Feeding mechanism and image forming apparatus

Abstract

To enable confirmation of a success or a failure of cutting a sheet medium.SOLUTION: When tension is applied to a roll sheet Rp, a feeding roller 2 and an arm 2a, which contact an upper surface of the roll sheet Rp upstream of a cutting portion 4 and a pair of intermediate roller pairs 31 in a transportation path, are lifted up by the roll sheet Rp. At this time, an actuator 73a does not block a light path of a sensor 73b (sensor-OFF-state). When cutting of the roll sheet Rp by the cutting portion 4 succeeds, the feeding roller 2 and the arm 2a are displaced downward as the tension of the roll sheet Rp decreases, and the actuator 73a blocks the light path of the sensor 73b (sensor-ON-state).SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to a feeding mechanism including a cutting unit for cutting a sheet-like medium and an image forming apparatus including the same.

Background Art

[0002] There is known an image forming apparatus that forms an image while conveying a sheet-like medium such as paper, cloth, or a label along a conveyance path from a roll body in which the sheet-like medium is wound in a roll shape. As such an image forming apparatus, Patent Document 1 discloses an inkjet recording apparatus including a roll paper storage unit and a sheet cutting device (cutting unit).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a feeding mechanism and an image forming apparatus including a cutting unit as in Patent Document 1, cutting of the medium by the cutting unit may fail, and the medium may not be separated forward and backward at the cutting location. However, the inkjet recording apparatus of Patent Document 1 does not have a means for confirming whether the cutting of the medium by the cutting unit is successful. Therefore, even though the cutting of the medium has failed, conveyance and / or image formation will continue as if it has been successful.

[0005] An object of the present invention is to provide a feeding mechanism capable of confirming whether cutting of a sheet-like medium is successful and an image forming apparatus including the same.

Means for Solving the Problems

[0006] The feeding mechanism according to the present invention comprises a storage section capable of accommodating a long sheet-like medium, a pair of transport rollers for transporting the sheet-like medium supplied from the storage section along a transport path, a cutting section for cutting the sheet-like medium transported by the pair of transport rollers, a displacement member that contacts the upper surface of the sheet-like medium upstream of the cutting section and the pair of transport rollers in the transport path and displaces downward as the tension applied to the sheet-like medium decreases, and a detection section for detecting the position of the displacement member.

[0007] Furthermore, the image forming apparatus according to the present invention comprises the above-described feeding mechanism and an image forming unit which forms an image on a sheet-like medium downstream of the transport roller pair in the transport path. [Effects of the Invention]

[0008] According to the present invention, if the cutting unit successfully cuts the sheet-like medium, the tension of the sheet-like medium decreases, causing the displacement member to displace downward. However, if the cutting is unsuccessful, the amount of displacement of the displacement member will be smaller than in the case of success. Therefore, the success or failure of the cutting of the sheet-like medium can be confirmed based on the position of the displacement member detected by the detection unit. [Brief explanation of the drawing]

[0009] [Figure 1] This figure shows a printer according to one embodiment of the present invention with a roll of paper stored inside. [Figure 2] This figure shows the printer with cut paper loaded into it, as shown in Figure 1. [Figure 3] Figure 1 is a schematic diagram showing the back tension mechanism included in the printer shown. [Figure 4] (a) A diagram showing the state of the roll detection unit when no roll is stored in the roll storage unit of the printer shown in Figure 1, and (b) A diagram showing the state of the roll detection unit when a roll is stored. [Figure 5](a) A diagram showing the state of the cut paper detection unit when no cut paper is loaded into the cut paper storage section of the printer shown in Figure 1, and (b) A diagram showing the state of the cut paper detection unit when cut paper is loaded. [Figure 6] (a) A diagram showing the state of the first paper presence detection unit when no cut paper is set in the cut paper storage section of the printer shown in Figure 1, and (b) A diagram showing the state of the first paper presence detection unit when cut paper is properly set. [Figure 7] (a) A diagram showing the state of the first paper presence detection unit before the roll of paper is cut, and (b) A diagram showing the state of the second paper presence detection unit before the roll of paper is cut. [Figure 8] (a) A diagram showing the state of the first paper presence detection unit when the roll of paper is partially cut, and (b) A diagram showing the state of the second paper presence detection unit when the roll of paper is partially cut. [Figure 9] (a) A diagram showing the state of the first paper presence detection unit when the roll of paper has been completely cut, and (b) A diagram showing the state of the second paper presence detection unit when the roll of paper has been completely cut. [Figure 10] (a) A diagram showing the state of the first paper presence detection unit when there is no roll paper, and (b) A diagram showing the state of the second paper presence detection unit when there is no roll paper. [Figure 11] Figure 1 is a flowchart showing the printing operation on roll paper in the printer shown. [Modes for carrying out the invention]

[0010] (Overall printer configuration) A printer 100 (corresponding to the "image forming apparatus" of the present invention) including a feeding mechanism according to a preferred embodiment of the present invention will be described below with reference to the drawings. The vertical, horizontal, and front-to-back directions shown in Figures 1 and 2 refer to the vertical, horizontal, and front-to-back directions of the printer 100.

[0011] As shown in Figures 1 and 2, the printer 100 includes a housing 100a, a feed tray 1, a feed unit 20, a transport unit 30, a cutting unit 4, a head 5, a paper output tray 6, a roll detection unit 71, a cut paper detection unit 72, a first paper presence / absence detection unit 73, a second paper presence / absence detection unit 74, a notification unit 8, and a control unit 10. In Figures 1 and 2, the roll detection unit 71, the first paper presence / absence detection unit 73, and the second paper presence / absence detection unit 74 are simplified in their illustration. Note that the first paper presence / absence detection unit 73 and the second paper presence / absence detection unit 74 are simplified and depicted as a single unit in Figures 1 and 2, but as will be described later, they are actually arranged separately on the left and right sides.

[0012] The feed tray 1 is detachable from the lower part of the housing 100a. The feed tray 1 is located below the head 5 within the housing 100a. The feed tray 1 can be inserted into and removed from the housing 100a in the front-rear direction through an opening 101 formed in the front wall of the housing 100a.

