CA1095971A

CA1095971A - Electronic typewriter using a solid state display to print

Info

Publication number: CA1095971A
Application number: CA296,269A
Authority: CA
Inventors: Robert W. Lester; Robert Hotto
Original assignee: STATIC SYSTEMS CORP
Current assignee: STATIC SYSTEMS CORP
Priority date: 1977-02-03
Filing date: 1978-02-01
Publication date: 1981-02-17
Also published as: GB1601097A; US4110794A

Abstract

ABSTRACT OF THE DISCLOSURE

A word processing system for displacing and repro-ducing a plurality of alphanumeric characters on a solid state display and capable of printing from that display con-sisting of a housing containing an electronic keyboard with indicia markings in the keys. There is provided at least one solid state display device disposed adjacent to the housing and having a multitude of segments for reproducing the indi-cia identified in the keyboard. A logic means is connected to the keyboard upon the depression of one or more keys to find out the identity of the keys depressed. A solid state memory is also connected to the logic means and contains coded infor mation concerning the keyboard indicia so that a character can be generated and reproduced on the solid state display responsive to the keyed indicia. There is also provided a data storage means for sequentially recording each of the keyed indicia responses provided by the keyboard and a means for printing the indicia displayed on the solid state screen.
A plurality of pages of information can be stored in the sys-tem and sequentially reproduced by the printer from the electronic display.

Description

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This lnvention relates to a llquid crystal word processing apparatu 5 .
More specifically, this lnventlon relates to ~
liquid crystal word processing apparatus having a keyboard and a display means consisting of one or more liquld crystal panels ~or reproducin~ the indicia created by the keyboard and permltting the indic~a to be reproduced onto paper a~ter a typewritten page has been completed.
Word processing machines, that is typewrlters having stored memories ~irst became available to the public during the middle 1960's. IBM Corporation developed the MTST model having a single or dual tape drive which was capable of receiving programmed information from a type-writer and allowing corrections to be made to the program be~ore the final copy was typed. A number of other manufacturers such as Remington, Redactrcn, S~bin as well as IBM also began produci~g magnetic card typ~writers having single and dual card capabllity. The typed lnformation was stored on one or more magnetlc cards and could be recalled by lnserting the card into a card reader at any time.
Suitable corrections could be made to the text o~ the card so that the machines removed the necessity of expensive proof reading of the final materlal once minor corrections were made to the original copy. More sophlstocated word processln~ machines have also been developed using a full page CR~ (cathode ray tube) display such as the Vydec apparatus. This allows a full video display o~ the typed informa-tlon before it is transcribed on paper.

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There is also a Xerox 1200 ~odel which consists of a binary information fed or serially fed photocopying machin2 which, however, employs many moving parts, including a cha-racter-generating arum moving at high speed insiae the sel~n-inum reproduction drum. "rhe character drum works in cosnbina-tion with a photo-optical generator for reproducing the images on the reverse side of the seleninum drum, so that they can be printed after suitable dusting and heat. The images produced by this Xerox method are blurred and thi differs from the present invention, which does not have any moving parts or any noise since it is entirely ~lectronic in its character generation.
Almost all of the above machines require the use of a mechanical printing device for transcribing the recorded information on to a printed pageO Some of the word process-ing devices use a heavy duty IBM selectric typewriter, where-as others use a high speed printer capable of printing ap-proximately 500 words per minute. Newer printers are becom-ing available using an ink spray deposit method in an attempt~
to improve the speed of the printout. Where a large number of pages have to be reproduced from stored information, the operator of the word processing machine remains idle for lon~
periods of time until the mechanical printing device can complete the transfer of the information from a memory disc or tape to the prin-ted page.
The conventional word processing machine also suffer frorn the disadvantage that the mechanical printers are subjecl: to breakdown and require frequent repairs or ~O~S~

adjustments during a heavy duty operation~ The mechanical printing portion of the word processing machines also repre-sents a substantial cost of the word processor, so that the price to purchasé soma of the conventional worcl processors run between $10,000 - $18,000. Moreover, the cost of type-writer ribbons for the mechanical processor~ r~ms about $200 to $500 per year, an expense that is eliminated by the pre-sent invention.

Accordingly, the present invention p~ovides an lo improved word processing apparatus which uses electronic circuitry and a solid state display for transferring the stored information to the printed pags. A conventional photocopy device can be coupled to the solid state display, such as a liquid crystal display to quickly reproduce the information that is written on the display after the informa-tion is taken from the stored memory.
However, the conventional photocopy device such as a Xerox machine using untreated paper has a disadvantag~ in that there are many mechanical moving parts wit~in the machin~.
It is possible to eliminate the above disadYantage by using a photosensitive paper that develops upon the application of heat, such as Thermo ax paper used by the 3M manual copier.
Thus! the inventive word processing system can be maae com-pletely solid state without any moving parts when reproduci~g typewritten copy.

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One Or the problems o~ liquid crystal dlsplay~
is the segmentation between adJacent areas thus causing writ~en indicia to be broken into a plurality of individual lines to form a number or letter. This is clearly lllus-trated on a llquid crystal watch display pres~ntly available.
In order to overcome this disadvantage, the present inven-~ion provides a plurality o~ superimposed liquid crystal display panels in ~hich the information lS simultaneously ~ri~ten. The adJacent LC panels are slightly o~fset to cover over the segmenl;ation or the upper mosk LC panel so that all signs Or interruptions or segmentated lines will disappear and the letters T~ill be perrectly ~ormed. Since the LC display is an elec~ronic device, ~he s~ored informa-tion can be almost lnstantly reproduced fro~n t;he stored memory. Moreover, both the slze Or the indicia and the style o~ the type can also be changed since the apparatus is no~ dependent upon mechanlcal printing means for repro-ducing the letters. Once a completed letter has been ~ritten on the LC display~ it can be quickly reproduced one or a number o~ times by a conventional photocopy machine Sucll as a Xerox appara~us. Thus, the original letter can be copied and simultaneously reproduced ~or as many copies as needed, ~ t is there~ore an ob~ect according to the present invention to provide a liquid crystal word processing apparatus which is capable o~ reproduclng stored in~ormation at a rate raster than conventlonal devices.

It is another obJect according to the present invention to provide a liqulcl crystal word processlng apparatus which is ~lmple in design, easy to manufacture and reliable ln operation. Other obJects and features of the present invention w~11 become apparent ~rom the ~ollowing detailed descrlption considered in connection with accompanying drawings which disclose the embodiments of the invention. It is to be understood, however, that the drawings are designed ror the purpose of illustration only and not as a definition o~ the limits of the Lnvention.
In the drawings wherein similar reference characters denote similar elements throughout the several views:
Fig. 1 is a perspective view showin~ one or more LC word processing stations lnterconnected ko a plurality of display or copying devices according to the invention;
Fig. 2 is an electrlcal block diagram of the apparatus of Fig. l;
Fig. 3 is a further electrical block diagram in detail of a portlon of the apparatus of Fig. 2;
Fig. 4 is a schematic diagram of the drlving circuit for a typical liquid display panel;
Fig. 5 is a cross sectional view 3howing several overlapping LC panels;
Figo 6 is a detailed view showing the LC segments to make up letters or numbers from two dlfferent panels;
Fig. 7 is a detailed view showing ad,Jacent Overlapping LC panels with reproduced lndlcla;

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Fig. 8 illustrates a particular indicia taken frorn two differen-t LC panels;
Fig. 9 illustrates one typical ]ine of indicia of an LC panel;
Fig. 10 is a detail view showing a composi-te of a plurality LC overlapping panels with all segmentation removed;
Figs. 11-1~ illustra-te clifferent LC panels before they are overlapped showing different arrangments for re-moving segmentation.
Referring to Fig. 1 there is shown a plurality of LCD word processing devices 10, 35 and 36 having LCD screens 11 and keyboards 12. The devicesare connected via electrical lines 13, 34 and 33 to an interface circuit 14 which is Capable of connecting them to a plurality of different ou-t-puts. One output is connected via line 15 to a facsimile transmitter and receiver 16 having an on-off switch 19 and a pushbutton dialing system 17. There is also provided a cradl~

receptacle 18 so that a telephone can be used to transmit the information serially to a facsimile receiver at a remote location, or receive information from another station.
Another output of interface 14 comprises a LCD
screen 21 connected via line 20, which can be placed on the ~lass screen 26 oE a photographic or a photo engraving device ~2. Control buttons 25 and 24 will operate the duplicator So that the indicia produced on screen 21 will be reproduced on photographic print paper ~3.

