JPH09101711A - Image forming device - Google Patents

Abstract

(57) [Abstract] (Correction) [PROBLEMS] To provide an image forming apparatus capable of stably performing a phase transition work without sacrificing the opening / closing operability of a panel as much as possible. An image forming apparatus of the present invention is provided with an image forming mechanism including a fixing device in a housing having an openable and closable panel, and the fixing device 6 has a crystalline outer surface of a fixing roller and a non-crystalline material. The fixing roller 9 is provided with a phase transition layer that is capable of undergoing a phase transition with the crystallinity, and the fixing roller 9 is heated by the heat energy generated during the phase transition from amorphous to crystalline and the temperature of the outer peripheral surface thereof is The image forming apparatus in which the ascent is promoted is provided with a panel opening prohibiting means for prohibiting the opening of the panel, and the panel opening prohibiting means performs the panel 2 operation during the phase transition operation between the crystalline and the amorphous phase transition layers. Prohibit the establishment of.

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 such as a copying machine, a printer and a facsimile, and in particular, an image forming mechanism including a fixing device is provided in a housing having a panel that can be opened and closed. Is provided on the outer peripheral surface of the fixing roller with a phase transition layer made of a substance capable of phase transition between crystalline and amorphous. The fixing roller is heated at the time of the phase transition from amorphous to crystalline by heating. The present invention relates to an image forming apparatus in which a temperature rise of an outer peripheral surface of the image forming apparatus is promoted by heat energy generated in

[0002]

2. Description of the Related Art In an image forming apparatus, toner is attached to an electrostatic latent image formed on a photoconductor to make it visible as a toner image, and the visualized toner image is transferred to a recording sheet.
It is known that the toner adhering to the recording sheet (conveying paper) is then softened by heating and the toner is fused to the recording sheet by pressurization to fix the toner image. The fixing device incorporated in the image forming apparatus includes a pressure roller and a fixing roller that face each other and have a conveyance path for a recording sheet between them. In the fixing roller, a release layer for preventing toner adhesion is formed on the outer circumference of a hollow cylindrical cored bar made of, for example, aluminum or iron. A heater composed of, for example, a halogen lamp is provided inside the fixing roller, and the fixing roller is configured to heat from the inside.

In a fixing device of this type of structure, the temperature of the outer surface of the fixing roller is warmed up in advance until the temperature required for fixing is reached. Conventionally, this warm-up requires a long time, and in general, a structure has been adopted in which the fixing roller is preheated when the main power supply is turned on, but the power is wasted.

[0004]

Therefore, the applicant of the present invention has found that a substance capable of phase transition between amorphous and crystalline (for example, JP-A-7-140823) is provided on the outer periphery of a hollow cylindrical core metal.
The present invention has proposed a fixing roller having a structure in which a phase-transition layer composed of the above-mentioned publication) is provided and the phase-transition layer is covered with a protective layer. According to this fixing roller, thermal energy is generated by the phase transition from the amorphous phase to the crystalline phase of the phase transition layer due to heating, so that the temperature rise of the outer peripheral surface of the fixing roller is promoted and the warming-up time is shortened. To be

On the other hand, in the fixing roller of this type, in order to reuse the thermal energy generated by the phase transition layer, the crystallized phase transition layer must undergo a phase transition from crystalline to amorphous. I have to. There is a method by ion implantation for the phase transition of this phase transition layer from crystalline to amorphous. Usually, this crystallized phase transition layer is heated and once melted, and then rapidly cooled to a supercooled state. Need to do. When the cooling rate of the substance forming the phase transition layer is equal to or lower than a certain cooling rate determined by the substance, crystallization starts again near the melting point of the substance, and the substance forming the phase transition layer is separated from the crystalline substance. This is because the crystal phase cannot be changed.

In the image forming apparatus of this type, if the panel is inadvertently opened during the phase transition work between the crystalline and amorphous of the substance forming the phase transition layer, the following inconvenience occurs. .

