JPH074960B2 - How to save ribbon on a thermal transfer printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Outline] When the ribbon feeding is stopped to save the ribbon by retracting the print head according to the length of the blank portion existing in the print line, the blank portion is long. If the ribbon can be saved even if the print head retract distance is increased, the retract distance is increased, the length of the blank portion is shortened, and the print head retract distance is reduced to prevent the ribbon saving. The retract distance is reduced and the ribbon saving efficiency is increased.

[Industrial application field]

The present invention relates to a serial type thermal transfer printer that winds a ribbon while printing, and particularly, to increase ribbon saving efficiency by changing a retracting distance of a print head with respect to a length of a blank portion existing in a print line. The present invention relates to a possible ribbon saving method for a thermal transfer printer.

The serial type thermal transfer printer heats the heating element of the print head to melt the heat-soluble ink on the ribbon, and transfers the heat-soluble ink on the paper to perform printing. In this case, since the ribbon is pushed by the print head and comes into close contact with the paper, the ribbon is wound at the same speed as the moving speed of the print head so as to prevent the ribbon from rubbing the paper and contaminating the paper.

That is, in general, a thermal transfer printer has a ribbon cassette mounted on a carrier that conveys a print head to a print position, and when the print head is in close contact with the paper (hereinafter, abbreviated as “approach”), the ribbon is wound at the same time as printing. The mechanism is such that the ribbon is not wound when the print head is retracted from the paper (hereinafter abbreviated as escape).

The power source of the ribbon winding is a space movement for moving the carrier, and is a winding mechanism linked with the approach / escape mechanism of the print head. That is, when the print head is in the approach state, for example, power is transmitted by a gear that meshes with a gear rotated by a space motor, and when the print head is in the escape state, the gear is separated and the ribbon winding is stopped.

By the way, since the thermal transfer ribbon runs out of ink in the part that has been once transferred, it cannot be used again even if there is a part that is not printed and is not consumed. Therefore, ribbon savings are important.

[Conventional technology]

FIG. 5 is a diagram for explaining the approach / escape state.

FIG. 5 (a) is a top view and FIG. 5 (b) is a side view. 20 is a ribbon cassette, 21 is a print head in an approach state, 22 is a print head in an escape state, 23 is a ribbon in an approach state, 24 is a ribbon in an escape state, 25 is a carrier, and 26 is a platen.

Ribbon cassette 20 is mounted on carrier 25 and print head
When the print head 22 is in the escape state, the ribbon 24 is separated from the platen 26, and when the print head 21 is in the approach state, the ribbon 23 is pulled out from the ribbon cassette 20 by the print head 21. , Closely contact the paper on the platen 26.

If the carrier 25 moves in the direction of arrow A, the ribbon 23 is wound in the direction of arrow B at the same speed as the moving speed of the carrier 25.

Here, the usage state of the ribbon will be described with reference to FIG.

There are cases where one line is printed on the paper, all lines are printed, and there is no printing in the middle. If there is no printing in the middle of this, if the print head is left in the approaching state, printing will be performed at the position indicated by the diagonal lines in FIG. The part that does is not consumed.

Therefore, since the portion of the ribbon corresponding to is wasted, the winding of the ribbon is stopped while the normal print head is in the escape state and printing is not performed.

By the way, the normal print head retreat position is a position that takes ribbon replacement, paper setting, etc. into consideration, and when paying attention only to the winding of the ribbon, it means that the print head is retracted more than necessary.

In other words, when saving the ribbon while traveling the carrier, the length of the non-printed portion may be equal to or more than the pitch at which the carrier moves during the total time required for the escape and the time required for the approach. is necessary.

The large retract distance of the print head means that the escape + approach time becomes long. Therefore, the length of the non-printed portion of the ribbon that can be saved becomes long.

As a countermeasure for this, the print head was retracted to the small retreat position because there was a blank part in one line, with the retreat position of the print head being the minimum retreat position and the normal retreat position as the large retreat position. At times, a ribbon saving method has been proposed in which the print head is retracted to a small retracted position when the ribbon can be saved, and the print head is retracted to the large retracted position when a line feed or ribbon is replaced.

That is, when the print head is retracted to the small retracted position, the movement distance required for retracting the print head is reduced, and the escape + approach time is shortened. % It becomes possible to perform ribbon saving processing on a short blank portion, which is very effective in saving ribbon.

By the way, a pulse motor is used as a power source for retracting the print head to the small retreat position or the large retreat position. Normally, in this type of printer, a small pulse motor is used to perform the approach / escape operation in a shorter time. Therefore, modulation (a control method in which the rotation of the pulse motor is gradually increased at the start and gradually reduced at the stop) may be performed.

