US3620621A - Emulsion control - Google Patents

Emulsion control Download PDF

Info

Publication number
US3620621A
US3620621A US3620621DA US3620621A US 3620621 A US3620621 A US 3620621A US 3620621D A US3620621D A US 3620621DA US 3620621 A US3620621 A US 3620621A
Authority
US
United States
Prior art keywords
means
plate
emulsion
receiving means
light
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
Inventor
Ervin J Rachwal
Robert W Marculewicz
Douglas B Campbell
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
MATROGRAPHICS Inc
Original Assignee
MATROGRAPHICS Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by MATROGRAPHICS Inc filed Critical MATROGRAPHICS Inc
Priority to US79859669A priority Critical
Application granted granted Critical
Publication of US3620621A publication Critical patent/US3620621A/en
Assigned to FRAMINGHAM TRUST COMPANY reassignment FRAMINGHAM TRUST COMPANY RELEASED BY SECURED PARTY (SEE DOCUMENT FOR DETAILS). Assignors: SMALL BUSINESS ADMINISTRATION
Assigned to LAWYERS CO-OPERATIVE PUBLISHING CO. THE; AQUEDUCT ST., ROCHESTER, NY. 14694 A CORP OF NY. reassignment LAWYERS CO-OPERATIVE PUBLISHING CO. THE; AQUEDUCT ST., ROCHESTER, NY. 14694 A CORP OF NY. SECURITY INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: RACHWAL INDUSTRIES, INC.
Assigned to RACHWAL INDUSTRIES, INC. reassignment RACHWAL INDUSTRIES, INC. ASSIGNOR DOES HEREBY RELEASE ITS SECURITY INTEREST IN ASSIGNMENT RECORDED AUG. 19, 1982, AT REEL 4025, FRAME 0823 Assignors: LAWYERS CO-OPERATIVE PUBLISHING COMPANY, THE
Anticipated expiration legal-status Critical
Application status is Expired - Lifetime legal-status Critical

Links

Images

Classifications

    • GPHYSICS
    • G03PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03BAPPARATUS 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
    • G03B27/00Photographic printing apparatus
    • G03B27/32Projection printing apparatus, e.g. enlarger, copying camera
    • G03B27/52Details
    • G03B27/58Baseboards, masking frames, or other holders for the sensitive material
    • GPHYSICS
    • G03PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03BAPPARATUS 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
    • G03B27/00Photographic printing apparatus
    • G03B27/72Controlling or varying light intensity, spectral composition, or exposure time in photographic printing apparatus
    • G03B27/727Optical projection devices wherein the contrast is controlled optically (e.g. uniform exposure, two colour exposure on variable contrast sensitive material)

Abstract

An emulsion control for use in making plates for printing. An emulsion is used for receiving a photographic image which has a given sensitivity, which can be increased by controlling the humidity and temperature of the environment surrounding the plate, the voltage on the plate, and the light surrounding the plate to the extent that a certain threshold is not exceeded. This permits low intensity photographic images to trigger a necessary chemical action to produce an image on the plate.

Description

United States Patent [72] inventors Ervin J. Rachwal Framlngham.

Robert W. Marculewicz. Manchester; Douglas B. Campbell, Natlck, all of Mass.

Appl. No. 798,596

Filed Feb. 12, 1969 Patented Nov. I6, 1971 Assignee MatrographicsJnc New York, NY.

EMULSION CONTROL 5 Claims, 1 Drawing Fig.

US. Cl .l v 355/30, 355/67. 355/70 Int. Cl. v G03b 27/76 Field Search. 355/30. 67.

I 5 6 References Cited UNITED STATES PATENTS 233L335 l0/l943 Mayer Primary Examiner-Samuel S. Matthews Assistant Examiner-Richard A. Wintercorn 4uorney Kenneth S. Goldfarb SSS/70X ABSTRACT: An emulsion control for use in making plates for priming An emulsion is used for receiving a photographic image which has a given sensitivity. which can be increased by controlling the humidity and temperature of the environment surrounding the plate, the voltage on the plate, and the light surrounding the plate to the extent that a certain threshold is not exceeded This permits low intensity photographic images to trigger a necessary chemical action to produce an image on the plates PATENTEnuuv 1s l97l 3', 620 621 -II POWER SUPPLY INVENTORS R. W. MARCULEWICZ ERVIN RACHWAL D. B. CAMPBELL ATTORNEY EMULSION CONTROL BACKGROUND OF THE INVENTlON This invention relates to printing and more particularly the fabrication of plates which will be used in the printing process. In manufacturing plates a slide is projected onto a plate of aluminum which has an emulsion thereon. The projected image burns itself into the plate affixing an image thereto. Hy various steps of treatment the surface of the plate is made absorbent to ink in various degrees in accordance with the image that has been produced photographically on the plate. There are a great many techniques for producing images on the plate but all in common employ a lighbsensitive emulsion of a given sensitivity.

