Card printer

Information

  • Patent Grant
  • 6755520
  • Patent Number
    6,755,520
  • Date Filed
    Monday, September 23, 2002
    22 years ago
  • Date Issued
    Tuesday, June 29, 2004
    20 years ago
Abstract
A guide 63 for guiding a card 10 to a printing unit 50, and guides 62, 61 for guiding the card from the printing unit 50 to a storage chamber for temporary storage, are integrally formed to a frame 30 having an integrally formed opening-shaped mounting unit 32 for fastening a printing unit 50 for printing and transporting the card 10, and a flat mounting surface 31c for fastening a control board for controlling the printing unit 50. The card printer is configured by housing the frame 30 in cases 20, 40, but because the major members and components are integrally formed or fastened to the card 10, disassembly and assembly can be easily accomplished.
Description




FIELD OF TECHNOLOGY




The present invention relates to a card printer capable of printing on stiff cards such as prepaid cards.




1. Related Art




Information systems for centrally managing in one place information recorded to prepaid cards such as telephone cards, for example, have been developed in recent years, and a prepaid card usage count linked to the pass code assigned to the prepaid card is counted in this system.




In conjunction with this, card printers for recording information such as the pass code and usage count to prepaid cards are also being developed.




2. Summary of the Invention




Applications using such card printers in combination with credit card authorization terminals (“CAT” below) to issue prepaid cards with payment made by credit card have been proposed, but because the CAT is generally small, it is also desirable to make the card printer compact.




Furthermore, a problem with this type of card printer is that it must be able to transport stiff cards without slipping, and must prevent chafing the recording surface during transportation.




Furthermore, because prepaid cards are printed frequently and in large numbers, it is also necessary to consider the ease of disassembly and assembly for such as replacing and servicing the print head, control board, and other functional components. Yet further, it is also necessary to consider the ease of disassembly and assembly in order to remove a card when it becomes stuck in the part for temporarily holding the card.




The present invention is directed to a solution for these problems, and an object of the invention is to provide a card printer that is small and compact, can transport cards without slipping and without damaging the recording surface thereof, and is easy to handle.




A further object of the present invention is to provide a card printer that is easy to disassemble and assemble.




A card printer according to the present invention is a card printer comprising a printing unit having a print head for printing to a card, a roller for transporting the card, and a motor for driving the roller; a control board for controlling the printing unit; and a frame having an integrally formed opening-shaped mounting unit for installing the printing unit, and a flat mounting surface for installing the control board; integrally formed to the frame are a first guide disposed to an edge of the opening-shaped mounting unit for guiding the card between the print head and roller; a second guide disposed at a specific angle to the first guide on an edge on a side opposite the edge to which the first guide is disposed; and a third guide disposed proximally to the second guide for guiding a card transported by the roller to a back side of the flat mounting surface.




Because the printing unit for printing and transporting cards, the control board for controlling the printing unit, the guides for guiding cards transported by the printing unit, and other major members and components are integrally formed or fastened to the frame with the present invention, the major members and components can be removed en masse by opening the case and removing the frame from the case. That is, disassembly and assembly can be easily accomplished.




Furthermore, because the first guide disposed to an edge of the opening-shaped mounting unit for guiding the card between the print head and roller is inclined at a specific angle to the second guide disposed to an edge on a side opposite the edge to which the first guide is disposed, cards are transported wrapped a certain angle to the roller. Stiff cards can therefore be transported without slipping.




Further preferably, a wall forming part of a storage chamber for temporarily housing a card transported by the roller is disposed to the back side of the mounting surface provided for mounting the control board. When the roller is rotated to transport a card, the card guided by the second guide is further guided by a third guide to a storage chamber formed on the back side of the control board.




The case housing the frame comprises, for example, a top and bottom pair of cases. In this case the storage chamber is preferably formed between the bottom case and the wall of the frame. As a result, if a card becomes stuck in the storage chamber for some reason, the card can be easily removed from the storage chamber by removing the case from the frame.




Furthermore, the surface of the second guide preferably projects to said wall side from a printing surface defined by the print head and roller.




By projecting the second guide from the printing surface, the leading edge of the card curves to the wall (storage chamber ceiling) side of the frame. Therefore, the leading edge is urged to the wall side of the frame by the stiffness of the card itself as the card is transported to the storage chamber. As a result, the card is transported without the recording surface thereof being rubbed by members of the storage chamber. It should be noted that this wall is preferably formed substantially parallel to the printing surface in this case.




