Abstract: To provide a photovoltaic device and a light condensing device having a high condensing rate which can be manufactured easily and at low cost. This light condensing device is provided with: a light-guiding subtract for causing light to propagate between a rear-side surface and a front-side surface for receiving light from a light source; a reflective layer for light guiding, in which a reflection-type hologram is formed for reflecting light incident at a first incidence angle less than the critical angle of the light-guiding substrate at a reflection angle greater than the critical angle, the reflective layer being provided to the rear-side surface; and an emission window for causing light incident at a second incidence angle equal to or greater than the critical angle to be emitted from the light-guiding substrate, the emission window being provided to the front-side surface and/or the rear-side surface.

Abstract: A transparent film whose back-face has excellent resistance to scratch, and a surface protection film having the transparent film are provided. A transparent film has a substrate layer formed of a transparent resin material, and a back-face layer with a thickness of 1 ?m or less provided on a first face thereof. In a scratch test of the transparent film, the failure initiation load of the back-face layer is 50 mN or greater and the friction coefficient of the back-face layer is 0.4 or less.

Abstract: Provided is an improved method of joining a protective tape having one object to suppress generation of bending of a semiconductor wafer after a back-grinding process. The protective tape is supplied toward the semiconductor wafer suction-held on a chuck table, and an intermediate sheet is supplied along an upper side of the protective tape. Then, the intermediate sheet is interposed between a joining member and the protective tape along a surface of a base material in the protective tape so as to be movable. Under this state, the joining member and the semiconductor wafer move relative to each other in a horizontal direction, whereby the protective tape is joined to a surface of the semiconductor wafer.