U.S. patent application number 14/740731 was filed with the patent office on 2015-10-08 for reusable printing medium and apparatus and method employing the same.
The applicant listed for this patent is Avery Dennison Corporation. Invention is credited to Chia-Hsi CHU, David N. EDWARDS, Adrian J. HULME, Timothy L. PARIS, Haochuan WANG.
Application Number | 20150283587 14/740731 |
Document ID | / |
Family ID | 42061018 |
Filed Date | 2015-10-08 |
United States Patent
Application |
20150283587 |
Kind Code |
A1 |
HULME; Adrian J. ; et
al. |
October 8, 2015 |
Reusable Printing Medium and Apparatus and Method Employing the
Same
Abstract
An erasable and/or reusable image receiving medium (62) is
disclosed along with a system (10) and/or method for using the
same, including a unit (60) and/or method for erasing the reusable
medium (62).
Inventors: |
HULME; Adrian J.; (Mentor,
OH) ; EDWARDS; David N.; (Pasadena, CA) ; CHU;
Chia-Hsi; (Arcadia, CA) ; WANG; Haochuan;
(South Pasadena, CA) ; PARIS; Timothy L.; (van
Nuys, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Avery Dennison Corporation |
Pasadena |
CA |
US |
|
|
Family ID: |
42061018 |
Appl. No.: |
14/740731 |
Filed: |
June 16, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13145234 |
Jul 19, 2011 |
9086669 |
|
|
PCT/US2010/021438 |
Jan 19, 2010 |
|
|
|
14740731 |
|
|
|
|
61145686 |
Jan 19, 2009 |
|
|
|
Current U.S.
Class: |
15/236.01 |
Current CPC
Class: |
B08B 1/005 20130101;
C09D 11/00 20130101; G03G 2215/00518 20130101; B41M 5/5272
20130101; B41M 7/0009 20130101; G03G 2215/00447 20130101; B41M
5/529 20130101; B41N 3/006 20130101; G03G 15/6588 20130101; B41M
5/52 20130101 |
International
Class: |
B08B 1/00 20060101
B08B001/00 |
Claims
1. A device for processing an erasable media, the device
comprising: an erasing station for applying an erasing operation to
an erasable media, the erasing operation removing from the erasable
media at least a portion of a marking agent forming an image on a
surface of the erasable media, the erasing station including: a
support for holding the erasable media; and, an eraser for removing
at least a portion of the marking agent from the erasable media,
wherein the eraser comprises at least one blade that contacts the
surface of the erasable media and mechanically removes the marking
agent therefrom, wherein upon engaging the surface of the erasable
media, the blade applies a desired pressure to the media, wherein
at least one of the eraser, the support and the erasable media are
moved relative to one another so that the eraser is drawn over the
surface of the erasable media while contacting the same to thereby
remove the marking agent from the erasable media, the erasing
station further including collection means that collect the marking
agent removed from the erasable media, wherein the recovered dust
and/or marking agent is deposited in a collection receptacle from
which the recovered dust and/or marking agent can be selectively
recycled or otherwise disposed of.
2. The device of claim 1, wherein the blade has rounded or
turned-up corners along an edge thereof which makes contact with
the surface of the erasable media.
3. The device of claim 1, wherein the eraser contacts the surface
of the media with a controlled pressure, wherein the pressure can
be adjusted via either mechanically or electronically.
4. The device of claim 3, wherein pressure is applied to the eraser
by means of at least one of a motor, a cam, a roller, a lever, a
weight, or a solenoid.
5. The device of claim 1, wherein the eraser can be moved away from
the support.
6. The device of claim 1, wherein the device further comprises a
marking unit that applies marking agent on the media.
7. The device of claim 1, wherein the eraser further includes a
guard to protect against damage to at least one blade by
environmental dust or other objects on the surface of the
media.
8. The device of claim 1, wherein a vibratory motion is applied to
at least one of the media and the eraser.
9. The device of claim 1, wherein the marking agent comprises a
release agent at a weight percent concentration greater than about
1%, wherein the release agent includes at least one of silicone,
fluoro-carbon, organic pre-crosslinked particles or organic thermal
plastic particles with a melting temperature greater than
200.degree. C.
10. The device of claim 1, wherein the device comprises at least
one of the following (i) a pressure sensor that provides feedback
control for adjusting the controlled pressure, (ii) the blade being
spring loaded, and (iii) the blade being sufficiently soft so that
the blade will not damage the media.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a division of U.S. patent
application Ser. No. 13/145,234 filed Jul. 19, 2011, which is a 371
of International Patent Application No. PCT/US2010/021438, which
was published in English on Jul. 22, 2010. International
Application No. PCT/US2010/021438 claims priority from U.S.
Provisional Application No. 61/145,686 filed on Jan. 19, 2009. Said
applications are incorporated herein by reference in their
entireties.
BACKGROUND OF THE INVENTION
[0002] The present inventive subject matter relates generally to
the art of reusable printing mediums and devices and/or methods for
using the same. Particular relevance is found in connection with
xerography and/or electrophotography, and accordingly the present
specification makes specific reference thereto. However, it is to
be appreciated that aspects of the present inventive subject matter
are also equally amenable to other like applications.
[0003] Despite the proliferation of various forms of electronic
and/or digital media, there is still a desire to print or copy or
otherwise output documents and the like on paper and/or other
similar image receiving mediums. That is to say, reading or
otherwise viewing a document (e.g., especially a multi-page
document) on an electronic display or the like may be undesirable
to some users, e.g., due to the limited viewing area or size of the
electronic display. In short, reading and/or viewing documents on
electronic displays and the like can be inconvenient and can tend
to reduce work productivity. The reading and/or viewing of
documents in electronic format (i.e., as opposed to hardcopy
format) also tends to limit the business opportunities for sellers
of toner and/or other like printing supplies. Accordingly, the
desire to print or otherwise output documents and the like onto
paper or other like mediums (e.g., to read or otherwise view the
same) still remains.
[0004] Nevertheless, document storage and/or retention on paper or
other like mediums may often be deemed undesirable, especially when
electronic storage of the documents is readily available. The
desire to read or view documents on paper or another like medium,
while not intending to retain the documents on the paper or other
like medium, can lead to inefficient and/or wasteful use of the
paper or other medium on which the documents are printed or
otherwise output. That is to say, many documents and the like
printed or otherwise output on paper or another like medium
frequently have a relatively limited or short useful lifespan. For
example, many so called hardcopy documents, such as meeting
hand-outs, newspapers and other reading materials, are routinely
disposed of after viewing.
[0005] The aforementioned practice of creating then disposing of
hardcopy documents and the like can tend to incur significant
expense, especially when widely implemented, e.g., within an
organization or other enterprise. In particular, there are often
financial costs incurred for the procurement of the paper or other
medium on which the documents are printed or otherwise output, and
there are also environmental costs typically associated with the
practice. Moreover, these costs tend to be incurred regardless of
whether or not the disposed paper or other like medium is
ultimately recycled. That is to say, even if the disposed paper or
other like medium is recycled, there are costs commonly associated
with the recycling process, e.g., there may be various costs
associated with the collection of the materials to be recycled,
there may be various costs associated with the energy used to power
the recycling plants, etc. Additionally, if private or otherwise
confidential information is output in hardcopy format, there can be
additional costs associated with protecting that information when
the hardcopy is disposed, e.g., such as costs associated with
shedding or otherwise destroying the paper or other like medium
bearing the confidential information.
[0006] Accordingly, a new and/or improved reusable printing medium
is disclosed which addresses the above-referenced problem(s) and/or
other(s), along with a new and/or improved device and/or method for
using the same.
SUMMARY OF THE INVENTION
[0007] In accordance with one embodiment, an erasable and/or
reusable image receiving medium is provided. In particular, the
medium includes: a substrate, and a coating providing an image
receiving surface on the substrate, the coating be configured such
that a marking agent forming an image on the image receiving
surface is able to be selectively removed from the medium in
response to an applied erasing operation.
[0008] In accordance with another embodiment, a system and/or
method is provided for processing the aforementioned
erasable/reusable image receiving media. In particular, a device
for processing the media includes: an erasing station for applying
an erasing operation to the erasable media, the erasing operation
removing from the erasable media at least a portion of a marking
agent forming an image on a surface of the erasable media.
Suitably, the erasing station including: a support for holding the
erasable media; and, an eraser for removing at least a portion of
the marking agent from the erasable media.
[0009] Numerous advantages and benefits of the inventive subject
matter disclosed herein will become apparent to those of ordinary
skill in the art upon reading and understanding the present
specification.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The inventive subject matter disclosed herein may take form
in various components and arrangements of components, and in
various steps and arrangements of steps. The drawings are only for
purposes of illustrating preferred embodiments and are not to be
construed as limiting. Further, it is to be appreciated that the
drawings may not be to scale.
[0011] FIG. 1 is a diagrammatic illustration showing a system in
accordance with aspects of the present inventive subject matter
suitable for use with erasable/reusable image receiving media.
[0012] FIG. 2 is a diagrammatic illustration showing an exemplary
erasing station and/or apparatus in accordance with aspects of the
present inventive subject matter.
[0013] FIGS. 3A and 3B are diagrammatic illustrations showing
exemplary blade type erasers having corners in accordance with
aspects of the present inventive subject matter.
[0014] FIG. 4 is a diagrammatic illustration showing an exemplary
hand-held writing instrument, such as a pen, containing an erasable
marking agent in accordance with aspects of the present inventive
subject matter.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0015] For clarity and simplicity, the present specification shall
refer to structural and/or functional elements, relevant standards
and/or protocols, and other components that are commonly known in
the art without further detailed explanation as to their
configuration or operation except to the extent they have been
modified or altered in accordance with and/or to accommodate the
preferred embodiment(s) presented herein.
[0016] The present specification discloses an erasable and/or
reusable image receiving medium along with a method and/or system
for using the same. As disclosed herein, the aforementioned image
receiving medium is able to receive and sufficiently hold an image
formed thereon, and at a subsequent time, the image can be
selectively removed and/or substantially erased as desired so that
the image receiving medium can be used again. In particular, a
method and/or system is disclosed which digitally prints, copies or
otherwise outputs an image on the erasable/reusable medium. The
image output on the erasable/reusable medium may selectively
include, e.g., any desired graphics, data, information, text,
pictures or other indicia obtained from a suitable image source or
other input. Suitably, the image is formed on the erasable/reusable
medium from toner, ink, or other like marking agents applied
thereto, e.g., by a suitable marking engine (i.e., a printer,
copier, multi-function device (MFD), etc.). For example, the
marking engine may be a laser or other xerographic marking engine,
an ink jet marking engine or the like, a solid-ink marking engine,
etc.
