U.S. patent application number 09/835750 was filed with the patent office on 2001-12-27 for photosensitive media cartridge having an ambient condition sensor.
Invention is credited to Allen, Loretta E., Lai, Yeh-Hung, Reinke, Stephen M., Wang, Yongcai.
Application Number | 20010055109 09/835750 |
Document ID | / |
Family ID | 24393833 |
Filed Date | 2001-12-27 |
United States Patent
Application |
20010055109 |
Kind Code |
A1 |
Allen, Loretta E. ; et
al. |
December 27, 2001 |
Photosensitive media cartridge having an ambient condition
sensor
Abstract
A photosensitive media cartridge includes an ambient condition
sensor mounted in the cartridge for sensing ambient conditions in
the cartridge. When the cartridge is positioned at a media transfer
position on an image forming device that permits the conveyance of
media from the cartridge to the image forming device, image
development or printing on the media in the image forming device is
controlled based on the sensed ambient conditions in the
cartridge.
Inventors: |
Allen, Loretta E.; (Hilton,
NY) ; Wang, Yongcai; (Webster, NY) ; Reinke,
Stephen M.; (Rochester, NY) ; Lai, Yeh-Hung;
(Webster, NY) |
Correspondence
Address: |
Milton S. Sales
Patent Legal Staff
Eastman Kodak Company
343 State Street
Rochester
NY
14650-2201
US
|
Family ID: |
24393833 |
Appl. No.: |
09/835750 |
Filed: |
April 16, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09835750 |
Apr 16, 2001 |
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09597999 |
Jun 19, 2000 |
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6268094 |
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Current U.S.
Class: |
355/400 ; 355/40;
355/77 |
Current CPC
Class: |
G01N 25/56 20130101;
G03F 7/003 20130101; G03B 2227/325 20130101 |
Class at
Publication: |
355/400 ; 355/40;
355/77 |
International
Class: |
G03B 027/00 |
Claims
What is claimed is:
1. A photosensitive media cartridge comprising: a housing for
holding a stack of photosensitive media; and an ambient condition
sensor mounted within said housing for sensing ambient conditions
in said housing and providing an ambient condition signal
indicative thereof, wherein a development of the photosensitive
media is based on the sensed ambient condition.
2. A cartridge according to claim 1, wherein said housing comprises
a first section and a second section which are attachable to each
other.
3. A cartridge according to claim 2, wherein said ambient condition
sensor comprises: a spring plate attached to one of said first and
second sections of said housing; a first contact plate having a
first electrode, said first contact plate being mounted on said
spring plate; a sampling material mounted on said first contact
plate; and a second contact plate having a second electrode, said
second contact plate being mounted on said sampling material.
4. A cartridge according to claim 3, wherein said sampling material
is responsive to humidity conditions within said housing, such that
a change in humidity value within said housing causes a change in a
measured capacitance of said sampling material.
5. A cartridge according to claim 1, wherein said photosensitive
media comprises microcapsules which encapsulate imaging
material.
6. A cartridge according to claim 5, wherein said imaging material
comprises coloring material, and said cartridge is adapted to be
inserted into a printer having a pressure assembly for applying
pressure to said photosensitive medium to crush said microcapsules
and develop a latent image on said photosensitive medium.
7. A cartridge according to claim 6, wherein when said cartridge is
inserted in the printer, said ambient condition sensor is adapted
to provide said ambient condition signal to the pressure assembly
to control an amount of pressure applied to the photosensitive
medium in said printer based on the sensed ambient condition in
said cartridge.
8. A cartridge according to claim 7, wherein said ambient condition
is a sensed humidity in said cartridge.
9. A cartridge according to claim 3, wherein said first and second
electrodes extend from an interior of said cartridge to an exterior
of said cartridge.
10. A cartridge according to claim 1, wherein said cartridge is
adapted to be inserted into a printer having an imaging head and a
heater.
11. A cartridge according to claim 10, wherein a light exposure of
said imaging head is adjusted based on said ambient condition.
12. A cartridge according to claim 10, wherein a temperature of
said heater is controlled based on said ambient condition.
13. A cartridge according to claim 10, wherein a printing speed of
said printer is controlled based on said ambient condition.
14. A cartridge according to claim 1, wherein said ambient
condition sensor comprises a substrate with conductive terminals
and a humidity sensitive material coated on the substrate.
15. An image forming arrangement comprising: an image forming
device for forming a latent image on a photosensitive medium, the
photosensitive medium comprising a plurality of microcapsules which
encapsulate imaging material, the image forming device comprising a
pressure assembly for applying an initial pressure to said
photosensitive medium to crush said microcapsules and develop a
latent image on said photosensitive medium; and a media cartridge
for holding a stack of said photosensitive medium therein, said
media cartridge being adapted to be inserted into said image
forming device to permit a conveyance of said photosensitive medium
to said image forming device, said media cartridge comprising an
ambient condition sensor mounted within said cartridge for sensing
ambient conditions within said cartridge and providing an ambient
condition signal indicative thereof to said pressure assembly, such
that an amount of pressure applied by said pressure assembly is
based on the ambient conditions sensed by said ambient condition
sensor in said cartridge.
16. An image forming arrangement according to claim 15, wherein
said ambient condition sensor comprises: a spring plate attached to
said cartridge; a first contact plate having a first electrode,
said first contact plate being mounted on said spring plate; a
sampling material mounted on said first contact plate; and a second
contact plate having a second electrode, said second contact plate
being mounted on said sampling material.
17. An image forming arrangement according to claim 16, wherein
said sampling material is responsive to humidity conditions within
said cartridge, such that a change in humidity value within said
cartridge causes a change in a measured capacitance of said
sampling material.
