JP3249455B2 - Light shielding structure of projection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light shielding structure for preventing light from leaking from a projection device, and more particularly to a liquid crystal projector having an image display device such as a liquid crystal panel.

[0002]

2. Description of the Related Art Conventionally, three primary colors of light, R, G, B
There has been proposed a liquid crystal projector having three liquid crystal panels corresponding to the above, irradiating these with strong light from a light source, synthesizing a light beam passing through the liquid crystal panel, and projecting an image on a screen. FIG. 3 is an overall plan view of the liquid crystal projector. Cabinet that covers the top of the LCD projector
A box-shaped chassis (3) for holding three liquid crystal panels is provided in (6), and a barrel of a projection lens (67) provided at a front end of the chassis (3) includes a cabinet ( 6) penetrates the front surface and projects outward.

In the chassis (3), liquid crystal panels (7a) and (7b) corresponding to R and B are provided so as to face each other with the optical axis of the projection lens (67) interposed therebetween. ) (7b), a prism body (30) is provided. The prism body (30) includes therein reflection layers (31) and (32) substantially orthogonal to each other, and corresponds to G on the side of the prism body (30) opposite to the projection lens (67). A liquid crystal panel (7) is provided. Chassis
A light source (35) is provided at the light path entrance to (3), and a total reflection mirror (75) (76) (77) (78) and a dichroic mirror (45) (46) are arranged on the light path in the light path direction. It is deployed at an angle. The dichroic mirror (45) passes R, and the dichroic mirror (46) reflects G and passes B.

The light from the light source (35) passes through a condenser lens (7
After passing through 9) and being reflected by the total reflection mirror (75),
R passes through the dichroic mirror (45), and G and B are reflected by the dichroic mirror (45). R is reflected by the total reflection mirror (76), passes through the polarizing plate (73), and irradiates the liquid crystal panel (7a) corresponding to R. LCD panel (7a)
Is irradiated toward the projection lens (67) by the reflection layer (32) in the prism body (30). G is reflected by the dichroic mirror (46) and enters the prism body (30), and the incident light passes through the prism body (30) as it is and enters the projection lens (67). B is reflected by the reflection layer (31) in the prism body (30) after being reflected by the total reflection mirrors (77) and (78), and enters the projection lens (67). Thus, R,
The three color lights of G and B are combined and projected on the screen (68).

Since the light source (35) irradiates with strong light, it tends to overheat. Therefore, a fan (5) is often provided between the cabinet (6) and the light source (35) to cool the light source (35) by air. However, the light of the light source (35) leaks from the fan (5), and the light may enter the eyes of the user of the projection device or the viewer of the screen (68) located near the light source (35). Hurts the eyes of users. Therefore, as shown in FIG. 4, a light shielding plate (8) having a large number of holes (80) may be provided on the air intake side of the fan (5) to prevent light leakage. Further, a light shielding body (2) as shown in FIG. 5 may be provided. A plurality of plate pieces (21) and (21) are tilted with respect to the light traveling direction in a frame body (20) having front and rear faces opened to face the fan (5), and are arranged in upper and lower stages. I have.

[0006]

The light shielding plate (8) shown in FIG.
When the air is provided to face the fan (5), when the air flowing into the fan (5) passes through the holes (80) and (80) of the light shielding plate (8), a wind noise is generated, and the user, etc. May cause discomfort.
Further, in the light shielding body (2) shown in FIG. 5, as shown in FIG. 6, even if it is possible to block light traveling straight from the light source (35),
As indicated by the dashed line, light traveling obliquely downward from the light source (35) is transmitted. In this case, it is conceivable to reduce the vertical distance between the plate pieces (21).
The amount of air flowing into the fan (5) from outside is reduced, and the fan (5)
Cooling efficiency is reduced. An object of the present invention is to efficiently block light from a light source without reducing the cooling efficiency of a fan.

[0007]

[MEANS FOR SOLVING THE PROBLEMS] A projection device comprises: a light source (35);
A fan (5) for cooling the light source (35) is provided, and a light shield (2) provided outside the fan (5) and blocking light leaked from the light source (35) through the fan (5). The light shield (2) is inside,
A plurality of light-shielding pieces (1) are arranged in upper and lower stages, and each light-shielding piece (1) is a horizontal piece extending along the horizontal light from the light source (35).
(10) and a horizontal piece (1) from the end of the horizontal piece (10) on the fan (5) side.
A vertical piece (11) extending perpendicular to (0), and an inclined piece (12) extending from the end of the horizontal piece (10) on the fan (5) side with respect to horizontal light.
Radially. Horizontal piece (10) of one shading piece (1)
A vertical gap L is formed between the horizontal piece (10) and the vertical piece (11) of the other light-shielding piece (1) opposed on the upper side or the lower side. The horizontal piece (10) extends to a position where the light obliquely inserted through the vertical gap L reaches, and the vertical gap L is
It is located within the vertical projection range of the inclined piece (12) of the one light shielding piece (1).

