JPH07160120A - Developing device - Google Patents

Abstract

PURPOSE:To improve the electrostatic chargeability of toner and to improve the quality of an image by fitting the material quality of a toner replenishing member to the material quality of the toner. CONSTITUTION:In the case of using polyester resin-based toner, an NBR rubber roller whose surface is coated with silicone modified EPDM rubber, or a roller which is made of blended rubber of the NBR rubber and the silicone modified EPDM rubber is used as a replenishing roller 35C. Besides, it is preferable to use a roller constituted by coating a core bar with materials with a silicone resin base and combined CCA(electrostatic charging control agent) and carbon black in the case of using polyester resin-based toner, or polyolefine resin-based toner, and the toner layer can be satisfactorily made thin especially in the case of using the polyolefine resin-based toner. And also, the replenishing roller 35C constituted of the silicone modified EPDM rubber can be used for the polyolefine resin-based toner.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device which is used in an image forming apparatus such as a copying machine, a facsimile machine or a printer, and which uses a two-component developer composed of a toner and a carrier. The toner is charged by the toner regulating charging means above, the toner is replenished to the developer carried on the developer carrier, and the latent image on the latent image carrier is visualized by using this developer. The present invention relates to a developing device.

[0002]

2. Description of the Related Art Conventionally, as a developing device of this kind, a toner replenishing roller formed by molding NBR (nitr butadiene) rubber into a roller shape is used as a toner replenishing member, and toner is regulated on the surface of the toner replenishing roller. For example, a metal blade serving as a charging unit is brought into contact with the toner replenishing roller to rotate the toner replenishing roller, thereby forming a thin layer of toner on the toner replenishing roller at the same time and frictionally charging the toner replenishing roller. It is known that a voltage (hereinafter referred to as a replenishing bias) is applied to replenish the toner on the toner replenishing roller to the developer on the developer carrying member (for example, Japanese Patent Laid-Open No. 2-251).
875).

[0003]

By the way, as in the above-mentioned developing device, the toner is preliminarily charged to a predetermined charging potential by a charging roller such as the toner replenishing roller and then replenished to the developer. In the two-component developing device, the charging characteristics of the toner largely change depending on the material of the toner and the material of the charging roller, such as the toner replenishing roller, for charging the toner. That is, if the material of the charging roller does not match the material of the toner particles, a sufficient charge amount of toner cannot be obtained, and the toner charge amount may be insufficient. If the toner charge amount is insufficient, insufficient toner replenishment to the developer occurs, and a sufficient toner density in the developer cannot be obtained, which may cause a problem that a predetermined image density cannot be obtained. Also,
If the toner charge amount is insufficient, toner scattering and toner drop may occur, and the amount of background stain may increase and the image quality may be significantly deteriorated. Further, an increase in the amount of toner scattered in the image forming apparatus causes a problem that the inside of the image forming apparatus is contaminated and the accurate control of process control represented by toner concentration control inside the image forming apparatus is disturbed. Sometimes.

Here, in the above conventional developing device,
Since the toner replenishing roller is composed of NBR rubber, when toner made of powder based on polyester resin is used, the respective materials can be adapted to obtain a sufficient toner charge amount.

However, a toner such as a full-color toner used in a full-color copying machine, in which the pigment or dye component as a color-forming agent contained in the toner differs depending on the color, has different charging characteristics due to the different pigment or dye component. different. Therefore, in order to charge all the toners having different charging characteristics to a predetermined charging potential, it is necessary that the material of the toner replenishing roller is suitable for all the toners. However, for example, in the configuration of the conventional developing device described above, the toner replenishing roller made of NBR rubber can sufficiently charge all the toners having different pigment and dye components and different charging characteristics to a predetermined charging potential. There was a problem that some cases could not be done.

