CN105824126B - Light source module and display device - Google Patents

Abstract

The present invention provides a light source module and a display device. The light source module has a main optical axis. The light source module includes a light source, an imaging unit, a spectroscopic unit, a first relay unit and a second relay unit. The spectroscopic unit has a transmission surface, a first reflection surface and a second reflection surface. The first reflection surface and the second reflection surface are symmetrically arranged. The light source provides light. The light passes through the imaging unit and the spectroscopic unit in sequence, and part of the light forms a first light beam and part of the light forms a second light beam. There is a first offset between the first optical axis of the first light beam and the main optical axis, and there is a second offset between the second optical axis of the second light beam and the main optical axis. The first offset is the same as the second offset, and the first offset and the second offset are opposite to each other in the offset direction relative to the main optical axis. The present disclosure can increase the resolvable field of view.

Description

Light source module and display device

technical field

The invention relates to a light source module, in particular to a light source module used for a display device and a display device using the light source module.

Background technique

In recent years, with the vigorous development of stereoscopic display technology, various commercial products have emerged, such as stereoscopic movies, stereoscopic TVs, etc., that apply this technology. Stereoscopic display technology is to transmit the left-eye image and right-eye image of different viewing angles to the left eye and right eye of the viewer in a time sequence, imitating the depth of field produced by the human eye due to parallax, and allowing the observer to watch the stereoscopic image .

In addition, it can also be divided into glasses-type, helmet-type and naked-eye stereoscopic display technologies according to whether additional equipment is required. Among them, naked-eye three-dimensional display technology is particularly concerned by the industry because it can be viewed directly with the naked eye without special three-dimensional glasses or special helmets.

The light source module of the existing naked-eye three-dimensional projection device provides multiple imaging at different angles to form multiple viewing zones, so that the left and right eyes of the viewer receive different images. When the observer is in different positions, he will receive different images and View images from different angles. Generally, naked-eye three-dimensional projection devices can be roughly divided into three types: configuring liquid crystal gratings (slits), configuring multiple projection devices, or matching optical scanning elements. However, the optical path design of the liquid crystal grating is complicated, and the configuration of multiple projection devices will make the entire display device too bulky. Therefore, in recent years, multiple light sources are used to provide stereoscopic images by combining light scanning elements.

But no matter which method is used, it must be equipped with an angle magnifying screen (such as a double-layer lenticular lens) so that the left and right eyes receive different images. The angle at which light can be resolved by the light source module will be related to the number of resolvable fields of view at the magnified screen imaging position (observer position). The larger the angle of entry, the more the number of resolvable fields of view. The range of light incidence angles that can be resolved by the light source module will be limited by its own etendue. Generally, the existing method of increasing etendue is to increase the imaging area of the digital micromirror device. However, as the number of fields of view increases, it is necessary to use a digital micromirror device with special specifications to achieve the required imaging area. less economical.

In view of this, how to provide a light source module and a display device that increase the number of viewing areas by increasing the etendue is an urgent problem to be solved in the industry.

Contents of the invention

In view of the above problems, the main purpose of the present invention is to provide a light source module and a display device that increase the number of resolvable viewing areas by increasing the etendue.

To achieve the above purpose, the present invention provides a light source module used in a display device. The light source module has a main optical axis. The light source module includes a light source, an imaging unit, a light splitting unit, a first relay unit and a second relay unit. The light splitting unit has a transmission surface, a first reflection surface and a second reflection surface. The first reflective surface and the second reflective surface are arranged symmetrically.

A light source provides light. The light passes through the imaging unit and the spectroscopic unit in sequence, part of the light forms the first light beam, and part of the light forms the second light beam. The first light beam is reflected by the first reflective surface and enters the first relay unit. Passed to the splitting unit, the first light beam passes through the splitting unit and exits.

The second light beam passes through the light splitting unit and enters the second relay unit, and the second relay unit transmits the second light beam to the second reflective surface of the light splitting unit, and the second light beam is reflected by the second reflective surface and leaves the light splitting unit.

There is a first offset between the first optical axis of the first light beam and the main optical axis, there is a second offset between the second optical axis of the second light beam and the main optical axis, and the first offset and the second The offsets are the same, and the offset directions of the first offset and the second offset relative to the main optical axis are opposite.

In a preferred embodiment of the present invention, the light source module has an aperture, and the offset between the first optical axis and the second optical axis is a quarter of the aperture.

In a preferred embodiment of the present invention, the imaging unit is a digital micromirror device or a liquid crystal display device.

In a preferred embodiment of the present invention, the light source is a laser light source or a laser light source array.

