JP5177509B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus such as a printer, a copying machine, and a facsimile.

  This type of image forming apparatus includes a paper discharge unit that discharges a sheet on which an image is printed. Specifically, a pair of discharge rollers are provided in the paper discharge unit, and a sheet on which an image has been formed is discharged from the image forming apparatus main body by driving the discharge rollers.

  On the other hand, there is known means for preventing foreign matter from entering the discharge roller when the apparatus opening / closing part is opened or closed for sheet replenishment or jam processing. (Patent Documents 1 to 5).

JP2001-205896 JP2001-213522A JP2001-341903A Japanese Utility Model 06-060006 JP 08-006338 A

  Since the discharge roller is exposed to the outside in the paper discharge unit, foreign matter may enter the image forming apparatus as the discharge roller is driven. Therefore, when foreign matter enters, it is necessary to stop the driving of the discharge roller immediately and stop further entry of the foreign matter.

  The present invention provides an image forming apparatus in which when a foreign matter enters from a paper discharge unit of an image forming apparatus main body, the drive of the discharge roller is stopped to prevent further foreign matter from entering, and the removal work of the foreign matter that has entered can be simplified. It is intended to provide.

According to a first aspect of the present invention, there is provided an image forming apparatus main body, a discharge roller for discharging a sheet, a cover that is openable and closable with respect to the image forming apparatus main body, a cover that covers the discharge roller, and the opening and closing of the cover. a cover closing sensor sensing, have a, and control means for controlling the driving of the discharge roller based on a detection result of the cover opening and closing sensor, the cover, the foreign substance which has entered between the discharge roller and the cover It pushed out from the image forming apparatus main body by moving an image forming apparatus comprising an open state.

  Therefore, according to the present invention, when foreign matter enters the discharge roller, the discharge roller stops driving as soon as the cover is opened, and no further foreign matter enters, and the foreign matter is removed. An easy-to-use image forming apparatus can be obtained.

The present invention according to claim 2, wherein the cover is an image forming apparatus according to claim 1, wherein is supported swingably to the image forming apparatus main body in the sheet conveyance direction upstream side.

According to a third aspect of the present invention, an engaging portion is provided in the image forming apparatus main body, and an engaged portion that engages with the engaging portion is provided in the cover. 3. The image forming apparatus according to claim 1, wherein the cover is opened by disengaging from the engaged portion.
A fourth aspect of the present invention is the image forming apparatus according to any one of the first to third aspects, wherein the cover moves in a direction away from the discharge roller when pressed by the foreign matter.
The present invention according to claim 5 is the image forming apparatus according to any one of claims 1 to 4, further comprising a limiting unit that limits a movable distance of the cover.

  According to the present invention, even if a foreign object enters the discharge roller constituting the paper discharge unit, the foreign object can be removed immediately.

Embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows an image forming apparatus 10 according to an embodiment of the present invention.
The image forming apparatus 10 includes an image forming apparatus main body 12, an image forming unit 14 is mounted in the image forming apparatus main body 12, and a paper discharge unit 16 is provided on the upper portion of the image forming apparatus main body 12. For example, two-stage sheet feeding units 18 and 18 are disposed below the image forming apparatus main body 12.

  Each paper feed unit 18 includes a paper feed unit main body 20 and a paper feed cassette 22 in which a recording medium such as a sheet is stored. The paper feed cassette 22 is slidably attached to the paper feed unit main body 20 and is pulled out in the front direction (right direction in FIG. 1). In addition, a pickup roll 24 is disposed in the upper part near the rear end of the paper feed cassette 22, and a retard roll 26 and a feed roll 28 are disposed behind the pickup roll 24.

  The conveyance path 32 is a recording medium path from the pickup roll 24 to the paper discharge port 34 of the lowermost sheet feeding unit 18, and this conveyance path 32 is in the vicinity of the back surface (left side surface in FIG. 1) of the image forming apparatus main body 12. In this case, there is a portion that is formed substantially vertically from the pickup roll 24 to the fixing device 36 of the lowermost sheet feeding unit 18. A transfer device 44 and an image carrier 46 are disposed on the upstream side of the fixing device 36 in the conveyance path 32, and a resist roll 38 is disposed on the upstream side of the transfer device 44 and the image carrier 46. Further, a drive discharge roll 40 and a driven discharge roll 42 constituting the discharge roller of the present invention are disposed in the vicinity of the discharge port 34 of the conveyance path 32. A discharge roller cover 66 constituting the cover of the present invention, which is formed so as to cover the drive discharge roll 40 and the driven discharge roll 42, can be opened and closed with respect to the image forming apparatus main body 12. Is provided.

