Apparatus for driving light emitting element and system for driving light emitting element
AssigneeFuji Xerox Co., Ltd.
InventorChikaho Ikeda
Life of this patent
Estimating the term…
Abstract
In case of driving each of light emitting parts of a surface emitting laser, each of light emitting parts is made to be in forward-bias state and switches appropriately change bias voltage, which is lower than laser oscillation threshold voltage, and drive voltages, which are not less than the laser oscillation threshold voltage to directly apply the changed voltage to each of drive ends of the light emitting parts. Whereby, each of light emitting parts is driven.
Claims17
An apparatus for driving a light emitting element in response to input data, the light emitting element emitting light by causing a direct current to flow thereto, the apparatus comprising:
- a voltage driving section for driving the light emitting element with voltage;
- a current driving section for driving the light emitting element with a current;
- and
- a switching section for changing between voltage drive by the voltage driving section and current drive by the current driving section based on the input data.
A system for driving light emitting elements, the system comprising:
- an apparatus for driving a light emitting element in response to input data, the light emitting element emitting light by causing a direct current to flow thereto, the apparatus comprising:
- a voltage driving section for driving the light emitting element with voltage;
- a current driving section for driving the light emitting element with a current;
- and
- a switching section for changing between voltage drive by the voltage driving section and current drive by the current driving section based on the input data,
- a detecting section for detecting optical power of the plurality of light emitting elements;
- and
- a error amplifying section for comparing voltage corresponding to the detection result of the detecting section and a reference voltage to amplify the error therebetween,
- wherein a resistance value from an output end of the voltage source to a drive end of the light emitting element is smaller than an internal resistance value of the light emitting element;
- wherein a current flowing through the voltage source is smaller than a current flowing through the light emitting element;
- and
- wherein each of the plurality of apparatus for driving light emitting elements drives the light emitting element on a basis of outputs of the error amplifying section.
Dependencies are inferred from the claim text.