JPH05289521A - Structure for attaching blade - Google Patents

Abstract

PURPOSE:To provide structure for attaching a blade by which a blade for regulating the napping of toner is easily and accurately attached as to the structure for attaching the blade for regulating the napping of toner which is used in a developing device. CONSTITUTION:A pair of supporting members 104 for supporting the blade for regulating the napping of toner 103 which is opposed to a developing roller 102 in the frame 101 of the developing device so that it can advance and retreat in an opposed direction is provided and attached to both sides of the frame 101. A detaining part 106a for detaining the blade 103 so that a gap between the blade 103 and the developing roller 102 may be a specified value is provided in each supporting member 104, and the blade 103 is pressed by an energizing means 105 arranged in the frame 101 and detained in the detaining part 106a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mounting structure for a toner spike control blade used in a developing device.

In a developing device used in a recording device such as an electrophotographic printer or a copying machine, it is necessary to make toner stand on a developing roller in order to develop an electrostatic latent image formed on an opposing photosensitive drum. There is. In order to control the spikes, it is necessary to keep the gap between the developing roller and the blade with high accuracy.

[0003]

2. Description of the Related Art Conventionally, an operator uses a thickness gauge or the like to make adjustments in order to improve the accuracy of the gearup.

[0004]

However, in such a conventional adjustment, there is a possibility that an adjustment error may occur or the assembly accuracy may not be sufficiently obtained because it is liable to be subject to the subjectivity of the operator due to human work. The bristles on the developing roller were not adjusted properly, which caused uneven printing.

It is an object of the present invention to provide a blade mounting structure which allows a blade to be mounted easily and accurately.

[0006]

FIG. 1 is a diagram for explaining the principle of the present invention. In the figure, 101 is a frame of a developing device, 102 is a developing roller supported by the frame 101, 103 is a blade for controlling toner spikes, 104, 104 are support members, 10
Reference numeral 5 is a biasing means. The support member 104 is the frame 10
A blade 103 facing the developing roller 102 in the unit 1 is movably supported in the facing direction, and is attached to both side surfaces of the frame 101. In this figure, the blade 10
3 is supported by the notch 106 of the supporting member 104, and the shaft 102a of the developing roller 102 penetrates the supporting member 104.

The blade 103 penetrates the square hole 101a of the frame 101 so as to be vertically movable, is fitted into the notch 106 of the support member 104, and is urged by the urging means 105 inserted between the blade 103 and the bottom surface of the frame 101. It is locked to the locking portion 106a which is the upper wall of the notch 106. It should be noted that the blade 103 is locked to the locking portion 106 while the support member 10
It is fixed to the mounting portion 107 of No. 4 with the screw 108.

[0008]

The blade 103 is biased by the biasing means 105 and locked to the locking portion 106a.
3 and the gap of the developing roller 102 are kept constant. Therefore, by accurately providing the positional accuracy of the locking portion 106a with respect to the central portion of the developing roller shaft of the supporting member 104 at the stage of parts, it is possible to easily and surely set the gear-up to a desired value. By assembling the blade 103 by the biasing means 105 so that the blade 103 is locked by the locking portion 106a, the assembling accuracy can be ensured more reliably.

[0009]

Embodiments of the present invention will be described below with reference to FIGS.

FIG. 2 is an overall schematic view of an electrophotographic apparatus to which the present invention is applied, in which 201 is a photosensitive drum and 208 is a paper accommodating portion. A charger 20 is provided around the photosensitive drum 201.
2, an exposure device 203, a developing device 40, a transfer device 205, a discharge lamp 206, and a cleaner 207 are arranged. Recording paper is accumulated and stored in the paper storage unit 208, and recording on the recording paper is performed by the following procedure. The exposure device 20
Reference numeral 3 denotes a light source including a semiconductor laser, and a light beam scanning optical system including an f.theta. Lens for scanning the light beam from the semiconductor laser along the photosensitive drum 201 at a constant speed, a polygon mirror, and the like.

