JPH117218A - Cooling unit for image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the cooling unit of an image forming device constituted so that cooling performance can be enhanced without increasing noise and power consumption and making the whole device large-sized. SOLUTION: A sheet cooling roller 51 is constituted of a sheet carrying part 511 and a heat radiation part 512 formed to be thinner than the carrying part 511. Then, a heat radiating fin 52 abuts on the heat radiation part 512. The carrying part 511 is required to be provided with fixed thickness or more but the heat radiation part 512 on which the fin 52 abuts need not be provided with the thickness like the carrying part 511. By making the heat radiation part 512 thinner than the carrying part 511, heat moved and uniformly distributed at high temperature in the heat pipe (sheet cooling roller 51) when a recording sheet is cooled is quickly transmitted to the fin 52 and radiated in air.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling apparatus for an image forming apparatus such as a laser beam printer, a digital copying machine, and a plain paper facsimile, and more particularly, to a technique for cooling a recording sheet.

[0002]

2. Description of the Related Art As one of devices for cooling a heat source, there is a heat transfer device for transmitting heat to the outside by using a rotary heat pipe. However, in the prior art, a plurality of heat pipes are usually provided at least at one end of the heat pipe. And a cooling fan for supplying cooling air to the radiating fins.

[0003] Laser beam printers, digital copiers,
As a recording sheet cooling device of an image forming apparatus used as an OA device such as a plain paper facsimile, for example, Japanese Utility Model Application
In some cases, a cooling device for cooling a recording sheet is provided downstream of a heat fixing unit of an image forming apparatus, such as a recording sheet cooling device of an image forming apparatus disclosed in Japanese Patent No. 46451/46.

The paper cooling system using this apparatus uses a cooling roller made of a heat pipe. In this system, a radiating fin 52 is provided at one end of a heat pipe 51 as shown in FIG. A cooling fan 54 for supplying cooling air is provided. In FIG. 2, reference numeral 53 denotes a transport belt for transporting paper, and 55 denotes a recording sheet (paper).

[0005]

In an image forming apparatus such as a laser beam printer, a digital copying machine, and a plain paper facsimile, an improvement in output speed of an image forming result is one of the main objectives of processing speed. For this purpose, it is necessary to improve the cooling performance of the recording sheet. However,
In order to improve the cooling performance with the conventional recording sheet cooling method as described above, it is necessary to increase the rotation speed of the cooling fan and increase the size of the device. There was a problem that conversion was inevitable.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and can improve the cooling performance without increasing noise and power consumption and without increasing the size of the entire apparatus. An object of the present invention is to provide a cooling device for an image forming apparatus.

[0007]

In order to achieve the above object, a cooling apparatus for an image forming apparatus according to the present invention comprises a heat pipe for conveying a recording sheet discharged from a heat fixing section of the image forming apparatus while cooling the recording sheet. Wherein the heat pipe comprises a heat radiating portion provided with a heat radiating member at at least one end of the heat pipe and a sheet conveying portion for conveying the recording sheet, and the pipe thickness of the heat radiating portion is set to the pipe thickness of the sheet conveying portion. It is characterized by being formed thinner.

In the above-mentioned cooling device, a cooling fan for supplying cooling air is provided at a stage preceding the heat radiating portion. You may comprise so that the ventilation opening which takes in air or discharges air outside may be provided. Further, in the cooling device, a cooling fan for supplying cooling air may be provided in a stage preceding the heat radiating unit, and the heat radiating unit and the cooling fan may be located outside the image forming apparatus main body.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing a schematic configuration of an image forming apparatus provided with a recording sheet cooling device according to the present invention. The image forming device 10 includes a sheet feeding unit 1, an image forming unit 2, a heat fixing unit 3, , A double-sided section 4 and a cooling device 5. Some types of image forming apparatuses do not have a double-sided portion, and the image forming apparatus to which the cooling device of the present invention is applied is not limited to the configuration illustrated in FIG.

The cooling device 5 is installed downstream of the heat fixing unit 3, and cools the recording sheet that has passed through the heat fixing unit 3 so that the recording sheet is discharged downstream of the heat fixing unit 3 and the double-sided stack unit 42. The toner blocking and the temperature rise of the photoconductor in the image forming unit 2 are prevented.

