US3741086A - Cyclic drum printer - Google Patents

Cyclic drum printer Download PDF

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Publication number
US3741086A
US3741086A US00290050A US3741086DA US3741086A US 3741086 A US3741086 A US 3741086A US 00290050 A US00290050 A US 00290050A US 3741086D A US3741086D A US 3741086DA US 3741086 A US3741086 A US 3741086A
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United States
Prior art keywords
page
drum
reproduction system
paper
images
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Expired - Lifetime
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US00290050A
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English (en)
Inventor
M Markakis
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Smith Corona Corp
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SCM Corp
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Publication of US3741086A publication Critical patent/US3741086A/en
Assigned to SMITH CORONA CORPORATION, 65 LOCUST AVENUE, NEW CANAAN, CT 06840 A DE. CORP. reassignment SMITH CORONA CORPORATION, 65 LOCUST AVENUE, NEW CANAAN, CT 06840 A DE. CORP. ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: SCM CORPORATION
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Expired - Lifetime legal-status Critical Current

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/385—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by selective supply of electric current or selective application of magnetism to a printing or impression-transfer material
    • B41J2/425—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by selective supply of electric current or selective application of magnetism to a printing or impression-transfer material for removing surface layer selectively from electro-sensitive material, e.g. metal coated paper

Definitions

  • ABSTRACT High quality non-impact printing based on transfer of images from a revolving font drum to a page blank carried by a receptor drum rotating with the same surface velocity as the font drum, but processing with respect to the former, the images being developed upon transfer of a full page of information to the blank.
  • the receptor drum can have an image-receiving surface for intermediate storage of images and subsequent transfer of these images to a page blank for visual development or subsequent visual development and transfer of the visible images to a page blank.
  • the present invention relates to printing, and more particularly to apparatus for providing high quality printing using a nonimpact technique. Imaging operations upon a blank sheet of paper are carried out in successive cycles along a fixed path with characters at sequential printing stations being selectively imaged upon the sheet-at different lines in each cycle, the blank being advanced one line during each successive cycle art, such as U. S. Pat. No. 2,919,967, has shown systems having high speed drums moving past relatively slow speed paper with the result that the copy does not achieve maximum'quality.
  • the apparatusaccording to the invention differs from such previous methods or apparatus in that the relative velocity of font and paper is zero in the area of print, thus producing no smear.
  • a principal object of the invention is to provide a page reproduction system having a number of reproduction stations, each station containing at least one discrete character generator, the character generators defining a curved surface and being spaced at equal intervals along the surface, together with a curved member record medium of particular length adjacent the surface, drive means for substantially equal velocity movement of the curved member and the surface in a series of cycles, the drive means precessing the record medium through a distance equal to one interval during each cycle, means forming images on the record mediumin response toselective operation of the character generators during any cycle, and means for developing the images after a number of cycles sufficientto' have presented each character generator over the length of the record medium.
  • a further object of the invention is to provide apparatus for imaging a large amount of information in successive stages on a blank sheet of paper, the fullyimaged page being subsequently developed.
  • Yet another object of the invention is to provide page printing apparatus for imaging in successive stages different and/oroverlapping areas on any sizeblank page, the fully-imaged page being subsequently developed.
  • a still further object of the invention is to provide a multi-stage printing mechanism having a rotatively mounted drum, which carries a blank page in successive cycles along a closed path past a plurality of printing stations, successive'lines of the blank page .being presented'to successive ones of the printing stations in each cycle, and the blank page being precessedone line during each cycle.
  • FIG. 1 shows the geometricrelationship between the two drums, transfer timing, and paper feed and release according to the invention with portions cut away for the purpose of showing as many elements as possible;
  • FIG. 2 shows a combined block diagram and pictorial of an electronic system that will work with the disclosed cyclic printer capable of reproducing all of the alphabetical symbols, as well as the decimal digits, blanks, and other selected and desired characters, such as 0, etc.
  • FIG. 1 thereis disclosed a cyclic drum printer capable of reproducing a page of information by imaging any one of the characters on a multiplicity of character fonts 6 at desired locations on a sheet of dielectric paper 7.
  • Printer 60 is arranged to print, line-by-line, any of 96 characters 6b on each of fonts 6, the characters being arranged in parallel rows 6a, for example.
  • the information may be a computer output taking the form of a 7 bit binary code using 96 of the 128 available combinations, each representative of a different one of the characters 6b on fonts 6. It is to be understood that this arrangement is merely illustrative of the invention, and that, if desired, one may use a greater or smaller number of fonts 6 in each row 6a and characters 6b.
  • the reproduction elements of cyclic drum printer 60 consist of two separate drums (refer to FIG. 1): a font drum 3 which has a number of columnar characters on fonts 6 presented sequentially to a receptor drum 1.
  • the characters on fonts 6 may be alphabetic, numeric, and special symbols suchas periods, commas, mathematical symbols, etc.
