TWI805417B - Illuminatiion system and projeciton device - Google Patents

Abstract

An illumination system including a light source module, a first lens array, a condensing element, a second lens array and a prism element is provided. The light source module is adapted to providing an illumination beam. The first lens array is arranged on the transmission path of the illumination beam. The condensing element is arranged on the transmission path of the illumination beam. The first lens array is located between the light source module and the condensing element. The second lens array is arranged on the transmission path of the illumination beam. The prism element is arranged on the transmission path of the illumination beam. The second lens array is located between the condensing element and the prism element, wherein the area of the second lens array is larger than the area of the first lens array.

Description

Lighting system and projection device

The present invention relates to an optical system and a display device, and in particular to an illumination system and a projection device with the illumination system.

The projection device is a display device used to generate a large-area image, and has been continuously improving with the evolution and innovation of technology. The imaging principle of the projection device is to convert the illumination beam generated by the lighting system into an image beam through the light valve, and then project the image beam to the projection target (such as a screen or wall) through the projection lens to form a projection image.

In order to pursue a smaller projection device and apply it to a micro projection device, it can be used on a head-mounted display. The lighting system of the micro projection device has changed from the early R / G / B three channels (Red/Green/Blue LED light beams forming three pathways), and gradually evolved to the current RB / G two channels (Red and Blue/Green LED light beams forming two pathways), or RGB one channel (Red and Blue and Green LED light beams forming one pathway). The above-mentioned three structures all use collimating lens to make the light source provided by light-emitting diodes incident to the lens array in parallel, and then focus the light beam on the lens array on the imaging element of the light valve through the condenser lens. However, in order to achieve the smallest volume design, the least number of light sources will be used for the design. However, because part of the color light sources are one light source each, and the positions are diagonal to each other, the projected picture will have obvious color unevenness.

The "Prior Art" paragraph is only used to help understand the content of the present invention, so the content disclosed in the "Prior Art" paragraph may contain some conventional technologies that do not constitute the knowledge of those with ordinary skill in the art. The content disclosed in the "Prior Art" paragraph does not mean that the content or the problems to be solved by one or more embodiments of the present invention have been known or recognized by those with ordinary knowledge in the technical field before the application of the present invention.

The invention provides an illumination system and a projection device, which can improve the uniformity of the illumination beam and the uniformity of different colors.

Other purposes and advantages of the present invention can be further understood from the technical features disclosed in the present invention.

In order to achieve one or part or all of the above objectives or other objectives, the present invention provides an illumination system, including a light source module, a first lens array, a light concentrating element, a second lens array, and an optical element. The light source module is used for providing illumination beams. The first lens array is arranged on the transmission path of the illumination light beam. The light collecting element is arranged on the transmission path of the illumination beam. The first lens array is located between the light source module and the light concentrating element. The second lens array is arranged on the transmission path of the illumination light beam. The 稜鏡 element is arranged on the transmission path of the illumination light beam. The second lens array is located between the light concentrating element and the narrowing element, wherein the surface area of the second lens array is greater than that of the first lens array.

In one embodiment, the second lens array includes a plurality of micro-lenses located on opposite sides of the second lens array.

In one embodiment, the second lens array includes a plurality of microlenses, and the plurality of microlenses are arranged in a hexagonal arrangement, a rectangular arrangement or a helical arrangement.

In one embodiment, the extension direction of the second lens array has an included angle with the extension direction of the light-emitting surface of the micron element.

In one embodiment, the light source module includes a light emitting element and a collimating lens group, wherein the light emitting element provides red light, green light and blue light.

In one embodiment, the light emitting element is arranged by red, green, green and blue light emitting diodes.

In one embodiment, the collimating lens group includes at least one optical lens.

In one embodiment, the collimating lens set includes a compound parabolic concentrator.

In one embodiment, the first lens array is directly connected to the compound parabolic concentrator.

In one embodiment, the light concentrating element has a reflective surface for reflecting the illuminating light beam to pass to the second lens array.

