USRE6188E - Improvement in photo-mechanical printing - Google Patents

Description

' tographer, have invented Improvements in insoluble, and will receive fatty ink, while the parent or su'ificiently translucent condition to transparent tablet on which it is mounted for UNITED STATES PATENTOFFICE.

Josnrn ALBERT, or vrumcu, BAVABIA.

IMPROVEMENT IN PHOTO-MECHANICAL Pam-rise.

Specification forming part of Letters Patent No.97,336, dated Novc mhcr 30, 18693 reissue No. 4,328, dated April 11, 1871; reissue No. 6.188, dated December 22, 1874; application filed August 15, 1.873. I

To all whom it maiy concerm' Be it known that. I, Josuru ALBERT, of Munich, in the Kingdom of Bavaria, pho

employ a different quality of gelatine for that.

der to accomplish this, my preferred method is to prepare a thinner film than Ipropose to use, and harden it by exposure to the light on one surface, protecting the; other so that it Printiiig Photographs with Fatty Inks, of which the following is a specification z It has been for some time known that chrome gelatine is sensitive to light, and that the parts on which light has acted become capableof uniting with a subsequent coat,

the latter being composed of a different quality of gelatineyand to this ,end I prefer to perform my process in two successive stages, which consist substantially as follows As no material equalsrglass for thecertainty and beauty of the results obtained from it, I take as the base or tablet on' which to. prepare the film a piece of plate-glass, which is cleaned with alcohol, and, by preference, flowed with a mixture of albumen and gelatine, or either separately, and'bichromate of ammonia, and left horizontal to dry. When dry itis laid with its coated side on a dark surface, and exposed for a short time to light transmitted through the glass, until the sur-. face in contact therewith has become insoluble through'the agency of the light, so as to prevent the moistureyto which the plate is afterward subjected, from penetrating to the glass. After this exposure the plate is laid for half an hour in water, and then set aside' to dry. This 'part' of the process can be-performed months in advance of applying the sensitive surface if the film be kept from exposure to light. The process consists in covering the gelatinous coating thus prepared with the final sensitive coat, composed, preferably, of isinglass, one part, gel'atine, two parts, or thereabout, and chromate or bichromate of ammonium, and drying itin the same manner as the first. When dry, the film is ready to receive thepicture, and is placed in the pressure-frame on a negative, and exposed parts not so acted upon, after being moistened, reject the ink.

Various processes have been tried, with more or lesssuccess, in which this property of-ch rome-gelatine is made available by means of light transmitted through a negative, and acting on a fihn of said material, which is washed, inked, and transferred to stone, copper, orv other suitable material, or prepared directly on the surface thereof, and inked and printed from by means of a press.

These processes have been attended with difficulties, among the mostserious of which are want of durability of the film when printed from, and of permanency in its attachment to the surface.,,to which it is affixed for printing, and, also, in not enabling the operator to watch the progress of the action upon the gelatine film of the light transmitted through the negative, and arrest the development of the image atthe proper period of its formation.

It is the object of my invention to obviate these difficulties; and it consists in the mode of preparation-and treatmentof a film of gelatinous, alhuminous, or other equivalent substance, rendered sensitive to light, whereby it is made capable of receiving the photographic image under the negative in a transadmit of the process being observed through said film, and the transparent or partially-' convenient handling and for printing, and to the light in the same manner as is done with whereby a greater-degree of durability is oban albumen print, except that the action of my preferred method of forming the film is to surface whichis-to receive the image. In orwill remain in an unchanged condition, and.

tained. the light isQwatched from the back, andthe The .fihnmay be of any suit-able or desir- -removal effected at thefproper moment to able thickness. for the purpose, and it is apparender the "image perfect. The film is then rent to those skilled in the art, and to those washed in water to remove all unchanged having a knowledge of the properties of chromates, and may then be treated with chrome-gelatine, that it may be composed en chrome-alum, chlorine-water, or any other 00- tire'ly-ofthatmaterial, or its equivalent; but agulati=ngmaterial, in order to render the coat permit the use of other materials, such as glue,

and so hardened on the other as to "be insolu- 2 I missrested at the proper time, substantiallyas set forth. g p

2.. Thedescribedgprocess of producing a more durable. VVhendry it, is printed from in theusual.lithographic manner upon a press adapted to that purpose.

The essential principle of my invention conchrome-gelatine film for printing from with fatty inks, one surface-of which is hardened by the action of light, so as to be rendered insoluble and durable, while the other surface remains sensitive, for the purpose, when exposed to light transmitted through a negative, of receiving the picture, substantially in the manner and-for thepurpose set forth.

,3. A chrome-gelatine'film prepared with a surface produced inthe manner described for printingfrom with fatty inks,-and asupcrhardened under surface afifixed, by the action of light, to a glass tablet or other transparent or translucent medium of sufiicient strengthsists in hardening one surface of the film, so. as to render it insoluble, while yet {its other surface remains sensitive to the action of light, and capable of receiving the impressionofthe picture, or sufliciently adhesive to unite with another layer or film of sensitive material from which to print; and if these conditions be Qbserved both the first and second layers, will gum, dextrine, or almost any adhesive or gelatinous substance, as Well as any, of the salts of chromium, with more or less success. It is apparent from the'foregoing description that the ultimate purpose of my invention is to produce a film, orplate provided with a film, so sensitive on the one surface as to be capable of receiving the photographic image,

as described. 1 p

4,. A glass plate for the printing of photographic, pictures when providedv with afihn having its under surface superhardened by light, substantially as and for the purpose set forth,

v5. Thedescribed process of producing a chrome gelatinefilm for printing from with fatty inks, supcrhardened by light, and preble and durable, substantiallyas set forth.

It is obvious that while glass is thermost ready and facile material for the formation of a film by my improved method, and possesses the greatest transparency, yet other materials which are imperfectly transparent or translupared by photographic agency when 1 treated. cent will answer, the ohject being to retain with chrome-alum,-chlorine-watcr, or other the film during the process of printing and coagulating material for rendering its upper to resist the process of printing, 'substan'tiall secure durability, and the consequent reten or printingsurface more durable, substantially -tion of the film to the surface or tablet to which as set forth. I it is aifixerhit being evidcntthat the.insolu-' 6. The described process of producing a bihty impartedin the first stage of my profilm for printing from With fatty inks, one side photographic agency, when sufiiciently trans= I Witnesses:

cess, by preventing moisture from penetrating of Which is preserved sensitive or adhesive,

through the film, Wlll insure its permanent admaybe des1red,tby laying it upon a dark surhcsion to the substance towhich it is affixed. face While .the opposite surfil-cc is being sub-. Having thus described my inventiomwhatl jected to the hardening process, su bstantiall y claim as new, and desire to secure by Letters asset forth. I

Patent, 'is In Witness whereof I have hereunto signed 1." The described process of producing a my name in the presence of-two subscribing" chromergelatine film for printing'irom with witnesses- I v fatty inks, having one surface superhardened v l ..r 3 1' I by light and its other surface prepared by ALLLRV'I' parent or translucent to permit the action of CARL BRI-TNOR,

light through'ancgatiye to be viewed and ar- A DOLPII LOCHLE.