TWI849675B - Illumination device and projection apparatus - Google Patents

Abstract

A illumination device includes a first heat source, a second heat source, a third heat source, a first porous heat exchange element, a second porous heat exchange element, a third porous heat exchange element, a first airflow guide tube and a second airflow guide tube. The first porous heat exchange element is connected to the first heat source. The second porous heat exchange element is connected to the second heat source. The third porous heat exchange element is connected to the third heat source. The first airflow guide tube is connected to the first porous heat exchange element and the third porous heat exchange element. The second airflow guide tube is connected to the second porous heat exchange element and the third porous heat exchange element. A projection apparatus having the illumination device is also provided.

Description

Lighting and projection equipment

The present invention relates to an imaging device, in particular to a lighting device with heat dissipation function and a projection device having the lighting device.

The light source used in the lighting device of the projection device has evolved from ultra-high pressure mercury lamp (UHP lamp), light emitting diode (LED) to laser diode (LD) as the market demands for the brightness, color saturation, service life, non-toxicity and environmental protection of the projection device. In detail, the above-mentioned various light sources will generate a lot of heat energy when the projection device is in operation, so most of the known projection devices will be equipped with heat dissipation elements to dissipate the heat of the light source. In addition, the above-mentioned LED or laser diode light source usually includes multiple light sources with different luminous wavelengths, and the heat dissipation efficiency required for each light source is slightly different.

Generally speaking, most known heat sinks use fins as heat dissipation media. However, because the heat dissipation area of the fins is limited, the known heat sink must have a larger volume to provide sufficient heat dissipation efficiency. Therefore, the known heat sink often occupies too much space in the projection device and the lighting device, making it difficult to flexibly configure the known heat sink according to the heat dissipation requirements of different light sources.

This "Prior Art" section is only used to help understand the content of the present invention, so the content disclosed in the "Prior Art" may contain some content that does not constitute the common knowledge of the person with ordinary knowledge in the relevant technical field. In addition, the content disclosed in the "Prior Art" does not represent the content or the problem to be solved by one or more embodiments of the present invention, nor does it mean that it has been known or recognized by the person with ordinary knowledge in the relevant technical field before the application of the present invention.

The present invention provides a lighting device to improve the heat dissipation efficiency of the heat source of the lighting device within a limited space.

The present invention provides a projection device to improve durability and image quality.

Other purposes and advantages of the present invention can be further understood from the technical features disclosed in the present invention.

To achieve one or part or all of the above purposes or other purposes, the lighting device provided by the present invention includes a first heat source, a second heat source, a third heat source, a first porous heat dissipation element, a second porous heat dissipation element, a third porous heat dissipation element, a first air duct and a second air duct. The first porous heat dissipation element is connected to the first heat source. The first porous heat dissipation element has a first ventilation side, a second ventilation side and a plurality of first flow channels. The first ventilation side and the second ventilation side are opposite, and the first flow channel extends from the first ventilation side to the second ventilation side. The second porous heat dissipation element is connected to the second heat source. The second porous heat dissipation element has a third ventilation side, a fourth ventilation side and a plurality of second flow channels. The third ventilation side and the fourth ventilation side are opposite, and the second flow channel extends from the third ventilation side to the fourth ventilation side. The third porous heat dissipation element is connected to the third heat source. The third porous heat dissipation element has a fifth ventilation side, a sixth ventilation side and a plurality of third flow channels. The fifth ventilation side and the sixth ventilation side are opposite to each other, and the third flow channel extends from the fifth ventilation side to the sixth ventilation side. The first flow guide tube connects the second ventilation side and the fifth ventilation side, and is connected to the first flow channel and the third flow channel. The second flow guide tube connects the fourth ventilation side and the sixth ventilation side, and is connected to the second flow channel and the third flow channel.

In one embodiment of the present invention, the first porous heat dissipation element may also have a plurality of first side walls, the first side walls being located between the first ventilation side and the second ventilation side. The second porous heat dissipation element may also have a plurality of second side walls, the second side walls being located between the third ventilation side and the fourth ventilation side. The third porous heat dissipation element may also have a plurality of third side walls, the third side walls being located between the fifth ventilation side and the sixth ventilation side.

In one embodiment of the present invention, the first porous heat dissipation element and the second porous heat dissipation element are opposite to each other, and the third porous heat dissipation element is located between the first porous heat dissipation element and the second porous heat dissipation element. The third porous heat dissipation element may also have a third side wall and a seventh ventilation side opposite to each other, and the third side wall and the seventh ventilation side are connected between the fifth ventilation side and the sixth ventilation side. The seventh ventilation side has a plurality of vents, and the vents are connected to the third flow channel.

In one embodiment of the present invention, the third porous heat dissipation element may also have a fourth side wall and a fifth side wall opposite to each other. The fourth side wall and the fifth side wall are connected between the fifth ventilation side and the sixth ventilation side, and are connected with the third side wall and the seventh ventilation side to form an airflow space. The vent, for example, includes a plurality of ventilation gaps, and in the direction from the fourth side wall to the fifth side wall, the width of the ventilation gap is smaller than the width of the third flow channel.

In one embodiment of the present invention, the third side wall has, for example, a first surface and a second surface opposite to each other. The third heat source is disposed on the first surface. The fifth ventilation side, the sixth ventilation side and the third flow channel are located on part or all of the second surface.

In one embodiment of the present invention, the third flow channel mentioned above may be located on a portion of the second surface. The third porous heat dissipation element may include a first heat dissipation block and a second heat dissipation block. The fifth ventilation side and a portion of the third flow channel are located in the first heat dissipation block, and the sixth ventilation side and another portion of the third flow channel are located in the second heat dissipation block. In the direction from the fifth ventilation side to the sixth ventilation side, the first heat dissipation block and the second heat dissipation block are separated from each other.

In one embodiment of the present invention, the above-mentioned lighting device also includes a fan. The fan is arranged on the first ventilation side, the third ventilation side and/or the seventh ventilation side.

In one embodiment of the present invention, the lighting device may further include a third air guide tube. The fan is at least disposed on the seventh ventilation side, and the third air guide tube is connected to the fan and the ventilation port.

In one embodiment of the present invention, the first heat source, the second heat source and the third heat source may respectively include light sources, and the light source of the third heat source is used to generate a green light beam.

In one embodiment of the present invention, the lighting device further includes a fan. The fan is disposed on the first ventilation side and/or the second ventilation side.

In one embodiment of the present invention, the first heat source, the second heat source and the third heat source mentioned above respectively include light sources, for example.

In one embodiment of the present invention, the first air guide tube and the second air guide tube may have a bending portion respectively. The bending portion may have a plurality of heat sink fins respectively, wherein the heat sink fins are arranged through the bending portion.

In one embodiment of the present invention, the shapes of the first flow channel, the second flow channel, and the third flow channel may include cylindrical or hexagonal columns.

In one embodiment of the present invention, the first flow channel mentioned above can be fully distributed in the first porous heat dissipation element. The second flow channel can be fully distributed in the second porous heat dissipation element. The third flow channel can be fully distributed in the third porous heat dissipation element.

In one embodiment of the present invention, the above-mentioned lighting device further includes a heat dissipation layer. The heat dissipation layer is disposed in all of the first flow channel, all of the second flow channel, and all of the third flow channel, or is disposed in part of the first flow channel, part of the second flow channel, and part of the third flow channel.

In one embodiment of the present invention, the material of the first flow guide tube and the material of the second flow guide tube include metal or plastic, for example.

In one embodiment of the present invention, the lighting device may further include a first heat conductor, a second heat conductor, a third heat conductor and a heat conductive layer. The first heat conductor is fixed to the first porous heat dissipation element. The second heat conductor is fixed to the second porous heat dissipation element. The third heat conductor is fixed to the third porous heat dissipation element. The heat conductive layer is disposed between the first heat conductor and the first porous heat dissipation element, between the second heat conductor and the second porous heat dissipation element, and between the third heat conductor and the third porous heat dissipation element.

