JP2006133435A - Development device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a development device capable of preventing deterioration in the quality of printed images. <P>SOLUTION: The developing device shown in Fig. 1 comprises a developing roller 2 disposed opposite a photoreceptor drum 1; a toner layer thickness regulating roller 3 disposed opposite the developing roller 2 and rotated in the same direction as that of the developing roller 2; a toner supply roller 4 for supplying toner to the developing roller 2; a toner layer thickness regulating blade 5, disposed in firm contact with the toner layer thickness regulating roller 3; and nonmagnetic toner 6 stored in a toner hopper 7. The toner layer thickness regulating roller 3 is a roller of conductive rubber, such as silicone rubber whose electrical resistance is in the range of 10<SP>5</SP>to 10<SP>8</SP>[Ω] and the surface roughness Rz is not smaller than 6 [μm] but is not larger than 20 [μm]. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a developing device in an image forming apparatus such as an electrophotographic printer, FAX, or copying machine.

  FIG. 12 shows a developing device disclosed in JP-A-7-44007. In this developing device, toner 106 is stored in a toner hopper 107. A developing roller 102 disposed opposite to the photosensitive drum 101, a toner supply roller 104 disposed opposite to the developing roller 102 to supply toner to the outer peripheral surface of the developing roller 102, and a developing roller 102 above the developing roller 102 A toner layer thickness regulating roller 103 that regulates the thickness of the toner adhering to the outer peripheral surface of the toner is disposed. A blade 105 that scrapes off the toner adhering to the surface is in contact with the outer peripheral surface of the toner layer thickness regulating roller 103. Below the developing roller 102 is provided a toner collecting roller 108 that collects toner remaining on the surface of the developing roller 102 without being developed into the electrostatic latent image on the surface of the photosensitive drum 101. (See Patent Document 1).

JP 7-44007 A

  In such a conventional developing device, the toner 106 is supplied to the surface of the developing roller 102 by the toner supply roller 104. The toner 106 supplied to the surface of the developing roller 102 is frictionally charged by passing between the toner layer thickness regulating roller 103 and the blade 105 according to the rotation. Since the triboelectric charge amount increases as the contact pressure between the toner layer thickness regulating roller 103 and the blade 105 increases, the blade 105 is in contact with the surface of the toner layer thickness regulating roller 103 with a relatively strong pressure. As a result, the toner is melted and fixed to the surface of the toner layer thickness regulating roller 103 and the blade 105 due to frictional heat, and as a result, the toner is not supplied well at the toner fixing portion and appears as a white stripe on the recording medium. In addition, by repeating high density printing, the surface of the toner layer thickness regulating roller 103 is worn, and the surface roughness of the roller is reduced, so that the toner conveying force is reduced and a thin layer of toner can be formed on the surface of the developing roller 102. Therefore, it becomes difficult to obtain a printed image having a uniform density.

In order to solve the above problems, a first developing device of the present invention includes a developing member that develops an electrostatic latent image with a developer on an electrostatic latent image carrier that carries the electrostatic latent image, and a developing member. A toner layer thickness regulating member that contacts and rotates in the same direction as the rotation direction of the developing member, and is developed on the upstream side of the toner layer thickness regulating member in the rotating direction of the developing member and in contact with or close to the outer peripheral surface of the developing member A toner supply member that supplies toner to the member; and a toner layer thickness regulating blade that contacts the toner layer thickness regulating member to form a toner layer, and the surface roughness Rz of the toner layer thickness regulating member is 6 [μm]. It is characterized by being 20 [μm] or less.
The second developing device of the present invention includes a developing member that develops an electrostatic latent image with a developer on an electrostatic latent image carrier that carries the electrostatic latent image, and a developer member that contacts the developing member and contacts the developing member. A toner layer thickness regulating member that rotates in the same direction as the rotation direction, and a toner layer that is installed on the upstream side of the toner layer thickness regulating member in the rotation direction of the developing member and that is in contact with or close to the outer peripheral surface of the developing member And a toner layer thickness regulating blade that forms a toner layer in contact with the toner layer thickness regulating member, the toner layer thickness regulating blade has a curved portion, and the curved portion is used as the toner layer thickness regulating member. A voltage is applied to the toner layer thickness regulating blade while making contact.

