| 摘要 |
PURPOSE:To eliminate a mobile contact part and to improve reliability of a keyboard, by using a solar battery as an input detecting element of each key of the keyboard, and performing input by touching the key with a finger to cut off the light. CONSTITUTION:When an optional key is pushed by a finger, a solar battery 9a on the rear side is covered with the finger. Thus only the battery 9a is cut off, and therefore the electromotive force of said battery goes to zero. Usually, a keyboard is operated under such brightness that can confirm the operation of keys 9, and therefore the keyboard has some electromotive force unless the keyboard itself is shielded from light. Under such conditions, if only the battery 9a is shielded from light, the electromotive force is set at zero. Thus an LSI13 discriminates the pushed key and processes the push as an input. In this case, other keys 9 than the desired one is shielded from light by the finger. However this shielding of light causes just half shadow, and it is possible for the LSI13 to decide correctly only the desired key 9. |
