Light combination system

Abstract

The invention belongs to the field of optical systems, and discloses a light combining system, exciting light emitted by a supplementary excitation light source device irradiates a wavelength conversion element to generate a wide-spectrum light beam, a light splitting and combining element I is used for guiding first polarization light and second polarization light in the wide-spectrum light beam, and compared with a traditional wavelength light combining mode, the light combining efficiency is high, and the light combining efficiency is high. Particularly, when the narrow-spectrum light beam and the wide-spectrum light beam have overlapped wave bands, the light combination efficiency is improved, and the light loss reduction effect is better.

Description

Technical Field

[0001] This invention belongs to the field of optical systems, and particularly relates to a light combining system. Background Technology

[0002] With the development of technology, laser projectors have become commonly used projection devices. Compared with traditional lamp projectors or monochrome laser projectors, three-color laser projectors, with their unique advantages, are gradually leading a new trend in projection technology. However, when using a three-color laser light source, there is usually energy loss, resulting in lower projected image quality. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention discloses a light combining system that, compared to traditional wavelength light combining methods, has higher light combining efficiency and reduces light loss. In particular, when narrow-spectrum and broadband beams have overlapping wavelengths, the system achieves even better results in improving light combining efficiency and reducing light loss.

[0004] The specific technical solution of the present invention is as follows:

[0005] A light combining system includes a broadband light source device, a narrowband light source device, and a light combining / splitting element;

[0006] The optical splitting and combining element transmits light of a first polarization state and reflects light of a second polarization state.

[0007] The broadband light source device includes an excitation light source device and a wavelength conversion element, wherein the wavelength conversion element is irradiated by the excitation light emitted by the excitation light source device to generate a broadband light beam.

[0008] The narrow-spectrum light source device emits a narrow-spectrum beam in a first polarization state or a second polarization state;

[0009] The broadband beam is incident on the first optical splitting and combining element from incident direction one, and the narrow-spectrum beam is incident on the first optical splitting and combining element from incident direction two;

[0010] The broadband beam is split into a first reflected beam and a first transmitted beam by the first beam splitter / combiner element. In the first reflected beam and the first transmitted beam, one of them is emitted in the same direction as the narrow beam emitted from the first beam splitter / combiner element to enter the beam combining direction, while the other beam is emitted to a non-beam combining direction and guided by the guide component to the second incident direction to enter the first beam splitter / combiner element. After entering the beam combining direction, it is guided by the first beam splitter / combiner element to enter the beam combining direction.

[0011] The narrow-spectrum light source device emits a narrow-spectrum beam that is transmitted through a beam splitter and combiner to enter the beam combining path. When projected onto the projection medium, it forms a projected image. The excitation light emitted by the excitation light source device irradiates a wavelength transfer element to generate a broadband beam, which is reflected or transmitted by the beam splitter and combiner to combine different colors of light into the beam combining path. This improves brightness and color performance, making the image brighter, clearer, and more vibrant and accurate. Furthermore, the beam combining process reduces light loss during transmission and helps improve the uniformity of light in the projected image, reducing bright spots and dark areas, thereby effectively improving the quality of the projected image.

[0012] Preferably, the residual excitation light emitted by the excitation light source device that is not converted after irradiating the wavelength conversion element is directed from the incident direction one to the light splitting and combining element one;

[0013] The residual excitation light is guided to the direction of light combination by the light splitting and combining element 1;

[0014] Alternatively, the residual excitation light may be emitted from the first beam splitter / combiner element along the non-combining direction to the guiding component, and then guided by the guiding component to the second incident direction to enter the beam splitter / combiner element and then into the combining direction, or the residual excitation light may be guided by the guiding component to irradiate the wavelength conversion element.

[0015] The residual excitation light can be recovered or re-excited, thereby further improving light utilization and effectively ensuring the quality of the projected image.

[0016] Preferably, a polarization conversion element is provided in the optical path from the excitation light source device to the wavelength conversion element. The residual excitation light emitted from the light splitting and combining element is guided by the guiding component through the polarization conversion element and then irradiates the wavelength conversion element.

[0017] The light splitting and combining element transmits light of the first polarization state and reflects light of the second polarization state. Therefore, when the residual excitation light can be transmitted by the light splitting and combining element, the residual excitation light is recovered. After the polarization state is switched by the polarization conversion element, it can be reflected by the light splitting and combining element. Thus, after irradiating the wavelength conversion element, the unconverted residual excitation light is refracted to the direction of light combining and is incorporated into the light combining path to further improve the image quality.

[0018] Preferably, the guiding component includes a plurality of guiding elements;

[0019] A broadband beam emitted from the beam splitter / combiner element 1 along the non-combining direction is guided sequentially by multiple guiding elements 1 to switch from incident direction 1 to incident direction 2 to form a refracted beam, which is then guided by the beam splitter / combiner element 1 to be emitted in the combining direction.

[0020] The guiding element 1 can reflect the broadband beam, so that the broadband beam transmitted from the incident direction 1 by the beam splitting and combining element 1 can be deflected to the incident direction 2, and then transmitted by the beam splitting and combining element 1 to enter the beam combining direction, thereby merging into the beam combining optical path, thus meeting the requirements of ensuring image quality.

