JPH0411264A - Developing device for electrophotographic copying device - Google Patents

Abstract

PURPOSE:To prevent toner from spilling from a developing roller window by moving a shutter to a 1st position where it closes the developing roller window by interlocking with an action for detaching a developing device when the developing device is detached in the case of maintenance. CONSTITUTION:When the developing device is pushed in at the time of attachment, an engaging part 54a is engaged with a part 55 to be engaged to move the shutter 53, a 2nd link 51 is turned, and a 1st link 47 is turned against energizing force. When the device is completely pushed in, the engaging part 54a is moved to a terminating position to move the shutter 53 to a 2nd position where it opens the developing roller window. Meanwhile, when it is pulled out at the time of maintenance, the 1st link 47 is turned based on the energizing force to draw the 2nd link 51 and the shutter 53 is moved in the moving direction of the 2nd link 51. When it is completely pulled out, the engaging part 54a is restored to a starting position to move the shutter 53 to the 1st position where it closes the developing roller window. Thus, the toner is prevented from spilling from the developing roller window in the case of detaching the developing device 14.

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial - ΩII Rikome 1 This invention uses a laser. The present invention can be applied to electrophotographic devices such as printers, copying machines, and facsimiles that perform recording on a recording medium such as paper using an electrophotographic process. 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.

Obedience! l wound 1 Conventionally, this type of developing device is equipped with a developing roller.

The developing roller is pressed against the photoconductor through the development roller window and rotates together with the photoconductor, thereby depositing toner and visualizing the latent image on the surface of the photoconductor. Incidentally, the developing device, which is a consumable item, needs to be replaced periodically, and is removably installed within the main body of the apparatus. During maintenance, when installing or removing equipment,
The developing roller was left exposed.

For this reason, conventionally, with this type of developing device, when the developing device is removed from the main body of the device, toner spills from the developing opening/opening window and stains hands and clothes with the toner. there were.

SUMMARY OF THE INVENTION An object of the present invention is to prevent toner from spilling out of the developing roller window when the developing device is removed and staining hands and clothes with the toner.

In order to achieve the above object, the present invention has a developing roller that is replaceably housed in an apparatus main body, is pressed against a photoreceptor through a developing roller window, and toner is attached to the photoreceptor. In a developing device of an electrophotographic apparatus that visualizes a latent image on the surface of a photoconductor, a biasing member, a first link biased in one direction by the biasing member, and one end of the first link are rotated. comprising a second link that is freely connected, and a shutter that is rotatably connected to the other end of the second link and held in a first position that closes the developing roller window based on the urging force of the urging member;
When it is attached, it engages with the engaged part in the device main body, when it is pushed in, it moves the shutter against the biasing force of the biasing member, and when it is completely pushed in, it moves to a terminal position and the shutter is moved. The shutter is characterized in that the shutter includes an engaging portion that moves to a second position that opens the developing roller window.

Operation When the shutter is pushed in, the engaging portion engages with the engaged portion and the shutter is moved. Then, the second link rotates, and the first link further rotates against the applied force. When the shutter is fully pushed in, the engaging portion moves to the final position and moves the shutter to the second position where the developing roller window is opened.

On the other hand, when it is pulled out during maintenance, the first link rotates based on the urging force and pulls the second link. Then, the shutter moves in the direction of movement of the second link. When it is completely pulled out, the engaging portion returns to the starting position and moves the shutter to the first position where it closes the developing roller window.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the following, embodiments of the present invention will be described with reference to the drawings.

FIG. 5 shows a laser printer equipped with a developing device according to an embodiment of the present invention, and is a schematic diagram of the overall structure of its internal mechanism. The reference numeral 10 in FIG. 5 is the apparatus main body. 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.

Around the photoreceptor 12, a charger 13, a developer 14, . A transfer device 15 and a cleaning device 16 are arranged. 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.

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 at a timing controlled by a pair of registration rollers 21. The photoreceptor 12 is rotated counterclockwise as shown by the arrow, and at this time, the surface is uniformly charged by the charger 13.
The photoreceptor 12 is irradiated with laser light from the optical writer 18.
forming an electrostatic latent image thereon. 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 transferred to a paper ejection roller 24.
The paper is conveyed to the paper discharge section 25 by the paper discharge guide 26 and stacked on the paper discharge tray 27.

The developing device according to the present invention, as shown in FIG. 4, has a typical developing frame 30 as a whole, and the developing frame 30 includes an optical component 31 that transmits the laser beam through the charger 13. The developing device 14 is integrally supported to form a unit. The entire unit is removably installed within the lower structure 10b of the apparatus main body 1O. The charger 13 is placed on the opposite side of the developer 14 across the optical path of the laser beam.

