Of Photographic Film Patents (Class 356/443)
  • Patent number: 4906835
    Abstract: A light sensor for use to detect only light above a given frequency uses as its light sensitive element a light emitting diode. The L.E.D. is one which, if it were arranged to emit light, would emit light having a maximum frequency equal to the said given frequency.In combination with such a sensor another L.E.D. can be used having a maximum emission frequency below the said given frequency to illuminate an area without affecting the light sensor.
    Type: Grant
    Filed: July 29, 1988
    Date of Patent: March 6, 1990
    Assignee: The General Electric Company, p.l.c.
    Inventor: Peter J. Betts
  • Patent number: 4897678
    Abstract: A mensuration apparatus for converting film images and paper drawings into digital photogrammetric arrays to be computer processed, displayed, mensurated and analyzed. This mensuration apparatus includes a table on which a translatable camera and a reseau assembly are mounted. The reseau assembly includes an object mounting plate for mounting an object such as a photograph, map, or the like, and a grid mark system for superimposing grid marks on the object. The translatable camera includes a solid state camera having a two-dimensional array of light sensor elements mounted over the reseau assembly in a translatable mounting apparatus. Said translation camera can be moved to any desired position over the reseau assembly, as well as toward and away from the reseau assembly, forming three coordinate systems, which are correlated together for precise mensuration of an object image digitized by the solid state camera.
    Type: Grant
    Filed: August 3, 1987
    Date of Patent: January 30, 1990
    Assignee: Vexcel Corporation
    Inventors: Franz W. Leberl, Dana Meyer, Scott Lee
  • Patent number: 4812411
    Abstract: The method in accordance with the invention provides antibiograms or bacteriological identification of colonies of micro-organisms. The method uses a cabinet (1) which supports a set of mechanical, thermal, optical, and electronic units, together with conditioning strips in which the various biochemical reactions take place. After being seeded with a micro-organism under investigation, a strip is placed on the cabinet and is then subjected to a sequence of mechanical, thermal, and optical operations.
    Type: Grant
    Filed: December 16, 1985
    Date of Patent: March 14, 1989
    Inventor: Jean Guigan
  • Patent number: 4687943
    Abstract: A motion picture film flaw detection system wherein a single inspection location is employed at which sound track side edge defects, sprocket hole side edge defects, thickness variations, and defective sprocket holes are analyzed by optical sensors so that no physical contact on the film by feeler arms or the like occurs. Film wear such as by scratching and rubbing is reduced since minimal contact occurs with a surface of the film as it travels through the system. The sprocket holes are analyzed by optics which provide a real image on a projection plane at which location excessive elongation of the sprocket holes is checked. Detection circuits are provided connecting to the optical sensors which derive a reference which automatically tracks averaged or weighted overall signal levels for comparison to signal variations caused by film thickness changes or film flaws. Accordingly, variations in optical system performance are automatically compensated for.
    Type: Grant
    Filed: January 18, 1985
    Date of Patent: August 18, 1987
    Assignee: Research Technology International
    Inventors: Howard Bowen, David Henderson, Carl Olson
  • Patent number: 4673807
    Abstract: This invention relates to an automatic range control method for a compact and portable optical density/dot percentage measuring device which can use a conventional light table as its light source, and which can digitally display a result of measurement. In the method, information obtained from an A/D converter, which converts a measured analog signal to a digital signal, is positively employed for reducing overall measuring time. An A/D conversion is first made at x1 range by a 10 bit A/D converter. The A/D conversion value is compared with predetermined values to determine a gain to be selected and perform further A/D conversion.
    Type: Grant
    Filed: October 8, 1985
    Date of Patent: June 16, 1987
    Assignee: Dai Nippon Insatso Kabushiki Kaisha
    Inventors: Yuji Kobayashi, Norio Takahashi
  • Patent number: 4669885
    Abstract: Disclosed is an apparatus for inspecting negatives which is provided with a laser beam generating source, a scanner for scanning the laser beam, a holding device for holding a negative having a pattern formed in a reflective area on a first surface of a transparent plate and transferring the negative in a direction perpendicular to the scanning direction of the laser beam, a first converging lens for converging the laser beam on said first surface, a second converging lens for converging on a first photocell the beam transmitted through the negative, a third converging lens for converging on a second photocell the beam reflected by the first surface of the negative, and a comparator for comparing a first signal stream put out from the first photocell and a second signal stream put out from the second photocell and detecting an undesirable adhering matter.
