JPH0358308B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a transfer type thermal recording device, and more particularly to a color transfer device comprising a line thermal head, an ink donor film corresponding to the line thermal head, and a back roller. A multicolor transfer type that has thermal recording sections for two or more colors, and each recording section independently transfers image information of the color, and records a multicolor original by superimposing the transferred image information of each color. This invention relates to a thermal recording device.

[Prior art]

FIG. 1 is a schematic diagram conceptually showing an example of the configuration of a conventional multicolor transfer type thermal recording device. The device includes a line thermal head 10, a back roller 11, and a black ink donor film (hereinafter referred to as black IDF) 1.
2. A black transfer thermal recording unit 100 consisting of a supply roller 13, a take-up roller 14 and a drive roller 15 of the black IDF 12, a line thermal head 20, a back roller 21, a red ink donor film (hereinafter referred to as red IDF) 22, and the red ink donor film (hereinafter referred to as red IDF) 22. IDF2
This is a two-color transfer type thermal recording device having a red transfer thermal recording section 200 consisting of two supply rollers 23, a take-up roller 24, and a drive roller 25. The line thermal heads 10 and 20 are connected to respective pressure contact mechanisms (not shown), and when recording starts, the black IDF 12 and the red IDF 2 are connected.
2 to the back roller 11 and the back roller 21.

At the same time, the black IDF12 and the red IDF
22 transport has also started and the black IDF12 and red
The IDF 22 is transported between the line thermal head 10 and the back roller 11 and between the line thermal head 20 and the back roller 21 of each recording section, and is sequentially wound up from the respective supply rollers 13 and 23 to the winding rollers 14 and 24. On the other hand, a recording paper P is supplied from a recording paper supply mechanism (not shown).
When the conveyance of the black color starts, the black color of the black recording section
It is supplied between the IDF 12 and the back crawler 12. Thereafter, the recording paper P is conveyed between the black IDF 12 and the back roller 11 in synchronization with and in close contact with the black IDF 12 that has been conveyed in advance as described above. At this time, the recording paper P is covered with the black IDF 1, which is melted at the required heat generation location of the thermal head 10, which is selectively driven according to the black image information of the predetermined original.
Ink No. 2 is transferred, and only black image information is recorded first. The recording paper P on which this black image information has been recorded is then transferred to the red IDF of the red recording section 200.
22 and the back roller 21, and is conveyed here as well in close contact with and in synchronization with the red IDF 22, which has been conveyed in advance like the black recording section 100.

At this time, the molten ink of the red IDF 22 is transferred, which is melted at a required heat generation location of the thermal head 20, which is selectively driven in accordance with the red image information of the predetermined original. Therefore, black and red two-color image information is recorded on the recording paper P by combining the previously transferred black image information and the red image information, and then the paper is ejected to a paper ejection tray (not shown). Ru. In this way, a plurality of transfer heat-sensitive recording sections of different colors are arranged in series, and while the same recording paper is sequentially conveyed through each recording section, different color inks are transferred independently, and these transfer inks are overlapped. In a multicolor transfer type thermal recording device that records a multicolor original by alignment, it is particularly important to accurately align the transfer position of the melted ink in each recording section in order to maintain good recording quality. . However, according to the conventional apparatus described above, since the recording paper is conveyed by friction with the ink donor film of each recording section, the amount of conveyance of the ink donor film of each recording section is different from that of each drive roller and each IDF.
If there is a slight difference in the diameter of the supply roller during the manufacturing process, dirt conditions, printing density, etc., the conveyance amount of the recording paper at each recording section will also be different values, so the ink of each color will vary. There was a drawback that the transfer position of the image was shifted, and the recording quality at this time was significantly impaired.

[Purpose of the invention]

The present invention has been made in order to eliminate the above-mentioned drawbacks, and even when there is a difference in the conveyance amount of recording paper in each recording section due to the above-mentioned factors, the positional deviation of the transfer ink of each color can be corrected, and the present invention is always satisfactory. The object of the present invention is to provide a multicolor transfer type thermal recording device that can obtain recorded images of high quality.

[Structure of the invention]

Therefore, in the present invention, the back rollers of each recording section are rotated as the recording paper is transported, and the load on the back rollers is small, and the back rollers are transported with little slippage with the recording paper, so that the amount of transport of both of them is equal to each other. A means for detecting the rotation angle of each of the back rollers is provided, and the amount of conveyance of the recording paper in each of the recording sections is detected from the detection value of the detection means, and the amount of conveyance of the recording paper in the recording section is used as a reference. If the conveyance amount or the conveyance amount with other recording units is increased by one line, that is, the minimum feed amount of the recording paper, the logical sum of the image information of the next two lines is calculated.
When printing as a line and the number decreases, image information of the previous line or the next line is inserted and printed to pseudo match the recording paper feed amount in each recording section, and the transfer ink described above is I am trying to correct the positional deviation.

