JP3112629B2 - Image forming apparatus and one-component non-magnetic toner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus which uses a one-component non-magnetic toner for development and forms an image by an electrophotographic method, and a one-component non-magnetic toner .

[0002]

2. Description of the Related Art An image forming apparatus of this type using a one-component non-magnetic toner for development is disclosed, for example, in JP-A-4-152.
As described in JP-A-354-354, carbon black or a dye,
A mixture of a coloring agent such as a pigment, a charge controlling agent such as a metal dye or a surfactant, and a wax for controlling the adhesion to a fixing roll or the like is used as a base material, and silica or the like is externally added as a fluidity improving agent. This is generally used as a toner.

However, depending on the amount of silica externally added, sufficient fluidity and transportability cannot always be obtained, and the developing characteristics deteriorate over time to impair the image quality, or the silica floats from the surface of the toner base to cause the developer to fail. Is scattered, and further affects the charging characteristics of the toner, thereby deteriorating the charging characteristics.

For this reason, in this publication, the external addition amount and particle size of silica are specified so that the fluidity and transportability of the developer can be stably maintained.

In Japanese Patent Application Laid-Open Nos. 64-10269 and 2-151872, two types of fine particles having different particle diameters are externally added to a toner base in a one-component non-magnetic developer. Is described as being improved.

According to these publications, inorganic fine particles having a particle diameter of less than 10 nm are externally added to a toner base in order to cope with image unevenness, bleeding, fogging and the like due to insufficient charging or uneven charging of the toner. Thereby, high triboelectric charging performance and fluidity are obtained, and image unevenness, bleeding, fogging and the like are improved.

On the other hand, when the chargeability of the toner is increased, the adhesion between the photosensitive drum and the toner particles is increased, and the transferability is reduced. Therefore, by further externally adding inorganic fine particles having a particle diameter of less than 30 nm and twice or more the particle diameter of the small particles, the inorganic fine particles serve as a spacer and enhance the transfer efficiency.

Further, Japanese Patent Application Laid-Open No. 4-34566 discloses a contact charging / cleanerless type image forming apparatus using a one-component non-magnetic toner. In this method, the photosensitive member is uniformly charged using a charging brush, and the residual toner remaining on the photosensitive member after the transfer is collected by a developing roller of a developing device.

Japanese Patent Application Laid-Open No. 5-188637 discloses a cleaner-less image forming apparatus of a one-component non-magnetic developing type using a spherical toner produced by a polymerization method. This publication describes that a clear image free from fogging, dust, unevenness, and free of a ghost image can be obtained by using a spherical toner. That is, the toner produced by the polymerization method is spherical and homogeneous in shape,
The spread of the particle size distribution is also small, the spread of the charge amount distribution is smaller than that of the irregular toner manufactured by the pulverization method, and the developing roller and the toner layer regulating blade that regulates the thickness of the toner layer attached to the developing roller are provided. The generation of fine powder toner due to the pressure of the toner and the collision of the toner particles can be suppressed to a small amount because the toner particles are spherical, so that a stable image quality can be obtained.

[0010]

In the case of developing using a one-component non-magnetic toner, a method of regulating the thickness of a toner layer on a toner holding member (developing roller), a method of replenishing toner,
In addition, the development characteristics due to the charging ability and fluidity of the toner vary depending on the toner shape, the method of handling the transfer residual toner, the charging method of the photoconductor, and the like. There were no specified blending of externally added fine particles or the definition of the particle diameter.

Further, in Japanese Patent Application Laid-Open No. 4-34666, since there is no cleaner, paper components and paper components adhering to the photoreceptor during the transfer process, such as filler (talc: hydrous magnesium silicate, calcite: calcium carbonate, Kaolin:
Hydrated aluminum silicate, etc.) is collected in the developing device in the developing step. For this reason, for example, when a sheet containing a large amount of talc is used as a transfer medium, in a high-temperature and high-humidity environment (for example, 30 ° C. and 85% RH), the talc is used as a nucleus at the nip portion between the developing roller and the toner layer regulating blade. Agglomeration occurs. As a result, the formation of the toner layer on the developing roller becomes defective, the toner charging becomes insufficient, and the oppositely charged toner adheres to the unexposed portion. As a result, a fogging phenomenon occurs in which a white background portion on the paper becomes black. Further, the amount of toner adhered to the developing roller per unit area, that is, the amount of toner transported decreases. As a result, blurring of printing occurs.

Further, in the case where toner is replenished in order to extend the life of the developing device, a large amount of toner having an average particle size is used in the particle size distribution of the toner, and the toner is pulverized due to collision between the toners. Therefore, as the number of printed sheets increases, the toner charge amount distribution in the developing device changes.

For example, FIG. 7 shows the distribution of the charge amount of the toner by using a charge amount distribution measuring device (E-SPAR manufactured by Hosokawa Micron).
T alyzer), graph a shows the toner charge amount distribution in the initial state, graph b shows the toner charge amount distribution immediately before toner replenishment, and graph c shows the toner charge amount distribution immediately after toner replenishment. I have. That is,
When the toner is consumed and the amount of toner decreases compared to the initial state, the charge amount distribution of the negatively charged toner is shifted toward the positive side, that is, the oppositely charged side, and the number of positively charged oppositely charged toners also increases. .

When new toner is replenished, immediately after replenishment, toner having a higher charge amount (a larger negative value) than in the initial state is generated. This is because the positively charged toner (reversely charged toner) and the negatively charged toner are aggregated by electrostatic force, temporarily deteriorating the fluidity of the toner, and deteriorating the toner slip at the nip portion between the toner layer regulating blade and the developing roller. Therefore, it is considered that the charge amount of the toner due to friction has increased.

Such electrostatic agglomeration of toner grows into a larger toner agglomeration at the nip portion between the toner layer regulating blade and the developing roller, causing the formation of a toner layer to be defective and causing uneven density in a transferred image.

Further, toner agglomeration grows, and a part of the toner is melted to become a complete solid, and adheres to the toner layer regulating blade. When the toner adhered matter is rubbed against the developing roller with a large pressure, the toner component is filmed on the developing roller, and the portion where the filming is performed becomes insufficiently charged and the vertical black streaks appear on the transferred image. Occurs.

In Japanese Patent Application Laid-Open No. 4-152354, when silica externally added to the toner is liberated, the silica easily adheres to the photosensitive drum. Then, the attached silica is further attached to the charging brush.