In one embodiment of the present invention, the volumes of the first flow channels mentioned above may be different from each other, the volumes of the second flow channels may be different from each other, and the volumes of the third flow channels may be different from each other.

In one embodiment of the present invention, the projection device includes an illumination device, a display element, and a projection lens. The illumination device is used to provide an illumination beam, and the illumination device includes a first heat source, a second heat source, a third heat source, a first porous heat dissipation element, a second porous heat dissipation element, a third porous heat dissipation element, a first air duct, and a second air duct. The first porous heat dissipation element is connected to the first heat source. The first porous heat dissipation element has a first ventilation side, a second ventilation side, and a plurality of first flow channels, the first ventilation side and the second ventilation side are opposite, and the first flow channels extend from the first ventilation side to the second ventilation side. The second porous heat dissipation element is connected to the second heat source. The second porous heat dissipation element has a third ventilation side, a fourth ventilation side, and a plurality of second flow channels. The third ventilation side and the fourth ventilation side are opposite, and the second flow channels extend from the third ventilation side to the fourth ventilation side. The third porous heat dissipation element is connected to the third heat source. The third porous heat dissipation element has a fifth ventilation side, a sixth ventilation side and a plurality of third flow channels. The fifth ventilation side and the sixth ventilation side are opposite to each other, and the third flow channels extend from the fifth ventilation side to the sixth ventilation side. The first air guide tube is connected to the second ventilation side and the fifth ventilation side, and is connected to the first flow channels and the third flow channels. The second air guide tube is connected to the fourth ventilation side and the sixth ventilation side, and is connected to the second flow channels and the third flow channels. The display element is located on the transmission path of the illumination beam, and is used to receive the illumination beam and convert the illumination beam into an image beam. The projection lens is located on the transmission path of the image beam, and is used to project the image beam out of the projection device.

The lighting device of the present invention adopts a first porous heat dissipation element, a second porous heat dissipation element and a third porous heat dissipation element to dissipate heat from a first heat source, a second heat source and a third heat source. In detail, because the first porous heat dissipation element, the second porous heat dissipation element and the third porous heat dissipation element can provide sufficient heat dissipation area within a limited volume, they can be more flexibly configured according to the heat dissipation requirements of the heat source. In addition, the first porous heat dissipation element and the third porous heat dissipation element are connected by a first air duct, and the second porous heat dissipation element and the third porous heat dissipation element are connected by a second air duct. Furthermore, the first air duct and the second air duct can prevent a large amount of airflow from being lost between the first porous heat dissipation element, the second porous heat dissipation element and the third porous heat dissipation element, thereby increasing the airflow through the first porous heat dissipation element, the second porous heat dissipation element and the third porous heat dissipation element. Therefore, the projection device and lighting device of the present invention can improve the heat dissipation efficiency of the heat source within a limited space, and further improve the durability and image quality of the projection device.

In order to make the above and other purposes, features and advantages of the present invention more clearly understood, the following is a detailed description of the preferred embodiment with the accompanying drawings.

100, 100b, 100c, 100d, 100e: lighting device

110: First heat source

120: Second heat source

130: The third heat source

140, 140a, 140b: first porous heat dissipation element

141: First ventilation side

142: Second ventilation side

143, 143a, 143b: first flow channel

144: First side wall

145, 155, 168: Lukongbu

150: Second porous heat dissipation element

151: Third ventilation side

152: Fourth ventilation side

153: Second flow channel

154: Second side wall

160, 160a: third porous heat dissipation element

161, 161a: Fifth ventilation side

162, 162a: Sixth ventilation side

163, 163a: The third flow channel

164: Third side wall

165: Seventh ventilation side

166: Fourth side wall

167: Fifth side wall

170, 170c: first flow guide tube

180, 180c: Second flow guide tube

171c, 181c: bending part

190: The third guide tube

200: Projection device

210: Display element

220: Projection lens

B: Heat dissipation area

B1: The first heat dissipation area

B2: Second heat dissipation area

C1: First heat conductor

C2: Second heat conductor

C3: The third heat conductor

CF1, CF2: heat sink fins

CL: Thermal Conductive Layer

D1, D2, D3: Direction

F: Fan

G: Ventilation gap

HL: Heat dissipation layer

IS: medial surface

L1: lighting beam

L2: Image beam

O1, O2, O3, O1b: Open

P1: The first paragraph

P2: The second paragraph

S1: First surface

S2: Second surface

T1, T2, T3, T1b: wall thickness

V:Ventilation

W, WG: width

W1: Side wall

Figure 1 is a schematic diagram of a lighting device according to an embodiment of the present invention.

Figure 2 is a three-dimensional schematic diagram of the first porous heat dissipation element in Figure 1.

Figure 3 is a schematic diagram of the second ventilation side of the first porous heat dissipation element of Figure 2.

Figure 4 is a three-dimensional schematic diagram of the second porous heat dissipation element in Figure 1.

Figure 5 is a schematic diagram of the third ventilation side of the second porous heat dissipation element of Figure 4.

Figure 6 is a three-dimensional schematic diagram of the third porous heat dissipation element in Figure 1.

FIG7 is a schematic diagram of the fifth ventilation side of the third porous heat dissipation element of FIG6.

Figure 8 is a three-dimensional schematic diagram of the first porous heat dissipation element of another embodiment of the present invention.

Figure 9 is a schematic diagram of the first porous heat dissipation element of another embodiment of the present invention.

Figure 10 is a schematic diagram of a lighting device of another embodiment of the present invention.

Figure 11 is a three-dimensional schematic diagram of the third porous heat dissipation element of Figure 10.

FIG12 is a schematic diagram of the fifth ventilation side of the third porous heat dissipation element of FIG11.

Figure 13 is a schematic diagram of a lighting device of another embodiment of the present invention.

Figure 14 is a three-dimensional schematic diagram of the first flow guide tube in Figure 13.

Figure 15 is a schematic diagram of a lighting device of another embodiment of the present invention.

Figure 16 is a schematic diagram of the first porous heat dissipation element of another embodiment of the present invention.

Figure 17 is a schematic diagram of the first porous heat dissipation element of another embodiment of the present invention.

Figure 18 is a block diagram of a projection device according to an embodiment of the present invention.

The other technical contents, features and effects of the present invention mentioned above will be clearly presented in the detailed description of the preferred embodiment with reference to the following drawings. The directional terms mentioned in the following embodiments, such as up, down, left, right, front or back, etc., are only referenced to the directions of the attached drawings. Therefore, the directional terms used are used to illustrate and are not used to limit the present invention.

FIG. 1 is a schematic diagram of a lighting device according to an embodiment of the present invention. FIG. 2 is a three-dimensional schematic diagram of a first porous heat dissipation element of FIG. 1. FIG. 3 is a schematic diagram of a second ventilation side of the first porous heat dissipation element of FIG. 2. FIG. 4 is a three-dimensional schematic diagram of a second porous heat dissipation element of FIG. 1. FIG. 5 is a schematic diagram of a third ventilation side of the second porous heat dissipation element of FIG. 4. FIG. 6 is a three-dimensional schematic diagram of a third porous heat dissipation element of FIG. 1. FIG. 7 is a schematic diagram of a fifth ventilation side of the third porous heat dissipation element of FIG. 6.

