JPH01243076A - Image forming device - Google Patents

Abstract

PURPOSE:To prevent the occurrence of fusion, coagulation, etc., of toner in a cleaning machine and a developing device by providing a ventilation opening on the bottom of an outer cover, ventilation openings on the side plates of the outer cover, and fans on said ventilating openings. CONSTITUTION:A sheet material feeding device 2 is disposed slantly above and behind an image forming and processing device 2; a fixing device 14 fixing an unfixed image formed on sheet material, and a fixed sheet material ejecting device 40 are disposed slantly below and in front of the device 2; and an ejected paper tray is disposed on the front side of the device 2. In this case, the ventilation opening 22 is provided on the bottom 1a of the outer cover right under and in the vicinity of the process cartridge 2, the ventilation openings 26 and 27 are provided on the side plates 1b of the outer cover, in the vicinity of the position corresponding to the edge of the fixing device in the longitudinal direction of the fixing device, and one or more fans 23 are provided on a part or all of the ventilation openings. Thereby, the occurrence of fusion, coagulation, etc., of toner in a cleaning machine and a developing device can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] "Industrial Application Field" The present invention relates to an image forming apparatus such as an electronic copying machine or a laser beam printer, and particularly to a small-sized image forming apparatus.

``Prior Art'' Conventionally, laser beam printers and the like used as output devices in information processing systems are based on electronic copying machines, but in recent years, paper that is ejected face-down with the screen facing downward has been used as a page printer. From the viewpoint of ease of maintenance such as transport bus jam removal and storage efficiency of electrical components, the paper feed device is placed diagonally above the rear direction of the image forming process, and the fixing device and paper ejecting device are placed diagonally below the front side. A printer has been proposed, and it has attracted attention as a very effective form of printer because it occupies less floor space and has the advantage of being able to perform all operations from the front.

"Problem to be Solved by the Invention" However, in the above conventional example, since the fixing device is disposed diagonally below the image forming process device, the heat generated in the heating fixing device is transferred to the developing device of the image forming process device, This causes the temperature to rise inside the toner container and cleaning device, causing toner to fuse and solidify. Further, ozone generated in a charger of an image forming process apparatus causes oxides and the like to adhere to the surface of the photosensitive drum, and moisture combined with the oxides causes image deletion.

Furthermore, since ozone is heavier than air, if ozone accumulates, it will accelerate the deterioration of the rubber rollers (conveyance roller, fixing roller, etc.) located below. Furthermore, the lifespan of the conveyor belt and the like is also shortened due to the rise in temperature of the conveyor belt unit, which is a pre-process of the fixing device.

"Means for Solving the Problems" The present invention provides a sheet material feeding device disposed diagonally upward in the rear direction of an image forming processing device, and an unfixed image is formed by the image processing device diagonally downward in the front side. In an image forming apparatus that is provided with a fixing device for fixing a sheet material and a discharge device for the fixed sheet material, and a paper discharge tray is disposed on the front side of the image forming process device, directly below the image forming process device. A ventilation opening is provided in the bottom plate of the exterior cover of the image forming apparatus nearby, and a ventilation opening is provided in the side plate of the exterior cover near the position corresponding to the longitudinal end of the fixing device, and a fan is installed in some or all of the ventilation openings. This is an image forming apparatus characterized by being provided with.

Embodiment 1 FIG. 1 is a longitudinal sectional view of a laser beam printer as an image forming apparatus showing a first embodiment of the present invention. The overall arrangement is such that a sheet material feeding device 21 is disposed diagonally above the rear of the process cartridge 2, a fixing device 14 is disposed diagonally downward toward the front, and a paper ejecting device 40 is disposed at the same location following the fixing device 14. has been done. Here, the fixing device 14 has a fixing roller 14a equipped with a heater at its axial center, and a pressure roller 141 whose metal core is coated with rubber and pressurizes the fixing roller 14a.

The entire apparatus 1 includes a process cartridge 2 which is removably attached as an image forming process device. Inside the process cartridge 2 is a photosensitive drum 3 as an image carrier.
, and process equipment that controls a part of the known electrophotographic process, such as a charging device 4, a developing device 5, and a cleaning device 6, which are arranged around the device, are built-in. The image forming apparatus optical drum 3 rotates in the direction of the arrow shown in the figure, and the laser beam emitted from the scanner unit 7 that emits and scans the photosensitive drum 3 uniformly charged by the charger 4 is transmitted through the mirror 8. By irradiating the photosensitive drum 3, a latent image corresponding to desired image information is formed on the photosensitive drum 3, and the latent image is developed by the developing device 5.

