CN115793357A - Liquid crystal projection system - Google Patents

Abstract

The application provides a liquid crystal projection system, which comprises a first light source component, a second light source component, a third light source component, a first liquid crystal panel, a second liquid crystal panel, a third liquid crystal panel, a light combining prism and a projection lens, wherein the second liquid crystal panel and the third liquid crystal panel are oppositely arranged on two sides of the first liquid crystal panel in the width direction, and the length directions of the first liquid crystal panel, the second liquid crystal panel and the third liquid crystal panel are consistent; the light combining prism is arranged among the first liquid crystal panel, the second liquid crystal panel and the third liquid crystal panel, and the length of the light combining prism in the light outgoing direction of the first liquid crystal panel is matched with the width of the second liquid crystal panel and the third liquid crystal panel; the projection lens is used for projecting the synthetic light emitted by the light-combining prism onto a screen to form a projection image. The liquid crystal projection system provided by the application can reduce the length of the light combination prism in the light outgoing direction of the first liquid crystal panel and the rear intercept of the projection lens, so that the whole liquid crystal projection system is compact in structure.

Description

Liquid crystal projection system

Technical Field

The application relates to the technical field of optical systems, in particular to a liquid crystal projection system.

Background

The 3LCD (Liquid Crystal Display) projection system is a common Liquid Crystal projection system, and the basic principle of the 3LCD projection system is to separate white light emitted by a white light illumination light source into red, green and blue lights through a dichroic mirror, the three lights are respectively incident on three corresponding Liquid Crystal panels, the Liquid Crystal panels modulate incident light beams according to input image signals, and then combine the light beams emitted by the three Liquid Crystal panels into a combined light through a light combining prism, and the combined light can form a color image on a screen after being projected to the screen through a projection lens. However, the pixel size of the liquid crystal panel is large (usually above 25 um), and in the case of a certain resolution, the size of the whole liquid crystal panel is large, which results in a large size of the light combining prism, and a long back intercept of the projection lens, which finally results in a large size of the whole projection system.

Disclosure of Invention

The present application is directed to a liquid crystal projection system to solve the above problems. The present application achieves the above object by the following technical solutions.

The application provides a liquid crystal projection system, including: the first light source component, the second light source component and the third light source component are respectively used for emitting first color light, second color light and third color light; the liquid crystal display device comprises at least three liquid crystal panels, a liquid crystal display panel and a liquid crystal display panel, wherein the liquid crystal panels comprise a first liquid crystal panel, a second liquid crystal panel and a third liquid crystal panel; the first liquid crystal panel, the second liquid crystal panel and the third liquid crystal panel are respectively provided with a length direction and a width direction, the second liquid crystal panel and the third liquid crystal panel are oppositely arranged at two sides of the width direction of the first liquid crystal panel, and the length directions of the first liquid crystal panel, the second liquid crystal panel and the third liquid crystal panel are consistent; the light combining prism is arranged among the first liquid crystal panel, the second liquid crystal panel and the third liquid crystal panel, the length of the light combining prism in the light outgoing direction of the first liquid crystal panel is matched with the width of the second liquid crystal panel and the width of the third liquid crystal panel, and the light combining prism is used for combining light beams emitted by the first liquid crystal panel, the second liquid crystal panel and the third liquid crystal panel into combined light; and the projection lens is arranged on the emergent light path of the light combination prism and used for projecting the combined light onto a screen to form a projection image.

Compared with the prior art, the liquid crystal projection system provided by the embodiment of the application has the advantages that the second liquid crystal panel and the third liquid crystal panel are oppositely arranged on two sides of the first liquid crystal panel in the width direction, and the length directions of the first liquid crystal panel, the second liquid crystal panel and the third liquid crystal panel are consistent, so that the length of the light combination prism in the light emergent direction of the first liquid crystal panel can be adapted to the width of the second liquid crystal panel and the width of the third liquid crystal panel, the length of the light combination prism in the light emergent direction of the first liquid crystal panel and the back intercept of the projection lens can be reduced, and the whole liquid crystal projection system is compact in structure.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the description below are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic diagram of a 3LCD projection system provided in the related art.

Fig. 2 is a side view of a liquid crystal panel and a light-combining prism in the 3LCD projection system shown in fig. 1.

Fig. 3 is a schematic diagram of the structures of the liquid crystal panel and the light-combining prism in the 3LCD projection system shown in fig. 1.

Fig. 4 is a schematic diagram of a liquid crystal projection system provided in an embodiment of the present application.

Fig. 5 is a side view of the liquid crystal panel and the x-cube in the liquid crystal projection system shown in fig. 4.

