JP2021066573A - Sheet supply device and print device - Google Patents

Abstract

To automatically feed sheets by accurately detecting sheet peeling from a roll even when deviation and collapse exist in the roll itself.SOLUTION: In automatic sheet feeding of a roll, by using feedback from a sensor, which is provided to a position to which a sheet outer surface of a sheet peeled from an outer periphery of the roll approaches and varies sensor output according to a distance to the sheet outer surface, and from driving means which rotates the roll, a peeling position of the sheet is specified by using sensor data acquired while rotating the roll in a second direction and feedback data, and, on the basis of the position, a rotation direction of the roll is changed into a first direction opposite to the second direction to feed the sheet.SELECTED DRAWING: Figure 11

Description

The present invention relates to a sheet feeding device and a printing device for pulling out and supplying a sheet from a roll on which a continuous sheet is wound.

Patent Document 1 discloses a printing device capable of detecting the tip of a sheet of a mounted roll and automatically feeding the sheet. In this device, the roll is rotated in the winding direction opposite to the supply direction, and the fact that the sheet tip is separated from the roll by its own weight is detected by an optical sensor arranged near the roll.

Japanese Unexamined Patent Publication No. 2011-37557

The above-mentioned optical sensor of Patent Document 1 detects the peeling of the sheet when the tip of the sheet peeled from the roll is turned on by the reflected light at the moment when it passes through the sensor optical axis parallel to the tangent of the roll. ..

However, in an actual device, the roll itself may be biased or crushed, and the distance between the roll surface and the sensor may fluctuate depending on the shape of the roll. Therefore, in the configuration in which the on-output is obtained by the reflected light at the moment of passing through the sensor optical axis parallel to the tangent line of the roll as in Patent Document 1, if the roll itself is biased, a signal pulse is generated at a place other than the sheet tip. There is a problem that it is difficult to detect the sheet peeling with high accuracy because it is erroneously detected as the tip of the sheet. Patent Document 1 does not disclose any solution to such a problem.

An object of the present invention is to provide a sheet feeding device and a printing device capable of accurately detecting sheet peeling from a roll and performing automatic feeding even when the roll itself is biased.

In order to achieve the above object, the sheet supply device according to the present invention is
A driving means for rotating a roll on which a continuous sheet is wound in a first direction and a second direction opposite to the first direction, a rotation phase control means capable of grasping the rotation phase of the roll, and a sheet from the roll. A sheet supply device having a sensor for detecting peeling and a specific means for specifying a sheet peeling position, and feeding the sheet while rotating the roll in the first direction. The sensor is a sheet supply device. The sheet is provided at a position where the outer surface of the sheet peeled off from the outer periphery of the roll approaches, and the sensor output changes according to the distance to the outer surface of the sheet, and the driving means outputs feedback according to the drive control. The sensor output and the feedback output are acquired while the roll is rotated in the second direction by the driving means, and the sheet peeling position from the roll is specified by the specific means using the acquired outputs. The driving means is characterized in that after rotating to the peeling position, the rotation direction of the roll is changed from the second direction to the first direction.

According to the sheet feeding device according to the present invention, even if the roll itself is biased, the sheet peeling from the roll can be accurately detected and automatic feeding can be performed.

It is a perspective view of the printing apparatus in embodiment of this invention. It is explanatory drawing of the transfer path of a sheet in a printing apparatus. It is explanatory drawing of the sheet feeding device. It is explanatory drawing of the sheet feeding apparatus when a roll outer diameter is small. It is a block diagram for demonstrating the control system of a printing apparatus. It is a flowchart of the supply preparation process of a sheet. It is explanatory drawing of the sensor unit in embodiment of this invention. It is explanatory drawing of the sheet supply apparatus in embodiment of this invention. It is explanatory drawing of the sheet supply apparatus in embodiment of this invention. It is explanatory drawing of the sheet supply apparatus in embodiment of this invention. It is explanatory drawing of the sensor output from the sensor unit in embodiment of this invention. It is explanatory drawing of the feedback output from the roll drive motor in embodiment of this invention. It is a flowchart for demonstrating the sheet tip setting process in 1st Embodiment of this invention. It is a flowchart for demonstrating the sheet tip setting process. It is a flowchart for demonstrating the sheet tip setting process. It is a flowchart for demonstrating the sheet tip setting process. It is a flowchart for demonstrating the sheet tip setting process. It is a flowchart for demonstrating the Sesheet tip setting process in 2nd Embodiment of this invention. It is explanatory drawing when the correction of the sensor output of the 2nd Embodiment of this invention is not carried out. It is explanatory drawing when the correction of the sensor output of the 2nd Embodiment of this invention is not carried out. It is explanatory drawing when the correction of the sensor output of the 2nd Embodiment of this invention is not carried out. It is explanatory drawing at the time of carrying out the correction of the sensor output of the 2nd Embodiment of this invention. It is explanatory drawing at the time of carrying out the correction of the sensor output of the 2nd Embodiment of this invention.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

First, the basic configuration of the present invention will be described.

<Basic configuration>
1 to 5 are explanatory views of a basic configuration of a printing apparatus as an embodiment of the present invention.

The printing device of this example is an inkjet printing device including a sheet feeding device for supplying a sheet as a printing medium and a printing unit for printing an image on the sheet. For the sake of explanation, the coordinate axes are set as shown in the figure. That is, the sheet width direction of the roll R is the X-axis direction, the direction in which the sheet is conveyed in the printed portion 400 described later is the Y-axis direction, and the gravity direction is the Z-axis direction.

As shown in FIG. 1, in the printing apparatus 100 of this example, rolls R (roll sheets) obtained by winding sheet 1 which is a long continuous sheet (sometimes called a web) into a roll shape are placed in upper and lower stages. It is possible to set each of the two roll holding portions. An image is printed on the sheet 1 selectively drawn from those rolls R. The user can input various commands to the printing device 100, such as specifying the size of the sheet 1 and switching between online / offline, using various switches provided on the operation panel 28.

FIG. 2 is a schematic cross-sectional view of a main part of the printing apparatus 100.