For example, when the panel is opened during the phase transition work in which the substance forming the phase transition layer undergoes a phase transition from amorphous to crystalline, outside air flows into the inside of the apparatus main body, so that amorphous to crystalline. The crystallization energy generated at the time of phase transition cannot be effectively used, and the energy use efficiency decreases.
Also, in order to amorphize the material forming the phase change layer in the crystalline state, when the material forming the phase change layer is heated and melted, when the panel is opened, the air inside the device body is In some cases, the melting temperature may not be accurately detected, and the crystallized substance may remain partially unmelted. Furthermore, if the panel is opened during the phase transition work of cooling the substance forming the phase transition layer from the molten state, the crystallization start temperature of the substance forming the phase transition work cannot be accurately detected, and the amorphous state is not detected. The cooling of the phase transition work may be completed without the qualification being completed.

As described above, during heating of the substance forming the phase transition layer to change the phase from amorphous to crystalline, the substance forming the phase transition layer to change the phase from crystalline to amorphous is heated. During heating / melting, during cooling of the substance constituting the phase transition layer in the molten state in order to cause a phase transition from crystalline to amorphous,
If the panel is inadvertently opened, a stable phase transition does not occur. In other words, when such a situation occurs, the thermal energy generated during the phase transition of the substance forming the phase transition layer from amorphous to crystalline is effectively used to raise the temperature of the outer peripheral surface of the fixing roller. Can not be promoted. Therefore, it is possible to prohibit the opening of the panel while the image forming apparatus is in operation. However, in consideration of the operability of opening and closing the panel, it is preferable that the panel is placed so that it can be opened and closed as much as possible.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an image forming apparatus capable of performing a stable phase transition work without sacrificing the opening / closing operability of the panel as much as possible. To provide.

[0010]

An image forming apparatus according to claim 1, wherein an image forming mechanism including a fixing device is provided in a housing having an openable / closable panel, and the fixing device has an outer peripheral surface of a fixing roller. Is provided with a phase transition layer made of a substance capable of phase transition between crystalline and amorphous, and the fixing roller is provided with a thermal energy generated during the phase transition from amorphous to crystalline by heating. In an image forming apparatus in which the temperature rise of the outer peripheral surface is promoted, a panel opening prohibiting means for prohibiting opening of the panel is provided, and the panel opening prohibiting means is provided between the crystalline phase and the amorphous phase transition layer. The opening of the panel is prohibited during the phase transition work.

According to a second aspect of the invention, in the image forming apparatus according to the first aspect, the phase change operation is a heating operation of the phase change layer from amorphous to crystalline. .

The invention according to claim 3 is characterized in that the phase change operation is a heating / melting operation of the phase change layer from crystalline to amorphous.

The invention according to claim 4 is characterized in that the phase change work is heating / melting work from crystalline to amorphous of the phase change layer and cooling work after melting.

According to a fifth aspect of the present invention, in the image forming apparatus according to the first aspect, the phase transition work is performed when the main switch is turned off.

According to a sixth aspect of the present invention, in the image forming apparatus according to the fifth aspect, the phase transition work raises the temperature of the phase transition layer higher than room temperature and the amorphization temperature of the phase transition layer. It is performed at the start of the preheating mode for maintaining the preheating temperature slightly lower than that.

According to a seventh aspect of the present invention, in the image forming apparatus according to the sixth aspect, when the main switch is turned off while the phase transition layer is maintained at the preheating temperature, the phase transition work is performed. Is prohibited.

[0017]

According to the invention described in any one of claims 1 to 7, the panel opening prohibiting means is provided for the panel during the phase transition operation between the crystalline and amorphous of the substance constituting the phase transition layer. Prohibition of opening.

According to the second aspect of the invention, it is possible to effectively utilize the thermal energy generated when the substance constituting the phase transition layer undergoes the phase transition from amorphous to crystalline.

According to the third aspect of the invention, it is possible to ensure the melting of the substance constituting the phase transition phase when the substance constituting the phase transition layer undergoes a phase transition from crystalline to amorphous. it can.

According to the fourth aspect of the present invention, the phase transition of the substance constituting the phase transition layer from crystalline to amorphous can be reliably performed.

