JPH08104042A - Printer - Google Patents

Abstract

PURPOSE: To provide a printer, in which no loosening of ribbon occurs at the change of ink ribbon cassettes and no waste of unused portion of ribbon in produced. CONSTITUTION: Three gears are fixed fast by competing their rotating directions with one another by engaging an interrupting gear 43 energized with a tension spring 44 just below the engaging part of a driving transmission gear 39 with an unwinding gear 40. The sliding frictional resistance developed between the fixed unwinding gear 40 and a sliding clutch 40 is applied through a feed-back shaft 53 to a delivery side core 21-2 so as to properly brake the delivery side core 21-2, which delivers ink ribbon 28 in company with the winding-up of a wind-up side core 21-1. When a printing head 26 is lifted by rotatingly driving a fulcrum shaft 33 with a head lifting mechanism Mc or 35, the rotation of the fulcrum shaft 33 is transmitted through an axially fixed gear 37, a gear shaft 58 and a sliding clutch 38 to the driving transmission gear 39, resulting for the driving transmission gear 39 in pushing the interrupting gear 43 downwards so as to disengage the interrupting engagement and drive the unwinding gear 40 in order to unwind the unused portion of the ink ribbon 28 and consequently solve the loosening problem of the ink ribbon.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing apparatus that transfers ink from an ink ribbon onto a sheet for printing.

[0002]

2. Description of the Related Art Conventionally, a printing apparatus has been put into practical use which prints by thermally transferring the ink of an ink ribbon onto a sheet based on the thermal control of a print head. A dedicated ink ribbon is used for such a printing device.

FIG. 9 (a) is a perspective view showing an ink ribbon cassette accommodating such an ink ribbon and a frame side surface of a printing apparatus in which the ink ribbon cassette is mounted. Further, FIG. 2B shows a front view thereof, and FIG. 1C shows a sectional view taken along the line AA 'of FIG.

As shown in FIG. 1 (a), the ink ribbon cassette 1 can be inserted into and removed from the printer in a direction from the lower left to the upper right indicated by an arrow B in a cassette insertion opening 3 provided on a frame side surface 2 of the printer. Be attached to. In the central portion of the upper surface of the ink ribbon cassette 1, a print head inlet / outlet hole 6 (see FIG. 1A) is provided on almost the entire surface. And
In the ink ribbon cassette 1, an unused portion 5-1 of the ink ribbon 5 is wound around and held by a delivery side core 4-1 of the ink ribbon cassette 1 as shown in FIG. The used portion 5-2 of the ink ribbon 5 is wound around and retained on the core 4-2. If the ink ribbon 5 is a ribbon used only for black printing,
Black ink is applied to the entire surface. On the other hand, in the case of a ribbon used for color printing, for example, the three primary colors of subtractive colors, yellow, magenta, and cyan are usually repeatedly applied in the above order in the longitudinal direction of the ink ribbon 5 in a frame-sequential manner. The size of the coating surface of these one color is
For example, the size is substantially corresponding to the printing surface of image receiving paper such as B6 size and A6 size.

On the other hand, the cassette insertion opening 3 has a minimum necessary opening for preventing danger so that the user will not accidentally inadvertently insert his / her hand or the like into the apparatus when the ink ribbon cassette 1 is not installed. Therefore, a wide upward protruding portion 3-1 is provided below the opening, whereby the cassette insertion opening 3 is formed in a so-called downward "U" shape.

FIG. 10A shows a state in which the ink ribbon cassette 1 is mounted in the cassette insertion opening 3 together with the main part of the printing apparatus. This figure is a view seen from the inside of the frame side surface 2 (inside of the printing device), and shows the ink ribbon cassette 1 as it is as seen from the arrow AA 'in FIG. 9C. FIG. 10 (a) above is shown in FIG. 9 (a), (b),
The same components as those in (c) are shown with the same numbers as in FIG. 9 (the same applies to the following drawings). As shown in FIG. 10 (a), at the beginning of mounting, the ink ribbon 5 in the ink ribbon cassette 1 has the delivery side core 4-
1 and the winding side core 4-2, the wound portion 5-3.
It is held without slack as shown in. Inside the printing apparatus, a platen 8 and a paper transport roll pair 9 are arranged below the ink ribbon cassette, and above the ink ribbon cassette 1, a print head 12 is held at one end of a head elevating member 11 and a print head 12 is located at a reference position. ing. The reference position of the print head 12 is a stop position in the initial stage, maintenance work, ink ribbon replacement, and the like. The head raising / lowering member 11 has the other end rotatably supported by a support shaft 13, and when printing, the support shaft 13 is moved from the state shown in the drawing.
Rotate in the clockwise direction shown by arrow C in the figure,
As a result, the print head 12 descends obliquely downward as indicated by arrow C in the figure.