Two supply devices 200 corresponding to the two rolls R are arranged one above the other. The sheet 1 pulled out from the roll R by the supply device 200 is conveyed by the sheet conveying unit (conveying mechanism) 300 to the printing unit 400 on which an image can be printed along the sheet conveying path. The print unit 400 prints an image on the sheet 1 by ejecting ink from the inkjet print head 18. The print head 18 discharges ink from a discharge port by using a discharge energy generating element such as an electric heat conversion element (heater) or a piezo element. The print head 18 is not limited to the inkjet method, and the print method of the print unit 400 is also not limited. For example, a serial scan method or a full line method may be used. In the case of the serial scan method, the image is printed with the conveying operation of the sheet 1 and the scanning of the print head 18 in the direction intersecting the conveying direction of the sheet 1. In the case of the full-line method, an image is printed while the sheet 1 is continuously conveyed by using a long print head 18 extending in a direction intersecting the conveying direction of the sheet 1.

The roll R is set in the roll holding portion of the supply device 200 with the spool member 2 inserted in the hollow hole portion, and the spool member 2 is rotated forward and reverse by the motor 33 for driving the roll (see FIG. 5). Driven. As will be described later, the supply device 200 includes a drive unit 3, an arm member (moving body) 4, an arm rotating shaft 5, a sensor unit 6, a swinging member 7, a driven rotating body (contact body) 8, 9, and a separation flapper. (Upper guide body) 10 and a flapper rotation shaft 11 are provided.

The transport guide 12 guides the front and back surfaces of the sheet 1 pulled out from the supply device 200, and guides the sheet 1 to the printing unit 400. The transfer roller 14 is rotated forward and reverse in the directions of arrows D1 and D2 by a motor 35 for driving the transfer roller (see FIG. 5), which will be described later. The nip roller 15 can be driven and rotated according to the rotation of the transfer roller 14, and can be brought in and out of the transfer roller 14 and the nip force can be adjusted by the motor 37 for adjusting the nip force (see FIG. 5). is there. The transfer speed of the sheet 1 by the transfer roller 14 is set higher than the pull-out speed of the sheet 1 due to the rotation of the roll R, whereby back tension is applied to the sheet 1 and the sheet 1 is conveyed in a stretched state. Can be done.

The platen 17 of the printing unit 400 regulates the position of the sheet 1, and the cutter 20 cuts the sheet 1 on which the image is printed. The cover 42 of the roll R prevents the sheet 1 on which the image is printed from returning to the supply device 200. The operation of the printing device 100 is controlled by the CPU 201 (see FIG. 5) described later. The platen 17 is provided with means for adsorbing negative pressure or electrostatic force, and can adsorb a sheet on the platen to provide stable support.

FIG. 3 is an explanatory view of the supply device 200, and the roll R in FIG. 3A has a relatively large outer diameter.

An arm member (moving body) 4 is rotatably attached to the transport guide 12 by an arm rotation shaft 5 in the directions of arrows A1 and A2. A guide portion 4b (lower guide body) for guiding the lower surface of the seat 1 pulled out from the roll R is formed on the upper portion of the arm member 4. A torsion coil spring 3c that presses the arm member 4 in the direction of arrow A1 is interposed between the arm member 4 and the rotary cam 3a of the drive unit 3. The rotary cam 3a is rotated by a motor 34 (see FIG. 5) for adjusting the pressing force, which will be described later, and the force with which the torsion coil spring 3c presses the arm member 4 in the direction of arrow A1 changes according to the rotation position. When the tip of the seat 1 (a part of the seat 1 including the tip) is set in the seat supply path through between the arm member 4 and the separation flapper 10, the torsion coil spring is set according to the rotation position of the rotary cam 3a. The pressing force of the arm member 4 by 3c is switched in three stages. That is, it is switched between a pressing state by a relatively small force (pressing pressure of a weak nip), a pressing state by a relatively large force (pressing pressure of a strong nip), and a pressing state by releasing the pressing force.

A swinging member 7 is swingably attached to the arm member 4, and the first and second driven rotating bodies (rotating bodies) 8, which are located on the swinging member 7 so as to be displaced in the circumferential direction of the roll R, 9 is rotatably attached. These driven rotating bodies 8 and 9 move according to the outer shape of the roll R, and the outer peripheral portion of the roll R is pressed against the arm member 4 from below in the direction of gravity by the pressing force in the direction of the arrow A1. That is, the driven rotating bodies 8 and 9 are pressed against the outer peripheral portion of the roll R from below the central axis in the horizontal direction of the roll R in the gravitational direction. The pressure contact force is changed according to the pressing force that presses the arm member 4 in the direction of arrow A1.

A plurality of arm members 4 each having a swing member 7 are provided so as to have different positions in the X-axis direction. As shown in FIG. 3B, the swing member 7 is provided with a bearing portion 7a and a shaft fastening portion 7b, whereby the rotating shaft 4a of the arm member 4 is received with a predetermined backlash.

The bearing portion 7a is provided at the position of the center of gravity of the rocking member 7, and is supported on the rotating shaft 4a so that the rocking member 7 has a stable posture in each of the X-axis direction, the Y-axis direction, and the Z-axis direction. Will be done. Further, since the rotating shaft 4a is accepted with play, the swinging member 7 at any position in the X-axis direction is displaced along the outer peripheral portion of the roll R by the pressing force in the arrow A1 direction with respect to the arm member 4. To do. With such a configuration (equalization mechanism), changes in the pressure contact postures of the first and second driven rotating bodies 8 and 9 with respect to the outer peripheral portion of the roll R are allowed. As a result, the contact area between the sheet 1 and the first and second driven rotating bodies 8 and 9 is always kept at the maximum, and the pressing force on the sheet 1 is equalized, so that the conveying force of the sheet 1 is increased. Variation can be suppressed. When the driven rotating bodies 8 and 9 are in pressure contact with the outer peripheral portion of the roll R, the occurrence of slack in the sheet 1 is suppressed and the carrying force thereof is enhanced.

