JP2001013855A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the temperature rising of a fixing device to a specified temperature from being hindered, to shorten the warm-up time, and to eliminate the waste of power consumption in an image forming device having a cooling duct obtained by blocking between an image recording part and a fixing device. SOLUTION: An image recording part S recording an image on a sheet, and a fixing device 18 inserting the sheet obtained after recording at the image recording part and fixing the recorded image are provided inside an image forming device main body. The cooling duct 34 obtained by interrupting the gap between the part S and the device 18 is arranged between the part S and the device 18, a temperature sensor 42 is provided inside the duct 34, and when the sensor detects that the temperature inside the duct 34 reaches the specified temperature, an axial fan is operated, so that air is introduced to the duct 34.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic copying machine, a printer, a facsimile, or a multifunction machine for recording an image on a sheet in an image recording section and placing the recorded sheet in a fixing device. And an image forming apparatus for fixing a recorded image by heat.

[0002]

2. Description of the Related Art In recent years, for example, in image forming apparatuses such as copiers, the size of the apparatus has been reduced, the gaps between respective units in the main body of the image forming apparatus have become narrower, and the fixing heat of the fixing apparatus adversely affects other apparatuses. There was a problem. For example, in a developing device, toner may be scattered due to a rise in temperature of a developer, and in a cleaning device, the toner may be solidified due to a rise in temperature and a toner recovery mechanism may be locked.

For this reason, some conventional image forming apparatuses include:
As shown in FIG. 7, a cooling duct 3 is disposed so as to block between the image recording unit 1 and the fixing device 2 to prevent radiation and heat conduction from the fixing device 2 and to operate an axial fan (not shown). Some air vents through the cooling duct 3. In the drawing, reference numeral 4 denotes a drum-shaped image carrier, 5 denotes a charging device, 6 denotes a cleaning device, and 7 denotes a transfer / transport device.

[0004]

However, in such an image forming apparatus, when the fixing device 2 is ventilated to the cooling duct 3 in a state where the temperature of the fixing device 2 has not yet risen, for example, when the power of the apparatus main body is turned on, the fixing device 2 There has been a problem that the temperature rise is hindered, the warm-up time is lengthened, and the power consumption is increased.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image forming apparatus having a cooling duct which blocks a space between an image recording section and a fixing device so as not to prevent the temperature of the fixing device from rising to a predetermined temperature and to warm up the device. And reducing unnecessary power consumption.

[0006]

Accordingly, the present invention provides
In an image forming apparatus such as a copying machine, a printer, a facsimile, or a multi-function machine thereof, an image is recorded on a sheet by an image recording unit, and the recorded sheet is placed in a fixing device to fix a recorded image. A cooling duct is arranged to block between the fixing devices, and a temperature sensor is provided in the cooling duct,
When the temperature sensor detects that the temperature in the cooling duct has reached a predetermined temperature, an axial fan is operated to ventilate the cooling duct.

The cooling duct has a resin member on the fixing device side,
It is preferable that the image recording unit side is made of a sheet metal member, and a stay connecting the opposite side plate frames in the image forming apparatus main body is also used.
It is more preferable to provide a heat insulating material outside the resin member. The fixing device side of the cooling duct itself may be made of a heat insulating member.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic configuration of an internal mechanism of a copying machine according to the present invention. Reference numeral 10 in the figure
Is a mechanical device body.

A drum-shaped image carrier 11 is provided in an apparatus main body 10 and a charging device 12 and a developing device 1 are provided therearound.
3. The transfer / transport device 14, the cleaning device 15, and the like are arranged. A writing device 17 is provided above them, and an image recording unit S is formed as a whole.

On the left side of the image recording unit S in the figure, a fixing device 1 is provided.
8 is provided. The fixing device 18 includes a fixing roller 19 having a built-in heater and a pressure roller 20 pressed against the fixing roller 19.

A known reading optical system 21 is provided on the image recording section S and the fixing device 18. On the other hand, below the image recording section S and the fixing device 18,
A double-sided device 22 and a paper feed cassette 23 are provided in two upper and lower stages.
From the two-sided device 22 and the paper supply cassette 23, a paper supply path 24 is extended toward the lower side of the image carrier 11, and is branched from the middle of a paper discharge path 25 extending from an exit of the fixing device 18 and is inverted toward the two-sided device 22. The path 26 is formed.

