JPS61280941A - Ink jet recorder - Google Patents

Abstract

PURPOSE:To keep intervals for portions of recording at proper values by eliminating the needs to adjust the interval between the discharging portion of ink droplets and a recording medium at each time on the whole recording face according to recording conditions by mounting a recording medium adsorber on a carriage on which a recording head is mounted. CONSTITUTION:Under a condition that a recording paper 1 is set on a given position, while scanning a carriage 7 to the main scanning direction, the paper 1 is sucked up by the electrostatic attraction of an electrostatic adsorbing plate 16 mounted on the carriage 7 and applied with a given electric field by DC voltage. In this case,since a tension is applied to the paper 1 by rollers 2, 3, and 6, under the condition that the tension is balanced with the attraction force of the plate 16, the interval between the ink droplets discharging portion of the recording head 8 and the paper 1 is kept constant. The interval between the ink droplets discharging portion and the paper 1 becomes greater when the plate 16 is moved to the direction of arrow 17 or 18 but becomes smaller when the plate 16 is moved to the directions of arrows 19 and 20.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to an inkjet that is equipped with an adjustment mechanism that adjusts the distance between a recording head that records information by ejecting ink droplets and a recording medium. It relates to a recording device.

[Summary of the Disclosure 1] This specification and drawings describe an inkjet recording device that records information by discharging ink droplets, and a carriage equipped with an inkjet recording head that discharges ink droplets toward a recording medium. This disclosure discloses a technique for maintaining the distance between the recording medium and the recording head to be approximately constant by providing maintenance means for maintaining the relative position of the recording medium and the inkjet recording head to be approximately constant.

Note that this summary is provided solely for the purpose of quickly accessing the technical content of the present invention, and does not have any influence on the technical scope of the present invention or the interpretation of rights.

[Prior Art] An example of a conventional inkjet recording device is shown in FIG.
In this figure, l is a recording paper as a recording medium, 2 is a paper feed roller that sandwiches the recording paper l with a rubber roller 3 and sends it in the sub-scanning direction, and 4 drives the paper feed roller and roller 6 via a belt 5. The paper feed pulse motor 57 is a carriage on which a recording pad 8 is mounted. The carriage 8 is driven by a head feed motor 11 via a wire 9 and a pulley lO, and is driven by a guide rail 12.1.
3 to reciprocate in the main scanning direction.

14 is an ink supply tube for supplying ink from an ink tank (not shown) to the recording pad 8; 15 is a flexible wiring board for supplying drive pulses to each nozzle of the recording pad 8; In this example, the recording head 8 is a multi-nozzle inkjet head, in which a plurality of nozzles are arranged linearly in the sub-scanning direction at an interval (pitch) of, for example, 18 layers, and the flexible wiring board 15
The nozzle is driven by a driving pulse supplied through the nozzle to eject ink droplets toward the recording paper l. Methods for ejecting this ink include, for example, a bubble jet method in which a heating element is embedded in the nozzle and ink droplets are ejected using bubbles generated by heat generated by pressure pulses, an air flow method using a piezoelectric element, and a diamond A diaphragm method using a plum, etc. is used.

In the conventional recording apparatus having the multi-nozzle radar 8 as described above, the distance from the tip of each nozzle lined up in the sub-scanning direction to the recording paper 1 is maintained constant during operation, and recording is performed from each nozzle. Since it is necessary to suppress variations in the time it takes the ink droplets to fly to the paper 1 as much as possible, it is necessary to maintain the flatness of the recording cap 1 over a fairly wide area corresponding to the printing width. On the other hand, in normal printers such as impact printers, printing is generally performed by placing the recording paper in close contact with a cylindrical platen, but if an inkjet multi-nozzle head is used for this contact printing method, each nozzle Since the distance to the recording paper that is in close contact with the platen changes continuously, when using such a multi-nozzle head, place the recording paper l on a flat surface facing the head as shown in Figure 4. It is necessary to support it properly.