A separation flapper 10 located above the arm member 4 is rotatably attached to the main body (printer main body) of the printing device 100 in the directions of arrows B1 and B2 about the flapper rotation shaft 11. The separation flapper 10 is configured to come into contact with the outer peripheral surface of the roll R by its own weight and lightly press it. When it is necessary to press the roll R more strongly, an urging force by an urging member such as a spring may be used. A driven roller 10a is rotatably provided at a portion of the separation flapper 10 in contact with the roll R in order to suppress the influence of the pressing force on the sheet 1. Further, the separation portion 10b at the tip of the separation flapper 10 is formed so as to extend to a position as close as possible to the surface of the roll R in order to facilitate separation of the tip portion of the sheet from the roll R.

The seat 1 is pulled out from the roll R by passing over the driven rotating bodies 8 and 9, and the lower surface thereof is guided by the guide portion 4b at the upper part of the arm member 4, and then between the separation flapper 10 and the arm member 4. It is supplied through the supply path formed. In this way, the driven rotating bodies 8 and 9 are pressed against the outer peripheral portion of the roll R from below, and the lower surface of the sheet 1 pulled out over the driven rotating bodies 8 and 9 is guided by the guide portion 4b. .. As a result, the seat 1 can be smoothly supplied by utilizing the weight of the seat 1. Further, by moving the driven rotating bodies 8 and 9 and the guide portion 4b according to the outer diameter of the roll R, the sheet 1 can be reliably pulled out from the roll R and conveyed regardless of the outer diameter of the roll R. it can.

One of the features of the apparatus in this embodiment is an automatic sheet loading function (automatic paper feeding function). In automatic loading, when the user sets an unused roll R in the apparatus, the apparatus sets the roll R in the direction opposite to that when the sheet is supplied (when feeding paper) (referred to as the reverse direction or the second direction), FIG. 3 (a). ), The tip of the sheet is detected while rotating in the direction of arrow C2). Next, the apparatus rotates the roll R in the rotation direction (referred to as the forward direction or the first direction, the direction of the arrow C1 in FIG. 3A) when the sheet is supplied, and automatically rotates the tip portion of the sheet separated from the roll R. Send out. The sensor unit 6 is a unit including a tip detection sensor that detects that the tip portion of the sheet 1 is peeled off from the outer peripheral surface of the roll R and the sheet is peeled off (sheet separation). The tip portion of the sheet 1 detected by the sensor unit 6 is automatically inserted into the sheet supply path between the arm member 4 and the separation flapper 10 and sent out. A more detailed procedure for this automatic loading function will be described later.

Further, the printing device 100 of this example includes two upper and lower supply devices 200, from a state in which the sheet 1 is supplied from one supply device 200 to a state in which the sheet 1 is supplied from the other supply device 200. Can be switched. In such a case, one of the supply devices 200 rewinds the sheet 1 previously supplied to the roll R. The tip of the sheet 1 is retracted to a position where it is detected by the sensor unit 6 or another sheet end sensor provided in the vicinity of the sensor unit 6.

FIG. 4 is an explanatory diagram of the supply device 200 when the outer diameter of the roll R is relatively small.

Since the arm member 4 is always pressed in the direction of arrow A1 by the torsion coil spring 3c, the arm member 4 rotates in the direction of arrow A1 as the outer diameter of the roll R decreases. Further, by rotating the rotary cam 3a according to the change in the outer diameter of the roll R, the pressing force of the arm member 4 by the torsion coil spring 3c is maintained within a predetermined range regardless of the change in the outer diameter of the roll R. be able to. Further, since the separation flapper 10 is also constantly pressed in the direction of arrow B1, it rotates in the direction of arrow B1 as the outer diameter of the roll R decreases. As a result, the separation flapper 10 forms a supply path with the transport guide 12 even when the outer diameter of the roll R becomes small, and guides the upper surface of the sheet 1 with the lower surface 10c. In this way, the arm member 4 and the separation flapper 10 rotate according to the change in the outer diameter of the roll R, so that a substantially constant size is supplied between them regardless of the outer diameter of the roll R. A path is formed.

FIG. 5 is a block diagram for explaining a configuration example of the control system in the printing apparatus 100.

The CPU 201 of the printing apparatus 100 controls each unit of the printing apparatus 100 including the supply apparatus 200, the sheet conveying unit 300, and the printing unit 400 according to the control program stored in the ROM 204. The type, width, various setting information, and the like of the sheet 1 are input to the CPU 201 from the operation panel 28 via the input / output interface 202. Further, the CPU 201 is connected to various external devices 29 including a host device such as a personal computer via the external interface 205, and exchanges various information such as print data with and from the external device 29. Further, the CPU 201 writes and reads information about the sheet 1 and the like to the RAM 203. Further, the CPU 201 identifies the tip of the roll by using the values output from the roll drive motor 33 and the sensor unit 6. The roll drive motor 33 is a roll drive motor for rotating the roll R in the forward and reverse directions via the spool member 2, and constitutes a drive mechanism (rotation mechanism) capable of rotationally driving the roll R. In addition, feedback data is output to the CPU 201. The CPU 201 controls the roll drive motor based on the feedback data.

The output of the sensor unit 6 changes according to the distance facing the surface (outer surface) of the sheet 1, and the output is sent to the CPU 201. The push pressure adjusting motor 34 is a motor that rotates the rotary cam 3a to adjust the push pressure on the arm member 4, and the transfer roller drive motor 35 is for rotating the transfer roller 14 in the forward direction and in the reverse direction. It is a motor. The roll sensor 32 is a sensor for detecting the spool member 2 of the roll R when the roll R is set in the supply device 200. The roll rotation amount sensor 36 is a sensor (rotation angle detection sensor) for detecting the rotation amount of the spool member 2, that is, the roll R. For example, a rotary encoder that outputs a number of pulses corresponding to the rotation amount of the roll R. Is.

<Sheet supply preparation process>
FIG. 6 is a flowchart for explaining the supply preparation process of the sheet 1 starting from the set of the roll R.

