JPH03213343A - Ink jet recording device - Google Patents

Abstract

PURPOSE:To prevent the occurrence of a trouble to an ink delivery port due to ink mist by a method wherein the arranging direction of ink delivery ports formed in the delivery surface of a recording head is set in a manner to be inclined within a range of a specified angle with a relative movement direction. CONSTITUTION:A recording head 7 where a plurality of ink delivery ports 9 are aligned is provided. Ink is delivered through a plurality of the ink delivery ports 9 toward a material 2A to be recorded as the one of the recording head 7 and the material 2A to be recorded is relatively moved to the other. The ink delivery ports 9 are located in a manner that the aligning direction of the ink delivery port is inclined within a range of an angle of 15-75 deg. with a relative movement direction. This constitution sets an aligning distance between the ink delivery ports to a high value and reduces probability for ink mist to be adhered to the adjoining ink delivery port.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an inkjet recording device, and in detail,
The present invention relates to an inkjet recording apparatus such as a pressure pulse type using a piezoelectric element or a bubble jet type in which ink is ejected by generating bubbles in the ink using an electrothermal transducer.

[Prior Art] Conventionally, in this type of inkjet recording apparatus, one of the recording head and the recording material, which performs recording by ejecting ink, is moved relative to the other, and the recording head is moved in accordance with the timing of the movement. Recording is performed, but normally multiple ink ejection ports are arranged on the ink ejection surface of the print head in a direction perpendicular to the printing direction (hereinafter referred to as the row direction), and printing is performed from these ink ejection ports. Ink droplets are selectively ejected in accordance with the signals, forming ink dots on the recording material to perform recording.

[Problems to be Solved by the Invention] However, in such conventional inkjet recording devices, ink ejection ports are arranged in a direction perpendicular to the recording direction, so ink is ejected from multiple ink ejection ports simultaneously. If you do so, ink mist will be generated, and the ink mist will adhere to and accumulate around the ink ejection ports, clogging the ink ejection ports or disturbing the direction of ink flight, causing ink kinks, which may affect the recording quality. There was a problem with the loss of . Further, this tendency is particularly strong as the arrangement interval of the ink ejection ports becomes narrower, and this has been one of the constraints on obtaining high quality images through high-density recording.

The purpose of the present invention is to focus on the above-mentioned conventional problems, and in order to solve the problems, it is an object of the present invention to provide inkjet recording that suppresses the generation of ink mist, thereby keeping the ink ejection ports normal and capable of forming high-density recorded images. The goal is to provide equipment.

[Means for Solving the Problems] In order to achieve the above object, the present invention has a recording head in which a plurality of ink ejection ports are arranged, and either the recording head or the recording material is connected to the other. In an inkjet recording apparatus that performs recording by ejecting ink from the plurality of ink ejection ports toward the recording material while moving the recording material relatively, the arrangement direction of the ink ejection ports is set in the relative movement direction. It is characterized by being installed at an angle of 15° to 75°.

[Function] According to the present invention, by tilting the arrangement direction of the ink ejection orifices with respect to the direction of relative movement of either the recording head or the recording material with respect to the other, the ink can be reduced for the same recording density. Since the arrangement interval of the ejection ports can be set wide, the probability of ink mist adhering to adjacent ink ejection ports can be reduced, preventing the ink ejection ports from being blocked or the ejection direction being bent. It can be prevented.

[Examples] Examples of the present invention will be described below in detail and specifically based on the drawings.

FIG. 1 shows an embodiment of the present invention, and FIG. 2 shows a state in which printing is performed by the print head of the ink jet printing apparatus shown in FIG.

In FIG. 1, 1 is a cassette for feeding recording sheets 2, 3 is a feeding roller that feeds recording sheets 2 one by one from cassette 1, and 4 is a feeding roller that records recording sheets 2 in accordance with the recording timing. Registration rollers 5 are used to send the recording sheet 2 to a certain position, and 5 is a conveyor belt that conveys the recording sheet 2. Further, in this example, a suction fan 6 is provided on the back side of the conveyor belt 5, and the recording sheet 2 can be attracted and held onto the conveyor belt 5 by this fan 6.

