JP2011148580A - Paper supply mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology capable of easily carrying paper, by reducing a load of hindering carrying work of the paper, even if a driving source is stopped. <P>SOLUTION: This paper supply mechanism includes a motor 14, a flange unit 3, a flange driving gear 4, an idler unit 9 having an idler width narrow gear 10, and a flange torque limiter 17. The idler unit 9 selectively switches a state where the idler width narrow gear 10 is connected to the flange driving gear 4 and a state where the idler width narrow gear 10 is separated from the flange driving gear 4. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a paper supply mechanism for supplying paper.

  Conventionally, various techniques have been proposed for a paper supply mechanism that is provided in a printer or the like and supplies paper such as photographic paper. The paper supply mechanism has a plurality of operation modes related to the supply of photographic paper, and selectively switches the operation mode to be executed. Patent Document 1 describes a paper supply mechanism that selectively switches the operation mode to be executed by switching the gears to be connected.

Japanese Patent Application Laid-Open No. 2007-261085

  Now, among the plurality of operation modes, there is a mode in which the operator manually conveys the sheet. In this mode, since the drive source of the paper supply mechanism is stopped, the operator has to carry out the paper conveyance work while receiving a load, which makes manual conveyance work difficult.

  Accordingly, the present invention has been made in view of the above-described problems, and can reduce the load when carrying a paper and easily carry the paper even when the drive source is stopped. It aims at providing the technology that can be.

  A paper supply mechanism according to the present invention includes a drive source, a paper flange unit that supports a paper roll formed by winding paper in a roll shape, and rotates together with the paper roll. A flange drive gear for transmitting rotation between the drive shaft, an idler unit having a first idler gear meshable with the flange drive gear, and a torque limiter for transmitting a constant torque between the drive source and the first idler gear With. The idler unit selectively switches between a state in which the first idler gear meshes with the flange drive gear and a state in which the first idler gear is separated from the flange drive gear.

  According to the present invention, by separating the first idler gear from the flange drive gear, it is possible to reduce the load torque that hinders the rotation of the paper flange unit when the drive means is stopped. Therefore, the photographic paper can be easily conveyed.

FIG. 3 is a perspective view illustrating a configuration of a paper supply mechanism according to the embodiment. FIG. 3 is a perspective view illustrating a configuration of a paper supply mechanism according to the embodiment. It is a figure which shows the structure of the paper supply mechanism which concerns on embodiment. FIG. 3 is a perspective view illustrating a configuration of a paper supply mechanism according to the embodiment. FIG. 3 is a perspective view illustrating a configuration of a paper supply mechanism according to the embodiment. FIG. 3 is a perspective view illustrating a configuration of a paper supply mechanism according to the embodiment. FIG. 3 is a perspective view illustrating a configuration of a paper supply mechanism according to the embodiment. FIG. 3 is a perspective view illustrating a configuration of a paper supply mechanism according to the embodiment. FIG. 3 is a perspective view illustrating a configuration of a paper supply mechanism according to the embodiment. FIG. 3 is a perspective view illustrating a configuration of a paper supply mechanism according to the embodiment. FIG. 3 is a perspective view illustrating a configuration of a paper supply mechanism according to the embodiment.

<Embodiment 1>
The paper supply mechanism according to the embodiment of the present invention supplies paper such as photographic paper. In this embodiment, a paper supply mechanism is provided in a thermal transfer type color printer (hereinafter referred to as “printer” for short) that prints a color image on photographic paper using ink sheets having a plurality of different color panels. The description will be made assuming that it is provided.

  FIG. 1 is a perspective view showing the configuration of the paper supply mechanism. In the following description, the belt-shaped photographic paper 1 wound into a hollow roll is referred to as “paper roll 2”. As shown in FIG. 1, the paper supply mechanism includes a paper flange unit 3, a flange drive gear 4, and a bracket 23 that rotatably supports a plurality of gears including the flange drive gear 4. In the following drawings, instead of showing the gear teeth, a circle passing through the gear tips (hereinafter referred to as “tooth tip circle”) is shown.

  The paper flange unit 3 is a columnar member, and supports the paper roll 2 in a state of being inserted into the central cavity of the paper roll 2. A rotation shaft fixed to the printer is provided at the center of the cylinder of the paper flange unit 3, and can rotate around the rotation shaft integrally with the inserted paper roll 2. In the paper flange unit 3 in which the paper roll 2 is inserted, a portion that protrudes from the paper roll 2, that is, a flange, is provided with teeth that mesh with the flange drive gear 4.

  The flange drive gear 4 is composed of a gear 4a having a large diameter of the tip circle and a gear 4b having a small diameter of the tip circle. The gear 4a and the gear 4b are fixed to each other and integrated. The gear 4 a of the flange drive gear 4 is arranged in a state of always meshing with the paper flange unit 3, and transmits rotation to and from the paper flange unit 3.

  FIG. 2 shows a part of the paper supply mechanism that is not shown in order to facilitate understanding. As shown in FIG. 2, the paper supply mechanism includes a roller driving relay gear 5, a roller driving gear 6, a loading roller 7, a pinch roller 8, and a motor 14.

