JP2000293075A - Recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To discharge the heat of a fixing part to the outside of the device without using a cooling fan. SOLUTION: By arranging the fixing part 30 above a transfer position and at the uppermost part of the device, the other component elements in the device are hardly affected by the heat from a fixing part 30. Furthermore, an inclined air path 38 (42) is formed by providing an auxiliary roller 34 above a heat insulating cover 33 surrounding a fixing roller 31, and air inside the device is discharged to the outside of the device by generating natural convection in the air path, whereby the heat of the fixing part 30 is discharged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus such as a printer, a facsimile, a copying machine, and the like, which forms a toner image on a photosensitive member, transfers the toner image to recording paper, and then heats and fixes the toner image.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 3, in a recording apparatus of this type, a sheet feeding cassette 2 mounted on a bottom portion of an apparatus main body 1 and a recording sheet 3 fed from the sheet feeding cassette 2 are changed in direction. Roller 4, which feeds the recording paper 3 substantially horizontally, a pre-transfer guide 5 and a post-transfer guide 6 which are provided to guide the recording paper 3 substantially horizontally, a toner cartridge 8 having a photoconductor 7, and a photoconductor 7 A laser scanning unit 9 for forming an electrostatic latent image on the recording medium, a transfer roller 10 for transferring the toner image formed on the photoconductor 7 to recording paper, and a fixing unit 12 disposed downstream of the post-transfer guide 6. Equipped,
The toner image is transferred to the recording paper 3 fed from the paper feed cassette 2 by the transfer roller 10, fixed by the fixing unit 12, and discharged.

Here, the fixing unit 12 includes a heat fixing roller 13 for heating and melting the toner and fixing the toner on the recording paper. Since the temperature of the fixing roller 13 and its surroundings become high, heat is radiated to the surroundings. I have. Therefore, a fan (not shown) is provided to release the high heat generated in the fixing section from the inside of the apparatus to the outside. The mounting position of this fan is
Since it is limited by the arrangement of the substrate and the like, it is difficult in design to attach it to a position adjacent to the fixing unit. Therefore, the fixing unit and the fan cannot be arranged adjacent to each other, and a duct connecting the fixing unit and the fan is provided in the apparatus.

[0004] In addition, since the fan needs to rapidly discharge the heat generated in the fixing unit to the outside and cool it so that the inside of the apparatus does not reach a high temperature, a fan rotating at a high speed is used (for example, such a fan). , About 2,000 times / minute), and a dedicated motor is connected for this purpose.

[0005]

However, in the conventional configuration, since the photosensitive member 7 is arranged at substantially the same height as the fixing unit 12, the fixing unit is cooled even though the inside of the apparatus is cooled by a fan. 12 is easily transmitted to the photoconductor 7,
Therefore, the photoconductor 7 is not excessively heated.
It is necessary to increase the distance between the photoconductor 7 and the fixing unit 12 (for example, about 120 mm), and the apparatus has been increased in size.
Moreover, because it requires a cooling fan and duct,
The size of the equipment has increased and the cost has increased,
In addition, the device must be designed to secure a space for installing a fan or a duct, and there is a problem that the degree of freedom in design is greatly limited.

Further, since the fan used conventionally rotates at high speed by a dedicated motor, there is also a problem that noise is loud and power consumption cannot be ignored.

