JPS61192658A - Recording chart guiding device for copying machine - Google Patents

Abstract

PURPOSE:To prevent the tip of the one side end of a recording chart from floating up extremely, and also prevent the recording chart from being folded and shrinked restraining the printed image from being disturbed by arranging a recording chart guide means which is movable up and down, on the upper side of another side of a separation means located in the transfer path of a fixing device. CONSTITUTION:In order to prevent a recording chart from floating, an edge guide means 31 is arranged on the upper side of an entrance in the place B opposite to the side A where a separation/transfer means for the recording chart is located. This guide means 31 is located above a nip section N, when looked from the place, to which direction the recording chart is transferred, its oblique surface 31a is formed in such a way that the surface becomes lower in relation to be fixing roller 21 as the surface comes closer to the end of the fixing roller. When the recording chart is carried in where its side end A is regulated by the separation/transfer means, the other side end B tends to float up, but is forcively pressed down by the oblique surface 31a of the guide means 31 preventing the chart from being folded or shrinked while it is transferred. And the guide means furthermore prevents the upper surface of the recording chart, on which a toner printed image is transferred, from coming in contact with an insulating cover 23 arranged to the entrance of the fixing device 20 restraining the printed image from being disturbed.

Description

[Detailed description of the invention] [Industrial application field]

The present invention is described below! The present invention relates to a recording paper guide device in a copying machine such as an electrophotographic copying machine, in which the transport path for transporting paper to a fixing device has been improved.

[Conventional technology]

In an electrophotographic copying machine, a toner image formed on an image bearing member provided on the circumferential surface of a drum is transferred onto recording paper, and the transferred recording paper is separated from the circumferential surface of the drum by a separating means and then transported. The image is then conveyed to the fixing device, fixed, and then discharged outside the machine. The fixing device consists of a pair of upper and lower rollers: a fixing roller that has a built-in heater and is driven by a separately provided power source, and a pressure roller that comes into pressure contact with the fixing roller from below and rotates as a result. The fixing device is arranged so that its longitudinal direction (the tab) is parallel to the pressure contact portion formed by the pair of rollers of the fixing device with respect to the center. From the viewpoint of downsizing the copying machine body and simplifying the device, the recording paper is brought into close contact with the photosensitive drum and the toner image is transferred onto the recording paper, and then the recording paper is peeled off from the photosensitive drum. For example, a separation means using a separation belt may be provided only on one side with respect to the traveling direction of the object. For example, the separating means exemplified in JP-A-59-61862 corresponds to this, in which a separation belt energized is installed on one side of the circumferential surface of the photosensitive drum where the image is missing on the separation side. This separates the recording paper from the photosensitive drum. The recording paper separated from the photosensitive drum in this way is transported and carried into the above-mentioned fixing device, but in this process, the image formed by the unfixed toner electrostatically adhered to the recording paper is placed on the upper surface. The recording paper is conveyed by placing it on a rotating belt, or the recording paper is sucked through a gap between the rotating belts or a hole provided in the rotating belt, and the recording paper is attracted to the belt and conveyed. is taken. However, when using such a conveyance means, it is necessary to incorporate the above-mentioned device into the machine, and the device becomes complicated and the copying machine itself becomes large. Therefore, in a small and inexpensive copying machine, all belts and suction devices are removed, and a narrow floor-like width is installed on one side of the recording paper in the direction of travel, where the recording paper separation means is installed. A conveying means that pinches and conveys the recording paper with rollers is installed, and the recording paper is thereby conveyed. When the means for separating the recording paper from the photosensitive drum and the means for conveying it to the fixing device are installed only on one side in the direction of travel of the recording paper, the floating of the leading edge of the recording paper on the left and right with respect to the direction of travel of the recording paper may vary. An extreme difference will occur. That is, since the side where the conveying means is provided is regulated following the separating means, the leading edge of the recording paper tends to fall downward and travels closely on the conveying plate. On the other hand, the leading edge of the recording paper on the opposite side tends to float when it is peeled off from the photosensitive drum, and since the leading edge of the recording paper on the opposite side is further held down by the conveying means, this floating tendency is exacerbated. This float cannot be held down because there is no suction means such as suction. As you can see, the leading edge of the recording paper is extremely different depending on the left and right sides! If the recording paper enters the pair of fixing rollers under such circumstances, the tip of the pressed side of the recording paper will smoothly enter the nip of the pair of rollers of the fixing device, but the leading edge of the raised side of the recording paper will not reach a fixed pitch.
If it comes into contact with the top surface of the inlet of the device, the paper may fold or wrinkle, or the image may be distorted. Furthermore, while the recording paper is being conveyed from the separation means to the fixing device, there is a possibility that a portion of the recording paper may come into contact with a member installed above near the fixing device.