The present invention has been made in view of the above problems, and it is an object of the present invention to improve the chargeability of the toner and the image quality by optimizing the charging characteristics. To provide a developing device. Specifically, by defining the material of the toner replenishing member used for charging the toner and the material of the toner, it is possible to give a sufficient charge amount to the toner and obtain good image quality without scumming. Further, even when a plurality of toners are used as in a full-color copying machine and the charging characteristics of the respective toners are different, it is possible to prevent the occurrence of color unevenness by unifying the charging potentials of the toners of the respective colors. To provide a developing device.

[0007]

In order to achieve the above object, the invention of claim 1 is a developer carrier for carrying a two-component developer comprising a toner and a carrier, and the developer carrier. And a magnetic means for exerting a magnetic force on the developer to cause the developer to be carried on the developer carrier, and the toner carried on the surface of the developer on the developer carrier are brought into contact with each other. And a toner replenishing member for replenishing the developer on the developer carrying member with the toner by a potential difference from the developer carrying member, and a toner arranged so as to contact the surface of the toner replenishing member. The toner replenishing member is rotated, so that the toner on the toner replenishing member is thinned and frictionally charged at the same time by rotating the toner replenishing member. Replenish the developer, By rotating at least one of the magnetic pole of the net means and the developer carrying member, the developer carried on the developer carrying member is conveyed, and the latent image carrying member is formed by the toner in the developer. In a developing device for visualizing the latent image formed as described above, a powder based on polyester resin is used as the toner, and the toner replenishing member is composed of an NBR rubber roller coated on the surface with silicone-modified EPDM rubber. It is a feature. According to a second aspect of the present invention, a developer carrying member carrying a two-component developer comprising a toner and a carrier, and a developer carrying member incorporated in the developer carrying member, exerting a magnetic force on the developer, On the developer carrying member, a magnet means to be carried on the developer carrying member is brought into contact with the developer carried on the developer carrying member, and the toner carried on the surface is brought into contact with the developer carrying member. A toner replenishing member for replenishing the toner to the developer, and a toner regulating charging unit arranged so as to contact the surface of the toner replenishing member, and by rotating the toner replenishing member, The toner on the toner replenishing member is thinned and triboelectrically charged at the same time by the toner regulating charging means to replenish the toner on the developer on the developer carrying member, and the magnetic pole of the magnet means and the developer carrying member Rotate at least one By carrying out, the developer carried on the developer carrying body is conveyed, and the latent image formed on the latent image carrying body is visualized by the toner in the developer. It is characterized in that a powder based on polyester resin is used as the toner, and the toner replenishing member is made of a material in which a silicone-modified EPDM rubber and NBR rubber are mixed. According to a third aspect of the present invention, a developer carrying member carrying a two-component developer composed of a toner and a carrier and a developer carrying member incorporated in the developer carrying member exerts a magnetic force on the developer to carry out the developer. On the developer carrying member, a magnet means to be carried on the developer carrying member is brought into contact with the developer carried on the developer carrying member, and the toner carried on the surface is brought into contact with the developer carrying member. A toner replenishing member for replenishing the toner to the developer, and a toner regulating charging unit arranged so as to contact the surface of the toner replenishing member, and by rotating the toner replenishing member, The toner on the toner replenishing member is thinned and triboelectrically charged at the same time by the toner regulating charging means to replenish the toner on the developer on the developer carrying member, and the magnetic pole of the magnet means and the developer carrying member Rotate at least one By carrying out, the developer carried on the developer carrying body is conveyed, and the latent image formed on the latent image carrying body is visualized by the toner in the developer. It is characterized in that the toner replenishing member is made of a material based on silicon resin. The invention of claim 4 is
A developer carrying member carrying a two-component developer composed of a toner and a carrier, and a developer contained in the developer carrying member and exerting a magnetic force on the developer to carry the developer on the developer carrying member. The magnet means for contacting the developer and the toner carried on the surface of the developer on the developer carrier are brought into contact with each other, and the potential difference from the developer carrier causes the developer on the developer carrier to A toner replenishing member for replenishing the toner, and a toner regulating charging unit arranged so as to contact the surface of the toner replenishing member are provided. By thinning the toner on the replenishment member and frictionally charging the toner at the same time, replenishing the toner to the developer on the developer carrier, and rotating at least one of the magnetic pole of the magnet means and the developer carrier. , In a developing device that conveys the developer carried on the developer carrier and visualizes the latent image formed on the latent image carrier by the toner in the developer, a polyol resin is used as the toner. The powder is used as a base, and the toner replenishing member is made of silicon-modified EPDM rubber. According to a fifth aspect of the present invention, in the developing device according to the third or fourth aspect, the material constituting the toner replenishing member has a volume resistivity of 10 ⁴ to 10 ^15.
It is characterized in that it is Ω · cm.

