|Publication number||US3681777 A|
|Publication date||Aug 1, 1972|
|Filing date||Aug 28, 1970|
|Priority date||Aug 28, 1970|
|Publication number||US 3681777 A, US 3681777A, US-A-3681777, US3681777 A, US3681777A|
|Inventors||Smura Edwin J|
|Original Assignee||Xerox Corp|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (6), Referenced by (5), Classifications (10)|
|External Links: USPTO, USPTO Assignment, Espacenet|
United States Patent Smura [451 Aug. 1,1972
 RECORDING APPARATUS  Inventor: Edwin J. Smura, Webster, NY.
 Assignee: Xerox Corporation, Stamford,
 Filed: Aug. 28, 1970 21 App1.No.: 67,811
 U.S. Cl. ..346/74 CR, 178/67 A, 346/74 ES, 346/74 P, 355/72  Int. Cl. .....G03b 27/10, G03g 15/00, H04n 5/80  Field of Search ..346/74 CR, 74 ES, 74 P; 178/67 A; 355/72 [5 6] References Cited UNITED STATES PATENTS 3,571,503 3/1971 McMann ..178/6.7 A 3,210,597 10/1965 Siegmund ..346/74 CR 3,446,554 5/1969 Hitchcock ..355/77 3,457,070 7/1969 Watanabe ..346/74 ES X 3,124,457 3/1964 Schwertz ..346/74 P 3,395,401 7/1968 Silverman ..346/74 CR Primary Examiner-Howard W. Britton Attorney-James J. Ralabate, John Beck and Laurence A. Wright [5 7 ABSTRACT A high speed recording apparatus capable of recording signal intelligence from a cathode ray tube. Drive means are provided comprising a plurality of rollers to press discrete areas of a record web against the fiber optic face plate of the cathode ray tube in synchronism with beam sweep. This action eliminates page incrementing lapse time while at the same time data is continuously recorded on the record web. The recorded data, at a processing station, may be transferred from the record web and a copy obtained.
22 Claims, 3 Drawing Figures PATENTEDMJB I ma INVENTOR EDWlN J. S
GYM a. n 2, ATTORNEY RECORDING APPARATUS This invention relates to a high speed recording apparatus capable of recording signal intelligence from a cathode ray tube.
BACKGROUND OF THE INVENTION In processing information in numerical, alphabetical or special character form from a computer or other high speed data source, the weakest link in the final stage of processing such data has been the mechanical printers. In order to take full advantage of the high speed capability of present day data processing devices, the output printer for such devices must be equally capable of high speed performance. Many attempts have been made, some successful, to improve the speeds of mechanical printers. However, the very nature of these devices, for example, mechanical inertia sets an upper limit on their speed capability.
Conventional printers employ a large number of mechanical printing members such as hammers and type members. The useof this kind of structure results in printers which are not only bulky but also expensive. In these conventional printing devices, printing is done by mechanical action between the typeforming means and the paper or printout form. That is, an entire character line is mechanically printed rapidly while the printout form is stopped, then the form is rapidly advanced for printing the next succeeding line. For high speed printing, the intermittent movement of the form at a very rapid speed creates very difficult problems. Additionally, this mechanical action at a high rate of speed causes an undesirable noise level and wear is inherent, thus causing extensive down-time for replacement and repair of the 'mechanical devices.
The present invention is a 10,000 line per minute hard copy printer of high quality which overcomes the aforesaid problems of conventional printers. General approaches to accomplish this result would be among the following:
1. Mechanical impact or spark discharge type printer with printing on a line increment basis.
2. Mechanical impact or spark discharge type printers but with multiple line units so as to increment mechanically several lines at a time.
3. Full page recording with page incrementing at:
a. full size.
b. micro-image with full size obtained with a reproducer of some sort.
0. intermediate size with full or micro-size obtained by a reproducer or the like.
4. The same as (3) but line at a time incrementing.
Present day mechanical printer technology limits place carriage advance time at about 5X10 seconds per line leaving about 1 l0"" seconds to print a line in system 1) above. It is readily seen that this is not a very feasible system unless it is limited to characters per font or columns per page in such a manner as to allow printing in seconds.
System (2) is feasible but costly since multiple print units must be used together with multiple drives. If this system is tied to a computer the buffering must also be duplicated. Roughly, the increase in cost will be directly proportional to the number of lines printed per carriage advance. Since 1,500 lines per minute is the limit of some known printers at 10,000 lines per minute (1pm) it could be expected to cost about six times as much. Again, this is not a very good system.
