| CPC A61B 5/02427 (2013.01) [A61B 5/0261 (2013.01); A61B 5/7217 (2013.01); G01J 1/4204 (2013.01); H05B 47/155 (2020.01)] | 17 Claims |
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13. A method of detecting a light signal, the method comprising:
controlling, by a processor, a light source to be turned off and receiving an ambient light;
generating, by the processor, a first output signal based on the ambient light;
controlling, by the processor, the light source to be turned on to radiate light toward an object;
receiving, by light receiver, a transmitted light corresponding to the light radiated toward the object and the ambient light from the light source;
generating, by the processor, a second output signal based on the transmitted light and the ambient light; and
generating, by an operator, a transmitted light signal from which noise is removed by differentially operating the second output signal from the first output signal;
after the generating the first output signal, reducing, by the operator, a ramp signal when the first output signal is received by the operator;
performing, by the operator, a first counting from a time when the ramp signal is reduced to a time when a magnitude of the ramp signal is less than or equal to a magnitude of the first output signal; and
reducing, by the operator, the ramp signal when the second output signal is received,
wherein differentially operating the second output signal is performing a second counting from the time when the ramp signal is reduced to a time when the magnitude of the ramp signal is less than or equal to a magnitude of the second output signal,
wherein the second counting starts from a stored result of the first counting, and
wherein the first counting and the second counting are in different directions.
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