[0008]

According to the present invention, since the toner replenishing member composed of the material determined in consideration of the toner material is used, the respective materials of the toner and the toner replenishing member are suitable, and the optimum toner is used. It can have charging characteristics. According to the fifth aspect of the present invention, the volume resistivity of the material forming the toner replenishing member is set to 10 ⁴ to 10 ¹⁵ Ω · cm in consideration of the resistance value of the developer. be able to.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to an electrophotographic copying machine (hereinafter referred to as a copying machine) which is an image forming apparatus will be described below. FIG. 2 shows the overall structure of a color copying machine which is one of the image forming apparatuses applied to the present invention.
This color copying machine is roughly classified into a scanner section 1 for reading an original and an image processing section 2 for electrically processing an image signal output from the scanner section 1 as a digital signal.
And a printer section 3 for forming an image on a transfer paper based on the image recording information for each color processed by the image processing section 2.

The scanner unit 1 has a lamp, for example, a fluorescent lamp 5, which exposes and scans a document on the document table 4. The reflected light from the original document that is exposed and illuminated by the fluorescent lamp 5 is reflected by the mirrors 6, 7, and 8 and enters the imaging lens 9.
Then, an image is formed on the dichroic prism 10 by the image forming lens 9 and is split into light of three wavelengths, for example, red R, green G, and blue B. The separated light of each wavelength is received by an individual light receiver, such as CCD 11R, 11C.
It is incident on G and 11B, respectively. Then, the movable optical system including the fluorescent lamp 5 and the mirrors 6, 7 and 8 is moved to perform sub-scanning of the document, and the CCDs 11R, 11G and 11 are scanned.
B converts the incident light into a digital signal while performing main scanning and outputs the digital signal. The output is subjected to necessary processing in the image processing unit 2, and recording color information of each color, for example, black BK, cyan C, magenta M, The signals are converted into signals for recording and forming each color of yellow Y. The signal from the image processing unit 2 is input to the printer unit 3 and sent to the laser light emitting devices 12BK, 12C, 12M and 12Y of the respective colors.

In the illustrated example, the printer section 3 is provided with four sets of recording devices 13BK, 13C, 13M and 13Y. Since each recording device 13 is composed of the same constituent member, the recording device for cyan C, for example, will be described here to simplify the description, and the other colors will be omitted. Then, for each color, the same parts are denoted by the same reference numerals, and the subscripts B, K, M, and Y are used to distinguish each color. Although FIG. 2 shows an example in which four colors BK, C, M, and Y are formed, a color image can be formed using only three colors. In this case, the number of recording devices in the figure may be reduced by one.

