JP2020154164A - Image formation apparatus - Google Patents

Abstract

To suppress the attachment/detachment failure of a unit in an image formation apparatus having the unit attachable/detachable to/from an apparatus body.SOLUTION: An image formation apparatus 1 comprises: a development cartridge 51 which has a first lever 55; a second lever 91 which has a first boss 913; a spring 92; and a drive gear 93 which has at an eccentric position a second boss 932 contacting the first boss 913 against the biasing force of the spring 92. The second lever 91 can oscillate between the first position for pressing the first lever 55 and the second position where the second boss 932 contacts the first boss 913 with the rotation of the drive gear 93 to make the development cartridge 51 attachable/detachable. When the development cartridge 51 is displaced in the taking-out direction in a case of being at the first position for pressing the first lever 55, the second lever oscillates toward the second position against the biasing force of the spring 92 by being pressed by the first lever 55.SELECTED DRAWING: Figure 5

Description

The present invention relates to an image forming apparatus including a unit that can be attached to and detached from the apparatus main body.

Conventionally, an image forming apparatus has been known in which a developing cartridge containing a developing agent is detachably attached. Normally, the developing cartridge is provided with a stirring member for stirring the developer, and the stirring member is driven by a driving force from the main body of the apparatus. For example, Patent Document 1 discloses a configuration in which a lever for controlling the drive of a stirring member is provided in a developing cartridge, and the stirring member is driven by pushing this lever with a lever on the device main body side.

Japanese Unexamined Patent Publication No. 2017-181949

However, according to the configuration of Patent Document 1, when the lever on the device main body side is stopped while pushing the lever on the developing cartridge side due to a power failure or the like, the lever of the developing cartridge moves to the lever on the device main body side in the direction of pulling out the developing cartridge. It gets caught in the lever and cannot be pulled out.

Such attachment / detachment failure in the image forming apparatus may occur not only in the developing cartridge but also in the case of a detachable unit such as a sheet cassette.

An object of the present invention is to suppress an obstacle of attachment / detachment of a unit in an image forming apparatus including a unit that can be attached / detached to the main body of the apparatus.

The image forming apparatus (1) of the present invention includes an apparatus main body (2) and a unit (51) having a first lever (55) that is detachably attached to the apparatus main body (2) and is swingable. The first lever (55) of the unit (51) provided on the apparatus main body (2) so as to be swingable about the rotation axis (R) can be pressed, and the rotation can be performed. A second lever (91) having a first boss (913) protruding in the axial center (R) direction, and the second lever (91) in a direction in which the second lever (91) presses the first lever (55). A spring (92) that urges the spring (91) and a second boss that is rotatably provided on the device body (2) and comes into contact with the first boss (913) against the urging force of the spring (92). A first position including a drive gear (93) having (932) in an eccentric position, the second lever (91) being urged by the spring (92) to press the first lever (55). Then, when the drive gear (93) rotates, the second boss (932) comes into contact with the first boss (913) and retracts from the first lever (55) so that the unit (51) can be attached and detached. When the unit (51) is displaced in the direction in which the unit (51) is taken out when it is in the first position where the first lever (55) is pressed, the first lever (55) can be swung with the second position. It is characterized in that it is pushed by the lever (55) and swings toward the second position against the urging force of the spring (92).

According to the present invention, when the unit is pulled out while the second lever is pressing the first lever, the first lever pushes the second lever and the first boss separates from the second boss. 2 The lever swings toward the second position. Therefore, it is possible to prevent the first lever from being caught by the second lever and obstructing the attachment / detachment of the unit.

It is a central sectional view of the image forming apparatus of one Embodiment. It is an enlarged right side view around the 2nd lever when the 2nd lever is in the 1st position. It is an enlarged right side view around the 2nd lever when the 2nd lever is in the 2nd position. It is a perspective view of the 2nd lever. It is an enlarged right side view which shows the 2nd lever, the drive gear, and a spring when the 2nd lever is in the 1st position. It is a front view of FIG. FIG. 5 is a diagram showing a state in which the second lever is displaced to the second position in FIG. FIG. 5 is a diagram showing a state in which the second lever is displaced to the third position in FIG.

