JP2021042083A - Sheet feeder and printing equipment - Google Patents

Abstract

To accurately detect sheet peeling from a roll and perform automatic paper feeding.SOLUTION: In automatic roll feeding, sheet peeling is detected using a sensor provided at a position approached by an outer surface of a sheet peeled off from an outer circumference of a roll, with a sensor output changed according to a distance to the outer surface of the sheet. When the roll is rotated in a second direction and the sensor output changes as specified, the sheet is fed by changing a rotation direction of the roll to a first direction opposite to the second direction.SELECTED DRAWING: Figure 9

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 sheet tip is separated from the roll by its own weight.
It is detected by an optical sensor placed near the roll.

Japanese Unexamined Patent Publication No. 2011-37557

The 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. The signal intensity of the sensor output at this time is almost zero until the peeled sheet tip reaches the sensor optical axis, and the moment the sheet tip passes the sensor optical axis, it is pulsed due to the reflected light at the edge of the sheet tip. A signal is generated. After passing through the sensor optical axis, the sensor light hits the inner surface of the peeled sheet, but the sensor optical axis and the inner surface of the sheet are almost parallel and the distance suddenly increases, so the reflection intensity is weak and the signal after passing. The level drops sharply. In other words
The optical sensor of the patent document can basically discriminate only at the moment when the tip of the sheet passes through the optical axis of the sensor in the middle of peeling.

However, in an actual device, the behavior of sheet peeling from the roll is the rigidity of the sheet used (
The peeling speed (the speed at which the tip of the sheet moves) changes depending on various situations such as the return force that the bent sheet tries to return to its original state and the charge of static electricity. Therefore, in the form of detecting the sheet tip with a momentary signal pulse during peeling as in Patent Document 1, the generation timing of the signal pulse changes depending on the situation, and it may be difficult to detect the sheet peeling with high accuracy. And this timing deviation may hinder the subsequent sheet feeding operation. 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.

The sheet feeding device of the present invention includes a driving means for rotating a roll in a first direction for feeding a sheet from a roll formed by winding the sheet, a second direction opposite to the first direction, and the first. A detection means whose output changes according to the distance from the sheet of the roll rotating in two directions is provided, and after detecting the sheet tip portion of the roll by the output from the detection means, the driving means said the first. A sheet supply device that rotates a roll rotating in two directions in the first direction, and a change across a threshold value in an output from the detection means when the roll is rotating in the second direction. It is characterized in that the sheet tip portion of the roll is detected based on a section in which there is no change across the threshold value.

According to the present invention, it is possible to accurately detect the sheet peeling from the roll and perform automatic feeding.

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 1st Embodiment of this invention. It is a flowchart for demonstrating the sheet tip setting process. It is explanatory drawing of the change of the sensor output of the sensor unit in the 2nd Embodiment of this invention. It is explanatory drawing of the sensor output of a sensor unit. It is a flowchart for demonstrating the sheet tip setting process. It is a block diagram of the control system of the printing apparatus in 3rd Embodiment of this invention. It is explanatory drawing of the sensor output of a sensor unit. It is a flowchart for demonstrating the amplification factor adjustment process of a sensor. It is explanatory drawing of the deployment position of the sensor unit in 4th Embodiment of this invention. It is explanatory drawing of the relationship between the optical axis of a sensor unit and the outer peripheral surface of a roll. It is explanatory drawing of the structure of a sensor unit. It is explanatory drawing of the deployment position of the sensor unit in 5th Embodiment of this invention. It is explanatory drawing of the sensor output of the sensor unit in 6th Embodiment of this invention. It is explanatory drawing of the behavior of the tip part of a sheet. It is a flowchart for demonstrating the sheet tip setting process. It is explanatory drawing of the stop position of the tip part of the sheet in 7th Embodiment of this invention. It is a flowchart for demonstrating the sheet tip setting process. It is explanatory drawing of the other configuration example of a sheet feeding device.

Hereinafter, embodiments of 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, and the direction in which the sheet is conveyed in the printed portion 400 described later is Y.
The axial direction and the gravity direction are defined as 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. 2 corresponding to 2 rolls R
Two supply devices 200 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, a long print head 18 extending in a direction intersecting the transport direction of the sheet 1 is used.
An image is printed while continuously transporting 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, and a driven rotating body (
A contact body) 8, 9, a separation flapper (upper guide body) 10, and a flapper rotation shaft 11 are provided.

The transport guide 12 guides the sheet 1 to the printing unit 400 while guiding the front and back surfaces of the sheet 1 pulled out from the supply device 200. 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 sheet 1 pulled out from the roll R is formed on the upper portion of the arm member 4. The arm member 4 is located between the arm member 4 and the rotary cam 3a of the drive unit 3.
Is interposed in a torsion coil spring 3c that presses in the direction of arrow A1. 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 can be 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 the arrow A1 on the arm member 4.
It is changed according to the pressing force pressed in the direction.

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 swing member 7, and the swing member 7 is in the X-axis direction, Y.
It is supported by the rotating shaft 4a so as to have a stable posture in each of the axial direction and the Z-axis direction. 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. By pressing the driven rotating bodies 8 and 9 against 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. If you need to press the roll R even harder,
An urging force by an urging member such as a spring may be used. Roll R in the separation flapper 10
A driven roller 10a is rotatably provided at the contact portion with the seat 1 in order to suppress the influence of the pressing force on the sheet 1. Further, the separating portion 10b at the tip of the separating flapper 10 is a roll R.
It 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 of the sheet.

The sheet 1 is pulled out from the roll R by passing over the driven rotating bodies 8 and 9, 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, sheet 1
The sheet 1 can be smoothly supplied by utilizing its own weight. 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 device, the device 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 separated from the arm member 4 and the separated flapper 10.
It is automatically inserted and sent out in the sheet supply path between and. 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 always 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 smaller, 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 a 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. The CPU 201 is the RAM 203.
On the other hand, information about the sheet 1 and the like are written and read. The motor 33
It is a roll drive motor for rotating the roll R forward and reverse via the spool member 2, and constitutes a drive mechanism (rotation mechanism) capable of rotationally driving the roll R. 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. 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, and is, for example, a rotary encoder that outputs a number of pulses corresponding to the rotation amount of the roll R.

