Patent US5436440A successfully refreshed from Google Patents.
US5436440A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Digitizing circuit for a laser scanner using digital and synchronizing signals
Assignee: Symbol Technologies LLC
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Filing: 1994-05-11
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Granted: 1995-07-25
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Expires: 2014-05-11
Abstract
Abstract A trigger-operated or triggerless scanner reads symbols with a first scan pattern in a first intended position of hand-held use. Either scanner may be mounted on a stand-alone fixture wherein the first scan pattern is converted to a second, different scan pattern, again for reading indicia in a second intended position of workstation use. Various signal processing digitizing circuits for faithful digital reconstruction of the symbols are disclosed.
Inventors
- 👤 Edward Barkan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 06:11
CPC Classifications
G; G06; G06K; G06K7/00; G06K7/10; G06K7/10544; G06K7/10821; G06K7/10861; G06K7/10871; G06K7/10554; G06K7/10564; G06K7/10584; G06K7/10594; G06K7/10603; G06K7/10633; G06K7/10643; G06K7/10653; G06K7/10673; G06K7/10683; G06K7/10693; G06K7/10792; G06K7/10801; G06K7/10811; G06K7/10851; G06K7/10881; G06K7/10891; G06K7/109; G06K7/14; G06K7/1404; G06K7/146; G06K7/1478; G06K2207/00; G06K2207/1011; G06K2207/1016; G06K2207/1018
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
117 words
A circuit for digitizing an analog electric signal generated from a photoelectronic conversion of light reflected off from scanning indicia having spatially-separated, light-reflective portions, comprising: first differentiating means for differentiating the analog electric signal to generate a first differentiated signal; means for receiving the first differentiated signal and generating a synchronizing signal corresponding to transitions in the spatially-separated, light-reflective portions of the indicia; means for generating a first digital signal having transitions corresponding to the transitions of the spatially-separated, light-reflective portions of the indicia; and output means for receiving the synchronizing signal and the digital signal to produce a digital output signal having transitions corresponding to the transitions of the spatially-separated, light-reflective portions of the scanning indicia.
Claim 2
Dependent Claim
117 words
A circuit for digitizing an analog electric signal generated from a photoelectronic conversion of light reflected off from scanning indicia having spatially-separated, light-reflective portions, comprising: first differentiating means for differentiating the analog electric signal to generate a first differentiated signal; means for receiving the first differentiated signal and generating a synchronizing signal corresponding to transitions in the spatially-separated, light-reflective portions of the indicia; means for generating a first digital signal having transitions corresponding to the transitions of the spatially-separated, light-reflective portions of the indicia; and output means for receiving the synchronizing signal and the digital signal to produce a digital output signal having transitions corresponding to the transitions of the spatially-separated, light-reflective portions of the scanning indicia.
Claim 3
Dependent Claim
73 words
A circuit for digitizing an analog electric signal according to claim 1, wherein the means for generating the synchronizing signal comprises: means for shifting the first differentiated signal by a predetermined amount to generate a shifted signal; comparator means for comparing the first differentiated signal and the shifted signal to generate a comparator output signal; and means for receiving the comparator output signal and generating the synchronizing signal from the indicia being scanned.
Claim 4
Dependent Claim
31 words
A circuit for digitizing an analog electric signal according to claim 2, wherein the comparator output signal has transitions at each intersection between the first differentiated signal and the shifted signal.
Claim 5
Dependent Claim
48 words
A circuit for digitizing an analog electric signal according to claim 3, wherein the means for receiving the comparator output signal includes a logic gate for receiving the comparator output signal and generating, as the synchronizing signal, a pulse signal at the transitions of the comparator output signal.
Claim 6
Dependent Claim
127 words
A circuit for digitizing an analog electric signal according to claim 1, wherein the means for generating the first digital signal comprises: means for inverting the first differentiated signal and generating an inverted signal; a first peak detector, responsive to the inverted signal and the first differentiated signal, for generating a first peak signal; means for reducing the first peak signal to a predetermined level to generate a first reduced peak signal; means for comparing the first reduced peak signal to the inverted signal and generating a second digital signal; means for comparing the first reduced peak signal to the first differentiated signal and generating a third digital signal; and a logic circuit, responsive to the second and third digital signals, for producing the first digital signal.
Claim 7
Dependent Claim
30 words
A circuit for digitizing an analog electric signal according to claim 5, wherein the predetermined level is set to prevent noise signals from affecting the first and second digital signals.
