U.S. patent number 3,745,563 [Application Number 05/216,360] was granted by the patent office on 1973-07-10 for arrangement for preserving the free rotatability of the individual vanes in composite display devices.
This patent grant is currently assigned to Display Technology Corporation. Invention is credited to William Ross Aiken, Charles E. Jones.
United States Patent |
3,745,563 |
Jones , et al. |
July 10, 1973 |
ARRANGEMENT FOR PRESERVING THE FREE ROTATABILITY OF THE INDIVIDUAL
VANES IN COMPOSITE DISPLAY DEVICES
Abstract
In composite display devices of the rotatable vane type wherein
rows of juxtaposed vanes are rotatably supported upon common
horizontally disposed axles and are selectively turned on said
axles under the influence of electrostatic fields, coacting guide
means are provided on the vanes and the support structure for the
axles, for confining each vane during its performance to its
predetermined position axially of its axle. Thus, displacement and
lateral contact of adjacent vanes on the axles with resultant
impairment of their free individual rotatability is prevented
without need to use spacer beads between them.
Inventors: |
Jones; Charles E. (Lincolnwood,
IL), Aiken; William Ross (Los Altos Hills, CA) |
Assignee: |
Display Technology Corporation
(Cupertino, CA)
|
Family
ID: |
22806747 |
Appl.
No.: |
05/216,360 |
Filed: |
January 10, 1972 |
Current U.S.
Class: |
340/815.88;
40/447; 40/583 |
Current CPC
Class: |
G08B
5/22 (20130101); G09F 9/372 (20130101) |
Current International
Class: |
G09F
9/37 (20060101); G08B 5/22 (20060101); G09f
009/30 () |
Field of
Search: |
;40/28C,13J
;340/324R,378,336 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Caldwell; John W.
Assistant Examiner: Curtis; Marshall M.
Claims
We claim:
1. In a display device of the type controlled by electrostatic
fields the improvement comprising a support structure, a plurality
of coplanar parallel axles held in said support structure, a
plurality of vanes rotatably supported side by side from each of
said axles, electrostatic electrode means for turning said vanes
individually on said axles, and coacting guide means on both said
support structure and each of said vanes in centeral areas thereof
for confining said vanes individually to predetermined positions
axially of said axles.
2. A display device according to claim 1 wherein said coacting
guide means comprises a slot within a central area of each of said
vanes having side edges lying in axially spaced planes normal to
the axle for the vane and a projection of said support structure
slidably engaged in said slot.
3. A display device according to claim 2 wherein the end of said
projection protrudes through said slot and said axle is supported
in the outwardly projecting end thereof.
4. A display device according to claim 1 wherein said co-acting
guide means comprise axially spaced lugs projecting from a central
area of a surface of said vane and a projection of said support
structure slidably engaged in the space between said lugs.
5. A display device according to claim 4 wherein said axle is
supported in said projection near the end thereof and the end edge
of said end is semicircular with the center of its circle
substantially coincident with the axis of said axle.
Description
The present invention relates to adjustable display devices of the
type composed in the manner of a mosaic of a plurality of
juxtaposed and superposed individually adjustable display units
each so constructed that sheet-like vanes may selectively be set to
display or "read" positions wherein they present one of two
surfaces to the viewer, or an "erase" position wherein they present
one of their edges to the viewer and are, therefore, practically
invisible. An example of a display device of this type is disclosed
in U.S. Pat. No. 3,089,120. The required movements of the vanes
about their axis of rotation may be effected by electrostatic
forces, such as described in the mentioned U.S. Pat. No.
3,089,120.
