Abstract: An optical gel member to be used in a gap between light-emitting diode which is a backlight light source of an optical device and light guide plate, as well as an assembling method for an optical device and an optical device using the same. The optical gel member etc. to be used in an interposed state between light guide plate and light-emitting device consisting of a light-emitting diode (LED) in an optical device, characterized by satisfying the following requirements (i) to (iii). (i) The optical gel member consists of a transparent gel such as silicone type gel or acryl type gel, which has a hardness of 0 to 80 in JIS-A hardness according to JIS K6253, or 20 to 200 in penetration (25° C.) in accordance with JIS K2207; (ii) The optical gel member is in a string-like form, and the peripheral surface thereof is in contact with light guide plate and light-emitting device; (iii) The optical gel member has a repulsive force of 12 MPa or less at a compression rate of 30%.

Abstract: A body frame for a motor bicycle includes a main frame, a head tube provided at a front end of the main frame and down tubes extending rearward from the main frame. The main frame, head tube and down tubes are cast with a light alloy into an integral form of a hollow and thin-wall structure. A production process of the body frame, wherein an integrally-formed core, which is formed into a shape similar to that of the body frame, is hollow and has good permeability. A molten metal is charged into the mold and a vacuum is applied to the interior of the core.

Abstract: A body frame for a motor bicycle includes a main frame, a head tube provided at a front end of the main frame and down tubes extending rearward from the main frame. The main frame, head tube and down tubes are cast with a light alloy into an integral form of a hollow and thin-wall structure. A production process of the body frame, wherein an integrally-formed core, which is formed into a shape similar to that of the body frame, is hollow and has good permability. A molten metal is charged into the mold and a vacuum is applied to the interior of the core. The molten metal is charged into a cavity defined between the core and the molding surface of the mold by a low-pressure casting method, and the molten metal is solidified so as to cast the body frame.