Patent Grant
7264239
This application is based on Japanese Patent Application No. 2003-84795 filed in Mar. 26, 2003, the content of which is incorporated hereinto by reference.
1. Field of the Invention
The present invention relates in general to a feeding device for feeding a paper sheet or other recording medium on which desired patterns of images or characters are printed by an inkjet print head.
2. Discussion of Related Art
As a feeding device for feeding a paper sheet in an inkjet printer, there is known a device including (a) a drive roller which is disposed on a downstream side of a recording portion of an inkjet print head as viewed in a feed direction of the paper sheet, and (b) a driven roller which is opposed to the drive, roller, so that the drive and driven rollers operate with each other to grip the paper sheet and feed the paper sheet in the feed direction. The driven roller is provided by a gear-like or toothed roller which has a plurality of radially-extending projections formed on a circumference of the roller. The paper sheet can be fed in a predetermined feed direction while being gripped by and between the drive roller and the driven roller which is forced toward the drive roller, after an ink has been ejected onto the medium so as to form an image on the medium. In this instance, even if the ink has not yet being dried, the ink does not adhere to the circumference of the driven roller, owing to the radially extending projections of the driven roller.
Such a known feeding device further includes a drive mechanism which is disposed on an upstream side of the recording portion. The drive mechanism serves to feed the paper sheet from a media supply portion to a printing-start position. When the paper sheet reaches the printing-start position, a printing operation is initiated by successive reciprocating motions of the recording portion in a primary scanning direction (perpendicular to the above-described feed direction). The paper sheet having reached the printing-start position is intermittently fed in the feed direction (corresponding to a secondary scanning direction) by a predetermined distance per each feed motion That is, after each of the successive reciprocating motions of the recording portion, the paper sheet is fed toward the drive roller disposed on the downstream side of the recording portion, while a desired pattern of image is being printed on the paper sheet. When a leading end of the paper sheet reaches the drive roller, the paper sheet enters between the drive and driven rollers. The printing operation is continued while the paper sheet is gripped by and between the rollers. After a trailing end of the paper sheet has passed through the drive mechanism disposed on the upstream side of the recording portion, the paper sheet is fed to a media exit portion, by only the drive and driven rollers cooperating to grip the paper sheet.
Generally, the drive roller is made of a rubber or metallic material. In some cases, the drive roller is covered at its surface with a coating layer which is made of a material having a high degree of coefficient of friction. On the other hand, the driven roller is made of a resin or metallic material. Since the driven roller is forced toward the drive roller, the rollers are in contact with each other during absence the paper sheet between the rollers, thereby problematically causing scratch of the drive roller or its coating layer and wear of the driven roller.
For solving such a conventional problem, there is proposed an arrangement, as disclosed in JP-A-H09-86749 (publication of unexamined Japanese Patent Application), which avoids the contact of the drive and driven rollers with each other.
In the above-described feeding device or arrangement, after the trailing end of the paper sheet is disengaged from the drive mechanism disposed on the upstream side of the recording portion, the paper sheet is fed to the exit portion, by the grip engagement of the paper sheet and the rollers. For reliably and accurately feeding the paper sheet, the driven roller has to be forced by a predetermined amount of pressing force, onto the paper sheet against the drive roller.
In the arrangement disclosed in JP-A-H09-86749, during absence of the paper sheet P between the rollers 40, 41, the radially outer end 45 of the driven roller 41 is positioned within the annular groove 43 of the drive roller 40, without the radially outer end 45 being in contact with a bottom surface of the groove 43. In this instance, since the rollers 40, 41 are not in contact with the each other, the flexible shaft 42 holding the driven roller 41 does not receive any load, or is slightly flexed downwardly due to weight of the driven roller 41. During presence of the paper sheet between the rollers 40, 41, the flexible shaft 42 is flexed upwardly as a result of the upward displacement of the driven roller 41. In this instance, a restoring force or spring load generated by the flexed flexible shaft 42 acts on the driven roller 41, whereby driven roller 41 is forced onto the paper sheet P.
