Illumination system and projection device

Abstract

A lighting system is disclosed. The projection device comprises an illumination system. The lighting system comprises a light source module and a first dichroic mirror. The light source module comprises a first light source and a second light source. The first light source and the second light source respectively provide first color light, second color light and third color light. The first dichroic mirror is arranged on a transmission path of the first color light, the second color light and the third color light, the first dichroic mirror enables the first color light and the second color light to be transmitted along a first direction and enables the third color light to be transmitted along a second direction, and the first direction is perpendicular to the second direction. The volume of the projection device is reduced, and the color of the projection picture is enhanced.

Description

Technical Field

[0001] The present invention relates to an optical system and optical device, and more particularly to an illumination system and a projection device using the illumination system. Background Technology

[0002] A projection device is a display device used to generate large-area images, and it continues to advance with technological development and innovation. The imaging principle of a projection device is to convert the illumination beam generated by the lighting system into an image beam via a light valve, and then project the image beam through a projection lens onto the target object (e.g., a screen or wall) to form a projected image. To achieve color display effects, the lighting system can utilize laser diodes (or light-emitting diodes) of different colors or monochromatic (e.g., blue light) lasers in conjunction with wavelength conversion elements as the illumination source.

[0003] Generally, the optical components in a projection device are arranged on the same horizontal plane (e.g., the bottom of the casing). Therefore, they occupy a significant amount of space horizontally. To reduce this horizontal footprint, some current projection devices configure certain optical components (e.g., wavelength conversion elements) at different heights. However, guiding the light beam to these different optical components requires additional mirrors, making it difficult to reduce the overall size of the projection device and increasing its cost.

[0004] 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

[0005] This invention provides a lighting system and a projection device that occupy a smaller space and enhances the color saturation of the projected image. Furthermore, the wavelength conversion wheel of the projection device improves stability and reduces vibration and noise during rotation.

[0006] Other objects and advantages of the present invention can be further understood from the technical features disclosed herein.

[0007] To achieve one, some, or all of the above-mentioned objectives, or other objectives, one embodiment of the present invention provides a lighting system. The lighting system includes: a light source module and a first dichroic mirror. The light source module includes a first light source and a second light source, which are respectively used to provide a first color light, a second color light, and a third color light. The first dichroic mirror is disposed on the transmission path of the first color light, the second color light, and the third color light. The first dichroic mirror is used to allow the first color light and the second color light to be transmitted along a first direction, and to allow the third color light to be transmitted along a second direction, wherein the first direction is perpendicular to the second direction.

[0008] To achieve one or more of the above-mentioned objectives, or other objectives, one embodiment of the present invention provides a projection device. The projection device includes an illumination system, a light valve, and a projection lens. The illumination system provides an illumination beam. The light valve is disposed in the transmission path of the illumination beam and is used to convert the illumination beam into an image beam. The projection lens is disposed in the transmission path of the image beam and is used to project the image beam out of the projection device. The illumination system includes a light source module and a first dichroic mirror. The light source module includes a first light source and a second light source, which respectively provide a first color light, a second color light, and a third color light. The first dichroic mirror is disposed in the transmission path of the first, second, and third color lights, and is used to allow the first and second color lights to transmit along a first direction, and to allow the third color light to transmit along a second direction, wherein the first direction is perpendicular to the second direction.

[0009] Based on the above, in the lighting system and projection device of the embodiments of the present invention, the first and second colored lights of the light source module are transmitted along a first direction perpendicular to the direction of gravity after leaving the first dichroic mirror, while the third colored light of the light source module is transmitted along the opposite direction of gravity (the second direction) after leaving the first dichroic mirror. The third colored light is then transmitted to the wavelength conversion wheel via the second dichroic mirror after leaving the first dichroic mirror. Through the arrangement of the first dichroic mirror, the third colored light can be transmitted along the direction of gravity. Therefore, the multiple optical elements arranged along the optical path of the third colored light between the first dichroic mirror and the wavelength conversion wheel can be respectively arranged at different positions along the direction of gravity, which helps to reduce the overall size of the lighting system and projection device.

[0010] To make the above features and advantages of the present invention more apparent and understandable, specific embodiments are described below in conjunction with the accompanying drawings. Attached Figure Description

[0011] Figure 1 This is a top view schematic diagram of a projection device according to an embodiment of the present invention.

