JP2002086733A - Method of ink jet recording and ink jet recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a driving frequency characteristic, a durability and a reliability and to suppress recording variation. SOLUTION: Two hundreds fifty five (one hundred twenty eight in one side) electrothermal conversion elements 14 in segments 0-255 are arranged at both sides of an ink supply hole 15 in the longitudinal direction thereof. The electrothermal conversion elements 14 are arranged in a line in a staggered fashion in 600 DPI. The electrothermal conversion elements 14 in the segments 0-255 are divided into blocks in which the electrothermal conversion elements 14 are heated at roughly the same time. The electrothermal conversion elements 14 in the segments 0-31 are divided into total 16 blocks in such a manner that the electrothermal conversion element 14 in the segment 0 and the electrothermal conversion elements 14 in the segment 1 are in the block 0 and the electrothermal conversion elements 14 in the segment 2 and the electrothermal conversion elements 14 in the segment 3 are in the block 1.

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 method and an ink jet recording apparatus for performing a recording operation by discharging a liquid such as ink.

[0002]

2. Description of the Related Art Ink jet recording methods widely used today include an ink jet recording method using an electrothermal transducer (heater) as a discharge energy generating element used for discharging ink droplets, and a piezoelectric device. (Piezo)
There are methods using elements, and in each case, the ejection of ink droplets can be controlled by an electrical signal. For example, the principle of an ink droplet ejection method using an electrothermal conversion element is that, by giving an electric signal to the electrothermal conversion element, the ink near the electrothermal conversion element is instantaneously boiled, and the phase change of the ink at that time causes The ink droplets are ejected at a high speed by the rapid growth of bubbles. on the other hand,
The principle of the method of ejecting ink droplets using a piezoelectric element is that the piezoelectric element is displaced by applying an electric signal to the piezoelectric element and the ink droplet is ejected by the pressure at the time of this displacement. The former method has the advantages that the space for the ejection energy generating element does not need to be provided so much, the structure of the ink jet recording head is simple, and the nozzles can be easily integrated. On the other hand, the disadvantages inherent in this method include a change in volume of flying ink droplets due to heat storage in the ink jet recording head due to heat generated by the electrothermal conversion element and an effect of cavitation due to defoaming on the electrothermal conversion element.

In an ink jet recording head, when a plurality of energy generating elements are formed, it is not usual to simultaneously apply energy to all of the plurality of energy generating elements. Specifically, when an electric signal is applied to the electrothermal transducers at the same time, the current flowing at the same time increases, so that a power supply capable of supplying a large current is required, resulting in poor efficiency. Further, a voltage drop occurs in the wiring between the power supply and the electrothermal transducer, so that the efficiency is reduced. Therefore, a plurality of electrothermal transducers are driven in a time-sharing manner.

In a so-called edge shooter type ink jet recording head, a discharge is performed in a direction having a certain angle (acute angle) including 0 °, instead of discharging in a substantially vertical direction from a discharge port facing the electrothermal transducer. Since the ejection openings are arranged in a straight line, the dot landing position may be shifted when time-division driving is performed. For this reason, the ejection dots are arranged obliquely at a certain angle so that the landing dots are straightened in one line. But,
When block drive is performed, another block that performs ejection follows the block that has completed ejection,
It was easy to visually recognize the dot displacement.

On the other hand, in a so-called side shooter type ink jet recording head which discharges in a substantially vertical direction from a discharge port facing the electrothermal transducer, a landing deviation generated when time-division driving is performed as shown in FIG. The positions of the electrothermal transducers 414 arranged on both sides of the ink supply port 415 and the positions of the ejection ports are shifted by an amount so that the landing dots are aligned. For example, in the ink jet recording head shown in FIG. 19, as shown in Tables 1 and 2, the electrothermal transducer 414 has a maximum displacement of 18 μm in the X direction, that is, 1200 DPI.

[0006]

[Table 1]

[0007]

[Table 2]

[0008]

However, in the conventional side shooter type ink jet recording head, since the position of the electrothermal conversion element is shifted, the electrothermal conversion element is moved from the ink supply port for supplying ink into the nozzle. In an ejection port having a relatively long distance to the nozzle, the time from ejection to refilling (refilling) of the ink with the nozzle takes more time, so that high-speed response is deteriorated. In addition, if the ejection is performed at a timing that cannot be refilled in time, an ejection failure may occur or the ejection amount may decrease.

In addition, the longer the distance from the ink supply port to the electrothermal conversion element, the greater the inertial resistance in the initial stage of energization and foaming when the electrothermal conversion element is energized. It is easy to grow on the outlet side, and therefore, the ink discharge amount is larger than that discharged from the discharge port where the distance from the ink supply port to the electrothermal conversion element is short, which tends to be uneven, and the discharge speed is relatively high. In some cases, there is a problem that the landing deviation cannot be accurately corrected because of the large size.

Further, since the wiring resistance between the electrothermal conversion element and the driving element depends on the distance from the ink supply port to the electrothermal conversion element, the wiring resistance does not become uniform. The required energy varies.
Therefore, energy is applied according to the electrothermal conversion element that requires the most energy, and the durability of the electrothermal conversion element may be reduced.