The recording device 13C includes, for example, a drum-shaped photosensitive member 14 in addition to the writing laser light emitting device 12C.
Has C. As is well known, around the photoconductor 14C,
Charging charger 15C, exposure device by laser light emitting device 12C, developing device 16C, transfer charger 17C,
A cleaning device 26C and the like are sequentially provided. A latent image of a cyan light image is formed on the photoconductor 14C which is rotationally driven by the main motor and uniformly charged by the charging charger 15C by exposure by the laser light emitting device 12C. In this case, the laser light emitting device 12C modulates and drives the laser light source by the cyan image signal from the image processing unit 2, and irradiates the photoconductor 14C with the laser light 27C having an intensity corresponding to the cyan image signal from the laser light source. The electrostatic latent image of the cyan light image on the photoconductor 14C is developed by the developing device 16C with a two-component developer (hereinafter, referred to as a developer) including cyan toner and carrier to form a cyan toner image. The transfer paper fed from the paper feed unit 19, for example, from one of the two paper feed cassettes by the paper feed roller 18, has its leading ends aligned by the registration rollers 20, and is sent to the transfer belt 21 at the same timing. The transfer paper conveyed by the transfer belt 21 is sequentially sent to the photoconductors 14BK, 14C, 14M, and 14Y on which visible images are formed, and the transfer chargers 17BK, 17C, 17M, and 17Y.
By this action, the black toner image, the cyan toner image, the magenta toner image, and the yellow toner image are transferred so as to overlap each other to form a full-color image. Further, the cleaning devices 26BK, 26C, 26M, and 26Y each have a brush roller for removing toner and a charge removing device, and after the transfer, the photoconductor 14
The toner remaining on BK, 14C, 14M and 14Y is removed. The transfer sheet onto which the visible image has been transferred is fixed by the fixing roller 22 and then ejected by the ejection roller 23.
In such an operation, the transfer paper is electrostatically attracted to the transfer belt 21 and is accurately conveyed along the belt. After the transfer belt 21 is conveyed to the transfer paper, the removing electric charge 28 removes the residual electric charges, and the belt cleaning device 29 removes the toner adhering to the surface. In addition, each photoconductor 14BK,
For 14C, 14M, and 14Y, a reflective photosensor (hereinafter referred to as P sensor) 24 is used as an optical sensor that optically detects the amount of toner adhered to the toner image pattern described later.
BK, 24C, 24M and 24Y are provided. (Hereafter, margin)

The image processing section 2 controls the operation of each section of the printer section 3 according to a predetermined program stored in the internal memory to write laser light emitting device 12B.
While changing the writing light quantity (laser power) at K, 12C, 12M, and 12Y from 1 to 7 gradations, it is possible to output a signal for forming a visible image pattern by the writing laser emitting device. The laser power at the time of writing the visible image pattern is set to gradation 4, for example. The developing bias V ₃ of each developing sleeve (for example, a developing sleeve 25C for cyan as a representative) is variably controlled by the image processing section 2.

In such a configuration, when the image signal is output as a digital signal from the scanner unit 1 and this signal is electrically processed by the image processing unit 2, the image recording information of each color is output from the image processing unit 2. Based on the printer unit 3
Forms an image on the transfer paper.

As in the case of the normal image formation as described above, in the case of the image processing unit 2, for example, cyan,
Laser emitting device 12C for writing, charging charger 1
The sensor pattern forming means including 7C and the developing device 16C forms a visible image pattern, and the pattern is read by the photosensor 24C. Then, based on the detection information of the visible image pattern, at least one of the developing bias of the developing device 16C, the charging potential of the photoconductor 24C, and the writing light amount in the writing laser emitting device 12C is appropriately controlled.

FIG. 1 is a schematic sectional view showing the overall construction of the developing device. The developing devices 16BK, 16C, 16
M and 16Y are composed of the same constituent members, and in order to simplify the description, for example, the developing device 16C for cyan C will be described here, and the description of the developing devices of other colors will be omitted. In FIG. 1, the developing device 16C includes a developing sleeve 25C inside, a developing tank 30C containing a developer, and a replenishing tank 31C containing replenishment toner.

