JPH09325667A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable stable power feeding and attachment fixing, without increasing the number of parts, while keeping the exchange operability of process cartridges. SOLUTION: Force for obtaining a movement in a thrusting direction (d) is exerted on the unit case 35 of a process unit by a helical gear 40 on a driven side and a helical gear on a driving side which is engaged with the helical gear 40, at the time of transmitting driving force. Then, the rotary shaft 6a of a photoreceptor drum 6 can be moved in a direction where a power feeding terminal 52 on the side of a printer main body 1 is installed, together with the unit case 35. By such a constitution, at the time of transmitting the driving force, the rotary shaft 6a as a ground terminal part of the photoreceptor drum 6 comes into elastic contact with the feeding terminal 52, so as to encroach thereon by a fixed amount, to maintain an electrically connected state with stable contact pressure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to a facsimile apparatus, a scanner apparatus, a copying machine, etc., and a process cartridge composed of electrostatic image forming process constituent members such as a photoconductor and a developing roller can be attached to and detached from the apparatus main body. The present invention relates to an image forming apparatus mounted on the.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus equipped with an electrostatic image forming section, a process cartridge incorporating a photosensitive member, a developing roller, etc., which are components of an electrostatic image forming process, is installed in the main body of the image forming apparatus. Some of them are detachably attached. In the image forming apparatus using the process cartridge, the rotational driving force is transmitted from the drive source to the photoconductor and the developing roller, and further provided in a part of the process cartridge and the apparatus main body in a state of being attached to the apparatus main body. Some of them are adapted to be electrically connected to the supplied power supply means. Then, various configurations for ensuring this electrical connection have been proposed and implemented.

As an example of the structure relating to the electrical connection, for example, as disclosed in Japanese Patent Laid-Open No. 4-320281, a rotatable charging member that contacts a charged body and charges the charged body. By directly supplying power from the axial end surface of the rotating shaft of the rotating shaft, it is possible to prevent the occurrence of charging failure of the charged body due to the conduction failure of the power supply path, or JP-A-2-163761. As described above, by radially arranging the electrical connection means with the apparatus main body side on the side surface of the process cartridge, many contacts can be efficiently arranged, the contact wiring mechanism can be simplified, and the apparatus can be downsized. Some are designed to work.

[0004]

In the above-mentioned conventional technique, the mechanism of the electrical connecting portion is generally as described in Japanese Patent Laid-Open No.
A device for supplying power through a leaf spring or the like as disclosed in Japanese Unexamined Patent Publication No. 320281, or a device for connecting to an electrical connecting means through a coil spring as disclosed in Japanese Patent Laid-Open No. 2-163761.

However, the process cartridge used in the image forming apparatus is usually configured to be replaceable by the user, and may be roughly handled by the user during the replacement work. In such a case, the leaf spring or the coil spring as the terminal may be deformed to cause a conduction failure. In addition, there are some types in which the mounting portion is somewhat loosened due to the detachability of the process cartridge from the apparatus main body or the dimensional accuracy of the mounting portion. If the rattling is such that the terminal is moved in the thrust direction, the contact pressure of the terminal will change due to the replacement work of the process cartridge, and in an extreme case of an unstable contact state. May cause poor continuity.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an image forming apparatus in which stable power supply and stable mounting are performed without increasing the number of parts while maintaining the workability of exchanging the process cartridge. .

[0007]

In order to achieve the above object, the present invention provides a process cartridge comprising an electrostatic image forming process constituent member such as a photosensitive member and a developing roller, which is detachably attached to an apparatus main body. Rotational driving force is transmitted from a driving source to the photoconductor and the developing roller, and a part of the process cartridge and a power supply unit provided in the apparatus body are electrically connected to each other while being mounted in the apparatus body. In the image forming apparatus configured as described above, a driven portion of at least one of the photosensitive member and the developing roller and a driving portion of a driving source are meshed with a helical gear to transmit a rotational driving force, and the driving is further performed. The helical gears are arranged so that a thrust force in a direction of contacting the power supply means with the process cartridge is generated on the process cartridge when the force is transmitted. Is a made by forming a helical,
With this configuration, the thrust force generated when the helical gear rotates can be used as a force for contacting the process cartridge and the power feeding means, and the electrical connection between the power feeding means and the process cartridge is stable and reliable. Become.

