JP6066304B2 - Developing device, process unit, and image forming apparatus - Google Patents

Description

  The present invention relates to a developing device used in a copying machine, a printer, and the like, a process unit having the developing device, and an image forming apparatus including these.

  2. Description of the Related Art Conventionally, in an electrophotographic image forming apparatus such as a copying machine or a printer, various types of developing devices are used to develop an electrostatic latent image formed on a latent image carrier such as a drum-shaped photosensitive member. Is used. As such a developing device, a two-component developing type developing device using a developer containing toner and a carrier, and a one-component developing type developing device using only a toner as a developer without using a carrier are known. It has been.

In the developing device as described above, heat is generated when the developer is agitated or conveyed in the developing device (inside the case), and additives for controlling charging property and fluidity are buried in the surface of the toner particles. In some cases, the developer may deteriorate due to toner aggregation. Such deterioration of the developer tends to be promoted as the amount of the developer contained in the developing device and stirred or conveyed increases. If the deteriorated developer is continuously used, the image quality such as density unevenness or white spots is deteriorated. Deterioration occurs.
For this reason, a developer and a developer container such as a toner container are provided separately, and the amount of developer remaining in the developer is detected by the developer detecting means, and the developer consumed by development Conventionally, a developing device that replenishes the inside of the developing device is known. By replenishing the developer in the developing device in this manner, the amount of developer accommodated in the developing device can be reduced, and the occurrence of the above-described problems can be suppressed.

For example, Patent Document 1 describes the configuration of an image forming apparatus provided with a developing device of the following one-component developing system.
A developer carrying member that conveys the carried developer by rotating it to a developing region facing the latent image carrying member, a developer regulating member that regulates the amount of developer carried on the developer carrying member, and a developer carrying member A developer supply body for supplying the developer to the printer, and a developer supply port. Further, a developer detecting means for detecting the amount of developer remaining in the developing device is provided, and at least from the upper portion of the developing device between the developer detecting means and the developer supply port and the developer supply body. A partition member for partitioning below the developer powder surface (hereinafter referred to as developer powder surface) is provided. The partition member partitions the developer replenishing section having the developer detecting means and the developer replenishing port and the developing section having the developer supplying body and the developer carrying body from the upper part of the case to a predetermined height, and below the partition member. The developing unit and the developer replenishing unit are communicated with each other.

  Then, a developer detection means is provided at a position higher than the lowermost part of the partition member on the side surface of the developer replenishment section, which is higher than the lowermost part of the partition member, and the developer consumed by development based on the detection result is developed as needed. Supply from the agent supply port. By constructing the developing device in this way and replenishing the developer, the amount of developer in the developing device can be maintained at an appropriate amount, and the occurrence of image quality deterioration can be suppressed.

  In recent years, in addition to the demand for higher image quality of image forming apparatuses accompanying the widespread use of color-compatible image forming apparatuses, the demand for higher speed has also increased. As the demand for higher speed image forming apparatuses increases, the following problems have surfaced.

In a general and conventional developing device, if the detection accuracy by the developer detecting means is low, the amount of the developer in the developing device is excessively reduced, and the developer may be brought into contact with the developer supply body at a predetermined powder pressure. In some cases, the developer supply member cannot sufficiently supply the developer onto the developer carrier. If the developer cannot be sufficiently supplied in this way, a deviation occurs in the amount of developer carried on the developer carrier in the longitudinal direction of the developer carrier (hereinafter simply referred to as the longitudinal direction), and the image Degradation of image quality such as density deviation and white spots is likely to occur.
For this reason, it is necessary to make the detection accuracy of the developer detection means as high as possible. However, when the speed of the image forming apparatus is increased, the driving speed (rotation) of the developer carrier and the developer supply body is added to the latent image carrier. It is necessary to increase the speed).

  With this increase in speed, the detection accuracy may be significantly reduced depending on the configuration of the developer detection means. That is, the developer supply body of a general developing device is often provided on the developer detection means side of the developer carrying body due to its structure, and at least in the process where the consumption and replenishment of the developer are repeated, A portion thereof is immersed in the developer so as to be exposed from the developer powder surface. When the driving speed of the developer supply body immersed in the developer is increased, the force acting in the direction of pushing up or pushing down the developer powder surface in contact with the developer increases. Against this force, when the developer powder surface in contact with the developer supply body changes in height above a certain level, a restoring force to return to the original height works, and these balances cause the developer powder surface Will vibrate and a wave is generated on the developer powder surface in the developing device. Due to the influence of this wave, the detection accuracy may be significantly lowered depending on the configuration of the developer detection means.

On the other hand, in the developing device of Patent Document 1, although the specific configuration of the developer detection means and the arrangement in the longitudinal direction are not clearly described, the development from FIG. It is considered that the amount of developer in the developing device is managed by detecting the height of the powder surface. Specifically, as the developer detection means, the height of the developer powder surface reaches the lower limit of a predetermined management target at which sufficient developer can be conveyed to the development area via the developer supply body and the developer carrier. It is considered that the developer powder level detecting means for detecting whether or not the toner is used.
Since the developing unit provided with the developer supply body and the developer carrying body and the developer carrying-in path provided with the developer powder level detecting means are partitioned by the partition member, the developer supply body is driven to thereby develop the developer. Even if waves occur on the powder surface, the partition member can reduce the waves on the developer powder surface transmitted to the developer powder surface detection means. Therefore, compared to a developing device having a configuration in which no partition member is provided, the development that gives to the detection accuracy of whether or not the height of the developer powder level by the developer powder level detection means has reached the lower limit of a predetermined management target. It is considered that the influence of driving the agent supply body can be reduced.

However, there are cases where it is not possible to properly detect whether or not the developer powder surface has reached the entire longitudinal direction up to the lower limit of the management target. If it cannot be properly detected in this way, a deviation in the longitudinal direction occurs in the amount of developer on the developer carrying member conveyed to the development area, and image quality deterioration such as an image density deviation and white spots occurs.
This is because at least the developer powder surface of the developer contained in the developing device is partitioned into a developer replenishing portion and a developing portion by a partition member, so that compared to a configuration in which no partition member is provided. This is probably because a large difference in height occurs in the longitudinal direction of the developer supply portion.

  The present invention has been made in view of the above problems, and its object is to reduce the influence of driving the developer supplying body on the developer powder surface detecting means for detecting the height of the developer powder surface, It is an object of the present invention to provide a developing device capable of suppressing the occurrence of image quality deterioration such as density deviation compared to the conventional art.

  In order to achieve the above object, the invention according to claim 1 is the developer carrying that conveys the carried developer by rotating it in the developing area facing the latent image carrier on which the electrostatic latent image is formed. A developer regulating member that regulates the amount of developer carried on the developer carrying body, and a part of the developer regulating member that is exposed from the developer powder surface. The developer is placed on the developer carrying body. In a developing device including a developer supply body to be supplied, provided at least between a developer supply port for supplying a developer into the developer device, the developer supply port, and the developer supply body. A partition member that reaches below the powder surface, and a developer powder level detection unit that detects the height of the developer powder surface on the developer supply port side partitioned by the partition member, and the developer The powder level detection means is arranged in the development area in the longitudinal direction of the developer carrier. The interposed therebetween said developer supply port is characterized in that disposed on the opposite side.

