1. A dynamic range three-dimensional image system, comprising: an optical detector including a gain control terminal capable of controlling an optical amplification gain; a pixel detecting module for detecting a pixel signal for configuring an image by receiving an output of the optical detector; a high dynamic range (HDR) generating module for acquiring a dynamic range image by generating a signal indicating a saturation degree of the pixel signal and combining the pixel signal based on the pixel signal detected by the pixel detecting module; and a gain control signal generating module using the signal, as an input, indicating the saturation degree of the pixel signal and generating a voltage, as an output, which is more than a steady value for supplying the voltage to the gain control terminal of the optical detector, wherein the voltage is a value of adding a voltage which is in proportion to a reciprocal number of the signal indicating the saturation degree of the pixel signal to a punch-through voltage, and wherein the gain control signal generating module controls the optical detector including the gain control terminal.