Therefore, in the arrangement of JP-A-H09-86749, for reliably and accurately feeding the paper sheet P, an amount of the intersection or overlap of the radially outer end portions of the respective rollers 40, 41 has to be sufficiently large, so that the flexible shaft 42 is upwardly flexed by an amount required for obtaining the predetermined amount of pressing force during presence of the paper sheet P between the rollers 40, 41. It is noted that the intersection or overlap amount can be represented by a distance L1 (as indicated in
However, in this arrangement, upon entrance of the paper sheet P between the rollers 40, 41, the leading end of the paper sheet P has to force the driven roller 41 to be raised against the elastic force of the flexible shaft 42 by at least the distance L1. This means that an increase in the above-described overlap amount leads to an increase in force resisting the paper sheet P upon its entrance between the rollers 40, 41. The increase in the resistance force is likely to cause deflection of the paper sheet P and undesirable variation in the distance by which the paper sheet P is fed per each of the successive feed motions, thereby resulting in positional error of the printing spot and other deterioration in the printing quality. Particularly, where the printing operation is carried out by an inkjet printer, namely, where the operation is made with a high value of image resolution, the printing quality could be considerably affected by the variation in the feed distance even if an amount of the variation is small
The present invention was made in view of the background prior art discussed above. It is therefore an object of the present invention to provide a feeding device in which the recording medium can be introduced between the drive and driven rollers without a large force resistant to the recording medium, and can be gripped by and between the drive and driven rollers with a sufficiently large force, so that a printing operation can be achieved without deterioration in the printing quality. This object may be achieved according to any one of first through thirteenth aspects of the invention which are described below.
The first aspect of the invention provides a feeding device for feeding a recording medium in a feed direction, comprising: (a) a drive roller having an annular recess formed in an outer circumferential surface thereof; and (b) a driven roller rotatably held and positioned relative to said drive roller such that a radially outer end portion of said driven roller is positioned within said annular recess of said drive roller so that said radially outer end portion of said driven roller overlaps with a radially outer end portion of said drive roller. The driven roller is displaceable at least in a direction away from said drive roller, so that the recording medium is fed to pass between said drive roller and said driven roller, with the recording medium being gripped by said radially outer end portion of said driven roller and said radially outer end portion of said drive roller. The feeding device further comprising: (c) an overlap-amount limiter including a contact portion which is positioned within said annular recess, more specifically described, within a portion of the annular recess in which the radially outer end portions of the rollers overlap with each other. During absence of the recording medium between said driven roller and said drive roller, the contact portion of the overlap-amount limiter is held in contact at a surface thereof with said radially outer end portion of said driven roller, for thereby limiting an overlap amount by which said radially outer end portion of said driven roller overlaps with said radially outer end portion of said drive roller.
In the present feeding device, upon entrance of the recording medium between the drive and driven rollers, the recording medium displaces the driven roller in the direction away from the drive roller, so as to mount on the outer circumferential surface of the drive roller. A distance between axes of the respective rollers and the above-described overlap amount are predetermined based on an appropriate amount of pressing force that is to act on the recording medium gripped by and between the rollers. The driven roller is positioned relative to the drive roller such that the axes of the rollers are distant from each other by the predetermined distance and such that the radially outer end portion of the driven roller is positioned within the annular recess with the predetermined overlap amount. With provision of the overlap-amount limiter which is in contact with the radially outer end portion of the driven roller and limits the overlap amount, the driven roller is displaced by the overlap-amount limiter in the direction away from the drive roller even during absence of the recording medium between the rollers, thereby making it possible to reduce an amount by which the driven roller is to be displaced or raised by the recording medium. Therefore, this arrangement is effective to reduce the resistance which acts on the recording medium upon entrance of the medium between the rollers, thereby avoiding undesirable variation in the feed distance per each feed motion and accordingly assuring a high printing quality.
Owing to the provision of the overlap-amount limiter, the amount by which the driven roller is to be displaced by the recording medium is reduced. It should be noted that this reduction does not affect the pressing force which acts on the recording medium gripped by the rollers. That is, the overlap-amount limiter reduce the resistance which acts on the recording medium upon entrance of the medium between the rollers, but does not reduce the pressing force acts on the medium gripped by the rollers so that the medium can be reliably and accurately fed.
According to the second aspect of the invention, in the feeding device defined in the first aspect of the invention, said contact portion of said overlap-amount limiter is formed of a material which is harder than a material forming said driven roller, thereby making it possible to increase wear resistance of the contact portion of the overlap-amount limiter.
According to the third aspect of the invention, in the feeding device defined in the first or second aspect of the invention, the above-described surface of said contact portion of said overlap-amount limiter is positioned between said outer circumferential surface of said drive roller and a bottom surface of said annular recess of drive roller. In other words, the surface of the contact portion of the overlap-amount limiter is located between an axis of the drive roller and a portion of the outer circumferential surface of the drive roller which portion is in contact with the recording medium during presence of the recording medium between the drive and driven rollers.
