U.S. patent number 3,633,720 [Application Number 04/861,062] was granted by the patent office on 1972-01-11 for alphanumeric printing device employing magnetically positionable particles.
This patent grant is currently assigned to Honeywell Inc.. Invention is credited to Tommy N. Tyler.
United States Patent |
3,633,720 |
Tyler |
January 11, 1972 |
ALPHANUMERIC PRINTING DEVICE EMPLOYING MAGNETICALLY POSITIONABLE
PARTICLES
Abstract
A printing device is shown that uses a specially adapted paper
upon which alphanumeric characters may be printed without impact
and from which erroneously printed characters may be removed. The
alphanumeric character to be printed is selected by a keyboard
which electrically energizes core elements within a recording head.
The core elements generate a force field that reorients preoriented
highly reflective flakelike particles within the specially adopted
paper. The reorientation causes the reflective flakelike particles
to become absorbtive for forming a dark contrasting trace upon the
paper which represents the selected alphanumeric character. If an
error is made, the recording head may be utilized to remove the
erroneously selected alphanumeric character by again reorienting
the reflective flakes into their previous light-reflective
orientation.
Inventors: |
Tyler; Tommy N. (Littleton,
CO) |
Assignee: |
Honeywell Inc. (Minneapolis,
MN)
|
Family
ID: |
25334771 |
Appl.
No.: |
04/861,062 |
Filed: |
September 25, 1969 |
Current U.S.
Class: |
400/105; 324/214;
346/74.5; 400/74; 434/409; 396/549; 101/DIG.37; 346/74.3; 428/900;
400/118.3 |
Current CPC
Class: |
B41J
2/43 (20130101); Y10S 101/37 (20130101); Y10S
428/90 (20130101) |
Current International
Class: |
B41J
2/43 (20060101); G01d 015/12 () |
Field of
Search: |
;197/1,181 ;346/74MP
;178/7.5D,7.3D ;101/DIG.13,1 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Burr; Edgar S.
Claims
The embodiments of the invention in which an exclusive property or
privilege is claimed are defined as follows:
1. An alphanumeric printer comprising:
a supply of force-field-responsive paper;
said force-field-responsive paper including reflective,
force-field-responsive, and flakelike particles preorientated in
parallel with a plane of said paper for forming a uniform
background thereon with respect to incident light;
said flakelike particles being magnetic particles;
force-field-generating means for generating a magnetic force field
in the shape of a predetermined alphanumeric character in
juxtaposition with said force-field-responsive paper;
keyboard input means connected to said force-field-generating means
for selecting said predetermined alphanumeric character;
said reflective flakelike particles preorientated on said magnetic
force field responsive paper being arranged to reorient in response
to said generated magnetic force field for forming a contrasting
trace upon said uniform surface of said paper by altering the
response of the surface of said paper with respect to the incident
light thereon, said contrasting trace taking the form of said
selected alphanumeric character; and
erasing means for generating a magnetic force field capable of
orientating said reorientated reflective flakelike particles back
to the first-mentioned preorientated position in the event an error
is made in selecting said predetermined alphanumeric character;
said erasing means comprising:
switching circuit means;
means within said keyboard input means for energizing said
switching circuit means;
erasing head means for generating sensing signals in response to
previously recorded alphanumeric characters;
means connecting said erasing head means to said switching circuit
means for receiving said generated sensing signal within said
switching circuit means; and
means connecting said switching circuit means to said erasing head
means for applying an erasing signal thereto in accordance with
said received sensing signals.
2. An alphanumeric printer as claimed in claim 1, additionally
comprising:
said erasing head means including a pair of erasing heads having a
common paper-facing surface arranged on each side of said
magnetic-field-generating means;
core elements arranged within said erasing heads and exposed on the
paper facing surface thereof;
said pair of erasing heads sensing a correctly printed alphanumeric
character on each side of an incorrectly printed character and
generating said sensing signals accordingly; and
said switching circuit means applying said erasing signal to said
core elements deposed adjacent said correctly printed alphanumeric
character for creating a flux pattern through said
magnetic-field-responsive paper and erasing said incorrectly
printed character therebetween.
