JPH02245779A - Electrophotographic device - Google Patents

Abstract

PURPOSE:To completely supply toner in a hopper outside by providing an electrophotographic device with a motion transmitting member which moves along almost the entire bottom of the toner hopper, and also providing it with a toner scraping and gathering part which hangs down from the supporting part and is inclined toward the center from both ends. CONSTITUTION:The electrophotographic device is provided with the motion transmitting members 16a and 16b both of which move along almost the entire bottoms 9a and 9b of the toner hopper 9; it is also provided with a stirring member 20 which has the toner scraping and gathering part which hangs down from the member supporting part of both the ends and is inclined toward the center from both the ends. The stirring member 20 moves along the bottom of the toner hopper 9 by the motion transmitting members 16a and 16b, and residual toner 8 at the toner hopper bottoms 9a and 9b is securely scraped and gathered by the toner scraping and gathering part; particularly, the toner 8 near the corner of the bottom of the toner hopper 9 is gathered to the central part by an inclined part, and falls onto a toner discharging roller 14. Thus, the residual toner 8 in the toner hopper 9 is considerably reduced, and the capacity of the toner hopper 9 can be efficiently used.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an electrophotographic device in which an electrostatic latent image formed on a photoreceptor is visualized using toner particles, transferred to paper, and fixed by heat or pressure. It is something.

2. Description of the Related Art Conventionally, most electrophotographic apparatuses have been those using dry toner, and have been put into practical use as copiers, laser printers, and the like. This electrophotographic apparatus is a device that applies electrophotographic process technology, and uses toner particles to visualize an electrostatic latent image formed on a photoreceptor. An electrophotographic apparatus that employs a two-component development method that uses a mixture of toner and carrier as a developer generally has a development bat filled with developer and a toner hopper that stores toner for replenishment. The toner in the toner hopper falls into the developing vat by the rotation of the toner discharge roller, 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 the toner may adhere to the inner wall of the toner hopper and cause toner blocking (solidification) or may accumulate in stagnation areas. Ta. When toner remains in the toner hopper, the volume of the toner hopper is substantially reduced.

Therefore, various attempts have been made to reduce the amount of toner remaining in this stagnation area and to completely replenish the toner in the toner hopper to the outside.

A conventionally employed electrophotographic apparatus will be described above with reference to the drawings.

FIG. 9 is a side view of a conventional electrophotographic apparatus, and FIG. 10 is a perspective view of a toner hopper portion of the conventional electrophotographic apparatus. In FIGS. 9 and 10, reference numeral 1 denotes a photoreceptor which is made of a tube made of aluminum or the like and has a thin film coated with a photosensitive layer of selenium (Se) or organic photoconductor (OPC) on its outer peripheral surface. 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 and a grid plate 5 made of sheet metal. By applying a high voltage to the charging wire 3, the charging wire 3 causes corona discharge, and the photoreceptor is uniformly charged via the grid plate 5. 6 is an exposure light beam emitted from an optical unit (not shown). When an electrophotographic device is used in a copying machine, the exposure light beam is a reflected light beam from a document, and when an electrophotographic device is used in a laser printer, the exposure light beam is an image data beam. In the case of a laser printer, the exposure beam 6 is controlled by signals from a host computer (not shown), and the desired image is formed on the photoreceptor 1 as an electrostatic latent image. 7 is a developing device, which includes a toner hopper 9 that stores toner 8 and a developing vat 12.
have. The developing vat 12 stores toner 8 and carrier 10 which is magnetic particles such as iron powder. career 1
0 and toner 8 are mixed and stirred and then conveyed to a developing sleeve 11 to form a magnetic brush. 13 is a toner hopper lid. Reference numeral 14 denotes a toner discharge roller whose both ends are rotatably supported within the toner hopper 9 . The toner discharge roller 14 closes the toner discharge port 15 of the toner hopper 9, and as the toner discharge roller 14 rotates, the toner adhering to the surface of the toner discharge roller 14 is discharged from the toner discharge port 15. Reference numerals 16a and 15b are loop-shaped motion transmitting members such as belts, chains, ropes, etc., and are arranged at both ends of the rotating shaft 17. Motion transmission member 16a
, 16b is a sprocket 1 fixed to a rotating shaft 17 whose both ends are supported so as to be parallel to the toner discharge roller 14.
It is hung between 8a, 18b and the fixed shaft 19. Then, it runs in a direction perpendicular to the axis of the toner discharging roller 14 so as to cross the upper part of the toner discharging roller 14 . 20 is arranged approximately parallel to the rotating shaft 17, and has both ends connected to the rotating member 16a,
This is a round bar-shaped stirring member attached to the rod 16b. The sprockets 18a, 18b and the toner discharge roller 14 are connected to a drive source 22, such as a stepping motor, disposed on a chassis 21 of the machine body via idler gears 23, 24, and 25. Further, a sprocket gear 26 and a toner discharge roller gear 27 are also connected to the drive source 22 via idler gears 23, 24, and 25. 28 is developing bat 1
A developer mixer disposed within the developer sleeve 2 stirs and mixes the toner 8 and conveys it to the developing sleeve 11 . The conveyed toner 8 and carrier 10 are formed into a magnetic brush by the magnetic force of a magnet roller 29 fixed within the developing sleeve 11, and the height thereof is limited by a doctor blade 30. As the developing sleeve 11 rotates, the magnetic brush comes into contact with the photoreceptor 1, and the toner 8 is applied to the electrostatic latent image area of the photoreceptor 1.
to form 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 3o.

