JPS6410981B2 - - 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 multi-color transfer type thermosensitive device that has thermal recording sections for two or more colors, and each recording section independently transfers image information for each color, and records a multicolor original by combining the transferred image information for each color. It relates to a 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 section 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, and a red ink donor film (hereinafter referred to as red IDF) 22.
A red transfer thermal recording section 2 consisting of a supply roller 23, a take-up roller 24, and a drive roller 25.
This is a two-color transfer type heat-sensitive recording device having 00.
The line thermal heads 10 and 20 are connected to a pressing mechanism (not shown), and are pressed against the back roller 11 and the back roller 21 via the black IDF 12 and the red IDF 22 at the start of recording.

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 11. 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, 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). In this way, a plurality of transfer heat-sensitive recording sections of different colors are arranged in series, and each recording section sequentially conveys the same recording paper while independently transferring different colors, and also using a combination of these transfer inks. Therefore, in order to maintain good recording quality in a multicolor transfer type thermal recording apparatus that records a multicolor document, it is particularly important to prevent the transfer position of the melted ink in each recording section from shifting. However, according to the above-mentioned conventional apparatus, the conveyance speed of the ink donor film of each recording section is affected by the conveyance of the recording paper due to minute differences in diameter in the manufacturing process of each drive roller, dirt conditions, or differences in the diameter of the IDF supply roller. Alternatively, it easily varies depending on the recording density, etc., and as a result, the conveyance amount of the recording paper differs between each recording section, resulting in misalignment of the transfer position of each color ink, which significantly impairs the recording quality.

[Purpose of the invention]

The present invention has been made to eliminate the above-mentioned drawbacks, and even when the conveyance amount of the recording paper in each recording section differs due to the above-mentioned factors, the transfer position shift of each color ink 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, each guide roller is newly arranged in a specific passage path of the recording paper of each recording unit, and rotates in accordance with the movement of the recording paper conveyed through each recording unit, and furthermore, each of these guide rollers is Each guide roller rotation angle detector capable of detecting the rotation angle of the guide roller with a rotation angle accuracy corresponding to the minimum feed amount of the recording paper in the sub-scanning direction is provided on the rotating shaft, and each guide roller rotation angle detector detects the rotation angle of the guide roller. The feed amount of the recording paper in each recording unit is calculated from the value, and the feed amount is compared with a preset standard feed amount or the feed amount when another recording unit is used as a reference. The position of the transfer ink in each recording section is determined by deleting or inserting one line of image information to be added to the line thermal head of the recording section when the transfer ink increases or decreases by the minimum feed amount in the sub-scanning direction. The discrepancy is corrected to maintain good recording quality.

[Embodiments of the Invention] Hereinafter, embodiments of the present invention will be described in detail based on the accompanying drawings. FIG. 2 is a schematic configuration diagram of a multicolor transfer type thermal recording device showing one embodiment of the present invention.
Components that perform the same functions as those of the conventional device shown in the figure are designated by the same reference numerals. The apparatus of the present invention includes a thermal head 10 and a back roller 11 for each of the black recording sections 100 and 200.
In the recording paper passing path immediately before the thermal head 20 and the back roller 21, there is a guide roller consisting of a pair of rollers that are in contact with each other so as to sandwich the recording paper P in a direction perpendicular to the conveyance direction of the recording paper P. 30 and 40 are newly installed.
The guide rollers 30 and 40 are arranged to rotate in accordance with the movement of the recording paper P conveyed between them. Therefore, each of these guide rollers 30 and 40 is a core roller 3 as shown in FIGS.
1 with 32 wraps of rubber material or Figure 3 c
and d (FIG. 3 d is a cross-sectional view of the guide roller 30' taken along line B-B shown in FIG. 3 c).
When the recording paper P is transported, thin rings 34 (thickness t = 0.1 mm) having a plurality of sharp edges are inserted at predetermined intervals in the long axis direction of the rollers 30' and 40' around which the recording paper P is wound. A sheet having a structure that can rotate with the recording paper P without causing slippage is used.

Furthermore, in the present invention, guide roller rotation angle detectors 300 (see FIGS. 3a and 3c) and 400 are attached to each rotating shaft 35 and 45 of each guide roller 30 and 40, respectively. FIG. 4a is a schematic diagram showing a specific configuration example of the guide roller rotation angle detectors 300 and 400, which are constructed using a well-known incremental shaft encoder. This incremental shaft encoder consists of a rotary plate 301 in which transparent parts and opaque parts are formed with uniform pitch, and a light emitting element 302 and a light receiving element 3 arranged opposite to each other with the rotary plate 301 in between.
When the rotary plate 301 rotates with the rotation of the guide rollers 30 and 40, light emitted from the light emitting element 302 is received by the light receiving element 304 via the rotary plate 301 and the slit plate 303. The output of the light-receiving element 304 at this time generates a pulse train as shown in FIG.

