JPH0498272A - Developing device for electrophotographic device - Google Patents

Abstract

PURPOSE:To stabilize toner end detection, to reduce a cost, and to miniaturize the device by detecting the toner end by electrically connecting electrodes corresponding to the toner replenished from a toner chamber to a developing roll side. CONSTITUTION:The developing device 14 has an elastic member 50 with conductivity attached to an agitater 44 and is rotated integrally with the agitater 44. This member 50 consists of a rectangular thin plate shaped spring member, and its tip 50a is disposed on the opposite side of the agitater 44. On the other hand, this developing device 14 has a fixed terminal 51 provided on a bottom part of the toner chamber 41, and a drive control means connected to this terminal 51 and the member 50 is provided. When toner 43 is replenished by the agitater 44 to a developing chamber, the member 50 is also rotated, and when there is more than a fixed quantity of the toner 43 in the toner chamber 41 and the fixed terminal 51 is in a covered state, the member 50 is deflected and the fixed terminal 51 is not brought into contact. After that, when it is below the fixed quantity, the member 50 is not deflected and the leading tip 50a is electrically connected to the terminal 51, the toner end is detected, and the drive of the developing device 14 is stopped by the drive control means.

Description

[Detailed Description of the Invention] Industrial Field of Application This invention is applicable to electrophotographic devices that use lasers to record on recording media such as paper using an electrophotographic process, such as printers, copying machines, and facsimiles. obtain. Specifically, in such an electrophotographic apparatus, the present invention relates to a developing device that attaches toner to a photoreceptor and develops a latent image on the surface of the photoreceptor into a visible image.

BACKGROUND OF THE INVENTION Conventionally, some developing devices of this type are equipped with a toner end detection mechanism to detect when the toner in the toner chamber has been consumed and has become less than a certain amount. One of the toner end detection mechanisms is a torque type that detects the toner end based on the agitator's torque level, which varies in response to changes in the amount of toner. In addition, there are also devices that detect toner end using a powder level sensor that uses ultrasonic waves.

The problem that Akira is trying to solve is that with the torque method, there is a large variation in the torque fluctuation of the agitator, which causes the problem of unstable toner end detection. Further, when using a powder level sensor, there is a problem that it is expensive and does not adapt to miniaturization of the device.

Therefore, an object of the present invention is to provide the above-mentioned developing device with:
The purpose is to stabilize toner end detection, reduce costs, and downsize the device.

Means for Solving the Problems Therefore, the present invention according to claim 1 provides, for example, the first
As shown in the embodiment shown in the figures to FIG. 5, the agitator 44 in the toner chamber 41 is rotated to send the toner 43 to the developing chamber 34 while agitating it, and the toner 43 is exposed to light by the developing roller 37 in the developing chamber 34. In a developing device 14 of an electrophotographic apparatus that adheres to a body 12 and visualizes a latent image on the surface of the photoreceptor 12, a conductive elastic member 50 is rotatably provided integrally with the agitator 44, and
A fixed terminal 51 that comes into contact with the elastic member 5o when the toner 43 in the toner chamber 41 becomes less than a certain amount is provided at the bottom of the toner chamber 41, and a drive control means is connected to the fixed terminal 51 and the elastic member 50. It is characterized by being prepared.

Further, in the present invention as set forth in claim 2, as shown in the embodiments shown in FIGS. 6 to 8, for example, the toner 43 in the toner chamber 41 is sent to the developing roller 37 side,
In the developing device 14 of the electrophotographic apparatus, which attaches the toner 43 to the photoreceptor 12 with the developing roller 37 and visualizes the latent image on the surface of the photoreceptor 12, the toner 43 is placed on the bottom of the toner chamber 41. a rotating member 52 rotatably provided around a fulcrum 53, and a biasing member such as a compression spring 55 that rotationally biases the rotating member 52 to send out the toner 43 toward the developing roller 37; , the rotating member 5
2 and a movable terminal 54 provided in the toner chamber 41, when the rotating member 52 is rotated by the urging member and the toner 43 in the toner chamber 41 becomes less than a certain amount, the movable terminal 54 is provided in the toner chamber 41. It is characterized by comprising a fixed terminal 56 with which the terminal 54 comes into contact, and a drive control means connected to the fixed terminal 56 and the movable terminal 54.

