Light-source control device, light-source control method, image reading device, and image forming apparatus
AssigneeRicoh Company, Ltd.
InventorTadaaki Oyama
Life of this patent
Estimating the term…
Abstract
A light-source control device includes a light source including a first light emitter for emitting light and a second light emitter for emitting light due to the light emitted by the first light emitter; a constant current unit configured to maintain a current constant that is input via the light source from a power supply; a switching unit configured to switch the current to be input to the constant current unit at a designated duty ratio and cycle; and a control unit configured to control the current applied to the light source so that a rise transition time and a fall transition time of the current applied to the light source are nearly equal to each other.
Claims15
A light-source control device comprising:
- a light source including a first light emitter for emitting light and a second light emitter for emitting light due to the light emitted by the first light emitter;
- a constant current unit configured to maintain a current constant that is input via the light source from a power supply;
- a switching unit configured to switch the current to be input to the constant current unit at a designated duty ratio and cycle;
- and
- a control unit configured to control the current applied to the light source so that a rise transition time and a fall transition time of the current applied to the light source are nearly equal to each other.
A light-source control device comprising:
- a light source including a first light emitter for emitting light and a second light emitter for emitting light due to the light emitted by the first light emitter;
- a constant current means for maintaining a current constant that is input via the light source from a power supply;
- a switching means for switching the current to be input to the constant current means at a designated duty ratio and cycle;
- and
- a control means for controlling the current applied to the light source so that a rise transition time and a fall transition time of the current applied to the light source are nearly equal to each other.
A light-source control method comprising:
- maintaining, by a constant current unit, a current constant that is input via a light source from a power supply, the light source including a first light emitter for emitting light and a second light emitter for emitting light due to the light emitted by the first light emitter;
- switching the current to be input to the constant current unit at a designated duty ratio and cycle;
- and
- controlling the current applied to the light source so that a rise transition time and a fall transition time of the current applied to the light source are nearly equal to each other.
Dependencies are inferred from the claim text.