In a preferred embodiment of the present invention, a polarizing unit is further included, the light enters into the polarizing unit after leaving the imaging unit, and forms parallel polarized light or vertical polarized light.

In a preferred embodiment of the present invention, the first relay unit includes a first polarizer, and the first polarizer includes a black strip mask, a plurality of strip quarter-wave plates, and a mirror. The quarter-wave strips are arranged on the reflection mirror, and the black strip-shaped mask is arranged on the quarter-wave strips and is perpendicular to the arrangement direction of the quarter-wave strips.

In a preferred embodiment of the present invention, the first relay unit includes a first polarizer, and the first polarizer includes a black strip mask, a quarter-wave plate and a mirror, and the quarter-wave plate It is set on the reflector, and the black strip mask is set on the quarter wave plate.

In a preferred embodiment of the present invention, an optical scanning element is further included, the light is transmitted to the imaging unit through the optical scanning element, and the optical scanning element is deflected according to different timings to form a plurality of different images.

In a preferred embodiment of the present invention, the optical scanning element is a voice coil motor, a polygonal mirror or a micro-electromechanical mirror.

In a preferred embodiment of the present invention, the light splitting unit further includes a first sub-prism, a second sub-prism and a third sub-prism. The first sub-prism forms a transmission surface, the second sub-prism and the third sub-prism are arranged on the transmission surface of the first sub-prism, the first reflection surface is arranged on the side of the second sub-prism opposite to the third sub-prism, and the second reflection surface It is arranged on the side of the third sub-prism opposite to the second sub-prism.

The present invention also provides a display device, which includes a display screen and a light source module. The light source module has a main optical axis. The light source module includes a light source, an imaging unit, a light splitting unit, a first relay unit and a second relay unit. The light splitting unit has a transmission surface, a first reflection surface and a second reflection surface. The first reflective surface and the second reflective surface are arranged symmetrically.

A light source provides light. The light passes through the imaging unit and the spectroscopic unit in sequence, part of the light forms the first light beam, and part of the light forms the second light beam. The first light beam is reflected by the first reflective surface and enters the first relay unit. The light beam is delivered to the beam splitting unit.

The second light beam passes through the light splitting unit and enters the second relay unit, and the second relay unit transmits the second light beam to the second reflective surface of the light splitting unit, and the second light beam is reflected by the second reflective surface and transmitted to the light splitting unit. There is a first offset between the first optical axis of the first light beam and the main optical axis, there is a second offset between the second optical axis of the second light beam and the main optical axis, and the first offset and the second With the same offset, the first light beam and the second light beam are delivered to the display screen by the light splitting unit.

In a preferred embodiment of the present invention, the light source module has an aperture, and the offset between the first optical axis and the second optical axis is a quarter of the aperture.

In a preferred embodiment of the present invention, the imaging unit is a digital micromirror device or a liquid crystal display device.

In a preferred embodiment of the present invention, the light source is a laser light source or a laser light source array.

In a preferred embodiment of the present invention, the light source module further includes a polarizing unit, the light enters the polarizing unit after leaving the imaging unit, and forms parallel polarized light or vertical polarized light.

In a preferred embodiment of the present invention, the first relay unit includes a first polarizer, and the first polarizer includes a black strip mask, a plurality of strip quarter-wave plates, and a mirror. The quarter-wave strips are arranged on the reflection mirror, and the black strip-shaped mask is arranged on the quarter-wave strips and is perpendicular to the arrangement direction of the quarter-wave strips.

In a preferred embodiment of the present invention, the first relay unit includes a first polarizer, and the first polarizer includes a black strip mask, a quarter-wave plate and a mirror, and the quarter-wave plate It is set on the reflector, and the black strip mask is set on the quarter wave plate.

In a preferred embodiment of the present invention, the light source module further includes a light scanning element, through which the light is transmitted to the imaging unit, and the light scanning element is deflected according to different times to form a plurality of different images.

In a preferred embodiment of the present invention, the optical scanning element is a voice coil motor, a polygonal mirror or a micro-electromechanical mirror.

In a preferred embodiment of the present invention, the light splitting unit further includes a first sub-prism, a second sub-prism and a third sub-prism. The first sub-prism forms a transmission surface, the second sub-prism and the third sub-prism are arranged on the transmission surface of the first sub-prism, the first reflection surface is arranged on the side of the second sub-prism opposite to the third sub-prism, and the second reflection surface It is arranged on the side of the third sub-prism opposite to the second sub-prism.

