A dual-fan heat dissipation device for the LCD light valve of a projector

Abstract

The present invention discloses a double-fan heat dissipation device for a projector LCD light valve, which includes a first fan and a second fan arranged in parallel; the first fan and the second fan are turbine fans; a first air duct is formed between the front Fresnel lens and the LCD light valve and the side wall of the optical engine housing; a second air duct is formed between the LCD light valve and the rear Fresnel lens and the side wall of the optical engine housing; the air outlets of the first fan and the second fan blow air towards the first air duct and the second air duct; the rotation directions of the first fan and the second fan are opposite. The present invention can effectively reduce the dead zone of the heat exchange surface of the LCD light valve during the parallel heat dissipation of the double fans, and can effectively improve the losses and adverse effects such as acoustic resonance, vortex, turbulence and fluid stratification during the parallel heat dissipation of the double fans, reduce the fan noise and significantly improve the heat dissipation efficiency, and keep the volume of the heat dissipation device as small as possible.

Description

Technical Field

[0001] The present invention relates to the technical field of projectors, and particularly to a double - fan heat dissipation device for an LCD light valve of a projector. Background Art

[0002] The heat dissipation of the transmissive light valve of an LCD projector has always been one of the common technical problems in the industry. It can be said without exaggeration that even a 1% improvement in heat dissipation performance is regarded as a very valuable technological progress.

[0003] This is determined by the characteristics of the transmissive LCD light valve. The light valve with a main body of molten glass material has extremely poor heat conduction and heat diffusion performance. When light is transmitted, most of the light is absorbed by the light valve and converted into Joule heat. Moreover, the heat dissipation function and the light transmission function of the light valve overlap. Additionally, the optical devices in front of and behind the light valve, such as the front Fresnel lens and the rear Fresnel lens (the "Fresnel lens" is the abbreviation of the Fresnel lens in the industry), also severely limit the design of an efficient heat dissipation air duct for the light valve. Considering various engineering constraints, the heat dissipation of the light valve is mainly achieved by directly blowing air on the surface of the light valve through forced air cooling.

[0004] Therefore, generally, the larger the size of the fan blowing air on the LCD light valve (such as a 120*120*35mm turbo - fan), the better the air volume, air pressure and other indicators, and the better the heat dissipation effect. However, these large - size fans usually significantly increase the external dimensions of the LCD projector to an unreasonable extent. People generally do not choose this extreme method, but tend to choose two smaller - size fans (such as 50*50*20mm turbo - fans) arranged in parallel to blow air on the LCD light valve (the above two 5020 - sized fans have good size matching for the current 3.5 - inch - 5.2 - inch LCD light valves in the industry). This can control the external dimensions of the projector as much as possible and can also directly reduce costs to a certain extent (the unit price of small fans is much lower) and improve the cost - performance ratio. As Figure 6 shown is a typical structure of some existing products in the industry that apply double - fans. Other representative double - fan structures also include the technologies shown in Chinese Patent Publication Nos. CN212905875U, CN215420558U, etc.

[0005] However, the use of double - fans is a very complex and delicate practical engineering technology. Besides being able to better control the external dimensions of the whole machine, its losses and adverse effects such as acoustic resonance, vortex, turbulence and stratification may not necessarily play a perfect role in heat dissipation. And compared with Figure 7 the single - fan heat dissipation shown, the aerodynamic complexity of the double - fan technology has an essential difference. Therefore, how to maximize the performance of double - fans and effectively overcome the disadvantages has become an urgent problem for those skilled in the art. Summary of the Invention

[0006] The object of the present invention is to overcome the deficiencies of the prior art and provide a double-fan heat dissipation device for a projector LCD light valve. The present invention can effectively reduce the dead zone of the heat exchange surface of the LCD light valve during the parallel heat dissipation of the double fans, and can effectively improve the losses and adverse effects such as acoustic resonance, vortex, turbulence, and fluid stratification during the parallel heat dissipation of the double fans, reduce the fan noise, significantly improve the heat dissipation efficiency, and keep the volume of the air-cooling device as small as possible.

