Abstract: A head-up display device comprises an image generator, a beam combiner having a light receiving plane tilted laterally for receiving a light from the image generator and diffracting the light, and a compensator arranged between the image generator and the beam combiner for receiving the light from the image generator by a light receiving plane thereof and directing the light to the beam combiner to correct an aberration created by the beam combiner. The compensator is arranged such that a normal line extending through a center of the light receiving plane thereof and a normal line extending through a center of the light receiving plane of the beam combiner are in a common plane.

Abstract: A method of observing information includes the steps of converting a radiation beam into a visible harmonic beam conforming to the information and observing the information by the harmonic beam. An apparatus for observing information therethrough includes a source for producing a radiation beam conforming to the information, and a converter for converting the radiation beam into a visible harmonic beam, with the information being observed with the aid of the harmonic beam. In addition, a head-up display apparatus includes a source for producing a radiation beam conforming to information to be displayed, a converter for converting the radiation beam into a visible harmonic beam, and a beam combiner for receiving the harmonic beam and directing it in a predetermined direction to effect the display of the information by the harmonic beam.

Abstract: A display apparatus comprises a display, a first diffraction grating for diffracting light from the display, and a second diffraction grating for diffracting diffracted light from the first diffraction grating, so that a half-width of the first diffraction grating is set to be larger than that of the second diffraction grating.

Abstract: A polymer of vinyl-biphenyl derivative comprising recurring units of the formula: ##STR1## wherein X is Cl or Br; a is an integer of 0-4; Y is --CH.sub.3, --OH, --OR, --SR, --SOR, --SO.sub.2 R, --SeR, --SeOR, --SeO.sub.2 R, --TeR, --TeOR, or --TeO.sub.2 R, wherein R is alkyl capable of having a substituent, aryl capable of having a substituent, or ##STR2## and Z is --CH.sub.2 --, --C(CH.sub.3).sub.2 --, --O--, --S--, --SO--, --SeO.sub.2 --, --Te--, --TeO--, or --TeO.sub.2 --; b and c are integers giving the sum of 1 to 5, and c is 1 or more. The polymer has a high refractive index and an excellent transparency. Further, the polymer can have a variable refractive index at a constant Abbe's number.

Abstract: a display apparatus comprises, a display unit, a first diffraction grating for diffracting the light from the display unit, and a second diffraction grating for diffracting the diffracted light from the first diffraction grating, the apparatus being constructed in such a manner that the optical path length between the display unit and the first diffraction grating is shorter than that between the first and second diffraction gratings.

Abstract: A photosensitive material is provided which comprises (i) a substrate comprising a crosslinked polymer having a transmittance of 90% or more in a wavelength region of from 400 to 700 nm and a refractive index of 1.55 or more, and (ii) a sensitive material layer provided on the substrate and mainly composed of a vinylcarbazole polymer. A hologram member employing the photosensitive material is also provided.

Abstract: A process for producing a gel fiber comprises a step (N) of spinning a solution containing at least one polymer having at least one monomer unit as a constituent component for a gel to solidify the solution into a fiber, and step (M) of effecting crosslinking of the fiber to form a gel which can be swelled or shrunk reversibly by a thermal action in the presence of a liquid.

Abstract: A biocatalyst such as an enzyme or microbe is immobilized in a polymer gel having a phase transition temperature such that it is capable of reversibly swelling and shrinking by a change in temperature. By lowering the temperature, the polymer gel is caused to swell and a biocatalyst is absorbed therein and by raising the temperature, the polymer gel is caused to shrink and immobilize the biocatalyst. The biocatalyst may then be released by cooling the polymer to cause it to swell. Only a portion of the polymer gel may be subjected to temperature change to immobilize the biocatalyst only in a desired portion.

Abstract: An optical element comprises a gel layer exhibiting a light scattering property when heated and exhibiting transparency when cooled, and the gel layer is sandwiched between a transparent substrate and a transparent protective plate.

Abstract: A hologram member and a method of preparing a volume type phase hologram film includes forming a volume type phase hologram in a polymer film formed on a substrate and comprised of a vinylcarbazole polymer, separating the polymer film from the substrate and allowing the hologram to be supported on the substrate so that the surface of the hologram not having contacted the substrate, contacts the substrate.

Abstract: A hologram member is provided which comprises a substrate, and a film in which a volume type phase hologram is recorded. The film is provided peelably on the substrate. The substrate preferably has a light transmittance of 30% or more at a wavelength of from 450 to 800 nm. The film may comprise a vinylcarbazole.

Abstract: An optical element comprised a pair of plates between which an optical modulation liquid layer is sandwiched, the optical modulation liquid layer exhibiting a light scattering property caused by suspension of fine particle polymer when not heated and exhibiting transparency caused by dissolution of fine particle polymer when heated, the change of such light scattering property to transparency being reversible.

Abstract: An variable-focus optical device capable of changing the focal length with excellent responsiveness and reproducibility during repetitive deformation, comprises: an elastomeric member having prescribed viscoelastic characteristics, and an aperture member having an aperture adapted for causing projection or sinking of the elastomeric member therethrough or thereat.

Abstract: An optical modulating method is provided which comprises heating a heat-sensitive medium comprising a polymeric substance and a liquid with a heat-generating resistor adjacent to the medium, thereby modulating the light incident on the medium at the heated region. The liquid may be heated to the critical solution temperature or higher of the constituent polymeric substance.

Abstract: A method of preparing a volume type phase hologram film comprises forming a volume type phase hologram in a polymer film formed on a substrate and comprises of a polymer of vinylcarbazoles, and separating the polymer film from the substrate. Preferably, the polymer film is separated from the substrate in a liquid inert to the hologram.

Abstract: An optical element comprises a pair of plates between which an optical modulation liquid layer is sandwiched, the optical modulation liquid layer exhibiting a light scattering property caused by suspension of fine particle polymer when heated and exhibiting transparency caused by dissolution of fine particle polymer when not heated, the change of such light scattering property to transparency being reversible.

Abstract: A display device is provided which comprises a medium includng a biochemical luminous reaction system and an electrode which controls electrochemically the concentration of at least one of reactants participating in said reaction system in a cell. The luminous reaction system may include an enzyme, and the electrode may be modified with a polymer.

Abstract: An optical recording medium is provided which comprises an optical recording layer provided on a support, said optical recording layer containing a compound modifiable under light irradiation and gelled polymer.