A paper feed cassette 9 that partially stores sheet materials S along the conveyance path of the sheet materials is disposed at the upper part of the apparatus main body 1 and faces toward the front (front) side of the main body 1, that is, toward the right side in the figure. Then, the sheet materials S are sent out one by one from the top by the feeding roller 10.

The sheet material S sent out from the paper feed cassette 9 passes through a downwardly curved feeding guide member 17, its posture is controlled by registration rollers 11, and the sheet material S is synchronized with the movement of the photosensitive drum 3. After the developed image on the photosensitive drum 3 is transferred between the photosensitive drum 3 and the developing device 5, the sheet material S is guided to the fixing device 14 by the conveyor belt unit 13. The image is fixed onto the top. The conveyance path of the sheet material S from the registration rollers 11 to the fixing device 14 is configured to be slightly inclined in the front-rear direction and directed downward on the road.

The sheet material S that has passed through the fixing device 14 is guided by a rubber conveyance roller 18 to a discharge guide member 19 that curves in the opposite direction to the feed guide member 17, and is then guided by a flapper 20 to a face-up discharge roller 15a. from the same discharge tray 16a or from the face-down discharge roller 1.
51) onto the same discharge tray 161).

In the illustrated example, the sheet material S discharge direction of the face-up discharge tray 16a and the same discharge roller 15a is configured to be opposite to and substantially parallel to the direction in which the sheet material S passes through the fixing device 14, and The sheet material ejection direction of the face-down ejection tray 16b and the same ejection roller 15b is configured so that the sheet material S stops slightly in the direction substantially perpendicular to the direction in which the sheet material S passes through the fixing device 14.

In the illustrated example, the output trays 16a and 16b have one common tray installed at the mounting position of the face-up output tray 16a shown in solid lines in FIG. The flapper 20 is configured to be selectively arranged, and the flapper 20 is selectively arranged depending on the arrangement position.
is automatically switched.

That is, when the ejection tray 16& is located on the face-up side, the flapper 20 is in the position shown by the solid line, and the sheet material S passing through the fixing device 14 passes through the guide member 19 and the face-up ejection roller 15a, and is approximately The orientation is changed by 180° and the paper is discharged onto the discharge tray 16a with the image side (printed side) facing upward. In addition, when the discharge tray 16b is located on the face-down side, the flapper 20 is at the chain line position in the figure, and the conveying direction is changed by about 90 degrees by the guide member 19 and the face-down discharge roller 15b, and the conveyance direction is changed by about 90 degrees to perform face-down discharge. The pages are stacked in order on the tray 16b with the image side facing downward.

Note that the above-mentioned face-up discharge tray 16a and face-down discharge tray 161) may be provided separately, and the flapper 20 may be configured to be switched arbitrarily by the operator.

After the image is transferred to the sheet material S by the transfer charger 12 as described above, the photosensitive drum 3 is cleaned of residual toner by the IJ-ning device 6.

A cartridge 2 is mounted on the bottom plate 1a of the exterior cover of the device main body 1.
A bottom louver 22 is provided as a ventilation opening almost directly below. A fan 26 is provided at a position corresponding to the louver 22 to exhaust air in the direction indicated by the arrow. Bottom plate 1 of device main body 1
Feet 24 protrude from the bottom plate 1a of the apparatus main body 1 to ensure a space between the main body 1a and the desk top on which the main body 1 is placed, and to vent the air. An ozone filter 25 that captures ozone generated within the device main body 1 and prevents ozone from flowing out of the device main body 1.
is provided overlapping the louver 22.

