Tape dispenser having printing means for printing the tape being dispensed

Information

  • Patent Grant
  • 6810802
  • Patent Number
    6,810,802
  • Date Filed
    Friday, November 22, 2002
    22 years ago
  • Date Issued
    Tuesday, November 2, 2004
    20 years ago
  • Inventors
  • Examiners
    • Nguyen; Anthony H.
    Agents
    • Bacon & Thomas, PLLC
Abstract
A tape dispenser. The dispenser includes a printing device for printing the tape being dispensed, a main body holding a tape roll holder, a printing wheel, a tape cutter, and an ink supply unit. The printing wheel has a cylindrical base made of hard material, and protruded portions protruded from the periphery of the cylindrical base and forming a printing surface around the periphery of the cylindrical base and coaxial to the cylindrical base. The ink supplying unit has a housing detachably mounted on the main body for receiving ink therein. A porous ink soaking layer is mounted inside the housing and adapted to soak the ink, and a fabric ink applying layer is covered on the porous ink soaking layer and partially exposed to, the outside of the housing and in contact with the printing surface of the printing wheel.
Description




BACKGROUND OF THE INVENTION




1. Field of the Invention




The present invention relates to tape dispensers and, more specifically, to a tape dispenser having printing means for printing the tape being dispensed.




2. Description of the Related Art




U.S. Pat. Nos. 5,947,025 and 6,112,659 respectively disclose a tape dispenser capable of printing patterns and words on the tape dispensed thereby and an adhesive tape dispenser provided with means for printing adhesive tape being dispensed. When the adhesive tape applied to the carton or the like, it seals the carton and, simultaneously provides a marking or advertising effect. The sprinting wheels of the aforesaid two U.S. patents (the member referenced by 30 in U.S. Pat. No. 5,947,025 and the member referenced by 40 in U.S. Pat. No. 6,112,659) are, as shown in

FIG. 1

, commonly comprised of a hard wheel body A (generally molded from plastics) and a flexible printing plate B (generally made of rubber). The flexible printing plate B has patterns and words formed thereon and, is adhered to the periphery of the wheel body A. Alternatively a packing strip (not shown) may be used to fasten the ends of the flexible printing plate B to the periphery of the wheel body A.




These two printing wheel designs have numerous drawbacks as outlined hereinafter.




1. Because the flexible printing plate is adhered to the periphery of the wheel body or fastened thereto by a packing strip, it tends to be forced out of the wheel body.




2. The flexible printing plate may be not smoothly evenly covered on the periphery of the hard wheel body, resulting in poor printing quality.




3. Due to technique limitations, sufficient space must be left in the four sides of the top surface of the rectangular flexible printing plate around the patterns and words during formation of the patterns and words. When the flexible printing plate rolled up into a roll around the periphery of the wheel body, a big blank area is left around the abutted ends of the flexible printing plate. The installation of the packing strip also requires a big blank area around the abutted ends of the flexible printing plate. When continuously circulating the printing on the adhesive tape being dispensed, an interrupted blank area appears on the adhesive tape being dispensed at every unit distance (the packing strip may produce an ink trace on the adhesive tape being dispensed). On the other words, cannot print a continuous series of patterns and words without leaving a trace of the ends of the flexible printing plate.




4. Because the flexible printing plate is made of rubber, the printing surface of the patterns and words tends to be deformed when contacting the underside of the adhesive tape being dispensed, resulting in a vague printing quality. Due to the aforesaid drawbacks, the prior art designs are not suitable for printing fine patterns and fine words.




Further, the aforesaid two prior art designs commonly have an ink supplying device (commonly referenced by 50). According to these two U.S. patents, the ink supplying device comprises an ink storage cassette (referenced by 55 in U.S. Pat. No. 5,947,025, or 51 in U.S. Pat. No. 6,112,659), and a roller-like ink soaking member (referenced by 56 in U.S. Pat. No. 5,947,025, or 53 in U.S. Pat. No. 6,112,659) made of sponge and fastened rotatably with the ink storage cassette. The roller-like ink soaking member soaks up ink from the ink storage cassette, and keeps the periphery in close contact with the printing plate of the printing wheel. When the printing wheel rotated by the tape being dispensed, the roller-like ink soaking member is rotated to apply ink to the printing surface of the printing plate of the printing wheel, thereby causing the printing wheel to print patterns and words on the underside of the tape being dispensed.




