Abstract: A plurality of structures each having a number of ridges and being formed in a long and thin plate shape or a long and thin film shape. The cross section of each of the ridges forms a portion of a substantial circle and a surface thereof is a practically specular surface. The ridges of each structure are parallel to each other and respective adjacent surfaces thereof correspond to each other in parallel and are spaced apart from each other at a predetermined distance. When light is incident on a point of a surface of one of the structures at an incident angle, in either its reflection or transmittance, the light is diffused in a circular conical plane whose vertex is the incident point and whose center axis is a line parallel to the ridges, by a diffraction effect caused by the arrayed ridges. The flux of reflected diffused light is spread in one lengthwise half of the circular conical plane and the flux of transmitted diffused light is spread in the other lengthwise half of the circular conical plane.

Abstract: Four light-transmitting mono filaments each having an almost circular cross section and surface substantially being mirror surface are arranged in a single layer and in parallel, and a flat yarn formed by fusing or melt-bonding adjacent mono filaments to each other and fixing them is twisted. Twisting is imparted over a full length of a light diffusing yarn continuously at a frequency of more than one time with a length five times as long as the width of the flat yarn. The twisting cyclically reverses the front and rear surfaces of the flat yarn along the longitudinal direction of the light diffusing yarn to continuously change the longitudinal-axis direction of each mono filament along the longitudinal direction of the light diffusing yarn.

Abstract: A lighting apparatus includes at least one rigid elongated cylindrical structure having a longitudinal axis, and a plurality of rigid plate-like structures fixed to the cylindrical structure such that each of the plate-like structures is perpendicular to the longitudinal axis. Also, at least one straight fluorescent tube is mounted to at least either the cylindrical structure or the plate-like structures.

Abstract: A light distribution controller for discharge lamps having improved lamp efficiency while maintaining a specific lighting posture. The controller includes a lighting source (1) in which electric discharge is caused between opposed electrodes (2, 4) to radiate light, a reflecting mirror (5) for reflecting a flux of light radiated from the light source (1) to control the light flux angle, and travel path changing mirror (7) for changing the travel path of the flux of light whose divergence is controlled by the reflecting mirror (5). The light source (1) is arranged such that the axial line connecting the electrodes (2, 4) of the light source (1) or a reference line used for another posture specification is substantially aligned with the center line of the flux of light controlled by the reflecting mirror (5). The path changing mirror (7) can change the direction in which the controlled flux of light travels to a desired direction with respect to the center line of the controlled flux of light.

Abstract: A light distribution control device including a substantially plate-like or film-like light diffusion structure which transmits or reflects light and at least one surface of which has a number of ridges arranged parallel to each other. The section of each ridge taken in a direction perpendicular to the longitudinal direction substantially constitutes a part of a circle, the surface of each ridge being smooth enough not to cause significant irregular diffusion of light. The ratio of diffraction light quantity to incidence light quantity is adjusted through selection of the angle of circumference and maximum diameter of the section of each ridge. The projection of diffusion distribution onto a plane perpendicular to both the longitudinal direction of the ridges and the surface of the structure is substantially symmetrical with respect to the normal at the point of incidence independently of the angle of incidence of the light.

Abstract: An area or a part which is shaded or does not receive a sufficient amount of light due to a structure or other objects is irradiated by light distribution control or luminous flux density control with diffusion, refraction, division and the like of light. Sunbeams are diffused by a transparent body disposed above two buildings, and the diffused light reaches an area or a part that has conventionally been shaded.