[0017] Removal of an image from the erasable/reusable medium is
suitably accomplished by one or more of a variety of techniques
and/or means. In one suitable embodiment, one or more mechanical
erasure processes are employed to remove the marking agent from the
erasable/reusable medium. Such mechanical erasure processes, e.g.,
include but are not limited to rubbing, scraping, etc. In other
optional embodiments, heat may be applied (e.g., to liquefy or
gasify the marking agent); differential adhesion may be used (e.g.,
to peel the marking agent away from the erasable/reusable medium);
washing may be used; a sacrificial layer may be employed on the
erasable/reusable medium; chemical application (e.g., of solvents
or other constituents) may be employed; UV or other irradiation of
the medium may be used; and other suitable techniques may be
employed to remove or assist in removing the marking agent from the
erasable/reusable medium or at least weaken the bond or adhesion of
the marking agent to the underlying erasable/reusable medium.
[0018] Optionally, the erasing process is carried out by an erasing
station which could or could not be in the same device as a marking
station which incorporates the marking engine. In the former case,
a printer or other device may have at least one media input tray or
the like which receives the reusable media (with or without
markings already thereon). Accordingly, the device will have an
erasing station that ensures that any previous markings will be
erased before printing new markings. Optionally, previous marking
could be erased within a certain time limit after they are inserted
into the tray, e.g., to promote confidentiality and privacy. On the
other hand, the erasing station may be separate from the marking
station. In this case, the printer or other like device would have
at least one media input tray or the like to receive reusable media
without markings. There would also be a special erasing device for
receiving the reusable media, erasing any markings thereon, and
outputting clean erased reusable media. The erased reusable media
could be then transported into the tray of the printer by hand or
by other automatic means.
[0019] The embodiment shown in FIG. 1 includes both a marking
station and an erasing station built in the same device. Suitably,
after erasing and evaluating a reusable media, the media is feed
directly into the marking station. Alternately, in one suitable
embodiment, instead of being fed directly to the marking station,
optionally, the cleaned/erased reusable media may be stored in a
media tray for future printing. In which case, for future marking,
the device will pull sheets from the tray storing cleaned sheets
(i.e., instead of pulling directly from the erase station) unless
the tray of cleaned sheets is detected to be empty. Of course,
other embodiments are also contemplated. For example, one other
embodiment is that the erasing station and the marking station are
built in separate devices. Still another embodiment is that the
erasing station and the marking station are built together but the
erasing and marking is not synchronized in that the erasing station
has its own input and output tray. The marking station then takes
sheets on an as demanded basis from the output tray of the erasing
station. In any event, optionally, the means of detecting and
evaluating the reusable media described below may be employed.
[0020] Optionally, the marking engine includes: one or more marking
stations that apply the marking agent to the erasable/reusable
medium; one or more suitable erasing stations that erase an image
or otherwise remove at least a portion of the marking agent from
the underlying erasable/reusable medium; and/or one or more
suitable surface treatment stations for surface repair, refinishing
and/or resurfacing of the erasable/reusable medium. Alternately,
any one or more of these functions are optionally performed on or
by one or more separate devices.
[0021] Suitably, one or more sensors and/or other evaluation means
and/or techniques are employed (e.g., implemented in a media or
fitness evaluation station) to automatically evaluate sheets of the
erasable/reusable medium to determine their fitness for further
reuse. Optionally, sheets of the erasable/reusable medium deemed
sufficiently fit to warrant further reuse can be forwarded to the
marking station (i.e., for application of another image), while
sheets of the reusable medium deemed sufficiently deficient or
degraded can be rejected and optionally routed away from the
marking station (e.g., where they can be destroyed or disposed of
or otherwise handled as desired). Suitably, selective utilization
and/or bypassing of the surface treatment station can also be
dependent on the evaluated condition of the reusable medium.
[0022] In one suitable embodiment, the marking engine is designed
to apply the marking agent only to sheets of erasable/reusable
medium, in which case, the operational parameters (e.g., fusing
temperature and/or pressure) of the marking station are set
accordingly, e.g., to achieve a desired bonding or adhesion of the
marking agent to the erasable/reusable medium. Alternately,
however, the marking engine is designed to apply a marking agent to
both sheets of standard (i.e., non-erasable/reusable) mediums
(e.g., paper, transparencies, etc.) as well as sheets of
erasable/reusable medium. Accordingly, the operational parameters
of the marking station are optionally varied depending on the type
of medium being used for a particular job. Suitably, separate media
supply trays are provided for sheets of the standard medium and
sheets of the erasable/reusable medium. Optionally, one or more
sensors and/or other detection means and/or techniques (e.g.,
implemented in a media type detection station) are used to
determine and/or designate the type of medium from which a supplied
sheet is made, and the operational parameters of the marking
station are optionally adjusted automatically in accordance
therewith.
[0023] Optionally, one or more sensors and/or other suitable means
and/or techniques (e.g., also implemented via the media and/or
fitness evaluation station or optionally separately implemented)
are also used to determine if a supplied sheet of erasable/reusable
medium has to be erased before it is ready to be marked.
Accordingly, if the supplied sheet has already been erased or is
otherwise sufficiently unmarked, then the erasing station or
erasing operation is optionally bypassed on the sheet's way to the
marking station, otherwise if the supplied sheet has not yet been
erased or is otherwise sufficiently marked, then the erasing
station is utilized and/or activated for that sheet of the
erasable/reusable medium. In this manner, an otherwise already
clean sheet of the erasable/reusable medium is not unduly subjected
to the erasing procedure, thereby promoting an extended lifespan of
the particular sheet of erasable/reusable medium.
[0024] With reference now to FIG. 1, there is illustrated an
exemplary system 10 that is suitable for use with an
erasable/reusable image receiving medium. In essence, the system 10
may be any conventional marking engine (i.e., printer, copier, MFD,
etc.) which is suitably modified and/or otherwise adapted for use
with an erasable/reusable image receiving medium. More
specifically, in the illustrated embodiment, the system 10
includes: [0025] a media supply station 20 from which sheets of
selected media are supplied, e.g., in accordance with the
parameters of a particular print job or other suitable job; [0026]
an optional media type detection station 30 that detects the type
of media supplied thereto (i.e., a supplied sheet is detected
and/or designated as being made from either a standard
non-erasable/reusable medium or an erasable/reusable medium);
[0027] a media and/or fitness evaluation station 40 that detects
and/or otherwise determines, e.g., at least one of (i) whether or
not a supplied sheet of the erasable/reusable media is fit for
reuse, (ii) whether or not a supplied sheet of the
erasable/reusable media has to be erased before being reused or
otherwise marked, and/or (iii) whether or not a supplied sheet of
the erasable/reusable media is to be sent to an optional surface
treatment station 50 for optional surface repair, refinishing
and/or resurfacing of the media; [0028] the aforementioned optional
surface treatment station 50 that is optionally utilized to (i)
repair and/or refinish a damaged or degraded image receiving
surface of the erasable/reusable medium and/or (ii) apply an
optional sacrificial layer to the image receiving surface of the
erasable/reusable medium; [0029] an erasing station 60 that
selectively removes at least a portion of an image forming marking
agent from the erasable/reusable medium; [0030] a marking station
70 that selectively applies at least one marking agent (e.g.,
toner, ink, etc.) on the supplied medium to form an image (e.g.,
including graphics, pictures, text, data, information or other
indicia) thereon; [0031] an optional finishing station 80 that
applies finishing processes and/or operations (e.g., such as
folding, stapling, cutting, hole punching, binding, etc.) to jobs
in accordance with selected job parameters; [0032] an optional
output tray 90 that receives a finished job; [0033] an optional
media destruction station and/or disposal tray 100 that destroys
and/or otherwise receives rejected sheets of media; [0034] an image
input source 110 that provides image data to the marking station
70; and, [0035] an optional user interface (UI) 120 by which a user
can select various job parameters and/or otherwise control selected
operations of the system 10.
[0036] In the illustrated embodiment of FIG. 1, the system 10 is
suitably configured to accept both a standard type of image
receiving medium (i.e., non-erasable/reusable) and an
erasable/reusable image receiving medium as disclosed herein.
Optionally, separate trays (i.e., nominally labeled trays 1 and 2)
are provided in the media supply station 20 to hold respectively
sheets of the different media types. For example, as shown, tray 1
is optionally loaded with and/or otherwise holds only sheets of the
standard media type, while tray 2 is optionally loaded with and/or
otherwise holds only sheets of the erasable/reusable media type.
Accordingly, when a job calls for standard media, the media supply
station 20 optionally outputs one or more sheets (as demanded by
the job) from tray 1. In this case, the standard sheets of media
supplied by the media supply station 20 can optionally bypass
otherwise intervening stations relevant to erasable/reusable medium
and proceed directly to the marking station 70. Conversely, when a
job calls for erasable/reusable media, the media supply station 20
optionally outputs one or more sheets (as demanded by the job) from
tray 2. In this case, the erasable/reusable sheets of media undergo
selective processing by one or more of the intervening stations
relevant to the erasable/reusable media before proceeding to the
marking station 70 or other final destination as the case may
be.
[0037] In one suitable embodiment, a given tray of the media supply
station 20 (e.g., tray 3 in the illustrated embodiment) may be
loaded with and/or otherwise hold both types of media, either
simultaneously or at alternate times. In this case, sheets supplied
from a combined media tray (such as tray 3) can first be routed to
the media type detection station 30 that employs one or more
sensors and/or other detection means and/or techniques to determine
and/or designate the type of medium from which a supplied sheet is
made. If the detected media type is appropriate for the current job
being run, then as the case may be the respective sheet is forward
to and/or processed by the next appropriate station--i.e., standard
sheets of media can optionally bypass otherwise intervening
stations relevant to erasable/reusable medium and proceed directly
to the marking station 70, while erasable/reusable sheets of media
are forwarded to and/or undergo selective processing by one or more
of the intervening stations relevant to the erasable/reusable media
before proceeding to the marking station 70 or their other final
destination. Conversely, if the detected media type is not
appropriate for the current job being run, then the sheet is
optionally returned to the media supply station 20. Optionally,
sheets detected to be of the wrong media type may be returned to
the same supply tray from which they originated or alternately to
another tray designated for and/or matching the detected media type
of the particular sheet in question. Alternately, sheets detected
to be of the wrong media type may be forwarded to the media
disposal station 100 (e.g., where they can be collected and
optionally reloaded manually into the media supply station 20). In
any event, if the wrong media type for a job is detected by the
media type detection station 30, the job may optionally be halted
or suspended and the user optionally notified (e.g., via the UI
120) of the fault condition. In one suitable embodiment, the media
supply station 20 may make one or more additional attempts to
provide the appropriate media type for the job before job
suspension and/or indication of a fault condition. Additional
attempts may optionally be made from the same or different supply
trays until the appropriate media type is detected or some set or
otherwise determined attempt limit is reached.
[0038] Suitably, tray and/or media selection data for a given job
is provided to the media supply station 20 via the UI 120 or
alternately it is provided (e.g., along with other job parameters)
from a computer or the like operatively communicating with the
system 10 and/or submitting the job. Tray and/or media selection
data may optionally identify a specified tray from which sheets of
media are to be selected (in which case the media supply station 20
simply complies), or alternately, it may identify a specific media
type which is desired for the job (in which case the media supply
station 20 optionally selects a particular tray designated for the
identified media type). In the later case, if no tray is
specifically designated for the desired media type selected in
connection with a given job, then optionally sheets of media from
different trays are sampled and submitted to the media type
detection station 30 to determine which (if any) tray is holding
the desired media type for the job being run.