[0008]

[Operation and Effect] A horizontal piece (10) of one light-shielding piece (1) and a vertical piece (11) of another light-shielding piece (1) facing above or below the horizontal piece (10). The light obliquely inserted through the gap L reaches the horizontal piece (10) of the one light shielding piece (1) (see the dashed-dotted arrow in FIG. 2). Thus, the light does not directly enter the eyes of the user. Also, the vertical piece (1) of one light shielding piece (1)
The vertical gap L between 1) and the other light shielding piece (1) closest to the vertical piece (11) is located within the vertical projection range of the inclined piece (12) of the other light shielding piece (1). Therefore, horizontal light incident from below the inclined piece (12) does not pass through the vertical gap (FIG. 2).
). That is, light in any direction from the light source (35) is prevented from directly reaching the eyes of the user,
The safety of the user etc. can be achieved. Further, by providing the vertical gap L, air flows smoothly through the fan (5).

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an example of the present invention will be described in detail with reference to the drawings. The same components as those of the related art are denoted by the same reference numerals, and detailed description thereof is omitted. Figure 1 shows the light source (3
FIG. 5 is a perspective view of a fan (5) and a light shield (2). Light source (35)
The positional relationship between the projector and the entire projection apparatus is the same as that of the conventional projection apparatus shown in FIG. Light source (35) is box (36)
And a fan (5) is provided beside the light source (35). The air from the fan (5) cools the light source (35) through an opening (not shown) formed on the side of the box (36). Outside the fan (5), a light shield (2) for preventing light from leaking from the light source (35) is provided.

The present embodiment is characterized by the light shielding body (2). The light-shielding body (2) has a rectangular frame (20) on the outside, and an opening (22) is formed on a surface facing the fan (5). In the opening (22), a plurality of light shielding pieces (1) and (1) are arranged vertically, and the upper part of the uppermost light shielding piece (1) and the lower part of the lowermost light shielding piece (1) are closed. The light from (35) does not pass. In the following description, for convenience of explanation, three light shielding pieces are provided in the light shielding body (2).
(1) It is assumed that (1) and (1) are provided, the uppermost light-shielding piece (1) is a first light-shielding piece (1a), the middle light-shielding piece (1) is a second light-shielding piece (1b), The lowest light shielding piece (1) is the third light shielding piece (1c), but the number of light shielding pieces (1) is not limited to three.

FIG. 2 is a view of the light shield (2) viewed from the direction A in FIG. 1, and light from the light source (35) passes from the left side to the right side of the light shield (2). Each light shielding piece (1) is a horizontal piece (10) extending horizontally.
A vertical piece (11) extending downward from the end of the horizontal piece (10) on the fan (5) side perpendicular to the horizontal piece (10); and an end of the horizontal piece (10) on the fan (5) side. An inclined piece (12) extending obliquely upward from the part is radially provided. The horizontal piece (10), the vertical piece (11) and the inclined piece (12) are each made of a material that does not reflect or transmit light, for example, A
It is formed of a synthetic resin such as BS. The horizontal piece (10) of each light shielding piece (1) and the vertical piece (1
A vertical gap L is formed between the vertical gap L and 1). As shown in FIG. 2, the upper end of the inclined piece (12) of the second light shielding piece (1b) is located higher than the lower end of the vertical piece (11) of the first light shielding piece (1a). In other words, the vertical gap L is located within the vertical projection range of the inclined piece (12) of the second light shielding piece (1b). Therefore, the horizontal light passing above the inclined piece (12) of the second light shielding piece (1b) is always blocked by the vertical piece (11) of the first light shielding piece (1a). Thereby, the horizontal light is prevented from passing through the light shield (2), and the horizontal light does not directly enter the eyes of the user or the like. In addition, the third light shielding piece
The upper end of the inclined piece (12) of (1c) is the vertical piece of the second light shielding piece (1b).
It is located above the lower end of (11).
The horizontal light passing above the inclined piece (12) of the light shielding piece (1c)
The passage of the light shield (2) is prevented.