3. An alphanumeric printer as claimed in claim 2, additionally
comprising,
said magnetic-field-generating means including a recording head
having a paper-facing surface thereon;
said paper-facing surface of said recording head and said
paper-facing surface of said erasing heads angularly disposed to
each other;
flux-conducting means joining the core elements of said erasing
heads opposite the paper-facing surface thereof;
said erasing heads having coil means wound upon the core elements
thereof to generate a flux in one direction within the first
erasing head of said pair and to generate said flux in the other
direction within the second erasing head of said pair for passing
said flux through said first erasing head, said
magnetic-field-responsive paper, said second erasing head, and the
through said flux-conducting means thereby orienting said magnetic
flakelike particles within said magnetic-field-responsive paper
parallel to the plane thereof and erasing any alphanumeric
character printed therebetween.
Description
The present invention relates to an alphanumeric printing device;
and, more particularly, to an alphanumeric printing device which is
capable of impactlessly printing preselected alphanumeric
characters upon a specially adapted paper and which is capable of
erasing these selected alphanumeric characters should an incorrect
selection be made.
Alphanumeric printing devices, such as a common typewriter, are
well known in the prior art. These typewriters require many moving
parts, one for each alphanumeric character, and rely on the impact
of the moving parts against a carboned belt to print an
alphanumeric character upon a piece of paper. The prior art
typewriters have a response time which is limited by the mechanical
linkages therein. The time in which a completed document may be
printed or typed is also limited by the number of errors made by
the operator. More recent typewriters are provided with
electromechanical arrangements which reduce the number of moving
parts and thereby reduce the mechanical wear and the response time.
However, these typewriters are also subject to component failure
due to mechanical and electromechanical wear and the operator must
continue to correct erroneously selected alphanumeric characters
through the use of extra external equipment.
Accordingly, it is an object of the present invention to provide an
improved alphanumeric printing device.
It is another object of the present invention to provide an
alphanumeric printing device which is quiet, requires few moving
parts, and does not rely upon impact to print an alphanumeric
character upon a recording paper.
Still another object of the present invention is to provide an
alphanumeric printing device which is capable of printing a
plurality of preselected alphanumeric characters one line at a
time.
A further object of the present invention is to provide an
alphanumeric printing device wherein an alphanumeric character may
be selected and, should that selection be incorrect, corrected
without requiring stenographic accessories but relying wholly upon
internal components of the alphanumeric printing device.
Still a further object of the present invention is to provide a
simple alphanumeric printing device which requires few moving parts
thus reducing mechanical wear and decreasing the response time
thereof.
In accomplishing these and other objects, there has been provided a
recording paper which is responsive to a force field and a
force-field-generating head which generates a selected field
pattern depending on the alphanumeric character to be printed upon
the recording paper.
Other objects and many of the attendant advantages of the present
invention will become apparent to those skilled in the art as a
better understanding thereof is obtained from the following
description when considered in connection with the accompanying
drawings, wherein:
FIG. 1 is a perspective view, schematically showing the printing
device of the present invention;
FIG. 2 is an enlarged cross-sectional view showing an embodiment of
the recording paper utilized within the present invention;
FIG. 3 is a front view, showing a recording head of the present
invention and the arrangement of its core elements;
FIG. 4 is a side view of the recording head of FIG. 3;
FIG. 5 is a side view, similar to FIG. 4, showing a second
embodiment of the core elements of the recording head;
FIG. 6 is a perspective view, showing another embodiment of the
recording head of the present invention;
FIG. 7 is a side view of the recording head of FIG. 6, showing the
core elements thereof;
FIG. 8 is an enlarged perspective view showing a single core
element useful within the present invention;
FIG. 9 is a perspective view, showing an alphanumeric printing
device of the present invention;
FIG. 10 is a perspective view, showing a recording head and erasing
head used in the alphanumeric printing device of the present
invention;
FIG. 11 is a cross-sectional view, schematically showing the
operation of the erasing head;
FIG. 12 is a perspective view showing another embodiment of the
alphanumeric printing device; and
FIG. 13 is a tabulation, showing the alphanumeric characters which
may be printed by the recording heads shown in FIGS. 3-8.
