JP3038128B2 - Ink ribbon winding device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink ribbon take-up device which supplies an ink ribbon and winds a used ink ribbon after printing in a printing device (printing device) using the ink ribbon.

[0002]

2. Description of the Related Art Conventionally, in a printing device such as a printer,
A laser printer and an LED printer using an electrophotographic system are known, and a printer using a ribbon system in which ink on the ribbon is transferred to recording paper by using an ink ribbon and printing is generally known.

[0003] Printers having the above-mentioned ink ribbon include a thermal printer of a non-impact system by heat, a printer of an impact system by printed characters or a large number of wires, and the like.

Here, in a printer utilizing the ribbon system, an unused ink ribbon is supplied from a rotatable reel around which the used ink ribbon is wound, and after printing is completed, a rotating reel which winds the used ink ribbon is used. It is necessary to use and wind up. Therefore, a take-up reel for taking up a used ink ribbon is provided in one cassette with respect to a supply reel around which an unused ink ribbon is wound, and the take-up reel side is driven to take up in accordance with a printing operation. I have. When an unused ink ribbon is used, the ink ribbon cassette is replaced with a new one.

In particular, the ink ribbon cassette is replaceably provided with a head for printing, for example, a carriage equipped with a thermal head in a thermal printer.
The carriage travels in parallel (main scanning direction) along the recording surface of the recording paper, and scans in a direction orthogonal to the recording paper feed direction. During scanning of the carriage, the thermal head is pressed on the stopped recording paper via the ink ribbon,
By selectively driving the thermal element, printing is performed by thermally transferring the ink of the ink ribbon to recording paper by heat. In synchronization with the traveling of the carriage, the ink ribbon of the ink ribbon cassette is sequentially wound on the take-up reel.

In this case, conventionally, since the ink ribbon is slackened at the start of printing, a printing impossible state or a printing failure occurs, a mechanism for locking, that is, fixing the take-up reel side to prevent slack at the time of printing stop is provided. Have been.

As an example of the configuration of the lock function, various examples are specified in Japanese Patent Application Laid-Open No. Hei 5-24329. For example, those shown in FIGS. 9A, 9B and 9C have a disk portion 51 below a winding shaft 50 provided on a carriage provided with a print head (not shown). A winding gear 52 is provided above. The winding gear 52 meshes with a switching gear 53, and the switching gear 53 meshes with a drive rack 54 fixed to the printing apparatus main body separately from the traveling carriage. Thus, when printing is performed by the carriage traveling rightward in the drawing, the switching gear 53 rotates clockwise, and the winding gear 52 rotates.
Is rotated in the counterclockwise direction, the take-up shaft 50 drives the take-up head 55, which is fitted to the reel in the ink ribbon cassette positioned above the take-up shaft 50, in the take-up direction. You will wind the ribbon.

The switching gear 53 is rotatably supported by a shaft 57 at one end of a switching lever 56 rotatably provided around the winding shaft 50, and has a rotating cam at the opposite end. 58 are in contact. By the rotation of the rotary cam 58, the switching lever 56 is rotated to a position where the switching gear 53 is separated or meshed with the drive rack 54 in particular.

That is, when the rotary cam 58 is at the position shown in FIG. 9A, the switching gear 53 is engaged with the drive rack 54, and the print head moves the recording paper to a platen (not shown) via the ink ribbon. Press to maintain the recorded state.

One end of a wire spring 59 wound around the disk portion 51 is locked by two pins on a portion 56a of the switching lever 56 where the rotating cam 58 contacts. The end is fixed to a pin 60 on the carriage body side. For this reason, in the printing state, the wire spring 59 keeps the winding shaft 50 free without tightening the disk portion 51. Therefore, when the carriage is moved for printing, the take-up gear 52 is rotated in the take-up direction by the drive rack 54 via the switching gear 53, and the used ink ribbon is taken up.

On the other hand, as shown in FIG. 9C, when the rotating cam 58 is rotated to release the pressing of the print head after printing is completed, the switching lever 56 is rotated counterclockwise, and thus the wire spring 59 is rotated. Tightens the disk part 51 to fix, that is, lock, the winding shaft 50. At this time, even if the switching gear 53 is separated from the drive rack 54 at the same time, even if the carriage returns to the home position and travels (in a direction opposite to the traveling at the time of printing), the rotation is not transmitted to the winding shaft 50 and the lock is locked. The state is maintained, and at the time of non-printing, the winding shaft does not rotate,
The ink ribbon does not slack.

FIG. 10 differs from the above-described wire spring 59 in that the disk portion 51 is always in a tightened state. That is, a disk portion 51 is provided below the winding shaft 50 provided on a carriage on which a print head (not shown) is mounted, and a wire spring 61 is wound around the disk portion 51. The bending radius of the wire spring 61 is formed slightly smaller than the radius of the disk portion 51. One end of the wire spring 61 is locked between fixing pins 62 on the carriage. Accordingly, the wire spring 61 slightly tightens the disk portion 51, and the frictional force prevents the winding shaft 50 from reverse rotation, that is, rotation. Therefore, a load is always applied to the winding shaft 51 by the wire spring 61 to prevent the slack of the ink ribbon.

Further, the one shown in FIG. 11 is one in which the reverse rotation preventing claw 63 and the lock claw 64 are simply engaged without providing the disk portion 51 on the winding shaft 50. That is, the lock claw 64 is provided so as to be rotatable about a fulcrum 65 provided on the carriage, and one end 64 a thereof is locked to the one end 56 a side of the switching lever 56, and the locking portion 64 b of the other end is locked. It corresponds to the above-mentioned reverse rotation prevention claw (ratchet) 63.