Further, in the case of contact charging and cleanerless as disclosed in JP-A-4-34566, when the transfer residual toner passes through the charging brush or when the transfer residual toner adheres to the charging brush. Then, the silica is released from the toner and adheres to the charging brush. If silica adheres to the charging brush, the charging performance of the charging brush is reduced because the silica is an insulator, which causes poor charging. Then, vertical black streaks are generated on the transferred image due to poor charging.

In a contact charging type image forming apparatus equipped with a cleaner, silica is not sufficiently removed by the cleaner because the particle diameter is considerably smaller than that of the toner and has good fluidity. Adhesion also causes poor charging, and a vertical black streak appears on the transferred image as in the case of cleanerless.

Further, in a cleaner-less type image forming apparatus of a one-component non-magnetic developing type using a spherical toner produced by a polymerization method as disclosed in JP-A-5-188637, since the toner is spherical, pressure is applied to the toner. When hexagons are added, hexagonal closest packing becomes easy. At this time, the fluidity of the toner is small, and the toner is easily condensed. Therefore, toner agglomeration occurs in a nip portion between the developing roller and the toner layer regulating blade, and the thickness of the toner layer on the developing roller becomes uneven, which adversely affects a transferred image.

According to a first aspect of the present invention, development is performed using a one-component non-magnetic toner, and a toner layer thickness regulating member is pressed against the surface of the toner carrier to regulate the toner layer thickness on the toner carrier. By using fluidized fine particles as external particles to be added to the toner, and by optimizing the average particle diameter, specific gravity, and blending amount of the fluidized fine particles of the toner and the fluidized fine particles, the image density, the photoreceptor fog, and the transfer Provided is an image forming apparatus that can keep the remainder in a good state, prevent filming of the toner holding member even when toner is supplied, and prevent the toner from aggregating, and always realize good image formation. I do.

According to a second aspect of the present invention, development is performed using a one-component non-magnetic toner, and a toner layer thickness regulating member is pressed against the surface of the toner carrier to regulate the toner layer thickness on the toner carrier. Further, in the apparatus in which the transfer residual toner is collected and reused in the developing means, fluidized fine particles and second fine particles are used as fine particles externally added to the toner, and the average of the toner, the fluidized fine particles, and the second fine particles is used. By optimizing the particle size, specific gravity, and the blending amount of the fluidized fine particles and the second fine particles, the image density, the photoreceptor fog, and the transfer residue can be maintained in a good state. It can prevent filming of the body and aggregation of the toner,
Further, the present invention provides an image forming apparatus capable of preventing toner from aggregating due to paper components such as talc mixed in during toner recovery, and always realizing good image formation.

According to a third aspect of the present invention, development is performed using a one-component non-magnetic toner, and a toner layer thickness regulating member is pressed against the surface of the toner carrier to regulate the toner layer thickness on the toner carrier. Further, when the surface of the electrostatic latent image holding member is uniformly charged by contact charging, fluidized fine particles and second fine particles are used as fine particles externally added to the toner, and the average of the toner, the fluidized fine particles, and the second fine particles is used. By optimizing the particle size, specific gravity, and the blending amount of the fluidized fine particles and the second fine particles, the image density, the photoreceptor fog, and the transfer residue can be maintained in a good state. It can prevent filming of the body and aggregation of the toner,
Further, the present invention provides an image forming apparatus capable of preventing the externally added fine particles from being separated and adhering to the contact charging means, and always realizing good image formation.

According to a fourth aspect of the present invention, there is provided an image density, photoreceptor
Fog and transfer residue can be maintained in good condition, and replenishment
To prevent filming and aggregation.
The present invention provides a one-component non-magnetic toner which can be stopped .

[0025]

The invention corresponding to claim 1 is:
An electrostatic latent image holding member for holding an electrostatic latent image; charging means for uniformly charging the surface of the electrostatic latent image holding member; and a part of the charge on the electrostatic latent image holding surface charged by the charging means. Means for attenuating to form an electrostatic latent image, developing means for adhering toner to the electrostatic latent image formed by this means and developing to form a toner image, and a toner image formed by this developing means. Transfer means for transferring the toner image onto a transfer medium; developing means for supplying toner to the surface of the electrostatic latent image holding member; and a toner layer for pressing against the surface of the toner holding member and supplying the toner to the surface of the electrostatic latent image holding member In an image forming apparatus provided with a toner layer thickness regulating member for regulating the thickness, a one-component non-magnetic toner is used as the toner supplied from the developing means to the surface of the electrostatic latent image holding member, and the toner base of the toner is formed into a spherical shape. flow as fine particles externally added to the toner base When using microparticles, the average particle diameter of the toner base D1, the specific gravity and .rho.1, an average particle size of the fluidizing particles D2, a specific gravity [rho] 2, the weight percent of the amount was Y2, 1.21 <Y2 / 100 · ρ1 / ρ2 · D1 / D2
≤ 3.63 so that D1, D2, ρ1, ρ
2 and Y2 are set in the image forming apparatus .

According to a second aspect of the present invention, there is provided an electrostatic latent image holding member for holding an electrostatic latent image, charging means for uniformly charging the surface of the electrostatic latent image holding member, and a static electricity charged by the charging means. Means for forming an electrostatic latent image by attenuating a part of the charge on the surface of the electrostatic latent image holding member, and developing means for forming a toner image by applying toner to the electrostatic latent image formed by this means and developing the electrostatic latent image A transfer unit for transferring the toner image formed by the developing unit to a transfer medium, wherein the developing unit is in contact with a toner holding member that supplies toner to the surface of the electrostatic latent image holding member, and is in pressure contact with the surface of the toner holding member. In an image forming apparatus provided with a toner layer thickness regulating member for regulating the thickness of a toner layer supplied to the surface of an electrostatic latent image holding member, and collecting and reusing the transfer residual toner in the developing unit, the electrostatic latent image is transferred from the developing unit. One-component non-magnetic toner as toner to be supplied to the holder Use, the toner base of the toner
And spherical using a fluidized particulates and large second fine particles having an average particle diameter than the fluidized fine particles as fine particles externally added to the toner base, an average particle size of the toner base D1,
The specific gravity is ρ1, the average particle size of the fluidized fine particles is D2, the specific gravity is ρ2, the weight% of the added amount is Y2, the average particle size of the second fine particles is D3, the specific gravity is ρ3, and the weight% of the added amount is Y3. 1.21 <Y2 / 100 · ρ1 / ρ2 · D1 /
D2 ≦ 3.63 and D2 <D3 <0.155 · D1 and 1 <Y3 / 100 · ρ1 / ρ3 · (D1 / D3) ³ ≦
3, so that D1, D2, D3, ρ1, ρ2
, [Rho] 3, Y2, the image forming apparatus sets the value of Y3 Oh <br/> Ru.