[0039] In the illustrated embodiment, the system 10 is configured
to accept both media types (i.e., standard and erasable/reusable).
Accordingly, the marking station 70 is optionally provisioned with
selectively variable operating parameters to accommodate both media
types. For example, in one optional embodiment the marking station
70 may include a xerographic marking engine in which parameters
such as fusing temperature and/or pressure are optionally set to a
first combination of determined values when standard media is
selected (i.e., for non-erasable/reusable media jobs) and a second
different combination of determined values when erasable/reusable
media is selected (i.e., for erasable/reusable media jobs). In this
regard, it is to be appreciated that by employing selectively
variable operating parameters for the marking station 70, the
degree to which the marking agent bonds or adheres to the
underlying media can be controlled or regulated to some extent.
Accordingly, for erasable/reusable jobs, it may be desirable for
the bond or adhesion between the marking agent and media to be
relatively weaker as compared to non-erasable/reusable jobs.
[0040] Suitably, the operating parameters of the marking station 70
are selected and/or set based on the media selection for a
particular job. For example, operating parameters (such as fusing
temperature and/or pressure) of the marking station 70 may
optionally be controlled in response to media selection data
obtained from the UI 120 or obtained along with other data
submitted with the job from a computer operatively connected and/or
communicating with the system 10 or in response to a media type
determination made by the media type detection station 30.
[0041] Presuming erasable or reusable media is selected for a job
from the media supply station 20, suitably the media is forwarded
to a media and/or fitness evaluation station 40. Via suitable
sensors or other detecting means and/or techniques employed to
conduct observations and/or evaluations of the media, the
evaluation station 40 optionally determines based upon those
observations and/or evaluation of the media which (if any) further
processing operations are to be performed on the media (e.g., prior
to marking or forwarding to another ultimate destination). For
example, the evaluation station 40 suitably determines at least one
of the follow: [0042] whether or not a sheet of the
erasable/reusable medium is fit or unfit for further reuse; [0043]
whether or not a sheet of the erasable/reusable medium should be
erased before receiving further marking; and/or [0044] whether or
not it is appropriate for a sheet of the erasable/reusable medium
to have surface repairs and/or refinishing performed thereon or
have a sacrificial layer applied thereto.
[0045] While the erasable/reusable medium is intended to be used
repeatedly, it is nevertheless generally a consequence that after
some number of repeat uses a sheet of the medium may become damaged
or degraded to some degree, e.g., as the result of repeated erasing
operations and/or other repeated handling. If sufficiently damaged
or degraded, the evaluation station 40 optionally determines that a
sheet is unfit for further use, and optionally forwards the sheet
in question to the media destruction station and/or disposal tray
100. Conversely, if significant damage or degradation is not
detected, the sheet may be deemed fit for further reuse.
[0046] In one suitable embodiment, the evaluation station 40 is
provisioned with sensors or other suitable means to observe and/or
evaluate the physical characteristics and/or property of a sheet to
determine fitness. For example, the sensors may be employed to
optionally inspect the sheet for tears, scratches, surface defects,
etc. Accordingly, depending upon the amount and/or extent of
detected wear indicators such as these, the sheet is deemed either
fit or unfit for further reuse and accordingly forwarded to
subsequent stations as appropriate for the given result. For
example, fit sheets of media may ultimately be advanced to the
marking station 70 while unfit sheets of media can be sent to the
media destruction station and/or disposal tray 100.
[0047] In an alternate embodiment, the evaluation station 40 is
optionally configured to track the number of times a particular
sheet of erasable/reusable media has been used. Consequently, if it
is determined that the sheet in question has already been used over
some threshold number of times, then it can be deemed to no longer
be fit for further reuse, otherwise if it is determined that the
sheet in question has not been used more than the threshold number
of times, then it can be deemed fit for at least one further use.
Optionally, in order to track the number of times a particular
erasable/reusable sheet has been used, each sheet is provided with
an indicator that communicates the same to the evaluation station
40. Suitably, the indicator may be relatively inconspicuous upon
casual observation of the sheet of media and/or does not interfere
with or obscure images ultimately formed on the medium. For
example, the indicator may comprise markings or indicia placed in
unobtrusive locations on the media, e.g., in the margins or on the
back surface or edge of the media. The markings may be small in
size and/or light in intensity to further promote their
inconspicuous nature. Optionally, the markings may be made with a
toner, ink or other marking agent that is largely invisible under
normal lighting conditions but may be visible under a particular
spectrum of radiation, e.g., such as UV or Infrared (IR). In any
event, optionally, the marking station 70 applies the appropriate
marking or indicia each time an erasable/reusable sheet of media is
passed therethrough or otherwise used. In this way, the applied
markings or indicia serve as an incremental counter and/or
otherwise reflect the number of uses that sheet of media has
experienced. Of course, in this case, the evaluation station 40 is
optionally equipped or otherwise provisioned to observe or read and
interpret these markings and/or indicia. Suitably, the use
indicating marking or indicia contained in or on a sheet of
erasable/reusable media are not removed therefrom by erasing
operations, e.g., such as those executed by the erasing station
60.
[0048] Alternately, the erasable/reusable medium may be provisioned
with a Radio Frequency IDentification (RFID) tag or other like
device which records the number of uses. In this embodiment,
suitably, the marking station 70 or other suitable station is
equipped and/or otherwise provisioned to write use data to the RFID
device and the evaluation station 40 is provisioned with an RFID
reader or the like to read the use data from the RFID device.
Suitably, the RFID writer may simply increment a counter on the
RFID device each time the sheet is used.
[0049] In one suitable embodiment, if an erasable/reusable sheet is
deemed unfit by the evaluation station 40 for further or additional
reuse, then optionally the sheet in question is routed to the media
destruction station and/or disposal tray 100. Optionally, when
forwarded to the station or tray 100 the media is destroyed. For
example, the station 100 is optionally equipped with a shredder or
the like that shreds or otherwise destroys the received media. In
this manner, additional reuse is further precluded and/or
potentially sensitive information on the disposed media is
protected. In another effort to protect potentially sensitive
information on disposed of media, optionally sheets are first
routed to the erasing station 60 for erasure prior to being
received at the media destruction station or disposal tray 100.
[0050] As can be appreciate, a sheet of erasable/reusable media may
not always have to be erased prior to its use. For example, the
first time such a sheet is used it generally will not have any
image printed or otherwise formed thereon, or a sheet may have been
previous erased, e.g., by an outside device or process.
Accordingly, subjecting the otherwise blank sheet to an erasing
operation may unduly wear the sheet when erasing is generally not
demanded. Consequently, the evaluation station 40 optionally also
performs a check on the sheet to determine if in fact erasing is
appropriate before further reuse of the sheet. To this end, the
evaluation station 40 is suitably equipped or otherwise provisioned
with sensors or other means and/or techniques by which observations
and/or evaluations of the sheet are carried out from which a
determination can be made whether or not to subject the sheet to
erasing. Suitably, such observations and/or evaluations determine
whether or not a sheet is sufficiently blank or free of marking
agent. Accordingly, a sheet that is sufficiently blank or free of
marking agent can forego erasing operations (e.g., by bypassing the
erasing station 60 before proceeding to the marking station 70),
while a sheet that in not blank or that has greater than a
threshold level of marking agent thereon is subjected to the
operation of the erasing station 60 prior to being forwarded to the
marking station 70. In one suitable example, a scanner provided in
the evaluation station 40 may obtain a digital or other
representation of the sheet in question or otherwise scan the sheet
in question. Accordingly, each pixel or other like unit in the
scanned representation having an intensity value over a determined
threshold can then be deemed as marked, and if the number of marked
pixels exceeds a given threshold, then the sheet can be deemed as
not blank, otherwise if the number of marked pixels is below the
threshold, then the sheet can be deemed as sufficiently blank.
Alternately, an average, mean, median or other statistical analysis
of the scanned intensity levels can be used to determine whether or
not the sheet is sufficiently blank.
[0051] In one embodiment, the system 10 optionally includes a
surface repair or refinishing station 50. At this station,
optionally one or more of the following processes or operation are
executed:
[0052] repairing and/or refinishing a damaged or degraded image
receiving surface of the erasable/reusable medium; and/or [0053]
applying an optional sacrificial layer to the image receiving
surface of the erasable/reusable medium.
[0054] When the system 10 is configured with the station 50,
optionally, the media evaluation station 30 may decide that while a
sheet may be somewhat damaged or degraded to a less than desirable
degree, it may still be salvageable with appropriate resurfacing or
surface repair, and accordingly, the sheet is routed to the station
50 for this resurfacing or surface repair. Alternately, when a
sacrificial layer is employed on the erasable/reusable medium, the
sheet may also be routed to the station 50 to receive this layer.
The resurfacing operation may involve mechanical, heat, chemical
and/or other appropriate treatments to restore or rejuvenate the
image receiving surface and/or layer of the erasable/reusable
medium. In another optional embodiment, the resurfacing operation
and/or provision of a sacrificial layer may optionally be performed
by the station 50 via application of a suitable film or other
material or other layer on the image receiving surface or side of
the media. Optionally, remnants of the old image receiving surface
or layer are first removed by the station 50 to expose a
substantially clean underlying substrate or carried layer. As
appropriate, the underlying substrate can be treated or otherwise
suitably prepared by the station 50 in order to achieve a desired
bond and/or adhesion or other junction with the newly applied image
receiving surface and/or sacrificial layer. Upon completion of
selected operations by the station 50, optionally the media is
returned to the evaluation station 40 to confirm sufficient fitness
for further use has been achieved. Alternately, achievement of the
desired fitness for further reuse may be assumed and the media may
simply be advanced to the marking station 70.
[0055] The erasing station 60, as the name implies, is where the
erasable/reusable medium is erased, i.e., where at least a portion
of the marking agent (e.g., toner, ink, etc.) forming an image on
the erasable/reusable medium is removed therefrom. Depending on a
number of factors, e.g., including the type of marking agent, the
construction of the erasable/reusable medium in question, and the
degree of bonding and/or adhesion between the two, one or more
various operations and/or processes are optionally employed by the
erasing station 60 to achieve the desired goal. In one suitable
embodiment, one or more mechanical erasure processes are employed
to remove the marking agent from the erasable/reusable medium. Such
mechanical erasure processes, e.g., include but are not limited to
rubbing, scraping, etc. In other optional embodiments, heat may be
applied (e.g., to liquefy or gasify the marking agent);
differential adhesion may be used (e.g., to peel the marking agent
away from the erasable/reusable medium); washing may be used; a
sacrificial layer may be employed on the erasable/reusable medium;
chemical application (e.g., of solvents or other constituents) may
be employed; UV or other irradiation of the medium may be used; and
other suitable techniques may be employed to remove or assist in
removing the marking agent from the erasable/reusable medium or at
least weaken the bond or adhesion of the marking agent to the
underlying erasable/reusable medium. Specific examples for
achieving erasure will be discussed in greater detail below.
[0056] Suitably, after the erasing station 60 has performed its
erasing operation(s), the sheet is optionally retuned to the
evaluation station 40 to confirm that sufficiently successful
erasure has been achieved and that the sheet is still sufficiently
fit for further reuse. In one suitable embodiment, if surface
repair or refinishing is desired or if application of a sacrificial
layer is to be performed, then the sheet may optionally be routed
from the erasing station 60 to station 50. Alternately, if
resurfacing and/or application of a sacrificial layer is not being
performed, upon completion of the erasing process by the erasing
station 60, sufficiently successful erasure without significant
further degradation to the medium can optionally be assumed and the
sheet forwarded on, e.g., to the marking station 70.
[0057] Once a sufficiently fit and/or sufficiently blank sheet of
the erasable/reusable medium has been achieved, it is optionally
forwarded, advanced or otherwise submitted to the marking station
70. The marking station 70 applies marking agents (i.e., toner,
ink, etc.) to the received media to form an image thereon in
accordance with received image data from an image source 110. For
example, the image source may be a scanner or a computer or the
like operatively connected to and/or in communication with the
system 10 for submitting a print or copy or facsimile or other like
job thereto. Optionally, the marking station 70 may be implemented
via any suitable xerographic marking engine. As mentioned earlier,
the variable operating parameters (e.g., such as the fusing
temperature and/or pressure) of the marking station 70 are
optionally controlled based on the selected and/or detected media
type.
[0058] Optionally, the system 10 also includes a finishing station
80. Suitably, sheets of media a received at the finishing station
80 from the marking station 70 after image forming the marking
agent has been applied. The finishing station 80 is optionally
equipped and/or otherwise provisioned to perform any number of
conventional finishing operations (e.g., such as folding, stapling,
cutting, hole punching, binding, etc.) in accordance with job
parameters. Suitably, desired finishing options to be performed by
station 80 are optionally selected via the UI 120 or alternately
they accompany other job data received, e.g., from a computer or
the like operatively connected to and/or in communication with the
system 10 for submitting a print or copy or facsimile or other like
job thereto. Once the finishing station 80 has completed its
operations, optionally the completed document or job is deposited
in the output tray 90, e.g., so as to be ready for convenient
collection by the user.
[0059] The imaging method in accordance with at least one
embodiment of the present inventive subject matter is xerography
(or electrophotography). As is understood in the art, xerography is
widely used in photocopying machines and in laser and LED (light
emitting diode) printers. Generally, in xerography, an electrical
charge is used to pattern a marking agent (namely toner particles),
and then a heat transfer process is used to adhere/fuse the toner
onto a receiving media. Commonly, the toner is made of organic
resin, colorant such as pigment or dyes, etc. The organic resins
are mainly low molecular weight resins that have glass transition
or melting temperatures above room temperature. Upon heating the
toner flows onto the surface of the receiving media; and upon
cooling the toner binds and adheres to the surface of the
media.
[0060] The adhesion mainly depends on the formulation of the toner
as well as the composition and structure of the receiving surface
of the media to which the toner is applied. The adhesion also
generally depends on the fusion temperature and pressure at which
the toner was applied to the image receiving medium. Generally, a
low enough fuser temperature will cause the toner to only partially
melt and thus have less adhesion strength on the media. Likewise, a
low enough pressure or even no-pressure will generally cause the
toner to have less surface contact with the media and thus have a
relatively lower adhesion strength.
[0061] The following table shows factors that affect the adhesion
between the toner and media to which it is applied. In general,
good adhesion allows the printing or marking (e.g., the toner image
on the media) to be more durable (i.e., survive more harsh usage),
which is a generally desired property. Poor adhesion, on the other
hand, allows the printing or marking to be easily removed, e.g., by
mechanical ways, which is a generally desired property for erasable
applications. As can be appreciated, the desirable features of good
erasability and good durability impart contradicting demands with
respect to toner adhesion. Suitably, a good balance is found to
obtain acceptable durability for temporary printing/marking and
easy mechanical or other erasure with minimal damage to the media.
Advantageously, this well balanced adhesion is also maintained
largely consistent during the life-cycle of the media.
TABLE-US-00001 Factors Effects to the Adhesion Toner Composition By
appropriate selection of the toner composition, adhesion of the
toner can be controlled. Print Media Surface By appropriate
selection of the media's surface chemistry or surface structure,
adhesion of the toner can be controlled. Fusing Temperature By
appropriate control of the fusing temperature, adhesion of the
toner can be adjusted as desired (e.g., lowering the fusing
temperature can diminish adhesion). Fusing Pressure By appropriate
control of the fusing pressure, adhesion of the toner can be
adjusted as desired (e.g., lowering the fusing pressure can
diminish adhesion). Some physical or For example, tension,
expansion and/or stress on the chemical treatments media can cause
delamination of the toner from the media surface. Corona, plasma
and/or radiation treatment can breakdown organic binder components
in the toner so that the toner adhesion can be reduced. Temperature
drops below room temperature can cause the toner resin to be more
glassy and brittle so that it is easier to erase mechanically
(e.g., such as by abrasion).
[0062] In accordance with the experience and/or experimentation of
the inventors, a well balanced toner adhesion has been achieved
which exhibits the following features: 1) the toner can be fused
onto the media surface with good image quality; 2) the image fused
on the media has a certain desirable degree of abrasion resistant
such that normal finger and/or paper rubbing will not remove toner
from the media; and, 3) the adhesion of toner to the media surface
is not too strong so that a relatively simple mechanical operation
(e.g., such as finger nail scratch, a scratch by a sharp object, a
scratch under high pressure, etc.) can remove the toner.
[0063] As previously described, a printer or other marking engine
is disclosed herein that is able to selectively apply various
operating parameters. In particular, disclosed herein is a printer
or marking engine that is capable of operating at a sufficiently
low fusing temperature and/or sufficiently low fusing pressure so
that a correspondingly lower degree of fusion of the toner onto the
media can be achieved, thereby promoting the ability to
substantially remove toner cleanly from the media via mechanical
means and/or operations. Optionally, the printer or marking engine
can operate while applying either "normal" fusing temperature
and/or pressure or reduced fusing temperature and/or pressure.
Therefore, the printer or marking engine can be used for both
"permanent" applications and removable applications. That is to
say, for permanent printing/marking jobs, the normal fusing
temperature and/or pressure will be used, and for erasable or
temporary printing/marking jobs, the reduced fusing temperature
and/or pressure can be used.
[0064] Optionally, the printer or marking engine can be dedicated
to only printing erasable/reusable media (e.g., as described in
this specification). Alternately, the printer or marking engine can
use both erasable/reusable media and common media (e.g., such as
paper, transparency, etc.). In the latter case, the printer or
marking engine can have at least one tray dedicated for
erasable/reusable media and at least one tray dedicated for the
common or standard media. Additionally, as already described above,
the printer can have a build in mechanism or station for erasing
the reusable paper or a machine separate from the printer or
marking engine can be used for erasing the reusable media.
[0065] As is generally known in the art, conventional toners can
contain dyes. Moreover, it has been observed that after
printing/marking on the erasable/reusable medium in accordance with
the present method, a dye sublimation effect can be experienced,
e.g., due to the high temperature of the fusing process. In
particular, low molecular weight organic dyes have exhibited this
dye sublimation effect. In this effect, the dye molecule sublimes
from a solid to a gas which then penetrates into the media fiber or
resin. After penetrating into the media, it essentially becomes
part of the media and can not easily be removed mechanically. In
experiments with an HP Color Laser Jet CP1215, the yellow color has
exhibited the dye sublimation effect, and after a mechanical
erasing process, a slight yellow color ghost image remains visible,
e.g., on a white PET (polyethylene terephthalate) based media.
Accordingly, to overcome such an issue, it is advantageous that the
employed marking agent or toner have colorants that do not contain
dyes that are susceptible to the sublimation effect. In this
regard, e.g., inorganic pigments can be used, or organic pigments
may be used that mainly contain large molecular weight dye(s) or
dye molecules anchored on some macromolecular structure.
Alternately, the sublimation effect can also be reduced by
employing a lower fusing temperature. For most conventional dyes,
the sublimation temperature is above 150.degree. C. Accordingly, if
the fusing temperature is kept below 150.degree. C., the
sublimation effect can be adequately reduced.
[0066] Optionally, toner removed during the erasing process is
recovered so that is may be reused and/or recycled. The erasing
process proposed herein (discussed in greater detail below)
suitably abrades or scrapes the toner off the erasable/reusable
media. Optionally, the removed toner dust is then collected, such
as, in a vacuum filter. Suitably, the toner from the vacuum filter
can be collected, and for example, sent back to toner vendors or
the like so that the used toner can be regenerated. This is
especially useful for black-and-white or monochromatic applications
where inter-mixing of different toner colors is not an issue. One
known technology of making commercial toner is grinding chunks of
color resin into a micrometer size powder. Suitably, such a process
may be employed on the recycled toner dust to convert the same back
into useful toner powder. Alternately, the toner can be
biodegradable. For example, the toner may optionally contain resins
that are biodegradable themselves or some additives can be applied
to make the resins biodegradable.
[0067] In accordance with aspects of at least one embodiment of the
present inventive subject mater, suitably, the erasable/reusable
media comprises at least one from the following: a film, a paper, a
paper-film-combination, etc. Optionally, a coating can be applied
on the image receiving surface or side of the media. In case paper
is used as part of the media, the paper is optionally coated and
sized with polymeric resin or laminated with plastics. In
accordance with embodiments of the present inventive subject
matter, typical sizing and sealing coatings on paper may include
water based, UV based, solvent based, or solvent-less coatings. For
example, a water based coating may typically comprise emulsions or
dispersions that have polymers that may contain acrylics, urethane,
polyester, vinyl polymer, polyolefin, silicone, etc. The paper
surface can also be extrusion coated or laminated with a layer of
plastic. The plastic layer can be joined to the paper layer with or
without the help of an adhesive. Plastics which can be used for
this purpose include polyolefins (PE (polyethylene), PP
(polypropylene), TPX (polymethylpentene), etc.), polyesters (PET,
PETG (polyethylene terephthalate glycol), etc.), polycarbonate,
acrylic, urethane, etc.
[0068] Suitably, at least one surface of the media is constructed
and/or otherwise configured to allow the toner or other marking
agent to be repetitively applied and erased. For erasable
applications, the image receiving surface of the media is
advantageously non-absorbing. In this context, the term
non-absorbing is meant to describe a surface that does not have a
significantly porous structure, so that toner or other marking
agents can not significantly penetrate into the media. However, the
media surface can appear to be either smooth (i.e., glossy) or matt
(based on the common perception of media, such as glossy photo
paper or matt photo paper). Nevertheless, smooth or glossy media
may be somewhat more advantages insomuch as it may tend to be
easier to clean completely. As is known in the film industry,
certain techniques can optionally be used to make a super smooth
plastic film surface such as calendering, planarization, sanding,
polishing, etc. In one suitable embodiment, where a coating is
applied onto a plastic film carrier to serve as the image receiving
surface of the media, use of a plastic film carrier with high
surface smoothness can help the coating to form a smooth
surface.