[0013] The feeding tray 1 has a box-shaped main body 1a consisting of a bottom wall 18 and four side walls 19 erected on the edge of the bottom wall 18 (in Figures 1 and 2, only the two side walls 19 provided on the front and rear edges of the bottom wall 18 are shown). The feeding tray 1 is capable of accommodating rolls R and cut paper Kp. As shown in Figure 1, the feeding tray 1 has a roll body accommodating section 11a (the "accommodating section" of the present invention) capable of accommodating rolls R, and as shown in Figure 2, a cut paper accommodating section 11b capable of accommodating multiple layers of cut paper Kp.

[0014] As shown in Figure 1, the roll body R is a long, flexible sheet of paper (the "sheet-like medium" of the present invention) wound in a roll around a core member Rc. The cut paper Kp is a shorter sheet of paper than the long sheet of paper that makes up the roll body R, for example, A4 or B5 size paper. In the following description, when the roll paper Rp and the cut paper Kp unwound from the roll body R are not distinguished, they may be referred to as "paper P". In Figure 1, the leading edge of the roll paper Rp is located below the roll body R.

[0015] The roll body housing portion 11a houses the roll body R in a posture where the width direction of the roll paper Rp unwound from the roll body R coincides with the left - right direction. That is, the roll body R is arranged such that the axial direction (the direction perpendicular to the paper surface of FIG. 1) along its rotation axis Rx (the central axis of the core member Rc) is parallel to the left - right direction. The roll body housing portion 11a has two rollers 14, 15, a roll cover 16, and a back - tension mechanism 13. The two rollers 14, 15 both extend in the left - right direction and are arranged at a distance from each other in the front - rear direction. The rollers 14, 15 are each rotatable around a rotation axis extending along the left - right direction. The rollers 14, 15 support the roll body R from below in a state of contacting the outer peripheral surface of the lower portion of the roll body R. In FIGS. 1 and 2, the back - tension mechanism 13 is shown in a simplified manner.

[0016] The roll cover 16 is a member that covers the roll body R housed in the roll body housing portion 11a. The roll cover 16 is detachable from the main body portion 1a or is configured to be rotatable around a rotation axis (not shown) extending along the left - right direction with respect to the main body portion 1a. By detaching the roll cover 16 from the main body portion 1a or rotating it with respect to the main body portion 1a, the accommodation space of the roll body R can be exposed.

[0017] As shown in FIG. 3, the back - tension mechanism 13 includes an upper roller 13a that is driven to rotate around an axis extending in the left - right direction, a lower roller 13b disposed directly below the upper roller 13a, a support 13c that rotatably supports the lower roller 13b from below, and an elastic member 13d that biases the support 13c upward. The rotation axis of the upper roller 13a does not move vertically with respect to the main body portion 1a. The support 13c and the elastic member 13d are supported by the bottom wall 18 of the main body portion 1a. The roll paper Rp unwound from the roll body R passes between the upper roller 13a and the lower roller 13b. Since the elastic member 13d biases the support 13c upward, a constant pressure is always applied to the roll paper Rp sandwiched between the upper roller 13a and the lower roller 13b.

[0018] The cut paper storage section 11b is located behind the roll storage section 11a. The cut paper storage section 11b stores the cut paper Kp in a position where the longitudinal direction of the cut paper Kp coincides with the left-right direction and the width direction coincides with the front-back direction. As shown in Figure 2, the cut paper storage section 11b has a support plate 17 that can support the multiple stacked cut paper Kp from below.

[0019] The support plate 17 is positioned opposite the bottom wall 18 of the feeding tray 1. A protruding projection 18a is formed in the center of the left-right direction at the rear end (right end in Figures 1 and 2) of the bottom wall 18 of the feeding tray 1. A notch 17a is formed in the center of the left-right direction at the rear end (right end in Figures 1 and 2) of the support plate 17. When the support plate 17 is in the parallel position described later, the upper surface of the protruding projection 18a formed on the bottom wall 18 is located within the notch 17a. The protruding projection 18a within the notch 17a and the support plate 17 are separated in the front-rear direction, and a gap G is provided between them. As described later, a part of the actuator 73a of the first paper presence detection unit 73 (see Figure 6(a)) can enter and exit through this gap G. A through hole 17b that penetrates in the vertical direction is formed near the rear end of the support plate 17. As will be described later, a portion of the actuator 72a of the cut paper detection unit 72 (see Figure 5(a)) can enter and exit the through-hole 17b.

[0020] As shown in Figures 1 and 2, the support plate 17 has a pivot shaft 17c at its front end that protrudes in the left-right direction. The support plate 17 is pivotably supported on the feeding tray 1 via the pivot shaft 17c. The support plate 17 is configured to pivot between a parallel position (see Figure 1) where the support plate 17 and the bottom wall 18 are parallel, and a non-parallel position where the rear end of the support plate 17 is positioned above the front end. The support plate 17 is positioned in the parallel position when its front end abuts against the lower end of the roll cover 16. Even when the support plate 17 is in the parallel position, a passage 18b is formed between the support plate 17 and the bottom wall 18, through which the roll paper Rp can pass.

[0021] The feeding unit 20 (the "displacement member" of the present invention) includes a feeding roller 2 and an arm 2a. The arm 2a (the "roller support" of the present invention) is pivotably supported on a pivot shaft 2b of a support part 100b provided on the housing 100a. The pivot shaft 2b is supported by the housing 100a. The arm 2a is biased by a biasing member (not shown) so that the feeding roller 2 approaches the bottom wall 18 of the feeding tray 1. The feeding roller 2 is rotatably supported at the tip of the arm 2a and rotates by the drive of a feeding motor (not shown). The feeding roller 2 feeds paper P from the feeding tray 1 towards the transport path. The transport path is defined by the intermediate roller pair 31, the PF (Paper Feed) roller pair 32, and the discharge roller pair 33, which will be described later.

