Classifications

• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F3/00—Colour separation; Correction of tonal value
  • G03F3/02—Colour separation; Correction of tonal value by retouching
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S430/00—Radiation imagery chemistry: process, composition, or product thereof
  • Y10S430/167—X-ray
  • Y10S430/168—X-ray exposure process

Definitions

• the invention is based on my discovery that the high-light areas of anycopy to be reproduced by the half tone screen process may be surface treated by a fluorescent substance so that by proper illumination or irradiation they will give off an actinic light to close the high-light dots on the photographic plate or film in the camera while the remainder of the copy including high-light areas not treated will be non-luminous or inactive.
• my invention comprises applying to such high-light areas of the copy as are de-. sired to'be pure white or free of dots in the final print or cut, a coating or wash which will leave over such areas a finely divided layer of a fluorescent material of a type adapted to emit a photographically actinic ray upon irradiation, preferably by an invisible or substantially invisible ray such as by ultra violet light, so that after normal exposure of the plate or film in the half tone.
• the irradiation of the copy for fiuorescing the treated high-light areas is preferably done with rays totally invisible or yielding no actinic reflection from any part of an ordinary photoengravers copy such as an artists wash drawing, pen drawing, photograph, or other copy, so that the fluorescent high-lights alone will continue to impress the with the fluorescent material, and with the use of such rays, or even slightly more visible rays, it is an advantage, and in some cases necessary to use a color filter over or behind the lens of a color to stop such reflected rays so that the rest of the photographic plate will not be afiected during the closing-in exposure.
• fluorescent means such materials as will emit an actinic light when irradiated with an invisible radiation or more or less visible radiation, though such materials may also be photo-phosphorescent-that is, capable of giving oil light after irradiation has ceased, and frequently after exposure to ordinary or white light.
• a layer or coating of a chemical or material which is simply photo-phosphorescent be applied to the high-light areas of the copy and be illuminated by daylight or electric or arc light, and the light turned off, the resulting continued phosphorescent glow of the treated areas may alone be sufllcient to close in the high-light dots over such treated areas.
• the subsequent irradiation of the treated copy after the normal exposure will intensify the light emitted from the high-light areas or maintain it at a high state of activity for any desired length of time, but where the treating chemical or material is only fluorescent to invisible radiation it may nevertheless be equally effective to close in the high-light dots, as this depends on the eficiency of the material, the thickness of the coating, and the power Or strength of the irradiating rays. Therefore in my appended claims, unless otherwise qualified the language is intended to cover activating material having any or all of the above explained properties.
• the half tone screen may be moved further from the plate, or swung away or removed entirely from in front of the plate if the construction of the camera permits, to thereby hasten or more completely effect the closing-in exposure.
• fluorescent materials mentioned may be the luminescent or fluorescent grades of sulphides of calcium, strontium, barium, and zinc generally combined with a minute quantity of bismuth or thorium oxide.
• the quality of such materials generally known in trade as fluorescent grade" has been found' to give good results.
• Other substances such as anthracene, eosine, also thioflavine are useful as they are fluorescent under ultraviolet rays of from 3500 to 4500 Ang. without being photo-phosphorescent. Mixtures of the above materials may be used.
• the fluorescent materials are very finely ground up and mixed with an adhesive liquid to form a paste or paint which is applied to the highlights of the picture or copy with a brush, or sprayed on if the areas are large.
• the outlines or edges of the areas may be left sharp or abrupt or they may be blended gradually into the adjacent areas as may be desired.
• a satisfactory vehicle is equal quantities of a 5 or 6% aqueous solution of gelatine and a 20% aqueous solution of gum arabic, to which mixture is added about 50% by weight of the fluorescent material, thoroughly mixed, say anthracene, as it gives a pale yellow tint where applied to the high-lights so that its outline maybe seen and blending effects may be followed.
• the fluorescent light is a greenish white.
• Another good vehicle or binder is a weak aqueous solution of shellac cut with ammonia.
• Another way of applying the powdered fluorescent material is to first paint the desired areas with a slightly tacky solution, or varnish, then dust the material over these areas and brush off all loose particles from adjacent areas.
