JP5838494B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus, and more particularly to an improvement in a recording material feeding method.

  Conventionally, when the paper is special paper such as gloss coated paper that is likely to be double-fed, after the paper enters the feed roller, the paper is separated from the pick roller, and then the trailing edge of the paper being fed 2. Description of the Related Art A sheet feeding device that can re-contact a sheet with a pick roller after the sheet is removed from the pick roller is known (for example, Patent Document 1). As a result, the driving load and the conveying load at the time of paper feeding are reduced, and the tension applied to the paper is reduced.

  In addition, an image forming apparatus that can release the press of the lift plate and the separating member against the paper feed roller after the front end portion of the paper is in contact with the resist roller pair and before the resist roller pair is rotationally driven. Conventionally known (for example, Patent Document 2).

  Further, an image forming apparatus that can press the sheet separating member against the sheet feeding member in conjunction with the lifting mechanism is also known (for example, Patent Document 3).

JP 2009-040607 A JP 2009-2442025 A JP 2009-001350 A

  Here, in the devices of Patent Documents 1 to 3, the push-up plate is moved up and down by a driving force transmission mechanism such as a gear. As a result, the timing at which the uppermost recording material reaches the paper feed roller varies depending on the number of recording materials loaded. As a result, there arises a problem that the recording material cannot be fed at a fixed timing. In particular, when a registration roller for timing adjustment is not provided between the paper feeding roller and the transfer roller, this timing variation becomes a problem.

  Accordingly, an object of the present invention is to provide an image forming apparatus that can feed a recording material satisfactorily toward a forming unit.

In order to solve the above-mentioned problem, the invention of claim 1 is characterized in that the mounting unit on which a plurality of recording materials are mounted and the mounting unit mounted on the mounting unit by rotating according to a driving force from a driving source. a paper feed roller for feeding paper to the top layer of the target recording material of the plurality of recording materials, the push-up plate which can swing as toward and away from to the feed rollers, closer to the sheet feed roller comprising an urging member always imparting force to the push-up plate in accordance with the driving force from the driving source, a swing and a pivot portion you rotate around a rotation axis, wherein the oscillating member, prior Symbol The rotary shaft is provided in parallel with the rotary shaft and spaced apart from the rotary shaft, and in contact with the upper surface of the recording material of interest via the plurality of recording materials in accordance with a rotation operation around the rotary shaft. And a movable part that swings the push-up plate. That.

  According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the movable portion is rotatable about a movable axis parallel to the rotation axis.

According to a third aspect of the present invention, in the image forming apparatus according to the first or second aspect, while the swinging portion makes one rotation when the driving force is applied, characterized by feeding the paper to the attention recording material.

  In the invention according to any one of claims 1 to 3, the push-up plate is biased by a biasing member, and the height position of the uppermost recording material of the plurality of recording materials is regulated by the movable portion. Is done. Thereby, the height position of the recording material of interest is always constant regardless of the number of recording materials placed on the placement portion. For this reason, the push-up plate can bring the recording material of interest into contact with the paper feed roller at a constant timing regardless of the number of recording materials placed on the placement portion, and is moved to the forming portion side at a constant timing. The recording material of interest can be fed.

  In particular, according to the second aspect of the present invention, the movable part is rotatable about a movable axis parallel to the rotational axis of the swinging part. Thus, even when the swinging portion rotates and the movable portion is eccentric, the movable portion can press each recording material without damaging each recording material. Therefore, the movable part can swing the push-up plate well.

  In particular, according to the third aspect of the present invention, for example, the recording material of interest can be conveyed directly from the paper feed roller to the forming portion without further providing a part such as a registration roller. Therefore, the number of parts required for the paper feeding operation can be reduced.