In the ink jet recording head, when the ink is ejected from the non-recording state due to the evaporation of the ink from the ejection port, the ejection failure such as a non-ejection or a discharge failure such as a shove with a small ejection amount occurs. There is a phenomenon.
This one-shot characteristic tends to be deteriorated as the distance from the ink supply port to the electrothermal transducer becomes longer, because the ink is hardly supplied when the evaporation of the ink progresses. The effect was more noticeable as the size became smaller. In addition, the position of the electrothermal conversion element and the discharge port is shifted to correct the landing deviation, and the discharge port that is farther from the adjacent discharge port is more reduced in the effect of suppressing evaporation due to the evaporation atmosphere from the discharge port. Failure of the first characteristic was easy to occur. Relatedly, as a result of the ink evaporating from the ejection port and increasing the ink density at the ejection port, the density of the ejected landing dots may increase. In a side shooter type head in which the arrangement positions of the ejection ports are shifted as described above and the distance between the ink supply port and the electrothermal transducer is different for each ejection port, the ink supply capacity from the ink supply port is different for each ejection port. Therefore, the density of the impact dot differs for each ejection port, which may cause a decrease in print quality. This problem also becomes more remarkable as the droplet size is smaller and the distance between the discharge port and the electrothermal transducer is smaller (such as a discharge method in which bubbles generated by the electrothermal transducer communicate with the atmosphere). .

[0012]

Means for Solving the Problems The present inventors have determined that the smaller the ink discharge droplet amount is 9 pl or less, and further 5 pl or less, and / or the density of the electrothermal conversion elements arranged in a row is 600 DPI or more. The larger the size, the more the ink supply to solve the shift rather than the technical problem (hereinafter, referred to as “first technical problem”) caused by the shift of the landing dots due to the time-division driving of the electrothermal transducers arranged on a straight line. The above-described technical problem (hereinafter, referred to as “second technical problem”) due to the imbalance resulting from varying the distance from the mouth to the electrothermal transducer for each electrothermal transducer emerges. Thus, the present invention has been accomplished. In other words, the present invention has been made as a result of optimizing to solve the first technical problem and the second technical problem from a comprehensive point of view.

An object of the present invention is to provide an ink jet recording method and an ink jet recording apparatus having improved driving frequency characteristics.

Another object of the present invention is to reduce recording unevenness,
An object of the present invention is to provide an ink jet recording method and an ink jet recording apparatus with improved recording quality.

Still another object of the present invention is to provide an ink jet recording method and an ink jet recording apparatus in which the durability and reliability of a head are improved.

Still another object of the present invention is to provide an ink jet recording method and an ink jet recording apparatus having improved firing characteristics. Still another object of the present invention is to provide
An ink supply port for supplying ink, a plurality of ink flow paths communicating with the ink supply port, and thermal energy used for discharging ink provided in each of the plurality of ink flow paths. Generated, a plurality of electrothermal conversion elements arranged on a substantially straight line along the longitudinal direction of the ink supply port, and respectively communicate with the plurality of ink flow paths and face each of the plurality of electrothermal conversion elements. Provided is an ink jet recording method, characterized in that recording is performed by dispersively driving the plurality of electrothermal transducers using an ink jet recording head provided with a plurality of ejection ports for ejecting ink. That is.

Still another object of the present invention is to provide an ink supply port for supplying ink, a plurality of ink flow paths communicating with the ink supply port, and a plurality of ink flow paths provided in the plurality of ink flow paths, respectively. A plurality of electrothermal conversion elements that generate thermal energy used for discharging ink and are arranged on a substantially straight line along a longitudinal direction of the ink supply port, and communicate with the plurality of ink flow paths, respectively. A plurality of ejection ports for ejecting ink, which are provided to face the plurality of electrothermal conversion elements, respectively, and an ink jet recording head, and a control unit that drives the plurality of electrothermal conversion elements in a distributed manner, An ink jet recording apparatus comprising:

According to the present invention, it is possible to dramatically improve overall performance such as driving frequency characteristics, recording quality, head durability, and firing characteristics.

[0019]

Next, embodiments of the present invention will be described with reference to the drawings. Here, in the present specification, “driving the ejection port” or “driving the electrothermal conversion element” means that the electrothermal conversion element provided corresponding to the ejection port generates heat, generates bubbles in the ink, and discharges the ink. This means discharging ink from the outlet. Further, “block driving” means that a group of ejection ports physically adjacent to each other are simultaneously driven, and each group is sequentially driven. “Sequentially dispersed driving” means that a group of ejection ports physically adjacent to each other are sequentially driven, and the groups are driven in synchronization with each other. The mere “distributed driving” means that physically adjacent ejection ports are driven as different blocks, and the adjacent ejection ports are not sequentially driven. (First Embodiment) FIG. 1 is an external perspective view of a recording head cartridge showing a basic form of the present embodiment.
FIG. 2 is a schematic partially cutaway perspective view of a recording element substrate for discharging ink, provided in the recording head shown in FIG. 1. FIG. 3 is a partial cross-sectional view of the recording element substrate 12 taken along line AA ′ of FIG. 2, and FIG.
FIG. 4 is a perspective plan view of the vicinity of the electrothermal conversion element 14 viewed from the direction of FIG.