In the present invention, the developer powder level detecting means detects the height of the developer powder surface on the developer supply port side, which is partitioned by a partition member that reaches below the developer powder surface. The influence of waves generated by driving can be reduced, and a decrease in detection accuracy of the developer powder level detection means can be suppressed.
In addition, since the developer powder level detecting means is disposed on the opposite side of the developer supply port across the center of the development region in the longitudinal direction of the developer carrier, in the longitudinal direction of the developer supply portion, The height of the developer powder surface can be detected on the side where the height tends to decrease. Since the detection can be performed in this way, even if image formation is performed with a heavy consumption of the developer, a predetermined management target that can transport a sufficient amount of developer to the development area via the developer supply body and the developer carrier is provided. It is possible to appropriately detect whether or not the developer powder surface has reached the entire length up to the lower limit.
Thus, even when the height of the developer powder surface has a deviation in the longitudinal direction, the longitudinal direction of the developer conveyed to the development area via the developer supply body and the developer carrier is ensured. The developer can be brought into contact with the developer supply body at a predetermined powder pressure over the entire area.
Therefore, it is possible to suppress the occurrence of image quality deterioration such as an image density deviation as compared with the conventional case.

  The present invention reduces the influence of the driving of the developer supply to the developer powder level detecting means for detecting the height of the developer powder level, and development that can suppress the occurrence of image quality deterioration such as an image density deviation compared to the conventional one. An apparatus can be provided.

1 is a schematic configuration diagram illustrating a schematic configuration of a copier according to an embodiment. FIG. 3 is an explanatory diagram of a basic configuration of a black image forming unit. FIG. 2 is an explanatory diagram of a basic configuration of a color image forming unit. 1 is an explanatory diagram of a one-component developing device for color according to Embodiment 1. FIG. 1 is a schematic diagram in a longitudinal direction of a one-component developing device for color according to Embodiment 1. FIG. FIG. 6 is an explanatory diagram of a developing roller according to Embodiment 2. FIG. 6 is an explanatory diagram of a one-component developing device for color according to a third embodiment. FIG. 6 is a schematic diagram in a longitudinal direction of a one-component developing device for color according to a third embodiment.

Hereinafter, as an image forming apparatus to which the present invention is applied, an embodiment of an electrophotographic multifunction machine 300 will be described with reference to a plurality of examples.
First, the configuration and operation of the multifunction machine 300 common to the embodiments will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram illustrating a schematic configuration of a multifunction peripheral 300 according to the present embodiment, FIG. 2 is an explanatory diagram of a basic configuration of an image forming unit 1K for black, and FIG. 3 is an image forming for color. It is explanatory drawing of the fundamental structure of the units 1Y, C, and M.

As shown in FIG. 1, the multifunction machine 300 includes a scanner unit 200 at the top of the apparatus main body 100, and based on image data read by the scanner unit 200 and image data received from an external device such as a personal computer, transfer paper An image is formed on the recording medium P.
Here, since a well-known configuration can be used as the scanner unit 200, a detailed description thereof will be omitted.

In the apparatus main body 100, four image forming units 1Y, 1C, and 1M for forming images of each color of yellow (Y), cyan (C), magenta (M), and black (K) are formed in the image forming unit. , K are provided along the extended surface below the intermediate transfer belt, which is an intermediate transfer member. Here, the color order of Y, C, M, and K is not limited to that of FIG.
The image forming units 1Y, 1C, 1M, and 1K respectively include drum-shaped photoreceptors 2Y, 2C, 2M, and 3K that are latent image carriers, charging means, developing means, and photoreceptors 2Y, 2C, 2M, and 2K. Photosensitive member cleaning means for cleaning the photosensitive member. Each image forming unit 1 is configured to be attachable to and detachable from the apparatus main body 100 as a process unit in which the above-described constituent members (means) are held by a common holding body (not shown). . The arrangement of the image forming units 1 is set so that the rotation axes of the photoconductors 2 are parallel to each other and arranged at a predetermined pitch in the moving direction of the recording medium P such as transfer paper. Yes.

  In each image forming unit 1, first, a predetermined voltage is applied to a charging unit from a power source (not shown) to charge the surface of each opposing photoconductor 2. A laser based on the image data by the optical writing unit 3 is applied to the surface of each photosensitive member 2 charged to a predetermined potential based on image information read by the scanner unit 200 and image information received from an external device such as a personal computer. Light is scanned and electrostatic latent images are written respectively. When the surface of each photoconductor 2 carrying an electrostatic latent image reaches the developing unit, the surface of the photoconductor 2 is electrostatically charged by a developing roller that is a developer carrying member of the developing unit arranged opposite to each photoconductor 2. Toner is supplied to the latent image to form a toner image.

  The above operation is similarly performed at a predetermined timing in all the image forming units 1Y, 1C, 1M, and 1K, and toner images of a predetermined color are formed on the surfaces of the photoreceptors 2Y, 2C, 2M, and 2K, respectively. Is done. The image forming units 1Y, 1C, 1M, and 1K sequentially transfer the toner images on the photosensitive members 2 onto the intermediate transfer belt 4 at the primary transfer position at a predetermined image forming operation timing. The primary transfer of the toner image is performed on the toner on each photoconductor 2 from a power supply (not shown) to primary transfer rollers 17Y, 17C, 17M, and 17K that are arranged to face each photoconductor 2 with the intermediate transfer belt 4 interposed therebetween. This is performed by applying a primary transfer bias (voltage) having a polarity opposite to that.

  The recording medium P is conveyed from any of the paper feed cassettes 10 a and 10 b or the manual feed tray 10 c and stops once when it reaches the registration roller pair 16. Then, the sheet is conveyed in accordance with the image forming operation timing described above.

  Each image forming unit 1 is provided with a lubricant applying means on the surface of the photoreceptor 2K only in the image forming unit 1K arranged at the most downstream in the moving direction of the intermediate transfer belt 4 endlessly moving counterclockwise in FIG. Yes. The other image forming units 1Y, 1C, and 1M are not provided with a lubricant applying unit for each photoconductor 2.

Below the image forming units 1Y, 1C, 1M, and 1K, a light source, a polygon mirror, an f-θ lens, a reflection mirror, and the like are provided, and lasers are applied to the surfaces of the photoreceptors 2Y, 2C, 2M, and 2K based on image data. An optical writing unit 3 for irradiating while scanning light is arranged.
Further, an intermediate transfer unit 5 having an intermediate transfer belt 4 that conveys the toner images of the image forming units 1 so as to be superimposed and transferred is disposed above. A secondary transfer roller 7 is provided on the right side of the intermediate transfer unit 5 in FIG.
The secondary transfer roller 7 is in contact with the intermediate transfer belt 4 and opposed to the intermediate transfer unit 5 to form a secondary transfer nip portion.

The four color toner images superimposed on the intermediate transfer belt 4 are transferred from the registration roller pair 16 at the secondary transfer nip portion formed by the secondary transfer roller 7 and the intermediate transfer belt 4 in accordance with the image forming operation timing. Secondary transfer is performed on the conveyed recording medium P. The secondary transfer of the toner image is performed by applying a voltage having a polarity opposite to that of the toner on the intermediate transfer belt 4 from a power source (not shown) to the secondary transfer roller 7.
A belt cleaning device 6 composed of a brush roller and a cleaning blade is disposed on the outer peripheral surface of the intermediate transfer belt 4 so as to come into contact therewith. By this belt cleaning device 6, toner remaining without being secondarily transferred at the secondary transfer nip portion and foreign matters adhering to the intermediate transfer belt 4 are removed.

