JPH0950225A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device capable of preventing an abnormal image from being formed because the inside of the body of the device is filled with heat and vapor, reducing the cost, reducing noise and saving energy. SOLUTION: This image forming device utilizing exothermic action to form image is provided with a duct 14 for guiding exhaust air containing vapor generated in the device and an aperture part 13 to discharge the exhaust air to the outside of the device is formed continuously to the duct 14 on a device armor 1, then an aperture part 13b to discharge hot air, with which the device is filled, to the outside of the device is formed at a part of the aperture part 13. The air containing the heat and the vapor generated in a fixing device 23 is taken in the duct 14 and discharged to the outside of the device from the aperture part 13 of the armor 1 and the aperture part 13b is formed at the aperture part 13 in addition to an aperture part 13a having aperture area equal to that of the duct 14, so that the air inside the device warmed by the duct 14 is discharged to the outside of the device body from the aperture part 13b, and the abnormal image is prevented from being formed because the inside of the body is filled with the heat and the vapor.

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 that forms an image by utilizing a heat generation effect.

[0002]

2. Description of the Related Art A conventional example of such an image forming apparatus is shown in FIG. That is, FIG. 9 is a schematic sectional view of a conventional image forming apparatus. In FIG. 9, 1 is an exterior of the image forming apparatus main body, 2 is a scanner unit, 3 is a photoconductor, 4 is a transfer roller, and 5 is a paper feed roller. , 6 is a separation pad, 7 is a heat roller, 8 is a pressure roller, 9 is a fan, 10 is an opening provided in the exterior 1, and 11 is paper.

Then, the paper 11 is fed by the paper feeding device composed of the paper feeding roller 5 and the separating pad 6, and the paper 11 is fed by the developing unit composed of the scanner unit 2, the photoconductor 3 and the transfer roller 4. The unfixed image is transferred onto the paper 11, and the paper 11 to which the unfixed image is transferred is conveyed to a fixing device 23 composed of a heat roller 7 and a pressure roller 8. In the fixing device 23, the action of heat is utilized. The image is fixed on the paper 11. At this time, heat generated by the fixing device 23 (indicated by a dashed arrow in FIG. 9) and steam generated by applying heat to the paper 11 (indicated by a chained arrow in FIG. 9)
Is discharged to the outside of the exterior 1 by using a fan 9.

[0004]

However, in the above-mentioned conventional image forming apparatus, noise due to the exhaust fan 9 is likely to cause a problem, and it is necessary to achieve cost reduction and energy saving by reducing the number of parts. An image forming apparatus that does not use a fan has been proposed.

However, an image forming apparatus that does not use a fan has the following problems to be solved. (1) With the conventional structure in which only the opening is formed in the exterior, the temperature inside the apparatus rises due to the heat and water vapor accumulated inside the apparatus body, and the thermal influence on the cartridge and the like is large, and the mirror fog of the scanner is fogged. There is a problem such as an image or a drop of water drops inside the device. (2) Because the fan does not force the exhaust,
The cooling efficiency of the fixing device is lowered, and when the central reference sheet is passed, a problem of temperature rise at both ends of the fixing device occurs.

The present invention has been made in view of the above problems. An object of the present invention is to prevent generation of an abnormal image due to heat and water vapor trapped inside the main body of an image forming apparatus that does not use a fan. An object of the present invention is to provide an image forming apparatus that can prevent the cost, realize low cost, low noise, and energy saving.

[0007]

In order to achieve the above-mentioned object, the invention according to claim 1 is an image forming apparatus which utilizes a heat generating effect for image formation, and a duct for guiding exhaust gas containing water vapor generated in the apparatus. An opening for discharging the exhaust to the outside of the device is formed continuously with the duct on the exterior of the device, and hot air trapped inside the device is discharged to the outside of the device at a part of the opening. The opening is provided.

The invention according to claim 2 is characterized in that, in the invention according to claim 1, an opening is provided in an intermediate portion of the duct, and an outside air inlet for introducing outside air into the duct is provided.

A third aspect of the present invention is characterized in that, in the first aspect of the invention, the exhaust outlet of the duct is provided above the left and right ends of the fixing device in the sheet material conveying direction.