Fig. 6 is a schematic diagram of the structures of the liquid crystal panel and the light-combining prism in the liquid crystal projection system shown in fig. 4.

FIG. 7 is a schematic diagram of a liquid crystal projection system according to another embodiment of the present application.

FIG. 8 is a schematic view of a liquid crystal projection system according to yet another embodiment of the present application.

FIG. 9 is a schematic view of a liquid crystal projection system according to yet another embodiment of the present application.

FIG. 10 is a schematic diagram of a liquid crystal projection system according to yet another embodiment of the present application.

Fig. 11 is a schematic diagram of the structure of the polarizing shaper in the liquid crystal projection system shown in fig. 10.

Detailed Description

Reference will now be made in detail to embodiments of the present application, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative and are only for the purpose of explaining the present application and are not to be construed as limiting the present application.

Referring to fig. 1, in a related art, a 3LCD projection system 100 is provided, in which a white light illumination light source 101 passes through a light uniformizing device 102, and then obtains a linearly polarized light source through a polarization conversion device 103, and then performs color separation through a first dichroic mirror 104 to form blue light, green light, and red light, the blue light is reflected by the first dichroic mirror 104 and a first reflecting mirror 105, and then irradiates onto a corresponding polarizer 106, and enters a blue liquid crystal panel 107 in a single polarization state, the blue liquid crystal panel 107 performs pixelization control on the polarization state of the illumination light, and then passes through an analyzer 108 to form blue light carrying blue image information. The rest light except the blue light penetrates through the first dichroic mirror 104 and is incident to the second dichroic mirror 109, at this time, the green light is reflected to the green light liquid crystal panel 110, and the green light carrying the green image information is formed after being modulated by the green light liquid crystal panel 110; the red light can pass through the second dichroic mirror 104, and is reflected by the second reflecting mirror 111 and the third reflecting mirror 112 to irradiate onto the red light liquid crystal panel 113, and is modulated by the red light liquid crystal panel 113 to form red light carrying red image information, the three-color light carrying the image information is processed by the light combination of the light combination prism 114 to form a beam of combined light, and the combined light is projected and displayed by the projection lens 115.

The liquid crystal panel is usually manufactured by a Low Temperature Poly-Silicon (LTPS) liquid crystal process, which has a Low cost but a Low precision, resulting in a large pixel size (usually over 25 um), and the size of the entire liquid crystal panel is large when a certain resolution is satisfied.

Referring to fig. 1 to 3, the green liquid crystal panel 110, the red liquid crystal panel 113 and the blue liquid crystal panel 107 are all rectangular plate-shaped structures and have the same size. In the 3LCD projection system 100, the length direction of the green liquid crystal panel 110 is perpendicular to the length directions of the red liquid crystal panel 113 and the blue liquid crystal panel 107, and the width directions of the green liquid crystal panel 110, the red liquid crystal panel 113 and the blue liquid crystal panel 107 are consistent, the length of the light combining prism 114 in the light emitting direction of the green liquid crystal panel 110 needs to be matched with the length of the red liquid crystal panel 113 and the blue liquid crystal panel 107, for example, the length of the light combining prism 114 in the light emitting direction of the green liquid crystal panel 110 needs to be equal to the length of the red liquid crystal panel 113, which results in a larger length of the light combining prism 114 in the light emitting direction of the green liquid crystal panel 110, and further results in a longer back intercept of the projection lens 115, and finally results in a larger size of the entire 3LCD projection system 100. The light emitting direction of the green liquid crystal panel 110 is perpendicular to the green liquid crystal panel 110.

In order to solve the above problems, the present application provides a liquid crystal projection system, in which the second liquid crystal panel and the third liquid crystal panel are oppositely disposed on two sides of the first liquid crystal panel in the width direction, and the length directions of the first liquid crystal panel, the second liquid crystal panel and the third liquid crystal panel are the same (see fig. 5 and fig. 6 in detail), so that the length of the light combining prism in the light exit direction of the first liquid crystal panel only needs to be matched with the width of the second liquid crystal panel and the third liquid crystal panel, for example, the length of the light combining prism in the light exit direction of the first liquid crystal panel is equal to the width of the second liquid crystal panel, and does not need to be matched with the length of the second liquid crystal panel and the third liquid crystal panel, thereby the length of the light combining prism in the light exit direction of the first liquid crystal panel and the back intercept of the projection lens can be reduced, and the entire liquid crystal projection system is compact in structure.

In order to make the technical solutions better understood by those skilled in the art, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It is to be understood that the embodiments described are only a few embodiments of the present application and not all embodiments. All other embodiments obtained by a person skilled in the art based on the embodiments in the present application without making any creative effort belong to the protection scope of the present application.

