JP2009075496A - Paper sheet conveyance device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a safe and inexpensive paper sheet conveyance device which can easily pulling out foreign matters such as the finger even when the foreign matters are pulled into a device body, and to provide an image forming apparatus. <P>SOLUTION: A housing 8 of the device body provided with a foreign matter entry prevention cover 20, which freely swings with a predetermined gap 30 between the cover 20 and the peripheral faces of the ejection rollers 14. That is, the foreign matter entry prevention cover 20 is continuous to the housing 8 via a hinge section 22. The hinge section 22 has spring members such as coil springs or plate springs. If the foreign matter such as a finger enters from the gap 30, the foreign matter entry prevention cover 20 retracts around the hinge section 22, as shown by an alternate long and short dash line 20', thereby widening the gap 30 between the ejection rollers 14 and the cover 20. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a sheet conveying apparatus such as a copying machine using an electrophotographic system and an image forming apparatus.

  In general, an image forming apparatus such as a facsimile machine or a copying machine includes a paper transport device for transporting a document, recording paper, or the like. As shown in FIGS. 8 and 9, the paper transport device includes a paper discharge unit 60 including a discharge roller 62 and an opposing roller 64 that nip each other to discharge the paper P that has been transported through the image forming apparatus. Have.

  In the paper discharge unit 60, the paper P adheres to the discharge roller 62 and the like due to static electricity charged on the paper P, and is difficult to peel off. The problem of getting caught in. For this reason, conventionally, in order to solve the problem of entrainment of the discharge paper P, a technique of covering a part of the discharge roller 62 with a cover is known (see Patent Document 1).

  Further, the gap 80 between the discharge roller 62 and the housing 70 of the image forming apparatus is set as narrow as possible from the viewpoint of preventing entry of foreign matter from the outside. For this reason, once foreign matter such as a finger is drawn into the housing 70 of the image forming apparatus by the discharge roller 62 and once sandwiched in the gap 80, the foreign matter cannot be easily pulled out because the gap 80 is narrow. there were.

Japanese Patent No. 2613470

  However, conventionally, no effective countermeasure has been taken to solve the problem that foreign matters such as fingers are caught in the gap 80 between the discharge roller 62 and the housing 70 of the image forming apparatus.

  For example, a method of stopping the discharge roller 62 using a torque limiter is conceivable in order to solve the problem of pinching foreign matter such as a finger. However, the use of an expensive torque limiter causes new problems such as an increase in the manufacturing cost of the sheet conveying apparatus, and if the discharge roller 62 is stopped by the torque limiter, the discharged sheet jams and causes trouble of the apparatus.

  SUMMARY OF THE INVENTION Therefore, a main object of the present invention is to provide a safe and inexpensive paper transport apparatus and image forming apparatus that can easily pull out foreign matter even if foreign matter such as a finger is drawn into the apparatus main body by a discharge roller. It is.

  According to a first aspect of the present invention, there is provided a paper transport device having a paper discharge portion having a discharge roller and an opposing roller that nip each other in order to discharge the paper that has been transported in the main body of the device. A swingable foreign matter intrusion prevention cover is provided on the housing of the device body with a predetermined gap between the surface and the foreign matter intrusion prevention cover retracts and discharges when foreign matter enters from the gap. A sheet conveying device, characterized in that a gap between a roller and a foreign matter intrusion prevention cover is widened.

  According to the first aspect of the present invention, when a foreign matter such as a finger enters from a gap between the discharge roller and the foreign matter intrusion prevention cover, the foreign matter intrusion prevention cover is retracted so that the gap between the discharge roller and the foreign matter intrusion prevention cover is widened. Therefore, even if foreign matter is drawn into the main body of the device by the discharge roller, the foreign matter intrusion prevention cover is retracted by pushing the foreign matter entry prevention cover, and the discharge roller and foreign matter entry prevention The gap with the cover widens. As a result, a space where the drawn foreign matter can be separated from the discharge roller appears between the discharge roller and the foreign matter intrusion prevention cover. As a result, a foreign object such as a finger that has been pulled in is not pinched and can be easily pulled out of the machine.

  The invention according to claim 2 is an invention dependent on the invention according to claim 1, wherein a detection means for detecting the retraction of the foreign matter intrusion prevention cover is provided, and the operation of the apparatus main body is stopped based on a signal from the detection means This is a sheet transporting device characterized in that the mechanism is configured to cause the sheet to move.

  According to the second aspect of the present invention, when the retraction of the foreign matter intrusion prevention cover is detected, the operation of the apparatus main body is stopped, so that safety can be further improved.

  According to a third aspect of the present invention, there is provided an image forming apparatus comprising the paper conveying device according to the first or second aspect.

  According to the invention of claim 3, since a safety can be ensured only by providing a foreign matter intrusion prevention cover that retracts when foreign matter such as a finger enters, a paper transport device having a simple configuration and low manufacturing cost is provided. An image forming apparatus is obtained.

