Illumination system and projection device

Abstract

The invention provides an illumination system for generating an illumination light beam and a projection device. The illumination system comprises an excitation light source, a light guide module, a collimating lens group and a wavelength conversion element. The excitation light source emits an excitation beam. The light guide module, the collimating lens group and the wavelength conversion element are arranged on a transmission path of the excitation light beam. After being emitted from the excitation light source, excitation light beams are sequentially reflected by the light guide module, penetrate through the collimating lens group and then are transmitted to the wavelength conversion element. One part of the excitation light beam is sequentially reflected by the wavelength conversion element, penetrates through the collimating lens group and then penetrates through the light guide module, and the other part of the excitation light beam is converted into a conversion light beam by the wavelength conversion element. The conversion light beam penetrates through the collimating lens group and then penetrates through the light guide module. The part of the excitation light beam emitted from the light guide module and the conversion light beam form an illumination light beam.

Description

Technical Field

[0001] The present invention relates to the field of optical systems and optical devices, and in particular to an illumination system and a projection device. Background Art

[0002] Generally speaking, the illumination system used in a projection device is composed of light source module, focusing collimation module, light homogenization element, light guide module, etc. Among them, the illumination beam generated by the illumination system is converted into an image beam by the light valve, and the image beam is projected out of the projection device through the projection lens.

[0003] Currently, common lighting systems are large in size, contain many optical components, have complex optical paths, and have high system costs. When the use environment requires the lighting device to be smaller, such as automotive lighting, in addition to the need to reduce the size, the lighting system must also comply with regulatory requirements such as color temperature and brightness.

[0004] Therefore, it is necessary to design a novel lighting system and projection device to overcome the above-mentioned defects. Summary of the invention

[0005] The object of the present invention is to provide an illumination system and a projection device, which are small in size, reduce optical elements, effectively simplify the optical path design, and improve the efficiency of light energy use.

[0006] To achieve the above-mentioned object, the present invention provides an illumination system and a projection device. The illumination system is used to generate an illumination beam, comprising:

[0007] an excitation light source for emitting an excitation light beam;

[0008] A light guide module, arranged on the transmission path of the excitation light beam;

[0009] A collimating lens group is arranged on the transmission path of the excitation light beam; and

[0010] The wavelength conversion element is arranged on the transmission path of the excitation light beam.

[0011] After being emitted from the excitation light source, the excitation light beam is sequentially reflected by the light guide module, penetrates the collimating lens group, and then is transmitted to the wavelength conversion element. A portion of the excitation light beam is sequentially reflected by the wavelength conversion element, penetrates the collimating lens group, and then penetrates the light guide module. Another portion of the excitation light beam is converted by the wavelength conversion element into a conversion light beam, which penetrates the collimating lens group and then penetrates the light guide module.

[0012] The portion of the excitation light beam emitted from the light guide module and the conversion light beam form the illumination light beam.

[0013] Preferably, the light guide module has a total internal reflection surface, wherein the excitation light beam emitted from the excitation light source is incident on the total internal reflection surface at a first angle, and the portion of the excitation light beam or the converted light beam is incident on the total internal reflection surface at a second angle, the first angle is greater than the critical angle of the total internal reflection surface, and the second angle is less than the critical angle of the total internal reflection surface.

[0014] Preferably, the light guide module includes a first prism and a second prism, the first prism is arranged between the second prism and the collimating lens group, wherein the interface between the first prism and the second prism adjacent to the total internal reflection surface.

[0015] Preferably, there is a gap between the first prism and the second prism, and the critical angle is determined by the material of the lighting system at the gap and the material of the first prism.

[0016] Preferably, it also includes:

[0017] The anti-reflection film is disposed on the interface where the first prism is adjacent to the second prism and / or disposed on the interface where the second prism is adjacent to the first prism.

[0018] Preferably, the wavelength conversion element includes a wavelength conversion area and a non-wavelength conversion area, the portion of the excitation beam is incident on the non-wavelength conversion area, and the other portion of the excitation beam is incident on the wavelength conversion area, and the excitation beam is converted into the conversion beam by the wavelength conversion area.

[0019] Preferably, the wavelength conversion element is a stationary part or a rotatable part.

[0020] Preferably, it also includes:

[0021] The projection lens is arranged on the transmission path of the illumination light beam and is used for projecting the illumination light beam out of the illumination system.

[0022] Preferably, a projection device for generating an image beam comprises:

[0023] A lighting system for providing a lighting beam, the lighting system being the aforementioned lighting system;

[0024] a light valve disposed on a transmission path of the illumination light beam, for converting the illumination light beam into the image light beam; and

[0025] The projection lens is arranged on the transmission path of the image light beam and is used for projecting the image light beam out of the projection device.

[0026] Preferably, the light valve is a transmissive liquid crystal panel, and the light valve is disposed between the projection lens and the light guide module.

