JP2002357952A - Developing device and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developing device capable of efficiently restraining temperature rise due to the heat generation of developer regardless of temperature environment on the outside of the device. SOLUTION: This developing device 6Y has a developing roller 15 for supplying the developer G to a photoreceptor 3Y and carrying screws 16 and 17 for stirring and carrying the developer G. A high heat conduction member 22 as a partition is provided between the screws 16 and 17 and its upper part is led out to the outside of the device so as to constitute a heat radiation part 23 having a plurality of heat radiation fins. In order to extend heat receiving area with the developer G, a 2nd high heat conduction member 21 constituted of a graphite sheet is stuck to the inner wall surface of a lower casing 18, and comes into contact with the member 22.

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 visualizing an electrostatic latent image on an image carrier, and an image forming apparatus having the developing device, such as a copying machine, a printer, a facsimile, and the like.

[0002]

2. Description of the Related Art A tandem-type multicolor image forming apparatus includes an image forming element centered on an image carrier for each color (yellow, magenta, cyan, and black), and forms an image on each image carrier. After the images are superimposed on the intermediate transfer member, the images are collectively transferred to a sheet. There is also known a method of directly transferring to a sheet without passing through an intermediate transfer member. The tandem-type image forming apparatus has a feature that it has no color switching operation at the time of image formation and has high productivity (higher-speed output is possible) as compared with a revolver-type image forming apparatus and a side-by-side image forming apparatus. . However, on the other hand, since an image carrier is provided for each color, the size of the image forming unit tends to be large when viewed from the entire apparatus. Also, the density of the units is increased.

In an image forming apparatus, there is a high-temperature fixing device, and in an exposure section (optical writing means), in the case of laser exposure, there is a polygon motor that rotates at a high speed, which is a large heat source. . Heat generation of the light source is large even in LED exposure. In such an environment, the developing device has a mechanism for stirring and transporting the developer, and is one of the heat sources although not as large as the fixing device and the exposure unit. The developing device has a very important function in image formation, such as maintaining the charged state of the developer, and is affected by heat (convection and radiation) from devices other than the developing device. In order to save power by using a low-temperature fixing toner, it is necessary to cool and to cut off heat influence from other than the developing device (insulation) in order to avoid problems such as sticking.

[0004]

As a method for suppressing a rise in the temperature of the developing device, a general configuration is to use a material such as aluminum having a high thermal conductivity as a casing to generate an airflow on an outer wall thereof to promote heat exchange. It is. However, in a situation where there is a fixing device directly below or parts are densely packed,
In some cases, the ambient temperature is higher and the developing device is on the heat receiving side. Further, in order to generate an air flow, a space that functions as a flow path is required, but it is difficult in a situation where components are densely arranged.

Accordingly, an object of the present invention is to provide a developing device capable of efficiently suppressing a rise in temperature regardless of an external temperature environment, and an image forming apparatus having the developing device.

[0006]

According to a first aspect of the present invention, there is provided a developing apparatus for supplying a developer contained in a casing to an image carrier by a developer carrier. A high heat conductive member having high heat conductivity is provided inside the device so that the agent comes in contact with the device, and the high heat conductive member is led out of the device to form a heat radiating portion.

According to a second aspect of the present invention, in the developing device according to the first aspect, a partition for circulating the developer is provided, and the partition is the high heat conductive member.

According to a third aspect of the present invention, in the developing device of the first aspect, there is provided a developer agitating / conveying means for agitating / transporting the developer, and the developer agitating / conveying means is directed toward the high heat conductive member. The liquid is driven so that the liquid level of the developer rises.

According to a fourth aspect of the present invention, in the developing device according to the first aspect, the casing has a lower casing in which a developer is stored, and an upper casing that covers an upper portion of the lower casing. Is formed of the high heat conductive member, and the outside of the high heat conductive member is covered with a heat insulating member.

According to a fifth aspect of the present invention, in the developing device of the first aspect, the casing has a lower casing in which a developer is accommodated, and an upper casing that covers the lower casing. A developer regulating member for regulating the thickness of the developer on the developer carrying member is provided on the side, and the high heat conductive member is provided on the upper casing so as to be able to contact the developer dammed by the developer regulating member. Is provided.

According to a sixth aspect of the present invention, in the developing device of the fifth aspect, the high thermal conductive member is provided with a projection for moving the blocked developer in the axial direction of the developer carrier. Is adopted.

According to the seventh aspect of the present invention, the first to sixth aspects are provided.
In the developing device according to any one of the first to third aspects, the high thermal conductive member is a flat heat pipe.

[0013] In the invention according to claim 8, claims 1 to 7 are provided.
In the developing device according to any one of the above, a second high heat conductive member is provided on an inner wall surface of the casing with which the developer contacts, and the second high heat conductive member contacts the high heat conductive member. Is adopted.

According to a ninth aspect of the present invention, in the developing device of the eighth aspect, the second high thermal conductive member is formed of a low friction material.

According to a tenth aspect of the present invention, in the developing device of the eighth aspect, the second high heat conductive member is formed of a material having anisotropy in heat conduction. .

According to an eleventh aspect of the present invention, in the developing device according to any one of the first to tenth aspects, a portion of the casing that contacts the developer is formed of a synthetic resin into a hollow structure. The configuration is adopted.

According to a twelfth aspect of the present invention, in the developing device according to one of the first to tenth aspects, a portion of the casing in contact with the developer is formed into a hollow structure by extrusion molding. The part is filled with a heat insulating material.

According to a thirteenth aspect of the present invention, in the developing device according to one of the first to twelfth aspects, there is provided an airflow generating means for generating an airflow passing through the heat radiating portion.
The configuration is adopted.

According to a fourteenth aspect of the present invention, in the developing device according to the thirteenth aspect, the heat radiating portion has a plurality of grooves through which an air flow passes, and the direction of the air flow is substantially parallel to the axial direction of the image carrier. Is adopted.

According to a fifteenth aspect of the present invention, in the developing device according to the thirteenth aspect, the heat radiating portion has a plurality of grooves through which an air flow passes, and the direction of the air flow is substantially orthogonal to the axial direction of the image carrier. To do.

According to a sixteenth aspect of the present invention, in the developing device according to one of the first to fifteenth aspects, the heat radiating portion has a Peltier element as heat exchange means. I have.

According to the seventeenth aspect, an electrostatic latent image is formed on an image carrier by an optical writing unit, the electrostatic latent image is visualized as a toner image by a developing device, and the toner image is recorded. In an image forming apparatus for transferring to a material, a configuration is adopted in which the developing device is one of the first to sixteenth aspects.

According to an eighteenth aspect of the present invention, in the image forming apparatus according to the seventeenth aspect, the heat radiating portion takes part of the heat radiation of the optical writing means.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. First, an outline of the configuration and operation of a tandem-type color copying machine as an image forming apparatus according to the present embodiment will be described with reference to FIG. The color copier 1 includes an image forming unit 1 located at a central portion of the apparatus main body.
A and a sheet feeding unit 1B located below the image forming unit 1A.
And an image reading unit 1C located above the image forming unit 1A. An intermediate transfer belt 2 having a transfer surface (expansion surface) extending in the horizontal direction is disposed in the image forming unit 1A. On the upper surface of the intermediate transfer belt 2, an image of a color complementary to the color separation color is provided. Is provided. That is, the photoconductors 3Y, 3M, 3C, and 3B as image carriers capable of carrying an image using toners of complementary colors (yellow, magenta, cyan, and black) are juxtaposed along the extended surface of the intermediate transfer belt 2. Have been.

Each of the photoconductors 3Y, 3M, 3C, 3B is constituted by a drum rotatable in the same direction (clockwise), and around the charging device 4, a charging device 4 for executing an image forming process in a rotating process. And a writing device 5 as an optical writing means, a developing device 6, a primary transfer device 7, and a cleaning device 8. The alphabet attached to each code corresponds to the color of the toner similarly to the photoconductor 3. Each of the developing devices 6 contains a respective color toner, and these color toners are oil-less compatible toners in which wax as a release agent is contained and dispersed. The intermediate transfer belt 2 is wrapped around a plurality of rollers 2A to 2C, and the photosensitive members 3Y, 3M, 3C,
A structure is provided that can move in the same direction at a position facing 3B. A roller 2C, which is different from the rollers 2A and 2B that support the extension surface, faces the secondary transfer device 9 with the intermediate transfer belt 2 interposed therebetween. In FIG. 1, reference numeral 10 indicates a cleaning device for the intermediate transfer belt 2.

The surface of the photoconductor 3Y is uniformly charged by the charging device 4Y, and an electrostatic latent image is formed on the photoconductor 3Y based on image information from the image reading unit 1C. The electrostatic latent image is visualized as a toner image by a developing device 6Y containing yellow toner, and the toner image is transferred to a primary transfer device 7Y.
As a result, primary transfer is performed on the intermediate transfer belt 2. Similar image formation is performed on the other photoconductors 3M, 3C, and 3B, except that the toner colors are different. Toner images of the respective colors are sequentially transferred onto the intermediate transfer belt 2 and superimposed. After the transfer, the toner remaining on the photoconductor 3 is removed by the cleaning device 8, and after the transfer, the potential of the photoconductor 3 is initialized by an unillustrated discharging lamp, and is prepared for the next image forming process. The secondary transfer device 9 has a transfer belt 9C that is wound around a charging drive roller 9A and a driven roller 9B and moves in the same direction as the intermediate transfer belt 2. Transfer belt 9C
Is charged by the charging drive roller 9A, a multicolor image superimposed on the intermediate transfer belt 2 or a single-color image carried on the intermediate transfer belt 2 can be transferred onto a sheet P as a recording material.

The sheet P is fed from the sheet feeding section 1B to the secondary transfer position. A plurality of sheet cassettes 1B1 in which sheets P are stacked and stored in the sheet feeding unit 1B, and sheets P stored in the sheet cassettes 1B1 are stored in the order of 1 from the top.
A paper feed roller 1B2 for separating and feeding paper one by one, a transport roller pair 1B3, a registration roller pair 1B4 positioned upstream of the secondary transfer position, and the like are provided. Paper cassette 1B1
Is stopped once by the pair of registration rollers 1B4 to correct the oblique displacement or the like, and then the timing at which the leading end of the toner image on the intermediate transfer belt 2 matches the predetermined position of the leading end in the transport direction. Is sent to the secondary transfer position by the registration roller pair 1B4. A manual feed tray 50 is provided on the right side of the apparatus main body so as to be capable of being turned upside down. After the paper P stored in the manual feed tray 50 is fed by the paper feed roller 52, the paper P passes through the paper feed path from the paper feed cassette 1B1. The sheet is sent toward the registration roller pair 1B4 by the conveyed path.

In the writing device 5, writing light is controlled by image information from the image reading section 1C or image information output from a computer (not shown), and
Writing light corresponding to image information is emitted to Y, 3M, 3C, and 3B to form an electrostatic latent image.
The image reading unit 1C includes an automatic document feeder 1C1 and a scanner 1 having a contact glass 54 as a document table.
C2 and the like. The automatic document feeder 1C1 has a configuration in which a document fed out onto the contact glass 54 can be inverted, and can scan each side of the document. The electrostatic latent image on the photoconductor 3 formed by the writing device 5 is subjected to visible image processing by the developing device 6, and is primarily transferred to the intermediate transfer belt 2. When the toner images of each color are superimposedly transferred onto the intermediate transfer belt 2, they are collectively and secondarily transferred onto the sheet P by the secondary transfer device 9. The secondary-transferred sheet P is sent to a fixing device 11, where an unfixed image is fixed by heat and pressure. The residual toner on the intermediate transfer belt 2 after the secondary transfer is removed by the cleaning device 10.

The sheet P that has passed through the fixing device 11 is selectively guided to a conveyance path toward the discharge tray 13 and a reversing conveyance path RP by a conveyance path switching claw 12 provided on the downstream side of the fixing apparatus 11. Is done. When the sheet is conveyed toward the sheet discharge tray 13, the sheet
Discharged above and stacked. When the sheet is guided to the reversing conveyance path RP, it is reversed by the reversing device 58 and is again sent to the registration roller pair 1B4.

With the above configuration, in the color copying machine 1,
An electrostatic latent image is formed on the uniformly charged photoreceptor 3 by exposing and scanning the original placed on the contact glass 54 or by image information from a computer. After the visible image processing is performed by the developing device 6, the toner image is primarily transferred to the intermediate transfer belt 2.
In the case of a single color image, the toner image transferred to the intermediate transfer belt 2 is a sheet P fed out of the sheet feeding unit 1B as it is.
Is transferred to In the case of a multicolor image, after the primary transfer is repeated and superimposed, the secondary transfer is collectively performed on the paper P. After the secondary transfer, the sheet P after the unfixed image is fixed by the fixing device 11 is discharged to the discharge tray 13,
Alternatively, the sheet is reversed and fed again to the registration roller pair 1B4.

Next, the developing device will be described in detail with reference to FIGS. 2 to 4 on behalf of the yellow developing device 6Y. The developing device 6Y includes a lower casing 18 that accommodates the developer G, an upper casing 19 that covers an upper portion of the lower casing 18, and transport screws 16 and 17 as developer agitating and transporting means that agitates and transports the developer G. And a developing roller 15 and the like as a developer carrier for receiving the developer G from the transport screw 16. An upper casing 19 above the developing roller 15 is provided with a doctor blade 20 as a developer regulating member that regulates the thickness of the developer G on the developing roller 15. Reference numeral 18 is formed of a resin having a low thermal conductivity.

The transport screws 16 and 17 are partitioned by a high thermal conductive member 22 as a partition. The transport screws 16 and 17 have a length extending in the axial direction of the photoreceptor 3Y and the developing roller 15, and are driven to rotate so as to circulate the developer G in a developer transport path where the inner side and the forward side merge. Is done. As shown in FIG. 4, a second high heat conductive member 21 is provided on the inner surface of the lower casing 18 with which the developer G contacts.
The lower end of the high heat conductive member 22 is inserted into and fixed to a concave portion 18 a formed in the center of the lower casing 18 so as to make surface contact with the second high heat conductive member 21. I have. That is, the second high heat conductive member 2
By (1), the contact area between the high thermal conductive member 22 and the developer G is substantially enlarged.

The high thermal conductive member 22 is formed of a flat heat pipe, and its upper portion is led out of the apparatus main body and bent at a substantially right angle, and a heat radiating portion 23 is formed. ). Generally, the heat pipe has a columnar shape, but a meandering heat pipe having a flat plate shape already exists. Since this flat heat pipe can be bent, the heat radiating surface can be directed in the most effective direction in the upper heat radiating portion 23. In general, a bottom heat method of heating the lower part and cooling the upper part of the heat pipe can provide the best performance, and therefore, the configuration of the present embodiment is most suitable as a configuration for heat transport.

The second high thermal conductive member 21 is formed of a material having a high thermal conductivity. Specific materials include
In addition to a metal plate or sheet, there is plating treatment on the inner surface of the lower casing 18, and a graphite sheet (for example, PG manufactured by Matsushita Electric Industrial Co., Ltd.) as a material having a high thermal conductivity.
S Graphite sheet or GRAFO made by Graphtec
IL etc.) can be used. Graphite not only has a high thermal conductivity, but also has anisotropy in thermal conductivity, and the thermal conductivity in the plane direction is much larger than the thermal conductivity in the thickness direction. The heat transfer is reduced, and external heat effects can be prevented. Furthermore, since graphite has a feature that the surface has a very small coefficient of friction, if a graphite sheet is used for the contact surface of the developer G, the flow speed of the developer G on the contact surface increases, and heat transfer is promoted. You. Further, in the present embodiment, the transport screw 16 and the transfer screw 16 are arranged such that the liquid level of the developer G becomes higher toward the high heat conductive member 22 as a partition.
17 is driven to rotate. Thereby, it is possible to increase the area of the high heat conductive member 22 that directly transfers heat to the developer G.

As shown in FIG. 3, the heat dissipating portion 23 has a large number of heat dissipating fins 23a.
A groove (flow path) through which an air flow passes is formed between 3a.
The overall configuration is a flow path that penetrates the developing device 6 for each color. A blower fan (not shown) is provided on the left side of FIG. 1 as airflow generating means, and generates airflow from left to right on the lower surface of the writing device 5 in the figure. The airflow passes through the plurality of grooves so as to be orthogonal to the axial direction of the photoconductor 3Y. Heat is taken from each of the radiating fins 23a by the passage of the airflow, and heat is radiated. Therefore, the heat generated by the stirring of the developer G by the transport screws 16 and 17 is guided to the outside of the apparatus main body (boundary portion with the writing apparatus 5) by the high heat conductive member 22.
The heat is radiated by the radiator 23. When radiating fins are also arranged on the writing device 5 side within a range where the optical path is not interrupted (in this case, it is desirable that the fins have the same shape as viewed from the air blowing direction or have a positional relationship shifted at regular intervals). The flow path is consistent for all colors. In this case, the flow path is the developing roller 1
Since the cross section is long in the axial direction of No. 5, the cross-sectional area can be increased, and cooling can be effectively performed by using a cross-flow fan to push air. Developing device 6 described above
The configuration in Y is the same in the other developing devices 6M, 6C, and 6B.

Next, a second embodiment will be described with reference to FIG. The same parts as those in the above-described embodiment are denoted by the same reference numerals, and the description of the configuration and the function already described is omitted unless necessary. Further, only the main part will be described (the same applies to other embodiments described below). Heat radiator 24 in the present embodiment
Have radiating fins 24a extending parallel to the axial direction of the developing roller 15. Thus, a groove (air flow path) parallel to the axis of the developing roller 15 is formed. The cross-sectional area of the airflow channel is relatively small, and the pressure loss is relatively large. An independent flow path is provided for each color, and when there is an image forming unit that does not operate during single-color operation, unnecessary blowing can be suppressed. In addition, since air can be blown by the suction airflow, there is no fear of contamination inside the apparatus due to scattered toner even if airtightness of the flow path is not taken into account.

Next, a third embodiment will be described with reference to FIG. The upper portion of the high heat conductive member 22 in the present embodiment extends substantially vertically, and the heat radiating portions 25 are provided on both surfaces of the high heat conductive member 22. Each heat radiating portion 25 has a heat radiating fin 25 a extending parallel to the axial direction of the developing roller 15. Thus, a groove (air flow path) parallel to the axis of the developing roller 15 is formed. The function of the flow path is the same as the configuration shown in FIG.

Next, a fourth embodiment will be described with reference to FIG. The heat radiating section 26 in the present embodiment is almost the same as the configuration shown in FIG. 3, but a developing unit (developing device)
The radiation fin 26b located at the end (front side) in the mounting / removing direction is longer (higher) than the other radiation fins 26a. Specifically, the length of the radiation fin 26b is set to a length that can maintain airtightness with the frame of the writing device 5. A radiating fin 5a is formed in the writing device 5 at a depth in the developing unit attaching / detaching direction, and the length of the harmful radiating fin 5a is set to a length that can maintain airtightness with the radiating portion 26. . The blowing direction (the direction of airflow) is orthogonal to the developing unit attaching / detaching direction. Generally, the developing unit is configured to be detachable for maintenance, and a gap between members is required for maintenance work. However, in order to increase the effect of air cooling,
Since airtightness as a flow path is required, the writing device 5
By intermingling with the heat radiation fins 5a on the side (particularly with the heat radiation fins on the outside), it is possible to make it difficult for the air flow on the outer wall of the heat radiation part 26 to flow and to improve the airtightness.

Next, a fifth embodiment will be described with reference to FIGS. In the present embodiment, the heat radiating fins 5c extending in parallel with the axial direction of the developing roller 15 are also formed on the writing device 5 side corresponding to the heat radiating portion 24. The radiation fins 5b at both ends are set longer than the other radiation fins 5c.
a and the radiating fins 5c are intricate, and the radiating fins 5b at both ends improve the airtightness of the outer wall of the radiating portion 24, making it difficult for airflow to flow. In particular, the airtightness of the flow path can be improved by reducing the space between the heat radiation fins 5b at both ends.

Next, a sixth embodiment will be described with reference to FIG. In the present embodiment, the upper part of the high thermal conductive member 22 is provided substantially vertically, and the heat radiating part 27 is provided on this upper part. The radiator 27 is a Peltier module 27
a, and a plurality of radiating fins 27 b extending parallel to the axial direction of the developing roller 15. Peltier module 2
7a has a built-in Peltier element, and radiation fins 27b
It is integrated with. Since the Peltier element forcibly carries out heat transport by external energy, there is an advantage that the degree of freedom in material selection and shape design of the high heat conductive member 22 is improved.

Next, a seventh embodiment will be described with reference to FIGS. In the present embodiment, the high heat conductive member 22 is provided so that approximately half of the thickness of the lower casing 18 on the inner wall side is provided, and the partition wall 28 is provided with the high heat conductive member 22 as the bottom surface. The upper portion of the high thermal conductive member 22 extends substantially vertically, and is provided with a heat radiating portion 24. The outside of the high heat conductive member 22 is covered with a thickness that is approximately half the thickness of the lower casing 18, and as a result, the material of the lower casing 18 is covered with a member having heat insulation. A high heat conductive member such as a graphite sheet may be attached to the surface of the partition wall 28. In this case, the developer G and the high heat conductive member directly transfer heat, so that the efficiency of heat reception is high. The upper part of the high thermal conductive member 22 can be arranged horizontally without being upright if space permits. Also,
As shown in FIG. 12, a graphite sheet or the like can be attached to the outer periphery of the high heat conductive member 22 to increase the effective area of heat reception. In the case of FIG. 12, heat transfer in the thickness direction is required, but if heat transfer in the plane direction is used, it can be realized by folding inward.

Next, an eighth embodiment will be described with reference to FIG. The present embodiment is characterized in that the lower casing 29 has a heat insulating structure having a hollow portion 29a. Generally, resin is a poor conductor of heat, but the heat insulation can be further improved by the presence of the hollow portion 29a. As a molding method, for example, a gas assist method can be used. Heat insulation can be obtained by the thermal conductivity of the material (resin and air) and the thermal resistance of the interface. Due to this heat insulating property, the influence of heat from outside the developing device 6Y can be suppressed with high accuracy. In general, extrusion molding of aluminum is often used as a lower casing of a developing unit, but even in this case, it is possible to improve heat insulation by thinning ribs and filling a hollow portion with a material having low thermal conductivity. it can.

Next, a ninth embodiment will be described with reference to FIG. In the present embodiment, the high heat conductive member 22 is provided on the upper casing 19, and the upper casing 1
The portion fixed to 9 is provided so as to be able to contact the developer G blocked by the doctor blade 20. Furthermore,
A plurality of protrusions 31 having a shape for moving the blocked developer G in the axial direction of the developing roller 15 are provided on a portion fixed to the upper casing 19. Heat radiator 24
Is covered with a duct 30 to ensure airtightness. In addition, the outer surface of the lower casing 18 is covered with a heat insulating material 32 to improve heat insulation. The protrusion 31 is a rectifying plate that also serves as a heat receiving fin, and promotes an increase in the heat receiving area and movement of the developer G in the axial direction of the developing roller 15. In this embodiment, since the heat receiving portion and the heat radiating portion 24 are close to each other, there is an advantage that the degree of freedom in selecting the material of the high heat conductive member 22 is large.

Next, a tenth embodiment will be described with reference to FIG. In the present embodiment, the lower end of the high thermal conductive member 22 is provided on the doctor blade 20 so as to come into contact with the developer G that is blocked. The periphery of the heat radiating section 24 is covered by a duct 33. Also in this embodiment, since the heat receiving portion and the heat radiating portion 24 are close to each other, there is an advantage that the degree of freedom in selecting the material of the high heat conductive member 22 is large.

Although the above embodiments have been described with reference to a tandem type image forming apparatus, the present invention can be similarly applied to image forming apparatuses other than the tandem type.

[0046]

According to the invention of claim 1 or 17,
In a developing device for supplying a developer contained in a casing to an image carrier by a developer carrier, a high heat conductive member having high thermal conductivity is provided inside the device so that the developer contacts the developing device. Since the heat radiating portion is formed by extending the conductive member out of the apparatus, the developer that generates the most heat in the developing device can be efficiently radiated outside the apparatus away from the apparatus. Layout restrictions caused by cooling can be reduced, and design flexibility can be improved.

According to the second or seventeenth aspect of the present invention, since the partition for circulating the developer is provided and the partition is made of a high heat conductive member, the configuration in the developing device is complicated. The heat radiation function (cooling function) can be enhanced without any need.

According to the third or 17th aspect of the present invention, there is provided a developer agitating / conveying means for agitating / conveying the developer, wherein the developer agitating / conveying means is provided with a liquid level of the developer toward the high heat conductive member. Is increased so that the effective area of heat reception can be increased, and the heat transfer function can be enhanced by promoting heat transfer.

According to the invention as set forth in claim 4 or claim 17, the casing has a lower casing in which the developer is accommodated, and an upper casing which covers the upper part of the lower casing, and at least a part of the lower casing has high heat. Since it is made of a conductive member and the outside of the high thermal conductive member is covered with a heat insulating member, the influence of heat from the outside can be suppressed, and the heat radiation function can be further enhanced.

According to the fifth or 17th aspect of the present invention, the casing has a lower casing in which the developer is accommodated, and an upper casing that covers the upper part of the lower casing, and the developer carrying member is provided on the upper casing side. Since a developer regulating member for regulating the thickness of the upper developer is provided, and the high heat conductive member is provided on the upper casing so as to be able to contact the developer dammed by the developer regulating member. ,
Cooling can be performed at a position close to the heat radiating portion, and the degree of freedom in designing members can be increased.

According to the sixth or 17th aspect of the present invention, the high heat conductive member is provided with the projection for moving the blocked developer in the axial direction of the developer carrier, so that the heat receiving member is provided. It is possible to simultaneously promote the cooling of the developer and the rectification by increasing the area.

According to the seventh or seventeenth aspect of the present invention, since the high heat conductive member is a flat heat pipe, the heat radiation efficiency can be improved with a simple and low cost configuration.

According to the present invention, the second high heat conductive member is provided on the inner wall surface of the casing in contact with the developer, and the second high heat conductive member and the high heat conductive member are provided. Since it is configured to be in contact, the effective heat receiving area can be increased, and the heat radiation efficiency can be increased.

According to the ninth or seventeenth aspect of the present invention, since the second high heat conductive member is formed of a low friction material, the heat transfer can be enhanced by improving the flow speed of the developer. And the heat radiation efficiency can be increased.

According to the invention of claim 10 or 17,
Since the second high heat conductive member is formed of a material having anisotropy in heat conduction, the direction of heat transfer can be controlled, so that the heat dissipation function can be improved and the heat insulation function can be obtained.

According to the eleventh or seventeenth aspect,
The part of the casing that comes into contact with the developer has a hollow structure made of synthetic resin, so the low thermal conductivity of the resin and the thermal resistance of the boundary surface of the hollow part can be used, and the external heat effect And the heat radiation efficiency can be increased.

According to the invention of claim 12 or 17,
Since the portion of the casing that contacts the developer is formed into a hollow structure by extrusion molding, and the hollow portion is filled with a heat insulating material, a high heat insulating function can be obtained using the conventional structure. .

According to the invention of claim 13 or 17,
Since the airflow generating means for generating the airflow passing through the heat radiating section is provided, the heat radiating action of the heat radiating section can be enhanced, and the heat radiation efficiency can be enhanced.

According to the invention of claim 14 or 17,
Since the heat radiating portion has a plurality of grooves through which the air flow passes, and the direction of the air flow is substantially parallel to the axial direction of the image carrier, when there are a plurality of developing devices such as a tandem type, Optimal air blowing conditions can be given for the operating conditions. In addition, since suction cooling is possible, it is possible to suppress in-machine contamination due to scattered toner.

According to the invention of claim 15 or 17,
Since the heat radiating portion has a plurality of grooves through which the air flow passes, and the passage direction of the air flow is substantially perpendicular to the axial direction of the image carrier, the flow path cross-sectional area can be relatively large, and the pressure loss can be suppressed. Can be.

According to the invention of claim 16 or 17,
Since the heat radiating portion has a Peltier element as the heat exchange means, the degree of freedom in selecting the material of the highly heat conductive member and designing the shape can be increased.

According to the eighteenth aspect of the present invention, since the heat radiating portion plays a part of the heat radiation of the optical writing means, the two units can be cooled with a simple configuration by consolidating the heat radiating portions. The cooling efficiency in the image forming apparatus can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic front view of a color copying machine as an image forming apparatus according to a first embodiment of the present invention.

FIG. 2 is a schematic sectional view of a developing device corresponding to a yellow image.

FIG. 3 is a perspective view of a heat radiating unit.

FIG. 4 is an exploded view showing a contact relationship between a high heat conductive member and a second high heat conductive member.

FIG. 5 is a perspective view of a heat radiating unit according to a second embodiment.

FIG. 6 is a perspective view of a heat radiating unit according to a third embodiment.

FIG. 7 is a side view of a heat radiating unit according to a fourth embodiment.

FIG. 8 is a perspective view of a heat radiating unit according to a fifth embodiment.

FIG. 9 is a front view of a heat radiating unit according to a fifth embodiment.

