Lighting system and projection device

Abstract

The present application provides a kind of illumination system and projection device.The illumination system includes light source module, wavelength conversion module and light splitting module.Light source module includes first laser module, second laser module, third laser module and fourth laser module, respectively provides first laser beam, second laser beam, third laser beam and fourth laser beam.Wavelength conversion module includes first wavelength conversion element and second wavelength conversion element, to respectively convert first laser beam into first wavelength conversion beam, and convert second laser beam into second wavelength conversion beam.Light splitting module includes first dichroic mirror, second dichroic mirror and third dichroic mirror, respectively configured on the transmission path of first laser beam, second laser beam and third laser beam and fourth laser beam.The illumination system and projection device of the present application can effectively suppress color break and laser speckle phenomenon, achieve good optical effect.

Description

Technical Field

[0001] This invention relates to an optical system and apparatus, and more particularly to an illumination system and projection apparatus. Background Technology

[0002] With the development of projection technology, users are increasingly demanding higher image quality from projectors. In some projector models, a laser light source is combined with a phosphor wheel (wavelength conversion wheel) as the illumination beam. However, these projectors utilize the rotation of the phosphor wheel to sequentially provide beams of different colors of light, which often results in color breaking due to the slow response speed of the phosphor wheel. Specifically, when the phosphor wheel rotates slowly, the frequency of color switching per unit time is low, causing the human eye to perceive rainbow patterns. However, increasing the phosphor wheel's rotation speed to improve color breaking results in excessive noise from the motor driving the phosphor wheel.

[0003] Laser projectors, which use red, green, and blue laser light sources as illumination beams, are gradually entering the mainstream projector market due to their high color purity and ability to achieve high color gamut coverage. However, the high coherence of laser light sources makes laser projector images prone to laser speckle.

[0004] On the other hand, hybrid light source technology has become one of the latest projection technologies to improve optical efficiency and image quality. In hybrid light source technology, the light source can simultaneously include lasers, fluorescent excitation light, or light-emitting diodes, etc. Hybrid light sources can effectively solve the image speckle caused by lasers, and can also achieve advantages such as improved efficiency and color gamut.

[0005] The "Background Art" paragraph is only used to help understand the content of this invention. Therefore, the content disclosed in the "Background Art" paragraph may include some known technologies that are not known to those skilled in the art. The content disclosed in the "Background Art" paragraph does not mean that the content or the problems to be solved by one or more embodiments of this invention were known or understood by those skilled in the art prior to this application. Summary of the Invention

[0006] This invention provides a lighting system and projection device that can effectively suppress color cracking and laser speckle, achieving excellent optical effects.

[0007] Other objects and advantages of the present invention can be further understood from the technical features disclosed herein.

[0008] To achieve one or more of the above-mentioned objectives, or other objectives, one embodiment of the present invention provides an illumination system, including a light source module, a wavelength conversion module, a beam splitting module, and a beam homogenizing module. The light source module includes a first laser module, a second laser module, a third laser module, and a fourth laser module, which respectively provide a first laser beam, a second laser beam, a third laser beam, and a fourth laser beam. The wavelength conversion module includes a first wavelength conversion element and a second wavelength conversion element. The first wavelength conversion element is disposed on the transmission path of the first laser beam and is used to convert the first laser beam into a first wavelength-converted beam. The second wavelength conversion element is disposed on the transmission path of the second laser beam and is used to convert the second laser beam into a second wavelength-converted beam. The beam splitting module includes a first dichroic mirror, a second dichroic mirror, and a third dichroic mirror. The first dichroic mirror is positioned along the transmission path of the first laser beam from the first laser module to the first wavelength conversion element, allowing light within the first wavelength range and light outside the first wavelength range to either reflect or pass through. The second dichroic mirror is positioned along the transmission path of the second laser beam from the second laser module to the second wavelength conversion element, allowing light within the second wavelength range and light outside the second wavelength range to either reflect or pass through. The third dichroic mirror is positioned along the transmission path of the third and fourth laser beams, transmitting both beams to the second dichroic mirror. The first wavelength-converted beam is filtered by the first dichroic mirror into a first color light with the first wavelength range, and the first dichroic mirror guides the first color light into the beam homogenizing module. The second wavelength-converted beam is filtered by the second dichroic mirror into a second color light with the second wavelength range, and the second dichroic mirror guides the second color light into the beam homogenizing module. The third and fourth laser beams are sequentially guided by the second and first dichroic mirrors and then incident on the homogenizing module. The color of the fourth laser beam is the same as the color of either the first or second color light. The homogenizing module homogenizes the first, second, third, and fourth laser beams to generate an illumination beam.

[0009] To achieve one or more of the above-mentioned objectives, or other objectives, one embodiment of the present invention provides a projection device, including the aforementioned illumination system, light valve module, and lens module. The illumination system provides an illumination beam, the light valve module is disposed in the transmission path of the illumination beam, and is used to convert the illumination beam into an image beam. The lens module is disposed in the transmission path of the image beam, and is used to project the image beam outside the projection device.

[0010] Based on the above, the lighting system and projection device of the embodiments of the present invention have at least one of the following advantages: In the lighting system and projection device of the embodiments of the present invention, a first laser module, a first wavelength conversion element, and a first dichroic mirror are used to generate a first color light, and a second laser module, a second wavelength conversion element, and a second dichroic mirror are used to generate a second color light. Therefore, the first color light, the second color light, and the third laser beam can be independently turned on and off, without being limited by hardware limitations such as motors or color wheels, which can significantly improve the color update rate without color distortion. Furthermore, in the lighting system and projection device of the embodiments of the present invention, the color of the fourth laser beam is the same as the color of the first color light or the second color light. The first color light and the second color light are converted by the wavelength conversion element and filtered by the first dichroic mirror and the second dichroic mirror, respectively, without laser speckle. Therefore, by combining the first color light with the fourth laser beam or the second color light with the fourth laser beam, speckle can be effectively suppressed. Furthermore, the first color light filtered by the first dichroic mirror and the second color light filtered by the second dichroic mirror can have high color purity, thus effectively improving the color gamut coverage. Attached Figure Description

[0011] Figure 1A , Figure 1B , Figure 1C and Figure 1D These are schematic diagrams of the optical paths of a lighting system according to an embodiment of the present invention, showing the transmission of the first color light, the second color light, the third laser beam, and the third color light to the uniform light module.

