JPS63118172A - Developing device - Google Patents

Abstract

PURPOSE:To easily and finely adjust a drum and a slim gap by utilizing the slanting surface of a slanting cam and an abutting surface which slides thereupon. CONSTITUTION:The abutting surface 6 which abuts on the slanting cam 5 is fixed to an L-shaped stay 2a as part of a main body frame 2, a developing device 3 is pressed by a pressure spring 7, and the slanting surface of the slanting cam 5 is alway brought into contact with the abutting surface 6 at all times. Further, an adjusting screw 8 which engages the screw hole 2b of the main body frame 2 is provided on the flank of the developing device 3, and this adjusting screw 8 is rotated to move the developing device 3 in the direction of the shaft 4a of a developing sleeve 4. The pressure spring 7a provided to the adjusting screw 8 eliminates a play at the movement position. The slanting of the slanting cam 5 slides on the abutting surface 6 by said movement to adjust the drum and the slim gap. The position of the developing device 3 is fixed with a setscrew 10 after the adjustment.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a developing device used in an electrostatic copying machine or the like.

[Prior Art] Conventionally, developing methods for visualizing electrostatic latent images on image carriers include:
A magnetic developer is placed on the developing sleeve by the magnetic force of a magnet contained in the developing sleeve and brought close to the image carrier, and the developer is attracted by the electrostatic force of the electrostatic latent image to form an image. It has been known. In this developing method, in order to obtain good development, it is necessary to appropriately adjust the distance between the image carrier and the developing sleeve (hereinafter abbreviated as drum or sleeve gap). In other words, for original images with halftones, it is better to have a narrower drum and sleeve gap.
In addition, for images such as characters that have stepwise shading, a relatively wide width can provide better development results. As one means of adjusting the drum and sleeve gaps according to the image of the original, elliptical spacer rings are attached to both ends of the shaft of the developing sleeve in Japanese Patent Application Laid-open No. 183674/1983.
A device is disclosed in which the drum and sleeve gap are adjusted by rotating this.

[Problems to be solved by the invention] However, in the above method, since the developing sleeve contains a magnet, rotating the shaft of the spacer ring shifts the position of the magnet, changing the developing conditions and causing noise in the image. There is a problem. If you try to rotate it by other means, the mechanism becomes complicated, such as attaching a gear to the spacer ring and meshing with another gear to drive it, and then also forcing the elliptical spacer ring's inclined surface to come into contact with the image carrier side. In some cases, the problem becomes even more complicated, such as requiring a means for fixed setting.

This invention was made in order to solve the above-mentioned problems, and uses a comparatively simple mechanism to easily and precisely manufacture drums, both in the manufacturing process and in actual use.
The purpose is to provide a developing device that can adjust the sleeve gap.

[Means for Solving the Problems] As shown in FIGS. 1(a) and 1(b), the developing device of the present invention has a developing device mounted on either one of the main body frame 2 supporting the image carrier l and the developing device 3. An inclined cam 5 having an inclined surface along the axis 4a of the sleeve 4 is provided with a contact surface 6 that abuts the inclined cam 5 on the other side, and the developing device 3 is arranged in the axial direction of the developing sleeve 4
In other words, by moving in the direction of the arrow, the image carrier l
The percentage mark is to adjust the distance between the developing sleeve 4 and the developing sleeve 4 in the direction of arrow B.

[Operation] By configuring the developing device as described above, fine g4m of the drum and sleeve gaps can be easily performed using the inclined surface of the inclined cam 5 and the contact surface that slides thereon.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings. FIG. 2(a) is a plan view of this embodiment, FIG. 2(b) is a partial sectional view thereof, and FIG. 2(C) is an explanatory diagram of the suppression mechanism.

In the figure, reference numeral 1 denotes a drum-shaped image carrier that carries an electrostatic image, and a developing device 3 is provided in the main body frame 2 that holds the image carrier 1 in the vicinity of the image carrier 1. The developing device 3 is equipped with a developing sleeve 4 for conveying developer (not shown) to the image carrier 1, and on the left and right sides of the developing device 3 are a drum and two inclined cams 5 for adjusting the sleeve gap. is provided. On the other hand, a contact surface 6 that contacts the inclined cam 5 is fixed to an L-shaped stay 2a that is a part of the main frame 2, and the developing device 3 is pressed by a suppression spring 7, and the inclined surface of the inclined cam 5 is It is designed to be in constant contact with the contact surface 6. Further, an adjustment screw 8 is provided on the side surface of the developing device 3, and is screwed into the screw hole 2b of the main body frame 2.
By rotating this adjustment screw 8, the developing device 3 is moved in the direction of the axis 4a of the developing sleeve 4. The pressure hole 7a provided on the adjustment screw 8 is for preventing play in the moving position.

By this movement, the inclined surface of the inclined cam 5 slides on the contact surface 6, and the drum and sleeve gaps are adjusted. When moving the developing device 3, as shown in FIG.
The support rod 9 that supports the developer unit 3 moves in a long hole 2d provided in the rectangular stay 2C, so that it does not interfere with the movement of the developing device 3. After 14 m, the position of the developing device 3 is fixed with a set screw lO.

By configuring the developing device in this way, ζ
Easily tighten the drum and sleeve gap on the side where the adjustment screw 8 is installed, that is, on the operator's side! ! can. Although the drum and sleeve gaps are adjusted at a very old age level, they can be adjusted more accurately by appropriately selecting the angle of the tilt cam 5 and the thread pitch of the adjusting screw 8. In addition, by providing inclined cams 5 on the left and right sides, the developing device 3
The position of is stabilized.

FIG. 3 shows a second embodiment of the invention. In this embodiment, as shown in the figure, an inclined cam 5 and a contact surface 6 are provided near both ends of the shaft of the developing sleeve 4 to receive the thrust when the developing device 3 moves. By providing this in place, it is possible to minimize the effects on the drum and sleeve gap due to vibrations of the device body.

FIG. 4 shows a third embodiment of the invention. This embodiment is a modification of the second embodiment in which the inclined cam 5 or the contact surface 6 can be moved independently, so that the parallelism between the shafts 4a of the image carrier 1 and the developing sleeve 4 can be corrected. It is. FIG. 4 shows an arrangement in which the position of the inclined cam 5' is adjusted with a balance adjustment screw 11 to correct parallelism. Note that the suppression spring 7b is for preventing the tilt cam g from rattling. In this embodiment, the parallelism between the image carrier 1 and the developing sleeve 4 can be easily corrected both during manufacture and during use.

FIG. 5 shows a fourth embodiment of the invention. In this embodiment, the inclined cam 5 is a tapered race ring provided at both ends of the developing sleeve 4, and the contact surface 6 is a 7-lung portion provided at both ends of a drum-shaped image carrier l. The whole can be made smaller. In this first embodiment, the race ring can be used as the contact surface 6, and the 7 flange portion can be tapered to form the inclined cam 5.

FIG. 6 shows a fifth embodiment. Similar to the third embodiment shown in FIG. It is possible to perform degree correction.

In the second to fifth embodiments, the means for moving the developing device 3 in the direction of the axis 4a of the developing sleeve 4 and the means for suppressing the abutting surface 6 of the inclined cam 5 are the same as in the first embodiment. be.

However, the present invention is not limited to the above-mentioned embodiments, and can be implemented in various modifications without changing the gist.

For example, the present invention can be practiced even if the positions of the inclined cam 5 and the contact surface 6 are reversed.

[Effects of the Invention] In the developing device of the present invention, by optimizing the inclination angle of the inclination cam, fine adjustment of the drum and sleeve gap can be made by a relatively large movement in the axial direction of the sleeve, such as by rotating an adjustment screw. It can be done easily.

Generally, in this type of apparatus such as a copying machine, the various parts are often adjusted by the operator, but the present invention allows the operator to easily adjust the drum and sleeve gaps.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the principle of this invention, Fig. 2 is a block diagram of a first embodiment of this invention, and Figs. 3 to 5 are block diagrams of second to fourth embodiments of this invention, respectively. be. 1... Image carrier 2... Main body frame 2a.
・L-shaped stay 2b, 2d...Long size 2c・
...Square stay 3...Developer 4...Developing sleeve 4a...Shaft 5.5'...Incline cam
6... Contact surface 7.7a... Pressing spring 8.
...%W screw 9"...Support rod 10...Set screw 11...Balance adjustment screw Fig. 1 Fig. 3 Fig. 4 Fig. 5

Claims (6)

[Claims] (1) In a developing device equipped with an image bearing member and a developing device, an inclined surface along the axis of a developing sleeve provided in the developing device on either the main body frame side that supports the image bearing member or the developing device side. A distance between the image carrier and the developing device is adjusted by providing an inclined cam with a slanted cam and a contact surface that abuts the inclined cam on the other side, and moving the developing device in the axial direction of the developing sleeve. A developing device characterized by: (2) The developing device according to claim 1, wherein the inclined cam and the contact surface are provided on the left and right sides of the developing device, respectively. (3) The means for moving the developing device is provided by rotating an adjustment screw provided on a side surface of the developing device and supported by the main body frame. Developing device. (4) The developing device according to any one of claims 1 to 3, wherein the inclined cam and the contact surface are provided near both ends of the developing sleeve. (5) The inclined cam or the contact surface is movable in order to correct the parallelism between the image carrier and the developing sleeve. The developing device described. (6) Claims 1 to 5, wherein the inclined cam or contact surface is a race ring provided at both ends of the developing sleeve or a flange portion provided at both ends of the image carrier. The developing device according to any one of the above.