For reasons of simplicity the vanes of a horizontal row of
juxtaposed display units may be hingedly supported side by side
upon a common, horizontally disposed axle or hinge rod. This
practice, however, has introduced problems of its own. The
individual vanes may shift upon the axles relative to one another,
their side edges may come into contact with each other and
obstruct, or at least impair, their individual movability, and the
vertically superposed vanes in superposed rows of display units may
lose precise vertical alignment with each other, thus rendering the
whole display apparatus unsightly. Attempts have been made to avoid
these malfunctions by interposing spacer beads or washers upon the
axles between the edges of adjacent vanes, but the results are not
satisfactory. The beads or washers interfere with the free
movability of the individual vanes, especially when whole groups of
vanes upon a common axle shift laterally in one direction, and the
pressure of several such displaced vanes upon an adjacent vane that
did not shift, becomes cummulative; and the interposition of beads
or washers between adjacent vanes does not necessarily maintain
precise vertical alignment between corresponding vanes in the
superposed rows of a display device of the type here under
consideration. Last but not least, the interposition of spacer
beads and washers places an increased load on the free rotatability
of the adjacent vanes and increases very considerably the
complexity of the assembly.
It is an object of the present invention to provide a composite
display device, of the type here under consideration wherein the
free individual movability of all the adjustable vanes is at all
times assured.
Another object of the invention is to provide a display device, of
the type referred to, wherein the corresponding display vanes in
superposed rows of individual display units remain at all times
precisely aligned vertically.
Still another object of the invention is to provide a display
device of the type referred to that is of simple and inexpensive
construction and which is easy to assemble.
These and other objects of the present invention will be apparent
from the following description of the accompanying drawings which
illustrate certain preferred embodiments thereof and wherein
FIG. 1 is a fragmentary front elevation of a display device
embodying our invention;
FIG. 2 is a fragmentary perspective, viewed from the rear, of one
of the vanes of the device shown in FIG. 1;
FIG. 3 is a vertical section through the device taken along line
3--3 of FIG. 1 and viewed in the direction of the arrows associated
with said line;
FIG. 4 is a side elevation, similar to FIG. 3, representing a
modified embodiment of the invention;
FIG. 5 is a perspective of the embodiment of the invention shown in
FIG. 4 viewed from the rear of the display vane, and
FIG. 6 is a fragmentary front elevation of a vane of this device of
the invention viewed in the direction of the arrow 6--6 in FIG.
4.
In accordance with the invention we provide between each individual
vane and the stationary support structure of the composite display
device coacting guide means that confine each vane to its
predetermined horizontal position axially of the common axle. In
this manner the edges of adjacent vanes upon a common axle are at
all times properly spaced, and though the spacing may be minute,
adjacent vanes can never come in contact with ach other, and impair
their individual performance. Also, the described guide means
between the stationary supporting structure of the display device
and the individual vanes assures at all times that the
corresponding vanes in superposed rows of the display device remain
in precise vertical alignment.
Having reference to FIGS. 1, 2 and 3 the reference numeral 10
designates sheet-shaped vanes or flags of sheet material, such as
aluminum foil. In the preferred embodiment of the invention these
vanes are of square shape and their front surfaces 12 are painted
in black or a dark color. In composite display devices of the type
briefly described hereinbefore a row of horizontally juxtaposed
vanes 10 is hingedly supported upon a common horizontally disposed
axle or hinge rod 14 by means of bearings 16a and 16b located at
either side of the vanes; they are individually movable between an
upright position wherein they present their dark surface to an
observer in front of the display device and an approximately
horizontal or lying-down position wherein they present their front
edge 18 to the observer and are therefore practically invisible to
him. In the preferred embodiment of the invention which we are
about to describe, the described movement of the vane is effected
by vane-attracting electrostatic forces exerted upon the vane, for
instance, by an electrode 20 located on the underside of a support
arm 22 that projects outwardly from a common supporting structure
24. Whenever the electrode 20 in energized, the electrostatic field
established by said electrode pulls the vane 10 upwardly into a
substantially horizontal position wherein it presents its top edge
18 to an observer in front of the display device and is therefore
practically invisible to him. This position is called the "erase"
position of the individual display unit. Deenergization of
electrode 20 allosw the vane 10 to swing downwardly under the force
of gravity into an upright display position determined by
energization of another vane-attracting electrode 26 supported on
the upper edge of another arm 22 located below, and identical in
shape with, the first mentioned arm 22. In this position the vane
presents its dark outer surface to the observer in front of the
display device, for which reason this position is known as the
"display" or "read" position of the individual display unit.
