JP2015004936A - Developing device, process cartridge, and image forming apparatus using developing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developing device that can obtain the cooling effect of a two-component developer uniform in the longitudinal direction of a developer regulating member, and has a high degree of freedom of layout of the developing device to easily reduce the size thereof; and an image forming apparatus.SOLUTION: A developing device 2 includes a developer regulating member 116 that regulates the conveyance amount of a two-component developer conveyed by a developing roller, and the developer regulating member 116 has cooling air flow along the longitudinal direction thereof. In the developer regulating member 116, the end 116b on the downstream side in the flow direction of the cooling air is configured to have high heat exchange efficiency compared with the end 116a on the upstream side in the flow direction of the cooling air.

Description

  The present invention relates to a developing device, a process cartridge, and an image forming apparatus using the developing device, and more particularly to a technique of an electrophotographic image forming apparatus.

  2. Description of the Related Art Conventionally, an image forming apparatus using an electrostatic electrophotographic system generally includes charging, exposure, development, transfer, cleaning, static elimination, and fixing processes. In the step of forming an image by the image forming apparatus, for example, the surface of the photosensitive drum that is rotationally driven by the charging device is uniformly charged (charging step), and the charged photosensitive member surface is irradiated with laser light by the exposure device. Thus, an electrostatic latent image is formed (exposure process). Subsequently, the electrostatic latent image on the photoconductor is developed by the developing device, and a toner image is formed on the surface of the photoconductor (development process). The toner image on the photosensitive member is transferred onto the transfer material by the transfer device (transfer process), and then heated by the fixing device to fix the toner image on the transfer material (fixing step). Further, the transfer residual toner remaining on the surface of the photoconductor is removed by a cleaning device and collected in a predetermined collection unit (cleaning process), and the remaining charge is removed from the surface of the photoconductor after cleaning by a static eliminator. Prepare for image formation (static elimination process).

  As the developer for developing the electrostatic latent image on the photoreceptor, a one-component developer composed of only toner or a two-component developer composed of toner and carrier is generally used. The one-component developer does not use a carrier, and thus has an advantage that a developing device is simplified without requiring a stirring mechanism for uniformly mixing the toner and the carrier, but the toner charge amount is difficult to stabilize. There are disadvantages such as. The two-component developer requires a stirring mechanism for uniformly mixing the toner and the carrier, and thus has a disadvantage that the developing device becomes complicated. However, since the charge amount stability is excellent, a high-speed image can be obtained. It is often used in forming apparatuses and color image forming apparatuses.

  As a developing device using a two-component developer, a developing device including a developing tank, a developing roller, a stirring member, a developer regulating member, a sink plate and the like is generally used. The developing tank rotatably supports the developing roller and the stirring member, and stores the developer therein. The developing roller rotates while carrying a developer layer on the surface, and supplies toner to the electrostatic latent image on the surface of the photoreceptor to form a toner image. The agitating member uniformly agitates the developer in the developing tank and conveys the developer toward the developing roller. The developer regulating member regulates the layer thickness of the developer layer on the surface of the developing roller.

  In the developer such as a two-component developer, in order to cope with higher printing speed, colorization, and energy saving, the toner has become smaller in particle size and lower in softening point. , It has the disadvantage of being easily aggregated by heat. For this reason, when the temperature of the developer rises due to frictional heat when stirring in the developing device, problems such as toner aggregation and a decrease in the fluidity of the developer occur, resulting in uneven image density.

  To solve this problem, for example, Patent Document 1 describes a developing device that cools a two-component developer by forming the inside of a developer regulating member into a hollow shape and flowing a cooling air therein. Yes.