[0007] To achieve the above object, the present invention provides a double-fan heat dissipation device for a projector LCD light valve. The projector has a front Fresnel lens, an LCD light valve, a rear Fresnel lens, and an optical engine housing. The front Fresnel lens, the LCD light valve, and the rear Fresnel lens are located in the optical engine housing, and the front Fresnel lens, the LCD light valve, and the rear Fresnel lens are arranged in sequence according to the light traveling direction. The double-fan heat dissipation device includes a first fan and a second fan arranged in parallel. The first fan and the second fan are turbine fans.

[0008] A first air duct is formed between the front Fresnel lens and the LCD light valve and the side wall of the optical engine housing. A second air duct is formed between the LCD light valve and the rear Fresnel lens and the side wall of the optical engine housing. The air outlets of the first fan and the second fan blow air towards the first air duct and the second air duct.

[0009] The plane in the radial direction of the impellers of the first fan and the second fan is parallel to the light passing surface of the LCD light valve; or the plane in the radial direction of the impellers of the first fan and the second fan intersects the light passing surface of the LCD light valve, and the intersection line is parallel to the horizontal bisector of the light passing surface of the LCD light valve.

[0010] The rotation directions of the first fan and the second fan are opposite. Looking at the exit surface of the LCD light valve, the first fan is located on the left side of the vertical bisector of the light passing surface of the LCD light valve, and the first fan rotates clockwise. The second fan is located on the right side of the vertical bisector of the light passing surface of the LCD light valve, and the second fan rotates counterclockwise.

[0011] Preferably, the rotational speeds of the first fan and the second fan are not equal.

[0012] The beneficial effects of the present invention are as follows:

[0013] In the present invention, the first fan and the second fan are arranged in parallel. The air outlets of the first fan and the second fan blow air towards the first air duct and the second air duct respectively, so as to achieve effective and rapid heat dissipation for the LCD light valve. At the same time, the rotation directions of the first fan and the second fan are opposite. When looking at the exit surface of the LCD light valve, the first fan is located on the left side of the vertical bisector of the light-passing surface of the LCD light valve and rotates clockwise, while the second fan is located on the right side of the vertical bisector of the light-passing surface of the LCD light valve and rotates counterclockwise. In this way, it can effectively reduce the dead zone of the heat exchange surface of the LCD light valve when two fans are arranged in parallel for heat dissipation, and can effectively improve the losses and adverse effects such as acoustic resonance, vortex, turbulence and fluid stratification in the heat dissipation of two fans arranged in parallel, reduce the fan noise and significantly improve the heat dissipation efficiency, and keep the volume of the heat dissipation device as small as possible. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] 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 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, without creative efforts, other drawings can be obtained based on these drawings.

[0015] Figure 1 Schematic diagram of an embodiment of the present invention;

[0016] Figure 2 Stereogram of an embodiment of the present invention;

[0017] Figure 3 Schematic diagram of the heat dissipation air duct of the LCD light valve of the present invention;

[0018] Figure 4 Schematic diagram of a variation of an embodiment of the present invention;

[0019] Figure 5 Schematic diagram of the air flow of two fans in a free state;

[0020] Figure 6 Display diagram of the existing two-fan heat dissipation technology after installation;

[0021] Figure 7 Schematic diagram of the heat dissipation of the existing single fan;

[0022] Figure 8 Schematic diagram of the heat dissipation of a two-fan. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be described in detail below with reference to the drawings. The description in this part is only exemplary and explanatory, and should not have any limiting effect on the protection scope of the present invention.

[0024] It should be noted that like reference numerals and letters denote like items in the following figures, and thus, once an item is defined in one figure, it is not necessary to further define and explain it in subsequent figures.

[0025] 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 figures, or the orientation or positional relationship in which the inventive product is customarily 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 thus cannot be construed as a limitation of the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive distinction and cannot be construed as indicating or implying relative importance.

[0026] In addition, terms such as "horizontal", "vertical", "hanging" do not mean that the components are required to be absolutely horizontal or hanging, 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.

