Planar alphanumeric display

A display device for alphanumeric characters using a sixteen segment configuration for each character, eight segments in an outer ring and eight segments in an inner configuration. The segments are joined in an eight-by-two matrix which is multiplexed, there being two time intervals for each character. The display medium may be liquid crystal or any other known dual plane medium such as colloidal suspension. In one plane, the inner eight segments are multiplexed into one group, while a second group multiple extends to the external eight segments. In the other plane, each outer segment is connected in series with an inner segment to form eight segment pairs. To display a desired character, selected pairs in one plane are energized with either the inner or outer multiple during one time interval to illuminate all segments common to the selected pairs and the selected group. During a second time interval, other selected pairs are energized with the other group. Successive characters are driven sequentially.

BACKGROUND OF THE INVENTION 
Liquid crystal displays are, of course, known for numeric displays and 
alphanumeric displays. Multiplexing of such displays is also well-known as 
indicated by the article entitled--Multiplexing Liquid--Crystal Displays 
on pages 113-121 of Electronics Magazine (McGraw-Hill Publication) for May 
25, 1978. 
In that article, an approach to multiplexing a numeric character with its 
characteristic seven segment display is shown. It is also well-known that 
by applying the energizing voltage in pulses at a sufficiently high 
frequency to different segments, the pulsed segments appear to be 
continuously illuminated to the eye of a viewer. See U.S. Pat. Nos. 
3,781,863 issued Dec. 25, 1973 to K. Fujita, and 3,945,001 issued Mar. 16, 
1976 to G. Shimakawa. 
Other two-plane displays using colloidal or fluid suspensions in place of 
the liquid crystal are also known as shown by U.S. Pat. Nos. 3,655,267 to 
Forlini as issued Apr. 11, 1972 and 3,708,219 to Forlini et al issued Jan. 
2, 1973. 
SUMMARY OF THE INVENTION 
The present invention is directed to an improved alphanumeric display for 
use with a two panel light display in which the medium may be liquid 
crystal, colloid suspension or the like. Segments comprising a character 
are multiplexed in a two-step, eight-by-two pattern. 
The pattern of segments for each character includes eight peripheral 
segments forming a rectangle of an outer group. Eight segments in a star 
burst pattern form the inner group. On one plate, the outer group segments 
are connected together. On the other plate, the segments are paired with a 
segment of the outer group paired with an adjacent segment of the inner 
group in each pairing. By energizing one group with selected segment pairs 
in one time frame and selected segment pairs and the other group during a 
second time frame, a complete alphanumeric set of characters may be 
formed. 
It is therefore an object of the invention to provide a planar, two panel 
alphanumeric data display which may be multiplexed in a two interval, 
eight-by-two time multiplex sequence for characters in a multiple 
character display. 
It is a further object of the invention to provide an alphanumeric display 
using two planar panels in which there are plural segments for each 
character superimposed on each panel, with the segments of one panel being 
grouped in multiple segment groups and with the segments on the other 
panel paired, and with a segment of each pairing including one segment 
from each group. 
It is a still further object of the invention to provide a two panel planar 
display in which each character of the display includes segments on each 
panel in substantial alignment with segments on the other panel and in 
which the segments on one panel are grouped and the segments of the other 
panel are paired with one segment of a pairing in each group, and in which 
selected segments of one panel are electrically driven simultaneously with 
driving of said one group on the other panel, followed by a second driving 
of selected segments of said first panel with driving of said second group 
.