[0021] Preferably, the guiding component includes a second polarization conversion element and a second guiding element disposed in the non-combining direction, and further includes a third polarization conversion element and a third guiding element disposed in the second incident direction;

[0022] A broadband beam emitted from the beam splitter / combiner element 1 along the non-combining direction undergoes polarization state conversion through polarization conversion element 2 and is refracted back to the beam splitter / combiner element 1 by the guide element 2 to form a reflected beam 1. The reflected beam 1 is guided by the beam splitter / combiner element 1 to the incident direction 2 and emitted in the opposite direction. The reflected beam 1 undergoes polarization state conversion through polarization conversion element 3 and is refracted back to the beam splitter / combiner element 1 by the guide element 3 to form a reflected beam 2. The reflected beam 2 is guided by the beam splitter / combiner element 1 to the combining direction and emitted.

[0023] This structure can change the polarization state of a broadband beam, so that when it is repeatedly incident at the same point of the beam splitter and combiner, there are different exit paths, thus meeting the final beam combining requirements. In other words, this structure improves the utilization rate of the excitation source device by using polarization conversion element two and polarization conversion element three.

[0024] Preferably, the excitation light source device is positioned in the non-combining direction of the light splitting and combining element one, and the excitation light emitted by the excitation light source device is incident on the light splitting and combining element one and guided by the light splitting and combining element one to irradiate the wavelength conversion element.

[0025] This technical solution achieves structural optimization, enabling secondary recovery and re-excitation of residual excitation light, which greatly improves the projection image quality.

[0026] Preferably, the second polarization conversion element and the second guiding element have openings, through which the excitation light emitted by the excitation light source device passes; or

[0027] The second polarization conversion element and the second guiding element are biased relative to the optical path of the excitation light emitted by the excitation source device, and the excitation light emitted by the excitation source device passes beside the second polarization conversion element and the second guiding element; or

[0028] A polarization conversion element four is disposed between the guiding element two and the excitation light source device. The guiding element two transmits the excitation light emitted by the excitation light source device and reflects a broadband beam. The excitation light emitted by the excitation light source device passes through the polarization conversion element four, the guiding element two, and the polarization conversion element two to maintain its original polarization state and is incident on the beam splitting and combining element one.

[0029] This technical solution achieves structural optimization and can well meet the usage requirements of the excitation light source device. In particular, in the technical solution of opening and biasing, the transmission loss of the light source can be well avoided while maintaining the polarization state.

[0030] Preferably, the polarization conversion element and the guiding element are apertured, and the narrow-spectrum light beam emitted by the narrow-spectrum light source device passes through the aperture; or

[0031] The polarization conversion element three and the guiding element three are biased relative to the optical path of the narrow-spectrum beam emitted by the narrow-spectrum light source device, and the narrow-spectrum beam emitted by the narrow-spectrum light source device passes beside the polarization conversion element three and the guiding element three; or

[0032] A polarization conversion element five is disposed between the guiding element three and the narrow-spectrum light source device. The guiding element three transmits the narrow-spectrum light beam emitted by the narrow-spectrum light source device and reflects the broadband light beam. The narrow-spectrum light beam emitted by the narrow-spectrum light source device passes through the polarization conversion element five, the guiding element three, and the polarization conversion element three to maintain its original polarization state and is incident on the beam splitting and combining element one.

[0033] This technical solution achieves structural optimization, which can well meet the usage requirements of the excitation light source device. In particular, in the technical solution of opening and biasing, the transmission loss of the light source can be well avoided while maintaining the polarization state.

[0034] Preferably, the broadband beam emitted from the beam splitter / combiner one along the non-combining direction passes through the polarization conversion element two and then illuminates the guide element two. After being refracted by the guide element two, it passes through the polarization conversion element two again to form the reflected beam one. The polarization conversion element two is a quarter-wave plate.

[0035] The reflected light 1 passes through polarization conversion element 3 and then illuminates guide element 3. After being reflected by guide element 3, it passes through polarization conversion element 3 again to form reflected light 2. Polarization conversion element 3 is a quarter-wave plate.

[0036] This structure achieves polarization state conversion by reciprocating transmission of the excitation light emitted from the excitation light source device at polarization conversion element two, and then at polarization conversion element three. Since both polarization conversion elements two and three are quarter-wave plates, the polarization state of the broadband beam emitted from beam splitter and combiner one along the non-combining direction is equivalent to the polarization state of the reflected beam two being the same. Thus, beam splitter and combiner one transmits reflected beam two, so that the broadband beam enters the combining optical path along the combining direction.

[0037] Preferably, a quarter-wave plate is disposed between the wavelength conversion element and the optical splitter / combiner.

[0038] Before the excitation light emitted by the laser source passes through the quarter-wave plate for the first time, it is transmitted by the beam splitter and combiner. When it passes through the quarter-wave plate, the phase changes by 45°. After being reflected back to the quarter-wave plate by the wavelength conversion element, the phase changes by 45°. At this time, the beam splitter and combiner can reflect the excitation light, so that the excitation light merges into the beam combiner, thereby improving the projection image quality.

[0039] Compared with existing technologies, this invention combines light by polarization, which reduces light loss and has high light combining efficiency. This invention can utilize residual excitation light to achieve re-excitation or directly merge it into the light combining path, thereby improving the projection image quality. This invention can also guide broadband beams emitted from non-light combining directions, and improve the projection image quality by polarization state conversion or reflection guidance. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of one embodiment of the present invention;

[0041] Figure 2 This is a schematic diagram illustrating the direct reflection of residual excitation light by a splitting and combining optical element according to an embodiment of the present invention;

[0042] Figure 3 This is a schematic diagram of one embodiment of the present invention;

[0043] Figure 4 This is a schematic diagram of one embodiment of the present invention;

[0044] Figure 5 This is a schematic diagram of one embodiment of the present invention;

[0045] Figure 6 A schematic diagram showing the reflector bowl in an embodiment of the present invention;

[0046] Figure 7 This is a schematic diagram of one embodiment of the present invention;

[0047] Figure 8 This is a schematic diagram of one embodiment of the present invention;

[0048] Figure 9 This is a schematic diagram showing the excitation light emitted by the excitation light source device in an embodiment of the present invention directly irradiating the wavelength conversion element;

[0049] Figure 10 This is a schematic diagram of one embodiment of the present invention.

