Abstract: It is provided an optical head device which includes: a light source; an objective lens, configured to converge light emitted from the light source to an information recording surface of an optical disk; a beam splitter, configured to deflect returned light reflected by the optical disk into an optical path which is different from an optical path of the light emitted from the light source; a photo detector, configured to detect the returned light deflected by the beam splitter; and a depolarizing element, disposed on an optical path between the beam splitter and the photo detector, and configured to cause the returned light to transmit through while reducing a degree of polarization of the returned light.

Abstract: The present invention provides a wavelength-selective diffraction element, configured such that light having a plurality of wavelengths are incident thereon as incident light, which is provided with: a transparent substrate; a concavo-convex part, formed on the transparent substrate such that concave portions and convex portions are cyclically extended in one direction, and comprised of a first material which is optically isotropic; and a filling part, filling at least the concave portions and comprised of a second material which is optically isotropic. The first material and the second material have no absorbance with respect to the wavelengths of the incident light. The first material and the second material have an identical refractive index with respect to light having a first wavelength which is at least one of the wavelengths of the incident light.

Abstract: A method includes determining a first time by a first determining system. The method also includes determining a second time and a spatial position of a terminal receiving the second time, by a second determining system which is different from and independent of the first determining system. The terminal stores, in combination, the first time determined by the first determining system and the second time and the position determined by the second determining system, at each time of determining the spatial position of the terminal, in such a manner that the first time, the second time and the position are arranged in a row when they are outputted, wherein the first and second times are independent of each other.

Abstract: A GPS positioning system that has: at least one mobile station to measure a positional coordinate by receiving radio wave from a satellite; a plurality of fixed stations that have predetermined positional coordinates and receive radio wave from the satellite; and arithmetic processing means, which is connected with at least one mobile station and a plurality of fixed stations via communication, and that transmits correction data suitable for the mobile station to the mobile station based on positioning data transmitted from the mobile station.

Abstract: A GPS positioning system comprises a fixed station and a mobile station. The mobile station has: positional positioning means; imaging means; direction detecting means; and arithmetic processing means. The positional positioning means measures positional coordinates by receiving radio weve from a satellite. The imaging means is arranged in a predetermined position for the GPS positional positioning means. The direction detecting means detects a photographing direction during photographig by the imaging means. The arithmetic processing means forms landscape data in which imaging data that is an output from the imaging means is associated with orientation data that is an output from the direction detecting means.

Abstract: A GPS positioning system has: at least one mobile station to measure a positional coordinate by receiving radio wave from a satellite; a plurality of fixed stations that have predetermined positional coordinates and receive radio wave from the satellite; and arithmetic processing means, which is connected with at least one mobile station and a plurality of the fixed stations by communication, that selects an appropriate fixed station based on positioning data transmitted from at least one mobile station, and transmits reference positioning data of the fixed station selected to the mobile station.

Abstract: A GPS positioning system that has: at least one mobile station to measure a positional coordinate by receiving radio wave from a satellite; a plurality of fixed stations that have predetermined positional coordinates and receive radio wave from the satellite; and arithmetic processing means, which is connected with at least one mobile station and a plurality of fixed stations via communication, and that transmits correction data suitable for the mobile station to the mobile station based on positioning data transmitted from the mobile station.

Abstract: A GPS positioning system comprises a fixed station and a mobile station. The mobile station has: positional positioning means; imaging means; direction detecting means; and arithmetic processing means. The positional positioning means measures positional coordinates by receiving radio wave from a satellite. The imaging means is arranged in a predetermined position for the GPS positional positioning means. The direction detecting means detects a photographing direction during photographing by the imaging means. The arithmetic processing means forms landscape data in which imaging data that is an output from the imaging means is associated with orientation data that is an output from the direction detecting means.

Abstract: Two independent determining systems are used, wherein time or a point of time is determined by one determining system and the spatial position is determined by the other determining system, and wherein the time or the point of time and the position thus determined by the determining systems are stored in a terminal. A position determining apparatus comprises a GPS antenna for receiving the radio wave from a GPS satellite and a GPS receiver for receiving the data from the GPS antenna to determine the position, wherein the GPS receiver includes a processing unit, and thereby the processing unit processes the position coordinate data by the GPS position determination and the time data in another independent time system by correlating them with each other (FIG. 1).