    Type: Grant
    Filed: March 17, 1983
    Date of Patent: June 2, 1987
    Assignee: Canon Kabushiki Kaisha
    Inventor: Hideki Ina
  • Patent number: 4666307
    Abstract: In a photographic image information detecting method of the type in which light transmitted from an original film is received by a two-dimensional image sensor and image information is detected with respect to the divided a plurality of picture elements of the original film, a photographic image information is calibrated by the steps of detecting information of the photographic image of a reference film with respect to the original film in use of the two-dimensional image sensor, storing the thus detected information as data for calibration, and subtracting the data for calibration from the detected data regarding the image information of the original film so as to thereby obtain accurately calibrated information regarding the photographic image of the original film.
    Type: Grant
    Filed: January 14, 1985
    Date of Patent: May 19, 1987
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Fumio Matsumoto, Kenji Nakauchi, Hideaki Iijima
  • Patent number: 4645351
    Abstract: A method and apparatus for discriminating a surface of a developed film focuses a picture pattern on a film disposed at a reference position. One or two sensors are then located at focused positions of the picture pattern of the film when the front surface of the film is at the reference position and when the back surface of the film is at the reference position, respectively. The two resultant sensor outputs are then band-pass filtered to extract the portions of the outputs within a predetermined frequency range. The resultant outputs are then rectified and integrated and then compared by a comparator whose outputs is a first value when the front surface of the film is at the reference position and is a second different value when the back surface of the film is at a reference position.
    Type: Grant
    Filed: May 23, 1984
    Date of Patent: February 24, 1987
    Assignee: Fuji Photo Film Co., Ltd.
    Inventor: Yasuhiro Seto
  • Patent number: 4646252
    Abstract: In printing color films, a color negative film has to be evaluated to determine the amount of exposure. A color balance adjusting apparatus has hitherto been used for appraisal. In the prior art, however, as all the picture images of a color negative film are displayed on a monitor TV for appraisal, it has a demerit in that a speedy inspection cannot be carried out. In addition, as the film picture images are displayed through CRT images of a monitor TV, it is hard on the eyes compared with that by direct visual observation and, therefore, presents a drawback in processing capacity. Accordingly, this invention aims at providing a method which greatly improves the processing capacity of inspecting the color films.
    Type: Grant
    Filed: October 25, 1983
    Date of Patent: February 24, 1987
    Assignee: Fuji Photo Film Co., Ltd.
    Inventor: Takaaki Terashita
  • Patent number: 4642456
    Abstract: A double sheet detection method and apparatus for a sheet-fed rotary press is proposed wherein a theoretical reference value is set as a difference between an intermediate value between a first theoretical amount of light transmitted through one sheet and a second theoretical amount of light transmitted through two sheets and the first theoretical amount of light; the theoretical reference value is stored in correspondence with the amount of light transmitted through a sheet; a difference is calculated between an amount of light transmitted through an nth sheet and an amount of light transmitted through an (n+1)th sheet when actual printing is performed; the theoretical reference value which corresponds to the amount of light transmitted through the nth sheet and which is defined as an actual reference value is read out; the difference calculated when actual printing is performed is compared with the actual reference value; and double sheet detection is performed in accordance with a comparison result.
    Type: Grant
    Filed: March 25, 1985
    Date of Patent: February 10, 1987
    Assignee: Komori Printing
    Inventor: Hideo Watanabe
  • Patent number: 4641019
    Abstract: An automatic notcher which automatically forms a notch on a developed film is provided with a faulty frame judging device and a notcher controlling circuit. The device includes out-of-focus image judging device for making judgement as to whether or not an image on the film is out of focus. The notcher controlling circuit actuates a notcher only for frames which need to be printed on the basis of the judgement made by the out-of-focus image judging device. Accordingly, any out-of-focus image on the film is automatically judged to be one which need not be printed and a notch is not therefore formed for it.
