US3422737A - Variable font character generator - Google Patents

Variable font character generator Download PDF

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Publication number
US3422737A
US3422737A US516393A US3422737DA US3422737A US 3422737 A US3422737 A US 3422737A US 516393 A US516393 A US 516393A US 3422737D A US3422737D A US 3422737DA US 3422737 A US3422737 A US 3422737A
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Prior art keywords
character
decoder
ray tube
cathode ray
encoded
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Expired - Lifetime
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US516393A
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English (en)
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John M Bailey Jr
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Xerox Corp
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Xerox Corp
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    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/22—Apparatus for electrographic processes using a charge pattern involving the combination of more than one step according to groups G03G13/02 - G03G13/20
    • G03G15/32—Apparatus for electrographic processes using a charge pattern involving the combination of more than one step according to groups G03G13/02 - G03G13/20 in which the charge pattern is formed dotwise, e.g. by a thermal head
    • G03G15/326—Apparatus for electrographic processes using a charge pattern involving the combination of more than one step according to groups G03G13/02 - G03G13/20 in which the charge pattern is formed dotwise, e.g. by a thermal head by application of light, e.g. using a LED array
    • G03G15/328—Apparatus for electrographic processes using a charge pattern involving the combination of more than one step according to groups G03G13/02 - G03G13/20 in which the charge pattern is formed dotwise, e.g. by a thermal head by application of light, e.g. using a LED array using a CRT
    • 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
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G1/00—Control arrangements or circuits, of interest only in connection with cathode-ray tube indicators; General aspects or details, e.g. selection emphasis on particular characters, dashed line or dotted line generation; Preprocessing of data
    • G09G1/06—Control arrangements or circuits, of interest only in connection with cathode-ray tube indicators; General aspects or details, e.g. selection emphasis on particular characters, dashed line or dotted line generation; Preprocessing of data using single beam tubes, e.g. three-dimensional or perspective representation, rotation or translation of display pattern, hidden lines, shadows
    • G09G1/08—Control arrangements or circuits, of interest only in connection with cathode-ray tube indicators; General aspects or details, e.g. selection emphasis on particular characters, dashed line or dotted line generation; Preprocessing of data using single beam tubes, e.g. three-dimensional or perspective representation, rotation or translation of display pattern, hidden lines, shadows the beam directly tracing characters, the information to be displayed controlling the deflection and the intensity as a function of time in two spatial co-ordinates, e.g. according to a cartesian co-ordinate system
    • G09G1/10—Control arrangements or circuits, of interest only in connection with cathode-ray tube indicators; General aspects or details, e.g. selection emphasis on particular characters, dashed line or dotted line generation; Preprocessing of data using single beam tubes, e.g. three-dimensional or perspective representation, rotation or translation of display pattern, hidden lines, shadows the beam directly tracing characters, the information to be displayed controlling the deflection and the intensity as a function of time in two spatial co-ordinates, e.g. according to a cartesian co-ordinate system the deflection signals being produced by essentially digital means, e.g. incrementally
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G1/00—Control arrangements or circuits, of interest only in connection with cathode-ray tube indicators; General aspects or details, e.g. selection emphasis on particular characters, dashed line or dotted line generation; Preprocessing of data
    • G09G1/06—Control arrangements or circuits, of interest only in connection with cathode-ray tube indicators; General aspects or details, e.g. selection emphasis on particular characters, dashed line or dotted line generation; Preprocessing of data using single beam tubes, e.g. three-dimensional or perspective representation, rotation or translation of display pattern, hidden lines, shadows
    • G09G1/14—Control arrangements or circuits, of interest only in connection with cathode-ray tube indicators; General aspects or details, e.g. selection emphasis on particular characters, dashed line or dotted line generation; Preprocessing of data using single beam tubes, e.g. three-dimensional or perspective representation, rotation or translation of display pattern, hidden lines, shadows the beam tracing a pattern independent of the information to be displayed, this latter determining the parts of the pattern rendered respectively visible and invisible
    • G09G1/18—Control arrangements or circuits, of interest only in connection with cathode-ray tube indicators; General aspects or details, e.g. selection emphasis on particular characters, dashed line or dotted line generation; Preprocessing of data using single beam tubes, e.g. three-dimensional or perspective representation, rotation or translation of display pattern, hidden lines, shadows the beam tracing a pattern independent of the information to be displayed, this latter determining the parts of the pattern rendered respectively visible and invisible a small local pattern covering only a single character, and stepping to a position for the following character, e.g. in rectangular or polar co-ordinates, or in the form of a framed star