In FIG. 4, the recording paper l is stretched by the paper feed roller 2 and the roller 6 to form a flat part of the recording paper in the part facing the head 8. As a means for supporting the recording paper 1, a fan is used to suck the recording paper 1 and attach it to a highly flat substrate placed on the back side of the recording paper.

On the other hand, in multi-nozzle heads, there are generally variations in the characteristics of individual nozzles, and in particular, the landing accuracy of drop left (small droplets) has a large effect on printing quality. This phenomenon occurs because the paper flies obliquely by an angle θ from the axial direction of the nozzle, and by making the drop left flight distance, that is, the distance between the recording paper and the nozzle tip as narrow as possible, the landing error due to the deviation of the angle θ can be reduced. The amount can be reduced.

[Problems to be Solved by the Invention] When performing general printing with this type of conventional device, the distance between the recording paper and the nozzle tip (hereinafter referred to as Δ distance) is 1.
~1.2 Proverb ■ is sufficient, but in order to obtain even higher quality images, the above-mentioned Δ interval should be set to 0.3~0. It becomes necessary to reduce the thickness to about the axial layer. However, when trying to maintain the flatness of the paper using the conventional holding means described above, the recording paper in the area where printing is performed absorbs ink and becomes undulating, causing the recording paper 1 to become wavy and uneven. Arise.

If the head tip comes into contact with the convex part of the recording paper and the ink at the head tip sticks to the recording paper, or if it is severe,
Since there is a risk that the recording paper may be broken by the tip of the head, it has not been possible to bring the nozzle head close to the recording paper and make the Δ interval 0.81- or less.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an inkjet recording apparatus that eliminates the above-mentioned drawbacks and outputs high-quality images.

[Means for Solving the Problems] In order to achieve the present object, one aspect of the present invention is to provide a carriage that is mounted with an inkjet recording head that ejects ink droplets toward the recording medium, and a relative position between the recording medium and the inkjet recording head. It is characterized by having a maintenance means for maintaining the position substantially constant.

[Operation] In the present invention, the maintenance means provided on the carriage on which the recording head is mounted maintains the relative position between the recording head and the recording medium 9 substantially constant during recording. This eliminates the need to adjust the distance between the recording head and the recording medium over the entire recording surface, and it is easy to maintain the distance at an appropriate value that allows a high-quality image to be obtained.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows the overall appearance of an embodiment of the present invention. In this figure, the same reference numerals as in the conventional device shown in FIG. 4 represent the same members. In FIG. This is an electrostatic adsorption plate that adsorbs the paper l, and is mounted on the head carriage 7 with its adsorption surface facing the recording paper l.

FIG. 2 shows a detailed arrangement of the recording paper 1, the recording head 8, and the electrostatic attraction plate 1B shown in FIG. Its length in the sub-scanning direction is 30×1. In addition, the electrostatic adsorption plate IB is arranged at an interval of 5 mm in the forward direction from the recording head 8 in the main scanning direction, and is arranged on the same surface as the recording head 8 in the ink droplet ejection direction. has been done. Furthermore, this electrostatic adsorption plate 18 has a displacement mechanism that can change its position by about ±5 cm in the main scanning direction and by about ±1 cm in the ink droplet ejection direction.

In the above configuration, when the recording paper 1 is set at a predetermined position, that is, when the leading edge of the recording paper in the feeding direction is sandwiched between the drive roller 2 and the rubber roller 3, the gear ridge 7 is moved in the main scanning direction. The recording paper 1 is attracted by the electrostatic attraction of the electrostatic attraction plate 1B mounted on the carriage 7 while scanning in the direction and applied with a predetermined electric field by a DC voltage. At this time, since tension is applied to the recording paper 1 by the rollers 2.3 and 6, in a state where this tension and the suction force of the electrostatic adsorption plate 16 are balanced, the ink droplet ejection part (nozzle) of the recording head 8 The distance from the recorder l is kept constant.

