JP2011046471A - Roll paper conveying device and recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that, in a constitution of holding a paper tube of roll paper by a pair of roll paper holders, the center position of the paper tube to be held is changed in the vertical direction according to the rotational phase of the roll paper holders, and if the rotational phase is different in the pair of roll paper holders, the center axis of the paper tube is deflected with respect to an image forming roller arranged orthogonal to the vertical direction, and thus, the roll paper meanders causing image degradation. <P>SOLUTION: In order to prevent occurrence of any rotational phase deviation in a pair of roll paper holders, a user is invited to consciously set the phase of the roll paper holders. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a roll paper transport apparatus for feeding and transporting a wound roll sheet to an image forming area such as a printer, and a recording apparatus including the roll paper transport apparatus.

  A printer that records an image on a recording medium based on image information, a recording device such as a copying machine or a facsimile, a composite device to which other functions such as a printer function, a facsimile function, a document reading function or an imaging function are added, and A system apparatus configured by connecting a recording apparatus to a host machine such as a computer is used. One form of a recording apparatus used in these apparatuses is one that forms an image on a sheet of roll-shaped recording paper or film (hereinafter referred to as roll paper). In such a recording apparatus, a sheet conveying apparatus for feeding and conveying the sheet from a roll holder portion that holds roll paper to an image forming area is used. The “sheet” in the present application refers to a recording medium, and the material thereof is not limited to paper or a plastic sheet.

  In a conventional roll paper holding device, a roll paper holding structure is configured by loading a pair of holding members (called flanges) at both ends of the roll paper, and fixing the roll paper tube and the holding member to non-rotation. A configuration has been proposed in which the roll holding member is supported by the receiving portion of the apparatus main body and the roll paper is rotatably held (see Patent Document 1). In this proposal, a rib (paper tube lock portion) that is elastically deformed in a radial direction integrally formed from a loading portion of the flange that is inserted into the paper tube of the roll paper bites into the paper tube by elastic force, thereby the flange and the roll. The paper is fixed in rotation. In that case, it is desirable to firmly rotate and fix the flange and the roll paper, and for this purpose, it is necessary to make the elastic force generated in the rib as strong as possible. On the other hand, the stronger the elastic force, the greater the insertion force when inserting the flange into the paper tube of the roll paper, and the operability for the user is significantly reduced. Therefore, in the configuration of Patent Document 1, the elastic force is set based on the balance between the insertion force and the locking force.

JP 2006-205606 JP

  In the configuration described above, since the paper tube of the roll paper is supported by the rib, the elastic deformation amount of the rib due to the weight of the roll paper changes depending on the phase of the flange. In particular, for the purpose of reducing the insertion force, the rib is easily elastically deformed against the weight of the roll paper radius component. That is, when the ribs are arranged in the vertical direction, the roll paper's own weight is collectively applied to the ribs, so that the amount of elastic deformation of the ribs is increased, and the center of the roll paper is lowered in the vertical direction with respect to the flange center. On the other hand, when there is a rib at a position deviated from the vertical direction, the influence of the roll paper's own weight is relatively small and the amount of elastic deformation is small, and the center of the roll paper is not so lowered in the vertical direction with respect to the flange center. Absent.

  That is, the center position of the roll paper changes with the rotational phase of the flange. In particular, when the phase relationship of the ribs is different between the pair of flanges, the center axis of the paper tube is shaken with respect to the image forming roller disposed at right angles to the vertical direction. This phenomenon causes the roll paper to meander and cause image degradation.

  A pair of recording medium holders for supporting a paper tube of a recording medium wound in a roll form from both ends in the axial direction, the pair of recording medium holders being inserted into the inner surface of the paper tube of the roll-shaped recording medium At least one place on the outer peripheral surface having a shape with a radial dimension larger than the diameter of the roll-shaped recording medium, and a plurality of paper tube lock portions that restrain the paper tube in the rotation direction and the axial direction. And the paper viewed from one of the paper tube axial directions when the orientation of the flat part at any one location in the pair of recording medium holding parts is aligned in the same plane. A recording medium holding device configured such that the angle phases of the tube lock portions are the same.

  The roll paper holding device according to the above, wherein the paper tube lock portions are arranged at equal intervals from the center of the recording medium holding portion.

  The roll paper holding device according to the above, wherein the paper tube lock portion is disposed symmetrically with respect to a straight line that bisects the flat portion.

  The roll paper holding device as described above, wherein the pair of recording medium holding portions has a common left and right shape.

  According to the present invention, it is possible to provide the user with a shape that makes it easy to intentionally adjust the phase of the flange, and to form a shape that guides the user to intentionally adjust the phase. That is, the phase shift of the left and right flanges is eliminated with an inexpensive configuration, and the image when printing on roll paper is stabilized.

