U.S. patent number 3,825,927 [Application Number 05/138,728] was granted by the patent office on 1974-07-23 for magnetic discboard.
Invention is credited to Renold R. Passien.
United States Patent |
3,825,927 |
Passien |
July 23, 1974 |
**Please see images for:
( Certificate of Correction ) ** |
MAGNETIC DISCBOARD
Abstract
A magnetic display device of the type wherein magnetized discs
are selectively moveable within closely spaced openings or chambers
in a laminated panel, the panel including a pair of magnetized
sheets with their magnetic poles similarly disposed, openings
extending through both sheets, and a bipolar magnetized disc
positioned within each opening for rotation and shuttle movement
under the influence of a selectively applied magnetic field, and
non-magnetic cover sheets secured to opposite surfaces of the
magnetic sheets. A light panel is mounted on the rear surface of
the laminated panel. Shuttling of the discs with a magnetic stylus
from the rear, a position of rest (erase state) to the front (write
state) exposes a ray of light in each chamber. The display of
individual characters is achieved by the forward and rear movement
of the individual discs in each chamber. When the discs are in the
rear (erase state), they block the rays of light coming through the
rear panel. This is easily accomplished since the diameter of the
chambers in the rear is smaller than the diameter of the front
chambers. However, when the discs are in the (write state) forward
position, the ray of light from each chamber is free to travel to
the front panel. This then presets (in the dark) a pattern of
characters in the form of small dots of light.
Inventors: |
Passien; Renold R. (Campbell,
CA) |
Family
ID: |
22483355 |
Appl.
No.: |
05/138,728 |
Filed: |
June 14, 1972 |
Current U.S.
Class: |
340/815.53;
340/815.86; 345/111; 40/449 |
Current CPC
Class: |
G02B
26/026 (20130101); G09F 9/375 (20130101) |
Current International
Class: |
G09F
9/37 (20060101); G02B 26/02 (20060101); G08b
005/24 () |
Field of
Search: |
;350/373,378C |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Pitts; Harold I.
Attorney, Agent or Firm: Crouch; Robert B.
Claims
What is claimed is:
1. A magnetic display device including a pair of magnetized sheets
positioned parallel to each other with their magnetic poles
similarly disposed, a series of spaced openings extending through
each of said sheets, a bipolar magnetic disc positioned within each
opening for rotation about a lateral axis of the opening and
movement along the longitudinal axis of the opening, and a
nonmagnetic cover sheet secured to each magnetized sheet, the cover
sheet secured to one magnetized sheet being transparentn while the
cover sheet secured to the other magnetized sheet is rigid and is
provided with a series of holes smaller in diameter than said
discs, the holes being aligned with the openings.
2. The display device of claim 1, where a panel of electric light
with a simple switch is laiminated to the back of the display,
thereby making it possible to use it in the dark as a pattern of
alphanumeric characters written in lights.
3. Magnetic display device of claim 1, wherein the rigid cover
sheet is made of steel making the device more durable and stable
and, hence, acceptable for use in public schools as a replacement
for the chalkboard.
Description
BACKGROUND OF THE INVENTION
This invention relates to a honeycomb magnetic display device
wherein individual magnetic discs or metal slugs rotate under an
electromagnetic force induced by either an external magnetic stylus
or through a wire matrix.
DESCRIPTION OF PRIOR ART
Display devices, nonmagnetic, magnetic, and electromagnetic are
well known in the art.
Magnetic display systems can be grouped into the following major
categories:
1. Those using a magnetic stylus to bring a magnetic element into
view, such as the C.R. Tate U.S. Pat. No. 3,036,388 as U.S. Pat.
No. Re. 25,822 on 07/20/65, W. J. McDonald U.S. Pat. No. 3,103,751,
J. R. Herzog U.S. Pat. No. 2,853,830, and R. P. Dingwall U.S. Pat.
No. 3,426,453.
2. Those using electromagnetic force to rotate and display a
magnetic slug, such as: J. R. Knight U.S. Pat. No. 3,036,300, J. M.
Cunnien, U.S. Pat. No. 3,162,849, and M. K. Taylor U.S. Pat. No.
3,140,553.
3. Those using magnetic stylus or electronic circuitry to open or
close a chamber to show light, such s: J. H. Todt U.S. Pat. No.
3,186,115, and C. W. Jacob U.S. Pat. No. 3,210,757.
The foregoing advantages and features of this invention will be
more apparent with the detailed description of its working
principles and its fabrication techniques as illustrated in the
accompanying illustrations.
ILLUSTRATIONS
FIG. 1 is a plan view of the magnetic discboard
FIG. 1a is the magnetic stylus.
FIG. 2 is an elevation view in section of a preferred embodiment of
the present invention.
FIG. 3 is an exploded view in perspective of another embodiment of
the invention showing its three functional layers. covers and a
panel of rear light.
FIG. 4 is a cross section of the embodiment of FIG. 3
FIG. 5 is further embodiment of a monomagnetic device with a
plurality of cavities instead of holes.
