JPH0439076A - Ink jet printer - Google Patents

Abstract

PURPOSE:To form an accurate dot image by providing a record writing device which forms a dot image on a sheet of recording paper corresponding to input information, and recording paper movable press devices on both sides of the record writing device in the traveling direction of the record writing device. CONSTITUTION:A sheet of recording paper is inserted into a paper inlet 14 and sent toward a platen 12 along the surface of a paper guide 7 by a gate roller 8. Characters and images corresponding to information to be recorded are printed on the recording paper placed on the platen 12 as a carriage 2 having a head 1 travels. During writing, a tip 6a of a paper press lever 6, which is located in front of the carriage in the traveling direction, is pressed on the platen 12 at around the tip 1a of head 1 by energizing a solenoid 5. Therefore, the distance between the tip 1a of the head 1 and the printing surface is kept constant regardless of the deformed state of the recording paper, so that the flight of ink is stabilized and the information is written accurately.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an inkjet printer.

[Conventional technology]

Inkjet printers, which print by selectively ejecting ink from multiple nozzles, are superior to other printers in that they can record and write on plain paper without making noise and at low running costs. .

However, on the other hand, this type of printer ejects ink to form a dot image on the recording paper, so the recording paper may be deformed due to environmental changes or changes over time, and there are also problems in ensuring stability in writing the dot image. Normally, water-soluble ink is used, so if the recording paper absorbs water and becomes wavy due to recording and writing, and the flight distance of the ink changes partially, there is a problem that the image formation position will be largely shifted. have.

Of course, characters and figures written on recording paper are partially a.
It is normal for the color to be pale, and when the resolution is low and the dot diameter is large, it is often not visually noticeable.

[Problem to be Solved by the Invention 1] However, in a printer configured to print at high speed, such as a page printer, which has high resolution and a small dot diameter, the actual amount of deviation is not much different from the above case. Nevertheless, a problem arises in that it is recognized as if there is a large apparent deviation. Furthermore, the recording paper deformed due to the above-mentioned reason comes into contact with the ink ejection surface and the vicinity thereof, and the print result is disturbed due to rubbing with the undried ink area.

The present invention was made in view of these problems, and its purpose is to provide a new inkjet printer that enables reliable and accurate printing regardless of the pixel density to be recorded and the type of recording paper. It's about doing.

[Means for Solving the Problems] In other words, the present invention provides an inkjet printer for achieving the above-mentioned problems, and includes recording and writing means that ejects ink droplets to form a dot image on a recording paper medium according to input information. By providing recording paper movable pressing means disposed on both sides of the moving direction in the vicinity of the recording writing means, the ink flight distance due to deformation of the recording paper is kept at a constant distance, making it possible to form accurate dot images. It is something.

[Example] Therefore, the illustrated embodiment will be described below.

FIG. 1 shows an embodiment of the present invention, and FIGS. 2 and 3 show details of the main parts thereof.

This inkjet printer is broadly divided into a recording and writing section and a paper conveying section disposed in the recording and writing section.

The recording paper S, which is a recording medium inserted into the paper insertion slot 14, is
The paper is sent toward a platen 12, which is a printing section, by a gate roller 8 and a driven roller 9 connected to a drive force transmission mechanism (not shown). A gate roller 8 is provided on the lower side of the platen 12.
A paper feed roller 1O and a paper feed driven roller 11 are provided, which rotate at a constant speed, and eject the recording paper S to the downstream side.

Reference numeral 2 in the figure denotes a carriage that runs along two guide rails 3.4 suspended above the printing section so as to be perpendicular to the recording paper conveyance direction. Ink is applied to the recording paper S from two nozzles.
In addition to the inkjet head 1, which is a recording/writing means for ejecting ink upward, a paper presser lever 6 is provided to press down a portion of the recording paper S in front of the head 1 in the running direction.

That is, a pair of solenoids 5.5 are provided on both sides of the carriage 2, as shown in FIG. A pair of paper presser levers 6.6, which are recording medium movable pressing means that are swing-driven by 5.5, are pivotally supported, and the tip portion 6a of the paper presser lever 6, which is located forward in the traveling direction of the carriage 2, is lowered. At the same time, by alternately swinging in a seesaw manner to raise the tip of the paper presser lever 6 located at the rear in the running direction, the portion of the recording paper S in the front in the running direction is pressed against the platen 12 by the tip 6a of the m presser lever 6. It is configured to print while being pressed against the surface.

Next, the recording/writing operation of the above-mentioned apparatus will be explained.

The recording paper inserted from the paper insertion slot 14 is passed through the gate roller 8
The paper is sent toward the platen 12 on the paper guide 7.

As the cannage 2 on which the head 1 is disposed moves, characters, figures, etc. corresponding to the information to be recorded are written on the recording paper on the platen 12. At the time of writing, the tip 6 of the paper presser lever 6 in front of the carriage 2 in the traveling direction is
A is pressed against the surface of the platen 12 near the head tip 1a by energizing the solenoid 5. Therefore, the distance between the head tip and the printing surface is kept constant regardless of the deformation state of the paper, the flight distance of the ink is stabilized, and accurate information is written. Also, at this time, the paper presser lever tip 6a at the rear in the traveling direction of the carriage 2 is retracted to a position away from the paper by the spring force of the compression spring disposed at the tip because the solenoid 5 is not energized. .

When the writing operation is continued, the traveling direction of the carriage 2 is reversed after a certain amount of paper has been fed, but the operation of the paper presser lever 6 is similar to the above operation, with the lever in the traveling direction of the carriage 2. The recording paper is pressed against the surface of the platen 12, and the lever at the rear in the running direction is retracted to a position away from the paper.

Furthermore, since the above-mentioned operation suppresses the floating of the paper, it also has the effect of preventing stains due to contact with other structural members due to undried ink.

In FIG. 3, a roller 13 is provided at the tip of the paper presser lever 6, which can be rotated by friction with the recording paper.It operates in the same way as the lever described above, but the roller is provided. This reduces the frictional force between the lever and the paper, and reduces the running load on the carriage.

[Effects of the Invention] As described above, according to the present invention, since the inkjet printer is provided with a movable pressing means for pressing the recording medium near the recording writing means, pixels are formed on a part of the dot image to be written. Even if the recording medium is deformed due to large wetness due to a large density part, the distance between the recording/writing means and the recording medium can be kept constant and an accurate dot image can be formed. I can do it. -Can be dried. Moreover, writing can be performed without adversely affecting the written dot image.

[Brief explanation of drawings]

FIG. 1 is an overall view of an apparatus constituting an embodiment of the present invention, and FIGS. 2 and 3 are enlarged views showing essential parts of the same apparatus. Head carriage solenoid paper presser lever platen

Claims (2)

[Claims] (1) Recording and writing means for ejecting ink droplets to form a dot image on a recording medium according to input information, means for arranging and transporting the recording and writing means, and a means for disposing and transporting the recording and writing means at an appropriate position. a member disposed across the conveyance direction of the conveyance means; at least one recording medium movable pressing means disposed near the record writing means so as to press the recording medium against the member; An inkjet printer comprising a conveyance means for conveying a recording medium. (2) The inkjet printer according to claim 1, wherein a rotatable roller is disposed at the tip of the movable pressing means.