  According to the present invention, by providing a foreign matter intrusion prevention cover that retracts when a foreign matter such as a finger enters, a foreign matter such as a finger that has been pulled in can be easily pulled out of the machine, and is inexpensive with excellent safety. A sheet conveying device and an image forming apparatus can be obtained.

  The above-described object, other objects, features, and advantages of the present invention will become more apparent from the following description of the best mode for carrying out the invention with reference to the drawings.

(Image forming device)
FIG. 1 is an external perspective view showing an example of an image forming apparatus incorporating a paper conveying apparatus according to the present invention. The image forming apparatus 10 includes an image reading unit 2 and an apparatus main body 4. In the apparatus main body 4, a paper transport device, a photosensitive drum, a developing device, a fixing device, and the like are provided.

  Then, the paper P drawn from the paper feed cassette 6 disposed at the lower part of the apparatus main body 4 is conveyed through the apparatus main body 4 by the paper conveying device, and the toner image formed on the photosensitive drum is transferred. Then, it is carried into the fixing device. The paper P to which the toner image has been transferred is fixed by a fixing device, discharged as a printed matter from the paper discharge unit 12 to the outside of the apparatus, and stacked on the paper discharge tray 7.

(First Embodiment of Paper Conveying Device)
Next, the first paper transport device will be described. 2, 3, and 4 show the paper discharge unit 12 of the first paper conveyance device. FIGS. 2 and 3 are a perspective view and a front view of the paper discharge unit 12 as viewed from the direction of arrow A in FIG. 1, respectively. FIG. 4 is a schematic cross-sectional configuration diagram of the paper discharge unit 12.

  The paper discharge unit 12 includes a discharge roller 14 and a counter roller 16 that nip each other in order to discharge the paper P that has been conveyed in the apparatus main body 4. The discharge roller 14 is rotationally driven counterclockwise as shown in FIG. 4 by a drive motor mounted on the image forming apparatus main body. On the other hand, the opposing roller 16 rotates following the rotational driving of the discharge roller 14.

  In the housing 8 of the apparatus main body 4, a portion 8 a facing the outer peripheral surface of the discharge roller 14 is notched in a concave shape for each of the discharge rollers 14, and a predetermined gap is formed between the portion 8 a and the outer peripheral surface of the discharge roller 14. A plurality of swingable foreign matter intrusion prevention covers 20 are provided. That is, each foreign matter intrusion prevention cover 20 is connected to the housing 8 via the hinge portion 22. The hinge portion 22 is provided with a spring member (not shown) such as a coil spring or a leaf spring. When a foreign object such as a finger enters from the gap 30, the foreign object intrusion prevention cover 20 retreats as shown by a one-dot chain line 20 ′ in FIG. It is comprised so that the clearance gap 30 with the cover 20 may be expanded.

  In the paper discharge unit 12 having the above configuration, when a foreign matter such as a finger that has entered the gap 30 between the discharge roller 14 and the foreign matter intrusion prevention cover 20 is drawn into the apparatus main body 4 by the discharge roller 14, it is drawn in. The foreign matter pushed against the spring force of the spring member provided on the hinge portion 22 pushes the foreign matter intrusion prevention cover 20. As a result, the foreign matter intrusion prevention cover 20 swings (retracts) backward with the hinge portion 22 as a fulcrum, as shown by a one-dot chain line 20 'in FIG. 4, and a gap 30 between the discharge roller 14 and the foreign matter intrusion prevention cover 20 is formed. spread. A space where the drawn foreign matter can be separated from the discharge roller 14 appears between the discharge roller 14 and the foreign matter intrusion prevention cover 20. As a result, a foreign object such as a drawn finger is not caught and can be easily pulled out of the apparatus main body 4, and a paper transport apparatus with excellent safety can be obtained.

  When the foreign matter is pulled out and removed from the apparatus main body 4, the foreign matter intrusion prevention cover 20 is returned to its original position by the spring force of the spring member provided on the hinge portion 22.

(Second Embodiment of Paper Conveying Device)
Next, the second paper transport device will be described. 5, FIG. 6 and FIG. 7 show the paper discharge unit 12 of the second paper transport device, and FIG. 5 is a partially enlarged front view of the paper discharge unit 12 as seen from the direction of arrow A in FIG. FIG. 6 is a right side view showing the main part, and FIG. 7 is a plan view showing the positional relationship between the optical sensor 50 and the foreign matter intrusion prevention cover 40. 5 to 7, parts and portions that are the same as those of the first sheet conveying device shown in FIGS. 2 to 4 are given the same reference numerals, and detailed descriptions thereof are omitted.

  In the housing 8 of the apparatus main body 4, a portion 8 a facing the outer peripheral surface of the discharge roller 14 is cut out in a concave shape for each discharge roller 14. The foreign matter intrusion prevention cover 40 is a plate having a length that can be disposed over the four portions 8a, and at least one of the left and right ends is provided with a fan-shaped detection piece 41. Yes. The foreign matter intrusion prevention cover 40 is swingably provided with a predetermined gap 30 between the outer peripheral surface of the discharge roller 14. In other words, the foreign matter intrusion prevention cover 40 is connected to the housing 8 via the hinge portion 22. The hinge portion 22 is provided with a spring member (not shown) such as a coil spring or a leaf spring. When a foreign object such as a finger enters from the gap 30, the foreign object intrusion prevention cover 40 is retreated as shown by a one-dot chain line 40 ′ in FIG. The gap 30 with the cover 40 is configured to widen.

