Patent ID: 8854320

Claim:
A portable image display device, comprising: a display screen having a substantially rectangular shape; a plurality of touch sensors provided along at least two sides defining a circumference of the display screen, wherein each of the touch sensors is configured to detect a position touched by a finger of a user; and a control section for changing an image displayed on the display screen in accordance with a combination of the positions of a plurality of the fingers which are respectively detected by the plurality of touch sensors; wherein the control section acquires one or more coordinate value sequences, which include coordinate values indicating the positions detected at predetermined time intervals, from each of the plurality of touch sensors; wherein the control section calculates an index value for each of the one or more coordinate value sequences, wherein each index value indicates a probability that its corresponding coordinate value sequence is generated by an operation input of the user; and wherein the control section determines whether or not each of the one or more coordinate value sequences corresponds to a predetermined operation pattern based at least in part on the calculated index values.