The front view of the roll paper holder in a present Example. The elements on larger scale of the paper tube lock part of a roll paper holder. The schematic sectional drawing of the state which inserted the roll paper holder in roll paper. FIG. 2 is a perspective view illustrating a schematic configuration of an ink jet printer that is an example of a recording apparatus including a paper feeding device according to the present embodiment. FIG. 3 is a perspective view showing roll paper attachment of the printer. Sectional drawing which shows schematic structure of the printer of FIG. The front view of the roll paper holder which showed another Example. The front view of one roll paper holder which showed another Example. The front view of the other roll paper holder in the Example of FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 4 is a perspective view of an ink jet printer which is an example of a recording apparatus provided with a sheet feeding device according to an embodiment of the present invention. FIG. 5 is a perspective view showing a configuration of a main body attachment portion of roll paper as a printing medium. FIG. 6 is a schematic cross-sectional view of an ink jet printer which is an example of a recording apparatus provided with a paper feeding device according to an embodiment of the present invention.

  The printing medium setting operation in this embodiment will be described. For the printing medium of this embodiment, roll paper R, which is continuous paper wound in a roll shape, is used. As shown in the perspective view of FIG. 5, the roll paper R passes through the spool shaft 32 through the paper tube S at the winding center thereof, and the reference side of the reference side roll paper holder 30 disposed on the spool shaft 32. The side loading portion 31 is fixed and held by biting into the inner wall of the paper tube S by the elastic force in the radial direction. The fixing and holding on the paper tube S will be described in detail later. The reference side roll paper holder 30 is fixed to the spool shaft 32 so as not to rotate. Further, the non-reference side roll paper holder 34 is passed through the spool shaft 32 from the opposite side of the reference side roll paper holder 30 and set on the paper tube S so as to sandwich the roll paper R. The non-reference-side roll paper holder 34 also has a non-reference-side loading portion 35, which is fixedly held to the paper tube S with an elastic force in the radial direction. Then, as shown in FIG. 4, the roll paper R is also rotatably held by rotatably supporting both ends of the spool shaft 32 on the printer apparatus main body 1. In the ink jet printer of this embodiment, the roll paper R is set on the right side when viewed from the front of the user. As will be described in detail later, since the recording head 11 needs to move on the recovery means 23 even during printing, the paper is brought closer to the recovery means 23 side in consideration of the movement time of the carrier 12. This is because the printing speed is shortened when the printer is set. In the following description, the end portion of the roll paper will be described as Rp.

  Next, the paper feeding operation will be described. The paper leading edge Rp of the roll paper R set at the position of FIG. 6 is guided to the transport port 2 by the user's hand. Then, when the user rotates the roll paper R in the counterclockwise rotation (CCW) direction, the roll paper leading end Rp is sent downstream through the conveyance path. In the middle of the conveyance path, a reflection type paper detection sensor 41 is provided. When the passage of the leading edge of the paper is detected, the image forming roller 9 starts to rotate in the CCW direction which is the paper conveyance direction. Subsequently, the leading edge Rp of the roll paper fed downstream by the user's hand reaches the nip portion of the image forming roller pair 9, 10, and the sheet is sandwiched between the image forming roller pair 9, 10. It is transported up. At this time, the end detection sensor 42 mounted on the carrier 12 detects the passage of the sheet, and confirms that the sheet has surely reached the platen. In the subsequent operations, the sheet is automatically conveyed by the image forming roller pair 9 and 10, and at this point, the user releases his hand from the roll sheet. The roll paper R after the user releases the hand is pulled and carried around when the paper is conveyed in the downstream direction by the pair of image forming rollers 9 and 10.

  Next, an image forming unit for the roll paper R conveyed to the platen 19 will be described. Reference numeral 1 denotes an ink jet printer main body, 3 denotes an image recording unit, and the image recording unit 3 includes a recording head 11, a carrier 12 on which the recording head 11 is placed, and a platen 19 provided to face the recording head 11. It is constituted by. The recording head 11 has a plurality of nozzle rows (not shown) in the sub-scanning direction of the surface facing the printing surface, and discharges ink of different colors for each nozzle row. The recording head 11 is supplied with ink of each color from an ink tank 14 via a supply tube 13 for each color nozzle. Further, the carrier 12 is supported so as to be slidable along a guide shaft 16 and a guide rail (not shown) that are fixed to both ends of the frame 15 of the apparatus main body 1 and arranged parallel to each other. An image is recorded on the sheet by ejecting ink from the recording head 11 while reciprocating the carrier 12 toward the roll paper conveyed to the image recording unit 3. When an image is recorded by scanning one line by forward or backward movement of the carrier 12 in the image recording unit 3, the roll paper is fed by a predetermined pitch in the transport direction by the image forming roller pair 9, 10, and the carrier 12 is moved again. Record the next line. By repeating this, an image is recorded on the entire page, and the recorded portion is conveyed onto the paper discharge tray 22. By the way, as described above, the image forming roller 9 repeatedly accelerates, decelerates, and stops for each line and feeds the sheet, so that the roll paper R keeps rotating due to its inertial force at the time of deceleration or stop. The power to work. Therefore, a rotational load called back tension is always given to the roll paper R, and the roll paper R can be stably conveyed without slackening by applying an acting force opposite to the conveyance force by the image forming roller 9 to the roll paper. It is carried out. Stabilization of such transport is important for printers that perform recording operations for each line. If the transport is not stable and "overfeed" or "underfeed" occurs, streaks occur at the line joints. . Therefore, continuous application of a constant back tension to the conveyed roll paper R leads to stable image formation. In this example, this rotational load is set to be 1 kgf.cm on the axis of the roll paper R, and is generated by the torque limiter 33 on the axis of the spool shaft 32 shown in FIG.

