US Patent 7423246 Analysis apparatus and analysis disc used for the same

It is an object of the present invention to provide an analysis apparatus which can achieve an image with a proper contrast even from an analysis object on an analysis optical disc. When an image is obtained from an analysis object 111, a control unit (210) switches a switch (208) in such a way that a detection signal of laser light has a constant average value, the laser light having been emitted to the analysis optical disc and reflected thereon or passed therethrough, and the control unit (210) feeds back the output signal of an integrating circuit (209) to an APC circuit (115) for controlling a laser drive circuit (116).