Another output of inteL~ce 14 is connected via line 28 -to an LCD screen 29 moun-~ed on a conventional pho-to~
copy machine 27 which as a Xerox machine so that copies can be received from output 30. It is obvious that a plurality of copies of the same text can be made depending upon the setting of the photocopy machineO
A further output of interface 14 is connected via line 31 -to a remote LCD screen 32 for observation.
Referring to Fig. 2 there is shown an electrica]
block diagram of the circuit of Fig. 1. In LCD processor 10, keyboard 12 feeds a microprocessor circuit 37 which has its output connected to a multiplex unit 44. The output of the multiplex unit is connected -to a driver circuit 38 which is then connected to liquia crystal screen 11. The screen is also connected to interface circui-t 14 which has its ou-t-put connected to a facsimile transmitter and received 16~ or the photoengraver or copiers 22 and 27 respectively, or re-mote screen 32.

In operation, when one oE the indicia keys of key-board 12 is depressed, microprocessor 37 scans the keyboard for the key depression. The microprocessor decodes the key to find out which key has been operated and then assesses its memory to generate the correct character on the display screen. The LC screen is turned on for a period of time and the other printing units 22, 27 and 32 can be attachecl to th~
same screen. Interface circuitry 14 takes care of the prob-lem when two printing units 22 and 27 are activated by de-pressing keys simultaneously, the same fraction of a second, if that occurs.

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There is also provided a "print" key on the key-board. When the print key is depressed, the microprocessor will send the code to the logic circuitry on the image screen. This code in-terrogates to see if the image screen is in use. The image screen logic then sends a code to the pro-cessor about its sta-tus. If the screen i5 no-t in use, the microprocessor then sends a code to multiplex unit 44 to be ready to receive data. This process is called "hand shaking"
and takes place where there is a status and ready communica-tion between the proceSsor and the interface Circuitry. The "hand shaking" takes place in order to prevent interference if other terminal units such as 35 and 36 are tied to the same image screens. It is also possible to remove screen ll from housing ll with a trailing wire or a built-in power holding circuit to freeze the indicia on the LC screen so that the screen can be taken to a remote copier for printing.
Fig. 3 shows a more complex electrical diagram which also includes the memory storage units for -the LCD word pro-cessor. Keyboard 12 in this case is connected to a peripheral interface adapter PIA 40 which controls the LCD display ll.
PIA 40 is then connectea through the main trunk of the cir-cuitry to a microprocessor 37, a random access memory RAM 41 and a read-only memory ROM 42. Another pair of PIA circuits 46 and 47 are interconnected to solid state memory circuits 45 so that the keyboard information can be stored on memory devices such as PROMS, CCD's or MsMs.
The left side of the circuit in Fig. 3 shows con-nections to PIAs 43 and 143 which feed multiplex decode and drive circuits 38 and 138. PIAs 43 and 143 serve as the in-terface adapters from microprocessor 37 to the decode and drive circuitry 38. These terminate in LCD screens 21, 29 ; ,-., : : : , ~s~

or 32 depending on the connec-tion2 The apparatus of E'ig. 3, is set up to operate -two overlapping LCD screens, each being driven by its separate clecode or drive clreuit 38 or 138.
The screens have their indisia ~ htly offset with respect to each other so that the segmentation which is inherent in LCdisplays between individually activated areas can b~
eliminated. The ASCIA 16 is in the facsimile output as shown in Figs. 1 and 2. This allows the information stored in the microprocessor to be fed out serially through a tele-phone line to a facsimile receiver or modem 44. It can alsoreeeive information from a remote source and display i-t for printing.
Random access memory device R~l 41 is a read-write memory wherein the binary di~its within the memory can be ehanged as well as read by the microproeessor computer.
RP~IS are manufactured by Intel Corporation (2102) or Na-tional Semiconductor Corporation (MM2101-1 or MM2101-2). Read-only memory ROM 42 is a fixed semieonductor memory where it is not possible to ehange the state of the binary digits in the memory. The memory is put in when the ROM is manuEactured so that it can be read but not ehanged~ The ROM stores the codes for eaeh keyboard indicia that is seanned by the mieroprocesW
sor when a key is depressed~
Microprocessor unit 37 is an indefinite variety of lo~ic deviees implanted in an integrated circuit. This in-tegrated eireuit is composed of a chip of processed silieon sg7~

