JP2575021B2 - Photoconductor device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reset at the time of exchanging a photosensitive device using an electrophotographic method such as a non-impact printer or a copying machine.

(Prior art) Photoconductors of printers and copiers using electrophotography
They may be replaced periodically or due to obstacles. The photoreceptor has a belt-like or drum-like structure, and the user usually replaces the former belt-like one in which the photoreceptor is housed in a cartridge formed of resin. When the cartridge is set in the machine, some of the claws provided on the cartridge press the reset lever of a mechanical counter for the photosensitive member in the machine to reset the counter. In this case, if the balance between the rigidity of the claw of the cartridge and the reset force of the counter is not properly adjusted, incomplete reset is likely to occur. That is, at the time of resetting, if the rigidity of the claw of the cartridge is high, the cartridge does not break even if it hits the reset lever, and the counter is reset each time the cartridge is inserted and removed, so that it is difficult to confirm the reset state. On the other hand, if the rigidity of the claws is weak, the reset lever cannot be pushed all the way, and there is a disadvantage that the counter is broken without resetting the counter.

In the latter drum type, a serviceman usually replaces the photoconductor, and at that time, the serviceman presses a reset lever of a photoconductor counter in the machine body to reset the counter. In this replacement work, the reset process of the counter is performed almost completely in the case of a service person, but when the user performs this process, the reset lever may be forgotten to be pressed, and the reset may not be performed. For this reason,
Even if a new photoconductor is replaced, there is a drawback that the display on the machine keeps showing the state of replacement of the photoconductor.

(Problems to be Solved by the Invention) The present invention solves the above-mentioned drawbacks of the prior art, and replaces a photosensitive member, particularly, a drum-shaped member in a Neu impact printer or a copying machine using an electrophotographic system. An object of the present invention is to reliably detect the fact that a photoconductor has been replaced.

(Means for Solving the Problems) A photoreceptor device of the present invention is detachably mounted at a mounting position in an apparatus main body, and is rotated by a driving force from the apparatus main body, and an end face of the photoreceptor drum. A plurality of reset detection claws are arranged along the same circumference around the rotation axis of the photosensitive drum in the flange portion provided, and are sheared near the root when receiving a predetermined pressure or more. A reset detection claw at the standby position when the photosensitive drum mounted at the mounting position is rotatably supported in a range from a standby position to a reset position in the apparatus main body. In this case, the rotational force from the photosensitive drum is transmitted by the reset detecting claw and swings to the reset position. The reset lever is provided with a reset lever that is sheared by a reaction force and returns to a standby position after the reset detection claw is sheared, and a sensor that detects that the reset lever swings from the detection position to the reset position.

(Operation) According to the photoreceptor device of the present invention, when the photoreceptor drum is rotated after being mounted on the mounting position of the apparatus main body, the reset lever at the standby position is engaged with the reset detection claw. Swings to the reset position due to the rotational force transmitted from the photosensitive drum via the reset detecting claw, and at this reset position, the reset detecting claw is sheared by a reaction force against the rotational force. At this time, by detecting that the reset lever has swung from the detection position to the reset position by the sensor, when the photosensitive drum rotates after being replaced with a new one, the reset lever is swung from the standby position to the reset position by the sensor. After the movement is detected and the reset lever swings to the reset position, the reset detection claw is removed from the flange portion of the photoconductor drum. After that, it can be generated only in the period until one rotation.

(Embodiment) FIG. 1 is an external view of a photosensitive drum and a drive shaft of the present invention, and FIG. 2 is a diagram showing a coupling state between the photosensitive drum and the drive shaft.

In the figure, reference numeral 1 denotes a drum-shaped photoreceptor, as shown on the end surface thereof, which has a female serration 3 with a tapered rear flange 2 at appropriate intervals around the serration. In this case, a plurality of reset detection claws 4 are provided. Reference numeral 5 denotes a side plate of the machine main body. A reset lever 7 is fitted into a notch 6 of the side plate, and a tip end thereof is set at a position where it engages with the reset detection claw 4 in a state as shown in FIG. Further, the reset lever 7 is held at a standby position by its own weight, and the other end of the reset lever 7 is set in the standby position so as to be located in a concave wall of a photo interrupter 8 which is an optical sensor. Reference numeral 9 denotes a drive shaft of the drum-shaped photoreceptor 1, on which a male serration 3 'is axially mounted, and which is fitted to the female serration 3 of the photoreceptor in a state as shown in FIG. I have. The reset lever 7 is rotatably mounted on the drive shaft 9 by a bearing 9-1.

When the photosensitive member 1 of the present invention configured as described above is replaced, the photosensitive member 1 which is reset by a drawer which will be described later and is pushed into the machine main body is engaged with both serration portions 3 and 3 ′, and the photosensitive shaft 1 is driven by the drive shaft 9. The body 1 is driven to rotate (arrow) in the state shown in FIG. At this time, the reset detection pawls 4 are simultaneously driven to rotate, and the tip of the reset lever 7 is engaged with the pawls 4 in a state as shown in FIG. , The reset lever is swung in the direction of the arrow (a),
The other end of the reset lever is an arrow (a) with the bearing 9-1 as a fulcrum.
And exits from the inside of the concave wall of the photo interrupter 8. The photo interrupter detects this and generates a signal, so that the controller on the machine body side can detect that the photoconductor has been replaced.

