Abstract: The present invention provides a cell that does not impair heat resistant safety and electrochemical characteristics such as a discharge characteristic, and enhances long-period reliability. In the cell of the present invention, a nonaqueous solvent has, among compounds represented by the following general formula (1), at least one solvent having a boiling point of 200° C. or higher, and has, among compounds represented by the following general formula (1), at least one solvent having a boiling point of lower than 200° C.; and the total volume ratio at 23° C. of the compounds represented by the following general formula (1) is 95 to 100 percent of the nonaqueous solvent, X—(O—C2H4)n-O—Y??(1) (where X and Y are independently an alkyl group (number of carbons: 1-4), and n is 1-5).

Abstract: The present invention provides a cell that does not impair heat resistant safety and electrochemical characteristics such as a discharge characteristic, and enhances long-period reliability. In the cell of the present invention, a nonaqueous solvent has, among compounds represented by the following general formula (1), at least one solvent having a boiling point of 200° C. or higher, and has, among compounds represented by the following general formula (1), at least one solvent having a boiling point of lower than 200° C.; and the total volume ratio at 23° C.

Abstract: The present invention provides a cell that does not impair heat resistant safety and electrochemical characteristics such as a discharge characteristic, and enhances long-period reliability. In the cell of the present invention, a nonaqueous solvent has, among compounds represented by the following general formula (1), at least one solvent having a boiling point of 200° C. or higher, and has, among compounds represented by the following general formula (1), at least one solvent having a boiling point of lower than 200° C.; and the total volume ratio at 23° C.

Abstract: A lithium cell has a positive electrode, a negative electrode having lithium, a separator interposed between the positive electrode and the negative electrode, and a non-aqueous electrolytic solution containing a solute and a non-aqueous solvent. The non-aqueous solvent has a main component of one or more than one compound represented by the following general formula (1): X—(O—C2H4)n-O—Y (where X and Y are independently a methyl group or an ethyl group, and n is 2 or 3). The main component is 90 to 100% in volume of the non-aqueous solvent. The separator has a melting point of higher than 150° C. The lithium cell with the above construction does not impair heat resistant safety and electrochemical characteristics such as discharging characteristics even in severe environments of high temperature, and enhances its long period reliability.

Abstract: An optical disc comprises; a substrate; grooves concentrically or helically formed on the substrate in each of which data is recorded; lands defined between the adjacent grooves; and prepits formed on the lands, wherein each of the prepits is disposed to be shifted from a center line of the land toward a groove to be paired without overlapping with adjacent tracks, whereby reducing cross-talk from adjacent tracks and improving the density of recorded data.

Abstract: An optical disc comprises; a substrate; grooves concentrically or helically formed on the substrate in each of which data is recorded; lands defined between the adjacent grooves; and prepits formed on the lands, wherein each of the prepits is disposed to be shifted from a center line of the land toward a groove to be paired without overlapping with adjacent tracks, whereby reducing cross-talk from adjacent tracks and improving the density of recorded data.

Abstract: An optical disk original recording is formed as follows: In a photo-resist layer forming step, a photo-resist layer is formed in such a manner that its thickness is much larger than the thickness which corresponds to a predetermined depth; and in a heating step, the photo-resist layer is heated at a temperature close to the melting point thereof, so that the surfaces of the recesses are fluidized to eliminate the rough surfaces, and the thickness of the photo-resist layer is decreased to a value which corresponds to the predetermined depth of the pits or grooves.

Abstract: An optical disc includes two transparent substrate layers each having a recording surface with a plurality of pits arranged concentrically or spirally. The plurality of pits represents information stored on the recording surface. Each transparent substrate layer has a thickness of 0.6.+-.0.03 mm. A reflecting layer is formed on each of the recording surfaces of the two transparent substrate layers. An inclining angle formed between a pit inner wall and a normal line of each transparent substrate layer is 20.degree.-55.degree., and pit depth is set to be .lambda./3.5N-.lambda./2.7N. .lambda. is defined as the wavelength of a laser beam incident the optical disc for reading the information recorded on the optical disc, and N is the index of refraction of each transparent substrate layer.

Abstract: A photo-resist layer of positive type, which is formed by a predetermined thickness on a disc substrate and which is exposed by a light beam modulated in accordance with record information to produce an optical record medium comprising the photo-resist layer and the disc substrate, is developed by the developing method. The developing method includes the steps of: firstly developing the exposed photo-resist layer by alkaline developing solution which has a normality of 0.17 to 0.

Abstract: An optical disk of the type including guide grooves is improved by regulating the width of the grooves, and thus the width of the adjacent land portion, in accordance with the type of information recorded at that part of the land.

Abstract: In an optical disk manufacturing method in which a first photo resist layer, an intermediate resin layer, and a second photo resist layer are formed on a substrate in the stated order, a resin solution which is unsoluble in organic solvent is applied to the first photo resist layer, heated, and hardened to form the intermediate resin layer. Thereby the use of a large, expensive device such as a vacuum deposition device or sputting device is eliminated.