JPH0432436A - Recording medium conveyor device - Google Patents

Abstract

PURPOSE:To prevent the change of feeding quantity generated in association with the operating quantity of a recording medium conveyor means by changing the driving quantity of the conveyor means with the increase of its operating time during the conveyance of a recording medium. CONSTITUTION:Pulses outputted to a motor M from a motor driving circuit 521 are counted by a counter 522. The total time used for the conveying operation of a carrier roller is obtained from this count value. According to this operating time, the motor driving circuit 521 is driven/controlled by a control means 520 so as to change the driving quantity of the motor M. This change prevents the change of feeding quantity generated in association with the operating quantity of the carrier roller.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image recording apparatus, and more specifically to an image recording apparatus using a recording medium wound into a roll.

[Conventional Technique #i] Conventionally, this type of device has held an image recording medium (sheet) such as paper within the device or near the device.

The apparatus is provided with a conveyance path for guiding the recording medium to the image recording position and further to the ejection position. During zero image recording, the recording medium is guided along the conveyance path to the recording position of the apparatus, After recording the image, it is ejected from the device.

[Problem to be solved by the invention] However, in such devices, a method is widely used in which a pair of rollers is used as a means for conveying the recording medium, and the recording medium is held between the pair of rollers and the rollers are rotated to convey the recording medium. ing.

A high friction material such as rubber is used for the roller to prevent it from sliding relative to the recording medium.

However, in general, when rubber is used as a paper feed roller for a long time, the friction coefficient of the surface decreases, causing a slight relative movement between the recording medium and the roller surface, resulting in a decrease in the amount of paper feed. A drawback arises.

Such changes in the feed amount appear as image defects such as image expansion/contraction and image unevenness.

For example, in a device that records an image while the recording medium moves through an image recording section, changes in the amount of feed appear as expansion and contraction of the image.

That is, when the roller is new, the amount of feed is large, and the farther the roller is used, the longer the roller is used, the smaller the amount of feed is, and the slower the speed is, so when the roller is old, there is a drawback that the image may shrink.

In addition, in devices such as serial printers, which transport the recording medium to the recording position, stop, scan a certain recording width, then transport the recording medium by the recording width and repeat the recording again. The following inconveniences occur.

That is, the amount of feed of the recording medium after - times of recording scans differs depending on whether the roller is new or old. For this reason, for example, if you adjust the feed amount to match when the roller is new, after the roller has been used for a long time, the feed amount of the recording medium fed after one recording scan will become smaller, and the feed amount may be less than the predetermined amount. This causes image unevenness.

FIG. 7 is an explanatory diagram of an image for explaining the conventional drawbacks. (1) shows the image A recorded on the recording medium when the image is fed by the normal feed amount. The recording width is T, and the feed amount and recording width match Il. The recording medium conveyance direction is indicated by an arrow PD.

(2) shows image A' when the feed amount is small. As shown in the figure, since the feed amount T' of the image A' is small with respect to the recording width T, an overlap t of images occurs at the end of the recording width, and this image becomes unsightly.

In addition, (3) indicates the case where the feed amount is too large, and the image A
As shown in the figure, since the feed amount T' is larger than the recording width, an image gap t' occurs at the edge of the recording width, resulting in an unsightly image.

Recently, image recording devices have been able to record four Victorian color images.
High-definition output devices of 00 dots/1 nch or more have been developed, and it is known that these recording devices produce unsightly images unless the above-mentioned image type t and image gap t' are kept below several tens of pm. ing.

However, there has not been a device that can correct the difference in feed amount between old and new rollers as described above.

As a way to prevent friction from decreasing due to durability, there are methods that do not use soft rollers such as rubber, but instead use sand gel-last treated metal roller surfaces or rollers with composite plating, but such rollers are expensive. Therefore, the cost of the device increases.

[Means and effects for solving the problems] The present invention has been made in view of the above points, and includes changing the driving amount of the conveying means according to the usage time of the recording medium conveying means when conveying the recording medium. By changing the driving amount, the change in the feed amount described in the conventional example is prevented.

[Examples] The present invention will be described below based on examples shown in the drawings. Second
The figure is a side sectional view of an image recording apparatus to which the present invention is applied.

Referring to FIG. 2, C8 is a cut sheet-shaped recording medium (for example, cut-shaped recording paper, etc.), which is stacked on the cassette 7. RP is a roll-shaped recording medium, and is rotatable around a rotation axis RPA. PC, PR and PI are cut sheet C3 and roll paper PR, respectively.
and a conveyance path for the recording medium inserted into the manual feed port 9, which merge near the gripping position of the conveyance rollers 301.

A cut sheet C5 separated from the cassette 7 is introduced into the conveyance path PC by the cooperation of the pickup roller 3]1 and a separation member (not shown) such as a separation claw, and the cut sheet C8 is introduced into the conveyance path PC by the rollers 316 provided on the path. , 315 and 314 while being guided on the conveyance path PC.
Led by the old, W! The feed path PR includes a set roller 324 for pulling out the recording medium from the roll portion and introducing it onto the path, a roller 325 for conveying the recording medium on the path toward the conveyance roller 301, and a roll paper RP of a predetermined size. A cutter 326 is provided for cutting. Further, 321 is a holder that holds the roll paper RP.