At the time of recording, the photosensitive drum 201 is rotated in the direction of the arrow so that the surface of the photosensitive drum 201 is charged by the charger 2.
The whole surface is negatively charged by 02 corona discharge. Next, the character code given from the host computer or the like is converted into a dot pattern, the semiconductor laser is driven according to the video signal corresponding to this dot pattern, and the surface of the photosensitive drum 201 is irradiated with a light beam. When the light corresponding to the dot pattern is irradiated, the charge of the exposed portion is reduced and an electrostatic latent image is formed. When this latent image area passes the developing device 40, the negatively charged toner adheres to it and a toner image is formed.

On the other hand, the recording paper is supplied one by one to the position where it comes into contact with the toner image on the photosensitive drum by the action of the pick roller 209 and the standby roller 210. The transfer unit 205 is arranged below the photosensitive drum 201 with the recording paper sandwiched therebetween, and is configured to give a positive charge to the recording paper. Therefore, the toner image formed on the photosensitive drum 201 is attracted to the positive charges of the recording paper and transferred to it.

The recording paper carrying the toner image is fixed on the fixing device 21.
The toner image is fixed between the heat roller 212 and the rubber roller 213 which is pressed against the roller 121 and rotates, and is fixed on the recording paper by heat and pressure. After that, the recording paper is discharged to the outside by the discharge roller 214. In addition, the surface of the photosensitive drum 201 after the transfer is the static elimination lamp
The charge is completely removed by 06 and the residual toner is cleaned by the cleaner 207 to return to the initial state, and the above cycle is repeated again. Although the negative charging process is described in the above description, the positive charging process is the same.

An outline of the developing device 40 will be described with reference to FIG.
In FIG. 3, reference numeral 1 is a developing roller, 2 is a blade for regulating toner spikes (corresponding to the blade 103 in FIG. 1), 3 is a scraping plate for scraping off the toner on the developing roller 1,
Numerals 4 and 5 are spiral screws for agitating and conveying the developer, 6 is a partition plate for partitioning the spiral screws 4 and 5 by an intermediate portion (a portion excluding both ends), and these are a frame 7 and a cover 8. Are arranged in a housing 9 composed of.

The developer supplied from the toner replenishing roller 10 is agitated and conveyed by the spiral screws 4 and 5 having the same shape and rotating in opposite directions, and the charged developer is charged on the developing roller 1. Supplied on the surface. At this time, the blade 2 regulates the rising of the toner. The electrostatic latent image formed on the photosensitive drum (not shown) that is closely opposed to the developing roller 1 is developed by the developing roller 1, and the residual toner after development is scraped off by the scraping plate 3.

Normally, a stirring roller is provided below the developing roller 1 and the spiral screw 5 to assist the supply of the developer to the developing roller, but it is omitted in FIG. did.

Next, a blade mounting structure having such a structure and action will be described with reference to FIGS.

FIG. 4 is a front sectional view showing a main part of the developing device shown in FIG. 3. In FIG. 4, 11 is a pair of supports fitted to the shaft 1a of the developing roller 1 and attached to both side surfaces of the frame 7. Members (corresponding to the supporting member 104 in FIG. 1) and 12 are leaf spring-shaped biasing means (corresponding to the biasing means 105 in FIG. 1). Blade 2
Is pierced through a square hole 7a (corresponding to the square hole 101a in FIG. 1) of the frame 7 so as to be vertically movable, and is urged upward by urging means 12 inserted between the frame 7 and the bottom surface thereof. The support member 11 is locked to the locking portion 13 (corresponding to the locking portion 106a in FIG. 1) of the notched upper wall (details will be described later). Then, in this state, the blade 2 is attached to the support member 11 (corresponding to the attachment portion 107 in FIG. 1 by a screw (described later) inserted into the fool hole 2a (not shown)). Fixed to.

The following is a supplementary description of configurations other than those described above related to the present invention. Reference numeral 14 denotes a ring-shaped seal member made of sponge or the like, which is fitted to each end of the developing roller 1 and is in contact with the inner wall of the frame 7. Further, a labyrinth portion 15 is formed in a portion of the cover 8 corresponding to the seal member 14 to prevent the developer from leaking from the outer periphery of the seal member 14. A seal member 16 made of sponge or the like is provided at the bottom of the frame 7 and is in contact with the inner wall of the frame 7. Therefore, leakage of the developer from the inside of the housing 9 to the outside is prevented.