[Embodiments of the invention]

Embodiments of the present invention will be described in detail below based on the accompanying drawings. First, the multicolor transfer type thermal recording device of the present invention has the shafts of the cross rollers 11 and 21 of the black recording section 100 and the red recording section 200 of the conventional apparatus shown in FIG. It is constructed by attaching angle detectors 31 and 32. The back crawler rotation angle detector 3
As 1 and 32, well-known incremental shaft encoders can be used. This incremental shaft encoder consists of a rotary plate 33 in which transparent parts and opaque parts are formed with uniform pitch, and light emitting elements 3 arranged facing each other with the circuit board 33 in between.
4 and a light receiving element 36.
3 rotates with the rotation of each of the back rollers 11 and 21, and the light emitted from the light emitting element 34 is received by the light receiving element 36 via the rotary plate 33 and the slit plate 35.
As a result of the output, a pulse train as shown in FIG.

Therefore, in the present invention, the number of pulses is counted, the rotation angle of each of the back rollers 11 and 21 is detected from the counted value, and the recording paper P is fed from the rotation angle in synchronization with the rotation of the back rollers 11 and 21. I am trying to calculate the amount. By the way, the back crawler rotation angle detector 31,
32 is the detector 31, 32 for the reason mentioned above.
The back rollers 11 and 21 to which the back rollers 11 and 21 are attached have a resolution capable of detecting rotation angles equal to or less than the minimum reference feed amount of one line of the recording paper P. For example, if the standard feed amount is 1/12 mm and the diameter of the cross roller is 25 mm (that is, the circumference of the cross roller is 25πmm), the following formula is used: 1/12:25π=θ:360° to θ=0.38° or less. Rotating plate 3 that can be detected
Select 3. Therefore, at this time, the resolution of the back crawler rotation angle detector is 948 (=360°÷0.38°) [pulses/rotation] or more. FIG. 3 is a block diagram showing a schematic configuration of a transfer ink position deviation correction control circuit in, for example, the black recording section 100 of the apparatus of the present invention, and its operation will be described below.

First, the drive control unit 4 is activated by the operator's recording start operation.
Control pulses for driving the drive roller 15 are sent from the drive roller drive circuit 42 from the drive roller drive circuit 42 . The drive roller drive circuit 42 receiving the control pulse sends a drive pulse to the step motor 150 that drives the drive roller 15, thereby driving the step motor 150 and causing the drive roller 15 to rotate. Black IDF12
transportation will begin. At the same time, the recording paper supply mechanism starts transporting the recording paper P.
The toner is first supplied between the IDF 12 and the back roller 11 of the black recording section 100, and is then conveyed between the recording sections by the frictional force with the IDF 12, which has been conveyed in advance, as described above. By the way, the drive control section 41
The control pulses applied to the drive roller driving circuit 42 are simultaneously applied to the counter _C0 , and the number of pulses is counted. The count value is then added to the paper feed amount calculation circuit 42, and the number of pulses is determined by a predetermined calculation.
The reference recording paper feed amount to be fed by the back roller 15 which is rotated when the paper is added to the back roller 15 is calculated, and the calculated value is further added to the comparator 45. On the other hand, the rotation angle detector 31 of the back roller 11, which rotates as the IDF 12 and the recording paper P are transported by the above-described method, detects a signal as shown in FIG. 3b according to the rotation of the back roller 11. A pulse train is generated and the pulse train is sent to a counter _C1 for counting. The count value by this counter _C1 is then added to the paper feed amount calculation circuit 44. Then, the rotation angle of the back roller 11 is converted into the actual feed amount of the recording paper P, and the converted value is also added to the comparator 45 as described above. Here, the comparator 45 calculates the actual feed amount of the recording paper P in the black recording section 100 calculated by the paper feed amount calculation circuit 44 and the paper feed amount calculation circuit 43 added in advance. A comparison is made with the standard feed amount determined, and it is detected whether there is a difference between these two feed amounts by the minimum feed amount of the recording paper P in the sub-scanning direction, that is, in this device, a feed amount difference of 1/12 mm. do.
As a result of this detection, when the actual feed amount is greater than the reference feed amount by the above-mentioned minimum feed amount of the recording paper P, a signal to reduce, for example, one line of image information is sent to the thermal head drive control section 46. The image signal control section of the thermal head drive control section 46 uses this reduction signal to control the black recording section 100.
The next line of image information to be added to the line thermal head 10 and the next line of image information to be added to the next line thermal head 10.
The image information of the line is logically summed with the image information of the line, and the image information of these two lines is added to the line thermal head 10 as one line to print one line of the image information. If this printing operation is viewed from the side of the recording paper P, the feed amount is reduced by one line, and as a result, the feed amount of the recording paper P pseudo-coincides with the reference feed amount. Further, when the comparison result by the comparator 45 shows that the actual recording paper feed amount is less than the reference feed amount by one line, that is, 1/12 mm, the comparator 45 outputs a signal to the thermal head drive control section 46. For example, an additional signal for one line of the image signal is sent out.
In response to this additional signal, the image signal control section of the thermal head drive control section sends out the image information of the previous line printed to the line thermal head 10 or the image information of the next line to be printed. Executes printing one more line.

