JP2020117326A - Printing equipment - Google Patents

Abstract

To provide printing equipment detecting abnormally quickly when winding a sheet on which an image was printed.SOLUTION: Printing equipment according to the present invention comprising a printing part printing an image on a sheet, a spool member winding the sheet discharged from the printing part in a role shape, a holding part holding the spool member rotatably, a drive mechanism rotary driving the spool member that the holding part holds, and a sensor outputting an output value based on a distance to an outer periphery of the wound sheet comprises a control part acquiring an output value while rotating the spool member when winding the sheet, the control part stops rotation of the spool member when a difference between an output value in a first period acquired at a prescribed angle of the spool member and an output value in a second period smaller than the first period exceeds a threshold.SELECTED DRAWING: Figure 11

Description

The present invention relates to a printing apparatus including a winding device that winds a sheet on which an image is printed in a roll shape.

Patent Document 1 discloses a printing apparatus including a winding device that winds a sheet on which an image is printed in a roll shape. In this printing apparatus, a weight member is arranged on the sheet between the discharge portion of the sheet on which the image is printed and the spool member that winds the sheet to loosen the sheet. The sheet winding operation is performed for a predetermined time when the slack of the sheet blocks the light between the LED that emits light and the light receiving sensor that receives the light on the stand of the printing apparatus. Since the speed of the sheet discharged from the discharge unit is constant, when the winding operation is not periodic, it can be determined that the winding operation is abnormal.

JP, 2007-331934, A

However, in Patent Document 1, since the light receiving sensor detects the sheet before being wound, it is difficult to accurately detect the case where the sheet is inclined and wound while gradually forming wrinkles. If the abnormal winding condition is detected after the wrinkle is deteriorated and the sheet is clogged, the ink and the sheet are lost. SUMMARY OF THE INVENTION It is an object of the present invention to provide a printing apparatus that promptly detects an abnormality when winding a sheet on which an image is printed.

The printing apparatus of the present invention includes a printing unit that prints an image on a sheet, a spool member that winds a sheet discharged from the printing unit into a roll shape, a holding unit that rotatably holds the spool member, and a holding unit that holds the spool member. A printing device comprising: a drive mechanism for rotationally driving a wound spool member; and a sensor for outputting an output value based on a distance to the outer circumference of a wound sheet, wherein the spool member is rotated when the sheet is wound. And a control unit that acquires the output value while the output value of the spool member is at a predetermined angle, and the difference between the output value of the first cycle and the output value of the second cycle that is smaller than the first cycle is a threshold value. It is characterized in that the rotation of the spool member is stopped when it exceeds.

According to the present invention, an abnormality at the time of winding a sheet can be promptly detected by a difference between output values from sensors having different cycles.

FIG. 3 is a perspective view showing the appearance of the printing apparatus. FIG. 3 is a schematic diagram of a main part of the printing apparatus. FIG. 3 is a block diagram of a control system of the printing apparatus. It is explanatory drawing of a spool member at the time of supplying a sheet. It is a figure which shows a sheet|seat supply apparatus. It is explanatory drawing of the winding spool member at the time of winding a sheet. It is a figure which shows the outer diameter of a roll sheet, and the relationship of a pressure contact mechanism. It is a figure which shows the wound sheet|seat of a normal state and an abnormal state. It is a figure which shows the relationship between the outer diameter of a roll sheet, the distance of a sensor, or a sensor output value. It is a figure which shows the relationship of a sensor output value with respect to a rotation angle. It is a flowchart of a printing operation and a winding operation.

Embodiments of the present invention will be described below with reference to the drawings.

(Inkjet printing device)
The configuration of the printing apparatus according to the embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view showing the outer appearance of the printing apparatus, and FIG. 2 is a schematic view of the main part of the printing apparatus. FIG. 3 is a block diagram of a control system of the printing apparatus.

The printing apparatus 100 of the present invention includes a sheet supply device (200, 210) for supplying a sheet that is a print medium. This sheet feeding device can also be used for winding a sheet on which an image is printed. Further, it is provided with a conveyance unit 300 that conveys the supplied sheet, and a printing unit 400 that ejects ink onto the conveyed sheet to print an image.

