JP3276439B2 - Inkjet printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet color printer, and more particularly, to an ink jet color printer which interpolates and prints a part of a non-ejection nozzle in a plurality of nozzles of a multi-nozzle head. <br/> concerning.

[0002]

2. Description of the Related Art For example, ink-on-demand printing or printing is performed by applying a pressure change to an ink liquid in a liquid chamber by utilizing the electromechanical conversion action of a piezo element to discharge the ink liquid from a discharge port of the liquid chamber. In a multi-printer printer, if any one of the multi-nozzles having a plurality of nozzles does not discharge, white streaks will occur on printing, resulting in a printed material that cannot be officially used. When such a non-ejection nozzle occurs, there has conventionally been no means to cope with the problem except for exchanging the head or exchanging the cartridge.

In order to reduce such an economic burden as much as possible, there is a disposable type (disposable) cartridge, and when a non-ejection nozzle occurs, it is attempted to replace it with a new cartridge. As a result, the problem of the non-ejection nozzle is eliminated, and the printer is conveniently restored to the normal function. However, when the ink remains in the cartridge, there is a case where the burden on the user cannot be reduced.

Further, in the case of a long-life head, even if the reliability of the head has been sufficiently confirmed, an unexpected accident causes a large damage. 3 nozzles
Of the two, 64, or 128 nozzles, printing is not possible even if one nozzle fails to discharge, resulting in a large loss for both the user and the manufacturer.

[0005]

[Object] The present invention has been made in view of the above circumstances,
It is an object of the present invention to provide an ink jet color printer capable of performing normal printing by interpolating data of non-printable nozzles that cannot be printed with printable discharge nozzles, thereby reducing the economic burden on the user.

[0006]

To achieve the above object, the present invention provides (1)
Chi lifting a plurality of heads having a plurality of nozzles for printing ejecting ink droplets, the plurality several heads, the same nozzle
The nozzle with the file number determines the physical position in the line feed direction.
In an ink-on-demand color printer arranged equally, test pattern printing means for printing a self-test pattern for determining whether or not the plurality of nozzles are normally discharging ink, and Non-discharge nozzle number input means for visually discriminating the non-discharge nozzle based on the self-test pattern and manually inputting the discriminated non-discharge nozzle number, and storage means for storing the input non-discharge nozzle number A first sequence in which data corresponding to a normal ejection nozzle is printed by the normal nozzle, and a second sequence in which a normal ejection nozzle feeds a new line for data corresponding to a non-ejection nozzle of a nozzle number stored in the storage means. And a non-ejection portion data interpolation printing control means comprising the following sequence: Normal nozzles and non-discharge nozzles in the medium A
An ND condition is set, and the number of continuous nozzles satisfying the AND condition is set as a processing unit.
In the non-ejection portion data interpolation print control means, having a plurality of sequences to print a new line of normal nozzles for data corresponding to the non-ejection nozzle, to enable interpolation of non-ejection portion printing, further, (3) In the above (1) or (2), in a multi-nozzle head having k continuous normal ejection nozzles, a first sequence for printing k data as data corresponding to one normal nozzle, and kdo
a non-ejection portion data interpolation printing control means consisting of a second sequence for performing line feed for t and printing;
(4) In the above (1), in a multi-head printer such as Y, M, C, and Bk (yellow, magenta, cyan, and black), an AND condition of normal ejection nozzle numbers of the Y, M, C, and Bk is obtained. Logical product detection means, a first sequence in which m consecutive normal ejection nozzles detected by the logical product detection means are printed as one normal nozzle, and mdot line feed to print with m normal discharge nozzles And a second non-ejection portion data interpolation printing means. less than,
A description will be given based on an embodiment of the present invention. First, a multi-nozzle and an electric circuit block to which the inkjet printer according to the present invention is applied will be described.

[0007] Figure 1 is a multi-nozzle head and self-test pattern output diagram, in FIG, 1 is a multi-nozzle head, 2 a nozzle, 3 a self-test pattern, nozzle 2, 2-1 to 2-n (In the figure, 16) are provided. When printing, multi-nozzle head 1
Discharges ink droplets from necessary nozzles 2 while moving in the horizontal direction (main scanning) to form an image.