Please refer to FIG. 1 first. In another embodiment, the lighting device 100 includes a first heat source 110, a second heat source 120, a third heat source 130, a first porous heat dissipation element 140, a second porous heat dissipation element 150, a third porous heat dissipation element 160, a first air duct 170, and a second air duct 180. The first porous heat dissipation element 140 is connected to the first heat source 110, the second porous heat dissipation element 150 is connected to the second heat source 120, and the third porous heat dissipation element 160 is connected to the third heat source 130. Please refer to FIG. 2 and FIG. 3 together. The first porous heat dissipation element 140 has a first ventilation side 141, a second ventilation side 142 (shown in FIG. 3), and a plurality of first flow channels 143. The first ventilation side 141 and the second ventilation side 142 are opposite to each other, and the first flow channel 143 extends from the first ventilation side 141 to the second ventilation side 142. Please refer to Figures 4 and 5 together, the second porous heat dissipation element 150 has a third ventilation side 151 (shown in Figure 5), a fourth ventilation side 152 and a plurality of second flow channels 153. The third ventilation side 151 and the fourth ventilation side 152 are opposite to each other, and the second flow channel 153 extends from the third ventilation side 151 to the fourth ventilation side 152. Please refer to Figures 6 and 7 together, the third porous heat dissipation element 160 has a fifth ventilation side 161 (shown in Figure 7), a sixth ventilation side 162 and a plurality of third flow channels 163. The fifth ventilation side 161 and the sixth ventilation side 162 are opposite to each other, and the third flow channel 163 extends from the fifth ventilation side 161 to the sixth ventilation side 162. As shown in FIG1 , the first air guide 170 connects the second ventilation side 142 and the fifth ventilation side 161, and communicates with the first flow channel 143 (shown in FIG2 ) and the third flow channel 163 (shown in FIG6 ). The second air guide 180 connects the fourth ventilation side 152 and the sixth ventilation side 162, and communicates with the second flow channel 153 (shown in FIG4 ) and the third flow channel 163. In other words, the first porous heat dissipation element 140 is connected to the first heat source 110, the second porous heat dissipation element 150 is connected to the second heat source 120, and the third porous heat dissipation element 160 is connected to the third heat source 130. The first air guide tube 170 is connected between the first porous heat dissipation element 140 and the third porous heat dissipation element 160, and the second air guide tube 180 is connected between the second porous heat dissipation element 150 and the third porous heat dissipation element 160.

In this embodiment, the lighting device 100 further includes a fan F. The fan F is disposed on the first ventilation side 141 and/or the third ventilation side 151, and this embodiment takes the example of the fan F being disposed on the first ventilation side 141 and the third ventilation side 151. Specifically, the fan F can guide airflow to flow through the first porous heat dissipation element 140, the second porous heat dissipation element 150, the third porous heat dissipation element 160, the first air guide tube 170, and the second air guide tube 180. For example, the fan F can guide the airflow to flow through the first porous heat dissipation element 140, the first air guide tube 170, the third porous heat dissipation element 160, the second air guide tube 180 and the second porous heat dissipation element 150 in sequence, but it is not limited to this. The airflow path can be determined by whether the fan F is set to suction or exhaust, so the airflow path can also flow through the second porous heat dissipation element 150, the second air guide tube 180, the third porous heat dissipation element 160, the first air guide tube 170 and the first porous heat dissipation element 140 in sequence. It can be understood that the number of fans F is not limited to that shown in Figure 1. For example, in another embodiment, the number of fans F can be one, and the fan F can be located at the first ventilation side 141 or the second ventilation side 142. The number of fans F can be determined based on factors such as heat dissipation requirements and product costs, so the present invention does not impose any restrictions on this. Incidentally, the fan F of this embodiment may include an axial flow fan, but in other embodiments, the fan F may include a blower fan.

In this embodiment, the first porous heat dissipation element 140, the second porous heat dissipation element 150 and the third porous heat dissipation element 160 can allow the airflow generated by the fan F to pass through, so as to provide a heat dissipation function. Please refer to Figures 2 and 3 together. The first porous heat dissipation element 140 may also have a plurality of first side walls 144, and the first side walls 144 are located between the first ventilation side 141 and the second ventilation side 142. In detail, the first flow channel 143 can form a plurality of openings O1 on the first ventilation side 141 and the second ventilation side 142 to allow the airflow generated by the fan F to pass through. On the other hand, the first side wall 144 can prevent the airflow from flowing out from the part other than the first ventilation side 141 and the second ventilation side 142, so as to increase the airflow through the first flow channel 143, thereby improving the heat dissipation efficiency. For example, each first flow channel 143 may be cylindrical in shape, and the airflow generated by the fan F may pass through each first flow channel 143 in the axial direction, while the first side wall 144 may be disposed axially around the first flow channel 143 to prevent the airflow from flowing out radially along each first flow channel 143.

Please refer to FIG. 4 and FIG. 5 together. Similarly, the second porous heat dissipation element 150 may also have a plurality of second side walls 154, and the second side walls 154 are located between the third ventilation side 151 and the fourth ventilation side 152. In other words, the second flow channel 153 may form a plurality of openings O2 at the third ventilation side 151 and the fourth ventilation side 152 for the airflow generated by the fan F to pass through. In addition, the second side wall 154 can prevent the airflow from flowing out of the portion other than the third ventilation side 151 and the fourth ventilation side 152, so as to increase the airflow through the second flow channel 153, thereby improving the heat dissipation efficiency. For example, each second flow channel 153 may be cylindrical in shape, and the airflow generated by the fan F may pass through each second flow channel 153 in the axial direction, while the second side wall 154 may be disposed around the axial direction of the second flow channel 153 to prevent the airflow from flowing out in the radial direction of each second flow channel 153.

Please refer to FIG. 6 and FIG. 7 together. Similarly, the third porous heat dissipation element 160 may also have a plurality of third side walls 164, and the third side walls 164 are located between the fifth ventilation side 161 and the sixth ventilation side 162. In detail, the third flow channel 163 may form a plurality of openings O3 at the fifth ventilation side 161 and the sixth ventilation side 162 for the airflow generated by the fan F to pass through. In addition, the third side wall 164 can prevent the airflow from flowing out of the portion other than the fifth ventilation side 161 and the sixth ventilation side 162, so as to increase the airflow through the third flow channel 163, thereby improving the heat dissipation efficiency. For example, each third flow channel 163 may be cylindrical in shape, and the airflow generated by the fan F may pass along the axial direction of each third flow channel 163, while the third side wall 164 may be arranged axially around the third flow channel 163 to prevent the airflow from flowing out radially along each third flow channel 163.

As shown in FIG. 2, FIG. 4 and FIG. 6, the shapes of the first flow channel 143, the second flow channel 153 and the third flow channel 163 may include cylindrical or hexagonal columns, wherein FIG. 2, FIG. 4 and FIG. 6 use hexagonal columns as examples. In other words, the cross-sectional shapes of the first flow channel 143, the second flow channel 153 and the third flow channel 163 parallel to the radial and circumferential directions may be hexagonal. In addition, FIG. 8 uses the first porous heat dissipation element 140a as an example of a cylindrical first flow channel 143a, and the cylindrical second flow channel and the third flow channel are roughly similar to FIG. 8. Similarly, the cross-sectional shapes of the first flow channel 143a, the second flow channel and the third flow channel parallel to the radial and circumferential directions may be circular. Please refer to FIG. 2, FIG. 4 and FIG. 6 again. Because the shapes of the first flow channel 143, the second flow channel 153 and the third flow channel 163 may include hexagonal columns (or cylindrical shapes), the volume ratios of the first flow channel 143, the second flow channel 153 and the third flow channel 163 in the first porous heat sink 140, the second porous heat sink 150 and the third porous heat sink 160 can be maximized, thereby further improving the heat dissipation efficiency. Specifically, compared to the conventional heat sink using fins, the heat dissipation area formed by the first flow channel 143 in the first porous heat sink 140 can be increased by more than 20% compared to the conventional fins. Similarly, the heat dissipation area formed by the second flow channel 153 in the second porous heat dissipation element 150 and the heat dissipation area formed by the third flow channel 163 in the third porous heat dissipation element 160 can be increased by about 20% or more compared with the conventional fins. For example, in one embodiment, the heat dissipation area formed by the first flow channel 143, the second flow channel 153 and the third flow channel 163 in the first porous heat dissipation element 140 can be about 200000~ ^220000mm2 , however, the conventional fin heat dissipation element of the same volume can only provide a heat dissipation area of about ^160000mm2 at most. Therefore, it can be seen that under the same volume, the heat dissipation area formed by the porous heat dissipation element can be increased by {((200000~220000)-160000)/(200000~220000)}*100%=20%~27% compared with the heat dissipation area of the conventional fin.

