US2900884A - Photocomposing machine - Google Patents

Description

Aug. 25, 1959 Filed Oct. 25, 1953 E. F. COLEMAN PHOTOCOMPOSING MACHINE 2 Sheets-Sheet 1 INVENTOR. EUGENE R COLEMAN [WM W ATTORNEYS Aug. 25, 9 E. F. COLEMAN 2,900,884

I) PHOTOCOMPOSING MACHINE Filed Oct. 23, 1953 2 Sheets-Sheet 2 INVENTOR. EUGENE E COLEMAN ATTORNEYS United States Patent PHOTOCOMPOSING MACHINE Eugene F. Coleman, Brooklyn, N.Y., assignor to Mergenthaler Linotype Company, a corporation of New York Application October 23, 1953, Serial No. 387,928

3 Claims. (Cl. 954.5)

' This invention relates to photocomposing machines and,

more particularly, to machines in which selected characters are recorded on film in the order in which they are to appear in print.

In many such machines, a plurality of typographical characters, perhaps more or less than an entire font, are arranged in an array, and selected characters of the array are projected, one at a time, at a predetermined master position onto a light sensitive film. In this way, typographical matter can be composed on film, each character being properly spaced and aligned in relation to the other characters in the sequence.

. Character presentation, that is to say, the reproduction of the selected characters at the same master position, is one of the central problems of photocomposition and has been achieved in various ways in the past, such as by relative shifting of the character font and an optical projection system in order to locate the selected character of the font on the optical axis of the optical system, as disclosed in U.S. Patent No. 2,388,961 to Elliott et al., or by providing a stationary font and optical system for each character in the font, as disclosed in the Huebner Patent No. 2,180,417. While these character presentation schemes produce satisfactory results, they also have inherent disadvantages. For example, the schemes which call for relative movement between the projection system and the character font before the composition of each selected character are not only slow but require highly complicated and elaborate machinery and precise locating means to insure that each character selected will be projected at the master position. On the other hand, to provide an optical system individual to each character in the font is not only expensive but requires careful adjustment of each of the numerous lenses. More recent proposals include schemes which require no relative moverhent ofthe character font and-"the character projection means, and which simplify the optical requirements.

The present invention accomplishes its object of reproducing an image of any selected character of a flat array along the same path of projection, in proper focus and without any relative movement between the character array or the optical system, by producing multiple images of the selected character and insuring that one of the images falls along the path of projection common to all of the characters. This general scheme is disclosed in U.S. Patent No. 2,699,101, dated January 11, 1955 wherein the multiple images are created by interference of light waves. The present invention, however, does not employ interference phenomenon, but rather the multiple images are created in a single flat plane by polygonal light reflecting mirrors or polygonal light retracting prisms in combination with appropriate optics.

The details of the invention will more fully appear from the description which follows.

Referring to the drawings:

Fig. 1 is a perspective view illustratin; the components of the present apparatus;

Fig. 2 is an illustrative view of the optical system;

2,900,884 Patented Aug. 25, 1959 Fig. 3 is a face view of the character font plate; and

Fig. 4 is a perspective view illustrating several components of an alternative embodiment.

The apparatus illustrated in the drawings is inclosed in a suitable dark chamber (not shown). Generally speaking, selected characters of a font plate 1 are illu minated on at a time, and images of the selected characters are optically projected at a predetermined position on a light sensitive photographic film 2, the images being photographed thereon one at a time in the order of their selection.

The font plate 1 comprises either a plurality of translucent characters against an opaque background, as shown in Fig. 3, or, alternatively, a plurality of opaque characters against a translucent background. The plate 1 may be made of glass or in the form of a photographic film, and the typographical characters arranged in horizontal rows and vertical columns. The plate 1 is removable to make possible the substitution of typographical characters of difierent fonts.

The characters are projected by field light from a lamp 3, the light rays being directed toward the plate 1 by a condensing lens system 4 to make for relatively even distribution of light over the entire area of the character array.

The characters are individually selected for composition by the operation of a shutter mechanism, represented by the reference character S in Fig. 1, which permits the field light to pass through the selected character. The shutter may be of any suitable design, one such possible arrangement being, for example, the shutter mechanism shown and described in US. Patent No. 2,847,919, dated August 19, 1958, comprising a plurality of horizontal shutter bars, one for each horizontal row of characters, and a plurality of vertical shutter bars, one for each vertical column of characters. The shutter bars are normally closed, but each is adapted to be pivotally operated to open position, so that any character on the font plate 1 can be selected for composition by the operation of one of the horizontal shutters and one of the vertical shutters.

In order to eliminate the effects of color fringe on the reproduced images of the characters, the image producing light rays are directed through a filter 5 of a type which will transmit light that is substantially monochromatic.

The character font plate 1 is located at the focal plane of a collimating lens component 6 which renders the light rays coming from the single exposed character substantially parallel. The parallel light rays then pass through a pair of light transmitting polygonal prisms 8 and 9 constituting one of the most important components of the present invention.

The polygonal prisms 8 and 9 are light transmitting and each face thereof serves to retract the light striking it through a different angle toward an image forming lens 11. The prisms are lano-convex in one cross-section and, assuming that the characters are arranged on the font plate 1 in an equal number of horizontal rows and ver tical columns, the rear flat sides of the prisms are preferably square. The convex sides of the prisms comprise a number of flat parallel faces, the prisms 8 having a horizontal face for each horizontal row of characters on the font plate, and the prisms 9 having a vertical face for each vertical column of characters on the font plate. The prisms 8 and 9 are mounted back to back on opposite sides of a light transmitting member 10, and they are centered with respect to the optical axis P of the optical system. The faces of the prisms are disposed at different angles with respect to the optical axis P, the angular disposition decreasing for faces more remotely located from the optical axis: the center face of each prism (assuming the prism has an odd number of faces) would, of course, be perpendicular to the optical axis.

The light rays coming from the selected character, as projected by the collimating lens 6, are not confined'to a specific prism face but rather cover a Wide area of the prism, preferably striking all of the faces, and, as best shown in Fig. 2, each of the faces of the prisms refracts a bundle of collimated light in a different direction toward the image forming lens 11. The image forming lens 11 in turn produces an image of the selected character for every bundle of light received, so that there is one image for each face of the prisms, the faces of the prism 8 producing a vertical column of imagesand the faces of the prism 9 producing a horizontal row of each of the images in the vertical column. The images formed by the lens 11 will all be formed in the same plane and will be spacially separated. The prisms 8 and 9 may be designed so that one of the images produced of each character on the font plate 1 will fall along thesame path of projection, which path of projection may be coincident with or in fixed relation to the optical axis P. Fig. 2 illustrates multiple images C created from a single selected character C on the font plate 1; Fig. 2, being in two dimensions only, shows only the effect of the prism 8, however, the prism 9, as mentioned above, produces a horizontal row of images of each of the images C It is evident that the light rays may 'be reflected, as well as refracted, toward the optical axis, as shown in Fig. 4, by poly-faced mirrors 8 9 the mirror 8 having an angularly disposed reflecting face for each horizontal row of characters on the font plate 1, and the mirror 9 having an angularly disposed reflecting face for each vertical column of characters on the font plate.

All but the single image to be photographed is masked by the screen 12. The light rays which create the image to be photographed are transmitted through the aperture 12 in the screen.

The optics for producing the image on the light sensitive film 2 are shown and described and the pending application of L. Rossetto et al., Serial No. 354,826, filed May 13, 1953. Briefly, this optical system is composed of an eye piece 13, comprising individual lenses 13 and 13 and an image forming lens system '14, comprising individual lenses 14 and 14 The eye piece 13 is of a well known type, usually identified with the Kepler telescope, and serves to reduce the divergence of the light rays from the lens 11 and to concentrate them in the direction of the lens system 14, which latter producesthe image on the film 2. Different magnification and reduction ratios can be obtained by varying the positions of the lenses 13 and 13 of the eye piece and by varying the power of the lenses. For this reason, the holders for the lenses 13 and 13 are movable in either direction toward or away from the lens 11, and the lenses 13 and 13 are removably mounted in their holders so that lenses of different power can be substituted.

The invention has been shown in preferred form and byway of example only, and many modifications "and variations may be made therein and in its mode of application which will still be comprised within the spirit of the invention. It is to be understood, therefore, that the invention is not to be limited to any specific form or embodiment, except insofar as such limitations are specified in the appended claims.

What is claimed is:

1. In a typographical photocomposing machine, the combination of a stationary font plate presenting an array of type characters arranged thereon in horizontal rows and vertical columns, means forilluminating any selected type character in the array to the exclusion of all the other characters, a collimating lens for rendering the light rays from the selected character substantially parallel, a light bending component arranged to separate and direct bundles of collimated light emanating from the collimating-lens, said light bending component comprising a series of stationary different angularly disposed horizontal light bending elements, all simultaneously 0perative and one for each horizontal row of characters on the font plate, as well as a'series of stationary different angularly disposed vertical light bending elements, all simultaneously operative and one for each vertical column of characters on the font plate, an image forming lens common to all of the characters in the font array and arranged to receive the light rays from the light bending component and form a series of images of t-he'selected character in a common plane, with one image falling ona path of projection which is common to all the characters in the array, a mask located in said plane and containing an aperture positioned in said common path of projection, said mask permitting transmission of the light rays forming the image falling on the common path of projection while preventing transmission of the light rays forming other images, and a light sensitive film onto which the projected images of the different selectedcharacters are recorded, one after another, as they are'successiv'ely formed at the mask aperture.

'2. A combination according to claim 1, wherein the light bending component comprises a polygonal light transmissing and light retracting medium.

3. A combination according to claim 1, wherein the light bending component comprises polygonal light refleeting mirrors.

References Cited in the file of this patent UNITED STATES PATENTS 2,174,003 Ives Sept. 26, 1939 2,203,000 Smith June 4, 1940 2,515,862. Carlton July 18, 1950 2,646,732 Oifeman July 28, 1953 2,699,101 Ferguson Jan. 11, 1955

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