Media delivery device, image forming device

Abstract

The objective of this invention is to miniaturize a media supply device or a device equipped with a media supply device. [Solution] A paper feeder 20 equipped with a support plate 30, which rotates a roll of paper Pr in which a sheet of paper P is wound into a roll, thereby unwinding the paper P from the roll of paper Pr and transporting it downstream in the paper transport direction, wherein the support plate 30 includes a tip detection sensor 36 that contacts the roll of paper Pr to detect the leading edge of the roll of paper Pr, a first support part 31 that supports the tip detection sensor 36, a first rotation fulcrum 32 which is the pivot point for the rotational movement of the first support part 31, a separation roller 37, and a separation roller 3 The separation roller 37 is characterized by comprising a second support portion 33 that supports the 7 and a second pivot point 34 which is the pivot point for the rotational movement of the second support portion 33 relative to the first support portion 31, and by rotating the first support portion 31 around the first pivot point 32, the tip detection sensor 36 comes into contact with the roll paper Pr, and by rotating the second support portion 33 around the second pivot point 34, the separation roller 37 comes into contact with the roll paper Pr.

Description

Technical Field

[0001] The present invention relates to a medium feeding device and an image forming device.

Background Art

[0002] As a medium feeding device for feeding out a roll paper (roll-shaped body) and conveying it downstream, there is a paper feeding device provided in an image forming device or the like. And there is a paper feeding device that detects the leading end of the roll paper on the device side and automatically feeds the paper.

[0003] For example, in the paper feeding device of Patent Document 1 (Japanese Patent Application Laid-Open No. 2024-80480), a support member that supports a detection sensor for detecting the leading end of the roll paper is provided. Also, a separation roller member is provided that abuts on the leading end of the roll paper on the downstream side in the rotation direction of the roll paper from the support member and bends the leading end side of the roll paper to separate it from the roll paper body. The separation roller member is held by an inlet guide plate.

Summary of the Invention

Problems to be Solved by the Invention

[0004] When providing a member for holding a separation roller member separately from the support member as in the configuration of Patent Document 1, there is a problem that the space for its arrangement becomes large, or the paper conveyance path becomes long due to restrictions in the paper feeding direction and the entire device becomes large-sized.

[0005] An object of the present invention is to miniaturize a medium feeding device or a device provided with the medium feeding device.

Means for Solving the Problems

[0006] To solve the above problems, the present invention provides a medium feeding device for dispensing the medium from the roll-shaped body and transporting it downstream in the medium transport direction, wherein the support member comprises a detection member that contacts the roll-shaped body and detects the tip of the roll-shaped body, a first support portion that supports the detection member, a first pivot point which is the pivot point for the rotational movement of the first support portion, a separation member, a second support portion that supports the separation member, and a second pivot point which is the pivot point for the rotational movement of the second support portion relative to the first support portion, wherein the separation member contacts the tip of the roll-shaped body and separates the tip from the roll-shaped body, the detection member contacts the roll-shaped body by rotation around the first pivot point of the first support portion, and the separation member contacts the roll-shaped body by rotation around the second pivot point of the second support portion. [Effects of the Invention]

[0007] The media feeding device or the device equipped with the media feeding device can be miniaturized. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic side cross-sectional view of an image forming apparatus according to one embodiment of the present invention. [Figure 2] This is a side view illustrating the main components of an example of the configuration of a paper feed device according to one embodiment of the present invention. [Figure 3] This is a perspective view showing the support plate. [Figure 4] This diagram shows how the support and separation parts of the support plate rotate according to the roll paper diameter and come into contact with the roll paper. [Figure 5] This diagram shows the configuration of the tip detection sensor; (A) is a perspective view, and (B) is a side view. [Figure 6] This is a side view showing the separation roller. [Figure 7] This diagram illustrates the sequence of events in which the leading edge of a sheet of paper is separated from the roll paper by a separation roller, and shows the process during the detection of the leading edge of the paper. [Figure 8]This diagram illustrates the process of separating the leading edge of a sheet of paper from a roll of paper using a separation roller, specifically showing the leading edge of the paper in contact with the separation roller. [Figure 9] This diagram illustrates the process of separating the leading edge of a sheet of paper from a roll of paper using a separation roller, showing the state where the leading edge of the paper is in contact with the separation roller and bent. [Figure 10] This diagram illustrates the process of separating the leading edge of the paper from the roll paper using a separation roller, and shows the paper in a state where it has become significantly flexed. [Figure 11] This diagram illustrates the process of separating the leading edge of the paper from the roll using a separation roller, specifically showing the process in reverse. [Figure 12] This diagram shows the sequence of events in which the leading edge of a sheet of paper is separated from the roll of paper by a separation roller, and how the leading edge of the paper is separated and transported downstream. [Figure 13] This diagram shows the separation unit retracting from the roll of paper. [Figure 14] This is an exploded perspective view of the various parts of the separation mechanism. [Figure 15] This is a perspective view of the assembled separation mechanism. [Figure 16] This is a functional block diagram illustrating an example of the paper feeder's functions. [Figure 17] This diagram illustrates an example of how the leading edge of a sheet of paper is detected. [Figure 18] (A) is a diagram showing the leading edge position of the paper, and (B) is a diagram showing the change in the sensor's output signal. [Figure 19] This is an explanatory diagram showing the details of the sensor output signal changes. [Figure 20] This is a flowchart showing the process leading up to the start of the paper transport operation. [Figure 21] Figure 20 is a flowchart showing the detailed flow of the paper leading edge detection process. [Figure 22] This flowchart shows the process that follows Figure 21. [Figure 23]It is a hardware block diagram of a control unit. [Figure 24] It is a perspective view showing a plurality of support plates provided in the width direction of a sheet of paper.

Embodiments for Carrying Out the Invention

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each figure, the same or corresponding parts are denoted by the same reference numerals, and the redundant description thereof will be simplified or omitted as appropriate.