To achieve one or part or all of the above objectives or other objectives, the present invention further provides a projection device, including an illumination system, a light valve, and a projection lens. The lighting system is used to provide the lighting beam. The lighting system includes a light source module, a first lens array, a light-condensing element, a second lens array, and a lens element. The light source module is used for providing illumination beams. The first lens array is arranged on the transmission path of the illumination light beam. The light collecting element is arranged on the transmission path of the illumination beam. The first lens array is located between the light source module and the light concentrating element. The second lens array is arranged on the transmission path of the illumination light beam. The 稜鏡 element is arranged on the transmission path of the illumination light beam. The second lens array is located between the light concentrating element and the narrowing element. The light valve is arranged on the transmission path of the illuminating light beam, and is used for converting the illuminating light beam into an image light beam. The projection lens is arranged on the transmission path of the image beam for projecting the image beam out of the projection device, wherein the surface area of the second lens array is larger than that of the first lens array.

Based on the above, the embodiments of the present invention have at least one of the following advantages or functions. In the lighting system and the projection device of the present invention, the lighting system includes a light source module, a first lens array, a light concentrating element, a second lens array, and a lens element. Wherein the first lens array is arranged between the light source module and the condensing element, and is used to control the beam sectional area size of the illumination beam provided by the light source module to match the surface size (surface area) of the light valve receiving the illumination beam, and the second The lens array is arranged between the light-condensing element and the light-emitting element, and is used for changing and uniformizing the light pattern of each color in the illumination beam. In this way, the uniformity of the illumination beam and the uniformity of different colors can be improved, so as to avoid the phenomenon that the color light emitted by the light-emitting element is not uniform.

In order to make the above-mentioned features and advantages of the present invention more comprehensible, the following specific embodiments are described in detail together with the accompanying drawings.

The aforementioned and other technical contents, features and effects of the present invention will be clearly presented in the following detailed description of a preferred embodiment with reference to the drawings. The directional terms mentioned in the following embodiments, such as: up, down, left, right, front or back, etc., are only directions referring to the attached drawings. Accordingly, the directional terms used are for the purpose of illustration and not for the purpose of limiting the invention.

FIG. 1 is a schematic diagram of a projection device according to an embodiment of the present invention. Please refer to Figure 1. In one embodiment, the projection device 10 can be applied to a head-mounted display. This embodiment provides a projection device 10 including an illumination system 100 , a light valve 60 and a projection lens 70 . Wherein, the illumination system 100 is used for providing an illumination beam LB. The light valve 60 is disposed on the transmission path of the illumination beam LB for converting the illumination beam LB into the image beam LI. The projection lens 70 is disposed on the transmission path of the image beam LI, and is used to project the image beam LI out of the projection device 10 to a projection target (not shown), such as a screen, a wall or a waveguide element of a head-mounted device.

In this embodiment, the light valve 60 is, for example, a reflective light modulator such as a Liquid Crystal On Silicon panel (LCoS panel) or a digital micromirror device (Digital Micro-mirror Device, DMD). The present invention does not limit the type and type of the light valve 60 . The detailed steps and implementation of the method for the light valve 60 to convert the illumination beam LB from the illumination system 100 into the image beam LI can be obtained from the general knowledge in the technical field for sufficient teaching, suggestion and implementation description, and thus will not be repeated here. In this embodiment, the number of the light valve 60 is one, for example, the projection device 10 using a single DMD. The light valve 60 can also use a liquid crystal silicon on board. In this embodiment, the projection device 10 further includes a protective cover 80 (see FIG. 2 ), which is used to prevent the light valve 60 from contacting dust and affecting the optical effect. The material of the protective cover 80 is, for example, glass or plastic.

The projection lens 70 includes, for example, a combination of one or more optical lenses with diopters, such as various combinations of non-planar lenses such as biconcave lenses, biconvex lenses, concave-convex lenses, convex-concave lenses, plano-convex lenses, and plano-concave lenses. In an embodiment, the projection lens 70 may also include a flat optical lens to project the image light beam LI from the light valve 60 to the projection target in a reflective manner. The present invention does not limit the type and type of the projection lens 70 .

