A heat dissipation device for an LCD projector

Abstract

The present invention discloses a heat dissipation device for an LCD projector, and the LCD projector has a fully sealed optical engine. The heat dissipation device includes an LED light source radiator, a high-efficiency heat exchanger, an external fan, and a wind guide cover. A window for installing the high-efficiency heat exchanger is opened at the bottom of the housing of the fully sealed optical engine; the high-efficiency heat exchanger includes a buckle fin on the high-temperature heat absorption side, a partition plate, and a sunflower profile on the low-temperature heat dissipation side, and the buckle fin, the partition plate, and the sunflower profile are sequentially attached to each other. The buckle fin is located on the internal heat dissipation air duct of the fully sealed optical engine, and the partition plate seals the window opened at the bottom of the housing of the fully sealed optical engine for installing the high-efficiency heat exchanger. The present invention enables the high-efficiency heat exchanger to have indexes close to those of an ideal heat exchanger, the heat dissipation effect of the LCD light valve is better, and the product noise is lower, thereby allowing the projector to output higher brightness and obtain better durability, achieving positive effects.

Description

Technical Field

[0001] The present invention relates to the technical field of projectors, and in particular to a heat dissipation device for an LCD projector. Background Art

[0002] In recent years, more and more single-LCD projectors have sealed the optical system to form a fully-sealed optical engine, so as to solve a very big defect existing in past products, that is, the product quality is greatly affected by dust, and the optical performance durability is poor due to dust deposition. Since the most important input electric power of a single-LCD projector becomes Joule heat, the heat dissipation technology for the fully-sealed optical engine is still a relatively difficult and common problem in the industry.

[0003] Refer to the "fully-sealed semi-vertical LCD projection optical engine" described in Chinese Patent Publication No. CN113156754A, which is a representative product with relatively advanced current technology, and relatively innovative products such as the "air return heat exchange system and projector sealed optical engine" described in Chinese Patent Publication No. CN113448156A. However, the heat dissipation capabilities of these products are still inadequate, which seriously affects their market performance and user experience. Summary of the Invention

[0004] Based on the above problems, the purpose of the present invention is to significantly improve the heat dissipation level of the fully-sealed optical engine through technological innovation, thereby significantly improving the output brightness and durability of the projector and reducing the operating noise of the projector. The fully-sealed optical engine manufactured based on the heat dissipation device provided by the present invention will enable the projector product to achieve better market performance and user experience.

[0005] To achieve the above purpose, the present invention provides a heat dissipation device for an LCD projector, and the LCD projector has a fully-sealed optical engine. The heat dissipation device includes an LED light source radiator, a high-efficiency heat exchanger, an external fan, and a wind guide cover. A window for installing the high-efficiency heat exchanger is opened at the bottom of the housing of the fully-sealed optical engine. The high-efficiency heat exchanger includes a buckle Fin on the high-temperature heat absorption side, a partition plate, and a sunflower profile on the low-temperature heat dissipation side, and the buckle Fin, the partition plate, and the sunflower profile are sequentially attached to each other. The buckle Fin is located on the internal heat dissipation air duct of the fully-sealed optical engine, and the partition plate seals the window opened at the bottom of the housing of the fully-sealed optical engine for installing the high-efficiency heat exchanger. The air inlet of the external fan faces the sunflower profile, and there is a gap between the external fan and the sunflower profile. The air outlet of the external fan faces the LED light source radiator. The wind guide cover seals the gap between the air inlet of the external fan and the sunflower profile and encloses to form a first air duct. The wind guide cover seals the gap between the air outlet of the external fan and the LED light source radiator and encloses to form a second air duct.

[0006] Preferably, the external fan is a turbine fan.

[0007] Preferably, the rib surface of the sunflower profile is involute spiral.

[0008] Preferably, the involute spiral direction of the rib surface of the sunflower profile is opposite to the rotation direction of the external fan.

[0009] Furthermore, the number of the sunflower profiles is equal to the number of the external fans.