FIG. 1B is a diagram showing the state of the ink ribbon 5 during printing. As shown in FIG. 2B, the lowered print head 12 is attached to the ink ribbon cassette 1.
Further descending in the print head inlet / outlet hole 6 and the ink ribbon 5 and the image receiving paper (paper) 14 carried in under the ink ribbon 5 are pressed against the platen 8 to form a printing portion,
A heating element (not shown) corresponding to the print dots is caused to generate heat, and the thermal energy causes the ink of the ink ribbon 5 to be transferred to the image receiving paper 1.
Transfer to 4. Platen 8 according to the print timing
Rotates in the clockwise direction indicated by arrow D in the figure, and in synchronization with this rotation, the pair of paper transport rolls 9 rotates to carry out the printed portion of the image receiving paper 14 in the leftward direction indicated by arrow E in the figure. On the other hand, on the other hand, the winding side core 4-2 rotates in the clockwise direction shown by the arrow F in the drawing to wind up the used portion of the ink ribbon 5, and the winding side core 4 is driven by this winding.
1 rotates in the clockwise direction indicated by arrow G in the figure, and the unused portion 5-1 of the ink ribbon 5 is sent out and supplied to the printing section. If there are wrinkles in the ink ribbon 5 between the print head 12 and the delivery side core 4-1, the transfer of the ink to the image receiving paper 14 will be hindered. Therefore, in general, in order to prevent the occurrence of such wrinkles, the sending side core 4-
A certain amount of braking is applied to the rotation of No. 1 to give a predetermined tension T to the ink ribbon 5 between the print head 12 and the sending side core 4-1.

By the way, the above-mentioned print head 12 is used when the printing is temporarily stopped or the image receiving paper 14 is idly fed.
In order to release the contact of the ink ribbon 5 with the image receiving paper 14,
It stops at an intermediate position between the print position and the reference position, which is located slightly above the platen 8. Also, even after printing is completed,
Similarly, in order to prevent the platen 8 from being deformed over time due to the pressure contact, the platen 8 is stopped at the intermediate position.

FIG. 11A shows such a print head 12
FIG. 3 is a diagram showing a state in which the ink ribbon 5 is stopped at an intermediate position and a state of the ink ribbon 5 at this time. As shown in the figure, the print head 12 moves upward from the platen 8, and
It is also separated from the ink ribbon 5. On the other hand, the ink ribbon 5 remains in a slackened state by contacting with the platen 8 or the image receiving paper 14 due to its own weight even after the pressure contact with the platen 8 by the print head 12 is released. Has been maintained.

By the way, although there is no problem in printing again as it is, for example, when the ink ribbon 5 of the ink ribbon cassette 1 is completely used up, or by switching from black printing to color printing, the ink ribbon cassette 1
When replacing the print head 12, the head elevating member 11 is rotated counterclockwise as indicated by an arrow H in the drawing so as not to interfere with the removal / insertion of the ink ribbon cassette 1.
Is further raised from the state shown in the figure to the reference position.

In FIG. 1B, the ink ribbon cassette 1 is replaced while the ink ribbon 5 is being used.
2 has shown the state which rose to the reference position.

[0012]

However, as is apparent from the figure, if the ink ribbon cassette 1 is pulled out for replacement (to the side opposite to the figure), the delivery side core 4-1 and the take-up core 4-1 are wound. The slack portion 5-4 of the ink ribbon 5 between the side cores 4-2 is the protrusion 3-1 of the cassette insertion port 3.
And the slack portion 5-4 is damaged, or in the extreme case, the unused portion of the ink ribbon 5-1 is cut.

Therefore, in order to eliminate the occurrence of such an obstacle, the slack of the slack portion 5-4 of the ink ribbon 5 must be eliminated. However, the above print head 1
When the ink ribbon 5 is simply raised in the same manner as the ribbon feeding in the normal printing, the platen 8 and the feeding-side core 4 are wound when the ribbon is wound in the used ribbon winding direction shown by an arrow K in the figure.
The unused portion 5-4 between -1 is also wound while being wound in the winding core 4-2 direction. Originally, the winding side core 4-2 is in the forward direction (winding direction) in this way.
When the ink ribbon cassette is once taken out and reattached, the slack part wound in the direction of the winding side core 4-2 is fed back to the platen 8 and the print head again. It does not move upstream from the contact portion (printing portion) with 12. Therefore, when the ink ribbon 5 is used next time, as the print head 12 descends, an unused portion corresponding to the length wound in the direction of the winding side core 4-2 is supplied to the sending side core 4. -1 will be newly transmitted.

When the unused portion is wound around the winding-side core 4-2 and cannot be reused each time the temporary insertion and removal are performed as described above, the printing surface of the image-receiving paper is particularly dealt with. In the case of a color ink ribbon that is sequentially coated with one set of three primary colors in a size that corresponds to the above, the size of the coating surface of the remaining unused portion of the color ink of which the use is temporarily interrupted is the same as described above. There is a problem in that it is smaller by the amount taken up by the take-up side core 4-2 side and does not correspond to the size of the remaining unprinted portion of the image receiving paper.

