JPH0760968A - Ink jet recording apparatus - Google Patents

Abstract

PURPOSE:To avoid lowering the recording density even in the same quantity of ink discharge as in a conventional manner by forming an ink jet recording apparatus capable of multipath recording to have a driving order of discharge elements being variable every recording path. CONSTITUTION:A nozzle driving order is such that Nos. 1, 2 nozzles are driven at first in the first path, and the reminder nozzles Nos.3, 4 are not driven and the order is moved to an adjacent line of dots. Since the driving interval between No.1 nozzle and No.2 nozzle is made twice as long as (t) 1 in a conventional manner, the interval between No.1 nozzle and No.2 nozzle in the X direction becomes twice relative to a conventional manner. Similarly, in the second path, No.3 nozzle and No.4 nozzle are driven at a time interval being twice as long as (t) 1. In this instance, the maximum time interval can be controlled to (t) 1X3 times because it is two path printing. Herein, adjacent upper and lower dots are disposed so that each dot is allowed not to overlap with each other ununiformly in consequence of its relation among the recording density P, dot diameter (d) and driving differential L, thereby ensuring printing density having no recording medium viewed therein.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus such as a dot matrix type printer.

[0002]

2. Description of the Related Art A dot matrix type printer of this kind as a recording device for recording an image such as a character or an image on a recording medium by a set of dots is provided with a plurality of dot forming portions. These are usually recorded (printed)
It is called a head and takes various forms depending on the recording method. As an example, in the case of an inkjet printer,
The print head is composed of a plurality of ink ejection nozzles. As a drive system of this type of print head, there are a division drive system and a block drive system.

FIG. 13 shows an example of a dot arrangement diagram of a conventional divided drive system. The dot intervals in the X and Y directions are set to P, which is smaller than this distance so that dots cannot be formed from the same nozzle. That is, the interval becomes the maximum recording density of this recording apparatus, and the reciprocal of the time for moving the distance P becomes the maximum drive frequency of the nozzle.

In the case of such a divisional drive system, the drive of a plurality of vertically aligned nozzles is divided into several groups,
The nozzles in this group are driven while sequentially shifting the time. The deviation of the driving time in this example is t
The interval t1 is 1 and is a value restricted by the hardware or software configuration of the recording apparatus.

In the case of FIG. The driving order of 1 to 4 nozzles is No. The order is 1, 3, 2, and 4, and in the example of FIG. 13, four vertical dots are ejected from one group. As an example, 32 or 64 dots are arranged in the vertical direction, and each group No. The nozzles 1 to 4 are driven at the same timing.

On the other hand, the block driving method is a driving method in which all nozzles in a group are driven at the same timing, and these groups are regarded as blocks and the driving of each block is sequentially switched. An example of this drive state is shown in FIG.
Shown in. In this conventional example, No. in block B1 is set. The four nozzles are driven first, and are sequentially driven to blocks B2, B3, B4. The drive time interval of each of these blocks is t
2 is shown in the figure. Regarding each printing method, if you want to emphasize the color such as black, you can print the same dots in the same position for 1 or 2 times multiple times without thinning out to make the ink bleed and increase the density (bold printing). ) Is also used.

[0007]

However, the recording medium usually called plain paper has a great difference in the ink bleeding characteristics, and depending on the recording medium, even in each of the above driving methods, for example, FIG. 15 and FIG. As can be seen from No. 16, there is a drawback that a gap is generated between the dots due to the relationship between the landing diameter d and the recording density P (white portion), and the surface of the recording medium is exposed to lower the print density. was there.

The present invention has been made in view of the problems caused by the respective conventional driving methods as described above, and it is possible to reduce the recording (printing) density as described above even with an ink ejection amount equivalent to that of the conventional example. Not intended for regular use of the recording head drive system.

[0009]

For this reason, in the present invention, an ink jet which has a recording head for forming dots by using a plurality of ink ejection elements and recording on a recording medium, and is capable of multi-pass recording It is an object of the present invention to achieve the above-mentioned object by making the driving order of the ejection elements variable in each printing pass in the printing apparatus.

[0010]

According to the configuration of the present invention as described above, the dot arrangement on the recording medium can be optimized by changing the nozzle driving order of the recording head according to the landing diameter and the dot density, and the area factor becomes large. High density recording (printing) results are obtained.

