Patent ID: 9250557
Filing Date: 2016-02-02
CPC Classification: G02B,G03G

Claim Text:
1. An image forming apparatus comprising: a photosensitive member; a light-emitting element for emitting a laser beam; a driving unit configured to drive the light-emitting element by a driving current, wherein the driving unit causes the light-emitting element to emit light at a first light emission intensity and at a second light emission intensity in a laser light emission region lower than the first light emission intensity; a polygon mirror configured to scan the photosensitive member with the laser beam by rotating at a predetermined speed; and a developing unit configured to form an image on the photosensitive member by causing toner to adhere to the photosensitive member scanned with the laser beam, wherein the driving unit causes the light-emitting element to emit light at the first light emission intensity toward an image portion within an image forming region on the photosensitive member where toner is to be adhered, and causes the light-emitting element to emit light at the second light emission intensity in the laser light emission region toward a non-image portion within an image forming region on the photosensitive member where toner is not to be adhered, the second light emission intensity is larger than an emission intensity of a laser emission emitted from the light-emitting element and the second light emission intensity is an emission intensity which causes toner not to adhere to the photosensitive member, wherein the driving unit causes the light-emitting element to emit light at the first light emission intensity with a driving current obtained by adding a second driving current to a first driving current, and causes the light-emitting element to emit light at the second light emission intensity in the laser light emission region with the second driving current, wherein the driving unit performs a first adjustment adjusting the first driving current for causing the light-emitting element to emit light at the first light emission intensity, and a second adjustment adjusting the second driving current for causing the light-emitting element to emit light at the second light emission intensity in the laser light emission region, and wherein the driving unit performs the first adjustment and the second adjustment during a time period after the polygon mirror starts rotating until the predetermined speed is reached, and wherein, during the time period, the driving unit initially performs the second adjustment before the first adjustment is performed.