JPS6312351Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a recording sheet guide device leading to a recording sheet leading edge positioning unit of an image recording apparatus, and particularly to a recording sheet leading edge positioning unit of an image recording apparatus that feeds paper from a plurality of paper feed trays. This invention relates to a recording sheet guide device.

In a conventional image recording device, for example, a copying device, alignment of the image position on the surface of an image carrier and the transfer material, which is a recording sheet, conveyed and supplied to the same surface is achieved by a pair of register rollers as transfer material conveyance means. It was customary to

That is, the transfer material is fed from a transfer material storage section such as a paper feed cassette to a pair of register rollers in a stationary state by a paper feeding means, its leading edge is regulated at the same position, and then at a certain timing, the transfer material is fed to a pair of register rollers in a stationary state. By rotating the transfer material, the transfer material is fed to the surface of the image carrier so that the feeding coincides with the image position. Here, in order to ensure that the image position on the surface of the image carrier and the position of the transfer material match, it is necessary to always regulate the transfer material at a fixed position of a pair of register rollers. However, in a copying apparatus having a plurality of transfer material storage sections, the transfer material fed from each of the transfer material storage sections reaches the register roller from different directions through each path.

Especially recently, with the increase in copy speed,
The capacity of the transfer material storage section has increased, and as image recording apparatuses have become smaller, the distance between the transfer material storage section and the register roller has become shorter. As a result, the transfer material fed from each transfer material storage section through each sheet conveyance path is now fed to the register rollers at a large angle with respect to the common tangent of the register rollers.
Then, the moving direction of the leading edge of the transfer material is changed by a guide member located at the boundary of each sheet conveyance path, and the leading edge of the transfer material is sent to the leading edge alignment section. In such a case, in order to accurately guide the leading edge of the transfer material to the leading edge alignment section,
It is necessary to provide the boundary guide member close to the tip alignment section. However, if a rigid guide member is provided close to the tip alignment section, there is a risk that it may come into contact with the register roller and damage it due to manufacturing errors. It was difficult.

In the case where the guide member is provided close to the roller, an elastic tongue-shaped guide is placed in the center of the recording sheet input side of the fixing roll and the pressure roll that is in pressure contact with the fixing roll. There is a fixing device that is designed to do this. but,
Since the tongue-shaped guide mentioned above guides only the center of the recording sheet, both ends of the recording sheet will droop under their own weight.
Since the leading edge of the recording sheet is curved, the leading edge of the transfer material cannot be accurately guided to the leading edge alignment section.

Therefore, it is difficult to regulate the leading edge of each transfer material conveyed to each sheet conveyance path at the same position.
There was a drawback that the image position shifted.

The present invention eliminates the above-mentioned conventional drawbacks, stabilizes the regulation of the leading edge position of the transfer material fed from multiple transfer material storage units, and stabilizes the image position during conveyance of recording sheets such as transfer materials. The present invention provides a guide device, and specifically, the gist of the present invention is to provide a guide device that includes a first sheet conveyance path and a second
A guide member is provided that is located at the boundary of the sheet conveyance path and guides the recording sheet conveyed through each sheet conveyance path, and a guide member is provided at an end portion of the guide member on the register roller side over substantially the entire length in the generatrix direction of the register roller. A recording sheet guiding device characterized in that soft guide sheets are provided at predetermined intervals along substantially the entire length of the register roller in the generatrix direction, the sheet being close to or in contact with the tip positioning portion of the register roller. It is in.

Embodiments of the present invention will be described below with reference to the drawings, in which the present invention is applied to an electrophotographic copying apparatus using a photosensitive drum as the surface of an image carrier.

FIG. 1 shows a partial cross section of a copying machine, the basic configuration of which is the same as a known copying machine. 1 is the first cassette, 2 is the second cassette, 3 is the first paper feed roller, 4
is the second paper feed roller, 5 is the first guide plate, and 6 is the second paper feed roller.
Guide plate, 7 is a guide sheet, 8 is a third guide plate, 9, 10 are a pair of register rollers, 11, 1
2 is a pair of transfer guides, 13 is an image carrier, and 14 is a transfer charger. The first guide plate 5 and the second guide plate 6 constitute a first sheet conveyance path, and the second guide plate 6 and the third guide plate 8 constitute a second sheet conveyance path. The second guide plate 6 is a guide member located at the boundary between the first sheet conveyance path and the second sheet conveyance path.