In the printing apparatus 100, sheet feeding devices (200, 210) are arranged on the upper and lower stages. Here, a case will be described in which a sheet is supplied to the print unit 400 by the upper sheet supply device 200 and the sheet discharged from the print unit 400 is wound by the lower sheet supply device 210. The sheet 1 supplied from the roll sheet R installed in the sheet supply device 200 is conveyed to the printing unit 400 that prints an image by the conveyance unit 300 along the conveyance path. The sheet 1 discharged from the printing unit 400 can be wound into a roll by the lower sheet feeding device 210. The user can give instructions such as initial setting, various operations, and switching between online/offline using various switches provided on the operation panel 28. In the coordinate system, the width direction of the roll sheet is the X direction, the direction in which the sheet 1 is conveyed in the printing unit 400 is the Y direction, and the gravity direction is the Z direction.

The sheet feeding device (200, 210) includes a spool member 2, a holding portion (not shown), an arm member 4, a sensor unit 6, a swing member 7, an arm driving portion 3, a pressure contact rotating body (8, 9), and a separation flapper. 10 is provided. The roll sheet R is rotatably supported by the spool member 2 inserted in the hollow hole and a holding portion that holds the spool member 2. The arm member 4, the swinging member 7, the pressure contact rotating body (8, 9), and the arm drive unit 3 are the pressure contact mechanism of the present invention. The pressure contact mechanism 13 presses the pressure contact rotating body (8, 9) of the swing member 7 against the roll sheet R when feeding the sheet 1, and guides the sheet 1. The pressing force by the press contact mechanism 13 can be adjusted by the pressing force adjusting motor 34. This pressing state includes a pressing state with a relatively large force (strong nip state), a pressing state with a relatively small force (weak nip state), and a released state in which the pressing force is released. The separation flapper 10 separates the sheet 1 from the roll sheet R when the sheet 1 is supplied, and guides the separated sheet 1. The arm member 4 and the separation flapper 10 form a supply path for the sheet 1.

The roll drive motor 33 is a drive mechanism that rotationally drives the spool member 2 in the forward direction (C1 direction) and the reverse direction (C2 direction). Further, the rotation amount sensor 36 can detect the angle and the rotation amount of the spool member 2, that is, the roll sheet R. The rotation amount sensor 36 is a rotary encoder that outputs a number of pulses corresponding to the rotation amount of the roll sheet R. When the roll drive motor 33 rotates the spool member 2 in the forward direction, the roll sheet R rotates accordingly. The sheet 1 supplied from the roll sheet R is supplied to the transport unit 300 through the supply path. The cover 42 prevents the sheet 1 on which the image is printed from entering the sheet feeding apparatus 200. The sensor unit 6 detects that the leading end of the sheet 1 is separated from the roll sheet R when the sheet 1 is supplied.

The transport unit 300 includes a transport guide 12, an edge detection sensor 16, a transport roller 14, and a pinch roller 15. The transport guide 12 provided in the transport unit 300 guides the front surface and the back surface of the supplied sheet 1. The edge detection sensor 16 is a sensor that optically detects the leading edge or the trailing edge of the sheet 1 on the upstream side of the transport roller 14. The edge of the sheet 1 can be detected by detecting the reflected light from the sheet 1. The carry roller 14 can be rotated in the forward direction (D1 direction) and the reverse direction (D2 direction) by the carry roller drive motor 35. The pinch roller 15 can be driven to rotate according to the rotation of the transport roller 14. The sheet 1 is conveyed to the printing unit 400 by sandwiching the sheet 1 between the conveyance roller 14 and the pinch roller 15. The transport speed of the transport roller 14 is set to be higher than the speed at which the sheet 1 is supplied by the rotation of the roll sheet R. As a result, back tension is applied to the sheet 1 and the slack of the sheet 1 can be prevented.

The print unit 400 includes a print head 18, a platen 17, a suction fan 19, and a scanning mechanism (not shown). The negative pressure generated by the suction fan 19 causes the back surface of the sheet 1 to be adsorbed to the platen 17 through the suction holes 17a. As a result, the posture of the seat 1 can be regulated along the platen 17. An image is printed on the sheet 1 supported by the platen 17 by ejecting ink from the inkjet print head 18. Ink ejection is performed using an electrothermal conversion element (heater). The printing method is a serial scan method. That is, the conveyance operation of the sheet 1 (Y direction) and the scanning of the print head 18 in the direction intersecting with it (X direction) are alternately performed, and images are sequentially printed on the sheet 1. After printing is completed, the sheet 1 discharged from the printing unit 400 is wound by rotating the spool member 2 of the sheet supply device 210 in the direction opposite to the direction in which the sheet is supplied. At this time, the pressure contact mechanism 13 is in the released state in which the pressing force is released. Further, the separation flapper 10 contacts the surface of the roll sheet R.

The control unit 201 controls each unit of the printing apparatus 100 including the sheet feeding device (200, 210), the conveyance unit 300, and the printing unit 400 according to a control program stored in the ROM 204. Further, the control unit 201 can make various determinations based on the detection results from the sensor unit 6, the edge detection sensor 16, and the rotation amount sensor 36. Further, the control unit 201 controls the transport roller drive motor 35, the roll drive motor 33, the pressing force adjustment motor 34, and the nip force adjustment motor 37 based on various instructions and the determination result. The type, width, and various setting information of the seat 1 are input to the control unit 201 from the operation panel 28 via the input/output interface 202. Further, it is connected to various external devices 29 including a host device such as a personal computer via the external interface 205, and the control unit 201 exchanges various information such as print data with the external device 29. Further, the control unit 201 writes and reads various information to and from the RAM 203.

The printing apparatus is not limited to the configuration including two sheet feeding devices corresponding to each of the two roll sheets, and may have a configuration including three or more sheet feeding devices. Further, the printing device may be configured to print an image on the sheet supplied from the sheet supply device, and is not limited to the inkjet printing device. Further, the printing method may be a full line method in which a sheet is continuously conveyed to a position facing a long print head to print an image.

(Sheet feeding device)
The sheet feeding device will be described. FIG. 4 is an explanatory diagram of the spool member when the sheet is supplied. The spool member 2 includes a spool shaft 21, a friction member 22, a reference side spool flange 23, a non-reference side spool flange 24, and a spool gear 25. A reference side spool flange 23 is provided at one end of the spool shaft 21, and a spool gear 25 for rotating the spool shaft 21 is attached at the other end. The friction member 22 is provided inside the reference side spool flange 23 and the non-reference side spool flange 24. The sheet 1 is wound around a tubular member (not shown) to form a roll sheet R.

When mounting the spool member 2 on the roll sheet R, the non-reference side spool flange 24 of the spool shaft 21 is removed, and the spool shaft 21 is inserted into the tubular member of the roll sheet R. Since the outer diameter of the spool shaft 21 is slightly smaller than the inner diameter of the tubular member of the roll sheet R, the user can insert the spool shaft 21 with a slight force. The side end of the roll sheet R contacts the reference spool flange 23, and the friction member 22 inside the reference spool flange 23 is fitted into the tubular member. In this way, the reference spool flange 23 is fixed to the roll sheet R. After that, the non-reference side spool flange 24 is passed through the spool shaft 21, and the friction member 22 in the non-reference side spool flange 24 is fitted and fixed to the tubular member of the roll sheet R (FIG. 4B). By fitting both ends of the spool member 2 into the holding portions of the sheet feeding device 200, the mounting of the roll sheet R is completed.

FIG. 5 is a diagram showing a sheet feeding device. The transport guide 12 is provided with an arm member 4 rotatable about the arm rotation shaft 5 in the A1 and A2 directions. The arm member 4 is provided with a guide portion 4b that guides the lower surface of the sheet 1 supplied from the roll sheet R. The rotation of the arm member 4 is performed by using the rotation cam 3a of the arm drive unit 3. A torsion coil spring 3c for pressing the arm member 4 in the direction of arrow A1 is provided between the arm member 4 and the rotary cam 3a. The rotary cam 3a is rotated by the pressing force adjusting motor 34, and the pressing force on the arm member 4 is changed according to the rotational position.

