Note: Descriptions are shown in the official language in which they were submitted.
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S P E C I F I C A T I O N
ERASIBbE AND REPRINTABLE PAPER AND INK, AND PRINTING AND
ERASING SYSTEM USING SUCH PAPER AND INK
BACKGROUND OE THE INVENTION
This inYention rela-tes to erasible and reprintable
paper, ink for printing, and printing and erasing sys-tem
using such paper and ink, and more particularly it relates to
printing and/or erasing systems capable of reusing papers or
forms by using such paper or ink.
Recently, the forest resources on the earth are
approachin~ a serious crisis and the exhaustion of forest
resources is now a growing international issue. With the
development of vaious indus-tries, the volume of paper and
paper products consumed at households, institutions and
corporations is far from decreasing, and shows a rapidly
upward -tendency every year. In such circumstance, although -the
need for recYcling of used paper and pa~)er products is loudly
cried for, it encounters big obstacles since i-t requires
assorting works and special treatments for such paper as used
for duplicating machines and facsimile machines because the
paper contains some chemical materials.
~ eamwhile, viewed from the utilization of the paper used
for the duPiicating and facsimile machines, however, in most
cases, the printed papers are stored in files for some -time,
and -then disposed of when desired, The disposal of such paper
requires much time and expensive costs involved because it
requires to keep secrecy of written contents in the paper.
As such, -the development of industries and the up~raded
life of people cause to people consider that the paper is
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disposable artcles. The exhaustion of forest resources is
going on. The increase in carbon dioxide in the atmosphere has
brought a significant, so called, greenhouse effect to the
earth.
In Japan where the volume of paper is consumed the most
or second within advanced countries, the reuse of used paPer
is falling behind, which brings about waste problem which in
turn involves the daily life of people,
~ iewed the aforementioned reuse of paper from prior art
point, the reuse ratio of used paPer is not going upward due
to costs involved. Genarally, used papers are classified at
offices and households and then collected by waste collectors
for reuse, In the procedure of reuse of paper, there are lots
of works to be done and transportation costs involved, in
addition to the costs required to treat inks and chemical
materials contained in special paper. In this manner, the
reuse of used paper does not pay at present. In addition to
the above disadvantages, the qaulity of reproduced PaPer is
significantly bad as compared with that of fresh paper, which
is another factor in delaY in poPulation of the reproduced
paper.
Preservation of forest resouces and protection of
environment of the earth is very important to us. ~or this
very important theme, the reuse of used paper made by
corporations, institutions, and households must be advanced
to minimize the consumption of forest resources, This will be
one~of factors to provide great effects that can be easily
carried out in our daily llfe.
The existing reproduction technology for used paper
requires much burden for users in terms of higher costs
incurred as compared with that of fresh paper in addition to
disadvantages of the inferior quality of the reproduced
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paper, which is a big obstacle for reuse of paper not to be
widely sPreaded among the general Public. Therefore, the
reproduction technology using prior art requires much labor
forces and facilities, which raises the costs of reproduced
paper. Thus, there is no advantage from economical viewpoints.
In the system of prior art, the primary problem is that
classification of various kinds of used papers such as
business forms discharged from office automation equipment or
plain paper must be made by users. SecondlY, it requires
personnel expense and transportation costs for collection of
used PaPer, and the large storage space to store collected
paper before reproduction process is started. In such
situation, therefore, it is difficult to locate the area for
a reproduction plant in the outskirts of a big city.
Purthermore, such a reproduction plant which may use great
amount of chemical materials can bring about environment
pollution in tha-t area.
SU~ARY OF THE IN~ENTION
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It is, -therefore, an object of the invention to provide
an erasible and reprintable forms or papers and ink for use
therewith as well as recording and erasing systems using the
above mentioned paper or ink which is capable of eliminating
the above mentioned disadvantages involved in prior art.
.
In order to accomplish the object of the invention,
there is provided a Paper made from materials interchangeable
into non-visible~visible conditions whereby a pattern Printed
on the paPer can be erased to reuse the paper repeatedlY.
There is also provided a system for printing and/or
erasing a paper made from materials reversibly interchangeable
into non-visible~visible conditions which comprises era~in~
means for changing the pattern printed on the paper from
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visible condition -to non-visible condition and printing means
for changing the pattern printed on the paper from non-visible
condition to visible condition.