Next, as shown in the embodiment shown in FIG. 9 and FIG. In a developing device 14 of an electrophotographic apparatus that attaches toner 43 to a photoreceptor 12 and visualizes a latent image on the surface of the photoreceptor 12, it rotates by gravity around a fulcrum 61 provided at the upper part of the toner chamber 41. Toner 43
a rotating member 60 that sends out the image to the developing roller 37 side;
A movable terminal 62 provided on the rotating member 6o and a movable terminal 62 provided in the toner chamber 41 rotate the rotating member 60 by gravity and when the toner 43 in the toner chamber 41 becomes less than a certain amount, the It is characterized by comprising a fixed terminal 63 with which the movable terminal 62 comes into contact, and a drive control means connected to the fixed terminal 63 and the movable terminal 62.

Furthermore, this invention according to claim 4 is, for example,
As shown in the embodiment shown in the figure and FIG. A developing device 14 of an electrophotographic apparatus that visualizes a latent image includes a movable member 65 movably disposed on one side of the toner chamber 41 and having a movable terminal 66, and a movable member 65 disposed on the other side. 1-
A biasing member such as a compression spring 67 that sends the toner 43 toward the developing roller 37 side is provided in the toner chamber 41, and the biasing member moves the moving member 65 to release the toner in the toner chamber 41. The device is characterized by comprising a fixed terminal 68 that the movable terminal 66 comes into contact with when 43 becomes below a certain amount, and a drive control means that connects the fixed terminal 68 and the movable terminal 66.

In the developing device 14 of the present invention as set forth in claim 1, the elastic member 50 rotates together with the agitator 44. In this case, when there is a certain amount or more of toner 43 in the toner chamber 41, the elastic member 50 is bent by the toner 43 and does not contact the fixed terminal 51. Thereafter, when the toner 43 is consumed and becomes less than a certain amount, the elastic member 50 contacts the fixed terminal 51 without being bent. Thus, the toner end is detected.

Further, the developing device 1 of the present invention according to claims 2 to 4
In step 4, the rotating members 52 and 60 are rotated or the moving member 65 is moved to send the toner 43 in the toner chamber 41 toward the developing roller 37 side. Then, when the toner 43 is sent out and becomes less than a certain amount, the movable terminals 54, 62, 6
6 and fixed terminals 56, 63, and 68 are in contact with each other. Thus, the toner end is detected.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 4 is a schematic diagram of the overall internal mechanism of a laser printer equipped with a developing device which is an embodiment of the present invention as set forth in claim 1. What is indicated by the reference numeral 10 in the figure is the main body of the apparatus. The apparatus main body 10 is composed of an upper structure 10a and a lower structure 10b, and the upper structure 10a is attached to the lower structure 10b by a shaft 11 so as to be openable and closable. Inside the main body 10 of the apparatus, a belt-shaped photoreceptor 12 is provided at the center.

A charging device 13, a developing device 14, a transfer device 15, and a cleaning device 16 are arranged around the photoreceptor 12 in the driving direction indicated by the arrow. An optical writer 18 is arranged below the charger 13 and the cleaner 16,
A paper feed cassette 19 is disposed diagonally above the developing device 14.

