JPH0852885A - Ink jet recording apparatus and preparatory emitting method - Google Patents

Abstract

PURPOSE:To provide an ink jet recording apparatus capable of freely selecting a preparatory emitting pattern, capable of easily adding and altering the preparatory emitting pattern and capable of efficiently performing the preparatory driving of a head on the basis of the optimum preparatory emitting pattern corresponding to a head state. CONSTITUTION:An ink jet recording apparatus is constituted by mounting an ink jet head having a plurality of nozzles arranged thereto in one row on a carriage relatively moving with respect to a recording medium and performs the printing recording of one line in a nozzle arranging direction by emitting ink from a nozzle group. A first memory means 31 storing a plurality of preparatory emitting data preparatorily driving the head and a second memory means 38 storing the specific preparatory emitting pattern data selected from a plurality of the preparatory emitting data are provided to this ink jet recording apparatus.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus, and more particularly, to an ink jet recording apparatus for ejecting an ink liquid from a recording head onto a recording medium to perform ink pre-ejection. Recording device Furthermore, the present invention relates to a multi-nozzle inkjet recording apparatus for carrying out print recording by mounting an inkjet head having a plurality of nozzles on a carriage that moves relatively to a recording medium, and a head preliminary ejection method for the same.

[0002]

2. Description of the Related Art In an ink jet recording apparatus, a cap mechanism for covering a head nozzle portion is provided to shield the head nozzle portion from the outside air in order to prevent the ink existing in the nozzle portion from drying during non-printing. However, even if such a cap mechanism is provided, it is very difficult to keep the airtightness in the cap constant for a long period of time. The ink gradually evaporates into the outside air, and the physical properties of the ink, in particular its viscosity, become high, and it becomes difficult to eject the ink.

When a normal printing operation is performed in such a state, under normal nozzle driving conditions, the ink having a high viscosity near the nozzle ejection port is not ejected, or even if ejected, the directionality thereof is unstable. As a result, there is a problem that defective printing and defective image quality occur. For the purpose of solving such a problem of printing failure, a method has been proposed in which the head is preliminarily driven before the printing / recording operation so that the ink is easily ejected before the printing operation. That is, in order to preliminarily drive the print head of the inkjet printing apparatus, the print pulse state and the drive pulse width of the head are set by being converted into the clock cycle in order to quickly and easily optimize the printing state. A method of predriving a head by setting the number of drive pulses is described in Japanese Patent Laid-Open No. 62-179945. This proposes a hardware configuration that provides a control circuit for pre-driving, reduces the load of software, and enables pre-driving at high speed.

Further, when it is judged that there is ink with high viscosity in the nozzle or the head temperature is lower than a predetermined temperature,
A method of detecting the temperature of the recording head and feeding it back to the printer control unit to maintain the temperature of the recording head at a substantially predetermined value is disclosed in Japanese Patent Laid-Open No. 64-38246.
This method uses the detected temperature of the recording head, the color of the ink in the head, and information about the usage profile of the recording head to induce ejection of ink droplets so as to maintain the uniformity of ejected ink droplets. A pulse below the threshold is applied to heat the recording head, or some of the ink droplets are ejected from the nozzle. That is, the nozzles are driven to such an extent that ink is not ejected, or preliminary drive for ejecting ink is performed, and these judgments and operations are always performed prior to the subsequent printing operation to avoid defective printing. There is.

Also, in order to shorten the waiting time until the temperature of the recording head reaches a recordable temperature after the power is turned on, a method of applying an electric signal having a frequency higher than the recording frequency is disclosed in Japanese Patent Laid-Open No. 4-44856. It is described in Japanese Patent Publication No.

[0006]

However, the above-mentioned Japanese Unexamined Patent Application Publication No.
The method described in JP-A-2-179945 has the following problems. In other words, this method has a configuration in which the print start signal is input and the print start signal is input when the preliminary ejection data is not taken in during the preliminary ejection operation from the viewpoint of the hardware configuration and the preliminary ejection operation free. It can be said that this is a hardware configuration for converting into data for ejecting. In other words, due to the hardware configuration, the set preliminary ejection pattern can be driven only by data that is fixed in advance. With such a configuration, it is relatively easy to convert the hardware into data that can be ejected by all nozzles or data that ejects ink every other nozzle as described above. Although it can be configured, the hardware configuration becomes complicated when trying to correspond to various preliminary ejection data, which may lead to an increase in cost.

Also, with this configuration, it is possible to interrupt the temporary printing operation and start the preliminary ejection operation during the printing operation. Performing such a preliminary ejection operation is because the ink in the nozzle portion is not ejected for a long time.
The volatile component gradually evaporates and its viscosity becomes high, making it difficult to eject ink.If printing is performed in such a state, white streaks due to non-ejection of ink from the nozzles and ink ejection This is to prevent the occurrence of poor image quality due to poor directionality or the like. However, in the preliminary ejection data in this case, as described above, the preliminary ejection operation of the head is performed based on the preset preliminary ejection data. Therefore, for example, ink is ejected from all nozzles or every other nozzle. You can only perform operations such as ejecting ink. This means that, for example, for a nozzle group that is ejecting ink until just before interrupting the temporary printing operation,
Since the phenomenon of increasing viscosity caused by the gradual evaporation of water and volatile components of the ink does not occur, it can be said that it is not necessary to perform the preliminary ejection operation in these nozzle groups. Further, there is a drawback that ink is wastefully consumed when performing the preliminary ejection operation for the nozzle groups that do not require the preliminary ejection operation.

Further, this method has a nozzle driving number setting means, but one head chip is used for a plurality of colors,
For example, when a head cartridge in which three colors of cyan, magenta, and yellow are integrally formed, or a head cartridge in which four colors including black are further integrally formed is used, the number of pre-driving nozzles is three or four. Among them, since the ink is set by the ink that requires the largest number of pre-driving times, there is a disadvantage that waste ink is consumed for the ink that recovers with a relatively small number of pre-driving times. Further, in a low temperature environment, in order to raise the head temperature to a predetermined temperature, it is necessary to drive the nozzle a considerable number of times, and there is a disadvantage that ink is wasted further depending on the color. Normally, while such a print start preparation is being performed, there is almost no other processing control, so it can be said that the CPU that controls the operation of the entire recording apparatus can sufficiently manage the number of nozzle drive times. It is also advantageous in terms of cost to carry out.

The method disclosed in Japanese Patent Laid-Open No. 64-38246 uses a method of driving the nozzle so that the ink is not ejected or a method of ejecting the ink, and A control method is adopted in which the nozzles are driven to the extent that the ink is not ejected, and the ink is continuously ejected. This driving method is also a method that can be easily achieved with the circuit configuration of the above-mentioned Japanese Patent Laid-Open No. 62-179945. In this method as well, when the nozzles are preliminarily driven to eject ink, the number of preliminary ejection operations is set based on the ink that requires the most number of pre-driving operations, so that wasteful ink is not wasted. It has the drawback of consuming it.

In the conventional method described above, a recording head is used in which all nozzles arranged in a line are divided into a plurality of nozzle groups, and each divided nozzle group is filled with ink of a different color. In an ink jet recording apparatus that performs color printing recording by means of ink, there is a difference between ink that easily dries and ink that does not dries depending on the type of ink, and there is also a difference in the increase in ink viscosity due to evaporation of the volatile solvent of the ink. Since this increase in ink viscosity causes ejection failure, preliminary ejection operation is performed for nozzles of each ink color before printing operation. If the preliminary ejection is performed the same number of times for all the nozzles of each ink color based on the one having a large increase in ink, unnecessary ink is ejected for the ink that does not easily dry and has a small increase in the viscosity of the ink. On the contrary, if the preliminary ejection is performed the same number of times for all the nozzles of each ink color based on the ink that is hard to dry, the ink that is easy to dry will increase in viscosity of the ink.
There is a problem that defective ejection of ink is likely to occur.

Further, in an ink jet recording apparatus in which the preliminary ejection operation is finished separately for each ink color, another ink not ejected from the nozzle of the ink color which is ejected. There is a problem that color mixture occurs due to ink being scattered to the color nozzles.