[0011]

EXAMPLES The present invention will be described below based on examples; (First Example) In this example, the nozzle driving order is optimized during thinning multi-pass printing in the division driving method to solve the above problems. To do. Hereinafter, the case of print recording will be described. In the case of 1-pass printing, in FIG. 13 of the conventional example, it is necessary to drive four nozzles in one group, and it is difficult in time to arrange dots so that they do not overlap as much as possible. However, in the first embodiment, the print duty per one pass is reduced by thinning out, and the print head is scanned a plurality of times by this amount to allow a sufficient drive time, thereby enabling an appropriate arrangement. It was

FIG. 1 shows a first embodiment of the dot arrangement of the divisional driving system (corresponding to FIG. 13). d is the landing diameter, and P is the dot spacing. The nozzle drive order is N for the first pass.
o. The remaining Nos. 1 and 2 are driven. The 3rd and 4th nozzles are not driven and the operation moves to the driving of the adjacent dot row. No. 1 nozzle and N
o. Since the drive interval with the two nozzles is twice the t1 of the conventional example, No. 1 nozzle and No. 2 nozzle X
The directional spacing is twice that of the conventional example. Similarly, the second pass is N
o. 3 nozzles and No. The four nozzles are driven at a time interval twice as long as t1. In the case of the present embodiment, since it is 2-pass printing, the maximum time interval can be adjusted up to t1 × 3 times.

The dot of the first nozzle in the first row is set to D (1,1)
Expressing that, it is most efficient to arrange the dots so that the center distance between D (1,2) and D (1,1) and the center distance between D (2,1) and D (1,2) are equal. The surface of the recording medium can be covered with ink drops. As shown in FIG. 1, adjacent upper and lower dots are recorded with a recording density P, a dot diameter d, and a drive difference L.
Therefore, by arranging the dots so that they do not overlap unevenly, it is possible to secure the print density without seeing the recording medium portion. FIG. 2 shows a print example (black circles) of the print result by the dot arrangement of this embodiment.

(Second Embodiment) FIG. 3 shows a second embodiment of the present invention.
An example of a dot arrangement diagram by block-passing 4-pass thinning printing is shown. 4 nozzles / block, blocks B1-B
Drive up to 4. That is, each block is divided into two, for example, No. Set of 1 and 3 nozzles and No. Divide into groups of 2 and 4 nozzles. If it is a B1 block, the former combination is called block B 1 and the latter combination is called block B 1 ′. Similarly, the blocks up to B4 are divided, and these are divided into four scans for drive printing. In the first pass, blocks B1 and B3 'are driven and printed. The interval between the blocks B1 and B3 'is set to twice the time t2 in FIG. 14 of the conventional example. The second pass includes blocks B2 and B4 ', the third pass includes blocks B3 and B1', and the fourth pass includes block B.
4 and B2 'are driven respectively.

FIG. 4 shows a print row in which four rows are printed by the above method. In this way, the adjacent upper and lower dots are alternately positioned, and the overlapping of the dots is made small, so that the area factor becomes large and a high print density can be obtained without exposing the surface of the recording medium. This embodiment is also the first
Similar to the embodiment, the drive interval of the blocks B1 and B3 is t
Since it is possible to adjust up to 2 × 3 times, there are two possible dot arrangements in each pass other than FIG. FIG. 5 shows a second printing example when the above interval is t2 × 3, and FIG. 6 shows a third printing example when the interval is t2.

(Third Embodiment) FIG. 7 shows a third embodiment of the present invention.
An example of an efficient dot arrangement diagram for increasing the density in bold printing during block driving is shown. In the printing of the first pass indicated by the black circles, the blocks B1 to B4 are sequentially driven and printed at the driving interval t2 as in the case of the conventional example shown in FIG. Two
In the pass, as shown by the white circles in FIG. 7, printing is performed by reversely driving from B4 block to B1 on the recording medium. In multi-pass bold printing, the driving order of blocks is changed for each printing pass. FIG. 8 shows a printing example of the printing result by the above-mentioned driving method that can reduce the dot overlap on the medium and increase the area factor to improve the density. For example, it can be clearly seen that the visible portion (white portion) of the recording medium is reduced as compared with the conventional printing example shown in FIG.

(Fourth Embodiment) In the fourth embodiment, in order to further increase the area factor of bold printing, dot arrangement drawing of a case of performing thinning printing (bold thinning printing) so that the block drive interval can be arbitrarily set An example is shown in FIG. The blocks B1 and B2 are driven at an interval twice the drive interval t2 of the conventional example in the first pass (black circle part), and the blocks B3 and B4 are in the second pass, and the blocks B2 and B1 are in the second pass. Is printed, and blocks B4 and B3 are sequentially driven in the fourth pass. In this way, by shifting the first dot landing point and the second landing point, the area factor is increased and the density can be improved. FIG. 10 shows a print example of the print result of the fourth embodiment. It can be clearly seen that there is no gap between dots and a high density can be obtained.

Also in this embodiment, the drive interval of each block can be selected similarly to the above-mentioned embodiments, and the second printing example when the above interval is t2 is shown in FIG. 11 and when the interval is t2 × 3 times. Three
FIG. 12 shows an example of the printout of each. In the description of the present embodiment, the combination of drive blocks for each path is B1 + B2 and B3.
Although only + B4 is described, the present invention is not limited to this, and it is needless to say that the same effect can be obtained by using other combinations.

