JPH0899407A - Recording device and recording method - Google Patents

Abstract

PURPOSE: To realize high resolution print by a method wherein unrefined feeling developed due to regular dot controlling is reduced by being changed to the desired range under the state that the reduction of the load applied to a CPU is realized during the execution of the regular dot controlling. CONSTITUTION: Functional values, which are calculated in advance for regularly modulating the dot diameter, are stored in the form of tables in a RAM230. When necessary, the functional values are fetched from the RAM230 to a gate array 200. The gate array 200 has a PWM table 228, in every table number of which equal discharge modulation width is set to be realized so as to execute the regular dot diameter controlling by adding the functional values fetched from a functional table 231 to a fundamental driving table number, which is set in advance by optimal timing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus and a recording method for recording an image by forming dots on a recording medium. More specifically, the present invention relates to a recording apparatus and a recording apparatus for improving the quality of an output image. Regarding recording method.

[0002]

2. Description of the Related Art A recording device such as a printer, a copying machine or a facsimile is constructed to record an image consisting of a dot pattern on a recording material such as paper, a plastic thin film or cloth based on image information. Such recording devices are classified into ink jet type, wire dot type, thermal type, laser beam type, etc. according to the recording system, but in recent years, these devices have the advantages of high speed, high resolution, high image quality and low noise. The demand is increasing. An ink jet type recording apparatus can be cited as a recording apparatus which meets such a demand. The inkjet recording apparatus is configured to eject ink (recording liquid) droplets from the ejection port of the recording head and attach the droplets to a recording material for recording, and eject the ink from the recording head to perform recording. Since printing can be performed without contact with the recording material when performing, a very stable recorded image can be obtained.

[0003]

However, since the ink which is a fluid is used in the ink jet type recording system, various hydrodynamic phenomena occur in the recording head, which adversely affects the printing. Further, the viscosity and surface tension of the ink constantly fluctuate due to changes in the environmental temperature and the time of leaving the ink which causes evaporation of the ink. For example, even if the discharge amount is normal in the initial state, the discharge amount may fluctuate due to an increase or decrease in the environmental temperature and an increase in the negative pressure due to a decrease in the ink remaining amount in the ink tank. In addition, turbulent flow and laminar flow caused by the flow of ink that has the property of a continuous body,
It affects the surrounding ink flow and induces fluctuations in the ink ejection volume.

Such a change or variation in the ejection amount causes unevenness of a recorded image, particularly in a method of recording by heating and ejecting ink. The main causes are
The following are listed. 1) Variation in resistance value of the ejection heater, that is, variation in heat generation temperature when the ejection heater is driven causes variation in bubble length of ink in the ink. The variation in the bubble length of the ink in this ink causes the ink ejection amount and the ejection speed to vary, and causes the dot area and the dot shape to vary when the image is formed by the recording head, causing unevenness on the recorded image. .

2) The surface condition of the heater varies due to the surface properties of the heater and minute irregularities due to contamination with foreign matter, and the variation of the foaming start point at the ink-foaming start stage, that is, the variation of the foaming start time causes the dot shape. And make a difference. 3) Variations in the shape and diameter of the ejection ports of the recording head cause variations in the ejection direction and ejection amount, causing unevenness on the image.

4) The difference between the heater position and the nozzle position results in a difference in impedance between the ejection direction and the ejection direction when bubbles are generated, and this difference causes a difference in conversion efficiency for conversion into ejection energy when bubbles are generated. This causes a difference in discharge amount and discharge speed, causing unevenness on the image. 5) The endurance variation such as the wetting property between the nozzle constituent elements and the ink and the change in energy conversion efficiency depending on the frequency of use change the ejection characteristics for each nozzle. That is, since there is a difference in the dot diameter and the position where the dots are formed between the nozzles that are frequently used and the nozzles that are frequently used, unevenness occurs over time on the recorded image.

The cause of these image unevenness is
It is very difficult to control in view of both factors over time. Further, a recording head having a plurality of nozzles cannot eject ink from all the nozzles at the same time, and is configured to form a plurality of coherent nozzle groups and eject them simultaneously for each nozzle group. Therefore, the ink ejection state changes due to the voltage fluctuation in the nozzle group due to the image signal, the change in the ink flow velocity distribution, and the like, and the ink ejection amount also changes.

On the other hand, in printers for forming monochrome and color images, various stability such as dot reproducibility, density stability, gradation reproducibility and color reproducibility is desired. Although the discharge amount and the drive control method are also used, satisfactory results have not been obtained. The present invention has been made in view of the above-mentioned conventional example, and it is an object of the present invention to suppress density unevenness at the time of 1.1-pass printing and realize high quality output images.

2. It is an object of the present invention to realize high quality output images in response to changes in the ejection characteristics of the head over time. 3. It is an object of the present invention to realize a high quality output image in response to a change in the nozzle state of the head or a dynamic change in the ejection amount that constantly changes due to a change in driving conditions. 4. An object of the present invention is to prevent the deterioration of the image quality due to the noise of the output image and realize the high quality of the output image.

5. When achieving high quality output images, C
An object of the present invention is to reduce the load on the PU and prevent the image output speed from slowing down. It is an object of the present invention to provide a recording apparatus that achieves the objects of 6.1 to 5.

[0011]

In order to achieve the above object, the recording apparatus of the present invention has the following constitution. A recording device for forming a recorded image using a recording head having a plurality of recording elements for forming dots on a recording medium, comprising: first storage means for storing information designating a dot diameter to be recorded; and a plurality of dot diameters. For storing control information for generating
Recording comprising storage means and forming means for obtaining control information from the second storage means based on information sequentially read from the first storage means to form dots on a recording medium Depends on the device.

A recording apparatus for forming a recorded image using a recording head having a plurality of recording elements for forming dots on a recording medium, the means for reading the temperature of the nozzle and the information for designating the dot diameter to be recorded. , A second storage means for storing control information for generating a plurality of dot diameters, a third storage means for storing information for correcting dots based on the temperature of the nozzle, and the third storage means. 1st and 3rd
According to another aspect of the present invention, there is provided a recording apparatus including: a control unit that acquires control information from the second storage unit based on information sequentially read from the storage unit and forms a dot on a recording medium.

Further, the recording control method according to the present invention for achieving the above object has the following configuration. That is, in a recording method for forming a recorded image using a recording head having a plurality of nozzles for forming dots on a recording medium, a trigger pulse is input to the gate array, and the gate array refers to the basic drive pulse at that time. The heating condition for the heat signal line is set so that the discharge amount of each nozzle periodically changes with respect to the standard discharge amount of ink when driven by the basic drive pulse, and the drive pulse is set with the set heat condition. It is a recording method characterized by being transmitted.

[0014]

In the above structure, the first storage means stores the information for designating the dot diameter in the order of change, and the third storage means stores the information for correcting the dots based on the temperature of the nozzle. ing. The information stored in the first and third storage means is read, control information for forming a corresponding dot diameter is obtained from the second storage means based on this information, and dots are formed according to the control information. .

