JP2002067320A - Ink-jet recording method and ink-jet recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize high quality and high-speed printing by reducing an impact which an airflow generated by liquid drop groups in a immediately preceding event has on a liquid drop group in a subsequent event, when all discharges executed in a recording head during a driving cycle at discharge openings is defined as an event, in a constitution that a plurality of discharge openings of the recording head drives with time-sharing and discharges ink. SOLUTION: An area A1 projected to a virtual prescribed plane yz, formed while all liquid drop groups are flying, is 92% to less than 100% of an area A2 found by an expression: A2=(the driving cycle of the discharge openings tr × a discharge speed v × a maximum width of simultaneous discharge liquid drops w). The maximum width of the simultaneous discharge liquid drops w is a distance obtained by projecting to the prescribed plane a distance between liquid drops of both ends out of liquid drop groups belonging to a simultaneously driving block of the time-sharing driving.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an ink jet recording method and an ink jet recording apparatus, and more particularly to a method for reducing white stripes which may occur at a joint between each scan of a recording head.

[0002]

2. Description of the Related Art Conventionally, an ink jet recording apparatus has been used as a recording apparatus such as a printer or a facsimile machine because of its low noise, low running cost, easy downsizing and colorization of the apparatus. Widely used.

[0003] One trend of such widely used ink jet recording apparatuses is to increase the density of ink discharge ports (hereinafter also referred to as nozzles) and to reduce the size of ink droplets in order to print higher quality images. Droplet formation is in progress. Also,
At the same time, high-speed printing is also required, and therefore, the drive frequency and the number of nozzles have been increased.

In particular, in the field of ink jet printers, in recent years, further improvements have been made to achieve image quality comparable to that of photographs.
In general, each color of the ink used is an image almost similar to solid printing, that is, an image having a relatively high duty. In addition, it is important that such a high-quality image is output without taking much time.

[0005]

SUMMARY OF THE INVENTION The present inventor has been studying a recording head and an apparatus configuration for photographic image quality and high-speed operation in order to follow the flow of high image quality and the like in the ink jet printer described above. Then, the following technical issues were recognized.

That is, when the number of droplets simultaneously ejected from the nozzles of the recording head is increased to about 128 or more with respect to the ejection of small droplets as small as about 4.5 ng or less,
A phenomenon occurs in which the landing position of the droplet ejected from the nozzle at the outermost position of the nozzle array shifts to the side where the nozzles are arranged in the arrangement direction, that is, inward (hereinafter, also referred to as an end portion). For example, when solid printing is performed, there is a problem that a white stripe may be generated at a joint which is a boundary of an area recorded in each scan (hereinafter, also referred to as a band).

FIG. 22 is a diagram for explaining the occurrence of the white stripe. FIG. 3 shows a case where the recording head performs reciprocating scanning, and recording is performed on band 1 and band 2 during that time. Between the forward scanning and the backward scanning, the paper is fed by the nozzle array width of the recording head. Thus, in the forward scan, the nozzle at the lower end of the nozzle array of the recording head is adjacent to the boundary between band 1 and band 2, while in the backward scan, the nozzle at the upper end is adjacent to the boundary.

As shown in FIG. 1, the ink dots ejected from the nozzles at the respective ends land inward from the original positions where they should land, and as a result, the boundary between band 1 and band 2 There is a blank space at the joint where
This is recognized as a white stripe. In addition to the case where the paper is fed by the full width of the nozzle array of the print head as in the example shown in FIG. 22, the so-called multi-pass printing in which each dot row formed in the scanning direction is printed by a plurality of different nozzles. The same phenomenon can be observed even when the paper feed amount is smaller than the full width as described above.

The inward displacement of the ink droplets ejected from the end nozzles is followed by an air flow generated by ejection (hereinafter, referred to as an event) due to driving during one period of the nozzle driving cycle in the recording head. The inventor of the present application speculates that this is caused by affecting the ejection droplet of the event.

The present invention has been made based on the above-described recognition or inference, and it is an object of the present invention to provide a method in which an airflow generated by a droplet group caused by an event immediately before ink ejection is caused by a flying droplet group of a subsequent event. It is an object of the present invention to provide an ink jet recording method and an ink jet recording method capable of realizing high image quality and high speed printing while reducing the influence on the ink jet recording.

[0011]

According to the present invention, there is provided:
A recording head having 128 or more ejection ports arranged in a line for ejecting ink at an array density of 600 dpi or more is used, and the plurality of ejection ports of the recording head are driven in a time-division manner to print the recording medium from the plurality of ejection ports. In the inkjet recording method in which ink is ejected to perform printing, when the ejection direction of the ink is the z direction in the orthogonal coordinate system and the scanning direction of the recording head is the x direction, one cycle of the driving cycle for one ejection port In the meantime, the ink droplets distributed in the area between the recording head and the recording medium are projected on the yz plane by ejecting from the 128 or more ejection ports corresponding to the one row in the recording head. The area Al of the virtual area obtained by connecting the centers of the ink drops located at the outermost position of the ink drop group with a straight line is represented by A2 = Driving cycle on the serial one of the discharge port
(tr) × ejection speed (v) × maximum width (w) of ink droplets ejected by simultaneous driving in the time-division driving, where
The maximum width of the ink droplets ejected by the simultaneous driving in the time-division driving is a distance obtained by projecting the distance between the ink droplets at both ends of the ink droplet group belonging to the ejection by the simultaneous driving onto the yz plane. Area A2 determined from
Is not less than 92% and less than 100%.

Further, a recording head having 128 or more ejection ports arranged in a line for ejecting ink at an arrangement density of 600 dpi or more is used, and the plurality of ejection ports of the recording head are driven in a time-division manner. In an ink jet recording apparatus that performs recording by discharging ink from a discharge port to a recording medium, when the discharge direction of the ink is the z direction in a rectangular coordinate system and the scan direction of the print head is the x direction,
During one cycle of the driving cycle for one ejection port, the ejection is performed from the 128 or more ejection ports corresponding to the one row in the recording head, so that the ejection is distributed in an area between the recording head and the recording medium. Is a virtual area obtained by projecting an ink droplet group on the yz plane, and the area Al of the area formed by connecting the center of the ink droplet located at the outermost position of the ink droplet group with a straight line is A2 = Drive cycle (tr) for the one ejection port x ejection speed (v) x maximum width (w) of ink droplets ejected by simultaneous drive in the time-division drive, where simultaneous drive in the time-division drive The maximum width of the ink droplet to be ejected is defined as 9 of the area A2 obtained from the distance obtained by projecting the distance between the ink droplets at both ends of the ink droplet group belonging to the ejection by the simultaneous driving onto the yz plane. It is characterized by being at least 2% and less than 100%.

According to the above arrangement, when the ratio of the area A1 to the area A2 is not less than 92% and less than 100%, the ratio of the area A1 in the recording head during the driving cycle of the ejection port is reduced.
The ink droplet groups ejected from the plurality of orifices are distributed in a substantially rectangular area, and are close to the ink droplet groups ejected during one driving cycle in the following manner.
Thus, it is possible to reduce the occurrence of an airflow in which the ink drop group in the previous cycle affects the ink drop group in the next cycle.

[0014]

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

In the embodiment described below, a printer will be described as an example of a recording apparatus using an ink jet recording method. Prior to describing a specific example of the effect of airflow due to an event immediately before ink ejection to which the present invention is applied, a configuration of an ink jet printer that executes the event will be described with reference to FIGS. .

In this specification, "print"
(Sometimes referred to as "records") refers not only to the formation of significant information such as characters and figures,
In addition, regardless of whether or not they are visualized so that humans can perceive them visually, images, patterns,
This also refers to the case where a pattern or the like is formed or the medium is processed.

Here, the term "print medium" or "recording sheet" means not only paper used in a general printing apparatus but also cloth, plastic film, metal plate, glass, ceramics, wood, and leather. The term "recording medium" will be used to refer to an ink-acceptable material.
Or simply "paper".

