JPS6087086A - Printer - Google Patents

Abstract

PURPOSE:To securely take up a ribbon already used for printing and prevent overlapped printing from occurring when starting a printing operation, by a method wherein a lever turned in company with the movement of a printing head to a non-printing position is provided, and a spool is rotated by a predetermined amount by turning the lever. CONSTITUTION:When a main body 5 of the carriage with the printing head 8 mounted thereon is moved rightward, a driving gear 33 engaged with a driving belt 15 is rotated by a predetermined amount. The rotation is transmitted to a driven gear 19 through intermediate gears 34, 38, 37, and a one-way clutch 20 permits a spool shaft 17 to rotate in a direction for taking up the ribbon. When a printing head 8 is turned to a non-printing position in company with a carriage-returning operation, a slant surface 11a thereof is engaged to an engaging part 39 of a releasing lever 35 to turn the lever 35 clockwise. By this turning, the intermediate gear 38 is released from the intermediate gear 34, and rotates the spool shaft 17 through the gears 37, 19, thereby taking up the ribbon.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention includes a print head movable between a printing position and a non-printing position l mounted on a carriage movable along a platen, and a ribbon mounted on the carriage. The present invention relates to a printing device to which a cassette is detachably attached.

Prior Art Generally, in a type of thermal printer in which a ribbon is wound up as the carriage moves each time printing is performed, the print head is moved from a printing position to a non-printing position when inserting paper, starting a new line, etc. In some cases, the printed ribbon may not be completely wound up due to loosening of the printing ribbon or vibrations in the drive system such as the ribbon winding mechanism, and the print head may print again at the same position. In other words, there was a risk that overlapping shots would occur.

Purpose of the invention This invention was made in view of the above circumstances, and
The purpose of this is to be able to wind up the printed ribbon when the print head is moved from the printing position to the non-printing position, to prevent overprinting, and to ensure clear printing at all times. The purpose is to provide a printing device.

Structure of the Invention In order to achieve the above object, the present invention provides a carriage with a drive gear that is rotatably driven as the carriage moves, and a spool shaft that is rotatably driven to rotate the ribbon spool of the ribbon cassette. At the same time, a rotation transmission mechanism is installed to operatively connect the drive gear and the driven gear to the non-printing position of the print head. As the ribbon moves, the operative connection between the drive gear and the driven gear is released, and the driven gear is rotated for a predetermined period in the ribbon winding direction.

Embodiment A first embodiment in which the present invention is embodied in a thermal printer will be described below with reference to FIGS. 1 to 5.

A frame (not shown) of the thermal printer is provided with a platen 1 extending in the longitudinal direction, and a paper guide section 2 and a paper feed roller 3 are disposed within the frame below the platen 1.

A carriage body 5 is attached to a support shaft 4 extending parallel to the platen 1 below the platen 1, and a carriage body 5 is attached to the left and right shaft supports 6.
It is movably supported at the rear end, and its rear lower surface is supported on a guide member (not shown). A helad carriage 7 is rotatably supported on the support shaft 4 between the two wheel supports 6 at its base end. Said herad carriage 7
A print head 8 facing the platen 1 is provided on the upper surface of the printer. At the base end of the print head 8, there is a projecting piece 1 provided with an inclined surface 11a that slopes from above toward the rear and below.
1 is formed. The tension spring 12 also urges the print head 8 to rotate in the counterclockwise direction in FIG. 2 together with the head carriage 7. A release lever 10 controlled by the control device of the thermal printer is disposed inside the frame so as to be opposite to the protruding piece 9 protruding from the rear side of the head cut ridge 7. The protruding piece 9 is always engaged by the spring force of the tension spring 12. When the release lever 10 is placed at the solid line position in FIG. 2, the print head 8 together with the head carriage 7 is held at the printing position shown by the solid line in FIG. Further, when the release lever 10 is placed at the position indicated by the chain line in FIG. 2, the printing head 8 together with the helad carriage 7 is placed at the non-printing position shown by the line shown in the same figure.

A drive pulley 13 and an idle pulley 14, which are driven to rotate in both forward and reverse directions by a drive motor (not shown), are provided on both left and right sides of the frame, and both pulleys 13
．． Endless toothed (=J) drive belts i to 15 are hung between the belts 14 and 14. A part of the drive belt 15 meshes with a toothed wall 16a protruding from the upper surface of the carriage main body 5. At the same time, in this state, it is held between the toothed wall 16a and the plurality of holding walls 16b and 16c.

As shown in FIGS. 1, 3, and 5, a spool shaft 17 for taking up a ribbon is rotatably protruded from the upper surface of the carriage body 5 in front of the drive belt 15. A connecting tube 18 is fixed to the upper end of the tube.