[0022] In Figure 1, the feed roller 2 is positioned above a protrusion 18a formed on the bottom wall 18. When there is no paper P on the upper surface of the protrusion 18a, the feed roller 2 contacts the upper surface of the protrusion 18a. When there is paper P on the upper surface of the protrusion 18a, the feed roller 2 contacts the paper P. When the feed roller 2 is in contact with the paper P, the feed motor is driven by the control unit 10, causing the feed roller 2 to rotate and applying a transport force to the paper P in contact with the feed roller 2 in a forward-to-backward direction. As a result, the paper P is fed from the feed tray 1.

[0023] A separator piece 7 is positioned at the rear of the feed tray 1. The separator piece 7 prevents double feeding when the feed roller 2 feeds cut paper Kp from the feed tray 1. The separator piece 7 is inclined so that its rear end is positioned higher than its front end. The separator piece 7 contacts the center of the cut paper Kp in the width direction, separating the cut paper Kp that contacts the feed roller 2 from the rest of the cut paper Kp. Paper P that is fed out of the feed tray 1 and comes into contact with the separator piece 7 is guided diagonally upward.

[0024] The transport unit 30 transports the paper P fed from the feed tray 1 by the feed roller 2 so that the paper P passes through a position facing the head 5 (described later) and is sent to the output tray 6. In the following description, the direction in which the transport unit 30 transports the paper P from the feed tray 1 to the output tray 6 will be simply referred to as the "transport direction".

[0025] The transport unit 30 includes an intermediate roller pair 31 (the "transport roller pair" of the present invention), a PF roller pair 32, and a discharge roller pair 33. The intermediate roller pair 31 consists of a drive roller that rotates by the drive of an intermediate motor (not shown) and a driven roller that rotates along with the drive roller. When the intermediate motor is driven by the control unit 10, the intermediate roller pair 31 rotates while gripping the paper P and transports the paper P. The intermediate roller pair 31 is located above the rear end of the feed tray 1. The intermediate roller pair 31 transports the paper P that is fed out of the feed tray 1 by the feed roller 2 and moving diagonally upward while gripping it.

[0026] The PF roller pair 32 is located behind the head 5, and the discharge roller pair 33 is located in front of the head 5. The PF roller pair 32 consists of a drive roller that rotates by the drive of a transport motor (not shown) and a driven roller that moves along with the drive roller. The PF roller pair 32 transports the paper P forward while gripping it, after it has been transported upward by the intermediate roller pair 31 and then guided forward by a guide (not shown). The discharge roller pair 33 consists of a drive roller that rotates by the drive of a paper discharge motor (not shown) and a driven roller that moves along with the drive roller. When the transport motor and paper discharge motor are driven by the control unit 10, the PF roller pair 32 and the discharge roller pair 33 rotate while gripping the paper P and transport the paper P.

[0027] The cutting unit 4 is located in the housing 100a. The cutting unit 4 is positioned between the rear end of the feed tray 1 and the intermediate roller pair 31. In this embodiment, the cutting unit 4 includes a fixed blade 4a that is elongated in the left-right direction and a disc-shaped rotating blade 4b that is movable in the left-right direction while in contact with the fixed blade 4a. The rotating blade 4b reciprocates along the left-right direction by the drive of a cutting motor (not shown) controlled by the control unit 10. As the rotating blade 4b moves in either the left or right direction, it receives a rotational moment from the roll paper Rp and the fixed blade 4a and rotates in a driven manner. The roll paper Rp, which has been unwound from the roll body R and transported, is cut in the width direction by the cutting unit 4. As a result, a rear end is formed on the roll paper Rp that is sent to the paper output tray 6.

[0028] The head 5 (the "image forming unit" of the present invention) includes a plurality of nozzles (not shown) formed on its lower surface and a driver IC (not shown). The head 5 is located downstream of the PF roller pair 32 in the transport direction. When the driver IC is driven by the control unit 10, ink is ejected from the nozzles, and an image is formed (printed) on the paper P when the paper P transported by the transport unit 30 passes a position facing the lower surface of the head 5. The head 5 may be either a line type that ejects ink from nozzles while its position is fixed, or a serial type that ejects ink from nozzles while moving in the left-right direction.

[0029] The output tray 6 forms the front side wall of the upper part of the housing 100a and can be opened and closed relative to the housing 100a. The paper P on which the image has been formed by the head 5 is transported forward by the transport unit 30 and received in the open output tray 6. As a result, the paper P is ejected from the printer 100 (inside the housing 100a).

[0030] To set a roll of paper Rp in the feed tray 1, first the feed tray 1 is pulled out from the housing 100a, the roll cover 16 is operated to expose the space for storing the roll body R in the roll body storage section 11a, and the roll body R is supported by the rollers 14 and 15. Next, the roll of paper Rp is fed backward through the passage 18b until the leading edge of the roll of paper Rp, unwound from the roll body R, reaches the upper surface of the protrusion 18a, or behind the protrusion 18a. After that, the roll body R is covered with the roll cover 16 and the feed tray 1 is inserted into the housing 100a. As a result, the roll of paper Rp is set in the feed tray 1, the feed rollers 2 come into contact with the roll of paper Rp, and the machine becomes ready to feed the roll of paper Rp.

[0031] In the printer 100 of this embodiment, if cut paper Kp is stored in the cut paper storage section 11b, the roll paper Rp cannot be fed. Therefore, when feeding the roll paper Rp, the cut paper Kp stored in the cut paper storage section 11b is removed. On the other hand, when feeding cut paper Kp, the roll body R is removed from the roll body storage section 11a, or the leading edge of the roll paper Rp is positioned within the passage 18b.

[0032] When setting cut paper Kp into the feed tray 1, first the feed tray 1 is pulled out from the housing 100a, and multiple sheets of cut paper Kp are placed on the support plate 17 of the cut paper storage section 11b in a stacked state. Then, the feed tray 1 is inserted into the housing 100a. This sets the cut paper Kp in the feed tray 1, the feed roller 2 comes into contact with the cut paper Kp, and the cut paper Kp becomes ready to be fed. Since the cut paper Kp is stored in the cut paper storage section 11b with its width direction aligned with the front-to-back direction, the cut paper Kp that is fed backward by the feed roller 2 is transported by the transport section 30 with its width direction aligned with the transport direction.