Definitions

  • a generating system including a cathode ray tube which is utilized in conjunction with suitable optics as a light writing source for a spaced photoreceptor, which in a preferred embodiment may comprise a sensitized xerographic drum.
  • the decoder-storage portion of the generator Under the control of input logic which may constitute a proximate or remote computer, the decoder-storage portion of the generator is initially loaded with an appropriate encoded character library.
  • the character library is in effect loaded into a specially organized recirculating delay line and thereafter continues to cyclically recirculate within this line.
  • successive bits may be gated out from the recirculating delay line to serially blank or unblank the CRT (cathode ray tube) spot as the spot sweeps a predetermined pattern.
  • the resulting alphanumeric pattern is imaged in real time on a sensitized xerographic drum and after development transferred to a paper surface or the like in accordance with standard xerographic practice.
  • FIG. 1 is an electronics block diagram for the overall character generator
  • FIG. 2 is a diagrammatic illustration of the delay line organization
  • FIG. 3 diagrammatically illustrates a typical scan pattern utilized in association with the present device.
  • a word may be referred to as comprising a specific number of bits or a portion of the delay line may be described as having a given specific number of bits reserved for a given purpose, etc.
  • a word may be referred to as comprising a specific number of bits or a portion of the delay line may be described as having a given specific number of bits reserved for a given purpose, etc.
  • the parameters cited are intended merely to concretely illustrated operation of the system and are not in any way intended to delimit the invention otherwise described.
  • digitally encoded data is fed to and from the decoderstorage section 3 of the character generator by the input logic at 1.
  • the latter provides, in a stream which will be shown to be appropriate for the system, all the digitally encoded loading data utilized in generation, and also provides the encoded character data that subsequently initiates and controls generation of the characters.
  • the input logic 1 may well compiise a digital computer and need not in fact be in close proximity to the remainder of the system.
  • the input logic could include a remote digital computer connected to a proximate data set interface by standard telephone transmission lines and a standard dataphone.
  • the relative proximity of the input logic is not significant to the operation of the system except to the extent that where telephone lines intervene the data flow rate is necessarily limited by the capabilities of these transmission lines.
  • decoding action of the elements contained within decoder storage section 3 is such as to convert a relatively low bit encoded character into a serial stream of considerably more numerous bits which are then used to blank or unblank the electron beam of CRT 15 as it scans a prescribed path.
  • a 7 bit encoded character (contained in say a 10 bit transmitted word) is so converted into a serial stream of 84 bits.
  • the decoder consists of the recirculating delay line 4 whichpurely for purposes of illustration-may be considered as a 5 miliisecond magnetostrictive delay line capable of storing 10,000 NRZ (non-return to zero) hits at a clock rate of 2 mc./s.
  • timing circuits functionally contained within load logic 2 gate the incoming encoded data into the recirculating delay line 4 in proper time sequence.
  • FIGURE 2 A graphic depiction of the organization of the loaded delay line 4 is shown in FIGURE 2.
  • the delay line is organized during loading with an initial section, such as 45, illustratively shown as containing 128 bits, which acts as a synchronization Word to indicate the reference point after which the encoding data will start.
  • the sync bits contained in section 45 are loaded into the delay line in the same manner as the character encoding data.
  • each of the successive segments 46, 47 and so forth is broken up into as many hits as corresponds to the number of characters used in a character set.
  • each of the segments 46, 47 and so forth is broken up into 110 such bits. The order in which these bits are located within each particular segment corresponds to the code which represents the character.
  • the 65th bit in the segment 46 which is identified in FIGURE 2 by the numeral 465, will be the first bit required to display the character A.
