JPS6018362A - Transfer type thermal recording apparatus - Google Patents

Abstract

PURPOSE:To obtain a multi-color image free from color shift by holding a high speed recording capacity, by detecting the operation state of recording paper to compare the detected value with an objective value while controlling the driving of an ink donor film corresponding to the compared value. CONSTITUTION:A stepping motor 20 is driven by the pulse from a pulse oscillator 25 from a motor driving circuit 21 corresponding to a drive order 26. At this time, said pulse is output to a pulse counter 22 to store the rotation amount of the stepping motor 20. A drive roller 5 is driven by the rotation of the stepping motor 20 to convey in ink donor sheet 4 and recording paper 1 is conveyed with the advance of said film 4. In this state, a detection roller 7 is revolved and the amount of revolution thereof is transmitted to a rotary encoder 9 while the output of said encoder 9 is supplied to an operator 23 to calculate the number of pulses imparted to the stepping motor 20. Subsequently, the calculated value is supplied to a comparator 24 and pulses are output from the motor driving circuit 21 in the number corresponding to the output of the comparator 24 to control the driving of the stepping motor 20.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Application) The present invention relates to a transfer type thermal recording device, and particularly to a transfer type thermal recording device with improved color resist.

(Prior art) As a method for realizing multicolor recording using transfer type thermal recording technology, as shown in FIG.
It is known that ink donors of three colors are sequentially and periodically applied and used to sequentially perform recording with a set of recording head units.

FIG. 2 is a schematic diagram of the transfer type thermal recording apparatus in this case.

The recording paper 1 is placed between the back roller 2 and the thermal head 3.
and ink donor film 4 are fed in a superimposed manner. The ink donor film 4 is supplied from an ink donor film supply roller 13 and taken up by an ink donor film take-up roller 14 .

The thermal head 3 is supplied with both signals corresponding to the corresponding color tone (yellow Y, cyan C, or magenta M) of the ink donor film 4, so that printing is performed in the corresponding color tone.

After printing in the first color is completed, the recording paper 1 is returned to the recording starting position by, for example, separating the back roller 2 from the thermal head 3 and rotating it in the opposite direction (clockwise rotation in the example shown). Printing in the second color is performed in the same manner as described above, and thereafter, printing and recording in the third color is performed in exactly the same manner.

In this way, yellow Y1 cyan C1 magenta M
A three-color image is obtained.

However, with this method, (1) recording takes a long time because the recording paper 1 is conveyed in the opposite direction; and (2) a special ink donor film 4 as shown in FIG. 1 is used. Since this method is used, there are disadvantages such as not only the cost is high but also it is difficult to use it for medium color recording.

In order to overcome these drawbacks, a transfer type thermal recording apparatus has been proposed which is provided with three independent recording head sections for each color, as shown in FIG. In this figure, the same reference numerals as in FIG. 1 represent the same or equivalent parts.

Note that the subscripts Y, M, and C indicate that the respective parts or parts are for yellow (Y), cyan (C), and magenta (M), and the dotted lines indicate the transport path of recording paper 1. It's raining.

In the transfer type thermal recording device shown in FIG.
The drawbacks mentioned above with respect to the figures are improved, and a transfer type thermal recording device capable of high-speed recording and relatively low cost is realized.

However, in this case, since the feeding compensation or feeding speed of the recording paper 1 in each recording head section is controlled independently, even if the recording start points of each thermal head section are accurately synchronized, However, if there are variations in the feed amount or the feed speed, there is a drawback that color shift is likely to occur in the recorded image and it is difficult to achieve a high color registration of V4a.

In addition, as a method of detecting the feed amount or feed speed of the recording paper 1, it is possible to directly detect the rotation of the recording paper 1 by using a tally encoder or the like directly on the back roller 2. It is conceivable to detect it by

However, the pressure and rubber hardness of the back roller 2 are limited in order to maintain good quality of recorded images, and the pack tension and pressure are also limited in terms of rubber deformation, load, etc. , it is not only impossible to remove the slip between the recording paper 1 and the rubber hardness etc. due to changes over time, so detecting the movement of the recording paper 1 by the rotation of the back roller 2 is sufficient. The accuracy is I7
I couldn't.

(Objective) The present invention was made in order to eliminate the above-mentioned drawbacks, and its object is to maintain high-speed recording performance while maintaining high-speed recording performance.
Moreover, it is an object of the present invention to provide a transfer type thermal recording device that can realize highly accurate color regimes 1 to 1.

(Summary) In order to achieve the above object, the present invention arranges a detection roller and its pressure roller on both sides of recording paper,
The feature is that it is configured to directly and accurately measure the feed speed of recording paper.

(Example) The present invention will be described in detail below with reference to the drawings.

FIG. 4 is a side view showing essential parts of an embodiment of the present invention.

In the same figure, the symbols fF5I- in FIG. 2 refer to the same or equivalent parts.

