JPH02273272A - Image recording device - Google Patents

Abstract

PURPOSE:To prevent deterioration of an image quality if a recording paper is transported only by a traction feed system with a tension maintained at an image recording section by setting the feed amount of the traction feed system at a recording length +- a pixel pitch for a recording length after the paper comes out of a roller. CONSTITUTION:A recording paper 5 is fed onto a platen plate 2 by a pair of fixed quantity feed rollers 1, 1', then it is given tension by tension rollers 3, 3' which sandwich the paper. As a result the paper sticks to the surface of a platen plate 2 tightly. The record-, ing paper 5 stops, then an ink jet head 4 moves and an image is recorded on the paper fed by a fixed width. Next, the fixed quantity feed rollers 1, 1' feed the paper 5 to an image recording section by a fixed feed amount. Then the new part recording material 5 is positioned on the platen plate 2. Even after the rear end of the recording material 5 passes through the fixed amount feed roller 1,1' completely, the tension rollers 3, 3' are driven under the same drive state to transport the paper 5 to the surface of a platen. Thus it is possible to record an image up to the rear end of the paper 5.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image recording apparatus that records an image while applying tension to recording paper.

[Prior Art] Conventionally, this type of image recording apparatus uses suction means or electrostatic adsorption to move the recording paper onto a platen in order to prevent the recording paper from floating or bending in the image recording section. It was customary to have it in close contact with the

[Problem that the invention seeks to solve] However,
In the above conventional example, for the simple act of bringing the recording paper of the image recording unit into close contact with the platen, it is necessary to provide a suction means or a high-voltage i source for electrostatic adsorption, and the image recording device 1 itself was made with a lot of work, making it extremely expensive.

Therefore, as a means to more easily bring the recording paper into close contact with the platen, a pair of tension rollers is installed in the image recording unit to create tension on the recording paper, in contrast to the roller that feeds the recording paper at a constant rate or at a constant speed. There are ways to set it up, but
The feeding of the recording paper is maintained constant while tension is applied to the recording paper being held between fixed-rate or constant-speed feed rollers, and image recording is performed clearly and without unevenness in the image recording section. After the trailing edge of the recording paper passes through the metering feed roller, it is transported by a tension roller system.
The feeding amount of the recording paper increases, leaving a margin at the seam of the image and causing image blurring. There is also a method of stopping image recording before the paper leaves the fixed-rate or constant-speed feed roller and ejecting the remaining paper with a margin, but this leaves a large margin at the trailing edge of the recording paper.
This results in large image defects compared to the original.

Means (and operation) for solving problem U] According to the present invention, in an image recording apparatus having a fixed-rate or constant-speed feed roller, the feed amount of the tension feed means is adjusted to the recording distance after passing through the roller. On the other hand, by setting the recording distance to a ten-pixel pitch, the image quality is prevented from deteriorating even when conveyed only by the tension system while maintaining the tension that suppresses the lifting and bending of the recording paper in the image recording section. be.

[Embodiment 1] Hereinafter, embodiments of the present invention will be described by taking as an example a so-called serial scan recording apparatus in which an image recording apparatus reciprocates on a recording paper and records images in predetermined width increments.

FIG. 1 is a drawing that best represents the features of the present invention, and shows a pair of quantitative feed rollers 1 and 1' for feeding the recording paper 5 in a constant amount.
is driven by a drive source (not shown) to feed the paper 5 onto the platen plate 2, which is the image recording section, and furthermore, a pair of tension rollers 3, 3' as the tension means of the present invention.
The structure is such that the recording paper 5 is held between the recording paper 5 and the recording paper 5 and tension is applied to the recording paper 5 so that the recording paper 5 is brought into close contact with the platen plate 2. When the recording paper 5 is in a two-way state, the drive shaft J of the drive source (not shown) stops and the upper part of the recording paper 5 on the platen plate 2 is moved toward the ink sheet head 4 of the image recording device in the direction of the arrow. It moves and records images of fixed feed width. Next, a pair of metering feed rollers 1.1' feed the recording paper 5 by a metered amount to the image recording section, and a new portion of the recording material 5 is set on the platen plate 2. The above-mentioned operation is repeated many times in the longitudinal direction of the recording material 5 to form an image. After the trailing edge of the recording material 5 has passed through the pair of quantitative feed rollers 1.1', the pair of tension rollers 3.3' are driven in the same driving condition to convey the recording paper 5 onto the platen and transport the recording paper 5 onto the platen. It is possible to record images up to the rear end of 5.