<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. CPU2
In 01, after the roll R is set, the arm member 4 is switched to a state of pressing in the direction of arrow A1 (strong nip state) by "pressing pressure of strong nip" (step S2). Then C
The PU 201 executes a sheet tip setting process of setting the tip of the sheet 1 in the sheet 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 transported (obliquely skewed) in the sheet transport unit 300 while being tilted 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. Then CP
The U201 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.

Hereinafter, as an embodiment of the present invention, the sheet tip setting process (step S20) of FIG. 5 in such a basic configuration of the printing apparatus 100 will be described.

(First Embodiment)
In the present embodiment, as the sensor unit 6, an optical sensor whose output changes according to the distance facing the surface (outer surface) of the sheet 1 is used. Then, after detecting that the tip end portion of the sheet 1 is peeled off from the outer peripheral surface of the roll R and separated based on the change in the output of the sensor unit 6 during the rotation in the opposite direction of the roll R (direction of arrow C2), the roll is rolled. The sheet 1 is supplied by rotating R in the forward direction of the arrow C1.

As shown in FIG. 7, the sensor unit 6 of this example includes 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 light receiving unit 6
The output value of b increases as the distance (interval) 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.

8 and 9 are explanatory views of a sheet tip setting process (step S3 in FIG. 6) using the sensor unit 6. As mentioned above, sheet tip setting processing (automatic loading)
Is a process of automatically inserting the tip of the sheet 1 of the roll R into the sheet supply path between the arm member 4 and the separation flapper 10 after the roll R is set and sending it out. The arm member 4 faces the surface of the sheet 1 (outer surface of the sheet), and the separation flapper 10 is the sheet 1.
Facing the back surface (inner surface of the sheet).

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. CP
After the roll R is set, the U201 switches to a state in which the arm member 4 is pressed in the direction of 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, the roll R is rotated (reverse rotation) in the opposite direction of the arrow C2 (step S11). Then, during the reverse rotation of the roll R, the output (sensor signal level) of the detection signal of the sensor unit 6 becomes H.
It is determined whether or not the change has changed from within the level range (within the first level range) to within the range of the L level (within the second level range) (step S12).

FIG. 9A is an explanatory diagram of an example of the waveform of the sensor output, and the rotation angle of the roll R at the start of the reverse rotation of the roll R is set to 0 degree. Normally, the sensor output is L level. Roll R
As shown in FIG. 9 (b), the sensor output is increased as shown in FIG. 9 (a) as the outer surface of the sheet at the tip of the sheet 1 approaches the detection position of the sensor unit 6 when the is rotated 170 degrees in the reverse direction. L
Increases (increases) from level to H level.

More specifically, when the roll R rotates 170 degrees in the reverse direction, the tip end portion 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, as shown in FIG. 9B, the movement of the seat is such that the outer surface of the seat at the tip of the seat 1 gradually approaches the detection position of the sensor unit 6. Further, when the roll R rotates in the reverse direction by 200 degrees, the outer surface of the sheet at the tip of the sheet 1 passes the detection position on the sensor unit 6 as shown in FIG. 9C. 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. After that, when the roll R further rotates in the reverse direction by an angle θ, the tip end portion of the sheet 1 reaches the contact position of the driven rotating body 8. 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 value TH as a boundary for dividing these levels is set in advance and stored in the printer main body or the non-volatile memory inside the sensor unit 6. The threshold value TH is set based on the sensor outputs L0 and H0. That is, the roll R is rotated one or more times (for example,
It is set based on the value between the minimum level and the maximum level of the sensor output when rotated (multiple times). For example, when the minimum level sensor output is L0 and the maximum level sensor output is H0, the threshold value TH is an intermediate value between these sensor outputs L0 and H0 (TH = (H0 +).
It can be set as L0) / 2). Since the threshold value TH fluctuates due to variations in the sensor units 6, it is desirable to measure the sensor outputs L0 and H0 for each sensor unit 6 and set the threshold value TH based on the measured values.

As described above, the sensor output increases in response to the movement of the outer surface of the sheet peeled off from the roll R to approach the detection position of the sensor. Then, the sensor output decreases in response to the movement of the outer surface of the seat away from the detection position of the sensor due to the subsequent rotation of the roll in the second direction. By capturing such a change in sensor output (predetermined change), it is possible to accurately obtain the timing when the sheet peeled from the roll reaches the guide surface and the sheet peeling is completed.

As shown in FIG. 9B, when the tip portion 1 of the sheet 1 passes through the sensor unit 6, the sensor output changes from the H level to the L level, and then the L level of the sensor output continues for a certain period of time. Stops the rotation of the roll R (steps S13 and S14). Specifically, after the sensor output changes from the H level to the L level, it is determined whether or not the sensor output continues the L level for a certain period in which the roll R rotates in the reverse direction by a certain angle A. Stops the rotation of the roll R when The constant angle A is an angle smaller than the angle θ, and in the case of this example, it is an angle (A = θ / 2) that is half of the angle θ. When the rotation of the roll R is stopped in step S14, the tip end portion of the seat 1 is located on the arm member 4 between the sensor unit 6 and the driven rotating body 8. Therefore, after that, the roll R is changed to the arrow C1.
By rotating forward (step S15), the tip of the sheet 1 can be automatically inserted and sent out into the sheet supply path between the arm member 4 and the separation flapper 10 (automatic loading).