  The roller driving relay gear 5 and the flange driving gear 4 have the same rotation shaft, and are provided at different positions in the axial direction of the rotation shaft. Each of the flange driving gear 4 and the roller driving relay gear 5 is pivotally supported by a bracket 23 so as to rotate independently of each other. The roller driving relay gear 5 and the gear 4b of the flange driving gear 4 have the same diameter of the tip circle.

  The roller drive gear 6 is pivotally supported by a bracket 23 so as to rotate in a state of always meshing with the roller drive relay gear 5. The roller driving gear 6 transmits rotation to and from the roller driving relay gear 5. The loading roller 7 and the roller drive gear 6 have the same rotation shaft, and are provided at different positions in the axial direction of the rotation shaft. The loading roller 7 conveys the photographic paper 1 drawn from the paper roll 2. The paper supply mechanism according to the present embodiment is provided with a torque limiter (not shown) that transmits a constant torque between the roller driving gear 6 and the loading roller 7. Hereinafter, this torque limiter is referred to as a “roller torque limiter”. The roller torque limiter, like a general torque limiter, transmits a constant torque from one to the other, and gives a load torque to the other when one rotation is prohibited. Due to the function of this roller torque limiter, the roller drive gear 6 transmits a constant torque to and from the loading roller 7.

  The pinch roller 8 is crimped to the loading roller 7 via the photographic paper 1 by a crimping mechanism (not shown). The pinch roller 8 is rotatable and rotates according to the movement of the photographic paper 1.

  The motor 14 is a drive source for the paper supply mechanism, and can rotate in both forward and reverse directions. The motor 14 is supported by a bracket 23.

  FIG. 3 is a diagram illustrating a configuration of a printer around the paper supply mechanism. The printer according to the present embodiment is provided with a photographic paper insertion port 51, a leading edge detection means 52, a grip roller 53, and a printing unit (not shown).

  The photographic paper insertion port 51 is an insertion port into which the photographic paper 1 drawn from the paper roll 2 is inserted, and is provided in the vicinity of the paper roll 2 supported by the paper flange unit 3. The photographic paper 1 drawn out from the paper roll 2 passes through the photographic paper insertion port 51 and is supplied deeper than the photographic paper insertion port 51. Hereinafter, this direction is referred to as a “supply direction”. In the supply direction, a loading roller 7 and a pinch roller 8 are arranged after the photographic paper insertion port 51. The leading edge detection means 52 detects the leading edge of the photographic paper 1 and is provided immediately after the loading roller 7 and the pinch roller 8 in the feeding direction of the photographic paper 1. The grip roller 53 conveys the photographic paper 1 by a driving source different from the motor 14, and is provided after the leading edge detection means 52 in the supply direction of the photographic paper 1. A paper guide 54 for guiding the photographic paper 1 is provided from the photographic paper insertion port 51 to the grip roller 53. The printing unit prints the photographic paper 1 and is provided after the grip roller 53 in the supply direction of the photographic paper 1.

  Further, the printer is provided with a cover 55 for exposing and covering the paper flange unit 3. That is, in the present embodiment, the paper supply mechanism is provided in a printer having a cover 55 that covers the paper flange unit 3. The cover 55 is opened and closed when the paper roll 2 is replaced.

  FIG. 4 is a perspective view showing the idler unit 9 shown in FIG. 2 provided in the paper supply mechanism. The idler unit 9 has a state where torque can be transmitted at least between the flange drive gear 4 and an idler relay gear 13 which will be described later, and a state where torque cannot be transmitted (hereinafter also referred to as “idle state”). Selectively switch. The idler unit 9 includes an idler narrow gear 10, an idler wide gear 11 having a wider tooth width (tooth width in the rotation axis direction) than the idler narrow gear 10, and an idler gear shaft support portion 12 that supports these gears. It consists of and.

  The idler narrow gear 10 can mesh with the gear 4 b of the flange driving gear 4 without meshing with the roller driving relay gear 5. On the other hand, the idler wide gear 11 can simultaneously mesh with both the gear 4b of the flange drive gear 4 and the roller drive relay gear 5.

  The idler gear shaft support portion 12 includes a substantially triangular plate-like member 12a whose one side is curved inward, and a rotation shaft provided perpendicular to the plate-like member 12a at the position of the vertex facing the curved side. 12b. The idler gear shaft support portion 12 supports the idler narrow gear 10 and the idler wide gear 11 at the remaining two vertex positions.

  5 to 7 are diagrams showing a positional relationship among the flange driving gear 4, the roller driving relay gear 5, and the idler unit 9. FIG. The rotating shaft 12b of the idler unit 9 is mounted on the bracket so that the idler narrow gear 10 faces the flange drive gear 4 and the idler wide gear 11 faces both the flange drive gear 4 and the roller drive relay gear 5. 23.

  The idler unit 9 can be rotated within a certain range around the rotation shaft 12b.