The recording medium introduced into the conveyance roller 301 via each path PC, PR or PI is transferred to a platen 40 such as a registration roller.
Lower conveyance roller 33 on the upstream side on the conveyance path P near 1
1 to the platen 401, and is further conveyed onto the conveyance path P by being held by an upper conveyance roller 341 on the downstream side near the platen 40 on the conveyance path P. During this process, the recording head 101 performs recording. and is discharged to the outside from the discharge port 11. An inkjet recording section 100, which is an image recording means, is arranged opposite the platen 401. The head holder 101 has an ink sheet head 1.
02 is fixed. The head holder 101 is fixed to the recording unit transport system 200. 201 is head holder 1
01 in a direction perpendicular to the plane of the drawing, and the carriage 201 moves along a rail 221.

During image recording, the recording medium P is held on the platen 401 in a stopped state, and while the carriage 201 is moved, ink is ejected from the inkjet head 102 toward the recording medium P according to the image signal, thereby recording the image on the recording section T. is recorded on the recording medium P. Thereafter, the upper conveyance roller 341 is driven to convey the recording medium P by the length of the recording section T and then stop. After that, the image on the recording section T is recorded again. Repeat this,
An image is recorded on a recording medium P.

The operation of the apparatus configured as above will be explained using FIG. 1.

The motor M is connected to a motor drive circuit 521, and the motor drive circuit 521 is roughly connected to a control circuit 520.

The motor M is a stepping motor, and the rotation angle is determined according to the number of pulses of the pulse signal from the motor drive circuit 521. Since the motor M drives the lower transport rollers 341 and 331 as shown in FIG. 3, the amount of feed of the recording medium can be changed according to the number of pulses output to the motor M from the motor drive circuit 521. .

That is, if the number of pulses output from the motor drive circuit 521 to the motor M is increased, the amount of feed of the recording medium P will also be increased.
If the number of pulses is reduced, the amount of feed of the recording medium P is also reduced.

Pulses output from the motor drive circuit 521 to the motor M are counted by a pulse counter 522. Since this count value corresponds to the rotation angle of the motor M, the total time used for conveyance by the conveyance rollers 331, 341 can be determined from this count value.

According to experiments, when a recording medium equivalent to several thousand meters was conveyed, the frictional force on the surface of the conveyance rollers 331, 341 decreased to such an extent that it affected the conveyance. Therefore, in this embodiment, when the pulse count value of the counter 522 reaches the number of thousands to equivalent to the number of meters conveyed, the control circuit 522
0 sends a pulse number increase signal to the motor drive circuit 521, and thereafter the motor M is driven by more angles than before.

FIG. 4 is a diagram showing the relationship between the usage time and the number of pulses.

The number of pulses is gradually increased as the usage time becomes longer and the feed amount of the conveying roller decreases.

By operating as described above, it is possible to increase the rotation angle of the upper and lower conveyance rollers 331 and 341, which are driven to convey the recording medium P, in accordance with the degree to which the conveyance roller feed amount decreases. As a result, it is possible to control the feed amount so that it does not change.

This makes it possible to prevent the change in feed amount as described in the prior art example.

[Other Embodiments] A second embodiment of the present invention will be described with reference to FIGS. 5 and 6.

Figure 5 is a perspective view of the vicinity of the platen! Figure s6 is a block diagram of the second embodiment.

In FIG. 5, a rotary encoder EN is connected coaxially with the upper conveyance roller 341. The rotary encoder EN detects the rotation angle of the upper conveyance roller 341. The output signal of the rotary encoder EN is input to the control circuit 520 as shown in diagram s6. The pulse length counter 522 counts the cumulative number of feed pulses of the motor M. This count value is the number of thousands of recording media conveyed.
When the drinking meter equivalent is reached, the control circuit 520 sends a signal to the motor drive circuit 521. The motor M is a pulse motor as in the first embodiment, and the motor drive circuit 521
The number of pulses from is increased and the motor M is driven through more angles than before. The upper conveyance roller 341 is rotated by the driving force from the motor M, and the rotation angle is detected by the rotary encoder EN. This detected amount is sent to the control circuit 520, and the control circuit 520 determines whether the rotation angle is appropriate. If the 0 rotation angle is not appropriate, the control circuit 520 further sends a signal to the motor drive circuit 521 to control the motor. Rotate M by a predetermined angle.

In this way, this embodiment performs closed loop control.

By using the above-described control, it is possible to prevent the change in the feed amount of the recording medium P described in the conventional example with even higher precision.

[Effects of the Invention] As described above, by using the present invention, it has become possible to prevent changes in the feed amount due to the amount of use of the recording medium conveying means.

Therefore, all the drawbacks mentioned in the conventional example can be eliminated.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the present invention. FIG. 2 is a side sectional view of an image recording apparatus to which the present invention is applied. FIG. 3 is a perspective view of the vicinity of the platen of an embodiment of the present invention. A graph showing the relationship between the number of applied pulses and the usage time. FIG. 5 is a perspective view of the vicinity of the roll-shaped recording medium of the second embodiment. Fig. 6 is a block diagram of the ls2 embodiment Fig. 7 shows image defects of the conventional example Fig. 520 shows the control circuit 521, the motor drive circuit 522, the pulse counter M

Claims (2)

[Claims] (1) In a recording device that includes a conveying means for conveying the recording medium so that the recording medium moves past the recording position, and a control means for controlling the drive amount of the conveying means, an increase in the usage time of the conveying means when conveying the recording medium. 1. A recording medium conveying device characterized in that a driving amount of a conveying means is changed by a control means in accordance with the change in the driving amount of the conveying means. (2) The recording medium transport device according to claim 1, wherein the driving amount is controlled to be small when the cumulative usage time of the transporting means is short, and the driving amount is controlled to be increased when the cumulative usage time is long.