  Accordingly, the recording medium fed from the paper feed cassette 22 of the paper feed unit 18 by the pickup roll 24 is fed by the retard roll 26 and the feed roll 28 and guided to the transport path 32, and is temporarily stopped by the registration roll 38, Then, a developer image is transferred between a transfer device 44 and an image carrier 46, which will be described later, and the transferred developer image is fixed by a fixing device 36, and a driving discharge roll 40 and a driven discharge roll 42 are transferred. As a result, the paper is discharged from the paper discharge port 34 to the paper discharge unit 16.

However, in the case of duplex printing, it is returned to the reverse path.
That is, the drive discharge roll 40 and the driven discharge roll 42 in the transport path 32 are divided into two forks, and a switching claw 48 is provided at the divided portion, and the reverse path 50 returns from the divided portion to the registration roll 38. Is formed. The reversing path 50 is provided with transport rolls 52a to 52c. In the case of double-sided printing, the switching claw 48 is switched to the side that opens the reversing path 50, and the recording medium is transferred to the drive discharge roll 40 and the driven discharge roll 42. The drive discharge roll 40 is reversed at a time point before the rear end of the recording medium, the recording medium is guided to the reverse path 50, and passes through the registration roll 38, the transfer device 44, the image carrier 46, and the fixing device 36 from the discharge port 34. The paper is discharged to the paper discharge unit 16.

The image forming means 14 is of an electrophotographic type, and is charged by the image carrier 46 made of a photosensitive member, a charging device 54 made of, for example, a charging roll for uniformly charging the image carrier 46, and the charging device 54. An optical writing device 56 for writing a latent image on the image carrier 46 with light, and a developing device 58 having a developing roll so that the latent image of the image carrier 46 formed by the optical writing device 56 is visualized with toner, A transfer device 44 composed of, for example, a transfer roll for transferring a toner image by the developing device 58 to a recording medium, a cleaning device 60 for cleaning toner remaining on the image carrier 46, and a recording medium transferred by the transfer device 44 The fixing unit 36 fixes the toner image on the recording medium. The optical writing device 56 comprises, for example, a scanning type laser exposure device, and forms a latent image on the image carrier 46 across a process cartridge 62 described later. The optical writing device 56 may use an LED, a surface emitting laser, or the like as another embodiment.

  In the process cartridge 62, the image carrier 46, the charging device 54, the developing device 58, and the cleaning device 60 are integrated, and these can be replaced as a unit. The process cartridge 62 can be removed from the image forming apparatus main body 12 by opening the opening / closing unit 30 provided in the paper discharge unit 16.

  As shown in FIG. 2, the paper discharge unit 16 includes a drive discharge roll 40, a driven discharge roll 42, and a discharge roller cover 66. The discharge roller cover 66 is swingably supported on a shaft 68 provided on the upper part of the image forming apparatus main body 12 on the upstream side of sheet conveyance. On the sheet conveyance path surface side of the discharge roller cover 66, a sensor detection unit 70 is formed to protrude downward.

  On the other hand, the image forming apparatus main body 12 is provided with a cover opening / closing sensor 72 in the vicinity of the tip of the sensor detection unit 70. The cover open / close sensor 72 is, for example, a photo sensor, and detects the presence or absence of the sensor detection unit 70 in the axial direction of the drive discharge roll 40.

  FIG. 2A shows a normal state in which no foreign matter has entered the paper discharge unit 16. In FIG. 2A, the discharge roller cover 66 is in a closed state, and therefore the sensor detection unit 70 is positioned below the detection position of the cover opening / closing sensor 72.

  FIG. 2B shows a state in which foreign matter has entered the paper discharge unit 16. The foreign matter that has entered from the sheet discharge side moves between the drive discharge roll 40 and the discharge roller cover 66 due to the drive discharge roll 40 being rotated, and contacts the discharge roller cover 66. Then, since the discharge roller cover 66 is swingably supported by the image forming apparatus main body 12 by the shaft 68, the discharge roller cover 66 is pushed upward and opened by contact with a foreign substance. Along with this, the sensor detection unit 70 also moves to the detection position of the upper cover opening / closing sensor 72.

  Here, the control means for controlling the driving of the discharge roller of the present invention will be described. FIG. 3 is a block diagram showing a circuit configuration until the detection by the cover opening / closing sensor 72 stops the motor drive of the drive discharge roll 40. As shown in FIG. 3, the cover opening / closing sensor 72 detects the presence or absence of the sensor detection unit 70 in the detection region, and controls the signal with detection when the sensor detection unit 70 detects the presence in the detection region. To the unit 64. The control unit 64 determines that the discharge roller cover 66 is in an open state based on a signal with detection by the sensor detection unit 70, and a drive motor stop signal to a drive motor (not shown) of the drive discharge roll 40. To send.