[0012] Figure 2 for Figures 1A to 1D A schematic diagram of the spectra of the first, second, and third laser beams, the reflectance spectrum of the first dichroic mirror, the reflectance spectrum of the second dichroic mirror, the reflectance spectrum of the third dichroic mirror, and the spectrum of the fourth laser beam.

[0013] Figure 3 for Figures 1A to 1D The excitation spectrum curves of the wavelength conversion regions of the first wavelength conversion element and the second wavelength conversion element.

[0014] Figure 4 This is a schematic diagram of a projection device according to an embodiment of the present invention.

[0015] Figure 5 for Figure 4 A schematic diagram of the beam timing of the projection device.

[0016] Figure 6A and Figure 6B This is a front view schematic diagram of a wavelength conversion module in a lighting system according to two other embodiments of the present invention.

[0017] Figure 7 This is a front view schematic diagram of a wavelength conversion module in a lighting system according to another embodiment of the present invention.

[0018] Figure 8A , Figure 8B , Figure 8C and Figure 8D The above are schematic diagrams of the optical paths of the lighting system according to another embodiment of the present invention when the first color light, the second color light, the third laser beam and the third color light are transmitted to the light uniform module.

[0019] Figure 9 This is a simplified three-dimensional schematic diagram showing the optical path position relationship between the third laser module and the uniform light module in a lighting system according to another embodiment of the present invention.

[0020] Figure 10 This is a schematic diagram of the beam timing of a projection device according to another embodiment of the present invention.

[0021] Figure 11 This is a schematic diagram of the optical path of the lighting system according to another embodiment of the present invention when the third color light is transmitted to the uniform light module.

[0022] Figure 12 To adopt Figure 11 A schematic diagram of the beam timing of the projection device in the lighting system.

[0023] Figure 13 This is a simplified schematic diagram of the optical path of a lighting system according to another embodiment of the present invention. Detailed Implementation

[0024] The foregoing descriptions and other technical contents, features, and effects of this invention will be clearly presented in the following detailed description of a preferred embodiment with reference to the accompanying drawings. The directional terms used in the following embodiments, such as up, down, left, right, front, or back, are merely for reference to the accompanying drawings. Therefore, the directional terms used are for illustrative purposes and not for limiting the invention.

[0025] Figure 1A , Figure 1B , Figure 1C and Figure 1D The diagram shows the optical path of a lighting system according to an embodiment of the present invention as the first color light, the second color light, the third laser beam, and the third color light are transmitted to the uniform light module. Please refer to... Figures 1A to 1DThe lighting system 100 of this embodiment includes a light source module 200, a wavelength conversion module 300, a beam splitting module 400, and a light homogenizing module 110. The light source module 200 includes a first laser module 210, a second laser module 220, a third laser module 230, and a fourth laser module 240, which respectively provide a first laser beam 211, a second laser beam 221, a third laser beam 231, and a fourth laser beam 241. The wavelength conversion module 300 includes a first wavelength conversion element 310 and a second wavelength conversion element 320. The first wavelength conversion element 310 is disposed on the transmission path of the first laser beam 211 and is used to convert the first laser beam 211 into a first wavelength-converted beam 311. The second wavelength conversion element 320 is disposed on the transmission path of the second laser beam 221 and is used to convert the second laser beam 221 into a second wavelength-converted beam 321. In this embodiment, the first wavelength conversion element 310 is not disposed on the transmission paths of the second laser beam 221, the third laser beam 231 and the fourth laser beam 241, and the second wavelength conversion element 320 is not disposed on the transmission paths of the first laser beam 211, the third laser beam 231 and the fourth laser beam 241.

[0026] In this embodiment, the first laser module 210, the second laser module 220, the third laser module 230, and the fourth laser module 240 may each include multiple laser diodes 202, one or more reflectors 204, and one or more beam combiners 206. The beam combiners 206 and reflectors 204 in each laser module can combine the beams emitted by the multiple laser diodes 202 into a single laser beam, such as a first laser beam 211, a second laser beam 221, a third laser beam 231, or a fourth laser beam 241. In this way, by adjusting the configuration of the components in the first laser module 210, the second laser module 220, the third laser module 230, and the fourth laser module 240, the optical path can be shifted or bent to reduce the overall optical path volume of the system. In addition, one or more lenses 130 may be provided on the transmission path of each beam, and the lenses 130 can collimate or converge the beams. It should be noted that the number of laser diodes 202, reflectors 204, light combining elements 206, and lenses 130 used in the lighting system 100 can be increased or decreased according to actual needs, and is not limited to a fixed quantity. Figures 1A to 1D The number of elements shown is limited.