FIG. 7 is a diagram for explaining the position of the print head.

When the vertical axis is the print head position and the horizontal axis is time, the position of the print head driven by the modulated pulse motor is the origin Xo when the origin Yo is the platen position.
As the time elapses, the vehicle gradually accelerates and finally moves at the maximum speed, and the distance traveled increases.

When the print head is stopped at the small retreat position Y ₂ where the moving distance is short, the pulse motor gradually decelerates, so if the gear of the ribbon winding mechanism comes off and the position at which ribbon winding is stopped is Y ₁ , The time is X ₂ .

When the print head is stopped at the large retreat position Y ₃ where the moving distance is large, when the print head passes the position of Y ₁ , the pulse motor moves the print head at high speed and
It is X ₁ .

Therefore, the time it takes for the print head to reach the position where the ribbon winding is stopped after the pulse motor is started is
When moving the print head to the large retracted position, X ₂ −
Shows that X _{1 is} enough.

[Problems to be solved by the invention]

When there is a blank area in one line where printing is not performed to save ribbon, regardless of the length of the blank area, if the print head is always retracted to the small retracted position, move the print head to the large retracted position. Even if it is evacuated, as described above in the blank part of the length that approach + escape time is sufficiently long
There is a problem that the ribbon saving efficiency is inferior to the amount of X ₂ −X ₁ hour less.

In view of such a problem, the present invention switches the retracting position of the print head to the small retracting position and the large retracting position according to the length of the blank portion in one line to perform the retracting process of the print head. .

[Means for solving problems]

 FIG. 1 is a block diagram of the principle of the present invention.

Reference numeral 1 is a host device such as a word processor or personal computer, 2 is a display unit of the host device 1, 3 is a body of the host device, and 4 is a keyboard for inputting commands and data to the body 3.

Reference numeral 5 denotes a thermal transfer printer that prints characters and the like under the control of the higher-level device 1, a platen, a print head arranged to face the platen, a carrier that mounts the print head and moves the print head along the platen, A ribbon cassette mounted on a carrier for feeding a ribbon passing between the platen and the print head at a speed corresponding to the moving speed of the print head is provided. When retreating to a retreat position of a different distance from, the timing for stopping the feeding of the ribbon is earlier when the retreat distance is longer than that when the retreat distance is short. 6 indicates from the print data sent by the upper level device 1 for each print line. It is a control unit that detects a blank section in which no character is printed and determines the retracted position of the print head.

The control means 6 of the thermal transfer printer 5 calculates the distance of the non-printing space, that is, the pitch, for each print line from the print data sent by the higher-level device 1, and the ribbon can be saved from the escape + approach time, and the ribbon can be saved at the small retracted position. When it is determined that the print head can be retracted, the print head is escaped to the small retracted position, and when it is determined that the print head can be retracted to the large retracted position with a large pitch, the print head is escaped to the large retracted position. The configuration.

[Action]

With the above configuration, when the thermal transfer printer receives the print data sent from the host device, it detects a blank portion where printing is not designated from the print data for one line, checks the pitch, and if ribbon saving is possible, The print head can be retracted to the small retracted position or the large retracted position according to the size of the pitch. Therefore, when the print head is retracted to the large retracted position, the ribbon feeding stop timing can be made earlier than when the print head is retracted to the small retracted position, and the ribbon can be saved accordingly. .

〔Example〕

FIG. 2 is a block diagram of a circuit showing an embodiment of the present invention.

The processor 7 operates by reading the program from the ROM 8. When print data is input from a host device such as a word processor via the interface circuit 10, the processor 7
The length of the blank portion which is not printed, that is, the pitch is calculated from the print data for one line and stored in the RAM 11 while being stored in the RAM 11.

The processor 7 drives the pulse motor 19 via the approach / escape control circuit 18 to bring the print head 13 into the approach state, extracts the character code from the print data read from the RAM 11, and extracts the corresponding character from the character generation circuit 9. The pattern is read and sent to the print head 13 via the print head control circuit 12 to heat the heating element and transfer the ink on the ribbon onto the paper.

At the same time, the space motor 17 is driven via the space control circuit 16 to move the carrier to position the print head 13 at the print position and perform the space operation. At this time, since the print head 13 is in the approach state as described above, the ribbon is wound at the same speed as the carrier.

FIG. 3 is a diagram for explaining the operation of FIG.

The processor 7 determines the retracted state of the print head 13 based on the pitches of the blank portions in the three states as shown in FIG.

That is, assuming that the shaded portion is the printed portion in one line, the state shown in FIG. 3 (a) is a case where it is determined that the ribbon cannot be saved from the escape of the print head 13 + the approach time because of the small pitch. , Fig. 3 (b) shows the print head
Ribbon can be saved from the escape + approach time of 13, but the retracted position of the print head 13 is the pitch determined to be the small retracted position, and FIG. 3 (c) shows the print head.
The retreat position of 13 is the pitch determined to be the large retreat position.

Therefore, when the processor 7 determines that the pitch is such that the print head 13 can be retracted to the large retracted position, when the blank portion is reached, the pulse motor 19 is driven through the approach / escape control circuit 18 to move the print head 13 to the large retracted position. To evacuate.

When it is determined that the pitch size has only room to retract the print head 13 to the small retracted position, when the blank portion is reached, the pulse motor 19 is driven through the approach / escape control circuit 18 to print at the small retracted position. The head 13 is retracted.

When it is determined that the above pitch does not allow the print head 13 to retract, the processor 7 does not drive the pulse motor 19.

FIG. 4 is a diagram for explaining the effect of the invention.

FIG. 4 (a) shows a case where, for example, ABC is printed on the paper, and there is a long blank, and DEF is printed. Fourth
FIG. 4B shows the difference between the state of FIG. 4A when the ribbon is saved at the small retracted position and when the ribbon is saved at the large retracted position.

In other words, the ink on the ribbon is transferred and leaves a mark of printing ABC, and there is a part that is not consumed as much as the ribbon is fed out during escape + approach time to escape to the small retract position. The trace is left.

On the ribbon, the mark that is transferred and printed as ABC remains,
Escape to retreat to the large retreat position + Approach There is a part that is not consumed as much as the ribbon is fed out during the time, and then a mark of DEF is printed.

In this case, it is shown that, between the ribbon and the ribbon, the ribbon saves more by the ribbon feeding distance α corresponding to the difference between the times X _{2 and} X ₁ shown in FIG. That is, the amount of savings is greater when the print head 13 is retracted to the large retracted position.

When the processor 7 detects a line feed code from the print data, it drives the pulse motor 19 via the approach / escape control circuit 18, retracts the print head 13 to the large retracted position, and drives the line feed motor 15 via the line feed control circuit 14. , Feed the paper.

Further, even when there is no line feed code at the end, the print head 13 is retracted to the large retracted position at the end of printing for one line so that ribbon replacement and paper setting can be performed easily.

〔The invention's effect〕

As described above, according to the present invention, it is possible to perform fine saving processing on the ribbon of the thermal transfer printer according to the size of the print blank pitch.

[Brief description of drawings]

 FIG. 1 is a block diagram of the principle of the present invention, FIG. 2 is a block diagram of a circuit showing an embodiment of the present invention, FIG. 3 is a diagram for explaining the operation of FIG. 2, and FIG. FIG. 5 is a diagram for explaining the approach / escape state, FIG. 6 is a diagram for explaining the ribbon use state, and FIG. 7 is a diagram for explaining the position of the print head. In the figure, 1 is a host device, 2 is a display unit, 3 is a main body, 4 is a key printer, 5 is a thermal transfer printer, 6 is control means, 7 is a processor, 8 is ROM, 9 is a character generation circuit, 10 is an interface circuit, 11 is RAM, 12 is print head control circuit, 13,21,22 is print head, 14 is line feed control circuit, 15 is line feed motor, 16 is space control circuit, 17 is space motor, 18 is approach / escape control circuit, 19 is a pulse motor, 20 is a ribbon cassette, 23 and 24 are ribbons, 25 is a carrier, and 26 is a platen.

Claims (1)

[Claims] 1. A platen, a print head arranged to face the platen, a carrier for mounting the print head and moving the print head along the platen, and a platen mounted on the carrier. A ribbon cassette for feeding a ribbon passing between the print head and the print head in correspondence with the moving speed of the print head, and for saving the ribbon, the print head is retracted at a different distance from the print position in a blank portion in the print line. In the thermal transfer printer (5), when the retracting distance is longer than when the retracting distance is short, the timing of stopping the feeding of the ribbon is earlier, when the retracting distance is shorter, based on the print data sent by the upper apparatus (1) Is provided with a control means (6) for determining the retracted position of the print head by determining the length of the continuous blank portion of the print head. , By increasing the retreat distance, a ribbon saving method of a thermal transfer printer, wherein a length of the air white portion is faster the ribbon feeding stop timing than in the case of following the predetermined value.