Patent ID: 7167390

Claim:
A storage device comprising a memory element and an applying unit for applying a voltage to said memory element wherein said memory element changes its characteristic to record thereon new information with application of said voltage to said memory element by said applying unit, said memory element further changing its characteristic when the same information is recorded on said memory element continuously, said storage device having a recording method which comprises the steps of: detecting content of old information that has already been recorded on said memory element when said new information is recorded; comparing said old information that has already been recorded on said memory element with said new information to be recorded on said memory element; applying said voltage to said memory element to make an ordinary information recording process if said new and old information are different from each other; and disabling said ordinary information recording process when said old and new information are identical to each other, wherein said recording method further comprises the steps of further determining whether or not the resistance value of said memory element falls within a range of a normalized value if said two information are identical to each other and applying said voltage to said memory element by said applying unit to correct said resistance value so that said resistance value falls within the range of said normalized value if said resistance value does not fall within the range of said normalized value.