When the case for housing the frame is comprised of a top and bottom pair of cases, auxiliary guides such as shown below can be disposed to the top case.




For example, a comb-shaped fourth guide is preferably disposed to the top case so as to mesh alternately in part with the third guide when the frame is housed in the case. As a result, when a card is transported, the leading edge of the card guided by the second guide is guided to the storage chamber formed on the back side of the control box by both the third and fourth guides. It should be noted that in this case part of the fourth guide may be positioned opposite the second guide.




In addition, an insertion opening for inserting a card and a fifth guide positioned adjacent to the insertion opening can be disposed to the top case with the fifth guide positioned so that it is opposite the first guide when the frame is housed in the case.




In addition to the printing unit and guides for guiding cards transported thereby, detectors for detecting presence of a card may be disposed to the frame. These detectors can, for example, be disposed to the first guide or second guide.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is an oblique view showing the appearance of a card printer according to a preferred embodiment of the present invention.





FIG. 2

is an oblique view looking at the inside of the top case of the card printer shown in FIG.


1


.





FIG. 3

is an oblique view looking at the bottom of the frame housed inside the card printer shown in FIG.


1


.





FIG. 4

is an oblique view looking at the inside of the bottom case of the card printer shown in FIG.


1


.




FIGS.


5


(


a


) is an oblique view showing the basic configuration of the printing unit, and (


b


) is an oblique view showing the printing unit mounted to the frame shown in FIG.


3


.





FIG. 6

is a side view showing the basic configuration of the card printer shown in FIG.


1


.





FIG. 7

is an enlarged view showing essential parts in FIG.


6


.





FIG. 8

is a descriptive view illustrating paper transportation in the card printer shown in

FIG. 1

, and shows a card inserted to the insertion opening.





FIG. 9

is a descriptive view showing the leading edge of the card advanced to the second guide in FIG.


8


.





FIG. 10

is a descriptive view showing the leading edge of the card advanced to the fourth guide in FIG.


8


.





FIG. 11

is a descriptive view showing the leading edge of the card advanced to the third guide in FIG.


8


.





FIG. 12

is a descriptive view showing the leading edge of the card advanced to the storage unit in FIG.


8


.











BEST MODE FOR ACHIEVING THE INVENTION




A preferred embodiment of a card printer according to the present invention is described below with reference to the accompanying figures.





FIG. 1

is an oblique view showing the appearance of a card printer according to a preferred embodiment of the present invention.

FIG. 2

is an oblique view showing the appearance of the top case of the card printer shown in

FIG. 1

as seen from the inside.

FIG. 3

is an oblique view showing the appearance of the frame housed inside the card printer shown in FIG.


1


.

FIG. 4

is an oblique view showing the appearance of the bottom case of the card printer shown in

FIG. 1

as seen from the inside. FIG.


5


(


a


) is an oblique view showing the basic configuration of the printing unit, and (


b


) is an oblique view showing the printing unit mounted to the frame shown in FIG.


3


.





FIG. 6

is a side view showing the basic configuration of the same card printer.

FIG. 7

is an enlarged view showing essential parts in FIG.


6


.




As shown in

FIG. 1

to FIG.


4


and FIGS.


5


(


a


) and (


b


), a card printer


1


according to this embodiment of the invention has a top case


20


, frame


30


, bottom case


40


, and printing unit


50


. The top case


20


, frame


30


, and bottom case


40


are formed so that when combined they form an integrated structure. It should be noted that the top case


20


, frame


30


, and bottom case


40


are molded from a resin such as ABS.




As shown in

FIG. 1

or

FIG. 2

the top case


20


is a box-like shape of a specific size. A card insertion opening


23


for inserting and ejecting cards is formed at the front (bottom right in

FIG. 1

) of the top case


20


by disposing an opening where a pair of flat wall surfaces


21


,


22


join.




In this embodiment of the invention cards having a heat-sensitive layer laminated to a paper base of a specific size and coated with a plastic layer, including, for example, consecutive cards having a prepaid card part and a connected coupon. These cards have a property of being stiff, that is, they resist being bent with elastic force of a specific magnitude.




Guide


24


(fifth guide) and guide


25


(fourth guide) are formed on the back of the top case


20


integrally to the top case


20


. Substantially triangular ribs


24




a


are disposed in a row near the card insertion opening


23


, and guide


24


is formed by these ribs


24




a


. Squared teeth


25




a


are disposed in a row at a specific height at a place separated a specific distance from this auxiliary guide


24


. A comb-like guide


25


is formed by these teeth


25




a.






It should be noted that mounting claws


26


for mounting a certain terminal such as a CAT (not shown in the figure) equipped with the card printer are formed on the outside top of the top case


20


.




As shown in

FIG. 3

the frame


30


is a size able to cover the open part of the top case


20


and has a flat panel part


31


and a substantially V-shaped opening


32


formed contiguously/integrally to one end of the panel part


31


. A mounting part


32




a


for installing the printing unit


50


described below is formed to this substantially V-shaped opening


32


. In addition, the frame


30


can be fastened to the top case


20


using screws, for example.




A mounting surface


31




c


for securing a control board


73


(shown in

FIG. 6

) is formed on the back side of the panel part


31


as seen in

FIG. 3

, and a wall


31




a


that becomes the ceiling part of a storage chamber


100


for temporarily storing cards transported by the printing unit


50


is formed on the front side. The area of this wall


31




a


is defined as larger than the size of the card (the size of the prepaid card and the coupon).




A guide


61


(third guide) is formed at the interface between the panel part


31


and substantially V-shaped opening


32


. That is, a plurality of claws


31




b


with a protruding curved shape is formed in this part, and these form the guide


61


. The individual claws


31




b


are disposed so that when the frame


30


is mounted to the top case


20


they mesh with the teeth


25




a


of the comb-like guide


25


. As a result, when a card is transported, the leading edge of the card transported from the printing unit


50


is guided to the storage chamber


100


formed on the back side of the control board


73


by both guide


61


and guide


25


.




Along the edges of the substantially V-shaped opening


32


are disposed a guide


63


(first guide) for guiding a card inserted to the printing unit


50


mounted there, and a guide


62


(second guide) for guiding a card transported from the printing unit


50


to guide


61


. Guide


63


is disposed to the edge on the side opposite the edge to which guide


62


is disposed. As shown in

FIG. 7

, the transportation path formed inside the printing unit


50


when the printing unit


50


is installed to the mounting part


32




a


is continuous to the transportation path defined by guide


63


and guide


62


.




Moreover, as also shown in

FIG. 7

, mounting parts


63




b


,


62




b


for fastening paper sensors


71


,


72


are disposed respectively to guides


63


,


62


of the frame


30


. The paper sensors


71


,


72


fastened to the mounting parts


63




b


,


62




b


are configured to detect the presence of a card using a light reflection method, and output a specific signal. It should be noted that a paper sensor is disposed to both guides


62


,


63


in this embodiment but can be disposed to only either guide.




It should be noted that guides


61


,


62


,


63


are formed integrally to the frame


30


. That is, mounting parts


32




a


,


31




c


for installing the printing unit


50


and control board


73


, main guides


61


,


62


,


63


for guiding cards transported by the printing unit


50


, and mounting parts


63




b


,


62




b


for installing the paper sensors


71


,


72


, are formed integrally to the frame


30


. Furthermore, while not shown in the figures, a mounting part for an LED for presenting the printer status (such as an error indicator) can also be disposed to the frame


30


.




In addition, a cable guide for fastening signal cables for connecting control board


73


to functional components such as the printing unit


50


(motor


53


, thermal head


51


), paper sensors


71


,


72


, and LED can also be formed integrally to the frame


30


.




By thus constructing the frame


30


, the major members and components can be removed en masse by removing the frame


30


from the case after simply opening the top and bottom cases


20


,


40


. In other words, disassembly and assembly can be easily accomplished.




As shown in

FIG. 1

or

FIG. 4

, the bottom case


40


is formed as a box-shaped piece of a size able to cover the frame


30


installed to the top case


20


and the printing unit


50


mounted thereto. In addition, the bottom case


40


is configured so that it can be installed to and removed from the top case


20


by insertion fitting.




A plurality of rectilinear parallel ribs


64


is disposed to this bottom case


40


.




As shown in

FIG. 7

, the top of each rib


64


is at a position parallel to the wall


31




a


of frame


30


with a specific gap therebetween, and is disposed at a position adjacent to guide


62


of frame


30


. The ribs


64


form a storage chamber


100


able to temporarily store a card in the space to the wall


31




a


of frame


30


.




Next, as also shown in

FIG. 7

, when the top case


20


is mounted to the frame


30


, the bottom of each tooth


25




a


of the comb-like guide


25


formed on the top case


20


is disposed substantially parallel to the wall


31




a


(ceiling of storage chamber


100


) of frame


30


. The guide


25


is defined so as to be recessed a slight distance d above wall


31




a


. In addition, part of the guide


25


is opposite guide


62


formed to frame


30


.




As shown in FIGS.


5


(


a


), (


b


) or

FIG. 6

, the printing unit


50


has a thermal head


51


with a flat head unit


51




a


comprising a specific heat-emitting element, and a platen roller


52


that turns in contact therewith to transport a card, and is configured so that power from the motor


53


, which is a stepping motor, is transferred through a specific gear train


54


to this platen roller


52


.




In the following description of the present embodiment the card transportation direction from the card insertion opening


23


toward the storage chamber


100


is called the “downstream direction,” and the transportation direction opposite the downstream direction is the “upstream direction.” In addition, the directions of rotation in which the platen roller


52


turns to transport a card in these directions are the “forward direction” and “reverse direction,” respectively.




As shown in

FIG. 7

, when the frame


30


with this printing unit


50


mounted thereto is housed in the top case


20


, the thermal head


51


and thermal head


51


are positioned near the card insertion opening


23


on the inside of the top case


20


. Furthermore, the bottom part of the platen roller


52


is disposed at a position between guide


24


and guide


25


of top case


20


and projecting slightly therebelow.




The thermal head


51


is disposed so that the flat PS (below called the “printing surface”) containing the surface of this head unit


51




a


is parallel to the wall


31




a


of the frame


30


.




Furthermore, guide


62


is disposed at a position on the downstream direction side of the thermal head


51


. This guide


62


is disposed with a specific gap to guide


25


, and is disposed so as to project slightly from the printing surface of thermal head


51


toward the guide


25


. Furthermore, an inclined surface


62




a


sloped at a specific angle is formed to this guide


62


from a position near the thermal head


51


toward guide


25


.




In addition, guide


63


is disposed to the upstream direction side of the thermal head


51


. The surface of this guide


63


is sloped at substantially the same angle as wall


22


disposed near the card insertion opening


23


of top case


20


so as to guide a card inserted along the wall


22


between thermal head


51


and platen roller


52


.




Because guide


63


is thus inclined at substantially the same angle as the wall


22


, the card curves between guide


62


and guide


63


, and the card is thus transported wrapped to the platen roller


52


.




It should be noted that a driver IC


51




b


for driving the heat-emitting element is disposed to this thermal head


51


. This driver IC


51




b


is encased in resin and formed to a height that will not obstruct insertion of a card guided by guide


63


to the part where thermal head


51


and platen roller


52


contact.




A control unit


74


comprising, for example, a CPU and memory for storing a program, and a communication interface, for example, are mounted on the control board


73


fixed to mounting surface


31




c


of frame


30


. This control board


73


is electrically connected to the paper sensors


71


,


72


, and is also electrically connected to motor


53


and thermal head


51


. The control unit


74


of control board


73


is thus configured so that it can control the operation of motor


53


and driving thermal head


51


based on specific print data or signals sent from paper sensors


71


,


72


.




Furthermore, firmware recording a sequence for a printing process for driving the thermal head


51


while turning the motor


53


in the forward direction, and firmware recording a sequence for driving the motor


53


in the reverse direction without driving the thermal head


51


to eject a card from the card insertion opening


23


, are recorded to this control unit


74


.




The state changes whereby a card is transported in a card printer according to this embodiment of the invention are described below using

FIG. 8

to FIG.


12


.




As shown in

FIG. 8

, when a card


10


is held with the heat-sensitive side thereof facing down and the card


10


is inserted to the card insertion opening


23


of the printer


1


, this card


10


is guided by guide


63


and the leading edge


10




a


of the card


10


comes between the thermal head


51


and platen roller


52


. In this case the paper sensor


71


disposed to guide


63


sends a signal indicating detection of the card


10


to the control unit


74


of control board


73


, and based thereon the control unit


74


operates the motor


53


and turns the platen roller


52


in the forward direction.




As a result, the platen roller


52


pulls the card


10


while bending it between guide


63


and thermal head


51


to the head unit


51




a


of thermal head


51


, and transports it in the direction of guide


62


. When the paper sensor


72


disposed to guide


62


detects the leading edge


10




a


of card


10


, the control unit


74


turns the platen roller


52


in the reverse direction a pulse count equivalent to the distance L between the detection position of the paper sensor


72


and the heat-emitting element of the thermal head


51


to index the card


10


to the head unit


51




a


of the thermal head


51


.




The control unit


74


then turns the platen roller


52


in the forward direction while driving the thermal head


51


to print content, including a pass code or usage count, for example, to a desired position on the card


10


.




When the card


10


is then transported from between platen roller


52


and thermal head


51


it proceeds along the printing surface and the leading edge


10




a


of card


10


contacts paper guide


62


as shown in FIG.


9


.




As shown in

FIG. 10

, guide


62


guides the card


10


thus disposed so that the leading edge


10




a


is guided to guide


25


while the inclined guide surface


62




a


gradually deflects the card


10


.




Because guide


62


supports the middle of the card


10


with force resisting the elastic force of the card


10


after the leading edge


10




a


of card


10


reaches guide.


25


, the leading edge


10




a


of the card


10


thereafter advances along guide


25


while pressed against the guide


25


. The card


10


is also transported wrapped a specific angle to the platen roller


52


between guide


62


and guide


63


.




As shown in

FIG. 11

, when the leading edge


10




a


of card


10


advances in this manner to guide


61


, it is guided along the surface of claws


31




b


formed in a curve to wall


31




a


of storage chamber


100


slightly below guide


25


as shown in FIG.


12


.




When the leading edge


10




a


of card


10


then passes guide


61


and is guided to wall


31




a


of storage chamber


100


, the card


10


is deflected slightly in the shape of a curved surface by the support from guide


62


, and the force with which the leading edge


10




a


of card


10


pushes against wall


31




a


increases.




When the trailing end part of the card


10


reaches the thermal head


51


, thermal stress is produced by the difference in the linear expansion coefficients of the top layer part (paper part) and the bottom layer part (plastic layer part) of the card


10


as a result of the environmental temperature, and the trailing end part of the card


10


wants to deflect to the side separating from the thermal head


51


. However, because the card


10


is bent by the guide


62


and the leading edge


10




a


of card


10


is pressed against the wall


31




a


, it is difficult for the trailing end part of the card


10


to separate from the heat-emitting element of the thermal head


51


.




Because guide


62


projects from the printing surface and guides the leading edge


10




a


of the card


10


to the guide


25


side and wall


31




a


projects slightly (distance d in

FIG. 7

) below the guide


25


, the card can be deflected from the position where the leading edge


10




a


of the card


10


is passed the guide


61


so that the force pressing the leading edge


10




a


of card


10


against the wall


31




a


of the storage chamber


100


is increased.




The control unit


74


of control board


73


then stops driving the thermal head


51


after the specific printing is completed, and turns the platen roller


52


in the reverse direction to eject the card


10


. The control unit


74


then counts a specific pulse count from the point at which a signal indicating there is no card


10


is received from paper sensor


72


, and then stops motor


53


operation.




If the length of the card


10


in the transportation direction is relatively short in this continuous printing and paper transportation process, the card


10


will not contact the ribs


64


of the case


40


, but even if a paper jam occurs for some reason with such a short card, such a card


10


will be received by the ribs


64


.




By projecting guide


62


slightly toward guide


61


relative to the printing surface of the thermal head


51


so that the leading edge of the card is pressed against the wall


31




a


of the storage chamber


100


to transport the card


10


into the storage chamber using the stiffness of the paper stock of the card, the present embodiment as described above can prevent rubbing against the heat sensitive surface of the card. Furthermore, because warping that occurs easily at the trailing end of the card can be thus corrected and the card can be held in constant contact with the heat-emitting element of the thermal head


51


, printing can be prevented from blurring.




In addition, the card can be gradually deflected and the leading edge of the card can be smoothly pressed against guides


25


,


61


because an inclined surface


62




a


is formed on the guide


62


to guide the leading edge


10




a


of the card


10


to guides


25


,


61


.




Furthermore, because the card is transported between guide


62


and guide


63


so as to wrap to the platen roller


52


with the present embodiment, suitable print pressure can be achieved without being affected by rubber hardness when an elastomer is used for the platen roller


52


, for example, and pressure produced at the leading edge of the card can be stabilized because constant tension can be maintained at the part where the card contacts the platen roller


52


and the part on the opposite side.




Yet further, because the ribs


64


are disposed to the bottom case


40


and this bottom case can be attached to and removed from the top case without using screws, for example, the present invention makes it simple to handle paper jams. Furthermore, the card can be ejected with the printed side down and the printed side of the card is covered by the bottom case


40


because the bottom case


40


is disposed on the thermal head


51


side, and the confidentiality of a pass code, for example, can thus be improved.




In addition, while it is possible to print while inserting or ejecting the card, this embodiment of the invention prints only when inserting the card and does not print when ejecting the card, and it is therefore possible to avoid interference with the printing process as a result of the operator pulling on the card as it is being ejected.




It should be noted that present invention shall not be limited to the above embodiment and can be modified in various ways.




For example, a thermal head


51


is used for the print head in the present embodiment, but the present invention can use an inkjet type print head under specific conditions. In this case, however, guides


61


,


62


,


63


are disposed in the same way as described above but a flat platen is used in place of platen roller


52


and a pair of paper transportation rollers is used on both the upstream and downstream sides of this platen. The inkjet head is then disposed with a specific gap to the printing surface defined by defined by this flat platen. Furthermore, the paper transportation rollers disposed in the downstream direction (the guide


62


side) from the inkjet head must be configured to meet such conditions preventing ink on the card from transferring to other parts after printing, such as using pinch rollers that hold only both edge parts of the card.



Claims
  • 1. A card printer comprising:a printing unit having a print head for printing to a card, a roller for transporting the card, and a motor for driving the roller; a control board for controlling the printing unit; and a frame having an integrally formed opening-shaped mounting unit for installing the printing unit, and a flat mounting surface for installing the control board; a first guide disposed to an edge of the opening-shaped mounting unit for guiding the card between the print head and roller; a second guide disposed at a specific angle to the first guide on an edge on a side opposite the edge to which the first guide is disposed; and a third guide disposed proximally to the second guide for guiding a card transported by the roller to a back side of the flat mounting surface; wherein said first, second and third guides are integrally formed to the frame.
  • 2. A card printer as described in claim 1, further comprising a wall forming part of a storage chamber for temporarily housing a card transported by the roller, said wall disposed to the back side of the flat mounting surface.
  • 3. A card printer as described in claim 2, further comprising a top and bottom pair of cases for housing the frame, the storage chamber being formed between said wall and the bottom case.
  • 4. A card printer as described in claim 1, wherein the surface of the second guide projects to said wall side from a printing surface defined by the print head and roller.
  • 5. A card printer as described in claim 4, wherein the printing surface and the wall are substantially parallel.
  • 6. A card printer as described in claim 1, further comprising:a top and bottom pair of cases for housing the frame, and a fourth guide disposed to the top case, wherein the fourth guide is formed in a comb shape so that the fourth guide is positioned to mesh alternately in part with the third guide when the frame is housed in the case.
  • 7. A card printer as described in claim 6, wherein part of the fourth guide is positioned opposite the second guide when the frame is housed in the case.
  • 8. A card printer as described in claim 1, further comprising:a top and bottom pair of cases for housing the frame, an insertion opening for inserting a card, and a fifth guide positioned adjacent to the insertion opening, the insertion opening and the fifth guide being disposed to the top case, wherein the fifth guide is located opposite the first guide when the frame is housed in the case.
  • 9. A card printer as described in claim 1, further comprising a detector for detecting presence of a card; the detector being disposed to the first guide or second guide.
Priority Claims (1)
Number Date Country Kind
2001-8706 Jan 2001 JP
PCT Information
Filing Document Filing Date Country Kind
PCT/JP01/04060 WO 00
Publishing Document Publishing Date Country Kind
WO02/05708 7/25/2002 WO A
US Referenced Citations (4)
Number Name Date Kind
5949058 Kimura Sep 1999 A
6158907 Silverbrook et al. Dec 2000 A
6241332 Cummins et al. Jun 2001 B1
6473728 Tognazzini Oct 2002 B1
Foreign Referenced Citations (5)
Number Date Country
63-854 Jan 1988 JP
2-231151 Sep 1990 JP
9-141954 Jun 1997 JP
10-230655 Sep 1998 JP
11-5341 Jan 1999 JP