Abstract: An image-forming apparatus includes: an optical sensor that includes a light source unit which applies light having a light-emission main wavelength ? to a peripheral face of an image-supporting member, and a light-receiving unit which receives a reflected light thereof, so as to optically detect a toner pattern formed on a peripheral face of the image-supporting member, wherein the image-supporting member has at least one thin-film layer formed on the peripheral face thereof, and the thickness of an outermost surface thin-film layer is set so as to allow a reflectance function R(d) that indicates the relationship between a reflectance R of the peripheral face of the image-supporting member to light having a light-emission main wavelength ? from the light source unit and a thickness d (nm) of the outermost surface thin-film layer of the image-supporting member to satisfy: R(d)?0.75×{Rmax(d)?Rmin(d)}+Rmin(d).

Abstract: An object of the present invention is to provide a connection structure for sheet-metal parts that permits two sheet-metal parts to be screwed to each other with good conductivity by a simple process in a simple structure, and an image forming apparatus provided with the connection structure. Disclosed is a connection structure for connecting a first sheet-metal part (31) to a second sheet-metal part (41) by placing the sheet-metal parts (31) and (41) such that their respective contact surfaces face to each other and by connecting the contact surfaces by a screw (50). A first pilot hole (32) that is smaller than the screw (50) is made in the first sheet-metal part (31), and a plurality of first small holes (33) that are smaller than the first pilot hole (32) are made in the first sheet-metal part (31), around the first pilot hole (32).

Abstract: An image-forming apparatus, comprising: an optical sensor that includes a light source unit which applies light having a light-emission main wavelength ? to a peripheral face of an image-supporting member, and a light-receiving unit which receives a reflected light thereof, so as to optically detect a toner pattern formed on a peripheral face of the image-supporting member, wherein the image-supporting member has at least one thin-film layer formed on the peripheral face thereof, and the thickness of an outermost surface thin-film layer is set so as to allow a reflectance function R(d) that indicates the relationship between a reflectance R of the peripheral face of the image-supporting member to light having a light-emission main wavelength ? from the light source unit and a thickness d (nm) of the outermost surface thin-film layer of the image-supporting member to satisfy the following conditional expression: R(d)?0.