Patent ID: 8336096

Claim:
An access control apparatus comprising: a memory section that stores information; an authentication information memory section that stores at least one of first stored user authentication information and second stored user authentication information corresponding to a user, the first stored user authentication information including a predetermined access time period; an input section in which first inputted user authentication information and second input user authentication information are inputted; a judgment section that judges whether the first inputted user authentication information matches the first stored user authentication information; a registration section that stores the second inputted user authentication information in the authentication information memory section, if the judgment section judges that the first inputted user authentication information matches the first stored user authentication information; an approval section that approves access to the information stored in the memory section for the predetermined access time period if the judgment section judges that: (1) the first inputted user authentication information mates the first stored user authentication information, and (2) the second inputted user authentication information matches the second stored user authentication information; and an automated removal section that automatically removes the second stored user authentication information and the predetermined access time period form the authentication information memory section if a current period is later than the predetermined access time period; wherein the predetermined access time period is a time period specified in the first stored authentication information, and specifies a duration for allowing the user access to in the information stored in the memory section; the first stored user authentication information corresponds to a first user; the second stored user authentication information corresponds to a second user distinct from the first user; and the registration section causing each of a plurality of authentication information to get stored in authentication information memory section as the second authentication information if the plurality of the authentication information is inputted into the input section during the predetermined access time period before or after a point in time at which authentication information agreeing with the first stored user authentication information is inputted.