Thereafter, the photoreceptor continues to rotate, and the reset lever 7 swings to a reset position where it hits the notch 6 of the main body side plate, thereby fixing the reset lever.
Shears near the root due to the reaction force from the reset lever,
It is removed from the flange 2. In this embodiment, the nails are 2
However, if the drawer is pushed into the machine body and the position of the photoreceptor claw 4 coincides with the reset lever 7, the pushing force may be cut off. Multiple nails are required. In this case, the photo interrupter is operated a plurality of times by a plurality of claws. In this case, the last operation may be detected.

Next, in printers that require strong user maintenance, including the photoreceptor unit described above, it is required that the user can easily replace the developing unit, the cleaning unit, and the like as well as supplying toner. .

Conventionally, the replacement unit is integrally configured from such a viewpoint, and after a certain period of time, if there is a unit whose replacement life has expired, the replacement unit has been replaced as a single unit even if another replacement unit is still usable. The parts cost is high,
Therefore, there is a disadvantage that the running cost is inevitably increased and a heavy burden is imposed on the user.

Therefore, in order to eliminate this drawback, there is a method of setting an individual exchange cycle for each exchange unit and performing individual exchange. This requires a drawer mechanism for each replacement unit, and the position of each unit surface must be accurately positioned. Also, since each replacement unit is placed in a narrow space, replacement work is difficult. However, there is a disadvantage that other units may be damaged when the drawer is pulled out, and the toner may fall and stain the inside.

Further, as another method, there is a method in which each unit is set as a work unit, the whole is pulled out of the apparatus main body, and each unit is replaced. This is disadvantageous in that each unit is positioned with the precision required to operate in the apparatus main body, and since it is pulled out as it is, it is difficult to remove the unit.

In order to solve these problems, an example of an apparatus for replacing an image forming unit such as a photoconductor unit, a developing unit, and a cleaning unit in a non-impact printer or a copying machine using an electrophotographic system will be described below.

FIG. 3 is a perspective view when the present invention is applied to a laser printer, and shows a state where a drawer holding an image forming unit (replacement unit) is pulled out from the laser printer main body.
FIG. 4 is a view showing a partial cross section of the drawer of FIG.

As shown in FIGS. 3 and 4, the laser printer of this embodiment has a drawer 11 slidably mounted on one side surface of a main body 10 by supporting guide rails 12, 12 '.

An image forming unit such as a photoreceptor unit 13, a developing unit 14, a cleaning unit 15, and a toner cartridge 16 is detachably stored in the drawer 11. Drawer 11 is the main body
In the state of being pushed into the unit 10, these units are mounted while maintaining an appropriate positional relationship with each other so that the recording operation by the electrophotographic method is correctly performed, and the optical system unit 21 provided on the main body 10 side, The charging charger 22, the discharging lamp 23, the transfer charger 24, the registration roller 25 and the like are also positioned so as to maintain an appropriate positional relationship.

By pulling the drawer 11 out of the main body 10, the developing unit 14 and the toner cartridge 16 are automatically separated from the photoreceptor unit 13 to the right side in FIG. 4, and the cleaning unit 15 is automatically moved to the left end. Be separated. Due to such isolation of the units, when any one of the units is to be replaced after the replacement time, there is a little space between the adjacent units, so that the operation is simplified and the adjacent units are not damaged. .

A handle 17 for pulling out is attached to the front of the drawer 11. The developing unit 14, the cleaning unit 15, and the toner cartridge 16 are also provided with handles. However, the handle is omitted in FIG. 4 and is not shown.

The main unit 10 has a drawer 11 equipped with the above-mentioned image forming unit.
In addition to the optical system unit 21 for optically scanning the photosensitive member and other components, a first paper supply cassette 18 and a second supply cassette 18 'for supplying recording paper, and a recording developed by the operation unit The image forming apparatus includes a fixing unit 27 for fixing a toner image on paper by heating and pressurizing, a conveying unit 26, and the like. In addition, a first discharge tray 19 and a second discharge tray 19 ', which receive the recorded recording paper discharged through the transport unit 28, are provided at the upper part of the printer body 10.

The printer body 10 is a so-called option, a separate large-volume paper feeding unit 20 used as needed.
-1 and an optional unit including a reversing unit (not shown) for turning over the recording paper recorded on one side exiting the fixing unit 27 and supplying it again to the image forming unit.
It is placed on 20-2.

By raising and covering the cover plate 11-1 while the drawer 11 is housed in the main body, it prevents intrusion of dust and the like,
The appearance can be adjusted.

5 and 6 show an example of a mechanism for separating the cleaning unit 15 from the photoreceptor unit 13 by pulling out the drawer 11. FIG.