[0010] Positive effects of the present invention:

[0011] The high-efficiency heat exchanger of the present invention has performance indicators close to those of an ideal heat exchanger, enabling better heat dissipation of the LCD light valve and lower product noise. As a result, the projector can output higher brightness and achieve better durability, thus achieving positive effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0013] Figure 1 Schematic diagram of an embodiment of the present invention;

[0014] Figure 2 Exploded schematic diagram of an embodiment of the present invention;

[0015] Figure 3 External shape display diagram of the fully sealed optical engine of an embodiment of the present invention;

[0016] Figure 4 External shape display diagram of the fully sealed optical engine of an embodiment of the present invention from another angle;

[0017] Figure 5 Exploded display diagram of the fully sealed optical engine and the heat dissipation device of an embodiment of the present invention;

[0018] Figure 6 Schematic diagram of the fluid air path of the high-efficiency heat exchanger of the present invention;

[0019] Figure 7 Schematic diagram of a parallel-flow heat exchanger;

[0020] Figure 8 For Figure 7 Analysis schematic diagram;

[0021] Figure 9 It is a schematic diagram of a countercurrent heat exchanger;

[0022] Figure 10 It is Figure 9 an analysis schematic diagram of;

[0023] Figure 11 It is a schematic diagram of an ideal heat exchanger;

[0024] Figure 12 This is the present invention Figure 6 an analysis schematic diagram of. Specific embodiments

[0025] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be described in detail below with reference to the accompanying drawings. The description in this part is only exemplary and explanatory, and should not have any restrictive effect on the protection scope of the present invention.

[0026] It should be noted that: Similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0027] It should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of this invention is usually placed during use. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, the terms "first", "second", "third", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0028] In addition, the terms "horizontal", "vertical", "overhanging", etc. do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0029] In the description of the present invention, it should also be noted that unless otherwise clearly specified and limited, the terms "set", "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0030] Example 1:

[0031] The heat dissipation system of a single LCD projector, especially the heat exchanger of the optical engine, is not just a simple evaluation process of combining scientific principles such as the logarithmic mean temperature difference method (LMTD) and the efficiency - number of transfer units method (ε - NTU), and then calculating and optimizing the heat flow, heat transfer area, fluid pressure, viscosity, etc. by combining fluid mechanics. Instead, considering product positioning, cost - effectiveness, and the degree of adaptation or disruption of the heat dissipation system to the original projector ID (Industrial Design), under the conditions of limited size space and cost, it is necessary to design as scientifically and reasonably as possible and meet the product positioning requirements as much as possible.

[0032] Generally speaking, at the current stage of technology, the heat dissipation of the sealed optical engine of an LCD projector is mainly achieved by setting one or more heat exchangers. Specifically, after forced air cooling of the LCD light valve inside the sealed optical engine, the heat of the hot air accumulated inside the optical engine is transferred to the heat absorption part (located inside the optical engine) of the heat exchanger, and then conducted through a partition (which plays the role of airtightness inside and outside the optical engine) to the heat dissipation part (located outside the optical engine) and diffused into the atmosphere through convection in a certain way. Due to comprehensive factors such as size and cost, the air / air heat exchange method is generally preferred in the industry.

[0033] According to the relative flow direction of the air in the heat absorption / dissipation part, the air / air heat exchanger generally has heat exchange structural forms such as parallel - flow (some industries also call it co - current), counter - flow, and cross - flow. Under the aforementioned limited and equivalent (such as heat flow, heat transfer area, air velocity, flow rate, and temperature difference, etc.) conditions, according to known and well - known knowledge, the heat exchange effect of the parallel - flow type is relatively poor, the heat exchange efficiency of the counter - flow type is relatively high, and the efficiency of the cross - flow type is between the two. The optical engine of the projector must also comply with the setting conditions of the light path, that is, from the projection light source to the projection lens, the heat distribution decreases in turn. Therefore, it is often only convenient to arrange a parallel - flow heat exchanger on the fully sealed optical engine. Representative products include the design of classic products such as Chinese Patent Publication No. CN212540990U, which is also the mainstream technical method of the current sealed optical engine. And for the aforementioned Chinese Patent Publication No. CN113156754A, the heat exchanger of its fully sealed optical engine is of the cross - flow type design. For the new heat exchange method such as the product of Chinese Patent Publication No. CN113448156A mentioned above, it can be understood as a "complex fluid" method, which belongs to a relatively novel and complex technical means. It has unique advantages on compact projectors and products with a relatively small heat dissipation burden on the optical engine because the "return air heat exchange pipe" can just be installed in the triangular area behind the imaging mirror without additional increasing the volume of the optical engine.