[0012] Figure 2 yes Figure 1 A side view of a portion of the projection device.

[0013] Figure 3 yes Figure 2 An enlarged schematic diagram of the first dichroic mirror and the light source module.

[0014] Figure 4 yes Figure 2 A schematic diagram of the light emission sequence of different colors of light from the light source module within a frame cycle.

[0015] Figure 5A and Figure 5B yes Figure 1 and Figure 2 A schematic diagram of a medium-wavelength conversion wheel.

[0016] Figure 6 yes Figure 1 The transmittance distribution of the fourth dichroic mirror as a function of wavelength.

[0017] Figure 7 yes Figure 1 A side view of the light valve.

[0018] Explanation of reference numerals in the attached figures:

[0019] 10: Projection device

[0020] 50: Casing

[0021] 50bs: Bottom surface of the shell

[0022] 100: Lighting System

[0023] 110: Light source module

[0024] 111~113: Primary color light source to secondary color light source

[0025] 121-126: First reflecting mirror to sixth reflecting mirror

[0026] 128: Guiding Mirror

[0027] 131-134: First dichroic mirror to fourth dichroic mirror

[0028] 140: Wavelength Conversion Wheel

[0029] 142: Reflective layer

[0030] 144: Wavelength conversion layer

[0031] 143: Mirror reflector

[0032] 145: Substrate

[0033] 145op: Opening

[0034] 145s: Surface

[0035] 171: First homogenizing element

[0036] 172: Second homogenizing element

[0037] 191-199: Lenses

[0038] 200: Prism Group

[0039] 210, 220: Prisms

[0040] 300: Light valve

[0041] 400: Projection lens

[0042] A1: First Area

[0043] A2: Second Area

[0044] FP: Frame Cycle

[0045] GD: Direction of gravity

[0046] IL: Illumination beam

[0047] IML: Image Beam

[0048] L1~L4: First color light~Fourth color light

[0049] LS1: First Light Source

[0050] LS2: Second light source

[0051] RA: Reflection Zone

[0052] RX: Spindle

[0053] T_Int1, T_Int2, T_Int3, T_Int4: Time intervals

[0054] WCA: Wavelength Conversion Region

[0055] X, Y, Z: Direction. Detailed Implementation

[0056] 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.

[0057] Figure 1 This is a top view schematic diagram of a projection device according to an embodiment of the present invention. Figure 2 yes Figure 1 A side view of a portion of the projection device. Figure 3 yes Figure 2An enlarged schematic diagram of the first dichroic mirror and the light source module. Figure 4 yes Figure 2 A schematic diagram showing the timing of light emission of different colors from the light source module within a frame period. Figure 5A and Figure 5B yes Figure 1 and Figure 2 A schematic diagram of a medium-wavelength conversion wheel. Figure 6 yes Figure 1 The transmittance distribution of the fourth dichroic mirror as a function of wavelength. For clarity, Figure 1 Omitted Figure 2 Illustration of intermediate lens 193 and lens 194.

[0058] Please refer to Figure 1 and Figure 2 The projection device 10 includes a housing 50 and an illumination system 100. The illumination system 100 is disposed within the housing 50. The illumination system 100 provides an illumination beam IL and includes a light source module 110 and a first dichroic mirror 131. The light source module 110 provides a first colored light L1, a second colored light L2, and a third colored light L3. The first dichroic mirror 131 is disposed on the transmission path of the first colored light L1, the second colored light L2, and the third colored light L3 from the light source module 110.

[0059] In this embodiment, the first color light L1 is, for example, red light, the second color light L2 is, for example, green light, and the third color light L3 is, for example, blue light, but is not limited thereto. For example, the light source module 110 includes a first light source LS1 and a second light source LS2. The first light source LS1 and the second light source LS2 may each include a first color light source 111 for providing the first color light L1, a second color light source 112 for providing the second color light L2, and a third color light source 113 for providing the third color light L3. In this embodiment, the first color light source 111, the second color light source 112, and the third color light source 113 are each, for example, laser diodes (LDs), but are not limited thereto. In other embodiments, the color light sources of the light source module may be light-emitting diodes (LEDs).

