Patent ID: 9268253
Filing Date: 2016-02-23
CPC Classification: B41J,G02B,G03G

Claim Text:
1. An image forming apparatus comprising: a photosensitive member; a light source configured to emit a light beam for exposing the photosensitive member to light when supplied with a driving current; a deflection unit configured to deflect the light beam such that the light beam scans the photosensitive member; an output unit configured to output data about temperature of the light source; a control unit configured to switch, in one scanning cycle of the light beam, between an electrostatic latent image forming mode in which the light source is configured to emit the light beam based on the image data, whereby an electrostatic latent image is formed on the photosensitive member, and a light amount control mode in which a light amount of the light beam is controlled in timing different from the electrostatic latent image forming mode; a light receiving unit configured to receive the light beam emitted from the light source; a setting unit configured to set a value of a current to be supplied to the light source such that a light amount received by the light receiving unit coincides with a target light amount; a first current supply unit configured to control a value of the driving current with reference to the value of the current set by the setting unit, and supply the driving current to the light source based on the image data; and a second current supply unit configured to supply a correction current to the light source in a state where the driving current is supplied from the first current supply unit to the light source, the correction current gradually increasing with an advance of time based on the data about the temperature of the light source output from the output unit and the value of the driving current controlled by the first current supply unit, so that the light amount of the light beam emitted by supply of the driving current is not attenuated with an advance of time.