Fitzpatrick, Cella, Harper & Scinto
Key input device
 A key input device is arranged such that a transparent keyboard is placed on a display unit for displaying characters and numerals so as to perform display and key input operations. Transparent electrodes are formed on the inner walls of a plurality of transparent sheets in the keyboard, and transparent projecting members as spacers are formed on one of the inner walls so as to prevent key input errors. The projecting members are constituted by transparent semispherical members formed on the inner wall of the transparent sheet disposed away from the light incident side, thereby improving readability of the displayed content on the display unit. 
Canon Kabushiki Kaisha
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Kazuhiro
Arakawa