The optical component 31 is disposed on the optical path with the open end of the second CY lens 31a supported by the engaging portion 31b. The engaging portion 31b has a U-shape and is integral with the developing section frame 30. The developing device 14 includes a developing chamber 34 therein, has a developing roller window 35 open on the side of the photoreceptor 12, and has a toner supply port 36 opened on the side opposite to the developing roller window 35. The developing chamber 34 is provided with a developing roller 37, a toner supply roller 38, a thin layer blade 39, and a static elimination brush 40. The developing roller 37 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 . A toner cartridge 42 is integrally connected to the developing device 14 by heat welding or the like on the side of the toner replenishment slot 36, and the opening 4
2a and the toner supply port 36 are connected. The toner cartridge 42 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 is replenished into the developing chamber 34 while agitating the toner 43. As the developing roller 37 rotates clockwise as indicated by the arrow, the toner replenishing roller 38 also rotates clockwise to frictionally charge the toner 43 and adhere to the developing roller 37 . The attached toner 43 is stopped at the tip of the thin layer blade 39 to form a thin layer. Then, the developing roller window 3
5 to the photoreceptor 12 against which the developing roller 37 is pressed.
Toner 43 is attached to make the latent image on the surface of the photoreceptor 12 visible.

Now, the developing device 14 of the present invention is specifically constructed as shown in FIGS. 1 and 2. A first link 47 is rotatably attached to the outer surface of the side plate 30a of the developing frame 30 with a support shaft 48. The first link 47 has one end of the biasing member 49 hooked thereto to bias it in one direction, and one side of the other end abuts against the stopper 50 . The stopper 50 projects outward from the side plate 30a. Said first link 47
One end of the second link 51 is rotatably connected to the other end with a pin 52. The second link 51 has an inverted upside-down shape, and its other end is rotatably connected to both sides of the rear end of the shutter 53 with pins 54 . At approximately the center of the second link 51, a convex portion 51a is protruded outward. The protrusion 51a engages with a protruding piece 53a of the shutter 53. The shutter 53 is a rectangular flat plate that broadly covers the developing roller window 35 and its surrounding area, and is at a first position where the developing roller window 35 is closed. The shutter 53 is provided with bent portions 53b facing downward on both sides, and the protruding piece 53a is integrally provided at the rear end of the bent portions 53b. On both sides of the rear end of the bent portion 53b, an engaging portion 54 is formed by protruding the aforementioned pin 54 outward.
Provide a.

When the above-mentioned developing device 14 is installed in the apparatus main body 10, the engaging portion 54a engages with the engaged portion 55 in the apparatus main body 1o, as shown in FIG. When pushed in the direction of arrow B shown in FIG. 2, the shutter 53 is moved and the second link 51 is rotated clockwise about the pin 52. As the rotation of the second link 51 progresses, the first link 47 is pulled. Then, the first link 47 rotates clockwise about the support shaft 48 against the biasing force of the biasing member 49. Then, when it is completely pushed in, the engaging portion 54a
moves to the final position and the shutter 5
3 to the second position where the developing roller window 35 is opened.

On the other hand, when the developing unit 14 is pulled out from inside the apparatus main body 10 during maintenance, the first link 47 is rotated counterclockwise about the support shaft 48 by the urging force of the urging member 49, and the second link 47 is rotated counterclockwise around the support shaft 48.
The shutter 53 is returned via the link 51. When fully pulled out, the first link 47 hits the stopper 50 and the second link 47 hits the stopper 50.
The link 51 is rotated around the pin 52 to connect the engaging portion 54.
At the same time, as shown in FIG. 1, the shutter 53 is moved to the first position where it closes the developing roller window 35 and is held by the biasing force of the biasing member 49.

From the above, according to the developing device according to the present invention, when the 1gA device is removed during maintenance, the shutter is moved to the first position that blocks the developing port window in conjunction with the removal operation. Since it moves, it is possible to prevent toner from spilling out of the developing roller window, and it is possible to prevent toner from adhering to hands, fingers, and clothing. Further, since the shutter is opened and closed by a link mechanism including the first link and the second link, the shutter can be opened and closed in a small space.

[Brief explanation of drawings]

FIG. 1 is a perspective view of the main parts of a developing device according to an embodiment of the present invention, FIG. 2 is a side view thereof, FIG. 3 is an explanatory diagram of the state in which the developing device is installed, and FIG. FIG. 5 is a partially enlarged view of a laser printer with a developing device attached thereto, and is a schematic diagram of the entire internal mechanism of the laser printer. 10......Device body, 12......
...Photoreceptor, 14...Developer, 35...
......Developing roller window, 37...Developing roller, 47...First link, 49.
......Biasing member, 51......Second
Link, 53... Shutter, 54a...
. . . Engaging portion, 55 . . . Engaged portion. 54a (54) 53a) l

Claims (1)

[Scope of Claims] The developing roller is replaceably housed in the main body of the apparatus, and the developing roller is pressed against the photoreceptor through the developing roller window, and toner is adhered to the photoreceptor to visualize the latent image on the surface of the photoreceptor. A developing unit for an electrophotographic apparatus includes a biasing member, a first link biased in one direction by the biasing member, a second link rotatably connecting one end of the first link, and a second link rotatably connecting one end of the first link. a shutter that is rotatably connected to the other end of the two links and held in a first position that closes the developing roller window based on the biasing force of the biasing member; When pushed in, the shutter moves against the biasing force of the biasing member, and when fully pushed in, it moves to a final position and moves the shutter to a second position where the developing roller window is opened. 1. A developing device for an electrophotographic apparatus, characterized in that the shutter has an engaging portion for engaging the shutter.