  By setting the surface roughness Rz of the toner layer thickness regulating roller to 6 [μm] or 20 [μm] or less, the toner melts and adheres to the surface of the toner layer thickness regulating roller and the toner layer thickness regulating blade, and white streaks appear on the printed image. It is possible to prevent the print image quality from being deteriorated. Further, it is possible to prevent a uniform toner thin layer from being formed on the surface of the toner layer thickness regulating roller and to prevent the density on the printed image from becoming non-uniform.

  Examples of the present invention will be described in detail below.

  Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 11 is a schematic configuration diagram of an image forming apparatus used in an embodiment of the present invention. FIG. 1 is a schematic configuration diagram of a developing device according to Embodiment 1 of the present invention. 1 is a photosensitive drum carrying an electrostatic latent image, 2 is opposed to the photosensitive drum 1 and is a developing roller for developing the electrostatic latent image, 3 is opposed to the developing roller 2 and is in the same direction as the developing roller 2 The toner layer thickness regulating roller 4 that rotates in the direction of the rotation of the developing roller 2 is arranged in contact with or in proximity to the developing roller 2 upstream of the toner layer thickness regulating roller 3 in the rotation direction of the developing roller 2 and supplies toner to the developing roller 2 A supply roller 5 is a toner layer thickness regulating blade disposed in contact with the toner layer thickness regulating roller.

Reference numeral 6 denotes a nonmagnetic toner (hereinafter referred to as toner), and reference numeral 7 denotes a toner hopper for storing the nonmagnetic toner 6. 8 is a power source for applying a voltage to the toner layer thickness regulating roller 3, 9 is a power source for applying a voltage to the developing roller 2, and 10 is a power source for applying a voltage to the toner supply roller 4. Here, the toner layer thickness regulating blade 5 is made of a thin metal plate such as stainless steel. The toner layer thickness regulating roller 3 is a rubber roller having semiconductivity such as silicone rubber having an electric resistance in the range of about 10 ⁵ to 10 ⁸ [Ω], and has a surface roughness Rz of 6 [μm] or more and 20 [μm]. The following are used.

  Next, the operation of the developing device having the above configuration will be described. In FIG. 1, each roller rotates at a predetermined speed in the direction of the arrow. The toner 6 is frictionally charged by the toner supply roller 4. The charged toner 6 is applied on the surface of the developing roller 2 by the electrostatic force formed by the voltage difference between the voltage VD applied to the developing roller 2 by the power source 9 and the voltage VS applied to the toner supply roller 4 by the power source 10. The toner 6 is supplied by adhering. The toner 6 supplied on the surface of the developing roller 2 passes between the toner layer thickness regulating roller 3 as the developing roller 2 rotates and is thinned on the surface of the developing roller 2, and the toner layer thickness regulating roller 3 is divided into those that adhere to the surface of the toner layer thickness regulating roller 3 depending on the transportability of the surface, but the amount is applied to the developing roller 2 by the voltage VL applied to the toner layer thickness regulating roller 3 by the power source 8 and the power source 9. It is controlled by the voltage difference | VL−VD |

  The toner 6 on the surface of the toner layer thickness regulating roller 3 passes between the toner layer thickness regulating blade 5 and is thinned. The toner thinned on the surface of the toner layer thickness regulating roller 3 moves to the surface of the developing roller 2 by the electrostatic force generated by the voltage difference | VL−VD |. The toner thinned on the surface of the developing roller 2 has a desired weight per unit area by controlling the voltages VL, VS, VD, and the peripheral speed ratio of the developing roller 2, the toner layer thickness regulating roller 3, and the toner supply roller 4. It is controlled to become.