    Type: Grant
    Filed: June 3, 1985
    Date of Patent: February 3, 1987
    Assignee: Fuji Photo Film Co., Ltd.
    Inventor: Kenichi Inatsuki
  • Patent number: 4603956
    Abstract: A replenishment control system for a graphic arts continuous-tone film processor includes a scanner which scans a light spot across the film transport path and a sensor bar for receiving the light spot. The output of the sensor bar is periodically sampled during each scan of the light spot to produce a plurality of sample values for scan. Each sample value is then converted to a density value, and the density values are summed to produce an integrated density. Replenishment control signals for developer and fix replenishment are produced as a function of the integrated density.
    Type: Grant
    Filed: November 16, 1984
    Date of Patent: August 5, 1986
    Assignee: Pako Corporation
    Inventor: Richard W. Baker
  • Patent number: 4591271
    Abstract: A primary beam of light is directed against the surface of a piece of material under conditions predetermined to generate a secondary beam by either transmission through the piece or reflection from the surface thereof. The secondary beam is directed against means for measuring the intensity of the transmitted or reflected light and the light intensity measured. The procedure is repeated on a different surface of the piece and the results compared. This gives an evaluation of the surface and a determination of the presence, absence, or condition of any coating which may be present on the surface. The apparatus of the invention comprises means for achieving the foregoing functions.The method and apparatus are of particular application in the determination of which is the coated side of an object, such as a photographic film, or a coated lens.
    Type: Grant
    Filed: March 21, 1983
    Date of Patent: May 27, 1986
    Inventor: Donald W. Byers
  • Patent number: 4588298
    Abstract: A step tablet with which an amount of exposure or degree of exhaustion of a developing solution can very readily been determined. The step chart is composed of a number of rectangular patches of photosensitive material, arranged in an order of sensitivity. The steps are each marked with two indicia, one having an optical density corresponding, upon development, of a step of minimum optical density, while the other corresponds to a step of maximum optical density.
    Type: Grant
    Filed: December 1, 1983
    Date of Patent: May 13, 1986
    Assignee: Fuji Photo Film Co., Ltd.
    Inventor: Masao Nakamura
  • Patent number: 4575251
    Abstract: In a measurement device of photographic density of a film wherein a light source is provided on one side over a film carrier route and a plurality of light receiving elements for converting transmitted light of a film emitted from the said light source to an electrical signal are provided on the counter side of the light source forming a line, a device for measuring photographic density of the film comprising a means for obtaining a rate of change in the form of a ratio between a reference signal decided beforehand for each of the light receiving elements and an output signal of the light receiving elements when the film is carried, and a means for obtaining photographic density of the film in accordance with the obtained ratio.
    Type: Grant
    Filed: November 16, 1983
    Date of Patent: March 11, 1986
    Assignee: Dainippon Screen Mfg. Co., Ltd.
    Inventors: Tomiji Hotta, Mitsuo Inoue
  • Patent number: 4568184
    Abstract: A reader card for use in densitometric test analysis wherein a film having data recorded as spots thereon is supported by and retained on a base card, the reader card further having an area for use in establishing initial conditions for the optical system of the densitometer and a series of borders for indicating the relative position of the film on the card to the optical system of the densitometer. In a preferred embodiment, the reader card includes a base card having an opening therethrough, and an overlay thereover. The overlay retains the film in place and includes a black band covering the film, the black band having windows therethrough for observing and measuring the spots.
    Type: Grant
    Filed: April 8, 1983
    Date of Patent: February 4, 1986
    Assignee: Mast Immunosystems Ltd.
    Inventors: Gary B. Krantz, Christopher A. Conde
  • Patent number: 4568185
    Abstract: A measuring table for facilitating the accurate densitometric measurement of a measuring field strip on a paper sheet is disclosed. The table carries a removable hold-down plate that is positioned between side stop rails and a registering rail. The hold-down plate is held in place on the table by cooperating electromagnets and ferromagnetic metal disks and holds a sheet of paper in place between the plate and the table's surface. The hold-down plate also includes a measuring slot so that a densitometer positioned on the upper surface of the plate is afforded optical access to the measuring field strip imprinted on the paper sheet.
