US2431710A

US2431710A - Gravure plate

Info

Publication number: US2431710A
Application number: US495700A
Authority: US
Inventors: Oswald R Schultz; Robert F Nestle; Matthew J Romano
Original assignee: PHILADELPHIA INQUIRER CO
Current assignee: PHILADELPHIA INQUIRER CO
Priority date: 1943-07-22
Filing date: 1943-07-22
Publication date: 1947-12-02
Anticipated expiration: 1964-12-02

Description

Dec. 2, 1947.

O. R SCHULTZ ETAL GRAVURE PLATEX Filed July 22, 1943 A? A; k, INVENTORS v fizz/25:21:2

Patented GRAvUnE PLATE Oswald R. Schultz, New York, N. Y., and Robert F. Nestle, Ardmore, and Matthew J. Romano, Philadelphia, Pa., assignors to The Philadeb phia Inquirer 00.,Philadelphia, Pa., a corporation of Delaware Application July 22, 1943, Serial No. 495,700

production of the light tones or tints is improved.

With this and other objects which will appear in the following full description in mind, the invention consists in the novel printing surface which will now first be described in connection with the accompanying drawing and then more particularly pointed out in the appended claims.

In the drawing:

Figure 1 is a representation of a picture to be printed and takes the form of a conventional representation' of a cylinder with the various shadows and lighted and shaded areas indicating the different tones to be produced;

Figure 2 is a schematic plan view showing the cell structure in a portion of the printing surface which is intended to produce a dark tone;

Figure 3 is a cross section taken on the line-33 of Figure 2;

Figures 4 and 5 are views similar to Figures 2 and 3 respectively, but showing a .cell structure appropriate for printing a middle tone; and

Figures 6 and 7 are views similar to Figures 2 and 3 respectively. but showing a. cell structure suitable for printing a light tone.

A printing surface according to the invention 'will normally be prepared by photogravure, util- (Cl. ml-401.1)

' by the reference numerals 2, l and6. corresponding respectively to Figures 2. 4 and 6 of the drawing. 1

As will be understood by those skilled in the art, the screen pattern employed will consist of a large number of small elements, a pattern consisting of 150 lines to the inch being normal. Figures2 to '7 accordingly represent views of portions of the printing surface magnified approximately one hundred times.

As appears from Figures 2 and 3, the printing surface in the deep tones is composed of square, or approximately square, ink retaining cells I 0 which are separatedby walls I l forming the bearing surface? for the doctor blade and serving to separate the cells it] from each other and to form number of ink cells which are etched into the plate or cylinder to be used in printing and which are separated by unetched walls so as tg/form ink retaining pockets and to provide a bearing suitable ink retaining pockets. The depth of the cells I!) will normally be only a few thousandths of an inch. The width of the walls may be, as indicated, much less than the width of the cells,

a ratio of approximately 1 to 5 being practical, so

that approximately seventy per cent of the entire printing surface is occupied by the ink carrying cells where the darkest tones are to be reproduced.

In the middle tone, as illustrated in Figure 4, the cells I: will be smaller and the cell walls I:

will be wider so that the ink carrying area of the printing surface is reduced. The cells I: are, in addition, shallower than the cells In so that the quantity of ink deposited upon the paper, orothenmaterial being printed, is further reduced by comparison with that deposited upon it in the deep tones.

As shown in Figures 6 and '7. still lighter tones are reproduced by portions of. the printing surface in which the ink carrying cells M are still further reduced in area and in depth while the cell walls I5 are correspondingly broadened.

In all tones, from the deepest to the lightest, the centers of the ink cells are correspondingly spaced and positioned, the difference in the printing surface being obtained by varying the area and depth of the cells rather than the number of cells included in a given area of the printing surface.

As is apparent'from the drawing, the printing widths of the cell walls and the cells, as well as the depth of the latter, are varied. This feature of .the use of the characteristic gravure pattern is essential in the dark tones, as the ink carrying,

cells must be placed with their sides parallel rather than in half-tone formation or diagonal ing surface having a half-tone pattern in the deep tones cannot be used satisfactorily for monotone printing or for two-color printing. The characteristic gravure pattern is not, however, essential in the lighter tones since the reduced requirements as to ink carrying capacity in these tones permits the orientation of the ink carrying cells in any desired manner. In fact, it is practical to have the ink carrying cells of a diflerent shape, as for example circular, from that of the ink carrying cells in the deep tones.

While only three depths of tones have been specifically illustrated, it will be understood that a printing surface according to the invention will normally contain a continuous gradation of separated by walls providing a doctor blade bearing surface between the said cells.

2. An intaglio printing surface having ink car- I rying cells varying efiectively in both area and tones from the very deepest to the highlights and in areas of varying tone will consist of ink cells of progressively or gradually varying diameter and depth.

Theimproved printing surface of the invention may be employed either for monotone or multicolor printing and in the latter case a number of sets of printing surfaces will be employed in the conventional and well understood manner. As will be apparent from the foregoing description, the printing surface of the present invention extends the range of tones which can be printed very largely by comparison with known intaglio printing surfaces. By comparison with conventional photogravure, equal depth is achieved in deep tones while the range of reproduction in the light tones is largely extended. On the other hand, by comparison with any of the various re- 3 verse half-tone surfaces, equal reproduction. is obtained in the light tones while the range 01' reproduction in the dark tones is very greatly extended.

What is claimed is:

1. An intaglio printing surface having ink carrying cells varying efiectively in both area and depth according to the depth of tone to be printed and the cells of greatest area being arranged in depth according to the depth of tone to be printed and the cells of greatest area being square and arranged in a cross-line gravure screen pattern, all the said cells being separated by Walls providing a doctor blade bearing surface between the said cells.

3. An intaglio printing surface having ink carrying cells arranged in a gravure screen pattern and varying effectively in both area and depth according to the depth of tone to be printed, all the said cells being separated by walls providing a lilisoctor blade bearing surface between the said ce 4. An intaglio printing surface having square ink carrying cells arranged in a cross-line gravure screen pattern and varying effectively in both area and depth according to the depth of tone to be printed, all the said cells being separated by walls providing a doctor blade bearing surface between the said cells.

The following references are of record in the file of this patent:

UNITED STATES PATENTS 5 Number Name Date 2,182,559 Henderson Dec. 5, 1939 2,039,195 Sterling Apr, 28, 1936 2,040,247 Dultgen May 12, 1936 2,660,640 Shaw Nov. 10, 1936 OTHER REFERENCES Commercial Engraving and Printing, 1921, Hacklemar, published by Commercial Engraving Publishing Company, Indianapolis, Indiana, U. S.

a gravure screen pattern, all the said cells being 45 A"page