Further, a swing member 7 is swingably provided on the arm member 4, and a first pressure contact rotating body 8 and a second pressure contact rotating body 9 rotate on the swing member 7 in the outer peripheral direction of the roll sheet R. It is possible. These pressure contact rotating bodies (8, 9) move according to the outer diameter of the roll sheet R by the pressing force in the A1 direction, and press the surface of the roll sheet R from below in the direction of gravity. By rotating the rotating cam 3a according to the change in the outer diameter of the roll sheet R, the pressing force of the pressure contact mechanism 13 against the roll sheet R can be maintained within a predetermined range. When the sheet is supplied, the pressure contact rotating body (8, 9) is pressed against the surface of the roll sheet R, so that the slack of the sheet 1 is suppressed.

The separation flapper 10 is rotatable above the arm member 4 around the flapper rotation shaft 11 in the directions of the arrows (B1, B2), and can lightly contact the surface of the roll sheet R by its own weight. Therefore, the separation flapper 10 comes into contact with the surface of the roll sheet R according to the change in the outer diameter of the roll sheet R and is displaced. A roller 10a is rotatably provided at the contact portion of the separation flapper 10 with the roll sheet R in order to suppress the influence of friction on the sheet 1. The separation portion 10b at the tip of the separation flapper 10 is formed at a position as close as possible to the surface of the roll sheet R in order to easily separate the tip of the sheet 1 from the roll sheet R.

The sheet 1 is fed from the roll sheet R through the pressure contact rotating body (8, 9), and the lower surface thereof is guided by the guide portion 4b on the upper portion of the arm member 4. Then, the sheet 1 is supplied to the transport unit 300 through a supply path formed between the separation flapper 10 and the arm member 4. Further, since the arm member 4 and the separation flapper 10 move according to the change in the outer diameter of the roll sheet R, a supply path having a substantially constant height is formed. As a result, even if the outer diameter of the roll sheet R changes, the sheet 1 can be reliably supplied from the roll sheet R.

The sensor unit 6 is an optical sensor including an irradiation unit such as an LED and a light receiving unit such as a photodiode. The light emitted from the irradiation unit toward the roll sheet R is reflected by the surface of the roll sheet R and detected by the light receiving unit. The output value of the sensor unit 6 can be acquired by the control unit 201 at an arbitrary timing. Although an optical sensor is used here, another sensor may be used as long as its output value changes depending on the distance to the outer circumference of the roll sheet. For example, an ultrasonic sensor or a capacitance sensor that detects the distance to the object without contact can be used.

(Sheet winding)
The sheet winding operation by the sheet feeding device will be described.

FIG. 6 is an explanatory diagram of a take-up spool member when taking up a sheet on which an image is printed. The take-up spool member R2 is attached to the holding portion. The user fixes the leading end portion of the sheet 1 discharged from the printing unit 400 with the tape 1a between the reference side spool flange 23 and the non-reference side spool flange 24 of the take-up spool member R2. When the fixing is completed, the winding operation for winding the sheet 1 can be started. The wound sheet 1 is held by the holding unit as it is as a roll sheet for printing an image on the back surface.

FIG. 7 shows the relationship between the outer diameter of the roll sheet and the pressure contact mechanism. The sheet 1 is wound by rotating the winding spool member R2 in the C2 direction. At that time, the press contact mechanism 13 presses the press contact rotor (8, 9) onto the outer periphery of the wound sheet 1. As the winding of the sheet 1 progresses, the outer diameter of the roll sheet gradually increases as shown in FIGS. 7(a) to 7(b). The pressure contact mechanism 13 moves according to the outer diameter of the roll sheet. The distance between the sensor unit 6 of the arm member 4 and the roll sheet decreases as the outer diameter of the roll sheet increases. Since the sensor directly faces the outer circumference of the roll sheet, the output value of the sensor unit 6 increases as the outer diameter of the roll sheet increases.

FIG. 8 shows a wound sheet in a normal state and an abnormal state. When the sheet 1 is wound in a normal state, the sheet 1 is wound without coming off the spool flange. Therefore, the outer diameter of the roll sheet increases as the winding progresses. On the other hand, the sheet 1 wound in an abnormal state may be bent and bulged, or the sheet may get over the spool flange and eventually become jammed. That is, when the seat 1 is obliquely fixed, the side end portion of the seat 1 gradually contacts the spool flange on one side and becomes wrinkled. Then, the wrinkle state further deteriorates, and the abnormal state as described above occurs.

