JPH04352142A - Projector - Google Patents

Abstract

PURPOSE:To improve the reliability of focus adjustment. CONSTITUTION:The projector is equipped with a 1st holder 11 which holds a CRT 16 and a 2nd holder 23 which holds a lens assembly provided in a swinging state in front of the 1st holder 11, the 2nd holder 23 is provided with spherical convex parts 24a and 25a arround an optical refernce point O, and the 1st holder 11 is provided with spherical concave parts 19a and 20a matching with the spherical convex parts 24a and 25a. Consequently, when the shift angles of the CRT 16 are adjusted for variation of a projection system, the 2nd holder 23 (spherical convex parts 24a and 25a) or 1st holder 11 (spherical concave parts 19a and 20a) rotate on the optical reference point O, so the shift angles of the CRT 16 can finely be adjusted without shifting the optical reference point O each time the shift angles are adjusted.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projector that projects an image onto a screen.

0002

[Prior Art] Generally, this type of projector transmits one image information to three colors of red, green, and blue, as shown in FIG.
A projection system that includes three cathode ray tubes a to c that separately project images separated into two color elements, and three lenses e to g that are provided in front of each of these cathode ray tubes a to c and project the image onto a screen d. Those equipped with units A to C are widely known.

In such a projector, the projection axes of the projection units A to C are tilted relative to each other so that the images from the cathode ray tubes a to c coincide at a certain point on the screen d.

By the way, in this type of projector, the lens convergence angle θ1 and the launch angle change with changes in the projection system such as the screen size, projection distance, or projection angle. It is necessary to adjust the focus at the center of the screen and the focus at the periphery of the screen by changing the angle θ2 and the vertical tilt angle.

Furthermore, by sealing a cooling liquid (not shown) for optical coupling between the cathode ray tubes a to c and the lenses e to g, the light emitted by the cathode ray tubes a to c is returned to the phosphor screen. It is also necessary to prevent the contrast from decreasing in the projected image.

[0006] For this reason, some projectors have been disclosed in the prior art, for example, in Japanese Utility Model Application Publication No. 1-115145 as a ``projection tube for a projection type television apparatus.'' This will be explained based on FIG. 5. In the figure, the reference numeral 1 denotes a cathode ray tube having an annular spacer 2, 3 a lens provided in front of the cathode ray tube 1 and having an annular spacer 4, and 5 a lens. This is an annular rubber tube as a coupler interposed between the spacer 4 of No. 3 and the spacer 2 of the cathode ray tube 1. This rubber tube 5
A liquid 6 for optically coupling the cathode ray tube 1 and the lens 3 is sealed in both the spacers 2 and 4. Further, 7 is an adjustment screw for adjusting the tilt angle of the cathode ray tube 1. Note that 8 is a first O-ring interposed between the cathode ray tube 1 and the spacer 2, and 9 is a second O-ring interposed between the lens 3 and the spacer 4.

In the projector constructed as described above, the tilt angle of the cathode ray tube 1 can be adjusted by deforming the rubber tube 5 using the adjusting screw 7.

[0008]

However, in conventional projectors, when adjusting the tilt angle of the cathode ray tube 1, the cathode ray tube 1 is simply oscillated. The optical reference point was changing. As a result, the tilt angle cannot be finely adjusted, and the reliability of focus adjustment around the screen deteriorates.

The present invention has been made in view of the above circumstances, and allows the tilt angle of the projection tube to be adjusted.
The present invention provides a projector that can improve reliability in focus adjustment.

0010

[Means for Solving the Problems] A projector according to the present invention includes a first holder that holds a projection tube, and a second holder that is swingably provided in front of the first holder and holds a lens. The second holder is provided with a first spherical guide centered on the optical reference point, and the first holder is provided with a second spherical guide that matches the first spherical guide.

[0011]

In the present invention, the first spherical guide or the second spherical guide rotates about the optical reference point when adjusting the tilt angle of the projection tube due to a change in the projection system.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the structure of the present invention will be explained in detail with reference to embodiments shown in the drawings.

FIG. 1 is a sectional view showing a main part of a projector according to the invention, FIG. 2 is a perspective view showing a part of the projector according to the invention in cross section, and FIG. 3 is a perspective view showing a coupler according to the invention. be. In the figure, code 1
1 is a first holder for holding a cathode ray tube (hereinafter referred to as "CRT"), which has a through hole 12a that is open on both sides and an annular groove 1 that is open at the periphery of both openings of this through hole 12a.
2b, 12c in the center thereof, and two end plates 13, 14 having guide grooves 13a, 14b integrally provided at the upper and lower ends of this substrate 12 and extending in the front-rear direction.
It is formed by a U-shaped holder when viewed from the side.

