US3631234A - Electrical apparatus for obtaining filter pack density values - Google Patents
Electrical apparatus for obtaining filter pack density values Download PDFInfo
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- US3631234A US3631234A US801350A US3631234DA US3631234A US 3631234 A US3631234 A US 3631234A US 801350 A US801350 A US 801350A US 3631234D A US3631234D A US 3631234DA US 3631234 A US3631234 A US 3631234A
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- color film
- circuit
- potentiometers
- density values
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- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
- G03B27/00—Photographic printing apparatus
- G03B27/72—Controlling or varying light intensity, spectral composition, or exposure time in photographic printing apparatus
- G03B27/73—Controlling exposure by variation of spectral composition, e.g. multicolor printers
- G03B27/735—Controlling exposure by variation of spectral composition, e.g. multicolor printers in dependence upon automatic analysis of the original
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06G—ANALOGUE COMPUTERS
- G06G7/00—Devices in which the computing operation is performed by varying electric or magnetic quantities
- G06G7/48—Analogue computers for specific processes, systems or devices, e.g. simulators
- G06G7/75—Analogue computers for specific processes, systems or devices, e.g. simulators for component analysis, e.g. of mixtures, of colours
Definitions
- a computation circuit is electrically connected to the visual indicators and to a standard color film circuit and to a pack control circuit and to a production color film circuit for electrically processing signals from a plurality of potentiometers in the respective circuits.
- the signals correspond to density values associated with the respective item recorded therein whereby when the computation circuit is activated, numerical density values for the filter pack for the production color film are displayed by the visual indicators.
- the present invention relates to photographic apparatus and more particularly to electrical apparatus for comparing density values of a standard color film and its filter pack with density values of a production color film to obtain density values for a filter pack for use with the production color film.
- F IG. 1 is a perspective view of a cabinet containing an electrical apparatus for obtaining density values for a production filter pack embodying features of the present invention.
- F IG. 2 is a wiring diagram of the electrical apparatus for obtaining the filter pack density values with the essential operating parts diagrammatically shown.
- FIG. 3 is a detailed wiring diagram of a computation circuit for the electrical apparatus.
- the reference numeral 1 generally designates a cabinet for containing electrical apparatus 2 for obtaining density values for a filter pack (not shown) for use with a production color film (not shown).
- the electrical apparatus 2 has a plurality of adjustable potentiometers, each adapted to produce a signal having a coded value responsive to adjustment thereof and a computation circuit 3 electrically connected to the potentiometers for processing the signals therefrom.
- the electrical apparatus 2 has visual indicators 4 and 5 electrically connected to the computation circuit 3 for displaying numerical values corresponding to results of processing the potentiometer signals with the numerical values displayed corresponding to density values of the filter pack for the production color film.
- a computation reference source 6 is electrically connected to the potentiometers and is adapted to produce a reference signal of substantially constant intensity for generating precise potentiometer signals.
- Potentiometers 7, 8 and 9 are arranged in a standard color film circuit 10.
- the potentiometers 7, 8 and 9 are adjusted by knobs ll, 12 and 13 respectively, each of which has dials 14 for visually displaying numerical values corresponding to the adjustment of the respective potentiometers.
- the dials 14 on the knobs ll, 12 and 13 display numerical values representing red, green and blue density values respectively of a standard color film or control film (not shown).
- the potentiometers 7, 8 and 9 are mounted in series between conductors l5 and 16 which are electrically connected to the computation reference source 6 whereby, when the electrical apparatus 2 is activated by a pushbutton 17, the potentiometers 7, 8 and 9 will produce signals which correspond to the density values of red, green and blue respectively.
- Potentiometers l8 and 19 are arranged in a pack control circuit 20 with the potentiometers l8 and 19 being adjusted by knobs 21 and 22, each of which have dials 23 for visually displaying green and blue net density values ofa filter pack (not shown) for the standard color film or control film.
- the potentiometers l8 and 19 are connected in series between conductors 24 and 25 which are also connected to the computation reference source 6 for producing signals representing the green and blue net density values respectively of the filter pack for use with the standard control film.