1 is a front view illustrating an example of a configuration of an image forming apparatus according to an embodiment of the present invention. FIG. 6 is a side perspective view illustrating an example of a configuration of a sheet feeding unit. FIG. 6 is a front perspective view illustrating an example of a configuration of a sheet feeding unit. FIG. 4 is a side view illustrating an example of a configuration of a sheet feeding unit. It is a rear view which shows an example of a structure of a rocking | swiveling part vicinity. It is a skeleton figure of the power transmission system in the paper feed unit of the first and second embodiments. It is sectional drawing of the raising board vicinity seen from the VV line | wire of FIG. It is sectional drawing of the raising board vicinity seen from the VV line | wire of FIG. It is sectional drawing of the raising board vicinity seen from the VV line | wire of FIG. It is sectional drawing of the raising board vicinity seen from the VV line | wire of FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<1. Configuration of image forming apparatus>
FIG. 1 is a front view showing an example of the configuration of an image forming apparatus 1 according to an embodiment of the present invention. Here, the image forming apparatus 1 prints the toner image on the recording material P by electrophotography. As shown in FIG. 1, the image forming apparatus 1 mainly includes a forming unit 10, a fixing unit 20, a paper feeding unit 30, a paper discharging unit 50, and a control unit 90. In FIG. 1 and the subsequent drawings, an XYZ orthogonal coordinate system in which the Z-axis direction is the vertical direction and the XY plane is the horizontal plane is appropriately attached as necessary.

  The forming unit 10 transfers the toner image to the recording material P. As shown in FIG. 1, it mainly includes a photosensitive drum 13, a developing unit 16, a transfer roller 18, and an exposure unit 19.

  The photosensitive drum 13 has a cylindrical shape or a columnar shape, and is disposed to face the transfer roller 18. A photoconductive film is provided on the outer peripheral surface 13 a of the photosensitive drum 13. Accordingly, light is applied to the outer peripheral surface 13a of the photosensitive drum 13 from the fixing unit 20, and the electrostatic latent image is formed on the outer peripheral surface 13a of the photosensitive drum 13 by removing the charges on the irradiated portion. .

  The developing unit 16 supplies a developer (including toner) to the photosensitive drum 13 on which the electrostatic latent image has been formed, thereby generating a toner image based on the electrostatic latent image on the outer peripheral surface 13a of the photosensitive drum 13. Form. As shown in FIG. 1, the developing unit 16 has a developing roller 17.

  The developer supplied from the developing unit 16 to the photosensitive drum 13 may be a one-component developer that does not use a carrier, or a two-component developer that includes toner and a carrier. Also good.

  Similar to the photosensitive drum 13, the transfer roller 18 has a cylindrical shape or a columnar shape. A charge having a polarity opposite to that of the outer peripheral surface 13 a of the photosensitive drum 13 is applied to the outer peripheral surface 13 a of the transfer roller 18. Thus, when the recording material P is sandwiched between the photosensitive drum 13 and the transfer roller 18 while the photosensitive drum 13 and the transfer roller 18 are rotating, the recording material P is placed on the outer peripheral surface 13 a of the photosensitive drum 13. The formed toner image is transferred.

  The exposure unit 19 forms an electrostatic latent image on the outer peripheral surface 13 a of the photosensitive drum 13 by emitting laser light toward the rotated photosensitive drum 13. The fixing unit 20 fixes the toner image transferred onto the recording material P. As shown in FIG. 1, the fixing unit 20 is disposed on the downstream side of the transfer roller 18 in the conveyance direction of the recording material P (corresponding to the arrow AR1 direction: hereinafter, also simply referred to as “conveyance direction”). .

  The paper feed unit 30 is used as a supply unit that supplies the recording material P to the forming unit 10. The detailed configuration of the paper feeding unit 30 will be described later.

  The paper discharge unit 50 is provided on the downstream side of the fixing unit 20 in the transport direction, and discharges the recording material P on which the toner image is fixed to the outside of the apparatus. As shown in FIG. 1, the paper discharge unit 50 mainly includes a paper discharge roller 51 and a paper discharge tray 52.

  As shown in FIG. 1, the control unit 90 is provided below the forming unit 10 and the fixing unit 20. The control unit 90 realizes operation control of each element of the image forming apparatus 1 and data calculation. For example, the control unit 90 receives an image signal from an external terminal (not shown), converts it into digitized image data, and controls the operations of the forming unit 10 and the paper feeding unit 30 to record the image signal. The printing process on the material P is executed.