wafer and is usually mounted in a dual inline package (DIP).
The microprocessor can be consiclered a digital computer due to its similarity of instruction sets, addressing codes and execution speeds. Available microprocessor units are manu-factured by Intel Corporation (8080) and National Semicon-ductor Corporation (SC/MP8080, and IMP/16). Peripheral in-terface adapters (PIAs) are also commercially available circuits for interconnecting peripheral device units and microprocessors.
Fig. 4 is a combination of an electrical block diagram schematic diagram showing how a typical multisegment-ed liquid crystal display 60 is driven.
The multiplexing of a liquid crystal is performed in many ways. A drive voltage of six volts can be providecl to drive the liquid crystal to produce an opaque area on the screen. There are a number of different ways to multiplex the segment displays or dots. One of the preferred ways is by placing the decoded circuitry on the screen itself.
There are other technologies that can be used such as PLTZ
and electrochromic displays. All displays such as LCD mus,t be constantly refreshed in order to retain the image. The memory time is 200 milliseconds on some of the crystals, but can vary. There are various ways in multiplexing a PLTZ
crystal on the electrode of a conductive photoresistglass, which usually uses the "NESA" glass made by Pittsburgh Plate Glass. It is a conductive glass and it has a photoresist pattern on it that is etched by photoresistant process, -- 10 ~

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The crystal can be excited ~y pu-t-t.ing the volta~e on it. The driving voltage for liquid crystal at this present time is about six volts. When the crystal is strobed, the individual arrays are connected to ground, either in the XY pattern, or in a s-trobing technique, one line at a time. The decocler chip is placed on the screen itself and inEormation is sent serially to the decoded chip so that this decoded chip will access the individual dots.
This more efficient way has less connections -to the glass.
In Fig. 4, the decoded information comes straight from the microprocessor and the decoded information can be multiplexed by a decoder and driver chip. The processor contains input lines AO, Al, A2, A3, A4, A5r etc. depending on how many dots that are being driven, Terminal CB2 is connected to a drive circuit for turning on the copy machine, The microprocessor will have direct control over the turning "on" and "off" of the copy machine and controlling for ex-ample, the stepper, paper movement, etc. The heart of the control is the microprocessor~ The preferred circuit in-cludes the decoding and drive circuitry on the screen itself, This minimizes the amount of wires connected to screen 60.
Fig. 5 is a cross-sec-tional view through a typical liquid crystal display of the present invention showing a x housing 50 having three LC display panels 52, 53 and 54 which are covered by a photosensitlve paper sheet 55. Each oE the LC displays 52, 53 and 54 are driven by separate or multiplex and driver circuits so -that the identical indlcia/
alphanumeric inormation is displayed on each one. However, :

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the LC displays ~re offset w:ith respect ~o each o-ther b~
small amount and in one of three or four clirections, so tha~
the space between the LC segrnen-ts can be masked over and an uninterrupte~ continuous :indicia can be produced.
Fig. 6 illustrates a typical 15 segment display for either an ~-shaped figure or a rounded figure showing the segments involved. Fig. 7 shows an aliynment of four LC units 58 which are superimposed over one another so tha-t the segmentation can be eliminated. Fig. 8 shows different ways of making up the number 2 so that when the two indicia 59 overlap each other, there is no showing of any segmenta-tion.
Fig. 9 shows one LC strip which is used for making a line of indicia through multiplexing, and is composed of a plurality of small closely spaced dot matrix.
Fig. 10 is a detailed view of a completely closed LCD display section formed by the dot ma-trix of Figs. 11, 12, 13 and 14 superimposed. The dots of one layer overlap the dots of succeeding layers to form a solid letter from an open matrix.
The resolution on the liquid crystal display can be 20 thousandths of an inch square and so that extra plates may not be needed.
In -the present invention, it has been found tha~
iE the se~lentation is not objectionable, only a single LCD
screen is required since it has been found that the resolu-tion of most photocopy processors such as a Xerox processor will not be able to pick up the spaces between the LC seg-~7~

ments. This is because the black reprocluction will sligh-tly blur across the gap between the segments to form perfec-t letters and numbers.
Where fine detail is required, two, three or four overlapping screens may be desirable to elimi.nate the spaces between the LC segments. With a tot.al of four screens overlapping, it is possible to completely elimina-te spacing between the LC segments when a high contrast print is made from a photocopy machine.