FIG. 3 is a schematic circuit block diagram for driving the multi-nozzle head. In the figure, 4 is a CPU (Central Processing Unit), 5 is a ROM (Read Only Memory), and 6 is a RAM.
(Random Access Memory), 7 is an (input device), 8 is a nozzle number input unit, 9 is a head driver, and 10 is an SP.
(Stepping) motor driver, 11 is an SP (stepping) motor, 12 is an LF (Line Feed) motor driver, and 13 is an LF motor.

The multi-nozzle head 1 discharges ink droplets in accordance with a drive command from a head driver 9. At the same time SP
The motor 11 and the LF motor 13 are driven to output the self test pattern 3 of FIG. The self-test pattern 3 is recorded for confirming the ejection or non-ejection of ink droplets from the nozzles 2. Most printers have a self-test print function.

The self test pattern 3 shown in FIG. 1 is for the case where all of the nozzles 2 normally eject ink droplets.
While moving in the main scanning direction, the single nozzles 2-1 and 2-2,
.., Several to several tens (four in the figure) of ink droplets are ejected every 2-n, and the self-test patterns 3-1 and 3- in FIG.
2,..., 3-n are obtained. Since all the nozzles 2 of the multi-nozzle head 1 in FIG. 1 are normal, all the self-test patterns 3 are output from 3-1 to 3-n, and normal ejection can be confirmed.

FIG. 2 is a diagram showing an example of a self-test pattern 3 having a non-ejection portion. The example of FIG. 2 is a case where the fourth nozzle 2-4 from the top does not eject. The portion 3-4 becomes blank, and the user can know the number of the defective nozzle only by looking at the result. FIG.
2 is a diagram when printing is performed using the multi-nozzle head having a defective nozzle in FIG.
The portion 4 is not printed and becomes a white streak. Since the white streaks appear every line, the image quality is significantly degraded. In addition,
Conventionally, when such a non-ejection nozzle occurs, if recovery is not possible even by taking recovery means provided in the printer,
As described above, the replacement of the cartridge or the replacement of the head has been performed. However, in the present invention, measures based on the following configuration are taken.

When the user performs a self-test according to a normal sequence and finds that the nozzles 2-4 shown in FIG. 2 do not discharge, for example, the nozzle number input means 8 (for example, Enter the number “4” into the dip switch (Dip Sw) or numeric keypad. The CPU 4 stores the input number 4 in the RAM 6, and thereafter keeps holding this number.

FIG. 5 is a diagram for explaining the principle of interpolation printing in the present invention. In this state, when a print start command is received, the first printing 21 is performed by the CPU 4 in a normal first sequence. . In the first printing 21, the fourth nozzle 2-4 is not printed and white streaks are formed. Next, the CPU 4 performs a line feed for one dot by the second sequence, and prints a white streak portion in the print 21 with the third nozzle 2-3 to obtain a print 22. At this time, the data at the fourth dot in the data buffer is all shifted to the third dot, and all other data is set to 0 (white) or controlled so as not to be printed with a mask.

As described above, normal printing without white streaks can be achieved by combining the first and second sequences and interpolating the non-ejection data. When this is completed, the line feed is changed to (n-1) dots, in this case, (16-1) dots, and printing of the original second line is started. Thus, to print successfully poor white streak portion by printing separately printing the first line in two
Can be .

FIG. 6 is a diagram showing an example of interpolation printing when there are a plurality of non-ejection nozzles.
4, 2-14, 2-15, and 2-16. In the case of the first printing by the first sequence,
The print 21 excluding the 14th, 15th, and 16th is obtained.
Next, the line is changed to 3 dots, the second printing is performed by the second sequence, and a print 22 is obtained. At this time, even if there are a plurality of non-ejection nozzles, interpolation printing can be performed by printing twice by performing a line feed of 3 dots. However, interpolation printing may not be performed in two sequences.