With this configuration, when the rotating cam 58 is rotated from the state shown in FIG. 11A to the state shown in FIG. 11C, the switching lever 56 is rotated, and the reverse rotation preventing claw 64 is rotated. By rotating clockwise, the claw portion 64b is engaged with the lock claw 63, and the rotation of the winding shaft 50 is locked. At this time, the switching gear 53 is separated from the drive rack 54, and the winding shaft 50 is maintained in a non-rotating state.

During the printing operation, the print head is pressed onto the recording paper via the ink ribbon by rotating the rotary cam 58 to the state shown in FIG. At this time, since the switching lever 56 is rotated, the reverse rotation preventing claw 6
4 is separated from the engaging portion 64b, the take-up shaft 50 is set in a free state, and the used ink ribbon is sequentially taken up on the take-up reel by the rotation of the take-up shaft 50 in association with the movement of the carriage. Can be.

As described above, in the ink ribbon take-up device, at the time of printing, the take-up portion is driven in the take-up direction.
The ink ribbon does not slack, and the ink ribbon does not slack during non-printing because the winding portion is locked.

[0017]

According to the lock mechanisms of the respective ink ribbon winding devices described above, the ink ribbon is locked during non-printing, so that the slack of the ink ribbon is prevented. However, in the case of the one shown in FIG.
That is, since the locked state is maintained, it is necessary to increase the torque for driving the take-up shaft at the time of printing, which may hinder the traveling of the carriage. In particular, when driving the shaft 50 constituting the winding unit by using the drive rack 54 or the like by running the carriage, a motor having a large drive torque is required. Therefore, the size of the printer portion of the printing apparatus becomes large and the cost increases.

Therefore, if it is configured as shown in FIG.
The disadvantage according to FIG. 10 is eliminated. However, at the time of releasing the lock for starting printing, the lock of the winding shaft 50 by the wire spring 59 is released, so that there is a concern that the winding shaft 50 may rotate. That is, the take-up shaft 50 that is in a free state due to the influence of the unlocking, particularly, due to vibration or the like, rotates in a direction opposite to the take-up direction with respect to the ink ribbon. As a result, when the ink ribbon is slackened and the print head is pressed against the recording paper via the ink ribbon, wrinkles and the like are formed on the ink ribbon, which causes a printing failure or a printing failure.

In the lock mechanism of the winding device shown in FIG. 11, if the lock is released, the winding shaft is maintained in a free state. There is a high possibility that the ink ribbon will rotate at the time of separation, and the ink ribbon may be loosened.

Further, a spring member 66 is provided at one end 56b of the switching lever 56 as an urging means of the switching lever 56 in FIG. 11, but a space for mounting the spring member 66 is required, and the number of parts is reduced. This increases the size of the entire mechanism and increases the cost.

In FIG. 9, if the switching lever 56 is returned by the wire spring 59, the urging means described above is not required. When the urging means is used, the cost increases due to the problem of the durability of the wire spring 59 and the like.
A biasing means 66 is provided in the same manner.

In order to reliably engage the reverse rotation preventing claw 63 and the locking claw 64 in FIG. 11, the locking claw 64 is desirably formed of an elastic member, particularly a leaf spring. , Lock Claw 6
It is difficult to form the claw shape 64b of No. 4 into a fine shape, and as a result, the pitch of the reverse prevention claw 63 becomes large, and there is no certainty whether the lock claw 64 hits the peak or the valley of the reverse prevention claw 63. Therefore, delicate lock control becomes difficult. Therefore, the ink ribbon may be loosened.

In the configuration in which the wire spring 59 is tightened, a force for rotating the winding shaft in the tightening direction acts. When the wire spring is loosened, a force for rotating the winding shaft in the direction opposite to the tightening direction is applied. work. That is, when the head moves from the head down state (printing state) to the up state (non-printing state), the wire spring 59 rotates the winding shaft 50 in the normal rotation direction, and when the head moves from the up state to the down state, The wire spring 59 rotates the winding shaft 50 in the reverse direction. for that reason,
Inevitably, the ink ribbon is loosened.

Therefore, when the winding direction of the wire spring 59 is reversed, the operation is reversed, and a force is generated in a direction to loosen the wound ribbon by one cycle operation of head-up / down, and the original function is performed. There was a problem to hurt.

In the thermal printer, the pressing force of the print head is reduced by thermal transfer printing in which recording is performed on recording paper which is plain paper using an ink ribbon and thermal printing in which the recording paper itself is heat-sensitive. Since it is not necessary to wind the ribbon in the thermal printing, the transmission of the driving force for winding the ribbon is cut off, and the switching of the head pressing force in the thermal transfer printing is not performed. For this reason, there is a problem that the head pressing pressure cannot be changed according to the quality of the paper to be transferred, the printing speed, and other operation contents related to ribbon winding.

In view of the above, the present invention, in particular, when the winding portion of the ink ribbon is unlocked, the winding portion can rotate at least in the winding direction, but restricts the rotation in the opposite direction. An object of the present invention is to provide a mechanism to reliably prevent the ink ribbon from loosening.

It is another object of the present invention to simplify the structure of a lock mechanism for achieving the above object of the present invention.

