Abstract: An electronic device includes: a memory storing a first lock release code; a comparing portion comparing the first lock release code with a second lock release code that is input with an input device; a controlling portion releasing a lock if the comparing portion finds that the first lock release code matches the second lock release code, and permitting the electronic device to operate normally; and a lock release portion releasing the lock, even if the comparing portion finds that the first lock release code does not match the second lock release code, or no code input is made, when a first predetermined time elapses from a predetermined time point.

Abstract: An electronic device includes a memory storing a first lock release code, a comparing portion comparing the first lock release code with a second lock release code that is input with an input device, a controlling portion permitting the electronic device to operate normally if the comparing portion finds that the first lock release code matches the second lock release code, and a restricting portion restricting an acceptance of an input of the second lock release code after input attempts have been made a predetermined number of times if the comparing portion finds that the first lock release code does not match the second lock release code.

Abstract: An electronic device includes a first rewritable nonvolatile memory storing a first lock release code, a comparing portion comparing the first lock release code with a second lock release code that is input with an input device, a controlling portion permitting the electronic device to operate normally if the comparing portion finds that the first lock release code matches the second lock release code, and a first error checking portion checking whether or not there is an error in the first lock release code stored in the first rewritable nonvolatile memory. If the first error checking portion finds an error in the first lock release code stored in the first rewritable nonvolatile memory, the controlling portion permits the electronic device to operate normally regardless of a comparison result obtained by the comparing portion.