According to the fifth aspect of the present invention, when the main switch is turned off, the substance forming the phase transition layer can be automatically made to undergo a phase transition from crystalline to amorphous. It is possible to reuse the thermal energy generated when the phase transitions to crystalline.

According to the sixth aspect of the present invention, the substance forming the phase transition phase is kept at a temperature higher than room temperature and slightly lower than the crystallization start temperature while the image forming apparatus is in operation standby. Since it is maintained, the temperature of the fixing roller can be quickly raised to the fixing temperature by utilizing the thermal energy generated when the phase transition from amorphous to crystalline when the image forming apparatus is restarted. Therefore, waste of electric power and energy can be avoided.

According to the seventh aspect of the invention, when the image forming apparatus is in the preheating mode, even if the main switch is turned off, the phase transition work is not executed, so that wasteful consumption of electric power energy is wasted. Can be avoided.

According to the invention described in claim 8, the phase transition work can be executed only when a trouble related to the fixing power source occurs.

[0025]

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

FIG. 1 is a schematic view of a copying machine as an image forming apparatus. In FIG. 1, 1 is a device body, 2 is a panel for opening and closing the device body 1, 3 is a paper feed cassette, and 4 is a contact glass. 5, a toner bottle, 6 a fixing device,
Reference numeral 7 is an operation / display control unit, and 8 is a copy receiver. When the main switch SW is turned on, the main power source is turned on. A main switch SW shown in FIG. 2 is provided on the copy receiver 8 side of the apparatus body 1. The fixing device 6 is provided on the apparatus main body 1.
An image forming mechanism including is included. Paper cassette 3
The recording sheet 3a set on is sent to the fixing device 6 via the photoconductor and the transfer device, and the toner image formed on the photoconductor at that time is transferred to the recording sheet 3a by the transfer device.

The panel 2 is composed of a first panel 2a on the fixing device 6 side and a second panel 2b on the paper feed cassette side. The fixing device 6 has a pressure roller (not shown) and a fixing roller 9. The fixing roller 9 is brought into contact with the pressure roller and is rotated by the rotation of the pressure roller. The pressure roller has a well-known structure, and an elastic body such as rubber is attached to the outer circumference of a cored bar made of aluminum, iron or the like. The fixing roller 9 is a hollow cylindrical core metal 9 as shown in FIG.
a. As the material of the core metal 9a, a material having a good thermal conductivity, for example, an aluminum alloy is used. Core metal 9a
A phase transition layer 9b made of a substance capable of phase transition between crystalline and amorphous is provided on the outer peripheral surface of the. This substance is selected from elements belonging to groups IIIB to VIB of the periodic table (long period type), for example, chalcogen, chalcogenide compound, selenium, selenium-tellurium alloy, germanium-tellurium alloy, indium-selenium alloy, indium. -Selected from tellurium alloys, antimony-selenium alloys, antimony-tellurium alloys, etc. with a crystallization temperature of 8
Considering that a material in the range of 0 ° C. to 200 ° C. is preferable, the fixing temperature T is about 180 ° C., and it is preferable that heat is concentratedly generated during crystallization, selenium is particularly preferable. It is preferably a selenium-tellurium alloy. A protective layer 9c is formed on the outer periphery of the phase transition layer 9b. The protective layer 9c plays a role of preventing the substance constituting the phase change layer 9b from flowing out when the phase change layer 9b is in a molten state. The protective layer 9c may be made of a material that prevents the adhesion of the toner, or a release layer made of a fluororesin may be formed on the surface of the protective layer 9c to prevent the adhesion of the toner. Is also good. A cylindrical Peltier effect element 9d is arranged on the inner circumference of the cored bar 9a. Code 9
e and 9e are conductive wires for passing a current through the Peltier effect element 9d. The Peltier effect element 9d has a function of raising the outer peripheral surface of the fixing roller 9 to the fixing temperature T, a function of heating and melting the crystallized phase transition layer 9b, and then cooling the phase transition layer 9b. Also, it functions as an amorphization means for changing the phase from crystalline to amorphous again. Although the temperature of the fixing roller 9 is increased by using the Peltier effect element 9d here, the fixing roller 9
It is also possible to insert a halogen lamp in the hollow and heat the fixing roller 9 by utilizing the emitted radiant heat of the halogen lamp.

