Drum-type transfer mechanism and image forming apparatus

Abstract

To provide a drum-type transfer mechanism capable of independently performing an operation to stop rotations of a drum-shaped member in the case of emergency stop in addition to supply of an inverse voltage to a drive motor of the drum-type transfer mechanism.SOLUTION: A drum-type transfer mechanism comprises first power supply means for supplying an operation voltage to a drive motor which is a rotary drive source of a drum-shaped member; a driven roller which is rotated while following rotations of the drum-shaped member; second power supply means for supplying an operation voltage to rotation suppression means which suppresses the rotations of the driven roller; and power source supply switch means which switches a supply state of the operation voltage from each of the first power supply means and the second power supply means.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a drum-type transport mechanism and an image forming system. [Background technology]

[0002] In an image forming apparatus that forms an image on a sheet-like medium, a drum-type transport mechanism that is configured to transport the medium along a drum-shaped member is known. An image forming apparatus that includes a drum-type transport mechanism may be equipped with an emergency stop button for immediately stopping the rotation of the drum-shaped member in the event of an emergency. The drum stop mechanism that includes the emergency stop button is configured to cut off the supply of power to a drive source (such as a motor) that supplies rotational power to the drum-shaped member when it detects an operation (pressing) of the emergency stop button.

[0003] For example, a technology has been disclosed in which, in order to stop a drive motor during an emergency stop operation, the charge stored in a capacitor is reversed in polarity, a reverse voltage is applied to the motor itself, and a force is applied to rotate the motor in the opposite direction, thereby stopping the motor (see, for example, Patent Document 1). Summary of the Invention [Problem to be solved by the invention]

[0004] When the technology disclosed in Patent Document 1 is applied to a drive motor that serves as the driving source for a drum transport mechanism, the larger the drive motor used to rotate a large drum-shaped member, the more likely it is that the remaining charge in the capacitor will run out before the motor stops rotating.

[0005] That is, there is a problem with stopping the drum-shaped member by applying a reverse voltage to the drive motor as in the conventional technology.

[0006] An object of the present invention is to provide a drum-type transport mechanism that is equipped with a drum stopping mechanism that, in addition to supplying a reverse voltage to the drive motor of the drum-type transport mechanism, independently stops the rotation of the drum-shaped member in the event of an emergency stop. [Means for solving the problem]

[0007] In order to solve the above problems, one aspect of the present invention relates to a drum-type transport mechanism that transports sheet-like media along the outer peripheral surface of a drum-shaped member, and is characterized in comprising a first power supply means that supplies an operating voltage to a drive motor that serves as a rotational drive source for the drum-shaped member, a driven roller that rotates in response to the rotation of the drum-shaped member, and a second power supply means that supplies an operating voltage to a rotation suppression means that suppresses rotation of the driven roller, and a power supply switching means that switches the supply state of the operating voltage from each of the first power supply means and the second power supply means. Effect of the Invention

[0008] According to the present invention, in addition to supplying a reverse voltage to the drive motor of the drum-type transport mechanism, an operation of stopping the rotation of the drum-shaped member in the event of an emergency stop can be independently performed. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic diagram of an inkjet recording apparatus as an example of an image forming apparatus. [Diagram 2] FIG. 2 is a configuration diagram illustrating an embodiment of a drum-type transport mechanism according to the present invention. [Diagram 3] FIG. 13 is a diagram showing a comparative example of a control block for controlling the operation of the drum-type transport mechanism. [Figure 4] FIG. 4 is a control block diagram for controlling the operation of the drum-type transport mechanism according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A drum-type transport mechanism and an image forming apparatus according to an embodiment of the present invention will be described below with reference to the drawings. First, the embodiment of the image forming apparatus will be described with reference to FIG.

