US1456794A

US1456794A - Printing and duplicating

Info

Publication number: US1456794A
Application number: US343662A
Authority: US
Inventors: Gestetner David
Original assignee: NRG Manufacturing Ltd
Current assignee: NRG Manufacturing Ltd
Priority date: 1919-12-09
Filing date: 1919-12-09
Publication date: 1923-05-29
Anticipated expiration: 1940-05-29

Description

Maj 29, 1923. g 1,456,754 I D. GESTETNER PRINTING AND DUiLICATING Filed Deb. 9, 1919 Patented May 29, 1923.

TED ST "res DAVID GESTETNER, OF LONDON, ENGLAND, ASSTG-NOR TO D. GESTETNER, LIMI'JIED, OF

LONDON, ENGLAND.

PRINTING AND DUPLIGA'IING.

Application filed December 9,1919. Serial No. 343,662.

To all whom it may cont-em:

Be it known that I, DAVID GES'I'ETNER, a subject of the King of Great Britain and Ireland, and residin at Neo Cyclostyle Works, Tottenham ale, London, N. 17,

England, have invented certainlnew and useful Improvements in and Relating, to Printing and Duplicating, of which the following IS a specification.

- This invention relates to printing or duplicating with the aid of stencils produced upon Yoshino or like paper or on a suitable textile fabric such as bolting cloth, by the employment of a photographic process of the kind in which the action of light is made use of for changing the solubility of a composition as, for instance, bichromated gelatine in regard to a solvent liquid used as a developer.

Processes of this kind are described in the specification of United States patent to Waters No. 1,327,931, January 13, 1920, and in the specification accompanying my prior United States Patent No. 1,354,478, grant-- ed October 5, 1920.

In the operation of such processes, it is found that where inked surfaces of relative- 1y considerable width or area are formed in the printing operation, there is a pronounced tendency for the ink to spread on the impression receiving surface or for the oily medium of the'ink to spread outwards owing to the capillary attraction of the material of which the impression receiving sur face consists, thus forming a border of oil about the heavily inked portion which naturally detrimentally affects the appearance of the reproduction.

The invention consists broadly in break ing up what would be the solidly inked portion of the reproduction so as to provide portions therein which do not receive ink directly but only as the result of the spreading of the ink passing through the open portions in the stencil coating, and leaving the ground intervening between what would be the solidly inked portions free from ink.

Thus in accordance with the invention the stencil may be formed or be provided with dots, lines or reticulations which will resist" the passage of ink throu h the stencil at what would normally be t e open portions thereof, while the remaining portion of the stencil is entirely impervious to the ink.

These dots, lines or reticulations may, in

accordance with the invention, beformed by treating the layer of composition to be employed in the production of the stencil, as by exposure to light, so as to form thereon dots, linesor reticulations constituted by portions of the compositionwhich have been rendered insoluble.

Thus, for instance, the layer of composition on a suitable support which may be of the character of the carbon tissue employed in the carbon process, is exposed to light under a screen provided with opaque or light resisting dots, lines or reticulations.

A dotted screen adapted for use, in accordance with the invention may be formed b exposing a photographic plate behind a half tone screen and developing and fixing the photographic image thus produced.

The layer of composition on the support after treatment in the manner indicated is ready for use in the production of stencils, by exposure to light under suitable positlves or negatives. and by such further treatment as is described in the patents mentioned, after which treatment the stencils may be used in accordance with the description contained in such patents in the production of prints or impressions.

According to another phase of'the invention the sensitized plate employed in producing the negative of the matter to be reproduced is exposed in order to produce on the plate in succession an image of the matter to be reproduced and an image of a screen formed with lines, dots or reticulations.

The image of the matter to be-reproduced, or of the screen-may be formed first on the plate, after which the image of the screen, or of the matter to be reproduced may be formed thereon, the negative thus produced being. then used in making a positive which in turn is used in making the stencil.

The invention will be described in detail, and by way of example, with reference to the accompanying drawings, in which Figures 1 and 2 are views respectivel in plan and section of a support 1 provlded with a layer of light sensitive composition 2.

after exposure to light according to one mode of carrying the invention into effect, the lines 4 thereon rep-resenting the portions of the light sensitive composition which have been rendered insoluble.