• a color filter before the lens to absorb any ultraviolet which may be reflected from the copy may be dispensed with by suitable preparation of the whole surface of the artist's board or paper before making the drawing so as to absorb such irradiating rays, and over which the drawing or copy is-made.
• a suitable material for this purpose is the aniline dye known as water soluble Brilliant Green and/ or soluble Brilliant Blue, or mixture of these. A'5% aqueous solution of this together with sufllcient of the gelatine-gum arabic binder to hold it to the paper has been found satisfactory.
• the surface of the paper may be coated by air brush, wet roller, floating, or careful brushing, or the absorbent may be incorporated throughout the substance of the paper of the drawing at the time of manufacture of the paper, or by any other method.
• the absorbent When dry it may be worked over with water color or ink in the ordinary manner, and the fluorescent material may be applied directly over it where desired to have a dotless highlight, but to make the overcoating of fluorescent material more effective the under coat or substratum of ultravioletabsorbent may first be 40 locally washed out,'rubbed off with a sand eraser,
• such a violet ray absorbent may be mixed with the black paint used by the artist in making up his washes, instead of, or together with the absorbent substratum above described.
• the Brilliant Green dye above mentioned or the water soluble dye known as-Saffronine Red may be used, or preferably equal mixtures of both added about 10% to the black water color, such for instance as Windsorand Newton's lamp black water color, and thoroughly incorporated therewith and used in the regular manner for shades and washes in making the drawing.
• an irradiating ray which has no actinic reflecting power on-the surrounding wash drawing or paper uponwhich it is made, such as the X-ray or cathode ray or invisible ultraviolet or infrared ray, no absorbent substratum nor absorbent in the water color wash, nor ray filter over the lens, need be used, as the irradiation on a suitable fluorescent material applied tothe highlights of the picture or copy will cause these areas only. to be luminescent in the closing in exposure.
• the method of producing halt tone screen negatives with closed in dots in the high-light areas for drop-out high-light cuts and prints which comprises-treating the high-light areas only of the photoengravers copy with a fluorescent material adapted to emit an actinic light-on said areas, making the exposure by ordinary light through a photoengravers half-tone-screen, irradiating thei c'op'y, and using the visible light emitted from-@the fluorescent material on the high-lights forclos'ing in the high-light dots on theiscreen negative'by prolonged exposure of said areaa- 1 3.
• the method of producing half tone screen 1 negatives with closed in dots in the high-lightareas for-drop out high-light cuts and prints which comprises-treating the high-light areas only of the photoengravers copy with a fluorescent material adapted to emit an actinic light-on said areas, making the exposure by ordinary light through a photoengravers half-tone-screen, irradiating thei c'op'y, and using
• the method of producing half tone screen negatives withclosed in dots in the high-light areas for drop-out high-light cuts and prints which comprises treating thi hi hlight areas only oi. the photoengravers copy with a fluorescent material adapted to emit an actinic light on said areas when irradiated with a substantially invisible ray, illuminating the copy by substantially white light and making the regular exposure through a photoengrave'rs half-tone screen to form the half tone screen negative, shutting out said white light and irradiating the copy with a substantially invisible ray to cause the treated high-light areas to fluoresce, and using the visible light so emitted for closing in the high-light .dots on the screen negative by prolonged exposure or said areas while filtering from access to the sensitive plate any actinic reflection or said substantially invisible ray from said copy.
• the method of producing halt tone screen 6.
• the fluorescent which comprises treating the high-light areas only of the photoeng'ravers copy with a fluorescent material' adapted to emit an actinic light on material being'liquid soluble and termed into a solution with a liquid and the entire copy treated on its surface with said solution.
• the fluorescent material is photo-phosphorescent and the after glow from the regular illumination of the I copy in making the half tone screen negative is used to close up the high-light dots after the regular source of illumination of the copy has which is also photo-phosphorescent adapted when excited to emit an .actinic ll'xht.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Non-Silver Salt Photosensitive Materials And Non-Silver Salt Photography (AREA)

Priority Applications (2)

Applications Claiming Priority (1)

Publications (1)

Family

ID=23585185

Family Applications (1)

Country Status (2)

Cited By (2)

• 0
  • FR FR963703D patent/FR963703A/fr not_active Expired
• 1941
  • 1941-07-02 US US400826A patent/US2395985A/en not_active Expired - Lifetime

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