The above-mentioned developing tank 30C has an opening at a position facing the photoconductor 14C, and a part of the peripheral surface of the developing sleeve 25C is exposed from this opening. The developing sleeve 25C has a rotation direction set so as to move in the same direction as the photoconductor 14C in the tangential direction, and a magnet including a main developing pole provided inside the photoconductor 14C at a position facing the photoconductor 14C. Fixed magnet group 32 as means
By C, a magnetic brush is formed on the surface of the photoconductor 14C.
It corresponds to the navel magnetic brush. Further, the developing bias voltage is applied to the developing sleeve 25C by the developing bias power source 33C. In addition, above the developing sleeve 25C, a replenishment roller 35C that is in contact with a supply roller 34C described later, a stirring screw 36C for conveying the developer from the back side to the front side, and the developer from the front side to the back side. A stirring screw 37C for carrying is provided. In addition to the supply roller 34C, for example, a metal thinning blade 38C and a sealing member 39C are in contact with the peripheral surface of the supply roller 35C over the entire width in the axial direction, and the supply toner is rubbed and supplied by the supply roller 34C. Is thinned by a thin layer blade 38C, carried on the surface, and conveyed toward the developing sleeve 25C. The replenishment roller 35C is connected to the drive system via the toner replenishment clutch 40C, and is configured to rotate while having a relative angular velocity while being in contact with the supply roller 34C when the toner replenishment clutch 40C is turned on. Further, the developing sleeve 25C and the stirring screw 36C,
37C is configured to rotate in synchronization with the main motor. Further, the developing sleeve 2 is provided in the opening of the developing tank 30C.
A doctor blade 41C that regulates the developer on 5C to a constant amount is provided.

On the other hand, cyan toner is stored in the replenishing tank 31C, and a supply roller 34C made of, for example, polyurethane is located at the outlet of the replenishing toner in the replenishing tank 31C. Sleeve 2
It is in contact with the replenishment roller 35C which is close to 5C.
The supply roller 34C is configured to rotate following the supply roller 35C and supply the toner in the supply tank 31C to the supply roller 35C. An agitator 42C for stirring toner is rotatably provided in the supply tank 31C.

Further, the supply roller 34C and the supply roller 35
The replenishing bias power source 43
A replenishment bias voltage is applied by C.

In the developing device 16C, the developer on the developing sleeve 25C is regulated to a certain amount by scraping off the excess developer from the developing sleeve 25C by the doctor blade 41C, and the developing region is rotated by the rotation of the developing sleeve 25C. Be transported to. The developer scraped off is conveyed to the one end side in the axial direction (back side in this embodiment) by the agitating screw 37C and is accumulated therein. When the developer reaches a certain amount or more, the developer enters the screw cover 44C and is conveyed by the stirring screw 36C in the direction opposite to the stirring screw 37C (in this embodiment, the front side).

Here, an image of a fixed pattern is written on the photoconductor 14C by the laser light emitting device 12C by the image signal of the fixed pattern stored in the image processing section 2, and an electrostatic latent image is formed. This electrostatic latent image is developed by the developer conveyed to the above-mentioned developing amount area and becomes a visible image 45C having a fixed pattern. The P sensor 24C detects the visible image 45C on the photoconductor 14C and the density of the background portion, and outputs a detection signal accordingly. The toner replenishment clutch 40C is controlled to be turned on / off by the control unit based on this detection signal, and the toner replenishment control is performed. The P sensor 24C may detect the toner concentration of the developer in the developing device 16C.

The other developing devices 16BK, 16M, 1
6Y also has the same configuration as the developing device 16C, performs the same developing operation, and performs the same toner supply control.

The toner replenishing operation from the replenishing tank 31C to the developing tank 30C will be described below. The P sensor 24
When the toner supply clutch 40C is turned on by the detection signal of C, the supply roller 35C and the supply roller 34C start to rotate. As a result, the toner in the supply tank 31C is carried on the surface of the supply roller 34C and supplied to the supply roller 35C. The toner supplied to the replenishing roller 35C is thinned by the thinning blade 38C as the replenishing roller 35C rotates, and at the same time, is triboelectrically charged to a predetermined potential.
Then, this toner comes into contact with the developer in the developing tank 30C as the replenishing roller 35C rotates. A bias voltage is applied to the replenishing roller 35C and the developing sleeve 25C by a replenishing bias power source 43C and a developing bias power source 33C, respectively, and the bias voltages are set to have a relative potential difference. Therefore, a bias potential difference is generated from the supply roller 35C in the developing sleeve 25C direction. Therefore, the toner on the replenishing roller 35C is replenished with the developer on the developing sleeve 25C.