When the image forming apparatus 10 is set to the double-sided image forming mode, the double-sided section 4 reverses the recording sheet on which single-sided copying has been performed by rotating the sheet feeding roller 41 clockwise, and stacks the sheet on the stacking section 42. Then, after stacking the set number of recording sheets, the sheet feeding roller 41 is rotated counterclockwise to re-feed the image forming unit 2. Some types of image forming apparatuses do not have a double-sided portion (ie, do not have a double-sided image forming mode).

FIG. 2 is a view showing an example of the external configuration of the cooling device 5 according to the first embodiment. The cooling device 5 is a sheet cooling roller made of a heat pipe (hereinafter, sheet cooling roller).
51, a heat radiation fin 52 provided at at least one end of the sheet cooling roller 51, a transport belt 53 and a cooling fan 54.
When heat is taken from the recording sheet 55 at the nip portion of the conveyor belt 53 with the heat transfer sheet 1, the heat instantaneously becomes uniform in the sheet cooling roller 51. Here, by supplying cooling air from the cooling fan 54 to the radiating fins 52 provided in the radiating portion of the sheet cooling roller 51, heat taken from the recording sheet 55 is radiated into the air through the radiating fins 52.

In the above embodiment, the sheet cooling roller 51 is disposed above the recording sheet 55 as shown in FIG. 3A. However, as shown in FIG. May be arranged below the recording sheet 55. Further, in the above-described embodiment, the transport belt 53 is used for the cooling device 5, but as shown in FIG. 3C, the cooling device 5 is configured by using another unit such as a rubber roller 56 instead of the transport belt. May be. In FIG. 3, reference numeral 57 denotes a guide plate for a recording sheet conveyance path.

FIG. 4 is a sectional view showing the structure of an embodiment of the sheet cooling roller 51 which is a main part of the cooling device according to the present invention. In FIG. 4, the sheet cooling roller 51 includes a sheet conveying section 511 and a heat radiating section 512 formed to be thinner than the sheet conveying section 511.
2 are in contact.

Here, the sheet conveying section 511 needs to have a certain thickness or more in order to convey the recording sheet 55 due to strength and accuracy constraints.
The heat dissipating section 512 with which the sheet abuts does not require as thick a pipe as the sheet conveying section 511. Therefore, by making the thickness of the pipe of the heat radiating section 512 smaller than that of the sheet conveying section 511, high-temperature uniform heat in the heat pipe (the sheet cooling roller 51) is quickly transmitted to the heat radiating fins 52. That is, the heat transfer efficiency of the heat radiating section 512 is improved by making the thickness of the heat radiating section 512 smaller than that of the sheet conveying section 511, and as a result, the cooling performance of the recording sheet is improved.

The portion where the thickness of the sheet cooling roller 51 is changed (at the boundary between the sheet conveyance 511 and the heat radiating portion 512, FIG. 4).
4A is not limited to the stepping as shown in FIG. 4A, and can be formed in various shapes (for example, FIGS. 4B and 4B).
As shown in a partially enlarged view of FIG. 4C, the sheet is formed so as to be gradually thinned from the sheet conveyance 511 toward the heat radiating portion 512 (FIG. 4B), or the boundary is formed in an R shape (FIG. 4B). 4 (c)) etc.).

FIG. 5 is a cross-sectional plan view showing a configuration example of a second embodiment of the cooling device 5. The cooling device 5 described in the first embodiment is provided outside the image forming apparatus 10. This is an example in which the cooling air is supplied to the cooling fins 52.
5, the rear cover 11 of the image forming apparatus 10
1 and 112, a cooling air passage (duct) 113 is formed inside the rear cover 11, and a radiation fin 52 attached to a heat radiation portion 512 of a heat pipe (sheet cooling roller 51) protrudes into the passage 113. In addition, a cooling fan 54 is installed at the preceding stage.

By operating the cooling fan 54,
The outside air taken in from the ventilation port 111 is sucked in, is cooled by the cooling fan 54, takes heat from the radiation fins 52 protruding into the cooling air passage 113, and radiates heat to the outside from the ventilation port 112. Generally, the temperature of the air outside the machine is lower than the temperature of the air inside the machine, so that the cooling capacity is improved. Further, power consumption is small.