In a preferred embodiment of the present invention, the display screen comprises a double-layer lenticular lens. The double-layer lenticular lens has two lenticular lens layers and an omnidirectional diffusion plate sandwiched between the lenticular lens layers.

In a preferred embodiment of the present invention, the display screen includes a polarizing unit, which is arranged on the light-incident side of the display screen, and light enters the polarizing unit to form parallel polarized light or vertical polarized light.

In a preferred embodiment of the present invention, an angle modulating member is further included, wherein the angle modulating member includes a plurality of refraction surfaces made of birefringent material.

In a preferred embodiment of the present invention, it also includes an angle modulating member, wherein the angle modulating member includes a polarizer, a plurality of strip half-wave plates and a saw-tooth prism, and the saw-tooth prism includes a plurality of refraction surfaces, and each The refraction surfaces are set corresponding to each of the strip half-wave plates.

Based on the above, the light source module provided in this embodiment can split the light into the first light beam and the second light beam by setting the first reflective surface on the transmission surface of the light splitting unit, and the first light beam and the second light beam Will enter the first relay unit and the second relay unit respectively. The optical axes of the first light beam and the second light beam entering the first relay unit and the second relay unit will have an offset relative to the main optical axis. Therefore, the angle of the light exiting the light source module can be increased (the etendue is increased), and the purpose of increasing the resolvable viewing area can be achieved without changing or increasing the imaging unit.

Description of drawings

FIG. 1 is a schematic diagram of a light source module of the present invention.

FIG. 2 is a partial view of the light source module in FIG. 1 .

FIG. 3 is an exploded schematic diagram of a light splitting unit of the light source module in FIG. 1 .

FIG. 4A is a schematic diagram of a first polarizer of a first relay unit.

FIG. 4B is a schematic cross-sectional view of FIG. 4A along the secant line AA.

FIG. 4C is a schematic diagram of another embodiment of the first polarizer of the first relay unit.

FIG. 4D is a schematic cross-sectional view of FIG. 4C along the secant line BB.

5 and 6 are equivalent imaging diagrams of the first and second relay units.

FIG. 7 is a schematic diagram of the projection device of the present invention.

FIG. 8 is an enlarged schematic view of an angle adjusting member of the projection device in FIG. 7 .

FIG. 9 is an enlarged schematic view of another embodiment of the angle adjusting member of the projection device in FIG. 7 .

Explanation of reference signs:

1, 21: Light source module

10: light source

11: Imaging unit

13: Light splitting unit

131: The first sub-prism

131a: transmission surface

132a: first reflective surface

132: Second sub-prism

133a: second reflective surface

133: The third sub-prism

14: The first relay unit

141: lens

142, 242: the first polarization piece

142a, 242a: quarter wave plate

142b, 242b: first mirror

142c: First black strip mask

15: Second relay unit

151: lens

152: The second polarized piece

16: Polarization unit

17: Optical scanning element

171: Actuating device

172: reflective surface

242c: second mirror matrix

242d: black strip mask

d1: first offset

d2: second offset

R: caliber

Z1, Z2: sub-caliber

2: Projection device

22: Display screen

221: double-layer lenticular lens

221a, 221b: lenticular lens layer

221c: omnidirectional diffuser

222: Collimation unit

224, 324: angle adjustment parts

224a: Refractive surface

324a: Jagged Prism

324b: Strip half-wave plate

324c: Polarizing plate

Detailed ways

A light source module and a projection device according to preferred embodiments of the present invention will be described below with reference to related drawings, wherein the same elements will be described with the same reference symbols.

Meanwhile, in the following embodiments and drawings, elements not directly related to the present invention have been omitted and not shown; and the dimensional relationship among the elements in the drawings is only for easy understanding, and is not intended to limit the actual ratio.

Please refer to FIG. 1 to FIG. 3 first. FIG. 1 is a schematic diagram of the light source module of the present invention. FIG. 2 is a partial view of the light source module in FIG. 1 . FIG. 3 is an exploded schematic diagram of a light splitting unit of the light source module in FIG. 1 .

The present invention provides a light source module 1 used in a display device. The display device exemplified herein may be a digital light processing device (Digital Light Processing; DLP), a projection display or a liquid crystal projection device (Liquid Crystal Display; LCD), or a single crystal silicon liquid crystal display (Liquid Crystal On Silicon System, LCOSSystem), etc. Devices capable of projecting displays, without limitation.