Further, according to the present invention, a process cartridge including an electrostatic image forming process constituting member such as a photoconductor and a developing roller is detachably attached to the apparatus main body and is driven with respect to the photoconductor and the developing roller. In the image forming apparatus, the rotational driving force is transmitted from the power source, and further, the process cartridge and the apparatus main body are provided with locking portions for locking each other in a state of being attached to the apparatus main body, The driven portion of at least one of the developing roller and the driving portion of the driving source are meshed with each other by a helical gear to transmit the rotational driving force, and the locking portions are locked to each other when the driving force is transmitted. The helical gear has a helical shape so that a thrust force in the direction of rotation is generated with respect to the process cartridge. The thrust force generated at the time of rolling, it is possible to use the engagement portion of the process cartridge and the apparatus main body as a force for contacting with each other, fixedly mounted in the process cartridge is ensured stable and.

Further, according to the present invention, a process cartridge including an electrostatic image forming process constituent member such as a photoconductor and a developing roller is detachably attached to the apparatus main body and is driven with respect to the photoconductor and the developing roller. The rotational driving force is transmitted from the power source, and a part of the process cartridge is electrically connected to the power feeding means provided in the apparatus main body in a state of being attached to the apparatus main body, and further provided in the process cartridge and the apparatus main body. In an image forming apparatus having a configuration in which a locking portion that locks each other in a state of being mounted on the apparatus main body is provided, a driven portion of at least one of the photoconductor and the developing roller and a driving portion of a driving source are provided. Helical gears are engaged to transmit the rotational driving force, and the process cartridge is brought into contact with the power feeding means when the driving force is transmitted, and The helical gear is formed so that a thrust force for locking the locking portions to each other is generated with respect to the process cartridge. With this configuration, the helical gear is formed. By utilizing the thrust force generated at the time of rotation of the process cartridge as a force for contacting the process cartridge and the power supply means, the electrical connection between the power supply means and the process cartridge becomes stable and reliable, and the thrust force is By utilizing the engaging portion of the cartridge and the main assembly of the apparatus as a force for bringing them into contact with each other, the mounting and fixing of the process cartridge becomes stable and reliable.

Further, according to the present invention, a force dividing unit for branching a part of the thrust force generated in a direction in which the process cartridge is brought into contact with the power feeding means in a direction in which the locking portions are locked with each other is provided in the apparatus main body. Since the thrust force generated in one direction can be branched in the direction of the power feeding means and the direction of the locking portion by the component, the installation position of the power feeding means and the locking portion can be freely set.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic configuration diagram of a laser printer for explaining an embodiment of the present invention, in which 1 is a main body 2.
And a printer body 5 composed of an opening / closing body 4 which is openably / closably supported around a shaft 3 provided on the right side of the main body 2, a photosensitive drum 6, a cleaning portion 7, a toner storage portion 8, A process unit, which is an electrostatic image recording unit that is composed of a developing roller 9 and is detachably provided in a predetermined mounting position of a support frame or the like in the printer main body 1, is a photosensitive drum 6 which receives image data. A laser optical system for exposure, a controller unit 11 for controlling operation of each component, a cooling fan 12, a registration roller 13,
Reference numeral 14 is a paper feed cassette provided in the lower part of the print main body 1 in a detachable manner in the direction of arrow a, 15 is a paper feed roller provided in the upper part of the paper feed cassette 14, and 16 is a part of the paper feed roller 15. Then, a separation pad for feeding the recording papers P stored in the paper feed cassette 14 one by one, and 17 is a registration sensor provided in a recording paper conveyance path between the registration roller 13 and the paper feed roller 15. .

