Disclosed is an inexpensive, bright, compact, lightweight, high-definition projection-type display device that has a comparatively simple structure but satisfies demands for oblique projection, uniform illumination, a deep focal depth, and magnified projection over a short distance. The display device comprises a light source (1a); an illumination portion (1) consisting of a group of collection angle control components, which comprises at least one optical surface (1c) for receiving a principal light ray generated from the imaginary center of the light source (1a) and controlling the solid collection angle thereof, and a group of luminous flux control components, which comprises at least two optical surfaces which are an optical surface (1d) mainly having a spatial distribution control function over the principal light ray in a virtual plane provided perpendicular to the direction of propagation of the principal light ray emitted from the group of [luminous flux] control components and an optical surface (1e) for receiving a principal light ray from the surface and mainly having a function of controlling the direction thereof; an image creation portion (2) for creating an original image by selectively reflecting or transmitting luminous flux from the illumination portion (1) and for ensuring that the cone angle of the luminous flux contributing to the image creation does not greatly change before and after; and an imaging portion (3) for collecting the luminous flux emitted from the image creation portion and creating a secondary image on a screen.
A bright reflection type projection optical system is used for projecting onto a screen under magnification a luminous flux carrying image information from a light valve driven by an image signal, while favorably correcting aberration. The reflection type projection optical system comprises, successively from the enlargement side, a first mirror having a positive power, a second mirror having a negative power, and a third mirror having a positive power.
A three-dimensional image display apparatus emphasizes display of a particular portion using the volume rendering method, where a volume image constructed by aligning a plurality of tomograms is shaded and projected on a predetermined projection plane to produce a 3D image. A volume rendering method is used where, in an algorithm for shading, virtual light beams are radiated from a virtual light source set outside the volume image, and pixel values on the projection plane are calculated based on reflectivity and density gradient of light beams at the respective pixels on the projection plane. At a luminescence ratio allocating area, a luminescence ratio is allocated for amplifying light beams entering pixels representing a particular object to be emphasized. The thus-allocated luminescence ratio is added as a parameter of the shading calculation in the volume rendering method and is used for calculation of pixel values on the projection plane.
Image display apparatus comprising a projector, at least one primary modulator (4,6,8) for modulating light, an auxiliary modulator (36) for modulating the light modulated by the primary modulator, and an optical device (32) for relaying the light modulated by the primary modulator to the auxiliary modulator (36), the optical device (32) comprising a concave mirror and at least one refractive element.
A projection optical system is provided to guide a beam from an image display panel onto a screen surface inclined relative to a reference axis, and to form image information on the screen surface. The projection optical system has a reflecting optical system which has a plurality of rotation-asymmetrical reflecting surfaces having curvatures, and in which the beam from the image display panel is reflected by the plurality of rotation-asymmetrical reflecting surfaces and is guided onto the screen surfaces of the reflecting optical system or between the reflecting optical system and the image display panel. The stop is set so as to be imaged at a negative magnification by an optical member disposed more adjacent to the screen than the stop position.
An integrator type illumination optical system has a first lens array and a second lens array. The first lens array includes left, center, and right column groups. The thickness of the lens cells of the center column group is thinner than that of the lens cells in other column groups, and the thickness of the lens cells in the left and right column groups increases from the inner column outward gradually. The lens cells in the left and right column groups are shaped to converge incident light away from the optical axis of the integrator type illumination optical system, and the lens cells in the center column group are shaped to converge incident light toward the optical axis of the integrator type illumination optical system.