JP 2004-109868 A

However, in the developing device described in Patent Document 1, in the flow direction of the cooling air of the developer regulating member, the temperature of the cooling air rises from the upstream side to the downstream side, and the cooling effect decreases. There has been a problem that the cooling effect of the developer becomes non-uniform in the longitudinal direction.
Further, in the developing device according to the prior art, since it is necessary to provide a ventilation path for flowing cooling air on the side surface of the developer regulating member, there is a problem that the layout freedom of the developing device is lost and miniaturization is difficult. there were.

  In view of the above problems, the object of the present invention is to obtain a uniform developer cooling effect in the longitudinal direction of the developer regulating member, and to have a high degree of freedom in layout of the developing device and facilitate downsizing. A developing device and an image forming apparatus are provided.

  Hereinafter, means for solving the above problems will be described.

  The developing device of the present invention that solves the above problem includes a developer regulating member that regulates the amount of developer conveyed by the developing roller, and cooling air flows along the longitudinal direction of the developer regulating member. The downstream side in the flow direction of the cooling air in the developer regulating member is configured to have higher heat exchange efficiency than the upstream side in the flow direction of the cooling air. Features.

  In the developing device of the present invention that solves the above problem, the downstream side of the developer regulating member in the flow direction of the cooling air has a unit length of the cooling air as compared with the upstream side in the flow direction of the cooling air. It is characterized by being configured so that the contact area per contact becomes large.

  Further, the developer regulating member is formed in a hollow cylindrical shape, and cooling air is circulated therein, and the downstream side of the developer regulating member in the flow direction of the cooling air is upstream of the flow direction of the cooling air. The inner diameter is larger than that of the side.

  In addition, the developer regulating member is formed in a cylindrical shape.

  Further, the developer regulating member is disposed at each end of the hollow cylindrical member and the cylindrical member, each of which has a uniform inner diameter in the longitudinal direction and through which cooling air flows. An upstream flow rate regulating member and a downstream flow rate regulating member that are open to the flow hole, and an inner diameter of the circulation hole opened in the downstream flow rate regulating member is opened in the upstream flow rate regulating member. Further, it is configured to be larger than the inner diameter of the flow hole.

  Further, the developer regulating member is formed in a plate shape or a rod shape, and a plurality of cooling ribs are provided to perform heat exchange with the cooling air along a direction in which the cooling air flows. A surface area of the cooling rib formed on the downstream side in the direction is configured to be larger than a surface area of the cooling rib formed on the upstream side in the flow direction of the cooling air.

  The cooling air is circulated by a suction type fan or pump.

  In addition, a process cartridge of the present invention that solves the above problems includes a photosensitive drum on which an electrostatic latent image is formed, a charging device that charges the surface of the photosensitive drum, and an electrostatic latent image on the surface of the photosensitive drum. A developing device according to any one of claims 1 to 7, which develops an image into a toner image.

  In addition, an image forming apparatus of the present invention that solves the above problems includes a photosensitive drum on which an electrostatic latent image is formed, a charging device that charges the surface of the photosensitive drum, and a static on the surface of the photosensitive drum. An exposure device that forms an electrostatic latent image; a developing device that develops the electrostatic latent image on the surface of the photosensitive drum into a toner image; and the developer regulating member. A blower that circulates cooling air in the longitudinal direction; a transfer device that transfers a toner image formed on the surface of the photosensitive drum to a recording medium; and a fixing device that fixes the transferred toner image to the recording medium; Is provided.

  According to the present invention, by increasing the heat exchange efficiency downstream from the upstream side in the flow direction of the cooling air of the developer regulating member, the developer cooling effect uniform in the longitudinal direction of the developer regulating member is obtained. It becomes possible.

1 is an explanatory diagram illustrating an overall configuration of an image forming apparatus including a developing device according to an embodiment of the present invention. FIG. 2 is a schematic enlarged cross-sectional view of the developing device shown in FIG. 1. FIG. 3 is a cross-sectional view taken along line AA in FIG. 2. FIG. 3 is a cross-sectional view taken along line B-B in FIG. 2. (A) to (c) is a view showing a developer regulating member in each embodiment.

