Patent ID: 7743345

Claim:
A display system, comprising: a touch panel that simultaneously displays a first key group and a second key group, the second key group including a product key and a first switching key, the first switching key switching a display to replace the second key group with a third key group on one display; a display switching unit that, in response to a pressed the first switching key, replaces the second key group with the third key group on the display of the touch panel so that the first key group and the third key group are simultaneously displayed; a key group master memory unit that stores key group master information for the first, the second, and the third key groups; a displayed key group attribute information storage unit, that stores, as displayed key group attribute information, the key group master information of the first, the second, and the third key groups that are being displayed on the display of the touch panel; and a operation key attribute obtaining unit that, in response to the pressed first switching key, obtains a link destination attribute and a link destination number in the displayed key group attribute information that corresponds to the first switching key, and outputs the link destination attribute and the link destination number to the display switching unit; wherein the display switching unit that, in response to receiving the link destination attribute and the link destination number from the operation key attribute obtaining unit, reads out from the key group master memory unit, the key group master information designated according to a received link destination attribute and a received link destination number in the displayed key group attribute information that corresponds to the pressed first switching key, and replaces only the second key group with the third key group corresponding to the key group master information designated according to the link destination attribute and the link destination number for display on the touch panel, and updates the displayed key group attribute information by replacing only the key group master information of the second key group with the third key group.