JPH0419029B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a recording apparatus such as a thermal printer or an inkjet printer that forms an image on a recording member using a pixel matrix of recording dots.

In recent years, in cases where high-speed recording using individual recording means is not possible, such as with thermal recording systems and inkjet-on-demand recording systems, it has become possible to perform high-speed recording by arranging recording means in a matrix configuration. A recording device has been proposed.

FIG. 1 shows an example of a recording head unit of a multicolor inkjet recording apparatus having such a configuration.
As shown in the figure, a recording head unit 1 includes a recording head 2 that ejects yellow, magenta, cyan, and black ink in the main scanning direction (arrow X direction).
Y, 2M, 2C, and 2BK are arranged, and each of these heads has a sub-scanning direction (arrow Y direction).
Three nozzles are arranged in. 3 like this
A recording head unit 1 having a matrix configuration of rows and four columns scans the recording paper in the main direction and performs a predetermined jump scan in the sub-scanning direction, thereby forming a multicolor image on the recording paper.

However, in the case of a recording device that creates a multicolor image by scanning multiple recording heads that eject different colored inks to the same position on the recording paper and superimposing the colored inks, it is necessary to If the ejected color ink is overlaid with another color ink before it has sufficiently dried, bleeding will occur between the color inks, resulting in a decrease in the quality of the recorded image. In order to eliminate this problem, in Figure 1,
Although it is necessary to provide a sufficiently wide interval between each recording head, the required interval may be limited due to the configuration of the recording head unit. The drawback was that it could not be fully utilized in color recording devices.

In view of the above-mentioned points, an object of the present invention is to provide a recording device that can produce high-resolution, high-quality color images at high speed.

That is, the present invention provides, based on image signals of multiple colors,
In a recording apparatus that forms a recorded image while performing main scanning and sub-scanning in two directions that are substantially orthogonal between a recording member and a support body to which a recording element is attached, the K resolution element spacing is N in the sub-scanning direction. having a plurality of rows of recording element groups in which the recording elements are arranged at predetermined intervals in the main scanning direction, and making the recording colors of each recording element group different from each other;
The rows of the plurality of recording element groups are arranged l in the sub-scanning direction.
The resolution elements are arranged in a stepwise manner with the intervals shifted, and the l
Main scanning of each color is performed by delaying the image signal of each color corresponding to the position where the resolution element interval is shifted according to the predetermined interval and supplying the delayed image signal to the recording element group of each color. A color image is recorded on the recording member by sub-scanning for N resolution element intervals for each scan, and the values of K and N are K/N.
The present invention provides a recording device characterized in that is a value that is an irreducible fraction.

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

FIG. 2 shows an example of a multicolor inkjet printer to which the present invention is applied, where 11 is recording paper;
12 is a paper feed roller that feeds the recording paper 11 in the Y direction;
13 is a paper feed pulse motor that drives the paper feed roller 12, and 14 is a paper guide roller that guides the recording paper 2. 15 is a multi-nozzle inkjet head unit that moves parallel to the opposing recording paper 1, and includes a yellow (Y) nozzle head 15Y,
Nozzle head 15M for magenta (M), cyan (C)
It consists of four color recording heads: a black (BK) nozzle head 15C and a black (BK) nozzle head 15BK.

Here, in the apparatus of the present invention, a recording element group in which N recording elements are arranged at an interval of K dots in the sub-scanning direction is arranged in M rows at an interval of L dots in the main scanning direction, and each recording element group is arranged in the sub-scanning direction. A recording head is constructed by arranging dots sequentially shifted by l dot intervals in the direction. Also, the values of K, l, M and N are expressed as: lM≦K ...(1) lM>K K(N-1)+1>l K/N: irreducible fraction ...(2) (1) or It shall be determined so that one of the relationships in formula (2) is satisfied.

