JPH04345438A - Recording device - Google Patents

Abstract

PURPOSE:To remove a sheet of recording paper easily when a feeding trouble such as meandering is generated, by conveying sheets of recording paper between a paper feed roller and a press roller provided with a magnet in at least one of them to attract each other. CONSTITUTION:A paper feed roller 7 is constructed with a magnetic tube 20 made of iron material covered with an elastic rubber layer on the periphery, and a 1st and a 2nd press roller 8,9 are provided with a permanent magnet 32 on the periphery of a shaft 31, and guided with a guide portion 33 to contact to the roller 7 by an attractive force. Thereby the pressing force of the roller 8 is reduced as the roller is separated from the roller 7. When a sheet of recording paper 6 is stopped in the feeding channel between the roller 7 and the rollers 8,9, the pressing force to the paper 6 can be reduced by separating the press roller 8 from the roller 7. Thereby such troubles that the recording paper 6 is pinched firmly or hardly removed can be prevented.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus that conveys recording paper and forms an image.

0002

2. Description of the Related Art In conventional recording apparatuses, a drive source such as a motor rotates a roller for conveying the recording paper, and a pressure roller that is in pressure contact with this roller generates frictional force to convey the recording paper. I was letting it happen. This pressure contact of the pressure roller was performed by a spring. (For example,
2-99356)

0003

However, in an apparatus equipped with a pressing roller using a spring as described above, it is not easy to recover from the occurrence of recording paper conveyance failure.

[0004] In other words, recording paper conveyance defects often occur due to
Accompanied by meandering of the recording paper and wrinkles of the recording paper. When recording paper meandering occurs, the recording paper that has been deflected in a specific direction loses its place and bends due to the regulating means in the paper width direction. When such a situation occurs, since the recording paper is pressed between the paper feed roller and the pressure roller, it is forced into a narrow area and becomes difficult to remove. If the condition worsens, the recording paper may tear and removal becomes particularly difficult.

The present invention aims to solve this problem, and it is an object of the present invention to provide a recording apparatus in which the recording paper can be easily removed from the roller contact portion of the paper conveyance section in the event of recording paper conveyance failure. .

[0006]

[Means for Solving the Problems] The recording device of the present invention includes a paper feed roller that conveys a recording medium by rotating, and a rotatably supported support that contacts the paper feed roller with the recording medium interposed. At least one of the paper feed roller and the pressure roller includes a magnet, and the two are configured to be attracted to each other by magnetic attraction force.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing the structure of an inkjet recording apparatus according to an embodiment of the present invention. The inkjet head 1 scans over the recording paper 6 while being guided by a guide shaft 4 and a guide plate 5. Scanning is performed by a scanning mechanism 2 driven by an inkjet head scanning motor 3. The recording paper 6 is wound around a paper feed roller 7 and is pressed by a first pressure roller 8 and a second pressure roller 9. The recording paper 6 is subjected to frictional force due to the above-mentioned pressing force, and is conveyed in the direction of B by the rotation of the paper conveyance roller 7 as indicated by A. The paper feed roller 7 is driven by a roller drive motor 12. A first sensor 10 and a second sensor 11 are provided to monitor the operation of the paper transport section, and detect the presence or absence of recording paper. That is, the presence or absence of recording paper is detected based on the difference in light reflectance depending on the presence or absence of recording paper, and an electrical signal is output.

[0009] The paper feed roller 7 is constructed by covering a magnetic tube 20 made of iron with an elastic layer 21 made of rubber.

The first and second pressing rollers 8 and 9 are equipped with a permanent magnet 32 around a shaft 31, as shown in more detail in the figure.
It is guided by a guide portion 33, is rotatable and movable toward the paper feed roller 7, and is always in contact with the paper feed roller 7 under suction force. The permanent magnet 32 is magnetized so that its magnetization axis coincides with the direction of the axis 31.

The inkjet head 1 has a plurality of nozzles arranged in the paper feeding direction, and selectively discharges ink to form an image while scanning the recording paper 6 in the width direction.

Next, the operation will be explained.

By manual feeding, the recording paper is fed into the abutment area between the paper feed roller 7 and the first pressure roller 8 and is put on standby. A paper conveyance operation is performed as shown in FIG. 2 in synchronization with the printing operation. That is, the paper feed roller 7 rotates in response to the "recording paper supply signal", and after a predetermined time, the first sensor 10,
The leading edge of the recording paper 6 reaches the second sensor 11 . Further, after a predetermined period of time, the rear end of the recording paper 6 passes through the first sensor 10 and the second sensor 11. Accordingly, the output of the sensor changes sequentially such as "no paper", "paper present", and "no paper". The control unit of the recording apparatus monitors these conditions, and if a normal change in output is not detected after a predetermined period of time has elapsed, it determines that there is a paper conveyance failure and stops the operation.

