JPH11149214A - Developing method in electrophotography - Google Patents

Abstract

PROBLEM TO BE SOLVED: To guarantee stable and proper printing density and printing quality. SOLUTION: This developing method comprises a procedure S2 using first large diameter toner for a first developing device, a procedure S3 using second small diameter toner for a second developing device, a procedure S4 using the first toner in the first rotation period of a photoreceptive drum so as to transfer an original picture pattern onto a first recording medium, and a procedure S5 using the second toner in the second rotation period of the photosensitive drum so as to superimposing transcribe the same original picture pattern onto the first recording medium.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing method for electrophotography, and more particularly to a developing method for electrophotography using only toners of the same color.

[0002]

2. Description of the Related Art In recent years, a plurality of developing devices containing toners having different colors and different characteristics have been arranged, and those which selectively use these developing devices have been gradually used.

A conventional developing method for electrophotography will be described in detail with reference to the drawings.

FIG. 2 is a side view showing an example of the prior art. The developing method in the electrophotography shown in FIG.
a and 2b, which are always separated from the photoreceptor 1 by springs 4a and 4b, respectively, and by urging the solenoids 5a and 5b, the developing units 2a and 2b are arranged.
2b can selectively take the operating position close to the photoreceptor 1.

As shown, when the developing device 2b is selected by the solenoid 5b, the electrostatic latent image formed on the surface of the photoreceptor 1 is developed by the developing device 2b, and the toner image is transferred to the transfer charger. It is transferred to the transfer material at the position 1c. At this time, the residual toner remaining on the surface of the photoreceptor 1 without being transferred to the transfer material is scraped off to the position of the cleaning device 3b and discharged by the transport screw 8.

When the developing device 2a and the cleaning device 3a are used, the developing device 2a and the cleaning device 3b are brought to an operation position close to the photosensitive member 1 by a control means (not shown), and the developing device 2b and the cleaning device 3b are separated from the photosensitive member 1. To retreat. (See, for example, Japanese Utility Model Laid-Open No. 62-74249)

[0007]

In the conventional developing method for electrophotography described above, even if the particle size of the toner is made uniform, the toner is not sufficiently developed depending on the performance of the photoreceptor, and recording is performed as the printing speed increases. Since the transfer time to the medium is shorter, there is a drawback that the print density and quality are limited.

[0008]

According to a first aspect of the present invention, there is provided a developing method for electrophotography having a plurality of developing units, wherein the first developing unit has a first particle having a large particle diameter.
And a procedure in which a second toner having a small particle diameter is used in a second developing device, and an original image pattern is formed by using a first toner during a first rotation period of a photosensitive drum. The same original image pattern is transferred to the recording medium by using the second toner during the second rotation period of the photosensitive drum.
And superimposing the image on a recording medium.

According to a second aspect of the present invention, in the electrophotographic development method according to the first aspect, the first toner and the second toner have the same color.

According to a third aspect of the present invention, there is provided the electrophotographic developing method according to the first aspect, wherein the particle diameter of the first toner is 1%.
The particle diameter of the second toner is selected to be 0 to 12 μm, and the particle diameter of the second toner is selected to be 8 to 10 μm.

According to a fourth aspect of the present invention, there is provided the electrophotographic developing method according to the first aspect, wherein the portion where the first toner is not completely applied on the photosensitive drum during the first rotation period, or a portion having a large particle diameter. The second toner is allowed to enter even a small portion where the first toner cannot enter.

[0012]

Next, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a flowchart showing one embodiment of the present invention. The developing method for electrophotography shown in FIG. 1 is the same as the developing method for electrophotography having a plurality of developing units.
Using the first toner having a large particle diameter in the developing device of step S2
And a step S3 of using a second toner having a small particle diameter in the second developing device, and transferring the original image pattern to the first recording medium using the first toner during the first rotation period of the photosensitive drum. Step S4 and the second rotation period of the photosensitive drum during the second rotation period.
And transferring the same original image pattern onto the first recording medium in a superimposed manner by using the above toner.

The colors of the first toner and the second toner are the same, for example, black. The particle size of the first toner is 10
When the particle diameter of the second toner is selected to be 8 to 10 μm, the portion where the first toner cannot be completely applied on the photosensitive drum during the first rotation period or the first toner having a large particle diameter is removed. The second toner enters even a small portion without entering, and stable and appropriate print density and quality are guaranteed.

[0015]

The development method for electrophotography according to the present invention is as follows.
Since the toner is transferred twice to one recording medium, there is an effect that stable and appropriate print density and quality are guaranteed.

[Brief description of the drawings]

FIG. 1 is a flowchart illustrating an embodiment of the present invention.

FIG. 2 is a side view showing an example of the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photoreceptor 2a Developing device 2b Developing device 3a Cleaning device 3b Cleaning device 5b Solenoid

Claims (4)

[Claims] In a developing method for electrophotography having a plurality of developing devices, a first developing device uses a first toner having a large particle size, and a second developing device uses a second toner having a small particle size.
A procedure for transferring the original image pattern to the first recording medium using the first toner during the first rotation period of the photosensitive drum, and a procedure for transferring the original image pattern to the first recording medium during the first rotation period of the photosensitive drum. Transferring the same original image pattern onto the first recording medium by superimposing the same original pattern using the second toner. 2. The method according to claim 1, wherein the first toner and the second toner have the same color. 3. The particle size of the first toner is 10 to 12 μm.
2. The method according to claim 1, wherein the particle diameter of the second toner is selected to be 8 to 10 [mu] m. 4. The method according to claim 1, further comprising: a step in which the first toner cannot be completely placed on the photosensitive drum during the first rotation period; and a step in which the first toner having a large particle diameter cannot enter. 2. The method according to claim 1, wherein the toner is introduced.