JPH0876624A - Image forming device - Google Patents

Abstract

PURPOSE: To provide an image forming device capable of reducing the generation of a noise at the time of standing by and power consumption. CONSTITUTION: At the time of forming an image, an optical fan and a cooling fan are rotated by a main body control unit, an opening part 22 provided in the upper part of a heating/fixing part. 16 is closed and the part 16 is set at a fixed temperature. Then, a heat insulating member 5 disposed on the boundary of the heating/fixing part, 16 and a formed image transfer part 15 is moved from a closed state to an opened state and a transfer paper can be set to pass through from the formed image transfer part 15 to the heating/fixing part 16. The transfer paper on which an original image is transferred by the formed image transfer part 15 is shifted to the heating/fixing part 16, to execute an image forming operation. When it is completed, the rotations of the optical fan and the cooling fan are stopped, the opening part 22 is opened and the heating/fixing part 16 is set at the temp. lower than the fixed temp.. Then, the heat insulating member 5 is moved from the opened state to the closed state and becomes a stand-by state, in a state where the transmission of the heat generated in the heating/fixing part 16 to the formed image transfer part, 15 is blocked.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention visualizes a latent image formed on a photoconductor into a toner image by an electrophotographic process,
The present invention relates to an image forming apparatus for forming a document image on a transfer sheet by an electrophotographic process of transferring a toner image on the transfer sheet and fixing the toner image on the transfer sheet.

[0002]

2. Description of the Related Art In an image forming apparatus that forms an original image on a transfer paper based on a latent image on a photoconductor by an electrophotographic process,
First, the latent image of the original image is formed on the photosensitive drum by exposing the original image to the photosensitive drum by the optical system. Then, the latent image is visualized as a toner image by a developing device, and the obtained toner visualized image is transferred and fixed on a transfer paper to form an original image on the transfer paper.

By the way, in this image forming operation, it is necessary to perform fixing at a sufficiently high temperature in the heat fixing section.
On the other hand, in the image forming / fixing unit, if the temperature rises above a predetermined level, development on the photoconductor drum and transfer to the transfer paper may become unstable, and it is necessary to prohibit overheating of the photoconductor beyond the predetermined temperature. There is. Therefore, in the current image forming apparatus, in order to discharge the heat generated in the heating and fixing unit to the outside of the apparatus, the cooling fan is constantly driven to perform air cooling.

[0004]

In the above-described conventional image forming apparatus, since the cooling fan is constantly driven to rotate, noise is generated not only during the image forming operation but also during standby, which is not convenient for the user. May give a pleasant sensation. Further, rotating the cooling fan at all times has a problem in terms of effective use of electric power.

The present invention has been made in view of the current state of the image forming apparatus of this type as described above, and an object thereof is to reduce the generation of noise during standby and reduce the power consumption. It is to provide a possible imaging device.

[0006]

In order to achieve the above object, the invention according to claim 1 is based on an electrophotographic process, wherein a toner image transferred onto a transfer paper by an image forming transfer section is heated by a heat fixing section. An image forming device that forms an original image on the transfer paper by fixing it on the transfer paper, and is movably arranged at a boundary between the heat fixing unit and the image forming transfer unit,
In the closed state, the heat generated in the heat fixing unit is blocked from being transmitted to the image forming transfer unit, and in the open state, the heat shielding that enables the transfer sheet to pass from the image forming transfer unit to the heat fixing unit. Means and an opening / closing control means for moving the heat shield means from the closed state to the open state at the start of the image forming operation and moving the heat shield means from the open state to the closed state at the end of the image forming operation. It is a feature.

[0007] Similarly, in order to achieve the above-mentioned object, the invention according to claim 2 is the invention according to claim 1, wherein the heat blocking means is arranged so as to cover the heat fixing portion, and is driven by a motor. It is characterized in that it is moved so as to open or close a part of the boundary.

