ALPS has developed the industry's first hinge-mounted* position detection switch for miniature mobile devices, the miniaturized SREF series. Mounted within the hinge, this device detects the position of the cover of a folding device. Samples will ship in the second half of September.

Until now, position detectors for PDAs, notebook PCs, and other miniature mobile devices with folding covers were one of two types. One type was located in a boss on the exterior surface of the product, such that movement of the stem of the detection switch within the boss allowed detection of the cover's position. The other type used a Hall IC to magnetically detect the cover's position. When the boss-type media detection switch is used, space must be left on the motherboard for mounting of the media detection switch, and there must be a boss on the exterior of the product as well as room for the plunger to move. This imposes design constraints, which has been an issue. The Hall IC position detector also requires space on the motherboard, as well as standby power. In addition, they can interfere with geomagnetic sensors used in global positioning systems, which are forecast to grow in popularity.

The SREF series are rotary-type position detection switches that are built into device-cover hinges, and therefore directly detect cover position angles. Movement of the hinge simultaneously moves the detector's traveling contact, which at a preset angle makes contact with the fixed contact. The development of this series makes possible the design of products that incorporate various compact mechanisms. Together with this, a new miniature traveling contact was developed using ALPS' proprietary microfabrication technology, with external dimensions of 5× 1.9mm.

This miniaturization makes it possible to incorporate the sensor directly into the hinges of various mobile devices. This conserves space on the motherboard, which in turn contributes to the miniaturization of mobile devices. It also eliminates the need for the external boss required for the earlier pressure-type detection switches, increasing freedom of design for component manufacturers.

Because the SREF series do not use magnetism, there is no issue of interference with geomagnetic sensors for global positioning systems, as there is with Hall IC type switches. In addition, because it is a contact-type switch, it only draws current when contact is made, which reduces power consumption.

These switches can be customized for various applications by setting the angle of detection, or setting multiple detection angles.