US3768913A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for evaluation of the intensity of spots
Assignee: Individual
•
Filing: 1971-10-27
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Granted: 1973-10-30
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Expires: 1991-10-27
Abstract
Abstract A method and apparatus to measure the integrated density of spots on photographic films is disclosed. The coordinates of spots of normal density are measured and stored in analog form in an analog memory. Evaluation of the integrated density of weak spots is achieved by borrowing from the memory the coordinates of a previous spot of normal density and using said coordinates as the contour of the weak spot. Existence conditions are given for a spot of normal density.
Inventors
- 👤 V Klimecki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 05:05
CPC Classifications
G; G03; G03B; G03B42/00; G03B42/02; G01; G01J; G01J1/00; G01J1/42; G01N; G01N21/00; G01N21/17; G01N21/25; G01N21/27; G01N21/59; G01N21/5907
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
181 words
A method of calculating the blackening of spots, particularly weakly blackened spots, exposed on photographic film, said method comprising the steps of i. line-wise scanning a well defined area of the film with a light beam ii. detecting the light transmitted through the film and iii. converting the detected light into an electric signal the magnitude of which then corresponds to the absolute optical density of the area being illuminated by the beam, characterized by the following steps a. measuring the relative optical density along each scanned line simultaneously with b. deriving the coordinates of the coutour of the spot being measured, said coordinates being related to the relative optical density of the spot being measured, c. storing in a memory the absolute optical density values measured during each scanned line or only said coordinates, d. classifying the spot with regard to its relative optical density and the extension of its contour in order to eliminate any further calculations on non-relevant exposed spots, ''''fuzz'''' and the like, and e. integrating the relative optical density of the spot only within its contour.
Claim 2
Independent Claim
181 words
A method of calculating the blackening of spots, particularly weakly blackened spots, exposed on photographic film, said method comprising the steps of i. line-wise scanning a well defined area of the film with a light beam ii. detecting the light transmitted through the film and iii. converting the detected light into an electric signal the magnitude of which then corresponds to the absolute optical density of the area being illuminated by the beam, characterized by the following steps a. measuring the relative optical density along each scanned line simultaneously with b. deriving the coordinates of the coutour of the spot being measured, said coordinates being related to the relative optical density of the spot being measured, c. storing in a memory the absolute optical density values measured during each scanned line or only said coordinates, d. classifying the spot with regard to its relative optical density and the extension of its contour in order to eliminate any further calculations on non-relevant exposed spots, ''''fuzz'''' and the like, and e. integrating the relative optical density of the spot only within its contour.
Claim 3
Dependent Claim
56 words
The method as claimed in claim 1, characterized by moving the light beam with constant speed over the film surface while the film is at rest and moving the film in a direction perpendicular to the line a distance corresponding to the extension of the light beam in said perpendicular direction during two successively scanned lines.
Claim 4
Dependent Claim
30 words
The method as clained in claim 2, characterized in that the illuminated area of the film is generally rectangular and has an area of which is maintained constant during scanning.
Claim 5
Dependent Claim
99 words
The method as claimed in claim 1, characterized in that the relative optical density is measured by the following steps i. detecting the mean value of the absolute optical density during a short period (t1-t2) at the beginning and during a short period (t5-t6) at the end of each scanned line ii. linearly extrapolating between said two mean values in order to derive values representing the absolute optical density at the background of the spot for each scanned line iii. substracting the absolute optical density of the extrapolated background from the absolute optical density values of the scanned line.
Claim 6
Dependent Claim
56 words
The method as claimed in claim 4, further characterized by the addition of a constant ( Delta D) the magnitude of which generally corresponds to the variation of the absolute optical density of the background of the spot to the extrapolated background before subtraction of this from the absolute optical density values of the scanned line.
Claim 7
Dependent Claim
53 words
The method as claimed in claim 5, characterized by deriving said coordinates by sensing the times at which the relative optical density for each scanned line crosses zero and remains positive for a predetermined time (ts) therebetween, said times representing the coordinates of the contour of the part of the spot being scanned.
