Patent ID: 8160476

Claim:
An image forming apparatus comprising: a latent image carrier carrying a latent image on a surface thereof; a latent image writing unit drawing the latent image on the surface; a development unit developing the latent image using toner; a latent image carrier unit having at least the latent image carrier and being removable from a body of the image forming apparatus; a pair of first positioning protrusions, being cylindrically shaped and disposed on the latent image carrier unit, each first positioning protrusion being engaged with a groove or a slit disposed on each of two surfaces of the image forming apparatus body facing each other; an abutted portion disposed on the groove or the slit, the abutted portion abutting the respective first positioning protrusion to position the latent image carrier unit in an installation and removal direction relative to the image forming apparatus body in the image forming apparatus body when the latent image carrier unit is installed on the image forming apparatus body; and a pair of second positioning protrusions, shifted in the installation and removal direction and disposed on the latent image carrier unit, each second positioning protrusion disposed above a respective first positioning protrusion in a vertical direction, positioning the latent image carrier unit at a position different from a position of the respective first positioning protrusion and being shifted from the respective first positioning protrusion in the installation and removal direction in order to engage the respective groove or the respective slit engaged with the respective first positioning protrusion when the latent image carrier unit is installed on the image forming apparatus body, wherein each second positioning protrusion is shifted away from the respective first positioning protrusion by an acute angle defined by a y-axis and a line having a slope greater than one.