Current Source to Drive a Light Source in an Optical Sensor System
AssigneeOsram Sylvania Inc.
InventorsVipin C. Madhani, Alan Adamsky
Life of this patent
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Abstract
A current source circuit to drive a light source in an optical sensor system is disclosed. The current source includes an inductor connected in series with a resistor, and a diode coupled in parallel with the inductor and resistor. The current source is configured to receive a regulated direct current (DC) voltage and to provide the current through the inductor to the light source when a switch is closed, and to divert current through the inductor to the diode when the switch is open.
Claims17
A light source circuit for an optical sensor system, the circuit comprising:
- a power supply to provide a regulated direct current (DC) voltage output;
- a current source coupled to the power supply to receive the regulated DC voltage output, wherein the current source comprises:
- an inductor connected in series with a resistor;
- and
- a diode coupled in parallel with the inductor and resistor;
- a light source coupled to the current source;
- and
- a switch, whereby the current source is configured to provide current through the inductor to the light source when the switch is closed and divert current through the inductor to the diode when the switch is open.
A current source circuit for providing current to a light source under the control of a switch in an optical sensor system, the circuit comprising:
- an inductor connected in series with a resistor;
- and
- a diode coupled in parallel with the inductor and resistor;
- wherein the current source circuit is configured to receive a regulated direct current (DC) voltage from a power supply and to provide the current through the inductor to the light source when the switch is closed, and to divert current through the inductor to the diode when the switch is open.
An optical sensor system comprising:
- a controller;
- a light source circuit coupled to the controller to drive a light source in response to control signals received from the controller, the light source circuit comprising:
- a power supply to provide a regulated direct current (DC) voltage output;
- a current source coupled to the power supply to receive the regulated DC voltage output, the current source comprising:
- an inductor connected in series with a resistor;
- and
- a diode coupled in parallel with the inductor and resistor;
- a light source coupled to the current source;
- and
- a switch, whereby the current source is configured to provide current through the inductor to the light source when the switch is closed, and divert current through the inductor to the diode when the switch is open;
- transmission optics to direct light from the light source toward an object;
- receiver optics to receive light reflected from the object;
- and
- detector circuits to convert the reflected light to one or more electrical signals;
- wherein the controller is configured to provide a data signal output representative of a distance to at least one point on the object in response to the one or more electrical signals.
A method of providing current to a light source under the control of a switch in an optical sensor system, the method comprising:
- providing the current through an inductor to the light source when the switch is closed;
- and
- diverting current through the inductor through a diode when the switch is open.
Dependencies are inferred from the claim text.