FIG. 2 is a perspective view of FIG. 1, showing the positional relationship between the main parts inside the device main body 1 and the louvers 26 and 27 provided as ventilation holes in the side plate 1b of the exterior cover of the device main body 1. The louvers 26 and 27 are provided in the openings of the side plates 1b of the exterior cover of the apparatus main body 1 in the vicinity of positions corresponding to both ends of both sides of the fixing device 14, and are indicated by arrows 0. Louver 26 in direction B
Outside air is introduced from ゜27, and the warmed air around the fixing device 14 is guided in the direction of arrow JD, and the fan 23
The gas is exhausted in the direction of arrow A through the ozone filter 25 and the louver 22. At this time, ozone generated by the chargers 4 and 12 arranged around the photosensitive drum 3 is also guided and captured by the ozone filter 25 on the exhaust side of the fan 23.

Louvers 26 and 27 do not necessarily have to be on both sides,
Furthermore, if fans are installed at the positions of the louvers 26 and 27 to forcefully draw in air, the effect will be further improved. In either case, since the air flow within the apparatus main body 1 is made into a Y-shape or a horizontal flow downward, residual heat from the fixing device 14 can be efficiently exhausted.

"Embodiment 2" FIG. 3 is a modification of the first embodiment. Bottom louver 22
A guide 28 facing diagonally downward and rearward is provided on the bottom plate 1a so that the exhausted hot air flows along the lower part of the bottom plate 1a in the direction of arrow F diagonally downward and can be exhausted in the opposite direction from the front operation side. It is. Therefore, the operator standing on the front operation side can be prevented from being directly exposed to hot air.

"Example 3" FIG. 4 shows another modification of the first embodiment.

An auxiliary outside air intake fan 29 and a louver 31 are superimposed on the rear end plate 1C of the exterior cover of the apparatus main body 1 to create an air flow in the direction of arrow G from the rear of the scanning optical system toward the front operation direction. . As a result, it is possible to prevent the reflectance from decreasing due to dirt on the mirror 8 or other dirt on the scanning optical system.

In addition, since the electrical components 30 of the power supply device and the control device are housed in the room space after the scanning optical system, the electrical components 30
It can also serve as a cooling device. Furthermore, if a vent 32 is provided in the housing of the charger 4 and a vent 33 is provided in the cartridge 2 at the same position as the vent 32, the wire of the charger 4 can be connected from the side opposite to the photosensitive drum 3. Since outside air is blown in, the wires of the charger 4 can be prevented from getting dirty, and the image can be stabilized. Furthermore, process cartridge 2
Needless to say, if a vent hole 39 is provided at the bottom of the tank, the ozone capture effect will be further improved.

Embodiment 4 FIG. 5 shows another embodiment in which an intake fan 34 for sucking outside air is provided at a position corresponding to the louver 22 substantially directly below the cartridge 2 at the bottom of the main body 1 of the apparatus. In this embodiment, direct blowing of cold air in the direction of arrow H from outside air in the direction of arrow H has the effect of cooling the parts of the process cartridge 2 (particularly the cleaning device 6) which are close to the fixing device 14 and are easily affected by heat. This is based on the internal configuration of this embodiment, that is, the car 1-
This effect is unique to the vertical configuration of IJ Tsuji 2. However, the outside air taken in the direction of the arrow
In order to carry the heat upward together, in this embodiment, as shown in FIG. It is necessary to install and exhaust heat. At that time, if an ozone filter is inserted between the louver 26 and the fan 35 and between the louver 27 and the fan 36, the effect of capturing ozone can be obtained, as in the first embodiment.

Further, by making the total air volume of the exhaust air larger than the total air volume of the intake air, rising of hot air around the fixing device 14 can be prevented, and the cooling effect is further improved. If only one exhaust louver is provided, install the louver 27 on the right side facing the front operation side.
(fan) is provided, and the intake louver 22 (fan 34) may be disposed to the left of the center portion substantially directly below the process cartridge 2 toward the front operation side.

The reason why the exhaust louver is best placed on the right side will be explained with reference to FIG. 7. In practice, the image forming apparatus according to the embodiment of the present invention is likely to be placed on the right side of the personal computer 46 on a desk. Therefore, if an exhaust port is provided on the left side of the image forming apparatus, hot air will be directly applied to the operator, so it is better to provide a louver on the right side. Further, when there is only one exhaust louver, the effect is greater if the intake louver is located closer to the left side than the center because air can flow throughout the fixing device 14.