Fig. 4 is a schematic structural diagram of a liquid crystal projection system 200 according to an embodiment of the disclosure, and referring to fig. 4, fig. 5, and fig. 6, the liquid crystal projection system 200 may include a first light source assembly 210, a second light source assembly 220, a third light source assembly 230, at least three liquid crystal panels (241, 242, 243), a light combining prism 250, and a projection lens 260, where the at least three liquid crystal panels include a first liquid crystal panel 241, a second liquid crystal panel 242, and a third liquid crystal panel 243.

The first light source assembly 210 is configured to emit a first color light, the second light source assembly 220 is configured to emit a second color light, and the third light source assembly 230 is configured to emit a third color light. The first liquid crystal panel 241 is used for modulating the first color light, the second liquid crystal panel 242 is used for modulating the second color light, and the third liquid crystal panel 243 is used for modulating the third color light. The first, second, and third liquid crystal panels 241, 242, and 243 are each of a rectangular plate-shaped structure, and each has a length direction and a width direction. The second liquid crystal panel 242 and the third liquid crystal panel 243 are disposed opposite to each other on both sides of the first liquid crystal panel 241 in the width direction, and the first liquid crystal panel 241, the second liquid crystal panel 242, and the third liquid crystal panel 243 have the same longitudinal direction.

The light combining prism 250 is disposed between the first liquid crystal panel 241, the second liquid crystal panel 242, and the third liquid crystal panel 243, and the length of the light combining prism 250 in the light emitting direction of the first liquid crystal panel 241 is adapted to the width of the second liquid crystal panel 242 and the third liquid crystal panel 243, and the light combining prism 250 is configured to combine the light beams emitted by the first liquid crystal panel 241, the second liquid crystal panel 242, and the third liquid crystal panel 243 into a combined light; the projection lens 260 is disposed on an exit light path of the light combining prism 250, and projects the combined light emitted from the light combining prism 250 onto a screen to form a projection image. The light emitting direction of the first liquid crystal panel 241 is perpendicular to the first liquid crystal panel 241.

Therefore, the length of the light combining prism 250 in the light outgoing direction of the first liquid crystal panel 241 only needs to be matched with the width of the second liquid crystal panel 242 and the third liquid crystal panel 243, and does not need to be matched with the length of the second liquid crystal panel 242 and the third liquid crystal panel 243, so that the length of the light combining prism 250 in the light outgoing direction of the first liquid crystal panel 241 and the back intercept of the projection lens 260 can be reduced, and the whole liquid crystal projection system 200 is more compact. In addition, compared with a projection system with single light source illumination, the liquid crystal projection system 200 adopts three light sources for illumination, and light splitting is not needed through a dichroic mirror, so that a light path system is simpler.

In the present embodiment, the first liquid crystal panel 241, the second liquid crystal panel 242, and the third liquid crystal panel 243 may be identical in size or may be different in size. When the sizes of the second liquid crystal panel 242 and the third liquid crystal panel 243 are not the same, the length of the light combining prism 250 in the light emitting direction of the first liquid crystal panel 241 is matched with the larger value of the width of the second liquid crystal panel 242 and the width of the third liquid crystal panel 243, for example, the width of the second liquid crystal panel 242 is greater than the width of the third liquid crystal panel 243, and the length of the light combining prism 250 in the light emitting direction of the first liquid crystal panel 241 is matched with the width of the second liquid crystal panel 242.

Further, the length of the light combining prism 250 in the light outgoing direction of the first liquid crystal panel 241 is matched with the width of the second liquid crystal panel 242 and the third liquid crystal panel 243, which may be that the length of the light combining prism 250 in the light outgoing direction of the first liquid crystal panel 241 is equal to the width of the second liquid crystal panel 242 and the third liquid crystal panel 243, or may also be that the length of the first liquid crystal panel 241 in the light outgoing direction is slightly smaller than or slightly larger than the width of the second liquid crystal panel 242 and the third liquid crystal panel 243.

In this embodiment, the light combining prism 250 may be a cross dichroic color combining prism (abbreviated as "X-cube"), which is formed by combining four triangular prisms and can combine red light, green light, and blue light to form a color image.

