JPS6286381A - Developing device - Google Patents

Abstract

PURPOSE:To prevent a toner layer thickness regulating member from toner sticking and to reduce the change with the lapse of time of the pressing force of the toner layer thickness regulating member to a toner carrier by coating the non-contact part of the toner layer thickness regulating member contacting with the toner carrier through the toner with a low surface energy substance. CONSTITUTION:The non-contacting part 6b other than the contacting part 6a of the toner layer thickness regulating member contacting with the a developing roller 4 through the toner is coated with the low surface energy substance suppressing toner sticking. Namely, the non-contact part 6b on which toner sticking may be easily generated, especially the non-contact part close to the contact part 6a, is coated with the substance suppressing the toner sticking and the substance is not applied to the contact part 6a on which toner sticking may not be generated. Consequently, the non-contact part 6b can be prevented from toner sticking, and since the contact part 6a is not coated with the substance, the contact part 6a can be prevented from the peeling of the substance and the change of pressing force can be suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION [1] Hajime Shitono The present invention provides a method for making visible a latent image formed on a latent image carrier by toner on a toner carrier whose layer thickness is regulated by a toner layer thickness regulating member. The present invention relates to a developing device for imaging.

BACKGROUND OF THE INVENTION 2. Description of the Related Art Development devices of the type described below, which are employed in image forming apparatuses such as electronic copying machines, printers, and facsimile machines, are well known.

Development methods that use toner particles alone or toners containing auxiliary components (i.e., -component developers) use conductive magnetic toner, and the charge of the latent image induces charge in the toner particles. Conventionally, the induction development method, in which toner is attached to the latent image using insulating magnetic or non-magnetic toner, and the triboelectric charging method, in which the toner is tribo-electrified to visualize the latent image, are used. However, in either method, the toner layer is made into a thin layer by a toner layer thickness regulating member, and this toner layer is carried to a developing area while being carried on a toner carrier and subjected to development.

However, if a developing device employing the developing method described in -1- is used for a long time, the toner will fuse to the toner layer thickness control section (1) and harden, resulting in a stable thin layer of toner on the toner carrier. It becomes impossible to form a layer, and there is a risk that 11 of 1 hener that has passed through the part where the toner is fixed is insufficient, and that background smearing occurs on the visible image.

For this reason, various structures for preventing the fixation of the 1-ner have been proposed and put into practical use. For example, a structure that devises the shape of the toner layer thickness regulating part (a structure that reduces the suppressing force of ■, or a regulating part) with respect to the toner carrier, or a structure in which the surface of the toner layer thickness regulating member is fused to a lower surface of the toner layer. A typical example is a structure in which the energy substance is coated with 1fr.

However, it is not possible to significantly improve toner adhesion by reducing the suppressing force of the thickness regulating member or by devising its shape. In addition, a method of coating the surface of the thickness regulating member with a low surface energy substance effectively prevents the fusion of 1-ner.11. However, as the low surface energy material in the portion that contacts the toner carrier is abraded and spread over time, the pressing force of the toner layer thickness regulating member against the toner carrier changes, and as a result, 1~
The thickness of each layer changes gradually, making it difficult to maintain a toner layer with a stable thickness for a long period of time.

Purpose An object of the present invention is to prevent toner from sticking to the toner layer thickness regulating member, and to reduce changes over time in the suppressing force of the 1 to 1 layer thickness regulating member against the 1 toner carrier compared to conventional methods. It is an object of the present invention to provide a developer mounting of the type described in .

Structure In order to achieve the above object, the present invention includes a toner carrier having 1-
We propose a configuration in which a portion of the regulating member other than the toner layer thickness regulating member portion that is in contact with the toner layer through the toner, that is, a non-contact portion thereof, is coated with a low surface energy material.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a part of an electronic copying machine having a developing device 1 according to the present invention, a tank 2 of which contains toner (-component developer) 3. As shown in FIG. The toner 3 may be either magnetic 1-hener or non-magnetic 1-hener, but in the example shown in FIG. 1, it is assumed that it is magnetic 1-hener.