- Potentiometers 26, 27 and 28 are arranged in a production color film vcircuit 29 and are adjusted by knobs 30, 31 and 32 respectively, each of which have dials 33 to visually display numerical values representing the adjustment of the respective potentiometers.
- the potentiometers 26, 27 and 28 are electrically connected in series between conductors 34 and 35 which are electrically connected to the computation reference source 6.
- the computation circuit 3 is adapted to electrically sum positive and negative signals from the red potentiometers 7 and 26 and from the green potentiometers 8, l8 and 27 and from the blue potentiometers 9, l9 and 28 to produce net signals for processing in the computation circuit 3.
- the computation circuit 3 includes a portion to receive the net signal associated with the respective primary colors and has a red channel, green channel and blue channel respectively with a power source 36 electrically connected to operational amplifiers 37, 38 and 39 in the red, green and blue channels respectively.
- a conductor 40 extends between a neutral conductor 41 of the power source 36 and the operational amplifiers 37, 38 and 39 with resistors 42, 43 and 44 being electrically connected between conductor 40 and noninverting inputs of the operational amplifiers 37, 38 and 39 respectively.
- the resistors 42, 43 and 44 are each in the nature of 30 K0, Aw, or) 5 percent resistors.
- Offset balancing potentiometers 45, 46 and 47 are associated with the operational amplifiers 37, 38 and 39 respectively with the potentiometers 45, 46 and 47 each being in the nature of 2.5 K!) ohm potentiometers and being connected to the power source 36 by conductors 48 and 49.
- Amplification completion loops 50, 51 and 52 are associated with the red, green and blue channel operational amplifiers 37 38 and 39 respectively with capacitors 53, 54 and 55 being positioned in the amplification completion loops 50, 51 and 52 respectively to average the input to substantially reduce noise in the computation circuit 3.
- Resistors 56, 57 and 58 are connected across the amplification completion loops 50, 51 and 52 respectively with each of the resistors 56, 57 and 58 being in the nature of 200 KO, or 0.02 percent resistors.
- a plurality of resistors 59 are connected to each of the respective operational amplification completion loops 50, 51 and 52 and are also in the nature of 200 K0, or 0.02 percent resistors.
- the amplification completion loops 50, 5] and 52 are connected to output conductors 60, 61 and 62 respectively whereby voltage in the output conductor 60 corresponds to the integral red density (neutral density) of the filter pack for the production color film and the voltage in the output condoctors 61 and 62 corresponds to the integral net densities for the green and blue channels respectively.
- the red or neutral density is cancelled by the computation circuit 3 by electrically adding to the green and blue signals an electrical signal equivalent to but of opposite sign to the red or neutral density thereby eliminating red or neutral density.
- a switch 63 is positioned on a cabinet front panel 64 and is movable between an on" and an off" position to supply electrical power to the computation reference source 6 and the power source 36.
- the computation reference source 6 is adapted to produce a substantially constant output reference signal, such as in the nature of l0.00 volts.
- Manipulation or adjustment of the various knobs varies respective resistances in the respective potentiometers whereby, when the reference signal passes through the respective potentiometers, a signal is produced having a value responsive to adjustment thereof with the potentiometer signals corresponding to respective density values.
- the potentiometer signals are electrically summed for each of the red, green and blue channels in computation circuit 3.
- a calibration circuit 65 is electrically connected to the computation circuit 3 and to the visual indicators 4 and 5.
- P is the green and blue density values of a filter pack for use with the control film and ND. is neutral density and it is preferably the lesser density value of the red, green and blue density values and in the illustrated electrical apparatus, red has been selected as the neutral density to accommodate other printing operations.
- P is the desired density values for a filter pack for use with the production color film and P, is the density values displayed on the visual indicators 4 and 5 respectively.
- a color print is made from the standard color film or the control film and the density values of the standard color film and the filter pack used therewith for making the color print are obtained by using a densitometer.
- the density values for the standard color film and its filter pack are placed in the electrical apparatus 2 by adjusting the potentiometers 7, 8 and 9 and the potentiometers l8 and 19 whereby the dials l4 display values corresponding to the red, green and blue density values of the standard color film on the knobs l1, l2 and 13 respectively and the dials 23 display the density values of the filter pack on the knobs 21 and 22 respectively.