Referring now to the drawings, FIG. 1 shows the recording paper 10
including a substrate member 12 and field-sensitive web member 14,
sensitive to a force field such as a magnetic or an electrostatic
field. In the preferred embodiment of the present invention the web
member 14 is sensitive to magnetic fields. Further, it will be
understood that the present invention may be practiced without the
substrate member 12 wherein the field-sensitive web member 14 forms
a continuous, self-supporting web. The substrate member 12, when
used, may comprise various materials such as plastic or paper. The
utilization of the substrate member 12 within the present invention
is useful to provide a surface upon which the field-sensitive web
14 may be spread. However, the substrate member is not essential to
the present invention and the present invention may be practiced
without the use thereof.
The field-sensitive web member 14 is formed from transparent
material having tiny fluid-containing chambers 16 in which are
suspended highly reflective flakelike particles 18. In the
preferred embodiment, the chambers 16 are formed by encapsulating
tiny droplets of fluid and particles 18 within individual capsules
which are then coated upon the substrate 12. The flakelike
particles 18 may be formed from paramagnetic or ferromagnetic
materials such as iron, nickel or stainless steel; or from a
combination of both magnetic and nonmagnetic materials such as
nickel-plated aluminum. One of the important features of the
particles 18 is that they are substantially flake-, disk-, plate-,
or leaf-shaped and not acicular. The present invention shall refer
to the particles as flakelike particles, but it is to be understood
that this is a descriptive term and not meant to limit the flat,
broad shape of the material. The recording paper utilized within
the present invention is further described in a copending patent
application by Dale O. Ballinger, Ser. No. 828,993, filed May 29,
1969 and assigned to a common assignee.
In FIG. 1, the recording paper 10 is utilized within an
alphanumeric printing device indicated at 20. The recording paper
10 is unrolled from a supply roll 22 in the direction indicated by
an arrow 24. The paper 10 is drawn under a trisectioned
record/erase head 25, having the central section thereof arranged
to mount a recording head 26. The record/erase head 25 is rotatably
and slidably mounted upon a suitable carriage 28. Selection of the
desired alphanumeric character is accomplished by a
signal-generating keyboard 30 which applies a signal through an
amplifier 32 to the recording head 26. Depending on the
alphanumeric characters selected, predetermined core elements 34,
as shown in FIG. 3, are energized for generating a magnetic field
pattern. For example in FIG. 1, the proper core elements 34 have
been energized to form the letter "A" upon the recording paper
10.
In FIG. 2, the operation of the recording paper 10 is more
completely described. The magnetic field generated by the recording
head 26 perpendicularly reorients the preoriented, highly
reflective flakelike particles 18 within their encapsulating
chambers 16. As described in the copending Ballinger application,
Ser. No. 828,993, the reflective flakelike particles 18 are
preoriented with the plane thereof parallel to the plane of the
recording paper 10 for reflecting incident wavelengths of ambient
light which strike the surface thereof to form a bright reflective
surface thereon. The incident light is indicated at 38, while the
reflected light is indicated at 40. In the area of reorientation
indicated by "T," the reflective flakelike particles 18 cause the
ambient light to be absorbed for forming a dark, contrasting trace
upon the bright background surface of the recording paper 10.
