Abstract: A surface light source device (20) includes a light guide plate (30), an optical sheet (60) and a light source (24). The optical sheet has unit prisms projecting toward the light guide plate and arranged in a first direction. The unit prism is composed of a first prism surface (71) facing the first direction, and a second prism surface (72) facing the other side of the first direction. The second prism surface (72) includes element surfaces (73) of different inclining angles. An inclining angle (?t) of each element surface, a length (Wt) of each element surface along the first direction and a length (Wb2) of the second prism surface (72) along the first direction satisfy predetermined conditions.

Abstract: A method for producing a medium-molecular weight polyalkylene oxide having a viscosity-average molecular weight of from 100,000 to 2,500,000, including heat-treating a polyalkylene oxide having a viscosity-average molecular weight of 3,000,000 or more at a temperature of from 30° to 70° C. in an aliphatic hydrocarbon solvent having a dissolved oxygen concentration of 0.5 mg/L or more, in the presence of a radical initiator in an amount of from 0.001 to 1 part by mass, based on 100 parts by mass of the polyalkylene oxide, and thereafter adding an antioxidant to a mixture in an amount of from 0.001 to 5 parts by mass, based on 100 parts by mass of the polyalkylene oxide to remove the solvent. According to the method of the present invention, a medium-molecular weight polyalkylene oxide having a viscosity-average molecular weight of from 100,000 to 2,500,000 which has excellent storage stability can be industrially obtained without subjecting to a gamma-ray irradiation treatment.

Abstract: A method for producing a medium-molecular weight polyalkylene oxide having a viscosity-average molecular weight of from 100,000 to 2,500,000, including heat-treating a polyalkylene oxide having a viscosity-average molecular weight of 3,000,000 or more at a temperature of from 30° to 70° C. in an aliphatic hydrocarbon solvent having a dissolved oxygen concentration of 0.5 mg/L or more, in the presence of a radical initiator in an amount of from 0.001 to 1 part by mass, based on 100 parts by mass of the polyalkylene oxide, and thereafter adding an antioxidant to a mixture in an amount of from 0.001 to 5 parts by mass, based on 100 parts by mass of the polyalkylene oxide to remove the solvent. According to the method of the present invention, a medium-molecular weight polyalkylene oxide having a viscosity-average molecular weight of from 100,000 to 2,500,000 which has excellent storage stability can be industrially obtained without subjecting to a gamma-ray irradiation treatment.

Abstract: The present invention provides a display device which can ensure a large viewing angle while maintaining high light source energy use efficiency. The display device 10, which outputs light emitted from a light source 25 to an observer side in a form of an image, comprises: a light guide plate 21 which has a light output face, a back face, and a side face positioned between the light output face and the back face; a light source 25 which emits light to the side face of the light guide plate; an optical sheet 30 disposed on the observer side of the light guide plate; a liquid crystal panel 15 disposed on the observer side of the optical sheet; and a device 40 for enlarging a view disposed on the observer side of the liquid crystal panel.

Abstract: A light guide plate shaped substantially like a plate includes a light incident surface, a light exit surface and a reflective surface, which is opposite to the light exit surface, configured to reflect light toward the light exit surface. A plurality of optical units is arranged along the reflective surface in a direction orthogonal to the light incident surface. Each optical unit is shaped substantially like a quadratic prism that is convex toward the reflective surface and has a top surface and two slopes being formed opposite to each other with respect to the top surface. A dimension of the top surface is constant in a direction of arrangement of the optical units and an interval between adjacent optical units becomes greater as the adjacent optical units lie further away from the light incident surface in the direction of arrangement of the optical units.

Abstract: The present invention provides a display device which can ensure a large viewing angle while maintaining high light source energy use efficiency. The display device 10, which outputs light emitted from a light source 25 to an observer side in a form of an image, comprises: a light guide plate 21 which has a light output face, a back face, and a side face positioned between the light output face and the back face; a light source 25 which emits light to the side face of the light guide plate; an optical sheet 30 disposed on the observer side of the light guide plate; a liquid crystal panel 15 disposed on the observer side of the optical sheet; and a device 40 for enlarging a view disposed on the observer side of the liquid crystal panel.

Abstract: A light guide plate shaped substantially like a plate includes a light incident surface, a light exit surface and a reflective surface, which is opposite to the light exit surface, configured to reflect light toward the light exit surface. A plurality of optical units is arranged along the reflective surface in a direction orthogonal to the light incident surface. Each optical unit is shaped substantially like a quadratic prism that is convex toward the reflective surface and has a top surface and two slopes being formed opposite to each other with respect to the top surface. A dimension of the top surface is constant in a direction of arrangement of the optical units and an interval between adjacent optical units becomes greater as the adjacent optical units lie further away from the light incident surface in the direction of arrangement of the optical units.