Next, the feeding amount of the recording paper 5 by the tensioning means of the present invention will be described. The feeding amount of the tension type recording paper 5 must be much sharper than the fixed feeding amount of the pair of metering feed rollers 1 and 1', since it is necessary to apply tension to the recording paper 5 on the platen plate 2. And this amount of too much feeding is 5 sheets of recording paper.
When tension is applied to , the slippage between the paper 5 and the pair of tension rollers 3.3' is eliminated.

In the present invention, the recording paper is fed by an amount equal to or less than one pixel pitch to the image recording apparatus after the trailing edge of the recording paper has passed through the pair of quantitative feed rollers 1.1'.

For example, when an inkjet head 4 is used as in this embodiment, the inkjet head is generally 180 or 30 mm.
24-1 at pixel density of 0dot per 1nch
It has about 28 nozzles, a pixel pitch of 141 μm, and a pixel pitch of 85.
um, 3.387 mm to 10.837 mm during recording.

Therefore, 300 dots per fnchlo
, 837, the feed amount of the pair of tension rollers is: feed amount=I0.837 (image recording section rs>+0085
The following (pixel pitch) will be set.

Naturally, the image record 2j archive 1 is not limited to the recording of the head.

In this embodiment, the tension means can be set to the value of this feed port by changing the diameter of the driving roller 3 that applies a conveying force to the recording material 5 of the pair of tension rollers 3° 3'. It is.

By setting the feed amount of the tensioning means in this manner, even after the recording material 5 has passed through the pair of quantitative feed rollers 1.1', the recording material 5 will continue to move according to the feed amount of the pair of tension rollers 3°3'. Even at the joint part of the image, there is no joint unevenness of one pixel pitch or less, it is possible to record up to the rear end of the recording material 5 without degrading the image quality, and it is sufficient as a tensioning means. can also maintain tension.

In this embodiment, an inkjet head is disclosed as an image recording device, but the present invention can of course be applied to any image recording device that requires quantitative feeding, such as a dot printer. Next, it will be shown that the present invention can also be applied to image recording apparatuses that have an image recording means of approximately the same width as the width of the recording paper, such as a multi-nozzle inkjet head in the width direction of the recording paper, a thermal head, etc., in addition to the above-mentioned serial printer. .

FIG. 2 shows an image recording section of an image recording apparatus provided with a multi-nozzle inkjet head 6 in the recording paper width direction as an image recording means. The recording paper 5 is transported to the platen plate 2 by a pair of constant speed feed rollers 7.7' that transport the recording paper 5 at a constant speed.
It is conveyed upward and is held between a pair of bow tension rollers 3.3'.
Tensicon is added. Image formation is performed by simultaneously ejecting droplets from the multi-nozzle inkjet head 6 in the width direction of the recording paper, and performing the next ejection when the recording paper moves and moves by one pixel pitch.

And the recording paper? &The end is a pair of constant speed feed rollers 7.7'
After passing through, as in the embodiment described above, a pair of tension rollers
．． It follows the transportability of 3'. Furthermore, by setting the feed amount of the tension roller in the same manner as described above, it is possible to record up to the trailing edge of the recording material without degrading the image quality.

C. Effects of the Invention As explained above, the feed amount of the tensioning means of the image recording device that feeds the recording paper using a fixed-rate or constant-speed feed roller is adjusted to By setting the pixel pitch to less than the pixel pitch, it is possible to perform recording to the trailing edge of the recording paper without degrading the image quality without impairing the tensile effect of the recording paper.

[Brief explanation of drawings]

FIG. 1 is a perspective view of the vicinity of an image recording section including a pair of tension rollers according to the present invention. FIG. 2 is a perspective view of the vicinity of an image recording section of another embodiment of the present invention. The bow 1 is the long bow roller 4 is the inkjet head 6 is the recording paper width direction multiple inkjet head 7 is the constant speed feeding roller

Claims (1)

[Claims] In an image recording apparatus having a roller that feeds the recording paper at a constant rate or at a constant speed, an image recording section, and a tension feeding means that applies tension to the recording paper, the recording distance after the recording paper passes through the roller is An image recording device characterized in that the feeding distance of the tension feeding means is set to be equal to or less than the recording distance + - pixel pitch.