[0050] In the diagram: 1-Narrow-spectrum light source device; 2-Splitting and combining light element one; 3-Excitation light source device; 4-Wavelength conversion element; 5-Guiding element one; 6-Polarization conversion element one; 7-Polarization conversion element two; 8-Guiding element two; 9-Polarization conversion element three; 10-Guiding element three; 11-Polarization conversion element four; 12-Polarization conversion element five; 13-Quarter-wave plate; 14-Reflecting bowl; 15-Diffusing element; 16-Beam homogenizing element; 17-Splitting and combining light element two. Detailed Implementation

[0051] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to specific embodiments.

[0052] The light combining system disclosed in this embodiment is used in projection equipment. By supplementing the excitation light source device 3, the projection image quality is effectively improved. Furthermore, by improving the excitation efficiency of the excitation light and the secondary excitation of the residual excitation light and / or merging it into the light combining path, the projection image quality is further improved.

[0053] like Figures 1-10 As shown, a light combining system includes a broadband light source device, a narrow-spectrum light source device 1, and a light-splitting / combining element 2. The light-splitting / combining element 2 transmits light of a first polarization state and reflects light of a second polarization state. The broadband light source device includes an excitation light source device 3 and a wavelength conversion element 4. The wavelength conversion element 4 is irradiated by the excitation light emitted by the excitation light source device 3 to generate a broadband light beam. The narrow-spectrum light source device 1 emits a narrow-spectrum light beam of either a first polarization state or a second polarization state. The broadband light beam enters the light-splitting / combining element 2 from an incident direction one, and the narrow-spectrum light beam enters the light-splitting / combining element 2 from an incident direction two. The broadband light beam is split into a first reflected light and a first transmitted light by the light-splitting / combining element 2. In the first reflected light and the first transmitted light, one path exits in the same direction as the narrow-spectrum light beam emitted from the light-splitting / combining element 2 and enters the light combining direction. The other path exits to a non-light combining direction and is guided by a guiding component to enter the light-splitting / combining element 2 from the incident direction two, and then is guided by the light-splitting / combining element 2 into the light combining direction.

[0054] In this embodiment, the light in the first polarization state is P-state light, and the light in the second polarization state is S-state light. The excitation light source device emits blue excitation light, and the light generated by the wavelength conversion element 4 can be yellow, green, red, or orange, etc. The narrow-spectrum light source device is specifically a laser light source device, which emits linearly polarized light, which can be P-state or S-state light, and the color can be green, red, etc. Specifically, as shown... Figure 1As shown, the narrow-spectrum light source device 1 emits P-state light from the incident direction 2 and is incident on the beam splitter / combiner 2. The beam splitter / combiner 2 then transmits the light into the beam combining direction, thus converging into the beam combining path. In this embodiment, the excitation light emitted by the excitation light source device 3 also travels from the incident direction 2 towards the beam splitter / combiner 2. The narrow-spectrum light source device 1 and the excitation light source device 3 are arranged in a concentrated manner to facilitate centralized heat dissipation, improve heat dissipation efficiency, and enhance structural compactness. The narrow-spectrum light source device 1 and the excitation light source device 3 emit light in the same direction. A color filter is provided on the light path from the narrow-spectrum light source device 1 and the excitation light source device 3 towards the beam splitter / combiner 2. The color filter transmits the narrow-spectrum light beam emitted by the narrow-spectrum light source device 1 and reflects the excitation light. The excitation light emitted by device 3 separates the narrow-spectrum light beam emitted by narrow-spectrum light source device 1 from the excitation light emitted by excitation light source device 3. The narrow-spectrum light beam emitted by narrow-spectrum light source device 1 is transmitted through the color filter and then incident on the light splitting and combining element 2 from the incident direction. The excitation light emitted by excitation light source device 3 is reflected by the color filter and then guided to irradiate the wavelength conversion element 4 to generate a broadband light beam, i.e., radiative fluorescence. Radiative fluorescence is natural light, which includes P-state light and S-state light. The broadband light beam is directed towards the light splitting and combining element 2. The S-state light in the broadband light beam is reflected by the light splitting and combining element 2 and guided to exit in the direction of light combination. The P-state light in the broadband light beam is transmitted through the light splitting and combining element 2 and exits from the direction of light combination. In this embodiment, the guiding component includes multiple guiding elements 5. P-state light from the broadband beam emitted from the beam splitter / combiner 2 along the non-combining direction is deflected by the multiple guiding elements 5 to form refracted light. The refracted light ultimately enters the beam splitter / combiner 2 from the incident direction 2. Since the refracted light is P-state light from the broadband beam, it is transmitted through the beam splitter / combiner 2 and enters the combining direction, thereby ensuring that all broadband beams emitted by the broadband light source device enter the combining optical path. The guiding elements 5 can specifically be mirrors or dichroic mirrors, primarily serving to guide and deflect the light path. In this embodiment, the plurality of guiding elements 5 include a color filter disposed in the second incident direction, and a plurality of reflectors that guide the P-state broadband beam from the first incident direction to the color filter. The P-state light in the broadband beam emitted from the beam splitter / combiner 2 along the non-combining direction is deflected and guided to illuminate the color filter. The color filter reflects the light of the broadband beam band, thereby causing the P-state light in the broadband beam to enter the beam splitter / combiner 2 from the second incident direction. The broadband beam emitted by the broadband light source device and the narrow-spectrum beam emitted by the narrow-spectrum light source device 1 can be light with completely different wavelength ranges. The broadband beam emitted by the broadband light source device and the narrow-spectrum beam emitted by the narrow-spectrum light source device 1 can also have overlapping wavelengths. For example, the broadband beam includes green fluorescence, while the narrow-spectrum light includes green laser. There is an overlapping wavelength between green fluorescence and green laser. When using the traditional wavelength combining method, the combining efficiency is low and the light loss is large. However, in this embodiment, the polarization combining method is used to improve the combining efficiency, effectively reduce the light loss of the broadband beam, and improve the output brightness.Specifically, taking a broadband beam including green fluorescence and a narrow-spectrum beam including green laser as an example, the S-state light in the green fluorescence is reflected and guided to the direction of beam recombination by the beam splitter / combiner element 2. The green laser is a P-state light, which is transmitted through the filter and the beam splitter / combiner element 2 and then emitted in the direction of beam recombination. The P-state light in the green fluorescence is transmitted through the beam splitter / combiner element 2 and then emitted in the direction of non-beam recombination. Then, the P-state light in the green fluorescence is guided to the incident filter. The filter transmits the green laser and reflects the green fluorescence, so that the P-state green laser and the P-state green fluorescence are in the same direction and incident on the beam splitter / combiner element 2 along the incident direction. Since the green laser and green fluorescence have overlapping wavelengths, that is, the wavelength range of green fluorescence includes the wavelength range of green laser. Color filters have different transmission and reflection characteristics for different wavelength bands of light. Color filters are wavelength combining devices. In fact, color filters transmit light in the green laser band and reflect light in other bands of green fluorescence except for the overlapping bands. Therefore, not all P-state light in green fluorescence is incident on the light-splitting and combining element 2 along the incident direction. The overlapping band light in P-state green fluorescence is transmitted through the color filter and not incident on the light-splitting and combining element 2 along the incident direction. In other words, the overlapping band light in P-state green fluorescence is lost. However, compared with the traditional wavelength combining method, which loses the light of the entire overlapping band (including the light of the S-state overlapping band and the light of the P-state overlapping band), this method effectively reduces light loss, improves the combining efficiency, and increases the output brightness.