[0010] Referring to FIG. 1, a configuration example of an image forming apparatus to which a sheet feeding apparatus according to an embodiment of the present invention is applied will be described. An image forming apparatus which is an aspect of an embodiment of the present invention is an inkjet printer that performs printing on a recording medium (medium) by discharging ink droplets corresponding to image data, but the present invention can also be applied to a copying machine or a printing machine such as an electrophotographic method that conveys a medium and performs printing.

[0011] In FIG. 1, an image forming apparatus 80 includes an image forming unit 60, a sheet feeding apparatus 20 as a medium feeding device, a paper discharge unit 90, an operation panel 170, and the like. The image forming unit 60 may be either a serial type or a line head type, but the serial type is adopted in the present embodiment.

[0012] The roll paper Pr is supported by a support plate (described later) provided on a roll paper receiving base. The sheet feeding apparatus 20 conveys the roll paper Pr downstream by rotating the roll paper Pr around a roll shaft 21 to feed out the sheet P (see the arrow A direction in FIG. 1). A pair of conveyance rollers 6 for conveying the sheet P is provided on the downstream side in the sheet conveyance direction of the roll paper Pr. The configuration of the sheet feeding apparatus 20 will be described later.

[0013] An image forming unit 60 is provided on the downstream side in the sheet conveyance direction of the sheet feeding apparatus 20. The sheet P is sent to the image forming unit 60 by a registration roller 10 provided on the downstream side in the sheet conveyance direction of the pair of conveyance rollers 6.

[0014] The image forming unit 60 includes a carriage 66 and a platen 74, etc. The carriage 66 holds a liquid ejection head. In the image forming unit 60, an image is formed when the liquid ejection head ejects droplets of each color onto the paper P corresponding to the image data. The carriage 66 is provided to be movable in the main scanning direction (the direction perpendicular to the paper plane in Figure 1).

[0015] The paper P is not limited to paper, but can be made of various types such as film. The image forming apparatus 80 rotatably holds the roll paper Pr. The roll paper Pr is the roll-shaped body of this embodiment, and the paper P unwound from the roll paper Pr is the sheet-shaped medium of this embodiment.

[0016] A chamber 75 equipped with a fan is provided at the bottom of the platen 74. By driving the fan in the chamber 75, the paper P on the platen 74 is transported while maintaining close contact with the platen 74.

[0017] The image forming apparatus 80 intermittently transports the paper P in the sub-scanning direction, and while the transport of the paper P in the sub-scanning direction is stopped, it moves the carriage 66 in the main scanning direction and ejects ink (liquid) from the nozzle row of the liquid ejection head mounted on the carriage 66 onto the paper P on the platen 74 to form (record) an image on the paper P.

[0018] Furthermore, a reflective sensor mounted on the carriage 66 detects both ends of the paper P transported to the image forming unit 60, and at the same time, the size of the paper P is detected from the main scanning direction position read by the sensor on the paper P.

[0019] A paper discharge unit 90 is provided downstream of the image forming unit 60 in the paper transport direction. The paper discharge unit 90 is equipped with a cutter 76 and a paper discharge roller 77. The cutter 76 cuts the paper P fed from the roll paper Pr to a predetermined length. The cutter 76 is provided along the sub-scanning direction (paper width direction) of the paper P.

[0020] To align the leading edge of the continuous paper P being transported, the cutter 76 is fixed to a wire or timing belt stretched between multiple pulleys (one of which is connected to a drive motor), and moves in the main scanning direction by the drive motor to cut the paper P to a predetermined length.

[0021] The paper P cut by the cutter 76 is transported by the paper discharge roller 77 and discharged outside the image forming apparatus 80. Although Figure 1 illustrates the case where paper P is fed from a single roll of paper Pr, a configuration in which paper is selectively fed from multiple (for example, two) rolls of paper is also possible. Alternatively, the image forming apparatus may be configured to invert the paper and form an image on both sides.

[0022] The control unit 110 controls the roll drive unit 130 for rotating the roll paper Pr and the transport drive unit 150 for driving the transport roller pair 6. The roll drive unit 130 includes a motor that transmits driving force to the roll shaft 21. The transport drive unit 150 includes a motor that transmits driving force to the transport roller pair 6. The transport drive unit 150 may also transmit driving force to the registration roller 10, the paper discharge roller 77, and other transport means for transporting paper within the image forming apparatus.

[0023] The paper feed device 20 of this embodiment detects the leading edge of the roll paper Pr by detecting a step on the leading edge of the roll paper Pr using a sensor, and then performs a transport operation to separate the leading edge of the roll paper Pr from the roll paper Pr and transport it.

[0024] In the image forming apparatus 80 described above, the paper P unwound from the roll paper Pr is transported without being folded, and in this embodiment in particular, it is transported in a straight line in almost one direction, so the transport distance of the paper P can be shortened and the image forming apparatus 80 can be made smaller.

[0025] Figure 2 is a side view illustrating the main components of the paper feed device 20 of this embodiment. Figure 3 is a perspective view showing the support plate 30.

[0026] As shown in Figure 2, the paper feeder 20 rotatably holds the roll paper Pr by the roll shaft 21. The roll shaft 21 is rotatable in both directions, and this rotation causes the roll paper Pr to perform forward rotation in the direction of arrow B1 and reverse rotation in the direction of arrow B2 as shown in Figure 2. The forward rotation of the roll paper Pr causes it to be fed downstream as paper P from its leading edge Pa and transported to the nip portion of the transport roller pair 6 (see paper transport direction A in Figure 2). The roll shaft 21 is the holding part of this embodiment that rotatably holds the rolled body.

[0027] The paper feeder 20 includes a support plate 30 as a support member. As shown in Figures 2 and 3, the support plate 30 has a detection unit 30A and a separation unit 30B. The detection unit 30A includes a first support unit 31, a contact roller 35, and a tip detection sensor 36 as a detection member. The separation unit 30B includes a second support unit 33 and a separation roller 37. The first support unit 31 rotatably supports the contact roller 35 and supports the tip detection sensor 36. The second support unit 33 rotatably supports the separation roller 37. The support plate 30 extends along the outer circumferential surface of the roll paper Pr. This allows the roll paper Pr to be held in place so as not to fall when it is set in the paper feeder 20. The separation roller 37 is the separation member in this embodiment.