FIG. 2 is a schematic diagram of an illumination system according to an embodiment of the present invention. FIG. 3 is a schematic diagram of a light source module according to an embodiment of the present invention. Please refer to Figure 2 and Figure 3. The lighting system 100 of this embodiment can be applied to at least the projection device 10 shown in FIG. 1 , so the following description takes this as an example. In this embodiment, the lighting system 100 includes a light source module 110 , a first lens array 120 , a light concentrating element 130 , a second lens array 140 , and a lens element 150 . The light source module 110 is used for providing an illumination beam LB. In this embodiment, the light source module 110 includes a light emitting element 112 and a collimating lens group 114 , wherein the light emitting element 112 is, for example, an integrated light emitting diode, which provides red light, green light and blue light. Specifically, the light-emitting element 112 is arranged by red, green, green and blue light-emitting diodes, and the red and blue light-emitting diodes are diagonal to each other, and the two green light-emitting diodes are diagonal to each other. , as shown in Figure 3. Therefore, it is possible to achieve a minimum volume design, but the present invention is not limited thereto. In this embodiment, the collimating lens group 114 includes at least one optical lens, and the collimating lens group 114 is used to provide parallel illumination beams LB to the first lens array 120 , and the invention is not limited thereto.

The first lens array 120 is arranged on the transmission path of the illumination beam LB, and is used to control the beam cross-sectional area size of the illumination beam LB provided by the light source module 110 to match the surface size (surface area) of the light valve 60 receiving the illumination beam LB. . For example, the beam cross-sectional size of the illumination beam LB passing through the first lens array 120 is equal to or approximate to the surface size of the light valve 60 receiving the illumination beam LB.

The first lens array 120 includes a plurality of microlenses, which may be located on a single surface of the first lens array 120 or on two opposite surfaces of the first lens array 120 , the present invention is not limited thereto.

The light concentrating element 130 is disposed on the transmission path of the illumination beam LB, and the first lens array 120 is located between the light source module 110 and the light concentrating element 130 . In this embodiment, the light concentrating element 130 has a reflective surface 132 , for example coated with a reflective film, for reflecting the illumination light beam LB to transmit to the second lens array 140 .

The second lens array 140 is arranged on the transmission path of the illumination beam LB, and is used to change the light pattern of each color (red, green, and blue) in the illumination beam LB and make it uniform, thereby improving the uniformity and the difference of the illumination beam LB. The uniformity of the color can avoid the phenomenon that the color light emitted by the light emitting element 112 is not uniform. The second lens array 140 includes a plurality of micro lenses located on two opposite surfaces of the second lens array 140 . In this embodiment, physically, the surface area of the second lens array 140 is larger than that of the first lens array 120 . In addition, the beam area of the light incident surface of the second lens array 140 receiving the illumination beam LB is larger than the beam area of the light incident surface of the first lens array 120 receiving the illumination beam LB.

4A to 4C are schematic diagrams of partial lens arrays in different embodiments. Please refer to FIG. 2, FIG. 4A to FIG. 4C. In different embodiments, the micro-lenses M of the first lens array 120 and the second lens array 140 may have different arrangement designs according to different situations. For example, as shown in FIG. 4A , the microlenses M of the first lens array 120 and the second lens array 140 may be arranged in a hexagonal manner (or called a circular arrangement). Alternatively, as shown in FIG. 4B , the microlenses M1 of the first lens array 120 and the second lens array 140 may be arranged in a rectangle. Alternatively, as shown in FIG. 4C , the microlenses M2 of the first lens array 120 and the second lens array 140 may be arranged in a spiral (for convenience, FIG. 4C only shows the arrangement positions), but the present invention is not limited thereto.

FIG. 5 is a partially enlarged schematic view of the lighting system in FIG. 2 . Please refer to Figure 2 and Figure 5. The light-emitting element 150 is disposed on the transmission path of the illumination beam LB, and the second lens array 140 is located between the light-condensing element 130 and the light-emitting element 150 . The prism element 150 is, for example, a total internal reflection prism (TIR prism) for guiding the illumination beam LB to the light valve 60 and guiding the image beam LI to the projection lens 70 (as shown in FIG. 1 ). To further illustrate, the light-emitting element 150 has a first surface and a light-emitting surface, the first surface of the light-emitting element 150 faces the second lens array 140 , and the light-emitting surface of the light-emitting element 150 faces the light valve 60 . The first surface of the luminous element 150 is used for receiving the illumination beam LB, which enters the luminous element 150 and is transmitted to the light valve 60 . When the light valve 60 converts the illumination light beam LB into the image light beam LI, the image light beam LI enters the light beam element 150 again, and the image light beam LI is reflected by the first surface of the light beam element 150 to leave the light beam element 150 and pass to the projection lens 70.

