US2808768A

US2808768A - Photocomposing machine

Info

Publication number: US2808768A
Application number: US369807A
Authority: US
Inventors: Gino F Squassoni
Original assignee: Mergenthaler Linotype GmbH
Current assignee: Mergenthaler Linotype GmbH; Mergenthaler Linotype Co
Priority date: 1953-07-23
Filing date: 1953-07-23
Publication date: 1957-10-08
Anticipated expiration: 1974-10-08
Also published as: GB751063A; CH325123A; FR1103998A; NL189159B; DE937140C

Description

Oct. 8, 1957 G. F. SQUASQNH PHOTOCOMPOSING MACHINE Filed July 23, 1953 mwlwlwullllw G d E SW1/Lamm@ L/GHT United States Patent O PHOTOCOMPOSING MACHINE Gino F. Squassoni, Lynbrook, N. Y., assignor to Mergentha'ler Linotype Company, a corporation of New York Application July 23,1953, Serial No. 369,807 2 Claims. (Cl. 9`54.5)

This invention relates to photocomposing machines and more particularly to machines in which selected typographical characters are recorded on lm 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 atv a time, at a predetermined master position so that they can be photographed on iilm in proper alignment relative to the other characters in the sequence. As eachV character is photographed, the film is advanced to position for the next character to be photographed.

When images of the selected characters are projected optically onto the photographic film, generally speaking, only the character in the array located on the optical axis of the optical system will be properly projected at the master position, the images of the other characters being displaced from said axis by a distance depending upon the remoteness of the character in the array from the optical axis. However, unless all of the characters in the array can be produced at the same master position, irrespective of the position occupied by the character in the array, the proper alignment and spacing of characters in a sequence, necessary for high quality composition, cannot be achieved.

Various solutions of this problem of character presentation have been proposed, as for example by shifting the character array relative to an optical system to locate the desired character on the optical axis (see U. S. Letters Patent No. 2,388,961 to Elliott et al.), or by providing a stationary array and an optical projection system for each character in the array, adjusted to focus the characters at the same position and in the same plane (see the Huebner Patent No. 2,180,417).

In the present invention, character presentation is achieved by a modified form of an electronic tube, or image converter, of the kind generally associated with infra-red telescopes. These tubes have photo-emissive input screens and fluorescent output screens and possess characteristics such that images formed on the input screen by light rays are converted into electron images which are focused on the output screen and there reconverted into ordinary light images. Thus, in the present invention, a whole array of typographical characters is projected by light rays onto the input screen, and then, by dei'lecting the electron image of the character array, a selected character of the array is presented at a master position on the output screen. Means are provided for projecting the image of the character appearing at the master position onto the photographic film. By suitably deflecting the electron image of the character array, any of the characters can be presented at the master position of the output screen for composition on film.

The invention will be described in detail in the specification which follows.

The drawing is a perspective view, partly diagrammatic, of the present apparatus.

Referring to the drawing, a character font plate 1, pre- ICC senting a square array of typographical characters, that is, characters arranged in horizontal rows and vertical columns, is projected on a glass input screen 2a of a cylindrical image converter tube 2 of the type described above. The character array may comprise a plurality of opaque characters on a translucent background, or preferably, and as shown, a plurality of translucent characters on an opaque background. ln'the drawings, light rays from a light source 3 are directed toward the font plate 1 by a condenser lens system 4, this system making for 'augmented and relatively even distribution of light over the entire area of the font plate. The light rays are then directed against the screen 2a toform thereon an image of the whole character font, which image can be produced optically by a lens 5, as shown, or alternatively by positioning the font plate 1 in contact with the outside face of the screen 2a, in which case the lens 5 would not be required.

The interior surface of the screen 2n has a photo-emissive coating, so that the areas of the screen 2a upon which the light rays strike emit electrons, thereby producing an electron image of the entire character font. The electron image is inverted and directed toward and focused upon an output screen 2b at the opposite end of the tube by an electron focusing system, designated generally by the reference numeral 6. The electron focusing system consists of suitable electrodes and apertures which follow design principles well understood in the field of image tube electron microscope design.

