JP2000067788A - Image projecting mechanism and image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To project a good image even on a curved screen by using liquid in which a design value of index of refraction in the case projecting an image onto a flat screen is different by a specified value of more under the condition of the same wave length and temperature in an optical connection part. SOLUTION: Liquid 9 is filled in the inside space 8 of an optical connection part 4. As the liquid 9, a glycol mixture solution having an index of refraction of about 1.44 usually in the conditions of e-rays and 25 deg.C is used in the case projecting an image onto a flat screen, but in projection onto a curved screen, good focus on the whole screen can not be obtained. Therefore, liquid having an index of refraction different 0.01 or more from that of the glycol mixture solution is used. More specifically, a radius of curvature of a concave lens constituted with the liquid 9 filled in the inside space 8 of the optical connection part 4 is about 63 mm, silicone oil having dimethyl polysiloxane structure having an index of refraction of 1.40 is used as the liquid 9, and a dome-shaped screen having a radius of about 3 m is used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image projection mechanism and an image display device for projecting an excellent image on a curved screen.

[0002]

2. Description of the Related Art In recent years, an image projected on an image display unit such as a cathode ray tube (CRT) is enlarged and projected on a screen by a projection lens system disposed in front of an image display surface of the image display unit. Projection mechanism, a video display device using a so-called projector, for example, for consumer use, a large-sized screen can be easily enjoyed, a so-called rear projection television that projects an image from behind the screen, and a high-end consumer use such as a commercial or home theater. For example, a high-definition so-called front projector system that projects an image from the front of a screen is widely used.

A projector used for an image display device such as the above-mentioned rear type projection television or front projector system is generally designed to project an image on a flat screen, and naturally, an optical system such as a projection lens system is used. The components are also designed so that the best projected image quality can be obtained when projecting onto a flat screen.
Therefore, the optical component can be manufactured relatively inexpensively by the effect of mass production.

[0004]

By the way, in order to provide a viewer with an image of a wider field of view and to enhance the sense of realism, the above-mentioned image display device forms a part of a spherical surface or a part of a cylinder. There is a need for a projector that displays an image projected by a projector on a curved screen.

[0005] Distortion of an image when the image is projected on a curved screen by a projector for projection onto a flat screen can be corrected by electrically adjusting the raster shape.

[0006] However, since the projector itself is originally intended to project an image on a flat screen, the optical imaging condition is still such that the best results can be obtained when projecting an image on a flat screen. It was difficult to obtain good focus over the entire curved screen.

In order to solve this problem, a special projection optical system may be designed so that a good image quality can be obtained on a specific curved surface. However, an optical system used for a general flat screen projector can be used. Optical components such as lenses used for projectors for special-purpose curved screens that require special designs for each curved surface are naturally produced in small quantities, and the projectors are expensive because mass production effects cannot be expected. There was a problem that would be.

Further, a video display device using the above-mentioned expensive projector becomes expensive and its commercial value is impaired. Furthermore, as described above, in order to correspond to curved screens of various shapes, it is necessary to create dedicated optical components, and there are various types of optical components, and these management problems arise. Become.

Accordingly, it is an object of the present invention to provide a video projection mechanism and a video display device capable of projecting a good video even on a curved screen using optical components for a general flat screen. Things.

[0010]

In order to solve the above-mentioned problems, the present invention provides an image projection mechanism, comprising: an optical coupling portion having a design value of a refractive index for projecting an image on a flat screen having the same wavelength and the same temperature; Under the conditions, a liquid different by 0.01 or more is used.

Therefore, it is possible to obtain a good projected image corresponding to a curved screen.

Further, the image display device of the present invention uses a liquid having a design value of a refractive index which differs by 0.01 or more under the same wavelength and the same temperature condition when projecting an image on a flat screen for the optical coupling portion. Has a curved surface formed as a concave surface when viewed from the viewer side.

Therefore, it is possible to project a good projected image corresponding to a curved screen, and it is possible to obtain an image display device having a wider field of view and displaying a realistic image.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the video projection mechanism of the present invention will be described with reference to the accompanying drawings.

First, basic matters of the video projection mechanism and the video display device of the present invention will be described.

The image projection mechanism used in the image projection mechanism of the present invention and the image display apparatus of the present invention can be used for a curved screen having an appropriate curvature by using an optical system originally designed to project an image on a flat screen. This is to make it possible to project an image in which focus, various aberrations, and the like have been well corrected.

That is, the image projection mechanism has an image display section and a projection lens system for projecting an image displayed on the image display section onto a screen. The image display section and the projection lens system are internally provided. Liquids are combined by a sealed optical coupling part, and a liquid having a design value of a refractive index different by 0.01 or more under the same wavelength and the same temperature condition when projecting an image on a flat screen is used for the optical coupling part. It was made.

Further, the image display device projects an image on a screen having a concave surface as viewed from the viewer side by using the image projection mechanism.

The principle of using the above liquid as a liquid having a refractive index different from that of a flat screen in accordance with the curvature of a curved screen on which an image is projected will be described.