[0033] The notification unit 8 is for performing notification operations to notify the user of information. For example, the notification unit 8 is a display provided on the printer 100 that performs a notification operation to the user by displaying the information to be notified to the user. As a variation, the notification unit 8 may be a speaker provided on the printer 100 that performs a notification operation to the user by emitting the information to be notified to the user in voice. As another variation, the notification unit 8 may output a notification signal to a terminal device connected to the printer 100 by wire or wireless.

[0034] The control unit 10 is connected via an internal bus (not shown) to the feeding motor, intermediate motor, transport motor, paper discharge motor, cutting motor, driver IC, roll detection unit 71, cut paper detection unit 72, first paper presence / absence detection unit 73, second paper presence / absence detection unit 74, notification unit 8, etc. The control unit 10 has a CPU (Central Processing Unit), ROM (Read Only Memory), and RAM (Random Access Memory). The ROM stores programs and data for the CPU to perform various controls. The RAM temporarily stores data used by the CPU when executing programs.

[0035] When the control unit 10 receives a print command, it controls various parts within the printer 100 to execute a print operation on cut paper Kp or roll paper Rp. The receipt of a print command is achieved by the user inputting a print command by operating an operation unit (buttons or touch panel) of the printer 100 (not shown), or by receiving a print command from a terminal device connected to the printer 100 by wire or wireless connection. The print operation on roll paper Rp includes a cutting operation by the cutting unit 4, which cuts the roll paper Rp to a length determined based on the print command.

[0036] In this embodiment, the roll housing section 11a, the intermediate roller pair 31, the cutting section 4, the feeding roller 2 and arm 2a, the first paper presence detection section 73 and the second paper presence detection section 74, and the back tension mechanism 13 constitute the feeding mechanism of the present invention.

[0037] (Details of the detection unit) Next, the details of the roll detection unit 71, the cut paper detection unit 72, the first paper presence / absence detection unit 73, and the second paper presence / absence detection unit 74 will be explained with reference to Figures 4 to 10.

[0038] The roll detection unit 71 can detect whether or not a roll R is stored in the roll storage section 11a of the feed tray 1. More specifically, the roll detection unit 71 detects that the roll R is stored in the roll storage section 11a by detecting the roll paper Rp that has been unwound from the roll R. As shown in Figure 4, the roll detection unit 71 is located below and behind the roller 15 of the roll storage section 11a. Note that the back tension mechanism 13 is not shown in Figure 4.

[0039] As shown in Figure 4, the roll detection unit 71 includes an actuator 71a and a sensor 71b. The actuator 71a is rotatably supported around a rotation axis 71a2. The axial direction of the rotation axis 71a2 is parallel to the left-right direction. The sensor 71b is a sensor that detects the actuator 71a. The sensor 71b is, for example, a photosensor having a light-emitting element and a light-receiving element (not shown). The actuator 71a is biased in the counterclockwise direction in Figure 4 by its own weight, and when no external force is applied, it is located in the delivery path of the roll paper Rp from the roll storage unit 11a, as shown in Figure 4(a). At this time, the actuator 71a does not obstruct the optical path of the sensor 71b.

[0040] As shown in Figure 4(a), when the roll body R is not housed in the roll body housing section 11a, no external force is applied to the actuator 71a, and the actuator 71a is positioned so as not to obstruct the optical path of the sensor 71b. On the other hand, when the roll body R is housed in the roll body housing section 11a, and the roll paper Rp unwound from the roll body R comes into contact with the actuator 71a, as shown in Figure 4(b), the actuator 71a is pushed downward by the roll paper Rp. As a result, the actuator 71a rotates clockwise around the rotation axis 71a2 in Figure 4, and the optical path of the sensor 71b is obstructed. This allows the roll body detection section 71 to detect that the roll body R is housed in the roll body housing section 11a, and more specifically, that the rear end of the roll paper Rp unwound from the roll body R (the starting end for winding onto the core member Rc) has not yet passed the actuator 71a.

[0041] The cut paper detection unit 72 can detect whether or not a cut paper Kp is stored in the cut paper storage section 11b of the feeding tray 1. More specifically, it detects whether a cut paper Kp is stored in the cut paper storage section 11b by detecting the cut paper Kp placed on the support plate 17. The cut paper detection unit 72 is attached to the arm 2a. As shown in Figure 5(a), the cut paper detection unit 72 includes an actuator 72a and a sensor 72b. The actuator 72a is supported by the arm 2a so as to be rotatable about a rotation axis 72a2. The axial direction of the rotation axis 72a2 is parallel to the left-right direction. The sensor 72b is a sensor that detects the actuator 72a. The sensor 72b is attached to the arm 2a. The sensor 72b is, for example, a photosensor having a light-emitting element and a light-receiving element (not shown).

[0042] When the cut paper Kp is not stored in the cut paper storage section 11b, as shown in Figure 5(a), a portion of the actuator 72a enters the through hole 17b. At this time, the actuator 72a does not obstruct the optical path of the sensor 72b and is not detected by the sensor 72b. When the cut paper Kp is stored in the cut paper storage section 11b, as shown in Figure 5(b), the aforementioned portion of the actuator 72a cannot enter the through hole 17b, and the aforementioned portion contacts the upper surface of the cut paper Kp stacked on the support plate 17. At this time, the optical path of the sensor 72b is obstructed, and the actuator 72a is detected by the sensor 72b. As a result, the cut paper detection unit 72 can detect whether or not the cut paper Kp is stored in the cut paper storage section 11b. In Figure 5, the first paper presence / absence detection unit 73 and the second paper presence / absence detection unit 74 are not shown.

[0043] The first paper presence detection unit 73 and the second paper presence detection unit 74 (the "detection unit" of the present invention) are attached to the arm 2a, separated to the left and right so as to sandwich the roller 2. The first paper presence detection unit 73 detects whether or not paper P is positioned in a position where it can be fed by the feed roller 2. Furthermore, the first paper presence detection unit 73 and the second paper presence detection unit 74 detect the positions of the arm 2a and the roller 2 when printing on roll paper Rp.

