JPH062366U - Development device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a developing device capable of performing development without imparting compression set to a developer carrying member and thereby uniformizing a developer layer or a developing electric field. [Structure] The developing roller 5 is arranged so as to be movable up and down, and the developing roller 5 is connected to the developer supply roller 4 by a guide 13. During development, the developer supply roller 4 rotates clockwise, and the guide 13 rotates clockwise around the shaft of the developer supply roller 4 to collide with the stopper 14 and stop. The developer supply roller 4 rotates counterclockwise, and the guide 13 rotates counterclockwise to collide with the stopper 15 and stop except during development. At this time, the developing roller 5
Is not pressed by the developer supply roller 4, the blade member 6, and the photoconductor drum 7.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention forms a developer layer on the surface of a developer carrier, and develops it in a copier, a printer, a facsimile, etc., in which the developer layer is made to face the electrostatic latent image carrier by a pressure developing method for development. Regarding the device.

[0002]

[Prior art]

 A blade member is provided on the developer carrying member of the developing device, and the blade member makes the developer layer formed on the surface of the developer carrying member uniform. Since the blade member applies a pressing force to the developer carrying member by the spring, maintaining this state for a long time gives a compression set to the developer carrying member. Due to the compression set, recesses are formed on the surface of the developer carrying member, which makes the developer layer non-uniform or the development electric field non-uniform, which adversely affects the developed image.

In order to prevent this, in the developing device in which the stopper for fixing the spring of the blade member is configured to be movable, the stopper is moved to carry the developer of the blade member except during development. A proposal has been made to reduce the pressing force on the body (Japanese Patent Laid-Open No. 2-259783).

[0004]

[Problems to be solved by the device]

 However, a developer supply roller for supplying the developer to the developer carrier is located immediately upstream of the developer carrier, and an electrostatic latent image is carried immediately downstream of the developer carrier. The electrostatic latent image carrier is located there, and in the pressure developing method, these are pressed against each other and rotate in conjunction with each other. In the developing device as described above, the pressing force from the blade member to the developer carrying member is reduced, but the pressing force from the developer supply roller and the electrostatic latent image carrying member cannot be reduced. In order to prevent this, it is necessary to use a material having a high hardness for the developer carrying member, which has a problem that there is a limit.

The present invention has been made in view of the above circumstances, and releases the developer bearing member from the pressing force of the blade member, the developer supply roller, and the electrostatic latent image bearing member except during development. By doing so, it is an object of the present invention to provide a developing device which does not give a compression set to a developer carrying member and thereby makes it possible to develop a developer layer or a developing electric field uniformly.

[0006]

[Means for Solving the Problems]

 In the developing device according to the present invention, the developer supply roller, the developer carrying member, and the electrostatic latent image carrying member are interlockedly rotated to the electrostatic latent image carrying member, and the blade member is pressed to the developing agent carrying member. In a developing device for pressing a formed developer layer to perform development, the developer carrying member is movably arranged in connection with the developer supply roller, and the electrostatic latent image carrying member and the blade are provided. The feature is that it can be separated from the members.

[0007]

[Action]

 In the developing device of the present invention, at the time of development, the developer supply roller, the developer carrying member and the electrostatic latent image carrying member are pressed against each other and rotate in conjunction with each other. Since the developer carrying member is movably arranged, the developer carrying member is moved away from the electrostatic latent image carrying member and the blade member except during development to release them from their respective pressures. Since the developer carrier and the developer supply roller are connected so that the longest distance is in contact with each other, the position of the developer carrier is determined by the rotation direction of the developer supply roller.

[0008]

【Example】

 Hereinafter, the present invention will be specifically described with reference to the drawings showing an embodiment thereof. FIG. 1 is a schematic side view of a developing device for developing by the pressure developing method of the present invention. In the figure, reference numeral 1 denotes a developer container, which contains a one-component developer 2. An agitator 3 is arranged at the bottom of the developer container 1, and the developer 2 is agitated by its rotation. A developer supply roller 4 and a developing roller 5 as a developer carrying member are arranged in the opening at the lower end of the developer container 1. When developing is performed, the developer supply roller 4 rotates clockwise, and the developer 2 drawn out from the developer container 1 is supplied to the development roller 5. A blade member 6 is disposed on the upper side of the developing roller 5 which rotates counterclockwise with its one end fixed, and is supplied by pressing the surface of the blade member 6 onto the surface of the developing roller 5 with a spring. The developer 2 is regulated so that a uniform developer image is formed on the surface of the developing roller 5.

A photosensitive drum 7, which is an electrostatic latent image carrier, is provided downstream of the developing roller 5. Above the photoconductor drum 7, there are arranged a charger 8 for giving an electric charge to the photoconductor drum 7 and an exposure device 9 for exposing an image to be formed. The photoconductor drum 7 rotates clockwise. , Its surface is charged by the charger 9, and the image to be formed by the exposure device 8 is carried as an electrostatic latent image. Then, the developer 2 is supplied onto the electrostatic latent image by pressing the developing roller 6, so that the electrostatic latent image is visualized. A transfer device 10 for transferring the electrostatic latent image onto the recording paper is provided below the photosensitive drum 7, and the image to be formed is transferred onto the recording paper by the transfer device 10.

