JPS6176380A - Heat transfer printer - Google Patents

Abstract

PURPOSE:To enable to increase printing speed while a high quality printing is being continued by having a period in which an electrical application time to dots to print from now on is to be made longer be set within an electric application time for a dot printing which could be stepped up or delayed. CONSTITUTION:A heat element of a thermal head 1 of which an ink ribbon 2 is being pressed to a paper 3 to be transferred is applied with electricity and heated, and a solid ink on the ink ribbon 2 is partially fused onto the paper 3 to be transferred and printing is carried out. Regardless of shifting of a timing of print to be stepped up or delayed from the normal timing, the printing dots to be shifted remains continuous, resulting in an operation during an electrical application time for printing. For the dots to be printed with a normal printing timing, in connection with the printing dots in case the previous printing data was '0' (no record) and the printing data for this time is '1' (recorded) the electrical application time is extended (a balancing is provided between the thermal energy of dots of no previous printing and other dots to increase printing quality) and the timing is varied to be accelerated or delayed to be placed in the electrical application time for dot printing, resulting in reduction of overall printing time to be able to increase a printing speed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a thermal transfer printer or thermal printer, and particularly to a serial type thermal transfer printer or thermal printer in which the thermal head moves at a high speed during printing.

[Background of the invention]

In the case of thermal transfer printers or thermal printers, the thermal head is moved relative to the ink ribbon or thermal paper to increase speed. Especially in serial type thermal transfer printers or thermal printers, the thermal head moves at a high speed during printing, so the thermal head moves at almost the same speed during printing.

For this reason, the printed dots have a shape that is elongated in the direction of movement of the thermal head, deteriorating print quality and becoming a factor that prevents speeding up of serial type thermal transfer printers or summar printers.

For printing dot-shaped pastures, the width of the thermal element on the thermal head in the direction of movement of the thermal head should be made smaller than the width in the direction perpendicular to the direction of movement, as shown in Japanese Utility Model Application No. 51-73045. Alternatively, a method has been proposed in which the shape of the printed dots is made closer to the positive direction.

However, this method has the following drawbacks.

(1) Since the applied power per unit area of the thermal element increases, the pulse withstand life decreases.

(2) In a normal wiring structure in which the electrodes for energizing the thermal element are pulled out laterally (in the direction of movement of the thermal head), the resistance value of the thermal element decreases, which increases the conduction current and increases the burden on the drive element. However, the voltage drop due to the common impedance also increases, which adversely affects printing quality.

(3) As a countermeasure in the previous section, if the thermal element film thickness is made thinner in order to increase the thermal element resistance value, the pulse resistance life will be reduced, and if the specific resistance of the material is increased, the degree of freedom in material selection will be severely restricted.

[Purpose of the invention]

An object of the present invention is to provide an Am photo printer that can increase printing speed while maintaining high print quality by using a conventional thermal head without using the above-mentioned method.

[Summary of the invention]

The cause of print quality deterioration is the horizontally elongated print dot shape, but the problems that occur when characters are actually printed are the vertical and horizontal imbalance of the kanji characters and the collapse between vertical lines.

Normally, kanji fonts of 24 x 24 dots or larger are designed with two dot rows for vertical lines and one dot row for horizontal lines, so the above-mentioned print quality deterioration can be solved by improving the print dot shape itself. Even if the overall width of the two dots is compressed, there is still a sufficient effective improvement effect.

In order to compress the entire width of successive dots and perform corrections to maintain high print quality, and to further increase printing speed, the present invention adopts the method described below.

In other words, even if the printing timing of the subsequent dot or the last dot is earlier than the normal printing timing,
Even when the printing timing of the preceding dot or the first dot is delayed from the normal printing timing, since the printing dots shifted earlier or later are consecutive dots, only the printing energization time is performed. For the dots printed at the normal printing timing, the energization time is applied to the dots printed when the previous print data is "O" (no record) and the current print data is "1" (record A). As shown in Figure 2, the timing of increasing the printing time (improving printing quality by equalizing the thermal energy of the dots that were not printed last time and other dots) is shown in Figure 2. By doing so, it is possible to shorten the overall printing time and increase the printing speed by the reduced time.

