JP3157881B2 - Ink jet recording device - 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 recording apparatus, and more particularly, to an ink-jet recording apparatus suitable for application to a color ink-jet printer or the like which performs color printing by receiving binary data.

[0002]

2. Description of the Related Art Conventionally, a serial recording type ink jet recording apparatus (inkjet printer) which performs recording while scanning a recording head having a plurality of ink ejection ports arranged in a direction (orthogonal direction) different from the arrangement direction is known. )It has been known. Then, in order to eliminate the streak of the seam of the image generated at each scan peculiar to such an ink jet printer, an arbitrary width of a certain scan (scan 1) and the next scan (scan 2) are overlapped, and the overlapped portion is formed. After the data of scan 1 is thinned out in a zigzag (or inverted zigzag) manner, recording is performed, and paper is fed by an amount such that the upper overlapped portion of scan 2 matches the lower overlapped portion of scan 1.
A method has been adopted in which the data of scan 2 of the superimposed portion is thinned out in an inversely staggered (or staggered) manner to perform recording.

[0003]

However, in such a conventional technique, printing (two-pass printing) is performed in two separate steps, so that the unevenness of the seam between the scans depending on the machine precision by the paper feed control system of the printer is obtained. Is considerably resolved compared to normal one-pass printing, but since the thinning pattern is fixed in a staggered or inverted staggered pattern, especially when printing high density areas, the regularity is reduced by 1/2 unit of one scan. There is a problem that uneven density unevenness occurs.

SUMMARY OF THE INVENTION An object of the present invention is to improve the elimination of line unevenness and density unevenness by the two-pass printing described above, and to realize uniform and high-quality image printing which does not depend on mechanical accuracy by a paper feed control system. It was done.

[0005]

According to the present invention, there is provided a scanning means for scanning a recording head having a plurality of ejection ports arranged relative to a recording medium in a first direction different from the arrangement direction; Transport means for transporting the print medium relative to the print head in a second direction different from the first direction by an amount smaller than the width of the arrangement range of the plurality of discharge ports; A data buffer for storing image data to be printed, and a data buffer for printing, respectively, in an ink jet printing apparatus that performs printing by performing the scanning a plurality of times at different relative positions in the second direction with respect to the printing medium. A template buffer that stores a plurality of thinning patterns for performing thinning processing on image data, and a plurality of irregular thinning patterns that can cover all image data to be recorded. A plurality of irregularities corresponding to the plurality of scans stored in the template buffer while reading out the image data from the data buffer a plurality of times with respect to a predetermined recording area recorded by the plurality of scans. Recording control means for decimating and recording the same image data read out a plurality of times based on a proper decimating pattern.

[0006]

According to the present invention, complementary and irregular thinning patterns are respectively stored in a plurality of template buffers, and image data read from the data buffer is thinned and recorded based on the thinning patterns. ing. Therefore, according to the present invention, the stripe unevenness in each scan which occurred during the one-pass printing is eliminated, and the uneven density in the particularly high density part caused by the two-pass printing by the staggered and inverted staggered printing is also eliminated. This is improved by the lack of regularity, and higher quality recording can be realized.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a preferred embodiment of the present invention.
An example of the configuration of a color ink jet recording apparatus including a recording head of a type having an electrothermal transducer corresponding to an ejection port for generating thermal energy that causes film boiling of ink as energy used for ink ejection. Show.

In FIG. 1, a recording medium 1 such as paper or a plastic sheet is supported by conveying rollers 2 and 3 composed of a pair of rollers disposed above and below a recording area, and is driven by a sheet feed motor 4. 2 is conveyed in the direction of arrow A. A guide shaft 5 is provided in front of the transport rollers 2 and 3 in parallel with the transport rollers.
The carriage 6 is reciprocated in the direction of arrow B via the wire 8 by the output of the carriage motor 7 along the guide shaft.

The carriage 6 has a recording head unit 9
0 is mounted. This recording head unit 90 is for color image formation, is arranged in the scanning direction, and is provided corresponding to each color ink of cyan (C), magenta (M), yellow (Y), and black (B _K ). The recording head 9 includes 9A, 9B, 9C and 9D. A plurality of (for example, 32, 64, or 128) ink ejection ports are arranged in a vertical line on the front surface of each recording head 9, that is, a surface facing the recording medium 1 at a predetermined interval (for example, 0.8 mm). Recording section is provided.

Each recording head 9 is mounted with a circuit board of a driving circuit (driver) 29 for driving as described above. A CPU serving as a recording control processing unit to be described later with reference to FIG. 2 and a control unit including a ROM, a RAM, an interface processing unit, various buffers, and the like provided on the CPU are formed on a control board 15. A command signal and a data signal (recording information) are received from a host device 14 such as a computer. Drive voltage (heat voltage).