FIG. 6 is a plan sectional view showing a configuration example of a third embodiment of the cooling device 5, and includes the cooling fins 52 and the cooling fans 54 in the cooling device 5 described in the first embodiment. This is an example in which is disposed outside the device. In FIG. 6, an auxiliary cover 12 is provided outside the rear cover 11 of the image forming apparatus 10, and ventilation holes 122,
121, the inside of the auxiliary cover 12 is used as a passage 114 for cooling air, and a heat pipe (sheet cooling roller 5
The radiating fins 52 attached to the radiating portion 512 of 1) are protruded, and a cooling fan 54 is installed at a preceding stage thereof.

By operating the cooling fan 54,
The outside air taken in from the ventilation port 121 is sucked, cooled by the cooling fan 54, takes heat from the radiation fins 52 protruding into the cooling air passage 114, and radiates heat to the outside from the ventilation port 122. By arranging the cooling fins 52 and the cooling fan 54 outside the machine in this way, air outside the machine that is lower than the temperature of the air inside the machine can be reliably supplied to the cooling fan 54 and cooled by the cooling fan 54. Since air can be supplied to the cooling fins 52, the cooling capacity is further improved.

[0021]

As described above, according to the present invention, the thickness of the heat radiating fin mounting portion (heat radiating portion) of the heat pipe (sheet cooling roller) is made thinner than the other portions (sheet conveying portion). When the recording sheet is cooled, the heat is transferred to the heat pipe, and the heat uniformly distributed at high temperature in the heat pipe is quickly transmitted to the radiation fins 52. Thereby, the heat transfer efficiency of the heat radiating portion is improved, and as a result, the cooling performance of the recording sheet is improved.

Further, a ventilation opening is provided in a rear cover of the image forming apparatus so as to supply air outside the apparatus of the image forming apparatus to the cooling fins, a cooling air passage is formed inside the cover, and a heat radiating portion of a heat pipe is formed therein. By projecting the attached radiating fins and installing a cooling fan in front of it, air outside the machine lower than the inside of the machine is sucked in from the ventilation holes, and further cooled by the cooling fans to take heat from the radiating fins. Heat is radiated to the outside, improving the cooling capacity,
Low power consumption.

Further, the cooling fin 52 and the cooling fan 5
4 is arranged outside the machine, air outside the machine lower than the temperature of the air inside the machine can be reliably supplied to the cooling fan, and the air cooled by the cooling fan is supplied to the cooling fins. As a result, the cooling capacity is further improved.

Therefore, according to the cooling system of the present invention, the cooling performance can be improved without increasing the number of rotations of the cooling fan and increasing the size of the device, so that noise and power consumption do not increase. In addition, there is no need to increase the size of the cooling device.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a schematic configuration of an image forming apparatus including a recording sheet cooling device according to the present invention.

FIG. 2 is a diagram illustrating an example of an external configuration of the cooling device according to the first embodiment.

FIG. 3 is an explanatory diagram of an arrangement example of a heat pipe (sheet cooling roller).

FIG. 4 is a cross-sectional view showing a configuration of an embodiment of a sheet cooling roller which is a main part of a cooling device according to the present invention.

FIG. 5 is a plan cross-sectional view illustrating a configuration example of a cooling device according to a second embodiment.

FIG. 6 is a plan cross-sectional view illustrating a configuration example of a cooling device according to a second embodiment.

[Explanation of symbols]

 Reference Signs List 5 cooling device 10 image forming device 51 heat pipe 52 heat radiating fin (heat radiating member) 54 cooling fan 111, 112 ventilation port 511 sheet conveying portion 512 heat radiating portion

Claims (3)

[Claims] 1. A cooling device comprising a heat pipe for conveying a recording sheet discharged from a heat fixing unit of an image forming apparatus while cooling the heat sheet, wherein the heat pipe is provided with a heat radiating member at at least one end of the heat pipe. A cooling device for an image forming apparatus, comprising: a sheet conveying portion for conveying a recording sheet; and a pipe having a heat radiating portion formed to be thinner than a pipe thickness of the sheet conveying portion. 2. A cooling fan for supplying cooling air at a stage preceding the heat radiating portion, wherein the heat radiating portion and the cooling fan are positioned inside the image forming apparatus main body, and air is taken into the image forming apparatus main body from outside. 2. The cooling device for an image forming apparatus according to claim 1, further comprising a ventilation port for discharging air to the outside. 3. The image according to claim 1, further comprising a cooling fan that supplies cooling air at a stage preceding the heat radiating unit, wherein the heat radiating unit and the cooling fan are located outside the image forming apparatus main body. Cooling device for forming equipment.