Note: Descriptions are shown in the official language in which they were submitted.
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I~rGNET SHEET FOR DISPLAY
BACKGROUND OF TEE INVENTION
1. FIELD OF THE INVENTION
This invention relates to magnet sheets which can be
directly magnetically attached to magnetic surfaces of
steel boards, white boards, etc., and more particularly, to
magnet sheets for display which are capable of printing
print contents thereon using home or business office
printers, such as copiers, laser printers, ink jet
printers, bubble jet printers, ink ribbon type heat-
sensitive printers, dot printers, plotters, etc.
2. PRIOR ART
A magnet sheet, which is made of a material obtained
by adding magnetic particles to a synthetic resin material
and has one surface with alternate N and S magnetic poles
formed by multiple pale magnetization, is sheet-like and
flexible and can be magnetically attached detachably to
magnetic surfaces of steel boards, white boards, etc.
Thus, it can find extensive applications as marks for car
driving beginners, business displays, document binders,
drawing boards, and notices to be attached to magnetic
surfaces.
The marks for car driving beginners and business
displays are produced in a method, in which a white vinyl
chloride sheet or like display sheet is bonded with an
adhesive or the like to a magnet sheet and a desired
display is formed by silk printing or the like on the
display sheet, or a method, in Which a display is printed
in advance on a display sheet and then the display sheet is
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bonded likewise to a magnet sheet. They can be conveniently
attached to surfaces of magnetic members such as steel
boards.
Although displays using magnet sheets as above can be
S conveniently magnetically attached to any magnetic surface,
they are expensive because each of them is prepared by the
above method of bonding a white vinyl chloride sheet or like
display sheet on a magnet sheet and printing a desired.
display content thereon by silk printing which requires a
printing plate for each color or preliminarily printing a
display content on a display sheet using a printer and
bonding this display sheet to a magnet sheet. Besides, the
kind and form of the display are inevitably limited.
Therefore, it is inevitable for general home or offices to
purchase magnet sheets for display, with impressions of
display contents, from specialized shops, or displays have
to be given up when magnetic sheets with desired display
contents are not available.
SUMMARY OF THE INVENTION
In the above circumstances, there has been a demand for
a magnet sheet for display, which permits general home or
offices to readily and quickly form a desired display
content on it and then magnetically attach it to a desired
place without need of purchasing any existing magnetic sheet
available for display.
It is an object of the present invention to obviate or
mitigate the problems associated with conventional magnet
sheet displays.
According to an aspect of the present invention there
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is provided a magnetic display sheet for use with a printer
or copier, the magnetic display sheet comprising a magnet
sheet having a magnetized surface, including alternate N and
S poles formed by multiple pole magnetization, exhibiting a
magnetic force at least ten times as great as the weight of
the magnetic display sheet sufficient to magnetically attach
and hold the magnetic display sheet to the display surface,
and a non-magnetized surface, the magnet sheet having a
thickness in the range of 0.05 to 0.15 mm, a first paper
sheet for being printed on, the first paper sheet having a
thickness in the range of 0.05 to 0.15 mm, the first paper
sheet being bonded to the non-magnetized surface of the
magnet sheet, and a second paper sheet, the second paper
sheet having a thickness in the range of 0.05 to 0.1 mm, the
second paper sheet being bonded to the magnetized surface of
the magnet sheet, wherein the magnetic display sheet has a
thickness in the range of 0.15 to 0.3 mm and can be used for
printing in a printer or copier.
According to another aspect of the present invention
there is provided a magnetic display sheet for use with a
printer or copier, the magnetic display sheet comprising a
magnet sheet having a first magnetized surface, including
alternate N and S poles formed by multiple pole
magnetization, exhibiting a magnetic force at least ten
times as great as the weight of the magnetic display sheet
sufficient to magnetically attach and hold the magnetic
display sheet to the display surface, and a second
magnetized surface, including alternate N and S poles formed
by multiple pole magnetization, exhibiting a magnetic force
at least ten times as great as the weight of the magnetic
display sheet sufficient to magnetically attach and hold the
magnetic display sheet to the display surface, the magnet
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sheet having a thickness of about 0.1 mm, a first paper
sheet for being printed on, the first paper sheet having a
thickness of about 0.1 mm, the first paper sheet being
bonded to the first magnetized surface of the magnet sheet,
and a second paper sheet for being printed on, the second
paper sheet having a thickness of about 0.1 mm, the second
paper sheet being bonded to the second magnetized surface of
the magnet sheet, wherein the magnetic display sheet has a
thickness in the range of 0.15 to 0.3 mm and can be used for
printing in a printer or copier.
