JPH01273073A - Electrophotographic copying device - Google Patents

Abstract

PURPOSE:To prevent toner blocking, which is created at such a place as the inner wall of a toner hopper by accommodating a toner discharge roller, which stops up a toner discharge port, in a recessed part, and providing a stirring means which passes and moves over the recessed part. CONSTITUTION:At the same time the toner discharge roller 46 rotates, rotational members 48 a and 48 b rotate in the form of a loop via a revolving shaft 49 and sprockets 50 a and 50 b. Together with that, a stirring part 52 stirs the toner 40 along the entire bottom of the toner hopper 41 while it traverses the upper part of the roller 46, and it also carries away the toner 40 toward the roller 46. Therefore, the blocking of the toner 40 in the hopper 46 is wiped out and the toner in it is completely supplied to a developing vat 44.

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 photosensitive belt is visualized with toner particles, the toner is transferred to paper, and 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 the toner is used, and some of the toner may adhere to the inner wall of the toner hopper, causing toner blocking (solidification), or be deposited in stagnation areas. If toner remains in the toner hopper, the capacity of the toner hopper is substantially reduced, and various attempts have been made to reduce this 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. 3 is a side sectional view of a conventional developing device, and FIG. 4 is a perspective view of a part of a toner hopper of the conventional developing device.

In FIGS. 3 and 4, 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, the charging wire 3 causes a 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 is document light in the case of a copying machine and image data light in the case of a laser printer. In the case of a laser printer, this exposure light ray 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. A developing device 7 includes a tree hopper 9 that stores toner 8, a carrier 10 that is magnetic particles such as iron powder, and a developing sleeve 11 that stores the toner 8 and carrier 10, which is magnetic particles such as iron powder.
It consists of a developing vat 12 which is conveyed to the developing vat 12 to form a magnetic brush. 13 is a toner hopper lid. 14 is a toner discharge roller whose both ends are rotatably supported within the toner hopper 0, and which supplies a certain amount of toner 8 from the toner hopper 9 into the developing vat 12, and which blocks the toner discharge port 15. Reference numerals 16a and 16b are loop-shaped motion transmitting members such as healds, chains, or ropes. Motion transmission member 1
6a and 16b are sprockets 18a fixed to a rotating shaft 17 whose both ends are supported in parallel with the toner discharge roller 14;
18b and the fixed shaft 19. Reference numeral 20 denotes 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 sprockets 18a, 18b and the toner discharge roller 14 are connected to the sprockets I and 14 through 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.
It rotates by driving the gear 26 and the toner discharge roller gear 27. Furthermore, the toner discharge roller 14 is arranged close to the toner hopper inner wall 9a. Motion transmission members 16a, 16b, rotating shaft 17, sprocket) 18a
, 18b, one rotating shaft is attached to move the stirring member 20 along the inner wall of the toner hopper 9. 28 is a developer mixer, which is arranged within the development vat 12. The developer mixer 28 is the toner hopper 9
The toner 8 and carrier 10 supplied through the toner discharge port 15 are stirred and mixed, charged, and released into the developing sleeve 1.
1. The transported L-ner 8 and carrier 10 are transferred to a magnet roller 29 fixed inside the developing sleeve 11.
A magnetic brush is formed by the magnetic force, and its height is limited by the doctor blade 30. Developing sleeve 1
As the magnetic brush 1 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, and is attached to doctor blade 30. 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 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 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, development
The carrier 10 and toner 8 in the cartridge 12 are sufficiently frictionally charged by the developer mixer 28 and transferred to the magnetic roller 29.
is sucked into the developing section 3 by rotation of the developing sleeve 11.
2. 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. The toner 8 is applied to the photoreceptor 1 in the developing section 32.
When the toner particles adhere to the toner and are consumed, the density sensor 31 detects that the mixing ratio of the carrier 10 and toner 8 in the developing vat 12 is lower than a preset value, and the detection signal is sent to the host computer (not shown). As shown in FIG.
5, 26, and 27 to rotate the toner discharge 1 cola 14 and replenish the toner 8 in the toner hopper 9 onto the developer mixer 28 in the development vat 12 through the toner discharge port 15, thereby recovering the set mixing ratio. This will maintain a constant mixing ratio.

Problems to be Solved by the Invention In the conventional developing device configured as described above, the toner 8 in the toner hopper 9 is initially in the state shown by line B in FIG. 3 when the toner hopper 9 is filled. As the toner discharge roller 14 rotates, the toner 8 in the 1-henner popper 9 falls into the developing vat.
It gradually decreases. The toner 8 filled between the toner discharge roller 14 and the toner hopper inner wall 9b is stirred by the stirring member 20 as the motion transmission members 16a and 16b rotate in the direction of arrow C, and the toner 8 is transferred to the toner discharge roller 14 side. 8 is pushed away. This prevents the toner 8 from stagnation, accumulation, and blocking. However, even if the toner 8 on the agitation member 20 side is used up, the toner 8 on the toner discharge roller 14 causes blocking as shown in D and remains unconsumed. In particular, the temperature is 40℃ and the relative humidity is 80%.
This phenomenon occurred noticeably under high temperature and high humidity conditions.