<2. Configuration of paper feed unit>
FIGS. 2 to 4 are a side perspective view, a front perspective view, and a side view, respectively, showing an example of the configuration of the paper feeding unit 30. FIG. 5 is a rear view showing an example of the configuration in the vicinity of the swinging portion 40. FIG. 6 is a skeleton diagram of a power transmission system in the paper feeding unit 30. 7 and 8 are front views for explaining the retreat position PL and the paper feed position PF of the push-up plate 36, respectively. As shown in FIG. 2, the paper feed unit 30 mainly includes a paper feed roller 32, a placement unit 35, a push-up plate 36, and a swinging unit 40.

  The paper feed roller 32 rotates in accordance with the driving force from the motor 47 (see FIG. 6), so that a plurality of recording materials P placed on the placement portion 35 are formed on the forming portion 10 (more specifically, photosensitive). Paper is fed to a transfer position PT (see FIG. 1) sandwiched between the body drum 13 and the transfer roller 18. The separation unit 33 is provided to face the paper feed roller 32 and separates a plurality of recording materials P fed by the paper feed roller 32 one by one.

  The placement unit 35 places a plurality of recording materials P as shown in FIG. The push-up plate 36 is provided with a driving force from a motor 47, so that a feeding position PF (see FIG. 8) for feeding the recording material P to the forming unit 10 side, and a retracting position separated from the feeding roller 32. It swings between PL (see FIG. 7 described later).

  The swinging unit 40 swings the push-up plate 36 up and down by rotating around the rotating shaft 40 a according to the driving force from the motor 47. As shown in FIGS. 2 and 5, the swinging portion 40 mainly includes a one-rotation clutch 41, a plurality of cams 42 (42 a and 42 b), a movable portion 44, a locking portion 45, a solenoid 46, have.

  The one-rotation clutch 41 is a mechanical element that switches between transmission and interruption of driving force for each rotation. As shown in FIG. 2, it has the load side gear 41a and the continuous rotation gear 41b. For example, as shown in FIG. 5, a missing portion 41 c having no teeth is formed on the outer periphery of the load side gear 41 a.

  The locking portion 45 swings around the rotation shaft 45a in accordance with the rotational movement of the load side gear 41a and the forward / backward movement of the solenoid 46. Specifically, one end of the locking portion 45 moves along the original node portion 41d formed near the center of the load side gear 41a. The other end of the locking portion 45 is in contact with the plunger 46a of the solenoid 46 and is biased by the biasing member 46b.

  Therefore, when the original node portion 41d is engaged with the locking portion 45, the driving force from the motor 47 is interrupted in the one-rotation clutch 41, and the rotation of the cam 42 is stopped. Further, after the driving force is interrupted, the plunger 46a of the solenoid 46 is retracted, so that the engagement between the original node portion 41d and the locking portion 45 is released, and the driving force from the motor 47 is transmitted to the rotating shaft 40a. .

  As shown in FIG. 2, the cam 42 (42 a, 42 b) converts the rotary motion transmitted to the rotary shafts 40 a, 40 b into a swing motion of the push-up plate 36. Docking gears 43a and 43b are formed on the outer circumferences of the cams 42a and 42b, respectively.

  As shown in FIG. 2, the movable portion 44 is a cylindrical pressing member provided near the center in the longitudinal direction of the movable shaft 44a. The movable shaft 44a is parallel to the rotary shaft 40a, and both ends of the movable shaft 44a are rotatably provided on the corresponding cams 42 (42a, 42b). Therefore, the movable portion 44 is rotatable with respect to the cam 42 (42a, 42b) around the movable shaft 44a.

  In addition, as shown in FIG. 2, the movable shaft 44a is provided apart from the rotating shaft 40a. As a result, when the cam 42 (42a, 42b) rotates, the movable portion 44 is eccentric according to the rotation operation around the rotation shaft 40a, and comes into contact with the plurality of recording materials P placed on the placement portion 35.