[0069] In studies conducted using an HP laser printer with HP toner
and mechanical erasing such as scraping, rubbing, abrasion, etc.,
it has been found that the following properties are significant for
achieving a good reusable application in accordance with at least
one embodiment: 1) the toner should be able to print or mark on the
media with good image quality; 2) the toner should adhere to the
media with enough strength so that normal finger rubbing, or office
use will not erase it off; 3) the toner should be able to be erased
by abrasion or other mechanical means or operations; 4) the media
itself should be able to tolerate repetitive erasures. Optionally,
the first property can be tested by conventional or other image
analysis after xerographic imaging. The second and third properties
are related to adhesion/anchorage of the toner to the image
receiving surface of the media. Of course, the adhesion anchorage
can be tested. One direct measurement of toner anchorage is
abrasion testing. Under abrasion at low pressure and/or slow speed
and/or by soft materials, the toner should stay on the print media
surface. Under abrasion at high pressure and/or high speed and/or
by sharp and/or hard materials, the toner should be abraded off.
Simple devices to measure the abrasion values include a Taber
tester, Crockmeter, etc.
[0070] Having the last property (abrasion resistance) is
significant so that the media or media surface can tolerate the
mechanical abrasion during the erasing operation and still provide
a good surface for the next use. Nevertheless, it is expected that
some surface material may be removed during erasure operations.
Suitably, such "rub-off" is minimal so that the same surface
chemistry can prevail for at least some number of erases so that
acceptable printing/marking and erase performance can last during
the usable life time of the printable media (e.g., say, at least 10
erases). To this end, there are at least two ways to improve the
media's abrasion resistance. One is to improve the hardness of the
media's surface material, and the other is to lower the surface
friction of the media's surface material.
[0071] In embodiments where the toner used tends to have good
adhesion to most common plastic surfaces, the surface of the media
is optionally made special so that the toner can be removable. It
has been found that low surface energy resins on the image
receiving surface of the media helps to reduce the degree of
adhesion to what is deemed an acceptable range. Such low surface
energy resin comprises polymers that contain at least one structure
from the following list, silicone, fluoro-carbon, olefin, long
chain hydrocarbon, polycarbamate, amide wax, etc.
[0072] In one suitable embodiment, the erasable/reusable media
comprises a silicone coated substrate. As is generally known,
silicone resin is able to be coated onto all kinds of substrates.
In the PSA (Pressure Sensitive Adhesive) industry, release liners
are constructed using, e.g., such resins from GE Silicones (now
know as Momentive Performance Materials), Gelest, Dow Corning, etc.
Known silicone release coating systems include water based,
radiation based (such as UV or E-Beam), solvent based, and
solvent-less systems. Different degrees of cross-linking,
thickness, surface energy, release force, degrees of friction can
be achieved with the appropriate formulations. For example, to
adjust the release force (e.g., as measured by a PSA (pressure
sensitive adhesive) tape), additives (e.g., such as a control
release agent (CRA)) can be used to increase the release force.
Also, the addition of monomer/oligomers that have a higher degree
of crosslinking can increase the hardness of the coating. The
thickness of the silicone coating can also affect release,
friction, durability, etc. Resins that have a hybrid molecular
structure, e.g., that include siloxane or other organic or
inorganic structures including fluoro-carbonate, acrylic, epoxy,
urethane, etc. are also commercially available for use. In
addition, other molecular structures can also be incorporated into
a siloxane system by blending, crosslinking, etc. The addition of
organic or inorganic particles (micrometer, sub-micrometer, or
nano-meter) can also be used to modify properties of the
coating.
[0073] Siliconized paper or film commonly employed as release
liners in the PSA industry are available with silicone release
surfaces having all different kinds of properties. Such siliconized
paper or film is optionally used as the erasable/reusable media
described herein. Major sources of siliconized paper/film in the
USA include: Mitsubishi, Toray, Loparex, CP Films. For example,
siliconized surfaces that work well as erasable/reusable media,
e.g., with the commercial toner from HP, are available from
Mitsubishi Polyester. In particular, Mitsubishi polyester makes a
siliconized PET. Such siliconized PET includes 2SLK or 2SLKN for
PSA release liner applications as well as 2VC4N. 2VC4N is a
silicone coated PET release film designed for casting thin
solvent-based ceramic dielectric films with very uniform thickness
and smoothness. In accordance with the 2VC4N siliconized PET, one
side of the PET is super smooth and coated with silicone (similar
to the 2SLKN product) to achieve a low release force smooth
siliconized PET surface. The other side has smoothness similar to
the base film of 2SLKN. Traditionally, the smooth siliconized
surface of the 2VC4N material is used for casting ceramic
dielectric film. Of course, alternatively, another siliconized
paper or film may be developed, constructed and/or used for the
erasable/reusable media.
[0074] Optionally, coating and curing the silicone on a plastic
film may or may not be combined with the orientation of the plastic
film (in-line or off-line). In one suitable embodiment,
construction of the erasable/reusable media may employ a known
technique for in-line coating a silicone formulation on a plastic
such as PET, polycarbonate, polyester, polystyrene, acrylic,
urethane, polyether, etc. In accordance with this technique, the
film is heated to high temperature and tenter oriented. In this
way, a very thin silicone coating (e.g., less than 500 nm, or even
less than 100 nm) can be formed. A high degree of silicone curing
can be achieved because the film orientation process allows the
silicone coating to experience high heat. Whereas, processes that
thermally cure silicone on film without orientation may not always
heat beyond the film deformation temperature. The high degree of
curing gives a silicone surface that has very low silicone
migration transfer or rub-off. It is also believed that the high
temperature orientation process also allows stronger interfacial
interaction (interlocking, diffusion, etc.) between the silicone
layer and plastic film layer so that the silicone layer is more
durable and abrasion resistant. Optionally, a water based silicone
emulsion can be used for this coating so that a thin coat weight
can be achieved. Optionally, an adhesion promoter such as silane
(including alkyloxy silane, glycidoxy silane, etc.) can be added to
improve the adhesion of the coating to the plastic film
substrate.
[0075] Suitably, the silicone chemistry (e.g., such as that which
may optionally be employed in connection with the erasable/reusable
media disclosed herein) generally involves using a functional
siloxane prepolymer to react with a functional crosslinker under
the help of catalysts. The reaction can be additional (e.g., using
vinyl functional groups) or condensational. However, a
condensational reaction is generally less desirable due to the
toxicity of Sn containing catalysts. In any event, the prepolymer
can range from low molecular weight to high molecular weight. The
prepolymer can be functional only at two end group (for example
having vinyl group only at two ends of a long liner chain); or the
prepolymer can be multiple functional with additional crosslinking
sites. The relationship of prepolymer structure to the final
property can be view as follows. In particular, both end-blocked
and multifunctional polymers are available in a variety of
molecular weights. In general, high-molecular-weight end-blocked
polymers yield softer, more elastic coatings with easy release at
low peel speeds and higher release at high speeds.
Low-molecular-weight and multifunctional polymers, on the other
hand, yield harder, less flexible coatings with less
differentiation between high- and low-speed release force
values.
[0076] Most silicone formulations have a particular
structure-property relationship. Generally, a high molecular weight
prepolymer with end-block function will give a polymer network that
has a very low degree of crosslinking. Such a low crosslinking
structure gives a soft release coating but generally also has a low
coefficient of friction (COF). On the other hand, a low molecular
weight prepolymer with multi-function will provide a hard highly
crosslinked coating that has a high hardness but also a high
COF.
[0077] In studies, it has been found that most conventional
silicone systems tend to wear poorly and/or lack sufficient
abrasion resistance to be used for a high quality erasable/reusable
media surface. In particular, the mechanical erasing process
proposed herein can easily damage conventional silicone coatings.
In particular, a sharp object such as a blade edge can easily cut
in to the silicone and remove the silicone coating. Due to the
particular structure-property relationship of the silicone
formulation (described above), there are two ways proposed
hereafter to improve the abrasion resistance of the silicone
coating to achieve a media surface suitable for the erasable
application described herein.
[0078] The first way is to obtain a silicone layer or coating with
low crosslinking, which will tend to provide a relatively soft
release coating but otherwise has a relatively low COF (which is
advantageous in this case). If the low COF is the dominating
factor, the low COF will prevent the abrasion tool or eraser (e.g.,
such as a scraper or doctor blade) from cutting into the silicone
coating, but rather it will aid the abrasion tool or eraser to
slide on the silicone surface. For the same silicone formulation, a
relatively lower COF can be effectively achieved by using a low
silicone coat weight. Accordingly, e.g., an in-line siliconization
process that allows very thin silicone coatings to be made (e.g.,
such as around 100 nm or even below 100 nm) is advantageous.
[0079] As discussed, one method involves using a high MW (molecular
weight) release coating, e.g., such as ones obtainable from Dow
Corning, Wacker, etc. In this regard, it is typical that .about.500
cps (centipoise) is the maximum viscosity for commercial
solventless offerings. In one exemplary embodiment, the following
formula may be used for the Si coating proposed for the
erasable/reusable medium disclosed herein (with 10% net solids
content):
TABLE-US-00002 Component Amount (Supplier - Dow Corning) Function
(PPH) Syl-Off 7817 Silicone Vinyl Polymer 9.8 (+ Pt Catalyst &
Inhibitor) Syl-Off 7048 Silicone Hydride Crosslinker 0.2 Heptane
Dilution Solvent 85.0 Methyl Ethyl Ketone (MEK) Solvent/Anchorage
Aid 5.0
[0080] In practice, these components are mixed together and applied
to, e.g., an optionally corona treated PET. Suitably, the coating
is applied, e.g., using a low wire meyer bar (e.g., #0-#3). After
application of the coating, it is cured, e.g., in an oven for
approximately 60 secs. at 300.degree. F. In this manner, a cured,
silicone coated PET construction is produced that is suitable for
use as the erasable/reusable media proposed herein. Optionally, the
surface COF could be additionally manipulated by either increasing
or decreasing the amount of heptane in the formula (i.e., more
dilution will give less coat weight, and hence a lower COF). While
an anchorage additive was not included in the above-formula, one
could be provided if desired--e.g., a low amount of MEK is useful
for this purpose.
[0081] More generally, the coating is optionally formed from a
formulation including: (i) a silicone vinyl polymer or a silicone
silanol polymer; and, (ii) a silicone hydride crosslinker. The
coating may be made from a solventless formulation or a solvent
containing silicone formulation. Suitably, the viscosity of the
solventless silicone formulation is greater than 200 cP.
[0082] The second way is essentially opposite from the first
way--i.e., it involves making a hard coating on the
erasable/reusable media. However, a hard silicone coating (i.e.,
highly crosslinked) is generally associated with a higher COF.