A contact glass 27 is provided on the upper surface of the apparatus main body 10. The contact glass 27
The automatic document feeder 28 is mounted on the apparatus body 10 so as to be openable and closable.

A manual tray 29 for guiding a manual sheet to the paper feed path 24 is provided on the right side of the apparatus main body 10 so as to be freely opened and closed. Although not shown, a discharge tray for receiving sheets discharged through the discharge path 25 is detachably attached to the left side surface of the apparatus main body 10.

When making a copy using this copying machine, a document is set on the automatic document feeder 28 or the document is directly opened on the contact glass 27 by opening the automatic document feeder 28 as is well known. set. And
Press the start switch (not shown) and the automatic document feeder 2
The reading optical system 21 reads the original conveyed onto the contact glass 27 by driving the scanner 8 or the original set on the contact glass 27 in advance.

At the same time, the sheet supply roller 30 is rotated, the sheet in the sheet supply cassette 23 is sent out to the sheet supply path 24 and conveyed by a plurality of conveyance rollers 31, and the registration roller 32 rotates the image carrier 11 in timing. And is fed below the image carrier 11. Or, rotate the paper feed roller 33,
The manual feed sheet set on the opened manual feed tray 29 is put into the paper feed path 24, and is also sent to the lower side of the image carrier 11 by the registration roller 32 in synchronization with the rotation of the image carrier 11.

On the other hand, the image carrier 11 is rotated clockwise in the drawing, first the surface is uniformly charged by the charging device 12, and then a laser beam is irradiated in accordance with the read content read by the above-mentioned reading optical system 21. And writing is performed by the writing device 17,
An electrostatic latent image is formed on the surface of the image carrier 11, and then toner is adhered by the developing device 13 to visualize the electrostatic latent image.

Then, the visible image is transferred by the transfer / conveyance device 14 to the sheet sent below the image carrier 11 as described above. The residual toner on the image carrier 11 after the image transfer is removed by the cleaning device 15 and cleaned to prepare for the next similar image recording.

On the other hand, the sheet after the image transfer is conveyed by the transfer / conveyance device 14 and put between the fixing roller 19 and the pressure roller 20 of the fixing device 18, and heat and pressure are applied between them to transfer the image To establish. Thereafter, the paper is discharged onto a paper discharge tray (not shown) through the paper discharge path 25.

When recording is also performed on the back side of a sheet using this copying machine, after recording on one side, the recording sheet is put into the double-sided device 22 through the reversing path 26, where it is reversed and again moved below the image carrier 11. The image is sent, the image separately formed on the image carrier 11 is similarly transferred to the back surface, and then discharged onto the paper discharge tray.

FIGS. 2 and 3 schematically show an enlarged view of a main part of the above-described copying machine. As you can see from the figure,
Although not shown in FIG. 1 in this copying machine, the fixing device 1
8 around the device body 10 (the fixing roller 1).
9 and the cooling duct 34 extending in the axial direction of the pressure roller 20).
Is provided. The cooling duct 34 also serves as a stay for connecting opposed side plate frames (not shown) provided to face each other in the apparatus main body 10, and a horizontal portion 34 </ b> A is arranged on the fixing device 18. Cleaning device 1
The inclined portion 34B is arranged between the five.

FIG. 4 shows the cooling duct 34 viewed from another angle. As shown in FIG. 4, the cooling duct 34
Is a plate-like resin member 3 having a lower thermal conductivity than the fixing device side.
In step 5, the image recording section S is made of an aluminum sheet metal member 36 having a relatively high thermal conductivity made by extrusion integral molding, and an air inlet 37 is provided on the front side to form a hollow inside.

As can be seen from FIG.
On the rear upper surface of A, an upwardly protruding portion 34C that gradually increases rearward is formed, and an exhaust port 38 that opens rearward from inside the cooling duct 34 is provided therein.
, The axial fan 39 is attached in an inclined manner so that the axial direction matches the direction A of the flow of the air passing therethrough.

In the inclined portion 34B, air taken in from an air inlet 37 as shown by an arrow in FIG.
The guide wall 40 is formed to be guided to the outside. FIG.
As shown in FIG. 7, when the temperature sensor 42 detects that the temperature in the cooling duct 34 has reached a predetermined temperature, the axial fan 39 is operated to activate the cooling duct 3.
4 is ventilated.