Although FIG. 4 shows the construction of only the recording head section for one color in FIG. It is natural that they have more than one.

A recording paper 1 and an ink donor film 4 are fed between the bank roller 2 and the thermal head 3 in an overlapping manner. A binding roller 6 is pressed against the drive roller 5 with a predetermined pressure so as to sandwich the ink donor film 4 therebetween.

Further, a pressure roller 8 is pressed against the detection roller 7 with a predetermined pressure so as to sandwich the recording Kc1 therebetween. The rotary encoder 9 is mechanically connected to the detection roller 7 and outputs a signal representing each rotation thereof.

During the recording operation, for example, by a stepping motor,
When the drive roller 5 is driven, the ink donor film 4 is conveyed to the left, and at the same time, the recording paper 1 is similarly conveyed to the left by IIR.

On the other hand, since image signals are supplied to the thermal head 3 by a known appropriate method, the ink donor film 4
Selective heating and melting of the upper ink layer and transfer of the melted ink to the recording paper 1 are performed. In this way, a desired image is recorded on the recording paper 1.

During the recording operation described above, the recording paper 1 is driven in the direction of the arrow in the figure in synchronization with the ink donor film 4. As the recording paper 1 is driven, the detection roller 7 and the preprinter 11-0-roller 8 are rotated.

The detected a-rough rotation amount is converted into an electric signal by the rotary encoder 9, and based on this, the actual feed amount or feed speed of the recording paper 1 is detected.

In this case, if the recording paper 1 sag between the pressure contact position of the back roller 2 and the thermal head 3 and the pressure contact position of the detection roller 7 and the pressure roll 8, it is obvious that the recording paper 1 will become slack. It becomes impossible to accurately measure the feed port.

Such slack in the recording paper 1 is caused by the inertia of the detection roller 7, pressure roller 8, rotary encoder 9, etc., and especially occurs when the ink donor film 4 and the recording paper 1 are driven intermittently. It's easy.

Therefore, in order to effectively implement the present invention, it is desirable to eliminate the occurrence of slack in the recording paper 1 as described above.

For this purpose, it is preferable to apply a so-called pack tension to the recording paper 1 by applying a rotational load to at least one of the detection port 7 or the pressure roller 8 that is in pressure contact with the recording paper 1. A concrete example for this purpose is shown in Figure 7.

FIG. 7 is a front view showing the support structure of the pressure roller 8. In this figure, the same reference numerals as in FIG. 4 represent the same or equivalent parts.

The pressure roller 8 is rotatably supported by a support arm 11 and is pressed against the detection roller 7 . Pressing plates 34 are installed on the shaft portions at both ends of the pressure roll 8 via felts 33, and a spring 12 is installed in a compressed state between the pressing plates 34 and the support arm 11.

Therefore, the pressure roller 8 is given a rotational load of J: to the spring 12, and as a result,
Back tension is applied to recording M1.

Next, referring to FIG. 5, a recording paper 1 suitable for the present invention will be described.
The general structure and operation of the feed port or feed speed detection and control device will be explained below. In addition, in the figure, the same reference numerals as in FIG. 4 refer to the same or equivalent parts.

The stepping motor 20 is driven by output pulses from a motor drive circuit 21, which are obtained by controlling drive pulses generated by a pulse oscillator 25 in accordance with a drive command 26.

The output pulses from the motor drive circuit 21 are also supplied to a pulse counter 22 and counted there. Therefore, the pulse counter 22 includes the stepping motor 20
The amount of rotation will be stored.

On the other hand, as is clear from the explanation regarding FIG. 4, the drive roller 5 is driven by the rotation of the stepping motor 20, the ink donor film 4 is conveyed by the drive roller 5, and the recording paper 1 is similarly conveyed. Ru.

Then, the detection roller 7 is rotated by the recording paper 1,
The rotation base is transmitted to the rotary encoder 9.

Here, since the recording paper 1, the detection roller 7, and the rotary encoder 9 can be configured so that there is virtually no slip or play between them, the amount of change in the output of the rotary encoder 9 is effectively It can be seen as a representative of the actual sending mothers of No. 1.

The output of the rotary encoder 9 is supplied to a calculator 23, where the actual feed amount of the recording paper 1 is converted into a pulse value to be supplied to the stepping motor 20 assuming that there is no slip or rattle. Ru.

In other words, the calculator 23 calculates the number of pulses to be applied to the stepping motor 20 in order to convey the recording paper 1 by a distance corresponding to the amount of change in the output of the rotary encoder 9. The pulse counter 22 and the calculator 23
The outputs of are supplied to a comparator 24 and compared.

As is clear from the above explanation, the fact that the outputs of the comparators are equal (O-, that is, the outputs of the arithmetic unit 23 and the comparator 24) means that the rotation m of the stepping motor 20 is transmitted to the recording paper 1 without slipping. It means something.

