JP4593541B2 - Sheet roll holding mechanism, printing apparatus, and core tube - Google Patents

Description

  The present invention relates to a sheet roll holding mechanism that holds a core tube around which a sheet material is wound. The present invention also relates to a printing apparatus that includes a sheet roll holding mechanism and performs printing on, for example, printing paper and the core tube of the sheet roll.

  2. Description of the Related Art Conventionally, as a printing apparatus, for example, an apparatus that performs printing by thermally transferring ink of an ink ribbon onto printing paper by a print head is known. A printing apparatus using this type of ink ribbon includes an ink ribbon holding mechanism that rotatably holds a roll around which the ink ribbon is wound.

  A conventional ink ribbon holding mechanism includes a core tube holding wheel that holds one end of the core tube of the ink ribbon, a core tube driving wheel that holds and rotates the other end of the core tube, and one end of the core tube. And a compression coil spring that presses the core tube holding member.

  As shown in FIG. 8, the core tube holding wheel 116 included in the conventional ink ribbon holding mechanism is formed of a resin material, and includes a fitting portion 121 that is fitted into the inner peripheral portion of the core tube 115, and other core tubes 115. And a flange portion 122 against which an end face of the end portion is abutted. A shaft hole 125 is provided at the center of the fitting portion 121 of the core tube holding wheel 116, and a rotation shaft (not shown) is inserted into and supported by the shaft hole 125.

  By the way, since the core tube of the conventional ink ribbon is made of paper, the dimensional accuracy is poor, and the ink ribbon is not transported satisfactorily due to dimensional variations, and the print quality may be impaired.

For this reason, as the core tube holding wheel provided in the conventional sheet roll holding mechanism, a configuration in which an inclined surface that is fitted into the inner peripheral portion of the core tube is formed in the fitting portion is disclosed (for example, see Patent Document 1). . According to this core tube holding wheel, it is possible to prevent wrinkles and the like from being generated on the ink ribbon being conveyed due to variations in dimensional accuracy of the paper core tube.
JP 63-214466 A

  By the way, in the conventional ink ribbon holding mechanism described above, even when the both ends of the core tube of the ink ribbon are mounted in the opposite directions with respect to the core tube holding wheel and the core tube driving wheel, the core tube However, since the core tube is held across the wheels, the core tube may be erroneously mounted.

  If the orientation of both ends of the core tube of the ink ribbon is mistakenly installed, ink is not applied to the ink ribbon only on one side of the sheet material, and printing is not performed, or the ink that is conveyed There is a problem that the ribbon is loosened or the printing position on the printing paper is shifted.

  Further, the conventional ink ribbon holding mechanism has a relatively large space occupied by the thickness of the flange portion of the core tube holding wheel and the fitting portion protruding in the axial direction from one end portion of the core tube with respect to the axial direction of the core tube. Largely, when replacing the ink ribbon, the workability of attaching and detaching one end of the core tube to the core tube holding wheel was poor.

  Accordingly, an object of the present invention is to provide a sheet roll holding mechanism, a printing apparatus, and a core tube that can prevent erroneous mounting of both ends of the core tube and improve workability when the core tube is replaced. And

In order to achieve the above-described object, the sheet roll holding mechanism according to the present invention has a cylindrical shape in which a sheet material is wound on the outside and the inside is hollow, and has a constant outer diameter from one end to the other end . A core tube, a core tube holding member that abuts against one end of the core tube and holds the one end, a biasing member that presses the core tube holding member against one end of the core tube, and the other end of the core tube A core tube driving member that holds the portion and rotationally drives the core tube. In addition, the inner side of a position where the core tube enters from the one end portion toward the other end portion by a predetermined distance is pressed by the urging member by being configured so that the inner diameter dimension is smaller than that of the one end portion. An abutting portion capable of abutting the core tube holding member is provided. The core tube holding member is formed such that the maximum outer diameter dimension is smaller than the inner diameter dimension at one end portion of the core tube and larger than the inner diameter dimension of the abutting portion .