Further, in performing the preliminary ejection operation, the method of applying the electrical signal having a frequency higher than the recording frequency to perform the preliminary ejection has a limit in increasing the frequency, and the frequency should be increased. However, there is a problem that the load on the recording head and the like becomes large, and the power consumption of the power source becomes large, so that it cannot be handled by a small machine. If the pre-driving time is shortened, stable and stable printing can be performed quickly. However, depending on the degree of the shortening of the pre-driving time, the current consumption of the power supply increases and the cost of the power supply increases.

The present invention solves the above problems, makes it possible to freely select a preliminary ejection pattern, facilitates additional change of the preliminary ejection pattern, and efficiently produces an optimal preliminary ejection pattern according to the head state. It is an object of the present invention to provide an inkjet recording device capable of preliminarily driving a head. A further object of the present invention is to provide an ink jet recording apparatus capable of storing print data in a memory even while head pre-driving is being performed in accordance with pre-ejection data and improving throughput.

An object of the present invention is to provide an ink jet recording apparatus capable of reducing the processing load on the CPU 3 and achieving high-speed system operation.

A further object of the present invention is to provide an ink jet recording apparatus capable of reducing the wasteful ink consumed in the preliminary ejection operation. Further, according to the present invention, when the head of the head cartridge in which one head chip is filled with a plurality of colors of ink is preliminarily driven, the number of times of preliminary ejection of each of the plurality of colors of ink can be independently set. Accordingly, it is an object of the present invention to provide an inkjet recording device capable of suppressing wasteful consumption of ink.

Further, according to the present invention, in the ink jet recording apparatus, when the recording head is preliminarily driven, the number of preliminary ejection operations for each ink is made different, and
It is an object of the present invention to provide a preliminary ejection method capable of simultaneously completing preliminary ejection operations of respective inks, preventing unnecessary ejection of hard-to-dry inks, and minimizing ink consumption in clogging recovery operations. To do. Further, it is an object of the present invention to provide a preliminary ejection method capable of preventing color mixture of inks that occurs in preliminary ejection operations of a plurality of colors of ink and performing preliminary ejection at high speed.

[0017]

Therefore, according to the present invention, an ink jet head having a plurality of nozzles arranged in a line is mounted on a carriage that moves relatively to a recording medium, and ink is ejected from the nozzle group. In an ink jet recording apparatus that prints and records one line in the arrangement direction,
First storage means for storing a plurality of preliminary ejection data for preliminarily driving the head, and second storage means for storing a specific preliminary ejection pattern data selected from the plurality of preliminary ejection data. It was equipped with.

Further, according to the second aspect of the invention, an ink jet head having a plurality of nozzles arranged in a line is mounted on a carriage that moves relatively to the recording medium, and each of the plurality of nozzles is divided into several nozzles. Nozzle group is formed, each nozzle group is sequentially delayed by a predetermined time and divided and simultaneously driven to eject ink from the nozzle group, and an ink jet recording apparatus for performing one-line print recording in the nozzle array direction is input. Preliminary ejection data storage control means for generating and storing preliminary ejection data for preliminarily driving the head based on image data, and print data for image recording or preliminary ejection data from the preliminary ejection data storage control means And a first selecting means for selecting and outputting the input image data or the head nozzle ejection data pattern for outputting. The first selection means for selecting either the preliminary ejection data for preliminarily driving the head or the print data for image recording, as the driving data for driving the nozzles of the inkjet head. The ink is supplied to the inkjet head through a selecting means.

According to a third aspect of the invention, an ink jet head having a plurality of nozzles arranged in a line is mounted on a carriage that moves relative to a recording medium, and ink is ejected from the nozzles to form one line in the nozzle arrangement direction. In the ink jet recording apparatus for performing the print recording described above, all the nozzles are divided into a plurality of nozzle groups, and a control unit that controls to eject ink preliminarily for each divided nozzle group is provided.

Further, a fourth aspect of the present invention uses a recording head in which all nozzles arranged in a line are divided into a plurality of nozzle groups and each divided nozzle group is filled with ink of a different color. In the preliminary ejection method of the inkjet recording apparatus for performing print recording, the preliminary driving is performed by changing the number of preliminary ejection operations for each ink.

[0021]

In the first aspect of the invention, an ink jet head having a plurality of nozzles arranged in a line is mounted on a carriage that moves relative to a recording medium, and ink is ejected from the nozzle group to form one line in the nozzle arrangement direction. In an ink jet recording apparatus for performing print recording of the above, first storage means for storing a plurality of preliminary ejection data for preliminarily driving a head, and specific preliminary ejection selected from the plurality of preliminary ejection data By providing the second storage unit for storing the pattern data, the head can be driven by selecting the optimum preliminary ejection data according to the head condition.

In the second invention, an ink jet head having a plurality of nozzles arranged in a line is mounted on a carriage that moves relative to a recording medium, and each of the plurality of nozzles is divided into several nozzles to form a plurality of nozzles. Nozzle group is formed, each nozzle group is sequentially delayed by a predetermined time and divided and simultaneously driven to eject ink from the nozzle group, and an ink jet recording apparatus for performing one-line print recording in the nozzle array direction is input. Preliminary ejection data storage control means for generating and storing preliminary ejection data for preliminarily driving the head based on image data, and print data for image recording or preliminary ejection data from the preliminary ejection data storage control means And a first selecting means for selecting and outputting the input image data or the head nozzle ejection data pattern for outputting. The first selection means for selecting either the preliminary ejection data for preliminarily driving the head or the print data for image recording, as the driving data for driving the nozzles of the inkjet head. The ink is supplied to the inkjet head through the selection means.

According to a third aspect of the present invention, an ink jet head having a plurality of nozzles arranged in a line is mounted on a carriage that moves relative to a recording medium, and ink is ejected from the nozzles to print one line in the nozzle arrangement direction. In an inkjet recording apparatus for recording, there is a condition of an inkjet head by having all the nozzles divided into a plurality of nozzle groups and having control means for controlling to eject ink preliminarily for each divided nozzle group. Preliminary ejection can be performed.

According to a fourth aspect of the invention, all the nozzles arranged in a line are divided into a plurality of nozzle groups, and color printing is performed by using a recording head in which each divided nozzle group is filled with ink of a different color. In the preliminary ejection method of an inkjet recording apparatus that performs recording, wasteful ejection of ink can be eliminated by performing preliminary drive by changing the number of preliminary ejection operations for each ink.

[0025]

【Example】

 [Example 1]

FIG. 1 is a system configuration diagram showing a first embodiment of an ink jet recording apparatus according to the present invention. The inkjet recording apparatus 1 according to the present invention includes a CPU 3 and
Work RAM 4, font ROM 5, program R
OM6, EEPROM7, interface 8,
Operation panel 9, memory control unit 10, image RAM
11, a head control unit 12, a recording head 13, a motor control unit 14, a motor 15, an I / O control unit 16,
It is composed of a sensor 17 and a common bus 18.

The ink jet recording apparatus 1 is connected to the host computer 2 and exchanges data between them. CPU3 is work RAM4, font ROM
5, it is connected to the program ROM 6 and the EEPROM 7, and operates according to the program stored in the program ROM 6 while referring to the set values stored in the EEPROM 7, for example, the correction data for improving the image quality. The CPU 3 is also connected to the common bus 18, and controls each unit in the inkjet recording apparatus 1 through the common bus 18. Work RAM4 is CPU3
It is used as a recording area for work, and is also used for storing information and the like in various systems. The font ROM 5 stores image format data of characters to be printed.

The program ROM 6 stores a program for instructing the operation of the CPU 3. EEPROM
Reference numeral 7 denotes a non-volatile memory, which retains its contents even when the power is cut off, so that correction data for improving image quality and various setting information such as the operation mode of the system are stored. These data may be set using the operation panel 9.

The interface 8 is connected to the common bus 18 and the host computer 2, and the host computer 2
Send and receive data directly with. The operation panel 9 is connected to the common bus 18, receives various inputs from the user, and displays various states and messages to the user.

The memory control unit 10 includes an image RAM 1
1, connected to the common bus 18 and the head controller 12,
It controls the image RAM 11. Data to be recorded is stored in the image RAM 11 in the form of an image.
The image RAM 11 can be divided into areas corresponding to the recording heads.

The head controller 12 is connected to the recording head 13, the common bus 18, and the memory controller 10, and controls the recording head 13. The control of the recording head 13 includes at least control of ink ejection timing from each nozzle of each recording head, ink temperature, and the like.

The recording head 13 is composed of a plurality of heads having N nozzles. For example, in the case of color printing, it is composed of four recording heads of black (K), cyan (C), magenta (M) and yellow (Y). It is also possible to configure two recording heads by dividing one of the recording heads for cyan, magenta, and yellow into three nozzle groups and allocating them, and making one recording head of black.

The motor controller 14 is connected to the motor 15 and the common bus 18 and controls the motor 15. The motor 15 relatively moves the carriage on which the recording head 13 is mounted and a recording medium, for example, recording paper.

The I / O control unit 16 is connected to the various sensors 17 and the common bus 18, and controls the various sensors 17 and acquires detection data.

The sensor 17 includes, for example, paper edge detection, paper width detection or ink amount detection. Common bus 18
Is a CPU 3, an interface 8, an operation panel 9, a memory controller 10, a head controller 12, a motor controller 1.
4 and the I / O control unit 16 are connected to each other to transmit various data and control signals.

Although the above-mentioned functions are functionally separated, the image RAM 11 and the work RAM 4 are the same RA.
Modifications such as M are also possible.

The operation of the system shown in FIG. 1 will be described. CPU
3 operates in accordance with the program stored in the program ROM 6 while referring to the set values and the like stored in the EEPROM 7. At that time, the work RAM 4 is used if necessary. The setting values and the like stored in the EEPROM 7 are set using the operation panel 9. Also, C
The PU 3 obtains information from the sensor 17 via the I / O control unit 16, checks whether recording is possible, and instructs the motor control unit 14 to move the carriage or convey the recording paper. Then, the recording position is adjusted.

When data to be recorded, such as image information or character code, is sent from the host computer 2, the interface section 8 receives the information and transfers the received data to the CPU 3. The CPU 3 converts the received data into recordable image data, for example, a bitmap according to the print format. For example, if the received data is a character code, the font ROM 5 is used to convert it into image data of the character. The converted image data is stored in the image RAM 11 via the memory control unit 10.

When the image data is stored, the head drive pulse width and drive operation mode are determined based on the temperature detected by the printer main body and the temperature detection element incorporated in each head, and various settings are made. Head control unit 1
Set to 2. Especially when the head temperature is low immediately before printing,
Since the ink ejection characteristics are adversely affected, the operation of raising the temperature of the head to the optimum temperature range in which the ink ejection characteristics are relatively stable is performed. Next, the CPU 3 causes the motor control unit 14
The carriage is requested to be moved and scanning is performed. An encoder for generating print timing is attached to the carriage on which the recording head 13 is mounted, and the print timing according to the scanning speed of the carriage is input to the CPU and the head controller 12. The CPU 3 determines the print position based on the print timing, and supplies the print control gate signal to the head controller 12.

The head control section 12 outputs a head drive signal to the recording head 13 in response to the gate signal for printing permission and the printing timing signal. An interrupt is generated from the memory control unit 10 and input to the CPU 3. Receiving this interrupt signal, the CPU 3 requests the motor controller 14 to convey the recording medium of the print recording width and rescan the carriage. When one scan operation of the carriage is completed, the transport roller conveys the recording medium 23 by a predetermined amount. In this way, printing for one scan is performed a plurality of times until the print recording operation in the transport direction of the recording medium is completed. Here, the head temperature and the environmental temperature are detected before the start of printing for one scan, and the head drive pulse and the drive operation mode are determined each time.

When the printing operation on one recording medium is completed in this way, the CPU 3 requests the motor control section 14 to eject the recording medium and moves the carriage to the position of the cap mechanism section again. , Cap the recording head unit to prevent ink from running dry and wait until the next printing.

FIG. 2 schematically shows the periphery of the carriage of the ink jet recording apparatus. For example, the recording head unit 21 including four recording heads of black, cyan, magenta, and yellow is mounted on the carriage 22, and is scanned orthogonally to the feeding direction of the recording medium 23. The transport roller 24 moves the recording medium 23 in the feeding direction. The cap mechanism unit 25 is located outside the range of the recording medium 23, which is the range of movement of the carriage 22. Each of the recording heads 21 or a plurality of recording heads 21 are integrally configured to be attachable to and detachable from the carriage 22. Further, the recording head unit 21 is provided with a plurality of nozzles.

Printing is performed by ejecting ink from nozzles while scanning the carriage 22 left and right. In this printing, when a plurality of recording head units 21 are mounted on the carriage 22, ink is ejected from each recording head unit 21 and ink dots are overlapped to form an image.

A color image can be formed by using, for example, four recording heads of black, cyan, magenta and yellow as the plurality of recording head units 21.

When one scan operation of the carriage 22 is completed, the transport roller 24 conveys the recording medium 23 by a predetermined amount. Repeat this operation,
Printing on one sheet of recording paper is completed. One recording medium 23
When the printing on the recording head unit 21 is completed, the carriage 22 moves to the position of the cap mechanism portion 25 again.
Cap and wait until the next print.

In this embodiment, the sub-scanning by the relative movement of the recording medium and the head unit is moved on the recording medium side, but the carriage 22 may be moved. Further, this movement amount can be performed only for one print width or a predetermined line feed width, or can be sent collectively for a scan of only blanks. Further, for example, when feeding the recording medium or positioning the recording medium when recording according to a predetermined format, the C
The recording medium can be moved according to the instruction from the PU 3, and the movement amount can be changed according to the instruction from the host computer 2.

FIG. 3 is a block diagram showing a first embodiment of the head controller 12 for controlling the drive of the head of the ink jet recording apparatus 1 of the present invention. The head control unit 12 includes an adjacent nozzle group print period value storage unit 31, an adjacent nozzle group print period setting counter 32, and a print timing control unit 33.
A print drive pulse generator 34, a print dot number counter controller 35, and a print drive pulse width setting counter 36.
And a print drive pulse width set value storage unit 37 and a print data processing unit 38.

The head drive control operation section constitutes a part of the head control section 12 shown in FIG. As shown in FIG. 6, the head is formed by dividing a plurality of nozzles into several nozzle groups, and a plurality of nozzle drives provided in the head is driven by each nozzle in the divided nozzle group. Are driven simultaneously, and each nozzle group is sequentially driven from either one end side. In the following description, this nozzle group will be referred to as a divided simultaneous drive nozzle group.

The adjacent nozzle group period value storage means 31 holds the adjacent nozzle group printing period value corresponding to the time for driving between the divided and simultaneously driven nozzle groups. This value is set by a signal WR when data is sent from the CPU 3 or the like. The adjacent nozzle group print cycle setting counter 32, based on the adjacent nozzle group print cycle value Tc held in the adjacent nozzle group print cycle value storage unit 31, follows the instruction of the print timing control unit 33 and outputs the cycle time between the adjacent nozzle groups. A signal is generated and input to the print timing control unit 33 and the print dot number counter control unit 35. The print dot number counter control unit 35
When the cycle time signal from the adjacent nozzle group print cycle setting counter 32 is received, the number of nozzle groups is counted, and when the total number of nozzles is reached, a signal of the number of print nozzle groups indicating to that effect is sent to the print timing control unit 33. To notify.

The print timing control unit 33 generates various timing signals. A clock signal and a gate signal from another control unit, a cycle time signal from the adjacent nozzle group print period setting counter 32, and a signal of the number of print nozzle groups from the print dot number counter control unit 35 are received to set the adjacent nozzle group print period. The counter 32 and the print drive pulse width setting counter 36 are instructed to take in the count value and the count clock is supplied, and the print drive pulse generator 34 is instructed to start driving, and the print data processing unit 38 is instructed. On the other hand, the print data transfer clock is supplied and the same signal is output to the recording head 13.

The print drive pulse generator 34 receives the drive start instruction from the print timing controller 33 and the count end signal of the print drive pulse width setting counter 36, and controls the drive pulse on / off of the print head. The print drive pulse width setting counter 36, based on the count clock supplied from the print timing control unit 33,
Counting is performed until the drive pulse width data is reached, and an end signal is supplied to the print drive pulse generator 34.

The print drive pulse width set value storage means 37 stores the drive pulse width data Tp set in the print drive pulse width setting counter 36. This data is CP
It is sent from U3 or the like and stored from the signal WR.

FIG. 4 is a block diagram showing an embodiment of the internal circuit of the recording head 13 of the ink jet recording apparatus of the present invention. The internal circuit of the recording head 13 includes a 4-bit shift register 50, a 4-bit latch 51, a 32-bit shift register 52, heaters R1 to R128, switching transistors T1 to T128, and inverters IV1 to IV.
IV128 and NAND circuits NA1 to NA128 are connected as shown in the figure.

In FIG. 4, the number of nozzles in the entire head is 128.
The number of nozzles in one nozzle group is 4, and the number of nozzles is 3
It is divided into two nozzle groups and driven. Each nozzle is provided with heaters R1 to R128, and heaters R1 to R128 are provided.
One end of is connected to a common power source and a voltage Vh is applied. The other end is the respective switching transistor T
It is connected to the ground through 1 to T128, and when the switching transistor is turned "ON", a current flows through the heater to drive the nozzle. “ON” and “OFF” of each switch transistor T1 to T128 is NA
This is performed by the signal of the logical product of the drive pulse and the print data input to the ND circuits NA1 to NA128. The signal of the logical product is the NAND circuits NA1 to NA128 and the inverter IV.
1 to IV128.

FIG. 5 shows an example of the timing for driving the internal circuit of the recording head 13 shown in FIG. Here, data such that the adjacent nozzle group print cycle tc (sec) and the nozzle drive pulse width tp (sec) are stored in the adjacent nozzle group print cycle value storage means 31 and the print drive pulse width set value storage means 37, respectively. Remembered

The 4-bit shift register 50 sequentially receives the print data Dp sent from the print data processing unit 38 in synchronization with the print data transfer clock Tc output from the print timing control unit 33, and one nozzle group Outputs parallel print data corresponding to the four nozzles inside. The 4-bit latch 51 temporarily holds the print data output from the 4-bit shift register 50 in synchronization with the drive pulse Tp sent from the print drive pulse generator 34, and outputs the print data to the nozzle. The print data output from the 4-bit latch 51 is input to the NAND circuit corresponding to each nozzle group. That is, the first data line output from the 4-bit latch 51 corresponds to the first nozzle of the first nozzle group N
AND circuit NA1, NAND circuits NA5, ... Corresponding to the first nozzle of the second nozzle group, and NAND circuit NA125 corresponding to the first nozzle of the 32nd nozzle group. The second data line is connected to the NAND circuit corresponding to the second nozzle of each nozzle group. The same applies to the third and fourth data lines. The 32-bit shift register 52 has an output line Bn corresponding to each nozzle group, and this output line is sequentially switched by a shift operation.
A nozzle group to be driven is sequentially selected from the individual nozzle groups, and a NAN corresponding to each nozzle in the driven nozzle group is selected.
Input a drive pulse to the D circuit. The drive pulse Tp is input from the print drive pulse generator 34 to the 32-bit shift register 52, and when the drive pulse Tp is at "H level", the signal to the nozzle group selected for that period is " H level ”. In addition, the drive pulse Tp is "L
When it becomes "level", it is detected, the position of the selected output line is shifted, and the next adjacent nozzle group is driven.

In this way, 128 nozzles have 4
It is divided into nozzle groups for each book, and a maximum of four nozzles are simultaneously driven according to the image data. Further, each nozzle group is sequentially driven according to the drive pulse Tp, and by driving the nozzle group 32 times, 128 nozzles are driven,
Image recording is performed in the nozzle array direction.

Next, the preliminary ejection operation of the recording head 13 will be described. As described above, when the non-printing time of the inkjet recording apparatus 1 becomes long, the ink viscosity of the nozzle portion of the recording head 13 becomes high. When printing is performed in such a state, at the start of printing, the ink is not ejected or the ejection direction of the ink is disturbed, resulting in deterioration of image quality.

For such a problem, the head is preliminarily driven before the start of printing to eject the ink of high viscosity to prevent the deterioration of image quality.

Further, even if paper powder, dust, or the like adheres to the nozzle portion of the recording head 13, defective ink ejection occurs and the above-described image quality defect occurs. It is generally performed to perform preliminary ejection of the head.

Further, as the recording head 13, a head having a structure in which a plurality of nozzles are divided into a predetermined number of nozzle groups, and the respective divided nozzle groups are filled with inks of different colors, respectively. When used, ink may flow out from the nozzle to the nozzle surface due to vibration or shock during scanning of the carriage, and may mix with other adjacent ink. This causes a problem from the viewpoint of color reproducibility and may lead to poor image quality. Therefore,
Even during the printing operation in the above-mentioned configuration, the preliminary ejection of the head is periodically performed.

In this way, the preliminary ejection of the recording head 13 is performed in various cases. Preliminary ejection performed in each case has a different purpose depending on the case. Therefore, the preliminary ejection pattern can be an optimal pattern from various preliminary ejection patterns depending on the situation where the head is placed. The configuration is selectable.

FIG. 6 shows an example of the head preliminary ejection pattern. The head is composed of, for example, 128 nozzles arranged in the vertical direction, and each nozzle is divided into a total of 32 nozzle groups of 4 nozzles. Black circles indicate nozzles that eject, white circles indicate nozzles that do not eject. Configuration number (1) is
A pattern for ejecting ink every other nozzle is shown. Ink is ejected from the first and third nozzles, but it is also possible to adopt a reverse pattern in which ink is ejected from the second and third nozzles. Configuration number (2)
Shows a pattern in which ink is ejected every four nozzles, that is, every one nozzle group. The pattern can also be the reverse pattern as described above. Configuration number (3) indicates a pattern in which ink is ejected from all nozzles.

The configuration number (1) and the configuration number (2) are
It is used for the preliminary ejection pattern during the printing operation, or the configuration number (3) is used, for example, as the head preliminary ejection pattern for the clogging recovery operation under the low temperature environment. Although not shown here, the recording head 13 is configured such that a plurality of nozzles are divided into a predetermined number, and the respective divided nozzle groups are filled with inks of different colors. When using the above head, since the nozzle part that is adjacent to the ink of another color is likely to cause color mixing of the ink, the nozzle part that is adjacent to the nozzle that is filled with the ink of another color is used. A preliminary discharge pattern is used such that only preliminary discharge is performed.

Such various head preliminary ejection pattern data are stored in advance in the program ROM 6 or the like.

FIG. 7 is a flow chart of the head preliminary ejection control operation. First, the head control unit 12 may, for example, immediately after turning on the power or divide a plurality of nozzles into a predetermined number of nozzles.
When using the recording head 13 in which the respective divided nozzle groups are filled with inks of different colors, when the environmental temperature is low, or when waiting for long-term printing, etc. Then, the state in which the recording head 13 is placed is confirmed (S1). Next, the head controller 12 selects an optimum preliminary ejection pattern from various head preliminary ejection patterns in the program ROM 6 based on the head state data grasped in step S1 (S2).

The data of the area in which the optimum preliminary ejection pattern data selected in step S2 is stored is transferred into the image RAM 11 (S3). Image RAM
Reference numeral 11 denotes a storage element that stores image data when performing a normal printing operation, and since a storage area for the maximum width in the carriage scanning direction and a storage area for the nozzle width are secured,
For example, it is possible to transfer the preliminary ejection pattern data for only one line or the preliminary ejection pattern data for a plurality of lines. When transferring the preliminary ejection pattern data for a plurality of lines, it is of course possible to transfer different preliminary ejection pattern data for each line. After the transfer operation of the preliminary ejection pattern data in step S3 is completed, the head preliminary ejection start operation is performed (S4).