Please refer to Figures 2 and 3. In this embodiment, the first flow channel 143 can be distributed throughout the first porous heat dissipation element 140, so that the volume ratio of the first flow channel 143 in the first porous heat dissipation element 140 can be maximized, thereby further improving the heat dissipation efficiency. In this embodiment, the first porous heat dissipation element 140 also includes a hollow portion 145. The hollow portion 145 is, for example, a screw locking area, which can be used to fix the first porous heat dissipation element 140 with other elements. The present invention does not impose more restrictions on the position of the screw locking. Please refer to Figures 4 and 5 again. Similarly, the second flow channel 153 of this embodiment can be distributed throughout the second porous heat dissipation element 150. The second porous heat dissipation element 150 also includes a hollow portion 155, which is, for example, a screw locking area, which can be used to fix the second porous heat dissipation element 140 with other elements. The present invention does not impose more restrictions on the position of the screw locking. Similarly, as shown in Figures 6 and 7, the third flow channel 163 can be distributed in the third porous heat dissipation element 160. The third porous heat dissipation element 160 also includes a hollow portion 168, which is, for example, a screw locking area, which can be used to fix the third porous heat dissipation element 140 with other elements. The present invention does not impose more restrictions on the position of the screw locking.

Please refer to FIG. 3 , FIG. 5 and FIG. 7 . In one embodiment, the wall thickness T1 of any one of the first flow channels 143 , the wall thickness T2 of any one of the second flow channels 153 and the wall thickness T3 of any one of the third flow channels 163 are, for example, all less than 1.2 mm. In this way, the volume ratio of the first flow channel 143 in the first porous heat dissipation element 140 , the volume ratio of the second flow channel 153 in the second porous heat dissipation element 150 and the volume ratio of the third flow channel 163 in the third porous heat dissipation element 160 can be further increased, so that the first porous heat dissipation element 140 , the second porous heat dissipation element 150 and the third porous heat dissipation element 160 have a larger heat dissipation area, thereby further improving the heat dissipation efficiency. For example, in one embodiment, the wall thickness T1 of the first flow channel 143, the wall thickness T2 of the second flow channel 153, and the wall thickness T3 of the third flow channel 163 are, for example, about 1 to 1.2 mm. However, for a conventional heat sink of the same volume, the thickness of the fin is at least 1.45 mm. Incidentally, please continue to refer to FIG. 3 , the first flow channel 143 can penetrate the first porous heat sink 140 to form a plurality of side walls W1, and the wall thickness T1 is, for example, the thickness of the side wall W1 between any two adjacent first flow channels 143. The wall thickness T2 of the second flow channel 153 in FIG. 5 is roughly the same as the definition of the second flow channel 153 in FIG. 7 as the first flow channel 143, so the relevant description is omitted here. Please refer to FIG. 3, FIG. 5 and FIG. 7 together. In this embodiment, the volumes of the first flow channels 143 may be the same as each other, the volumes of the second flow channels 153 may be the same as each other, and the volumes of the third flow channels 163 may be the same as each other. However, in one embodiment, such as the first porous heat dissipation element 140b shown in FIG. 9, the volumes of the first flow channels 143b may be different from each other. Similarly, the volumes of the second flow channels may be different from each other, and the volumes of the third flow channels may be different from each other. FIG. 9 takes the first flow channel 143b as an example, and the features of the second flow channel and the third flow channel are substantially the same as the first flow channel 143b. In detail, the volumes of the first flow channel 143b, the second flow channel and the third flow channel may all vary according to different flow fields or actual needs. For example, in one embodiment, the wall thickness T1b of a portion of the first flow channel 143b may be different from the wall thickness T1b of another portion of the first flow channel 143b, so that the size of the opening O1b of the portion of the first flow channel 143b is different from the size of the opening O1b of another portion of the first flow channel 143b. In another embodiment, the wall thickness T1b of each first flow channel 143b may be different from each other, so that the size of the opening O1b of each first flow channel 143b is different from each other, and the present invention does not impose more restrictions on these details. It can be understood that the characteristics of the second flow channel and the third flow channel are similar to those of the first flow channel 143b, so the relevant description is omitted here.

Please refer to FIG. 3, FIG. 5 and FIG. 7 together. It is worth mentioning that in this embodiment, because the shapes of the first flow channel 143, the second flow channel 153 and the third flow channel 163 may include hexagonal columns (or cylindrical shapes), this can not only maximize the volume ratio of the first flow channel 143 in the first porous heat dissipation element 140, the volume ratio of the second flow channel 153 in the second porous heat dissipation element 150 and the volume ratio of the third flow channel 163 in the third porous heat dissipation element 160, but also improve the structural strength of the first porous heat dissipation element 140, the second porous heat dissipation element 150 and the third porous heat dissipation element 160. Specifically, compared to the conventional heat sink using fins, although the wall thickness T1 of the first flow channel 143, the wall thickness T2 of the second flow channel 153, and the wall thickness T3 of the third flow channel 163 are smaller, the shapes of the first flow channel 143, the second flow channel 153, and the third flow channel 163 can be cylindrical or hexagonal, so the first porous heat sink 140, the second porous heat sink 150, and the third porous heat sink 160 can improve the structural strength. For example, in one embodiment, the shapes of the first flow channel 143, the second flow channel 153, and the third flow channel 163 can include hexagonal columns, and the wall thickness T1 of the first flow channel 143, the wall thickness T2 of the second flow channel 153, and the wall thickness T3 of the third flow channel 163 are, for example, about 1 mm. In another embodiment, the shapes of the first flow channel 143, the second flow channel 153, and the third flow channel 163 may include a cylindrical shape, and the wall thickness T1 of the first flow channel 143, the wall thickness T2 of the second flow channel 153, and the wall thickness T3 of the third flow channel 163 are, for example, about 1.2 mm. It is understood that the above values are only examples, and the present invention is not limited thereto.

Please refer to FIG. 1 again. The first air duct 170 and the second air duct 180 can guide the airflow generated by the fan F to flow more concentratedly through the first porous heat dissipation element 140, the second porous heat dissipation element 150 and the third porous heat dissipation element 160, thereby increasing the airflow rate through the first porous heat dissipation element 140, the second porous heat dissipation element 150 and the third porous heat dissipation element 160. In this embodiment, the material of the first air duct 170 and the material of the second air duct 180 include plastic, for example, so that the cost can be reduced and the overall weight of the lighting device 100 can be slightly reduced. Since the plastic material is non-thermal conductive, the low thermal conductivity property can block other external parts that generate heat. In one embodiment, the plastic can include polyester film (mylar); specifically, the polyester film can be in the shape of a sheet and formed into a tube by gluing or other methods. On the other hand, the above-mentioned plastic can be formed into a tubular shape in an integrated structure, and the present invention does not impose any restrictions on these details. In another embodiment, the material of the first air duct 170 and the material of the second air duct 180 may include metal to further improve the heat dissipation efficiency. The above-mentioned metal may include the same material as the first porous heat dissipation element 140, the second porous heat dissipation element 150 and the third porous heat dissipation element 160, such as aluminum or copper, but other embodiments are not limited to this. By the way, in this embodiment, the first air duct 170 can be fixed to the first porous heat dissipation element 140 and the third porous heat dissipation element 160 by gluing, and the second air duct 180 can also be fixed to the second porous heat dissipation element 150 and the third porous heat dissipation element 160 by gluing. In another embodiment, the first flow guide tube 170 can be screwed to the first porous heat dissipation element 140 and the third porous heat dissipation element 160, and the second flow guide tube 180 can be screwed to the second porous heat dissipation element 150 and the third porous heat dissipation element 160, and the present invention does not impose more restrictions on the fixing method.