A belt fixing type fixing unit 8 is provided above the intermediate transfer unit 5.
The fixing unit 8 includes a fixing roller over which a fixing belt is stretched, and a pressure roller disposed so as to face the fixing roller via the fixing belt.
When the recording medium P on which the toner image is secondarily transferred at the secondary transfer nip portion passes through the fixing nip portion between the fixing roller and the pressure roller formed via the fixing belt, heat and pressure are applied. The received and secondarily transferred toner image is fixed on the recording medium P to form an image.
The recording medium P on which an image has been formed is transported and stacked on a stacking tray formed on the upper portion of the apparatus main body 100, that is, outside the apparatus, by each transport roller.

Further, as described above, the image forming apparatus is provided with the paper feed cassettes 10a and 10b on which the recording medium P is placed. Further, in the drawing of the apparatus main body 100, a manual feed tray 10c that feeds paper manually from the side surface on the right hand side is provided.
In addition, toner replenishing containers 11Y, 11C, 11M, and 11K are provided, and a waste toner bottle, a power supply unit, each unit, and a control unit that controls each device (not shown) are also provided.
Next, a basic configuration of each image forming unit 1 of the present embodiment will be described.

First, the black (black) image forming unit 1K will be described.
As shown in FIG. 2, the black image forming unit 1 </ b> K is a unit including a lubricant applying unit. The lubricant applying means includes a lubricant applying brush 38 and a solid lubricant 39. By applying pressure to the lubricant application brush 38 with a pressure spring (not shown) against the solid lubricant 39, a necessary amount of lubricant is scraped off the lubricant application brush 38 and applied to the surface of the photoreceptor 2K. The lubricant applied to the surface of the photoreceptor 2 </ b> K by the lubricant applying brush 38 which is a lubricant applying means is thinned by the lubricant applying blade 34.

  In the same case as the lubricant applying unit, a photoconductor cleaning blade 36 as a photoconductor cleaning unit and a non-contact charging roller 37 as a charging unit are arranged. Then, a charging bias obtained by superimposing an alternating current (AC) voltage on a direct current (DC) voltage is applied to the charging roller 37 to uniformly charge the photosensitive member 2K to a predetermined potential.

As the developing means, a two-component developing device 31 is arranged. The two-component developing device 31 accommodates a developer in which carrier particles made of ferrite coated therein and black toner that is a colored powder are mixed, and is stirred by an agitating and conveying screw 35 in the axial direction (direction perpendicular to the figure). ) Has been moved to circulate. Here, the toner is charged mainly by contacting with the carrier.
The developer sleeve 32, which is a developer carrying member including a magnet roller (not shown), bears the developer on its surface by a magnetic force, and faces the photoreceptor 2K as the surface moves due to rotation. Transport toward the development area.

The developing sleeve 32 is in contact with a regulating blade 33 that is a developer regulating member that regulates the amount of toner carried on the surface of the developing sleeve 32, and the electrostatic latent image on the photoreceptor 2 </ b> K is formed with the toner that has passed through the regulating blade 33. develop.
In addition, a toner density sensor (not shown) is provided inside the two-component developing device 31, and in response to the output of the toner density sensor, the toner supply device 11K uses a black toner supply device from the toner supply container 11K. Toner is replenished.

  Like the two-component developing device 31, a two-component developing type developing device is relatively high in durability and has little fluctuation with respect to stability over time, mixing of a lubricant, etc., but a plurality of stirring and conveying screws are used. The apparatus becomes large and expensive because it is necessary to have it. Therefore, in the present embodiment, the two-component developing type two-component developing device 31 is mounted only in the image forming unit 1K that forms the most frequently used black image, and a lubricant is applied to the photosensitive member. 2K deterioration is reduced, and the life of the apparatus main body 100 is extended.

The lubricant applied to the surface of the photoreceptor 2K is transferred to the intermediate transfer belt 4 when the photoreceptor 2K contacts the intermediate transfer belt 4 at the primary transfer position and a primary transfer bias is applied. Therefore, the lubricant is always applied to the surface of the photoconductor 2K as the photoconductor 2K rotates.
Here, the lubricant transferred onto the intermediate transfer belt 4 is transferred to the contacted material during operation. At the primary transfer position with the image forming unit 1K, the intermediate transfer belt 4 in contact with the surface of the photoreceptor 2K coated with the lubricant contacts the surfaces of the photoreceptors 2Y, 2C, 2M of other colors with rotation. The lubricant is mixed into the image forming units 1Y, 1C, 1M of other colors.

Next, a basic configuration of the color image forming units 1Y, 1C, and 1M will be described.
Here, the color image forming units 1Y, 1C, and 1M are different from the black image forming unit 1K in the following two points. The point relating to the fact that no lubricant applying means is provided, and the point relating to the provision of the one-component developing devices 41Y, 41C, 41M which are developing devices of the one-component developing system as the developing means. Each color image forming unit 1 is different in the color of the toner to be used, and the basic configuration is almost the same. Therefore, in the following description, the symbol Y indicating the color is used unless otherwise specified. , C and M will be omitted.

  As shown in FIG. 3, each of the color image forming units 1 abuts against the photoreceptor 2 as a latent image carrier on which an electrostatic latent image is formed, and cleans the surface of the photoreceptor. And a charging roller 47 which is a non-contact charging roller which is a charging means. The charging roller 47 is non-contact in order to avoid contamination of the surface of the charging roller 47 by the lubricant that has passed around from the image forming unit 1K via the intermediate transfer belt 4, and a direct current (DC) voltage is used during uniform charging. A primary transfer bias in which an alternating current (AC) voltage is superimposed on is applied. As a developing means, a one-component developing device 41 which is a non-contact developing device of a one-component developing system is provided.

In FIG. 3, the one-component developing device 41 includes a developing roller 42 that is a developer carrying member that conveys the carried developer by rotating it in a developing region facing the photosensitive member 2 that rotates clockwise. Then, it rotates counterclockwise in the forward direction with respect to the surface of the photoreceptor 2 at, for example, twice the linear velocity.
Also provided is a thin layer blade 43 that is a developer regulating member that regulates the developer amount (toner amount) carried on the developing roller 42 by abutting and regulating it. Further, a supply roller 44 that is a developer supply body that supplies toner to the developing roller 42 is provided, and is in a counter direction at a position in contact with the developing roller 42, that is, a position where the supply roller 44 and the developing roller 42 abut. It rotates counterclockwise (in the reverse direction).

  In addition, since only the toner that forms the developer is contained in the one-component developing device 41, the stirring and conveying screw 35 is not required unlike the two-component developing device 31 for black described above, and the inside of the one-component developing device 41 A paddle 45 that is a stirring member is provided for circulation of the toner. Since the one-component developing device 41 has such a simple configuration, it can be reduced in size and cost.

  In the one-component developing device 41, the toner supplied onto the surface of the developing roller 42 at the developer supply position where the supply roller 44 and the developing roller 42 are in contact with each other is transferred from the developer supplying position to the surface of the photoreceptor 2. Is conveyed toward the developing area opposite to. Then, a thin layer of toner is formed on the developing roller 42 after passing through the thin layer blade 43 in the middle of being conveyed toward the developing region. The formed thin layer of toner is further conveyed to the development area, and adheres to the electrostatic latent image portion on the surface of the photosensitive member 2 by the developing electric field between the developing roller 42 and the electrostatic latent image on the photosensitive member 2. As a result, the electrostatic latent image is developed. A neutralization seal, which is a developer neutralization member (not shown), is provided at a location where the toner that is not used for development in the development area and remains on the development roller 42 returns to the one-component development device 41 again. 42 is provided in contact with 42 and is sealed so that the toner does not leak outside.