However, if the hardness is a dominating factor, the hard coating
could be abrasion resistant too. Accordingly, there are proposed
herein a few ways to improve the hardness. First, relatively low
molecular weight and high crosslinking functionality (vinyl,
silicon hydride, silicone hydroxide, etc.) monomer or oligomers
silicone containing resin can be used that can cure to a highly
crosslinked network. Second, MQ resin (CRA) can be used to
introduce hard structure into the silicone network. A third way is
to improve the curing by heating to higher temperature, prolonged
curing time, more efficient catalyst system, etc. A fourth way is
to use additives such as hard organic or inorganic particles,
preferably submicron particles or nano-particles. For example,
suitable nano-particles are available such as colloidal silica from
Nissan Chemical or from Grace Davison (Ludox). A fifth way is to
use silicone resin with hybrid structure that contains other groups
like epoxy, acid, hydroxyl, acrylic, isocyanate, methylol, POSS,
etc. that can introduce a high degree of crosslinking. In
particular, POSS (polyhedral oligomeric silsesquioxane) is
available that can have various degree of crosslinking and
hydrophobicity. POSS can also be used together with silicone
coatings. For example, Gelest sells a POSS based silicone resin
product for making an abrasion resistant hard-coating called
HardSil. A sixth way is to reduce the silicone thickness (e.g., to
less than about 1 um). That is to say, a soft silicone coating
coated on a hard substrate may well perform like a hard surface if
the silicone coating is very thin. A seventh way is to use an
adhesion promoter together with the silicone or as a primer between
the silicone coating and the coating substrate. The primer or
adhesion promoter can improve adhesion of the silicone based
coating to the substrate and thus offer better abrasion resistance.
Of course, it is noted that abrasion resistant is not solely
related with hardness. For example, a hard and brittle material
will not generally have good abrasion resistance.
[0083] Additionally, a low surface friction will also improve
abrasion resistance. Polyolefins can be applied on the media
surface by coating, extrusion, or lamination. Fluoro-carbon
containing polymers can be applied on the media surface by coating
or by extrusion or by lamination. In general, fluoro-carbon coating
polymers compared with silicone based polymers tend to have lower
surface friction, higher abrasion resistant. One example of a
suitable fluoro-carbon containing coating is a coating (Dow Corning
2601) that is generally designed for anti-graffiti
applications.
[0084] Chemicals containing silicone, fluoro-carbon, olefin, long
chain hydrocarbon, amide, wax can also be incorporated in the media
surface as additives instead of as polymeric binder materials. The
binder materials can be any kind of polymer or coating including:
thermal plastic or thermal-set, polycarbonate, acrylic, polyester,
urethane, polyolefin, silicone, Teflon.RTM. (i.e.,
polytetrafluoroethylene (PTFE)), etc. As additives, the chemicals
containing silicone, fluoro-carbon, olefin, long chain hydrocarbon,
amide, wax can give the media surface desired properties. For
example, silicone oil, pre-crosslinked silicone particle, silicone
containing surfactants, fluoro-carbon particles, fluoro-carbon
surfactant, wax particles, oil, hydrocarbon wax, amide wax, etc.
can be incorporated into a coating or film as additives. Such
additives can give the surface slippery, low friction, anti-block,
abrasion resistance, as well as release properties.
[0085] Suitably, the surface layer of the media comprises a film
only. In one possible embodiment, the whole construction of the
media can be one film. The film can be extruded, coextruded,
laminated, cast, etc. The film can be thermal plastic or
thermal-set. The film materials can my any kind of plastic film
including polyester, polycarbonate, polyolefin, polysulfone, etc.
Slip agents can be added into the film to provide desired abrasion
resistance, degree of adhesion and release, low friction, etc.
Common industrial slip agent typically comprise silicone containing
chemical, fluoro-carbon containing chemical, long chain hydrocarbon
containing chemicals, olefin wax, amide wax, inorganic particles
(silica, alumina, etc.), lubricating oil, etc. For the slip agents
that are liquid, continuous migration of slip agent to the surface
can be expected, even after the slip agent at the surface is wiped
off. It is to be understood that with the right kind and sufficient
amount of slip agents, a film surface can have the appropriate
adhesion, release and abrasion resistance for the print and erase
applications described in this specification.
[0086] In any event, suitably, the kinetic Coefficient of Friction
(COF) of the coated surface (i.e., the surface intended to receive
markings) relative to a stainless steel plate is less than about 4
in one embodiment, or less than about 2 in another embodiment, or
less than about 1 in still a further embodiment, or less than about
0.5 in still another embodiment, or less than about 0.3 in yet one
more embodiment. Suitably, the foregoing kinetic COF measurements
can be obtained using an IMASS SP-2000 Slip/Peel Tester (IMASS
Inc., Accord, Mass.) with a 200 g sled on a stainless steel plate,
a 5 kg cell, a 4 sec delay setup, a speed of 6 in/min, a run for
about 50 sec average, and a sample cut to a size of about
4''.times.5'' which is attached to the sled.
[0087] In the embodiments where the toner used tends to have poor
adhesion to most common plastic surfaces, special toner is
optionally formulated and made to have poor structural integrity
and/or poor adhesion to plastic or paper surfaces. Such specially
made toner will be described in greater detail below. However, in
this case, many common plastic films or coatings can be used for
the erasable/reusable media described herein. These films include
thermal plastic or thermal-set, polycarbonate, acrylic, polyester,
urethane, PVC (polyvinyl chloride), etc. The coatings can be
urethane, vinyl, acrylic, etc. However, it is still desired that
such film or coating have enough abrasion resistance to endure as
many mechanical erases as possible.
[0088] Suitably, the media also has good heat dimension stability
as xerographic imaging generally employs heating of the toner to
fuse the toner to the media surface. For example, it can be
desirable for the print media to have a dimensional change of less
than 4 percent (or optionally below 1 percent) in both directions
after heating to 100 degrees C. for 10 minutes.
[0089] Additionally, the film and paper used in the construction of
the media can optionally be made from renewable supply
(agriculture), such as PLA (polylactide) polymer, or made to be
recyclable or biodegradable. For most polymers that are not
otherwise biodegradable, additives can be included to can help to
make the resins biodegradable. It has been generally accepted that
siliconized film (such as siliconized polyester, polycarbonate,
etc.) can not be recycled, i.e., because the silicone component
made the polymer unable to be recycled. However, the siliconized
film in this application may still be recyclable in large part
because of the very thin silicone coating being used on a
relatively thick polymer film. For example, if the silicone coating
is 100 nm on a polyester film of 100 um, assuming the silicone and
polyester have similar density, then the weight percent of the
silicone in the polymer is about 1:1000. With such as ratio, the
silicone may be ignored, or some process can be employed to remove
the silicone, e.g., such as flame treatment of the siliconized
surface or some other silicone removing treatment.
[0090] Suitably, at least one of the media surfaces have antistatic
or static dissipative properties. Without such static control
properties, the media can be hard to handle, e.g., by devices
and/or by users. For example, in one suitable embodiment, it is
desired that the surface resistivity be somewhere between about
10.sup.6 to about 10.sup.15 Ohm/Square. Optionally, in another
suitable embodiment, it is desired that the surface resistivity be
somewhere between about 10.sup.6 to about 10.sup.15 Ohm/Square.
Optionally, in still another suitable embodiment, it is desired
that the surface resistivity be somewhere between about 10.sup.6 to
about 10.sup.11 Ohm/Square. Optionally, an antistatic and/or static
dissipative agent can be added to the construction of the
erasable/reusable media. The additives can be hygroscopic
materials, quaternary ammonium materials, or semiconductive
particles (mostly particles of semiconductive metal oxides).
[0091] In one exemplary embodiment, the erasable/reusable media has
some stiffness and mechanical strength to tolerate the handling by
user's hands as well the printing/marking and erasing processes. A
thick and/or stiff construction also helps the user to
differentiate the special "media" against normal printing media. If
plastic film is used as the main construction, the plastic film
suitably has some minimum thickness. For example, if white
polyester film is used as the main media core material, the
polyester film may be, e.g., at least 2 mil thick and preferably
3.5 mil thick. Optionally, the polyester film includes, e.g., a
TiO.sub.2 whitening or BaSO.sub.4.
[0092] Alternately, a paper/film laminate construction may also be
used as the core structural material of the media. For example,
such a laminate construction has the following advantages: 1)
higher stiffness and mechanical strength due to the composite
laminate structure, 2) good thermal stability of the paper and
surface smoothness of the film, and 3) lower cost due to the use of
low cost paper. However, if paper is used, it is advantageous that
a sandwich construction of film/paper/film is used, insomuch as
comparatively a mere binary construction of film/paper typically
has curl issues associated therewith. However, a binary
construction of film/paper may be made by laminating a plastic film
on a paper. Likewise, a sandwich construction of film/paper/film
may be made by laminating plastic film on two sides of a paper with
suitable surface coating sides facing out. The plastic film may be
one-side surface coated before or after the lamination. Optionally,
the lamination may use lamination adhesive. Heat seal adhesive may
also be used. The lamination adhesive may be applied by extrusion,
by coating (water based, solvent base, radiation based, etc.).
[0093] In general, one side of the media can be treated for
erasable applications. In this case, the other side may allow
permanent writing or printing. Alternatively, both sides of the
media can be treated for erasable applications. In one embodiment,
the media can be white plastic film coated with a silicone coating.
The white plastic film could be polyester, polycarbonate, PEEK
(polyether ether ketone), polyolefin, polyamide, polyimide, and
other polymers with strong mechanical strength. The films can be
made white due to addition of whiting agent such as TiO.sub.2,
BaSO.sub.4, CaCO.sub.3, etc. Cavities can be formed in films that
can also provide an opacity effect. For example, CaCO.sub.3 is
typically used as a cavitating agent. The white film can have one
side or both sides silicone coated.
[0094] As can be appreciated, most of the media constructions
discussed above have a slippery surface that may be hard to handle
by printing/marking and/or erasing devices. For example, a normal
paper supply tray typically has a media pickup device, which can
have paper jam issues if siliconized film is used in the tray.
Accordingly, in accordance with aspects of the present inventive
subject matter, it is advantageous that a special paper handling
mechanism may be implemented in the printing and/or erasing
devices. For example, high friction rollers can be used that do not
slip on the slippery media surface. Or, the media may have a high
friction edge. The high friction edge can be made either by having
a high friction material (rubber, paper, etc) on the surface of the
edge or by having a rough surface. The rough surface can be made by
embossing, etc. Alternatively, holes or sprocket holes can be
formed on the edges of the media. The holes can help to feed and
guild the media, e.g., during printing/erasing. The holes can also
be used later to selectively bind sheets of the media together.
[0095] As mentioned above, optionally, the erasable/reusable media
maybe constructed or otherwise configure with a sacrificial coating
or layer on the image receiving surface or side of the media.