  For example, when the movable shaft 44 a is positioned below the rotation shaft 40 a, the movable portion 44 contacts the recording material P placed on the placement portion 35. As a result, the push-up plate 36 is swung downward.

  Here, the power transmission system in the paper feeding unit 30 will be described. The drive gear 47 a is attached to the shaft center of the motor 47. As shown in FIG. 6, the drive gear 47a is meshed with each of the load side gear 41a and the continuous rotation gear 41b of the one-rotation clutch 41.

  As shown in FIG. 6, the load side gear 41a and the continuous rotation gear 41b of the one-rotation clutch 41 and the docking gear 43a of the cam 42a are attached to the same rotation shaft 40a. The docking gears 38a and 38b are attached to one end and the other end of the rotation shaft 32a of the paper feed roller 32, respectively. Furthermore, the docking gear 43b of the cam 42b is attached to the rotating shaft 40b. The docking gear 38a meshes with the docking gear 43a, and the docking gear 38b meshes with the docking gear 43b.

  Therefore, the driving force from the motor 47 is transmitted to the load side gear 41a and the continuous rotation gear 41b, and the cam 42a is rotated by rotating the rotating shaft 40a. Further, when the driving force is transmitted from the docking gear 43a to the docking gear 38a and the rotating shaft 32a is rotated, the driving force is transmitted from the docking gear 38b to the docking gear 43b and the rotating shaft 40b is rotated. The cam 42b is rotated.

  That is, the driving force from the motor 47 is transmitted to the paper feed roller 32 via the swinging portion 40 and the docking gear 38a attached to the rotating shaft 32a. Therefore, the rotation of the swinging portion 40 (more specifically, the cam 42 (42a, 42b)) and the rotation of the paper feed roller 32 can be easily synchronized.

  The movable portion 44 is attached to a movable shaft 44a, and the movable shaft 44a is rotatable with respect to the cam 42 (42a, 42b).

  Here, in the present embodiment, the driving force from the motor 47 is applied, and the feed roller 32 is placed on the placement unit 35 while the cam 42 (42a, 42b) of the swinging unit 40 rotates once. Among the plurality of recording materials P, the uppermost recording material (hereinafter also simply referred to as “target recording material”) is fed by a unit feed amount. As a result, by the same driving force applied from the same motor 47, the feeding of the unit feed amount by the paper feed roller 32 and the swinging of the push-up plate 36 by the swinging unit 40 are executed simultaneously. That is, the single motor 47 can realize the paper feeding operation of the paper feeding roller 32 and the swinging motion of the push-up plate 36.

  In the present embodiment, the unit feed amount is the transport path Ra between the transfer position PT (see FIG. 1) of the photosensitive drum 13 and the transfer roller 18 and the paper feed position PF (see FIG. 8). It is set to be larger than the distance along.

  As described above, in the present embodiment, it is not necessary to prepare a plurality of motors corresponding to each of the paper feed roller 32 and the swinging unit 40, and a separate registration roller is provided for transporting the recording material P. There is no need. Therefore, the number of parts required for the paper feeding operation can be reduced, and the manufacturing cost of the entire apparatus can be reduced.

<3. Operation of paper feed unit during paper feed>
FIG. 9 and FIG. 10 are front views for explaining the operation of the sheet feeding unit 30 during sheet feeding. Here, the feeding operation of the recording material P will be described with reference to FIGS. It should be noted that at a point before the recording material P is fed (see FIG. 7), one end of the locking portion 45 is engaged with the original joint portion 41d (see FIG. 5), and the push-up plate 36 is It stops at the retreat position PL (see FIG. 7).

  First, when the plunger 46a of the solenoid 46 is retracted, the engagement between the original node portion 41d of the load side gear 41a and the locking portion 45 is released, and the driving force from the motor 47 is transmitted to the rotating shaft 40a.

  Thus, when the cam 42 (42a, 42b) is rotated, the movable portion 44 moves upward, and the movable portion 44 is separated from the recording material P. When the push-up plate 36 is urged upward by the urging member 36b, the push-up plate 36 is swung upward and moved to the paper feed position PF (see FIG. 8). Therefore, the plurality of recording materials P can be fed one by one by the paper feed roller 32 and the separation unit 33.

  Subsequently, when the cam 42 (42a, 42b) is further rotated, the movable portion 44 comes into contact with the recording material P again (see FIG. 9). As a result, the push-up plate 36 is swung downward. When the cam 42 (42a, 42b) makes one rotation, the push-up plate 36 reaches the retracted position PL again (FIG. 10). Thus, while the cam 42 (42a, 42b) of the swinging portion 40 makes one rotation, the push-up plate 36 moves from the retracted position PL (see FIG. 7) to the paper feeding position PF (see FIGS. 8 and 9). Moved. As a result, the pressed recording material is brought into contact with the paper feed roller 32 and fed to the forming unit 10 side.

  Further, while the cam 42 (42a, 42b) of the swinging portion 40 makes one rotation, the push-up plate 36 is moved from the paper feed position PF to the retreat position PL. As a result, among the plurality of recording materials P placed on the placement unit 35, those other than the recording material of interest are separated from the paper feed roller 32. As described above, the image forming apparatus 1 can easily feed the recording material of interest to the forming unit 10 side by one rotation of the swinging unit 40.

<4. Advantages of Image Forming Apparatus in Present Embodiment>
As described above, in the image forming apparatus 1 according to the present embodiment, the push-up plate 36 is urged by the urging member 36b, and among the plurality of recording materials P, the height position of the uppermost recording material of interest. Is regulated by the movable portion 44. Accordingly, the height position of the recording material of interest is always constant regardless of the number of recording materials P placed on the placement portion 35. Therefore, the push-up plate 36 can bring the recording material of interest into contact with the paper feed roller 32 at a constant timing regardless of the number of recording materials P placed on the placement portion 35, and at a constant timing. The recording material of interest can be fed to the forming unit 10 side.

  In the image forming apparatus 1 of the present embodiment, the movable portion 44 is rotatable around a movable shaft 44a that is parallel to the rotation shafts 40a and 40b of the swinging portion 40. Thereby, even when the swinging portion 40 rotates and the movable portion 44 is eccentric, the movable portion 44 can press each recording material P without damaging each recording material P. Therefore, the movable part 44 can swing the push-up plate 36 satisfactorily.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 10 Forming part 13 Photosensitive drum 18 Transfer roller 19 Exposure part 20 Fixing part 30 Paper feeding part 32 Paper feeding roller 32a Rotating shaft 33 Separating part 35 Mounting part 36 Push-up board 36b, 46b Energizing member 40 Oscillation Sections 40a, 40b, 45a Rotating shaft 44 Movable section 44 Movable shaft 47 Motor 50 Paper discharge section 90 Control section P Recording material PF Paper feed position PL Retraction position PT Transfer position

Claims (3)

(a) a placement unit for placing a plurality of recording materials;
(b) by rotating according to driving force from a drive source, a paper feeding roller for feeding the paper to the top layer of the target recording material of the plurality of recording materials placed on the mounting section,
(c) a push-up plate that can swing so as to approach or move away from the paper feed roller ;
(d) a biasing member that constantly applies a force in a direction approaching the paper feed roller to the push-up plate;
(E) in accordance with the driving force from the driving source, and a rocking portion you rotate about a rotation axis,
With
The rocking part is
( e- 1) provided in parallel with the rotation axis and spaced apart from the rotation axis, and in contact with the upper surface of the recording material of interest according to a rotation operation around the rotation axis, A movable part that swings the push-up plate through the recording material of
An image forming apparatus comprising: The image forming apparatus according to claim 1.
The image forming apparatus, wherein the movable portion is rotatable about a movable axis parallel to the rotation axis. The image forming apparatus according to claim 1, wherein:
While the swinging portion makes one rotation by applying the driving force,
The paper feed roller, an image forming apparatus, characterized by feeding the paper to the attention recording material.

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