JPS6253349B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a multicolor recording device that performs multicolor recording using a thermal transfer recording method, and more particularly to a multicolor recording device that can limit color shift in images to local areas. .

In the thermal transfer recording method, an ink donor sheet with heat-fusible solid ink coated on one side of a base paper is used as a recording medium, and heat is selectively supplied to the ink donor sheet from a thermal head in accordance with image information. Then, the dissolved ink is transferred onto paper to record information. Therefore, multiple types of ink donor sheets each coated with solid ink of different hues are prepared.
If thermal transfer recording is performed one after another using these ink donor sheets on one sheet of paper, multicolor recording can be performed using the thermal transfer recording method.

In a multicolor recording apparatus that employs such a recording method, a plurality of recording units for multicolor recording are provided at predetermined intervals on a paper conveyance path. During recording, the paper is conveyed along this conveyance path, and an image signal of a hue corresponding to each recording section is supplied to each recording section to perform multicolor recording. At this time, the second and subsequent recording units placed on the conveyance path are supplied with an image signal delayed by a time calculated in advance according to the traveling speed of the paper and the distance from the first recording unit, The images recorded in each recording section are aligned.

However, in such a multicolor recording device, if the paper becomes deflected after recording is performed in the first recording section and before recording is performed in the last recording section, subsequent recordings will be affected. The supply timing of the image signal is shifted in some parts. In this case, color shift occurs over the entire image area or over a considerable area, resulting in a significant deterioration of image quality.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a multicolor recording device that is capable of suppressing color misregistration to only localized areas even if color misregistration occurs in an image due to paper deflection, etc. purpose.

In the multicolor recording apparatus of the present invention, the first recording section that records on the paper first among the plurality of recording sections for performing multicolor recording has a plurality of record the mark. The above-mentioned object is achieved by detecting these marks at or near each recording section where recording will be performed later, and aligning the recording timing in these recording sections.

The present invention will be explained in detail with reference to Examples below.

FIG. 1 shows a multicolor recording apparatus equipped with three recording sections. This multicolor recording device includes a first back roll 11, an M color ink donor sheet 12 in which magenta ink is applied to a base paper, and a first supply roll 1 that supplies the M color ink donor sheet 12.
3. A first thermal recording head 14 that contacts the first back roll 11 via the supplied M-color ink donor sheet 12, and a first take-up roll 15 that collects the M-color ink donor sheet 12 after transfer.
constitutes a first recording section that records in magenta color. In addition, a second back roll 21, a Y-color ink donor sheet 22 with yellow ink applied to a base paper, a second supply roll 23 that supplies the Y-color ink donor sheet 22, and a Y-color ink donor sheet 22 that has been supplied are A second thermal recording head 24 that contacts the second back roll 21 and a second take-up roll 25 that collects the Y-color ink donor sheet 22 after transfer are connected to a second recording section that records in yellow. It consists of Furthermore, the third back crawl 3
1. C color ink donor sheet 32 with cyan ink applied to base paper, C color ink donor sheet 3
2, a third thermal recording head 3 in contact with a third back roll 31 via a supplied C-color ink donor sheet 32;
4, and C color ink donor sheet 32 after transfer
The third take-up roll 35 that collects the toner constitutes a third recording section that records in cyan. A pair of paper guides 51 and 52 for guiding the feeding of the paper 40 is provided in the paper transport path between the first recording section and the second recording section.
A first mark sensor 53 is attached near the second back roll 21. Similarly, a pair of paper guides 54 and 55 for guiding the feeding of the paper 40 are provided in the paper transport path between the second recording section and the third recording section. A second mark sensor 56 is attached near the backroll 31.

Now, when a start button (not shown) is pressed, this multicolor recording apparatus starts recording operation. The multicolor recording printer is equipped with a clock generator (not shown) for generating various reference signals. The clock generator outputs a step signal for conveying paper from the stage when the start button is pressed. This step signal is supplied to a pulse motor, also not shown, via a pulse motor drive circuit, not shown. As a result, a feed roll (not shown) is driven, and the paper 40 is fed to the front of the first recording section.

At this point, the clock generator described above outputs a step signal for the ink donor sheet run. This step signal is supplied to another pulse motor (not shown) via another pulse motor drive circuit (not shown). As a result, the backroll 1 of each recording section
1, 21, 31, supply roll 13, 23, 33,
The take-up rolls 14, 24, and 34 each start rotating at a constant speed in the direction of the arrow, and accordingly, the ink donor sheets 12, 22, and 32 are run in the direction of the arrow while maintaining constant tension. As a result, when the paper 40 is fed out until its leading edge reaches the contact part (transfer part) 6 between the first back roll 11 and the M color ink donor sheet 12, the paper 40 is transferred by the back rolls 11, 21, and 31 of each recording part. Thereafter, the object is conveyed along the conveyance path in the direction of the arrow.

Now, at time _t1 when the leading edge of the paper 40 reaches the transfer section 16 of the first recording section, supply of an image signal for magenta color recording (hereinafter referred to as M color image signal) is started from a word processor (not shown). Ru.
The M color image signal is directly supplied to a thermal recording head drive circuit (not shown) for magenta color recording, and the first thermal recording head 14 is driven. As a result, thermal transfer recording using the M color image signal is started from time _t1 as shown in FIG. 2a.

The above-mentioned clock generator generates a mark signal (FIG. 2b) at a predetermined period during the time period from time _t1 to time _t2 when recording of magenta color ends. These mark signals are supplied to a heating element arranged near the main scanning start point of the first thermal recording head 14. As a result, as shown in FIG. 3, in addition to the image information 41, dot-like marks 42 are recorded on the paper 40 in the margins at the side edges of the paper.
These marks 42 are used for alignment of the second recording section and the third recording position.

FIG. 4 shows a control circuit for recording position alignment in the second recording section. This control circuit includes first and second image signal memories 61 and 62, and a first memory for reading out an image signal for yellow recording (hereinafter referred to as Y color image signal) from these image signal memories.
and second read counters 63 and 64, a changeover switch 65 for controlling these read counters, and a delay circuit 66 for delaying the output of the first mark sensor 53 to operate the changeover switch 65, and The image signal is sent to the second thermal recording head 2.
It is composed of an OR circuit 67 for supplying the signal to the drive circuit for 4.

The Y color image signal 68 supplied from the word processor to this multicolor recording device is stored in the first image signal memory 6.
Starting from 1, the image signals are written to the first and second image signal memories 61 and 62 alternately at predetermined time intervals. 1st
The image signals written in the second image signal memories 61 and 62 are written overlappingly in time at the switching timing, and the temporal length of the image signal once written in each image signal memory is determined by the mark signal. It is set slightly longer than the occurrence period of .

Now, when the paper 40 is conveyed to the transfer section 26 of the second recording section, the first mark sensor 53 detects the mark 42 (FIG. 2c). The elapsed time T ₁ from the time t 1 when the first mark is recorded to the time t ₃ when the mark is detected by the first mark sensor 53 is the elapsed time T ₁ between the first thermal recording head 14 and the first mark sensor 53 . the distance between them, the transport speed of the paper 40,
Alternatively, it is a value that varies depending on various conditions such as the deflection of the paper 40. The delay counter 66 first calculates the time T ₂ required for the mark 42 to move from the first thermal recording head 14 to the second thermal recording head 24 based on this elapsed time T ₁ . Time T ₃ obtained by subtracting elapsed time T ₁ from this time T ₂
(D in FIG. 2) is the time from when the mark 42 is detected by the first mark sensor 53 until the part of the paper on which this mark is written reaches the second thermal recording head 24. The delay counter 66 sets this time _T3 as a delay time.

Therefore, when the detection signals 69 for the marks 42 are sequentially outputted from the first mark sensor 53 to the delay counter 66, the delay counter 66 sequentially supplies delayed detection signals 71 to the changeover switch 65. When the changeover switch 65 receives the first detection signal 71, it uses this as the start signal 72 and switches it to the first detection signal 71.
It is output to the read counter 63 of. As a result, the read signal 73 is supplied from the first read counter 63 to the first image signal memory 61, and the supply of the Y color image signal 74 from the first image signal memory 61 to the head drive circuit via the OR circuit 67 is started. be done.

When the delay counter 66 generates the second detection signal 34 at a later time, the changeover switch 65 that receives this signal supplies a clear signal 75 to the clear terminal CL of the first read counter 63. and clear the counted value. At the same time, the changeover switch 65 supplies a start signal 76 to the second read counter 64.
As a result, while the read signal 73 is cut off, the supply of the read signal 77 from the second read counter 64 to the second image signal memory 62 is started. As a result, supply of the aligned Y color image signal 74 from the second image signal memory 62 to the head drive circuit via the OR circuit 67 is started.

Thereafter, the adjusted Y color image signal 74 is alternately outputted from the first and second image signal memories 61 and 62 in the same manner. The print head drive circuit drives the second thermal recording head 24 based on these Y color image signals 74. As a result, recording is performed on the paper 40 using the Y color image signal in which the color shift of the image is corrected for each mark 42.

The control circuit for such recording position alignment is
A third recording section that records cyan color is also provided. Therefore, the second mark sensor 56 detects the time.
When the mark 42 is detected at time t ₄ after t ₃ (FIG. 2e), a delay circuit (not shown) calculates the time T ₄ to be delayed. Each time the mark 42 is detected, the control circuit generates a cyan color recording image signal (hereinafter referred to as C color image signal) with a delay of time _T4 (FIG. 2f). The third thermal recording head 35 is
It is driven based on C color image signals alternately output from two image signal memories (not shown). As a result, recording is performed on the paper 40 using the C color image signal in which the color shift of the image is corrected for each mark 42.

As described above, according to the present invention, it is possible to correct color misregistration of an image independently of the multicolor recording device without placing a burden on a host system such as a word processor.

Note that in the embodiment, the mark sensor was provided near the transfer section where thermal transfer recording is performed, but by arranging the back roll slightly shifted in the main scanning direction and providing the mark sensor in the space created by this,
It is also possible to completely match the positions of the transfer part and the mark sensor. Further, in the embodiment, multicolor recording using three colors of cyan, magenta, and yellow has been described, but it goes without saying that the present invention can be applied to all multicolor recording using two or more colors.

[Brief explanation of the drawing]

The drawings are for explaining one embodiment of the present invention, and FIG. 1 is a side view showing the main parts of a multicolor recording device, FIG. 2 is an explanatory diagram for explaining image alignment, and FIG. FIG. 3 is an explanatory diagram for explaining the recording state of paper, and FIG. 4 is a block diagram of a control circuit for aligning recording positions in the second recording section. 12... M color ink donor sheet, 14... First thermal recording head, 22... Y color ink donor sheet,
24...Second thermal recording head, 32...C color ink donor sheet, 34...Third thermal recording head, 40...
Paper, 42... Mark, 51... First mark sensor, 56... Second mark sensor, 61... First image signal memory, 62... Second image signal memory, 63...
1st read counter, 64...2nd read counter, 65...changeover switch, 66...delay counter.

Claims (1)

[Claims] 1 Receiving an image signal related to a certain hue, thermal transfer recording is performed on the paper using a thermal recording head and an ink donor sheet for recording in the said hue, and a plurality of image signals are placed at predetermined intervals in the sub-scanning direction. a first recording unit that thermally transfers and records marks on the paper; and a first recording unit that is provided on the paper conveyance path and that separately detects a plurality of marks recorded on the paper that is conveyed via the first recording unit; A plurality of mark sensors are provided at or near the positions where the mark sensors are arranged, and are supplied with image signals relating to hues different from the above-mentioned hues. Every time a predetermined time elapses after the mark sensor detects a mark using the ink donor sheet for recording, thermal transfer recording of image information corresponding to the detected mark to the next detected mark is performed. A multicolor recording device characterized by comprising one or more recording units other than those described above that perform recording on paper.