A driven gear 19 is loosely fitted on the base end side of the spool shaft 17.

A coil spring 22 is wound around the spool shaft 17 between the connecting cylinder 18 and the driven gear 19, and a rotation transmission disk (not shown) is fixed to the spool shaft 17 below the driven gear 19. Therefore, the spring force of the coil spring 22 causes the driven gear 19 to
is pressed against the rotation transmission plate, so that both 17 and 19 can rotate together.

A one-way clutch spring 2 is provided at the base end of the spool shaft 17 between the driven tooth $19 and the upper surface of the carriage body 5.
0 is wound, and its outer end is held between a pair of fixing pieces 21 on the carriage body 5. The spool shaft 17. The connecting spring 18 and the driven gear 19 can rotate only in the ribbon winding direction, that is, in the direction of the arrow in FIG. 5, by the action of the one-way clutch spring 20.

To the right of the ribbon winding spool shaft 17, a ribbon supplying spool shaft 23 is rotatably protruded on the Killerridge main body 5, and a connecting cylinder 24 is fixed to the upper end of the spool shaft 23. .

At the base end of the spool shaft 23, the spool shaft 23
A spring 25 having a smaller spring force than the one-way clutch spring 20 is provided between a pair of circles (23a) that can rotate together with the one-way clutch spring 20.
is wound, and its outer end is attached to the fixed piece 2 on the carriage body 5.
6.

When the spool shaft 23 is rotated in the ribbon supply direction, that is, in the direction of the arrow in FIG.
Rotational resistance is provided by this.

The ribbon cassette 27 is detachably mounted on the carriage main body 5, and on the bottom wall 27a of the ribbon cassette 27, a winding ribbon spool 28 is rotatably fitted onto the connecting tube 18 of the ribbon winding spool shaft 17. A supply spool 29 for ribbon supply, which is housed in the ribbon supply spool shaft 23 and externally fitted onto the ribbon supply spool shaft 23, is rotatably housed.

A pair of left and right ribbon passing ports 27b that open on both sides of the print head 8 are formed at the rear edge of the ribbon cassette 27, and the ribbon passes between the right passing port 27b and the supply ribbon spool 29. Bottom wall 2 of cassette 27
A substantially arcuate guide wall 30 is formed protrudingly on 7a. A tension-applying leaf spring 31 is fixed at its base end between the guide wall 30 and the rear inner wall of the ribbon cassette 27. And the supply ribbon spool 29
The thermal transfer ribbon R wound around is inserted between the guide wall 30 and the plate spring 31, and is supplied to the front of the print head 8 through the right ribbon passage port 27b, and then is supplied to the front of the print head 8 through the ribbon passage port 27b on the left side. The ribbon is wound through the ribbon spool 28 for winding.

A driving body 32 that can rotate around a shaft 32a is provided on the C-killing body 5 at the gates of the two spool shafts 17. A drive gear 33 is provided that is always in mesh with the drive belt 15. When the head carriage 7 is moved to the right (forward direction) together with the carriage body 5 as the drive belt 15 rotates, the drive gear 33 is engaged with the drive belt 15. The drive gear 33 is rotated clockwise in FIG.

On the other hand, when the head carriage 7 is moved to the left (reverse direction) together with the carriage body 5, the drive gear 3
3 is rotated counterclockwise in FIG.

A first middle U gear 34 is provided on the upper part of the driving body 32.
). A shaft 36 is provided between the driving gear 33 and the driven gear 19 and protrudes from the C1 carriage main body 5.
A release lever 35 serving as a first release means is rotatably supported at approximately the middle portion thereof. Also, this shaft 36
A second intermediate gear 37 is rotatably positioned above the release lever 35 and is always in mesh with the driven gear 19. Furthermore, a third intermediate gear 38 is rotatably supported on the release lever 35, and is always engaged with the second intermediate gear 37 and can be engaged with and disengaged from the first intermediate gear 34 as the release lever 35 rotates. has been done.

An engaging portion 39 that can engage and disengage from the inclined surface 11a of the protruding piece 11 on the print head 8 is integrally formed at the rear end of the release lever 35. Further, as shown in FIG. 5, a tension spring 40 urges the release lever 35 to rotate in the counterclockwise direction in FIG. 11 about the shaft 36.

A substantially circular coiled spring 41 as a second release means is wound around a groove 32b formed on the outer periphery of the drive body 32 between the drive gear 33 and the first intermediate gear 34.
A fixing piece 42 is provided to protrude from the carriage body 5 so as to be opposed to the linear outer end protrusion, and an engaging piece 43 is formed to protrude from the release lever 35 .

