JPH0653431B2 - 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 printing line, the lower the printing speed is, By utilizing the fact that the length of the blank portion that enables ribbon saving is short, whether or not the ribbon saving process is possible is determined for the length of the blank portion according to the printing speed.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a serial thermal transfer printer that winds a ribbon while printing, and in particular, with respect to a blank portion existing in a print line, it is determined whether or not the print head can be retracted based on the print speed. However, the present invention relates to a thermal transfer printer that performs ribbon saving processing even for the length of a blank portion that is not executed during high speed printing during low speed printing.

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 feed 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 an 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.

The ribbon cassette 20 is mounted on the carrier 25 and has a cutout portion into which the print head 22 is inserted. 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 in the approach state. Is pulled out from the ribbon cassette 20 by the print head 21 and comes into close contact with 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 occur at the position indicated by the diagonal lines in Fig. 4, and the ribbon will be consumed, but it will wind up before printing. The part taken 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.

In this way, when saving the ribbon while traveling the carrier, the length of the blank portion that is not printed in one line is such that the carrier moves during the total time required for the escape and the time required for the approach. It must be at least the pitch.

Therefore, when the printing speed is high, that is, when the moving speed of the carrier is high, the escape of the print head + the approach time is constant, and therefore the length of the blank portion where the ribbon cannot be saved is naturally the printing speed. Is faster than that with slower printing speed.

By the way, even in thermal transfer printers, multiple printing is possible due to draft printing (printing with thinned dots to increase printing speed), regular printing (printing without thinning dots), or rough paper (paper with a rough surface). Some have speed.

In this thermal transfer printer having a plurality of printing speeds, the ribbon is saved by retracting the print head based on the length of the blank portion that can be saved during high-speed printing.

[Problems to be solved by the invention]

As described above, conventionally, the ribbon saving condition is set based on the length of the blank portion in one line where there is no printing, which can be saved in the case of high-speed printing. Therefore, it can be saved in the case of low-speed printing. There is a problem that the ribbon saving efficiency is poor because the ribbon saving process is not performed even if the length is the blank portion.

In view of such a problem, the present invention determines the length of a blank portion where ribbon saving can be performed corresponding to the printing speed, determines whether or not ribbon saving processing is possible for each printing speed, and saves as much ribbon as possible. The processing is carried out.

[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, and 6 detects the length of a blank portion where characters are not printed for each print line from print data sent by the higher-level device 1,
It is a control unit that determines whether or not the print head can be withdrawn according to the print speed.

The control means 6 of the thermal transfer printer 5 calculates the length of the blank portion, that is, the pitch, which is not printed for each printing, from the print data sent from the host device 1, and saves the ribbon from the escape + approach time corresponding to the printing speed. When it is possible,
The print head is escaped at each print speed.

[Action]

With the above configuration, when the thermal transfer printer receives the print data sent from the host device, it detects the blank area where printing is not specified from the print data for one line and checks its pitch to determine the print speed and print head escape. From the + approach time, it is possible to calculate the moving distance of the print head and determine whether ribbon saving processing is possible.

〔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 stores the print data in one line in the RAM 11 and also calculates the length of the blank portion, that is, the pitch, from the print data for one line and stores it in the RAM 11. To do.

The processor 7 drives the pulse motor 19 through 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. Reads the pattern and print head control circuit 1
Then, it is sent to the print head 13 via 2 and the heating element is heated to transfer the ink of the ribbon onto the paper.

At the same time, the space motor 17 is passed through the space control circuit 16.
Is driven 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 checks the pitch of the blank portion calculated and stored in the RAM 11 in advance, and the carrier, that is, the print head 1 during the escape + approach time determined by the print speed.
When there is a ribbon saving pitch from the moving distance of 3, the pulse motor 19 is driven through the approach / escape control circuit 18 and the print head 13 is retracted when the blank portion is reached.

FIG. 3 is a diagram for explaining a ribbon saving state.

The shaded area indicated by means of printing is a range where printing is performed in one line, and the area shown by means of printing is a range where printing is not performed. The thermal transfer printer is, for example, 40 CPS (4
The printing speed of 0 character / second) and 80 CPS (80 character / second) can be switched and executed.

FIG. 3 (a) shows a case where the ribbon saving is not performed. The range of the blank portion where printing is not performed is narrow, and even at the printing speed of 40 CPS, the print head 13 is escaped at the end of the range of Indicates that it is impossible to approach at the beginning.

In this embodiment, the range of this blank part is less than 9 characters.

In FIG. 3 (b), if the blank portion length is 40 CPS and the printing speed is 40 CPS, the print head 13 can be escaped at the end of the range and approached at the beginning of the range, so ribbon saving processing can be performed. However, at the printing speed of 80 CPS, the approach cannot be made in time and the ribbon saving process is impossible.

In this embodiment, the range of this blank part is 9 characters or more and 18
It is less than letters.

In Fig. 3 (c), the length of the blank part is 40CPS and 80C.
The case where ribbon saving processing is possible for all PS is shown.

In this embodiment, the length of this blank portion is 18 characters or more.

The processor 7 determines the condition of FIG. 3 and executes the retracting process of the print head 13 as described above.

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 retracted position, and then drives the line feed motor 15 via the line feed control circuit 14. And feed the paper.

〔The invention's effect〕

As described above, the present invention can perform ribbon saving processing according to the processing speed for a ribbon of a thermal transfer printer that prints by switching a plurality of printing speeds.

[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 ribbon saving state, and FIG. 4 is a state of using a ribbon. 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 a RAM, 12 is a print head control circuit, 13, 21 and 22 are print heads, 14 is a line feed control circuit, 15 is a line feed motor, 16 is a space control circuit, 17 is a space motor, 18 is an 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 having a print head and a ribbon cassette mounted thereon is moved along a platen at a speed corresponding to each of a plurality of printing speeds, and ribbon feeding is performed at a speed corresponding to the moving speed. The recording medium inserted between the ribbon and the ribbon is set to the printing position by performing an approach operation of pressing the print head through the ribbon, and printing is performed by heating the heating element of the print head. A thermal transfer printer (5) that performs an escape operation to retract the print head from the printing position, separates the ribbon from the recording medium, and stops the ribbon feeding, and print data sent by the host device (1). Based on, detect the length of the blank part that is not printed in one line,
The control means (6) is provided to judge whether or not the print head performs the escape and approach operations based on the preset print speed and the fixed time required for the approach and escape operations, and the print speed slows down. The thermal transfer printer is characterized in that the length of the blank portion in the one line for executing the escape and approach operations of the print head is shortened.