A transfer roller 20 for transferring the toner image on the surface of the photosensitive drum 6 to the recording sheet P conveyed by the registration roller 13 at a timing is provided on the opening / closing body 4.
Fixing device 21 for fixing the toner image on recording paper P after transfer
And a paper ejection roller 22, and a paper ejection sensor 23 provided in a recording paper conveyance path between the fixing device 21 and the paper ejection roller 22 are internally provided. An operation panel 24 for displaying is provided.

At the lower left portion of the opening / closing body 4 of the printer body 1, a small-sized paper feeding cassette 25 is detachably provided,
The recording paper P stored in the paper feed cassette 25 is
A sheet feed roller 26 and a separation pad 27 provided on the shaft 3 are provided to feed the sheets one by one toward the registration roller 13.

The upper side of the main body 2 of the printer body 1 constitutes a paper discharge tray 30 for receiving the recording paper P discharged from the paper discharge roller 22 with the recording surface downward, and a part of the tray is rotated by a shaft 31. A cover body 32 is movably supported, and a discharge receiving stopper 33 is provided on the upper left portion of the main body 2 so that the discharge receiving stopper 33 can be received according to the size of the recording paper P to be discharged. It is provided so as to be movable and removable in the b direction.

The feeding, conveying, or image forming operation of the recording paper P in the printer having the above-mentioned structure is well known, and therefore its detailed description is omitted.

FIG. 2 is a perspective view showing an essential part of the process unit 5, and FIG. 3 is a plan view of the essential part. Each end of the rotary shaft 6a of the photosensitive drum 6 and the rotary shaft 9a of the developing roller 9 is shown. Are rotatably supported by bearings of a unit case 35 that houses and holds the constituent members of the process unit 5. Further, the end portions of the rotary shafts 6a and 9a, that is, the driven portions, are mounted on the bearings. For example, gears 40 and 41 are fixed. The rotary shaft 6a of the photoconductor drum 6 is made of metal and also has a function of grounding the photoconductor drum 6.

The helical gears 40, 41 are meshed with helical gears 44, 45 as a drive unit that receives the rotational driving force of the drive motor 42 via a drive transmission means such as a timing belt 43, and drives When transmitting the force, the photosensitive drum 6 is rotated in the direction of arrow c, and the developing roller 9 is rotated in the direction of arrow e. By using the helical gears 40, 41, 44, 45, the meshing ratio between the gears is increased, so that uneven rotation can be suppressed and the driving efficiency is improved.

Alternatively, the helical gears 44 and 45 have a helical structure in which the unit case 35 of the process unit 5 which is detachably attached to the printer body 1 is thrust in the driving direction (arrow d direction). It is formed so as to generate a force to move it. Further, the unit case 35 is provided with a regulating rib 46 on the lower side thereof so that the movement in the thrust direction d is guided, and the regulating rib 46 slides on a guide groove (not shown) of the printer body 1. It's free.

On the side of the unit case 35, there are provided a positioning pin 50 and a leaf spring 51 which is a power supply terminal electrically connected to an electric equipment portion in a developing portion (not shown) of the process unit 5. The leaf spring 51 projects outward from a through hole 35a formed in the side wall of the unit case 35, and the projecting portion 51a of the leaf spring 51 is elastic by itself so that the through hole 3a.
It is possible to appear and disappear for 5a.

FIG. 4 is a main part for explaining the connection between the power supply terminal 52 on the electric component side of the controller unit 11 of the printer body 1 and the rotary shaft 6a which is the ground (GND) terminal of the photosensitive drum 6. FIG. 5 is a sectional view of a main part for explaining the connection between the power supply terminal 53 of the controller unit 11 of the printer body 1 and the like on the electrical component side and the leaf spring 51 which is the power supply terminal.