[0055] In this embodiment, the wavelength conversion element 4 can be a static fluorescent element, meaning that the wavelength conversion element 4 contains only a single fluorescent region, so the broadband light source device only produces fluorescence of a single color, and the entire light source system is a non-time-sequential light source system, suitable for LCD / LCOS projection systems. The wavelength conversion element 4 can also be a dynamic element, containing multiple different fluorescent regions, each of which switches sequentially onto the optical path, thereby sequentially producing fluorescence of different colors, thus making the entire light source system a time-sequential light source system, suitable for DLP projection systems. When the wavelength conversion element 4 is a dynamic element, it contains a primary color region and a fluorescent region. The primary color region is either a light-transmitting region or a reflective region. The primary color region and the fluorescent region switch sequentially onto the optical path, thereby sequentially producing primary color light (excitation light is guided out by the wavelength conversion element 4 as part of the combined light beam) and fluorescence, thus making the entire light source system a time-sequential light source system, suitable for DLP projection systems.

[0056] Therefore, it can be seen that when the excitation light emitted by the excitation source device 3 irradiates the fluorescent region of the wavelength conversion element 4, it is difficult to fully excite and convert it into fluorescence. Consequently, a portion of the excitation light fails to convert and constitutes residual excitation light. Specifically, the excitation source device 3 can be a laser source device, for example, it can emit blue laser light. The excitation light emitted by the excitation source device 3 is linearly polarized light, which can be P-state light or S-state light. Therefore, the residual excitation light is also linearly polarized light. The residual excitation light and the broadband beam generated by the wavelength conversion element 4 travel together along the incident direction—incident beam splitter / combiner element 2. In this embodiment, as... Figure 1 As shown, the residual excitation light is transmitted from the optical splitting and combining element 2 and then emitted along the non-combining direction to the guiding component. The residual excitation light is deflected and guided by the guiding component to the second incident direction and then enters the optical splitting and combining element 2. Then, the residual excitation light is transmitted from the optical splitting and combining element 2 into the combining direction. Specifically, the excitation light source device 3 emits P-state excitation light. After the residual excitation light, which has not been converted after irradiating the wavelength conversion element 4, enters the optical splitting and combining element 2, it is transmitted by the optical splitting and combining element 2 to the reflecting mirror for guidance. The residual excitation light is then reflected by the color filter, ultimately guiding it to the second incident direction and into the optical splitting and combining element 2. The optical splitting and combining element 2 then transmits the residual excitation light into the combining optical path, thereby achieving the recovery of residual blue light. Figure 2 As shown, in one embodiment, the difference from the above embodiment is that the residual excitation light emitted by the excitation light source device 3, which irradiates the wavelength conversion element 4 but is not converted, is directed from the incident direction to the beam splitting and combining element 2; the residual excitation light is guided by the beam splitting and combining element 2 to the beam combining direction. That is, the excitation light source device 3 emits S-state excitation light, which, after irradiating the wavelength conversion element 4, is reflected by the beam splitting and combining element 2 and converted to the beam combining direction, thus merging into the beam combining path. Another embodiment differs from the above embodiment in that the residual excitation light is guided by the guiding component to irradiate the wavelength conversion element 4. Of course, as... Figure 3 Alternatively, the residual excitation light can be guided by the beam splitter / combiner element 2 and the guiding component to irradiate the wavelength conversion element 4. In other embodiments, the residual excitation light may exhibit polarization states, that is, a portion is P-state light and another portion is S-state light. In this case, the P-state residual excitation light is transmitted through the beam splitter / combiner element 2 and guided by the guiding component to the wavelength conversion element 4 for re-excitation, while the S-state residual excitation light is reflected by the beam splitter / combiner element 2 to the combined light path. This can also reduce the residual blue light in the excitation light and improve the color purity of the fluorescence.

