Heat dissipation device and projection device

Abstract

The application discloses a heat dissipation device and a projection device. The heat dissipation device comprises a shell and a piezoelectric mechanism. The shell is provided with an air inlet channel on a first side and an air outlet channel on a second side. The air inlet channel and the air outlet channel both have an open state and a closed state. The piezoelectric mechanism is arranged between the air inlet channel and the air outlet channel, and a cavity is formed in the piezoelectric mechanism. Part of the structure of the piezoelectric mechanism can be deformed under the condition of power-on and make the piezoelectric mechanism have a first state and a second state. In the first state, the volume of the cavity increases, the air inlet channel is in the open state, and the air outlet channel is in the closed state. The gas enters the cavity from the external environment through the air inlet channel. In the second state, the volume of the cavity decreases, the air inlet channel is in the closed state, and the air outlet channel is in the open state. The gas flows out of the cavity through the air outlet channel.

Description

Technical Field

[0001] This application relates to the field of optical product technology, and more specifically, to a heat dissipation device and a projection device. Background Technology

[0002] With the emergence of the metaverse concept, smart head-mounted devices, as important interface devices for the metaverse, have experienced rapid development in recent years. Smart head-mounted devices typically include a projection engine, which primarily serves for illumination and imaging. While smart head-mounted devices and their projection engines are rapidly becoming smaller and more functionally diverse, this has also led to increased heat generation.

[0003] Especially for AR smart glasses, which are smaller in size and generate more concentrated heat, their compact structure and product form make it difficult to use traditional fans for active cooling. Therefore, current technologies mostly use composite graphite sheets, a material with high thermal conductivity, for passive cooling of AR smart glasses; however, the cooling effect of passive cooling is often unsatisfactory.

[0004] In view of this, it is necessary to propose a new technical solution to solve the above-mentioned technical problems. Summary of the Invention

[0005] One objective of this application is to provide a new technical solution for a heat dissipation device and a projection device.

[0006] According to a first aspect of this application, a heat dissipation device is provided, the heat dissipation device comprising:

[0007] The housing has an air inlet duct on its first side and an air outlet duct on its second side; both the air inlet duct and the air outlet duct have an open state and a closed state.

[0008] A piezoelectric mechanism is disposed between the air inlet duct and the air outlet duct, and a cavity is formed within the piezoelectric mechanism;

[0009] A portion of the piezoelectric mechanism can deform when energized, giving the piezoelectric mechanism a first state and a second state.

[0010] In the first state, the volume of the cavity increases, the air inlet is open and the air outlet is closed, and gas enters the cavity from the external environment through the air inlet; in the second state, the volume of the cavity decreases, the air inlet is closed and the air outlet is open, and gas flows out of the cavity through the air outlet.

[0011] Optionally, the piezoelectric mechanism includes a support frame, a first piezoelectric component, and a second piezoelectric component, wherein the first piezoelectric component and the second piezoelectric component are installed on the support frame at a distance from each other, and the cavity is formed between the first piezoelectric component and the second piezoelectric component.

[0012] Optionally, the first piezoelectric component includes a first piezoelectric block and a first spring, wherein the first piezoelectric block is connected to one side of the first spring;

[0013] The second piezoelectric component includes a second piezoelectric block and a second spring, wherein the second piezoelectric block is connected to one side of the second spring;

[0014] The first piezoelectric block and the second piezoelectric block are arranged opposite to each other;

[0015] In the first state, the first piezoelectric block and the second piezoelectric block deform and contract, and the first and second spring sheets move away from each other to increase the volume of the cavity; in the second state, the first piezoelectric block and the second piezoelectric block deform and stretch, and the first and second spring sheets move closer to each other to decrease the volume of the cavity.

[0016] Optionally, the first piezoelectric component further includes a first positive electrode and a first negative electrode, wherein the first positive electrode and the first negative electrode are electrically connected to the first piezoelectric block.

[0017] Optionally, the first spring is made of a conductive material, and one of the first positive electrode and the first negative electrode is electrically connected to the first piezoelectric block through the first spring.