[Implementation sequence of the invention]

Hereinafter, one embodiment of the invention will be described with reference to FIGS. 1 to 8.

FIG. 3 is a configuration diagram of a thermal transfer printer to which the present invention is applied, in which 1 is a thermal head, 2 is a thermal transfer ink ribbon, and 3 is a thermal transfer ink ribbon.
is the transfer paper, and the thermal head 1 is the ink ribbon 2.
The thermal element on the thermal head 1 is heated with electricity while it is pressed against the transfer paper 3, and the heat partially melts the solid ink coated on the ink ribbon 2, causing the transfer paper 3 to melt.
Printing is performed by transferring the image to

The ink ribbon 2 is housed in a ribbon cassette 4, and the thermal head 1 and ribbon cassette 4 are housed in a carriage 5.
The carriage 5 is removably attached to the top and is movable left and right along a slide shaft 6, and the CD motor 7 reciprocates the carriage 5 left and right via a timing belt 8.

Inside the carriage 5, in addition to the ribbon sensor 10, there are a head traction mechanism that presses the thermal head 1 against the platen 9 side, an ink ribbon take-up mechanism, and a skip mechanism that stops winding of the ink ribbon when the thermal head is not pressed. It is stored.

On the other hand, a paper feed roller on the lower side of the platen 9 presses the transfer paper 3 against the platen, and as the LF motor 11 rotates the platen 9 via a gear, the transfer paper 3 is fed by frictional force. .

12 is the platen 9t - platen knob for manual rotation, 13 is the paper presser row? 14i This is a release lever for manual operation.

Further, 15 is a home position sensor that determines the reference position of the carriage 5, 16 is a paper sensor, 1.7 is a control unit, and 18 is a control unit 17 and electrical parts attached to the carriage 5 that moves left and right. This is a flexible circuit board that continues to be used.

FIG. 4 is a block diagram showing the configuration of the control unit 17 and electrical components. The control unit 17 includes a main control board 21, an operation panel 22, a power transformer 23, and a power switch.
It is composed of a C circuit board 24. 25 is an interface 7/8 input/output, and 26 is an AC power input. Further, 19 is a traction solenoid that is a power source for the head traction mechanism, and 20 is a skip solenoid that is a power source for a skip mechanism. The ribbon winding mechanism uses relative movement between the carriage 5 and one side of the timing belt 90 as a power source.

FIG. 5 is a configuration diagram of the thermal head 1. 27 is a heat sink, 28 is a ceramic substrate, and 29 is a flexible substrate.
9 are connected by a plug portion 30, and both are glued onto the heat sink 27. 31 is a plug for external connection. Further, 32 is a thermistor for detecting the temperature of the heat sink 27, which is bonded onto the heat sink 27.

On the other hand, a thin heat resistance glass is placed on the ceramic substrate 28! (
Four rows of glaze layers (hereinafter referred to as glaze layers) are formed, and rows of thermal elements 39A and 39B of thin film resistors are formed on the central glaze layers 37A and 37B. Glaze layer 3 on both ends
5.36 is a dummy for ensuring contact stability between the thermal head 1 and the ink ribbon 2.

The fc33h and fc33B are driver ICs for driving the thermal element arrays 39A and 39Bf, and the circuit configuration is as shown in FIG.

FIG. 6 is a circuit configuration diagram of the thermal element array 39A and the driver IC 33A, and since the circuit configurations of the thermal element array 39B and the driver IC 33B are completely the same, their explanation will be omitted here.

In FIG. 6, 41A is a 24-pit shift register;
46 is a transfer data signal, 47A is a transfer lock signal, and print data for one column is serially transferred from the control unit and stored. Also, 42 Al~42m 24 is a latch, 44A is an inverter, 48A is a launch signal, and
Print data after transfer is lunch signal and lunch 42 people 1 to 4
2 Loaded into A24.