[0027] Preferably, a curved reflector is disposed on the transmission path of the illumination light beam to transmit the illumination light beam from the light guide module to the light valve.

[0028] Preferably, the light valve is a digital micromirror element, and the curved reflector is disposed between the projection lens and the light valve.

[0029] Compared with the prior art, the lighting system provided by the present invention is composed of an excitation light source, a light guide module, a collimating lens group and a wavelength conversion element, and the excitation light beam emitted by the excitation light source is guided to the wavelength conversion element in a (total) reflection manner. Therefore, the lighting system reduces the number of optical elements in the optical path and simplifies the optical path design, which can reduce the loss of light energy and thus improve the efficiency of light energy use. At the same time, the system cost can be reduced and the system volume can be reduced. Furthermore, the lighting light beam includes a combination of different color light beams such as a part of the excitation light beam and the conversion light beam, which is conducive to improving the color performance and uniformity performance of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a schematic diagram of a lighting system according to a first embodiment of the present invention;

[0031] Figure 2 for Figure 1 A schematic diagram of a wavelength conversion element in FIG.

[0032] Figure 3 is a schematic diagram of a lighting system according to a second embodiment of the present invention;

[0033] Figure 4 is a schematic diagram of a projection device according to a first embodiment of the present invention;

[0034] Figure 5 FIG. 4 is a schematic diagram of a projection device according to a second embodiment of the present invention. DETAILED DESCRIPTION

[0035] In order to provide a further understanding of the purpose, structure, features, and functions of the present invention, the following detailed description is given in conjunction with the embodiments.

[0036] Certain words are used in the specification and claims to refer to specific components. Those with ordinary knowledge in the field should understand that manufacturers may use different terms to refer to the same component. This specification and claims do not use differences in names as a way to distinguish components, but rather use differences in components' functions as the criteria for distinction. The term "including" mentioned throughout the specification and claims is an open-ended term and should be interpreted as "including but not limited to".

[0037] Figure 1 is a schematic diagram of a lighting system according to a first embodiment of the present invention. Figure 1An embodiment of the present invention provides an illumination system 100 for generating an illumination light beam IL. The illumination system 100 includes an excitation light source 110, a light guide module 120, a collimating lens group 130, and a wavelength conversion element 140.

[0038] In this embodiment, the excitation light source 110 is used to emit an excitation light beam L. The excitation light source 110 is, for example, a light-emitting diode (LED), a laser diode (LD) or other suitable light sources.

[0039] In this embodiment, the collimating lens set 130 includes, for example, a combination of one or more optical lenses having a refractive power. The present invention does not limit the type and form of the collimating lens set 130 .

[0040] In the present embodiment, the light guide module 120, the collimating lens group 130 and the wavelength conversion element 140 are arranged on the transmission path of the excitation light beam L. After being emitted from the excitation light source 110, the excitation light beam L is sequentially (after entering the light guide module 120) reflected by the light guide module 120, penetrates the collimating lens group 130, and then transmitted to the wavelength conversion element 140. Then, a part of the excitation light beam L (for example, the light beam L1) is sequentially reflected by the wavelength conversion element 140, penetrates the collimating lens group 130, and then penetrates the light guide module 120, and another part of the excitation light beam is converted into a conversion light beam CB by the wavelength conversion element 140. The conversion light beam CB penetrates the collimating lens group 130 and then penetrates the light guide module 120. The part of the excitation light beam L emitted from the light guide module 120 and the conversion light beam CB form an illumination light beam IL. Among them, the excitation light beam L is, for example, a blue light beam, and the conversion light beam CB is, for example, a yellow light beam, so the illumination light beam IL can be a white light beam, which is conducive to improving color performance and uniformity performance, but the present invention is not limited to this.

[0041] In the present embodiment, the light guide module 120 has a total internal reflection surface TIR, wherein the excitation light beam L emitted from the excitation light source 110 is incident on the total internal reflection surface TIR at a first angle θ1, and the portion of the excitation light beam L or the conversion light beam CB is incident on the total internal reflection surface TIR at a second angle θ2. The first angle θ1 is greater than the critical angle of the total internal reflection surface TIR, and the second angle θ2 is less than the critical angle of the total internal reflection surface TIR.

[0042] In this embodiment, the light guide module 120 includes a first prism 122 and a second prism 124. The first prism 122 is disposed between the second prism 124 and the collimating lens group 130. The interface S1 between the first prism 122 and the second prism 124 is a total internal reflection surface TIR.

