US 11,908,959 B1
Light sensor with voltage reversing mechanism detecting light from an ambient light source and a light emitting component
Jia-Hua Hong, Hsinchu (TW); and Chih-Yuan Chen, Hsinchu (TW)
Assigned to ANPEC ELECTRONICS CORPORATION, Hsinchu (TW)
Filed by ANPEC ELECTRONICS CORPORATION, Hsinchu (TW)
Filed on Oct. 21, 2022, as Appl. No. 17/970,813.
Claims priority of application No. 111128077 (TW), filed on Jul. 27, 2022.
Int. Cl. H01L 31/02 (2006.01); G01J 1/44 (2006.01); G01J 1/42 (2006.01); H05B 47/11 (2020.01)
CPC H01L 31/02016 (2013.01) [G01J 1/4204 (2013.01); G01J 1/44 (2013.01); H01L 31/02002 (2013.01); H05B 47/11 (2020.01)] 12 Claims
OG exemplary drawing
 
1. A light sensor having a voltage reversing mechanism, comprising:
a photoelectric component configured to convert light energy of a first light signal into a first photocurrent and then to provide the first photocurrent to a capacitor to charge the capacitor to a first voltage;
a voltage reversing circuit connected to the capacitor and configured to reverse the first voltage to form a reverse voltage;
a comparator, wherein a first input terminal of the comparator is connected to the capacitor, a second input terminal of the comparator is coupled to a reference voltage, and the comparator is configured to compare the first voltage with the reference voltage to output a first comparing signal; and
a counter, wherein an input terminal of the counter is connected to an output terminal of the comparator, and the counter is configured to count a first coarse count value according to the first comparing signal;
wherein, after the first coarse count value is counted, the photoelectric component converts light energy of a second light signal into a second photocurrent and provides the second photocurrent to the capacitor to charge the capacitor to a second voltage from the reverse voltage;
wherein, the comparator compares the second voltage with the reference voltage to output a second comparing signal, and the counter counts a second coarse count value according to the second comparing signal;
wherein, after the second coarse count value is counted, the counter performs a fine counting operation on the second coarse count value to count a fine count value;
wherein, one of the first light signal and the second light signal is a light signal that is emitted by both of a light-emitting component and an ambient light source and then is reflected by a tested object, and the other one of the first light signal and the second light signal is a light signal that is emitted by only the ambient light source.