Title:
DISPLAY UNIT FOR TAPE RUN TIME
Document Type and Number:
Japanese Patent JPS5564677
Kind Code:
A
Abstract:
PURPOSE:To calculate and display the tape remaining time with excellent precision by providing a counter measuring method which detects rotation angular speed ratios of a supply reel and take-up reel and an arithmetic method which obtains the qunatity of a remaining tape. CONSTITUTION:Disk 1 connected direct to take-up reel A or supply reel B is provided with the (k)-number slits 1a at equal angular intervals, and light from light emitting diode 8 is detected by photo transistor 9. Through an arithmetic process of a pulse signal generated at every 1/k rotation, the tape run time or tape remaining time is displayed. A ratio of the count number between both reels is angular speed ratio (beta) between both reel as it is and the tape remaining time can be found as the function of this angular speed ratio (beta). In this constitution, the tape remaining time can be calculated and displayed as time with accuracy not as the rotational frequency of the reel.
Inventors:
YAMADA MASAMICHI
Application Number:
JP13788978A
Publication Date:
May 15, 1980
Filing Date:
November 10, 1978
Export Citation:
Assignee:
HITACHI LTD
International Classes:
G11B27/17; (IPC1-7): G11B27/14