Suitably, the sacrificial coating is a material to be applied as a
coating onto the media. For example, the coating application can
happen after each (or some) erase(s) or before each (or some)
printing(s) or marking(s) or during each (or some) printing(s) or
marking(s) but before the fusing or transfer step. Essentially, the
sacrificial coating improves the receiving/release property of the
media. In operation, during each erase, at least a portion of the
sacrificial material is intentionally removed together with the
toner or other marking agent forming an image on the media, and
accordingly, it is referred to as "sacrificial". However, after one
or more erasing operations, because some or all of the sacrificial
material has been removed from the media, more of the sacrificial
material is optionally reapplied, e.g., at station 50. Considering
the sacrificial coating is removed, this coating can optionally be
absorbing (i.e., with a rough or porous structure). In this way,
the coating can facilitate the reception and erasing of toner or
other marking agents.
[0096] Optionally, the sacrificial coating can be a water-based or
solvent-based coating (e.g., using an organic solvent that has low
health risks) and thus the coating process may incorporate a drying
step. Alternately, the coating may not include water or solvent.
For example, in one embodiment, the coating can be a continuous or
non-continuous coating of a special toner (e.g., clear or white
color) and be coated on the media using a xerographic process. In
another embodiment, the sacrificial coating can be a material that
is liquid at high temperatures and solidifies at lower
temperatures. Accordingly, it can be applied as liquid at high
temperature and function as a solid at lower temperature. For
example, wax can provide such melting characteristic. In another
embodiment, the coating can be in the form of oil, grease, or wax
that can be smeared, rubbed, or brushed onto the surface or image
receiving side of the media. The chemical structure of the
sacrificial coating or layer may optionally include silicone,
fluoro-carbon, long-chain hydrocarbon, etc. Optionally, organic
(pre-crosslinked resin particle) or inorganic particles (silica,
alumina, talc, TiO2, CaCO3, etc.) may be added to the coating
formulation. The particles function as a spacer so that the during
the toner fusion step of the marking process, the melted toner will
have less interaction with the media surface under the sacrificial
coating. The particles may also help the mechanical removal by
reducing the structural integrity of the sacrificial coating and
also can function as abrasive particles during erasing.
[0097] Optionally, at, on or under the surface of the
erasable/reusable media some permanent printing or markings or
other indicia may be applied that will not be removed by the
erasing operation, e.g., as applied by the erasing station 60. For
example, the indicia may indicate that the media is a special one
designed for erasable and/or reusable applications. Suitably, it
can serve the function of media type discrimination, i.e.,
informing the user and/or system 10 which media is for normal or
standard printing or imaging (i.e., so called permanent jobs) and
which media is for erasable printing or imaging (i.e., so called
temporary jobs). For example, these markings or indicia may be read
and/or otherwise used by the media type detection station 30 to
determine what type of media a particular sheet is made from, i.e.,
standard media or erasable/reusable media. Optionally, a special
bar code or other substantially unique identifier can also be
permanently printed or marked on sheets of the erasable/reusable
media in order to identify and/or keep track of them. In one
suitable embodiment, e.g., the system 10 may monitor the bar codes
or other identifiers in order to keep track of how many times a
particular sheet is used. In this way, sheet use tracking may
optionally be maintained by the system 10 rather than indicating
the number of uses on the sheet itself.
[0098] Suitably, in embodiments where the marking agent comprises a
toner, the toner is able to solidify on the surface of the
erasable/reusable media to have controlled adhesion. Ideally, the
adhesion is high enough so that normal abrasion or usage will not
remove it from the media--however, it can be removed with a
designated mechanical removal operation (e.g., strong rubbing,
abrasion, scratching, scraping, etc.) or other suitable erasing
operation applied to the media, e.g., by the erasing station 60. In
practice, toner works well on film based or coated media where the
surface is substantially non-absorbing. Typical toners are mainly
made of low molecular weight resins and colorants (e.g., pigment or
dye). The low molecular weight resins are mainly acrylic polymer,
styrene acrylic, polyester based, etc., and there may be other
additives such as rosin, rosin derivatives, silica, etc. Generally,
the toners are made into micrometer size particles.
[0099] To make the toners more susceptible to erasing (e.g., by the
mechanical erasing described herein), a few method can be used.
First, a release agent can be added to the toner composition.
Suitably, release agents are materials that comprise molecular
structure(s) from the following group: silicone, fluoro-carbon,
long-chain hydrocarbon, amide, etc. Optionally, the release agent
may come in solid or liquid form as desired. Functionally, the
release agent prevents good fusion of the toner to the image
receiving surface of the media, and it also prevents good fusion
between the toner particles. Second, special particles can be added
to the toner formulation. For example, these special particles can
include inorganic particles (such as silica, alumina, talc,
CaCO.sub.3, etc.) or organic particles that either have a melting
temperature (or glass transition temperature or softening
temperature) higher than the toner resin or that are
pre-crosslinked and thus tend to not melt at all. The melting
temperature of common toner resin is between 80.degree. C. and
140.degree. C. Accordingly, suitable organic particles that have
very high melting temperatures (i.e., above the aforementioned
range) include, for example, polyamide wax, TPX, Teflon.RTM., PVC,
etc. Suitable examples of pre-crosslinked organic particles include
crosslinked silicone powder from Dow Corning, Epostar powder from
Nippon Shokubai, Daiplacoat crosslinked PU (polyurethane) powder
from Dainichiseika Color & Chemicals, etc. Third, resins with
melting temperature on the high end of the typical toner melting
range (80.degree. C. to 140.degree. C.) or lower melt flow (higher
flow viscosity at melt) can be used. Fourth, lower amounts of resin
in the toner compared with color pigment will also give lower
adhesion strength to the fused toner. In one exemplary embodiment,
the erasable toner or other marking agent includes a release agent
with a weight percent greater than about 1%, wherein the release
agent includes at least one of silicone, fluoro-carbon, organic
pre-crosslinked particles or organic thermal plastics particles
with a melting temperature greater than 200.degree. C. Optionally,
in another embodiment the release agent has a weight percentage
greater than about 3%, or in still another embodiment a weight
percentage greater than about 5%.
[0100] In one suitable embodiment, preferably at least 50% of the
toner or other marking agent is erased (e.g., at the erasing
station 60) by rubbing, brushing, abrasion, scraping, scratching,
etc. (which is generally referred to herein as "mechanical" removal
or erasing). Optionally, other additional removal steps and or
processes by other means such as heat transfer, solvent washing,
etc. can be combined with the mechanical removal and/or otherwise
implemented as well. Suitably, the removal maybe done in a
"recycle/erase" machine or device separate from the printer or
marking engine or build-in with the printer or marking engine
(e.g., as shown in the system 10).
[0101] In general, a sheet of the erasable/reusable media is feed
in from a tray or as shown in FIG. 1 received by the erasing
station 60 along a suitable paper path or media routing path.
[0102] With reference now to FIG. 2, there is shown an exemplary
erasing station 60. Once received, the erasable/reusable sheet of
media 62 is optionally fixed on and/or otherwise held by a media
support 64, e.g., having as shown in FIG. 2 a flat surface 64a or
alternately a curved or a drum surface. Suitably, the media 62 is
fixed to and/or held by the support 64 via any one or more of the
following: static, a vacuum, low degree adhesion, friction, nip
pressure, sprocket holes on the media 62, etc.
[0103] In the embodiment shown in FIG. 2, the eraser 66 is
positioned or otherwise arranged over and/or otherwise proximate to
the media 62 so as to be in contact with the image receiving
surface or toner bearing side of the media 62. In the illustrated
embodiment, linkage 68 operatively connects the eraser 66 to a
motorized (e.g., via motor 63) or otherwise powered drive assembly
69 which pulls, pushes and/or otherwise moves the eraser 66 across
and/or over the contacted surface of the media 62, thereby
scraping, scratching, rubbing, brushing, abrading and/or otherwise
mechanically removing the toner or other marking agent from the
contacted surface of the media 62. Optionally, where a sacrificial
layer or coating has been employed on the media 62, this operation
may also intentionally remove all or some portion thereof.
[0104] Suitably, the removed toner (along with any optionally
removed sacrificial material) comes off as a solid dust.
Accordingly, the erasing station 60 is optionally equipped or
otherwise provision with a suitable vacuum 65 or the like that
sucks, captures and/or otherwise removes the dust from the media
62. Alternately or in addition, the erasing station 60 is equipped
and/or provisioned with a brush or other wiping device that brooms,
rubs or wipes the dust off the media 62. Optionally, the recovered
dust and/or toner is deposited in a collection receptacle 67 from
which it can be selectively recycled or otherwise disposed of. If
recycled, the collected dust and/or toner may optionally be cleaned
or reconditioned before being retuned to the marking station 70 for
reuse. In any event, once the media 62 has been erased, it can be
released from the support 64 and fed into another tray for cleaned
media or fed into the appropriate paper path or media routing path
for further processing, e.g., it may be forwarded to the marking
station 70 for additional reuse.
[0105] As shown in FIG. 2, the eraser 66 takes the form of a blade
drawn across the tone bearing surface of the media 62. However, in
practice, the eraser is optionally implemented as any object that
will press or contact and translate or move relative to the surface
of the media 62 to at least partially remove the toner or other
marking agent therefrom. As the eraser 66 contacts the surface of
the media 62 to perform the mechanical removal of toner or other
marking agents, suitably, the eraser 66 engages on the contacted
surface of the media 62 with some controlled pressure, e.g., that
can be adjusted via means 200 either mechanically or
electronically. Suitably, the pressure is high enough to have
effective toner removal but not too high to damage the media 62.
Optionally, the pressure is applied by means of a motor, a cam, a
roller, a lever, a weight, a solenoid, etc. In one embodiment, a
pressure sensor 202 is used to provide feedback control of the
applied pressure.
[0106] In the illustrated embodiment, the eraser 66 is moved
relative to the media 62 while the media 62 remains stationary on
the support 64. However, in practice, the media 62 can moved
relative to a stationary eraser 66 or both the eraser 66 and the
media 62 can be moved relative to one another. For example, a
desired movement of the media 62 can be achieved via suitable
motorized or other driving of the media support 64 holding the
same. To facilitate placement and/or removal of the media 62 on
and/or from the support 64 as well as to achieve the desired
contact and/or pressure when erasing is to be preformed, optionally
the eraser 66 can be lift up (i.e., away from) or down (i.e.,
toward) relative to the support 64 or the support 64 can be lifted
up (i.e., toward) or down (i.e., away from) relative to the eraser
66 or both can be provisioned for relative movement away and/or
toward one another. That is to say, when the media 62 is being
loaded onto and/or removed from the support 64, optionally the
eraser 66 and/or support 64 are moved and/or positioned relative to
one another so as to form a gap therebetween which provides
sufficient clearance for the media 62 to be arranged on the surface
64a of the support 64. Then at or about the time when the erasing
operation is ready to begin, the eraser 66 and/or support 64 are
moved and/or positioned relative to one another such that the
eraser 66 makes the desired contact with the toner bearing surface
of the media 62. Finally, at or about the time when the erasing
operation is finished, the eraser 66 and/or support 64 are moved
and/or again positioned relative to one another so as to form a gap
therebetween which provides sufficient clearance for the media 62
to be removed from the surface 64a of the support 64.