    Type: Grant
    Filed: May 20, 1983
    Date of Patent: February 4, 1986
    Assignee: Koenig & Bauer Aktiengesellschaft
    Inventor: Dieterich R. K. Leuerer
  • Patent number: 4557604
    Abstract: A meter for measuring the transmissivity of a floppy disk including an oscillator for generating a sinusoidal signal, a driver and an LED, biased on by the driver and modulated by the driver responsive to the sinusoidal signal, the LED for illuminating a portion of a surface of the disk. The meter further including a photodetector optically aligned with the LED and so disposed as to develop a detected signal from illumination transmitted through the disk, a current to voltage converter, an amplifier, a state variable band pass filter, and a peak detector and amplifier for amplifying, filtering and detecting the detected signal to develop a signal suitable for driving a digital panel meter so as to directly indicate in percent the transmissivity of the disk.
    Type: Grant
    Filed: December 26, 1979
    Date of Patent: December 10, 1985
    Assignee: Verbatim Corporation
    Inventor: Russell L. Gephart
  • Patent number: 4533253
    Abstract: A device for measuring density of photographic transparencies, such as recorded photographic film, which is generally used in a color scanner system in which a photographic film carrying a colored image is scanned in X and Y directions with a light beam, so-called "flying spot", and the transmitted beam is separated into a plurality of component color beams which are then converted into electric signals indicative of densities of the respective component colors, which are then adequately adjusted in magnitude and utilized for preparation of multi-color printing blocks, the device having means for correcting density errors relating to polarization characteristics of the material of the film.
    Type: Grant
    Filed: September 7, 1982
    Date of Patent: August 6, 1985
    Assignee: Konan Camera Research Institute
    Inventor: Takeshi Okano
  • Patent number: 4527878
    Abstract: A method and apparatus for controlling the activity of a developing solution against oxidation by using a test piece for use in an automatic developer. Differences N.sub.4 -N.sub.4 ' and N.sub.5 -N.sub.5 ' between first and second standard densities N.sub.4 and N.sub.5 measured at first and second points of a first test piece developed in a standard developing solution and first and second densities N.sub.4 ' and N.sub.5 ' measured at the same points of a second test piece of the same type as the first one as the same points of the first test piece, developed in a developing solution to be controlled, are obtained. An operating time T of constant-flow supplementing means is calculated according to a formula T=K.sub.1 [K.sub.3 (N.sub.4 -N.sub.4 ')-(N.sub.5 -N.sub.5 ')]+K.sub.2 wherein K.sub.1, K.sub.2 and K.sub.
    Type: Grant
    Filed: July 6, 1982
    Date of Patent: July 9, 1985
    Assignee: Dainippon Screen Seizo Kabushiki Kaisha
    Inventors: Hiroshi Taniguchi, Nobuhiro Takita, Norimasa Nomura, Masaji Mizuta
  • Patent number: 4518234
    Abstract: The method for reproducing at least one colored surface the color of which corresponds to a reference chosen from a color chart is characterized by the fact that during a first stage, there is recorded on a photographic emulsion of the same type a sensitogram developed by means of developing materials of predetermined characteristics, a densitometric analysis of said developed sensitogram is made and the results of said analysis recorded so as to establish an analytical record of the colors comprising the sensitometer with respect to the photographic emulsion and the developing products used. During a second stage, the exposure conditions for the photographic emulsion are determined to reproduce the color chosen from the color chart as a function of the information registered on the analytical record of the colors of the sensitogram. The apparatus used in this process comprises essentially an exposure unit (11), a sensitometer (16) and a central control unit (22).
    Type: Grant
    Filed: November 30, 1983
    Date of Patent: May 21, 1985
    Inventor: Jean-Claude Lamere
  • Patent number: 4464036
    Abstract: A method and apparatus for controlling the activity of a developing solution against blackening by using a test piece for use in an automatic developer are disclosed. A difference between a standard density measured at the predetermined point of the first test piece developed in a standard developing solution, and a density measured at the same point of the second test piece of the same type as the first test piece as said predetermined point of the first test piece, developed in a developing solution to be controlled, is obtained. Then, a predetermined factor is multiplied by the thus obtained density difference to obtain a control value, and then the activity of the developing solution is controlled according to the control value, such as adding a supplementary solution against the blackening to the developing solution to be controlled or putting an exposed film into the same. A permissible density difference range may be determined, in which no activity control is performed.