The light source module 1 includes a light source 10 , an imaging unit 11 , a spectroscopic unit 13 , a first relay unit 14 and a second relay unit 15 . The light source 10 can be, for example, a laser light source or a laser light source array (laser array). The light source 10 in this embodiment is exemplified by a laser light source, but the number and type of the light source 10 are not limited by this embodiment. The imaging unit 11 can be, for example, a digital micromirror device (Digital Micromirror Device, DMD) or a liquid crystal display device.

Please refer to FIG. 2 and FIG. 3 together. The light splitting unit 13 of this embodiment has a transmission surface 131a, a first reflection surface 132a and a second reflection surface 133a. The first reflective surface 132a and the second reflective surface 133a are arranged symmetrically, and the first reflective surface 132a and the second reflective surface 133a are respectively arranged perpendicular to the transmissive surface 131a, wherein the first reflective surface 132a and the second reflective surface 133a shield part of the transmission surface 131a, so that when light passes through the transmissive surface 131a, part of it will be reflected by the first reflective surface 132a or the second reflective surface 133a.

In detail, the light splitting unit 13 of this embodiment further includes a first sub-prism 131 , a second sub-prism 132 and a third sub-prism 133 . The first sub-prism 131 forms a transmissive surface 131 a , and the transmissive surface 131 a in this embodiment is a light-emitting surface of the first sub-prism 131 . The second sub-prism 132 and the third sub-prism 133 are arranged on the transmission surface 131a (light-emitting surface) of the first sub-prism 131, the first reflection surface 132a is arranged on the side of the second sub-prism 132 opposite to the third sub-prism 133, and the second sub-prism 132 The two reflective surfaces 133 a are disposed on a side of the third sub-prism 133 opposite to the second sub-prism 132 . That is, the first reflective surface 132a is opposite to the second reflective surface 133a. And the second sub-prism 132 can split the light transmitted to the light splitting unit 13 into two light beams.

In addition, please continue to refer to FIG. 1 , the light source module 1 of this embodiment also includes an optical scanning element 17, through which the light is transmitted to the imaging unit 11, and the optical scanning element 17 will be deflected according to different timings to form multiple Imaging differently. Furthermore, the reflective surface of the light scanning element 17 will deflect according to different timings, and image the light at different angles.

The optical scanning element 17 of this embodiment can be formed by a voice coil motor, a polygon mirror, a micro-electro-mechanical (MEMS) lens, or a combination thereof. Taking the light scanning element 17 as a voice coil motor as an example, the light scanning element 17 can have an actuating device 171 and a reflective surface 172, and the actuating device 171 can deflect the reflecting surface 172. The actuating device 171 can adjust the magnitude of the current to Adjust the deflection angle of the reflective surface 172 .

In addition, the reflective surface 172 of this embodiment can be deflected at an angle of 20 degrees to -20 degrees. If it is desired to transmit the strip light provided by the light source 10 into 16 strip light sources with different angles at different timings, the reflective The face can be deflected 2.5 degrees at a time to form 16 fields of view. However, the distribution of angles here will be adjusted according to the number of sight areas required, and is not limited to the 16 described here.

As before, please refer to FIG. 1 in particular. The light scanning element 17 can make the light provided by the light source 10 form a plurality of strip light sources on the Y-Z coordinate plane at different timings from the X-Z coordinate plane, and these strip light sources on the Y-Z coordinate plane will be Passed to the imaging unit 11.

The light source module 1 of this embodiment further includes a polarizing unit 16 , the light enters the polarizing unit 16 after leaving the imaging unit 11 , and forms parallel polarized light (P polarized light) or vertical polarized light (S polarized light). In this embodiment, the polarizing unit 16 is a parallel polarizing plate as an example, so the light leaving the polarizing unit 16 is parallel polarized light (P polarized light).

Next, refer to FIGS. 4A and 4B together, which are a perspective view and a schematic side view of the first polarizer of the first relay unit, respectively. FIG. 4B is a schematic cross-sectional view of FIG. 4A along the secant line AA. Wherein, FIG. 4B and FIG. 4A are only schematic illustrations, and the size, quantity, and shape of the components are simplified, and are not limited by this embodiment.

The first relay unit 14 of this embodiment includes a plurality of lenses 141 and a first polarizer 142 , and the plurality of lenses 141 may be convex lenses for transmitting light to the first polarizer 142 . The first polarizer 142 at least includes a plurality of strip quarter wave plates 142a, a first mirror 142b and a first black strip mask 142c. These strip-shaped quarter-wave plates 142a are arranged on the reflector 142b, and the first black strip-shaped mask 142c is arranged on a plurality of strip-shaped quarter-wave plates 142a and connected with the strip-shaped quarter-wave plates 142a. The directions in which the wave plates 142a are arranged are orthogonal. The first black strip mask 142c is a light-shielding element, which is composed of a plurality of strip-shaped black light-shielding plates, and is arranged between pixels to shield and absorb unnecessary light and improve the contrast ratio of the overall image. In actual production, a plurality of strip-shaped quarter-wave plates 142a can be pasted on one side of the substrate, and the first black strip-shaped mask 142c can be directly transferred to the other side. The first mirror 142b is disposed on the other side of the strip quarter-wave plate 142a.

The configuration of the second relay unit 15 is similar to that of the first relay unit 14, but the position of the black stripe mask configuration of the second relay unit 15 is different from the position of the black stripe mask configuration of the first relay unit 14 For example, if the black stripe masks of the first relay unit 14 are arranged in odd columns, the black stripe masks of the second relay unit 15 will be arranged in even columns, and vice versa. Except for the different positions of the black stripe mask configuration, the rest of the components and the configuration among the components are similar, so details are not described here.

4C and 4D are a perspective view and a schematic cross-sectional view of still another embodiment of the first polarizer of the first relay unit. FIG. 4D is a schematic cross-sectional view of FIG. 4C along the secant line BB.

The first polarizer 242 includes a quarter-wave plate 242a, a first mirror 242b, a second mirror matrix 242c, and a black strip mask 242d. The quarter-wave plate 242a in this embodiment is rectangular The plate shape is different from the strip-shaped quarter-wave plate 142a in the foregoing embodiment. And the second mirror matrix 242c is disposed on the quarter-wave plate 242a, and the first mirror 242b is disposed on the other side of the quarter-wave plate 242a. The black strip mask 242d is disposed on the quarter-wave plate 242a, and is aligned with the pixels of the second mirror matrix 242c (staggered arrangement). The difference from the previous embodiment is that this embodiment adopts a second mirror matrix 242c and a plate-shaped quarter-wave plate 242a to replace the strip-shaped quarter-wave plate 142a of the previous embodiment. Both the strip-shaped quarter-wave plate 142a of the foregoing embodiment and the second mirror matrix 242c of this embodiment correspond to the pixel strips of the imaging unit 11, and the configurations of both embodiments can make the first polarizer 242 The light is split into multiple arrays of parallel polarized light (P polarized light) and vertically polarized light (S polarized light). The rest of the application methods and components are similar to the foregoing embodiments and will not be repeated here.

The traveling manner of the first light beam will be described firstly below.

Part of the first light beam entering the first relay unit 14 will enter the strip quarter-wave plate 142a and be converted into vertically polarized light (S polarized light) by the first polarizer 142 and then be reflected. The part passing through the strip-shaped quarter-wave plate 142a will be reflected and then leave (the light of this part will maintain P-polarized light). Furthermore, the light rays leaving the first relay unit 14 will have different polarization directions for the odd-numbered columns and the even-numbered columns.

Then, the first relay unit 14 transmits the first light beam to the light splitting unit 13 again, and the first light beam passes through the light splitting unit 13 and leaves.

At this time, FIG. 2 and FIG. 5 can be used together. FIG. 5 is a schematic diagram of equivalent imaging of the first and second relay units, wherein the optical path is an equivalent optical path and not completely equivalent to the actual optical path. It can be clearly seen from the figure that there is a first offset d1 between the first optical axis of the first light beam and the principal axis of the light source module 1 . Furthermore, the optical axis of the first beam split by the beam splitting unit 13 is different from the main optical axis, and after passing through the first relay unit 14 , the aperture position of the first beam will be shifted.

The traveling manner of the second light beam will be described firstly below.

The second light beam entering the second relay unit 15 will also be converted by the second relay unit 15 into a situation in which the odd-numbered columns and the even-numbered columns have different polarization directions. The second light beam leaving the second relay unit 15 will then enter the light splitting unit 13 again, be reflected by the second reflective surface 133 a of the light splitting unit 13 , and leave the light splitting element 13 .

It can be clearly seen from FIG. 2 and FIG. 5 that there is a second offset d2 between the second optical axis of the second light beam and the main optical axis of the light source module 1 . Furthermore, the optical axis of the second beam split by the beam splitting unit 13 is different from the main optical axis, and after passing through the second relay unit 15 , the aperture position of the second beam will also shift. Further, the first offset d1 and the second offset d2 have opposite offset directions relative to the main optical axis.

The light source module has an aperture R, and the offsets d1 and d2 of the first optical axis and the second optical axis are a quarter of the aperture R. If the aperture R of this embodiment is 28 mm, then the first optical axis and the second optical axis will respectively deviate from the main optical axis by 7 mm. The offset between the first optical axis and the second optical axis is the same.

