Patent ID: 8649057

Claim:
An operation apparatus comprising: a touch panel that can display a setting item window displaying a plurality of setting item keys and a setting condition input window accepting input of a setting condition for a setting item corresponding to each of the plurality of setting item keys and detect an input operation to the plurality of setting item keys; a determination unit that determines whether an input operation on the plurality of setting item keys is detected within a predetermined time period by the touch panel; a shrinkage rate calculating unit that calculates, in a case in which the determination unit determines that an input operation on the plurality of setting item keys is detected within a predetermined time period, a shrinkage rate allowing equal allocation of space for a predetermined number, which is at least a setting item number, which is the number of setting item keys on which the input operation is detected, of setting condition input windows in a display region based on the setting item number, and a size of the display region in a case of displaying only one setting condition input window on the touch panel; a window shrinking unit that shrinks a predetermined number of setting condition input windows among the setting condition input windows for accepting an input of a setting condition for the setting item corresponding to the setting item keys on which the input operation is detected, based on the shrinkage rate calculated by the shrinkage rate calculating unit; and a multi window display unit that displays in the display region the predetermined number of setting condition input windows that are shrunk by the window shrinking unit.