Abstract: A watch component is formed of a metal member formed into a component shape. A surface of the metal member includes a coated region being coated with a coating material having a color different from a material color of the metal member and an exposed region from which the material color of the metal member is exposed. A boundary part between the coated region and the exposed region forms a blade-pattern-like design.

Abstract: A timepiece component includes a base member, a first layer provided at the base member, and a second layer provided at the first layer. The second layer has lower hardness than the first layer.

Abstract: A metal powder production method includes a powdering step of causing a jet flow to collide with a molten metal that flows down, thereby powdering the molten metal, and a coating step, for a metal powder, of immersing the powdered molten metal in a liquid containing a non-aqueous liquid, thereby forming a suspension of the metal powder, wherein the powdering step and the coating step are performed in a same apparatus, the non-aqueous liquid contains a raw material of an electrically insulating material, and in the metal powder, a surface is coated with the electrically insulating material.

Abstract: An optical element includes a first optical component and a second optical component each having light transmission properties; and a bonding film bonding together the first and the second optical components. The bonding film is formed by plasma polymerization and includes an Si skeleton having a random atomic structure including a siloxane (Si—O) bond and leaving groups binding to the Si skeleton. The first and the second optical components are bonded together by the bonding film having adhesive properties provided by applying energy to at least a part of the bonding film to eliminate the leaving groups from the Si skeleton at a surface of the bonding film. Additionally, the bonding film is formed so as to have approximately the same refractive index as that of at least one of the first and the second optical components by adjusting a film forming condition of the plasma polymerization.

Abstract: A bonding method includes forming a bonding film on a surface of a base member by plasma polymerization, the bonding film including an Si skeleton of a random atomic structure including a siloxane (Si—O) bond and leaving groups binding to the Si skeleton; applying UV light to the bonding film to eliminate the leaving groups at the surface of the bonding film from the Si skeleton so as to provide adhesion properties to the bonding film, an accumulated amount of the UV light being adjusted to control a refractive index of the bonding film; and bonding the base member and an object together via the bonding film to obtain a bonded structure.

Abstract: An optical element includes: first and second optical components, at least one of the first and second optical components having a light transmission characteristic; and a bonding film bonding the first and the second optical components together, the bonding film being formed by plasma polymerization and including an Si skeleton having a random atomic structure including a siloxane (Si—O) bond and a leaving group binding to the Si skeleton. The first and second optical components are bonded together by the adhesive properties of the bonding film which are provided by applying energy to at least a part of the bonding film to eliminate the leaving group from the Si skeleton at a surface of the bonding film. Preferably, an average thickness of the bonding film is equal to or less than a wavelength of light passing through the optical component having the light transmission characteristic.