The trisectioned record/erase head 25 includes a pair of erase
heads 42 located on each side of the centrally arranged recording
head 26. If an operator of the present invention were to select an
incorrect alphanumeric character, the error may be corrected by
selecting the next correct character and then depressing an error
key 44 located on the keyboard 30. This causes the trisectioned
record/erase head 26 to backspace and to rotate 90.degree. for
placing the erase heads 42 on each side of the incorrectly selected
alphanumeric character. This rotational motion is achieved by a
signal applied to a control motor 46 from the signal-generating
keyboard 30. This signal also energizes a switching circuit 48
which then senses signals generated by the erase heads 42 as they
move into position over the reoriented areas of the recording paper
10 on each side of the incorrectly selected character. The
generated signals sensed by the erase heads 42 are created in much
the same way a magnetic tape generates a signal within a playback
head as the head moves across the magnetic tape. These signals are
amplified by amplifier 50 and applied to the switching circuit for
establishing which core elements 52 within the erasing heads 42
will be energized to erase the erroneously printed alphanumeric
characters. The switching circuit 48 provides a signal to the
erasing core elements 52 within the erasing head 42 that align
themselves with the correctly printed alphanumeric characters. This
signal generates a flux which passes through the recording medium
for reorienting the reflective flakelike particles 18 into a plane
parallel to the plane of the recording medium. This removes the
erroneously selected alphanumeric character. The trisection
record/erase head 25 is then returned to its operating position and
the correct character is printed upon the recording medium 10. The
erasing operation will be explained in further detail hereinbelow
with reference to FIGS. 10 and 11.
Referring now to FIGS. 3-8, the structure of the recording head 26
will be described. The preferred embodiment of the recording head
consists of 16 core elements 34 including eight arranged on a
rectangular periphery about a second set of eight which radiate
from the center of the rectangle along the diagonals and through
the centers thereof. As shown in FIGS. 4 and 5, each core element
34 is provided with its own coil 54 which is energized by a pair of
input terminals 56. An input signal applied from the amplifier 32
to the input terminals 56 creates a flux within each core element
34 which is utilized to reorient the preoriented magnetic flakelike
particles 18 contained within the recording paper 10. FIG. 5
illustrates a recording head wherein the core elements 34 have been
relieved to receive the coils 54. In FIG. 6, a recording head
encapsulated within a suitable potting compound and arranged with a
height-to-base ratio of 2:3 is shown. Input signal wires 57 are
provided wherein the number required between the input terminals 56
and the core elements 54 may be reduced by utilizing one signal
common wire and 16 signal wires.
In order to generate a flux pattern which is substantially
perpendicular to the plane of the recording medium 10, it is
necessary to provide an air gap 60 for directing the flux into the
recording medium, as shown in FIGS. 7 and 8. In FIG. 7, the core
elements 34 consists of a pair of generally straight core members
58 which are separated by the airgap 60. The coil 54 includes a
pair of coil members 62 wound in opposite directions upon each of
the core members 58. In this manner, a current passing through the
coil members 62 generates an adding flux in opposite direction
within each of the core members 58 which is passed through a back
gap spacer 64 and out of the front airgap 60 as illustrated in FIG.
8. In FIG. 8, an alternate winding method for the coil members 62
is shown. Here, the coil 54 is wound in the shape of a figure-eight
upon the core members 58 for creating two oppositely wound coil
members 62 which generate a flux through the core members 58
forming the core element 34. The flux exits the front surfaces of
the core members 58 around the airgap 60 shown by the arrows
66.
A preferred embodiment of the present invention is illustrated in
FIG. 9 in the form of a typewriter 68. The recording paper 10 may
be inserted as a separate piece of paper, as is well know, or may
be supplied from a supply roll 22, as discussed hereinabove. One
advantage of the present invention is that an operator of the
typewriter 68 may correct a mistake by simply energizing the error
key 44, as briefly described hereinabove. This key causes the
recording head 26 to backspace and rotate 90.degree. for placing
the incorrectly typed alphanumeric character adjacent a central
shield element 70, as shown in FIG. 10. It will be seen that the
trisectioned record/erase head 25 consists of a generally
rectangular solid whose central recording head 26, including core
elements 34, is disposed on one surface and whose erasing heads 42,
including core elements 52, are disposed on a second surface
90.degree. from the recording head.