[0044] The functions and operations of the first paper presence detection unit 73 and the second paper presence detection unit 74 will be described below. First, the process when printing on cut paper Kp will be explained with reference to Figure 6. In this case, only the first paper presence detection unit 73 is used, so the illustration and explanation of the second paper presence detection unit 74 will be omitted. As shown in Figure 6, the first paper presence detection unit 73 includes an actuator 73a (the "first actuator" of the present invention) and a sensor 73b (the "first sensor" of the present invention). The actuator 73a is supported on the arm 2a so as to be rotatable about a rotation axis 73a2. The axial direction of the rotation axis 73a2 is parallel to the left-right direction. The sensor 73b is a sensor that detects the actuator 73a. The sensor 73b is attached to the arm 2a. The sensor 73b is, for example, a photosensor having a light-emitting element and a light-receiving element (not shown). The output signal of the sensor 73b changes according to the displacement of the actuator 73a that occurs when the arm 2a changes its posture.

[0045] The actuator 73a is biased clockwise in Figure 6 by its own weight. When no cut paper Kp is stored in the cut paper storage section 11b, a part of the actuator 73a (the lower right corner in Figure 6) enters the gap G provided between the protrusion 18a and the support plate 17, as shown in Figure 6(a). At this time, another part of the actuator 73a (the left end in Figure 6) does not obstruct the optical path of the sensor 73b (sensor OFF state).

[0046] When at least one sheet of cut paper Kp is stored in the cut paper storage section 11b, as shown in Figure 6(b), the upper surface of the cut paper Kp comes into contact with the feed roller 2, allowing the feed roller 2 to feed the cut paper Kp. At this time, a part of the actuator 73a (the lower right corner in Figure 6) cannot enter the gap G, and another part of the actuator 73a (the left end in Figure 6) blocks the optical path of the sensor 73b (sensor ON state). As a result, the first paper presence detection unit 73 can detect that the cut paper Kp is positioned in a location where the feed roller 2 can feed the paper P.

[0047] Next, the process of printing on roll paper Rp will be explained with reference to Figures 7 to 10. As described above, the back tension mechanism 13 always applies a constant pressure to the roll paper Rp sandwiched between the upper roller 13a and the lower roller 13b. Therefore, after a while, when the leading edge of the roll paper Rp fed to the feed roller 2 reaches the intermediate roller pair 31, a constant tension is applied to the roll paper Rp between the transport section 30 (specifically the intermediate roller pair 31) and the back tension mechanism 13. As a result, as shown in Figure 7(a), the feed roller 2 and arm 2a, which contact the upper surface of the roll paper Rp upstream of the cutting section 4 and the intermediate roller pair 31 in the transport path, are lifted by the roll paper Rp together with the support plate 17 (not shown). At this time, the actuator 73a of the first paper presence detection section 73, whose posture is defined by the tensioned roll paper Rp, does not obstruct the optical path of the sensor 73b (sensor OFF state).

[0048] Here, the details of the second paper presence detection unit 74 will be described. As shown in Figure 7(b), the second paper presence detection unit 74 includes an actuator 74a (the "second actuator" of the present invention) and a sensor 74b (the "second sensor" of the present invention). The actuator 74a is supported on the arm 2a so as to be rotatable about a rotation axis 74a2. The position of the actuator 74a is on the opposite side from the actuator 73a, with the feed roller 2 and arm 2a in between. The axial direction of the rotation axis 74a2 is parallel to the left-right direction. The sensor 74b is a sensor that detects the actuator 74a. The sensor 74b is attached to the arm 2a. The sensor 74b is, for example, a photosensor having a light-emitting element and a light-receiving element (not shown). In this embodiment, the actuator 74a is positioned in a location that does not correspond to the gap G provided between the protrusion 18a and the support plate 17. The output signal of the sensor 74b changes according to the displacement of the actuator 74a that occurs when the arm 2a changes its posture.

[0049] When printing on roll paper Rp, as described above, the roll paper Rp, which is subjected to a constant tension, lifts the feed roller 2 and arm 2a together with the support plate 17. At this time, as shown in Figure 7(b), the actuator 74a of the second paper presence detection unit 74, whose orientation is determined by the tensioned roll paper Rp, does not obstruct the optical path of the sensor 74b (sensor OFF state).

[0050] Next, we will explain the case where the cutting unit 4 cuts the roll paper Rp during the printing operation on the roll paper Rp. In this case, if the cutting is successful, that is, if the roll paper Rp is completely separated front and back at the cutting point, the tension of the roll paper Rp is released, and the feed roller 2 and arm 2a swing downward together with the support plate 17 due to their own weight and return to substantially the same position as shown in Figure 1. On the other hand, if the cutting fails, they do not return to that position. When cutting fails, the position of the feed roller 2 and arm 2a will differ depending on the proportion of the roll paper Rp that has been cut in the width direction (left and right direction). For example, if the cutting percentage is close to 0%, the tension of the roll paper Rp is maintained and the position of the feed roller 2 and arm 2a does not change from the position shown in Figures 7(a) and (b). As the cutting percentage increases, the tension of the roll paper Rp decreases, and the feed roller 2 and arm 2a are displaced downward accordingly.

[0051] As an example, let's explain the case where the cutting ratio is 50%. In this case, as shown in Figures 8(a) and (b), the feed roller 2 and arm 2a are lower than the positions shown in Figures 7(a) and (b). The actuator 73a of the first paper presence detection unit 73, whose posture is determined by the tensioned roll paper Rp, blocks the optical path of the sensor 73b (sensor ON state), while the actuator 74a of the second paper presence detection unit 74 does not block the optical path of the sensor 74b (sensor OFF state). Therefore, the output signal of the sensor 73b changes from OFF to ON when the first posture is adopted while the arm 2a is changing from the position shown in Figure 7(a) to the position shown in Figure 8(a).

[0052] When the cutting is successful (100% cutting), the tension on the roll paper Rp is released, and the feed roller 2 and arm 2a swing downward together with the support plate 17 due to their own weight, displacing to the positions shown in Figures 9(a) and (b). This position is substantially the same as the position shown in Figure 1. At this time, since the roll paper Rp is blocking the upper opening of the gap G, a part of the actuator 73a cannot enter the gap G. Furthermore, the actuator 73a of the first paper presence detection unit 73 blocks the optical path of the sensor 73b (sensor ON state), and the actuator 74a of the second paper presence detection unit 74 also blocks the optical path of the sensor 74b (sensor ON state). Therefore, the output signal of the sensor 74b changes from OFF to ON when the arm 2a takes on the second posture while changing from the position shown in Figure 8(b) to the position shown in Figure 9(b). Note that the states shown in Figures 9(a) and (b) also represent the state before new printing begins on the roll paper Rp located upstream of the cutting point.

[0053] Figures 10(a) and 10(b) show the state when the roll paper Rp is removed from the state shown in Figures 9(a) and 9(b). At this time, since the roll paper Rp that was blocking the upper opening of the gap is gone, a part of the actuator 73a enters the gap. The actuator 74a of the second paper presence detection unit 74 is positioned in a location that does not correspond to the gap, so it does not displace even when the roll paper Rp is removed. Therefore, the actuator 73a of the first paper presence detection unit 73 does not obstruct the optical path of the sensor 73b (sensor OFF state), while the actuator 74a of the second paper presence detection unit 74 obstructs the optical path of the sensor 74b (sensor ON state).

[0054] Thus, in this embodiment, the positions of the arm 2a and the feed roller 2 can be detected based on the combination of output signals from the two sensors 73b and 74b after the roll paper Rp has been cut.

[0055] (Printing operation on roll paper Rp) Next, the printing operation on roll paper Rp in the printer 100 of this embodiment will be described with reference to Figure 11. The process described below is started when the control unit 10 receives a print command and is executed by the control unit 10. In the following description, it is assumed that the printer 100 is serial and that the head 5 is supported by a carriage (not shown) that moves back and forth from left to right.

[0056] In step S1, the control unit 10, having received a print command for the roll paper Rp, checks if the roll detection unit 71 indicates the presence of paper P, the cut paper detection unit 72 indicates the absence of cut paper Kp, and both the sensor outputs of the first paper presence detection unit 73 and the second paper presence detection unit 74 are ON. In this case, the control unit 10 rotates the feed roller 2 to begin transporting the roll paper Rp. After the roll paper Rp reaches the intermediate roller pair 31, the feed roller 2 and arm 2a are lifted by the roll paper Rp together with the support plate 17, resulting in the state shown in Figures 7(a) and (b). At this time, both the sensor outputs of the first paper presence detection unit 73 and the second paper presence detection unit 74 are OFF. The control unit 10 continues to transport the roll paper Rp until the leading edge of the roll paper Rp reaches the desired position below the head 5, at which point ink is ejected from the head 5. This forms an image on the roll paper Rp.

[0057] In step S2, it is determined whether the length of the roll paper Rp along the transport path from the leading edge of the roll paper Rp to the cutting section 4 has reached the desired length based on the print command. This determination may be made using the cumulative amount of the amount of the roll paper Rp transported from the leading edge by the PF roller pair 32 and the distance between the PF roller pair 32 and the cutting section 4 stored in the control unit 10. If the above condition is met (S3: YES), the roll paper Rp is in the cutting position, so in step S3, the rotating blade 4b of the cutting section 4 is moved left and right to cut the roll paper Rp.

[0058] In step S4, the control unit 10 determines that the disconnection was successful (S4:YES) if the sensor outputs of both the first paper presence detection unit 73 and the second paper presence detection unit 74 change from OFF (Figure 7) to ON (Figure 9), and proceeds to step S5.

[0059] In step S5, the control unit 10 determines whether the ink ejection from the head 5 based on the print command has finished at this point. If it has finished (S5: YES), the control unit 10 controls the feed roller pair 33 to eject the roll paper Rp from the output tray 6. On the other hand, if the ink ejection has not finished (S5: NO), the process proceeds to step S7.

[0060] In step S7, the control unit 10 performs a correction to reduce the amount of paper P transported per conveyance by the intermediate roller pair 31 during intermittent transport. If the standard amount of paper transported per conveyance was X0, then after the correction in step S7, the amount of paper transported per conveyance becomes X0-M1 (where M1 is a positive value). The reason for reducing the amount of paper transported per conveyance when the roll paper Rp is successfully cut is that the load on the intermediate roller pair 31 decreases due to the successful cutting, and the amount of slip during transport decreases accordingly.

[0061] In step S8, printing continues until ink ejection from the head 5 based on the print command is completed, using the transport volume corrected in step S7. Then, the process moves to step S6, and the roll paper Rp is ejected from the output tray 6.

[0062] If it is determined that the cutting was not successful in step S4 (S4:NO), the process proceeds to step S9. The case where it is determined that the cutting was not successful includes both cases where the sensor outputs of the first paper presence detection unit 73 and the second paper presence detection unit 74 remain OFF (for example, the cutting rate is 0%) and cases where the sensor output of the first paper presence detection unit 73 is ON and the sensor output of the second paper presence detection unit 74 is OFF (for example, the cutting rate is 50% and the roll paper Rp is partially cut).

[0063] In step S9, the control unit 10 determines whether the ink ejection from the head 5 based on the print command has finished at this point. If it has finished (S9: YES), the control unit 10 controls the ejection roller pair 33 to eject the roll paper Rp from the paper output tray 6. Then, in step S11, the control unit 10 has the notification unit 8 issue a notification prompting the user to cut the roll paper Rp themselves, as cutting the roll paper Rp has failed. On the other hand, if the ink ejection has not finished (S9: NO), the process proceeds to step S12.

