Projection device

Abstract

The invention provides a projection device. The projection device comprises a device body, a first heat dissipation piece, a second heat dissipation piece, a third heat dissipation piece and a heat dissipation fan. The device body comprises a light-emitting element, a wavelength conversion element, a light valve and a projection lens. The first heat dissipation piece, the second heat dissipation piece and the third heat dissipation piece are connected to the light-emitting element, the light valve and the wavelength conversion element respectively. The cooling fan is provided with an air outlet face and is suitable for providing cooling airflow. The air outlet face faces at least one of the first heat dissipation piece, the second heat dissipation piece and the third heat dissipation piece, and the first heat dissipation piece, the second heat dissipation piece and the third heat dissipation piece are all located on at least one flowing path of the heat dissipation airflow.

Description

Technical Field

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

[0002] The application of micro-projection devices is becoming more and more extensive. They can be applied to automotive lighting systems and used in conjunction with adaptive driving beam (ADB) technology to project driving information.

[0003] Micro-projection devices generally use a heat dissipation fin group and a heat dissipation fan to dissipate heat from their laser light source, light valve and phosphor wheel. However, the multiple heat dissipation fin groups corresponding to the laser light source, light valve and phosphor wheel usually need to correspond to multiple heat dissipation fans respectively for heat dissipation. This configuration limits the miniaturization design of the micro-projection device.

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

[0005] An object of the present invention is to provide a projection device which can have a smaller volume.

[0006] To achieve the above object, the present invention provides a projection device, comprising: a device body, the device body comprising a light emitting element, a wavelength conversion element, a light valve and a projection lens, wherein the light emitting element is used to emit an illumination beam, the wavelength conversion element is used to convert the wavelength of a part of the illumination beam, the light valve is used to convert the illumination beam from the light emitting element and the wavelength conversion element into an image beam, and the projection lens is used to project the image beam; A first heat sink, a second heat sink and a third heat sink are respectively connected to the light emitting element, the light valve and the wavelength conversion element; and The cooling fan has an air outlet surface and is used to provide a cooling airflow, wherein the air outlet surface faces at least one of the first cooling element, the second cooling element and the third cooling element, and the first cooling element, the second cooling element and the third cooling element are all located on at least one flow path of the cooling airflow.

[0007] Preferably, the air outlet surface faces the first heat sink and the third heat sink, the first heat sink is located between the cooling fan and the second heat sink and has a through hole; the flow path includes three, one of which passes through the first heat sink, another passes through the through hole and the second heat sink in sequence, and another flows through the third heat sink.

[0008] Preferably, the first heat sink comprises a plate body and a heat sink fin group, the plate body has a first opening, the heat sink fin group is disposed on the plate body and has a second opening, the first opening and the second opening are aligned with each other to form the through hole; The projection device also includes: A frame having a guide slope extending from the through hole toward the second heat sink; A first circuit board and a second circuit board, the second heat sink is disposed on the first circuit board, and the frame is located between the first circuit board and the second circuit board to support the second circuit board away from the first circuit board; The frame has a slot, and the guiding slope is formed at the edge of the slot; the second circuit board has at least one heating element, and the at least one flow path passes through the through hole, the space between the first circuit board and the frame, the slot and the at least one heating element in sequence.

[0009] Preferably, the heat dissipation fan has an air inlet surface, and the air inlet surface is perpendicular to the air outlet surface; The air inlet surface faces the second heat sink, the air outlet surface faces the first heat sink, the first heat sink is located between the heat sink fan and the third heat sink, and the at least one flow path passes through the second heat sink, the heat sink fan, the first heat sink and the third heat sink in sequence.

[0010] Preferably, it further comprises a housing, wherein the first heat sink, the second heat sink, the third heat sink and the heat dissipation fan are at least partially accommodated by the housing; The first heat sink faces the heat dissipation fan along a first direction, and the first heat sink faces the third heat sink along a second direction different from the first direction. The at least one flow path passes through the heat dissipation fan and the first heat sink in sequence along the first direction and passes through the first heat sink and the third heat sink in sequence along the second direction. The shell guides the heat dissipation airflow to flow in the first direction and the second direction in sequence.