There is also provided a printing system for a paper
made from materials reversibly interchangeable into non-
visible/visible conditions which comprises a paPer feeding
mechanism for feeding a paper through a printing position, a
laser source for generating laser beams, and scanning means
for scannig the laser beams impinged on the paper fed through
the printing position.
There is also provided an erasing system for a paper
made from materials reversiblY interchangeable into non-
visible~Yisible condition which comprises a paper feeding
mechanism for feeding a paper through an erasing position, a
laser source for genera-ting laser beams, and scanning means
for scannig the erasing laser beams impinged on the paper fed
through the erasing position,
There is also provied an ink made from materials
reversibly interchangeable into non-visible/visible
conditions
: There is also provided a system for printing and/or
erasing an ink made from materials reversibly interchangeable
into non-visibleJvisible conditions which comprises erasing
means for changin~ the pattern printed on the PaPer from
visible condition to non-visible condition and printing means
for changin~ the pattern Printed on the paper from non-
visible condition to visible condition,
There is also proYided a system for printing and/or
erasing an ink made from materials reversiblY interchangeable
into non-visible/Yisible conditions which comprises ink
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je-ttting means for jetting an ink to the paper and control
means for controlling the jetting of ink in accordance with
the patterns to be printed on the paper.
There is also provided an erasin~ system for an ink made
from materials reversiblY interchangeable into non-
visible/visible condition which comprises a Paper feeding
mechanism for feeding through an erasing position a paper on
which ink is applied to, a laser source for generating a
laser beams, and scanning means for scannig the erasing laser
beams impinged on the paper fed throu8h the erasing position.
~RIEF DESCRIPTION OF THE DRA~IINGS
The present invention will be now described in detail
with reference to the preferred embodiments illustrated in the
accompanying drawings in which:
Fig, 1 is a perspective view of paper made from -the
materials reversibly interchangeable into non-visible/visible
conditions with the parts broken away.
Fig, 2 is a top plan view of an overall configuration of
a printing unit using the paper.
Fig. 3 is a perspective view of a preferred embodiment
of the printing unit.
Fig. ~ is a perspective Yiew of a preferred embodiment
of an erasing unit.
Fig. 5 is a block circuit diagram of the printing unit.
Fig. 6 is a block circuit diagram of the erasin~ unit.
Fig. I is a cross-sec-tional view of the printing uni-t
using ink made from the materials reversibly interchagable
into non-visible/Yisible conditions,
Fig, 8 is a top plan ~iew of an overall con-figuration of
another printing unit.
Fig. 9 is a perspective view of an embodiment of another
erasing unit.
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Fig. 10 is a block circuit diagram of the erasing unit
DESCRIPTION OP THE PREPERRED EMBODIM~NTS
To begin with, the features of papers or forms in
accordance with the invention will be described. The materials
to be mixed with or aPPlied on paper are those reversibly
interchangeable into non-visible~visible conditions. That is,
the materials are changed from non-visible condition into
visible condition and reverselY chan~ed from visible
condition into non-visible condition. Those maY be a single
material or composite materials. Those materials includes a
phase-change material its refraction index of which reversibly
varies in accordance with application of heat thereto (for
example, compound ma-terial which contains either one of
chemical compounds such as chalco~anate compound, antimonY
compound and germanium compound~, and a photochromic material
(spiro-pirane based material and fulgide based material) its
absorbance (achromatic-coloring) of which reversibly varies by
application of the laser beams with different wave-lengths.
The printing paper used in -the presen-t system includes
paper for office use such as paper for duplicating machines
and printers, and reporting paper as well as slips for o-ffice
use and the like.
The provisions of -the material to the paper can be made
by application of -the material onto the paper, the mixing of
the material and the paper material or vaporization of
material onto the paper.
AnY suitahle pattern such as characters, symbols,
figures, or bar-codes can be printed on the paper.
Furthermore, means for printing the patterns on -the
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paper or erasing the patterns printed on the paper includes a
thermal head, a laser-print and laser-beams with different
wave-length. The method using laser-print requires more
expensive devices as compared with that using thermal head.