  When the idler unit 9 is at one end of the rotatable range, the idler narrow gear 10 does not mesh with the roller driving relay gear 5 but meshes with the gear 4b of the flange driving gear 4 (FIG. 5). At this time, the idler wide gear 11 is disconnected from both the gear 4b of the flange driving gear 4 and the relay driving gear 5 for driving the roller.

  On the other hand, when the idler unit 9 is at the other end of the rotatable range, the idler wide gear 11 is in mesh with both the gear 4b of the flange drive gear 4 and the roller drive relay gear 5 (FIG. 6). At this time, the idler narrow gear 10 is disconnected from the gear 4b of the flange drive gear 4.

  When the idler unit 9 is between one end and the other end of the rotatable range, the idler narrow gear 10 is disconnected from the flange drive gear 4 and the idler wide gear 11 is relayed to the flange drive gear 4 and the roller drive. It will be in the state which can be separated from any of the gears 5 (FIG. 7). That is, in the state shown in FIG. 7, the idler narrow gear 10, the idler wide gear 11, the flange driving gear 4, and the roller driving relay gear 5 are separated from each other. Hereinafter, the state shown in FIG. 7 may be referred to as a “neutral state”. In the present embodiment, this neutral state and the above-described idle state are the same.

  The sheet supply mechanism can selectively switch the three states shown in FIGS. 5 to 7 by changing the position of the idler unit 9 in the rotation range as described above.

  As shown in FIGS. 5 to 7, the sheet supply mechanism includes an idler relay gear 13. The idler relay gear 13 rotates around the center axis 12 b of the idler unit 9. The idler relay gear 13 always meshes with both the idler narrow gear 10 and the idler wide gear 11. For example, when the idler relay gear 13 receives torque from the motor 14, the idler narrow gear 10 and the idler. The rotation is transmitted to the wide gear 11.

  Here, the idler wide gear 11 has a slightly increased load torque. That is, the idler wide gear 11 is somewhat difficult to rotate. Therefore, when the idler relay gear 13 rotates in response to the torque of the motor 14, the idler unit 9 rotates in the same direction as the rotation direction of the idler relay gear 13.

  Here, although the load torque of the idler wide gear 11 is somewhat large, the load torque of the idler narrow gear 10 may be somewhat large instead. Alternatively, the inner shaft of the through hole of the idler relay gear 13 may be rubbed by the central shaft 12 b so that the central shaft 12 b is rotated in the rotational direction of the idler relay gear 13. Even in these cases, when the idler relay gear 13 rotates upon receiving the torque of the motor 14, the idler unit 9 rotates in the same direction as the rotation direction of the idler relay gear 13.

  FIG. 8 is a perspective view showing a part of the configuration of the paper supply mechanism. As shown in the figure, the paper supply mechanism includes a worm 15, a worm wheel 16, and a flange torque limiter 17.

  The worm 15 is a screw gear, and is provided integrally with a rotating shaft that is rotated by the motor 14, and rotates around the rotating shaft. The worm wheel 16 is a helical gear and has the same rotation shaft as the idler relay gear 13 and is provided at different positions in the axial direction of the rotation shaft. The worm wheel 16 is also supported by a bracket 23 in the same manner as the idler relay gear 13.

  The worm wheel 16 is engaged with the worm 15 to form a worm gear. In the worm gear, like the general worm gear, when the worm 15 receives torque, both the worm 15 and the worm wheel 16 rotate. However, even if the worm wheel 16 receives torque, the worm 15 and the worm wheel 16 are rotated. Have a function called self-locking, in which none of them rotate.

  The flange torque limiter 17 is supported by the bracket 23 so that the center axis thereof is located on the same straight line as the rotation axes of the worm wheel 16 and the idler relay gear 13. The flange torque limiter 17 transmits a constant torque between the worm wheel 16 and the idler relay gear 13.

  Here, the worm wheel 16 is one of the gears connecting the motor 14 and the flange torque limiter 17, and the idler relay gear 13 is the gear connecting the flange torque limiter 17 and the idler narrow gear 10. The flange torque limiter 17 transmits a constant torque between the motor 14 and the idler narrow gear 10. Similarly, since the idler relay gear 13 is a gear that connects the flange torque limiter 17 and the idler wide gear 11, the flange torque limiter 17 transmits a constant torque between the motor 14 and the idler wide gear 11. It will be.

  The flange torque limiter 17 applies load torque to the other when rotation of one side is prohibited, as in the case of a general torque limiter. The flange torque limiter 17 is slightly less slippery than the roller torque limiter.

  FIG. 9 is a perspective view showing a part of the configuration of the paper supply mechanism. As shown in the figure, the sheet supply mechanism includes a relay connection gear 18 and a connection lever 19.