If the sensor output does not change from the H level to the L level even if the roll R rotates in the reverse direction for one round or more (a predetermined amount of 360 degrees or more), the process proceeds from step S16 to step S17. Further, even if the roll R does not continue the L level of the sensor output for a certain period of time even if the roll R rotates in the reverse direction by a predetermined amount of one round or more, the process proceeds from step S16 to step S17. If the tip of the sheet 1 is not separated from the outer peripheral surface of the roll R during one rotation of the roll R, it is considered that the roll R is poorly peeled from the outer peripheral surface. If the tip of the sheet 1 separated from the outer peripheral surface of the roll R does not separate from the top of the sensor unit 6 during one rotation of the roll R, the peeled sheet causes a paper jam on the sensor. it is conceivable that. In either case, automatic paper feeding cannot be performed. In step S17, the rotation of the roll R is stopped and automatic loading (
The user is notified that the automatic paper feeding could not be executed, and the user is urged to perform a manual operation (manual paper feeding) for inserting the tip end portion of the sheet 1 into the sheet supply path. After inserting the sheet tip, the user instructs the device to feed the paper. Based on this instruction, the roll R starts rotating in the positive direction to feed the inserted sheet into the apparatus. As described above, in the present embodiment, after the roll R is set, the tip end portion of the sheet 1 can be automatically inserted into the sheet supply path and sent out. Therefore, after setting the role R, the user
It is not necessary to manually insert the tip of the sheet 1 into the sheet supply path, and the work load when setting the roll R is reduced.

(Second embodiment)
10 and 11 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. For example, in the case of the sheet 1 having a large acupuncture point and the sheet 1 having a high rigidity, when the roll R is rotated in the reverse direction in the direction of the arrow C2, the tip portion 1 of the sheet 1 passes through the driven rotating body 9 and then driven. The sensor output may change in the period until it passes through the roller 10a. That is, during that period, the output of the sensor unit 6 may temporarily rise from the L level to the H level and then return to the L level.

FIG. 10 shows the sensor unit 6 when the roll R of the sheet 1 having a large pot amount is rotated in the reverse direction.
It is explanatory drawing of the output waveform of, and the behavior of the tip portion of the sheet 1. When the roll R starts reverse rotation in the direction of arrow C2 from the state where the tip end portion of the sheet 1 is near the driven roller 10a and rotates about 45 degrees from the rotation start position, the above-mentioned FIG. 9B shows. As described above, the tip portion 1 of the sheet 1 passes through the driven roller 10a and falls onto the arm member 4. As a result, FIG. 10 (a)
As described above, when the rotation angle of the roll R is around 45 degrees, the output of the sensor unit 6 rises from the L level to the H level. After that, when the roll R rotates about 90 degrees from the rotation start position, the tip portion 1 of the sheet 1 passes over the upper part of the sensor unit 6 as shown in FIG. 9C described above. As a result, as shown in FIG. 10A, when the rotation angle of the roll R is around 90 degrees,
The output of the sensor unit 6 drops from the H level to the L level.

Further, when the roll R continues to rotate in the reverse direction and rotates about 270 degrees from the rotation start position, the tip portion of the sheet 1 is located above the roll R, and the weight of the tip portion 1 causes as shown in FIG. 10 (b). The sheet 1 may be bent. When such bending occurs, FIG. 10 (b)
), The outer surface of the sheet 1 approaches the sensor unit 6. As a result, FIG. 10 (a)
), The output of the sensor unit 6 is L when the rotation angle of the roll R is around 270 degrees.
Raises from level to H level. After that, when the roll R further rotates in the reverse direction, the bent portion of the sheet 1 is wound around the roll R as shown in FIG. 10C, and the sheet 1 is separated from the sensor unit 6. As a result, as shown in FIG. 10A, the rotation angle of the roll R is 350.
The output of the sensor unit 6 returns from the H level to the L level in the vicinity of the degree.

When the reverse rotation of the roll R is continued, such a change in the output of the sensor unit 6 is repeated. In the present embodiment, even when the sensor output changes in this way, the position of the tip portion of the sheet 1 is specified, and the tip portion is automatically placed in the seat supply path between the arm member 4 and the separation flapper 10. Can be inserted and sent out (sheet tip set processing)
..

FIG. 11 is a flowchart for explaining the sheet tip setting process (automatic loading) in the present embodiment.

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). After the roll R is set, the CPU 201 presses the arm member 4 in the direction of arrow A1 by "pressing pressure of strong nip" (a state in which the arm member 4 is pressed in the direction of arrow A1.
Switch to the strong nip state) (step S2 in FIG. 6).

In the sheet tip setting process (step S3 in FIG. 6), the CPU 201 has a roll R.
Is rotated (reverse rotation) in the opposite direction of the arrow C2 (step S21), and the sensor output is saved (step S22). 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 roll rotation amount sensor 36 (FIG. 5) is output according to the rotation amount of the roll R.
The sensor output may be saved in synchronization with the pulse (see). 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 sea and the slack of 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 (540 degrees) or more) to collect data. (Step S23).

The CPU 201 stops the rotation of the roll R after the data collection is completed (step S24).
), The maximum value Hd and the minimum value Ld of the sensor output are extracted from the sensor output data stored in the RAM 203 (step S25). After that, it is determined whether or not the difference (Hd-Ld) between the maximum value Hd and the minimum value Ld exceeds the value (THa) required for specifying the position of the tip portion of the sheet 1 (step S26). ). The threshold THa may be a fixed value.
Alternatively, it may be set for each type of sheet 1. Further, the value THa 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 the difference (Hd-Ld) exceeds the value (THa), the CPU 201 determines the maximum value Hd.
And the threshold value THd for determining the H level and L level of the sensor output based on the minimum value Ld.
1 and THd2 are calculated (steps S26, S27). Thresholds THd1 and THd2
Is set as an independent threshold value having hysteresis in consideration of the noise fluctuation amount wn due to signal disturbance or the like. 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. in this way,
Thresholds THd1 and THd2 based on the sensor output data when the roll R is rotated.
The reason for setting is that the light reflection characteristic differs depending on the type of sheet, and therefore the value of the sensor output of the sensor unit 6 may fluctuate. When specifying the position of the tip of a known sheet, the values stored in ROM204 (see FIG. 5) in advance may be set as the threshold values THd1 and THd2. When the SN ratio of the acquired maximum value Hd and minimum value Ld is sufficiently large, the maximum value is used as a threshold value for determining the change from the H level to the L level and the change from the L level to the H level of the sensor output. A single value in between Hd and the minimum value LdHd may be set.