  Here, in general, when the developer is stirred or conveyed in the developing device (in the case), heat is generated, an additive for controlling charging property or fluidity is buried in the surface of the toner particle, The developer may deteriorate due to aggregation. Such deterioration of the developer tends to be promoted as the amount of the developer contained in the developing device and stirred or conveyed increases. If the deteriorated developer is continuously used, the image quality such as density unevenness or white spots is deteriorated. Deterioration occurs.

On the other hand, in the one-component developing device 41 of the present embodiment, the one-component developing device 41 and the toner supply container 11 that is a developer container are provided separately.
Although not described in detail later, a developer powder level detecting means (not shown) for detecting the amount of developer remaining in the one-component developing device 41 is also provided. This developer powder level detecting means is used to develop a developer powder up to a lower limit of a predetermined management target capable of transporting a sufficient amount of developer via the supply roller 44 and the development roller 42 to the development area where the development roller 42 faces the photoreceptor 2. Detects whether the height of the surface has been reached. Based on the detection result, the developer consumed by the development is replenished from the toner replenishing device 11 to the one-component developing device 41 from the toner replenishing device (not shown) as needed. The amount of developer to be stored can be reduced, and the occurrence of image quality deterioration can be suppressed.
Further, in order to reduce the amount of developer accommodated in the one-component developing device 41 as described above, a part of the supply roller 44 is exposed from the powder surface of the developer (hereinafter referred to as developer powder surface). The developer is supplied to the developing roller 42 that is disposed in contact therewith.

Here, since the non-contact developing device of the one-component developing system is non-contact like the one-component developing device 41 of the present embodiment, the lubricant is not sufficiently applied, and the latent image is not protected by the lubricant. The surface of the photoconductor, which is an image carrier, is not damaged, which is advantageous for improving the durability of the photoconductor. Furthermore, it is possible to avoid a minute amount of lubricant transferred from the intermediate transfer belt or the like as an intermediate transfer member from adhering to the surface of the photosensitive member or the like in the one-component non-contact developing device.
However, in the one-component non-contact developing device such as the one-component developing device 41 of the present embodiment, the surface of the developing roller or the like that is a developer carrying member serves as a counter electrode during development, and the surface is stained by an image. Deteriorating the stability of Further, the developing roller 42 provided in the one-component developing device 41 of the present embodiment has a metal outer peripheral surface subjected to a blasting process, and a metal thin layer blade 43 is brought into contact with each other. As a result, the durability is inferior to that of a two-component developing system.

  Based on such characteristics, in the multifunction machine 300 of the present embodiment, the color image forming unit 1 has the configuration shown in FIG. 3 and uses the one-component developing device 41 only during color printing. Miniaturization and cost reduction are realized without sacrificing user convenience.

However, as described above, the supply roller 44 included in the one-component developing device 41 of the present embodiment is disposed so that a part thereof is exposed from the developer powder surface. That is, the supply roller 44 of this embodiment is immersed in the developer so that a part thereof is exposed from the developer powder surface.
Thus, when the driving speed of the supply roller 44 dipped in the developer in the one-component developing device 41 and whose surface is blasted is increased, the developer in contact with the counterclockwise rotation is increased. The force acting in the direction of pushing down the powder surface increases. In response to this force, the developer powder surface in contact with the supply roller 44 has a restoring force to return to the original height when the height changes more than a certain level. A single vibration occurs, and the developer powder surface in the one-component developing device 41 vibrates to generate a wave. Depending on the configuration of the developer powder level detection unit, the detection accuracy may be significantly reduced by the influence of the wave generated by driving the supply roller 44 being propagated as noise to the developer powder level detection unit.

  In addition, when image formation is performed where consumption of the developer is severe, it is impossible to properly detect whether or not the developer powder level has reached the entire length in the longitudinal direction up to the lower limit of the above-described management target, and the development is performed on the supply roller 44. In some cases, the agent could not be contacted at a predetermined powder pressure. If the developer cannot be brought into contact with a predetermined powder pressure in this way, image quality deterioration such as an image density deviation occurs. In other words, when image formation that consumes a large amount of developer is performed, it is not possible to properly detect whether or not the height of the developer powder surface has reached the lower limit of the above-described management target. In some cases, image quality degradation occurred.

  Next, the one-component development included in each of the color image forming units 1Y, 1C, and 1M that can suppress the occurrence of image quality deterioration such as an image density deviation, which is a characteristic part of the MFP 300 of the present embodiment. The devices 41Y, 41C, 41M will be described in more detail by giving a plurality of examples. Here, in the following description of each embodiment, a configuration and operation similar to the basic configuration described above, and its operation and effect will be omitted as appropriate. Further, as described above, each color image forming unit 1 is different in the color of the toner to be used and the basic configuration is almost the same. Therefore, unless otherwise specified, the symbol Y indicating the color is used. , C and M will be omitted. In addition, devices and members that perform the same function will be described using the same reference numerals.

Example 1
First, Example 1 of the one-component developing device 41 included in the color image forming unit 1 of this embodiment will be described with reference to the drawings.
4A and 4B are explanatory diagrams of the color one-component developing device 41 according to this embodiment, in which FIG. 4A is an explanatory diagram of a cross section perpendicular to the rotation axis of the developing roller 42, and FIG. 4B is a one-component developing device. 41 is an explanatory diagram of a paddle 45 included in 41. FIG. FIG. 5 is a schematic diagram in the longitudinal direction of the one-component developing device 41 for color according to the present embodiment.

As shown in FIG. 4A, in the one-component developing device 41 of this embodiment, as described above, the metal developing roller 42 is used as the developer carrying member. On the outer peripheral surface of the developing roller 42, the developer (toner) supplied from the supply roller 44 at the toner supply position and thinned by the thin blade 43 is stably conveyed to the developing area facing the photoreceptor 2. In order to achieve this, the surface of the metal is blasted to give it a roughness.
Further, at least the height of the developer powder stored in the one-component developing device 41 between the developer supply port 53 that is a developer supply port for supplying the developer into the one-component developing device 41 and the supply roller 44. A partition member 51 that is a partition member reaching the lower limit 61 is provided.

  In order to appropriately manage the amount of developer in the one-component developing device 41, a developer powder level detecting unit that detects the height of the developer powder surface on the developer supply port 53 side partitioned by the partition member 51 is used. A developer powder level detecting means 52 is provided. Specifically, as shown in FIG. 4, when the partition member 51, the developer powder level detecting means 52, and the developer supply port 53 are projected on a cross section perpendicular to the longitudinal direction of the developing roller 42, the partition is separated. The member 51 is arranged closer to the developer supply port 53 than the member 51.

  In the one-component developing device 41, a paddle 45 that is an agitator for agitating the contained developer is disposed below the partition member 51, the supply roller 44, and the developer supply port 53, and is driven to rotate. It is configured to do. As shown in FIG. 4B, the paddle 45 has a structure in which two PET mylars 45b having a thickness of 0.05 to 0.1 mm are attached to a metal or resin paddle shaft 45a. A flat plate shape or comb-tooth shape can be used. When using the comb tooth shape, the distance and speed for uniformly diffusing the developer in the longitudinal direction of the one-component developing device 41 are made larger than those of the flat plate shape by optimizing the comb tooth spacing and tooth width. it can.