Further, in this example, the toner carrier is a cylindrical developing roller 4 driven in the counterclockwise H1 direction.
A magnet 5 in which poles and north poles are alternately magnetized in the circumferential direction is immovably arranged. The 1-ner 3 is attracted to the surface of the developing roller 4 by the magnetic force of the magnet 5, and is conveyed in the direction of rotation while being supported on the surface of the roller 4 as the roller 4 rotates. At this time, the tip region 1 of a toner layer thickness regulating member 6 (see also FIG. 2) is in contact with the developing roller 4 through a thickness of the toner layer. Thickness is regulated. After passing through the toner layer thickness regulating member, the toner forms a thin toner layer 3a and is transferred to the developing roller 4.
The developing roller 4 is conveyed while being supported by the latent image bearing member 7, which is configured as a 16-ram-shaped member 7 rotated in a clockwise direction, that is, the developing area Y). Here, the toner electrostatically transfers to the electrostatic latent image formed on the photoreceptor 7, and the latent image becomes a visible image. The toner that has passed through the development area without being transferred to the photoreceptor is returned to the tank 2 side again.

When a conductive toner (low resistance toner) is used as the toner, when the toner faces the photoreceptor 7, the charges of the latent image induce charges of opposite polarity in the toner, and this causes the toner to adhere to the latent image. However, when an insulating toner (high resistance toner) is used, the toner is charged to a predetermined polarity by friction between the toner and the toner layer thickness regulating member 6 or the developing roller 4. At this time, since the toner is made into a thin layer by the toner layer thickness regulating member 6, the entire toner is uniformly charged. It is also possible to transport the 1-toner by fixing the developing roller 4 immovably and driving the magnet 5 to rotate in the direction of the force, or by driving both to rotate.Also, when non-magnetic toner is used, the magnet It is also well known that you can save 5.

The developing operation is carried out as described in -1-, but if this operation is carried out for a long time, the toner will fuse and adhere to the conventional toner layer thickness regulating member that has not been specially treated over time. As described above, this may deteriorate the quality of the visible image. 1 henna thicker tl'M part 11
The reason why the toner fuses to - is due to the frictional heat generated between the Ijl image roller, 1 henna thicker regulating part +1 and the toner, and the temperature of the regulating member increases by -1. Thing 1: What are the causes and thoughts? 7. However, when the present invention-h examined the toner fusion state in detail, it was found that the toner layer thickness regulating portion (4 portions ('+a 1) rather than 1
- There is no fusion J, H of the
It was found that fusion of 1 hener occurred in the K contact area, more specifically in the contact area [;, and in the surrounding area near I. This means that the temperature of the -Jl contact part near the contact part 6a is the same as that of the contact part 6a.
A and A are almost the same, but the toner existing in the non-contact area moves slowly or stops, so the fusion is accelerated.

This is thought to be due to the fact that the toner moves rapidly in the contact portion 6a, making it difficult for 1 hener to fuse.

The present invention is constructed based on the novel recognition described in -1-, and in the illustrated embodiment, the non-contact portion 61 other than the contact portion 6a of the 1 henna thicker thickness regulating member that contacts the developing roller 4 through the toner. ) (FIG. 2) is coated with a low surface energy material to which toner is difficult to fuse.

In other words, the non-contact area [(1
), in particular, the non-contact areas near the contact area 6a are coated with a substance that can knock up the fusion of toner, and the contact area 6a, where 1-ner adhesion is originally difficult to occur, is not coated with this material. By doing this, it is possible not only to prevent the 1-ner from being fused to the non-contact portion 6b, but also to prevent the contact portion 6a from being scratched since it is not coated with the substances listed in 1) and 2), thereby preventing the development device from being damaged. It is possible to prevent changes in the pressing force of the layer thickness regulating member against the developing roller 4 even when used for a long time, so that the toner layer 3a with a stable thickness can be maintained at all times, and no smudges are produced in the visible image after development. It is possible to suppress defects such as background smearing, and to obtain visible images with stable density.