[0011] Preferably, the first direction is perpendicular to the second direction.

[0012] Preferably, the air outlet surface faces the first heat sink, the second heat sink and the third heat sink; the second heat sink and the third heat sink overlap each other in a vertical direction parallel to the air outlet surface, and the second heat sink and the third heat sink overlap the first heat sink in a horizontal direction parallel to the air outlet surface; The flow paths include three, and the three flow paths pass through the first heat sink, the second heat sink, and the third heat sink respectively.

[0013] Preferably, the air outlet surface faces the second heat sink and the third heat sink, the third heat sink is located between the cooling fan and the first heat sink, and the flow path includes two flow paths, one of which passes through the second heat sink, and the other flow path passes through the third heat sink and the first heat sink in sequence.

[0014] Preferably, along the air outlet direction of the heat dissipation fan, the first heat dissipation element, the second heat dissipation element and the third heat dissipation element all overlap the heat dissipation fan.

[0015] Preferably, the first heat sink has a first contact surface contacting the light emitting element, the second heat sink has a second contact surface contacting the light valve, and the third heat sink has a third contact surface contacting the wavelength conversion element; The first contact surface, the second contact surface and the third contact surface are not parallel to each other, and the angle between any two of the first contact surface, the second contact surface and the third contact surface is between 45 degrees and 135 degrees; or, The first contact surface is parallel to one of the second contact surface and the third contact surface and is not parallel to the other one of the second contact surface and the third contact surface. The angle between the first contact surface and the other one of the second contact surface and the third contact surface is between 45 degrees and 135 degrees.

[0016] Compared with the prior art, the projection device provided by the present invention arranges the first heat sink, the second heat sink and the third heat sink corresponding to the light emitting element, the light valve and the wavelength conversion element respectively so as to be located on the flow path of the heat dissipation airflow provided by a single heat dissipation fan, and the first heat sink, the second heat sink and the third heat sink can be cooled by the single heat dissipation fan. Accordingly, it is not necessary to configure a plurality of heat dissipation fans corresponding to the first heat sink, the second heat sink and the third heat sink respectively, which is conducive to the miniaturization design of the projection device. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic structural diagram of a projection device according to an embodiment of the present invention.

[0018] Figure 2 yes Figure 1 A three-dimensional view of some components of the device body.

[0019] Figures 3 to 5 They are Figure 1 Stereoscopic images of some components of a projection device at different viewing angles.

[0020] Figure 6 Draw Figure 2 A schematic structural diagram of a light emitting element, a light valve and a wavelength conversion element connected to a first heat sink, a second heat sink and a third heat sink respectively.

[0021] Figure 7 FIG. 4 is a side view of some components of a projection device according to another embodiment of the present invention.

[0022] Figure 8 yes Figure 7 A three-dimensional view of some components of the device body.

[0023] Fig. 9 Draw Figure 8 A schematic structural diagram of a light emitting element, a light valve and a wavelength conversion element connected to a first heat sink, a second heat sink and a third heat sink respectively.

[0024] Fig.10 It is a three-dimensional diagram of some components of a projection device according to another embodiment of the present invention.

[0025] Fig.11 yes Fig.10 A three-dimensional view of some components of the device body.

[0026] Fig.12 Draw Fig.11 A schematic structural diagram of a light emitting element, a light valve and a wavelength conversion element connected to a first heat sink, a second heat sink and a third heat sink respectively.

[0027] Fig.13 FIG. 4 is a side view of some components of a projection device according to another embodiment of the present invention.

[0028] Fig.14 yes Fig.13 A three-dimensional view of some components of the device body. Implementation

[0029] In order to provide a further understanding of the purpose, structure, features, and functions of the present invention, the following detailed description is given in conjunction with the embodiments.

[0030] Certain words are used in the specification and claims to refer to specific components. Those with ordinary knowledge in the field should understand that manufacturers may use different terms to refer to the same component. This specification and claims do not use differences in names as a way to distinguish components, but rather use differences in components' functions as the criteria for distinction. The term "including" mentioned throughout the specification and claims is an open-ended term and should be interpreted as "including but not limited to".