Not only that, but in the case of one set of three primary colors of color ink, if one color such as yellow becomes unusable as described above, a new set of three primary colors of yellow is applied next. Therefore, in the worst case, the other two colors of magenta and cyan following yellow, which cannot be used in the middle of the above process, are unused and cannot be used. There was a problem. Further, not only the color ink ribbon but also the black ink ribbon, the ink ribbon used in such a printing apparatus is extremely expensive. Therefore, the unused portion is replaced by the unused portion every time the ink ribbon is replaced. Even if the waste of being taken up by the user is slightly visible, if it is accumulated, it will be a great waste and the user will be greatly dissatisfied.

In view of the above conventional circumstances, the object of the present invention is to
(EN) Provided is a printing apparatus in which the ink ribbon cassette can be immediately removed from the printing apparatus without loosening the ribbon when the ink ribbon cassette is exchanged, and the ink can be used from the unused portion of the previous ink in the next printing without waste of the unused portion of the ribbon.

[0017]

The structure of the ink ribbon according to the present invention will be described below. The present invention is at least
A platen, a print head that can be brought into contact with and separated from the platen, an ink ribbon onto which ink is transferred to a sheet by pressure contact with the platen by the print head, and a drive unit that conveys the ink ribbon in the printing sub-scanning direction It is premised on a printing apparatus having a driven shaft which winds and holds an unused portion of the ink ribbon and is driven in a predetermined direction by the conveyance of the ink ribbon by the driving of the driving means.

According to a first aspect of the present invention, there is provided a printing apparatus in which a braking means for applying a braking force to the driven shaft, a braking enabling means for enabling the braking operation of the braking means, and the print head for the platen. The pressure contact releasing means for releasing from the pressure contact, and the control operation of the braking means validated by the brake enabling means in association with the release operation of the pressure contact releasing means are invalidated and the driven shaft is rotated in the direction opposite to the predetermined direction. And a control means.

According to a second aspect of the present invention, in the printing clutch, the sliding clutch for applying a braking force to the driven shaft by the sliding friction resistance and the gear on the other side on which the sliding clutch makes sliding friction are fixed. An interrupting gear that enables the braking operation of the print head, and a head lifting mechanism that releases the print head from pressure contact with the platen by rotationally driving a support shaft of a lift member that lifts the print head, and pressure contact by the head lift mechanism. By transmitting the rotational drive from the head elevating mechanism along with the release operation to release the interrupt of the interrupt gear, the interrupt clutch control operation enabled by the interrupt gear is invalidated, and the slip clutch causes sliding friction. By transmitting the rotational drive from the head elevating mechanism to the gear on the other side, the driven shaft is moved to the ribbon via the slip clutch. The exit direction configured and a drive transmission gear is rotated in the unwinding direction is the reverse direction.

[0020]

In the printer according to the first aspect of the present invention, the braking means applies the braking force to the driven shaft, and the braking enabling means makes the braking operation effective. The pressure contact releasing means releases the print head from the pressure contact with the platen, and in response to the releasing operation, the control means invalidates the control operation of the braking means enabled by the brake enabling means and reverses the driven shaft from the predetermined direction. Rotate in the direction.

In the printer according to the second aspect of the present invention, the interrupting gear is fixed to the sliding clutch and the gear on the other side that performs sliding friction, and is applied to the driven shaft from the sliding clutch by the sliding friction resistance. Enable the braking action of the braking force. The head elevating mechanism releases the print head from the pressure contact with the platen by rotationally driving the support shaft of the elevating member for elevating the print head. With this release operation,
The drive transmission gear transmits the rotational drive from the head elevating mechanism to the interruption gear to cancel the interruption to invalidate the control operation of the slip clutch, and to the gear on the other side on which the slip clutch causes sliding friction. By transmitting the rotational drive from the head elevating mechanism, the driven shaft is rotated through the slip clutch in the rewinding direction which is the opposite direction to the ribbon feeding direction.

As a result, when the ink ribbon cassette is replaced, the ribbon is not loosened, and therefore the ink ribbon cassette can be immediately removed from the printing apparatus, and can be used from the previously unused portion of the ink in the next printing. There is no waste in the unused parts of.

[0023]

Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a side sectional view schematically showing the configuration of the main part of the printing apparatus according to the embodiment. This figure shows a state in which an ink ribbon cassette 21 similar to the conventional one is inserted into the inside (from the side opposite to the drawing to the front) of the frame side 22 of the printing apparatus into the inside (from the side opposite to the drawing) and attached to the printing apparatus. In the drawing, the ink ribbon cassette 2 is in a state during printing and is held at one end of the head lifting arm 24.
The print head 26 descending in the head entry / exit hole 25 of No. 1
, But contact the platen 27 to form a printing portion. In this state, the print head 26 presses the ink ribbon 28 and the image receiving paper 29 against the platen 27, and the ink of the ink ribbon 28 is transferred to the image receiving paper 29 by the heat generated by a heating element (not shown) to perform printing.