In this embodiment, each of the first light source assembly 210, the second light source assembly 220, and the third light source assembly 230 includes an illumination light source 240, a collection device 250, a polarization device 260, and a polarization detection device (not shown), the collection device 250 and the polarization device 260 are sequentially disposed on an exit light path of the illumination light source 240, the polarization detection device is disposed on a light path between a corresponding liquid crystal panel and the light combination prism 250, a light beam emitted by the illumination light source 240 enters the polarization device 260 after being collimated by the collection device 250, and exits from the polarization device 260 to the corresponding liquid crystal panel in a single polarization state, and the liquid crystal panel modulates light according to an input image signal to form image light carrying image information. The polarization analyzer is used for polarization analysis of the polarized light, so as to filter out the light beam meeting the requirement of polarization state in the image light to the light combining prism 250.

The illumination light source 240 may be an LED lamp or a fluorescent laser, among others. In the embodiments, the first light source 240G is used as the illumination light source of the first light source assembly 210, the second light source 240R is used as the illumination light source of the second light source assembly 220, and the third light source 240B is used as the illumination light source of the third light source assembly 230. As an example, the first light source 240G is for emitting green light, the second light source 240R is for emitting red light, and the third light source 240B is for emitting blue light.

In this embodiment, the collecting device 250 may include a tapered light uniformizing device 251 and a lens 252, the tapered light uniformizing device 251 and the lens 252 are sequentially disposed on an exit light path of the illumination light source 240, and a light beam emitted by the illumination light source 240 is collimated by the tapered light uniformizing device 251 and the lens 252 to form parallel light incident on the polarization generator 260.

The tapered dodging device 251 is provided with an incident surface on the side facing the illumination light source 240, and an exit surface on the side facing the lens 252, and the area of the incident surface is smaller than that of the exit surface. After light beams emitted by the illumination light source 240 enter the tapered dodging device 251 through the incident surface, the light beams are reflected by the inner side wall of the tapered dodging device 251 and then are emitted out through the emergent surface, so that the area of emergent light spots is larger than that of incident light spots, and the divergence angle of the light beams is reduced. In this embodiment, the tapered light homogenizing device 251 can be a solid tapered light guiding rod. In other embodiments, the tapered dodging device 251 may also be a hollow tapered reflector.

The lens 252 may be a convex lens or a fresnel lens, and the light beam can be adjusted to be parallel light by the convex lens or the fresnel lens cooperating with the tapered dodging device 251.

In this embodiment, the polarizing device 260 may be a polarizer, such as a polarizer, a nicols, or the like. The emergent light of the collecting device 250 is unpolarized light, and the unpolarized light emitted by the collecting device 250 enters the polarizer and then is emitted from the polarizer in a single polarization state.

In some other embodiments, the polarizing device 260 may also be a reflective polarizer, after the unpolarized light emitted from the collecting device 250 enters the reflective polarizer, part of the light passes through the reflective polarizer and continues to emit in a single polarization state, part of the light is reflected by the reflective polarizer and returns to the tapered dodging device 251, is reflected back and forth by the tapered dodging device 251, and then exits through the exit surface of the tapered dodging device 251 to reach the reflective polarizer, thereby improving the utilization rate of the light beam. In order to reduce the recycling times of the recycled light beam, a quarter-wave plate may be disposed in the tapered dodging device 251 to change the polarization state of the light beam.

In this embodiment, the liquid crystal projection system 200 may further include a pixel shifting device 270, where the pixel shifting device 270 is disposed on the light path between the light combining prism 250 and the projection lens 260, and is configured to translate the combined light emitted by the light combining prism 250 along a direction perpendicular to the optical axis, and superimpose the combined light at different translation positions in time sequence, so as to implement a small displacement of the image, and further implement an improvement of the display resolution.

The pixel shift device 270 may be a transparent flat optical device using XPR (pixel shift resolution system) technology, and the rotation angle of the transparent flat optical device may be controlled by current or voltage. Specifically, when the transparent flat plate of the pixel shifting device 270 rotates by a certain angle, light passing through the transparent flat plate is refracted twice and then translated as a whole, and the transparent flat plate stays at the rotating position for a predetermined time and then rotates to other positions. In one image frame period, the pixel shifting device 270 may include 2 or 4 stable states, the image is divided into 2 or 4 sub-frames, and the human eye superimposes the captured 2 or 4 images through a time integration function, thereby forming a high resolution image in the brain. It will be appreciated that the pixel shifting means 270 may also include more stable states to achieve higher resolution, and the invention is not limited to the number of pixel multiplications.

In other embodiments, the pixel shifting device 270 may also be a liquid crystal birefringence device using an E-shift (pixel expansion) technology, and the deflection angle of liquid crystal molecules is controlled by voltage, so as to translate light passing through the liquid crystal birefringence device, thereby implementing the function of whole pixel shifting, and the effect is similar to the above-mentioned pixel shifting device 270 with mechanical rotation, and is not described herein again.

