JPH05165355A - Image forming device - Google Patents

Abstract

PURPOSE:To efficiently recover the heat of a heating member in a device without noise and to protect a member which must be shielded. CONSTITUTION:A heat pipe 26 provided with a heat entering part 29 and a heat exiting part 30 is included in an electrophotographic image forming device provided with the heating member 21 and the member to be shielded 22 which must be thermally shielded from the member 21. The heat entering part 29 is arranged between the members 21 and 22, and the heat exiting part 30 is arranged at a part in the device, where temperature is low.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a printer or a copying machine using an electrophotographic system.

[0002]

2. Description of the Related Art The structure of a conventional printer using the electrophotographic method is shown in FIG.
Is a photosensitive drum (photoreceptor) 2, a transfer roll 3, a fixing device 4, a removable paper tray 5, a paper insertion portion 6,
The pick roller 7 and the standby roller 8 are provided. The photosensitive drum 2 is incorporated in a process cartridge 9 together with a charger, a developing device, a static eliminator, and a cleaner, which are not shown, and the process cartridge 9 is removable (replaceable).

Upon recording, the photosensitive drum 2 is rotated clockwise as indicated by an arrow to uniformly charge the surface of the photosensitive drum 2 by a charger, and then the surface is provided inside the apparatus (not shown). The exposure unit exposes the pattern in accordance with the image information to form an electrostatic latent image. This electrostatic latent image is developed by the developing device and becomes a toner image.

On the other hand, the paper stored in the predetermined paper tray 5 is delivered by the pick roller 7 and is sent to the transfer portion A by the standby roller 8 in time with the formation of the toner image on the surface of the photosensitive drum 2. Be done. Then, in the transfer portion A, the transfer roller 3 transfers the toner image on the surface of the photosensitive drum 2 to the sheet. After that, the paper is sent to the fixing unit B, where a toner image is formed by the fixing device 4 including the heat roll 10 and the pressure roll 11. The paper, which has been fixed, is discharged to the stacker 1 by the discharge roll 12.
It is discharged to 3. When the paper is manually inserted, the paper is inserted using the paper insertion unit 6.

[0005]

In the printer device having the above-described structure and operation, the photoconductor or the developer in the developing device is heated by the heat of the fixing device, the power supply, the motor, the printed circuit board of the driving circuit, and the like. It has a structure that can be heated, and there were severe restrictions on the operating environment temperature. In order to improve this, a method of cooling the photoconductor, developing device, etc. with a fan is adopted. In this method, the fan generates noise (mainly wind noise), and this noise improves the office environment in recent years. Has become a new issue with the movement.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image forming apparatus capable of efficiently collecting the heat of a heat generating member in the apparatus without noise and protecting the member to be shielded.

[0007]

In order to achieve the above object, the present invention provides an electrophotographic image forming apparatus including a heat-generating member and a shielding member that needs to be thermally shielded from the heat-generating member. A heat pipe having a heat-discharging part and a heat-discharging part is provided between the heat-generating member and the shielding member, and the heat-dissipating part of the heat pipe is provided in the device. The configuration (first configuration) is characterized in that it is arranged in a portion having a low temperature.

In the image forming apparatus having the first structure, the heat input section is formed of a shield plate that partitions the heat generating member and the shield member (second structure).

In addition, in the image forming apparatus having the above-mentioned first structure or second structure, a heat insulating material is added between the heat input portion and the shielding member (third structure). To do.

[0010]

The heat of the heat generating member is recovered in the heat input portion between the heat generating member and the shield member, and is efficiently dissipated from the heat output portion arranged at a low temperature portion in the apparatus. Further, in the case of the second configuration, it is possible to block the movement of heat due to radiation and convection from the heat-generating member to the shield member, and the heat recovery effect is further improved. It is further improved by adding the heat insulating material of the constitution. The heat generating member may be, for example, a fixing device, and the shielding member may be a photoconductor.

[0011]

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

FIG. 1 is a side view showing the main structure of the image forming apparatus of this embodiment. In the figure, 21 is a fixing device (heating member), 22 is a photoconductor (shielding member), 23 is a developing device, and 24 is a developing device. Is a transfer roll, 25 is a discharge roll, and 26 is a heat pipe. The above-mentioned members except the heat pipe 26 are the same as those in the conventional apparatus shown in FIG. 4, and the fixing device 21 includes a heat roll 27 and a pressure roll 28.

The heat pipe 26 has a heat input part 29 and a heat output part 30, as shown in detail in FIG. The heat input unit 29 includes a plurality of fins 31 and is arranged between the heat roll 27 and the photoconductor 22. The heat output part 30 includes a plurality of fins 32 and is arranged in a low temperature portion in the device. As a characteristic of the temperature distribution inside the electrophotographic image forming apparatus such as a printer or a copying machine, the temperature difference is large, but the air flow is interrupted by the conveyance path and the like and cannot be increased so much. Since the upper part of the fixing device 21 is near the discharge port and has a low temperature, the heat output part 30 is arranged in this part in this figure.

Since the heat pipe 26 is arranged as described above, the heat of the heat roll 27 is recovered by the heat input part 29 and is arranged in the low temperature part of the apparatus.
Is efficiently dissipated from. Therefore, the photoconductor 22 can be thermally shielded and protected.

FIG. 3 shows another example of the heat pipe. The heat pipe 41 includes a heat input section 42 and a heat output section 30. The heat input section 42 includes an aluminum shielding plate 43, which partitions the heat roll 27 and the photoconductor 22. In this case, the heat transfer from the heat roll 27 to the photoconductor 22 and the transfer of heat to the member requiring shielding due to convection can be blocked, and the thermal shield effect of the photoconductor 22 is further improved. The size of the shielding plate 43 is set so that a sufficient shielding effect can be obtained.

In the case of any of the examples shown in FIGS. 2 and 3,
The above effect can be further improved by adding a heat insulating material (not shown) between the heat input section and the photoconductor.

[0017]

As described above, according to the present invention, the heat from the heat generating member is recovered by the heat input portion and is efficiently radiated from the heat output portion. Can be shielded and protected. Further, if the heat input portion is formed of a shield plate and the heat shield member and the shield member are partitioned by the shield plate, the transfer of heat to the shield member due to radiation and convection can be blocked, which is more effective. Target. further,
If a heat insulating material is added between the heat input section and the member requiring shielding, the above effect is further improved.

[Brief description of drawings]

FIG. 1 is a side view showing a main structure of an image forming apparatus according to an exemplary embodiment of the present invention.

FIG. 2 is a perspective view showing details of a main part of FIG.

FIG. 3 is a perspective view showing another example of the heat pipe of FIG.

FIG. 4 is a side view showing an outline of the structure of a conventional printer device.

[Explanation of symbols]

 21 fixing device (heating member) 22 photoconductor (shielding member required) 23 developing device 26,41 heat pipe 29,42 heat input part 30 heat output part 43 shield plate

Claims (3)

[Claims] 1. An electrophotographic image forming apparatus comprising a heat-generating member and a shield-requiring member which is desired to be thermally shielded from the heat-generating member, wherein a heat pipe having a heat input section and a heat output section is provided. An image formation characterized in that the heat input part of the heat pipe is arranged between the heat generating member and the shielding member, and the heat output part of the heat pipe is arranged at a low temperature portion in the apparatus. apparatus. 2. The image forming apparatus according to claim 1, wherein the heat input portion is formed of a shield plate that partitions the heat generating member and the shield member. 3. The image forming apparatus according to claim 1, wherein a heat insulating material is added between the heat input section and the shield member.