Reference numeral 7 denotes a recording head that performs recording by ejecting ink from a position opposite to the recording sheet 2A that has been guided to the recording position, and 8 denotes an ink supply means that supplies ink to the recording head 7. Here, the recording head 7 is moved in a direction perpendicular to the paper surface by a moving means (not shown), and printing is performed in the row direction during this movement, but in this example, the row of ink ejection ports 9 of the recording head 7 is As shown in FIG. 2, it is maintained at a predetermined angle with respect to the row direction, 45 degrees in this example.

In this way, the recording head 7 moves in the upward direction of the arrow A in FIG. 2 with respect to the recording sheet 2A held on the conveyor belt 5, and at a predetermined timing corresponding to the sequential movement from the diagonally arranged ink ejection ports 9. Ink is ejected and printing is performed in the row direction as shown in the figure. Note that after one line of recording is completed, the sheet is fed by one line by the conveyor belt 5, and when the entire recording on the recording sheet 2A is completed, the recorded sheet is unloaded by the discharge roller lO shown in FIG. It is discharged into the illustrated tray, etc.

Here, the reason why the arrangement direction of the ink ejection ports 9 is inclined with respect to the row direction is that if we consider the case where the angle of inclination (hereinafter referred to as the inclination angle) is 45 degrees, the interval between the ejection ports in the vertical direction is can be increased by 1.4 times compared to before,
Therefore, it is possible to reduce the influence of ink mist generated from an ejection port on adjacent ejection ports. Further, by widening the interval between the ejection ports in this manner, the area for receiving ink mist is expanded, and the probability that the ink ejection ports will be blocked by the mist is reduced accordingly.

In addition, the present inventors confirmed through experiments that the tilt angle is related to recording results, as shown below. That is,
According to experiments, as is clear from Table 1 below, as the angle between the array of ink ejection ports and the row direction is tilted from the conventional 90° to Oo, the area near the ink ejection ports becomes smaller within a certain angle range. It was confirmed that recording defects caused by dirt were improved.

Table 1゜ The grade result is ○.

△ and
The number of lines in which a recording failure occurred was counted in 100% recording using a recording head having ink ejection orifices arranged at a density of el. However, in reality, recording with a recording density of 100% is not normally performed, so there is no problem as long as the number of lines with recording defects is 20 or less. Therefore, based on the experimental results, it can be seen that recording is improved if the inclination angle is between 75° and 151°.

FIG. 3 shows a second embodiment of the invention. In this example, the arrangement of ink ejection ports is divided into two halves, an upper half and a lower half, and the upper half ejection port row 9A and the lower half ejection port row 9B are kept parallel to each other, and the row direction They are made to avoid overlapping each other, and at the same time are tilted at a predetermined angle, for example, 45 degrees with respect to the row direction. FIG. 4 shows a third embodiment of the present invention in which the ink ejection ports 9 are arranged in a staggered manner, and the entire ink ejection port array 9c arranged in this way is similarly inclined with respect to the row direction. Therefore, even if the structure is configured as in the second and third embodiments, the same effects as described in the first embodiment can be obtained.

It should be noted that the present invention provides excellent effects particularly in bubble jet recording heads and recording apparatuses among ink jet recording systems.

This is because such a system can achieve higher recording density and higher definition.

As for typical configurations and principles thereof, it is preferable to use the basic principles disclosed in, for example, US Pat. No. 4,723,129 and US Pat. No. 4,740,796. This method can be applied to both the so-called on-demand type and continuous type, but especially in the case of the on-demand type, it is necessary to arrange the liquid (ink) in accordance with the sheet and liquid path that hold it. The electrothermal converter that is
Generating thermal energy in the electrothermal transducer and producing film boiling on the thermally active surface of the recording head by applying at least one drive signal that corresponds to recorded information and provides a rapid temperature rise above nucleate boiling. As a result, bubbles in the liquid (ink) can be formed in a one-to-one correspondence with this drive signal, which is effective. The growth and contraction of this bubble causes the liquid (ink) to be ejected through the ejection opening to form a small droplet (at least one droplet).If this drive signal is in the form of a pulse, the growth and contraction of the bubble will occur immediately and appropriately. Because it will be
Particularly responsive liquid (ink) ejection can be achieved,
More preferred. This pulse-shaped drive signal is described in U.S. Pat. Nos. 4,463,359 and 4,345,262.
Those described in the specification are suitable. Furthermore, if the conditions described in US Pat. No. 4,313,124 concerning the invention regarding the temperature increase rate of the heat acting surface are adopted, even more excellent recording can be performed.