When the pixel shifting arrangement 270 uses XPR technology, there is no requirement for the polarization state of the incident light. When the pixel shifting device 270 employs the E-shift technology, the light entering the pixel shifting device 270 is required to be light of the same polarization state. In the liquid crystal projection system 200, in order to maximize efficiency, generally, green light passes through the light combining prism 250 in a P-polarization state, and red light and blue light pass through the light combining prism 250 in an S-polarization state, which utilizes that the width of a high reflection region of P-polarization is always smaller than that of S-polarization at oblique incidence, so that the transmission region of P-polarized light in RDM (anti-red film) and BDM (anti-blue film) of the light combining prism 250 can be made very wide, thereby realizing almost lossless spectrum passing through the light combining prism 250. When the pixel shift device 270 employs the E-shift technology, there are two methods to make the light entering the pixel shift device 270 all be light in the same polarization state, one of the methods is to cut the spectrum, specifically, a color filter may be added to each of the light paths of the first color light, the second color light, and the third color light by cutting the spectrum, or the light combining prism 250 has a filtering function, and the filtering can be implemented by the light combining prism 250. Alternatively, a COLOR separator may be added to the optical path between the light combining prism 250 and the pixel shift device 270 to convert the polarization of light with a specific wavelength, such as red and blue light, into P-polarization or green light into S-polarization, so that all incident light is incident on the pixel shift device 270 with the same polarization.

In this embodiment, the projection lens 260 may be a lens group composed of a plurality of lenses, and the aperture stop of the projection lens 260 may be disposed outside the projection lens 260, for example, at the foremost of the whole lens group, or at the rearmost of the whole lens group, so that the projection lens 260 can be miniaturized and the cost of the projection lens 260 can be reduced.

Fig. 7 is a schematic structural diagram of a liquid crystal projection system 200 according to another embodiment of the present disclosure, please refer to fig. 7, in some embodiments, the liquid crystal projection system 200 further includes a fourth light source assembly 280, the first light source assembly 210 further includes a first light splitting prism 211, the first light splitting prism 211 is disposed on an optical path of the fourth light source assembly 280 and located between the collecting device 250 of the first light source assembly 210 and the polarization generating device 260, a light beam emitted by the fourth light source assembly 280 is guided to the illumination light source 240 of the first light source assembly 210 through the first light splitting prism 211 to excite and generate an excitation light, and a light beam emitted by the illumination light source 240 of the first light source assembly 210 is transmitted to the polarization generating device 260 through the first light splitting prism 211. This enables double-sided excitation of the first light source 240G, and increases the maximum output lumens of the first light source 240G.

In the present embodiment, the fourth light source assembly 280 includes an illumination source 240 and a collecting device 250, and the fourth light source 212B is used as the illumination source of the fourth light source assembly 280 in the present embodiment. The collecting device 250 may include a tapered dodging device 251 and a lens 252, and the light beam emitted by the fourth light source 212B is collimated by the tapered dodging device 251 and the lens 252 to form parallel light and then enters the first light splitting prism 211. The first beam splitter prism 211 is provided with a beam splitting surface, the beam splitting surface of the first beam splitter prism 211 forms an included angle of 45 degrees with the optical axes of the first light source assembly 210 and the fourth light source assembly 280, and the beam splitting surface of the first beam splitter prism 211 is coated with a transparent and reflective film so as to reflect the light beam emitted by the fourth light source 212B to the first light source 240G and transmit the light beam emitted by the first light source 240G. The light beam emitted by the first light source 240G includes the excitation light generated by the fourth light source 212B and the light beam generated by itself.

As an example, the first light source 240G is a green light source, the fourth light source 212B is a blue light source, a blue-reflecting yellow-transmitting film is coated on a splitting surface of the first beam splitter prism 211, blue light emitted by the fourth light source 212B is reflected to the collecting device 250 of the first light source assembly 210 through the blue-reflecting yellow-transmitting film, and finally irradiates on green phosphor of the first light source 240G to form double-sided excitation of the green phosphor, thereby increasing the maximum output lumens of the first light source 240G.

In other embodiments, the first beam splitter prism 211 can also be disposed on the optical path of the second light source assembly 220 or the third light source assembly 230, so as to form double-sided excitation for the second light source 240R or the third light source 240B by the fourth light source 212B.

