JPH10157135A - Recorder and control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recorder and a control method therefor in which uneven recording can be made inconspicuous without complicating the mechanism and the circuit. SOLUTION: First and second recording heads 601, 602 are arranged to constitute a pair of recording elements where two recording elements are arranged on a substantially identical record scanning line. The first and second recording heads 601, 602 perform scanning in the direction of record scanning line and form a visible image based on an image date stored in a VRAM 17. In this regard, a recording head control section 18 selects any one recording element for each pair of recording elements. Furthermore, a recording head control section 18 alters selection of a recording element being employed for image formation during single record scanning for image formation.

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 a control method thereof, and more particularly to an on-demand type ink jet recording apparatus for ejecting ink and recording only when necessary for recording characters and images, and an ink ejection control thereof. Things.

The present invention can be applied not only to an ink jet recording apparatus for recording on recording paper used in offices and the like, but also to an ink jet recording apparatus as a textile printing apparatus for recording on a cloth or the like. .

[0003]

2. Description of the Related Art Recording devices such as printers, copiers, and facsimile machines are configured to record an image composed of a dot pattern on a recording material such as paper, a plastic thin plate, or cloth based on image information. ing.

[0004] Such recording apparatuses can be classified into an ink jet type, a wire dot type, a thermal type, an electrophotographic type and the like according to the recording method. Among them, the ink jet type (ink jet printing device)
A recording liquid (ink) droplet is ejected from an ejection port of an ink jet recording head to eject and fly, and the recording liquid is adhered to a recording material, and recording is performed. It's being used.

[0005] Above all, a recording head of the type in which thermal energy is applied to ink to discharge ink droplets by utilizing pressure due to thermal expansion has a good response to a recording signal and it is easy to increase the density of discharge ports. There are advantages such as.

[0006] In addition, a method of ejecting ink using this thermal energy is a method in which an ejection port and an electro-thermal converter (ejection energy generating element) substantially correspond to the width of a recording material.
A full-line type recording head (full-line recording head) in which are arranged in a long line, and an ink jet recording apparatus using such a recording head are greatly expected to spread from the viewpoint of high speed.

However, in the above-described full-line recording head, unless all the droplets ejected from the ejection ports provided over the entire width of the recording area are made uniform.
There is a problem that recording unevenness occurs. Although the recording unevenness is difficult to recognize in a recording pattern having a low printing ratio such as a character, it is more conspicuous when the printing ratio is increased so as to continuously print the same pattern such as a halftone.

In order to solve such a problem, it is only necessary to produce a line head in which the amount of ejected droplets is uniform. However, in such a case, the production yield of the line head is largely reduced. , An increase in production costs is inevitable.

On the other hand, it is conceivable to prevent this type of recording unevenness even in a head having a non-uniform discharge droplet volume by providing a means for adjusting the energy applied to the heating element of each nozzle during ink discharge. Specifically, the volume of the ink droplet of each nozzle is measured in advance, and based on the value, a pulse of electric energy applied to the heating element of each nozzle so as to equalize the volume of the ink droplet to be discharged. Adjust the width.

[0010]

However, the volume of ink droplets discharged from each nozzle changes as the line head is used for a long time. Therefore, even if the volume of the ink droplets of each nozzle is adjusted to be appropriate at the time of manufacturing, the recording unevenness gradually becomes conspicuous. Also, by measuring the volume of ink droplets to be ejected, calculating a correction value for equalization, and correcting the ink ejection amount of each nozzle inside the printer, the volume of ink droplets to be ejected can be reduced. It is possible to keep it uniform over time. However, the volume of the ink droplets must be calibrated periodically, and the mechanism and the circuit of the printer for measuring the volume of the ink droplets are complicated, which inevitably increases the size and cost.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a recording apparatus which makes recording unevenness less noticeable without complicating a mechanism and a circuit, and a control method thereof.

Further, the present invention eliminates the need to periodically perform correction of the ejection amount of ink droplets for eliminating recording unevenness, particularly in an ink jet type recording apparatus, and makes recording without complicating the mechanism and circuit. It is an object of the present invention to provide a recording apparatus for reducing unevenness and a control method thereof.