"Embodiment 5" FIG. 8 is a modification of Embodiment 4 (FIG. 5), and is different from FIG. 5 in the louver 37A8. The blades of the louvers 37 and 38 face diagonally rearward and outward, and the exhaust direction is directed to the side opposite to the front operation side. This protects the operator. With this method, only one exhaust louver is required on the left side.

"Embodiment 6" FIG. 9 is a modification of the embodiment 1. Although the cooling effect is improved by taking in outside air from the bottom louver 22, if the fixing device 14 is directly cooled too much, an excessive capacity heater may be required for the fixing roller 14a to maintain a predetermined temperature, which may cause adverse effects. will also appear. Therefore, if the area around the fixing device 14 is surrounded by heat insulating materials 41 and 42 and outside air is allowed to flow outside the heat insulating materials 41 and 42, the effect will be further improved.

Thermal insulators 41 and 42 surround the outside of the fixing device 14 to ensure a sheet material conveyance path, and one end of the insulator 41 is connected to the tray 16.
It extends to a. The louver 26 of the outside air intake port is located on the opposite side of the heat insulating material 41, 42 from the fixing device 14 side.

In such a configuration, the outside air taken in through the louver 26 does not directly cool the fixing device 14, which is a heat source, but flows outside the heat insulating materials 41 and 42 and is exhausted by the exhaust fan 23. Further, the heat of the fuser 14 is not directly transmitted to the process cartridge 2 due to the heat insulating materials 41 and 42, and the process cartridge 2 is not heated and the heat of the fuser 14 is not directly transmitted to the process cartridge 2.
4. The effect of keeping warm increases. Similar to other embodiments, the effect can be further improved by providing an intake fan in the louver 26.

What can be said about all of the embodiments 1 to 6 above is that whether the shape is 7-shaped or the bent shape, air flow is created in the space between the fixing device and the process cartridge, and the heat released from the fixing device is efficiently discharged. This is what is being communicated to the cartridge side.

Further, in the above embodiments, the image forming process has been explained using a removable process cartridge, but it goes without saying that the present invention is not limited to a removable process cartridge.

〔Effect of the invention〕

As described above, the present invention provides a ventilation hole in the bottom plate of the exterior cover of the image forming apparatus immediately below the image forming process apparatus, and a side plate of the exterior cover in the vicinity of a position corresponding to the longitudinal end of the fixing device. The image forming apparatus is characterized in that a ventilation port is provided in the ventilation port, and a fan is provided in some or all of the ventilation ports, thereby providing the following effects.

The heat emitted from the fixing device can be efficiently discharged, and the temperature rise of the image forming process device can be suppressed. As a result, it is possible to prevent the toner from fusing or coagulating in the IJ-coating device or developing device of the image forming process apparatus. Furthermore, if an ozone filter is provided at the exhaust port, it is possible to efficiently capture ozone generated around the charger of the image forming process apparatus, and it is also possible to prevent image deletion and the like from occurring.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a first embodiment of the invention, FIG. 2 is a perspective view of the first embodiment of the invention, and FIG. 6 is a longitudinal sectional view of the second embodiment of the invention. FIG. 4 is a vertical cross-sectional view of a third embodiment of the present invention, FIG. 5 is a vertical cross-sectional view of a fourth embodiment of the present invention, and FIG. 6 is a perspective view of a fourth embodiment of the present invention. FIG. 7 is a perspective view showing a usage state in which the device main body of the present invention is arranged, FIG. 8 is a perspective view of a fifth embodiment of the present invention, and FIG. 9 is a longitudinal cross-section of a sixth embodiment of the present invention. It is a front view. 1. Equipment body 2. Process cartridge 14.
・Fuser 22・・Bottom louver 23・・Fan 25・
・Ozone filter 26° 27 one side louver 41
,42...Insulation material. Patent applicant Canon Co., Ltd.

Claims (1)

[Claims] 1. A sheet material feeding device is disposed diagonally above the rear direction of the image forming process device, and a fixing device and a fixing device are provided diagonally below the front side for fixing the sheet material on which an unfixed image has been formed by the image processing device. In the image forming apparatus, the bottom plate of the exterior cover of the image forming apparatus is installed in the vicinity directly below the image forming process apparatus. An image forming apparatus characterized in that a ventilation hole is provided in the side plate of the exterior cover near a position corresponding to a longitudinal end of the fixing device, and a fan is provided in some or all of the ventilation holes. Device.