LIGHT SOURCE CONTROL DEVICE AND LIGHT SOURCE CONTROL METHOD
First Claim
1. A light source control device that controls multiple light sources connected in parallel, the light source control device comprising:
- a constant current supplying part that supplies a predetermined current to said multiple light sources;
a switching part capable of interrupting supply of said current from said constant current supplying part to said multiple light sources independently;
a failure detecting part that determines whether a short-circuit failure occurs in any of said multiple light sources based on respective currents flowing in said multiple light sources while said current is supplied from said constant current supplying part to said multiple light sources;
a current sensing part that senses the respective amounts of currents flowing in said multiple light sources while said current is supplied from said constant current supplying part to said multiple light sources;
a short-circuit specifying part that specifies a light source belonging to said multiple light sources and subjected to a short-circuit failure based on a result of the determination by said failure detecting part and the current amounts sensed by said current sensing part; and
a controller that makes said switching part interrupt supply of a current to said light source specified by said short-circuit specifying part, said controller making said constant current supplying part supply a light source belonging to said multiple light sources and not specified by said short-circuit specifying part with a current not exceeding a current responsive to the number of such light sources not specified.
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Accused Products
Abstract
A microcomputer of a light source control device specifies an LED belonging to LEDs and subjected to a short-circuit failure based on a result of determination by a short-circuit failure detecting circuit and current amounts sensed by current sensing circuits respectively. The microcomputer makes corresponding one of switching elements interrupt supply of a current to the specified LED. The microcomputer makes a constant current circuit supply an LED not specified with a current not exceeding a current responsive to the number of such LEDs not specified.
13 Citations
9 Claims
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1. A light source control device that controls multiple light sources connected in parallel, the light source control device comprising:
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a constant current supplying part that supplies a predetermined current to said multiple light sources; a switching part capable of interrupting supply of said current from said constant current supplying part to said multiple light sources independently; a failure detecting part that determines whether a short-circuit failure occurs in any of said multiple light sources based on respective currents flowing in said multiple light sources while said current is supplied from said constant current supplying part to said multiple light sources; a current sensing part that senses the respective amounts of currents flowing in said multiple light sources while said current is supplied from said constant current supplying part to said multiple light sources; a short-circuit specifying part that specifies a light source belonging to said multiple light sources and subjected to a short-circuit failure based on a result of the determination by said failure detecting part and the current amounts sensed by said current sensing part; and a controller that makes said switching part interrupt supply of a current to said light source specified by said short-circuit specifying part, said controller making said constant current supplying part supply a light source belonging to said multiple light sources and not specified by said short-circuit specifying part with a current not exceeding a current responsive to the number of such light sources not specified. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method of controlling multiple light sources connected in parallel, comprising the steps of:
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(a) supplying a current to said multiple light sources from a constant current supplying part; (b) determining whether a short-circuit failure occurs in any of said multiple light sources based on respective currents flowing in said multiple light sources while said current is supplied to said multiple light sources; (c) sensing the respective amounts of currents flowing in said multiple light sources while said current is supplied to said multiple light sources; (d) specifying a light source belonging to said multiple light sources and subjected to a short-circuit failure based on a result of the determination in said step (b) and the current amounts sensed in said step (c); and (e) making a switching part interrupt supply of a current to said light source specified in said step (d) and making said constant current supplying part supply a light source belonging to said multiple light sources and not specified in said step (d) with a current not exceeding a current responsive to the number of such light sources not specified.
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Specification