[0018] Optionally, the second piezoelectric component further includes a second positive electrode and a second negative electrode, the second positive electrode and the second negative electrode being electrically connected to the second piezoelectric block respectively.

[0019] Optionally, the second spring is made of a conductive material, and one of the second positive electrode and the second negative electrode is electrically connected to the second piezoelectric block through the second spring.

[0020] Optionally, the housing includes a first sub-shell, a second sub-shell, and a first baffle, wherein the first sub-shell is connected to a first side of the piezoelectric mechanism, and the second sub-shell is disposed on the side of the first sub-shell away from the piezoelectric mechanism;

[0021] The first sub-shell has a first ventilation hole, and the first sub-shell has a first protrusion protruding from the second sub-shell next to the first ventilation hole; the second sub-shell has a second ventilation hole, and the first ventilation hole and the second ventilation hole together form the air inlet channel;

[0022] The first baffle is disposed between the first sub-shell and the second sub-shell; when the first baffle abuts against the first boss, the air inlet is in the open state; when the first baffle abuts against the second sub-shell and covers the second ventilation hole, the air inlet is in the closed state.

[0023] Optionally, the outer casing includes a third sub-shell, a fourth sub-shell, and a second baffle. The third sub-shell is connected to the second side of the piezoelectric mechanism, and the fourth sub-shell is disposed on the side of the third sub-shell away from the piezoelectric mechanism.

[0024] The third sub-shell has a third ventilation hole, the fourth sub-shell has a fourth ventilation hole, and the fourth sub-shell protrudes from the third sub-shell next to the fourth ventilation hole to form a second protrusion; the third ventilation hole and the fourth ventilation hole together form the air outlet duct;

[0025] The second baffle is disposed between the third sub-shell and the fourth sub-shell; when the second baffle abuts against the second boss, the air outlet is in the open state; when the second baffle abuts against the third sub-shell and covers the third ventilation hole, the air outlet is in the closed state.

[0026] According to a second aspect of this application, a projection device is provided, the projection device including a heat dissipation device and a projection optical engine as described in the first aspect, the projection optical engine including a heat-generating device, and the air outlet of the heat dissipation device being disposed directly opposite the heat-generating device.

[0027] In the heat dissipation device provided in this application embodiment, the air outlet effect is achieved by setting a piezoelectric mechanism. It does not contain rotating parts and impeller structure, which greatly simplifies the structure of the heat dissipation device and is conducive to miniaturization design.

[0028] Other features and advantages of this application will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0029] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of the present application and, together with their description, serve to explain the principles of the present application.

[0030] Figure 1 The figure shown is a schematic diagram of the overall structure of a heat dissipation device according to this application;

[0031] Figure 2 The diagram shown is an exploded view of a heat dissipation device according to this application.

[0032] Figure 3 The diagram shown is a structural schematic of the piezoelectric mechanism in a heat dissipation device according to this application;

[0033] Figure 4a The diagram shown is a structural schematic of the first piezoelectric component in a heat dissipation device according to this application;

[0034] Figure 4b The diagram shown is a schematic diagram of the structure of the second piezoelectric component in a heat dissipation device according to this application;

[0035] Figure 5a The diagram shown illustrates the working state of the piezoelectric mechanism in a heat dissipation device according to this application. Figure 1 ;

[0036] Figure 5b The diagram shown illustrates the working state of the piezoelectric mechanism in a heat dissipation device according to this application. Figure 2 ;

[0037] Figure 5c The diagram shown illustrates the working state of the piezoelectric mechanism in a heat dissipation device according to this application. Figure 3 ;

[0038] Figure 6a The figure shown is a top view of a heat dissipation device according to this application;

[0039] Figure 6b The diagram shows the working state of the first baffle and the second baffle in a heat dissipation device according to this application. Figure 1 ;

[0040] Figure 6c The diagram shows the working state of the first baffle and the second baffle in a heat dissipation device according to this application. Figure 2 ;

[0041] Figure 7 The diagram shown is a structural schematic of a projection device according to this application.