  The relay coupling gear 18 is a gear for meshing and coupling both the flange driving gear 4 and the roller driving relay gear 5 at the same time. One end of the connection lever 19 is provided with a relay connection gear 18, and the other end is provided with a cylindrical member 19 a extending in parallel with the rotation axis of the relay connection gear 18. The connecting lever 19 is passed through a cylindrical support shaft 23 a provided in the bracket 23 at the center thereof. Thereby, the connection lever 19 is hold | maintained at the bracket 23 so that it can rotate centering on the said spindle 23a. A part of the cylindrical member 19a is provided with a boss portion 19b protruding in the extending direction.

  When the connection lever 19 rotates about the support shaft 23a in the rotation direction A indicated by the arrow shown in FIG. 9, the relay connection gear 18 moves between the flange drive gear 4 and the roller drive relay gear 5. At the same time, the two mesh with each other (hereinafter referred to as “relay connection state”). On the other hand, when the connection lever 19 rotates from the state in the rotation direction B opposite to the rotation direction A indicated by the arrow shown in FIG. Is in a state of being simultaneously disconnected from the flange driving gear 4 and the roller driving relay gear 5 (hereinafter referred to as “relay disconnection state”). Thus, the connection lever 19 can selectively switch between the relay connection state and the relay disconnection state according to the direction of rotation about the support shaft 23a.

  10 and 11 are perspective views showing a part of the configuration of the paper supply mechanism. As shown in the drawing, the sheet supply mechanism includes a gear coupling spring 20 that is a first elastic body, a release lever 21, and a release spring 22 that is a second elastic body.

  The gear coupling spring 20 is a torsion spring and biases the cylindrical member 19 a of the coupling lever 19 in the rotation direction A. That is, the gear coupling spring 20 elastically biases the relay coupling gear 18 toward the flange driving gear 4 and the roller driving relay gear 5 via the coupling lever 19.

  The release lever 21 is a fan-shaped plate member, and is passed through the support shaft 23a of the bracket 23 with the vertex forming the central angle as the center. Accordingly, the release lever 21 is held by the bracket 23 so as to be rotatable about the support shaft 23a. On the release lever 21, a boss portion 21 a protruding from the opposite surface and engagement portions 21 b and 21 c are formed on the surface opposite to the surface facing the bracket 23.

  The release spring 22 is a torsion spring, a part of one end 22 a of the release spring 22 is engaged with the engagement portion 21 b of the release lever 21, and the portion beyond that is the boss portion of the connecting lever 19. It is in contact with 19b. On the other hand, the other end 22 b of the release spring 22 is engaged with the engagement portion 21 c of the release lever 21. The release lever 21 can elastically urge the connecting lever 19 in the rotation direction B by the release spring 22.

  The boss portion 21a of the release lever 21 is separated from the cover 55 when the cover 55 shown in FIG. 3 is open, and contacts the cover 55 when the cover 55 is closed. The portion of the cover 55 that contacts the boss portion 21a at this time is hereinafter referred to as a “cover contact portion”.

  FIG. 10 shows the state of the paper supply mechanism when the cover 55 is open. When the cover 55 is open, the relay connection gear 18 is elastically meshed with the flange drive gear 4 and the roller drive relay gear 5 by the biasing force of the gear connection spring 20. At this time, the gear coupling spring 20 urges the release spring 22 and the release lever 21 in the rotation direction A via the cylindrical member 19 a of the connection lever 19. As a result, the release spring 22 and the release lever 21 are held until the relay connection gear 18 is elastically engaged with the flange drive gear 4 and the roller drive relay gear 5 and the rotation of the connection lever 19 in the rotation direction A is stopped. Also rotate in the rotation direction A. Then, when the rotation of the connecting lever 19 in the rotation direction A stops, the rotation of the release spring 22 and the release lever 21 in the rotation direction A also stops.

  When the cover 55 changes from the open state (FIG. 10) to the closed state, the cover contact portion forcibly pushes the boss portion 21a of the release lever 21 mainly in the direction C. Then, the release lever 21 rotates in the rotation direction B, and the release spring 22 also rotates in the rotation direction B. At this time, the one end 22 a of the release spring 22 that rotates in the rotation direction B biases the boss portion 19 b of the connecting lever 19 in the rotation direction B.

  Here, the release spring 22 is formed of a material harder than the gear coupling spring 20, and has a spring constant stronger than that of the gear coupling spring 20. Therefore, when the release lever 21 rotates in the rotation direction B, the gear coupling spring 20 is more elastically deformed than the release spring 22. As a result, when the release lever 21 rotates in the rotation direction B, the boss portion 19b of the connection lever 19 rotates in the rotation direction B, and the gear connection spring 20 includes the flange drive gear 4 and the roller drive relay gear 5. Detached from.

  Next, the operation of each configuration described above will be described in detail. When the motor 14 is rotating, the worm 15, the worm wheel 16, and the idler relay gear 13 are rotated by the connection of the gears as described above. At this time, as described above, the idler unit 9 rotates in the same direction as the rotation direction of the idler relay gear 13.