Then, the paper fed from the paper feed cassette 19 by the paper feed roller 20 is conveyed to the upper side of the photoreceptor 12 with timing determined by the pair of registration rollers 21. The photoreceptor 12 is driven counterclockwise as shown by the arrow,
At this time, the surface is uniformly charged by the charger 13, and an electrostatic latent image is formed on the photoreceptor 12 by irradiating it with laser light from the optical writer 18. This latent image is made visible by toner when it passes through the developer 14. Then, this visible image is transferred by a transfer device 15 onto the lower surface of the paper that has been conveyed above the photoreceptor 12. The transferred paper is guided by a conveyance guide 23 and conveyed between a fixing roller 17a and a pressure roller 17b of a fixing device 17, and the visible image is fixed thereon. Then, the paper that has left the fixing device 17 is further conveyed to a paper ejection unit 25 by a paper ejection roller 24, guided by a paper ejection guide 26, and stacked on a paper ejection tray 27.

By the way, the above-mentioned developing device includes a box-shaped developing frame 30 as a whole, as shown in FIG. 14 are integrally supported to form a unit.

The entire unit is provided in the lower structure 10b of the device main body 10 so that it can be attached or removed.

The charger 13 is located across the optical path of the laser beam,
It is placed on the opposite side from the developing device 14. The optical component 31 is
2nd CY lens 31. Both ends of a are supported by the engaging portions 31b and placed on the optical path. The engaging portion 31b has a U-shape and is integral with the developing section frame 30. The developer 1
4 includes a developing chamber 34 inside and a photoreceptor 12.
A developing roller window 35 is opened on the side, and a toner supply port 36 is opened on the opposite side to the developing roller window 35. The developing chamber 34 is provided with a developing roller 37, a toner replenishing member 38, a thin layer blade 39, and a static elimination brush 40. The developing roller 3
7 is pressed against the photoreceptor 12 through the developing roller window 35. The tips of the thin layer blade 39 and the static eliminating brush 40 contact the developing roller 37 . The developing device 14
In this case, the toner cartridge 42 is integrally connected to the toner supply port 36 side by heat welding or the like, and the opening 42a and the toner supply port 3 are connected together.
Connect with 6. The toner cartridge 42 forms a toner chamber 41 that accommodates toner 43 therein, and rotatably supports an agitator 44 on a support shaft 44a.

When the agitator 44 rotates clockwise as indicated by the arrow, the toner 43 flows into the developing chamber 34 while agitating the toner 43.
Replenish 3. The toner replenishing member 38
The toner 43 is attached. The attached toner 43 is
The tip of the thin layer blade 39 is used to dam and thin the layer. Then, toner 43 is attached to the photoconductor 12 against which the development roller 37 is pressed through the development roller window 35, and the latent image on the surface of the photoconductor 12 is visualized.

More specifically, as shown in FIG. 1, in the developing device 14, a conductive elastic member 5o is attached to the agitator 44, and the elastic member 50 is rotatable together with the agitator 44. This elastic member 50 is made of a long thin plate-shaped spring material. Then, the tip 50a is extended and arranged on the opposite side from the agitator 44. On the other hand, this developing device 14 is provided with a fixed terminal 51 at the bottom of the toner chamber 41. Although not shown, a drive control means connected to the fixed terminal 51 and the elastic member 50 is provided.

In this developing device 14, when the agitator 44 supplies the toner 43 to the developing chamber 34, the elastic member 50 also rotates. At this time, as shown in FIG. 2, there is a certain amount or more of toner 43 in the toner chamber 41.
3 covers the fixed terminal 51, the elastic member 50
is bent by the toner 43 and does not contact the fixed terminal 51. After that, the toner 43 is gradually replenished and when the amount becomes less than a certain amount as shown in FIG. 3, the tip 50a of the elastic member 50 comes into contact with the fixed terminal 51 without being bent. Then, the end of the toner is detected, and the drive control means causes the developing unit 14 to
stop driving.

Next, the developing device 1 of the present invention according to claims 2 to 4
4 has a configuration as shown in FIGS. 6 to 12, for example. As shown in FIG. 6, the developing device 14 of the present invention has a plate-shaped rotating member 52 on which toner 43 is placed at the bottom of the toner chamber 41. As shown in FIG. The rotating member 52 is provided with a rotation fulcrum 53 on the left side of the bottom of the toner chamber 41 in the figure, and is rotatably provided around the fulcrum 53 .