[Image forming apparatus 100]
Hereinafter, embodiments of a developing device and an image forming apparatus according to the present invention will be described in detail with reference to the drawings.
FIG. 1 is an explanatory diagram showing an overall configuration of an image forming apparatus 100 including a developing device 2 (2a to 2d) according to an embodiment of the present invention.

  The image forming apparatus 100 is a full-color printer that can form a color image on a sheet-like recording medium (recording paper) in accordance with image data transmitted from the outside.

  In the present embodiment, the case where the image forming apparatus is a printer is illustrated, but the image forming apparatus may be a recording medium according to image data transmitted from the outside and / or image data read from a document by a scanner. It may be a copier capable of forming a multicolor or single color image, a facsimile machine, or a multifunction machine having these functions.

  The image forming apparatus 100 includes four photosensitive drums 3a to 3d on which electrostatic latent images are formed, four chargers (charging devices) 5a to 5d for charging the surfaces of the photosensitive drums 3a to 3d, Laser scanner unit (exposure device) 1 for forming an electrostatic latent image by irradiating the surface of each of the photosensitive drums 3a to 3d with laser light, and separately accommodating black, cyan, magenta and yellow toners. Four developing devices 2a to 2d that develop electrostatic latent images on the surfaces of the drums 3a to 3d to form toner images, and remove residual toner remaining on the surfaces of the photosensitive drums 3a to 3d after development and image transfer Cleaner units 4a to 4d, four toner replenishing devices (toner cartridges) 9a to 9d for individually replenishing the developing devices 2a to 2d with the four color toners and carriers, The intermediate transfer belt 7 to which the toner images on the surfaces 3a to 3d are transferred, the intermediate transfer rollers 6a to 6d for transferring the toner images on the surfaces of the photosensitive drums 3a to 3d to the surface of the intermediate transfer belt 7, and a recording medium are accommodated. A paper feed tray 10 that picks up a recording medium from the paper feed tray 10, a transfer roller 11 that transfers the toner image on the surface of the intermediate transfer belt 7 to the recording medium, and a recording medium from the paper feed tray 10 to the transfer roller 11. A conveying roller 17a for conveying the toner, a fixing device 12 for fixing the toner image transferred onto the recording medium, and conveying rollers 17b and 17c for conveying the recording medium from the fixing device 12 to the outside of the image forming apparatus 100 (broken arrows shown in FIG. 1). A), inside the image forming apparatus 100, the longitudinal direction of each of the developing devices 2a to 2d (directly with the paper surface in FIG. 1). (Not shown) for circulating the cooling air in the direction) comprising a like blower. The upper surface of the image forming apparatus 100 is formed as a paper discharge tray 15.

  In each of the members indicated by reference numerals having a to d, a is a member for forming a black image, b is a member for forming a cyan image, c is a member for forming a magenta image, and d is a member for forming a yellow image. It is a member. The transfer device in this embodiment includes intermediate transfer rollers 6 a to 6 d, an intermediate transfer belt 7, and a transfer roller 11. As shown in FIG. 1, the intermediate transfer belt 7 disposed above each photosensitive drum 3 is stretched by a driving roller 71 and a driven roller 72 and rotates in the direction of arrow B shown in FIG.

  The image forming apparatus 100 has a black toner image, a cyan toner image, a magenta toner image, and a yellow toner on the surface of each of the photosensitive drums 3a to 3d based on the image data for each color component of black, cyan, magenta, and yellow. Images are selectively formed, and the formed toner images are superimposed on the intermediate transfer belt 7 to form a color image on the recording medium. Then, the transfer device fixes the toner images superimposed on the intermediate transfer belt 7 onto a recording sheet as a recording medium and discharges it.