[0034] See Figures 1 - 6 As shown, an embodiment of the present invention provides a heat dissipation device for an LCD projector, and the LCD projector has a fully sealed optical engine 10. The heat dissipation device includes an LED light source radiator 11, a high-efficiency heat exchanger 14, an external fan 12, and a wind guide cover 13. Among them, the number of the external fans 12 in this embodiment is preferably but not limited to two, and is preferably but not limited to turbine fans, and two turbine fans are installed in parallel.

[0035] A window for installing the high-efficiency heat exchanger 14 is opened at the bottom of the housing of the fully sealed optical engine 10 (see Figure 5 ). The high-efficiency heat exchanger 14 includes a buckle Fin 1 (Fin refers to fins, rib fins, and "buckle Fin" represents a structural form of fins after stamping, which is an industry term) for absorbing heat on the relatively high-temperature side, i.e., inside the optical engine, a partition 2, and a sunflower profile 3 for spreading heat (or releasing heat) on the relatively low-temperature side, i.e., outside the optical engine. In this embodiment, the number of the sunflower profiles 3 is preferably but not limited to two, and the two sunflower profiles are arranged in parallel, and each is opposite to one of the external fans 12. The surface profile of the ribs of the sunflower profile 3 is preferably an involute spiral shape, and at the same time, the involute spiral direction of the rib surface is preferably opposite to the rotation direction of the external fan 12. All of the above means are very beneficial to reducing the suction resistance of the external fan 12 and increasing the heat transfer area per unit volume of the sunflower profile 3 (i.e., m 2 / m 3 ), and are also very beneficial to improving the flow loss of the air in the boundary layer of the rib surface. After actual measurement, compared with the air resistance (wind pressure, air volume, flow rate, etc.) of the external fan 12 in this embodiment when installed and operating in a completely open environment state, it is only about 10% lower than the latter, and it has excellent air resistance and noise indicators. The specific parameters of the involute spiral are omitted.

[0036] The buckle Fin 1, the partition 2, and the sunflower profile 3 are sequentially attached to each other, specifically, the three are welded and fixed into one body by high-frequency soldering. The three are preferably but not limited to aluminum or aluminum alloy materials (nickel plating is required), have high thermal conductivity and cost performance, and the weight is not too large. The buckle Fin 1 is located on the internal heat dissipation air duct of the fully sealed optical engine 10 and is opposite to the air outlets of the two turbine fans 103 arranged inside the fully sealed optical engine 10 (see Figure 5) The partition plate 2 seals the window opened at the bottom of the housing of the fully sealed optical machine 10 for installing the high-efficiency heat exchanger 14. The air inlets of the two external fans 12 are opposite to the two sunflower profiles 3 one by one. In this embodiment, a gap of about 9 mm - 10 mm is left between the external fan 12 and the sunflower profile 3 to facilitate the design of the first air duct 131 and reduce noise. The air outlet of the external fan 12 is opposite to the LED light source radiator 11.

[0037] The air guide cover 13 seals the gap between the external fan 12 and the sunflower profile 3 and correspondingly encloses a horn-shaped first air duct 131. See Figure 2 As shown, there are two horn-shaped air ducts, corresponding to the external fan 12 and the sunflower profile 3 one by one. Because the intentionally selected envelope outer diameter of the rib end of the sunflower profile 3 is larger than the diameter of the air inlet of the external fan 12, and the horn-shaped air duct (funnel-shaped) is conducive to forming an air duct with excellent performance and sealing the air duct. Because the funnel shape is designed according to the fluid flow direction and the pipe cross-section from large to small, it can more easily avoid fluid separation.