[0042] Explanation of reference numerals in the attached figures:

[0043] 1. Heat dissipation device; 11. Outer shell; 111. First sub-shell; 1111. First ventilation hole; 1112. First boss; 112. Second sub-shell; 1121. Second ventilation hole; 113. First baffle; 114. Third sub-shell; 1141. Third ventilation hole; 115. Fourth sub-shell; 1151. Fourth ventilation hole; 1152. Second boss; 1153. Protrusion; 116. Second baffle; 101. Gap; 12. Piezoelectric mechanism; 100. Cavity 120. Support frame; 121. First piezoelectric assembly; 1211. First piezoelectric block; 1212. First spring; 1213. First positive electrode; 1214. First negative electrode; 1215. First conductive element; 1216. First insulating layer; 122. Second piezoelectric assembly; 1221. Second piezoelectric block; 1222. Second spring; 1223. Second positive electrode; 1224. Second negative electrode; 1225. Second conductive element; 1226. Second insulating layer;

[0044] 2. Projection optical engine; 21. Heating device. Detailed Implementation

[0045] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present application.

[0046] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the scope of this application and its application or use.

[0047] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0048] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0049] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0050] Reference Figures 1-6c As shown, according to one embodiment of this application, a heat dissipation device 1 is provided. The heat dissipation device 1 includes a housing 11 and a piezoelectric mechanism 12. The housing 11 has an air inlet duct on its first side and an air outlet duct on its second side. Both the air inlet duct and the air outlet duct have an open state and a closed state.

[0051] The piezoelectric mechanism 12 is disposed between the air inlet duct and the air outlet duct, and a cavity 100 is formed inside the piezoelectric mechanism 12; a portion of the structure of the piezoelectric mechanism 12 can deform when energized, and the piezoelectric mechanism 12 can have a first state and a second state.

[0052] In the first state, the volume of the cavity 100 increases, the air inlet is open and the air outlet is closed, and gas enters the cavity 100 from the external environment through the air inlet; in the second state, the volume of the cavity 100 decreases, the air inlet is closed and the air outlet is open, and gas flows out of the cavity 100 through the air outlet.

[0053] In the heat dissipation device provided in this application embodiment, the deformation characteristics of the piezoelectric mechanism 12 under the action of electricity are utilized, and the air inlet and outlet channels are opened or closed to form gas flow in the cavity 100, so that the heat dissipation device 1 can achieve the effect of air outlet, thereby achieving the purpose of active heat dissipation for the heat-generating devices of the projection equipment.

[0054] Specifically, when the piezoelectric mechanism 12 is energized and in the first state, the volume of the cavity 100 increases, the air pressure inside the cavity 100 decreases, and since the air inlet is open and the air outlet is closed, gas enters the cavity 100 from the external environment through the air inlet. When the piezoelectric mechanism 12 is energized and in the second state, the volume of the cavity 100 decreases, the air pressure inside the cavity 100 increases, and since the air inlet is closed and the air outlet is open, gas flows out of the cavity 100 through the air outlet.

[0055] By controlling the energization state of the piezoelectric mechanism 12, for example by applying an alternating electrical signal to the piezoelectric mechanism 12, the piezoelectric mechanism 12 repeatedly switches between a first state and a second state; thereby causing the cavity 100 to repeatedly intake and exhaust air, so that the heat dissipation device 1 can provide a continuous airflow for active heat dissipation of the heat-generating device that needs heat dissipation.

[0056] In the heat dissipation device provided in this application embodiment, the air outlet effect is achieved by setting a piezoelectric mechanism 12. It does not contain rotating parts and impeller structure, which greatly simplifies the structure of the heat dissipation device and facilitates miniaturization design. Thus, the heat dissipation device can be applied to AR smart glasses.

[0057] Reference Figure 3 As shown, in one embodiment, the piezoelectric mechanism 12 includes a support frame 120, a first piezoelectric component 121 and a second piezoelectric component 122, the first piezoelectric component 121 and the second piezoelectric component 122 are installed at a distance from each other on the support frame 120, and the cavity 100 is formed between the first piezoelectric component 121 and the second piezoelectric component 122.