The first heat source 110, the second heat source 120 and the third heat source 130, for example, respectively include light sources. In detail, in the present embodiment, the first heat source 110, the second heat source 120 and the third heat source 130, for example, are respectively a red light source, a blue light source and a green light source, and the red light source, the blue light source and the green light source are respectively used to generate a red light beam, a blue light beam and a green light beam. Furthermore, the light source, for example, includes a laser diode (LD), wherein the number of the laser diodes may be one or more. For example, in one embodiment, the number of the laser diodes is multiple, and the laser diodes may be arranged in a matrix. In another embodiment, the light source may include a light emitting diode (LED). Similarly, the number of the light-emitting diodes can be multiple and arranged in a matrix.

Compared with the prior art, the lighting device 100 of the present embodiment adopts a first porous heat dissipation element 140, a second porous heat dissipation element 150 and a third porous heat dissipation element 160 to dissipate heat from the first heat source 110, the second heat source 120 and the third heat source 130. In detail, because the first porous heat dissipation element 140, the second porous heat dissipation element 150 and the third porous heat dissipation element 160 can provide sufficient heat dissipation area within a limited volume, they can be more flexibly configured according to the heat dissipation requirements of the heat source. In addition, the first porous heat dissipation element 140 and the third porous heat dissipation element 160 are connected by a first air guide tube 170, and the second porous heat dissipation element 150 and the third porous heat dissipation element 160 are connected by a second air guide tube 180. Furthermore, the first air duct 170 and the second air duct 180 can prevent the airflow from escaping between the first porous heat dissipation element 140, the second porous heat dissipation element 150 and the third porous heat dissipation element 160, thereby increasing the airflow through the first porous heat dissipation element 140, the second porous heat dissipation element 150 and the third porous heat dissipation element 160. Therefore, the lighting device 100 of this embodiment can improve the heat dissipation efficiency of the heat source in a limited space.

FIG. 10 is a schematic diagram of a lighting device according to another embodiment of the present invention. FIG. 11 is a three-dimensional schematic diagram of the third porous heat dissipation element of FIG. 10. FIG. 12 is a schematic diagram of the fifth ventilation side of the third porous heat dissipation element of FIG. 11. The structure and advantages of the lighting device 100b of this embodiment are similar to those of the embodiment of FIG. 1, and only the differences are described below. Referring to FIG. 10, the first porous heat dissipation element 140 and the second porous heat dissipation element 150 are opposite, and the third porous heat dissipation element 160a is located between the first porous heat dissipation element 140 and the second porous heat dissipation element 150. Please refer to Figures 11 and 12 together. The third porous heat dissipation element 160a may also have a seventh ventilation side 165 opposite to the third side wall 164. The third side wall 164 and the seventh ventilation side 165 are connected between the fifth ventilation side 161a and the sixth ventilation side 162a. The seventh ventilation side 165 has a plurality of vents V, and the vents V are connected to the third flow channel 163a. In this way, the airflow can also flow out of (or enter) the third porous heat dissipation element 160a through the vents V, thereby improving the heat dissipation efficiency of the third porous heat dissipation element 160a to the third heat source 130 (shown in Figure 10).

Please refer to FIG. 10 and FIG. 11 together. Specifically, the fan F can be disposed on the first ventilation side 141, the third ventilation side 151 and/or the seventh ventilation side 165, and the present embodiment takes the fan F disposed on the seventh ventilation side 165 as an example. Furthermore, in the present embodiment, the fan F can extract the hot air flow in the third porous heat dissipation element 160a from the vent V, thereby improving the heat dissipation efficiency of the third porous heat dissipation element 160a to the third heat source 130. However, in one embodiment, the fan F can blow the cold air flow into the third porous heat dissipation element 160a from the vent V, and the present invention does not impose more restrictions on the airflow direction. The lighting device 100b of the present embodiment may also include a third air guide tube 190, and the third air guide tube 190 is connected to the fan F and the vent V. Specifically, the third air duct 190 can concentrate the airflow generated by the fan F, thereby increasing the airflow through the third air duct 190, thereby further improving the heat dissipation efficiency of the third porous heat dissipation element 160a to the third heat source 130. In another embodiment, the fan F can also be arranged on the first ventilation side 141 and the third ventilation side 151 to further improve the heat dissipation efficiency of the lighting device 100b. It is understood that the number of fans F can be determined according to factors such as heat dissipation requirements and product costs, so the present invention does not impose more restrictions on this. Incidentally, the fan F of this embodiment may include an axial flow fan, but in other embodiments, the fan F may include a blower fan.

Please refer to FIG. 11 and FIG. 12 again. In this embodiment, the third porous heat dissipation element 160a may also have a fourth side wall 166 and a fifth side wall 167 opposite to each other. The fourth side wall 166 and the fifth side wall 167 are connected between the fifth ventilation side 161a and the sixth ventilation side 162a, and are connected to the third side wall 164 and the seventh ventilation side 165 to form an airflow space. The vent V, for example, includes a plurality of ventilation gaps G. In the direction D1 from the fourth side wall 166 to the fifth side wall 167, the width WG of the ventilation gap G (marked in FIG. 12) is smaller than the width W (marked in FIG. 12) of the third flow channel 163a. In this way, the airflow rate through the third flow channel 163a can be further increased, thereby further improving the heat dissipation efficiency of the third porous heat dissipation element 160a. Furthermore, the ventilation gap G, for example, extends from the fifth ventilation side 161a to the sixth ventilation side 162a, and can communicate with the third flow channel 163a in the same row in the direction D2 (marked in FIG. 12) from the seventh ventilation side 165 to the third side wall 164. Therefore, the airflow in each third flow channel 163a can flow out of or enter the third porous heat dissipation element 160a through the ventilation gap G, thereby further improving the heat dissipation efficiency of the third porous heat dissipation element 160a.

Incidentally, the third sidewall 164, for example, has a first surface S1 and a second surface S2 that are opposite to each other. The third heat source 130 (shown in FIG. 1 ) is disposed on the first surface S1. The fifth ventilation side 161a, the sixth ventilation side 162a, and the third flow channel 163a are located on part or all of the second surface S2, and this embodiment takes the fifth ventilation side 161a, the sixth ventilation side 162a, and the third flow channel 163a as an example located on part of the second surface S2. Specifically, the third porous heat dissipation element 160a may have a heat dissipation block B, and the fifth ventilation side 161a, the sixth ventilation side 162a, and the third flow channel 163a are located on the heat dissipation block B; the heat dissipation block B may be disposed on the second surface S2 and may cover all or part of the second surface S2. In this embodiment, the third flow channel 163a may be located on a portion of the second surface S2; in other words, the heat dissipation block B may cover a portion of the second surface S2. Further, the third porous heat dissipation element 160a may include a first heat dissipation block B1 and a second heat dissipation block B2. The fifth ventilation side 161a and a portion of the third flow channel 163a are located in the first heat dissipation block B1, and the sixth ventilation side 162a and another portion of the third flow channel 163a are located in the second heat dissipation block B2. In the direction D3 (marked in FIG. 11) pointing from the sixth ventilation side 162a to the fifth ventilation side 161a, the first heat dissipation block B1 and the second heat dissipation block B2 are separated from each other. In detail, the third flow channel 163a may include a first section P1 and a second section P2. The first section P1 is, for example, located in the first heat dissipation block B1 and connected to the fifth ventilation side 161a. The second section P2 may be located in the second heat dissipation block B2 and connected to the sixth ventilation side 162a. In this embodiment, the second section P2 and the first section P1 are separated from each other and communicate with each other. The airflow generated by the fan F may flow out of or enter the third flow channel 163a through the ventilation gap G, and may also flow out of or enter the third flow channel 163a through the space separated between the second section P2 and the first section P1. In addition, a portion of the second surface S2 may be exposed from the first heat dissipation block B1 and the second heat dissipation block B2 separated from each other to provide space for screw locking. However, in one embodiment, the heat dissipation block B can cover the entire second surface S2, thereby further improving the heat dissipation efficiency of the third porous heat dissipation element 160a.

