JP2542935Y2 - Recording sheet cooling device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording sheet cooling device in an image forming apparatus such as a copying machine having a heat fixing unit.

2. Description of the Related Art In an image forming apparatus, a recording sheet discharged from a heat fixing unit is hot and easily curls, and is difficult to handle by an operator. A condensing section where the hydraulic fluid condenses and releases heat to the outside, a sheet cooling roller composed of a heat pipe having a heat insulating section in the middle of these two sections and with no heat flowing in and out, and a recording sheet after passing through the heat fixing section A cooling device adapted to convey while cooling is already known.

However, since such a cooling device is installed in the image forming apparatus, there is a problem that the cooling efficiency decreases as the temperature inside the device increases due to the operation of the cooling device. In order to solve the above problem, there has been proposed a cooling roller in which a radiation fin is attached to one end of the cooling roller. However, even with such a cooling roller, the above-described problem cannot be sufficiently solved.

Therefore, an object of the present invention is to solve the above-mentioned problems of the conventional cooling device, and to provide a cooling device capable of maintaining good cooling efficiency even when the temperature in the image forming device increases due to the operation of the image forming device. To offer.

Means for Solving the Problems In order to achieve the above object, the present invention provides a conventional recording sheet cooling apparatus as described above, wherein a radiation fin is provided at at least one end of the sheet cooling roller. A plurality of fins are provided in a radiating fin housing portion formed in the image forming apparatus by the partition member in a direction substantially perpendicular to the rotation axis of the sheet cooling roller, and supply cooling air to the radiating fins in the radiating fin housing portion. A cooling fan and an air supply hole for taking in outside air are provided, and a flow direction of air entering from the air supply hole is parallel to the radiation fins.

The radiation fins and the cooling fan are located inside the image forming apparatus main body, and the cooling air is taken in from the outside.

Further, the radiation fins and the cooling fan are provided outside the image forming apparatus main body.

In the cooling device of the present invention as described above, when the image is fixed in the heat fixing unit and the heated recording sheet is conveyed, the recording sheet is cooled by the sheet cooling roller, and the sheet that has absorbed heat in this way is used. The cooling roller radiates heat from the radiating fins attached to it, but at this time, the cooling fan blows the cooling air to the radiating fins, so that heat is radiated vigorously and the temperature inside the image forming apparatus rises. Regardless, the effective cooling is continued by the sheet cooling roller.

FIG. 1 shows an image forming apparatus 1 equipped with an embodiment of the present invention.
2 is a cooling device of the embodiment, and 3 is a heat fixing unit.

The heat fixing unit 3 is configured in the same manner as a known fixing unit. A recording sheet 4 having toner on the surface conveyed from an image forming unit (not shown) is heated to approximately 185 ° C. by a heater 6 provided inside. The held fixing roller 7 and the pressure roller 8 having a rubber layer on the surface are pressed and heated to fix the toner on the surface. Such a recording sheet 4 is separated by a separation claw 9, discharged by a discharge roller pair 11, and carried into the cooling device 2 via a guide plate 10. At this time, the temperature of the recording sheet 4 is about 120 ° C.

The cooling device 2 includes a pair of transport rollers 12 and a cooling roller.
13, the transport roller 12 is formed of an elastic body, and the cooling roller 13 is formed of the above-described heat pipe, and a radiation fin 14 is provided at one end thereof (second and third fins).
Figure). These rollers 12, 13 are attached to the front and rear frames 16,
17 rotatably supported by a driving member (not shown).

FIG. 2 shows an embodiment of the cooling device 2. In FIG. 2, reference numerals 21 and 22 denote a front cover and a rear cover of the image forming apparatus 1, respectively. The cooling fan 18 is located in the gap 23 between the rear cover 22 and the cooling fan 18 opposed thereto, and an air supply hole 26 is provided in the rear cover 22 close to the cooling fan 18. I have.

The embodiment of the cooling device 2 shown in FIG. 3 is different from the embodiment described above in that the cooling roller 13 also penetrates through the rear cover 22 and protrudes to the outside. The radiating fins 14 and the cooling fan 18 are surrounded by an auxiliary cover 24 attached to the rear cover 22,
The auxiliary cover 24 is provided with an air supply hole 26 and an exhaust hole 27.

The recording sheet 4 carried into such a cooling device 2 is
The sheet is sandwiched between the rollers 12 and 13, cooled by the cooling roller 13, and then discharged to the discharge tray 28.

When the above-described operation is continued, the temperature in the image forming apparatus 1 gradually increases, and reaches 80 ° C. or more in the vicinity of the heat fixing unit 3. As a result, the recording sheet 4 is carried into the cooling device 2. Although the temperature at the time is as high as about 120 ° C. as described above, since the cooling roller 13 is cooled by the outside air at room temperature of about 30 ° C. or less supplied by the cooling fan 18 through the radiation fins 14. Thus, the recording sheet 4 can be cooled to approximately 70 ° C. or less.

