JP3142971B2 - Developing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device used for developing a latent image formed on an image carrier in an image forming apparatus such as an electrophotographic copying machine or a printer, and more particularly, to a developer chamber. The present invention relates to a developing device having an improved developer remaining amount detection mechanism.

[0002]

2. Description of the Related Art Conventionally, as a method of detecting the remaining amount of toner in a toner chamber (toner hopper) of a developing device, a transparent window member is provided in the toner chamber, and the toner remaining amount is optically transmitted through the window member. There was a method of detecting

In order to reliably detect the remaining amount of toner by this method, it is necessary to appropriately clean the window member. As a cleaning method, a toner installed in the toner chamber for supplying toner to the developing chamber is used. It was common to use a stirring blade of a stirring member.

[0004]

By the way, conventionally, FIG.
As shown in FIG. 5, the optical detecting member 9 is configured to stir the optical path from the light emitted from the light emitting element 9a to the light receiving element 9b.
6 is disposed obliquely with respect to the toner chamber 2 so as to be displaced from the rotation center.

However, light emitted from the light emitting element 9a is reflected unless it is incident on the window members 17 and 18 at right angles, and the amount of light received by the light receiving element 9b decreases or becomes unstable, and the amount of toner remaining Causes false detection of The optical path of the detection member 9 needs to be close to the rotation center of the stirring member 16.

Therefore, as shown in FIG. 4, the optical path L of the optical detection member 9 is set in the vertical direction at a position as close as possible to the rotation center of the stirring member 16, and the window members 17 provided at the upper and lower positions of the toner chamber 2 are provided. , 18 are formed so as to be perpendicular to the optical path.

However, there is a limit to the approach of the optical path L to the center of rotation of the stirring member 16, and the window members 17, 18 are limited.
Cannot be provided near the center of the toner chamber 2, the window members 17, 18 are provided with stirring blades 16 at the tip of the stirring member 16.
It protrudes largely inside the locus of b. For this reason, the stirring blade 16b is likely to be deformed by hitting the window members 17 and 18, often causing a problem in the toner transportability.

An object of the present invention is to enable the optical path of the optical detection means to be positioned at the rotation center line of a developer stirring member provided in a developer chamber, to prevent a reduction in the amount of received light due to reflected light and to use a stirring member. An object of the present invention is to provide a developing device that achieves both good developer transportability.

[0009]

The above object is achieved by a developing apparatus according to the present invention. In summary, the present invention relates to a developer chamber for containing a developer, the developer chamber supplying a developer to a developing chamber provided with a rotatable developer carrier, and a developer chamber in the developer chamber. A rotatable stirring member that stirs, a first window member provided in the developer chamber and transmitting light emitted from a light emitting unit outside the developer chamber into the developer chamber, and provided in the developer chamber. A second window member that transmits the light from the developer chamber to the outside of the developer chamber so that the light can be received by a light receiving unit outside the developer chamber; and A developing device having a stirring blade for cleaning the first and second window members;
The surface of the window member is provided substantially orthogonal to an optical path from the light emitting unit to the light receiving unit, and the stirring member is configured to allow the optical path to pass through the rotation center line of the stirring member orthogonally. A developing device is provided with an opening in the rotation shaft.

According to one embodiment of the present invention, an amount of the developer in the developer chamber is detected according to a light receiving state of the light receiving unit.

[0011]

FIG. 1 is a sectional view showing an embodiment of the developing device according to the present invention, and FIG. 2 is a perspective view showing the vicinity of a toner chamber of the developing device.

As shown in FIG. 1 and FIG.
Reference numeral 0 denotes a developing chamber 1 and a toner chamber 2. A developing roller 3 is rotatably supported in the developing chamber 1, and a blade 4 for applying the toner to the developing roller 3 in a thin layer and applying a triboelectric charge to the toner. Are in contact with the developing roller 3. Developing room 1
Is provided with a supply roller 5 that supplies toner to the developing roller 3 by rotating while being in contact with the developing roller 3. A stirring member 6 is rotatably supported in the toner chamber 2.
The toner T accommodated therein is conveyed while being stirred, and supplied into the developing chamber 1 through the opening 2a.

The stirring member 6 includes a stirring stay 6a made of a sheet metal or the like extending in the direction of a center line 6d laterally protruding from the rotation center line 6d, and a center line 6d provided at the tip of the projecting portion of the stay 6a. And a stirring blade 6b that rubs the inner wall of the toner chamber 2 in the direction. The vicinity of the center of the stirring stay 6a also protrudes on the opposite side, and an opening 6c is provided so as to include the rotation center line 6d.

In the upper and lower walls of the toner chamber 2, window members 7 and 8 through which light can pass are provided near the center so as to be opposed surfaces passing through the opening 6c of the stirring stay 6a.