  Since the photosensitive drums 3a to 3d corresponding to the respective colors have the same configuration, in the description of the configuration, the reference numeral is unified to 3. Similarly, the developing device has the reference numeral 2, the charger has the reference numeral 5, the cleaner The unit will be described with the reference numeral 4 and the toner replenishing apparatus with the reference numeral 9. In the present embodiment, the developing device 2, the photosensitive drum 3, and the charger 5 will be described as separate members, but they can also be configured as an integral process cartridge.

[Developing device 2]
2 is a schematic enlarged sectional view of the developing device 2 (2a to 2d) shown in FIG. 1, FIG. 3 is a sectional view taken along line AA in FIG. 2, and FIG. 4 is a sectional view taken along line BB in FIG. It is a cross-sectional arrow view.
In these drawings, the two-component developer accommodated in the developing tank 111 is not shown. In this embodiment, a configuration in which a two-component developer including a toner and a carrier is used as the developer will be described. However, a configuration in which a one-component developer composed only of toner is used as the developer can also be used. .

As shown in FIGS. 2 to 4, the developing device 2 is divided into a pair by a developing tank 111 containing a two-component developer, a partition wall 117 that partitions the inside of the developing tank 111, and a partition wall 117. A first developer transport path P and a second developer transport path Q that circulate and transport the two-component developer, a removable developer tank cover 115 that constitutes the upper wall of the developer tank 111, and a developer tank 111. The developer roller 114 and the first developer transport path P and the second developer transport path Q are rotatably provided in the respective directions facing the two-component developer (arrows X and A first developer member 112 and a second carrier member 113 that are conveyed to the developer tank 111 and circulated in the developer tank 111, and the two-component developer in the first developer conveyance path P is second developer. A first communication path a leading to the transport path Q; A second communication path b that guides the two-component developer in the second developer transport path Q to the first developer transport path P, a developer regulating member 116, and a toner concentration detection sensor (magnetic permeability sensor) 119. Prepare. The developing device 2 supplies toner to the surface of the photosensitive drum 3 by the developing roller 114 to develop the electrostatic latent image formed on the surface of the photosensitive drum 3.
The developer tank cover 115 is provided with a toner replenishing port 115a for replenishing unused toner on the upstream side (left side in FIG. 3) in the developer transport direction (arrow X direction) in the first developer transport path P. ing.

  The inside of the developing tank 111 is divided into two rooms by a partition plate 117 parallel to the axial direction of the developing roller 114. Of the two chambers, a first developer transport path P is provided on the side of the toner replenishing port 115a opened in the developer tank cover 115 (the right side in FIG. 2 and the lower side in FIG. 3). A second developer transport path Q is provided adjacent to P. Further, the first developer transport path P and the second developer transport path Q communicate with each other through the first communication path a and the second communication path b on both sides in the axial direction. In other words, the first and second developer transport paths P and Q and the first and second communication paths a and b constitute one annular developer transport path.

  The developing roller 114 is a magnet roller that is rotationally driven around a shaft center (see an arrow α shown in FIG. 2) by a driving unit (not shown), and carries the two-component developer in the developing tank 111 on the surface thereof. Is supplied to the photosensitive drum 3. The developing roller 114 is supplied with a developing bias voltage from a power source (not shown), so that toner is supplied from the two-component developer on the surface thereof to the electrostatic latent image on the surface of the photosensitive drum 3.

  The first developer conveying spiral member 112 is fixed to the first rotating shaft 112a provided in the first developer conveying path P so as to be parallel and rotatable in the developer conveying direction, and to the outer peripheral surface of the first rotating shaft 112a. The auger screw includes a first spiral blade 112b and a first gear 112c provided at one end of the first rotating shaft 112a protruding to the outside of the developing tank 111. The first developer conveying spiral member 112 is rotationally driven by a drive motor (not shown) (see arrow β shown in FIG. 2), and stirs the two-component developer in the first developer conveying path P in the arrow X direction. Transport while.