[0064] In step S12, the control unit 10 stops printing on the roll paper Rp. That is, it stops the ejection of ink from the head 5 and the transport of the roll paper Rp. Furthermore, the control unit 10 has the notification unit 8 notify the user that the cutting failed and prompt the user to input whether or not they wish to continue printing.

[0065] If, in step S13, a user indicates to the operation unit or terminal that they do not wish to continue printing (S13: NO), the process proceeds to step S10. On the other hand, if a user indicates to the operation unit or terminal that they wish to continue printing (S13: YES), the process proceeds to step S14.

[0066] In step S14, the control unit 10 determines whether the roll paper Rp has been partially cut (for example, if the cutting rate is 50%). If the sensor output of the first paper presence detection unit 73 is ON and the sensor output of the second paper presence detection unit 74 is OFF, it determines that the roll paper Rp has been partially cut (S14: YES) and proceeds to step S15. Printing continues until the ink ejection from the head 5 based on the print command is completed. Then, the process moves to step S10 and the roll paper Rp is ejected from the output tray 6.

[0067] In step S15, the control unit 10 performs a correction to reduce the amount of material transported per conveyance by the intermediate roller pair 31. If the standard amount of material transported per conveyance was X0, then after the correction in step S15, the amount of material transported per conveyance becomes X0-M2 (where M2 is a positive value smaller than M1). The reason why the correction amount is made smaller than the correction amount M1 in step S7 is that when the roll paper Rp is partially cut, the load on the intermediate roller pair 31 is greater than when the cutting of the roll paper Rp is successful, and accordingly the reduction in the amount of slip during transport becomes smaller.

[0068] Once the correction process is complete in step S15, the process proceeds to step S16. At this point, printing continues until the ink ejection from the head 5 based on the print command is complete, based on the transport volume after the correction in step S15. Then, the process moves to step S10, where the roll paper Rp is ejected from the output tray 6.

[0069] (Effects of the embodiment) According to the embodiment described above, if the cutting unit 4 successfully cuts the roll paper Rp, the tension of the roll paper Rp decreases, causing the feed roller 2 and arm 2a to be displaced downward. However, if the cutting is unsuccessful, the amount of displacement of the feed roller 2 and arm 2a will be smaller than in the case of success. Therefore, the success or failure of cutting the roll paper Rp can be confirmed based on the positions of the feed roller 2 and arm 2a detected by the first paper presence detection unit 73 and the second paper presence detection unit 74.

[0070] In the printer 100 according to this embodiment, tension can be applied to the roll paper Rp between the roll body R and the intermediate roller pair 31 even without the back tension mechanism 13. However, in that case, the amount of tension depends on the remaining amount of roll body R, and as the remaining amount decreases, the feed roller 2 and arm 2a are also displaced downward accordingly. In contrast, in this embodiment, the back tension mechanism 13 applies tension to the roll paper Rp, so that the feed roller 2 and arm 2a can always be positioned in the same place before cutting the roll paper Rp, regardless of the remaining amount of roll body R. Therefore, the difference in the amount of displacement of the feed roller 2 and arm 2a between successful and unsuccessful cutting of the roll paper Rp can be increased. This improves the accuracy of determining the success or failure of cutting the roll paper Rp.

[0071] Furthermore, in this embodiment, the feeding unit 20, which includes the arm 2a that serves as the roller support, functions as a displacement member. Therefore, in cases where a feeding roller 2 and arm 2a are required for the device configuration, it becomes unnecessary to provide a separate displacement member in addition to the feeding unit 20. As a result, the device configuration can be simplified.

[0072] Furthermore, in this embodiment, an actuator 73a is rotatably attached to an arm 2a that is supported so as to be able to swing around a pivot shaft 2b. The output signal of the sensor 73b changes in accordance with the displacement of the actuator 73a caused by the change in the posture of the arm 2a. With such a relatively simple configuration, it is possible to confirm whether or not the roll paper Rp has been cut.

[0073] Furthermore, in this embodiment, since two detection units, a first paper presence detection unit 73 and a second paper presence detection unit 74, it is possible to detect not only when the roll paper Rp is completely cut, but also when it is partially cut. In this way, in this embodiment, the success or failure of the cut can be confirmed with higher accuracy.

[0074] In addition, in this embodiment, the amount of paper transported per transport by the intermediate roller pair 31 is corrected so that the lower the displacement members, namely the feed roller 2 and arm 2a, are after the cutting operation of the roll paper Rp, the smaller the transport amount per transport. This makes it possible to adjust the actual transport amount to correspond to the decrease in the amount of slip of the roll paper Rp at the intermediate roller pair 31 following the successful cutting of the roll paper Rp. Therefore, image quality degradation can be suppressed. Note that when the "first position" of the feed roller 2 and arm 2a in this invention is the position shown in Figure 9, the "second position" is the position shown in Figure 7 or Figure 8, and when the "first position" of the feed roller 2 and arm 2a in this invention is the position shown in Figure 8, the "second position" is the position shown in Figure 7.

[0075] Furthermore, in this embodiment, printing is stopped if the roll paper Rp is not successfully cut, thus preventing the formation of unnecessary images that the user may not want.

[0076] (modified version) Although preferred embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and various design modifications are possible as described in the claims, as shown below.

[0077] In the embodiment described above, the roll paper unwound from the roll body R is used as a long sheet-like medium, but other materials may be fed. In the embodiment described above, the displacement member is the feeding section 20, but the displacement member may be provided as a separate component from the feeding section 20. Furthermore, the feeding mechanism of the present invention does not have to have a back tension mechanism. In that case, the rotational resistance of the roll body will provide tension to the roll paper Rp. Therefore, as the remaining amount of roll paper Rp in the roll body decreases, the tension applied to the roll paper Rp decreases, and the feeding roller 2 and arm 2a gradually lower even though no cutting operation is being performed.

[0078] In the above-described embodiment, the cutting unit 4 is located upstream of the transport roller pair (intermediate roller pair 31) in the transport path, but it may also be located downstream. Furthermore, in the above-described embodiment, the cutting unit has a fixed blade and a rotating blade, but the configuration of the cutting unit in the present invention is not limited to this. Furthermore, in the above-described embodiment, the detection unit has two paper presence / absence detection units, but there may be one or three or more paper presence / absence detection units.