[0031] Figure 1 is a schematic diagram of a projection device according to an embodiment of the present invention. Figure 1The projection device 100 of this embodiment includes a device body 110, which includes a light emitting element 112, a wavelength conversion element 114, a light valve 116, and a projection lens 118. The light emitting element 112 is suitable for emitting an illumination beam L1, the wavelength conversion element 114 is suitable for converting the wavelength of a part of the illumination beam L1, the light valve 116 is suitable for converting the illumination beam L1 from the light emitting element 112 and the wavelength conversion element 114 into an image beam L2, and the projection lens 118 is suitable for projecting the image beam L2.

[0032] Figure 2 yes Figure 1 Please refer to Figure 2 Specifically, the device body 110 of this embodiment further includes a light diffusion component 119 and a semi-transmissive semi-reflective element 111. The light emitting element 112 is, for example, a blue laser source, which emits blue light (i.e. Figure 1 A portion of the illumination light beam L1 is reflected by the semi-transmissive and semi-reflective element 111 to the wavelength conversion element 114. The wavelength conversion element 114 is, for example, a fluorescent wheel and is used to convert the received blue light into yellow light and then transmit it to the semi-transmissive and semi-reflective element 111. The yellow light passes through the semi-transmissive and semi-reflective element 111 and is reflected by the reflective element 113 to the light valve 116.

[0033] The blue light (i.e. Figure 1 Another part of the illumination light beam L1) shown in FIG. 1 reaches the light diffusion component 119 through the semi-transmissive semi-reflective element 111, and is diffused by the light diffusion component 119 and then transmitted to the semi-transmissive semi-reflective element 111. The blue light is reflected by the semi-transmissive semi-reflective element 111 and then reflected by the reflective element 113 to the light valve 116. The blue light and the yellow light transmitted to the light valve are combined into white light. The light valve 116 is, for example, a digital micromirror device (DMD) for converting the white light into Figure 1 The image beam L2 is shown and transmitted to the projection lens 118.

[0034] Figures 3 to 5 They are Figure 1 Stereoscopic images of some components of a projection device at different viewing angles. Figure 6 Draw Figure 2 The light emitting element, the light valve and the wavelength conversion element are connected to the first heat sink, the second heat sink and the third heat sink respectively. Figures 3 to 6 The projection device 100 of this embodiment further includes a first heat sink 120, a second heat sink 130, a third heat sink 140 and a heat dissipation fan 150. The first heat sink 120, the second heat sink 130 and the third heat sink 140 are, for example, heat dissipation fin structures and are respectively connected to the light emitting element 112, the light valve 114 and the wavelength conversion element 116.

[0035] Specifically, the first heat sink 120 has a first contact surface 1201 contacting the light emitting element 112, the second heat sink 130 has a second contact surface 1301 contacting the light valve 116, and the third heat sink 140 has a third contact surface 1401 contacting the wavelength conversion element 114. The first contact surface 1201, the second contact surface 1301, and the third contact surface 1401 are not parallel to each other. The angle between any two of the first contact surface 1201, the second contact surface 1301, and the third contact surface 1401 is, for example, between 45 degrees and 135 degrees.

[0036] The cooling fan 150 has an air outlet surface 152 and is suitable for providing cooling airflow. When observed along the air outlet direction F1 of the cooling fan 150, the first heat sink 120, the second heat sink 130 and the third heat sink 140 all overlap the cooling fan 150. The air outlet surface 152 faces the first heat sink 120 and the third heat sink 140, and the first heat sink 120, the second heat sink 130 and the third heat sink 140 are all located on the flow path of the cooling airflow. Specifically, the flow path P1 of the cooling airflow passes through the first heat sink 120, the flow path P2 of the cooling airflow passes through the second heat sink 130, and the flow path P3 of the cooling airflow passes through the third heat sink 140.

