JP2002278251A - Toner supply roller, and developing device and image forming device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toner supply roller by which an image free of trouble such as pitch unevenness and density unevenness can be obtained, and a developing device and an image forming device which use the toner supply roller. SOLUTION: The toner supply roller, which supplies toner to a developing roller by abutting against the developing roller for forming a visible image by conveying toner carried on its surface to an image forming body, is equipped with a shaft 11 as its core and a foamed elastic body layer 12 which is formed cylindrically on the outer peripheral surface of the shaft 11, has successive air bubbles formed inside and is closed on the outer peripheral surface so that the air bubbles are not linked with the outside. Further, the foamed elastic body layer 12 has many fine projections formed on its outer peripheral surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device for an electrophotographic or electrostatic recording type printer, which forms a visible image on the surface by conveying toner to an image forming body such as a photoreceptor or paper. The present invention relates to a toner supply roller for supplying toner to a phenomenon roller, and a phenomenon device and an image forming apparatus using the same.

[0002]

2. Description of the Related Art In recent years, a conductive roller system has been widely adopted as a developing roller and a toner supply roller used in a developing device arranged in a phenomenon process in an electrophotographic apparatus such as an electrocopier, a laser beam printer, and a facsimile. Is coming. In such a method, the toner is frictionally charged by rubbing the toner supply roller against the developing roller. Therefore, the toner supply roller has a stable friction property (pressing force) with the developing roller and a high toner supply to the frictional portion. Is required. Conventionally, a foamed elastic material obtained by foaming rubber, urethane, or the like is generally used for this type of toner supply roller.

[0003]

However, the present inventors have studied the performance of a conventional toner supply roller made of a foamed elastic material, and found that an image defect due to pitch unevenness or density unevenness occurs in a developed image. Turns out there are cases. The present invention has been made in view of such a conventional situation, and includes a toner supply roller made of a foamed elastic material, which can obtain an image without defects such as pitch unevenness and density unevenness, and the toner supply roller. And an image forming apparatus.

[0004]

Means for Solving the Problems The present inventors have examined the toner supply roller that has caused the above-mentioned image defects, and as a result, have found that the surface of the foamed elastic layer of the toner supply roller has
Because the open cells inside are open, the toner to be supplied to the developing roller enters the foamed elastic layer, and the amount of toner supplied to the developing roller fluctuates, resulting in uneven density in the image. Found to occur.

If there is no such opening on the surface of the foamed elastic layer of the toner supply roller, the toner does not enter the foamed elastic layer, but the amount of toner supplied to the developing roller is not sufficient. It was found that the density was uneven because of sufficient density.

[0006] By eliminating the above-mentioned opening on the surface of the foamed elastic layer of the toner supply roller and providing a large number of minute projections on the surface of the foamed elastic layer of the toner supply roller that do not communicate with internal bubbles. It has been found that a good image free from defects such as uneven density can be obtained.

As a result of further study, when the size, height, number density, and occupation area of the microprojections are made appropriate, and the hardness and surface friction resistance of the foamed elastic material layer are made appropriate, It has been found that an image without defects can be formed. The present invention has been made based on such findings.

[0008] That is, according to the present invention, the above-mentioned problem is solved as follows. (1) a toner supply roller that contacts a developing roller that forms a visible image by transporting the toner carried on the surface to the image forming body and supplies the developing roller with the toner; The shaft is formed in a cylindrical shape on the outer peripheral surface, and has open cells inside, and on the outer peripheral surface, the air bubbles are sealed so as not to communicate with the outside,
And a foamed elastic body layer on which a large number of microprojections are formed.

(2) In the above item (1), the height of the fine projections is increased toward the center of the surface of the outermost layer of the foamed elastic material layer.

(3) In the above item (1) or (2), at least one of the number density of the microprojections and the cross-sectional area of the base portion is set to be closer to the center of the surface of the outermost layer of the foamed elastic layer. Small.

(4) In any one of the above items (1) to (3), the size equivalent to the diameter of the base of the microprojection is 3 mm or less (not including 0 mm), and the height is 1 mm or less (0 mm). Is not included).

(5) In any one of the above items (1) to (4), the occupied area ratio of the fine projections to the surface area of the outermost layer surface of the foamed elastic body is set to 60% or less (not including 0%).

(6) In any one of the above items (1) to (5), the coefficient of frictional resistance of the surface of the outermost layer of the foamed elastic material layer is set to 0.1.
4 to 3.0.