A waste developer container 11 and a cleaning blade 12 are disposed on the downstream side of the photosensitive drum 7, and the cleaning blade 12 removes the untransferred developer 2 from the surface of the photosensitive drum 7. To the waste developer container 11.

FIG. 2 is an enlarged perspective view of the developer supply roller 4, the developing roller 5, the blade member 6, and the photosensitive drum 7 of this developing device. The developer supply roller 4, the development roller 5, and the photosensitive drum 7 are continuously rotated by gears (not shown), and are driven from the developer supply roller 4 side. The developing roller 5 is arranged so as to be vertically movable. As described above, the developing roller 5 receives a pressing force from the developer supply roller 4, the blade member 6, and the photoconductor drum 7 in order to form an image by the pressure developing method.

The developing roller 5 is connected to the developer supply roller 4 by a guide 13. The guide 13 is an oval flat plate having a hole 13a and a long hole 13b. The shaft of the developer supply roller 4 is fitted and fixed in the hole 13a, and the shaft of the developing roller 5 is inserted in the long hole 13b. Further, cylindrical rod-shaped stoppers 14 and 15 are fixed to the developing device so that they are located above and below the guide 13, respectively.

FIG. 3 is a schematic side view of each roller during development, and FIG. 4 is a schematic side view of each roller during development. As shown in FIG. 3, at the time of development, the developer supply roller 4 rotates clockwise and the developing roller 5 rotates counterclockwise. In this state, the developing roller 5 receives an upward force to move, the shaft of the developing roller 5 gives an upward force to the guide 13, and the guide 13 rotates clockwise around the shaft of the developer supply roller 4. Then, it collides with the stopper 14 and stops. At this time, when the photosensitive drum 7 is an aluminum tube and the developer supply roller 4 is an elastic body, the pressing force from the photosensitive drum 7 is strong, and the developing roller 5 moves toward the developer supply roller 4 side. The shaft is pushed and stops at the developer supply roller 4 side of the long hole 13b. Since the respective members apply a pressing force to each other, the shaft of the developing roller 5 does not move in the long hole 13b.

Then, as shown in FIG. 4, the developer supply roller 4 is rotated counterclockwise except during development. This causes the developing roller 5 to rotate clockwise. In this state, the developing roller 5 receives a downward force to move, and the shaft of the developing roller 5 gives a downward force to the guide 13. The guide 13 rotates counterclockwise around the shaft of the developer supply roller 4, collides with the stopper 15, and stops. At this time, the developing roller 5 is separated from the blade member 6 and the photosensitive drum 7, and is released from the pressing force of them. Further, the shaft of the developing roller 5 moves to the side of the photosensitive drum 7 in the elongated hole 13b and stops at a position where it comes into contact with the developer supplying roller 4. As a result, the pressing force of the developer supply roller 4 is also released. In this state, the rotation of the developer supply roller 4 is stopped. As described above, the developing roller 5 receives no pressing force from the developer supply roller 4, the blade member 6, and the photosensitive drum 7 except during the development.

When developing again, the developer supply roller 4 is again rotated clockwise as shown in FIG. As a result, the developing roller 5 rotates counterclockwise, and the shaft of the developing roller 5 applies an upward force to the guide 13. The guide 13 rotates clockwise around the shaft of the developer supply roller 4 and collides with the stopper 14 to stop. Then, as described above, development is performed by the pressure development method.

[0016]

[Effect of device]

 As described above, in the developing device of the present invention, the developer carrier does not receive the pressing force from the developer supply roller, the electrostatic latent image carrier and the broad member except during the development. The present invention has an excellent effect such that the developer layer or the development field can be made uniform and development can be performed without applying compression set to the above.

[Brief description of drawings]

FIG. 1 is a schematic side view of a developing device for developing by a pressure developing method of the present invention.

FIG. 2 is an enlarged perspective view of the developer supply roller, the developing roller, the blade member, and the photosensitive drum of the developing device of the present invention.

FIG. 3 is a schematic side view of each roller during development of the present invention.

FIG. 4 is a schematic side view of each roller of the present invention other than during development.

[Explanation of symbols]

 1 Developer Container 2 Developer 4 Developer Supply Roller 5 Development Roller 6 Blate Member 7 Photosensitive Drum 11 Waste Developer Container 13 Guide 13a Hole 13b Long Hole 14,15 Stopper

Claims (1)

[Scope of utility model registration request] 1. Development that is formed on the developer carrying member by pressing a blade member against the electrostatic latent image carrying member by interlocking rotation of a developer supply roller, a developer carrying member, and an electrostatic latent image carrying member. In a developing device for pressing a developer layer to perform development, the developer carrying member is movably arranged in connection with the developer supply roller, and can be separated from the electrostatic latent image carrying member and the blade member. A developing device that is configured.