Abstract: A metal V-belt comprising an endless metal ring member 14 and a plurality of metal element members 10 supported along said metal ring member wherein the clearance between a slot portion S of the metal element members 10 and the endless metal ring member 14 is set larger than the clearance in the thickness direction of the belt between the concave and convex portions of a coupling portion 5 used for linking disposed on the front and rear surfaces of the metal element members 10. This controls damage to the metal ring member caused by contact between the metal ring member outermost periphery of the metal V-belt used in, for example, an infinite variable-speed drive and the metal element members.

Abstract: A belt for a continuously variable transmission in which an aggregate of metal rings formed by laminating a plurality of pieces of endless metal rings support a plurality of metal blocks. When the ratio .xi. of the coefficient of friction is set to be 2.0>.xi.>0.65, the amount of change in the tension on the metal ring of the innermost position decreases correspondingly. In particular, when the ratio .xi. of the coefficient of friction is set to be 1.0, resulting in the coefficient of friction .mu..sub.s between a ring and a block being equal to the coefficient of friction .mu..sub.SS between a ring and a ring, the amount of change in the tension on all metal rings become uniform, and each metal ring shares an amount of change in the tension which is 8% of the entire amount. This makes it possible to decrease the amount of change in the tension on the metal ring of the innermost position and, hence, to increase the durability of the aggregate of metal rings as a whole.

Abstract: A background lighting apparatus includes a light entering edge surface around substantially the entire periphery of a highly specular transparent plate wherein light beams enter from peripheral light sources and travel toward the central portion of the plate and are dispersed and diffused by a diffusion system formed relative to the transparent plate. Uniformity of luminance provided from the background lighting apparatus is enhanced as a whole by increasing the incident quality of the input light beams into the transparent plate while easing the incident directivity of the light beams on the transparent plate with the overall substantial enhancement of luminance produced from the apparatus.

Abstract: A background lighting apparatus includes a light entering edge surface around substantially the entire periphery of a highly internally reflecting transparent plate wherein light beams enter from peripheral light sources and travel toward the central portion of the plate and are dispersed and diffused by a diffusion system formed relative to the transparent plate. Uniformity of luminance provided from the background lighting apparatus is enhanced as a whole by increasing the incident quality of the input light beams into the transparent plate while easing the incident directivity of the light beams on the transparent plate with the overall substantial enhancement of luminance produced from the apparatus.