Incidentally, please refer to FIG. 10 again. In this embodiment, the first heat source 110, the second heat source 120 and the third heat source 130 may include light sources, respectively, and the light source of the third heat source 130 is used to generate a green light beam. Specifically, the first heat source 110, the second heat source 120 and the third heat source 130 are, for example, red light sources, blue light sources and green light sources, respectively, wherein the green light source generates more heat energy than the red light source and the blue light source. Therefore, the third heat source 130 of this embodiment can enhance heat dissipation by the third porous heat dissipation element 160a. In one embodiment, the first heat source 110 is, for example, a red light source, and the second heat source 120 can be a blue light source, but the present invention does not impose more restrictions on this. The characteristics of the red light source, the blue light source and the green light source have been described in the previous text, so the relevant description is omitted here.

FIG. 13 is a schematic diagram of a lighting device of another embodiment of the present invention. FIG. 14 is a three-dimensional schematic diagram of the first air guide tube of FIG. 13 . The structure and advantages of the lighting device 100c of this embodiment are similar to those of the embodiment of FIG. 1 , and only the differences are described below. Please refer to FIG. 13 and FIG. 14 , the first air guide tube 170c may have a bend 171c, and the second air guide tube 180c may have a bend 181c. The bend 171c may have a plurality of heat sink fins CF1, wherein the heat sink fins CF1 are disposed through the bend 171c. Similarly, please continue to refer to Figure 13, the bend portion 181c can have a plurality of heat sink fins CF2, wherein the heat sink fins CF2 are arranged through the bend portion 181c. In detail, because the airflow through the bend portions 171c and 181c has a slower flow rate, the bend portions 171c and 181c are more likely to accumulate heat energy, so the heat sink fins CF1 and CF2 can be used to enhance the heat dissipation efficiency. Furthermore, the heat sink fin CF1 can penetrate the bend 171c of the first air guide tube 170c and extend into the first air guide tube 170c; similarly, the heat sink fin CF2 can penetrate the bend 181c of the second air guide tube 180c and extend into the second air guide tube 180c to further improve the heat dissipation efficiency. In one embodiment, the heat sink fin CF1 can be first formed by die-casting and then disposed on the bend 171c. The process of disposing the heat sink fin CF2 on the bend 181c is similar to that of the heat sink fin CF1, so the relevant description is omitted here. In another embodiment, the heat sink fin CF1 can be an integral structure with the first air guide tube 170c, and the heat sink fin CF2 can be an integral structure with the second air guide tube 180c, and the present invention does not impose further restrictions on this.

FIG15 is a schematic diagram of a lighting device of another embodiment of the present invention. The structure and advantages of the lighting device 100d of this embodiment are similar to those of the embodiment of FIG1 , and only the differences are described below. Referring to FIG15 , the lighting device 100d may further include a first heat conductor C1, a second heat conductor C2, a third heat conductor C3, and a heat conductive layer CL. The first heat conductor C1 is fixed to the first porous heat dissipation element 140. The second heat conductor C2 is fixed to the second porous heat dissipation element 150. The third heat conductor C3 is fixed to the third porous heat dissipation element 160. The heat conductive layer CL is disposed between the first heat conductor C1 and the first porous heat dissipation element 140, between the second heat conductor C2 and the second porous heat dissipation element 150, and between the third heat conductor C3 and the third porous heat dissipation element 160. In this way, the heat energy accumulated in the first porous heat dissipation element 140, the second porous heat dissipation element 150 and the third porous heat dissipation element 160 can be more quickly transferred to the first heat conductor C1, the second heat conductor C2 and the third heat conductor C3 through the heat conductive layer CL, thereby further improving the heat dissipation efficiency. In detail, the material of the first heat conductor C1, the second heat conductor C2 and the third heat conductor C3 may include metal; more specifically, the first heat conductor C1, the second heat conductor C2 and the third heat conductor C3 are, for example, sheet metal parts. In addition, in this embodiment, the first porous heat dissipation element 140, the second porous heat dissipation element 150 and the third porous heat dissipation element 160 can be fixed to different heat conductors; however, in one embodiment, the first porous heat dissipation element 140, the second porous heat dissipation element 150 and the third porous heat dissipation element 160 can be fixed to the same heat conductor. In this embodiment, the thermal conductive layer CL may include a thermal pad or thermal paste. Furthermore, in one embodiment, the material of the thermal conductive layer CL may include silicone, but the present invention does not impose many restrictions on the specific material of the thermal conductive layer CL. Incidentally, in another embodiment, the material of the first air guide tube 170 and the material of the second air guide tube 180 may be metal, and the first air guide tube 170 and the second air guide tube 180 may be fixed to the heat conductive element through the thermal conductive layer CL, thereby further improving the heat dissipation efficiency.

FIG. 16 is a schematic diagram of a first porous heat dissipation element of another embodiment of the present invention. FIG. 17 is a schematic diagram of a first porous heat dissipation element of another embodiment of the present invention. The structure and advantages of the lighting device 100e of this embodiment are similar to those of the embodiment of FIG. 1 , and only the differences are described below. The lighting device 100e, for example, further includes a heat dissipation layer HL. Please refer to FIG. 16 first. The heat dissipation layer HL can be disposed in all the first flow channels 143, all the second flow channels, and all the third flow channels to further improve the heat dissipation efficiency. It should be noted that FIG. 16 takes the heat dissipation layer HL disposed in the first flow channel 143 as an example, and the characteristics of the heat dissipation layer HL disposed in the second flow channel and the third flow channel are roughly the same as FIG. 16. Specifically, the first flow channel 143 penetrates the first porous heat dissipation element 140 to form an inner side surface IS, and the heat dissipation layer HL can be disposed on the inner side surface IS. Furthermore, the heat dissipation layer HL can pass through the first flow channel 143 by the siphon principle, and adhere to the inner side surface IS when passing through the first flow channel 143. The process of dissipating the heat dissipation layer HL in the above-mentioned second flow channel and third flow channel is roughly similar to the first flow channel 143, so the relevant description is omitted here. In one embodiment, the material of the heat dissipation layer HL may include graphene, but the present invention does not impose further restrictions on this. In another embodiment, as shown in Figure 17, the heat dissipation layer HL can be disposed in part of the first flow channel 143, part of the second flow channel, and part of the third flow channel, where Figure 17 takes the first flow channel 143 as an example. In this way, the time required for setting the heat dissipation layer HL can be shortened. In other words, the first flow channel 143 can be partially shielded by a jig before the process of setting the heat dissipation layer HL is performed. The process of setting the heat dissipation layer HL in the second and third flow channels is similar to that of the first flow channel 143, so the relevant description is omitted here.

FIG18 is a block diagram of a projection device of an embodiment of the present invention. Referring to FIG18 , the lighting devices 100, 100b, 100c, 100d and 100e of the above embodiments can all be applied to the projection device 200, and the present embodiment takes the lighting device 100 as an example. The projection device 200 includes the lighting device 100, a display element 210 and a projection lens 220. The lighting device 100 is used to provide at least one of a red light beam, a blue light beam and a green light beam. At least one of the red light beam, the blue light beam and the green light beam is defined as the lighting beam L1. That is, the lighting device 100 is used to provide the lighting beam L1.

The display element 210 is located on the transmission path of the illumination light beam L1, and is used to receive the illumination light beam L1 and convert the illumination light beam L1 into an image light beam L2. The projection lens 220 is located on the transmission path of the image light beam L2, and is used to project the image light beam L2 onto a projection target. The projection target is, for example, a wall, a desktop, or a projection screen. The display element 210 is, for example, a light valve, and the light valve is, for example, a reflective light modulator such as a digital micro-mirror device (DMD) or a liquid crystal on silicon panel (LCoS panel). In some embodiments, the light valve may be, for example, a transmissive light modulator such as a transmissive liquid crystal display panel, an electro-optical modulator, a magneto-optical modulator, or an acousto-optic modulator (AOM). Of course, the display element 210 may also be other optical imaging elements, etc., and is not limited thereto. The projection lens 220 may include, for example, a combination of one or more non-planar optical lenses having a refractive power, such as various combinations of non-planar lenses such as a biconcave lens, a biconvex lens, a concave-convex lens, a convex-concave lens, a plano-convex lens, and a plano-concave lens. In one embodiment, the projection lens 220 may also include a plane optical lens to project the image beam L2 from the display element 210 out of the projection device 200 in a reflection or transmission manner.