[Overall configuration of image forming apparatus]
FIG. 1 is a central sectional view of the image forming apparatus 1 according to the embodiment of the present invention. In the following description, based on the state in which the image forming apparatus 1 is usably installed as shown in FIG. 1, the side from which the sheet cassette 10 is pulled out is the front, the opposite side is the rear, and the image forming apparatus 1 is the front side. The left-right direction is defined when viewed from the viewpoint, and each direction is defined with the discharge tray 82 side of the image forming apparatus 1 facing up and the opposite side facing down.

The image forming apparatus 1 includes an apparatus main body 2, a supply unit 3, a motor 4, an image forming unit 5, and a discharging unit 8.

The apparatus main body 2 includes a frame that supports each component of the image forming apparatus 1 and an exterior cover that constitutes the appearance of the image forming apparatus 1. A storage portion 2A for storing the seat cassette 10 is formed in the lower part of the apparatus main body 2. The supply unit 3 is arranged in the lower part of the image forming apparatus 1 and conveys the sheet S to the image forming unit 5.

The image forming unit 5 is arranged on the downstream side of the sheet S in the transport direction with respect to the supply unit 3, and forms an image on the sheet S transported from the supply unit 3. The discharge unit 8 is arranged downstream of the image forming unit 5 in the transport direction of the sheet S, and discharges and supports the sheet S on which the image is formed by the image forming unit 5 to the outside of the image forming apparatus 1. ..

The supply unit 3 includes a sheet cassette 10, a supply mechanism 20, a transfer roller 24, and a resist roller 25.

The seat cassette 10 is configured to be slidable in the front-rear direction between a storage position stored in the storage unit 2A of the apparatus main body 2 and a drawer position drawn from the storage unit 2A. The sheet cassette 10 includes a cassette body 11 capable of accommodating a plurality of sheets S, a pressure plate 12 arranged on the cassette body 11 to support the sheet S so as to be displaceable in the vertical direction, and a pressure plate raising member 13 for raising the pressure plate 12. Has. The pressure plate raising member 13 is driven by the motor 4. FIG. 1 shows a state in which the pressure plate 12 is lifted by the lift of the pressure plate raising member 13, and the sheet S loaded on the pressure plate 12 is raised to a supplyable position.

The supply mechanism 20 is a mechanism that separates and takes out the sheets S loaded on the sheet cassette 10 one by one and conveys them toward the transfer roller 24. The supply mechanism 20 includes a pickup roller 21, a separation roller 22, and a separation pad 23.

The pickup roller 21 is a roller for taking out the sheet S raised to a supplyable position by the pressure plate 12, and is arranged above the pressure plate 12. The separation roller 22 is arranged on the downstream side of the seat S in the transport direction with respect to the pickup roller 21, and the separation pad 23 is arranged to face the separation roller 22 and is urged toward the separation roller 22.

The sheet S taken out by the pickup roller 21 is sent out to the separation roller 22 side, is separated one by one between the separation roller 22 and the separation pad 23, and is conveyed toward the transfer roller 24.

The transfer roller 24 is a roller that applies a transfer force to the sheet S, and is arranged on the downstream side of the sheet S in the transfer direction with respect to the supply mechanism 20. The sheet S conveyed from the supply mechanism 20 toward the transfer roller 24 is conveyed toward the resist roller 25.

The resist roller 25 is arranged on the downstream side of the sheet S in the transport direction with respect to the transport roller 24. The resist roller 25 regulates the movement of the tip of the sheet S to be transported, temporarily stops the movement, and then transports the sheet S toward the transfer position at a predetermined timing.

The image forming unit 5 is composed of a process unit 50 that transfers an image to the surface of the sheet S conveyed from the supply unit 3, an exposure unit 60 that exposes the surface of the photoconductor drum 56 of the process unit 50, and the process unit 50. A fixing unit 70 for fixing the image transferred to the sheet S is provided.

The process unit 50 is arranged above the storage position of the seat cassette 10 in the apparatus main body 2. The process unit 50 includes a developing cartridge 51 as an example of the unit, a photoconductor drum 56, and a transfer roller 57. The developing cartridge 51 includes a developer accommodating chamber 52, a supply roller 53, a developing roller 54, and a first lever 55. The photoconductor drum 56 may be provided on the developing cartridge 51. The developing cartridge 51 is removable from the device main body 2, and is between the mounting position (position shown in FIG. 1) housed and mounted in the device main body 2 and the taking-out position taken out from the device main body 2. It is configured to be slidable along the front-back direction.