- a production color film from which it is desired to make a color print having color characteristics corresponding to the color print made from the standard color film and its filter pack is placed in a densitometer to obtain the red, green and blue density values thereof which are then placed in the electrical apparatus 2 by adjustment of the potentiometers 26, 27 and 28 respectively.
- the pushbutton 17 is depressed to activate the computation circuit 3 which processes the signals from the respective potentiometers in the circuits 10, 20 and 29 to visually display numerical values on the visual indicators 4 and 5 corresponding to density values for a filter pack for use with the production color film having the density values corresponding to the signals produced by the potentiometers 26, 27 and 28.
- Electrical apparatus for obtaining density values for a production filter pack for use in making a print from a production color film, the electrical apparatus comprising:
- a plurality of circuits each having a plurality of said potentiometers therein arranged in a plurality of channels; said potentiometers being arranged in a color film density circuit and a pack control circuit and a production color film density circuit, said potentiometers in said color film density circuit being operative to produce signals representing selected density values of a control color film, said potentiometers in said pack control circuit being operative to produce signals representing selected density values of a filter pack for use with the control color film in making a print therefrom, said selected densit values of a production color film, said density values emg for the primary colors of red and green and blue for said color film density circuit and said production color film density circuit, said density values being for the primary colors of green and blue for said pack control circuit and for the filter pack for the production color film;
- a computation circuit electrically connected to said potentiometers in said channels of said circuits for processing said signals therefrom, said computation circuit being operative to electrically sum said potentiometer signals for each of the respective colors and electrically cancel one of the respective colors from said electrical summation, said computation circuit including an operational amplifier for the channel for each of said primary colors and balancing means electrically connected to each of said operational amplifiers for balancing current therethrough and circuit noise reduction means electrically connected to each of said operational amplifiers and a plurality of resistors electrically connected to each of said operational amplifiers;
- a computation reference source operative to produce a reference signal of substantially constant intensity for comparing each potentiometer signal therewith.
- said potentiometers are each digitally coded switches to correspond to said respective density values
- said computation circuit processes said digitally coded signals in a digital manner.
- An electrical apparatus as set forth in claim 2 including display means operatively connected to each of said digitally coded switches for displaying numerical values representing adjustment of said respective digitally coded switches, said numerical values representing respective density values of the standard color film and the filter pack therefor and the production color film.
- An electrical apparatus for obtaining numerical density values for a production filter pack for use in making a print from a production color film comprising:
- a plurality of visual indicators electrically connected to said computation circuit for displaying numerical values representing results of processing the potentiometer signals, said numerical values representing density values for a filter pack for use in making a print from a production color film;
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- Engineering & Computer Science (AREA)
- Computer Hardware Design (AREA)
- General Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Mathematical Physics (AREA)
- Spectrometry And Color Measurement (AREA)
Abstract
Electrical apparatus for obtaining density values for a filter pack for use with a production color film by comparing density values of a standard color film and its filter pack with the production color film, said apparatus having visual indicators for displaying the obtained net density values for the filter pack for the production color film. A computation circuit is electrically connected to the visual indicators and to a standard color film circuit and to a pack control circuit and to a production color film circuit for electrically processing signals from a plurality of potentiometers in the respective circuits. The signals correspond to density values associated with the respective item recorded therein whereby when the computation circuit is activated, numerical density values for the filter pack for the production color film are displayed by the visual indicators.
Description
United States Patent [72] Inventors John V. Hanline Kansas City, Mo.; Daniel M. Chopin, Shawnee Mission, Thus. [21] Appl. No. 801,350 [22] Filed Feb. 24, 1969 [45] Patented Dec. 28, 1971 [73] Assignee Film Equipment Manufacturing Co. Kansas City, Mo.
[54] ELECTRICAL APPARATUS FOR OBTAINING FILTER PACK DENSITY VALUES 4 Claims, 3 Drawing Figs.