  As shown in FIG. 5, when the motor 14 is driven and the idler relay gear 13 receives a constant torque from the flange torque limiter 17 and rotates in the direction R1, the idler unit 9 also rotates in the direction R1, and the idler width is narrow. The gear 10 meshes with the flange drive gear 4. In this state, when the idler relay gear 13 receives a constant torque and further rotates in the direction R1, the rotation is transmitted to the paper flange unit 3 via the idler narrow gear 10 and the flange drive gear 4. At this time, the paper flange unit 3 rotates in the direction R2 in which the photographic paper 1 is wound up, as shown in FIG.

  Conversely, as shown in FIG. 6, when the motor 14 is driven and the idler relay gear 13 receives a constant torque from the flange torque limiter 17 and rotates in the direction F1, the idler unit 9 rotates in the direction F1, The idler wide gear 11 meshes simultaneously with both the flange driving gear 4 and the roller driving relay gear 5. In this state, when the idler relay gear 13 receives a constant torque and further rotates in the direction F1, the rotation is transmitted to the paper flange unit 3 via the idler wide gear 11 and the flange drive gear 4. At this time, the paper flange unit 3 rotates in the direction F2 in which the photographic paper 1 is pulled out. Further, the torque received by the idler relay gear 13 is transmitted to the loading roller 7 through the idler wide gear 11, the roller driving relay gear 5 and the roller driving gear 6. At this time, the loading roller 7 rotates in the direction F <b> 3 in which the photographic paper 1 is supplied toward the grip roller 53.

  As described above, when the motor 14 continues to rotate in either the forward or reverse rotation direction, one of the idler narrow gear 10 and the idler wide gear 11 of the idler unit 9 meshes with the corresponding gear. It is in a state. In this state, when the motor 14 rotates in the reverse direction, the meshing between them is released and the neutral state is established. When the motor 14 is further rotated in the reverse direction, the other gear meshes with the corresponding gear and is connected. If the rotation of the motor 14 is stopped while the idler unit 9 is in the neutral state, the rotation of the idler unit 9 is stopped and the neutral state is maintained.

  Immediately after the idler unit 9 is in the neutral state, the cover 55 is closed. At this time, the roller driving relay gear 5 is disconnected from the idler wide gear 11, and the roller driving relay gear 5 is also disconnected from the relay connecting gear 18.

  At this time, when the cover 55 is opened from the closed state by the operator's work, the force mainly in the direction C shown in FIG. 10 is released, and accordingly, the release spring 22 is connected to the connecting lever. The force that presses 19 in the rotation direction B is released. On the other hand, since the gear coupling spring 20 urges the coupling lever 19 in the rotation direction A, the coupling lever 19 rotates in the rotation direction A, and the release lever 21 and the release spring 22 also rotate in the rotation direction. Rotate to A. When the release lever 21 rotates in the rotation direction A, the relay connection gear 18 provided integrally with the connection lever 19 meshes with the flange driving gear 4 and the roller driving relay gear 5.

  Here, even though the tooth tips collide between the relay coupling gear 18 and the flange driving gear 4 and the roller driving relay gear 5, the relay coupling gear 18 and the flange driving gear 4 and the roller are connected. If the gears are forced to move toward the driving relay gear 5 and the gears are engaged with each other, it is considered that the tooth tip is damaged. On the other hand, in the present embodiment, the relay coupling gear 18 is elastically pressed against the flange driving gear 4 and the roller driving relay gear 5 by the gear coupling spring 20. Therefore, even if the relay coupling gear 18 is not meshed with the flange driving gear 4 and the roller driving relay gear 5, the relay coupling gear 18 can be prevented from moving toward them. And if either gear rotates a little, these gears can mesh naturally. Therefore, it is possible to suppress the breakage of the tooth tips of these gears.

  When the relay connecting gear 18 meshes with the flange driving gear 4 and the roller driving relay gear 5 by the above-described operation, the paper flange unit 3 has the flange driving gear 4, the relay connecting gear 18, the roller driving relay gear 5, and the roller. It is connected to the loading roller 7 through the drive gear 6 in order. At this time, when the paper flange unit 3 is manually rotated in the supply direction of the photographic paper 1, the loading roller 7 is also rotated in the supply direction of the photographic paper 1 in conjunction with the rotation.

  When the cover 55 changes from the open state to the closed state, the cover contact portion forcibly pushes the boss portion 21a of the release lever 21 mainly in the direction C. Therefore, the release lever 21 rotates together with the release spring 22 in the rotation direction B, and the connecting lever 19 that contacts the release spring 22 also rotates in the rotation direction B. As a result, the relay connecting gear 18 provided integrally with the connecting lever 19 is disconnected from the flange driving gear 4 and the roller driving relay gear 5.

  As described above, the connection lever 19 selectively switches between the relay connection state and the relay disconnection state in conjunction with the opening / closing operation of the cover 55 in the printer.

