Electronic typewriter using a solid state display to print

A word processing system for displaying and reproducing a plurality of alphanumeric characters on a solid state display and capable of printing from that display consisting of a housing containing an electronic keyboard with indicia markings on 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 indicia identified on the keyboard. A logic means is connected to the keyboard and the solid state display, and scans 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 information 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 system and sequentially reproduced by the printer from the electronic display.

This invention relates to a liquid crystal word processing apparatus. 
More specifically, this invention relates to a liquid crystal word 
processing apparatus having a keyboard and a display means consisting of 
one or more liquid crystal panels for reproducing the indicia created by 
the keyboard and permitting the indicia to be reproduced onto paper after 
a typewritten page has been completed. 
Word processing machines, that is typewriters having stored memories first 
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 typewriter and allowing 
corrections to be made to the program before the final copy was typed. A 
number of other manufacturers such as Remington, Redactron, Sabin as well 
as IBM also began producing magnetic card typewriters having single and 
dual card capability. The typed information was stored on one or more 
magnetic cards and could be recalled by inserting the card into a card 
reader at any time. Suitable corrections could be made to the text of the 
card so that the machines removed the necessity of expensive proof reading 
of the final material once minor corrections were made to the original 
copy. More sophistocated word processing machines have also been developed 
using a full page CRT (cathode ray tube) display such as the Vydec 
apparatus. This allows a full video display of the typed information 
before it is transcribed on paper. 
There is also a Xerox 1200 Model which consists of a binary information fed 
or serially fed photocopying machine which, however, employs many moving 
parts, including a character-generating drum moving at high speed inside 
the seleninum reproduction drum. The character drum works in combination 
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 
this differs from the present invention, which does not have any moving 
parts or any noise since it is entirely electronic 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 page. 
Some of the word processing devices use a heavy duty IBM selectric 
typewriter, whereas others use a high speed printer capable of printing 
approximately 500 words per minute. Newer printers are becoming 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 long periods of time until the mechanical printing device can 
complete the transfer of the information from a memory disc or tape to the 
printed page. 
The conventional word processing machines also suffer from the disadvantage 
that the mechanical printers are subject to breakdown and require frequent 
repairs or adjustments during a heavy duty operation. The mechanical 
printing portion of the word processing machines also represents a 
substantial cost of the word processor, so that the price to purchase some 
of the conventional word processors run between $10,000 - $18,000. 
Moreover, the cost of typewriter ribbons for the mechanical processors 
runs about $200 to $500 per year, an expense that is eliminated by the 
present invention. 
Accordingly, the present invention provides an improved word processing 
apparatus which uses electronic circuitry and a solid state display for 
transferring the stored information to the printed page. 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 information is taken from the stored 
memory. 
However, the conventional photocopy device such as a Xerox machine using 
untreated paper has a disadvantage in that there are many mechanical 
moving parts within the machine. It is possible to eliminate the above 
disadvantage by using a photosensitive paper that develops upon the 
application of heat, such as Thermofax paper used by the 3M manual copier. 
Thus, the inventive word processing system can be made completely solid 
state without any moving parts when reproducing typewritten copy. 
One of the problems of liquid crystal displays is the segmentation between 
adjacent areas thus causing written indicia to be broken into a plurality 
of individual lines to form a number or letter. This is clearly 
illustrated on a liquid crystal watch display presently available. In 
order to overcome this disadvantage, the present invention provides a 
plurality of superimposed liquid crystal display panels in which the 
information is simultaneously written. The adjacent LC panels are slightly 
offset to cover over the segmentation or the upper most LC panel so that 
all signs of interruptions or segmentated lines will disappear and the 
letters will be perfectly formed. Since the LC display is an electronic 
device, the stored information can be almost instantly reproduced from the 
stored memory. Moreover, both the size of the indicia and the style of the 
type can also be changed since the apparatus is not dependent upon 
mechanical printing means for reproducing the letters. Once a completed 
letter has been written on the LC display, it can be quickly reproduced 
one or a number of times by a conventional photocopy machine such as a 
Xerox apparatus. Thus, the original letter can be copied and 
simultaneously reproduced for as many copies as needed. 
It is therefore an object according to the present invention to provide a 
liquid crystal word processing apparatus which is capable of reproducing 
stored information at a rate faster than conventional devices. 
It is another object according to the present invention to provide a liquid 
crystal word processing apparatus which is simple in design, easy to 
manufacture and reliable in operation. Other objects and features of the 
present invention will become apparent from the following detailed 
description considered in connection with accompanying drawings which 
disclose the embodiments of the invention. It is to be understood, 
however, that the drawings are designed for the purpose of illustration 
only and not as a definition of the limits of the invention.