[0011] [Embodiment of Image Forming Apparatus] Fig. 1 is a schematic diagram of an inkjet recording apparatus 1, which is an example of an image forming apparatus. As shown in Fig. 1, the inkjet recording apparatus 1 includes an input section 10, an image forming section 20, a drying section 30, and a discharging section 40. The inkjet recording apparatus 1 forms an image by causing the image forming section 20 to eject ink onto paper P, which is an example of a sheet-like medium, that is input from the input section 10. Then, the inkjet recording apparatus 1 dries the ink attached on the paper P in the drying section 30, and then discharges the paper P to the discharging section 40.

[0012] Additionally, an upstream transport path Ph1 and a downstream transport path Ph2 are formed inside the inkjet recording apparatus 1. The upstream transport path Ph1 and the downstream transport path Ph2 refer to spaces through which the paper P passes inside the inkjet recording apparatus 1. The upstream transport path Ph1 is a transport path upstream of the image forming unit 20 in the transport direction of the paper P (i.e., from the loading unit 10 to the image forming unit 20). The downstream transport path Ph2 is a transport path downstream of the image forming unit 20 in the transport direction of the paper P (i.e., from the image forming unit 20 to the discharge unit 40 via the drying unit 30).

[0013] The transport direction of the paper P is the direction from the entrance unit 10 through the image forming unit 20 and the drying unit 30 to the discharge unit 40 along the upstream transport path Ph1 and downstream transport path Ph2 when the paper P is captured with the transport drum 101 as a drum-shaped member at its center. The upstream transport path Ph1 and downstream transport path Ph2 may extend linearly or curved in the transport direction of the paper P, or may be configured by a combination of these.

[0014] The carry-in section 10 includes an input tray 11 on which a plurality of sheets P are stacked, a feeding device 12 that separates and sends out the sheets P one by one from the input tray 11, and a pair of registration rollers 13 that sends the sheets P through an upstream transport path Ph1 to the image forming section 20. The feeding device 12 can be any known feeding device having a feeding function, such as a device using rollers or a device using air suction.

[0015] The paper P sent from the input tray 11 to the upstream transport path Ph1 by the feeding device 12 has its leading edge reaching the pair of registration rollers 13, and then the pair of registration rollers 13 is driven at a predetermined timing to be conveyed into the image forming unit 20. In this embodiment, the configuration of the input unit 10 is not particularly limited as long as it has a function of sending out the paper P to the image forming unit 20.

[0016] The image forming section 20 forms an image on the paper P carried in by the carry-in section 10, and discharges the paper P on which the image has been formed to the drying section 30. The image forming section 20 includes a sheet transport device 21 that transports the paper P, a liquid discharge section 22 that discharges liquid onto the paper P transported by the sheet transport device 21, and an upstream cylinder 102 and a downstream cylinder 103 as driven rollers arranged upstream of a transport drum 101. A mechanism including the upstream cylinder 102 and the downstream cylinder 103 arranged opposite the transport drum 101 at the center corresponds to a drum-type media transport mechanism.

[0017] The sheet conveying device 21 includes a conveying drum 101 that rotates while supporting the paper P on its peripheral surface, and a suction device 52 that is a suction means that generates a suction force on the peripheral surface of the conveying drum 101. The upstream cylinder 102 receives the paper P from the carry-in section 10 and passes it to the conveying drum 101. The downstream cylinder 103 receives the paper P on which an image has been formed from the conveying drum 101 and passes it to the drying section 30.

[0018] The paper P transported from the carry-in unit 10 to the image forming unit 20 has its leading edge gripped by a gripper provided on the surface of the upstream cylinder 102, and is transported as the surface of the upstream cylinder 102 moves. The paper P transported by the upstream cylinder 102 is delivered to the transport drum 101 at a position opposite to the transport drum 101.

[0019] Grippers are also provided on the surface of the transport drum 101, and the leading edge of the paper P is gripped by the grippers. In addition, a plurality of suction holes are formed and dispersed on the surface of the transport drum 101. A suction device 52 generates a suction airflow toward the inside of the transport drum 101 at each suction hole. The paper P is adsorbed to the surface of the transport drum 101 by this suction airflow. The paper P delivered from the upstream cylinder 102 to the transport drum 101 has its leading edge gripped by the grippers, and is adsorbed to the surface of the transport drum 101 by the suction airflow, and is transported as the surface of the transport drum 101 moves.

[0020] The liquid discharge section 22 includes discharge units 23 (23A to 23F) which are liquid discharge means. For example, the discharge unit 23A discharges cyan (C) liquid, the discharge unit 23B discharges magenta (M) liquid, the discharge unit 23C discharges yellow (Y) liquid, and the discharge unit 23D discharges black (K) liquid. The discharge units 23E and 23F are used to discharge any of YMCK, or special liquids such as white and gold (silver). Furthermore, a discharge unit that discharges a treatment liquid such as a surface coating liquid can also be provided.

[0021] The ejection units 23A to 23F are, for example, full-line heads in which a plurality of liquid ejection units (hereinafter simply referred to as "heads") having a nozzle row in which a plurality of nozzles are arranged are arranged on a base member. The ejection operations of the ejection units 23A to 23F are controlled by a drive signal corresponding to image data. When the paper P transported by the transport drum 101 passes through an area facing the liquid ejection section 22, each color ink is ejected from the nozzles provided on the lower surface (nozzle surface) of each ejection unit 23A to 23F. As a result, an image corresponding to the image data is formed on the paper P.

[0022] In this embodiment, the image forming unit 20 only needs to have a function of depositing liquid onto the paper P to form an image, and the configuration for ejecting or depositing the liquid is not particularly limited.

[0023] The paper P transported by the transport drum 101 (in other words, the paper P on which an image has been formed by the image forming unit 20) is delivered to the downstream cylinder 103 at a position facing the transport drum 101. More specifically, the paper P has its leading edge gripped by a gripper provided on the surface of the downstream cylinder 103, and is transported as the surface of the downstream cylinder 103 moves. At this time, the surface of the paper P on which the image has been formed (the inner peripheral surface of the paper P transported along the curved transport path) faces the downstream cylinder 103. The paper P transported by the downstream cylinder 103 is delivered to the drying unit 30 through the downstream transport path Ph2.

[0024] As described above, the transport path for the paper P, the upstream transport path Ph1 and the downstream transport path Ph2, are formed linearly in the transport direction, and the portion along the outer peripheral surface of the transport drum 101 is a curved transport path that is curved in the transport direction.

[0025] An emergency stop switch 109 that allows the rotation of the conveyor drum 101 to be stopped at any time is disposed on the outer surface of the housing including the image forming unit 20. As illustrated in Fig. 1, the emergency stop switch 109 is provided at a position that is easy for the user to operate. The emergency stop switch 109 may also be provided at multiple locations.

[0026] The drying section 30 includes a drying mechanism section 31 and a suction transport mechanism section 32. The drying mechanism section 31 dries the ink attached to the paper P in the image forming section 20. The suction transport mechanism section 32 transports the paper P delivered from the downstream cylinder 103 to the discharge section 40 along the downstream transport path Ph2. That is, the paper P delivered from the image forming section 20 through the downstream cylinder 103 is received by the suction transport mechanism section 32, and then transported by the suction transport mechanism section 32 to pass through the drying mechanism section 31 and delivered to the discharge section 40. When passing through the drying mechanism section 31, the ink on the paper P is subjected to a drying process, and liquid components such as water in the ink evaporate, the ink is fixed on the paper P, and curling of the paper P is suppressed.

[0027] The discharge section 40 includes a discharge tray 41 on which a plurality of sheets of paper P are stacked. The sheets of paper P transported from the drying section 30 by the suction transport mechanism 32 are sequentially stacked and held on the discharge tray 41. In this embodiment, the discharge section 40 only needs to have a function of discharging the sheets of paper P, and the configuration of the discharge section 40 is not particularly limited.

[0028] The inkjet recording apparatus 1 of the present embodiment is composed of an input unit 10, an image forming unit 20, a drying unit 30, and a discharging unit 40, but other functional units may be added as appropriate. For example, the inkjet recording apparatus 1 may be provided with a pre-processing unit between the input unit 10 and the image forming unit 20 that performs pre-processing of the image formation, or a post-processing unit between the drying unit 30 and the discharging unit 40 that performs post-processing of the image formation.

[0029] An example of the pre-processing section is a section that performs a processing liquid application process in which processing liquid that reacts with the ink to suppress bleeding is applied to the paper P. However, the content of the pre-processing is not limited to the above-mentioned example. An example of the post-processing section is a paper inversion and transport process in which the paper P on which an image has been formed in the image forming section 20 is inverted and sent back to the image forming section 20 to form images on both sides of the paper P, or a process of binding multiple sheets of paper P on which images have been formed. However, the content of the post-processing is not limited to the above-mentioned example.

[0030] In this embodiment, the inkjet recording device 1 is described as an example of an image forming device. However, the image forming device is not limited to one that visualizes meaningful images such as characters and figures by the discharged droplets as long as it is equipped with a droplet discharge unit that discharges liquid toward the surface of the sheet material to be dried. As another example, the image forming device may be one that forms a pattern or the like that has no meaning in itself.

[0031] The medium is not limited to a specific material, and may be any material to which the liquid can be attached even temporarily, such as paper, thread, fiber, cloth, leather, metal, plastic, glass, wood, or ceramics. The medium may be, for example, a film product, a cloth product for clothing, a building material such as wallpaper or flooring, or a leather product. In this embodiment, the medium is referred to as a "medium" that can be attached to the liquid even temporarily. In addition, a specific example of the "droplet" is not limited to the ink ejected from the liquid ejection unit 22, and may be a processing liquid used in a pre-processing unit. In other words, the present invention can be widely applied to a droplet ejection device that causes droplets to land at a target position.

[0032] Moreover, the term "ejection head" refers to a functional component that ejects or sprays liquid from an ejection hole (nozzle). As an energy generation source for ejecting liquid, ejection energy generation means such as a piezoelectric actuator, a thermal actuator using an electrothermal conversion element such as a heating resistor, and an electrostatic actuator consisting of a vibration plate and a counter electrode can be used. However, the ejection energy generation means used is not limited to the above examples.

[0033] [Embodiment of drum-type conveying mechanism] Next, an embodiment of a drum-type transport mechanism according to the present invention will be described with reference to the drawings. Fig. 2 is a schematic diagram of a medium transport unit 100 as a drum-type transport mechanism. As shown in Fig. 2, the medium transport unit 100 includes a transport drum 101, an upstream cylinder 102 disposed at a position opposite the transport drum 101 and the upstream transport path Ph1, and a downstream cylinder 103 disposed at a position opposite the transport drum 101 and the downstream transport path Ph2.

[0034] The transport drum 101 has a gripping means for gripping the leading edge in the transport direction of the paper P transported from the upstream side, on the outer periphery, and transports the gripped paper P by rotating the transport drum 101.

[0035] The upstream cylinder 102 and the downstream cylinder 103 are both provided to rotate in synchronization with the rotation of the conveying drum 101. For example, a driven gear provided to mesh with a drive gear provided on the rotation shaft of the conveying drum 101 is fixed to each of the rotation shafts of the upstream cylinder 102 and the downstream cylinder 103. Although not shown in FIG. 2, the conveying drum 101 rotates by driving a power motor serving as a rotation drive source, so that when the conveying drum 101 rotates, the drive gear rotates, and the driven gear rotates accordingly, thereby rotating the upstream cylinder 102 and the downstream cylinder 103. In other words, the upstream cylinder 102 and the downstream cylinder 103 correspond to driven rollers that rotate in synchronization with the rotation of the conveying drum 101, which corresponds to a drive roller.

[0036] The upstream cylinder 102 and downstream cylinder 103, which rotate in synchronization with the conveying drum 101 as a driving roller, stop in synchronization with the conveying drum 101 when the rotation of the conveying drum 101 stops. On the other hand, when the conveying drum 101 rotates by inertia in a state where the driving force is lost, the rotation of the conveying drum 101 can be stopped by stopping the rotation of the upstream cylinder 102 and downstream cylinder 103. In other words, the upstream cylinder 102 and downstream cylinder 103 also operate as a brake mechanism that suppresses the rotation of the conveying drum 101.

[0037] [Comparative Example for the Embodiment of the Drive Control Block of the Conveyor Drum 101] Next, a description will be given of a control block that controls the rotational drive of the transport drum 101. The transport drum 101 is configured to be rotated by a drum drive motor 108 that rotates when an operating voltage is applied from a power source 104.

[0038] Before describing the embodiments of the present invention in detail, a conventionally known example of a drive control block will be described as a comparative example with reference to Fig. 3. As shown in Fig. 3, an AC voltage is supplied from a power source 104 as an AC power source to a drum drive motor 108 as a drive source that supplies a rotational drive force to a transport drum 101 via a motor driver 106. Note that the drum drive motor 108 is not limited to an AC motor, and may be any motor that can control the rotation of the transport drum 101 in response to control from a control circuit 107 described later.

[0039] The motor driver 106 is configured to control the operation of a drum drive motor 108 based on a control signal from a control circuit 107 .

[0040] The control circuit 107 executes a control program to output a control signal to the motor driver 106 so as to realize a predetermined control process. The control circuit 107 also outputs an appropriate control signal in relation to the operating status of the motor driver 106.

[0041] An electromagnetic contactor 105 is disposed between the motor driver 106 and the power source 104. That is, the supply state of the operating voltage from the power source 104 to the drum drive motor 108 is switched by the electromagnetic contactor 105.

[0042] The electromagnetic contactor 105 as a power supply switching means includes an a-contact switch 111 as a switching means for switching between supplying and cutting off the operating voltage from the drive power source 104 to the motor driver 106. The a-contact switch 111 is in a "closed state" when the coil 110 included in the electromagnetic contactor 105 is in an excited state, and is in an "open state" when the coil 110 is in a partially excited state.

[0043] The excitation of coil 110 provided in electromagnetic contactor 105 is configured to be switched depending on the state of emergency stop switch 109. Operational input (pressing) to emergency stop switch 109 is regarded as an "external input", and when there is no external input, coil 110 is in an excited state. When there is an external input via emergency stop switch 109, coil 110 is in a partially excited state. In other words, the excitation state of coil 110 is switched depending on the operation of emergency stop switch 109.

[0044] When the emergency stop switch 109 is not pressed (normally), the coil 110 in the electromagnetic contactor 105 is in an excited state, and therefore the a-contact switch 111 in the electromagnetic contactor 105 is in a "closed state." At this time, the voltage from the power source 104 is supplied to the motor driver 106, so that the drum drive motor 108 rotates and the conveyor drum 101 rotates. In other words, when the emergency stop switch 109 is not pressed, the operating voltage from the power source 104 as a first power source means is supplied to the drum drive motor 108 in a supply state (first state).

[0045] The following describes problems that may occur in the control block having the above configuration. For example, if an abnormality occurs in the control software running in the control circuit 107, and the control signal from the control circuit 107 to the motor driver 106 becomes unstable (for example, unintended continuous driving), the drum drive motor 108 cannot be controlled.

[0046] In this case, assume that in the conventional configuration illustrated in Fig. 3, a user presses the emergency stop switch 109 to stop the rotation of the transport drum 101. In this case, the coil 110 in the electromagnetic contactor 105 is de-energized, so that the a-contact switch 111 is opened and the voltage supply from the power source 104 to the drum drive motor 108 is cut off. As a result, the drum drive motor 108 loses its driving force, and the transport drum 101 loses the driving force for rotation, so that the rotation speed of the transport drum 101 slows down over time and eventually stops.

[0047] However, since the rotation of the transport drum 101 has inertia, it is difficult to immediately stop the rotation immediately after the emergency stop switch 109 is pressed, and the rotation may continue for a certain period of time.

[0048] Even if the emergency stop switch 109 is pressed to cut off the drive voltage, the residual charge stored in the capacitor of the motor driver 106 may be supplied to the drum drive motor 108, causing it to continue rotating. If this happens, the rotation of the conveyor drum 101 may continue for a short time even if the emergency stop switch 109 is pressed. In other words, in the conventional configuration, the conveyor drum 101 may not be stopped immediately even if the emergency stop switch 109 is pressed, and may continue to rotate a short distance.

[0049] [Embodiment of the drive control block of the transport drum 101] As described above, in the conventional configuration, even if the emergency stop switch 109 is pressed, the transport drum 101 continues to rotate slightly before it stops rotating, making it difficult to stop it immediately. The drive control block of the transport drum 101 according to this embodiment has a configuration that suppresses the continued rotation that occurs after the rotation stop operation, as in the conventional comparative example, and can stop the transport drum 101 immediately when the emergency stop switch 109 is operated.

[0050] Fig. 4 is an example of a drive control block according to this embodiment. As shown in Fig. 4, it has a part of the same configuration as the conventional comparative example, so the differences will be mainly described. The drive control block according to this embodiment is not affected by the presence or absence of power interruption due to the operation (external input) of the emergency stop switch 109, and has a second power source 113 as a second power source means different from the drive power source 104 as a first power source means.

[0051] The second power supply 113 is, for example, a switching power supply, and converts the AC voltage from the power supply 104 into a DC voltage of, for example, 24 V and supplies the converted voltage. The second power supply 113 is disposed between the power supply 104 and the electromagnetic contactor 105, and is configured to convert the input from the power supply 104 and output it to the electromagnetic contactor 105.

[0052] The output voltage of the second power source 113 is configured to be input to a b-contact switch 115 in the electromagnetic contactor 105. The operating voltage from the second power source 113 is configured to be applied via the b-contact switch 115 to a first cylinder brake 116 and a second cylinder brake 117 as rotation suppression means independently mounted on the upstream cylinder 102 and the downstream cylinder 103, which rotate in synchronization with the conveying drum 101, respectively.

[0053] The electromagnetic contactor 105 provided in the drive control block according to this embodiment includes a contact switch 111 and a contact switch 115 .

[0054] The first cylinder brake 116 and the second cylinder brake 117 are operated by a voltage supply (e.g., DC 24 V) from the second power source 113, and have a configuration similar to that of a powder brake, for example. Therefore, when DC 24 V is applied to the first cylinder brake 116 and the second cylinder brake 117, the electromagnetic coils provided in the first cylinder brake 116 and the second cylinder brake 117 generate a magnetic field and solidify the magnetic material. In other words, when a predetermined voltage is supplied to the first cylinder brake 116 and the second cylinder brake 117, the upstream cylinder 102 and the downstream cylinder 103 transition to a state in which rotation is inhibited.

[0055] During normal operation (normal state) when the emergency stop switch 109 is not pressed, the coil 110 in the electromagnetic contactor 105 is in an excited state, and therefore the a-contact switch 111 in the electromagnetic contactor 105 is in a "closed state." In this state, voltage from the driving power source 104 is supplied to the motor driver 106 and the drum drive motor 108. Also, when the emergency stop switch 109 is not pressed and the coil 110 in the electromagnetic contactor 105 is in an excited state, the b-contact switch 115 is in an "open state." In this state, voltage from the second power source 113 is not supplied to the first cylinder brake 116 and the second cylinder brake 117.

[0056] When the emergency stop switch 109 is pressed and the coil 110 in the electromagnetic contactor 105 is de-energized, the a-contact switch 111 in the electromagnetic contactor 105 is opened and the b-contact switch 115 is closed. As a result, the power supply from the power source 104 to the drum drive motor 108 is cut off, and the drum drive motor 108 transitions to a stopped state.

[0057] Then, electric power from the second power source 113 is supplied to the first cylinder brake 116 and the second cylinder brake 117, thereby preventing the upstream cylinder 102 and the downstream cylinder 103 from rotating.

[0058] That is, when the emergency stop switch 109 is pressed, a non-supply state (second state) is established in which the operating voltage from the drive power source 104 serving as a first power source means is not supplied to the drum drive motor 108. At the same time, a supply state is established in which the operating voltage from the second power source 113 serving as a second power source means is supplied to the first cylinder brake 116 and the second cylinder brake 117.

[0059] When the first cylinder brake 116 and the second cylinder brake 117 are supplied with an operating voltage and operate, the upstream cylinder 102 and the downstream cylinder 103 stop rotating. As already described, the upstream cylinder 102 and the downstream cylinder 103 are configured to mechanically synchronize their rotation with the conveying drum 101, so when the rotation of the upstream cylinder 102 and the downstream cylinder 103 stops due to the operation of the first cylinder brake 116 and the second cylinder brake 117, the rotation of the conveying drum 101 is mechanically restricted. As a result, the conveying drum 101 can be stopped mechanically without requiring a control to stop the rotation of the conveying drum 101.

[0060] By restricting the rotation of the upstream cylinder 102 and the downstream cylinder 103, the conveying drum 101 that has lost its driving source can be stopped immediately.

[0061] In addition, the second power supply is not limited to a DC power supply, but may be any power supply used to operate the rotation suppression means for stopping the rotation of the upstream cylinder 102 and the downstream cylinder 103, as described above.

[0062] Furthermore, the rotation suppression means is not limited to the first cylinder brake 116 and the second cylinder brake 117, but may be any means that exerts a suppression force to stop the rotation of the conveying drum 101 when the operating voltage to the conveying drum 101 is cut off.

[0063] At least one of the first cylinder brake 116 and the second cylinder brake 117 is sufficient.

[0064] As described above, according to the drum-type transport mechanism of this embodiment, if an operational abnormality occurs in the control software running in the control circuit 107 and the control signal from the control circuit 107 to the motor driver 106 becomes unstable, the user can press the emergency stop switch 109 to immediately stop the transport drum 101.

[0065] The present invention is not limited to the above-described embodiments, and various modifications are possible without departing from the technical gist of the present invention. The present invention covers all technical matters included in the technical ideas described in the claims. The above-described embodiments are preferred examples, but a person skilled in the art can realize various modifications from the disclosed contents. Such modifications are also included in the technical scope described in the claims.

[0066] For example, aspects of the present invention are as follows. <1> A drum-type conveying mechanism that conveys a sheet-like medium along an outer peripheral surface of a drum-shaped member, a first power supply means for supplying an operating voltage to a drive motor which serves as a rotation drive source for the drum-shaped member; a driven roller that rotates in response to the rotation of the drum-shaped member; a second power supply means for supplying an operating voltage to a rotation suppressing means for suppressing rotation of the driven roller; a power supply switching means for switching a supply state of an operating voltage from each of the first power supply means and the second power supply means; The drum-type conveying mechanism is characterized by comprising: <2> The power supply switching means is in a first state in which an operating voltage is supplied from the first power supply means to the drive motor, an operating voltage is not supplied from the second power supply means to the rotation suppressing means, In a second state, which is a non-supply state in which the operating voltage from the first power supply means to the drive motor is cut off, an operating voltage is supplied to the rotation suppressing means from the second power supply means. The above <1> 2 is a drum-type conveying mechanism according to the first embodiment. <3> The power supply switching means switches the supply state from the first state to the second state in response to an external input. The above <2> 2 is a drum-type conveying mechanism according to the first embodiment. <4> the power supply switching means is an A-contact switch having an input side connected to the first power supply means and an output side connected to the drive motor, the A-contact switch being closed in the first state and being open in the second state; a b-contact switch having an input side connected to the second power supply means and an output side connected to the rotation suppressing means, the b-contact switch being open in a first state and closed in a second state; a coil that controls opening and closing operations of the a-contact switch and the b-contact switch in response to the external input; Equipped with switching an excitation state of the coil in response to the external input, thereby switching a supply state of an operating voltage from the first power supply means and the second power supply means; The above <3> 2 is a drum-type conveying mechanism according to the first embodiment. <5> the first power supply means being an AC power supply; The second power supply means is a DC power supply that converts a voltage from the AC power supply into a DC voltage. The above <1> or the above <4> 13. The drum-type transport mechanism according to claim 12, <6> The rotation suppressing means is disposed on the upstream side and the downstream side of the drum-shaped member in the transport direction of the medium. The above <1> or the above <5> 13. The drum-type transport mechanism according to claim 12, <7> an image forming unit that forms an image on a sheet-like medium; a conveying unit that conveys the medium to the image forming unit; Equipped with The conveying unit is <1> or the above <6> The drum-type conveying mechanism according to any one of claims 1 to 4 is provided. The image forming apparatus is characterized in that: [Explanation of symbols]

[0067] 1: Inkjet recording device 10: Loading area 20: Image forming section 21: Sheet conveying device 100: Media transport section 101: Transport drum 102: Upstream cylinder 103: Downstream cylinder 104: Power source 105:Magnetic contactor 106: Motor driver 107: Control circuit 108: Drum drive motor 109: Emergency stop switch 110: Coil 111: a-contact switch 113:Second power supply 115: B-contact switch 116: First cylinder brake 117: Second cylinder brake [Prior art documents] [Patent documents]

[0068] [Patent Document 1] Japanese Patent Publication No. 60-114471

Claims

1. A drum-type conveying mechanism that conveys a sheet-like medium along an outer peripheral surface of a drum-shaped member, a first power supply means for supplying an operating voltage to a drive motor which serves as a rotation drive source for the drum-shaped member; a driven roller that rotates in response to the rotation of the drum-shaped member; a second power supply means for supplying an operating voltage to a rotation suppressing means for suppressing rotation of the driven roller; a power supply switching means for switching a supply state of an operating voltage from each of the first power supply means and the second power supply means; A drum-type conveying mechanism comprising:

2. The power supply switching means is In a first state in which an operating voltage is supplied from the first power supply means to the drive motor, an operating voltage is not supplied from the second power supply means to the rotation suppressing means, In a second state, which is a non-supply state in which the operating voltage from the first power supply means to the drive motor is cut off, an operating voltage is supplied to the rotation suppressing means from the second power supply means.

2. The drum type transport mechanism according to claim 1.

3. The power supply switching means switches the supply state from the first state to the second state in response to an external input.

3. The drum type transport mechanism according to claim 2.

4. the power supply switching means is an A-contact switch having an input side connected to the first power supply means and an output side connected to the drive motor, the A-contact switch being closed in the first state and being open in the second state; a b-contact switch having an input side connected to the second power supply means and an output side connected to the rotation suppressing means, the b-contact switch being open in a first state and closed in a second state; a coil that controls opening and closing operations of the a-contact switch and the b-contact switch in response to the external input; Equipped with switching an excitation state of the coil in response to the external input, thereby switching a supply state of an operating voltage from the first power supply means and the second power supply means; 4. The drum type transport mechanism according to claim 3.

5. the first power supply means being an AC power supply; The second power supply means is a DC power supply that converts a voltage from the AC power supply into a DC voltage.

5. The drum type transport mechanism according to claim 1.

6. The rotation suppressing means is disposed on the upstream side and the downstream side of the drum-shaped member in the transport direction of the medium.

5. The drum type transport mechanism according to claim 1.

7. an image forming unit that forms an image on a sheet-like medium; a conveying unit that conveys the medium to the image forming unit; Equipped with The conveying unit includes the drum-type conveying mechanism according to claim 1.

1. An image forming apparatus comprising:

Images