32 is a developing section that performs development.

Next, the operation of the above configuration will be explained. First, a corona discharge is performed by a charging wire 3 in a charger 2 connected to a high-voltage power source, and the surface of the photoreceptor 1 is uniformly charged to about 1000V 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 sufficiently frictionally charged by the developer mixer 28 and the magnetic roller 29
is sucked into the developing section 3 by rotation of the developing sleeve 11.
Transported to 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 portion of the photoreceptor 1 where the electrostatic latent image is formed, forming 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, when the amount falls below a predetermined amount, the toner concentration sensor 31 detects that the mixture ratio of the carrier 10 and toner 8 in the developing vat 12 is lower than a certain value, The detection signal is guided to a microcomputer (not shown). Then, as shown in FIG. 4, the microcomputer outputs a start command signal for the drive source 22, and the driving force of the drive source 22 is transmitted to the idler gears 23, 24, 25, sprocket gear 26,
Toner discharge roller 1 via toner discharge roller gear 27
4 and rotates the toner discharge roller 14. This allows the toner to pass through the toner outlet 15 to the toner hopper 9.
The toner 8 inside is transferred to the developer mixer 28 inside the developing vat 12.
The mixing ratio is maintained at a constant level by replenishing the mixture at the top and restoring it to the set 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 a state shown by line B. The toner discharge roller 1 is driven by the power of the drive source 22.
Simultaneously with the rotation of 4, the motion transmitting members 16a and 16b rotate in a loop between the rotating shaft 17 and the fixed shaft 19. Accordingly, the agitating member 20 stirs the toner 8 along the entire bottom surface of the toner hopper 9 in a direction perpendicular to the axial direction of the toner discharging roller 14 while crossing the upper part of the toner discharging roller 14 . (in the direction of arrow H). However, since the stirring member 20 is separated from the bottom surface 9b on the bottom surface 9b, the toner on the bottom surface 9b is not completely carried toward the toner discharge roller 14, and the toner on the bottom surface 9b is
As a result, the toner 8 remained in the toner hopper 9, and the volume of the toner hopper 9 was substantially reduced.Particularly, the toner 8 remained in the toner hopper 9 near the corner of the bottom surface 9b. was accumulating.

Means for Solving the Problems The present invention eliminates the above-mentioned drawbacks by providing a motion transmitting member that moves along almost the entire bottom surface of the toner hopper,
A stirring member was provided, which had supported portions supported by the motion transmission member at both ends, and a toner scraping portion that was inclined from both ends toward the center and hung down from the supported portions.

Function: By the above means, the stirring member is moved along the bottom surface of the toner hopper by the motion transmission member, and since the stirring member has a toner scraping portion, the toner remaining on the bottom surface of the toner hopper is surely scraped up by the toner scraping portion.
In particular, toner near the corners of the bottom surface of the toner hopper is collected in the center by the slope and dropped onto the toner discharge roller.

Example Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a side view showing one embodiment of the electrophotographic apparatus of the present invention, FIG. 2 is a perspective view of a part of the same toner hopper, and FIGS. It is a perspective view of the stirring member in an Example.

In FIGS. 1 to 8, parts given the same numbers as those in the conventional example are the same as those in the conventional example, and therefore the description thereof will be omitted.

In FIGS. 1 to 3, the stirring member 20 is made of a metal wire, and both end portions 20a, 20b are on the same axis, and the inclined portions 20d, 2
A central portion 20c is formed through 0e, and an inclined portion 20d,
20e is inclined from both end portions 20a, 20b toward the center portion 20c, and further, the center portion 20c has both end portions 20a,
It is parallel to the axis passing through 20b. Further, the stirring member 20 is rotatably attached to the motion transmitting members 16a and 16b.