In addition, in this embodiment, the extension direction of the second lens array 140 (this extension direction is perpendicular to the normal direction of the surface of the second lens array 140) and the extension direction of the light-emitting surface of the galvanized element 150 (this extension direction is perpendicular to There is an included angle A in the normal direction of the surface of the light valve 60 ). The light emitting surface of the light emitting element 150 is parallel to the surface of the light valve 60 . Specifically, the lighting system 100 may further include a spacer 160 , and there is a distance between the spacer 160 and the second lens array 140 .

The spacer 160 is disposed between the second lens array 140 and the lens element 150 , and its purpose is to prevent the illuminating light beam LB from producing an optical path difference in the air layer, thereby degrading the quality of the projected image. It is worth mentioning that, in this embodiment, the size (ie, the optical area) of the second lens array 140 can be determined according to the surface size of the light valve 60 and its light-receiving angle. In this way, the use efficiency of light can be improved, as shown in FIG. 5 , thereby improving the uniformity of the illumination beam LB.

Fig. 6 is a schematic diagram of an illumination system according to another embodiment of the present invention. Please refer to Figure 6. The lighting system 100A of this embodiment is similar to the lighting system 100 shown in FIG. 2 . The difference between the two is that, in this embodiment, the collimating lens group 114A of the light source module 110A includes a compound parabolic concentrator (Compound Parabolic Concentrator, CPC), which is used to transmit the light emitted by the light emitting element 112 at different angles. The curved surface of the compound parabolic concentrator becomes parallel light. Furthermore, the first lens array 120A is directly connected to the compound parabolic concentrator. Therefore, the volume of the lighting system 100A can be further saved, and it has good optical effect. In another embodiment, the first lens array 120A may also be directly configured and connected to the light incident surface of the light concentrating element 130 . In this way, the uniformity of the illumination light beam and the uniformity of different colors can be improved, so as to avoid the phenomenon that the color light emitted by the light emitting element 112 is not uniform.

To sum up, in the lighting system and the projection device of the present invention, the lighting system includes a light source module, a first lens array, a light-condensing element, a second lens array, and a light-emitting element. Wherein the first lens array is arranged between the light source module and the condensing element, and is used to control the beam cross-sectional area size of the illumination beam provided by the light source module to match the surface area size of the light valve receiving the illumination beam, and the second lens array is configured Between the light-condensing element and the light-emitting element, it is used to change and uniformize the light pattern of each color in the illumination beam, and the surface area of the second lens array is larger than that of the first lens array. In this way, the uniformity of the illumination beam and the uniformity of different colors can be improved, so as to avoid the phenomenon that the color light emitted by the light-emitting element is not uniform.

But the above-mentioned ones are only preferred embodiments of the present invention, and the scope of implementation of the present invention cannot be limited with this, that is, all simple equivalent changes and modifications made according to the patent scope of the present invention and the contents of the description of the invention, All still belong to the scope covered by the patent of the present invention. In addition, any embodiment or scope of claims of the present invention does not need to achieve all the objectives or advantages or features disclosed in the present invention. In addition, the abstract and the title are only used to assist the search of patent documents, and are not used to limit the scope of rights of the present invention. In addition, terms such as "first" and "second" mentioned in this specification or the scope of the patent application are only used to name elements (elements) or to distinguish different embodiments or ranges, and are not used to limit the number of elements. upper or lower limit.

10: Projection device 60: light valve 70:Projection lens 80: Protective cover 100,100A: lighting system 110,110A: light source module 112: Light emitting element 114, 114A: Collimating lens group 120, 120A: the first lens array 130: Concentrating element 132: reflective surface 140: the second lens array 150: 騜鏡 Components 160: spacer A: Angle LB: lighting beam LI: image beam M, M1, M2: microlenses.