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BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a sectional view showing a first embodiment
of the magnet sheet for display according to the invention;
Fig. 2 is a view for describing how a magnet sheet for
display according to the invention is used; and
Fig. 3 is a sectional view showing a second embodiment
of the magnet sheet for display according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Fig. 1 shows a first embodiment of the magnet sheet
for display according to the invention. Referring to the
figure, reference numeral l designates a magnetic sheet for
display. Reference numeral 2 designates a printing sheet
consisting of a paper sheet, such as a high quality paper
sheet or a coated paper sheet, or a synthetic paper sheet
or a synthetic resin film and having a thickness of 0.05 to
0.15 mm. Reference numeral 3 designates a magnet sheet,
which is made sheet-like of a material obtained by adding
magnetic particles to a synthetic resin material and has at
least one surface with alternate N and S poles formed by
multiple pole magnetization. Reference numeral 4
designates an anti-transfer coating of a fluorine type
material or the like formed on the magnetized surface of
the magnet sheet 3.
The printing sheet 2 is suitably selected by taking
the printing means used, purpose of use, cost, etc. into
considerations, and it may be a sheet of cellulose fibers,
an art paper sheet or a coated paper sheet obtained from
the cellulose fiber sheet by coating a surface treatment
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material thereon, a synthetic paper sheet which is a thin
synthetic resin film obtained from a synthetic resin
material by adding white earth thereto or forming
micropores therein, a synthetic resin film, etc. A high
quality paper sheet is suitably used for printing with a
copier, and a coated paper sheet or an art paper sheet is
suitably used for printing an ink jet printer, a bubble jet
printer, etc.
When the thickness of the printing sheet 2 is
excessive, printing with a printer cannot be obtained.
When the printing sheet 2 has an insufficient thickness, on
the other hand, the color (i.e., black color) of the back
side magnet sheet 3 will be seen through it. For these
reasons, the printing sheet 2 suitably has a thickness of
0.05 to 0.15 mm, preferably about 0.1 mm.
The magnet sheet 3 is formed by extrusion molding a
synthetic resin material containing magnetic particles into
a sheet. It has N and S poles formed on one surface by
multiple pole magnetization and alternately arranged at a
constant pitch of 2 to 3 mm. When the thickness of the
magnet sheet 3 is excessive; printing with a home or office
printer cannot be obtained. When the thickness is
insufficient, on the other hand, it is difficult to
maintain sufficient magnetic attraction force and
intensity. For these reasons, the magnet sheet 3 suitably
has a thickness of 0.05 to 0.15 mm, suitably 0.1 mm. This
thickness corresponds to a fraction of the thickness and
weight of commercially available magnet sheets.
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The printing sheet 2 and the non-magnetized surface of
the magnet sheet 3 are bonded together using an acryle
urethane type or like adhesive. The thickness of the
adhesive layer is very small compared to the overall
thickness of the magnet sheet for display, and is
substantially ignorable. Under stringent conditions of its
use such that it is held magnetically attached to a
magnetic surface for long time or is heated in the
magnetically attached state, the magnet sheet may be bonded
to or contaminate the magnetic surface. Therefore, the
anti-transfer coating 4 of a fluorine type or like material
with a small coefficient of friction is provided to a
thickness of several microns to the magnetized surface of
the magnet sheet 3 for prevention thereof from being bonded
to or contaminating the magnetic surface. A magnet sheet
with a thickness of about 0.2 mm is thus completed, and it
is cut to a suitable size and provided as a roll of sheet
having a suitable length.
The thickness of 0.2 mm is substantially the same as
the thickness of a thin name card, and thus the magnetic
sheet l for display according to the invention is capable
of reliably printing using a usual home or office copier or
printer. With the thickness of the magnet sheet 1 for
display set to about 0.2 mm, the magnet sheet 3 can be
magnetized with a magnetizing force, which corresponds to
ten times or above the weight of the magnet sheet 1 for
display. Thus, even when the magnet sheet 1 for display is
magnetized perpendicularly to the magnetic surface, it can
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be reliably held magnetically attached thereto without
possibility of spontaneous fall-down.