One of the difficulties in producing plates in accordance with the prior art methods was that the sensitivity of the plate was kept sufficiently low that they could be exposed to unfavorable conditions of light and in the platemaker inadvertent exposure to perhaps high room and machine temperatures and exposure to charged surfaces all of which would affect the sensitivity of the plate such that some of the chemicals of the emulsion may have been driven into activation which would obviously blur and destroy the image which would be subsequently placed thereon. Such a procedure is understandable and very desirable. However, if the sensitivity is too low, considerable amounts of light and its corollary time must be utilized in order to produce an image on such low sensitivity emulsions. Presently when an image is being projected onto a photosensitive plate, a considerable amount of light must be passed through the film over a correspondingly large period of time in order to produce an image on the photosensitive surface.

It would be immediately apparent that if too much light were forced through ordinary lens systems, the lens would rupture. Accordingly, a great deal of time must be sacrificed in order to keep below the limitation of a ruptured lens. However if a long period of time passes in a production of an image on the plate, sharp images will become difficult to attain for transient vibrations and movement of the various parts of the machine will cause the light to shift. about slightly causing an image to be somewhat fuzzy. An increase in the sensitivity would eliminate this problem in that the limitation of a requirement for high amounts of light energy to produce an image would not be required and furthermore a substantial time interval for burning in the image would be drastically reduced to a point where the images could be produced on the fly. In order to achieve these goals the entire environment in which the plate is placed for production of an image must be carefully controlled.

In the present invention the environment is controlled by surrounding the plate in an atmosphere in which the air is heated and the humidity is controlled. Furthermore, the charge is placed on the plate at a preselected polarity such that this is not permitted to effect the sensitivity of the chemicals within the emulsion. And immediately prior to exposure of the plate the light environment surrounding the plate is gradually raised to below what is considered to be the threshold of the chemicals that constitute the particular emulsion. Thereafter when the plate is exposed to the light which constitutes the image desired, a much more feeble light that would be otherwise satisfactory produces a very sharp clear cut image.

Therefore, an object of the present invention is to presensitize photographic emulsions prior to exposure. Another object of the present invention is to reduce the amount of light required to produce an image through a given lens system.

Another object of the present invention is to reduce the time interval required for production of an image of a given exposure.

Another object of the present invention is to increase the speed for producing plates by photographic techniques.

Other objects, features and advantages of the present invention will become apparent from the following specification when read in conjunction with the attached drawing which is an embodiment of the present invention.

Referring to the drawing showing the embodiment of the present invention. A power source 11 supplies a high intensity light source 13 which can be pulsed or be continuous with a shutter. The light is then reflected from the condensing reflector 15 which is then passed through a condensing lens 16 on through a negative in the film plane 17 thence through an enlarging lens system 18. The light then passes through window 27 of a platemaking device 21. (there s an opening in reflector system 22) and thence onto the plate 34.

Up to this point the system appears very much like that which is presently available commercially. However, the emulsion has a certain sensitivity and in order to produce the desired image the light 13 would have to be of a very high intensity but not so high as to rupture the lenses l6 and 18. Moreover, this light would have to remain on for considerable period of time in order to give the emulsion on plates 34 sufficient time to be activated in order to record the impression that the light beam produces thereon.

Therefore in the present invention in order to produce the amount of light needed in the time that this light would be required to be activated a low intensity secondary light source consisting of a reflector system 22 and the light 33. are turned on just prior to exposure to a preselected level which is below the threshold of the chemicals constituting the given emulsion such that they would not be activated by this light alone. However when a small or substantially smaller quantity of light emerges from lens system 18 it would be sufficient to trigger the chemicals into a satisfactory level of reaction to produce a sharp image on plate 34.

When one enters into a scheme where the threshold level of the emulsion is approached very closely just prior to exposure, other sources of energy which might increase the sensitivity of the emulsion must be carefully controlled. Accordingly a voltage 35 is applied to plate 34 and the vacuum table 38 in order to assure that a specific charge of known polarity would be developed across the plate such that the chemicals would not be activated by any stray currents or charges that might appear within the platemaker. ln addition a stream of controlled air temperature and humidity is passed in through inlet 41 and out through outlet 42 in order to control the thermal energy and conductivity of the lens to the emulsion prior to exposure such that the lights 33 are the only source of controlled energy which will raise the sensitivity to just below the threshold such that we will be assured that the chemicals will not be activated by any energy other than that which is produced by the light emerging from the lens 18.

