JPH02220081A - Developing device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a developing device that performs development using non-magnetic toner.

[Prior art] A conventional developing method or developing device is disclosed in Japanese Patent Application No. 1983-1991.
000, the applicant has at least one electric field generating means adjacent to the toner conveying body, and the electric field generating means induces an electric charge to the toner to electrostatically adhere the toner to the toner conveying body. The electrostatic latent image is visualized by causing the toner to adhere to the latent image carrier at a portion where the latent image carrier and the toner carrier are adjacent to each other.

[Problems to be Solved by the Invention] However, in the above-mentioned prior art, the pressure and frictional force applied to the contact portion between the toner and the toner transport amount regulating member in the gap between the toner transport body and the toner transport amount regulating member are insufficient. As a result, the residence time of the toner in the gap becomes insufficient, and as a result, the amount of charge on the toner on the toner conveying member becomes insufficient and the distribution of the amount of charge on the toner becomes broad, resulting in optical temperature unevenness. However, there has been a problem in that it is not possible to stably form high-quality images without turbulence.

In addition, in the gap between the toner conveyance body and the toner conveyance amount regulating member, the pressure and frictional force applied to the contact area between the toner and the toner conveyance amount regulating member are insufficient, so a large amount of toner is supplied to the gap. When this occurs, some toner passes through the gap without adhering to the toner conveying body (or toner conveyance amount regulating member) and stays at the bottom of the developing device, resulting in a decrease in the amount of toner supplied to the gap. However, there is a problem in that a mechanism is required to limit the amount of toner accumulated in the developing device or to collect the toner accumulated at the bottom of the developing device.

SUMMARY OF THE INVENTION The present invention aims to solve these problems, and its purpose is to provide a developing device using a one-component nonmagnetic developing method that can stably form high-quality images with a simple structure. It is in.

[Means for Solving the Problems] The developing device of the present invention includes a toner conveying body that is disposed adjacent to a latent image carrier that forms an electrostatic latent image and that conveys toner that is an image forming body. , a developing device that makes an electrostatic latent image visible by electrostatically adhering the toner on a toner carrier to a latent image carrier, the toner carrier forming an insulating layer on a conductive support. A developing device in which a plurality of conductive toner conveyance amount regulating members are arranged adjacent to a toner conveying body, and an electric field is applied between the conductive support body and the toner conveyance amount regulating members by a voltage applying means. The surface roughness of at least one toner transport amount regulating member among the toner transport amount regulating members is 30% or more of the volume average particle diameter of the toner as expressed by JIS standard 10 point average roughness (08-B0601). It is characterized by

[Function] According to the above configuration of the present invention, sufficient pressure and frictional force can be applied to the contact portion between the toner and the toner transport body in the gap between the toner transport member and the toner transport amount regulating member. The residence time of the toner in the gap becomes sufficient, and as a result, the amount of charge of the toner on the toner transport body becomes sufficient and the distribution of the charge amount of the toner becomes sharp, and a large amount of toner is supplied to the gap. Even when the image forming apparatus is used, the amount of toner that passes through the gap without adhering to the toner transport body (or toner transport amount regulating member) is reduced, so that high-quality images can be stably formed with a simple structure. becomes possible.

Hereinafter, the present invention will be explained in detail with reference to Examples.

[Example] FIG. 1 shows a cross-sectional overview of a developing device in an example of the present invention.

The latent image carrier 1 has a photoconductive layer 3 coated on a conductive support 2, and the photosensitive layer 3 is charged to a predetermined potential using a charger 4. Afterwards, the light emitted from a light source 5 such as a laser is scanned using a rotating polygon mirror or the like (not shown), and an image is formed on the photosensitive layer 3 by an imaging optical system 6 to obtain a potential contrast, and the image is transferred onto the latent image carrier 1. forms an electrostatic latent image. Note that the latent image carrier 1 rotates in the direction indicated by A in the figure.

