US3814848A - Photographic type face reproducers - Google Patents

Photographic type face reproducers Download PDF

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Publication number
US3814848A
US3814848A US00310683A US31068372A US3814848A US 3814848 A US3814848 A US 3814848A US 00310683 A US00310683 A US 00310683A US 31068372 A US31068372 A US 31068372A US 3814848 A US3814848 A US 3814848A
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character
scanning
portions
drum
characters
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D Kyte
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41B—MACHINES OR ACCESSORIES FOR MAKING, SETTING, OR DISTRIBUTING TYPE; TYPE; PHOTOGRAPHIC OR PHOTOELECTRIC COMPOSING DEVICES
    • B41B19/00—Photoelectronic composing machines
    • B41B19/01—Photoelectronic composing machines having electron-beam tubes producing an image of at least one character which is photographed
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41B—MACHINES OR ACCESSORIES FOR MAKING, SETTING, OR DISTRIBUTING TYPE; TYPE; PHOTOGRAPHIC OR PHOTOELECTRIC COMPOSING DEVICES
    • B41B19/00—Photoelectronic composing machines
    • B41B19/01—Photoelectronic composing machines having electron-beam tubes producing an image of at least one character which is photographed
    • B41B19/16—Character carriers associated with electron-beam tubes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41B—MACHINES OR ACCESSORIES FOR MAKING, SETTING, OR DISTRIBUTING TYPE; TYPE; PHOTOGRAPHIC OR PHOTOELECTRIC COMPOSING DEVICES
    • B41B27/00—Control, indicating, or safety devices or systems for composing machines of various kinds or types
    • B41B27/28—Control, indicating, or safety devices for individual operations or machine elements