According to the fourth aspect of the invention, in the feeding device defined in any one of the first through third aspects of the invention, said driven roller is formed of a resin. This arrangement is effective to reduce weight of the driven roller, and also to prevent the drive roller from being damaged even if the driven roller is brought into contact with the drive roller.
According to the fifth aspect of the invention, in the feeding device defined in any one of the first through fourth aspects of the invention, said overlap-amount limiter includes an annular member which is positioned within said annular recess. In this arrangement, the contact portion, which is to be held in contact at its surface with the radially outer end portion of the driven roller, can be easily positioned within the annular recess of the drive roller, by simply mounting or fitting the annular member as the overlap-amount limiter onto the drive roller. Further, since the annular member can be entirely accommodated within the annular recess of the drive roller, any additional space is not required for the provision of the annular member.
The sixth aspect of the invention provides an image recording apparatus comprising: the feeding device defined in any one of the first through fifth aspects of the invention; a recording portion which records an image on a recording medium and which is disposed on an upstream side of said feeding device as viewed in said feed direction; a platen which is opposed to said recording portion and supports the recording medium; and a media exit portion through which the recording medium exits from said apparatus after the image is recorded on the recording medium by said recording portion. In the present image recording apparatus, the recording portion is activated to record the image on the recording medium supported by the platen, and the recording medium is then fed to the media exit portion by the feeding device. As discussed above, since the feeding device has the arrangement effective to reduce the resistance acting on the recording medium upon entrance of the medium between the rollers, it is possible to feed the medium reliably and accurately, thereby assuring a high printing quality.
According to the seventh aspect of the invention, in the image recording apparatus defined in the sixth aspect of the invention, said overlap-amount limiter includes a tongue member extending in said feed direction and having a distal end portion as said contact portion positioned within said annular recess in which the radially outer end portions of the rollers overlap with each other. In this arrangement, the tongue member as the overlap-amount limiter is provided by a member independent from the drive roller so that the tongue member is not rotated together with the drive roller. Therefore, even if the tongue member is adapted to be constantly held in contact with the driven roller during absence of the recording medium between the driven and drive rollers, the tongue member and the driven roller are prevented from being easily scratched or worn, thereby improving durability of the apparatus. Further, since the tongue member as the overlap-amount limiter extends from the upstream side of the rollers to the annular recess of the drive roller, the tongue member is capable of serving to guide the recording medium to the radially outer end portion of the driven roller, thereby making it possible to rapidly and accurately introduce the recording medium between the drive and driven rollers.
According to the eighth aspect of the invention, in the image recording apparatus defined in the seventh aspect of the invention, said tongue member extends from said platen. In this arrangement, the recording medium, which has been fed while being held by the platen, can be guided rapidly by the tongue member from the platen to the radially outer end portion of the driven roller.
According to the ninth aspect of the invention, in the image recording apparatus defined in the eighth aspect of the invention, said tongue member is formed integrally with said platen, in other words, the tongue member and at least a part of the platen is provided by a single piece. This arrangement eliminates an operation to attach the tongue member to the platen in a process of manufacturing the image recording apparatus, thereby making it possible to simplify the manufacturing process.
According to the tenth aspect of the invention, in the image recording apparatus defined in the sixth aspect of the invention, said overlap-amount limiter includes a tongue member which extends in a direction opposite to said feed direction and which has a distal end portion as said contact portion which is positioned within said annular recess in which the radially outer end portions of the rollers overlap with each other. In this arrangement, the tongue member as the overlap-amount limiter is provided by a member independent from the drive roller so that the tongue member is not rotated together with the drive roller. Therefore, even if the tongue member is adapted to be constantly held in contact with the driven roller during absence of the recording medium between the driven and drive rollers, the tongue member and the driven roller are prevented from being easily scratched or worn, thereby improving durability of the apparatus.
According to the eleventh aspect of the invention, in the image recording apparatus defined in the tenth aspect of the invention, said tongue member extends from a member which constitutes at least a part of said media exit portion. In this arrangement, the member constituting at least the part of the media exit portion can serve also as a fixing device for fixing the tongue member in a predetermined position, thereby making it possible to save a space required for the installation of the tongue member.