[0027] In the description of the present invention, it should also be noted that unless otherwise clearly specified and limited, the terms "arranged", "installed", "connected", "coupled" 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 circumstances. Specific embodiments:

[0029] See Figures 1-3 As shown, a double-fan heat dissipation device for a projector LCD light valve provided in this embodiment. The projector has a front Fresnel lens 2, an LCD light valve 1, a rear Fresnel lens 3, and an optical machine housing 6. The front Fresnel lens 2, the LCD light valve 1, and the rear Fresnel lens 3 are located inside the optical machine housing 6, and the front Fresnel lens 2, the LCD light valve 1, and the rear Fresnel lens 3 are arranged in sequence according to the light traveling direction. The optical machine housing 6 is mainly used to fix the optical devices and necessary raw materials such as the radiator of the LCD projector. The optical materials also include a projection light source, a condensing device, a projection lens, etc., which are all standard configurations of domestic LCD projectors and are not shown in the figure and will not be elaborated.

[0030] The double-fan heat dissipation device includes a first fan 4 and a second fan 5 arranged in parallel; the first fan 4 and the second fan 5 are turbine fans.

[0031] A first air duct is formed between the front Fresnel lens 2 and the LCD light valve 1 and the side wall of the optical engine housing 6; a second air duct is formed between the LCD light valve 1 and the rear Fresnel lens 3 and the side wall of the optical engine housing 6; the air outlets of the first fan 4 and the second fan 5 face the first air duct and the second air duct to blow air, as shown in Figure 2 and 3 shown. The air flow flows in from one end of the first air duct and the second air duct and flows out from the other end, so as to effectively and quickly dissipate heat from the LCD light valve 1 under the action of the first fan 4 and the second fan 5.

[0032] The plane in the radial direction of the impellers of the first fan 4 and the second fan 5 (which can also be understood as the plane where the air inlets of the first fan 4 and the second fan 5 are located) is parallel to the light passing surface of the LCD light valve 1 (see Figure 1 、 Figure 2 and Figure 4 ); or the plane in the radial direction of the impellers of the first fan 4 and the second fan 5 intersects with the light passing surface of the LCD light valve 1 (or the light transmission window, the same below), and the intersection line is parallel to the horizontal bisector of the light passing surface of the LCD light valve 1 (not shown in the figure). Figure 1 In , y is the vertical bisector of the light transmission window of the LCD light valve 1, and the "horizontal bisector" is the bisector orthogonal to the vertical bisector y within the light transmission window of the LCD light valve 1, which is not drawn in the figure.

[0033] Continue to refer to Figure 1 shown. The rotation directions of the first fan 4 and the second fan 5 are opposite. Looking at the exit surface of the LCD light valve 1, the first fan 4 is located on the left side of the vertical bisector y of the light passing surface of the LCD light valve 1, and the first fan 4 rotates clockwise (see Figure 1 the rotation arrow directions on the first fan 4 and the second fan 5 in , the same below), the second fan 5 is located on the right side of the vertical bisector y of the light passing surface of the LCD light valve 1, and the second fan 5 rotates counterclockwise. Since the impeller sizes of the first fan 4 and the second fan 5 are the same, even if there are slight differences in rotational speed and air pressure, the mutual aerodynamic influence between the first fan 4 and the second fan 5 is actually very low. In addition to generating vortices in the A3 area in this embodiment, considering the case where the air outlet sizes of the first fan 4 and the second fan 5 and the long side dimension of the light transmission window of the LCD light valve 1 are well matched as shown in the figure, the areas of the heat dissipation dead zones A1 and A2 are very small. Because the illumination uniformity of a single LCD projector is often not high, even if there is no air flow passing over the heat dissipation dead zones A1 and A2 at the edge of the light transmission window of the LCD light valve 1, it usually has no impact on the safety of the LCD light valve 1. For the area with significantly reduced illumination uniformity, see Figure 6The area shown to the right of the dashed line D'.

[0034] In this embodiment, the rotational speeds of the first fan 4 and the second fan 5 need to be set to be unequal on most actual projectors in order to minimize noise. Because for a specific air duct, to eliminate the airflow resonance between the first fan 4 and the second fan 5, the rotational speeds of the first fan 4 and the second fan 5 are often set to be unequal, which has the simplest and most direct effect.

[0035] To facilitate the demonstration of the superiority of the technology of the present invention, refer to Figures 5-7 the prior art or the basic principle technology for further analysis and explanation. Among them, Figure 5 is a schematic diagram of the air flow of a free-state, simple dual-fan air outlet. When the first fan 4' and the second fan 5' are arranged in parallel and rotate in the same direction, and are freely located in the air, the mutual aerodynamic influence is negligible. That is, the velocity field of the air flow from the air outlets of the first fan 4' and the second fan 5' flows out in a centrifugal and diffusive path in accordance with the basic law, and has regularity. The air flow mainly includes two-directional forces, one is the force blowing forward (the tangential force perpendicular to the air outlet of the fan), and the other is the axial force rotating around the fan shaft.

[0036] In fact, once the fans are installed in the projector optical engine, both the first fan 4' and the second fan 5' work in a space with limited edge dimensions or in an air duct with specific physical indicators, and the characteristics of the air flow will change fundamentally, and its specific manifestation of the air flow is often as Figure 6 shown.

[0037] Figure 6 is a schematic diagram of a representative prior art dual-fan heat dissipation technology. The first fan 4' and the second fan 5' are arranged in parallel to blow air to the LCD light valve 1' (for the corresponding air duct, refer to Figure 2 , Figure 3, usually such structures), the shaded area A1' can hardly be effectively cooled by the air flow (cooling dead zone), that is, basically no air flow passes over the surface of the LCD light valve 1' corresponding to the shaded area A1'. The air flow trajectory lines (also known as "air flow movement trace lines", etc.) with an infinite number flowing out of the second fan 5' are abstractly represented and indicated by lines such as F51', F52', etc.; the air flow trajectory lines flowing out of the first fan 4' are abstractly represented and indicated by lines such as F41', F42', and F43'. Among the air flows discharged from the first fan 4' and the second fan 5', the air flow F51' and the air flow F43' are adjacent. Since the flow velocity of the air flow F43' is significantly higher than that of the air flow F51', the pressure in the low-pressure area generated by the air flow F43' around it is lower. At the same time, under the further action of the axial force component of the air flow F51' itself, the direction of the air flow F51' will be forcibly pulled towards the flow track of the air flow F43'. As a result, the overall air flow discharged from the second fan 5' is pulled towards the fluid track of the air flow discharged from the first fan 4'. This is the reason why basically no air flow passes over the above-mentioned area A1'. At the same time, a vortex area A2' is generated between the air flow F43' and the air flow F51', which further increases the resistance of the air flow F51'. These factors are all the reasons for pulling the overall air flow discharged from the second fan 5' towards the air flow beam (or fluid) track of the first fan 4'.

[0038] Since today's LCD light valves have entered the era of aspect ratios such as 16:9 and 16:10, Figure 6 the area of the cooling dead zone A1' in it almost accounts for more than half of the light-transmitting window of the LCD light valve 1', which is extremely unfavorable for the heat dissipation of the LCD light valve 1'. It is often manifested in serious color deviation of the image, poor durability, and seriously affecting the user's viewing experience.

[0039] Furthermore, when the air flows F41', F42', F43', etc. travel in the first air duct and the second air duct (not shown in the figure), they will also hit the side wall in the vertical direction of the optical engine housing 6', and then form several vortices A3', A4', etc. in the area close to the side wall in the vertical direction of the optical engine housing 6'. These vortices will all increase the air resistance and generate noise. These factors are very unfavorable for Figure 6 the existing double-fan cooling technology shown. Figure 7 is a schematic diagram of the ordinary single-fan cooling of the LCD light valve 1'. This method has no mutual aerodynamic interference between the double fans. However, when the size of the LCD light valve 1' is large (such as 4 - 7 inches), not only a very large-sized fan is required, but also the volume of the projector will be significantly increased (including the increased volume of the fan and the volume of the air duct length), which is impractical; if the size of the fan is small, then as Figure 7 shown, the cooling dead zones A9' and A10' objectively exist, which is very unfavorable for the stability and durability of the LCD light valve 1'.

