US2662455A

US2662455A - Means for gravure printing of typographical characters

Info

Publication number: US2662455A
Application number: US255059A
Authority: US
Inventors: Herman R Freund
Original assignee: Intertype Corp
Current assignee: Intertype Corp
Priority date: 1949-06-08
Filing date: 1951-11-06
Publication date: 1953-12-15
Anticipated expiration: 1970-12-15
Also published as: DE838698C; FR1042576A; NL79828C

Description

Dec. 15, 1953 H. R. FREUND MEANS FOR GRAVURE PRINT Original Filed June 8, 1949 4:0 FIG. 4.

INVENTOR HERMAN R". FREUND BY $445,, M441 5% ATTORNEYS H. R. FREUND Dec. 15, 1953 2 Sheets-$heet 2 Original Filed June 8, 1949 FIG. 7.

FIG. 6.

lNV ENTOR HERMAN R. FIPEU/VD BYE n ATTORNEY-5 Patented Dec. 15, 1953 mm ST T S P T T MEANS FOR GRAVURE PRINTING OF TYPOGRAPHICAL CHARACTERS Hermon RJFreund, Brooklyn, N. Y., assignor to p v Intertype Corporation, Brooklyn, N Y., a cotporzttionof New York Original application June 8, 1949, Serial No. 91,882. Divided and this application Novemperfi, 1951, Serial No. 255,059 t V t iClaims. (Cl.95-4.5)

This invention relatesto gravure printing and a portion of a composed page of type matter, in more particularly to typographicalcharacters and the form, of at positive transparency, prepared character bearing"ei'mentsfor iis i'n'the photoin accordance with the invention; 7 graphic m 1 4 Figure 7 is aplanyiewpfe portion of aprintep .f i

practice of the intention; r V H The gra vlire printing process to which the means of the invention are directed is anintaglio the form of a web which islfed reletive s6v the rotating cylinder, The cylinder flooded with inkend the surplus inkis then wiped off the nonfi his no vel efiect is acihg oriotherw setm l c c .7 m te cha ters (the l dthef i w he d pressed-printing areas t o the l ontline;ofueeoh movement of-the cylinderipastthef doctcr, it: is

:nsed; in tg'ravure .4 1 40 Punting 15 idl kfillllnbyithe paper: and ,Figure' '2 'sh'ow'sthe printed impression made dries partiailyhy evaporati on,;due to its extreme dbyconventionai paper. 'The fromthepiin uri e mFi i lim 1 at l y, and Partially adsorption. into .t Figural? illu'stratewelimewhetireducedScale, rthe'fir'st of sexiera l steps inoneoj then ethodsof The ink when applied to the paper spreads preparing the printing surface, according to the slightly from the prec seshape ofthe-individuai preseii'tlinventionf Y 1 c e t F fifiigu're' i illustrates a subsequent step in the screenpettern ofthe ridges in the-printing surprocess within the scope of the inventioni I Heretofore, gravlire printing wsurfaces have "Figure 5 is a plan'vi'ew, zit enlarged stleQof a been customarily prepared fon reproducingtypematrii embodyingth present inyention prematter or text b ,nrsmom osmgithe textin pared; in accordance with the jp ocesses 0f Fiesolid-face type, and tgkinguajproof thereof on ores-Bend 4;' if p at of paper. This proof-Jis them -photo- 6 showeet the scale of Figures 1 and 2, graphed} and arm ive r n a a photograph having opaque letters on a transparent background-is formed from it. This is placed over a carbon tissue-a sheet of gelatin sensitized to light, by means of potassium bichromate for example, so that the normally water-soluble gelatin will be hardened and rendered insoluble by the action of light. The carbon tissueis then exposed to light through the positive transparency so that the gelatin is hardened everywhere except beneath the opaque letters of the transparency. To produce the re-' posed portions of the gelatin. The cylinder then is etched, for example with ferric chloride, through the carbon tissue which serves as a resist and allows etching of the cylinder only where the gelatin has been washed away. The

strokes defining the configuration of the respective typographical characters are thus etched as a network of tiny cells or depressions, with a criss-cross pattern of upstanding ridges separating and isolating the respective cells. This formation is illustrated in Figure 1 wherein the ridges 22 which extend completely across the strokes of the character divide the strokes into the sharp, square-cornered cells 28.

The printed impression made by such an the unhardened areas correspondetched printing surface is shown in Figure 2.

The ink from each of the tiny ink retaining cells has spread on the paper so that the screen pattern is obscured within the outline of the printed character. However, due to the separations between the ink cells 20 along the edges of the etched characters on the cylinder-the breaks produced in the outline of the characters by the ridges 22-the reproduced characters have the serrated or jagged outline indicated in Figure 2, a defect which up to the present has characterized all type matter printed by the gravure process.

