JP2010208793A - Curl correction device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a curl correction device capable of making a constant and uniform curl correction on the recording paper whole surface. <P>SOLUTION: This curl correction device has a curl correction action force changing means capable of optionally changing curl correction action force by correcting a curl of carried paper, a paper carrying speed recognizing means for recognizing a paper carrying speed being a carrying speed of paper changed in the curl correction action force by the curl correction action force changing means, and a first control means for controlling strength of the curl correction action force of the curl correction action force changing means in response to the paper carrying speed recognized by the paper carrying speed recognizing means. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image forming apparatus, and more particularly to a curl correction apparatus that corrects curl of a recording sheet provided inside or outside the image forming apparatus.

  Recording paper used in image forming apparatuses such as facsimiles and printers is affected by the influence of the paper state and stacking state before image formation, and the structure of the transport path when transported in the image forming apparatus. Influenced by recording materials and recording methods during image recording. Then, a phenomenon in which the shape of the recording paper is warped or rounded, and the shape generated on the recording paper is generally called curl. When curling occurs on the recording paper, the recording paper is clogged on the conveyance path in the image forming apparatus, causing a mechanical failure. The image quality is deteriorated due to interference with the recording member, or the recording paper is loaded after recording the image. There are many problems, such as a decrease in performance.

  In order to improve this problem, conventionally, when correcting the curl generated on the recording paper, a method of correcting the curl by pressing the recording paper with a pressing roller when conveying the recording paper with a belt is known. Yes.

  In addition, a method of performing curl correction by pressing down and pressing a roller located at the center when a recording sheet is conveyed by three rollers is known (see, for example, Patent Document 1). In any case, when correcting the curl generated on the recording paper, the curl is corrected by pressing a member on the opposite side to the curl direction.

JP 11-189363 A

  However, in the above-described prior art, it is not possible to sufficiently achieve constant and uniform curl correction on the entire surface of the recording paper in correcting the curling of the recording paper in an image forming apparatus such as a facsimile or a printer. Since the conveyance speed of the recording paper at the time of image recording in the image forming apparatus varies depending on image recording conditions and the like, if the conveyance speed increases, the curl correction effect may not be sufficiently obtained. On the other hand, if the conveyance speed is too low, curl correction may be too effective.

  Further, depending on the configuration of the image recording apparatus, the conveyance speed at the time of image recording is not always constant. For example, in an ink jet printer, there is a problem that curl correction unevenness occurs in an image recording apparatus in which the conveyance of the recording paper in the sub-scanning direction stops while the ink jet print head moves in the main scanning direction. That is, since intermittent conveyance that repeats short conveyance and stop occurs, there is a problem that uniform and uniform curl correction cannot be realized and curl correction unevenness occurs.

  In other words, the above conventional example has a problem that it is not possible to perform constant and uniform curl correction on the entire surface of the recording paper.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a curl correction apparatus that can perform a constant and uniform curl correction on the entire surface of a recording sheet.

  According to the present invention, the curl correction acting force changing means capable of correcting the curl of the conveyed paper and arbitrarily changing the curl correcting action force, and the curl correcting action force is changed by the curl correcting action force changing means. According to the paper conveyance speed recognition means for recognizing the paper conveyance speed, which is the paper conveyance speed, and the paper conveyance speed recognized by the paper conveyance speed recognition means, the strength of the curl correction action force of the curl correction action force change means is determined. A curl correction device having first control means for controlling.

  According to the present invention, a constant and uniform curl correction can be performed on the entire surface of the recording paper, a mechanical failure of the image forming apparatus can be avoided, the recording quality on the recording paper can be improved, and the recording paper There is an effect that the loadability can be improved.

1 is a schematic perspective view of an image forming apparatus PR1 that is Embodiment 1 of the present invention. It is a schematic block diagram of the control system in image forming apparatus PR1. It is a perspective view which shows the outline of image forming apparatus PR2 which is Example 2 of this invention. It is a figure which shows image forming apparatus PR2 which is Example 2 of this invention.

  The mode for carrying out the invention is the following embodiment.

  FIG. 1 is a schematic perspective view of an image forming apparatus PR1 that is Embodiment 1 of the present invention.

  FIG. 2 is a schematic configuration diagram of a control system in the image forming apparatus PR1.

  The image forming apparatus PR1 includes a serial scan type inkjet printer 200 and a curl correction apparatus 300 that operates in conjunction with the inkjet printer 200. Further, roll paper R is used as a recording paper medium to be used, and roll paper R that is conveyed by the ink jet printer 200 is subjected to curl correction processing unique to the roll paper on the entire surface of the roll paper R. Perform uniformly and uniformly.