On the other hand, in the main body of the image forming apparatus, a light emitting element 9a and a light receiving element 9b constituting the optical detecting member 9 are supported at positions where the upper and lower window members 7, 8 can be transmitted. An optical path L from which the light emitted from 9a passes through the lower window member 8, the opening 6c of the stirring stay, and the upper window member 7 to the light receiving element 9b is formed.

The mechanism for detecting the remaining amount of toner in the developing device of this embodiment is configured as described above. According to this, when the amount of the toner T in the toner chamber 2 is large, even if the toner is cleaned from above the lower window member 8 by the stirring blade 9b of the stirring member 9, the window member 8 is immediately covered with the toner. Therefore, the light receiving element 9b is always in a light receiving disabled state. That is, it is detected that the toner is full.

When the amount of toner in the toner chamber 2 is gradually decreased, the time during which the toner is cleaned from the lower window member 8 and the light can be received becomes longer, and the time when the light can be received for a certain time or more becomes longer. And it is detected that there is no remaining toner, and it is notified as toner replenishment or cartridge replacement time.

At this time, in this embodiment, since the optical path L of the optical detection member 9 passes through the rotation center line 6d of the stirring member 6, even if the window members 7, 8 do not protrude from the locus of the stirring blade 6b, the window member 7, 8 can be formed at right angles to the optical path L. Therefore, the light from the light emitting element 9a can be transmitted almost completely, the remaining amount of toner in the toner chamber 2 can be detected satisfactorily, and the deformation of the stirring blade 6b can be prevented. Can be satisfactorily conveyed and supplied to the developing chamber 1.

[0019]

[0020]

[0021]

[0022]

[0023]

[0024]

[0025]

[0026]

As described above, the present invention is directed to a developer chamber for containing a developer, the developer chamber supplying a developer to a developer chamber provided with a rotatable developer carrier. A rotatable stirring member for stirring the developer in the developer chamber, a first window member provided in the developer chamber and transmitting light emitted from a light emitting unit outside the developer chamber into the developer chamber; A second window member that is provided in the chamber and transmits light from the developer chamber to the outside of the developer chamber so that light can be received by the light receiving unit outside the developer chamber. A developing device provided with a stirring blade for cleaning the second window member;
The surface of the window member is provided substantially orthogonal to the optical path from the light emitting means to the light receiving means, and the stirring member is opened to its rotation axis so that the optical path allows the light to pass through the rotation center line of the stirring member at right angles. The surfaces of the first and second window members are provided substantially orthogonal to the optical path from the light emitting unit to the light receiving unit, so that reflected light can be reduced, and the amount of light received by the reflected light can be reduced. The stirring member is provided with an opening in its rotation axis so that the reduction can be prevented, and the light path allows the passage of the stirring member at right angles to the rotation center line, so that the window member protrudes more than the rotation trajectory of the stirring member. Therefore, developer transportability can be improved. As described above, according to the present invention, it is possible to achieve both the prevention of a decrease in the amount of light received by reflected light and the good transportability of the developer by the stirring member.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of a developing device of the present invention.

FIG. 2 is a perspective view showing the vicinity of a toner chamber of the developing device.

FIG. 3 is a cross-sectional view illustrating an example of a toner remaining amount detection mechanism of a conventional developing device.

FIG. 4 is a cross-sectional view illustrating another example of a toner remaining amount detection mechanism of a conventional developing device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Developing room 2 Toner room 6 Toner stirring member 6a Stirring stay 6b Stirring blade 6c Opening 6d Rotation center line 7, 8 Window member 9 Optical detection member 100 Developing device L Optical path

Continuation of the front page (56) References JP-A-2-210479 (JP, A) JP-A-2-173527 (JP, A) JP-A-3-164768 (JP, A) JP-A-64-4778 (JP) , A) JP-A-2-116875 (JP, A) JP-A-1-316765 (JP, A) JP-A-6-266232 (JP, A) Fully open Hei 2-123955 (JP, U) Really open 61-109458 (JP, U) Patent 3110231 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 15/08-15/095

Claims (2)

(57) [Claims] 1. A developer chamber for storing a developer, wherein the developer chamber supplies a developer to a developing chamber provided with a rotatable developer carrier, and the developer is stirred in the developer chamber. A rotatable stirring member, a first window member provided in the developer chamber and transmitting light emitted from a light emitting unit outside the developer chamber into the developer chamber, and the light provided in the developer chamber. A second light transmitting the light from the developer chamber to the outside of the developer chamber so that the light can be received by the light receiving means outside the developer chamber.
And a stirring member, wherein the stirring member includes the first and second members.
In the developing device provided with a stirring blade for cleaning the window member, a surface of the first and second window members is provided substantially orthogonal to an optical path from the light emitting unit to the light receiving unit, and the optical path is The developing device according to claim 1, wherein the stirring member has an opening in a rotation axis thereof so as to allow the stirring member to pass through the rotation center line at right angles. 2. The developing device according to claim 1, wherein an amount of the developer in the developer chamber is detected according to a light receiving state of the light receiving unit.