JPH02196256A - Developing device - Google Patents

Abstract

PURPOSE:To reduce unnecessary waste toner and to reduce toner scattering by providing a toner collecting member at the bottom part of a space made by a toner feeder and a toner feeding quantity control member. CONSTITUTION:A developing device 7 electrostatically charges toner 8 which is an image forming body and the charged toner is fed by the toner feeder 9. The feeder 9 is made by forming a thin insulating layer 11 on a conductive supporting body 10, the toner feeding quantity control member 12, which is conductive and having cylinder shaped, is provided adjacent to the feeder 9, and in the same manner, a conductive flat plate shaped blade 13 which uniformizes the toner feeding quantity and prevents scattering is provided. Each voltage impressing means 14 is connected between the supporting body 10 and the control member 12, high electric field is generated in the space, electric charge is injected to the toner 8 from the control member 12 under the condition that the insulating resistance of the toner 8 is reduced and the toner 8 is electrostatically charged to the prescribed quantity. The weak electrostatically charged toner dropped from the space between the feeding body 9 and the control member 12 by gravity is collected by a toner collecting member 19 provided in the space between the feeding body 9 and the member 12, circulated to the control member 12 and re-electrostatically charged.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a developing device that visualizes an electrostatic latent image using toner.

[Prior Art] As disclosed in Japanese Patent Application No. 63-91000, a conventional developing device includes a thin insulating layer formed on the surface of a toner conveying body and a toner conveying amount regulating member adjacent to the toner conveying body. The idea was to provide a one-component non-magnetic developing method by controlling the toner charging and transport amount.

[Problem M to be Solved by the Invention] However, in the prior art described above, the binding force of non-magnetic toner is due to electrostatic force, so uncharged toner is removed from the gap between the toner transport body and the toner transport amount regulating member. However, there was a problem in that the toner would fall and unnecessarily discarded toner would come out and be scattered inside the developing device.

Therefore, the present invention aims to solve such problems.
The purpose is to reduce unnecessary waste toner. Furthermore, the purpose of Haku is to reduce the scattering of )・ner. Still another object is to improve the reliability of a developing device using -component non-magnetic toner.

[Means for Solving the Problems] In the developing device of the present invention, a toner conveying body is disposed adjacent to a latent image carrier that forms an electrostatic latent image, and the toner conveying body is insulated on a conductive support. In a developing device that forms an electrostatic latent image by electrostatically adhering the toner on a toner transport member to a latent image carrier, a conductive layer is formed adjacent to the toner transport member. A cylindrical toner transport amount regulating member is disposed, and a toner collecting member is disposed below a gap formed by the toner transport body and the toner transport amount regulating member.

Further, the developing device of the present invention is characterized in that the toner collected by the toner collecting member is returned to the toner transport amount regulating member.

[Function] According to the above configuration of the present invention, the toner collecting member reduces toner scattering, and if uncharged toner is collected, it flows back to the toner transport amount regulating member and is again injected with charge or caused by friction. By performing charging, toner having a stable amount of charge can be supplied to the toner conveying body.

The present invention will now be described in detail with reference to Examples.

[Example] FIG. 1 is a cross-sectional schematic view of a developing device in an example of the present invention, in which a latent image carrier 1 has a photoconductive layer 3 coated on a conductive support 2. The photosensitive layer 3 is charged to a predetermined potential using a charger 4, and then the light emitted from a light source 5 such as a laser is scanned using a rotating polygon mirror (not shown). An image is formed on the photosensitive layer 3 by the imaging optical system 6' to obtain a potential contrast and a latent image carrier]
An electrostatic latent image is formed on the conductive support 10, and the developing device 7 conveys the toner 8, which is an image forming body, with a charged toner conveying body 9. A thin insulating layer 11 is formed on top of the conductive and cylindrical 1-toner conveyance amount regulating member 12 adjacent to the toner conveying body 9.
Similarly, an electrically conductive and flat blade 13 is provided which regulates the amount of toner conveyed, makes it uniform, and prevents scattering, and the voltage applying means 14 is connected to the conductive support 1o and the toner conveyance amount regulating member, respectively. 2 and generates a high electric field in the gap to lower the insulation resistance of the toner 8, charge is injected into the toner 8 through the toner transport amount regulating member 12, and the toner 8 is charged to a predetermined amount of charge. Alternatively, the toner 8 is charged to a predetermined amount of charge by frictional charging between the toner 8 and the toner transport amount regulating member 12, and the toner 8 adhering to the toner transport amount regulating member 12 is peeled off by the scraper 15 to form a gap. The circumferential speed of the toner transport amount regulating member 12 is made larger than the circumferential speed of the toner transport body 9 and rotates in the opposite direction. to generate a fluid shear force and stirring force in the gap between the toner transport amount regulating member 12 and the toner transport body 9 to supply a thin layer of charged toner 8 to the toner transport body 9; Uncharged toner or weakly charged toner that falls due to gravity from the gap between the toner transport body 9 and the toner transport amount regulating member 12 is collected by the toner collecting member 19, and the uncharged toner adheres to the toner transport body and is transported. The toner 8 collected by the toner collecting member], 9 is returned to the toner transport amount regulating member 12 by gravity, mechanical force, etc. and is recharged, and the toner transport amount regulating member 12 and the blade 13 The toner 8 that has passed through is charged, is held by the toner conveying body 9 by electrostatic image force, and is conveyed, approaches the development gap (the part where the latent image bearing body 1 and the toner conveying body 9 are close), and is transferred to the supporting part 2. A voltage is applied by the developing bias applying means 16 between the electrostatic latent image and the conductive support 10 to generate a developing electric field according to the potential contrast of the electrostatic latent image on the latent image carrier 1, and the charged toner 8 is generated. latent image carrier 1
The latent image is made visible by flying toward the electrostatic latent image to obtain the toner adhesion amount according to the potential contrast, and then the toner 8 adhering to the latent image carrier 1 is electrostatically transferred by the transfer device 17. The toner 8 is transferred onto a recording paper 18 and fixed on the recording paper 18 by means such as pressure or heating to obtain a desired image.

In FIG. 1, the toner collecting member 19 can be a common part such as the blade 13. In this case, the toner collecting member 19 is preferably a conductive metal plate, but the toner collecting member 19 is a metal plate. In addition to the plate, a member made of resin or the like may be used. Furthermore, the toner collecting member 19 may be an elastic plate made of an elastic member and brought into contact with the toner transport amount regulating member 12. . Also, the first
In the figure, the peripheral speed of the toner conveying body 9 is 120 mm
/sec, the peripheral speed of the toner conveyance amount regulating member 12 is 600 mm/see in the opposite direction to the toner conveying body 9, the gap between the toner conveying body 9 and the toner conveying amount regulating member 12 is 0.2 mm, and the conductive By applying a voltage of -500V between the support body 10 and the toner transport amount regulating member 12,
A toner layer with a thickness of 0.1 mm can be stably formed on the toner transport body 9, and the toner transport body 9
The charge amount of the upper toner 8 is -5 μC/g, which means that a stable charge amount is obtained with small variations in the charge amount distribution, and the toner 8 with such a stable charge amount reduces the electrostatic charge of the latent image carrier J. By visualizing the latent image, a toner image with high resolution and gradation can be formed, and when a semiconductor laser is used as the light source 5, a toner image with high resolution and excellent area gradation can be formed. I was able to do that. Incidentally, in FIG. 1, arrows indicate the rotation directions of the respective members, but the above-mentioned numerical values do not limit the present invention. Regarding the toner transport body 9, a conductive support 10 and a toner transport amount regulating member 12 are also provided.
In addition to conductive non-magnetic metals such as aluminum and stainless steel, a wide variety of conductive materials such as iron and conductive resin can be used for the insulating layer 11. When formed from resins such as aromatic, silicone elastomer, polyurethane, epoxy resin, polyimide, cellulose, natural rubber, etc., it forms an insulating layer with a specific resistance cage of 0.129 cm or more that has high insulation properties, is inexpensive, and has excellent moldability. In addition, by forming the insulating layer 1 with a photoconductive material such as selenium, zinc oxide, titanium oxide, cadmium sulfide, or an organic photoreceptor, the static electricity of the insulating layer can be removed by irradiation with light, thereby creating a cylindrical structure. This enables uniform charge removal and provides a stable toner layer surface potential.
A developing device that always performs development in a constant state can be provided.

Although the embodiments have been described above, the present invention can be applied not only to the above embodiments but also to a wide range of developing devices such as electrophotographic recording devices, full-color printers, copying machines, and monochrome video printers that record television images. It is effective if applied to developing devices that use -component toner, such as copying machines, page printers, and facsimile machines.

[Effects of the Invention] As described above, according to the present invention, by disposing the toner collecting member in the lower part of the gap formed by the toner transport body and the toner transport amount regulating member, unnecessary waste is eliminated. can be reduced, toner scattering can be reduced, −
This has the effect of improving the reliability of a developing device using component non-magnetic toner. In addition, by circulating the toner collected by the toner collection member to the toner conveyance amount regulating member, a stable amount of toner can be supplied to the toner conveyance member, resulting in high resolution. This has the effect that it is possible to provide a developing device that can obtain high-4 degree images.

[Brief explanation of the drawing]

FIG. 6 is a schematic cross-sectional view of a developing device according to an embodiment of the present invention. Latent image carrier Toner Toner transport member Conductive support Insulating layer Toner transport amount regulating member Toner collecting member

Claims (2)

[Claims] (1) A toner conveying body is disposed adjacent to a latent image carrier that forms an electrostatic latent image, and the toner conveying body is formed by forming an insulating layer on a conductive support, and the toner conveying body is formed by forming an insulating layer on a conductive support. In the developing device for making the electrostatic latent image visible by electrostatically adhering the toner to the latent image carrier, a conductive and cylindrical toner transport amount regulating member is provided adjacent to the toner transport member. A developing device characterized in that a toner collecting member is disposed below a gap formed by the toner transport body and the toner transport amount regulating member. (2) The developing device according to claim 1, wherein the toner collected by the toner collecting member is returned to the toner transport amount regulating member.