1 henna thicker regulation j'f1; The tip of the material 6 is extended beyond the state shown in FIG. 4, we also applied a low surface energy material to the contact area at the antinode 7. All other non-contact parts, especially the parts near the contact parts, may be coated with this substance.

As the low surface energy substance, silicone resin, fluoropolymer, etc. can be advantageously used.

Further, as the silicone resin, for example, baking type or room temperature curing type slate silicone can be used as appropriate, but even if it is a room temperature curing type silicone resin, it is forced to
When used after firing at 300' (degrees), its hardness can be increased and wear caused by friction with toner can be suppressed. Commercially available products include Shin-Etsu Chemical's K R27+ and K R
255, KR152, and Toshi silicone (7) S
R2400, SH840, SR2/106, etc. can be advantageously used.

Next, a more specific experimental example will be explained.

Experimental example-! - A stainless steel plate is used as the base material of the toner layer thickness regulating member 6, and the portion that does not come into contact with the developing roller 4 when the regulating member 6 is set as shown in Fig. 1, that is, Fig. 2 The following silicone resin was applied only to the non-contact area 6b shown in (not applied to the contact area 6a).

Silicone resin (5R2400, manufactured by Higashi Ichino Silicone Co., Ltd.) 100 parts by weight Toluene 700 parts by weight This was then heated at 250° C. for 1 hour to bake a silicone film to obtain a toner layer thickness regulating member 6.

The toner layer thickness regulating member that has been fired is set in the developing device shown in Fig. 1, and the electronic copying machine performs a continuous copy test in the manner described above using the following 1 to 1 particle toner. I did it.

Styrene resin 100 parts by weight To magnetite 1 (0.1μ) 60 parts by weight Nigrosine base EX (Orient Chemical Exhibition) 2 parts by weight As a result, even after copying 20,000 copies, there was no white smudge or background stain on the image. There was almost no change in image density, and after the experiment, I removed the toner layer thickness regulating member and observed it, but there was no toner sticking at all.
In addition, there was almost no scraping of the contact portion 6a shown in FIG.

Real J! 1ffl12 As shown in FIG. 3, among the non-contact parts Fi b, the contact part 6
A silicone resin solution treated with lower δ11 is applied only to the portion 6C near a, and this is baked at 200° C. for 1 hour to form the thickness regulating member 6 from 1 to 1).

Silicone resin (Shin-Etsu Chemical KR27]) 100 heavy parts Toluene 700 heavy parts Silicon carbide 5 heavy parts This regulating member 6 was set in the developing device of the electric copying machine shown in Part 1, and the same as in Experimental Example 1. We conducted a continuous copy test of 20,000 sheets using a 1-ner. As a result, even after copying 20,000 copies, no white streaks or background stains occurred in the images, and the image density remained the same as at the initial stage. After the experiment, the toner layer thickness regulating member was observed, and neither toner sticking nor scraping was observed.

几11 Experiment - Example ± The same silicone resin as in Experimental Example 1 was applied to the entire surface (contact and non-contact areas) of a stainless steel toner layer thickness regulating member, and heated at 250°C for 1 hour. The silicone film was fired. When the thus obtained toner layer thickness regulating member was set as shown in FIG. 1 and a continuous copying test was conducted, the image density increased by 1 m after copying approximately 10,000 sheets, and background smear occurred. + After copying 5,000 sheets, the toner layer thickness regulating member was removed and [as it turned out, no toner sticking occurred, but as shown in Figure 4, the toner layer thickness regulating member was in contact with the developing roller. The portion 6a was scraped and the silicone resin coating layer became thin. It is thought that this scraping changed the pressing force of the toner layer thickness regulating member against the developing roller, causing image quality deterioration.

- Experimental Example - Similar to Experimental Example 1, a stainless steel plate was used as the base material of the toner layer thickness regulating member 6, and when the regulating member 6 was moved from 1 to 1 as shown in FIG. Polytetrafluoroethylene enamel (Dupont 852-201 Clear Teflon Enamel, solid content 48% by weight) was applied to the non-contact area 6b shown in Figure 2, and then baked at a temperature of 350°C for 30 minutes. Thus, a henna thickness regulating member 6 was obtained.

This was set in the developing device of the electronic copying machine shown in FIG. 1, and a continuous copy test was carried out using the same 1 hener as in Experimental Example 1. As a result, as in Experimental Example 1, even after copying 20,000 sheets, there was no white smudge, no background smudge, and no change in image density. After the experiment, the toner layer thickness regulating member 6 was removed and observed, but in this case as well, no adhesion of l-toner was observed, and there was almost no scraping of the non-applied area (contact area 6a).
−) It was not possible.

Experimental Example No. L Polytetrafluorocarbon was applied to the base material of the toner layer thickness regulating member only in a portion 6C of the non-contact portion 6b shown in FIG. 3 near the contact portion 6a that contacts the developing roller. 0 hydrophobic silica in ethylene mixture (solid content 30% l-)
．． A coating solution containing 1 part by weight was applied and heated at 400℃ for 7
After baking for 30 minutes, 1 to 4 thick regulating members 6 were obtained. When this was set up as shown in Figure 1 and 20,000 copies were made continuously using the same toner as in Experimental Example 1, the result was that even after copying 20,000 copies, there was no background smudge, and the image density was the same as the initial one. It was the same. After the experiment, the I-na layer thickness regulating member was observed, and there was no toner sticking or scraping.

1-bed comparison experiment - Example - Apply polytetrafluoroethylene enamel, the same as that used in Experimental Example 3, to the entire surface of a stainless steel base material.
The toner layer thickness regulating member obtained by baking at 50°C for 30 minutes was set as shown in Figure 1, the same as in Experimental Example 1!・Continuous copy test was conducted using Gner. As a result, after approximately 10,000 copies were made, the image density increased and background smear occurred. 15
After copying 1,000 sheets, the 1-henner thickness regulating member was removed and observed, and there was no adhesion of the 1-henner. However, as shown in Fig. 4, the contact area 6a with the developing roller was scraped and the coating was poor. The layers were thin.

The present invention can also be applied when the henna carrier is composed of a belt instead of a developing sleeve, and the latent image carrier is composed of a belt-shaped photoreceptor, a dielectric drum, or a dielectric belt instead of a drum-shaped photoreceptor. The same can be said of the present invention, and it can also be applied to developing devices in various image forming apparatuses other than electronic copying machines.

In addition, without coating the entire non-contact portion 6b of the I/N layer thickness regulating member with respect to the toner carrier, the low surface energy material can be coated on the portion where the 1-toner was conventionally likely to adhere, that is, the vicinity of the contact portion 6d. (It is clear from the example in FIG. 3 that J may also be used.The base material of the toner layer thickness regulating member is not limited to stainless steel, but other metals, synthetic resins, etc. can be used as appropriate. Of course.

(According to the present invention, it is possible to prevent the adhesion of the 1-hener to the 1-hener thicker regulating member, and also to suppress the abrasion of the contact portion, so that the contact state of the 1-hener thicker regulating member to the 1-ner carrier can be prevented. It has the ability to reduce hair loss, suppress the occurrence of smudges and background stains on developed images, and maintain stable image density.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a part of an electronic copying machine having a developing device according to the present invention, FIGS. 2 and 3 are perspective views showing a toner layer thickness regulating member, and FIG. 4 is a diagram showing scratches. FIG. 3 is a perspective view showing a toner layer thickness regulating member. 1.Developing device 3...Toner 6...Toner layer thickness regulating member Fig. 2

Claims (3)

[Claims] (1) In a developing device that visualizes a latent image formed on a latent image carrier by toner on a toner carrier whose layer thickness is regulated by a toner layer thickness regulating member, the toner is passed through the toner carrier. The developing device as described above, wherein a portion of the layer thickness regulating member other than a portion of the toner layer thickness regulating member that comes into contact with the toner layer is coated with a low surface energy substance. (2) The developing device according to claim 1, wherein the low surface energy substance is a silicone resin. (3) The developing device according to claim 1, wherein the low surface energy substance is a fluoropolymer.