Please refer to FIG. 6 , which is a schematic diagram of imaging of the first and second relay units. The illustration shows two sub-apertures Z1 , Z2 arranged next to each other. The left side of Fig. 6 schematically is the imaging situation (the light has not been shifted) that the light has not yet passed through the light splitting element 13, the first relay unit 14, and the second relay unit 15, and the right side of Fig. 6 is It shows the aperture situation after the optical splitting element 13, the first relay unit 14, and the second relay unit 15 are shifted. It can be seen from the figure that through this configuration, the two sub-apertures Z1 and Z2 can be separated, so that each sub-aperture Z1 and Z2 can be imaged in the adjacent viewing area after entering the display screen, so that the light source module 10 can When the imaging area of the imaging unit 11 needs to be increased, the etendue of the light source module 10 is multiplied.

Next, please continue to refer to FIG. 7 and FIG. 8 , FIG. 7 is a schematic diagram of the projection device of the present invention. FIG. 8 is an enlarged schematic view of an angle adjusting member of the projection device in FIG. 7 .

The projection device 2 of this embodiment includes a display screen 22 and a light source module 21 .

The display screen 22 of this embodiment further includes a double-layer lenticular lens 221 having two lenticular lens layers 221a, 221b and an omnidirectional diffuser 221c sandwiched between the lenticular lens layers 221a, 221b. The light entering the double-layer lenticular lens 221 will be condensed by the lenticular lens layer 221a and imaged on the omnidirectional diffuser plate 221c, and then imaged again to the viewing plane of the user through the lenticular lens layer 221b. The magnification of the double-layer lenticular lens 221 is the ratio of the curvature radii of the lens layers 221a and 221b. That is, by adjusting the ratio of the curvature radii, the divergence angle θ of the incident light entering the double-layer lenticular lens 221 can be enlarged to a divergence angle Φ (refer to FIG. 7 ). For example, the ratio of the radius of curvature in this embodiment is 30, therefore, the enlarged divergence angle Φ is 30 times of the divergence angle θ.

It is particularly noted that, for ease of understanding, the distances, dimensions and details between the illustrated components have been exaggerated, so the illustrated dimensions should not be used as conditions to limit the present invention.

Moreover, the lenticular lens layers 221 a and 221 b here are made of transparent material with high refractive index, such as ultraviolet curing resin, thermosetting resin or plastic. And the shapes of the first lenses and the second lenses are circular, elliptical, triangular or square geometric shapes and the like.

The display screen 22 of this embodiment also includes a uniform light unit (not shown in the figure), so that the light can be uniformed to form a strip light source, and then transmitted to the viewing side. The light homogenizing unit in this embodiment can be, for example, an integration rod or a light tunnel, but it is not limited thereto.

The display screen 22 of this embodiment also includes a collimation unit 222 disposed between the double-layer lenticular lens 221 and the light source module 21 , the collimation unit 222 can collimate incoming light and enter the double-layer lenticular lens 221 in parallel. In addition, the collimation unit 222 in this embodiment is a linear Fresnel lens as an example.

The angle adjusting member 224 is made of birefringent material, and the angle adjusting member 224 has a plurality of refraction surfaces 224a. For example, after cutting a plurality of jagged microstructures on the surface of a plastic substrate, a birefringent material can be filled in the microstructures to form the angle modifying member 224 as shown in FIG. 8 . And the vertically polarized light (S polarized light) passing through the refracting surface 224a will be refracted, and if the incoming light is parallel polarized light (P polarized light), it will directly pass through the refracting surface 224a (without deflection) . Through this design, the outgoing angle of the light entering and leaving the angle modifying member 224 will be increased by another outgoing angle (relative to its incident angle).

Further, if the incident angle of light provided by the light source module 21 is θ, the incident angle of the light can be increased to θ′ through the angle adjusting member 224, and the incident angle received by the double-layer lenticular lens 221 will not be θ but θ', the divergence angle Φ of the final image on the viewing side will also increase. With such a screen design, the etendue can be increased by disposing the angle modifying member 224 on the display screen 22 without adjusting the design of the light source module 21 .

However, the light source module 21 of this embodiment can also adopt the aforementioned light source module, but is not limited to the aforementioned light source module. If the above-mentioned light source module is used, the etendue can be multiplied in the light source module, and then the etendue can be multiplied again through the angle adjusting member 224 on the side of the display screen 22. Therefore, the imaging area of the imaging unit can be increased without increasing the etendue. In this case, the etendue of the projection device is quadrupled. The detailed structure and application method of the aforementioned light source module 21 will not be described again.

Next, please refer to FIG. 9 , which is an enlarged schematic view of another embodiment of the angle-adjusting member of the projection device shown in FIG. 7 .

Please refer to FIG. 9 first. Compared with the angle modifying member 224 in FIG. 8 , the angle modifying member 324 of this embodiment includes a sawtooth prism 324 a , a strip half-wave plate 324 b and a polarizer 324 c. And the polarizer 324c allows the parallel polarized light (P polarized light) to pass through.

The light entering the angle modulating element 324 includes parallel polarized light (P polarized light) and vertical polarized light (S polarized light). The sawtooth prism 324a includes a plurality of refraction surfaces, and adjacent refraction surfaces have different angles. The positions of the saw-tooth prism 324a and the strip half-wave plate 324b are aligned. Further, the refraction surfaces of the saw-tooth prism 324a are set corresponding to each of the strip half-wave plates 324b. Part of the light that passes through the serrated prism 324a and enters the strip half-wave plate 324b, the vertically polarized light (S polarized light) will be converted into parallel polarized light (P polarized light), parallel polarized light (P polarized light) polarized light) will be converted to vertically polarized light (S polarized light). Conversely, part of the light passing through the sawtooth prism 324a but not entering the strip half-wave plate 324b will maintain the original vertically polarized light (S polarized light) and parallel polarized light (P polarized light). Then the polarizer 324c will block the vertically polarized light (S polarized light), so the light leaving the angle modulating element 324 is all parallel polarized light (P polarized light). However, through the sawtooth prism 324a, one outgoing angle of the incident light leaving the angle modifying member 324 will be changed into two outgoing angles (relative to its incident angle). Parallel-polarized incident light is turned to a forward angle, and perpendicularly polarized incident light is turned to another reverse angle

Here, the technical effect of setting the angle adjusting member 324 and its collocation with other components are similar to those of the foregoing embodiments, so details will not be repeated here.

To sum up, the light source module provided by this embodiment can split the light into the first light beam and the second light beam by setting the first reflective surface on the transmission surface of the light splitting unit, and the first light beam and the second light beam Will enter the first relay unit and the second relay unit respectively. The optical axes of the first light beam and the second light beam entering the first relay unit and the second relay unit will have an offset relative to the main optical axis. Therefore, the number of resolvable light angles leaving the light source module can be increased (the etendue is increased), and the purpose of increasing the number of resolvable viewing areas can be achieved without changing or increasing the imaging unit.

The above descriptions are illustrative only, not restrictive. Any equivalent modifications or changes made without departing from the spirit and scope of the present invention shall be included in the claims.

Claims (21)