Similarly, in order to achieve the above object, the invention according to claim 3 is different from the invention according to claim 1 in that an apparatus cooling fan is rotated at the start of the image forming operation and stopped at the end of the image forming operation. It is characterized by further having.

Similarly, in order to achieve the above object, the invention according to claim 4 is different from the invention according to claim 1 in that the image forming operation is rotated at a predetermined speed at the start of the image forming operation, and the image forming operation is completed at the end of the image forming operation.
It further comprises an apparatus cooling fan that rotates at a speed lower than the predetermined speed.

Similarly, in order to achieve the above object, the invention of claim 5 is different from the invention of claim 1 in that it is provided above the heat fixing portion and is closed at the start of the image forming operation. It is characterized by further having an opening which is opened at the end of the image operation.

Similarly, in order to achieve the above object, the invention according to claim 6 is different from the invention according to claim 1 in that at the time of starting an image forming operation, the heat fixing unit is set to a predetermined temperature to form an image. It is characterized by further comprising temperature setting means for setting the temperature of the heat fixing unit at a temperature lower than the set temperature at the end of the operation.

[0012]

According to the first or second aspect of the present invention, during the image forming operation, the heat shield means arranged at the boundary between the heat fixing section and the image forming transfer section is moved from the closed state to the open state by the control means. The transfer paper is set so that it can pass from the image forming transfer section to the heat fixing section, and the transfer paper on which the original image has been transferred in the image forming transfer section is transferred to the heat fixing section and transferred in the heat fixing section. The transfer image is fixed on the transfer sheet, and the original image is formed on the transfer sheet. Then, when the image forming operation is completed, the heat shield means arranged at the boundary between the heating and fixing section and the image forming and transferring section is moved from the open state to the closed state by the control means, and the heat generated in the heat fixing section is removed. The apparatus is in a standby state with the transmission to the image forming / transferring unit blocked.

According to the invention of claim 3, in addition to the operation of the invention of claim 1 or 2, during the image forming operation,
The apparatus cooling fan is rotationally driven to cool the inside of the apparatus, and the driving of the apparatus cooling fan is stopped when the image forming operation is completed.

According to the invention of claim 4, in addition to the function of the invention of claim 1 or 2, during the image forming operation,
The device cooling fan is rotationally driven at a predetermined speed to enhance the air cooling effect in the device, and at the end of the image forming operation, the device cooling fan is rotationally driven at a speed lower than the predetermined speed while reducing noise. .

According to the invention of claim 5, in addition to the operation of the invention of claim 1 or 2, during the image forming operation,
The opening provided above the heating and fixing unit is closed to keep the inside of the heating and fixing unit in a high temperature state, and at the end of the image forming operation, the opening is opened and the heat in the heating and fixing unit is released to the outside of the apparatus. The overheating of the image forming transfer section due to the heat of the heating and fixing section is prevented.

According to the sixth aspect of the invention, in addition to the operation of the first or second aspect of the invention, the temperature fixing means allows the heat fixing portion to perform a predetermined fixing operation during the image forming operation. The temperature is set to a temperature, and at the end of the image forming operation, the heat fixing unit is set to a temperature lower than the set temperature to prevent the heat of the heat fixing unit from overheating the image forming transfer unit.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is an explanatory view showing the overall structure of the present invention, FIG. 2 is a block diagram showing the structure of the main part of the present embodiment, and FIG. 3 is an explanatory view showing the structure of the heat blocking means.

In this embodiment, as shown in FIG.
An optical unit 1 is arranged in the upper part of the 0, and the optical unit 1 irradiates a document placed on a mounting glass plate on the upper surface of the housing 10 with light from an optical lamp 3 to form an image of the document. An optical system 11 is provided which receives the reflected light and guides it to the photosensitive drum 12 of the image forming transfer section 15 disposed below the optical unit 1 in the housing 10 to perform exposure.

In the image forming transfer section 15, a developing device 13 for developing the latent image of the original image formed on the photosensitive drum 12 by the optical system 11 into a toner image, and the developed toner image are transferred onto a transfer paper. The transfer unit 14 is disposed so as to closely face the peripheral surface of the photosensitive drum 12.