Furthermore, if the output of the arithmetic unit 23 is smaller than the output of the pulse counter 22, slippage may occur between the stepping motor 20, the drive roller 5, the ink donor film 4, and the recording paper 1, causing the stepping motor 20 to rotate. This means that the amount is not completely transferred to the recording paper 1.

That is, in the latter case, the feed end of the recording paper 1 will be less than the set value. Therefore, in the present invention,
In such a case, a number of pulses corresponding to the output of the comparator 24 are additionally supplied from the motor drive circuit 21 to the stepping motor 20 to drive it, and the recording paper 1 is
Make sure to compensate for the sending mother of the child.

In addition, when supplying additional pulses to the stepping motor 20 as described above, either clear the outputs of the pulse counter 22 and the arithmetic unit 23, or subtract the count value of the pulse counter 22 by the amount of the additional pulses, or It is necessary to add an additional pulse to the output of the arithmetic unit 23 to return the comparator 24 to an equilibrium state.

As described above, the maximum feed of the recording paper 1 can be made to accurately match the setting value, so similar feed amount control can be performed for the recording head sections for each color tone, and the pulse oscillator 25 can be shared. By doing so, it is possible to accurately match the maximum feed of the recording paper 1 for each recording head section for each color, and it is possible to realize highly accurate color registration.

Moreover, if the above-mentioned feed rate control is performed in an extremely short cycle, the feed speeds can be matched, and a color resist with even higher viscosity can be achieved.

FIG. 6 is a schematic block diagram showing another example of a detection and control device for the feed amount or feed speed of the recording paper 1 suitable for the present invention. In addition, in the figure, the same reference numerals as in FIG. 5 represent the same or equivalent parts.

As is clear from the comparison with FIG. 5, in example C, the pulse counter 22 in FIG. 5 is replaced with a function generator 28, and the function generator 28 is activated by the drive command 26. .

The function generator 28 uses the elapsed time from the start of recording as a parameter to generate an electric signal representing the number of pulses to be supplied to the stepping motor 20 at that time (therefore, the amount of feed of the recording paper 1).

That is, the output of the function generator 28 corresponds to the target value of the feed base of the recording paper 1, while the output of the arithmetic unit 23 represents the actual feed value of the recording paper 1, as explained with reference to FIG. ing.

Therefore, as is clear, the comparison between the two is performed using the comparator 24.
If this is done and the motor drive circuit 21 is controlled according to the result, the actual feed amount of the recording paper 1 will be equal to the target value.

Therefore, if the function generator 28 is set equally for each color tone recording head, a multicolor image with no color shift, that is, with extremely high color registration accuracy, can be obtained.

(Effects) As is clear from the above description, according to the present invention, the following effects are achieved.

(1) Since the feed amount or feed speed of the recording paper can be accurately detected and controlled for each recording head section for each color tone, a multicolor image without color shift can be obtained.

(2) Conventional 1+ in Figure 3:? Since the configuration and recording method can be applied as is, the recording speed can be maintained high.

[Brief explanation of the drawing]

FIGS. 1 and 2 are schematic diagrams showing the configuration of an ink donor film A3 and a transfer type thermal recording device for performing multicolor recording with a single thermal head, respectively, and FIG. FIG. 4 is a side view showing the essential parts of an embodiment of the present invention, and FIGS. FIG. 7 is a schematic block diagram of a recording paper feed interval or feed speed detection and control device suitable for
FIG. 2 is a front view showing an example of a one-stop device for applying back tension to recording paper in the figure. DESCRIPTION OF SYMBOLS 1...Recording paper, 2...Back roller, 3...Remal head, 4...Ink donor film, 5...
...Drive roller, 6...Pinch roller, 7...
Detection roller, 8... Pressure roller, 9... Rotary encoder, 20... Stepping motor,
21... Motor drive circuit, 22... Pulse counter, 23... Arithmetic unit, 24... Comparator, 25... Pulse oscillator, 26... Drive command, 28... Function generator Representative patent attorney Michito Hiraki and 1 other person

Claims (2)

[Claims] (1) A plurality of thermal heads arranged in series, each consisting of a thermal head, a back roller press-contacted to the thermal head so as to sandwich the recording paper and an ink donor film, and a means for driving the ink donor film. In a transfer-type thermal recording apparatus, the recording paper has a pair of recording head units, and a means for feeding the recording paper between the back roller of each recording head unit and the thermal head while superimposing the recording paper on an ink donor film. means for detecting the running state of the vehicle by contacting it, and the output of the detection means described in 11a,
A transfer type thermal recording apparatus, comprising: means for comparing the running state of the recording paper with a target value; and means for controlling the driving means for the ink donor film in accordance with the output of the comparing means. (2) A patented recording apparatus characterized in that a rotational load is applied to the recording paper running state detection means, thereby applying pack tension to the recording paper.