The configuration of the recording head includes, in addition to the combination configuration of ejection ports, liquid paths, and electrothermal converters (straight liquid flow path or right-angled liquid flow path) as disclosed in the above-mentioned specifications, a heat acting section. The present invention also includes configurations using US Pat. No. 4,558,333 and US Pat. No. 4,459,600, which disclose configurations in which the wafer is placed in a bending region. In addition, Japanese Patent Application Laid-Open No. 1989-5 discloses a configuration in which a common slit is used as a discharge part of a plurality of electrothermal converters.
No. 9-123670 and Japanese Patent Application Laid-Open No. 59/1989 which discloses a configuration compatible with an open discharge part that absorbs pressure waves of thermal energy.
The effects of the present invention are also effective even if the structure is based on the publication No.-138461. In other words, regardless of the form of the recording head, recording can be performed reliably and efficiently.

Furthermore, the present invention can be effectively applied to a full-line type recording head having a length corresponding to the maximum width of a recording medium that can be recorded by a recording apparatus.

Such a recording head may have either a configuration in which the length is satisfied by a combination of a plurality of recording heads, or a configuration as a single recording head formed integrally. In addition, even the serial type shown above can be installed on the main body of the device, allowing for electrical connection to the main body of the device and supply of ink from the main body of the device.Replaceable chip type recording heads. Alternatively, the present invention is also effective when using a cartridge type recording head that is integrally provided with the recording head itself.

Further, it is preferable to add recovery means for the recording head, preliminary auxiliary means, etc., which are provided as a configuration of the recording apparatus, to the present invention, because the effects of the present invention can be further stabilized. Specifically, these include capping means for the recording head, cleaning means, pressure or suction means, preheating means using an electrothermal transducer or another heating element, or a combination thereof; It is also effective to perform a preliminary ejection mode in which ejection is performed separately from printing in order to perform stable printing.

In addition, regarding the type and number of recording heads installed, for example, in addition to one type that corresponds to single-color ink, there is also a plurality of recording heads that correspond to multiple inks with different recording colors and densities. It may be something that can be done.

In addition, the inkjet recording apparatus of the present invention may take the form of an image output terminal for information processing equipment such as a computer, a copying apparatus combined with a reader, etc., or a facsimile apparatus having a transmitting/receiving function. It can be anything.

[Effects of the Invention] As described above, according to the present invention, the arrangement direction of the ink ejection ports provided on the ejection surface of the recording head is within an angle range of 15° to 75° with respect to the relative movement direction. Since the ink ejection ports are set at an angle, it is possible to increase the distance between adjacent ink ejection ports compared to the conventional method, which prevents ink mist from interfering with the ink ejection ports, resulting in high-quality recording. Contribute to obtaining images.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing one embodiment of the present invention, FIG. 2 is an explanatory diagram showing an example of the recording operation by the recording head according to the present invention, and FIGS. 3 and 4 are respectively other embodiments of the present invention. FIG. 2 is an explanatory diagram showing a configuration example of a print head and its printing operation according to an example. 2.2A... Recording sheet, 7... Recording head, 9... Ink ejection ports, 9A, 9B, 9G... Ink ejection port array.

Claims (1)

[Scope of Claims] 1) It has a recording head in which a plurality of ink ejection orifices are arranged, and the recording material is applied to the recording material while either the recording head or the recording material is moved relative to the other. In an inkjet recording apparatus that performs recording by ejecting ink from the plurality of ink ejection ports toward the direction of the object, the arrangement direction of the ink ejection ports is tilted at an angle of 15° to 75° with respect to the relative movement direction. An inkjet recording device characterized in that it is installed.