Definitions

  • ABSTRACT The signals required to control reproduction of characters on the print-out cathode ray tube in a phototypesetting machine consist of a series of binary codes indicating successive line positions in a raster at which the beam is to be switched on and off in re-forming a character on the print-out tube.
  • a ring of transparent characters on a rotary opaque carrier are selectively illuminated from one side of the ring for flooding each required character in turn as the carrier rotates and a line of miniature photo-diode devices is arranged on the other side of the ring in scanning position relative to the illuminating means to detect and signal the physical two-dimensional position on a raster basis in a character area of each ON and OFF change in illumination on the diodes.
  • Detector means successively scan the photo-diodes at high speed relative to the rotational speed of the character carrier and detect the ON and OFF changes in their electrical condition the coordinate positions of which in a character area are signalled to code-responsive means.
  • FIG 3 PATENTEDJUN 419M 1814-848 sum 3 or 3 SECTION THROUGH ROTA'TING DRUM Cl L5! 3 L2 L52 LP LS4 L4 BACKGROUND OF THE INVENTION
  • C.R.T. the electron beam produces a scanning-character images in matrix form on a photographic master. lines. During the scanning of each line, the beam current is switched OFF and ON so that only those parts of the line outside the confines of the character image give visible light from the phosphor screen.
  • the signals required to control the character reproduction on the print-out C.R.T. can be produced by utilising a flying spot scanner C.R.T. SCANNING CHAR- ACTER IMAGES IN MATRIX FORM ON'A PHOTO-v GRAPHIC MASTER.
  • the scanner is operated in synchronism with the print-out C.R.T. so that the brightness of the light spot of the latter is controlled by the video signal obter basis in a character area of each ON and OFF change in the secondary illumination.
  • a ring of transparent characters on .a rotary opaque carrier are selectively illuminated from one side of the ring for flood lighting each required character in turn as the carrier rotates, and a line of miniature photodiode devices arranged on the other side of the ring and in scanning position relative to the illuminating means.
  • Detector means successively scan the photodiode devices at high speed relative to the rotational speed of tained from the simultaneous scanning of a selected character on the master matrix.
  • each character shape is coded into a series of binary codes indicating successive line positions at which the beam is switched ON or OFF.
  • codes are. permanently stored in a computer store, so that the group of codes for any desired character can be extracted for use in reforming the character on a print-out tube.
  • This invention relates to type-face reproducers suiting binary-coded information representative of the.
  • shape of characters and consists essentially of equipment-for generating coded electrical information defining the shape of visual characters comprising means for illuminating through the air a character on a photo- 1 differential background and thereby creating secondary airborne illumination embodying the character shape, and photo-responsive means physically arranged for illumination in air by said secondary airborne illumination and electrically arranged for detecting and sig nalling the physical two-dimensional position on a rasthe character carrier and detect the ON and OFF changes in their electrical condition, the coordinate positions of which in a character area are signalled to code responsive means.
  • FIG. 4 is a schematic representation of the scanning arrangements for a coordinate array of characters on the-rotary matrix.
  • a light source e.g., a tungsten lamp
  • LS illuminates a diaphragm D'via a lens L1.
  • the diaphragm D has a circular or rectangular hole whichis focussed by means of a lens L2 and a plane mirror M on to the surface of the film strip 5.
  • the optical constants and the size of the hole in the diaphragm are arranged such that the patch of light on the film strip is at least as large as the largest character.
  • a simple light source flooding a rectangular section light beam generator can be provided adjacent the film strip.
  • the photo-diode array is shown diagrammatically in FIG. 2. It consists of a series of small photo-diodes placed close together in a straight line. Such arrays are manufactured out of one or two semiconductor slices and are available from several manufacturers of integrated circuits.
  • the arrays have typically 256 separate diodes and have a built-in sequential sampler (or dynamic shift counter) SS, FIG. 3, which permits the signal from each of the photo-diodesto be sampled sequentially on application of suitable control signals.
  • SS sequential sampler
  • Such a device is the State Line Scanner made by the Reticon Corporation, 365 Middle'field Road, Mountain View, California, USA, and marketed in Europe, for instance by Walmore Electronics Limited, 11 l5, Betterton Street, Drury Lane, Lon don, WCZH 988, in which the drive circuit for the shift counter is fed from a simple pulse train such as that from the oscillator OS, FIG. 3.
  • FIG. 1 Although not essential for the operation of the invention, two further features are shown on FIG. 1 which make the system easier to produce and operate.-
  • the lower part of the line protrudes beneath the lowest point of any character. This part is also illuminated, either by the main light souce LS or by a subsidiary system. An image is formed external to the drum by a lens (not shown). In the same vertical line as the linear photodiode array, but lower down, is placed a single photodiode SC. The purpose of this diode is to detect the start of a character by giving a pulse as the image of-the thin start character line passes across it.
  • the start character diode SC senses these two lines and gives a double pulse which is used by the control circuits explained later.
  • a film strip' containing a series of closely spaced parallel lines G. These lines are also illuminated by a light source (not shown) and are sensed by the photodiode DF. This diode, therefore, emits a series of electrical pulses the frequency of which is proportional to the speed of the drum.
  • the lines G may cooperate with a set of micrometer lines on a superposed static film strip to form by the well-known Moire Fringe technique, a pulse train of a higher order of frequency on diode DF.
  • the prime purpose of this system is to ensure that the control circuits operate in synchronism with the drum speed. They are not essential when the drum speed is closely controlled by other means.