[0058] In this specific example, the first piezoelectric component 121 and the second piezoelectric component 122 are mounted on the support frame 120, which provides support for the first piezoelectric component 121 and the second piezoelectric component 122. Optionally, the support frame 120 is rectangular or cubic, so that the shape and structure of the piezoelectric mechanism 12 are relatively regular, which helps to reduce the space occupied by the piezoelectric mechanism 12.

[0059] Reference Figure 4a , Figure 4b As shown, in one embodiment, the first piezoelectric component 121 includes a first piezoelectric block 1211 and a first spring 1212, wherein the first piezoelectric block 1211 is connected to one side of the first spring 1212;

[0060] The second piezoelectric component 122 includes a second piezoelectric block 1221 and a second spring 1222, wherein the second piezoelectric block 1221 is connected to one side of the second spring 1222;

[0061] The first piezoelectric block 1211 and the second piezoelectric block 1221 are arranged opposite to each other;

[0062] Reference Figure 5a and Figure 5b As shown, in the first state, the first piezoelectric block 1211 and the second piezoelectric block 1221 deform and contract, and the first spring piece 1212 and the second spring piece 1222 move away from each other to increase the volume of the cavity 100; in the second state, the first piezoelectric block 1211 and the second piezoelectric block 1221 deform and stretch, and the first spring piece 1212 and the second spring piece 1222 move closer to each other to decrease the volume of the cavity 100.

[0063] In this specific example, the first piezoelectric block 1211 is disposed on the side of the first spring 1212 near the second spring 1222, and the second piezoelectric block 1221 is disposed on the side of the second spring 1222 near the first spring 1212; the first piezoelectric block 1211 and the second piezoelectric block 1221 can deform when energized.

[0064] Specifically, in the first state, the first piezoelectric block 1211 and the second piezoelectric block 1221 deform and contract in a direction perpendicular to the polarization direction under the action of the electric field. For the first piezoelectric block 1211, its deformation and contraction cause the side of the first spring piece 1212 connected to it close to the second spring piece 1222 to also deform and contract. The other side of the first spring piece 1212 away from the second spring piece 1222 is not affected by the first piezoelectric block 1211, so the two sides of the first spring piece 1212 are unbalanced in force, so the first spring piece 1212 bends and moves in a direction away from the second spring piece 1222.

[0065] The deformation and contraction of the second piezoelectric block 1221 causes the side of the second spring 1222 connected to it near the first spring 1212 to also deform and contract. Meanwhile, the other side of the second spring 1222, away from the first spring 1212, is not affected by the second piezoelectric block 1221, resulting in an imbalance of forces on both sides of the second spring 1222. This causes the second spring 1222 to bend and move away from the first spring 1212. Therefore, the first spring 1212 and the second spring 1222 move further apart, thereby increasing the volume of the cavity 100.

[0066] Reference Figure 5c As shown, in the second state, the first piezoelectric block 1211 and the second piezoelectric block 1221 are deformed and stretched in a direction perpendicular to the polarization direction under the action of the electric field. For the first piezoelectric block 1211, its deformation and stretching cause the side of the first spring piece 1212 connected to it that is close to the second spring piece 1222 to also be deformed and stretched. The other side of the first spring piece 1212 that is away from the second spring piece 1222 is not affected by the first piezoelectric block 1211, so the two sides of the first spring piece 1212 are unbalanced in terms of force, so the first spring piece 1212 bends and moves toward the direction closer to the second spring piece 1222.

[0067] The deformation and stretching of the second piezoelectric block 1221 causes the side of the second spring piece 1222 connected to it near the first spring piece 1212 to also deform and stretch. Meanwhile, the other side of the second spring piece 1222, away from the first spring piece 1212, is not affected by the second piezoelectric block 1221, resulting in an imbalance of forces on both sides of the second spring piece 1222. This causes the second spring piece 1222 to bend and move towards the first spring piece 1212. Therefore, the first spring piece 1212 and the second spring piece 1222 move closer to each other, thereby reducing the volume of the cavity 100.

[0068] Reference Figure 4a As shown, in one embodiment, the first piezoelectric component 121 further includes a first positive electrode 1213 and a first negative electrode 1214, the first positive electrode 1213 and the first negative electrode 1214 being electrically connected to the first piezoelectric block 1211 respectively.

