JP2013100154A - Roll medium holding mechanism, roll paper feeder, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a roll medium holding mechanism in which a position of a support member is regulated without provision of a locking mechanism for the support member, enabling prevention of movement of the support member.SOLUTION: A flange 12 as a holding member is composed by a shaft core part 12a in contact with an inner circumference of a core tube 10b of roll paper 10a for supporting it and a guide part 12b in contact with an end surface 10c of the roll paper 10a. The flange 12 is provided with a plurality of support members 14 which opens/closes in the radial direction, at a plurality of locations in the circumferential direction. When the roll paper 10a whose core tube 10b has a large inner diameter is mounted to the flange 12, the support member 14 abuts to the outer circumferential surface of the shaft core part 12a and the inner circumferential surface of the core tube 10b, and if the diameter of the core tube 10b is small, the support member 14 is moved causing an end of the core tube 10b to abut to the support member 14, thus regulating a retracted position of the support member 14.

Description

  The present invention relates to a roll medium holding mechanism, a roll paper feeding device using the same, and an image forming apparatus such as a printer, a plotter, a facsimile, and a copying machine equipped with the paper feeding device.

  FIG. 8 is a cross-sectional view showing an example of a conventional roll medium holding mechanism. In the figure, 10a is a roll paper, 10b is a roll paper core tube, 12a is a shaft core part, 12b is a guide part, 13 is a drive shaft, 14 is a support member, and 15 is an elastic member. In this mechanism, when the diameter of the core tube 10b of the roll paper 10a is small, the support member 14 is rotated (rotation fulcrum 14a) and retracted outside the end of the roll paper 10a (the lower side of the figure). Support member 14). However, even if the position of the support member 14 is regulated by a lock mechanism (not shown), the lock is released when the support member 14 is set in a state where the support member 14 is not sufficiently locked or when the user sets the roll paper 10a. In this case, the support member 14 falls inward from the end of the roll paper 10a (see the support member 14 on the upper side in the figure), and damages the roll paper 10a as indicated by the arrow D in the figure, for example. Sometimes.

  Accordingly, an object of the present invention is to provide a mechanism that can prevent the movement of the support member by restricting the position of the support member without providing a lock mechanism for the support member.

  The roll medium holding mechanism of the present invention is a roll medium holding mechanism comprising: a holding member for holding a roll-shaped medium; and a plurality of support members that are movably attached to the holding member. When the diameter of the core tube is large, the support member contacts the outer peripheral surface of the shaft core portion of the holding member and the inner peripheral surface of the core tube, and the diameter of the core tube of the roll-shaped medium is small In this case, the support member is moved so that the end portion of the core tube abuts on the support member to restrict the retracted position of the support member.

  According to the present invention, it is possible to prevent the support member from moving by regulating the position of the support member without providing a support member locking mechanism.

1 is a perspective view illustrating an overall configuration of an example of an image forming apparatus that is an object of the present invention. Conceptual sectional view The perspective view which shows the flange used with the roll-medium holding mechanism based on this invention Figure (A) and enlarged view (B) showing a state where a roll paper having a large inner diameter of the core tube is attached to the flange The figure which shows the state which attached the roll paper where the inside diameter of the core pipe is small to the flange The figure which shows the positional relationship in the retraction position of a support member, a support member contact part, and the rotation fulcrum of a support member. The figure which shows the position of the support member contact part in the state in which the core pipe of roll paper is located in the back | inner side in the axial direction of a drive shaft rather than an end surface. Sectional drawing which shows an example of the conventional roll medium holding mechanism

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, elements common to those in the conventional example shown in FIG.

  FIG. 1 is a perspective view showing the overall configuration of an example of an image forming apparatus that is an object of the present invention, and FIG. 2 is a conceptual sectional view of the same. In the illustrated image forming apparatus, spool bearing bases 101a and 101b are roll papers 10a1 and 10a2 as sheet rolls on which long paper is wound (hereinafter, unless otherwise required, simply roll paper 10a and A sheet roll support portion that supports the paper 10 so that it can be fed out. Further, as shown in the front-rear direction X perpendicular to the vertical direction Z, the “front” side facing the left side of the apparatus main body 1 in FIG. 1 is the front surface 1F (front) side, and the “rear” side facing the right side is the rear (back). On the side. A direction perpendicular to the vertical direction Z and the front-rear direction X and penetrating through the paper surface of FIG. 1 is a main scanning direction Y (see FIG. 2), and corresponds to the sheet width direction (paper width direction).

  The image forming unit 3 is configured to perform image formation by an ink jet recording method. As shown in FIG. 2, the illustrated apparatus is an ink jet recording apparatus and a serial type ink jet recording apparatus.