That is, in order to discuss the third-order aberration, the radius of the i-th surface which is the i-th surface from the screen of the lens system composed of k surfaces is “R _i ”, and the refractive index of the medium in front of the surface is “R _i ”. the "N _i", and the refractive index of the rear of the medium of the surface and "N _'i', the Petzval sum is a parameter related to the curvature of the image surface" P "can be determined by the following formula .

[0021]

(Equation 1)

Further, when the refractive index of the medium behind the final surface k from the screen side is changed from “N ′ _k ” to “N ″ _k ”,
The Petzval sum “P _new ” is as follows.

[0023]

(Equation 2)

Furthermore, when the radius of the curved image plane and "R _scrn", when the _{1 / R scrn = N "k} / P ne w become. Planar projection lens, because the P = 0, the formula R _scrn can be obtained from the following equation.

[0025]

(Equation 3)

As described above, the image plane (= screen) can be curved to a predetermined curvature by changing the refractive index of the liquid filled in the optical coupling portion.

Also, in a projection optical system in which a strong concave lens (= liquid filled in the internal space of the optical coupling portion) is arranged near the light emitting portion on the rearmost surface from the screen side, the concave lens functions as a so-called field flattener. Further, aberrations other than the curvature of field are substantially corrected in the optical system in front of it. Therefore, even if the refractive index of the concave lens, that is, the liquid, is changed, it is possible to keep the quality of the image projected on the curved screen small.

Next, specific embodiments of the present invention will be described.

FIGS. 1 and 2 show a first embodiment of an image projection mechanism according to the present invention, and an image projection mechanism (hereinafter, referred to as a "projector") 1 for projecting an image on a curved screen. As shown in FIG. 1, a substantially cylindrical lens barrel 2 and a cathode ray tube (hereinafter, referred to as a video display unit)
It is called "CRT". 3.) The lens barrel 2 and CRT 3
And a projection lens system 5 composed of a plurality of lenses arranged in the lens barrel 2 and the like.

As shown in FIG. 1, the projection lens system 5 includes a plurality of first lenses L1, second lenses L2, third lenses L3, It has an eight-lens configuration including a lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, and an eighth lens L8.

The optical coupling portion 4 connected to the lens barrel 2 and the CRT 3 by appropriate means has a substantially cylindrical main portion 6 as a whole, and has an opening on the lens barrel 2 side and a CR.
The opening on the T3 side is closed by the eighth lens L8 of the projection lens system 5 and the image display surface 7 of the CRT 3 to define an internal space 8, and the internal space 8 is filled with a liquid 9.

When an image is projected on a flat screen, a glycol mixed solution having a refractive index of about 1.44 is generally used as the liquid 9 under the condition of e-line and 25 ° C. In the present embodiment, a liquid having a refractive index different from the refractive index by 0.01 or more is used. This is because if the projection lens system 5 originally designed for projection on a flat screen is used as it is for projection on a curved screen, it is difficult to obtain good focus on the entire screen.

Thus, the projector 1 is used for the projector system 10 as shown in FIG.

Specifically, the concave lens constituted by the liquid 9 filled in the internal space 8 of the optical coupling section 4 has a radius of curvature of 63 mm, and the liquid 9 has a dimethylpolyxylosane structure having a refractive index of 1.40. A dome-shaped screen 11 having a radius of 3 m is used as the projection screen using colorless and transparent silicone oil. Therefore,
The R _scrn is 3003 mm, and a good focus on the screen 11 can be obtained.

The projector system 10, which is an image display device, has projector devices 12, 12, 12 each including a projector 1, 1, 1, and the three projectors 12, 12, 12,
An image is projected onto the screen 11 with a field of view of 80 degrees, so that an observer located in the cabin 13 can be provided with a realistic image close to reality.

FIGS. 3 and 4 show a video projection mechanism according to a second embodiment of the present invention.
Are designed for projecting an image on a flat screen, except for a part described later. As shown in FIG. 3, a lens barrel 21 having a substantially cylindrical shape, a CRT 22 and the lens barrel 21 are formed. Optical coupling part (coupler) 23 and lens barrel 2 which are disposed between
Projection lens system 2 consisting of a plurality of lenses arranged in 1
4 and so on.

As shown in FIG. 3, the projection lens system 24 includes a plurality of first lenses L1, second lenses L2, third lenses L3, and It has four lenses of four lenses L4.

The optical coupling portion 23 connected to the lens barrel 21 and the CRT 22 by appropriate means has a substantially cylindrical main part 25 as a whole, and has an opening on the lens barrel 21 side and a CRT 22 side. Each of the apertures is a projection lens system 2
The inner space 27 is defined by being closed by the fourth fourth lens L4 and the image display surface 26 of the CRT 22, and the inner space 27 is filled with a liquid.

When an image is projected on a flat screen, a glycol mixed solution having a refractive index of about 1.44 is generally used as the liquid 28 under the condition of e-line and 25 ° C. In the present embodiment, a liquid having a refractive index different from the refractive index by 0.01 or more is used.

Thus, as shown in FIG. 4, the projector 20 is used in a video display device, for example, a rear projection (rear) projector system 29 used in a game center or the like.

Specifically, the internal space 2 of the optical coupling section 23
7 has a radius of curvature of 41 mm of the concave lens constituted by the liquid 28 and the liquid 28 has a refractive index of 1.5.
Using a colorless and transparent silicone oil having a methylphenylpolyxylosane structure of 0 as a projection screen,
The screen 30 having a radius of 840 mm which is curved on the viewer side.
Is used. Therefore, the R _scrn is −83
8 mm, so that a good focus can be obtained for the curved screen 30.

The projector system 29 has a projector device 31 including the projectors 20, 20, and 20, and projects an image from behind a screen 30, as shown in FIG. Because of the curved shape, the field of view when viewed at the same position is loved at the corners as compared with a flat screen, so that a more realistic image can be enjoyed.

It should be noted that the specific shapes and structures of the respective parts shown in each of the above-described embodiments are merely examples of the embodiment of the present invention.
These should not be construed as limiting the technical scope of the present invention.

[0044]

As is evident from the above description, the image projection mechanism of the present invention is designed so that the design value of the refractive index when projecting an image on a flat screen is adjusted to the optical coupling portion under the same wavelength and the same temperature condition. Since different liquids of 0.01 or more are used, a good projection image corresponding to a curved screen can be obtained.

Further, the image display apparatus of the present invention uses a liquid having a design value of the refractive index which differs by 0.01 or more under the same wavelength and the same temperature condition when projecting an image on a flat screen, in the optical coupling section. Has a curved surface formed as a concave surface when viewed from the viewer side, so that it is possible to project a good projection image corresponding to a curved screen, having a wider field of view and a sense of presence. An image display device that displays an image can be obtained.

[Brief description of the drawings]

FIG. 1 shows a video projection mechanism and a video display device according to a first embodiment of the present invention together with FIG. 2, and is a cross-sectional view showing the video projection mechanism.

FIG. 2 is a diagram schematically showing a video display device.

3 shows a second embodiment of the video projection mechanism and the video display device of the present invention, together with FIG. 4, and is a sectional view showing the video projection mechanism. FIG.

FIG. 4 is a diagram schematically showing a video display device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Video projection mechanism, 3 ... Video display part, 4 ... Optical coupling part,
5 Projection lens system 9 Liquid 10 Image display 1
DESCRIPTION OF SYMBOLS 1 ... Screen, 20 ... Image projection mechanism, 22 ... Image display part, 23 ... Optical coupling part, 24 ... Projection lens system, 28 ... Liquid, 29 ... Image display device, 30 ... Screen

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) G02B 13/16 G02B 13/16 F term (Reference) 2H087 KA07 LA01 PA04 PA08 PA18 PB05 PB09 QA02 QA05 QA14 QA15 QA21 QA22 QA25 QA26 QA38 QA41 QA45 UA09 5C036 EE03 EF01 EF07 EF09 EF11 EG42 EG43 EG50 EH11 5C058 AA01 BA23 BA27 EA12 EA33 EA43 EA45

Claims (4)

[Claims] An image display unit; and a projection lens system that projects an image displayed on the image display unit onto a screen.
In an image projection mechanism in which the image display unit and the projection lens system are coupled by an optical coupling unit in which a liquid is sealed, a design of a refractive index when projecting an image on a flat screen to the optical coupling unit An image projection mechanism characterized in that liquids having values different by 0.01 or more under the same wavelength and the same temperature conditions are used. 2. A design value of a refractive index when projecting an image on a liquid flat screen used for an optical coupling portion is e.
At 1.42 to 1.44 at 25 ° C.
A dimethylpolyxylosane-based or methylphenylpolyxylosane-based silicon oil or a mixture thereof, which is adjusted to have a refractive index of 1.38 to 1.41 or 1.45 to 1.51, is used as a liquid for an optical coupling portion. The video projection mechanism according to claim 1, wherein the video projection mechanism is used for: 3. An image display unit, comprising: a projection lens system for projecting an image displayed on the image display unit onto a screen;
The image display unit and the projection lens system have an image projection mechanism coupled by an optical coupling unit in which a liquid is sealed, and an image display configured to project an image on a screen by the image projection mechanism. In the apparatus, for the optical coupling portion, a liquid having a design value of a refractive index different from the designed value of the refractive index when projecting an image on a flat screen by 0.01 or more under the same wavelength and the same temperature condition is used. An image display device having a curved surface formed as a concave surface when viewed from a side. 4. A design value of a refractive index when projecting an image on a liquid flat screen used for an optical coupling portion is e.
At 1.42 to 1.44 at 25 ° C.
A dimethylpolyxylosane-based or methylphenylpolyxylosane-based silicon oil or a mixture thereof, which is adjusted to have a refractive index of 1.38 to 1.41 or 1.45 to 1.51, is used as a liquid for an optical coupling portion. The video display device according to claim 3, wherein the video display device is used for: