US495341A

US495341A - Photogravure-printing plate

Info

Publication number: US495341A
Authority: US
Publication date: 1893-04-11
Anticipated expiration: 1910-04-11

Description

(No pf-Mel.)

F. E. IVLS. PHOTOGRAVURE PRINTING PLATE.

No. 495,341. Mtented Apr. 11, 1893.

Ffdl.

W it I g .liwcniw' will mar Ema-w 112 I by his L/ldornqqs O is g f NITED STATES- FREDERIC E. IVES, OF PHILADELPHIA, PENNSYLVANIA.

PHUTUG RAYU RE IPRIlNTlNG PLATE.

srncmesnon forming part of Letters Patent No. 495.341, dated April 11, 1898. Application ant aw 4, 1891. Serial a. 401,676. (No model.)

1'0 all whom it may concern.-

Be it known that I, Fmrnnnro E. lvns, a citizen of the United States and a resident of Philadelphia, Pennsylvania, have invented a 5 certain Improvement in Photogravure-Printing Plates, of which the following is a specifioation.

The object of my invention is to produce an intaglio photogravure or phototype printl0 ing plate having in the deep shades a surface which will act 'eflectigely to retain the ink during the cleaning of the plate, and this object I attain in the manner hereinafter set forth, reference being bad to the accompanying drawings, in which- .Figu.re 1, is a view of part of an intaglio printing plate made in accordance with my invention showing the plate as it appears after having been inked and cleaned, ready to print; and Fig. 2, is an exaggerated section of the plate.

in ordinary ghotogravure or phototype printing in whic the printing plate is in the term of an intagiic and in which the lights 2 5 and shades of the picture are made up of regularly spaced lines or dots graduated in size according to the shades of the picture, said lines or dots meet or merge in those portions of the plate'representing the blacks or deep shades of the original, hence the surfaces of these portions of the plate are entirely removed by the etching process, and spaces of comparatively large area are formed without any raised lines or dots therein,and in cleanlog the face of the plate, after the inking of the same, and preparatory to printing, the ink is likely to be withdrawn from these spaces owing to the lack of any retaining projections therein, so that, in the deep shades of the pic- 0 ture the printing is frequently of a spotted or irregular character, this being especially the case where the printing is efiected on power presses in which that careful cleaning of the plate resorted to in hand printing is impossia5 hie. Attempts have been made to overcome this objection, by mechanical reugheniug of the sunken portions of the printing plate so "as to provide in these port-ions a surface to hold the ink, but this operation, besides being a tedious and comparatively expensive 5c one, is not properly effective for the purpose.

In carrying out my invention, therefore, I so make the photographic positive from which the usual etched printing plate is to be produced that the lines or dots will extend throughout the deepest shades of the picture, as shown for instance in Fig. 1' of the accompanying drawings,-so that the etched printing plate produced from such a positive will have in the sunken portions representing even the darkest shades of the picture a series of fine lines or projections, as shown for in-' stance at a in Fig. 2, so that they will serve as an efiectual means of retaining the ink in those portions of the plate, and will insure a 6 solid and uniform printing of the deep shades of the picture. These lines or dots may extend to the face of the plate, in which case the light lines or dots will extend throughout the deeply shaded portions of the picture, without, however, assuming such prominence therein as to materially modify the deep tones oi. such parts, or the lines or dots may be slightly reduced in height by the process of chemical etching without materially attesting their function as ink retainers.

A photographic positive of the character described can be prod need in various ways, and hence my invention is not limited to the specific means of making such a positive.

In carrying ut that process in which the body shades of the original are translated into lines or dots by the interposition of a regular pattern of lines or dots in the camera, the exposure may be short enough to leave the lines 8 or dots open to a slight extent in the deepest shades of the picture or in producing a Platte in accordance with my patent of February 8, 1881, No. 237,664, or August 9, 1881, No. 245,501, the pressure imparted to the lined or stippled plate may not be snflicient to completely flatten, or run together, the raised lines or dots in those portions representing the deep shades of the picture.

Having thus described my invention, I claim and desire to secure by Letters Pat enti An intaglio photogravure printing plate in which the light and shade of the picture are In testimony whereof I have signed my made up of regularly spaced lines or dote name to this specification in the presence of graduated in size to accord with the shades two subscribing witnesses.

of the picture, but continued throughout the FREDERZC E. IVES. 5 dee t shades so a.s to serve as ink retainers Witnesses:

in t ose portions of the plate, substantially as WILLIAM D. Comma,

Wififfr... HARRY SMITH.