JPH01142752A - Developing device - Google Patents

Abstract

PURPOSE:To obtain a high-grade image without having ground fogging even in the case of using a toner having low electrostatic chargeability by coating ceramics contg. atoms of at least one kind selected from Al, B and C on the surface of a control member for forming a thinner layer as well. CONSTITUTION:The ceramics contg. the atoms of at least one kind selected from Ti and W is coated on the surface of a developing roller 55 as a toner holding body and the ceramics contg. the atoms of at least one kind selected from Al, B and C is coated on the surface of an elastic blade 57 as well as the control member for forming the thinner layer. The above-mentioned ceramics have particularly high hardness and excellent wear resistance; therefore, wear of the toner holding body and the control member for the thinner layer is decreased and the good image is obtd. stably even if the developing device is operated fro a long period of time. In addition, the above-mentioned ceramics have an excellent insulating characteristic and are capable of sufficiently electrostatically charging a toner which is hardly chargeable and, therefore, the high-grade image without having the ground fogging is obtd. even in the case of using the toner having the low chargeability.

Description

Detailed Description of the Invention [Object of the Invention] (Industrial Application Field) The present invention relates to an improvement in a developing device installed in an image forming device such as an electronic copying machine. Even if you use a non-magnetic one-component developer that is difficult to
The present invention relates to a developing device that can stably obtain high-quality images without fog over a long period of time, and that also reduces driving torque.

(Prior Art) In general, a developing device in an image forming apparatus such as an electronic copying device has a two-component developing device, for example, as a developing processing means for visualizing an electrostatic latent image formed on a photoreceptor, which is an image bearing member. Developers using magnetic or magnetic-component type developers are known.

However, in the development processing means using the above-mentioned two-component developer, it is necessary to accurately control the concentration ratio of the developer toner and carrier, whereas in the development processing means using the magnetic one-component developer, However, since the toner contains a dark-colored magnetic material, it is difficult to produce color, and in addition, in any of the development processing means, a magnetic roller is required as a developing roller which is a developer holding member. Therefore, the cost was very high.

Therefore, in order to solve the above-mentioned problems, a development processing means using a non-magnetic one-component developer has recently been proposed.

In a developing device using such a non-magnetic one-component developer, a mixer and a toner supply roller are arranged in a hopper containing toner, and the rotation of these rollers causes the toner to be transferred to the developing roller, which is a toner holding member. At the same time, an elastic blade as a thinning #2 IIJ member is brought into contact with the outer periphery of the developing roller to form a toner/film layer with a thickness of about 30 μm on the developing roller.

The electrostatic latent image on the photoreceptor is developed by bringing this toner thin film layer close to and facing the photoreceptor, which is an image carrier.

By the way, in the above-mentioned developing device using the conventional non-magnetic component developer, since the photoreceptor is of J1 polarity, the amount of charge after coating is approximately -1
A positively charged toner with a charge of about 2 μC/(1) is used.

This type of development method essentially uses a high-resistance single-component toner, and the toner is charged by IJi! between a developing roller and an elastic blade. This is done by +6 charging.

Furthermore, since the toner is conveyed as the toner and the developing roller rotate, it does not require magnetic conveyance unlike a two-component developer or a magnetic-component developer.

Therefore, a conventional developing device using a non-magnetic component developer can produce high-quality images with an extremely simple structure, is advantageous in terms of cost, and is said to be optimal for color printing.

(Problems to be Solved by the Invention) However, in the above-mentioned conventional developing device using a non-magnetic one-component developer, while operating for a long time,
There has been a problem in that the developing roller as a toner holding member and the elastic blade as a layer thinning regulating member are worn out due to friction with the toner, resulting in a noticeable decrease in image density and blurring of characters.

Further, since the elastic blade is made of metal or rubber, there is a problem in that friction with the toner is large and the driving torque of the developing device increases.

Furthermore, there is a problem in that toner that is difficult to charge cannot be sufficiently charged, and when toner with low chargeability is used, only low-quality images with background fogging are obtained.

The present invention was achieved as a result of studies aimed at solving the problems in the conventional developing device described above.

Therefore, an object of the present invention is to provide a developing device that can stably obtain high-quality images without fog over a long period of time even when using a non-magnetic one-component developer that is difficult to charge, and that reduces driving torque. It is about providing.