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings. (Embodiment 1) In this embodiment, a thermal ink jet method is adopted as a recording method. The structure of the ink jet printer (IJRA) using the above method, the structure of the recording head, and the dot area modulation method will be described below.
The image forming method of this embodiment will be described.

FIG. 1 is an external perspective view showing the outline of the configuration of an ink jet printer IJRA which is a typical embodiment of the present invention. In FIG. 1, the spiral groove 50 of the lead screw 5005 that rotates via the driving force transmission gears 5011 and 5009 in conjunction with the forward / reverse rotation of the drive motor 5013.
The carriage HC engaging with 04 is a pin (not shown)
And is reciprocated in the directions of arrows a and b. An inkjet cartridge IJC is mounted on the carriage HC. A paper pressing plate 5002 presses the paper against the platen 5000 in the moving direction of the carriage. Reference numerals 5007 and 5008 denote photocouplers, which are home position detecting means for confirming the presence of the carriage lever 5006 in this area and switching the rotation direction of the motor 5013. Reference numeral 5016 is a member that supports a cap member 5022 that caps the front surface of the recording head, and 5015 is suction means that sucks the inside of the cap.
The suction recovery of the recording head is performed through the opening 5023 in the cap. 5017 is a cleaning blade, 5019
Is a member that allows this blade to move in the front-rear direction, and these are supported by the main body support plate 5018. Needless to say, a well-known cleaning blade can be applied to this example instead of this form. Also, 501
Reference numeral 2 denotes a lever for starting suction for suction recovery, which moves with the movement of the cam 5020 that engages with the carriage,
Movement of the driving force from the driving motor is controlled by known transmission means such as clutch switching.

The capping, cleaning, and suction recovery are configured so that the desired processing can be performed at their corresponding positions by the action of the lead screw 5005 when the carriage comes to the area on the home position side. As long as the desired operation is performed at the timing, any of the above can be applied to this example. FIG. 2 shows the configuration of the recording head IJU of the inkjet recording apparatus used in this embodiment. The inkjet recording head IJU is a recording head of a type that performs recording by using an electrothermal converter that generates thermal energy for causing film boiling in ink according to an electric signal.

In FIG. 2, reference numeral 100 denotes an electrothermal converter (ejection heater) arranged in a plurality of rows on a Si substrate, and electric wiring such as A1 for supplying electric power to the electrothermal converter, which is formed by a film forming technique. It is a heater board. Reference numeral 200 is a wiring board for the heater board 100.
A wire corresponding to the wire 00 (connected by wire bonding, for example) and a pad 201 located at an end of the wire and receiving an electric signal from the main body device.

Reference numeral 1300 denotes a grooved top plate provided with a partition wall and a common liquid chamber for partitioning a plurality of ink flow paths, and an ink receiving port 1500 for receiving the ink supplied from the ink tank and introducing it into the common liquid chamber. And an orifice plate 400 having a plurality of discharge ports are integrally molded. Polysulfone is preferable as the integral molding material, but other forming resin materials may be used.

Reference numeral 300 denotes, for example, a metallic support member that supports the back surface of the wiring substrate 200 on a flat surface and serves as a bottom plate of the ink jet unit. Reference numeral 500 denotes a holding spring, which has an M-shape and presses the common liquid chamber at the center of the M-shape and presses a part of the liquid passage with a linear pressure by the front salient 501. Heater board 1
00 and the top plate 1300 are pressed, and the foot portion of the spring supports the support body 30.
The support board 300 is engaged with the rear surface side of the support body 300 through the hole 0121 of 0, and the two are engaged with each other in a sandwiched state. The top plate 1300 is pressure-bonded and fixed. The support 300 also has a hole 320 that allows the ink supply pipe 2200 that allows ink supply to pass therethrough. The wiring board 200 is attached to the support 300 by adhering it with an adhesive or the like. Further, the ink supply member 600 in which the parallel groove 3001 is formed is the ink conduit 16 that is continuous with the ink supply pipe 2200 described above.
00 is formed as a fixed cantilever on the side of the supply pipe 2200, and a sealing pin 602 for securing a capillary phenomenon between the fixed side of the ink conduit and the ink supply pipe 2200 is inserted. Since the ink supply member 600 is molded, the ink supply member 600 is inexpensive, has high positional accuracy, and prevents a decrease in accuracy in forming and manufacturing. In addition, the cantilevered conduit 1600 prevents the ink from the ink in the conduit 1600 described above even during mass production. The pressure contact state with respect to the receiving port 1500 can be stabilized.

In this embodiment, a complete communication state can be surely obtained by only pouring the sealing adhesive material from the ink supply member side under this pressure contact state. To fix the ink supply member 600 to the support 300, the back side pins (not shown) of the ink supply member 600 with respect to the holes 1901 and 1902 of the support 300 are attached to the holes 1901 and 1 of the support 300.
This can be easily performed by performing the through discharge through 902 and heat-sealing the portion protruding to the back surface side of the support 300.

The dot area is determined by the amount of ink ejected and the bleeding rate of the recording medium (this embodiment will be described below assuming that the bleeding rate of the recording medium is 1). Further, the ejection amount can be changed by the foaming volume of the ink, and the foaming volume increases as the number of ink molecules that undergo a phase transition due to heat increases. As a driving method for efficiently increasing the number of molecules, the limit energy that does not cause bubbling to the discharge heater is given to the ink on the heater surface (prepulse), and the time (interval time) for the heat to diffuse to other ink A method of increasing the number of ink molecules that cause a phase transition by increasing the number of ink molecules that easily cause a transition and then applying energy (main pulse) to the ink for subsequent ejection is adopted.
By changing the off-time, it is possible to increase or decrease the number of ink molecules that are likely to cause a phase transition and adjust the ink ejection amount.

Next, an example of a method for modulating the ink ejection amount used in the ink jet recording apparatus of this embodiment will be described below. In this embodiment, a divided pulse width modulation driving method for dividing a pulse width for driving a heater for heating ink is used, and pulses are given to the heater in the order of P1, P2 and P3 in order to print one dot. Here, P1 is a preheat pulse, P2 is an interval time, and P3 is a main heat pulse, which causes a bubble phenomenon of ink on the heater board 100 to eject an ink droplet from a nozzle hole. These pulse widths are the area of the heater board 100, the resistance value,
It depends on the film structure, the nozzle structure of the head, and the physical properties of the ink.

Therefore, when the head structure and the type of ink to be used are determined and the desired ejection amount: Vd (p1 / dot) is determined, the above-mentioned P1, P2 and P3 are arbitrarily determined (the same ejection amount is determined). The combination of P1, P2 and P3 that occurs is not limited to one). Next, a discharge amount control method using the interval time P2 will be briefly described. The relationship between the head temperature (TH) and the preheat pulse: P2 and the ejection amount: VD under the condition that P1 / P3 is 1 constant increases up to P2max as the pulse width of P2 increases as shown in FIG. However, after P2max, it is dominated by the heat conduction determined by the physical properties of the ink, etc. due to the change in the temperature distribution of the ink temperature in the vicinity of the heater (the main cause is the decrease in temperature).
However, it has been found that under these conditions, substantially the same ejection amount can be produced within about 10 ± 4 (μsec).

In the present embodiment, as the ejection characteristics of the head in which each color is independently driven and controlled by using the driving method as described above,
VOP = 28 in the environment of head temperature TH = 25.0 (° C)
(V), P1 = 2.00 (μsec), P2 = 9.
When a pulse of 0 ± 3 (μsec) and P3 = 5.00 (μsec) is given, optimum driving conditions are obtained and a stable ink ejection state is obtained. The ejection characteristics at this time are: ink ejection amount VD = 80.0 (ng / dot), ejection speed V = 1.
It was 6.0 (m / sec).

Although the above-described ink ejection amount control is performed in this embodiment, the pre-pulse, the applied voltage, or the combination of these may be used to control the ink ejection amount. next,
A control configuration for executing the recording control performed in this embodiment will be described with reference to the block diagram shown in FIG. In the figure showing the control circuit, 1700 is an interface for inputting a recording signal, 240 is a CPU, and 250 is a CP.
RO for storing control programs executed by U240
M and 1703 are dynamic ROMs for storing various data (recording data, recording data supplied to the head, etc.). The gate array 200 is the recording head 1
The print data is controlled to be supplied to the interface 1700, and the data transfer between the interface 1700, the CPU 240, and the RAM 1703 is also controlled. Reference numeral 1710 is a carrier motor for carrying the recording head 1, and 1709 is a carrying motor for carrying the recording medium. Reference numeral 1705 is a head driver for driving the head, and 1706 and 1707 are motor drivers for driving the carry motor 1709 and the carrier motor 1710, respectively. Incidentally, 1720 is a printer control unit.

The operation of the above control structure will be described. When a recording signal is input to the interface 1700, the recording signal is converted into recording data for printing between the gate array 200 and the CPU 240, and the motor driver 1706,
1707 is driven and the head driver 1705
The print head is driven according to the print data sent to the printer to print.

The recording head 1 used in this embodiment is an ink jet recording head having a resolution of 360 DPI and 128 nozzles. The 128 nozzles are allocated to one block every 16 nozzles, and the ejection control is performed for each same block. An outline of the logic configuration in the head chip of the recording head 1 is shown below in FIG.
Will be explained.

In FIG. 5, the heater board 100 is a chip of the recording head 1 on which the above logic is arranged.
A signal for recording, which is roughly classified into three, is input to the logic. The first is a print data signal, which is a signal for selecting the heater of the nozzle to be driven. This signal is input from the DATA signal line <1> in the figure and serially input to the shift register 101 in the recording head 1, and when data for 128 nozzles corresponding to all nozzles is stored, it becomes a latch signal (not shown). The data is latched in parallel in the latch 102 in synchronization. The latch 102 outputs an image signal to each AND gate 104 in which the number of nozzles is distributed.

The second signal is a block selection signal.
As described above, the recording head 1 has 8 blocks for every 16 nozzles, and therefore it is necessary to have a function of selecting 16 nozzles that are simultaneously driven and controlled in time series. In the figure
The signal lines 2>, <3>, and <4> have the above functions, and a 3-bit signal for selecting eight blocks is input to the decoder 103. The decoder 103 sends this signal to B
Decode to 8 signals from 1 to B8. Since the block division of the recording head 1 is divided every 16 nozzles from the top, the B1 signal corresponds to 1 from nozzle 1 to nozzle 16.
B2 signal is connected to 6 AND gates and nozzle 17
16 AND gates from the nozzle to the nozzle 32 are connected in the same manner.

The third signals are heat signals H1 to H16 which determine the driving time of the discharge heater. Heat signal H1
-H16 is a signal line described in <5> to <8> in the figure,
Sixteen nozzles, which corresponds to the number of nozzles in one block, are arranged (however, they are omitted to be four nozzles in the figure). This heat signal line is connected to every 16 lines from the upper part of the nozzle. That is, the first heat signal line H1 is connected to the AND gates of the nozzles 1, 17, 33, --- 113, and H2 is the nozzles 2, 18, 34, --- 114.
, ---, H16 are nozzles 16, 32, --- 128
Are connected to the AND gates.

That is, as also shown in FIG. 5, the discharge heater 105-1 of the nozzle 1 is turned on when the nozzle 105-
1 AND gate 104-1 connected to the data signal L1, the block selection signal B1, the sheet signal H1,
The above three signals are turned on. The method of modulating the recorded dot diameter is performed by modulating the pulse width of a signal for energizing the heater. That is, the pulse pattern of the heat pulse (single pulse, double pulse, etc.) or the heat signal line described with reference to FIG. 5 for controlling the pulse width, H
By regularly controlling the pulse signals from 1 to H16 for each heat dot, print control by a regular dot diameter is realized. Details of this control will be described below with reference to FIG.

In FIG. 6, reference numeral 240 denotes a CPU of the ink jet recording apparatus of this embodiment, which transfers data from an address designated by an address bus indicated by a solid line arrow in the figure through a data bus indicated by a broken line arrow in the figure. . As described above, the minimum recording cycle of this recording apparatus is 6 KHz,
28 nozzles are divided into 8 blocks every 16 nozzles for drive control. The drive interval of each block is 10 μs.
Is. During printing, the CPU transfers a trigger pulse every 6 KHz to the gate array 200. Upon receiving this trigger pulse, the gate array 200 turns on the block selection signal at block intervals of 10 μs and inputs it to the recording head 1.

At this time, a data signal (DATA) for selecting a nozzle to be driven is input to the shift register 101 of the recording head 1 from the data signal line in advance, and data is output from the shift register 101 in response to a latch pulse (not shown). Are latched by the latch circuit 102. The print data latched by the latch circuit 102 is input to each AND gate 104 connected to each discharge heater.

As a result, the block to be selected and the nozzles to be turned on (driven) in the selected block are determined, and in this state, the heat signal H1- is used to determine the heating condition.
By inputting H16 to the recording head 1, energy is applied to the ejection heater of each nozzle.
In this embodiment, in order to improve the image quality, the dot diameter of the ejected ink is regularly modulated, and in order to shorten the total control time for recording as much as possible, the heat that determines the energy applied to the ejection heater is used. The pattern is determined as follows. A method of determining the heat pattern will be described with reference to the flowchart of FIG.

First, when a trigger pulse is input to the gate array 200 every 6 KHz, the gate array 200 refers to the basic pulse at that time (step S11, step S12). The basic pulse may be a fixed value according to the recording head 1, but in this embodiment, the CPU 240 sets an optimal basic driving pulse according to the temperature of the recording head 1. The set location is the basic drive table No. in the register group 210 that can set various conditions provided in the gate array 200. The setting register 227. The ON / OFF pulse width is not directly set in the register 227, but various pulse patterns are preset in the PWM table 228.
The table number of is set. PWM table 2
In 28, 16 types of pulses from table numbers 1 to 16 are set. Specifically, the table 228
Stores a set value such that the ink ejection amount is increased or decreased by 1 ng if the table number is different by 1. Here, immediately after performing high-duty printing continuously, the temperature of the recording head 1 is raised, and therefore the ink ejection amount becomes large. In order to correct this, the basic pulse is set by the CPU 240 to a value that narrows down the ejection amount.