  A guide rod 18 and a guide rail 19 are spanned on a side plate (not shown) in the apparatus main body 1 at a portion corresponding to the image forming unit 3 inside the apparatus main body 1. The guide rod 18 and the guide rail 19 hold a carriage 20 so as to be slidable in the main scanning direction Y. The carriage 20 is mounted with a liquid recording head (not shown) that is a liquid discharge head for discharging ink droplets of each color of black (K), yellow (Y), magenta (M), and cyan (C). . In addition, although not shown, each liquid recording head is integrally provided with a sub tank that supplies ink to each liquid recording head.

  A main scanning mechanism that moves and scans the carriage 20 in the main scanning direction Y is connected to a drive motor 21 disposed on one side of the main scanning direction Y (upwardly diagonally left in the figure) and an output shaft of the drive motor 21, and is driven. A driving pulley 22 that is rotationally driven by the motor 21, a driven pulley 23 that is disposed on the other side in the main scanning direction Y (right obliquely downward in the drawing), and a belt member that is wound between the driving pulley 22 and the driven pulley 23. 24. The driven pulley 23 is tensioned outward by a tension spring (not shown), that is, in a direction away from the drive pulley 22.

  A part of the belt member 24 is fixedly held by a belt fixing portion provided on the back side of the carriage 20, thereby pulling the carriage 20 in the main scanning direction Y.

  An encoder sheet (not shown) for detecting the main scanning position of the carriage 20 is arranged along the main scanning direction Y of the carriage 20, and the above-described encoder sensor (not shown) provided on the carriage 20 is used. Read the encoder sheet. In the main scanning area of the carriage 20, in the recording area, the paper 10 fed out and conveyed from the upper roll paper 10a or the lower roll paper 10a as described later is moved by the paper feed mechanism (not shown). 1 is intermittently conveyed in the sub-scanning direction (the front direction Xa of the front-rear direction X in FIG. 1) orthogonal to the main scanning direction Y.

  In addition, a maintenance / recovery mechanism 25 that performs maintenance / recovery of each liquid recording head in the carriage 20 is disposed in one end side region (downwardly to the right in the drawing) of the main scanning region. A main cartridge 26 containing each color ink to be supplied to the sub-tank of each liquid recording head is detachably attached to the apparatus main body 1.

  Further, as shown in FIG. 1, a cutter 27 is disposed as a sheet cutting unit for cutting a sheet on which an image is recorded by the image forming unit 3 into a predetermined length. The cutter 27 is fixed to a wire or timing belt that is stretched between a plurality of pulleys (one of which is connected to the drive motor 21). The belt is moved in the main scanning direction Y so that the sheet is cut into a predetermined length.

  FIG. 3 is a perspective view showing a flange used in the roll medium holding mechanism according to the present invention. As shown in the figure, the flange 12 is composed of a shaft core portion 12a that contacts and supports the inner periphery of the core tube 10b of the roll paper 10a, and a guide portion 12b that contacts the end surface 10c of the roll paper 10a. The shaft core portion 12a and the guide portion 12b may be formed integrally or separately.

  The flange 12 is provided with support members 14 that open and close in the radial direction at a plurality of locations in the circumferential direction (three in the figure are provided, but the number is not limited to this example). The support member 14 has a rotation fulcrum 14a in the circumferential direction inside the guide portion 12b, and rotates to open and close. Thereby, the diameter of the axial part 12a is variable.

  4A and 4B show a state in which the roll paper 10a having a large inner diameter of the core tube 10b is attached to the flange 12, and an enlarged view (B). The support member 14 has a support member abutting portion 14b that protrudes toward the drive shaft 13 on the surface of the shaft core portion 12a. In addition, when the support member 14 is tilted toward the shaft core portion 12a, a portion corresponding to the support member contact portion 14b of the shaft core portion 12a so that the support member contact portion 14b does not interfere with the shaft core portion 12a. Is formed as a concave portion (a housing portion for the support member contact portion 14b) as shown in the figure.

  In this state, the support member abutting portion 14b is housed in the concave portion (housing portion 12c) of the guide portion 12b, and the size of the housing portion 12c in the radial direction (the dimension including the elastic member 15 in the illustrated example). Since the height (diameter in the radial direction) of the support member abutting portion 14b is larger as shown in the figure, the support member abutting portion 14b can be accommodated without being brought into contact with the shaft core portion 12a of the flange 12. Therefore, the support member 14 can be tilted so as to face the shaft core portion 12a. At this time, the support member 14 is sandwiched between the inner peripheral surface of the core tube 10 b of the roll paper 10 a and the elastic member 15 on the shaft core portion 12 a of the flange 12.