Emulsions used in photography and in platemaking may differ in their chemical constituents, however they all in common are photosensitive. Of course in the case of photographic techniques the films are much faster and much more light sensitive and do not present the same problems that platemaking presents. In platemaking much higher light levels are required and furthermore great periods of time must elapse before an image is burned into the plate satisfactorily for use in printing. However the principles in both cases would remain somewhat the same. Each molecule of the chemical constituents require a certain quantum of energy before the chemical action will take place. And the suppliers of emulsions are very careful to provide an emulsion which has a uniform coating of molecules which require pretty much the same quantum of energy in order to result in a chemical reaction.

in order to prevent inadvertent activation of the sensitized emulsion its sensitivity is kept well below that which is required in the production of images. The reason for this is that the light level in the platemaking machines and in transferring the plates in their original condition when the emulsion was first applied to the plate cannot be controlled such that absolute darkness would be present. Furthermore increasing the temperature of the plate or its exposure to various electri cal charges may induce activation of the chemical in an unwanted manner. So accordingly the sensitivity of all emulsions has been and will always be considerably below that which is required to trigger the chemical reaction resulting in the production of an image on the plate.

in the present schemes of things the sensitivity of the given emulsion is readily determined imperically by controlling the temperature and charge on the plate and the secondary light produced by the low intensity light source. Once the threshold is determined which results in satisfactory plates the environment can be controlled in the approximate vicinity with assurance. Therefore the amount of light produced by light source 13 can be drastically reduced well below the level which would endanger the lens system 16 and 18. Moreover the time period or interval over which the required exposure is needed can be drastically reduced and in most instances by combining it with a proper light level can be reduced such that images on the plate will be produced on the fly. That is an image will be snapped as rapidly as a photograph.

This latter ability becomes extremely important to platemaking for in a platemaking device several exposures will have to be placed on a given plate to provide for a number of pages perhaps contemplated for use in fabricating a book or newspaper. And with the use of step and imposition type platemaker many slides will be able to be inserted and the pulse light source and negatives can be removed to the various quadrants of the plate thereby producing an image on each given section of the plate almost immediately upon exposure resulting in a substantial advantage in the economy of time but also in the clarity of image which has been free of vibration.

The present invention has been described with reference to particular apparatus. it is well understood that many substitutions and variations can be made by those skilled in the art without departing from the true scope and spirit of the present invention. Therefore, the present inventor only wishes to be limited in his invention by the appended claims.

We claim:

1. Emulsion control comprising, image projection means, means for receiving projected images, a photosensitive emulsion distributed uniformly over said receiving means, means for illuminating said receiving means uniformly with predetermined quantity of light prior to exposure of said receiving means, and means for placing a preselected charge on said receiving means.

2. Emulsion control according to claim 1 which further includes means for surrounding said receiving means with air of a preselected temperature and humidity.

3. Emulsion control according to claim 2 wherein said receiving means is a plate for use in printing.

4. Emulsion control according to claim 3 wherein said illuminating means includes a reflector having an opening in its center for permitting the passage of projected images, and a multiplicity of low-level light sources distributed about said reflector to provide uniform light distribution.

5. Emulsion control according to claim 4 wherein said image projection means includes photographic slides containing images of printed matter, means for projecting preselected slide images to preselected quadrants ofsaid receiving means.

Claims (5)

1. Emulsion control comprising, image projection means, means for receiving projected images, a photosensitive emulsion distributed uniformly over said receiving means, means for illuminating said receiving means uniformly with predetermined quantity of light prior to exposure of said receiving means, and means for placing a preselected charge on said receiving means.
2. Emulsion control according to claim 1 which further includes means for surrounding said receiving means with air of a preselected temperature and humidity.
3. Emulsion control according to claim 2 wherein said receiving means is a plate for use in printing.
4. Emulsion control according to claim 3 wherein said illuminating means includes a reflector having an opening in its center for permitting the passage of projected images, and a multiplicity of low-level light sources distributed about said reflector to provide uniform light distribution.
5. Emulsion control according to claim 4 wherein said image projection means includes photographic slides containing images of printed matter, means for projecting preselected slide images to preselected quadrants of said receiving means.
US3620621D 1969-02-12 1969-02-12 Emulsion control Expired - Lifetime US3620621A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US79859669A true 1969-02-12 1969-02-12

Publications (1)