  According to the sheet roll holding mechanism according to the present invention configured as described above, when the orientation of both ends of the core tube is erroneously mounted in the opposite direction with respect to the core tube holding member and the core tube driving member, Since the abutting portion against which the inclined surface of the core tube holding member is abutted is not provided on the inner peripheral portion of the other end portion, the core tube holding member is not fitted into the inner peripheral portion of the other end portion of the core tube, and the core The other end portion of the core tube is not held by the tube holding member. Accordingly, erroneous mounting of the core tube is prevented, and the user can be surely recognized that the orientations of both ends of the core tube are opposite to the core tube holding member and the core tube driving member.

  Further, according to the sheet roll holding mechanism, the outer diameter of the core tube holding member is formed smaller than the inner diameter of the core tube, so that the end portion of the core tube is abutted against the core tube holding member as in the related art. Since there is not, the space occupied by this part is reduced. Accordingly, a relatively large space in the axial direction of the core tube on one end side of the core tube is ensured, and workability at the time of replacing the core tube is improved.

  Further, in the core tube holding member provided in the sheet roll holding mechanism according to the present invention, the inclined surface that is abutted against the abutting portion of the core tube is formed by gradually reducing the outer diameter, and the abutting portion of the core tube Preferably, an inclined surface that is abutted against the inclined surface of the core tube holding member is formed. As a result, the abutting portion of the core tube and the core tube holding member are in contact with each other at the inclined surfaces, so that the frictional force is increased, and the core tube and the core tube holding member are well rotated by being driven by the core tube driving member. Can work. Further, since the inclined surface is formed on the core tube holding member, the core tube can be reliably held without being affected by the dimensional accuracy of the inner diameter of the core tube.

  Further, the core tube driving member provided in the sheet roll holding mechanism according to the present invention is provided with a protrusion fitted into a groove provided at the other end of the core tube, the core tube is formed of a resin material, A plurality of grooves into which the projections of the core tube driving member are fitted are preferably formed in the other end portion in the circumferential direction. As a result, when the protrusion of the core tube driving member is fitted into the groove of the core tube, the angle of turning the core tube in the circumferential direction can be kept small, and the sheet material wound around the core tube is slackened. Is suppressed.

  Further, the core tube holding member provided in the sheet roll holding mechanism according to the present invention has a thickness parallel to the axial direction of the core tube from the end surface of one end portion of the core tube in a state of being abutted against the abutting portion of the core tube. It is preferable that it is formed so as not to protrude. As a result, when the one end portion of the core tube is attached to and detached from the core tube holding member, a larger space in the axial direction of the core tube on the one end portion side of the core tube is ensured. The property is further improved.

  A printing apparatus according to the present invention includes the above-described sheet roll holding mechanism of the present invention and a print head for printing on a sheet material.

Moreover, the core tube according to the present invention is a cylindrical core tube having a constant outer diameter from one end to the other end, in which a sheet material is wound outside and the inside is hollow .
Holds the core tube holding member abuts against one end of the core tube to retain the one end portion, a biasing member for pressing the core tube holding member with respect to the one end portion of the core tube, the other end portion of the core tube A core tube driving member that rotationally drives the core tube, and the core tube holding member has a maximum outer diameter dimension smaller than an inner diameter dimension at one end of the core tube, and is used for a sheet roll holding mechanism. A tube,
The inner side of the position entering the other end by a predetermined distance from the one end is configured so that the inner diameter is smaller than that of the one end, so that the core tube holding member pressed by the biasing member is pushed. An abutable abutting portion is provided , and this abutting portion is formed smaller than the maximum outer diameter dimension of the core tube holding member .

  As described above, according to the present invention, it is possible to prevent erroneous mounting of both ends of the core tube with respect to the core tube holding member and the core tube driving member, and to improve workability when replacing the core tube.

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

  The printing apparatus of the present embodiment performs printing by transferring the ink ribbon ink onto the printing paper supplied from the paper feed roll by the thermal transfer printing head, and prints labels to be attached to various articles. This is a so-called label printer.