Means for Solving the Problems However, the present invention eliminates the above drawbacks by housing a toner discharge roller in a recess that divides the bottom surface of the toner hopper, and moving the toner discharge roller from one side of the bottom surface of the toner hopper to the other. A stirring member is provided that runs along almost the entire bottom surface of the hopper.

Effect: With the above means, toner falls from the toner discharge port as the toner discharge roller rotates, and some of the toner adheres to the surface of the toner discharge roller and returns to the toner hopper, but the returned toner is stirred by the stirring member. be done. The toner is stirred and transported to the toner discharge roller again. This can prevent toner blocking that occurs on the inner wall of the toner hopper.

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, and FIG. 2 is an exploded perspective view of a portion of the toner hopper of the electrophotographic apparatus of the present invention.

In FIGS. 1 and 2, numeral 33 is a photoreceptor made of a tube made of aluminum or the like, and having a thin film coated with a photosensitive layer of selenium (Se) or organic photoconductor (OPC) on its outer peripheral surface. Reference numeral 34 denotes a charger, which is comprised of a charging wire 35 made of =9-tungsten wire, a shield plate 36 made of an old metal plate, and a grid plate 37. By applying a high voltage to the charging wire 35, the charging wire 35 causes corona discharge, and the photoreceptor 33 is uniformly charged via the grid plate 36. 38 is an exposure light beam emitted from an optical unit (not shown). 39
A developing device includes a toner hopper 41 for storing toner 40 and a developing vat 44. Developing bat 44
Inside, a toner 40 and a carrier 42 which is magnetic particles such as iron powder are used.
are mixed and stirred. The toner 40 and carrier 42 are then conveyed to a developing sleeve 43 to form a magnetic brush. 45 is a toner hopper lid. A toner discharge roller 46 is rotatably supported at both ends within the toner hopper 41 and supplies the toner 40 in the I/Q hopper 41 into the developing vat 44, and blocks the toner discharge port 47. Reference numeral 65 is formed on the bottom surface of the toner hopper 41 and divides the bottom surface into two parts. Further, the recess 65 accommodates the toner discharge roller 46. Reference numerals 48 to 10-a and 48b are loop-shaped motion transmitting members such as healds, chains, or ropes. The four rotating shafts are supported at both ends so as to be parallel to the toner discharge roller 46. There are sprockets h50a and 50b near both ends of this rotating shaft 49.
is fixed. And motion transmission members 48a, 48b
is hung between the sprockets 50a, 50b and the fixed shaft 51, and runs across the top of the toner discharge roller 46 in a direction perpendicular to the axis of the toner discharge roller 46. Here, a rotating shaft or a sprocket may be used instead of the fixed shaft 51. Reference numeral 52 denotes a stirring member in the shape of a round bar, which is arranged substantially parallel to the rotating shaft 49 and whose both ends are attached to the motion transmitting members 48a and 48b. sprocket 50
a, 50b and the toner discharge roller 46 are driven by a driving source 54 such as a stepping motor located on the chassis 53 of the main body of the machine.
are connected via idler gears 55, 56, and 57. The drive source 54 drives the sprocket gear 58 and the toner discharge roller gear 59, thereby rotationally driving the sprockets 50a, 50b and the toner discharge roller 46. A developer mixer 60 is disposed within the developing hat 44 and stirs and mixes the toner 4o supplied from the toner hopper 41 through the toner discharge port 47, and conveys the mixed toner to the developing sleeve 43. The conveyed toner 4o and carrier 42 are formed into a magnetic brush by the magnetic force of a magnet roller 61 fixedly arranged inside the developing sleeve 43, and its height is limited by a doctor blade 62, and as the developing sleeve 43 rotates, the magnetic brush is formed. The brush comes into contact with the photoreceptor 33 and deposits the toner 40 on the electrostatic latent image portion of the photoreceptor 33 to form a powder image. 63 is Tory-46 and Carrier 4
This is a toner concentration sensor that detects the mixing ratio of 2 and is attached to the doctor plate 1/62. 64
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 35 in a charger 34 connected to a high-voltage power source to uniformly charge the surface of the photoreceptor 33 to about -600V to -700V. Next, when the photoreceptor 33 is rotated in the direction of arrow E and the exposure light beam 38 is irradiated onto the uniformly charged surface of the photoreceptor 33, the charge disappears from the irradiated portion and an electrostatic latent image is formed.

On the other hand, the carrier 42 and toner 40 in the developing vat 44 are sufficiently frictionally charged by the developer mixer 60, attracted to the magnetic roller 61, and conveyed to the developing section 64 by the rotation of the developing sleeve 43. In this developing section 64, the carrier 42 and the toner 40 form a magnetic brush, and the photoreceptor 33
come into contact with. At this time, when a potential difference is applied between the developing sleeve 43 and the photoreceptor 33, the toner 40 adheres to the electrostatic latent image portion on the photoreceptor 33, forming a visible image, and the development is completed.

Here, the mixing ratio of the carrier 42 and the toner 40 is constantly sensed by the toner concentration sensor 63.

When the toner 40 adheres to the photoreceptor 33 in the developing section 64 and is consumed, the toner concentration sensor 63 detects that the mixture ratio of the carrier 42 and toner 40 in the developing vat 44 is lower than a certain value, and the detection signal is Guided by a host computer (not shown), the drive source 54 is driven as shown in FIG. 4, and the toner discharge roller 46 is rotated through various gears 55, 56, 57, 58, 59, and the toner discharge port is opened. 47, the toner 4o in the toner hopper 41 is replenished onto the developer mixer 60 in the developing vat 44, and the set mixing ratio is restored to maintain a constant mixing ratio.

In the developing device of the present invention configured as described above, the toner 4o in the toner hopper 41 is rotated simultaneously with the rotation of the toner discharge roller 46, which is initially in the F state, by the power of the drive source 54, which moves the toner 4o through the four rotating shafts, the sprocket 50a, and the sprocket 50a. The rotating members 48a and 48b are connected to the rotating shaft 49 and the fixed shaft 5 via 50b.
Rotate in a loop between 1. Accordingly, the stirring member 52
G along the entire bottom surface of the toner hopper 41 in a direction perpendicular to the axial direction of the toner discharge roller 46
While crossing the vertical upper part of the toner 6, the toner 40 is stirred and the toner 40 is pushed toward the toner discharge roller 46 (in the H direction). As a result, the toner discharge roller 46
The toner at the top gradually decreases. Since the configuration is configured to perform such an operation, the toner 4 in the toner hopper 46
o's block, and toner hopper 41.
It became possible to completely supply the toner inside to the developing hat 44.

Effects of the Invention As described above, the present invention divides the bottom surface of a toner hopper by a recess having a toner discharge port, stores a toner discharge roller that blocks the toner discharge port in the recess, and transfers the bottom surface divided by the recess from one side to the other. Since a stirring member is provided that moves over the recess, even if the toner that adheres to the surface of the toner discharge roller and does not fall from the toner outlet returns to the toner hopper, the stirring member returns it to the recess and prevents blocking. This phenomenon prevents toner from accumulating in the toner hopper. Therefore, almost all of the toner stored in the toner hopper can be used, and the toner in the toner hopper is not wasted. Furthermore, since the capacity of the toner hopper is fully used, the interval between toner replenishment can be extended.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view of an embodiment of the electrophotographic apparatus of the present invention, FIG. 2 is a perspective view of a portion of the same toner hopper, FIG. 3 is a side view of a conventional electrophotographic apparatus, and FIG. 4 is the same. FIG. 3 is a perspective view of a portion of the toner hopper. 33... Photoreceptor 34... Charger 35...
Charged wire 36... Shield plate 37... Grid plate 38... Three exposure light beams...
・Developing device 40...Toner 41...Toner hopper 42...Carrier 43...
・Developing sleeve 44,...Developing vat 45...
・Toner hopper lid 46...Toner discharge roller 4
7... Toner discharge port 65... Concave portion 48a, 4
8b...Motion transmission member 49...Rotating shaft
49...Rotating shafts 50a, 50b...Sprocket 51...Fixed shaft 52...Stirring member 53...Chassis 54...Drive source 55, 56.57...Itrachia 58... Sprocket Kia 59...Toner outlet - Rakia 60...Developer mixer 61...Magnetic roller 62...Doctor blade 63...Toner concentration sensor 64...Name of developer department representative Patent attorney Nakao Toshio 1 idiot 17 Ichishuogi II Akimon Recruitment Ichimon Koku faction

Claims (1)

[Claims] A recess is formed in the bottom of the hopper for storing toner so as to divide the bottom, a toner discharge port is formed in the bottom of the recess, and the toner discharge port is closed and rotated to remove the toner adhering to the surface from the discharge port. An electrophotographic apparatus, characterized in that a toner discharging roller to be discharged is housed in the recess, and a stirring member is provided that moves across the recess over substantially the entire bottom surface of the hopper.