[0060] It should be noted that in this embodiment, the number of each of the first color light source 111, the second color light source 112, and the third color light source 113 is illustrated by two, one, and one respectively, and does not imply that the invention is limited to this. In other embodiments, the number of color light sources of different colors can be adjusted according to different application requirements or optical designs. In this embodiment, the third color light source 113 is positioned between the first color light source 111 and the second color light source 112, so that the third color light L3 of the third color light source 113 can be concentrated on the central area of ​​the first dichroic mirror 131.

[0061] Please refer to Figure 2 and Figure 3 In this embodiment, the arrangement plane of the first color light source 111, the second color light source 112, and the third color light source 113 of the first light source LS1 can be parallel to the direction of gravity GD, while the arrangement plane of the first color light source 111, the second color light source 112, and the third color light source 113 of the second light source LS2 can be perpendicular to the direction of gravity GD. Furthermore, the housing 50 has a bottom surface 50bs, which is perpendicular to the direction of gravity GD. That is, the arrangement plane of the first color light source 111, the second color light source 112, and the third color light source 113 of the first light source LS1 can be perpendicular to the bottom surface 50bs, while the arrangement plane of the first color light source 111, the second color light source 112, and the third color light source 113 of the second light source LS2 can be parallel to the bottom surface 50bs. The first color light L1, the second color light L2, and the third color light L3 emitted by the first light source LS1 are incident on the first dichroic mirror 131 along a first direction (e.g., the X direction) perpendicular to the direction of gravity GD. The first color light L1, the second color light L2, and the third color light L3 emitted by the second light source LS2 are incident on the first dichroic mirror 131 along the opposite direction of the gravitational direction GD (e.g., the Z direction, which is the second direction). The first direction is the X direction, the second direction is the Z direction, and the third direction is the Y direction.

[0062] More specifically, the first color light L1 and the second color light L2 of the light source module 110 are transmitted along a first direction (e.g., the X direction) perpendicular to the direction of gravity GD after leaving the first dichroic mirror 131, while the third color light L3 of the light source module 110 is transmitted along the opposite direction of gravity GD (e.g., the Z direction) after leaving the first dichroic mirror 131. That is, the first dichroic mirror 131 allows the first color light L1 and the second color light L2 to be transmitted along the first direction (X direction), and allows the third color light L3 to be transmitted along the second direction (Z direction), with the first direction being perpendicular to the second direction.

[0063] In this embodiment, the first dichroic mirror 131 has a first region A1 and a second region A2. The first region A1 is configured to correspond to the second color light source 112 and the third color light source 113 of the first light source LS1 and the first color light source 111 of the second light source LS2. The second region A2 is configured to correspond to the first color light source 111 of the first light source LS1 and the second color light source 112 and the third color light source 113 of the second light source LS2. It should be noted that the first region A1 is adapted to allow the second color light L2 from the first light source LS1 to pass through and reflect the third color light L3 from the first light source LS1 and reflect the first color light L1 from the second light source LS2. The second region A2 is adapted to allow the first color light L1 from the first light source LS1 and the third color light L3 from the second light source LS2 to pass through and reflect the second color light L2 from the second light source LS2. In detail, the first color light L1 is red light, the second color light L2 is green light, and the third color light L3 is blue light. The first region A1 of the first dichroic mirror 131 allows green light to pass through and allows red light and blue light to be reflected. The second region A2 of the first dichroic mirror 131 allows red and blue light to pass through, while reflecting green light. It is worth mentioning that the first dichroic mirror 131 allows the first color light L1 and the second color light L2 to travel along the first direction (X direction), and allows the third color light L3 to travel along the opposite direction of gravity GD (Z direction).

[0064] The lighting system 100 also includes a second dichroic mirror 132 and a wavelength conversion wheel 140. The second dichroic mirror 132 is positioned on the transmission path of the third color light L3 from the light source module 110. The wavelength conversion wheel 140 is positioned on the transmission path of the third color light L3 from the second dichroic mirror 132. Please refer to... Figure 2 , Figure 5A and Figure 5B The wavelength conversion wheel 140 includes a substrate 145, and the substrate 145 is provided with a wavelength conversion region WCA and a reflection region RA. The wavelength conversion region WCA is provided on the surface 145s of the substrate 145. The motor drives the substrate 145 to rotate the wavelength conversion region WCA and the reflection region RA around the rotation axis RX, so that the wavelength conversion region WCA converts the third color light L3 into the fourth color light L4 and reflects the fourth color light L4 to the second dichroic mirror 132 in one time interval (first time interval), and causes the reflection region RA to reflect the third color light L3 to the second dichroic mirror 132 in another time interval (second time interval). The second dichroic mirror 132 is adapted to allow the third color light L3 to pass through and reflect the fourth color light L4. In this embodiment, the fourth color light L4 is, for example, yellow light, but is not limited to this.