  As described above, the toner 6 that is thinned and charged on the surface of the developing roller 2 adheres to the surface of the photosensitive drum 1 on which the electrostatic latent image is formed by the charging roller 205 and the exposure unit 206 by electrostatic force. Developed with The exposure unit 206 is made up of LEDs (Light Emitting Diodes) arranged in an array, and selectively emits light based on print image data transmitted from a device control unit (not shown). Note that the recording medium 201 loaded on the medium cassette 202 that accommodates the recording medium 201 is fed by the hopping roller 203 in order from the top surface. The fed recording medium 201 is conveyed between the photosensitive drum 1 and the transfer roller 207 by the registration roller 204, and the toner image developed on the photosensitive drum 1 is transferred onto the recording medium 201. If the apparatus handles a plurality of colors such as yellow, magenta, cyan, and black, for example, the series of development and transfer processes includes as many developing devices and transfer devices as the number of colors.

  At this time, the toner 6 not transferred but remaining on the surface of the photosensitive drum 1 is scraped off by the cleaning roller 208 and stored in the storage unit 209. Further, the toner image transferred onto the recording medium 201 is provided with a heat roller (not shown) that rotates in the direction of the arrow, and a pressure roller 211 that rotates in the direction of the arrow while being pressed against the fixing roller 210 with a predetermined pressure. The toner on the recording medium 201 is melted and fixed on the recording medium 201 by being conveyed and heated and pressed. The recording medium 201 on which the toner image is fixed is further conveyed and discharged to the outside of the apparatus by a medium discharge unit (not shown). The toner supply roller 4, the charging roller 205, and the cleaning roller 208 are not limited in the rotation direction, and may rotate in the direction opposite to the rotation direction arrow shown in FIG. 11. Further, the charging roller 205 and the cleaning roller 208 may be fixed without rotating.

  Next, 10 [° C.], 20 [%] low temperature and low humidity environment (hereinafter referred to as “L / L”), 20 [° C.], 50 [%] room temperature and normal humidity environment (hereinafter referred to as “N / N”) FIG. 4 and FIG. 5 show the evaluation results of printed images in a high-temperature and high-humidity environment (hereinafter referred to as “H / H”) of 27 [° C.] and 80 [%]. FIG. 4A is a diagram showing the results of toner adhesion evaluation when the operating environment is L / L. FIG. 4B is a diagram showing the result of toner adhesion evaluation when the operating environment is N / N. FIG. 4C is a diagram showing the result of toner adhesion evaluation when the operating environment is H / H. FIG. 5A is a diagram showing the results of evaluation of toner thin layer formation when the operating environment is L / L. FIG. 5B is a diagram showing the results of evaluation of toner thin layer formation when the operating environment is N / N. FIG. 5C is a diagram showing the results of evaluation of toner thin layer formation when the operating environment is H / H.

  Here, the evaluation item “toner fixation” is determined immediately after repeatedly printing about 20000 sheets of a printing pattern having a width of 10 [mm] and a density of 100 [%] as shown in FIG. As shown in FIG. 3, when black (100 [%] density) is printed on the entire surface of the medium (hereinafter referred to as an evaluation medium), it is visually determined whether white streaks are confirmed in the medium conveyance direction on the printed image. It was done. Note that the position on the medium of the printing area having a width of 10 [mm] is not particularly defined, and the width may be wider or narrower than 10 [mm] as long as the printing area and the non-printing area can be secured. Absent.

  Evaluation of “toner thin layer formation” as an evaluation item is as follows. On the evaluation medium in FIG. 3, as shown in the figure, the printing direction is 25 [mm] from the top and bottom edges of the medium and 50 [from the left and right edges]. The optical density, that is, Optical Density (OD) value is optically applied to a total of 6 points, each of 4 points in total in the transport direction, 2 points at the upper end of the conveyance direction, and 2 points at the lower end. Measured using a concentration measuring device (product name “X-Rite”, “X-Rite”), and in the measured OD value of 6 points, the average value A of the media upper end 3 points and the media lower end 3 Whether or not the average value B of the points falls within the range of the density reference value 1.4 to 1.6, which is the density reference value of the image forming apparatus used in this embodiment, was determined. It has been experimentally known that color reproduction is very good within this range. Further, the method of taking the concentration measurement point is not limited to this, and the position and number of measurement points can be arbitrarily set. However, when the circumferential length of the photosensitive drum 1 is one cycle, it is desirable to collect the measurement points from a printed image of a plurality of cycles on the photosensitive drum 1. This is because it is difficult to confirm a density change in a wide range on the same medium in the density comparison only within the same period.

