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US4748676A Expired / Lapsed US ⏱️ 0.0 years remaining

Pattern rotation angle detecting system

Assignee: Fuji Electric Co Ltd
•
Filing: 1987-05-14
•
Granted: 1988-05-31
•
Expires: 2007-05-14
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Abstract

Abstract A pattern rotation angle detecting system in which the angle of rotation of a pattern is detected according to the image data obtained by binary-coding and spatially-dividing the image signal of the pattern. The system comprises an extracting circuit for extracting the area and the moment of inertia of the image of the pattern directly from the binary-coded image data; a memory for storing the image data; and a processing circuit for obtaining the center of gravity of the image of the pattern using the area and the moment of inertia, circularly scanning the memory in such a manner that a circle is described having a center at the center of gravity, extracting arcuate segments, selecting as a reference arcuate segment one of the arcuate segments which satisfies predetermined conditions, mating a sample under detection with a standard sample using the properties of the reference arcuate segment and at least one arcuate segment from each side of the reference segments, and detecting the angle of rotation from the angle defined by the angle formed by a rotation angle reference point of the reference arcuate segment with respect to a predetermined reference line.

Inventors

  • 👤 Michiaki Miyagawa
  • 👤 Yutaka Ishizaka

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-23 16:55
CPC Classifications
G; G06; G06T; G06T7/00; G06T7/20; G06V; G06V10/00; G06V10/40; G06V10/42; G06V10/421

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 188 words
A system for detecting a rotational angle of a two-dimensional pattern converted into binary picture information, comprising: memory means for storing said picture information; extracting means for extracting an area and a moment of inertia of said objective pattern from said picture information; center of gravity detection means for determining a center of gravity of said objective pattern from said area and said moment of inertia of said objective pattern; circular scanning means for scanning said stored picture information to describe a circle having a predetermined radius and a center at said center of gravity; arcuate segment calculating means for calculating a plurality of arcuate segments from data produced by the circular scanning means, by using a reference arcuate segment having predetermined characteristics and by using at least one arcuate segment on each side of said reference arcuate segment, said plurality of arcuate segments being used to mate said pattern with a standard sample; and final calculation means for detecting said rotational angle, said angle defined by an angle formed by a rotation angle reference point of said reference arcuate segment with respect to a predetermined reference line.
Claim 2
Independent Claim 188 words
A system for detecting a rotational angle of a two-dimensional pattern converted into binary picture information, comprising: memory means for storing said picture information; extracting means for extracting an area and a moment of inertia of said objective pattern from said picture information; center of gravity detection means for determining a center of gravity of said objective pattern from said area and said moment of inertia of said objective pattern; circular scanning means for scanning said stored picture information to describe a circle having a predetermined radius and a center at said center of gravity; arcuate segment calculating means for calculating a plurality of arcuate segments from data produced by the circular scanning means, by using a reference arcuate segment having predetermined characteristics and by using at least one arcuate segment on each side of said reference arcuate segment, said plurality of arcuate segments being used to mate said pattern with a standard sample; and final calculation means for detecting said rotational angle, said angle defined by an angle formed by a rotation angle reference point of said reference arcuate segment with respect to a predetermined reference line.
Claim 3
Dependent Claim 31 words
The system of claim 1, wherein the predetermined characteristics of said reference arcuate segment are determined by using data relating to variation point coordinates, picture element logic levels, and subtending angles.
Claim 4
Dependent Claim 23 words
The system of claim 1, wherein said reference arcuate segment has a maximum value of a plurality of values of said subtending angles.
Claim 5
Dependent Claim 23 words
The system of claim 1, wherein said reference arcuate segment has a minimum value of a plurality of values of said subtending angles.
Claim 6
Dependent Claim 16 words
The system of claim 1, wherein said reference arcuate segment is determined using said standard sample.
Claim 7
Independent Claim 19 words
The system of claims 1, 2, 3, 4, or 5, wherein said rotation angle reference point can be preset.
Claim 8
Independent Claim 25 words
The system of claims 1, 2, 3, 4, or 5, wherein a plurality of coordinates obtained in said circular scanning are normalized for memory access.

References Cited (Backward Citations)

US4435837A Cited
US4499597A Cited
US4630225A Cited
US4680802A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1991-05-31 1991-11-30 1992-05-31 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1995-05-31 1995-11-30 1996-05-31 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1999-05-31 1999-11-30 2000-05-31 $7700.00 Window Closed / Lapsed

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