The present invention has been made in view of the above problems, and efficiently discharges heat from the fixing unit to the outside of the apparatus without using a cooling fan, thereby reducing the size and cost of the apparatus. It is an object of the present invention to provide a recording device that can perform the recording.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention has a configuration in which the recording paper is transported from the bottom to the top along the conveyance path of the recording paper before and after the transfer position, and is used to guide the recording paper. A fixing unit is arranged above the conveyance guide.The fixing unit is further provided with a heat shield cover that houses the fixing roller and the pressure roller, and an auxiliary cover is arranged on the upper surface of the heat shield cover. Then, an air passage that flows upward from an inflow port communicating with the internal space of the apparatus to a discharge port communicating with the outside of the apparatus is formed. According to this configuration, the air heated by the heat generated by the fixing unit flows upward through the above-described air passage, whereby natural convection occurs in the air passage on the upper surface of the heat shield cover that covers the fixing roller that is the heating element. An air flow that flows out of the device to the outside of the device is generated, discharging heat trapped in the device and drawing in outside air to cool the fixing unit and its surroundings. The influence can be avoided, so that the fan and the duct conventionally used can be omitted to reduce the size and cost of the apparatus, and further, eliminate the fan noise and reduce the power consumption. In addition, since heat is hardly transmitted to the lower side, the photoconductor located below the fixing unit is hardly affected by the heat of the fixing unit, so that the interval between the photoconductor and the fixing unit can be shortened. And cost can be reduced.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In one embodiment of the present invention, recording means for forming a toner image on a photoreceptor, transfer means for transferring the toner image to recording paper, and fusing and fixing the toner on the recording paper. In a recording apparatus having a fixing unit and the like, a conveyance guide that guides recording paper before and after a transfer position is arranged so that the recording paper is guided upward from below the transfer position through the transfer position and above the transfer guide. A fixing unit is provided, and the fixing unit is provided with a heat shield cover for housing the fixing roller and the pressure roller, and the heat shield cover is provided with a recording paper entrance below, and a position higher than the entrance. A recording paper outlet, the upper surface of which is inclined so as to be higher toward the recording paper outlet, and an air passage inclined between the upper surface and the upper surface of the heat shield cover. And its air passage The inlet air leading into the apparatus main body at the lower end, in which a configuration of arranging the auxiliary cover to form an outlet air leading to the outside of the apparatus to the upper end. According to the present invention, the upward air passage from the inside of the apparatus to the outside of the apparatus is formed by the upper surface of the heat shield cover of the fixing unit and the auxiliary cover as described above, so that the air flow flowing out of the apparatus by natural convection flows in the air passage. The generated heat is discharged inside the apparatus, and at the same time, the outside air is drawn in to cool the fixing section and its surroundings, so that the fan and duct can be omitted.
Therefore, not only the size and cost of the device can be reduced, but also fan noise can be eliminated and power consumption can be reduced. In addition, the distance between the fixing unit and the photosensitive member below the fixing unit can be reduced, and from this point of view, the size and cost of the apparatus can be reduced.

In another embodiment of the present invention, the discharge port at the upper end of the air passage formed on the upper surface of the heat shield cover is disposed adjacent to the exit of the recording paper, and the recording paper discharged from the exit is used for the discharge port. It is configured so that air can be sucked out from the outlet of the air passage. With this configuration, the flow of air generated in the air passage by natural convection is promoted by the air suction effect by the running of the recording paper, the air flow rate is increased, and the heat release effect in the apparatus can be increased.

In still another embodiment of the present invention, the fixing unit is disposed near an outer cover constituting the upper surface of the apparatus body,
An inclined air passage is formed between the auxiliary cover of the fixing unit and the exterior cover, and at the lower end of the air passage, an air inlet for air flowing into the apparatus main body is provided, and at the opposite end, air flowing to the outside of the apparatus is formed. The outlet is formed. With this configuration, inclined air passages are respectively formed between the heat shield cover and the auxiliary cover, and between the auxiliary cover and the outer cover. Releases heat to the outside. As a result, the inside of the apparatus can be more reliably cooled, and the heat transfer to the outer cover can be prevented and the temperature can be kept low.

Hereinafter, a preferred embodiment of the present invention shown in the drawings will be described. FIG. 1 is a schematic sectional view showing a schematic configuration of a recording apparatus according to an embodiment in which the present invention is applied to a facsimile apparatus. FIG. 2 is an enlarged schematic sectional view showing a fixing section of the recording apparatus and its vicinity. Reference numeral 15 denotes an apparatus main body that accommodates each element described below. In the present specification, the device main body means not only a housing that forms the outer shape of the device, but also
It also includes an internal chassis, a rear chassis, and the like fixed to the housing. Reference numeral 16 denotes a paper cassette which can be attached to and detached from the bottom portion of the apparatus main body 15, reference numeral 17 denotes a paper feed roller for feeding out recording paper 18 from the paper supply cassette 16, and reference numeral 19 denotes a paper feed guide for guiding the recording paper 18 upward. Configure the paper feed unit. Reference numeral 20 denotes a registration roller provided at a predetermined position in the apparatus main body 15, and supplies the recording paper 18 to the transfer position at a proper timing.

