Light source intensity control device
First Claim
Patent Images
1. A intensity control device for a light source comprising:
- current means, connected to the light source, for providing current to the light source;
sensing means, proximate to the light source, for providing an indication of temperature of the light source;
conditioning means, for receiving the indication of the temperature of the light source, and providing a temperature indication current signal;
heating means, proximate to the light source and connected to said conditioning means, for heating the light source in response to a magnitude of the temperature indication current signal; and
temperature-current profiling means, connected to said conditioning means and to said current means, for receiving the temperature indication current signal and for profiling an output signal to said current means to maintain the light source at a constant intensity.
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Abstract
A light source device having a controlled current source that maintains a constant intensity of light from the source during changes in light source temperature, particularly at warm-up. The light source is heated to speed up warm-up and to maintain constant temperature of the source during operation under varying ambient temperatures. Control of the current to the light source is determined by the temperature profile circuit with signals via a temperature signal conditioner from a temperature sensor proximate to the light source. Control of the heater is ultimately dictated by temperature sensor signals.
36 Citations
14 Claims
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1. A intensity control device for a light source comprising:
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current means, connected to the light source, for providing current to the light source; sensing means, proximate to the light source, for providing an indication of temperature of the light source; conditioning means, for receiving the indication of the temperature of the light source, and providing a temperature indication current signal; heating means, proximate to the light source and connected to said conditioning means, for heating the light source in response to a magnitude of the temperature indication current signal; and temperature-current profiling means, connected to said conditioning means and to said current means, for receiving the temperature indication current signal and for profiling an output signal to said current means to maintain the light source at a constant intensity. - View Dependent Claims (2)
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3. A intensity control device for a light source comprising:
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current means, connected to the light source, for providing current to the light source; sensing means, proximate to the light source, for providing an indication of temperature of the light source; conditioning means, for receiving the indication of the temperature of the light source, and providing a temperature indication voltage signal; and temperature-current profiling means, connected to said conditioning means and to said current means, for receiving the temperature indication voltage signal and for profiling an output signal to said current means to maintain the light source at a constant intensity. - View Dependent Claims (4)
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5. A light source intensity control device comprising:
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a light source; a temperature sensor proximate to said light source; a temperature signal conditioner connected to said temperature sensor; a temperature-current profile circuit connected to said temperature signal conditioner; a current source connected to said temperature-current profile circuit and to said light source; a heater control circuit connected to said temperature signal conditioner; and a heater, connected to said heater control circuit, proximate to said light source. - View Dependent Claims (6)
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7. A light source intensity control device comprising:
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a laser source having an anode and a cathode a temperature sensor, proximate to said laser diode, having first and second terminals; a first transistor having a drain connected to the cathode of said laser source, and having a gate and a source; a first amplifier having an output connected to the gate of said first transistor, having an inverting input connected to the source of said first transistor, and having a non-inverting input; a first resistor having a first terminal connected to the inverting input of said first amplifier and having a second terminal; a second resistor having a first terminal connected to the non-inverting input of said first amplifier and having a second terminal; a third resistor having a first terminal connected to the non-inverting input of said first amplifier and having a second terminal; a first diode, having an anode connected to the non-inverting input of said first amplifier and having a cathode; a fourth resistor having a first terminal connected to the cathode of said first diode, and having a second terminal; a fifth resistor having a first terminal connected to the cathode of said first diode and having a second terminal; a second diode having a cathode connected to the second terminal of said fifth resistor and having an anode; a sixth resistor having a first terminal connected to the anode of said second diode and having a second terminal; a seventh resistor having a first terminal connected to the second terminal of said fifth resistor; a second amplifier having an output connected to the second terminal of said seventh resistor and having a non-inverting input and an inverting input; an eighth resistor having a first terminal connected to the output of said second amplifier and having a second terminal connected to the inverting input of said second amplifier; a ninth resistor having a first terminal connected to the non-inverting input of said second amplifier and having a second terminal; and a tenth resistor having a first terminal connected to the inverting input of said second amplifier and having a second terminal. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14)
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Specification