FIG. 1 is a schematic diagram of a projection device according to an embodiment of the present invention. FIG. 2 is a schematic diagram of an illumination system according to an embodiment of the present invention. FIG. 3 is a schematic diagram of a light source module according to an embodiment of the present invention. 4A to 4C are schematic diagrams of partial lens arrays in different embodiments. FIG. 5 is a partially enlarged schematic view of the lighting system in FIG. 2 . Fig. 6 is a schematic diagram of an illumination system according to another embodiment of the present invention.

60: light valve

100: Lighting system

110:Light source module

112: Light emitting element

114: Collimating lens group

120: the first lens array

130: Concentrating element

132: reflective surface

140: the second lens array

150: 騜鏡 Components

160: spacer

A: Angle

LB: lighting beam

Claims (20)

An illumination system, comprising: a light source module, used to provide an illumination beam; a first lens array, arranged on the transmission path of the illumination beam; a concentrating element, arranged on the transmission path of the illumination beam, and the first A lens array is located between the light source module and the light concentrating element; a second lens array is arranged on the transmission path of the illumination light beam from the light concentrating element; On the transmission path of the illuminating light beam of the second lens array, the second lens array is located between the light concentrating element and the light-emitting element, wherein the surface area of the second lens array is larger than that of the first lens array The surface area of a lens array. The illumination system as claimed in claim 1, wherein the second lens array includes a plurality of microlenses located on opposite sides of the second lens array. The lighting system according to claim 1, wherein the second lens array includes a plurality of microlenses, and the plurality of microlenses are arranged in a hexagonal arrangement, a rectangular arrangement or a helical arrangement. The lighting system according to claim 1, wherein the extending direction of the second lens array has an included angle with the extending direction of the light-emitting surface of the 稜鏡 element. The lighting system according to claim 1, wherein the light source module includes a light emitting element and a collimating lens group, wherein the light emitting element provides red light, green light and blue light. The lighting system according to claim 5, wherein the light-emitting elements are arranged by red, green, green and blue light-emitting diodes. The illumination system as claimed in claim 5, wherein the collimating lens group comprises at least one optical lens. The illumination system as claimed in claim 5, wherein said collimating lens group comprises a compound parabolic concentrator. The illumination system of claim 8, wherein said first lens array is directly connected to said compound parabolic concentrator. The illumination system as claimed in claim 1, wherein the light concentrating element has a reflective surface for reflecting the illumination light beam to be delivered to the second lens array. A projection device, comprising: an illumination system for providing an illumination beam, the illumination system comprising: a light source module, for providing an illumination beam; a first lens array, configured on the transmission path of the illumination beam; a light concentrating element , arranged on the transmission path of the illumination light beam, the first lens array is located between the light source module and the light concentrating element; the second lens array is arranged on the illumination from the light concentrating element On the transmission path of the light beam; and the 稜鏡 element, configured on the transmission path of the illumination light beam from the second lens array, the second lens array is located between the light concentrating element and the 稜鏡 element ; The light valve is configured on the transmission path of the illumination light beam, and is used to direct the illumination converting the light beam into an image light beam; and a projection lens, configured on the transmission path of the image light beam, for projecting the image light beam out of the projection device, wherein the surface area of the second lens array is larger than that of the first lens array The surface area of the lens array. The projection device as claimed in claim 11, wherein the second lens array includes a plurality of microlenses, and are located on opposite sides of the second lens array. The projection device according to claim 11, wherein the second lens array includes a plurality of microlenses, and the plurality of microlenses are in a hexagonal arrangement, a rectangular arrangement or a helical arrangement. The projection device according to claim 11, wherein the extending direction of the second lens array has an included angle with the extending direction of the light-emitting surface of the galvanized element. The projection device according to claim 11, wherein the light source module includes a light emitting element and a collimating lens group, wherein the light emitting element provides red light, green light and blue light. The projection device according to claim 15, wherein the light-emitting elements are red, green, green, and blue light-emitting diodes arranged in an arrangement. The projection device as claimed in claim 15, wherein the collimating lens group includes at least one optical lens. The projection device according to claim 15, wherein the collimating lens group comprises a compound parabolic concentrator. The projection device of claim 18, wherein the first lens array is directly connected to the compound parabolic concentrator. The projection device as claimed in claim 11, wherein the light concentrating element has a reflective surface for reflecting the illumination light beam to be delivered to the second lens array.

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