As shown in FIG. 1, a recording head cartridge 11 which is removably mounted on an ink jet recording apparatus 501 to be described later and is reciprocally scanned in the X direction has a plurality of discharge ports 16 for discharging ink. Element substrate 12
And an inkjet recording head 516 having the following. The recording head cartridge 11 includes a recording element substrate 12
An ink tank (not shown) for supplying ink to the printer is detachably mounted. An example is shown in which the recording head cartridge 11 of the present embodiment can mount six ink tanks storing six color inks. In addition, as the colors of the six colors of ink stored in the ink tank, a color ink that is a color other than black and a black ink may be stored.

In the ejection port array formed of a plurality of ejection ports 16 formed on the recording element substrate 12 shown in FIG. 1, two ejection port arrays are formed for each color, that is, a total of 12 ejection port arrays are formed. Are shown.

As shown in FIG. 2, the printing element substrate 12
For example, a thin film is formed on the Si substrate 19 having a thickness of 0.5 to 1 mm. In addition, six rows of ink supply ports 15 each of which is a long groove-shaped through-hole for supplying ink of six colors are formed, and the electrothermal conversion elements 14 are arranged in a zigzag pattern on both sides of each of the ink supply ports 15. The electrothermal transducers 14 are arranged, and the electrical wiring (see FIG. 7) made of Al or the like for supplying electric power to the electrothermal transducers 14 is formed by a film forming technique. Further, a bump made of Au or the like is provided on the electrode portion 18 for supplying electric power to the electric wiring. The ink supply port 15 performs anisotropic etching using the crystal orientation of the Si substrate 19. <100> on the wafer surface,
When the crystal has a <111> crystal orientation in the thickness direction, the etching proceeds by anisotropic etching of an alkaline system (KOH, TMAH, human azine, etc.). Using this method,
Etch to desired depth. Alternatively, the ink supply port 15 may be formed by the AE-POLY method disclosed in JP-A-10-181332. In the case of the AE-POLY method, since the ink supply port 15 can be formed with high precision, it is possible to further reduce the variation in the distance CH described later, which is preferable.

On the Si substrate 19, the electrothermal transducer 14
The ink flow path wall 20 and the discharge port 16 for forming the ink flow path 13 corresponding to the above are formed by photolithography technology, and the above-described 12 discharge port rows 10 corresponding to the six color inks are formed. I have. Also, each electrothermal conversion element 14 is provided so as to face each discharge port 16,
The ink supplied from the ink supply port 15 is generated by the electrothermal transducer 14 to generate bubbles, and the ink is discharged from the discharge port 16 so that recording is performed on a recording medium such as recording paper. When the ink is ejected, a configuration may be adopted in which bubbles formed on the electrothermal transducer 14 are communicated with the atmosphere via the ejection port 16. Also, discharge port 1
The diameter of the dot formed on the recording medium by the ink ejected from 6 to once is preferably 55 μm or less.

Next, the dimensions of each part will be described.
Each numerical value shown below shows an example, and is not limited to these.

As shown in FIGS. 3 and 4, each ink flow path 13 is partitioned by an ink flow path wall 20, but in the present embodiment, the ink flow path wall 20 is
5a, and is separated from the ink supply port end 15a by a distance a from the ink flow path wall end 20a. In this embodiment, the ink supply port end 1
Although the configuration shown in FIG. 5A is separated from the ink flow path wall end 20a by a distance a, the present invention is not limited to this.
The distance a may be zero, that is, the ink flow path wall end 20a may extend to the ink supply port end 15a.

The distance CH from the element end 14a, which is the end of the electrothermal conversion element 14 on the side close to the ink supply port 15, to the ink supply port end 15a is determined by the distance CH from the ink supply port 15 to the electrothermal conversion element 14. If the CH distance is less than or equal to 20 μm, bubbling for ejecting liquid droplets is more likely to grow toward the ink supply port 15 side, which may cause unstable ejection. Therefore, the distance CH is preferably 20 μm or more. .
In the present embodiment, the distance CH is set to 45.5 μm for all the electrothermal transducers 14. Conventional inkjet recording heads have a structure in which the distance CH is longer than the distance CH in the present embodiment. For this reason, in many cases, the singularity is poor. In the embodiment, the uniform distance C is relatively shorter than the distance CH of the conventional inkjet recording head.
Since H is adopted, the singularity is improved. Furthermore, it is possible to suppress variations in the ejection amount and the ejection speed of the ink between the ejection ports.

The flow path height t1 of the ink flow path 13 is 16 μm
The distance t2 from the electrothermal transducer 14 to the end face of the outlet 16 on the outlet side, that is, the surface of the recording element substrate 12
Is 25 μm.