  Further, reference numeral 23 shown in FIG. 6 denotes a recording head recovery means. The head recovery means 23 can face the recording head 11 when the recording head 11 moves to a home position provided near one end of the moving range. In the position. Then, the head recovery means 23 is operated during standby, before and after the recording operation, or between recordings for each line to cause the recording head 11 to perform operations such as capping, suction, and wiping. The performance of the recording head 11 can be maintained by preventing clogging and the like. When the image recording is completed, the sheet is conveyed to a predetermined cutting position by the image forming roller pair 9 and 10 and is cut by the cutter 21.

  The above is a series of flow from roll paper setting to paper discharge. Next, the detailed configuration of the print medium setting unit, which is a feature of the present embodiment, will be described with reference to FIGS. FIG. 1 is a front view of a roll paper holder in the present embodiment, FIG. 2 is a partially enlarged view of a paper tube lock portion of the roll paper holder, and FIG. 3 is a schematic cross-sectional view of the roll paper holder inserted into the roll paper. The loading sections 31 and 35 of the roll paper holders 30 and 34 are inserted into the paper tube S of the roll paper R from both ends. The loading sections 31 and 35 have a plurality of paper tube lock sections 50 that are elastically deformed, and are arranged at four locations (50a) at a phase of 90 ° at equal intervals from the center of the roll paper holder (the center of rotation of the roll paper holder). ~ 50d) present. Note that the number of paper tube lock portions is not necessarily four, but generally three or more. Since the diameter L of the circle connecting the apexes of the four paper tube lock portions 50 is set larger than the inner diameter L ′ of the paper tube, when inserting the loading portions 31 and 35 into S, Then, the paper tube locking portions 50a to 50d are elastically deformed to generate an elastic force that presses against the paper tube S. With this pressing force, the paper tube lock portions 50a to 50d are bitten into the paper tube S, and the roll paper holders 30 and 34 and the roll paper R are held stationary.

  After the roll paper holders 30 and 34 are fitted to both ends of the roll paper R, the roll paper R may be temporarily placed on a temporary placement table (4 in FIG. 6) or a floor of the printer body. Therefore, the outer peripheral surface 51 of the roll paper holder needs to have a shape having a radial distance larger than the diameter of the roll paper R. If the roll paper rolls during temporary placement, the roll paper may be unwound or scratched on the print surface of the roll paper surface. For this reason, the outer peripheral surface 51 of the roll paper holder is usually devised so that it does not roll by providing one or more plane portions with a straight bisector as a straight line passing through the center (center of gravity) of the roll paper holder. Has been. In this example, one flat part 51a is provided, and the shape is such that the user is intentionally guided to the flat part of the left and right flanges downward in the vertical direction.

  By the way, in this embodiment, the flat surface portion 51a is provided perpendicular to a straight line connecting the paper tube lock portions 50a and 50c facing each other across the center of the roll paper holder. This relationship does not change between the pair of roll paper holders 30 and 34. This intention is that the angle phase of the paper tube locking portions 50a to 50d is changed to the arrows shown in FIG. 3 by guiding the user so that the flat portions 51a of the pair of roll paper holders 30 and 34 are vertically downward. This is because they are aligned when viewed from the Y direction. The effect of this is that the deformation amount of each of the paper tube lock portions 50a to 50d that elastically deforms under the weight of the roll paper is the same between the pair of roll paper holders 30 and 34 in all rotation angle phases. That is, the vertical positions of the roll centers C and C ′ held by the pair of roll paper holders 30 and 34 are aligned at any rotational angle phase, and the roll paper center axis CC ′ is aligned with the image forming roller 9. Parallelism is maintained. Therefore, if the configuration of this embodiment is used, roll paper meandering during image recording can be suppressed and image quality improvement can be expected.

