Optical engine and projection device

Abstract

According to the optical engine and the projection device using the optical engine, the optical engine comprises the shell, the light combination prism and the light blocking piece, and the light blocking piece is installed on the shell and located on the light emitting path of stray light of the light combination prism. Wherein the light blocking piece is used for blocking the stray light from irradiating to the shell; the light blocking piece is provided with a first opening, and the first opening corresponds to the light outlet of the shell. The projection device comprises a lens, and the lens is arranged at the light outlet of the shell, so that light rays from the light combination prism only irradiate the light blocking piece and the lens, the light rays are prevented from directly irradiating the shell, and the shell is further prevented from being aged and deformed due to heating.

Description

TECHNICAL FIELD

[0001] The present application relates to an optical engine and a projection device, in particular, to an optical engine and a projection device with a light-weighted shell. BACKGROUND

[0002] Miniature projectors are portable and low cost, although the size and brightness of the projected image cannot be compared with general projectors, but they have great appeal to business users who need to project on the move. With the increasing miniaturization of Digital Light Processing (DLP) projectors and their closer proximity to the general consumer population, the miniature projector market is also increasingly favored. The volume of miniature projectors is getting smaller and smaller, and at the same time, in order to be small in size and light in weight, the material selection of the shell of the optical engine is gradually changed to light-weighted materials such as plastic.

[0003] However, in the optical path design of the miniature projector, due to the refraction effect of the light combining prism in the optical path, part of the strong light will not be transmitted to the lens for projection, but will stay in the cavity of the optical engine shell. At this time, the strong light will cause the shell made of plastic and other materials to deform and age, thereby affecting the normal operation of the projector, and even possibly damaging the projector.

[0004] Therefore, how to improve the light and heat resistance of the optical engine of the miniature projector has become a new research topic. SUMMARY

[0005] The present application aims to provide an optical engine and a projection device with a light-weighted shell to avoid the shell from being directly irradiated by strong light and deforming and aging.

[0006] To achieve the above purpose, the present application provides an optical engine, comprising:

[0007] a shell having an exit opening;

[0008] a light combining prism mounted on the shell, the light combining prism being used to project effective image light out of the exit opening; and

[0009] a light blocking member mounted on the shell and located on the light exit path of stray light of the light combining prism;

[0010] wherein the light blocking member is used to block the stray light from irradiating the shell; the light blocking member has a first opening corresponding to the exit opening.

[0011] Preferably, at least part of the light blocking member has a gap with the shell.

[0012] Preferably, the surface of the light blocking member has an anti-reflection layer.

[0013] Preferably, the light blocking member has a frame portion and an extension portion;

[0014] The frame portion is fixed to the housing, and the first opening is located on the frame portion to expose a light exit of the housing; the extension portion is further used for heat dissipation.

[0015] Further preferably, the extension portion is coplanar with the frame portion;

[0016] Or, the extension portion is bent relative to the frame portion.

[0017] Further preferably, the extension portion is planar;

[0018] Or, the extension portion is wavy;

[0019] Or, the extension portion is a fin.

[0020] Preferably, the frame portion is inclined to a propagation direction of the stray light from the light combining prism, so that the stray light is not reflected by the frame portion to the light combining prism.

[0021] Preferably, the light blocking member is fixed to the housing by a screw or a clasp, wherein the screw or the clasp is arranged away from an irradiation area of the stray light.

[0022] Preferably, the light blocking member is embedded in the housing.

[0023] Preferably, the housing has a positioning column, and the light blocking member has a corresponding positioning groove.

[0024] Preferably, the housing has a plurality of positioning protrusions, and different parts of the light combining prism respectively abut against the plurality of positioning protrusions.

[0025] To achieve the above object, the present application provides a projection device, comprising:

[0026] A housing;

[0027] The optical engine described above is installed in the housing; and

[0028] A lens is installed in the housing, and the lens is located on a light exit path of the optical engine.

