Patent ID: 9237333
Filing Date: 2016-01-12
CPC Classification: G01S,H04N

Claim Text:
1. An apparatus for measuring depth information, the apparatus comprising: a log converting unit configured to receive a light reflected from an object, and to output a log node voltage that is proportional to a log value of an intensity of the reflected light; a comparison outputting unit connected to an output of the log converting unit, and configured to output a comparison node voltage of a second threshold value when the log node voltage increases by at least a first threshold value after activation of a first control signal, wherein the comparison outputting unit comprises: a comparator with a first input port and a second input port, the second input port being connected to an input port of the comparison outputting unit; a buffer connected to the first input port of the comparator; and a first switch disposed between the buffer and the input port of the comparison outputting unit, wherein the first switch operates based on the first control signal, and wherein the comparator outputs a comparison node voltage substantially equal to the second threshold value when a voltage of a second input port of the comparator is at least the first threshold value greater than a voltage of the first input port; and at least one discharging unit connected to an output of the comparison outputting unit and configured to discharge, based on a predetermined rule, an output node voltage until a second control signal is activated when the output of the comparison outputting unit is equal to or greater than the second threshold value, wherein the output node voltage is charged, in advance, to a level of a source voltage, wherein the second control signal is activated when the discharging is performed during a predetermined time, and wherein each of the at least one discharging unit discharges the corresponding output node voltage at a different rate.