Toner serving as a developer is stored in the developer storage chamber 52. The toner stored in the developer storage chamber 52 is sent to the supply roller 53 while being stirred by the stirring member 521. The supply roller 53 further supplies the toner sent from the developer accommodating chamber 52 to the developing roller 54. The developing roller 54 is arranged in close contact with the supply roller 53, and carries toner supplied from the supply roller 53 and charged by a sliding contact member (not shown).

The first lever 55 is a lever that controls the drive of the stirring member 521, and has a known configuration similar to that of the lever 50 of JP-A-2017-181949. The first lever 55 is provided on the left side surface of the developing cartridge 51 so as to be swingable in the front-rear direction. The stirring member 521 is driven when tilted to the state shown in FIG. 2, and the stirring member 521 is driven to the state shown in FIG. Is configured to stop. The swinging tip of the first lever 55 projects upward from the developing cartridge 51 and can be pressed by the second lever 91 provided on the apparatus main body 2.

The photoconductor drum 56 is arranged adjacent to the developing roller 54. The surface of the photoconductor drum 56 is uniformly charged by a charger (not shown) and then exposed by the exposure unit 60. The exposed portion of the photoconductor drum 56 has a lower potential than the other portions, and an electrostatic latent image based on the image data is formed on the photoconductor drum 56. Then, the charged toner is supplied from the developing roller 54 to the surface of the photoconductor drum 56 on which the electrostatic latent image is formed, so that the electrostatic latent image is visualized and becomes a developer image.

The transfer roller 57 is arranged to face the photoconductor drum 56. With the transfer bias applied to the surface of the transfer roller 57, the sheet S is conveyed between the photoconductor drum 56 on which the developer image is formed and the transfer roller 57 (transfer position) without sandwiching the sheet S. The developer image formed on the surface of the photoconductor drum 56 is transferred to the surface of the sheet S.

The exposure unit 60 includes a laser diode, a polygon mirror, a lens, and a reflecting mirror, and irradiates the photoconductor drum 56 with a laser beam based on the image data input to the image forming apparatus 1. The surface of the photoconductor drum 56 is exposed.

The fixing unit 70 includes a heating roller 71 and a pressing roller 72. The heating roller 71 is rotationally driven by a driving force from the motor 4, and the heating roller 71 is heated by supplying electric power from a power source (not shown). The pressing roller 72 is arranged to face the heating roller 71, and is brought into close contact with the heating roller 71 to rotate in a driven manner. When the sheet S on which the developer image is transferred is conveyed to the fixing unit 70, the sheet S is conveyed while being sandwiched between the heating roller 71 and the pressing roller 72, and the developer image is fixed on the sheet S.

The discharge unit 8 includes a discharge roller 81 and a discharge tray 82. The discharge roller 81 is a pair of rollers, and discharges the sheet S conveyed from the fixing unit 70 toward the outside of the apparatus main body 2. The sheet S discharged to the outside of the apparatus main body 2 by the discharge roller 81 is deposited on the discharge tray 82.

In such an image forming apparatus 1, assuming that the power is suddenly turned off due to a power failure or the like, the second lever 91 on the device main body 2 side may stop while pressing the first lever 55 on the developing cartridge 51 side. is there. At this time, in order to avoid an attachment / detachment failure in which the first lever 55 is caught by the second lever 91 and the developing cartridge 51 cannot be pulled out, the configuration is as follows.

[Configuration to avoid attachment / detachment obstacles]
First, the normal operation of the first lever 55 and the second lever 91 will be described. FIG. 2 is an enlarged right side view of the periphery of the second lever 91 when the second lever 91 is in the first position. FIG. 3 is an enlarged right side view of the periphery of the second lever 91 when the second lever 91 is in the second position.

The second lever 91 is provided on the apparatus main body 2 so as to be swingable around a rotation axis R extending in the left-right direction. The second lever 91 is driven by the motor 4 and retracts from the first lever 55 to attach / detach the developing cartridge 51 to and from the first position (position shown in FIG. 2) for pressing the first lever 55 of the mounted developing cartridge 51. It can swing with a second position (position shown in FIG. 3) that enables it.

