U.S. patent number 3,824,604 [Application Number 05/297,011] was granted by the patent office on 1974-07-16 for alphanumeric printing system employing liquid crystal matrix.
Invention is credited to Edward I. Stein.
United States Patent |
3,824,604 |
Stein |
July 16, 1974 |
**Please see images for:
( Certificate of Correction ) ** |
ALPHANUMERIC PRINTING SYSTEM EMPLOYING LIQUID CRYSTAL MATRIX
Abstract
A completely solid state printing system having a keyboard or
computer input, a bit encoder or data translator, a matrix
switching system, a liquid crystal matrix to optically form the
characters to be printed, a fiber optics translator, and a
xerographic printing machine to reproduce the character impressions
received from the fiber optics translator.
Inventors: |
Stein; Edward I. (Skokie,
IL) |
Family
ID: |
23144488 |
Appl.
No.: |
05/297,011 |
Filed: |
October 12, 1972 |
Current U.S.
Class: |
396/549; 355/1;
355/40; 349/3; 348/804; 345/168; 345/50; 101/DIG.37; 348/790;
396/553; 347/136 |
Current CPC
Class: |
G02F
1/1313 (20130101); B41J 2/465 (20130101); Y10S
101/37 (20130101) |
Current International
Class: |
B41J
2/465 (20060101); B41J 2/435 (20060101); G02F
1/13 (20060101); B41b 013/00 (); B41b 015/00 ();
B41b 017/00 () |
Field of
Search: |
;355/40 ;95/4.5
;350/16LC |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Matthews; Samuel S.
Assistant Examiner: Wintercorn; Richard A.
Attorney, Agent or Firm: Strauch, Nolan, Neale, Nies &
Kurz
Claims
What is claimed and desired to be secured by Letters Patent is:
1. A solid state electro-optical printing system for composing and
printing an infinite variety of characters and/or designs
comprising memory bank output means for outputting bit data to be
translated and subsequently printed in preselected character and/or
design format, matrix bit encoding means fed from said memory bank
output means, matrix switching means operable by said bit encoding
means, non-mechanical electro-optical graphic character display
means for displaying said preselected character and/or design
format, activated periodically from said bit encoding means,
optical image transfer means associated in fixed, immovable
relationship with said graphic character display means, said
electro-optical display means functioning solely as a light shutter
with said optical image transfer means to form and convey by said
latter means said preselected character and/or design format, and
optical input printing means for printing images received from said
optical image transfer means.
2. The invention as recited in claim 1 wherein said electro-optical
graphic character display means comprise a plurality of graphic
character image blocks, each block comprising a plurality of
electrically actuated liquid crystals, each liquid crystal being
selectively activated from said bit encoding means.
3. The invention as recited in claim 2 wherein said electro-optical
graphic character display means comprise means for displaying
alphanumeric characters.
4. The invention as recited in claim 2 wherein each said liquid
crystal is a cholesteric nematic liquid crystal, substantially
optically clear in an undisturbed state, and substantially
optically opaque under influence of an electrical impulse passing
therethrough.
5. The invention as recited in claim 2 wherein each said liquid
crystal is a cholesteric nematic liquid crystal, substantially
optically opaque in an undisturbed state, and substantially
optically clear under influence of an electrical impulse passing
therethrough.
6. The invention as recited in claim 1 wherein said optical image
transfer means comprise a bundle of optical fibers.
7. The invention as recited in claim 1 wherein said optical input
printing means comprise a xerographic printer.
8. The invention as recited in claim 7 wherein said xerographic
printer means further comprise a web supply of paper.
9. The invention as recited in claim 1 wherein said electro-optical
graphic character display means comprise a circular liquid crystal
matrix, each liquid crystal therein being selectively activated
from said bit encoding means, optical signal transfer means from
said liquid crystal matrix, and graphic character display means
activated by said optical signal transfer means.
10. The invention as recited in claim 9 wherein said graphic
character display means comprise means for displaying alphanumeric
characters.
11. The invention as recited in claim 9 wherein each said liquid
crystal is a cholesteric nematic liquid crystal substantially
optically clear in an undisturbed state, and substantially
optically opaque under influence of an electrical impulse passing
therethrough.
12. The invention as recited in claim 9 wherein each said liquid
crystal is a cholesteric nematic liquid crystal substantially
optically opaque in an undisturbed state and substantially
optically clear under influence of an electrical signal passing
therethrough.
13. The invention as recited in claim 1 wherein said
electro-optical graphic character display means comprise a line
display capable of differential character spacing display of
alphanumeric characters.