Compared to the prior art, because the projection device 200 of this embodiment uses the lighting device 100, the projection device 200 can improve the heat dissipation efficiency in a limited space, and further improve the durability and image quality.

In summary, the lighting device of the present invention adopts a first porous heat dissipation element, a second porous heat dissipation element and a third porous heat dissipation element to dissipate heat from a first heat source, a second heat source and a third heat source. In detail, because the first porous heat dissipation element, the second porous heat dissipation element and the third porous heat dissipation element can provide sufficient heat dissipation area within a limited volume, they can be more flexibly configured according to the heat dissipation requirements of the heat source. In addition, the first porous heat dissipation element and the third porous heat dissipation element are connected by a first air duct, and the second porous heat dissipation element and the third porous heat dissipation element are connected by a second air duct. Furthermore, the first air duct and the second air duct can prevent the airflow from escaping between the first porous heat dissipation element, the second porous heat dissipation element and the third porous heat dissipation element, thereby increasing the airflow rate through the first porous heat dissipation element, the second porous heat dissipation element and the third porous heat dissipation element. Therefore, the projection device and lighting device of the present invention can improve the heat dissipation efficiency of the heat source within a limited space, and further improve the durability and image quality of the projection device.

However, the above is only the preferred embodiment of the present invention, and it cannot be used to limit the scope of the implementation of the present invention. That is, all simple equivalent changes and modifications made according to the scope of the patent application and the content of the invention description are still within the scope of the present invention. In addition, any embodiment or patent application of the present invention does not need to achieve all the purposes, advantages or features disclosed by the present invention. In addition, the abstract and title are only used to assist in searching patent documents, and are not used to limit the scope of rights of the present invention. In addition, the terms "first" and "second" mentioned in this specification or patent application are only used to name the element or distinguish different embodiments or scopes, and are not used to limit the upper or lower limit of the number of elements.

100: lighting device 110: first heat source 120: second heat source 130: third heat source 140: first porous heat dissipation element 141: first ventilation side 142: second ventilation side 150: second porous heat dissipation element 151: third ventilation side 152: fourth ventilation side 160: third porous heat dissipation element 161: fifth ventilation side 162: sixth ventilation side 170: first air guide tube 180: second air guide tube F: fan

Claims (19)