Next, the operation of the electrophotographic apparatus of the present invention configured as described above will be explained. First, while rotating the photoreceptor 1 in the direction of arrow E, a corona discharge is caused by the charging wire 3 in the charger 2 connected to a high-voltage power source to uniformly cover the surface of the photoreceptor 1 at a voltage of -600V to -
Charge it to about 700v. Next, when the exposure light beam 6 is irradiated onto the uniformly charged surface of the photoreceptor 1, the charge disappears in the irradiated area, and an electrostatic latent image is formed. On the other hand, the carrier 1o and toner 8 in the lump image 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 is attached to the electrostatic latent image portion on the photoreceptor 1 to form a visible image, and the development is completed. When the toner 8 adheres to the photoreceptor 1 in the developing section 32 and is consumed, the amount of toner in the developing vat 12 decreases. When the amount of toner in the developing vat 12 becomes less than a predetermined amount, the toner concentration sensor 31 detects that the toner in the developing vat 1
It is detected that the mixing ratio of the carrier 10 and toner 8 in the toner 2 has become lower than a preset value, and the detection signal is sent to a host computer (not shown). Then, the microcomputer outputs a control signal to start the drive source 22, and the rotational force of the drive source 22 is applied to various gears 23, 24, 25.
, 26, 27 to the toner discharging roller 14, causing the toner discharging roller 14 to rotate. Then, the toner adhering to the surface of the toner discharge roller 14 is removed from the toner discharge port 1.
5 and falls into the developing vat 12. This operation is continued until a predetermined mixing ratio of toner 8 and carrier 10 is reached.
A constant mixing ratio will be maintained. In the toner hopper 9, the toner 8 is initially in a state indicated by IF. The driving force of the driving source 22 causes the toner discharge roller 14 to rotate and the rotating shaft 17 . sprocket 18a,
18b rotates, and the motion transmitting members 16a, 16b rotate in a loop between the rotating shaft 17 and the fixed shaft 19. Accordingly, the stirring member 20 first moves along the lower bottom surface 9a in the toner hopper 9, crosses the upper part of the toner discharge roller 14 while rising, and moves along the lower bottom surface 9b. As the stirring member 20 moves, the toner 8 is stirred and pushed toward the toner discharge roller 14.

When the amount of toner 8 decreases and the toner discharge roller 14 is exposed, the toner 8 adhering to the stirring member 20 falls onto the toner discharge roller 14. Here, stirring member 2
0 is rotatably attached to the motion transmitting members 16a and 16b, and the center portion 20c is connected to both end portions 20a and 20b.
Since the central portion 20c is shifted from the toner hopper 9, the central portion 20c always hangs down and moves while rubbing on the bottom surface 9a*9b of the toner hopper 9.

Therefore, even if the toner 8 decreases, the toner 8 will surely come into contact with the stirring member 20, and the toner hopper 9
The toner 8 near the corner of the bottom surface of the stirring member 20
0d and 20e, almost all of the toner 8 in the toner hopper 9 is conveyed onto the toner discharge roller 14, and the amount remaining in the toner hopper 9 is extremely small.

Effects of the Invention As described above, the present invention provides a motion transmitting member that moves along almost the entire bottom surface of the toner hopper, has a supported portion that is supported by the motion transmitting member, and also has a supported portion that moves along an inclined portion from the supported portion. A stirring member having a hanging toner scraping portion is provided, and by this means, the stirring member is moved along the bottom surface of the toner hopper by a motion transmission member,
Since the stirring member has a toner scraping portion, the toner remaining on the bottom surface of the toner hopper is surely scraped up by the toner scraping portion and dropped onto the toner discharge roller.

Therefore, the amount of toner remaining in the toner hopper is extremely small, and the capacity of the toner hopper can be used effectively.

[Brief explanation of drawings]

FIG. 1 is a side view showing an embodiment of the electrophotographic apparatus of the present invention, FIG. 2 is a perspective view of a part of the toner hopper, FIG. 3 is a perspective view of a stirring member in the embodiment, and FIG. 4 5 is a side view of a conventional electrophotographic apparatus, FIG. 6 is a perspective view of a portion of the toner hopper, and FIG. 7 is a front sectional view 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 12 ... Developing vat
10...Carrier 11...Developing sleeve 13
... Toner hopper lid 14 ... Toner discharge roller
15... Toner discharge ports 16a, 16b... Motion transmission member 17... Rotating shafts 18a, 18b... Sprocket 19... Fixed shaft 2o... Stirring member
20a, 20b...both end portions 20c...center portion
20d, 20e... Inclined portion 21... Chassis 22... Drive source 23.24.25
... Idler gear 26 ... Sprocket gear 27 ... Toner discharge roller gear 28 ... Developer mixer 29 ... Magnet roller 30 ... Doctor blade 31 ... Toner concentration sensor 32 ... Developing section substitute Name of person Patent attorney Shigetaka Awano and 1 other person14:
Toner discharge port - Figure 20a-b: Fulcrum 20cmd: Bent part 20e: Center part

Claims (1)

[Claims] A toner discharge port is formed at the bottom of the toner hopper, and a toner discharge roller is provided that covers the toner discharge port and rotates to discharge toner adhering to the surface from the toner discharge port, and extends along almost the entire bottom surface of the toner hopper. an electrophotographic apparatus, comprising: a motion transmitting member that moves by the motion transmitting member; and a stirring member supported by the motion transmitting member at both ends and having a toner scraping portion that hangs down from the supported portion and slopes from both ends toward the center. Device.