1. A light source module for a display device, and the light source module has a main optical axis, characterized in that the light source module comprises: a light source, providing a light; an imaging unit; A light splitting unit having a transmission surface, a first reflection surface and a second reflection surface, and the first reflection surface and the second reflection surface are arranged symmetrically; a first relay unit; and a second relay unit, Wherein, the light passes through the imaging unit and the spectroscopic unit in sequence, part of the light forms a first light beam, and part of the light forms a second light beam, and the first light beam is reflected by the first reflective surface and enters the first relay unit, the first relay unit transmits the first light beam to the light splitting unit, and the first light beam passes through the light splitting unit and leaves; Wherein, the second light beam passes through the light splitting unit and enters the second relay unit, and the second relay unit transmits the second light beam to the second reflection surface of the light splitting unit, and the second light beam is received by the second light beam Reflected by two reflective surfaces, and leave the light splitting unit, There is a first offset between a first optical axis of the first light beam and the main optical axis, a second offset between a second optical axis of the second light beam and the main optical axis, the The first offset is the same as the second offset, and the direction of the first offset and the second offset is opposite to the main optical axis, Wherein the first relay unit includes a first polarizer, the first polarizer includes a black strip mask, a quarter-wave plate and a mirror, the quarter-wave plate is arranged on On the reflecting mirror, the black strip mask is arranged on the quarter-wave plate. 2. The light source module according to claim 1, wherein the light source module has an aperture, and the offset between the first optical axis and the second optical axis is a quarter of an aperture. 3. The light source module as claimed in claim 1, wherein the imaging unit is a digital micromirror device or a liquid crystal display device. 4. The light source module as claimed in claim 1, wherein the light source is a laser light source or a laser light source array. 5. The light source module according to claim 1, further comprising a polarizing unit, wherein the light enters the polarizing unit after exiting the imaging unit, and forms a parallel polarized light or a vertical polarized light. 6. The light source module according to claim 1, wherein the quarter-wave plate is strip-shaped, and the black strip-shaped mask is perpendicular to the direction in which the strip-shaped quarter-wave plate is arranged. 7. The light source module according to claim 1, further comprising an optical scanning element, wherein the light is transmitted to the imaging unit through the optical scanning element, and the optical scanning element makes a reflective surface of the optical scanning element deflection to form multiple different images. 8. The light source module as claimed in claim 7, wherein the light scanning element is a voice coil motor, a polygon mirror or a micro-electromechanical mirror. 9. The light source module according to claim 1, wherein the light splitting unit further comprises a first sub-prism, a second sub-prism and a third sub-prism, the first sub-prism forms the transmission surface, the second sub-prism The prism and the third sub-prism are arranged on the transmission surface of the first sub-prism, the first reflection surface is arranged on the side of the second sub-prism opposite to the third sub-prism, and the second reflection surface is arranged on the first sub-prism. One side of the three sub-prisms opposite to the second sub-prisms. 10. A display device, characterized in that it comprises: a display screen; and A light source module has a main optical axis, and the light source module includes: a light source, providing a light; an imaging unit; A light splitting unit having a transmission surface, a first reflection surface and a second reflection surface, and the first reflection surface and the second reflection surface are arranged symmetrically; a first relay unit; and a second relay unit; Wherein, the light passes through the imaging unit and the spectroscopic unit in sequence, part of the light forms a first light beam, and part of the light forms a second light beam, and the first light beam is reflected by the first reflective surface and enters the first relay unit, the first relay unit transmits the first light beam to the light splitting unit; Wherein, the second light beam passes through the light splitting unit and enters the second relay unit, and the second relay unit transmits the second light beam to the second reflection surface of the light splitting unit, and the second light beam is received by the second light beam Reflected by the two reflective surfaces and transmitted to the spectroscopic unit, There is a first offset between a first optical axis of the first light beam and the main optical axis, a second offset between a second optical axis of the second light beam and the main optical axis, the The first offset is the same as the second offset, the first light beam and the second light beam are transmitted to the display screen by the light splitting unit, Wherein the first relay unit of the light source module includes a first polarizer, and the first polarizer includes a black strip mask, a quarter wave plate and a reflector, and the quarter The wave plate is set on the reflector, and the black stripe mask is set on the quarter wave plate. 11. The display device according to claim 10, wherein the light source module has an aperture, and the offset between the first optical axis and the second optical axis is a quarter of an aperture. 12. The display device as claimed in claim 10, wherein the imaging unit is a digital micromirror device or a liquid crystal display device. 13. The display device as claimed in claim 10, wherein the light source is a laser light source or a laser light source array. 14. The display device according to claim 10, wherein the light source module further comprises a polarizing unit, wherein the light enters the polarizing unit after leaving the imaging unit, and forms a parallel polarized light or a vertical polarized light . 15. The display device according to claim 10, wherein the quarter-wave plate is strip-shaped, and the black strip-shaped mask is perpendicular to a direction in which the strip-shaped quarter-wave plate is arranged. 16. The display device according to claim 10, wherein the light source module further comprises a light scanning element, wherein the light is transmitted to the imaging unit through the light scanning element, and the light scanning element is deflected according to different timings to form multiple different images. 17. The display device as claimed in claim 16, wherein the optical scanning element is a voice coil motor, a polygon mirror or a micro-electromechanical mirror. 18. The display device according to claim 10, wherein the light splitting unit further comprises a first sub-prism, a second sub-prism and a third sub-prism, the first sub-prism forms the transmission surface, and the second sub-prism The prism and the third sub-prism are arranged on the transmission surface of the first sub-prism, the first reflection surface is arranged on the side of the second sub-prism opposite to the third sub-prism, and the second reflection surface is arranged on the first sub-prism. One side of the three sub-prisms opposite to the second sub-prisms. 19. The display device as claimed in claim 10, wherein the display screen comprises a double-layer lenticular lens having two lenticular lens layers and an omnidirectional diffuser sandwiched between the lenticular lens layers. 20. The display device as claimed in claim 10, further comprising an angle modulating element, wherein the angle modulating element comprises a plurality of refraction surfaces made of birefringent material. 21. The display device according to claim 10, further comprising an angle modulating member, wherein the angle modulating member comprises a polarizer, a plurality of strip half-wave plates and a sawtooth prism, and the sawtooth prism includes multiple each of the refraction surfaces corresponds to each of the strip half-wave plates.