(7) In any one of the above items (1) to (6), the compression spring constant of the foamed elastic material layer may be 0.25 to 5.0 N.
/ Mm.

(8) The toner supply roller according to any one of the above items (1) to (7) is mounted on the developing device.

(9) The developing device of the above item (8) is mounted on the image forming apparatus.

[0017]

FIG. 1 is a schematic longitudinal sectional front view schematically showing a developing device of a laser printer having a toner supply roller according to the present invention.

This developing device cleans the surface of the photoreceptor (1) by 1
After being uniformly charged by the next charger (2), an image signal transmitted from a control unit (not shown) is converted into a light signal using an LED array print head (3), and this is converted into a photoconductor.
The surface of (1) is exposed to form an electrostatic latent image, which is housed in a toner cartridge (4) and is transferred via a toner supply roller (5) and a phenomenon roller (6). Photoconductor
The toner is developed by the toner supplied in (1) to form a toner image.

The toner image formed on the surface of the photoreceptor (1) is transferred to a paper surface supplied from a paper magazine (7) by a transfer charger (8) and fixed by a heat fixing unit (9). The paper is transported and discharged in the direction of the arrow. The photoreceptor (1) after the transfer is returned to an initial state by the cleaning unit (10).

FIG. 2 shows an embodiment of the toner supply roller (5) of the present invention. The toner supply roller (5) has a shaft (11) serving as a core, a cylindrical shape formed on the outer peripheral surface of the shaft (11), and has open cells therein. A foamed elastic layer (12) closed so as not to communicate with the outside.

On the outermost layer surface of the foamed elastic layer (12),
The reason that the internal open cells are closed so as not to communicate with the outside is that if the open cells are open on the outer peripheral surface, the toner (4) enters the inside and the toner (4) is difficult to be transported. This is because there is a problem that the hardness becomes too high due to inconvenience or clogging of the toner that has entered inside.

As shown in FIG. 3, on the outermost layer surface of the foamed elastic layer (12), there are formed a large number of minute projections (12a) having no opening communicating with the internal open cells on the surface.

The size of a diameter equivalent to the diameter of the base of the minute projection (12a) (the diameter of a non-circular one approximates a circle) is 3 mm.
Below (excluding 0 mm), preferably 0.5 to 2 mm. If this size exceeds 3 mm, the toner (4)
Is not sufficiently triboelectrically charged.

The height of the minute projection (12a) is 1 mm or less (0 mm
Is not included), preferably 0.1 to 0.5 mm. If the height exceeds 1 mm, there is a disadvantage that the toner (4) is not sufficiently conveyed.

The microprojections (12a) may have a slightly higher height at the center of the surface of the foamed elastic layer (12), or may have one or both of the number density and the cross-sectional area of the base. Is preferably small. That is, the toner supply roller
When (5) is compressed by the phenomenon roller (6), the size of the void for accommodating the toner (4) formed by the minute projections (12a) interposed therebetween is determined by the foamed elastic layer. (1
It is preferable that the center of the surface in 2) be larger.

This is because, when the toner supply roller (5) is operated, the foam elastic layer (12) rotates while being compressed by the developing roller (6), and enters between the rollers (5) and (6). toner
(4) is gradually discharged toward the outer side in the axial direction of the rollers (5) and (6), and the central portion tends to be short of toner. This is corrected to make the supply of toner (4) uniform. This is because it is effective in doing so.

The compression spring constant of the foamed elastic material layer (12) is set to 0.1.
25 to 5.0 N / mm, preferably 0.3 to 3.0 N / mm
mm, particularly preferably 0.4 to 1.5 N / mm. If the compression spring constant is less than 0.25 N / mm, the toner (4) is not sufficiently triboelectrically charged. If the compression spring constant is more than 5.0 N / mm, the toner (4) is greatly damaged. Because there is.

The coefficient of frictional resistance of the outermost layer surface of the foamed elastic material layer (12) is preferably 0.4 to 3.0, and more preferably 0.4 to 2.5. If this frictional resistance coefficient is less than 0.4,
This is because there is a disadvantage that the toner cannot be conveyed because the slip is too large, and if it exceeds 3.0, the damage to the toner is increased, which causes a disadvantage that the toner is easily deteriorated.