The distance between the ink droplet ejection part of the recording head 8 and the recording paper l is as follows.
This can be changed by adjusting the position of the electrostatic/electrostatic chuck plate 1B. That is, in the 254th stage, the electrostatic adsorption plate 1
Moving the electrostatic chuck plate 1B in the direction of arrow 17 or 18 in the figure increases the above-mentioned interval, and conversely moves the electrostatic adsorption plate 1B in the direction of arrow 19 in the figure.
．． When moving in the direction of 20, the above-mentioned interval becomes smaller.

In this way, when the recording paper l is attracted to the electrostatic adsorption plate 16, ink droplets are ejected from the rad 8 onto the recording mounted on the carriage 7 while scanning the carriage 7 in the main scanning direction, and onto the recording paper i. Records such as printing are performed.

FIG. 3 shows another embodiment of the present invention, and this embodiment is obtained by adding a guide member 21 having a guide surface extending along the paper feeding path of the recording paper l to the embodiment of FIG. be. An electrostatic attraction plate 22 is fixed on the guide member 21 so as to face the back surface of the recording paper 1 . In such a configuration, when the recording paper 1 is attracted by the electrostatic attraction plate 22, the roller 2.
The tension caused by 3 and B is obtained as an attractive force to the back surface of the recording paper l directly facing the electrostatic adsorption plate 1B.

Furthermore, by dividing the electrostatic adsorption plate 22 into a plurality of sections and sequentially electrically controlling each section, the electrostatic adsorption plate 22 is divided into a plurality of sections and each section is sequentially electrically controlled. It is also possible to charge only the suction plate 22.

In this embodiment, the electrostatic adsorption plates 18 and 22 using electrostatic action are excited as means for adsorbing the recording paper 1, but the present invention is not limited to this, and suction type adsorption plates using a vacuum pump, etc. Of course, it can also be applied.

[Effects of the Invention] As explained above, according to the present invention, a recording medium adsorption means for adsorbing a recording medium such as paper or various films is mounted on the carriage on which the inkjet recording head is mounted. It is no longer necessary to perform the troublesome work of adjusting the distance between the ink droplet ejection part of the recording head and the recording medium over the entire recording surface depending on the recording condition, and the above-mentioned interval in the area where printing etc. is recorded is eliminated. This has the effect of making it possible to ensure that the value is an appropriate value.

As a result, according to the present invention, the above-mentioned interval is always 0.3
It becomes possible to control the area below the intestines, and high-quality images can be easily obtained.

Furthermore, in the present invention, by disposing an electrostatic adsorption plate on the guide surface of the paper feeding path, it becomes possible to electrically control the value of the above-mentioned interval. However, it is possible to obtain a high-quality image by ensuring that the value of the interval is an appropriate value.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the appearance of an apparatus according to an embodiment of the present invention, and FIG. 2 is a plan view showing the main parts in detail. FIG. 3 is a partially cutaway perspective view showing another embodiment of the present invention, and FIG. 4 is a perspective view showing an example of the configuration of a conventional device. 1... Recording paper (recording medium). 2.3.8...Roller, 4.11...Motor, 7...Carriage, 8...Recording head. 18.22... Electrostatic adsorption plate. 21...Guiding member.

Claims (1)

[Claims] 1) A maintenance means for maintaining a relative position between the recording medium and the inkjet recording head at a substantially constant level is provided on a carriage on which an inkjet recording head that discharges ink droplets toward a recording medium is mounted. An inkjet recording device characterized by: 2) In the apparatus according to claim 1, the relative position of the recording medium is maintained substantially constant on a guide member having a guide surface that guides the recording medium along the conveyance path of the recording medium. An inkjet recording apparatus characterized by comprising a second maintenance means that performs maintenance. 3) An inkjet recording apparatus according to claim 1, wherein the maintenance means attracts and attracts the recording medium by electrostatic attraction or vacuum suction. 4) An inkjet recording apparatus according to claim 2, wherein the second maintenance means attracts and attracts the recording medium by electrostatic attraction or vacuum suction.