[0027] Figure 2 for Figures 1A to 1DThe diagram shows the spectra of the first, second, and third laser beams, the reflectance spectrum of the first dichroic mirror, the reflectance spectrum of the second dichroic mirror, the reflectance spectrum of the third dichroic mirror, and the spectrum of the fourth laser beam. Please refer to... Figures 1A to 1D and Figure 2The beam splitting module 400 includes a first dichroic mirror 410, a second dichroic mirror 420, and a third dichroic mirror 430. The first dichroic mirror 410 is disposed on the transmission path of the first laser beam 211 from the first laser module 210 to the first wavelength conversion element 310, so as to allow one of the light in the first wavelength range W1 and the light outside the first wavelength range W1 to be reflected and the other to be transmitted (in this embodiment, for example, the light in the first wavelength range W1 is reflected and the light outside the first wavelength range W1 is transmitted). The second dichroic mirror 420 is disposed on the second laser beam... Laser beam 221 is positioned along the transmission path from the second laser module 220 to the second wavelength conversion element 320, allowing one of the light in the second wavelength range W2 and light outside the second wavelength range W2 to be reflected and the other to pass through (in this embodiment, for example, light in the second wavelength range W2 is reflected, and light outside the second wavelength range W2 is passed through). A third dichroic mirror 430 is positioned along the transmission path of the third laser beam 231 and the fourth laser beam 241, transmitting both beams to the second dichroic mirror 420. In this embodiment, the third dichroic mirror 430 reflects the third laser beam 231 from the third laser module 230 and allows the fourth laser beam 241 from the fourth laser module 240 to pass through. In this embodiment, the third wavelength range W3 reflected by the third dichroic mirror 430 is between 435-485 nm, and the center wavelength of the fourth laser beam 241 is greater than 636 nm. However, in other embodiments, the third dichroic mirror 430 may be used to allow the third laser beam 231 to pass through and to reflect the fourth laser beam 241. Furthermore, in this embodiment, the third laser module 230 and the fourth laser module 240 are both disposed on the same side of the second dichroic mirror 420. Moreover, in this embodiment, the center wavelengths of the first laser beam 211, the second laser beam 221, and the third laser beam 231 are the same. In one embodiment, the wavelength range of the first laser beam 211, the second laser beam 221, and the third laser beam 231 is 450 nm to 475 nm. However, in other embodiments, the center wavelengths of the first laser beam 211 and the second laser beam 221 are the same, and the center wavelengths of the first laser beam 211 and the second laser beam 221 are different from the center wavelength of the third laser beam 231. In one embodiment, the first wavelength range W1 is between 491 and 582 nm, and the second wavelength range W2 is between 583 and 636 nm. In one embodiment, at least a portion of the wavelength range of the first wavelength conversion beam 311 is not located in the first wavelength range W1, and at least a portion of the wavelength range of the second wavelength conversion beam 321 is not located in the second wavelength range W2. Therefore, the first dichroic mirror 410 and the second dichroic mirror 420 can filter out the first wavelength conversion beam 311 and the second wavelength conversion beam 321 to produce purer first color light 411 and second color light 421.In this embodiment, the spectra of the first color light 411 and the second color light 421 do not overlap. However, in other embodiments, the spectra of the first color light 411 and the second color light 421 may partially overlap, for example, the overlap range of the spectra of the first color light 411 and the second color light 421 is less than 15% of the range of the spectra of the first color light 411 and the second color light 421, respectively. Furthermore, in this embodiment, the transmittance of the fourth laser beam 241 through both the first dichroic mirror 410 and the second dichroic mirror 420 is greater than 90%.

[0028] The first wavelength conversion beam 311 is filtered by the first dichroic mirror 410 into a first color light 411 having a first wavelength range W1. The first dichroic mirror 410 guides the first color light 411 into the light homogenizing module 110. The second wavelength conversion beam 321 is filtered by the second dichroic mirror 420 into a second color light 421 having a second wavelength range W2. The second dichroic mirror 420 guides the second color light 421 into the light homogenizing module 110. In this embodiment, the first dichroic mirror 410 filters the first wavelength conversion beam 311 into the first color light 411 and reflects the first color light 411, allowing the first color light 411 to be transmitted to the light homogenizing module 110. The second dichroic mirror 420 filters the second wavelength conversion beam 321 into the second color light 421 and reflects the second color light 421, allowing the second color light 421 to then pass through the first dichroic mirror 410 and be transmitted to the light homogenizing module 110. The third laser beam 231 and the fourth laser beam 241 are sequentially guided by the second dichroic mirror 420 and the first dichroic mirror 410 and incident on the homogenizing module 110. The color of the fourth laser beam 241 is the same as the color of the first color light 411 or the second color light 421. In this embodiment, the first color light 411 is, for example, green light, the second color light 421 is, for example, red light, the first laser beam 211, the second laser beam 221, and the third laser beam 231 are, for example, blue lasers, and the fourth laser beam 241 is, for example, red lasers. The homogenizing module 110 homogenizes the first color light 411, the second color light 421, the third laser beam 231, and the fourth laser beam 241 to generate an illumination beam 111. In this embodiment, the homogenizing module 110 is, for example, a light integrating column or a lens array. Furthermore, in this embodiment, the illumination beam 111 at a given time includes at least one of the first color light 411, the second color light 421, the third laser beam 231, and the fourth laser beam 241.

[0029] like Figures 1A to 1D The two bottommost ring-shaped structures schematically illustrate the front views of the first wavelength conversion element 310 and the second wavelength conversion element 320, respectively. The wavelength conversion region 312 of the first wavelength conversion element 310 and the wavelength conversion region 322 of the second wavelength conversion element 320 are both ring-shaped, for example, O-rings. Furthermore, Figures 1A to 1DThe positions of the first laser beam 211 illuminating the spot S1 of the first wavelength conversion element 310 and the second laser beam 221 illuminating the spot S2 of the second wavelength conversion element 320 are schematically shown.

[0030] Figure 3 for Figures 1A to 1D The excitation spectrum curves of the wavelength conversion regions of the first and second wavelength conversion elements are shown below. Please refer to... Figures 1A to 1D and Figure 3 In this embodiment, the excitation spectrum of the wavelength conversion region 312 of the first wavelength conversion element 310 is different from the excitation spectrum of the wavelength conversion region 322 of the second wavelength conversion element 320. In one embodiment, the wavelength conversion region 312 of the first wavelength conversion element 310 contains, for example, green phosphor, which is suitable for being excited to generate green light, and the wavelength conversion region 322 of the second wavelength conversion element 320 contains, for example, yellow phosphor, which is suitable for being excited to generate yellow light. The excitation spectra of the wavelength conversion regions 312 and 322 are as follows: Figure 3 As illustrated. However, in other embodiments, the excitation spectrum of the wavelength conversion region 312 of the first wavelength conversion element 310 may also be the same as the excitation spectrum of the wavelength conversion region 322 of the second wavelength conversion element 320. For example, wavelength conversion region 312 and wavelength conversion region 322 may both contain green phosphor, or both contain yellow phosphor. In this embodiment, the first wavelength conversion element 310 is adapted to rotate about its central axis A1 so that the first laser beam 211 irradiates different positions of the wavelength conversion region 312 at different time points to avoid overheating of the first wavelength conversion element 310. In addition, the second wavelength conversion element 320 is adapted to rotate about its central axis A2 so that the second laser beam 221 irradiates different positions of the wavelength conversion region 322 at different time points to avoid overheating of the second wavelength conversion element 320. In other words, in this embodiment, both the first wavelength conversion element 310 and the second wavelength conversion element 320 are rotatable moving parts, and the rotational speeds of the first wavelength conversion element 310 and the second wavelength conversion element 320 may be the same or different. However, in other embodiments, the first wavelength conversion element 310 and the second wavelength conversion element 320 may also be fixed components.