By the way, in the developing device having the above-mentioned structure, the toner supplied from the replenishing tank 31C to the developing tank 30C comes into contact with the replenishing roller 35C and is regulated in a thin layer by the thinning blade 38C. The superiority or inferiority of the charging characteristics of the toner is determined by the relationship between the material of the toner and the material of the replenishing roller 35C. That is, when the material of the toner and the material of the supply roller 35C are matched with each other, it is possible to obtain a sufficient toner charge amount without deterioration of image quality.

According to the experiments conducted by the present inventors, a polyester resin toner (powder toner based on polyester resin) is used as a full-color toner, and the surface of NBR rubber is coated with silicon-modified EPDM rubber. When using the replenishing roller 35C, the optimum toner charging characteristics could be obtained.

According to the experiments conducted by the present inventors, a polyester resin type toner (powder toner based on polyester resin) was used as a full color toner, and NBR was used.
When the replenishing roller 35C made of a blend rubber of rubber and silicon-modified EPDM rubber was used, the optimum toner charging characteristics could be obtained as shown in Table 1. In addition, in Table 1, the value of H-Q / M is usually -1.0 μC.
If it is less than / g, image quality is deteriorated due to insufficient charging.

[Table 1] HQ / M H-M / A Remarks (μC / g) (mg / cm ² ) Implementation effect of this example −5.2 0.41 Normal temperature and normal humidity environment Conventional example (insufficient charging) -0.72 0.31 Normal temperature and normal humidity environment H-Q / M: Toner charge amount per unit mass H-M / A: Toner adhesion amount per unit surface area of replenishing roller

According to experiments conducted by the inventors of the present invention, a replenishing roller 35C was prepared by applying a combination of a silicon resin, a combination of this silicon resin, CCA (charge control agent) and carbon black to a core metal. When used as
For example, in the case of a polyester resin-based toner (powder toner based on polyester resin) as a full-color toner, optimum toner charging characteristics could be obtained.

Further, according to the experiments conducted by the present inventors, when a polyol resin-based toner (powder toner based on a polyol resin) is used as the full-color toner, NBR (nitr butadiene) rubber and silicon-modified E are used.
Replenishing roller 3 made of blended rubber with PDM rubber
Depending on 5C, the toner could not be thinned. However, when the replenishing roller 35C constituted by applying a combination of the silicone resin, CCA and carbon black to the core metal based on the silicone resin is used, the polyol resin system as the full color toner is used. In the toner (powder toner based on polyol resin), the optimum toner charging characteristics could be obtained, and the toner could be satisfactorily thinned.

According to the experiments conducted by the present inventors, a polyol resin type toner (powder toner based on a polyol resin) is used as a full color toner, and a replenishing roller 35C made of silicon modified EPDM rubber is used. Then, as shown in Table 2, the optimum toner charging characteristics could be obtained. In this case, the replenishing roller 35C has a volume resistivity of 10 ⁵ to 10 ¹⁴ Ω · cm, specifically 1 × 10 ¹⁰ Ω · cm. In Table 2, when the value of HQ / M is usually lower than -1.0 μC / g, image quality is deteriorated due to insufficient charging.

[Table 2] HQ / M H-M / A Remark (μC / g) (mg / cm ² ) Implementation effect of this example −10 0.33 Normal temperature and normal humidity environment Conventional example (insufficient charging) −0 .72 0.31 normal temperature and normal humidity environment H-Q / M: toner charge amount per unit mass H-M / A: toner adhesion amount per refill roller unit surface area