[52] U.S. Cl 235/193, 235/184, 356/177 [51 Int. Cl G06g 7/48, G0 1 j 3/46 [50] Field 01 Search 235/193, 184, 185; 356/177, 173
[56] References Cited UNITED STATES PATENTS 3,018,050 1/1962 Barrell 235/193 RE FEHENCE SOURCE COMPUTATION 3,270,190 8/1966 Lambert 235/184 X 3,329,808 7/1967 Fisher 235/193 3,406,281 10/1968 Buchanan et a1. 235/193 Primary Examiner-Joseph F. Ruggiero Attorney- Fishbum, Gold and Litman ABSTRACT: Electrical apparatus for obtaining density values for a filter pack for use with a production color film by comparing density values of a standard color film and its filter pack with the production color film, said apparatus having visual indicators for displaying the obtained net density values for the filter pack for the production color film. A computation circuit is electrically connected to the visual indicators and to a standard color film circuit and to a pack control circuit and to a production color film circuit for electrically processing signals from a plurality of potentiometers in the respective circuits. The signals correspond to density values associated with the respective item recorded therein whereby when the computation circuit is activated, numerical density values for the filter pack for the production color film are displayed by the visual indicators.
POWER SOURCE.
PATENTED UEB28 am SHEET 1 or 2 INVENTORS. JOHN V. HANUNE n DAN\EL M. CHAPIN zal-lm gr o m ATTORNEYS ELECTRICAL APPARATUS FOR OBTAINING FILTER PACK DENSITY VALUES The present invention relates to photographic apparatus and more particularly to electrical apparatus for comparing density values of a standard color film and its filter pack with density values of a production color film to obtain density values for a filter pack for use with the production color film.
The principal objects of the present invention are: to provide an electrical apparatus for simultaneously determining and visually displaying net density values for a subtractive filter pack for use with a production color film; to provide such an electrical apparatus adapted to compare respective density values of a standard color film and a filter pack associated therewith with density values of a production color film to obtain density values for a filter pack for use with the production color film; to provide such an electrical apparatus adapted to provide results equal to solution of the equation D,-D ,,+P,I*J.D.=P wherein D and D are red and green and blue density values of the standard color film and the production color film respectively and P and P are the green and blue density values of a filter pack for use with the standard color film and the production color film respectively and ND. is neutral density; and to provide such an electrical apparatus which is economical to manufacture, easily maintained, positive and direct in operation, and particularly well suited for the proposed use.
Other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawings wherein are set forth by way of illustration and example certain embodiments of this invention.
F IG. 1 is a perspective view of a cabinet containing an electrical apparatus for obtaining density values for a production filter pack embodying features of the present invention.
F IG. 2 is a wiring diagram of the electrical apparatus for obtaining the filter pack density values with the essential operating parts diagrammatically shown.
FIG. 3 is a detailed wiring diagram of a computation circuit for the electrical apparatus.
Referring more in detail to the drawings:
The reference numeral 1 generally designates a cabinet for containing electrical apparatus 2 for obtaining density values for a filter pack (not shown) for use with a production color film (not shown). The electrical apparatus 2 has a plurality of adjustable potentiometers, each adapted to produce a signal having a coded value responsive to adjustment thereof and a computation circuit 3 electrically connected to the potentiometers for processing the signals therefrom. The electrical apparatus 2 has visual indicators 4 and 5 electrically connected to the computation circuit 3 for displaying numerical values corresponding to results of processing the potentiometer signals with the numerical values displayed corresponding to density values of the filter pack for the production color film. A computation reference source 6 is electrically connected to the potentiometers and is adapted to produce a reference signal of substantially constant intensity for generating precise potentiometer signals.
Potentiometers 7, 8 and 9 are arranged in a standard color film circuit 10. The potentiometers 7, 8 and 9 are adjusted by knobs ll, 12 and 13 respectively, each of which has dials 14 for visually displaying numerical values corresponding to the adjustment of the respective potentiometers. In the illustrated electrical apparatus, the dials 14 on the knobs ll, 12 and 13 display numerical values representing red, green and blue density values respectively of a standard color film or control film (not shown).