The output screen 2b is opaque, except for a small fluorescent material coated area 2c, preferably located centrally on the screen and on the principal axis P of the path of projection, so that, if the central character of the array 1` is on the axis P, it will be the character normally produced on the fluorescent area or aperture 2c. It is evident, however, that by deliecting the electron image Various amounts in horizontal and vertical directions, any selected one of the other characters of the square array can be produced on the area 2c, the said area serving as a common character-presentation point for all of the characters. The selected character thus produced is focused on a light sensitive photographic iilm 7 by a lens 8. In this way, characters may be photographed on the lm in the order in which they are produced on the fluorescent screen 2C, the tilm being moved progressively between each exposure a distance determined by the set width of the characters, and the film thereafter used in a well known manner to produce a printing plate for printing the composed typographical matter.

The shifting of the electron image by different set distances in horizontal and vertical directions, to make possible the selection of any desired character, is accomplished by horizontal and vertical electrostatic deflecting plates H and V, respectively. The dellections may also be produced by magnetic coils placed near the tube. Since the electron paths are deflected from what would otherwise be their path of travel by angles proportional to the applied electrostatic potential, it is eviden-t that by impressing appropriate voltages on the deflection plates any selected character of the font can be produced on the fluorescent screen 2C. The deflecting voltages impressed upon the horizontal and vertical deecting plates may be controlled from a keyboard in the manner fully shown and described in U. S. Patent No. 2,624,798 of E. W. Dinga.

The electrodes of the focusing system 6 are normally adapted to be connected to the ground side of a voltage source B, as is the input screen 2a, so that normally the tube 2 will not conduct. This condition is illustrated in the drawings by showing the electrodes connected to contact arms 10, these arms being in the position indicated by the broken lines. When the keyboard is operated, however, the contact arms 10 are adapted to be shifted,

by any suitable operating means 11, into contact with positive terminals of the battery B, whereby the tube will conduct for a predetermined time duration adequate for the exposure of the selected character. When the exposure of the selected character has been made, the contact arm-s are again shifted to the ground side of the voltage source B to cut oi the ow of electrons to the output screen.

The invention has been shown and described in but a single preferred form and lby way of example only, and, obviously, many modications and variations may be made therein and in its mode of application which will still he comprised within the spirit of the invention. It is to be understood, therefore, that the invention is not to he limited to any specified form or embodiment, or in any other respect, except insofar as such limitations are specified in the claims,

i claim:

1. in a photocomposing machine, the combination of an array of typographical characters arranged into two crossing sets of rows, the rows of the two sets being spaced in directions transverse to each other, a single electron tube having an input screen at one end and an output lscreen at the other end, the inside surface of the input screen having a photo-emissive coating and the inside surface of the output screen having a fluorescent area for receiving the image of a single selected character, said area serving as a common character presentation point for all of the singly selected characters, means for forming an image of the whole character array on the input screen by light rays, to cause the photo-emissive coating of the input screen to emitan electron image beam of the entire array and for directing the electron image beam in said tube in inverted form towards said output screen, means for deflecting the electron image beam while in said tube in two directions transverse to each other, to bring any selected part of the beam representing a selected character within the predetermined output screen area constituting the common presentation point for all the singly selected characters in the array, and to form an image of the selected character on said output screen area, and an optical system for projecting the image of the selected character from said output screen area onto a light sensitive member.

2. in a photocomposing machine, the combination of an array of typographical characters arranged into two crossing sets of rows, the rows of the two sets being spaced in directions transverse to each other, a single electron tube having an input screen at one end and an output screen at the other end, the inside surface of the input screen having a photo-emissive coating and the inside surface of the output screen having a iluorescent area for receiving the image of a single selected character, said area serving as a common character presentation point for all of the singly selected characters, means for forming an image of the whole character array on the input screen by light rays, to cause the photo-ernissive coating of the input screen to emit an electron image beam of the entire array and for directing the electron image beam in said tube towards said output screen, means for deecting the electron image beam while in said tube in two directions transverse to each other, to bring any selected part of the beam representing a sclected character within the predetermined output screen area constituting the common presentation point for all the singly selected characters in the array, and to form an image of the selected character on said output screen area, and means for photographing the image of the selected character projected on said output screen area.

References Cited in the tile of this patent UNTED STATES PATENTS 2,131,185 Knoll Sept. 27, 1938 2,138,853 Coolidge May 16, 1939 2,283,383 McNaney May 19, 1942 2,420,197 Rosenthal May 6, 1947 2,603,418 Ferguson July 15, 1952 2,624,798 Dinga Jan. 6, 1953 FOREIGN PATENTS 988,724 France May 30, 1951