  • control circuitry is shown in block diagram form in FIG. 3.
  • the blockCCT is the character counter and consists of a simple binary counter with a capacity at least equal to the number of characters around the drum. If this is 127, the counter CCT will have 7 stages. I
  • the block marked DPD is a double pulse detector.
  • the photo-diode SC gives two pulses close together when the image of the double line DS passes across it.
  • the circuit DPD detects this occurrance and resets the counter CCT to zero. Thereafter, each time that the diode SC sees one of the start character lines, the counter CCT is advanced by one. Thus this counter keeps track of which character is passing through the illuminated area of the drum surface.
  • each binary stage of the counter CCT (typically eight in all) are fed to a coincidence detector CD. Also feeding CD are the equivalent binary stage outputs from a code request store CRS which has been supplied with a binary code CR representing the character required to be scanned and digitised. This code may well be supplied by a computer controlling the whole system.
  • the coincidence counter When the code requested is equal to the code in the character counter CCT, the coincidence counter will give an output pulse on line SSP.
  • This pulse performs three functions. First, it resets via RES], the linear photo-diode array shift counter SS which controls the sequential activities of the vertical photo-diode array PDA in the plane P, FIG. 1.
  • pulse SSP resets via RES2, a binary counter PDC whose purpose is explained below.
  • pulse SSP sets the scan flip-flop SF Fl which starts the whole process of scanning and digitising of the particular character selected.
  • the photodiode DF is giving out a continuous stream of pulses proportional to the speed of rotation of the drum. These pulses appear on line DF in FIG. 3 and are fed to a frequency divider FD.
  • the output of this circuit is also a continuous stream of pulses synchronised to, but not necessarily at the same frequency as those from the photo-diode DF.
  • pulses are differentiated to produce a series of narrow spikes.
  • the AND gate AG] When the AND gate AG] is primed by the setting of the scan flip-flop SFFl, the next spike from divider FD will pass through AG] and set the second start flip-flop SFFZ.
  • This flip-flop now primes AND gate AGZ so that high-frequency pulses from an oscillator OS are allowed to control the shift counter SS connected to the photo-diode array PDA.
  • the frequency of the oscillator OS must be at least as high as theproduct of the frequency of the spikes from divider FD and the number of photodiodes in the array PDA so that the array is completely scanned once between each adjacent pair of spikes, In practice, the frequency should be somewhat higher than this product to give a reasonable safety margin to this system.
  • each pulse that enters the counter SS causes the system to sample the next photo-diode in the array.
  • the corresponding photo-diode signal appears on the output line VO from SS.
  • the pulses cause counter SS to sample successive diode signals, they also increment a binary counter PDC.
  • counter PDC contains the number of the diode in the array which is being sampled at any time.
  • the output signal V0 is passed throughthreshold and limiting circuits TLC so that it is either an on or off signal. It then passes to the input of a flip-flop VFF which changes its state whenever the V0 signal makes a transition from high to low or vice versa, that is, when the sampling shift register passes from an illuminated diode to a dark diode or vice versa.
  • a short pulse will be generated by either of the two one-shot circuits O81, 052.
  • This pulse after passing through the OR gate 0R1 primes a set of AND gates AGS which image the components of the pDC counter so that the state of the counter (i.e., the number of the photodiode at which the transition occurs) is passed as a binary code to a Digital Memory DM.
  • This code can also be used to signal to a lines per character counter LPC described below successive line scans through a character.
  • the output from theAND gate AC3 drops to zero and signals via one-shot circuit 054 to reset the flip-flop SFF2 so that no more pulses are fed to the photo-diode shift counter SS until the next spike from divider FD is received.
  • the scans of the diodearray are synchronised with the pulses from F3 and hence to the speed of the drum. This ensures that the scans are made ata prescribed number per inch of drum movement (typically 650 per inch) irrespective of the actual drum speed.
  • Becuase characters for quality typographic reproduction vary in'width, the number of linear scans which must be made varies from character to character. For example, over three times as many scans are necessary to cover an M as for an i.
  • the number of linear scans to completea character must, therefore, be controlled according to the character being scanned.
  • This information is usually available in a photo-setting system in a binary coded form, especially if the system is computer-controlled.
  • a computer or other device calls for a character by sending a binary code to the "code request store CR5 and, at the same time, sending a number representing the width of the character to the Lines per Character counter (LPC).
  • LPC Lines per Character counter
  • the nature of the Digital Memory DM depends on the use to which the system is being put.
  • the store DM could conveniently take the form of a static shift register capable of storing the maximum number of codes needed to describe a whole character. For characters up to 36 pts. in size, (i.e., about one-half inch), a static shift register to hold 1,024 codes would be satisfactory. Such devices are available cheaply on integrated circuit chips.
  • a system of the above type would, however, be comparatively slow because it would be necessary to wait, on an average, for half a drum revolution for every character. At a typical drum speed of about 13 revolutions per second, this would give an output speed of about 26 characters/second.
  • the store would conveniently take the form of a short shift register (holding only a few codes) followed by a random access memory in known manner. The latter could well form part of the core store of a computer.
  • the computer would analyse the next, say, five characters to be printed, arrange them in the order that they appear on the drum as already known, and'send code requests in that order to the digitiser.
  • five digitised characters would be in the memory.
  • the next five characters are called for and so on.
  • Speed can also be increased by using more than one linear diode array, in conjunction with additional means for illuminating other positions on the drum. For example, two such arrays arranged at opposite points of the rotating drum would double the access speed without increasing the size of the temporary digital memory.
  • the scanning device can have more than one character set.
  • Several such sets could be arranged one above the other and accessed in known manner either by (a) moving the rotating drum vertically into different positions, or (b) by moving the source of illumination and the linear diode array.
  • several lenslets one for each character set could be used as shown diagrammatically in FlG. 4.
  • the lenslets L, to L focus the corresponding illuminated characters C l to C4 ontoa single area in which is placed a single linear diode array LP.
  • To select one of the four character sets only one of the 4 light sources LS1 to LS4 is switched on. Alternatively, all light sources are allowed to remain on and the light beams not required could be shuttered off with electro-magnetically operated shutters.
  • this can be achieved in the scanning system described by altering the rate at which the linear photo-diode array is scanned relative to the drum speed.
  • This is the purpose of the frequency divider block FD in FIG. 3.
  • the scans per inch of-drum movement can be varied.
  • the divi-' sion factor was one for characters to be reproduced at 30 pts., it would be two for characters at 15 pts., etc.
  • the speed of rotation of the drum and i the number of scan lines per character will be such that the limiting frequency of the linear photo-diode system will be reached. At this point, it is not possible to increase the scanning resolution without decreasing the drum speed. Since this would affect access time, the preferred method of operation would be to optimise drum speed to give minimum access time and satisfactory definition for characters in the range of sizes from 5 l2 pts. and then to slow the drum to half-speed for characters in the range 12 24 pts.
  • linear photo-diode array is a convenient and cheap way of implementing the system described, it is also possible to achieve similar results by 65 a series of coincident lines, and an image of the scan line position on the screen focussed onto the rotating drum.
  • the emergent light from the scanning of a char acter on the drum would be picked up by a lens system and passed to a photomultiplier tube, the output of which would be passed to line VO, FIG. 4.
  • a character carrier member a scanning member, means connected to one of said members to move it repeatedly along a given path with respect to the other member so that there is cyclical relative motion between the members along said path with the motion being at a given rate
  • said character carrier member having means to visually display each of said characters against a photo-differential background in a sequential series parallel to said path so that with said relative motion there is first an approach to a character, then a stage of movement adjacent that character and then a separation from the next character in turn and the scanning member, with said stage of movement adjacent the character taking place in a given period of time
  • said carrier member having indexing means indicative of which character is in said stage
  • said scanning member including means for scanning transversely of said path at a rate such that a plurality of sweeps across each character takes place during said stage whereby during each sweep an electrical signal is produced which signal represents a portion of the character and at the time of the subsequent sweep there has been relative motion between the character and the scanning member so that said subsequent sweep traverses, and produces electrical signals indicative of
  • said carrier member comprises a rotatable drum having an inside and an outside and having portions which are at least partially transparent and portions which are non-transparent, which portions define said characters and also define lines at each side of each character which lines form part of said means for identifying which character is in said stage, and means at one of said sides of the drum for shining light through the at least partially transparent portions to produce said visual display, and
  • said scanning member is stationary on the other of said sides of the drum in a position at which the light from said at least partially transparent portions falls on said scanning means.
  • said means for scanning transversely comprises a plurality of photodiodes positioned sequentially in a line generally normal to said path with the end diodes in the sequence being spaced apart sufficient to extend across the corresponding dimension of said visual display.
  • said carrier member comprises a rotatable drum having an inside and an outside and having portions which are at least partially transparent and portions which are non-transparent, which portions define said characters and also define lines at each side of each character which lines form part of said means for identifying which character is in said stage, and means at one of said sides of the drum for shining light through the at least partially transparent portions to produce said visual display, and
  • said scanning member is stationary on the other of said sides of the drum in a position at which the light from said at least partially transparent portions falls on said scanning means.
  • indexing means includes a visual mark transverse to said path and positioned between each character and further visual marking means to identify each time that the cycle of relative movement repeats.
  • said means for scanning transversely comprises a plurality of photodiodes positioned sequentially in a line generally normal to said path with the end diodes in the se- 7.
  • said carrier member comprises a rotatable drum having an inside and an outside and having portions which are at least partially transparent and portions which are nontransparent, which portions define said characters and also define lines at each side of each character which lines form part of said means for identifying which character is in said stage, and means at one of said sides of the drum for shining light through the at least partially transparent portions to produce said visual display, and
  • said scanning member is stationary on the other of said sides of the drum in a position at which the light from said at least partially transparent portions falls on said scanning means.

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  • Character Input (AREA)
  • Facsimile Scanning Arrangements (AREA)
  • Preparing Plates And Mask In Photomechanical Process (AREA)
  • Character Discrimination (AREA)
US00310683A 1971-12-09 1972-11-30 Photographic type face reproducers Expired - Lifetime US3814848A (en)

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GB5742171A GB1381102A (en) 1971-12-09 1971-12-09 Photographic type face reproducers

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US00310683A Expired - Lifetime US3814848A (en) 1971-12-09 1972-11-30 Photographic type face reproducers

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US (1) US3814848A (enExample)
JP (1) JPS4866756A (enExample)
FR (1) FR2159120A5 (enExample)
GB (1) GB1381102A (enExample)
IT (1) IT982454B (enExample)
NL (1) NL7216475A (enExample)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4496946A (en) * 1982-09-28 1985-01-29 Peratron Corporation Programmable electronic display
US4658301A (en) * 1983-06-03 1987-04-14 Kyodo News Service Phototelegraphic apparatus for transmitting images of film and data
US5325217A (en) * 1986-05-02 1994-06-28 Scitex Corporation Ltd. Color separation scanner

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2905897A (en) * 1955-05-16 1959-09-22 Charles J Vermilye Stroboscopic voltmeter
US3056955A (en) * 1948-10-01 1962-10-02 Dirks Gerhard Means for the visual indication of numbers and other information
US3201780A (en) * 1962-07-13 1965-08-17 Royal Mcbee Corp Code to code converters
US3229047A (en) * 1962-08-06 1966-01-11 Motorola Inc Data conversion systems
US3692935A (en) * 1971-02-17 1972-09-19 Alphanumeric Inc Single line scan pattern generator

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3056955A (en) * 1948-10-01 1962-10-02 Dirks Gerhard Means for the visual indication of numbers and other information
US2905897A (en) * 1955-05-16 1959-09-22 Charles J Vermilye Stroboscopic voltmeter
US3201780A (en) * 1962-07-13 1965-08-17 Royal Mcbee Corp Code to code converters
US3229047A (en) * 1962-08-06 1966-01-11 Motorola Inc Data conversion systems
US3692935A (en) * 1971-02-17 1972-09-19 Alphanumeric Inc Single line scan pattern generator

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4496946A (en) * 1982-09-28 1985-01-29 Peratron Corporation Programmable electronic display
US4658301A (en) * 1983-06-03 1987-04-14 Kyodo News Service Phototelegraphic apparatus for transmitting images of film and data
US5325217A (en) * 1986-05-02 1994-06-28 Scitex Corporation Ltd. Color separation scanner

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Publication number Publication date
FR2159120A5 (enExample) 1973-06-15
NL7216475A (enExample) 1973-06-13
DE2260029A1 (de) 1973-06-14
GB1381102A (en) 1975-01-22
IT982454B (it) 1974-10-21
JPS4866756A (enExample) 1973-09-12
DE2260029B2 (de) 1975-10-16

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