JPH02183286A - electrophotographic equipment - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to electrophotography in which an electrostatic latent image formed on a photoreceptor is developed using toner particles, the toner is transferred to paper, and the image is fixed by heat, pressure, etc. It is related to the device.

2. Description of the Related Art Conventionally, most electrophotographic devices have been devices that use dry toner, and have been put into practical use as copying machines, laser printers, and the like. This electrophotographic apparatus is a device that applies electrophotographic process technology, and in the electrophotographic process, a developing process is to develop an electrostatic latent image formed on a photoreceptor using toner particles. A device that constitutes a developing process. For example, a developing device that uses a two-component developing method that uses a mixture of toner and carrier as a developer generally uses a developing vat filled with developer and a toner hopper that stores replenishment toner. It has become. The toner in the toner hopper falls into the developing vat by the rotation of the toner supply roll, and is controlled so that the mixing ratio of toner and carrier in the developing vat is always kept constant. The toner filled in the toner hopper decreases as it is used, and some of it may adhere to the inner wall of the toner hopper, causing toner blocking (solidification), or may accumulate in stagnation areas. If toner remains in the toner hopper, the capacity of the toner hopper becomes substantially small. Therefore, various attempts have been made to reduce toner blocking or toner remaining in the stagnation.

Hereinafter, a conventional developing device in an electrophotographic apparatus will be described with reference to the drawings.

FIG. 6 is a side sectional view of a conventional developing device, and FIG. 7 is a perspective view of a main part of toner hopper oil in the conventional developing device.

In FIGS. 6 and 7, reference numeral 1 denotes a photoreceptor which is made of a tube made of aluminum or the like, and a photoreceptor layer such as selenium (Se) or organic photoconductor (OPC) is coated on the outer peripheral surface in the form of a thin film. Reference numeral 2 denotes a charger, which is composed of a charging wire 3 made of tungsten wire or the like, a shield plate 4 made of a metal plate, and a grid plate 5. By applying a high voltage to the charging wire 3, charging 1! 3 causes corona discharge, and the photoreceptor 1 is uniformly charged via the grid plate 4. Reference numeral 6 denotes an exposure light beam emitted from an optical unit (not shown), which in the case of a copying machine is a reflected light beam from a document, and in the case of a laser printer, it is an image data beam. In the case of a laser printer, this exposure light beam 6 is controlled by signals from a host computer (not shown), and a desired image is formed on the photoreceptor 1 as an electrostatic latent image. 7 is a developing device, including a toner hopper 9 that stores toner 8, and a developing vat that mixes and stirs the toner 8 and carrier 10, which is magnetic particles such as iron powder, and then transports it to a developing sleeve 11 to form a magnetic brush. It consists of 12. 13 is a toner hopper lid. A toner discharge roller 14 is rotatably supported at both ends within the toner hopper 9 and supplies a certain amount of toner 8 from the toner hopper 9 into the developing vat 12, and blocks the toner discharge port 15. Reference numerals 16a and 16b are loop-shaped motion transmitting members such as belts, chains, or lobes. The motion transmitting members 16a and 16b are sprockets 18 fixed to a rotating shaft 17 whose both ends are supported in parallel with the toner discharge roller 14.
a, 18b and the fixed shaft 19. 2
0 is a shaft-shaped stirring member that is arranged substantially parallel to the rotating shaft 17 and has both ends attached to the motion transmitting members 16a and 16b. The sprocket 18a118b and the toner discharge roller 14 drive the sprocket gear 26 and the toner discharge roller gear 27, respectively, via idler gears 23, 24, and 25 using power from a drive source 22 such as a stepping motor disposed on the chassis 21 of the machine body. Rotates by driving. Furthermore, the toner discharge roller 14 is arranged so as to be in light contact with the toner hopper inner wall 9a. It is attached so as to be moved along the inner wall of the hopper 9. A developer mixer 28 is disposed inside the developing vat 12.The developer mixer 28 is supplied with toner from the toner hopper 9 through the toner outlet 15. The toner 8 and carrier 10 are stirred and mixed, charged, and conveyed to a developing sleeve 11.

The transported toner 8 and carrier 10 are transferred to the developing sleeve 11
A magnetic brush is formed by the magnetic force of a magnet roller 29 fixed therein, and its height is limited by a doctor blade 30. As the developing sleeve 11 rotates, the magnetic brush comes into contact with the photoreceptor 1 and causes the toner 8 to adhere to the portion of the photoreceptor 1 where the electrostatic latent image is formed, thereby forming a powder image. 31 is a toner concentration sensor for detecting the mixing ratio of toner 8 and carrier 10;
is attached to. 32 is a developing section where development is performed.

Next, the operation of the above configuration will be explained. First, a corona discharge is caused by a charging wire 3 in a belt connected to a high-voltage power source and an electric appliance 2 to uniformly charge the surface of the photoreceptor 1 to about -600V to -700V. Next, the photoreceptor 1 is rotated in the direction of arrow A and an exposure beam 6 such as a laser beam is irradiated onto the uniformly charged surface of the photoreceptor 1, and the irradiated portion of the photoreceptor 1 loses its charge. An electrostatic latent image is formed. On the other hand, the carrier 10 and toner 8 in the developing vat 12 are transferred to the developer mixer 2.
8 and is sufficiently frictionally charged and attracted to the magnet roller 29, and as the developing sleeve 11 rotates, the developing section 32
transported to. In this developing section 32, the carrier 10 and the toner 8 form a magnetic brush and come into contact with the photoreceptor 1. At this time, when a potential difference is applied between the developing sleeve 11 and the photoreceptor 1, the toner 8 adheres to the electrostatic latent image portion on the photoreceptor 1 to form a visible image, and the development is completed. Here, the mixing ratio of the carrier 10 and the toner 8 is constantly sensed by the toner concentration sensor 31. When the toner 8 adheres to the photoreceptor 1 in the developing section 32 and is consumed, the toner concentration sensor 31 detects the developing vat 1.
It is detected that the mixing ratio of the carrier 10 and #8 in the carrier #2 is lower than a preset value, and the detection signal is sent to the host computer (not shown), and as shown in FIG. 22 and various gears 23.24.25.26.2
The toner discharge roller 14 is rotated through the toner discharge port 15, and the toner 8 in the toner hopper 9 is replenished onto the developer mixer 28 in the development vat 12 through the toner discharge port 15, and the set mixing ratio is restored to a constant mixing ratio. The ratio will be maintained. Then, as the toner 8 in the toner hopper 9 gradually decreases, the toner 8 decreases to a position below the remaining toner amount sensor 33. Then, the remaining toner amount sensor 33 detects that the amount of toner 8 has decreased and sends a detection signal to the host computer. The host computer is
In response to the detection signal, the user is notified that the remaining amount of toner 8 is low.

Problems to be Solved by the Invention Conventional electrophotographic devices configured as described above are designed to have as wide a bottom area as possible in order to maximize the amount of toner accumulated in the toner hopper 9. In order to move the developer mixer 28 over the entire area of the toner hopper 9 having a large bottom area, the developer mixer 28 is driven by an expensive motion transmission member such as a chain or a timing belt.

Therefore, there was a problem in that the electrophotographic apparatus became expensive.

Means for Solving the Problems However, the present invention eliminates the above-mentioned drawbacks by providing a toner discharge port dividing the bottom surface of the toner hopper at the bottom surface, and disposing a toner discharge port on each portion of the divided bottom surface. The reason is that toner stirring members are provided that rotate one by one around a specific axis.

Effect: By the above means, the toner in the toner hopper is agitated by the toner agitation members provided on the respective parts of the bottom surface divided by the recessed portion in which the toner discharge roller is accommodated, and the toner in the toner hopper is reduced. When the toner reaches the toner, the toner is pushed toward the toner discharge roller by each toner stirring member.

Example An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a side sectional view showing an embodiment of the electrophotographic apparatus of the present invention, FIG. 2 is an exploded perspective view of a part of the toner hopper of the electrophotographic apparatus of the present invention, and FIG. 3 is a circuit block diagram of the same. 4 is a characteristic diagram of the same operation, and FIG. 5 is a flowchart showing the same operation.

Here, the same constituent members as those of the conventional electrophotographic apparatus described above will be given the same numbers and detailed explanations will be omitted.

In FIGS. 1 and 2, 36a and 36b are rod-shaped stirring members rotatably held by holding members 37a, 38a and 37b, 38b, respectively.

Further, the stirring members 36 and 36b are provided on one bottom surface 9a and the other bottom surface 9b of the toner hopper 9 divided by the toner discharge port 15, respectively. 3
9a and 39b are stirring members 36a and 36b, respectively.
gears attached to one end, each with gear 25
It meshes with the. A toner discharge roller gear 27 is also meshed with the gear 25. Gear 39b is connected to motor 22 via idler gears 23,24. Furthermore, one bottom surface 9a of the toner hopper is formed lower than the other bottom surface 9b.

34 is a motor control device, which is composed of a microcomputer and the like. The toner concentration sensor 31 is connected to the data input terminal of the motor control device 34, and the motor 22 is connected to the output terminal. 35 is a power source.

Next, the operation of the above configuration will be explained. First, a corona discharge is caused by a charging wire 3 in a charger 2 connected to a high-voltage power source to uniformly charge the surface of the photoreceptor 1 to about -600V to -700V. Next, the photoreceptor 1 is rotated in the six directions of the arrows and an exposure light beam 6 such as a laser beam is irradiated onto the uniformly charged surface of the photoreceptor 1, and the irradiated portion of the photoreceptor 1 loses its charge. An electrostatic latent image is formed. On the other hand, the carrier 10 and toner 8 in the developing vat 12 are transferred to the developer mixer 28.
is sufficiently frictionally charged and attracted to the magnet roller 29, and is conveyed to the developing section 32 by the rotation of the developing sleeve 11. In this developing section 32, the carrier 10 and the toner 8 form a magnetic brush and come into contact with the photoreceptor l. At this time, if a potential difference is applied between the developing sleeve 11 and the photoreceptor 1,
The toner 8 adheres to the electrostatic latent image portion on the photoreceptor 1 to form a visible image, and development is completed. Here carrier 10 and toner 8
The mixing ratio with toner is constantly sensed by the toner concentration sensor 31.