[0029] Compared with the prior art, the optical engine and the projection device provided by the present application have the following advantages: the optical engine comprises a housing, a light combining prism, and a light blocking member, wherein the light blocking member is installed in the housing and located on a light exit path of stray light of the light combining prism; the light blocking member is used to block the stray light from irradiating to the housing; the light blocking member has a first opening corresponding to a light exit of the housing; by using the light blocking member to block the stray light from irradiating to the housing, the stray light can be prevented from directly irradiating to the housing, and the housing can be prevented from being aged and deformed due to heat. Attached Figure Description

[0030] Figure 1 This is a partial structural schematic diagram of the projection device in one embodiment of the present invention;

[0031] Figure 2 This is a partial exploded view of the projection device in one embodiment of the present invention;

[0032] Figure 3 This is a partial structural schematic diagram of the projection device in one embodiment of the present invention from another perspective.

[0033] Figure 4 for Figure 1 Schematic diagram of the cross-sectional structure at point AA;

[0034] Figure 5 This is a three-dimensional structural diagram of a light-blocking component according to an embodiment of the present invention. Detailed Implementation

[0035] To provide a further understanding of the purpose, structure, features, and functions of the present invention, detailed descriptions are provided below with reference to specific embodiments.

[0036] Certain terms are used in the specification and claims to refer to specific elements. It will be understood by those skilled in the art that manufacturers may use different names to refer to the same element. This specification and claims do not distinguish elements by differences in name, but rather by differences in function. The term "comprising" throughout the specification and claims is an open-ended term and should be interpreted as "comprising but not limited to".

[0037] Please see Figures 1 to 4 The projection device provided by the present invention includes a housing (not shown in the figure), an optical engine 100, and a lens 200. The optical engine 100 and the lens 200 are respectively installed in the housing, and the lens 200 is located in the light output path of the optical engine 100. In another embodiment, the lens 200 can also be directly installed on the housing 10 of the optical engine 100. In other words, the optical engine 100 can also include the lens 200, and the present invention is not limited thereto.

[0038] The optical engine 100 comprises a housing 10, a light source (not shown in the figure) and a light combiner 21, wherein the housing 10 is made of, for example, a plastic material or other light-weight material; the light source is, for example, a laser light source, etc. The light source and the light combiner 21 are installed in the housing 10, the housing 10 has a light outlet, the light emitted by the light source is first transmitted to the light combiner 21, the light combiner 21 cooperates with the spatial light modulator to form an effective image light, and the light combiner 21 is further used to project the effective image light out of the light outlet and further through the lens 200. In a preferred embodiment, as shown in Figure 2 and Figure 3 The housing 10 has a plurality of positioning protrusions 12, and different parts of the light combiner 21 abut against the plurality of positioning protrusions 12, so that the light combiner 21 is more stably installed in the housing 10.

[0039] In the embodiment, the optical engine 100 further comprises a light blocking member 30 installed in the housing 21 and located on the light outlet path of the stray light generated by the light combiner 21 and / or the front light path, or the stray light can also be the waste light generated by the spatial light modulator (for example, a DMD). In the embodiment, the light blocking member 30 is installed at the housing 10 on the light outlet side of the light combiner 21. The light blocking member 30 is used to block the stray light from irradiating to the housing 10, wherein the light blocking member 30 is made of, for example, a metal member 30 made of a heat-resistant material such as titanium alloy, carbon steel, stainless steel, aluminum, etc. The light blocking member 30 has a first opening 30a corresponding to the light outlet of the housing 10, and the effective image light passes through the first opening 30a of the light blocking member 30 and the light outlet of the housing 21 in sequence and is then projected out through the lens 200. Further, the optical engine 100 further comprises a spatial light modulator (not shown in the figure) arranged adjacent to the light combiner 21 and located on the transmission path of the light emitted by the light source, the spatial light modulator cooperates with the light combiner 21 to form the effective image light. The spatial light modulator is, for example, a light transmission type spatial light modulator (for example, an LCD) or a light reflection type spatial light modulator (for example, a DLP, a DMD or an LCOS), and those skilled in the art can design a corresponding light path structure according to different types of the spatial light modulator, which will not be described here.