Slide hole 31, cleaning unit holding notch 32,
A pair of sliders 35, 35 ′ comprising a spring support projection (pin) 33 and a cam contact portion are disposed before and after in the drawing direction of the drawer 11, and are slidably fixed to the drawer 11 by guide pins 36. A spring support pin 33 fixed to the spring support protrusion 33 of the slider 35 and the bottom of the drawer 11
A spring 39 is stretched between the spring 39 and the spring 38.

In addition, the shaft 41 is passed between the front and rear side plates of the drawer 11, and the cam 41 is fixed at a position corresponding to the position of the cam contact portion 34 of the slider 35, and the shaft 40 is rotated in the axial direction. Attach the biasing spring 37. Such cams and springs are not shown in FIG.
Of course, it is provided corresponding to 35 '. A pin 42 is provided at the rear end of the shaft 40 so as to engage with a cam 43 provided on the main body side.

The cleaning unit 15 has four pins provided at both front and rear ends thereof, of which two pins 44 and 44 'are fitted into the notches 32 and 32' of the slider 35 as shown in FIG. The remaining two pins 45, 45 'are held by a slider 35, as shown in FIG.
6,46 '. The pin bearings 46, 46 '
As shown in FIG. 8, a pin slide slot 47 for slidably supporting the pin in the slide direction is provided, and a notch 48 serving as a pin insertion port is provided above the pin slide slot 47.

In the drawer 11 holding the image forming unit configured as described above, in the operating position where the drawer 11 is stored in the main body 10, the pin 42 at the end of the shaft 40 is directed toward the back of the main body side cam 43. The spring 37 prevents the cam 41 from rotating. Therefore, the spring 39 is attached to the sliders 35 and 35 '.
Only the elastic force effectively acts to position the cleaning unit 15 supported by the sliders 35, 35 'close to the photosensitive unit 13, which is the original operating position. That is, the cleaning unit 15 is brought into a state defined by the spring 39 at a position (reference position) pulled rightward in FIG.

On the other hand, when the drawer 11 is pulled out,
The pin 42 at the end of the shaft bar 40 extending before and after 11 comes off the cam 43 on the main body side, and the rotational force of the spring 37 is
Presses the contact portion 34 of the slider 35, 35 '. As the spring force of the spring 37 is higher than that of the spring 39, the slider 35 moves to the left in the drawing, and as a result, the pins 44 and 44 'of the cleaning unit 15 are moved.
By pulling, the cleaning unit 15 is separated from the photoconductor unit 13.

Although only the cleaning unit 15 has been described above, the developing unit 14 can be separated from the photoconductor unit 13 when the drawer 11 is pulled out by the same mechanism.

In the above example, when the drawer 11 is pulled out from the main body 10, the units set in the drawer 11 are automatically separated from each other, so that the position of the drawer 11 is detected and the sliding operation of a predetermined unit according to the detection is performed. Is performed by a combination of a plurality of cam mechanisms, but the present invention is not limited to such a cam mechanism, but is realized by a combination of other means, for example, an electrical detection of a drawer position and an electromagnetic mechanism driven thereby. be able to.

(Effects of the Invention) According to the photoconductor device of the present invention, when the photoconductor drum is rotated after being replaced with a new one, the sensor detects that the reset lever swings from the standby position to the reset position, and resets. After the lever swings to the reset position, the reset detection claw is removed from the flange portion of the photoconductor drum. Can be generated, so that the replacement of the photosensitive drum can be reliably confirmed by the detection signal from the sensor.

[Brief description of the drawings]

FIG. 1 is an external view of a photosensitive drum and a drive shaft according to one embodiment of the present invention, FIG. 2 is a view showing a coupling state between the photosensitive drum and the drive shaft, FIG. 3 is a perspective view of a laser printer, and FIG. The drawing is a partial sectional view of the drawer of FIG. 3, and FIGS.
FIG. 7 is a view showing an example of a mechanism for separating the cleaning unit 15 from the photoreceptor unit 13 by pulling out the cleaning unit 15, FIG. 7 is a view showing a mechanism for supporting the cleaning unit 15 on the drawer 11, and FIG. 1 ... drum-shaped photoreceptor, 2 ... flange, 3, 3 '...
Serration part, 4 ... claw, 5 ... side plate, 6 ... notch, 7 ... reset lever, 8 ... photo interrupter, 9 ... drive shaft, 9-1 ... bearing.

Claims (1)

(57) [Claims] A photosensitive drum which is detachably mounted at a mounting position in the apparatus main body and is rotated by a driving force from the apparatus main body; and a rotating shaft of the photosensitive drum at a flange provided on an end surface of the photosensitive drum. And a plurality of reset detection claws that are sheared near the root when a predetermined pressure or more is applied thereto, and swing in a range from the standby position to the reset position in the apparatus main body. When the photosensitive drum mounted movably and mounted at the mounting position rotates, the photosensitive drum is engaged with one reset detection claw at the standby position, and the reset detection claw is used by the reset detection claw. Is transmitted to the reset position and swings to the reset position. At the reset position, the reset detection claw is sheared by a reaction force against the rotation force, and the reset detection claw is sheared. After a reset lever that returns to the standby position, the photosensitive member unit, characterized in that the resetting lever is equipped with a sensor for detecting that swings to the reset position from the detecting position.