The CPU 201 of the printing device 100 stands by in a state of pressing the arm member 4 in the direction of arrow A1 by the "pressing pressure of the weak nip" (weak nip state), and first determines whether or not the roll R is set. (Step S1). In this example, when the roll sensor 32 detects the spool member 2 of the roll R, it is determined that the roll R is set. After the roll R is set, the CPU 201 switches to a state in which the arm member 4 is pressed in the direction of the arrow A1 by the “strong nip pressing force” (strong nip state) (step S2). Next, the CPU 201 executes a sheet tip setting process of setting the tip of the sheet 1 in the seat supply path through between the arm member 4 and the separation flapper 10 (step S3). By this sheet tip setting process (automatic loading), the tip of the sheet 1 is set (inserted) in the sheet supply path. The details of the sheet tip setting process will be described later.

After that, the CPU 201 rotates the roll R in the direction of the arrow C1 by the roll driving motor 33, and starts supplying the sheet 1 (step S4). When the tip of the sheet 1 is detected by the seat sensor 16 (step S5), the CPU 201 rotates the transport roller 14 in the forward direction in the direction of arrow D1 to pick up the tip of the sheet 1, and then moves the motor 33 and the motor 35. Stop (step S6). After that, the CPU 201 releases the pressing force that presses the arm member 4 in the direction of the arrow A1 to separate the first and second driven rotating bodies 8 and 9 from the roll R (nip release state) (step S7).

After that, the CPU 201 determines whether or not the sheet is conveyed (obliquely skewed) in the sheet conveying unit 300 while being inclined at an angle. Specifically, a predetermined amount of the sheet 1 is transported in the sheet transport unit 300, and the skew amount generated at that time is detected by a carriage on which the print head 18 is mounted or a sensor provided in the sheet transport unit 300. When the amount of skewing is larger than a predetermined allowable amount, the feed and back feed of the sheet 1 are repeated with the transfer roller 14 and the roll R rotating forward and reverse while applying back tension to the sheet 1. By such an operation, the skew of the sheet 1 is corrected (step S8). In this way, when the skew of the sheet 1 is corrected and the image is printed on the sheet 1, the driven rotating bodies 8 and 9 correct the skew of the sheet 1 by setting the supply device 200 to the nip release state. It is possible to avoid the influence on the accuracy and the print accuracy of the image. After that, the CPU 201 moves the tip of the sheet 1 to the standby position (fixed position) before the start of printing in the printing unit 400 by the sheet conveying unit 300 (step S9). As a result, the preparation for supplying the sheet 1 is completed. After that, the sheet 1 is pulled out from the roll R with the rotation of the roll R, and is conveyed to the printing unit 400 by the sheet conveying unit 300.

(First Embodiment)
Hereinafter, as an embodiment of the present invention, the sheet tip setting process (step S3) of FIG. 6 in such a basic configuration of the printing apparatus 100 will be described.

An example of the sensor unit 6 in this embodiment will be described with reference to FIG. 7.

As shown in FIG. 7, the sensor unit 6 is an optical sensor unit including a light emitting unit 6c such as an LED and a light receiving unit 6d such as a photodiode. The light emitted from the light emitting unit 6c toward the roll R is reflected by the surface of the sheet 1 on the roll R and then detected by the light receiving unit 6d. The light emitted from the light emitting unit 6c and detected by the light receiving unit 6d includes specularly reflected light reflected from the surface of the sheet 1 on the roll R. The output value of the light receiving unit 6b changes according to the facing distance between the sensor unit 6 and the downward surface of the sheet 1 (the outer surface of the sheet which was the outer peripheral surface of the roll and the surface printed by the printing unit). That is, the output value of the light receiving unit 6b increases as the distance (distance) between the sensor unit 6 and the surface of the sheet 1 decreases, and the distance (interval) increases and becomes substantially smaller.

The sensor unit 6 may have a configuration in which the output value of the detection signal changes according to the distance between the sensor unit 6 and the surface of the sheet 1, and the light emitting unit 6c and the light receiving unit 6d are limited to LEDs and photodiodes only. Not limited. Further, the light detected by the light receiving unit 6d is not limited to the specularly reflected light. The sensor unit 6 is connected to the CPU 201 (see FIG. 5), and the CPU 201 acquires the detection result of the sensor unit 6 at an arbitrary timing.

An example of the roll drive motor 33 in this embodiment will be described. The roll drive motor is composed of a DC motor and a PWM signal generation circuit, and drives and controls the DC motor with a PWM control signal generated by the PWM generation circuit. Since the DC motor has a proportional relationship between torque and current, it detects the current and outputs it to the CPU 201 as feedback data. The CPU 201 controls the PWM signal generation circuit based on the feedback output according to the state of the printing device 100.

Next, using FIGS. 8, 9 and 10, the influence on the fluctuation of the feedback output (load current of the motor) of the roll drive motor 33 and the fluctuation of the output signal of the sensor unit 6 due to the bias toward the roll R will be shown. In order to make it easy to understand the influence of the bias, the sheet tip 1 of the roll R is not peeled off and is in a state of being on the surface of the roll R.

FIG. 8A shows a sheet supply device with a biased roll R attached, and FIGS. 8B and 8C show a sheet supply device with a biased roll R attached. In FIG. 8B, FIG. 8C is a state in which the roll R is rotated by 90 degrees. FIG. 9 is a diagram showing the rotation angle and the output fluctuation of the sensor unit when the roll R is rotated at a constant speed depending on whether the roll R is biased or not. The solid line is the output of the sensor unit on a roll with a bias, and the dotted line is the output of the sensor unit on a roll with no bias. FIG. 10 is a diagram showing output fluctuations of the rotation angle when the roll is rotated and the feedback output (motor load current) of the roll drive motor 33 when the roll R is biased and when the roll R is not biased. The solid line is the output of the sensor unit on a roll with a bias, and the dotted line is the output of the sensor unit on a roll with no bias.

When the roll R is rotated in the second direction at a constant speed without bias as shown in FIG. 8A, the sensor output and the feedback output basically fluctuate as shown by the dotted lines in FIGS. 9 and 10. Is a constant value. Since the distance between the roll surface and the sensor unit does not change even if the roll R rotates, the sensor output value becomes constant. Moreover, since the drive load does not change, the load current (feedback output) is constant because the motor is operated with the same torque.