  • the 65th bit in segment 47 which is therein identified by the numeral 5, l be the second bit required to display the character A, and so forth, until finally the 84th segment of bits is reached wherein again the 65th bit, identified in FIGURE 2 by the numeral 495, represents the 84th bit required to display the same character.
  • a final segment, spatially adequate for an unspecified number of bits, is provided. This segment is not utilized operationally but is rather reserved to provide extra space in the event the character font is increased numerically.
  • the manner in which the organized delay line is utilized to achieve character generation may now be set forth. More particularly, encoded characters originating at input logic 1 are routed to the decoder-storage portion of the generator and are compared to the state of a counter within the write logic 5 which keeps a count of the data bits in the delay line following the sync segment 45. Whenever a match exists-which will occur once in every segmentthe bit is gated out of the delay line 4 by the write logic and is held at the beam modulator 10 while blanking or unblanking the CRT 15 beam depending upon its binary value.
  • the write logic 5 in addition to providing appropriate data manipulation signals in response to the encoded character generating data transferred from input logic 1 also generates the required scan start-stop signals for the pattern generator 6. Characters and symbols are generated on the face of CRT 15 by modulation of the electron beam as it is deflected, under control of pattern generator 6, through a fixed line pattern. This pattern, illustratively shown in FIG. 3, is repeated for each character or symbol.
  • the total scan timeas has been previously discussedis arranged to be slightly less than the circulation period of the delay line 4, so that the scanning beam can be appropriately blanked by the serial bit data stream from the decoder-storage section 3.
  • the pattern generator 6 is seen to act through the X and Y deflection amplifiers at 7 and 8 respectively.
  • the latter are desirably direct-coupled feed-back amplifiers. They provide a low impedance drive to the deflection yoke 9 for accurate positioning of the electron beam.
  • the deflection yoke 9 used in conjunction with the CRT is a standard unit and typically is a single ended unit of flat field characteristics exhibiting a spot recovery time of the order of four microseconds.
  • the initial position of the first character formed on the face of CRT 15 is controlled through the use of initial beam positioning circuits contained within pattern generator 6 and controlled by input logic 1.
  • the pattern generator circuitry skips the electron beam to the scan-start position of the following character. This introduced a spacing between characters.
  • the input logic is programmed to send the generator a character code which has been previously encoded and entered into the recirculating delay line as a complete blank. That is to say, the CRT beam is blanked throughout the scan period.
  • each such line is imaged through conventional optics 16 upon the photoreceptor 17.
  • the latter may most conveniently take the form of a sensitized xerographic drum rotatable about an axis transverse to the axis of CRT 15. Assuming in FIG. 1 that the photoreceptor does take such form, an indexer is provided at 18 for advancing the drum stepwise one line at the completion of each transverse line of characters. It may be noted that this index is in electrical connection with input logic 1, the latter supplying signals to actuate the indexing operation.
  • Charge sensitization means for the drum are not shown but are completely conventional. Neither are development means or means for transferring the developed latent electrostatic image to paper or the like shown since these subsequent xerographic techniques are fully described in numerous places and are considered completely obvious to those skilled in this art.
  • character generation capabilities of the present system are in no way limited to the photoreceptor printout type of unit being particularly considered herein.
  • the character generation technique described is, on the contrary, a generalized scheme that may be readily seen to have the widest applications. That technique is seen to include the concept of organizing a delay line into successive, and in turn sub-organized, segments. Thereafter character generation is achieved by serially gating out successive corresponding bits in the successive segments, as such segments cyclically circulate in a closed loop.
  • the makeup of the recirculating delay line 4 that is to say its organization-may be completely changed in an extremely short period.
