JPS62237476A - Developing device - Google Patents

Abstract

PURPOSE:To obstruct a rotary sleeve from turning in other direction than the normal direction, and to prevent a toner from overflowing between said sleeve and a photosensitive body, by providing a backlash exceeding a turning angle of an engagement at the time of attaching and detaching operations, between a driving transfer gear of a revolving shaft of the rotary sleeve for constituting a developing roller, and a driving input system gear of an image forming device body. CONSTITUTION:A developing mechanism part 40 of a developing device body 30 engages a driving transfer gear 75 to a driving input system gear 74 for rotating unitedly with a driving gear 71 which has been installed to an image forming device body 1 side through an idler 94, at the time of attachment and detachment. In this case, a turning angle theta1 of the rotating driving transfer gear 75 is set so as to become smaller than a turning angle theta2 due to each backlash between a revolving shaft 46 of a rotary sleeve 43, and the driving transfer gear 75 (theta1<=theta2). Accordingly, at the time of installation in the X direction, even if said driving transfer gear 75 rotates in reverse in the A direction, the revolving shaft 46 of the rotary sleeve 43 can maintain a static state so that it does not rotate in reverse.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a developing wit installed in an image forming apparatus such as an electronic copying apparatus.

(Prior Art) Conventionally, in this type of image forming apparatus such as an electronic copying apparatus, as shown in FIGS. 13 and 14, a developing device main body 30 has a lower casing unit 31 and an upper casing unit 32. The developing mechanism section 40 and the developer agitating section 5 are assembled into one piece, and are disposed within the lower casing unit 31.
0 built-in, and in the loading space 61 formed in the upper casing unit 32 of the developing device main body 30.

A toner cartridge 80 containing a developer (hereinafter referred to as toner) is removably loaded therein.

The developing device main body 30 as described above is removably installed in the storage space of the image forming apparatus, and the developing roller 4 of the developing mechanism section 40
1 is positioned opposite to a photoreceptor 10 which is an image carrier.

The developing roller 41 is a magnetic roll 42 having a plurality of magnetic pole parts.

The rotating sleeve 43 is fitted around the magnetic roll 42 and rotates in a direction opposite to the rotational direction of the photoreceptor 10. The brush D is brought into sliding contact with the electrostatic latent image formed on the photoconductor 1o in a direction that follows the movement of the electrostatic latent image to perform the development process. A doctor 44 for regulating the thickness of the developer magnetic brush D is installed on the side.

Further, the developer stirring unit 50 includes first and second bladed stirring rolls 51 and 52 disposed on the side of the toner supply port 33.
The first bladed stirring roll 51 reciprocates and stirs the toner T sealed in the lower casing unit 31 along the axial direction of the developing roller 41.
The bladed stirring roll 52 uniformly mixes the toner T newly supplied from the toner supply port 33.

On the other hand, the developing roller 41 has a gear provided on the rotational drive shaft side (not shown) of the rotating sleeve 43 engaged with a gear 74 that rotates in synchronization with a drive gear 71 of a replenishment drive mechanism 70 installed on the image forming apparatus main body 1 side. The drive is controlled in conjunction with the alignment.

However, in the driving force transmission means of the replenishment drive mechanism 70 installed on the image forming apparatus main body 1 side to the developing device main body 30 in such a conventional structure, the rotating sleeve 43 of the developing roller 41 has a structure that allows reverse rotation. This is the current situation.

(Problem to be Solved by the Invention) For this reason, as shown in FIG. The sleeve 43 rotates in the reverse direction A, and the toner T is transferred to the doctor 44.

It accumulates in front, and in this state, as shown in Figure 14,
When performing the developing operation, rotate the rotating sleeve 43 in the normal direction B.
If the photoreceptor 10 is rotated, there is a problem that the toner T is likely to overflow between the photoreceptor 10 and the like.

The present invention has been made under the above circumstances, and an object of the present invention is to provide a developing roller that reliably prevents reverse rotation of a developing roller in a power transmission section when being attached to and detached from an image forming apparatus. The goal is to provide equipment.