Furthermore, the rotating member 52 is provided with a movable terminal 54 on the right side of the upper surface thereof in the figure. A compression spring (biasing member) 55 provided at the bottom of the toner chamber 41 constantly biases the toner chamber 41 to rotate counterclockwise about a fulcrum 53 . On the other hand, this developing device 14 is provided with a fixed terminal 56 above the toner chamber 41.

Although not shown, a drive control means connected to the fixed terminal 56 and the movable terminal 54 is provided.

Therefore, in this developing device 14, when replenishing the toner 43 in the full state shown in FIG. 6 to the developing roller 37 side, the seventh
As shown in the figure, the rotation member 52 is pushed up and rotated by the compression spring 55, and the toner 43 is lifted and sent to the developing roller 37 side. As shown in FIG. 8, when the toner 43 is fed out to a certain amount or less, the movable terminal 5
4 hits the fixed terminal 56 and conducts contact, thereby detecting the toner end.

Further, the developing device 14 of the present invention according to claim 3 has a ninth aspect.
As shown in the figure, a plate-shaped rotating member 60 is provided above the toner chamber 41 . The rotating member 60 is provided with a rotating fulcrum 61 on the left side of the figure above the toner chamber 41, is rotatable about the fulcrum 61, and is placed on the toner 43. Further, the rotating member 6o is provided with a movable terminal 62 on the left side of the lower surface in the figure. On the other hand, this developing device 14 is provided with a fixed terminal 63 on the side of the developing roller 37 near the upper part of the toner chamber 41. Although not shown, a drive control means connected to the fixed terminal 63 and the movable terminal 62 is provided.

Therefore, in this developing device 14, when replenishing the toner 43 in the full state shown in FIG. 9 to the developing roller 37 side, the first
As shown in FIG. 0, the rotating member 60 is rotated clockwise by gravity to push the toner 43 and send it out to the developing roller 37 side. When the toner 43 is fed out to a certain amount or less, the movable terminal 62 contacts the fixed terminal 63 and conducts the contact, thereby detecting the end of the toner.

Furthermore, as shown in FIG. 11, the developing device 14 of the present invention has a plate-shaped moving member 65 on one side of the toner chamber 41 (on the right side in the figure). The moving member 65 is
A movable terminal 66 is provided on the upper side in the figure. And the moving member 6
5 is a compression spring (biasing member) 67 provided between the negative side of the toner chamber 41 and constantly biased toward the other side. On the other hand, this developing device 14 is provided with a fixed terminal 68 on the other side of the toner chamber 41. Although not shown, a drive control means connected to the fixed terminal 68 and the movable terminal 66 is provided.

In this developing device 14, when replenishing the toner 43 in the full state shown in FIG. 11 to the developing roller 37 side, as shown in FIG.
5 to move and send out the toner 43 to the developing roller 37 side. When the toner 43 is fed out to a certain amount or less, the movable terminal 66 contacts the fixed terminal 68 and conducts the contact, thereby detecting the end of the toner.

In this way, in the developing device 14 of the present invention described in claims 2 to 4, the rotating members 52 and 60 and the moving member 65 are configured to always send the toner 43 to the developing roller 37 side. This eliminates the need for a dedicated agitator for replenishing the toner, thereby reducing the number of parts and lowering costs.