  The image forming apparatus PR1 includes an inkjet print head H, a main scanning belt B, pulleys Pa and Pb, main scanning motors M1, M2, and M3, conveyance rollers R1a and R1b, a curl correction roller R2, and a curl correction action. It has a force adjusting roller R3 and a shaft S. The main scanning motor M1 is located below the main scanning motor M2 in FIG.

  The ink jet print head H has a plurality of ejection openings. The main scanning belt B is a belt for reciprocating the ink jet print head H along the shaft S. The pulleys Pa and Pb rotate the main scanning belt B. The main scanning motor M1 rotates the pulley Pa.

  The conveyance roller R1a conveys the roll paper R while being held together with the conveyance roller R1b by the motor M2. The curl correction action force adjustment roller R3 suppresses the roll paper R by the motor M3, changes the angle at which the roll paper R is wound around the curl correction roller R2 to a constant angle, and gives the curl correction action force of the roll paper R.

  Next, a schematic configuration of a control system in the image forming apparatus PR1 shown in FIG. 2 will be described.

  The ink jet printer 200 performs print processing based on print data received from the host computer 100. The I / F 201 communicates with the host computer 100 and receives print data.

  The print control unit 202 analyzes the received print data, determines ink discharge conditions by the inkjet print head H from the print mode, paper size, type, drying time, other print conditions, and the like, and the discharge unit 203 discharges the ink. Take control. Further, the print control unit 202 determines a head driving condition for moving the ink jet print head H in the main scanning direction by the head driving unit 204, and the transport driving unit 205 transports the roll paper R. Determine the transport conditions.

  The curl correction apparatus 300 corrects curl specific to the roll paper R with respect to the roll paper R conveyed according to the printing control of the inkjet printer 200.

  The paper transport speed recognition unit 302 can recognize the transport speed of the roll paper R based on the print mode, paper size, type, drying time, other printing conditions, etc. analyzed by the print control unit 202 of the inkjet printer 200. . Further, the paper transport speed recognition unit 302 directly recognizes the transport speed from the transport control signal from the transport driving unit 205, and recognizes the transport speed value obtained by the transport speed sensor 304 that measures the transport speed of the roll paper R. Is possible.

  According to the conveyance speed of the roll paper R recognized by the paper conveyance speed recognition unit 302, the curl of the roll paper R is corrected in a direction opposite to the curl direction so as to correct the curl of the roll paper R uniformly and uniformly. The roll paper R is wound around the curl correction roller R2, and adjustment control of the winding angle is performed. When the adjustment of the winding angle is controlled, the curling correction acting force adjustment roller R3 changes the amount of restraining of the roll paper R, and the driving means 303 adjusts the position of the curling correction acting force adjustment roller R3. Adjust the amount.

  The curl correction action force control means 301 is an example of a curl correction action force change means capable of correcting the curl of the conveyed paper and arbitrarily changing the curl correction action force. The paper conveyance speed recognition means 302 is an example of a paper conveyance speed recognition means for recognizing a paper conveyance speed that is a paper conveyance speed whose curl correction action force has been changed by the curl correction action force change means.

  The curl correction action force control means 301 is an example of a first control means for controlling the strength of the curl correction action force of the curl correction action force change means in accordance with the paper conveyance speed recognized by the paper conveyance speed recognition means. is there.

  The print control unit 202 is an example of a sheet conveyance speed determining unit that determines a sheet conveyance speed that is the sheet conveyance speed, and is an example of a sheet conveyance speed control unit that controls the sheet conveyance speed. The paper conveyance speed recognition means is means for recognizing a paper conveyance speed by an ink jet printer provided outside the curl correction apparatus. The paper transport speed determining means is means for determining the paper transport speed by the paper transport driving means in accordance with the recognized paper transport speed. The curl correction action force changing means is a means for changing the curl correction action force based on the paper conveyance speed recognized by the paper conveyance speed recognition means.

  The paper transport speed recognizing means is means for detecting the paper transport speed of the transported paper and recognizing the paper transport speed. Further, the paper transport speed recognition means is means for recognizing the paper transport speed based on the printing conditions of the printing apparatus.

  FIG. 3 is a perspective view schematically showing an image forming apparatus PR2 that is Embodiment 2 of the present invention. In the first embodiment, there is a possibility that the influence of intermittent feeding cannot be removed due to the temporary stop of the conveyance of the roll paper R when the ink jet print head H reciprocates in the main scanning direction peculiar to the ink jet printer.

  In the image forming apparatus PR2, the curl correction apparatus is provided with a transport unit for forming the buffer loop L so as not to be affected by the transport process of the ink jet printer, and the limited space of the buffer loop L is effectively used. The loop increase / decrease detecting means is provided.