[Structure of the Invention] (Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides a system for transmitting a document image placed on a document table of an image forming apparatus main body through an optical system. Rotation of a developing roller which is removably engaged with the yjA dynamic input system gear of the image forming apparatus main body and interlocked with the electrostatic latent image formed on the uniformly charged image carrier. In a developing device in which developer is supplied and adhered to a developing device using a transmission drive means using a sleeve, an attachment/detachment operation to the drive input system gear of the image forming apparatus main body is performed between the rotation sleeve and the drive transmission gear of the rotation shaft thereof. The rotational sleeve is configured to have a play greater than the rotational angle of engagement during rotation, and to be able to prevent rotation of the rotating sleeve in a direction other than the normal direction.

(Function) That is, by having the above configuration, the present invention has the following features:
The drive transmission gear of the rotating shaft of the rotating sleeve constituting the developing roller and the drive input gear of the main body of the image forming apparatus are provided with play greater than the engagement rotation angle during attachment/detachment operation, so that the rotational sleeve is adjusted to its normal position. This is because it prevents rotation in any direction other than direction.

The developing roller does not rotate in reverse when it is attached or detached.

This makes it possible to reliably prevent toner from overflowing between the toner and the photoreceptor.

(Embodiment) An embodiment of the present invention will be described in detail below with reference to the drawings shown in FIGS. 1 to 12. In the illustrated embodiment of the present invention, the same reference numerals will be used to describe the parts that have the same structure in the attachment ring portion of the conventional developing device body shown in FIGS. 13 and 14 to the image forming apparatus. FIG. 1 shows the external appearance of an electronic copying apparatus which is an image forming apparatus equipped with a developing device according to the present invention, and numeral 1 in the figure is the main body of the copying apparatus. A paper feed cassette 2 capable of automatic or manual paper feeding is mounted on the right side of the copying apparatus main body 1, and a paper discharge tray 3 is mounted on the left side.

A document table 4 that is movable back and forth in the left-right direction (direction of arrow a) is provided on an upper document placement plate on which a document (not shown) is placed. Note that 5 in the figure is an operation display section provided on the front edge of the upper surface of the copying apparatus main body 1, including a display 6, a numeric keypad 7,
It consists of an exposure setting volume 8, a print key 9, etc.

Next, the internal mechanism of the copying apparatus main body 1 will be explained with reference to FIG.

In the figure, reference numeral 10 denotes a drum-shaped photoreceptor as an image carrier rotatably supported approximately at the center of the main body 1 of the copying apparatus.
It can be rotated in the direction of the arrow in synchronization with the document table 4 by a drive mechanism (not shown). The photoreceptor 10 is uniformly charged by a charging charger 11, and an original image irradiated by an exposure lamp 12 is transferred onto the photoreceptor 10 by a focusing light transmitter (Selfoc lens array) 13 constituting an optical system device. An electrostatic latent image is formed by forming an image, and toner T is supplied and adhered to this electrostatic latent image by a developing device main body 30, which will be described later, to develop it.

This developer image (hereinafter referred to as a toner image) is sent to the transfer charger 14 side.

The transfer charger 14 transfers a toner image onto copy paper P made of plain paper as recording paper fed from a paper feed cassette 2 that is automatically or manually fed via a paper feed roller 15 and a pair of registration rollers 16 and 16. After the transfer, the copy paper P is peeled off from the photoreceptor 10 by a peeling charger 17 using AC corona discharge, passed through a conveyance path 18, and the toner image is melted and fixed by a fixing device 19, and transferred to a discharge roller pair. 20. On the other hand, the paper is discharged onto the paper discharge tray 3 by 20.

Photoreceptor 10 after transfer and peeling of toner image onto copy paper P
The residual toner on the photoreceptor 10 is cleaned by a cleaning device 21, and the electric potential on the photoreceptor 10 is lowered to a certain level or less by a static elimination lamp 22 to make the next copying operation possible.

Further, in the upper surface portion of one side corresponding to the lower surface of the document table 4 of the copying apparatus main body 1, there is a storage space which becomes a mounting portion of a developing device main body 30, which will be described later and is mounted so as to face the photoreceptor 10. 100 is formed, and this storage space 1
A protective cover 101 is provided on the upper opening side of 00 so as to be openable and closable.

The developing device main body 30 has a structure as shown in detail in FIGS. 3 to 7.

That is, this developing device main body 30 is formed by assembling and integrating a lower casing unit 31 and an upper casing unit 32, and the lower casing unit 31 includes a built-in Tfi image mechanism mechanism section 40 and a developer stirring section 50. ing.

As shown in FIG. 3, the developing mechanism section 40 includes a developing roller 41 facing a first opening 31a of the lower casing unit 31 facing the photoreceptor 10 side. The developing roller 41 includes a magnetic roll 42 having a plurality of magnetic pole parts, and a rotating sleeve 43 that is fitted around the magnetic roll 42 and rotates in a direction opposite to the rotational direction of the photoreceptor 10. This rotary sleeve 43 develops by sliding the developer magnetic brush D attached to its surface in a direction that follows the movement of the electrostatic latent image formed on the photoreceptor 10. This is the so-called "with mode" in which processing is performed. Then, on the upper surface side of the developing roller 41.

A doctor 44 is installed to regulate the thickness of the developer magnetic brush D, and the developer magnetic brush D whose thickness is regulated by the doctor 44 is smoothed by a thin plate member 45.

Further, the developer stirring section 50 includes first and second bladed stirring rolls 51 and 52 facing oppositely to the second opening 31b opened at the upper part of the lower casing unit 31, which serves as a toner supply port. Equipped with.

The first bladed stirring roll 51 stirs the toner by reciprocating along the axial direction of the toner Ttil-developing roller 41 enclosed in the lower Kerrang unit 31, and the second bladed stirring roll 52 , the 1-toner T newly supplied from the second opening 31b serving as the toner supply port is uniformly mixed.

On the other hand, the above-mentioned upper casing unit 32.

It has a loading space 61 having a hopper-like cross-sectional shape.

The lower casing unit 31 is disposed at the inner bottom of the lower casing unit 31.
An opening 32a corresponding to the second opening 31b is opened, and a toner supply port 33 is formed by these openings 31b and 32a.

In the loading space 61, a toner cartridge 80 having a structure to be described later and having a toner T sealed therein is removably loaded from above in a cassette manner. Mouth 8
A supply roller 82 is installed near 1.

This toner cartridge 80 has both ends of a rotating shaft 83 of the supply roller 82 projecting to the outside, and a gear 84 of this rotating shaft 83 is attached to a drive side that meshes with a drive gear 68 of a drive system to be described later. The end portion 83a is
As shown in the figure, the clip-shaped shaft support 63 provided on one side wall of the loading space 61 is elastically fitted in the same way as in the conventional structure, and as shown in FIG. 84 is meshed with a drive gear 68 driven by a replenishment drive mechanism 70, which will be described later. The drive is controlled by a detection signal from the device 69.

That is, as shown in FIG. 6, the replenishment drive mechanism 70 described above is composed of a driven gear 73 to which the driving force of a driving gear 71 is transmitted via a clutch 72, and the toner cartridge is connected to the driven gear 73. A drive gear 6, which is a means for transmitting the driving force of the developer replenishment mechanism, meshes with a gear 84 attached to the drive side end 83a of the supply roller rotation shaft 83 of 80.
A drive signal to the clutch 72 is sent in response to a detection signal from the developer concentration detector 69.

Further, a drive transmission gear 75 and a first . Second
The rotational driving force is transmitted to the gear groups 76 and 77 of the developer stirring rollers 51 and 52, as shown in FIG. It is designed to mesh with and interlock with the drive input system gear 74.

Further, as shown in FIG. 8, the rotating shaft 46 of the rotating sleeve 43 and the drive transmission gear 75 that constitute the developing roller 41 of the developing mechanism section 40 have a certain amount of backlash (play) in their rotational directions. Protrusions 91,92 to occur relatively
The drive transmission gear 75 is regulated in such a way that the drive transmission gear 75 can always be biased in the normal rotation direction B by the biasing force of the coil spring 93.