By the way, in order to obtain more optimal toner charging characteristics, the replenishment roller 3 should be considered in consideration of the resistance value of the developer.
A volume resistivity of 5C must be set. According to the experiments by the present inventors, as shown in Table 3, by using the replenishing roller 35C having a volume resistivity of 10 ⁴ to 10 ¹⁵ Ω · cm, the replenishing roller 35C is made of a silicone resin as a base, A polyester resin-based toner (powder toner based on a polyester resin) or a polyol resin-based toner is used as a full-color toner by using a material obtained by applying a combination of a silicone resin, CCA and carbon black to a core metal. When toner (powder toner based on polyol resin) is used and when a polyol resin-based toner (powder toner based on polyol resin) is used as a full-color toner, a replenishing roller composed of silicon-modified EPDM rubber In any case, when 35C is used, more optimal toner charging characteristics are obtained. It could be. Here, Table 3 uses a silicone resin as a base for the replenishing roller 35C, and uses a combination of the silicone resin, CCA, and carbon black applied to a core metal, and a polyester resin as a full-color toner. The experimental results when a system toner (powder toner based on polyester resin) is used are shown. In Table 3, HQ / M
If the value is less than -1.0 μC / g, image quality is deteriorated due to insufficient charging.

[Table 3] HQ / M H-M / A (μC / g) (mg / cm ² ) Conventional example (insufficient charging) −0.72 0.31 actual volume resistivity actual (Ω · cm) Implementation 1 0.0 × 10 ⁴ −7.05 0.28 Example 4.0 × 10 ⁷ −7.21 0.28 Effect 4.0 × 10 ¹¹ −13.03 0.31 Result 1.3 × 10 ¹⁵ − 14.17 0.32 H-Q / M: toner charge amount per unit mass H-M / A: toner adhesion amount per unit surface area of replenishing roller

As described above, according to the present embodiment, by setting the material of the toner and the material of the replenishing roller 35C so as to match each other, even if the pigment or dye component in the full-color toner is different, the replenishing roller 35C is not affected. Toner with stable charging characteristics and stable charging polarity is used in the developing tank 3.
The developer in 0C can be replenished, and an image of good quality without scumming and toner scattering / falling can be obtained.

[0032]

According to the present invention, the material of the toner and the material of the toner replenishing member are set so as to match each other, so that the charging characteristic of the toner on the toner replenishing member is stabilized. , Toner with stable charging polarity can be replenished to the developer, so background stains and toner scattering
There is an effect that it is possible to obtain an image of good quality without toner falling. According to the invention of claim 5, by determining the volume specific resistance of the material forming the toner replenishing member in consideration of the resistance value of the developer, it is possible to obtain a more optimal toner charging characteristic. There is an effect that a good image can be obtained without the problem that the toner on the member is insufficiently charged and the image quality is deteriorated.

[Brief description of drawings]

FIG. 1 is a front view showing a schematic configuration of a developing device according to an embodiment.

FIG. 2 is a front view showing a schematic configuration of a copying machine to which the developing device is applied.

[Explanation of symbols]

 14C Photoconductor 16C Developing device 25C Developing sleeve 30C Developing tank 31C Replenishing tank 32C Fixed magnet group 33C Developing bias power source 34C Supply roller 35C Replenishing roller 36C Stirring screw 37C Stirring screw 38C Thinning blade 39C Sealing member 40C Toner replenishing clutch 41C Doctor blade 42C Agitator 43C Replenishment bias power supply

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical display location G03G 15/08 501 A 504 A C 9/087 15/09 Z (72) Inventor Nobuo Takami Tokyo 1-3-6 Nakamagome Ota-ku, Ricoh Co., Ltd. (72) Inventor Kaoru Yoshimatsu 1-3-6 Nakamagome, Ota-ku Tokyo, Ricoh Co., Ltd. (72) Inventor Katsuji Watanabe Nakata, Ota-ku, Tokyo Magome 1-3-6, Ricoh Co., Ltd. (72) Inventor Kazuyuki Sugihara 1-3-6 Nakamagome, Ota-ku, Tokyo In-house Ricoh Co., Ltd. (72) Takayuki Maruta 1-chome, Nakamagome, Ota-ku, Tokyo No. 3-6 In Ricoh Co., Ltd.

