US3804531A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Color analyzer
Assignee: Individual
•
Filing: 1972-03-01
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Granted: 1974-04-16
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Expires: 1992-03-01
Abstract
Abstract A color analyzer for measuring a color synthesized by the additive mixture of primary colors, each having an arbitrary but constant relative spectral energy distribution. The color analyzer has a light receiving portion consisting of three or more photoelectric transducer elements equal in number to said primary colors and having independent spectral sensitivities, so as to generate electric quantities representing the received optical energy levels, and an electric calculating circuit for generating electric outputs representing the energy levels of said primary colors individually, independently and simultaneously. The color analyzer can also measure the luminance of the light source, and display CIE chromaticity.
Inventors
- 👤 T Kosaka
- 👤 S Murakami
- 👤 M Naya
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 01:43
CPC Classifications
G; G06; G06G; G06G7/00; G06G7/48; G06G7/75; G01; G01J; G01J3/00; G01J3/46; G01J3/462; G01J3/465; G01J3/52; G01J3/524; G01J3/50; G01J3/51; G01J3/513
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
267 words
A color analyzer for determining individual primary color output levels of any light source constituted by the additive color mixture of primary color stimuli having an arbitrary but fixed spectral distribution comprising: at least three photodetector means responsive to different spectraL portions of the light emitted by said source and for providing electric signals proportional to the light incident thereon, the spectral sensitivity of each photodetector means corresponding with the spectral distribution of a given additive primary color; an electric matrix circuit means responsive to the signals generated by the photodetector means for analyzing the information in said signals by solving the following equation: xB A11 A12 A13 CB xG A21 A22 A23 CG xR A31 A32 A33 CR wherein xb, xG and xR are the coefficients of the energy levels of the blue, green and red additive primary color stimuli respectively of the color to be measured, CB, CG and CR are integral terms representing the color emitted by each additive primary color stimulus at a predetermined energy level represented by the aforementioned coefficients and as detected by each of said photodetector means with the aforementioned spectral sensitivities; and Aij (i 1-3, j 1-3) are the integral terms corresponding to the color emitted by each additive primary color stimulus regardless of the energy level but due to its fixed energy level distribution which is independent of energy level, and as detected by each of said photodetector means with the aforementioned spectral sensitivities; and indicator means connected to said matrix circuit means to indicate the energy level of a respective one of the additive primary color stimuli.
Claim 2
Dependent Claim
267 words
A color analyzer for determining individual primary color output levels of any light source constituted by the additive color mixture of primary color stimuli having an arbitrary but fixed spectral distribution comprising: at least three photodetector means responsive to different spectraL portions of the light emitted by said source and for providing electric signals proportional to the light incident thereon, the spectral sensitivity of each photodetector means corresponding with the spectral distribution of a given additive primary color; an electric matrix circuit means responsive to the signals generated by the photodetector means for analyzing the information in said signals by solving the following equation: xB A11 A12 A13 CB xG A21 A22 A23 CG xR A31 A32 A33 CR wherein xb, xG and xR are the coefficients of the energy levels of the blue, green and red additive primary color stimuli respectively of the color to be measured, CB, CG and CR are integral terms representing the color emitted by each additive primary color stimulus at a predetermined energy level represented by the aforementioned coefficients and as detected by each of said photodetector means with the aforementioned spectral sensitivities; and Aij (i 1-3, j 1-3) are the integral terms corresponding to the color emitted by each additive primary color stimulus regardless of the energy level but due to its fixed energy level distribution which is independent of energy level, and as detected by each of said photodetector means with the aforementioned spectral sensitivities; and indicator means connected to said matrix circuit means to indicate the energy level of a respective one of the additive primary color stimuli.
Claim 3
Dependent Claim
106 words
A color analyzer as claimed in claim 1 wherein: X E11 E12 E13 CB Y E21 E22 E23 CG Z E31 E32 E33 CR wherein X, Y and Z are outputs of the matrix circuit means which correspond to C.I.E. tristimulus values of the color to be measured and Eij (i 1-3, j 1-3) where Cij.Dij (i 1-3, j 1-3) where Cij are integral terms representing the color emitted by each additive primary color stimulus as detected by each detector means with a fixed C.I.E. tristumulus spectral distribution sensitivity, and where Dij represent individual terms of the inverse matrix of the aforesaid matrix having coefficients Aij.
Claim 4
Dependent Claim
34 words
A color analyzer as claimed in claim 1 wherein each photodetector means includes a photoelectric cell and a color filter for transmitting only light energy of a selected spectral band to the respective cell.
Claim 5
Dependent Claim
25 words
A color analyzer as claimed in claim 1 wherein said indicating means includes three indicators connected respectively with the outputs of the matrix circuit means.
Claim 6
Dependent Claim
32 words
A color analyzer as claimed in claim 1 comprising a servo-system and wherein the matrix circuit means includes outputs connected with said servo-system which adjusts automatically the quantity of each primary color.
Claim 7
Dependent Claim
42 words
A color analyzer as claimed in claim 1 wherein each photodetector means has a spectral sensitivity corresponding respectively to each of the spectral energy distributions of the primary colors and the adjacent characteristic curves of the spectral sensitivities slightly overlap each other.
Claim 8
Dependent Claim
25 words
A color analyzer as claimed in claim 1 wherein the matrix circuit means includes exchangeable circuits independent of one another and having different circuit constants.
Claim 9
Dependent Claim
27 words
A color analyzer as claimed in claim 7 wherein more than two matrix circuits are provided selectably corresponding to the characteristics of an object to be measured.
Claim 10
Dependent Claim
40 words
A color analyzer as claimed in claim 1 including memory members and wherein the photodetector means are exchangeable with the memory members to obtain electric signals corresponding to outputs of the photodetector means which receive a light of standard color.
Claim 11
Dependent Claim
24 words
A color analyzer as clAimed in claim 9 further comprising more than one group of memory members which are exchangeable for the photodetector means.
Claim 12
Dependent Claim
39 words
A color analyzer as claimed in claim 1 wherein each photodetector means comprises a photoconductive cell, load resistances, and a transistor including an emitter connected with the photoconductive cell and a collector connected with the load resistances in series.
Claim 13
Dependent Claim
25 words
A color analyzer as claimed in claim 11 wherein each photodetector means includes two condensers connected respectively in parallel with one of the load resistances.
Claim 14
Dependent Claim
22 words
A color analyzer as claimed in claim 12 further comprising a plurality of condensers connected respectively in parallel with each load resistance.
Claim 15
Dependent Claim
58 words
A color analyzer as claimed in claim 1 wherein each photodetector means comprises a photovoltaic cell, a differential amplifier circuit, one terminal of the cell being connected with one input terminal of the amplifier circuit, and a feed-back resistance, the output terminal of the amplifier circuit being connected with said terminal fo the cell through the feedback resistance.
Claim 16
Dependent Claim
21 words
A color analyzer as claimed in claim 14 wherein the electric matrix circuit includes said feedback resistances and six further resistances.
Claim 17
Dependent Claim
17 words
A color analyzer as claimed in claim 15 wherein each amplifier circuit includes two field effect transistors.
Claim 18
Dependent Claim
20 words
A color analyzer as claimed in claim 16 further comprising three condensers connected respectively in parallel with said feedback resistance.
References Cited (Backward Citations)
US2716717A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-04-15 | 1977-10-15 | 1978-04-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-15 | 1981-10-15 | 1982-04-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-15 | 1985-10-15 | 1986-04-16 | $7700.00 | Window Closed / Lapsed |