[0065] In this embodiment, the wavelength conversion wheel 140 may further include a reflective layer 142 and a wavelength conversion layer 144 sequentially stacked on the surface 145s. The wavelength conversion layer 144 defines a wavelength conversion region WCA and is used to convert the third color light L3 into the fourth color light L4. The reflective layer 142 is, for example, a white diffuse reflection layer, used to diffusely reflect the fourth color light L4 to the second dichroic mirror 132. The surface 145s is defined as the incident surface of the substrate 145 facing the third color light L3. It should be noted that in the normal direction (e.g., the Z direction) of the surface 145s, the substrate 145 has an opening 145op, and a specular reflector 143 is disposed within the opening 145op of the substrate 145. The specular reflector 143 defines a reflection region RA. The specular reflector 143 is used to reflect the third color light L3 to the second dichroic mirror 132. More specifically, the wavelength conversion layer 144 generates a fourth color light L4 after being excited by the third color light L3. The fourth color light L4 can be reflected by the reflective layer 142 and passed through the wavelength conversion layer 144 to be transmitted to the second dichroic mirror 132.

[0066] Please refer to Figures 2 to 4 Within one frame period (FP) of the projection device 10, the light emission of the light source module 110 of the illumination system 100 can be divided into four time intervals. For example, the first color light source 111 is enabled to emit first color light L1 (e.g., red light) in time intervals T_Int1 and T_Int4, and is disabled in the other time intervals. The second color light source 112 is enabled to emit second color light L2 (e.g., green light) in time intervals T_Int2 and T_Int4, and is disabled in the other time intervals. The third color light source 113 is enabled to emit third color light L3 (e.g., blue light) in all four time intervals T_Int1 to T_Int4. In the four time intervals T_Int1 to T_Int4, the illumination beam IL includes at least one of red light, green light, blue light, and yellow light.

[0067] From another perspective, within the time interval T_Int1, in addition to emitting the first color light L1, the light source module 110 also emits the third color light L3 to the wavelength conversion region WCA of the wavelength conversion wheel 140 to excite the fourth color light L4 (e.g., yellow light). Within the time interval T_Int2, in addition to emitting the second color light L2, the light source module 110 also emits the third color light L3 to the wavelength conversion region WCA of the wavelength conversion wheel 140 to excite the fourth color light L4. Within the time interval T_Int3, the light source module 110 only emits the third color light L3, and the third color light L3 is incident on the reflection region RA of the wavelength conversion wheel 140 via the second dichroic mirror 132. Within the time interval T_Int4, the light source module 110 simultaneously emits the first color light L1, the second color light L2, and the third color light L3, and the third color light L3 is incident on the wavelength conversion region WCA of the wavelength conversion wheel 140 via the second dichroic mirror 132 to excite the fourth color light L4.

[0068] In other words, the lighting system 100 emits both the first color light L1 and the fourth color light L4 simultaneously within the time interval T_Int1. Within the time interval T_Int2, the lighting system 100 emits both the second color light L2 and the fourth color light L4 simultaneously. Within the time interval T_Int3, the lighting system 100 emits the third color light L3 simultaneously. Within the time interval T_Int4, the lighting system 100 emits both the first color light L1, the second color light L2, and the fourth color light L4 simultaneously. More specifically, within the time intervals T_Int1, T_Int2, and T_Int4, the fourth color light L4 serves as a supplementary color light to the first color light L1 and the second color light L2 to achieve the desired color saturation of the projected image.

[0069] However, the present invention is not limited thereto. In other embodiments, the first color light source 111 and the second color light source 112 can be enabled to emit the first color light L1 and the second color light L2 simultaneously in time intervals T_Int1, T_Int2 and T_Int4, and are disabled only in time interval T_Int3.