18. A method of controlling image development, the method
comprising the steps of: providing an ambient condition sensor in a
cartridge which holds photosensitive media therein, said ambient
condition sensor sensing ambient conditions within said cartridge
and providing an ambient condition signal indicative thereof to a
development member of a printer; inserting the cartridge to an
insertion position in said printer which permits a passage of
photosensitive media from the cartridge to a development member in
the printer; and controlling a development of images on the
photosensitive media based on the ambient condition signal received
from the ambient condition sensor mounted in the cartridge.
19. A method according to claim 18, wherein said ambient conditions
are reflective of a humidity value in said cartridge.
20. A method according to claim 18, wherein said photosensitive
media comprises microcapsules which encapsulate coloring material
and said development member comprises a pressure member which
applies a crushing force to said photosensitive media to crush said
microcapsules and develop the images, such that a force for
crushing the microcapsules is controlled based on the ambient
conditions in said cartridge as sensed by said ambient condition
sensor.
21. A method according to claim 18, wherein said ambient condition
sensor comprises: a spring plate attached to said cartridge; a
first contact plate having a first electrode, said first contact
plate being mounted on said spring plate; a sampling material
mounted on said first contact plate, said sampling material being
responsive to ambient conditions in said cartridge; and a second
contact plate having a second electrode, said second contact plate
being mounted on said sampling material.
22. A method according to claim 18, wherein said ambient conditions
is reflective of a humidity value in said cartridge.
23. A method according to claim 18, wherein said controlling step
further comprises controlling a light exposure of an imaging head
of the printer based on said ambient conditions.
24. A method according to claim 18, wherein said controlling step
further comprises controlling a temperature of a heater of said the
printer based on said ambient conditions.
25. A method according to claim 18, wherein said controlling step
further comprises controlling a printing speed of said printer
based on said ambient conditions.
26. A method according to claim 18, wherein said ambient condition
sensor comprises a substrate with conductive terminals and a
humidity sensitive material coated on the substrate.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] Reference is made to commonly assigned copending application
Ser. No. ______ [our Docket No. 81192], entitled AN IMAGE FORMING
DEVICE AND A METHOD OF PROCESSING PHOTOSENSITIVE MEDIA HAVING
MICROENCAPSULATED IMAGING MATERIAL, filed concurrently herewith in
the names of Loretta E. Allen, Yongcai Wang, Stephen M. Reinke and
YehHung Lai; and Ser. No. ______ [our Docket No. 81234], entitled
AN IMAGING ASSEMBLY AND MEDIA CARTRIDGE HAVING COOPERATING LINKAGE
ARRANGEMENTS, filed concurrently herewith in the names of Loretta
E. Allen, Yongcai Wang, Stephen M. Reinke and Yeh-Hung Lai.
FIELD OF THE INVENTION
[0002] The present invention relates to a photosensitive media
cartridge having an ambient condition sensor for sensing ambient
conditions within the cartridge. The present invention further
relates to an imaging arrangement in which imaging of
photosensitive material within an imaging device is controlled
based on ambient conditions within the cartridge.
BACKGROUND OF THE INVENTION
[0003] Image forming devices which process a photosensitive media
that includes microcapsules which encapsulate coloring material are
known. In these imaging devices the microcapsules are exposed to a
radiation based on image information. The microcapsules, whose
mechanical strength can change when exposed to light, are ruptured
by means of a crushing pressure, whereupon the coloring material
and other substances encapsulated in the microcapsules flow out and
development occurs. For example, some systems use a pair of upper
and lower nip rollers to apply pressure. In these systems, the
photosensitive media is passed between the pair of upper and lower
nip rollers which apply pressure to the microcapsules to rupture
the microcapsules and begin development. Imaging devices that
employ microencapsulted photosensitive compositions are disclosed
in U.S. Pat. Nos. 4,399,209, 4,416,966, 4,440,846, 4,766,050,
5,783,353, and 5,916,727.
[0004] A problem in processing photosensitive media having
microencapsulated color forming material is that printing and/or
imaging can be adversely affected by ambient conditions. That is,
ambient conditions around a printer housing, around the
photosensitive media, or in the cartridge which carries the
photosensitive media can adversely affect subsequent printing or
development of the image. More specifically, ambient conditions
such as humidity around the printer housing, at the photosensitive
media or in the cartridge which houses the photosensitive media can
have adverse affects on the chemicals of the coloring material, the
encapsulating material, and/or the photosensitive media. Further,
the degree of hardening or curing of the microcapsules and the
consequent increase in viscosity of the microcapsule varies with a
change in humidity. As a result, photographic characteristics such
as speed, minimum and maximum density, fogging density and full
color imaging can be adversely affected.
SUMMARY OF THE INVENTION
[0005] The present invention provides for a media cartridge as well
as an image forming device and method for processing photosensitive
media that overcomes the above-mentioned drawbacks. More
specifically, the present invention relates to an imaging device in
which light sensitive media that contains light sensitive,
rupturable microcapsules can be first exposed and then developed by
applying pressure to the light sensitive media. In the image
forming device of the present invention, print image quality can be
improved by sensing ambient conditions such as humidity in the
printer, directly from the media, or in the cartridge which carries
the media, and adjusting at least one adjustable parameter based on
the sensed ambient condition. As an example, in response to a
sensed humidity condition, a controller or development member of
the present invention can accordingly adjust the amount of pressure
applied to the microcapsules.
