JP4367303B2 - Image recording device - Google Patents

Description

  The present invention relates to an image recording apparatus.

  In continuous form printers using continuous paper, if paper runs out, paper loss due to JAM, risk of damage to internal equipment, work to remove JAM paper, work required to re-pass continuous paper, etc. A great deal of damage occurs due to loss. For this reason, a safety mechanism has been proposed in which when the paper runs out, it is immediately detected and the entire printer is stopped before damage increases.

  In the past, for example, a roller was installed at the required position and contacted and driven to rotate the paper. When the roller stopped rotating, it was detected as out of paper. Because of the inertia force, the detection of the occurrence of paper out is delayed because it continues to rotate for a while, and only the state of the position where the roller is installed is known.

  Corresponding to this problem, for example, a detecting means connected to the control device is provided, the control device judges the level of the web tension value detected thereby, and the safety device is activated or the operation mode is selected according to the level. The structure of these is proposed (for example, refer patent document 1). However, the above-described method requires a sensor for detecting out of paper, which leads to a complicated structure and an increased number of parts.

In order to solve the above problems, there is a configuration in which it is possible to detect paper out without adding a separate sensor such as a roller sensor or tension sensor at any position downstream of the feed reference roller, which is a reference for the conveyance speed, without adding a sensor such as a roller sensor or a tension sensor. Necessary.
JP 2003-112410 A (FIG. 1, pages 3 to 4)

  In consideration of the above-described facts, an object of the present invention is to provide an image recording apparatus that uses continuous paper and can detect paper out with a simple structure.

The image recording apparatus according to claim 1, wherein the image recording apparatus transfers an image formed on one or a plurality of photosensitive drums arranged in the paper conveyance direction onto a continuous sheet, and is conveyed more than the photosensitive drum. A reference roller that is provided upstream in the direction and serves as a reference for the conveyance speed of the continuous paper, a sub drive roller that is provided downstream of the photosensitive drum in the conveyance direction and pulls the continuous paper, and a photosensitive drum that is downstream in the conveyance direction A tension detecting means provided between the sub drive roller and detecting the tension of the continuous paper, and the tension of the continuous paper is made constant according to the detected tension of the continuous paper detected by the tension detecting means. and control means for controlling the rotational speed of the sub-drive roller, the provided, when the tension of the continuous paper is the reference value, conveying the conveying speed of the sub-drive roller of the reference roller Upon reaching the earlier given speed than degrees it is determined that paper-out, characterized in that it stops the process.

  In the present invention, the rotational speed of the roller means the speed of movement on the outer peripheral surface of the roller.

  In the invention with the above configuration, when the rotation speed of the sub drive roller that pulls the continuous paper reaches a predetermined speed, it is determined that the paper is cut somewhere in the middle of conveyance and the tension applied to the sub drive roller that pulls the continuous paper is reduced. By doing so, it is possible to provide an image recording apparatus that can quickly detect a paper out with a simple structure.

The image recording apparatus according to claim 2 includes a tension control roller that is rotatably supported by an arm and is biased in a direction to apply tension to the continuous paper by a spring, and the tension detection unit is configured to rotate the arm. The tension of the continuous paper is detected by the moving position.

  In the invention with the above configuration, the tension of the continuous paper can be detected without providing a separate tension detecting means by detecting the tension based on the rotational position of the arm that supports the tension control roller.

The image recording apparatus according to claim 3, further comprising a photosensitive drum that rotates at a faster outer peripheral surface speed than the reference roller, wherein the predetermined speed is an outer peripheral surface speed of the photosensitive drum. .

In the invention having the above-described configuration, when the rotation speed of the sub drive roller reaches the conveyance speed of the photosensitive drum rotating at the outer peripheral surface speed higher than that of the reference roller , it is determined that the sheet is out of paper. Can detect a break.

  Since the present invention has the above-described configuration, an image recording apparatus that uses continuous paper and can detect paper out with a simple structure can be obtained.

  1 to 2 show an image recording apparatus according to a first embodiment of the present invention.

  As shown in FIGS. 1 to 2, the color laser printer 10 as an image recording apparatus is configured to print toner images of respective colors of yellow (Y), magenta (M), cyan (C), and black (K) on continuous paper P. The printing units 30Y, 30M, 30C, and 30K that are transferred to and superimposed on each other are sequentially arranged from the upstream side in the transport direction. In this embodiment, the description will be made using the continuous paper P having no feed hole. However, the continuous paper P having the feed hole may be used.