Reference numeral 21 denotes a toner cartridge, a photosensitive member 22, a charger for uniformly charging the photosensitive member 22, a toner hopper containing toner, a developing device for applying toner to a latent image on the photosensitive member 22, and a photosensitive device. A waste toner unit and the like for removing and storing residual toner on the body 22 are provided. The toner cartridge 21 is disposed at an intermediate position of the apparatus main body 15 so that the photosensitive member 22 is oriented horizontally. A laser scan unit (LSU) 24 scans the surface of the photoconductor 22 with a laser beam to form a latent image.

Reference numeral 25 denotes a transport unit, which is disposed to face the photoconductor 22 and transfers a toner image of the photoconductor 22 to recording paper, and a recording roller 18 which is fed from a paper feeding unit. It is provided with a substantially linear conveyance guide 27 formed of a single member and a pinch roller 28 for pressing the recording paper against the registration roller 20, which is disposed so as to be guided upward from the bottom through the transfer position. I have.

Reference numeral 30 denotes a fixing unit, which is disposed above the transport guide 27, at a position higher than the substrate mounting area in the apparatus, and near the upper end of the apparatus main body 15. The fixing unit 30 includes a fixing roller 31 for applying high heat to the recording paper to fix the toner on the recording paper, a pressing roller 32 for pressing the recording paper against the fixing roller 31, and the fixing roller and the pressing roller therein. A heat shield cover 33 to be accommodated, an auxiliary cover 34 disposed at a position covering the side and top surfaces of the heat shield cover 33, and the like are provided. The heat shield cover 33 has a recording paper inlet 33a at the lower end, and a guide 33b for guiding the recording paper obliquely upward from the entrance 33a inside. The recording paper is further positioned higher than the entrance 33a. An outlet 33c for discharging the sheet to the outside of the apparatus is provided, and a discharge roller 36 is disposed at the outlet 33c. Also, the heat shield cover 33
The upper surface 33e of the recording paper exit 3
The shape is inclined so as to rise in the direction toward 3c. The auxiliary cover 34 forms the air passage 38 between the side surface and the upper surface of the heat shield cover 33 so that the heat shield cover 3
3 are arranged at an appropriate interval. As described above, since the upper surface 33e of the heat shield cover 33 is inclined so as to rise in the direction from the fixing roller 31 side toward the recording paper outlet 33c, the air passage 38 formed thereon also covers the recording paper. It is inclined so as to rise in the direction toward the outlet 33c. At the lower end of the air passage 38, on the side of the fixing roller 31, which is a heat source, an air inlet 39 communicating with the space inside the apparatus is formed. At the upper end of the air passage 38, air is discharged out of the apparatus. An outlet 40 is formed. The outlet 40 is provided adjacent to the recording paper outlet 33c, and the recording paper discharged from the outlet 33c sucks air from the outlet 40 of the air passage 38. Although the inlet 39 is formed in the auxiliary cover 34 in the illustrated embodiment, an appropriate gap may be formed between the auxiliary cover 34 and the heat shield cover 33, and the gap may be used as the inlet. . In addition, although the inlet 39 is simply shown as a hole in the drawing, it may be in the form of a louver that facilitates the flow of air.

The heat shield cover 33 and the auxiliary cover 34 constituting the fixing section 30 may be manufactured as an integral structure or may be manufactured as separate parts. It is preferable because it can be selected. Since the heat shield cover 33 is disposed at a position surrounding the fixing roller 31 which is a heat source, the temperature may rise to, for example, about 150 ° C., and therefore, a heat resistant material such as PPS may be used. A high-performance resin is used. on the other hand,
Since the air passage 38 is interposed between the auxiliary cover 34 and the heat source, the temperature is considerably lower than that of the heat shield cover 33, for example, 100 ° C. or less. A resin having heat resistance of about 100 ° C. such as denatured PPO is used.

The fixing section 30 is disposed near the upper end of the apparatus main body 15, and the outer cover 15a and the auxiliary cover 34 constituting the upper surface of the apparatus main body 15 are appropriately separated from each other. An inclined air passage 42 is formed between the air passage 42 and the auxiliary cover 34. And
At the lower end of the air passage 42, an air inlet 43 communicating with the inside of the apparatus main body is formed, and at the opposite end, an air outlet 44 communicating with the outside of the apparatus is formed.