[0038] One end of the funnel, i.e., the larger-diameter end of the horn-shaped air duct, is sleeved into the sunflower profile 3 by at least about 1 - 2 mm (the thickness of the sunflower profile 3 in this embodiment is about 18 mm - 22 mm). The relatively smaller-diameter end of the funnel is opposite to and in contact with the air inlet of the external fan 12, and the diameter of the cross-section of the funnel end through which the fluid flows is equal to or slightly larger than the diameter of the air inlet of the external fan 12, which depends on the design matching of the best air resistance between the funnel and the fan. At the same time, the air guide cover 13 also seals the space between the air outlet of the external fan 12 and the LED light source radiator 11 and encloses to form a second air duct 132 (see Figure 5 As shown), preventing air short-circuit and ineffective pressure diffusion. Finally, the hot air flowing out of the LED light source radiator 11 is discharged into the atmosphere through the ventilation holes on the projector housing (not shown in the figure). In this way, the external fan 12 not only cools the high-efficiency heat exchanger 14 but also dissipates the heat of the projector LED light source, achieving multiple benefits. It is beneficial to reduce the cost of the projector, reduce the volume, reduce the noise, and leanly control the cost performance of the product from the R & D end, so that the product design can meet the positioning requirements as much as possible.

[0039] In this embodiment, the LED light source radiator 11 is preferably but not limited to a heat pipe radiator. The LED light source radiator 11 includes a heat absorption substrate (for installing the LED light source 15), heat pipes 112, and fins 111. These are all common knowledge of the heat pipe radiator structure and will not be elaborated here.

[0040] The fully sealed optical engine 10 of this embodiment can select the optical principle technology of the aforementioned publication number CN113156754A, and after adding the return air heat exchange technology of the aforementioned publication number CN113448156A, it is then optimized and designed and manufactured. In Figures 3 - 5 101 is a projection lens, 102 is an FPC cable of the LCD light valve, 103 is an internal fan of the fully sealed optical engine 10 (the number is two in the figure), 104 is a return air heat exchange pipe, and a wind guiding gyro is installed inside the return air heat exchange pipe 104, 105 is a drainage volute (the return air heat exchange pipe 104, the wind guiding gyro, the drainage volute 105, etc. can be referred to the Chinese patent publication number CN113448156A), 106 is a lighting reflector. The specific heat dissipation working principle and product structure of the cited technology can be referred to the above-mentioned patent literature. Based on the heat dissipation system of the above-mentioned patent literature in the embodiment of the present invention, the temperature of the LCD light valve is significantly lower than that of the technology of the above-mentioned cited literature, the LED light source radiator 11 can install a higher-power LED light source, and the product noise is lower, thereby allowing the projector to output higher brightness and obtain better durability, achieving positive effects.

[0041] To further illustrate the innovation and advancement of the present invention, please continue to refer to Figures 7 - 11 as shown: Figure 7 is a structural schematic diagram of a parallel flow heat exchanger. In the figure, sur (surface) is a partition of the heat exchanger, i is the fluid on the relatively high-temperature side of the heat exchanger (corresponding to the fluid inside the optical engine in the present invention), i' is the fluid on the relatively low-temperature side (outside the optical engine), Fin-A is the heat absorption part of the heat exchanger, such as the structure is Fin, Fin-B is the Fin of the heat dissipation part of the heat exchanger, TH-in is the temperature of i flowing into Fin-A, TH-out is the temperature of i flowing out of Fin-A, TL-in is the temperature of i' flowing into Fin-B, and TL-out is the temperature of i' flowing out of Fin-B.