A lighting device includes: a first heat source, a second heat source and a third heat source; a first porous heat dissipation element connected to the first heat source, the first porous heat dissipation element having a first ventilation side, a second ventilation side and a plurality of first flow channels, the first ventilation side and the second ventilation side are opposite, and the first flow channels extend from the first ventilation side to the second ventilation side; a second porous heat dissipation element connected to the second heat source, the second porous heat dissipation element having a third ventilation side, a fourth ventilation side and a plurality of second flow channels, the third ventilation side and the fourth ventilation side are opposite, and the second flow channels extend from the third ventilation side to the fourth ventilation side; a third porous heat dissipation element A heat dissipation element connected to the third heat source, the third porous heat dissipation element having a fifth ventilation side, a sixth ventilation side and a plurality of third flow channels, the fifth ventilation side and the sixth ventilation side are opposite, and the third flow channels extend from the fifth ventilation side to the sixth ventilation side; a first air guide tube connected to the second ventilation side and the fifth ventilation side, and communicated with the first flow channels and the third flow channels; and a second air guide tube connected to the fourth ventilation side and the sixth ventilation side, and communicated with the second flow channels and the third flow channels, wherein the first ventilation side of the first porous heat dissipation element and the third ventilation side of the second porous heat dissipation element are suitable for air flow. The lighting device as described in claim 1, wherein the first porous heat dissipation element further comprises a plurality of first side walls, the first side walls being located between the first ventilation side and the second ventilation side, the second porous heat dissipation element further comprises a plurality of second side walls, the second side walls being located between the third ventilation side and the fourth ventilation side, and the third porous heat dissipation element further comprises a plurality of third side walls, the third side walls being located between the fifth ventilation side and the sixth ventilation side. The lighting device as described in claim 2, wherein the first heat source, the second heat source and the third heat source each include a light source, and the light source of the third heat source is used to generate a green light beam. The lighting device as described in claim 1, wherein the first heat source, the second heat source and the third heat source each include a light source. The lighting device as described in claim 1, wherein the shapes of the first flow channels, the second flow channels, and the third flow channels include cylindrical shapes or hexagonal column shapes. As described in claim 5, the first flow channels are distributed throughout the first porous heat dissipation element, the second flow channels are distributed throughout the second porous heat dissipation element, and the third flow channels are distributed throughout the third porous heat dissipation element. A lighting device as described in claim 1, wherein the material of the first air guide tube and the material of the second air guide tube include metal or plastic. The lighting device as described in claim 1, wherein the volumes of the first flow channels are different from each other, the volumes of the second flow channels are different from each other, and the volumes of the third flow channels are different from each other. A lighting device, comprising: a first heat source, a second heat source and a third heat source; a first porous heat dissipation element connected to the first heat source, the first porous heat dissipation element having a first ventilation side, a second ventilation side and a plurality of first flow channels, the first ventilation side and the second ventilation side being opposite to each other, the first flow channels extending from the first ventilation side to the second ventilation side; a second porous heat dissipation element connected to the first heat source; a second porous heat dissipation element having a third ventilation side, a fourth ventilation side and a plurality of second flow channels, the third ventilation side and the fourth ventilation side are opposite to each other, and the second flow channels extend from the third ventilation side to the fourth ventilation side; a third porous heat dissipation element connected to the third heat source, the third porous heat dissipation element having a fifth ventilation side, a sixth ventilation side and a plurality of third flow channels, the fifth ventilation side and The third flow channels extend from the fifth ventilating side to the sixth ventilating side; a first flow guide pipe connects the second ventilating side and the fifth ventilating side and communicates with the first flow channels and the third flow channels; and a second flow guide pipe connects the fourth ventilating side and the sixth ventilating side and communicates with the second flow channels and the third flow channels; wherein the first porous heat dissipation element and the second porous heat dissipation element are connected to each other. The third porous heat dissipation element is opposite to the first porous heat dissipation element, and the third porous heat dissipation element is located between the first porous heat dissipation element and the second porous heat dissipation element. The third porous heat dissipation element further has a third side wall and a seventh ventilation side opposite to each other. The third side wall and the seventh ventilation side are connected between the fifth ventilation side and the sixth ventilation side. The seventh ventilation side has a plurality of vents, and the vents are connected to the third flow channels. As described in claim 9, the third porous heat dissipation element further has a fourth side wall and a fifth side wall opposite to each other, the fourth side wall and the fifth side wall are connected between the fifth ventilation side and the sixth ventilation side, and are connected with the third side wall and the seventh ventilation side to form an airflow space. The vents include a plurality of ventilation gaps, and in a direction from the fourth side wall to the fifth side wall, the width of the ventilation gaps is smaller than the width of the third flow channels. The lighting device as described in claim 9, wherein the third side wall has a first surface and a second surface opposite to each other, the third heat source is disposed on the first surface, and the fifth ventilation side, the sixth ventilation side and the third flow channels are located on part or all of the second surface. The lighting device as described in claim 11, wherein the third flow channels are located on part of the second surface, the third porous heat dissipation element includes a first heat dissipation block and a second heat dissipation block, the fifth ventilation side and part of the third flow channels are located in the first heat dissipation block, the sixth ventilation side and another part of the third flow channels are located in the second heat dissipation block, and in a direction from the fifth ventilation side to the sixth ventilation side, the first heat dissipation block and the second heat dissipation block are separated from each other. The lighting device as described in claim 9 further includes a fan disposed on the first ventilation side, the third ventilation side and/or the seventh ventilation side. The lighting device as described in claim 13 further includes a third air guide tube, wherein the fan is at least disposed on the seventh ventilation side, and the third air guide tube is connected to the fan and the ventilation openings. A lighting device includes: a first heat source, a second heat source and a third heat source; a first porous heat dissipation element connected to the first heat source, the first porous heat dissipation element having a first ventilation side, a second ventilation side and a plurality of first flow channels, the first ventilation side and the second ventilation side are opposite to each other, and the first flow channels extend from the first ventilation side to the second ventilation side; a second porous heat dissipation element connected to the second heat source, the second porous heat dissipation element having a third ventilation side, a fourth ventilation side and a plurality of second flow channels, the third ventilation side and the fourth ventilation side are opposite to each other, and the second flow channels extend from the third ventilation side to the fourth ventilation side. ; a third porous heat dissipation element connected to the third heat source, the third porous heat dissipation element having a fifth ventilation side, a sixth ventilation side and a plurality of third flow channels, the fifth ventilation side and the sixth ventilation side are opposite, and the third flow channels extend from the fifth ventilation side to the sixth ventilation side; a first air guide tube connected to the second ventilation side and the fifth ventilation side, and communicated with the first flow channels and the third flow channels; and a second air guide tube connected to the fourth ventilation side and the sixth ventilation side, and communicated with the second flow channels and the third flow channels; the lighting device further includes a fan disposed on the first ventilation side and/or the third ventilation side. A lighting device, comprising: a first heat source, a second heat source and a third heat source; a first porous heat dissipation element connected to the first heat source, the first porous heat dissipation element having a first ventilation side, a second ventilation side and a plurality of first flow channels, the first ventilation side and the second ventilation side are opposite, and the first flow channels extend from the first ventilation side to the second ventilation side; a second porous heat dissipation element connected to the second heat source, the second porous heat dissipation element having a third ventilation side, a fourth ventilation side and a plurality of second flow channels, the third ventilation side and the fourth ventilation side are opposite, and the second flow channels extend from the third ventilation side to the fourth ventilation side; a third porous heat dissipation element connected to the second heat source, the second porous heat dissipation element having a third ventilation side, a fourth ventilation side and a plurality of second flow channels, the third ventilation side and the fourth ventilation side are opposite, and the second flow channels extend from the third ventilation side to the fourth ventilation side; The third heat source, the third porous heat dissipation element has a fifth ventilation side, a sixth ventilation side and a plurality of third flow channels, the fifth ventilation side and the sixth ventilation side are opposite to each other, and the third flow channels extend from the fifth ventilation side to the sixth ventilation side; a first air guide tube, connecting the second ventilation side and the fifth ventilation side, and communicating with the first flow channels and the third flow channels; and a second air guide tube, connecting the fourth ventilation side and the sixth ventilation side, and communicating with the second flow channels and the third flow channels; wherein the first air guide tube and the second air guide tube respectively have a bending portion, and the bending portions respectively have a plurality of heat dissipation fins, wherein the heat dissipation fins are arranged through the bending portions. A lighting device includes: a first heat source, a second heat source and a third heat source; a first porous heat dissipation element connected to the first heat source, the first porous heat dissipation element having a first ventilation side, a second ventilation side and a plurality of first flow channels, the first ventilation side and the second ventilation side are opposite, and the first flow channels extend from the first ventilation side to the second ventilation side; a second porous heat dissipation element connected to the second heat source, the second porous heat dissipation element having a third ventilation side, a fourth ventilation side and a plurality of second flow channels, the third ventilation side and the fourth ventilation side are opposite, and the second flow channels extend from the third ventilation side to the fourth ventilation side; a third porous heat dissipation element connected to the third heat source, the third porous heat dissipation element having a first ventilation side, a second ventilation side and a plurality of second flow channels, the third ventilation side and the fourth ventilation side are opposite, and the second flow channels extend from the third ventilation side to the fourth ventilation side. A fifth ventilation side, a sixth ventilation side and a plurality of third flow channels, the fifth ventilation side and the sixth ventilation side are opposite to each other, and the third flow channels extend from the fifth ventilation side to the sixth ventilation side; a first air guide tube, connecting the second ventilation side and the fifth ventilation side, and communicating with the first flow channels and the third flow channels; and a second air guide tube, connecting the fourth ventilation side and the sixth ventilation side, and communicating with the second flow channels and the third flow channels; the lighting device further includes a heat dissipation layer, wherein the heat dissipation layer is disposed in all of the first flow channels, all of the second flow channels and all of the third flow channels, or disposed in part of the first flow channels, part of the second flow channels and part of the third flow channels. A lighting device comprises: a first heat source, a second heat source and a third heat source; a first porous heat dissipation element connected to the first heat source, the first porous heat dissipation element having a first ventilation side, a second ventilation side and a plurality of first flow channels, the first ventilation side and the second ventilation side are opposite to each other, and the first flow channels extend from the first ventilation side to the second ventilation side; a second porous heat dissipation element connected to the second heat source The second porous heat dissipation element has a third ventilation side, a fourth ventilation side and a plurality of second flow channels, the third ventilation side and the fourth ventilation side are opposite to each other, and the second flow channels extend from the third ventilation side to the fourth ventilation side; a third porous heat dissipation element is connected to the third heat source, the third porous heat dissipation element has a fifth ventilation side, a sixth ventilation side and a plurality of third flow channels, the fifth ventilation side and the sixth ventilation side are opposite to each other, and the second flow channels extend from the third ventilation side to the fourth ventilation side; The third flow channels extend from the fifth ventilation side to the sixth ventilation side; a first flow guide tube connects the second ventilation side and the fifth ventilation side and communicates with the first flow channels and the third flow channels; and a second flow guide tube connects the fourth ventilation side and the sixth ventilation side and communicates with the second flow channels and the third flow channels; the lighting device further includes a first heat conducting member, a second heat conducting member, A third heat conductor and a heat conductive layer, the first heat conductor is fixed to the first porous heat dissipation element, the second heat conductor is fixed to the second porous heat dissipation element, the third heat conductor is fixed to the third porous heat dissipation element, and the heat conductive layer is arranged between the first heat conductor and the first porous heat dissipation element, between the second heat conductor and the second porous heat dissipation element, and between the third heat conductor and the third porous heat dissipation element. A projection device comprises: an illumination device, a display element and a projection lens, wherein the illumination device is used to provide an illumination beam, the illumination device comprises: a first heat source, a second heat source and a third heat source; a first porous heat dissipation element connected to the first heat source, the first porous heat dissipation element having a first ventilation side, a second ventilation side and a plurality of first flow channels, the first ventilation side and the second ventilation side being opposite to each other, The first flow channels extend from the first ventilation side to the second ventilation side; a second porous heat dissipation element is connected to the second heat source, the second porous heat dissipation element has a third ventilation side, a fourth ventilation side and a plurality of second flow channels, the third ventilation side and the fourth ventilation side are opposite, the second flow channels extend from the third ventilation side to the fourth ventilation side; a third porous heat dissipation element is connected to the third heat source, the third porous heat dissipation element It has a fifth ventilation side, a sixth ventilation side and a plurality of third flow channels, the fifth ventilation side and the sixth ventilation side are opposite to each other, and the third flow channels extend from the fifth ventilation side to the sixth ventilation side; a first flow guide pipe, connecting the second ventilation side and the fifth ventilation side, and communicating with the first flow channels and the third flow channels; and a second flow guide pipe, connecting the fourth ventilation side and the sixth ventilation side, and communicating with the second flow channels and the third flow channels, wherein the first ventilation side of the first porous heat dissipation element and the third ventilation side of the second porous heat dissipation element are suitable for air flow; the display element is located on a transmission path of the illumination beam and is used to receive the illumination beam and convert the illumination beam into an image beam; and the projection lens is located on a transmission path of the image beam and is used to project the image beam out of the projection device.

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