[0040] Figure 4 As a variant design of this embodiment, when the total width dimension of the parallel arrangement of the first fan 4 and the second fan 5 is slightly larger than the dimension of a certain side (such as the long side) of the light-transmitting window of the LCD light valve 1, the placement of the first fan 4 and the second fan 5 can be appropriately rotated so that the air outlets of the first fan 4 and the second fan 5 match the first air duct and the second air duct, which is beneficial to reducing the vortex between the first fan 4 and the second fan 5 and reducing the areas of the heat dissipation dead zones A1 and A2.

[0041] Under the same design conditions of the projector (such as the same size of the fan and the LCD light valve, and the same size of the first air duct and the second air duct, etc.), in this embodiment, both the side effects of the heat dissipation dead zones A1 and A2 and the vortex region A3 are significantly improved compared with Figure 6 the widely used existing technology shown.

[0042] See Figure 1 as shown and the conditions such as the opposite rotation directions of the first fan 4 and the second fan 5 as described above. The significant feature is that when looking directly at the light-emitting surface of the LCD light valve 1, the first fan 4 is located on the left side of the vertical bisector y of the light-transmitting surface of the LCD light valve 1 and rotates clockwise; the second fan 5 is located on the right side of the vertical bisector y of the light-transmitting surface of the LCD light valve 1 and rotates counterclockwise. And as Figure 8 shown, the rotation directions of the first fan 4' and the second fan 5' are opposite. When looking directly at the light-emitting surface of the LCD light valve 1', the first fan 4' is located on the left side of the vertical bisector y' of the light-transmitting surface of the LCD light valve 1' and rotates counterclockwise; the second fan 5' is located on the right side of the vertical bisector y' of the light-transmitting surface of the LCD light valve 1' and rotates clockwise. Obviously, if Figure 1 and Figure 8 are under the same conditions, then Figure 8 the heat dissipation dead zones A5' and A6' of Figure 1 are much larger than the heat dissipation dead zones A1 and A2 of

[0043] The above shows and describes the basic principles, main features and advantages of the present invention. 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, the present invention will have various changes and improvements, 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 double-fan heat dissipation device for a projector LCD light valve. The projector has a front Fresnel lens (2), an LCD light valve (1), a rear Fresnel lens (3), and an optical engine housing (6). The front Fresnel lens (2), the LCD light valve (1), and the rear Fresnel lens (3) are located inside the optical engine housing (6), and the front Fresnel lens (2), the LCD light valve (1), and the rear Fresnel lens (3) are arranged in sequence along the light traveling direction. It is characterized in that, The double-fan heat dissipation device includes a first fan (4) and a second fan (5) arranged in parallel; the first fan (4) and the second fan (5) are turbine fans; A first air duct is formed between the front Fresnel lens (2) and the LCD light valve (1) and the side wall of the optical engine housing (6); a second air duct is formed between the LCD light valve (1) and the rear Fresnel lens (3) and the side wall of the optical engine housing (6); the air outlets of the first fan (4) and the second fan (5) blow air towards the first air duct and the second air duct; The plane in the radial direction of the impellers of the first fan (4) and the second fan (5) is parallel to the light passing surface of the LCD light valve (1); or the plane in the radial direction of the impellers of the first fan (4) and the second fan (5) intersects with the light passing surface of the LCD light valve (1), and the intersection line is parallel to the horizontal bisector of the light passing surface of the LCD light valve (1); The rotation directions of the first fan (4) and the second fan (5) are opposite. Looking at the exit surface of the LCD light valve (1), the first fan (4) is located on the left side of the vertical bisector of the light passing surface of the LCD light valve (1), and the first fan (4) rotates clockwise; the second fan (5) is located on the right side of the vertical bisector of the light passing surface of the LCD light valve (1), and the second fan (5) rotates counterclockwise; The rotational speeds of the first fan (4) and the second fan (5) are not equal.

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