As indicated in FIG. 1, several horizontal rows of juxtaposed
display vanes may be arranged above and/or below each other, with
corresponding vanes in the superposed rows in precise vertical
alignment with one other; and by placing selected vanes into
display position while keeping the remaining vanes in erase
position, letters, symbols and messages may set up in dark color
upon the display area formed by the front surface of the device
against the background of the device, which is visible behind the
vanes in erase position and which is usually given a bright
appearance.
In accordance with the embodiment of the invention illustrated in
FIGS. 1 to 3 each of the vanes 10 is provided with a slot 28 whose
side edges extend normal or perendicular to the axis of rotation of
the vane; and slidably engaged into said slot is the free end 30 of
the hereinbefore mentioned arm 22 of the common support structure
24. The end 30 of arm 22 of the support structure 24 and the side
edges of slot 28 in the vane 10 constitute guide means whether the
vane is in motion or in one of its positions of rest, that confine
the vane precisely to its position axially of the hinge axle 14 so
that the vanes cannot shift on the axle and come into contact with
each other and block or impair their free individual movability.
Also, due to the described guide means 28/30, the vertically
aligned vanes in superposed rows remain in precise alignment with
each other so that the composite display device of the invention
retains its neat and orderly appearance for extended periods of
time in spite of rugged conditions of use and hard wear.
The tips 30 of arms 22 are arranged to protrude through the guide
slots 28 in the vane, and the common axle 14 of a row of juxatposed
vanes 10 is held in said protruding tips 30 of arms 22 (FIGS. 2 and
3). The proximity of the hinge axle to the contact area between the
end 30 of arm 22 and the confining guide sides of slot 28 provides
a leverage advantage that minimizes the danger of the vane clinging
frictional to the tip 30.
In the embodiment of the invention illustrated in FIGS. 4, 5 and 6
the co-acting guide means between the vane 10' and the support
structure 24' of the display device are formed by a pair of lugs or
ears 40a and 40b on the back of the vane 10', i.e. the surface
opposite to the display surface, which present to the tip 30' of
the support arm 22' two axially spaced guide surfaces, that extend
in planes perpendicular to the axis of rotation. For smooth
operation of the vane the tip 30' of the support arm 22' is
semicircular, and the common axle 14' for all the vanes in a row of
juxtaposed vanes passes for support through an orifice around the
geometrical centre of the circle defined by the semi-circular ends
30' of the arms 22'. In FIG. 4 the reference numerals 20' and 26'
designate the erase electrode and the display electrode,
respectively, corresponding to electrodes 20 and 26 of the
embodiment of the invention represented by FIGS. 1, 2 & 3 and
the reference numeral 42 identifies a spacer element on the back of
the vane 10 that strikes against support 22' when the vane swings
into its erase position, and prevents contact between the
conductive vane and the energized electrode, and sets the vane to a
precisely horizontal position.
By the guide means of the invention as exemplified by the
embodiments of the invention illustrated in FIGS. 1 to 6 free
individual moveability of the vanes on a common axle and precise
alignment of corresponding vanes in superposed horizontal rows are
assured. Adjacent vanes cannot come into contact with each other,
and spacers between adjacent vanes which place a load on adjacent
vanes, that impairs their rotatability, may now be dispensed
with.
While we have explained our invention with the aid of certain
preferred embodiments thereof, it will be understood that the
invention is not limited to the specific constructional details
shown and described by way of example which may be departed from
without departing from the scope and spirit of the invention.
* * * * *