Here, the developer powder level detection means 52 is disposed closer to the developer supply port 53 than the partition member 51, and the lower limit of the range for detecting the developer powder level height (not shown) is the developer powder level height. Is disposed between the lower limit 61 and the developer powder surface height upper limit 61 ′. Further, an infrared transmission type photo interrupter is used as the developer powder level detecting means 52, the transmission is blocked by the presence of the developer in the detection area, the presence / absence of the developer is determined, and the height of the developer powder level is the above It is detected whether or not it is between the lower limit 61 and the developer powder surface height upper limit 61 ′.
Further, the lower limit of the range in which the developer powder level is detected by the developer powder level detecting means 52, that is, the lower limit of the range in which the developer powder level is detected is the lowest in the height direction of the supply roller 44. It is comprised so that it may become above.
Then, based on the height of the developer powder surface detected by the developer powder surface detecting means 52, it is detected whether the developer powder surface has reached the lower limit 61, and at least the developing roller 44 is developed. The developer is replenished so as to maintain the height at which the powder surface touches.

  The partition member 51 partitions the developing unit having the developing roller 42 and the supply roller 44 and the developer replenishing unit having the developer powder level detecting unit 52 and the developer replenishing port 53 from the upper part of the case to a predetermined height. Yes. The developing unit and the developer replenishing unit are communicated with each other in a region below the partition member 51 in which the paddle 45 is disposed.

  The supply roller 44 is covered with a foam material having a structure having pores (cells) on its surface, and takes in the toner by adhering it efficiently, and by the concentration of pressure at the contact portion with the developing roller 42. Prevents deterioration. In addition, this foaming material is set to an electrical resistance value of 103 to 1014 [Ω]. A supply bias is applied to the supply roller 44 to assist the operation of pressing the pre-charged toner against the development roller 42 at the contact portion with the development roller 42.

  Further, a thin layer blade 43 as a developer regulating member is disposed so as to come into contact with the surface of the developing roller 42 on the downstream side in the surface movement direction of the developing roller 42 from the position where the supply roller 44 abuts. The toner supplied from the supply roller 44 to the surface of the developing roller 42 is conveyed to a position where the thin layer blade 43 contacts with the rotation of the developing roller 42. This thin layer blade 43 has a free end abutted against the surface of the developing roller 42 with a pressing force of 10 to 100 [N / m]. By letting it pass, the toner layer is thinned and the toner is charged by frictional charging.

In addition, the developing electric field when developing the electrostatic latent image has an alternating current (AC) voltage in which the voltage at which the toner is directed to the photosensitive member 2 and the voltage returning to the developing roller 42 are alternately repeated. Use development bias.
In this example, a rectangular wave with f = 500 to 10,000 Hz, Vpp = 500 to 3000, and Duty = 50% was used.
The toner that has not contributed to the development after the development bias is applied is further conveyed by the rotation of the development roller 42 that is a developer carrying member, and is again formed in the toner supply chamber formed in the case of the one-component development device 41. Returned to and used repeatedly.

  Further, as described above, the developing roller 42 is not in contact with the photosensitive member 2 and rotates in the counterclockwise direction in FIG. 4A. For this reason, in the developing region where the developing roller 42 and the photosensitive member 2 face each other, the surface moving direction of the developing roller 42 and the surface moving direction of the photosensitive member 2 are the same direction. The toner layer thinned on the developing roller 42 is transported to the developing area as the developing roller 42 rotates, and is formed by the developing bias applied to the developing roller 42 and the electrostatic latent image on the photoreceptor 2. It moves to the surface of the photoreceptor 2 in response to the developing electric field, and the electrostatic latent image on the photoreceptor 2 is developed.

As described above, in the one-component developing device 41 of the present embodiment, the height of the developer powder surface on the developer supply port 53 side, which is partitioned by the partition member 51 that reaches below the developer powder surface, is set as the developer powder. It is detected by the surface detection means 52. Therefore, it is possible to reduce the influence of the waves generated by driving the supply roller 44, and to suppress a decrease in detection accuracy of the developer powder level detection means 52.
However, if image formation that consumes a lot of developer is continuously performed, it is impossible to properly detect whether or not the developer powder level has reached the entire length in the longitudinal direction up to the lower limit of the management target described above. In some cases, image quality degradation occurred.
This is because at least the developer powder surface of the developer that is powder stored in the one-component developing device 41 is partitioned by the partition member 51 into the developer replenishment section and the development section. This is considered to be because a large level difference occurs in the longitudinal direction of the developer replenishment portion as compared with the configuration without the above.

  Therefore, in the one-component developing device 41 of this embodiment, as shown in FIG. 5, the developer replenishing port 53 is positioned in the longitudinal direction of the one-component developing device 41, which is the longitudinal direction of the developing roller 42, on the right-hand side in FIG. It arrange | positioned in the edge part vicinity. The developer powder level detection means 52 is arranged on the opposite side of the developer supply port 53 across the center of the development region in the longitudinal direction of the one-component developing device 41 (developing roller 42). That is, the developer powder level detecting means 52 is passed through the center line in the longitudinal direction of the developing region (developer regulating region) where the developer on the developing roller 42 is transported after being thinned by the thin layer blade 43. 57 in the region opposite to the developer supply port 53. At this time, the arrangement position of the developer powder level detecting means 52 may be either inside or outside the developing area in the longitudinal direction of the one-component developing device 41.

  As described above, since the developer powder level detecting means 52 is provided on the opposite side of the developer supply port 53 across the center of the development region, the height of the developer supply portion provided with the developer supply port 53 is increased in the longitudinal direction. Therefore, the height of the developer powder surface can be detected on the side where the height is likely to be low. Since the detection can be performed in this manner, the lower limit 61 of the management target capable of transporting sufficient developer to the development area via the developer supply body and the developer carrying body even when the image formation with heavy developer consumption is performed. Until now, it is possible to appropriately detect whether or not the developer powder surface has reached the entire longitudinal direction. That is, with respect to the longitudinal direction of the one-component developing device 41, it is possible to suppress the detection of the developer powder level even when the developer powder surface does not partially contact the supply roller 44.

Thus, even if the height of the developer powder surface has a deviation in the longitudinal direction, the area in the longitudinal direction of the developer conveyed to the developing area via the supply roller 44 and the developing roller 42 can be detected. The developer can be brought into contact with the supply roller 44 with a predetermined powder pressure over the entire area. Therefore, it is possible to suppress the occurrence of image quality deterioration such as an image density deviation as compared with the conventional case.
Therefore, one-component development that can reduce the influence of driving of the supply roller 44 to the developer powder level detecting means 52 that detects the height of the developer powder level and can suppress the occurrence of image quality deterioration such as an image density deviation compared to the conventional one. A device 41 can be provided.

In addition, as described above, the lower limit 61 of the range for detecting the height of the developer powder surface by the developer powder surface detection means 52 is configured to be higher than the lowermost portion of the supply roller 44 in the height direction. ing.
With this configuration, the height of the developer powder surface can be replenished with the developer so as to be in contact with the supply roller 44, and the developer can be always supplied to the supply roller 44. Even if the developer is consumed, a thin developer layer can be formed again after one revolution.
Therefore, the developer can be stably supplied to the developing roller 42.