The platen 2 is synchronized with this print timing.
7 is configured to rotate in the clockwise direction indicated by arrow a in the figure. In synchronization with this rotation, the paper transport roll pair 30 is rotationally driven by the paper feed mechanism Ma (31) to carry out the printed portion of the image receiving paper 29 in the leftward direction indicated by the arrow b in the drawing, and further, the winding side core 21. -1 is a ribbon feeding mechanism Mb (3
2) and is rotated in the clockwise direction indicated by the arrow c in the figure to wind up the used portion 28-1 of the ink ribbon 28. Further, following this winding, the sending-out side core 21-2 rotates in the clockwise direction indicated by the arrow d in the figure, sending out the unused portion 28-2 of the ink ribbon 28 and supplying it to the printing section. . To the driven rotation of the delivery side core 21-2, an appropriate amount of braking, which will be described in detail later, is applied, whereby a predetermined tension is applied to the ink ribbon 28 between the delivery side core 21-2 and the print head 26. T is given and stretched so that there is no slack.

A wide upward projection portion 23-1 is provided below the opening of the cassette insertion opening 23, and a downward "U" shape is formed to match the shape of the insertion portion of the ink ribbon cassette 21. There is.

The head lifting arm 24 holding the print head 26 at one end is rotatably supported at the other end by a support shaft 33. The support shaft 33 has a head lifting mechanism M.
It is rotationally driven in both forward and reverse directions by c (35). A lifting mechanism gear 36 is fixed to the tip of the support shaft 33,
The elevating mechanism gear 36 will be described in detail later, but a drive transmission gear 39 through a shaft fixed gear 37 and a slip clutch 38.
Drive. The drive transmission gear 39 transmits the rotation thereof to the rewinding gear 40, and the rewinding gear 40 passes through the slip clutch 41, the clutch shaft and the delivery side coupling described later, and the delivery side core 21 of the ink ribbon cassette 21 described above. -2, and when it is present, the rotational drive from the drive transmission gear 38 is transmitted to the delivery side core 21-2, and when it is present, the rotational torque from the delivery side core 21-2 is transmitted to the drive transmission gear. 38. Then, the drive transmission gear 38
An interrupting gear 43 is urged between the rewinding gear 39 and the rewinding gear 39 by the tension spring 44 toward both gears.

The above-described paper feeding mechanism Ma, ribbon feeding mechanism Mb, and head lifting mechanism Mc are each constituted by, for example, a stepping motor or the like. The slip clutch 41 is configured as a braking unit that applies a braking force to the delivery side core 21-2 via a delivery side coupling, which is a driven shaft, which will be described later, and the interrupt gear 43 is the braking unit. And the head lifting mechanism Mc releases the print head 26 from the pressure contact with the platen 27 and the print head 26 with the platen 27.
It is configured as a pressure contact means for pressure contact with. Furthermore, the series of drive control mechanisms as a whole functions as the braking means that is enabled by the interrupt gear 43 that is the braking enabling means in accordance with the pressure contact releasing operation of the head lifting mechanism Mc that is the pressure contact releasing means. It is configured as a control unit that invalidates the control operation of the slip clutch 41 and rotates the delivery side core 21-2, which is a driven shaft, in a predetermined direction, that is, in a direction opposite to the driven rotation direction in which the ink ribbon is sent out. The drive control mechanism as the control means will be further described below.

FIG. 2 shows the ink ribbon cassette 21.
And the winding side core 21-1 and the sending side core 21-
FIG. 3 is a perspective view showing a drive control mechanism that drives 2; For convenience of explanation, the figure is partially shown in an exploded view. Also, in the figure, the same components as those of FIG. 1 are shown with the same numbers as in FIG.

As shown in the figure, the winding side coupling 30 is engaged with the winding side core 30. The winding side coupling 46 is fixed to the drive shaft 47. A slip clutch 48 is fixed to the drive shaft 47, and a gear 49 is rotatably engaged via the slip clutch 48. The winding side coupling 46 is
By the drive gear 50 connected to the ribbon feeding mechanism Mb (32), the gear 49, the slip clutch 48, and the drive shaft 47.
Driven by the winding core 21-1.
Is configured to be rotationally driven in the ink ribbon winding direction.

On the other hand, the delivery side coupling 21 is engaged with the delivery side core 21-2. FIG. 3 (a) is a diagram for explaining the meshing relationship between the gears of the drive control mechanism that controls the drive of the delivery side coupling 52, and FIG. 3 (b).
FIG. 4 is a cross-sectional view showing the configuration of the main part thereof. The drive control mechanism will be described below with reference to FIGS. 2 and 3 (a) and 3 (b).

In these figures, the sending-out side coupling 52 is fixed to a sending-back shaft 53, which is mounted on the inner frame 22-2 of the printing apparatus by a bearing 5.
It is rotatably supported via 4 (see FIG. 3 (b)). The slip clutch 41 is attached to the feed-back shaft 53 so as to be movable in the axial direction with respect to the feed-back shaft 53 and immobile in the rotational direction of the shaft. The slip clutch 41 is engaged with the rewinding gear 40 by sliding friction resistance by the urging force of the spiral spring 56 which is fixed to the feed-back shaft 53 by the retaining ring 55. That is, the rewinding gear 40 is configured to be freely rotatable with respect to the feed-back shaft 53, and to transmit the rotation to the feed-back shaft 53 via the slip clutch 41.

