Patent ID: 7698092

Claim:
A portable electronic apparatus comprising: a content storage unit configured to store content data; a display unit configured to display a screen showing at least a title of a content data stored in the content storage unit; an acceleration detection unit configured to detect an acceleration from a movement of the whole said portable electronic apparatus, the acceleration unit configured to detect the acceleration on the basis of detecting a movement of the portable electronic apparatus in a direction perpendicular to the screen and a movement of the portable electronic apparatus in a direction parallel to the screen; an evaluation-signal generation unit configured to perform a predetermined process based on said acceleration detected by said acceleration detection unit in order to generate an evaluation signal representing an amplitude and positive or negative polarity of said acceleration; and a control unit configured to produce a result of determination as to whether said portable electronic apparatus has been driven to make a predetermined movement on the basis of a vacillating acceleration force indicated by said evaluation signal, and perform a predetermined operation on the basis of said result of determination, wherein said evaluation-signal generation unit generates said evaluation signal by: computing at least one present absolute value of an acceleration value detected by said acceleration detection unit at a present point of time, computing previous absolute values of acceleration values detected by said acceleration detection unit at respective points of time during a predetermined period of time preceding the present point of time, and finding an average of said previous absolute values, and subtracting said average from said at least one present absolute value of the present acceleration in order to give a value of said evaluation signal at said present point of time.