Adjacent to the image forming transfer section 15, the transfer paper on which the toner image transferred from the image forming transfer section 15 is transferred,
A heating / fixing section 16 for performing a fixing operation is arranged by being sandwiched between fixing units 8A heated by a fixing heater 8. As shown in FIG. 3, in the heating and fixing section 16, a fixing unit 8A having a fixing heater 8 is arranged in a case 19 whose upper half is opened, and heat is blocked so as to cover the opening of the case 19. The member 20 is arranged. The heat shield member 20 is a feed roller 18 rotated by a motor 17.
The heat fixing section 16 and the image forming transfer section 15 are connected via a and 18b.
The heat shield member 20 is provided with an opening 22 that is movable so as to close or open the opening 21 between the heat shield member 20 and the heat shield member 20.

In the vicinity of the opening 21, the opening 21
The photo sensor 23 for detecting the closed state by the heat blocking member 20 detects the opening 24 formed when the opening 21 is closed by the heat blocking member 20 near the end of the heat blocking member 20. 25 are provided.

In this embodiment, as shown in FIG. 2, a main body control unit 25 for controlling the whole operation is provided, and the main body control unit 25 has a mode setting key 27a, a stop key 27b and a start key 27c. An operation unit 2 provided with an operator and to which various operation signals are input by the operator
6, various sensors 28, various switches 29, and the thermistor 30 of the heat fixing unit 16 are connected. Similarly, the main control unit 25 includes the motor 1 of the heat fixing unit 16.
7, the photosensors 23 and 25, the series connection circuit of the fixing lamp 31 and the triac 32, and the series connection circuit of the optical lamp 3 and the triac 33 are connected. Further, the main body control unit 25 includes a cooling fan motor 4,
The optical fan motor 2, the overall drive motor 34, and other output elements 35 such as a solenoid, a clutch, a motor, a lamp, and an LED are connected.

On the other hand, the main body control unit 25 causes the heat shield member 5 to move from the closed state to the open state at the start of the image forming operation, and moves the heat shield member 5 from the open state to the closed state at the end of the image forming operation. Opening / closing control means and a temperature setting means for setting the heat fixing section 16 to a predetermined temperature at the start of the image forming operation and setting the heat fixing section 16 to a temperature lower than the set temperature at the end of the image forming operation are provided. Has been. Similarly, the main body control unit 25 includes fan control means for rotating a cooling fan and an optical fan at the time of image forming operation and stopping at the time of ending the image forming operation, and the opening 22 at the start of the image forming operation and at the end of the image forming operation. An opening control means for opening is provided.

The operation of this embodiment having such a configuration is shown in FIG.
It will be described with reference to FIGS. FIG. 4 is a flow chart showing the overall operation of this embodiment, FIG. 5 is a flow chart showing the opening operation of the heat cutoff means of this embodiment, and FIG. 6 is a flow chart showing the closing operation of the heat cutoff device of this embodiment.

In step S1 of FIG. 4, the main switch of the image forming device is turned on, the process proceeds to step S2, the image forming device enters a standby state, and it is determined in step S3 whether or not the start key 27c has been pressed. . If the determination in step S3 is YES, the process proceeds to step S4, the optical fan motor 2 and the cooling fan motor 4 are activated, and air cooling by the fan to the inside of the apparatus centering on the optical unit 1 and the image forming transfer section 15 is performed. Be started.

Next, in step S5, the motor 17 is driven by the main body control unit 25, and the heat blocking member 5 is moved from the closed state (position shown in B) shown by the dotted line in FIG.
After moving to the open state (position indicated by A) shown by the solid line, the opening 21 is formed at the boundary between the heat fixing section 16 and the image forming transfer section 15. Then, in step S6, the fixing heater 8 is raised to the operating temperature T0 by the main body control unit 25, and the process proceeds to step S7 to start the copy cycle operation. In this case, the opening 22 is closed by the main body control unit 25.