After that, the CPU 201 analyzes the data of the sensor output stored in the RAM 203, and based on the data for one round of the roll R, the L after changing from the H level to the L level.
Find the duration PL of the level (step S28). 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 S29 and S30). After that, the CPU 201
As shown in FIG. 9B described above, the separation position where the tip end portion of the sheet 1 is peeled off from the surface of the roll R and separated is specified (step S31). Specifically, as shown in FIG. 10A, the change point Pa of the sensor output immediately before the maximum duration PLAmax is specified. The change point Pa
Corresponds to the 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 as shown in FIG. 9B described above. Duration PLA corresponding to rotation angle A or higher
If there is only one, the change point Pa of the sensor output immediately before the duration PLA
From the above, the separation position of the tip portion of the sheet 1 is specified (steps S32 and S33).

After the separation position of the tip of the sheet 1 is specified in step S31 or S33, C
PU201 reverses the roll R in the direction of arrow C2 to the separated position (step S34).
). As a result, the tip portion 1 of the sheet 1 is peeled off from the surface of the roll R and separated as shown in FIG. 9B described above, and is located on the arm member 4 between the sensor unit 6 and the driven rotating body 8. .. Therefore, by subsequently rotating the roll R in the forward direction to the arrow C1 (step S35), the sheet 1 is placed in the sheet supply path between the arm member 4 and the separation flapper 10.
The tip of the can be automatically inserted and sent out (automatic loading).

When it is determined in the previous step S26 that the difference (Hd-Ld) does not exceed the threshold value THa, and when it is determined in the previous step S22 that there is no duration PLA corresponding to the rotation angle A or more. To step S36. In step S36, 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.

As described above, in the present embodiment, even when the output of the sensor unit 6 temporarily fluctuates, the tip portion of the sheet 1 is separated from the roll R based on the sensor output when the roll R is rotated in the reverse direction. The rotation position (separation position) of the roll R can be specified. 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.

(Third Embodiment)
FIG. 12 is a block diagram of the control system according to the third embodiment of the present invention. The sensor unit 6 is a sensor whose output changes according to the distance between the rolls R and the surface of the roll R, as in the first embodiment described above. In the present embodiment, the LED driver 6e with a dimming function under the control of the CPU 201 is connected to the light emitting unit 6c of the LED, and by adjusting the current flowing through the light emitting unit 6c, the light emitting unit 6c emits light. The intensity amplification factor can be changed. A current-voltage conversion circuit 6h and an amplifier circuit 6i are connected to the light receiving unit 6d of the photodiode, and the light receiving sensitivity of the light receiving unit 6d is amplified by adjusting the resistance value of the digital potential meter 6f under the control of the CPU 201. You can change the rate. Further, the sensor unit 6 is provided with the amplification factor of the sensor unit 6 (the amplification factor of the light emission intensity of the light emitting unit 6c, and the light receiving unit 6).
In order to store the amplification factor of the light receiving sensitivity of d) and the like, an EEPROM 6 g of a non-volatile memory is provided.

FIG. 13 is an explanatory diagram of the output waveform of the sensor unit 6 when the roll R is rotated in the reverse direction. When the maximum value Hd of the sensor output of the sensor unit 6 becomes larger than the upper limit determination value THmax, the sensor output may be saturated. When the minimum value Ld of the sensor output of the sensor unit 6 becomes smaller than the lower limit determination value THmin, the sensitivity of the sensor unit 6 may not be sufficient. Further, when the difference between the maximum value Hd and the minimum value Ld is less than a predetermined value, the sensor output may be affected by steady noise, and it may be difficult to detect the position of the tip portion of the sheet 1. Therefore, a determination value for determining whether or not the difference between the maximum value Hd and the minimum value Ld is sufficient is also set.

In this embodiment, the same sheet tip setting process (automatic loading) as in the above-described embodiment is performed.
In the initial stage of, the roll R is rotated in the reverse direction, and the amplification factor of the sensor unit 6 is adjusted based on the output of the detection signal (sensor output) of the sensor unit 6 at that time.

FIG. 14 is a flowchart for explaining an amplification factor adjusting process for adjusting the amplification factor (sensor amplification factor) of the sensor unit 6.

First, the CPU 201 initializes the data processing area to secure an area for processing the output data of the sensor unit 6 (step S41), and then sets the initial value of the amplification factor of the sensor (step S42). The amplification factor of the sensor adjusted by the previous amplification factor adjustment process is stored in EEPROM 6g, and the stored amplification factor is set as an initial value. If the amplification factor is not preserved, a predetermined amplification factor is set as the initial value. In that case, the initial value of the amplification factor may be set according to the type, winding diameter, width, etc. of the roll R input in advance by the operation panel 28. The winding diameter and width of the roll R may be set in the main body of the printing device, or may be set by a driver in a terminal such as a personal computer connected to the printing device by wire or wirelessly. further,
The temperature / humidity sensor may be provided, and the initial value of the amplification factor may be set according to the environmental temperature and the environmental humidity when the roll R is set.

Next, the CPU 201 rotates the roll R one or more turns in the direction of the arrow C2 to acquire the sensor output at that time (step S43), and obtains a moving average for each predetermined rotation angle of the roll R from the sensor output. (Step S44). In the case of this example, the sensor output for two rotations of the roll R is acquired, and the moving average is calculated for each predetermined rotation angle of the roll R. The maximum value Hd and the minimum value Ld of the moving averaged data are extracted (step S45), and it is determined whether or not the maximum value Hd is equal to or greater than the upper limit determination value THmax in FIG. 13 (step S46). When the maximum value Hd is equal to or higher than the upper limit determination value THmax, the CPU 201 determines whether or not the amplification factor of the emission intensity of the light emitting unit 6c is within a predetermined range (within the first allowable range) (step S47). And CPU2
In 01, when the amplification factor of the light emitting intensity of the light emitting unit 6c is within the predetermined range, the amplification factor of the light emitting intensity is lowered (step S48), and when it is outside the predetermined range, the amplification factor of the light receiving intensity of the light receiving unit 6d is amplified. Decrease the rate (step S49). This makes it possible to avoid a situation in which the sensor output is saturated.