[0057] Furthermore, a polarization conversion element 6 is provided in the optical path from the excitation light source device 3 to the wavelength conversion element 4. The residual excitation light emitted from the beam splitter / combiner element 2 is guided by a guiding component through the polarization conversion element 6 and then irradiates the wavelength conversion element 4. In this technical solution, the narrow-spectrum light source device is a pure three-color laser device, the excitation light source device 3 is a monochromatic laser device, and the color filter transmits a narrow-spectrum beam and reflects a broadband beam. Figure 3 As shown, the excitation light source device 3 emits S-state excitation light, which is converted to P-state by polarization conversion element 6 and then illuminates wavelength conversion element 4 to generate a broadband beam. The P-state broadband beam is transmitted through beam splitter / combiner element 2, guided by the guiding component, and incident on beam splitter / combiner element 2 from the incident direction, and finally transmitted through beam splitter / combiner element 2 to the combining optical path; while the S-state broadband beam is reflected by beam splitter / combiner element 2 to the combining optical path. For the residual excitation light, it is transmitted through beam splitter / combiner element 2, guided by the guiding component, transmitted through the color filter of the guiding component, converted to S-state by polarization conversion element 6, and then illuminates wavelength conversion element 4 to achieve re-excitation. Afterwards, the residual excitation light, being in S-state, is reflected by beam splitter / combiner element 2 to the combining optical path. It should be noted that a beam splitter / combiner 17 is provided before the polarization conversion element 16. The beam splitter / combiner 17 reflects S-state linearly polarized light and transmits P-state linearly polarized light, so that the excitation light emitted by the excitation light source device 3 and the recovered residual excitation light can be combined and pass through the polarization conversion element 16 and the wavelength conversion element 4 along the same optical path before being directed to the beam splitter / combiner 2. This improves the conversion efficiency of the wavelength conversion element 4 and allows the unused residual excitation light to be reflected by the beam splitter / combiner 2 into the beam combining optical path.

[0058] In one implementation, it can also be achieved using a color filter and a reflective bowl, such as... Figure 4As shown, the narrow-spectrum light source device 1 emits P-state light from the incident direction 2 and is incident on the beam splitter / combiner 2. The beam splitter / combiner 2 then transmits the light into the beam combining direction, thus converging into the beam combining path. In this embodiment, the excitation light emitted by the excitation light source device 3 also travels from the incident direction 2 towards the beam splitter / combiner 2. The narrow-spectrum light source device 1 and the excitation light source device 3 are arranged in a concentrated manner to facilitate centralized heat dissipation, improve heat dissipation efficiency, and enhance structural compactness. The narrow-spectrum light source device 1 and the excitation light source device 3 emit light in the same direction. A color filter is provided on the light path from the narrow-spectrum light source device 1 and the excitation light source device 3 towards the beam splitter / combiner 2. The color filter transmits the narrow-spectrum light beam emitted by the narrow-spectrum light source device 1 and reflects the excitation light. The excitation light emitted by device 3 separates the narrow-spectrum light beam emitted by narrow-spectrum light source device 1 from the excitation light emitted by excitation light source device 3. The narrow-spectrum light beam emitted by narrow-spectrum light source device 1 is transmitted through the color filter and then incident on the light splitting and combining element 2 from the incident direction. The excitation light emitted by excitation light source device 3 is reflected by the color filter and then guided to irradiate the wavelength conversion element 4 to generate a broadband light beam, i.e., radiative fluorescence. Radiative fluorescence is natural light, which includes P-state light and S-state light. The broadband light beam is directed towards the light splitting and combining element 2. The S-state light in the broadband light beam is reflected by the light splitting and combining element 2 and guided to exit in the direction of light combination. The P-state light in the broadband light beam is transmitted through the light splitting and combining element 2 and exits from the direction of light combination. In this embodiment, the guiding component includes a reflector bowl 14. The P-state light in the broadband beam emitted from the beam splitter / combiner 2 along the non-combining direction is refracted by the reflector bowl 14 to form refracted light. The refracted light is guided to the color filter and finally reflected by the color filter and incident on the beam splitter / combiner 2 from the incident direction 2. Since the refracted light is the P-state light in the broadband beam, the refracted light will be transmitted from the beam splitter / combiner 2 and enter the combining direction, thereby enabling all broadband beams emitted by the broadband light source device to enter the combining optical path.

[0059] like Figure 5As shown, the guiding assembly includes a second polarization conversion element 7 and a second guiding element 8 disposed in the non-combining direction, and a third polarization conversion element 9 and a third guiding element 10 disposed in the incident direction 2. A broadband beam emitted from the first beam splitting and combining element 2 along the non-combining direction undergoes polarization state conversion through the second polarization conversion element 7 and is refracted back to the first beam splitting and combining element 2 by the second guiding element 8 to form a first reflected beam. The first reflected beam is guided by the first beam splitting and combining element 2 to be emitted in the opposite direction of the incident direction 2. The first reflected beam undergoes polarization state conversion through the third polarization conversion element 9 and is refracted back to the first beam splitting and combining element 2 by the third guiding element 10 to form a second reflected beam. The second reflected beam is guided by the first beam splitting and combining element 2 to be emitted in the combining direction. In this embodiment, the second guiding element 8 and the third guiding element 10 are color filters. The second guiding element 8 transmits excitation light and reflects the broadband beam, while the third guiding element 10 transmits a narrow-spectrum beam and reflects the broadband beam. In this embodiment, the narrow-spectrum laser is a three-color laser device, and the excitation light source device 3 is a monochromatic laser device. Figure 5As shown, in one embodiment, a broadband beam emitted from the beam splitter / combiner 2 along the non-combining direction passes through the polarization conversion element 2 7 and then illuminates the guide element 2 8. After being reflected by the guide element 2 8, it passes through the polarization conversion element 2 7 again to form reflected beam 1. The polarization conversion element 2 7 is a quarter-wave plate. The reflected beam 1 passes through the polarization conversion element 3 9 and then illuminates the guide element 3 10. After being reflected by the guide element 3 10, it passes through the polarization conversion element 3 9 again to form reflected beam 2. The polarization conversion element 3 9 is a quarter-wave plate. In this embodiment, the excitation light source device 3 is positioned in the non-combining direction of the beam splitting and combining element 2. The excitation light emitted by the excitation light source device 3 is incident on the beam splitting and combining element 2 and guided by the beam splitting and combining element 2 to illuminate the wavelength conversion element 4. A polarization conversion element 4 11 is disposed between the guiding element 2 8 and the excitation light source device 3. The guiding element 2 8 transmits the excitation light emitted by the excitation light source device 3 and reflects a broadband beam. The excitation light emitted by the excitation light source device 3 passes through the polarization conversion element 4 11, the guiding element 2 8, and the polarization conversion element 2 7 to maintain its original polarization state before incident on the beam splitting and combining element 2. A polarization conversion element 5 12 is disposed between the guiding element 3 10 and the narrow-spectrum light source device 1. The guiding element 3 10 transmits the narrow-spectrum beam emitted by the narrow-spectrum light source device 1 and reflects a broadband beam. The narrow-spectrum beam emitted by the narrow-spectrum light source device 1 passes through the polarization conversion element 5 12, the guiding element 3 10, and the polarization conversion element 3 9 to maintain its original polarization state before incident on the beam splitting and combining element 2. A quarter-wave plate 13 is disposed between the wavelength conversion element 4 and the optical splitting and combining element 2. In a preferred embodiment, the polarization conversion element 4 11 and the polarization conversion element 5 12 are three-quarter wave plates.Specifically, the narrow-spectrum light beam is transmitted through polarization conversion element 5 12, guide element 3 10, and polarization conversion element 3 9 before entering the beam splitter / combiner element 2. It is then transmitted through the beam splitter / combiner element 2 and merged into the beam combining path. The excitation light source device 3 is placed to the right of the beam splitter / combiner element 2, away from the wavelength conversion element 4, emitting P-state excitation light. This excitation light sequentially penetrates polarization conversion element 4 11, guide element 2 8, and polarization conversion element 2 7, then is transmitted through the beam splitter / combiner element 2, and passes through the quarter-wave plate 13 positioned between the wavelength conversion element 4 and the beam splitter / combiner element 2 before illuminating the wavelength conversion element 4 and exciting the green phosphor to generate a broadband light beam. The broadband light beam exits from the wavelength conversion element 4 and is then transmitted through the quarter-wave plate 13. Since the broadband light beam is natural light, it passes through... After the quarter-wave plate 13, the light remains in its natural state, containing both P-state and S-state components. The broadband beam with an S-state polarization is reflected by the beam splitter / combiner element 2 and merges into the combined beam path. Meanwhile, the broadband beam with a P-state polarization is transmitted through the polarization conversion element 7, changing its phase by 45°. It is then reflected by the guide element 8 and passes through the polarization conversion element 7 again, thus changing its polarization state from P to S. Therefore, it can be reflected by the beam splitter / combiner element 2, and its path switches to the opposite direction of the incident direction 2. It is then transmitted by the polarization conversion element 9, reflected by the guide element 10, and then transmitted a second time by the polarization conversion element 9, changing its polarization state from S back to P. As a result, the reflected light 2 is transmitted through the beam splitter / combiner element 2 and enters the combined beam path. In this embodiment, the excitation light emitted by the excitation light source device 3 is P-state linearly polarized light. The excitation light is incident on the beam splitter / combiner 2 from the opposite direction of the non-combining direction and is transmitted out of the beam splitter / combiner 2 to the incident direction. The excitation light first passes through the quarter-wave plate 13 and then shines on the wavelength conversion element 4. Since the excitation light is linearly polarized, it is converted into circularly polarized or elliptically polarized light by the action of the quarter-wave plate 13. Thus, the excitation light illuminating the wavelength conversion element 4 is circularly polarized or elliptically polarized, which does not hinder the normal progress of fluorescence conversion. The residual excitation light that is not converted at the wavelength conversion element 4 is... After being reflected by the wavelength conversion element 4, the emitted light passes again through the quarter-wave plate 13 positioned between the wavelength conversion element 4 and the beam splitter / combiner element 2. The residual excitation light is either circularly polarized or elliptically polarized. Under the action of the quarter-wave plate 13, the residual excitation light is converted back to linearly polarized light. Thus, the excitation light, originally in the P-state, passes through the quarter-wave plate 13 twice, which is equivalent to passing through a half-wave plate. This changes the polarization direction of the linearly polarized light, converting the polarization state to the S-state. Consequently, the residual excitation light incident on the beam splitter / combiner element 2 is reflected by the beam splitter / combiner element 2 and enters the beam combining path. Therefore, this embodiment achieves residual excitation light recovery.In this embodiment, since the first and second reflected beams refract back and forth, when the second polarization conversion element 7 and the third polarization conversion element 9 are configured as quarter-wave plates, the excitation light can be switched between the P-state and the S-state. In some other embodiments, the first reflected beam does not refract back and forth at the second polarization conversion element 7, and similarly, the second reflected beam does not refract back and forth at the third polarization conversion element 9, for example. Figure 6 As shown, this can be achieved by configuring a reflector bowl 14, in which case polarization conversion element 2 7 and polarization conversion element 3 9 are configured as half-wave plates.