Therefore, similarly to the above, when this printing operation is viewed from the side of the recording paper P, the feed amount is increased by one line, and here too, the feed amount of the recording paper P matches the reference feed amount. By controlling the image information supply as described above, the black recording section 1
The feed amount of the recording paper P in 00 can be kept at the reference feed amount at all times in a pseudo manner. Therefore, by configuring the transfer ink position deviation correction control circuit as described above in the red recording section 200 and performing similar control, the paper feed amount of the red recording section 200 can also be corrected to the reference feed amount. Because of this, the recording paper feed amount in both the recording sections is the same, and the transfer deviation of the black and red ink transferred after passing through both the recording sections can be significantly reduced. In this embodiment, a method has been described in which the actual recording paper feed amount of each recording unit is compared with the reference paper feed amount and the image information is controlled so as to correct the actual paper feed amount to the reference feed amount. The same effect as described above can be expected by a method of comparing the actual feed amounts between sets and controlling the image information to compensate for the difference between the two. It goes without saying that the present invention can be applied not only to the above-mentioned two-color recording device but also to a multi-color transfer type thermal recording device.

〔Effect of the invention〕

As explained above, according to the multicolor transfer type thermal recording apparatus of the present invention, the feed amount of the recording paper of each recording section is calculated from the rotation angle of the back roller of each recording section, and the feed amount is calculated based on the feed amount and the reference feed amount. Or, when the feed amount increases or decreases by the minimum feed amount of the recording paper compared to the feed amount of other recording sections, one line of image information to be added to the line thermal head of the corresponding recording section is respectively reduced or inserted. Since the printing is carried out in such a manner that even if the feeding amount of the recording paper in each recording section is different, the positional deviation of the transfer ink of each color can be corrected and a recorded image with good print quality can always be obtained. It has excellent effects.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram showing the configuration of each recording section in a conventional two-color transfer type thermal recording device, and Fig. 2 a and b
is a schematic diagram showing the schematic configuration of the back crawler rotation angle detector of each recording section of the device of the present invention and its output pulses,
FIG. 3 is a partial schematic diagram of a transfer ink positional deviation correction control circuit showing an embodiment of the present invention. 10, 20... line thermal head, 11,
21... Cross roller, 12... Black ink donor film, 22... Red ink donor film, 15, 25... Ink donor film drive roller, 31, 32... Cross crawler rotation angle detector, 41... Drive control unit, 42...Drive roller drive circuit, 43, 44...Paper feed amount calculation circuit, 45...Comparator, 46...Thermal head drive circuit section.

Claims (1)

[Claims] 1. An ordinary recording paper and an ink donor film coated with heat-fusible or heat-sublimable ink are superimposed, and a back roller is used to press them against a line thermal head, and image information is transferred from the line thermal head. In a multi-color transfer type thermal recording device comprising at least two color recording sections that melt ink and perform color transfer recording on the recording paper with thermal energy selectively supplied according to the rotation angle of a back roller of each recording section, a means for detecting, and a means for calculating the feed amount of the recording paper conveyed through the recording section from the detection value of the detection means, and determining whether the feed amount of the recording paper is a preset reference feed amount or each of the recording sections. If the minimum feed amount of the recording paper in the sub-scanning direction is greater than the feed amount based on any one of the following, the logical sum of the image information of the next two lines is calculated. Based on the logical sum, the image information of the two lines is printed as one line, and if the amount is decreased by the minimum feed amount, the image information of the previous one line or the image information of the next one line is inserted and printed. 1. A multicolor transfer type thermal recording device comprising a thermal head drive control means for controlling a thermal head.