On the other hand, when the maximum value Hd is less than the upper limit determination value THmax, the CPU 201 has a minimum value L.
It is determined whether or not d is less than the lower limit determination value THmin (step S50). CPU 20
In step 1, when the minimum value Ld is less than the lower limit value determination value THmin, it is determined whether or not the amplification factor of the emission intensity of the light emitting unit 6c is within a predetermined range (step S51). And the CPU 201
When the amplification factor of the light emitting intensity of the light emitting unit 6c is within the predetermined range, the amplification factor of the light emitting intensity is increased (step S52), and when it is outside the predetermined range, the amplification factor of the light receiving intensity of the light receiving unit 6d is increased. (Step S53). As a result, the detection sensitivity of the sensor unit 6 can be increased.

Further, when the minimum value Ld is equal to or greater than the lower limit value determination value THmin, the CPU 201 determines whether or not the difference (Hd−Ld) between the maximum value Hd and the minimum value Ld is less than a predetermined determination value ( Step S51). If the difference (Hd-Ld) is less than a predetermined determination value, the sensor output may be affected by steady noise, making it difficult to detect the position of the tip of the sheet 1. In this case, the process proceeds from step S4 to step S51 in order to increase the amplification factor of the light emission intensity or the light reception intensity of the sensor unit 6. When the difference (Hd-Ld) is equal to or greater than a predetermined determination value, it is determined that the amplification factors of the light emission intensity and the light reception intensity of the sensor unit 6 have been appropriately adjusted, and the amplification factor adjustment process is terminated.

After adjusting the amplification factors of the emission intensity or the light reception intensity in the previous steps 48, S49, S52, and S53, the CPU 201 determines whether or not those amplification factors are within a predetermined range (step S55). ). That is, it is determined whether or not the emission intensity is within the predetermined range (within the first allowable range) and the light receiving intensity is within the predetermined range (within the second allowable range). When the amplification factors of the light emission intensity and the light reception intensity are within the predetermined ranges, the process returns to the previous step S41 in order to reconfirm whether or not the amplification factors are appropriate. If the amplification factors of the emission intensity and the light reception intensity are not within the predetermined range, it is determined that the amplification factor has exceeded the adjustment limit, and error processing such as outputting an error display is executed. When the amplification factors of the emission intensity and the light reception intensity are within the predetermined range, the number of times the amplification factors are increased or decreased in steps 48, S49, S52, and S53 is counted, and the count value is constant. Error handling may be executed when there are more than a few.

As described above, in the present embodiment, the output of the sensor unit 6 is output by adjusting the amplification factor of the light emission intensity and the light reception intensity of the sensor unit 6 based on the sensor output when the roll R is rotated in the reverse direction by one or more rotations. Can be optimized. Therefore, the positions of the tip portions of various sheets 1 having different reflectances and the like can be reliably specified.

(Fourth Embodiment)
15 to 17 are diagrams for explaining a fourth embodiment of the present invention.

FIG. 15 is a diagram for explaining the position of the sensor unit 6 arranged on the arm member of the seat supply device 200, and in FIG. 15A, a roll R having a large winding diameter is set.
In FIG. 15B, a roll R having a small winding diameter is set. In the present embodiment, the sensor unit 6 is arranged so as to satisfy the positional relationship of the following formula (1) regardless of the winding diameter of the roll R as shown in FIGS. 15A and 15B. In addition, sheet 1 on a tube such as a paper tube
When the roll R is formed by winding the roll R, even when only the tube such as the paper tube is set and the roll R has the minimum winding diameter, the following equation (1) The positional relationship is established.
α> β (α1> β1, α2> β2) ・ ・ ・ (1)

In FIG. 15A, the position P1 where the roll R and the separation flapper 10a are in contact (the contact position of the upper guide with respect to the roll R) and the position P2 where the roll R and the rotation driven body 8 are in contact (the lower guide with respect to the roll). The distance between the contact position) and is α1. In addition, FIG. 15 (b)
Let α2 be the distance between the position P1 and the position P2 in. These distances α1 and α1 are collectively referred to as distance α. Further, in FIG. 15A, the detection position and the position P of the sensor unit 6
The distance between 2 and β1 is defined as β1, and in FIG. 15B, the distance between the detection position of the sensor unit 6 and the position P2 is β2. These distances β1 and β1 are collectively referred to as distance β.
The detection position of the sensor unit 6 is the position of the detection unit of the sensor unit 6 that can detect the position of the tip portion, and corresponds to, for example, the positions of the light emitting unit 6c and the light receiving unit 6d.

As described above, the sensor unit 6 satisfies the condition that the distance β1 is smaller than the distance α1 as shown in FIG. 15A and the distance β2 is smaller than the distance α2 as shown in FIG. 15B. It is deployed at a position on the arm member. That is, regardless of the winding diameter of the roll R, α
The deployment position of the sensor unit 6 is set so as to satisfy the relationship of> β.

FIG. 16 is an explanatory view of the light emitting optical axis of the light emitting unit 6c in the sensor unit 6, and FIG. 16 (FIG. 16)
In a), a roll R having a large winding diameter is set, and in FIG. 16B, a roll R having a small winding diameter is set. The angle γ1 between the light emitting light axis I1 of the light emitting unit 6c and the vector Q1 in FIG. 16A and the angle γ2 between the light emitting light axis I2 and the vector Q2 of the light emitting unit 6c in FIG. Satisfy the relationship of (2).
0 ° <γ (γ1, γ2) <90 ° ・ ・ ・ (2)

The vector Q1 is a vector that points in the normal rotation direction (arrow C1 direction) of the roll R along the tangent line at the intersection P3 of the optical axis I1 and the roll R. Similarly, the vector Q2 is a vector that points in the forward rotation direction of the roll R along the tangent line at the intersection P3 between the optical axis I2 and the roll R. The optical axes I1 and I2 are collectively referred to as the optical axis I, and the vectors Q1 and Q2 are collectively called the vector Q.
Also, the angles γ1 and γ2 are collectively referred to as the angle γ.