[Problems to be solved by the invention]

As described above, the present invention is a copying apparatus in which only one side of the recording paper is gripped using a separation belt, rollers, etc., separated from the photosensitive drum, conveyed, and carried into the fixing device. To provide a recording paper guide device in a copying machine which eliminates the problem caused by the leading edge of the recording paper being carried into a fixing device with only one side extremely lifted up, and allows simple and reliable conveyance of the recording paper. purpose.
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[Means to solve the problem]

The present invention aims to achieve the above object, and after an image is transferred from an image carrier to a recording paper by a transfer means, one end of the recording paper is separated from the image carrier by a separating means and arranged one above the other. A copying machine that conveys a recording paper to a fixing device comprising a pair of rollers, the copying machine further comprising a recording paper guiding means that is vertically movable at the upper stage of the other side of the separating means in the recording paper introduction path of the fixing device. This is achieved by a paper guiding device. [Embodiment] FIG. 1 shows a cross-sectional view of the main parts of an electrophotographic copying machine equipped with a recording paper guiding device of the present invention, and an overview of its functions will first be explained. The toner image formed on the photosensitive drum 11 rotating clockwise is transferred to a transfer electrode 12 onto a recording paper fed toward the circumferential surface of the photosensitive drum 11 by a registration roller.
Transcribed by. The recording paper with the toner image attached thereto is then urged by a spring 13 to the part of the separation side on the circumference of the photosensitive drum 11, and is separated from the photosensitive drum 11 by a tensioned separation belt 14. Further, the recording paper is sandwiched between a separation roller 15 and a separation roller 16 provided at the separation side edge, and conveyed to an ID 17, and then conveyed by a conveyance roller 18 and a conveyance roller 19 also provided at the separation side edge. It passes through the gap and reaches the fixing device 20. The conveying rollers 18 and the conveying rollers 219 can be adjusted to the extent that they are the same, and it is possible to reduce lifting of the opposite end surface in the case of recording paper having the maximum paper passing width. However, when such an adjustment is made, the lifting of the opposite end surface of recording paper having a narrower normal paper passing width is large. The fixing device 20 includes a fixing roller 21 that has a built-in heat source and rotates clockwise, and a pressure roller 2 that is in pressure contact with the fixing roller 21 and rotates as a result of the fixing roller 21.
The fixing roller 21 is surrounded by a heat insulating cover 23. The conveyed recording paper is carried in along the upper surface of the entrance guide plate 24 provided on the pressure roller 22 side, and is nipped and conveyed by the nip portion of the pair of rollers, and the toner image is fixed on the recording paper and fixed. It is discharged from the device 20. Here, if the leading edge of the recording paper is sufficiently pressed down, it will be easily guided to the nip N of the fixing device 20 along the entrance guide plate 24, but both the separating means and the conveying means are on the same side of the recording paper. 9, the leading edge of the recording paper on the opposite side is raised significantly when it is carried into the fixing device 20.
The portion of the recording paper on which the toner image is attached comes into contact with the lower surface of the heat insulating cover 23 above the entrance, causing image disturbance. The edge guide means 31 of the present invention is provided to prevent this, and its basic configuration is shown below. FIG. 2 shows the X-X view of FIG. 1 (view from the recording paper advancing direction), and is opposite to the side A where the recording paper separating and conveying means is located above the entrance of the fixing device 20. Edge guide means 31 for preventing the recording paper from lifting is provided on the B side of the recording paper. The edge guide means 31 is a plate material that is located above the nip portion N when viewed from the direction in which the recording paper is carried in, and has an inclined surface 31 that becomes lower as it approaches the roller end with respect to the axis of the fixing roller 21. The edge guide means 31 is a metal plate such as phosphor bronze or an elastic resin thin plate such as polycarbonate, and in this embodiment, it is attached to the heat insulating cover 23 above the entrance of the fixing device 20 so as to be perpendicular to the recording paper feeding direction. However, 9 out of 31 ms guides
It is also effective to install it with an inclination so that 31b is on the front side in the direction of travel. The slope 31a may be a cut surface, but if a thin plate is bent to form a slope with a small circular arc cross section, the slope 31a will have the effect of improving the slippage when it comes into contact with the end surface of the recording paper. When a recording paper is introduced into the recording paper guide device provided with such an edge guide means 31 with one end (A) regulated by the separating/conveying means, the other side (B) leading edge of the recording paper is introduced. tries to lift up, but this lifting of the tip is regulated by the slope 31a of the edge guide means 31, preventing the top surface of the recording paper on which the toner image is placed from coming into contact with the heat insulating cover 23 of the fixing device 20. , it also prevents the occurrence of image holes. Although the above configuration has been described in which the edge guide means Fi31 is simply fixed to the heat insulating cover 23 of the fixing device, an embodiment in which the edge guide means 31 is installed to be movable up and down will be described. Figure vJ3 shows a heat insulating cover 23 provided with a side plate 33 having a guide groove 32 for vertically guiding an edge guide means 311. A protruding pin 34 fixed to the edge guide means 311 is fitted into the groove 32. It is configured to move up and down. Third
In the embodiment shown in the figure, the bin 34 is installed with a screw means that can be released and fixed so that the slope 311a of the edge guide F9.311 is located in the entrance path at a position where the recording paper has an optimal entrance path 6. FIG. 4 shows an embodiment in which the edge guide means 311 of the embodiment in FIG. 3 has a structure that can be freely adjusted from the outside. A wire winding shaft 37 having one end fixed to the edge guide means 311 and extending in a direction opposite to the biasing direction of the spring 35 and provided on the heat insulating cover 23 via the support frame 23a.
Wrap it around. The wire winding shaft 37 is provided with a gear G1 via an inlet 38, and a ratchet wheel G for preventing reverse rotation is attached to the gear 62 that meshes with the gear 01. is fixed, and the pawl 39 is engaged with the ratchet grip G. Since the configuration is as described above, first, the edge guide means 3
11 to the lowest position with spring 35, and gear G2
By rotating clockwise, the engaged gear 61
is rotated counterclockwise, and the wire 36 is wound around the wire winding shaft 37, so that the edge guide means 311 rises against the spring 35 via the wire 36. Then, at the position where the passage of the recording paper has risen to the optimum position, Year 6
When the rotation of 2 is stopped, the ratchet pawl 39 moves to the ratchet position G.
, is engaged with and fixed. Therefore, the edge guide means 311 is placed in a position where the ear G2 is stopped. If it is necessary to lower the ratchet wheel G, then remove the ratchet pawl 39 and the spring will lower it. Although the edge guide means 311 is provided on the heat insulating cover 23 in this embodiment, it is of course possible to provide it on another separate member. Note that the optimal installation position for the edge guide means that prevents the recording paper from floating is the position that corresponds to the maximum paper passing width of the copying machine, but is generally located on the inner side and corresponds to the most commonly used paper passing width. It is more effective to set the In this way, the slope 311a is placed at a position corresponding to the normal paper passing width.
By installing the edge guide means 311 so that the edge guide means 311 has an appropriate height and inclination, there is generally no negative effect not only for recording paper of the normal paper passing width, but also for recording paper of the maximum paper passing width (the same effect is observed). [Effects of the Invention] According to the present invention, one end of the recording paper is separated from the photosensitive drum by a separating means, and a recording paper guide device, which is an edge guide means, is provided on a conveying path of the recording paper to be carried into a fixing device consisting of a pair of rollers. By providing the recording paper, folds and wrinkles that occur when the recording paper is conveyed are no longer caused, and image disturbances are no longer caused.

[Brief explanation of drawings]

FIG. 1 is a side sectional view showing the basic configuration of the present invention. FIG. 2 is the XX view. FIG. 3 is a perspective view showing an embodiment of the present invention. FIG. 4 is a perspective view showing another embodiment of the invention. 11... Photosensitive drum 12... Transfer electrode 14... Separation belt 17... Conveyance id 18... Conveyance roller 19...・
・・Conveyance roller 20 ・・Fixing device 21
...Fixing roller 22 ... Pressure roller
23... Heat insulation cover 24... Entrance guide plate 31, 311... Edge guide plate 32...
...Guide groove 33...Side plate 34...
... Pin 35 ... Spring 36 ... Wire 37 ... Wire winding shaft Applicant: Roku Konishi Photo Industry Co., Ltd. Figure 1, Figure 2, Figure 4. 2. 7′

Claims (2)

[Claims] (1) Copying in which, after an image is transferred from an image carrier to a recording paper by a transfer means, one end of the recording paper is separated from the image carrier by a separating means and conveyed to a fixing device consisting of a pair of rollers arranged above and below. What is claimed is: 1. A recording paper guide device for a copying machine, comprising a vertically movable recording paper guide means on the upper stage of the other side of the separation means in the recording paper introduction path of the fixing device. (2) A recording paper guide device in a copying machine according to claim 1, wherein the vertically movable recording paper guide means is moved up and down by a driving means.