[0060] One implementation method is as follows Figure 7 As shown, the difference from the above embodiment is that polarization conversion element four 11 and polarization conversion element five 12 are not required. Specifically, polarization conversion element two 7 and guiding element two 8 have openings, through which the excitation light emitted by the excitation light source device 3 passes; polarization conversion element three 9 and guiding element three 10 have openings, through which the narrow-spectrum light beam emitted by the narrow-spectrum light source device passes. This helps to reduce light transmission loss. For example... Figure 8 In some embodiments, this is achieved by biasing. Specifically, the second polarization conversion element 7 and the second guiding element 8 are biased relative to the optical path of the excitation light emitted by the excitation light source device 3, and the excitation light emitted by the excitation light source device 3 passes beside the second polarization conversion element 7 and the second guiding element 8; the third polarization conversion element 9 and the third guiding element 10 are biased relative to the optical path of the narrow-spectrum beam emitted by the narrow-spectrum light source device 1, and the narrow-spectrum beam emitted by the narrow-spectrum light source device 1 passes beside the third polarization conversion element 9 and the third guiding element 10.

[0061] like Figures 5-8 As shown, the essence is that the excitation light source device 3 is positioned in the non-combining direction of the beam splitting and combining element 2. The excitation light emitted by the excitation light source device 3 is incident on the beam splitting and combining element 2 and guided by the beam splitting and combining element 2 to irradiate the wavelength conversion element 4. This structure achieves system optimization, facilitates the recovery of residual excitation light, and thus improves the utilization rate of the laser source. Similarly, in some embodiments, the excitation light emitted by the excitation light source device 3 is guided by a guiding component to irradiate the wavelength conversion element 4. Of course, as... Figure 9 As shown, in a basic implementation, the excitation light emitted by the excitation light source device 3 can be achieved by directly irradiating the wavelength conversion element 4.

[0062] like Figure 10As shown, in some embodiments, a system structure different from the above embodiments is also provided. The narrow-spectrum light source device 1 emits an S-state narrow-spectrum beam, which is incident on the beam splitter / combiner 2 from the incident direction 2 and reflected by the beam splitter / combiner 2 to be converted to the beam combining direction. The excitation light source device 3 is located below the beam splitter / combiner 2 and emits an S-state excitation light. The excitation light is reflected by the beam splitter / combiner 2 in the opposite direction of the incident direction 1, and is transmitted through the quarter-wave plate 13 disposed between the wavelength conversion element 4 and the beam splitter / combiner 2 to irradiate the wavelength conversion element 4 and generate a broadband beam. At this time, the P-state broadband beam is transmitted through the beam splitter / combiner element 2 and merges into the combined beam path. The S-state broadband beam is reflected by the beam splitter / combiner element 2, passes through the polarization conversion element 7 with a 45° phase change, is reflected by the guide element 8 and passes through the polarization conversion element 7 again, thus changing its polarization state from S to P. Then it is transmitted through the beam splitter / combiner element 2, passes through the polarization conversion element 9 with a 45° phase change, is reflected by the guide element 10 and passes through the polarization conversion element 9 again, thus changing its polarization state from P to S. At this time, it is reflected by the beam splitter / combiner element 2 and merges into the combined beam path. For the residual excitation light, after being reflected by the wavelength conversion element 4, it is equivalent to passing back and forth through the quarter-wave plate 13 set between the wavelength conversion element 4 and the beam splitter / combiner element 2. Therefore, the polarization state of the residual excitation light changes from S to P, and it is transmitted through the beam splitter / combiner element 2 and merges into the combined beam path. Similarly, this scheme can also improve the utilization efficiency of the excitation light source device 3. As can be seen from the above, both polarization conversion element 2 (7) and polarization conversion element 3 (9) are quarter-wave plates.

[0063] It should be noted that in all the above embodiments, a diffusion element 15, a lens assembly, a light-diffusing element 16, etc. can be set at corresponding positions. The diffusion element 15 can diffuse the light source, the lens assembly can achieve beam shaping of the light source, and the light-diffusing element 16 can achieve light homogenization, thereby better meeting the high standard requirements of projection image quality.