Printers such as system (4) above have the same problems and disadvantages already mentioned with regard to systems (1) and (2) but to a lesser extent possibly, but now precision incrementing is necessary for less than full size format. At full size the same problems are directly encountered, as the system is the same as systems l) or (2).
System (3) then remains as the only technically feasible and reasonably priced system provided that the number of hammers, sparks, gaps, etc. are kept to a minimum. One way in which this can be done is by utilizing a cathode ray tube. The cathode ray tube can I be considered analagous to a single hammer having motion in the X and Y planes.
Present technology using light optics prevents a cathode ray tube system from having good resolution and aesthetic appeal. The reasons for this are the following:
l. Use of a lens in the micro mode severely limits the ultimate resolution; for example at 15 or 20 reduction the image spread function is about one-half mil at 50 percent intensity prints. This results in about 2 or 3 line pairs per millimeter in a character at full size whereas 5 to 10 are needed: and
2. A lens between the CRT and the receptor can transmit only about 1 or 2 percent of the energy from a CRT. This loss of energy results in the exposure time being unduly long. For single (point) source CRTs this means a matrix or vector type of character must be printed. High printer speed and long exposure time mean that the detailed bits per character must be small resulting in poor character appearance. For parallel source CRT (compositron or charactron) the cathode current or electro-optic resolution limit resolution or speed so as to eliminate their use in this application.
While there are materials with high sensitivity to compensate for lens losses they are expensive and require considerable processing to develop the latent image. For a commercial system this is a very severe drawback.
The use of a CRT in very near contact or contact with the receptor is a feasible way of overcoming the problem described. This means that the CRT face should be a fiber optic face plate. The system proposed is such a system. It has the advantage that the time per line advance (beam movement) is about 10 microseconds and the time for page advance is zero in receptor movement and 10 microseconds approximately in beam movement.
high speed recording apparatus which is mechanically simple and reasonably inexpensive.
BRIEF DESCRIPTION OF INVENTION In a first embodiment of the invention the recording apparatus comprises a cathode ray tube having signal intelligence applied to the input circuits thereof. Attached to the face of the cathode ray tube is a fiber optic plate. The fiber optic plate is positioned so as to concentrate the light of the cathode ray tube onto a photosensitive surface or record medium. The photosensitive surface takes the shape of an endless belt wrapped around a plurality of rollers. The rollers are positioned and actuated in conjunction with beam movement such that a portion of the belt is always in contact with the face of the cathode ray tube with the result that there is zero page advance time. 'Means are provided to develop the image on the belt and to transfer the image to a permanent surface. In a second embodiment of the invention the photosensitive surface is fed from a supply reel onto a take-up reel and is developed either in a vacuum, partial vacuum, or air.
The nature of the present invention having been set forth, there will now be presented a more detailed description in illustration but not limitation of the in vention in the following specification and drawings in which:
FIG. 1 is a schematic view showing the basic elements of the recording apparatus;
FIG. 2 is a view similar to FIG. 2 showing details of the processing station; and
FIG. 3 is a view similar to FIG. 1 showing a reel supply record medium.
In FIG. 1 a cathode ray tube 11 converts the signal intelligence from input circuits into suitable form to create character images on record web or belt 16. Input circuits 10 may be responsive to code signals and may comprise translators, gates, and amplifiers in order to generate the potentials necessary to produce the character images to be displayed on the face of cathode ray tube 11. Input circuits 10 may also supply signals according to a predetermined time base to drive the record rollers and to initiate the development and transfer station as will be discussed in more detail hereinafter. It is noted that in lieu of cathode ray tube 11 other means may be substituted as a signal trans ducer means. One substitute might be a plurality of electrodes over which a record medium is passed. A suitable code system for driving input circuits 10 is described in U. S. Pat. No. 2,736,770 to McNaney. Cathode ray tube 11 may employ either electromagnetic or electrostatic deflection and is of the conventional type except that it is provided at one end with a fiber optic face plate or target screen 12 which is substantially flat so as to accommodate record web or belt 16. Fiber optic face plate 12 prevents light dispersion which would occur if the tube target screen were merely a glass face plate. Fiber optic face plate 12 through which the light image is transmitted is made of a bundle of glass fibers extending in a direction parallel to the axis of the cathode ray tube. The record web 16 is pressed against the face of cathode ray tube 11 by a plurality of rollers l, 2, and 6. Where the record web 16 is a photoconductor it would have a conductive backing of a flexible conductor such as aluminum and may be given an initial charge by electrode 18 which is connected to a source of high potential (not shown). A photoconductor is a non-conductor of electricity in the dark, but becomes conductive when exposed to light. After the belt or record web 16 has been exposed by high intensity light beam of the cathode ray tube 11, the image formed thereon is developed at process station 19 in accordance with well-known electrophotographic principles as described by Carlson in U. S. Pat. No. 2,221,776.