[0070] Please refer to Figure 1 and Figure 2Specifically, the housing 50 has a bottom surface 50bs for supporting the weight of the lighting system 100, and the surface 145s of the substrate 145 of the wavelength conversion wheel 140 is parallel to the bottom surface 50bs of the housing 50. More specifically, the rotation axis RX of the substrate 145 is parallel to the direction of gravity GD (the -Z direction). That is, the surface 145s of the substrate 145 is perpendicular to the direction of gravity GD. Since the surface 145s of the substrate 145 is parallel to the bottom surface 50bs of the housing 50 of the projection device 10, the stability of the wavelength conversion wheel 140 during rotation is improved, which helps to reduce vibration and noise generated during rotation. Therefore, the stability of the light travel path of the lighting system 100 can be significantly improved.

[0071] First, it should be noted that, through the setting of the first dichroic mirror 131, the third color light L3 can be transmitted in the direction of gravity GD. Therefore, the multiple optical elements set in the optical path of the third color light L3 between the first dichroic mirror 131 and the wavelength conversion wheel 140 can be respectively set at different positions along the direction of gravity GD, which helps to reduce the overall size of the lighting system 100 and the projection device 10.

[0072] For example, the lighting system 100 may further include a first reflector 121, a second reflector 122, and a third reflector 123, respectively disposed on the transmission path of the third color light L3 from the first dichroic mirror 131. The third color light L3 originates from the first dichroic mirror 131 and travels along the direction opposite to the gravitational direction GD (e.g., the Z direction). After being reflected by the first reflector 121, it is transmitted to the second reflector 122 along a third direction perpendicular to the gravitational direction GD (e.g., the Y direction). After being reflected by the second reflector 122, the third color light L3 is transmitted along the first direction (X direction) to the third reflector 123, and after being reflected by the third reflector 123, it is transmitted along the gravitational direction GD (-Z direction, the opposite direction of the second direction) to the second dichroic mirror 132.

[0073] The lighting system 100 may further include a third dichroic mirror 133 and a fourth reflector 124. The third dichroic mirror 133 is positioned on the transmission path of the first colored light L1 and the second colored light L2 from the first dichroic mirror 131, and the third colored light L3 from the second dichroic mirror 132. The fourth reflector 124 is positioned on the transmission path of the third colored light L3 from the second dichroic mirror 132. The third colored light L3, transmitted from the second dichroic mirror 132 in the opposite direction (e.g., the Z direction) of gravity direction GD, is reflected by the fourth reflector 124 and then transmitted to the third dichroic mirror 133 in the opposite direction (-Y direction). In this embodiment, the third dichroic mirror 133 is adapted to allow the first colored light L1 and the second colored light L2 to pass through and reflect the third colored light L3.

[0074] The lighting system 100 may further include a fourth dichroic mirror 134 and a fifth reflector 125. The fourth dichroic mirror 134 is positioned along the transmission path of the first colored light L1, the second colored light L2, and the third colored light L3 from the third dichroic mirror 133, and the fourth colored light L4 from the second dichroic mirror 132. The first colored light L1, the second colored light L2, and the third colored light L3, transmitted from the third dichroic mirror 133 along a first direction (X direction), are reflected by the fifth reflector 125 and then transmitted along a third direction (Y direction) to the fourth dichroic mirror 134. Please refer to... Figure 6 In this embodiment, the fourth dichroic mirror 134 has a transmittance of less than 0.1 for light beams with wavelengths ranging from 425nm to 475nm, 510nm to 530nm, and 630nm to 680nm, and a transmittance close to 1 for light beams with wavelengths ranging from 550nm to 620nm. That is, the fourth dichroic mirror 134 is adapted to allow yellow light (i.e., the fourth color light L4) to pass through and reflect red light (i.e., the first color light L1), green light (i.e., the second color light L2), and blue light (i.e., the third color light L3).

[0075] Please refer to Figure 1 and Figure 2 In this embodiment, the illumination system 100 may further include a first light-diffusing element 171 and a second light-diffusing element 172. The first light-diffusing element 171 is disposed on the transmission path of the first colored light L1, the second colored light L2, and the third colored light L3 from the third dichroic mirror 133, and is located between the third dichroic mirror 133 and the fifth reflector 125. The second light-diffusing element 172 is disposed on the transmission path of the first colored light L1, the second colored light L2, the third colored light L3, and the fourth colored light L4 from the fourth dichroic mirror 134. The first colored light L1, the second colored light L2, the third colored light L3, and the fourth colored light L4 form an illumination beam IL after passing through the second light-diffusing element 172. The illumination beam IL includes at least one of the first colored light L1, the second colored light L2, the third colored light L3, and the fourth colored light L4. The first light-diffusing element 171 and the second light-diffusing element 172 are each, for example, a lens array, an integration rod, or other optical elements with light homogenization effects, but are not limited thereto. In this embodiment, the first homogenizing element 171 is, for example, a lens array. The first homogenizing element 171 is used to disrupt the characteristics of the laser light and solve the problem of laser speckle. The second homogenizing element 172 is used to adjust the light patterns of the first color light L1, the second color light L2, the third color light L3, and the fourth color light L4 to conform to the light incident surface shape (e.g., rectangular) of the light valve 300.