  • Arrangement of characters 6b on the fonts 6 across the rows 6a is singular in kind all A's, all Bs, etc. Accordingly,each character font 6 of drum 3 includes 96 distinct elements 6b in columnar alignment; hence, font drum 3 has a circumferenceof 96 units of length. If the distance along each unit is onesixteenth inch, corresp onding to the standard line spac a complete revolution every 100 milliseconds, to avoid need for precision balancing, although the printer could be operated at much higher speeds if desired.
  • Drum 1 supports the sheet of d electric paper 7 having a multiplicity of lines 7a on which selected charac-
  • Receptor drum 1 may be located such that there is a slight separation between its surface and that of drum 3 (see FIG. 2) and is arranged by means of gearing to run in a direction such that the relative surface velocity between the two drums is zero. Di meters and gears are chosen to cause the surface of drum 1 to advance one line space (one-sixteenth inch) per reyolution relative to the surface of'drum 3.
  • receptor drum 1 has, in this example, a circumference of units .of length, of 15 5/6 inches.
  • a gear 4 having 96 teeth is attached to .drum 3 and an .engaginggetlrfi ;hav-
  • each unit of length on drum 3 will be placed opposite to or, as will be seen, in contact with each unit of identical length on drum 1 in 95 revolutions of drum 3, according to the following relation:
  • N number of teeth and R number of revolutions.
  • characters of fonts 6 are available sequentially at corresponding positions in 84 lines 7a on paper 7, and are imaged as required.
  • line 1 of paper 17 there would be imaged the As in that line of the text, on line 2, the Bs in this next line of the text; on line 3, all the Cs in this subsequent line of text, etc. Since there is a difference in circumference between drum 3 and drum 1, then at the end of the first revolution of drum 3 line 1 would be presented with the 96th character of fonts 6; and during the second revolution of drum 3: line 2, all the A's; line 3, all Bs, etc.
  • any of the 96 characters 6b could have been imaged in all 80 positions of each line 7a, and'thus on the entire page '7. It should be noted that imaging of more than one character 6b within a given position on line 7a can be accomplished with this system, superposition of symbols permitting use of diacritical marks; underscoring, etc.
  • comparison data can be shifted into another register in drum 3 for control of character imaging onto paper 7 on 'drum 1, asdescribed below. It should be noted at this time that character comparison and shifting occur at electronic speeds during the time when gap 60 between successive characters 6b of each font 6 is adjacent to paper 7 on drum 1.
  • a selected font 6 of font drum 3 will have a high voltage placed upon it at the instant when transfer of a particular character 6b is to be made.
  • the font 6 in one-column must be isolated from those in adjacent columns so that there will be selectability as to thefont 6 where transfer is to be made.
  • dielectric paper 7 it must be conductive on the side in contact with drum 1 and have a-thin dielectric coating (not shown), preferably in contact with drum 3 (or closely spaced thereto) for acceptance of imaging charges.
  • the paper may be similar to coated paper Type 563 made by the Plastic Coatings Corp., Holyoke, Massachusetts and Forest paper, Type 566, supplied by Varian Corp., Palo Alto, California. On such paper, the best reproducibility is found with a voltage difference of about 700 volts to 800 volts when using liquid toners such as disclosed in U. S. Pat. Nos.
  • the layer 2 must also be conductive and of a thickness such that the surface 7b of paper 7 makes a light contact with the'tops of the characters 6b on fonts 6, as shown in FIG. 1.
  • the high voltage drivers can be simple switching transistors such as, say, the 2N5015 of the NPN type connected in common emitter configuration with 800 volts applied to collector load resistors.
  • Drum 1 and fonts 6 of drum 3 can be connected to respective ends of the resistors, and the transistor bases connected to appropriate parallel outputs of the shift register.
  • the ground reference 47 on receptor drum 1 can remain constant, whereas the high voltage applied to selected fonts 6 of drum 3 must be switched on and off.
  • the current path for voltage system 8 is through font drum 3, to the selected character fonts 6', to the, surface 7b of paper 7, then through the paper capacitance to layer 2 (i.e., to drum 1) where a return path connection 48 is provided back to high voltage system -8.
  • Print command signal 43 originates with the operator when, say, a computer output is to be printed.
  • the location of markers 44 and 45, and the drive interconnection of drums l and 3, are such that a paper edge signal 42 and any one of a number of font position input signals 40 occur substantially at the same time. This is done so that imaging will not be started at midposition on any character ro'w 7a. Note further that this arrangement will also allow printing to start at any character position of fonts 6.
  • the printing cannot start until there is a sensing of a font start index marker 46 as will be discussed subsequently.
  • Print command 43 feeds an input signal to quantizer 10 which synchronizes all signals.
  • This output of quantizer 10 sets print page flip-flop 11.
  • Set output 11a of print page flip-flop 11 is an input to start print gate 14, along with signal 13a from an amplifier/Schmidt trigger 13. Simultaneous concurrence of the two signals, 11a and 13a, will give an output 14a, which sets a print latch (or flip-flop) 15 to allow imaging of the selected character 6a as will be shown and discussed below.
  • Output 140 starts a divide-by-96 counter 12, which is at count zero at the beginning of every print operation.
  • An output signal 12a is obtained when divide-by-96 counter 12 reaches the value 96, terminating further imaging of characters 6b.
  • a font position input signal 40 is developed when each character font marker 45 is in proximity with font position input generator 40a. The function of font position input signal 40 will be discussed below. Each character font marker 45 is aligned with the angular position of a particular character row 6a.
  • the manner of sequentially selecting the proper character font 6 at the particular character row 6a desired involves the use of digital electronics techniques, such as magnetic, optical, etc. controls. This is accomplished in my embodiments when a marker 44 comes in proximity with the paper edge input generator 42a. Paper edge marker 44 is set on drum 1 in such a location as to allow a margin at the top of paper 7 before imaging the first line'7b. Paper edge input generator 42a generates the above-mentioned paper edge signal 42 which goes to amplifier/Schmidt trigger 13 to create a fast rise/fall pulse 13a of appropriate amplitude. f