[0042] From Figure 7 it can be seen that Fin-A, sur, and Fin-B are sequentially arranged in contact with each other to form a heat exchanger (module), and the directions of fluids i and i' are the same. Figure 8 is Figure 7 a schematic diagram of parameter analysis of the heat exchange system. Figure 8 In it, L can be understood as the equivalent length of the heat exchanger module composed of Fin-A, sur, and Fin-B. The coordinate origin is correspondingly regarded as the inflow part of i and i', and the abscissa L is correspondingly regarded as the outflow part of i and i'.

[0043] Refer to Figure 7, Fluid i (hot air) transfers (or exchanges) heat to Fin-A through forced convection, and then Fin-A conducts the heat to sur, and then sur conducts the heat to Fin-B. Through external forced convection, after fluid i' (cold air) absorbs the heat of Fin-B, it diffuses the heat into the atmosphere. Take an infinitesimal segment (or infinitesimal surface) dx within 0-L. According to the heat transfer equation and the heat balance equation, after substituting and differentiating the equations (combining with the aforementioned LMTD method), it can be known that the heat transfer capacity (or heat transfer driving force) at dx is proportional to the reciprocal of the natural logarithm difference between the inlet and outlet fluid temperature differences at dx, and the logarithm difference is equal to the logarithm of the quotient of the true numbers. See Figure 8 , as i and i' flow in the X direction, the temperature difference between TH-out and TL-out becomes smaller and smaller and finally tends to be basically completely equal. When representing the division of the true numbers of dx, the denominator is zero, so the algorithm is meaningless, and further represents that heat exchange at the infinitesimal surface dx of the heat exchanger is meaningless (or fails). Furthermore, it can be known that even if the value of the above L (length) is further increased, the heat transfer effect of the infinitesimal surface dx at the corresponding position approaches zero, that is, the heat exchange function is lost.

[0044] nL is an optimized length value that will be selected or discarded when designing a specific product, representing the specific data selection of the equivalent length L of the heat exchanger. Usually determined by product positioning, mainly factors such as cost, volume, and weight. Often sacrificing in terms of length may gain benefits in terms of cost, and thus achieve a certain rationality and design balance. nL should preferably be selected at the part where the increment of the temperature logarithm change curve of i and i' is more obvious, rather than at the part approaching saturation (i.e., no increment).

[0045] See Figure 9 As shown in the schematic diagram of a countercurrent heat exchanger, it is not difficult to see that the flow directions of i and i' are opposite. Figure 10 is Figure 9 the schematic diagram of parameter analysis. Relatively speaking, the temperature differences between TH-out and TL-in, and TH-in and TL-out always exist and remain at relatively large values. Therefore, the illustrated countercurrent heat exchanger has relatively high heat exchange efficiency. As mentioned above, from the projection light source to the projection lens, the heat distribution decreases successively. Therefore, it is relatively difficult to arrange this kind of heat exchanger inside an actual projector to dissipate (exchange) heat for the fully sealed optical engine.

[0046] The above Figure 7 and Figure 9 The two heat exchangers shown above both have theoretical and engineering limitations. For the heat dissipation of the sealed optical engine of a projector, undoubtedly, Figure 11The ideal heat exchanger shown is the best technical choice. However, such an ideal heat exchanger is extremely difficult to exist in practice, unless additional energy (such as a cold pump) is used to keep i' at a constant low temperature to achieve the most efficient cooling of i. However, technical methods such as increasing costs, increasing the complexity of the system, and increasing the manufacturing difficulty are all contrary to the development direction of the product and the industry.