When the roll R is rotated in the second direction at a constant speed in a biased state as shown in FIGS. 8 (b) and 8 (c), the sensor output and the feedback output are as shown by the solid lines in FIGS. 9 and 10. Fluctuates to. FIG. 9 shows the fluctuation of the sensor output. Due to the bias of the roll R, the distance between the outermost surface of the roll and the sensor unit changes depending on the rotation position of the roll, and the sensor output also changes accordingly. Further, FIG. 10 shows the fluctuation of the feedback output. The feedback (load current) of the roll drive motor 33 also fluctuates because the load changes due to the influence of the bias. In the state shown in FIGS. 8 (b) and 8 (c), when the distance between the biased roll surface and the sensor is short, the heavy (biased) part of the paper goes in the lowering direction and the light part is raised, so the motor On the contrary, when the distance between the roll surface and the sensor is long, the load on the drive unit becomes heavier because the lighter part of the paper goes up and the heavier part goes up. The amount of current goes up. That is, the feedback output also fluctuates according to the roll bias.

From the relationship of output fluctuations shown in FIGS. 9 and 10, it can be seen that there is a correlation between the sensor output and the feedback output due to the roll bias. Therefore, the influence of bias can be reduced by correcting the sensor output according to the amplitude of the feedback output. Further, since the feedback output is originally used for the CPU 201 to control the roll drive motor 33, it can be handled without adding a new signal line for correcting the sensor output. ..

In this embodiment, the current consumption of the motor is used as the feedback output with respect to the sensor output, and the correction is performed using the correlation. However, the influence of the roll bias on the sensor output can be reduced. Any feedback output may be used as long as it is to be used.

The sheet tip setting process (step S3 in FIG. 6) using the sensor unit 6 will be described with reference to FIGS. 11 and 12.

FIG. 11 is a flowchart of the sheet tip setting process (step S3 in FIG. 6) using the sensor unit 6.

As described above, in the sheet tip setting process (automatic loading), after the roll R is set, the tip of the sheet 1 of the roll R is automatically inserted into the sheet supply path between the arm member 4 and the separation flapper 10. It is a process of inserting and sending out. The arm member 4 faces the front surface of the seat 1 (outer surface of the seat), and the separation flapper 10 faces the back surface of the seat 1 (inner surface of the seat).

Prior to starting the sheet tip setting process, the CPU 201 first determines whether or not the roll R has been set (step S1 in FIG. 6). In this example, when the roll sensor 32 detects the spool member 2 of the roll R, it is determined that the roll R is set. After the roll R is set, the CPU 201 switches to a state in which the arm member 4 is pressed in the direction of the arrow A1 by the “strong nip pressing force” (strong nip state) (step S2 in FIG. 6).

In the subsequent sheet tip setting process (step S3 in FIG. 6), the CPU 201 first rotates (reverses) the roll R in the direction of the arrow C2 (step S11). Then, the rotation angle of the roll R at the start of the reverse rotation of the roll R is set to 0 degrees, and the output of the sensor unit 6 during the reverse rotation of the roll R and the feedback output of the roll drive motor are saved (step S12). The CPU 201 may, for example, rotate the roll R at a constant speed and store the sensor output at regular time intervals. Further, in order to more accurately identify the position of the tip portion of the sheet 1, the sensor output is saved in synchronization with the pulse of the roll rotation amount sensor 36 (see FIG. 5) output according to the rotation amount of the roll R. You may. In this case, it does not have to be constant on the rotating side of the roll R. As the sensor output, it suffices if data can be collected during one rotation of the roll R. However, in consideration of the slack of the sheet 1 when the roll R is set, the roll R is rotated by one rotation or more (in this example, one and a half rotations (720 degrees) or more), and data is collected ( Step S13).

After the data collection is completed, the CPU 201 stops the rotation of the roll R (step S14), and uses the feedback output data stored in the RAM 203 to correct the sensor output data also stored in the RAM (step S14). S15). The CPU 201 extracts the maximum value Hd and the minimum value Ld of the sensor output from the corrected sensor output data, and determines the H level and the L level of the sensor output based on the maximum value Hd and the minimum value Ld. The threshold value Td for this purpose is calculated, and the sensor output is determined as H level and L level (step S16). Here, as an example, the threshold value Td is advanced as an intermediate value between the maximum value Hd and the minimum value Ld.
The reason for setting the threshold value Td based on the sensor output data when the roll R is rotated in step 16 is that the light reflection characteristics differ depending on the type of sheet, and therefore the sensor output value of the sensor unit 6 fluctuates. This is because there is a risk.

The threshold value Td when the type of the sheet 1 is known or fixed may be a fixed value or may be set for each type of the sheet 1. Further, the value Td may be changed according to a high humidity environment in which the sheet 1 swells, a low temperature and low humidity environment in which the sheet 1 becomes firm, and the like. Further, the threshold value Td may be used as a plurality of values such as the threshold values THd1 and THd2 instead of one value. Td1 and Td2 are set as independent threshold values having hysteresis, and the change from the H level to the L level of the sensor output. Is determined using the threshold value THd1, and the change from the L level to the H level is determined using the threshold value THd2. It is possible to consider the noise fluctuation wn due to signal disturbance or the like.

After that, the CPU 201 analyzes the data of the sensor output stored in the RAM 203, and obtains the duration PL of the L level after changing from the H level to the L level (step S17). As the duration PL of the L level, the rotation angle of the roll R corresponding to the duration PL is calculated based on the output pulse of the roll rotation amount sensor 36 (see FIG. 5) or the data obtained at regular intervals. You may. When the sensor output changes a plurality of times so that there are a plurality of duration PLAs corresponding to the rotation angle A or more of the roll R as the duration PL of the L level, the CPU 201 sets the maximum duration PLAmax among them. Select (steps S18, S19).