[0006] As indicated above, in the imaging device of the present
invention, the photosensitive medium contains light sensitive,
rupturable microcapsules that are exposed and then developed by the
application of pressure using a stylus or pinch rollers to rupture
unexposed microcapsules. Thereafter, the developed print is fixed
with heat supplied by a heater in the imaging device. In the
present invention, the level of relative humidity can be sensed
inside and/or outside of the printer, in the media cartridge or
directly on the photosensitive media, and then at least one of the
parameters of light exposure, developing pressure, printing speed
or fixing temperature can be adjusted automatically on the basis of
the relative humidity level to provide an improved image. As an
example, by adjusting the printing speed for a printer, the so
called "dark time" which is the time between exposure and
development will be changed. The dark time affects the hardness of
microcapsules and therefore their crushability. Also, within the
context of the present invention, the concept of sensing the level
of relative humidity on the photosensitive media refers to sensing
the moisture content on the photosensitive media or material.
[0007] The imaging device of the present invention also includes an
improved pressure assembly for applying a uniform pressure to the
photosensitive media.
[0008] The present invention relates to a photosensitive media
cartridge which comprises a housing for holding a stack of
photosensitive media; and an ambient condition sensor mounted
within the housing for sensing ambient conditions in the housing
and providing an ambient condition signal indicative thereof,
wherein a development of the photosensitive media is based on the
sensed ambient condition. The ambient condition signal can also be
indicative of rh storage levels of the photosensitive media.
[0009] The present invention further relates to an image forming
arrangement which comprises an image forming device for forming a
latent image on a photosensitive medium, with the photosensitive
medium comprising a plurality of microcapsules which encapsulate
imaging material. The image forming device comprises a pressure
assembly for applying an initial pressure to the photosensitive
medium to crush the microcapsules and develop a latent image on the
photosensitive medium. The arrangement further includes a media
cartridge for holding a stack of the photosensitive medium therein,
with the media cartridge being adapted to be inserted into the
image forming device to permit a conveyance of the photosensitive
medium to the image forming device. The media cartridge comprises
an ambient condition sensor mounted within the cartridge for
sensing ambient conditions within the cartridge and providing an
ambient condition signal indicative thereof to the pressure
assembly, such that an amount of pressure applied by the pressure
assembly is based on the ambient conditions sensed by the ambient
condition sensor in the cartridge.
[0010] The present invention further relates to a method of
controlling image development which comprises the steps of:
providing an ambient condition sensor in a cartridge which holds
photosensitive media therein, with the ambient condition sensor
sensing ambient conditions within the cartridge and providing an
ambient condition signal indicative thereof to a development member
of a printer; inserting the cartridge to an insertion position in
the printer which permits a passage of photosensitive media from
the cartridge to the development member in the printer; and
controlling a development of images on the photosensitive media
based on the ambient condition signal received from the ambient
condition sensor mounted in the cartridge.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 schematically illustrates an image forming device in
accordance with the present invention;
[0012] FIG. 2 schematically illustrates a microprocessor for
controlling the operation of the image forming device of FIG.
1;
[0013] FIG. 3(a) illustrates a first embodiment of a pressure
applying assembly of the image forming device of the present
invention;
[0014] FIG. 3(b) is a side view of the pressure applying assembly
of FIG. 3(a).
[0015] FIG. 3(c) is a further view of the pressure applying
assembly of FIG. 3(a);
[0016] FIG. 4(a) is a view of a second embodiment of a pressure
applying assembly of the image forming device of the present
invention;
[0017] FIG. 4(b) is a side view of the pressure assembly of FIG.
4(a);
[0018] FIGS. 4(c)-4(d) are further views of the pressure applying
assembly of FIG. 4(a);
[0019] FIGS. 5(a)-5(b) are views of a further embodiment of a
pressure applying assembly of the image forming device of the
present invention;
[0020] FIG. 6(a) shows a device for sensing ambient conditions in a
photosensitive media cartridge in accordance with a feature of the
present invention;
[0021] FIG. 6(b) shows another device for sensing ambient
conditions in a photosensitive media cartridge in accordance with a
feature of the present invention;
[0022] FIG. 6(c) shows another device for sensing moisture content
in a photosensitive media in accordance with feature of the present
invention;
[0023] FIG. 7 is a further embodiment of the present invention
including a linkage assembly within a photosensitive media
cartridge for adjusting a pressure applied to the photosensitive
media during development;
[0024] FIGS. 8(a)-8(b) are detailed views of the linkage assembly
and its cooperation with a pressure applying assembly of an image
forming device;
[0025] FIGS. 9 and 10 illustrate further features of the linkage
assembly of FIG. 7;
[0026] FIGS. 11(a)-11(b) illustrate further features of the image
forming device of the present invention including the use of a
pressure strip; and
[0027] FIG. 12 is a side view of the pressure strip of FIGS. 11(a),
11(b).
DETAILED DESCRIPTION OF THE INVENTION
[0028] Referring now to the drawings, wherein like reference
numerals represent identical or corresponding parts throughout the
several views, FIG. 1 is a schematic view of an image forming
device 15 of the present invention. Image forming device 15 could
be, for example, a printer that includes an opening 17 which is
adapted to receive a cartridge containing photosensitive media. As
described in U.S. Pat. No. 5,884,114, the cartridge could be a
light tight cartridge in which photosensitive sheets are piled one
on top of each other. When inserted into image forming device 15, a
feed mechanism which includes, for example, a feed roller 21a in
image forming device 15, working in combination with a mechanism in
the cartridge, cooperate with each other to pull one sheet at a
time from the cartridge into image forming device 15 in a known
manner. Once inside image forming device 15, photosensitive media
travels along media path 19, and is transported by, for example,
drive rollers 21 connected to, for example, a driving mechanism
such as a motor. The photosensitive media will pass by an imaging
head 25 which could include a plurality of light emitting elements
that are effective to expose a latent image on the photosensitive
media based on image information. After the latent image is formed,
the photosensitive media is conveyed pass a development member such
as a pressure applicator or pressure assembly 27, where an image
such as a color image is formed based on the image information by
applying pressure to microcapsules having imaging material
encapsulated therein to crush the microcapsules. Within the context
of the present invention, the imaging material comprises a coloring
material (which is used to form images) or material for black and
white media. After the formation of the image, the photosensitive
media is conveyed pass a heater 29 for fixing the image on the
media. In a through-feed unit, the photosensitive media could
thereafter be withdrawn through an exit 32. As a further option,
image forming device 15 can be a return unit in which the
photosensitive media is conveyed or returned back to opening
17.
[0029] In a feature of the present invention, image forming device
15 includes a microprocessor or controller 30, illustrated in
detail in FIG. 2. Controller 30 is effective to control several
printing parameters with respect to the development of the image on
the photosensitive media. For example, controller 30 can control
parameters such as light exposure, pressure application, fixing
temperature, printer motor speed, etc.
[0030] With reference to FIG. 2, a first feature of image forming
device 15 and controller 30 of the present invention is the control
of printing conditions based on sensed ambient conditions. More
specifically, controller 30 is adapted to be responsive to ambient
conditions to provide a pressure increasing or pressure decreasing
signal to pressure assembly 27 to control the amount of pressure or
crushing force applied by pressure assembly 27.
[0031] In one example of the invention as illustrated in FIG. 2,
controller 30 is operationally associated with an ambient condition
sensor which senses ambient conditions within image forming device
15. As shown in FIG. 2, the ambient condition sensor can be a
humidity sensor 33 which senses humidity conditions within image
forming device 15. As will be explained in detail later, the
present invention is not limited to sensing the humidity within
image forming device 15. It is noted that the humidity can be
sensed outside of image forming device 15. It is further noted that
the humidity can be sensed within a photosensitive media cartridge
and/or directly from the photosensitive media itself. For example,
humidity or moisture content can be sensed directly from the media
itself by measuring an IR absorption band of water within the media
and comparing it to a reference value stored in controller 30. This
is commonly called Near Infrared Spectroscopy, and can be done by
sampling the media as it travels through the printer. As an
example, U.S. Pat. No. 4,345,150 describes a method and apparatus
for generating signals corresponding to the moisture content of
paper by irradiating a sheet of paper with a near infrared ray, by
detecting a beam having a coaction with the paper and accomplishing
the desired arithmetic operations with the use of the detected
signals.
[0032] Once the humidity is sensed by humidity sensor 33, a signal
indicative thereof is sent to a look up table 34. Look up table 34
can include a plurality of reference humidity values which are
compared to the sensed humidity value. Within the context of the
present invention, the term reference humidity value refers to a
humidity level or more preferably, a response curve (printing
pressure vs. humidity). As a further option, rather than using a
look-up table, an equation or a direct circuit can be utilized.
Once this comparison is made, controller 30 can drive a drive
circuit 35 for controlling the pressure application by pressure
assembly 27. As an example, it is beneficial to apply a larger
amount of pressure when a sensed humidity is high (for example,
higher than a reference humidity value of 30%) and to reduce the
pressure applied to the photosensitive material when the sensed
humidity is low (for example, lower than a reference humidity value
of 30%). Of course, it is noted that the present invention is not
limited to the above-reference humidity value. It is noted that the
reference humidity value can be any value which is set based on a
desired result. As an example, a reference humidity value which
provides consistent sensitometric properties can be used.
[0033] As a further example, it is beneficial to reduce the
pressure applied to the photosensitive material, or increase the
level of light exposure, or to reduce the printing speed when the
sensed humidity is low. These changes can be done according to
precalibrated information stored in the printer or stored on the
cartridge through a barcode. Under certain conditions, it is
desirable to change several parameters simultaneously according to
the humidity information to optimize the printing conditions.
[0034] The precalibrated information for a given type of media can
be obtained by testing the sensitometric characteristics of the
media as a function of, for example, printing pressure or light
exposure level. The details of response of printing pressure to
humidity depend on the media. But it is in general theorized that
the mechanical properties of a microcapsule containing layer
changes with humidity which is turn changes the response of the
microcapsule containing layer to printing pressure. For example, if
the microcapsule containing layer is rigid at lower humidity (e.g.
30% RH) the microcapsules are more easily ruptured. If the
microcapsule layer becomes more flexible at high humidity (e.g.
80%RH) the microcapsules are more difficult to rupture. This may
change the amount of coloring materials released by the
microcapsules during the printing process. Thus, the reference
humidity depends on the type of media and level of light
exposure.
[0035] Therefore, if the sensed humidity is higher than the
reference humidity value, the drive circuit will provide a signal
to pressure assembly 27 to increase the amount of pressure applied
to the photosensitive medium, and if the humidity value is lower,
the drive circuit will provide a signal to pressure assembly 27 to
reduce the amount of pressure applied to the photosensitive
medium.
[0036] As also indicated above, controller 30 is adapted to control
features of imaging head 25, heater 29, as well as a motor 37 for
driving rollers 21 and conveying media 47 through image forming
device 15 to control printing speed. As a further option, these
features could also be controlled based on the sensed humidity
value. Further features of image forming device 15 and controller
30 include the provision of a control panel 41 to enable user
control of image forming device 15, an image card 39 which can
include image information with respect to the image which is to be
developed and printed, and a display 80 for displaying information,
such as image information or the sensed humidity value.