[0028] The first pivot point 32 is provided at the end of the first support section 31 opposite to the paper feed side (the left side in Figure 2). In this embodiment, the first pivot point 32 is a rotation axis whose axis direction is perpendicular to the plane of Figure 2, and is the pivot point on the plane of Figure 2 (on the plane parallel to the rotation direction of the support plate 30). The first support section 31 and the entire support plate 30 rotate around the first pivot point 32.

[0029] The detection unit 30A can detect the leading edge position of the roll paper Pr by bringing the contact roller 35 and the leading edge detection sensor 36 into contact with the roll paper Pr. A second pivot point 34 is provided at the end of the first support unit 31 opposite to the side where the first pivot point 32 is provided. In the circumferential direction of the roll paper Pr, the contact roller 35 and the leading edge detection sensor 36 are provided at different positions on the first support unit 31. As the support plate 30 is biased toward the roll paper Pr side, the contact roller 35 and the leading edge detection sensor 36 face toward the roll paper Pr side regardless of the roll diameter.

[0030] The contact roller 35 is a roller-shaped roller member. The rotational movement of the contact roller 35 is axial in the direction perpendicular to the plane of the paper in Figure 2. As shown in Figure 3, two contact rollers 35 are provided in the width direction of the support plate 30. By providing multiple contact rollers 35 in the width direction of the support plate 30, lifting of the leading edge Pa of the roll paper Pr from the roll paper Pr body can be suppressed during the leading edge detection operation described later. In addition, a leading edge detection sensor 36 is provided between the two contact rollers 35 in the width direction of the support plate 30. This suppresses deterioration of the detection accuracy of the leading edge detection sensor 36 due to lifting from the roll paper Pr body or curling. Furthermore, by providing the contact rollers 35 and the leading edge detection sensor 36 at different positions on the first support part 31 in the circumferential direction of the roll paper Pr, it is possible to suppress contact between deformed parts such as scratches partially formed on the surface of the roll paper Pr and both the contact rollers 35 and the leading edge detection sensor 36, thereby improving the accuracy of the detection operation of the leading edge Pa of the roll paper Pr described later.

[0031] The second support portion 33 has a second pivot point 34 at one end. In this embodiment, the second pivot point 34 is an axis whose axis is perpendicular to the plane of Figure 2, and is the pivot point on the plane of Figure 2 (on the plane parallel to the rotation direction of the second support portion 33). The second support portion 33 (separation portion 30B) can rotate around the second pivot point 34 relative to the first support portion 31 (detection portion 30A). The separation roller 37 is a roller-shaped roller member. The rotational movement of the separation roller 37 has its axis perpendicular to the plane of Figure 2. Furthermore, the downstream portion of the second support portion 33 in the paper transport direction from the separation roller 37 (the portion opposite to the second pivot point 34 side from the separation roller 37) contacts the paper P separated from the roll paper Pr body, guiding the paper P downstream.

[0032] Figure 4 shows how the first support portion 31 and the second support portion 33 of the support plate 30 rotate according to the diameter of the roll paper Pr, causing the contact roller 35 or the separation roller 37 to come into contact with the roll paper Pr.

[0033] As shown in Figure 4, when the diameter of the roll paper Pr decreases from the dashed line to the solid line in Figure 4 due to consumption during its transport operation, the first support portion 31 rotates around the first pivot point 32 in the direction of arrow Ha1, approaching the roll paper Pr, due to the biasing force of the first biasing means 44. As a result, the contact roller 35 comes into contact with the roll paper Pr. Also, the second support portion 33 rotates relative to the first support portion 31 around the second pivot point 34 in the direction of arrow Hb1, approaching the roll paper Pr, due to the biasing force of the second biasing means 45. As a result, the separation roller 37 comes into contact with the roll paper Pr. In this embodiment, the first biasing means 44 and the second biasing means 45 are torsion springs.

[0034] In this way, the detection unit 30A and the separation unit 30B are biased by their respective biasing means, so that the contact roller 35 or the separation roller 37 can be brought into contact with the surface of the roll paper Pr regardless of the diameter of the roll paper Pr. Also, when the support plate 30 is pushed, such as when a roll of paper with a large diameter is set in the paper feed device 20, the first support unit 31 rotates in the opposite direction to the direction of arrow Ha1 around the first pivot point 32, against the biasing force of the first biasing means 44. Similarly, the second support unit 33 rotates in the opposite direction to the direction of arrow Hb1 around the second pivot point 34, against the biasing force of the second biasing means 45. As a result, the support plate 30 returns to the position shown in Figure 2, for example.

[0035] Figure 5 shows the configuration of the sensor, with (A) being a perspective view and (B) being a side view.

[0036] The tip detection sensor 36 uses, for example, an encoder sensor in which an actuator 361 is provided with a slit 362. The actuator 361 is positioned between two side plates 363 that constitute the sensor housing, and an axis 364 is fitted into the bearings of the side plates 363, allowing it to rotate around the axis 364. The actuator 361 has an asymmetric shape with respect to the axis 364, as shown in Figure 5(B), for example. The tip detection sensor 36 has a light-emitting part and a light-receiving part, and detects the position of the radial outer surface of the roll paper Pr by counting the number of times light passes through the slit 362 of the actuator 361 from the light-emitting part to the light-receiving part (by counting the number of signal waveforms). The tip detection sensor 36 has a resolution of, for example, about 5 μm / pulse and can detect a step difference equal to the thickness of the paper P. The radial direction of the roll paper Pr refers to each direction from the center of the roll paper Pr toward each outer surface on a paper plane such as Figure 2, which is perpendicular to the axial direction of the roll paper Pr.

[0037] Figure 6 is a side view showing the separation roller 37.