The rewinding gear 40 includes a drive transmission gear 3
9 is meshed. The drive transmission gear 39 is rotatably fitted and supported by a gear shaft 58 fixed to the inner frame 22-2. The gear shaft 58 has a fixed shaft gear 37
Is rotatably provided, and the slip clutch 38 is attached to the gear shaft 58 so as to be movable in the axial direction. The slip clutch 38 engages with the drive transmission gear 39 by sliding friction resistance by the urging force of a spiral spring 60 which is fixed to the gear shaft 58 by a snap ring 59.

The drive transmission gear 39 is rotatably driven by the elevating mechanism gear 36 driven by the head elevating mechanism Mc via the shaft fixed gear 37 and the slip clutch 38, and the transmitted rotation is rewound. It is configured to transmit to the gear 40. Immediately below the meshing portion between the drive transmission gear 39 and the rewinding gear 40, the interruption gear 43 is provided.
Is urged upward by the tension spring 44 as shown by the arrow L in FIG. 3A so as to mesh with both gears.

Next, the operation of the drive control mechanism in this embodiment having the above-mentioned structure will be described with reference to FIGS. Figure 4-
8A and 8B, an operating state diagram of the printer is shown in FIG. 8A, and an engagement state diagram of each gear of the drive control mechanism is shown in FIG. 8B.

First, in the operation state shown in FIG. 4A, the print head 26 shown in FIG. 1 contacts the platen 27 to form a print portion, and the ink ribbon 28 and the image receiving paper 29 are pressed against the platen 27. This is the state when printing is performed. In this state, as shown in FIG. 6 (b), the gears are in a stationary state while meshing with each other. As described above, when the take-up gear 21-1 rotates in the direction of arrow c (clockwise direction) in FIG. 7A to wind up the used ink ribbon 28-1 in response to the progress of the printing operation, Following this winding, the delivery side core 21-2 rotates in the arrow d direction (clockwise direction) in FIG. That is, as shown in FIGS. 2 and 3 (b), the rewinding gear 40 is moved in the arrow m direction (shown in FIG. 4 (b)) via the sending side coupling 52, the sending back shaft 53 and the slip clutch 41. Try to turn it clockwise). The rotational orientation of the rewinding gear 40 tends to rotate the drive transmission gear 39 meshing with the rewinding gear 40 in the direction of arrow n (counterclockwise direction) in FIG. The rotation directions of these both gears are the rotation directions in which the interruption gear 43 is engaged in the direction biased by the tension spring 44. As a result, the interruption gear 43 is meshed from both sides by the drive transmission gear 39 and the rewinding gear 40, and therefore the drive transmission gear 39,
The three gears, that is, the rewinding gear 40 and the interrupting gear 43, form a three-sided mesh with each other. Torque is applied to these three gears in a counterclockwise direction from one of the other two gears and in a clockwise direction from the other two gears. They oppose each other and their rotations are fixed and stopped.

As a result, the slip clutch 41 rotates while making sliding friction with the fixed rewinding gear 40. The sliding frictional resistance applied to the slip clutch 41 is transmitted as a braking force to the sending side core 21-2 via the sliding clutch 41, the sending back shaft 53 and the sending side coupling 52. Due to the braking force transmitted from the slip clutch 41 to the delivery side core 21-2, an appropriate resistance is added to the ink ribbon 28 wound by the take-up core 21-1 and the platen 27, whereby the ink ribbon 28. Is tensioned between the delivery side core 21-2 and the print head 26 with a tension T. In this way, during printing, the ink ribbon 28 between the sending-out side core 21-2 and the print head 26 can be always stretched with an appropriate tension T and sent out toward the printing section.

