Patent ID: 7840171

Claim:
A developing unit of an image forming apparatus, comprising: a waste toner housing which comprises an upper housing and a lower housing which face each other, in which a photosensitive medium and a cleaning member to clean a surface of the photosensitive medium are installed, and which collects waste toner removed by the cleaning member in a space formed by the upper housing and the lower housing; a toner housing which is spaced apart from an external wall of the lower housing of the waste toner housing at a predetermined distance, which is disposed so that a laser beam passes through a space between the toner housing and the waste toner housing, which contains toner, and which comprises a developing roller to supply the toner on the surface of the photosensitive medium; and at least one support unit which is formed in the lower housing of the waste toner housing to contact an upper housing of the waste toner housing so as to prevent interference with a light path of the laser beam caused due to deformation of the lower housing by preventing deformation of the lower housing.