Nippon Electric Co., Ltd.

Nippon Telegraph and Telephone Public Corporation

Nobuo Nishida

Mitsuhito Sakaguchi

Atsufumi Ueki

Suehiro Miyazaki

Shinji Takahashi

Itsuo Matsubara

Masahiro Moriwaki

Relatively large hologram storage plates, e.g., those storing a large number of discrete entries such as character definitions for a large character set, comprise an array of mini-holograms arranged in different memory plate sections. A different photodiode array is associated with each hologram plate section (for efficiency, some elements of different diode arrays may be common). When the stored contents of any mini-hologram are interrogated by a coherent light beam, the stored information is derived via the associated photodiode array and converged (as by OR logic) to memory output terminals.

Large holographic memory with plural overlapping detector arrays

A multiplexed holographic recording system employs plural transparent positive pictures, each representing a different pictorial or video information content, which embody differing, unique pre-assigned spatial frequencies. A hologram is formed of the positive pictures, the reconstructed image from the hologram being identical in smoothed intensity distribution to a composite picture formed by superposition of the positive pictures. Spatial frequency filters are employed to remove, from the object beams transmitted through the positive pictures driving hologram formation, spatial frequency components assigned to other pictures. Accordingly, crosstalk between the multiplexed pictorial information is obviated.

Multiple recording system for video signals and optical images

Growing community of inventors

Tokyo, Japan

Nobuo Nishida