    FIG. 4 is a flowchart showing the process (S10) for controlling the drive of the drive discharge roll 40 in the control unit 64. As shown in FIG. 4, in step 100 (S100), it is determined whether or not the cover opening / closing sensor 72 has detected the sensor detection unit 70 at the detection position. If not detected, that is, if the detection signal is OFF, the process proceeds to S102, and if not, the process proceeds to S104. In S102 (S102), it is determined to drive the drive motor of the drive discharge roll 40. In S104 (S104), it is determined to stop the drive motor of the drive discharge roll 40.

Next, a second embodiment of the present invention will be described with reference to FIGS.
The discharge roller cover 66 according to the second embodiment is the same as the discharge roller cover 66 according to the first embodiment in that the sensor detection unit 70 protrudes downward. Further, the discharge roller cover 66 is provided with four engagement portions 74 that are engaged with the image forming apparatus main body toward the sheet conveyance path side, two at each end in the sheet conveyance direction. Further, on the upstream side in the sheet conveying direction, one elliptical attachment portion 78 is formed projecting downward at each end of the cover. A long hole 80 that is long in the vertical direction is formed in the mounting portion 78, and a pin 82 provided in the main body of the image forming apparatus is movably fitted in the long hole 80. Accordingly, the discharge roller cover 66 can move up and down through the long hole 80 by a length that allows the pin 82 to move.

  On the other hand, the image forming apparatus main body 12 is provided with four claw portions 82 that engage with the engaging portion 74 described above, and a pin 82 that fits into a long hole 80 formed in the attachment portion 78. ing. Further, a cover opening / closing sensor 72 for detecting the presence / absence of the sensor detection unit 70 is provided in the vicinity of the tip of the sensor detection unit 70, and the control unit 64 determines whether the drive discharge roll 40 has The instruction to stop the drive motor is the same as in the first embodiment.

  FIG. 5A and FIG. 6A show a normal state in which no foreign matter enters the paper discharge unit 16. In FIG. 5A, the discharge roller cover 66 is in a closed state, and therefore the sensor detection unit 70 is positioned below the detection position of the cover opening / closing sensor 72. Moreover, in Fig.6 (a), it is the state which the engaging part 74 and the nail | claw part 84 engaged.

  FIGS. 5B and 6B show a state in which foreign matter has entered the paper discharge unit 16. The foreign matter that has entered from the sheet discharge side moves between the drive discharge roll 40 and the discharge roller cover 66 by the drive of the drive discharge roll 40, and comes into contact with the discharge roller cover 66. Then, the discharge roller cover 66 is pushed upward by the foreign matter, and thereby the engagement between the engaging portion 74 provided on the discharge roller cover 66 and the claw portion 84 provided on the image forming apparatus main body is released. The cover is open.

  At this time, the upward movement distance of the discharge roller cover 66 is limited to the distance that the pin 82 provided in the main body of the image forming apparatus can move within the elongated hole 80 formed in the attachment portion 78. Further, as the discharge roller cover 66 moves upward, the sensor detection unit 70 also moves to the detection position of the upper cover opening / closing sensor 72. As in the first embodiment, the cover opening / closing sensor 72 transmits detection data indicating that the discharge roller cover 66 is open to the control unit 64, and the control unit 64 drives the drive discharge roll 40. An instruction to stop the motor is transmitted.

Next, a third embodiment of the present invention will be described with reference to FIG.
As in the first embodiment, the discharge roller cover 66 in the third embodiment is swingably supported on a shaft 68 provided on the upper part of the image forming apparatus main body 12 so as to be swingable. Is provided with a sensor detection unit 70 protruding downward. Further, a first connecting member 86 extends toward the drive discharge roll 40, and one end of a second connecting member 88 is rotatably attached to the tip of the first connecting member 86. . The other end of the second connecting member 88 is provided so as to cover the periphery of the fixing device 36, and one end of a rear cover 90 for removing the fixing device 36 is also rotatably attached. . The rear cover 90 is swingably supported by a shaft 92 provided on the side surface of the image forming apparatus main body 12.

FIG. 7A shows a normal state in which no foreign matter enters the paper discharge unit 16.
When foreign matter enters here, the foreign matter moves upward in accordance with driving of the drive discharge roll 40, and acts as a force for pushing the discharge roller cover 66 upward. Then, as shown in FIGS. 7B to 7C, when the discharge roller cover 66 is pushed by the foreign matter, the shaft 68 is swung around the fulcrum, and the cover is opened. Then, the first connecting member 86 and the second connecting member 88 attached to the discharge roller cover 66 move so as to be pulled by the discharge roller cover 66.

  Here, since the rear cover 90 is swingably mounted about the shaft 92 as a fulcrum, the rear cover 90 swings about the shaft 92 as the second connecting member 88 moves, and the rear cover 90 is also opened. It becomes a state. As a result, when the discharge roller cover 66 is opened, the rear cover 90 is also opened, and the sensor detection unit 70 is moved to the detection position of the cover opening / closing sensor 72. Therefore, when the discharge roller cover 66 is opened, the rear cover 90 is opened, and when the cover opening / closing sensor 72 detects the sensor detection unit 70, the driving of the drive discharge roll 40 is stopped.

  Here, in the third embodiment, since the discharge roller cover 66 and the rear cover 90 are configured to open in conjunction with each other, not only the case where the discharge roller cover 66 is opened due to the entry of foreign matter but also the rear cover. Even when 90 is opened, the discharge roller cover 66 is opened. Even in this case, the drive motor of the drive discharge roll 40 is stopped by the function of the cover opening / closing sensor 72.

  With this configuration, the motor drive of the drive discharge roll 40 is stopped even when the rear cover 90 is opened, while the motor drive of the drive discharge roll 40 is stopped when foreign matter enters from the discharge roller cover 66. Therefore, it is not necessary to attach a sensor to each cover, and the number of sensors in the entire image forming apparatus can be reduced.

  In this embodiment, the discharge roller cover 66 and the rear cover 90 for removing the fixing device 36 are configured to open in conjunction with each other. However, the present invention is not limited to this. Another cover, for example, the opening / closing unit 30 of the paper discharge unit 16 provided for taking out the process cartridge 62 may be configured to open.

  Further, the cover open / close sensor 72 is not limited to a photo sensor, and may be another type of sensor.

1 is an overall view of an image forming apparatus according to an embodiment of the present invention. 2A and 2B are side views of the sheet discharge apparatus according to the first embodiment of the present invention, in which FIG. 1A shows a state in which no foreign matter has entered the paper discharge unit, and FIG. Indicates the state. It is a block diagram which shows the circuit structure which stops the motor drive of a discharge roller when a cover is opened. It is a flowchart which shows the control process (S10) which stops the motor drive of a discharge roller when a cover is opened. 7A and 7B are side views of a sheet discharge apparatus according to a second embodiment of the present invention, where FIG. 5A shows a state in which no foreign matter has entered the paper discharge unit, and FIG. Indicates the state. 7A and 7B are front sectional views of a sheet discharge apparatus according to a second embodiment of the present invention, in which FIG. 5A shows a state in which no foreign matter has entered the paper discharge unit, and FIG. Indicates the state. FIG. 6A is a side view of a sheet discharge apparatus according to a third embodiment of the present invention, in which FIG. 5A shows a state in which no foreign matter has entered the discharge section, and FIGS. Indicates the state that foreign matter has entered.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 12 Image forming apparatus main body 14 Image forming means 16 Paper discharge part 18 Paper feed unit 20 Paper feed unit main body 22 Paper feed cassette 24 Pickup roll 26 Retard roll 28 Feed roll 30 Opening / closing part 32 Transport path 34 Paper discharge port 36 Fixing device 38 Registration roll 40 Driven discharge roll 42 Followed discharge roll 44 Transfer device 46 Image carrier 48 Switching claw 50 Reverse path 52a-52c Conveying roll 54 Charging device 56 Optical writing device 58 Developing device 60 Cleaning device 62 Process cartridge 64 Control unit 66 Discharge roller cover 68 Shaft 70 Sensor detection part 72 Cover opening / closing sensor 74 Engagement part 76 Control part 78 Attachment part 80 Elongate hole 82 Pin 84 Claw part 86 First connection member 88 Second connection member 90 Rear cover 92 Axis

Claims (5)

An image forming apparatus main body;
A discharge roller for discharging the sheet;
A cover that is openable and closable with respect to the image forming apparatus main body and covers the discharge roller;
A cover opening / closing sensor for detecting opening / closing of the cover;
Control means for controlling the driving of the discharge roller based on the detection result of the cover opening / closing sensor;
I have a,
The image forming apparatus, wherein the cover is released from the main body of the image forming apparatus by being pushed and moved by foreign matter that has entered between the cover and the discharge roll, and is in an open state .   The image forming apparatus according to claim 1, wherein the cover is swingably supported by the main body of the image forming apparatus on the upstream side in the sheet conveying direction. An engagement portion is provided in the image forming apparatus main body,
An engaged portion that engages with the engaging portion is provided on the cover,
The image forming apparatus according to claim 1, wherein the engagement portion and the engaged portion are disengaged and the cover is opened. The image forming apparatus according to claim 1, wherein the cover moves in a direction away from the discharge roller when pressed by the foreign matter. The image forming apparatus according to claim 1, further comprising a limiting unit that limits a movable distance of the cover.

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