Browse Prior Art Database

Detection of Power Frequency for Moving a Document Table

IP.com Disclosure Number: IPCOM000043572D
Original Publication Date: 1984-Sep-01
Included in the Prior Art Database: 2005-Feb-05
Document File: 2 page(s) / 59K

Publishing Venue

IBM

Related People

Yanagisawa, H: AUTHOR

Abstract

The frequency of AC power applied to an AC synchronous motor for moving a document table is detected by counting pel (picture element) lines in a predetermined distance. Fig. 1 shows scanning apparatus 1 in which the document table 2 is reciprocally moved by the AC synchronous motor 3 through rack and pinion mechanism 4. The document table 2 is provided with document glass 5 and control marks 6 and 7. The marks 6 and 7 are printed on the backsurface of the document table 2. The mark and document, face down on the document glass 5, are moved relative to optical slit 8 of an optical scan system including a light source (not shown), mirror 9, lens 10 and CCD (charge-coupled device) sensor array 11. The AC synchronous motor 3 is driven by 50 Hz or 60 Hz. Fig. 2 shows the cycle time or CCD charge integration time period.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 83% of the total text.

Page 1 of 2

Detection of Power Frequency for Moving a Document Table

The frequency of AC power applied to an AC synchronous motor for moving a document table is detected by counting pel (picture element) lines in a predetermined distance. Fig. 1 shows scanning apparatus 1 in which the document table 2 is reciprocally moved by the AC synchronous motor 3 through rack and pinion mechanism 4. The document table 2 is provided with document glass 5 and control marks 6 and 7. The marks 6 and 7 are printed on the backsurface of the document table 2. The mark and document, face down on the document glass 5, are moved relative to optical slit 8 of an optical scan system including a light source (not shown), mirror 9, lens 10 and CCD (charge- coupled device) sensor array 11. The AC synchronous motor 3 is driven by 50 Hz or 60 Hz. Fig. 2 shows the cycle time or CCD charge integration time period. 10 msec. is settled for 50 Hz power, and 8.3 msec. is settled for 60 Hz power. One of the cycle times, i.e., 10 msec. or 8.3 msec., is selected depending upon which AC power is supplied. To detect the frequency of the AC power, the marks 6 and 7 with known distance x, e.g., 62.5 mm, are provided, and the number of pel lines scanned by the optical scan system from the left edge of the mark 6 to the left edge of the mark 7 are counted by an image capture control circuit (not shown). If the number of pel lines per 1 mm is 8, the total pel lines for the distance 6.25 mm are; 500 pel lines ( = 62.5...