1 can be transmitted to the human eyes to realize near-eye display, and the details of the present application are omitted here.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the utility model. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims (13)

1. A near-eye display light engine, comprising:

a backlight source;

a DMD chip;

an imaging lens;

the relay assembly is correspondingly arranged among the backlight source, the DMD chip and the imaging lens and is used for transmitting the illuminating light emitted by the backlight source to the DMD chip and transmitting the image light modulated by the DMD chip to the imaging lens; and

and the stray light intercepting prism is correspondingly arranged in a light path between the backlight source and the relay assembly and is used for intercepting first-angle light rays in the illuminating light emitted by the backlight source and allowing second-angle light rays in the illuminating light emitted by the backlight source to transmit to the relay assembly, wherein the emergent angle of the first-angle light rays is greater than that of the second-angle light rays.

2. The near-eye display light engine of claim 1, wherein the veiling glare intercepting prism has an entrance surface, an intercepting function surface, and an exit surface, wherein the entrance surface of the veiling glare intercepting prism faces the backlight source, and the exit surface of the veiling glare intercepting prism faces the relay assembly, wherein the intercepting function surface of the veiling glare intercepting prism is relatively inclined to the light emitting surface of the backlight source for causing the first angle ray of the illumination light to be reflected at the intercepting function surface to deviate from the exit surface after being incident from the entrance surface to propagate to the intercepting function surface.

3. The near-eye display light engine of claim 2 wherein the intercepting functional surface of the veiling glare intercepting prism is a total internal reflection surface.

4. The near-eye display light engine of claim 3 wherein the veiling glare intercept prism comprises a first prism proximate the backlight and a second prism proximate the relay assembly, wherein the first prism and the second prism are disposed in a face-to-face spaced apart relationship to form a total reflection gap between the first prism and the second prism.

5. The near-eye display light engine of claim 4 wherein the first prism and the second prism are implemented as triangular prisms or wedge prisms.

6. The near-eye display light engine of claim 4 wherein the entrance face of the veiling glare intercepting prism is parallel to the light emitting face of the backlight.

7. The near-eye display light engine of claim 6, wherein the entrance face of the veiling glare intercepting prism is parallel to the exit face of the veiling glare intercepting prism.

8. The near-eye display light machine of any one of claims 2 to 7, wherein the relay component is an RTIR prism, wherein the RTIR prism includes a wedge prism close to the stray light intercepting prism and a total reflection prism close to the DMD chip and the imaging lens, and the wedge prism and the total reflection prism are disposed slope-to-slope and spaced apart to form a gap between the wedge prism and the total reflection prism.

9. The near-eye display light engine of claim 8 wherein the slanted surface of the wedge prism in the RTIR prism is relatively slanted to the light emitting surface of the backlight source, and the slanted direction of the slanted surface of the wedge prism is perpendicular to the slanted direction of the intercepting function surface of the veiling glare intercepting prism.

10. The near-eye display light engine of any one of claims 1 to 7, further comprising light absorbing elements disposed on the sides of the stray light intercepting prisms correspondingly for absorbing light propagating to the sides of the stray light intercepting prisms.

11. The near-eye display light engine of any one of claims 1-7 wherein the relay component is an RTIR prism or a TIR prism.

12. The near-eye display light engine of any one of claims 1-7 wherein the relay component is an intercepting RTIR prism or an intercepting TIR prism.

13. A near-eye display device, comprising:

an optical waveguide; and

the near-eye display light engine of any one of claims 1 to 12, and the near-eye display light engine is correspondingly disposed at a coupling-in side of the optical waveguide for projecting image light to a coupling-in port of the optical waveguide.

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