In this way, in the sensor unit 6, the angle γ (γ1, γ2) formed by the virtual line extending the optical axis I (I1, I2) inside the roll R and the vector Q (Q1, Q2) becomes an acute angle. It is arranged like this.

FIG. 17 is an explanatory diagram of the arrangement relationship between the light emitting unit 6c and the light receiving unit 6d in the sensor unit 6. FIG. 17A is a view of a main part of the sheet supply device 200 as viewed from the X-axis direction, and FIG. 1A is a view.
FIG. 7 (b) is a view of the view from the Z-axis direction.

In the present embodiment, the light emitting unit 6c and the light receiving unit 6d are arranged side by side in the axial direction (X-axis direction) of the roll R. By arranging the light emitting unit 6c and the light receiving unit 6d next to each other in the axial direction of the roll R, the light emitting optical axis of the light emitting unit 6c and the light receiving optical axis of the light receiving unit 6d are substantially opposed to each other in the axial direction of the roll R. By arranging the light emitting unit 6c and the light receiving unit 6d in this way, the roll R
Regardless of the winding diameter of the sensor unit 6, the facing distance between the tip of the sheet 1 and the sensor unit 6 can be detected. That is, when the tip of the sheet 1 passes through the driven roller 10a of the separation flapper and falls on the arm member 4 by its own weight due to the reverse rotation of the roll R, the position of the tip of the sheet 1 can be detected. ..

Further, by setting the angle γ to an acute angle, due to the reverse rotation of the roll R, the emitted light is emitted between the time when the tip portion 1 of the sheet 1 falls on the arm member 4 by its own weight and the time when it passes over the sensor unit 6. There is a state in which the axis I and the surface of the tip of the sheet 1 are at right angles. That is, between the time when the tip of the sheet 1 passes through the driven roller 10a of the separation flapper and the time when the tip of the sheet 1 falls on the arm member 4 by its own weight, at least temporarily, the light emitting optical axis I and the tip of the sheet 1 The surface is at right angles. In such a state of being at right angles, the reflected light emitted from the light emitting portion 6c and reflected on the surface of the tip portion of the sheet 1 is regarded as the strongest specular reflected light in the light receiving portion 6.
Detected by d. Further, by setting the angle formed by the surface of the arm member 4 on which the tip of the sheet 1 falls and the light emitting light axis I at 90 degrees, the tip of the sheet 1 is formed along the surface of the arm member 4. When this happens, the emission light axis I and the surface of the tip of the sheet 1 are at right angles.

As described above, there is a state in which the light receiving portion 6d receives the strongest specular reflected light between the time when the tip portion 1 of the sheet 1 falls on the arm member 4 by its own weight and the time when it passes over the sensor unit 6.
Therefore, when the tip 1 of the seat 1 falls on the arm member 4 by its own weight, the sensor output of the sensor unit 6 becomes H level more reliably, and the sensor output required to specify the position of the tip of the seat 1 is obtained. It can be obtained more reliably.

Further, the light emitting unit 6c and the light receiving unit 6d are arranged so as to be arranged in the axial direction of the roll R so that the light emitting optical axis and the light receiving optical axis are substantially opposed to each other. As a result, it is possible to minimize the influence of the type of the sheet 1, the change in the winding diameter of the roll R, the change in the behavior of the tip portion of the sheet 1, and the like on the sensor output. Further, in a series of sensor outputs, the ratio of the sensor output when the light receiving unit 6d receives the specular reflected light can be increased, and the noise due to the influence of the external light can be suppressed to be small. what if,
When α <β, γ> 90 ° without satisfying the relationship of the above equations (1) and (2), the optical axis of the sensor unit 6 always faces the separation flapper 10 and the tip of the sheet 1 It becomes impossible to acquire the sensor output according to the facing interval with.

The deployment position of the sensor unit 6 is not specified only for the arm member, and may be deployed at a position other than the arm member in consideration of the optical characteristics of the sensor unit 6 and the like.

(Fifth Embodiment)
FIG. 18 is an explanatory view of the configuration of the sheet supply device 200 according to the fifth embodiment of the present invention. In FIG. 18A, a roll R having a large winding diameter is set, and in FIG. 18B, winding is performed. A roll R having a small diameter is set.

In the present embodiment, the relationship between the vector W (W1, W2) that points in the normal rotation direction of the roll R along the tangent line at the contact point between the roll R and the rotation driven body 8 and the arm member 4 is specified. .. That is, the supply device 200 is configured so that the intersection P4 between the vector W (W1, W2) and the surface of the arm member 4 exists regardless of the winding diameter of the roll R. Also,
This intersection P4 is the intersection P5 between the light emitting optical axis I of the sensor unit 6 and the surface of the arm member 4.
It is located on the upstream side (left side in FIG. 18) of the sheet 1 in the transport direction.

By configuring the supply device 200 in this way, when the roll R is rotated forward in the direction of the arrow C1 to convey the sheet 1, the tip end portion of the sheet 1 moves toward the arm member 4 along the vector W. .. Therefore, the tip end portion of the sheet 1 is conveyed while being in contact with the arm member 4 regardless of the winding diameter of the roll R. Further, since the intersection P4 is located on the upstream side of the intersection P5 in the transport direction, the tip of the sheet 1 is the sensor unit 6 in the transport process of the tip of the sheet 1 regardless of the winding diameter of the roll R. Pass over. Therefore, the sensor unit 6 can more reliably detect the facing distance from the tip end portion of the sheet 1 regardless of the winding diameter of the roll R.

(Sixth Embodiment)
19 and 21 are explanatory views of a sixth embodiment of the present invention. FIG. 19A is an explanatory diagram of the output waveform of the sensor unit 6. FIG. 19B is an explanatory view of a state in which the tip end portion of the sheet 1 is normally peeled off from the surface of the roll R, and FIG. 19C is an explanatory view of the sheet 1 from the surface of the roll R due to the influence of static electricity or the like. It is explanatory drawing of the state in which the peeling amount of the tip portion of is smaller than the normal state. 20 (a), (b), and (c) show the roll R arrow C from the state of FIG. 19 (c).
It is explanatory drawing when it is rotated forward in one direction. FIG. 21 is a flowchart for explaining the sheet tip setting process (automatic loading) in the present embodiment.

