JPH073416Y2 - Paper separation device of image forming apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a sheet separating device provided in an image forming apparatus such as an electrostatographic copying machine or a facsimile, and more specifically, it is driven in reverse by an intermittent driving means. A sheet of paper having a rotating shaft that is movable in the axial direction parallel to the rotation axis of the photoconductor, and the tip of the claw comes into contact with and separates from the surface of the photoconductor as the rotation shaft rotates forward and backward. The present invention relates to a sheet separating device of an image forming apparatus in which a separating claw is provided on the rotation shaft.

[Conventional technology]

In the above-described sheet separating device, the contact position of the tip of the claw with respect to the surface of the photoconductor can be changed by moving the rotating shaft in the axial direction each time the sheet separating claw is brought into contact with or separated from the surface of the photoconductor. As a result, it is possible to effectively prevent the local deterioration of the surface of the photoconductor due to the contact of the tips of the nails.

In order to move the rotary shaft of such a sheet separating device in the axial direction, the applicant of the present invention filed Japanese Utility Model Application No. 61-25312 (Japanese Utility Model Application No. 62-137457).
Japanese patent publication) and proposes the means shown in FIGS. 7 and 8.

In this type, a sheet separating claw 43 whose tip is brought into contact with or separated from the surface of the photosensitive member by the forward and reverse rotation of the rotating shaft 42 is provided on the rotating shaft 42 which is driven in the forward and reverse directions by the intermittent driving device 41. A cam mechanism 45 is provided for moving the rotary shaft 42 in the axial direction via the one-way transmission means 44 and with the rotation of the rotary shaft 42 in either one of the forward and reverse directions. A cam member 47, which is provided between the moving shaft 42 and the cam mechanism holding member 46 and has an annular inclined cam surface S ₀ as the cam mechanism 45, is provided with the rotating shaft 42 via the one-way transmission means 44. In addition to
A cam follower 48 acting on the inclined cam surface S ₀ is provided on the apparatus side, and further, a biasing means 49 for biasing the cam follower 48 against the cam surface S ₀ is provided.

According to this structure, the rotating shaft 42 is reciprocally rotated,
Each time the tip end of the sheet separating claw 43 is brought into contact with and separated from the surface of the photoconductor, the sheet separating claw 43 is moved along with the rotating shaft 42 in the axial direction of the rotating shaft 42.

[Problems to be solved by the invention]

By the way, the cam mechanism 45 has a diameter larger than that of the rotating shaft 42. Therefore, if the cam mechanism is provided so as to be housed within the conveyance range of the sheet, the sheet separated by the sheet separating claw 43 is not fixed. Since the image is rubbed by the cam mechanism 45, one end side of the rotating shaft 42 is extended to outside the conveyance range and the cam mechanism 45 is provided at the extended end portion of the rotating shaft. Therefore, the paper separating device has a long structure,
Furthermore, there was room for improvement in terms of making the device compact.

The present invention has been made in view of such circumstances,
It is an object of the present invention to solve the above-mentioned inconvenience and achieve compactness of the device by a very simple and rational improvement.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, the present invention provides a rotating shaft that is driven in the normal and reverse directions by intermittent driving means so as to be movable in the axial direction in parallel with the rotating shaft of the photoconductor, and to rotate the rotating shaft in the normal direction. In a sheet separating device of an image forming apparatus in which a sheet separating claw whose tip comes into contact with and separates from a surface of a photosensitive member in accordance with reverse rotation is provided on the rotating shaft, the intermittent driving means drives the rotating shaft in synchronization with the rotating shaft. And a cam for arranging the rotating shaft in parallel with the rotating shaft and moving the rotating shaft in the axial direction through the one-way transmission means and with the rotation of the rotating shaft in either one of the forward and reverse directions. A mechanism is provided between the rotating shaft and the cam mechanism holding member, and further, an interlocking mechanism that moves the rotating shaft in the axial direction in association with the movement of the rotating shaft in the axial direction is provided with the rotating shaft and the rotating shaft. It is characterized in that it is provided over and.