  • the organization of the delay line- which in effect means the character font loaded in the line-may be completely changed in the order of four and one-half seconds even in such instances where data flow is limited by telephone transmission lines to 2,000 bits per second.
  • the loading of the delay line will be time limited only by the recirculation period of the line itself.
  • the improved apparatus including a variable font character generator, said character generator comprising input logic means;
  • recirculating decoder-storage means adapted for storing encoded character fonts transmitted from said input logic means, said recirculating decoder-storage means being further adapted to respond to encoded signals representative of said stored encoded characters and presented to said recirculating decoder-storage means by selectively gating out electrical signals indicative of the characters corresponding to said encoded signals;
  • pattern generator means electrically connected to said decoder-storage means and said cathode ray tube, said pattern generator means including circuitry for establishing a fixed scan pattern on the face of said cathode ray tube, said pattern generator means further including circuit means for intensity modulating said scan pattern in accord with said electrical signals from said decoder-storage means whereby light patterns may be formed upon said cathode ray tube representative of said characters.
  • said decoder-storage means comprises a serially organized recirculating delay line, load logic means, and write logic means
  • said load logic means being electrically positioned and adapted to serially load successive digitally organized segments into said delay line from said input logic, individual bits in each of said segments being thereby positioned at assigned points in the said segment corresponding to a given character in the said font, correspondingly positioned bits in successive segments having binary state values in accord with those necessary to blank or unblank said fixed scan pattern on the face of said cathode ray tube when said values are 'made to intensity modulate said pattern in synchronization with said scan, said delay line being adapted to cyclically recirculate said segments, said write logic being electrically positioned and adapted to gate out from said delay line a series of binary state valued signals identical to those stored in said delay line at said identical assigned points in said successive segments upon receipt from said input logic of the said encoded signal representative of the character to which the said assigned points correspond.
  • a variable font character generator comprising a cathode ray tube for displaying light patterns on the face thereof,
  • pattern generator means electrically connected to said decoderstorage means and said cathode ray tube for establishing a fixed scan pattern on the face of said cathode ray tube, said pattern generator means further including circuit means for intensity modulating said scan pattern in accordance with said electrical signals from said decoder-storage means whereby light patterns may be formed upon said cathode ray tube representative of said characters.
  • said decoder-storage means comprises a serially organized recirculatin delay line, load logic means, and write logic means
  • said load logic means being electrically positioned and adapted to serially load successive digitally organized segments into said delay line from said input logic, individual bits in each of said segments being thereby positioned at assigned points in the said segment corresponding to a given character in the said font, correspondingly positioned bits in successive segments having binary state values in accord With those necessary to blank or unblank said fixed scan pattern on the face of said cathode ray tube when said values are made to intensity modulate said pattern in synchronization with said scan, said delay line being adapted to cyclically recirculate said segments, said Write logic being electrically positioned and adapted to gate out from said delay line a series of binary state valued signals identical to those stored in said delay line at said identical assigned points in said successive segments upon receipt from said input logic of the said encoded signal representative of the character to which the said assigned points correspond.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Computer Hardware Design (AREA)
  • Theoretical Computer Science (AREA)
  • Controls And Circuits For Display Device (AREA)
  • Combination Of More Than One Step In Electrophotography (AREA)
US516393A 1965-12-27 1965-12-27 Variable font character generator Expired - Lifetime US3422737A (en)

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US51639365A 1965-12-27 1965-12-27
US51665765A 1965-12-27 1965-12-27

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US516657A Expired - Lifetime US3457371A (en) 1965-12-27 1965-12-27 Dataphone driven remote graphic display system

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DE (1) DE1524507A1 (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)
FR (1) FR1506176A (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)
GB (1) GB1162840A (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)
NL (1) NL6618068A (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3582946A (en) * 1967-09-28 1971-06-01 Nippon Electric Co Cathode-ray tube display device
US3678497A (en) * 1970-12-17 1972-07-18 Int Standard Electric Corp Character generation system having bold font capability
US3706905A (en) * 1970-05-14 1972-12-19 Computer Terminal Corp Deflection compensation system
US3786478A (en) * 1972-08-17 1974-01-15 Massachusettes Inst Technology Cathode ray tube presentation of characters in matrix form from stored data augmented by interpolation
US4060322A (en) * 1974-07-10 1977-11-29 Canon Kabushiki Kaisha Image information handling device
US4580231A (en) * 1978-09-15 1986-04-01 Alphatype Corporation Ultrahigh resolution photocomposition system employing electronic character generation from magnetically stored data

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3618035A (en) * 1969-04-17 1971-11-02 Bell Telephone Labor Inc Video-telephone computer graphics system
US3706850A (en) * 1971-04-23 1972-12-19 Bell Telephone Labor Inc Telewriting system
US3822363A (en) * 1972-08-09 1974-07-02 Digi Log Syst Inc Portable computer terminal using a standard television receiver
US3746793A (en) * 1972-08-09 1973-07-17 Phonics Corp Telephone communication system for the hearing impaired
FR2426295A1 (fr) * 1978-05-18 1979-12-14 Thomson Csf Generateur de symboles pour console graphique
JPS57174768A (en) * 1981-04-17 1982-10-27 Sharp Corp Information retrieving device
JPS61147677A (ja) * 1984-12-21 1986-07-05 Mitsumi Electric Co Ltd ス−パ−インポ−ズ装置

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2594731A (en) * 1949-07-14 1952-04-29 Teleregister Corp Apparatus for displaying magnetically stored data
US2624798A (en) * 1948-03-23 1953-01-06 Mergenthaler Linotype Gmbh Photocomposing machine
US2762862A (en) * 1951-03-01 1956-09-11 Rca Corp Electronic character selecting and/or printing apparatus
US2952796A (en) * 1957-05-13 1960-09-13 Dick Co Ab Electrostatic printing tube
US3258201A (en) * 1964-11-19 1966-06-28 Internat Typographical Union O Photocomposing apparatus including font deletion and font change interlock means
US3283317A (en) * 1963-06-14 1966-11-01 Sperry Rand Corp Symbol generators

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Publication number Priority date Publication date Assignee Title
US3278683A (en) * 1962-09-27 1966-10-11 North American Aviation Inc Character beam generating systems
US3320409A (en) * 1963-01-30 1967-05-16 Burroughs Corp Electronic plotting device
US3323119A (en) * 1963-12-30 1967-05-30 Ibm Display system for a data processing unit
US3325802A (en) * 1964-09-04 1967-06-13 Burroughs Corp Complex pattern generation apparatus

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2624798A (en) * 1948-03-23 1953-01-06 Mergenthaler Linotype Gmbh Photocomposing machine
US2594731A (en) * 1949-07-14 1952-04-29 Teleregister Corp Apparatus for displaying magnetically stored data
US2762862A (en) * 1951-03-01 1956-09-11 Rca Corp Electronic character selecting and/or printing apparatus
US2952796A (en) * 1957-05-13 1960-09-13 Dick Co Ab Electrostatic printing tube
US3283317A (en) * 1963-06-14 1966-11-01 Sperry Rand Corp Symbol generators
US3258201A (en) * 1964-11-19 1966-06-28 Internat Typographical Union O Photocomposing apparatus including font deletion and font change interlock means

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3582946A (en) * 1967-09-28 1971-06-01 Nippon Electric Co Cathode-ray tube display device
US3706905A (en) * 1970-05-14 1972-12-19 Computer Terminal Corp Deflection compensation system
US3678497A (en) * 1970-12-17 1972-07-18 Int Standard Electric Corp Character generation system having bold font capability
US3786478A (en) * 1972-08-17 1974-01-15 Massachusettes Inst Technology Cathode ray tube presentation of characters in matrix form from stored data augmented by interpolation
US4060322A (en) * 1974-07-10 1977-11-29 Canon Kabushiki Kaisha Image information handling device
US4580231A (en) * 1978-09-15 1986-04-01 Alphatype Corporation Ultrahigh resolution photocomposition system employing electronic character generation from magnetically stored data

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GB1162840A (en) 1969-08-27
NL6618068A (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html) 1967-06-28
DE1524507A1 (de) 1970-08-13
FR1506176A (fr) 1967-12-15
US3457371A (en) 1969-07-22

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