[0076] To reduce the overall size of the projection device 10, the aforementioned multiple optical elements can be respectively disposed in spaces at different distances relative to the bottom surface 50bs of the housing. For example, in this embodiment, the distance between the wavelength conversion wheel 140 and the bottom surface 50bs of the housing is less than the distances between the first reflector 121, the second reflector 122, and the third reflector 123 and the bottom surface 50bs of the housing.

[0077] Through the above configuration, the optical path distance between the light source module 110 and the wavelength conversion wheel 140 and the number of components set on the optical path can be effectively reduced, and the wavelength conversion efficiency of the wavelength conversion wheel 140 for the third color light L3 can be improved.

[0078] In this embodiment, the lighting system 100 may also have multiple lenses in its optical path. For example, lenses 191 and 192 may be provided on the transmission path of the third color light L3 between the light source module 110 and the second reflector 122; lenses 193 and 194 may be provided on the transmission path of the third color light L3 between the second dichroic mirror 132 and the wavelength conversion wheel 140; lens 195 may be provided on the transmission path of the third color light L3 between the fourth reflector 124 and the third dichroic mirror 133; lens 196 may be provided on the transmission path of the fourth color light L4 between the second dichroic mirror 132 and the fourth dichroic mirror 134; and lens 197 may be provided on the transmission path of the first color light L1, the second color light L2, and the third color light L3 between the third dichroic mirror 133 and the fifth reflector 125, but this is not the only possibility.

[0079] On the other hand, a guiding mirror 128 can also be provided on the transmission path of the third color light L3 between the fourth reflecting mirror 124 and the third dichroic mirror 133. Since the distance of the fourth reflecting mirror 124 relative to the bottom surface of the housing 50bs is higher than the distance of the third dichroic mirror 133 relative to the bottom surface of the housing 50bs, the guiding mirror 128 can enable the third color light L3 to be transmitted between optical elements at different heights.

[0080] Furthermore, the projection device 10 also includes a prism group 200, a light valve 300, and a projection lens 400. The prism group 200 is disposed in the transmission path of the illumination beam IL from the illumination system 100 and is used to project the illumination beam IL onto the light valve 300. In this embodiment, the prism group 200 may be a total internal reflection prism group (TIR prism group) composed of two prisms 210 and 220.

[0081] refer to Figure 7A light valve 300 is disposed on the transmission path of the illumination beam IL and is used to convert the illumination beam IL into an image beam IML. In this embodiment, the light valve 300 has a dimming surface parallel to the direction of gravity GD, and the dimming surface 300s is perpendicular to the bottom surface 50bs of the housing. The dimming surface 300s has a first edge 300e1 and a second edge 300e2 that are perpendicular to each other. The first edge 300e1 is parallel to the bottom surface 50bs of the housing. Guided by the prism group 200, the orthographic projection of the illumination beam IL on the dimming surface 300s is not parallel to the first edge 300e1 and the second edge 300e2, and also not perpendicular to the first edge 300e1 and the second edge 300e2.

[0082] The light valve 300 may be a reflective light modulator such as a liquid crystal on silicon panel (LCoS panel) or a digital micro-mirror device (DMD), but is not limited thereto. The detailed steps and implementation methods of the method by which the light valve 300 converts the illumination beam IL from the illumination system 100 into an image beam IML are sufficiently taught, suggested, and explained by those with ordinary knowledge in the relevant art, and therefore will not be elaborated further.

[0083] The projection lens 400 is positioned in the transmission path of the image beam IML and is used to project the image beam IML from the projection device 10 to a projection target (not shown), such as a screen or wall. The projection lens 400 may include, for example, a combination of one or more optical lenses with refractive power, 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, the projection lens 400 may further include an optical reflector to reflect the image beam IML from the light valve 300 onto the projection target. The present invention does not limit the type or form of the projection lens 400.