[Structure of the Invention] (Means for Solving the Problems) That is, the developing device of the present invention includes a toner holder that holds a non-magnetic one-component toner that is conveyed for developing an electrostatic latent image; In a developing device comprising means for supplying the toner to the toner holder and a thinning regulating member for thinning the toner on the toner holder, the surface of the toner holder is coated with a material selected from Ti and W. coating a ceramic containing at least one type of atom containing the ill
The surface of the oxidation regulating member is coated with ceramics containing at least one type of atom selected from A, B, and C.

(Function) In the developing device Y of the present invention, the surface of the toner holder is coated with ceramic gold containing at least one type of atom selected from Ti and W, and the surface of the thin layer v1 member is coated with A.
Coated with ceramics containing at least one type of atom selected from n, B, and C, the long-term stability of copied images and the driving efficiency of the device are excellent, and furthermore, when using toner with low chargeability, Also, high quality II with no background fog! iI images can be obtained.

In other words, since the ceramics have high hardness and excellent wear resistance, wear due to friction of the toner holding body and the layer thinning regulating member is reduced, and the developing device remains stable and good even when operated for a long time. You can get a good image.

Further, since the ceramic has a small coefficient of friction, the friction between the toner holding body and the layer thinning regulating member is reduced, and the driving torque of the developing device can be reduced.

Furthermore, the ceramics have excellent insulating properties and can sufficiently charge toner that is difficult to charge, so even when toner with low chargeability is used, high-quality images without background fog can be obtained.

Therefore, according to the developing device of the present invention, it is possible to always obtain clear images without causing a decrease in image density, blurring of characters, background fogging, etc.

(Example) Examples of the developing device of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a schematic cross-sectional explanatory diagram of an electronic copying machine equipped with the viewing device of the present invention, FIG. 2 is a schematic cross-sectional explanatory diagram showing the current apparatus of the present invention, FIG. FIG. 4 is a schematic cross-sectional explanatory diagram showing the state of contact between the toner holder and the thinning regulating member in the developing device of the present invention, and FIG. 5 is a schematic cross-sectional diagram showing a ceramic plasma CVD coating apparatus for the thinning regulating member. 6 is a schematic side sectional explanatory view showing a ceramic plasma CVD coating apparatus for a toner holder, FIG. 7 is a schematic plan sectional explanatory view of the same, and FIG. 18 is a ceramic sputtering coating apparatus for an H layering regulating member. It is a schematic cross-sectional explanatory view shown.

In FIG. 1, a photoreceptor 2 serving as an image carrier is provided approximately at the center of a copying machine main body 1 so as to be rotatable in the direction of the arrow.

Around the photoreceptor 2, there are
Charging device 3, imaging lens 4, developing device 5, transfer device 6,
A cleaner 7 and a m removal device 8 are sequentially arranged.

Further, an optical system 9 for exposing a document to light is provided on the upper side of the main body 1, and a paper feed cassette 10 is installed on the lower side of the main body 1.

Paper is supplied from this paper feed cassette 10, and the supplied paper is configured to be transported along a transport path 11.

A registration roller 12, a fixing device 13, and a paper ejection roller 14 are arranged along the paper transport direction in the transport path 11. .

Note that 15 in the figure is a paper discharge tray, and 16 is a document table.

When forming an image using the copying machine configured as described above, the optical system 9 irradiates light onto the document on the document table 16, and the reflected light forms an image on the photoreceptor 2 via the imaging lens 4. As a result, an electrostatic latent image is formed on the surface of the photoreceptor 2.

Then, a non-magnetic one-component developer (hereinafter simply referred to as toner) is supplied from the developing device 5 to this electrostatic latent image to make it visible.

On the other hand, paper is supplied from the paper feed cassette 10 and sent between the photoreceptor 2 and the transfer device 6, and the visible image on the photoreceptor 2 is transferred to the paper.

The transferred paper is conveyed along the conveyance path 11 to the fixing device 13, and after being fixed, the sheet is discharged to the paper discharge tray 15 via the paper discharge row 514.

Next, the developing device of the present invention will be described in detail with reference to FIGS. 2 to 4.

2 and 3, the current 4I! of the present invention! Device 5
is equipped with a hopper-like developing unit 51, and a non-magnetic one-component developer (toner) 52 is contained in the developing unit 51.
is stored.

Inside the developing unit 51, a supply roller 5 is provided which supplies toner 52 to a developing roller 55 as a toner holding member.
4 is provided in contact with the developing roller 55, and is configured to rotate in a direction opposite to the rotating direction of the developing roller 55.