According to a third aspect of the present invention, an electrostatic latent image holding member for holding an electrostatic latent image, and the electrostatic latent image holding member are disposed in contact with the surface of the electrostatic latent image holding member so that the surface of the electrostatic latent image holding member is uniformly formed. Contact charging means for charging, means for attenuating a part of the charge on the surface of the electrostatic latent image holding member charged by the contact charging means to form an electrostatic latent image, and The image forming apparatus includes a developing unit that forms a toner image by performing development by attaching toner, and a transfer unit that transfers the toner image formed by the developing unit to a transfer medium. The developing unit applies the toner to the surface of the electrostatic latent image holding member. In an image forming apparatus provided with a toner holding member to be supplied and a toner layer thickness regulating member that presses against the surface of the toner holding member and regulates a toner layer thickness to be supplied to the surface of the electrostatic latent image holding member, an electrostatic latent image is formed from a developing unit. Use one-component non-magnetic toner as the toner to be supplied to the image carrier surface. And, spherical toner base of the toner
The fluidized fine particles and the second fine particles having an average particle diameter larger than that of the fluidized fine particles are externally added to the toner base .
The average particle size of the toner matrix is D1, the specific gravity is ρ1, the average particle size of the fluidized fine particles is D2, and the specific gravity is ρ.
2, when the weight% of the added amount is Y2, the average particle size of the second fine particles is D3, the specific gravity is ρ3, and the weight% of the added amount is Y3, 1.21 <Y2 / 100 · ρ1 / ρ2 · D1 / D2
≤3.63 and D2 <D3 <0.155 · D1 and 1 <
D1, D2, D3, ρ1, ρ2, ρ3 so as to satisfy Y3 / 100 · ρ1 / ρ3 · (D1 / D3) ³ ≦ 3.
, Y2, Y3 in the image forming apparatus .

According to a fourth aspect of the present invention, a spherical toner base is provided.
The fluidized fine particles are externally added, and the average particle size of the spherical toner matrix
Is the average particle diameter of the fluidized fine particles, where D1 is the specific gravity and ρ1 is the specific gravity.
Is D2, specific gravity is ρ2, and weight% of the added amount is Y2.
Come, 1.21 <Y2 / 100 · ρ1 / ρ2 · D1 / D2 ≦
The values of D1, D2, ρ1, ρ2, and Y2 are set so as to satisfy 3.63.
Is set in the one-component non-magnetic toner.

[0029]

The invention corresponding to claim 1 will be described.

First, the minimum adhered amount of the fluidized fine particles will be described. The minimum adhered amount of the fluidized fine particles is the minimum amount at which the toners do not directly contact each other. As shown in FIGS. 1A and 1B, the hexagonal closest packing removes a minimum number of particles so that the particles do not come into contact with each other.

If the particles are slightly denser than this state, as shown in FIG. 2A, the fluidized fine particles B come into contact with each other and repel, so that the toner layer thickness regulating member and the toner holding member are repelled. The fluidity of the toner matrix A is ensured even under the pressure at the contact portion with the toner.

If the particles are slightly coarser than this state, as shown in FIG. 2B, the toner matrix A and the fluidized fine particles B are in contact with the toner layer thickness regulating member and the toner holder. , The fluidized fine particles t and the toner base A contact each other, and toner aggregation is likely to occur.

Accordingly, the toner matrix A in the state of FIG.
Assuming that the coverage of the fluidized fine particles B on the surface is γmin,

(Equation 1)

## EQU1 ##

Next, the maximum adhesion amount of the fluidized fine particles will be described.

The state of adhesion of the fluidized fine particles B at the maximum amount of adhesion is hexagonal close packing as shown in FIG. In a state where the particles are slightly denser than this state, the fluidized fine particles B adhere to the toner base A in two or more stages, and FIG.
(B). At this time, since the fluidized fine particles B are in contact with each other, the fluidized fine particles B that are not in direct contact with the toner matrix A receive pressure at a contact portion between the toner layer thickness regulating member and the toner holding member, and collide with each other.
Due to the friction, the toner is easily released from the toner matrix A.

Accordingly, when the coverage of the fluidized fine particles B on the surface of the toner matrix A in the state of FIG.

(Equation 2)

## EQU4 ##

Next, the weight ratio of the fluidized fine particles will be described.

First, the number of adhered fluidized fine particles B is determined as n2. Assuming that the surface area of the toner base A is S1, the projected area of the fluidized fine particles B is S2, and the coverage of the fluidized fine particles B on the surface of the toner base A is γ, γ · S1 =
The relationship of n2.S2 is established. Therefore, the toner matrix A
And when regarded as a sphere fluidization particles B, n2 = S1 / S2 · γ = 4π (D1 / 2) 2 / π (D2 / 2) 2 · γ = 4 (D1 / D2) 2 · γ ... ( 3)

Here, D 1 is the average particle size of the toner matrix A,
D2 is the average particle size of the fluidized fine particles B. The relationship of the above formula (3) is established when the particle size of the fluidized fine particles B is sufficiently smaller than the particle size of the toner base A, and D1 / D2> 1.
00 is desirable.

Next, assuming that the specific gravity of the toner base A is ρ1 and the specific gravity of the fluidized fine particles B is ρ2, the total weight of the toner base A is M
1, the total weight of the fluidized fine particles B is M2, and the total number of toners is α.
Then, M2 / M1 = [ρ2 · 4π / 3 · (D2 / 2) ³ · n2 · α] / [ρ1 · 4π / 3 · (D1 / 2) ³ · α] = ρ2 / ρ1 · (D2 // D1) ³ · n2 (4) Here, from the above equations (3) and (4), M2 / M1 = ρ2 / ρ1 · D2 / D1 · 4γ (5) Assuming that the weight percentage of the fluidized fine particles B with respect to the total toner is Y2, Y2 = M2 / (M1 + M2) .100. However, since M1 / M2 is in the range of about 100, Y2 = M2 / M1. 100 ... (6).