14. The invention as recited in claim 1 wherein said
electro-optical graphic character display means comprise a multiple
line display capable of differential character spacing display of
alphanumeric characters.
15. The invention as recited in claim 1 wherein said
electro-optical character display means comprise a multiple line
display capable of displaying graphic designs.
Description
BACKGROUND OF THE INVENTION
A basic solid state printing system employing a memory bank output,
matrix encoding means alphanumeric character forming means, and a
printout means operable from the alphanumeric character forming
means is not a new concept. Multiple attempts have been made to
produce a satisfactory and highly reliable system. A major
difficulty in the art has been to completely minimize and even
eliminate all mechanical moving parts in such a system. Heretofore,
this has not been possible.
The general system under discussion is clearly disclosed in three
prior U.S. pats. Nos. 3,217,640 issued to Bradshaw; 3,354,817
issued to Sakurai et al. and 3,453,648, issued to Stegenga. In each
case, however, mechanics enter in along the the system imparting
unreliability of performance. An easily recognized example of this
is found in the disclosure of the U.S. pat. No. 2,632,386 to
Hyland, wherein a wire type print machine uses alphanumeric
character blocks as the actual print means, each block having 35
extensible print bits to form the individual character. If one or
more bits jam in high speed operation, which they invariably will,
then the entire printing system is imperfect.
In major contradistinction to prior art systems and processes, the
present invention calls for an optical character matrix system to
optically form the characters and convey the same to optical input
printing means, such as a xerographic machine.
SUMMARY OF THE INVENTION
It is the primary object of the invention to provide an
alphanumeric character printing system having a light-optical
character forming and conveying means to the printing means.
It is another object of the invention to provide such a printing
system with a liquid crystal matrix to form an individual,
light-optically readable character.
Yet another object of the invention is to provide such a printing
system with a liquid crystal matrix to form one or more lines of
light-optically read characters for differential character spacing
resulting in even line printout.
A further object of the invention is to provide such a printing
system with a two-stage alphanumeric character forming matrix,
using a circular easily formed etched surface electrode to
translate data into optically readable bits and a fiber optics
system to convey the readable bits to an alphanumeric character
display board.
A still further object of the invention is to provide such a
printing system with either a steady or intermittently actuated
light source to convey the formed alphanumeric character from the
character display to the optical input printing means.
Further novel features and other objects of this invention will
become apparent from the following detailed description, discussion
and the appended claims taken in conjunction with the accompanying
drawings.
BRIEF DESCRIPTION OF DRAWINGS
Preferred structural embodiments of this invention are disclosed in
the accompanying drawings in which:
FIG. 1 is a block diagram outlining the entire printing system and
process;
FIG. 2 is a diagrammatic view of one embodiment of the alphanumeric
character forming means, employing a liquid crystal matrix for each
character;
FIG. 3 is a partial plan view showing a line matrix instead of the
single character matrix of FIG. 2;
FIG. 4 is a view similar to FIG. 2 but showing a two-stage
alphanumeric character forming system employing a circular liquid
crystal matrix;
FIG. 5 is a partial sectional view of the liquid crystal matrix
illustrated in FIG. 4; and
FIG. 6 is a partial plan view showing a multiple adjacent line
matrix for forming graphic images.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The schematic block diagram of FIG. 1 clearly illustrates the
entire printing system of the instant invention. Input 10 may be
either a keyboard or computer input for translating the data which
is to eventually be retranslated and printed. In easily understood
language, input 10 is a properly programmed computer which in and
of itself forms no part of the instant invention. Data from input
10 is then conveyed to a matrix bit encoder 12 which performs its
usual function of transforming raw input data into proper sequence
to be eventually fed to the alphanumeric character forming means
and printout. Next, a ring counter 14 may be used to switch from
alphanumeric character matrix to alphanumeric character matrix
(e.g., FIG. 2) or, in another embodiment, the bit encoder 12 may be
arranged to program an entire alphanumeric character matrix line
(FIG. 3) for more acceptable, differential character spacing for
even line printout.
Liquid crystal matrix 16 forms characters via a common electrode
and multiple input electrodes which change each liquid crystal
input bit from opaque to clear to form a complete character, as
will be further explained below. Alternatively, the specific liquid
crystal used may turn from clear to opaque when receiving an
impulse; both types of liquid crystals are currently commercially
available. Through fiber optics 18 arranged to one side of the
matrix 16 and a steady or intermittent light source 20 on the other
(FIG. 2) the alphanumeric character is conveyed to an optical input
printer 22 which, in a preferred embodiment, comprises a
xerographic machine 24 (FIG. 2).