[0043] In the present embodiment, there is a gap G between the first prism 122 and the second prism 124. The material of the lighting system 100 at the gap G and the material of the first prism 122 determine the critical angle. In addition, the refractive index of the material of the first prism 122 is greater than the refractive index of the material at the gap G. By setting the material of the lighting system 100 at the gap G and the material of the first prism 122 to obtain a suitable critical angle, it is helpful to take into account the difficulty of spatial light splitting and the size of the overall space occupied by the lighting system 100. For example, the material of the first prism 122 can be glass, and the material at the gap G can be air or a glue layer whose refractive index is less than the refractive index of the material of the first prism 122, but the present invention is not limited thereto.

[0044] Figure 2 yes Figure 1 Schematic diagram of the wavelength conversion element in . Please refer to Figure 2 In this embodiment, the wavelength conversion element 140 includes a wavelength conversion region R1 and a non-wavelength conversion region R2. The portion of the excitation light beam L is incident on the non-wavelength conversion region R2, and the other portion of the excitation light beam L is incident on the wavelength conversion region R1. The excitation light beam (the other portion) is converted into a conversion light beam CB by the wavelength conversion region R1.

[0045] In this embodiment, the wavelength conversion element 140 is a stationary part or a rotatable part. When the wavelength conversion element 140 is selected as a rotatable part, the lighting system 100 generates the above-mentioned part of the excitation light beam L (for example, the light beam L1) and the conversion light beam CB at different timings. For example, at the first timing, the non-wavelength conversion area R2 cuts into the transmission path of the excitation light beam L, and the lighting system 100 generates the part of the excitation light beam L; at the second timing, the wavelength conversion area R1 cuts into the transmission path of the excitation light beam L, and the lighting system 100 generates the conversion light beam CB.

[0046] Please refer to Figure 1 In this embodiment, the lighting system 100 further includes a projection lens 150. The projection lens 150 is disposed on the transmission path of the illumination light beam IL and is used to project the illumination light beam IL out of the lighting system 100. The projection lens 150, for example, includes a combination of one or more optical lenses with diopter. The present invention does not limit the type and kind of the projection lens 150.

[0047] Based on the above, in one embodiment of the present invention, the lighting system 100 includes an excitation light source 110, a light guide module 120, a collimating lens group 130 and a wavelength conversion element 140. Moreover, the excitation light beam L emitted by the excitation light source 110 is guided to the wavelength conversion element 140 in a (total) reflection manner. Therefore, the lighting system 100 reduces the number of optical elements in the optical path and simplifies the optical path design, which can reduce the loss of light energy and thus improve the efficiency of light energy use. Moreover, under the conditions of reducing the number of optical elements and simplifying the optical path, the system cost can be reduced and the system volume can be reduced. Furthermore, the lighting beam IL includes a portion of the excitation light beam L and the conversion light beam CB, which is beneficial to improving the color performance and uniformity performance of the system. Therefore, the lighting system 100 can meet specifications such as color temperature and brightness.

[0048] Figure 3 is a schematic diagram of a lighting system according to a second embodiment of the present invention. Figure 3 , the lighting system 100' and Figure 1 The lighting system 100' is similar to the lighting system 100 of the present invention, and the main difference is that the lighting system 100' further includes an anti-reflection film 126. The anti-reflection film 126 is disposed at the interface S1 where the first prism 122 is adjacent to the second prism 124 and / or the interface S2 where the second prism 124 is adjacent to the first prism 122 is provided with the anti-reflection film 126. Since the lighting system 100' of the embodiment of the present invention is provided with the anti-reflection film 126 at the interfaces S1 and S2, the light energy loss in the system can be reduced, and the light energy utilization efficiency can be improved. The other advantages of the lighting system 100' are similar to those of the lighting system 100, and are not repeated here.

[0049] Figure 4 is a schematic diagram of a projection device according to a first embodiment of the present invention. Figure 4 One embodiment of the present invention provides a projection device 10 for generating an image beam IB. The projection device 10 includes an illumination system 100, a light valve 200, and a projection lens 150. Figure 4 The lighting system 100 and Figure 1 The lighting system 100 or Figure 3 The lighting system 100' is similar to the lighting system 100, and will not be described again here.

[0050] In addition, in this embodiment, the light valve 200 is disposed on the transmission path of the illumination light beam IL and is used to convert the illumination light beam IL into an image light beam IB. The projection lens 150 is disposed on the transmission path of the image light beam IB and is used to project the image light beam IB out of the projection device 10. The light valve 200 is disposed between the projection lens 150 and the light guide module 120. The light valve 200 may be a transmissive liquid crystal panel. The advantages of the projection device 10 are similar to those of the illumination systems 100 and 100' and are not described in detail here.

[0051] Figure 5 is a schematic diagram of a projection device according to a second embodiment of the present invention. Figure 5 , the projection device 10A and Figure 4 The projection device 10A is similar to the projection device 10 of FIG. 1 , and the main difference is that the projection device 10A further includes a curved reflector 300. The curved reflector 300 is disposed on the transmission path of the illumination light beam IL, and is used to transmit the illumination light beam IL from the light guide module 120 to the light valve 200. The reflection surface of the curved reflector 300 may be an aspherical curved surface, a free-form curved surface, or a free-form curved surface with different refractive powers on different axes perpendicular to its optical axis.

