To ensure detection by a sensor circuit of changes in electrostatic capacitance by heightening the detection sensitivity of a sensor electrode, making it possible to process the user's input operation stably.
A reflector plate 4B is disposed beneath a light guide plate 4A to prevent light from leaking to the bottom of the light guide plate 4A. An FPC 3 has a through hole 7 formed at a position opposite to the position of an icon 6 printed on a surface panel 5. From the through hole 7 does light emitted from an LED 4C to an upper part via the light guide plate 4A pass therethrough, making it possible to illuminates the icon 6. A sensor electrode 2 consists of a detection electrode and a GND electrode. Between the FPC 3 and the surface panel 5 is disposed a layer of adhesive 8 whose dielectric constant is higher than that of an air layer having the same cubic volume, whereby an electrostatic capacitance type touch sensor 1 is fixed to the surface panel 5 and also the detection sensitivity of the sensor electrode 2 is heightened. The adhesive 8 is disposed in such a way as to avoid covering the through hole 7 of the FPC 3.
Ryuichiro Mori
Naoki Matsuo