Patent ID: 7406871

Claim:
A fuel type identifying apparatus comprising: a quantity detector, which detects a plurality of physical or chemical quantities, from a liquid fuel, depending on a physical or chemical property of the liquid fuel, and outputs a detection signal indicating the physical or chemical quantities; and an identifying unit, which receives the detection signal from the quantity detector and identifies a type of the liquid fuel according to the physical or chemical quantities of the detection signal; and a data storage that stores a plurality of referential physical or chemical quantifies for each of a plurality of types of referential liquid fuels, the referential physical or chemical quantities for the referential liquid fuel of each of the types being obtained by outputting a first signal indicating a plurality of predetermined quantities to the referential liquid fuel to obtain a second signal from the referential liquid fuel, measuring a plurality of physical or chemical quantities of the second signal, and setting the measured physical or chemical quantities as the referential physical or chemical quantities, wherein the quantity detector comprises: a signal transmitter, which produces an investigation signal indicating plurality of predetermined quantities that are changeable in response to the physical or chemical properties of the liquid fuel and outputs the investigation signal to the liquid fuel to induce the liquid fuel to change the predetermined quantities to the physical or chemical quantities; and a signal receiver that receives the physical or chemical quantities as the detection signal from the liquid fuel, wherein the identifying unit collates the physical or chemical quantities of the detection signal with the physical or chemical referential quantities of each type of referential liquid fuel stored in the data storage to obtain a plurality of collation results and identifies the type of the liquid fuel according to the collation results.