JP2002351213A - Developing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developing device equipped with a developer restricting member cooling means which does not necessitate installation of a large size peltier element for cooling the developer restricting member, and prevents scattering of the developer by directly jetting air. SOLUTION: The developing device 1 has a developing container (developer housing means) 4 housing a powder developer, a roller-like developing sleeve (developer carrying means) 3 carrying the developer on the surface rotatably supported by the developing container 4, and a developing blade (developer layer thickness restricting means) 6. A heat pipe 8 is abutted to the surface of the developing blade 6, and the peltier element (cooling means) 9 is disposed on a part of the heat pipe 8. Since the heat of the developing blade 6 can be moved by the heat pipe 8, it becomes possible to cool at the part apart from the edge part of an image forming device body of the developing device 1, and thus scattering of the developer can be prevented due to reduction of the influence of air by a fan F to the developing device 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device for developing an electrostatic latent image formed on an image carrier by an electrophotographic method or an electrostatic recording method with a powdery developer.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus such as a copying machine, a printer, and a facsimile which forms an image by an electrophotographic method or the like, when an electrostatic latent image is developed, as shown in FIG.
A developer regulating member 6 is disposed at a predetermined interval to form a developer layer on the developer carrying means 3, and the developer T is rotated by the developer carrying means 3 so that the developer T is brought into close proximity to the developer regulating member 6. 6a is known. FIGS. 7 and 8 show that the developer T is prevented from fusing to the developer regulating member 6 or the developer carrying means 3 due to frictional heat in the rubbing portion between the developer regulating member 6 and the developer carrying means 3. As described above, the heat sink 7 is provided on the surface of the developer regulating member 6 to promote heat radiation, and the temperature of the developer regulating member 6 is prevented from rising by blowing air with the fan F. Note that FIG.
8, 1 is a developing device, 2 is a photosensitive drum, 4
Denotes a developing container, and 11, 12, and 13 denote stirring means.

Japanese Patent Application Laid-Open No. 08-278696 proposes a configuration in which a Peltier element is disposed so as to directly contact a developer regulating member.

[0004]

However, in the above-described conventional configuration, the developer is liable to be scattered inside the image forming apparatus main body by blowing air with a fan, and image formation such as dirt on an exposed portion is caused. There is a possibility that image quality may be degraded due to adverse effects on the system.

Further, if the heat is not sufficiently exhausted, the temperature inside the main body rises, and the developer is fused on the photosensitive drum and the cleaner portion. Therefore, a fan or duct for exhausting heat must be added. However, there is a problem that the size of the apparatus is increased and the noise due to the operation noise of the fan is deteriorated.

Further, when the Peltier element is directly disposed on the developer regulating member, heat is absorbed at the portion where the Peltier element is disposed, so that the Peltier element must be disposed substantially over the entire area of the developer regulating member. In addition, the device becomes large and expensive. In addition, since the heat dissipating portion is located on the photosensitive drum side in terms of configuration, there is a problem that heat dissipating means for dissipating heat must be provided.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to cool the developer regulating member without spraying air or providing a large Peltier element, and the effect of air can be reduced. It is an object of the present invention to provide a developing device capable of preventing the scattering of the developer by reducing the amount of the developer.

[0008]

In order to achieve the above object, the invention according to claim 1 comprises a developer accommodating means for accommodating a powder developer and a surface rotatably supported by the developer accommodating means. In a developing device having a roller-like developer carrying means for carrying a developer and a developer layer thickness regulating member, a heat pipe is brought into contact with the surface of the developer layer thickness regulating member, and a part of the heat pipe is formed. A cooling means.

According to a second aspect of the present invention, in the first aspect of the present invention, at least one end of the heat pipe projects from an end in the longitudinal direction of the developer layer thickness regulating member, and the projecting portion has the cooling means. Is provided.

According to a third aspect of the present invention, in the first or second aspect, the cooling means is constituted by a Peltier element.

According to a fourth aspect of the present invention, when the heat pipe is fixed to the image forming apparatus main body and the developing device is mounted on the image forming apparatus main body in the first, second or third aspect of the present invention. When the heat pipe is in contact with the developer layer thickness regulating member and the developing device is taken out of the image forming apparatus main body, the heat pipe is separated from the developer layer thickness regulating member.

Therefore, according to the present invention, the heat of the developer layer thickness regulating member can be moved by the heat pipe by bringing the heat pipe into contact with the surface of the developer layer thickness regulating member. Cooling can be performed at a portion distant from the end of the forming apparatus main body, and the effect of air from the fan on the developing device is reduced, so that scattering of the developer can be prevented.

[0013]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

<First Embodiment> FIG. 1 is a sectional view of an image forming apparatus having a developing device according to the present invention, FIG. 2 is a partial plan view of the developing device according to the present invention, and FIG. FIG.

In the image forming apparatus A shown in FIG. 1, a developing device 1 according to the present invention is disposed near a photosensitive drum 2 as an image carrier.

The developing device 1 according to the present invention is shown in FIGS.
As shown in FIG. 1, a rotatable developing sleeve 3 as a developer carrying means is provided at an opening facing a photosensitive drum 2 in a developing container 4 serving as a developer accommodating means. Are arranged at a predetermined interval. Incidentally, a magnet roller (not shown) as a magnetic field generating means is fixed and installed inside the developing sleeve 3, and a magnetic pole such as a developer pumping pole or a developing pole is disposed on the surface of the magnet roller. In FIG. 3, reference numerals 11, 12, and 13 denote stirring means.

