JP3357843B2 - 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 projection device for irradiating an image on a screen with strong light.

[0002]

2. Description of the Related Art Conventionally, three primary colors of light, R, G, B
It is equipped with three liquid crystal panels (7), (7a) and (7b) corresponding to, irradiates them with strong light from a light source (35), and synthesizes a light flux modulated by passing through the liquid crystal panel to form an image. There has been proposed a liquid crystal projector that projects the image. In the following description, the irradiation direction of the projection lens (5) is assumed to be forward. FIG. 5 is a plan view of the projection device, and FIG. 6 is a side sectional view of FIG. In the chassis (3), liquid crystal panels (7a) and (7b) corresponding to R and B are provided with the optical axis of the projection lens (5) interposed therebetween, and between the liquid crystal panels (7a) and (7b). A prism body (30) for combining R, G, and B lights is provided. Prism body (3
The liquid crystal panel (7) corresponding to G is mounted on the sub-chassis (36) fixed on the chassis (3), and on the opposite side of the projection lens (5) across the prism body (30). Is provided. An adjustment mechanism (100) for performing convergence adjustment described later is provided between each of the liquid crystal panels (7), (7a) (7b) and the prism body (30), and the detailed configuration of the adjustment mechanism (100) is as follows. ,
It has been disclosed by the applicant in Japanese Patent Application Laid-Open No. 9-61782. A light source (35) is provided at the light path entrance to the chassis (3), and a total reflection mirror (75) (76) (77) (78) and a dichroic mirror (45) (46) are provided on the light path. It is arranged at an angle of 45 degrees.

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), the dichroic mirror (45) allows the passage of R and reflects G and B. R is reflected by the total reflection mirror (76), irradiates the liquid crystal panel (7a) corresponding to R, and the prism body (3).
The light is reflected to the projection lens (5) and radiated toward the projection lens (5).
G is reflected by dichroic mirror (46) and prism
(30), and the incident light passes through the prism body (30) as it is and enters the projection lens (5). B is a total reflection mirror (7
7) After being reflected by (78), it is reflected by the prism body (30) and enters the projection lens (5). When the distance from the projection lens (5) to each of the liquid crystal panels (7), (7a) and (7b) varies, the light irradiated on the liquid crystal panels (7), (7a) and (7b) accurately reaches the projection lens (5). There is a possibility that the illuminance on the screen may be reduced without being incident. Therefore, the liquid crystal panels (7), (7a), (7b) are slightly moved back and forth along the optical axis. This is called back focus adjustment, and as shown in FIG. 6, the distance from the base end of the projection lens (5) to the liquid crystal panels (7) (7a) (7b) is called the back focus distance. This back focus distance is determined by the projection lens (5). Further, unless the optical axes of the respective lights entering the prism body (30) coincide with one point, an image cannot be accurately synthesized. Therefore, the liquid crystal panels (7) (7a) (7b)
Is rotated in the plane including the liquid crystal panel, and is adjusted in the vertical and horizontal directions. This adjustment is called convergence adjustment.

[0004]

In the prior art, FIG.
As shown in (1), the liquid crystal panels (7), (7a) and (7b) are mounted on the chassis (3) so that the back focus distance can be finely adjusted, and the prism body (30) does not move during the back focus adjustment. In such a projection device, various projection lenses (5) having different back focus distances may be used according to the distance from the device to the screen. Anyway,
If you try to attach another projection lens (5) with different back focus distance to one chassis (3), the liquid crystal panel
(7) Since the prism body (30) cannot be moved even though (7a) and (7b) can move, the prism body (30) and the liquid crystal panel (7) (7a)
The relative position of (7b) is shifted. As a result, an accurate image cannot be irradiated on the screen. Therefore, one chassis
(3) is a projection lens with one back focus distance
Only (5) can be attached, which is inconvenient in the production process of the device. An object of the present invention is to use a common chassis for various projection devices having different back focus distances and improve the productivity of the devices.

[0005]

On the chassis (3), an auxiliary base (20) is provided movably along the projection direction of the projection lens (5), and comprises a prism body (30) and a liquid crystal panel (7). ) (7a)
(7b) The adjusting mechanism (6) is mounted on the auxiliary base (20), and constitutes one optical path adjusting unit (2).
(20) is fixed by a jig inserted from above the chassis (3).
The distance from the liquid crystal panels (7) (7a) (7b) to the projection lens (5) is back-focused .

[0006]

[Function and effect] The prism body (30) and the liquid crystal panel (7) (7)
a) and (7b) are mounted on the auxiliary base (20), and the auxiliary base (20) is attached to the chassis (3) during back focus adjustment.
Moving up, the prism body (30) and the liquid crystal panel (7)
The relative positions of (7a) and (7b) do not change. Therefore, projection lenses with different back focus distances on one chassis (3)
(5) can be replaced and installed. This allows
The chassis (3) can be shared, and the productivity of the device is improved.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. The same reference numerals are used for the same configuration as the conventional one. FIG. 1 shows a projection lens (5) and an adjusting mechanism according to this embodiment.
(6) is a side sectional view, and FIG. 2 is a plan view of the same.
The arrangement of other optical components such as a dichroic mirror is the same as in FIG. The projection lens (5) is a chassis
Fitted on the front end of (3), prism body (30), adjustment mechanism
(6) The liquid crystal panel (7) is mounted on an auxiliary base (20) provided on the chassis (3), and constitutes one optical path adjusting unit (2). The prism body (30) has a peripheral surface other than the front surface covered with a cover (31).
Then, the cover (31) is not shown. The adjustment mechanism (6) is attached to the prism body (30), and a liquid crystal panel (7) is attached to the opposite side of the prism body (30) with the adjustment mechanism (6) interposed therebetween.

The auxiliary base (20) has a pin protruding from the bottom.
(21) is detachably fitted in a guide groove (22) extending along the irradiation direction of the projection lens (5) on the chassis (3), and the back is adapted to the type of the projection lens (5). Focus adjustment is possible. As shown in FIG. 2, a notch (23) is provided at the front end of the auxiliary base (20), and a recess (32) overlapping the notch (23) is provided in the chassis (3). Notch (2
3) Insert a jig (not shown) into the concave portion (32) from above , move the optical path adjustment unit (2) back and forth, and finely adjust the back focus distance. By moving the optical path adjusting unit (2) back and forth, the liquid crystal panel (7) corresponding to R from the projection lens (5) is moved.
(a) Since the distance to the liquid crystal panel (7b) corresponding to B also changes, the back focus is adjusted for each liquid crystal panel (7) (7a) (7b). The actual back focus adjustment is
The adjustment is made while illuminating the light source (35) (see FIG. 5) while observing the illuminance on the screen. The convergence adjustment is performed by the adjustment mechanism (6).

FIG. 3 is an exploded perspective view of the adjusting mechanism (6), and shows the adjusting mechanism (6) attached to the liquid crystal panel (7) corresponding to G light for convenience of explanation. FIG. 4 shows the adjusting mechanism.
It is the front view which looked at (6) from the prism body (30) side. R light,
Needless to say, the same adjustment mechanism (6) is provided on the liquid crystal panels (7a) and (7b) corresponding to the B light. Adjustment mechanism (6)
The upper and lower adjustment plate (60), the fixed plate (61), left and right adjustment plate (8), the four plate material of the rotation adjustment plate (80) is constituted by overlapping with a fastener (90), the outermost The liquid crystal panel (7) is mounted outside the rotation adjusting plate (80) located. Each panel has a liquid crystal panel
Openings (91c) (91b) (91a) (9
1) has been established. Inward from the fixing plate (61), the first
The holding plate (62) protrudes, and the first holding plate (62) is
It is attached to the top surface of the cover (31) through the through hole (63) opened in (0). The lower end of the fixing plate (61) forms a second holding plate (64) bent outward and fixed to the upper surface of the auxiliary base (20).

The upper end of the left and right adjusting plate (8) is provided with a prism (3).
0) to form a first horizontal plate (81), and open a long hole (82) extending along the optical axis of the liquid crystal panel (7) on the first horizontal plate (81). are doing. The slot on the first horizontal plate (81)
A first eccentric shaft (85) is provided on the side of (82). The upper end side of the rotation adjusting plate (80) is bent inward to form a second horizontal plate (83), and the liquid crystal panel (7) is placed on the second horizontal plate (83).
A long hole (84) extending along the optical axis is provided. A second eccentric shaft (65) protrudes from the upper end of the vertical adjustment plate (60), and a screw hole (66) is formed on the side of the second eccentric shaft (65). At the upper end of the fixing plate (61), adjust screw (9)
The screw portion of the adjusting screw (9) is provided with an upper and lower adjusting plate (60).
Screw holes (66). At the upper end of the left and right adjusting plate (8), a protruding shaft (86) is provided outward, and the protruding shaft (86) is obliquely formed in the rotation adjusting plate (80). ) (87). Shaft (67) provided outward from the vertical adjustment plate (60)
Is fitted into the hole (68) formed in the fixing plate (61) with a margin, and after passing through the vertical hole (88) formed in the left and right adjusting plate (8), the rotation adjusting plate (80) Fits tightly in the hole (89) opened at

The second eccentric shaft (65) is provided with the left and right adjusting plate.
(8) When the second eccentric shaft (65) is fitted into the long hole (82) and the second eccentric shaft (65) is rotated, the peripheral surface of the second eccentric shaft (65) pushes the side edge of the long hole (82), and the left and right adjusting plate (8) moves right and left. The rotation adjustment plate (80) and the liquid crystal panel (7) overlapping the left and right adjustment plate (8) also move left and right. The first eccentric shaft (85) is a rotation adjusting plate.
When the first eccentric shaft (85) is fitted into the long hole (84) of the (80) and the first eccentric shaft (85) is rotated, the long hole (87) of the rotation adjusting plate (80) is
It moves along the protruding axis (86) of (8), and the rotation adjusting plate (80) and the liquid crystal panel (7) rotate. When the adjusting screw (9) is turned, the upper and lower adjusting plate (60) screwed to the adjusting screw (9) moves up and down. The projecting shaft (67) of the vertical adjustment plate (60) penetrates through the fixed plate (61) and the left and right adjustment plate (8) with a margin in the vertical direction. ) Does not move up and down.
0) and the liquid crystal panel (7) goes up and down. In this way, convergence adjustment is performed.

In the production process of such a projection device, a liquid crystal panel
(7) Dust may adhere to (7a) and (7b) and the prism body (30), and the prism body (30) may need to be replaced in order to remove the dust. At this time, it is sufficient to replace the entire optical path adjustment unit (2). If the convergence of the liquid crystal panels (7), (7a) and (7b) is adjusted in advance for the replacement optical path adjustment unit (2), the convergence adjustment is performed after attaching the optical path adjustment unit (2) to the chassis (3). No adjustment is required.

In this embodiment, the prism body (30) and the liquid crystal panels (7) (7a) (7b) are both mounted on the auxiliary base (20). When adjusting the back focus, the auxiliary base (2
0) moves on the chassis (3), so when adjusting the back focus, the prism body (30) and the liquid crystal panels (7), (7a) (7)
The relative position of b) does not change. Therefore, one chassis
The projection lens (5) having a different back focus distance can be replaced and attached to (3). As a result, the chassis (3) can be shared, and the productivity of the device is improved.

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 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 side sectional view of a projection lens, a prism body, and an adjustment mechanism.

FIG. 2 is a plan view of a projection lens, a prism body, and an adjustment mechanism.

FIG. 3 is an exploded perspective view of an adjustment mechanism.

FIG. 4 is a front view of the adjusting mechanism as viewed from a prism body side.

FIG. 5 is a plan view of a conventional chassis.

FIG. 6 shows a projection lens, a prism body, and an adjustment mechanism of FIG.
It is the side surface sectional view seen from the direction.

[Explanation of symbols]

 (2) Optical path adjustment unit (3) Chassis (5) Projection lens (6) Adjustment mechanism (7) Liquid crystal panel (20) Auxiliary base (30) Prism

Claims (2)

(57) [Claims] 1. A liquid crystal panel (7) (7a) (7b) provided on a chassis (3) for each of R, G, and B lights, and each liquid crystal panel (7) (7a) ( 7b) a prism body (30) for synthesizing the R, G, and B light irradiated, a projection lens (5) for irradiating the screen with the light synthesized by the prism body (30), and a prism body (30). Provided between the liquid crystal panels (7), (7a) and (7b), the liquid crystal panels (7), (7a) and (7b) are moved in a plane perpendicular to the optical axis and perpendicular to the upper surface of the chassis (3). Adjusting mechanism (6)
In the projection device equipped with the above, on the chassis (3),
An auxiliary base (20) is provided movably along the projection direction of the projection lens (5), and includes a prism body (30) and a liquid crystal panel (7).
(7a) (7b), the adjustment mechanism (6) is mounted on the auxiliary base (20) , and constitutes one optical path adjustment unit (2), and the auxiliary base (20) is located above the chassis (3). Inserted from
A projection apparatus wherein the distance from the liquid crystal panels (7), (7a), (7b) to the projection lens (5) is adjusted by back focus by being moved by a jig . The optical path adjusting unit (2) is detachably mounted on a chassis (3), and the back focus adjustment is performed by an auxiliary base.
Notch (23) opened in the base (20) and the chassis (3).
The projection device according to claim 1, wherein the projection is performed by inserting a jig into the recessed portion (32) .