As shown in FIG. 2 and at the right side of FIG. 4, the liquid
crystal matrix 16 comprises an alphanumeric character block
comprising seven rows of five liquid crystal bits each, or a total
of 35 data input, binary ("off-on") bits 26 to form the desired
alphanumeric character. This arrangement of bits to comprise an
alphanumeric character display is classic, described in the prior
art discussed above, and is clearly shown in the Hyland U.S. pat.,
No. 2,632,386.
As hereinbefore set forth, computer 10, encoder 12 and ring counter
or matrix switcher 14 operate in the usual manner; a bundle of 35
input lines 28 electronically conveys the translated input data to
the liquid crystal matrix 16, one input line being provided for
each liquid crystal bit 26 (FIG. 2). By way of example, suppose it
was desired to display the letter "I" on the single matrix 26. Such
a single matrix is also shown in FIG. 4, numbered 30. Each bit 32
of matrix 30 is numbered left to right by successive rows from 1 to
35. To form the letter "I," the bits 32 numbered 2, 4, 32, 34, and
the central vertical column numbered 3, 8, 13, 18, 23, 28 and 33
would be activated to display the letter "I." Similarly in FIG. 2,
the central vertical column of bits 26 would be charged along with
the bits to either side of the vertical column at top and bottom to
display the letter "I."
Unlike prior art devices, display and transfer of alphanumeric
characters on the matrix 16 and transfer of the characters to
printout means is entirely optico-electronically actuated to
completely eliminate any need for mechanical devices and thus
impart a high degree of stability and reliability to the entire
printing system.
Specifically, each alphanumeric bit 26 comprises a liquid crystal,
a cholesteric compound having significant electrooptical
properties. These cholesteric compounds are marketed by Eastman
Kodak Company of Rochester, New York, and are described and listed
in detail in Eastman's Liquid Crystals Kodak Publication No. JJ-14.
The compounds are of smectic and nematic varieties, the nematic one
being the type possessing electro-optical properties.
By way of background, liquid crystals are incomplete or
semicrystalline structures having two distinct mesomorphic states,
the first being nematic, wherein the orientation of molecules or
atoms making up the crystal are arranged in parallel lines but not
uniformly layered, and the second state being smectic, wherein the
orientation of molecules or atoms making up the crystal are
oriented in parallel planes or layers. The present invention is
concerned with the utilization of nematic cholesteric compounds of
the type disclosed in the hereinbefore identified Eastman Kodak
publication.
One suitable cholesteric liquid crystal for use in the present
invention is Eastman Kodak's No. 11643 nematic mixture having the
following enumerated properties:
Temperature Range: 15.degree.-97.degree.C.
Rise Time: 10 milliseconds
Decay Time: 350 milliseconds
Response Time: 8 milliseconds
Resistivity: 6.67 x 10.sup.9 Ohm-cm.
Threshold Voltage: 4 Volts
Optimum Voltage: 40 D.C.; 50-60 A.C.
Contrast Ratio: 100 to 1
Transmittance, Clear State: 78 percent
Transmittance, Saturated State: 0.1%
Excitation Source: 200 volts, peak to peak
Measurements Made: 0.5 .times. 0.5 cm. cell nesa coated glass with
a 0.5 mil. teflon spacer, in excess of 5,000 continuous A.C.
hours.
This specific compound is quite suitable for the present invention
particularly for its clear (uncharged) to opaque (charged) light
transmission characteristics set forth above. Of course, the
particular liquid crystal used could be of the opposite charged
variety, or clear when charged, turning opaque when uncharged. In
the present embodiment, the clear (uncharged) to opaque (charged)
variety is desirable so that transfer directly to xerography
printout means may be used without need of white-on-black light
reversal. Additionally, it is rather easy within the present state
of the art of liquid crystals to reduce the decay time from 350
milliseconds as in the above compound to 50 milliseconds or less,
for even higher speed operations.
Returning now to a further discussion of FIG. 2, specific
alphanumeric liquid crystal bits 26 are electrically charged to
form the individual character programmed and received from bundle
28. A steady or intermittent light source 20 shines through matrix
16, properly charged to form the letter "I" for example as
hereinbefore set forth, so that individual strands 34 of a fiber
optics bundle 36 collect the image rearwardly of matrix 16. Of
course, in this case, there are 35 fiber optic lines 34 provided,
one for each liquid crystal bit 26. Although bundle 36 is
identified as a fiber optics bundle, obviously it could be a
projection lens to easily serve the purpose of conveying the
character image to be printed to the xerographic printer 24. In any
event, the formed character is optically conveyed to the selenium
drum 38 of the xerographic printer, which is plus charged in the
usual manner as indicated. Other standard components shown of the
xerographic printer 24 include a charging potential 40, printing
resin pickup tray and contents 42, heater 44, and a paper supply
roll 46 conveying an endless printing paper supply beneath drum 38
for printout of the electro-optically conveyed character.