[0038] As shown in Figure 6, the separation roller 37 is rotatably mounted around a rotation axis 39. The separation roller 37 is held by a plate-shaped second support portion 33, a part of which is exposed to the roll paper side. More specifically, the portion of the separation roller 37 that contacts the leading edge Pa of the paper P (see Figure 9) and the portion downstream of this portion in the paper transport direction are exposed to the roll paper side (roll paper side relative to the second support portion 33). This allows the leading edge of the paper P that contacts the separation roller 37 to be directed downstream in the paper transport direction by bringing it into contact with the separation roller 37 during paper transport operation, or, in the reverse operation shown in Figure 11 described later, the leading edge Pa of the paper P to be directed towards the transport path side. In addition, the separation roller 37 is biased toward the roll paper side by a biasing means and contacts the roll paper.

[0039] Next, the operation in which the leading edge Pa of the paper P is separated from the roll paper Pr by the separation roller 37 and the paper P is transported will be explained using Figures 7 to 12. In this embodiment, "the leading edge Pa of the paper P (or the leading edge side including the leading edge Pa) is separated from the roll paper Pr" means that, as shown in Figure 8, only a portion of the leading edge Pa side of the paper P is detached from the roll paper Pr body, while the side opposite the leading edge Pa remains continuous with the roll paper Pr body. Also, in Figures 8 to 12 and Figures 17 and 18 described later, the paper P is shown in a thicker shape for convenience so that the leading edge of the roll paper Pr can be distinguished from the roll paper Pr body.

[0040] When starting the paper transport operation, first, as shown in Figure 7, the roll paper Pr is reversed in the direction of arrow B2 to perform the leading edge detection operation of the paper P (details will be described later). Then, as shown in Figure 8, the roll paper Pr is rotated forward in the direction of arrow B1. At this time, if the leading edge Pa of the paper P is in close contact with the roll paper Pr and is not separated, the leading edge Pa of the paper P is not transported toward the transport roller pair 6 and hits the separation roller 37. The leading edge Pa is stopped at the position where it contacts the separation roller 37. By further rotating the roll paper Pr in this state, as shown in Figures 9 to 10, a deflection occurs on the leading edge side of the paper P, and this deflection increases. Then, as shown in Figure 11, by reversing the roll paper Pr in the direction of arrow B2, the leading edge Pa of the paper P separates from the separation roller 37, and the leading edge of the paper P is separated from the roll paper Pr. In this state, as shown in Figure 12, by rotating the roll paper Pr forward again in the direction of arrow B1, the leading edge Pa faces the transport roller pair 6, and the paper feed device can correctly transport the paper P downstream. The reverse operation shown in Figure 11 above is performed when the control unit of the paper feed device determines that the leading edge Pa of the paper P is blocked by the separation roller 37 if the paper P is not detected by the paper feed inlet sensor 43 within a predetermined time.

[0041] In this embodiment, the support plate 30 that supports the roll paper Pr is provided with a separation roller 37 for separating the leading edge Pa of the paper P from the roll paper Pr. Therefore, compared to a configuration in which these components are provided separately, the number of parts in the paper feeding device 20 can be reduced.

[0042] Furthermore, as shown in Figure 4, by providing a second pivot point 34 on the support plate 30 and rotatably mounting the second support portion 33 relative to the first support portion 31, it becomes easier to bring the separation roller 37 into contact with the roll paper Pr. In other words, if the support plate 30 is not provided with a second pivot point 34, and the tip detection sensor 36 and separation roller 37 are brought into contact with the roll paper Pr solely by rotational movement around the first pivot point 32 of the first support portion 31 and the second support portion 33, it becomes difficult to bring both the contact roller 35 and the separation roller 37 into contact with the roll paper Pr when the roll diameter of the roll paper Pr decreases. For this reason, for example, it becomes necessary to position the first pivot point 32 far away from the roll paper Pr, which increases the size of the paper feeding device. In contrast, in this embodiment, in addition to the rotational movement of the first support portion 31 around the first pivot point, the second support portion 33 is rotated around the second pivot point 34, allowing the second support portion 33 to be rotated in a direction even closer to the roll paper Pr than the first support portion 31, and the separation roller 37 can be easily brought into contact with the roll paper Pr. Therefore, the first pivot point 32 can be set in a position close to the roll paper Pr as shown in Figure 4, and the paper feeding device can be miniaturized.

[0043] As described above, the configuration of the support plate 30 in this embodiment allows the leading edge Pa of the paper P to be appropriately separated from the roll paper Pr by the separating roller 37, and also enables miniaturization of the paper feeding device 20. Furthermore, as in the configuration of this embodiment, by integrally providing the separating roller 37 (separating member) for separating the roll paper Pr with respect to the support plate 30 that supports the leading edge detection sensor 36, etc., the area in the circumferential direction of the roll paper Pr where these members are arranged can be reduced. For example, in this embodiment, the support plate 30 is arranged from the lower to the right side of the roll paper Pr in Figure 4, and the left side to the upper side of Figure 4 can be left as an empty space where no support members or separating members are provided. Therefore, the left side and upper side of Figure 4 can be used as a workspace for the operator to set the roll paper Pr. Consequently, the workability of setting the roll paper Pr is improved. Alternatively, the constraints on the layout provided in the image forming apparatus in order to secure a workspace for setting the roll paper Pr can be reduced. As a result, it becomes easy to apply the paper feeding device 20 of this embodiment to an image forming apparatus with straight transport, such as Figure 1, and the image forming apparatus can be miniaturized.

[0044] Furthermore, by using a roller-shaped separating member to separate the paper P, scratches and wear on the surface of the roll paper Pr can be suppressed. In other words, in this embodiment, the separating member is brought into contact with the surface of the roll paper Pr by a biasing means, and the roll paper Pr is rotated forward or backward in this state. Even under these conditions, by using a separating member as a separating roller and reducing the frictional force between the separating member and the roll paper Pr, scratches and wear on the surface of the roll paper Pr can be suppressed. The safety of the operator can also be ensured.