The occupied area ratio of the minute projections (12a) to the total surface area of the outermost layer surface of the foamed elastic layer (12) is preferably 60% or less (excluding 0%). This microprojection (12a)
If the occupied area ratio exceeds 60%, there is a disadvantage that the toner is not uniformly conveyed.

Such a foamed elastic body forming the toner supply roller (5) may have the above-mentioned characteristics, such as ester-based polyurethane foam, ether-based polyurethane foam, nitrile rubber, ethylene propylene rubber, and the like. Rubber material-based foams such as ethylene propylene diene rubber, styrene butadiene rubber, butadiene rubber, isoprene rubber, natural rubber, silicone rubber, acrylic rubber, chloroprene rubber, butyl rubber, and epichlorohydrin rubber can be used. These rubber materials may be used alone or as a foam in combination of two or more. Among them, ester polyurethane foam, ether polyurethane foam, nitrile rubber foam, ethylene propylene rubber foam, ethylene propylene diene rubber foam, and silicone rubber foam are particularly preferable.

The toner supply roller (15) of the present invention may be conductive, and a conductive roller is provided on the outside of a good conductive shaft in the same manner as conventionally used as a conductive toner supply roller. It can be made by forming a foamed elastic layer.

The foamed elastic material layer (12) is made of a foamed elastic material which is made conductive by adding a conductive agent to an appropriate foamed elastic body.

As a conductive agent added when imparting conductivity to the foamed elastic body, an ionic conductive agent or an electronic conductive agent is used. Examples of the ionic conductive agent include tetraethylammonium, tetrabutylammonium, dodecyltrimethylammonium (eg, lauryltrimethylammonium), hexadecyltrimethylammonium, octadecyltrimethylammonium (eg, stearyltrimethylammonium), benzyltrimethylammonium, and a modified fatty acid dimethylethylammonium. Perchlorate, chlorate, hydrochloride, bromate, iodate, borofluoride, sulfate, ethyl sulfate, carboxylate, sulfonate and other ammonium salts, lithium, sodium, Perchlorates, chlorates, hydrochlorides, bromates, iodates, borofluorides, trifluoromethyl sulfates of alkali metals and alkaline earth metals such as potassium, calcium and magnesium Salts, and sulfonic acid salts.

Examples of the electronic conductive agent include conductive carbon such as Ketjen black and acetylene black; SA
F, ISAF, HAF, FEF, GPF, SRF, F
Rubber carbon such as T and MT: carbon for oxidation-treated ink, pyrolytic carbon, natural graphite, artificial graphite; conductive metal oxides such as tin oxide, titanium oxide and zinc oxide; nickel, copper, silver, Examples thereof include metals such as germanium.

These conductive agents may be used alone or in combination of two or more. The addition amount is not particularly limited, but in the case of the ionic conductive agent, usually 0.01 to 5 parts by mass, relative to 100 parts by mass of the rubber-based elastic body,
Preferably it is selected in the range of 0.05 to 2 parts by mass.

On the other hand, in the case of the electronic conductive agent, the rubber elastic body 10
1 to 50 parts by mass, preferably 5 to 4 parts by mass with respect to 0 parts by mass.
It is selected in the range of 0 parts by mass. Note that, in addition to the conductive agent, other rubber additives such as a known filler and a crosslinking agent can be appropriately added to the conductive elastic layer as needed.

In the present invention, when the conductive foamed elastic body of the toner supply roller (5) is formed of a polyurethane foam, the polyurethane foam is so formed that precipitates on the roller surface do not fuse the toner. Since the acetone extraction rate of the foam is preferably 5% by weight or less, it is necessary to sufficiently examine the amount of the conductive agent to be added. That is, if a large amount of carbon black (for example, channel black) having a large amount of volatilization is blended, the acetone extraction ratio is increased, and if a carbon black having a large oil absorption (for example, acetylene black or high-structure oil furnace black) is blended, the acetone extraction ratio is increased. Can be reduced.

Developing roller used in the developing device of the present invention
(6) is conductive, and has a conductive elastic layer formed on the outside of a good conductive shaft, similarly to the one usually used as a conventional conductive developing roller. For the conductive elastic layer, an elastic material obtained by adding a conductive agent to an appropriate rubber-like elastic body to impart conductivity is used.