In operation, the beam starts in the position adjacent roller 1. As the beam writes lines 1, 2, 3, etc. and progresses toward the right, roller 1 moves with it. As viewed in FIG. 1 a line of characters is written when the beam sweeps in a plane into the page or in a plane substantially parallel to the axis of roller 1 and a page or character is written as the beam sweeps from left to right. Roller 1 as well as rollers 2 and 6 are of sufficient diameter and made of a material such as foam rubber having sufficient resiliency so as to apply firm contact to belt 16 with the face of cathode ray tube 11. The record web or-belt 16 does not move across the face of the cathode ray tube 11 but rather a different portion of the record medium is pressed against the face of the tube in synchronism with the sweep of the tube beam. The rotation of the rollers 1, 2, and 6 is counterclockwise, while moving from left to right across the face of the CRT 11. Rollers l, 2 and 6 have a resilient or deformable surface and thus when they are pressed against the face of CRT 11 a flat surface is formed on web 16 which presents a relatively large area for exposure of the record to the light of CRT 11. Also, the frictional forces of the record web 16, the rollers and the tension on record web 16 applied by drive rollers 4 and 5 insure that record web 16 is stationary during recording time.
When roller 1 moves to the position of roller 2, time has elapsed and the following action has taken place in synchronism with the movement of roller 1:
1. Roller 2 moves to the position previously occupied by roller 6.
2. Roller 3 moves down to a position below CRT 11 face to provide belt material or slack between rollers 1 and 6 and then moves up above CRT 11 face. Alternately, a vacuum column could provide the same motion as roller 3.
3. Roller 6 moves into the position previously occupied by roller 1.
4. Processing station 19 transfers images or develops thin transfer image to paper, cards, etc. from belt 16.
5. Belt 16 driven by rollers 4 and 5 moves away from the processing station, asynchronously if necessary, when transfer is complete.
It is understood from FIG. 1 that rollers l, 2 and 6 are mounted upon suitable support means such as a pair of parallel guide rails and guided by a motor 56 from left to right. In this configuration sufficient clearance is provided for roller 3 so that it may pass through the guide rails to produce slack in record web 16 at the proper time. These rollers rotate in a counterclockwise direction about their shafts and in so doing press an incrementing portion of belt 16 against the face of the CRT 11 in synchronism with the electron beam. U. 8. Pat. No. 3,446,554 to Hitchcock et al. describes a similar web advance system employing a bicycle chain drive in which the paper web is moved across a platen by presenting discrete areas of the paper to be scanned by an optical device. Upon reaching the right hand position the loop or slack formerly made by roller 3 is moved to the left hand position of cathode ray tube 1 l by the roller next in line to start pressing the belt against the face of CRT 11. During the time when the electron beam is blanked out development and transfer of the previously recorded information is accomplished at the processing station. Alternately, development and transfer of the recorded image may take place during the following sweep of the electron beam. In this case, development and transfer is always one time period behind the writing period. Rollers 4 and 5 drive belt 16 downward past the processing station so that the information thereon can be transferred and a new writing surface presented to the face of CRT 11. At the same time, roller 3 now forms a new loop in belt 16 and the action is then recycled. The drive means for receiving belt 31 is sent a driving signal from the control circuits so that transfer is made simultaneously with the movement of belt 16 by rollers 4 and 5.
When the beam of the cathode ray tube progresses from the left to point B the end of the page occurs. The beam in broken outline at point A shows the past position of the beam. At this time roller 1 for example, can begin moving to the right. When roller 2 starts moving to the position formerly occupied by roller 6, rollers 4 and 5 move so as to place the belt into proper position for image transfer. As noted above, only that part of belt 16 from roller 1 on moves since part of the belt is always in contact with the face of the cathode ray tube. As a result, no time is lost waiting for the belt to move in full page stops between pages since the action takes place during writing.