However, I-t can obtain high resolution printing qaulity
because spot diameter of laser-beams can be focused sharply.
In addi-tinn, durability of -the paper and the printing device
can be greatly improved since non-touch printing can be
carried out in this method.
In erasins operation, erasing time may become longer due
to smaller spot in diameter for the beams. Therefore, it is
preferred that there are provided two laser-beam systems, one
for erasing operation and the other for printing o~eration,
or laser-beams are used for printing operation while a
thermal head is used for erasing operation.
In another approach, the system is divided into an
erasing sec-tion and printing sec-tion, and in the erasing
section, erasing time can be shortened by enlarging the area
on the paper to be swept or making sweeping speed faster.
Preferred embodiments will be now described in detail
with reference to -the drawings. ~or convenience of
explanation, the following description is directed to a
printer for computer in which a laser printer is used in a
printing unit and laser sweeping system is used in an erasing
unit. With insrease in comsumption of Printing paper used for
office automation machines for preparing documents or
drawings, laser printer is now widesPread. Therefore,
combination of the sYStem according to the present invention
and such computer system results in great effec-ts. ?
Referring now to Fig. 1. there is shown a paper 110
whi.ch, in this embodiment, is made by microcaPsulating spiro
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pirane based Photochromic material 112 (hydroxy-
benzorospirane) into microcapsules of 10 micron in diameter
by usual microcapsulating technique, uniformlY mixing the
microcapsules with the adhesive, and applying the resultant
onto plain paper 114. SPiroPirane based photochromic material
has a property that it varies from achromatic condition to
coloring condition when exposed to light of specific
wavelength ~ultroviolet wavelengh region) and reversibly
returns to achromatic condition by heat absorption, that is,
when exposed to white light.
Furthermore, in this embodiment, helium-neon ~wavelengh:
632.8 nm) is used as a laser for printing operation and argon
(wavelengh: 360nm/multi-line) is used as a laser for erasing
operation.
In ~ig. 2, there is shown a Printing unit 2 in
combination of a personal computer 1. In this case, patterns
such as characters, etc. are transferred from the personal
computer 2 to the printing unit 1 in the form of bitmap
information.
In ~ig. 3, there is shown a configuration of the
printing unit 2. The papers 110 made in accordance with the
invention are set in printing paper casing 4 (only location
shown) as in an ordinary manner. In printing operation, the
papers 110 are removed, one at a time, from the paper casing
4 by a removing mechanism 3 and inserted into a printing
mechanism. A paper feed mechanism 5 has a function of feeding
the removed paper at uniform speed, and feed the paper llOa
over a lambda-si-ta lens 11 at uniform speed..
Laser beams emit-ted from a helium-neon laser 7 are
condensed by a condenser lens 8, refracted at right angles
(90 degrees) by a half-mirror 9, and impinged on a light
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modula-tion element 10. A part of inciden-t beams to -the half-
mirror 9 passes through it and reaches to a laser power
sensor 15, which is used -to control the Power of laser at
uniform level. The laser beams are selectively shut and
passed through by the light modulation element 10 in response
to on/off signals supplied thereto from a control circiut 14.
These on/off signals are provided in synchroni~ation with
bi-tmap information received from the personal computer 1.
That is, the laser beams are allowed to pass through only
when the paper comes to the bit position for printing. The
lambda-sita lens has a function of perpendicularly imninging
on the paper the laser beams which is reflected from a
poly~on mirror 12 and swept by rotation thereof by a motor 13.
Thus, the laser beams are impinged on the SPots on the paper
to be printed, and the photochromic material only on the spots
comes to coloring and printing is carried ou-t. Reference
numeral 16 indicates a signal sensor for sYncroniZation.
In ~is. ~, there is shown an erasing unit which erases
pattern printed on the PaPer. When the printed paper 110b is
inserted to cause the printed pattern thereon to be erased, a
pAper feeding mechnism 18 first transfers the paPer over an
image scanner 19 and then transfers it over a lambda-sita lens
20. The image scanner 19 reads the Pattern printed on the
paper, and the read information is stored in a recording
device 23 b~ a con-trol circiut 2~ before erasing is carried
out. Thus, when storage of information is no-t necessarY~ the
image scanner 19 and the recording device 23 can be omitted.
The paper is fed to over the lambda-sita lens 20 after
the pattern is read by the image scanner 19 and recorded by
the recording device 23. At this time, laser beams emitted
from argon laser 25 passes through a condenser lens 26.
refracted at ri~ht angles by a half-mirror 27, and imPinged
onto a polygon mirror 20a in a similar manner to those of the
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aforementioned printing unit. The argon laser beams are
impinged from the polygon mirror 20a through the lambda-sita
lens 20 perpendicularlY on the paper and swept by ro-tation of
the PolYgon mirror 20a driven by a motor 21. The argon laser
beams used for erasing pattern on the paper sweeps the whole
surface o~ the paper, and causes the microcapsulated
photochromic material to change into original achromatic
condition.
In ~ig. 5, there is shown a configuration of the
printing unit described with reference to the ~ig. 3. This
prin-ting unit fundamentally comprises a laser scanning optical
system, a paper feeding system and a system control system,
and in addition to these, an interface for transmitting and
receiving signals between thses systems and a host computer.
A pattern information is transmitted from the host computer 47
through the interface 46 -to a system controller 40 of the
system control system. A mechanism control system 4~ of the
system controller 40 transmits signals to a paper inserting
mechanism 30 of the paper feeding system to feed out the
firæt paper to the paper feeding mechanism 32, which
corresponds to that indicated at 3 in ~:ig. 3.
A PaPer sensor 31 detects the feeding of the paper and
informs -the system controller 40 that the paper is fed
correctly. The paper feeding machanism 32 controls feeding
speed using signals from a paper position sensor 33.
A laser control 42 has a function of keeping the outPut
of the helium-neon laser 34, which cGrresponds to -that
indicated at 7 in ~i~. 3, at specific level, and its output
is always detec.ted bY a laser power sensor 41, which
corresponds to that indicated at 14 in ~ig. 3, and controlled
by a control loop when fluctuated.
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Printing in~ormation output is transmitted as switching
si~nals for laser beams through a bitmap signal processing
circuit 45 to a light modulation elemen-t 35, which correspods
to that indicated a-t 10 in ~ig. 3, The laser beams scan or
sweep the paper through a lambda-sita lens 38. which
corresponds to that indicated at 11 in ~ig. 3, by a polygon
mirror 37, which corresponds to that indicated at 12 in ~ig.
3. At that time, the printing position is adjusted by the
si~nals from a synchronous signal sensor 39, which
corresponds to that indicated at 16 in Pig. 3.
In Fig. 6, there is shown a configuration of the erasing
uni-t described with reference to ~ig. 4. This erasing unit
comprises a paper feeding system, a laser scanning optical
system and a system control system, similar to those of the
aforementioned printing unit. In the erasing unit, there are
provided an image scanner 62, which correspods to that
indicated at 19 in Pig. 4, for reading patterns such sa
characters, and a stora~e device 63, which correspoonds to
that indicated at 23 in ~ig. ~j for storing the data of the
patterns, in place of the interface and the host comPuter
provided in the printing unit,
The paper which has the printed pattern to be erased is
first fed over the image scanner 62 by a paper feeding
mechanism 50, which corresponds to that indicated at 18 in
Pig, 4, At that time, -the patterns printed on -the paper are
read by the ima~e scanner 62 and the infomation thus obtained
is stored in the storage device 63. The output of an erasing
argon laser 52, which correspods to that indicated at 25 in
~ig. 4, is always monitored bY a laser power sensor 58, which
corresponds to that indicated at 28 in ~ig, 4, and controlled
to obtain a predetermined output leYel. The laser beams are
condensed by the condenser lens and scans the paper
perpendicularly by a polygon mirror 54, which corresponds to
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that indicated at 20a in Pig, 4, and a lambda-sita lens 55,
which corresponds to that indicated at 20 in Fig.4. This
causes the photochromic material to be reversibly thermallY
changed into achromatic condition.
Other configurations of the erasing uni-t are
substan-tialy the same as those of the printing unit, and thus
the detailed explanation thereof will be omitted.