  In the present embodiment, the turning of the connecting lever 19 in the turning direction B is stopped when the boss portion 19b of the connecting lever 19 contacts the side wall 23b of the bracket 23. Here, if the relative position between the cover 55 and the boss portion 21a of the release lever 21 is shifted to some extent by the assembly dimension or the component dimensions, the release lever 21 may rotate too far in the direction of the rotation direction B. is there. At this time, if the connecting lever 19 is forcibly rotated in the rotation direction B by a non-deformable member, not by the release spring 22, the connecting lever 19 or the like may be damaged. On the other hand, in the present embodiment, the release lever 21 rotates the connecting lever 19 via the release spring 22, and therefore the force for forcibly rotating the connecting lever 19 in the rotation direction B is applied by the release spring 22. Can be absorbed. Therefore, it can suppress that the connection lever 19 is damaged.

<Printer operation>
The above-mentioned printing unit provided after the grip roller 53 in the supply direction of the photographic paper 1 includes a thermal head (not shown) and a platen roller (not shown) provided so as to face each other. Yes. Hereinafter, main operation modes performed in the printer will be described.

  The printer according to the present embodiment uses the grip roller 53 as a preparatory operation before starting printing on the photographic paper 1 to position the front end of the photographic paper 1 between the thermal head and the platen roller (printing). (Position) is positioned downstream of the supply direction by a specified length.

  After this preparation operation is performed, the printer performs a printing operation. Specifically, the printer heats the thermal head while applying pressure by sandwiching the ink sheet and the photographic paper 1 between the thermal head and the platen roller, so that one color material of the ink sheet is printed on the photographic paper. 1 is attached. At the same time, the printer conveys the photographic paper 1 in the direction opposite to the supply direction (hereinafter referred to as “winding direction”). As a result, the printing paper 1 is printed with one color material. Hereinafter, the operation mode in which the printing operation is performed after the preparation operation is referred to as “printing mode”. Note that the paper roll 2 needs to be rotated with an appropriate torque when winding in the printing mode.

  The printer supplies the photographic paper 1 so that the front end of the photographic paper 1 is arranged at the same position as that immediately before the printing mode by rotating the grip roller 53 after the printing mode with one color material. To perform the operation. Hereinafter, this operation mode is referred to as “swing back mode”.

  The printer sequentially attaches the plurality of color materials of the ink sheet to the photographic paper 1 by alternately performing the printing mode and the swing back mode. As a result, color images, characters, and the like are printed on the photographic paper 1, and then cut into sheets and discharged from the printer. In the swing back mode, an appropriate brake torque (load torque) needs to be applied to the paper roll 2.

  When a number of printed photographic papers 1 are discharged from the printer, the photographic paper 1 on the paper roll 2 is reduced. In this case, the paper roll 2 supported in the printer is replaced with a new paper roll 2 by the following operation.

  First, the mechanism in the printer rotates the paper flange unit 3 to wind the photographic paper 1 around the paper roll 2 when a button operation is performed on the printer. This operation is performed until the leading edge of the photographic paper 1 located near the grip roller 53 reaches a position near the paper roll 2. Thereby, the paper roll 2 supported in the printer can be easily taken out. Hereinafter, this operation mode is referred to as “auto-unloading mode”. Thereafter, the operator opens the cover 55 and takes out the paper roll 2 supported in the printer from the printer.

  Next, the operator sets a new paper roll 2 in the printer and pulls out the photographic paper 1 from the paper roll 2. The operator passes the leading edge of the photographic paper 1 through the photographic paper insertion port 51, the loading roller 7 and the pinch roller 8 shown in FIG. 3 and then manually supplies the leading edge to the leading edge detecting means 52. . Hereinafter, this operation mode is referred to as “manual loading mode”. Thereafter, the operator closes the cover 55. Thus, the cover 55 is opened only when the manual loading mode is performed.

  After the above-described manual loading mode is performed, the mechanism unit in the printer moves the loading roller 7 so that the leading edge of the photographic paper 1 reaches the grip roller 53 after the leading edge detecting means 52 in the supply direction. The photographic paper 1 is supplied by rotating. Hereinafter, this operation mode is referred to as an “auto loading mode”.

<Operation of paper supply mechanism>
Next, the operation relating to the paper supply mechanism in each mode will be specifically described. First, the print mode will be described. In this printing mode, the grip roller 53 conveys the printing paper 1 in the winding direction. At the same time, the idler relay gear 13 receives the torque of the motor 14 and rotates in the direction R1. Therefore, the paper flange unit 3 rotates in the direction R2 (FIG. 1). As a result, the photographic paper 1 from the grip roller 53 is wound around the paper roll 2. The torque at the time of winding is a constant torque by the flange torque limiter 17. Thus, in the printing mode, the paper roll 2 is rotated with an appropriate torque.

  In the printing mode, since the idler relay gear 13 rotates in the direction R1, the roller driving relay gear 5 is not connected to either the idler narrow gear 10 or the idler wide gear 11 (FIG. 4). In the printing mode, since the cover 55 is closed, the roller driving relay gear 5 is not connected to the relay connecting gear 18. That is, in the printing mode, the roller driving relay gear 5 is not connected to any of the idler narrow gear 10, the idler wide gear 11, and the relay connecting gear 18. Therefore, in the printing mode, the roller driving relay gear 5 can freely rotate, so that the roller torque limiter does not function. Therefore, since the loading roller 7 is merely rotated along with the photographic paper 1, the influence of the loading roller 7 on the conveyance of the photographic paper 1 is suppressed in the printing mode.