[0045] Furthermore, in this embodiment, as shown in Figure 13, when the leading edge of the paper P is separated from the roll paper Pr and transported downstream in the paper transport direction, the paper P, which is held taut by the downstream transport roller pair 6, etc., comes into contact with the second support part 33 or the separation roller 37 and is pressurized. As a result, the second support part 33 rotates around the second pivot point 34 in a direction away from the roll paper Pr. This reduces or eliminates the frictional force generated between the roll paper Pr and the separation roller 37 during the transport operation of the paper P due to the forward rotation of the roll paper Pr, thereby suppressing wear of the separation roller 37 and the roll paper Pr.

[0046] Furthermore, in this embodiment, the coefficient of friction between the separation roller 37 and the paper P is set to be greater than the coefficient of friction between the paper P sheets themselves. This allows the leading edge Pa of the paper P to be easily separated from the roll paper Pr when it comes into contact with the separation roller 37. For example, the coefficient of friction between the separation roller 37 and the paper P can be made greater than the coefficient of friction between the paper P sheets themselves by appropriately selecting the material of the separation roller 37 or by increasing the surface roughness of the separation roller 37.

[0047] In this embodiment, as shown in Figure 24, multiple support plates 30 having separation rollers 37 may be provided in the width direction of the paper P. Figure 24 illustrates a case where three support plates 30 are provided in the width direction, but there may be two or four or more. Instead of providing multiple support plates 30 in the width direction of the paper P, multiple separation rollers 37 may be provided on the support plates 30 in the width direction of the paper P. With any of these configurations, even for paper P with a large width, the leading edge Pa can be separated from the roll paper Pr more reliably. The width direction of the paper P is the direction along the surface of the paper P, and is perpendicular to the transport direction along the surface of the paper P.

[0048] Next, the separation mechanism, including the separation roller 37 for separating the leading edge of the paper, will be explained in more detail using Figures 14 and 15. Figure 14 is an exploded perspective view of the parts of the separation mechanism, and Figure 15 is a perspective view of the separation mechanism in its assembled state.

[0049] As shown in Figure 14, a separation roller 37 equipped with a torque limiter 40 is inserted into the rotating shaft 39. A one-way clutch 41 and a bearing 42 are attached to the support plate 30 (see Figure 12). As shown in Figure 15, the one-way clutch 41 and bearing 42 are inserted into the rotating shaft 39 having the separation roller 37 and attached to the support plate 30. This allows the separation roller 37, torque limiter 40, one-way clutch 41, and bearing 42 to be integrally mounted on the rotating shaft 39, thus saving space in the paper feeding device 20.

[0050] When the roll paper Pr reverses direction as shown in Figure 7 or Figure 11, the separating roller 37 rotates forward (CW) in the direction indicated by arrow R1 in Figure 15. In other words, the separating roller 37 rotates in the clockwise direction as shown in Figure 11. At this time, the torque limiter 40 locks and rotates the rotating shaft 39. On the other hand, the one-way clutch 41 becomes free, so as to not generate a load for the reverse operation of the roll paper Pr, and there is almost no sliding resistance between the separating roller 37 and the roll paper Pr. Therefore, the load on the drive system of the roll paper Pr during reverse operation is reduced, and wear of the roll paper Pr and the separating roller 37 can be suppressed.

[0051] Furthermore, when the roll paper Pr rotates forward as shown in Figures 8-10 and 12, the separating roller 37 reverses direction (CCW) in the direction indicated by arrow R2 in Figure 15. In other words, the separating roller 37 rotates in the counterclockwise direction as shown in Figure 12. At this time, the one-way clutch 41 is locked. Due to the forward rotation of the roll paper Pr, the separating roller 37 rotates until the leading edge Pa of the paper P reaches the separating roller 37 (to the position in Figure 8). Then, torque is generated by the torque limiter 40, which prevents the leading edge Pa of the paper P from going further than the position in Figure 8 towards the nip side of the separating roller 37 and the roll paper Pr, thereby blocking the leading edge Pa of the paper P.

[0052] Next, the control of the functions of the paper feed device in this embodiment will be explained using Figures 16 and 23. Figure 16 is a functional block diagram illustrating an example of the functions of the paper feed device, and Figure 23 is a hardware block diagram of the control unit.

[0053] The control unit 110 controls the entire paper feeding device. Figure 16 shows an example of a functional block in which the control unit 110 controls the tip detection sensor 36, the paper feed inlet sensor 43, the operation panel 170, the roll drive unit 130, the transport drive unit 150, and the cutter 76, with other functional blocks omitted. The control unit 110 may be provided in the paper feeding device or in the image forming apparatus. In addition, a separate control unit may be provided in the paper feeding device within the image forming apparatus, separate from the control unit of the paper feeding device. For example, the control unit 110 in Figure 1 may be a control unit provided outside the paper feeding device and may control the operation of the entire image forming apparatus, including the paper feeding operation. Similarly, the operation panel 170, which receives input from the user, may also be configured to function as an operation panel for the image forming apparatus.

[0054] As shown in Figure 23, the control unit 110 includes, for example, a CPU (Central Processing Unit) 92, a RAM (Random Access Memory) 93, a ROM (Read Only Memory) 94, a storage unit 95, and the like. The CPU 92, RAM 93, ROM 94, and storage unit 95 are connected via a bus 96.

[0055] The CPU 92 executes various programs and controls the entire image processing unit based on arithmetic processing and control programs. The RAM 93 is a volatile storage medium for high-speed reading and writing of information and functions as a work area when the CPU 92 executes programs. The ROM 94 is a read-only non-volatile storage medium that stores various programs and control programs, including firmware. The storage unit 95 is a non-volatile storage medium that allows reading and writing of information and stores the OS (Operating System), various control programs, and application programs. The storage unit 95 can be, for example, an SSD (Solid State Drive) or an HDD (Hard Disk Drive).