[0107] In practice, optionally the eraser 66 is initially engaged
with the media 62 some distance past or after the leading edge of
the media 62 so that the media 62 will not be ripped off the
support 64 when the erase 66 is drawn across the media 62. In
another embodiment, the front and/or other edges of the media 62
are optionally inserted or otherwise protected under a cover or
other like protective barrier or means that bars contact between
the eraser 66 and the covered or inserted portion of the media 66
to prevent the media 62 from being ripped off the support 64 by the
relative movement of the eraser 66. In this embodiment, suitably,
when the relative movement of the eraser 66 begins it slides easily
over the cover or the like and then lands on the toner bearing
surface of the media 62. Suitably, in this embodiment, the distance
between the support 64 and eraser 66 can be fixed so that neither
has to be provisioned to move toward and/or away from one
another.
[0108] While FIG. 2 suggests a relatively simple motion for the
erase 66 with respect to the media 62, in practice a more complex
movement can be applied. For example, the eraser 66 may optionally
comprise a disk, a belt, a cylinder, or a cone that can rotate or
spin while at the same time moving relatively across the contacted
surface of the media 62. Alternately or in addition, a vibration
motion can also be applied to the media 62 or the eraser 66. For
example, the vibration motion can be a slow frequency or a high
frequency, including ultra-sonic vibration.
[0109] As shown in FIG. 2, for scraping or scratching, the eraser
66 optionally takes the form of a single blade. Alternately, an
array of blades, or one or more other tips can be used which press
onto and/or move across the toner bearing surface of the media 66.
Suitably, the blade or tips can be made of metals including
stainless steel, brass, copper, aluminum, etc. The blade or tips
can also comprise thermal plastic or thermal set polymeric material
such as PEEK, polyester, acrylic, styrene, HDPE (high density PE),
LDPE (low density PE), PP, Polyether imide, Polyamide, Nylon, ABS
(acrylonitrile butadiene styrene), etc. The blade or tips can also
be made from composite materials such as ceramic, carbon black, or
fiber reinforced polymeric materials. The blade or tips can
optionally have all kinds of geometrical shapes and/or various
bevel angles. In one suitable embodiment, any one or more of a
selection of special doctor blades from a leading company (such as
Allison Systems Corporation) can be used for the eraser 66.
[0110] In any event, suitably the blade or tip is designed such
that with an appropriate application of enough pressure on the
toner bearing surface of the media 62, the blade scrapes off the
toner but is not too sharp to damage the media 62. Suitably, the
blade is spring loaded or the blade itself can be a spring to
achieve the desired pressure while engaging the toner bearing
surface of the media 62 at a suitable angle. Optionally, to guard
against damage to the blades or sharp tips by environmental dust or
other objects on the contacted surface of the media 62, a
preliminary cleaning (for example by brushing) may be performed
before the media 62 is sent to the blade(s) or sharp tip(s).
Alternatively, a scanning, observation and/or other evaluation of
the media 62 can be done; and if it is determined that a particular
sheet of media 62 will damage the erasing mechanism, then that
sheet can be rejected.
[0111] With reference now to FIGS. 3A and 3B, there are shown
exemplary blade type erasers 66 suitable for use in the present
application. It has been found that blades with sharp corners can
tend to cut, tear or rip the media 62 when they advanced across the
same. Accordingly, it is advantageous that a blade type eraser 66
does not have a sharp corner. Accordingly, as shown in FIG. 3A, the
corners 66a of the media contacting edge or side of the blade have
been turned-up slightly so as to curve away from the toner bearing
surface of the media 62. Alternately, as shown in FIG. 3B, the
corners 66a of the media contacting edge or side of the blade have
been rounded-off slightly so as to not contact a sharp corner with
the toner bearing surface of the media 62.
[0112] In yet another suitable embodiment a brush, a rubbing
element, or a felt can be used as the eraser. In this case, the
materials used for the eraser are optionally soft so that the
eraser will not damage the media. Suitably, the brush, rubbing
element, or felt can be a cylindrical roll that spins with the roll
surface touching the media or a flat disk (circular or
non-circular) that spins with the flat surface touching the media.
For example, spinning may be at a rate between 10 Hz to 10 kHz. In
case heat is generated due to the friction created between the
spinning eraser and the media, a cooling mechanism 220 is
optionally employed. For example, cooling may be achieved by a
blower that generates a cooling air flow, by thermal-electrical
cooling, by refrigeration, or simply by heat conduction via a good
thermal conductor to a sufficiently large thermal mass. It is to be
appreciated that heating is generally not desired in this context
because it can cause melting of the toner which can then be smeared
around on the media or the melted toner can even contaminate the
eraser itself. As already mentioned, the brush, rubbing element or
felt can also be in the form of a belt. In this case, rollers can
optionally move to move the belt to introducing a rubbing, brushing
and/or scraping motion against the toner bearing surface of the
media. Alternately, the brush, felt, or rubbing element can also be
in the form of a flat surface or a narrow strip. With suitable
pressure (even without spinning or rotating), the erase is able to
scrape/brush/rub on the media to erase the toner therefrom. For
example, in this way, the eraser can act similar to an eraser for a
dry-erase white board.
[0113] It is to be understood that because the erasing method
involves mechanical rubbing, scraping, brushing, etc., undesired
static charge may be generated by this process. Accordingly, the
erasing station 60 is optionally equipped and/or provisioned to
eliminate or otherwise deal with this static charge. For example,
the static charge may be handled via: corona treatment, static
charge reception/discharge and grounding, etc.
[0114] In one exemplary embodiment, the easer does not have to
contact the media 62. Rather the eraser can be an energy source
that focuses or otherwise directs radiant energy onto the sheet of
media 62 to remove the toner or marking agent therefrom. For
example, the erase optionally focuses or otherwise directs laser,
sonic or other radiant energy at the media 62 which causes the
toner to be removed therefrom. Suitably, the radiant energy is
chosen and/or otherwise manipulated so as to be selectively
absorbed otherwise interact with the toner, e.g., as opposed to the
media itself.
[0115] It is to be appreciate, that optionally the
erasable/reusable medium described herein is optionally constructed
and/or otherwise configured be imaged on one or both sides thereof.
Accordingly, the erasing station 60 is optionally equipped or
provisioned to erase either one or both sides of the media.
Suitably, via known media handling techniques, the media may simply
be flipped as appropriate to present the side being erased to the
eraser 66. Alternately, a pair of erasers may be employed to erase
the respective sides of the media. Suitably, if otherwise two-sided
media is in fact only printed, marked or imaged on one side,
optionally the evaluation station 40 or the like is able to decide
which side to erase, and accordingly, media is presented to the
erasing station 60 in the appropriate orientation (i.e., with the
side to be erased facing the eraser 66).
[0116] The uses for the embodiments described herein and/or their
equivalents are many. For example, any matter that is desired to be
printed but only for a limited period of time can be achieved with
these embodiments. For instance, newsletters or other periodicals
(e.g. newspapers, magazines) could be downloaded via the Internet
and printed by an individual reader in a temporary manner as
disclosed herein. Of course, this can be done on a continuous
basis, repeatedly using the same sheet or sheets of media that have
been intermittently erased with the marking agent removal method as
described herein. In this manner, the environmental impact of the
printing is reduced to almost zero because the "paper" is recycled
over and over again. The user could thus read each days' newspaper
or any periodicals in the morning, where it may have been
automatically downloaded overnight and printed, and then reload the
sheets into the printer, where the ink would eventually be erased
with a erasing unit integrated in the printer with the mechanisms
disclosed herein and the sheet would thus become ready to be
printed upon again. A user could print other matter as well, for
instance temporary signs such as "For Sale" signs. Temporary ID
cards could also be issued in this manner, such as visitor badges,
airport boarding passes, etc. Schools could print all sorts of
materials with the embodiments disclosed herein, such as short term
handouts and examination sheets. In a still further embodiment,
students could be given pens or other like hand-held writing
instruments 300 (see FIG. 4) filled with disappearing ink to
temporarily mark or write out their answers on such examination
sheets. In an alternate embodiment, the writing instrument 300
could be filled with a marking agent 302 (e.g., such as those
described herein) which is erasable from the reusable medium, e.g.,
using the same erasing process carried out by the erasing station
60. Accordingly, on a document (e.g., printed by the marking
station 70), an individual could provide editorial comments, write
on or otherwise mark the erasable/reusable media as desired with
such a writing instrument 300, and the corresponding marks could
later be erased with the rest of the document.
[0117] In further uses of the embodiments described herein, books
can be printed temporarily. Users could be provided with kits
including a printer, printing substrates/paper and binding means to
enable the users to print books on the reusable paper and
optionally bind into a book. Once the user has finished reading the
book, the pages can be unbound and reused to print another book.
The binding and unbinding can alternatively be a function performed
by the printer at the user's discretion. Further functions provided
by the printer can include applying a barrier layer onto a printed
sheet, sealing the barrier layer, and erasing markings on the
barrier layer such as by differential wetting with a second liquid
(separate and different from the disappearing inks) or a wiper
roller.
[0118] Other office accessories can be configured to work with the
reusable print media. For example, special erasable writing
instruments, pens, or high lighter can be configured to work with
the reusable print media. Sheet protectors can be used with the
print media to protect the print media for even prolonged reading,
transportation, or more rough usage. The print media could already
have punch holes so that they can be put in a binder.
[0119] In any event, it is to be appreciated that in connection
with the particular exemplary embodiment(s) presented herein
certain structural and/or function features are described as being
incorporated in defined elements and/or components. However, it is
contemplated that these features may, to the same or similar
benefit, also likewise be incorporated in other elements and/or
components where appropriate. It is also to be appreciated that
different aspects of the exemplary embodiments may be selectively
employed as appropriate to achieve other alternate embodiments
suited for desired applications, the other alternate embodiments
thereby realizing the respective advantages of the aspects
incorporated therein.
[0120] It is also to be appreciated that particular elements or
components described herein may have their functionality suitably
implemented via hardware, software, firmware or a combination
thereof. Additionally, it is to be appreciated that certain
elements described herein as incorporated together may under
suitable circumstances be stand-alone elements or otherwise
divided. Similarly, a plurality of particular functions described
as being carried out by one particular element may be carried out
by a plurality of distinct elements acting independently to carry
out individual functions, or certain individual functions may be
split-up and carried out by a plurality of distinct elements acting
in concert. Alternately, some elements or components otherwise
described and/or shown herein as distinct from one another may be
physically or functionally combined where appropriate.
[0121] In short, the present specification has been set forth with
reference to preferred embodiments. Obviously, modifications and
alterations will occur to others upon reading and understanding the
present specification. It is intended that the invention be
construed as including all such modifications and alterations
insofar as they come within the scope of the appended claims or the
equivalents thereof.
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