Therefore, from the above equations (5) and (6), 4γ = Y2 / 1001ρ1 / ρ2 ・ D1 / D2, so that Y2 falls within the range satisfying the above equations (1) and (2). Γmin <Y2 / 100 · ρ1 / ρ2 · D1 / D2 ≦
4 · γmax, and the values of γmin and γmax are substituted into the result: 1.21 <Y2 / 100 · ρ1 / ρ2 · D1 / D2 ≦ 3.63 (7) According to the equation (7), the average particle diameter D1 and specific gravity ρ1 of the one-component non-magnetic toner, the average particle diameter D2 and specific gravity ρ2 of the fluidized fine particles, and the addition amount Y2 can be appropriately set.

Next, the invention corresponding to claim 2 will be described.

In the present invention, second fine particles having a larger particle diameter than the fluidized fine particles are externally added to the toner together with the fluidized fine particles.

In the case where a stronger pressing force is generated in the pressure-restricted portion between the toner layer thickness regulating member and the toner holding member, or in the case where stronger aggregation occurs with respect to the toner due to a paper component such as talc, fluidization is performed. Due to the embedding of the fine particles in the toner matrix, the fluidity cannot be ensured even if the fluidized fine particles are properly added, and toner aggregation occurs. In some cases, the resin component of the toner matrix is melted to cause the toner to adhere.

In such a case, aggregation of the toner is prevented by attaching the second fine particles to the toner matrix.

Regarding the minimum amount of the second fine particles, since the fluidized fine particles have already adhered to the surface of the toner base, the second fine particles are placed on or between the fluidized fine particles. Existing. In order to serve as a cushioning material for direct contact between toners, it is necessary that at least one second fine particle exists per toner base.

In terms of the maximum adhesion amount of the second fine particles, the toner moves while receiving pressure between the fixed toner layer thickness regulating member and the toner holder, and the toner moves at the outlet of the toner layer thickness regulating member. Layers are uniformly formed to about three layers. At this time, the toner is arranged in a substantially hexagonal close-packed state.

In this process, the fine particles adhering to the toner matrix serve as a buffer to prevent the toner from aggregating.
If the number of the adhered particles is too large, the second fine particles are released from the toner matrix, and adversely affect toner layer formation and toner charging.

Since the particle size of the second fine particles is larger than that of the fluidized fine particles, it is impossible to apply a planar distribution to the surface of the toner base as in the case of the fluidized fine particles. The placement must be considered.

The toner moves while receiving a strong pressure in the space between the toner layer thickness regulating member and the toner holding member, and is arranged in a hexagonal close-packed state. The rotation and movement of the toner base itself or the movement, separation and reattachment of the second fine particles on the toner base are performed so as to be arranged in the holes formed by the above.

The number and size of pores in hexagonal close packing are described in Shigeo Miwa, Introduction to Powder Engineering, Nikkan Kogyo Shimbun, 1
981, pages 48 to 49 ", there are eight T holes formed from the four toner bases A1 to A4 shown in FIG. 4 (a) around one toner base, that is, one toner base. 2 pieces are formed. Further, six R holes formed from the six toner bases A5 to A9 (note that the front toner base is omitted) shown in FIG. That is, one toner base is formed for each toner base.

The diameter of the largest inscribed circle of the T and R holes is
Assuming that the diameter of the toner matrix is D1, the diameter of the T hole is Dt, and the diameter of the R hole is Dr, Dt = 0.155 D1 and Dr =
0.414D1.

Therefore, the number of fine particles having a size of Dt or less is three per one toner base, that is, T vacancies and R
Up to the total number of holes, the toner can adhere to the toner matrix. If the number is four or more, they cannot be arranged in the T holes and the R holes, so they are repelled and released by the toner or buried in two adjacent toner bases to become a core of toner aggregation. Accordingly, if the average particle diameter of the second fine particles is D3, the condition of D3 is D2 <D3≤0.155D1 (8). Further, as in the above equation (4), assuming that the specific gravity of the second fine particles is ρ3, the total weight is M3, and the number of adhered particles is n3, M3 / M1 = ρ3 / ρ1 (D3 / D1) ³ · n3 (9) ).

Further, assuming that the weight percentage of the second fine particles with respect to the total toner is Y3, there is no problem as Y3 = M3 / M1 · 100 (10) as in the above equation (6). Therefore, the above equations (9) and (10) and condition 1
By ≦ n3 ≦ 3, a 1 ≦ Y3 / 100 · ρ1 / ρ3 · (D1 / D3) 3 ≦ 3 ... (11). Thus, the particle diameter and the amount of addition of the second fine particles can be appropriately set by the expressions (8) and (11).

Next, the invention corresponding to claim 3 will be described.

In the invention according to claim 3, the contact charging means is used as the charging means. In this invention, the second fine particles are externally added, and the conditions of the particle diameter and the amount added are as defined in claim 2. Same as the invention.

[0059]

[0060] If the shape of the mother toner is spherical, before Symbol
There is almost no error between the range of the numerical values defined by the equations (7), (8) and (11) and the actual toner particle diameter and adhesion amount, and the amount of addition to the actual toner can be accurately determined.

[0061]

Embodiments of the present invention will be described below with reference to the drawings. This embodiment will be described as applied to a contact charging / cleanerless type image forming apparatus.

In FIG. 5, reference numeral 11 denotes a photosensitive drum which is an electrostatic latent image holding member. The photosensitive drum 11 is an organic material in which a photoconductive layer made of an organic photoconductive material is formed on the surface of a metal tube such as aluminum. It is a photoconductor.

In the charging step, the photosensitive drum 11 is uniformly negatively charged by a conductive charging brush 12 as a contact charging means. The charging brush 12 is made of conductive rayon having a fiber thickness of 3 denier, a flocking density of 100,000 fibers / cm ² , a fiber length of about 4 to 8 mm, and a resistance value of 10 ⁵ to 10 ⁶ Ωcm. I have.

As the charging brush, a brush obtained by conducting a conductive treatment on polyamide, acrylic, tetrafluoropolyethylene or the like may be used. In this embodiment, a fixed brush is used as the charging brush, but any other brush that vibrates the fixed brush or a brush that rotates the brush roller can be used. In addition to the brushes, rubber roller blades of urethane, NBR, silicone, SBR, EPD and the like, and roller blades of foam material can be used. However, it is required that the conductivity is provided, that the photosensitive drum is not contaminated, and that the toner and the components of the toner are not filmed.

[0065] so as to form an electrostatic latent image was exposed to light beams 13 such as a laser beam by the exposure process on the surface of the charging is uniformly negatively charged by the brush 12 the photosensitive drum 11. That is, the light beam attenuates a part of the charge on the surface of the photosensitive drum 11 based on the image information to form an electrostatic latent image.