[0084] For example, in this embodiment, the illumination beam IL may be sequentially provided with lens 198, sixth reflector 126 and lens 199 along the transmission direction on the transmission path between illumination system 100 and prism group 200, but is not limited to this.

[0085] In summary, in the lighting system and projection device of one embodiment of the present invention, the first and second colored lights of the light source module are transmitted along a first direction perpendicular to the direction of gravity after leaving the first dichroic mirror, while the third colored light of the light source module is transmitted along the opposite direction of gravity (the second direction) after leaving the first dichroic mirror. The third colored light is then transmitted to the wavelength conversion wheel via the second dichroic mirror after leaving the first dichroic mirror. The first dichroic mirror allows the first and second colored lights to be transmitted along the first direction, and the third colored light to be transmitted along the second direction, with the first direction perpendicular to the second direction. Therefore, the multiple optical elements arranged along the optical path of the third colored light between the first dichroic mirror and the wavelength conversion wheel can be respectively arranged at different positions along the direction of gravity, which helps to reduce the overall size of the lighting system and projection device. Furthermore, the projection device of the present invention enhances the color saturation of the projected image, and the wavelength conversion wheel of the projection device improves stability and reduces vibration and noise during rotation.

[0086] 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 (invention title) are only used to assist in patent document retrieval and are not intended to limit the scope of the invention. Furthermore, 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 and a first dichroic mirror, wherein: The light source module includes a first light source and a second light source, wherein the first light source and the second light source are respectively used to provide a first color light, a second color light, and a third color light; and The first dichroic mirror is disposed on the transmission path of the first color light, the second color light and the third color light. The first dichroic mirror is used to allow the first color light and the second color light to be transmitted along a first direction and to allow the third color light to be transmitted along a second direction, wherein the first direction is perpendicular to the second direction.

2. The lighting system according to claim 1, characterized in that, The first light source and the second light source each include a first color light source, a second color light source and a third color light source. The first color light source is used to emit the first color light, the second color light source is used to emit the second color light, and the third color light source is used to emit the third color light.

3. The lighting system according to claim 1, characterized in that, The first dichroic mirror has a first region and a second region. The first region is used to allow the second color light from the first light source to pass through and reflect the third color light from the first light source and reflect the first color light from the second light source. The second region is used to allow the first color light from the first light source and the third color light from the second light source to pass through and reflect the second color light from the second light source.

4. The lighting system according to claim 3, characterized in that, The lighting system further includes a second dichroic mirror and a wavelength conversion wheel. The second dichroic mirror is disposed on the transmission path of the third color light from the light source module, and the wavelength conversion wheel is disposed on the transmission path of the third color light from the second dichroic mirror. The wavelength conversion wheel includes a substrate, which has a wavelength conversion area and a reflection area. The wavelength conversion area is disposed on the surface of the substrate. The substrate is used to drive the wavelength conversion area and the reflection area to rotate around a rotating axis, so that the wavelength conversion area converts the third color light into a fourth color light and reflects the fourth color light to the second dichroic mirror in a first time interval, and the reflection area reflects the third color light to the second dichroic mirror in a second time interval. The second dichroic mirror is used to allow the third color light to pass through and reflect the fourth color light.

5. The lighting system according to claim 4, characterized in that, The bottom surface of the housing is used to support the weight of the lighting system, and the surface of the substrate is parallel to the bottom surface of the housing.

6. The lighting system according to claim 4, characterized in that, The axis of rotation is parallel to the direction of gravity.

7. The lighting system according to claim 6, characterized in that, The lighting system further includes a first reflector, a second reflector, and a third reflector, which are disposed on the transmission path of the third color light from the first dichroic mirror. The third color light from the first dichroic mirror and transmitted along the second direction is reflected by the first reflector and transmitted along a third direction perpendicular to the direction of gravity to the second reflector. The third color light is reflected by the second reflector and transmitted along the first direction to the third reflector. The third color light is reflected by the third reflector and transmitted along the direction of gravity to the second dichroic mirror.