[0052] In this embodiment, the light valve 200A may be a digital micro-mirror device (DMD), wherein the curved reflector 300 is disposed between the projection lens 150 and the light valve 200A. The advantages of the projection device 10A are similar to those of the projection device 10, which will not be described in detail.

[0053] In summary, in one embodiment of the present invention, the lighting system is composed of an excitation light source, a light guide module, a collimating lens group, and a wavelength conversion element, and the excitation light beam emitted by the excitation light source is guided to the wavelength conversion element in a (total) reflection manner. Therefore, the lighting system reduces the number of optical elements in the optical path and simplifies the optical path design, which can reduce light energy loss and thus improve the efficiency of light energy use. Moreover, under the conditions of reducing optical elements and simplifying the optical path, the system cost can be reduced and the system volume can be reduced. Furthermore, the illumination light beam includes a combination of different color light beams such as a part of the excitation light beam and a conversion light beam, which is beneficial to improving the color performance and uniformity performance of the system.

[0054] The present invention has been described by the above-mentioned relevant embodiments, however, the above-mentioned embodiments are only examples for implementing the present invention. It must be pointed out that the disclosed embodiments do not limit the scope of the present invention. On the contrary, changes and modifications made without departing from the spirit and scope of the present invention are all within the scope of patent protection of the present invention.

Claims

1. A lighting system for generating a lighting beam, characterized in that: include: an excitation light source for emitting an excitation light beam; A light guide module, arranged on the transmission path of the excitation light beam; A collimating lens group is arranged on the transmission path of the excitation light beam; and The wavelength conversion element is arranged on the transmission path of the excitation light beam. After being emitted from the excitation light source, the excitation light beam is sequentially reflected by the light guide module, penetrates the collimating lens group, and then is transmitted to the wavelength conversion element. A portion of the excitation light beam is sequentially reflected by the wavelength conversion element, penetrates the collimating lens group, and then penetrates the light guide module. Another portion of the excitation light beam is converted by the wavelength conversion element into a conversion light beam, which penetrates the collimating lens group and then penetrates the light guide module. The portion of the excitation light beam emitted from the light guide module and the conversion light beam form the illumination light beam.

2. The lighting system according to claim 1, characterized in that The light guide module has a total internal reflection surface, wherein the excitation light beam emitted from the excitation light source is incident on the total internal reflection surface at a first angle, and the portion of the excitation light beam or the converted light beam is incident on the total internal reflection surface at a second angle, the first angle is greater than the critical angle of the total internal reflection surface, and the second angle is less than the critical angle of the total internal reflection surface.

3. The lighting system according to claim 2, characterized in that The light guide module comprises a first prism and a second prism, wherein the first prism is arranged between the second prism and the collimating lens group, wherein the interface between the first prism and the second prism adjacent to the total internal reflection surface.

4. The lighting system according to claim 3, characterized in that A gap is provided between the first prism and the second prism, and the critical angle is determined by the material of the lighting system at the gap and the material of the first prism.

5. The lighting system according to claim 3, characterized in that Also includes: The anti-reflection film is disposed on the interface where the first prism is adjacent to the second prism and / or disposed on the interface where the second prism is adjacent to the first prism.

6. The lighting system according to claim 1, characterized in that The wavelength conversion element includes a wavelength conversion area and a non-wavelength conversion area. The part of the excitation light beam is incident on the non-wavelength conversion area, and the other part of the excitation light beam is incident on the wavelength conversion area. The excitation light beam is converted into the conversion light beam by the wavelength conversion area.

7. The lighting system according to claim 1, characterized in that The wavelength conversion element is a stationary part or a rotatable part.

8. The lighting system according to claim 1, characterized in that Also includes: The projection lens is arranged on the transmission path of the illumination light beam and is used for projecting the illumination light beam out of the illumination system.

9. A projection device for generating an image beam, characterized in that: include: A lighting system for providing a lighting beam, wherein the lighting system is a lighting system according to any one of claims 1 to 8; a light valve disposed on a transmission path of the illumination light beam, for converting the illumination light beam into the image light beam; and The projection lens is arranged on the transmission path of the image light beam and is used for projecting the image light beam out of the projection device.

10. The projection device according to claim 9, characterized in that: The light valve is a transmissive liquid crystal panel and is arranged between the projection lens and the light guide module.

11. The projection device according to claim 9, characterized in that: Also includes: The curved reflector is arranged on the transmission path of the illumination light beam and is used for transmitting the illumination light beam from the light guide module to the light valve.

12. The projection device according to claim 11, characterized in that: The light valve is a digital micromirror element, and the curved reflector is arranged between the projection lens and the light valve.

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