FIG. 10 is a schematic sectional view of a developing device according to a sixth embodiment.

FIG. 11 is a schematic sectional view of a developing device according to a seventh embodiment.

FIG. 12 is a front view of a main part of a configuration for enlarging a heat receiving area of a high heat conductive member according to a seventh embodiment.

FIG. 13 is a schematic sectional view of a developing device according to an eighth embodiment.

FIG. 14 is a schematic sectional view of a developing device according to a ninth embodiment.

FIG. 15 is a schematic sectional view of a developing device according to a tenth embodiment.

[Explanation of symbols]

 G Developer 5 Optical writing means 15 Developing roller 16 and 17 as developer carrier 16 Conveying screw as developer stirring and conveying means 18 Lower casing 19 Upper casing 20 Doctor blade as developer regulating member 21 Second high thermal conductivity Member 22 High thermal conductive member 23, 24, 25, 26, 27 Heat radiating part 28 Partition wall 31 Projection

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H05K 7/20 H05K 7/20 FHRS G03G 15/08 507E

Claims (18)

[Claims] 1. A developing device for supplying a developer contained in a casing to an image carrier by a developer carrier, wherein a high thermal conductive member having high thermal conductivity is provided inside the device so that the developer contacts the developer. And a heat radiating portion formed by leading the high heat conductive member out of the device. 2. The developing device according to claim 1, further comprising a partition for circulating the developer, wherein the partition is the high heat conductive member. 3. The developing device according to claim 1, further comprising a developer agitating / conveying means for agitating / conveying the developer, wherein the developer agitating / conveying means is provided with a liquid level of the developer toward the high heat conductive member. The developing device is driven so as to rise. 4. The developing device according to claim 1, wherein said casing has a lower casing in which a developer is accommodated, and an upper casing which covers an upper part of said lower casing, wherein at least a part of said lower casing is said A developing device formed of a high heat conductive member, wherein the outside of the high heat conductive member is covered with a member having heat insulating properties. 5. The developing device according to claim 1, wherein the casing has a lower casing in which a developer is stored, and an upper casing that covers an upper portion of the lower casing. A developer regulating member for regulating the thickness of the developer on the body is provided, and the high heat conductive member is provided on the upper casing so as to be able to contact the developer blocked by the developer regulating member. Characteristic developing device. 6. The developing device according to claim 5, wherein the high thermal conductive member is provided with a projection for moving the blocked developer in the axial direction of the developer carrier. Developing device. 7. The developing device according to claim 1, wherein the high heat conductive member is a flat heat pipe. 8. The developing device according to claim 1, wherein a second high heat conductive member is provided on an inner wall surface of the casing with which the developer contacts, and the second high heat conductive member is provided. A developing member wherein the conductive member and the high thermal conductive member are in contact with each other. 9. The developing device according to claim 8, wherein the second high heat conductive member is formed of a low friction material. 10. The developing device according to claim 8, wherein the second high heat conductive member is formed of a material having anisotropy in heat conduction. 11. The developing device according to claim 1, wherein a portion of the casing that contacts the developer is formed of a synthetic resin into a hollow structure. . 12. The developing device according to claim 1, wherein a portion of the casing in contact with the developer is formed into a hollow structure by extrusion molding, and the hollow portion is filled with a heat insulating material. A developing device. 13. The developing device according to claim 1, further comprising an airflow generating means for generating an airflow passing through said heat radiating portion. 14. A developing device according to claim 13, wherein said heat radiating portion has a plurality of grooves through which an air flow passes, and a direction in which said air flow passes is substantially parallel to an axial direction of said image carrier. Developing device. 15. A developing device according to claim 13, wherein said heat radiating portion has a plurality of grooves through which an air flow passes, and a direction in which said air flow passes is substantially orthogonal to an axial direction of said image carrier. Developing device. 16. The developing device according to claim 1, wherein said heat radiating section has a Peltier element as heat exchange means. 17. An image forming method for forming an electrostatic latent image on an image carrier by optical writing means, visualizing the electrostatic latent image as a toner image by a developing device, and transferring the toner image to a recording material. An image forming apparatus, wherein the developing device is the one according to any one of claims 1 to 16. 18. An image forming apparatus according to claim 17, wherein said heat radiating portion performs a part of heat radiation of said optical writing means.