The aforesaid ink supplying device is still not satisfactory in function. When the roller-like ink soaking member soaked up ink in the saturated status, excessive amount of ink may be applied to the periphery of the printing wheel, resulting in poor printing quality. Further, because the roller-like ink soaking member cannot keep ink wet for long, ink soaked up by the roller-like ink soaking member easily changes into vapor, resulting in unclear or thin printing on the tape being dispensed. In general, the use of the aforesaid ink supplying device makes printing quality control difficult.




SUMMARY OF THE INVENTION




The present invention has been accomplished to provide a tape dispenser having printing means for printing the tape being dispensed, which applies ink to the printing surface of the printing wheel evenly to achieve a high quality printing effect.




It is another object of the present invention to provide a tape dispenser having printing means for printing the tape being dispensed, which keeps ink from changing into vapor quickly.




It is still another object of the present invention to provide a tape dispenser having printing means for printing the tape being dispensed, which is durable in use and, achieves a high printing quality.




To achieve these objects of the present invention, the tape dispenser comprises a main body; a tape roll holder mounted on the main body to hold a tape roll such that the tape roll can be turned; a tape cutter mounted on the main body; a printing wheel fastened pivotally with the main body; an ink supply unit located on the main body, the ink supplying unit comprising an ink supply device adapted to apply ink to the periphery of the printing wheel. The printing wheel comprises a printing wheel body formed in integrity of hard material. The printing wheel body has a cylindrical base, and a plurality of protruded portions raised from the periphery of the cylindrical base and forming a printing surface around the periphery of the cylindrical base. The printing surface is coaxial to the cylindrical base. The ink supplying device comprises a housing detachably mounted on the main body for receiving ink therein, a porous ink soaking layer mounted inside the housing and adapted to soak the ink, and a fabric ink applying layer covered on the porous ink soaking layer and partially exposed to the outside of the housing. The fabric ink applying layer is disposed in contact with the periphery of the printing wheel at one side when the ink supplying device installed in the main body.




The printing wheel is made by using a programmable engraving machine to engrave a hard cylindrical base material into the desired finished product subject to a predetermined design. Because the printing surface is formed integral with the hard cylindrical base material, the printing surface does not drop from the printing wheel body. Because the protruded portions (printing surface) of the printing wheel body are a part of the circumference of the cylindrical base material before engraving, the finally finished printing surface has a good roundness that can be closely attached to the underside of the adhesive tape being dispensed to achieve a high quality printing. Because the printing wheel is made of hard material (for example, aluminum), the printing surface does not deform during printing, and fine patterns of the design of the printing surface can be clearly printed on the adhesive tape being dispensed. Further, because the printing surface is formed integral with in the periphery of printing wheel, the design of the printing surface has no interruption in it.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is an exploded view of a printing wheel for tape dispenser according to the prior art.





FIG. 2

is a perspective assembly view of a tape dispenser according to the present invention.





FIG. 3

is an exploded view of the tape dispenser according to the present invention.





FIG. 4

is a side plain view of the tape dispenser according to the present invention.





FIG. 5

is a bottom plain view of the front part of the tape dispenser according to the present invention.





FIG. 6

is a sectional view taken along line


6





6


of FIG.


2


.





FIG. 7

is similar to

FIG. 6

but showing the top cover of the ink supplying device closed.





FIG. 8

is a sectional view taken along line


8





8


of FIG.


3


.











DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT




Referring to FIGS.


2


˜


4


, a tape dispenser having printing means for printing the tape being dispensed in accordance with the present invention is a handheld tape dispenser comprised of a main body


10


, tape roll holder


20


, a front casing


30


, a tape-transfer cylinder


40


, a tape cutter


50


, an applicator plate


60


, a press member


70


, a printing wheel


80


, and an ink supplying unit


90


.




The main body


10


comprises a base panel


11


and a handle


12


provided at the bottom side of the base panel


11


. The base panel


11


comprises a first axle (namely, the upper axle)


13


and a second axle (namely, the lower axle)


14


perpendicularly extended from the middle area of the inner side thereof in transverse direction at different elevations, and a protrusion


111


provided below the second axle


14


. The axles


13


and


14


each have a screw hole


131


or


141


in the respective distal (free) end. The handle


12


comprises a mounting block


121


fixedly fastened to the inner side of the base panel


11


below the protrusion


111


, and a hand grip


122


downwardly extended from the bottom side of the mounting block


121


. The tape roll holder


20


is fastened rotatably with the rear end of the inner side of the base panel


11


of the main body


10


, and adapted to hold a tape roll (not shown). The front casing


30


is fixedly fastened to the front end of the inner side of the base panel


11


of the main body


10


remote from the tape roll holder


20


. The tape-transfer cylinder


40


is fastened rotatably with the inner side of the base panel


11


of the main body


10


in transverse direction, and suspended in the casing


30


. The tape cutter


50


is mounted in the top side of the casing


30


, and adapted to cut off the adhesive tape being dispensed. The applicator plate


60


is provided at the top side of the casing


30


, and adapted to press the adhesive tape being dispensed on the package.




Referring to FIG.


5


and

FIG. 4

again, the press member


70


comprises a rectangular plate


701


approximately equal to the length of the tape-transfer cylinder


40


. The rectangular plate


701


has two front press portions


702


bilaterally protruded from the front side thereof. The rear side of the rectangular plate


701


is fastened pivotally with the front side of the mounting block


121


of the handle


12


. A torsional spring


75


is provided between the rectangular plate


701


and the mounting block


121


of the handle


12


to impart an upward biasing force to the rectangular plate


701


, keeping the two front press portions


702


of the rectangular plate


701


slightly pressed on the periphery of the tape-transfer cylinder


40


at the bottom side (the objective will be described later).




Referring to FIG.


6


and

FIGS. 3 and 4

again, the printing wheel


80


is comprised of a printing wheel body


81


, a first end member


82


, and a second end member


83


. The printing wheel body


81


is a hollow cylindrical member made of aluminum (or any of a variety of hard materials including metal materials, acrylics, and etc.), having a cylindrical base


811


, a through hole


812


axially extended through the two distal ends of the base


811


, two inside annular coupling grooves


813


respectively disposed in the two ends of the base


811


around the through hole


812


, protruded portions (patterns and words)


814


raised from the periphery D


1


of the base


811


and forming a printing surface


815


around the periphery of the base


811


. The protruded portions


814


have the same thickness so that the surface of the printing surface


815


is on the same (imaginary) circumference D


2


, which is coaxial to the base


811


. The surface of the printing surface


825


is preferably a coarse surface to facilitate retaining of ink, so that a clear printing can be achieved. The first end member


82


comprises a disk


821


, the disk


821


having a diameter greater than maximum outer diameter of the printing wheel body


81


(the diameter of the aforesaid imaginary circumference D


2


), a shaft


822


perpendicularly extended from the center of one side, namely, the inner side of the disk


821


, an axial center hole


823


axially extended through the center of the shaft


822


and the disk


821


, and an annular coupling flange


824


protruded from the inner side of the disk


821


and equally spaced around the shaft


822


and press-fitted into one inside annular coupling groove


813


of the base


811


of the printing wheel body


81


. The second end member


83


comprises a disk


831


, the disk


831


having an outer diameter equal to the disk


821


of the first end member


820


, an axial center hole


833


axially extended through the center of the disk


831


, a barrel


832


protruded from the inner side of the disk


831


around the axial center hole


833


and sleeved onto the free end of the shaft


822


of the first end member


82


, and an annular coupling flange


834


protruded from the inner side of the disk


831


and equally spaced around the barrel


832


and press-fitted into one inside annular coupling groove


813


of the base


811


of the printing wheel body


81


opposite to the first end member


82


.




The assembly process of the printing wheel


80


is outlined hereinafter with reference to

FIGS. 2 and 6

again, insert the shaft


822


of the first end member


82


into the through hole


812


of the base


811


of the printing wheel body


81


to force the annular coupling flange


824


into one inside annular coupling groove


813


of the base


811


of the printing wheel body


81


, keeping the disk


821


covered on one end of the printing wheel body


81


, and then press-fit the annular coupling flange


834


of the second end member


83


into the other inside annular coupling groove


813


of the base


811


of the printing wheel body


81


, keeping the barrel


832


sleeved onto the free end of the shaft


822


of the first end member


82


. When assembled, the axial center hole


823


of the first end member


82


and the axial center hole


833


of the second end member


83


are axially aligned in the central axis of the printing wheel body


81


in communication with each other. The printing wheel


80


is then fastened pivotally with the base panel


11


of the main body


10


by: coupling the axial center hole


823


of the first end member


82


and the axial center hole


833


of the second end member


83


to the first axle


13


of the base panel


11


, and then fastening a screw bolt


84


to the screw hole


131


of the first axle


13


to secure the printing wheel


80


to the main body


10


.




The printing wheel body


81


is made by using a programmable engraving machine to engrave the periphery of a cylindrical aluminum base material into the desired finished product subject to the design of a predetermined plain mother pattern drawing. It is to be understood that the circumference of the cylindrical aluminum base material is the aforesaid circumference D


2


of the printing surface


815


. According to the preferred embodiment of the present invention, the two end members


82


and


83


are separately made, and then fastened to each other and secured to the printing wheel body


81


at two sides. Alternatively, two end disks can be directly formed on the two ends of the engraved cylindrical base material. After formation of the printing surface


815


, the printing wheel body


81


is coarsened by means of the application of a sand blasting equipment, so that the printing surface


815


can retain ink and transfer retained ink to the adhesive tape being dispensed.




Referring to

FIGS. 3 and 4

again, the ink supplying unit


90


is comprised of a rack


91


, an ink supplying device


92


, and a torsional spring


94


. The rack


91


comprises a cup-like frame base


911


, a barrel


914


fixedly provided at one lateral side of the cup-like frame base


911


, and a flat receiving chamber


916


located on the other lateral side of the cup-like frame base


911


opposite to the barrel


914


. The cup-like frame base


911


has an opening


912


in the periphery at the top side, and an elongated mounting slot


913


in the periphery at the bottom side. The barrel


914


is sleeved onto the second axle


14


of the main body


10


, for enabling the rack


91


to be turned about the second axle


14


. Further, the barrel


914


has a locating hole


915


. A screw bolt


93


is threaded into the screw hole


141


of the second axle


14


to secure the rack


91


to the second axle


14


. When installed, the cup-like frame base


911


is disposed below the printing wheel


80


, and the opening


912


of the cup-like frame base


911


is kept facing the printing surface


815


of the printing wheel body


81


of the printing wheel


80


. The torsional spring


94


is mounted within the barrel


914


around the second axle


14


, having one end fastened to the locating hole


915


of the barrel


914


and the other end extended to the outside of the barrel


914


and fastened to the protrusion


111


of the base panel


11


of the main body


10


. The torsional spring


94


imparts a biasing force to the rack


91


to force the cup-like frame base


911


of the rack


91


toward the printing wheel


80


.




Referring to

FIGS. 7 and 8

and

FIGS. 2

,


3


, and


6


again, the ink supplying device


92


comprises a housing


921


, a porous ink soaking layer


925


, a fabric ink applying layer


926


, and a top cover


927


. The housing


921


is shaped like a rectangular box having a top opening


923


, a round arch-like inner shell


924


suspended on the inside, and a bottom mounting flange


922


. The porous ink soaking layer


925


is piece of absorptive non-woven fabrics (for example, felt) mounted within the housing


921


and closely covered on the round arch-like inner shell


924


, keeping the two distal ends thereof fixed to the bottom side of the housing


921


.The fabric ink applying layer


926


is a piece of velvet closely attached to the outer surface of the ink soaking layer


925


, keeping the two distal ends thereof fixed to the bottom side of the housing


921


. The center area (the top area) of the fabric ink applying layer


926


protrudes through the top opening


923


over the top side of the housing


921


. The ink supplying device


92


is mounted inside the cup-like frame base


911


of the rack


91


by plugging the bottom mounting flange


922


of the housing


921


into the elongated mounting slot


913


of the cup-like frame base


911


of the rack


91


. Because the torsional spring


94


imparts a biasing force to the cup-like frame base


911


toward the printing wheel body


81


of the printing wheel


80


, the fabric ink applying layer


926


is maintained in contact with the printing surface


815


of the printing wheel body


81


of the printing wheel


80


(see FIG.


6


). When not in use, the top cover


927


is closed on the top opening


923


of the housing


921


(see FIG.


7


). At this time, the two ends of the top side of the top cover


927


is stopped at the bottom sides of the disks


821


and


831


of the end members


82


and


83


of the printing wheel


80


without touching the printing surface


815


of the printing wheel body


81


. When removed from the housing


921


, the top cover


927


can be received in the receiving chamber


916


of the rack


91


(see FIGS.


2


and


3


).




The use and functioning of the tape dispenser are described hereinafter. When not in use, the top cover


927


of the ink supplying device


92


is closed on the top opening


923


of the housing


921


to prevent quick drying of ink. When in use, the top cover


927


is removed from the housing


921


, and then received in the receiving chamber


916


of the rack


91


. Before use, check the ink containing status of the ink supplying device


92


, If it is necessary to refill the ink supplying device


92


with ink, pull the cup-like frame base


911


of the rack


91


downwards against the spring power of the torsional spring


94


(see the imaginary line shown in FIG.


4


), and then remove the ink supplying device


92


from the rack


91


, and then drip a proper amount of ink onto the fabric ink applying layer


926


in the top opening


923


of the housing


921


of the ink supplying device


92


, for enabling supplied ink to be absorbed by the ink soaking layer


925


, and then load the ink supplying device


92


in the cup-like frame base


911


of the rack


91


again. When released the hand from the rack


91


after loading of the ink supplying device


92


in the cup-like frame base


911


, the rack


91


is returned to its former position, keeping thee fabric ink applying layer


926


in close contact with the printing surface


815


of the printing wheel body


81


of the printing wheel


80


(see FIG.


6


). Further, the lead end of the adhesive tape roll (not shown) carried on the tape holder


20


is pulled out, and extended over the top side of the printing wheel


80


and the bottom side of the tape-transfer cylinder


40


to the tape cutter


50


. Please refer to FIG.


5


. The two front press portions


702


of the rectangular plate


701


of the press member


70


are slightly pressed on the adhesive tape T against the periphery of the tape-transfer cylinder


40


. When applying the adhesive tape T to seal a carton or the like, the printing wheel


80


is rotated by the forwardly dispensed adhesive tape T over the fabric ink applying layer


926


in the top opening


923


of the housing


921


of the ink supplying device


92


, and therefore the printing surface


815


is continuously covered with ink and printing the underside of the adhesive tape T being dispensed.




As indicated above, the tape dispenser having printing means for printing the tape being dispensed has the features and advantages as follows:




1. The ink supplying device


92


uses the absorptive non-woven fabrics of ink soaking layer


925


to retain ink in the saturated status. The porous structure of the absorptive non-woven fabrics (felt) of ink soaking layer


925


enables the ink soaking layer


925


to be filled with ink completely and, keeps ink from changing into vapor. Further, the fabric ink applying layer


926


slows down ink drying speed, and can be gently maintained in close contact with the printing surface


815


of the printing wheel body


81


of the printing wheel


80


, enabling ink to be evenly applied to the printing surface


815


of the printing wheel body


81


of the printing wheel


80


to achieve a high quality printing effect.




2. Because the protruded portions


814


(printing surface


815


) of the printing wheel body


81


are a part of the circumference of the cylindrical aluminum base material before engraving, the finally finished printing surface


815


has a good roundness that can be closely attached to the underside of the adhesive tape being dispensed to achieve a high quality printing.




3. Because the printing wheel body


81


is made of hard material (for example, aluminum), the printing surface


815


does not deform during printing, and fine patterns of the design of the printing surface


815


can be clearly printed on the adhesive tape being dispensed.




4. Because the printing surface


815


is formed integral with the periphery of the printing wheel body


81


, the design of the printing surface


815


has no interruption in it.




5. Because the printing surface


815


is formed integral with the base


811


, the printing surface


815


does not drop from the base


811


, and the printing wheel body


81


is durable in use.




While only one embodiment of the present invention has been shown and described, it will be understood that various modifications and changes could be made thereunto without departing from the spirit and scope of the invention disclosed. For example, the tape dispenser can be made in the form of a tape-top type instead of the aforesaid handheld type.



Claims
  • 1. A tape dispenser comprising:a main body; a tape roll holder mounted on said main body for holding a tape roll thereon; a tape cutter mounted on said main body; a printing wheel fastened rotatably with said main body; an ink supply unit located on said main body for supplying ink to said printing wheel; wherein said printing wheel comprises a printing wheel body formed in integrity of hard material, said printing wheel body having a cylindrical base and a plurality of protruded portions raised from the periphery of said cylindrical base and directly forming a printing surface around the periphery of said cylindrical base, said printing surface being coaxial to said cylindrical base; wherein said ink supplying unit comprises a housing detachably mounted on said main body for receiving ink therein, a porous ink soaking layer mounted inside said housing and adapted to soak the ink, and a fabric ink applying layer covered on said porous ink soaking layer and being disposed in contact with the periphery of said printing wheel at one side thereof when said ink supplying unit is installed in said main body; and wherein said housing of said ink supplying unit is a box-like hollow member having a top opening in a top side thereof, and a round arch-like inner shell disposed on the inside and adapted to support said porous ink soaking layer and said fabric ink applying layer inside said housing and to keep a part of said fabric ink applying layer exposed to the outside of said housing through said opening; said ink supplying unit further comprises a top cover adapted to close the top opening of said housing.
  • 2. The tape dispenser as claimed in claim 1, wherein said printing wheel further comprises a first disk and a second disk coaxially located on two distal ends of said cylindrical base.
  • 3. The tape dispenser as claimed in claim 2, wherein said cylindrical base has an axially extended center through hole; said first disk has a shaft perpendicularly extended from the center of one side thereof and inserted into the axially extended center through hole of said cylindrical base; said second disk has a barrel perpendicularly extended from the center of one side thereof and inserted into the axially extended center through hole of said cylindrical base and press-fitted onto the end of said shaft of said first disk remote from said first disk.
  • 4. The tape dispenser as claimed in claim 3, wherein said main body comprises an axle, said axle having a screw hole in an outer end thereof for the mounting of a screw bolt to secure said printing wheel to said main body for enabling said printing wheel to be rotated on the axle of said main body; said printing wheel has an axial hole axially extended through the shaft of said first disk and the barrel of said second disk and coupled to the axle of said main body for enabling said printing wheel to be rotated on the axle of said main body.
  • 5. The tape dispenser as claimed in claim 1, wherein said printing surface of said printing wheel has a coarsened surface.
  • 6. The ink dispenser as claimed in claim 1, wherein said main body comprises a base panel, a handle located on a bottom side of said base panel, a front casing located on a front side of said base panel, a tape-transfer cylinder fastened rotatably with said base panel inside said front casing, a press member provided below said tape-transfer cylinder, said press member having a rectangular plate, said rectangular plate having a rear side fastened pivotally with a top front side of said handle and two front press portions bilaterally protruded from a front side thereof, and a torsional spring provided between the rear side of said rectangular plate and said handle to impart a torsional force to said rectangular plate such that the two front press portions of said rectangular plate are pressed on the periphery of said tape-transfer cylinder at a bottom side thereof; said tape cutter is provided at a front side of said front casing of said main body; said tape roll holder and said printing wheel and said ink supplying unit are mounted on an inner side of said base panel of said main body.
  • 7. The ape dispenser as claimed in claim 1, wherein said ink supplying unit further comprises a rack, said rack having a cup-like frame base fastened pivotally with said main body, said cup-like frame base having an opening, and a torsional spring provided between said cup-like frame base and said main body to impart a torsional force to said cup-like frame base such that the opening of said cup-like frame base is maintained facing the periphery of said printing wheel; said housing of said ink supplying device is detachably mounted in said cup-like frame base for enabling said fabric ink applying layer to be partially extended out of the opening of said cup-like frame base into contact with the periphery of said printing wheel.
  • 8. The tape dispenser as claimed in claim 1, wherein said cup-like frame base has a receiving chamber provided at one side of the periphery thereof and adapted to receive said top cover of said ink supplying unit.
  • 9. The tape dispenser as claimed in claim 1, wherein said porous ink soaking layer is made of non-woven fabrics.
US Referenced Citations (11)
Number Name Date Kind
3678848 Roser et al. Jul 1972 A
3988987 Ikura et al. Nov 1976 A
5197386 Lin Mar 1993 A
5303648 Shih Apr 1994 A
5577444 Toyama Nov 1996 A
5732627 Imamaki Mar 1998 A
5743185 Hippely et al. Apr 1998 A
5784959 Larios Jul 1998 A
5947025 Huang Sep 1999 A
6170395 Lee Jan 2001 B1
20020062752 Clarke May 2002 A1