  The second developer conveying spiral member 113 is fixed to the second rotating shaft 113a provided in the first developer conveying path Q so as to be parallel and rotatable in the developer conveying direction, and to the outer peripheral surface of the second rotating shaft 113a. The auger screw includes a second spiral blade 113b and a second gear 113c provided at one end of the first rotating shaft 113a protruding to the outside of the developing tank 111. The second developer conveying spiral member 113 is rotationally driven by a driving motor (not shown) (see arrow γ shown in FIG. 2), and stirs the two-component developer in the second developer conveying path Q in the arrow Y direction. Transport while.

The toner concentration detection sensor 119 is mounted on the bottom surface of the developing tank 111 directly below the second developer transport spiral member 113 and at the substantially central portion of the second developer transport path Q. The second developer conveyance path Q is exposed. As the toner concentration detection sensor 119, for example, a general toner concentration detection sensor such as a transmitted light detection sensor, a reflected light detection sensor, or a permeability detection sensor can be used, and among these, a permeability detection sensor is preferable. .
The image forming apparatus 100 drives the toner replenishing device 9 in accordance with the toner density measurement value detected by the toner density detecting sensor 119, and causes the toner to enter the first developer transport path P of the developing device 2 from the toner replenishing port 115a. It is configured to supply.

  The developer regulating member 116 is a member generally called a doctor blade. The developer regulating member 116 is a cylindrical member that extends in parallel with the axial direction of the developing roller 114 and has an annular cross section, and both ends thereof are fixed to the developing tank 111. The developer regulating member 116 is arranged so that the distance from the developing roller 114 is a predetermined distance, and regulates the two-component developer carried on the developing roller 114 to an appropriate constant amount. One end of the developer regulating member 116 is connected to a suction type blower (not shown), and the cooling air is guided into the developer regulating member 116 so that the two-component developer carried on the developing roller 114 is To be cooled. In other words, cooling air is circulated through the developer regulating member 116 along the longitudinal direction of the developer regulating member 116 by the blower, and the developer regulating member 116 cools the two-component developer. In the present embodiment, as shown by an arrow F in FIGS. 4 and 5A, the cooling air flows from the left side to the right side. That is, in FIG. 4 and FIG. 5A, the left end portion of the developer regulating member 116 is the upstream end portion 116a in the cooling air flow direction, and the right end portion is the downstream end portion 116b in the cooling air flow direction. A fan or a pump is used as the blower. As will be described later, the inner diameter of the hollow developer regulating member 116 is larger on the downstream side than on the upstream side in the flow direction of the cooling air.

  As described above, the developing device 2 according to this embodiment includes the developer regulating member 116 that regulates the transport amount of the two-component developer transported by the developing roller 114, and the developer regulating member 116 has a longitudinal direction. Cooling air is distributed. The downstream end portion 116b in the flow direction of the cooling air in the developer regulating member 116 is configured to have higher heat exchange efficiency than the upstream end portion 116a in the flow direction of the cooling air.

Specifically, as shown in FIG. 5A, the developer regulating member 116 is configured such that the inner diameter of the downstream end 116b is larger than the inner diameter of the upstream end 116a.
As a result, the downstream end portion 116b in the flow direction of the cooling air in the developer regulating member 116 has a contact area per unit length with the cooling air as compared with the upstream end portion 116a in the flow direction of the cooling air. growing. That is, the area where the inner peripheral surface of the developer regulating member 116 is in contact with the cooling air is configured to be larger on the downstream side than on the upstream side, so that the heat exchange efficiency of the downstream end portion 116b is increased on the upstream side. This is higher than the heat exchange efficiency of the end portion 116a.
In this embodiment, as shown in FIG. 4, the inner diameter of the developer regulating member 116 gradually increases from the upstream side to the downstream side between the upstream end portion 116a and the downstream end portion 116b. It is configured to expand.

  The developing device 2 according to the present embodiment is configured as described above, so that even if the temperature of the cooling air rises from the upstream side to the downstream side in the cooling air flow direction of the developer regulating member 116, the development is performed. Since the heat exchange efficiency on the downstream side of the developer regulating member 116 is higher than the upstream side in the flow direction of the cooling air, the cooling effect in the longitudinal direction of the developer regulating member 116 can be made uniform. In other words, the cooling effect of the two-component developer can be made uniform in the longitudinal direction of the developer regulating member 116.

  Further, the developer regulating member 116 according to the present embodiment is formed in a highly rigid cylindrical shape. As a result, sufficient strength can be ensured even if the diameter of the developer regulating member 116 is reduced, so that the degree of freedom in layout of the developing device 2 can be increased and the size can be easily reduced.

  In this embodiment, the cooling air is circulated by a blower constituted by a suction type fan or pump. Thereby, since the cooling air is not compressed when the cooling air is circulated through the developer regulating member 116, the temperature rise of the cooling air can be suppressed.

  In the present embodiment, the developer regulating member 116 is formed in a cylindrical shape, but the shape is not limited to the cylindrical shape. That is, the downstream side of the cooling air in the developer regulating member is configured to increase the heat exchange efficiency by increasing the contact area per unit length with the cooling air compared to the upstream side of the cooling air. If it does, there is no problem.

  Specifically, as in the second embodiment shown in FIG. 5B, the developer regulating member 216 is formed of a plate-like member (or a rod-like member), and the direction in which the cooling air flows (the arrow in FIG. 5B). A plurality of cooling ribs 216r, 216r,... For performing heat exchange with the cooling air are erected along the direction F). The surface area of the cooling rib 216r formed on the downstream side of the developer regulating member 216 is configured to be larger than the surface area of the cooling rib 216r formed on the upstream side. In this embodiment, the cooling air circulates around the developer regulating member 216.

  By configuring as described above, the downstream end portion 216b of the cooling air in the developer regulating member 216 has a larger contact area per unit length with the cooling air than the upstream end portion 216a of the cooling air. Become. That is, the area where the surface of the developer regulating member 216 is in contact with the cooling air is configured so that the downstream side is larger than the upstream side, so that the heat exchange efficiency of the downstream side end 216b is increased. It is also possible to make it higher than the heat exchange efficiency of 216a.

  Also in the developing device according to the present embodiment, by configuring the developer regulating member 216 as described above, the temperature of the cooling air increases from the upstream side to the downstream side in the cooling air flow direction of the developer regulating member 216. Even if it rises, the heat exchange efficiency on the downstream side of the upstream side of the cooling air in the developer regulating member 216 is higher than that on the upstream side, so that the cooling effect in the longitudinal direction of the developer regulating member 216 can be made uniform. That is, the cooling effect of the two-component developer can be made uniform in the longitudinal direction of the developer regulating member 216.

  As a configuration in which the heat exchange efficiency on the downstream side of the cooling air in the developer regulating member is higher than the heat exchange efficiency on the upstream side, in addition to the above-described embodiment, the material of the developer regulating member is arranged on the downstream side of the upstream side. A configuration using a material having higher thermal conductivity, a configuration formed in a cylindrical shape, and a thickness of a developer regulating member in which cooling air flows therein are made thinner on the downstream side than the upstream side, etc. are conceivable.

  In the above embodiment, the inner diameter of the developer regulating member 116 is gradually increased from the upstream side toward the downstream side, so that the inner diameter of the downstream end portion 116b is larger than the inner diameter of the upstream end portion 116a. Although configured, the developer regulating member may be formed in another shape.

  Specifically, as in the third embodiment shown in FIG. 5C, a developer regulating member is provided on each of a normal cylindrical member 316 (the inner diameter is uniform in the longitudinal direction) and both ends of the cylindrical member 316. An upstream flow rate regulating member 317a and a downstream flow rate regulating member 317b that are arranged and open in the flow holes are configured. Then, the inner diameter d2 of the flow hole opened in the downstream flow rate regulating member 317b is made larger than the inner diameter d1 of the flow hole opened in the upstream flow rate regulating member 317a. Thereby, the inner diameter of the downstream side (downstream flow rate regulating member 317b) of the cooling air in the developer regulating member is larger than the upstream side (upstream flow rate regulating member 317a) of the cooling air.

  By configuring as described above, the cooling air flowing inside the cylindrical member 316 stays on the upstream side, and flows on the inner surface of the cylindrical member 316 on the downstream side. For this reason, the cooling air flowing while contacting the inner peripheral surface of the cylindrical member 316 is more on the downstream side than on the upstream side. That is, the heat exchange efficiency on the downstream side of the cooling air in the developer regulating member can be increased as compared with the upstream side of the cooling air. This makes it possible to obtain a uniform cooling effect of the two-component developer in the longitudinal direction of the developer regulating member. Further, according to the present embodiment, since a general-purpose member can be used as the cylindrical member 316, it is possible to reduce the cost for processing the shape of the developer regulating member.

2 Developing device 114 Developing roller 116 Developer regulating member

Claims (9)

A developing device that includes a developer regulating member that regulates the conveyance amount of the developer conveyed by the developing roller, and in which the cooling air is circulated along the longitudinal direction of the developer regulating member;
The developing device according to claim 1, wherein the developer regulating member is configured such that the downstream side in the flow direction of the cooling air is higher in heat exchange efficiency than the upstream side in the flow direction of the cooling air.   The downstream side in the flow direction of the cooling air in the developer regulating member is configured to have a larger contact area per unit length with the cooling air than the upstream side in the flow direction of the cooling air. The developing device according to claim 1, wherein the developing device is characterized. The developer regulating member is formed in a hollow cylindrical shape, and cooling air is circulated therein,
The downstream side in the flow direction of the cooling air in the developer regulating member is configured to have an inner diameter larger than that in the upstream direction in the flow direction of the cooling air. Item 3. The developing device according to Item 2.   The developing device according to claim 1, wherein the developer regulating member is formed in a cylindrical shape.   The developer regulating member has a hollow cylindrical member having a uniform inner diameter in the longitudinal direction and through which cooling air is circulated, and a flow hole disposed at both ends of the cylindrical member. An upstream flow rate regulating member and a downstream flow rate regulating member, and an inner diameter of the flow hole opened in the downstream flow rate regulating member is the opening opened in the upstream flow rate regulating member. The developing device according to claim 1, wherein the developing device is configured to be larger than an inner diameter of the flow hole.   The developer regulating member is formed in a plate shape or a rod shape, and a plurality of cooling ribs are provided to perform heat exchange with the cooling air along a direction in which the cooling air flows. The surface area of the cooling rib formed on the downstream side is configured to be larger than the surface area of the cooling rib formed on the upstream side in the flow direction of the cooling air. Item 3. The developing device according to Item 2.   The developing device according to claim 1, wherein the cooling air is circulated by a suction type fan or pump. A photosensitive drum having an electrostatic latent image formed on the surface;
A charging device for charging the surface of the photosensitive drum;
A developing device according to any one of claims 1 to 7, which develops an electrostatic latent image on the surface of the photosensitive drum into a toner image. A photosensitive drum having an electrostatic latent image formed on the surface;
A charging device for charging the surface of the photosensitive drum;
An exposure device that forms an electrostatic latent image on the surface of the photosensitive drum;
The developing device according to any one of claims 1 to 7, which develops an electrostatic latent image on the surface of the photosensitive drum into a toner image;
A blower for circulating cooling air in the longitudinal direction of the developer regulating member;
A transfer device for transferring a toner image formed on the surface of the photosensitive drum to a recording medium;
An image forming apparatus comprising: a fixing device that fixes the transferred toner image to the recording medium.