[0064] The above are merely preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be considered as limitations on the present invention, and the scope of protection of the present invention should be determined by the scope defined in the claims. For those skilled in the art, several improvements and modifications can be made without departing from the spirit and scope of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A light combining system, characterized by, The light source device comprises a wide-spectrum light source device, a narrow-spectrum light source device, a light splitting and combining element one; The light splitting and combining element one transmits light of a first polarization state and reflects light of a second polarization state; The wide-spectrum light source device comprises an excitation light source device and a wavelength conversion element, and the wavelength conversion element is irradiated by excitation light emitted by the excitation light source device to generate a wide-spectrum light beam; The narrow-spectrum light source device emits a narrow-spectrum light beam of the first polarization state or the second polarization state; The wide-spectrum light beam is incident on the light splitting and combining element one from an incident direction one, and the narrow-spectrum light beam is incident on the light splitting and combining element one from an incident direction two; The wide-spectrum light beam is split by the light splitting and combining element one into a first reflected light and a first transmitted light, and one of the first reflected light and the first transmitted light is emitted in the same direction as the narrow-spectrum light beam emitted from the light splitting and combining element one to enter a light combining direction, and the other is emitted to a non-light combining direction and guided by a guiding assembly to the light splitting and combining element one from the incident direction two, and then guided by the light splitting and combining element one to the light combining direction.

2. A light combining system as claimed in claim 1, characterized in that The excitation light emitted by the excitation light source device irradiates the wavelength conversion element, and residual excitation light that is not converted by the wavelength conversion element is emitted from the incident direction one to the light splitting and combining element one; The residual excitation light is guided by the light splitting and combining element one to the light combining direction; Alternatively, the residual excitation light is emitted from the light splitting and combining element one to the guiding assembly along the non-light combining direction, and the residual excitation light is guided by the guiding assembly to the light splitting and combining element one from the incident direction two to enter the light combining direction, or the residual excitation light is guided by the guiding assembly to irradiate the wavelength conversion element.

3. A light combining system as claimed in claim 2, characterized in that A polarization conversion element one is arranged on the optical path from the excitation light source device to the wavelength conversion element, and the residual excitation light emitted from the light splitting and combining element one is guided by the guiding assembly to pass through the polarization conversion element one to irradiate the wavelength conversion element.

4. A light combining system as claimed in claim 1, characterized in that The guiding assembly comprises a plurality of guiding elements one; The wide-spectrum light beam emitted from the light splitting and combining element one along the non-light combining direction is folded by the plurality of guiding elements one to form a folded light, and the folded light is incident on the light splitting and combining element one from the incident direction two and guided by the light splitting and combining element one to the light combining direction.

5. A light combining system as claimed in claim 1, characterized in that The guiding assembly comprises a polarization conversion element two and a guiding element two arranged in the non-light combining direction, and a polarization conversion element three and a guiding element three arranged in the incident direction two; The wide-spectrum light beam emitted from the light splitting and combining element one along the non-light combining direction is converted in polarization state by the polarization conversion element two and folded back to the light splitting and combining element one by the guiding element two to form a first folded-back light, the first folded-back light is emitted in reverse by the light splitting and combining element one from the incident direction two, the first folded-back light is converted in polarization state by the polarization conversion element three and folded back to the light splitting and combining element one by the guiding element three to form a second folded-back light, and the second folded-back light is guided by the light splitting and combining element one to the light combining direction.

6. A light combining system as claimed in claim 5, characterized in that The excitation light source device is arranged in the non-light combining direction of the light splitting and combining element one, and the excitation light emitted by the excitation light source device is incident on the light splitting and combining element one and guided by the light splitting and combining element one to irradiate the wavelength conversion element.

7. A light combining system as claimed in claim 6, characterized in that The polarization conversion element two and the guiding element two are apertured, and the excitation light emitted by the excitation light source device passes through the apertures; or The polarization conversion element two and the guiding element two are offset relative to the light path of the excitation light emitted by the excitation light source device, and the excitation light emitted by the excitation light source device passes from the side of the polarization conversion element two and the guiding element two; or A polarization conversion element four is arranged between the guiding element two and the excitation light source device, the guiding element two transmits the excitation light emitted by the excitation light source device and reflects the broadband light beam, and the excitation light emitted by the excitation light source device passes through the polarization conversion element four, the guiding element two and the polarization conversion element two and then enters the beam combining and splitting element one with the original polarization state unchanged.

8. A light combining system as claimed in claim 6, characterized in that A quarter-wave plate is arranged between the wavelength conversion element and the beam combining and splitting element one.

9. A light combining system as claimed in claim 5, wherein, The polarization conversion element three and the guiding element three have an aperture, and the narrow-spectrum light beam emitted by the narrow-spectrum light source device passes through the aperture; or The polarization conversion element three and the guiding element three are offset relative to the light path of the narrow-spectrum light beam emitted by the narrow-spectrum light source device, and the narrow-spectrum light beam emitted by the narrow-spectrum light source device passes from the side of the polarization conversion element three and the guiding element three; or A polarization conversion element five is arranged between the guiding element three and the narrow-spectrum light source device, the guiding element three transmits the narrow-spectrum light beam emitted by the narrow-spectrum light source device and reflects the broadband light beam, and the narrow-spectrum light beam emitted by the narrow-spectrum light source device passes through the polarization conversion element five, the guiding element three and the polarization conversion element three and then enters the beam combining and splitting element one with the original polarization state unchanged.

10. A light combining system as claimed in claim 5, characterized in that The broadband light beam emitted from the beam combining and splitting element one in the non-combining direction passes through the polarization conversion element two and then irradiates on the guiding element two, and is folded back by the guiding element two and then passes through the polarization conversion element two again to form the first folded light, and the polarization conversion element two is a quarter-wave plate; The first folded light passes through the polarization conversion element three and then irradiates on the guiding element three, and is folded back by the guiding element three and then passes through the polarization conversion element three again to form the second folded light, and the polarization conversion element three is a quarter-wave plate.

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