JP2859335B2 - Developing device for electrophotographic equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to an electrophotographic apparatus, such as a printer, a copier, and a facsimile, which uses a laser to record on a recording sheet such as paper using an electrophotographic process. obtain. More specifically, the present invention relates to a developing device that visualizes a latent image on a photoconductor with toner in such an electrophotographic apparatus.

2. Description of the Related Art Conventionally, in a developing device of this type, a developing chamber 2 is divided into a developing case 1 as shown in FIG.
A developing roller 3 is provided therein, and a thinning member 4 is pressed against the developing roller 3 in parallel with its axial direction, and a wall 5 protruding into the developing chamber 2 is provided at an axial end of the developing roller 3.
And presses the seal member 6 to prevent toner leakage from its axial end. And the developing roller 3
, The toner is thinned by the thinning member 4, and the developing roller 3 is pressed against the photosensitive member 7 to visualize the latent image on the surface of the photosensitive member 7.

However, in the conventional developing device, the toner 8 that has fallen on the developing case 1 as shown in FIG.
Is collected at the back of the developing chamber 2 by the rotation of the developing roller 3. However, at both ends of the developing roller 3, it is interrupted by the wall 5 and is not collected. Then, there is a problem that over time, the developer overflows from the opening 1a of the developing case 1 and scatters to the outside, thereby contaminating the inside of the electrophotographic apparatus main body and adversely affecting image quality.

Accordingly, an object of the present invention is to prevent toner falling into the developing device from between the developing roller and the seal member from scattering outside the developing device, thereby contaminating the inside of the electrophotographic apparatus main body and reducing image quality. The purpose is to prevent adverse effects.

Means for Solving the Problems In order to achieve the above object, the present invention presses a thinning member from above onto a developing roller in a developing case, and, by using the thinning member, a rotational direction of the developing roller. At an upstream position, a seal member is pressed against an axial end of the developing roller, toner is attached to the surface of the developing roller by a toner replenishing member, and the attached toner is thinned by the thinning member. In a developing device of an electrophotographic apparatus for attaching a layered toner to visualize a latent image on a photoreceptor surface, the developing device is provided at a position upstream of the toner supply member in the rotation direction of the developing roller, At the lower side, between the developing case and the developing case, a toner collecting rod is provided in parallel with the developing roller for feeding toner to the inner side of the developing case by rotation. A screw portion for transporting the toner toward the axial center of the toner collection rod is provided at a position upstream of the wall supporting the roller member in the rotation direction of the developing roller.

Then, the toner around the screw portion is conveyed by the rotation of the toner collecting rod toward the center of the toner collecting rod in the axial direction by the screw portion, and then the toner is sent toward the interior of the developing chamber and collected.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 3 shows a laser printer provided with a developing device according to the present invention, and shows an overall schematic configuration of an internal mechanism thereof. In the figure, reference numeral 10 denotes an apparatus main body. A paper feed tray 11 is detachably attached to the right side of the apparatus main body 10 in the drawing. Paper tray
A recording sheet 12 such as paper is loaded and stored in the inside of the unit 11. The recording sheet 12 is sent out in the direction of arrow A by the paper feed roller 13, guided and conveyed by a guide plate or the like, and the leading end abuts between the pair of registration rollers 14 and temporarily stops there. Then, at a predetermined timing, it is sent out to a drum-shaped photoconductor 15 which is an image carrier.

The photoconductor 15 is driven by a driving device (not shown),
Rotate clockwise in the figure. At that time, the surface is uniformly charged by the charging charger 16, and then the surface is irradiated with laser light from the laser writing system 17 to form an electrostatic latent image thereon. Thereafter, when passing through the position of the developing device 18, the toner is adhered by the developing device 18 and the electrostatic latent image is visualized. The visible image is transferred to the photoreceptor at
Transfer sheet to the recording sheet 12
Transcribe by 19. The transferred recording sheet 12 is conveyed to a fixing device 20, where it is fixed by applying heat and pressure.
After fixing, the sheet is switched by the switching means 21 and sent out through the sheet transport path 22 to the face-down sheet discharge section 23 in the direction of arrow B, or directly as it is, in the face-up sheet discharge section in the direction C.
Send to 24.

On the other hand, the photosensitive member 15 after the transfer of the visible image
The remaining toner is removed by the cleaning blade 26 of 25, and the surface is cleaned. The removed residual toner is collected in a collection tank.
Send it to 27 and collect it there.