The substrate 12 of the first holder 11 is provided with a frame-shaped positioning convex portion 15 that protrudes from the opening periphery of the CRT side annular groove 12b of both the annular grooves 12b and 12c. A CRT 16 as a projection tube is mounted inside the convex portion 15.

Further, a first holding piece 17 that projects laterally is integrally provided at the center of one side edge of the first holder 11. As shown in FIG.

Reference numeral 18 denotes a first O-ring as a sealing member, which is installed in the annular groove 12b of the annular grooves 12b and 12c, and is connected to the CRT 16 and the first holder 11.
(substrate 12).

19 and 20 are spherical recesses 19a and 20a as second spherical guides having the optical reference point O as the center of the spherical surface.
are two guide sliders, upper and lower having
14a so that it can move forward and backward.

Reference numerals 21 and 22 are a first screw and a second screw for adjusting a back focus lens (hereinafter referred to as "BFL"), one end of each is inserted into and screwed into the guide slider 19, 20, and each other is screwed into the guide slider 19, 20. The end portions are inserted into and screwed into the upper and lower portions of the substrate 12. Note that these first screws 21 and second screws 22 are connected to, for example, C on the front and back sides of the substrate 12.
Movement in the axial direction is restricted by a ring a (only one shown).

Reference numeral 23 denotes a second holder for holding a lens, which has a through hole 23a in its center that opens on both end faces, and is provided in front of the first holder 11 so as to be movable forward and backward, and swingable. On one side edge of this second holder 23, the first
A second holding piece 24 facing the holding piece 17 is integrally provided, and spherical convex portions 24a, 25 as first spherical guides that fit into the spherical concave portions 19a, 20a are provided on both upper and lower edges.
Guide pieces 24 and 25 having a diameter a are integrally provided. Further, the second holder 23 is provided with annular grooves 23b and 23c extending around both opening peripheries of the through hole 23a. A lens assembly 26 having a plurality of lenses 26a to 26d is attached to the second holder 23.

Reference numeral 27 denotes a second O-ring as a sealing member, which is installed in the annular groove 23b of the annular grooves 23b and 23c, and is connected to the lens 26a and the second holder 2.
It is interposed between 3 and 3.

28 is a third screw for vertical angle adjustment;
It is inserted into the second holder 23 and the first holder 11, and a first nut 29 is screwed into the lens-side insertion end of both of these insertion ends. In addition, 30
is a spherical washer.

31 is a fourth screw for horizontal angle adjustment;
It is inserted through the first holding piece 17 and the second holding piece 24, and a second nut 32 is screwed into the lens-side insertion end of both of these insertion ends. Note that 33 is a spherical washer.

Reference numeral 34 denotes a bellows as a coupler, which is a cylindrical bellows made of a ferrous metal material such as stainless steel and has a biasing force in the axial direction, and is provided between the first holder 11 and the second holder 23. The CRT 16 is loaded with bullets and is configured to be able to change the tilt angle of the CRT 16. Annular bodies 35 and 36 as flanges having a plurality of mounting holes 35a and 36a arranged in parallel at intervals in the circumferential direction are welded to both ends of the bellows 34. The bellows 34 has the CRT 16
A liquid 37 for optically coupling the lens assembly 26 and the lens assembly 26 is sealed therein.

Reference numeral 38 denotes a third O-ring as a sealing member, and of the annular bodies 35 and 36, the annular body 35 on the CRT side
and the substrate 12 of the first holder 11,
And it is installed in the annular groove 12c.

A fourth O-ring 39 also serves as a sealing member, and is connected to the annular body 36 on the lens side and the second holder 23.
and is installed in the annular groove 23c.

[0026] In the figure, the symbols X1, X2 and Y1, Y
2 are the second screws adjusted by the third screw 28 and the fourth screw 31, respectively.
The adjustment direction of the holder 23 is shown.

In the projector configured as described above, the tilt angle of the CRT 16 is adjusted by moving the third screw 28 or the fourth screw 31 forward or backward.

That is, when the third screw 28 is advanced,
Each guide piece 24, 25 of the second holder 23 is located at the optical reference point O.
2 along the spherical recesses 19a and 20a with
Since the bellows 34 rotates in the direction indicated by 1, the bellows 34 partially contracts. At this time, the lens assembly 26 is attached to the second holder 23.
It swings in the same direction as the rotational direction of the lens and tilts counterclockwise (FIG. 1) with respect to the optical axis at the initial position.

Furthermore, when the third screw 28 is moved backward, the second
Since the guide pieces 24 and 25 of the holder 23 rotate along the spherical recesses 19a and 20a around the optical reference point O in the direction indicated by X2 in FIG. 2, the bellows 34 partially extends. At this time, the lens assembly 26 swings in the same direction as the rotation direction of the second holder 23, and the optical axis at the initial position is tilted clockwise (FIG. 1).

