JPS63155068A - Developing device - Google Patents

Abstract

PURPOSE:To easily form a uniform and stably electrified thin layer of one- component toner by using an elastic backup member to press a layer thickness control blade against a toner carrier. CONSTITUTION:A layer thickness control member 12 consists of a control blade 6 consisting of an electrifying member, a supporting plate 13, and an elastic backup member 14. The control blade 6 has the base end supporting part attached to a casing 7 and is freely turned around a fulcrum 9 and has the front end part pressed against the peripheral surface of a developing roller 4 in the direction opposite to the rotation direction of the roller 4. The supporting plate 13 is arranged approximately in parallel with the blade and has the base part fixed to the casing 7, and the elastic backup member 14 is attached to the side opposite to the blade side of the supporting plate 13 and is brought into contact with the part between the front end part and the supporting part of the blade 6. Thus, a stable pressing force is set throughout the developing roller in the breadthwise direction to easily form the uniform and stable toner thin layer on the developing roller.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a developing device used in an electrophotographic copying machine or an electrostatic copying machine. More particularly, the present invention relates to a developing device capable of forming a stable, uniformly charged thin layer of toner on a toner carrier.

Conventional technology In an electrophotographic copying machine or an electrostatic copying machine (hereinafter referred to as an electrophotographic copying machine, etc.), the surface of a photoreceptor, which is an image carrier, is first uniformly charged, and then this is charged based on a pattern corresponding to the image on the original. Exposure to light to form an electrostatic latent image. Next, a developing device supplies toner to the surface of the photoreceptor on which this electrostatic latent image exists to develop it (visualize it), and then the obtained toner acid is transferred to a transfer material such as paper.

In developing devices used in such electrophotographic copying machines and the like, it is important to supply a thin layer of uniformly charged toner to the surface of the photoreceptor. For this reason, it is necessary to keep the layer thickness of the toner carried on the surface of a toner carrier such as a developing roller and supplied to the photoconductor constant, and to make the blade pressing force that regulates the toner layer thickness uniform over the entire rlJ. There must be. In other words, if blade pruning or clogging of aggregated toner occurs, will the toner load be uniform? [A thin layer is not formed, and the resulting image has streaks and unevenness.

As a means for regulating the layer thickness of toner on the developing roller, there are various types of embankments. For example, (a) a magnetic blade is provided that is pressed against the surface of the developing roller by the attraction force of a magnet inside the developing roller to regulate the toner layer thickness (Japanese Patent Application Laid-open No. 211771), and (b) a carrier and a developing roller. Due to the attraction force with the magnet inside the roller (Japanese Patent Laid-Open No. 1986-9
5571), (c) A blade that presses against the surface of the developing roller by its own elasticity (Japanese Patent Application Laid-Open No. 54-43038)
, and (d) one in which pressure is applied to the surface of the developing roller by the elasticity of the blade and the action of a spring member (Japanese Unexamined Patent Application Publication No. 1983-1999).
No. 111737), etc. are disclosed.

FIG. 2 shows a conventional developing device in which non-magnetic toner is used as the -component developer, eliminating the need for a magnet in the developing roller (sleeve), and controlling the toner layer thickness by a layer thickness regulating blade equipped with a spring. A schematic cross-sectional view of a regulating developing device is shown. In FIG. 2, the developing device 1 includes a developing roller 4 that carries toner 2 on its surface and supplies it to the photoreceptor 3, a supply roller 5 that supplies the toner 2 onto the developing roller, and a developing roller 5 that is in pressure contact with the developing roller 4 and develops the toner. A regulating elastic blade 6 that charges the toner supplied onto the roller 4 and forms a uniform thin layer thereof, and supports the developing roller 4 and the supply roller 5;
A casing 7 is provided for housing and storing the toner 2. Further, the regulating elastic blade 6 is fixed to one end of a blade support member 8, and the blade support member 8 is attached to the casing 7 at a fulcrum 9. Furthermore, the support member 8 is
A spring 11 is provided at an end opposite to the attachment end of the regulating elastic blade 6 and extends to a spring fixed end IO of the casing 7, and presses the blade 6 against the developing roller 4.

Problems to be Solved by the Invention However, even with such a developing device, it is still not possible to keep the blade in stable and uniform pressure contact with the circumferential surface of the developing roller for a sufficiently long period of time. What is desired is a roller development device that easily forms a uniform, stable thin layer of charged toner on a roller.

Means for Solving the Problems As a result of various studies regarding this point, the inventors of the present invention have found that by pressing the layer thickness regulating blade against the toner carrier using an elastic back-up member, it is possible to easily achieve a uniform layer thickness. Furthermore, the inventors have discovered that scales can form a stable charged thin layer of a one-component toner, and have completed the present invention.

That is, the present invention provides a one-component toner developing device that includes a toner carrier having a moving surface that carries toner, and a layer thickness regulating member that charges the toner supplied onto the toner carrier and regulates the layer thickness. In the layer thickness regulating member,
The toner carrier is characterized in that it includes a regulating blade having a tip end and a support portion that come into contact with the toner carrier, and an elastic backup member that presses the regulating blade toward the surface of the toner carrier between the tip end and the support portion. The present invention provides a developing device.

Next, the present invention will be explained based on the accompanying drawings.

FIG. 1 is a schematic sectional view showing an example of a developing bag (δ) according to the present invention.

In FIG. 1, the developing device 1 of the present invention includes a developing roller 4 that is a rotating body, a supply roller 5 that is in contact with the developing roller and supplies mono-component non-magnetic toner, and the developing roller 1.
A layer thickness regulating member 12 having a regulating blade 6 pressed around the periphery of the toner 2
It consists of a casing 7.

First, the supply roller 5 is made of elastic foamed rubber, polyurethane foam, etc., and contacts the developing roller 4 with a constant pressing force (biting amount of 0.5 to 1 mm) and rotates counterclockwise in the figure. The toner 2 is supplied onto the developing roller 4. The rotation speed of the supply roller 5 is set depending on the amount of toner required.

Next, the developing roller 4, which is a toner carrier, is made of a conductive member such as aluminum whose surface has been roughened by blasting (1 to 10 μRz), and the toner is carried on the surface. Rotate counterclockwise, photoreceptor 3
Supply toner to.

Note that the toner carrier may be an endless belt whose moving surface is a desk surface.

The layer thickness regulating portion vr12 includes a regulating blade 6 made of a band 7 (i member), a support plate 13, and an elastic band member 14.

The regulating blade 6 is rotatably attached to the casing gate by a fulcrum 9 at a supporting portion at its base end, and its tip is pressed against the circumferential surface of the developing roller 4 in a direction opposite to the rotational direction of the developing roller 4 (similar blade). be done.

The regulating blade can be made of magnetic materials such as spring steel plates, non-magnetic materials such as stainless steel plates or phosphor bronze plates, and materials conventionally used for thicker regulating blades such as plastic materials and elastic rubber materials. Any of these can be suitably used. Preferably, the material is elastic. The support may also be fixed to the casing, especially if an elastic material is used.

Support board! 3 is arranged substantially parallel to the blade and fixed to the casing 7 at its base.

The elastic backup member 14 is attached to the opposing surface of the support plate 13 on the blade side, and contacts the blade between the tip of the blade 6 and the support portion.

For the elastic backup member, any appropriate material having elasticity, such as foamed silicone rubber or foamed polyurethane foam, can be suitably used. The backup member may be attached to the support plate 13 or the blade 6 by an appropriate method such as adhesion, or may be fixed to both. Further, it is preferable that the backup member is provided with a uniform thickness near the tip of the blade 6 over the entire length of the blade. This causes vibrations in the device,
Even if the blade has corrugated nails, the tip of the blade can easily come into stable contact with the developing roller. Further, unlike conventional devices, since a blade suppressing means is provided between the tip of the blade and the support portion, the layer thickness regulating member can be made smaller. Note that adjustment of the blade pressing force against the developing roller 4 can be easily achieved by appropriately changing the thickness, shape, and hardness of the backup member in addition to setting the position of the support plate. The toner used in the apparatus of the present invention is preferably a so-called -component type non-magnetic toner, but a magnetic toner or the like may also be used.

FIG. 3 is a schematic sectional view showing another specific example of the device of the present invention. In this specific example, the regulating blade 6 is set as a reverse blade.

In addition, in FIG. 3, the developing device 1 includes a developing roller 4 that is a rotating body, a supply roller 5 that contacts the developing roller and supplies toner, and on the circumferential surface of the developing roller 4,
A layer thickness regulating member 12 including a regulating plate 6 whose tip is pressed against the rotating direction of the developing roller (reverse blade).
, and a casing 7 that supports and accommodates these and also stores the toner 2. The regulating blade 6 is rotatably attached to the casing 7 by a fulcrum 9 at the base end, and is fixed to the circumference of the developing roller by an elastic backup member 14 attached to the lower surface of the top plate of the casing 7 near the tip. It is pressed against the surface as a reverse blade. Note that the toner storage portion of the casing 7 is provided with an annotator I5 that stirs the toner.

Main Claw Next, the operation of developing a photoreceptor using the apparatus of the present invention will be described with reference to FIG.

According to the apparatus of the present invention, the toner 2 stored in the casing gate is supplied onto the circumference of the developing roller 4 by the supply roller 5, which rotates counterclockwise in the figure.

The developing roller 4 is in contact with the supply roller 5 as shown in the figure.
Rotates counterclockwise to receive toner supply. Developing C7
- As the developing roller rotates, the toner on the roller 4 comes into contact with the regulating blade 6 of the layer thickness regulating member I2, thereby regulating the layer thickness, and due to the friction between the blade 6 and the developing roller 4. , is charged according to the triboelectric series between the materials. In this way, the toner that has been uniformly charged and whose layer thickness has been regulated moves further as the developing roller 4 rotates, and is formed into an electrostatic latent image on the photoreceptor 3 in the vicinity of the developing roller 4 and the photoreceptor 3. Move based.

In the developing device of the present invention, uniform and stable toner thickness is regulated, so that aggregated toner after development and recycle toner from the cleaner are regenerated when they pass through the brake 1.

Effects of the Invention As described above, according to the device of the present invention, a stable pressing force can be set over the entire width of the developing roller using the layer thickness regulating member that is easy to assemble and has a small and simple structure. This makes it possible to easily form a uniform and stable toner thin layer on the developing roller.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a specific example of the developing device of the present invention;
FIG. 2 is a sectional view showing a conventional developing device, and FIG. 3 is a sectional view showing another specific example of the developing device of the present invention. The main symbols in the figure are as follows. l; Developing device, 4: Developing roller, 6: Regulating blade, 1
2: Layer thickness regulating member, 14: Elastic backup member.

Claims (1)

[Claims] (1) In a developing device having a toner carrier having a moving surface for carrying toner, and a layer thickness regulation member for charging the toner supplied onto the toner carrier and regulating the layer thickness, The member includes a regulating blade having a tip end and a support portion that comes into contact with the toner carrier, and an elastic backup member that presses the regulating blade toward the surface of the toner carrier between the tip end and the support portion. Characteristic developing device.