[0047] As described above, by keeping the air flow i' on the low-temperature side of the heat exchanger at a constant low temperature, higher heat transfer efficiency can be obtained. That is to say, on any micro-element surface within 0-L, the temperature of the air flow i' on the low-temperature side of the heat exchanger remains unchanged, which can significantly improve the total heat transfer coefficient of each micro-element surface, and thus cool the air flow i on the high-temperature side more rapidly. See Figure 6 As shown, the high-efficiency heat exchanger 14 of the present invention is composed of a buckle Fin 1, a partition plate 2, and a sunflower profile 3 sequentially adhered to each other. Figure 6 Among them, facing the human face are the buckle Fin 1 (solid line), the partition plate 2 (solid line), and the sunflower profile 3 (the part blocked by the partition plate 2 is a dotted line) in sequence. After the relatively hot air flow i after forced air cooling of the LCD light valve inside the fully sealed optical engine 10 flows through the buckle Fin 1, it transfers heat to the buckle Fin 1, and then through the partition plate 2, conducts the heat to the sunflower profile 3. See Figure 12 As shown, O is the equivalent center of the high-efficiency heat exchanger 14 of the present invention, and L / 2 and -L / 2 are the equivalent heat exchanger lengths symmetric about the equivalent center point. For any micro-element surface (section) of the high-efficiency heat exchanger 14 along the heat-cold heat transfer direction, for example, taking the curved surface where the rib surface of the sunflower profile 3 is located as the micro-element surface, obviously, the TL-in of any micro-element surface is normal temperature and equal, that is, the air flows i1', i2', i3', i4', i5', i6', i7', ……, in' on the heat release side, etc., and their TL-in all have the largest temperature difference with the TH-in of the air flow i inside the optical engine. Furthermore, an almost Figure 11 shown ideal heat exchanger cooling and heat transfer effect. Figure 12 Among them, under the same conditions (such as heat transfer area, power, flow rate, etc.), the TH-out' of the present invention must be much lower than the TH-out value of general heat exchangers such as the aforementioned parallel flow, counter flow, and cross flow. Because the temperature difference between the inlet and outlet fluids at any micro-element surface dx has the possibility of being in the relatively steep section of the logarithmic curve change amount in theory, the temperature difference is the largest, which also means being in the working state with the highest heat transfer driving force. Here, nL can be understood as the equivalent center O of the high-efficiency heat exchanger 14 of the present invention.

[0048] The basic principles, main features and advantages of the present invention have been shown and described above. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principles of the present invention. Without departing from the spirit and scope of the present invention, various changes and improvements will occur to the present invention, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A heat dissipation device for an LCD projector, the LCD projector having a fully sealed optical engine (10); characterized in that, The heat dissipation device comprises an LED light source heat sink (11), a high-efficiency heat exchanger (14), an external fan (12) and an air guide cover (13); a window for installing the high-efficiency heat exchanger (14) is provided at the bottom of the shell of the fully sealed light engine (10); the high-efficiency heat exchanger (14) comprises a buckle fin (1) on the high-temperature heat absorption side, a partition (2) and a sunflower profile (3) on the low-temperature heat release side, and the buckle fin (1), the partition (2) and the sunflower profile (3) are arranged in sequence; the buckle fin (1) is located on the internal heat dissipation air duct of the fully sealed light engine (10), and the partition (2) is provided on the bottom of the shell of the fully sealed light engine (10) for cooling the air. The window on which the high-efficiency heat exchanger (14) is installed is sealed; the air inlet of the external fan (12) is opposite to the sunflower profile (3), and a gap is left between the external fan (12) and the sunflower profile (3); the air outlet of the external fan (12) is opposite to the LED light source heat sink (11); the air guide cover (13) seals the gap between the air inlet of the external fan (12) and the sunflower profile (3) and encloses a first air duct (131); the air guide cover (13) seals the gap between the air outlet of the external fan (12) and the LED light source heat sink (11) and encloses a second air duct (132).

2. The heat dissipation device of an LCD projector according to claim 1, characterized in that, The external fan (12) is a turbine fan.

3. The heat dissipation device of an LCD projector according to claim 1, wherein, The rib surface of the sunflower profile (3) is in the shape of an involute spiral.

4. The heat dissipation device of an LCD projector according to claim 1, characterized in that, The involute spiral direction of the rib surface of the sunflower profile (3) is opposite to the rotation direction of the external fan (12).

5. The heat dissipation device of an LCD projector according to claim 1, characterized in that, The number of the sunflower profiles (3) is equal to the number of the external fans (12).

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