Incidentally, in the developing device 18 according to the present invention, a toner cartridge (not shown) is mounted on the developing case 28 as shown in FIG. Replenish toner 30. The toner supply chamber 29 of the developing case 28
Contains an agitator 31 and a toner replenishing roller 32, and a developing chamber 33 contains a developing roller 35 and the like. The agitator 31, the toner replenishing roller 32, the developing roller 35, and the like, which are toner replenishing members, respectively rotate in the direction of the arrow in the drawing, and the agitator 31 agitates the toner 30 in the toner supply chamber 29, and the agitated toner 30 With the toner supply roller 32 as the developing roller
Attaches to 35. At this time, the toner 30 is frictionally charged by the toner supply roller 32 and the developing roller 35 rotating in opposite directions. The developing roller 35 is urged by a compression spring 36 to press the tip of a blade-shaped thinning member 37. The toner attached to the surface of the developing roller 35 is regulated by the thinning member 37 to form a toner thin layer region 35a on the outer periphery of the developing roller 35. In addition, a sealing member 38 is supported and pressed against the axial end of the developing roller 35 by a wall 28b substantially halfway around the upstream side of the thinning member 37 to prevent toner leakage from the axial end. To prevent. The wall 28b protrudes into the developing chamber 30 integrally with the developing case 28. Then, the toner in the toner thin layer region 35a of the developing roller 35 is attached to the photoconductor 15, and the photoconductor 15
Is developed into a visible image. The developing device 18
The developing roller 35 is urged by urging means (not shown).
Is pressed against the photoconductor 15.

In the present invention, as shown in FIG. 1, a toner collecting rod is provided between the developing roller 35 and the developing case 28 below the developing roller 35.
40 is provided rotatably. The toner collecting rod 40 is an elongated rod slightly longer than the axial length of the developing roller 35, and is provided with a pair of screw portions 40b at both ends.
Protrude 0a. The screw portion 40b has a twist that is reversed left and right. Then, as shown in FIG. 2, the toner collecting rod 40 is pressed against the developing roller 35 in parallel with its axial direction, and the support shafts 40a at both ends are supported by the side wall 28a of the developing case 28. When the toner recovery rod 40 is rotated, the screw 40
As shown by arrows C and D, the toner around b can be conveyed toward the center in the axial direction of the toner collecting rod 40, that is, into the width (W) of the developing chamber 31.

When the developing device 18 is driven, the developing roller
Following the rotation of 35, the toner collecting rod 40 rotates. Then, the developing roller 35 and the sealing member 38 are
Is conveyed to the axially central portion of the toner collection rod 40. The transported toner is transferred to a toner collection rod 40.
The developer is fed toward the back of the developing chamber 31 and collected between the developing roller 35 and the developing roller 35.

In the present invention, the toner collecting rod 40 is configured to rotate with the rotation of the developing roller 35 in the above-described embodiment, but may be configured to transmit a driving force from a driving source (not shown) to rotate the toner collecting rod 40. .

As described above, according to the present invention, according to the present invention, the toner around the screw portion is conveyed toward the axial center of the toner collection rod, and the toner is sent toward the back of the developing chamber by the toner collection rod. , It is possible to prevent toner dropped from between the developing roller and the seal member from scattering outside the developing device, and to prevent the inside of the electrophotographic apparatus main body from being soiled or adversely affecting image quality. .

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a developing device according to the present invention, FIG. 2 is a sectional view of the developing device, and FIG. 3 is a schematic configuration diagram of an entire internal mechanism of a laser printer including the developing device.
FIG. 4 is a schematic configuration diagram of a conventional developing device. 15 photoreceptor 18 developing device 31 developing chamber 35 developing roller 35a toner thin layer region 37 thinning member 38 sealing member 40 toner collecting rod 40b screw portion

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Claims (1)

(57) [Claims] And a sealing member which is pressed against a developing roller in a developing case from above, and which is provided at an axial end of the developing roller at a position upstream of the developing roller in a rotation direction of the developing roller. Is pressed, toner is attached to the surface of the developing roller by a toner replenishing member, and the attached toner is thinned by the thinning member.
A developing device of an electrophotographic apparatus for visualizing a latent image on a photoreceptor surface by attaching the thinned toner, wherein the developing device is located upstream of the toner supply member in a rotation direction of the developing roller, A toner collecting rod provided between the developing roller and the developing case at a position parallel to the developing roller, the toner collecting rod being configured to send toner to the inner side of the developing case by rotation; A developing device for an electrophotographic apparatus, further comprising: a screw portion that conveys toner toward an axial center of the toner collecting rod at a position upstream of a wall supporting the member in a rotation direction of the developing roller.