There is no particular limitation on the rubber-like elastic body.
It can be arbitrarily selected from those conventionally used in conductive developing rollers. Examples of the rubbery elastic body include nitrile rubber, ethylene propylene rubber, ethylene propylene diene rubber, styrene butadiene rubber, butadiene rubber, isoprene rubber, natural rubber, silicone rubber, urethane rubber, acrylic rubber, chloroprene rubber, butyl rubber, and epichlorohydrin rubber. And the like. These may be used alone or in combination of two or more. Among them, nitrile rubber, urethane rubber, epichlorohydrin rubber, ethylene propylene rubber, ethylene propylene diene rubber, and silicone rubber are particularly preferable.

On the surface of the developing roller (6), a resin having a thickness of 1 to 100 μm made of a crosslinkable resin such as an alkyd resin, a phenol resin, a melamine resin and a mixture thereof for preventing contamination of the photoreceptor. It is preferable to provide a coating layer. Various additives such as a charge control agent, a lubricant, a conductive agent, and other resins can be contained in these crosslinkable resins, if desired.

The resin coating layer is usually formed by dissolving or dispersing a cross-linkable resin, a cross-linking agent and various additives (an alcohol-based solution such as methanol or a ketone-based solvent such as methyl ethyl ketone as a solvent). ) Is applied to the elastic layer by a dipping method, a roll coater method, a doctor blade method, a spray method or the like, and then dried at room temperature or at a temperature of about 50 to 170 ° C. to form a crosslinking effect.

[Examples] The present invention will be described in more detail with reference to the following examples.
It is not limited to this embodiment.

Examples 1 to 3 and Comparative Examples 1 to 5 A developing roller A and toner supply rollers B, C, D, E, F, G, H, I, J, K or L were added to the printer shown in FIG. And a constant temperature / humidity (25 ° C / 50%
(RH) An image was formed in an environment, and the image quality of the image was evaluated.

The developing roller A used here was manufactured by the following method. Polyetherpolyol having a molecular weight of 5,000 by adding propylene oxide and ethylene oxide to glycerin (OH value: 33 mg KOH / g)
100 parts (parts by mass, the same applies hereinafter), 1,4-butanediol 1.0 part, nickel acetylacetonate 0.5 part,
0.01 part of dibutyltin dilaurate and 0.005 part of sodium perchlorate were added and mixed using a mixer to prepare a polyol composition. After stirring and defoaming the polyol composition under reduced pressure, 17.5 parts of urethane-modified MDI (diphenylmethane diisocyanate) was added and 2
Stirred for minutes.

Next, the metal shaft was previously set to 110
The mixture was poured into a mold heated to 110 ° C. and cured at 110 ° C. for 2 hours to form a conductive elastic layer on the outer periphery of the metal shaft to obtain a roller. The surface of the obtained roller is polished, and the surface is
S 10 point average roughness was adjusted to 4.0 μmRz.

Next, as a resin for forming the resin coating layer,
Oil-free alkyd resin (Dainippon Ink Co., Ltd., M6
402) and a melamine resin (Super Beckamine L-145-60, manufactured by Dainippon Ink and Chemicals, solid content 60% by mass)
Was used, an oil-free alkyd resin and a melamine resin were mixed with methyl ethyl ketone as a solvent so as to have a solid content mass ratio of 80/20, and the solid content concentration was adjusted to 20 mass%.

With respect to 100 parts by mass of the solid content of this mixture,
20 parts by mass (20 phr) of Printex L6 carbon manufactured by Degussa, Inc., and an average particle diameter of 18 nm were mixed and dispersed using a paint shaker to prepare a coating liquid.

The roller was immersed in the coating solution, pulled up, and heated at 130 ° C. for 3 hours to produce a developing roller A having a cured resin film layer.

The toner supply rollers B, C,
D, E, F, G, H, I, J, K, and L were prepared by preparing a polyol prepolymer as a main raw material by the method described below.

15% by mass of ethylene oxide in glycerin
Molecular weight of 50 with addition of propylene oxide and 85% by mass of propylene oxide
A polymer polyol having a solid content of about 28% (hereinafter referred to as polyol X) using a polyether polyol having a base weight of 00 as a base polyol, and a hydrophilicity having a molecular weight of 3400 obtained by adding 75% by mass of ethylene oxide and 25% by mass of propylene oxide to glycerin. Polyether polyol
(Hereinafter referred to as polyol Y) and polyether polyol having a molecular weight of 4800 obtained by adding 15% by mass of ethylene oxide and 85% by mass of propylene oxide to glycerin.
(Hereinafter, referred to as polyol Z) in a total mass of 90 g, and 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate were mixed with 20 g of a mixture having a mass ratio of 8: 2, After thoroughly stirring,
The temperature was kept at 60 ° C. and the stirring was repeated every 12 hours.
After an hour, a prepolymer of polyether polyol was obtained.

