Abstract: This invention relates to a foamed resin sheet containing closed-cells which have a specific average diameter and a specific volume ratio. The foamed resin sheet of this invention is excellent in light reflectance or light transmittance to visible light and is also excellent in light diffusing capability, and in particular it is suitable as a light reflective plate or light diffusing plate to be incorporated and used in a direct backlight unit for a large-screen liquid crystal display or a 15- to 39-inch large-screen liquid crystal television set. The industrial effect that this invention produces is remarkable.

Abstract: This invention relates to a foamed resin sheet containing closed-cells which have a specific average diameter and a specific volume ratio. The foamed resin sheet of this invention is excellent in light reflectance or light transmittance to visible light and is also excellent in light diffusing capability, and in particular it is suitable as a light reflective plate or light diffusing plate to be incorporated and used in a direct backlight unit for a large-screen liquid crystal display or a 15- to 39-inch large-screen liquid crystal television set. The industrial effect that this invention produces is remarkable.

Abstract: There is provided a resin sheet having a thickness of 1 to 5 mm, having recesses formed on one surface thereof, the recess having a multi-sided pyramid shape, a truncated multi-sided pyramid shape, a conical shape, a truncated conical shape or a severed sphere shape, having an angle ? which satisfies 10°???40° or 50°???80° or 40°<??43° or 47°??<50° when the angle ? is formed by a side face or the generatrix of the recess and a plane having the opening of the recess thereon, and satisfying at least one of the following conditions (1) and (2). (1) The above recesses form a number of row groups, wherein each row group which constitute the number of row groups comprises a number of rows adjacent to each other, each row comprises the recesses arranged in a line, and each row group is adjacent to other row groups via areas free of the recesses. (2) Severed-sphere-shaped projections are formed on the surface opposite to the surface having the above recesses formed thereon.

Abstract: A metal film is deposited on a photoresist layer having information-dependent pits, and a first film of low surface energy is deposited on the metal film to thereby provide a master for making a stamper blank. A layer of radiation curing resin is deposited on the first film of low surface energy, and then a transparent plate of acrylic resin is placed on the layer of radiation curing resin, which is hardened by exposure to radiation such as ultraviolet radiation through the transparent plate. The transparent plate and the hardened layer are separated as a unitary stamper blank from the master. A second film of low surface energy is then deposited on the stamper blank to form a stamper. The first and second films of low surface energy are made of polymerized octafluorobutane and serve to allow the stamper blank and information storage discs to be released clear of the master and stamper, respectively.