The blade mounting structure of the present invention is constructed as described above, and since the blade 2 is biased by the biasing means 12 and locked by the locking portion 13, the blade 2 and the developing roller 1 The gearup of is kept constant. Therefore, the positional accuracy of the locking portion 13 (from the hole fitted to the shaft 1a to the locking portion 1
By accurately setting the distance (up to 3) at the component stage, the gearup between the developing roller 1 and the blade 2 can be easily and accurately set to a desired value, and the conventional adjustment work is unnecessary.

FIG. 5 is an exploded perspective view showing the details of the developing device. According to this drawing, the above-described structure and operation will be further clarified, and the parts not shown and described in the above description will be clear. A supplementary explanation of the omitted portion will be given below with reference to FIG.

Notch 17 of support member 11 (notch 10 of FIG. 1)
6 is a portion through which the end portion of the blade 2 is inserted and supported, and a mounting portion 18 (corresponding to the mounting portion 107 in FIG. 1) is a portion where the blade 2 is fixed by a screw 19. The groove 20 at the bottom of the frame 7 is provided with the biasing means 12 and the seal member 16.
It is for mounting. Reference numeral 21 is a gear group for driving each roller, and reference numeral 22 is a density sensor attached to the bottom of the frame 7.

FIG. 6 shows another embodiment.

In the case of this example, the lower surface of the blade is engaged with the engaging portion 32a at the lower edge of the notch 32 of the supporting member 31 (corresponding to the supporting member 11 of the previous example). In this case, the locking portion 32a
By accurately maintaining the positional accuracy of, that is, the dimension a in FIG. 6, it is possible to accurately maintain the gap between the developing roller and the blade. However, in this case, it is necessary to maintain the height of the blade with high accuracy. The biasing means in this case is naturally a tension spring.

In the above description, the supporting member is outside the developing device frame, but the supporting member may be inside the frame. Further, the biasing means may be a coil spring, a torsion coil spring, or the like. Further, the seal member 16 shown in FIGS.
It can also be made to serve as a biasing means (using elasticity of sponge).

[0026]

As described above, according to the present invention, the blade can be positioned easily and accurately by merely engaging both ends of the blade with the engaging portions of the supporting members on both sides of the developing roller. , The conventional adjustment work becomes unnecessary.
In addition, adding an urging means for urging the blade to engage the engaging portion is more effective in ensuring the assembly accuracy.

[Brief description of drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is an overall schematic diagram of an electrophotographic apparatus to which the present invention is applied.

FIG. 3 is a side view showing an outline of the developing device in FIG.

FIG. 4 is a front sectional view showing a main part of the developing device of FIG.

FIG. 5 is an exploded perspective view showing details of the developing device according to the embodiment of the present invention.

FIG. 6 is a perspective view showing a blade mounting structure according to another embodiment of the present invention.

[Explanation of symbols]

 1,102 Developing roller 2,103 Blade 7,101 Frame 7a, 101a Square hole 11,31,104 Support member 12,105 Energizing means 13,32a, 106a Locking part 17,32,106 Cutout 18,107 Mounting part 19,108 screws

Claims (2)

[Claims] 1. A pair of support members (104) for supporting, in a frame (101) of a developing device, a blade (103) for controlling toner spikes facing a developing roller (102) so as to be capable of advancing and retreating in the facing direction. The supporting member (104) is provided on both sides of the frame (101), and the blade (10) is attached to each supporting member (104).
A blade mounting structure characterized in that a locking portion (106a) for locking the gear 3) with the developing roller (102) to a predetermined value is provided. 2. The blade mounting structure according to claim 1, wherein the urging member is disposed in the frame (101) and urges the blade (103) to engage with the engaging portion (106a). A blade mounting structure characterized by the addition of means (105).