Next, the operation of the thermal printer configured as described above will be explained.

Now, when attaching the ribbon force sets 1 to 27 to the carriage body 5, first, the release lever 10 shown in FIG.
is located at the position indicated by the chain line in the figure.

Thereby, based on the spring force of the tension spring 12, the print head 8 on the head carriage 7 is placed and held in the non-printing position shown by the chain line in the figure. Then, the inclined surface 1 of the print head 8
1a, the release lever 35 is placed in the received position as shown in FIG. Placed. In this state, the ribbon cassette 27 is placed on the carriage main body 5, and the ribbon spool 28 for winding the ribbon cassette 27 is placed on the carriage body 5.
is fitted onto the ribbon take-up spool shaft 17, and the supply ribbon spool 29 is fitted onto the ribbon supply spool shaft 23.
Then, if a part of the thermal transfer ribbon R exposed to the outside of the ribbon cassette 27 is placed in front of the print head 8 through the ribbon passage port 271), the ribbon cassette 27
installation can be completed.

Next, when a predetermined character key is pressed, the release lever 10 shown in FIG. 2 is automatically moved upward to the solid line position in the figure based on the action of a control device (not shown).

Therefore, the print head 8 is rotated together with the head carriage 7 against the spring force of the tension spring 12 to the printing position shown by the solid line in FIG. The head 8 is placed and held at its printing position. As the print head 8 rotates, the release lever 35 can be rotated in the opposite direction. Thereby, the release lever 35 is rotated to the position shown in FIG. 3 based on the biasing horn of the tension spring 40, and the third intermediate gear 38 on the release lever 35 is moved to
, the drive gear 33 engages with the first intermediate gear 34 . It is operatively connected to the driven gear 19 via a third intermediate gear 38 and a second intermediate gear 37 . Further, the print head 8
As the thermal transfer ribbon R rotates, the thermal transfer ribbon R is slightly pulled out from the supply spool 29 against the urging force of the spring 25 shown in FIG. 5 and the plate spring 31 shown in FIG. It is pressed against the normal printing paper P on the paper 1.

In this state 43, the print head 8 is controlled by the control device.
Characters are printed on the printing paper P by being activated. Subsequently, the drive pulley 13 is rotated a predetermined m clockwise in FIG. 1, and the carriage body 5. When the head carriage 7 and the print head 8 are integrally moved to the right in FIG. 1, that is, in the forward direction, the drive gear 33 rotates a predetermined m in the IT force direction as shown in FIG. 1 based on engagement with the drive belt 15. be done.

At this time, the outer end of the winding spring 41 engages with the fixing piece 42 on the carriage body 5, and based on this engagement, the winding spring 4
1 and the groove 32b of the driver 32.

As the driving gear 33 rotates, the driven gear 19 is rotated by a predetermined amount in the counterclockwise direction in diagram M3, that is, in the ribbon winding direction, via the first to third intermediate gears 34, 37, and 38.
The spool shaft 17 is integrated with the driven gear 19. The connecting tube 18 and the ribbon take-up spool 28 are rotated. Based on this, the printed thermal transfer ribbon R is wound onto the take-up ribbon spool 28 against the urging force of the leaf spring 31 and the spring 25, and the unprinted ribbon R is let out from the supply ribbon spool 29. Therefore, the next digit can be printed.

In addition, when newly loading printing paper P into this printing device or performing a line feed operation, release lever 10 shown in FIG.
When is placed at the position indicated by the chain line in the same figure, the print head 8 together with the head carriage 7 rotates based on the spring force of the tension spring 12 from the printing position shown by the solid line in Fig. 2 to the non-printing position shown by the chain line in the same figure. be done. The loosening of the thermal transfer ribbon R caused by the rotation of the print head 8 is caused by the ribbon cassette 27
This is absorbed by the inner leaf spring 31 being rotated from the position shown in FIG. 3 to the position shown in FIG. 4 based on its own elastic horn.

Further, as the print head 8 rotates, the inclined surface 11a of the protruding piece 11 engages with the engaging portion 39 of the release lever 35, and the w4 release lever 35 is released against the spring force of the tension spring 40. It is rotated from the position shown in FIG. 3 to the position shown in FIG.