As shown by a dashed line B in FIG. 2, light obliquely inserted through the vertical gap L is transmitted to the third light shielding piece.
It reaches on the horizontal piece (10) of (1c). That is, the light obliquely inserted from the gap L irradiates the horizontal piece (10) of the third light shielding piece (1c), and the horizontal piece (10) does not reflect the light. Does not enter eyes directly. The second light shielding piece
A vertical gap L is also formed between the horizontal piece (10) of (1b) and the vertical piece (11) of the first light-shielding piece (1a). The horizontal piece (10) of the second light shielding piece (1b)
Reach the top.

Further, as shown in FIG. 2, an imaginary line connecting the tip of the vertical piece (11) of the light shielding piece (1) and the tip of the horizontal piece (10) is denoted by M. The lower end of the vertical piece (11) of the light-shielding piece (1) located above the light-shielding piece (1) is located below the virtual line M. As a result, the light obliquely inserted into the vertical gap L always irradiates the horizontal piece (10), and the light irradiated above the vertical gap L always irradiates the vertical piece (11). That is, the light does not directly enter the eyes of the user of the device.

From the above description, light from any direction from the light source (35) is blocked by the light shield (2) and does not directly enter the eyes of a user or the like. Further, by providing the vertical gap L, the air flows smoothly to the fan (5).

In the above example, the inclined piece (12) extends obliquely upward toward the fan (5) and the vertical piece (11) extends downward, as shown in FIG. And a vertical strip (1
1) may be extended upward, and the inclined piece (12) may be extended diagonally downward.

The description of the above embodiments is for the purpose of illustrating the present invention and should not be construed as limiting the invention described in the appended 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.

[Brief description of the drawings]

FIG. 1 is a perspective view of a light source, a fan, and a light shield.

FIG. 2 is a side view of the light shielding body viewed from a direction A in FIG.

FIG. 3 is a plan view of the projection device.

FIG. 4 is a perspective view of a conventional light source, fan, and light shielding plate.

FIG. 5 is a perspective view of a conventional light shield.

FIG. 6 is a side view of the light shield of FIG.

FIG. 7 is a side view of a light blocking body according to another embodiment.

[Explanation of symbols]

 (1) Shield (2) Shield (10) Horizontal (11) Vertical (12) Inclined (35) Light source

Continuation of the front page (56) References JP-A-8-101458 (JP, A) JP-A-8-69053 (JP, A) JP-A-6-59238 (JP, A) Japanese Utility Model Showa 60-156488 (JP) , U) Actually open 55-32859 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) G03B 21/00-21/30

Claims (3)

(57) [Claims] 1. A light source (35) and a fan for cooling the light source (35)
(5) and a light shield (2) disposed outside the fan (5) and shielding light leaked from the light source (35) through the fan (5). In (2), a plurality of light-shielding pieces (1) and (1) are arranged vertically and provided inside, and each light-shielding piece (1) is a horizontal piece (10) extending along the horizontal light from the light source (35). ), A vertical piece (11) extending perpendicularly to the horizontal piece (10) from an end of the horizontal piece (10) on the fan (5) side, and a horizontal piece (10).
A radially inclined piece (12) extending from the end of the fan (5) side with respect to horizontal light, and a horizontal piece (10) of one light shielding piece (1), and the horizontal piece (10) and the upper side Alternatively, a vertical gap L is formed between the light-shielding piece (1) and the vertical piece (11) facing the lower side, and the horizontal piece (10) forms the vertical gap L from the light source (35). The projection extends to a position where the obliquely inserted light that has passed through reaches, and the vertical gap L is located within the vertical projection range of the inclined piece (12) of the one light shielding piece (1). The light-shielding structure of the device. 2. A vertical piece (11) of each light shielding piece (1) is a horizontal piece (10).
The horizontal piece (10) extends downward from the end of the horizontal piece (10) perpendicular to the horizontal piece (10), and the inclined piece (12) extends upward from the fan (5) side end of the horizontal piece (10). 2. The light shielding structure of the projection device according to 1. 3. The tip of the vertical piece (11) of each light-shielding piece (1) is connected to the inclined piece (1) of the other light-shielding piece (1) whose tip of the vertical piece (11) faces.
From the virtual line M connecting the tip of 2) and the tip of the horizontal piece (10),
The light-shielding structure of the projection device according to claim 1, wherein the light-shielding piece (1) is located closer to the other light-shielding piece (1).