| 摘要 |
PURPOSE:To attain a cordless system, by converting an electric signal obtained at a light pen main body into magnetic flux with a winding on a light pen main body and detecting the magnetic flux with a winding built in a CRT display device through electromagnetic induction coupling. CONSTITUTION:A light pen 4 takes in a light signal from a CRT screen 2 of a CRT display device 1 displaying the information of electronic computer and the like, converts the signal into an electric signal at a photoelectric signal converting circuit 5 and applies the said electric signal to a winding 6 of the light pen. The magnetic flux generated in the winding 6 is detected in a winding 3 incorporated in a CRT frame and a voltage is induced in the said winding. The induced voltage signal is converted into a signal in the form to be easily fetched to an information processor 8 at a signal reproducing circuit 7 and given to the processor 8. Through this system, none of electric conductor and optical fiber is required, no open wire fault takes place and the operability of the light pen can be improved. |