4 and 5, the process unit 5
Attaching to and detaching from the printer body 1 (take out in the direction of arrow G,
In order to facilitate the attachment, the play (movable) is provided in the thrust direction d so as not to contact the surrounding members. Therefore, this play causes rattling of the process unit 5 at the time of mounting. However, in this example, with respect to the unit case 35 of the process unit 5, at the time of transmitting the driving force, the helical gears 40 and 41 on the driven side and the driving side that meshes with the helical gears 40 and 41 are connected. Aru helical gear 44, 45
Since a force to move in the thrust direction d is exerted by and, the rotation shaft 6a of the photosensitive drum 6 and the leaf spring 51 are received by the guide of the regulating rib 46 and the unit case 35.
At the same time, the power supply terminals 52 and 53 of the printer body 1 are moved in the installation direction (distance f).

Therefore, the rotary shaft 6a which is the ground terminal portion of the photosensitive drum 6 and the leaf spring 51 which is the power supply terminal.
Means that the power supply terminals 52 and 53 formed of leaf springs on the electric component side of the controller unit 11 and the like make elastic contact with the power supply terminals 52 and 53, and the amount of bite is equal to the inner wall of the printer body 1. Since it is regulated by contact with the unit case 35, it does not change even if the process unit 5 is repeatedly attached and detached. Therefore,
The stable electrical connection state of the contact pressure is maintained, and a reliable power supply unit can be configured without increasing the number of parts.

FIG. 6 shows the printer body 1 and the unit case 35.
6 is an explanatory view for explaining a locking relationship with a positioning pin 50 as a locking part in FIG. 7, FIG. 7 is an explanatory view of a locked state of a main part in FIG. 6, and FIG. FIG. 3 is a perspective view showing a locking portion on the printer body 1 side.

A substantially U-shaped locking groove 55 is formed on the inner wall of the printer body 1, and the end of the positioning pin 50 of the unit case 35 is locked to the bottom of the locking groove 55, The process unit 5 is attached and fixed to the printer body 1 in a predetermined mounting state. Further, in the vicinity of the locking groove 55 of the printer body 1, a projecting piece portion 56 having a slope 56a on the lower side is provided.

As described above, the helical gears are transmitted to the unit case 35 of the process unit 5 when transmitting the driving force.
40 and 41 and helical gears that mesh with the helical gears 40 and 41
Since a force to move in the thrust direction d is applied by 44 and 45, the positioning pin 50 along with the unit case 35 receiving the guide of the regulating rib 46 is directed toward the protrusion 56 of the printer body 1. Will be moved. And by the upper end portion 35a of the unit case 35 comes into contact with the lower inclined 56a of the protrusion portion 56, the component force S _H by the thrust force S is branch pressure the unit case 35 downward. That is, the positioning pin 50 acts on the bottom of the locking groove 55 in the direction of downward pressure (the direction of arrow H) (FIG. 7).
reference). Therefore, the process unit 5 is fixed and held in a predetermined position of the printer body 1 in a stable state without providing a special pressing member.

The helical gears 40, 41, 44, 45 are provided on the driven portion and the driving portion of the photosensitive drum 6 and the developing roller 9, but the thrust force acting as described above is sufficient. If so, it may be provided on either one of the photosensitive drum 6 and the developing roller 9. Further, although the thrust force is used to generate the holding force for positioning and fixing the process unit 5, an example in which the projecting piece portion 56 is provided as a force dividing portion for generating the holding force However, the present invention is not limited to this example. Furthermore, it is conceivable that all of the thrust forces are not necessarily used at the same time, and any one may be appropriately selected depending on the specifications of the device.

[0028]

As described above, according to the present invention,
By utilizing the thrust force generated during the rotation of the helical gear as a force for bringing the process cartridge and the power feeding means into contact with each other, the electrical connection between the power feeding means and the process cartridge becomes stable and reliable, and the thrust By utilizing the force as a force for bringing the engaging portions of the process cartridge and the main assembly of the apparatus into contact with each other, the process cartridge can be attached and fixed in a stable and reliable manner. Therefore, it is possible to provide an image forming apparatus in which stable power feeding and stable mounting are performed without increasing the number of components.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram in a laser printer for explaining an embodiment of the present invention.