[0031] Figure 4This is a schematic diagram of a projection device according to an embodiment of the present invention. The projection device 500 of this embodiment includes the aforementioned illumination system 100, light valve module 510, and lens module 520. The illumination system 100 provides an illumination beam 111. The light valve module 510 is disposed on the transmission path of the illumination beam 111 and is used to convert the illumination beam 111 into an image beam 511. The lens module 520 is disposed on the transmission path of the image beam 511 and is used to project the image beam 511 outside the projection device 500, for example, onto a screen or imaging surface outside the projection device 500, to form a projected image. In this embodiment, the light valve module 510 is, for example, a digital micromirror device (DMD), a liquid-on-silicon panel (LCOS panel), or other suitable spatial light modulator, which can modulate the illumination beam 111 into the image beam 511. Lens module 520 may include, for example, a combination of one or more optical lenses having diopter, such as various combinations of non-planar lenses including biconcave lenses, biconvex lenses, concave-convex lenses, convex-concave lenses, plano-convex lenses, and plano-concave lenses. In one embodiment, lens module 520 may also include an optical reflector to project the image beam 511 from light valve module 510 onto the projection target by reflection. Embodiments of the present invention do not limit the type or form of lens module 520.

[0032] Figure 5 for Figure 4 The beam timing diagram of the projection device. Please also refer to... Figures 1A to 1D and Figure 5In this embodiment, the first laser module 210, the second laser module 220, and the third laser module 230 are respectively used to provide the first laser beam 211, the second laser beam 221, and the third laser beam 231 at different times. The fourth laser module 240 provides the fourth laser beam 241 during the time period when the first laser module 210 provides the first laser beam 211 or during the time period when the second laser module 220 provides the second laser beam 221. In this embodiment, the fourth laser beam 241 is, for example, red, the first color light 411 is, for example, green, and the second color light 421 is, for example, red. Since the color of the fourth laser beam 241 is the same as the color of the second color light 421, the fourth laser module 240 provides the fourth laser beam 241 during the time period when the second laser module 220 provides the second laser beam 221. That is, when the color of the fourth laser beam 241 is the same as the color of the second color light, the time period during which the fourth laser beam 241 is provided is the same as the time period during which the second laser module 220 provides the second laser beam 221. In other embodiments, the color of the fourth laser beam 241 is the same as the color of the first light 411. For example, both the fourth laser beam 241 and the first light 411 are green. In this case, the fourth laser module 240 provides the fourth laser beam 241 during the same period when the first laser module 210 provides the first laser beam 211, but this is not a limitation.

[0033] exist Figure 5 In the timing diagram, when the illumination beam 111 is green, it is represented by "G"; when the illumination beam 111 is red, it is represented by "R"; and when the illumination beam 111 is blue, it is represented by "B". Figure 5 The time sequence of the G period in the text corresponds to... Figure 1A In this state, the first laser module 210 is turned on, while the second laser module 220, the third laser module 230, and the fourth laser module 240 are turned off. The first laser beam 211 provided by the first laser module 210 passes through the first dichroic mirror 410 and illuminates the first wavelength conversion element 310, generating a light spot S1 on the wavelength conversion region 312. The first wavelength conversion element 310 converts the incident first laser beam 211 to generate a first wavelength conversion beam 311, and transmits the first wavelength conversion beam 311 to the first dichroic mirror 410. The first dichroic mirror 410 filters out the purer first color light 411 (green light) from the first wavelength conversion beam 311, and guides (e.g., reflects) the first color light 411 to the homogenizing module 110. During the timing of period G, the illumination beam 111 received by the light valve module 510 is the green first color light 411.

[0034] Figure 5 The time sequence of the R period in the text corresponds to... Figure 1BAt this time, the second laser module 220 and the fourth laser module 240 are turned on, while the first laser module 210 and the third laser module 230 are turned off. The second laser beam 221 provided by the second laser module 220 passes through the second dichroic mirror 420 and irradiates the second wavelength conversion element 320, generating a light spot S2 on the wavelength conversion region 322. The second wavelength conversion element 320 converts the incident second laser beam 221 to generate a second wavelength conversion beam 321, and transmits the second wavelength conversion beam 321 to the second dichroic mirror 420. The second dichroic mirror 410 filters out the second wavelength conversion beam 321 to obtain a purer second color light 421 (red light), and guides (e.g., reflects) the second color light 421 to the first dichroic mirror 410, so that the second color light 421 penetrates the first dichroic mirror 410 and is transmitted to the light homogenizing module 110. The fourth laser beam 241 provided by the fourth laser module 240, after being guided (e.g., penetrated) by the third dichroic mirror 430, is sequentially guided by the second dichroic mirror 420 and the first dichroic mirror 410 and then incident on the homogenizing module 110. During the R-period, the illumination beam 111 received by the light valve module 510 consists of the red second-color light 421 and the red fourth laser beam 241.

[0035] Figure 5 The B time period in the text corresponds to Figure 1C At this time, the third laser module 230 is turned on, while the first laser module 210, the second laser module 220, and the fourth laser module 240 are turned off. The third laser beam 231 provided by the third laser module 230, after being guided (e.g., reflected) by the third dichroic mirror 430, is sequentially guided by the second dichroic mirror 420 and the first dichroic mirror 410 and then incident on the homogenizing module 110. During the timing of time segment B, the illumination beam 111 received by the light valve module 510 is the blue third laser beam 231.

[0036] In this embodiment, the aforementioned G-period, R-period, and B-period constitute a time period. However, in other embodiments, a time period may further include the timing of the Y-period when the illumination beam 111 is yellow light, and the timing of the Y-period is between the G-period and the R-period. Figure 5 The time sequence of the Y period in the text corresponds to... Figure 1DAt this time, the first laser module 210, the second laser module 220, and the fourth laser module 240 are turned on, while the third laser module 230 is turned off. That is, for the fourth laser module 240, the time period during which it provides the fourth laser beam 241 partially overlaps with the time period during which the first laser module 210 and the second laser module 220 simultaneously provide the first laser beam 211 and the second laser beam 221. During the Y-time period, the first color light 411, the second color light 421, and the fourth laser beam 241 are all guided to the homogenizing module 110 to form a yellow third color light. Thus, the illumination beam 111 received by the light valve module 510 is a yellow third color light, which includes the green first color light 411, the red second color light 421, and the red fourth laser beam 241.

[0037] In other embodiments, the time period during which the third laser module 230 provides the third laser beam 231 partially overlaps with the time period during which the first laser module 210 provides the first laser beam 211 or the second laser module 220 provides the second laser beam 221, thereby combining the third laser beam 231 with the first color light 411 or the third laser beam 231 with the second color light 421 to form a fourth color light. Figure 5 In this time period, a time cycle may further include a C period following the B period. During this time, the first laser module 210 and the third laser module 230 are turned on, while the second laser module 220 and the fourth laser module 240 are turned off. That is, for the third laser module 230, the time period during which the third laser module 230 provides the third laser beam 231 partially overlaps with the time period during which the first laser module 210 provides the first laser beam 211. During the C period, the third laser beam 231 and the first color light 411 are both guided to the homogenizing module 110 to form a cyan fourth color light. Thus, the illumination beam 111 received by the light valve module 510 is a cyan fourth color light, which includes the blue third laser beam 231 and the green first color light 411. Figure 5 In another embodiment not shown, a time period may further include an M-period between the R-period and the B-period. During this time, the second laser module 220 and the third laser module 230 are turned on, while the first laser module 210 and the fourth laser module 240 are turned off. That is, for the third laser module 230, the time period during which the third laser module 230 provides the third laser beam 231 partially overlaps with the time period during which the second laser module 220 provides the second laser beam 221. During the M-period, both the third laser beam 231 and the second color light 421 are guided to the homogenizing module 110 to form a magenta fourth color light. Thus, the illumination beam 111 received by the light valve module 510 is a magenta fourth color light, which includes the blue third laser beam 231 and the red second color light 421.

[0038] In the lighting system 100 and projection device 500 of this embodiment, a first laser module 210, a first wavelength conversion element 310, and a first dichroic mirror 410 are used to generate a first colored light 411, and a second laser module 220, a second wavelength conversion element 320, and a second dichroic mirror 420 are used to generate a second colored light 421. Therefore, the first colored light 411, the second colored light 421, and the third laser beam 231 can be independently turned on and off, without being limited by hardware limitations such as motors or color wheels, which can significantly improve the color update rate without color distortion. In existing projection devices, phosphor wheels with different color ranges are used. While increasing the number of color ranges to improve the color update rate, it also increases the number of boundaries between different color ranges. The existing approach is to close the light valve when the laser beam irradiates the boundary to avoid incorrect color irradiation at the light valve, but this reduces the brightness of the image beam converted by the light valve. In contrast, in this embodiment, the wavelength conversion region 312 of the first wavelength conversion element 310 and the wavelength conversion region 322 of the second wavelength conversion element 320 are both complete O-rings without different color ranges. Therefore, there is no problem of the brightness of the image beam being reduced due to the boundary of different color ranges. Thus, the lighting system 100 and the projection device 500 in this embodiment can have good brightness.

[0039] Furthermore, in the lighting system 100 and projection device 500 of this embodiment, the color of the fourth laser beam 241 is the same as the color of the first color light 411 or the second color light 421. The first color light 411 and the second color light 421 are converted by wavelength conversion elements and filtered by the first dichroic mirror 410 and the second dichroic mirror 420 respectively, thus avoiding laser speckle. Therefore, by combining the first color light 411 with the fourth laser beam 241 or the second color light 421 with the fourth laser beam 241, speckle can be effectively suppressed. High coherence of laser light easily causes laser speckle, which is more severe with red and green lasers. Therefore, in this embodiment, by combining the red second color light 421 with the red fourth laser beam 241, the laser speckle caused by the fourth laser beam 241 can be effectively suppressed. In this embodiment, the lighting system 100 may further include a diffusion element 120 disposed in the transmission path of the fourth laser beam 241, for example, located between the fourth laser module 240 and the second dichroic mirror 420, thereby suppressing the laser speckle phenomenon caused by the fourth laser beam 241. The diffusion element 120 may be a fixed element or a moving element. Furthermore, the first color light 411 filtered by the first dichroic mirror 410 and the second color light 421 filtered by the second dichroic mirror 420 can have high color purity, purifying the green and red light spots, thus effectively improving the color gamut coverage.

[0040] Figure 6A and Figure 6B This is a front view schematic diagram of a wavelength conversion module in a lighting system according to two other embodiments of the present invention. Figure 6A and Figure 6B In the middle, wavelength conversion modules 300a and 300b and Figures 1A to 1D The wavelength conversion module 300 is similar to that of the other two, but the main differences are as follows. In wavelength conversion modules 300a and 300b, the first wavelength conversion element 310 and the second wavelength conversion element 320 are disposed on the same rotating substrate 305, and the distance from the first wavelength conversion element 310 to the central axis A3 of the rotating substrate 305 is not equal to the distance from the second wavelength conversion element 320 to the central axis A3 of the rotating substrate 305.

[0041] Specifically, in Figure 6A In the embodiment, the wavelength conversion region 312 of the first wavelength conversion element 310 of the wavelength conversion module 300a is radially farther away from the central axis A3 (i.e., the outer ring), and the wavelength conversion region 322 of the second wavelength conversion element 320 is radially closer to the central axis A3 (i.e., the inner ring). The distance D1 between the light spot S1 generated by the first laser beam 211 on the first wavelength conversion element 310 and the light spot S2 generated by the second laser beam 221 on the second wavelength conversion element 320 is greater than the diameter D2 of the second wavelength conversion element 320.

