JPH0543070A - Duplicate-feeding prevention device - Google Patents

Abstract

PURPOSE:To make an abrasion condition of a pad discoverable and simplify its acknowledging. CONSTITUTION:This device is provided with a carrying means 1 for carrying sheets; a pad 2, arranged abutting-capably in the carrying means 1 to prevent the duplicate-feeding of the sheets, and having a color or density different from those of the carrying means 1; and a light detection means 3, arranged on an opposite side to the carrying means 1 in the pad 2, and capable of detecting the color or density of the carrying means 1 when the pad 2 is worm to become a condition where light can be transmitted; and has a transparent member layer 4 on the light detection means 3 side of the pad 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double feed prevention device for an image forming apparatus.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 6, a paper feed roller 1 which is a conveyance means for feeding and conveying paper such as a copying machine and a fax has a plate for preventing double feeding of paper. The pad 2 is arranged so as to be able to contact the paper feed roller 1.
The pad 2 is attached to one end of a holding plate 21 by a screw 22, and the end portion of the holding plate 21 is supported by a support portion of the main body by a shaft 23.

When a sheet is fed, it enters between the sheet feed roller 1 and the pad 2 and is conveyed. When two sheets are fed at the same time, the sheet on the pad 2 side is not conveyed by the frictional force between the pad 2 and the sheet, and only the sheet on the sheet feed roller 1 side is conveyed.

[0004]

However, if the pad 2 wears down due to friction during its use and reaches the end of its life, problems such as no paper feed and paper jam will occur.
Therefore, it is necessary to check the wear condition of the pad 2, but with the conventional pad 2, the state is difficult to understand,
In addition, there is a problem that it is troublesome because it is necessary to check each time.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems of the conventional pad, and an object of the present invention is to provide a double feed preventing device in which the wear condition of the pad can be easily understood and its confirmation can be easily performed.

[0006]

SUMMARY OF THE INVENTION According to the present invention of claim 1, a conveying means for conveying a sheet and a two-color conveying means are arranged so as to be able to contact the conveying means in order to prevent double feeding of the sheet. And a pad formed of a member layer.

According to a fourth aspect of the present invention, a conveying means for conveying a sheet and a color different from the color or the density of the conveying means are arranged so as to be in contact with the conveying means to prevent double feeding of the sheets. Or, a density pad and a light detecting means which is arranged on the opposite side of the pad from the transportation means and which can detect the color or the density of the transportation means when the pad is worn and becomes ready to transmit light. Is a double feed prevention device.

According to the present invention of claim 8, there is provided a conveying means for conveying the paper and a color different from the color or the density of the conveying means, which is arranged so as to come into contact with the conveying means in order to prevent the double feeding of the paper. Alternatively, when the pad is worn and the light can pass through it at a predetermined position of the case cover that contains the transfer means and the pad, the transfer means is provided outside the case cover. It is a double-feeding prevention device having a window portion for recognizing from.

[0009]

According to the present invention of claim 1, the conveying means conveys the sheet, and the pad formed by the two-color member layers,
It is arranged so that it can be brought into contact with the conveying means and prevents double feeding of sheets.
Then, when the member layer on the conveying means side is worn out, the color of the other member layers changes, so that the wear is easy to understand.

According to a fourth aspect of the present invention, the conveying means conveys the sheet, and a pad having a color or a density different from the color or the density of the conveying means is arranged so as to come into contact with the conveying means to prevent the double feeding of the sheets. Then, when the pad wears and becomes ready to transmit light, the light detecting means arranged on the side of the pad opposite to the conveying means detects the color or density of the conveying means.

According to an eighth aspect of the present invention, the conveying means conveys the sheet, and a pad having a color or a density different from the color or the density of the conveying means is arranged so as to come into contact with the conveying means to prevent the double feeding of the sheets. However, when the pad is worn and is in a state where light can be transmitted through the window portion of the case cover accommodating the conveying means and the pad, the conveying means can be recognized.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of an image forming apparatus equipped with a double feed prevention device according to an embodiment of the present invention. That is, the case cover 5 is connected to the upper part of the main body 10 of the image forming apparatus at its end portion so as to be opened and closed vertically. The case cover 5 is provided with a pad 2 (for example, formed of white silicone rubber) for preventing double feeding of paper, a pressing plate 21 to which one end of the pad 2 is attached, and the like. The pressing plate 21 is connected to the supporting member of the case cover 5 by a shaft 23. The support member is provided with a spring 24, and the spring 24 is used for the pad 2
The paper feed roller 1 provided on the main body 10 side and formed of rubber or the like made of, for example, gray-colored Nosolex
Is pressed against. On the side of the spring 24, a reflection type optical sensor which is a light detecting means for detecting the density of the pad 2 and the density of the paper feed roller 1 when the pad 2 is worn and is in a state where light can pass therethrough. 3 is provided.