FIG. 7 is a diagram showing an example in which interpolation printing cannot be performed in the second printing.
7, 2-14, 2-15 and 2-16, and in the case of printing by the first sequence, 4, 7, 1
The print 21 excluding the fourth, fifteenth and sixteenth prints is obtained, and the second print is obtained.
In the second printing according to the sequence, a print 22 is obtained with a line feed of 3 dots. However, by breaking 3 dots, 7
Since the non-ejection nozzles in the dot portion overlap, the line is fed back by one dot in the third sequence, and printing is performed by 2-3 nozzles. As described above, in the example of FIG. 7, normal printing can be performed by performing interpolation printing three times.

As another interpolation method, the non-discharge nozzles are continuously arranged in the arrangement of all nozzles, such as the upper half or the lower half, and further the upper quarter or the lower quarter. There are cases.

FIGS. 8 (a) and 8 (b) are diagrams showing an example of interpolation printing in a case where there are k consecutive ejection nozzles. FIG. 8 (a) shows k continuous normal nozzles in the upper part. In the case where the normal nozzles are used, (b) shows a modification in which a part of the continuous k normal nozzles (k-2 in the figure) is used as one normal nozzle.

That is, in FIG. 8A, the CPU
4 determines that non-discharge nozzles are concentrated in the lower half,
The continuous number k of normal nozzles is set as a processing unit of one print sequence. That is, the number of nozzles of the head mounted on the printer is virtually set to kdot heads,
Other nozzles are not used. A buffer memory (not shown) outputs only k (10 in FIG. 9A) out of 16 bits (example of FIG. 8A), and 11 to 16 bits in the next row and 1 to 4 in the original second row. It is necessary to perform an operation for hitting a bit.

Further, since the CPU 4 can easily perform 8-bit or 16-bit calculations, interpolation processing may be performed with a value smaller than k which is an integral multiple of 8 instead of k, and printing may be performed in the processing unit. For example, as shown in FIG. 8B, printing is performed on the assumption that k = 8 and an 8-nozzle head is mounted. This method is easy to process on the CPU 4, but on the other hand,
(A) The printing speed is lower than when k = 10 in the figure.

FIG. 9 shows an example of interpolation in the case of a multi-head color printer in which a plurality of heads are mounted , that is, the present invention.
An example of an inkjet color printer by
The head ejects four kinds of inks of Y (yellow), M (magenta), C (cyan) and Bk (black). The heads that eject the respective color inks are denoted by I _Y , I _M , I _C, and I _Bk .

In the case of a color printer, one line is Y, M,
All heads I _Y , I _M , I _C
And I _Bk are printed with a slight time difference. And one
Move to the next line with a new line. Therefore, if head I _Y ,
When any of the heads I _M , I _C and I _Bk has a non-discharge nozzle, the method of determining the line feed amount at the position of the non-discharge nozzle only for the head of the color having the non-discharge nozzle cannot be basically applied. In addition, LF (Line Feed) must be performed in the reverse direction, which complicates the control.

Therefore, according to the present invention, the heads I _Y , I _M ,
In a plurality of heads of I _C and I _Bk , a pair
And physically determine the nozzle positions of I _Y1 , I _M1 , I _C1 , and I _Bk1
In the same nozzle number, the AND conditions of the normal nozzle and the non-ejection nozzle are set. As shown in the figure, for example, when the number of nozzle numbers for which the AND condition of the normal nozzles is satisfied is m, mdot is assumed to be one processing unit, that is, mdot nozzles are mounted, and The overprint 24 of Y, M, C, and Bk is printed, and then a line feed of mdot is made, and the overprint 25 of Y, M, C, and Bk on the second line is similarly printed. In this way, all the buffer shifts are performed in units of m.

As described above, if the normal nozzles of Y, M, C, and Bk are subjected to the AND condition for each dot, and all the nozzles are normal, and only the normal nozzles of all the upper and lower nozzles are one blot, the print amount per scan is: Although there is less data missing, the output print result is good.

Conventionally, if even one of the nozzles failed to discharge, it was replaced with a new one because the service life had expired. However, according to the method of the present invention, interpolation printing (see FIG. 9) was performed as long as the last one nozzle was alive. Multi-head is excluded), and the burden of running cost on the user is reduced.