The recording apparatus is not provided with a fan or a duct for cooling the fixing unit 30.

In the recording apparatus having the above configuration, the paper feed cassette 1
The recording paper 18 fed from the paper feed roller 17 by a paper feed roller 17 is sent upward by a registration roller 20 and a pinch roller 28, and a toner image is formed on a photosensitive member 22 of a toner cartridge 21 in parallel with the conveyance of the recording paper 18. , Recording paper 18
Is passed between the photosensitive member 22 and the transfer roller 26, the toner image is transferred to the recording paper 18. Thereafter, the recording paper 18 is sent to the upper fixing unit 30, and the toner image is heated by the fixing unit 30. It is fused and fixed, and is discharged out of the apparatus.

During this recording operation, the fixing roller 31 is at a high temperature and emits heat to the surroundings. However, the heated air tends to flow upward, and the recording paper 18 is conveyed upward. The recording paper 18
Therefore, the heat from the fixing roller 31 is not transmitted much downward, but is mainly transmitted upward. Then, the upper surface of the heat shield cover 33 is heated by this heat, and the air in the air passage 38 contacting the upper surface is heated, so that the air in the air passage 38 flows upward in the air passage 38 by natural convection. As a result, the air is discharged out of the apparatus through the outlet 40, and the air in the apparatus is drawn into the air passage 38 from the inflow port 39. Thus, above the heat shield cover 33, as indicated by the arrow, the air that is drawn into the air passage 38 from the inside of the device through the inflow port 39, flows upward through the air passage 38, and is discharged from the discharge port 40. The flow is generated stably, and the recording paper runs near the discharge port 40,
Air is sucked out from the air passage 38, and the amount of air flowing through the ventilation passage 38 increases. Similarly, an air flow indicated by an arrow is generated in the air passage 42 above the air passage 38 by natural convection. The heat from the fixing unit 30 is discharged to the outside of the apparatus by the airflow, and the air outside the apparatus is drawn into the apparatus from an appropriate gap in the apparatus main body 15, whereby the inside of the apparatus is cooled and the inside of the apparatus is cooled. Excessive heat is discharged. Further, heat transfer to the exterior cover 15a is prevented, and the temperature rise of the exterior cover 15a is suppressed to a low level.

Further, as described above, since little heat is transmitted downward from the fixing unit 30, the temperature does not rise so much even in the transport guide 27 and the toner cartridge 21 provided immediately below the fixing unit 30. For example, the temperature in the vicinity of the fixing unit 30 does not exceed 80 ° C. For this reason, these materials do not need much heat resistance, and general-purpose resins such as polystyrene can be used. Also, the photoconductor 22 is less likely to be heated by the fixing unit 30, so that the distance between the photoconductor 22 and the fixing unit 30 can be reduced as compared with a conventional horizontal arrangement, and the recording apparatus can be downsized. it can. Further, since the fixing unit 30 is located at a position higher than the substrate mounting area, the substrate is not heated.

As described above, in the recording apparatus of this embodiment,
Even without providing a fan or a duct for forcibly cooling the fixing unit 30, it is possible to effectively generate an airflow due to natural convection on the upper surface of the fixing unit and discharge heat from the fixing unit to the outside of the apparatus.
For this reason, since no fan or duct is required, the size and cost of the apparatus can be reduced accordingly. Moreover, fan noise is eliminated and power consumption can be reduced.

[0023]

As described above, the present invention provides a conveyance guide for guiding recording paper before and after the transfer position so that the recording paper is guided upward from below the transfer position through the transfer position. A fixing unit is disposed above the fixing unit, and the fixing unit is provided with a heat shield cover that houses a fixing roller and a pressure roller, and the heat shield cover is provided with a recording paper entrance below. A recording paper outlet is provided at a position higher than the entrance, and the upper surface is inclined so as to be higher toward the recording paper outlet. And an auxiliary cover so as to form a closed air passage, and to provide an air inlet at the lower end of the air passage to the space inside the device and an air outlet at the upper end to form an air outlet to the outside of the device. The transfer gas And the photoreceptor are less susceptible to the heat from the fixing unit, so that the distance between the fixing unit and the photoreceptor can be reduced, and the air inside the device is drawn into the air passage formed in the fixing unit. An air flow to be discharged to the outside can be generated by natural convection, and the heat of the fixing section can be discharged to the outside of the apparatus and the heat that tends to stay inside the apparatus can be discharged by the air flow. The fan and the duct used can be omitted, so that not only the size and cost of the apparatus can be reduced, but also the fan noise can be eliminated and the power consumption can be reduced.