(Example 2)
Next, Example 2 of the one-component developing device 41 provided in each of the color image forming units 1Y, 1C, and 1M of this embodiment will be described with reference to the drawings.
6A and 6B are explanatory views of the developing roller 42 according to the present embodiment, where FIG. 6A is a plan explanatory view of the developing roller 42, and FIG. 6B is an enlarged explanatory view of the concavo-convex portion of the developing roller 42 as viewed from above. It is.

  Here, the one-component developing device 41 of the present embodiment and the one-component developing device of the first embodiment described above are arranged on the surface of the developing roller 42 that is a developer carrier provided in the one-component developing device 41 of the present embodiment. The only difference is that it has irregularities arranged regularly. That is, the only difference is that a mesh-like uneven pattern is formed on the outer peripheral surface of the developing roller 42 provided in the one-component developing device 41 of the present embodiment. Therefore, in the following description, differences from the first embodiment will be described in detail, and the same points as in the first embodiment will be omitted as appropriate.

In Example 1 described above, a metal roller whose outer peripheral surface (surface) has been subjected to blasting is used as the developing roller as the developer carrying member.
However, when such a developing roller is used, the pressure between the developing roller and the thin layer blade that is the developer regulating member is directly applied to the toner that is the developer. There is a case where the decrease of the occurrence occurs early. Further, there is a problem that the deteriorated toner is fixed to a thin layer blade or the like, and noise is generated in the image.
Conventionally, there has been a demand for image stability and high durability in a one-component developing type developing apparatus.

Therefore, the one-component developing device 41 of the present embodiment is a one-component developing device that is a developing device of the one-component developing system so that the durability can be improved with respect to the developing device of the first embodiment and the conventional one-component developing method. Forty-one developing roller 42 is configured as follows.
Specifically, the uneven region 42a in which regular uneven portions are formed is arranged in a range including the developer restricting region on the outer peripheral surface of the developing roller 42 shown by hatching in FIG. A range in the vicinity of both end portions that deviates from the uneven region 42a on the outer peripheral surface of the developing roller 42 was defined as a cylindrical region 42b in which no uneven portion was formed. Note that shafts 42c are provided at both ends of the developing roller 42, respectively.

Then, as a concavo-convex portion in the concavo-convex region 42 a on the outer peripheral surface of the developing roller 42, a mesh-like concavo-convex pattern groove as shown in FIG.
In the example shown in FIGS. 6A and 6B, each groove is continuously formed in a spiral shape inclined at a predetermined angle (45 ° in the illustrated example) with respect to the axial direction, and a predetermined number having regularity. The first inclined grooves, and the first inclined grooves and a predetermined number of second inclined grooves continuous in a spiral shape with the inclination inclined in the opposite direction. Here, the predetermined angle is 45 ° in the example illustrated in FIGS. 6A and 6B, but is not limited thereto.

Each of the first inclined groove and the second inclined groove has a predetermined inclination angle set individually with respect to the axial direction of the developing roller 42 and has a predetermined period in the axial direction of the developing roller 42. It is formed periodically so as to form the width W.
Here, each inclination angle and period width W of the first inclined groove and the second inclined groove can be made different from each other. Further, it is desirable that the width T in the axial direction of the developing roller 42 of the convex portion is formed to be not less than ½ of W.

The developing roller 42 includes a base material and a surface layer formed on the outer peripheral surface of the base material.
The base material is made of a metal material sleeve such as an aluminum-based material such as 5056 aluminum alloy or 6063 aluminum alloy or an iron-based material such as STKM.
The uneven portion formed on the outer peripheral surface of the base material of the developing roller 42 is formed by rolling. A conventionally known processing method can be employed as the processing method for the base material. Therefore, description of this processing method is omitted.

  By configuring the developing roller 42 as described above, the thin layer blade 43 that is the developer regulating member does not apply excessive pressure to the toner that is the developer, and the toner supplied to the surface of the developing roller 42 is a thin layer. Therefore, the stability of the image and high durability can be achieved.

However, the developing roller having the concavo-convex portion like the developing roller 42 of the present embodiment described above has an advantageous configuration with respect to the deterioration of the developer in forming the developer thin layer, but the developing roller 42 having the concavo-convex portion. However, the developer does not deteriorate at all.
For example, when a new developer is replenished in a one-component developing type developing device, if the developer is taken into the developer thin layer with insufficient stirring, the background stain will be worsened. Also, if the developer powder level does not reach the supply roller, or if the developer powder pressure on the supply roller is too low, the developer will be exposed to the development roller during image formation (mode) where consumption of the developer is severe. Insufficient developer supply capability. Then, it is also known that a phenomenon that an output image becomes thin (deterioration of solid followability) occurs. If the height of the developer powder surface in contact with the supply roller has a deviation in the longitudinal direction of the developing roller 42, the above phenomenon may appear as a density left-right deviation within the same page. is there.

Even when the supply roller consumes the largest amount of developer, it is necessary to supply a sufficient amount of developer to re-form the original thin layer on the development roller. It has been experimentally found that a travel speed of 60% or more of the speed is necessary. When such high speed running is performed, the fluctuation of the developer powder surface height becomes large, and it becomes difficult to detect the developer powder surface height.
In particular, in the configuration having the concavo-convex portion on the outer peripheral surface like the developing roller 42 of the present embodiment, the developer powder surface that contacts the developing roller 42 rather than the supply roller of the first embodiment blasted on the surface thereof. There is a possibility that the fluctuation (amplitude) of the height becomes large. Although the deterioration of the developer can be suppressed when it becomes large in this way, the image quality deterioration such as an image density deviation is caused by the influence of the driving roller 44 to the developer powder surface detecting means 52 that detects the height of the developer powder surface. May occur.
Therefore, the configuration of the partition member 51, the developer powder level detecting means 52, the developer supply port 53, and the like of the first embodiment described with reference to FIGS. 4 and 5 is also applied to the one-component developing device 41 of the present embodiment. Thus, the influence of the driving of the supply roller 44 is reduced, and the occurrence of image quality deterioration such as an image density deviation is suppressed.

Similarly to the first embodiment, the supply roller 44 is covered with a foam material having a structure having pores (cells) on the surface thereof, and takes in the toner while adhering it efficiently, and is in contact with the developing roller 42. The toner is prevented from deteriorating due to pressure concentration in the printer. In addition, this foaming material is set to an electrical resistance value of 103 to 1014 [Ω]. Similarly to the first embodiment, a supply bias is applied to the supply roller 44 to assist the operation of pressing the pre-charged toner against the development roller 42 at the contact portion with the development roller 42.
The thin layer blade 43 has a free end brought into contact with the surface of the developing roller 42 with a pressing force of 10 to 100 [N / m]. By allowing the toner to pass through, the toner layer is thinned in the same manner as in the first embodiment, and charge is applied to the toner.

Further, as in the first embodiment, the voltage at which the toner is directed toward the photosensitive member 2 and the voltage at which the toner returns to the developing roller 42 are alternately repeated in the developing electric field when developing the electrostatic latent image. Use a developing bias with a constant alternating current (AC) voltage.
Also in this example, a rectangular wave with f = 500 to 10,000 Hz, Vpp = 500 to 3000, and Duty = 50% was used.
The toner that has not contributed to the development after the development bias is applied is further conveyed by the rotation of the development roller 42 that is a developer carrying member, and is again formed in the toner supply chamber formed in the case of the one-component development device 41. Returned to and used repeatedly.