[0013]

A recording apparatus according to the present invention for achieving the above object has the following arrangement. That is, a printing unit having a plurality of sets of printing element groups in which a plurality of printing elements are arranged on substantially the same printing scan line corresponding to a plurality of printing scan lines; Selecting means for selecting one of the recording elements, forming means for scanning the recording means in the recording scanning line direction, and forming a visible image using the recording element selected by the selecting means, and the forming means In one printing scan by
Changing means for changing the selection of the printing element by the selecting means.

Preferably, the recording means has a plurality of recording heads on which a plurality of recording elements corresponding to a plurality of recording scanning lines are arranged, and the plurality of recording heads constitute the recording element group. By arranging two or more recording heads, recording unevenness due to a single recording head can be mutually compensated, and the present invention can be implemented more easily.

Preferably, the changing means changes the selection of the printing element by the selecting means for each pixel row in the printing scan. The spatial frequency of the recorded image is improved, and the recording unevenness can be made less noticeable.

Preferably, the changing means changes the selection of the printing element by the selecting means by regularly switching a predetermined selection pattern.

Preferably, the changing means changes the selection of the printing elements so that the printing elements of the same printing head are not continuous in the printing scanning direction and the direction perpendicular thereto. This is because a higher spatial frequency is achieved.

Preferably, the changing means determines the selection of the recording element by the selecting means based on a random number.

Preferably, the recording head is a line ink jet head including a plurality of ink ejection ports and a substrate provided with a plurality of energy generating elements for the plurality of ejection ports. This is because by applying the present invention to a line inkjet head having a large number of recording elements, the effects of the present invention can be more remarkably enjoyed.

Preferably, the line ink jet head is provided for each of a plurality of inks, and each line ink head has a plurality of line ink jet heads. This is because color recording can be supported.

According to the control method of a printing apparatus of the present invention for achieving the above object, a printing element group in which a plurality of printing elements are arranged on substantially the same printing scanning line is provided in correspondence with the plurality of printing scanning lines. A printing step having a plurality of sets, a selecting step of selecting one of a plurality of printing elements in each of the plurality of sets of printing element groups, and scanning the printing step in the printing scan line direction, and selecting in the selecting step And a changing step of changing the selection of the printing element in the selecting step in one printing scan in the forming step.

[0022]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a perspective view schematically showing the full-line type ink jet head according to the present embodiment. In the figure, 128 discharge energy generating elements 130 are provided at a density of 400 dpi on element substrates 100 to 124 made of silicon. The twenty-five element substrates 100 to 124 are accurately fixed to a metal support 300 with an adhesive or the like. The wiring substrate 400 is bonded and fixed to the support 300 in the same manner as the element substrates 100 to 124. At this time, the pads 131 on the element substrates 100 to 124 and the signal / power supply pads 401 provided on the wiring substrate 400 are bonded and fixed in a predetermined positional relationship.

The top plate 200 is provided with the ejection energy generating element 13.
3200 flow channel grooves (1
28 × 25, print width 203.2 mm), 3200 discharge ports 201 corresponding to each flow channel,
124 is press-fitted and fixed by a spring member (not shown).

FIG. 2 is a schematic diagram of the ink jet recording apparatus according to the present embodiment using the full line type ink jet head of FIG. In a full-line inkjet recording apparatus, orifices from which recording liquid is ejected are arranged in a width corresponding to the recording width of a recording medium. In FIG.
Reference numerals 01 and 602 denote the full-line type ink jet heads (hereinafter, referred to as a first recording head 601 and a second recording head 602) described with reference to FIG. Be placed.

Ink is ejected from the first and second recording heads 601 and 602 toward a recording medium 800 such as paper or cloth conveyed by recording medium conveying rollers 700 and 701, and has the same printing width as the line inkjet head. A record of the width is made. The first recording head 601 and the second recording head 602 have the same number of nozzles at the same pitch, are arranged at intervals of a predetermined number of lines in the sub-scanning direction, and each nozzle is located on the same main scanning line. It is arranged so that it may line up. Therefore, it is possible to mix the recording pixels of the first recording head 601 and the recording pixels of the second recording head 602 in the image of one sub-scanning direction line.

FIG. 3 is a block diagram showing a schematic control configuration of the ink jet recording apparatus of this embodiment. In FIG. 1, reference numeral 11 denotes a CPU, which performs various controls of the present inkjet recording apparatus. A ROM 12 stores various control programs executed by the CPU 11. 13 is RA
M, which provides a work area when the CPU 11 executes various controls. An interface 14 is connected to an external device such as a host computer, and inputs print data and the like.

Reference numeral 15 denotes a recording system control unit, which performs recording on a recording medium using image data obtained based on print data and the like input via the interface 14. In the recording system control unit 15, the VRAM 17 stores the CPU 11
Stores the image data obtained by expanding the print data. The recording head control unit 18 performs printing based on image data using the first recording head 601 and the second recording head 602. Here, by mixing the drawing by the first recording head 601 and the second recording head 602, the recording unevenness that is conspicuous with a single recording head is made inconspicuous (details will be described later).

Reference numeral 16 denotes a transport system control unit, which controls the driving of the recording medium transport rollers 700 and 701 according to an instruction from the CPU 11.

FIG. 4 shows the recording head controller 18 of this embodiment.
FIG. 3 is a block diagram showing a detailed configuration of FIG. Reference numeral 181 denotes a mask circuit, which includes a first mask circuit 181a and a second mask circuit 181b. Mask data is supplied from the CPU 11 to the mask circuit 181, and the mask data is set in the first mask circuit 181 a according to the shared mask data. Each bit of the mask data corresponds to each nozzle of the print head, which is equivalent to prohibiting the use of a nozzle having a bit value of “0”.

The logical inversion value of the mask data set in the first mask circuit 181a is set in the second mask circuit 181b. Therefore, the portion of the first recording head 601 corresponding to the nozzle whose use is prohibited is recorded by the nozzle of the second recording head 602.

Reference numeral 182 denotes a line memory which receives data from the first mask circuit 181a,
01 is stored for one recording line. Reference numeral 183 denotes a line delay unit which receives data from the second mask circuit 181b and outputs the data to the first print head 601 and the second print head 6.
A delay corresponding to the number of lines corresponding to a physical interval from the line 02 is performed. 184 is a line memory, and the second recording head 60
2 stores data for one line.

185 and 186 are head drivers,
The first and second recording heads 601 and 602 are driven based on the data stored in the line memories 182 and 184, respectively.

Hereinafter, the cause of the occurrence of uneven recording and the recording control according to the present embodiment will be described in more detail.

First, the general appearance (conspicuousness) of uneven recording will be described with reference to FIGS. 5 (A), 5 (B) and 5 (C). FIG. 5A shows the distribution of OD (density when printed on recording paper) of a print made on a recording medium using a normal line inkjet head. Here O
Although D is used, there is a correlation between the discharge volume and the OD,
It is determined by the recording medium and the recording liquid. Now, in most cases, the OD distribution can be approximated to a sinusoidal curve. FIG. 5 (A)
Fig. 5 shows an approximation of the OD distribution of the sine wave (uneven wave).
(B). Here, the spatial frequency F = 1 / λ (λ is the wavelength of the uneven wave). The wavelength λ and ΔOD obtained here
(The average difference from the OD average) greatly affects the appearance (conspicuousness) of uneven recording. FIG. 5C shows a general relationship between the frequency of the uneven wave curve and the appearance of the uneven recording with respect to ΔOD. From this graph, it can be seen that from the point where the spatial frequency F exceeds 0.8 to 1.0, as the F becomes higher, that is, as the undulation becomes smaller than the large undulation, the recording unevenness becomes less noticeable.

In the present embodiment, an image in which unevenness is not noticeable is formed by utilizing the characteristic of the unevenness as described above. That is, in the present embodiment,
It is characterized in that the recording unevenness is made invisible or inconspicuous by reducing ΔOD and increasing the spatial frequency.

FIG. 6 is a schematic diagram showing which head nozzle is selected when printing is performed using the ink jet recording apparatus of this embodiment. The recording pattern shown in the drawing is a pattern with a recording rate of 100%. Here, H represents a discharge port from which the average droplet volume of the first and second recording heads 601 and 602 can be discharged, and h represents the first and second recording heads 60.
It represents a discharge port for discharging a droplet volume out of the average droplet volume of 1,602. A and B are the first and second, respectively.
The landing positions of the droplets ejected from the ejection ports H of the recording heads 601 and 602 are shown, and a and b represent the impact positions of the droplets ejected from the ejection ports h of the first and second recording heads 601 and 602, respectively. Represent. Therefore, the droplets a and b after landing indicate droplets after landing which are out of the average droplet volume.
The nozzles to be ejected onto the recording medium are selected by alternately arranging the droplets ejected from the first recording head 601 and the second recording head 602 in the main scanning direction. This gives Δ
It is possible to reduce the OD and increase the spatial frequency.

FIG. 7 shows a control procedure for performing the above-described recording. It should be noted that a control program for realizing the control shown in the flowchart of FIG.
This is executed by the PU 11.

First, in step S11, mask data is set in the mask circuit 181. In the example of FIG.
Since the first and second print heads are used as shown in the (1) -th column, the mask data set in the first mask circuit 181a is “00101111”, and the second mask circuit 1
The mask data set in 81b is “1101000
0 ".

In step S12, the process waits until the image data for one recording line subjected to the mask processing is held in the line memory 182 and the line delay unit 183, respectively. When the data is held, the process proceeds to step S13, and it is determined whether there is a next line to be recorded. here,
If there is a next line, the flow advances to step S14 to update the mask data. For example, to perform masking as shown in the (2) -th column in FIG. 6, the mask data set in the first mask circuit 181a is set to “11010000”.

On the other hand, if the next line does not exist, it is determined that the recording of the page has been completed, and steps S 13 to S
Proceed to 15. In step S15, it is determined whether there is a next page to be recorded. If there is a next page, the process returns to step S11 and repeats the above-described processing. Also,
If there is no next page in step S15, the process ends.

As described above, the recording as shown in FIG. 6 can be performed. FIG. 8 is a diagram illustrating an example of a recorded image by a general recording device. FIG. 9 is a diagram illustrating the effect of the recording process according to the present embodiment. FIG. 10 is a diagram showing a configuration of an image forming apparatus using a general full-line type inkjet head.

FIGS. 8 and 9 show recorded images for confirming the effect of the present embodiment when actually observed by eyes.
Note that the recording pattern has a recording rate of
This is a 0% halftone pattern. FIG. 8 is a diagram showing a general one full-line inkjet head 6 shown in FIG.
5 shows a recorded image when printed at 00. FIG. 9 is a recorded image in the case where two line inkjet heads according to the present embodiment are arranged in parallel and printing is performed by the above-described control. Line inkjet head 60 in FIG.
The ΔOD variation of 1,602 is equivalent to the line inkjet head 600 of FIG.

Comparing FIG. 8 with FIG. 9, it is clear that white streaks are noticeable in FIG. 8, but in FIG. 9, they are eliminated. In this way, by arranging two heads having the same ΔOD variation, it is possible to make the recording unevenness less noticeable. Further, by adopting the configuration of the present embodiment, effects such as an increase in printing speed and an increase in the service life of the head can be obtained.

In this embodiment, two line inkjet heads are arranged in parallel. However, three or more line inkjet heads can of course be arranged, and the effect on recording unevenness is further improved. In this embodiment, the line inkjet head has a nozzle density of 400 dpi.
The higher the nozzle density, such as 1200 dpi, the greater the effect on recording unevenness.

FIG. 11 is a schematic view of another embodiment using another method for selecting a nozzle from the first recording head 601 and the second recording head 602. The recording pattern is the same recording rate 100% pattern as the previous embodiment,
The meanings of H, h, A, B, a, and b are the same as in the above embodiment. Here, nozzle selection on the recording medium is alternately performed in the main scanning direction, and also alternately in a direction perpendicular to the main scanning direction (sub scanning direction). By selecting the nozzles in this manner, when the OD variation of the recording head is not independent for each nozzle but has a large undulation, it is very effective to eliminate the recording unevenness. . Further, the regularity in selecting the nozzle is not limited to the method described in the embodiments up to now, and it is possible to make a selection based on various regularities.

FIG. 12 shows the first recording head 601 and the second recording head 601.
FIG. 13 is a diagram illustrating another method of selecting a nozzle from the recording head 602. In FIG. 12, nozzles are selected at random.
Further, the recording pattern has the same recording rate of 100 as the previous embodiment.
%, And the meanings of H, h, A, B, a, and b are the same as in the previous embodiment. For example, when comparing the odd-numbered nozzle group and the even-numbered nozzle group, there is a tendency in the droplet volume,
Random nozzle selection as shown in FIG. 12 is extremely effective.

As a method for selecting a random nozzle, there is a method for selecting a nozzle using a random number. As for the random numbers to be used, a random number table may be stored in the ROM 12.

Also, in the recording apparatus described so far, the type and number of line ink jet recording heads to be mounted have been described with only one single color ink. However, a plurality of inks having different recording colors and densities are applicable. A plurality may be provided. That is, the present invention can be naturally applied to a color recording apparatus equipped with a plurality of heads corresponding to a plurality of color inks. In addition, in the embodiment described above, the ink is described as a liquid, but an ink that solidifies at room temperature or below and that softens or liquefies at room temperature may be used. Alternatively, in the ink jet method, the temperature of the ink itself is generally controlled 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. May be in a liquid state. In addition, ink that solidifies in a standing state and liquefies by heating may be used.

Further, in the present invention, a printing apparatus, a printing apparatus and a pre-processing apparatus, which are particularly required to have a long recording head,
A printing system incorporating a post-processing device can provide a long length without printing unevenness, and can provide a printing device and a system capable of recording with high definition and high image quality.

Although the full-line type ink jet head has been described in the above embodiment, the present invention is also applicable to an ink jet type printer in which a recording sheet is conveyed in the sub-scanning direction and the recording head is operated in the main scanning direction. It is possible to apply the present invention.

Further, in the above embodiment, the description has been made by applying the ink jet type printer device. However, it is obvious that the present invention can be applied to other types of print heads, for example, a thermal type print head. .

It should be noted that the present invention provides an excellent effect particularly in an ink jet recording head and a recording apparatus in which a flying liquid droplet is formed by utilizing thermal energy and recording is performed among ink jet recording methods.

The typical configuration 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 can be applied to both the so-called on-demand type and continuous type. In particular, in the case of the on-demand type, liquid (ink)
By applying at least one drive signal corresponding to the recorded information and providing a rapid temperature rise exceeding the nucleate boiling to an electrothermal transducer arranged corresponding to the sheet or the liquid path holding the Since thermal energy is generated in the electrothermal transducer and film boiling occurs on the heat-acting surface of the recording head, bubbles in the liquid (ink) corresponding to this drive signal on a one-to-one basis can be formed. It is valid. By discharging the liquid (ink) through the discharge opening by the growth and contraction of the bubble, at least one droplet is formed. 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 the liquid (ink) having particularly excellent responsiveness can be achieved, which is more preferable.

As the drive signal in the form of a pulse, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. When the conditions described in US Pat. No. 4,313,124 of the invention relating to the temperature rise rate of the heat acting surface are adopted, 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, A configuration using U.S. Pat. No. 4,558,333 or U.S. Pat. No. 4,459,600 which discloses a configuration in which the heat acting surface is arranged in a bent region may be used. In addition, Japanese Patent Laid-Open Publication No. Sho 5 discloses a configuration in which a common slit is used as a discharge section of an electrothermal converter for a plurality of electrothermal converters.
Japanese Unexamined Patent Publication No. 9-123670 discloses a structure in which an opening for absorbing a pressure wave of thermal energy corresponds to a discharge portion.
A configuration based on JP-A-9-138461 can also be adopted.

Further, as a full-line type recording head having a length corresponding to the width of the maximum recording medium that can be recorded by the recording apparatus, the length is determined by combining a plurality of recording heads as disclosed in the above specification. This may be either a configuration satisfying the above requirements or a configuration as a single recording head formed integrally.

In addition, the print head is replaceable with a print head of a replaceable chip type, which can be electrically connected to the main body of the apparatus or supplied with ink from the main body of the apparatus, or is integrated with the print head itself. Alternatively, a cartridge type recording head provided with an ink tank may be used.

It is preferable to add recovery means for the print head, preliminary auxiliary means, and the like provided as components of the printing apparatus of the present invention since the effects of the present invention can be further stabilized. . If these are specifically mentioned, capping means for the recording head, cleaning means, pressurizing or suction means, preheating means using an electrothermal transducer or another heating element or a combination thereof, and printing Performing a preliminary ejection mode for performing another ejection is also effective for performing stable printing.

Further, the recording mode of the recording apparatus is not limited to the recording mode of only the mainstream color such as black, but may be a single recording head or a combination of a plurality of recording heads. Alternatively, the apparatus may be provided with at least one of full colors by color mixture.

In the embodiments 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 at room temperature or is liquid, In general, in the ink jet system, the temperature of the ink itself is controlled 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. It is sufficient if the ink is in a liquid state.

In addition, the temperature rise due to thermal energy can be positively prevented by using it as energy for changing the state of the ink from a solid state to a liquid state, or solidified in a standing state to prevent evaporation of the ink. Either ink may be used, or in any case, the ink may be liquefied by application of heat energy according to the recording signal and ejected as a liquid ink, or may already start to solidify when reaching the recording medium. The use of ink having a property of being liquefied for the first time by heat energy is also applicable to the present invention. In such a case, the ink is disclosed in JP-A-54-5684.
No. 7 or Japanese Patent Application Laid-Open No. 60-71260, in which the porous sheet is opposed to the electrothermal converter while being held in a liquid or solid state in the concave portions or through holes of the porous sheet. It may be. 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 to the above, the recording apparatus according to the present invention may be combined with a reader or the like in addition to the one provided as an image output terminal of an information processing device such as a word processor or a computer as described above. It may take the form of a copier, or a facsimile machine having a transmission / reception function.

As described above, according to the present embodiment, by arranging a plurality of line ink jet heads in parallel, calibration for eliminating recording unevenness is not performed periodically, and the mechanism and circuit of the printer are simplified. It is possible to eliminate recording unevenness or to make it inconspicuous without significantly complicating the recording. Further, it is unlikely that the discharge amounts of the two nozzles arranged in parallel change over time in the same manner. Therefore, even if the discharge amount of each nozzle changes over time, unevenness and conspicuousness can be suppressed.

Even if the present invention is applied to a system composed of a plurality of devices (for example, a host computer, an interface device, a reader, a printer, etc.), an apparatus (for example, a copying machine, a facsimile, etc.) comprising one device Device).

Further, an object of the present invention is to supply a storage medium storing a program code of software for realizing the functions of the above-described embodiments to a system or an apparatus, and to provide a computer (or CPU) of the system or the apparatus.
And MPU) read and execute the program code stored in the storage medium.

In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiment, and the storage medium storing the program code constitutes the present invention.

As a storage medium for supplying the program code, for example, a floppy disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD
-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.

When the computer executes the readout program code, not only the functions of the above-described embodiment are realized, but also the OS (Operating System) running on the computer based on the instruction of the program code. ) May perform some or all of the actual processing, and the processing may realize the functions of the above-described embodiments.

Further, after the program code read from the storage medium is written into a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, based on the instruction of the program code, It goes without saying that the CPU included in the function expansion board or the function expansion unit performs part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.

[0071]

As described above, according to the present invention,
The recording unevenness can be made inconspicuous without complicating the mechanism and the circuit.

Further, according to the present invention, it is unnecessary to periodically correct the ejection amount of ink droplets for eliminating recording unevenness, particularly in an ink jet recording apparatus, without complicating the mechanism and circuit. This makes it possible to make the recording unevenness inconspicuous.

[0073]

[Brief description of the drawings]

FIG. 1 is a perspective view schematically illustrating a full-line type inkjet head according to an embodiment.

FIG. 2 is a schematic diagram of the inkjet recording apparatus according to the present embodiment using the full-line inkjet head of FIG.

FIG. 3 is a block diagram illustrating a schematic control configuration of the inkjet recording apparatus according to the embodiment.

FIG. 4 is a block diagram illustrating a detailed configuration of a printhead controller 18 according to the embodiment.

FIG. 5 is a diagram for explaining how recording unevenness looks (appears).

FIG. 6 is a schematic diagram showing which head nozzle is selected when printing is performed using the inkjet recording apparatus of the embodiment.

FIG. 7 is a flowchart illustrating a control procedure according to the embodiment.

FIG. 8 is a diagram illustrating an example of an image recorded by a general recording apparatus.

FIG. 9 is a diagram illustrating the effect of the recording process according to the embodiment.

FIG. 10 is a diagram illustrating a configuration of an image forming apparatus using a general full-line type inkjet head.

FIG. 11 is a schematic diagram illustrating another method for selecting a nozzle from a first print head and a second print head.

FIG. 12 is a schematic diagram illustrating still another method for selecting a nozzle from a first recording head and a second recording head.

Claims (12)

[Claims] 1. A printing means having a plurality of printing element groups each having a plurality of printing elements arranged on substantially the same printing scanning line corresponding to a plurality of printing scanning lines, and each of the plurality of printing element groups. A selecting means for selecting one of a plurality of recording elements, and a forming means for scanning the recording means in the recording scanning line direction and forming a visible image using the recording elements selected by the selecting means, A printing apparatus, comprising: changing means for changing the selection of a printing element by the selecting means in one printing scan by the forming means. 2. The printing apparatus according to claim 1, wherein the printing unit includes a plurality of printing heads on which a plurality of printing elements corresponding to a plurality of printing scanning lines are arranged, and the plurality of printing heads constitute the printing element group. The recording device according to claim 1, wherein 3. The printing apparatus according to claim 1, wherein the changing unit changes the selection of the printing element by the selecting unit for each pixel row in the printing scan. 4. The printing apparatus according to claim 1, wherein the changing unit changes the selection of the printing element by the selecting unit by regularly switching a predetermined selection pattern.
The recording device according to any one of the above. 5. The printing apparatus according to claim 2, wherein the changing unit changes the selection of the printing elements so that the printing elements of the same printing head are not continuous in the printing scanning direction and the direction perpendicular thereto. 6. The printing apparatus according to claim 1, wherein the changing unit determines the selection of the printing element by the selecting unit based on a random number. 7. The recording apparatus according to claim 2, wherein the recording head is an inkjet recording head that performs recording by discharging ink. 8. The recording head according to claim 1, wherein the recording head ejects ink by using thermal energy, and is an ink jet recording head including a thermal energy converter for generating thermal energy to be applied to the ink. The recording device according to claim 7, wherein: 9. The recording head according to claim 1, wherein a state change is caused in the ink by thermal energy applied by the thermal energy converter, and the ink is ejected from an ejection port based on the state change. Claim 8
The recording device according to claim 1. 10. The recording head is a line ink jet head comprising a plurality of ink ejection ports and a substrate provided with a plurality of energy generating elements for the plurality of ejection ports. 3. The recording apparatus according to claim 2, wherein 11. The recording apparatus according to claim 11, wherein said line inkjet head is provided for each of a plurality of inks, and has a plurality of line inkjet heads for each ink head. 12. A printing step in which a plurality of printing element groups in which a plurality of printing elements are arranged on substantially the same printing scanning line correspond to a plurality of printing scanning lines, and each of the plurality of printing element groups is provided. A selecting step of selecting one of a plurality of printing elements, and a forming step of scanning the printing step in the printing scan line direction and forming a visible image using the printing elements selected in the selecting step. And a changing step of changing the selection of the printing element in the selecting step in one printing scan in the forming step.