[0069] In this specific example, the first positive electrode 1213 and the first negative electrode 1214 are electrically connected to the first piezoelectric block 1211, thereby providing an alternating electrical signal to the first piezoelectric block 1211, so that the first piezoelectric block 1211 repeatedly switches between deformation contraction and deformation stretching.

[0070] Optionally, the first spring 1212 is made of a conductive material, and one of the first positive electrode 1213 and the first negative electrode 1214 is electrically connected to the first piezoelectric block 1211 through the first spring 1212.

[0071] In this specific example, the first spring 1212 is, for example, a metal spring, which can both deform in accordance with the first piezoelectric block 1211 to change the volume of the cavity 100, and, due to its conductivity, can act as an electrical conductor to connect one of the first positive electrode 1213 and the first negative electrode 1214 to the first piezoelectric block 1211. For example, the first negative electrode 1214 is electrically connected to the first piezoelectric block 1211 through the first spring 1212; while the first positive electrode 1213 is electrically connected to the first piezoelectric block 1211 through the first conductive element 1215. Furthermore, a first insulating layer 1216 is provided between the first spring 1212 and the first conductive element 1215 to electrically isolate the first spring 1212 and the first conductive element 1215.

[0072] Reference Figure 4b As shown, in one embodiment, the second piezoelectric component 122 further includes a second positive electrode 1223 and a second negative electrode 1224, the second positive electrode 1223 and the second negative electrode 1224 being electrically connected to the second piezoelectric block 1221 respectively.

[0073] In this specific example, the second positive electrode 1223 and the second negative electrode 1224 are electrically connected to the second piezoelectric block 1221, thereby providing an alternating electrical signal to the second piezoelectric block 1221, so that the second piezoelectric block 1221 repeatedly switches between deformation contraction and deformation stretching.

[0074] Optionally, the second spring 1222 is made of a conductive material, and one of the second positive electrode 1223 and the second negative electrode 1224 is electrically connected to the second piezoelectric block 1221 through the second spring 1222.

[0075] In this specific example, the second spring 1222 is, for example, a metal spring, which can both deform in accordance with the second piezoelectric block 1221 to change the volume of the cavity 100, and, due to its conductivity, can act as an electrical conductor to connect one of the second positive electrode 1223 and the second negative electrode 1224 to the second piezoelectric block 1221. For example, the second negative electrode 1224 is electrically connected to the second piezoelectric block 1221 through the second spring 1222; while the second positive electrode 1223 is electrically connected to the second piezoelectric block 1221 through the second conductive element 1225. Furthermore, a second insulating layer 1226 is provided between the second spring 1222 and the second conductive element 1225 to electrically isolate the second spring 1222 from the second conductive element 1225.

[0076] In the piezoelectric mechanism 12, the first piezoelectric block 1211 and the second piezoelectric block 1221 are symmetrically arranged, as are the first spring 1212 and the second spring 1222. When the piezoelectric mechanism 12 is operating normally, the operating frequency of the first spring 1212 and the second spring 1222 is consistent with the amplitude. The first spring 1212 and the second spring 1222 can cancel each other out the vibration caused by inertial force, ensuring that the piezoelectric mechanism 12 does not generate significant noise. At the same time, by controlling the frequency of the alternating electrical signal to control the operating frequency of the first spring 1212 and the second spring 1222, they can be made to operate outside the audible frequency range of the human ear, thereby further controlling the generation of noise.

[0077] Reference Figure 3 As shown, in one embodiment, the first positive electrode 1213, the first negative electrode 1214, the second positive electrode 1223, and the second negative electrode 1224 are all mounted on the side of the support frame 120. This facilitates the series or parallel connection of multiple piezoelectric mechanisms 12, allowing for modular configuration based on usage requirements and heat dissipation needs, and the number of piezoelectric mechanisms 12 can be freely increased or decreased. For example, when the surface area of ​​the heat-generating device is large, two or three piezoelectric mechanisms 12 can be connected in series to improve heat dissipation efficiency.

[0078] Reference Figure 2 As shown, in one embodiment, the outer shell 11 includes a first sub-shell 111, a second sub-shell 112, and a first baffle 113. The first sub-shell 111 is connected to a first side of the piezoelectric mechanism 12, and the second sub-shell 112 is disposed on the side of the first sub-shell 111 away from the piezoelectric mechanism 12.

[0079] The first sub-shell 111 has a first ventilation hole 1111, and the first sub-shell 111 has a first boss 1112 protruding from the second sub-shell 112 next to the first ventilation hole 1111; the second sub-shell 112 has a second ventilation hole 1121, and the first ventilation hole 1111 and the second ventilation hole 1121 together form the air inlet channel.

[0080] The first baffle 113 is disposed between the first sub-shell 111 and the second sub-shell 112; when the first baffle 113 abuts against the first boss 1112, the air inlet is in an open state; when the first baffle 113 abuts against the second sub-shell 112 and covers the second ventilation hole 1121, the air inlet is in a closed state.

[0081] Reference Figure 2 As shown, in one embodiment, the outer shell 11 includes a third sub-shell 114, a fourth sub-shell 115, and a second baffle 116. The third sub-shell 114 is connected to the second side of the piezoelectric mechanism 12, and the fourth sub-shell 115 is disposed on the side of the third sub-shell 114 away from the piezoelectric mechanism 12.

[0082] The third sub-shell 114 has a third ventilation hole 1141, the fourth sub-shell 115 has a fourth ventilation hole 1151, and the fourth sub-shell 115 has a second boss 1152 protruding from the third sub-shell 114 next to the fourth ventilation hole 1151; the third ventilation hole 1141 and the fourth ventilation hole 1151 together form the air outlet duct;

[0083] The second baffle 116 is disposed between the third sub-shell 114 and the fourth sub-shell 115; when the second baffle 116 abuts against the second boss 1152, the air outlet is in the open state; when the second baffle 116 abuts against the third sub-shell 114 and covers the third ventilation hole 1141, the air outlet is in the closed state.

[0084] In this specific example, an air inlet duct communicating with the cavity 100 is formed from the second ventilation hole 1121 to the first ventilation hole 1111; and an air outlet duct communicating with the cavity 100 is formed from the third ventilation hole 1141 to the fourth ventilation hole 1151.

[0085] Reference Figure 6a and Figure 6bAs shown, in the first state, the first piezoelectric block 1211 and the second piezoelectric block 1221 deform and contract, and the first spring 1212 and the second spring 1222 move away from each other to increase the volume of the cavity 100 and decrease the air pressure inside the cavity 100; thus, under the action of the pressure difference between the inside and outside of the cavity 100, the first baffle 113 and the second baffle 116 are both pushed toward the inside of the cavity 100. The second baffle 116 moves toward the inside of the cavity 100 and abuts against the third sub-shell 114, covering the third ventilation hole 1141. In this way, the gas in the cavity 100 cannot reach the air outlet, that is, the air outlet is in a closed state. The first baffle 113 moves toward the inside of the cavity 100 and abuts against the first protrusion 1112. Since the first protrusion 1112 is set to protrude toward the second sub-shell 112 next to the first ventilation hole 1111, the first baffle 113 abuts against the first protrusion 1112 and does not cover the first ventilation hole 1111. A gap is formed between the first baffle 113 and the first ventilation hole 1111, which communicates with the cavity 100. External gas can first pass through the second ventilation hole 1121 and then enter the cavity 100 through the gap between the first baffle 113 and the first ventilation hole 1111, that is, the air inlet is in an open state.