  As shown in FIG. 1, the label printer 1 includes a printing unit 7 having a thermal transfer printing head 7 a that prints on a printing paper 5, a paper transport unit 8 that transports the printing paper 5 to the printing unit 7, and a printing unit 7. And a ribbon transport unit 9 for transporting the ink ribbon 6.

  The printing unit 7 includes a thermal transfer print head 7a and a platen 7b that supports the conveyed printing paper 5 at positions facing each other across the traveling path of the printing paper 5 and the ink ribbon 6.

  The paper transport unit 8 includes a paper feed roll 8a around which the print paper 5 is wound, a drive mechanism (not shown) that rotationally drives the paper feed roll 8a, and a travel path of the print paper 5 drawn from the paper feed roll 8a. And a guide roller 8b.

  The ribbon transport unit 9 includes a ribbon supply side roll 6a that supplies the ink ribbon 6 to the printing unit 7, a ribbon take-up side roll 6b that winds up the ink ribbon 6 supplied from the ribbon supply side roll 6a, and each of these rolls. An ink ribbon holding mechanism 12 serving as a sheet roll holding mechanism that holds each of 6a and 6b in a rotatable manner, and a plurality of guide rollers 13 constituting a travel path of the ink ribbon 6 are provided. The ink ribbon 6 is supported by a sheet material straddling a pair of ribbon supply side roll 6a and ribbon take-up side roll 6b, and ink is applied only to the outer peripheral surface of the sheet material.

  The ink ribbon holding mechanism 12 is provided corresponding to the ribbon supply side roll 6a and the ribbon winding side roll 6b of the ink ribbon 6, respectively. Each ink ribbon holding mechanism 12 includes a core tube holding wheel 16 as a core tube holding member that holds one end of the core tube 15 around which the ink ribbon is wound, and the core tube holding wheel 16 is used as an axis of the core tube 15. A compression coil spring 17 as an urging member that presses in the direction and a core tube driving wheel 18 that holds the other end of the core tube 15 and rotationally drives the core tube 15 are provided.

  The core tube 15 of the ink ribbon 6 held by the ink ribbon holding mechanism 12 is formed in a cylindrical shape by, for example, ABS (acrylonitrile, butadiene, styrene) resin or the like, and as shown in FIG. An abutting portion 21 against which the core tube holding wheel 16 is abutted is formed only in the one end portion side in the circumferential direction of the inner peripheral portion. Further, as shown in FIG. 3, an inclined surface 22 against which the outer peripheral portion of the core tube holding wheel 16 is abutted is directed from one end side to the other end side of the core tube 15. The inner diameter is gradually reduced. That is, the abutting portion 21 has a convex cross-sectional shape, and an inclined surface 22 is formed at a corner portion on the side that abuts against the outer peripheral surface of the core tube holding wheel 16. In the present embodiment, the abutting portion 21 is formed in a continuous ring shape that makes one round over the circumferential direction of the inner peripheral portion of the core tube 15, but is not limited to this shape, and as necessary. A plurality of discontinuous abutting portions may be formed, or an arcuate abutting portion may be formed only in a part of the inner peripheral portion in the circumferential direction.

  As shown in FIG. 4, the inclined surface 22 has an inclination angle θ with respect to the axial direction of the core tube 15 set to 45 degrees or less. When the inclination angle θ of the inclined surface 22 exceeds 45 degrees, a pressing force acts in a direction other than the axial direction of the core tube 15, and the holding state by the core tube holding wheel 16 is easily released, which is preferable. Absent. The inclination angle θ of the inclined surface 22 is preferably about 35 degrees, for example, and one end portion of the core tube 15 can be favorably held.

  Although not shown, one end of the core tube 15 is so-called chamfered at each edge on the outer peripheral side and the inner peripheral side, and the core tube holding wheel 16 is attached to the inner peripheral portion of the one end portion of the core tube 15. The operation of inserting and the operation of inserting one end of the core tube 15 into the space of the ink ribbon holding mechanism 12 in the label printer 1 are facilitated.

  Further, as shown in FIGS. 2A and 2B, a plurality of notch grooves 23 into which a later-described protrusion 33 of the core tube drive wheel 18 is fitted are provided in the other end portion of the core tube 15 in the circumferential direction. Are provided respectively. These notch grooves 23 are provided at positions divided into four equal parts in the circumferential direction of the core tube 15.

  As shown in FIG. 5, the core tube holding wheel 16 is formed by, for example, POM (polyoxymethylene) resin so that the outer diameter is smaller than the inner diameter of the core tube 15, and the inclined surface of the abutting portion 21 of the core tube 15. An inclined surface 24 abutted on the outer diameter 22 is formed by gradually reducing the outer diameter. That is, the core tube holding wheel 16 is formed in a so-called tapered shape in which an inclined surface 24 is formed on the outer peripheral portion.

  The inclined surface 24 of the core tube holding wheel 16 has an inclination angle θ with respect to the axial direction of the core tube 15 set to 45 degrees or less, similar to the inclined angle θ of the inclined surface 22 on the core tube 15 side described above. About 35 degrees is preferable.

  The core tube holding wheel 16 has one end portion of the core tube 15 in a state where the inclined surface 24 is pressed against the inclined surface 22 of the abutting portion 21 of the core tube 15 by the urging force of the compression coil spring 17 and is in surface contact. Hold.

  The core tube holding wheel 16 has a thickness parallel to the axial direction of the core tube 15 and protrudes from an end surface of one end portion of the core tube 15 in a state where the inclined surface 24 is abutted against the abutting portion 21 of the core tube 15. It is formed in a size that is not. Accordingly, when the one end portion of the core tube 15 is attached to and detached from the core tube holding wheel 16, a larger space on the one end portion side of the core tube 15 is ensured. Further improvement.

  Further, the core tube holding wheel 16 is provided with a shaft hole 26 at the center, and a rotation shaft 27 is inserted into the shaft hole 26 and supported. Further, the core tube holding wheel 16 is formed with a concave portion 28 with which one end of the compression coil spring 17 abuts. The core tube holding wheel 16 is driven as the core tube drive wheel 18 rotates and is rotated together with the core tube 15.

  As shown in FIGS. 6A and 6B, the core tube driving wheel 18 is formed of a resin material, and a fitting portion 31 that is fitted into the inner peripheral portion of the core tube 15, And a flange portion 32 against which the end face of the other end is abutted. The fitting portion 31 is provided with a protrusion 33 that is fitted into the notch groove 23 of the core tube 15 at one place in the circumferential direction.

  A shaft hole 35 is provided at the center of the fitting portion 31 of the core tube driving wheel 18, and the shaft hole 35 is inserted into and supported by a rotation shaft of a rotation drive mechanism (not shown). The core tube drive wheel 18 is rotationally driven by a rotational drive mechanism in a direction in which the ink ribbon 6 is conveyed from the supply side roll 6a to the take-up side roll 6b.

  In the present embodiment, the inclined surface 24 of the core tube holding wheel 16 is brought into surface contact with the inclined surface 22 of the abutting portion 21 of the core tube 15, but the abutting portion 21 of the core tube 15 is used. However, it is not limited to the configuration in which the inclined surface 22 is formed, and a configuration in which the projecting abutting portion is abutted against the inclined surface 24 of the core tube holding wheel 16 may be adopted although not shown.

  Further, if necessary, the surface of the inclined surface 24 of the core tube holding wheel 16 and the inclined surface 22 of the core tube 15 are appropriately subjected to surface treatment for increasing the surface roughness, thereby adjusting the magnitude of the frictional force. Thus, it is possible to prevent slippage between the abutted inclined surfaces 22 and 24 and to secure a better holding state.

  With respect to the ink ribbon holding mechanism 12 configured as described above, the operation of holding both ends of the core tube 15 of the ink ribbon will be described.

