JPH1152694A - Developing device for electrophotographic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent toner lumps from being fed into a developing device by providing a means for charging while loosening toner delivered from a toner makeup feeder, on a toner makeup feed path between the toner makeup feeder and a developing apparatus. SOLUTION: A makeup toner charging means 9 charging while loosening toner 1 delivered from a toner makeup feeder 7 is provided on a toner makeup feed path between the toner makeup feeder 7 and a developing apparatus 5. The makeup toner charging means 9 is composed of a rotatably supported conductive brush, for instance. Voltage of like-pole as the toner 1 is applied to this conductive brush. The toner 1 delivered from the makeup toner feeder 7 is loosened by the makup toner charging means 9 and precharged before being mixed with a developer 3 in the developing apparatus 5 so as to be able to obtain required charge quantity distribution. The toner charge quantity in a developing device can therefore be made appropriate so as to be able to obtain the developing device that can obtain stable printing quality.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a developing device for an electrophotographic apparatus.

[0002]

2. Description of the Related Art FIG. 3 shows a conventional developing device. 3, the developing device includes a developing device 5 and a toner replenishing device 7. The developing device 5 includes a two-component developer 3 including a toner 1 and a carrier 2 that frictionally charges the toner.
A developing roller 6 that supplies and conveys the developer 3 toward the photoconductor 4 on which the electrostatic latent image is formed is housed. The toner replenishing device 7 accommodates the toner 1 and rotates the toner feeding member 8 in accordance with the consumption of the toner in the developing device 5 to feed and replenish the toner 1 to the developing device 5.

[0003]

Incidentally, there is a case where the toner fed from the toner replenishing device 7 at the time of toner replenishment forms a toner lump. In the above-described conventional configuration, even if such a toner mass exists, the toner mass cannot be loosened, and the toner mass is directly sent to the developing device 5. As described above, since each toner particle cannot be sufficiently loosened to be charged, as shown in FIG. 4, the charge amount of the toner which has been present in the developer for a relatively long time (D in FIG. 4)
Has a large absolute value, and the charge amount of the toner immediately after being supplied to the developer by the toner replenishing device (relatively short time) (distribution having C in FIG. 4 as the mode). The absolute value was smaller. As a result, there is a problem in print quality (for example, background smear) caused by the presence of toner having a small absolute value of the charge amount.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a developing apparatus which can prevent toner chunks from being fed into the developing apparatus, and can optimize the amount of toner charge in the developing apparatus, thereby obtaining stable print quality. To provide.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a two-component developer comprising a toner and a carrier for frictionally charging the toner, and directing the two-component developer toward a photosensitive member having an electrostatic latent image formed thereon. An electrophotographic apparatus comprising: a developing device accommodating a developer conveying member for supplying and conveying the toner; and a toner replenishing device for accommodating the toner and feeding out and replenishing the toner to the developing device according to consumption of the toner in the developing device. Is achieved by providing a replenishing toner charging means for charging the toner fed from the toner replenishing device while loosening the toner on the toner replenishing path between the toner replenishing device and the developing device.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, the developing device includes a developing device 5 and a toner replenishing device 7.
A two-component developer 3 composed of a toner 1 and a carrier 2 that frictionally charges the toner, and a developing roller 6 that supplies and conveys the developer 3 to a photoconductor 4 on which an electrostatic latent image is formed are housed. I have. The toner replenishing device 7 accommodates the toner 1 and rotates the toner feeding member 8 in accordance with the consumption of the toner in the developing device 5 to feed the toner 1 to the developing device 5 side. Here, in the present invention, on the toner replenishment path between the toner replenishing device 7 and the developing device 5, a replenishing toner charging means 9 for charging the toner 1 fed from the toner replenishing device 7 while loosening the toner 1 is provided. Supply toner charging means 9
Is constituted by a conductive brush rotatably supported, for example, and a voltage having the same polarity as that of the toner 1 is applied to the conductive brush. The toner 1 fed from the toner replenishing device 7 is loosened by the replenishing toner charging means 9 and the developing device 5
Pre-charging is performed before mixing with the developer 3 inside, so that a charge amount distribution as shown in FIG. 2 can be obtained.

FIG. 2 shows a charge amount distribution of the toner 1 in the developer 3 according to the present invention. Although the absolute value of the charge amount of the toner 1 in the developer 3 depends on the friction time (friction opportunity) with the carrier 2, the charge amount of the toner 1 existing in the developer 3 for a relatively long time The toner replenishing device 7 supplies the developer 3 with respect to the absolute value of (the distribution in which B in FIG. 2 is the mode).
The absolute value of the charge amount of toner 1 immediately after replenishment (distribution with A being the mode in FIG. 2) is sufficient to loosen the particles of toner 1 that have been precharged and aggregated by replenishment toner charging means 9. In this state, the developer is replenished into the developer 3 and the friction time (friction opportunity) with the carrier 2 is increased, so that the distribution close to the distribution in which B in FIG. The amount can be optimized.

[0008]

As described above, according to the present invention, it is possible to prevent the toner mass from being sent to the developing device, and to optimize the toner charge amount in the developing device. A developing device capable of obtaining print quality can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention.

FIG. 2 is a distribution diagram of a toner charge amount in a developer according to the present invention.

FIG. 3 is a schematic configuration diagram showing a conventional technique.

FIG. 4 is a distribution diagram of a toner charge amount in a developer in the related art.

[Explanation of symbols]

1 toner, 2 carrier, 3 developer, 4 photoreceptor,
5 developing device, 6 developing roller, 7 toner replenishing device, 8
... Toner feeding member, 9: replenishing toner charging means.

Claims (3)

[Claims] A two-component developer comprising a toner and a carrier for frictionally charging the toner; and a developer transport member for supplying and transporting the two-component developer toward a photoconductor on which an electrostatic latent image is formed. And a toner replenishing device that contains the toner and feeds and replenishes the toner to the developing device in accordance with consumption of the toner in the developing device. A developing device for an electrophotographic apparatus, comprising: a replenishing toner charging unit for charging a toner fed from the toner replenishing device while loosening the toner on a toner replenishing path between the device and the developing device. 2. The replenishing toner charging means has a brush member rotatably supported.
The developing device of the electrophotographic apparatus according to the above. 3. The developing device for an electrophotographic apparatus according to claim 2, wherein said brush member has conductivity, and a voltage having the same polarity as the charged polarity of said toner is applied to said brush.