Some mobile phones and information terminal devices in widespread use today include a fixed-side case having an operation section such as keys and a movable-side case having a display section such as a display panel. The movable-side case is connected to the fixed-side case with a connection mechanism, so that the movable-side case can be rotated and slid relative to the fixed-side case. In a slide-type mobile phone, the movable-side case can be slid relative to the fixed-side case between a closed state and an open state, so that, for example, the mobile phone is made compact. In a rotation-type mobile phone, the movable-side case can be rotated relative to the fixed-side case so that, for example, the viewability of the display section is improved.
In existing information terminal devices, the fixed-side case and the movable-side case are made as separate bodies, and a circuit board disposed in the fixed-side case and a circuit board disposed in the movable-side case are electrically connected to each other. For the electrical connection, an electric wiring line having a comparatively high flexibility, such as a flexible printed circuit (FPC), is usually used.
[Patent Document 1] Japanese Laid-Open Patent Publication No. 2008-103989
However, the existing information terminal devices have a problem in that the electric wiring line, such as an FPC, has a low stowability. That is, in the information terminal devices, the FPC has a bent portion that is bent in accordance with the amount of relative movement of the movable-side case and the fixed-side case, so that the movable-side case can be movably connected to the fixed-side case. In order to provide the FPC having a strip shape with the bent portion, the FPC is bent in the thickness direction and then laminated. Therefore, the laminated FPC occupies a large space in the thickness direction, which makes it difficult to make a low-profile device.
If the FPC is forcedly bent in a small space, the FPC may be curved, buckled, or twisted owing to a load that is generated due to repeated movement of the movable-side case, which may lead to breakage of the FPC. If the information terminal device is a rotation-type mobile phone and a strip-shaped FPC is used as the electric wiring line, it is very likely that a breakage may occur because the FPC has an extremely low durability against twisting.