That is, the developing mechanism section 40 of the developing device main body 30 is as follows:
As shown in FIGS. 9 and 10, first, when installed, the drive input system rotates the drive transmission gear 75 integrally with the drive gear 71 installed on the image forming apparatus main body 1 side via an idler 94. The rotation angle θ1 of the drive transmission gear 75 that rotates when meshing with the gear 74 is smaller than the rotation angle θ2 due to the mutual play between the rotation shaft 46 of the rotating sleeve 43 and the drive transmission gear 75. It is set so that (θ, ≦02), and by this,
Even if the drive transmission gear 75 reverses in six directions when mounted in the X direction, the rotating shaft 46 of the rotary sleeve 43 can maintain a stationary state so as not to rotate in reverse. Further, when the developing device main body 30 is removed from the attached portion 100 of the image forming device main body 1 in the Y direction, as shown in FIGS. 11 and 12, the normal rotation direction of the drive transmission gear 75 is This allows the rotating shaft 46 of the rotating sleeve 43 to rotate following the rotation toward B.

It should be noted that the present invention is not limited to the above embodiments, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

[Effects of the Invention] As is clear from the above description, according to the present invention, there is a gap between the drive transmission gear of the rotating shaft of the rotating sleeve in the developing roller and the drive input gear of the main body of the image forming apparatus during the attachment/detachment operation. By providing play greater than the engagement rotation angle,
Since the rotating sleeve is prevented from rotating in any direction other than the normal direction, the developing roller does not rotate in the opposite direction when attaching and detaching as in the conventional case, which reliably prevents toner from overflowing between it and the photoreceptor. Therefore, it is possible to provide a developing device that has excellent effects such as:

[Brief explanation of drawings]

FIG. 1 is an external perspective view showing an embodiment of an electronic copying apparatus as an image forming apparatus using the developer replenishing device according to the present invention, FIG. 2 is a schematic cross-sectional view showing the internal structure, and FIG. 4 to 7 are explanatory diagrams showing the main parts of the developing device main body, and FIG. 8 is a drive of the rotating sleeve of the developing roller in the developing device main body of the present invention. An exploded perspective view schematically showing the transmission part, FIGS. 9 and 10 are explanatory views of main parts schematically showing the rotating state of the drive transmission part when installed, and FIGS. 11 and 12 are similar views when it is removed. FIGS. 13 and 14 are schematic cross-sectional views showing how the developing device main body is attached to a conventional electronic copying device. 1... Image forming apparatus main body, 4... Original table. 10... Image carrier, 13... Optical system, 3
0...Developing device main body. 41... Developer roller, 43... Rotating sleeve, 46... Rotating shaft, 70
...Replenishment drive mechanism. 74°...Drive input system gear, 75...Drive transmission gear, 91.92...Protrusion, 93...Coil spring, θ,...Rotation angle when attaching/detaching the drive transmission gear. 02
... Rotation angle due to mutual play between the rotating shaft of the rotating sleeve and the drive transmission gear. T...Developer. Applicant's representative Patent attorney Takehiko Suzue Figure 3 Figure 4 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 12 Figure 13 Figure 14 Koma = 1 Commissioner of the Office Tuition fees Michiko Tono 1 ．． Display of ゛f1 Patent Application No. 61-080452 2 Name of the invention Developing device 3 Relationship with the person making the amendment Drawstring Patent applicant (307) Toshiba Corporation (1 idiot) 4 Agent Tokyo Minato 17 Mori Building 69, 1-26-5 Toranomon.
Target of correction Drawing surface 7111i Positive contents

Claims (2)

[Claims] (1) The original image placed on the original platen of the main body of the image forming apparatus is imaged on a uniformly charged image carrier through an optical system, and the electrostatic latent image is formed. In a developing device in which developer is supplied and developed by a transmission drive means using a rotating sleeve of a developing roller which is removably engaged with a drive input system gear of a forming device main body and interlocked with each other,
The rotary sleeve and the drive transmission gear of its rotary shaft are provided with play greater than the engagement rotation angle during attachment/detachment to the drive input system gear of the image forming apparatus main body, and A developing device characterized by being able to prevent rotation in directions other than directions. (2) An elastic member is interposed between the rotating sleeve and the drive transmission gear of the rotating shaft to always regulate the play between them in the normal direction, and the regulating force by this elastic member is
The developing device according to claim 1, characterized in that the rotational torque of the rotating sleeve is smaller than that of the rotating sleeve.