[0037] As described above, in this embodiment, the first heat sink 120, the second heat sink 130 and the third heat sink 140 respectively corresponding to the light emitting element 112, the light valve 116 and the wavelength conversion element 114 are arranged to be located on the flow path of the heat dissipation airflow provided by the single heat dissipation fan 150, and the first heat sink 120, the second heat sink 130 and the third heat sink 140 can be cooled by the single heat dissipation fan 150. Accordingly, it is not necessary to configure a plurality of heat dissipation fans respectively corresponding to the first heat sink 120, the second heat sink 130 and the third heat sink 140, which is conducive to the miniaturization design of the projection device 100.

[0038] In this embodiment, the projection device 100 is, for example, at least a part of a car lamp. Specifically, the projection device 100 can be a micro-projection device and can be used with adaptive driving beam (ADB) technology as a car lamp to project driving information. In other embodiments, the projection device 100 can be other types of projection equipment, and the present invention is not limited thereto.

[0039] Please refer to Figure 3 and Figure 4In this embodiment, the first heat sink 120 is located between the heat dissipation fan 150 and the second heat sink 130 and has a through hole 120a, so that the flow path P2 passes through the through hole 120a and the second heat sink 130 in sequence. In detail, the first heat sink 120 includes a plate 122 and a heat dissipation fin group 124, the plate 122 has a first opening 122a, the heat dissipation fin group 124 is disposed on the plate 122 and has a second opening 124a, and the first opening 122a and the second opening 124a are aligned with each other to form the through hole 120a. In addition, please refer to Figure 4 and Figure 5 The projection device 100 of this embodiment further includes a frame 160 having a guiding inclined surface 162 . The guiding inclined surface 162 extends from the through hole 120 a toward the second heat sink 130 to guide the heat dissipation airflow to the second heat sink 130 .

[0040] Furthermore, the projection device 100 of this embodiment further includes a first circuit board 170 and a second circuit board 180. The first circuit board 170 is, for example, a control circuit board and is provided with the aforementioned light valve 116 (shown in FIG. Figure 2 and Figure 6 The second circuit board 180 is, for example, a power drive board. The second heat sink 130 is disposed on the first circuit board 170 to connect the light valve 116. The frame 160 is located between the first circuit board 170 and the second circuit board 180 to support the second circuit board 180 away from the first circuit board 170.

[0041] As described above, the second circuit board 180 has at least one heating element 182, the frame 160 has a slot 160a, and a portion of the flow path P2 of the heat dissipation airflow ( Figure 4 and Figure 5 The flow path (denoted as flow path P2') sequentially passes through the through hole 120a, the space between the first circuit board 170 and the frame 160, the slot 160a and the heating element 182 to dissipate heat for the heating element 182. In addition, the guiding slope 162 is, for example, formed at the edge of the slot 160a.

[0042] As described above, the heat dissipation airflow generated by the heat dissipation fan 150 of the present embodiment can flow smoothly toward the second heat dissipation element 130 by being guided by the guide slope 162 of the existing frame 160 for assembling the circuit board. In addition, the slot 160a of the frame 160 not only forms the guide slope 162 at its edge, but also allows the heat dissipation airflow to flow toward the second circuit board 180, so that the heating element 182 on the second circuit board 180 can also be cooled by the heat dissipation airflow generated by the heat dissipation fan 150.

[0043] Figure 7 FIG. 4 is a side view of some components of a projection device according to another embodiment of the present invention. Figure 8 yes Figure 7A three-dimensional view of some components of the device body. Fig. 9 Draw Figure 8 The light emitting element, the light valve and the wavelength conversion element are connected to the first heat sink, the second heat sink and the third heat sink respectively. Figures 7 to 9 In the projection device 200 shown in FIG. 1 , the configuration and function of the device body 210, the light emitting element 212, the wavelength conversion element 214, the light valve 216, the projection lens 218, the first heat sink 220, the second heat sink 230, the third heat sink 240, the heat dissipation fan 250, the second circuit board 280, and the heating element 282 are the same or similar to those of FIG. Figures 1 to 6 The configuration and function of the device body 110, the light emitting element 112, the wavelength conversion element 114, the light valve 116, the projection lens 118, the first heat sink 120, the second heat sink 130, the third heat sink 140, the cooling fan 150, the second circuit board 180, and the heating element 182 are not described in detail here. The main differences between the projection device 200 and the projection device 100 are as follows.