The electrostatic latent image thus formed is developed by attaching toner from the developing device 14 in the next developing step.

The developing device 14 accommodates a one-component non-magnetic toner 16 in a toner hopper 15, arranges a developing roller 17 as a toner holding member at an outlet of the toner hopper 15, and supplies toner to the rear of the developing roller 17. Roller 18
Are arranged in contact with the developing roller 17. An agitator 19 is provided at the center of the toner hopper 15.
To stir the toner 16 in the hopper.

On the upper surface of the developing roller 17, a toner layer thickness regulating blade 20, which is a toner layer thickness regulating member, is disposed. The toner layer thickness regulating blade 20 is
1, the tip is pressed against the surface of the developing roller 17.

The developing roller 17 is formed by providing a conductive urethane rubber layer around a metal shaft and further forming a conductive urethane resin layer on the surface thereof.
Resistance value less than 0 ⁵ Ω · m ² , hardness 30 degrees (JISA type)
It has become a roller. The diameter of the developing roller 17 is 1
2 mm, and the thickness of the urethane resin layer is 20 to 50 μm.

In addition, as the developing roller, a roller obtained by dispersing conductive carbon particles or metal fibers in rubber such as silicone rubber, ethylene propylene rubber, NBR, chloroprene rubber, and butyl rubber can be used. Although a rubber surface layer is not always necessary, it may be covered with a silicone resin or a fluorine resin.

The toner layer thickness regulating blade 20 is made of silicone rubber whose tip is machined into a cylindrical, curved or planar shape, and has a rubber hardness of 30 to 100 degrees. The developing roller 1 of the toner layer thickness regulating blade 20
7 is 200 g / cm ^{2 to} 1000 g / cm ^2.
Set to about. This toner layer thickness regulating blade 2
The material 0 may be a rubber material such as urethane rubber or NBR, or a metal material such as stainless steel, phosphor bronze, or aluminum.

The toner supply roller 18 is made of a conductive foam material, and has a resistance value of 10 ³ to 10 ⁶ Ω · cm by adding carbon or a metal filler to urethane.
Note that a blade-shaped roller may be used instead of the toner supply roller.

A toner layer is formed on the surface of the developing roller 20 by a pressing force against the toner layer thickness regulating blade 20, and the toner layer is formed on the developing roller 20 and the photosensitive drum 11.
The toner adheres to the electrostatic latent image formed on the photosensitive drum 11 at a contact portion with the toner image to form a toner image.

This toner image is transferred to a transfer medium, for example, transfer paper 23 supplied by the operation of the scorotron transfer device 22 having a grid in the next transfer step. In addition,
A gridless corotron charger or a conductive roller made of rubber such as urethane, NBR, silicone, EPDM or a foam material may be used as the transfer device.

The one-component non-magnetic toner 16 is prepared by mixing carbon, pigment, and the like in various thermoplastic resins such as styrene resin, acrylic resin, polyester resin, and epoxy resin.
A dispersion of a coloring material such as a dye, a wax such as polyethylene or polypropylene, or a polarity controlling material such as a metal-containing azo dye is used as a toner base.

As a method for producing the toner, there are a pulverization method and a polymerization method. In this embodiment, the toner produced by the polymerization method is used. In order to further enhance the fluidity of the toner, fine particles such as silica, alumina, barium titanate and zinc oxide are externally added to the toner matrix as fluidized fine particles.

The toner matrix used in this example is a spherical toner because it is manufactured by a polymerization method. A toner obtained by dispersing carbon black, a metal-containing azo dye, and polypropylene in a styrene-acrylic resin is used. The particle diameter D1 is 9 μm and the specific gravity ρ1 is about 1.1.

The toner base had an average particle diameter D 2 of 11 n.
m and hydrophobized silica having a specific gravity ρ2 of about 2.3 are used as fluidized fine particles, and alumina silica having an average particle diameter D3 of 1 μm and a specific gravity ρ3 of about 2.2 is externally added as second fine particles. Used as finished toner. The external addition of the fluidized fine particles and the second fine particles was performed simultaneously in this embodiment, but either of them may be performed first.

In the embodiment having such a structure, the photosensitive drum 11 is uniformly negatively charged by the charging brush 12 in the charging step, and is exposed by the light beam 13 in the next exposing step to form an electrostatic latent image. It is formed and is developed in a nip portion with the developing roller 17 in the next developing step. At this time, the toner 16 adheres only to a portion of the surface of the photosensitive drum exposed to the light beam 13 (a portion where a part of the charge is lightly attenuated) by a so-called reversal developing method.

Thus, a toner image is formed on the surface of the photosensitive drum. This toner image is transferred to the transfer paper 23 by the scorotron transfer unit 22 in the next transfer step. In this transfer step, not all of the toner is transferred, and the untransferred toner 16a is distributed imagewise on the surface of the photosensitive drum 11 after the transfer.

The transfer residual toner 16 a is charged to the same polarity as the surface of the photosensitive drum 11 by the charging brush 12 in the next charging step. In the exposure step, as long as the transfer residual toner 16a is not dense, the light beam 13 can expose the surface of the photosensitive drum without being blocked by the transfer residual toner 16a.

In the next developing step, the electric field formed between the photosensitive drum 11 and the developing roller 17 in the exposed portion acts in a direction in which the toner 16 adheres to the photosensitive drum 11. In an unexposed portion, the electric field formed between the photosensitive drum 11 and the developing roller 17 causes the toner to flow through the developing roller 17.
To the transfer residual toner 1
6 a is collected by the developing roller 17.

In this manner, cleaning is performed simultaneously with development in the development process.

In the developing device 14, the toner 16 is stirred by the agitator 19 and supplied to the developing roller 17 by the toner supply roller 18. Further, the toner supply roller 18
Removes the toner 16 remaining on the developing roller 17 without being attached to the photosensitive drum 11 and the transfer residual toner 16 a collected from the photosensitive drum 11 by the rotational friction with the developing roller 17. The toner layer thickness regulating blade 20 is pressed against the developing roller 17 with a predetermined pressure, regulates the thickness of the toner layer supplied to the photosensitive drum 11 to a uniform thin layer, and charges the toner.

With the above operation, the toner image is transferred to the transfer paper 23 to form an image.

The one-component non-magnetic toner 1 used
6, the image evaluation when fluidized fine particles (hydrophobic silica, average particle size D2 = 11 nm) and second fine particles (alumina silica, average particle size D3 = 1 µm) were externally added to the toner base at various weight percentages Are shown in Tables 1 and 2.