On the other hand, when the fourth screw 31 is advanced, the second
Since the guide pieces 24 and 25 of the holder 23 rotate along the spherical recesses 19a and 20a around the optical reference point O in the direction indicated by Y1 in FIG. 2, the bellows 34 partially contracts. At this time, the lens assembly 26 swings in the same direction as the rotation direction of the second holder 23, and the optical axis at the initial position is tilted clockwise (in plan view).

Furthermore, when the fourth screw 31 is retracted, the second
Since the guide pieces 24 and 25 of the holder 23 rotate along the spherical recesses 19a and 20a around the optical reference point O in the direction indicated by Y2 in FIG. 2, the bellows 34 partially extends. At this time, the lens assembly 26 swings in the same direction as the rotational direction of the second holder 23, and the optical axis at the initial position is tilted counterclockwise (in plan view).

Therefore, in this embodiment, since the second holder 23 rotates around the optical reference point O when adjusting the tilt angle of the CRT 16 due to a change in the projection system, the tilt angle of the CRT 16 cannot be adjusted. The optical reference point O does not change each time, and the tilt angle can be finely adjusted.

The axial dimension adjustment between the CRT 16 and the lens assembly 26 is performed as follows.

That is, the first screw 21 and the second screw 2
2, the lens assembly 26 moves along the guide grooves 13a, 14a via the guide sliders 19, 20.
Move in the direction approaching RT16. At this time, the entire bellows 34 contracts in the axial direction, and the dimension between the CRT 16 and the lens assembly 26 becomes narrower.

On the other hand, when the first screw 21 and the second screw 22 are moved backward, the lens assembly 26 is moved back to the guide slider 1.
9, 20 along the guide grooves 13a, 14a.
16. At this time, the entire bellows 34 extends in the axial direction, and the dimension between the CRT 16 and the lens assembly 26 becomes wider.

Furthermore, in this embodiment, since the amount of deformation of the coupler can be set to a large amount, CR
The tilt angle adjustment range of T16 can be expanded.

Furthermore, in this embodiment, the third O-ring 38 can improve the sealing between the first holder 11 and the annular body 35, and the fourth O-ring 39 can improve the sealing between the second holder 23 and the annular body 36. You can increase your sexuality.

Furthermore, in this embodiment, since the bellows 34 is made of a metal material such as stainless steel, the cooling effect of the liquid 37 can be enhanced.

In addition, in this embodiment, since the coupler is formed of a bellows having a biasing force in the axial direction, it is possible to prevent the bellows 34 from being bent due to gravity.

In this embodiment, the first spherical guide and the second spherical guide have spherical convex portions 24a and 25a, respectively.
Although the present invention is not limited to this, the first spherical guide and the second spherical guide may each have spherical concave portions 19a, 20a and spherical convex portions 24a, 25a. Even if there is, the same effect as the embodiment is achieved.

Further, in this embodiment, an example was shown in which the tilting angle of the CRT 16 is adjusted by imparting a rotational motion to the second holder 23, but the present invention
It goes without saying that the tilting angle of the CRT 16 can be adjusted even if rotational movement is applied to the CRT 16.

[0042]

As described above, the present invention includes a first holder that holds a projection tube, and a second holder that is swingably provided in front of the first holder and holds a lens. The second holder is equipped with a first spherical guide centered on the optical reference point, and the first holder is equipped with a second spherical guide that matches the first spherical guide, so that the projection tube can be tilted when changing the projection system. During angle adjustment, the first spherical guide or the second spherical guide rotates about the optical reference point.

Therefore, since the optical reference point does not change each time the tilt angle of the projection tube is adjusted, the tilt angle can be adjusted in detail, and the reliability in focus adjustment can be improved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing essential parts of a projector according to the present invention.

FIG. 2 is a partially sectional perspective view of a projector according to the present invention.

[Fig. 3] A perspective view showing a coupler in the present invention.

[Figure 4]
FIG. 2 is a plan view shown for explaining the outline of the projector.

FIG. 5 is a sectional view showing a conventional projector.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 11... First holder, 16... CRT, 19, 20... Guide slider, 19a, 20a... Spherical recess, 23... Second
holder, 24, 25... guide piece, 26... lens assembly,
O...Optical reference point.

Claims (1)

[Claims] Claim 1: A first holder that holds a projection tube; and a second holder that is swingably provided in front of the first holder and holds a lens; A projector characterized in that a first spherical guide is provided, and a second spherical guide matching the first spherical guide is provided in the first holder.