When the tip end portion of the sheet 1 is normally peeled off from the surface of the roll R as shown in FIG. 19B, the sensor output of the sensor unit 6 changes as shown in the waveform W1 in FIG. 19A. That is, when the tip of the sheet 1 is in the vicinity of the driven roller 10a, the roll R starts to reverse in the arrow C2 direction, and when the roll R rotates about 45 degrees, the tip of the sheet 1 moves to the driven roller 1.
It passes through 0a and falls. As a result, the sensor output changes from the L level to the H2 level.
Further, when the roll R starts rotating and then rotates about 90 degrees, the tip of the sheet 1 passes over the upper part of the sensor unit 6 as shown in FIG. 19B, so that the sensor output becomes H.
It changes from level to L level. After that, by rotating the roll R in the normal direction in the direction of the arrow C1, the tip end portion of the sheet 1 can be automatically inserted into the sheet supply path and sent out.

On the other hand, when the peeling amount of the tip portion of the sheet 1 is smaller than that in the normal state as shown in FIG. 19 (c), the sensor output of the sensor unit 6 changes as shown in the waveform W2 in FIG. 19 (a). .. That is, when the tip of the sheet 1 is in the vicinity of the driven roller 10a, the roll R starts to reverse in the arrow C2 direction, and when the roll R rotates about 45 degrees, the tip of the sheet 1 moves to the driven roller 1.
It passes through 0a and falls. Further, when the roll R starts rotating and then rotates about 90 degrees, the tip of the sheet 1 passes over the upper part of the sensor unit 6 as shown in FIG. 19C, so that the sensor output becomes H level. Changes from to L level. After that, when the roll R is rotated in the normal direction in the direction of the arrow C1, the amount of peeling at the tip of the sheet 1 is small as shown in FIG. 20 (a).
As shown in FIG. 20 (b), the tip end portion of the sheet 1 may collide with the driven roller 10a, and the sheet 1 may be jammed as shown in FIG. 20 (c).

The sheet tip setting process (automatic loading) of FIG. 21 in the present embodiment suppresses the occurrence of such jam. The same steps as those in the flowchart of FIG. 8 of the above-described embodiment are designated by the same step numbers, and the description thereof will be omitted.

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). After the roll R is set, the CPU 201 presses the arm member 4 in the direction of arrow A1 by "pressing pressure of strong nip" (a state in which the arm member 4 is pressed in the direction of arrow A1.
Switch to the strong nip state) (step S2 in FIG. 6).

In the sheet tip setting process, the CPU 201 rotates (reverse rotation) one or more rotations (reverse rotation) of the roll R in the opposite direction of the arrow C2 (step S11).

The CPU 201 obtains a change amount (level change amount) when the sensor output of the sensor unit 6 changes from the H level to the L level when the roll R rotates in the reverse direction, and the level change amount is a predetermined threshold value ΔH1 (= H1-). It is determined whether or not it is larger than L) (step S61). Roll R
When the level change amount does not become larger than the predetermined threshold value ΔH1 (= H1-L) even if it rotates in the reverse direction for one or more rotations, it is determined that the tip of the sheet 1 has not peeled off from the surface of the roll R. The process proceeds to step S17. In step S17, as described above, the user is urged to perform a manual operation for inserting the tip end portion of the sheet 1 into the sheet supply path. Therefore, the threshold value ΔH1 serves as a criterion for determining whether or not the tip end portion of the sheet 1 is peeled off from the surface of the roll R. L is the lowest level of sensor output.

When the amount of change in the level of the sensor output of the CPU 201 is larger than the threshold value ΔH1, FIG.
As in 9 (b) or (c), it is determined that the tip end portion of the sheet 1 has peeled off from the surface of the roll R. Then, on condition that the L level of the sensor output continues for a certain period of time, the roll R
(Steps S13 and S14). After that, the CPU 201 determines whether or not the amount of change in the level of the sensor output is larger than the predetermined threshold value ΔH2 (= H2-L) (step S62). When the level change amount is larger than the threshold value ΔH2, as shown in FIG. 19B, it is determined that the tip portion has normally peeled off from the surface of the roll R, and automatic loading is executed (as shown in FIG. 19B).
Step S15). On the other hand, when the amount of level change is not larger than the threshold value ΔH2, FIG. 19
As shown in (c), it is determined that the amount of peeling of the tip of the sheet 1 from the surface of the roll R is smaller than in the normal state. In this way, when the amount of peeling of the tip of the sheet 1 is smaller than that in the normal state, the sheet 1 can be automatically loaded depending on the rigidity of the sheet 1, so that the rigidity of the sheet 1 is a predetermined value. It is determined whether or not the above is the case (step S63). The rigidity of the sheet 1 is determined based on, for example, the information regarding the type of the sheet 1 input by the user. The determination criteria for determining the rigidity of the sheet 1 may be set according to the width size of the sheet 1, the usage state of the sheet 1, the usage environment of the printing apparatus, and the like, in addition to the information regarding the type of the sheet 1. If the rigidity of the sheet 1 is equal to or higher than the predetermined value, the process proceeds to step S15 to execute automatic loading, and if the rigidity of the sheet 1 is less than the predetermined value, the process proceeds to step S17.
The user is urged to perform a manual operation for inserting the tip of the sheet 1 into the sheet supply path.

In this way, the peeling amount of the tip portion of the sheet 1 is detected according to the sensor output of the sensor unit 6, and automatic loading is executed on the premise that the peeling amount and the rigidity of the sheet 1 satisfy a predetermined condition. As a result, it is possible to avoid the occurrence of jam on the sheet 1 in the printing apparatus.

(7th Embodiment)
22 and 23 are explanatory views of a seventh embodiment of the present invention. In the present embodiment, when the tip of the sheet 1 cannot be automatically fed into the sheet supply path, that is, when automatic loading cannot be executed, the tip of the sheet 1 is within a predetermined range for manual paper feeding. To be located in. FIG. 22 is an explanatory view of a stop position of the tip end portion of the sheet 1, and FIG. 23 is a flowchart for explaining the sheet tip tip setting process (automatic loading) in the present embodiment.

If the tip of the sheet 1 cannot be automatically fed into the sheet supply path, the sheet 1 is within the range θ1 (within the visible range) between the driven roller 10a and the driven rotating body 9 as shown in FIG. The roll R is rotated in the reverse direction in the direction of arrow C2 so that the tip of the roll R is positioned. The range θ1 is
The range of the peripheral surface of the roll R visible to the user when the roll R is attached to and detached from the printing device is included. By locating the tip of the sheet 1 within such a range θ1,
The user is made to visually recognize the tip portion of the sheet 1, and the workability of the manual operation of inserting the tip portion of the sheet 1 into the sheet supply path is improved.

In the sheet tip setting process of the present embodiment, as shown in FIG. 23, the tip portion of the sheet 1 is set within a predetermined range θ with respect to the sheet tip setting process of FIG. 21 in the sixth embodiment described above.
An operation (step S71) for stopping at a position within 1 has been added. The CPU 201 identifies the position of the tip of the sheet 1 based on the processing information in steps S61, S13, and S16, and then stops the rotation of the roll R (step S14), and then the level change amount and the threshold value of the sensor output. Compare with ΔH2 (step S62). When the level change amount is larger than the threshold value ΔH2, as described above, it is determined that the tip end portion of the sheet 1 has normally peeled off from the surface of the roll R, and automatic loading is executed (step S15). Level change amount is threshold ΔH
If it is not larger than 2, as described above, automatic loading is executed on condition that the rigidity of the sheet 1 is equal to or higher than a predetermined value (steps S63 and S15). If the rigidity of the sheet 1 is less than a predetermined value, the rigidity of the sheet 1 is low and jam may occur.
The roll R is rotated in the reverse direction in the direction of arrow C2 so that the tip end portion of the sheet 1 whose position is specified in the previous steps S61, S13, and S16 is positioned within the range θ1. After that, the process proceeds to step S17, prompting the user to perform a manual operation of inserting the tip of the sheet 1 into the sheet supply path.

In this way, by locating the tip of the sheet 1 within a predetermined range that the user can see, the visibility of the tip of the sheet 1 by the user can be improved. In addition, the user can smoothly insert the tip end portion of the sheet 1 into the sheet supply path by combining it with the alerting by the display on the panel or the like. This allows the user to easily perform manual paper feeding.

In this example, from the viewpoint of visibility of the tip portion of the sheet 1 by the user, as shown in FIG.
The stop position of the tip of the sheet 1 is within the range θ1 between the driven roller 10a and the driven rotating body 9. However, in order to reduce the amount of rotation of the roll R and shorten the time required for the manual insertion operation of the tip of the sheet 1, the driven roller 10a and the driven rotating body 9 are different from the range θ1.
The tip end portion of the sheet 1 may be stopped within the range between and.

(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. For example, FIG.
As in No. 4, the driven rotating bodies 8 and 9 and the sensor unit 6 of the fixed structure 40 provided under the roll R are arranged, and regardless of the winding diameter of the roll R, the weight of the roll R determines. The roll R may be in pressure contact with the driven rotating bodies 8 and 9. Further, the roll R may be pressed against the driven rotating bodies 8 and 9 by using a drive mechanism (not shown).

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. Also,
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 sheet 6 sensor unit (sensor)
6c Light emitting part 6d Light receiving part 4b Guide part (lower guide)
10 Separation flapper (upper guide)
100 Printing device 200 Sheet feeding device 400 Printing section R roll

Claims (12)

A driving means for rotating the roll in a first direction for feeding the sheet from the roll formed by winding the sheet, a second direction opposite to the first direction, and a roll rotating in the second direction. It is equipped with a detection means whose output changes according to the distance from the sheet.
A sheet supply device that rotates a roll rotating in the second direction in the first direction by the driving means after detecting a sheet tip portion of the roll by an output from the detecting means.
Detecting the sheet tip of the roll based on a change across the threshold and a non-change section across the threshold in the output from the detection means when the roll is rotating in the second direction. A featured sheet supply device. The sheet supply device according to claim 1, wherein the section is a range from the time when the output of the detection means crosses the threshold value to the time when the output of the detection means crosses the threshold value next time. The section according to claim 1 or 2, wherein the section is in the range from the change where the output of the detection means exceeds the threshold value to the time when the output does not exceed the threshold value and then exceeds the threshold value. Sheet feeder. If there are multiple sections, select the largest section from them and select the largest section.
The sheet supply device according to any one of claims 1 to 3, wherein the sheet tip portion of the roll is detected based on a change across the threshold value immediately before the selected maximum section. The sheet supply device according to any one of claims 1 to 4, further comprising a contact member that contacts the roll rotating in the second direction at a contact position. When the rotation angle at which the sheet tip portion of the roll rotating in the second direction passes through the detection position of the detection means and rotates to the contact position is θ.
The sheet supply device according to claim 5, wherein when the output of the detection means exceeds the range based on θ from the point where the threshold value is crossed, the section is set. The sheet supply device according to any one of claims 1 to 6, further comprising a rotation amount sensor for acquiring a rotation angle of a roll. The sheet supply device according to claim 7, wherein the roll is stopped at a rotation angle for feeding the sheet after detecting the sheet tip portion of the roll. The sheet supply device according to any one of claims 1 to 8, wherein the roll is rotated in the second direction by the driving means after detecting the sheet tip portion of the roll. The sheet supply device according to any one of claims 1 to 9, wherein the threshold value is calculated from the output of the detection means when the roll is rotating in the second direction. After detecting the tip of the sheet, the roll is rotated in the first direction by the driving means to feed the sheet.
Claims 1 to 10 are characterized in that, when the sheet tip portion cannot be fed out, the roll rotation is stopped after the roll is rotated by the driving means until the sheet tip portion is within a range visible to the user. The sheet supply device according to any one of the above items. A printing apparatus comprising a printing means for printing an image on a sheet supplied from the sheet supplying apparatus according to any one of claims 1 to 11.

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