  FIG. 5 is a diagram illustrating a state in which the roll paper 10 a having a small inner diameter of the core tube 10 b is attached to the flange 12. In this state, the support member 14 is housed in the guide portion 12b of the flange 12, and the support member contact portion 14b protrudes outward from the surface of the guide portion 12b on the roll paper 10a side as shown in the figure. It is in the state.

  FIG. 6 is a diagram illustrating a positional relationship between the support member 14, the support member contact portion 14 b, and the rotation fulcrum 14 a of the support member 14 at the retracted position. In this state, the support member abutting portion 14b protrudes from the support member 14 by a predetermined distance a, and is in a position radially outward from the rotation fulcrum 14a of the support member 14. The support member abutting portion 14b is located at the same height as the core tube 10b of the roll paper 10a, and is set so that the core tube 10b and the support member abutting portion 14b abut. Accordingly, the upper end of the support member 14 is prevented from falling to the left side in the drawing and coming into contact with the side surface of the roll paper 10a.

  FIG. 7 is a diagram illustrating the position of the support member contact portion 14b in a state where the core tube 10b of the roll paper 10a is located on the back side (left side in the drawing) in the axial direction of the drive shaft 13 with respect to the end surface 10c. In this state, the width of the support member abutting portion 14b (referring to the dimension in the axial direction of the drive shaft 13) is larger than the distance c at which the core tube 10b of the roll paper 10a is recessed from the end face 10c (core). If it is a dimension that protrudes to a position where it can contact the end of the tube 10b), the end surface 10c of the roll paper 10a can be suppressed without the support member 14 coming into contact with the end surface 10c of the roll paper 10a. Since the front end portion of the support member 14 is formed in a slope shape with a lower front end side (back side in the axial direction of the drive shaft 13) as can be seen in FIG. 7, the end surface 10c of the roll paper 10a is damaged. It is possible to suppress without any problems.

  The support member contact portion 14b comes into contact with the end surface 10c of the roll paper 10a by setting the support member contact portion 14b at a position lower than the outer diameter of the core tube 10b (inner diameter side of the core tube 10b). I can prevent that.

  The present invention is not limited to the above-described embodiments, and many modifications can be made by those having ordinary knowledge in the art within the technical idea of the present invention.

DESCRIPTION OF SYMBOLS 1: Apparatus main body 3: Image forming part 10: Paper 10a, 10a1, 10a2: Roll paper 10b: Core pipe 10c: End face 12 of a core pipe: Flange 12a: Shaft core part 12b: Guide part 12c: Storage part (concave part)
13: Drive shaft 14: Support member 14a: Rotating fulcrum 14b: Support member contact portion 15: Elastic member 18: Guide rod 19: Guide rail 20: Carriage 21: Drive motor 22: Drive pulley 23: Driven pulley 24: Belt Member 25: Maintenance / recovery mechanism 26: Main cartridge 27: Cutter 101a, 101b: Spool bearing base

JP 2007-290864 A

Claims (8)

A holding member for holding a roll-shaped medium;
A plurality of support members movably attached to the holding member;
In a roll medium holding mechanism comprising:
When the diameter of the core tube of the roll-shaped medium is large, the support member contacts the outer peripheral surface of the shaft core portion of the holding member and the inner peripheral surface of the core tube,
When the diameter of the core tube of the roll-shaped medium is small, the support member is moved so that the end portion of the core tube abuts on the support member and restricts the retracted position of the support member.
A roll medium holding mechanism. The roll medium holding mechanism according to claim 1,
The support member has a contact portion to the core tube of the roll-shaped medium or the roll-shaped medium,
The contact portion is located at a position where the contact portion protrudes from the support member toward the roll-shaped medium when the support member is in the retracted state, and has a radius greater than the rotation center of the support member. Located outside in the direction,
A roll medium holding mechanism. The roll medium holding mechanism according to claim 2,
The contact portion of the support member is at a position lower than the outer diameter of the core tube,
A roll medium holding mechanism. The roll medium holding mechanism according to claim 2,
Even when the core tube of the roll paper is inside the end surface of the roll paper, the contact portion of the support member in the retracted state has a protruding amount that contacts the core tube of the roll paper.
A roll medium holding mechanism. In the roll medium holding mechanism according to any one of claims 1 to 4,
When the diameter of the core tube of the roll-shaped medium is large and the support member is in contact with the outer peripheral surface of the shaft core portion of the holding member and the inner peripheral surface of the core tube, the contact portion can be stored. A relief portion is provided in the shaft core portion of the holding member,
A roll medium holding mechanism.   A roll sheet feeding device comprising the roll-shaped recording medium holding mechanism according to claim 1.   An image forming apparatus comprising: an image forming unit; and the roll sheet feeding device according to claim 6. An image forming apparatus comprising: an image forming unit; and the roll-shaped recording medium holding mechanism according to claim 1.