Claim 8
Dependent Claim
100 words
A circuit for digitizing an analog electric signal according to claim 5, further comprising a threshold circuit for resetting the output means after each scanning, the threshold circuit comprising: a peak detector for detecting peaks of one of the inverted signal and the first differentiated signal and generating a second peak signal; means for reducing the second peak signal to generate a second reduced peak signal; means for comparing the second reduced peak signal to the first peak signal to generate an output reset signal; and applying the output reset signal to the output means to reset the output signal.
Claim 9
Dependent Claim
44 words
A circuit for digitizing an analog electric signal according to claim 7, wherein the threshold circuit prevents the output means from responding to noise signals having amplitudes less than the second reduced signal, thereby preventing the output means from responding to signals between scans.
Claim 10
Dependent Claim
36 words
A circuit for digitizing an analog electric signal according to claim 5, wherein the first reduced peak signal is at least above a threshold level to prevent the output means from responding to low level noise.
Claim 11
Dependent Claim
19 words
A circuit for digitizing an analog electric signal according to claim 5, wherein the inverting means includes an amplifier.
Claim 12
Dependent Claim
42 words
A circuit for digitizing an analog electric signal according to claim 5, wherein the first peak detector includes a first amplifier circuit for detecting peaks of the inverted signal and a second amplifier circuit for detecting peaks of the first differentiated signal.
Claim 13
Dependent Claim
35 words
A circuit for digitizing an analog electric signal according to claim 5, wherein the means for reducing the first peak signal to the predetermined level includes a voltage divider coupled to the first peak detector.
Claim 14
Dependent Claim
19 words
A circuit for digitizing an analog electric signal according to claim 5, wherein the logic circuit includes a flip-flop.
Claim 15
Dependent Claim
25 words
A circuit for digitizing an analog electric signal according to claim 1, further comprising a threshold circuit for resetting the output means after each scanning.
Claim 16
Dependent Claim
32 words
A circuit for digitizing an analog electric signal according to claim 1, wherein the output means includes a flip-flop and a transistor coupled to the flip-flop for outputting the digital output signal.
Claim 17
Independent Claim
111 words
A method for digitizing an analog electric signal generated from a photoelectronic conversion of light reflected off from scanning indicia having spatially-separated, light-reflective portions, the method comprising the steps of: differentiating the analog electric signal to generate a first differentiated signal; receiving the first differentiated signal and generating a synchronizing signal corresponding to transitions in the spatially-separated, light-reflective portions of the indicia; generating a first digital signal having transitions corresponding to the transitions of the spatially-separated, light-reflective portions of the indicia; and receiving the synchronizing signal and the digital signal and producing a digital output signal having transitions corresponding to the transitions of the spatially-separated, light-reflective portions of the scanning indicia.
Claim 18
Independent Claim
111 words
A method for digitizing an analog electric signal generated from a photoelectronic conversion of light reflected off from scanning indicia having spatially-separated, light-reflective portions, the method comprising the steps of: differentiating the analog electric signal to generate a first differentiated signal; receiving the first differentiated signal and generating a synchronizing signal corresponding to transitions in the spatially-separated, light-reflective portions of the indicia; generating a first digital signal having transitions corresponding to the transitions of the spatially-separated, light-reflective portions of the indicia; and receiving the synchronizing signal and the digital signal and producing a digital output signal having transitions corresponding to the transitions of the spatially-separated, light-reflective portions of the scanning indicia.
Claim 19
Dependent Claim
68 words
A circuit for digitizing an analog electric signal according to claim 16, wherein the step of generating the synchronizing signal comprises steps of: shifting the first differentiated signal by a predetermined amount to generate a shifted signal; comparing the first differentiated signal and the shifted signal to generate a comparator output signal; and receiving the comparator output signal and generating the synchronizing signal from the indicia being scanned.
Claim 20
Dependent Claim
115 words
A circuit for digitizing an analog electric signal according to claim 16, wherein the step of generating the first digital signal comprises the steps of: inverting the first differentiated signal and generating an inverted signal; generating, in response to the inverted signal and the first differentiated signal, a first peak signal; reducing the first peak signal to a predetermined level to generate a first reduced peak signal; comparing the first reduced peak signal to the inverted signal and generating a second digital signal; comparing the first reduced peak signal to the first differentiated signal and generating a third digital signal; and producing, in response to the second and third digital signals, the first digital signal.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-07-24 | 1999-01-23 | 1999-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-07-24 | 2003-01-23 | 2003-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-07-24 | 2007-01-23 | 2007-07-25 | $7700.00 | Window Closed / Lapsed |