Abstract: A substrate for a surface acoustic wave device is constituted of a piezoelectric material and includes a first surface on which a surface acoustic wave propagates, and a second surface located opposite to the first surface. The second surface has an arithmetic mean roughness (Ra) of 0.2 ?m to 0.4 ?m, and there is satisfied either of the relationship between the arithmetic mean roughness (Ra) and mean spacing (S) of local peaks of Ra/S?11, and the relationship between the arithmetic mean roughness (Ra) and mean spacing (Sm) of irregularities of Ra/Sm?6.7. Further, the second surface has a maximum height (Rmax) of 2.5 ?m to 4.5 ?m, and there is satisfied either of the relationship between the maximum height (Rmax) and mean spacing (S) of local peaks of Rmax/S?130, and the relationship between the maximum height (Rmax) and mean spacing (Sm) of irregularities of Rmax/Sm?80.

Abstract: A substrate for a surface acoustic wave device is constituted of a piezoelectric material and includes a first surface on which a surface acoustic wave propagates, and a second surface located opposite to the first surface. The second surface has an arithmetic mean roughness (Ra) of 0.2 ?m to 0.4 ?m, and there is satisfied either of the relationship between the arithmetic mean roughness (Ra) and mean spacing (S) of local peaks of Ra/S?11, and the relationship between the arithmetic mean roughness (Ra) and mean spacing (Sm) of irregularities of Ra/Sm?6.7. Further, the second surface has a maximum height (Rmax) of 2.5 ?m to 4.5 ?m, and there is satisfied either of the relationship between the maximum height (Rmax) and mean spacing (S) of local peaks of Rmax/S?130, and the relationship between the maximum height (Rmax) and mean spacing (Sm) of irregularities of Rmax/Sm?80.

Abstract: An electronic apparatus is provided. The electronic apparatus includes a case body including a single crystal body in at least a portion thereof, the single crystal body containing alumina (Al2O3) as a main component; a plurality of information processing devices in the case body; and a thermally conductive portion that thermally connects at least one of the information processing devices to the single crystal body.

Abstract: [Object] To suppress cracking and breakage of a light-transmissive cover plate when an electronic apparatus receives an impact. [Solution] An electronic apparatus is provided. The electronic apparatus includes a case body including a single crystal body in at least a portion thereof, the single crystal body containing alumina (Al2O3) as a main component; a plurality of information processing devices in the case body; and a thermally conductive portion that thermally connects at least one of the information processing devices to the single crystal body.

Abstract: An electronic apparatus and a light-transmissive cover plate are disclosed. The electronic apparatus includes an image display device that includes an image display surface; a casing that houses at least a portion of periphery of the image display device; a light-transmissive cover plate that includes a first surface facing the image display surface, at least a peripheral edge region of the first surface is bonded to the casing; and a joining member that bonds the peripheral edge region of the first surface to the casing. The joining member has a Young's modulus smaller than that of the light-transmissive cover plate. The light-transmissive cover plate includes a gradual reduction area, and in this gradual reduction area, thickness is gradually reduced towards an outermost edge. At least a portion of the peripheral edge region of the first surface of the light-transmissive cover plate is included in the gradual reduction area.

Abstract: An electronic apparatus is disclosed. The electronic apparatus includes an exterior body, a wireless communication unit, and a display device. The exterior body includes a wireless communication unit, a display device and an exterior body. The exterior body includes a light-transmissive cover plate and a case member. The light-transmissive cover plate includes: first and second surfaces opposite to each other; and a single crystal body containing alumina (Al2O3) as a main component. The case member is disposed at an opposite side to the light-transmissive cover plate with respect to the display device and includes a single crystal body containing alumina (Al2O3) as a main component. The wireless communication unit and the display device are in the exterior body. The display device includes a display surface that faces the first surface.

Abstract: An electronic apparatus and a light-transmissive cover plate are disclosed. The electronic apparatus includes an image display device that includes an image display surface; a casing that houses at least a portion of periphery of the image display device; a light-transmissive cover plate that includes a first surface facing the image display surface, at least a peripheral edge region of the first surface is bonded to the casing; and a joining member that bonds the peripheral edge region of the first surface to the casing. The joining member has a Young's modulus smaller than that of the light-transmissive cover plate. The light-transmissive cover plate includes a gradual reduction area, and in this gradual reduction area, thickness is gradually reduced towards an outermost edge. At least a portion of the peripheral edge region of the first surface of the light-transmissive cover plate is included in the gradual reduction area.

Abstract: An electronic apparatus and a light-transmissive cover plate are disclosed. The electronic apparatus includes an image display device that includes an image display surface; a casing that houses at least a portion of periphery of the image display device; a light-transmissive cover plate that includes a first surface facing the image display surface, at least a peripheral edge region of the first surface is bonded to the casing; and a joining member that bonds the peripheral edge region of the first surface to the casing. The joining member has a Young's modulus smaller than that of the light-transmissive cover plate. The light-transmissive cover plate includes a gradual reduction area, and in this gradual reduction area, thickness is gradually reduced towards an outermost edge. At least a portion of the peripheral edge region of the first surface of the light-transmissive cover plate is included in the gradual reduction area.

Abstract: A hemispheric lens of a single crystal having a refractive index of 2.0 or over is used as a SIL lens of an optical system for optical recording. The single crystal is LiNbO3, LiTaO3, rutile phase TiO2, PbMoO4, TeO2, SrTiO3, ZrO2, SrNbO3, SrTaO3, CaNbO3, CaTaO3, CaTiO3, KNbO3, KTaO3, BaZrO3, SrZrO3, CaZrO3, KNbO3, KTaO3, BaZrO3, SrZrO3, CaZrO3, ZnWO4, ZnMoO4, CdWO4, CdMoO4, PbWO4, Bi20SiO12, Bi20GeO12, Bi4Si3O12, Bi4Ge3O12, GaP, ZnTe, ZnSe, Cu3TaSe4 or ZnS.