  Next, the swing back mode will be described. In the swing back mode, the rotation of the motor 14 is stopped in the printing mode. Since the swing back mode is performed after the printing mode, when the motor 14 is stopped, the connection of each gear is kept the same as the connection in the printing mode.

  In the swing back mode, the grip roller 53 transports the photographic paper 1 in the transport direction opposite to that in the print mode, that is, in the supply direction of the photographic paper 1. As a result, the photographic paper 1 is pulled out from the paper roll 2 by the grip roller 53, and the paper flange unit 3 rotates in the direction F2 opposite to the direction R2.

  Here, even if the paper flange unit 3 rotates, the meshing between the idler narrow gear 10 and the flange driving gear 4 of the idler unit 9 is not disengaged from the balance of force. Therefore, the rotation of the paper flange unit 3 is transmitted to the worm wheel 16 shown in FIG. 6 through the connection of each gear, but the rotation of the worm wheel 16 is prohibited by self-locking. Therefore, the idler relay gear 13 rotates in a state where the rotation of the worm wheel 16 is prohibited. At this time, the flange torque limiter 17 applies a constant load torque to the idler relay gear 13. If it does so, a fixed load torque will be given to the paper flange unit 3 from the idler relay gear 13 through the connection of each gear. As a result, when the photographic paper 1 is conveyed from the paper supply mechanism toward the printing unit by the grip roller 53, a certain range of tension is applied to the photographic paper 1. Thus, an appropriate brake torque (load torque) is applied to the paper roll 2 in the swing back mode.

  In the swing back mode, as in the printing mode, the roller driving relay gear 5 is not connected to any of the idler narrow gear 10, the idler wide gear 11, and the relay connecting gear 18. Therefore, in the swing back mode, the loading roller 7 is only rotated along with the photographic paper 1, and thus the influence of the loading roller 7 on the conveyance of the photographic paper 1 is suppressed.

  Next, the auto unloading mode will be described. In this auto-unloading mode, as in the printing mode, the idler relay gear 13 receives the torque of the motor 14 and rotates in the direction R1, and the paper flange unit 3 rotates in the direction R2. As a result, the photographic paper 1 from the grip roller 53 is wound around the paper roll 2.

  In the auto-unloading mode, as in the printing mode, the roller driving relay gear 5 is not connected to any of the idler narrow gear 10, the idler wide gear 11, and the relay connecting gear 18. Therefore, in the auto-unloading mode, the loading roller 7 is only rotated along with the photographic paper 1, so that the influence of the loading roller 7 on the conveyance of the photographic paper 1 is suppressed.

  Next, the manual loading mode performed after the auto unloading mode will be described. In the manual loading mode, first, the idler unit 9 is in a neutral state by driving the motor 14.

  Thereafter, the following work is performed by the worker. First, the cover 55 is opened by the operator. Thereby, the relay connection gear 18 meshes simultaneously with both the flange drive gear 4 and the roller drive relay gear 5, and the paper flange unit 3 and the loading roller 7 are connected to each other.

  Thereafter, the operator replaces the paper roll 2 supported in the printer with a new paper roll 2, and inserts the leading end of the photographic paper 1 drawn out from the new paper roll 2 into the photographic paper insertion slot 51. . Since the photographic paper 1 is wound in a roll shape, this operation is performed while pulling out the photographic paper 1 from the paper roll 2. At this time, the idler unit 9 is in a neutral state, and since the flange torque limiter 17 is not included in the connection from the paper flange unit 3 to the loading roller 7, the idler unit 9 rotates with a light force without being subjected to the load of the flange torque limiter 17. Can be made.

  When the paper flange unit 3 is rotated after inserting the leading end of the photographic paper 1 into the photographic paper insertion slot 51, the photographic paper 1 inserted into the photographic paper insertion slot 51 is pushed further into the back. Since the loading roller 7 rotates in conjunction with the rotation of the paper flange unit 3 by the above-described gear connection, the operation of sandwiching the leading edge of the photographic paper 1 between the loading roller 7 and the pinch roller 8 and the photographic paper 1 Furthermore, the operation | work conveyed to the back can be simplified.

  Here, the feeding amount of the photographic paper 1 by the loading roller 7 is larger than the feeding amount of the photographic paper 1 by the paper flange unit 3. Therefore, after the photographic paper 1 is sandwiched between the loading rollers 7, the photographic paper 1 between the loading roller 7 and the paper flange unit 3 is pulled by these. At this time, the roller torque limiter works so that the loading roller 7 does not pull the photographic paper 1 too much. Therefore, in the manual loading mode, the photographic paper 1 is prevented from being loosened or torn.

  After that, when the leading edge of the photographic paper 1 reaches the leading edge detection means, and the leading edge detection means detects the leading edge, the printer causes the notification means (not shown) to complete the manual conveyance of the photographic paper 1 by the operator. Notify Then, the worker finishes the work and closes the cover 55.