Further, "ink" (sometimes referred to as "liquid") is to be interpreted widely as in the definition of "print" described above. It refers to a liquid that can be used for forming a pattern or the like, processing a print medium, or processing ink (for example, solidifying or insolubilizing a color material in ink applied to a print medium).

1. 1 and 2 show a schematic configuration of a printer using an ink jet recording system. In FIG. 1, the outer shell of an apparatus main body M1000 of the printer in this embodiment includes a lower case M1001, an upper case M1002, and an access cover M1.
003 and an exterior member including a discharge tray M1004, and a chassis M3019 (see FIG. 2) housed in the exterior member.

The chassis M3019 is composed of a plurality of plate-like metal members having a predetermined rigidity, forms a skeleton of a recording apparatus, and holds each recording operation mechanism described later. Further, the lower case M1001 is connected to the apparatus main body M1.
000, and the upper case M1002 forms the upper half of the exterior of the apparatus main body M1000. A combination of the two cases has a hollow space having a storage space for storing each mechanism described below. It has a body structure. Openings are formed in the upper surface and the front surface of the apparatus main body M1000, respectively.

Further, one end of the discharge tray M1004 is rotatably held by the lower case M1001, and the opening formed on the front surface of the lower case M1001 can be opened and closed by the rotation. For this reason, when performing the recording operation, the discharge tray M100
By rotating the opening 4 to the front side to open the opening, the recording sheets can be discharged from here, and the discharged recording sheets P can be sequentially stacked.
Also, the paper discharge tray M1004 has two auxiliary trays M.
1004a and M1004b are accommodated, and the tray support area can be expanded or reduced in three stages by pulling out each tray as needed.

One end of the access cover M1003 is rotatably held by the upper case M1002 so that an opening formed on the upper surface can be opened and closed. When the access cover M1003 is opened, the inside of the main body is opened. The stored recording head cartridge H1000 or ink tank H1900 can be replaced. Although not particularly shown here, the access cover M10
When the cover 03 is opened and closed, a projection formed on the back surface rotates the cover opening / closing lever, and the open / closed state of the access cover can be detected by detecting the rotation position of the lever with a microswitch or the like. It has become.

On the rear upper surface of the upper case M1002, a power key E0018 and a resume key E0019 are provided.
Is provided so as to be pressed, and an LED E0020 is provided. When the power key E0018 is pressed, L
The ED E0020 lights up to notify the operator that recording is possible. LED E0
Reference numeral 020 has various display functions such as changing the blinking method and color, and notifying an operator of a printer trouble or the like. Further, the buzzer E0021 (FIG. 7) can be smoothed. When the trouble or the like is solved, the recording is restarted by pressing the resume key E0019.

2. Printing Operation Mechanism Next, the printing operation mechanism according to the present embodiment, which is stored and held in the apparatus main body M1000 of the printer, will be described.

The recording operation mechanism in this embodiment includes an automatic feeding unit M3022 for automatically feeding the recording sheet P into the apparatus main body, and a recording sheet P sent one by one from the automatic feeding unit. A conveyance section M3029 for guiding the recording sheet P from the recording position to the discharge section M3030 while guiding the recording sheet P to a predetermined recording position; and a recording sheet P conveyed to the recording position.
And a recovery unit (M5000) for performing recovery processing on the recording unit and the like.

Here, the recording section will be described. The recording section includes a carriage M4001 movably supported by a carriage shaft M4021, and a carriage M4001.
The recording head cartridge H1000 is detachably mounted on the recording head cartridge 4001.

2.1 Recording Head Cartridge First, the recording head cartridge used in the recording section will be described with reference to FIGS.

As shown in FIG. 3, the recording head cartridge H1000 in this embodiment includes an ink tank H1900 for storing ink and an ink tank H190 for storing the ink.
And a recording head H1001 that ejects ink supplied from nozzles from nozzles according to recording information. The recording head H1001 employs a so-called cartridge system which is removably mounted on a carriage M4001 described later.

The recording head cartridge H10 shown here
In FIG. 00, in order to enable photographic high-quality color recording, for example, ink tanks H1900 independent of each color of black, light cyan, light magenta, cyan, magenta and yellow are prepared as ink tanks. As shown in the figure, each is detachable from the recording head H1001.

As shown in an exploded perspective view of FIG. 5, the recording head H1001 includes a recording element substrate H1100, a first plate H1200, an electric wiring substrate H1300, a second plate H1400, a tank holder H1500,
It is composed of a flow path forming member H1600, a filter H1700, and a seal rubber H1800.

On the printing element substrate H1100, a plurality of printing elements for ejecting ink to one side of the Si substrate and electric wiring of Al or the like for supplying power to each printing element are formed by a film forming technique. A plurality of ink flow paths and a plurality of ejection ports H1100T corresponding to the recording elements are formed by photolithography, and an ink supply port for supplying ink to the plurality of ink flow paths is formed to open on the back surface. Have been. The printing element substrate H1100 is bonded and fixed to a first plate H1200, and an ink supply port H1201 for supplying ink to the printing element substrate H1100 is formed here. Further, a second plate H1400 having an opening is adhered and fixed to the first plate H1200, and the electric wiring board H13 is connected via the second plate H1400.
00 is held so as to be electrically connected to the printing element substrate H1100. This electric wiring board H1300
Is for applying an electric signal for discharging ink to the recording element substrate H1100.
0 and an external signal input terminal H located at an end of the electric wiring for receiving an electric signal from the main body.
1301 and an external signal input terminal H1301
Are positioned and fixed on the back side of a tank holder H1500 described later.

On the other hand, a flow path forming member H1600 is fixed to the tank holder H1500 for detachably holding the ink tank H1900, for example, by ultrasonic welding, and an ink flow path H1501 extending from the ink tank H1900 to the first plate H1200. Is formed. Further, a filter H1700 is provided at an end portion of the ink flow path H1501 on the ink tank side which engages with the ink tank H1900, so that intrusion of dust from the outside can be prevented. In addition, a seal rubber H1800 is attached to an engagement portion with the ink tank H1900, so that evaporation of ink from the engagement portion can be prevented.

Further, as described above, the tank holder H1
500, flow path forming member H1600, filter H170
And a tank element comprising a recording element substrate H1100, a first plate H1200, an electric wiring substrate H1300, and a second plate H1400, which are joined together by bonding or the like. This constitutes the recording head H1001.

2.2 Carriage Next, referring to FIG. 2, the recording head cartridge H100 will be described.
The carriage M4001 on which the “0” is mounted will be described.

As shown in FIG. 2, the carriage M4001
Has a recording head H10 that engages with the carriage M4001.
01, a carriage cover M4002 for guiding the recording head H1001 to a predetermined mounting position on the carriage M4001, a head set lever M4007 that engages with the tank holder H1500 of the recording head H1001 and presses the recording head H1001 to the predetermined mounting position. Is provided. That is, the head set lever M4007 is provided above the carriage M4001 so as to be rotatable with respect to the head set lever shaft, and a spring-biased head set plate (not shown) is provided at an engagement portion with the recording head H1001. The recording head H1001 is mounted on the carriage M4001 while being pressed by the spring force.

Further, a contact flexible print cable (refer to FIG. 7, hereinafter referred to as a contact FPC) is provided on another engagement portion of the carriage M4001 with the recording head H1001.
E0011 is provided, and the contact FPC E
0011 and a contact portion (external signal input terminal) H1301 provided on the print head H1001
Are electrically in contact with each other, so that various kinds of information for recording and reception and supply of electric power to the recording head H1001 can be performed.

Here, an elastic member such as rubber (not shown) is provided between the contact portion of the contact FPC E0011 and the carriage M4001, and the contact portion is formed by the elastic force of the elastic member and the pressing force of the headset lever spring. The secure contact with the carriage M4001 is enabled. Further, the contact FPC
E0011 is connected to a carriage substrate E0013 mounted on the back of the carriage M4001 (see FIG. 7).

3. Scanner A printer according to this embodiment includes a carriage M400 instead of the printhead cartridge H1000 described above.
1 can be used as a reading device by attaching a scanner.