To 110 g of this prepolymer, 20 g of water,
0.1 g of tetramethylethylenediamine (amine catalyst),
2.5 g of a silicone foam stabilizer having a hydroxyl group introduced into a terminal was mixed.

This mixture was subjected to sulfur free-cutting, which had a number of minute depressions on the inner surface of the cylinder, was coated with Teflon (registered trademark) on the surface, was closed with a removable lid at the end, and was centered on the axis. 0.9 times to 1. 1 times the specified amount (a value corresponding to the volume of the mold, and the standard specified amount is 1) in a cylindrical mold provided with a galvanized shaft on a rope.
Adjust the injection amount in the range of 5 times, inject, close the mold lid,
It was left in a hot-air oven adjusted to 0 ° C. for 8 to 10 hours to obtain a toner supply roller (5) made of foamed and cured polyurethane foams of various hardnesses.

Also, as the cylinder, one prepared by changing the size (diameter), depth, and number of the minute dents formed on the inner surface thereof is prepared, and the occupation area ratio of the minute projections (12a) on the outermost layer surface is different. , Toner supply rollers B, C, D, E, F, G, H,
I, J, K and L were obtained. Regarding the toner supply roller E, the surface of the toner supply roller B manufactured was slightly polished to eliminate irregularities to form an opening. Regarding the toner supply roller L, the surface of the roller prepared as the toner supply roller B was coated with a silicone-based paint to reduce the surface friction resistance.

Table 1 shows the contents of the 11 kinds of toner supply rollers B, C, D, E, F, G, H, I, J, K and L produced as described above. The surfaces of the produced toner supply rollers B, C, D, E, F, G, H, I, J, K, and L are not open, and the toner supply roller E is open. Using a CCD video camera manufactured by Hilux Co., Ltd.
It was confirmed at a magnification of 0 times.

In the example, the compression spring constant of the foamed elastic roller was measured in the circumferential direction of the roller and in the longitudinal direction of the roller by the measuring method shown in FIG. As shown in FIG. 4, the shaft (11) of the toner supply roller (5) is
(13) is fixed horizontally, the force gauge (14) installed on the foamed elastic layer (12) upper part at a constant speed downward (0.1mm
/ Sec), and a disc-shaped compression jig (disc indenter) with a diameter of 13 mm provided at the tip of the force gauge (14) (15)
To a depth of about 1.5 mm, and a method of calculating a spring constant from a measured stress-strain curve.
The measurement was performed at an interval of 30 mm in the longitudinal direction of the roller and at an interval of 30 degrees in the circumferential direction of the roller.

In the examples, the surface frictional resistance of the rollers was measured using a friction tester “HEIDON Tribogear” manufactured by Shinto Kagaku Co., Ltd. in accordance with the method shown in FIG.
As shown in FIG. 5, the toner supply roller (5) was fixed to the movable stage (16) and moved in the direction of the arrow at a friction speed of 100 mm / min. A mating member of friction was an acrylic round bar (17) having a diameter of 12 mm, which was arranged in a direction perpendicular to the toner supply roller (5), and rubbed with a weight (19) of 0.1N. The frictional resistance at this time was measured with a load cell (18). The frictional resistance coefficient is represented by a value obtained by dividing the measured frictional resistance by the applied load.

The acrylic material was selected as the friction partner because the main component of the toner is similar to the acrylic material, and this combination simulates the friction between the toner supply roller and the toner.

The toner supply roller (5) used in the embodiment is
After measuring the compression spring constant by the method shown in FIG. 4 and measuring the frictional resistance by the method shown in FIG. 5, the toner supply roller of the printer shown in FIG.
An image forming test was performed with the arrangement as (5). Also,
The developing roller A was disposed as the developing roller (6).

In the image evaluation and the image formation test, A4 size paper is fed in the vertical direction, and the temperature and humidity (25 ° C.
% RH) environment. The image evaluation was performed by printing a dark gray solid image.

Table 1 shows the results. In Table 1, the image quality was evaluated by printing 100 sheets of a dark gray solid image, and when the image quality of the 100th sheet image was uniform and good, (O), and when the image was uneven due to uneven density, etc., (X). .