As the recording paper 10 responds to external magnetic flux for
reorienting the highly reflective flakelike particles 18 contained
therein, any flux pattern utilized to erase an erroneously recorded
alphanumeric character will also create a reorienting effect at the
points where the flux enters and exits the recording paper. Thus,
the procedure of erasing an erroneously typed alphanumeric
character is complicated by the fact that an erasing field will
make undesired erasures on the recording paper 10 unless provisions
are made to prevent or minimize the problem. The present invention
avoids this problem by providing a unique erasing arrangement.
After making an error, the operator types the next correct
alphanumeric character desired before depressing the error key 44.
The record/erase head 25 then backspaces to align the recording
head 26 with the erroneously selected alphanumeric character. Once
aligned, the record/erase head 25 rotates 90.degree. for placing
the erase heads 42 on each side of the switching circuit 48. The
core elements 52 within the erase head sense which portions of the
recording paper 10 has been preoriented and generate a signal
through the amplifier 50 to the switching circuit 48. As the erase
heads complete their rotation and lock into position, the switching
circuit 48 energizes those core elements 54 located over the
previously recorded portions of the recording paper 10 on each side
of the error and applies a signal thereto through an amplifier 72,
FIG. 1. While only one amplifier 72 is shown, it should be
understood that each core element is provided with its own
amplifier and only those core elements sensed by the switching
circuit 48 are energized to generate the erasing signal. This
erasing signal enters the recording paper 10 through the portions
thereof which have been previously reoriented to establish the
desired characters on each side of the error. Thus, the area
through which the erasing flux enters the paper will not be
erroneously marked. The flux signal then passes parallel to the
recording paper 10 for reorienting the magnetic, reflective
flakelike particles 18 contained therein into a plane parallel
thereto. As described hereinabove, this creates a light and bright
reflective background upon the recording medium. After erasure, the
record/erase head 25 is returned to its operating position and the
desired alphanumeric character is printed by the core elements 34
of the recording head 26.
Referring now to FIG. 11, the construction of the erasing heads 42
will be described in greater detail. For example, if an operator
wished to type the word "injoined" and then erroneously typed "im"
in place of "in," the operator continues by typing the "j" and then
depress the error key 44. The record/erase head 25 then backspaces
two spaces and rotates 90.degree., sensing the typed letters "imj"
as it rotates into its erasing position. The switching circuit 48
then energizes the core elements 52 which correspondent to the
vertical core elements utilized to type the letters "i" and "j" on
each side of the erroneous "m." It should be noted here that the
erase heads 42 are not provided with horizontal core elements 52.
The reason for this is that it is desired to generate a flux field
between the erase heads and it is therefore unnecessary to utilize
the horizontal core elements. After the switching circuit 48
selects the proper core element 52 to be energized, the coils 54
associated therewith are energized for generating a magnetic flux
within each core element. All core elements in one erase head 42,
for example the left hand are wound to generate a flux in one
direction while all core elements in the second erase head 42 are
wound to generate a flux in the second direction. A back
flux-conducting bar 74 is provided between each of the erase heads
42. This flux-conducting bar serves to conduct the flux from the
core elements of one erasing head to the core elements of the
second erasing head 42. The flux enters the recording paper 10 in
an area where the desired alphanumeric characters have already been
printed. The flux is then conducted through the recording medium in
a plane parallel thereto for reorienting the magnetic reflective
flakelike particles 18 by the action of the shield element 70.
The shield element 70 is formed from a material having a low
permeability and a high reluctance. This diamagnetic material
causes the flux to be retained within the recording medium 10
between the shield element 70 and a paper cylinder 76 of the
typewriter 68. The paper cylinder 76 is also coated with the
diamagnetic material which may be a layer of bismuth formed from
vacuum-depositing the metal upon a substrate. It will be noted that
the paper cylinder 76 in a prior art typewriter is coated with a
layer of a hard rubber. However, one advantage of the present
invention is that the printing of the alphanumeric characters is
achieved by an impactless arrangement. Therefore, the paper
cylinder 76 may be formed from the metal bismuth without creating a
mechanical problem. Once the erasing process has been accomplished,
the trisection record/erase head 25 is rotated 90.degree. back to
its original position. Shield elements 78, similar to shield 70 are
provided on each side of the recording head 26 to further limit the
flux pattern generated thereby. This serves to protect the
previously recorded alphanumeric characters during the operation of
the recording head 26.