[0079] The printer 100 according to the above embodiment can selectively form images on both roll paper Rp and cut paper Kp. However, the image forming apparatus according to the present invention may not be able to form images on cut paper Kp (a sheet-like medium shorter than a long sheet-like medium), that is, it may only be able to form images on roll paper Rp. In that case, the support plate 17 may be omitted. The roll detection unit 71 and cut paper detection unit 72 described in the above embodiment may also be omitted.

[0080] In the embodiment described above, printing to the roll paper Rp is stopped in step S12, but printing may be continued or the paper may be ejected without stopping. Which to do depends on the user settings at that time. Also, the printing operation described with reference to Figure 11 is based on the assumption that the printer 100 is serial type, but in the case of a line type, instead of correcting to reduce the amount of paper transported per transport in steps S7 and S15, a correction to reduce the transport speed may be performed. Note that in the case of either serial or line type printers 100, it is not necessary to perform the above-mentioned correction to reduce the amount of paper transported or the transport speed.

[0081] In this embodiment, printing is stopped if the roll paper Rp is not successfully cut. However, printing may be continued until completion, and the notification unit 8 may be instructed to prompt the user to cut the ejected roll paper Rp at the desired position. Furthermore, in the above-described embodiment, after stopping the printing operation in step S12, the user confirmation may be omitted and the paper may be forcibly ejected (S10).

[0082] In the present invention, the image forming unit may be a laser engine that uses toner as a colorant, in addition to an inkjet head that ejects ink. The present invention is not limited to printers and can be applied to facsimile machines, copiers, multifunction devices, etc. Furthermore, the feeding mechanism of the present invention can be applied to image forming apparatuses other than those having an image forming unit. [Explanation of symbols]

[0083] 1 Feeding tray 2 Feeding rollers 2a Arm (roller support) 4 Cut section 4a fixed blade 4b Rotary blade 5. Head (image forming unit) 73. First paper presence / absence detection unit (detection unit) 74. Second paper presence / absence detection unit (detection unit) 8 Hochi Department 10 Control Unit 11a Roll storage section (storage section) 11b Cut paper storage section 13. Back tension mechanism 17 Support plate 20 Feeding section (displacement member) 30 Conveying section 31 Intermediate roller pair (conveyor roller pair) 32 PF Laura vs 33 Discharge roller pair 71 Roll detection unit 72 Cut paper detection unit 73a Actuator (First Actuator) 73b Sensor (First Sensor) 74a Actuator (Second Actuator) 74b Sensor (Second Sensor) 100 Printers 100a enclosure

Claims

1. A storage section capable of accommodating long sheet-like media, A pair of conveying rollers that conveys the sheet-like medium supplied from the storage unit along a conveying path, A cutting section for cutting a sheet-like medium conveyed by the aforementioned pair of conveying rollers, Upstream of the transport path from the cutting section and the transport roller pair, a displacement member contacts the upper surface of the sheet-like medium, and when the cutting section successfully cuts the sheet-like medium, the displacement member displaces downward as the tension applied to the sheet-like medium decreases. A feeding mechanism comprising a detection unit for detecting the position of the displacement member.

2. Upstream of the conveying path from the cutting section and the conveying roller pair, the system further includes a back tension mechanism that applies tension to the sheet-like medium. The feeding mechanism according to claim 1, wherein the displacement member contacts the upper surface of a sheet-like medium to which tension is applied by the back tension mechanism.

3. The feeding mechanism according to claim 1 or 2, wherein the displacement member includes a roller support that rotatably supports a feeding roller for feeding a sheet-like medium toward the cutting section and the pair of conveying rollers.

4. The roller support includes an arm that is supported so as to be able to swing around a pivot point, The feeding mechanism according to claim 3, wherein the detection unit includes a first rotating member rotatably attached to the arm, and a first sensor whose output signal changes in accordance with the displacement of the first rotating member caused by a change in the posture of the arm.

5. A storage section capable of accommodating long sheet-like media, A pair of conveying rollers that conveys the sheet-like medium supplied from the storage unit along a conveying path, A cutting section for cutting a sheet-like medium conveyed by the aforementioned pair of conveying rollers, A displacement member that contacts the upper surface of the sheet-like medium upstream of the cutting section and the transport roller pair in the transport path, and displaces downward as the tension applied to the sheet-like medium decreases, The system includes a detection unit that detects the position of the displacement member, The displacement member includes a roller support that rotatably supports a feeding roller that feeds a sheet-like medium toward the cutting section and the pair of conveying rollers, The roller support includes an arm that is supported so as to be able to swing around a pivot point, The detection unit is a feeding mechanism that includes a first rotating member rotatably attached to the arm, and a first sensor whose output signal changes in accordance with the displacement of the first rotating member caused by a change in the posture of the arm.

6. The detection unit further includes a second rotating member rotatably attached to the arm, and a second sensor whose output signal changes in accordance with the displacement of the second rotating member caused by a change in the arm's posture. The output signal of the first sensor changes when the arm assumes a first posture. The feeding mechanism according to claim 4 or 5, wherein the output signal of the second sensor changes when the arm takes a second posture different from the first posture.

7. A feeding mechanism according to any one of claims 1 to 6, An image forming apparatus comprising an image forming unit that forms an image on a sheet-like medium downstream of the transport roller pair in the transport path.

8. After the cutting operation of the sheet-like medium by the cutting section, when the displacement member is in the first position, the load on the transport roller pair is smaller than when the displacement member is in the second position which is above the first position. It also has a control unit, The image forming apparatus according to claim 7, wherein, after the cutting operation, when the displacement member detected by the detection unit is in the first position, the amount or speed of transport by the transport roller pair is reduced compared to when the displacement member is in the second position.

9. It also has a control unit, The image forming apparatus according to claim 7, wherein the control unit stops image recording by the image forming unit if there is no change in the output signal from the detection unit after the cutting operation of the sheet-like medium by the cutting unit.

Images