JP2007031079A - Attracting force sensing device and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an attracting force sensing device capable of sensing the attracting force acting between a recording sheet of paper and a transport belt. <P>SOLUTION: The attracting force sensing device to sense the attracting force between the transport belt 12 and the recording sheet 70 transported thereon is composed of a torque management mechanism 1 installed at one end of a reversing shaft 22 to support a reversing roller 21 rotating in the regular and the reverse direction upon abutting to the recording sheet 70 and transmitting the driving force to the reversing shaft 22 and a rotation sensing mechanism 2 installed at the other end of the reversing shaft 22 and sensing the rotation in the regular and the reverse direction of the reversing roller 21 through the reversing shaft 22. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an adsorption force detection device that detects an adsorption force between a recording sheet conveyed on a conveyance belt and the conveyance belt, and an image forming apparatus including the adsorption force detection device.

  2. Description of the Related Art An image forming apparatus having a configuration in which a recording sheet is adsorbed and conveyed by a conveyance belt that is stretched between a driving roller and a driven roller is widely known. In a serial scan type image forming apparatus using various types of recording heads including an ink jet system, image recording is performed in the process in which recording paper is conveyed by a conveying belt. A conveying belt is also used as means for conveying the recording paper onto which the toner image has been transferred from the photoreceptor to the fixing device.

In the image forming apparatus using the conveyance belt as described above, when the adsorbing force between the recording paper and the conveyance belt is reduced, the recording paper is lifted from the conveyance belt and a jam occurs or a skew occurs. there were. There is also a problem in that the paper feed amount changes due to a decrease in the attractive force, which adversely affects the formed image.
An object of the present invention is to provide an adsorption force detection device capable of detecting an adsorption force between a recording paper and a conveyance belt.

In order to achieve the above object, an invention according to claim 1 is an adsorption force detection device for detecting an adsorption force between a conveyance belt and a recording sheet conveyed thereon, and is in contact with the recording sheet. Provided at one end of the reversing shaft that supports the reversing roller that rotates forward and reverse, and a torque management mechanism that transmits driving force to the reversing shaft, and provided at the other end of the reversing shaft, forward and reverse rotation of the reversing roller via the reversing shaft The most important feature is an attraction force detection device including a rotation detection mechanism for detecting the rotation.
According to a second aspect of the present invention, in the adsorption force detecting device according to the first aspect, the torque management mechanism has a torque limiter, and when the adsorption force is larger than the torque of the torque management mechanism, the reversing roller rotates forward, and the torque management The main feature of the reversing roller is that the reversing roller reversely rotates when the torque of the mechanism is larger than the attracting force.
According to a third aspect of the present invention, in the adsorption force detecting device according to the first aspect, the torque management mechanism includes a friction sheet, a friction plate that covers the friction sheet, and a friction spring that defines torque. Features the device.
According to a fourth aspect of the present invention, in the adsorption force detecting device according to the first aspect, the torque management mechanism includes a friction sheet and a leaf spring that fixes the friction sheet and applies pressure to the reversing shaft. Is the main feature.
According to a fifth aspect of the present invention, in the adsorption force detecting device according to the first aspect, the rotation detection mechanism mainly includes an adsorption force detecting device having a mechanical switch.
The invention according to claim 6 is characterized in that an image forming apparatus equipped with the suction force detecting device according to claim 1 is the main feature.

  The present invention is provided at one end of a reversing shaft that supports a reversing roller that rotates forward and backward in contact with recording paper, and a torque management mechanism that transmits driving force to the reversing shaft; Since an adsorption force detection device including a rotation detection mechanism that detects forward / reverse rotation of the reverse roller via the shaft is provided, the adsorption force between the recording paper and the conveyance belt can be detected.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1A and 1B are configuration diagrams centering on a conveyance belt portion of an image forming apparatus including an adsorption force detection device according to an embodiment of the present invention, wherein FIG. 1A is a top view, FIG. 1B is a front view, and FIG. ) Is a diagram showing the position of the rotation detection plate.
The transport belt portion is passed between the side plates 14 and 15 and is rotatably supported by the transport roller 10. The transport belt portion is disposed in parallel with the transport roller 10 and is rotatably supported by the side plates 14 and 15. Between the tension roller 11, the endless conveyor belt 12 spanned between the rollers 10, 11, the conveyor pulley 13 integrated with the shaft end of the conveyor roller 10, and between the conveyor pulley 13 and the drive pulley 24. A drive transmission belt 16 that is stretched over the belt, a reverse shaft 22 that supports the drive pulley 24 at one end and includes a reverse roller 21 in the middle, and a torque limiter disposed between the reverse shaft 22 and the drive pulley 24. 23, a rotation detection plate 30 fixed to the other end of the reversing shaft 22, an optical sensor 31 for detecting the rotation detection plate 30, a rotation stopper 32, and the like. To have. Reference numeral 1 denotes a torque management mechanism provided on the other end side of the reversing shaft 22, and reference numeral 2 denotes a rotation detection mechanism provided on one end side of the reversing shaft. The torque management mechanism 1 is provided at one end of a reversing shaft 22 that supports a reversing roller 21 that rotates forward and backward in contact with the recording paper surface, and transmits a driving force to the reversing shaft 22. The rotation detection mechanism 2 is a means that is provided at the other end of the reversing shaft 22 and detects forward / reverse rotation of the reversing roller 21 via the reversing shaft.
The torque management mechanism 1 and the rotation detection mechanism 2 constitute an adsorption force detection device.
The reversing roller 21 is configured to be rotatable in contact with the upper surface of the recording paper 70 on its peripheral surface, and the reversing roller 21 when the suction force between the conveying belt 12 and the recording paper 70 is stronger than the torque of the torque management mechanism 1. Rotates forward with the movement of the recording paper 70 (rotation = clockwise in FIG. 1B), and the reverse roller 21 rotates reversely when the torque of the torque management mechanism 1 is stronger than the attraction force. (Counterclockwise direction in FIG. 1B).
Further, the reversing shaft 22 that fixes the reversing roller 21 and the rotation detecting plate 30 that detects the rotation of the reversing shaft 21 rotate in synchronization, so that the forward / reverse rotation position of the rotation detecting plate 30 is fixed by the optical sensor 31 that is fixed. Detect and detect a decrease in adsorption power.
The conveyance roller 10, the tension roller 11, and the reverse shaft 22 are supported by the right side plate 14 and the left side plate 15 that are parallel to each other.
The torque management mechanism 1 includes a torque limiter 23, a drive pulley 24, and a reversing shaft 22 that rotatably supports the torque limiter 23 and the drive pulley 24. The torque limiter 23 is a mechanism that causes the drive pulley 24 to idle when a force greater than a predetermined torque is generated.

The rotation detection mechanism 2 of the first embodiment shown in FIG. 1 includes a rotation detection plate 30, an optical sensor 31, a rotation stopper 32, and a reverse shaft 22 that fixes the rotation detection plate 30. The optical sensor 31 is a reflective sensor that turns on and off when light is blocked and released as the rotation detection plate 30 rotates, and detects forward and reverse rotation of the reversing roller 21.
Drive transmission to the reversing shaft 22 is performed from the conveyance pulley 13 fixed to the conveyance roller 10 via the drive transmission belt 16 and the drive pulley 24. The reversing shaft 22 to which the drive is transmitted is configured to be able to rotate in the direction opposite to the conveyance direction of the recording paper 70, and the adsorption force between the conveyance belt 12 and the recording paper 70 is the specification value (torque of the torque management mechanism 1). In the case where the recording paper 70 is larger, the recording paper 70 is rotated in the clockwise direction. Further, when the specification value of the torque management mechanism 1 is higher than the suction force between the conveyance belt 12 and the recording paper 70, the reverse shaft 22 is configured to rotate in the reverse direction with respect to the conveyance direction of the recording paper 70.
As a result, the reversing shaft 22 is rotated forward and reverse by a change in the suction force between the conveying belt 12 and the recording paper 70, and detection when the suction force is reduced is enabled.

FIG. 2 is a top view showing a first embodiment of the torque management mechanism. The friction sheet 41, the friction plate 42 that fixes the friction sheet 41, the friction spring 43 that defines torque, the drive pulley 24 as a friction pulley that receives drive transmission via the friction element pulling 43, and the drive pulley 24 are supported. And a friction bracket 45.
The pressure of the friction spring 43 that defines the friction torque is finely adjusted by changing the distance between the friction bracket 45 and the drive pulley 24.
FIG. 3 is a block diagram showing a second embodiment of the torque management mechanism, where (a) is a top view and (b) is a front view. The friction sheet 41 includes a plate spring 50 that fixes the friction sheet 41 and generates a friction torque by the frictional force of the reversing shaft 22 and the friction sheet 41, and a plate spring bracket 51 that fixes the plate spring 50.
Since the pressure of the leaf spring 50 defining the friction torque can be easily changed and the structure is simple, the mechanism is inexpensive.
FIG. 4 is a configuration diagram of a rotation detection mechanism employing a mechanical switch. Although the rotation detection mechanism 2 of the first embodiment shown in FIG. 1 uses an optical sensor 31, the rotation detection mechanism 2 of the second embodiment includes a limit rotation detection plate 60 that rotates in conjunction with the reverse shaft 22, The rotation stopper 32 restricts the rotation of the limit rotation detection plate 60, and the mechanical switch 61 detects the position of the limit rotation detection plate 60.
By employing the mechanical switch 61, the detection accuracy can be increased.

1 is a configuration diagram centering on a conveyance belt portion of an image forming apparatus including an adsorption force detection device according to an embodiment of the present invention. FIG. It is a top view which shows the 1st Example of a torque management mechanism. It is a block diagram which shows the 2nd Example of a torque management mechanism. It is a block diagram of the rotation detection mechanism which employ | adopted the mechanical switch.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Torque management mechanism, 2 Rotation detection mechanism, 10 Conveyance roller, 11 Tension roller, 12 Conveyance belt, 13 Conveyance pulley, 14 Right side plate, 15 Left side plate, 16 Drive transmission belt, 21 Inversion roller, 22 Inversion shaft, 23 Torque limiter , 24 Drive pulley, 30 Rotation detection plate, 31 Optical sensor, 32 Rotation stopper, 41 Friction sheet, 42 Friction plate, 43 Friction spring, 44 Friction pulley, 45 Friction bracket, 50 Leaf spring, 51 Leaf spring bracket, 60 Limit rotation Detection plate, 61 Mechanical switch, 70 Recording paper

Claims (6)

  An adsorption force detection device for detecting an adsorption force between a conveyance belt and a recording paper conveyed thereon, provided on one end of a reversing shaft that supports a reversing roller that rotates forward and backward in contact with the recording paper surface, A torque management mechanism that transmits a driving force to the reversing shaft, and a rotation detection mechanism that is provided at the other end of the reversing shaft and detects forward / reverse rotation of the reversing roller via the reversing shaft. Adsorption power detection device.   2. The adsorption force detecting device according to claim 1, wherein the torque management mechanism includes a torque limiter, and when the adsorption force is larger than the torque of the torque management mechanism, the reverse roller rotates forward and the torque of the torque management mechanism is adsorbed. An adsorption force detecting device characterized in that the reversing roller reverses when the force is greater than the force.   2. The adsorption force detection device according to claim 1, wherein the torque management mechanism includes a friction sheet, a friction plate that covers the friction sheet, and a friction spring that defines torque. apparatus.   2. The adsorption force detection device according to claim 1, wherein the torque management mechanism includes a friction sheet and a leaf spring that fixes the friction sheet and applies pressure to the reversing shaft. .   2. The adsorption force detection device according to claim 1, wherein the rotation detection mechanism has a mechanical switch.   An image forming apparatus comprising the adsorption force detecting device according to claim 1.

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