Therefore, by counting the number of light receiving output pulses of the light receiving element 304, each of the guide rollers 3
The rotation angles of 0 and 40 can be detected, and by performing predetermined calculations on each of these rotation angles, the feeding of the recording paper P that is conveyed as the guide rollers 30 and 40 rotate. The amount can be calculated. By the way, each guide roller rotation angle detector 300, 400 has a rotation angle corresponding to the minimum sub-scanning feed amount of one line of the recording paper P of the guide roller 30, 40 to which the detector 300, 400 is attached for the reason mentioned above. It must have a resolution that can detect the following: For example, when the minimum sub-scanning feed amount is 1/12 [mm], the diameter of each guide roller 30, 40 is 20 [mm] (that is, the circumference of each guide roller 30, 40 is 20 [mm]).
20π [mm]), the formula below is 1/12:20π=θ:360.It is possible to detect θ=0.477° or less, that is, the resolution is 754 (=360°/0.477°) pulses/rotation or more. Use. Next, the control for correcting the positional deviation of the transfer ink in each recording section will be described using the black recording section 100 as an example. FIG. 5 is a block diagram showing an example of the main part of the control circuit of the multicolor transfer type thermal recording apparatus of the present invention, that is, a control circuit for correcting the transfer position deviation of the black recording section. First, a predetermined control pulse is sent from the drive control section 50 to the drive roller drive circuit 51 in response to a recording start operation by the operator. The drive roller drive circuit 51 to which the control pulse is input sends a drive pulse to the stepping motor 150 for driving the drive roller 15 of the black recording section 100 to drive the stepping motor 150 and rotate the drive roller 15. As a result, transport of the black IDF 12 is started. Simultaneously with the start of conveyance of the black IDF 12, conveyance of the recording paper P is also started by a recording paper supply mechanism (not shown), and the recording paper P passes through the guide roller 30 and is first supplied to the black recording section 100. The guide roller 30 is rotated by the passage of the recording paper P, and as the recording paper P passes, the rotation angle detector 300 provided on the shaft outputs a pulse (fourth (see figure b) is generated and the pulse is detected by the counter.
It is counted in addition to C ₁ . This counter
The count value of _C1 is the next paper feed amount calculation circuit 53
is added to and converted into the actual feed amount of the recording paper P in the black recording section 100 through a predetermined calculation, and the converted value is then added to the comparator 54. On the other hand, the control pulses applied from the drive control section 50 to the drive roller drive circuit 51 are also applied to the counter _C0 , and counting of the control pulses is started at the same time as the counter _C1 starts counting. The count value of the counter _C0 is then added to the paper feed amount calculation circuit 52, and after a predetermined calculation, the recording paper P is moved to the black recording area under the control of the drive roller drive circuit 51 to which the control pulse is input. 100 is converted to the standard (ideal) feed amount that should be sent, and the converted value is also sent to the comparator 5.
Added to 4. Here, the comparator 54 compares the reference feed amount of the recording paper P in the black recording section 100 detected by the paper feed amount calculation circuits 52 and 53 with the actual feed amount, and compares the reference feed amount with the actual feed amount. On the other hand, as mentioned above, depending on whether the actual feed amount is more or less than the minimum feed amount of the recording paper P in the sub-scanning direction, that is, 1/12 [mm] in the apparatus of the present invention. A control signal is sent to the thermal head drive circuit 55.
Now, the actual feed amount is 1/12 than the standard feed amount.
If it is assumed that the number of pixels has increased by [mm], the comparator 54 sends, for example, a black image signal reduction signal to the thermal head drive circuit 55. Here, the thermal head drive circuit 55 drives the thermal head 1 of the black recording section 100 based on this reduction signal.
By stopping the supply of one line of black image information to be printed next for 0 and not printing, the feed amount of the recording paper P of the black recording section 100 is artificially corrected to the reference feed amount. do. By the way, regarding the printing result in this case, since the minimum surface information of the document that is normally used is more than two lines of the minimum standard feed distance of the recording paper P, as described above, one line of image information is deleted at the relevant recording location. However, the image information will not disappear. Contrary to the above, if the comparison result of the comparator 54 shows that the actual feed amount is 1/12 [mm] less than the reference feed amount, the comparator 54 For example, a black image information insertion signal is sent to 55. As a result, the thermal head drive circuit 55 additionally supplies one line of black image information to the thermal head 10 of the black recording section 100 and prints it, thereby printing the recording paper P of the black recording section 100 as described above. The feed amount is artificially corrected to the reference feed amount.

Note that the black image information for one line added here may be the image information recorded immediately before, or the image information to be recorded next. By continuously performing the above control during recording, the transfer position of black ink in the black recording section 100 can always be maintained at the transfer position when the recording paper P is fed by the standard feed amount. I can do it. Further, the transfer position deviation correction control circuit as described above is also configured for the red recording section 200, and the red recording section 2
Based on the comparison result between the feeding amount of the recording paper P in the red recording section 200 calculated from the rotation angle of the guide roller 40 arranged at 00 (detected value of the guide roller rotation angle detector 400) and the reference feeding amount. In the same manner as described above, the red image information is supplied to the thermal head 20 of the red recording section 200 for each line and corrected printing is performed. As a result, the transfer position of each color ink of each recording section can always be maintained at the reference position, and the positional deviation of each color transfer ink due to the difference in recording paper feeding amount between each recording section, which was a problem in the past, can be reduced, and the print quality is improved. It can greatly contribute to the improvement of

In the above embodiment, the reference feed amount for each recording section is set in advance, and the reference feed amount and the actual feed amount are compared. As described above, the method of printing by reducing or inserting one line of image information is compared, and the relative feed amount difference (minimum sub-scanning amount of the recording paper) is calculated by comparing the feed amount of the recording paper P between each recording section. Based on this, the same effect as described above can be expected by printing by reducing or inserting one line of image information of the thermal head of a specific recording section. Furthermore, it goes without saying that the present invention can be applied not only to two-color transfer type thermal recording apparatuses but also to multi-color transfer type thermal recording apparatuses.

〔Effect of the invention〕

As explained above, according to the multicolor transfer type thermal recording apparatus of the present invention, the recording paper feed amount of each recording section is detected from the rotation angle of the guide roller disposed in each recording section, and the respective feed amount is When the minimum feed amount of the recording unit increases or decreases by one line, the image information 1 of the recording color from the line thermal head of the recording unit
Since printing is performed by deleting or inserting a line, it is possible to reduce the transfer position shift of the line thermal head due to the difference in the feeding amount of the recording paper in each recording section, and it is possible to significantly improve the recording quality. be effective.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an example of the configuration of a conventional multicolor transfer type thermal recording device, FIG. 2 is a schematic configuration diagram of a multicolor transfer type thermal recording device showing an embodiment of the present invention, and FIG. 3 is a schematic diagram of a conventional multicolor transfer type thermal recording device. 3A and 3C are structural perspective views of the guide rollers according to the invention, and FIGS. 3B and d are structural perspective views of the guide rollers shown in FIGS. 3A and 3C, respectively. A-A sectional view, B-B sectional view, and FIGS. 4a and 4b are diagrams showing the schematic structure of a guide roller rotation angle detector installed in the device of the present invention, and the diagrams generated from the guide roller rotation angle detector. FIG. 5 is a block diagram showing the main part of the control circuit of the multicolor transfer type thermal recording apparatus of the present invention. 10, 20... thermal head, 11, 21...
...X crawler, 30, 40...Guide roller,
300, 400...Guide roller rotation angle detector,
301... Rotating plate, 302... Light emitting element, 303
... Slit plate, 304 ... Light receiving element, 50 ...
Drive control unit, 51...drive roller drive circuit,
52, 53...Paper feed amount calculation circuit, 54...Comparator, 55...Thermal head drive circuit, 150
...Stepping motor for driving the drive roller.

Claims (1)

[Claims] 1. Layer ordinary recording paper and an ink donor film coated with heat-melting or heat-sublimable ink, press them against a heat-sensitive recording head using a back roller, and selectively supply ink from the heat-sensitive recording head according to image information. In a multi-color transfer type thermal recording device, the multi-color transfer type thermal recording device is provided with recording sections for at least two colors, which melt ink using thermal energy and perform color transfer recording on the recording paper. A guide roller that is arranged and rotates according to the movement of the recording paper, and a guide roller that detects the rotation angle of the guide roller with a rotation angle accuracy corresponding to a minimum feed amount of one line in the sub-scanning direction of the recording paper. The feeding amount of the recording paper is calculated from the detected values of the rotation angle detector and the guide roller rotation angle detector, and the feeding amount of the recording paper of the recording section is set as a preset standard feeding amount or of 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 1, one line of the next image information to be added to the thermal recording head of the recording section is deleted. At the same time, the present invention is characterized by comprising a control means for inserting and printing one line of image information that has just been added or image information that is to be added next to the thermal recording head when the amount of feed has decreased by the minimum feed amount. A multicolor transfer type thermal recording device.