JPH01310988A - Method for changing over ribbon position - Google Patents

Abstract

PURPOSE:To perform accurate change-over by shortening the time required in one change-over operation by a method wherein the change-over of the position of a ribbon in the lateral direction thereof with respect to a printing head is separated into two times so as to be performed ont only after printing is finished but also after the movement of a carrier is started and the ribbon is changed over from the present position to a reference position in one of the change-over operations and changed over from the reference position to an indicated position in the other change-over operation. CONSTITUTION:In order to change over the position of a ribbon 33 in the lateral direction thereof from a position P2 to a position P3 with respect to a printing head 11, the ribbon 33 is changed over to a reference position after the finish of printing. In this case, since the time T1 required to change over the ribbon 33 from the present position P2 shown by a dotted line to the reference position P1 shown by a solid line may be short, the change-over of the ribbon 33 can be performed within the time t1 from the point of time after the finish of printing to the point of time when the movement of a carrier is perfectly stopped. Next, the ribbon 33 is changed over from the reference position P1 to the indicated position P3 at the point of time when the carrier starts slow-up. Even in this case, since the time T2 required to change over the ribbon 33 from the reference position P1 to the indicated position P3 may be short, the change-over of the ribbon 33 can be performed within the time t2 from the point of time when the carrier starts slow-up to the starting point of time of printing.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a ribbon position switching method for switching the widthwise position of a ribbon relative to a print head.

[Prior art] In a printer in which a ribbon is inserted between a platen and a print head mounted on a carrier, the ribbon is wound up as the carrier moves, and in the case of a single color ribbon, it is updated to a new surface. In particular, in the case of multicolored ribbons, there is known a method in which the widthwise position of the ribbon relative to the print head is changed in order to change the printing color.

Conventionally, the width direction position of the ribbon relative to the print head has been changed directly from the current width direction position to a designated width direction position after printing is completed or after the movement of the carrier has completely stopped.

[Problems to be Solved by the Invention] As in the past, the width direction position of the ribbon cannot be switched directly from the current width direction position to the specified width direction position, that is, in one step.
In the method of switching over once, even if the switching is performed immediately after printing is completed, the switching operation may be performed while the carrier is completely stopped.

For example, as shown in FIG. 8, the widthwise position of the ribbon 2 relative to the print head 1 is changed to the position shown in FIG.
When attempting to switch from the position shown in FIG. 8B (where the lower end of the ribbon 2 corresponds to the center of
Since the amount of movement is the largest, the time required for switching is also the longest.

Then, as shown in Fig. 7, the switching time T□8 is longer than the time t1 from the end of printing until the carrier slows down and stops completely. A switching operation will be performed. In the case where the width direction position of the ribbon is switched after the movement of the -Ir gear has completely stopped, the ribbon switching operation is naturally performed while the carrier is stopped (the state indicated by the broken line in FIG. 7).

By the way, in the case where the ribbon is wound in conjunction with the movement of the carrier, when the carrier completely stops, the winding of the ribbon also stops, so the ribbon is in a slack state. In this situation, if you change the widthwise position of the ribbon,
Due to slack in the ribbon, the ribbon gets caught in the ribbon guide, making it difficult to accurately switch the widthwise position of the ribbon relative to the print head to a designated position. Therefore, in the case of multicolored ribbons, color mixing is likely to occur.

SUMMARY OF THE INVENTION An object of the present invention is to provide a ribbon position switching method that can accurately switch the widthwise position of the ribbon relative to the print head to a designated position. It is in.

[Means for Solving the Problems] Therefore, in the present invention, the ribbon is wound up in relation to the movement of the carrier having the print head, and the ribbon position switching is performed to switch the widthwise position of the ribbon relative to the print head to a plurality of positions. In this method, the widthwise position of the ribbon is switched to the reference position that takes the shortest switching time from the end of printing to the time the carrier stops, and then In the meantime, the ribbon width direction position is switched from a reference position to a specified position.

[Function] The ribbon width direction position is switched to the reference position between the end of printing and the time the carrier stops, and then the ribbon width direction position is changed to the reference position between the time the carrier starts moving and the time the carrier stops. Switch from to the specified position. In other words, the switch from the current position to the specified position is divided into two times: after printing is finished and after the carrier starts moving, and each time the switch is made from the current position to the reference position and from the reference position to the specified position. Therefore, the switching time each time can be shortened compared to the conventional method.

This means that each switching time can be kept within the time from the end of printing until the carrier stops, or within the time from the time the carrier starts moving until the start of printing.
The widthwise position of the ribbon can be changed while the carrier is moving, that is, while the ribbon is wound up and stretched with a constant tension.

Therefore, the position in the width direction of the ribbon relative to the print head can be changed accurately, and color mixing is likely to occur even with multicolored ribbons.

[Example] Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 6.

In FIG. 3, 11 is a print head, and 12 is a carrier having a print head 11. In FIG. The carrier 12 is provided so as to be movable in a direction parallel to the axis of the platen 14 via two guide rods 13, and is also provided with a drive device 15.
is moved in the same direction by

The drive device 15 includes a carrier moving motor 17 having a timing gear 16 disposed at one end of the platen 14;
A timing gear 18 is rotatably disposed on the other end of the platen 14, and a rack is provided between the timing gears 16 and 18 in parallel with the platen 14, and a part of the frame is connected to the carrier 12.
The timing belt 9 is connected to the timing belt 9. Therefore, when the motor 17 is driven forward and backward, the timing belt 19 is rotated by the forward and reverse rotation of the timing gear 16, so that the carrier 12 is reciprocated in the axial direction of the platen 14.

A ribbon winding gear 22 is meshed with the timing gear 18 via a reduction gear train 21 . The reduction gear train 21 is
The forward and reverse rotation of the timing gear 18 is decelerated so that the ribbon take-up gear 22 is always rotated in one direction, here clockwise in FIG. 3. Shaft 23 of ribbon winding gear 22
A ribbon winding shaft 24 engages with the winding portion 32 of the ribbon cassette 31 via a universal joint (not shown).
are connected. Therefore, the ribbon 33 of the ribbon cassette 31 is wound in the direction of the arrow in conjunction with the drive of the motor 17, that is, in conjunction with the reciprocating movement of the carrier 12.

Both ends of the ribbon cassette 31 are supported by a ribbon shifter M41 shown in FIG. ribbon shift tli1
Reference numeral 41 denotes a ribbon shift arm 43 which detachably holds both ends of the ribbon cassette 31 and has one end rotatably supported by a pin 42 of the printer main body, and a ribbon shift arm 43 which rotates from a ribbon shift motor 44 to gears 45 and 46. A shift cam 50 having a gear 47 that is transmitted through the gear 47, and an engagement lever 49 that is fixed coaxially with the gear 47 and slidably engages with a pin 48 that projects from the one shift arm 43.
including.

The engagement portion 49 of the ribbon shift cam 50 is formed in a spiral shape such that the distance from the center of the gear 47 gradually increases as the ribbon shift cam 50 moves counterclockwise in FIG. Therefore, when the ribbon shift cam 50 is rotated clockwise in FIG. 4 by the drive of the motor 44, the ribbon shift arm 43 is rotated counterclockwise in FIG. 4 using the pin 42 as a fulcrum, and conversely,
When the ribbon shift cam 50 rotates counterclockwise in FIG. 4, the ribbon shift arm 43 rotates clockwise in FIG. 4 about the pin 42 as a fulcrum. As a result, as shown in FIG. 5, the widthwise position of the ribbon 33 relative to the printing pad 11 is changed.

Here, the width direction position of the ribbon 33 with respect to the print head 11 is defined as a position P1 where the center of the ribbon 33 in the width direction corresponds to the center of the print head 11, and a lower end side of the ribbon 33 in the width direction corresponds to the center of the print head 11. and a position P3 where the upper end of the ribbon 33 in the width direction corresponds to the center of the print head 11, respectively. Here, position P1 is assumed to be the reference position. This means that each position P 1
．． This is the position where the switching time from P2 to P3 can be changed in the shortest time.

The circuit configuration is shown in FIG. 6. In the same figure, a CPU 61 is connected to a ROM 63,
An AM 64, a print head drive circuit 65, an I10 interface 66, a timer circuit 67, and an I10 boat 68 are connected, respectively. The ROM 63 stores a program for operating each circuit in a predetermined procedure. The RAM 64 stores print data and the like. The print head drive circuit 65 includes the print head drive circuit 65.
1 is connected. ■10 interface 66 is
It is used for data transmission with other devices. (1) A vapor feed motor 74 is connected to the 10 boat 68 via a vapor feed motor drive circuit 71, and a carrier movement motor 17 is connected to the carrier movement motor drive circuit 72 via a vapor feed motor drive circuit 71.
However, the ribbon shift motors 14 are connected to each other via a ribbon shift motor drive circuit 73.

Next, the operation of this embodiment will be explained.

When the carrier moving motor 17 is driven based on a printing command from the CPU 61, the timing belt 19 is rotated by the rotation of the timing gear 16, so that the carrier 12
is moved in the axial direction of the platen 14. When the carrier 12 moves, that is, when the drive device 15 is driven, the gear 1
8 is transmitted through the reduction gear train 21 to the ribbon winding gear 22.
, the ribbon 33 of the ribbon cassette 31 is wound in the direction of the arrow via the ribbon winding shaft 24.

Therefore, printing can be performed by operating the printing pad 11 while the carrier 12 is moving and the ribbon 33 is being wound up.

In this way, printing is performed while moving the carrier 12, and after a certain period of time after printing is completed, the movement of the carrier 12 is slowed down and the carrier 12 is stopped. At this time, after printing is completed, the ribbon shift mechanism 4
1 to switch the width direction position of the ribbon 33 with respect to the printing pad 11 to the reference position P1.

Eventually, based on the next printing command, the carrier 12 is moved while being slowed down to start printing. At this time, when the carrier 12 starts to slow up, the ribbon shifter Wi41 is activated to switch the widthwise position of the ribbon 33 relative to the printing pad 11 to a designated position.

For example, in order to switch the width direction position of the ribbon 33 with respect to the printing pad 11 from the position (P2) in FIG. 8(A) to the position C (P 3 ) in FIG. 8(B), As shown, after printing is completed, the ribbon 33 is switched to the reference position I) 1 (see Figure 2 (A)).
Since the time 'r1 for switching from the current position P2 of the IR line > to the reference position P1 of the solid line may be short, it can be done within the time t1 from the end of printing until the movement of the carrier 12 completely stops.

Next, when the carrier 12 starts to slow up, the ribbon 33 is switched from the reference position P1 to the specified position P3 (see FIG. 2(B)). In this case, too, the ribbon 33 is switched from the reference position P1 to the specified position P3. Although the time T2 for switching up to 1 is short, it can be done within the time t2 from when the carrier 12 starts slowing up to when printing starts.

Therefore, according to this embodiment, the ribbon 33 is switched to the reference position P1 after printing is completed, and then the ribbon 33 is switched from the reference position P1 to the specified position after the carrier 12 starts slowing up. ribbon 33
The switching is performed twice: after printing is finished and after the carrier 12 starts slowing up, and each time the switching is performed from the current position to the reference position P1 and from the reference position P1 to the specified position. This means that the switching time can be reduced by keeping each switching time within the time t1 from the end of printing until the carrier 12 completely stops, or within the time t2 from the time the carrier 12 starts moving until the start of printing. Therefore, the widthwise position of the ribbon 33 can be changed while the carrier 12 is moving, that is, while the ribbon 33 is wound up and stretched with a constant tension.

Therefore, the widthwise position of the ribbon 33 relative to the print head 11 can be changed accurately, and color mixing is unlikely to occur even with multicolored ribbons.

In the above embodiment, the widthwise positions of the ribbon 33 are divided into three positions P1. P2. P3, that is, the position p where the center position of the ribbon 33 in the width direction corresponds to the center of the print head 11
1. It is possible to switch to a position P2 where the lower end of the ribbon 33 corresponds to the center of the printing pad 11 and a position P3 where the upper end of the ribbon 33 corresponds to the center of the printing pad 11. However, the switching of the width direction position of the ribbon 33 is not limited to the above three positions zp, p, p3, but may be at two or four or more positions. In this case, the reference position may be determined to be the position where the switching time to these multiple positions is the shortest.

Further, in the above embodiment, the ribbon shift arm 43 holding the ribbon cassette 31 is rotated about the pin 42 to change the widthwise position of the ribbon 33 with respect to the print head 12. The ribbon 33 may be configured to be movable in a direction perpendicular to the central axis of the print head 11, thereby changing the position of the ribbon 33 in the width direction.

[Effects of the Invention] As described above, according to the present invention, the position of the ribbon in the width direction with respect to the print head is switched twice: after the end of printing and after the start of movement of the carrier. Since the switching is performed from the current position to the reference position and from the reference position to the specified position, the time required for one switching operation can be kept within the movement of the carrier, that is, during the ribbon winding operation.

Therefore, since the ribbon is stretched with a constant tension, the position of the ribbon in the width direction can be accurately switched to a designated position.

[Brief explanation of the drawing]

Figures 1 to 6 show one embodiment of the present invention.
The figure is a timing chart showing the operation, Figure 2 is a diagram showing the switching state of the ribbon width direction position with respect to the print head,
FIG. 3 is a perspective view showing the schematic configuration of the printer, FIG. 4 is a diagram showing the ribbon shift am, FIG. 5 is a diagram showing the relationship between the print head and the ribbon, and FIG. 6 is a block diagram showing the circuit configuration. be. 7 and 8 show a conventional example. FIG. 7 is a timing chart, and FIG. 8 is a diagram showing a switching state of the position of the ribbon in the width direction with respect to the print head. 11...Print head, 12...Carrier, 33...
·ribbon.

Claims (1)

[Claims] (1) In a ribbon position switching method in which the ribbon is wound up in relation to the movement of a carrier having a print head, and the widthwise position of the ribbon relative to the print head is switched to multiple positions, the period from the end of printing until the carrier stops Then, switch the ribbon width direction position to the reference position with the shortest switching time to the listed positions, and then, between the start of carrier movement and the start of printing,
A ribbon position switching method characterized by switching the ribbon widthwise position from a reference position to a specified position.