[0044] The first contact surface 2201 of the first heat sink 220 for contacting the light emitting element 212 is parallel to the second contact surface 2301 of the second heat sink 230 for contacting the light valve 216, and the first contact surface 2201 of the first heat sink 220 for contacting the light emitting element 212 is not parallel to the third contact surface 2401 of the third heat sink 240 for contacting the wavelength conversion element 218. The angle between the first contact surface 2201 and the third contact surface 2401 is, for example, between 45 degrees and 135 degrees.

[0045] As mentioned above, the air inlet surface 254 of the heat dissipation fan 250 of the projection device 200, which is perpendicular to the air outlet surface 252, faces the second heat dissipation element 230, and the air outlet surface 252 of the heat dissipation fan 250 faces the first heat dissipation element 220. The first heat dissipation element 220 is located between the heat dissipation fan 250 and the third heat dissipation element 240. The flow path P5 of the heat dissipation airflow provided by the heat dissipation fan 250 passes through the second heat dissipation element 230, the heat dissipation fan 250, the first heat dissipation element 220 and the third heat dissipation element 240 in sequence.

[0046] In detail, in the present embodiment, the first heat sink 220 faces the heat dissipation fan 250 along the first direction D1, and the first heat sink 220 faces the third heat sink 240 along the second direction D2 perpendicular to the first direction D1. The projection device 200 further includes a housing 290, and the first heat sink 220, the second heat sink 230, the third heat sink 240 and the heat dissipation fan 250 are at least partially accommodated by the housing 290, and the housing 290 guides the heat dissipation airflow to flow in the first direction D1 and the second direction D2 in sequence. Thus, the flow path P5 of the heat dissipation airflow passes through the heat dissipation fan 250 and the first heat sink 220 in sequence along the first direction D1, and passes through the first heat sink 220 and the third heat sink 240 in sequence along the second direction D2. Accordingly, the heat dissipation airflow provided by the heat dissipation fan 250 can smoothly and sequentially dissipate heat for the second heat sink 230, the first heat sink 220 and the third heat sink 240. In addition, the heat dissipation airflow can drive the air flow at the heating element 282 on the second circuit board 280 to dissipate heat for the heating element 282.

[0047] Fig.10 It is a three-dimensional diagram of some components of a projection device according to another embodiment of the present invention. Fig.11 yes Fig.10 A three-dimensional view of some components of the device body. Fig.12 Draw Fig.11 The light emitting element, the light valve and the wavelength conversion element are connected to the first heat sink, the second heat sink and the third heat sink respectively. Figures 10 to 12 In the projection device 300 shown in FIG. 1 , the configuration and function of the device body 310, the light emitting element 312, the wavelength conversion element 314, the light valve 316, the projection lens 318, the first heat sink 320, the second heat sink 330, the third heat sink 340, and the heat dissipation fan 350 are the same or similar to those of FIG. Figures 1 to 6 The configuration and operation of the device body 110, the light emitting element 112, the wavelength conversion element 114, the light valve 116, the projection lens 118, the first heat sink 120, the second heat sink 130, the third heat sink 140, and the cooling fan 150 are not described in detail here. The main differences between the projection device 300 and the projection device 100 are as follows.

[0048] The device body 310 does not include a light diffusion element. The first contact surface 3201 of the first heat sink 320 for contacting the light emitting element 212, the second contact surface 3301 of the second heat sink 330 for contacting the light valve 316, and the third contact surface 3401 of the third heat sink 340 for contacting the wavelength conversion element 318 are not parallel to each other. The angle between any two of the first contact surface 3201, the second contact surface 3301, and the third contact surface 3401 is, for example, between 45 degrees and 135 degrees.