The developing device 7 charges the toner 8, which is an image forming member, and transports the toner 8 with a toner transporting member 9. The toner conveying body 9 has a thin insulating layer 11 formed on a conductive support 10, and rotates in the direction indicated by B in the figure. Adjacent to the toner conveying body 9, a conductive cylindrical sleeve 13, which is a toner conveyance amount regulating member and rotates in the direction shown by C in the figure, is disposed. Further, numeral 14 in the figure similarly represents a toner transport amount regulating member, which is a conductive flat blade. In addition, the conductive support l
Power sources 15 and 16 are connected between the conductive support 10 and the blade 14 and between the conductive support 10 and the blade 14 as means for applying voltage. Cavity and conductive support 10 and blade 1
By generating an electric field in the gap between the sleeve 13 and the blade 14, charges are injected into the toner 8 from the sleeve 13 and the blade 14, and the toner 8 is charged to a predetermined amount of charge. Note that the toner 8 adhering to the sleeve 13 is peeled off from the sleeve 13 by a scraper 17.

The toner 8 that has passed through the gap between the conductive support 10 and the sleeve 13 and the gap between the conductive support 10 and the blade 14 is given an electric charge and is applied to the toner conveying body 9 by electrostatic mirror image force. held and transported by

A power source 18 is connected between the support 2 and the conductive support 10 as means for applying a developing bias, and applies a developing electric field according to the potential contrast of the electrostatic latent image on the latent image carrier 1. Development gap (?II image carrier 1 and toner conveyor 9
occurs in the area (near the area). The toner 8 conveyed to the development gap flies toward the electrostatic latent image on the latent image carrier 1 due to the development electric field, and further adheres to the latent image carrier 1, thereby making the latent image visible.

Further, the toner 8 deposited on the latent image carrier 1 is electrostatically transferred onto the recording paper 20 by the transfer device 19, and the toner 8 is further fixed on the recording paper 20 by means such as pressure or heating to form a desired image. An image is obtained.

In this embodiment, the potential of each part is Ov for the support 2 of the latent image carrier 1, -300V for the conductive support 10, and -300V for the conductive support 10,
J-blade 13 to -900V, blade 14 to -900V
It was set to V.

In this embodiment, the gaps between each part are 0.2 mm between the latent image carrier 1 and the toner conveying body 9, 0.15 mm between the toner conveying body 9 and the sleeve 13, and 0.15 mm between the toner conveying body 9 and the blade 14. The interval between them was set to o and tsmm.

Further, in this example, a semiconductor laser was used as the light source 5.

Note that the above-mentioned numerical values and the configuration of the latent image carrier 1 or the toner conveying body 9 are not intended to limit the present invention.

Example 1 In this example, a non-magnetic one-component toner having a volume average particle diameter of 10 μm and containing carbon black and a styrene-acrylic copolymer as the main components was used as toner 8.

In the image forming apparatus using the developing device configured as described above, the sleeve 13 has a JIS standard 10-point average roughness (,0S-B06
When images equivalent to 500 sheets of A4 size plain paper were continuously formed with a surface roughness of 2 to 8 μm according to 01),
JIS standard 10 point average roughness of sleeve 13 (JIS-B
0601), the maximum optical density of the obtained image equivalent to 500 sheets of A4 size plain paper, and the difference between the maximum optical density and the minimum optical temperature (hereinafter referred to as optical temperature unevenness), there is a correlation shown in Figure 2. was recognized.

As is clear from FIG. 2, the criterion for determining the quality of an image is the maximum optical density of 1. 4 or more and the optical temperature unevenness is 0°2 or less, the JIS standard 10-point average roughness of the sleeve 13 (JI
When the surface roughness according to S-B0601) is 3 μm or more, that is, the average particle diameter of toner 8 is 10 μm, the surface roughness according to the JI 310 point average roughness of sleeve 13 is 30% of the volume average particle diameter of toner 8. A good image can be obtained under the above conditions.

In addition, the JIS standard 10-point average roughness of the sleeve 13 (JIS
-B0601) was made smaller than 3 .mu.n, that is, less than 30% of the volume average particle diameter of toner 8, toner 8 was found to stay at the bottom of the developing device.

