Patent ID: 8276434

Claim:
A mobile device comprising: an acceleration detecting portion to detect accelerations in three directions different from each other; a gravity direction detecting portion to detect a gravity direction on the basis of said detected accelerations in the three directions; a gravity direction acceleration calculating portion to calculate an acceleration in said detected gravity direction on the basis of said detected accelerations in the three directions; a vibration generating portion to generate vibration by rotating about a predetermined rotational axis; and a step counting portion to count the number of steps on the basis of said calculated gravity direction acceleration, wherein said step counting portion includes a correcting portion to correct said calculated gravity direction acceleration with an acceleration generated by said vibration generating portion while said vibration generating portion is rotating, and a counting portion to count the number of instances where said corrected acceleration takes a value of not smaller than a threshold value or the number of instances where said corrected acceleration takes a value of not greater than a threshold value.