Further, within the developing unit 51, a mixer (Wi stirring blade) 53 for stirring the stored toner 52 is rotatably provided.

The developing roller 55 has a layer of developer on its circumferential surface.
Elastic blade 57 as a layer thinning regulating member that forms a layer
are pressed together, for example, at a pressure of about 20 to 500 q/Cm.

The upper end of this elastic blade 57 is held in a conductive state by a holder 56.

Further, a collecting blade 58 for collecting the toner 52 remaining on the surface of the developing roller 55 is in contact with the lower part of the developing roller 55 .

The developing roller 55 faces the photoreceptor 2 and can be rotated at variable speeds at a circumferential speed of 1 to 3 times the circumferential speed of the photoreceptor 2 by a driving means (not shown), and an electrolytic latent image is formed. A direct current bias, an alternating current bias, or a bias that is a combination of direct current and alternating current is applied between the photoreceptor 2 and the developing roller 55.

Next, the operation of this developing device 5 will be explained.

The toner 52 housed in the developing unit 51 is agitated by the rotation of the mixer 53 and the supply roller 54, is conveyed by the supply roller 54, is rubbed against the development roller 55, and is further pressed into contact with the elastic blade 57. , the layer thickness is controlled and triboelectrically charged.

Then, the sufficiently charged toner 52 is conveyed to a position facing the photoreceptor 2, faces the electrostatic latent image formed on the photoreceptor 2, and turns it into a visible image.

Further, the toner 52 remaining on the surface of the developing roller 55 is
The collection blade 58 collects the toner into the developing unit 51 .

Usually, the developing roller 55 is made of a metal surface, and the elastic blade 57 is made of a thin film of metal or rubber, but in the present invention, A1, It is characterized by being coated with ceramics containing at least one type of atom selected from B and C.

That is, as shown in FIG. 4, in the developing device of the present invention, the surface of the developing roller 55 is coated with ceramics 1lJ5.
5A is coated with a uniform thickness -C, and the front and back surfaces of the elastic blade 57 are also coated with ceramics M57A and 57B with a uniform thickness.

Ceramics is a type of heat-resistant material whose main components are usually aluminum oxide, silicon oxide, chromium oxide, and clay.
, B, and C have particularly high hardness and excellent abrasion resistance and insulation properties.
a! Not only can wear due to rubbing be effectively reduced, but even when a toner with low chargeability is used, the toner can be sufficiently charged.

The ceramics used for coating in the present invention are An, B
It is essential to contain at least one kind of atom selected from It is desirable that 10% of ato be contained.

In the present invention, the developing roller 55 is made of ceramic containing at least one type of atom selected from An, B, and C.
By coating the surface of either one of the elastic blades 57 and 57, the desired effect can be obtained.
A more desirable effect can be obtained by coating the surfaces of both the developing roller 55 and the elastic blade 57.

Furthermore, when the surface of either the developing roller 55 or the elastic blade 57 is coated with ceramics containing at least one type of atom selected from AJJ, B, and C, the remaining surface of the other is coated with ΔA, B, and C. In this case, the other ceramic may be coated with at least one atom selected from Tr, w, s; and Ge. By using ceramics containing seed atoms, effects such as further improvement and improvement of image quality can be expected, for example.

In addition, when coating the surface of the elastic blade 57 with ceramics, it is desirable to coat both the front and back sides with ceramics. Coating only on one side causes distortion of the elastic blade and reduces dimensional and shape stability. This is not desirable because it may occur.

A method of coating a developing roller and/or an elastic blade with ceramics will be described below.

In the method of the present invention, the developing roller and/or the elastic blade are coated with ceramics containing at least one type of atom selected from AU, B, and C. sputtering, ion blating, vacuum evaporation, plasma CVD, ECR plasma? Examples include methods such as CVD1 thermal CVD and 5-photo CVD.

Among these methods, this method has the following advantages: it has good film adhesion, can be processed at relatively low temperatures, does not damage the characteristics of the substrate, and can easily control the electrical and optical characteristics. For the present invention, plasma CVD
and sputtering methods are most suitable.

FIG. 5 is a schematic cross-sectional view of a plasma CVD coating apparatus for a developing sleeve, and more specifically, a schematic view of a parallel plate type capacitive coupling type plasma CVD apparatus.

