US4160237A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical reader for multiline image processing
Assignee: Unisys Corp
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Filing: 1978-02-02
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Granted: 1979-07-03
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Expires: 1998-02-02
Abstract
Abstract The polarization of a scanning laser beam is made to oscillate at a relatively high frequency between orthogonal polarization states while being raster scanned across a multiple line pattern at a lower rate. A birefringent element in the optical path causes the two polarization states cyclically to produce light spots of two different sizes at each illuminated point of the image. This difference in spot size produces an oscillating change in the scattered light power when the grey level illuminated by the smaller spot differs from the average grey level of the surrounding area. The polarity of the detected scattered light signal relative to the polarity of the voltage producing the oscillating polarization state is used to classify the surveyed points in the image into a pattern of binary coded numbers which are readily stored or otherwise processed for pattern recognition purposes.
Inventors
- 👤 Donald H. McMahon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:31
CPC Classifications
G; G06; G06V; G06V40/00; G06V40/10; G06V40/12; G06V40/13; G06V10/00; G06V10/10; G06V10/12
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
144 words
In optical pattern inspection apparatus: source means for generating a light beam, first signal generator means, modulator means responsive to said first signal generator means for cyclically shifting the polarization of said light beam between first and second polarization states, focusing means responsive to said first and second polarization states for cyclically forming, at least at one point on said pattern, successive first and second spots of light of respective first and second different diameters, light detector means for receiving light scattered by said pattern when illuminated by said first or second spots of light, phase detector means responsive to said light detector means and to said first signal generator means for providing a variable polarity output representative of the difference in light scattered by said pattern from said first and second spots of light, and utilization means for utilizing said variable polarity output.
Claim 2
Dependent Claim
144 words
In optical pattern inspection apparatus: source means for generating a light beam, first signal generator means, modulator means responsive to said first signal generator means for cyclically shifting the polarization of said light beam between first and second polarization states, focusing means responsive to said first and second polarization states for cyclically forming, at least at one point on said pattern, successive first and second spots of light of respective first and second different diameters, light detector means for receiving light scattered by said pattern when illuminated by said first or second spots of light, phase detector means responsive to said light detector means and to said first signal generator means for providing a variable polarity output representative of the difference in light scattered by said pattern from said first and second spots of light, and utilization means for utilizing said variable polarity output.
Claim 3
Dependent Claim
55 words
Apparatus as described in claim 1 wherein: said first spot of light is formed by light of a first polarization, said second spot of a light is formed by light of a second polarization orthogonal to said first polarization, and said second spot of light is larger in diameter than said first spot of light.
Claim 4
Dependent Claim
41 words
Apparatus as described in claim 2 for inspection of adjacent pattern lines having a side-by-side generally conformal relation wherein said first spot of light is selected to have a diameter approximately equal to the average width of said adjacent pattern lines.
Claim 5
Dependent Claim
32 words
Apparatus as described in claim 3 wherein said second spot of light has a diameter falling in the range from about twice to about thrice that of said first spot of light.
Claim 6
Dependent Claim
28 words
Apparatus as described in claim 1 wherein said utilization means comprises processor means for converting said variable polarity output into binary data representative thereof and for storing same.
Claim 7
Dependent Claim
15 words
Apparatus as described in claim 1 wherein said source means comprises a monochromatic light source.
Claim 8
Dependent Claim
17 words
Apparatus as described in claim 1 wherein said first and second polarization states comprise orthogonal polarization states.
Claim 9
Dependent Claim
14 words
Apparatus as described in claim 7 wherein said collimator means comprises first lens means.
Claim 10
Dependent Claim
19 words
Apparatus as described in claim 8 wherein said first lens means is formed of a birefringent optically transparent material.
Claim 11
Dependent Claim
33 words
Apparatus as described in claim 9 wherein at least second lens means is interposed between said pattern and said light detector means for directing light scattered by said pattern into said light detector.
Claim 12
Dependent Claim
45 words
Apparatus as described in claim 1 further including means for cyclically scanning said light beam in regular sequence over said pattern whereby successive corresponding points on said pattern are successively illuminated by said first and second spots of light of respective first and second diameters.
Claim 13
Dependent Claim
51 words
Apparatus as described in claim 11 wherein said means for cyclically scanning comprises: second signal generator means, deflector means responsive to said second signal generator means for cyclically deflecting said light beam along a first direction, and motor means for moving said pattern in second direction normal to said first direction.
Claim 14
Dependent Claim
25 words
Apparatus as described in claim 12 wherein said second signal generator means includes: oscillator means, and sweep wave generator means responsive to said oscillator means.
Claim 15
Dependent Claim
33 words
Apparatus as described in claim 12 wherein said first signal generator means is characterized by generating an output wave of substantially higher frequency than the output wave of said second signal generator means.
Claim 16
Dependent Claim
28 words
Apparatus as described in claim 12 wherein said utilization means comprises processor means for converting said variable polarity output into binary data representative thereof and for storing same.
Claim 17
Dependent Claim
102 words
Apparatus as described in claim 15 wherein said processor means includes: trigger circuit means responsive to the output of said phase detector means, shift register means, master clock means, first counter means for counting a predetermined number of cycles of the output of said second signal generator means for generating scan end pulse, bistable circuit means having a set terminal responsive to said scan end means, second counter means responsive to said bistable circuit means and to said master clock means, and shift register means responsive to said second counter means, to said trigger circuit means, and to said bistable circuit means.
Claim 18
Dependent Claim
18 words
Apparatus as described in claim 16 further including manual means for initiating operation of said first counter means.
Claim 19
Dependent Claim
41 words
Apparatus as described in claim 17 further including: latch means, storage means, and third counter means responsive to said scan end pulse for generating enabling signals for transfer of said binary data from said shift register means into said latch means.
Claim 20
Dependent Claim
23 words
Apparatus as described in claim 18 further including fourth counter means responsive to said third counter means for resetting said bistable circuit means.
Claim 21
Dependent Claim
29 words
Apparatus as described in claim 19 wherein said third counter means is further adapted to enable transfer of said binary data from said latch means into said storage means.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-07-02 | 1983-01-01 | 1983-07-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-07-02 | 1987-01-01 | 1987-07-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-07-02 | 1991-01-01 | 1991-07-03 | $7700.00 | Window Closed / Lapsed |