Next, FIG. 5 is a schematic plan view of electrothermal transducers arranged linearly on both sides of one ink supply port.
FIG. 6 is a partially enlarged view of FIG. In addition, the number shown beside each electrothermal conversion element has shown the segment of each electrothermal conversion element.

The shape of the electrothermal transducer 14 of this embodiment is a square of 24 μm × 24 μm as shown in FIG. 4, but is not limited to this. As shown in FIGS. 5 and 6, the electrothermal conversion element 14 has a total of 256 (128 on each side) segments 0 to 255 on both sides in the longitudinal direction of the ink supply port 15 having a width in the short direction of 100 μm. The heat conversion elements 14 are arranged. These electrothermal transducers 14 are arranged in a staggered pattern at a pitch of 600 DPI. The center-to-center distance W1 of each electrothermal conversion element 14 across the ink supply port 15 may be 215 μm.

In this embodiment, each electrothermal conversion element 14 is arranged in a straight line, so that each electrothermal conversion element 14
7 (a) and 7 (b), which drive the respective electrothermal transducers 14, can be equally arranged. Therefore, each wiring 17a for electrically connecting each electrothermal conversion element 14 and each driving element 24 has an equal length. That is, since the wiring resistance of all the wirings 17a can be made equal,
The electric power applied to the electrothermal transducer 14 can be applied uniformly without being influenced by the wiring resistance of the wiring 17a. Therefore, since unnecessary power is not applied to the electrothermal transducer 14, the durability of the electrothermal transducer 14 can be improved.

Next, FIG. 8 shows a perspective view of an ink jet recording apparatus on which the ink jet recording head of this embodiment can be mounted.

The main body chassis 512 has a guide shaft 5
The carriage 508 is mounted on the guide shaft 503 so as to be slidable in the direction of arrow B '.
The carriage 508 is mounted on a timing belt 505 stretched between a drive pulley 506 coupled to a drive motor (not shown) and an idler pulley 507.
8 is fixed, and can reciprocate in the direction of arrow B ′ along the guide shaft 503 according to the rotation of the drive motor. The ejection port 16 of the recording head cartridge 11 having the ink jet recording head 516 is formed to face downward in the figure, and performs recording on the recording paper 504 as a recording medium by ejecting ink from the ejection port 16.

The recording head cartridge 11 is removably mounted on the carriage 508, and is connected to a main body chassis 512 via a flexible cable 502 for transmitting and receiving a current and a signal for driving the recording head cartridge 11.
Is electrically connected to a control board 517 which is a board for controlling the recording apparatus main body, which is attached to the back of the printer. As shown in the block diagram of FIG. 9, the control substrate 517 includes an electrothermal conversion element 14 of the recording element substrate 12.
Is provided with a control unit 518 for controlling the driving order of the.

Next, a method of driving each electrothermal transducer 14 by the control unit 518 will be described with reference to FIG.

[0035]

[Table 3]

Each of the electrothermal transducers 14 of the segments 0 to 255 is divided into blocks in which the electrothermal transducers 14 that generate heat substantially simultaneously are put together.

For example, in each of the electrothermal transducers 14 of the segments 0 to 31, the electrothermal transducer 14 of the segment 0 and the electrothermal transducer 14 of the segment 1 belong to the block 0, and the electrothermal transducer 14 of the segment 2 The electrothermal conversion elements 14 of the segment 3 are divided into blocks 1 and so on, so that a total of 16 blocks are divided. In FIG.
Blocks 0-5 are shown. That is, this block division is performed by a so-called control unit 518 in which the electrothermal conversion elements 14 are divided into blocks so that the electrothermal conversion elements 14 adjacent in the direction in which the electrothermal conversion elements 14 are arranged substantially linearly are not included in the same block. Is possible, for example,
Segment 0 arranged on the left side of the ink supply port 15
And the segment 2 are divided so that heat is not generated at the same time.

Here, the term “substantially simultaneous” as used herein means a deviation of the ejection timing in consideration of the moving speed of the ink jet recording head 516 and the center distance W 1 of each electrothermal transducer 14. For example, in block 0, segment 0 and segment 1 are provided apart from each other by a center-to-center distance W1.
Numeral 16 moves at a set moving speed at the time of recording. Therefore, the segments 0 and 1 do not generate heat at the same time,
The heat is generated with a slight shift in the ejection timing in consideration of the moving speed 16 and the distance W1 between the centers of the electrothermal transducers 14. Therefore, they are not simultaneous but substantially simultaneous.

Since the ejection volume of the ink slightly differs in each block, recording unevenness may occur when the adjacent electrothermal transducers 14 are included in the same block. The non-uniform recording can be reduced by making the electrothermal conversion elements 14 to be different blocks and performing distributed driving as in the present embodiment.

