JPS6129855A - Development method using nonmagnetic one-component type developer - Google Patents

Abstract

PURPOSE:To obtain a good visible image by controlling a ratio of compression stress/developer supply amt. to a prescribed value, where the developer supply amt. and compression stress between a developer supply member and a developer carrying body are expressed by weight or load per unit area. CONSTITUTION:The developer 3 is supplied from the developer supply member 2 to the developer carrying body 1 to form the layer of a prescribed supply amt. of developer and development is carried out by giving a prescribed compression stress between the member 22 and the body 1. A good image can be obtained, preferably, by selecting the following region as shown in the graph expressing the correlation between this compression stress and the supply amt.: The value of compression stress/developer supply amt. R is controlled to >=3X10<5>, where the developer supply amt. is expressed by weight (g) per unit area cm<2> of the surface of the body 1, and the compression stress between both 1, 2 is expressed by load (g) per unit area cm<2>, and as a result, even when a solid black part wide in area is developed, image density is never lowered.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to the field of electrophotographic copying machines, and more specifically:
This invention relates to an improvement in a developing method using a non-magnetic one-component developer.

Conventional technology and its problems In order to develop a latent image using a non-magnetic one-component developer in an electrophotographic copying machine, generally the developer is placed between a developer supply member and a developer supplying member that are in pressure contact with each other while rotating. The developer is sequentially supplied from the developer supply member to the developer carrier while being rubbed with the carrier and given a predetermined electric charge. The developer supplied to the developer carrier is formed into a thin layer by a suitable image forming member and is conveyed to a holder that holds an electrostatic latent image to visualize the latent image. .

In the conventional developing method using such a method, when developing a latent image having a solid black area over a wide area, the density of the image on the carrier (specifically, the density of the image on the developer carrier in the area above the director) is There was a problem in that the density of the corresponding image became lighter.

SUMMARY OF THE INVENTION An object of the present invention is to provide a developing method that solves these problems and allows other images to be visualized well even when a wide-area solid black area is developed.

Means for Solving the Problems and Their Effects The present inventor has conducted extensive research in view of the fact that conventional methods have been implemented without giving special consideration to the factors that control the density of images. The amount of developer transported by the developer carrier and the pressure contact force between the developer supply member and the developer carrier (
It has been found that the above-mentioned problems can be solved by performing development so that the compressive stress) satisfies a specific relationship.

Thus, according to the present invention, the non-magnetic one-component developer is rubbed between the developer supply member and the developer carrier, which are in pressure contact with each other while rotating, and an electric charge is imparted to the developer. A developer is supplied from the supply member to the carrier to form a layer of developer of a predetermined conveyed amount on the carrier, and the layer is sent to a holder that holds the electrostatic latent image so that the latent image can be transferred. This is a developing method using a non-magnetic one-component developer that develops a visual image, and the amount of developer conveyed is determined by the unit area of the surface of the developer carrier (weight (g) per cnO), the developer supply member and the developer. A developing method characterized in that the value of compressive stress/developer conveyance amount is shifted so that the value of compressive stress/developer conveyance amount is 3×10 5 or more when the carrier and compressive stress are expressed as load (g) per unit area (cnt). provided.

According to the method of the present invention, as the amount of developer transported increases, the pressure contact between the developer supply member and the developer carrier is strong, so that sufficient amount of developer is supplied. It is thought that a charge is applied and thus an image with sufficient density is formed even when a solid black area is developed.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to further clarify the features of the present invention, the present invention will be described below with reference to embodiments shown in the drawings.

Embodiment FIG. 1 shows a typical example of a non-magnetic component developing apparatus to which the present invention is applied. As shown in the figure, the developer carrying member 1 and the developer supplying member 2 are in pressure contact with each other while rotating.
Developer material 3 is supplied from a suitable hopper (not shown).

The developer 3 is rubbed and charged at the pressure contact portion between the carrier 1 and the supply member 2, and a part of the developer 3 rotates while being held on the surface of the supply member as the supply member rotates. , and returns to the original pressure-welding position while being formed in layers by a suitable member 8. In this way, the charged developer is sequentially sent from the supply member 2 to the carrier 1. The developer supplied to the carrier is formed into a thin layer by the image forming member 4 and is conveyed to the holder 6 which holds the electrostatic latent image 5, thereby converting the latent image 5 into a visible image. Holder 6 and carrier 1
During this period, a bias power source is applied by a voltage source 7, so that the developing efficiency can be improved.

Development was carried out under the following conditions using a developing device having the arrangement as described above. The carrier 1 is a cylindrical member made of SUS with a diameter of 13 mm and a thickness of in+m.

A material coated with phenolic resin with a specific resistance of 166 Ω/Cm was used, and the supply member 2 was made of SUS with a diameter of 5 mm.
A cylindrical member made of E with a wall thickness of 2 mm and a specific resistance of 103 Ω・cm.
A developer coated with a PDM rubber layer was used, and a developer 3 having a particle size of about 10 μm obtained by dispersing carbon black in a styrene acrylic resin was used. The holder 6 was a cylindrical member with a diameter of 6 mm with a Se-based photoreceptor deposited on the surface, and an electrostatic latent image 5 with a surface potential of 950 V was formed thereon. The layer forming member 4 is made of SUS.
．． Made of 1mm leaf spring material, 50g/c+++
It was brought into pressure contact with the carrier 1 in the range of ~500 g/Cm. The layer forming member 8 is made of SUS 0. It was made of a plate spring material with a thickness of 1 mm and was brought into pressure contact with the developer supply member 2. Thus,
Voltage source 7 provides DC voltage of 500cm and AC voltage of 800cm.
Vpp, 300 ms was superimposed and applied as a developing bias voltage, and the holder 6 was rotated at a circumferential speed of 85 mm/sec, whereas the developer carrier 1 arranged with a gap of 150 μm was rotated at a circumferential speed of 127.5 n++n. When developing was carried out for 7 seconds while changing the amount of developer conveyed and the compressive stress between the developer carrier 1 and the developer supply member 2, the results shown in FIG. 2 were obtained. . In the graph of Figure 2, the X mark indicates that when a wide area solid black area is developed, the image density after development on the holder corresponding to the area longer than the circumference of the developer carrier becomes thinner. In addition, the O mark indicates the case where the image density does not change.

As can be understood from Figure 2, in order to obtain a good image, there is a clear correlation between compressive stress and the amount of developer conveyed, and the amount of developer conveyed is determined by the unit of developer carrier surface. area(
C) It is expressed in weight (g) per unit area (C), and the compressive stress between the developer supply member and the developer carrier is expressed as unit area (C).
If the value of compressive stress/developer conveyance amount is set to be 3×105 or more when expressed as per load (g>), even when developing a wide area of solid black area, the circumferential length of carrier 1 can be reduced. '' When the latent image in the area corresponding to the second area is developed, the image density does not become thinner.However, the peripheral speed of the carrier 1 is changed to 50 to 600 mm/sec and the development is carried out. Even if they did, such changes in the results would not be tolerated.

Effects of the Invention As mentioned above, in the developing method of the present invention, when developing using a non-magnetic component developer, no change in image density is observed even when a wide area of solid black area is developed. A good visible image can be given.

[Brief explanation of drawings]

FIG. 1 is a side sectional view showing a typical example of a non-magnetic component developing device to which the present invention is applied, and FIG. 2 is a side sectional view showing a typical example of a non-magnetic component developing device to which the present invention is applied. 7 is a graph showing that the quality of image density varies depending on the amount of developer conveyed and compressive stress. 1...Developer carrier 2...Developer supply member 3...Developer 4...Layer forming member 5...
・Electrostatic latent image 6 ・Latent image holder (, LLIO/15
) 藝(pus M

Claims (1)

[Claims] The non-magnetic one-component developer is rubbed between the developer supply member and the developer carrier, which are in pressure contact with each other while rotating, to impart an electric charge to the developer, and to develop the developer from the supply member to the carrier. A non-magnetic film that supplies a developer to form a layer of a predetermined amount of developer on the carrier, and sends this to a carrier that holds an electrostatic latent image and develops the latent image into a visible image. In a developing method using component developers, the amount of developer conveyed is defined as the weight (g) per unit area (cm^2) of the surface of the developer carrier, and the compression between the developer supply member and the developer carrier. The method described above, characterized in that the value of compressive stress/developer conveyance amount is 3×10^5 or more when stress is expressed as load (g) per unit area (cm^2).