[0086] Reference Figure 6c As shown, in the second state, the first piezoelectric block 1211 and the second piezoelectric block 1221 are deformed and stretched, and the first spring 1212 and the second spring 1222 move closer to each other to make the volume of the cavity 100 smaller and the air pressure inside the cavity 100 increase; thus, under the action of the pressure difference between the inside and outside of the cavity 100, the first baffle 113 and the second baffle 116 are both pushed toward the outside of the cavity 100. The first baffle 113 moves toward the outside of the cavity 100 and abuts against the second sub-shell 112 and covers the second ventilation hole 1121. This prevents outside gas from entering the cavity 100 through the air inlet, meaning the air inlet is closed. The second baffle 116 moves toward the outside of the cavity 100 and abuts against the second protrusion 1152. Since the second protrusion 1152 protrudes toward the third sub-shell 114 next to the fourth ventilation hole 1151, the second baffle 116 abutting against the second protrusion 1152 will not cover the fourth ventilation hole 1151. A gap is formed between the second baffle 116 and the fourth ventilation hole 1151 that communicates with the cavity 100. Gas inside the cavity 100 can first pass through the third ventilation hole 1141 and then flow out of the cavity 100 through the gap between the second baffle 116 and the fourth ventilation hole 1151, meaning the air outlet is open.

[0087] Reference Figure 7 As shown, according to another embodiment of this application, a projection device is provided, the projection device including a heat dissipation device 1 and a projection optical engine 2 as described above, the projection optical engine 2 including a heat-generating device 21, and the air outlet of the heat dissipation device 1 being disposed directly opposite the heat-generating device 21.

[0088] The projection device provided in this embodiment employs the aforementioned heat dissipation device 1, which does not include rotating parts or an impeller structure. The heat dissipation device 1 has a simple structure and small size, which is beneficial for the miniaturization design of the projection device. The heat-generating device 21 can be, for example, an LED light source. As the light source of the entire projection device, the LED light source works in conjunction with the sequential emission of the LCoS module to produce the image. It is also the largest heat source. Due to the working characteristics of the LED light source, its luminous efficiency decreases as the temperature rises, resulting in a decrease in brightness, which will seriously reduce the projection quality. At the same time, the high temperature generated by the LED light source will also greatly reduce the lifespan of surrounding components and the LED itself.

[0089] The air outlet of the heat dissipation device 1 is positioned directly opposite the heat-generating device 21, so that the airflow coming out of the cavity 100 of the heat dissipation device 1 can be blown vertically toward the heat-generating device 21, thereby reducing the boundary layer effect generated between the airflow and the heat-generating device and improving the heat dissipation efficiency.

[0090] Optionally, a protrusion 1153 is formed on the side of the fourth sub-shell 115 away from the third sub-shell 114. For example, four protrusions 1153 are provided, and the four protrusions 1153 are respectively located at the four apex positions of the fourth sub-shell 115. This ensures that when the heat dissipation device 1 is installed in the projection device, in order to save space, the heat-generating device 21 (e.g., the back plate of the LED light source) is fitted to the protrusion 1153 of the fourth sub-shell 115, so that a gap 101 can still be formed between the heat-generating device 21 and the fourth sub-shell 115, thereby ensuring that the airflow from the cavity 100 can blow towards the heat-generating device 21.

[0091] While specific embodiments of this application have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of this application. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of this application. The scope of this application is defined by the appended claims.

