JP2940740B2 - Lcd video projector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projector for projecting an image on a screen and using a liquid crystal as an image display device.

[0002]

2. Description of the Related Art Japanese Patent Laid-Open No. 61-15048 discloses a liquid crystal projector using a liquid crystal display device.
No. 7, JP-A-64-74585 and the like have been proposed. FIG. 6 shows an example of the liquid crystal projector. A first color separation dichroic mirror (1) that transmits green and red light components and reflects blue light components is disposed in front of the light source (5), and is reflected by the color separation dichroic mirror (1). The blue component is further reflected by the total reflection mirror (4) and is incident on the first liquid crystal light valve (2).

A first color synthesizing dichroic mirror (3) and a second color synthesizing dichroic mirror (32) are provided in front of the first liquid crystal light valve (2). In front of the first color separation dichroic mirror (1), there is disposed a second color separation dichroic mirror (12) that transmits a red light component but reflects a green light component. The green component reflected by the mirror (12) enters the second liquid crystal light valve (22).

The light passing through the second light valve (22) enters the first dichroic mirror (3) for color synthesis,
The light is combined with the light passing through the first liquid crystal light valve (2).
The red component transmitted through the second color separation dichroic mirror (12) is incident on a third light valve (23). The third above
Light passing through the liquid crystal light valve (23) is a total reflection mirror (42)
Reflected by the second color dichroic mirror (32)
And is combined with the light transmitted through the first color combining dichroic mirror (3).

The light combined by the second color combining dichroic mirror (32) is magnified by the projection lens (51) and projected on a screen (not shown). Each of the dichroic mirrors (1) (12) (3) (32) and the total reflection mirrors (4) (42)
Are arranged at 45 ° to the optical axis, and each light valve
(2) (22) and (23) are arranged at right angles to the optical axis.
In addition, the first to third liquid crystal light valves (2), (22), (23)
Is controlled by a known control circuit (not shown).

The above dichroic mirrors (1), (12) and (3)
(32) and the reflection mirrors (4) and (42) are fixed to the mounts (11) and (31), respectively, and the mounts (11) and (31) are cantilevered on the vertical chassis (9) made of die-cast aluminum. Have been. In the case of the above liquid crystal projector, dichroic mirrors (1) (12)
(3) The mounting accuracy of (32) and the reflecting mirrors (4) and (42) is affected by the dimensional accuracy of the chassis (9) and the mounting bases (11) and (31).
In some cases, adjustment is required. In addition, the number of parts is large, which leads to an increase in cost.

A dichroic mirror is mounted on a box-shaped chassis,
A liquid crystal projector incorporating components including a total reflection mirror has also been proposed. In this case, the dichroic mirror and the total reflection mirror are supported by a mounting portion formed on a box-type chassis, so that the dichroic mirror and the total reflection mirror can be used. The mounting accuracy is determined solely by the dimensional accuracy of the box-type chassis, and the mounting accuracy of the dichroic mirror and the total reflection mirror is higher than in the case of FIG. 6, but the manufacturing cost of the box-type chassis is extremely high. There is. The invention clarifies a liquid crystal projector that solves the above problem.

[0008]

A liquid crystal projector according to the present invention comprises three liquid crystal light valves (2) and (22) for forming an image.
(23), dichroic mirrors (1) (12) and total reflection mirrors (4) (42) for color separation of light into three primary colors, dichroic mirrors (3) (32) for color image synthesis, light source ( 5) and a projection lens (51), the dichroic mirrors (1), (12), (3) and (3)
2), each reflection mirror (4) (42) and each liquid crystal light valve (2)
(22) and (23) are arranged between the pair of side plates (6) and (6), and each side plate
(6) In (6), each dichroic mirror (1) (12) (3) (32)
A long hole (61) for fitting and supporting both side edges of each total reflection mirror (4) (42) is opened at a symmetrical position, and the mirrors (1) (12) (3) (3)
Both ends of (2) are fitted into the long holes (61), and the holding member (7) is placed from the outside of the side plate (6) so that the long holes (61) have a margin in the width direction of the holes.
The mirror is pressed by a spring piece (73) formed in the holding member (7), and the slot (61) is opened in the holding member (7).
A screw (75) fitted in a screw insertion hole (76) which is long in a direction perpendicular to the longitudinal direction is screwed into a screw hole (63) of the side plate (6) to fix the mirror.

[0009]

[Function and effect] Using an appropriate jig, two side plates (6)
Position (6) the corresponding slots (61) and
(8), the dichroic mirrors (1), (12), (3), (32) and the total reflection mirror (4) straddling the long holes (61) (61) of the side plates (6) (6). ) Just by fitting both sides of (42), mirror (4)
(42) can be positioned correctly. The side plates (6) and (6) can be manufactured easily and efficiently by, for example, punching a metal plate.
Since the total number of parts can be reduced, the cost can be reduced.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, between a pair of side plates (6), (6)
First and second dichroic mirrors (1) and (12) for color separation,
First and second dichroic mirrors (3) and (32) for color synthesis,
Total reflection mirrors (4) and (42) (hereinafter, dichroic mirrors for color separation, dichroic mirrors for color synthesis and total reflection mirrors are collectively referred to simply as mirrors) and first, second, and second mirrors Three liquid crystal light valves (2), (22) and (23) are provided. These mirrors (1) (12) (3) (32) (4) (42) and the light source
(5) The arrangement of the projection lens (51) is publicly known, including the conventional example shown in FIG.

The side plates of the embodiment are formed by stamping and pressing a metal plate. Each of the side plates (6) and (6) has a mirror (1) (12) (3) (32) (4) (42). ), Liquid crystal light valve (2)
(22) Elongate holes (6
1) is established.

The two side plates (6) and (6) are connected in parallel by a plurality of pipe stays (8) arranged at positions deviated from the optical path, and at an interval slightly smaller than the width of each mirror. I have. An inner screw (81) is formed at an end of the stay (8),
A screw insertion hole is formed in the side plate (6) (6) at a position corresponding to the stay, and a screw (82) inserted into the screw insertion hole from the outside of the side plate (6) (6) is screwed into the stay (8). Then, the side plates 6 and 6 and the stay 8 are fixed.

A plurality of receiving pieces (62) are formed on the lower edge of the upper three slots for mounting mirrors (61) on each of the side plates (6) and (6). A plurality of receiving pieces (62) are formed on the upper edge of (61a). Each receiving piece (62)
The side plates (6) are located on a line inclined by 45 ° with respect to the lower edge of the (6). In the vicinity of the long hole (61), a plurality of screw holes (63) are formed at positions facing the receiving piece (62).

Mirrors (1) (12) (3) (32) (4) (4)
The end of 2) is fitted, and the mirror (4) (42) is held by the holding member (7).
It is pressed against the receiving piece (62). The holding member (7) of the embodiment is
A metal plate is formed by stamping and bending of a press, and two bent pieces (7
2) A (72) is formed, and spring pieces (73) (73) (73) are protruded from both ends of one bent piece (72) and one end of the other bent piece (72).

The distance between the spring pieces (72) and (72) is
2) It corresponds to the interval between (62). Both ends of the mounting plate (71) are bent outward, and the lower end extends inward perpendicular to the plate surface of the mounting plate (71) to form a contact piece (74). The spacing between the hitting pieces (74) is slightly larger than the vertical length of each mirror.

Therefore, the assembly of the side plates (6) and (6) and the mirror
(4) At the time of mounting (42), fix the two side plates (6) and (6) with the stays (8) by aligning the positions of the corresponding long holes (61) with an appropriate jig. I do. Slots (61) on both sides (6) (6)
The two side edges of the mirrors (1), (12), (3), (32), (4), and (42) are fitted to each other, and the holding member (7) is fitted in the long hole (61). 7) Touch the lower contact piece (74). A screw (75) is fitted into the screw insertion hole (76) of the holding member (7), and the side plate (6)
Into the screw hole (63). At this time, the pressing member (7) is pressed against the mirror, and the screw (75) is tightened while the spring piece (73) presses the mirror to position the mirror.

The receiving piece (63) of each of the long holes (61) is provided with a side plate (6) (6).
Since the angle is set to 45 degrees with respect to the lower edge of the side plate, if the pair of side plates (6) and (6) are correctly aligned when they are connected by the stay, the mirror can be moved to the side plates (6) and (6). The angle of the mirror can be correctly positioned only by fitting the long hole (61) into the receiving piece (62). Mirror (1) (12) (3) (32)
(4) The positioning in the height direction of (42) is performed by the lower end of the mirror hitting the contact piece (74) of the holding member (7).
Vertical displacement of the mirror does not affect performance as much as angular displacement.

The liquid crystal light valves (2), (22) and (23) can be mounted in the same manner as the mirrors (1), (12), (3), (32), (4) and (42). Since it is not required to be as precise as the positioning of the mirror, other mounting methods are possible.
As described above, mirrors (1) (12) (3) (32) (4) (4
2) is fixed to the mounts (11), (31), and (41) and the mount is cantilevered on the vertical chassis (9). ) (32) (4) (42) with a pair of side plates
(6) It can be positioned simply by fitting over the long hole (61) of (6) and hitting the receiving piece (62) formed at the edge of the hole, thereby reducing the number of parts and cost.

Further, the positioning accuracy of the mirrors (1), (12), (3), (32), (4) and (42) depends on the position of the long hole (61) of the side plates (6) and (6) and the pair of side plates (6). 6) Because it depends only on the assembly accuracy of (6),
Since the side plates 6 and 6 are stamped and formed by a press and assembled correctly, it is not necessary to adjust the positioning of the mirror as in the related art. Further, the side plates 6 and 6 can be easily and efficiently manufactured by, for example, punching a metal plate, and the cost can be further reduced as compared with the case where a conventional aluminum die-cast chassis is used. The present invention is not limited to the configuration of the above embodiment, and various modifications are possible within the scope of the claims.

[Brief description of the drawings]

FIG. 1 is an oblique view showing a mounting state of a mirror.

FIG. 2 is a front view of a side plate.

FIG. 3 is an explanatory view showing a state where a mirror is pressed by a pressing member.

FIG. 4 is a sectional view taken along line AA of FIG. 3;

FIG. 5 is a perspective view of a holding member.

FIG. 6 is a perspective view showing a state of attachment of a conventional mirror.

[Explanation of symbols]

 (1) First color separation dichroic mirror (12) Second color separation dichroic mirror (3) First color combining dichroic mirror (32) Second color combining dichroic mirror (4) Total reflection mirror (42) Total reflection mirror (6 ) Side plate (61) Slot (62) Receiving piece (7) Holding member

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G02F 1/13 505 G02B 7/198

Claims (2)

(57) [Claims] 1. A liquid crystal light valve (2), (22), (23) for forming an image, a dichroic mirror (1) (12) for separating light into three primary colors, and a total reflection mirror (4). ) (42), dichroic mirrors for color image synthesis (3) (32),
In a liquid crystal video projector comprising a light source (5) and a projection lens (51), each of the dichroic mirrors (1) (1)
2) (3) (32), each reflection mirror (4) (42) and each liquid crystal light valve (2) (22) (23) are arranged between a pair of side plates (6) (6), and each side plate (6) In (6), each dichroic mirror (1) (1
2) (3) (32) and long holes (61) for fitting and supporting both side edges of each total reflection mirror (4) (42) are opened at symmetrical positions, and mirror (1)
(12) Both ends of (3) and (32) are fitted into the long holes (61), and the holding member (7) is set from the outside of the side plate (6) so that the long holes (61) have a margin in the width direction of the holes. ), And presses the mirror by a spring piece (73) formed in the holding member (7), and is opened in the holding member (7) and is elongated in a direction orthogonal to the longitudinal direction of the long hole (61).
A liquid crystal video projector in which a screw (75) fitted to (76) is screwed into a screw hole (63) of a side plate (6) to fix a mirror. 2. A dichroic mirror (1) (12) (3) (32)
The side edge of the total reflection mirror (4) (42) is pressed and fixed by a spring-acting holding member (7) attached to the side plate (6) (6). LCD video projector.