FIG. 1 shows a honeycomb section 11 formed from a permanently
magnetized laminated board provided with a multiplicity of openings
12 and covered with a transparent lamina and attached to a panel of
light. Each opening or chamber 12 contains a magnetic disc 13 with
contrastingly colored faces. SInce as illustrated in FIG. 2 the
brightly colored faces of the magnetic discs are opposite in
polarity (South) to the outer surface of the upper magnetic layer
(North) and to the outer surface of the lower magnetic layer
(North), it is possible, with the aid of a magnetic stylus (write
side=North pole) to display alphanumeric characters on the face of
this magnetic discboard. As the magnetic stylus is passed over the
board, the individual discs shuttle and rotate forward to present
their brightly colored faces to view. This presents a uniform and
reliable row of characters. In FIG. 1, the characters are formed by
discs (13) displaying their brightly colored faces in the write
position, while all other discs are in the rear (erase) position
showing their dark faces to the viewer. These characters ("T" and
"R") in ambient light appear as white dots against a dark
background. However, in the dark, with the rear panel light
switched on, these same characters appear as dots of light against
a dark background. FIG. 2 shows a cross-sectional view of a
preferred embodiment of a disc board wherein the honeycomb section
is formed from two magnetized sheets 14 and 15 positioned adjacent
each other with similar magnetic poles in proximity with each
other. A series of openings 12 extends through both magnetized
sheets and a bipolar disc 13 is positioned in each opening. A
non-magnetic transparent cover sheet 16 is positioned on the outer
surface of the lower sheet 15. The backing sheet is formed of
non-magnetic, opaque material and is provided with a series of
openings 18, each of which is smaller in diameter than and
positioned in line with an opening 12. A light panel which includes
a cover 19, a source of light such as bulb 21, and a switch 22 is
attached to the outer surface of the backing sheet. When the light
is on and the disc in in the erase position, the opening 18 is
blocked by the disc and no light is transmitted therethrough. When
the disc is in its write position, the opening 18 is clear and
light is transmitted through openings 18 and 12, around disc 13 and
through cover sheet 16.
FIG. 3 shows two different layers of magnetic material 24 and 25
sandwiched to the wire matric 23, whose vertical coordinates 32 and
horizontal coordinates 31 permit electrical sensing of one disc at
a time or a whole row of discs at one time. This wire matrix could
be replaced with printed circuitry, one coordinate on each of the
inner surfaces of magnetic layers 24 and 25. Significantly, it is
important to point out that opening 13 in layer 24 is equal in
diameter to the diameter of opening in the spacer matrix. However,
these diameters are larger than the diameter of opening 29 in layer
25. Now, since discs 33 are equal in diameter, it is easy to see
that with the aid of a magnetic stylus, 20, disc 33 in FIG. 4 with
its S-pole facing the N-pole of layer 25 can be shuttled and
rotated to face cover 26, showing its brightly colored face to the
viewer. When, disc 33 is in the write state it permits the light to
come through chamber 14 from the back light panel 19. In this
position, disc 33 is in a latching position with its N-pole facing
the S-pole of magnetic layer 24, while its S-pole is attracted and
held in position (flush against the transparent cover 26) by the
N-pole of magnetic layer 24.
Once again, by using the S-pole of magnetic stylus 20, we can erase
and shuttle disc. In this position, as it is clear from the
illustration (FIG. 4), disc 33 covers and blocks chamber 13,
thereby preventing any light to pass through. This is the erase
state. In this position, the n-pole of disc 33 faces the S-pole of
the upper magnetic layer 24, while its S-pole rests on the N-pole
of magnetic layer 25. BOth positions are stable and reliable.
Writing or erasing of discs (characters), is easily accomplished by
a magnetic stylus 20. It is quite apparent that this invention can
be used in the dark and in ambient light very effectively. As can
be seen from the illustration, unlike previous magnetic displays,
this invention is easily fabricable and quite economical. The
fabrication technique of this device itself constitutes one of the
claims of this invention.
FIG. 5 shows an embodiment in which openings 36 are drilled or
otherwise formed in a magnetized sheet 35 to form a series of
chambers in which are located the bipolar discs 37. A transparent
cover sheet 38 is placed on the upper surface of the sheet 35 to
close the openings and contain the discs therein.
FABRICATION TECHNIQUES
The magnetic layer is formed barium ferrite (BaFe.sub.2 O.sub.3)
powder mixed with polyvinyl material in a quantity of a minimum of
25 percent by weight and is produced in roll form, 9 inches wide
and 20 mils thick. This can be laminated to a 30 mil, nonmagnetic,
spacer (or prefabricated wire matrix) in the manner shown in the
illustration; that is, the S-pole of the magnetic layer is
laminated to the spacer. This lamina is punched with a pattern of
holes (100 mils center to center, 10 holes to a linear inch) whose
diameter is 75 mils. After this, another sheet of the same magnetic
material (9 inches by 20 mils thick,) is laminated to the first
lamina with its N-pole facing the spacer. After this has been
completed, a transparent cover, 10 mils thick, is laminated to the
outer surface of the magnetic layer. Now, this new lamina is put
under another die and punch unit with 50-mil diameter pins. The
lamina is punched with the magnetic layer on top of the device.
This not only provides smaller holes than the magnetic layer and
spacer but, most important and highly innovative, it leaves the
cut-outs (magnetic discs 20 mils thick and 50 mils in diameter)
right in the lamina. Thus, in one operation, we have fabricated and
assembled our magnetic elements into the display board. It is
assumed here that before laminating the second layer of magnetic
material to spacer, one side (South pole) of magnetic layer is
appropriately coated with a bright color, preferably white, to
contrast with the black color of magnetic layer.
It is important to note that this technique provides no waste
material. In addition, no magnetic elements (discs) are lost or
distorted.
After the lower magnetic layer has been punched and the discs are
all in their respective chambers, another transparent cover is
laminated to the outer surface of magnetic layer. This essentially
completes the fabrication techniques of the current invention.
However, it is important to attach a simple panel of electric light
to the back of transparent cover.
* * * * *