Abstract: 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.

Abstract: A heads-up display unit provided with a display device serving as display image forming means which displays a display image. A hologram serves as a reflecting means, and reflects the display light emitted from the display device, causing reflection of the display image on the interior surface of a vehicle's windshield. A display image is formed outside the windshield towards the front of the vehicle. A concave mirror having a different focal length in different directions is recorded in the hologram serving as a reflecting means so as to offset distortion of the display image caused by curvatures of the windshield. This construction makes it possible to cause the windshield to display a display image free from distortion.

Abstract: 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).

Abstract: 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 compris

Abstract: 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.

Abstract: 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.

Abstract: A gas component detecting element using particles of metal oxide. The particles are prepared and calcined, and then subjected to a treatment which enlarges a specific surface area thereof. Catalyst particles are supported on the surface of these particles, and then the particles are sintered. The gas component detecting element is formed from these particles. A detector formed in this way can be used for a long period of time without any change in characteristics.

Abstract: Disclosed is a method for producing a gas component detecting element for detectors which comprises a sintered body of particles of a metal oxide wich changes in electrical resistance depending on relative atmosphere of combustible components in an exhaust gas, catalyst particles being supported on the surface of particles of the metal oxide, the method comprising the following steps:preparing particles of the metal oxide,calcining the particles of the metal oxide,subjecting the calcined particles to a treatment for enlarging specific surface area of the calcined particles,supporting catalyst particles on the surface of the particles subjected to the enlargement treatment, andsintering the particles which support the catalyst particles.The detector which has the above-mentioned gas component detecting element is also disclosed.

Abstract: A high frequency filter for an electric instrument including a casing of metallic conductive material, an internal electric circuit element arranged within the casing, and a connector mounted on a peripheral wall of the casing for connecting the internal electric circuit element to an external electric circuit. The high frequency filter comprises an insulation substance layer arranged between the connector and a connection terminal of the circuit element, the insulation substance layer being made of a dielectric material whose dielectric constant decreases or increases in accordance with increase or decrease of wireless frequency applied thereto, and a pair of conductive layers formed on opposite surfaces of the insulation substance layer, one of the conductive layers being connected at one end thereof to the connector and at the other end thereof to the connection terminal of the circuit element, and the other conductive layer being connected to a portion of the casing.

Abstract: A high frequency wave absorbing ceramics can be used, for example, as an EMI preventive filter for interrupting high frequency waves intruding into electronic circuits. The high frequency wave absorbing ceramics are composed of a ternary composition comprising from 55 to 85 mol % of lead iron niobate Pb(Fe.sub.1/2 Nb.sub.1/2)O.sub.3, from 10 to 40 mol % of lead iron tungstate Pb(Fe.sub.2/3 W.sub.1/3)O.sub.3 and not more than 20 mol % of lead nickel tantalate Pb(Ni.sub.1/3 Ta.sub.2/3)O.sub.3 based on the total 100 mol % of a composition composed of lead iron niobate Pb(Fe.sub.1/2 Nb.sub.1/2)O.sub.3, lead iron tungstate Pb(Fe.sub.2/3 W.sub.1/3)O.sub.3 and lead nickel tantalate Pb(Ni.sub.1/3 Ta.sub.2/3)O.sub.3.

Abstract: A high frequency wave absorbing ceramics can be used, for example, as an EMI preventive filter for interrupting high frequency waves intruding into electronic circuits. The high frequency wave absorbing ceramics are composed of a ternary composition comprising from 50 to 80 mol % of lead iron niobate Pb(Fe.sub.1/2 Nb.sub.1/2)O.sub.3, from 10 to 40 mol % of lead iron tungstate Pb(Fe.sub.2/3 W.sub.1/3)O.sub.3 and not more than 40 mol % of lead iron tantalate Pb(Fe.sub.1/2 Ta.sub.1/2)O.sub.3 based on the total 100 mol % of a composition composed of lead iron niobate Pb(Fe.sub.1/2 Nb.sub.1/2)O.sub.3, lead iron tungstate Pb(Fe.sub.2/3 W.sub.1/3)O.sub.3 and lead iron tantalate Pb(Fe.sub.1/2 Ta.sub.1/2)O.sub.3.

Abstract: A high frequency wave absorbing ceramics can be used, for example, as an EMI preventive filter for interrupting high frequency wave intruding into electronic circuits. The high frequency wave absorbing ceramics are composed of a ternary composition comprising from 50 to 82.5 mol % of lead iron niobate Pb(Fe1/2Nb1/2)O.sub.3, from 17.5 to 40 mol % of lead iron tungstate Pb(Fe2/3W1/3)O.sub.3 and not more than 25 mole % of lead cobalt niobate Pb(Co1/3Nb2/3)O.sub.3 based on the total 100 mol % of a composition composed of lead iron niobate Pb(Fe1/2Nb1/2)O.sub.3, lead iron tungstate Pb(Fe2/3W1/3)O.sub.3 and lead cobalt niobate Pb(Co1/3Nb2/3)O.sub.3.

Abstract: A high frequency filter assembly for an electric instrument including an internal electric circuit element arranged within a casing of metallic conductive material, and a connector mounted on a peripheral wall of the casing for connecting an external electric circuit to the internal electric circuit element. The filter assembly comprises at least a pair of overlapped insulation thin plates to be arranged between the connector and a connection terminal of the circuit element, and an earth electrode strip disposed between the insulation thin plates and being connected to a portion of the casing.

Abstract: A high frequency filter in combination with an internal electronic circuit element of the flat-plate type, such as a hybrid integrated circuit element contained within a casing, includes an electrode member arranged on a circuit board within the casing to be grounded, an insulation substance layer, integrally formed on the electrode member and being made of a dielectric material whose dielectric constant decreases or increases in accordance with an increase or a decrease of wireless frequency applied thereto, and an electrode strip integrally formed on the insulation substance layer for connection to an external electric circuit. The internal electronic circuit element is integrally provided on either the electrode member or the insulation substance layer and connected to the electrode strip, and the electrode member is mounted on the circuit board to carry the electronic circuit element in place.

Abstract: A high frequency wave absorbing ceramics can be used, for example, as an EMI preventive filter for interrupting high frequency waves intruding into electronic circuits. The high frequency wave absorbing ceramics has a composition expressed by the chemical formula Pb{Fe.sub.1/2 Nb.sub.(1/2-x) Ta.sub.x }O.sub.3 where 0.1<x<0.35. The high frequency wave absorbing ceramics may be composed of a composition comprising from 30 to 80 mol % of lead iron niobate Pb(Fe.sub.1/2 Ta.sub.1/2)O.sub.3 based on the total 100 mol % of a Pb(Fe.sub.1/2 Nb.sub.1/2)O.sub.3 and from 20 to 70 mol % of lead iron tantalate composition composed of lead iron niobate Pb(Fe.sub.1/2 Nb.sub.1/2)O.sub.3 and lead iron tantalate Pb(Fe.sub.1/2 Ta.sub.1/2)O.sub.3.