An operation panel 160 attached to an outer case (not shown) of the recording apparatus includes an online / offline switching key 16A, a line feed key 16B, a form feed key 16C, and a key setting section such as a recording mode switching key 16D. And a display unit including warning lamps such as some alarm lamps 16E and power lamps 16F.

FIG. 2 is a block diagram showing a configuration example of a recording control system including the color ink jet printer shown in FIG. Hereinafter, each block illustrated will be described.

Reference numeral 102 denotes the color ink jet printer shown in FIG.
3, reception data buffer 104, reception data buffer 1
05, recording control processing unit 106, template buffer 1
07, 108, and a printer engine 109. In the reception data buffers 104 and 105 (hereinafter referred to as reception data buffer (1) and reception data buffer (2), respectively), data of dot lines × discharge ports to be printed now and printing after the printing are performed. Data for one dot line × discharge port is stored alternately. The print control processing unit 106 transfers the data stored in the reception data buffers (1) and (2) to the printer engine 109, and the width of half the width printed in one scan after one scan is completed. It performs sequence management such that only paper feed is executed, creates thinned data in the template buffer realized by this example, and masks print data according to the created thinned data. Specifically, it has a CPU for executing the processing procedure described later with reference to FIGS. 3 to 5, a ROM storing a program corresponding to the processing procedure, and the like. The template buffers 107 and 108 (hereinafter referred to as template buffers (A) and (B), respectively) are buffers provided to store data indicating a thinning pattern for masking data to be currently recorded. Further, the printer engine 109 includes a data recording processing unit 110 composed of parts 7 and 29 related to carriage movement or recording in FIG. 1 and a part 4 involved in conveyance of the recording medium 1.
And the like.
Reference numeral 112 denotes an interface cable for electrically connecting the host computer 14 and the color inkjet printer 102.

A sequence control algorithm for realizing the processing of this embodiment using the scan 1 receive data buffer 104, scan 2 receive data buffer 105, and template buffers 107 and 108 is shown in FIGS.
This will be described with reference to the flowchart shown in FIG.

In the following, in order to simplify the description,
It is assumed that a color ink jet printer in which a recording head 9 having 64 ink ejection ports vertically for each of four colors of yellow, magenta, cyan and black is mounted on a carriage.

First, in step S1 of FIG. 3, a printing operation for NULL data for 32 lines (a printing operation for non-ejection data, and no ejection is performed) is executed. This is an initial operation for alternately using a head having 64 ejection openings in the upper and lower parts of the head with 32 ejection openings in this example. Next, in step S2, it is confirmed whether or not there is received data in the data reception buffer (1). If data reception is detected, the process proceeds to step S3. If data reception is not detected, that is, the final data is received. When the process is completed, the process proceeds to step S24 in FIG. If data reception is detected in the data reception buffer (1), thinning pattern data for 32 lines is created in the template buffer (A) in step S3. Data having no regularity such as random numbers can be used as the thinning pattern data. The size of each of the template buffers (A) and (B) may be (1 line data length) × 32. Then, the template buffer (A),
The thinning pattern data stored in (B) corresponds to each dot of the received data of 32 lines to be recorded.

In step S4, the upper 32 lines of the reception data buffer (1) and the template buffer (A)
After performing a logical product operation (AND operation) on each of the corresponding bits to create thinned data, the printer engine 1
09 and transfer the created data to the lower part of each recording head (the lower 32 ejection ports). Next, in step S5, the paper is fed for 32 lines, and step S5 is executed.
In step 6, a logical NOT operation (NOT operation) is performed on all of the thinned data patterns created in step S3, and thinned pattern data for extracting the dots masked in step S4 is created in the template buffer (B). I do. Then, in step S7, using the thinning pattern data, a logical AND operation (AND operation) is performed on the upper 32 lines of the reception data buffer (1) and the corresponding bits of the template buffer (B) to generate thinned data. Then, the data is transferred to the printer engine, and the recording is performed using the upper portion (the upper 32 ejection ports) of each head.

Next, the above operation is performed on the lower 32 lines of the data reception buffer (1). That is, the process proceeds to step S8, in which new thinning pattern data for 32 lines is created in the template buffer (A). On the other hand, thinning data is created by performing a logical product operation (AND operation), the data is transferred to the printer engine 109, and printing is performed using the lower part of each head. And
In step S10, the paper is fed for 32 lines, in step S11 a logical NOT operation (NOT operation) is performed on all the thinned data patterns created in step S8, and in step S12, the lower part of the reception data buffer (1) is processed. After performing a logical product operation (AND operation) on the 32 lines and the corresponding bits of the template buffer (B) to generate thinned data, the data is transferred to the printer engine 109 and recorded using the upper part of each head. Is performed.

