Patent ID: 8665352

Claim:
A method of acquiring physical information by using a semiconductor device, the semiconductor device including unit elements, each unit element having a unit signal generating unit outputting the unit signal through an output signal line on the basis of the variation in the physical quantity, the method comprising: providing an operation current supply unit that supplies an operation current such that the unit signal generating unit outputs the unit signal, and a signal processing unit that receives the unit signal output from each of the unit elements forming the semiconductor device and outputs an output unit signal based on the unit signal at a predetermined timing; and when a selective read mode is designated in which the unit signal is read from a portion of the respective unit elements forming the semiconductor device, reducing an operation current of the output signal line of the unit signal generating unit not to be read so as to be smaller than an operation current of the output signal line of the unit signal generating unit to be read, and further wherein a load control unit simultaneously turns off a plurality of signal lines of columns that are not to be read via selectively controlling switches for rows that are switched off, and wherein load transistors selectively provide a read signal thereby reducing power consumption, and further wherein the operating current of signal lines that are not read are reduced with respect to an operating current of signal lines that are read, and the load transistors for the signal lines that are read form source follower circuits in combination with an amplifying transistor for a selected row and a load control signal from the load control unit is applied to the vertical signal line such that a predetermined constant current flows through each vertical signal line of each read subject via load transistors connected to each amplifying transistor and a small amount of current flows through vertical signal lines other than those being read, the load transistor thereby selectively forming a source follower together with an amplifying transistor of a selected row and supplying a read current of a magnitude necessary for pixel signal reading to the amplifying transistor.