As a word processing apparatus, the user will type a complete page of written tex-t using keyboard 12 so that it will appear on LCD display 11 on the console. At the same time, the memory circuit which may consist o~ a solid state memory 45, will also record the information on the page. Suitable corrections can be made on the display indicia and then the operator can press a "print" button which will cause the display to appear on the remote LC
screen or screens 21 or 29 almost instantaneously and a photocopy picture can be -taken of -the LC display. Since there is no mechanical printer involved in forming the let-ters, the information stored on the solid state memory can be rapidly read onto the I,C display and quickly printed.
Another advantage of the present invention is that the size and style of type can be changed. For example, if a short business letter is to be reproduced on a company letterhead using a photocopy process, the lettering can be increased in size and adjusted to the margins In ROM 42 ~S~7~

can be stored binary information relating to GothiC type style, Roman type style as well as type size information so that the aepressing of a particular key bearing the type style on the keyboard will automatically change the readout display to that type style.
The memory circuit 45 will also allow one to store a large number of pages of writ-ten infoxmation such as a multipage report so that it can be recalled at any time and rapidly reprinted sequentially.

It is also possible for the operator to make multiple copies of each page in the memory and collate them on the copying machine by depressing the appropriate keyboard button.
While only a few embodiments o the present inven-tion have been shown and described, it will be obvious to those skilled in the art that many changes and modifications may be made thereunto without departing from the spirit and scope of the invention.

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A word processing system for displaying and re-producing alphanumeric characters comprising:
a housing including an electronic keyboard with keys representing individual alphanumeric characters;
at least one solid state reflective display for reproducing the characters identified on the keyboard;
logic means connected to said keyboard and solid state reflective display for scanning said keyboard upon the depression of one or more keys;
solid state memory means having stored coded char-acter information and coupled to said logic means for sequenc-ing said logic means for each of the keyed characters depress-ed and for generating a displayed character on said solid state display screen responsive to the character keyed; and print means coupled to said solid state display for reprinting the characters appearing on said display.

2. The word processing system as recited in claim 1 wherein said at least one solid state display comprises a liquid crystal display.

3. The word processing system as recited in claim 2 additionally comprising recorded memory means coupled to said logic means for sequentially storing the coded character in-formation produced by said keyboard.

4. The word processing system as recited in claim wherein said liquid crystal display comprises at least one liquid crystal screen, a multiplex decoder and driver circuit having its output coupled to said screen and its input coupled to said logic means for sequentially displaying the alphanumer-ic characters on the screen.

5. The word processing system as recited in claim 4 wherein said print means comprises a photocopy machine.

6. The word processing system as recited in claim wherein said at least one liquid crystal display is coupled to said housing adjacent said electronic keyboard and com-promising a second liquid crystal display coupled to said at least one liquid crystal display and in optical contact with said photocopy machine.

7. The word processing system as recited in claim 6 wherein said liquid crystal displays comprise at least two liquid crystal screens superimposed with respect to each other wherein said screens have an identical dot matrix layout with respect to each other, wherein one of said dot matrix layouts is slightly offset with respect to the other in an amount suf-ficient to fill in the space between the matrix dots.

8. The word processing system as recited in claim 1 wherein said logic means comprises a microprocessor and said solid state memory means comprises a ROM.

9. The word processing system as recited in claim 3 wherein said recorded memory means comprises a ROM.

10. The word processing system as recited in claim 2 wherein said at least one liquid crystal display comprises four display screens superimposed with respect to each other and disposed in close adjacent proximity, said screens having identical clot matrix layout wherein each of the dot matrix layouts of adjacent screens are offset in one of four direc-tions in an amount sufficient to fill in the space of adjacent dot matrix segments so that a character generated simultaneous-ly on all four screens will be continuous without segmentation.

11. The word processing system as recited in claim 2 wherein said at least one solid state display comprises an electrochromex screen.

12. The word processing system as recited in claim 2 wherein said at least one solid state display comprises a PLTZ screen.

13. The word processing system as recited in claim 1 wherein said print means comprises a photoengraver having self-developing film.

14. The word processing system as recited in claim 3 wherein said print means comprises a photocopy machine.

15. The word processing system as recited in claim 1 additionally comprising a facsimile transmitter and receiver coupled to said logic means for sequentially transmitting and receiving alphanumeric character information to and from a remote source for display on said solid state display.

16. The word processing system as recited in claim 2 wherein said at least one liquid crystal display comprises a remote liquid crystal screen for displaying generated char-acter information at a remote location.

17. The word processing system as recited in claim 14 wherein said keyboard additionally comprises print key means coupled to said photocopy machine for sequentially re-producing the alphanumeric characters reproduced on said liq-uid crystal display.

18. The word processing system as recited in claim 17 wherein said print key means is coupled to said recorded memory means, for reproducing a series of pages of stored in-formation on said photocopy machine in response to said print key.