[0037] As a further option, images which are to be printed by image
forming device 15 can be transferred or uploaded to image forming
device 15 by way of the Internet or a computer. For example, as
shown in FIG. 2, image forming device 15 or controller 30 can
include a modem 800 for communication to a network service provider
801 such as the Internet. This permits a transfer of images to
image forming device 15 from the Internet for subsequent printing.
As a further example, image forming device 15 or controller 30 can
include a PC interface 803 in communication with a computer 805
such as a personal computer. This permits the transfer of images
stored in computer 805 to image forming device 15 for subsequent
printing. As a further option, computer 805 can be communicated to
Network service provider 801 to download images from the Internet
to image forming device 15 via computer 805.
[0038] FIGS. 3(a), 3(b) and 3(c) illustrate different views of a
first embodiment of pressure assembly 27 in accordance with the
present invention. The pressure assembly is identified in FIGS.
3(a)-3(c) by reference numeral 27a. Pressure assembly 27a is a
crushing roller and beam arrangement which provides a point contact
on the photosensitive medium. More specifically, pressure assembly
27a includes a slide 45 which extends along a width-wise direction
of a photosensitive medium 47. Moveably mounted on slide 45 is a
crushing roller arrangement 49 which is adapted to move along the
length of slide 45, i.e., across the width of photosensitive medium
47. Crushing roller arrangement 49 is adapted to contact one side
of photosensitive medium 47. A beam 51 is positioned on an opposite
side of photosensitive medium 47. Beam 51 is positioned so as to
contact the opposite side of photosensitive medium 47 and is
located opposite crushing roller 49. Beam 51 and crushing roller 49
when in contact with photosensitive medium 47 on opposite sides
provide a point contact on photosensitive medium 47. Crushing
roller 49 is adapted to move along a width-wise direction of
photosensitive material 47 so as to crush microcapsules, release
coloring material, and process image information such as image
information provided by image card 39.
[0039] Extending from beam 51 is an arm 53 having an extension or
seat portion 55. Also provided on beam 51 are compression springs
57 which urge beam 51 into contact with a lower side of
photosensitive medium 47. It is further noted that beam 51 and arm
53 are pivotally mounted at a pivot point 59 so as to be movable or
rotatable about pivot point 59 as illustrated by arrow 61. Thus,
compression spring 57 urges beam 51 and arm 53 in a clockwise
direction about pivot point 59, so as to urge beam 51 into contact
with the lower surface of media 47. In a further feature of
pressure assembly 27a as illustrated in FIGS. 3(a)-3(c), an
electromagnet 60 is positioned adjacent to extension 55.
[0040] Thus, compression spring 57 urges beam 51 in a clockwise
direction so as to place beam 51 in a pressure applying position.
Electromagnet 60 mounted to a printer frame (not shown) applies an
initial attraction force to extension 55 and arm 53 so as to help
maintain beam 51 in the pressure applying position. As illustrated
in FIG. 2, pressure assembly 27a receives a signal from controller
30. In the embodiment of FIGS. 3(a)-3(c), electromagnet 60 is
operationally connected to controller 30 via drive circuit 35.
[0041] An operation of pressure assembly 27a will now be described.
With reference to FIGS. 1 and 2, in one embodiment of the
invention, a humidity within the housing of image forming device 15
is sensed by humidity sensor 33. This provides a signal to look up
table 34 within controller 30. If the sensed humidity is above a
humidity reference value or response curve, a pressure increasing
signal will be applied to drive circuit 35 so as to increase the
pressure applied by assembly 27a. More specifically, in response to
a pressure increasing signal, controller 30 will interact with
electromagnet 60 to increase the attraction force on extension 55
and in turn on arm 53, and therefore increase the initial
attraction force to further pivot arm 53 and beam 51 in the
clockwise direction towards photosensitive media 47. This increases
the pressure applied by beam 51 on photosensitive media 47, and
increases the crushing force applied to the microcapsules via beam
51 and crushing roller 49. If the humidity sensed by humidity
sensor 33 is below a reference humidity value, controller 30 will
provide a signal to drive circuit 35 to decrease the pressure
applied by pressure assembly 27a. In this scenario, controller 30
will interact with electromagnet 60 to reduce the attraction force
back to the initial attraction force. Thus, when electromagnet 60
receives a signal from controller 30 indicating that the sensed
humidity is lower than a reference humidity, a pressure decreasing
signal is provided by controller 30 to electromagnet 60. The signal
causes electromagnet 60 to reduce the attraction force against arm
53 back to the initial attraction force, and thus return beam 51
and arm 53 to its initial pressure applying position.
[0042] FIGS. 4(a)-4(d) illustrate different views of a second
embodiment of pressure assembly 27 of the present invention. The
pressure assembly in FIGS. 4(a)-4(d) is referenced by reference
numeral 27b. In the embodiment of FIGS. 4(a)-4(d), photosensitive
media 47 including rupturable microcapsules are first exposed as
described with reference FIG. 1, and then developed by pressure
pinch rollers 61, 63 which form a nip as illustrated in FIG. 4(b).
The embodiment of FIGS. 4(a)-4(d) illustrates a roller contact on
each side of photosensitive media 47. In the embodiment of FIGS.
4(a)-4(d) one of the rollers (roller 63) includes a fixed axis 63a,
and the other roller (roller 61) includes a floating axis 61a.
Rollers 61 and 63 are mounted on a full length clamping spring 67
which has a fixed part or section 67b onto which roller 63 is
rotatably mounted, and an adjustable part or section 67a onto which
roller 61 is rotatably mounted. Fixed section 67b includes a slot
67c to permit the passage of photosensitive material therethrough.
In a feature of the invention as illustrated in FIGS. 4(a)-4(d),
clamping spring 67 forms a toggle which permits an increase or
decrease in the pressure applied to roller 61 having floating axis
61 a. Clamping spring 67 further permits a uniform application of
pressure at the nip of the first and second rollers 61 and 63
across an entire width of photosensitive medium 47, and maintains
the first and second rollers 61 and 63 in a pressure applying
position.
[0043] As described above, clamping spring 67 has a section 67b
which rotatably holds roller 63 so that roller 63 has a fixed
rotational axis 63a. The other section 67a of clamping spring 67
rotatably holds roller 61 so that roller 61 has an adjustable axis
61a that is movable toward and away from roller 63. In one feature
of the present invention, in order to move section 67a of clamping
spring 67, an electromagnet 65 is mounted or placed in the vicinity
of section 67a of clamping spring 67. Magnet 65 is operationally
associated with controller 30 for controlling the positioning of
roller 61 with respect to roller 63.
[0044] Therefore, in the same manner as the embodiment of FIGS.
3(a)3(c), if a humidity within the housing sensed by humidity
sensor 33 is below a reference humidity as stored in look-up Table
34 (FIG. 2), a pressure decreasing signal is provided from
controller 30 to drive circuit 35, so as to cause pressure assembly
27b to reduce the pressure applied to photosensitive media 47. That
is, controller 30 will interact with magnet 65 to apply a magnetic
force to section 67a of clamping spring 67 and reduce the force
roller 61 applies to roller 63.
[0045] If the humidity sensed by humidity sensor 33 is greater than
a reference humidity value or response curve as stored in look-up
Table 34, controller 33 provides a signal to drive circuit 35 to
increase the pressure applied by pressure assembly 27b. In this
mode, controller 30 will provide a signal to magnet 65 to reduce
the attractive force acting on clamping spring 67a and urge roller
61 further into contact with roller 63. This increases the pressure
applied on photosensitive medium 47.
[0046] FIGS. 5(a)-5(b) illustrate different views of a further
embodiment of pressure assembly 27. In FIGS. 5(a)-5(b), the
pressure assembly is identified by reference numeral 27c. As
illustrated in FIGS. 5(a)-5(b), pressure assembly 27c includes beam
51 and arm 53 which are movable about pivot point 59 as in the
embodiment of FIGS. 3(a)-3(c). Beam 51 contacts one side of
photosensitive material 47. On the opposite side of photosensitive
material 47 slide 45 provides a guide for crushing roller 49 so as
to guide crushing roller 49 across the width of photosensitive
material 47, as also described with reference to FIGS. 3(a)-3(c).
Pressure assembly 27c in FIGS. 5(a)-5(b) differs from pressure
assembly 27a illustrated in FIGS. 3(a)-3(c) with respect to using
the combination of a stepper motor 75 and a spring 73 as opposed to
an electromagnet. More specifically, as shown in FIGS. 5(a)-5(b),
pressure assembly 27c includes an extension portion 70 which
extends from arm 53, onto which is mounted extension spring 73. A
cable 77 leads from extension spring 73 and is wrapped around a
pulley 75a of stepper motor 75. Therefore, in the embodiment of
FIGS. 5(a)-5(b), stepper motor 75 can vary the pulley rotational
position and the attached cable 77 to result in a varying length of
extension spring 73. By pulling down on extension spring 73, the
crushing roller force on the media by beam 51 is reduced.
[0047] More specifically, in response to a high humidity signal
from controller 30 in which the measured humidity is higher than a
reference humidity as described with respect to FIGS. 3(a)-3(c),
controller 30 provides a pressure increasing signal to stepper
motor 75. This causes stepper motor 75 to rotate in a counter
clockwise direction so as to urge beam 51 and arm 53 in a clockwise
rotation about pivot 59. This causes an increase in the force
applied by beam 51 onto photosensitive media 47. In the event that
the humidity sensed is lower than a reference humidity, a pressure
decreasing signal is provided by controller 30. Therefore,
controller 30 will interact with stepper motor 75 to rotate stepper
motor 75 in a clockwise direction so as to pull down arm 53 and
beam 51 and rotate beam 51 and arm 53 in a counter clockwise
direction about pivot 59. This serves to reduce the amount of
crushing force applied by beam 51 onto photosensitive media 47.
Further, as in the embodiment of FIGS. 3(a)-3(c), a compression
spring 57 is provided on beam 51, so as to maintain an initial
pressure of beam 51 onto photosensitive media 47.
[0048] The present invention has thus for been described with
respect to measuring ambient conditions such as humidity within the
housing of image forming device 15. As previously indicated, the
present invention is not limited to such an arrangement. For
example, as a further option, the humidity within a cartridge which
holds photosensitive media that is to be fed into image forming
device 15 can be sensed. FIG. 6(a) illustrates one embodiment for
sensing humidity within a cartridge.
[0049] More specifically, FIG. 6(a) is an exploded view of a
cartridge 85 that holds photosensitive media 47'. Media 47' could
be of the type having microcapsules with coloring material. As
shown in FIG. 6(a), media cartridge 85 defines a housing having top
and bottom sections 85a, 85b which can snap together to house media
47' therein, one on top of the other. Cartridge 85 further includes
a light-lock door 85c. Cartridge 85 and more specifically, one of
the sections 85a, 85b of cartridge 85 includes a humidity sensor 87
which comprises a first spring plate 89 that is adapted to be
mounted on, for example, section 85b. Mounted on spring plate 89 is
a first contact plate 90 having a first electrode 91 and a second
contact plate 95 having a second electrode 97. Sandwiched between
first and second contact plates 90 and 95 is a sampling member or
dielectric layer 93. Sampling member 93 could be a material which
is successible or responsive to humidity conditions within
cartridge 85. An example of this could be a salt solution
impregnated fabric or various hydrophilic polymers.
