JP2002304026A - Method and device for forming electrostatic image - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accomplish an electrostatic image forming method and the device being free from the occurrence of defective fixation even at a low temperature, besides, even in the case the size of a toner particle is made small in order to attain high resolution, and then, to attain energy-saving. SOLUTION: (1) As for the electrostatic image forming method comprising electrification, exposure, developing, transfer and fixation processes, transparent fine particles other than color toner are applied on an image forming surface at a time except a color-toner developing time in order to form an image. (2) As for the electrostatic image forming device provided with a photoreceptive member, an electrifying mechanism, an exposure mechanism, a developing mechanism, a transfer mechanism, a fixation mechanism and a cleaning mechanism, the device is provided with a mechanism for applying the transparent fine particles on the image forming surface in addition to the developing mechanism for applying the color toner on the photoreceptive member and developing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electrostatographic image forming method and an electrostatographic image forming apparatus.

[0002]

2. Description of the Related Art In forming an electrophotographic image, in recent years, it has become essential to lower the fixing temperature in order to save energy. However, when the fixing temperature is lowered, the risk of defective fixing increases. This defect occurs more frequently in the halftone portion than in the completely black image portion. In particular, when the toner particles are reduced in size for higher resolution, the defective rate increases. The main reason for this is a decrease in the adhesive force between the toner and the paper due to the lowering of the fixing temperature. It turned out that it was. In other words, when the connection in the horizontal direction is lost, the image is maintained by the adhesive force of a single toner particle to the paper, and when the toner is connected in the horizontal direction and the image is maintained by the adhesive force of a plurality of toner particles. Easier to peel off. When the toner particles are large, the particles are crushed by the pressure at the time of fixing, and there is a high possibility that the particles are entangled with the paper fibers or the toner is connected in the horizontal direction.
This phenomenon cannot be expected if the toner particles are made smaller to achieve high resolution.

[0003]

SUMMARY OF THE INVENTION The present invention provides
Further, it is an object of the present invention to realize an electrostatic photographic image forming method and apparatus which does not cause a fixing failure even when toner particles are reduced in size for high resolution, and to achieve energy saving.

[0004]

Means for Solving the Problems The above problems are as follows:
The invention 12) (hereinafter referred to as Inventions 1 to 12) is solved. 1) In an electrostatographic image forming method having a charging, exposing, developing, transferring, and fixing process, a transparent powder different from the colored toner is applied to the image forming surface in addition to developing a colored toner for forming an image. An electrostatic photographic image forming method characterized by applying. 2) The method for forming an electrophotographic image according to 1), wherein a transparent powder is applied to the photosensitive member after charging and before exposure. 3) The method according to 1), wherein a transparent powder is applied to the photosensitive member after the exposure and before the development. 4) The method according to 1), wherein a transparent powder is applied to the photosensitive member after development and before transfer. 5) The method according to 1), wherein a transparent powder is applied to the image forming member before transfer. 6) The method according to 1), wherein a transparent powder is applied to the image forming member after the transfer. 7) In an electrophotographic image forming apparatus having a photosensitive member, a charging mechanism, an exposure mechanism, a developing mechanism, a transfer mechanism, a fixing mechanism, and a cleaning mechanism, apart from a developing mechanism for applying a colored toner on the photosensitive member and performing development. An electrostatographic image forming apparatus comprising a mechanism for applying a transparent powder to an image forming surface. 8) The electrophotographic image forming apparatus according to 7), wherein a mechanism for applying a transparent powder to the photosensitive member is arranged between the charging mechanism and the exposure mechanism, adjacent to the photosensitive member. 9) The electrostatographic image forming apparatus according to 7), wherein a mechanism for applying a transparent powder to the photosensitive member is arranged between the exposure mechanism and the developing mechanism, adjacent to the photosensitive member. 10) The electrostatographic image forming apparatus according to 7), wherein a mechanism for applying a transparent powder to the photosensitive member is disposed between the developing mechanism and the transfer mechanism adjacent to the photosensitive member. 11) The electrostatographic image forming apparatus according to 7), wherein a mechanism for applying a transparent powder to the image forming member is disposed adjacent to the image forming member at a stage after the development and before the transfer. 12) The electrostatographic image forming apparatus according to 7), wherein a mechanism for applying a transparent powder to the image forming member is arranged between the transfer mechanism and the fixing mechanism adjacent to the image forming member.

Hereinafter, the present invention will be described in detail. In the present invention 1, a process of supplying (coating) a transparent resin powder (transparent powder) to a normal electrophotographic image forming method is added. The transparent resin powder (transparent powder) is the same as the toner except that it does not contain a pigment such as carbon black. CCA (Charge control agent)
May be absent, and wax is better. The particle size is
If it is too large, it will affect the image, and if it is too small, various problems such as aggregation will occur. As a method of supplying, the same method as the development of the toner, a method of spraying with air, a method of dispersing in air by vibration such as ultrasonic waves,
There is a method of directly contacting a member to be applied. The image forming surface refers to a portion where an image is formed with toner on an image forming member such as a photoreceptor, paper, and in some cases, on an intermediate transfer member. As a cause of the fixing failure, when the amount of the toner on the paper is small, the fixing is maintained only by the adhesive force of one toner particle attached to the paper fiber. In this case, the wraparound to the fiber is almost eliminated, and the adhesive strength may be reduced. In the present invention, by supplying the transparent powder onto the paper, even in an image portion with a small amount of toner, a sufficient amount of resin for fixing is present on the paper, and the adhesive force between the paper and the toner can be increased. .

According to the second aspect of the present invention, a transparent powder is applied to the photoreceptor after charging and before exposure. The application method is not particularly limited,
If the transparent powder is charged to a polarity opposite to that of the photosensitive member, it easily adheres to the photosensitive member. In the present invention 3, a transparent powder is applied to the photosensitive member after the exposure and before the development. By having the latent image on the photoreceptor, it becomes possible to supply the transparent powder only to the necessary part. In the invention 4, the transparent powder is applied to the photosensitive member after the development and before the transfer. In the present invention 3, since the transparent powder is applied on the photoreceptor before developing the toner, the latent image on the photoreceptor is slightly affected, and there is a risk that the image quality is deteriorated. Since the toner is developed first, the effect on the image quality is small. In the present invention 5, a transparent powder is applied to an image forming member such as paper before transfer. Since the transparent powder is applied to blank paper, there is no restriction on the application method, and the application is easy. According to the sixth aspect of the invention, the transparent powder is applied to the image forming member such as paper after the transfer. Since the transparent powder is applied after forming the image on the paper, the adverse effect on the image quality can be reduced. The present inventions 7 to 12 are apparatuses for implementing the present inventions 1 to 6. FIG. 1 shows an example of the configuration of an electrostatographic image forming apparatus according to the eighth aspect of the present invention. FIG. 2 shows a configuration example of the electrostatographic image forming apparatus of the ninth invention. FIG. 3 shows a configuration example of the electrostatographic image forming apparatus of the tenth invention. FIG. 4 shows a configuration example of the electrostatographic image forming apparatus of the eleventh invention. FIG. 5 shows a configuration example of the electrostatographic image forming apparatus of the twelfth invention.

[0007]

According to the present inventions 1 and 7, in order to save energy, defective fixing when the fixing temperature is lowered is reduced.
According to the present inventions 2 and 8, since the transparent powder for assisting the fixing can be uniformly supplied to the whole, the effect of reducing the defective fixing is great. According to the third and ninth aspects of the invention, since the transparent powder can be supplied only to the image portion or the outline thereof, the consumption of the transparent powder can be reduced and the cost can be reduced. According to the present inventions 4 and 10, by applying the transparent powder after the development, the influence on the image is reduced, and a high-quality image can be formed. According to the fifth and eleventh aspects of the invention, the transparent powder for assisting the fixing can be uniformly supplied between the image forming member (paper) and the toner, and the effect of reducing the defective fixing is great. According to the present inventions 6 and 12, since the transparent powder is applied after the image is formed on the image forming member (paper), the influence on the image is reduced, and a high quality image can be formed.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of an electrostatographic image forming apparatus having a configuration of the present invention 8.

FIG. 2 is a diagram showing an example of an electrostatographic image forming apparatus having a configuration of the present invention 9;

FIG. 3 is a diagram showing an example of an electrostatographic image forming apparatus having a configuration of the present invention 10;

FIG. 4 is a diagram illustrating an example of an electrostatographic image forming apparatus having a configuration of the present invention 11;

FIG. 5 is a diagram illustrating an example of an electrostatographic image forming apparatus having a configuration of the twelfth embodiment of the present invention.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masanori Suzuki 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company (72) Inventor Tsuneshin Suginama 1-3-6 Nakamagome, Ota-ku, Tokyo Stock F-term in Ricoh Company (reference) 2H027 DD05 EA12 EA18 EB01 EC11 2H134 GA01 GB02 KH01 QA00

Claims (12)

[Claims] In an electrophotographic image forming method having a charging, exposing, developing, transferring, and fixing process, a transparent powder other than the colored toner is used for image formation except when developing a colored toner for forming an image. A method for forming an electrostatographic image, wherein the method is applied to a formation surface. 2. The method according to claim 1, wherein a transparent powder is applied to the photosensitive member after charging and before exposure. 3. The method according to claim 1, wherein a transparent powder is applied to the photosensitive member after exposure and before development. 4. The method according to claim 1, wherein a transparent powder is applied to the photosensitive member after development and before transfer. 5. The method according to claim 1, wherein a transparent powder is applied to the image forming member before transfer. 6. The method according to claim 1, wherein a transparent powder is applied to the image forming member after the transfer. 7. An electrophotographic image forming apparatus having a photosensitive member, a charging mechanism, an exposure mechanism, a developing mechanism, a transfer mechanism, a fixing mechanism, and a cleaning mechanism, wherein a developing mechanism for applying a colored toner on the photosensitive member and performing development. Separately, an electrostatographic image forming apparatus comprising a mechanism for applying a transparent powder to an image forming surface. 8. The electrophotographic image forming apparatus according to claim 7, wherein a mechanism for applying a transparent powder to the photosensitive member is disposed between the charging mechanism and the exposure mechanism adjacent to the photosensitive member. . 9. The electrophotographic image forming apparatus according to claim 7, wherein a mechanism for applying a transparent powder to the photosensitive member is arranged between the exposure mechanism and the developing mechanism adjacent to the photosensitive member. . 10. An electrophotographic image forming apparatus according to claim 7, wherein a mechanism for applying a transparent powder to the photosensitive member is disposed between the developing mechanism and the transfer mechanism adjacent to the photosensitive member. . 11. In a stage after development and before transfer,
8. The electrostatographic image forming apparatus according to claim 7, wherein a mechanism for applying a transparent powder to the image forming member is disposed adjacent to the image forming member. 12. The electrostatographic image according to claim 7, wherein a mechanism for applying a transparent powder to the image forming member is disposed between the transfer mechanism and the fixing mechanism adjacent to the image forming member. Forming equipment.