On the main body 10 side of the image forming apparatus provided with the paper feed roller 1, a document placing plate 17 for placing the document sheet sent by the paper feeding roller 1, and the document placing plate 17 Light source 1 for illuminating the upper manuscript paper
5, three mirrors 16 for guiding the light, which is emitted from the light source 15 and reflected from the document sheet, to a lens 14 for capturing an image; a CCD 13 for converting an optical image captured by the lens 14 into an electric signal; A heat-sensitive roll paper 11 for reproducing an image, a thermal head 12 for forming an image on the roll paper 11 by the converted electric signal, and the like are provided.

Further, as shown in FIG.
A transparent member layer 4 of the same size as the pad 2 (made of urethane rubber, for example) is provided on the side of the pressing plate 21 of, and a part of the pressing plate 21 is covered by the reflective optical sensor 3. The opening 25 is formed so that the density of the pad 2 and the density of the paper feed roller 1 can be detected when the pad 2 is worn and is in a state where light can pass therethrough.

Next, the operation of the above embodiment will be described.

As shown in FIG. 2A, the pad 2 is pressed by the pressing plate 21. The original paper sandwiched between the paper feed roller 1 and the pad 2 is placed by the paper feed roller 1 because the frictional force between the paper feed roller 1 and the original paper is larger than the frictional force between the pad 2 and the original paper. It is sent to the board 17 side.

Now, assuming that the pad 2 has been used less frequently and is hardly worn, the light projected from the light emitting portion of the reflective photosensor 3 passes through the opening 25 of the pressing plate 21 and passes through the transparent member layer 4. To reach the pad 2. Since the pad 2 is white, its reflectance is high, and most of the light that reaches the pad 2 is reflected, passes through the transparent member layer 4 again, and further passes through the opening 25 of the pressing plate 21 to reach the reflective sensor. It is detected by the light receiving unit of No. 3. In this way, pad 2
While the light is present between the transparent member layer 4 and the paper feed roller 1, the reflective sensor 3 always detects bright reflected light.

Next, as shown in FIG. 2B, the pad 2
When the paper is worn down to the surface of the transparent member layer 4 due to abrasion, the paper feed roller 1 contacts the transparent member layer 4. Therefore, the light projected from the light emitting portion of the reflective optical sensor 3 passes through the opening 25 of the pressing plate 21, passes through the transparent member layer 4, and reaches the paper feed roller 1. Since the paper feed roller 1 has a gray color, its reflectance is lower than that of the pad 2, and the reflected light is less than that of the pad 2. And
The reflected light, which is weaker than in the case of the pad 2, passes through the transparent member layer 4, passes through the opening 25 of the pressing plate 21, and is detected by the light receiving portion of the reflective photosensor 3.

As described above, by making the density of the pad 2 and the density of the paper feed roller 1 different, it is possible to detect the pad 2 that is always worn and has reached the end of its life.

Although the pressing plate 21 is provided on the back surface of the transparent member layer 4 in the above-described embodiment, the pressing member 21 is not provided but the transparent member layer 4 has the function of the pressing plate as shown in FIG. It may be

Further, by utilizing the detection value detected by the reflection type optical sensor 3 of the above-mentioned embodiment, a warning of the end of its life is displayed on the LED or LCD, printed out, or output sound. Alarm means may be provided.

Further, by using the detection value detected by the reflection type optical sensor 3 of the above embodiment, the paper feeding operation may be stopped when the life of the pad 2 is reached.

Further, in the above embodiment, the transparent member layer 4 is provided on the back surface of the pad 2, but the transparent member layer 4 may be omitted. In this case, the pad 2 is worn and contacts the paper feed roller 1. To prevent the paper feed roller 1 from breaking at the contact position,
It is possible to use a pad 2 that is wider than the width of the above, and to stop the slit at the central portion so as not to break it in two.