    Type: Grant
    Filed: July 6, 1982
    Date of Patent: August 7, 1984
    Assignee: Dainippon Screen Seizo Kabushiki Kaisha
    Inventors: Hiroshi Taniguchi, Nobuhiro Takita, Norimasa Nomura, Masaji Mizuta
  • Patent number: 4419426
    Abstract: The present invention relates to a method and to elements for the execution of the method for the inspection of the reproduction quality of drawing elements which are exposed by means of a cathode ray tube on light-sensitive photo material. A simple and feasible development of the quality control of exposed photo material or other printing masters produced in this manner is achieved. The inspection ensues in that additional raster points are exposed which behave differently in response to different exposure and development conditions.
    Type: Grant
    Filed: March 5, 1982
    Date of Patent: December 6, 1983
    Assignee: Dr. -Ing. Rudolf Hell GmbH
    Inventor: Christof Kehl
  • Patent number: 4388389
    Abstract: A high pressure mercury arc lamp such as the light source in a projection aligner is utilized in a photo resist calibrating process. The light source is utilized with narrow band interference filters centered on the mercury emission lines to isolate exposures to one narrow band of wave length at a time. The assumption is made (incorrectly) that the energy in each band of wave lengths from the high pressure mercury arc lamp is equal. Exposure to a narrow strip of photo resist--preferably in the form of a bar graph--on a semi-conductor wafer is made. A single wave length band is exposed for each bar of the graph. As each bar of the graph is scanned, exposure is varied in known ways (eg. linearly variable neutral density filters, changing apertures size, and/or varying exposure from changing wafer motion). The wafer is then developed and examined to determine the ratio of sensitivity for each wave length. A light meter is then placed in and exposed to the same high pressure mercury arc lamp.
    Type: Grant
    Filed: November 16, 1981
    Date of Patent: June 14, 1983
    Inventor: Nathan Gold
  • Patent number: 4370558
    Abstract: An amplification-factor of the amplifier is controlled so as the output from a film-detecting-mechanism to be supplied as the input into a subtractor is adjusted fitting to a reference signal-prior to the film-insertion into the detecting mechanism. The output-signal from a comparator is supplied into the amplification-factor-variable-amplifier, in which the amplification-factor is controlled depending on the magnitude of the input-signal, and it is kept at the controlled value.Or an intensity of a light source is controlled so as the output from the film detecting mechanism to be supplied as the input into the subtractor is adjusted fitting to the reference-signal prior to the film-insertion into the detecting mechanism.
    Type: Grant
    Filed: April 13, 1981
    Date of Patent: January 25, 1983
    Assignee: Dainippon Screen Mfg. Co., Ltd.
    Inventors: Minoru Kinoshita, Masaji Mizuta
  • Patent number: 4302099
    Abstract: A Programmable Computing Enlarging Exposure Meter determines printing and contrast grades and shadow speeds and contrast grades of photosensitive material measuring printing density and contrast of film in its light path, with its unique analog computer it determines the necessary contrast grade and the exposure time required to produce a print of the necessary density. All computations and determinations are performed internally without requiring user extrapolating in the dark with calculator dials and attached slide rules that are the practice with instruments designed for the purpose.The structure comprises a power supply, light measuring device, a light to voltage converter for converting the light measurement to one or more linearly proportional voltages having range of 1:10 between them.An operational amplifier produces fixed output voltage. An R.sub.1 inverting input variable log taper resistor calibrated against the paper speed and paper grade scales on the front panel, an R.sub.