FIG. 2 is a perspective view showing a main part of the process unit shown in FIG.

FIG. 3 is a plan view of a main part of FIG. 2;

FIG. 4 is a cross-sectional view of a main part for explaining a connection between a power supply terminal on the electric component side of a controller unit of the printer body and a ground terminal portion of a photosensitive drum.

FIG. 5 is a cross-sectional view of a main part for explaining the connection between a power supply terminal on the electrical component side of the controller unit of the printer body and a power supply terminal on the developing unit side.

FIG. 6 is an explanatory diagram for explaining a locking relationship between a printer body and a positioning pin of a unit case.

FIG. 7 is an explanatory diagram of a locked state of a main part in FIG.

FIG. 8 is a perspective view showing a locking portion that locks a positioning pin on the printer body side.

[Explanation of symbols]

1 ... Printer main body, 5 ... Process unit, 6 ... Photosensitive drum, 9 ... Developing roller, 35 ... Unit case, 40, 41, 44, 45 ... Helical gear, 42 ... Drive motor, 46 ... Regulating rib, 50… Positioning pin, 51…
Leaf springs (power supply terminals), 52, 53 ... Power supply terminals on the printer body side, 55 ... Locking grooves, 56 ... Projection piece, 56a ...

Claims (4)

[Claims] 1. A process cartridge comprising an electrostatic image forming process constituent member such as a photosensitive member and a developing roller is detachably mounted on an apparatus main body, and is rotationally driven from a drive source with respect to the photosensitive member and the developing roller. In the image forming apparatus configured to transmit a force and further electrically connect a part of the process cartridge and a power feeding unit provided in the apparatus body in a state where the force is transmitted to the apparatus body, the photosensitive member and the developing roller are provided. At least one of the driven part and the driving part of the driving source is meshed by a helical gear to transmit the rotational driving force, and further, in the direction of contacting the process cartridge with the power feeding means at the time of transmitting the driving force. An image forming apparatus, characterized in that the helical gear is formed so that a thrust force is generated on the process cartridge. 2. A process cartridge comprising an electrostatic image forming process constituent member such as a photoconductor and a developing roller is detachably mounted on the apparatus main body, and is rotationally driven from a drive source with respect to the photoconductor and the developing roller. In an image forming apparatus having a structure in which a force is transmitted, and further provided with a process cartridge and an apparatus main body in a state of being attached to the apparatus main body and an engaging portion for engaging with each other, the photosensitive member and the developing roller are At least one of the driven part and the drive part of the drive source is meshed with a helical gear to transmit the rotational driving force, and further, the thrust in the direction in which the locking portions are locked to each other when the driving force is transmitted. An image forming apparatus, characterized in that the helical gear helical is formed so as to generate a force to the process cartridge. 3. A process cartridge comprising an electrostatic image forming process constituent member such as a photoconductor and a developing roller is detachably attached to the apparatus main body, and rotationally driven from a drive source with respect to the photoconductor and the developing roller. The force is transmitted, and a part of the process cartridge is electrically connected to the power supply means provided in the apparatus main body while being attached to the apparatus main body, and moreover, the process cartridge and the apparatus main body are provided with the device main body. In an image forming apparatus having a configuration in which an engaging portion that engages with each other in a mounted state is provided, a helical gear is provided for a driven portion of at least one of the photoconductor and the developing roller and a driving portion of a drive source. The process cartridge is brought into contact with the power feeding means at the time of transmitting the driving force and the locking portions are mutually engaged. An image forming apparatus, wherein a helical gear is formed so as to generate a thrust force for locking the process cartridge with respect to the process cartridge. 4. A part of the thrust force generated in the direction in which the process cartridge contacts the power supply means,
The image forming apparatus according to claim 3, wherein a component force portion that branches in a direction in which the locking portions are locked to each other is provided in the apparatus main body.