EP0315939A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Color signature sensor
Assignee: Honeywell Inc
•
Filing: 1988-11-08
•
Granted: —
•
Expires: 2008-11-08
Abstract
Abstract A color signature sensor for color recognition or discrimination utilizes a spectral analysis system and may be used in process control or on-line quality assurance. An object (11) to be observed is illuminated by a suitable light source (10), light collected from the object under examination is routed into a monochrometer (16). The output of the monochrometer is fed to an analog-to-digital converter (19) and analyzed by a microprocessor (18).
Inventors
- 👤 Charles T. Sullivan
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 10:07
CPC Classifications
G; G01; G01J; G01J3/00; G01J3/02; G01J3/0205; G01J3/0218; G01J3/46; G01J3/50; G01J3/502; G01J2003/466; G01J3/28; G01J3/2803
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
210 words
A color signature sensor for recognizing or measuring color of an object characterized by a) said sensor having a diffraction grating (13) for spectrally dispersing light received from an object being observed onto a detector array (16); b) the detector array having a plurality of photodetectors each photodetector providing an output signal according to the spectrally dispersed light from said object; c) an analog-to-digital converter (19) to digitize the signals from the detector array to form a digitized set of signals for evaluation in a microprocessor (18); d) said microprocessor including means for receiving and storing the sample and digitized sets of signals from a reference object A and from an object B being observed, described collectively as an ordered sequence of weighted numbers representing the spectral constitution of the colored object A and of the colored object B; e) means for determining the mean-values of said digitized sets of signals; f) means for determining the cross-correlation between said sets of signals; g) means for determining the mean-value difference between the set of signals from reference object A and the set of signals from reference object B; and, h) means for providing a discrimination threshold and providing a mean-value difference discrimination threshold whereby two colors can be discriminated or matched.
Claim 2
Dependent Claim
210 words
A color signature sensor for recognizing or measuring color of an object characterized by a) said sensor having a diffraction grating (13) for spectrally dispersing light received from an object being observed onto a detector array (16); b) the detector array having a plurality of photodetectors each photodetector providing an output signal according to the spectrally dispersed light from said object; c) an analog-to-digital converter (19) to digitize the signals from the detector array to form a digitized set of signals for evaluation in a microprocessor (18); d) said microprocessor including means for receiving and storing the sample and digitized sets of signals from a reference object A and from an object B being observed, described collectively as an ordered sequence of weighted numbers representing the spectral constitution of the colored object A and of the colored object B; e) means for determining the mean-values of said digitized sets of signals; f) means for determining the cross-correlation between said sets of signals; g) means for determining the mean-value difference between the set of signals from reference object A and the set of signals from reference object B; and, h) means for providing a discrimination threshold and providing a mean-value difference discrimination threshold whereby two colors can be discriminated or matched.
Claim 3
Dependent Claim
251 words
A color signature sensor according to claim 1, characterized in that a) the digitized sets of signals from a reference object A and from an object B being observed are described collectively as where m is the number of photodetectors, n is the bit precision of the digitization process, is an ordered sequence of weighted numbers (a₀, a₁, a₂...a m-1 ) representing the spectral constitution of the colored object A, is an ordered sequence of weighted numbers (b₀, b₁, b₂...b m-1 ) representing the spectral constitution of the colored object B; b) the means for determining the mean-values η a and η b operate according to the relations where Σ is the summation of the m weighted values; c) means for determining the cross-correlation Ψ between I mn (A) and I mn (B) operate according to the relation d) the means for determining the mean-value difference φ between I mn (A) and I mn (B) operate according to the relation φ(A,B) = η a - η b ; and e) means providing a discrimination threshold for cross-correlation σ cc and providing a discrimination threshold for mean-value difference σ mvd , operate according to the provisions | Ψ (A,A′) - Ψ (A,B)| > σ cc > 0 or | Φ (A,A′) - Φ (A,B)| > σ mvd > 0 while if | Ψ (A,A′) - Ψ (A,B)| ≦ σ cc and | Φ (A,A′) - Φ (A,B)| ≦ σ mvd , the sample colors of A and B are said to match.
Claim 4
Independent Claim
221 words
A method for comparing the color of an object B with the color of a reference A characterized by the steps of: a) illuminating the object (11) and directing light therefrom to a spectral dispersive element (13) for spectrally dispersing the light received from the object; b) providing a detector array (16) for receiving the spectrally dispersed light and converting it to a set of analog electrical signals; c) receiving and converting (19) a set of analog signals representative of the color of the reference A to a set of digital signals; d) storing the digital signals (18, 21), representative of the reference color A, described collectively as an ordered sequence of weighted numbers representing the spectral constitution of the colored object A; e) receiving and converting similarly a set of signals representative of object color B, described collectively as an ordered sequence of weighted numbers representing the spectral constitution of the colored object B; f) determining the mean-values of said digital sets of signals; g) determining the cross-correlation between said sets of signals; h) determining the mean-value difference between the first and second set of signals; i) providing a discrimination threshold for cross-correlation and providing a discrimination threshold for mean-value difference; and, j) comparing object A and object B correlations and mean-value difference values whereby two colors can be discriminated.
Claim 5
Independent Claim
221 words
A method for comparing the color of an object B with the color of a reference A characterized by the steps of: a) illuminating the object (11) and directing light therefrom to a spectral dispersive element (13) for spectrally dispersing the light received from the object; b) providing a detector array (16) for receiving the spectrally dispersed light and converting it to a set of analog electrical signals; c) receiving and converting (19) a set of analog signals representative of the color of the reference A to a set of digital signals; d) storing the digital signals (18, 21), representative of the reference color A, described collectively as an ordered sequence of weighted numbers representing the spectral constitution of the colored object A; e) receiving and converting similarly a set of signals representative of object color B, described collectively as an ordered sequence of weighted numbers representing the spectral constitution of the colored object B; f) determining the mean-values of said digital sets of signals; g) determining the cross-correlation between said sets of signals; h) determining the mean-value difference between the first and second set of signals; i) providing a discrimination threshold for cross-correlation and providing a discrimination threshold for mean-value difference; and, j) comparing object A and object B correlations and mean-value difference values whereby two colors can be discriminated.
Claim 6
Dependent Claim
262 words
The method according to claim 3, characterized in that : a) the stored digital signals (20, 22, 21), representative of the reference color A, are described collectively as where m is the number of photodetectors, n is the bit precision of the digitization process, is an ordered sequence of weighted numbers (a₀, a₁, a₂...a m-1 ) representing the spectral constitution of the colored object A; b) the converted set of digital signals representative of object color B are described collectively as where is an ordered sequence of weighted numbers (b₀, b₁, b₂...b m-1 ) representing the spectral constitution of the colored object B; c) the mean-values η a and η b are determined according to the relations Σ is the summation of the m weighted values; d) the cross-correlation Ψ between I mn (A) and I mn (B) is determined according to the relation e) the mean-value difference φ between I mn (A) and I mn (B) is determined according to the relation φ(A,B) = η a - η b ; f) the reference A and object B values of the discrimination threshold for cross-correlation σ cc and for the mean-value difference σ mvd are compared, whereby two colors can be discriminated provided |Ψ (A,A′) - Ψ (A,B) | > σ cc > 0 or | Φ (A,A′) - Φ (A,B) | > σ mvd > 0 while if | Ψ (A,A′) - Ψ (A,B) | ≦ σ cc and | Φ (A,A′) - Φ (A,B) | ≦ σ mvd , the sample colors of A and B are said to match.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.