Abstract: It is provided an authentication system comprising: an input device; an image pickup device for picking up an image of the living body; an image processing unit for processing the image picked up by the image pickup device; a storage device for storing a plurality of pieces of first feature data and a plurality of pieces of second feature data; and a matching processing unit for checking input data, which indicates features of a living body picked up by the image pickup device, against each of the plurality of pieces of first feature data and each of the plurality of pieces of second feature data. Each of the plurality of pieces of second feature data is data that is smaller in size than each of the plurality of pieces of first feature data and that includes at least a part of the features of the living body.

Abstract: A primary object of the present invention is to extract a difference in shading of a blood vessel image in a picked up image as information to be used for authentication, and to acquire a larger number of pieces of biometric information from one image. An individual authentication device to be used to authenticate an individual using feature information of a vascular pattern acquired from a living body includes an imaging unit that images a region of the living body serving as an object of authentication, and an arithmetic unit that acquires the picked up image as an authentication image. The arithmetic unit extracts a vascular pattern from the authentication image, and acquires a degree of shading of the vascular pattern as the feature information.

Abstract: Respective positive terminal electric potentials of exhaust gas sensors are sequentially selectively inputted to an analog input terminal of a multi-channel AD converter through a multiplexer. An offset voltage is applied to respective negative terminals of the exhaust gas sensors. This offset voltage is inputted to another input terminal of the multi-channel AD converter. A microprocessor detects a generating voltage of the exhaust gas sensors by the difference between a digital converting value of the positive terminal electric potential and a digital converting value of the negative terminal electric potential. The microprocessor also individually judges that each of the digital converting values is excessively small and excessively large. Thus, the microprocessor judges the existence of ground, sky short circuit and disconnection abnormalities of the negative terminal and the positive terminal.

Abstract: Respective positive terminal electric potentials of exhaust gas sensors are sequentially selectively inputted to an analog input terminal of a multi-channel AD converter through a multiplexer. An offset voltage is applied to respective negative terminals of the exhaust gas sensors. This offset voltage is inputted to another input terminal of the multi-channel AD converter. A microprocessor detects a generating voltage of the exhaust gas sensors by the difference between a digital converting value of the positive terminal electric potential and a digital converting value of the negative terminal electric potential. The microprocessor also individually judges that each of the digital converting values is excessively small and excessively large. Thus, the microprocessor judges the existence of ground, sky short circuit and disconnection abnormalities of the negative terminal and the positive terminal.