[Operation] That is, a rotary shaft is provided separately from the rotary shaft having the sheet separating claw, and the rotary shaft is provided with a cam mechanism so that the rotary shaft is movable in the axial direction. The rotary shaft is configured to be movable in the axial direction in synchronization with each other. By arranging the rotary shaft equipped with the cam mechanism above the sheet conveying path, It is possible to avoid rubbing of an unfixed image after transfer, and it is possible to stop the rotating shaft to a minimum length required for attaching the sheet separating claw.

〔Example〕

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

FIG. 2 shows an outline of an electrostatographic copying machine as an example of an image forming apparatus. A photoconductor 3 is mounted horizontally on a copying machine main body 2 having an automatic document feeder 1 on the upper part thereof. A charging device 4, a developing device 5, and a transfer device 6 are provided around the printer, and a first paper separating device 7 of, for example, an electrostatic separation system for indirectly separating the paper adhered to the surface of the photoconductor 3 is provided. A second paper separating device 8 of a claw separation system for forcibly separating from the surface of the photosensitive drum 1 the paper that has not been completely separated indirectly by the first paper separating device 7; A cleaning device 9 for separating and collecting the residual toner is provided downstream of the transfer device 6 in that order.

An exposure device 10 is provided in the upper space of the copying machine body 2, and a paper feed cassette 11 is provided in the lower space of the copying machine body 2.
Is provided with a loading section 12 of the sheet feeding device, and a sheet feeding and conveying device 14 is provided from the sheet feeding device 13 having the function of preventing the double feeding to the transfer device 6, and the sheet feeding and feeding device 14 is manually fed in the middle of the path. While the section 15 is provided, a paper delivery / conveyance device 17 that conveys the paper after transfer / separation to the fixing device 16, a pair of paper ejection rollers 18 that delivers the paper after the fixing, and a roll paper that receives the delivered paper. A paper discharge tray 19 is provided.

The second sheet separating device 8 is configured as follows. That is, as shown in FIG. 1 and FIGS. 3 to 5, an inverted L-shaped bracket is provided on the rear surface of the cleaning device 9.
20 is provided, a solenoid 21 which is an example of intermittent driving means is attached to the lower surface of the horizontal plate portion 20a of the bracket 20, and two swing operation pieces a and b are attached to the vertical plate portion 20b of the bracket 20. The swing member 22 provided is pivotally mounted, and the input side member c of the swing member 22 is pivotally connected to the solenoid 21.

Then, from the vertical plate portion 20b of the bracket 20 to the photosensitive member 3
Side by side, a pair of support arms 23 are continuously provided, and in the state where the axis line is parallel to the rotation axis line of the photoconductor 3, a pivot shaft 24 is axially movably supported by the arm 23, and A plate-shaped arm member 25 that receives a pressing force from one of the swing operation pieces a of the swing member 22 is provided on the rotary shaft 24, and
A biasing means 26 for resisting the pressing force is provided across the arm member 25 and the horizontal plate portion 20a of the bracket 20, and further,
A plurality of sheet separating claws 27 whose tips softly contact the surface of the photoconductor by the urging force of the weight portion w are rotatably held at the rotating shaft 24 at predetermined intervals, and the sheet separating claws 27 are also held. The weight portion w of the above is locked to the upper surface of the arm member 25.

When the solenoid 21 is driven for a predetermined time at a predetermined paper peeling timing, the arm member 25 receives a pressing force from the one swinging operation piece a and rotates clockwise in FIG. When the tip of the sheet separation claw 27 comes into contact with the surface of the photoconductor, the engagement of the arm member 25 with respect to the weight portion w is released, so that the tip of the claw 27 of the sheet separation claw 27 is released. The paper that is softly contacted with the surface of the photoconductor and is not completely separated by the first paper separating device 7 is forcibly picked up by the paper separating claw 27 from the surface of the photoconductor. It is configured to be separated into.