Abstract: A stator for a motor includes a stator core, an insulator, and coils. The stator core includes an annular portion and teeth, which extend radially from the annular portion. The stator core is divided into core segments in the circumferential direction. Each core segment has an arcuate portion and one of the teeth, which extends from the arcuate portion. The insulator insulates each coil wound around one of the teeth from the stator core. The insulator includes coupling portions at positions corresponding to the circumferential ends of the arcuate portions. Each coupling portion couples the adjacent core segments to be rotatable relative to each other. The insulator facilitates manufacture of the stator.

Abstract: A stator for a motor includes a stator core, an insulator, and coils. The stator core includes an annular portion and teeth, which extend radially from the annular portion. The stator core is divided into core segments in the circumferential direction. Each core segment has an arcuate portion and one of the teeth, which extends from the arcuate portion. The insulator insulates each coil wound around one of the teeth from the stator core. The insulator includes coupling portions at positions corresponding to the circumferential ends of the arcuate portions. Each coupling portion couples the adjacent core segments to be rotatable relative to each other. The insulator facilitates manufacture of the stator.

Abstract: A stator for a motor includes a stator core, an insulator, and coils. The stator core includes an annular portion and teeth, which extend radially from the annular portion. The stator core is divided into core segments in the circumferential direction. Each core segment has an arcuate portion and one of the teeth, which extends from the arcuate portion. The insulator insulates each coil wound around one of the teeth from the stator core. The insulator includes coupling portions at positions corresponding to the circumferential ends of the arcuate portions. Each coupling portion couples the adjacent core segments to be rotatable relative to each other. The insulator facilitates manufacture of the stator.

Abstract: A stator for a motor includes a stator core, an insulator, and coils. The stator core includes an annular portion and teeth, which extend radially from the annular portion. The stator core is divided into core segments in the circumferential direction. Each core segment has an arcuate portion and one of the teeth, which extends from the arcuate portion. The insulator insulates each coil wound around one of the teeth from the stator core. The insulator includes coupling portions at positions corresponding to the circumferential ends of the arcuate portions. Each coupling portion couples the adjacent core segments to be rotatable relative to each other. The insulator facilitates manufacture of the stator.

Abstract: The disclosed method produces a spline-grooved cylindrical member, e.g. torque converter front cover, including a cylindrical portion having a target wall thickness t2, from a plate blank having a plate thickness t1. An outer peripheral portion of a disc-shaped blank is plastically deformed by pressing it against a mandrel with the concave peripheral edge of a thickness-increasing roller, so that a thick wall portion, of a thickness greater than the plate thickness t1 of the blank, is formed in the cylindrical portion. The thick wall portion is then pressed against the mandrel by forming rollers to form spline grooves therein. Thus, the other portions of the product have a wall thickness which is not unnecessarily increased. In this manner, the wall thickness t2 of the cylindrical portion is not entirely dictated by the wall thickness t1 of the blank material.

Abstract: The present invention provides an internally-toothed member of reduced size and enhanced quality, durability and productivity in manufacture. This internally-toothed member has a first cylinder portion and a second cylinder portion which is larger in diameter than the first cylinder portion. First and second internal teeth are formed to protrude radially inwardly from inner peripheral surfaces of the first and second cylinder portions respectively. Because a meshing portion can be formed as second internal teeth protruding from an inner periphery of the second cylinder portion, the diameter of the internally-toothed member is relatively small. Because the area between the second internal teeth and a concave portion and the concave portion itself do not decrease in thickness during formation of the second internal teeth, it is possible to prevent cracking and to thereby enhance durability of the internally-toothed member.

Abstract: To make stress corrosion cracking caused by precipitation of a &bgr; layer (Mg2Al3) in a welding part (5) or in the periphery of the welding part (5) hard to occur. An apparatus body (1) and a header (3) formed of an aluminum alloy with precipitation of magnesium suppressed by standardized heat treatment are assembled and welded, and natural gas containing mercury is subjected to heat exchanging. There are provided with backing metal (4) disposed on the back of the inner wall surface of one header (3) prior to standardized heat treatment and placed in contact with the other apparatus body (1) at the time of assembling and welding, a welding part (5) formed by being assembled and welded using first welding metal containing magnesium at percent content not less than 2.

Abstract: To make stress corrosion cracking caused by precipitation of a &bgr; layer (Mg2Al3) in a welding part 5 or in the periphery of the welding part 5 hard to occur.

Abstract: An image transfer device includes a member for carrying a transfer material thereon and an image bearing member having an image thereon, the transfer material carrying member being subjected to a transfer corona therethrough to transfer the image from the image bearing member onto the transfer material. When the transfer material is separated from the transfer material carrying member by a separation pawl, that portion of the transfer material carrying member from a position in which the transfer material is in close contact with the carrying member to another position in which the transfer material is separated from the carrying member by the separation pawl is charged by a pair of corona chargers with the transfer material carrying member being located therebetween, so that the transfer material can more readily be separated from the carrying member.