  In FIG. 4, ◯ indicates that no white streaks can be visually confirmed on the evaluation medium in the medium conveyance direction, and therefore, it is determined that there is no toner sticking. X indicates that there are white streaks in the medium conveyance direction on the evaluation medium. It can be confirmed and thus indicates that toner sticking has occurred. In FIG. 5, since the average value A and average value B of the OD values in the evaluation medium are within the density reference value, it can be determined that the density is almost uniform over the entire print area, and the toner layer thickness regulating blade 5 It shows that a uniform toner thin layer was formed on the surface. X indicates that the average value A or average value B of the OD values in the evaluation medium or neither the average value A nor the average value B falls within the density reference value, and it can be determined that the density is not uniform over the entire print area. This indicates that a uniform toner thin layer was not formed on the surface of the toner layer thickness regulating blade 5.

  In Example 1 of the present invention, as shown in FIG. 4, it can be seen that toner adhesion does not occur when the surface roughness Rz is 6 μm or more. This is because, as the surface roughness of the toner layer thickness regulating roller 3 is larger, the toner transportability is higher and the toner layer weight per unit area on the surface of the toner layer thickness regulating roller 3 is increased. It shows that the amount of heat received by the friction between the roller 3 and the toner layer thickness regulating blade 5 has decreased. When the surface roughness Rz is 4 [μm] or less, the toner transportability is low, and the toner layer weight per unit area on the surface of the toner layer thickness regulating roller 3 is small. The amount of heat received due to the friction between the toner layer thickness regulating blade 5 and the toner layer thickness regulating blade 5 increases, indicating that toner sticking has occurred on the surface of the toner layer thickness regulating roller 3 and the toner layer thickness regulating blade 5. As shown in FIG. 5, when the surface roughness Rz of the toner layer thickness regulating roller 3 is 25 [μm] or more, the toner cannot be transported at a constant level, resulting in uneven thin layer formation and uniform toner thinness. This indicates that the layer could not be formed.

  As described above, the toner layer thickness regulating roller can be controlled by setting the surface roughness Rz of the toner layer thickness regulating roller 3 to 6 [μm] or more and 20 [μm] or less regardless of the operating environment such as temperature and humidity. It is possible to prevent the print image quality from being deteriorated by causing white streaks in the medium conveyance direction on the printed image by being fused and fixed to the surface 3 and the toner layer thickness regulating blade 5. Further, it is possible to prevent a uniform toner thin layer from being formed on the surface of the toner layer thickness regulating roller 3 and to prevent the density on the printed image from becoming non-uniform.

  Next, a second embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a schematic configuration diagram of the developing device. The basic configuration is the same as that of Example 1, but the toner layer thickness regulating roller 3 having a surface hardness of JISA 18 degrees or more and JISA 60 or less is used. Since the operation of the developing device of this embodiment is the same as that of the first embodiment, a description thereof will be omitted. Next, the evaluation results of the printed images at “L / L”, “N / N”, and “H / H” are shown in FIGS. FIG. 6A is a diagram showing the result of horizontal stripe evaluation when the operating environment is L / L. FIG. 6B is a diagram showing the result of horizontal stripe evaluation when the operating environment is N / N. FIG. 6C is a diagram showing the result of horizontal stripe evaluation when the operating environment is H / H. FIG. 7A is a diagram showing the results of toner adhesion evaluation when the operating environment is L / L. FIG. 7B is a diagram showing the result of toner adhesion evaluation when the operating environment is N / N. FIG. 7C is a diagram showing the result of toner adhesion evaluation when the operating environment is H / H.