The immediately preceeding discussion concerned the entire process
of image forming, conveying and printing of but a single character;
obviously, an entire line of such individual alphanumeric
characters will be sequentially activated from the ring counter 14
in order to print a complete line, in the present embodiment. Once
a complete line has been projected, the selenium drum 38 is
advanced by a signal from the input 10 to prepare drum 38 to
receive another line of characters. Alternatively, the drum could
also be advanced at a predetermined rate, with transmission of a
signal at the time of each advance to input 10 to activate display
of the next character line in the matrices 16.
Instead of a row of individual liquid crystal matrices 16 being
used to form each character individually, matrix 16 may be in the
form of a single complete line matrix 48, as partially shown in
FIG. 3, comprising any desired number of vertical columns of seven
liquid crystal bits 26 each, so that differential spacing of
alphanumeric characters to form even line printout may be
accomplished. Thus, the matrix switching unit 14 will be arranged
to program an entire alphanumeric liquid crystal matrix line 48
with all characters in the line displayed simultaneously, rather
than equentially as in the case of an individual alphanumeric
matrix 16. Similarly, several lines 48 may be provided to be
actuated simultaneously to even further speed up the printout
process.
The precise shape of each alphanumeric bit 26 or 32 is not crucial;
the individual bit may be square as shown, circular or bar shaped,
all three varieties being popular in alphanumeric character
displays.
Turning now to FIGS. 4 and 5, another embodiment of the invention
is illustrated wherein each alphanumeric character is formed in two
stages, using a circular liquid crystal matrix 50 as a primary data
receptor from the switching matrix or ring counter 14, and a
secondary, alphanumeric character display or block 30 which is
optically energized by suitable light conveying means from circular
matrix 50, means 51 preferably being an optical fiber bundle
comprising 35 strands keyed by numbers, as illustrated from
circular matrix 50 to alphanumeric character block 30. The
structure of circular liquid crystal matrix 50 is best illustrated
in the partial cross-section view of FIG. 5. Matrix 50 comprises
glass plates 52 and 54 having facing transparent electrodes 56 and
58 coated thereon respectively in a known manner. In this case, the
common electrode will be 58, coating the entire surface of glass
plate 54, and indicated as "C" in FIG. 4, while the individual
transparent electrodes for each of the alphanumeric bits is formed
on glass plate 52, by etching away electrode material to form the
contacts 56 as shown in FIGS. 4 and 5. An insulated gasket spacer
60 separates common electrode 58 and each individual electrode 56
while the cholesteric nematic liquid crystal is located
therebetween at 62. A lens 64 receives light or no light through
crystal 62 from light source 66 and conveys the optical impulse
received to a strand 68 of fiber optics bundle 51. Thus
alphanumeric block 30 receives optical impulses which are displayed
on the face thereof and transmitted to final printout in the same
manner as shown in FIG. 2 and described above. In this embodiment
then, block 30 is essentially a transparent view block rather than
a liquid crystal matrix as in the embodiment of FIG. 2. The reason
for forming the matrix in the manner shown in FIG. 4 is for cost
savings, since each circular liquid crystal matrix 50 can be
rapidly and inexpensively formed by well-known processes. The
excitation of each crystal in matrix 50 is as before; an impulse is
received in one or more electrodes 56 to turn crystal 62 from clear
to opaque (or opaque to clear) in order to form the desired
character by optical transmission to block 30.
As set forth above, several simultaneously actuated line matrixes
48 may be provided to speed up the printout process. Additionally,
as shown in FIG. 6, several lines 48 may be formed adjacent one
another to display any graphic design desired, such as indicated at
70, by excitation of the appropriate liquid crystals in each
line.
The invention may be embodied in other specific forms without
departing from the spirit or essential characteristics thereof. The
present embodiments are therefore to be considered in all respects
as illustrative and not restrictive, the scope of the invention
being indicated by the appended claims rather than by the foregoing
description, and all changes which come within the meaning and
range of equivalency of the claims are therefore intended to be
embraced therein.
* * * * *