Next, how to set each heat signal H1-H16 will be described. Heat condition by each heat signal,
That is, the ejection amount of each nozzle is set to a drive pulse that varies evenly with respect to the ejection amount when driven by the basic pulse. As described above, the PWM table 228
Is set so that the discharge amount is modulated at equal intervals, the basic drive table No. With respect to the table number set in the setting register 227, the table number may be moved back and forth with an equal probability of occurrence and the pulse may be applied to each heat signal line. In order to evenly move the basic table number back and forth, a regular function centered on the initial value is generated, the value obtained by the regular function is added to the basic table number, and the heat signal H to each heat signal line is added.
It can be realized by creating 1-H16.

However, since the recording head 1 has 128 nozzles and is driven at 6 KHz, it generates a function value at least 128 times (a value obtained by a certain function) within 166 μs, The PWM value setting must be repeated 128 times. Normal CPU2
Reference numeral 40 denotes a function for controlling the engine including heat interrupt processing and motor drive interrupt processing during printing,
The CPU 240 processes both the function as a controller that analyzes the print command and expands the print data by time division. With the recent increase in speed of recording devices, CP
The throughput of U240 per unit time is increasing dramatically. If these processes overflow during printing in which the processes are most concentrated on the CPU 240, the engine function cannot be neglected because the recording device is operating. Therefore, the division processing is controlled so that the controller function is stopped at 1 o'clock and the recording apparatus does not malfunction. However, stopping the controller function is to temporarily stop the expansion of the print data of the next line, and after printing, the operation of the recording device waits until the expansion of the print data of the next line is completed. 1
Even if the line-by-line print speed is extremely high, the print time per page does not become so high.

It is obvious that the recording apparatus will be further increased in speed in the future. How to perform the basic function of the recording apparatus at high speed and how to reduce the CPU 240 occupancy in the additional processing will be described. It can be said to be one of the most important issues in responding to future speed increases. Regular dot control that modulates the dot diameter for each print dot is effective from the above development of the printing apparatus, and although it is effective in improving the image quality, it is often difficult to install processing. However, in the present embodiment, the processing is reduced as described below.

In this embodiment, the function value for regularly modulating the dot diameter is calculated in advance and held in the RAM 230 in the form of a table. And if necessary, the RAM 23
The function value is drawn from 0 to the gate array 200 (step S13). Normally, it is necessary to further process the function value to generate a pulse, but in the present embodiment, the PWM table 228 is provided in the gate array 200 as described above, and the PWM table 228 has the same ejection for each table number. Since it is set to be the amount modulation width,
The regular dot diameter control can be performed by adding the function value extracted from the function table 231 to the basic drive table number preset by the CPU 240 at the optimum timing (step S14). Then, by the table NO obtained in step S14, PW
The pulse generation information of the M table 228 is acquired to generate the heat pulse (step S15).

Here, in this embodiment, the function table 231
Is a numerical table that is regularized between ± 3 with 0 at the center. That is, the dot diameter is regularly modulated with a modulation width of ± 3 ng, with the basic drive pulse that provides the desired discharge amount in the state of the print head 1 in consideration of the current temperature rise and the like as the central discharge amount. Is done. Further, since the configuration of the recording head 1 is 16 nozzles per block as described above, it is necessary to read 16 function values for printing one block. The width of the function in this embodiment is ± 3 as described above and 7 in the range, and one function value is stored in 3 bits. That is, a value of 3 word length is extracted for each block print, but since the CPU 240 used in this embodiment is a 16-bit CPU, it can be accessed three times. Further, the gate array 200 is a CP
While the U240 is accessing the ROM250, the gate array 200 itself generates a desired address and the RAM2
The function of accessing 30 is added, and in effect the CPU2 required to draw the function onto the gate array 200.
The occupancy of 40 is configured to be zero. Further, after the desired function value is input to the gate array 200, the pulse to be placed on the heat signal line can be calculated and selected only by the addition process which is easy to process as described above, and the desired regular dot can be obtained with extremely few processes. Diameter modulation control becomes possible.

In this embodiment, the function table stored in the ROM 240 is expanded in the RAM 230 for control, but the ROM may be accessed directly. As described above, a function table for preliminarily calculating a function and holding it in the form of a table, a PWM table for preliminarily holding the driving pulse pattern in the form of a table, and an equal ejection amount by the pulse pattern set in the PWM table By including a discharge amount modulation unit that discharges ink with a modulation width and a DMA that allows a gate array to generate a desired address and access data at a desired address without going through a CPU, white streaks, black streaks, etc. of a recorded image It is possible to realize the control in which the increase in the processing capacity, that is, the adverse effect of the rule control, that is, the increase in the CPU load is reduced, while making the density unevenness of (3) inconspicuous.

Next, an example of the method of generating the regular pattern used in this embodiment will be shown. 7 to 10 show examples of rule patterns. In the present embodiment, the triangular function is used to form the periodic function. At this time, the cycle of the function; T, the width (amplitude) of the modulation; Aij, the phase; φij, etc. are determined so as to reduce the density unevenness of the initial recording head, and the cycle is preferably as short as possible, and at least 1/2 the number of nozzles
The following (however, depending on the resolution of the nozzle) is required, and if it is more than this, even if a regular pattern is formed, it is not preferable because the human eyes are concerned about the unevenness. In order to exert an effect on any density unevenness, it is preferable that the number of nozzles of the head; the number of nozzle groups in a block (the number of blocks; Mb) in which N is divided and driven simultaneously (N / Mb).
The number of nozzles driven at the same time). This is because the density unevenness generated in the nozzles is closely related to the driving method (sequential, forward division, dispersion, etc.) in addition to the individual variations of the nozzles, particularly when a fluid of the inkjet recording method is used. The amplitude is preferably as large as possible, and it is desirable that the central ejection amount is modulated by about ± 10% or more. This is because if the modulation width is less than ± 10%, the regular pattern cannot be seen as the density perceived by human eyes. The phase may be arbitrarily determined when forming the regular pattern.

In this embodiment, the following functions are used to generate the regular pattern. f (θij) = Aij · sin (Bij · θij + φij) Aij; Amplitude Bij; Coefficient θij; Period φij; Phase Fig. 7- shows that various coefficients are changed using the above function.
This corresponds to FIG. In the present embodiment, the triangular function is used, but other functions may be used, or a pattern having regularity may be created by using a plurality of functions, and the function should be such that adjacent nozzles have different regularity as much as possible. It suffices to determine the changing conditions of. However, the higher the regularity period of the regular pattern generated here is, the more preferable it is. However, the regular pattern cannot be generally determined because it is determined by the relation with the original unevenness of the recording head 1. Therefore, the user or the like may be allowed to arbitrarily select the regularity.

11 and 12 show a state in which printing is performed by using the periodic pattern using various functions as described above. Further, an enlarged view of the state of density unevenness at each gradation (4 patterns) by the Bayer type dither type by each method (8
× 8) is shown in FIGS. 13 to 17. Here, the state of density unevenness in each gradation data is represented, and it can be seen that the state of density unevenness changes according to the gradation data. Therefore, it is possible to further reduce the density unevenness by changing the cycle of the regular pattern according to the gradation data. When changing the rule pattern according to the gradation data, it is desirable to increase the cycle as the gradation becomes lower (low density). This is the same as printing one type of thinning pattern because the dot hitting cycle is long at low gradations, so interference occurs with this thinning pattern and a new cycle occurs. This, on the contrary, causes noise.

As described above, by forming the regular pattern so that the image does not deteriorate, it is possible to reduce the density unevenness or the like originally possessed by the recording head, and to obtain a high quality image in one pass. Can be printed. (Embodiment 2) Next, another embodiment for further improving the image quality in the rule control will be described. FIG.
The color ink jet recording apparatus adopting the driving method of this embodiment is shown in FIG. This device is a full-color serial type printer having replaceable recording heads corresponding to four color inks of black (Bk), cyan (C), magenta (M), and yellow (Y). The head used in this printer has a resolution of 400 dpi and a drive frequency of 6.0 (KH
z), it has 128 discharge ports. In FIG. 18, C is a four-in-one recording head cartridge corresponding to each ink of Bk, C, M, and Y, and the recording head and an ink tank that stores ink for supplying the ink are integrally formed. Has been done. The recording head cartridge C is detachably attached to the carriage by a configuration (not shown). The carriage 2 is slidably engaged along the guide shaft 11 and is connected to a part of a drive belt 52 that is moved by a main scanning motor (not shown). This allows
The recording head cartridge C can be moved along the guide shaft 11 for operation. 15, 16 and
Reference numerals 17 and 18 denote conveying rollers that extend substantially parallel to the guide shaft 11 on the back side and the front side in the drawing of the recording area by the operation of the recording head cartridge C. Transport roller 15,
16 and 17, 18 are driven by a sub-scanning motor (not shown) to convey the recording medium P. The conveyed recording medium P faces the surface of the recording head cartridge C on which the ejection port surface is provided, and constitutes a recording surface.

A recovery section unit is provided facing the movable area of the cartridge C adjacent to the recording area of the recording head cartridge C. In the recovery section,
Reference numeral 300 denotes a cap unit provided corresponding to each of the plurality of cartridges C having a recording head. The cap unit 300 can slide in the left-right direction in the drawing as the carriage 2 moves, and can move up and down in the vertical direction. And carriage 2
When the is at the home position, it is joined to the recording head to cap it. Further, in the recovery unit, 401 and 402 are first and second blades as wiping members, respectively, and 403 is the first blade 40.
Reference numeral 1 is a blade cleaner which is an absorber for cleaning.

Further, reference numeral 500 denotes a pump unit for absorbing ink or the like from the ejection port of the recording head and its vicinity via the cap unit 300. FIG. 19 is a block diagram showing a configuration example of a control system in the color inkjet recording apparatus. Reference numeral 800 denotes a controller forming a main control unit, which includes, for example, a CPU 801 in the form of a microcomputer that executes various sequences, a ROM 803 that stores corresponding programs and tables, other setting values, and a supply source of image data. A correction device (which may be a reader unit for image reading),
Commands, status signals, etc. for image data are transmitted / received to / from the controller via an interface (I / F) 812 (print pattern development is performed in this portion and ejection amount correction data for each nozzle is created). . Reference numeral 820 denotes a switch group that receives a command input by an operator, such as a power switch 822, a switch 824 for instructing recording start, and a recovery switch 826 for instructing recovery start. Reference numeral 830 denotes a sensor 832 for detecting the position of the carriage 2 such as a home position sensor and a start position, and a sensor 834 including the leaf switch 530 and used for detecting the pump position.
It is a sensor group for detecting the state of the device.

Reference numeral 840 is a head driver for driving the electrothermal converter of the recording head according to recording data and the like. Further, a part of the head driver includes heaters 30A and 30A.
It is also used to drive B. Furthermore, the temperature sensor 2
After the temperature detection values from 0A and 20B are input to the controller 800 and converted into temperature data in the RAM 805,
The calculation for creating a regular pattern in combination with the ROM 803 storing the modulation data by the periodic function is performed by the CPU 80.
The discharge amount information is converted into a drive signal by the ROM 804 storing the discharge amount control information and sent to the head driver 840. 850 is a main scanning motor for moving the carriage 2 in the main scanning direction, and 852 is its driver. A sub-scanning motor 860 is used to convey the recording medium.

In the above embodiment, one function table is used as the dot diameter modulating means, but it is also possible to use a plurality of function tables. FIG. 20 is a configuration diagram of the control unit of the ink jet recording apparatus of this embodiment. FIG.
In the figure, reference numeral 240 denotes a CPU of the recording apparatus, which transfers data from an address designated by an address bus indicated by a solid arrow in the figure through a data bus indicated by a dashed arrow in the figure. Similar to the above embodiment, the nozzles to be driven are selected by three kinds of signal lines, the print data is selected from the data signal line, the block is selected by the block selection signal line, and the heating condition is set by the heat signal line. Is. Further, in order to regularly modulate the dot diameter of the ink to be ejected in order to improve the image quality and to shorten the total control time for the regularization as much as possible, a function calculated in advance as in the first embodiment is used. A means for tabulating the values, a PWM table for holding the drive pulse patterns in the form of a table in advance, and an equal ejection amount modulation in which the pulse patterns set in the PWM table have equal ejection amount modulation widths. Means, and a DMA that allows the gate array to create the desired address and access the data at the desired address without going through the CPU.

As described above, the processing time can be greatly shortened by calculating in advance and forming a table as compared with the case where the function is calculated every time, but the periodicity of the calculation table appears in the image and causes unevenness. There were cases where it appeared. This problem can be solved by making the memory for storing the already-calculated table sufficiently large, but it is often difficult to incorporate the above measures due to the cost. (For example, resolution 4
In order to have a function of 5 lines with 1 bit of 3 bits in a recording device of 00 DPI, a memory capacity of about 3.2 Mbits is required. ) This embodiment solves the above problem, and eliminates the above regularity by randomly selecting and using a plurality of function tables. Specifically, a 200K-bit function table (resolution 400DP
I, 1 information 3-bit recording device has five sheets (corresponding to a function value of about 4/10 lines), and the five function tables are regularly selected and used.

By performing the control as described above, the periodicity of the function table can be considerably eliminated. As a result, even if the above rule control is executed by a function table with a small control load, it is possible to suppress the occurrence of periodic unevenness in the recorded image,
It is possible to realize a recording apparatus that suppresses the adverse effects of high quality output images, processing speed, and a large increase in memory capacity.
The function table rule selecting means may be a means for causing the CPU or the gate array to perform calculation at the timing when the function table is changed (the current function table ends). In this case as well, with the setting according to the present embodiment, since the calculation is performed once every hundred and several tens of ms, a large processing load does not occur. Further, a function table selection table for regularly selecting the function table may be separately provided, and means for obtaining information of a function table to be selected next from the function table selection table at a desired timing may be used.