Fig. 8 is a schematic structural diagram of a liquid crystal projection system 200 according to yet another embodiment of the present disclosure, and referring to fig. 8, in some embodiments, the liquid crystal projection system 200 may further include a fifth light source module 290 in addition to the fourth light source module 280. Specifically, the second light source assembly 220 further includes a second light splitting prism 221, the second light splitting prism 221 is disposed on an optical path of the fifth light source assembly 290 and located between the collecting device 250 and the polarization device 260 of the second light source assembly 220, a light beam emitted by the fifth light source assembly 290 is guided to the illumination light source 240 of the second light source assembly 220 through the second light splitting prism 221 to excite and generate an excitation light, and a light beam emitted by the illumination light source 240 of the second light source assembly 220 is transmitted to the polarization device 260 through the second light splitting prism 221.

In the present embodiment, the fifth light source assembly 290 includes the illumination light source 240 and the collecting device 250, and in the present embodiment, the fifth light source 222B is used as the illumination light source of the fifth light source assembly 290. The collecting device 250 may include a tapered dodging device 251 and a lens 252, and the light beam emitted by the fifth light source 222B is collimated by the tapered dodging device 251 and the lens 252 to form parallel light and then enters the second beam splitting prism 221. The second beam splitter prism 221 is provided with a beam splitting surface, the beam splitting surface of the second beam splitter prism 221 forms an included angle of 45 degrees with the optical axes of the second light source assembly 220 and the fifth light source assembly 290, and the beam splitting surface of the second beam splitter prism 221 is coated with a transparent and reflective film for reflecting the light beam emitted by the fifth light source 222B to the second light source 240R and transmitting the light beam emitted by the second light source 240R. The light beam emitted by the second light source 240R includes the excitation light excited by the fifth light source 222B and the light beam generated by itself.

As an example, the second light source 240R is a red light source, the fifth light source 222B is a blue light source, a blue-green and red-transparent film is coated on a splitting surface of the second beam splitter prism 221, blue light emitted by the fifth light source 222B is reflected to the collecting device 250 of the second light source assembly 220 through the blue-green and red-transparent film, and finally irradiates red phosphor of the second light source 240R, so as to form double-sided excitation of the red phosphor, and improve the maximum output lumen of the second light source 240R.

In some other embodiments, the liquid crystal projection system 200 can further include a sixth light source module and a third light splitting prism, the third light splitting prism is disposed on the optical path of the sixth light source module and located between the collecting device 250 and the polarizing device 260 of the third light source module 230, so as to form a double-sided excitation for the third light source 240B, and increase the maximum output lumens of the third light source 240B.

Fig. 9 is a schematic structural diagram of a liquid crystal projection system 200 according to another embodiment of the present disclosure, please refer to fig. 9, in some embodiments, the optical axes of the collecting device 250 and the polarization generating device 260 of the second light source module 220 intersect, the second light source module 220 further includes a light guiding prism 223, the light guiding prism 223 is disposed on the optical path between the collecting device 250 and the polarization generating device 260, and the light beam emitted from the collecting device 250 is guided to the polarization generating device 260 through the light guiding prism 223. Therefore, the light path of the second light source assembly 220 can be turned, and the light path of the second light source assembly 220 can be adjusted according to actual requirements, so that the whole light path system is more compact, and the size is reduced.

In this embodiment, the optical axes of the collecting device 250 of the second light source assembly 220 and the polarizing device 260 are perpendicular to each other, the light guide prism 223 may be a right-angle light guide prism, the incident surface and the emergent surface of the right-angle light guide prism are perpendicular to each other, the right-angle light guide prism further has a total reflection surface, and the total reflection surface and the incident surface and the emergent surface of the right-angle light guide prism both form an included angle of 45 °.

The second light source assembly 220 may further include a hollow light pipe 224, the hollow light pipe 224 is disposed on the light path between the collecting device 250 and the right-angle light guide prism, the incident surface and the emergent surface of the hollow light pipe 224, and the incident surface and the emergent surface of the right-angle light guide prism are both in accordance with the shape of the light spot emitted from the collecting device 250, and the total reflection surface of the right-angle light guide prism may form an included angle of 45 degrees with the optical axis of the collecting device 250, so that an optical waveguide may be formed, and the optical expansion amount is maintained while the light path is folded; meanwhile, by controlling the length of the hollow light guide 224, the first light source 240G and the second light source 240R may be placed on the same substrate.

In some embodiments, the optical axes of the collecting device 250 and the polarizing device 260 of the third light source assembly 230 intersect, the third light source assembly 230 may also include a light guide prism 223 and a hollow light guide 224 to maintain the etendue while the light path is folded, and the second light source assembly 220 and the third light source assembly 230 simultaneously perform the light path folding through the light guide prism 223 and the hollow light guide 224, so that the volume of the whole liquid crystal projection system 200 is minimized.