  • a 'font start signal 41 is produced by a font start index generator 41a upon sensing a marker 46 which establishes the beginning position of font drum 3. Signal.41 is generated just prior to A row 6a. Font start" signal 41 is sent to an amplifier/Schmidt trigger 16,
  • Output signal 16a of trigger 16 is then fed to a quantizer 17, which synchronizes all signals with the system clock 39 in the same fashion as does quantizer 10.
  • Output signal 17a from quantizer 17 sets a binary font counter 20 to zero.
  • font position input signal 40 occurs through trigger 18, as timed by quantizer l9, font counter 20 starts to count beginning at zero and ending with 96. Each count is sent. to a reference character translator 21 by seven output lines 20a from font counter 20.
  • Reference character transla- 1 tor 21 is needed when the code used for the date in main memory 29 is not the same as in font counter 20.
  • Each count from font counter 20 is translated into one of the 96 reference characters by reference character translator 21, the output of which is sent to a character comparator 30.
  • the reference character generated by font position input signal 40 can be compared with memory characters shifted to character comparator 30.
  • Main memory 29 holds an entire page of information to be imaged.
  • a page can contain 84 lines having character positions per line with the possibility of any one of 96 different characters being in a given position.
  • main memory 29 will be preferably a dynamic circulating memory.
  • Memory information is obtained through various networks of input data fed in parallel, say, to a memory gating system 28 working synchronously with a memory control system 23.
  • the inputs to this system 23 are a system clock 39, the font position input signal 40, and an address counter 22.
  • the concurrence of the output signal 23a from memory control 23 and system clock 39 allows memory clock 24 to start running and feed a signal 24a to step main memory 29, character by character and line by line until the entire page has been scanned.
  • address counter 22 therefore acts as a control for main memory scanning. Address counter 22 will allow only the proper line from memory 29 to be compared in character comparator 30.
  • a signal from character comparator 30 is sent to output clocking and control 27.
  • Output clocking and control 27 is operated jointly by address counter 22, system clock 39, character comparator 30, and the output signal 15a from print latch 15, assumed to be present at this time. Because the system can compare 84 lines of a page, a line counter 26 is started by a signal 27a from output clocking and control 27. Of course, before the signal 27a from output clocking and control 27 is presented to the line counter 26, this last is set to a count of zero by the gating control 25 for signals 40a and 15a. Another of the functions of output clocking and control 27 is to allow only the proper number of character comparisons from comparator 30 to be used for imaging of each line.
  • a comparison storage buffer 31 receives inputinformation from character comparator 30 serially, one bit as each memory character is compared tronic elements discussed previously by means of brushes and slip rings indicated symbolically (FIG. 2) at 49 and 50.
  • High voltage power receiver 35 is activated by a signal coming from high voltage power control 33. Receiver 35, in turn, sends an output, but only after shift register 37 has received all 80 bits of information through data receiver 36 as supplied by output driver 34. Shift register 37 is, in effect, a serial-to parallel converter. It receives information serially and supplies it in parallel so that information for one line can be presented selectively to high voltage drivers 38.
  • shift register 37 and high voltage power receiver 35 will then be presented to high voltage drivers 38, comprised of 80 separate drivers, each representing a particular position within the writing line.
  • Each driver 38 is connected by one of the leads 51 to a corresponding one of the fonts 6. Therefore, 80 character positions'of line 7a could be imaged at one time, should the same character be present in all positions.
  • Each of the high voltage drivers 38 will be activated during the imaging of one character 6b starting with paper 7 near the top of the character and ending near its bottom, as drums 3 and 1 rotate.
  • the invention is not confined to the configuration described as the preferred embodiment. Alternate configurations or modifications to the imaging apparatus and system of producing copies may be employed. Such modifications are, say, applying well-known electrostatigraphic techniques which can use a wet or dry toner. For instance, electrostatic charge patterns on drum 3 could be deposited directly upon a dielectric material forming the surface of drum 1. Then the charge pattern could be either toned and the toned image transferred to bond paper; or the-electrostatic charge pattern could be transferred to a 'copy'paper for later toning, as is known. Another possible modification would be the use of an optical imaging apparatus for drum 3, cooperating with a photoconductive element on drum 1.
  • each said station containing at least one discrete character generator, said character generators defining a curved surface and being placed at equal intervals along saidsurface, the combination of a curved member supporting a record medium of particular length adjacent said surface, drive means for equal velocity movement of said member and said surface in a series of cycles, said drive means precessing said record medium through a distance equal to one of said intervals during each said cycle,
  • said character generators comprise opaque symbols in columnar arrangement on the transparent surface of a first cylindrical drum
  • said curved member is a second cylindrical drum having as said record medium a photoconductive element on the periphery thereof andbeing axially spaced from said first drum
  • said means forming images comprise a source of electrostatic charges for forming a uniform charge layer on the photoconductive element and a plurality of light sources, each cooperating with a respective column of said symbols and selectively operable to illuminate desired ones of said symbols, including blanks, in each saidcolumn
  • said means for forming visible images include. toning and transfer means.
  • said curved member is a cylindrical drum having as said record medium a dielectric material on the surface thereof, said means for forming visible copies of the images comprises paper fed past said dielectric material and further including means providing resilient contact between the dielectric material and said font wheels.
  • said resilient contact means comprises a resilient conductive layer intermediate said dielectric material and said drum

Landscapes

  • Printers Or Recording Devices Using Electromagnetic And Radiation Means (AREA)
  • Electrophotography Using Other Than Carlson'S Method (AREA)
  • Fax Reproducing Arrangements (AREA)
  • Combination Of More Than One Step In Electrophotography (AREA)
US00290050A 1972-09-18 1972-09-18 Cyclic drum printer Expired - Lifetime US3741086A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US29005072A 1972-09-18 1972-09-18

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US3741086A true US3741086A (en) 1973-06-26

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US (1) US3741086A (ja)
JP (1) JPS561234B2 (ja)
CA (1) CA993033A (ja)
CH (1) CH571407A5 (ja)
DE (1) DE2318719A1 (ja)
FR (1) FR2199691A5 (ja)
GB (1) GB1409453A (ja)
IT (1) IT980201B (ja)

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0317897U (ja) * 1990-06-28 1991-02-21
JP5779845B2 (ja) * 2010-03-25 2015-09-16 富士ゼロックス株式会社 画像形成装置、及び画像形成ユニット

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IT980201B (it) 1974-09-30
CH571407A5 (ja) 1976-01-15
GB1409453A (en) 1975-10-08
DE2318719A1 (de) 1974-04-04
CA993033A (en) 1976-07-13
FR2199691A5 (ja) 1974-04-12
JPS561234B2 (ja) 1981-01-12
JPS4980933A (ja) 1974-08-05

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Legal Events

Date Code Title Description
AS Assignment

Owner name: SMITH CORONA CORPORATION, 65 LOCUST AVENUE, NEW CA

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:SCM CORPORATION;REEL/FRAME:004810/0544

Effective date: 19870804