Referring now to FIG. 2, there is shown the details of the processing station. A portion of belt 16 is initially charged by electrode 18. Then the charged portion of the belt 16 is exposed in imagewise configuration by the light beam of cathode ray tube 11 as the light beam moves from left to right. The belt 16 is then passed over receptacle 20 where properly charged electroscopic powdered toner 22 is deposited on the latent image areas of the belt by paddle wheel 21. The belt then passes between a grounded V backing plate 25 and transfer electrode 26 where the powder images are transferred to a receiving web 31. Receiving web 31 is held in position against backing plate 25 by guide rollers 23 and 24 and is fed from supply reel 27 to takeup reel 28. The transferred images are next fixed to receiving web 31 by fuser 29. Belt 16 is cleaned of toner 22 by brush and the above cycle is repeated.
The foregoing description has been predicated on the assumption that belt 16 is comprised of a dielectric surface which is capable of holding an initial electrostatic charge and which is discharged in imagewise configuration upon exposure to the light beam of cathode ray tube 11. It will occur to those skilled in the art that other sensitized belts may be employed.
FIG. 3 illustrates another embodiment of the record ing apparatus wherein recording or printing is undertaken in a vacuum 40. In this embodiment a web 36 is fed from supply reel 34 to take-up reel 35. When the fiber optic face plate 12 is removed from CRT 11 and the system is placed in a vacuum the microprinting mode is improved. In this mode, processing at 39 may then be performed outside the vacuum. However, where belt 36 is a photoconductor and is the permanent record, processing may then be performed in the vacuum. Processing the photoconductor in this manner results in an improvement in that higher resolu' tion is possible because the electron beam and energy is increased by at least times. Alternately, the configuration of FIG. 3 may ,be operated in a positive vacuum or air.
Rollers 32, 33, 37 and 38 as well as electrode 41 perform the same function as described in FIGS. 1 and 2. Moreover, the operation of FIG. 3 is substantially the same as described with regard to FIGS. 1 and 2. The present invention is suitably unique in that printing can be asynchronous as is necessary in computer operation. For example, high speed can be maintained since mechanical motion as such is not a function that prevents beam writing. The fiber optic face plate transmits sufficient energy to allow the belt to be made of for example selenium, print 10,000 lines per minute and allow in excess of several hundred bits (CRT light spots) per character.
Where it is desired to record in the micro-image mode fiber optics having a small diameter and a small CRT are used in lieu of the larger diameter fiber optics and large CRT utilized for the full size imaging mode. For the intermediate size imaging mode fiber optics and a CRT between the above are employed.
It will be apparent to those skilled in the art that the present invention may be used generally in the field of recording and is -not limited to the embodiments described. Also, other variations, modifications and adaptations of the present invention will be apparent to those skilled in the art, and such as come within the spiritand scope of the appended claims are considered to be embraced by the present invention.
What is claimed is:
l. A high speed printing apparatus capable of page incrementing at micro, intermediate and full size comprlsingz a cathode ray tube having a fiber optic target face;
drive means adapted to move across the face of said cathode ray tube in synchronism with the crosswise movement of the electron beam of said cathode ray tube, and
a record medium responsive to the light emanating from said cathode ray tube overlaying said drive means, said drive means further adapted to contact discrete elements of each page portion of said record medium against said fiber optic face in synchronism with said electron beam as said drive means traverses said face such that during each traverse the contacting surfaces of said record medium are substantially stationary with respect to said fiber optic face, whereby images formed by said beam are recorded on said record medium.
2. The printing apparatus as defined in claim 1 wherein said drive means comprises a plurality of rotatable means, each of which sequentially traverse said fiber optic face in a common plane parallel to said face.
3. The printing apparatus as defined in claim 2 wherein is included means for producing slack in said record medium between said rotatable means positioned in said common plane.
4. The printing apparatus as defined in claim 3 wherein the depth of slack provides a length of said recording medium between said rotatable means substantially equal to two page widths whereby full size page incrementing may be provided with substantially no incrementing time lapse.