In other embodiments, the optical axes of the collecting device 250 and the polarizing device 260 of the first light source assembly 210 intersect, and the first light source assembly 210 may also include a light guide prism 223 and a hollow light guide 224. For the specific structures and positions of the light guide prism 223 and the hollow light guide tube 224 in the light path, reference may be made to the above-mentioned related descriptions of the second light source assembly 220, and details thereof are not repeated herein.

Fig. 10 is a schematic structural diagram of a liquid crystal projection system 200 according to another embodiment of the present disclosure, referring to fig. 10, in some embodiments, the polarizing device 260 may be a polarizing shaper 261, the light beam emitted from the collecting device 250 is shaped by the polarizing shaper 261 to form image light having a predetermined spot shape, and recovered light, the image light is irradiated to the corresponding liquid crystal panel, and the recovered light is reflected by the polarizing shaper 261 back to the collecting device 250, so as to implement light recycling, thereby improving the light efficiency of the system.

In this embodiment, the collecting device 250 may be a collecting lens, and the light beam emitted by the illumination source 240 is shaped into parallel light by the collecting lens. The collecting lens may be a plano-convex lens or a biconvex lens, and the number of collecting lenses may include one or more. For example, the number of the collecting lenses includes two, and the two collecting lenses are sequentially disposed along the exit optical path of the illumination light source 240.

As an example, the shape of the light spot emitted by the collecting device 250 is a circle, and the area to be illuminated by the first liquid crystal panel 241 is a rectangle, then the preset light spot shape of the image light is a rectangle adapted to the first liquid crystal panel 241, at this time, the rectangular light spot can be cut out from the circular light spot by the polarization shaper 261, and the image light with the rectangular light spot is formed to illuminate the first liquid crystal panel 241, and the recycled light not participating in the illumination is reflected back to the collecting device 250. When the collecting device 250 comprises the tapered dodging device 251 (see fig. 9), the recycled light can be directly recycled by the tapered dodging device 251; when the collecting device 250 is a collecting lens, the recycled light can pass through the collecting lens and return to the first light source 240G, and the first light source 240G can reflect the recycled light back to the collecting lens to continue to participate in the light circulation.

In other embodiments, the light spot shape emitted by the collecting device 250 is rectangular, and the area to be illuminated by the first liquid crystal panel 241 is circular, so that the preset light spot shape of the image light is circular to fit the first liquid crystal panel 241, and then the circular light spot can be cut out from the rectangular light spot by the polarization shaper 261 to meet the illumination requirement of the first liquid crystal panel 141.

Referring to fig. 10 and fig. 11, in the present embodiment, the polarization shaper 261 may be a polarization shaping film, the polarization shaper 261 is provided with a first region 2611 and a second region 2612, the first region 2611 is disposed around the periphery of the second region 2612, and the shape of the second region 2612 is adapted to the illumination region of the liquid crystal panel, for example, when the illumination region of the liquid crystal panel is rectangular, the first region 2611 is rectangular. The first region 2611 may be coated with a reflective film and the second region 2612 may be coated with a light recycling film, such that when the light beam emitted from the collecting device 250 passes through the polarization shaper 261, a portion of the light is transmitted through the light recycling film of the second region 2612 to form image light, and the remaining portion is reflected by the reflective film of the first region 2611 to form recycled light.

In this embodiment, the polarizing shaper 261 may be a reflective polarizer, and in this case, the light recycling film plated on the second region 2612 may be a reflective polarizer, such as a reflective brightness enhancement film (DBEF) or a metal wire grid. Therefore, the polarization shaper 261 can also be used to split the image light into the first polarized light and the second polarized light with a polarization state different from that of the first polarized light, the first polarized light is irradiated to the corresponding liquid crystal panel, and the second polarized light is reflected back to the collecting device 250, so that the recycling of the second polarized light can be realized, and the system efficiency can be further improved.

As an example, the green image light is split into P-polarized light and S-polarized light by the reflective polarizer 262, wherein the P-polarized light is irradiated to the corresponding first liquid crystal panel 241, the S-polarized light is reflected back to the collecting device 250 and can be returned to the first light source 240G through the collecting device 250, and when the first light source 240G is an LED lamp or laser fluorescence, the S-polarized light can be dispersed into natural light again and then continuously participate in light circulation.

Although the present application has been described with reference to a preferred embodiment, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (12)

1. A liquid crystal projection system, comprising:

the first light source component, the second light source component and the third light source component are respectively used for emitting first color light, second color light and third color light;

at least three liquid crystal panels including a first liquid crystal panel, a second liquid crystal panel and a third liquid crystal panel, wherein the first liquid crystal panel is used for modulating the first color light, the second liquid crystal panel is used for modulating the second color light, and the third liquid crystal panel is used for modulating the third color light; the first liquid crystal panel, the second liquid crystal panel and the third liquid crystal panel are respectively provided with a length direction and a width direction, the second liquid crystal panel and the third liquid crystal panel are oppositely arranged on two sides of the width direction of the first liquid crystal panel, and the length directions of the first liquid crystal panel, the second liquid crystal panel and the third liquid crystal panel are consistent;

the light combining prism is arranged among the first liquid crystal panel, the second liquid crystal panel and the third liquid crystal panel, the length of the light combining prism in the light outgoing direction of the first liquid crystal panel is matched with the width of the second liquid crystal panel and the width of the third liquid crystal panel, and the light combining prism is used for combining light beams emitted by the first liquid crystal panel, the second liquid crystal panel and the third liquid crystal panel into combined light; and

and the projection lens is arranged on the emergent light path of the light combination prism and used for projecting the combined light onto a screen to form a projected image.

2. The liquid crystal projection system of claim 1, wherein the first light source assembly, the second light source assembly, and the third light source assembly each include an illumination source, a collection device, and a polarization device, the collection device and the polarization device are sequentially disposed on an exit light path of the illumination source, and a light beam emitted by the illumination source is collimated by the collection device, then enters the polarization device, and exits from the polarization device in a single polarization state.

3. The liquid crystal projection system of claim 2, wherein the collecting device comprises a tapered dodging device and a lens, the tapered dodging device and the lens are sequentially disposed on an emergent light path of the illumination light source, and a light beam emitted by the illumination light source is collimated by the tapered dodging device and the lens.

4. The liquid crystal projection system of claim 2, wherein the polarizing device is a polarizing shaper, and wherein the light beam from the collecting device is shaped by the polarizing shaper to form image light having a predetermined spot shape and recycled light, the image light being directed to the corresponding liquid crystal panel, the recycled light being reflected back to the collecting device.

5. The liquid crystal projection system of claim 4, wherein the polarization shaper is a reflective polarizer, the polarization shaper further configured to split the image light into first polarized light and second polarized light having a different polarization state than the first polarized light, the first polarized light impinging on the corresponding liquid crystal panel, the second polarized light reflecting back to the collecting means.

6. The liquid crystal projection system of claim 4, wherein the collecting means is a collecting lens, and the light beam emitted by the illumination source is shaped into parallel light by the collecting lens.

7. The liquid crystal projection system of claim 2, wherein the optical axes of the collecting device and the polarizing device of the second light source assembly intersect, the second light source assembly further comprises a light guide prism disposed on the optical path between the collecting device and the polarizing device, and the light beam emitted from the collecting device is guided to the polarizing device through the light guide prism.

8. The liquid crystal projection system of claim 7, wherein the light guide prism is a right-angle light guide prism, the second light source assembly further comprises a hollow light guide tube disposed on the light path between the collecting device and the right-angle light guide prism, the incident surface and the emergent surface of the hollow light guide tube, and the incident surface and the emergent surface of the right-angle light guide prism are both shaped to correspond to the light spot emitted from the collecting device, and the right-angle light guide prism has a total reflection surface forming an angle of 45 degrees with the optical axis of the collecting device.

9. The liquid crystal projection system of claim 2, wherein the liquid crystal projection system further comprises a fourth light source assembly, the first light source assembly further comprises a first beam splitter prism, the first beam splitter prism is disposed on a light path of the fourth light source assembly and located between the collecting device and the polarizing device of the first light source assembly, a light beam emitted by the fourth light source assembly is guided to the illumination light source of the first light source assembly through the first beam splitter prism to be excited to generate an excitation light, and the light beam emitted by the illumination light source of the first light source assembly is transmitted to the polarizing device through the first beam splitter prism.

10. The liquid crystal projection system of claim 9, further comprising a fifth light source module, wherein the second light source module further comprises a second beam splitter prism, the second beam splitter prism is disposed on the optical path of the fifth light source module and located between the collecting device and the polarization device of the second light source module, the light beam emitted from the fifth light source module is guided to the illumination light source of the second light source module through the second beam splitter prism to excite and generate the excitation light, and the light beam emitted from the illumination light source of the second light source module is transmitted to the polarization device through the second beam splitter prism.

11. The liquid crystal projection system of any of claims 1-10, wherein the aperture stop of the projection lens is located outside the projection lens.

12. The liquid crystal projection system of any of claims 1-10, wherein the first color light is green light, the second color light is red light, and the third color light is blue light.

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