The following operation will be explained according to the flowchart shown in FIG. When the toner 8 adheres to the photoreceptor 1 and is consumed by the developing section 32, the toner concentration sensor 31 detects that the mixture ratio of the carrier 10 and toner 8 in the developing vat 12 becomes lower than the preset toner replenishment start level, and this is detected. is detected in step a, the detection signal is led to the motor control device 34, and as shown in FIG.
It drives various gears 23, 24, 25, 26, 27 in normal rotation.
toner discharge roller 14 and stirring member 36a via
, 36b are rotated in the normal direction to replenish the toner 8 in the toner hopper 9 onto the developer mixer 28 in the developing vat 12 through the toner discharge port 15. In step C, it is checked whether or not the toner in the developing vat 12 has recovered to the toner replenishment stop level. If the toner has recovered to the toner replenishment stop level, the process proceeds to step d, where the motor 22 is stopped and the toner discharge roller 14 and agitator are stopped. Rotation of members 36a and 36b is stopped. In this way, the set mixing ratio is restored and a constant mixing ratio is maintained. In step e, it is checked whether image formation has ended or not. If it has ended, the process goes to end the operation, and if it has not ended, it returns to step a. As the image forming operation progresses, the toner 8 in the toner hopper 9 gradually decreases until only the blocked toner 8 remains, as shown by line Q in FIG. Then, even if the motor control device 34 instructs the motor 22 to rotate forward, the toner 8 is no longer discharged from the toner hopper 9, and the toner 8 in the developing vat 12 gradually decreases until the toner discharge stop level is reached in step C. The amount of toner will not reach the maximum amount. The process then proceeds to step f, and it is checked whether this is the first time that the amount of toner does not reach the toner discharge stop level even if the motor 22 is instructed to rotate forward. If this is the first time that this condition occurs, proceed to step g, and display that the amount of toner is low.When the amount of toner decreases to the level at which the motor starts reversing, proceed to step 11. , reverse the motor 22. Then,
The stirring members 36a and 36b are also reversed, and the toner hopper 9
The toner 8 that was blocking inside the stirring member 36a
, 36b to the developing vat 12. At this point, the process returns to step C, and the operations from step e to step a are not repeated. As the image is formed, the toner 8 in the toner hopper 9 decreases, and the stirring member 3
Even if 6a and 36b are rotated in the normal direction, the toner concentration remains unchanged in the stirring member 36.
If it does not rise to the stop level of a, 36b, step C
Proceed to restep f. In this case, since it is the second time that the process proceeds to step f, the process proceeds to step i, displays that the toner has run out, and stops the operation.

In this way, the electrophotographic apparatus of the present invention has the toner discharge port 15.
Since toner stirring members are provided on one and the other of the bottom surfaces of the toner hopper 9 divided by , the toner remaining on the bottom surface of the toner hopper 9 is reliably discharged from the toner discharge port 15 by the stirring members.

Effects of the Invention As described above, the present invention provides a toner discharge port that divides the bottom surface of the toner hopper, and a toner discharge port that rotates around a specific axis, one at a time, on each portion of the divided bottom surface. Since a toner stirring member is provided, the toner stirring member can be moved along almost the entire bottom surface of the toner hopper without the need for expensive chains or timing belts, providing an inexpensive electrophotographic device. can do.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view showing an embodiment of the electrophotographic apparatus of the present invention, FIG. 2 is a perspective view of a portion of the toner hopper, FIG. 3 is a circuit block diagram, and FIG. 4 is an operational characteristic diagram. FIG. 5 is a flowchart showing the same operating state, FIG. 6 is a side view of the conventional electrophotographic apparatus, and FIG. 7 is a perspective view of a portion of the toner hopper. 1... Photoreceptor 2... Charger 3...
Charged wire 4... Shield plate 5... Grid plate 6.
...Exposure light beam 7...Developing device 8...Toner 9.
... Toner hopper 10 ... Carrier 1
1...Developing sleeve 12...Developing vat 13
... Toner hopper lid 14 ... Toner discharge roller
15... Toner discharge port 22... Drive source 23,2
4.25... Idler gear 27... Toner discharge roller gear 28... Developer mixer 29... Magnet roller 30... Doctor blade 31... Toner concentration sensors 36a and 35b are the stirring members 32.・・Developing section Fig. 1 Fig. 5 Fig. 11: Developing sleeve Fig. 1

Claims (1)

[Claims] A developing means for supplying toner to a photoconductor, and a toner hopper for supplying toner to the developing means, a toner discharge port is provided on the bottom surface of the toner hopper so as to divide the bottom surface, and a toner discharge port is provided in the bottom surface of the toner hopper so as to divide the bottom surface. An electrophotographic apparatus characterized in that at least one toner stirring member rotating about a predetermined axis is provided on each portion of the bottom surface.