In FIG. 5, a flat ground electrode 102 and a high frequency electrode 103 are installed facing each other in a vacuum chamber 101, and a substrate 104, such as a metal elastic blade, is placed on the flat ground electrode 102.

Then, the chamber 101 is heated by a vacuum pump (not shown).
After evacuating the inside to about 10' Torr, the substrate 104 is heated to about 150 to 450° C. by the heater 105 attached to the flat ground electrode 102.

Next, from the gas inlet 106, A (CH3) 3, N2
, H2, etc. are supplied into the chamber 101, and while being evacuated to maintain a vacuum of 0.05 Torr to 1.0 Torr, a source gas such as H2 is supplied to the high frequency electrode 103 from the high frequency power source 108 via the matching box 107. Immerse yourself in power.

Then, a glow discharge occurs between the M poles, the source gas becomes plasma, and a ceramic thin film is formed on the substrate 104.

Next, plasma CVD of ceramics was applied to the developing roller.
The coating method will be explained according to FIGS. 6 and 7. 1. FIG.
FIG. 7 is a schematic side sectional explanatory view of the D coating apparatus, and FIG. 7 is a schematic plan sectional explanatory view thereof.

In FIGS. 6 and 7, a reaction chamber 201 having a rectangular cylindrical planar cross section is evacuated through an exhaust port 202 by a mechanical booster pump, an oil rotary pump (not shown), etc. It is designed to be held in a vacuum.

Further, various raw material gases are introduced into the reaction chamber 201 through a gas introduction port 205.

A storage chamber 207 is installed above the reaction chamber 201 via an insulator 206, and this storage chamber 207 is electrically insulated from the reaction chamber 201 by the insulator 206.

Further, the storage chamber 207 is partitioned from the reaction chamber 201 by a partition plate 208.

A plurality of support rods 209 are inserted through the partition plate 208 with the longitudinal direction thereof being perpendicular.

A collar 210 is fitted and fixed to each support rod 209, and by locking the collar 210 to the partition plate 208, each support rod 209 is prevented from falling out.

A gear 212 as a driving means is fitted to the upper end of each support rod 209, and a presser foot 211 fitted and fixed to each support rod 209 below the gear 212 causes the gear 212 to be attached to each support rod 209. Supported.

Adjacent gears 212 are in mesh with each other, and when the central gear is rotationally driven by the drive device 214, all gears 212 rotate and each support rod 209 rotates. There is.

A screw (not shown) is attached to the lower end of each support rod 209.
A male screw (not shown) is formed at the upper end of the support (clear image roller) 213 which is formed and cured and is subjected to coating.

Therefore, the support body 213 is attached to each support rod 209 by screwing these screws together.

Further, a drive #J device 214 is provided above the storage chamber 207, and the gear 212 is driven by this drive device 214.
When the support 213 rotates, the support 213 rotates about its axis.

As shown in FIG. 7, the supports 213 are arranged substantially in the center of the reaction chamber 201 in a line.

A pair of flat plates 1215 and 216 are provided oppositely on both sides of the row of supports 213.

Since the flat electrodes 215 and 216 have a large number of holes, the reaction chamber 20 can be connected through the gas inlet 205.
The raw material gas introduced into i enters the reaction chamber 2 through this hole.
It is supplied to the center of 01.

Further, the flat electrodes 215 and 216 are connected to the reaction chamber 201.
It is attached to the reaction chamber 201 so as to have the same potential as , and is connected to a high frequency power source 218 via a matching box 217.

When operating the plasma CVD coating apparatus configured as described above, first, several supports 213 are installed in the reaction chamber 201, and then the supports 213 are rotated at an appropriate speed by the drive device 214. Then, the inside of the reaction chamber 20i is evacuated to about 10°3'j orr.

While continuing the evacuation in this way, the raw material gas is introduced through the gas inlet 205 to bring the inside of the reaction chamber 201 to zero, for example.
．． When the pressure is adjusted to 1 Torr to 1,0 Torr, since the support body 213 is grounded through the storage chamber 207, plasma is generated between the flat plate m[215 and 216 and the support body 213, A thin film having a composition containing the main constituent elements in the source gas is formed on the support 213.

In this case, since the support body 213 is rotating, the thin film is uniformly formed on the circumferential surface of the support body 213.

In order to coat ceramics using Al2O3 or AflN as a matrix using the plasma CVD coating Rtff described above, A as a raw material gas is used.
fL(CH3)3 or Ahi(C2H5)3, N2.0
2 and Ntl+, etc. can be used.

