Nippondenso Co., Ltd.

Tetsuya Kato

Toshiki Saburi

Yasuhiro Mizutani

Minoru Ohta

Naoyuki Kawazoe

Hirokatsu Mukai

Teiyuu Kimura

Kazumasa Kurokawa

Satoshi Koike

Hiroyuki Tarumi

Masayuki Goto

Tomonori Ishikawa

Hiroyuki Tatebayashi

A plurality of hologram elements are simultaneously exposed to a constructing light while they are arranged in the form of a stack, so that the incident beam can be uniform within the exposure area. The plurality of hologram elements should be transparent to the constructing light.

Process for making holograms and holography device

A hologram element includes an optically transparent base plate having first and second opposite surfaces. A film of a diffraction grating is provided on the first surface of the base plate. A nonreflective member is provided on the second surface of the base plate via a dipping process. The nonreflective member includes one of a film including SiO.sub.2 particles and a film of MgF.sub.2. It is preferable that the SiO.sub.2 particles have diameters of 10-150 nm. The diffraction grating film includes, for example, one of a gelatine film, a photopolymer film, and a photoresist film. The base plate includes, for example, a flexible resin film. It is preferable that the flexible resin film is made of a material selected from the group consisting of amorphous polyolefine, polycarbonate (PC), polymethyl methacrylate (PMMA), and perfluoroalkoxypolyethylene (PFA).

Hologram and method of fabricating

A hologram comprising a diffraction grating film with an interference fringe recorded thereon, a substrate provided on one side of said diffraction grating film, and cover plates provided on the surfaces of the aforesaid diffraction grating film by use of an adhesive, wherein the lateral face portion of the aforesaid hologram is covered with a water repellent layer, or a hologram comprising a diffraction grating film with an interference fringe recorded thereon and a substrate provided on one side of said diffraction grating film, the surface of the aforesaid diffraction grating film being covered with an adhesive, wherein the aforesaid adhesive contains an epoxy resin mixture consisting of an alicyclic epoxy and novolak type epoxy and an alicyclic acid anhydride type curing agent, a chief ingredient composed of an aromatic epoxy resin(s) and a curing agent comprising a mixture of an alicyclic amine and an aliphatic amine, or a chief ingredient composed of an aromatic epoxy resin(s) and a curing agent comprising a mixture of an alicyclic amine and an aromatic amine.

Hologram

Disclosed is a method for producing an optical member having excellent optical characteristics. An optical member is composed of a support plate and an optical sheet stuck on said plate via an optical adhesive. The optical adhesive is made sticky after it is coated, including ultraviolet-curing adhesives, epoxy adhesives and their mixtures. To produce the optical member, the optical sheet is formed on the surface of a fixed substrate via a transfer film. The optical adhesive is coated onto the optical sheet, the adhesive is made sticky on the sheet, the fixed substrate is peeled off, the sheet is stuck onto the support plate using the adhesive, and the adhesive is cured.

Method for producing optical member

A hologram includes an optically transparent base plate having first and second opposite surfaces. A hologram element is provided on the first surface of the base plate, and has a predetermined holographic pattern. An optically transparent member has first and second opposite surfaces. The first surface of the member faces the hologram element. An arrangement serves to prevent light, which successively passes through the transparent base plate, the hologram element, and the member and is then reflected at a boundary between the second surface of the member and an atmosphere, from travelling back to the hologram element.

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Okazaki, Japan

Tetsuya Kato