5. A high speed recording apparatus comprising:
a cathode ray tube,
means for driving said cathode ray tube in a synchronous or asynchronous mode,
a fiber optic plate connectible to the target screen of said cathode ray tube and adapted to concentrate the light beam emanating from said cathode ray tube,
a plurality of roller means adapted to move sequentially across said fiber optic plate in synchronism with the crosswise movement of said light beam and in response to signals from said cathode ray tube driving means, and
a light sensitive recording means formed into a web and disposed between said fiber optic plate and said roller means for recording images formed by said light beam thereon,
said recording means being carried by said roller means such that discrete elements of each page portion of said recording means are sequentially positioned adjacent said plate in synchronism with the crosswise movement of said light beam for recording images formed on said recording means without any incrementing time lapse.
6. The recording apparatus as defined in claim 5 wherein is included means for producing slack in said record medium between said roller means.
7. The recording apparatus as defined in claim 6 wherein the depth of slack provides a length of said recording medium between said roller means substan tially equal to two page widths.
8. The apparatus of claim 5 wherein said recording means is made of a photoconductive material and wherein is included means for placing an electrostatic charge on said recording means.
9. The apparatus of claim 8 including means for developing said formed images resulting from the exposure of said charged recording means to the light beam of said cathode ray tube.
10. The apparatus of claim 9 including means for transferring the developed images on said recording means to a permanent record means.
1 1. A high speed recording apparatus comprising:
signal transducer means for producing a translatable energy beam,
a record medium responsive to said energy beam,
means for sequentially placing discrete elements of each page portion of said record medium against said signal transducer means in synchronism with the crosswise movement of said energy beam to generate a latent image on said record medium with substantially no transverse movement between the exposed elements of said record medium and said signal transducer means during the exposure time of said elements, and
means for developing said latent images.
12. The high speed recording apparatus of claim 11 6 wherein said signal transducer means comprises a cathode ray tube.
13. The high speed recording apparatus of claim 11 wherein said placing means'comprises a plurality of rollers which advance in sequence loop portions of said record medium over the surface of said signal transducer means.
14. The high speed recording apparatus of claim 11 including means for transferring said developed images to a permanent surface.
15. The high speed recording apparatus of claim 14 including means for developing said record medium in a vacuum.
16. A high speed recording apparatus capable of page incrementing at micro, intermediate and full size for processing data from a high speed data source comprising:
a cathode ray tube capable of converting electrical signal input intelligence into image characters,
a photosensitive record medium,
drive means for sequentially contacting discrete elements of each page portion of said record medium against the face of said cathode ray tube in synchronism with the crosswise beam movement thereof to generate a full page latent electrostatic image on said record medium without crosswise movement parallel to the face of said cathode ray tube by said record medium,
means for developing said latent image, and
means for transferring said developed image to a permanent surface.
17. The apparatus of claim 16 including a fiber optic plate attached to the face of said cathode ray tube.
18. A high speed imaging apparatus in which data from a readout source is synchronously or asynchronously recorded on a record medium comprismg:
a cathode ray tube suitably connected to a power source and an input data and timing source, said cathode ray tube having a fiber optic face plate for concentrating the light beam emitted by said cathode ray tube;
a plurality of roller means each responsive to said timing source and adapted to move in sequence across said fiber optic face plate in synchronism with the beam sweep of said cathode ray tube,
a record medium disposed between said roller means and said fiber optic face plate,
means for placing an electrostatic charge on said record medium,
said roller means presenting an incremental portion of said charged record medium to imagewise exposure from said cathode ray tube,
means for maintaining a loop in said recording means and for maintaining the tautness of said record medium about said roller means,
means for developing the recorded data on said record medium, and
means for transferring said recorded data to a permanent surface.
19. A method of creating latent images on a record medium comprising:
placing a fiber optic plate on the face of a cathode ray tube,
forming a web of record material to be advanced across said fiber optic face of said cathode ray tube into a loop said web being made of material responsive to the light beam from said cathode ray tube,
advancing said web across said fiber optic plate so that a discrete portion of said web is pressed thereupon in synchronism with the sweep of the tube. I
20. The method of claim 19 including developing said created images by applying electroscopic toner particles thereto.
21. The method of claim 20 including developing said formed images on said record medium in a vacuum.
22. The method of claim 21 including developing said web asynchronously in accordance with the timing of the advancing of said web.
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|Citing Patent||Filing date||Publication date||Applicant||Title|
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|U.S. Classification||347/122, 358/300, 355/72|
|International Classification||G03G15/00, G03G15/32, G03B39/00|
|Cooperative Classification||G03B39/00, G03G15/328|
|European Classification||G03G15/32L1, G03B39/00|