Publication Number Publication Date
US3620621A true US3620621A (en) 1971-11-16

Family

ID=25173806

Family Applications (1)

Application Number Title Priority Date Filing Date
US3620621D Expired - Lifetime US3620621A (en) 1969-02-12 1969-02-12 Emulsion control

Country Status (1)

Country Link
US (1) US3620621A (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3848997A (en) * 1973-06-26 1974-11-19 Durst Ag Auxiliary lighting device for enlargers
US4035078A (en) * 1975-11-05 1977-07-12 Woo Harry W Method and apparatus for increasing contrast and resolution from low density film
US4704348A (en) * 1981-04-24 1987-11-03 Hitachi, Ltd. Exposure of uniform fine pattern on photoresist
US20020181233A1 (en) * 1999-08-05 2002-12-05 Orbotech, Ltd. Illumination for inspecting surfaces of articles
EP1674931A2 (en) 2004-12-16 2006-06-28 Esko-Graphics A/S Beam illumination system and method for producing printing plates

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2331335A (en) * 1940-12-04 1943-10-12 Alvin L Mayer Means for toning photographic prints

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2331335A (en) * 1940-12-04 1943-10-12 Alvin L Mayer Means for toning photographic prints

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3848997A (en) * 1973-06-26 1974-11-19 Durst Ag Auxiliary lighting device for enlargers
US4035078A (en) * 1975-11-05 1977-07-12 Woo Harry W Method and apparatus for increasing contrast and resolution from low density film
US4704348A (en) * 1981-04-24 1987-11-03 Hitachi, Ltd. Exposure of uniform fine pattern on photoresist
US20020181233A1 (en) * 1999-08-05 2002-12-05 Orbotech, Ltd. Illumination for inspecting surfaces of articles
US6832843B2 (en) * 1999-08-05 2004-12-21 Orbotech, Ltd. Illumination for inspecting surfaces of articles
EP1674931A2 (en) 2004-12-16 2006-06-28 Esko-Graphics A/S Beam illumination system and method for producing printing plates
US20080030569A1 (en) * 2004-12-16 2008-02-07 Wolfgang Sievers Beam illumination system and method for producing printing plates
EP1674931B1 (en) * 2004-12-16 2015-07-22 Esko-Graphics Imaging GmbH Beam illumination system and method for producing printing plates

Similar Documents

Publication Publication Date Title
US3615454A (en) Process for imaging and fixing radiation-sensitive compositions by sequential irradiation
US3462221A (en) Method for controlling the quality of photographic image
US3085469A (en) Optical information-processing apparatus and method
US4356255A (en) Photosensitive members and a process for forming patterns using the same
US4000334A (en) Thermal imaging involving imagewise melting to form spaced apart globules
US3923394A (en) Exposure apparatus for use in photographic copiers
GB1244641A (en) Apparatus for exposing and developing photosensitive film
US3972610A (en) Electrophotographic apparatus for production of plural images on a sheet
US1934484A (en) Camera
GB1584779A (en) Laserbeam recording
Harris et al. Copying holograms
GB1424400A (en) Electrical shutter control circuit for a photographic camera
US3940775A (en) Multiple exposure optical recording method and apparatus
JPS57148728A (en) Diffusing plate
JPS5445128A (en) Exposure control system for camera
US3795444A (en) Exposure control apparatus
US3342102A (en) Image plane position appraisal system for a slide projector
GB1230606A (en)
JPS61189636A (en) Exposure method for semiconductor wafer with xenon-mercury vapor discharge lamp
GB1060425A (en) Improvements in or relating to photographic printing machines
US3756718A (en) Color printer
US1801450A (en) Optical printer
US2883556A (en) Light inverters
GB1329064A (en) Apparatus for combining optical images of two or more objects
JPH04225357A (en) Projection type exposure device

Legal Events

Date Code Title Description
AS Assignment

Owner name: LAWYERS CO-OPERATIVE PUBLISHING CO. THE; AQUEDUCT

Free format text: SECURITY INTEREST;ASSIGNOR:RACHWAL INDUSTRIES, INC.;REEL/FRAME:004025/0823

Effective date: 19820813

AS Assignment

Owner name: RACHWAL INDUSTRIES, INC., 280 ELIOT STREET, ASHLAN

Free format text: ASSIGNOR DOES HEREBY RELEASE ITS SECURITY INTEREST IN ASSIGNMENT RECORDED AUG. 19, 1982, AT REEL 4025, FRAME 0823;ASSIGNOR:LAWYERS CO-OPERATIVE PUBLISHING COMPANY, THE;REEL/FRAME:004410/0686

Effective date: 19841115