According to the twelfth aspect of the invention, in the image recording apparatus defined in the eleventh aspect of the invention, said tongue member is formed integrally with said member which constitutes at least the part of said media exit portion. This arrangement eliminates an operation to attach the tongue member to the member constituting at least the part of the media exit portion, thereby making it possible to simplify a process of manufacturing the image recording apparatus.
According to the thirteenth aspect of the invention, in the image recording apparatus defined in the eleventh or twelfth aspect of the invention, said member which constitutes at least the part of said media exit portion is provided by a media exit tray which supports the recording medium after the image is recorded on the recording medium by said recording portion. In this arrangement, the media exit tray can serve also as a fixing device for fixing the tongue member in a predetermined position, thereby making it possible to save a space required for the installation of the tongue member.
The above and other objects features, advantages and technical and industrial significance of the present invention will be better understood by reading the following detailed description of presently preferred embodiment of the invention, when considered in connection with the accompanying drawings, in which:
The multifunction apparatus 1 has, on an upper face of its main body 2, an operating panel 3 equipped with an indicator display and various keys such as ten keys and function keys which are manually operable by an operator of the apparatus 1, to input various command signals for various operations (e.g., facsimileing, scanning and copying operations) to be performed by the apparatus 1. The apparatus 1 further has a media supply tray 22 and a media exit tray 31 located on back and front sides of the main body 2, respectively. In an operation with the apparatus 1, a recording medium in the form of a paper sheet P is supplied through the media supply tray 22 so that the paper sheet P is slid on a slant surface of the media supply tray 22, into the main body 2. On a surface of the paper sheet P supplied into the main body 2, a desired pattern of image is printed by a recording unit 21 of an inkjet head, which is built in the main body 2 as shown in
As shown in
The media supply tray 22 is stacked with the recording media in the form of the paper sheets P, which are separated one by one in a known manner with a separating device constituted by, for example, a friction pad or a friction plate. The feeding device 10 of the apparatus 1 is constructed such that each of the paper sheets P is fed in the forward direction (i.e., in the rightward direction as seen in
The feeding device 10 has first drive and driven rollers 28, 29 which are opposed to each other and located on the upstream side of the recording portions 25a as viewed in a feed direction of each paper sheet P. By an arm 61 which is held to be inclined such that its rear portion (left portion as seen in
A platen 30 is provided to be located on the downstream side of the first drive and driven rollers 28, 29, so as to be opposed to the recoding head 25, as shown in
The second rollers 40, 41 consist of a second drive roller 40 and a plurality of second driven rollers 41 which are opposed to the second drive roller 40. The paper sheet P is fed to pass between the second drive and driven rollers 40, 41, and is then received by the media exit tray 31. The drive roller 40, driven roller (wheels) 41 and members supporting these rollers 40, 41 cooperate to constitute a media outlet.
The drive roller 40 has, in its outer circumferential surface, a recess in the form of a plurality of annular grooves 43 which are formed to be axially spaced apart from each other, as shown in
Each of the second driven rollers 41 includes a radially inner core portion 41a and a gear-like or toothed radially outer end portion 49 which has a plurality of radially-extending projections, as shown in
A plurality of tongue members 46 are provided to extend from the platen 30 in a feed direction of the paper sheet P, and have respective distal end portions serving as contact portions which are held in contact wit the radially outer ends 45 of the respective driven rollers 41, as shown in
Each flexible shaft 42 supporting the corresponding driven roller 41 is fixed by the above-described inside and outside support members 47, 48 in a position relative to the drive roller 40 such that the overlap amount corresponds to a distance L1 (i.e., the same distance as in the above-described conventional feeding device) if the tongue member 46 as the overlap-amount limiter were absent in the present feeding device 10. This distance L1, larger than the above-described distance L2, is determined on the basis of an amount of spring load required for obtaining a predetermined amount of pressing force. In absence of the tongue member 46, the radially outer end portion 49 of each driven roller 41 overlaps with the radially outer end portion of the drive roller 40 by the distance L1, and the flexible shaft 42 holding the driven roller 41 does not receive any load, or is slightly flexed downwardly due to weight of the driven roller 41. It is noted that each of the annular grooves 43 of the drive roller 40 has a radial depth sufficiently large such that the driven roller 41 is not brought into contact with a bottom surface of each annular groove 43 of the drive roller 41 even in absence of the tongue member 46.