Therefore, according to the present invention, as described above, the toner end is detected by contacting and conducting the electrodes in accordance with the replenishment of toner from the toner chamber to the developing roller side. In the developing device, toner end detection can be stabilized, and the cost can be reduced and the size of the device can be reduced.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing essential parts of a developing device which is an embodiment of the present invention as set forth in claim 1, and FIG. 2 is an internal state of the developing device when the amount of toner in the toner chamber exceeds a certain level. 3 is a sectional view showing the internal state when the toner in the toner chamber falls below a certain amount, and FIG. 4 is a schematic overall configuration showing the internal mechanism of a laser printer equipped with this developing device. 5 are enlarged sectional views showing a part of the developing device and its peripheral units. 6 to 8 show the inside of the developing device which is the actual flow side of the present invention according to claim 2, of which FIG. 6 is a sectional view when the toner is full, and FIG. 7 is a sectional view when the toner is in the middle of being fed out. FIG. 8 is a sectional view at the time of toner end. Figures 9 and 10
The drawings show the inside of a developing device that is an embodiment of the present invention, of which FIG. 9 is a sectional view when the toner is full, and FIG. 10 is a sectional view when the toner is exhausted. 11 and 12 show the inside of a developing device that is an embodiment of the present invention, of which FIG. 11 is a sectional view when the toner is full, and FIG. 12 is a sectional view when the toner is exhausted. It is a diagram. 12...Photoreceptor, 14...Developer, 34...Development chamber, 37...
Developing roller, 41... Toner chamber, 43... Toner, 44...
...Agitator, 50...Elastic member, 5
1, 56, 63, 68...Fixed terminal, 5
2.60... Rotating member, 53.61...
・・・・・・Fulcrum, 54・62・66・・・・・・・
- Movable terminal, 55, 67... Compression spring (biasing member), 65... Moving member.・＼ Figure Figure Figure b Figure

Claims (1)

[Claims] 1. The agitator in the toner chamber is rotated to agitate the toner and send it to the developing chamber, and the developing roller in the developing chamber attaches the toner to the photoreceptor to form a latent image on the surface of the photoreceptor. In a developing device of an electrophotographic apparatus for visualizing an image, a conductive elastic member is rotatably provided integrally with the agitator, and a fixed terminal comes into contact with the elastic member when the toner in the toner chamber becomes less than a certain amount. A developing device for an electrophotographic apparatus, comprising a drive control means provided at the bottom of the toner chamber and connected to its fixed terminal and the elastic member. 2. Send the toner in the toner chamber to the developing roller side,
In the developing device of an electrophotographic device, which uses the developing roller to adhere toner to a photoreceptor and visualize the latent image on the surface of the photoreceptor, the toner is placed on the developing device and rotates around a fulcrum located at the bottom of the toner chamber. a biasing member that rotatably biases the rotary member to send the toner toward the developing roller; a movable terminal provided on the rotary member; a fixed terminal that the movable terminal comes into contact with when the rotating member is rotated by a biasing member and the toner in the toner chamber becomes less than a certain amount; and a drive control means that connects the fixed terminal and the movable terminal. A developing device for an electrophotographic device, comprising: and. 3. Send the toner in the toner chamber to the developing roller side,
In a developing device of an electrophotographic device that attaches toner to a photoreceptor using the developing roller and visualizes a latent image on the surface of the photoreceptor, the developing device rotates by gravity around a fulcrum located at the top of the toner chamber. a rotating member that sends toner to the developing roller side; a movable terminal provided on the rotating member; and a movable terminal provided in the toner chamber, which rotates the rotating member by gravity to reduce the amount of toner in the toner chamber to a certain amount or less. A developing device for an electrophotographic apparatus, comprising: a fixed terminal that the movable terminal comes into contact with when the movable terminal is in contact with the movable terminal; and a drive control means that connects the fixed terminal and the movable terminal. 4. Send the toner in the toner chamber to the developing roller side,
In a developing device of an electrophotographic device that adheres toner to a photoreceptor using the developing roller and visualizes a latent image on the surface of the photoreceptor, the developer is movably disposed on one side of the toner chamber and has a movable terminal. a movable member; a biasing member that biases the movable member toward the other side to send the toner toward the developing roller; and a biasing member that is provided in the toner chamber and moves the movable member with the biasing member to send the toner toward the developing roller. A developing device for an electrophotographic apparatus, comprising: a fixed terminal that the movable terminal comes into contact with when the amount of toner in the room becomes less than a certain amount; and a drive control means that connects the fixed terminal and the movable terminal.