A fourth aspect of the present invention is characterized in that, in the first aspect of the invention, a wall is provided above the exhaust inlet of the duct to form a space between the duct and the exterior.

According to a fifth aspect of the invention, in the fourth aspect of the invention, the wall surface is formed in a substantially V shape so that the rising exhaust gas is guided to the exhaust gas outlet of the duct.

According to a sixth aspect of the present invention, in the first aspect of the invention, the duct is provided in an openable / closable outer cover, and when the outer cover is opened, an opening through which the inner surface of the duct is visible cannot be seen by the user. It is characterized in that it is provided in the direction.

According to a seventh aspect of the present invention, there is provided a cartridge that is attachable to and detachable from the main body of the apparatus, and the cartridge is attached and detached at a position adjacent to the fixing device and the duct with the air passage interposed therebetween. When the convex portion is provided in the air passage direction and the cartridge is not in the correct position, the operation of closing the outer cover sets the cartridge in the correct position by the convex portion or prevents the operation of closing the outer cover to call attention to the user. It is characterized by having done.

[0014]

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

<First Embodiment> FIG. 1 is a schematic sectional view of an image forming apparatus according to a first embodiment of the present invention. In this figure, the same elements as those shown in FIG. 9 are designated by the same reference numerals. Therefore, the description thereof will be omitted below.

In the image forming apparatus according to the present embodiment, a duct 14 for covering the paper ejection frame 16 is provided above the paper ejection frame 16 in the exterior 1 and a position above the duct 14 of the exterior 1 is provided. An opening 13 (13a is a part having the same size as the duct 14 and 13b is a part larger than the duct 14) is formed in the opening.

Thus, it becomes possible to reliably take in the heated air containing the water vapor generated in the fixing device 23 into the duct 14, and the water vapor diffuses into the main body of the apparatus to fog the scanner mirror. Disappears.

However, since the air having heat generated in the fixing device 23 passes through the duct 14, the duct 14 serves as a heat source, which heats the air inside the main body of the apparatus and attaches it inside the main body by the warmed air. The cartridge 30 thus prepared is heated. This is not preferable in the image forming process.

Therefore, in the present embodiment, the opening area of the opening 13 of the exterior 1 is set to the opening area (1
3a) and the cartridge 3
Only the portion 13b enlarged to the side where 0 is attached is enlarged so that the air inside the apparatus main body warmed by the duct 14 is discharged from the portion 13b of the opening 13 to the outside of the main body.

Further, an opening 14d is provided in an intermediate portion of a side surface of the duct 14 near the outside of the apparatus main body, and outside air is introduced into the duct 14 through the opening 14b so as to suppress the temperature rise of the air in the duct 14. There is. Thereby, the radiation of heat from the duct 14 can also be suppressed. In the image forming apparatus according to the present embodiment, the paper discharge port 24 is opened below the main body, and a system capable of naturally discharging hot air above the fixing device 23 is configured. However, in this image forming apparatus, the hot air of the fixing device 23 escapes to the upper side of the device, so that cold air outside the machine is naturally taken into the inside of the main body from the vicinity of the paper discharge port 24.

FIG. 2 shows the positional relationship between the duct 14 and the fixing device 23.

The paper 11 is fed by the paper feeding device composed of the paper feeding roller 5 and the separating pad 6 shown in FIG.
An image is transferred onto the paper 11 by the developing unit composed of the scanner unit 2, the photoconductor 3 and the transfer roller 4,
The paper 11 on which the image is transferred is conveyed to a fixing device 23 composed of a heat roller 7 and a pressure roller 8, and the image is fixed in the constant fixing device 23 by the action of heat. At this time, the heat generated by the fixing device 23 is conducted to the paper 11 passing through the nip portion formed by the heat roller 7 and the pressure roller 8 to fix the image on the paper 11, and then to the outside of the apparatus together with the paper 11. Is discharged.

However, in the portion of the nip portion where the paper 11 does not pass, the heat is not discharged and is accumulated in the rollers 7 and 8, so that the temperature of the left and right end portions of the fixing device 23 easily rises in the paper passing direction.

