| 摘要 |
PURPOSE:To eliminate a mounting or timing error caused by two detectors and to attain high-precion detection by detecting beginning and finishing ends of a magnetic head by one detector. CONSTITUTION:The beginning and finishing ends detector 30 is composed of a linear motor 24, reading head 23, shutter 13 and the first and second detectors 12 etc. The first and second sensors 11, 12 are made up of opposing light emitting and photodetecting elements. A shutter 13 passes through the space between the light emitting and photodetecting elements to turn the output ON and OFF by light penetrating or shielding. In such a manner, when the first sensor 11 is OFF, the read head 23 is positioned in the range of the information area 10. When the output of the first sensor 11 is changed between ON and OFF, that the read head 23 is positioned at a beginning end 8 or at a finishing end is detected.
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