As shown in FIG. 2, a microprocessor CPU is provided in the apparatus main body 1. In addition to connecting a ROM memory to this microprocessor CPU, the operation / display controller 7, delay circuit, main switch SW, preheating mode switch SW, panel open / close switch SW, open / close prohibition via the input / output interface I / O. A means, a heating means, an amorphization means, a jam detection sensor, a toner remaining amount detection sensor, a waste toner full detection sensor, a cleaning blade dirt detection sensor and the like are connected. In this embodiment, the Peltier effect element 9d has heating means for causing the phase transition layer 9b to undergo a phase transition from amorphous to crystalline and amorphization for causing the phase transition layer 9b to undergo a phase transition from crystalline to amorphous. I / O interface I /
The connecting line to O is shared. Microprocessor C
The PU has a function of controlling various controls required for copying work, and a program for performing the control is written in the ROM memory. The preheating mode switch SW is provided near the main switch SW. The preheat mode switch SW has a role of prohibiting an operation command from the operation / display control unit 7 and forcibly causing the image forming apparatus to stand by in the preheat mode. The image forming apparatus is in the preheating mode when it is in the standby state after warming up and the operation / display control unit 7 does not issue an operation command for a predetermined time or more, or when the preheating mode switch SW is on.
The image forming apparatus maintains the fixing roller 9 at the preheating temperature T0 in the preheating mode. For example, when a selenium material is used for the phase transition layer 9b, the crystallization start temperature Tc from amorphous to crystalline is obtained.
Is about 120 degrees C, the preheating temperature T0 is set to about 100 degrees C. When the Peltier effect element 9d functions as a heating means from crystalline to amorphous, the phase transition layer 9b in the crystalline state is heated from the fixing temperature T to the melting point temperature Tm or higher and in the vicinity thereof. After once raising the temperature until the substance forming the phase transition layer 9b is in a molten state,
By reversing the direction of current flow to the Peltier effect element 9d, the substance forming the phase change layer 9b is rapidly cooled from the molten state to be amorphous. The melting point of selenium is about 2
It is 17 ° C.

The temperature control data is previously written in the ROM memory. The delay circuit operates when the main switch SW is turned off, for the purpose of amorphizing the substance forming the crystalline phase transition layer 9b. That is, when the temperature of the fixing roller 9 is the fixing temperature T, the substance forming the phase transition layer 9b is in a crystalline state,
When there is no delay circuit, power is not supplied to the Peltier effect element 9d when the main switch SW is turned off, and the phase transition layer 9b
Could not be made amorphous, and the main switch S
When W is turned on, the thermal energy generated when the substance forming the phase transition layer 9b undergoes the phase transition from amorphous to crystalline cannot be used for warming up. However, in the embodiment of the present invention, Even when the main switch SW is turned off, power is supplied during the phase transition from crystalline to amorphous, so that the substance forming the phase transition layer 9b undergoes phase transition from amorphous to crystalline. It is possible to reliably reuse the heat energy generated in the. The delay circuit may not be operated when the main switch SW is turned off while the fixing roller 9 is at the preheating temperature T0. This is because when the fixing roller 9 is at the preheating temperature T0, the substance forming the phase transition layer 9b is originally in an amorphous state. Further, the preheat mode switch SW is used when the image forming apparatus is warmed up.
Also, it is turned off when the fixing roller 9 is heated from the preheating temperature T0 to the fixing temperature T.

As shown in FIG. 4, the panel opening prohibiting means comprises a solenoid 10 and an iron plate 11.
The solenoid 10 is provided in the main body 1 of the apparatus, and the reference numeral 10a is an adsorption portion thereof. The iron plate 11 is provided on the panel 2a,
When the panel 2a is closed, it faces the suction portion 10a. Panel open / close detection switch S is provided on the apparatus main body 1.
Pressure sensors 12, 12 'as W are provided.
The microprocessor CPU has its pressure sensors 12, 12
It is detected whether or not the panels 2a and 2b are opened based on the change of the signal of '. Note that, as shown in FIG. 5, the panel opening prohibiting means may be composed of the motor 13, the hook-shaped member 14, and the U-shaped hook 15. The panel 2a is provided with an auxiliary iron plate (not shown), and the apparatus body 1 is provided with an auxiliary permanent magnet (not shown) corresponding to the auxiliary iron plate. 2a does not open carelessly. On the other hand, the panel 2b is provided with an auxiliary iron plate 11 ', and the apparatus main body 1 is provided with an auxiliary permanent magnet 10' corresponding to the auxiliary iron plate 11 '.

The operation / display controller 7 is a liquid crystal display panel 7a.
Having. The liquid crystal display panel 7a is configured, for example, as shown in FIG. An operator such as a copy worker or a service person performs a work according to the display command based on the display on the liquid crystal display panel 7a, and when jamming, toner replenishment (toner bottle replacement), etc. are required, that effect is given. Is displayed, and when the waste toner is full, the cleaning blade is dirty, etc., a message (for example, the tool mark 7b) indicating that the repair worker is contacted is displayed.

Next, an embodiment of the present invention will be described according to a flow chart.

FIG. 7 is a flow chart for explaining the operation of the embodiment of the image forming apparatus according to the present invention. FIG.
When the main switch SW is turned on as shown in (S.
1), the microprocessor CPU is the liquid crystal display panel 7a
A warming-up display command and an opening prohibition command for the panel 2a are output (S.2), and energization of the Peltier effect element 9d is started. As a result, the Peltier effect element 9d starts heating the phase transition layer 9b (S.3),
When the substance forming the phase transition layer 9b exceeds the crystallization start temperature Tc in the process of raising the temperature, the phase transition layer 9b undergoes a phase transition from amorphous to crystalline. The microprocessor CPU detects the fixing lower limit temperature TL by a temperature sensor (not shown), and determines whether the temperature is equal to or lower than the fixing lower limit temperature TL (S.4). When the temperature is below the fixing lower limit temperature TL, S.I. 3 and the phase change layer 9
Heating to b is continued. Due to the thermal energy generated during the phase transition from amorphous to crystalline, the fixing roller 9
Is rapidly raised to the fixing temperature T. As a result, the warm-up is executed quickly. In FIG. 11, reference numeral Q1 indicates the temperature rising process during this warming up. When the microprocessor CPU is at the fixing lower limit temperature TL or higher, the S.C. Then, the process proceeds to step 5 to release the prohibition of opening of the panel 2a. At that time, a display indicating that the panel 2a can be opened is displayed. That is, the power supply to the solenoid 10 is cut off, and the panel 2a can be opened. Next, the microprocessor CPU determines whether or not the main switch SW is off (S.6), and when the main switch SW is on, the S.S. Move to 7. When the warm-up is completed, the microprocessor CPU outputs a display command to the liquid crystal display panel 7a to the effect that "copying is possible". The operator normally performs a copying operation in this state, and in FIG.
Indicates a state in which the fixing roller 9 is maintained at the fixing temperature T.