By the above operation, the recording of the data stored in the reception data buffer 1 is realized.

Hereinafter, similarly, the reception data buffer (2)
The processing of the data stored in is performed. That is, the process proceeds to step 13 to check whether or not the received data is present in the received data buffer (2). If the data reception is detected, the process proceeds to step S14. If the data reception is not detected, that is, the final data is deleted. Upon completion of the reception, the process proceeds to step S24 in FIG. If data reception is detected in the data reception buffer 2, in step S14, thinning pattern data for 32 new lines is created in the template buffer (A). As in the case of the reception data buffer (1) described above, in step S15, an AND operation is performed on the upper 32 lines of the reception data buffer (2) and each corresponding bit of the template buffer (A).
) To create thinned data, transfer the data to the printer engine 109, and print using the lower part of each print head. Then, step S16
After 32 lines of paper have been fed in step S17,
In step S14, thinning pattern data for taking out the masked dots by performing a logical NOT operation (NOT operation) on all of the thinning data patterns created in step S14, and using the thinning pattern data in step S18. After performing a logical product operation (AND operation) on the upper 32 lines of the receive data buffer 2 and the corresponding bits of the template buffer to create thinned data, the data is transferred to the printer engine 109, and the upper part of each head is processed. To record.

Next, the remaining reception data buffer (2)
In step S19, new 32 lines of thinned-out pattern data are created in the template buffer to print the lower 32 lines of the data receiving buffer (2). After performing a logical product operation (AND operation) to create thinned data, the printer engine 10
The data is transferred to the recording head 9, and recording is performed using the lower portion of each recording head. Then, after performing the paper feed for 32 lines in step S21, in step S22 a logical NOT operation (NOT operation) is performed on all of the thinned data patterns created in step S19 to extract the masked dots. Create thinning pattern data for
Using the thinning pattern data, a logical product operation (AND operation) is performed on the lower 32 lines of the receive data buffer 2 and each corresponding bit of the template buffer in step S23 to create thinned data, and then transferred to the printer engine 109. Then, recording is performed using the upper part of each recording head. Then, the process returns to step S2 to confirm the reception of data to the data reception buffer (1), thereby continuing the continuous data recording. Step S2
In step 4, a recording operation for NULL data for 32 lines is performed as a post-operation corresponding to step S1.

Next, referring to FIG. 6, the data received in the reception data buffer shown in steps S4, S7, S9, S12, S15, S18, S20 and S23 in FIGS. The operation of converting to data will be described. In the drawing, for simplification of description, one line in the main scanning direction is shown as being constituted by 40 dots.

FIG. 6A shows an example of data received by the reception data buffer (1) or (2).
(B) shows thinning pattern data which is an example of the contents of a template buffer (A) for mask processing;
(C) shows the contents of the template buffer (B), which is the inverted thinning pattern data.

First, the data received in the reception data buffer shown in FIG. 6A is subjected to mask processing by the thinning pattern data in the template buffer (A) shown in FIG. 6B, and is transferred to the printer engine 109. You.
The transferred data is the record print data (1) in FIG.
The dot configuration is represented by a white circle in the dot pattern shown in FIG. At the timing when the recording data (1) is transferred, NOT operation is performed on each dot of the thinned-out pattern data in the template buffer (A) shown in FIG. 6B, and a new template shown in FIG. Prepare a buffer.

The data in the reception data buffer shown in FIG. 9A is subjected to mask processing by the thinning pattern data in the template buffer (B) shown in FIG. The transferred data is the data indicated by the recording data (2) in FIG. 7E, and the dot configuration is represented by a black circle shown in the dot pattern in FIG. Thus, as shown in the dot configuration of FIG. 11F, all the dots of the received data can be covered, and it can be seen that there is no regularity of dots when the data is divided and recorded in 32 vertical dots twice. .

As is apparent from the above, according to the present embodiment, by performing printing in two passes, it is possible to eliminate streaking unevenness occurring at each scan, which is peculiar to an ink jet printer, and at the same time, thinning-out and zigzag thinning-out. Compared with the method realized by the method described above, since the configuration of the dots to be printed has no regularity, the density unevenness generated for each scan is improved, and higher-quality printing can be realized.

The present invention is not limited to the above embodiment, but can be variously modified.

For example, in the above example, thinning pattern data is created (steps S3, S8, S14, S19), and corresponding 32 lines are recorded (steps S4, S9, S1).
5, S20), creation of inverted thinning-out pattern data (steps S6, S11, S17, S22), and recording of 32 lines corresponding thereto (steps S7, S12, S1)
8, S23) in order, the recording control processing unit 10
If the inversion operation of the template buffer (A) can be performed by the command of the CPU provided in 6, the provision of the template buffer (B) is not necessarily required. However, if a procedure of simultaneously creating the thinned pattern data and its inverted data is adopted, it is effective to prepare two template buffers as shown in FIG.

Although the thinning pattern data is a random number in the above example, the range may be determined so as not to cause an extreme deviation. Further, a table storing a plurality of types of pattern data may be provided, and any one of the data may be read out at random and used. And if they are expanded in the template buffers (A) and (B), N
The OT operation need not be performed.

Further, in the above example, two-pass printing has been exemplified. However, n-pass printing of 3 ≦ n may be performed. In this case, n scans are performed so that all the dots of the received data can be covered by n scans. What is necessary is just to prepare pieces of thinning pattern data.

In addition, in the above example, the ejection openings of 64 dots are divided into upper and lower portions and used alternately for each scan. May be used simultaneously.

(Others) The present invention includes a means (for example, an electrothermal converter, a laser beam, or the like) for generating thermal energy as energy used for ink ejection, particularly in an ink jet recording system. An excellent effect is obtained in a recording head and a recording apparatus of a type in which the state of ink is changed by the thermal energy. This is because according to such a method, it is possible to achieve higher density and higher definition of recording.

The typical structure and principle are described in, for example, US Pat. Nos. 4,723,129 and 4,740.
It is preferable to use the basic principle disclosed in the specification of Japanese Patent No. 796. This method is a so-called on-demand type,
Although it can be applied to any type of continuous type, in particular, in the case of the on-demand type, it can be applied to a sheet holding liquid (ink) or an electrothermal converter arranged corresponding to the liquid path. By applying at least one drive signal corresponding to the recorded information and giving a rapid temperature rise exceeding the nucleate boiling, heat energy is generated in the electrothermal transducer, and film boiling occurs on the heat acting surface of the recording head. Liquid (ink) corresponding to this drive signal on a one-to-one basis.
This is effective because air bubbles inside can be formed. The liquid (ink) is ejected through the ejection opening by the growth and contraction of the bubble to form at least one droplet. When the drive signal is formed into a pulse shape, the growth and shrinkage of the bubble are performed immediately and appropriately, so that the ejection of a liquid (ink) having particularly excellent responsiveness can be achieved, which is more preferable. As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. Further, if the conditions described in US Pat. No. 4,313,124 relating to the temperature rise rate of the heat acting surface are adopted, more excellent recording can be performed.

As the configuration of the recording head, in addition to the combination of the discharge port, the liquid path, and the electrothermal converter (linear liquid flow path or right-angled liquid flow path) as disclosed in the above-mentioned respective specifications, U.S. Pat. No. 4,558,333 and U.S. Pat. No. 44,558 which disclose a configuration in which a heat acting portion is arranged in a bending region.
A configuration using the specification of Japanese Patent No. 59600 is also included in the present invention. In addition, Japanese Unexamined Patent Application Publication No. 59-123670 discloses a configuration in which a common slit is used as a discharge portion of an electrothermal converter for a plurality of electrothermal converters. The effect of the present invention is effective even if the configuration is based on JP-A-59-138461, which discloses a configuration corresponding to a discharge unit. That is, according to the present invention, recording can be reliably and efficiently performed regardless of the form of the recording head.

In addition, in the serial type printer as described above, a recording head fixed to the apparatus main body or an electric connection with the apparatus main body by being attached to the apparatus main body or a connection from the apparatus main body. The present invention is also effective when a replaceable chip-type print head capable of supplying ink or a cartridge-type print head in which an ink tank is provided integrally with the print head itself is used.

It is preferable to add ejection recovery means for the recording head, preliminary auxiliary means, and the like as the constitution of the recording apparatus of the present invention since the effects of the present invention can be further stabilized. If these are specifically mentioned, the recording head is heated using capping means, cleaning means, pressurizing or suction means, an electrothermal transducer, another heating element or a combination thereof. Pre-heating means for performing the pre-heating and pre-discharging means for performing the discharging other than the recording can be used.

The type and number of recording heads to be mounted are not limited to those provided only for one color ink, and for a plurality of inks having different recording colors and densities. A plurality may be provided. That is, for example, the printing mode of the printing apparatus is not limited to a printing mode of only a mainstream color such as black, but may be any of integrally forming a printing head or a combination of a plurality of printing heads. The present invention is also very effective for an apparatus provided with at least one of the recording modes of full color by color mixture.

In addition, in the embodiment of the present invention described above, the ink is described as a liquid. However, an ink which solidifies at room temperature or lower and which softens or liquefies at room temperature may be used. In general, the ink jet method generally controls the temperature of the ink itself within a range of 30 ° C. or more and 70 ° C. or less to control the temperature so that the viscosity of the ink is in a stable ejection range. Sometimes, the ink may be in a liquid state. In addition, in order to positively prevent temperature rise due to thermal energy by using it as energy for changing the state of the ink from a solid state to a liquid state, or to prevent evaporation of the ink, the ink is solidified in a standing state and heated. May be used. In any case, the application of heat energy causes the ink to be liquefied by the application of the heat energy according to the recording signal and the liquid ink to be ejected, or to start solidifying when it reaches the recording medium. The present invention is also applicable to a case where an ink having a property of liquefying for the first time is used. In such a case, the ink
JP-A-54-56847 or JP-A-60-7
As described in Japanese Patent Publication No. 1260, it is also possible to adopt a form in which the sheet is opposed to the electrothermal converter in a state where it is held as a liquid or solid substance in the concave portion or through hole of the porous sheet. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

In addition, the form of the ink jet recording apparatus of the present invention is not only used as an image output terminal of an information processing apparatus such as a computer, but also for a copying apparatus combined with a reader or the like, and a facsimile apparatus having a transmission / reception function. It may take a form.

[0041]

As described above, according to the present invention,
In addition to eliminating the line unevenness in each scan that occurred during one-pass printing, the unevenness in the density, particularly in the high-density portion, caused by the two-pass printing using the staggered and inverted zigzag methods has no dot alignment. This makes it possible to achieve higher quality recording.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing one embodiment of a color inkjet printer to which the present invention can be applied.

FIG. 2 is a block diagram illustrating a configuration of a control system including the color inkjet printer and a host computer illustrated in FIG.

FIG. 3 is a flowchart illustrating an example of a sequence control algorithm of a recording process according to the embodiment.

FIG. 4 is also a flowchart.

FIG. 5 is also a flowchart.

FIG. 6 is a transition diagram showing a print data mask process for supplementarily explaining the processes of FIGS. 3 to 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Recording medium 6 Carriage 9 Recording head 14 Host computer 102 Color inkjet printer 103 Interface processing part 104 Data reception buffer (1) 105 Data reception buffer (2) 106 Recording control processing part 107 Template buffer (A) 108 Template buffer (B) 109 Printer engine 110 Data recording processing unit 111 Paper feed processing unit 112 Interface cable

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-62-285074 (JP, A) JP-A-60-214670 (JP, A) JP-A-3-207665 (JP, A) JP-A-2- 134265 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) B41J 2/21 B41J 2/485

Claims (4)

(57) [Claims] A scanning unit configured to scan a recording medium having a plurality of ejection ports arranged relative to a recording medium in a first direction different from the arrangement direction, and an arrangement range of the plurality of ejection ports. Transport means for transporting the recording medium relative to the recording head in a second direction different from the first direction by an amount smaller than the width of the recording medium. In an ink jet printing apparatus for performing printing by performing the scanning a plurality of times at different relative positions in two directions, a data buffer for storing image data to be printed, and a thinning process for each image data to be printed. Duplication
An image to be recorded in all of the decimated patterns
And lutein Plates buffer to store a plurality of irregular thinning pattern which can cover the image data, for a given recording area recorded by the plurality of scans,
It reads a plurality of times the image data from the data buffer, the previously stored Kite Plates buffer
An ink jet recording apparatus comprising: recording control means for thinning out and recording the same image data read out a plurality of times based on a plurality of irregular thinning patterns corresponding to a plurality of scans . 2. A printing apparatus, comprising: a plurality of print heads corresponding to inks having different color tones; receiving binary image data and performing color printing of bitmap data; 2. The ink jet recording apparatus according to 1. 3. The apparatus according to claim 1, wherein the transporting unit transports a half of the width of the arrangement range, and scanning by the scanning unit is performed twice on the recording area.
3. The ink jet recording apparatus according to claim 1. 4. The recording head according to claim 1, further comprising an electrothermal transducer for generating thermal energy for causing film boiling of the ink, as an element for generating energy used for discharging the ink. Item 4. An ink jet recording apparatus according to any one of Items 1 to 3.