After that, the CPU 201 specifies a separation position where the tip of the sheet 1 is peeled off from the surface of the roll R and separated (step S21). Specifically, as shown in FIG. 12D, the change point Pa of the sensor output immediately before the maximum duration PLAmax is specified. The change point Pa corresponds to a rotation position (separation position) when the tip portion 1 of the sheet 1 is peeled off from the surface of the roll R and separated. When there is only one duration PLA corresponding to the rotation angle A or more, the separation position of the tip portion of the sheet 1 is specified from the change point Pa of the sensor output immediately before the duration PLA (steps S19, S21). ).

After the separation position of the tip of the sheet 1 is specified in step S21, the CPU 201 reverses the roll R to the separation position in the direction of arrow C2 (step S22). As a result, the tip portion 1 of the sheet 1 is peeled off from the surface of the roll R and separated, and is located on the arm member 4 between the sensor unit 6 and the driven rotating body 8. Therefore, after that, by rotating the roll R in the forward direction to the arrow C1 (step S23), the tip end portion of the sheet 1 is automatically inserted and sent out into the sheet supply path between the arm member 4 and the separation flapper 10. Can be (automatic loading).

If it is determined in the previous step S20 that there is no duration PLA corresponding to the rotation angle A or more, the process proceeds to step S24. In step S24, the rotation of the roll R is stopped, the user is notified that the automatic loading could not be executed, and the user is manually operated to insert the tip end portion of the sheet 1 into the sheet supply path. To urge.

The processing of the flowchart of FIG. 11 will be specifically described with reference to the sensor output data of FIG.

First, the case of the sensor output data in the roll without bias shown in FIG. 8A will be described with reference to FIG. 12A. The normal sensor output is L level. The roll rotates and the tip of the sheet 1 passes through the contact position of the driven roller 10a of the separation flapper 10. Then, the tip end portion of the sheet 1 deviates from the contact position and starts peeling from the outer peripheral surface of the roll, and falls onto the arm member 4 due to its own weight and the returning force of the bent sheet. At this time, the outer surface of the sheet at the tip of the sheet 1 gradually approaches the detection position of the sensor unit 6, and the value of the sensor output increases (position 60 degrees from the start of rotation).

When the roll R is further rotated, the outer surface of the sheet at the tip of the sheet 1 passes the detection position on the sensor unit 6. Then, the strong reflected light on the outer surface of the sheet disappears, the weak reflected light from the surface of the roll R far away is received, and the sensor output sharply drops (decreases) from the H level to the L level (rotation angle 90 degrees). ). After that, when the roll R further rotates in the reverse direction, the tip of the sheet 1 reaches the contact position of the driven rotating body 8, and by continuing the rotation as it is, the tip of the sheet 1 comes into contact with the separation flapper 10 again. It will be repeated passing through the position.

The H level and the L level are obtained by dividing the output intensity of the sensor unit 6 into two levels. When the distance between the sensor unit 6 and the sheet 1 of the roll R is small, the H level is obtained, and when it is large, the L level is obtained. Become a level. The threshold TH as a boundary for dividing these levels is set as described above.

Therefore, if the maximum continuous section PLAmax of the L level is selected in this state and the separation position of the tip of the sheet 1 is specified from the change point Pa of the sensor output immediately before, the tip of the sheet is the angle of the position on the sensor. It becomes. Therefore, by aligning the positions and rotating the roll R in the forward direction to the arrow C1, the roll R can be fed into the seat supply path between the arm member 4 and the separation flapper 10.

However, in the case of the biased roll shown in FIGS. 8 (b) and 8 (c), the sensor output is affected by fluctuations in the sensor output when the roll as shown in FIG. 12 (b) is rotated. Therefore, the sensor output data that can be acquired is as shown in FIG. 12 (c).

In FIG. 12 (c), the normal sensor output is at the L level as in the case of FIG. 12 (a). The roll rotates and the tip of the sheet 1 passes through the contact position of the driven roller 10a of the separation flapper 10, starts peeling from the outer peripheral surface of the roll, and returns its own weight and the bent sheet onto the arm member 4. Will fall. The outer surface of the sheet at the tip of the sheet 1 moves closer to the detection position of the sensor unit 6, and the value of the sensor output increases (position 60 degrees from the start of rotation). When the roll R is further rotated, the tip of the sheet 1 passes the detection position on the sensor unit 6 and the sensor output sharply drops (decreases) from the H level to the L level (rotation angle 90 degrees). Up to this point, it is the same as in FIG. 12A, but when the H / L judgment is performed with the threshold value Td, the sensor output value that has dropped to the L level in FIG. The period of maintaining the above is extended, and the rotation angle when reaching the L level changes. Further, in FIG. 12A, even in the section where the L level is stable, the sensor output fluctuates and a section where the sensor output becomes the H level is created (a section of 240 degrees to 290 degrees).

When the maximum continuous section PLAmax of the L level is selected (290 degrees to 420 degrees) in the state of FIG. 12 (c) and the separation position of the tip of the sheet 1 is specified from the change point Pa of the sensor output immediately before, 290. It is judged to be the rotation position of the degree and tries to proceed to the seat supply operation, but since the position where the tip of the seat is different from the position near the top of the sensor, it enters the seat supply path between the arm member 4 and the separation flapper 10. It is not sent and automatic paper feeding fails.

Further, the influence of the fluctuation is slightly different, and even when PLAmax is selected in the range of 130 to 240 degrees, the position of Pa is deviated from the position where the tip of the seat passes over the sensor and passes the contact position of the driven rotating body 8. There is a possibility that it will end up. In that case, the tip of the sheet is not sent into the sheet supply path in the same manner, and automatic paper feeding fails.

Next, the data obtained by correcting the sensor output is viewed in FIG. 12 (d). First, the H / L determination is performed using the threshold value Td, and the maximum continuous section PLAmax is selected. Here, since the H section formed due to the influence of the roll bias in FIG. 12C disappears, the L section from the position where the sheet tip passes over the sensor is set as the maximum continuous section PLAmax. Therefore, the separation position of the tip portion of the sheet 1 is specified from the change point Pa of the sensor output immediately before, the position is aligned there, and the roll R is rotated in the forward direction, so that the sheet between the arm member 4 and the separation flapper 10 is specified. Can be sent within the supply path.