There have been various attempts heretofore to remedy the defect described, but none of them has provided a practical solution. For example, it was suggested in Patent No. 843,947 to J. W. lppers that the jagged outlines of large, solidly colored decorative design areas in intaglio printing upon textile material could be eliminated by terminating the ridges of the screen pattern short of the outline of the design to form an ink retaining dam or channel around the boundary of the design area. However, the method proposed to form such channel and the environment in which it was intended for use suggests no practical application in the art of producing readable type matter, which requires a degree of sharpness neither sought nor attainable in the textile art. The later Patent No. 2,456,608 to Harley C. Alger sought to apply the Ippers principle to gravure printing of type matter. This patent however, discloses an unworkable process which depends upon manually engraving the screen pattern in the printing face of metal type members. These were supposed to be used in composing and printing a page of type matter to be photographed and used in etching the printing cylinder as above described. The patent is not clear whether or not the type members were to be of enlarged size. If not, the invention would be altogether impractical because with a metal type member of the same size as the desired ultimate printed reproduction, it would be impossible to engrave in its face, by hand or by any available mechanical means, the extremely fine screen patterns required in gravure work-often involving as many as 22,500 minute, perfectly square and sharp-cornered depressions per square inch of printing surface. Moreover, even if it were possible to make such metal type members, they would be perpetually susceptible to wear and damage to the extremely fine interstices of the engraving, and the extremenly tiny ink cells would easily clog with ink and fine foreign particles from the atmosphere and from printing surfaces contacted by the type members.

If, on the other hand, it Was Algers intention that the metal type members be of a fairly enlarged size, the invention is impractical because of the obviously intolerable awkwardness of handling such type members. There is no available machine by which such large and heavy type could be mechanically composed, so that extremely slow and costly hand composition would be necessary. Even after the Alger patent, accordingly, the art has had no commercially practicable means for producing type characters of sharp outline by the gravure printing process.

The use of the gravure process for the printed reproduction of type matter has accordingly been avoided insofar as possible, although, for the printing of pictorial matter, gravure has many well recognized advantages over other processes. However, because of the manifest ineconomy of printin the type matter of a publication by a different process than that by which the pictorial matter of the same publication is printed, the art has heretofore had either to forego the advantages of gravure for pictorial work, or tolerate the inferior quality of type matter printed by gravure.

The present invention affords for the first time practical methods and means for producing type matter of good quality by gravure. The process of the invention commences with the preparation by drawing (which term is used herein to comprehend drawing, painting and other forms of manual preparation such as composite mock-up) of a master typographical character such as is shown in Figures 3 and 4. One method of preparing such a character is illustrated in Figure 3 and comprises, as a first step, photographically enlarging a conventional gravure screen to provide an opaque negative photographic print 30 of the desired screen pattern. The particular screen pattern illustrated is known as a crossline screen and comprises two sets of equally spaced parallel black lines 32 at right angles to each other on a white background. There are thus formed between the black lines 32 of the screen pattern square, sharp-cornered white spaces 34-.

Any other form of gravure screen may be used, but preferably the screen should be of the same type or pattern as that used in the preparation of the cylinder for printing pictorial and display matter, so that the etching procedures for both the type matter and the display matter may be equalized in timing, acid concentration,

etc. insofar as possible. The screens most frequently used in gravure Work have of the order of 120 to 175 lines per inch, with the width of the lines 32 equal to one-half or one-third the width of the inter-line spaces 34. In the particular screen illustrated the ratio of line width to inter-line space is 1:2.

The screen is enlarged by photographing to such scale as will render manual drawing of the type character most convenient. The actual scale used may be varied according to individual taste and will frequently depend upon the intricacy of the strokes and serifs or" the particular type face, but a lateral enlargement of the order of 40 times has been found satisfactory.

As a second step, the artist blacks out as by inking, a portion of ing in shape and size to the strokes which define the typographical character to be reproduced. Then the artist whites in a marginal area 40 around the outline of the strokes of the character, this area suitably being of a width of the order of that of the black lines 32 of the screen pattern. This leaves visible within such White marginal outline 40 the pattern of black lines 32 and white spaces 34 of the screen. As apparent, the white margin 40 has the appearance of merging with those w ite spaces 34 of the mate reproduction.

According to one method the negative character outline 38 while the screen pattern outline 40.

Alternatively, the artist may prepare the positive character shown in Figure 4 directly Without first preparing the negative shown in Figure 3. In doing so, he may either use an enlarged positive photographic a print having groundand White in black out the character defining area 38. he may draw up the character including the screen pattern entirely by hand.