[0026]

As apparent from the above description, the present invention has the following effects. According to the first aspect, a portion where a non-discharge nozzle is generated and printing is impossible can be interpolated and printed with a normal discharge nozzle. Therefore, there is no need to replace the head, and the user can be provided with a printer system with low running cost. Advantageous effect corresponding to claim 2: It provides a method in a case where interpolation cannot be completed by one interpolation, which is an application expansion of claim 1 and has an effect of further expanding an interpolation range. Effect corresponding to claim 3; As shown in FIGS. 6 and 7, an LF (Line Feed) for a small number of dots for performing interpolation is not required, and the total LF time per page is suppressed, thereby improving the throughput. improves. In the case of a multi-head, if there is non-ejection even in one nozzle of one head, the color balance is lost. In addition, the tint changes depending on the order of overlapping the colors. Originally, 1 without changing the printing order of Y, M, C, and Bk.
Since it is desired to perform printing as a unit of block, the present invention can implement the printing, and can provide a method with excellent image quality of running cost.

[Brief description of the drawings]

FIG. 1 is a multi-nozzle head and test pattern output diagram according to the present invention.

FIG. 2 is a diagram illustrating an example of a self-test pattern having a non-ejection portion.

FIG. 3 is a schematic circuit block diagram for driving a multi-nozzle head.

FIG. 4 is a diagram when printing is performed using a multi-nozzle head having a defective nozzle in FIG. 2;

FIG. 5 is a diagram for explaining an example of interpolation printing in the present invention.

FIG. 6 is a diagram showing an example of interpolation printing when there are a plurality of non-ejection nozzles.

FIG. 7 is a diagram illustrating an example in which interpolation printing cannot be performed in the second printing.

FIG. 8 is a diagram illustrating an example of interpolation printing in a case where there are k consecutive defective ejection nozzles.

FIG. 9 is a diagram for explaining an example of interpolation in the case of a multi-head printer in which a plurality of heads are mounted.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Multi-nozzle head, 2 ... Nozzle, 3 ... Self-test pattern, 4 ... CPU (Central processing unit), 5 ... R
OM (Read Only Memory), 6 ... RAM (Random Access)
Memory), 7 input device, 8 nozzle number input means, 9 head driver, 10 SP (stepping)
Motor driver, 11 ... SP (stepping) motor,
12 ... LF (Line Feed) motor driver, 13 ... LF
motor.

Claims (4)

(57) [Claims] 1. A Chi lifting a plurality of heads having a plurality of nozzles for printing ejecting ink droplets, the plurality several heads
Indicates that nozzles with the same nozzle number
Pattern printing means for printing a self-test pattern for judging whether or not the plurality of nozzles normally perform ink ejection in an ink-on-demand color printer arranged at the same physical position. Non-discharge nozzle number input means for visually discriminating the non-discharge nozzle based on the printed self-test pattern, and manually inputting the number of the determined non-discharge nozzle, and the input non-discharge nozzle number And a first line for printing data corresponding to a normal ejection nozzle by the normal nozzle, and a line feed of a normal ejection nozzle for data corresponding to a non-ejection nozzle of a nozzle number stored in the storage unit. And non-ejection portion data interpolation printing control means comprising a second sequence for performing printing. Of taking a normal nozzle and AND condition of non-ejection nozzles in a nozzle number, ink jet color printer, which comprises a processing unit the number of nozzles consecutive said AND condition is satisfied. 2. The non-ejection portion data interpolation print control means includes a sequence of printing a new line of a normal nozzle for data corresponding to the non-ejection nozzle a plurality of times to enable interpolation of non-ejection portion printing. The inkjet printer according to claim 1, wherein: 3. In a multi-nozzle head having k continuous normal nozzles, a first sequence for printing k data as data corresponding to one normal nozzle, and kdot
Inkjet color printer according to claim 1 or 2, characterized that you have a non-discharge portion data interpolating printing control means and a second sequence of printing carry out a newline. 4. In a multi-head printer such as Y, M, C and Bk (yellow, magenta, cyan and black), the normal ejection nozzle numbers of Y, M, C and Bk
AND detection means for obtaining the D condition, a first sequence of printing m consecutive normal ejection nozzles detected by the AND detection means as one normal nozzle, mdo
2. An ink jet color printer according to claim 1, further comprising a non-ejection portion data interpolation printing means comprising a second sequence in which a line feed of t is performed and printing is performed by m normal ejection nozzles.