Hitachi, Ltd.

Yuzo Tamura

Yoshiaki Iwahara

Masanori Ogino

Shoji Kuroda

Akio Yamamoto

Masanori Oguino

Masutomi Ohta

Yukihiro Kobayashi

Hiroshi Kaiwa

A support member for supporting a plurality of vertically-arranged Fresnel sheets is fixedly mounted on a lower end portion of a reinforcing sheet. A hanging mechanism hangs the reinforcement sheet and the Fresnel sheets vertically adjustably. An elongated screen is constituted by a plurality of vertically-arranged unit screens, and the overall screen is constituted by a plurality of elongated screens arranged horizontally. A mechanism for preventing the relative displacement of the opposed edges of the elongated screens from each other in a direction perpendicular to the plane of the elongated screen is provided at an effective projection light-absent region where the light projected from projectors onto the screen is not hindered. A mechanism for limiting the absolute displacement of the elongated screens in a direction perpendicular to the plane of the elongated screen is provided at the right and left edges of the elongated screens and is disposed at the effective projection light-absent region. The limiting mechanism includes a plate member having a buckling load resistance, and pins connecting the opposite ends of the plate member respectively to the elongated screen and a fixed position in such a manner that the elongated screens are free to move vertically. A pillar member is used for fixing the end of the plate member, and a space between a support base supporting the unit projectors and the pillar members is used as a maintenance screen.

Multi-screen projector

Unit projectors whose number is n.times.m are arranged in n rows and m columns like a matrix. Unit screens whose number is n.times.m are arranged so that they as a whole form an enormous transmissive screen. Each unit screen is composed of the three layers of a front sheet on a Fresnel sheet on a re-inforcing sheet facing an observer. A front sheet is provided with the shape having a one-dimensional curvature which causes the peripheries of the front sheet and a re-inforcing sheet to be apart from each other when the center of the front sheet is brought in touch with that of the re-inforcing sheet in the unloaded state. Wires smaller in diameter than the pixel size are connected to the left and right sides of the front sheet, springs provide the wires with tension with support members as their support, and the force of the springs is thus provided by way of the wires for the front sheet so that the left and right sides of the front sheet are pressed on the re-inforcing sheet by way of the Fresnel sheet. The boundary part between the unit screens is reduced into a minimum.

A liquid crystal panel type projection display wherein exit light rays from at least one liquid crystal panel are projected onto a screen for display. Lenses are configured with respect to the liquid crystal panel and the screen so as to enable a large projection field angle.

Liquid crystal panel type projection display

A multi-screen projector composed of a plurality of unit module projectors piled up one upon another in the vertical direction. Each unit module projector includes a Fresnel lens sheet, lenticular sheet, and prism sheet interposed therebetween such that a light is incident to the Fresnel lens sheet and outputted from the lenticular sheet. The prism angle of the prism sheet of the unit module projector disposed at a higher position is set larger than that disposed at a lower position, and the main output light from the prism sheet is made at least parallel with the incident light direction or deflected downward relative to the incident light direction.

A rear projection apparatus is disclosed which is provided with at least two optical projection lens units. Two or more projected images are joined to form a single projected image on a screen. A light reflection preventing member is provided on a blocking plate for preventing the adjacent images from overlapping with each other. The reflection preventing member is used for preventing the light, projected onto the blocking plate, from being introduced into the screen, thereby preventing a degradation of contrast.

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Yokohama, Japan

Yuzo Tamura