  The transport roller R4 and the buffer loop L are means for avoiding the influence of curl correction processing that continuously occurs when the inkjet print head H moves in the main scanning direction. That is, the transport roller R4 and the buffer loop L are means for avoiding the influence of the curl correction process by intermittently feeding the roll paper R of the transport rollers R1a and R1b.

  The transport roller R4 performs transport processing using the motor M4, and at the same time, the buffer loop L forms a space of the buffer loop L for absorbing a transport difference between the transport rollers R1a and R1b and the transport roller R4. That is, the buffer loop L is a loop that absorbs the difference in the conveyance speed between the two paper conveyance rollers. For example, when the recording conveyance process is stopped by the conveyance rollers R1a and R1b, the conveyance is controlled in the direction of decreasing the conveyance speed without stopping the conveyance by the conveyance roller R4. The roll paper R excessively conveyed by the conveyance roller R4 is absorbed by the buffer loop L, and the conveyance is controlled by the conveyance roller R4. In parallel with this, the curl correction roller R2 and the curl correction action force adjustment roller R3 Adjust the curl correction force. Thereby, the curl correction on the roll paper R is kept constant and uniform.

  Further, the position of the buffer loop roller R5 for detecting increase / decrease in the loop amount in the buffer loop L is detected. For this purpose, the encoder E detects an increase / decrease in the buffer loop amount, and the conveyance roller R4 controls the conveyance with respect to the detected buffer loop increase / decrease amount, thereby effectively utilizing the limited space of the buffer loop L. To do.

  FIG. 4 is a diagram illustrating an image forming apparatus PR2 that is Embodiment 2 of the present invention. The image forming apparatus PR2 includes a host computer 100, an ink jet printer 200, and a curl correction apparatus 300a. The control contents related to the host computer 100, the inkjet printer 200, and the roll paper R are the same as the control contents in the first embodiment.

  The curl correction apparatus 300a that is a feature of the second embodiment will be described. The transport roller R4 transports the roll paper R using the driving unit 305. The space of the buffer loop L is between Lh indicating the buffer loop amount 0% and Ll indicating the buffer loop amount 100%, and the transport rollers R1a and R1b on the ink jet printer 200 side and the transport roller R4 on the curl correction device side. Absorbs the transport amount difference that occurs between

  The loop increase / decrease detection means 306 detects the loop increase / decrease amount based on the position of the roll paper R in the buffer loop L space using the buffer loop roller R5. The loop increase / decrease amount is an increase / decrease amount with respect to the reference position Lp determined at a fixed position in the buffer loop L space so as to be within the buffer loop L space. Based on the loop increase / decrease amount detected by the loop increase / decrease detection unit 306, the sheet conveyance speed difference recognition unit 308 recognizes the conveyance speed difference between the conveyance rollers R1a and R1b and the conveyance roller R4.

  The simultaneous and parallel control unit 307 controls the conveyance speed of the conveyance roller R4 by the driving unit 305 based on the detected conveyance speed difference so that the roll paper R is positioned at the reference position Lp. At the same time, the conveyance speed of the conveyance roller R4 is transmitted to the sheet conveyance speed recognition means 302 in order to control the curl correction acting force. The curl is opposite to the curl direction so as to correct the curl of the roll paper R uniformly and uniformly with respect to the transport speed of the roll paper R recognized by the paper transport speed recognition unit 302. The winding angle is adjusted and controlled so that the roll paper R is wound around the correction roller R2. When adjusting and controlling the winding angle, the driving unit 303 adjusts the position of the curl correction acting force adjustment roller R3, thereby adjusting the amount of the roll paper R to be suppressed.

  The above embodiment is based on the fact that the conveyance speed and the curl correcting force react linearly. Therefore, depending on the mechanical control accuracy of the curl correction acting force of the curl correction device, if it reacts linearly to the conveyance speed, it cannot cope with fine changes in the conveyance speed, etc. In some cases, curl correction cannot be performed.

  The conveyance speed performance in the above embodiment can be controlled in units of 1 mm / sec between 0 and 100 mm / sec. For an apparatus that does not provide the mechanical control accuracy of the curl correction action force, the variable control of the curl correction action force with respect to the sheet conveyance speed is not performed in units of 1 mm / sec. That is, curl correction is performed from as much as possible as much as possible to remove curl from the roll paper R as uniformly as possible.

  According to the above-described embodiment, the curl correcting force is controlled according to the conveyance speed of the roll paper R, so that the optimal curl correction according to the speed is possible. In addition, according to the above embodiment, the simultaneous and simultaneous control of the conveyance speed and the curl correcting force is performed, so that the curl correction is performed while adjusting the difference between the conveyance speed of the conveyance apparatus that operates in conjunction with the curl correction apparatus. It can be performed. Furthermore, according to the above embodiment, by combining the loop buffer conveyance control, it is possible to absorb the difference in conveyance speed with the conveyance device that operates in conjunction with the curl correction device, and simultaneously perform the curl correction processing. By these controls, a constant and uniform curl correction can always be performed on the entire surface of the roll paper R. As a result, a mechanical failure due to a jam of the roll paper R inside the image forming apparatus can be avoided, the recording quality on the roll paper R can be improved, and the loadability of the roll paper R can be improved. .

  The drive unit 305 and the transport roller R4 are buffer loop forming units that form a buffer loop that absorbs a difference in transport speed between the two paper transport rollers between the curl correction apparatus and the printing apparatus. It is an example.

  The paper conveyance speed difference recognition unit 308 is an example of a speed difference recognition unit that recognizes a difference between a paper conveyance speed in the curl correction apparatus and a paper conveyance speed in the printing apparatus.

  The simultaneous parallel control unit 307 controls the conveyance speed in the curl correction device so that the speed difference recognized by the speed difference recognition unit is absorbed by the buffer loop forming unit, and the speed difference falls within a certain range. Then, it is an example of the second control means for controlling the curl correction acting force.

  The loop increase / decrease detecting means 306 is an example of a buffer loop amount increase / decrease detecting means for detecting the buffer loop increase / decrease amount by the buffer loop forming means.

  The simultaneous and parallel control unit 307 controls the conveyance speed in the curl correction device so as to keep the buffer loop amount constant according to the buffer loop increase / decrease amount detected by the buffer loop amount increase / decrease detection unit. It is an example of the 3rd control means which controls correction action force.

  The simultaneous and parallel control means 307 controls the curl correction acting force when the conveyance speed exceeds a certain value when carrying out the conveyance speed control and the curl correction acting force control in the curl correcting device in parallel. 4 is an example of four control means.

  The present invention is not limited to an image forming apparatus, and can be provided for a medium conveying apparatus in which curling (warping) occurs even when the steady state is a flat surface.

R2 ... curl correction roller,
R3: Curling correction force adjusting roller,
R5: Buffer loop roller,
L ... Buffer loop,
301: Curling correction action force control means.

Claims (7)

Curl correction action force changing means for correcting curl of the conveyed paper and arbitrarily changing the curl correction action force;
Paper conveyance speed recognition means for recognizing a paper conveyance speed that is a conveyance speed of the paper whose curl correction action force has been changed by the curl correction action force change means;
First control means for controlling the strength of the curl correcting action force of the curl correcting action force changing means in accordance with the paper transport speed recognized by the paper transport speed recognizing means;
A curl straightening device comprising: Claim 1 wherein
Paper transport speed determining means for determining a paper transport speed, which is the paper transport speed;
Paper transport speed control means for controlling the paper transport speed;
And the paper conveyance speed recognition means is means for recognizing a paper conveyance speed by an ink jet printer provided outside the curl correction device,
The paper transport speed determining means is means for determining the paper transport speed by the paper transport driving means according to the recognized paper transport speed,
The curl correcting device, wherein the curl correcting action force changing means is a means for changing the curl correcting action force based on the paper transport speed recognized by the paper transport speed recognizing means. Claim 1 or claim 2, wherein
The curl correction apparatus, wherein the paper transport speed recognition means is means for detecting a paper transport speed by a sensor and recognizing the paper transport speed. Claim 1 or claim 2, wherein
The curl correction device, wherein the paper transport speed recognition means is means for recognizing a paper transport speed based on a printing condition of the printing apparatus. It is at least 1 of Claim 2 thru | or 4, Comprising:
A buffer loop forming means for forming a buffer loop that is a loop that absorbs a difference in transport speed between two paper transport rollers between the curl correction apparatus and the printing apparatus;
Speed difference recognition means for recognizing a difference between a paper conveyance speed in the curl correction apparatus and a paper conveyance speed in the printing apparatus;
The buffer loop forming means absorbs the speed difference recognized by the speed difference recognizing means, and controls the conveyance speed in the curl correcting device so that the speed difference falls within a certain range. A second control means for controlling the acting force;
A curl straightening device comprising: Claim 5 comprising:
Buffer loop amount increase / decrease detecting means for detecting the buffer loop increase / decrease amount by the buffer loop forming means;
In accordance with the buffer loop increase / decrease amount detected by the buffer loop amount increase / decrease detecting means, the conveyance speed in the curl correction device is controlled so as to keep the buffer loop amount constant, and the curl correction acting force is controlled in parallel. Third control means to do;
A curl straightening device comprising: It is at least 1 of Claim 1 thru | or 6, Comprising:
When the conveyance speed control and the curl correction action force control in the curl correction apparatus are executed in parallel, if the conveyance speed exceeds a certain value, there is provided a fourth control means for controlling the curl correction action force. A curl straightening device characterized by.

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