The scanner moves in the main scanning direction together with the carriage M4001 on the printer side, and reads a document image fed instead of a recording medium in the course of movement in the main scanning direction. By alternately performing the reading operation in the main scanning direction and the feeding operation of the document in the sub-scanning direction, one document image information can be read.

FIGS. 6A and 6B show a scanner M6 for explaining a schematic configuration of the scanner M6000.
000 is shown upside down.

As shown, the scanner holder M6001
Has a substantially box-like shape, and contains therein an optical system and a processing circuit necessary for reading. When the scanner M6000 is mounted on the carriage M4001, a reading unit lens M60 is provided at a portion facing the original surface.
The lens M6006 converges the reflected light from the document surface to an internal reading unit to read the document image. On the other hand, the illumination unit lens M6005 has a light source (not shown) inside, and light emitted from the light source is applied to the document via the lens M6005.

The scanner cover M6003 fixed to the bottom of the scanner holder M6001 is attached to the scanner holder M6.
The inside of 001 is fitted so as to shield light, and the operability of attaching and detaching to and from the carriage M4001 is improved by louver-shaped grips provided on the side surface. Scanner holder M60
01 has substantially the same outer shape as the recording head H1001, and can be attached to and detached from the carriage M4001 by the same operation as the recording head cartridge H1000.

The scanner holder M6001 houses a substrate having a read processing circuit, and a scanner contact PCB connected to the substrate is provided so as to be exposed to the outside. The scanner M6000 is mounted on the carriage M4001. Scanner contact PC when attached
B M6004 contacts the contact FPC E0011 on the carriage M4001 side, and the substrate is moved to the carriage M4.
001 is electrically connected to a control system on the main body side.

4. Configuration of Electric Circuit of Printer Next, an electric circuit configuration in the embodiment of the present invention will be described. FIG. 7 is a diagram schematically showing an example of the overall configuration of an electric circuit according to this embodiment.

The electric circuit in this embodiment mainly includes a carriage board (CRPCB) E0013 and a main PC.
B (Printed Circuit Board) E0014, power supply unit E0015 and the like. Here, the power supply unit E0015 is connected to the main PCB E0014 and supplies various drive powers. In addition, the carriage substrate E0013 includes a carriage M400.
1 (FIG. 2).
In addition to functioning as an interface for transmitting and receiving signals to and from the recording head through the contact FPC E0011,
Based on a pulse signal output from the encoder sensor E0004 in accordance with the movement of the carriage M4001, the encoder scale E0005 and the encoder sensor E0004
And outputs the output signal to the main PCB E0014 through the flexible flat cable (CRFFC) E0012.

Further, a main PCB E0014 is a printed circuit board unit for controlling the driving of each part of the ink jet recording apparatus in this embodiment, and includes a paper edge detection sensor (PE sensor) E0007 and an ASF (automatic paper feeder).
Sensor E0009, cover sensor E0022, parallel interface (parallel I / F) E0016, serial interface (serial I / F) E0017,
An I / O port for the resume key E0019, LED E0020, power key E0018, buzzer E0021, etc. is provided on the board. Furthermore, the carriage M14
A motor (CR motor) E0001 serving as a drive source for main scanning of 00, a motor (LF motor) E0002 serving as a drive source for transporting a print medium, and a print head rotating operation and a print medium feeding operation. Motor (PG
In addition to being connected to a motor E0003 to control these drives, an ink empty sensor E0006, a GAP sensor E0008, a PG sensor E0010, a CRFFC E
0012, a connection interface with the power supply unit E0015.

FIGS. 8A and 8B show the main PCB.
It is a block diagram which shows the internal structure of E0014. In the figure, E1001 is a CPU, and this CPU E1
Reference numeral 001 includes a clock generator (CG) E1002 internally connected to the oscillation circuit E1005, and generates a system clock by an output signal E1019. Further, the ROM E1004 and the ASIC (Application Specific Integrated Circuit) are connected via the control bus E1014.
uit) connected to E1006 and controlled by ASIC E1006, input signal E1017 from the power key, input signal E1016 from the resume key, cover detection signal E1042,
The state of the head detection signal (HSENS) E1013 is detected, and the buzzer E0021 is driven by the buzzer signal (BUZ) E1018. While detecting the state of the temperature detection signal (TH) E1012, various other logical operations and condition judgments are performed to control the driving of the ink jet printing apparatus.

Here, the head detection signal E1013 is transmitted from the print head cartridge H1000 to the flexible flat cable E0012, the carriage board E0013, and the contact flexible print cable E0011.
, An ink empty detection signal E1011 is an analog signal output from the ink empty sensor E0006, and a temperature detection signal E1012 is output from a thermistor (not shown) provided on the carriage substrate E0013. Is an analog signal.

E1008 is a CR motor driver which uses a motor power supply (VM) E1040 as a drive source and
CR motor control signal E1036 from IC E1006
Generates a CR motor drive signal E1037 according to
The R motor E0001 is driven. E1009 is LF / P
A G motor driver that uses a motor power supply E1040 as a drive source, generates an LF motor drive signal E1035 according to a pulse motor control signal (PM control signal) E1033 from the ASIC E1006, and thereby drives the LF motor and the PG motor A drive signal E1034 is generated to drive the PG motor.

E1010 is a power supply control circuit,
In accordance with a power control signal E1024 from CE1006, power supply to each sensor having a light emitting element is controlled.
Parallel I / F E0016 is ASIC E1006
I / F signal E1030 is transmitted to an externally connected parallel I / F cable E1031, and the signal of the parallel I / F cable E1031 is transmitted to an ASIC.
It transmits to E1006. Serial I / F E0017
Is the serial I / F signal E from the ASIC E1006.
1028 is transmitted to the serial I / F cable E1029 connected to the outside, and the signal from the cable E1029 is transmitted to the ASIC E1006.

On the other hand, from the power supply unit E0015, the head power supply (VH) E1039 and the motor power supply (VM) E
1040, a logic power supply (VDD) E1041 is supplied. Also, the head power supply O from the ASIC E1006
An N signal (VHON) E1022 and a motor power supply ON signal (VMOM) E1023 are input to the power supply unit E0015, and control ON / OFF of the head power supply E1039 and the motor power supply E1040, respectively. Power supply unit E
Logic power supply (VDD) E10 supplied from 0015
41 is a main PC after voltage conversion as necessary.
It is supplied to each part inside and outside BE0014.

The head power signal E1039 is sent to the flexible flat cable E0011 after being smoothed on the main PCB E0014, and is used for driving the recording head cartridge H1000. E100
Reference numeral 7 denotes a reset circuit which detects a drop in the logic power supply voltage E1041 and detects the CPU E1001 and the ASIC E1.
A reset signal (RESET) E1015 is supplied to 006 to perform initialization.

The ASIC E1006 is a one-chip semiconductor integrated circuit.
It is controlled by the U E1001 and outputs the aforementioned CR motor control signal E1036, PM control signal E1033, power supply control signal E1024, head power supply ON signal E1022, motor power supply ON signal E1023, and the like. F E0017
, A PE detection signal (PES) E1025 from the PE sensor E0007, an ASF sensor E
ASF detection signal (ASFS) E102 from 0009
6. The state of the GAP detection signal (GAPS) E1027 from the sensor (GAP) sensor E0008 for detecting the gap between the recording head and the recording medium and the PG detection signal (PGS) E1032 from the PG sensor E0010 are detected. Data indicating the state is transmitted to the CPU E1001 via the control bus E1014, and based on the input data, the CPU E1001 controls the driving of the LED driving signal E1038 to blink the LEDE0020.

Further, an encoder signal (ENC) E10
20 is detected to generate a timing signal, and the printhead cartridge H100 is generated by the head control signal E1021.
The interface with 0 controls the recording operation. Here, the encoder signal (ENC) E1020 is an output signal of the CR encoder sensor E0004 input through the flexible flat cable E0012. The head control signal E1021 is transmitted to the flexible flat cable E0012 and the carriage board E001.
3 and a contact FPC E0011 to the print head H1000.

FIGS. 9A and 9B show ASIC E
FIG. 2 is a block diagram showing an example of the internal configuration of the unit 1006.

In the figure, the connection between the blocks shows only the flow of data related to the control of the head and the mechanical components of each part, such as print data and motor control data. Control signals and clocks related to reading and writing of the data, control signals related to DMA control, and the like are omitted to avoid complication in the drawings.

Referring to FIG. 9, reference numeral E2002 denotes a PLL controller. As shown in FIG. 9, an ASIC E1 is controlled by a clock signal (CLK) E2031 and a PLL control signal (PLLON) E2033 output from the CPU E1001.
Clock supplied to most of 006 (not shown)
Occurs.

E2001 is a CPU interface (CPU I / F), and a reset signal E1015,
Soft reset signal (PDWN) E2032 and clock signal (CLK) E2 output from CPU E1001
031 and a control signal from the control bus E1014,
Control of register read / write for each block as described below, supply of a clock to some blocks, acceptance of an interrupt signal, etc. (all not shown) are performed, and an interrupt signal (IN) is sent to the CPU E1001.
T) Output E2034 to notify the occurrence of an interrupt in ASIC E1006.

Reference numeral E2005 denotes a DRAM, which includes a reception buffer E2010 and a reception buffer E2010 as data buffers for recording.
Work buffer E2011, print buffer E201
4. It has various areas such as a data buffer E2016 for development and a motor control buffer E for motor control.
2023, and as a buffer used in the scanner operation mode, a scanner capture buffer E2024, a scanner data buffer E2026, and a transmission buffer E20 used in place of the recording data buffers described above.
28.

The DRAM E2005 has a CP
It is also used as a work area necessary for the operation of the EU 1001. That is, E2004 is a DRAM control unit, which is provided from the CPU E1001 by the control bus to the DRAM control unit.
Access to E2005 and DMA control unit E described later
Switching from access to the DRAM E2005 from 2003 is performed to perform a read / write operation to the DRAM E2005.

The DMA controller E2003 receives a request (not shown) from each block, and receives an address signal, a control signal (not shown), and write data E2038, E2041, E2044, and E2 in the case of a write operation.
053, E2055, E2057 and the like are output to the DRAM control unit E2004 to perform DRAM access. In the case of reading, read data E2040, E2043, E2045,
E2051, E2054, E2056, E2058, E
2059 is passed to the requesting block.

E2006 is based on IEEE1284I
/ F, CPU via CPU I / FE 2001
The parallel I / F E001 is controlled by the control of E1001.
6, a bidirectional communication interface with an external host device (not shown) is provided, and a parallel I / O
Received data from the F E0016 (PIF received data E
2036) by the DMA processing.
To the scanner, and when reading the scanner, the DRAM E2
The data (IEEE1284 transmission data (RDPIF) E205)
9) is transmitted to the parallel I / F by the DMA processing.

E2007 is a universal serial bus (USB) I / F. The serial I / F is controlled by the CPU E1001 via the CPU I / F E2001.
In addition to performing a two-way communication interface with an external host device (not shown) through the FE0017, the reception control unit E (USB reception data E2037) from the serial I / FE 0017 is subjected to DMA processing during printing during printing.
Delivered to 2008, DRAM when scanning
Data (USB transmission data (RDUSB) E2058) stored in the transmission buffer E2028 in E2005
Is transmitted to the serial I / F E0017 by the DMA processing. The reception control unit E2008 has a 1284 I / F E2
006 or received data (WDIF) E203 from the selected I / F of the USB I / F E2007
8) is written to the reception buffer write address managed by the reception buffer control unit E2039. E2009 is a compression / decompression DMA controller, which is a CPU I / F E2
Under the control of the CPU E1001 via 001, the reception data (raster data) stored in the reception buffer E2010 is read from the reception buffer read address managed by the reception buffer control unit E2039, and the data (RDWK) E2040 is designated. The data is compressed and decompressed according to the mode, and written in the work buffer area as a recording code string (WDWK) E2041.

Reference numeral E2013 denotes a recording buffer transfer DMA controller, which is a CPU controller via the CPU I / FE 2001.
Work buffer E2011 under the control of E1007
The upper recording code (RDWP) E2043 is read out, and each recording code is stored in a print buffer E20 suitable for the data transfer order to the recording head cartridge H1000.
14 (WDWP E20)
44). Reference numeral E2012 denotes a work clear DMA controller, which controls the recording buffer transfer D under the control of the CPU E1001 via the CPU I / F E2001.
The designated work fill data (WDWF) E2042 is repeatedly written into the area on the work buffer to which the transfer by the MA controller E2013 has been completed.

Reference numeral E2015 denotes a print data expansion DMA controller, which controls the CP via the CPU I / F E2001.
The head control unit E2018 is controlled by the control of U E1001.
Triggered by the data development timing signal E2050 from the CPU, the recording code rearranged and written on the print buffer and the development data written on the development data buffer E2016 are read, and the development record data (RDH) is read.
DG) E2045 is stored in column buffer write data (WD
HDG) Write to the column buffer E2017 as E2047. Here, the column buffer E2017 is an SRAM for temporarily storing transfer data (developed recording data) to the recording head cartridge H1000, and includes a recording data developing DMA controller E2015 and a head controller E2015.
Shared management is performed by both blocks by a handshake signal (not shown) with 2018.

E2018 denotes a head control unit, which is a CPU I /
Under the control of the CPU E1001 via the FE2001, the recording head cartridge H is controlled via a head control signal.
1000 or the interface with the scanner, and based on the head drive timing signal E2049 from the encoder signal processing unit E2019, the print data development D
Data expansion timing signal E to MA controller
2050 is output.

At the time of printing, in accordance with the head drive timing signal E2049, the developed print data (RDHD) E2048 is read from the column buffer, and the data is output to the print head cartridge H1000 as a head control signal E1021. In the scanner reading mode, the fetched data (WDHD) E2053 input as the head control signal E1021 is converted to the DR.
Scanner capture buffer E202 on AM E2005
4 is DMA-transferred. Reference numeral E2025 denotes a scanner data processing DMA controller, and the CPU I / F E200
Under the control of the CPU E1001 through the CPU 1, the read buffer read data (RDAV) E2054 stored in the scanner capture buffer E2024 is read, and the processed data (WDAV) E20 obtained by performing a process such as averaging.
55 is written to the scanner data buffer E2026 on the DRAM E2005. E2027 is a scanner data compression DMA controller, and the processed data (RDYC) E in the scanner data buffer E2026 is controlled by the CPU E1001 via the CPU I / F E2001.
2056 is read out to perform data compression, and the compressed data (WDYC) E2057 is written and transferred to the transmission buffer E2028.

Reference numeral E2019 denotes an encoder signal processing unit which receives an encoder signal (ENC) and receives a signal from the CPU E1.
In addition to outputting the head drive timing signal E2049 in accordance with the mode determined by the control of 001, information relating to the position and speed of the carriage M4001 obtained from the encoder signal E1020 is stored in a register.
1001. The CPU E1001 determines various parameters in controlling the CR motor E0001 based on this information. E2020 denotes a CR motor control unit, which is a CPU via a CPU I / F E2001.
By the control of E1001, the CR motor control signal E103
6 is output.

Reference numeral E2022 denotes a sensor signal processing unit, which detects signals E1033, E1024, E1024, and E102 output from the PG sensor E0010, the PE sensor E0007, the ASF sensor E0009, the GAP sensor E0008, and the like.
In response to E1027, the sensor information is transmitted to CPUE101 in accordance with the mode determined by the control of CPUE1001.
01 and a sensor detection signal E205 to the LF / PG motor control DMA controller E2021.
2 is output.

The LF / PG motor control DMA controller E2021 is connected to the CPU controller E2021 via the CPU I / F E2001.
The DRAM E2005 is controlled by the PU E1001.
In addition to reading the pulse motor drive table (RDPM) E2051 from the upper motor control buffer E2023 and outputting the pulse motor control signal E1033, depending on the operation mode, the pulse motor control signal E1033 is output using the sensor detection signal as a control trigger. Also, E20
Reference numeral 30 denotes an LED control unit, which is a CPU I / FE 2001
An LED drive signal E1038 is output under the control of the CPU E1001 via the CPU. Further, E2029 is a port control unit, and C20 via CPU I / F E2001.
By controlling the PU E1001, the head power ON signal E
1022, a motor power ON signal E1023, and a power control signal E1024. 5. Next, the operation of the ink jet recording apparatus according to the embodiment of the present invention configured as described above will be described with reference to the flowchart of FIG.

When the apparatus main body 1000 is connected to the AC power supply, first, in step S1, first initialization processing of the apparatus is performed. In this initialization process, the ROM and R
Check the electric circuit system such as AM check,
Electrically confirm that the device can operate normally.

Next, in step S2, the apparatus main body M100
0 power key E001 provided on the upper case M1002.
8 is turned on, and the power key E00
If the button 18 has been pressed, the process moves to the next step S3, where a second initialization process is performed.

In the second initialization processing, various driving mechanisms and the recording head of the apparatus are checked. That is, when the various motors are initialized and the head information is read, it is confirmed whether the apparatus can operate normally.

Next, in step S4, an event is waited. That is, the apparatus monitors command events from the external I / F, panel key events due to user operations, internal control events, and the like, and executes a process corresponding to the event when these events occur.

For example, if a print command event is received from the external I / F in step S4, the process proceeds to step S5, and if a power key event is generated by a user operation in the same step, the process proceeds to step S10. The process proceeds to step S11 when another event occurs in the same step. Here, in step S5, a print command from the external I / F is analyzed, and the designated paper type,
The paper size, print quality, paper feeding method, and the like are determined, data representing the determination result is stored in the RAM E2005 in the apparatus, and the process proceeds to step S6. Next, in step S6, sheet feeding is started by the sheet feeding method designated in step S5, the sheet is fed to a recording start position, and the process proceeds to step S7. In step S7, a recording operation is performed. In this recording operation, the recording data sent from the external I / F is temporarily stored in the recording buffer, and then stored in the CR motor E0001.
To start the movement of the carriage M4001 in the main scanning direction, and supply the print data stored in the print buffer E2014 to the printhead H1001 to print one line, and print one line of print data. When the recording operation is completed, the LF motor E0002 is driven to rotate the LF roller M3001 to feed the paper in the sub-scanning direction. Thereafter, the above operation is repeatedly performed, and when the recording of one page of recording data from the external I / F is completed, the process proceeds to step S8.

In step S8, the LF motor E0002
Is driven to drive the paper discharge roller M2003, and the paper feeding is repeated until it is determined that the paper is completely fed out of the apparatus. When the paper is completely discharged, the paper is completely discharged onto the paper discharge tray M1004a. Becomes

Next, in step S9, it is determined whether or not the recording operation of all pages to be recorded has been completed, and if pages to be recorded remain, the process returns to step S5. The operations from S5 to S9 are repeated,
When the recording operation of all pages to be recorded is completed, the recording operation ends, and thereafter, the process shifts to step S4 to wait for the next event.

On the other hand, in step S10, a printer termination process is performed to stop the operation of the present apparatus. That is, in order to turn off the power of various motors and heads, the state is shifted to a state where the power can be turned off, and then the power is turned off and step S4
Go to and wait for the next event.

In step S11, other event processing other than the above is performed. For example, a process corresponding to a recovery command from various panel keys or an external I / F of the apparatus or a recovery event generated internally is performed. After the process is completed, the process proceeds to step S4 and waits for the next event.

FIG. 11 is a plan view showing a schematic configuration of the recording element substrate H1100 constituting the recording head of the above-described embodiment, as viewed from the ink ejection port side. FIG. 12 is a cross-sectional view taken along the line BB '.

The ink jet printer of this embodiment is
A heating element 2 as an electrothermal converter is arranged corresponding to each ejection port (nozzle) H1100T of the recording head.
The ink droplet is ejected from the ejection port H1100T by applying a drive signal based on the recording data to the printer. The heating elements 2 corresponding to each of the discharge ports H1100T are configured to be capable of independently generating heat. This heating element 2
The ink in the nozzle, which has been rapidly heated by the heat of the ink, generates bubbles due to film boiling, and the ink droplets 35 are ejected toward the recording medium 106 as shown in FIG. Characters and images can be recorded by forming dots of ink on 106. In addition,
As the ink ejection method, the present embodiment employs a so-called bubble-through method in which bubbles communicate with the outside air through a part of the ejection openings before the ink droplets leave the ejection openings, specifically, in the process of contracting the bubbles. belongs to.

As described above, the recording element substrate H1100
In addition, an ink flow path 3 communicating with each of the discharge ports H1100T is provided corresponding to each of the discharge ports H1100T, and the ink is supplied to these flow paths 3 behind the flow path 3. For this purpose, an ink supply path 4 is formed in the substrate 5. In the flow path 3 corresponding to each of the discharge ports H1100T, as described above, the heating element 2 as an electrothermal converter that generates thermal energy used to discharge ink droplets from these discharge ports, Is provided with an electrode wiring (not shown) for supplying electric power. These heating elements 2 and electrode wiring are made of a substrate 5 made of silicon or the like.
It is formed on the surface by a film forming technique. A protective film (not shown) is formed on the heating element 2 so that the ink does not directly contact the heating element 2. Further, the discharge port H1100T, the flow path 3, the ink supply path 4 of the substrate section, and the like are formed by laminating a partition wall 10 made of a resin or a glass material on the substrate 5.

FIG. 14 shows the entire printing element substrate H1100, and shows the structure for one color ink shown in FIG.
FIG. 4 is a plan view illustrating a color ink. In this embodiment,
As described above, printing is performed using inks of six colors of black, light cyan, light magenta, cyan, magenta, and yellow, and the printing element substrate H1100 is used.
Are the nozzle rows 11Bk, 11C ', 11
m ′, 11C, 11m, and 11Y. The nozzle rows for each color are composed of two rows, and the interval between the nozzle rows for each color is 1/2 inch, and they are arranged at equal intervals in the main scanning direction in the figure. The number of nozzles of each color ink is 256, and the nozzle rows are arranged so as to be substantially orthogonal to the main scanning direction.

Each of the two nozzle rows of each color ink has 128 nozzles arranged at a pitch of about 42 μm, and each of the two rows has a staggered pattern as shown in FIG. In other words, the two rows are arranged in a form shifted from each other by a half pitch of about 21 μm. As a result, a band for 256 nozzles can be added to 1200 bands in one main scan.
Recording can be performed at a resolution of dpi. The dimensions of each part and the number of nozzles described above do not limit the present invention. In the following description, for convenience of explanation, the embodiment of the present invention will be described for all ejections of 128 nozzles in one side row.

Next, the circuit configuration of each nozzle row in the printing element substrate H1100 will be described. FIG. 15 shows a circuit configuration for driving a print head formed on a print element substrate, and among two rows of nozzles for one color of ink,
FIG. 3 is a diagram illustrating a circuit configuration related to driving one nozzle row.

A discharge nozzle (heating element 2) H1,..., H128 corresponding to each discharge port is connected to a nozzle group N consisting of 128 discharge ports N1,.
The heat generated by the discharge heater heats the ink near the discharge port to generate bubbles. Then, an ink droplet is ejected from the ejection port by the pressure at which the bubble is generated.

Which discharge port is to be used for discharge is determined by the shift register 56 based on the image data IDATA sent from the control unit (not shown). The image data IDATA is input to the shift register 56 one bit at a time each time the clock signal DCLK is input. When the 32-bit image data is prepared in the shift register 56, these data are sent to the data latch circuit 57. The data latch circuit 57 has 12 data ports corresponding to each ejection port.
It has eight output terminals LT1,..., LT128,
A latch signal is output for each output terminal according to the input image data. Each output terminal is connected to an AND gate, and a latch signal is sent to the AND gate according to a clock signal LTCLK. In the AND gate, a logical product is obtained with driving signals D1,..., D16 for controlling driving timing inputted from another path in the circuit, and this logical product is used as an ejection signal. This is a signal for applying a voltage signal to the discharge heater. As a result, the discharge heater generates heat as described above.

Here, since all the 128 ejection heaters cannot send an amount of electricity that generates heat at a time, the ejection heaters are divided into 16 drive blocks of 8 units, and the heating operation is performed in units of these drive blocks. Done. Then, time-division driving is performed for each drive block in the division order mainly according to a predetermined rule determined in product design, and ink is ejected.

That is, the drive signals D1,..., D16 divided for each drive block are input to the AND gate. The drive signal D1 is a signal for driving eight ejection heaters of the block 1, the drive signal D2 is a signal for driving eight ejection heaters of the drive block 2, and the drive signal D15 is a signal for driving eight ejection heaters of the drive block 15. The drive signal D16 is a signal for driving eight ejection heaters of the drive block 16. Based on these drive signals and the latch signal from the data latch circuit 57, an ejection signal is created by an AND gate for each drive block.

The drive signals D1,..., D16 are
, Four block enable signals BENB0, BENB1, BENB sent from a control unit (not shown).
2, BENB3 and the heat enable signal HENB.

The block enable signal and the heat enable signal are output at a predetermined cycle as shown in FIG. 16, triggered by the input of the latch clock signal LTCLK.

That is, the heat enable signal HENB
Is to output pulse signals at the same interval 16 times with the input of the latch clock signal LTCLK as a trigger. When this heat enable signal is at “H level”, the discharge heater generates heat.

On the other hand, the block enable signal BENB
0, BENB1, BENB2 and BENB3 are output at different periods, respectively, with the input of the latch clock signal LTCLK as a trigger. The BENB value (also referred to as “order value”) is determined by the combination of the output states of the respective block enable signals. As shown in FIG.
0, BENB1, BENB2, and BENB3 are all at “L level”, the BENB value is set to 0, and BEBE
NB3 is “H level”, BENB0, BENB1, BE
When NB2 is at “L level”, the BENB value is set to “1”. The relationship between the BENB value thus determined and the block enable signal is as shown in FIG. Then, the decoder 54 outputs the drive signals D1,..., D16 according to the BENB value. Hereinafter, the output of the drive signal will be specifically described.

First, when the BENB value is 0, the driving signal D
1 is “H level”. Heat enable signal HEN
In the rising section of B (section B1 in FIG. 16), eight ejection heaters belonging to the drive block 1 are driven, and ink is ejected from eight nozzles corresponding to the ejection heaters.

After the BENB value 0 has been output for a certain period of time,
When the ENB value changes to 1, the drive signal D1 changes to "L level".
On the other hand, the drive signal D2 is set to “H level”. The rising section of the heat enable signal HENB (FIG. 16)
In the middle and B2 sections), eight ejection heaters belonging to the drive block 2 are driven, and ink is ejected from the eight corresponding nozzles.

After the BENB value 1 has been output for a certain period of time,
When the ENB value changes to 2, the drive signal D2 changes to "L level".
On the other hand, the drive signal D3 is set to “H level”. The rising section of the heat enable signal HENB (FIG. 16)
In the middle (B3 section), eight ejection heaters belonging to the drive block 3 are driven, and ink is ejected from eight corresponding nozzles.

Hereinafter, the same operation is performed.
After the NB value 14 has been output for a certain period of time, the BENB value
, The drive signal D15 is set to “L level”, while the drive signal D16 is set to “H level”. The rising edge of the heat enable signal HBNB (B in FIG. 16)
In the 16th section), eight ejection heaters belonging to the drive block 16 are driven, and ink is ejected from eight corresponding nozzles.

As described above, the latch clock signal LTCL
The cycle of each signal is determined based on K. Hereinafter, the cycle of the heat enable signal HENB is referred to as “block drive time interval”.

In the printer according to the present embodiment having the above-described configuration, a specific example will be described below in which the influence of the airflow caused by the event immediately before the ink ejection on the subsequent event is reduced.

Comparative Example 1 First, a comparative example will be described. In the comparative example, the ejection amount was 4.5 n as the recording head.
g, and a discharge speed of 18 m / s, 1200 dpi. The driving frequency of each nozzle is 15 kHz. Also,
The 128 nozzles are divided into 16 driving blocks and driven in a time-division manner, and the driving time interval of each block is 3.6 μs.
It is.

Under the above conditions, cyan (C) solid recording (recording with 100% duty) was performed on A4 size paper. That is, it discharges for all 128 nozzles,
This was continuously performed, and A4 size recording was performed.
As a result, by visual observation at a clear visual distance of 15 cm, white streaks were confirmed at the joint of the bands.

A detailed observation of this recording result was performed using a microscope or the like. As a result, all the ejections (events, that is, all the ejections performed during the nozzle ejection (driving) cycle) at the first time (start of recording) were performed. It is found that the landing dots in (discharge) do not have the above-described edge deviation, but the edge deviation has occurred in the second and subsequent events.

The present inventor has conducted intensive studies, and as a result,
The 128 droplet groups ejected in the previous event cause the airflow left in the space between the sheets (the space between the recording sheet and the orifice plate of the recording head) to be replaced by the 128 droplet groups ejected in the subsequent event Was found to have an effect on the landing position.

FIG. 18 is a diagram for explaining this phenomenon.
The droplet of each of the before event and the after event is schematically shown. In this figure, the z direction is the ink discharge direction (discharge in the negative direction), and the y direction is the paper feed (sub-scanning direction; see FIG. 14). Therefore, the recording head is shown in FIG.
8 is scanned in the direction perpendicular to the paper surface (main scanning direction; FIG. 1).
4).

In the example shown in the figure, the above-described block driving mode is a mode in which eight nozzles driven simultaneously are uniformly dispersed in the nozzle arrangement. The airflow generated by the previous event due to the block drive wraps around as a residual airflow behind the droplet group, and this airflow affects the flight direction of the droplet at the end of the subsequent event. As a result, it is presumed that the end portion is twisted.

A method for avoiding the influence of the residual airflow generated in the preceding event on the subsequent event will be described below.

[Embodiment 1] As shown in FIG. 18, the droplet position of the block driven last in the previous event and
There is a gap of about 228 μm between the drop position of the first driven block in the later event. This 22 exists after 128 droplet groups have passed by the previous event.
It is considered that the residual airflow caused by the surrounding air flowing into the gap of 8 μm acts on the droplet ejected in the later event to shift the landing position of the droplet as described above.

Therefore, the gap between the droplet position of the last drive block in the previous event and the droplet position of the first drive block in the subsequent event was narrowed.

FIG. 19 shows a specific first embodiment of the present invention, and is similar to FIG. That is, by extending the drive time interval between each block to 4.1 μs,
The 228 μm gap of Comparative Example 1 was narrowed to 93 μm
(The driving cycle of the nozzle is constant, and if the driving time interval between the blocks becomes longer, the mass of the entire droplet group in the event,
Since the width in the vertical direction in the figure increases, the gap becomes narrower). Other conditions are the same as in Comparative Example 1.

Under the above conditions, solid recording of cyan (C) was performed on A4 size paper in the same manner as in the comparative example. As a result, no white streak was observed at the joint position of the bands by visual observation at a clear visual distance of 15 cm.

[Comparative Example 2] Here, as another comparative example, the spatial distribution state of the droplet group of the event is not uniformly distributed in a substantially rectangular shape as shown in FIGS. ,
As shown in FIG. 20, in the case of a parallelogram having a short base with a short base, even if the drive time interval of each block is set to 4.1 μs as in the first embodiment, the block is obliquely large. The airflow occurs and affects the droplet group ejected in a later event, and the image quality is degraded due to a landing position defect that is not limited to white stripes.

The shape of the lump by the droplet group of this event is:
It depends on how the block drive is performed. FIG.
In the example shown in FIG. 0, in the nozzle arrangement, block driving is performed to simultaneously drive eight consecutive nozzles in even-numbered and odd-numbered arrangements. In this case, the rectangular shape is used as described above. Instead of a parallelogram.

As described above, as an index indicating the uniformity of the droplet distribution in the event, that is, an indication that the shape of the mass of the droplet group is almost rectangular, as shown in FIG. The area A1 of a region formed by connecting the droplets located at the outermost position of the group with a straight line, and [the nozzle driving cycle tr
× discharge speed v × maximum width w of droplets ejected at the same time], and the ratio to the virtual rectangular area A2 is used. Here, the maximum width w of simultaneously ejected droplets is defined as “the distance between droplets at both ends of a droplet group belonging to the same drive block is y.
The distance obtained by projecting on the z-plane ".

As the area ratio A1 / A2 takes a value closer to 1, the droplet distribution of the event can be considered to be more uniform, that is, a shape closer to a virtual rectangle. Of course, there is a case where A1 satisfies the condition that A1 is close to the value of A2 even if it is geometrically shaped as shown in FIG. Considering the use of a head, such a case does not exist. Therefore, it can be said that the above condition of the ratio indicates that it is actually close to a virtual rectangle. Arranging the nozzles at a relatively high nozzle density of 600 dpi is a necessary prerequisite for generating an airflow itself due to a cluster of events.

It is also apparent from FIG. 19 that the closer the ratio is to 1, the smaller the distance between the clusters of droplets due to the event, which is the distance of the space behind the event.

Here, as is clear from FIG. 21, the area A1 can be calculated as the sum of the areas of 15 parallelograms in the example shown in FIG. Although the 15 parallelograms have slightly different shapes, the bottom and the height are the same. Since the present example is a driving method for simultaneously driving eight nozzles every 15 nozzles, the base is (1 / 600 dpi × 25.4 ×
10 ⁴ μm) × 16 × 7 = 4741.3 μm, height is discharge speed (18 m / s) × block drive time interval (4.1
μs) = 73.8 μm, A1 = (1/600 dpi) × 25.4 × 10 ⁴ × 16 × 7 × 73.8 × 1
5 = 5248656.0.

On the other hand, the area A2 is obtained from [drive cycle tr × discharge speed v × simultaneous discharge droplet width w] as follows: A2 = (1/15 kHz) × (18 m / s) × [(1/600 dpi) × 25. 4
× 10 ⁴ μm × (16 × 7)] = 5689600.0

As described above, the area ratio A1 / A2 is A1 / A2 = 0.92 in the first embodiment, and A1 / A2 = 0.81 in the comparative example 1 described above. Are uniform.

As described above, in the present embodiment, by designing the block drive so that the above ratio takes a value 0.92 closer to 1, the droplet position of the last drive block of the previous event and the post-event The gap between the first driving block and the liquid drop position can be narrowed to 93 μm, and the spatial distribution of the liquid drop group between the sheets can be uniformly distributed in a substantially rectangular shape as shown in FIG. As a result, the residual airflow caused by the surrounding air flowing into the gap existing after the group of 128 droplets ejected in the previous event has passed acts on the droplets in the subsequent event to shift the landing position of the droplets. Is suppressed, so that white streaks can be reduced to the extent that white streaks cannot be confirmed at the seam of the band when observed with the naked eye at a clear visual distance of 15 cm.

Example 2 The gap between the droplet position of the last driving block discharged in the previous event and the droplet position of the first driving block discharged in the subsequent event was further narrowed. By setting the driving time interval of each block to 4.3 μs, which is larger than the case of 4.1 μs in the first embodiment, the droplet position of the last driving block discharged in the previous event and the liquid of the first driving block discharged in the subsequent event are set. The gap between the drop position and the drop position was 39 μm. Other conditions are the same as in Comparative Example 1.

Under the above conditions, cyan (C) solid recording was performed on A4 size paper. As a result, the clear visual distance 15
No white streaks were observed at the seam of the band by visual observation in cm. In the case of this example, the area ratio is A1 / A2 = 0.97.

[Comparative Example 3] Next, by setting the drive time interval of each block to 3.9 μs, the droplet position of the last drive block of the previous event and the droplet position of the first drive block of the subsequent event are set. Was widened to 147 μm. Other conditions are the same as in Comparative Example 1.

Under the above conditions, cyan (C) solid recording was performed on A4 size paper. As a result, the clear visual distance 15
In the observation with the naked eye in cm, a white streak was observed at the joint of the bands. At this time, the area ratio is A1 / A2 =
0.88.

Based on the above Examples and Comparative Examples,
If the area ratio A1 / A2 is 92% or more, the problem of white stripes due to the influence of the residual airflow can be solved.

[0125]

As is clear from the above description, according to the present invention, the ratio of the area A1 to the area A2 is 9%.
When it is 2% or more and less than 100%, a group of ink droplets ejected from 128 or more ejection ports in the print head during the drive cycle of the ejection ports is distributed in a substantially rectangular area, and in the same manner as described below. This is close to the ink droplet group ejected during one driving cycle. Thus, it is possible to reduce the occurrence of an airflow in which the ink drop group in the previous cycle affects the ink drop group in the next cycle.

As a result, the displacement of the landing position of the ink droplet is suppressed, so that the white streak can be suppressed to the extent that the white streak cannot be visually recognized at the joint of the bands.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating an external configuration of an inkjet printer according to an embodiment of the present invention.

FIG. 2 is a perspective view showing the state shown in FIG. 1 with an exterior member removed.

FIG. 3 is a perspective view showing a state where the recording head cartridge used in the embodiment of the present invention is assembled.

FIG. 4 is an exploded perspective view showing the recording head cartridge shown in FIG.

FIG. 5 is an exploded perspective view of the recording head shown in FIG. 4 as viewed obliquely from below.

FIG. 6 is a perspective view showing a scanner cartridge according to the embodiment of the present invention.

FIG. 7 is a block diagram schematically showing an overall configuration of an electric circuit according to the embodiment of the present invention.

FIG. 8 is a block diagram showing an internal configuration of a main PCB shown in FIG.

FIG. 9 is a block diagram showing an internal configuration of the ASIC shown in FIG.

FIG. 10 is a flowchart showing the operation of the embodiment of the present invention.

FIG. 11 is a plan view of a recording head according to the embodiment.

FIG. 12 is a sectional view of the recording head shown in FIG.

FIG. 13 is a diagram for explaining an ejection state in the recording head of the embodiment.

14 is a plan view showing the recording head shown in FIG. 11 for all ink colors.

FIG. 15 is a circuit diagram showing a drive circuit of the recording head.

FIG. 16 is a timing chart showing drive timing in the circuit.

FIG. 17 is a diagram showing a relationship between a BENB value and each block enable signal in the drive circuit.

FIG. 18 is a diagram illustrating a distribution state of droplet groups in an event relating to ink ejection in a comparative example.

FIG. 19 is a diagram illustrating a distribution state of a droplet group of an event relating to ink ejection in one embodiment of the present invention.

FIG. 20 is a diagram illustrating another comparative example of the distribution state of the droplet groups in the event.

FIG. 21 is a diagram for explaining a method of calculating the area A1 in the example of the present invention.

FIG. 22 is a diagram for explaining occurrence of white stripes.

[Explanation of symbols]

2 Heating Element 3 Liquid Path 4 Ink Supply Port 5 Base 10 Partition M1000 Device Main Body M1001 Lower Case M1002 Upper Case M1003 Access Cover M1004 Ejection Tray M2015 Sheet Interval Adjustment Lever M2003 Discharge Roller M3001 LF Roller M3019 Chassis M3022 Automatic Feeding Unit M3029 Unit M3030 Ejection unit M4001 Carriage M4002 Carriage cover M4007 Headset lever M4021 Carriage shaft M5000 Recovery system unit M6000 Scanner M6001 Scanner holder M6003 Scanner cover M6004 Scanner contact PCB M6005 Scanner illumination lens M6006 Scanner reading lens box 1 M6100 Storage box Box cover M6103 Box cap M6104 Storage box spring E0001 Carriage motor E0002 LF motor E0003 PG motor E0004 Encoder sensor E0005 Encoder scale E0006 Incempty sensor E0007 PE sensor E0008 GAP sensor (inter-sheet sensor) E0009 ASF sensor E0009 PG sensor E0011 Contact FPC (flexible filter) E0012 CRFFC (flexible flat cable) E0013 Carriage board E0014 Main board E0015 Power supply unit E0016 Parallel I / F E0017 Serial I / F E0018 Power key E0019 Resume key E0020 LED E0021 Buzzer E0022 Cover sensor E1001 CPU E10 2 OSC (Oscillator with built-in CPU) E1003 A / D (A / D converter with built-in CPU) E1004 ROM E1005 Oscillation circuit E1006 ASIC E1007 Reset circuit E1008 CR motor driver E1009 LF / PG motor driver E1010 Power control circuit E1011 INKS (Ink end detection signal E1012 TH (Thermistor temperature detection signal) E1013 HSENS (Head detection signal) E1014 Control bus E1015 RESET (Reset signal) E1016 RESUME (Resume key input) E1017 POWER (Power key input) E1018 BUZ (Buzzer signal) E1019 oscillation circuit E1020 ENC (Encoder signal) E1021 Head control signal E1022 VHON (Head power ON Signal) E1023 VMON (motor power ON signal) E1024 power control signal E1025 PES (PE detection signal) E1026 ASFS (ASF detection signal) E1027 GAPS (GAP detection signal) E0028 Serial I / F signal E1029 Serial I / F cable E1030 Parallel I / F signal E1031 Parallel I / F cable E1032 PGS (PG detection signal) E1033 PM control signal (pulse motor control signal) E1034 PG motor drive signal E1035 LF motor drive signal E1036 CR motor control signal E1037 CR motor drive signal E0038 LED drive signal E1039 VH (head power supply) E1040 VM (motor power supply) E1041 VDD (logic power supply) E1042 COVS (cover detection signal) E200 CPU I / F E2002 PLL E2003 DMA controller E2004 DRAM controller E2005 DRAM E2006 1284 I / F E2007 USB I / F E2008 Reception controller E2009 Compression / expansion DMA E2010 Reception buffer E2011 Work buffer E2012 Work area DMA EDMA 2013 E2014 Print buffer E2015 Print data expansion DMA E2016 Expansion data buffer E2017 Column buffer E2018 Head control unit E2019 Encoder signal processing unit E2020 CR motor control unit E2021 LF / PG motor control unit E2022 Sensor signal processing unit E2023 Motor control buffer E20204 Scanner capture buffer E2025 Scanner data processing DMA 2026 Scanner data buffer E2027 Scanner data compression DMA E2028 Transmission buffer E2029 Port controller E2030 LED controller E2031 CLK (clock signal) E2032 PDWM (software control signal) E2033 PLLON (PLL control signal) E2034 INT (interrupt signal) E2036 PIF received data E2037 USB reception data E2038 WDIF (reception data / raster data) E2039 reception buffer control unit E2040 RDWK (reception buffer read data /
Raster data) E2041 WDWK (work buffer write data /
Recording code) E2042 WDWF (work fill data) E2043 RDWP (work buffer read data / recording code) E2044 WDWP (rearrangement recording code) E2045 RDHDG (recording / development data) E2047 WHDDG (column buffer write / development recording data) E2048 RDHD (column buffer read data / development record data) E2049 Head drive timing signal E2050 data development timing signal E2051 RDPM (pulse motor drive table read data) E2052 sensor detection signal E2053 WDHD (taken data) E2054 RDAV (take buffer read data) E2055 WDAV (data buffer write data /
E2056 RDYC (data buffer read data / processed data) E2057 WDYC (transmission buffer write data / compressed data) E2058 RDUSB (USB transmission data / compression data) E2059 RDPIF (1284 transmission data) H1000 recording head cartridge H1001 recording Head H1100 Recording element substrate H1100T Discharge port H1200 First plate H1201 Ink supply port H1300 Electric wiring board H1301 External signal input terminal H1400 Second plate H1500 Tank holder H1501 Ink flow path H1600 Flow path forming member H1700 Filter H1800 Seal rubber H1900 Ink tank

Claims (8)

[Claims] 1. An array of 12 ink ejection nozzles arranged in a line.
Using a recording head having eight or more ejection ports at an array density of 600 dpi or more, a plurality of ejection ports of the recording head are driven in a time-division manner, and recording is performed by ejecting ink from the plurality of ejection ports to a recording medium. In the ink jet recording method, when the ink ejection direction is a z-direction in a rectangular coordinate system and the scanning direction of the recording head is an x-direction, the recording head in the recording head during one cycle of a driving cycle for one ejection port. By ejecting from 128 or more ejection openings corresponding to one row, a virtual area obtained by projecting an ink droplet group distributed in an area between the recording head and the recording medium onto the yz plane. The area Al of the region formed by connecting the centers of the ink droplets located at the outermost position of the ink droplet group with a straight line is represented by: A2 = the driving cycle (t r) × ejection speed (v) × the maximum width (w) of ink droplets ejected by simultaneous driving in the time-division driving, where the maximum width of ink droplets ejected by simultaneous driving in the time-division driving is 92% or more of the area A2 obtained from the distance obtained by projecting the distance between the ink droplets at both ends of the ink droplet group belonging to the simultaneous driving and ejected onto the yz plane.
An inkjet recording method characterized by being less than 00%. 2. When an event is ejection from the 128 or more ejection ports performed during one cycle of the driving cycle of the one ejection port, an ink droplet group due to ejection in the last drive block of the event The distance between the ink droplet group due to the ejection applied to the first drive block of the subsequent event is the time interval and the ejection speed of the block drive of the time-division drive.
and (v).
3. The inkjet recording method according to item 1. 3. The ink jet recording method according to claim 1, wherein the recording head generates bubbles in the ink by thermal energy, and discharges the ink based on a change in volume of the bubbles. 4. The ink jet recording method according to claim 3, wherein the bubbles communicate with the outside air when the bubbles shrink in volume. 5. An array of 12 ink ejection nozzles arranged in a line.
Using a recording head having eight or more ejection ports at an array density of 600 dpi or more, a plurality of ejection ports of the recording head are driven in a time-division manner, and recording is performed by ejecting ink from the plurality of ejection ports to a recording medium. In the ink jet recording apparatus, when an ink ejection direction is a z direction in a rectangular coordinate system, and a scanning direction of the recording head is an x direction, during one cycle of a driving cycle for one ejection port, By ejecting from 128 or more ejection openings corresponding to one row, a virtual area obtained by projecting an ink droplet group distributed in an area between the recording head and the recording medium onto the yz plane. The area Al of the region formed by connecting the centers of the ink droplets located at the outermost position of the ink droplet group with a straight line is represented by: A2 = the driving cycle (t r) × ejection speed (v) × the maximum width (w) of ink droplets ejected by simultaneous driving in the time-division driving, where the maximum width of ink droplets ejected by simultaneous driving in the time-division driving is 92% or more of the area A2 obtained from the distance obtained by projecting the distance between the ink droplets at both ends of the ink droplet group belonging to the simultaneous driving and ejected onto the yz plane.
An ink jet recording apparatus characterized by being less than 00%. 6. An ink droplet group formed by ejection in the last drive block of an event, wherein an event is ejection from the 128 or more ejection ports performed during one drive cycle of the one ejection port. The distance between the ink droplet group due to the ejection applied to the first drive block of the subsequent event is the time interval and the ejection speed of the block drive of the time-division drive.
6. The method according to claim 5, wherein the value is obtained based on (v).
3. The ink jet recording apparatus according to claim 1. 7. The ink jet recording apparatus according to claim 5, wherein the recording head generates bubbles in the ink by thermal energy, and discharges the ink based on a change in volume of the bubbles. 8. The ink jet recording apparatus according to claim 7, wherein the air bubbles communicate with the outside air when the air bubbles shrink in volume.