Claims

1. A heat dissipation device, characterized in that, The heat dissipation device includes: The outer casing (11) has an air inlet duct on its first side and an air outlet duct on its second side; both the air inlet duct and the air outlet duct have an open state and a closed state. A piezoelectric mechanism (12) is disposed between the air inlet duct and the air outlet duct, and a cavity (100) is formed inside the piezoelectric mechanism (12). Part of the structure of the piezoelectric mechanism (12) can deform when energized, giving the piezoelectric mechanism (12) a first state and a second state; In the first state, the volume of the cavity (100) increases, the air inlet is open and the air outlet is closed, and gas enters the cavity (100) from the external environment through the air inlet; in the second state, the volume of the cavity (100) decreases, the air inlet is closed and the air outlet is open, and gas flows out of the cavity (100) through the air outlet. The piezoelectric mechanism (12) includes a first piezoelectric component (121) and a second piezoelectric component (122). The first piezoelectric component (121) includes a first piezoelectric block (1211) and a first spring (1212). The second piezoelectric component (122) includes a second piezoelectric block (1221) and a second spring (1222). The first piezoelectric block (1211) and the second piezoelectric block (1221) are arranged opposite to each other. The outer casing (11) includes a first sub-shell (111), a second sub-shell (112), and a first baffle (113). The first sub-shell (111) is connected to the first side of the piezoelectric mechanism (12), and the second sub-shell (112) is disposed on the side of the first sub-shell (111) away from the piezoelectric mechanism (12). The first sub-shell (111) has a first ventilation hole (1111), and the first sub-shell (111) has a first boss (1112) protruding from the first ventilation hole (1111) toward the second sub-shell (112). The second sub-shell (112) has a second ventilation hole (1121), and the first ventilation hole (1111) and the second ventilation hole (1121) together form the air inlet. The first baffle (113) is disposed between the first sub-shell (111) and the second sub-shell (112). The outer casing (11) includes a third sub-shell (114), a fourth sub-shell (115), and a second baffle (116). The third sub-shell (114) is connected to the second side of the piezoelectric mechanism (12), and the fourth sub-shell (115) is disposed on the side of the third sub-shell (114) away from the piezoelectric mechanism (12). The third sub-shell (114) has a third ventilation hole (1141), and the fourth sub-shell (115) has a fourth ventilation hole (1151). The fourth sub-shell (115) has a second boss (1152) protruding from the fourth ventilation hole (1151) toward the third sub-shell (114). The third ventilation hole (1141) and the fourth ventilation hole (1151) together form the air outlet. The second baffle (116) is disposed between the third sub-shell (114) and the fourth sub-shell (115).

2. The heat dissipation device according to claim 1, characterized in that, The piezoelectric mechanism (12) includes a support frame (120), the first piezoelectric component (121) and the second piezoelectric component (122) are installed at a distance from each other on the support frame (120), and the cavity (100) is formed between the first piezoelectric component (121) and the second piezoelectric component (122).

3. The heat dissipation device according to claim 2, characterized in that, The first piezoelectric block (1211) is connected to one side of the first spring (1212); The second piezoelectric block (1221) is connected to one side of the second spring (1222); In the first state, the first piezoelectric block (1211) and the second piezoelectric block (1221) deform and contract, and the first elastic piece (1212) and the second elastic piece (1222) move away from each other to increase the volume of the cavity (100); in the second state, the first piezoelectric block (1211) and the second piezoelectric block (1221) deform and stretch, and the first elastic piece (1212) and the second elastic piece (1222) move closer to each other to decrease the volume of the cavity (100).

4. The heat dissipation device according to claim 3, characterized in that, The first piezoelectric component (121) further includes a first positive electrode (1213) and a first negative electrode (1214), which are electrically connected to the first piezoelectric block (1211).

5. The heat dissipation device according to claim 4, characterized in that, The first spring (1212) is made of conductive material, and one of the first positive electrode (1213) and the first negative electrode (1214) is electrically connected to the first piezoelectric block (1211) through the first spring (1212).

6. The heat dissipation device according to claim 3, characterized in that, The second piezoelectric component (122) further includes a second positive electrode (1223) and a second negative electrode (1224), which are electrically connected to the second piezoelectric block (1221).

7. The heat dissipation device according to claim 6, characterized in that, The second spring (1222) is made of conductive material, and one of the second positive electrode (1223) and the second negative electrode (1224) is electrically connected to the second piezoelectric block (1221) through the second spring (1222).

8. The heat dissipation device according to claim 1, characterized in that, When the first baffle (113) abuts against the first boss (1112), the air inlet is in the open state; when the first baffle (113) abuts against the second sub-shell (112) and covers the second ventilation hole (1121), the air inlet is in the closed state.

9. The heat dissipation device according to claim 1 or 8, characterized in that, When the second baffle (116) abuts against the second boss (1152), the air outlet is in the open state; when the second baffle (116) abuts against the third sub-shell (114) and covers the third ventilation hole (1141), the air outlet is in the closed state.

10. A projection device, characterized in that, The projection device includes a heat dissipation device (1) and a projection optical engine (2) as described in any one of claims 1-9. The projection optical engine (2) includes a heat-generating device (21), and the air outlet of the heat dissipation device (1) is positioned directly opposite the heat-generating device (21).

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