  Here, the evaluation item “horizontal streak” is determined immediately after repeatedly printing about 20000 sheets with a printing pattern of 10 [mm] width and 100 [%] density on a recording medium as shown in FIG. When black (100 [%] density) is printed on the entire surface of the medium (hereinafter referred to as an evaluation medium) as shown in FIG. Whether or not is determined visually. Note that the position on the medium of the printing area having a width of 10 [mm] is not particularly defined, and the width may be wider or narrower than 10 [mm] as long as the printing area and the non-printing area can be secured. Absent.

  In FIG. 6, a circle mark indicates that no horizontal streak could be confirmed on the evaluation medium, so that the surface of the toner layer thickness regulating roller 3 is distorted, that is, a so-called dent is not formed, and a cross mark indicates a horizontal streak on the evaluation medium. It can be confirmed that the surface of the toner layer thickness regulating roller 3 is distorted and a so-called dent is formed. In Example 2 of the present invention, as shown in FIG. 6, it can be seen that no lateral streak occurs when the surface hardness of the toner layer thickness regulating roller 3 is JISA 18 degrees or more. Conversely, at 13 degrees JISA, horizontal stripes are generated.

  This is because if the surface hardness of the toner layer thickness regulating roller 3 is low, permanent deformation occurs at the pressure contact portion of the toner layer thickness regulating blade 5 on the surface of the toner layer thickness regulating roller 3 when the toner layer thickness regulating roller 3 is in a non-operating state. Since permanent distortion is largely related to the initial distortion amount, the toner layer thickness regulating roller 3 needs to have a certain degree of surface hardness in order to prevent deformation due to the pressure contact force of the toner layer thickness regulating blade 5. On the other hand, if the surface hardness is too high, the frictional heat generated between the toner layer thickness regulating blade and the toner is likely to be fixed. Next, as shown in FIG. 7, when the surface hardness of the toner layer thickness regulating roller 3 is JISA 70 degrees or more, white streaks are confirmed in the medium transport direction on the evaluation medium, indicating that toner sticking has occurred.

  As described above, the pressure contact portion between the toner layer thickness regulating roller 3 and the toner layer thickness regulating blade 5 when the surface hardness of the toner layer thickness regulating roller 3 is JISA 18 degrees or more and JISA 60 degrees or less regardless of the operating environment such as temperature and humidity. As a result, the surface of the toner layer thickness regulating roller 3 is distorted, and the thickness of the toner layer is increased at the distorted portion, and it is possible to prevent deterioration of the print image quality due to a high density horizontal stripe on the print image. Further, it is possible to prevent the toner from being melted and fixed to the surface of the toner layer thickness regulating roller 3 and the toner layer thickness regulating blade 5 to cause white streaks in the medium conveying direction on the print image, thereby deteriorating the print image quality.

  Next, Embodiment 3 of the present invention will be described with reference to the drawings. FIG. 8 shows a schematic configuration diagram of the developing device. FIG. 9 is a partially enlarged view of the toner layer thickness regulating blade 5. 1 is a photosensitive drum carrying an electrostatic latent image, 2 is opposed to the photosensitive drum 1 and is a developing roller for developing the electrostatic latent image, 3 is opposed to the developing roller 2 and is in the same direction as the developing roller 2 The toner layer thickness regulating roller 4 that rotates in the direction of the rotation of the developing roller 2 is arranged in contact with or in proximity to the developing roller 2 upstream of the toner layer thickness regulating roller 3 in the rotation direction of the developing roller 2 and supplies toner to the developing roller 2 A supply roller 5 is a toner layer thickness regulating blade disposed in contact with the toner layer thickness regulating roller.