[0028]

In order to achieve the above object, an ink ribbon take-up device according to the present invention uses an ink ribbon for printing by pressing the print head against recording paper via the ink ribbon. In the ink ribbon take-up device provided with a supply unit that supplies the used ink ribbon and a take-up unit that takes up a used ink ribbon used for printing, a member that rotates the take-up unit that takes up the used ink ribbon A locking member that regulates rotation, has a locking claw that engages with the fixing member and locks rotation in the direction opposite to the winding direction, and includes a locking member that is rotatably provided. Has a biasing member for biasing the lock claw in a direction to be engaged with the fixing member, and urges the lock claw to the fixed member side by the biasing member when the print head is not pressed to print. When pressing the head A state in which a part of the urging member is provided so as to be engageable with a mechanism that is interlocked with the pressing drive of the print head so that the urging state by the urging member is released, and the urging force of the urging member does not act. The locking claw engages with the fixing member to lock the rotation of the ink ribbon in a direction opposite to the winding direction.

In the above device, the biasing member is wound around a rotatably provided shaft of the lock member.

Further, the ink ribbon take-up device of the present invention, which achieves the above-mentioned object, comprises a supply unit for supplying the ink ribbon to the print head when printing is performed by pressing the print head toward the recording paper via the ink ribbon. In an ink ribbon take-up device provided with a take-up portion for taking up a used ink ribbon used for printing, a displacement member interlocked with pressing or non-pressing of the print head on the recording paper side, and one end thereof A switching lever having a member that contacts the displacement member and is capable of swinging and that transmits the rotation of the winding portion of the ink ribbon; a fixing member for regulating the rotation of the winding portion; and the fixing member. And a lock member that locks the rotation of the take-up unit by engaging the print head with the recording head in a state where the print head is pressed to the recording paper side in conjunction with the swing of the switching lever. Department of ink ribbon The arrangement feature as away from the ink ribbon take-up portion when rotated in the direction to take.

In the above apparatus, the lock member includes an urging member for urging the lock member toward the fixed member, and the urging member urges the lock member when the print head is not pressed. One end is locked to the switching lever so as to release the bias when pressed.

In the above apparatus, the lock member is rotatably provided coaxially with a shaft provided with a biasing member for biasing the switching lever in a direction in which the switching lever comes into contact with the displacement member. I have.

[0033]

According to the ink ribbon take-up device of the present invention having the above-described structure, the lock member engages with the fixing member for restricting the rotation of the take-up portion of the ink ribbon when recording by the print head is not performed. Are combined. In this case, the lock claw of the lock member is pressed by the urging force of the urging member toward the fixing member in conjunction with the operation of separating the print head from the recording paper, and the lock claw is engaged with the fixing member. Thereby, the rotation in the direction opposite to the winding direction is locked, and the slack of the ink ribbon is eliminated.

When the print head is pressed toward the recording paper to perform printing, the urging of the lock member by the urging member is released in conjunction with this. At this time, even if the winding section of the ink ribbon is rotated in the direction opposite to the winding direction,
Only the biasing state of the biasing member of the lock member is released, but the connection between the lock claw and the fixing member is not released, and the rotation in that direction is locked. Thereafter, by starting printing on the recording paper, if the take-up unit is rotated in the take-up direction, the urging of the lock member is released, and the lock member is moved in the direction in which the lock claw is separated from the fixed member. Rotates. Therefore, the winding section is in a locked state until printing is started, so that the slack of the ink ribbon is eliminated, and the locking member does not become a rotational load at the time of winding, and a driving means having a small rotating torque is provided. The ink ribbon can be wound.

Here, by providing the urging member of the lock member on the rotation shaft of the lock member, the arrangement space can be reduced and the size of the device can be reduced.

Further, according to the ink ribbon take-up device of the present invention, the switching lever is swung by the displacement member interlocked with the press or non-press of the print head against the recording paper, so that the ink ribbon take-up portion is moved to the ink ribbon take-up portion. When transmitting or not transmitting the rotation, when the print head is not pressed, the rotation of the winding unit is not transmitted by the switching lever. At this time, the lock member engages with the fixed member that restricts rotation in the winding section. Therefore, rotation in the direction opposite to the winding direction is locked by the lock member. Thereby, slack of the ink ribbon does not occur.

Then, if the print head is pressed to perform printing, the rotation of the winding section can be transmitted by the switching lever. However, the state where the lock member is engaged with the fixing member is maintained. Therefore, the rotation in the direction opposite to the winding direction is locked, and the slack of the ink ribbon can be prevented. Thereafter, when printing is started and the winding unit is rotated in the winding direction of the ink ribbon, the lock member is separated from the fixing member. As a result, rotation in the direction opposite to the winding direction is enabled, and the load on the winding section is eliminated, so that winding can be performed even when the rotation torque is small.

In particular, by providing an urging member on the lock member and energizing the fixing member, the locked state during non-printing can be reliably performed, and the urging means is released from the urging by the switching lever. By doing so, the fixing member of the lock member can be separated.

Further, by providing the lock member on the shaft provided with the second urging member for bringing the switching lever into contact with the displacement member and also providing the urging member of the lock member, the arrangement space can be extremely reduced. . Therefore, it is possible to reduce the size of the device and contribute to cost reduction.

[0040]

1 and 2 are top views showing the mechanism of an ink ribbon take-up device provided in a printing apparatus according to the present invention. FIG. 1 shows a portion of the ink ribbon take-up device for preventing the ink ribbon from becoming loose. In FIG. 2, the lock state of the ink ribbon take-up shaft is released in order to take up the ink ribbon in a locked state, that is, a state in which the fixed state is maintained.

The carriage of the printing apparatus provided with the ink ribbon take-up device shown in FIGS. 1 and 2 is a perspective view showing a printer unit of the printing device in FIG.
This is indicated by reference numeral 1. The carriage 1 is provided so as to be movable along a slide shaft (not shown). The recording paper is inserted through an insertion opening 4 formed between the feed roller 2 and the guide 3, and the feed roller 2 is fed to the printing position manually or by rotation of a drive motor (not shown).