[0050] Therefore, in the arrangement of FIG. 6(a), electrodes 97
and 91 provide for a capacitor and the measured humidity is a
function of capacitance. Electrodes 97 and 91 protrude through
cut-outs in spring plate 89 to make physical contact between sensor
87 located within cartridge 85 and controller 30 located within
image forming device 15. Based on the signal from humidity sensor
87, controller 30 controls the application of pressure by way of
pressure assembly (27a, 27b, 27c) in the manner described with
respect to FIGS. 3(a)-3(c); 4(a)-4(d); and 5(a)-5(b). Humidity
sensor 87 as illustrated in FIG. 6(a) can replace humidity sensor
33 in the housing of image forming device 15 or be used in addition
to sensor 33. As previously described, a higher humidity would
provide a signal to increase the pressure applied by either one of
pressure assemblies 27a, 27b or 27c, while a lower humidity would
provide a signal to controller 30 to control the pressure
assemblies to lower the crushing pressure. Thus, the combination of
the cartridge and the image forming device would provide for an
image forming assembly or arrangement.
[0051] FIG. 6(b) illustrates another embodiment for sensing
humidity within a cartridge. More specifically, FIG. 6(b) is an
exploded view of a cartridge 85 that holds photosensitive media
47'. Media 47' could be of the type having microcapsules with
coloring material. As shown in FIG. 6(b), media cartridge 85
defines a housing having top and bottom sections 85a, 85b which can
snap together to house media 47' therein, one on top of the other.
Cartridge 85 and more specifically, one of the sections 85a, 85b of
cartridge 85 includes a humidity sensor 87' which comprises a
substrate 500 with interdigitated conductive terminals on the
substrate overcoated with a humidity sensitive material such as a
hydrophilic polymer. Humidity effects the electrical properties of
the polymer and the relative humidity can be obtained directly from
the equivalent resistance or conductance of the sensor. Electrodes
91' and 97' protrude through cut-outs in spring plate 89' to make
physical contact between sensor 87' located within cartridge 85 and
controller 30 located within image forming device 15.
[0052] FIG. 6(c) illustrates an embodiment for sensing moisture
content of photosensitive media 47'. Media 47' could be of the type
having microcapsules with coloring material. As shown in FIG. 6(c),
photosensitive media 47' is drawn out of cartridge 85 into image
forming device 15. A device 600 to measure the moisture content of
photosensitive media 47' is positioned within image forming device
15, and in the media path between the exit of cartridge 85 and
imaging head 25 (see, for example, U.S. Pat. No. 4,345,150). Device
600 to measure the moisture content of media 47' comprises a near
infrared light source 600a to irradiate media 47' having a first
wavelength which is more absorbed by the moisture and a reference
wavelength which is less absorbed by the moisture, a detecting
arrangement 600b and a processor 600c. Based on the signal from
processor 600c, controller 30 controls the application of pressure
by way of pressure assembly (27a, 27b, 27c).
[0053] FIGS. 7, 8(a), 8(b), 9 and 10 illustrate a further
embodiment of the present invention. More specifically, FIGS. 7,
8(a) and 8(b) illustrate an apparatus for adjusting a crushing
roller force which instead of utilizing an electromagnetic or
extension spring driven by a stepper motor as described, utilizes a
linkage assembly within a media cartridge. FIG. 7 illustrates a
cartridge 100 which holds a stack of media 101. Cartridge 100 in
FIG. 7 includes a linkage assembly or mechanism 103 which includes
sections that are pivoted at a pivot point 105. Cartridge 100
includes an access slot 109 which permits a knob 107 attached to a
link section 103c of linkage assembly 103 to extend therethrough.
When inserted into an image forming device or printer 200 (similar
to image forming device 15 as described), area 111 of cartridge 100
will be inserted into the printer so as to define an inserted
position in which media from cartridge 101 is conveyed into printer
200. Furthermore, it is noted that cartridge 100 includes a light
lock door end to prevent light from entering into cartridge 100.
With reference to FIGS. 910, in order to be responsive to humidity
conditions inside of cartridge 100, linkage assembly 103 further
includes link sections 103a, 103b which are linked at pivot point
105 and can be made of a material, for example, nylon, that expands
at high humidity. Link section 103c including knob 107 is attached
to link sections 103a, 103b via pivot point 105 and although not
required, linkage section 103c can also be made out of a material
that expands.
[0054] Therefore, under low humidity conditions as illustrated in
FIG. 9, linkage assembly 103 will remain at a rest position and
thus knob 107 will not extend through slot 109. When humidity in
media cartridge 100 increases above a predetermined value linkage
sections 103a, 103b will expand, and therefore, pivot about pivot
point 105 which is a moving pivot point, as well as pivot points
105a 105b which are fixed. This will increase a toggle angle
.alpha. as illustrated in FIG. 9 from a first value, to a second
value .alpha.' as illustrated in FIG. 10 which is larger than
.alpha.. This causes link section 103c to move upward causing knob
107 to extend through slot 109 as illustrated in FIG. 10. In
general, link sections 103a, 103b should be made of a material that
expands in length by approximately a value of 0.5%.
[0055] With the use of the embodiment of FIGS. 7-10, printer 200
will include a lever assembly 201 (FIGS. 8(a)-8(b)) which
cooperates with linkage assembly 103 to adjust the crushing force
on the microcapsules of the photosensitive media. More
specifically, with reference to FIGS. 8(a)-8(b), lever assembly 201
in printer 200 includes a printer link 203 movably attached to a
lever arm 205 by way of a spring 207. Printer link 203 includes a
knob 203a which cooperates with knob 107 of linkage assembly 103.
Printer link 203 rests against a stop 209 (before cartridge 100 is
inserted into printer 200) and further includes a spring 211 to
control movement of link 203.
[0056] Lever arm 205 is analogous to lever arm and beam arrangement
described in, for example, FIGS. 3(a)-(3c). More specifically,
lever arm 205 includes a beam 215 which abuts against a surface of
photosensitive media 219 and forms a flat nip with a crushing
roller 217 in the same manner as described, with respect to, for
example, FIGS. 3(a)-3(c). Lever arm 205 and beam 215 are upwardly
urged by way of a main spring 220. As also illustrated in FIGS.
8(a)8(b), printer link 203 is pivoted at point 221, while lever arm
205 is pivoted at point 222.
[0057] Therefore, under low humidity conditions as illustrated in
FIG. 9, linkage assembly 103 will remain at a rest position, such
that knob 107 does not extend through slot 109. In this position,
knob 203a will rest on knob 107, and will not apply an additional
upward force onto lever arm 205. Thus, lever arm 205 and beam 215
will apply an initial force or a reduced force onto photosensitive
media 219 by way of main spring 220. When the humidity increases as
illustrated in FIG. 10, linkage sections 103a, 103b will expand to
thus increase toggle angle .alpha. to .alpha.' and move pivot point
105 upward. Movement of pivot point 105 upward will move link
section 103c upward to extend knob 107 through slot 109 so as to
urge knob 203a upwardly. The urging of knob 203a upwardly will move
printer link 203 in a clockwise direction about pivot point 221 to
urge spring 207 upward. The urging of spring 207 upward will urge
lever arm 205 and beam 215 in a clockwise direction about pivot
point 222, so as to provide a further force against photosensitive
media 219 by beam 215, and therefore increase the amount of
crushing force applied to photosensitive media 219.
[0058] Thus, the embodiment of FIGS. 7-10 provides for a mechanical
method of adjusting the printing force based on humidity within the
media cartridge. The linkage fits inside of the cartridge within
the side of the media cartridge and provides a means for adjusting
a lever within the printer, which in turn adjusts a printing roller
force. Further, the combination of the cartridge and the image
forming device would provide for an image forming assembly or
arrangement.
[0059] FIGS. 11(a), 11(b) and 12 illustrate a further embodiment of
the present invention. With respect to utilizing a crushing force
on photosensitive media having microcapsules by way of crushing
rollers and a beam, there is a possibility of marking the media. In
the embodiment of FIGS. 11(a), 11(b) and 12, a pressure strip 300
made out of, for example, a polyester such as polyethylene
terephtalate material can be used. As an example, pressure strip
300 can be approximately 0.006 inches thick. Pressure strip 300
would be provided between crushing roller 301 and photosensitive
media 303 with beam 305 being provided on the opposite side of
media 303. Pressure strip 300 would also extend beyond the
widthwise edges of media 303. During printing, crushing roller 301
travels along a widthwise direction of photosensitive media 303 and
travels outside the edges of photosensitive media 303. Without
flexible strip 300, the edges of the media would provide for a step
for the crushing roller as the crushing roller extends from a
section 307 above the beam which does not include the
photosensitive media 303 to a section above the beam which includes
photosensitive media 303 therebetween or vice versa. The provision
of pressure strip 300 between crushing roller 301 and
photosensitive media 303 provides for a smooth passage for crushing
roller 301 over photosensitive media 303, and in addition, provides
for a smooth transition between the section 307 which does not
include photosensitive media 303, i.e., outside the edges of
photosensitive media 303, and the section which includes media 303.
Therefore, when crushing roller is placed at, for example, a
parking area or shoulder outside the edges of photosensitive media
303 (section 307), flexible strip 300 provides for a bridge between
section 307 and photosensitive media 303. Further, the addition of
pressure strip 300 permits a fall width imaging to be performed as
opposed to performing imaging only within a border of the media.
More specifically, crushing roller 301 including pressure strip 300
positioned thereunder, is designed to crush media to the edge of
the media and move beyond the edge for indexing the media. Flexible
pressure strip 300 provides a bridge for crushing roller 301 to
roll over with a minimal gap 3000 (FIG. 11(a)) and low force.
[0060] In a further feature of the invention as illustrated in FIG.
12, crushing roller 301 can be mounted onto a leaf spring 310 to
apply crushing pressure onto photosensitive media 303. Leaf spring
310 can be attached to crushing roller 301 to slide with the
crushing roller 301 along the widthwise direction of the
photosensitive media 303, while applying a crushing force onto
media 303.
[0061] In a further feature of the invention, flexible pressure
strip 300 could be fixed at each widthwise end to prevent unwanted
movement of the strip. Also, strip 300 could be made of a low
friction wear material.
[0062] In a still further feature of the invention, the light
exposure by imaging head 25 or the temperature of heater 29 can be
adjusted (see, for example, EP 08644301 A1). In the present
invention, the adjustment of the light exposure or the temperature
would be based on the humidity sensed by sensor 33 (FIG. 1); sensor
87 (FIG. 6(a)); sensor 87' (FIG. 6(b)) or device 600 (FIG. 6(c)).
In this scenario, the value of the current or voltage which is
supplied to the LED's of the imaging head or the heating element of
the heater would be adjusted based on the sensed humidity
value.
[0063] In a still further feature, as previously described,
printing speed can be adjusted based on the sensed humidity
condition. In this scenario, controller 30 can provide a signal to
motor 37 to control the printing speed based on the measured
humidity.
[0064] The invention has been described in detail with particular
reference to certain preferred embodiments thereof, but it will be
understood that variations and modifications can be effected within
the spirit and scope of the invention.
* * * * *