Reference numeral 6 denotes a non-magnetic toner (hereinafter simply referred to as toner), and reference numeral 7 denotes a toner hopper for storing the toner 6. 8 is a power source for applying a voltage to the toner layer thickness regulating roller 3, 9 is a power source for applying a voltage to the developing roller 2, 10 is a power source for applying a voltage to the toner supply roller 4, and 11 is a voltage to the toner regulating blade 5. It is a power supply to do. Here, the toner layer thickness regulating roller 3 is a rubber roller having semiconductivity such as silicone rubber having an electric resistance in a range of about 10 ⁵ to 10 ⁸ [Ω]. The tip of the toner layer thickness regulating blade 5 has an R shape, and the curved portion 12 is pressed against the toner layer thickness regulating roller 3. In this embodiment, a stainless steel plate having a thickness of 80 [μm] is used for the toner regulating blade 5, the radius of the curved portion 12 formed at the tip is 0.35 [mm], and the pressing force of the tip is 10 to 50 [g / cm] was used. The toner layer thickness regulating blade 5 may be anything as long as it is a metal thin plate for a spring, and any thickness can be used up to about 1 [mm] and the radius of the arc portion is about 0.2 to 1 [mm]. Things can be used. The toner layer regulating blade 5 used in this embodiment is bent at a substantially right angle by the curved portion 12, but the bending angle can be set as appropriate.

  Next, the operation of the developing device having the above configuration will be described. In FIG. 8, each roller rotates at a predetermined speed in the direction of the arrow. The toner 6 is frictionally charged by the toner supply roller 4. The charged toner 6 is applied on the surface of the developing roller 2 by the electrostatic force formed by the voltage difference between the voltage VD applied to the developing roller 2 by the power source 9 and the voltage VS applied to the toner supply roller 4 by the power source 10. Supplied. The toner 6 supplied on the surface of the developing roller 2 passes between the toner layer thickness regulating roller 3 as the developing roller 2 rotates and is thinned on the surface of the developing roller 2, and the toner layer thickness regulating roller 3 is divided into those adhering to the surface of the toner layer thickness regulating roller 3 depending on the transportability of the surface, but the amount is the voltage difference between the voltage VL and VD applied to the toner layer thickness regulating roller 3 by the power supply 8 | VL−VD Is controlled by |.

  The toner 6 on the surface of the toner layer thickness regulating roller 3 is thinned by passing between the toner layer thickness regulating blade 5 and supplied with a charge by the voltage VB applied to the toner layer thickness regulating blade 5. Stable charge amount. The toner thinned on the surface of the toner layer thickness regulating roller 3 moves to the surface of the developing roller 2 by the electrostatic force generated by the voltage difference | VL−VD |. Then, the toner thinned on the surface of the developing roller 2 is supplied to the surface of the photosensitive drum 1.

  FIG. 10 shows the fog evaluation result. Here, the fog is a toner charged on the photosensitive drum 1 and charged with a reverse polarity to the regular charge or a toner having a low charge amount. In FIG. 10, ΔE [%] is in the Lab color coordinate system. The amount of fogging of the toner to be defined is represented. A larger value indicates more fogging, and a smaller value indicates less fogging. In the image forming apparatus used in this embodiment, the print quality is guaranteed by suppressing the value of ΔE to about 0.6. Since | VD | = 200 [V] and | VB | = 400 [V] are applied, the evaluation is performed in the case of | VL | = 300 [V] and | VL | = 400 [V]. It was. This is because the relationship of | VD | ≦ | VL | ≦ | VB | is required in the process of attaching toner to the surface of the photosensitive drum 1 using electrostatic force. When the toner to be used is a negatively charged toner, each applied voltage is also applied with a negative voltage, and when the toner to be used is a positively charged toner, each applied voltage is also applied with a positive voltage.

  As shown in FIG. 10, it can be seen that the magnitude of the voltage VB applied to the toner layer thickness regulating blade 5 by the power source 11 is related to the amount of fog on the surface of the photosensitive drum. Then, a voltage VB satisfying | VL | ≦ | VB | is applied to the toner layer thickness regulating blade 5 with respect to the voltage VL applied to the toner layer thickness regulating roller 3, thereby setting the value of ΔE to 0.6. The amount of fog on the surface of the photosensitive drum 1 can be further reduced below the print quality guarantee value. This is because the toner is charged not only by frictional charging but also by a charge supply from a conductive material, resulting in a more stable charge amount. Note that the voltage value to be applied in this embodiment is not limited to the above-described value, and can be changed as appropriate.

