Registers – Coded record sensors – Particular sensor structure
Patent
1997-08-28
1999-07-20
Hajec, Donald
Registers
Coded record sensors
Particular sensor structure
235462, G06K 710
Patent
active
059258683
ABSTRACT:
A method and apparatus for determining the transitions between binary levels of an input signal such as a scanned bar code label by detecting zero crossings of an approximated second derivative of the input signal. Samples of the input signal are obtained by using delay lines, sample-and-hold circuits, an analog shift register or similar device. The first derivative of the signal is approximated by the slope of a straight line between two sampled points on the waveform. The second derivative is approximated by the difference between two first derivatives. Zero crossings of the second derivative indicating transitions of the input signal may be determined either by detecting a signal peak on both sides of the zero crossing, or by comparing the second derivative signal to zero when the first derivative exceeds a positive or negative threshold. The amount of shift in the zero crossings may be estimated by measuring relative amplitudes or widths of the surrounding signal lobes. The time between sample points may be adjusted to match a particular range setting of a scanner having a plurality of range settings.
REFERENCES:
patent: 3610934 (1971-10-01), Turner
patent: 4000397 (1976-12-01), Hebert et al.
patent: 4135161 (1979-01-01), Torrieri
patent: 4427296 (1984-01-01), Demareste et al.
patent: 4697098 (1987-09-01), Cloke
patent: 4733064 (1988-03-01), Ishikawa
patent: 4740675 (1988-04-01), Brosnan et al.
patent: 4749879 (1988-06-01), Peterson et al.
patent: 4825055 (1989-04-01), Pollock
patent: 4853802 (1989-08-01), Kukson et al.
patent: 5103080 (1992-04-01), Barkan et al.
patent: 5103209 (1992-04-01), Lizzi et al.
patent: 5121009 (1992-06-01), Braathen
patent: 5192856 (1993-03-01), Schaham
patent: 5210397 (1993-05-01), Eastman
patent: 5272323 (1993-12-01), Martino
patent: 5304854 (1994-04-01), Aoki et al.
patent: 5347121 (1994-09-01), Rudeen
patent: 5365049 (1994-11-01), Peng
patent: 5371361 (1994-12-01), Arends et al.
patent: 5408081 (1995-04-01), Barkan
patent: 5446272 (1995-08-01), Barkan
patent: 5449893 (1995-09-01), Bridgelall et al.
patent: 5506411 (1996-04-01), Tasaki
patent: 5545888 (1996-08-01), Barkan et al.
patent: 5574272 (1996-11-01), Seo et al.
patent: 5581072 (1996-12-01), Bridgelall et al.
patent: 5608201 (1997-03-01), Coleman, Jr.
patent: 5619028 (1997-04-01), Barkan
Hamming, R.W., Numerical Methods for Scientists and Engineers (2d Ed. 1973), pp. 599-601.
Williams, Arthur, Filter Design Handbook (1981), pp. 2-55 to 2-58, 2-60, 2-64, 2-67 to 2-68, 3-15 to 3-19, 7-14 to 7-15, 7-19 to 7-20, 12-58 and 12-67.
Arends Thomas C.
Elliott Randy D.
Hajec Donald
Rodriguez Douglas X.
Spectra-Physics Scanning Systems, Inc.
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