Abstract: In a method of analyzing a concentration of a target substance contained in a fluid using a quartz oscillator having a surface covered with a layer capable of absorbing the target substance, the temperature of the fluid and the quartz oscillator is controlled at substantially the same predetermined temperature selected according to the concentration of the target substance in said fluid, so that the analysis can be made with optimum sensitivity. A device for analyzing a concentration of a target substance contained in a fluid, includes a contacting chamber accommodating a quartz oscillator, a temperature controller, disposed in a feed passage for feeding the fluid into said contacting chamber, for adjusting a temperature of the fluid at a desired predetermined temperature; and a detector of a frequency of the quartz oscillator.

Abstract: In a transmission liquid crystal display apparatus, light rays emitted from a light source and reflected from a mirror are collimated by a collimator lens and incident in a liquid cell structure through a polarization layer. The light rays emerged from the structure are transmitted through an another polarization layer and diffused by a diffusion layer. The diffusion light rays pass through a filter layer to a viewer.

Abstract: A method and apparatus determines the thickness of a copper oxide coating of an object by measuring the quantity of light reflected from the object in at least two wavelength zones, and then determining a value for a relationship between those quantities, for example, the ratio or difference of those quantities. The value is then compared to a predetermined, regular correspondence between such values and copper oxide thicknesses to determine the object's copper oxide thickness.

Abstract: A color liquid crystal display device fitted with a liquid crystal panel having a pixel formed with a plurality of primary color pixel components combined so that a reference white is reproduced, each of the primary color pixel components further having a corresponding liquid crystal shutter; and a back light unit disposed in the rear of the liquid crystal panel and used to give light in such a manner as to have the light pass through the liquid crystal shutters. In the color liquid crystal display device, the transmission factors of the liquid crystal shutters corresponding to the primary color pixel components are set substantially equal and the reference white is reproduced on the liquid crystal panel by means of the transmission factors thus set. With this arrangement, it becomes possible to set high the luminance of the reference white, to equalize the gradation levels depending on the primary color and to simplify the configuration of its driving circuit.

Abstract: An lighting apparatus including a housing having an opening, a light source received in the housing and a light transmitting-cover fixed at the opening of the housing and through which light rays are projected from the light source. The light transmitting-cover includes a plate made of light transmitting-material and having a first surface and a second surface. Segment lens elements of the same size are arranged on the first and second surface of the plate and formed integrally with the plate. The segment lens elements on the first surface are positioned in face-to-face relation with the segment lens elements arranged on the second surface, thus forming a segment lens. The segment lens elements have a common optical axis and convex surfaces, respectively. The focal lengths defined by these convex surfaces are equal.

Abstract: In a rear projection screen, a pair of light-refracting plates oppose each other. A plurality of first convex lens elements are arranged parallel to each other on one surface of the light-reacting plate, and a plurality of second convex lens elements are arranged parallel to each other on the other surface of the light-refracting plates. Similarly, a plurality of first convex lens elements are arranged parallel to each other on one surface of the light-refracting plate, and a plurality of second convex lens elements are arranged parallel to each other on the other surface of the light-refracting plate. Each pair of opposed first and second convex lens elements is located along a common optical axis thereof. A convex surface of each first convex lens element is located at a focal plane of the corresponding second convex lens element. A convex surface of each second convex lens element is located on a focal plane of the corresponding first convex lens element.

Abstract: A rear projection apparatus for producing an optical image on a surface of a rear transmitting screen in which a convex lens array is formed on both surfaces of the screen, each convex lens formed on one surface of the screen having a corresponding convex lens formed on the other surface of the screen with a common optical axis, the focal point of each convex lens formed on one surface of the screen being on the surface of the each convex lens formed on the to other surface of the screen.

Abstract: An optical refractor comprises a plate made of transparent material and having a first surface and a second surface. Segment lens elements of the same size are arranged on the first and second surface of the plate and formed integrally with the plate. The segment lens elements on the first surface are positioned in face-to-face relation with the segment lens elements arranged on the second surface, thus forming pairs of segment lens element. The segment lens elements have a common optical axis and convex surfaces, respectively. The focal lengths defined by these convex surfaces are equal. The focal point of one of the segment lens elements lies on the convex surface of the other segment lens element, and that of the other segment lens element lies on the convex surface of the first segment lens element.