As a further step the character of Figure 4 is then photographed, this time opaque screen lines 32 but transparent marginal spaces 34'. This transparency, as shown in Figure 5, may be cut to form a circular plaque 42 for mounting in a matrix generally indicated at 44. The matrix 44 will be recognized as of the form described in Patent No. 2,231,899 to H. R. Freund and used in conventional high-speed photocomposing metchines such as that shown in Patent No. 2,391,021 to E. G. Klingenberg et a1. Alternatively, the matrix may be of the type disclosed in Patent 6 No. 1,543,527 to R. J. Smothers wherein both the character and the background are opaque, but 0:" contrasting colors; or, the character images, instead of being on circulating matrices, may be mounted upon a rotatable drum, as in machines of the type disclosed in Patent No. 636,062 to Francis H. Richards. In all such machines, the character images are serially exposed, either intive surface and such surface is afterward developed to form a positive transparency of the composed type matter. A portion of such transparency is shown in Figu "e 6; it has a transparent background and screen lines 32, With letters having opaque marginal outlines 49 and screen spaces This positive transparency is then placed against the carbon tissue and the carbon tissue is exposed to light through the transparency. No separate exposure of the tissue to a linescreen is necessary, since the individual characters formed in accordance with the invention already contain the required screen pattern. Where the same carbon tissue used for preparing the gravure cylinder to print pictorial matter as well as type matter, the portion of the carbon tissue embodying type matter may be masked to prevent exposure thereof While that portion of the tissue embodying the pictorial matter is exposed, as it must be, to the line-screen.

The carbon tissue is next applied against the cylinder and developed and the cylinder then is etched through it. The surface of the cylinder will then appear as shown in Figure 7, wherein each of the characters of the type matter etched on the cylinder has within its outline the depressions 2i) corresponding to the screen spaces 4, and upstanding ridges 22 corresponding to the lines 32 of the screen pattern. Around the entire outline of the character there is a channel or gutter 48 merging with the depressions 2D ridges 22 to tinuous channel 48 after the action of the doctor blade are left filled with ink, which, sreading evenly from such continuous channel 46 around the outline of each character, Will form an impression upon the paper having straight, sharp and even outline defining edges 38, such as shown in Figure 8.

An alternative form of character is illustrated in Figure 9. This is formed according to any of the methods described above, but has a singlene screen instead of a cross-line screenthat is, it has only one set of spaced parallel lines 48, whereby elongated, inter-line spaces 59 are formed across the strokes of the characters and merge with the marginal outline 48 formed around the character according to the invention. The lines 48, as in the previous embodiments, terminate short of the character defining outline 38, so that the embodiment of Figure 9 affords the advantageous results described above. Figure 9 accordingly illustrates one of the alternative forms of gravure screen which may be utilized in the practice of the present invention.

No matter which of the methods described is employed, only one master set of typographical and these may be used again and again in the composition of type matter.

It will be apparent that the invention. provides commercially practicable methods and means for enabling the production of type matter of the required fine quality by the gravure printing processes. However, it should be emphasized that the particular methods and means shown and described are intended as merely illustrative of the invention and in no way restrictive thereof.

I claim:

1. A type character-bearing element for use in the photographic reproduction of type matter by the gravure process, said element bearing, against an opaque background, a typographical character translucent except for an internal pat tern of spaced, opaque lines extending substantially throughout the entirety oi said character but terminating short of the outline thereof to leave a substantially continuous translucent margin extending around said outline.

A type character-"nearing matrix for use in the photographic reproduction of type matter for printing by the gravure process, said matrix having an opening through the body thereof, a plaque mounted in said opening having an opaque background and bearing a typographical character translucent except for an internal pattern of spaced, opaque lines extending substantially throughout actor but terminating short of the outline thereof to leave a substantially continuous translucent margin extending around said outline.

3. In a photographic recording machine or" the type wherein type characters are serially exposed to a photosensitive surface to form a the entirety of said charphotographic record of composed type matter,

the combination therewith or" a type characterbearing element bearing, in an opaque background, a typographical character translucent except for an lines extending tirety of internal pattern of spaced, opaque substantially throughout the ensaid character but terminating short chine of the type wherein type character-bearing matrices are serially and individually exposed to a photosensitive surface to form a photographic record of composed type matter, the

combination therewith ing matrix of duction of a type character-bean the photographic reproby the for use in type matter for printing gravure process, said matrix having an opening through the body thereof, a plaque mounted in said opening having an opaque background and bearing a typographical character translucent except for an internal pattern of spaced, opaque lines extending substantially throughout the entirety of said character of the outline thereof to but terminating short leave a substantially continuous translucent margin extending around said outline.

HERMAN R. FBEUND.

References Cited in the file of this patent Number UNITED STATES PATENTS