By using the above-described one-component developing device 41 of the present embodiment, the pressure applied to the developer (toner) can be reduced at the portion where the developing roller 42 having the uneven portion on the outer peripheral surface passes through the thin layer blade 43. Further, since the developer enters a recess formed on the outer peripheral surface (surface layer) of the developing roller 42 and passes through the thin layer blade 43, the amount of the developer passing through the thin layer blade 43 is stabilized, and the image density is stabilized. Is possible.
Therefore, in addition to the effects described in the first embodiment, it is possible to suppress the deterioration of the developer accommodated in the one-component developing device 41 and to stabilize the image density.

(Example 3)
Next, Example 3 of the one-component developing device 41 provided in each of the color image forming units 1Y, 1C, and 1M of this embodiment will be described with reference to the drawings.
7A and 7B are explanatory views of the one-component developing device 41 for color according to the present embodiment, where FIG. 7A is an explanatory view of a cross section perpendicular to the rotation axis of the developing roller 42, and FIG. 7B is a one-component developing device. 41 is an explanatory diagram of a paddle 45 included in 41. FIG. FIG. 8 is a schematic diagram in the longitudinal direction of the one-component developing device 41 for color according to the present embodiment.

  Here, in the one-component developing device 41 of the present embodiment and the one-component developing devices of the first and second embodiments described above, only the point relating to the provision of a plurality of stirrers in the one-component developing device 41 of the present embodiment. Different. Therefore, in the following description, points different from the first and second embodiments will be described in detail, and the same points as the first and second embodiments will be omitted as appropriate.

In the one-component developing device 41 of this embodiment, unlike the one-component developing devices of Embodiments 1 and 2 described with reference to FIG. 4, a plurality of stirrers that stir the developer in the one-component developing device 41 are provided. .
As shown in FIG. 7, the same paddle 45 as in the first and second embodiments is used as the first agitator, and is arranged below the partition member 51, the supply roller 44, and the developer supply port 53, and is driven to rotate. doing. In addition, as shown in FIG. 7, the spiral screw-shaped stirring and conveying screw 54 is used as the second stirring body, and closer to the developer supply port 53 than both the partition member 51 and the paddle 45 that is the first stirring body, In addition, the developer powder surface height lower limit 61 is arranged at a height at which a part of the developer powder surface height is immersed. Therefore, the stirring region (range) of the paddle 45 exists below the stirring and conveying screw 54 that is the second stirring body.

  More specifically, at least a part of each developer such as toner in the region below the partition member 51, the region below the supply roller 44, and the region below the developer supply port 53 is stirred. A paddle 45 was provided. Further, an agitating / conveying screw 54 that is disposed closer to the developer supply port 53 than the partition member 51 and the paddle 45 and agitates the developer is also provided. The agitating / conveying screw 54 has a conveying ability to convey the developer in the longitudinal direction of the developing roller 42, and the paddle 45 agitates at least a part of the developer in the region directly below the agitating / conveying screw 54. Configured.

As described above, the agitating / conveying screw 54 has a spiral screw shape, and is driven to rotate so that the agitating / conveying screw 54 faces the developer powder level detecting means 52 from the developer supply port 53 as indicated by an arrow A in FIG. The developer is conveyed in the longitudinal direction of the component developing device 41 (developing roller 42). The agitating / conveying screw 54 is configured to have a function of conveying the developer only in one direction in the longitudinal direction of the one-component developing device 41 according to the rotation direction.
The rotational speed of the paddle 45 and the stirring and conveying screw 54, the PET mylar thickness and shape of the paddle 45, and the pitch of the helical screw of the stirring and conveying screw 54 are between the lower limit 61 and the upper limit 61 ′ of the developer powder surface height. Further, the developer powder surface is optimized so as not to cause a deviation in the longitudinal direction.

By configuring the one-component developing device 41 in this way, a new developer replenished (entered) from the developer replenishing port 53 is conveyed along the longitudinal direction of the one-component developing device 41, and the partition member 51. Thus, the developer can be supplied uniformly in the developer supply section partitioned by.
By replenishing in this manner, the developer can be agitated and mixed in the cross section perpendicular to the rotation axis of the developing roller 42 by the rotational drive of the paddle 45, and the one-component developing device 41 by the rotational drive of the agitating and conveying screw 54. The unevenness of the developer in the longitudinal direction, that is, the unevenness of the developer powder surface is leveled.
Accordingly, the newly replenished developer is uniformly diffused in the longitudinal direction by the agitating and conveying screw 54, and sufficiently agitated by the paddle 45 before reaching the surface of the supply roller 44, and the developer powder surface height is set to the developing roller. It is possible to make uniform over the entire development area of 42.
Therefore, it is possible to suppress the occurrence of image quality deterioration such as an image density deviation in the longitudinal direction of the one-component developing device 41, compared to the first and second embodiments.

In the above-described embodiment, the example in which the present invention is applied to the one-component developing device 41 that is a non-contact developing device of the one-component developing system has been described. However, the present invention is limited to such a configuration. is not. For example, the present invention can be applied to a one-component developing contact type developing device.
In addition, a means for supplying toner and carrier separately is provided, and toner is supplied based on the detection result of the toner density detecting means, and the developer amount is detected when the carrier is supplied at a predetermined timing. The present invention can also be applied to a two-component developing device configured to detect by means.

  Further, an example in which the present invention is applied to a one-component developing device 41 configured as a one-component developing type non-contact developing device in which a metal thin roller blade 43 is in contact with a metal developing roller 41 has been described. However, the present invention is not limited to such a configuration. For example, the present invention can also be applied to a one-component developing type non-contact type developing apparatus in which a thin layer blade made of an elastic resin or the like is brought into contact with a metal developing roller. By using a thin layer blade made of an elastic resin or the like in this way, it is possible to prevent wear and prolong the life of the metal developing roller.

  In addition, the one-component developing device 41 configured to abut the surface of the developing roller 42 on the free end side of the thin blade 43 has been described, but the present invention is not limited to such a configuration. For example, the present invention can also be applied to a developing device of a one-component developing system having a configuration in which a flat portion of a thin blade is brought into contact with a developing roller, that is, a so-called belly contact. In this way, by bringing the thin blade into contact with the surface of the developing roller, wear of the thin layer blade is suppressed, and fluctuations in the pressing force against the surface of the developing roller are suppressed to reduce the thickness of the thin layer of toner and frictional charging. The deviation of the toner charge amount due to the toner can be reduced.

What has been described above is merely an example, and the present invention has a specific effect for each of the following modes.
(Aspect A)
A developer carrying member such as a developing roller that conveys the developer by rotating the developer such as the carried toner to a developing region facing the latent image carrying member such as the photosensitive member 2 on which the electrostatic latent image is formed; A developer regulating member such as a thin layer blade 43 that regulates the amount of developer carried on the developer carrying member and a part of the developer regulating member are exposed from the developer powder surface, and developed on the developer carrying member. In a developing device such as a one-component developing device 41 having a developer supply body such as a supply roller 44 for supplying the developer, a developer supply port such as a developer supply port 53 for supplying the developer into the developing device; A partition member such as a partition member 51 provided between the developer supply port and the developer supply body and reaching at least below the developer powder surface; and the developer supply port partitioned by the partition member Detects the height of the developer powder surface on the side. Developer powder level detection means such as the developer powder level detection means 52, the developer powder level detection means in the longitudinal direction of the developer carrier, the developer replenishment across the center of the development region It is arranged on the side opposite to the mouth.
According to this, as described in the first embodiment (to 3), the influence of driving the developer supplying body to the developer powder surface detecting means for detecting the height of the developer powder surface is reduced, and the image density is reduced. It is possible to provide a developing device that can suppress the occurrence of image quality degradation such as a deviation as compared with the prior art.