The recording sheet 4 thus cooled is less likely to curl and is easy to handle by an operator.

The embodiment shown in FIG. 4 differs from the embodiment shown in FIG. 1 in that the conveying roller 12 and the cooling roller 13 are turned upside down so that the cooling roller 3 cools the image surface.

In the embodiment shown in FIGS. 5 and 6, a transport belt 19 suspended by belt rollers 29 and 30 is disposed instead of the transport roller 12, and in the embodiment shown in FIG. In the embodiment shown in FIG.

Since the operation of the embodiment shown in FIGS. 4 to 6 is not different from that of the embodiment shown in FIG. 1, its explanation is omitted.

The number of the radiation fins 14 may be increased as needed.

The effect of the invention is as described above, and a plurality of heat radiation fins are provided in the heat radiation fin housing portion formed in the image forming apparatus by the partition member in a direction substantially perpendicular to the rotation axis of the sheet cooling roller. The fin housing section is provided with a cooling fan that supplies cooling air to the radiating fins and an air supply hole that takes in outside air, and the flow direction of air entering from the air supply hole is parallel to the heat radiating fin, The cooling fan supplies cooling air to the radiating fins provided at one end of the sheet cooling roller to cool the cooling roller, so that even if the temperature inside the image forming apparatus rises, the recording sheet can be reliably reduced without lowering the cooling efficiency. To prevent the recording sheet from becoming hot and trying to form a curl, and supplied to the radiation fins by a cooling fan provided in the radiation fin housing. Since the cooling air forms a flow parallel to the radiating fins even during rotation of the sheet cooling roller, heat exchange efficiency is good and cooling is quick, and the exhaust air is discharged from the radiating fin housing. Since the recording sheet is discharged to the outside, it does not pass through the recording sheet transport section, preventing fluttering and jamming of the recording sheet being transported, and separating the radiation fins from other device parts and the partition member. Since it is provided in the radiating fin housing portion that is provided, there is an effect that it is not affected by heat generated from other device parts.

[Brief description of the drawings]

FIG. 1 is a front view of a part of an image forming apparatus equipped with the cooling device of the present invention, FIG. 2 is an explanatory view of a main part of an embodiment of the cooling device of the above, and FIG. Similar explanatory diagram, fourth
FIG. 5 is a front view of a portion surrounded by line A in FIG. 1 of another embodiment of the present invention, FIG. 5 is a view similar to FIG. 4 of still another embodiment, and FIG. It is a similar drawing of an Example. DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 2 ... Cooling device 3 ... Heat fixing part, 4 ... Recording sheet 12 ... Conveying roller, 13 ... Cooling roller 14 ... Radiation fin, 17 ... Rear frame 18 ... Cooling fan, 19 ... Conveying belt 22 ... Rear cover, 23 ... air gap 24 ... auxiliary cover

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Jun Okamoto 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (72) Inventor Kenichi Hasegawa 1-3-6 Nakamagome, Ota-ku, Tokyo Ricoh Co., Ltd. (56) References JP-A-60-1007047 (JP, A) JP-A-4-104265 (JP, A) JP-A-4-104264 (JP, A) JP-A-1-257977 ( JP, A) Actually open 1987-104252 (JP, U) Actually open 1985-70847 (JP, U) Actually open 1985-60-18647 (JP, U) Actually open 1988-200542 (JP, U) Actually open 62-146150 (JP, U)

Claims (3)

(57) [Scope of request for utility model registration] An apparatus for cooling a recording sheet having a sheet cooling roller comprising a heat pipe for conveying a recording sheet discharged from a heat fixing section of an image forming apparatus while cooling the recording sheet is provided with heat radiating to at least one end of the sheet cooling roller. A plurality of fins are provided, and a plurality of radiating fins are provided in a radiating fin housing portion formed in the image forming apparatus by a partition member in a direction substantially perpendicular to the rotation axis of the sheet cooling roller,
The cooling fin housing has a cooling fan that supplies cooling air to the cooling fin, and an air supply hole that takes in outside air.The flow direction of the air that has entered through the air supply hole is parallel to the cooling fin. A cooling device for a recording sheet. 2. A recording paper transport section of a sheet cooling roller is formed between front and rear side frames of an image forming apparatus, and a radiation fin housing section faces one of the front and rear covers of the image forming apparatus and one of the front and rear covers. The cooling device according to claim 1, wherein the cooling device is formed between any of the front and rear side frames. 3. The radiating fin housing portion is formed by one of the front and rear covers of the image forming apparatus and an auxiliary cover attached thereto, and the auxiliary cover exhausts the air in the radiating fin housing portion to the outside. The cooling device according to claim 1, wherein a hole is provided.