Abstract: A video display apparatus has a dot matrix of LEDs mounted on an LED matrix board, and a unitary reflecting member made of metal such as aluminum or the like mounted on the LED matrix board. The reflecting member has slanted reflecting surfaces disposed vertically one on each side of each of the LEDs for reflecting light emitted from the LEDs with narrow vertical directivity. The video display apparatus can provide a wide angle of view in the horizontal direction, and a narrow angle of view in the vertical direction for preventing light from being scattered in the vertical direction to maintain a desired level of luminosity.

Abstract: The present invention makes it possible to improve color shift, shading and view angles, to prevent external light absorption and reflection, to enhance external light contrast, to eliminate reflection of external images that appear on a light transmission screen's face plate, and to provide distinct pictures free of the adverse effects of dust. The light transmission screen disclosed by the present invention comprises a Fresnel lens sheet, a transparent lenticular lens sheet arranged on the Fresnel lens sheet's radiant light side and a front diffusion panel formed of a thin diffusion layer and a transparent layer and arranged on the lenticular lens sheet's light radiant side.

Abstract: An image processing apparatus designates image area on the original. A shifting device shifts the image area by predetermined amount. An outputting device outputs the image data corresponding to the image area and the image data corresponding to the shifted image area.

Abstract: A method for mass-producing eccentric Fresnel lens sheets comprising the steps of: preparing a number of concentric Fresnel lens sheets; dividing the concentric Fresnel lens sheets into a first set and a second set each including a plurality of Fresnel lens sheets; cutting out a plurality of first sheets each corresponding to one portion of the eccentric Fresnel lens sheet from each of the Fresnel lens sheets of the first set; cutting out a plurality of second sheets each corresponding to the other portion of the eccentric Fresnel lens sheet from each of the Fresnel lens sheets of the second set; and bonding each of the first sheets and each of the second sheets in such a manner that patterns on the first sheet and the second sheet are continuous to prepare a plurality of eccentric Fresnel lens sheet. The second set can include a third set and a fourth set and a plurality of third sheets are cut out from the third set and a plurality of fourth sheets are cut out from the fourth set.

Abstract: A video display apparatus has a dot matrix of LEDs mounted on an LED matrix board, and a unitary reflecting member made of metal such as aluminum or the like mounted on the LED matrix board. The reflecting member has slanted reflecting surfaces disposed vertically one on each side of each of the LEDs for reflecting light emitted from the LEDs with narrow vertical directivity. The video display apparatus can provide a wide angle of view in the horizontal direction, and a narrow angle of view in the vertical direction for preventing light from being scattered in the vertical direction to maintain a desired level of luminosity.

Abstract: Collaborative work on an interactive system is facilitated by accurately capturing and displaying information on an interactive system, wherein multiple persons may work together for supplying and receiving information with a single large area display. A large area electronic writing system is provided which employs a large area display screen, an image projection system, and an image receiving system including a light emitting pen. The display screen is designed with the imaging surface in front of the substrate, with a thin abrasion resistant layer protecting the imaging surface from the pen tip. The screen is held together with dowel pins pressed through the layers, and is curved to provide pressure for holding the layers together and mechanical rigidity against flexure during writing. The imaging surface disperses light from both the projection system and the light pen.

Abstract: The invention relates to optical elements, particularly retro-reflecting, retro-imaging and optical transmission inversion elements to relay a true scale equal conjugate image of a scene. Hitherto, the image had a resolution limit set by the pitch and/or packing density of micro-optical elements to reflect or transmit ray bundles impinging on them, the number of elements within the viewing zone determining the lateral and hence depth resolution in any given direction. The object of the invention is to reduce the effect of micro-screen texture in a relatively inexpensive manner, that provides real-time systems and which can be used with fast moving objects. This objective is met by an optical element comprising a retro-reflecting or auto-collimating transmission screen (9) having one or more lenses (6,10) and an associated means (8,11) of displacing wavelengths to different degrees and whereby to spread a reflected or transmitted image into a spectral streak.

Abstract: Disclosed is a front projection display screen formed from a multiplicity of optical cells juxtaposed to define a surface. Each of the cells comprises a directional filter and light converging optics. The directional filter, which covers substantially all of the face of the optical cell, is adapted to pass light from the direction of the projector and to absorb light from other directions except at a small, transparent return aperture. The light converging optics are adapted to focus the substantially parallel light from the projector at the return aperture part of the directional filter and to spread it into a large solid angle. The combination provides an image of improved visual contrast by absorbing background light and returning image light to viewers.

Abstract: A display apparatus comprises a projecting device for projecting an image, with the projecting device having a projection optical system having a limited pupil diameter and screen device arranged at a position where an image is substantially projected by the projecting device. The screen device has at least two sheets in each of which a number of prisms extending like a straight line or a curve are formed on the surface on the side opposite to the projecting device.

Abstract: A viewgraph projector having a light above the transparency receiver and jecting downward through the transparency is provided. The projected image is received below the transparency by a condenser lens and further transmitted by a flexible fiber-optic cable. A projecting lens is provided at the output end of the fiber-optic cable for projecting the images to a screen. Structurally associated with the projecting lens is a device or means which enables removably affixing the projecting lens relative to a suitable support in a conference room environment, which device may for example constitute a clip, hooking means, clamp, or weights. This enables a subset of the aforesaid elements comprising the light source, transparency receiver, and condenser lens to be located independently of the projecting lens, as for example, to locations where they do not obstruct the audience's field of view or where backscattered illumination from the light source does not annoy the audience.