The potentiometers 7, 8 and 9 are mounted in series between conductors l5 and 16 which are electrically connected to the computation reference source 6 whereby, when the electrical apparatus 2 is activated by a pushbutton 17, the potentiometers 7, 8 and 9 will produce signals which correspond to the density values of red, green and blue respectively.
Potentiometers l8 and 19 are arranged in a pack control circuit 20 with the potentiometers l8 and 19 being adjusted by knobs 21 and 22, each of which have dials 23 for visually displaying green and blue net density values ofa filter pack (not shown) for the standard color film or control film. In the illustrated electrical apparatus 2, the potentiometers l8 and 19 are connected in series between conductors 24 and 25 which are also connected to the computation reference source 6 for producing signals representing the green and blue net density values respectively of the filter pack for use with the standard control film.
The computation circuit 3 is adapted to electrically sum positive and negative signals from the red potentiometers 7 and 26 and from the green potentiometers 8, l8 and 27 and from the blue potentiometers 9, l9 and 28 to produce net signals for processing in the computation circuit 3.
The computation circuit 3 includes a portion to receive the net signal associated with the respective primary colors and has a red channel, green channel and blue channel respectively with a power source 36 electrically connected to operational amplifiers 37, 38 and 39 in the red, green and blue channels respectively. A conductor 40 extends between a neutral conductor 41 of the power source 36 and the operational amplifiers 37, 38 and 39 with resistors 42, 43 and 44 being electrically connected between conductor 40 and noninverting inputs of the operational amplifiers 37, 38 and 39 respectively. The resistors 42, 43 and 44 are each in the nature of 30 K0, Aw, or) 5 percent resistors.
A plurality of resistors 59 are connected to each of the respective operational amplification completion loops 50, 51 and 52 and are also in the nature of 200 K0, or 0.02 percent resistors.
The amplification completion loops 50, 5] and 52 are connected to output conductors 60, 61 and 62 respectively whereby voltage in the output conductor 60 corresponds to the integral red density (neutral density) of the filter pack for the production color film and the voltage in the output condoctors 61 and 62 corresponds to the integral net densities for the green and blue channels respectively. The red or neutral density is cancelled by the computation circuit 3 by electrically adding to the green and blue signals an electrical signal equivalent to but of opposite sign to the red or neutral density thereby eliminating red or neutral density.
A switch 63 is positioned on a cabinet front panel 64 and is movable between an on" and an off" position to supply electrical power to the computation reference source 6 and the power source 36. The computation reference source 6 is adapted to produce a substantially constant output reference signal, such as in the nature of l0.00 volts. Manipulation or adjustment of the various knobs varies respective resistances in the respective potentiometers whereby, when the reference signal passes through the respective potentiometers, a signal is produced having a value responsive to adjustment thereof with the potentiometer signals corresponding to respective density values. The potentiometer signals are electrically summed for each of the red, green and blue channels in computation circuit 3.
It is desirable to have the electrical apparatus 2 self-calibrating, therefore, a calibration circuit 65 is electrically connected to the computation circuit 3 and to the visual indicators 4 and 5.
The electrical apparatus 2 is adapted to provide results equivalent to those obtainable by solving the equation D D +P,l-1.D.=P wherein D is red, green and blue density values of the standard color film or control film and D is the red, green and blue density values of the production film. P is the green and blue density values of a filter pack for use with the control film and ND. is neutral density and it is preferably the lesser density value of the red, green and blue density values and in the illustrated electrical apparatus, red has been selected as the neutral density to accommodate other printing operations. P is the desired density values for a filter pack for use with the production color film and P, is the density values displayed on the visual indicators 4 and 5 respectively.
A color print is made from the standard color film or the control film and the density values of the standard color film and the filter pack used therewith for making the color print are obtained by using a densitometer. The density values for the standard color film and its filter pack are placed in the electrical apparatus 2 by adjusting the potentiometers 7, 8 and 9 and the potentiometers l8 and 19 whereby the dials l4 display values corresponding to the red, green and blue density values of the standard color film on the knobs l1, l2 and 13 respectively and the dials 23 display the density values of the filter pack on the knobs 21 and 22 respectively. A production color film from which it is desired to make a color print having color characteristics corresponding to the color print made from the standard color film and its filter pack is placed in a densitometer to obtain the red, green and blue density values thereof which are then placed in the electrical apparatus 2 by adjustment of the potentiometers 26, 27 and 28 respectively. The pushbutton 17 is depressed to activate the computation circuit 3 which processes the signals from the respective potentiometers in the circuits 10, 20 and 29 to visually display numerical values on the visual indicators 4 and 5 corresponding to density values for a filter pack for use with the production color film having the density values corresponding to the signals produced by the potentiometers 26, 27 and 28.
It is to be understood that while we have illustrated and described one form of our invention, it is not to be limited to the specific form or arrangement of parts herein described and shown.
What we claim and desire to secure by Letters Patent is:
1. Electrical apparatus for obtaining density values for a production filter pack for use in making a print from a production color film, the electrical apparatus comprising:
a. a plurality of adjustable potentiometers each operative to produce a signal having a value responsive to adjustment thereof;
b. a plurality of circuits each having a plurality of said potentiometers therein arranged in a plurality of channels; said potentiometers being arranged in a color film density circuit and a pack control circuit and a production color film density circuit, said potentiometers in said color film density circuit being operative to produce signals representing selected density values of a control color film, said potentiometers in said pack control circuit being operative to produce signals representing selected density values of a filter pack for use with the control color film in making a print therefrom, said selected densit values of a production color film, said density values emg for the primary colors of red and green and blue for said color film density circuit and said production color film density circuit, said density values being for the primary colors of green and blue for said pack control circuit and for the filter pack for the production color film;
c. a computation circuit electrically connected to said potentiometers in said channels of said circuits for processing said signals therefrom, said computation circuit being operative to electrically sum said potentiometer signals for each of the respective colors and electrically cancel one of the respective colors from said electrical summation, said computation circuit including an operational amplifier for the channel for each of said primary colors and balancing means electrically connected to each of said operational amplifiers for balancing current therethrough and circuit noise reduction means electrically connected to each of said operational amplifiers and a plurality of resistors electrically connected to each of said operational amplifiers;
d. electric power means electrically connected to said computation circuit for activating same;
e. a plurality of visual indicators electrically connected to said computation circuit for displaying numerical values representing results of processing the potentiometer signals, said numerical 'values representing density values for a filter pack for use in making a print from a production color film; and
f. a computation reference source operative to produce a reference signal of substantially constant intensity for comparing each potentiometer signal therewith.
2. An electrical apparatus as set forth in claim 1 wherein:
a. said potentiometers are each digitally coded switches to correspond to said respective density values; and
b. said computation circuit processes said digitally coded signals in a digital manner.
3. An electrical apparatus as set forth in claim 2 including display means operatively connected to each of said digitally coded switches for displaying numerical values representing adjustment of said respective digitally coded switches, said numerical values representing respective density values of the standard color film and the filter pack therefor and the production color film.
4. An electrical apparatus for obtaining numerical density values for a production filter pack for use in making a print from a production color film, the electrical apparatus comprising:
a. a plurality of adjustable potentiometers each operative to produce a signal having a value responsive to adjustment thereof;
b. a plurality of circuits each having a plurality of said potentiometers therein arranged in a plurality of channels;
c. a computation circuit electrically connected to each of said potentiometers in each of said channels of each of said circuits for processing said signals therefrom;
d. electric power means electrically connected to said computation circuit for activating same;
e. a plurality of visual indicators electrically connected to said computation circuit for displaying numerical values representing results of processing the potentiometer signals, said numerical values representing density values for a filter pack for use in making a print from a production color film; and
f. a calibration circuit electrically connected to said computation circuit and to each of said visual indicators whereby the electrical apparatus is self-calibrating.
Claims (4)
1. Electrical apparatus for obtaining density values for a production filter pack for use in making a print from a production color film, the electrical apparatus comprising: a. a plurality of adjustable potentiometers each operative to produce a signal having a value responsive to adjustment thereof; b. a plurality of circuits each having a plurality of said potentiometers therein arranged in a plurality of channels; said potentiometers being arranged in a color film density circuit and a pack control circuit and a production color film density circuit, said potentiometers in said color film density circuit being operative to produce signals representing selected density values of a control color film, said potentiometers in said pack control circuit being operative to produce signals representing selected density values of a filter pack for use with the control color film in making a print therefrom, said potentiometers in said production color film density circuit being operative to produce signals representing selected density values of a production color film, said density values being for the primary colors of red and green and blue for said color film density circuit and said production color film density circuit, said density values being for the primary colors of green and blue for said pack control circuit and for the filter pack for the production color film; c. a computation circuit electrically connected to said potentiometers in said channels of said circuits for processing said signals therefrom, said computation circuit being operative to electrically sum said potentiometer signals for each of the respective colors and electrically cancel one of the respective colors from said electrical summation, said computation circuit including an operational amplifier for the channel for each of said primary colors and balancing means electrically connected to each of said operational amplifiers for balancing current therethrough and circuit noise reduction means electrically connected to each of said operational amplifiers and a plurality of resistors electrically connected to each of said operational amplifiers; d. electric power means electrically connected to said computation circuit for activating same; e. a plurality of visual indicators electrically connected to said computation circuit for displaying numerical values representing results of processing the potentiometer signals, said numerical values representing density values for a filter pack for use in making a print from a production color film; and f. a computation reference source operative to produce a reference signal of substantially constant intensity for comparing each potentiometer signal therewith.
2. An electrical apparatus as set forth in claim 1 wherein: a. said potentiometers are each digitally coded switches to correspOnd to said respective density values; and b. said computation circuit processes said digitally coded signals in a digital manner.
3. An electrical apparatus as set forth in claim 2 including display means operatively connected to each of said digitally coded switches for displaying numerical values representing adjustment of said respective digitally coded switches, said numerical values representing respective density values of the standard color film and the filter pack therefor and the production color film.
4. An electrical apparatus for obtaining numerical density values for a production filter pack for use in making a print from a production color film, the electrical apparatus comprising: a. a plurality of adjustable potentiometers each operative to produce a signal having a value responsive to adjustment thereof; b. a plurality of circuits each having a plurality of said potentiometers therein arranged in a plurality of channels; c. a computation circuit electrically connected to each of said potentiometers in each of said channels of each of said circuits for processing said signals therefrom; d. electric power means electrically connected to said computation circuit for activating same; e. a plurality of visual indicators electrically connected to said computation circuit for displaying numerical values representing results of processing the potentiometer signals, said numerical values representing density values for a filter pack for use in making a print from a production color film; and f. a calibration circuit electrically connected to said computation circuit and to each of said visual indicators whereby the electrical apparatus is self-calibrating.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US80135069A | 1969-02-24 | 1969-02-24 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US3631234A true US3631234A (en) | 1971-12-28 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US801350A Expired - Lifetime US3631234A (en) | 1969-02-24 | 1969-02-24 | Electrical apparatus for obtaining filter pack density values |
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| Country | Link |
|---|---|
| US (1) | US3631234A (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3018050A (en) * | 1958-04-29 | 1962-01-23 | Westinghouse Electric Corp | Economic data computer |
| US3270190A (en) * | 1962-10-01 | 1966-08-30 | Electronic Stock Evaluator Cor | Securities evaluator |
| US3329808A (en) * | 1963-04-08 | 1967-07-04 | Sperry Rand Corp | Cargo loading computer |
| US3406281A (en) * | 1964-10-05 | 1968-10-15 | North American Rockwell | Profit analysis computer |
-
1969
- 1969-02-24 US US801350A patent/US3631234A/en not_active Expired - Lifetime
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3018050A (en) * | 1958-04-29 | 1962-01-23 | Westinghouse Electric Corp | Economic data computer |
| US3270190A (en) * | 1962-10-01 | 1966-08-30 | Electronic Stock Evaluator Cor | Securities evaluator |
| US3329808A (en) * | 1963-04-08 | 1967-07-04 | Sperry Rand Corp | Cargo loading computer |
| US3406281A (en) * | 1964-10-05 | 1968-10-15 | North American Rockwell | Profit analysis computer |
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