An example of the configuration of the recording head 15 in this embodiment is shown in FIG. 3, and each nozzle head 15Y to 15BK has N=3 nozzles arranged at K=4 dot intervals in the sub-scanning direction (vertical direction in the figure). . These nozzle heads 15Y to 15BK are arranged in parallel in the main scanning direction (horizontal direction in the drawing) in the order of heads 15Y, 15M, 15C and 15BK at intervals of L=2 dots. Furthermore, as shown in the third figure, each nozzle head 1 is set back in the main scanning direction at every dot interval of l=1, starting from head 15BK.
Place 5Y to 15BK. Thus, in this example, K=4, l=1, M=4 and N=
3, and lM=4=K, which satisfies the above-mentioned equation (1). In addition, the dashed dotted line in FIG. 3 indicates each nozzle head 15Y to 15.
Shows BK main scanning lines. Each nozzle head 15Y,
15M, 15C, and 15BK have ink droplets that are ejected each time a pressure pulse is applied, or a bubble jet method that ejects ink using bubbles generated by embedding a heating element in the nozzle. Do a squirt.

Next, in FIG. 2, reference numeral 16 denotes a carriage unit that carries the inkjet head unit 15 and moves it back and forth in the L and R directions, and 17 a head feed pulse motor that moves the carriage unit 16 via a timing belt 18. , 19 is a guide rail for guiding the carriage unit 16, 20
and 21 are position sensors that detect the moving position of the head unit 15, and 22 is a position sensor that detects the moving position of the head unit 15.
This is an ink tank group that supplies ink to 5M, 15C, and 15BK. 24 is each head 15Y, 15
A flexible wiring board (power supply cable) that supplies drive signals to M, 15C, and 15BK, 25 is a flexible wiring board 24 and a driver circuit printed board 26
This is a relay terminal board that relays between The head unit 15 scans during reciprocating or forward movement, and selectively ejects ink from the nozzle, which is a recording element, based on a drive signal (image forming signal) supplied through the flexible wiring board 24, and prints a color original image on the recording paper 11. Record the reproduction.

Here, the recording operation of the recording head 15 will be explained. In the main scanning direction, it is driven by a pulse motor 17 and performs recording by moving forward or backward at one-dot intervals. That is, each nozzle head 15Y~
Connect each nozzle of 15BK to Y1 and Y as shown in the third diagram.
2, Y3, M1, M2, M3, C1, C2, C3
and BK1, BK2, and BK3, and the nozzle BK1 of the nozzle head 15BK is connected to the main scanning line of the recording paper 11.
Assuming that the position is on SL, the main scanning lines SL, SL+4, and SL are moved by forward or backward scanning, respectively.
+8 has black, main scanning line SL+1, SL+5,
SL+9 has cyan, main scanning line SL+2, SL+6,
Magenta for SL+10, main scanning line SL+3, SL+
7, each color of yellow ink is ejected to SL+11.

After forward or backward scanning is completed, the recording paper 11 is moved to each head 15Y to 1 by the pulse motor 13.
The paper is fed out by a dot interval corresponding to the number of nozzles of 5BK, that is, a 3-dot interval. This results in
The recording head 15 interlaces scans the recording paper 11 at intervals of 3 dots, and the nozzle BK/ on the main scanning line SL moves to the main scanning line (SL+3). The other nozzles move in the same way, and each color is printed at the corresponding position of each nozzle by subsequent forward or backward scanning.

As a result, focusing on the head 15BK shown in Figure 3, each main scanning line has each nozzle BK1 to BK3 by interlaced scanning at 3-dot intervals in the sub-scanning direction.
As a result, printing is performed as shown in FIG. 4, and no double printing or missing printing occurs in the same area. In general, when N nozzles are arranged in a line in the sub-scanning direction at K dot intervals, when each of the N nozzles prints at the same time every △t time, double striking and The condition for preventing printing omissions is that K/N is an irreducible fraction. In this example, N=3 and K=4, so K/N=4/3, which satisfies the above requirements.

Next, recording is performed by repeating main scanning and sub-scanning as described above, but in order to form a multicolor image, each main scanning line must be scanned by a head that ejects a different colored ink. There must be. In this example, the head is 15Y to 15BK.
Therefore, a total of four scans are required, one for each. Generally, if the spatial coordinates of the recording position on the recording paper by the m1th recording head are Zm ₁ and the spatial coordinates of the m2th recording head are Zm ₂ , then these m1th and m2th recording heads can print the same position on the recording paper. In order for the position to be scanned, the following condition must be satisfied: Zm ₁ =Zm ₂ (m ₁ ≠m ₂ ).

In this example, for example, the main scanning line SL+1 shown in the third figure
1, nozzles Y3, BK3, C2, M1
The main scanning line SL+11 is scanned in this order, and the colored inks of yellow, black, cyan, and magenta are superimposed in this order to form a multicolor image. The same goes for other main scanning lines, and each head 15
Letting the spatial coordinates where the nozzles of Y to 15BK are located as Z _Y , Z _M , Z _C , and Z _BK , the relationship Z _Y = Z _M = Z _C = Z _BK holds true for each main scanning line. That is, a multicolor image is formed on the recording paper 11 by overlapping yellow, magenta, cyan, and yellow color inks.

Here, the color ink at each print position on the recording paper 11 is superposed each time the recording head moves forward and backward, as described above, so that the color ink ejected onto the recording paper 11 is After sufficiently drying, another colored ink is superimposed, and bleeding caused by superimposing colored inks unlike in the past does not occur.

Next, in this example, it is assumed that the reading head (not shown) that reads the original image is composed of a single sensor, and FIG. 5 shows the control circuit for recording with the recording head 15 shown in FIG. An example is shown.

In the figure, BS, CS, MS, and YS are black, cyan, magenta, and yellow color signals corresponding to the original image read through a reading head (not shown). 51 to 60 are delay circuits, 61
-64 are switching circuits, and the recording head 1
During the forward movement of No. 5, it is set to the solid line position shown in the figure, and during the backward movement, it is set to the broken line position shown in the figure. 65～
72 is a delay circuit, Y1 to Y3, M1 to M3, C1
~C3 and BK1~BK3 are the nozzle heads 15Y, 15M, 15C and 15 described above, respectively.
These are BK nozzles. In this example, delay circuits 51 to 6
0, the supplied color signal is delayed by two dot intervals, and the delay circuits 66 to 72 are delayed by four main scanning lines. As a result, during forward movement, the yellow signal YS is supplied to the nozzle Y3 via the switching circuit 64, the signal YS delayed by four main scanning lines is supplied to the nozzle Y2 via the delay circuit 71, and the signal YS delayed by four main scanning lines is supplied to the nozzle Y1. Signal delayed by 8 main scanning lines via delay circuits 71 and 72
YS is supplied at the same time. On the other hand, the magenta signal MS is transmitted to the switching circuit 6 during forward movement.
The signal is supplied to the delay circuit 56 via M3, and after being delayed by two dot intervals, it is supplied to the nozzle M3. The nozzles M2 and M1 are the aforementioned nozzles Y2 and Y.
Similarly to the case in No. 1, the magenta signal MS is supplied after being delayed by 4 and 8 main scanning lines, respectively. The cyan signal CS is delayed by 4 dot intervals by delay circuits 54 and 55 and supplied to each nozzle C3 to C1, and the black signal BS is delayed by 6 dot intervals by delay circuits 51, 52 and 53 and supplied to each nozzle BK3 to BK3. Supplied to BK1.

As a result, each nozzle Y1 at the same time
~Y3, M1~M3, C1~C3 and BK1~
A signal of the original image corresponding to the part where BK3 is located is supplied. By ejecting ink according to the supplied color signals in synchronization with the forward movement of the head 15, the original image is reproduced on the recording paper 11.
In addition, during the backward movement, the switching circuits 61 to 64 are switched and set to the position shown by the broken line, and a delay operation opposite to that during the forward movement is performed, so that the original image is transferred to the recording paper 1.
1 will be played back.

In this example, the head configuration satisfies the above-mentioned formula (1), but the values of K, M, N, and l are lM>K, K(N-1)+1>l, respectively. In the case of the head configuration, K/N must be an irreducible fraction so that each nozzle head 15Y to 15BK does not print on the same main scanning line on the recording paper 11 during one scan. In other words, even in the case of a head configuration that satisfies equation (2) above, the control circuit shown in FIG.
Recording can be reproduced by reciprocating the recording head 15 on the recording head 1.

As explained above, in the present invention, in a recording apparatus such as a thermal printer or an inkjet printer that forms an image on a recording material by a pixel matrix of recording dots, N dots are formed at intervals of K in the sub-scanning direction. By arranging recording element groups in which recording elements are arranged in M rows in the main scanning direction at an interval of L dots, and by sequentially shifting each recording element group by an interval of L dots in the sub-scanning direction. ) A pixel matrix of dots was constructed. In addition, the values of N and K are determined so that K/N is an irreducible fraction, and these K, l, M,
and the value of N was determined to satisfy either of the following relationships: l·M≦K or lM>K K(N-1)+1>l K/N: irreducible fraction.
Further, with the recording head configured in this way, it is possible to scan the same main scanning line M times by M rows of recording element groups to form a recorded image on the recording member based on M signals. I did it like that.

As a result, for example, the present invention can be applied to a multicolor recording device that forms a color image by overlapping M types of color inks based on M color signals, and M columns of recording element groups can be converted into M color signals. By ejecting colored inks in a one-to-one correspondence, different colored inks can be superimposed on the colored ink ejected first after sufficient time has passed for it to dry.
Deterioration in image quality caused by bleeding between superimposed color inks can be avoided.

As described above, according to the present invention, a high-quality color recorded image can be obtained when recording is performed based on a plurality of signals in a recording device that arranges recording elements in a matrix configuration and performs high-speed, high-resolution recording. .

[Brief explanation of drawings]

FIG. 1 is a diagram showing an example of a conventional recording head unit, FIG. 2 is a perspective view showing an example of the configuration of the apparatus of the present invention, and FIG. 3 is a diagram showing an example of the configuration of the recording head unit of the apparatus shown in FIG. 4 is a diagram illustrating printing positions by each nozzle of the nozzle head 15BK, and FIG. 5 is a block diagram showing an example of a control section for driving the recording head unit shown in FIG. 3. 1... Recording head unit, 2Y, 2M, 2
C, 2BK... Recording head, 11... Recording paper, 1
2...Paper feed roller, 13...Pulse motor, 1
4... Paper guide roller, 15... Head unit, 15Y, 15M, 15C, 15BK... Recording head, 16... Carriage unit, 17...
Pulse motor, 18... Timing belt, 19
... Guide rail, 20, 21 ... Position sensor,
22... Ink tank group, 23... Ink supply pipe, 24... Flexible wiring board, 25... Terminal board, 26... Driver circuit printed board, 51-
60, 65-72...delay circuit, 61-64...
Switching circuit, BS, CS, MS, YS...signal, Y1-Y3, M1-M3, C1-C3, BK
1~BK3...Head nozzle, SL, SL+1, SL
+2...Main scanning line.

Claims (1)

[Claims] 1. Forming a recorded image based on image signals of a plurality of colors while performing main scanning and sub-scanning in two substantially orthogonal directions between a recording member and a support to which a recording element is attached. In the recording device, there is provided a plurality of rows of recording element groups in which the N recording elements are arranged at K resolution element intervals in the sub-scanning direction at predetermined intervals in the main scanning direction, and each recording element group has a The recording colors are made to be different from each other, and the rows of the plurality of recording element groups are arranged in a stepwise manner by shifting l resolution element intervals in the sub-scanning direction, and image signals of each color corresponding to positions shifted by the l resolution element intervals are generated. Main scanning of each color is performed by supplying the recording element group of each color with a delay according to the predetermined interval, and sub-scanning is performed for N resolution element intervals for each main scanning of the column of the plurality of recording element groups. A recording apparatus that records a color image on a recording member, and wherein the values of K and N are values such that K/N is an irreducible fraction. 2. The recording device according to claim 1, wherein the recording element records an image by ejecting ink onto a recording member. 3. The recording apparatus according to claim 2, wherein the recording element ejects ink using bubbles generated by heat generated by a heating element.