[0049] As described above, the second heat sink 330 and the third heat sink 340 overlap each other in a vertical direction D3 parallel to the air outlet surface 352, and the second heat sink 330 and the third heat sink 340 overlap the first heat sink 320 in a horizontal direction D4 parallel to the air outlet surface 352. The air outlet surface 352 of the heat dissipation fan 350 faces the first heat sink 320, the second heat sink 330 and the third heat sink 340, and the flow path P6 of the heat dissipation airflow provided by the heat dissipation fan 350 passes through the first heat sink 320, the flow path P7 of the heat dissipation airflow provided by the heat dissipation fan 350 passes through the second heat sink 330, and the flow path P8 of the heat dissipation airflow provided by the heat dissipation fan 350 passes through the third heat sink 340. Accordingly, the heat dissipation airflow provided by the heat dissipation fan 350 can smoothly dissipate heat for the first heat sink 320, the second heat sink 330 and the third heat sink 340.

[0050] Fig.13 FIG. 4 is a side view of some components of a projection device according to another embodiment of the present invention. Fig.14 yes Fig.13 A three-dimensional diagram of some components of the device body. Fig.13 and Fig.14 In the projection device 400 shown in FIG. 1 , the configuration and function of the device body 410, the light emitting element 412, the wavelength conversion element 414, the light valve 416, the projection lens 418, the first heat sink 420, the second heat sink 430, the third heat sink 440, and the heat dissipation fan 450 are the same or similar to those of FIG. Figures 1 to 6 The configuration and operation of the device body 110, the light emitting element 112, the wavelength conversion element 114, the light valve 116, the projection lens 118, the first heat sink 120, the second heat sink 130, the third heat sink 140, and the cooling fan 150 are not described in detail here. The main differences between the projection device 400 and the projection device 100 are as follows.

[0051] The device body 410 does not include a light diffusion element. The first contact surface 4201 of the first heat sink 420 for contacting the light emitting element 412 is parallel to the third contact surface 4401 of the third heat sink 440 for contacting the wavelength conversion element 418, and the first contact surface 4201 of the first heat sink 420 for contacting the light emitting element 412 is not parallel to the second contact surface 4301 of the second heat sink 430 for contacting the light valve 416. The angle between the first contact surface 4201 and the second contact surface 4301 is, for example, between 45 degrees and 135 degrees.

[0052] As mentioned above, the air outlet surface 452 of the heat dissipation fan 450 faces the second heat dissipation element 430 and the third heat dissipation element 440, and the third heat dissipation element 440 is located between the heat dissipation fan 450 and the first heat dissipation element 420. The flow path P9 of the heat dissipation airflow provided by the heat dissipation fan 450 passes through the second heat dissipation element 430, and the flow path P10 of the heat dissipation airflow provided by the heat dissipation fan 450 passes through the third heat dissipation element 440 and the first heat dissipation element 420 in sequence. Accordingly, the heat dissipation airflow provided by the heat dissipation fan 450 can smoothly dissipate heat for the first heat dissipation element 420, the second heat dissipation element 430, and the third heat dissipation element 440.

[0053] In summary, the present invention arranges the first heat sink, the second heat sink and the third heat sink corresponding to the light emitting element, the light valve and the wavelength conversion element respectively so as to be located on the flow path of the heat dissipation airflow provided by a single heat dissipation fan, and the first heat sink, the second heat sink and the third heat sink can be cooled by a single heat dissipation fan. Accordingly, it is not necessary to configure a plurality of heat dissipation fans corresponding to the first heat sink, the second heat sink and the third heat sink respectively, which is conducive to the miniaturization design of the projection device.

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

Claims

1. A projection device, characterized in that: include: The device body includes a light emitting element, a wavelength conversion element, a light valve and a projection lens, wherein the light emitting element is used to emit an illumination beam, the wavelength conversion element is used to convert the wavelength of part of the illumination beam, the light valve is used to convert the illumination beam from the light emitting element and the wavelength conversion element into an image beam, and the projection lens is used to project the image beam; A first heat sink, a second heat sink and a third heat sink are respectively connected to the light emitting element, the light valve and the wavelength conversion element; and The cooling fan has an air outlet surface and is used to provide a cooling airflow, wherein the air outlet surface faces at least one of the first cooling element, the second cooling element and the third cooling element, and the first cooling element, the second cooling element and the third cooling element are all located on at least one flow path of the cooling airflow.