The aforementioned embodiments cover the paper made from
the materials reversibly interchangeable in-to non-
visible/visible condi-tions, and the printing and erasing
units using the same. Instead of using the aforementioned
paper, the present invention also can aPply to the ink made
from the materials reversibly interchangeable into non-
visible/visible conditions and, therefore, embodiments of
such an ink and the p~in-ting and erasing units using the same
will be described.
To start with, outlined explanation of ink will be
given. The materials mixed with the ink are those reversibly
interchangeable into non-visible/visible conditions, that is,
substantially -the same materials used ;n the aforementioned
paper.
The pattern and means for erasing the pattern are the
same as those of the aforementioned embodiments, and thus the
detailed explanation thereof will be omitted.
Preferred embodiments will be now described in detail
with reference to the drawings. ~or convenience of
explanation, the following description is directed to a
printer for comPuter in which an ink-jet -type printer is
used. The aforementioned erasin~ unit can be also used in this
embodiment.
In Fig. 7, there is shown an ink jet head for printing
unit using the ink. An impluse-iet system in which the
particles of the ink are ietted by applying instantaneous
pressure with a pie~oelectric element will be shown as an
example. The ink 6~ which is poured into an ink reserYoir 65
is fed to an ink chamber 67 through a tube 66. Pulse voltages
are applied to a piezoelectric elemnt 68 in sYncronization
with the bitmap from the host computer (Big, 8). and the ink
stored in the ink chamber 67 is jetted through nozzle orifice
69 to print the desired pattern on the moYin~ paper.
In Fig. 8, there is sho~n a connection betwwen a
printing unit 71 and a host computer 70. As mentioned above,
the patterns to be printed on the paper is transmitted from
the host computer 70 to the printing unit 71.
In Big. 9, there is shown an erasing unit which erases
the patterns Printed on the paper bY ink. When the Paper on
which ink pattern is to be erased is inserted, a paper
feeding mechanism 73 feeds paper 110b first onto an image
scanner 7~, and then onto a lambda-sita lens 75. The image
scanner 7~ reads the pattern on the paper to be erased, and
the data thus obtained is stored in a storage device 77 by a
control circuit 76 before erasing operation. ~hen storage of
the data is not necessary, the image scanner 7~ and the
storage device 77 can be omitted.
After the data are read by the image scanner 7~ and
stored in the storage device 77, the paper is fed onto the
lambda-sita lens 75, At that time, laser beams emitted from
an argon laser 78 passes through a condenser lens 79, then
reflected right angles by a half mirror 80, and to a polygon
mirror 81. BY a motor 82 which rotates the polygon mirror 81,
the argon laser beams perpendicularly impinges on the paper
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surface for erasing operation. The argon laser beams for
erasing operation sweeps the whole surface of the paper $o
cause -the ink attached on the paper to change into its
original achromatic condition. The reference nuraeral 83
indicates a synchronization sensor and the reference nu~aral
8~ indicates a laser Power sensor.
In Fig. 10. there is shown a configuration of the
erasing unit described with reference to Fig. 9. This erasing
unit comprises a paPer feeding syetem, a laser scanning
optical system and a system control system similar to the
printing unit of Fig. 6. The Erasing unit is provided with an
image scanner 99 ,which corresponds to that indicated at 7~ in
Fig. 9, for reading the patterns and a storage device 100,
which dcorresponds to that indicated at 77 in Fig. 9, for
storing the data thus obtainded.
The paper which has the pattern to be erased is first
fed onto the image scanner 99 by a paper feeding mechanis~ 87.
which corresponds to that indicated at 73 in Pig. 9. At that
time, the patterns printed on the paper is read by the image
scanner 99, and the information data thus obtained is s-tored
in the storage device 100. The output of an erasing argon
laser 89. which corresponds to that indicated at 78 in Pig.
9, is always monitored and controlled to obtain a
predetermined outPut level by a laser power sensor 95, which
corresponds to that indicated at 84 in Fig. 9. The laser beams
are condensed bY the condenser lens and perpendicularly
impinged on the paper surface by a polygon mirror 91. which
correspoonds to that indicated at 81 in Pign 9 and a lambda-
sita lens 92. which corresponds to that indicated at 75 in
Fig. 9, to be scanned, This causes the ink to thermally change
and reversibly return to achromatic condition,
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