Claims (5)

[Claims] 1. A developer carrier for carrying a two-component developer comprising a toner and a carrier, and a developer contained in the developer carrier and exerting a magnetic force on the developer to develop the developer. A magnet means to be carried on the developer carrying member is brought into contact with the toner carried on the surface of the developer on the developer carrying member, and the toner on the developer carrying member is caused by a potential difference from the developer carrying member. A toner replenishing member for replenishing the toner to the developer and a toner regulating charging unit arranged so as to contact the surface of the toner replenishing member are provided, and the toner regulating member is rotated to rotate the toner regulating member. At least one of the magnetic pole of the magnet means and the developer carrying member is replenished with the developer on the developer carrying member by thinning the toner on the toner replenishing member by means of charging means and simultaneously triboelectrically charging the toner. Rotate In the developing device, the developer carried on the developer carrying body is conveyed by and the latent image formed on the latent image carrying body is visualized by the toner in the developer. The developing device is characterized in that a powder based on polyester resin is used as the toner replenishing member and the toner replenishing member is composed of an NBR rubber roller having a surface coated with silicon-modified EPDM rubber. 2. A developer carrying member carrying a two-component developer comprising a toner and a carrier, and a developer contained in the developer carrying member, exerting a magnetic force on the developer to develop the developer. A magnet means to be carried on the developer carrying member is brought into contact with the toner carried on the surface of the developer on the developer carrying member, and the toner on the developer carrying member is caused by a potential difference from the developer carrying member. A toner replenishing member for replenishing the toner to the developer and a toner regulating charging unit arranged so as to contact the surface of the toner replenishing member are provided, and the toner regulating member is rotated to rotate the toner regulating member. At least one of the magnetic pole of the magnet means and the developer carrying member is replenished with the developer on the developer carrying member by thinning the toner on the toner replenishing member by means of charging means and simultaneously triboelectrically charging the toner. Rotate In the developing device, the developer carried on the developer carrying body is conveyed by and the latent image formed on the latent image carrying body is visualized by the toner in the developer. As a developing device, a powder based on polyester resin is used as the toner replenishing member, and the toner replenishing member is made of a material in which a silicone-modified EPDM rubber and NBR rubber are mixed. 3. A developer carrying member carrying a two-component developer comprising a toner and a carrier, and a developer contained in the developer carrying member and exerting a magnetic force on the developer to develop the developer. A magnet means to be carried on the developer carrying member is brought into contact with the toner carried on the surface of the developer on the developer carrying member, and the toner on the developer carrying member is caused by a potential difference from the developer carrying member. A toner replenishing member for replenishing the toner to the developer and a toner regulating charging unit arranged so as to contact the surface of the toner replenishing member are provided, and the toner regulating member is rotated to rotate the toner regulating member. At least one of the magnetic pole of the magnet means and the developer carrying member is replenished with the developer on the developer carrying member by thinning the toner on the toner replenishing member by means of charging means and simultaneously triboelectrically charging the toner. Rotate In the developing device, the developer carried on the developer carrying body is conveyed by and the latent image formed on the latent image carrying body is visualized by the toner in the developer. A developing device in which the replenishment member is made of a material based on silicon resin. 4. A developer carrying member carrying a two-component developer comprising a toner and a carrier, and a developer contained in the developer carrying member and exerting a magnetic force on the developer to develop the developer. A magnet means to be carried on the developer carrying member is brought into contact with the toner carried on the surface of the developer on the developer carrying member, and the toner on the developer carrying member is caused by a potential difference from the developer carrying member. A toner replenishing member for replenishing the toner to the developer and a toner regulating charging unit arranged so as to contact the surface of the toner replenishing member are provided, and the toner regulating member is rotated to rotate the toner regulating member. At least one of the magnetic pole of the magnet means and the developer carrying member is replenished with the developer on the developer carrying member by thinning the toner on the toner replenishing member by means of charging means and simultaneously triboelectrically charging the toner. Rotate In the developing device, the developer carried on the developer carrying body is conveyed by and the latent image formed on the latent image carrying body is visualized by the toner in the developer. As a developing device, a powder based on a polyol resin is used as the toner replenishing member and the toner replenishing member is made of silicon-modified EPDM rubber. 5. The developing device according to claim 3, wherein the material constituting the toner replenishing member has a volume resistivity of 10 ⁴ to 10 ¹⁵ Ω · cm.