The overlap amount is reduced to correspond to the distance L2, by the provision of the tongue member 46 as the overlap-amount limiter which is brought into contact with the radially outer end 45 of the driven roller 41. As a result of the reduction of the overlap amount, the flexible shaft 42 on which the driven roller 41 is mounted is flexed upwardly, as shown in
The tongue member 46 as the overlap-amount limiter may be provided by a single piece which is formed of a resin, or alternatively, a hard material such as glass and stainless steel which is harder than the driven roller 41 so as to increase wear resistance of the tongue member 46 against the driven roller 41. Further, the tongue member 46 may be formed of the resin and the hard material, for example, such that the hard material is embedded in a contact surface of the distal end portion at which the tongue member 46 is held in contact with the radially outer end 45 of the driven roller 41, or the hard material has a cap-like shape and is provided to cover the distal end portion while the other portion of the tongue member 46 is formed of the resin.
There will be described an operation of the feeding device 10 which is constructed as described above. Each of he paper sheets P separated one by one from the media supply tray 22 enters between the first drive and driven rollers 28, 29 so as to be gripped by and between the rollers 28, 29. The paper sheet P gripped by the rollers 28, 29 is fed in a feed direction (corresponding to a rightward direction as seen in
When the leading end of the paper sheet P arrives in proximity of the second drive roller 40, the leading end of the paper sheet P is guided by upper surfaces of the tongue members 46 (which extend from the platen 30 in the feed direction), to the radially outer ends 45 of the driven rollers 41 which are held in contact with the distal end portions of the tongue members 46. The leading end of the paper sheet P then raises or upwardly displaces the driven rollers 41 by an amount corresponding to a sum of the distance L2 and a thickness of the paper sheet P, so as to enter between the radially outer end 44 of the drive roller 40 and the radially outer ends 45 of the driven rollers 41. In this instance, the paper sheet P receives, through the driven rollers 41, the spring load generated by a restoring force of the flexible shafts 42 which is based on the displacement of each driven roller 41 by the distance L1 rather than distance L2. In other words, the flexible shafts 42 and the weights of the driven rollers 41 serve as a biaser to bias the driven rollers 41 toward the drive roller 40, so that the paper sheet P is gripped by and between the drive and driven rollers 40, 41. Then, the paper sheet P thus gripped by and between the rollers 40, 41 is fed toward the media exit tray 31, while the printing operation is being effected by the recording portions 25a of the recording head 25. The paper sheet P is eventually received by the media exit tray 31, after the printing operation is completed.
In the present feeding device 10 constructed as described above, owing to the presence of the tongue member 46 as the overlap-amount limiter, the driven rollers 41 are raised even during absence of the paper sheet P between the drive and driven rollers 40, 41. Therefore, the amount, by which each driven roller 41 has to be upwardly displaced by the paper sheet P upon entrance of the paper sheet P between the rollers 40, 41, is equal to the distance L2 that is smaller than the distance L1, although the paper sheet P can be gripped by the rollers 40, 41 with a predetermined pressing force (ie., pressing force corresponding to the amount of the distance L1). That is, it is possible to reduce force resisting the paper sheet P upon its entrance between the rollers 40, 41, without reducing the pressing force acting on the paper sheet P after its entrance between the rollers 40, 41. The reduction in the resistance force against the entrance of the paper sheet P between the rollers 40, 41 is effective to avoid deflection of the paper sheet P upon the entrance and undesirable variation in the distance by which the paper sheet P is fed per each of the successive feed motions in the secondary scanning direction, thereby assuring smooth feed motions and resulting in a high printing quality.
There will be described a specific example of the arrangement of the second drive and driven rollers 40, 41. In this specific example of the arrangement, the driven rollers 41 are positioned relative to the drive roller 40 such that the distance L1 (i.e., the overlap amount in absence of the tongue member 46 as the overlap-amount limiter) is 1.0 mm, while the tongue member 46 is positioned relative to the driven rollers 41 such that the distance L2 (i.e., the overlap amount in presence of the tongue member 46 which upwardly forces the driven rollers 41) is 0.3 mm. In this arrangement, the driven rollers 41 are upwardly forced by the tongue member 46, the driven rollers 41 receive a spring load of 14 gF (=14×9.8×1031 3N. When the paper sheet P is positioned between the drive and driven rollers 40, 41, as shown in
While the distance L2 is set to be 0.3 mm in the above-described specific example, the distance L2 may be set to be another value which is larger than 0 and smaller than the value of L1 (0<L2<L).
In the above-described embodiment in which the tongue member 46 extends from the platen 30 to the annular groove 48 of the drive roller 40, the tongue member 46 can serve also to guide the leading end of the paper sheet P to the radially outer ends 45 of the driven rollers 41, thereby making it possible to rapidly and accurately introduce the paper sheet P between the drive and driven rollers 40, 41, without the paper sheet P being brought into contact with side faces of the drive and driven rollers 40, 41. It is noted that the tongue member 46 may be provided by a member independent from the platen 30 and attached to the platen 30, or may be formed integrally with the platen 30.
Further, in the above-described embodiment, the tongue member 46 is separated from the drive roller 40, so that the tongue member 46 is neither rotated nor even moved by rotation of the drive roller 40. Therefore, even though the tongue member 46 is arranged to be constantly held in contact with the driven roller 41 (which is not rotated together with the drive roller 40 during absence of the paper sheet P between the rollers 40, 41) during absence of the paper sheet P between the rollers 40, 41, the tongue member 46 and the driven roller 41 are not scratched or worn by their mutual contact, since the tongue member 46 and the driven roller 41 are not moved relative to each other during absence of the paper sheet P between the rollers 40, 41.
As described above, in the above-described embodiment, the overlap-amount limiter takes the form of the tongue member 46 which extends in the feed direction of the paper sheet P and which has the distal end portion as the contact portion positioned within each annular groove 43 of the second drive roller 40 and the proximal end portion positioned in a upstream side of the second drive roller 40. However, the overlap-amount limiter may take the form of a tongue member 146 which extends in a direction opposite to the above-described feed direction and which has a proximal end portion positioned in a downstream side of the second drive roller 40, as shown in
Further, the overlap-amount limiter may take the form of an annular member 246 which is accommodated in each annular groove 43 of the second drive roller 40, as shown in
The annular member 246 may be formed of rubber, resin or other elastic material and may have a cut portion 248 in its circumferential portion so as to be diametrically expandable. This arrangement makes it possible to fix the annular member 246 in the annular groove 43 of the drive roller 40 even after the drive and driven rollers 40, 41 have been attached to the main body 2, so that the drive and driven rollers 40, 41 can be attached to the main body 2 without the driven rollers 41 being biased by the flexible shafts 42 toward the drive roller 40. Further, this arrangement enables a conventional feeding device as shown in
While the flexible shafts 42 holding the respective second driven rollers 41 are arranged in series along a straight line in the above-described embodiment, the flexible shafts 42 may be arranged along two or more lines. Further, the driven rollers 41 do not have to be necessarily held independently of each other by respective flexible shafts, but may be commonly held by a single flexible shaft.
While the preferred embodiment of the invention has been described in detail by reference to the accompanying drawings, it is to be understood that the invention is not limited to the details of the illustrated embodiment, but may be embodied with various other changes, modifications and improvements, which may occur to those skilled in the art.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2003-084795 | Mar 2003 | JP | national |
| Number | Name | Date | Kind |
|---|---|---|---|
| 4231562 | Hori | Nov 1980 | A |
| 5291224 | Asano et al. | Mar 1994 | A |
| 5480130 | Suzuki et al. | Jan 1996 | A |
| 5606357 | Bekki | Feb 1997 | A |
| 5653439 | Rider et al. | Aug 1997 | A |
| 5669724 | Kato | Sep 1997 | A |
| 5897259 | Ahn | Apr 1999 | A |
| 5961234 | Uchikata | Oct 1999 | A |
| 6254078 | Taruki | Jul 2001 | B1 |
| 6305684 | Lightner et al. | Oct 2001 | B1 |
| 6325560 | Hirabayashi et al. | Dec 2001 | B1 |
| 6712463 | Matsumoto | Mar 2004 | B2 |
| Number | Date | Country |
|---|---|---|
| 57072538 | May 1982 | JP |
| A 6-15898 | Jan 1994 | JP |
| 09086749 | Mar 1997 | JP |
| A 9-86749 | Mar 1997 | JP |
| A 9-136470 | May 1997 | JP |
| Y2 2563146 | Nov 1997 | JP |
| A 10-67148 | Mar 1998 | JP |
| A 2000-335801 | Dec 2000 | JP |
| Number | Date | Country | |
|---|---|---|---|
| 20040190972 A1 | Sep 2004 | US |