In this copy cycle operation, the latent image of the original image formed by the optical unit 1 on the photosensitive drum 12 is visualized as a toner image by the developing device 13, and the toner on the photosensitive drum 12 is transferred by the transfer device 14. The image is transferred to the transfer paper. Then, the transfer paper on which the toner image is transferred is transferred to the heat fixing unit 16 through the opening 21,
The original image is fixed on the transfer paper by the fixing unit 8A.

In step S8, it is determined whether or not the above-described copy cycle operation is completed. If the determination in step S8 is YES, the process proceeds to step S9, in which the main body control unit 25 causes the optical fan motor to operate. 2 and the operation of the cooling fan motor 4 are stopped. Next, in step S10, the motor 17 is driven by the main body control unit 25, the heat blocking member 5 moves from the open state shown by the solid line in FIG. 3 to the closed state shown by the dotted line, and the opening 21 is closed and heated. The fixing unit 16 and the image forming transfer unit 15 are thermally blocked. Then, in step S11, the fixing heater 8 is lowered from the operating temperature T0 to the standby temperature T1 by the main body control unit 25, and in step S12, the whole drive motor 34 is driven by the main body control unit 25. The operation is stopped, the opening 22 is opened, and the image forming operation is completed.

In this case, the movement of the heat shield member 5 from the closed state to the open state in step S5 is performed as shown in the flowchart of FIG. 5, the motor 17 is driven to rotate normally in step S21, and the process proceeds to step S22. With photo sensor 23
Is determined whether or not the open state of the opening 21 is detected,
If the determination in step S22 is YES, step S2
In 3, the drive of the motor 17 is stopped by the main body control unit 25.

The movement of the heat shield member 5 from the open state to the closed state in step S10 is performed as shown in the flowchart of FIG. 6, the motor 17 is reversely driven in step S31, and the process proceeds to step S32 to take a photo. Sensor 25
Is determined whether or not the open state of the opening 24 is detected,
If the determination in step S32 is YES, then step S3
In 3, the drive of the motor 17 is stopped by the main body control unit 25.

As described above, according to this embodiment, when the image forming operation is completed and the apparatus is in the standby state, the set temperature of the fixing heater 8 of the heat fixing section 16 is lowered and the opening 22 is opened.
The heat blocking member 20 moves from the open state to the closed state, the heat fixing unit 16 and the image forming transfer unit 15 are heat blocked, and the photoconductor drum 12 is prevented from being overheated by the heat of the heat fixing unit 16. Therefore, the photosensitive drum 12 does not malfunction during image formation. Further, in the standby state, the optical fan motor 2 and the cooling fan motor 4 are stopped, so that noise is not generated during standby and power consumption can be reduced.

When the image forming operation is started, the set temperature of the fixing heater 8 of the heating and fixing section 16 is raised and the opening 2
2 is closed, the heat shield member 20 is moved from the closed state to the open state, and the transfer paper on which the original image is transferred becomes the image forming transfer section 1.
A stable fixing operation is performed by the fixing heater 8 which is transferred to the heating and fixing unit 16 from 5 and is heated sufficiently.
Further, during the image forming operation, the optical fan motor 2 and the cooling fan motor 4 are driven so that the inside of the apparatus is not overheated and a high quality image of the original image is formed.

In this embodiment, the case where the optical fan motor and the cooling fan motor are stopped in the standby state has been described. However, the present invention is not limited to this embodiment, and the optical fan motor in the standby state. It is also possible to reduce the number of rotations of the cooling fan motor compared to that during the image forming operation.