FIG. 9 shows the relationship between the distance of the sensor unit and the output value of the sensor unit with respect to the outer diameter of the roll sheet. The first axis on the left side is the distance from the sensor unit, and the second axis on the right side is the output value of the sensor unit. The distance between the sensor unit 6 and the outer circumference of the roll sheet R decreases as the outer diameter of the roll sheet R increases. On the other hand, the output value of the sensor unit 6 increases as the outer diameter of the roll sheet R increases. When an abnormality occurs in the winding, the outer diameter of the roll sheet R suddenly increases, so that the distance between the sensor unit 6 and the wound sheet 1 becomes shorter than in the normal case. As a result, when an abnormality occurs, the output value of the sensor unit 6 increases.

FIG. 10 shows the relationship between the rotation angle of the take-up spool member and the output value of the sensor unit. The horizontal axis represents the rotation angle of the spool member 2, and the vertical axis represents the output value of the sensor unit 6. The rotation angle is 360 degrees and returns to 0 degrees. That is, 360 degrees (point 1) in one cycle and 0 degrees (point 1') in two cycles have the same value. Similarly, 360 degrees (point 2) of 2 cycles and 0 degrees (point 2') of 3 cycles,..., 360 degrees (point N) of N cycles and 0 degrees (point N') of N+1 cycles are the same. is there. It is a normal state from the 1st cycle to the Nth cycle and an abnormality occurs in the (N+1)th cycle. When the take-up spool member R2 makes one rotation, the output value of the sensor fluctuates without increasing uniformly. This is because there is play during installation of the take-up spool member, distortion of the take-up spool member 2 itself, and eccentricity due to the tape tension. When the winding is normal, the output value at the predetermined angle increases up to N cycles while satisfying the relationship of the output values in FIG. When an abnormality occurs in the N+1 cycle, the amount of change will increase rapidly. As a result, when the difference between the output value in the N+1 cycle and the output value in the N cycle is calculated, it changes depending on the angle as indicated by the broken line. Therefore, it is possible to detect the winding abnormality when there is a change in the predetermined angle that exceeds the threshold value. The threshold value may differ depending on the outer diameter of the roll sheet. Further, the predetermined angle may be plural, for example, every 45 degrees. Further, when calculating the difference between the output values, the difference of M cycles may be used as an integer M of 2 or more instead of the difference of one cycle.

By the way, although the outer circumference of the wound sheet is pressure-contacted by the pressure contact mechanism at the time of winding, the pressure contact mechanism may be separated from the outer circumference of the wound sheet. In the released state, when the outer diameter of the roll sheet increases, the distance between the outer circumference of the roll sheet and the sensor unit decreases. If the winding of the sheet is abnormal, the distance between the sensor unit and the outer circumference of the roll sheet changes greatly. When the difference between the output values exceeds the threshold value, it is possible to detect an abnormality at the time of winding the sheet.

As described above, the abnormality at the time of winding the sheet can be detected.

(Flowchart for printing)
The printing operation and the winding operation will be described with reference to the flowchart of FIG. In the print operation, the sheet is supplied from the sheet supply device 200 to the print unit 400, and an image is printed on the sheet. In the winding operation, the sheet discharged from the printing unit 400 is wound by the sheet feeding device 210. At the time of winding, it is possible to detect an abnormal state of the wound sheet.

In step S101, a sheet supply and winding sequence is started. Here, the roll sheet R is installed in the sheet supply device 200, and the take-up spool member R2 is installed in the sheet supply device 210. The user gives a start instruction from the operation panel 28.

In step S102, it is confirmed whether the spool members are installed in the sheet feeding devices on the feeding side and the winding side. The control unit 201 detects the spool member by the roll sensor 32 and confirms that the spool member is installed in the sheet feeding device (200, 210). The pressure contact mechanism 13 of the sheet supply device 200 is in a weak nip state, and the pressure contact mechanism 13 of the sheet supply device 210 is in a released state. Repeat this process until the spool member is visible.

In step S103, the sheet supply device 200 ejects a predetermined amount of the sheet 1. The user fixes the leading end of the sheet 1 discharged onto the take-up spool member R2 of the sheet supply device 210 to take up the sheet 1.

