Abstract: A transmission screen has a refraction total reflection Fresnel lens plate 10C, a stray light eliminating plate 20, and an image display plate 30. The stray light eliminating plate 20 has a condensing lens array 21 and black stripes 23. The array 21 has unit lenses arranged at an incident plane of the transparent substrate 22 in a periodic structure in an up-and down direction. The black stripes 23 has transparent sections 201 placed near condensing light points of the unit lens and opaque sections 200 around the condensing light points of the unit lenses. The sections 201 and 200 are alternately arranged at the outgoing plane of the transmission substrate 22 in a periodic structure in an up-and-down direction. The image display plate has lenticular lenses 31 in which unit lenses are arranged in a periodic structure in a horizontal direction at an incident plane of the transmission substrate 32 of a scattering characteristic capable of scattering light fluxes.

Abstract: A rear projection screen of the type which allows a projected light beam incident thereon to pass therethrough to a viewer side includes a Fresnel lens sheet, and a lenticular lens plate opposed to the Fresnel lens sheet. The Fresnel lens sheet is in the form of a thin sheet made of a resin, and converts the projected light beam incident thereon into substantially collimated light to direct the substantially collimated light outwardly toward the viewer side. The lenticular lens plate refracts the projected light beam incident thereon horizontally or vertically.

Abstract: An image display device comprises an optical imaging arrangement for providing image information to illumination light and for transmitting the light as an optical image signal; a display for receiving the optical image signal and for displaying an image based on the image information; and a projecting optical arrangement including a reflecting part having a reflecting surface for reflecting the optical image signal, and a refracting optical part having a refracting surface for projecting the optical image signal onto the reflecting part. At least one of the reflecting surface and the refracting surface is aspherical.

Abstract: A Fresnel lens has a plurality of pitch areas in which a plurality of hybrid type prism portions are arranged. Each hybrid type prism portion has a refraction type prism portion and a total reflection type prism portion. In the refraction type prism portion, a ray of incident light Li1 of an incident angle “a” is refracted twice and goes out as a ray of outgoing light Lo1 of an outgoing angle “f”. In the total reflection type prism portion, a ray of incident light Li2 of the incident angle “a” is refracted, totally reflected and refracted in that order and goes out as a ray of outgoing light Lo2 parallel to the ray of outgoing light Lo1.

Abstract: A Fresnel lens has a plurality of pitch areas in which a plurality of hybrid type prism portions are arranged. Each hybrid type prism portion has a refraction type prism portion and a total reflection type prism portion. In the refraction type prism portion, a ray of incident light Li1 of an incident angle “an” is refracted twice and goes out as a ray of outgoing light Lo1 of an outgoing angle “f”. In the total reflection type prism portion, a ray of incident light Li2 of the incident angle “a” is refracted, totally reflected and refracted in that order and goes out as a ray of outgoing light Lo2 parallel to the ray of outgoing light Lo1.

Abstract: Lengths of both sides of each end plane of a light-intensity distribution uniformizing element receiving a light flux and having an F-number of 1 are set to ½ of those of a reflecting surface of a reflecting optical-spatial modulator element, position information of uniformed light fluxes output from the light-intensity distribution uniformizing element is Fourier-transformed into diverging angle information indicated by incident light fluxes output from a first group of lenses, a relay deformed diaphragm intercepts an interference component of each incident light flux, which is expected to interfere with an outgoing light flux, to produce asymmetric light fluxes, the asymmetric light fluxes are incident on the reflecting optical-spatial modulator element, a projection lens deformed diaphragm removes stray light from outgoing light fluxes output from the reflecting optical-spatial modulator element, and an image is displayed according to the outgoing light fluxes.

Abstract: A lamp (1) has a deformed lamp reflector (1b) and a lamp front glass (1c). The deformed lamp reflector (1b) is made by deforming an ellipsoidal of revolution of a conventional lamp reflector (10b) to an aspherical reflection surface rotationally symmetric with respect to an optical axis Z. The lamp front glass (1c) is obtained by deforming at least one of incident plane and outgoing plane of a conventional lamp front glass (101c) to an aspherical lens surface rotationally symmetric with respect to the optical axis Z. A light flux emitted from the center point (Pf) of the illuminant (1a) is reflected by the deformed lamp reflector (1b), and outputted with a uniform density through the entire of the outgoing plane of the lamp front lens (1c) so that the light flux is condensed at the focus point.