  Next, the auto loading mode performed by the mechanism unit in the printer after the manual loading mode will be described. In this autoloading mode, the cover 55 is closed, so that the roller driving relay gear 5 is not connected to the relay connecting gear 18.

  In this mode, the idler relay gear 13 receives the torque of the motor 14 and rotates in the direction F1. Therefore, the paper flange unit 3 rotates in the direction F2, and the loading roller 7 rotates in the direction F3 (FIG. 1). As a result, the leading edge of the photographic paper 1 is conveyed to the grip roller 53. Thereafter, the photographic paper 1 is precisely conveyed by the grip roller 53 to prepare for printing.

  In this auto loading mode, as in the manual loading mode, the feed amount of the photographic paper 1 by the loading roller 7 is larger than the feed amount of the photographic paper 1 by the paper flange unit 3. Since the roller torque limiter works so that the loading roller 7 does not pull the photographic paper 1 too much, the photographic paper 1 is prevented from being loosened or torn.

  According to the paper supply mechanism according to this embodiment as described above, the rotation of the paper flange unit 3 is prevented when the motor 14 is stopped by separating the idler narrow gear 10 and the idler wide gear 11 from the flange drive gear 4. The load torque can be reduced. Therefore, the photographic paper 1 can be easily conveyed in the manual loading mode.

  Further, according to the paper supply mechanism according to the present embodiment, the loading roller 7 can be operated as necessary. In particular, the loading roller 7 applies driving torque in the manual loading mode and the auto loading mode, but only rotates in other modes, so that the life of the roller torque limiter is extended. In other words, an inexpensive torque limiter can be used as the roller torque limiter.

  Further, when the cover 55 is opened and closed, the connecting lever 19 is switched in conjunction with the opening and closing operation, so that it is not necessary to perform a special switching operation on the connecting lever 19, which is efficient.

  Moreover, in order to realize the above-described multiple types of operation modes, for example, an expensive member such as a one-way clutch is apt to be used or a complicated mechanism is apt to be used. The mechanism can be realized with few and inexpensive parts. Therefore, assembly becomes easy and it can be manufactured at low cost.

  1 photographic paper, 2 paper rolls, 3 paper flange unit, 4 flange drive gear, 5 roller drive relay gear, 7 loading roller, 9 idler unit, 10 idler narrow gear, 11 idler wide gear, 14 motor, 17 flange torque Limiter, 18 relay connection gear, 19 connection lever, 20 gear connection spring, 21 release lever, 22 release spring, 55 cover.

Claims (5)

A driving source;
A paper flange unit that supports a paper roll formed by winding paper in a roll and rotates integrally with the paper roll;
A flange drive gear that transmits rotation to and from the paper flange unit;
An idler unit having a first idler gear meshable with the flange drive gear;
A torque limiter for transmitting a constant torque between the drive source and the first idler gear;
The idler unit is a paper supply mechanism that selectively switches between a state in which the first idler gear meshes with the flange drive gear and a state in which the first idler gear is separated from the flange drive gear. The paper supply mechanism according to claim 1,
A loading roller for conveying the paper drawn from the paper roll;
A roller driving relay gear having the same rotational axis as the flange driving gear and transmitting rotation to and from the loading roller;
The idler unit is
A second idler gear capable of meshing simultaneously with the flange driving gear and the roller driving relay gear, wherein the first idler gear meshes with the flange driving gear; and the second idler gear is the flange driving gear. And the state of meshing simultaneously with the roller driving relay gear, and the first idler gear, the second idler gear, the flange driving gear and the roller driving relay gear are selectively switched,
The torque limiter is
A paper supply mechanism that transmits a constant torque between the drive source and the second idler gear. The paper supply mechanism according to claim 2,
A relay coupling gear that can mesh simultaneously with the flange driving gear and the roller driving relay gear;
A relay coupling state in which the relay coupling gear meshes simultaneously with the flange driving gear and the roller driving relay gear; and a relay disconnecting state in which the relay coupling gear is simultaneously disconnected from the flange driving gear and the roller driving relay gear. A connection lever for selectively switching;
A first elastic body that elastically biases the relay connection gear toward the flange drive gear and the roller drive relay gear when the connection lever switches from the relay disconnection state to the relay connection state; A paper supply mechanism further provided. The paper supply mechanism according to claim 3,
The paper supply mechanism is provided in a printer having a cover that covers the paper flange unit,
The connection lever is a paper supply mechanism that selectively switches between the relay connection state and the relay disconnection state in conjunction with opening and closing operations of the cover in the printer. The sheet supply mechanism according to claim 3 or 4, wherein:
The connection lever is rotatable around a predetermined rotation axis, and is switched from the relay connection state to the relay disconnection state according to a predetermined rotation direction,
A second elastic body;
A paper supply mechanism further comprising: a release lever capable of elastically urging the connecting lever in the predetermined rotation direction by the second elastic body.

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