  On the upstream side in the transport direction of the print units 30Y to 30K, a paper transport unit 20 that transports the wound continuous paper P to the print units 30Y to 30K is provided. A fixing unit 40 that fixes the unfixed toner image transferred by the printing units 30Y to 30K to the continuous paper P is provided on the downstream side in the transport direction of the printing units 30Y to 30K.

  The paper transport unit 20 includes a main drive roller 102 around which the continuous paper P is wound. An idle roller 104 is in contact with the main drive roller 102, and the continuous paper P is conveyed with the continuous paper P sandwiched between the nip portions of the main drive roller 102 and the idle roller 104. The main drive roller 102 is always driven at a constant speed by a motor 106, and this speed becomes a reference for the transport speed of the continuous paper P transported in the apparatus.

  Each of the printing units 30Y to 30K includes a photosensitive drum 12, and around the photosensitive drum 12, a transfer roller 18, a neutralizing charger, and a cleaning are sequentially arranged in the rotation direction of the photosensitive drum 12 (counterclockwise in the drawing). An apparatus, a charging charger, an LED head 14 and a developing device 16 are provided.

  The transfer roller 18 includes guide rollers 22 before and after the conveying direction to form a transfer portion 31. The transfer roller 18 serving as a transfer unit is in contact with the upper surface of the photoconductive drum 12 and sandwiches and conveys the continuous paper P supported by the guide roller 22 together with the photoconductive drum 12. The toner image formed above is transferred onto the continuous paper P. The continuous paper P to which the toner image has been transferred is conveyed to the fixing unit 40, where the toner image on the surface is fixed by heat and output as a printout image.

  The paper transport unit 20 transports the continuous paper P at a constant speed by the main drive roller 102 as described above. The main drive roller 102 is driven by a motor 106 and rotates at a constant speed, and serves as a reference for the transport speed of the continuous paper P in the printing unit 30 and the fixing unit 40 on the downstream side in the transport direction.

  On the other hand, the photosensitive drum 12 downstream in the transport direction is driven by a motor (not shown) so that the surface (outer peripheral surface) speed rotates at a speed faster than the reference speed. As a result, the continuous paper P is always pulled from the downstream side in the transport direction, so that the continuous paper P is loosened, wrinkled, etc. until it passes from the main drive roller 102 through the photosensitive drums 12 (four in the figure) connected in the transport direction. It is possible to transport while always maintaining the reference speed in a situation where it is difficult to generate.

  The toner image on the surface of the continuous paper P is fixed on the surface of the continuous paper P by the flash lamp 108 at the fixing unit 40 at the downstream side of the transport direction by heating and melting. The continuous paper P that has been fixed is further conveyed out of the apparatus.

  At this time, the sub drive roller 110 transports the continuous paper P downstream of the flash lamp 108 in the transport direction. That is, the continuous paper P conveyed while sliding on the surface of the photosensitive drum 12 rotating faster than the reference speed is pulled downstream, and is conveyed at the reference speed while applying a constant tension.

  That is, as shown in FIG. 2, in order to give the continuous paper P a constant tension, the tension control roller 112 urged by the tension applying spring 120 in the direction perpendicular to the conveyance surface of the continuous paper P is tensioned on the continuous paper P. And the amount of looseness of the continuous paper P at that time is detected by the position of the tension control roller 112.

  That is, the rotation angle of the arm 114 that supports both ends of the tension control roller in the axial direction is detected by the encoder 118, and the rotation speed of the sub drive roller 110 that holds and conveys the continuous paper P on the downstream side so that this value is constant. Is controlled by controlling the rotational speed of the sub drive roller drive motor 122.

  At this time, the speed of the sub drive roller drive motor 122 is determined according to the tension of the continuous paper P detected by the position of the tension control roller 112. That is, if the tension of the continuous paper P is increased, the amount of looseness of the continuous paper P is reduced, so that the tension control roller 112 is pushed in the direction in which the continuous paper P does not slack (right in the figure). For this reason, the arm 114 also rotates rightward in the figure, and a signal in the + direction (high tension) is detected at the encoder 118 connected to the arm 114 by the shaft 116.