  Another embodiment will be described with reference to FIG. In FIG. 7, the paper tube lock portions 50e to 50j are arranged at six locations at equal intervals of 60 °. Further, the outer peripheral portion 51 of the roll paper holder has six flat portions 51e to j, and a straight line that bisects the adjacent paper tube lock portions 50e to 50j into two halves is perpendicular to the flat portions 51e to j. They are arranged so that they are equally divided. This relationship is common to a pair of roll paper holders. In this case, if any one of the flat portions 51e to 51j of the pair of roll paper holders is combined, the center axis misalignment problem due to the angular phase of the roll paper holder does not occur as in the previous embodiment.

  Incidentally, the shape of the roll paper holder represented by FIG. 1 and FIG. 7 described above is most preferably a common shape, for example, a pair of roll paper holders. This means that the distinction between the attachment of the pair of roll paper holders can be eliminated, and the user's workability can be improved.

  Further, another embodiment will be described with reference to FIGS. 8 and 9 are views of the pair of roll paper holders as viewed from the front. The paper tube lock portions 50k to 50o and 50k 'to 50o' in the pair of roll paper holders are not arranged at equal intervals. Like the roll paper holder shown in FIGS. 1 and 7, it is more convenient to arrange the paper tube lock portions at equal intervals because the eccentricity due to the rotation of the roll paper centers C and C ′ can be reduced. However, this proposal shows that it is not limited to this.

  Further, as shown in FIGS. 8 and 9, the angle phases of the paper tube lock portions 51k to 51o and 51k ′ to 51o ′ of the roll paper holder are different from each other when viewed from the front. However, as shown in FIG. 3 or FIG. 5, the roll paper holders are attached so that the flat portions 51k and 51k ′ of the respective roll paper holders are on the same plane (vertically below) and face each other with the roll paper interposed therebetween. In this case, the paper tube lock portions of the roll paper holder viewed from the Y direction in FIG. 3 are arranged to have the same angle phase. Also in such an embodiment, the amount of deviation in the vertical direction of C and C ′ accompanying the rotation is equal between the pair of roll paper holders, so it can be said that it corresponds to the problem in this case. However, in the roll paper holder represented by FIG. 1 or FIG. 7, when the paper tube lock portion is symmetrically arranged with respect to the perpendicular bisector of the plane portion, the pair of roll paper holders may be shared. Although it was possible, in the case of this embodiment, it cannot be made a common shape. In that respect, it can be said that the roll paper holder represented in FIGS. 1 and 7 is superior in terms of user workability.

  Further, in the present embodiment, the same effect can be expected with respect to the paper tube lock portion not only by the elastic deformation of the mold as described above but also in a configuration using a spring or a configuration fixed to a substantially rigid shape.

C Reference roll center position
C 'Center position of non-reference side roll paper
L Natural diameter of the cigarette lock
L 'Inner diameter of paper roll S R Roll paper (printing medium)
Rh Roll paper Reference side edge S Paper tube 1 Printer device main body 2 Paper feed port 3 Image recording unit 4 Roll paper temporary placement table 9 Image forming roller 10 Image forming pinch roller 11 Recording head 12 Carrier 13 Supply tube 14 Ink tank 15 Main body Frame 16 Guide shaft 19 Platen 21 Cutter 22 Paper discharge tray 23 Head recovery means 30 Reference side roll paper holder 31 Reference side loading portion 32 Spool shaft 33 Torque limiter 34 Non-reference side roll paper holder 35 Non-reference side loading portion 41 Paper detection sensor 42 Edge detection sensors 50 (a to o), 50 (a ′ to o ′) Paper tube lock portion 51 Outer peripheral surface of roll paper holder 51 (a to k), 51 k ′ Flat portion on outer peripheral surface

Claims (4)

A pair of recording medium holding units that support the paper tube of the recording medium wound in a roll shape from both ends in the axial direction,
The pair of recording medium holding units includes a loading unit that is inserted into the inner surface of the paper tube of the roll-shaped recording medium, a plurality of paper tube locking units that restrain the paper tube in the rotational direction and the axial direction, and the roll-shaped recording medium. The outer peripheral surface having a shape with a radial dimension larger than the diameter of the medium has at least one flat portion,
The paper tube lock as viewed from any one of the paper tube axial directions when the orientation of the flat portion at any one position in the recording medium holding portion is aligned in the same plane between the pair of recording medium holding portions. Recording medium holding device configured to have the same angular phase of the portions.   2. The recording medium holding device according to claim 1, wherein the paper tube locking parts are arranged at equal intervals in the circumferential direction with respect to the rotation center of the recording medium holding part.   The recording medium holding device according to claim 1, wherein the paper tube lock portion is disposed symmetrically with respect to a straight line that bisects the plane portion.   The recording medium holding device according to claim 3, wherein the pair of recording medium holding portions have a common left and right shape.

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