    Type: Grant
    Filed: June 26, 1979
    Date of Patent: November 24, 1981
    Inventor: Stanley J. Gewirtz
  • Patent number: 4295727
    Abstract: This invention is directed to a new apparatus to assist in the making of negatives. If the negatives are screen separation negatives, then the screen separation negatives can be used in the making of printing plates. For colored prints there are a plurality of screen separation negatives and a plurality of printing plates. With this apparatus it is possible to develop a screen separation negative to realize a predetermined dot structure. As a result, in a plurality of screen separation negatives there is a more uniform dot structure. With a more uniform dot structure in the screen separation negative there is a more uniform dot structure in the printing plate and therefore a more uniform printed color print. The apparatus indicates when the dot structure, viz., opaque area and clear area, on the developing screen separation negative reaches a predetermined standard for dot structure or a predetermined standard of transparency to light.
    Type: Grant
    Filed: October 17, 1978
    Date of Patent: October 20, 1981
    Inventor: Douglas K. Robinson
  • Patent number: 4293226
    Abstract: A photographic film blackened area measuring device, having two rod shaped light conducting members, each of which is formed as an elongated piece of transparent material with part of its surface, parallel to its axis, being roughened so as to diffuse light, while light is totally internally reflected along the length of the rod shaped member from the remainder of its smooth surface. These rod shaped light conducting members are arranged one on each side of a piece of developed photographic film in a automatic film developing machine, and the film passes between them. A light emitting device is provided at one end of one of the rod shaped light conducting members, and a photo sensitive device is provided at the end of the other rod shaped light conducting member which is remote from the light emitting device.
    Type: Grant
    Filed: May 19, 1980
    Date of Patent: October 6, 1981
    Assignee: Dainippon Screen Seizo Kabushiki Kaisha
    Inventors: Minoru Kinoshita, Kiyoshi Sugou, Yukio Onoda
  • Patent number: 4266872
    Abstract: A dot film is irradiated by light, so that the quantity of light in the long wavelength region and the quantity of light in the short wavelength region are obtained from the light passed through the dot film. The amount of reduction of the dot film is calculated from the difference between the two quantities of light, and is displayed on a display section.
    Type: Grant
    Filed: April 9, 1979
    Date of Patent: May 12, 1981
    Assignee: Dai Nippon Insatsu Kabushiki Kaisha
    Inventor: Yuuji Mitsuhashi
  • Patent number: 4239395
    Abstract: The present invention is an apparatus and a method for using the apparatus to maintain quality control over a radiographic imaging system by precisely exposing two areas of a film to even illumination from a light source attenuated by different precisely known amounts. Both exposures are chosen to fall on the linear portion of the film's density-log exposure curve. The film is developed and the densities of the exposed areas are sensed photometrically. The film's base plus fog density, gamma and "processor quality factor" (which is a measure of the sensed film's deviation from the gamma and speed of a reference film processed in a reference processor) are automatically calculated. The processor quality factor allows faulty radiographic technique to be detected apart from faulty film or faulty processing without re-exposing the patient to additional radiation.
    Type: Grant
    Filed: August 7, 1978
    Date of Patent: December 16, 1980
    Inventor: James E. Modisette
  • Patent number: 4229107
    Abstract: In a preferred embodiment of the present invention, method and apparatus are provided for converting an input light intensity representing an optical density to a standard industry scale reading. A photomultiplier tube is operated with a constant anode current corresponding to a reference, or "white" sample, and the dynode voltages varied to obtain the constant anode current. The resulting dynode voltage forms a signal linearly related to the input light intensity. A reference exponential characteristic is selected from an envelope of such characteristics, the selected characteristic cooperating with the photomultiplier tube characteristics. The exponential characteristic envelope may be conveniently formed by resistor-capacitor decay circuits with charging and discharging characteristics compatible with the range of photomultiplier tube parameters to be accommodated, where the envelope curve boundaries cross at a selected reference point.
    Type: Grant
    Filed: June 8, 1978
    Date of Patent: October 21, 1980
    Assignee: Graphic Arts Manufacturing Company
    Inventor: Warren Childers
  • Patent number: 4229108
    Abstract: In a preferred embodiment of the present invention, an optical densitometer is provided having an improved output scale resolution. An output scale reading from 0.000 to 4.000, having a resolution to 0.001, is obtained by improved method and apparatus for obtaining the reference operating characteristics for "zero-mode" parameters. An analog reference anode signal is formed by making adjustments in a generally antilogrithmic relationship to the difference between the reference anode signal being generated and the anode signal produced under the zero-mode conditions. The antilogrithmic relationship improves scale resolution near the zero point and increases densitometer stability during a subsequent measurement cycle. The combination analog reference anode signal generating circuit and an improved exponential characteristic selection circuit enables the improved output resolution and accuracy to be obtained.
    Type: Grant
    Filed: June 8, 1978
    Date of Patent: October 21, 1980
    Assignee: Graphic Arts Manufacturing Company
    Inventor: Warren Childers
  • Patent number: 4204766
    Abstract: Method and apparatus for detecting and controlling the concentration of active toner particles in a liquid developer comprising taking a sample or proportion of liquid developer and subjecting it to an electrostatic field, measuring the toner particle concentration influenced by the field and correcting the concentration of effective toner particles in the developer by restoring said concentration to an acceptable predetermined level, and further measuring the concentration of degraded toner particles left in the liquid developer to determine if the entire developer is to be replaced.
    Type: Grant
    Filed: June 22, 1977
    Date of Patent: May 27, 1980
    Assignee: Konishiroku Photo Industry Co., Ltd.
    Inventor: Yoshiaki Harada
  • Patent number: 4199252
    Abstract: This invention relates to improvements in photographic printing exposure meters, and particularly to such a meter and having a light sensitive cell which produces an illuminance dependant electrical signal used in an electronic circuit, together with inputs of other parameters of printing density, to calculate values of printing density corresponding to the input values. The parameters inputs are related to contrast grade and speed index of photographic paper, and time duration of exposure to the illuminance given by the light sensitive cell. The meter can be used to determine what exposure time is required, for a photographic paper having a particular contrast grade and speed index, to give a particular value of printing density at the measured illuminance.
    Type: Grant
    Filed: September 20, 1978
    Date of Patent: April 22, 1980
    Inventor: Dirk J. Vermeulen
  • Patent number: 4194838
    Abstract: A photometric device for measuring and displaying by digital means primary color densities of a color negative to be printed to determine densities of color compensating filters. Exposure time, including reciprocity effect compensation for the photographic paper, is displayed digitally and determined by density measurements of the projected image.A reference area of a color negative illuminated by light through color compensating filters is projected on the aperture of a probe which directs light through a light guide to a photodetector. The resulting photocurrents generate voltages amplified by a first and second variable gain linear amplifier. The second amplifier provides primary color and exposure density reference by means of gains stored by measurement of a standard negative. Digital display means is provided to display memory gains for accurately modifying or resetting reference gains.
    Type: Grant
    Filed: February 22, 1977
    Date of Patent: March 25, 1980
    Inventors: Michael P. Bey, Paul P. Bey
  • Patent number: 4150894
    Abstract: An exposure control system for color printers having electro/optical means for spectral analysis of different types of original material for printing to determine different spectral coefficients for each material. Each coefficient is classified according to a reference range of values, each range being associated with a different original material. Photoelectric means are provided to determine the color densities of an original and a store stores sets of exposure parameters, each set being associated with a different original material. Automatic selection means responsive to the classification is provided to select whichever parameter set is associated with a coefficient reference range in which the coefficient has been classified during classification.
    Type: Grant
    Filed: January 27, 1978
    Date of Patent: April 24, 1979
    Assignee: Gretag Aktiengesellschaft
    Inventors: Armin Meyer, Jorg Muller, Bruno Brandli, Robert Wahli
  • Patent number: 4146798
    Abstract: An ink feed measuring device comprising a luminuous plate and a light receiving plate constructed so as to hold a photographic film of a printed matter between the two plates, the luminuous plate having one or more electro-luminescent plates and the light receiving plate having a plurality of photoelectric elements corresponding to the sectioned areas of the photographic film, wherein ink feed volume corresponding to each sectioned area of the photographic film is measured based on the amount of light transmitted through the sectioned areas of the film.
    Type: Grant
    Filed: March 1, 1977
    Date of Patent: March 27, 1979
    Assignee: Tokyo Kikai Seisakusho, Ltd.
    Inventors: Noriyuki Shiba, Shu Yoshida