Next, in step S4, the head state after the pre-ejection starting operation is executed is confirmed (S
5). Next, when it is determined that the number of head preliminary ejections is insufficient, the process returns to step S2 and the same control operation is executed again. If it is determined that the head preliminary ejection is sufficient, the process proceeds to the next control (S6).

In the present invention, the image RAM 11 is used as the second storage means. However, for example, the second storage means is not used but the program ROM which is the first storage means.
It is also possible to directly transfer the preliminary ejection pattern data from 6 to the head controller 12 to perform the preliminary ejection operation. In this case, the CPU 3 transfers the data. However, in such a configuration, the CPU 3 always needs to transfer the preliminary ejection data at high speed in accordance with the head driving operation, and there is a problem that other control cannot be performed sufficiently.

In the present invention, the image RAM 11 is used as the second storage means, and the preliminary ejection operation is automatically performed among the memory control unit 10, the image RAM 11 and the head control unit 12. Therefore, the program ROM 6 is released to the CPU 3,
Since the CPU 3 can perform other control operations in parallel with the head preliminary ejection operation described above in accordance with the program of the program ROM 6, it is possible to reduce the load on the CPU 3 and speed up the operation of the inkjet recording apparatus.

[Embodiment 2]

FIG. 8 is a block diagram showing a second embodiment of the head drive controller of the ink jet recording apparatus 1 according to the present invention. The head drive control unit 12B of this embodiment is different from the drive control unit 12 of the first embodiment shown in FIG. 3 in that the parallel-serial exchange means 39 and the second selection means 40 are used.
The difference is that the preliminary ejection data recording control unit 41 and the first selecting unit 42 are provided, and the other components have the same configuration and operation. Therefore, the description of the common operation is omitted, and the operation of the part peculiar to the present embodiment will be described below.

The data from the CPU 3 is input to the parallel-serial conversion means 39, converted into serial data, and output to the second selection means 40. Memory control unit 10
The image data Di from is input to the print data processing unit 38 and also to the second selecting unit 40. The second selection means 40 selects either the image data Di from the memory control unit 10 or the serial data from the CPU 3 and outputs it to the preliminary ejection data storage control unit 41. The setting data for selecting which is sent from the CPU 3 or the like and stored by the signal WR.

The preliminary ejection data storage controller 41 stores the data output from the second selecting means 40 and performs image processing. The data stored here is output to the first selecting means 42 in synchronization with the print data transfer clock Tc. The first selection means 42 performs an operation of selecting either the data output from the print data processing unit 38 or the data output from the preliminary ejection data storage control unit 41 and outputting the selected data as print data Dp. The setting data indicating which to select is sent from the CPU 3 or the like, and the signal W
Stored by R.

FIG. 9 is a timing chart when the preliminary ejection is performed. During the preliminary ejection, since there is no image data, the image data read clock and image data signals are not output. In this example, since all nozzles perform preliminary ejection, the print data are all at "high level" in synchronization with the transfer clock, and preliminary ejection is performed from all nozzles in response to the drive pulse.

Based on the operation flows of FIGS. 10 to 12, the parallel-serial conversion means 39 and the second selection means 40 are provided.
Then, the control operations of the preliminary ejection data storage control unit 41 and the first selection unit 42 will be specifically described.

When the power of the system of the ink jet recording apparatus 1 is turned on, the clogging recovery control operation mode of the recording head 13 is started. In this mode, the recording head 13 is preliminarily driven in order to prevent defective printing due to the presence of ink having high viscosity in the nozzle portion of the recording head 13. First, the CPU 3 sets selection data to the first selection unit 42 so that the first selection unit 42 selects and outputs the output of the preliminary ejection data storage control unit 41 (S10). Next, the second selection means 4
The selection data is set to the second selection means 40 so that 0 selects and outputs the output of the parallel-serial conversion means 39 (S11).

The CPU 3 confirms various head states such as the head leaving time and the environmental conditions of the system of the ink jet recording apparatus 1 (S12). Based on the head state confirmed in step S12, head drive parameters corresponding to various head states stored in the program ROM 6, such as head drive pulse width, print frequency, and head nozzle ejection data pattern, for example, An operation of selecting the optimum data from the ejection data of all nozzles or the ejection data of every other nozzle is performed (S13).

Based on the selected data, the adjacent nozzle group print cycle value tc at the time of head pre-driving is stored in the adjacent nozzle group print cycle value storage means 31 (S14). Next, the print drive pulse width value tp during head pre-driving is stored in the print drive pulse width setting storage means 37 (S15).
The CPU 3 outputs the head nozzle ejection data pattern selected in step S13 to the parallel-serial conversion means 39 (S16). The parallel-serial conversion means 39 also outputs a serial data transfer clock for words each time this data is written. In step S11, the second selecting means 40 is set so as to select and output the output of the parallel-serial converting means 39.
The 28 head nozzle ejection data patterns are stored in the preliminary ejection data storage controller 41 (S17). Here, the data storage unit of the preliminary ejection data storage control unit 41 is
Although 128 pieces of data can be stored, for example, if four nozzles are simultaneously driven, a storage unit that can store at least four head nozzle ejection data patterns may be used. In this case, these four data are repeatedly output to the head as print data.

Since all the conditions for pre-driving have been set, the CPU 3 issues the pre-driving trigger shown in FIG. 9B (S18). In the pre-driving, the nozzle driving is performed once for each nozzle per trigger.

FIG. 9 shows an example of the timing when the head pre-driving operation is performed. The adjacent nozzle group printing cycle here is tc (sec), and the nozzle drive pulse Tp (see FIG. 9).
The pulse width of (g)) is tp (sec). here,
In synchronization with the transfer clock Tc to the head 13 (FIG. 9 (e)), 128 pieces of data of the preliminary ejection data storage control unit 41 are the print data Dp (FIG. 9).
(F)) is output. Here, the print data Dp is "high level" data because it is a pre-driving pattern in which all nozzles are driven. The pre-driving frequency in the pre-driving performed subsequently follows the head driving parameters selected in step S13 as described above.

Next, according to the data set in the preliminary discharge data storage controller 41, it is determined whether or not the preliminary discharge has been executed a predetermined number of times (S19). If the preliminary discharge has not been executed the predetermined number of times, the process returns to step S18,
The nozzle drive is subsequently executed. Next, when the predetermined number of preliminary ejections have been completed, the state of the head is checked again,
Judgment of whether or not separate discharge data is required, that is,
It is determined whether the pre-driving operation is to be executed again or to be ended (S20). When the state of the head is a state in which the pre-driving operation needs to be executed again, the process returns to step S13 and new data corresponding to the state of the head is set to perform similar pre-ejection drive control. When it is not necessary to re-execute the preliminary drive operation, the clogging recovery control operation mode is terminated,
Switch to print mode.

The above parallel-serial conversion means 39
By the control operations of the second selecting unit 40, the preliminary ejection data storage control unit 41, and the first selecting unit 42, the preliminary ejection in the clogging recovery control operation mode of the recording head 13 is performed.

Next, the control operations of the parallel-serial conversion means 39, the second selection means 40, the preliminary ejection data storage control section 41, and the first selection means 42 during the printing operation are shown in FIGS.
0 and the operation flow of FIG. 12 will be described.

First, the CPU 3 sets the adjacent nozzle group print cycle value tc in the print drive in the adjacent nozzle group print cycle value storage means 31 (S21). Next, the CPU 3 sets the print drive pulse width tp in the print drive mode in the print drive pulse width value storage means 37 (S22). The head drive parameters for the adjacent nozzle group print cycle value tc and print drive pulse width tp may be the same as the parameters for head preliminary drive. Next, the selection data is set to the first selection unit 42 so that the first selection unit 42 selects and outputs the data of the print data processing unit 38 (S2).
3).

When the above data is set, the printing operation is started, the recording medium 23 is fed, and the recording medium is set at a predetermined position (S24). As soon as the print data is set, one-scan printing operation is performed (S2
5). When printing for one scan is completed, it is determined whether or not there is print data for the next scan (S26), and when there is print data for the next scan, it is determined whether or not the elapsed time from the end of the preliminary ejection mode has exceeded t _2. (S27). If the result of this determination is that the time t ₂ has not been exceeded, the flow returns to step S24 to start printing for the next scan.

In parallel with this printing operation, the measurement of the time t ₁ from the final point of the preliminary ejection operation is started (S28).
This measurement operation is performed by the CPU 3 or the like. Between the start of measurement of less than the predetermined time t ₁ is to continuously execute the measurement operation, when a predetermined time t ₁ from the start of measurement has elapsed, so that the second selection means 40 selects and outputs the image data Is set to the second selection means 40 (S2).
9). Next, the preliminary ejection data storage control unit 41 samples the print data corresponding to each nozzle while synchronizing with the transfer clock to the head 13 (S3).
0). Based on the sampling data obtained in step S30, while detecting whether each nozzle is a nozzle that ejects ink or a nozzle that does not eject ink, non-ejection data that does not print on the ejection nozzle is stored. Then, for the non-ejection nozzles, replacement control of data for storing ejection data for printing is performed (S31). This sampling operation is performed by the preliminary ejection data storage control unit 41, and is continuously performed until the preliminary ejection time t ₂ of step S27 has elapsed (S27). As a result, the ejection data is stored as the data corresponding to the nozzles that have not ejected ink once after the lapse of t ₁ hours after the small amount of the preliminary ejection operation until t _{2, and} at the same time the ink is ejected even once during this period. The non-ejection data is stored as the data corresponding to the ejected nozzles.

The preliminary ejection time t ₂ used in step S27 defines the time until the ink in the head nozzle portion runs out. This is because when there is a situation in which the print recording exceeds one sheet, in the nozzles in which the ink ejection operation is not performed once until the time t ₂ is exceeded, there are nozzles that cannot be ejected due to the dry ink in the subsequent printing. Occurrence or trouble such as disorder of ink directionality,
There is a problem that the print quality is remarkably deteriorated. In order to deal with this problem, if the printing operation is being performed even after the lapse of time t ₂ , the temporary printing operation is stopped and the preliminary ejection control operation is performed to eliminate the malfunction of the nozzle.

If it is determined in step S26 of detecting and determining the next scan print data that there is no next scan print data, the process proceeds to the preliminary ejection mode control (preliminary drive mode) (S32). In the preliminary ejection mode control, the operation according to the operation flow of FIG. 10 is executed according to the head preliminary ejection control described above. Here, the CPU 3
The printing pattern at the end of printing is retrieved from the program ROM 6 and stored in the preliminary ejection data storage control unit 41. After that, the first selecting means 42 and the second selecting means 40 are similarly selected.

In step S27, the preliminary discharge time t ₂
If it is determined that the time has elapsed, the first selection unit 42 selects the output of the preliminary ejection data storage control unit 41 and outputs the selected output.
The selection data is set for 2 (S33). Hereinafter, as shown in FIG. 12, a trigger for the preliminary ejection operation is issued, the head preliminary drive mode is entered, and the preliminary drive of the head is executed (S34). The print data output to the recording head 13 is the data stored in the preliminary ejection data storage control unit 41, but this data is not printed even once during the printing operation for (t2-t1) time. Data for driving the nozzles. Next, when one pre-driving is completed, it is judged whether or not the number of times of the preliminary ejection operation is performed a predetermined number of times (S35), and the head preliminary ejection operation is performed by returning to step S34 until the number of times of the pre-driving operation is completed a predetermined number of times. . Further, the preliminary ejection operation may be continuously performed with a predetermined drive pattern. With such a configuration, the ink consumed by the pre-driving during the printing operation is the ink ejected from the nozzle that has never been printed during the printing operation for the time (t2-t1). Therefore, it is possible to reduce the amount of wasteful ink consumption as compared with the pre-driving in which ink is ejected from all the normal nozzles.

When this pre-driving operation is completed, it is determined whether or not there is print data for the next scan (S36). As a result of the determination, when there is no print data for the next scan, the process moves to the preliminary drive mode in step S32 of FIG. 11 and the series of operations ends. When it is determined in step S36 that print data is present, the selection data is set in the first selection means 42 so that the first selection means 42 selects and outputs the output of the print data processing unit 38. Yes (S37).

Next, after the operation of clearing the ejection data stored in the preliminary ejection data storage control unit 41 is performed (S38), the process proceeds to step S24 of FIG. 11 to restart the printing operation, After that, a similar series of control operations are performed.

In this series of operations, the measurement of time t1 and time t2 is started after the completion of the preliminary ejection operation performed in step S34. In this way, the time measurement is started each time the preliminary ejection operation is completed.

As described above, by providing the head control unit 12 with the first selection unit and the second selection unit, and the preliminary ejection data storage control unit corresponding to the maximum number of nozzles, various operations can be performed. It is possible to deal with the preliminary ejection pattern. Although it is possible to generate the preliminary ejection pattern from the reference pattern by hardware, the hardware configuration may be complicated in order to deal with various patterns, and there are many problems.

Further, in the preliminary discharge data storage controller,
To reduce waste ink consumed in the preliminary ejection operation by adding a mode to detect non-printing nozzles by performing print data storage operation during printing operation and to drive only those nozzles during preliminary ejection operation. Became possible. Further, the preliminary ejection pattern storage control unit is replaced with the head control unit 12.
Since the internal structure is provided, the print data can be expanded in the image RAM 11 even during the preliminary ejection drive of the head 13, and the throughput of the printer system 1 can be improved.

[Example 3]

FIG. 13 is a diagram showing one example of the pre-driving operation mode of the head drive control section in the ink jet recording apparatus 1 according to the present invention. 13A shows the structure of the recording head, FIG. 13B shows a drive pulse Tp, FIG. 13C shows a print pulse for pre-driving only block 1, and FIG. 13D shows a print pulse for pre-driving only block 2. (E) is a print pulse for pre-driving only block 3, (f) is a print pulse for pre-driving only block 4, (g) is a print pulse for pre-driving block 1 and block 4,
(H) shows a print pulse for pre-driving only blocks 2 and 3, and (i) shows a print pulse for pre-driving all blocks.

As shown in FIG. 13A, the recording head 13 to which the operation mode of this embodiment is applied is the head 12
8 nozzles are divided into 4 blocks, 1 block 3
It is characterized by having two nozzles. That is, in the recording head 13 used in this embodiment, the nozzle numbers 1 to 32 are the block 1, the nozzle numbers 33 to 64 are the block 2, the nozzle numbers 65 to 96 are the block 3, and the nozzle numbers 97 to 97. Blocks 4 to 128 are configured.

That is, this embodiment is a method of controlling the above-described four divided recording heads 13 by using the head control units 12 and 12B shown in FIG. 3 or 8. For example, the CPU 3 sets block data for ejecting only the nozzles 32 from the nozzles 1 to the print dot number counter control unit 35 when operating only the block 1 during the head preliminary drive operation. When the head preliminary drive operation is started based on this data, the print dot number counter control unit 3 is operated only while the block 1 is being driven.
An output signal of “high level” from 5 is output to the print data processing unit 38.

Since the print data processing unit 38 has confirmed that the data input during the head pre-driving is the data for the preliminary ejection operation, this data is supplied to the recording head 13 as print data. . In this way, as shown in FIG. 13C, print data for driving the nozzles 1 to 32 of the block 1 is output, and the preliminary ejection operation of ink from the nozzles 1 to 32 is executed. .

Similarly, for example, by setting the block data for pre-driving from the CPU 3 to the print dot number counter control unit 35, head pre-driving control for only blocks 2, 3, and 4 can be performed. FIG.
3 (d) is print data for driving only the block 2, (e) is block 3 and (f) is the print data for driving each block.

Furthermore, it is also possible to carry out the preliminary discharge operation by combining a plurality of blocks. In FIG. 13G, the blocks 1 and 4 are preliminarily driven, and in FIG. 13H, the blocks 2 and 3 are preliminarily driven. Print data. Further, FIG. 13 (i) shows print data for pre-driving blocks 1 to 4, that is, all nozzles, and block data for pre-driving the previous block is set in the print dot number counter control unit 35. It is an example of the operation in the case of.

As described above, by providing the head controller with the structure capable of arbitrarily generating the print data for each block, for example, the block 1 shown in FIG. It is advantageous when a head cartridge in which the same head chip is filled with a plurality of different color inks such as magenta ink, cyan ink in block 3 and black ink in block 4 is used. When only the control operation of driving all the nozzles with such a head can be performed, the number of preliminary ejections of the nozzles is set to the maximum value of the number of preliminary ejections required to recover the clogging of each ink. However, this has a drawback that ink is wastefully consumed for ink that recovers with a relatively small number of preliminary ejections.
However, by using the configuration of the present embodiment, the number of preliminary ejections required for each ink is independently controlled, so that it is possible to suppress wasteful consumption of ink by head preliminary drive as much as possible.

[Embodiment 4]

As shown in the third embodiment, all the nozzles arranged in a line are divided into a plurality of nozzle groups, and the divided nozzle groups are filled with ink of different colors. When performing color print recording with
If there is a difference in the easiness of drying depending on the type of ink, such as an ink that easily dries and an ink that does not dries easily, a difference in the viscosity of the ink also occurs due to evaporation of the volatile solvent of the ink. Since this increase in ink viscosity causes ejection failure, a preliminary ejection operation is performed for each ink color nozzle before the printing operation. When the preliminary ejection is performed the same number of times for all the nozzles of each ink color, unnecessary ink is ejected for the ink that does not easily dry and has a small increase in the viscosity of the ink. On the other hand, if preliminary ejection is performed the same number of times for all nozzles of each ink color based on ink that is difficult to dry, ink ejection failure tends to occur with ink that tends to dry and has a large increase in ink viscosity. was there.

When performing the preliminary ejection operation, when the preliminary ejection operations are simultaneously started using the three color inks having different preliminary ejection times, the three color inks respectively terminate the ejection operation. . At this time, there is a problem that color mixture occurs due to ink being scattered from the ink color nozzle that is performing the ejection operation to another ink color nozzle that has completed the ejection operation.

Further, when performing a preliminary ejection operation, the method of applying an electric signal having a frequency higher than the recording frequency has a limit in increasing the frequency, and the load on the recording head and the like becomes large. In addition, the current consumption of the power supply is so large that it cannot be supported by small machines. If the pre-driving time is shortened, stable and stable printing can be performed quickly. However, depending on the degree of the pre-driving time, the current consumption of the power supply becomes large and the cost of the power supply increases.

A method in which all the nozzles arranged in a line are divided into a plurality of nozzle groups, and each of the divided nozzle groups is filled with ink of a different color to perform color print recording. Then, if the ink of a plurality of colors filled in the plurality of divided nozzle groups is, for example, three colors of cyan, magenta, and yellow, the number of preliminary ejection operations is set to the nozzle group filled with cyan. Is set to Nc times, the nozzle group filled with magenta is set to Nm times, and the nozzle group filled to yellow is set to Ny times. Here, for example, when cyan is an ink whose base is also easy to dry, and magenta is the next easiest to dry, and yellow is the least dry ink, the number of preliminary ejections is based on cyan, which is the easiest dry ink, Set as Nc>Nm> Ny. In this way, the number of times of preliminary ink ejection is determined by the CPU 3
The recording head 13 is preliminarily ejected by an operation such as the above.

A fourth embodiment of the present invention will be described with reference to the flowchart of the preliminary discharge operation according to the set number of preliminary discharges in FIG. The present embodiment relates to the preliminary ejection operation of the recording head using the three color inks as shown in the third embodiment.

When the preliminary ejection operation mode is entered, the number of preliminary ejections is set to Nc, Nm and Ny for each of cyan, magenta and yellow inks (S).
40). Next, the preliminary ejection operation is started from cyan, which requires the largest number of preliminary ejections of the three color inks (S41). At this time, since only the cyan-filled nozzle group performs the ejection operation, since the preliminary ejection of magenta and yellow is not performed, the driving frequency f ₁ (kH) higher than that in the case of performing the preliminary ejection of all the nozzles is used.
In z), preliminary ejection of cyan is performed. Next, it is determined whether or not the difference between the number of preliminary ejections of cyan and the number of preliminary ejections set for magenta (Nc-Nm times is completed (S4).
2).

The number of times cyan is ejected is the difference number (Nc-N
When m) is reached, the preliminary ejection operation of magenta is started, and the preliminary ejection operations of cyan and magenta are simultaneously performed (S43). At this time, since the ejection operation is performed only for the nozzle group filled with cyan and magenta, it is higher than the case where the preliminary ejection is performed for all the nozzles because the preliminary ejection of yellow is not performed, and is higher than the f ₁ (kHz). Preliminary ejection of cyan and magenta is performed at a low drive frequency f ₂ (kHz). Further, it is determined whether or not the preliminary ejection of magenta has finished a difference number (Nm-Ny) from the number of preliminary ejections set for yellow (S44).

The number of magenta discharges is the above-mentioned difference (Nm-
When it reaches Ny), the preliminary ejection operation for yellow is started, and the preliminary ejection operations for cyan, magenta, and yellow are simultaneously performed (S45). At this time, since it is the nozzle group filled with cyan, magenta, and yellow, that is, all the nozzles, that performs the ejection operation, the predetermined drive frequency f ₃ (kH
In z), preliminary ejection of cyan, magenta, and yellow is performed. In this way, preliminary ejection operations for cyan, magenta, and yellow are performed, and it is determined whether or not the number of preliminary ejections of yellow has reached the set number Ny (S46). When the number of times of preliminary ejection of yellow reaches the set number of times Ny, the preliminary ejection operations of cyan, magenta, and yellow are simultaneously completed (S47).

Here, for example, when all the nozzles are equally divided into three and cyan, magenta and yellow are respectively assigned, f ₁ (kHz) = 3 × f ₃ (kH
z) and f ₂ (kHz) = 3/2 × f ₃ (kHz).

As described above, the preliminary ejection operations of the inks of a plurality of colors are performed at different ejection times according to the inks, and the ejection operations of the three colors are completed at the same time. It is possible to prevent the color inks from being mixed, and it is possible to recover the clogging of the nozzles without performing unnecessary preliminary ejection with the ink that is hard to dry.

Further, the preliminary ejection operation can be performed at a high speed by changing the driving frequency for the preliminary ejection of cyan, the preliminary ejection of cyan and magenta, and the preliminary ejection of cyan, magenta, and yellow.

[0116]

According to the first embodiment, various head preliminary ejection pattern data are stored in the program ROM 6 in advance, the optimum head preliminary ejection pattern is selected according to the head state, and the selected head preliminary ejection pattern is selected. Since the data is transferred to the image RAM 11 and the preliminary ejection of the head can be performed like a normal printing operation, even when another preliminary ejection pattern is required, only the preliminary ejection pattern data of the program ROM 6 is changed. Therefore, the head can be preliminarily ejected with any preliminary ejection pattern.

By having the first and second storage means for storing the head preliminary ejection data inside the head control section, the processing load on the CPU 3 can be reduced,
The system can be speeded up.

Further, by changing the storage data of the first storage means, it is possible to generate any head preliminary ejection pattern, and further, the head preliminary drive can be efficiently performed with the optimum preliminary ejection pattern according to the head state. It can be performed. According to the second embodiment, the head controller has the first and second selecting means and the preliminary ejection data storage control section corresponding to the maximum number of nozzles, so that the preliminary ejection from the ejection data storage control section is performed. Since the print data can be stored in the memory even during the head pre-driving by the data, the throughput of the printer system can be improved.

Further, a mode in which the print data is stored during the printing operation, the non-printing nozzles are detected, and only the non-printing nozzles are driven during the preliminary ejection operation is added. It has become possible to reduce the amount of ink.

According to the third embodiment, when the heads of the head cartridge in which one head chip is filled with the inks of a plurality of colors are preliminarily driven, the number of preliminary ejections of the inks of a plurality of colors can be independently set. It has become possible to suppress wasteful consumption of ink due to pre-driving.

Further, according to the fourth embodiment, when the recording head is preliminarily driven, the number of preliminary ejection operations for each ink is changed, and the preliminary ejection operations for each ink are simultaneously terminated. In addition, it is possible to prevent unnecessary ejection of ink that is difficult to dry and minimize ink consumption in the clogging recovery operation. Further, it is possible to prevent ink color mixing that occurs in preliminary ejection operations of a plurality of colors of ink. Further, the preliminary ejection can be performed at high speed by changing the control means for the preliminary ejection depending on the nozzle group that performs the preliminary ejection.

[Brief description of drawings]

FIG. 1 is a system configuration diagram showing an embodiment of an inkjet recording apparatus according to the present invention.

FIG. 2 is a schematic diagram around a carriage in an embodiment of an inkjet recording apparatus according to the present invention.

FIG. 3 is a configuration diagram showing an example of a head control unit of the inkjet recording apparatus according to the present invention.

FIG. 4 is a configuration diagram showing an example of an internal circuit of a head of the inkjet recording apparatus according to the present invention.

FIG. 5 is a drive timing chart of nozzle groups during image printing in the head of the inkjet recording apparatus according to the present invention.

FIG. 6 is a diagram showing an example of a discharge pattern at the time of preliminary discharge in the head of the inkjet recording apparatus according to the present invention.

FIG. 7 is a flow chart of preliminary ejection control of the head of the inkjet recording apparatus according to the present invention.

FIG. 8 is a configuration diagram showing a second example of the head controller of the inkjet recording apparatus of the present invention.

FIG. 9 is a drive timing chart of nozzle groups during preliminary ejection in the head of the inkjet recording apparatus of the present invention.

FIG. 10 is a flow chart of preliminary drive control of the head of the inkjet recording apparatus of the present invention.

FIG. 11 is a control flow diagram (1/2) when an image is printed by the head of the inkjet recording apparatus of the present invention.

FIG. 12 is a control flow diagram (2/2) at the time of image printing of the head of the inkjet recording apparatus of the present invention.

FIG. 13 is a block diagram of a head drive block of the inkjet recording apparatus of the present invention and a preliminary drive timing diagram of each block group.

FIG. 14 is a flowchart of a preliminary ejection operation according to the fourth embodiment of the present invention.

[Explanation of symbols]

1 inkjet recording device, 2 host computer, 3 CPU, 4 work RAM, 5 font ROM, 6 program ROM, 7 EEPRO
M, 8 interface, 9 operation panel, 1
0 memory control unit, 11 image RAM, 12
Head control unit, 13 recording head, 14 motor control unit, 15 motor, 16 I / O control unit, 1
7 sensors, 18 common bus, 21 recording head unit, 22 carriage, 23 recording medium, 24
Transport roller, 25 cap mechanism,
31 Adjacent Nozzle Group Print Cycle Storage Means, 32 Adjacent Nozzle Group Print Cycle Setting Counter, 33 Print Timing Control Section, 34 Print Drive Pulse Generation Section, 35 Print Dot Number Counter Control Section, 36 Print Drive Pulse Width Setting Counter, 37 Print Drive Pulse width set value storage means,
38 print data processing section, 39 parallel-serial converter, 40 second selection means, 41 preliminary ejection data storage control section, 42 first selection means, 50
4-bit shift register, 51 4-bit latch,
52 32-bit shift register.

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location B41J 3/04 104 F

Claims (16)

[Claims] 1. An inkjet head having a plurality of nozzles arranged in a line is mounted on a carriage that moves relative to a recording medium, and ink is ejected from the nozzle group to perform one-line print recording in the nozzle array direction. In an inkjet recording apparatus, first storage means for storing a plurality of preliminary ejection data for preliminarily driving a head, and specific preliminary ejection pattern data selected from the plurality of preliminary ejection data are stored. An inkjet recording apparatus comprising a second storage unit. 2. The second storage means stores the preliminary ejection pattern data when the ink jet recording apparatus performs the preliminary drive operation of the head, and stores the print data when the ink jet recording apparatus performs the printing operation. The inkjet recording device described. 3. An ink jet head having a plurality of nozzles arranged in a line is mounted on a carriage that moves relative to a recording medium, and each of the plurality of nozzles is divided into several nozzles to form a plurality of nozzle groups. Then, in an inkjet recording apparatus that sequentially drives each nozzle group by delaying for a predetermined time and drives them simultaneously to eject ink from the nozzle groups to perform one-line print recording in the nozzle array direction, based on input image data. Preliminary ejection data storage control means for generating and storing preliminary ejection data for preliminarily driving the head, and print data for image recording or preliminary ejection data from the preliminary ejection data storage control means is selected and output. And a second selection unit for selecting and outputting input image data or a head nozzle ejection data pattern.
A first selection for selecting either preparatory ejection data for preliminarily driving the head or print data for image recording as drive data for driving the nozzles of the inkjet head. An inkjet recording apparatus, wherein the inkjet recording apparatus is supplied to the inkjet head through a means. 4. The ink jet recording apparatus according to claim 3, wherein the preliminary ejection data storage control means can arbitrarily set preliminary ejection data. 5. The ink jet recording apparatus according to claim 4, wherein the preliminary ejection data stored in the preliminary ejection data storage control means is provided for at least the number of divided simultaneous driving of nozzles. 6. The preliminary ejection data, after passing through a second selecting means for selecting and outputting either the preliminary ejection data prepared in advance or the print data for image recording,
6. The preliminary ejection data storage control means stores the data.
The inkjet recording device described. 7. The second selection means is controlled so as to select print data for image recording during a normal printing operation and select preliminary ejection data before or after the start of printing. Inkjet recording means described. 8. A predetermined period during normal printing operation when the second selecting means selects print data for image recording and stores the print data for image recording in the preliminary ejection data storage control means. A storage operation is continuously performed within the nozzles to detect nozzles that have never been printed and nozzles that have been printed at least once within the printing operation period, and to convert the data of the nozzles that are not printed into data to be printed, 8. The pre-ejection data storage control means stores the printed data of the nozzle portion into data that does not print and stores the converted data.
Inkjet recording means described. 9. An inkjet head, wherein an inkjet head having a plurality of nozzles arranged in a line is mounted on a carriage that moves relative to a recording medium, and ink is ejected from the nozzles to perform one-line print recording in the nozzle array direction. In the recording device, divide all nozzles into multiple nozzle groups,
An inkjet recording apparatus comprising: a control unit that controls so as to preliminarily eject ink for each of the divided nozzle groups. 10. A plurality of divided nozzle groups, in the process of driving the nozzles by head pre-driving,
The inkjet recording apparatus according to claim 9, wherein at least one or more nozzle groups are selected and driven. 11. The ink jet recording apparatus according to claim 9, wherein the ink jet head mounted on the ink jet recording apparatus is a head filled with ink of a plurality of different colors for each of a plurality of divided nozzle groups. 12. The ink jet recording apparatus according to claim 11, wherein there are at least two kinds of inks of a plurality of colors which are different in the ink jet head mounted in the ink jet recording apparatus. 13. The ink jet recording apparatus according to claim 11 or 12, wherein a head chip of an ink jet head mounted in the ink jet recording apparatus is configured in a single unit. 14. An ink jet for performing color printing recording by using a recording head in which all the nozzles arranged in a row are divided into a plurality of nozzle groups and the divided nozzle groups are filled with inks of different colors. A preliminary ejection method for an inkjet recording apparatus, characterized in that the preliminary ejection method for the recording apparatus performs preliminary drive by changing the number of preliminary ejection operations for each ink. 15. The preliminary ejection method for an ink jet recording apparatus according to claim 14, wherein the preliminary ejection operations of the respective inks are sequentially started so as to end simultaneously. 16. The preliminary ejection method for an ink jet recording apparatus according to claim 15, wherein the drive frequency for the preliminary ejection is determined according to the number of nozzle groups that perform the ejection operation.