[0056] As shown in Figure 16, the control unit 110 rotates the roll paper Pr in the forward or reverse direction by driving the roll drive unit 130 to rotate the roll shaft 21. The control unit 110 also drives the transport drive unit 150 to drive the transport unit 160. The transport unit 160 is a transport means that transports the paper P supplied from the paper feed device, and is, for example, a pair of transport rollers 6. The detection results from the tip detection sensor 36 and the paper feed inlet sensor 43 are input to the control unit 110.

[0057] Figure 17 is a diagram illustrating an example of operation for detecting the leading edge Pa of the paper P, showing the process by which the leading edge Pa of the paper P passes between the contact roller 35 and the leading edge detection sensor 36.

[0058] Figure 17(A) shows the state before the leading edge Pa of the paper P passes the contact roller 35, Figure 17(B) shows the state after the leading edge Pa of the paper P has passed the contact roller 35 and before it has passed the leading edge detection sensor 36, and Figure 17(C) shows the state after the leading edge Pa of the paper P has passed the leading edge detection sensor 36.

[0059] The tip detection sensor 36 and the contact roller 35 are positioned in close proximity and offset (offset in the circumferential direction of the roll). Since the contact roller 35 is located upstream of the tip detection sensor 36 in the roll paper rotation direction B2, the contact roller 35 can hold the paper P until just before the tip detection sensor 36 detects the leading edge Pa of the paper P.

[0060] As shown in Figure 17(B), when the leading edge Pa of the paper P passes the contact roller 35, a space equal to the thickness of the paper is created between the contact roller 35 and the roll paper Pr, and the support plate 30 moves in the direction of arrow C, approaching the roll paper Pr. As a result, the actuator of the leading edge detection sensor 36 is pushed in the opposite direction by the roll paper Pr and moves in the direction of arrow D1. Then, as shown in Figure 17(C), when the leading edge Pa of the paper P passes the leading edge detection sensor 36, a space is created between the roll paper Pr and the leading edge detection sensor 36, and the actuator of the leading edge detection sensor 36 moves in the direction of arrow D2. This makes it possible to detect the portion of the roll paper Pr surface with a step (difference equal to the paper thickness) as the leading edge Pa of the paper P while the tip of the leading edge detection sensor 36 is in close contact with the surface of the roll paper Pr.

[0061] Figures 18 and 19 illustrate the detection of the leading edge Pa of the paper P based on the sensor output. Figure 18 is an explanatory diagram showing the relationship between the position of the leading edge Pa of the paper P and the change in the sensor output signal, and Figure 19 is an explanatory diagram showing the details of the change in the sensor output signal.

[0062] As shown in Figure 18(A), Figure 18(B) shows the sensor output signals obtained when the leading edge Pa of the paper P passes the contact roller 35 (up to the dotted line E1) is designated as "I", the leading edge Pa of the paper P passes the contact roller 35 and then the leading edge detection sensor 36 (from the dotted line E1 to the dotted line E2) is designated as "II", and the leading edge Pa of the paper P passes the leading edge detection sensor 36 (from the dotted line E2 onwards) is designated as "III".

[0063] In detecting the leading edge Pa of the paper P, the roll paper Pr is first reversed in the B2 direction (CW), and the sensor displacement output K1 per unit time when the leading edge Pa of the paper P passes the contact roller 35 (dotted line E1) and the sensor displacement output K2 per unit time when the leading edge Pa of the paper P passes the leading edge detection sensor 36 (dotted line E2) are detected. The detection of the leading edge Pa of the paper P is considered to have occurred based on the detection of K1 and K2. By considering the detection of the leading edge Pa of the paper P to have occurred if the sensor displacement output K2 is detected immediately after the detection of the sensor displacement output K1 within a set time (T1), false detections due to scratches or other irregularities on the surface of the roll paper Pr can be prevented.

[0064] Furthermore, T1 can be expressed by the following formula. T1 = (Circumferential distance from roller member to sensor (mm)) ÷ (Linear velocity at paper leading edge (mm / s)) + (Setting margin) The line speed at the leading edge of the paper can also be expressed as the motor rotation speed (rotational speed).

[0065] If the leading edge Pa of the paper P is not detected during one rotation of the roll paper Pr, the detection accuracy can be improved by repeating the same detection operation a predetermined number of times, and by making the number of repetitions configurable. The flow of the detection operation will be described later.

[0066] Furthermore, in a configuration where two or more contact rollers 35 are arranged along the roll axis direction, as in the example in Figure 3, if the leading edge Pa of the paper P to be detected is at an angle to the roll axis direction, a difference in timing may occur in the passage of the leading edge Pa of the paper P over each contact roller 35, making it difficult to detect the sensor displacement output K1. In such cases, if the leading edge Pa of the paper P is not detected even after repeating the detection operation a predetermined number of times, the detection accuracy can be improved by detecting only the sensor displacement output K2 when the leading edge Pa of the paper P passes over the leading edge detection sensor 36.

[0067] Furthermore, when detecting the leading edge Pa of the paper P solely by detecting the sensor displacement output K2, detection accuracy can be improved by defining the detection of the leading edge Pa of the paper P as occurring when the sensor displacement output K2 is detected again within a certain time range (T2) corresponding to the cycle of one roll rotation after the first K2 detection, and by allowing the number of detection operations to be arbitrarily set.

[0068] After detecting the leading edge Pa of the paper P, the leading edge Pa of the paper P is stopped at a predetermined position, and the roll paper Pr is switched to a counter-clockwise (CCW) rotation. This suppresses variations in the orientation of the paper P during transport, allowing for stable transport of the paper downstream regardless of its condition (curl / paper type / paper thickness).

[0069] Figures 20 to 22 are flowcharts illustrating the flow from setting the roll paper Pr to starting the paper transport operation in the paper feeding device of this embodiment, with Figure 20 being a flowchart of the overall flow.