  First, one end portion of the core tube 15 of the ink ribbon is abutted against the core tube holding wheel 16 into the ink ribbon holding mechanism 12, and the core tube holding wheel 16 is pushed against the urging force of the compression coil spring 17. As shown in FIG. 7, the inclined surface 22 of the abutment portion 21 of the core tube 15 is abutted against the inclined surface 24 of the core tube holding wheel 16, so that one end portion of the core tube 15 is formed by the core tube holding wheel 16. Is retained.

  At this time, if the other end side of the core tube 15 is mistakenly attached to the core tube holding wheel 16, the inclined surface 24 of the core tube holding wheel 16 projects into the inner peripheral portion of the other end portion of the core tube 15. Since it is not applied, the other end portion of the core tube 15 is prevented from being held by the core tube holding wheel 16.

  Next, the end face of the other end portion of the core tube 15 is abutted against the flange portion 32 of the core tube drive wheel 18, and the four grooves of the core tube drive wheel 18 are inserted into the notch groove 23 of the other end portion of the core tube 15. By fitting any one of the protrusions 33, the other end portion of the core tube 15 is fixed and held on the core tube drive wheel 18. Thereby, both ends of the core tube 15 are held across the core tube holding wheel 16 and the core tube driving wheel 18 so as to be rotatable.

  In the present embodiment, four notch grooves 23 are provided at the other end portion of the core tube 15, so that when the protrusion 33 of the core tube drive wheel 18 is fitted into the notch groove 23 of the core tube 15, Since the angle at which the core tube 15 is rotated in the circumferential direction is suppressed to be small, it is possible to prevent the ink ribbon 6 wound around the core tube 15 from being slackened.

  Then, the supply side roll 6a of the ink ribbon 6 and the core tube 15 of the take-up side roll 6b are similarly attached to the respective ink ribbon holding mechanisms 12.

  As described above, according to the ink ribbon holding mechanism 12, the outer diameter dimension is smaller than the inner diameter dimension of the core tube 15, and the abutting portion 21 provided on the inner peripheral portion only on one end side of the core tube 15 is provided. The inclined surface 24 to be abutted is provided with the core tube holding wheel 16 formed by gradually reducing the outer diameter size, so that the core tube 15 and the core tube driving wheel 18 have the core tube 15. It is possible to prevent the both ends from being erroneously attached in the opposite direction. That is, according to the ink ribbon holding mechanism 12, when the both ends of the core tube 15 are erroneously attached to the core tube holding wheel 16 and the core tube driving wheel 18 in the opposite direction, the other end portion of the core tube 15. Since the abutting portion 21 against which the inclined surface 24 of the core tube holding wheel 16 is abutted is not provided on the inner peripheral portion of the core tube 15, the other end portion of the core tube 15 is prevented from being held by the core tube holding wheel 16. it can.

  Further, according to the ink ribbon holding mechanism 12, it is impossible to mount the paper core tube used in the conventional general ink ribbon, and the paper core tube with relatively poor dimensional accuracy is mounted. Can be prevented. Accordingly, since only the genuine ink ribbon 6 corresponding to the label printer 1 is attached to the ink ribbon holding mechanism 12, it is possible to maintain good print quality.

The core tube holding wheel 16 has a thickness parallel to the axial direction of the core tube 15 and protrudes from an end surface of one end portion of the core tube 15 in a state where the inclined surface 24 is abutted against the abutting portion 21 of the core tube 15. By being formed in such a size that is not performed, it becomes possible to ensure a relatively large space in the axial direction of the core tube 15 on one end side of the core tube 15 and improve workability when replacing the core tube 15. can do. Also,
The sheet roll holding mechanism according to the present invention is applied as an ink ribbon holding mechanism for holding the core tube of the ink ribbon. However, the sheet material is not limited to the ink ribbon as a sheet material. Of course, the present invention may be applied to a configuration for holding the core tube.