[0040] In a preferred embodiment, as shown in Figure 4 and Figure 5As shown, the light-blocking member 30 has a frame portion 301, which is fixed to the housing 10. A first opening 30a is located in the frame portion 301 to expose the light outlet of the housing 10. This means that light from the light-combining prism 21 will only illuminate the lens 200 and the light-blocking member 30, and will not directly illuminate the housing 10. The light-blocking member 30 (frame portion 301) serves to block stray light from the light-combining prism 21 from illuminating the housing 10, preventing the energy of the light from concentrating on the lightweight housing 10, thereby preventing the housing 10 from deforming due to heat. Preferably, the frame portion 301 is tilted at a specific angle to the propagation direction of the stray light from the light-combining prism 21, so that the stray light is not reflected back to the light-combining prism 21 by the frame portion 301, preventing the reflected stray light from affecting the projected image, such as introducing ghosting or light spots. It should be noted that the specific angle is designed according to the specific structure of the optical path, and is a design that can be implemented by those skilled in the art based on actual conditions, and will not be elaborated here.

[0041] In a preferred embodiment, the light-blocking member 30 further includes an extension 302 connected to the frame portion 301. The extension 302 increases the surface area of ​​the light-blocking member 30, thereby increasing the light-blocking area of ​​the light-blocking member 30. For example, the extension 302 is a plane 302 coplanar with the frame portion 301; or, as... Figure 5 As shown, the extension 302 can also be bent relative to the frame 301 to further block light reflected from the light-combining prism 21 and the frame 301, preventing it from illuminating other parts of the housing 10. Simultaneously, the extension 302 increases the surface area of ​​the light-blocking member 30, improving the heat dissipation area and further enhancing the heat dissipation performance of the optical engine 100. In a preferred embodiment, the extension can also be designed as a wave shape (not shown) or a fin shape (not shown). Preferably, the light-blocking member 30 can have multiple extensions (not shown), which can extend in multiple directions relative to the frame 301. For example, the light-blocking member 30 can have two extensions that extend in two opposite directions relative to the frame 301, but this invention is not limited thereto.

[0042] In a preferred embodiment, the surface of the light-blocking member 30 has an anti-reflective layer to reduce the reflection of light from the light-combining prism 21 by the light-blocking member 30 (e.g., frame 31). For example, the anti-reflective layer is an organic polystyrene layer or a polymethyl methacrylate layer; alternatively, it can be an inorganic metal oxide layer (such as magnesium oxide, aluminum oxide, etc.), a silicon oxide layer, etc., obtained through anodizing; or the surface of the light-blocking member 30 can be blackened, etc., and the present invention is not limited thereto. The organic anti-reflective layer and the blackening treatment reduce light reflection by absorbing light; the inorganic anti-reflective layer does not absorb light, but reduces light reflection by shifting the phase of a portion of the light, causing the shifted portion of the light to interfere cancelably with another portion of the light. In other embodiments, the extension 302 is designed as a surface structure or shape that can absorb excess light. For example, the light-blocking member 30 can be surface-etched / textured to form an anti-reflective surface structure, causing the light to undergo multiple reflections within the anti-reflective surface structure, thereby attenuating the energy of the light.

[0043] In a preferred embodiment, such as Figures 1 to 3 As shown, the light-blocking member 30 can be fixed to the housing 10 by screws; or, the light-blocking member 30 can also be fixed to the housing 10 by hooks. Preferably, the screws or hooks are positioned away from the irradiation area of ​​the light from the light-combining prism 21 to prevent heat from the light from being conducted to the screws or hooks. In the above embodiments, the light-blocking member 30 can also have an opening near the locking hole or hook. The opening can be located around the locking hole or hook, or between the main irradiation area of ​​stray light and the locking hole or hook, to extend the heat conduction path and further reduce heat conduction to the housing 10 through the screws or hooks and other connecting components. In other embodiments, the screws or hooks can also be made of materials with low thermal conductivity, such as titanium alloys, carbon steel, stainless steel, or aluminum, to reduce heat conduction from the screws or hooks to the housing 10.

[0044] In another embodiment, the light-blocking member 30 can also be embedded in the housing 10, so that the light-blocking member 30 and the housing 10 are integrally formed, which can reduce the installation steps of the light-blocking member 30 and thus reduce the manufacturing cost of the product.

[0045] Preferably, a gap is provided between at least part of the light blocking member 30 and the housing 10, that is, the light blocking member 30 is not tightly connected to the housing 10, and the air between the light blocking member 30 and the housing 10 serves as a heat insulator, which improves the heat dissipation efficiency of the light blocking member 30 and reduces the heat conducted from the light blocking member 30 to the housing 10. For example, a gasket (not shown in the figure, for example, the screw or the hook can be provided through the gasket to fix the gasket) can be provided between the light blocking member 30 and the housing 10, so that the light blocking member 30 and the housing 10 are separated by the gasket, but the present application is not limited thereto. The gasket is made of heat insulating materials such as glass fiber, asbestos, etc., or the gasket can also be a vacuum plate having a structure of reducing heat conduction efficiency, and the present application is not limited thereto. Preferably, the light blocking member 30 can also be thermally coupled with the external heat dissipation component of the spatial light modulator (such as DLP, DMD, LCOS or LCD) or the light source, so as to accelerate the heat dissipation efficiency of the light blocking member 30.

[0046] In a preferred embodiment, the housing 10 has positioning columns 11, and the light blocking member 30 has corresponding positioning grooves 31 for pre-positioning the installation position of the light blocking member 30 on the housing 10. In this embodiment, the positioning grooves 31 are first positioned on the positioning columns 11, and then the light blocking member 30 is fixed on the housing 10 by screws after the position of the light blocking member 30 is positioned. Preferably, the positioning columns 11 and the positioning grooves 31 have at least two pairs, that is, the housing 10 has at least two positioning columns 11, and the light blocking member 30 has at least two corresponding positioning grooves 31, wherein the size of at least one pair of positioning columns 11 and positioning grooves 31 is greater than the cross-sectional area of the positioning column 11, so that the positioning column 11 can move in the positioning groove 31 with larger size, thereby used for fine adjustment of the position of the light blocking member 30; at the same time, the above-mentioned light blocking member 30 can also match the tolerance between parts or be used for different models of the housing 10, so that the light blocking member 30 has stronger universality.

[0047] In summary, the optical engine and the projection device provided by the present application, the optical engine includes a housing, a light combining prism and a light blocking member, wherein the light blocking member is installed on the housing and located on the stray light out of the light combining prism. The light blocking member is used to block the stray light from shining on the housing. The light blocking member has a first opening corresponding to the light outlet of the housing. By using the light blocking member to block the stray light from shining on the housing, the stray light can be prevented from directly shining on the housing, thereby avoiding the aging and deformation of the housing due to heat.

[0048] The present application has been described by the above-mentioned related embodiments, however, the above-mentioned embodiments are only examples for implementing the present application. It must be pointed out that the disclosed embodiments do not limit the scope of the present application. On the contrary, modifications and improvements made without departing from the spirit and scope of the present application are also within the scope of the patent protection of the present application.

Claims

1. An optical engine, comprising: Comprising: a housing having a light exit opening; a light combiner prism mounted on the housing, the light combiner prism for projecting effective image light out of the light exit opening; and a light blocking member mounted on the housing and located on a light exit path of stray light from the light combiner prism; wherein the light blocking member is for blocking the stray light from shining on the housing; the light blocking member has a first opening corresponding to the light exit opening.

2. The optical engine of claim 1, wherein, At least part of the light blocking member has a gap with the housing.

3. The optical engine of claim 1, wherein, The surface of the light blocking member has an anti-reflection layer.

4. The optical engine of claim 1, wherein, The light blocking member has a frame portion and an extension portion; wherein the frame portion is fixed to the housing, the first opening is located on the frame portion to expose the light exit opening of the housing; the extension portion is further for heat dissipation.

5. The optical engine of claim 4, wherein, The extension portion is coplanar with the frame portion; or the extension portion is bent relative to the frame portion.

6. The optical engine of claim 4, wherein, The extension portion is planar; or the extension portion is wavy; or the extension portion is a fin.

7. The optical engine of claim 1, wherein, The frame portion is inclined to the propagation direction of the light from the light combiner prism so that the stray light is not reflected by the frame portion towards the light combiner prism.

8. The optical engine of claim 1, wherein, The light blocking member is fixed to the housing by screws or hooks, wherein the screws or the hooks are located away from the illumination area of the stray light.

9. The optical engine of claim 1, wherein, The light blocking member is embedded in the housing.

10. A projection apparatus, characterized by, Comprising: a housing; an optical engine according to any one of claims 1 to 9 mounted in the housing; and a lens mounted in the housing, the lens being located on a light exit path of the optical engine.

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