2. The projection device according to claim 1, characterized in that: The air outlet surface faces the first heat sink and the third heat sink. The first heat sink is located between the heat dissipation fan and the second heat sink and has a through hole. The flow paths include three, one of which passes through the first heat sink, another passes through the through hole and the second heat sink in sequence, and another passes through the third heat sink.

3. The projection device according to claim 2, characterized in that: The first heat sink comprises a plate body and a heat sink fin group, the plate body has a first opening, the heat sink fin group is disposed on the plate body and has a second opening, the first opening and the second opening are aligned with each other to form the through hole; The projection device also includes: A frame having a guiding inclined surface extending in a direction from the through hole toward the second heat dissipation element; A first circuit board and a second circuit board, the second heat sink is disposed on the first circuit board, and the frame is located between the first circuit board and the second circuit board to support the second circuit board away from the first circuit board; The frame has a slot, and the guiding slope is formed at the edge of the slot; the second circuit board has at least one heating element, and the at least one flow path passes through the through hole, the space between the first circuit board and the frame, the slot and the at least one heating element in sequence.

4. The projection device according to claim 1, wherein: The heat dissipation fan has an air inlet surface, and the air inlet surface is perpendicular to the air outlet surface; The air inlet surface faces the second heat sink, the air outlet surface faces the first heat sink, the first heat sink is located between the heat sink fan and the third heat sink, and the at least one flow path passes through the second heat sink, the heat sink fan, the first heat sink and the third heat sink in sequence.

5. The projection device according to claim 1, characterized in that: Also includes a housing, wherein the first heat sink, the second heat sink, the third heat sink and the heat sink fan are at least partially accommodated by the housing; The first heat sink faces the heat dissipation fan along a first direction, and the first heat sink faces the third heat sink along a second direction different from the first direction. The at least one flow path passes through the heat dissipation fan and the first heat sink in sequence along the first direction and passes through the first heat sink and the third heat sink in sequence along the second direction. The shell guides the heat dissipation airflow to flow in the first direction and the second direction in sequence.

6. The projection device according to claim 5, characterized in that: The first direction is perpendicular to the second direction.

7. The projection device according to claim 1, characterized in that: The air outlet surface faces the first heat sink, the second heat sink and the third heat sink; the second heat sink and the third heat sink overlap each other in a vertical direction parallel to the air outlet surface, and the second heat sink and the third heat sink overlap the first heat sink in a horizontal direction parallel to the air outlet surface; The flow paths include three, and the three flow paths pass through the first heat sink, the second heat sink, and the third heat sink respectively.

8. The projection device according to claim 1, wherein: The air outlet surface faces the second heat sink and the third heat sink. The third heat sink is located between the heat sink fan and the first heat sink. The flow path includes two flow paths, one of which passes through the second heat sink, and the other flow path passes through the third heat sink and the first heat sink in sequence.

9. The projection device according to claim 1, wherein: Along the air outlet direction of the heat dissipation fan, the first heat dissipation element, the second heat dissipation element and the third heat dissipation element are all overlapped with the heat dissipation fan.

10. The projection device according to claim 1, characterized in that: The first heat dissipation member has a first contact surface contacting the light emitting element, the second heat dissipation member has a second contact surface contacting the light valve, and the third heat dissipation member has a third contact surface contacting the wavelength conversion element; The first contact surface, the second contact surface and the third contact surface are not parallel to each other, and the angle between any two of the first contact surface, the second contact surface and the third contact surface is between 45 degrees and 135 degrees; or, The first contact surface is parallel to one of the second contact surface and the third contact surface and is not parallel to the other one of the second contact surface and the third contact surface. The angle between the first contact surface and the other one of the second contact surface and the third contact surface is between 45 degrees and 135 degrees.

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