8. The lighting system according to claim 7, characterized in that, The lighting system further includes a third dichroic mirror and a fourth reflector. The third dichroic mirror is disposed on the transmission path of the first color light and the second color light from the first dichroic mirror, and the fourth reflector is disposed on the transmission path of the third color light from the second dichroic mirror. The third color light from the second dichroic mirror and transmitted along the second direction is reflected by the fourth reflector and transmitted to the third dichroic mirror in the opposite direction of the third direction. The third dichroic mirror is used to allow the first color light and the second color light to pass through and reflect the third color light.

9. The lighting system according to claim 8, characterized in that, The lighting system further includes a fourth dichroic mirror and a fifth reflector. The fourth dichroic mirror is disposed on the transmission path of the fourth color light from the second dichroic mirror. The first color light, the second color light, and the third color light, which are transmitted from the third dichroic mirror and along the first direction, are reflected by the fifth reflector and then transmitted along the third direction to the fourth dichroic mirror. The fourth dichroic mirror is used to allow the fourth color light to pass through and reflect the first color light, the second color light, and the third color light.

10. The lighting system according to claim 9, characterized in that, The lighting system further includes a first light-diffusing element, which is disposed on the transmission path of the first color light, the second color light and the third color light from the third dichroic mirror, and is located between the third dichroic mirror and the fifth reflector.

11. The lighting system according to claim 10, characterized in that, The lighting system further includes a second light-diffusing element disposed on the transmission path of the first color light, the second color light, the third color light and the fourth color light from the fourth dichroic mirror. The second light-diffusing element allows the first color light, the second color light, the third color light and the fourth color light to pass through.

12. A projection device, characterized in that, The projection device includes an illumination system, a light valve, and a projection lens, wherein: The lighting system is used to provide an illumination beam and includes a light source module and a first dichroic mirror, wherein: The light source module includes a first light source and a second light source, wherein the first light source and the second light source are respectively used to provide a first color light, a second color light, and a third color light; and The first dichroic mirror is disposed on the transmission path of the first color light, the second color light and the third color light. The first dichroic mirror is used to allow the first color light and the second color light to be transmitted along a first direction and to allow the third color light to be transmitted along a second direction. The first direction is perpendicular to the second direction. The light valve is disposed in the transmission path of the illumination beam and is used to convert the illumination beam into an image beam; and The projection lens is positioned on the transmission path of the image beam and is used to project the image beam out of the projection device.

13. The projection device according to claim 12, characterized in that, The first light source and the second light source each include a first color light source, a second color light source and a third color light source. The first color light source is used to emit the first color light, the second color light source is used to emit the second color light, and the third color light source is used to emit the third color light.

14. The projection device according to claim 12, characterized in that, The first dichroic mirror has a first region and a second region. The first region is used to allow the second color light from the first light source to pass through and reflect the third color light from the first light source and reflect the first color light from the second light source. The second region is used to allow the first color light from the first light source and the third color light from the second light source to pass through and reflect the second color light from the second light source.

15. The projection device according to claim 14, characterized in that, The projection device further includes a second dichroic mirror and a wavelength conversion wheel. The second dichroic mirror is disposed on the transmission path of the third color light from the light source module, and the wavelength conversion wheel is disposed on the transmission path of the third color light from the second dichroic mirror. The wavelength conversion wheel includes a substrate, which has a wavelength conversion area and a reflection area. The wavelength conversion area is disposed on the surface of the substrate. The substrate is used to drive the wavelength conversion area and the reflection area to rotate around a rotating axis, so that the wavelength conversion area converts the third color light into a fourth color light and reflects the fourth color light to the second dichroic mirror in a first time interval, and the reflection area reflects the third color light to the second dichroic mirror in a second time interval. The second dichroic mirror is used to allow the third color light to pass through and reflect the fourth color light.

16. The projection device according to claim 15, characterized in that, The projection device further includes a housing, wherein the surface of the substrate is parallel to the bottom surface of the housing, the bottom surface of the housing being used to support the weight of the lighting system.

17. The projection device according to claim 16, characterized in that, The projection device further includes a prism assembly disposed in the transmission path of the illumination beam from the illumination system and used to project the illumination beam onto the light valve.

18. The projection device according to claim 17, characterized in that, The light valve has a dimming surface parallel to the second direction and perpendicular to the bottom surface of the housing. The dimming surface has a first edge and a second edge that are perpendicular to each other. The first edge is parallel to the bottom surface of the housing, and the orthographic projection of the light path of the illumination beam from the prism group onto the dimming surface is not parallel to the first edge and the second edge.

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