In step S104, the user inputs to the operation panel 28 that confirmation that the winding can be started has been completed. As a result, the pressure contact mechanism 13 of the sheet feeding device 210 on the winding side is changed to the weak nip state.

In step S105, the spool member 2 is rotated once to acquire the output value of the sensor unit 6 at a predetermined angle. The predetermined angle is a plurality of angles from 0 degree to 45 degrees. The control unit 201 stores the acquired output value in the RAM as an initial value. An error may be displayed when the initial value of the predetermined angle is outside the range of the allowable value with respect to the reference value. This reference value is a value stored in advance at the time of factory shipment. However, the reference value may be changed appropriately according to the usage environment.

In step S106, the user issues a print instruction from the operation panel 28.

In step S107, an image is printed on the sheet 1 and the sheet 1 is wound up. Here, the printing of the image and the winding of the sheet 1 are alternately performed for each image. To print an image on the sheet 1, the operation of scanning the print head line by line and the operation of discharging the sheet 1 may be alternately repeated. At this time, the winding of the sheet 1 is performed according to the discharge speed of the printing operation. The discharge speed is, for example, several centimeters to several tens of centimeters/second.

In step S108, the control unit 201 acquires the output value at the predetermined angle from the sensor unit 6 in accordance with the winding operation, and sequentially stores the output value in the RAM 203.

In step S109, the control unit 201 calculates the difference between the current output value and the output value of the previous cycle.

In step S110, if the difference between the output values is less than or equal to the threshold value, the process proceeds to step S111. If the difference between the output values exceeds the threshold value, the process proceeds to step S112 to stop the winding of the sheet and display an error to that effect.

In step S111, it is determined whether printing of all images has been completed. If it is completed, the process proceeds to step S113, and if it is not completed, the process returns to step S107.

In step S113, the printing operation and the winding operation are completed. At this time, the sheet 1 is cut by the cutter 20 as necessary, and after winding a predetermined amount, the winding operation is stopped.

As described above, the sensor unit that detects the leading edge of the sheet when the sheet is supplied is used during the winding operation. As a result, it is possible to quickly detect an abnormality in winding the sheet.

2 spool member 6 sensor unit 15 pressure contact mechanism 33 roll drive motor 201 control unit 400 printing unit

Claims (9)

The print part that prints the image on the sheet,
A spool member that winds the sheet discharged from the printing unit into a roll,
A holder for rotatably holding the spool member,
A drive mechanism for rotationally driving the spool member held by the holding portion;
A printing device comprising: a sensor that outputs an output value based on the distance to the outer circumference of the wound sheet;
When winding the sheet, a control unit that acquires the output value while rotating the spool member is provided.
The control unit controls the spool member when a difference between the output value of the first period acquired at a predetermined angle of the spool member and the output value of a second period smaller than the first period exceeds a threshold value. A printing device characterized by stopping the rotation of the printer. When a sheet is supplied from the roll sheet to the printing unit, a press contact mechanism for pressing the outer periphery of the roll sheet is provided,
The holding unit can hold a roll sheet for feeding a sheet,
The printing apparatus according to claim 1, wherein the sensor is arranged in the press contact mechanism. The printing apparatus according to claim 2, wherein when the sheet is wound, the pressure contact mechanism presses the outer circumference of the wound sheet. The printing apparatus according to claim 2, wherein when the sheet is wound, the pressure contact mechanism is separated from the outer circumference of the wound sheet. The said sensor is an optical sensor which has an irradiation part which irradiates a sheet|seat with light, and the light-receiving part which receives the reflected light reflected from the sheet|seat, The optical sensor of any one of Claim 1 thru|or 4 characterized by the above-mentioned. Printing equipment. 6. The printing apparatus according to claim 1, wherein when the sheet is wound, an output value of the predetermined angle in the first cycle is acquired and stored as an initial value. 7. The printing apparatus according to claim 1, wherein the control unit acquires the difference between the output values at a plurality of the predetermined angles. 8. The printing apparatus according to claim 1, wherein a difference between the first cycle and the second cycle is 1. 9. The printing apparatus according to claim 1, wherein the threshold differs depending on the outer diameter of the wound sheet.

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