Next, the operation of the ribbon drive control when replacing the ink ribbon cassette 21 will be described. FIG. 5A shows a state in which the print head 26 suspends the printing operation shown in FIG. 4A and the print head 26 starts to move upward. FIG. 3B shows the meshing state of each gear in this case. As shown in (a) and (b) of FIG.
c (35) is activated to rotate the support shaft 33, which causes the lifting mechanism gear 36 to move in the direction of arrow p in the figure (counterclockwise direction).
The print head 26 is lifted by rotating the head lifting arm 24 in the direction of arrow q (counterclockwise direction) in the figure, and the press contact of the print head 26 with the platen 27 is released. In accordance with this releasing operation, the shaft fixing gear 37 meshing with the lifting mechanism gear 36 rotates in the direction of arrow r (clockwise direction) in the drawing, and the gear shaft 58 (see FIG. 2 or FIG. 3 (b)). And the drive transmission gear 39 is rotated in the same direction via the slip clutch 38. By this rotation, the drive transmission gear 39
Pushes the interruption gear 43 in the direction of arrow s (downward) in the figure against the biasing force of the tension spring 44, and transmits the rotational driving force to the rewinding gear 40. The rotation direction of the rewinding gear 40 by the transmitted rotational driving force is the counterclockwise direction indicated by the arrow t in the figure, and this rotation direction is also the direction in which the interruption gear 43 is pushed downward. by this,
The state in which the torques due to the drive transmission gear 39, the rewinding gear 40, and the interruption gear 43 are counterbalanced by the three sides is released, and the rotational driving force of the drive transmission gear 39 is directly transmitted to the rewinding gear 40. The rotation of the rewinding gear 40 is transmitted to the delivery side core 21-2 via the slip clutch 41, the delivery return shaft 53, and the delivery side coupling 52, and the delivery side core 21-2 is indicated by an arrow in the figure. Rotate in u direction. The rotation of the delivery side core 21-2 causes the ink ribbon 2 to be loosened as the print head 26 moves up.
8 is rewound to the sending side core 21-2 side indicated by the arrow v in the figure. During this period, the rewound ink ribbon 28 is rewound.
Of the circumference (the outer circumference of the unused ink ribbon) corresponding to the rotation angle of the take-up side core 21-1 is the same or the take-up ability is the same. , The lifting mechanism gear 36, the shaft fixed gear 3
7, the gear ratio between the drive transmission gear 39 and the rewinding gear 40 is set. The surplus rotational driving force of the winding operation when the winding capacity is larger is the slip clutch 38.
And is absorbed by the slip clutch 41.

Following the above operation, as shown in FIGS. 6 (a) and 6 (b), the head elevating arm 24 moves the head elevating mechanism Mc.
It is driven by (35) to rotate in the direction of arrow g in the figure, which causes the print head 26 to move to the ink ribbon cassette 21.
It comes out of the head entry / exit hole 25 and stops at the reference position. As a result, the ink ribbon cassette 21 is ready to be pulled out from the printing device. Up to this point, the interrupt meshing of the interrupt gear 43 has been released as described above, and therefore the head lifting mechanism Mc (3
The rotational driving force of 5) is absorbed on the way by the two slip clutches 38 and 41 while absorbing the surplus force of the winding ability.
It is continuously transmitted to the delivery side core 21-2, whereby all the unused portion of the ink ribbon 28 to be loosened is rewound to the delivery side core 21-2, and the ink ribbon 2
As shown in FIG. 7A, the reference numeral 8 is stretched with a tension T between the delivery side core 21-2 and the winding side core 21-1, and is completely stored in the ink ribbon cassette 21.
As a result, the ink ribbon 28 is not caught by the protrusion 23-1 of the cassette insertion port 23, and the ink ribbon cassette 21 can be safely pulled out from the printer and removed.

Next, when a new ink ribbon cassette 21 is newly installed, or when a replacement ink ribbon cassette 21 is installed in place of the ink ribbon cassette 21 removed as described above, the state thereof The operation of shifting from the print state to the print state will be described. The state immediately after mounting the ink ribbon cassette 21 is exactly the same as the state shown in FIG. 6 (a).

FIGS. 7 (a) and 7 (b) show the state in which the print head 26 has descended into the head inlet / outlet hole 25 from the state shown in FIGS. 6 (a) and 6 (b) to the print position. FIG. 3B shows the meshing state of each gear in this case. First, from the state of FIGS. 6 (a) and 6 (b), the head lifting mechanism Mc (35) rotationally drives the support shaft 33 in the direction of arrow R (clockwise direction) in the figure as shown in FIG. 7 (a). Then, when the head elevating arm 24 is rotated in the direction of arrow Q (clockwise direction) and the print head 26 is lowered, the elevating mechanism gear 36 also rotates in the direction of arrow R. At the initial stage of this rotation, the rotation of the lifting mechanism gear 36 causes the rotation of the shaft fixed gear 3 as shown in FIG. 2B (see also FIG. 2A).
7 and the slip clutch 38 to the drive transmission gear 39. As a result, the drive transmission gear 39 rotates in the counterclockwise direction shown by the arrow X in the figure, and the rewinding gear 40 rotates in the direction of the arrow Z (clockwise direction) in the figure in response to this rotation. The directions of rotation of these two gears are the directions in which the interruption gear 43 is engaged in the direction of the arrow Y in the drawing (direction of the meshing portion of the drive transmission gear 39 and the rewinding gear 40) which is biased by the tension spring 44. . As a result, the interruption gear 43 is meshed from both sides by the drive transmission gear 39 and the rewinding gear 40. In other words, the interruption gear 43 is engaged directly below the meshing portion of the drive transmission gear 39 and the rewinding gear 40 to mesh with each other. Thus, the drive transmission gear 39, the rewinding gear 40, and the interruption gear 43 are engaged with each other by forming three three-sided gears, torques in opposite directions are applied from the other two gears, respectively, and rotational torques are counteracted with each other. As a result, these three gears are fixed and stopped. That is, the rotations of the drive transmission gear 39 and the rewinding gear 40 are locked.

In this state, as shown in FIG. 7 (a), the support shaft 33 is continuously driven in the same direction, and the print head 26 descends into the head inlet / outlet hole 25. The rotation of the support shaft 33 is sequentially transmitted to the elevating mechanism gear 36, the shaft fixing gear 37, the gear shaft 58 and the slip clutch 38, and the drive transmission gear 39 is locked by the interrupt mesh of the interrupt gear 43, so that the slip occurs. The clutch 38 idles. Due to the slipping of the slip clutch 38, the support shaft 33 continues to rotate without hindrance, and the head lifting arm 24 is rotated until the print head 26 contacts the platen 27, as shown in FIG. 8A.

On the other hand, by lowering the print head 26,
The ink ribbon 28 is pulled out from the unused portion 28-2. As a result, the sending side core 21-2 is again moved to the arrow d in the figure.
Rotate in the direction (clockwise). This rotation is the sending side coupling 52 and the sending back shaft 53 (see FIG. 3 (b)).
The slip clutch 41 is rotated in the arrow Z direction (clockwise direction) of FIG. Since the rewinding gear 40 is locked by the interruption meshing of the interruption gear 43, the slip clutch 41 idles while performing sliding friction with the rewinding gear 40. Due to the frictional resistance of the sliding friction caused by the idling, the delivery-side core 21-2 causes the slip clutch 4 to move.
1, an appropriate tension T is applied to the ink ribbon 28 that is pulled out by the descent of the print head 26 by receiving an appropriate braking force via the feed-back shaft 53 and the feed-side coupling 52.
And the print head 26 is stretched between the print head 26 and the delivery side core 21-2. This state is similar to the state shown in FIG.

As described above, the mounting of the ink ribbon cassette, the printing process, the replacement of the ink ribbon cassette, etc. are performed as shown in FIG.
~ Repeated as shown in Figure 8. Then, the ink ribbon is pulled out from the printing device, and the ink ribbon is always stretched automatically in the ink ribbon cassette without slack, and is completely stored in the ink ribbon cassette. Further, in the ink ribbon cassette that is removed for replacement while leaving the unused portion, the unused portion of the ink ribbon is automatically wound around the delivery side core.

In the above-described embodiment, even when the interruption of the interruption gear 43 is released, the interruption gear 43 is always in contact with the tips of the drive transmission gear 39 and the rewinding gear 40 and clicks from both gears. Although it is pushed back while being pushed, by setting a predetermined frictional force between the interruption gear 43 and the shaft of the interruption gear, the frictional force and the biasing force of the tension spring 44 are set to be balanced with each other. Due to this balance, when the interruption of the interruption gear 43 is released, the interruption gear 43 may be stopped on the circumference of the drive transmission gear 39 at a position separated from the interruption meshing position by a predetermined distance. In this case, if the swinging fulcrum of the tension spring 44, which is shown to be located below the rewinding gear 40 in the above-described embodiment, is set so as to coincide with the rotation center of the drive transmission gear 39, the interruption gear 43 will operate. The drive transmission gear 39 is constantly in mesh with the drive transmission gear 39 so that it can move on the circumference of the drive transmission gear 39.
The interrupt meshing of No. 3 and the operation of canceling the interrupt meshing are performed more smoothly.

[0045]

As described above in detail, according to the present invention, the ink ribbon cassette that is pulled out from the printing apparatus is always automatically stretched without slack in the ink ribbon cassette, and is completely stretched. Since it is stored in the ink ribbon cassette in such a state, there is no chance that the loose ink ribbon will be caught in the protrusion of the cassette insertion port and damage or cut the unused ink ribbon.
Therefore, the ink ribbon cassette can be easily inserted and removed, and the printing device is convenient and convenient. Also, in the ink ribbon cassette that is removed for replacement while leaving the unused part, the unused part of the ink ribbon is automatically wound up on the sending side core, and when the ink ribbon cassette is reused Since the use of the ink ribbon can be started from a place where the use of the ink ribbon is interrupted, waste of the ink ribbon is eliminated and it is economical. In particular, in the case of a color ink ribbon of one set of three primary colors, the ink portion to be reused can always correspond to the unprinted portion of the image receiving paper with the same size or larger, so that the size incompatibility is the cause. As for the other two colors, the unused part color is not abandoned and the economic efficiency is significantly improved.

[Brief description of drawings]

FIG. 1 is a side sectional view schematically showing a configuration of a main part of a printing apparatus according to an embodiment.

FIG. 2 is an ink ribbon cassette and its winding side core 2;
It is a perspective view showing a drive control mechanism of 1-1 and sending side core 21-2.

FIG. 3A is a diagram for explaining the meshing relationship between the gears of the drive control mechanism that controls the drive of the delivery side coupling;
(b) is a cross-sectional view showing a configuration of a main part thereof.

FIG. 4 (a) is an operation state diagram of the printing device (No. 1), (b)
FIG. 3 is a meshing state diagram (1) of each gear of the drive control mechanism.