As a result, the heat of the sheet metal member 36 is removed, and the temperature of the image recording section S is prevented from rising. At the same time, the heat of the resin member 35 is hardly transmitted to the sheet metal member 36. Then, heat insulation between the fixing device 18 and the image recording unit S is performed to prevent the temperature of the image recording unit S from rising.

By the way, in the example described above, the cooling duct 3
4 was made of a resin member 35,
As shown in FIG. 7, a heat insulating material 44 such as a foam material may be attached to the outside of the resin member 35.

Further, as shown in FIG. 6, the cooling duct itself may be formed with a heat insulating member 45 on the fixing device 18 side. 5 and FIG. 6, the reference numerals used in the corresponding portions of the examples shown in FIG. 1 to FIG. 4 are used as they are.

[0027]

As described above, according to the present invention, the cooling duct is arranged so as to block between the image recording unit and the fixing device, and the temperature in the cooling duct is set to a predetermined temperature by the temperature sensor provided in the cooling duct. When it is detected that the fixing device has reached the temperature, the axial fan is operated to ventilate the cooling duct for the first time. The ventilation of the fixing device is stopped so that the temperature of the fixing device does not rise to a predetermined temperature, the warm-up time can be shortened, and unnecessary power consumption can be eliminated.

According to the second aspect of the present invention, the cooling duct is made of a resin member on the fixing device side and a sheet metal member on the image recording section side.
The image recording unit side can be effectively cooled. In addition, since the stay that connects the opposing side plate frames in the image forming apparatus body is also used, the mechanical strength of the image forming apparatus can be increased.

According to the third aspect of the present invention, since the heat insulating material is provided outside the resin member, the heat insulating effect is enhanced to further prevent the heat radiation from the fixing device side, while ensuring the temperature rise on the image recording section side. Can be prevented.

According to the fourth aspect of the present invention, the fixing device side of the cooling duct itself is made of a heat insulating member. Therefore, the structure is simplified, the weight is reduced, and the price is reduced. While the heat radiation from the apparatus side is further prevented, the temperature rise on the image recording section side can be surely prevented.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an internal mechanism of a copying machine according to the present invention as viewed from the front side.

FIG. 2 is a schematic perspective view showing an enlarged main part of the copying machine.

FIG. 3 is an enlarged schematic configuration diagram showing a main part thereof as viewed from the front side.

FIG. 4 is a perspective view of a cooling duct used therein.

FIG. 5 is an enlarged schematic configuration diagram showing a main part of another copying machine according to the present invention, which uses different cooling ducts, as viewed from the front side.

FIG. 6 is an enlarged schematic configuration diagram showing a main part of still another copying machine using a different cooling duct when viewed from the front side.

FIG. 7 is an enlarged schematic perspective view showing a main part of a conventional copying machine viewed from the front side.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Machine apparatus main body (image forming apparatus main body) 11 Image carrier 12 Charging device 13 Developing device 14 Transfer / transport device 15 Cleaning device 17 Writing device 18 Fixing device 34 Cooling duct 34A Horizontal portion 34B Inclined portion 34C Projection 35 Resin member 36 Sheet metal member 37 Air intake 38 Exhaust port 39 Axial fan 42 Temperature sensor 44 Insulation material 45 Insulation member S Image recording unit

Claims (4)

[Claims] 1. An image forming apparatus for recording an image on a sheet by an image recording unit, inserting the recorded sheet into a fixing device, and fixing the recorded image, wherein the image recording unit and the fixing device are intercepted and cooled. A duct is arranged, a temperature sensor is provided in the cooling duct, and when the temperature sensor detects that the temperature in the cooling duct has reached a predetermined temperature, an axial fan is operated to ventilate the cooling duct. Image forming apparatus. 2. The cooling duct, wherein the fixing device side is made of a resin member, and the image recording unit side is made of a sheet metal member, and the cooling duct also serves as a stay connecting between opposed side plate frames in the image forming apparatus main body. Item 2. The image forming apparatus according to Item 1. 3. The image forming apparatus according to claim 2, wherein a heat insulating material is provided outside the resin member. 4. The image forming apparatus according to claim 1, wherein the fixing device side of the cooling duct itself is made of a heat insulating member.