K2 and K3 in Tables 1 and 2 are determined as follows. K2 is determined as a value corresponding to the above equation (7), and K2 = Y2 / 100 · ρ1 / ρ2 · D1 / D2 (12) Substituting the values of the particle size and the specific gravity into the above equation (12), K2 = Y2 / 100 × 1.1 / 2.3 × 9.0 / 11 ×
10 ^-3, that is, K2 = 3.9Y2, and 1.21 <3.9.
% By weight of fluidized fine particles so as to satisfy Y2≤3.63
Is determined.

Further, regarding the above-mentioned equation (8), D1 =
9. When D3 = 1 is substituted, 1 <0.155 × 9, that is, 1 <1.395, and the particle diameter of the second fine particles is
Equation (8) is satisfied.

Therefore, as a value corresponding to the equation (11), K3
Is determined as follows, and K3 = Y3 / 100.ρ1 / ρ3 · (D1 / D3) ³ (13) When the values of the particle size and specific gravity are substituted into the above equation (13), K3 = Y3 / 100.times.1.1 / 2.2.times. (9/1) ^3, that is, K3 = 3.6Y3, and 1≤3.6Y3. ≤
Y3, which is the weight percentage of the second fine particles, is determined so as to satisfy 3.

[0090]

[Table 1]

[0091]

[Table 2]

Next, each image evaluation in Tables 1 and 2 will be described. The image density a is a Macbeth reflection densitometer (RD-
920) is a value obtained by measuring a solid black portion on the transfer paper 23.

For the photoreceptor fog, the fog (non-image portion, white background portion) on the photoreceptor drum 11 is transferred to a Scotch mending tape (made of # 810, 3M), affixed to paper, and the reflectance is measured with a colorimeter ( Minolta, CR-221) is simply the value obtained by subtracting the reflectance when a Scotch Mendeg tape is attached to paper. Therefore, as this value is smaller, fogging is less and good image formation can be performed.

For the transfer residue b, black solid printing is performed, the transfer residue toner on the photosensitive drum 11 after the transfer is transferred to a scotch mending tape, affixed to paper, and the reflectance is measured from a value measured by a colorimeter. However, the value is simply a value obtained by subtracting the reflectance when the Scotch Mendeg tape is attached to the paper. Therefore, the smaller the value, the smaller the amount of untransferred toner and the better the transfer.

In the toner layer formation failure c, toner agglomeration occurs in a nip formed by the toner layer thickness regulating blade 20 and the developing roller 17, and the toner layer cannot be made uniform. (Conveying direction). Even when the amount of the released fine particles is too large, the charging of the toner becomes defective and the same phenomenon occurs.

The following ranking is performed in Tables 1 and 2. A: Good toner layer formation, no density unevenness.
B: Slightly defective toner layer formation, uneven density. C: Toner layer formation is slightly poor, density unevenness is slightly present (an acceptable level on an image). D: Poor toner layer formation, uneven density.

In the developing roller filming d, toner agglomeration occurs in a nip portion formed by the toner layer thickness regulating blade 20 and the developing roller 17, and this further develops, and the toner adheres to each other. Is a phenomenon in which toner is filmed in the circumferential direction of the developing roller 17 because the toner is pressed with a strong pressure. This is a phenomenon that occurs when new toner is mixed with old toner when new toner is supplied to the toner hopper 15. Vertical black streaks occur on the image.

In Tables 1 and 2, the following ranking is performed. A: No filming and no image defects.
B: There is a small number of filming and no image defect. C: There is a small number of filming, and a thin black streak is generated (an acceptable level on the image). D: Many filming, black streaks occurred.

Talc paper photoreceptor fog e: When printing is performed using a talc-containing paper as the transfer paper 23 in a high temperature and high humidity environment (30 ° C., 80% RH), the toner layer thickness regulating blade 20 and the developing roller 17 This is a phenomenon in which talc accumulates in the formed nip portion, and the talc acts as a nucleus to cause aggregation of the toner, which adversely affects the fluidity of the toner. When this phenomenon occurs, the chargeability of the toner deteriorates, and the oppositely charged toner is generated, and the non-image area (white area) of the photosensitive drum 11
The oppositely-charged toner adheres to the toner, resulting in fogging. Further, the toner layer may not be formed uniformly, and the printing may be blurred.

In Tables 1 and 2, a binary evaluation was made as to whether or not there was fogging.

Adhesion of charging brush f: Hydrophobic silica or fluidized fine particles externally added to the toner and alumina-silica as the second fine particles are released from the toner matrix, and charged brush 1
2 is a phenomenon that adheres. Since these deposits are insulators, the charging ability of the charging brush 12 is significantly reduced,
For this reason, charging failure occurs, and appears as vertical black streaks on the image.

In Tables 1 and 2, a binary evaluation was performed to determine whether or not black streaks were present.

FIG. 6 is a graph of Tables 1 and 2, wherein the horizontal axis represents the weight percentage of the fluidized fine particles and the vertical axis represents the weight percentage of the second fine particles.
O. 1 to NO. 19 are arranged at the corresponding positions on the graph, and the image density a, the transfer residue b, the toner layer formation failure c, the developing roller filming d, the talc paper photoconductor fog e, and the adhesion f of the charging brush are represented by a square hexagon. Each equally divided piece is represented in three stages. That is, white indicates good,
The diagonal lines indicate slightly good and acceptable levels, and the black indicates poor. In addition, the fogging of the photoreceptor is omitted because all samples have a good value of 1% or less.

Table 3 shows the levels of the three-level evaluations of the image density a, transfer residue b, toner layer formation failure c, developing roller filming d, talc paper photoconductor fog e, and charging brush adhesion f. ing.

[0105]

[Table 3]

In the graph, Y2min, Y2max, Y3min, Y3m
ax indicates the minimum value and the maximum value of Y2 and Y3, respectively, and the above-mentioned expressions (7) and (11), and K2 = 3.9 Y2, K
3 = 3.6Y3, 0.31
(Y2min) <Y2 ≦ 0.93 (Y2max), 0.28 (Y
3min) <Y3 ≦ 0.83 (Y3max).

Results of image evaluation shown in Tables 1 and 2 and FIG. 6 [Effect of second fine particles on talc paper photoconductor fog e] 1, NO. 2 and NO. 11 shows that the talc paper photoconductor fog e occurs, and that the talc paper photoconductor fog e occurs when the addition amount of the second fine particles is 0.28% by weight or less. This indicates that toner aggregation with talc as a nucleus cannot be prevented when the amount of the second fine particles added is small.