Fig. 2 shows how the magnet sheet 1 for display
according to the invention is used. In this case, a
display content 5, such as a graph, is printed on the
printing sheet 2 of the sheet 1, and the sheet 1 is then
magnetically attached to a magnetic surface 6 of a white
board or the like. The magnetic surface 6 may be a white
board, a partitioning member, a locker panel, a cabinet
panel, etc., in a school, an office, etc.
The magnet sheet 1 for display may be used for company
reports and photographs displayed on white boards or the
like, teaching materials displayed on white boards or the
like for school lessons or the like, materials utilized in
conferences, or shop displays. Since the magnet sheet 1
for display is very thin, it can be readily cut like a
paper sheet by using a scissors or a cutter into desired
shapes.
Fig. 3 shows a second embodiment of the magnetic sheet
for display according to the invention. Like the preceding
first embodiment, this magnetic sheet 1 for display
comprises a printing sheet 2 with a thickness of 0.05 to
0.15 mm and a magnet sheet 3 with a thickness of 0.05 to
0.15 mm, these sheets being bonded together. In this
embodiment, however, no anti-transfer coating is provided
on the magnetized surface of the magnet sheet 3. Instead,
a printing sheet 7 of the same material as the printing
sheet 2 and with a thickness of 0.05 to O.l mm, is
laminated on the magnetized surface of the magnet sheet 3
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such that the overall thickness of the magnetic sheet 1 for
display has a thickness of 0.15 to 0.3 mm.
In the previous first embodiment of the magnetic sheet
1 for display, the printing sheet 2 and the magnet sheet 3
which are made of different materials, have different
coefficients of expansion and elongation with changes in
the temperature, relatively humidity, etc. Therefore, when
the magnet sheet 1 for display is cut into small pieces,
each cut piece may be warped or curled. In the second
embodiment, the magnet sheet 3 is sandwiched between the
two printing sheets of the same material, thus eliminating
the elongation/contraction coefficient difference and hence
the curling. Since the magnetized surface side printing
sheet 7 in the second embodiment is not used for printing,
it may be as thin as 0.05 mm so that the ground color of
the magnet sheet can be seen through it.
Although not shown, it is possible to provide a
double-side printable magnet sheet for display by multiple
pole magnetizing both the surfaces of a magnet sheet 3 with
a thickness of about O.i mm and bonding a printing sheet 2
about 0.1 mm thick to each magnetized surface of the magnet
sheet.
As has been described in the foregoing, the magnet
sheet for display according to the invention is
manufactured by molding a material obtained by adding
magnetic particles to a synthetic resin material into a
sheet in the form of a thin film, forming one surface of
the sheet with alternate N and S poles by multiple pole
magnetization, thereby forming a magnet sheet, and bonding
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a printing sheet constituted by a paper sheet such as a
high quality paper sheet or a coated paper sheet or a
synthetic paper sheet or synthetic resin film to the other
surface of the magnet sheet, and it permits quick and ready
printing of a desired display content on it with a usual
home or office printer or copier. The printed magnet sheet
for display can be detachably magnetically attached to a
magnetic surface of a steel board, a white board, etc. The
magnet sheet for display thus permits ready preparation of
displays having desired shapes, such as company reports or
photographs to be displayed on white boards or the like;
teaching materials to be proeided on white boards or the
like for school, lessons or the like, materials used for
conferences, and shop displays.
A different magnet sheet for display according to the
invention is manufactured by molding a material obtained by
adding magnetic particles to a synthetic resin material
into a sheet in the form of a thin film, forming at least
one surface of the sheet with alternate N and S poles by
multiple pole magnetization, thereby forming a magnet
sheet, and bonding a printing sheet in the form of a thin
film constituted by a paper sheet as a high quality paper
sheet or a coated paper sheet or a synthetic paper sheet or
a synthetic resin film to each surface of the magnet sheet.
Thus, while the magnet sheet for display permits printing
on it with a usual home or office printer or copier and
detachably magnetically attaching it to a magnetic surface,
with the magnet sheet sandwiched between the two printing
sheets of the same material it is possible to eliminate
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curling due to the elongation/contraction coefficient
difference between the magnet sheet and the printing sheet.
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