In this case, Au(CH3)3 or A(C2H5)
Since the vapor pressure of '3 is not very high, it is preferable to blow 112 into the container containing these and forcibly expel them from the container as a carrier gas.

Therefore, Aft (CH3)3, N
In addition to gases such as 2 and 02, H2 is also introduced.

Hydrocarbons such as CH4, C2He, and C2H2 and H2 are used as raw material gases for coating ceramics containing C atoms such as diamond, graphite, carbon polymer films, and amorphous carbon.

Furthermore, raw material gases for coating ceramics based on BN or BC include B2 Ha,
BF3, and BCC10, N2, NH3, CH
4 and C2He.

Typical conditions for raw material gas, pressure, and power used to plasma coat the composition targeted by the present invention are shown below.

1. A sentence 203 Raw material gas A base (CH3) 3 30SCCM (1+100〃H21000n pressure)] 1.0l-or
r Power 400W 2, AAIN Raw material gas Au (CH3)3 30SCCM N2 200 // H21000〃 Pressure 1.0Torr Power 400W 3. Diamond raw material gas CH41108CC 12 500〃Pressure 5.0Torr Power 1KW Strip temperature 800℃ 4 , graphite raw material gas C)-1450SCCM H2200〃 Pressure 1.0 TOrr Power 500W Substrate temperature reaction 500°C 5.8N Raw material gas B2 He 10SCCM He 200// N2 400 Il Pressure 1. □Torr Power 200W 6, BC Raw material gas B2 Ha '10SCCM He 200// CH3100〃 Pressure 1.0Torr Power 200W Note that in 3 and 4 above, carbon-based ceramics such as diamond have a lower surface area than other ceramics. Although the pressure and power required during film formation are high, lowering these values results in amorphous carbon or graphite.

Furthermore, in 5 and 6 of the Book of Ju, when B2Hs is used as the raw material gas, 0.1 to 40 at
omic% of hydrogen is contained, and when 8F3 is used, the same amount of F is contained in the film.

Therefore, since the hardness of the film changes somewhat depending on the content thereof, the conditions of the raw material gas may be selected so as to obtain the desired hardness.

Generally, when H and F are low, the hardness of the film is high, and such a film can be obtained by increasing the substrate temperature and high frequency power.

Moreover, FIG. 8 is a schematic cross-sectional explanatory view showing a ceramic sputtering coating apparatus for an elastic sleeve.

The apparatus shown in Fig. 8 is almost similar to the plasma CVD apparatus shown in Fig. 5 above, except that the raw material is solid and high frequency or self-current voltage is applied to 11 parts usually called targets. There is.

In this sputtering coating apparatus, Δr gas or a mixture of raw material gas in some cases is introduced from the gas inlet 106, and these gases turn into plasma, and Δr ions attack the target metal in atomic or molecular form. After being pounded out in a shape, ceramics of various compositions are formed while reacting in a plasma of a reactive gas, and are adhered to the substrate 104 as a thin layer.

Typical conditions for targets, raw material gases, pressures, and electric power used for sputtering coating the target composition of the present invention are shown below.

1, Al2O3 target Sintered Al2O3 source gas Ar 10800M Pressure 1゜0x10゜3Torr Power 800W 2, 8N Target Crystalline boron nitride source gas Ar 108CCM Pressure 1, Qx 10-3Torr power
800W Test examples and comparative examples specifically showing the effects of using the developing device of the present invention will be described below.

(Test Example) Both the front and back surfaces of an elastic blade made of SUS304 were coated with ceramics containing Ai atoms to a thickness of 0.degree. 1 to 20 .mu.m using the plasma CVD coating apparatus shown in FIG.

In addition, the surface of the aluminum roller was sandblasted to a surface roughness of 3. The surface of the developing roller, which had been polished to OumRz, was coated with ceramic containing An atoms to a thickness of 0.degree. 1 to 20 .mu.m using the plasma CVD coating apparatus shown in FIGS. 6 and 7.

A non-magnetic one-component toner containing 10% by weight of magnetic powder is stored in the hopper of the developing device in which the above elastic sleeve and developing roller are placed, and a line load of 20 kg is applied to the toner. was mounted on a copying machine having the structure shown in Fig. 1, and images were formed on 100,000 sheets of paper. As a result, the ceramic coating layers of the elastic sleeve and the image roller both showed changes in surface roughness. Even after 100,000 sheets of images were formed, good images could be continuously obtained.

Further, when the driving torque in the developing device during image formation was measured, it was 1.8 kg-cm.

Next, the composition of the non-magnetic one-component toner was changed to a positively charged non-magnetic one-component toner containing 4.0% by weight of carbon and 4% by weight of other additives in a styrene-acrylonitrile copolymer. When an image was formed under the same conditions as above, a clear image without background fog could be obtained as in the above.

In addition, when the amount of charge of the toner in this case was measured, it was found to be 1
It was extremely sufficiently charged at 2 μC/Cl.

(Comparative example) In the above test example, a developing roller without ceramic coating (JS304 elastic blade and an aluminum roller with electroless Ni plating on the surface) was used under the same conditions as the above test example. When images were formed on 100,000 sheets of paper, the contact portion of the elastic sleeve with the developing roller wore out by 2.0 μm, and the developing roller had an initial surface roughness of 3.OumRz, which decreased to 0. Since the toner density decreased to .6 μmRz, the amount of toner conveyed on the developing roller decreased, and it was not possible to obtain a sufficient image density in subsequent image formation.

Further, when the driving torque in the developing device during image formation was measured, it was as high as 2.5 kq/cn+, and the load on the driving device was large compared to the above-mentioned test example.

Furthermore, the composition of the non-magnetic one-component toner was changed to 4.0% by weight of carbon based on the styrene-acrylonitrile copolymer.
When an image was formed under the same conditions as described in "L" except that the toner was changed to a positively charged non-magnetic one-component toner containing 4% by weight of the additive described above, the charge amount of the toner was 10%.
The μC/Q was low, and background fog was seen in the image.

[Effects of the Invention 1] As explained in detail above, the developing RPf of the present invention has at least one member selected from I and W on the surface of the toner holder.
Since the ceramic containing the species atoms is coated, and the surface of the thinning regulating member is coated with the ceramic containing at least one kind of atoms selected from A, B, and C, the copied image is stable for a long time. Furthermore, even when using toner with low MN properties, high-quality images without background fog can be obtained.

Of course, the ceramics have high hardness and have a hardness of rr4.
Since it has excellent abrasion resistance, abrasion due to friction of the toner holding body and the layering regulating member 7a is reduced, and even if the current zero apparatus is operated for a long time, stable and good images can be obtained.

Further, since the ceramic has a small coefficient of friction, the friction between the toner holding body and the layer thinning regulating member is reduced, and the driving torque of the developing device can be reduced.

Moreover, the ceramics have superior insulating properties, and can charge toner that is difficult to charge by a minute.
Even when toner with low chargeability is used, 1 q of high-quality images without background fog can be produced.

Therefore, according to the developing device of the present invention, it is possible to always obtain clear images without causing a decrease in image vitality, blurring of characters, background fogging, etc.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional explanatory diagram of an electronic copying machine equipped with the developing device of the present invention, FIG. 2 is a schematic cross-sectional explanatory diagram showing the developing device of the present invention, FIG. 3 is a front explanatory diagram of the same part, and FIG. 5 is a cross-sectional explanatory view showing the contact state of the toner holder and the thinning regulating member in the developing device of the present invention, FIG. 6 is a schematic side sectional explanatory view showing a ceramic plasma CVD coating apparatus for a toner holder, FIG. 7 is a schematic plan sectional explanatory view of the same, and FIG. 8 is a schematic illustrating a ceramic sputtering coating apparatus for a thin layer regulating member. It is a cross-sectional explanatory view. 5...Developing device

Claims (3)

[Claims] (1) A toner holder that holds non-magnetic one-component toner conveyed to develop an electrostatic latent image, a means for supplying the toner to the toner holder, and a means for supplying the toner to the toner holder, and a means for supplying the toner to the toner holder. In the developing device, the surface of the toner holder is coated with ceramics containing at least one type of atom selected from Ti and W, and the layer thickness regulating member is configured to reduce the thickness of the layer. A on the surface of the member
1. A developing device coated with ceramics containing at least one type of atom selected from L, B, and C. (2) Ceramics used for coating contain N,
The developing device according to claim (1), characterized in that the developing device contains at least one type of atom selected from O, H, and halogen. (3) Claims (1) and (2) characterized in that the ceramic used for coating contains 1 to 40 atomic% of H or halogen atoms.
) The developing device described in item 1.