Figures 6 and 7 are similar views of the coated support after it has been exposed to light behind a diapositive of the letter S to be reproduced, the hatched portion 5 representing the insolubilized composition formed as the result of such exposure. On development the white portions intervening between the lines 4 will be washed away and in use, as Will be understood, this stencil will only allow ink to pass through the parts of the sup-port from which the soluble matter has been removed with the result that the representation formed with the aid of the stenoil will be composed of dots arranged to form the letter S. 1

Figure 8, 9, 10 and 11 illustrate another mode of carrying the invention into effect, Figure 8 being a plan view of a sensitized plate, that is to say, a photographic plate of the usual kind which has been exposed in order to produce on the plate an image of the letter S, the hatched portions 6 thereon indicating the light affected portions of the plate and 7 the portions which have not been affected by light.

Figure 9 is a plan view of the plate after it has been again exposed under a lined screen, such exposure causing the formation of dots 8 on the portion of the plate which had not in the previous exposure been acted upon by light. After development in the usual way this plate is arranged over a glass plate coated with an emulsion such as is used in making lantern slides, the whole being then exposed to the action of light in a printing frame or the like with the result that a diapositive, as illustrated in Figure 10 in which 9 represents the surrounding portions of the plate which have not been affected by light, 10 the portion thereof in the form of dots which have also not been affected by light, and 11 the lines intervening between such portions, is obtained. The diapositive thus produced is then employed in making the stencil by arranging the same over a support provided with a coating of bichromated gelatine such as is illustrated in Figures 1 and 2. On exposure a print will be obtained, as indicated in Figure 11, in which 12 represents the portion of the field surrounding the image which will constitute ink impermeable areas, the representation of the matter to be reproduced forming ink permeable foraminous areas of which 13 represents ink resisting elements in the form of. dots and 14: ink permeable spaces in the form of lines between said dots.

The present invention, it may be pointed out, extends not only to the production of stencils in the manner indicated and to the use of such stencils but also consists in a support provided with a layer of light sensitive composition which has been provided with lines, dots or reticulations which will resist the passage of ink throu h the stencil at what would normally be t e open portions thereof, such lines, dots or reticulations being formed, for example, on the light sensitive surface by photographic action.

, While in the above description reference has been made to bichromated elatine as the light sensitive composition, it is to be understood that other light sensitive compositions of the character indicated, as for instance bitumen, may be employed.

In conclusion it may be pointed out that it is of the essence of the invention that the stencilled reproduction shall have pure whites, that is to say shall have, for instance, a ground which receives no ink and is therefore distinguished from the ground which would be produced by means of a half tone negative or positive and an image or impression constituted by an inked surface which is broken up or an inked ground which is broken up and an image or impression thereon in pure white that is to st y an image or impression constituted by a surface which receives no ink.

Having now particularly described and ascertained the nature of my said invention, and in What manner the same is to be performed, I declare that what I claim is l. The process of forming stencils for use in duplicating, which comprises producing by the agency of light a photographic image of the matter to be reproduced and an image of a screen in superposition on a layer of composition which is rendered insoluble in a developer by the action of light and treating the layer of composition with a developer to remove the still soluble portions thereof.

2. The process of forming stencils for use in duplicating which comprises exposing a layer of bichromated gelatine to the action of light to form in succession an image of the matter to be reproduced and an image of a screen in superposition and developing the exposed layer with warm water to remove the portions thereof which have not been affected by light.

3. The process of forming stencils for use in duplicating which comprises exposing a layer of bichromated gelatine coated on a temporary support to the action of light to form an image of the matter to be reproduced and an image of a screen in superposition, developing the exposed layer with warm water to remove the portions thereof which have not been aifected by light and transferring the developed image on to a sheet of porous flexible material;

4. Theprocess of forming stencils for use 1n dupl cating WhlOh comprises. exposing a layer of bichromated gelatine coated on a temporary support to the action of light to form an image of the matter to be reproduced and an image of a screen in superposition, developing the exposed layer with warm water to remove the portions thereof which have not been aifected by light and transferring the developed image on to a sheet of Yoshino paper.

5. A stencil comprising a porous flexible support, an ink resisting material distributed thereover and forming thereon ink impermeable areas and "foraminous areas adapted to permit the passage of ink in using the stencil.

6. A stencil comprising a porops flexible support, a coating ':of a composition rendered insoluble by the action of light adhering by ink areas constituted bya plurality of smaller areas of said composition spaced apart and adapted to permit in using the stencil the passage of ink through the spaces. inter- Venin between the smaller areas.

7. stencil comprising a porous flexible thereto, said layer being constituted support, a light affected bichromated gela tine composition distributed thereover to form foraminous and non-permeable areas equivalent respectively to the normally solidly inked portion ofv the reproduction and the spaces intervening between such por-- tlons.

In testimony whereof I have signed my 7 name to this specification;

DAVID GESTETNER.

impermeable areas and foraminous