Accordingly, in this case, the type of paper used as the transfer paper 23 (for example, paper with a small amount of talc) and the use environment are restricted.

When an image forming apparatus provided with a separate cleaner is used as the image forming apparatus, fillers such as paper dust and talc are removed from the photosensitive drum 11 by cleaning performed by the cleaner after transfer. If the toner is not recycled, the sample NO. 1 and N
O. Good image quality can be obtained even with the second toner.

[Effects of Fluidized Fine Particles and Second Fine Particles on Developing Roller Filming] Developing roller filming d is caused by agglomeration of the toner due to mixing with the oppositely charged toner during toner replenishment. The fluidized fine particles improve the fluidity of the toner and prevent aggregation of the toner.

Sample No. 1 to NO. 8. Sample N
O. 11, NO. 14, NO. 16, NO. As shown in FIG. 17, when the amount of the fluidized fine particles exceeds the minimum amount of 0.31% by weight, filming of the developing roller hardly occurs.

On the other hand, the released second fine particles are likely to become nuclei for toner aggregation. 15, NO.
18, NO. As shown in FIG. 19, when the addition amount of the fluidized fine particles is 0.5%, if the addition amount of the second fine particles exceeds the maximum amount of 0.83% by weight, filming of the developing roller occurs.

Even if the addition amount of the fluidized fine particles is 0.5%, when the toner is replenished little by little to ease the mixing with the oppositely charged toner, the developing roller filming does not occur.

[Effect of Excessive Fluidized Fine Particles and Second Fine Particles on Image] When the added amount of the fluidized fine particles exceeds the maximum value of 0.93% by weight, or when the added amount of the second fine particles is the largest. If the value exceeds 0.83% by weight, the amount of fluidized fine particles or second fine particles released increases. The released fine particles adhere to the surface of the developing roller 17, and as a result, the toner does not come into direct contact with the developing roller 17, which adversely affects the charging of the toner. That is, the sample NO. 1
4, NO. 16, NO. 17, NO. 18, NO. 19
As shown in (1), formation of the toner layer becomes defective. Further, the sample NO. 11, NO. 14, NO. 16, NO. 17
As shown in FIG. 7, the image density also decreases. Further, the sample No. 11, NO. 14, NO. 15, NO. 16, N
O. 17, NO. 18, NO. As shown in FIG. 19, the released fine particles adhere to the charging brush 12 and cause an image defect.

[Case where the amount of fluidized fine particles is very small] 12 is the minimum value of the addition amount of the fluidized fine particles of 0.3.
0.25% which is smaller than 1%. At this time, the formation of the toner layer is insufficient, and the image density is low. This is because the amount of the fluidized fine particles is too small, so that the fluidity is poor and toner aggregation is likely to occur.

Further, in the measurement of the developing roller filming, the charging brush adhesion, and the talc paper photoreceptor fog, the formation of the toner layer deteriorated rapidly, so that it was impossible to print up to a predetermined number of prints required for the measurement, and the evaluation was impossible. Was.

As described above, if the conditions of the addition amount, the particle size, and the specific gravity of the fluidized fine particles and the second fine particles are set so as to satisfy the expressions (7), (8) and (11), the contact charging can be performed. Good image formation can be performed with a cleanerless image forming apparatus.

If the three equations are satisfied, the cleanerless image forming apparatus that performs corona charging also has a cleaner, but returns the toner collected by the cleaner to the toner hopper. In a so-called toner recycling type image forming apparatus, a good image can be formed similarly.

In an image forming apparatus which is not of a toner recycling type and is provided with a corona charging and a cleaner, paper powder and talc do not enter the toner hopper. Good images can be formed by setting the conditions of the amount of added fine particles, the particle size and the specific gravity so as to satisfy the expression (7).

[0120]

According to the first aspect of the present invention, the developing is performed using a one-component non-magnetic toner, and the toner layer thickness regulating member is pressed against the surface of the toner carrier to press the toner layer on the toner carrier. When the thickness is regulated, fluidized fine particles are used as fine particles to be externally added to the toner. Body fogging and transfer residue can be maintained in a good state, and even when toner is supplied, filming of the toner holding member and aggregation of toner can be prevented, and good image formation can be always achieved.

According to the second aspect of the present invention, development is performed using a one-component non-magnetic toner, and the toner layer thickness regulating member is pressed against the surface of the toner holder to reduce the toner layer thickness on the toner holder. In the apparatus for controlling and further recovering and reusing the transfer residual toner in the developing means, fluidized fine particles and second fine particles are used as fine particles externally added to the toner, and the toner, the fluidized fine particles and the second fine particles are used. By optimizing the average particle size, specific gravity, and the amount of fluidized fine particles and the amount of the second fine particles, the image density, the photoreceptor fog, and the transfer residue can be maintained in a good state. Filming of the toner holding member and aggregation of the toner can be prevented, and further, aggregation of the toner can be prevented by a component of paper such as talc that is mixed in when the toner is collected, so that good image formation can always be achieved.

According to the third aspect of the present invention, development is performed using a one-component non-magnetic toner, and the toner layer thickness regulating member is pressed against the surface of the toner holder to reduce the toner layer thickness on the toner holder. In addition, the fluidized fine particles and the second fine particles are used as fine particles to be externally added to the toner, and the toner, the fluidized fine particles, and the second fine particles are used. By optimizing the average particle size, specific gravity, and the amount of fluidized fine particles and the amount of the second fine particles, the image density, the photoreceptor fog, and the transfer residue can be maintained in a good state. Filming of the toner holder and aggregation of the toner can be prevented, and the externally added fine particles can be prevented from releasing and adhering to the contact charging means, so that good image formation can always be achieved.

According to the invention corresponding to claim 4 , the image density,
Photoreceptor fog and transfer residue can be maintained in good condition.
In addition, filming or aggregation may occur even after replenishment.
To provide a one-component non-magnetic toner which can prevent the toner from being damaged.

[Brief description of the drawings]

FIG. 1 is a view for explaining the state of adhesion of fluidized fine particles to the surface of a toner base in the present invention.

FIG. 2 is a view for explaining a minimum adhered state of fluidized fine particles to the surface of a toner base in the present invention.

FIG. 3 is a view for explaining the maximum state of adhesion of fluidized fine particles to the surface of a toner base in the present invention.

FIG. 4 is a view for explaining the number and size of holes in hexagonal close-packing of a toner matrix in the present invention.