Although the tip of the sheet passes over the sensor due to the effect of the correction, the tip of the sheet passes through the contact position of the driven roller 10a and starts peeling from the outer peripheral surface of the roll (sensor of the sensor unit 6). The output value is the position where it increases (60 degrees from the start of rotation) and the position where the outer surface of the sheet at the tip of the sheet 1 passes the detection position on the sensor unit 6 and the sensor output decreases from the H level to the L level (rotation angle). Since it is between 90 degrees), it can be sent into the sheet supply path between the arm member 4 and the separation flapper 10 by adjusting to the corresponding position. Also, when aligning, the tip of the sheet is on the sensor due to the sensor configuration. May be shifted within the angle from the angle at which the tip passes to the contact position of the driven rotating body 8.

As described above, in the present embodiment, even when the output of the sensor unit 6 is affected by the fluctuation due to the roll bias, the tip portion of the sheet 1 is rolled R by correcting the sensor output based on the feedback output. It is possible to specify the rotation position (separation position) of the roll R when separating from the roll R. After that, the roll R is rotated in the reverse direction to the separated position, and then the roll R is rotated in the normal direction, so that the tip end portion of the sheet 1 can be automatically inserted into the sheet supply path and sent out.

(Second Embodiment)
13, FIG. 14, and FIG. 15 are explanatory views of a second embodiment of the present invention.

The output of the sensor unit 6 changes according to the distance facing the surface of the sheet 1 as in the above-described embodiment, and the sensor output and the feedback output of the roll drive motor are applied to the roll bias. Shall be correlated.

FIG. 13 is a flowchart for explaining the sheet tip setting process (automatic loading) in the present embodiment.

The process up to step S31 of the flowchart of FIG. 13 is the same as the flow up to step 14 of the flowchart of FIG. 11 described above.

After that, in step 31, the CPU 201 analyzes the feedback output data stored in the RAM 203 to determine whether the fluctuation range of the output value is equal to or greater than the predetermined value Gd (step S31). The predetermined value Gd for observing the range of fluctuation may be a fixed value when the type of the sheet 1 is known or fixed, or may be set for each type of the sheet 1. Further, the value Gd may be changed according to a high humidity environment in which the sheet 1 swells, a low temperature and low humidity environment in which the sheet 1 becomes firm, and the like.

When it is determined in the previous step S31 that the amplitude of the feedback output value exceeds the predetermined value Gd, the CPU 201 creates a correction switching value Kd from the sensor output data when it is determined that the fluctuation range is equal to or greater than the predetermined value. (Step S32). The correction switching value Kd is a value created based on the maximum value Hd and the minimum value Ld by extracting the maximum value Hd and the minimum value Ld of the sensor output, and the threshold value Td is a different value and corresponds to Kd> Td. To do. Here, as an example, the threshold value Td is advanced as an intermediate value between the maximum value Hd and the minimum value Ld as in the above-described embodiment. The reason for setting the correction switching value kd based on the sensor output data is that the light reflection characteristic differs depending on the type of sheet, and therefore the sensor output value of the sensor unit 6 may fluctuate. When the type of the sheet 1 is known or fixed, the correction switching value kd may be a fixed value or may be set for each type of the sheet 1. Further, the value kd may be changed according to a high humidity environment in which the sheet 1 swells, a low temperature and low humidity environment in which the sheet 1 becomes firm, and the like.

Next, the sensor output data having a correction switching value of kd or less is corrected by using the feedback output data stored in the RAM 203 (step S33). Then, complementation is performed by combining with the sensor output data having the correction switching value Kd or more that has been corrected, and the sensor output data used to specify the position of the sheet tip is created (step S34).

If it is determined in the previous step S31 that the amplitude of the feedback output value does not exceed the predetermined value Gd, the process proceeds to step S35. In step S35, the sensor output is not corrected and the acquired data is used as it is (step S35).

After step S34 or step 35, the process proceeds to S16 in FIG. H / L determination is performed from the creation of the threshold value Td, the maximum duration PLAmax of the L level is selected, and the separation position where the tip portion of the sheet 1 is peeled off from the surface of the roll R and separated from the change point Pa is specified. Then, the tip of the sheet 1 is automatically inserted into the sheet supply path at the tip of the sheet from the specified position and sent out (automatic loading).

The processing of the flowchart of FIG. 13 will be specifically described with reference to the sensor output and feedback output data of FIGS. 14 and 15.

First, FIG. 14A shows data when the fluctuation of the acquired feedback output is larger than the predetermined value Gd. In this case, the influence of fluctuations in the sensor output due to the bias of the roll is large, and the sensor output data is as shown in FIG. 14 (b) (equivalent to FIG. 12 (c)). If the sheet tip position is specified based on this output data, the tip position is mistaken and paper feeding fails as described in the first embodiment, so it is necessary to correct the sensor output.

Here, the correction switching value kd is created and applied before the correction is performed. The range of the output value of the correction switching value Kd or more is out of the range of correction execution, and the correction is performed in the range of the output value less than the correction switching value kd. The sensor output data shown in FIG. 14C can be obtained by combining the data in each range with and without correction. Compared with the sensor output data of FIG. 12 (d) in which the correction is performed without setting the correction range by the correction switching value Kd, the data is closer to the sensor output data of FIG. 12 (a) with no roll bias, and the accuracy of the correction is correct. Can be raised. When processing for specifying the sheet tip value is performed using this sensor output data, it is possible to suppress the deviation of the change point Pa as described in the first embodiment and specify the position where the sheet tip has passed over the sensor. You can.

Next, FIG. 15A shows data when the fluctuation of the acquired feedback output is smaller than the predetermined value Gd. In this case, the influence of fluctuations in the sensor output due to the bias of the roll is small, and the sensor output data as shown in FIG. 15B is obtained. Since the fluctuation of the sensor output due to the roll bias does not affect the H / L determination at the threshold value Td, the seat tip position can be specified without correcting the sensor output data. Therefore, the entire maintenance can be shortened by proceeding to the next step without performing the correction process.