The feed roller 2 has a drive gear 2b fixed to one end of a rotary shaft 2a rotatably supported on both sides of the printer unit on the side frames 5a and 5b, and a gear meshing with the gear 2b. The rotation of the drive motor is transmitted via the. In parallel with the axis 2a of the feed roller,
A platen (not shown) is arranged at the printing position. The platen is arranged so as to be located on the back side of the recording paper fed while being sandwiched between the feed roller 2 and the driven roller 6. When the print head 7 on the carriage 1 is pressed, the recording paper holds the ink ribbon. Through to the platen.

The above-described slide shaft (not shown) is arranged in parallel with the platen. The carriage 1 is moved along the slide shaft to press the print head 7 against the platen, thereby causing an ink ribbon (not shown). The desired images are sequentially recorded on the recording paper via.

The carriage 1 is provided with two rotatable rollers 8 on the opposite side of the slide shaft from the print head 7 side, and the rollers 8 are formed by pressing and bending the lower frame 9 of the printer unit. It is held on the bent portion plane 9a and moves via the roller 8 on the bent portion plane 9a along the slide axis.

A drive mechanism for running the carriage 1 is transmitted to the timing belt 11 via gears as transmission means by rotation of the carriage motor 10, and a part of the timing belt 11 is fixed to the carriage. 1
Is run along the slide axis as described above. The timing belt 11 is rotatably mounted on the lower frame 9 and provided on both sides of the carriage, and is stretched between the timing gears 12a and 12b.
The timing belt 11 on the side is fixed to the carriage 1.

The carriage 1 further includes a print head 7 for printing, a detection sensor 13 for detecting the end of the ink ribbon, and a supply unit 14 for holding a reel for supplying the ink ribbon in the ink ribbon cassette. A ribbon winding unit 15 for winding a used ink ribbon according to the present invention is provided. The respective reels of the ink ribbon cassette are fitted so as to match the respective heads of the supply unit 14 and the winding unit 15 on the carriage 1, and the ink ribbon cassette is provided detachably. The upper portion of the carriage 1 is a detachable lid 1a. When the lid 1a is removed, the carriage 1 houses the pressing mechanism of the print head 7 shown in FIGS.

Next, the details of the ink ribbon winding device of the present invention will be described with reference to FIGS.

First, in FIG. 1, the interior of the carriage 1 includes a head holder 16 having a print head 7 fixed thereon, a pressing member 17 for pressing the head holder 16, and a pressing member 17 on the carriage table 1b. The cam levers 18 for controlling the pressing state of are respectively rotatably supported coaxially 19. The pressing member 17 has one end of a spring 20 which is an urging means wound around a shaft pin 20a provided on the carriage base 1b, and is locked.
An urging force for constantly urging the print head 6 in the platen direction is applied. The other end of the spring 20 is locked by a stopper 20b of the carriage base 1b.

Further, the cam lever 18 presses the print head 7 against the platen 100 at the printing position and the non-printing position against the urging force of the spring 20 constantly urging in the platen direction. A pin 18 provided on the side opposite to the pivot portion 19 to control the position of the pressed state.
a is inserted into a cam groove 21 a formed in the cam gear 21 that is driven to rotate about a shaft 210 serving as a central axis of the supply unit 14 described above. The cam lever 18 and the pressing member 17 can be locked between the bent portion 18b and the locking portion 17a.

A spring 22 is wound around the support shaft 19. One end of the spring 22 is connected to the cam lever 1
On the 8th side, it is interposed and locked between the bent portion 18b and the corresponding bent second bent portion 18c. And
The other end of the spring 22 is locked by a second bent portion 17b formed on the pressing member 17. Especially the spring 22
The locking portion on the cam lever 18 side is the second portion of the pressing member 17.
In order to be able to be locked to the bent portion 17c,
It is locked between the two bent portions 18b and 18c.

Accordingly, the spring 22 is connected to the second bent portion 17
c, the bent portion 18b of the cam lever 18
And the locking portion 17a of the pressing member 17 are locked, and the pressing member 17 rotates, that is, rotates simultaneously with the rotation of the cam lever 18. This is because when the cam lever 18 rotates counterclockwise in FIG.
Are rotated in the same direction, and are rotated clockwise, the urging force of the spring 20 causes the urging force of the spring 20 to act on the pressing member 17 to press the head holder 16 toward the platen. Do.

Further, if the cam lever 18 is further rotated while the print head 7 is pressed toward the platen 100, one end of the spring 22 is separated from the second bent portion 17c, and the spring 22 is attached. The force promotes the action of further pressing the pressing member 17 further toward the platen 100 together with the spring 20, and further presses the print head 7 further toward the platen 100.

Then, the pressing member 17 and the head holder 16
This means that the bent portion 17d formed substantially at the center is inserted into the opening 16a formed in the head holder 16, and thereby the two are interlocked when the bent portion 17d is locked in the opening 16a. Configuration. However, the pressing member 17
The head holder 16 is pressed at a position 17 e corresponding to the print head 7, and in particular,
7e are separated from the head holder 16
Can be rotated by the above-described interlocking mechanism.

The means for rotating the cam gear 21 is such that a driving gear fixed to a rotating shaft of a cam driving motor (not shown) provided at a lower portion of the carriage base 1b meshes with the cam gear 21, and the rotation of the motor causes the driving gear to rotate. , Cam gear 2
1 is rotationally controlled clockwise or counterclockwise. In this drive, the print head 7 moves the cam lever 1
8, the pressing member 17 and the head holder 16 are pressed or non-pressed to the platen 100 side.

A displacement member is constituted by the head holder 16, the pressing member 17, the cam lever 18, the cam gear 21, and a motor for driving the cam gear 21 to rotate.

The shaft 21a of the cam gear 21 is a central axis of the supply section 14 disposed on the lid 1a of the carriage 1 described above. In particular, the supply section 14 is rotatably provided on the lid 1a of the carriage 1, and The rotation of the supply reel in the ink ribbon cassette is regulated by a spring interposed between the lid 1a and the slack of the ink ribbon is prevented. The supply unit 14 has a shaft insertion hole formed at a position corresponding to the shaft 210, and is arranged so that the supply unit 14 is inserted along the insertion hole.

The take-up unit 15 arranged at a predetermined interval corresponding to the supply unit 14 is provided on the carriage table 1b corresponding to the shaft 21a as shown in the sectional view of FIG. The take-up head 14 a is rotatably provided on the take-up shaft 22.
, And rotatably provided with respect to the through shaft 23.

A winding gear 24 is provided via a friction member 23a so as to be rotatable with respect to the through shaft 23. A spring 24a is provided between the upper part of the winding gear 24 and the lower surface of the winding head 15a. The rotation of the winding gear 24 is transmitted to the supply unit head 15 a via the through shaft 23. As a result, the take-up reel in the ink ribbon cassette mounted on the lid 1a of the carriage 1
By being fitted with 5a, the take-up reel can be rotated. Then, when an excessive rotation force (torque) acts, only the winding gear 24 rotates, and the rotation of the through shaft 23 and the winding head 15a is not transmitted by the friction member 23a and slips. In short, the spring 24a
And the friction member 23a constitute a tri-limiter.

The drive transmission mechanism for rotating the take-up gear 24 has a drive rack 25 fixed at both ends between the frames 5a and 5b of the printer, and a pulley gear 26 meshing with the drive rack 25.
a, a second pulley gear 26b integrated with the pulley gear 26a, an intermediate gear 27 meshing with the second pulley gear 26b, and a switching gear 28 meshing with the intermediate gear 27, and the switching gear 28 is wound. By engaging with the take-up gear 24, the take-up gear 24 becomes rotatable.

In particular, the driving rack 25 is fixed to the left and right frames of the printer unit in parallel with the timing belt 11 of the printer unit shown in FIG. Therefore, when the carriage 1 rotates rightward in the drawing, the pulley gear 26a is driven to rotate clockwise, and finally, the winding gear 24 moves counterclockwise (arrow A).
Direction), thereby winding the ink ribbon. The pulley gear 26 meshing with the drive rack 25
A roller 2 rotatably provided on a shaft pin 29 a provided on the carriage base 1 b and arranged on the back of the drive rack 25.
9, the drive rack 25 is guided, and meshing with the drive rack 25 is performed accurately and reliably.

The drive rack 25, the intermediate gear 27, and the switching gear 28 are rotation transmitting members of the winding portion 15 of the ink ribbon, and the winding gear 24 is a rotating member of the winding portion 15.

The intermediate gear 27 is mounted on the carriage table 1b.
A switching gear 28, which is rotatably provided on a shaft pin 32 coaxial with a rotatable switching lever 31 provided on a shaft pin 30 provided thereon, and which always meshes with the intermediate gear 27, is provided with a switching lever A shaft pin 32 disposed on the shaft 31 is rotatably provided. Therefore, the rotation of the switching lever 31 controls the meshing between the switching gear 28 and the winding gear 24.

As shown in FIG. 4, the switching lever 31 has a locking portion 31a which locks one end of a spring 34 wound around a pin 33 disposed on the carriage base 1b. The urging force of the spring 34 applies a counterclockwise urging force about the shaft pin 30 described above. The other end of the spring 34 is formed on a fixing pin 35 (see FIG. 1) provided on the carriage base 1b.

Then, the spring 34 of the switching lever 31
5 is in contact with an outer cam 21b formed on the upper surface of the cam gear 21, as shown in FIG. 5, and the rotation of the switching lever 31 is controlled in synchronization with the head operation described above. You. That is, when the cam gear 21 rotates, the switching gear 31 is rotated about the shaft pin 32 along the peripheral surface of the outer cam 21b.

The cam groove 21a provided on the lower surface of the cam gear 21 has a first pressing position d and a second pressing position e for changing the pressing force on the print head 7 above the recording position of the print head 7. An outer cam 21b for operating the switching lever 31 in synchronization with the above-described print head operation is formed on the upper surface of the cam gear 21. Therefore, the state of FIG. 1 in which the print head 7 is separated from the platen 100 by rotating the cam gear 21, the first pressing position d for pressing the print head 7 against the platen 100, and the second pressing position e After that, at the position f for separating the head, the rotation of the switching lever 31 in the counterclockwise direction or the clockwise direction is controlled in synchronization with the separation of the print head 7 and the press control.

In the above configuration, when the print head 7 in the state of FIG. 1 is used for printing, that is, when FIG. 1 is in a non-printing state and printing is performed from this state, the driving of the cam gear 21 (not shown) is performed. By rotating the cam motor 21 and rotating the cam gear 21 clockwise, the cam lever 1 moves along the cam groove 21 a formed on the lower surface of the cam gear 20.
8, the cam lever 18 is rotated clockwise. As a result, the pressing member 17 is urged by the urging force of the spring 20 and is rotated so as to follow the rotation of the cam lever 18. Thereby, the pressing member 1
7 corresponds to the head part of the head holder 16
By pressing the back surface, the head holder 16 is rotated clockwise. Thus, the print head 7 presses the recording paper disposed on the platen 100 via the ink ribbon. With the first pressing position c for this printing corresponding to the pin 18a of the cam lever 18, the print head 7
Is pressed against the printing platen 100. This state is shown in FIG.

For this reason, the switching lever 31 is also rotated counterclockwise to move the switching gear 28 in a direction in which the switching gear 28 meshes with the winding gear 24. Then, in a state where the print head 7 is pressed to the first printing position, the switching gear 28 meshes with the winding gear. When the carriage 1 starts moving rightward to perform printing, both the pulley gears 26 are rotated by the drive rack 25, and thus the intermediate gear 27 and the switching gear 2 are rotated.
When the take-up gear 24 rotates counterclockwise via the roller 8, the used ink ribbon is sequentially taken up.

When the printing is completed, the cam gear 21 is driven in reverse to the state shown in FIG. 1 to separate the print head from the platen, and the switching gear 28 is separated from the winding gear 24. In this state, the carriage 1 is driven to return to the left and returned to perform the next line printing. Even when the carriage 1 is driven to return, the winding of the ink ribbon is not performed, and the winding gear 24 is fixed, that is, maintained in a locked state so that the ink ribbon is not loosened.

When the cam gear 21 is further rotated in the state shown in FIG. 2, the pin 1 of the cam lever 18 is moved to the second printing position e.
8a correspond, the cam lever 18 is rotated counterclockwise, and one end of the spring 22 is
7c. At this time, the print head 7 is pressed by the pressing member 17 by the urging force of the spring 20. That is, at the first print position d, the urging force of the spring 22 is also applied to press the print head 7 against the platen 100. In this case, the switching lever 31 is also driven to rotate clockwise, so that the rotation of the winding gear 24 is stopped. For example, printing using thermal paper as recording paper is performed.

A mechanism for locking the take-up gear 24 during non-printing according to the present invention will be described below.

In the lock mechanism, a lock member 40 is rotatably provided on a shaft pin 33 around which a spring 34 for constantly applying a counterclockwise biasing force to the switching lever 31 is wound. As shown in FIG. 6, the lock member 40 has a concave portion 41 into which the coil-shaped spring 39 is inserted, and a sector-shaped opening 42 is partially formed in association with the concave portion 41 so as to correspond to the opening 42. The fixed gear 2 is a fixed member which is a fixing member for restricting rotation of the winding unit 15 integrally formed with the winding gear 24.
Lock claws 44 extended so as to mesh with 40 are integrally molded with resin.

The spring 39 has a wound portion inserted through the concave portion 41, and each end portion passes through the opening 42 and is provided with a locking portion 43.
It is locked to. For this reason, the urging force of the spring 39 is in a state where both end portions are formed in the locking portion 43.
The lock member 40 does not rotate. That is, it is possible to compress one end of the spring 39 toward the other end and to rotate the lock member 40 about the shaft 33 by the bias of the spring.

Therefore, the lock member 40 is connected to the switching gear 3
The lock pawl 44 is rotatably inserted into the shaft pin 33 supporting the spring 34 for biasing the spring 1, and the lock claw 44 corresponds to the fixed gear 240 integrally formed with the above-described winding gear 24, and is arranged in a meshing relationship. Have been. Further, one end of the spring 39 of the lock member 40, that is, the lock claw 44
The end opposite to the position locked with the switching lever 31
Are provided in a relationship corresponding to the locking portion 31a. Therefore, when the lock member 40 is rotated clockwise in FIG. 1, the lock member 40 is urged to rotate counterclockwise in a state where one end of the spring 39 is locked by the locking portion 31, and the fixed gear The lock claw 44 is urged toward the side 240. However, conversely, when the switching lever 31 rotates counterclockwise, the lock with the spring 39 is released, and the lock member 40 remains stopped at the locked position.

In the above configuration, when the print head 7 is in the retracted position (head-up state during non-printing) separated from the printing position, the operating point of the switching lever 31 is the outer cam 2
1b is in contact with the longer diameter side (see FIG. 1). for that reason,
The switching gear 28 is separated from the winding gear 24, and the switching lever 3
1 moves the spring 39 of the lock member 40 counterclockwise. As a result, the lock member 40 receives a rotating action by the urging force of the spring 39, and the lock claw 44
Moves in the direction of the fixed gear 240, the lock claw 44 and the fixed gear 240 are engaged with each other, and the lock claw 44 is completely locked against the rotation of the winding gear 24 in the direction of arrow B, ie, the direction in which the wound ink ribbon is pulled out. State. Therefore, the elastic member of the lock member 40, especially the spring
When the take-up gear 26 is rotated in the direction of arrow A by overcoming the biasing force, the fixed gear 240 can ride over the lock claw 44 of the lock member 40 and rotate in the direction of arrow A. However, in this case, the ink ribbon is not slackened and rotates in the winding direction.

With this configuration, when printing by the print head 7 is not performed, the take-up gear 26
Since the rotation in the direction opposite to the take-up direction (the direction of arrow B) is restricted and locked, the taken-up ink ribbon does not slack. In particular, when the carriage 1 is moved to return to the home position at the end of one-line printing, the print head 6 is in the head-up state (the state shown in FIG. 1) as described above. The ink ribbon does not slack.

Next, when printing is resumed, the print head 6
Is moved from the head-up state to a printing position on the platen (a head-down state in which the head is pressed against the platen), the cam gear 21 is driven to rotate clockwise. Thus, the print head 7 is pressed toward the platen 100 by the cam lever 18, the pressing member 17 and the head holder 16. At this time, the switching lever 31 abuts on the outer cam 21b of the cam gear 21 and moves from the long diameter portion to the short diameter portion, so that the switching lever 31 is urged to rotate counterclockwise by the urging force of the spring 34.

As a result, the cam groove 21a of the cam gear 21
Is rotated to the first printing position d, the switching gear 28 and the winding gear 24 mesh with each other, and the spring 3 of the lock member 40
9 is released from the locking portion 31a of the switching lever 31. Therefore, the spring 39 of the lock member 40
The tension is released (lock member 40 is fixed to fixed gear 24).
Although the urging in the zero direction is released), the lock member 44
Keeps the state in which the lock claw 44 is engaged with the fixed gear 240, and the lock state of the winding gear 26 in the direction of the arrow B is continued.

Therefore, even when the print head 7 is driven in the head down direction, unlike the related art, the rotation of the take-up gear 26 in the slack direction of the ink ribbon does not act on the lock member 44 at all, and the lock is performed. That is, the ink ribbon is not loosened at all.

Thereafter, in response to the print instruction, the take-up gear 40 starts to rotate in the direction of arrow A (the ribbon take-up direction) by the movement of the carriage 1 in the print direction, so that the lock claw 44 of the lock member 40 is moved. The engagement with the fixed gear 240 is released. That is, when the winding gear 24 does not rotate in the state of FIG.
The zero lock claw 44 meshes with the fixed gear 240 and locks the rotation in the B direction. However, the rotation in the A direction releases the tensioned state of the spring 39, that is, one end of the spring 39, as described above. Is released from the locking portion 31a of the switching lever 31, the lock member 40 receives the clockwise rotational driving force and rotates in that direction. Therefore, although the regulation of the rotation in the direction B is released, the ink ribbon is sequentially wound up by the traveling of the carriage, and the ink ribbon does not become loose. Further, since the urging force of the spring of the lock member 40 does not reach, the torque for winding the ink ribbon does not increase.

Here, the principle of releasing the locked state when the print head is driven to the head down state in the lock member, but locking the ink ribbon in the slack direction will be described below with reference to FIGS. 7 and 8. I do.

First, in FIG. 7, the action point of the lock claw 44 that engages with the lock claw 44 of the lock member 40 and the fixed gear 240 is set to P, and the winding gear 24 (engages with the lock claw 44 integrally with the winding gear 24). Consider a case in which a rotational torque T acts in the reverse direction by the fixed gear 240), that is, in the direction in which the ink ribbon is slackened (the direction of arrow B). In this case, the reverse rotation direction of the lock member 44, that is, the shaft pin 3
The rotational force in the counterclockwise direction with respect to 3 is represented by F = T / R. This R is the radius of the fixed gear 240.

The force F in the reverse direction is applied to a force Fx horizontal to the surface of the lock claw 44 of the lock member 40 and a force F
y from the rotation center of the lock member 40
When the distance to the point corresponding to the action point parallel to the vertical force Fy direction is x, and the distance parallel to the horizontal force Fx from the center of the lock member 40 to the action point P is y,
The rotation center position of the lock member 40 and the lock pawl 44 with respect to the rotation center position of the take-up gear 26 so that Fxxx + Fyxy is equal to or greater than "0", that is, Fxxx + Fyxy> 0.
With this configuration, the rotation in the direction opposite to the winding direction of the ink ribbon by the winding gear 24 is locked even if there is no function of urging the lock member 40 toward the fixed gear 240 side. In particular, if the point at which the lock claw 44 of the lock member 40 meshes with the fixed gear 240 is located below the linear portion of the rotation center 33 of the lock member 40 and the rotation center 22 of the fixed gear 240, the above-described relationship is established. Can be maintained.

On the other hand, as shown in FIG. 8, when the take-up gear 24 is rotated in the direction in which the ink ribbon is wound (rotation in the direction A), the rotation torque T due to the rotation direction is increased as described above. , The clockwise rotational force F applied to the lock member 40 is represented by F = T / R. Then, this rotational force F is decomposed into a horizontal force Fx and a vertical force Fy, and when the parallel distances corresponding to the action point P from the center of the lock member 44 are x and y, the lock direction is Is smaller than the rotational moment Fy × y in the unlocking direction, that is, when the relationship of Fxx × <Fy × y is maintained, the winding gear 2
6 is rotated in the direction A to lock the shaft pin 33.
, The clockwise rotation is performed, the lock state is released, and the lock of the winding gear 26 in the B direction is released.

In the above description, the friction of the lock claw 44 at the action point P between the claw 44 and the fixed gear 260 is neglected. In short, the lock claw 44 is maintained so as to maintain the above-described relationship. Center of member 40 and fixed gear 240
The position of the claw 44 relative to the center (coaxial with the winding gear 26)
The above formula can be satisfied by the relationship with the position where the gear engages with the fixed gear 260, and the counterclockwise rotation can be locked in the figure by providing the position where the meshing is performed below the center line. . Here, in order to lock the clockwise rotation, the rotation center of the lock member 40, the fixed gear 2
What is necessary is just to set the rotation center and engagement position of 40.

Further, according to the present embodiment, the lock member 40
When the winding gear 26 is configured to be locked by using the gear, engagement with a fixed gear 260 provided coaxially with the winding gear 26 is used. Instead of such a configuration, the winding gear 26
Another driven gear may be provided to lock the driven gear 26. If the positional relationship with the driven gear is arranged as described above, the object of the present invention can be achieved.