Therefore, in this embodiment, the duct 14 is used.
The exhaust outlets are provided so as to open at the left and right ends of the upper portion of the fixing device 23, and the air around the both ends of the fixing device 23 can be easily discharged.

Further, in the present embodiment, the duct 14
A space 20 is secured between the outer wall 1 and the exterior 1 by providing the wall surface 14e above the exhaust inlet. Since the air layer in this space 20 constitutes a buffer for the temperature difference between the outside of the device and the inside of the duct 14, the water vapor generated in the fixing device 23 is not rapidly cooled, and the amount of dew condensation 22 in the duct 14 is large. Can be kept small. Then, the air containing water vapor is discharged from the opening 13 of the exterior 1 through the duct 14, so that water droplets do not adhere to the inside of the exterior 1.
As a result, the reliability of the device is enhanced, and the adverse effects of dew condensation on the output medium, electrical components, etc. can be eliminated.

By the way, in the present embodiment, the duct 14 is attached to the outer cover 1A which can be opened and closed. As shown in FIG. 3, when the outer cover 1A is opened, the opening 14b of the duct 14 is open to the user. Has a structure that faces invisible direction. Since the dew condensation 22 generated on the inner wall of the duct 14 is blocked by the wall surface 14a of the duct 14, the dew condensation 22 deviates from the line of sight 21 of the user's operation and cannot be seen by the user. Therefore, the user does not have to worry about the dew condensation 22 that occurs on the inner wall of the duct 14 that does not affect the image formation, and high reliability can be ensured for the apparatus.

Further, in this embodiment, the openable / closable outer cover 1A is opened to attach / detach the cartridge 30 to / from the apparatus main body, but an air passage is provided between the fixing device 23, the duct 14 and the cartridge 30. ing. When the convex portion 14c such as a rib is provided from the outer side surface of the duct 14 in the direction of the air passage and the cartridge 30 is not in the correct position, the exterior cover 1
By the operation of closing A, the cartridge 30 is
Press to set it to the proper position. Alternatively, when the cartridge 30 is not in the correct position, the outer cover 1A
Prevents the closing action of the and alert the user. This allows
It is possible to dispose the cartridge 30 at a position adjacent to the fixing device 23 and the duct 14 which are likely to be heated, and the convex portion 14c provided on the outer surface of the duct 14 is provided on the cartridge 3 side.
By using it for detecting the wrong insertion of 0 or correcting the wrong insertion, it becomes possible to make the apparatus main body compact, reduce the number of parts accordingly, and reduce the cost.

As described above, according to the present embodiment, it is possible to prevent the occurrence of an abnormal image due to the accumulation of heat and water vapor inside the main body in an image forming apparatus that does not use a fan, and Since it is unnecessary, cost reduction, low noise, and energy saving can be realized.

<Second Embodiment> Next, a second embodiment of the present invention will be described with reference to FIGS. 4 is a perspective view of the image forming apparatus, FIG. 5 is a perspective view showing the internal structure of the image forming apparatus, FIG. 6 is a schematic view showing the positional relationship between the duct and the fixing device in the image forming apparatus, and FIG. It is a perspective view of the duct. In these drawings, the same elements as those shown in FIGS. 1 to 3 are denoted by the same reference numerals, and description thereof will be omitted below.

In the present embodiment, the wall surface 14e above the exhaust inlet of the duct 14 is formed into a substantially V shape so that the air containing steam and heat generated by the fixing device 23 flows along the wall surface 14e. This can be guided to the discharge port 14d opened at both left and right ends of the fixing device 23 without staying. Therefore, the air flow in the duct 14 becomes smooth, and the temperature rise inside the duct 14 is moderated.

<Third Embodiment> Next, a third embodiment of the present invention will be described with reference to FIG. 8 is a sectional view of the image forming apparatus according to this embodiment.