[0070] As shown in Figures 16 and 20, when the control unit 110 detects that the roll paper Pr has been set in the paper feed device (S001), it controls the roll drive unit 130 to reverse the rotation of the roll paper Pr. The setting of the roll paper Pr is detected, for example, by the detection result of the tip detection sensor 36. The roll paper rotation motor (roll drive unit 130) rotates the roll paper Pr in the winding direction in reverse operation (S002), and the tip detection sensor 36 starts tip detection operation (S003).

[0071] The control unit 110 determines whether the tip detection is complete (S004), and if not, it performs the flow shown in Figure 21, connected by connector A. The detailed flow of the tip detection operation is shown in Figures 21 and 22 and will be described later. The control unit 110 returns to this flow by connecting with connector B in Figure 21. After the tip Pa of the paper P is detected, the control unit 110 stops the roll paper rotation motor when the tip Pa of the paper P reaches a predetermined position (paper tip stop position) (S005). Next, the control unit 110 controls the roll drive unit 130 to rotate the roll paper Pr in the forward direction (S006). Then, within a predetermined time T3 from the start of the forward rotation operation, the control unit 110 determines whether the paper feed inlet sensor 43 detects paper (S007). If paper is detected, a paper transport operation is performed to transport the paper P unfurled from the roll paper Pr to the downstream side (S008). The control unit 110 rotates the transport unit 160 to transport the paper to the downstream side of the paper feed device.

[0072] On the other hand, if no paper is detected, the paper leading edge separation operation shown in Figures 8 to 12 above is performed (S009). Then, it is determined again whether the paper feed inlet sensor 43 has detected paper within a predetermined time T4 (S010). If paper is detected, the paper transport operation is started (S008). If no paper is detected, it is determined that there is a transport abnormality, the rotation of the roll paper Pr is stopped, and the transport operation is terminated.

[0073] Figure 21 shows a detailed flow of the tip detection operation connected by connector A from step S004 in Figure 20.

[0074] First, the detection count of the leading edge Pa of the paper P starts at N=0 (S101), and it is determined whether the sensor displacement output K1 has been detected (S102). After detecting K1, it is determined whether K2 has been detected within T1 (S103). "T1" is the time calculated based on the motor rotation speed and the distance from the contact roller to the sensor, plus a set margin. If K2 is detected, the detection count of the leading edge Pa of the paper P N is increased by 1 (S104).

[0075] Next, it is determined whether the number of detections N for the leading edge Pa of the paper P is equal to or greater than the set value a (S105). "a" is the reference value for the number of detections required to determine that detection of the leading edge Pa of the paper P is successful (how many detections are needed for detection to be considered successful). If N is equal to or greater than a, the detection of the paper leading edge is considered successful (S106). The subsequent flow is connected to step S005 in Figure 20 by connector B.

[0076] On the other hand, if N is less than a in step S105, it is determined whether K1 was detected again within T2 after the initial K1 detection (S107). "T2" is the time calculated based on the motor rotation speed plus a set margin for one rotation of the roll paper. If K1 is detected, it is then determined whether K2 was detected within T1 (S108). If K2 is detected, the detection count of the leading edge Pa of the paper P is increased by 1 (S104).

[0077] If K1 is not detected in step S107, if K2 is not detected in step S108, and if K2 is not detected in step S103, it is determined whether the roll paper Pr has rotated M times or more (S109). "M" is the set value for the number of rotations of the roll paper Pr (how many times the roll paper Pr is rotated before the leading edge Pa of the paper P is detected). If the cumulative number of rotations is less than M, the process returns to the flow from step S102. On the other hand, if the cumulative number of rotations is M times or more, the flow shown in Figure 22, connected by connector E, is performed.

[0078] Figure 22 shows a detailed flow of the tip detection operation connected by connector E from step S109 in Figure 21.

[0079] First, the process starts again from tip detection count N=0 (S201), and it is determined whether the sensor displacement output K2 has been detected (S202). If K2 is detected, the detection count N for the tip Pa of the paper P is increased by 1 (S203).

[0080] Next, it is determined whether the number of detections N for the leading edge Pa of the paper P is equal to or greater than the set value a (S204). "a" is the reference value for the number of detections required to determine that detection of the leading edge Pa of the paper P is successful (how many detections are needed for detection to be considered successful). If N is equal to or greater than a, the detection of the paper leading edge is considered successful (S205). The subsequent flow is connected to step S005 in Figure 20 by connector B.

[0081] On the other hand, if N is less than a in step S204, it is determined whether K2 was detected again within T2 after the initial K2 detection (S206). "T2" is the time calculated based on the motor rotation speed, plus a set margin. If K2 is detected, the detection count of the leading edge Pa of the paper P is increased by 1 (S203), and the process returns to the subsequent flow.

[0082] If K2 is not detected in step S206, and if K2 is not detected in step S202, it is determined whether the roll paper has rotated M times or more (S207). "M" is the set value for the number of roll paper rotations (how many times the roll paper is rotated before detecting the leading edge Pa of the paper P). If the cumulative number of rotations is less than M, the process returns to step S202. On the other hand, if the cumulative number of rotations is M or more, it is determined that detection of the leading edge Pa of the paper P has failed, and the roll paper rotation motor is stopped (S208).

[0083] As a result of the above process, the leading edge Pa of the paper P can be reliably detected automatically simply by the user setting the roll paper Pr in the paper feeder, and the dispensed paper P can be stably transported downstream.

[0084] Although embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the present invention.

[0085] The image forming apparatus according to the present invention is not limited to the color image forming apparatus shown in Figure 1, but may also be a monochrome image forming apparatus, a copier, a printer, a facsimile, or a combination device thereof.

[0086] The media used include plain paper (P), as well as cardboard, postcards, envelopes, thin paper, coated paper (such as coated paper and art paper), tracing paper, OHP sheets, plastic film, prepreg, copper foil, and others.