The second lever 91 at the first position is in a state in which the contact portion 91A that abuts on the first lever 55 is located below the rotation axis R. At this time, in the developing cartridge 51 in the mounting position, the first lever 55 is pressed backward by the second lever 91 and swings to a transmission position where the driving force from the motor 4 is transmitted to the stirring member 521.

On the other hand, the second lever 91 at the second position is in a state where the contact portion 91A is located in front of the rotation axis R and retracts from the first lever 55. At this time, in the developing cartridge 51 in the mounting position, the first lever 55 swings along the vertical direction as shown in FIG. 3 to a cutting position that cuts the driving force from the motor 4 to the stirring member 521. As a result, the developing cartridge 51 can be pulled out forward without the first lever 55 being caught by the second lever 91.

Next, a configuration for allowing the development cartridge 51 to be pulled out in the state of FIG. 2 will be described. FIG. 4 is a perspective view of the second lever 91. FIG. 5 is an enlarged right side view showing the second lever 91, the drive gear 93, and the spring 92 when the second lever 91 is in the first position, and FIG. 6 is a front view thereof. FIG. 7 is a diagram showing a state in which the second lever 91 is displaced to the second position in FIG. FIG. 8 is a diagram showing a state in which the second lever 91 is displaced to the third position in FIG.

As shown in FIG. 4, the second lever 91 has a shaft portion 911, a lever portion 912, and a first boss 913. The shaft portion 911 is a cylindrical member extending in the left-right direction, and is rotatably fitted on a rod-shaped support portion 2B (see FIG. 6) provided in the apparatus main body 2 so as to be centered on a rotation axis R. .. The lever portion 912 is a square columnar member extending in the radial direction from the outer peripheral surface of the shaft portion 911, and the tip portion thereof serves as a contact portion 91A that abuts on the first lever 55.

The first boss 913 is a columnar member extending to the left along the rotation axis R from the vicinity of the shaft portion 911 on the left surface of the lever portion 912, and the tip portion thereof is to the left of the left surface of the shaft portion 911. It is protruding. As shown in FIG. 5, the second lever 91 is configured such that the distance L1 from the rotation axis R to the first boss 913 is shorter than the distance L2 from the rotation axis R to the contact portion 91A. As a result, when the second lever 91 swings around the rotation axis R, the displacement amount of the first boss 913 is smaller than the displacement amount of the contact portion 91A, so that the second lever 91 can be miniaturized. ..

As shown in FIGS. 5 and 6, a spring 92 is arranged on the right side of the second lever 91, and a drive gear 93 is arranged on the left side of the second lever 91. By arranging the drive gear 93, the second lever 91, and the spring 92 in this order along the rotation axis R direction of the second lever 91, each member is assembled from one direction along the rotation axis R direction. It can be done and workability is good. In the present embodiment, the spring 92, the second lever 91, and the drive gear 93 can be assembled to the device main body 2 in this order from left to right.

The spring 92 is a torsion coil spring, and the coil portion 92A fits externally into the support portion 2B of the apparatus main body 2, and one end portion 92B engages with the side surface of the lever portion 912 of the second lever 91 opposite to the contact portion 91A. The other end 92C is engaged with the device main body 2. As a result, the spring 92 urges the second lever 91 in the rear direction in FIG. That is, the spring 92 urges the second lever 92 in the direction in which the second lever 91 presses the first lever 55.

The spring 92 is not limited to the torsion coil spring, and may be any spring that urges the second lever 92 in the direction in which the second lever 91 presses the first lever 55, and the compression coil spring, the tension coil spring, and the like. It may be a leaf spring or the like.

The drive gear 93 is a sector gear that is rotatably provided on the main body 2 of the apparatus so as to overlap the second lever 91 in the left-right direction, and is rotated by the motor 4 to drive the second lever 91. The drive gear 93 has a shaft portion 931, a second boss 932, and a regulation portion 933 inside the tooth bottom circle. The shaft portion 931 is a columnar member extending in the left-right direction, and is rotatably supported by a hole portion (not shown) provided in the apparatus main body 2.