  As described above, regardless of the operating environment such as temperature and humidity, the voltage VL applied to the toner layer thickness regulating roller 3 and the voltage VB applied to the toner layer thickness regulating blade 5 satisfy | VL | ≦ | VB | When satisfied, the amount of toner fog on the surface of the photosensitive drum 1 can be reduced, and further improvement in printing quality can be realized.

  The present invention is applicable to a developing device in an image forming apparatus such as an electrophotographic printer, a FAX, or a copying machine.

1 is a schematic configuration diagram of a developing device showing Embodiment 1 of the present invention. Print pattern diagram of repeated printing used for evaluation of the present invention Density measurement printing pattern diagram used for evaluation of the present invention The figure which shows the evaluation result of the toner adhesion in each operation environment of Example 1 of this invention. The figure which shows the evaluation result of thin layer formation in each operation environment of Example 1 of this invention The figure which shows the evaluation result of the horizontal stripe in each operation environment of Example 2 of this invention The figure which shows the evaluation result of the toner adhesion in each operation environment of Example 2 of this invention. Schematic block diagram of a developing device showing Embodiment 3 of the present invention Part of the toner layer regulating blade of Example 3 of the present invention Enlarged view showing the evaluation result of fog on the photosensitive drum 1 of Example 3 of the present invention. 1 is a schematic configuration diagram of an image forming apparatus used in an embodiment of the present invention. Schematic configuration diagram of a conventional developing device

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Photosensitive drum, 102 Developing roller, 103 Toner layer thickness control roller, 104 Toner supply roller, 105 Blade, 106 Toner, 107 Toner hopper, 108 Toner collection roller, 1 Photoconductor drum, 2 Developing roller, 3 Toner layer thickness control Roller, 4 Toner supply roller, 5 Toner layer thickness regulating blade, 6 Non-magnetic toner, 7 Toner hopper, 8-11 Power supply, 12 Curved part

Claims (5)

A developing member that develops the electrostatic latent image with a developer on an electrostatic latent image carrier that carries the electrostatic latent image;
A toner layer thickness regulating member that contacts the developing member and rotates in the same direction as the rotating direction of the developing member;
A toner supply member that is installed upstream of the toner layer thickness regulating member in the rotation direction of the developing member and that supplies toner to the developing member in contact with or close to the outer peripheral surface of the developing member;
A toner layer thickness regulating blade that contacts the toner layer thickness regulating member to form a toner layer;
The developing device, wherein the toner layer thickness regulating member has a surface roughness Rz of 6 [μm] or more and 20 [μm] or less.   The developing device according to claim 1, wherein the toner layer thickness regulating member has a surface hardness JISA of 18 degrees or more and 60 degrees or less. A developing member that develops the electrostatic latent image with a developer on an electrostatic latent image carrier that carries the electrostatic latent image;
A toner layer thickness regulating member that contacts the developing member and rotates in the same direction as the rotating direction of the developing member;
A toner supply member that is installed upstream of the toner layer thickness regulating member in the rotation direction of the developing member and that supplies toner to the developing member in contact with or close to the outer peripheral surface of the developing member;
A toner layer thickness regulating blade that contacts the toner layer thickness regulating member to form a toner layer;
The developing device, wherein the toner layer thickness regulating blade has a curved portion, the curved portion is brought into contact with the toner layer thickness regulating member, and a voltage is applied to the toner layer thickness regulating blade.   4. The developing device according to claim 3, wherein | VL | ≦ | VB | is satisfied, where VB is a voltage applied to the toner layer thickness regulating blade and VL is a voltage applied to the toner layer thickness regulating member.   An image forming apparatus equipped with the developing device according to claim 1.

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