Patent ID: 7761037

Claim:
An image formation apparatus comprising: a containing section that contains a developer, the containing section having an opening; a developer carrier that is exposed at the opening and carries a developer, the developer carrier being capable of rotating, the developer carrier rotating on the basis of either a first speed mode or a second speed mode so as to develop a latent image that is formed on an image carrier, the first speed mode having a faster speed of rotation of the developer carrier, the second speed mode having a slower speed of rotation of the developer carrier; a replenishing member that replenishes a developer into the containing section; a detecting member that detects whether the height of a developer that is contained in the containing section is at a replenishment start level at which replenishment performed by the replenishing member should be started or not and further detects whether the height of a developer that is contained in the containing section is at a replenishment end level at which replenishment performed by the replenishing member should be ended or not; and a controlling section that controls the replenishment of a developer that is performed by the replenishing member, the controlling section commanding the replenishing member to replenish a developer until the detecting member detects that the height of the developer that is contained in the containing section is at the replenishment end level if the detecting member detects that the height of the developer that is contained in the containing section is at the replenishment start level when the developer carrier that rotates on the basis of the first speed mode develops the latent image, whereas the controlling section commanding the replenishing member to replenish a developer by a predetermined amount if the detecting member detects that the height of the developer that is contained in the containing section is at the replenishment start level when the developer carrier that rotates on the basis of the second speed mode develops the latent image.