DETAILED DESCRIPTION OF THE DRAWINGS 
In FIG. 1, I show my invention as applied to a single character using 
liquid crystal device or colloidal suspension construction. As seen in 
FIG. 1, there is the front plate 12 with the present segment 
configuration, the paired glass plates 14 and 16 with the crystal material 
and sealant 17 disposed between the two plates as is well-known in the 
art. The rear plate 18 also has the specific character configuration of my 
invention. 
The segments 20 of the display constitute the elements of the figure eight 
of the conventional numeric display, wth the horizontal portions for each 
level, top, middle and bottom, being dual segments. These segments are 
transparent conductors secured to a respective plate that are chemically 
coated in any conventional technique such as that of the cited Electronics 
Magazine article. The center horizontal segments are part of an interior 
star burst pattern of segments radiating from the center of the character, 
there being eight radial segments, two horizontal, two vertical, and four 
other segments disposed 45.degree. from the horizontal and vertical. Thus, 
there are sixteen segments, eight interior segments in the interior or 
star burst grouping and eight segments of the outer or peripheral 
grouping. The outer grouping includes two in-line verticals at each side 
and two in-line horizontals at the top of the character and two in-line 
segments at the bottom of the character. 
In FIG. 2, I show the construction using my invention in which the optical 
medium is either colloidal suspension or a gas discharge device. In this 
embodiment, the rear plate 30 is fabricated of glass and has conductors 31 
connected to the segments on one face thereof, the conductors being 
preferably of tin oxide. The segments 20 of the single character of FIG. 2 
are arrayed on the rear plate 30 and the front plate 32. This plate is 
also fabricated of translucent glass and sandwiched between the two plates 
is the spacer frit 34 containing the optical medium 36 such as colloidal 
suspension or gas discharge device. The front plate 32 has the paired 
segments connected by the conductor multiple 35 to a suitable current 
source. 
FIG. 3 shows the layout of the segments of the front plate to form eight 
segment pairings, labeled 1-8. Each pairing includes a segment from the 
outer grouping and a segment from the inner grouping. Thus, for example, 
the pairing labeled #1 has a top right horizontal segment (a) of the outer 
grouping and the segment (b) angled 45.degree. from segment (a). Segment 
pair 2 includes the top left horizontal (a) segment and the center 
vertical (b) segment. In a like manner, the segments of the respective 
pairings 3-8 include an (a) segment and a (b) segment. Each pairing is 
connected by the conductor shown to a suitable current source (not shown), 
which may be any suitable source. 
FIG. 4 shows the layout of segments on the back plate. The sixteen segments 
of the back plate are in superimposed alignment with the like segments on 
the front plate. The segments of the back plate are joined within the 
groupings labeled "Outside or a" and "Inside or b". The outside segments 
comprise the peripheral segments and the inside segments comprise the star 
burst interior pattern. Each of the two groupings as shown is connected by 
a conductor to its current source. 
To display a particular character, a two step or two period multiplexing is 
undertaken. For example, to produce the letter A and referring to the 
segments in FIG. 1, it can be seen that segments 5a, 3a, 2a, 1a, 4a, 6a 
and 4b and 5b would have to be illuminated or visibly driven. Note that 
these segments are both in the a or outer grouping and b or inner 
grouping. In the two period driving of the character for the first period, 
the a or outer grouping of the back plate is driven along with driving of 
the 1-6 pairs of FIG. 1. During this period, the outer segments 1a, 2a, 
3a, 4a, 5a and 6a would be illuminated. During the second time period, the 
inner or b grouping of the back plate of FIG. 4 is driven while on the 
front plate only 4 and 5 pairs are driven. During the second period, the 
center bar is illuminated by driving segments 4 and 5 and the b grouping. 
As is well-known, due to the high rate at which the character is 
multiplexed, the letter A appears as the result of these two periods or 
steps. In a like manner, all alphanumeric characters can be illuminated by 
an eight-by-two, two period multiplexing. The order set forth for the two 
steps, i.e., outer and then inner could readily be reversed, if desired. 
The eight pair conductors, or eight multiples of the eight-by-two matrix, 
as it may be called, may be signalled as the eight bits of an address 
using conventional eight bit computer addressing. 
FIGS. 5 and 6 show a five character display, with FIG. 5 showing the front 
plate and FIG. 6 the rear plate. In these figures, the characters of each 
plate are identical to one another. In FIG. 5, the pairs are individually 
coupled by separate conductors 1-8 to the current source (direct cross 
connection of like interior segments to other characters has been omitted 
from FIG. 5), and in FIG. 6 the two groups are connected to their 
respective conductors a and b for each character. In this way, a ten 
interval sequence of respective a and b periods would constitute a five 
character frame. During each period, the selected pairs of the front plate 
would be energized to produce that portion of a character, the characters 
being driven in sequence from left to right. 
Any suitable addressing technique could be used for the selection of 
desired pairs, the selection data as shown by table A being readily 
adaptable for storage in a suitable memory, not shown herein. Further, as 
is well-known, a series of frames would enable the display to be visible 
to the eye of a viewer as if it were continuously energized. 
The table shown herein is only one exemplary form of alphanumeric display. 
It is clear that other combinations could be used where the shape of a 
character is in other preferred forms. 
TABLE A 
______________________________________ 
a b 
______________________________________ 
A 1-6 4,5 
B 1-3,5,7,8 1,5,6 
C 1-3,5,7,8 -- 
D 1,2,4,6-8 2,8 
E 1-3,5,7,8 4,5 
F 1-3,5 5 
G 1-3,5-8 4 
H 3-6 4,5 
I 1,2,7,8 2,8 
J 1,2,5,7 2,8 
K 3,5 1,5,6 
L 3,5,7,8 0 
M 3-6 1,3 
N 3-6 3,6 
O 1-8 -- 
P 1-5 4,5 
Q 1-8 6 
R 1-5 4-6 
S 1-3,6-8 4,5 
T 1,2 2,8 
U 3-8 -- 
V 3,5 1,7 
W 3-6 6,7 
X -- 1,3,6,7 
Y -- 1,3,8 
Z 1,2,7,8 1,7 
1 -- 2,7 
2 1,2,4,5,7,8 4,5 
3 1,2,4,6-8 3,4 
4 3 
5 1-3,7 8 
6 1-3,5-8 4,5 
7 2 2,8 
8 1-8 4,5 
9 1-4,6-8 4,5 
0 2,3,5,7 2,8 
______________________________________