Claim 8
Dependent Claim
67 words
The method as clained in claim 6, characterized in that the density values stored in the memory are first classified to find out to which of the following classes the spot belongs: A. absolute oPtical density exceeding a first predetermined value, B. relative optical density smaller than a predetermined second value C. relative optical density exceeding the second predetermined value but smaller than the first predetermined value.
Claim 9
Dependent Claim
82 words
The method as claimed in claim 5, characterized by the following steps i. stopping the further scanning and calculation of this spot if the spot belongs to class A and going to a new well defined area to be investigated ii. integrating the relative optical density of the spot within the contour of the next preceding spot classified as belonging to class C if the spot belongs to class B and iii. further analyzing the spot if it belongs to class C.
Claim 10
Dependent Claim
127 words
The method as claimed in claim 8, characterized in that said further analysis comprises the steps of i. ascertaining whether the extension of the spot in the direction of a line exceeds a third predetermined value (ts) ii. ascertaining whether the extension of the spot in a direction prependicular to a line exceeds a fourth predetermined value (b-c) iii. ascertaining whether the relative optical density of the spot exceeds a fifth predetermined value (Dix), and if any of these conditions are not fulfilled, iiii. stopping the further scanning and calculation of the spot and going to a new well defined area to be investigated and if all of the conditions are fulfilled iiiii. integrating the relative optical density of the spot within the contour of the spot.
Claim 11
Independent Claim
163 words
An apparatus for the evaluation of the blackening of spots, particularly weakly blackened spots exposed on photographic film, said apparatus comprising a scanning system including a light beam (9) line-wise scanning a well defined area of a photographic film (7) having said spots exposed thereon an electrical arrangement for converting the transmitted light into an electrical voltage (D) representing the optical density values of the scanned lines, an integrating circuit for integrating the optical density values and memory means characterized by first circuit means for deriving the relative optical density of a spot, second circuit means for deriving the boundary points of the contour of a spot, program control means responsive to the absolute as well as relative optical values in order to call in different programs each one controlling the integration of the relative optical density values of a spot in dependence on the boundary points stored in the memory, and integrating means for integrating the relative optical density of said spot.
Claim 12
Independent Claim
163 words
An apparatus for the evaluation of the blackening of spots, particularly weakly blackened spots exposed on photographic film, said apparatus comprising a scanning system including a light beam (9) line-wise scanning a well defined area of a photographic film (7) having said spots exposed thereon an electrical arrangement for converting the transmitted light into an electrical voltage (D) representing the optical density values of the scanned lines, an integrating circuit for integrating the optical density values and memory means characterized by first circuit means for deriving the relative optical density of a spot, second circuit means for deriving the boundary points of the contour of a spot, program control means responsive to the absolute as well as relative optical values in order to call in different programs each one controlling the integration of the relative optical density values of a spot in dependence on the boundary points stored in the memory, and integrating means for integrating the relative optical density of said spot.
Claim 13
Dependent Claim
106 words
The apparatus as claimed in claim 10, characterized in that said scanning system comprises a light source, a plate illuminated by said light source, an aperture in said plate, a disc rotatably mounted behind said plate and being provided along its periphery with a number of equally spaced, radially extending slots, said slots during rotation of said disc in cooperation with said aperture defining a generally rectangular light beam having a constant cross sectional area, a lens and mirror arrangement directing said light beam onto a surface to be scanned by the light beam, and a photomultiplier picking up the radiation transmitted through said illuminated surface.
Claim 14
Dependent Claim
44 words
The apparatus as claimed in claim 11, characterized by a non-linear circuit modifying said photomultiplier signal for compensating any variations in the sensitivity of the scanning system in any desired number of points along the path travelled by the light beam during a sweep.
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) | 1976-10-29 | 1977-04-30 | 1977-10-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-29 | 1981-04-30 | 1981-10-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-29 | 1985-04-30 | 1985-10-30 | $7700.00 | Window Closed / Lapsed |