Patent ID: 8823957

Claim:
An operation device comprising: a touch panel that has a touch sensor disposed on a top surface side for detecting contact of a contact object, and a display unit for displaying a screen, the touch panel configured to enable selection of a key contained in the screen; a function screen display reception unit configured to cause the touch panel to display the screen including a screen area for displaying a first function screen related to a first function and a second function screen related to a second function, and a retreat area being different from the screen area; an operation unit for receiving an operation from an external unit; a screen switching reception unit configured to cause the touch panel to display an icon key symbolizing the second function of the second function screen in a selectable configuration at a predetermined position of the retreat area so as to notify in advance a user of switching display for the screen area being on standby when the first function screen is displayed in the screen area and an instruction is received from the user through the operation unit to switch from the first function screen to the second function screen; a reduced screen display reception unit configured to cause the touch panel to display a first reduced screen key representative of a reduced image of the first function screen in a selectable configuration in the retreat area when the icon key is manipulated by the user on the touch panel; and a function screen switching unit for switching from the first function screen to the second function screen in the screen area when the first reduced screen key is displayed in the retreat area.