Abstract: A refracting optical lens 15 is provided to project light from transmitting means onto a convex mirror 16 to correct for pincushion distortion of the convex mirror 16.

Abstract: A lamp has a deformed lamp reflector (1b) and a lamp front glass (1c). The deformed lamp reflector (1b) is formed by deforming a paraboloid of revolution of a conventional lamp reflector (101b) to an aspherical reflection surface which is rotationally symmetric symmetrical with respect to an optical axis Z. The lamp front glass (1c) is obtained by deforming the incident plane of a conventional lamp front glass (101c) to an aspherical lens surface rotationally symmetric with respect to the optical axis Z. A light flux irradiated radiated from the center point Pf of the light source of an illuminant (1a) is reflected by the deformed lamp reflector (1b), and is output through the lens (1c) as a parallel light flux having a circular cross section equal in area to the outgoing plane of the lens (1c).

Abstract: In an image display which reproduces a color image by using lights color-separated into four or more colors through color filters, the objects of the invention are to effectively utilize the energy of light from a light source and to reduce the effect that a slight shift of the spectral transmittance characteristics of the color filters exerts on the spectral distributions of the lights after color separated.

Abstract: Lengths of both sides of each end plane of a light-intensity distribution uniformizing element receiving a light flux of an F-number of 1 are set to ½ of those of a reflecting surface of a reflection type optical-spatial modulator element, position information of uniformed light fluxes output from the light-intensity distribution uniformizing element is Fourier-transformed into diverging angle information indicated by incident light fluxes output from a first group of lenses, a relay deformed diaphragm intercepts an interference component of each incident light flux, which is expected to interfere with an outgoing light flux, to produce asymmetric light fluxes, the asymmetric light fluxes are incident on the reflection type optical-spatial modulator element, a projection lens deformed diaphragm removes stray light from outgoing light fluxes output from the reflection type optical-spatial modulator element, and an image is displayed according to the outgoing light fluxes.

Abstract: A refracting optical lens 15 is provided to project light from transmitting means onto a convex mirror 16 to correct for pincushion distortion of the convex mirror 16.

Abstract: A screen unit includes a semipermeable screen sheet sandwiched between a first transparent sheet and a second transparent sheet. The semipermeable screen sheet transmits and reflects a projected image in a constant percentage. The first transparent sheet such as an acrylic sheet wider than the semipermeable screen sheet. The second transparent sheet is the same as the first transparent sheet.

Abstract: A Fresnel lens has a pitch including a hybrid prism comprising a refraction prism unit (3A) for emitting an incident light (li1) of an incident angle (a) as an outgoing light (lo1) of an outgoing angle (f) by two refractions, and a total reflection prism unit (4A) for emitting an incident light (li2) of an incident angle (a) as an outgoing light (lo2) parallel to the outgoing light (lo1) by a refraction, a total reflection, and a refraction.

Abstract: The invention relates to an image display device displaying color image and has its object to display image having a small contrast and excellent visibility to the viewer in an image display device particularly used under environment where external light exists.

Abstract: There is disclosed a display device using a color wheel having a color filter Cw, in addition to normal color filters corresponding to the three primary colors. The filter Cw has almost flat spectral transmission characteristics. Brightness information included in a color image signal is quantized with (n+m) bits. Information corresponding to the lower-order n bits is displayed by light transmitted through the filter Cw. Information corresponding to the upper-order n bits is displayed by light transmitted through the normal color filters. Only brightness information to which the human eye is visually sensitive is reproduced by the filter Cw having a lower transmissivity. This can eliminate a lack of the number of gray levels due to a constraint on the minimum switching speed of a light valve. Furthermore, the brightness little deteriorates.

Abstract: A refracting optical lens 15 is provided to project light from transmitting means onto a convex mirror 16 to correct for pincushion distortion of the convex mirror 16.