The present application claims priority under 35 U.S.C. § 119 to Japanese Patent Application No. 2007-097219, filed Apr. 3, 2007, entitled “Printer Apparatus.” The contents of this application are incorporated herein by reference in their entirety.
1. Field of the Invention
The present invention relates to a printer and a feeding apparatus for the printer.
2. Discussion of the Background
In a printer for printing on a sheet-like print medium, in order to improve the accuracy in feeding the print medium, it is known to place a guide member, which is formed in a cylindrical shape extending in the width direction of the print medium, in the way of feeding the print medium from a sheet supplying member to a print head, at a position capable of smoothly feeding the print medium to the print head. For example, JP-A-2003-252491 discloses such a printer. The contents of this publication are incorporated herein by reference in their entirety. Conventionally, a print medium is fed from a sheet supplying member to a print head by rotating a guide member 200 (see
Since the guide member 200 extends in the width direction for substantially the same length as the width of the print medium, however, twist and warpage are easily occurred in manufacturing the guide member 200 and an installation error is also easily caused in installing the guide member 200 to a printer because the guide member 200 is long in the width direction. Accordingly, when the guide member 200 is rotated with a state installed to the printer, the rotational trajectory of the periphery of the guide member 200 should be wavy as seen in the width direction so that the feeding distance of the print medium is hard to be constant. Therefore, there is such a problem that the accuracy in feeding the print medium is deteriorated.
According to one aspect of the present invention, a printer includes a supporting member, a print head and a guide member. The supporting member is configured to support a sheet print medium on an upper surface of the supporting member. The print head is provided to print on the sheet print medium fed onto the upper surface of the supporting member. The guide member is configured to guide the sheet print medium to feed the sheet print medium onto the upper surface of the supporting member. The guide member includes at least one guide collar around which the sheet print medium is wound and a guide bar provided in the at least one guide collar so that the at least one guide collar is rotatable around the guide bar.
According to another aspect of the present invention, a feeding apparatus for a printer includes a guide member which is configured to guide a sheet print medium to feed the sheet print medium onto an upper surface of a supporting member on which a print head is configured to print. The guide member includes at least one guide collar around which the sheet print medium is wound and a guide bar provided in the at least one guide collar so that the at least one guide collar is rotatable around the guide bar.
A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
The embodiments will now be described with reference to the accompanying drawings, wherein like reference numerals designate corresponding or identical elements throughout the various drawings.
Hereinafter, a printer 1 according to an embodiment of the present invention will be described with reference to
The printing section 10 mainly includes storage housings 11, 12, a print head 13, a guide rail 14, a holding member 15, and a platen 16. The storage housings 11, 12 are disposed on the left and right sides of the upper portion of the printer 1 to cover both ends of the guide rail 14. Installed in the storage housings 11, 12 are, for example, an operation panel for operating the printer 1, liquid ink to be ejected to the print medium 2, a maintenance station for conducting maintenance of the print head 13, but not shown.
The guide rail 14 extends in the left-right direction for a length longer than the width of the print medium 2 such that the left and right ends of the guide rail 14 are housed in the storage housings 11, 12. The guide rail 14 is provided with ridges and grooves which are formed in its front and rear surfaces to extend in the left-right direction for limiting movement in the forward, backward, upward and downward directions of the print head 13. The print head 13 has substantially an inverted U-like shape as seen from a right side, for example, and has a predetermined length in the left-right direction. The print head 13 is disposed to cover the upper surface and front and rear surfaces of the guide rail 14 and can be reciprocated in the left-right direction along the guide rail 14 extending in the left-right direction. The print head 13 has an ejection nozzles (not shown) for ejecting liquid ink droplets to the print medium 2 at a bottom portion of the print head 13 facing the platen 16.
The platen 16 extends in the left-right direction for a length longer than the width of the print medium 2 and is disposed below the print head 13. As shown in
As shown in
Further, the retaining section 30 has a symmetrical structure about a center line A extending in the upward-downward direction as shown in
The base 31 is formed substantially in a rectangular parallelepiped extending in the left-right direction for a length longer than the width of the print medium 2 to support the printing section 10 which is arranged above the base 31. The pair of supporting members 32 are each formed substantially in a rectangular parallelepiped extending in the forward direction and the rear ends of the supporting members 32 are fixed to the base 31 at lower portions near the left and right ends of the base 31, respectively. The pair of fixing arms 81 are each formed in a plate shape extending in the forward direction and the rear ends of the pair of fixing arms 81 are fixed to the base 31 at portions substantially the same as the supporting members 32 in the left-right direction and above the pair of supporting members 32.
As shown in
As shown in
The sheet supplying member 60 has a sheet supplying shaft 61 extending in the left-right direction onto which the print medium 2 unprinted is wound. The ends in the left-right direction of the sheet supplying shaft 61 are rotatably supported by the pair of supporting members 32. At the portions of the sheet supplying shaft 61 supported by the pair of supporting members 32, it is configured to apply rotational force to the sheet supplying shaft 61 and to brake the sheet supplying shaft 61 to prevent the sheet supplying shaft 61 from freely rotating.
The sheet winding member 70 includes a sheet winding shaft 71 extending in the left-right direction onto which the print medium 2 printed is wound. The ends in the left-right direction of the sheet winding shaft 71 are rotatably supported by a pair of supporting members (not shown). Similarly to the sheet supplying member 60 as mentioned above, at the portions of the sheet winding shaft 71 supported by the pair of supporting members, it is configured to apply rotational force to the sheet winding shaft 71 and to brake the sheet winding shaft 71 to prevent the sheet winding shaft 71 from freely rotating.
The second guide member 80 is made of, for example, a metallic material to have a cylindrical shape extending in the left-right direction for a length longer than the width of the print medium 2 and has a smooth peripheral surface. The second guide member 80 is placed at such a position as to smoothly introduce the print medium 2 to the slant surface of the platen 16.
The structure of the printer 1 has been described above. Hereinafter, the feeding of the print medium 2 will be described.
First, the order of feeding the print medium 2 will be described. As shown in
As shown in
When the print medium 2 is fed in the feeding direction by a predetermined distance from the state as shown in
In the first guide member 40, the both ends of the guide bar 41 are fixed not to rotate by the pair of the guide supporting arms 43 during the feeding of the print medium 2. Further, the periphery of the guide bar 41 has a smooth surface as compared to the surface of the print medium 2. Therefore, as shown in
According to this structure, the feeding distance of the print medium 2 from the sheet supplying member 60 in the feeding direction and the feeding distance of the print medium 2 at a position corresponding to the print head 13 are set equal, thereby improving the accuracy in feeding the print medium 2. In addition, since the print medium 2 can be fed with the guide bar 41 being in the fixed state i.e. without rotation of the guide bar 41, the feeding of the print medium 2 is not affected by the wavy rotational trajectory of the periphery of the guide member 41 which is caused during the feeding of the print medium 2 by the rotation of the guide bar 41 as the prior art. Therefore, at any position in the left-right direction of the print medium 2, the print medium can be fed for the same distance, thereby improving the accuracy in feeding the print medium 2.
Since the plural guide collars 42 are adapted to rotate with the print medium 2 relative to the periphery of the guide bar 41 during the feeding of the print medium 2, the plural guide collars 42 can rotate with the print medium 2 relative to the periphery of the guide bar 41 at respective different speeds. Therefore, the print medium 2 can be fed for the same distance at any position in the left-right direction without being affected by twist and warpage occurred in manufacturing the guide bar 41 or an installation error occurred in installing the guide bar 41 to the printer 1, thereby improving the accuracy in feeding the print medium 2.
Also in the first guide member 50, the plural guide collars 52 are adapted to rotate with the print medium 2 relative to the periphery of the guide bar 51 during the feeding of the print medium 2, the print medium 2 can be fed for the same distance at any position in the left-right direction without being affected by twist and warpage occurred in manufacturing the guide bar 51 or an installation error occurred in installing the guide bar 51 to the printer 1, thereby enabling the print medium 2 printed to be wound up with the print medium 2 being uniform in the left-right direction.
Since this embodiment is the printer 1 for printing on the print medium 2 having a long width about 3 meters, the printer 1 is required to include the guide bar 41 extending in the left-right direction for a length longer than the width of the print medium 2. The feeding accuracy can be improved by an inexpensive and easy method of covering the guide bar 41 with the plural guide collars 42 of which cost is lower than the cost for manufacturing a guide bar 41 which extend exactly straight for the purpose of improving the feeding accuracy.
In the aforementioned embodiment, the plural guide collars 42 are preferably arranged to be spaced from each other in the left-right direction to allow the guide collars 42 to freely rotate relative to each other around the guide bar 41. Further, the covered periphery of the guide bar 41 may depend on the width of the print medium 2 and may not be the whole.
In the aforementioned embodiment, there is no particular limitation on the number of the guide collars 42 to be mounted on the guide bar 41 and on the size of each guide collar 42 in the left-right direction.
In the aforementioned embodiment, the printer 1 according to the embodiment of the present invention can print on a print medium 2 having a net-like structure.
In the aforementioned embodiment, a member for holding the print medium 2 on the platen 16 is not limited to the holding member 15. For example, an arrangement in which the platen 16 has plural vacuum holes and air is sucked through the plural vacuum holes so as to hold the print medium 2 on the platen 16 may be employed.
In the printer according to the embodiment of the present invention, since the guide member includes a guide bar which is formed in a cylindrical shape extending in the width direction and a guide collar which is formed in a cylindrical shape coaxially with the guide bar to cover the periphery of the guide bar and which can freely rotate relative to the guide bar, the guide collar can rotate with the print medium relative to the surface of the guide bar during the feeding of the print medium in the predetermined direction so that the feeding of the print medium is not affected by the wavy rotational trajectory which is caused by the rotation of the guide bar, thereby improving the accuracy in feeding the print medium. Further, the rotation of the guide bar is stopped during the feeding of the print medium. Since the guide bar is stopped from rotating, the feeding of the print medium can be prevented from being affected by twist and warpage occurred in the guide member as mentioned above as the prior art.
Since the guide member includes a plurality of guide collars each of which is formed in a cylindrical shape coaxially with the guide bar to cover the periphery of the guide bar and can freely rotate relative to the guide bar such that the plurality of guide collars are aligned in the width direction, the plural guide collars rotate with the print medium relative to the surface of the guide bar, whereby twist and warpage occurred in manufacturing the guide bar or an installation error occurred in installing the guide bar to the printer can be absorbed by the relative rotation of the plural guide collars at respective different speeds, thereby improving the accuracy in feeding the print medium.
Furthermore, since the guide member is supported at its both ends by supporting arms which are pivotally movable in the upward-downward direction so that the print medium is held in the tensioned state by the pivotal movement of the guide member in the upward-downward direction because of its own weight, the feeding distance of the print medium from the sheet supplying member in the feeding direction and the feeding distance of the print medium at a position corresponding to the print head are set equal so as to prevent the print medium from slacking in the predetermined direction, thereby improving the accuracy in feeding the print medium.
Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.
Number | Date | Country | Kind |
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2007-097219 | Apr 2007 | JP | national |