FIG. 5 (a) is an operation state diagram of the printing device (No. 2), (b)
FIG. 6 is a meshing state diagram (part 2) of each gear of the drive control mechanism.

FIG. 6 (a) is an operation state diagram of the printing device (No. 3), (b)
FIG. 4 is a meshing state diagram (part 3) of each gear of the drive control mechanism.

FIG. 7 (a) is an operation state diagram of the printing device (No. 4), (b)
FIG. 4 is a meshing state diagram (part 4) of each gear of the drive control mechanism.

FIG. 8 (a) is an operation state diagram of the printing device (No. 5), (b)
FIG. 5 is a meshing state diagram (5) of each gear of the drive control mechanism.

9A is a perspective view showing a side surface of an ink ribbon cassette and a frame of a printing apparatus, FIG. 9B is a front view of the ink ribbon cassette, and FIG. 9C is a sectional view taken along the line AA ′ of FIG.

10A is a diagram showing a state in which an ink ribbon cassette is mounted in a cassette insertion port of a conventional printing apparatus, and FIG. 10B is a diagram showing a state of an ink ribbon during printing.

11A is a diagram showing a state of the ink ribbon when the conventional print head is stopped at an intermediate position, and FIG. 11B is a state in which the print head is raised to a reference position for replacing the ink ribbon cassette. FIG.

[Explanation of symbols]

 1 Ink Ribbon Cassette 2 Frame Side 3 Cassette Insertion Port 3-1 Projection 4-1 Outgoing Side Core 4-2 Winding Side Core 5 Ink Ribbon 5-1 Ink Ribbon Unused Part 5-2 Ink Ribbon Used Part 5- 3 Winding Part 5-4 Loose Part 6 Print Head Inlet / Out Hole 8 Platen 9 Paper Conveying Roll Pair 11 Head Elevating Member 12 Print Head 13 Spindle 14 Image Receiving Paper (Paper) T Tension 21 Ink Ribbon Cassette 21-1 Winding Side Core 21 -2 sending side core 22 frame side 23 cassette insertion port 23-1 protrusion 24 head lifting arm 25 head entry / exit 26 print head 27 platen 28 ink ribbon 28-1 ink ribbon used portion 28-2 ink ribbon unused portion 29 Image Receiving Paper 30 Paper Transport Roll Pair 31 Paper Feed Mechanism Ma 32 Bon feeding mechanism Mb 33 Support shaft 35 Head lifting mechanism Mc 36 Lifting mechanism gear 37 Shaft fixed gear 38, 41, 48 Sliding clutch 39 Drive transmission gear 40 Rewinding gear 43 Interruption gear 44 Tension spring 46 Winding side coupling 47 Drive shaft 49 gears 50 drive gears 52 delivery side couplings 53 feed back shafts 54, 57 bearings 55, 59 snap rings 56, 60 spiral springs 58 gear shafts

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Claims (2)

[Claims] 1. At least a platen, a print head that can be brought into contact with and separated from the platen, an ink ribbon onto which ink is transferred to a sheet by pressure contact of the print head with the platen, and a sub-scan for printing the ink ribbon. A drive unit for transporting the ink ribbon in a predetermined direction, and a driven shaft that winds and holds an unused portion of the ink ribbon and is driven in a predetermined direction by the transport of the ink ribbon by the drive of the drive unit. Braking means for applying a braking force to the shaft, braking enabling means for enabling the braking operation of the braking means, pressure contact releasing means for releasing the print head from pressure contact with the platen, and release of the pressure contact releasing means. Along with the operation, the control operation of the braking means that is made valid by the braking enabling means is invalidated, and the driven shaft is rotated in the direction opposite to the predetermined direction. Printing apparatus, characterized in that it comprises a control means. 2. At least a platen, a print head that can be brought into and out of contact with the platen, an ink ribbon onto which ink is transferred to paper by pressure contact with the platen by the print head, and a sub-scan for printing the ink ribbon. In a printing device having a driving unit that conveys the unused portion of the ink ribbon, and a driven shaft that is driven in the ribbon feeding direction by the conveyance of the ink ribbon by the driving of the driving unit. A slip clutch that applies a braking force to the shaft by a slip friction resistance, an interrupt gear that fixes the gear on the other side on which the slip clutch performs sliding friction to enable the braking operation of the slip clutch, and the print head that moves up and down. A head elevating mechanism for rotating the support shaft of the elevating member to release the print head from the pressure contact with the platen; The control operation of the slip clutch enabled by the interrupt gear is invalidated by transmitting the rotational drive from the head lift mechanism and canceling the interrupt of the interrupt gear in accordance with the pressure contact release operation of the head lift mechanism. By transmitting the rotational drive from the head elevating mechanism to the gear on the other side where the slip clutch performs sliding friction, the driven shaft is moved through the slip clutch in the rewinding direction which is the opposite direction to the ribbon feeding direction. A printing device, comprising: a drive transmission gear that rotates.