In the above embodiment, the pad 2 is white,
Although the paper feed roller 1 is gray in color, it is not limited to this, and any combination of colors may be used as long as the change can be recognized when detected by the light detection means, and a color sensor capable of detecting the color change in the light detection means. May be used.

Further, although the transparent member layer 4 in the above-mentioned embodiment has a transparent color, it may be semi-transparent if the light detecting means can detect the difference between the density of the pad 2 and the density of the paper feed roller 1.

Further, as shown in FIG. 4, instead of the light detecting means, the case cover 5 has a window 6 made of a transparent member.
May be provided so that the wear state of the pad 2 can always be recognized from the window 6 in the state where the case cover 5 is closed.

Further, as shown in FIG. 5, the pad 2 is formed of, for example, a two-color member layer of a blue layer B and a yellow layer Y without providing light detecting means, and the pad 2 is worn in a case cover 5 state. When the blue layer B of the pad 2 is worn out, the yellow layer Y appears on the surface so that the wear state can be easily identified by the color difference. Good. In this case, the two-layer member may be formed with the same friction coefficient so that the pad of the first layer can be continuously used for a while even when it reaches the end of its life.

[0029]

As is apparent from the above description, the present invention has the advantage that the wear condition of the pad is easy to understand and can be easily confirmed.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an image forming apparatus including a double feed prevention device according to an exemplary embodiment of the present invention.

FIG. 2 (a) is a side view of the same embodiment, and FIG. 2 (b) is a side view when the pad of the same embodiment is worn.

FIG. 3 is a side view of another embodiment.

FIG. 4 is a side view of a double feed prevention device of an embodiment according to the present invention of claim 9;

FIG. 5 is a side view of the double feed prevention device according to the first embodiment of the present invention.

FIG. 6 is a side view of a conventional double feed prevention device.

[Explanation of symbols]

 1 Paper Feed Roller 2 Pad 3 Reflective Optical Sensor 4 Transparent Member Layer 5 Case Cover 6 Window 10 Main Body 21 Holding Plate 23 Rotating Shaft 24 Spring

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location B65H 7/02 7456-3F G03G 15/00 109 7369-2H H04N 1/00 108 J 4226-5C ( 72) Inventor Shizuhisa Miyazaki 1-22 Tamatsukuri, Chuo-ku, Osaka-shi, Mita Kogyo Co., Ltd. (72) Inventor Junichi Inada, 1-2-2 Tamatsukuri, Chuo-ku, Osaka-shi, Mita Industry Co., Ltd. (72) Inventor Masahiro Shinohara 1-2-28, Tamatsukuri, Chuo-ku, Osaka, Osaka

Claims (9)

[Claims] 1. A transport means for transporting a sheet, and a pad, which is arranged so as to be able to contact the transport means and is formed of a member layer of two colors, in order to prevent double feeding of the sheet. A double feed prevention device characterized by being provided. 2. The double-feed preventing device according to claim 1, wherein one of the two layers of the pad is transparent. 3. The double feed prevention device according to claim 1, wherein the two layers of the pad have the same friction coefficient. 4. A transporting unit for transporting a sheet, and a sheet having a color or a density different from the color or the density of the transporting unit, which is arranged so as to come into contact with the transporting unit so as to prevent the double feeding of the sheet. A pad, and a light detection unit that is arranged on the opposite side of the pad from the conveying unit, and is capable of detecting the color or the density of the conveying unit when the pad is worn and becomes ready to transmit light. A double-feeding prevention device comprising: 5. The multi-feed preventing device according to claim 4, wherein the pad has a transparent member layer on the light detecting means side. 6. The double feed prevention apparatus according to claim 4, further comprising alarm means for outputting a warning signal when the light detecting means detects the color or the density of the conveying means. 7. The stopping means for stopping the transportation of the sheet based on the result when the light detecting means detects the color or the density of the transporting means. Double feed prevention device. 8. A transporting means for transporting a sheet, and a sheet of a color or a density different from that of the transporting means, which is arranged so as to come into contact with the transporting means in order to prevent double feeding of the sheet. When the pad is worn and is in a state of being able to transmit light at a predetermined position of a case cover that contains the transfer means and the pad, the transfer means is provided outside the case cover. A double-feeding prevention device having a window for recognizing from the inside. 9. The multi-feed preventing device according to claim 8, wherein the pad has a transparent member layer on the window side.