It will be noted by those skilled in the art that the erasing head
just described is limited in its function. For example, if an error
were made in the last letter of a word which forms the last word of
a sentence, the operator would be unable to place an alphanumeric
character opposite the erroneously typed character to provide an
entrance for the flux which is necessary to erase the error. In
this situation, erasing may be accomplished by providing an erasing
head with a wider spacing wherein the operator may place a desired
new character at a greater distance from the erroneously typed
character to provide an entrance for the erasing flux. A second
arrangement for erasing the erroneously typed character is to
return the trisection record/erase head to the beginning of the
line, rotate it to the erasing position, and allow it to sweep the
full line while generating an AC signal within the erase heads 42.
This arrangement provides a flux within the recording paper 10
which reorients the reflective flakelike particles in a plane
parallel to the plane of the recording medium. The reason for this
is that there are apparently very few flux components generated
perpendicular to the recording medium as they tend to be made
smaller and smaller by the AC signal as the erasing heads move
thereacross. This reduces the number of reflective particles 18
oriented perpendicularly to the recording medium for retaining the
highly reflective background surface thereof.
In FIG. 12, a further embodiment of the present invention is shown
wherein the signal generating keyboard 30 is replaced by a computer
80. Generally speaking, a computer will not create printing errors;
and, therefore, the present invention lends itself to full line
printing by establishing a head having a plurality of recording
heads 26 arranged in a side-by-side relationship, one for each
character to be printed upon a line of the recording paper 10. Due
to this, the typewriter 68 is provided without a keyboard or an
erase key. A plurality of recording heads 26 is arranged opposite
the paper cylinder 76 which is controlled by a computer input 82
for rolling the recording paper 10 off the supply roll 22. It will
be observed here that the paper cylinder is the only moving
component within the typewriter 68. The information stored within
the computer 80 is applied over input lines 84 to the typewriter
which selectively energizes the core elements 34 within each
recording head 26 for placing alphanumeric characters upon the
recording paper 10 one line at a time.
Referring now to FIG. 13, a set of alphanumeric characters has been
tabulated to illustrate the alphabet and the numbers 1 to 9 which
may be formed by the recording head 26 of FIG. 6. It should be
noted that all uppercase letters and the numbers may be printed by
the recording head 26 as illustrated in FIG. 6. The majority of the
lowercase letters may also be reproduced by the recording head 26
shown in FIG. 6. However, the lowercase letters "g, j, m, n, p, q,
z, and y" must be typed by shifting the recording head 26 down
one-half space prior to energizing selected core elements 34
thereof. Further, in order to type the lowercase letter "k" it is
necessary to shift the recording head 26 one-half space beyond its
normal spacing sequence. Finally, in order to type the lowercase
letter "x," it is necessary to first energize one lower diagonal
core element 34 of the recording head 26, space the recording head
one-half space, and then energize the second lower diagonal
core.
The alphanumeric characters tabulated in FIG. 12 are representative
of one of several possibilities, and it will be understood by those
skilled in the art that other combinations are possible within the
teachings of the present invention. Further, it will be obvious to
those skilled in the art that the erasing procedures set out
hereinabove is but an illustration of one of many possibilities and
it is not intended to limit the scope of the present invention
simply to the arrangement discussed hereinabove. It will be seen
that the present invention accomplishes the object of providing a
recording medium upon which alphanumeric characters may be printed
and erased therefrom without requiring separate stenographic
equipment. Further, it will also be seen that this erasing
procedure set out herein may be accomplished through a simple
operation which will maintain the neat formal appearance of the
characters being printed upon the recording paper.
* * * * *