According to the configuration of the pressing roller 7 of this embodiment, recovery processing can be easily performed when a paper feeding failure occurs. This will be explained using FIG. 3. In the figure, paper feed roller 7,
The distance between the axes of the pressing roller 8 that comes into contact with this is defined as x, and the change in pressing force due to x is shown. With the configuration of the prior art, the pressing force when the pressing roller 8 is pressed by the spring 41 increases with x as shown by the broken line C. On the other hand, in the configuration of this embodiment, as the pressure roller 8 moves away from the paper feed roller, the leakage magnetic flux from the permanent magnet 32 decreases, so that it decreases with x as shown by the solid line D in the figure. Therefore, if the recording paper 6 becomes jammed in the path during conveyance, the pressing force decreases as the recording paper 6 moves away from the pressure roller 8. Therefore, there is no possibility that the recording paper will be tightly pinched or that it will be difficult to remove it. Further, when the pressure roller is pushed by springs at both ends of the shaft, it is not possible to move a large distance, but in the configuration of this embodiment, the pressure roller 8 is movably guided by the guide section 33, and the paper feed roller 7 The range of movement of the distance between the axes can be widened. Therefore, even if the recording paper is bent significantly, the pressing roller 8 will not move back significantly and press the recording paper. Also, the operation of removing the recording paper can be easily performed. Furthermore, it also has the advantage that it is easy to assemble since there is no need to attach springs or the like. A second embodiment is shown in FIG. In this figure, only the configuration of the pressure roller 8 is shown. Axis 3
1, a disk-shaped permanent magnet 32 and a yoke plate 42 made of a magnetic material are laminated and integrated. It has high magnetic efficiency and can effectively utilize the energy of the magnet, making it possible to obtain a strong pressing force. The operation and other operations are the same as those in the previous embodiment, and the explanation will be omitted.

A third embodiment is shown in FIG. Press roller 8
Only the configuration is shown. A cylindrical permanent magnet 3 is placed around the shaft 31.
It is constructed by integrating 2. By using a rubber magnet as the permanent magnet, it is possible to increase the contact nip and increase the contact area between the recording paper and the paper feed roller, thereby achieving stable paper feed performance.

A fourth embodiment is shown in FIGS. 6 and 7. axis 71
and a plate-shaped permanent magnet 75 are integrated. A low-friction plastic bush 72 and a plastic pipe 73 are integrated to support the shaft 71. The magnetization direction of the permanent magnet 75 coincides with the plate thickness direction indicated by E. Permanent magnet 7
The magnetic flux from the magnetic poles 5 generates an attractive force with the paper feed roller 7, and presses the pipe 73 through the plastic bush 72. The pipe 73 rotates at the same speed as the paper feed roller 7, and the permanent magnet 75 and shaft 71 do not rotate. The outer peripheral surface of the plastic bush 72 slides on the shaft 71. The permanent magnet 75 is always stationary with its magnetic pole face facing the paper feed roller 7. A sixth embodiment is shown in FIG. This figure shows the case of a wire dot printer, in which the head 1 scans in the thickness direction of the paper surface and records on the recording paper 6. The recording paper 6 is supported by a platen 81 and is conveyed in the direction of arrow F by first and second paper feed rollers 82 and 83 and first and second pressure rollers 84 and 85, which are driven by a drive source (not shown). Ru. The first and second paper feed rollers 82 and 83 are made by disposing an elastic body with a high coefficient of friction around a metal shaft, and generate a paper feed force due to the high frictional force. As the first and second pressure rollers 84 and 85, pressure rollers having the configurations shown in the first to fifth embodiments can be used. During the paper jam recovery operation, the first and second pressure rollers 84, 8
Even when the pressure rollers 84 and 85 are moved back a lot, the pressure rollers 84 and 85
In the configuration of this embodiment, since the pressure roller moves to the contact position by the action of gravity, the movable range of the pressure roller can be set to be large. Also, unlike the configuration in which both ends of the pressing shaft are pressed by a spring, the pressing roller itself does not need to have high bending rigidity. Therefore, a pressure roller with a small diameter can be used, and the pressure rollers 84 and 85 can be provided close to the head 1. Therefore, it is possible to reduce the margin area of the recording paper and print close to the front and rear edges of the recording paper, thereby effectively utilizing the recording paper surface.

[0017]

[Effects of the Invention] In the recording device of the present invention, at least one of the pressing roller and the paper feed roller has a built-in magnet and a magnetic body, and the recording paper is pressed by the magnetic force between them. . For this reason, the suction force that acts between both rollers has the characteristic of decreasing with distance, so that the recording paper will not be tightly pinched when the paper feed malfunctions, and it is easy to remove the jammed recording paper. have an effect. In addition, since a suction force is generated directly between both rollers, there is no need to apply external force. Therefore, it is possible to use a pressure roller with a small diameter, and by arranging it close to the head, there is also the effect that printing can be performed with less blank space on the recording paper. Furthermore, it also has the advantage of being easy to assemble.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the configuration of a recording apparatus according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a paper feeding operation of the recording apparatus of the present invention.

FIG. 3 is a diagram showing the relationship between the paper feed roller, the pressure roller pressing force, and the distance between the rollers of the recording apparatus of the present invention.

FIG. 4 is a diagram showing the configuration of a pressure roller showing a second embodiment of the present invention.

FIG. 5 is a diagram showing the configuration of a pressure roller showing a third embodiment of the present invention.

FIG. 6 is a perspective view showing the configuration of a pressing roller according to a fourth embodiment of the present invention.

FIG. 7 is a perspective cross-sectional view showing the configuration of a pressing roller according to a fourth embodiment of the present invention.

FIG. 8 is a sectional view showing the configuration of a recording apparatus according to a fifth embodiment of the present invention.

[Explanation of symbols]

7, 82, 83 Paper feed roller 8, 9, 84
, 85 press roller 31, 71 shaft

Claims (1)

[Claims] 1. A paper feed roller that rotates to convey a recording medium, and a pressure roller that is rotatably supported and abuts on the paper feed roller with the recording medium interposed therebetween; A recording apparatus characterized in that at least one of the roller and the pressure roller includes a magnet, and the two are configured to be attracted to each other by magnetic attraction force.