  In response to this signal, the sub-drive roller drive motor 122 is fed back, and if the rotation speed of the sub-drive roller 110 is decreased, the conveyance speed is decreased, so that the amount of looseness of the continuous paper P increases. It rotates in the direction to push in (left in the figure). As a result, the arm 114 also rotates leftward in the figure, and a signal in the negative direction (low tension) is detected at the encoder 118 connected to the arm 114 by the shaft 116.

  On the other hand, if the tension of the continuous paper P is weakened, the amount of looseness of the continuous paper P increases, so that the tension control roller 112 is pulled in the direction in which the continuous paper P is loosened (left in the figure). For this reason, the arm 114 also rotates leftward in the figure, and a signal in the negative direction (low tension) is detected by the encoder 118 connected to the arm 114 by the shaft 116.

  In response to this signal, the sub drive roller drive motor 122 is fed back, and if the rotation speed of the sub drive roller 110 is increased, the conveying speed is increased, so that the amount of looseness of the continuous paper P is reduced, and the tension control roller 112 is supplied to the continuous paper P. It rotates in the direction (right in the figure) to be pushed. As a result, the arm 114 also rotates to the right in the figure, and a signal in the + direction (high tension) is detected at the encoder 118 connected to the arm 114 by the shaft 116.

  By repeating the above processing, the sub drive roller 110 changes its rotational speed slightly with respect to the main drive roller 102 so that the tension control roller 112 is at a constant position, that is, the tension of the continuous paper P is constant. Thus, the continuous paper P is conveyed.

  At this time, when the continuous paper P conveyed from the main drive roller 102 is cut upstream of the sub drive roller 110, the photosensitive drum 12 rotates at a faster speed than the main drive roller 102. If the roller 110 does not wind the continuous paper P at a speed higher than the reference speed, the tension control roller 112 detects a decrease in tension.

  In other words, after the sheet has run out, the tension of the continuous paper P detected by the tension control roller 112 is maintained at the reference value, so that the sub drive roller 110 is rotationally controlled at a speed faster than the reference speed. In such a situation, that is, when the rotation speed of the sub drive roller reaches a predetermined transfer rate that is faster than the reference while the tension is the reference value, in the present invention, the position between the main drive roller 102 and the sub drive roller 110 is It is determined that the paper has run out.

  A specific control method is shown below.

  FIG. 4 shows a control device 300 that controls the operation of the image recording apparatus according to the first embodiment of the present invention, and FIG. 3 shows a paper out determination routine that the control device 300 performs.

    FIG. 4 shows a block diagram of the control device 300. CPU 301 for executing the program, ROM 302 for storing the program, RAM 303 used as a work area at the time of executing the program, input interface for inputting control information from the upper controller, input information from the operation panel, and information from the encoder 118 (I / F), the motor 106 that drives the main sub drive roller, the driver device 320 that drives the sub drive roller drive motor 122, and the like.

  As shown in FIG. 3, the sub drive roller is obtained based on the result obtained by comparing the output value of the encoder 118 provided on the shaft 116 that is the rotation center of the arm 114 that supports the tension control roller 112 with a reference value. By controlling the rotational speed of the drive motor 122, it is possible to maintain an appropriate tension from the amount of looseness caused by the fluctuation of the tension of the continuous paper P. At this time, if the transport speed of the sub drive roller 110 by the sub drive roller drive motor 122 is faster than the transport speed of the main drive roller 102, it is determined that the paper is out, and the image recording apparatus 10 is stopped.

  First, in step 200 of FIG. 3, the output of the encoder 118 is compared with a reference value. If they are equal, the tension of the continuous paper P is appropriate and the process proceeds to step 206 without changing the transport speed of the sub drive roller drive motor 122.

  In step 206, the conveyance speeds of the sub drive roller 110 and the main drive roller 102 are compared. If the conveyance speeds of the sub drive roller 110 and the main drive roller 102 are equal or the main drive roller 102 is fast, it is determined that there is no abnormality, and the process returns to step 200.

  However, if the conveyance speed of the sub drive roller 110 is higher than that of the main drive roller 102, it is determined that the paper has run out between the main drive roller 102 and the sub drive roller 110 as described above, and the process proceeds to step 208 to record an image. The apparatus 10 is stopped.