As described above, by having a plurality of function tables having a plurality of function tables and a function table selecting means for regularly selecting the plurality of function tables, white stripes, black stripes, etc. of recorded images can be eliminated. It is possible to realize a recording apparatus that suppresses an increase in processing time and an increase in required memory capacity, which are adverse effects of printability, while following the effect of making density unevenness inconspicuous.

Next, the discharge amount control method (including the modulation method) in this embodiment will be described. In order to control the ejection amount, it is necessary to give a characteristic to the drive waveform of the head, and the head drive uses a divided pulse (multi-pulse) drive method.
As a typical pulse waveform, a double pulse waveform is used as shown in FIG. 21, where Vop is a driving voltage, P1 is a preheat pulse width, P2 is an interval time (off time), and P3 is a main heat pulse width. There is. T
1 * T2 * T3 has shown the time for determining P1 * P2 * P3. VOP is the electrical energy required to generate thermal energy on H · B, and is determined by the area of H · B, the resistance value, the film structure, and the nozzle structure of the head.

The divided pulse width modulation driving method used in this embodiment gives pulses in the order of P1, P2 and P3, where P1 is the output value from the diode temperature sensor and the head base temperature; TH (K. C / M / Y), the pulse width before printing and during printing is determined by using the one corrected based on all the information from the table by the periodic function, and the PWM
We are in control. The role of each pulse is that P1 is a preheat pulse, which is a pulse width mainly for controlling the ink temperature distribution in the nozzle, and is used to directly change the ejection amount,
The pulse width of P1 is controlled according to the temperature of the head. At this time, excessive heat energy is applied to H and B so that the pre-foaming phenomenon does not occur. P2 is an interval time and has a function of controlling the temperature distribution of the ink in the nozzle by providing an interval of one constant time so that the pre-heat pulse P1 and the main heat pulse P2 do not interfere with each other (this interval can also control the ejection amount). is there). P3 is a main heat pulse that causes a bubbling phenomenon on H and B to eject ink droplets from the nozzle holes. These pulse widths are H ・ B
Area, resistance value, film structure, nozzle structure of head, and ink properties.

Therefore, when the head structure and ink are determined, and the desired ejection amount: Vd (p1 / dot) is determined, P1,
P2 and P3 are arbitrarily determined (the combination of P1, P2 and P3 that generate the same ejection amount is not limited to one). However, in consideration of the temperature dependence of the discharge amount, which will be described later, it is preferable that the interval time P2 be somewhat longer (for example, 2 μs <P2 <15 μs is preferable) in order to widen the control range of the discharge amount with respect to the temperature change.

Next, the discharge amount control method using the preheat pulse P1 (which can be controlled in the same manner in P2) will be briefly described. The relationship between the preheat pulse: P1 and the ejection amount: VD under a constant head temperature (TH) condition is linear (or non-linear) up to P1LMT as the pulse width of P1 increases as shown in FIG. After that, the pre-foaming phenomenon disturbs the foaming of the main heat pulse P3, so that the ejection amount tends to decrease after P1MAX.

Preheat pulse: P1 The relationship between the head temperature: TH (environmental temperature) and the ejection amount: VD under a constant condition has a tendency to increase linearly as the head temperature TH increases, as shown in FIG. Show. The coefficients of the respective regions showing the linearity are: Preheat pulse dependence coefficient of discharge amount: KP1 = ΔVDP / ΔP1 (ng / μs · dot) Interval time dependence coefficient of discharge amount: KP2 = ΔVDP / ΔP2 (ng / μs · dot) ) Head temperature dependence coefficient of ejection amount: KTH = ΔVDP / ΔTH (ng / C · dot)

In the head structure shown in FIG. 24, the above coefficient is KPBk = 8.25 (ng / μsec · dot) KTHBk = 0.7 (ng / μsec · dot), and the relationship between these two will be described below. As shown in FIG. 25, when P1 (or P2) is pulse width modulated under PWM control according to head temperature / modulation data (correction by a function table), it is possible to use the ambient temperature / printing. Even if the head temperature changes due to self-heating, a pattern can be regularly generated while keeping the ejection amount constant. In this way, an ejection characteristic control method (ejection amount modulation) that makes a regular pattern while always maintaining the ink ejection amount of each color as a target is enabled.

In this embodiment, as the ejection characteristics of the head in which each color is independently driven and controlled by using the above-described driving method, VOP = 2 in the environment of the head temperature TH = 25.0 (° C.).
When V (8), P1 = 2.00 (μsec), P2 =
9.0 ± 3 (μsec), P3 = 4.00 (μsec)
When the pulse is given, optimum driving conditions are set and a stable ink ejection state is obtained. The ejection characteristics at this time are as follows: ink ejection amount VD = 40.0 (ng / dot) ejection speed V = 1
It was 4.0 (m / sec).

(Embodiment 3) Next, another embodiment for controlling the modulation width to be regularized in the regulation control will be described. In the embodiment, the regularized modulation width of the dot diameter is fixed by the recording apparatus, but as described above, the control may cause unevenness in the image or roughness in the image. Further, as described above, the unevenness in the period and the feeling of roughness have the property of increasing in proportion to the modulation width of the dot diameter and the period. On the contrary, the feeling of [white streak] and [black streak] in the image is the modulation width. It is accompanied by a reduction in inverse proportion to. Therefore,
The modulation width of the dot diameter is set to the maximum modulation width of the periodic unevenness or roughness that is not usually noticeable, but the periodic unevenness or roughness is largely due to the user's orientation, and some may be Some users don't become irrelevant, while others sensitively hate depend rarely.

The present embodiment is aimed at eliminating the above-mentioned difference in user's orientation, and a plurality of function tables each have different variation levels, and depending on the selected function table. The table is configured so that the modulation width of the dot diameter is restricted. Specifically, this embodiment has five types of function tables, and the respective function variation ranges are ± 1, ± 2, ± 3, ± 4, ± 5,
Is configured to be. That is, the values of 0, 1, and 2 are periodically arranged in the function table of ± 1, and the PWM table number selected by the center value 1 is stored in the basic drive table number setting register. There is P
The drive signal is applied with the WM table number unchanged. 0
Then, the basic drive table number is decremented by 1, and the drive is performed under the condition of the PWM table which is one unit less. On the contrary, in the function 2, the basic drive table number is incremented by 1, and the drive is performed under the condition of the PWM table which is larger by one unit.

By configuring so that the optimum table can be selected from the function tables configured as described above, it is possible to control the optimum variation range depending on the user's preference and the type of output image to a desired range. Become.
As a method of setting the desired function variation range, it may be transmitted to the recording device by means of a command, means by a switch such as a panel switch or dip switch, or a combination of these means. Since a means for transmitting information to the recording device is a very basic technique known in the art, a detailed description thereof will be omitted here.

Further, the configuration and control other than the desired function table selection control means are the same as those in the above-mentioned embodiment, and detailed description thereof will be omitted. In addition, the number of passes for multi-pass printing can be changed in a printing device that can change the printing state from one pass depending on the print mode (fast, normal, high image quality, etc.) such as multi-pass printing and the printing medium. Alternatively, the regularity may be corrected by taking into consideration the mask pattern applied at that time and multiplying it by the actual print pattern (thinning pattern).

The head driving method can be applied to various known methods, such as sequential, forward, distributed driving method, etc.
The optimum driving method for the head is selected from parameters such as the block division number and the driving frequency. At this time, the regularity may be corrected in consideration of the driving order and the influence of the simultaneous ejection nozzles. Further, the regularity may be changed depending on the position of the nozzle (where the block is driven, etc.).

The present invention also has another plurality of nozzles,
The same can be applied to a recording head in which variations in nozzles occur. As an example, even in a piezo type ink jet recording apparatus, the same effect can be obtained by applying the present invention to the modulating means. The present invention may be applied to a system including a plurality of devices or an apparatus including one device. Further, it goes without saying that the present invention can be applied to the case where it is achieved by supplying a program to a system or an apparatus. The present invention is provided with a means (for example, an electrothermal converter or a laser beam) that generates thermal energy as energy used for ejecting ink, particularly in the inkjet recording system, and the state of the ink is determined by the thermal energy. I explained about the printing device of the type that causes change,
According to this method, high density recording and high definition recording can be achieved.

With regard to its typical structure and principle, see, for example, US Pat. Nos. 4,723,129 and 4740.
What is done using the basic principles disclosed in 796 is preferred. This method can be applied to both the so-called on-demand type and continuous type, but especially in the case of the on-demand type, liquid (ink)
By applying at least one drive signal to the electrothermal converter arranged corresponding to the sheet or liquid path in which the liquid crystal is held, which corresponds to the recorded information and causes a rapid temperature rise exceeding film boiling. Since the electrothermal converter is caused to generate heat energy to cause film boiling on the heat-acting surface of the recording head, as a result, bubbles in the liquid (ink) corresponding to the drive signal in a one-to-one relationship can be formed. It is valid. The liquid (ink) is ejected through the ejection openings by the growth and contraction of the bubbles to form at least one droplet. It is more preferable to make this drive signal in a pulse shape, because bubbles can be grown and contracted immediately and appropriately, and thus a liquid (ink) with excellent responsiveness can be achieved.

As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. If the conditions described in US Pat. No. 4,313,124 of the invention relating to the rate of temperature rise on the heat acting surface are adopted, more excellent recording can be performed. As the structure of the recording head, in addition to the combination structure (straight liquid flow path or right-angled liquid flow path) of the ejection port, the liquid path, and the electrothermal converter as disclosed in the above-mentioned specifications, a heat acting surface is also provided. A configuration using US Pat. No. 4,558,333 and U.S. Pat. No. 4,459,600, which disclose a configuration in which is arranged in a bending region, is also included in the present invention. In addition, Japanese Unexamined Patent Application Publication No. Sho 5-5 discloses a configuration in which a common slot for a plurality of electrothermal converters is used as a discharge portion of the electrothermal converters.
Japanese Patent Application Laid-Open No. 9-123670 and Japanese Patent Application Laid-Open No. Sho 5 (1993) -58
The configuration may be based on Japanese Patent Publication No. 9-138461.

Further, as a full line type recording head having a length corresponding to the maximum recording medium width that can be recorded by the recording apparatus, the length can be increased by combining a plurality of recording heads as disclosed in the above-mentioned specification. Either of the structure satisfying the requirement or the structure as one recording head integrally formed may be used. In addition, the ink is integrated into the replaceable chip-type recording head, or the recording head itself, which can be electrically connected to the apparatus main body and can supply ink from the apparatus main body by being attached to the apparatus main body. A cartridge-type recording head provided with a tank may be used.

Further, it is preferable to add a recovery means for the recording head, a preliminary auxiliary means, etc., which are provided as a constitution of the recording apparatus of the present invention, because the effect of the present invention can be stabilized in one layer. is there. Specific examples thereof include capping means, cleaning means, pressurizing or suctioning means for the recording head, preheating means using an electrothermal converter or another heating element or a combination thereof, and recording. It is also effective to perform a stable recording by performing a preliminary discharge mode in which another discharge is performed.

Further, the recording mode of the recording apparatus is not limited to the recording mode of only the mainstream color such as black, but the recording head may be integrally formed or a plurality of combinations may be used. Alternatively, the device may be provided with at least one of full-color mixed colors. In the embodiments of the present invention described above, the ink is described as a liquid, but an ink that solidifies at room temperature or lower, or one that softens or liquefies at room temperature may be used, or an ink jet system may be used. Generally, the temperature of the ink itself is adjusted within the range of 30 ° C to 70 ° C to control the temperature of the ink so that the viscosity of the ink is within the stable ejection range. Anything can be used.

In addition, in order to positively prevent the temperature rise due to thermal energy from being used as the energy for changing the state of the ink from the solid state to the liquid state,
Alternatively, in order to prevent the ink from evaporating, an ink that solidifies in a standing state and liquefies by heating may be used. In any case, by applying heat energy, such as ink that is liquefied by applying heat energy according to the recording signal and liquid ink is ejected, or that begins to solidify when it reaches the recording medium. The present invention can be applied to the case where an ink having a property of being liquefied for the first time is used. In such a case, the ink is retained as a liquid or solid in the recesses or through holes of the porous sheet as described in JP-A-54-56847 or JP-A-60-71260. It may be configured to face the electrothermal converter. 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 provided integrally or separately as an image output terminal of an information processing device such as a computer, a copying apparatus combined with a reader or the like, and further transmission / reception. It may take the form of a facsimile machine having a function.

[0074]

[Effects of Embodiments] Not only it is possible to reduce the density unevenness that varies with the initial stage of nozzles, during printing, and with time, by creating the above-mentioned regular pattern that is not perceived by human eyes as noise. The density unevenness such as white streaks and black streaks in a recorded image during 1-pass printing can be made inconspicuous. Further, it is possible to take measures against an increase in data processing capacity, which is an adverse effect of control, to enable high-speed printing, and to control the rough feeling on the image while changing it to a desired range.

[0075]

As described above, according to the present invention, it is possible to reduce the load on the CPU when executing the regular dot control. Furthermore, according to another configuration, while reducing the load applied to the CPU in executing the regular dot control, the rough feeling caused by the regular dot control is reduced while being changed to a desired range, and high resolution printing is achieved. Can be achieved.

[Brief description of drawings]

FIG. 1 is a perspective view of a thermal inkjet recording apparatus according to a first embodiment.

FIG. 2 is a perspective view of the thermal inkjet recording head according to the first embodiment.

FIG. 3 is a diagram showing a relationship between an interval time; P2 and an ink ejection amount; Vd in the recording head used in the first embodiment.

FIG. 4 is a block diagram illustrating a block configuration for performing recording control of the recording apparatus according to the first embodiment.

FIG. 5 is a block diagram illustrating the logic configuration of the recording head according to the first embodiment.

FIG. 6 is a block diagram illustrating drive control means of the recording head according to the first embodiment.

FIG. 7 is a diagram showing a generated rule pattern 1.

FIG. 8 is a diagram showing a generated rule pattern 2.

FIG. 9 is a diagram showing a generated rule pattern 3.

FIG. 10 is a diagram showing a generated rule pattern 4.

FIG. 11 is a diagram showing a printed state 1 of printing.

FIG. 12 is a diagram showing a printed state 2 of printing.

FIG. 13 is a diagram showing the density unevenness of initials by an 8 × 8 Bayer systematic dither method.

FIG. 14 is a diagram showing density unevenness by a conventional method by an 8 × 8 Bayer systematic dither method.

FIG. 15 is a diagram showing density unevenness due to the regular pattern of the present invention by an 8 × 8 Bayer systematic dither method.

FIG. 16 is a diagram showing density unevenness due to the high periodic regular pattern of the present invention by an 8 × 8 Bayer systematic dither method.

FIG. 17 shows uneven density of 8 according to the regular pattern 1 of the invention.
The figure represented with the Bayer systematic dither method of x8.

FIG. 18 is a perspective view of a color inkjet recording apparatus.

FIG. 19 is a block diagram for control of the second embodiment.

FIG. 20 is a block diagram of a control structure for dot modulation according to a second embodiment.

FIG. 21 is a diagram of a divided pulse waveform.

FIG. 22 is a diagram showing a relationship between a preheat pulse; P1 and a discharge amount; Vd.

FIG. 23 is a diagram showing the relationship between head temperature; T and ejection amount; Vd.

FIG. 24 is a diagram showing a configuration of a head used in the second embodiment.

FIG. 25 is a diagram showing the configuration of a head used in the second embodiment.

FIG. 26 is an explanatory diagram of PWM control.

FIG. 27 is a flowchart showing a method for determining a heat pattern.

[Explanation of symbols]

 200 gate array 210 register group 228 PWM table 230 RAM 231 random number table 240 CPU 250 ROM

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location B41M 5/00 A B41J 3/12 G

Claims (33)

[Claims] 1. A recording apparatus for forming a recorded image using a recording head having a plurality of recording elements for forming dots on a recording medium, comprising: first storage means for storing information designating a dot diameter to be recorded. A second storage means for storing control information for generating a plurality of dot diameters; and a control means for acquiring control information from the second storage means on the basis of information sequentially read from the first storage means to form dots on a recording medium. And a forming unit for forming a recording medium. 2. The recording apparatus according to claim 1, wherein the recording head is an inkjet recording head that performs recording by ejecting ink. 3. The recording head is a recording head which ejects ink by utilizing thermal energy, and is provided with a thermal energy converter for generating thermal energy applied to the ink. Item 2. The recording device according to item 2. 4. The recording apparatus according to claim 1, wherein the information designating the dot diameter to be recorded is generated based on a periodic function. 5. The recording apparatus according to claim 1, wherein the forming unit forms dots by periodically modulating the dot diameter. 6. The recording apparatus according to claim 5, wherein the forming unit divides a plurality of recording elements into a plurality of blocks and periodically modulates a dot diameter for each block to form dots. 7. The recording apparatus according to claim 5, wherein the period of the periodic function changes centering on a period of about 1/2 or less of the width corresponding to all recording elements. 8. The recording apparatus according to claim 6, wherein the period of the periodic function changes centering on a period of about twice the width of one of the blocks. 9. The recording apparatus according to claim 4, wherein the periodic function is a triangular function capable of changing its amplitude, period, and phase. 10. The recording apparatus according to claim 5, wherein the modulation of the dot diameter is performed by applying a plurality of pulses to the recording head. 11. The recording apparatus according to claim 4, wherein the period changes according to the gradation of recording data. 12. A recording apparatus for forming a recorded image using a recording head having a plurality of recording elements for forming dots on a recording medium, comprising means for reading the temperature of a nozzle and information for designating a dot diameter to be recorded. A first storage means for storing a plurality of dot diameters, a second storage means for storing control information for generating a plurality of dot diameters, a third storage means for storing information for correcting dots based on the temperature of the nozzle, 1. A recording apparatus comprising: a forming unit that obtains control information from the second storing unit by the information sequentially read from the first and third storing units and forms dots on the recording medium. 13. The recording apparatus according to claim 12, wherein the recording head is an inkjet recording head that performs recording by ejecting ink. 14. The recording head is a recording head which ejects ink by utilizing thermal energy, and is provided with a thermal energy converter for generating thermal energy applied to the ink. Item 13. The recording device according to item 13. 15. The recording apparatus according to claim 12, wherein the information designating the dot diameter to be recorded is generated by a periodic function. 16. The recording apparatus according to claim 12, wherein the dot diameter is periodically modulated and formed on a recording medium. 17. The recording apparatus according to claim 16, wherein the dot diameter is cyclically modulated and formed for each block on the recording medium. 18. The recording apparatus according to claim 17, wherein a plurality of dot diameters are generated for each block. 19. The recording apparatus according to claim 15, wherein the period of the periodic function changes centering on a period of about 1/2 or less of the width corresponding to all recording elements. 20. The recording apparatus according to claim 19, wherein the period of the periodic function changes centering on a period of about twice the width of one of the blocks. 21. The recording apparatus according to claim 20, wherein the periodic function is a triangular function capable of changing its amplitude, period, and phase. 22. The recording apparatus according to claim 17, wherein the dot diameter is modulated by a plurality of pulses. 23. The recording apparatus according to claim 21, wherein the period changes according to gradation data. 24. In a recording method for forming a recorded image by using a recording head having a plurality of nozzles for forming dots on a recording medium, a trigger pulse is input to a gate array, and in the gate array, a basic drive pulse at that time is supplied. Refer to, the heating condition for the heating signal line is set so that the ejection amount of each nozzle periodically changes with respect to the standard ejection amount of ink when driven by the basic drive pulse, and the driving is performed with the set heating condition. A recording method characterized in that a pulse is transmitted. 25. The recording method according to claim 24, wherein the basic pulse is fixed by a head. 26. The recording method according to claim 25, wherein the basic pulse is optimally set by the CPU according to the temperature of the recording head. 27. The recording method according to claim 26, wherein the setting of the basic pulse is performed by a basic table number of a setting register formed in a gate array. 28. The recording method according to claim 27, wherein various pulse patterns are preset in the basic table number. 29. The recording method according to claim 28, wherein each type of pulse of the basic table number is set so that the smaller the basic table number is, the more the ink ejection amount is reduced. 30. The recording method according to claim 29, wherein the ejection amount of each nozzle is set so as to change periodically (regularly) with respect to the drive by the basic pulse. 31. The periodic variation is set by adding a value created by a regular function centered on an initial value and the table number. Recording method. 32. The recording method according to claim 31, wherein the regular function is given by a triangular function. 33. The recording method according to claim 24, wherein the head is driven by multiple pulse driving.