RU2326418C2 - Projection optic system of home theater objective with internal compensation of projective screen distortions - Google Patents

Abstract

FIELD: optic instrumentation.

SUBSTANCE: device contains the assisting and main cascade providing during joint action the absence of outlet image projective distortions on the inclined screen. The assisting cascade provides the linear magnification β₁=β_Σ/β₀ and forms the intermediate image on the inclines. The main cascade of the projection objective process the linear magnification β₀ in such a way that projective distortions are absent on home theater screen.

EFFECT: distortions image elimination on the home theater screen; increasing of the image quality on the screen multipixel board.

1 dwg

Description

The invention relates to the field of optical instrumentation and can be used in the design of optical systems (lenses) of a projection television ("home theater").

Known optical systems for projection television lenses with a multipixel panel, which contain several series-mounted components made in the form of single or glued lenses (see US patent application No. 2004257539 [1] and Japanese application No. 2000066098 [2]).

The closest analogue to the invention is the optical system of a projection television lens described in Japanese Patent Application No. 2002357768 [3], which comprises a reflective multipixel panel sequentially arranged along the optical axis, the first lens system with positive optical power, which is a system whose optical axis is tilted in relation to the multipixel panel, the second lens system with negative optical power, offset relative to the optical axis, and the screen.

The disadvantage of all these known optical systems with good image quality is the presence of its promising distortion due to the large tilt of the screen, necessary to reduce the depth of the box of the projection TV.

The problem to which the invention is directed is to eliminate promising distortions when forming an image on an inclined screen of the Home Cinema and, thus, to further improve the image quality of the multipixel panel on the screen.

The technical result is achieved by the fact that in the optical system of the Home Cinema, which contains the information frame of the input image (multipixel panel, LCD or any other input information frame of the image) sequentially located along the rays, the projection lens and the screen of the Home Cinema, on which the output image of the information frame is formed with the desired increase in β _Σ, projection lens structurally comprises the primary and secondary stages, the characteristics of which, together with their provide the lack of perspective distortion of the output image on an inclined screen. The auxiliary cascade of the projection lens provides a linear increase of β ₁ = β _Σ / β ₀ and creates an intermediate image of the reflecting multipixel panel on an inclined plane having an axial offset -a and an angle of inclination α relative to the front main plane of the main stage. The main cascade of the projection lens works with a linear increase of β ₀ so that the conditions for the absence of projective distortions on the home theater screen are satisfied

where a 'is the axial distance of the screen plane from the rear main plane of the main cascade of the projection lens;

α 'is the angle of the home theater screen relative to the rear main plane of the main cascade of the projection lens.

The invention is illustrated in the drawing.

The drawing shows the optical system of the Home Theater. The optical system of the Home Cinema contains the input information frame 1 of the image sequentially located along the optical axis (for example, a reflective multi-pixel panel), a projection lens including an auxiliary stage 2 and a main stage 3, as well as a screen 4 of the Home Cinema. The optical axis of the auxiliary stage 2 of the projection lens is offset from the center of the multipixel panel and thus the auxiliary stage forms an intermediate image of the panel on an inclined plane, providing an increase in β ₁ = β _Σ / β ₀ . Then, the main cascade 2 of the projection lens transfers the intermediate inclined image of the multipixel panel to the screen 4 of the Home Theater, ensuring that the condition for the absence of projective distortions on the screen is satisfied. In this case, a predetermined increase in the projection lens β _{Σ is} also provided.

Claims (1)

The projection optical system of the Home Cinema lens, containing the input image information frame (multipixel panel, LCD, or any other input image information frame) located along the rays, the projection lens and the Home Cinema screen, on which the output image of the information frame with the required increase in β _{Σ is formed} , characterized in that, in order to eliminate perspective distortions in the formation of the output image, on a strongly tilted screen of the Home Theater roektsionny lens structurally comprises auxiliary and main stages, the characteristics of which in their working together provide no perspective distortion of the output image on the inclined screen; the auxiliary cascade of the projection lens is designed to provide a linear increase in β ₁ = β _Σ / β ₀ and create an intermediate image on an inclined plane having an axial offset α and an angle of inclination α relative to the front main plane of the main stage, and the main cascade of the projection lens works with by a linear increase in β ₀ so that the conditions for the absence of projective distortions on the home theater screen are satisfied β ₀ = a ′ / a; a ctg (α) -a 'ctg (α') = 0, where a 'is the axial distance of the screen plane from the rear main plane of the main cascade of the projection lens; α 'is the angle of the home theater screen relative to the rear main plane of the main cascade of the projection lens.