Here, the transfer material (not shown) stored in the first cassette 1 is fed by the first paper feed roller 3, and transferred to the first guide plate 5, then to the second guide plate 6, and then to the second guide plate 6. A pair of register rollers 9, 10 are guided by a guide sheet 7 installed in the
transported to.

Further, the transfer material (not shown) stored in the second cassette 2 is fed by the second paper feed roller 4 and transferred to the third guide plate 8, then to the second guide plate 2 and this second guide plate 6. The installed guide sheet 7
The paper is guided by a pair of register rollers 9 and 10 in the same manner as the transport from the first cassette.

The transfer material is further fed by the rotation of the pair of register rollers 9, 10 at a certain timing, and reaches the surface of the image carrier 13 via the pair of transfer guides 11, 12. Furthermore, the image is transferred onto the transfer material by the transfer charger 14 installed opposite the image carrier 13, and the transfer material is transported to the next step.

In the above configuration, the present invention uses a soft, low-resistance sheet (for example, a polyester sheet) with a small thickness.
is installed as a guide sheet 7 so as to extend from the second guide plate 6 to a position close to or in contact with one of the pair of register rollers 9 and 10, thereby guiding the transfer material. The feature is that the guide can be stably guided to the vicinity of the register roller.

That is, the guide sheet 7 is extremely thin (preferably about 100 to 200 μ thick) and flexible, whereas it is difficult to bring the guide plate, which is a rigid body, very close to the register rollers 9 and 10. By using a sheet having a material as its material, it is possible to bring it into contact with the register rollers 9, 10, thereby preventing the register rollers 9, 10 from being damaged, and on the other hand, the pair of transfer material guides can be brought into contact with the register rollers 9, 10. This has the effect that it can be stably applied up to the clamping part of the register rollers 9 and 10, and due to its flexibility, the same guide sheet can be placed between two different paths. This also has the advantage that it can suitably function as a guide for the transfer material fed through any path. Moreover, even if each transfer material fed through each sheet conveyance path is sent to the register rollers 9, 10 at a large angle with respect to the common tangent line of the register rollers 9, 10, the guide member located at the boundary is provided. The register rollers 9 and 10 are moved by the guide sheet that is close to or in contact with the tip positioning portion that has been aligned.
accurately guided to the common tip alignment portion of the
In addition, the suitable material that can be used as a guide sheet is the ultra-thin synthetic resin sheet such as polyester mentioned above, but the thickness and material are limited as long as it satisfies the functional conditions and is not particularly inconvenient. isn't it.

In addition, the guide sheet can be used as a second guide sheet if it guides the leading edge of the recording sheet in a straight line.
One guide sheet may be provided on the second guide plate 6 as shown in FIG.

As described above, the recording sheet guide device of the present invention can always regulate the leading edge of recording sheets fed from a simple sheet storage section at a fixed position of the common leading edge positioning part of the register roller. Therefore, there is an advantage that a stable image position can always be obtained, and its usefulness is extremely great.

[Brief explanation of drawings]

FIG. 1 is a partial sectional view of a copying machine according to an embodiment of the present invention, and FIGS. 2A and 2B are views showing different installation states of the guide sheet. 1...First cassette, 2...Second cassette, 3
...First paper feed roller, 4...Second paper feed roller, 5
...First guide plate, 6...Second guide plate, 7...
Guide sheet, 8...Third guide plate, 9, 10...
...Register roller, 11, 12...Transfer guide,
13... Image carrier, 14... Transfer charger.

Claims (1)

[Scope of utility model registration request] A guide member is provided at a boundary between the first sheet conveyance path and the second sheet conveyance path to guide the recording sheet to the tip alignment portion of the common register roller, and guides the recording sheet conveyed through each sheet conveyance path. , the tip position of the register roller is placed at the end of the guide member on the register roller side over substantially the entire length of the register roller in the generatrix direction, or at predetermined intervals over substantially the entire length of the register roller in the generatrix direction. A recording sheet guide device comprising a soft guide sheet that is close to or in contact with a mating portion.