Providing a suitable output current to a laser diode
AssigneeRicoh Company, Ltd.
InventorShinichi Kubota
Life of this patent
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Abstract
A laser diode driving circuit capable of providing a suitable output current to a laser diode is disclosed. The laser diode driving circuit includes a current supply, a first pseudo laser diode, a second pseudo laser diode, and an output current mirror circuit. An input current provided by the current supply is output through the output current mirror circuit to the laser diode. By making the characteristic of each of the first and second pseudo laser diodes substantially equal to the characteristic of the laser diode, the non-linearity between the input current and the output current is compensated.
Claims13
A light emitting system comprising:
- a laser diode having a predetermined characteristic, said laser diode being configured to generate a light according to an output current;
- a controller configured to generate a control signal;
- and
- a laser diode driving circuit configured to supply said output current to the laser diode in accordance with the control signal, and comprising
- a current supply configured to supply a predetermined current;
- a first pseudo laser diode configured to receive a first current being substantially equal or proportional to the predetermined current;
- a second pseudo laser diode configured to receive a second current substantially equal to the first current;
- and
- an output circuit configured to provide said output current, with the output current being substantially equal or proportional to at least one of the first current and the second current,
- wherein each of said first pseudo laser diode and said second pseudo laser diode has a characteristic substantially the same as the predetermined characteristic of the laser diode.
A laser diode driving circuit for driving a laser diode, comprising:
- a current supply configured to supply a predetermined current;
- a first pseudo laser diode configured to receive a first current being substantially equal or proportional to the predetermined current;
- a second pseudo laser diode configured to receive a second current substantially equal to the first current;
- and
- an output circuit configured to provide an output current to the laser diode, with the output current being substantially equal or proportional to at least one of the first current and the second current.
Dependencies are inferred from the claim text.