[0061]

[Table 1]

[0062]

According to the present invention, the following effects can be obtained. According to the first aspect of the present invention, since the open cells in the foamed elastic body layer do not communicate with the outer peripheral surface, the toner intrudes into the inside and hinders the conveyance of the toner, or the toner intruding into the inside is clogged, Prevents the hardness of the foamed elastic layer from locally changing and preventing the toner supply from becoming non-uniform, allowing the toner to be supplied evenly, and as a result, a beautiful image free from pitch and density unevenness. Obtainable. Further, the minute projections allow the toner to be constantly and uniformly supplied by a constant amount.

According to the second and third aspects of the present invention, the foam elastic layer rotates while being compressed by the developing roller, so that the toner that has entered between the two rollers is gradually discharged toward the outside in the axial direction of the two rollers. In addition, it is possible to correct the tendency of the central portion to be short of toner, and to make toner supply uniform.

According to the fourth to seventh aspects of the present invention, the required amount of toner can be reliably supplied without excess or shortage, and can be uniformly supplied without damaging the toner.

Further, the coefficient of frictional resistance of the outermost layer surface of the foamed elastic material layer and the hardness of the foamed elastic material layer become appropriate, so that the toner supply roller can be pressed well against the developing roller and the frictional property can be improved. Since toner conveyance, toner charging, and toner scraping performed between the developing rollers are suitably performed, a good image free from defects such as uneven pitch and uneven density can be formed for a long period of time.

According to the eighth and ninth aspects of the present invention, it is possible to provide a developing device and an image forming apparatus capable of reliably obtaining a good image over a long period of time.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional front view of a developing device of a laser printer including a toner supply roller of the present invention.

FIG. 2 is a schematic perspective view of one embodiment of a toner supply roller of the present invention.

FIG. 3 is an enlarged longitudinal sectional view of a surface portion of a foamed elastic layer in the toner supply roller of FIG. 2;

FIG. 4 is a schematic diagram showing a method for measuring a compression spring constant of the toner supply roller shown in the embodiment.

FIG. 5 is a schematic diagram illustrating a method for measuring the frictional resistance of the toner supply roller shown in the example.

[Description of Signs] (1) Photoconductor (2) Primary charger (3) LED array printhead (4) Toner cartridge (5) Toner supply roller (6) Developing roller (7) Paper magazine (8) Transfer charging (9) Thermal fixing unit (10) Cleaning unit (11) Shaft (12) Foam elastic layer (12a) Micro projection (13) V block (14) Force gauge (15) Compression jig (disk indenter) ( 16) Movable stage (17) Acrylic round bar (18) Load cell (19) Weight

Claims (9)

[Claims] 1. A toner supply roller that contacts a developing roller that forms a visible image by conveying toner carried on the surface to an image forming body and supplies toner to the developing roller, wherein a shaft serving as a core is provided. And, the shaft was formed in a cylindrical shape on the outer peripheral surface, and had continuous cells inside, and on the outer peripheral surface, the air bubbles were sealed so as not to communicate with the outside, and a number of minute projections were formed. A toner supply roller comprising a foamed elastic body layer. 2. The toner supply roller according to claim 1, wherein the height of the fine projections is higher at the center of the surface of the outermost layer of the foamed elastic material layer. 3. The toner supply according to claim 1, wherein at least one of the number density of the fine projections and the cross-sectional area of the base is smaller at the center of the surface of the outermost layer of the foamed elastic material layer. roller. 4. The method according to claim 1, wherein the size equivalent to the diameter of the base of the microprojection is 3 mm or less (excluding 0 mm) and the height is 1 mm or less (excluding 0 mm). The toner supply roller as described in the above. 5. The occupied area ratio of the fine projections to the surface area of the outermost layer surface of the foamed elastic body is 60% or less (excluding 0%).
The toner supply roller according to claim 2, wherein: 6. The friction resistance coefficient of the outermost layer surface of the foamed elastic material layer is set to 0.4 to 3.0.
6. The toner supply roller according to any one of 5. 7. The compression spring constant of the foamed elastic body layer is 0.2.
5. The pressure of 5 to 5.0 N / mm.
7. The toner supply roller according to any one of 6. 8. A developing device equipped with the toner supply roller according to claim 1. 9. An image forming apparatus equipped with the developing device according to claim 8.