The developer (toner) T adsorbed on the surface of the developing sleeve 3 by the developer pumping pole of the magnet roller or the like is disposed at a predetermined distance from the developing sleeve 3. The thickness is reduced by the interaction between the developing blade 6 and the developer layer thickness regulating electrode.

A heat pipe 8 is provided on the developing blade 6 in the longitudinal direction, and a Peltier element 9 and a heat sink 7 are provided near the end of the heat pipe 8. Here, the heat absorption side of the Peltier element 9 is in contact with the heat pipe 8, and the heat radiation side is in contact with the heat sink 7. Air is blown to the heat sink 7 by the fan F.

According to this configuration, the frictional heat generated in the rubbing portion between the developing sleeve 3 and the developing blade 6 due to the rotation of the developing sleeve 3 is moved by the heat pipe 8 to be separated from the end of the main body of the developing device 1. Since the cooling at the portion where the heat is applied becomes possible, there is no need to blow the air to the developing device 1 or to provide a large Peltier element. Can be prevented.

<Embodiment 2> Next, Embodiment 2 of the present invention will be described with reference to FIG. FIG. 4 is a partial plan view of the developing device according to the present embodiment, in which the same elements as those shown in FIGS. 2 and 3 are denoted by the same reference numerals.

In the present embodiment, the heat pipe 8
Is extended to the outside of a side plate 41 constituting a housing of the image forming apparatus main body, and a Peltier element 9 and a heat sink 7 are arranged near an end of the heat pipe 8. The heat absorption side of the Peltier element 9 is in contact with the heat pipe 8, the heat radiation side is in contact with the heat sink 7, and air is blown against the heat sink 7 by the fan F. Incidentally, the heat pipe 8 may be fixed to a stay (not shown) of the image forming apparatus main body.

According to this configuration, the air from the fan F is almost completely prevented from being blown toward the developing device 1 by the stay 41, so that the effect of the first embodiment becomes more reliable.

<Embodiment 3> Next, an embodiment of the present invention will be described with reference to FIGS. 5 and 6 are cross-sectional views of the developing device according to the present embodiment. In these drawings, the same elements as those in FIGS. 2 and 3 are denoted by the same reference numerals.

In the present embodiment, the heat pipe 8
Is fixed to a fixing portion 21a of a stay 21 of the image forming apparatus main body.

According to this configuration, in addition to the effects of the first embodiment, the developing device 1 can be moved in the direction of the arrow in FIG.
The developing device 1 can be taken out without damaging the surface of the developing device 1. In this case, the effect that the developing device 1 can be easily attached and detached since the developing device 1 can be downsized can be obtained.

[0026]

As is apparent from the above description, according to the present invention, the developer accommodating means accommodating the powder developer, and the developer accommodating means rotatably supported by the developer accommodating means. In a developing device having a roller-shaped developer carrying means for carrying and a developer layer thickness regulating member, a heat pipe is brought into contact with the surface of the developer layer thickness regulating member, and a cooling means is provided on a part of the heat pipe. Because of this, it is possible to cool the developer regulating member without blowing air to the developing device or providing a large Peltier element, and reduce the influence of air on the developing device to prevent the developer from scattering. The effect that it can be obtained is obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view of an image forming apparatus provided with a developing device according to the present invention.

FIG. 2 is a partial plan view of the developing device according to the first embodiment of the present invention.

FIG. 3 is a sectional view of the developing device according to the first embodiment of the present invention.

FIG. 4 is a partial plan view of a developing device according to a second embodiment of the present invention.

FIG. 5 is a sectional view of a developing device according to a third embodiment of the present invention.

FIG. 6 is a sectional view of a developing device according to a third embodiment of the present invention.

FIG. 7 is a sectional view of a conventional developing device.

FIG. 8 is a partial plan view of a conventional developing device.

[Description of Signs] 1 Developing device 2 Photosensitive drum 3 Developing sleeve (Developer holding means) 4 Developing container (Developer storing means) 6 Developing blade (Developer layer thickness regulating member) 7 Heat sink 8 Heat pipe 9 Peltier element (Cooling) Means) T developer F fan

Claims (4)

[Claims] 1. A developer accommodating means accommodating a powder developer, a roller-shaped developer carrying means rotatably supported by the developer accommodating means and carrying the developer on a surface, and a developer layer thickness. A developing device having a regulating member, wherein a heat pipe is brought into contact with the surface of the developer layer thickness regulating member, and cooling means is provided in a part of the heat pipe. 2. At least one end of the heat pipe is protruded from a longitudinal end of the developer layer thickness regulating member,
2. The developing device according to claim 1, wherein said cooling means is provided at the projecting portion. 3. The developing device according to claim 1, wherein said cooling means is constituted by a Peltier element. 4. When the heat pipe is fixed to the image forming apparatus main body side and the developing apparatus is mounted on the image forming apparatus main body, the heat pipe abuts on the developer layer thickness regulating member, and the developing apparatus is connected to the image forming apparatus. 4. The developing apparatus according to claim 1, wherein the heat pipe is separated from the developer layer thickness regulating member when the heat pipe is taken out of the forming apparatus main body.