Incidentally, the present invention brings excellent effects particularly in a recording apparatus of the type which utilizes thermal energy among ink jet recording apparatuses.

With regard to its typical structure and principle, see, for example, US Pat. Nos. 4,723,129 and 4740.
What is done using the basic principles disclosed in 796 is preferred. This method is a so-called on-demand type,
It can be applied to any of the continuous type, but especially in the case of the on-demand type, it can be applied to the sheet holding the liquid (ink) or the electrothermal converter arranged corresponding to the flow path. By applying at least one drive signal corresponding to the recorded information and causing a rapid temperature rise beyond nucleate boiling, heat energy is generated in the electrothermal converter, and film boiling occurs on the heat-acting surface of the recording head. As a result, bubbles can be formed in the liquid (ink) in a one-to-one correspondence with this drive signal, which is effective. The liquid (ink) is ejected through the ejection openings by the growth and contraction of the bubbles to form at least one droplet. It is more preferable to make this drive signal into a pulse shape, because the bubble growth and contraction are immediately and appropriately performed, so that the ejection of the liquid (ink) with excellent responsiveness can be achieved. As the pulse-shaped drive signal, U.S. Pat. Nos. 4,463,359 and 4,345 are used.
Those as described in the '262 patent are suitable. If the conditions described in US Pat. No. 4,313,244 of the invention relating to the rate of temperature rise of the heat acting surface are adopted, further excellent recording can be performed.

As the constitution of the recording head, in addition to the combination constitution of the discharge port, the flow passage, and the electrothermal converter (the linear liquid passage or the right-angled liquid passage) as disclosed in the above-mentioned specifications, The configurations using US Pat. No. 4,558,333 and US Pat. No. 4,459,600, which disclose the configuration in which the heat acting portion is arranged in the bending region, are also effective in the present invention. In addition, Japanese Unexamined Patent Publication No. 59-123670 discloses a configuration in which a common slit is used as a discharge portion of the electrothermal converter for a plurality of electrothermal converters, and an opening for absorbing a pressure wave of thermal energy is provided. The present invention is also effective as a configuration based on Japanese Patent Application Laid-Open No. 59-138461, which discloses a configuration corresponding to the ejection portion.

[0022]

As described above, according to the present invention,
By driving the nozzles of the recording head so that the adjacent upper and lower dots are arranged with a small overlap and a large area factor, it is possible to increase the recording density even with the same ink ejection amount as the conventional one.

[Brief description of drawings]

FIG. 1 is a dot arrangement example of a divided drive system according to a first embodiment.

FIG. 2 is a printing example of the first embodiment.

FIG. 3 is an example of a dot arrangement diagram of a block driving method according to a second embodiment.

FIG. 4 is a printing example of the second embodiment.

FIG. 5 is an example of printing by the second dot arrangement of the second embodiment.

FIG. 6 is an example of printing with a third dot arrangement of the second embodiment.

FIG. 7 is an example of a dot arrangement diagram of a block driving method according to a third embodiment.

FIG. 8 is a printing example of the third embodiment.

FIG. 9 is an example of dot arrangement diagram of block driving method of the fourth embodiment.

FIG. 10 is a printing example of the fourth embodiment.

FIG. 11 is a second printing example of the fourth embodiment.

FIG. 12 is a third printing example of the fourth embodiment.

FIG. 13 is an example of a dot arrangement diagram of a conventional division drive system.

FIG. 14: Example of conventional block drive system dot layout diagram

FIG. 15: Printing example of conventional division drive method

FIG. 16: Printing example of conventional block drive method

[Explanation of symbols]

 P dot interval t1, t2 dot drive time interval 1 to 4 nozzle number B1 to B4 block number

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical display location B41J 3/04 104 H (72) Inventor Hitoshi Sugimoto 3-30-2 Shimomaruko, Ota-ku, Tokyo Kya Non-Incorporated (72) Inventor Miyuki Matsubara 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (4)

[Claims] 1. An ink jet recording apparatus having a recording head for forming dots using a plurality of ink ejection elements and recording on a recording medium, and capable of multi-pass recording, wherein the ejection elements are driven in different order. An inkjet recording apparatus, which is configured to be variable for each recording pass. 2. The ink jet recording apparatus according to claim 1, wherein the ejection order or the driving timing is set so that the difference between the centers of the dots ejected by the recording head on the recording medium becomes small. . 3. A bold print by multi-pass scanning of the print head, wherein the landing positions of dots ejected from the same element on the print medium are different for each pass. Inkjet recording device. 4. The recording head is provided for each of a plurality of ejecting sections for ejecting ink, and the corresponding ejecting section, and causes the ink to undergo a state change due to heat, and the ink is ejected from the ejecting section based on the state change. The inkjet recording apparatus according to claim 1, further comprising: a thermal energy generating unit that discharges the droplets to form flying droplets.