Example 2 In this example, a nonmagnetic one-component toner having a volume average particle diameter of 12 μm and containing carbon black, wax, and polyester resin as the main components was used as toner 8.

In the image forming apparatus using the developing device configured as described above, the sleeve 13 has a JIS standard 10 point average roughness (JIS-BO8
When images equivalent to 500 sheets of A4 size plain paper were continuously formed with a surface roughness of 2 to 8 μm according to 01),
JIS standard 10 point average roughness of sleeve 13 (JIS-B
0601) and the maximum optical density and optical temperature unevenness in the obtained images equivalent to 500 sheets of A4 size plain paper, the correlation shown in FIG. 3 was observed. As is clear from FIG. 3, the criteria for determining the quality of an image are maximum optical density 1.
4 or more and optical temperature unevenness 0. If it is 2 or less, the JIS standard 10 point average roughness of the sleeve 13 (JIS-B060
When the surface roughness according to 1) is 3°6 μm or more, that is, since the average particle diameter of the toner 8 is 12 μm, the sleeve 1
A good image can be obtained when the surface roughness according to the JISIO point average roughness of No. 3 is 30% or more of the volume average particle diameter of the toner 8.

In addition, the JIS standard 10-point average roughness of the sleeve 13 (,0S
-B0601) was less than 3.6 μm, that is, less than 30% of the volume average particle diameter of toner 8, retention of toner 8 was observed at the bottom of the developing device.

Although the embodiments have been described above, the present invention can be applied not only to the embodiments described above, but also to a wide range of image forming devices such as electrophotographic recording devices, such as page printers, facsimile machines, and copying machines. Developer (toner) not required
Since it is easy to make full color images using the 3D image forming apparatus, it is particularly effective when applied to a developing device of a color image forming apparatus such as a video printer that records video images.

[Effects of the Invention] As described above, according to the present invention, an electric field is applied to the toner by an electric field generating means between the toner transport amount regulating member and the conductive support having an insulating layer on the surface to charge the toner. In a developing device that conveys and develops images by moving the toner, sufficient pressure and frictional force can be applied to the contact area between the toner and the toner conveying body in the gap between the toner conveying body and the toner conveying amount regulating member. When the residence time of the toner is sufficient, as a result, the amount of charge of the toner on the toner conveying member is sufficient and the distribution of the amount of charge of the toner is sharp, and a large amount of toner is supplied to the above-mentioned gap. Since the amount of toner that passes through the gap without adhering to the toner transport body (or toner transport amount regulating member) is reduced, high-quality images with uniform optical temperature can be stably formed with a simple structure. This has the effect of enabling an image forming apparatus using a one-component non-magnetic toner that can be formed with ease, is low cost, and easy to maintain.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional schematic diagram of a developing device in an embodiment of the present invention. FIG. 2 is a diagram showing the relationship between the JI810 point average roughness of the surface of the sleeve and the maximum optical density and optical density unevenness of the image in Example 1 of the present invention. FIG. 3 is a diagram showing the relationship between the JISIO point average roughness of the surface of the sleeve and the maximum optical density and optical density unevenness of the image in Example 2 of the present invention. 1: Latent image carrier 8: Toner 9: Toner transport body 1O: Conductive support 11: Insulating layer 13: Sleeve 14: Blade 15, 16, 18: Power source Fig. 1

Claims (1)

[Claims] A toner conveying body is disposed adjacent to a latent image carrier that forms an electrostatic latent image and conveys toner as an image forming body, and the toner on the toner conveying body is electrostatically transferred to the latent image. A developing device that visualizes the electrostatic latent image by adhering it to a carrier, wherein the toner carrier is formed by forming an insulating layer on a conductive support, and a conductive layer is formed adjacent to the toner carrier. In a developing device in which a plurality of toner transport amount regulating members are disposed, and an electric field is applied between the conductive support and the toner transport amount regulating member by a voltage applying means, the toner transport amount regulating member is The surface roughness of at least one of the toner transport amount regulating members is determined according to the JIS standard 10-point average roughness (JIS-B06
01) A developing device characterized in that the particle diameter is 30% or more of the volume average particle diameter of the toner.