JPH11112176A - Cooling mechanism using axial flow fan and electronic device having the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attempt to maintain an sufficient cooling efficiency by an wind inducing plate to orient an air flow which is blown out by a fin wheel before sending from an axial flow fan, even in case a spacing between the axial flow fan and parts to be cooled is narrow. SOLUTION: When a fin wheel 33 of an axial flow fan 3 is driven to rotate, an air flow toward the axis and the peripheral directions is generated. This flow is orientated toward the axis direction by reflecting from a wind inducing part 51 of a wind inducing plate 5. Therefore, the air flow which is induced from the axial flow fan 3 to the wind inducing part 51 and is also sent out via a blowing aperture 60 is large in the axial direction and little in the peripheral direction, and is efficiently sent toward a crystal panel 22 and a deflection plate 22 because the volume to be spread the outside of the radial direction by the centrifugal force becomes less. Even if an interval between the axial flow fan 3 and the crystal panel 20 and the deflection panel 22 is narrow, the crystal panel 20 and the deflection plate 22 can sufficiently be cooled. Parts to be cooled which are provided at the axial direction of windward of the axial flow type flow transfer fan 3 are applied to another electronic device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mechanism for cooling components having low heat resistance, such as a liquid crystal panel and a polarizing plate, using an axial fan in electronic equipment such as a liquid crystal projector.

[0002]

2. Description of the Related Art A cooling mechanism in an electronic device will be described below by taking a liquid crystal projector as an example. FIG. 2 is a side view showing the liquid crystal projector (1). LCD projector
(1) As is well known, a light beam projected from a light source (11) such as a halogen lamp or a metal halide lamp passes through a liquid crystal panel (20) and is expanded through a projection lens (12). Thus, the image displayed by the liquid crystal panel (20) is enlarged and displayed on the screen. In general, LCD panel (20)
Is weak to heat, and the contrast decreases as the temperature rises. Therefore, air is blown to the liquid crystal panel (20) by the axial fan (3) to cool the air.

[0003] A liquid crystal projector (1) shown in FIG. 3 is a color liquid crystal projector, and includes R (red), G (green),
Liquid crystal panels (2
0) (20a) (20b) are deployed, and each liquid crystal panel (20) (20a) (20b)
Dichroic prism (70)
This is a prism method that is performed. As shown, the optical systems such as the liquid crystal panels (20), (20a) and (20b) and the dichroic prism (70) are provided in a chassis (6) for guiding the light beam of the light source (11) to the projection lens (12). Is done. This type of liquid crystal projector
In (1), the liquid crystal panels (20), (20a) and (20b) are gathered and arranged around the dichroic prism (70).
In (6), blow openings (60), (60a), (60b) are opened at positions facing the liquid crystal panels (20), (20a), (20b), and as shown in FIG. Axial fan just below (60a) (60b)
By disposing (3), the flow (wind) of the air blown out from the axial fan (3) is changed to the blowing openings (60) (60a) (60b).
, And directly hit the liquid crystal panels (20), (20a), (20b) to be cooled.

The air blown from the axial fan (3) is
It has an axial and a circumferential velocity component, and an outward centrifugal force is exerted by the circumferential velocity component. Accordingly, when the blow openings (60), (60a), (60b) are provided immediately above the axial fan (3), the air blown out from the blow openings (60), (60a), (60b) is subjected to the centrifugal force. , And does not sufficiently hit the liquid crystal panels (20), (20a) and (20b), and as a result, the liquid crystal panels (20) (20a) (20
Insufficient cooling in b). Therefore, the axial fan (3) and the blow openings (60), (60a), (60b) are arranged to be separated from each other to some extent (at least the height of the impeller (33)), and the axial fan (3) and the blower are blown. A peripheral wall (45) is provided between the openings (60), (60a), and (60b) to restrict air flowing outward. As the air rises in the peripheral wall (45), it flows around the peripheral wall (45) due to centrifugal force,
A radial pressure gradient occurs. Therefore, when air rises to some extent in the peripheral wall (45), the centripetal force due to the pressure gradient,
The centrifugal force is balanced. After that, blow opening (60) (60
a) The air blown into the chassis (8) through (60b) does not flow outward due to the above-mentioned balance, and the liquid crystal panels (20) (2)
0a) It can be cooled by directly hitting (20b).

In order to increase the flow rate of air blown from the blow openings (60), (60a), (60b), the blow openings (60), (6)
A wind guide plate (9) is provided at 0a and (60b). By the air guide plate (9), the flow rate of air hitting the liquid crystal panels (20), (20a), (20b) is increased, and the cooling effect of the liquid crystal panels (20), (20a), (20b) can be enhanced.

[0006]

Recently, with the demand for downsizing of electronic equipment, it has been required to reduce the distance between the axial fan (3) and a component to be cooled such as the liquid crystal panel (20). ing. However, if the interval is small, the air blown out from the axial fan (3) flows outward as described above,
Insufficient cooling of the component to be cooled.

[0007]

As shown in FIG. 5, the axial fan (3) comprises:
A motor (32) is provided above a frame (30) via a support rod (31), and an impeller (33) is provided below the motor (32). The impeller (33) blows out the wind. The present inventor has proposed an axial fan
Focusing on the above structure of (3), the following solution was devised. An object of the present invention is to provide a cooling mechanism that can sufficiently cool an axial flow fan (3) and a component to be cooled such as a liquid crystal panel (20) even if the space between the component and the component is reduced.

[0008]

According to the cooling mechanism of the present invention, the upstream edge of the air guide plate for guiding the air sent from the axial fan toward the component to be cooled is formed by an impeller in the axial fan. It is characterized in that it extends close to a space area through which it does not pass.

[0009]

In the cooling mechanism of the present invention, the air blown by the impeller is directed in the axial direction by the baffle plate before being sent out from the axial fan. Therefore, the flow of air sent out from the axial fan is large in the axial direction and small in the circumferential direction, so that the amount of air flowing outward due to centrifugal force is small. As a result, the space between the axial fan and the component to be cooled is small. Also, the wind can sufficiently hit the component to be cooled, and the cooling effect can be maintained.

[0010]

Embodiments of the present invention will be described below. (Description of Structure of Liquid Crystal Projector) As shown in FIGS. 2 and 3, a liquid crystal projector (1) of the present embodiment is configured to project light from a light source (11) such as a halogen lamp or a metal halide lamp, and to project light from the light source (11). A liquid crystal panel (20) through which light passes,
Projection lens that enlarges and projects light that has passed through the liquid crystal panel (20)
(12) is deployed in the cabinet (10). The liquid crystal projector (1) of the present embodiment is a color liquid crystal projector, and is a three-panel type in which liquid crystal panels are provided for light of three primary colors of R (red), G (green), and B (blue), respectively. In addition, it is a prism system in which light modulated by each liquid crystal panel is synthesized by a dichroic prism.

The cabinet (10) of the liquid crystal projector (1)
A chassis (6) functioning as a light guide for guiding light from the light source (11) to the projection lens (12) is fixed to the chassis. The chassis (6) has dichroic mirrors (73a) and (73b) for separating the light from the light source (11) into R, G, and B colors, and liquid crystal panels (20) (20a) ( 20b), the dichroic prism (70), a total reflection mirror, various lenses, and the like are provided in place. Polarizing plates are provided on both sides of the liquid crystal panels (20) (20a) (20b). Polarizing plates have poor heat resistance, like liquid crystal panels. In particular, in the case of a liquid crystal projector, since the light from the light source (11) is strong, the polarizers (22), (22a), and (22b) on the incident side generate extremely large heat due to light absorption. LCD panel (20) (20a) (20b)
It is arranged facing away from. The transmission-side polarizing plate (analyzing plate) is bonded and provided to the liquid crystal panels (20), (20a), (20b) (not shown).

The light from the light source (11) is reflected by a total reflection mirror (72a).
In the dichroic mirror 73a, light of one of the three primary colors (here, red (R)) is transmitted, and light of the remaining two colors is reflected. The transmitted red light is reflected by the total reflection mirror (72b), is polarized by the polarizing plate (22a), and enters the liquid crystal panel (20a). On the other hand, the reflected light of the remaining two colors is reflected by the dichroic mirror (73b) in one color (here, green (G)) and transmitted in the other color (here, blue (B)). I do. The reflected green light is polarized by the polarizing plate (75) and enters the liquid crystal panel (20). The transmitted blue light is reflected by the total reflection mirrors (72c) (72d), is polarized by the polarizing plate (75b), and enters the liquid crystal panel (20b). Each liquid crystal panel
(20) The lights of the respective colors that have passed through (20a) and (20b) are combined in a dichroic prism (70), and the combined light is irradiated by a projection lens (12) and projected on a screen (not shown). .

(Description of Structure of Cooling Mechanism) As shown in FIG. 4, the liquid crystal panel (20) and the incident side polarizing plate (22) are held in place by holding mechanisms (21) and (23), respectively. (21) and (23) are fixed to the chassis (6). Chassis
In (6), the liquid crystal panel (20) and the incident side polarizing plate (22)
A blow opening (60) is opened in the lower area of. Also,
In the chassis (6), the liquid crystal panel (20), the incident side polarizing plate
Immediately below the area where the (22) and the dichroic prism (70) are provided, an axial fan (3) is provided, and the axial fan (3) is fixed to the opening (15) of the cabinet (10). Is done. Between the chassis (6) and the axial fan (3), in order to guide the air from the axial fan (3) to the chassis (6), a peripheral wall (4) for restricting air flowing radially outward is provided. Provided.
In order to cool the light source (11) by air, the peripheral wall (4)
A blowing wall (40) for guiding a part of the air from the axial fan (3) to the light source (11) is connected. In the present embodiment, the peripheral wall (4) and the blowing wall (40) extend from the chassis (6),
It is formed integrally with the chassis (6).

As shown in FIG. 1, the axial fan (3) includes a thin motor (32) on a frame (30) via a support rod (31).
Is provided, and an impeller (33) is provided below the thin motor (32). The impeller (33) is fixed to the main shaft of the motor (32) and rotates with the main shaft, and a hub (330) is mounted around the hub (330) to provide kinetic energy to the gas by rotational motion ( 331). The impeller (33) is rotated by the rotation drive of the motor (33), and the impeller (331) of the impeller (33) is rotated.
The wind is blown upward. As shown in FIG. 4, an air filter (16) for preventing dust and dirt in the air from entering the cabinet (10) is provided in the opening (15) of the cabinet (10).

The lower part of the chassis (6) has a blow opening (60).
Baffle plate to increase the flow rate of air blown from
(5) is deployed. As shown in FIGS. 1 and 4, the air guide plate (5) is formed by cutting and bending a metal plate, and includes a fixing portion (50) fixed to the chassis (6) and a fixing portion (50). And a bent air guide (51). A downstream portion (upper side in the figure) of the air guide portion (51) is provided with a blow opening (60) for guiding air from the axial fan (3) to the liquid crystal panel (20) and the polarizing plate, which are components to be cooled. Through the chassis (6)
Extends to the inside.

On the other hand, the upstream part (lower side in the figure) of the air guide part (51)
Extends in the inflow direction of the air to guide the air from the axial fan (3) to the blowing opening (60). The liquid crystal panel (20) and the polarizing plate, which are the components to be cooled, generate different amounts of heat due to light absorption depending on the color of incident light. Therefore, the liquid crystal panel (20) that generates a large amount of heat and the air guide (51) corresponding to the polarizing plate
In order to increase the flow rate of the air sent from the blowing opening (60), the upstream portion is extended to the inside of the axial fan (3). At this time, the upstream part of the air guide part (51)
Inside (3), it is extended to a position where the impeller (33) does not pass, for example, a region between the support rods (31) and a region around the motor (32). Furthermore, in order to increase the flow rate of the air sent from the blowing opening (60), the upstream part of the air guide part (51) is extended close to the region where the impeller (33) rotates. In the present embodiment, the blowing opening (60) is an axial fan (3).
Of the axial flow fan (3).
1) is formed by being bent in the upstream direction as going outward in the radial direction, so that the upstream side of the air guide portion (51) has a region between the support rods (31) and It extends to a position beyond the peripheral area of the motor (32). In this embodiment, in order to efficiently change the circumferential wind in the axial fan (3) in the axial direction, the upstream end of the air guide (51) is located in the circumferential direction of the axial fan (3). It is bent to the side receiving the wind.

In the cooling mechanism having the above structure, the axial fan
When the impeller (33) of (3) is driven to rotate, air flows in the axial direction and the circumferential direction are generated. This flow is a baffle plate (5)
And is directed in the axial direction. Therefore, the flow of the air sent from the axial flow fan (3) to the air guide portion (51) through the blowing opening (60) is large in the axial direction and small in the circumferential direction. Liquid crystal panel (20) and polarizing plate
Efficiently sent to (22). As a result, axial fans
Even if the distance between (3) and the liquid crystal panel (20) and the polarizing plate (22) is small, the liquid crystal panel (20) and the polarizing plate (22) can be sufficiently cooled.

The description of the above embodiments is for the purpose of describing the present invention, and should not be construed as limiting the invention described in the claims or reducing the scope thereof.
Further, the configuration of each part of the present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made within the technical scope described in the claims. For example, in the present embodiment, the liquid crystal projector (1) has been described.
The present invention can also be applied to other electronic devices in which components to be cooled are provided in the axial direction on the air blowing side in (3). Specifically, a personal computer in which an axial fan for cooling a CPU is installed on a CPU (central processing unit) is used.

[Brief description of the drawings]

FIG. 1 is an assembly diagram showing an axial fan and a baffle plate according to an embodiment.

FIG. 2 is a side view of a general liquid crystal projector.

FIG. 3 is a view of a chassis in the liquid crystal projector as viewed from above in a horizontal section.

FIG. 4 is a cross-sectional view of a principal part showing a cooling mechanism of the present embodiment in the liquid crystal projector.

FIG. 5 is a sectional view of a main part showing a conventional cooling mechanism in a liquid crystal projector.

[Explanation of symbols]

 (1) Liquid crystal projector (3) Axial fan (5) Baffle plate (20) Liquid crystal panel (33) Impeller (60) Inlet opening

Claims (3)

[Claims] 1. A component to be cooled such as a liquid crystal panel (20) is provided in an axial direction on an air blowing side of the axial fan (3).
In a cooling mechanism in which a wind guide plate for guiding the wind sent from the axial fan (3) to the cooled component is provided between (3) and the cooled component, upstream of the wind guide plate (5). A cooling mechanism characterized in that the edge on the side extends to a space region where the impeller (33) does not pass in the axial fan (3). 2. An axial fan having an upstream edge of the air guide plate (5).
The cooling mechanism according to claim 1, wherein the cooling mechanism is bent in the circumferential direction of (3). 3. An electronic device comprising the cooling mechanism according to claim 1.