[0042] And in Figure 6B In the embodiment, the wavelength conversion region 312 of the first wavelength conversion element 310 of the wavelength conversion module 300b is closer to the central axis A3 (i.e., the inner circle) in the radial direction, and the wavelength conversion region 322 of the second wavelength conversion element 320 is farther away from the central axis A3 (i.e., the outer circle) in the radial direction.

[0043] Figure 7 This is a front view schematic diagram of a wavelength conversion module in a lighting system according to another embodiment of the present invention. Please refer to... Figure 7 In this embodiment, the wavelength conversion module 300c and Figures 1A to 1D Similar to the wavelength conversion module 300, the main differences are as follows. In the wavelength conversion module 300c of this embodiment, the line connecting the central axis A1 of the first wavelength conversion element 310 and the central axis A2 of the second wavelength conversion element 320 is defined as the first connecting line L1, and the line connecting the light spot S1 generated by the first laser beam 211 on the first wavelength conversion element 310 and the light spot S2 generated by the second laser beam 221 on the second wavelength conversion element 320 is defined as the second connecting line L2. The angle between the first connecting line L1 and the second connecting line L2 is not zero. In other words, the first wavelength conversion element 310 and the second wavelength conversion element 320 can be staggered according to requirements to reduce the size of the lighting system and projection device.

[0044] Figure 8A , Figure 8B , Figure 8C and Figure 8D The diagram shows the optical path of the lighting system according to another embodiment of the present invention as the first color light, the second color light, the third laser beam, and the third color light are transmitted to the uniform light module. Please refer to... Figures 8A to 8D The lighting system 100d in this embodiment and Figures 1A to 1D The illumination system 100d is similar to that of the first dichroic mirror 410, but the main differences are as follows. In the illumination system 100d of this embodiment, the first wavelength range W1 reflected by the first dichroic mirror 410 is, for example, between 583-636 nm, and the second wavelength range W2 reflected by the second dichroic mirror 420 is, for example, between 491-582 nm. Therefore, the first color light 411 generated by filtering through the first dichroic mirror 410 is red, and the second color light 421 generated by filtering through the second dichroic mirror 420 is green. When the fourth laser beam 241 is red, during the R time period, the fourth laser module 240 can be turned on simultaneously with the first laser module 210, so that the red fourth laser beam 241 and the red first color light 411 are mixed to form a red beam that is less likely to cause laser speckle. In this embodiment, the wavelength conversion region 312 of the first wavelength conversion element 310 and the wavelength conversion region 322 of the second wavelength conversion element 320 may contain the same or different phosphors, which is not limited here. For example, the wavelength conversion region 312 of the first wavelength conversion element 310 contains yellow phosphor, and the wavelength conversion region 322 of the second wavelength conversion element 320 contains green phosphor.

[0045] Figure 9 This is a simplified three-dimensional schematic diagram illustrating the optical path positional relationship between the third laser module and the light-diffusing module in a lighting system according to another embodiment of the present invention. The lighting system of this embodiment... Figures 1A to 1D The lighting system is similar to that of the other system, but the main differences are as follows. In this embodiment, the transmission path of the third laser beam 231 from the third laser module 230 to the uniform light module 110 is not on the same plane. In other words, the volume occupied by the optical path can be reduced by rotation and translation. Similarly, the optical paths corresponding to the first laser module 210, the second laser module 220, and the fourth laser module 240 can also be designed with rotation and translation similar to those of the optical path of the third laser module 230 described above.

[0046] Figure 10 This is a schematic diagram of the beam timing of a projection device according to another embodiment of the present invention. Please refer to... Figure 10 and Figures 1A to 1D The lighting system of the projection device in this embodiment and Figures 1A to 1D The lighting system is similar to that of the other system, and its beam timing diagram is also similar. Figure 5The timing diagrams for the laser beams are similar, but the main differences are as follows. In the lighting system of this embodiment, the fourth laser beam 241 is green. Since the color of the fourth laser beam 241 is the same as the color of the first color light 411, the time period during which the fourth laser module 240 provides the fourth laser beam 241 is the same as the time period during which the first laser module 210 provides the first laser beam 211. This allows the green first color light 411 and the green fourth laser beam 241 to mix into a green beam that reduces laser speckle. Furthermore, in this embodiment, the first beam splitter 410 has high transmittance within the narrow wavelength distribution range corresponding to the fourth laser beam 241, while having high reflectance in the green light wavelength range outside this narrow wavelength distribution range. Thus, the first beam splitter 410 can still reflect the relatively pure green first color light 411, while allowing the fourth laser beam 241 to pass through.

[0047] Figure 11 This is a schematic diagram of the optical path of the lighting system according to another embodiment of the present invention when the third color light is transmitted to the uniform light module. Figure 12 To adopt Figure 11 A beam timing diagram of the projection device in the lighting system. Please refer to... Figure 11 and Figure 12 The lighting system 100e of the projection device in this embodiment and Figures 1A to 1D The lighting system 100 is similar, and its beam timing diagram is also similar. Figure 5 The beam timing diagrams are similar, but the main differences are as follows. In the lighting system 100e of this embodiment, the fourth laser module 240e includes a first-color laser module 242 and a second-color laser module 244. The first-color laser module 242 provides a first-color laser beam 243, and the second-color laser module 244 provides a second-color laser beam 245. The first-color laser beam 243 and the second-color laser beam 245 sequentially pass through the second dichroic mirror 420 and the first dichroic mirror 410 and are incident on the homogenizing module 110. The color of the first-color laser beam 243 is the same as the color of the first-color light 411, and the color of the second-color laser beam 245 is the same as the color of the second-color light 421. In this embodiment, the time period during which the first-color laser module 242 provides the first-color laser beam 243 overlaps with the time period during which the first laser module 210 provides the first laser beam 211, and the time period during which the second-color laser module 244 provides the second-color laser beam 245 overlaps with the time period during which the second laser module 220 provides the second laser beam 221.

[0048] In this embodiment, the fourth laser module 240e includes a dichroic mirror 246, disposed on the transmission path of the first-color laser beam 243 and the second-color laser beam 245, and used to transmit the first-color laser beam 243 and the second-color laser beam 245 to the third dichroic mirror 430. The dichroic mirror 246 is used to reflect one of the first-color laser beam 243 and the second-color laser beam 245, and to allow the other of the first-color laser beam 243 and the second-color laser beam 245 to pass through. Figure 11 In one embodiment, the dichroic mirror 246 is used to reflect the second color laser beam 245 and to allow the first color laser beam 243 to pass through.

[0049] Figure 13 This is a simplified schematic diagram of the optical path of a lighting system according to another embodiment of the present invention. Please refer to... Figure 13 The present invention does not limit the first dichroic mirror 410 to allow the first laser beam 211 to pass through, filter the first wavelength conversion beam 311 into first color light 411, and reflect the first color light 411 to the light homogenizing module 110. In another embodiment, the first dichroic mirror 410 may also reflect the first laser beam 211, filter the first wavelength conversion beam 311 into first color light 411, and allow the first color light 411 to pass through and be transmitted to the light homogenizing module 110. The present invention does not limit the second dichroic mirror 420 to allow the second laser beam 221 to pass through, filter the second wavelength conversion beam 321 into second color light 421, and reflect the second color light 421 to the light homogenizing module 110. In another embodiment, the second dichroic mirror 420 may also reflect the second laser beam 221, filter the second wavelength conversion beam 321 into second color light 421, and allow the second color light 421 to pass through and be transmitted to the light homogenizing module 110. This invention does not limit the third dichroic mirror 430 to reflecting the third laser beam 231 while allowing the fourth laser beam 241 to pass through. In another embodiment, the third dichroic mirror 430 may also allow the third laser beam 231 to pass through while reflecting the fourth laser beam 241. Figure 13 In one embodiment, the first dichroic mirror 410 allows the first laser beam 211 to pass through, filters the first wavelength conversion beam 311 into the first color light 411, and reflects the first color light 411 to the light homogenizing module 110; the second dichroic mirror 420 reflects the second laser beam 221, filters the second wavelength conversion beam 321 into the second color light 421, and allows the second color light 421 to pass through and be transmitted to the light homogenizing module 110; the third dichroic mirror 430 allows the third laser beam 231 to pass through, and reflects the fourth laser beam 241.

[0050] In summary, the lighting system and projection device of the embodiments of the present invention have at least one of the following advantages: In the lighting system and projection device of the embodiments of the present invention, a first laser module, a first wavelength conversion element, and a first dichroic mirror are used to generate a first color light, and a second laser module, a second wavelength conversion element, and a second dichroic mirror are used to generate a second color light. Therefore, the first color light, the second color light, and the third laser beam can be independently turned on and off, without being limited by hardware limitations such as motors or color wheels, which can significantly improve the color refresh rate without color distortion. Furthermore, in the lighting system and projection device of the embodiments of the present invention, the color of the fourth laser beam is the same as the color of the first color light or the second color light. The first color light and the second color light are converted by the wavelength conversion element and filtered by the first dichroic mirror and the second dichroic mirror, respectively, without laser speckle. Therefore, by combining the first color light with the fourth laser beam or the second color light with the fourth laser beam, speckle can be effectively suppressed. Furthermore, the first color light filtered by the first dichroic mirror and the second color light filtered by the second dichroic mirror can have high color purity, thus effectively improving the color gamut coverage.

[0051] The above description is merely a preferred embodiment of the present invention and should not be construed as limiting the scope of the invention. Any simple equivalent changes and modifications made in accordance with the claims and description of the invention are still within the scope of this patent. Furthermore, no embodiment or claim of the present invention needs to achieve all the objectives, advantages, or features disclosed in the invention. In addition, the abstract and title are only used to assist in patent document retrieval and are not intended to limit the scope of the invention. Moreover, the terms "first," "second," etc., mentioned in this specification or claims are only used to name elements or distinguish different embodiments or scopes, and are not used to limit the upper or lower limit of the number of elements.

Claims

1. A lighting system, characterized in that, The lighting system includes a light source module, a wavelength conversion module, a beam splitting module, and a light homogenizing module, wherein: The light source module includes a first laser module, a second laser module, a third laser module, and a fourth laser module, wherein the first laser module, the second laser module, the third laser module, and the fourth laser module respectively provide a first laser beam, a second laser beam, a third laser beam, and a fourth laser beam; The wavelength conversion module includes a first wavelength conversion element and a second wavelength conversion element. The first wavelength conversion element is disposed on the transmission path of the first laser beam and is used to convert the first laser beam into a first wavelength conversion beam. The second wavelength conversion element is disposed on the transmission path of the second laser beam and is used to convert the second laser beam into a second wavelength conversion beam. The beam splitting module includes a first dichroic mirror, a second dichroic mirror, and a third dichroic mirror. The first dichroic mirror is disposed on the transmission path of the first laser beam from the first laser module to the first wavelength conversion element, so as to allow one of the light in the first wavelength range and the light outside the first wavelength range to be reflected and the other to pass through. The second dichroic mirror is disposed on the transmission path of the second laser beam from the second laser module to the second wavelength conversion element, so as to allow one of the light in the second wavelength range and the other to be reflected and the other to pass through. The third dichroic mirror is disposed on the transmission path of the third laser beam and the fourth laser beam, so as to transmit the third laser beam and the fourth laser beam to the second dichroic mirror. The first wavelength conversion beam is filtered by the first dichroic mirror to become a first color light with the first wavelength range. The first dichroic mirror guides the first color light to be incident on the homogenizing module. The second wavelength conversion beam is filtered by the second dichroic mirror to become a second color light with the second wavelength range. The second dichroic mirror guides the second color light to be incident on the homogenizing module. The third laser beam and the fourth laser beam are sequentially incident on the homogenizing module through the guidance of the second dichroic mirror and the first dichroic mirror. The color of the fourth laser beam is the same as the color of the first color light or the second color light. The homogenizing module homogenizes the first color light, the second color light, the third laser beam and the fourth laser beam to generate an illumination beam.

2. The lighting system according to claim 1, characterized in that, The third laser module and the fourth laser module are both located on the same side of the second dichroic mirror.

3. The lighting system according to claim 1, characterized in that, The first laser beam, the second laser beam, and the third laser beam have the same center wavelength.

4. The lighting system according to claim 1, characterized in that, The first wavelength range is between 491-582nm, and the second wavelength range is between 583-636nm.

5. The lighting system according to claim 1, characterized in that, The third dichroic mirror is used to reflect the third laser beam from the third laser module and allow the fourth laser beam from the fourth laser module to pass through.

6. The lighting system according to claim 5, characterized in that, The third dichroic mirror is used to reflect wavelengths between 435-485nm, and the center wavelength of the fourth laser beam is greater than 636nm.

7. The lighting system according to claim 1, characterized in that, The third dichroic mirror is used to reflect the fourth laser beam from the fourth laser module and allow the third laser beam from the third laser module to pass through.

8. The lighting system according to claim 1, characterized in that, The first laser module, the second laser module, and the third laser module are respectively used to provide the first laser beam, the second laser beam, and the third laser beam at different times.

9. The lighting system according to claim 1, characterized in that, The time period during which the fourth laser module provides the fourth laser beam partially overlaps with the time period during which the first laser module and the second laser module simultaneously provide the first laser beam and the second laser beam, such that the fourth laser beam, the first color light, and the second color light combine to form the third color light.

10. The lighting system according to claim 1, characterized in that, The time period during which the third laser module provides the third laser beam partially overlaps with the time period during which the first laser module provides the first laser beam or the second laser module provides the second laser beam, thereby combining the third laser beam with the first color light or the third laser beam with the second color light to form a fourth color light.

11. The lighting system according to claim 1, characterized in that, The overlap range of the spectra of the first color light and the second color light is less than 15% of the range of the spectra of the first color light and the second color light, respectively.

12. The lighting system according to claim 1, characterized in that, The fourth laser beam has a transmittance of more than 90% in both the first and second dichroic mirrors.

13. The lighting system according to claim 1, characterized in that, The excitation spectrum of the wavelength conversion region of the first wavelength conversion element is different from the excitation spectrum of the wavelength conversion region of the second wavelength conversion element.

14. The lighting system according to claim 1, characterized in that, The wavelength conversion regions of the first wavelength conversion element and the second wavelength conversion element are both annular.

15. The lighting system according to claim 14, characterized in that, The first wavelength conversion element and the second wavelength conversion element are disposed on the same rotating substrate, and the distance from the first wavelength conversion element to the central axis of the rotating substrate is not equal to the distance from the second wavelength conversion element to the central axis of the rotating substrate.

16. The lighting system according to claim 15, characterized in that, The wavelength conversion region of the first wavelength conversion element is radially farther from the central axis, the wavelength conversion region of the second wavelength conversion element is radially closer to the central axis, and the distance between the spot generated by the first laser beam on the first wavelength conversion element and the spot generated by the second laser beam on the second wavelength conversion element is greater than the diameter of the second wavelength conversion element.

17. The lighting system according to claim 1, characterized in that, The line connecting the central axis of the first wavelength conversion element and the central axis of the second wavelength conversion element is defined as the first line, and the line connecting the light spot generated by the first laser beam on the first wavelength conversion element and the light spot generated by the second laser beam on the second wavelength conversion element is defined as the second line, and the angle between the first line and the second line is not zero.

18. The lighting system according to claim 1, characterized in that, The transmission path of the third laser beam from the third laser module to the uniform light module is not on the same plane.

19. The lighting system according to claim 1, characterized in that, The fourth laser module includes a first-color laser module and a second-color laser module. The first-color laser module is used to provide a first-color laser beam, and the second-color laser module is used to provide a second-color laser beam. The first-color laser beam and the second-color laser beam pass through the second dichroic mirror and the first dichroic mirror in sequence and are incident on the light homogenizing module. The color of the first-color laser beam is the same as the color of the first-color light, and the color of the second-color laser beam is the same as the color of the second-color light.

20. A projection device, characterized in that, The projection device includes an illumination system, a light valve module, and a lens module, wherein: The lighting system is used to provide a beam of light; The light valve module is configured on the transmission path of the illumination beam and is used to convert the illumination beam into an image beam; and The lens module is positioned on the transmission path of the image beam and is used to project the image beam outside the projection device; The lighting system includes a light source module, a wavelength conversion module, a beam splitting module, and a light homogenizing module, wherein: The light source module includes a first laser module, a second laser module, a third laser module, and a fourth laser module, wherein the first laser module, the second laser module, the third laser module, and the fourth laser module respectively provide a first laser beam, a second laser beam, a third laser beam, and a fourth laser beam; The wavelength conversion module includes a first wavelength conversion element and a second wavelength conversion element. The first wavelength conversion element is disposed on the transmission path of the first laser beam and is used to convert the first laser beam into a first wavelength conversion beam. The second wavelength conversion element is disposed on the transmission path of the second laser beam and is used to convert the second laser beam into a second wavelength conversion beam. The beam splitting module includes a first dichroic mirror, a second dichroic mirror, and a third dichroic mirror. The first dichroic mirror is disposed on the transmission path of the first laser beam from the first laser module to the first wavelength conversion element, so as to allow one of the light in the first wavelength range and the light outside the first wavelength range to be reflected and the other to pass through. The second dichroic mirror is disposed on the transmission path of the second laser beam from the second laser module to the second wavelength conversion element, so as to allow one of the light in the second wavelength range and the other to be reflected and the other to pass through. The third dichroic mirror is disposed on the transmission path of the third laser beam and the fourth laser beam, so as to transmit the third laser beam and the fourth laser beam to the second dichroic mirror. In this process, the first wavelength-converted beam is filtered by the first dichroic mirror to become a first color light with the first wavelength range, and the first dichroic mirror guides the first color light to be incident on the homogenizing module. The second wavelength-converted beam is filtered by the second dichroic mirror to become a second color light with the second wavelength range, and the second dichroic mirror guides the second color light to be incident on the homogenizing module. The third laser beam and the fourth laser beam are sequentially incident on the homogenizing module through the guidance of the second dichroic mirror and the first dichroic mirror. The color of the fourth laser beam is the same as the color of the first color light or the second color light. The homogenizing module homogenizes the first color light, the second color light, the third laser beam, and the fourth laser beam to generate the illumination beam.

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