Then, as shown in FIG.
4 teeth are arranged, and when the print head 8 moves to the non-printing position, the rotation of the drive gear 33 and the first intermediate gear 34 is stopped and the print head 8 is fixed on the carriage main body 5. Therefore, when the teeth of the third intermediate gear 38 are separated from the teeth of the first intermediate gear 34 as the release lever 35 is rotated clockwise in FIG. The gear 38 is rotated in the counterclockwise direction 11 in FIG. Based on the rotation of the third intermediate gear 38, the second intermediate gear 37
．． Through the driven gear 19, the spool shaft 17. Connecting tube 1
8 and the winding ribbon spool 28 are rotated by a predetermined amount in the winding direction, and the thermal transfer ribbon R is wound up.

Further, after the third intermediate gear 38 is rotated counterclockwise in FIG. 6 with the rotation of the release lever 35, the third intermediate gear 38 is completely removed from the first intermediate gear 34. apart,
The operative connection between the drive gear 33 and the driven gear 19 is released.

As described above, in this embodiment, when the print head 8 is moved to the non-printing position, the printed thermal transfer ribbon R is wound up by a predetermined amount, so the print head 8 is placed at the printing position again and printing is performed. When the operation is performed, it is possible to prevent the risk of over-striking occurring.

Second Embodiment Next, a second embodiment embodying the present invention will be described with reference to FIG. In this embodiment, a ratchet wheel 50 is provided above the second intermediate gear 37 and rotates integrally with the second intermediate gear 37 around the shaft 36.
A supporting piece 51 extending back and forth is attached to the release lever 35 at its base end by a pair of screws 52 between the releasing lever 35 and the engaging portion 39 . A ratchet 53 is rotatably supported at the tip of the support piece 51. Of the pair of screws 52, a coil spring 54 is wound around the front screw 52 at its intermediate winding portion, and one end of the spring 54 is wound around the front screw 52, and one end of the spring 54 is wound around the front screw 52.
At the same time, the narrow end is fixed to the support piece 51. Then, this coiled spring 54 causes the ratchet 5 to
3 is urged to rotate in the direction in which it engages with the teeth of the ratchet wheel 50.

Therefore, when the print head 8 is moved from the printing position to the non-printing position and the release lever 35 is rotated from the chain line position in FIG. 7 to the solid line position in the same figure, the ratchet 53 on the support piece 51 engages with the teeth of the ratchet wheel 50 to rotate the ratchet wheel 50 by a predetermined amount in the assembling direction in FIG. And this ratchet wheel 5
The rotational movement of the ratchet wheel 50 is transmitted to the driven gear 19 via the second intermediate gear 37 that rotates integrally with the spool shaft 17, and the spool shaft 17 is rotated a predetermined m in the ribbon winding direction. The printed thermal transfer ribbon R is wound onto the ribbon spool 18.

In this manner, also in this embodiment, the printed thermal transfer ribbon R can be wound up based on the fact that the head ridge 7 is moved to the non-printing position, and overprinting can be prevented.

Effects of the Invention As detailed above, the present invention allows the printed ribbon to be wound up as the print head is moved to the non-printing position, thereby preventing overlapping when starting the printing operation again. Qin has the excellent effect of being able to reliably prevent.

[Brief explanation of drawings]

Fig. 1 is a plan view of a thermal printer embodying the present invention, Fig. 2 is a sectional view of main parts, Figs. 3 and 4 are plan sectional views showing a state in which a ribbon cassette is loaded, and Fig. 5 is A partial perspective view, FIG. 6 is a partial enlarged plan view showing the meshing state of gears,
FIG. 7 is a plan view of essential parts showing a second embodiment embodying the present invention. Platen 1. Carriage body 5. Head carriage 7 (
5.7 constitutes a carriage), a print head 8. Ribbon winding spool shaft 17. Driven gear 1
9. Ribbon cassette 27° Ribbon spool for winding 28.
Drive gear 33. First intermediate gear 34. Second intermediate gear 3
7. Third intermediate gear 38 (34, 37, 38 constitute a rotational transmission mechanism). Patent Applicant: Brother Industries, Ltd. Patent Attorney - On 1) Hironobu

Claims (1)

[Claims] 1. A key 1!1 notch (5, 7) that is movable along the platen (1), and a printing device and a position q' on the key ridge (5, 7). The day when it was placed movably between
), and a cassette (27) installed in the carriage (5, 7), the carriage (5, 7) is equipped with a carriage (5, 7).
); a drive gear (33) that is rotated as the gear moves;
1 nobon spool (28) of the ribbon cassette (27)
) and a driven gear (19) for rotationally driving the spool shaft (17) for rotating the motor. Rotation transmission 11f1 (34
, 37, 38), and as the print head (8) moves to the non-printing position, the operative connection between the driving gear (33) and the driven gear (19) is released and the driven gear A printing device characterized in that a gear (19) is configured to be rotated by a predetermined amount in a ribbon winding direction.