JP3090282B2 - Projector optical system adjustment mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to a projector which projects an image emitted from an image display means such as a cathode ray tube (hereinafter referred to as "CRT") onto a screen via a lens system and adjusts the optical system. It relates to a system adjustment mechanism.

[0002]

2. Description of the Related Art When an optical system such as a distance between a lens system and a screen changes when an image is projected on a screen by a projector having a lens system provided on a front surface of the CRT, the CRT and the lens are changed. It is necessary to change the back focus length (BFL), which is the distance from the system. Conventionally, a spacer is inserted between the CRT and the lens system to adjust the BFL.

[0003]

However, according to the above-described conventional optical system adjusting mechanism, a spacer corresponding to each projection system such as a screen size is required, and the projection system is limited. In addition, the projector cabinet must be opened to replace the spacer, and the lens mounting screws must be loosened and removed, which is troublesome. Moreover, fine adjustment was not possible.

The present invention has been made in view of such circumstances, and provides a projector optical system adjustment mechanism that can easily perform BFL adjustment without requiring a spacer or the like and that can perform fine adjustment. The purpose is to do.

[0005]

A projector optical system adjusting mechanism according to the present invention is a projector optical system adjusting mechanism for projecting an image emitted from an image display means onto a screen via a lens system. One supporting means, a second supporting means for supporting the lens system, and one of the pair of supporting means movably connected in the optical axis direction via a plurality of screw members, and the other supporting means. And a linking means for synchronously rotating a plurality of screw members.

[0006]

In the projector optical system adjusting mechanism having the above-mentioned structure, the plurality of screw members connecting one of the support means and the moving member are rotated synchronously via the interlocking means, so that the image display means is provided. And the lens system can be moved in parallel with each other. Therefore, the BFL, which is the distance between the image display means and the lens system, can be easily adjusted according to the number of rotations of the screw member.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the projector optical system adjusting mechanism of the present invention will be described below with reference to the drawings. FIG. 1 shows the configuration of one embodiment of the present invention. In FIG. 1, a CRT 1 as an image display means is a CRT coupler 2 as a first support means.
The CRT coupler 2 is attached to a chassis of a projector (not shown). Screws 3 for BFL adjustment, which are screw members, are rotatably supported in the vicinity of the four corners of the CRT coupler 2, and one end of each of the four screws 3 is formed with an outer diameter screw 3a. The screw 3 is screwed into a screw hole 4a formed near four corners of a moving plate 4 for BFL adjustment, which is a moving member, via an outer diameter screw 3a.
By rotating the four screws 3, the distance between the CRT coupler 2 and the moving plate 4 can be arbitrarily adjusted.

At the center in the width direction of the upper and lower sides of the moving plate 4, a horizontal rotating shaft 5 is provided in the vertical direction, and the middle frame 6 is supported rotatably in the horizontal direction via the rotating shaft 5. I have. In the vicinity of one corner of the middle frame 6, a screw 7 for adjusting the angle in the horizontal direction, the tip of which is engaged with the movable plate 4, is screwed.

At the center of the left and right sides of the middle frame 6 in the vertical direction, a vertical rotation shaft 8 is provided to project in the horizontal direction, and a lens coupler 9 as a second support member is provided via the rotation shaft 8. It is supported rotatably in the vertical direction. At the center of the upper side of the lens coupler 9 in the width direction, an angle adjusting screw 10 whose front end is engaged with the middle frame 6 is screwed.
A lens system 11 is attached to the lens coupler 9. Furthermore, CRT coupler 2 and lens coupler 9
Between the CRT coupler 2 and the lens coupler 9, a bellows 12 formed in a flexible cylindrical shape is provided between the CRT coupler 2 and the lens coupler 9. Are connected in a liquid-tight manner via O-rings 13 and 14, respectively. And Velofram 12 and CRT
A transparent liquid for cooling is sealed in a space defined by the lens system 1 and the lens system 11.

The same type of sprocket 15 as the interlocking means is fixed concentrically to one end of the four BFL adjusting screws 3 on the CRT 1 side, and the four sprockets 15 are connected to the chain 16 as the interlocking means. Thus, they rotate in synchronization.

Next, the operation of this embodiment will be described. Moving plate 4
Is mounted parallel to the CRT coupler 2 and one B
By rotating the FL adjusting screw 3, the other three screws 3 also rotate synchronously via the sprocket 15 and the chain 16. Therefore, the moving plate 4 is the CRT coupler 2
Translates with respect to. The screw 3 may be rotated manually, or a stepping motor may be used. As a result, the lens system 11 attached to the movable plate 4 via the middle frame 6 and the lens coupler 9 can move with respect to the CRT 1 to adjust the BFL.

By rotating the screw 7 for adjusting the angle in the horizontal direction, the center frame 6 is rotated about the horizontal rotation axis 5.
Rotates in the horizontal direction, and the horizontal tilt angle of the lens system 11 can be adjusted. Further, by rotating the screw 10 for adjusting the angle in the vertical direction, the lens coupler 9 rotates in the vertical direction about the vertical rotation axis 8, and the vertical tilt angle of the lens system 11 can be adjusted. Further, a tensile stress acts between the CRT coupler 2 and the lens coupler 9 by the metal bellofram 12,
The backlash of the screws 3, 7, 10 is absorbed.

According to this embodiment, the four BFL adjusting screws 3 rotate synchronously via the sprocket 15 and the chain 16, so that the moving plate 4 moves parallel to the CRT coupler 2 and the BFL Can be smoothly and easily adjusted without using a spacer or the like. Moreover, fine adjustment is possible, and the mounting strength between the CRT coupler 2 and the movable plate 4 can be improved.

In the above embodiment, the case where the number of the BFL adjusting screws 3 is four has been described, but the number of the screws 3 is not limited to four, and may be, for example, three. Also CRT
By inserting a compression coil member between the coupler 2 and the lens coupler 9, the bellofram 12 can be formed of a soft member. Further, the moving plate 4 is fixed to the chassis of the projector, and the CRT coupler 2 is moved by the same mechanism.
The moving plate 4 may be moved in parallel. The image display means is not limited to the CRT 1, but may be, for example, an LCD. Further, the interlocking means is not limited to the combination of the chain 16 and the sprocket 15.

[0015]

As described above, according to the projector optical system adjusting mechanism of the present invention, the first support means for supporting the image display means and the second support means for supporting the lens system are provided. The two screw members are connected so as to be relatively movable, and these screw members are rotated synchronously by the interlocking means, so that the BFL, which is the distance between the pair of support means, can be smoothly and easily adjusted. And fine-tuning is possible. Moreover, the reliability of the lens holding function can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view, partly in section, showing the configuration of an embodiment of a projector optical system adjusting mechanism according to the present invention.

[Explanation of symbols]

 Reference Signs List 1 CRT (image display means) 2 CRT coupler (first support means) 3 BFL adjustment screw (screw member) 4 Moving plate (moving member) 9 Lens coupler (second support means) 11 Lens system 15 Sprocket (interlocking) Means) 16 Chain (interlocking means)

──────────────────────────────────────────────────続 き Continuation of the front page (56) References Japanese Utility Model Showa 64-51385 (JP, U) Japanese Utility Model Showa 57-78174 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03B 21/00 G02B 7/02 H04N 5/74

Claims (1)

(57) [Claims] 1. A projector optical system adjusting mechanism for projecting an image emitted from an image display means onto a screen via a lens system, wherein the first support means supports the image display means and the second support means supports the lens system. Two supporting means,
A moving member connected to one of the pair of support means so as to be movable in the optical axis direction via a plurality of screw members and to which the other support means is mounted, and the plurality of screw members are provided. A projector optical system adjustment mechanism provided with interlocking means for rotating the projector in synchronization with the projector.