43 people 1 to 43A24 are NAND gates, and the output stage is connected to the thermal element 40 At-40A24,
Direct switching of current to the thermal element. 45A is an inverter, 49A is a strobe signal that controls the time for energization to the thermal element, and the energization to the thermal element is controlled by the AND condition of the print data stored in the latches 42A1 to 42 and the strobe signal 49. . 50 is a thermal element drive power input.

FIG. 7 is an enlarged view of the vicinity of the thermal element rows 39A and 39B.
51 is a common electrode connected to the thermal element drive power input 50A, 5.2A and 52B are driver ICs 33A and 3, respectively.
These are individual electrodes connected to the output stage of 3B.

FIG. 8 is a No. 1 waveform diagram showing the control timing of the thermal head 1, and 53 is the CD motor 7 in the main control board.
'f is a timing signal generated for driving,
One column (24 dots vertically x 1 dot horizontally) is printed in response to this signal.

There are two thermal element rows, 39A and 39B, one of which is an even numbered row,
The other one is responsible for printing odd-numbered columns, and energization is performed alternately. Therefore, one line of printing is divided into three modes for each υ dot depending on whether or not there was printing before the previous one and whether or not there was printing last time. This mo41. I-5 mode selection is performed using the algorithm shown in FIG.

57A is print data that should be energized during the Txl period,
58A and 59A are correction data or print data that should be energized during Ty and Txz periods, respectively, p54A to 56.
A shows the current waveforms in the three modes described above.

As shown in Figure 2, this is a t! of horizontally continuous dots! In printing control that narrows the width of Kl, the printing time for the entire length of TYl shown in FIG. 1 can be shortened, and the printing speed can be increased by the reduced time.

In addition, the temperature offset correction for consecutive printing tons (K) is omitted because the number of dots is Xi. Temperature offset correction is performed for the dots that are not printed both in the previous printing (previous time for one thermal element) and in the previous □ printing. Print quality is guaranteed.

〔Effect of the invention〕

According to the present invention, it is possible to solve the basic problem of the high-speed serial thermal transfer printer I77 printer, which is the unbalance of the vertical and horizontal line widths of printing, and to improve the printing speed while maintaining the printing quality. Improvements can be made. Conversely, if the printing quality is fixed, even higher speeds can be achieved.

Furthermore, since the content of the present invention is an improvement in the control software of the thermal head, the design conditions of the thermal head can be relaxed by applying the present invention, which is effective in reducing the cost of the thermal head and improving the reliability. be.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the energization time for one dot row in a thermal transfer printer before the present invention is applied, Fig. 2 is a diagram illustrating the energization time when the present invention is applied, and Fig. 3 is the configuration of the thermal transfer printer. 4 is a control system configuration diagram, FIG. 5 is a configuration diagram of the thermal head 1, FIG. 6 is a circuit configuration diagram of the thermal element array 39A and driver IC 33A, and FIG. 7 is a thermal element array 39A,
8 is a signal waveform diagram for controlling the thermal head 1, and FIG. 9 is a diagram showing a printing mode selection algorithm. 39A, 39B... thermal element row, 1... thermal head, 2... ink ribbon, 5... carriage, 7...
...CD motor, 19...Traction Lenoid,
33A. 33B... Driver IC, 21... Main control board.

Claims (1)

[Claims] 1. A thermal head having a plurality of thermal elements arranged in a row, a head pressing means for bringing the thermal elements into close contact with the ink ribbon or thermal paper, and a thermal head in a direction intersecting the thermal element row with respect to the ink ribbon or thermal paper. The thermal head and the ink ribbon or the thermal paper in a thermal transfer printer comprising a conveying means for moving the thermal head and the ink ribbon or the thermal paper relative to each other, and a means for selectively energizing and driving the plurality of thermal elements in synchronization with the relative movement between the thermal head and the ink ribbon or the thermal paper. When printing consecutive dots in the direction of relative movement with In the printing control to be made slower, a period for lengthening the energization time for the dots printed at the normal printing timing that were not printed last time but are printed this time is performed during the printing energization time of the printing dots that are shifted earlier or later. A thermal transfer printer characterized by: