In recent years, electronic presentations have been made using multiple display devices (e.g., monitors, etc.). In such cases, an operator giving the presentation connects an external display device, such as an external monitor or projector for an electronic device, such as a laptop personal computer (PC) carried by the operator and causes an external output device to display the screen content of the laptop PC by operating the laptop PC in, for example, a mirror display mode.
In some conventional electronic devices, such as computer equipment, an operating system for a multi-monitor system can be used to connect two or more display devices to one terminal so that the display devices can be used on the same system in case one display device is separated, which can be intended by a user. For example, Japanese Patent Application Publication No. 2004-62177 describes a multi-monitor display in which a small-screen display device is disposed on a side or upper surface of a large-screen display device so that the display screens of these display devices are driven by the same operating system.
In a case in which a multi-monitor setting of the laptop PC is the mirror display mode, for example, the screen content of the laptop PC can be unintentionally displayed on the external display device immediately after the external display device is connected to the laptop PC. Since screen contents of the laptop PC may include content that the operator does not want to be displayed on the external display device, the operator generally wants to quickly switch out of the multi-display mode. This switching operation, however, usually involves pressing a special key or the like, and is not currently known to users. Operation of a special key, in some cases, involves pressing an operation function key “Fn” as a special key and an F-number key (e.g., “F7 ”) at the same time, and this pressing causes the multi-display mode to switch OFF.
Even when the multi-display mode switches OFF by operating the special key, if the mirror display mode has been selected, the display content of the laptop PC can be displayed on the external display device at least for a moment, and a screen content not intended by the operator is displayed on the external display device.