In this case, the lock claw 44 of the lock member 40
The fixed gear 260 meshes with the lock claw 44 that meshes with the teeth even if the teeth of the gear 260 are formed very finely.
Can be easily formed. In other words, if the lock claw 44 has a leaf spring shape as shown in FIG. 10, fine work cannot be performed, and the claw for locking becomes large, and fine lock control cannot be performed. According to this, these are eliminated and very fine lock control can be performed.

The lock member 40 according to the present embodiment is integrally formed of a resin molded product, and a torsion coil spring (spring) is used as an elastic body. Any shape and structure may be used.

[0088]

According to the present invention, the structure of the lock member can be extremely simplified, and at the same time, the rotation in the winding direction can be performed except for the operation of winding the ink ribbon, but the rotation in the opposite direction is enabled. And the locked state is released at the start of printing, so that the slack of the ink ribbon can be completely prevented. In this case, a member for urging the lock member can be provided coaxially with the lock member, so that the arrangement space can be reduced, and miniaturization and cost reduction can be achieved.

In particular, since the lock position of the lock member is not restricted, very fine lock position control can be performed. In other words, lock control can be made fine by making the pitch of the fixing member with which the lock member engages fine.

Further, since the lock member is separated from the fixed member at the start of printing, the lock member does not become a load, and the rotating torque for winding can be reduced.

[Brief description of the drawings]

FIG. 1 is a plan view showing a locked state of an ink ribbon in an ink ribbon winding device according to the present invention.

FIG. 2 is a plan view showing an unlocked state of the ink ribbon in the ink ribbon winding device according to the present invention.

FIG. 3 is a perspective view showing an outline of a printer unit of the printing apparatus according to the present invention.

FIG. 4 is a sectional view showing a winding portion in the ink ribbon winding device according to the present invention.

FIG. 5 is a cross-sectional view showing a switching portion of a winding portion in the ink ribbon winding device according to the present invention.

FIG. 6 is a perspective view showing a structural example of a lock member according to the present invention.

FIG. 7 is a view for explaining the principle of the locked state of the winding portion according to the present invention.

FIG. 8 is an explanatory view showing the principle in the unlocked state of the winding portion according to the present invention.

9A and 9B show a conventional lock mechanism in the ink ribbon winding device, wherein FIG. 9A is a plan view in an unlocked state, and FIG.
Is a cross-sectional view, and (C) is a plan view in a locked state.

10A and 10B show another example of a conventional lock mechanism in the ink ribbon winding device, wherein FIG. 10A is a plan view and FIG. 10B is a cross-sectional view.

11A and 11B show another example of the conventional lock function in the ink ribbon winding device, wherein FIG. 11A is a plan view in an unlocked state, FIG. 11B is a sectional view, and FIG. 11C is a plan view in a locked state. .

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Carriage 1a Cover 1b Carriage stand 7 Print head 14 Supply part 15 Take-up part 16 Head holder 17 Pressing member 18 Cam lever 21 Cam gear 24 Take-up gear 25 Drive rack 27 Intermediate gear 28 Switching gear 31 Switching lever 31a Locking part 33 Shaft pin Reference Signs List 39 spring (biasing means) 40 lock member 44 lock claw 240 fixed gear

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-244885 (JP, A) JP-A-5-24329 (JP, A) JP-A-2-26757 (JP, A) 31755 (JP, U) Hikaru 2-44066 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41J 33/14 B41J 33/52

Claims (5)

(57) [Claims] 1. A supply unit for supplying an ink ribbon to a print head when printing is performed by pressing a print head against recording paper via an ink ribbon, and a winding unit for winding up a used ink ribbon used for printing. In the ink ribbon take-up device provided with a portion, a member for rotating the take-up portion for taking up the used ink ribbon is provided with a fixing member for restricting rotation, and the fixing member is engaged with the fix member and is opposite to the winding direction. A locking member provided to be rotatable, the locking member having an urging member for urging the locking claw in a direction to be engaged with the fixing member; The biasing means biases the lock claw toward the fixed member by the biasing means when the print head is not pressed, and releases the biased state by the biasing member when the print head is pressed. Part of the print head The lock claw is engaged with the fixing member in a state where the urging force of the urging member does not act, and the rotation in the direction opposite to the winding direction of the ink ribbon is locked. An ink ribbon winding device. 2. An ink ribbon winding device according to claim 1, wherein said urging member is wound around a rotatably provided shaft of a lock member. 3. A supply section for supplying the ink ribbon to the print head when printing is performed by pressing the print head toward the recording paper via the ink ribbon, and a winding section for winding the used ink ribbon used for printing. An ink ribbon take-up device having a take-up section, wherein a displacement member interlocked with pressing or non-pressing of the print head to the recording paper side, and one end of the ink ribbon winding device is in contact with the displacement member and is swingable. A switching lever including a member for transmitting the rotation of the take-up section, a fixing member for regulating the rotation of the take-up section, and a lock member that engages with the fixing member and locks the rotation of the take-up section. The lock member is interlocked with the swing of the switching lever, and when the print head is pressed toward the recording paper and the winding unit rotates in a direction in which the ink ribbon is wound, the ink ribbon is wound. Move away from Toribe Ribbon take-up device for placement feature so. 4. The lock member has an urging portion for urging the lock member toward the fixed member. The urging portion urges the lock member when the print head is not pressed, and presses the lock member. 4. The ink ribbon take-up device according to claim 3, wherein one end is locked to the switching lever so as to release the bias sometimes. 5. The lock member is rotatably provided coaxially with a shaft on which a second biasing member for biasing the switching lever in contact with the displacement member is provided, and the biasing member is provided on the shaft. 5. The ribbon winding device according to claim 4, wherein: