JPH0729467B2 - 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 retract distance of the print head Less,
By reducing the time it takes to approach and escape the printhead, the length of blank space available for ribbon savings is reduced.

[Industrial application field]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a serial type thermal transfer printer that winds a ribbon while printing, and more particularly to a thermal transfer printer that enables ribbon to be saved even in a small blank area existing in a print line.

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, the ribbon is pushed by the print head and comes into close contact with the paper, so that the ribbon is wound at the same speed as the print head moving speed 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 approach state, the position of the shaded area in FIG. 4 will be printed, and the ribbon will be consumed 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.

[Problems to be Solved by the Invention] By the way, the retreat position of the normal print head is a position in consideration of ribbon replacement, paper setting, etc. It has been evacuated.

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, there is a problem that the length of the non-printed portion of the ribbon that can be saved becomes long.

Further, if the carrier is stopped and the escape and approach are performed, there is a problem that it takes too much time for the escape / approach, the print processing speed decreases, and the efficiency deteriorates.

In view of such a problem, the present invention provides escape + by setting the retracted position of the print head to the minimum required distance.
It shortens the approach time.

[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 is a thermal transfer printer that prints characters and the like under the control of the host device 1, and reference numeral 6 is a print data sent from the host device 1 that detects a space in which no character is printed for each print line and controls the retreat distance of the print head. It is a control means.

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 upper level device 1, and when it is determined from the escape + approach time that ribbon saving is possible, the minimum Limit evacuation position,
That is, the print head is escaped to the small retracted position, and the print head is escaped to the retracted position similar to the conventional one, that is, the large retracted position at the time of line feed and ribbon replacement.

[Action]

With the above configuration, when the thermal transfer printer receives the print data sent from the host device, it detects a blank portion in which 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 a small retracted position.

〔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.

The processor 7 drives the pulse motor 19 through the approach / escape control circuit 18 when reaching the blank portion when there is a ribbon saving pitch by the pitch of the blank portion calculated and stored in the RAM 11 in advance, The print head 13 is retracted to the retracted position.

FIG. 3 is a diagram for explaining the retracted position of the print head.

26 indicates the position of the platen, indicates the position of the print head 13 in the approach state, indicates the position of the print head in the small retracted position, and indicates the position of the print head 13 in the large retracted position.

If the distance indicated by A is the range in which ribbon winding is performed and the distance indicated by B is the range in which ribbon winding is not performed,
The range indicated by C is an unstable winding region. This is because the power of the space motor 17 is transmitted by meshing the gears as a power source for winding the ribbon in response to the switching of the approach / escape of the print head 13 as described above, but there is variation in the range where the gears are separated. is there.

Therefore, the small retreat position is determined to be a position that avoids the unstable region C and has a minimum distance from the platen 26.

Therefore, assuming that the position of the print head when the pulse motor 19 operates N steps from the approach state is the large retract position, the position of the print head when the pulse motor 19 operates N-ΔN steps is the small retract position.

In this case, the ribbon saving process can be carried out even with a pitch that is about 30% smaller than the conventional pitch. That is,
When the print head 13 is retracted to the large retracted position, the ribbon saving process is not possible. Processing is now possible.

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 retreated to the large retreat position when printing of one line is completed so that ribbon replacement and paper setting can be easily performed.

〔The invention's effect〕

As described above, the present invention can perform the saving process on the ribbon of the thermal transfer printer even at a print blank pitch smaller than the conventional one.

[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 a retracted position of a print head, and FIG. FIG. 5 is a diagram for explaining the approach / escape state. In the figure, 1 is a host device, 2 is a display unit, 3 is a main body, 4 is a keyboard, 5 is a thermal transfer printer, 6 is control means, 7 is a processor, 8 is a 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.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hideyuki Namba Inventor Hideyuki Namba 1015 Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Fujitsu Limited (56) References

Claims (1)

[Claims] 1. A thermal transfer printer (5) which saves ribbon by stopping ribbon feeding by retracting the print head from the print position while moving the carrier, wherein the print head is designated from the print position. Based on the print head retracting means for retracting to a position and the print data sent from the upper device (1), the length of the blank portion existing in the print line is calculated, and it is determined whether or not the ribbon can be saved and the print head is determined. A control means (6) for controlling the retracting means is provided, and if the ribbon can be saved in a blank portion existing in one line, the print head is retracted to a position with a small retracting distance, and the print head is replaced at the time of line feed and ribbon replacement. The thermal transfer printer is characterized in that the printer is retracted to a position with a large retract distance.