The difference in timing for each block, for example,
The block interval, which is the time interval between the block 0 and the block 1 from the time when the block 0 is driven to the time when the driven block 1 is driven after the driven block 0 is 2.1 μs. This block interval is, for example,
In the segments 0 to 31, the control unit 518 is configured to be substantially equal between any of the blocks 0 to 15.
Is controlled by The deviation of the dot center in the main scanning direction in one column is about 17 μm. In this embodiment, the block interval is set as small as (40/16) μs.
Is driven to be close to the value of. Naturally, if the block interval is shortened, the deviation of the center of the dot in one column in the main scanning direction can be reduced, but the time during which ejection is not performed in one column becomes longer, and vibration occurs in the head. Therefore, it is driven close to (40/16) μs.

The ink jet recording head 516 having the above configuration performs recording at a 1200 DPI pitch while scanning in the X direction. The drive frequency can be driven at 25 kHz, and the shortest time interval is about 40 μs at one discharge port 16.
The ejection is performed every time. As described above, in the inkjet recording head 516 of the present embodiment, since the distance CH is the same in any of the electrothermal transducers 14, it is possible to eliminate variations in the driving frequency. In addition, the inkjet recording apparatus 501 of the present embodiment has a longer distance C than necessary.
Since there is no H, the driving frequency can be increased, so that the time from when the ink is ejected to when the ink is refilled is shortened, and high-speed printing becomes possible.

Further, the volume of the discharged droplet discharged from one discharge port 16 of the ink jet recording head 516 of this embodiment is smaller than the general volume of the discharged liquid droplet discharged from the conventional ink jet recording head. 9 pl or less. For this reason, it is possible to prevent the landing deviation generated when each of the electrothermal conversion elements 14 is aligned from being visually detected. Further, by using an ink having a lower color material density than ordinary ink, it is also effective when it is difficult to visually detect landing dots themselves.

As described above, according to the ink jet recording head and the ink jet recording apparatus of this embodiment, since the distance CH is a uniform length, the driving frequency can be improved, the recording unevenness can be reduced, the durability can be further improved. Was able to improve reliability. (Second Embodiment) Next, distributed driving by the control unit of the ink jet recording apparatus according to the present embodiment will be described with reference to FIG. Note that the ink jet recording head and the ink jet recording apparatus of the present embodiment are basically the same as the ink jet recording head and the ink jet recording apparatus described in the first embodiment, except that the dispersion driving method described below is different. Therefore, detailed description is omitted.

[0044]

[Table 4]

In the present embodiment, each of the electrothermal converting elements 114 of the segments 0 to 31 is divided into 16 blocks as in the first embodiment. The combination of the conversion elements 114 is different from that of the first embodiment.

That is, the block division of this embodiment is as follows.
The electrothermal conversion elements 114 are divided into blocks so that the electrothermal conversion elements 114 adjacent to each other in the direction in which the electrothermal conversion elements 114 are substantially linearly arranged are not included in the same block. Electrothermal transducer 11 of the block driven following the block in which
4 are divided so as not to be adjacent to each other, and are divided so that the electrothermal conversion elements 114 adjacent to each other across the ink supply port 115 are not included.

The relationship of the above block division will be specifically described with reference to FIG.

Segment 0 of block 0 and block 2
The segment 2 is an electrothermal conversion element that is adjacent in the direction arranged in a substantially straight line, but does not generate heat at the same time because it belongs to a different block.

After the block 0 is driven, the electrothermal transducer 114 of the block 1 generates heat.
Is neither adjacent to segment 0 or segment 15 belonging to block 0.

In block 0, segment 0
And the segment 15 are not adjacent to each other with the ink supply port 115 interposed therebetween.

In this embodiment, the blocks are divided as described above, and ink is ejected in the order of blocks.

In FIG. 11 and Table 4, the electrothermal transducer 114 on the left side of the ink supply port 215 is shown as the EVEN side, and the electrothermal transducer 114 on the right side is shown as the ODD side.

As described above, the driving control is performed in the divided blocks, so that it is possible to reduce the recording unevenness caused by the configuration in which the adjacent electrothermal transducers are included in the same block.

As described above, according to the ink jet recording head and the ink jet recording apparatus of the present embodiment, as in the first embodiment, since the distance CH is a uniform length, the driving frequency can be improved and the recording unevenness can be improved. , Improvement in durability, and further improvement in reliability. (Third Embodiment) Next, FIG. 12 is a schematic partially enlarged plan view of electrothermal transducers arranged linearly on both sides of one ink supply port of the present embodiment.

As shown in FIG. 12, Tables 5 and 6, the electrothermal transducers 214 of the present embodiment are arranged on a substantially straight line with the X direction deviation b having a maximum width of 9 μm.
Each electrothermal conversion element 214 across the ink supply port 215
Is basically the same as in the first and second embodiments, except that the center-to-center distance W2 is 245 μm, and a detailed description thereof will be omitted. In FIG. 12 and Tables 5 and 6, the X-direction displacement b is 9 μm at maximum, but may be 10 μm at maximum. That is, the ink supply port 215 of each electrothermal conversion element 214
May be configured such that the center line in the longitudinal direction exists within 10 μm in width, or the configuration may be such that the difference in CH distance is within 10 μm.