As described above, in the present embodiment, when the amplitude of the feedback output is equal to or larger than a predetermined value, the accuracy of specifying the correction tip position can be improved by setting the periodic range of correction when performing data correction. it can.

In addition, when the amplitude of the feedback output is less than the predetermined value, the time required for the data correction processing is eliminated by not performing the correction processing because the influence of the roll bias on the sensor output is small, and the sheet automatic supply processing for the entire flow is performed. Time can be shortened.

(Modification example)
The sensor unit 6 is not limited to an optical sensor, and a distance sensor other than the optical sensor can be used as long as it is a sensor whose output value changes according to the distance to the outer surface of the seat to be detected. For example, a distance sensor such as an ultrasonic sensor or an electrostatic sensor that detects the distance to an object in a non-contact manner can also be used.

The printing device is not limited to a configuration including two sheet feeding devices corresponding to each of the two roll sheets, and may be configured to include one or three or more sheet feeding devices. Further, the printing device may be configured to print an image on a sheet supplied from the sheet feeding device, and is not limited to the inkjet printing device. Further, the printing method and configuration of the printing apparatus are also arbitrary. For example, a serial scan method in which an image is printed by repeating scanning of a print head and a sheet transport operation, or a sheet is continuously transported to a position facing a long print head to print an image. Any of the full line method may be used.

Further, the present invention can be applied to various sheet supply devices in addition to the sheet supply device that supplies a sheet as a print medium to the printing device. For example, it can be applied to a device that supplies a sheet to be read to a reading device such as a scanner or a copier, and a device that supplies a sheet-shaped processing material to a processing device such as a cutting device. Such a sheet feeding device can be configured separately from devices such as a printing device, a reading device, and a processing device, and may also include a control unit (CPU) for the sheet feeding device.

As described above, in the seat supply device, the driven rotating bodies 8 and 9 connected to the arm member 4 are pressed against the roll R from the lower side of the roll R, and the sensor unit 6 mounted on the arm member 4 is pressed. It is not limited to the configuration in which the position of the tip end portion of the roll R is detected by using the roll R.

The present invention can be widely applied as various sheet processing devices such as various sheet feeding devices including paper, film, cloth, etc., and printing devices and image reading devices including the feeding devices. The image reading device reads the recorded image of the sheet supplied from the feeding device by the reading head. Further, the sheet processing device is not limited to the printing device and the image reading device, and may be any device that performs various processing (processing, coating, irradiation, inspection, etc.) on the sheet supplied from the supply device. .. When the seat supply device is configured as an independent device, the device may be provided with a control unit including a CPU. Further, when the sheet processing device is provided with the sheet feeding device, at least one of the feeding device and the sheet processing device can be provided with a control unit including a CPU.

1 seat, 2 spool member, 3 drive unit, 3a rotary cam,
3b rotating shaft, 3c torsion coil spring, 4 arm member (moving body),
4a rotating shaft, 4b guide (lower guide), 5 arm rotating shaft,
6 Sensor unit (sensor), 6c light emitting part, 6d light receiving part,
7 swinging member, 7a bearing part, 7b shaft fastening part,
8 driven rotating body (contact body), 9 driven rotating body (contact body),
10 Separation flapper (upper guide), 10a driven roller,
10b Separation part, 10c Separation flapper lower surface,
11 Separation flapper rotating shaft, 12 Transport guide,
14 transport rollers, 15 nip rollers, 16 seat sensors,
17 platen, 18 printhead, 20 cutter,
28 operation panel, 29 external device, 32 roll sensor,
33 Roll drive motor, 34 Push pressure adjustment motor,
35 Motor for driving the transfer roller, 36 Roll rotation amount sensor,
100 printing device, 200 sheet feeding device, 201 CPU,
202 I / O interface, 203 RAM, 204 ROM,
205 external interface, 300 sheet carrier,
400 print section, R roll

Claims (8)

A driving means for rotating the roll on which the continuous sheet is wound in the first direction and the second direction opposite to the first direction,
Rotational phase control means that can grasp the rotation phase of the roll,
A sensor for detecting the peeling of the sheet from the roll and
Specific means for specifying the sheet peeling position and
A sheet supply device that feeds a sheet while rotating the roll in the first direction.
The sensor is provided at a position where the outer surface of the sheet peeled off from the outer circumference of the roll approaches, and the sensor output changes according to the distance to the outer surface of the sheet.
The drive means outputs feedback according to the drive control.
While rotating the roll in the second direction by the driving means, the sensor output and the feedback output are acquired.
Using the two acquired outputs, the sheet peeling position from the roll is specified by a specific means, and the sheet peeling position is specified.
The sheet feeding device is characterized in that the driving means changes the rotation direction of the roll from the second direction to the first direction after rotating to the peeling position. When the sheet tip portion of the roll having a contact body abutting on the outer circumference of the roll and rotating in the second direction passes through the position where the contact body abuts, the sheet tip portion is peeled off from the roll and said. The seat supply device according to claim 1, wherein the outer surface of the seat approaches the sensor. The seat supply device according to claim 1, wherein the drive means is a DC motor and the feedback is a load current value of the motor. The sheet according to claim 1, wherein in the specific means, the sensor output is corrected by using the feedback output, and the sheet peeling position from the roll is specified by a predetermined change in the corrected sensor output. Feeder. The sheet supply device according to claim 4, wherein the predetermined change is a change in which the sensor output changes from the threshold value or more to the threshold value or less with respect to the first threshold value. The sheet supply device according to claim 4, wherein the specific means determines whether the sensor output is equal to or higher than a second threshold value, and does not correct the sensor output in a range equal to or higher than the threshold value. In the specific means, it is determined whether the fluctuation of the feedback output is equal to or more than the third threshold value, and if it is equal to or less than the threshold value, the sensor output is not corrected, and a predetermined change is observed from the sensor output without correction. The sheet feeding device according to claim 1, wherein the peeling position is specified. A printing device comprising the sheet feeding device according to any one of claims 1 to 7, and a printing unit for printing an image on a sheet supplied from the sheet feeding device.

Images