  Further, an optical sensor 50 is disposed in the vicinity of the detection piece 41 of the foreign matter intrusion prevention cover 40. As indicated by a one-dot chain line 40 ′ in FIG. 6, when the foreign matter intrusion prevention cover 40 is retracted and the detection piece 41 blocks the detection light of the optical sensor 50, the optical sensor 50 transmits a detection signal to the control unit of the image forming apparatus 10. Send to.

  In the paper discharge unit 12 having the above configuration, when a foreign matter such as a finger that has entered the gap 30 between the discharge roller 14 and the foreign matter intrusion prevention cover 40 is drawn into the apparatus main body 4 by the discharge roller 14, the paper is drawn in. The foreign matter pushed against the spring force of the spring member provided on the hinge portion 22 pushes the foreign matter intrusion prevention cover 40. As a result, the foreign matter intrusion prevention cover 40 swings (retracts) backward with the hinge portion 22 as a fulcrum, as shown by a one-dot chain line 40 ′ in FIG. 6, so that a gap 30 between the discharge roller 14 and the foreign matter intrusion prevention cover 40 is formed. spread. A space where the drawn foreign matter can be separated from the discharge roller 14 appears between the discharge roller 14 and the foreign matter intrusion prevention cover 40. As a result, a foreign object such as a finger that has been pulled in is not caught and can be easily pulled out of the apparatus body 4.

  On the other hand, when the foreign matter intrusion prevention cover 40 is retracted and the detection piece 41 blocks the detection light of the optical sensor 50, the optical sensor 50 sends a detection signal to the control unit of the image forming apparatus 10. Based on the detection signal, the control unit turns off the safety switch of the image forming apparatus 10 to stop the operation of the image forming apparatus 10. Thereby, safety can be further improved.

  In the present invention, even if a foreign object such as a finger is caught between the discharge rollers 14, it can be easily pulled out. Therefore, the operation of the image forming apparatus 10 is not stopped at the moment when the safety switch is turned off. If the operation is stopped with a time lag of about 2 seconds, the frequency at which the apparatus stops can be reduced without significantly reducing safety.

  When the foreign matter is pulled out and removed from the apparatus main body 4, the foreign matter intrusion prevention cover 40 is returned to its original position by the spring force of the spring member provided on the hinge portion 22.

  In addition, this invention is not limited to the said embodiment, A various deformation | transformation is carried out within the range of the summary. For example, in the case where the foreign matter intrusion prevention cover 20 is provided for each discharge roller 14 as in the first paper transport device, a flexible member such as a PET film is attached to the housing 8 with a double-sided tape. Thus, the foreign matter intrusion prevention cover 20 may be used.

1 is an external perspective view showing an example of an image forming apparatus according to the present invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a paper discharge unit as viewed from the direction of arrow A in FIG. FIG. 3 is a front view of the paper discharge unit shown in FIG. 2. FIG. 3 is a schematic cross-sectional configuration diagram of a paper discharge unit shown in FIG. 2. FIG. 2 is a partially enlarged front view of a paper discharge unit as viewed from the direction of arrow A in FIG. 1, showing a second embodiment of the paper transport device according to the present invention. FIG. 6 is a right side view illustrating a main part of the paper discharge unit illustrated in FIG. 5. FIG. 6 is a plan configuration diagram showing a positional relationship between the optical sensor shown in FIG. 5 and a foreign matter intrusion prevention cover. FIG. 10 is a perspective view of a paper discharge unit of a conventional paper transport device. FIG. 9 is a schematic cross-sectional configuration diagram of the paper discharge unit shown in FIG. 8.

Explanation of symbols

DESCRIPTION OF SYMBOLS 8 Housing | casing 10 Image forming apparatus 12 Paper discharge part 14 Discharge roller 16 Opposite roller 20,40 Foreign matter intrusion prevention cover 22 Hinge part 30 Crevice 41 Detection piece 50 Optical sensor

Claims (3)

A paper transport device having a paper discharge section provided with a discharge roller and an opposing roller that nip each other to discharge the paper that has been transported through the apparatus body,
A swingable foreign matter intrusion prevention cover having a predetermined gap between the outer peripheral surface of the discharge roller is provided on the housing of the apparatus main body, and when foreign matter enters from the gap, the foreign matter intrusion cover is provided. A sheet transporting device, wherein the blocking cover is retracted so that a gap between the discharge roller and the foreign matter intrusion blocking cover is widened.   2. The sheet transport according to claim 1, further comprising a detection unit that detects retraction of the foreign matter intrusion prevention cover, and is configured to stop the operation of the apparatus main body based on a signal from the detection unit. apparatus.   An image forming apparatus comprising the sheet conveying device according to claim 1.

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