[0056]

[Table 5]

[0057]

[Table 6]

In the case of the present embodiment, although not arranged in a straight line like the electrothermal transducers 14 and 114 of the first and second embodiments, the above-mentioned displacement b in the X direction is 9 μm or 10 μm. Is a numerical value of a pitch corresponding to 2400 DPI, which is half of 21.2 μm which is a pitch of 1200 DPI. For this reason, although it is not arranged on a straight line, the deviation b in the X direction is slight, so that the electrothermal conversion elements 214 are arranged on a substantially straight line, and the electrothermal conversion elements 14 and 114 are not linearly arranged. The same effects as the effects of the first and second embodiments obtained by being arranged above can also be obtained in the ink jet recording head of the present embodiment.

That is, also in the ink jet recording head and the ink jet recording apparatus of the present embodiment, since the distance CH is the same length as in the first and second embodiments, the driving frequency is improved and the recording unevenness is reduced. Thus, the durability, and the reliability of the starting point can be improved.

Although the present invention has been described by way of examples of embodiments, the present invention is not limited to these examples, and the numerical values shown in the above-described embodiments are merely examples, and the present invention is not limited to these. Not something. Examples of the above embodiments will be described below, but the present invention is not limited thereto.

[0061]

EXAMPLES (First Example) In this example, various recording media, recording resolutions, and ejection droplet sizes are used for various recordings using the ink jet recording head described in the first embodiment. A pattern was recorded.

The recording conditions and observation conditions in the present embodiment will be described below.

[0063]

[Table 7]

The ink is ejected under the above conditions,
A study was made on whether or not the landing displacement at the vertical ruled line could be recognized when viewed from a distance of m, by five subjects not involved in the development of images and the like. (First Comparative Example) As a first comparative example, only the driving method of the electrothermal transducer is changed from the distributed driving to the so-called block driving shown in FIG. 13 and Table 8, and the other is the same as the first embodiment. Under the same conditions, various recording patterns were recorded with various types of recording media, recording resolutions, and ejection droplet sizes.

[0065]

[Table 8]

The block driving used in this comparative example is to divide each electrothermal converting element 314 of segments 0 to 255 into 16 blocks. For example, segment 0
Each of the fifteen electrothermal conversion elements 314 is defined as block 0, and each of the electrothermal conversion elements 314 of the segments 16 to 31 is divided into blocks such as block 1. That is, the adjacent electrothermal conversion elements 314 generate heat simultaneously, and the electrothermal conversion element 314 of the driven block and the electrothermal conversion element 314 of the block driven following the driven block are adjacent to each other. It is divided into blocks. (Second Comparative Example) As a second comparative example, using the conventional ink jet recording head shown in FIG. 19, as in the first embodiment, various types of recording media, recording resolutions, and ejection droplets were used. Various recording patterns were recorded at different sizes.

The recording conditions and observation conditions in this comparative example are shown below.

[0068]

[Table 9]

The results obtained in the first embodiment and the first and second comparative examples performed under the above conditions are shown below.

FIG. 16 shows the landing deviation determination result obtained in the first embodiment. FIG. 16 shows only the determination result of the Bk ink. Also, FIG. 16 shows the case where the landing deviation is recognized as 1 and the case where the landing deviation is not recognized is 0.

As shown in FIG. 16, in the case of Bk, when the maximum dot center distance is 39.7 or 59.5 μm, although a landing deviation is recognized, the maximum dot center distance = 9.
At 9, 19.8 and 29.8 μm, no landing deviation was recognized. On the other hand, although not shown, for the C, M, and Y colors, no landing deviation was recognized even at 39.7 μm. Thus, the maximum dot center distance = 29.
Since 8 μm corresponds to about 800 DPI, 800 DPI
At pitches finer than PI, it has been found that recording can be performed with accuracy that does not recognize landing deviations due to distributed driving regardless of the ink color.

FIG. 14 is a diagram showing the state of impact at the joint between scans according to the first embodiment, and FIG.
FIGS. 15A and 15B show the state of impact at the joint between scans according to the comparative example. That is, FIGS. 14 and 15 show the landing deviation due to the difference between the distributed driving used in the first embodiment and the block driving used in the first comparative example.

In the case of the block drive, as shown in FIG. 15, it was recognized that the linearity of the ruled line was lost due to the landing deviation at the seam C 'between the scans. On the other hand, in the case of the distributed driving, as shown in FIG. 14, a clear landing deviation was not recognized at the joint C between the scans, and it was recognized that the linearity of the ruled line was ensured.

Next, FIG. 18 shows the frequency characteristics of the refills obtained in the first embodiment and the second comparative example. In FIG. 18, white circles indicate measured values according to the first embodiment, and black circles indicate measured values according to the second comparative example.

The driving frequency of the second comparative example is determined by the longest distance CH. That is, the driving frequency of the second comparative example is 15 kHz because the distance CH is in the range of 45.5 to 63.5 μm and is affected by the longest distance 63.5 μm, which is not suitable for high-speed recording.

On the other hand, in the case of the first embodiment, when the distance CH is 4
The driving frequency is 25 kHz because it is constant at 5.5 μm.
And it can be driven at a high frequency,
It has been clarified that the time from when the ink is ejected to when the ink is refilled is reduced, and high-speed printing is possible.

When the first shot, which is the time when the first shot was recorded normally, was measured in an environment of 15 ° C./10%, the first shot was also measured as shown in Table 10 for the first shot. In the case of the example, since the distance CH is constant and is not affected by the long distance CH as in the second comparative example, the second comparative example is 3 seconds. In Example 1, the time was 5 seconds, and it was also confirmed that the singularity was improved.

[0078]

[Table 10]

Next, in the ink jet recording head of the first embodiment, the distance CH was changed from 12 μm to 62 μm, and the result of observing the limit of the occurrence of a defective ink ejection failure is shown in FIG. 17 and Table 11.

[0080]

[Table 11]

When the distance CH is less than 20 μm, the discharge amount decreases and a shot may occur.
When the thickness was set to 0 μm or more, it was found that no emboss was generated and good ejection characteristics were obtained. (Second Embodiment) In this embodiment, FIG.
Using the dispersion driving method described in Table 1 and Table 4, various recording patterns were recorded with various types of recording media, recording resolutions, and ejection droplet sizes.

The recording conditions and observation conditions in the present embodiment will be described below.

[0083]

[Table 12]

In this embodiment, when the maximum dot center distance is 59.5 μm with Bk ink, although the landing deviation is recognized, the maximum dot center distance = 9.9,
At 19.8, 29.8 and 39.7 μm, no landing deviation was recognized. Also, for C, M, and Y colors,
Similar to Bk, no misalignment was recognized except for 59.5 μm. Thus, the maximum dot center distance = 39.7.
Since μm corresponds to about 600 DPI, 600 DP
At pitches finer than I, it has been found that accurate recording can be performed without recognizing landing deviation due to divisional driving regardless of the ink color.

In addition, in this embodiment, similarly to the result of the first embodiment, no clear landing deviation is recognized at the joint between scans, and the linearity of the ruled line is ensured. It was recognized, and it was confirmed that the improvement of the frequency characteristic and the first performance were also ensured for 5 seconds. (Third Embodiment) In the present embodiment, an ink jet recording head having a displacement in the X direction of 9 μm described in the third embodiment is used, and various types of recording media, recording resolutions, and ejection droplet sizes are used. Various recording patterns were recorded.

The recording conditions and observation conditions in the present embodiment will be described below.

[0087]

[Table 13]

In the case of the present embodiment, as shown in Table 14, the spontaneity was 1 second shorter than the first and second embodiments, but could be secured 1 second longer than the second comparative example. It was confirmed that.

[0089]

[Table 14]

Although the frequency characteristic is also 20 kHz, which is 5 kHz lower than that of the first and second embodiments, the deviation b in the X direction is 18 μm, that is, better than that of the second comparative example corresponding to 1200 DPI. confirmed.

In addition, in this embodiment, the landing deviation is the first
Good results similar to the results of the Examples of
No clear landing deviation was recognized at the joint between the scans, and it was recognized that the linearity of the ruled line was ensured.

[0092]

As described above, in the present invention, the distances from the ink supply ports to the respective electrothermal transducers are equal. Therefore, the length of each wiring for supplying electric power for driving the electrothermal transducer can be made uniform, and the durability can be improved. Further, the distance from the ink supply port to each electrothermal conversion element is relatively short. As a result, not only the driving frequency of each electrothermal conversion element can be made uniform, but also the driving frequency can be increased, while improving the emission characteristics.

Further, the ink jet recording apparatus according to the present invention is divided into each electrothermal conversion element for ejecting ink substantially simultaneously, and each electrothermal conversion element adjacent in the direction in which each electrothermal conversion element is arranged substantially linearly. The control unit drives the electrothermal conversion elements of a plurality of blocks that are divided so as not to include the conversion elements. Therefore, it is possible to suppress the occurrence of recording unevenness that has occurred due to the block division having the configuration including the electrothermal conversion elements adjacent to each other in the direction arranged in a substantially straight line.

[Brief description of the drawings]

FIG. 1 is an external perspective view of an ink jet recording head according to a first embodiment of the present invention.

FIG. 2 is a partially cutaway perspective view of a recording element substrate provided in the ink jet recording head shown in FIG.

FIG. 3 is a partial cross-sectional view of the recording element substrate taken along line AA ′ of FIG. 2;

4 is a perspective plan view of the vicinity of the electrothermal conversion element viewed from the direction of arrow B shown in FIG.

FIG. 5 is a schematic plan view illustrating an arrangement of electrothermal transducers in the inkjet recording head according to the first embodiment of the present invention.

FIG. 6 is a partially enlarged view of FIG. 5;

FIG. 7 is a plan view showing a wiring connected to the electrothermal transducer, and a drive circuit diagram of the electrothermal transducer.

FIG. 8 is a perspective view of the inkjet recording apparatus according to the first embodiment of the present invention.

FIG. 9 is a block diagram illustrating a control unit.

FIG. 10 is a diagram for describing block division by distributed driving according to the first embodiment of this invention.

FIG. 11 is a diagram for describing block division by distributed driving according to the second embodiment of this invention.

FIG. 12 is a view showing an arrangement of an electrothermal conversion element according to a third embodiment of the present invention.

FIG. 13 is a diagram for describing block division by block driving in the first comparative example.

FIG. 14 is a graph showing a landing deviation determination result obtained in the first embodiment of the present invention.

FIG. 15 is a diagram showing a state of landing at a seam between scans in the case of distributed driving obtained in the first embodiment of the present invention.

FIG. 16 is a diagram showing a state of landing at a seam between scans in the case of block driving obtained in the first comparative example.

FIG. 17 is a diagram showing a refill frequency characteristic.

FIG. 18 is a graph showing the relationship between the discharge amount of ink from each discharge port and the distance CH.

FIG. 19 is a schematic plan view showing an example of an arrangement of electrothermal transducers in a conventional inkjet recording head.

[Explanation of symbols]

 REFERENCE SIGNS LIST 11 recording head cartridge 12 recording element substrate 13 ink flow path 14, 114, 214, 314 electrothermal conversion element 14a element end 15, 115, 215, 315 ink supply port 15a ink supply port end 16 ejection port 17a, 17b wiring Reference Signs List 18 electrode part 19 Si substrate 20 ink flow path wall 20a ink flow path wall end 24 drive element 501 inkjet recording device 502 flexible cable 503 cap unit 504 recording paper 505 paper feed tray 506 cap member 507 wiper blade 508 carriage 509 guide shaft 510 Timing belt 511 Carriage motor 512 Body chassis 513 Drive pulley 514 Idler pulley 515 Ink tank 516 Ink jet recording head 517 Control board 18 control unit

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Norihiro Kawadoko 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Hiroshi Taka 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Incorporated F term (reference) 2C056 EA04 EA21 EC69 FA03 FA10 HA05 2C057 AF06 AF65 AG15 AG31 AG46 AG84 AN01 AP21 AR03 BA13

Claims (12)

[Claims] An ink supply port for supplying ink, a plurality of ink flow paths communicating with the ink supply port, and a plurality of ink flow paths provided in the plurality of ink flow paths for discharging ink. A plurality of electrothermal conversion elements arranged in a substantially straight line along the longitudinal direction of the ink supply port, and the plurality of electrothermal conversion elements respectively communicating with the plurality of ink flow paths. An inkjet recording head having a plurality of ejection ports for ejecting ink, each of which is provided to face each other, and performs recording by dispersively driving the plurality of electrothermal conversion elements. Recording method. 2. An ink supply port for supplying ink, a plurality of ink flow paths communicating with the ink supply port, and a plurality of ink flow paths respectively provided in the plurality of ink flow paths for discharging ink. A plurality of electrothermal conversion elements arranged in a substantially straight line along the longitudinal direction of the ink supply port, and the plurality of electrothermal conversion elements respectively communicating with the plurality of ink flow paths. And a plurality of ejection ports for ejecting ink, each provided facing each other, and an ink-jet recording head, and a control unit for dispersively driving the plurality of electrothermal conversion elements, Inkjet recording device. 3. The ink jet recording apparatus according to claim 2, wherein the distance from the ink supply port to the ends of the plurality of electrothermal conversion elements on the side closer to the ink supply port is 20 μm or more. 4. A wiring for electrically connecting the plurality of driving elements for applying power to the plurality of electrothermal conversion elements and the plurality of electrothermal conversion elements, respectively, having substantially the same length. 4. The ink jet recording apparatus according to 2 or 3. 5. The ink jet recording apparatus according to claim 2, wherein an amount of ink ejected from said ejection port at one time is 9 pl or less. 6. The ink jet recording apparatus according to claim 2, wherein a diameter of a dot formed on the recording medium by ink ejected from the ejection port at one time is 55 μm or less. 7. The ink jet recording apparatus according to claim 2, wherein a side wall of the ink flow path is not formed up to an end of the ink supply port. 8. A center line of each of the plurality of electrothermal transducers along a longitudinal direction of the ink supply port is present in an area having a width of 10 μm or less along the longitudinal direction of the ink supply port. An ink jet recording apparatus according to claim 2. 9. The ink jet recording apparatus according to claim 2, wherein the density of the recording performed by the ink jet recording head is 1200 DPI or more. 10. The ink jet recording apparatus according to claim 2, wherein the array density of the plurality of electrothermal transducers arranged on the substantially straight line is 600 DPI or more. 11. The ink jet recording apparatus according to claim 2, wherein bubbles generated by the thermal energy generated by the electrothermal conversion element are communicated with the atmosphere through the discharge port to discharge ink. 12. The ink supply port according to claim 2, wherein the ink supply port is formed by an AE-POLY method.
12. The ink-jet recording apparatus according to any one of items 11.