FIG. 5 is a schematic configuration diagram showing an embodiment of the present invention.

FIG. 6 shows the weight percent of fluidized fine particles and the second
7 is a graph showing sample examples of various evaluation elements with respect to the weight% of the fine particles.

FIG. 7 is a graph showing the number distribution of charge / particle diameter of toner in an initial state, immediately before toner replenishment, and immediately after toner replenishment in an image forming apparatus of a type in which toner replenishment is performed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Photoreceptor drum (electrostatic latent image holding body) 12 ... Charging brush (contact charging means) 13 ... Light beam (means for forming an electrostatic latent image) 14 ... Developing device 16 ... One component non-magnetic toner 17 ... Development Roller (toner holder) 21: Toner layer thickness regulating blade 22: Scorotron transfer unit 23: Transfer paper

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-7-43934 (JP, A) JP-A-4-152354 (JP, A) JP-A-6-202373 (JP, A) JP-A-2- 284150 (JP, A) JP-A-4-22567 (JP, A) JP-A-3-259161 (JP, A) JP-A-5-188637 (JP, A) JP-A-4-214568 (JP, A) JP-A-4-220664 (JP, A) JP-A-4-225368 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 9/08

Claims (4)

(57) [Claims] An electrostatic latent image holding member for holding an electrostatic latent image;
Charging means for uniformly charging the surface of the electrostatic latent image holding member; means for forming an electrostatic latent image by attenuating a part of the charge on the surface of the electrostatic latent image holding member charged by the charging means; Developing means for forming a toner image by attaching toner to the electrostatic latent image formed by the developing means to form a toner image; and transferring means for transferring the toner image formed by the developing means to a transfer medium. A toner holding member that supplies toner to the surface of the electrostatic latent image holding member, and a toner layer thickness regulating member that presses against the surface of the toner holding member to regulate the thickness of the toner layer to be supplied to the surface of the electrostatic latent image holding member. in the image forming apparatus, using a one-component non-magnetic toner as a toner supplied from the developing unit to the electrostatic latent image holding member surface, bets of the toner
The toner base is spherical, fluidized fine particles are used as fine particles externally added to the toner base , the average particle diameter of the toner base is D1, the specific gravity is ρ1, the average particle diameter of the fluidized fine particles is D2, and the specific gravity is D2. Assuming that ρ2 and the weight% of the added amount are Y2, 1.21 <Y2 / 100 · ρ1 / ρ2 · D1 / D2 ≦
An image forming apparatus wherein the values of D1, D2, ρ1, ρ2, and Y2 are set so as to satisfy 3.63. 2. An electrostatic latent image holder for holding an electrostatic latent image,
Charging means for uniformly charging the surface of the electrostatic latent image holding member; means for forming an electrostatic latent image by attenuating a part of the charge on the surface of the electrostatic latent image holding member charged by the charging means; Developing means for forming a toner image by attaching toner to the electrostatic latent image formed by the developing means to form a toner image; and transferring means for transferring the toner image formed by the developing means to a transfer medium. A toner holding member that supplies toner to the surface of the electrostatic latent image holding member, and a toner layer thickness regulating member that presses against the surface of the toner holding member to regulate the thickness of the toner layer to be supplied to the surface of the electrostatic latent image holding member. And an image forming apparatus for collecting and reusing the transfer residual toner in the developing unit, wherein a one-component non-magnetic toner is used as the toner supplied from the developing unit to the surface of the electrostatic latent image holding member , G
The toner base is spherical, fluidized fine particles and second fine particles having an average particle size larger than the fluidized fine particles are used as fine particles to be externally added to the toner base , and the average particle size of the toner base is D1 and the specific gravity is D1. ρ1, the average particle size of the fluidized fine particles is D2, the specific gravity is ρ2, the weight% of the added amount is Y2, the average particle size of the second fine particles is D3, the specific gravity is ρ3,
Assuming that the weight% of the added amount is Y3, 1.21 <Y2 / 100 · ρ1 / ρ2 · D1 / D2 ≦
3.63 D2 <D3 <0.155.D11 <Y3 / 100.ρ1 / ρ3. (D1 / D3) ³ ≦ 3, so that D1, D2, D3, ρ1, ρ2, ρ
An image forming apparatus wherein values of 3, Y2 and Y3 are set. 3. An electrostatic latent image holder for holding an electrostatic latent image,
A contact charging unit that is arranged in contact with the surface of the electrostatic latent image holding member to uniformly charge the surface of the electrostatic latent image holding member; Means for attenuating a portion to form an electrostatic latent image, developing means for applying a toner to the electrostatic latent image formed by the means to perform development to form a toner image, and toner formed by the developing means Transfer means for transferring an image to a transfer medium, the developing means comprising: a toner holding member for supplying toner to the surface of the electrostatic latent image holding member; and a surface of the electrostatic latent image holding member pressed against the surface of the toner holding member. An image forming apparatus provided with a toner layer thickness regulating member for regulating the thickness of the toner layer supplied to the image forming apparatus, wherein a one-component non-magnetic toner is used as toner supplied from the developing unit to the surface of the electrostatic latent image holding member , G
The toner base is spherical, fluidized fine particles and second fine particles having an average particle size larger than the fluidized fine particles are used as fine particles to be externally added to the toner base , and the average particle size of the toner base is D1 and the specific gravity is D1. ρ1, the average particle size of the fluidized fine particles is D2, the specific gravity is ρ2, the weight% of the added amount is Y2, the average particle size of the second fine particles is D3, the specific gravity is ρ3,
Assuming that the weight% of the added amount is Y3, 1.21 <Y2 / 100 · ρ1 / ρ2 · D1 / D2 ≦
3.63 D2 <D3 <0.155.D11 <Y3 / 100.ρ1 / ρ3. (D1 / D3) ³ ≦ 3, so that D1, D2, D3, ρ1, ρ2, ρ
An image forming apparatus wherein values of 3, Y2 and Y3 are set. 4. External addition of fluidized fine particles to a spherical toner base
And the average particle diameter of the spherical toner mother body D1, the specific gravity ρ1
The average particle diameter of the fluidized fine particles is D2, and the specific gravity is ρ2
1.21 <Y2 / 100 · ρ1 / ρ2 · D1 / D2 ≦ , where Y2 is the weight% of the added amount.
The values of D1, D2, ρ1, ρ2, and Y2 are set so as to satisfy 3.63.
A one-component non-magnetic toner characterized in that: