JPH01142749A - Developing device - Google Patents

Abstract

PURPOSE:To decrease friction and to stably obtain a good image by coating ceramics contg. Ti and/or W atoms on the surface of a toner holding body and control member for forming a thinner layer. CONSTITUTION:A ceramics layer 55A is coated on the surface of a developing roller 55 to a uniform thickness and ceramics layers 57A and 57B are coated on the surface of an elastic blade 57 as well at a uniform thickness. The Ti and/or W atom-contg. ceramics used for this device has particularly high hardness and excellent wear resistance and, therefore, the wear of the developing roller 55 and the elastic blade 57 by the friction between the same is effectively decreased by coating of such ceramics on the same. The good image is thus stably obtd. even if the developing device is operated for a long period of time.

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 apparatus such as an electronic copying machine. relates to a phenomenon device that uses a non-magnetic one-component developer and can stably obtain high-quality images even when operated for long periods 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 machine is equipped with, for example, a two-component developing means for visualizing an electrostatic latent image formed on a photoreceptor, which is an image carrier. 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 of the toner and carrier, which are the developer, 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 extremely high.

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

In a developing bag using such a non-magnetic one-component developing agent, a mixer and a toner supply roller are arranged in a hopper containing toner, and the rotation of these rollers supplies the toner to the developing roller, which is a toner holding body. Along with supplying
An elastic blade serving as a thinning regulating member is brought into contact with the outer periphery of the developing roller, and a thickness of approximately 30 μm is applied onto the developing roller.
A thin toner film layer of about m is formed.

By bringing this toner 1 film layer close to and facing a photoreceptor, which is an image carrier, the electrostatic latent image on the photoreceptor is developed.

By the way, in the above-mentioned developing device using the conventional non-magnetic component developer, since a negative polarity photoreceptor is used, the amount of charge after coating is about +12μ.
A positively charged toner having a ratio of about C/Q is used.

Such a developing system basically uses a high-resistance single-component toner, and the toner is charged by frictional charging between a developing roller and an elastic blade.

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, it has been said that 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 ideal for color printing.

(Problems to be Solved by the Invention) However, in the above-mentioned conventional developing device using a non-magnetic one-component developing agent, during long-term operation,
There was a problem in that the developing roller as a toner holding member and the elastic blade as an HE conversion member were 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.

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 phenomenon device that can stably obtain high-quality images even when operated for a long time using a non-magnetic one-component developer, and that requires less driving torque. There is a particular thing.

[Configuration of U-Ming] (Means for solving the problem) That is, the phenomenon device of the present invention includes a toner holder that holds a non-magnetic one-component toner that is conveyed to develop an electrostatic latent image; , a developing device comprising means for supplying the toner to the toner holding body, and a thinning regulating member for thinning the toner on the toner holding body, the toner holding body and the thinning regulating member; on at least the surface of T
It is characterized by being coated with ceramics containing i and/or W atoms.

(Function) The current (!Jl) device of the present invention has ceramics containing Ti and/or W atoms coated on the surfaces of the toner holder and the thinning regulating member, which improves the long-term stability of copied images and the performance of the device. Excellent driving efficiency.

In other words, since the ceramics have high hardness and excellent wear resistance, wear due to friction of the toner holder and the layer thinning regulating member is reduced, and the developing device remains stable even when operated for a long time. Good images can be obtained.

In addition, since the ceramic has a small coefficient of friction, the friction between the toner holding body and the four-layer regulation member is reduced.
The driving torque of the device can be reduced.

Therefore, according to the developing device of the present invention, a clear image can always be obtained without a decrease in image density or blurring of characters.

(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 example 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 schematic cross-sectional explanatory diagram showing the contact state of the toner holder and the thinning regulating member in the developing device of the present invention, FIG. 5 is a schematic cross-sectional explanatory diagram showing a ceramic plasma CVD coating apparatus for the thinning regulating member, FIG. 6 is a schematic side sectional explanatory view showing a plasma CVD coating apparatus for ceramics on a toner holder, FIG. 7 is a schematic cross-sectional view of the same, and FIG. 8 is a sputtering coating apparatus for ceramics on a thin layer regulating member. It is a schematic cross-sectional explanatory view.

In FIG. 1, a photoreceptor 2 serving as an image carrier is provided in a substantially medium-sized portion 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 static eliminator 8 are arranged in this order.

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 to a fixing device 13 along a conveyance path 11, and after being fixed, the paper is discharged to a paper discharge tray 15 via a paper discharge roller 14.

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

2 and 3, the developing device 5 of the present invention is equipped with a hopper-shaped developing unit 51, and a non-magnetic one-component developer (toner) 52 is stored in the developing unit 51.

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 installed in contact with the developing roller 555, and is configured to rotate in the opposite direction to the rotating direction of the developing roller 55.

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

An elastic blade 57 as a layer thinning regulating member that forms a thin layer of developer on the circumferential surface of the developing row 555 is pressed against the developing row 555 at a pressure of, for example, about 20 to 500 C1/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 is opposed to the photoconductor 2° and can be rotated at variable speeds at a circumferential speed of 1 to 3 times the circumferential speed of the photoconductor 2 by a driving means (not shown), so that the electrostatic latent image is 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 formed 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.

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 collecting blade 58 returns the toner to 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, the surface of the developing roller 55 and/or the elastic blade 57 is made of Ti and /
Alternatively, it is characterized by being coated with ceramics containing W atoms.

That is, as shown in FIG. 4, in the developing device of the present invention, a ceramic layer 55A is provided on the surface of the developing roller 55.
is coated with a uniform thickness, and the surface of the elastic blade 57 is also coated with ceramic layers 57A and 57B with a uniform thickness.

Ceramics is a type of heat-resistant material that usually contains aluminum oxide, silicon oxide, chromium oxide, clay, etc. as main components, but ceramics containing Ti and/or W atoms used in the present invention has particularly high hardness and excellent wear resistance, so by coating with these, it is possible to effectively reduce the wear caused by friction of the developing roller 55 and the elastic blade 57.

The ceramics used for coating in the present invention must contain Ti and/or W atoms, but other constituents include N, C, O, H, and halogen atoms, especially H or halogen atoms. 1 to 40 atoms
It is desirable that the content be atomic%.

In the present invention, the desired effect can be obtained by coating the surface of either the developing roller 55 or the elastic blade 57 with ceramics containing Ti and/or W atoms. A more desirable effect can be obtained by coating both surfaces of 57.

In addition, ceramics containing Ti and/or W atoms,
When the surface of either the developing roller 55 or the elastic blade 57 is coated, the remaining surface to be used can be coated with ordinary ceramics that do not contain 7i and/or W atoms; As ceramics, Si, Ge, AΩ,
By using ceramics containing at least one type of atom selected from B and C, effects such as, for example, toner that is difficult to charge can be sufficiently charged and image quality can be further improved can be expected.

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. If only one side is coated, the elastic blade will be distorted and the dimensional and shape stability will decrease. This is not desirable because of the

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 Ti and/or W atoms. Vacuum deposition, plasma CVD, EC
Examples include methods such as R plasma CVD, thermal CVD, and photoCVD.

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 properties of the substrate, and can easily control the electrical and optical properties of the film. 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 viewing sleeve, and more specifically, a schematic view of a parallel plate type capacitively coupled 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 arranged in a vacuum chamber 101.
It 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, 5IH4, N2, Cl-
While supplying raw material gas such as 13 into the chamber 101 and evacuating the chamber 101 to maintain a vacuum level of 0.05 Torr to 1.0 Torr, power is supplied from the high frequency power source 108 to the high frequency electrode 103 via the matching box 107. Insert.

Then, a glow discharge occurs between the electrodes, the source gas is turned into 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 with reference to FIGS. 6 and 7.

Figure 6 shows the plasma CV of ceramics for the developing roller.
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 maintained at a vacuum level.

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 when handled.

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.

The lower end of each support rod 209 has a female thread (not shown).
A male thread (not shown) is formed at the upper end of the support (developing roller) 213 used for coating.

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

Further, a drive device 214 is provided above the storage chamber 207, and the gear 212 is driven by the 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 reactor 201 in a line.

A pair of flat electrodes 215 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 the reaction chamber 2 passes 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, a plurality of 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 201' is evacuated to about 10-3 Torr.

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 I Torr ~1, 0 Torr, since the support body 213 is grounded through the housing v207, plasma is generated between the flat electrodes 215 and 216 and the support body 213, and the raw material gas A thin film having a composition containing the main constituent elements in the support 213
formed on top.

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.

TiN using the plasma CVD coating equipment described above.
Or to coat TiC, TiCC4, N2, NH3, CH4, C2Ha are used as raw material gas.
, and C2H2, etc. can be used.

In this case, since T i CQ 4 does not have a very high vapor pressure, it is preferable to blow H2 into the container containing TiCQ 4 to force it out of the container.

Therefore, in addition to gases such as TiCΩ4 and N2, H2 is also introduced into the chamber.

Typical conditions for raw material gas, pressure, and electric power used for plasma coating the target composition of the present invention are shown below.

1. TiN source gas TiCU450SCCM N2 - 200 〃 H21000" Pressure 1.0 Torr Power 400W 2. TiC source gas Ti Cn450SCCM C1" 4 100 〃 +12 1000 〃 Pressure 1. QTorr power 400W 3, TiCN Raw material gas TiCΩ4 50SCCM CH450〃 N2 100” H21000〃 Pressure 1.QTorr power 400W 4, WC Raw material gas W Fa 508 CCM CH4100〃 H21000〃 Pressure 1.0 Torr Power 400W Also, Figure 8 shows FIG. 2 is a schematic cross-sectional explanatory diagram 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 DC voltage is applied to 11 parts usually called targets. There is.

In this sputtering coating apparatus, Ar 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 Ar 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, TiN target Ti source gas Ar 10S105 CC50 Pressure 1, Qx 10' Torr power
800W 2, TiC target Ti source gas Ar 10300M CH450" Pressure 1, Qx 10' Torr 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 7i atoms to a thickness of 0.1 to 20 μm using the plasma CVD coating apparatus shown in FIG.

Further, the surface of the developing roller was polished by sandblasting to a surface roughness of 3.0 μmRz, and the surface of the developing roller was coated with Ti atoms using the plasma CVD coating apparatus shown in FIGS. 6 and 7. Ceramics was coated with a thickness of 0°1 to 20 μm.

A non-magnetic one-component toner containing 10% by weight of magnetic powder was stored in the hopper of the developing device in which the above-mentioned elastic sleeve and developing roller were set, and a line load of 20 ka was applied to it. When the apparatus was mounted on a copying machine having the structure shown in Figure 1 and images were formed on 100,000 sheets of paper, the surface roughness of both the elastic sleeve and the ceramic coating layer of the developing roller changed. 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 k(]-CCl.

<Comparative Example> In the above-mentioned test example, paper 10 was prepared under the same conditions as the above-mentioned test example using an elastic blade made of 5US304 that is not coated with ceramics and a developing roller with electroless Ni plating applied to the surface of the aluminum roller. When images were formed on 10,000 sheets, the contact portion of the elastic sleeve with the developing roller wore out by 2.0 μmWJ, and the surface roughness of the developing roller, which had an initial surface roughness of 3.0 μrnRz, decreased to 0.6 μmRz. As a result, the toner transport j 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 ko-c+a, and the load on the driving device was large compared to the test example described above.

[Effects of the Invention] As explained in detail above, the developing device of the present invention has T on at least the surface of the toner holding body and the thinning regulating member.
Since it is coated with ceramics containing i and/or W atoms, the long-term stability of the copied image and the driving efficiency of the device are excellent.

In other words, since the ceramics have high hardness and excellent abrasion resistance, abrasion caused by FJ friction on the toner holder and thinning regulating member is reduced, and the developing device remains stable even when operated for a long time. Good images can be obtained.

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

Therefore, according to the developing device of the present invention, a clear image can always be obtained without a decrease in image density or blurring of characters.

[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 state of contact between the toner holder and the layer 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 52...Toner (non-magnetic one-component developer) 54...
Toner supply means (supply roller) 55, what, toner holding body (
developing roller)

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. The developing device is equipped with a thinning regulating member that thins the layer, characterized in that at least the surfaces of the toner holder and the thinning regulating member are coated with ceramics containing Ti and/or W atoms. developing device. (2) Ceramics used for coating contain N,
The developing device according to claim 1, wherein the developing device contains at least one type of atom selected from C, 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.
Developing device described in item ).