The second boss 932 is a columnar member extending to the right about the eccentric position on the right surface of the drive gear 93. In the present embodiment, the second boss 932 is formed at a position including the shaft portion 931. The first boss 913 is in contact with the second boss 932 due to the urging force of the spring 92. Therefore, when the drive gear 93 rotates in the rotation direction A, the second boss 932 rotates about the shaft portion 931 while pushing the first boss 913 against the urging force of the spring 92. At this time, the displacement of the first boss 913 causes the second lever 91 to swing between the first position (position shown in FIG. 5) and the second position (position shown in FIG. 7).

Further, there is a space formed between the second boss 932 and the regulating portion 933. With this space as the evacuation area, the first boss 913 can be displaced away from the second boss 932. That is, when the second lever 91 is stopped at the first position pressing the first lever 55 due to a power failure or the like and is displaced in the direction in which the developing cartridge 51 is taken out, the second lever 91 becomes the first lever 55. It is pushed by the force and can swing toward the second position against the urging force of the spring 92. Therefore, it is possible to avoid an attachment / detachment failure in which the first lever 55 is caught by the second lever 91 and the developing cartridge 51 cannot be pulled out.

Further, in the present embodiment, since the second boss 932 has a cylindrical shape, the second lever 91 can be swung smoothly as compared with the case where the second boss 932 has a prismatic shape. If the smooth operation of the second boss 932 is not required, the second boss 932 may have a prismatic shape.

The regulation portion 933 is a ring-shaped member that surrounds the second boss 932 so as to form a groove portion 934 with the second boss 932. In the present embodiment, the groove portion 934 is formed by digging the inside of the tooth bottom circle of the drive gear 93, the inner wall surface of the groove portion 934 is the second boss 932, and the outer wall surface of the groove portion 934 is the regulation portion 933. That is, the regulation portion 933 has a circular shape centered on the shaft portion 931 when viewed from the right.

When the second lever 91 at the first position is pushed by the first lever 55 and the second lever 91 swings to the third position (position shown in FIG. 8) beyond the second position, the regulation unit 933 is operated. , It comes into contact with the first boss 913 and regulates the swing of the second lever 91. By restricting the second lever 91 from swinging beyond the third position, damage to members such as the second lever 91 and the spring 92 can be suppressed.

The groove portion 934 has a shape whose width changes along the rotation direction A of the drive gear 93. As a result, the regulation unit 933 can regulate the second lever 91 so as not to swing beyond the third position regardless of the rotation position of the drive gear 93. Therefore, the regulation unit 933 can regulate the unintended swing even when the second lever 91 is located at a position other than the first position. For example, when the second lever 91 is in the second position, the second lever 91 can swing up to the third position, but cannot swing beyond the third position. The regulatory unit 933 is not an essential configuration.

The configuration for avoiding the attachment / detachment failure can be applied not only to the developing cartridge 51 but also to any detachable unit in the image forming apparatus 1 such as the sheet cassette 10.

[Effect of Embodiment]
The image forming apparatus 1 includes an apparatus main body 2 and a developing cartridge 51 which is detachably attached to the apparatus main body 2 and has a swingable first lever 55. Further, the image forming apparatus 1 is provided on the apparatus main body 2 so as to be swingable around the rotation axis R, and can press the first lever 55 of the mounted development cartridge 51 in the rotation axis R direction. A second lever 91 having a protruding first boss 913 is provided. Further, the image forming apparatus 1 is provided with a spring 92 that urges the second lever 91 in the direction in which the second lever 91 presses the first lever 55, and a rotatably provided device main body 2 to resist the urging force of the spring 92. A drive gear 93 having a second boss 932 in an eccentric position that comes into contact with the first boss 913 is provided. The second lever 91 is urged by the spring 92 to press the first lever 55, and the second boss 932 comes into contact with the first boss 913 as the drive gear 93 rotates. It is swingable from the second position that retracts from the lever 55 and allows the development cartridge 51 to be attached and detached, and is in the direction in which the development cartridge 51 is taken out when it is in the first position where the first lever 55 is pressed. When it is displaced, it is pushed by the first lever 55 and swings toward the second position against the urging force of the spring 92.

According to this configuration, when the developing cartridge 51 is pulled out while the second lever 91 is pressing the first lever 55, the first lever 55 pushes the second lever 91 and the first boss 913 is second. By moving away from the boss 932, the second lever 91 swings toward the second position. Therefore, it is possible to prevent the first lever 55 from being caught by the second lever 91 and obstructing the attachment / detachment of the developing cartridge 51.

Further, according to the above-mentioned image forming apparatus 1, in the drive gear 93, the second lever 91 at the first position is pushed by the first lever 55, and the second lever 91 swings to the third position beyond the second position. It has a regulating unit 933 that comes into contact with the first boss 913 and regulates the swing of the second lever 91 when it is moved.

According to this configuration, damage to each member can be suppressed by restricting the second lever 91 from swinging beyond the third position.

Further, according to the image forming apparatus 1, the regulating portion 933 has a ring shape surrounding the second boss 932 so as to form a groove portion 934 between the regulating portion 933 and the second boss 932. The groove portion 934 has a shape whose width changes along the rotation direction of the drive gear 93.

According to this configuration, the regulation unit 933 can regulate the unintended swing of the second lever 91 other than the first position.

Further, according to the image forming apparatus 1, the second lever 91 reaches the contact portion 91A where the distance L1 from the rotation axis R to the first boss 913 comes into contact with the first lever 55 from the rotation axis R. It is configured to be shorter than the distance L2 of.

According to this configuration, when the second lever 91 swings, the displacement amount of the first boss 913 is smaller than the displacement amount of the contact portion 91A, so that the second lever 91 can be miniaturized.

Further, according to the image forming apparatus 1, the drive gear 93, the second lever 91, and the spring 92 are arranged in this order along the rotation axis R direction of the second lever 91.

According to this configuration, each member can be assembled from one direction along the rotation axis R direction, and workability is good.

Further, according to the above-mentioned image forming apparatus 1, the second boss 932 has a cylindrical shape.

According to this configuration, the second lever 91 can be swung smoothly as compared with the case where the second boss 932 has a prismatic shape.

1 Image forming device 2 Device body 51 Development cartridge 55 1st lever 91 2nd lever 91A Contact part 92 Spring 93 Drive gear 913 1st boss 932 2nd boss 933 Restriction part 934 Groove part L1 From rotation axis to 1st boss Distance L2 Distance from the center of rotation to the contact part R Center of rotation

Claims (7)

With the device body
A unit that is detachably attached to the main body of the device and has a swingable first lever, and
A second boss that is provided on the main body of the device so as to be swingable around the center of rotation, can press the first lever of the mounted unit, and has a first boss protruding in the direction of the center of rotation. With the lever
A spring that urges the second lever in a direction in which the second lever presses the first lever.
A drive gear that is rotatably provided on the main body of the device and has a second boss in an eccentric position that comes into contact with the first boss against the urging force of the spring.
The second lever is urged by the spring to press the first lever, and the second lever comes into contact with the first boss due to rotation of the drive gear. When the unit is displaced in the direction in which the unit is taken out when it is in the first position where the first lever is pressed, the unit can be swung from the second position where the unit can be attached and detached. An image forming apparatus characterized in that it is pushed by a first lever and swings toward the second position against the urging force of the spring. The drive gear has the first boss when the second lever at the first position is pushed by the first lever and the second lever swings to a third position beyond the second position. The image forming apparatus according to claim 1, further comprising a regulating portion that abuts against and regulates the swing of the second lever. The restricting portion has a ring shape surrounding the second boss so as to form a groove portion with the second boss.
The image forming apparatus according to claim 2, wherein the groove portion has a shape whose width changes along the rotation direction of the drive gear. The second lever is characterized in that the distance from the rotation axis to the first boss is shorter than the distance from the rotation axis to the abutting portion that abuts on the first lever. The image forming apparatus according to any one of claims 1 to 3. The invention according to any one of claims 1 to 4, wherein the drive gear, the second lever, and the spring are arranged in this order along the direction of the rotation axis of the second lever. Image forming device. The image forming apparatus according to any one of claims 1 to 5, wherein the second boss has a cylindrical shape. The unit is a developing cartridge that houses a developing agent.
The image forming apparatus according to any one of claims 1 to 6, wherein the first lever is a lever that controls driving of a stirring member that stirs the developer.

Images