Here, the outlet at the upper end of the air passage formed on the upper surface of the heat shield cover is disposed adjacent to the outlet of the recording paper, and the outlet of the air passage is discharged by the recording paper discharged from the outlet. When air is sucked out of the apparatus, the air flow generated in the air passage by natural convection can be promoted by the air sucking effect by the running of the recording paper, and the air flow rate is increased to increase the heat releasing effect in the apparatus. The effect that it can be obtained is obtained.

Further, the fixing unit is disposed near the outer cover constituting the upper surface of the apparatus main body, and an inclined air passage is formed between the auxiliary cover of the fixing unit and the outer cover. Has a structure in which an air inlet communicating with the inside of the device main body is formed at the opposite end, and an air outlet for air communicating with the outside of the device is formed at the opposite end, and between the heat shield cover and the auxiliary cover, and between the auxiliary cover and the outer cover. The inclined air passages can be formed between them, and the air flow by natural convection can be generated in each ventilation passage to release the heat of the fixing unit to the outside. The effect is obtained that the heat transfer to the cover can be prevented and the temperature can be kept low.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a schematic configuration of a recording apparatus according to an embodiment in which the present invention is applied to a facsimile apparatus.

FIG. 2 is a schematic cross-sectional view showing, in an enlarged manner, a fixing unit of the recording apparatus shown in FIG. 1 and the vicinity thereof;

FIG. 3 is a schematic sectional view showing an example of a conventional recording apparatus.

[Explanation of symbols]

 REFERENCE SIGNS LIST 15 apparatus main body 15 a exterior cover 16 paper feed cassette 17 paper feed roller 18 recording paper 20 registration roller 21 toner cartridge 22 photoconductor 24 laser scan unit 25 transport unit 26 transfer roller 27 transport guide 30 fixing unit 31 fixing roller 32 pressure roller 33 Heat shield cover 34 Auxiliary cover 36 Discharge roller 38 Air passage 39 Inlet 40 Discharge outlet 42 Air passage 43 Inlet 44 Discharge outlet

Claims (3)

[Claims] A recording unit that forms a toner image on a photoreceptor; a transfer unit that transfers the toner image to recording paper; a paper supply unit that supplies the recording paper; and a recording paper that is fed from the paper supply unit A conveyance guide arranged to guide the paper from the lower part of the transfer position to the upper part through the transfer position, a fixing unit arranged above the conveyance guide, and an apparatus main body for accommodating these components, A fixing roller that applies high heat to the recording paper to fix the toner on the recording paper; a pressure roller that presses the recording paper against the fixing roller; and a heat shield cover that houses the fixing roller and the pressure roller. A heat shield cover having a recording paper entrance below, a recording paper exit at a position higher than the entrance, and a slope inclined so that the upper surface rises toward the recording paper exit. , Its heat shield cover And an upper surface of the air passage is formed so as to form an inclined air passage, and at the lower end of the air passage, an air inlet for communicating with the inside of the device main body, and at an upper end thereof, an air outlet for communicating with the outside of the device. A recording device comprising: an auxiliary cover; 2. A discharge port at an upper end of an air passage formed on an upper surface of the heat shield cover is provided adjacent to an exit of the recording paper, and the recording paper discharged from the exit discharges the air passage. 2. The recording apparatus according to claim 1, wherein air is sucked from the outlet. 3. A fixing unit is disposed near an exterior cover constituting an upper surface of the apparatus main body, and forms an inclined air passage between an auxiliary cover of the fixing unit and the exterior cover.
3. The recording apparatus according to claim 1, wherein a lower end of the air passage is formed with an air inlet for communicating with the inside of the apparatus main body, and an opposite end is formed with an air outlet for discharging air to the outside of the apparatus. .