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 devices 
are connected via electrical lines 13, 34 and 33 to an interface circuit 
14 which is capable of connecting them to a plurality of different 
outputs. One output is connected via line 15 to a facsimile transmitter 
and receiver 16 having an on-off switch 19 and a pushbuttom dialing system 
17. There is also provided a cradle 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 glass screen 26 of a photographic or a 
photo engraving device 22. Control buttons 25 and 24 will operate the 
duplicator so that the indicia produced on screen 21 will be reproduced on 
photographic print paper 23. 
Another output of interface 14 is connected via line 28 to an LCD screen 29 
mounted on a conventional photocopy 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 machine. 
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 electrical 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 liquid crystal screen 11. The screen is also connected 
to interface circuit 14 which has its output connected to a facsimile 
transmitter and received 16, or the photoengraver or copiers 22 and 27 
respectively, or remote screen 32. 
In operation, when one of the indicia keys of keyboard 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 attached to the same screen. Interface 
circuitry 14 takes care of the problem when two printing units 22 and 27 
are activated by depressing keys simultaneously, the same fraction of a 
second, if that occurs. 
There is also provided a "print" key on the keyboard. When the print key is 
depressed, the microprocessor will send the code to the logic circuitry on 
the image screen. This code interrogates to see if the image screen is in 
use. The image screen logic then sends a code to the processor about its 
status. If the screen is not 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 
communication 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 11 from housing 11 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 processor. Keyboard 12 in this case 
is connected to a peripheral interface adapter PIA 40 which controls the 
LCD display 11. PIA 40 is then connected through the main trunk of the 
circuitry 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 MBMs. 
The left side of the circuit in FIG. 3 shows connections to PIAs 43 and 143 
which feed multiplex decode and drive circuits 38 and 138. PIAs 43 and 143 
serve as the interface adapters from microprocessor 37 to the decode and 
drive circuitry 38. These terminate in LCD screens 21, 29 or 32 depending 
on the connection. The apparatus of FIG. 3, is set up to operate two 
overlapping LCD screens, each being driven by its separate decode or drive 
circuit 38 or 138. The screens have their indicia slightly offset with 
respect to each other so that the segmentation which is inherent in 
LCdisplays between individually activated areas can be 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 telephone line to a facsimile receiver or modem 44. It can also 
receive information from a remote source and display it for printing. 
Random access memory device RAM 41 is a read-write memory wherein the 
binary digits within the memory can be changed as well as read by the 
microprocessor computer. RAMS are manufactured by Intel Corporation (2102) 
or National Semiconductor Corporation (MM2101-1 or MM2101-2). Read-only 
memory ROM 42 is a fixed semiconductor memory where it is not possible to 
change the state of the binary digits in the memory. The memory is put in 
when the ROM is manufactured so that it can be read but not changed. The 
ROM stores the codes for each keyboard indicia that is scanned by the 
microprocessor when a key is depressed. 
Microprocessor unit 37 is an indefinite variety of logic devices implanted 
in an integrated circuit. This integrated circuit is composed of a chip of 
processed silicon wafer and is usually mounted in a dual inline package 
(DIP). The microprocessor can be considered a digital computer due to its 
similarity of instruction sets, addressing codes and execution speeds. 
Available microprocessor units are manufactured by Intel Corporation 
(8080) and National Semiconductor Corporation (SC/MP8080, and IMP/16). 
Peripheral interface 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 multisegmented liquid crystal display 60 is driven. 
The multiplexing of a liquid crystal is performed in many ways. A drive 
voltage of 6 volts can be provided 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 electronic displays. All 
displays such as LCD must 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 photoresit glass, which usually used 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. 
The crystal can be excited by putting the voltage on it. The driving 
voltage for liquid crystal at this present time is about 6 volts. When the 
crystal is strobed, the individual arrays are connected to ground, either 
in the XY pattern, or in a strobing technique, one line at a time. The 
decoder chip is placed on the screen itself and information 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 A0, A1, A2, A3, A4, A5, 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 example, the stepper, paper movement, 
etc. The heart of the control is the microprocessor. The preferred circuit 
includes the decoding and drive circuitry on the screen itself. This 
minimizes the amount of wires connected to screen 60. 
FIG. 5 is a cross-sectional view through a typical liquid crystal display 
of the present invention showing a housing 50 having three LC display 
panels 52, 53 and 54 which are covered by a photosensitive paper sheet 55. 
Each of the LC displays 52, 53 and 54 are driven by separate multiplex and 
driver circuits so that the identical indicia or alphanumeric information 
is displayed on each one. However, the LC displays are offset with respect 
to each other by a small amount and in one of three or four directions, so 
that the space between the LC segments can be masked over and an 
uninterrupted continuous indicia can be produced. 
FIG. 6 illustrates a typical 15 segment display for either an X-shaped 
figure or a rounded figure showing the segments involved. FIG. 7 shows an 
alignment of four LC units 58 which are superimposed over one another so 
that 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 segmentation. 
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 matrix 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 that if the segmentation is not 
objectionable, only a single LCD screen is required since it has been 
found that the resolution of most photocopy processors such as a Xerox 
processor will not be able to pick up the spaces between the LC segments. 
This is because the black reproduction will slightly blur across the gap 
between the segments to form perfect letters and numbers. 
Where fine detail is required, two, three or four overlapping screens may 
be desirable to eliminate the spaces between the LC segments. With a total 
of four screens overlapping, it is possible to completely eliminate 
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 text 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 of 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 letters, the information stored 
on the solid state memory can be rapidly read onto the LC 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 
can be stored binary information relating to Gothic type style, Roman type 
style as well as type size information so that the depressing 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 written information 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 of the present invention 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.