  If the output of the encoder 118 is larger than the reference value in step 200, the shaft 116, which is the rotation center of the arm 114 that supports the tension control roller 112, is rotating in the + direction (strong tension). In order to reduce the tension, the speed of the sub drive roller drive motor 122 that drives the sub drive roller 110 is reduced by one step. As a result, the conveyance speed of the sub drive roller 110 decreases, so that the amount of looseness of the continuous paper P increases, and the tension control roller 112 rotates in the negative direction (weak tension).

  Here, the process proceeds to step 206 where the conveyance speeds of the sub drive roller 110 and the main drive roller 102 are compared. If the conveyance speeds of the sub drive roller 110 and the main drive roller 102 are equal or the main drive roller 102 is fast, it is determined that there is no abnormality, and the process returns to step 200. If the conveyance speed of the sub drive roller 110 is higher than that of the main drive roller 102, it is determined that the paper has run out between the main drive roller 102 and the sub drive roller 110, and the process proceeds to step 208 to stop the image recording apparatus 10. .

  If the output of the encoder 118 is smaller than the reference value in step 200, the shaft 116, which is the rotation center of the arm 114 supporting the tension control roller 112, is rotating in the negative direction (weak tension), and the continuous paper P In order to increase the tension, the speed of the sub drive roller drive motor 122 that drives the sub drive roller 110 is increased by one step. As a result, the conveyance speed of the sub drive roller 110 increases, so that the amount of looseness of the continuous paper P decreases, and the tension control roller 112 rotates in the + direction (high tension).

  Here, the process proceeds to step 206 where the conveyance speeds of the sub drive roller 110 and the main drive roller 102 are compared. If the conveyance speeds of the sub drive roller 110 and the main drive roller 102 are equal or the main drive roller 102 is fast, it is determined that there is no abnormality, and the process returns to step 200. If the conveyance speed of the sub drive roller 110 is higher than that of the main drive roller 102, it is determined that the paper has run out between the main drive roller 102 and the sub drive roller 110, and the process proceeds to step 208 to stop the image recording apparatus 10. .

  As described above, in the present invention, a paper out determination routine for comparing the conveyance speeds of the sub drive roller 110 and the main drive roller 102 is added in the middle of the control flow of the sub drive roller drive motor 122, and the sheet is determined from the conveyance speed of both rollers. By adopting a configuration for detecting the out of paper, it is possible to instantaneously detect the out of paper in the apparatus without providing a dedicated sensor or the like, and it is possible to simultaneously improve performance and reduce the cost of the apparatus.

1 is a side view showing an image recording apparatus according to a first embodiment of the present invention. 1 is a perspective view showing an image recording apparatus according to a first embodiment of the present invention. It is a flowchart which shows operation | movement of the image recording apparatus which concerns on the 1st form of this invention. It is a block diagram which shows the control apparatus of the image recording apparatus which concerns on the 1st form of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image recording device 12 Photosensitive drum 14 Head 16 Developing device 20 Paper conveyance part 30 Printing part 40 Fixing part 102 Main drive roller 110 Sub drive roller 112 Tension control roller 118 Encoder

Claims (3)

An image recording apparatus for transferring an image formed on one or a plurality of photosensitive drums arranged in a paper conveyance direction onto continuous paper,
A reference roller provided upstream of the photosensitive drum in the transport direction and serving as a reference for the transport speed of the continuous paper;
A sub-drive roller provided downstream of the photosensitive drum in the transport direction and pulling the continuous paper;
A tension detecting means provided between the photosensitive drum on the most downstream side in the conveying direction and the sub drive roller, and detects the tension of the continuous paper;
Control means for controlling the rotation speed of the sub drive roller so that the tension of the continuous paper is constant according to the detected tension of the continuous paper detected by the tension detection means;
When the tension of the continuous paper is a reference value, if the transport speed of the sub drive roller reaches a predetermined speed that is faster than the transport speed of the reference roller , it is determined that the paper is out, and the process is stopped. Image recording device.
A tension control roller supported rotatably by an arm and biased in a direction to give tension to the continuous paper by a spring;
The image recording apparatus according to claim 1, wherein the tension detecting unit detects a tension of the continuous paper based on a rotational position of the arm.
Has a photoreceptor drum rotating at a faster peripheral surface speed than the reference roller, said predetermined speed, according to claim 1 or claim 2, characterized in that the outer peripheral surface speed of the photosensitive drum Image recording device.

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