JPH0462585B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a developing device using a monocomponent magnetic toner, and particularly to a developing device using a monocomponent magnetic toner, in which the monocomponent magnetic toner supplied onto a carrier is controlled to a predetermined amount of developer by a regulating member. The present invention relates to a developing device that develops an electrostatic latent image using this amount of developer.

[Conventional technology]

Conventionally, in electronic copying machines and the like, a device as shown in FIG. 1 has been used as a one-component developing device for developing an electrostatic latent image on a photoreceptor using a one-component magnetic toner. . In FIG. 1, 1 is a photoconductive drum capable of holding an electrostatic latent image 2;
The developing device is disposed close to and facing the photoconductive drum 1 . The developing device has a hopper 3 for containing one-component magnetic toner 4 and a magnet roll 5 in which a plurality of magnetic poles fixed so as not to rotate are arranged alternately. It consists of a non-magnetic cylindrical sleeve 6 that is rotatably fixed to the sleeve 6 and a regulating blade 7 that is placed in pressure contact with the sleeve 6 to regulate the amount of magnetic toner on the sleeve 6.
A regulating blade 7 is disposed within the hopper 3 and a sleeve 6 is disposed close to the photoconductive drum 1. In such a developing device, the one-component magnetic toner 4 housed in the hopper 3 is controlled by a regulating blade 7 held on the surface of the sleeve 6 by the magnetic force of a magnet roll to an amount of 1 to 2 mg/cm ^{2 .} Controlled rotation of the sleeve 6 drives the photoconductive drum 1 and the sleeve 6 into opposing development areas. sleeve 6
An AC voltage from an AC high voltage power supply 9 is applied to the photoconductive drum 1 at the developing nip (the part where the photoconductive drum 1 and the sleeve 6 are close to each other and face each other).
The electrostatic latent image held by can be developed. However, such a developing device has a problem in that the amount of toner that adheres to the surface of the sleeve 6 is small or uneven, resulting in an unstable amount of toner adhesion.

[Problem that the invention seeks to solve]

An object of the present invention is to solve the problems of the conventional one-component developing device, and to make the amount of toner adhering on the sleeve 6 surface after passing through the regulating blade stable at 1 to 2 mg/cm ² at all times. Our purpose is to provide developing equipment.

[Means and actions for solving problems]

As a result of intensive research, the inventor of the present invention found that there is a relationship between the surface roughness of the sleeve 6, the contact pressure (g/cm) of the regulating blade 7, and the amount of toner adhering on the surface of the sleeve 6 in the above-mentioned one-component developing device. We discovered that we had found the optimal relationship. That is, sleeve 6
When the surface roughness is the 10-point average roughness Rz (μ) and the contact pressure of the regulating blade is X (g/cm), set so that the following formula 0.01X+1≦Rz≦0.01X+11 holds true. They discovered that even and good toner adhesion could be obtained and completed the present invention.

Figure 2 shows the sleeve surface roughness Rz, the contact pressure of the regulating blade X (g/cm), and the toner adhesion amount (2 mg/cm).
cm ² and 1 mg/cm ² ),
From this figure, the roughness of the sleeve surface and the contact pressure of the regulating blade to obtain the required amount of toner adhesion can be determined.

〔Example〕

Example 1 Hereinafter, examples of the present invention will be described, and the functions and effects of the one-component developing device according to the present invention will be specifically explained. The one-component magnetic toner used in the present invention contains 55 wt% of magnetic powder.
In addition, 22.5wt% of styrene-dimethylaminoethyl methacrylate copolymer and polypropylene wax are used as the main binder, and 22.5wt% of styrene-butadiene copolymer is used as the sub-binder.
Furthermore, furnace black type carbon is added externally. A one-component developing device as shown in Figure 1 was used, the sleeve was made of SUS with a surface roughness of Rz = 8μ, and the contact pressure of the rubber regulation blade was set at 100 g/
The amount of toner adhering to the sleeve surface is cm.
The toner layer was 1.65 mg/cm ² and uniform. The one-component developing device set up in this way is used as an electrostatic latent image carrier, and the organic photoreceptor (PVK system) is set at an initial potential of -
When I set it to 800V and developed it, a good image was obtained. The voltage applied to the developing machine at this time is AC2K
Hz, peak-to-peak voltage 1500V, DC voltage -
It was 200V.

Example 2 The roughness of the SUS sleeve surface is Rz=10μ,
When the contact pressure of the SUS regulation blade was 150 g/cm, the amount of toner adhesion was 1.8 mg/cm ² . When copies were collected using the developing machine set in this manner under the same conditions as in Example 1, good images were obtained.

Example 3 As a non-magnetic sleeve, a semiconductive resin sleeve made of phenolic resin and having a diameter of 10 ⁹ Ωcm was polished in the axial direction so that the surface roughness was R ₂ =4μ, and the configuration of the regulating blade 7 was as shown in Fig. 3. It was constructed from a spring material 8 and a rubber material as shown. When the rubber material was pressed against the sleeve with a contact pressure of 150g/cm, the amount of toner adhesion was 12
mg/ ^cm2 . When a latent image was developed using the one-component developing device set in this manner under the same latent image conditions as in Example 1, a good image was obtained. The voltage applied to the developing machine at this time was AC2.4KHz, peak-to-peak voltage 2400V, and DC voltage -200V.

〔Effect of the invention〕

In the one-component developing device of the present invention, when the surface roughness of the sleeve is the 10-point average roughness Rz (μ) and the contact pressure of the regulating blade is X (g/cm), 0.01X+1 (μ)≦Rz≦0.01X+11 (μ), and when developing an electrostatic latent image formed on a photoreceptor drum or dielectric material, it is possible to obtain an even and sufficient amount of toner adhesion, which is stable. Since copies with good image quality can be obtained, reliability is improved and service costs are reduced.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing the configuration of a one-component developing device;
Figure 2 shows the roughness of the sleeve surface Rz, the contact pressure of ^the regulating blade
cm ² ), and FIG. 3 is a configuration diagram of one embodiment of the regulating blade used in the device of the present invention. Codes in the figure: 1... Electrostatic latent image carrier; 2... Electrostatic latent image; 3... Hopper; 4... One-component magnetic toner; 5... Magnet roll; 6... Sleeve;
7... Regulation blade; 8... Spring material; 9... Rubber material.

Claims (1)

[Scope of Claims] 1. A hopper for accommodating one-component magnetic toner, a fixed magnet roll including a plurality of magnetic poles, and a non-magnetic cylindrical sleeve rotatably fixed around the roll; In a one-component developing device consisting of a regulation blade for regulating the amount of magnetic toner on the sleeve, the surface roughness of the sleeve is Rz (μ), which is the 10-point average roughness, and the contact pressure of the regulation blade is X ( g/cm), the following formula holds: 0.01X+1≦Rz≦0.01X+11.