It is a schematic diagram which shows the label printer of this embodiment. It is a figure for demonstrating the core pipe of the supply side roll of an ink ribbon. It is sectional drawing which shows the one end part of a front core pipe. It is sectional drawing which expands and shows the principal part of the one end part of the said core pipe. It is sectional drawing for demonstrating the core pipe holding wheel of an ink ribbon holding mechanism. It is a figure for demonstrating the core pipe drive wheel of an ink ribbon holding mechanism. It is sectional drawing which shows the state by which the core pipe holding wheel was pressed by the one end part of the said core pipe. It is sectional drawing which shows the holding | maintenance state of the core pipe by the core pipe holding wheel which the conventional ink ribbon holding mechanism has.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Label printer 6 Ink ribbon 12 Ink ribbon holding mechanism 15 Core tube 16 Core tube holding wheel 17 Compression coil spring 18 Core tube drive wheel 21 Abutting part 22 Inclined surface 23 Notch groove 24 Inclined surface 33 Protrusion

Claims (9)

A cylindrical core tube having a constant outer diameter from one end to the other end, in which the sheet material is wound outside and the inside is hollow ,
Abuts on the one end of the core tube, a core tube holding member for holding the one end portion,
An urging member that presses the core tube holding member against the one end of the core tube;
While holding the other end of the core tube and a core tube drive member for rotationally driving the core tube,
The biasing member is configured such that the inner diameter of the core tube at a predetermined distance from the one end toward the other end is smaller than the one end. An abutting portion capable of abutting the core tube holding member pressed by is provided,
The core tube holding member is a sheet roll holding mechanism having a maximum outer diameter dimension smaller than an inner diameter dimension at the one end portion of the core tube and larger than an inner diameter dimension of the abutting portion . In the core tube holding member, an inclined surface that is abutted against the abutting portion of the core tube is formed by gradually reducing the outer diameter dimension,
The sheet roll holding mechanism according to claim 1 , wherein the abutting portion of the core tube is formed with an inclined surface that is abutted against the inclined surface of the core tube holding member. Wherein the core tube drive member, the projection is provided to be fitted in a groove provided in the other end of the core tube,
The core tube is formed of a resin material, the said other end of the core tube, the claims plurality of said grooves which the protrusion is fitted in the core tube drive member are formed circumferentially 1 or 2 A sheet roll holding mechanism according to claim 1. The core tube holding member, parallel thickness in the axial direction of the core tube, formed to have a size that does not protrude from the end surface of the one end of the core tube in a state of being abutted on the abutting portions of the core tube The sheet roll holding mechanism according to any one of claims 1 to 3 . The sheet roll holding mechanism according to any one of claims 1 to 4 , wherein the sheet material wound around the core tube is an ink ribbon. Printing apparatus comprising: a sheet roll holding mechanism according to any one of claims 1 to 5, and a print head for printing on the sheet material. In the cylindrical core tube having a constant outer diameter from one end to the other end , the sheet material is wound on the outside and the inside is hollow ,
A core tube holding member for holding the one end abuts against the one end of the core tube, and a biasing member for pressing the core tube holding member with respect to the one end of the core tube, the core tube while holding the other end portion and a core tube drive member for rotating the core tube, the core tube holding member is smaller is than the inner diameter of the one end portion of the maximum outer diameter dimension the core tube A core tube used in a sheet roll holding mechanism,
The core pressed by the urging member is configured such that the inside diameter of the position entering the other end portion from the one end portion by a predetermined distance is smaller than the one end portion. A core tube provided with an abutting portion capable of abutting the tube holding member , wherein the abutting portion is formed smaller than the maximum outer diameter dimension of the core tube holding member . In the core tube holding member, an inclined surface that is abutted against the abutting portion of the core tube is formed by gradually reducing the outer diameter dimension,
The core tube according to claim 7 , wherein the abutting portion is formed with an inclined surface that abuts against the inclined surface of the core tube holding member. Wherein the core tube drive member, the projection is provided to be fitted to the other end of the core tube,
The core tube is formed of a resin material, the other end of the core tube, the projections of the core tube drive member a plurality of said grooves claims are formed in the circumferential direction 7 or to be fitted 8 The core tube according to 1.

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