[0034]

According to the first or second aspect of the present invention, during the image forming operation, the transfer image is fixed on the transferred transfer paper by the heating and fixing section, and the original image is transferred onto the transfer paper. When the image forming operation is completed and the image forming operation is completed, the heat blocking means arranged at the boundary between the heat fixing section and the image forming transfer section,
Since it moves from the open state to the closed state and the heat generated in the heat fixing section is blocked from being transferred to the image forming transfer section, the heat generated in the heat fixing section is prevented from overheating the image forming transfer section. ,
The image forming transfer section always operates stably, and high quality image forming operation can be performed. According to the invention of claim 3,
In addition to the effect obtained by the invention according to claim 1 or claim 2, since the device cooling fan rotates during the image forming operation and stops at the end of the image forming operation, cooling of the image forming transfer portion by the device cooling fan is performed. Therefore, it is possible to efficiently perform the operation without generating noise during standby and with reduced power consumption. According to the invention of claim 4, claim 1
In addition to the effect obtained by the invention as set forth in claim 2, the device cooling fan rotates at a predetermined speed at the start of the image forming operation and at a speed slower than the predetermined speed at the end of the image forming operation. It is possible to efficiently cool the image forming transfer portion by the cooling fan while reducing noise and power consumption during standby. According to the invention of claim 5, in addition to the effect obtained by the invention of claim 1 or 2, the opening provided above the heat fixing portion is closed during the image forming operation, and the image forming operation is performed. Since it is opened at the end, it becomes possible to efficiently adjust the temperature of the heating and fixing section in accordance with the fixing operation. According to the invention of claim 6, in addition to the effect obtained by the invention of claim 1 or 2, the temperature setting means sets the heat fixing portion to a predetermined temperature at the start of the image forming operation, and the image forming operation is performed. At the end of the operation, the heating and fixing unit is set to a temperature lower than the set temperature, so that the temperature of the heating and fixing unit can be efficiently adjusted according to the fixing operation.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an overall configuration of an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a main part of the embodiment.

FIG. 3 is an explanatory diagram showing a configuration of a heat blocking means portion of the embodiment.

FIG. 4 is a flowchart showing the overall operation of the same embodiment.

FIG. 5 is a flowchart showing an opening operation of the heat cutoff means of the embodiment.

FIG. 6 is a flowchart showing a closing operation of the heat shutoff device of the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical unit 2 Optical fan motor 3 Optical lamp 4 Cooling fan motor 5 Heat blocking member 8 Fixing heater 8A Fixing unit 10 Enclosure 15 Image forming transfer unit 16 Heating fixing unit 17 Motor

Claims (6)

[Claims] 1. An image forming apparatus for forming an original image on a transfer sheet by fixing a toner image transferred onto a transfer sheet by an image forming transfer section on the transfer sheet based on an electrophotographic process. Yes, it is movably arranged at the boundary between the heat fixing section and the image forming transfer section. In the closed state, the transfer of heat generated in the heat fixing section to the image forming transfer section is blocked, and in the open state. A heat blocking unit that allows the transfer sheet to pass from the image forming transfer unit to the heat fixing unit, and at the start of the image forming operation, the heat blocking unit is moved from the closed state to the open state to end the image forming operation. An image forming apparatus characterized in that the image forming apparatus further comprises opening / closing control means for moving the heat shield means from an open state to a closed state. 2. The heat blocking means is arranged so as to cover the heat fixing section, and is driven by a motor to move so as to open or close a part of the boundary. Imager. 3. The image forming apparatus according to claim 1, further comprising an apparatus cooling fan that rotates at the start of the image forming operation and stops at the end of the image forming operation. 4. When the image forming operation is started, it rotates at a predetermined speed,
The image forming apparatus according to claim 1, further comprising an apparatus cooling fan that rotates at a speed lower than the predetermined speed when the image forming operation ends. 5. The image forming apparatus according to claim 1, further comprising an opening provided above the heat fixing unit, the opening being closed at the start of the image forming operation and opened at the end of the image forming operation. 6. The apparatus further comprises temperature setting means for setting the heating and fixing section to a predetermined temperature at the start of the image forming operation and for setting the heating and fixing section at a temperature lower than the set temperature at the end of the image forming operation. The image forming apparatus according to claim 1, wherein: