Abstract: A planar light emitting device provided with a light source; a sheet-like light guide that guides light from the light source in a planar direction, and has a plurality of light emitting regions, and a through slit formed between the light emitting regions to penetrate the light guide in a thickness direction; a switch sheet arranged so as to face one of the front face and the rear face of the light guide; and a light-blocking layer that has a flange portion that covers an opening edge portion of the through slit, a main body portion that covers at least one of the mutually facing inner wall surfaces of the through slit so as to form a space in the interior of the through slit and that continuous with the flange portion, and a bottom portion that is extended from a lower portion of the main body portion.

Abstract: A planar light emitting device provided with a light source; a sheet-like light guide that guides light from the light source in a planar direction, and has a plurality of light emitting regions, and a through slit formed between the light emitting regions to penetrate the light guide in a thickness direction; a switch sheet arranged so as to face one of the front face and the rear face of the light guide; and a light-blocking layer that has a flange portion that covers an opening edge portion of the through slit, a main body portion that covers at least one of the mutually facing inner wall surfaces of the through slit so as to form a space in the interior of the through slit and that continuous with the flange portion, and a bottom portion that is extended from a lower portion of the main body portion.

Abstract: A switch device includes: a circuit board provided with a fixed contact; a deformable contact arranged above the circuit board, and configured to deform and come into contact with the fixed contact in response to pressure from above; a switch holding sheet covering a surface of the circuit board provided with the deformable contact, and configured to retain the deformable contact on the circuit board; a light-guide sheet placed over the switch holding sheet, and allowing light to pass through its inside; a light-emitting diode configured to cause the light to fall incident and enter the inside of the light-guide sheet; and a protrusion forming a gap between the switch holding sheet and the light-guide sheet in a position corresponding to the deformable contact.

Abstract: A sheet switch module of the present invention includes: a light source; a light guide that guides light from the light source; a sheet switch disposed on the back side of the light guide in a thickness direction of the light guide; and a groove formed in the thickness direction of the light guide in at least one of a surface and the back of the light guide.

Abstract: There is provided a slant short-period grating which is obtainable by irradiating light onto an optical fiber whose core is formed from quartz glass to which has been doped a photosensitive dopant that changes a refractive index of the quartz glass by light irradiation, and whose clad has one or two or more layers with at least the layer that is adjacent to the core being a photosensitive layer formed from quartz glass to which has been doped a photosensitive dopant that changes a refractive index of the quartz glass by light irradiation. In this slant short-period grating a grating portion is formed by changing the refractive index of the photosensitive layer of the clad and the core at a predetermined grating period along a longitudinal direction of the optical fiber by a predetermined slant angle.

Abstract: There is provided a slant short-period grating which is obtainable by irradiating light onto an optical fiber whose core is formed from quartz glass to which has been doped a photosensitive dopant that changes a refractive index of the quartz glass by light irradiation, and whose clad has one or two or more layers with at least the layer that is adjacent to the core being a photosensitive layer formed from quartz glass to which has been doped a photosensitive dopant that changes a refractive index of the quartz glass by light irradiation. In this slant short-period grating a grating portion is formed by changing the refractive index of the photosensitive layer of the clad and the core at a predetermined grating period along a longitudinal direction of the optical fiber by a predetermined slant angle.