In FIG. 8, 31 is the exterior of the image forming apparatus main body, 32 is a paper feed tray, 33 is a paper feed roller, 34 is a separation pad, and the paper 40 stacked on the paper feed tray 32 is the paper feed roller 33. It is sent to the pair of transport rollers 35 by. Then, an image is transferred onto the paper 40 by the head 36 a attached to the tip of the ink cartridge 36 on the platen 37. After that, the paper 40 is dried in the drying unit 3.
The image is fixed by being dried at 8, and then discharged to the outside of the apparatus main body by the paper discharge roller pair 38a.

Thus, in the image forming apparatus according to this embodiment, heat and water vapor are generated in the drying unit 38.

Therefore, in the present embodiment, the ink cartridge 36 in which the temperature rise of the main body is not desirable is arranged adjacent to the drying unit 38 and the duct 39. Therefore, also in the present embodiment, the first embodiment
The same effect can be obtained.

[0035]

As is apparent from the above description, according to the present invention, in the image forming apparatus utilizing the heat generating effect in the image formation, the duct for guiding the exhaust containing the water vapor generated in the apparatus is provided, and the exhaust is provided. Is formed in the exterior of the device so as to be continuous with the duct, and an opening for discharging hot air trapped inside the device to the outside of the device is formed in a part of the opening. Since it is provided, it is possible to prevent the occurrence of an abnormal image due to the accumulation of heat and steam inside the main body in the image forming apparatus that does not use a fan, and it is possible to realize cost reduction, low noise, and energy saving. The effect is obtained.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of an image forming apparatus according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram showing a positional relationship between a duct and a fixing device of the image forming apparatus according to the first embodiment of the present invention.

FIG. 3 is a schematic cross-sectional view showing a state where the outer cover of the image forming apparatus according to Embodiment 1 of the present invention is opened.

FIG. 4 is a perspective view of an image forming apparatus according to a second embodiment of the present invention.

FIG. 5 is a perspective view showing an internal configuration of an image forming apparatus according to a second embodiment of the present invention.

FIG. 6 is a schematic diagram showing a positional relationship between a duct and a fixing device in an image forming apparatus according to a second embodiment of the present invention.

FIG. 7 is a perspective view of a duct of the image forming apparatus according to the second embodiment of the present invention.

FIG. 8 is a schematic sectional view of an image forming apparatus according to a third embodiment of the present invention.

FIG. 9 is a schematic sectional view of a conventional image forming apparatus.

[Explanation of symbols]

 1 Exterior 1A Exterior cover 13 Opening 14 Duct 14b Opening 14c Convex 14e Wall surface 23 Fixing device 30 Cartridge

Claims (7)

[Claims] 1. An image forming apparatus utilizing heat generation in image formation, wherein a duct for guiding exhaust gas containing water vapor generated in the apparatus is provided, and an opening for discharging the exhaust gas to the outside of the apparatus is provided on the exterior of the device. An image forming apparatus, wherein the image forming apparatus is formed so as to be continuous with a duct, and an opening for discharging hot air trapped inside the apparatus to the outside of the apparatus is provided in a part of the opening. 2. The image forming apparatus according to claim 1, wherein an opening is provided at an intermediate portion of the duct, and an outside air inlet for guiding outside air is provided inside the duct. 3. The image forming apparatus according to claim 1, wherein the exhaust outlet of the duct is provided above the left and right ends of the fixing device in the sheet material conveying direction. 4. The image forming apparatus according to claim 1, wherein a wall is provided above the exhaust inlet of the duct to form a space between the duct and the exterior. 5. The image forming apparatus according to claim 4, wherein the wall surface is formed in a substantially V shape so that the rising exhaust gas is guided to the exhaust gas outlet of the duct. 6. The duct according to claim 1, wherein the duct is provided in an openable / closable exterior cover, and an opening through which the inner surface of the duct is visible when the exterior cover is opened is provided in a direction invisible to the user. Image forming apparatus. 7. A cartridge detachably mountable to the main assembly of the apparatus, wherein the cartridge is mounted / dismounted at a position adjacent to the fixing device and the duct with the air passage interposed therebetween, and a convex portion is formed on the outer surface of the duct in the air passage direction. When the cartridge is not in the correct position, the operation of closing the outer cover sets the cartridge in the correct position by the convex portion or prevents the operation of closing the outer cover to alert the user. The image forming apparatus according to claim 6.