(Aspect B)
In (Aspect A), the developer carrying member such as the developing roller 42 has uneven portions such as grooves of a mesh-like uneven pattern regularly arranged on the surface thereof. Is.
According to this, as described in the second embodiment (to 3), in addition to the effect of (Aspect A), it is possible to suppress the deterioration of the developer such as toner accommodated in the developing device such as the one-component developing device 41. At the same time, the image density can be stabilized.

(Aspect C)
In (Aspect A) or (Aspect B), the lower limit such as the lower limit 61 of the range for detecting the height of the developer powder surface by the developer powder surface detection means such as the developer powder surface detection means 52 is the supply roller 44. The developer supply body is located above the lowermost part in the height direction of the developer supply body.
According to this, as explained in the first embodiment (to 3), the following effects can be obtained. The height of the developer powder surface is replenished with the developer so as to contact the developer supply body, so that the developer can always be supplied to the developer supply body. Even if the developer is consumed, a thin developer layer can be formed again after one revolution. Therefore, it is possible to supply the developer to the stable developer carrier.

(Aspect D)
In any one of (Aspect A) to (Aspect C), a vertically lower region of the partition member such as the partition member 51, a vertically lower region of the developer supply body such as the supply roller 44, and the developer supply port 53. A first stirrer such as a paddle 45 that stirs at least a part of each developer such as toner in a region vertically below the developer replenishing port, and the partition member and the first stirrer than the first stirrer A second stirrer such as a stirring and conveying screw 54 that stirs the developer is provided near the developer supply port, and the second stirrer is developed in the longitudinal direction such as the longitudinal direction of the developing roller 42. The first stirrer is capable of transporting the developer, and the first stirrer also stirs at least a part of the developer in a region vertically below the second stirrer.
According to this, as explained in the third embodiment, the following effects can be obtained. The newly replenished developer is uniformly diffused in the longitudinal direction by the second stirrer, and sufficiently stirred by the first stirrer before reaching the surface of the developer supply body to regulate the developer powder surface height. It can be made uniform over the entire region. Therefore, the occurrence of image quality deterioration such as an image density deviation in the longitudinal direction of the one-component developing device 41 can be suppressed more than (Aspect A) to (Aspect C).

(Aspect E)
In any one of (Aspect A) to (Aspect D), a one-component developer mainly composed of toner is used as the developer.
According to this, as explained in the present embodiment, the following effects can be obtained. In a one-component developing type developing device such as the one-component developing device 41, the influence of driving of a developer supply body such as a supply roller 44 to the developer powder level detecting unit such as the developer powder level detecting unit 52 is likely to increase. Further, it is possible to reduce the influence of driving the developer supply body.

(Aspect F)
In an image forming apparatus such as a multi-function apparatus 300 including a developing device that develops a latent image such as an electrostatic latent image formed on a latent image carrier such as the photoreceptor 2 with a developer such as toner, the developing device As described above, a developing device such as the one-component developing device 41 of any one of (Aspect A) to (Aspect E) is provided.
According to this, as described in the present embodiment, it is possible to provide an image forming apparatus that can achieve the same effects as any of the developing devices of (Aspect A) to (Aspect E).

(Aspect G)
At least a latent image carrier such as the photosensitive member 2 and a developing device for developing a latent image such as an electrostatic latent image formed on the latent image carrier with a developer such as toner are integrated with a common holder. In a process unit that is held and detachable from the main body of the image forming apparatus such as the multi-function apparatus 300, any one of the development apparatuses (Aspect A) to (Aspect E) is held by the holder as the development apparatus. It is characterized by.
According to this, as described in the present embodiment, it is possible to provide a process unit that can achieve the same effects as any of the developing devices of (Aspect A) to (Aspect E).

DESCRIPTION OF SYMBOLS 1 Image forming unit 2 Photoconductor 3 Optical writing unit 4 Intermediate transfer belt 5 Intermediate transfer unit 6 Belt cleaning device 7 Secondary transfer roller 8 Fixing unit 10a, b Paper feed cassette 10c Manual feed tray 11 Toner supply container 16 Registration roller pair 17 Primary transfer roller 31 Two-component developing device 32 Developing sleeve 33 Regulating blade 34 Lubricant coating blade 35 Agitating and conveying screw (two-component developing device)
36 Photoconductor cleaning blade (two-component developing device)
37 Charging roller (two-component developing device)
38 Lubricant application brush 39 Solid lubricant 41 1-component developing device 42 Developing roller 42b Cylindrical region 42a Uneven region 42c Shaft portion 43 Thin layer blade 44 Supply roller 45 Paddle 45b Mylar 45a Paddle shaft 46 Photoconductor cleaning blade (single component development) apparatus)
47 Charging roller (single component developing device)
51 Partition member 52 Developer powder level detection means 53 Developer supply port 54 Stirring and conveying screw (one-component developing device)
57 Center line 61 Lower limit (developer powder surface)
61 'upper limit (developer powder surface)
DESCRIPTION OF SYMBOLS 100 Main body 200 Scanner part 300 Multifunction machine P Recording medium

Japanese Patent No. 4026977

Claims (7)

The developer carrying member transported by rotating the carried developer to the developing area facing the latent image carrying member on which the electrostatic latent image is formed, and the amount of developer carried on the developer carrying member are regulated. In a developing device comprising: a developer regulating member that is arranged; and a developer supply body that is arranged so that a part of the developer regulating member is exposed from the developer powder surface and that supplies the developer onto the developer carrying member.
A developer replenishing port for replenishing the developer in the developing device, a partition member provided between the developer replenishing port and the developer supply body, and reaching at least below the developer powder surface; and the partition A developer powder level detecting means for detecting the height of the developer powder surface on the developer supply port side partitioned by a member;
The developing device, wherein the developer powder level detecting means is disposed on the opposite side of the developer replenishing port across the center of the developing region in the longitudinal direction of the developer carrier. The developing device according to claim 1,
The developing device according to claim 1, wherein the developer carrying member has irregular portions regularly arranged on a surface thereof. The developing device according to claim 1 or 2,
2. A developing device according to claim 1, wherein a lower limit of a range in which the height of the developer powder surface detected by the developer powder surface detecting means is detected is higher than a lowermost portion in the height direction of the developer supply body. The developing device according to any one of claims 1 to 3,
A first stirrer that stirs at least a portion of each developer in a vertically lower region of the partition member, a vertically lower region of the developer supply body, and a vertically lower region of the developer supply port;
The partition member and the first stirrer are disposed closer to the developer supply port than the first stirrer, and a second stirrer that stirs the developer is provided.
The second stirrer has a transport ability to transport the developer in the longitudinal direction,
The developing device, wherein the first stirring body stirs at least a part of the developer in a region vertically below the second stirring body. The developing device according to any one of claims 1 to 4,
A developing device using a one-component developer as a developer. In an image forming apparatus including a developing device that develops a latent image formed on a latent image carrier with a developer,
An image forming apparatus comprising the developing device according to claim 1 as the developing device. A process in which at least a latent image carrier and a developing device that develops a latent image formed on the latent image carrier with a developer are integrally held on a common holder and can be attached to and detached from the image forming apparatus main body. In the unit
6. A process unit, wherein the developing device according to claim 1 is held by the holding body as the developing device.

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