On the other hand, two bearings 28 are provided on the side opposite to the photoconductor 3 with respect to the vertical plate portion 20b of the bracket 20 and at a position above the rotation shaft 24 with respect to the paper discharge conveyance device 17. , The rotary shaft 29 is axially movably supported by the two bearings 28 in a state where the axis is parallel to the rotary shaft line of the rotary shaft 24, and the other is synchronized with the arm member 25. The plate member 30 which receives the pressing force by the swinging operation piece b of
And a biasing means 31 that resists the above-mentioned pressing force is provided across the plate-shaped member 30 and the input side member c of the swinging member 22 so that the rotation of the solenoid 21 is stopped when the solenoid 21 is stopped. The shaft 29 is driven in the forward and reverse directions.

Then, one of the bearings 28 is used as a cam mechanism holding member,
Between the bearing 28 and one end side of the rotating shaft 29, the rotating shaft 29
A cam mechanism 32 for moving the rotary shaft 29 in the axial direction in accordance with the rotation in one direction (clockwise direction in FIG. 1) is provided, and the axial movement of the rotary shaft 29 is applied to the paper separating claw 27. The interlocking mechanism 33 for transmitting the plate-shaped member 30
And the arm member 25.

Here, the cam mechanism 32 is configured as follows.
That is, the cam member 34 having the inclined cam surface S ₀ is attached to the end portion of the rotary shaft 29 via the one-way transmission means 39, and the cam follower whose cam working end is different around the axis of the rotary shaft 29 and in the axial direction. 35 is connected to the bearing 28, and the biasing means 31 is used to bias the cam member 34 to the cam follower 35 side.

Specifically, the one-way transmission means 39 transmits only the rotation of the rotating shaft 29 by the biasing means 31 to the cam member 34 when the pressing force by the other swing operation piece b is released. And the inclined cam surface S ₀ of the cam member 34.
As shown in the development of FIG. 6, the height starts from the starting point S and gradually increases in the axial direction of the rotary shaft 29, and a drop H occurs between the ending point E and the starting point S. And the surface of the inclined cam surface S ₀ is processed by ratchet teeth.

Thus, the cam member via the one-way transmission means 39.
With the rotation of 34, the cam follower 35 relatively climbs the inclined cam surface S _{0 and} thus the ratchet teeth step by step, whereby the rotary shaft 29 moves in one axial direction, and the cam follower 35 ends. The rotation shaft 29 is configured to move in the other axial direction by ⅓ of the drop H at the time of reaching.

The interlocking mechanism 33 includes a fork-shaped locking member 33a connected to the plate member 30 and a locking member 33b connected to the arm member 25 and engaged with the locking member 33. Consists of.

According to the above configuration, by driving the solenoid 21, the arm member 25 and the plate member 30 are pressed,
By the rotation of the rotation shaft 24, the tip of the paper separation claw 27 comes into contact with the surface of the photoconductor, and the rotation shaft 29 is moved by the cam mechanism.
Spins idle against 32.

On the other hand, when the drive of the solenoid 21 is stopped, the rotating shaft 24 and the rotating shaft 29 are rotated and rotated in the opposite directions by the biasing means 26 and 31, respectively, so that the tip of the paper separating claw 27 is rotated. Is separated from the surface of the photoconductor, the rotation of the rotary shaft 29 is transmitted to the cam member 34 of the cam mechanism 32, the rotary shaft 29 moves in one axial direction (the other axial direction at the end point E), and The movement of the rotary shaft 29 in the axial direction is transmitted to the rotary shaft 24 through the interlocking mechanism 33, so that the sheet separating claw 27 attached to the rotary shaft 24 is also synchronized with the rotary shaft 24 in the axial direction. It is possible to effectively prevent the front end of the sheet separating claw 27 from moving and locally deteriorating the surface of the photoconductor.

Further, since the cam mechanism 32 for moving the paper separating claw 27 in the axial direction of the rotary shaft 24 is provided on the rotary shaft 29 different from the rotary shaft 24, the rotary shaft 24 is not provided. Can be made to have a minimum length necessary for disposing the sheet separating claw 27, and the cam mechanism 32, the rotating shaft 29, and means for driving the rotating shaft (the solenoid 21, the swinging member 22, etc.) By arranging them above 17, it is possible to avoid damaging unfixed images while keeping them within the conveyance range.

Reference numeral 36 in the figure denotes a ratchet wheel provided on the rotary shaft 24 so as to be freely rotatable. The tip of the nail projects below the lower surface of the paper separating pawl 27 and is forced by the paper separating pawl 27. When the leading edge of the separated sheet comes into contact with the sheet, it is driven to rotate, and an unfixed image of the sheet is prevented from being rubbed by the lower surface of the sheet separating claw 27. It has a function to guide you to.

S ₁ is a sensor that detects the passage of the leading edge of the paper after transfer, and when the sensor S ₁ does not detect the passage of the leading edge of the sheet when a predetermined time has elapsed after the sheet feeding sensor S ₂ detected the leading edge of the sheet. On the basis of this, it is considered that a jam has occurred in the route to the sensor S ₁ , and a jam occurrence signal is emitted.

Reference numeral 37 denotes a guide plate provided in the vicinity of the arm d of the sensor S ₁ for guiding the leading edge of the sheet toward the sensor arm d when the sheet after transfer is upward-oriented.
It is configured to reliably detect the leading edge of the paper by S ₁ .

Reference numeral 38 denotes a freely rotatable second ratchet wheel 38 provided behind the sensor arm d with respect to the guide plate 37, and prevents an unfixed image of a sheet from being rubbed by the guide plate 37. .

[Effect of device]

As described above, in the sheet separating device of the image forming apparatus according to the present invention, the cam mechanism for moving the sheet separating claw in the axial direction of the rotating shaft is provided on the rotating shaft separate from the rotating shaft. In addition to avoiding damage to unfixed images, it is possible to place the cam mechanism and the rotating shaft within the conveying range while arranging them above the conveying device. Thus, the rotating shaft can be accommodated in the minimum length necessary for the arrangement of the sheet separating claws, and further, the sheet separating device can be made compact.

[Brief description of drawings]

FIG. 1 is a side view of essential parts, FIG. 2 is a schematic vertical sectional view of an electrostatographic copying machine as an example of an image forming apparatus, FIG. 3 is an exploded perspective view of a sheet separating device, and FIG. 4 is a sheet separating device. FIG. 5 is a detailed view of the sheet separating device viewed from the sheet feeding direction, FIG. 5 is a detailed view of the sheet separating device viewed from the top, and FIG. 6 is a development view of the cam surface. 7 and 8 show a conventional example, FIG. 7 is a plan view,
FIG. 8 is a perspective view. 3 ... Photoconductor, 21 ... Intermittent drive means (solenoid), 24 ... Rotating shaft, 27 ... Paper separating claw, 28 ... Cam mechanism holding member (bearing), 29 ... Rotating shaft, 32 ... Cam mechanism, 33 ... Interlocking mechanism , 39 ...
One-way transmission means.

Claims (1)

[Scope of utility model registration request] 1. A rotary shaft, which is driven forward and backward by an intermittent drive means, is provided so as to be movable in the axial direction in parallel with the rotary shaft of a photoconductor, and with the forward and reverse rotation of the rotary shaft. In the sheet separating device of the image forming apparatus, in which the sheet separating claw whose tip is brought into contact with or separated from the surface of the photoconductor is provided on the rotary shaft,
A rotary shaft that is driven synchronously with the rotary shaft by the intermittent drive means is arranged in parallel with the rotary shaft, and the rotary shaft is rotated in either one of the forward and reverse directions through the one-way transmission means. Accordingly, a cam mechanism for moving the rotary shaft in the axial direction is provided between the rotary shaft and the cam mechanism holding member, and further,
A sheet separating device of an image forming apparatus, wherein an interlocking mechanism for moving the rotating shaft in the axial direction in association with the movement of the rotating shaft in the axial direction is provided between the rotating shaft and the rotating shaft.