[0087] Examples of the present invention are as follows: <1> Equipped with a support member, A media feeding device that rotates a roll-shaped body in which a sheet-like medium is wound into a roll, thereby unwinding the medium from the roll-shaped body and conveying it downstream in the media conveying direction, The aforementioned support member is A detection member that contacts the roll-shaped body and detects the tip of the roll-shaped body, A first support portion that supports the detection member, The first pivot point, which is the pivot point for the rotational movement of the first support part, Separating member and A second support portion that supports the aforementioned separation member, The second support portion comprises a second pivot point which is the pivot point for the rotational movement of the second support portion relative to the first support portion, The separating member contacts the tip of the roll-shaped body and separates the tip from the roll-shaped body. The detection member comes into contact with the roll-shaped body due to rotation of the first support portion around the first pivot point. A media feeding device characterized in that the separating member comes into contact with the roll-shaped body by rotation of the second support portion around the second pivot point. <2> The separation member is a rotating roller-shaped separation roller. <1> The media supply device described. <3> The support member has a roller-shaped contact roller that contacts the surface of the roll-shaped body, The first support portion supports the contact roller at a position different from the detection member in the circumferential direction of the roll-shaped body. <1> or <2> The media supply device described. <4> When the medium, separated from the roll-shaped body and being transported, comes into contact with the separating member or the second support portion, the second support portion rotates about the second pivot point in a direction away from the roll-shaped body side. <1> from <3> Any of the media supply devices described above. <5> The coefficient of friction between the separating member and the medium is greater than the coefficient of friction between the mediums themselves. <1> from <4> Any of the media supply devices described above. <6> A torque limiter is provided on the separation member. <2> or <2> related <3> from <5> Any of the media supply devices described above. <7> A one-way clutch is provided on the separation member. The one-way clutch locks the roll-shaped body when it is rotated in the direction of conveying the medium, and frees it when it is rotated in the direction opposite to the direction of conveying the medium. <2> or <2> related <3> from <6> Any of the media supply devices described above. <8> The separation member, torque limiter, and one-way clutch are integrally provided via a shaft. <7> The media supply device described. <9> The separation member is provided such that the portion that contacts the leading edge of the medium and the portion downstream of that portion in the medium transport direction are exposed to the roll-shaped body side of the second support portion. <1> from <8> Any of the media supply devices described above. <10> After detecting the leading edge position of the roll-shaped body, the roll-shaped body is rotated in the following order: in the direction of conveying the medium, in the opposite direction to the direction of conveying the medium, and in the direction of conveying the medium. <1> from <9> Any of the media supply devices described above. <11> Multiple separation members are provided in the width direction of the medium. <1> from <10> Any of the media supply devices described above. <12> <1> from <11> An image forming apparatus comprising a media feeding device as described in any of the above, and which forms an image on the medium. [Explanation of symbols]

[0088] 20. Paper feed device (media feed device) 30. Support plate (support member) 30A detection unit 30B Separation part 31 1st support part 32 First pivot point 33 Second support part 34 Second pivot point 35 Contact roller 36. Advanced detection sensor (detection component) 37 Separation roller (separation member) 80 Image forming apparatus A. Paper transport direction (media transport direction) B1 Forward rotation direction of roll paper (direction of rotation for transporting the medium in roll form) B2 Reverse direction of roll paper (rotation direction opposite to the direction in which the medium in the roll is transported) P paper (sheet-like medium) Pr Roll Paper (Roll-shaped material) [Prior art documents] [Patent Documents]

[0089] [Patent Document 1] Japanese Patent Publication No. 2024-80480

Claims

1. Equipped with a support member, A media feeding device that rotates a roll-shaped body in which a sheet-like medium is wound into a roll, thereby unwinding the medium from the roll-shaped body and conveying it downstream in the media conveying direction, The aforementioned support member is A detection member that contacts the roll-shaped body and detects the tip of the roll-shaped body, A first support portion that supports the detection member, The first pivot point, which is the pivot point for the rotational movement of the first support part, Separating member and A second support portion that supports the aforementioned separation member, The second support portion comprises a second pivot point which is the pivot point for the rotational movement of the second support portion relative to the first support portion, The separating member contacts the tip of the roll-shaped body and separates the tip from the roll-shaped body. The detection member comes into contact with the roll-shaped body due to rotation around the first pivot point of the first support portion. A media feeding device characterized in that the separating member comes into contact with the roll-shaped body by rotation of the second support portion around the second pivot point.

2. The media feeding device according to claim 1, wherein the separating member is a rotating roller-shaped separating roller.

3. The support member has a roller-shaped contact roller that contacts the surface of the roll-shaped body, The media feeding device according to claim 1, wherein the first support portion supports the contact roller at a position different from the detection member in the circumferential direction of the roll-shaped body.

4. The medium feeding device according to claim 2, wherein the medium, which is separated from the roll-shaped body and transported, comes into contact with the separating member or the second support, causing the second support to rotate about the second pivot point in a direction away from the roll-shaped body side.

5. The medium feeding device according to claim 2, wherein the coefficient of friction between the separating member and the medium is greater than the coefficient of friction between the mediums themselves.

6. The medium feeding device according to claim 2, wherein a torque limiter is provided on the separating member.

7. A one-way clutch is provided on the separation member. The medium feeding device according to claim 2, wherein the one-way clutch locks the roll-shaped body when it is rotated in the direction for conveying the medium, and frees the roll-shaped body when it is rotated in the direction opposite to the direction for conveying the medium.

8. The media feeding device according to claim 7, wherein the separating member, the torque limiter, and the one-way clutch are integrally provided via a shaft.

9. The media feeding device according to claim 2, wherein the portion of the separating member that contacts the leading edge of the medium and the portion downstream of that portion in the direction of media transport are exposed to the roll-shaped body side of the second support portion.

10. The medium feeding device according to claim 1, wherein, after detecting the tip position of the roll-shaped body, the roll-shaped body is rotated in the order of the direction in which the medium is transported, the direction opposite to the direction in which the medium is transported, and the direction in which the medium is transported.

11. The medium feeding device according to claim 1, wherein a plurality of the separating members are provided in the width direction of the medium.

12. An image forming apparatus comprising a medium feeding device according to any one of claims 1 to 11, wherein an image is formed on the medium.

Images