S. 7, the microprocessor C
The PU determines whether there is an inspection work request command such as occurrence of a jam or replacement of a toner bottle. If there is no inspection work request command, S. Then, the process proceeds to step 8 to determine whether the operation / display control unit 7 has not been operated for a predetermined time. When the operation / display controller 7 is operated within a predetermined time, it is determined whether the preheating mode switch SW is on (S.
9). When the preheating mode switch SW is off, the S. 4, the detection of the fixing lower limit temperature TL is continued, and S. 4 ~
S. Step 9 is repeated. S. 7, when there is an inspection request work command, S.S. The process shifts to 10 and it is determined whether the inspection work request is bottle replacement. When the inspection work request is to replace the bottle, the operator opens the panel 2b to perform the bottle replacement process (S.11). Then, the microprocessor CPU determines whether or not the panel 2b is closed (S.12), and when the panel 2b is closed, S4
Move to When the inspection work request is not bottle replacement,
The microprocessor CPU is an S.M. Go to step 13. S.
In 13, after prohibiting the opening of the panel 2a (including the display indicating that the panel cannot be opened), the process proceeds to S14. S. In 14, the Peltier effect element 9d heats the substance forming the phase transition layer 9b and raises it to a temperature not lower than the melting point Tm to melt it. Then, the substance forming the phase transition layer 9b is melted. It is determined whether or not (S.15).
This determination is made by a temperature sensor (not shown) based on whether or not the temperature of the fixing roller 9 exceeds the melting point Tm. In FIG. 11, reference numeral Q3 indicates this state. Then the microprocessor CPU In 16, the panel 2a
After the opening prohibition is released (including a display indicating that the panel 2a can be opened), the direction of energization to the Peltier effect element 9d is reversed to rapidly cool the substance forming the phase transition layer 9b (S. 17). Then, it is determined whether or not the temperature of the fixing roller 9 is equal to or lower than the crystallization temperature Tc (S.18). When the temperature becomes equal to or lower than the crystallization temperature Tc, the cooling based on the Peltier effect element 9d is stopped. Next, the microprocessor CPU displays the specific contents of the inspection request work on the liquid crystal display panel 7a (S.19), and then sets the counter value N (not shown) to 0 (S.20). It should be noted that the release prohibition of the panel 2a is released in step S. 18 and Step S. Step S.19. You may go at 16 '. The operator opens either the panel 2a or the panel 2b, and performs the work based on the inspection request work content displayed on the display panel 7a (S.21). Panel 2a
The fixing power supply is turned off at the time of opening.

When the panel 2a is opened, the output of the pressure sensor 12 changes from on to off. When the panel 2a is closed after the work based on the work request command is completed, the pressure sensor 12 is turned from off to on, and the microprocessor CPU
Detects whether the pressure sensor 12 is turned on (S.
22). S. After detecting the closing of the panel 2a in S22, S
23, and it is determined whether the inspection request work command continues. If no inspection request work command is issued,
S. Move to 2. Therefore, the fixing roller 9 is quickly heated to the fixing temperature T by the heat energy generated when the substance forming the phase transition layer 9b is heated and the phase transitions from the amorphous state to the crystalline state.

S. 23, when the inspection request work command is issued, "+1" is added to the count value N of the counter (S.24), and then it is determined whether the count value N is larger than the predetermined value M or not. (S.25), when the count value N is smaller than the predetermined value M, S.S. 19, the inspection work request is continuously displayed, the contents of the count value N are sequentially added in accordance with the opening / closing operation of the panel 2a, and the inspection request work is performed even if the number N of times of opening / closing of the panel exceeds the predetermined value M. If the inspection work request command continues to be displayed due to some abnormality (for example, jam processing), it is necessary to stop the copying work and request a service person. Is displayed (S.26).

Next, S. 6, the main switch SW
Is turned off, the delay circuit is activated (S.27).
After that, it is determined whether or not the preheating mode is set (S.2).
8). In the preheating mode, the processing is completed as it is. In the preheating mode, the opening of the panel 2a is prohibited (S.29), and power is being supplied in order to change the substance forming the phase transition layer 9b from crystalline to amorphous. Is displayed (S.30). Then, the Peltier effect element 9d heats and melts the substance forming the phase transition layer 9b (S.31), and then determines whether the temperature of the substance forming the phase transition layer 9b is equal to or higher than the melting point Tm. Is judged (S.3
2) When the temperature of the substance forming the phase change layer 9b is equal to or higher than the melting point Tm, the opening inhibition of the panel 2a is released (S.33), and then the cooling treatment for forming the phase change layer 9b is performed. It is executed (S.34). Next, the phase transition layer 9b
It is judged whether or not the amorphization of the substance forming the is completed (S.35), and then the operation of the delay circuit is stopped (S.36), and then the process is ended. It should be noted that the execution of the opening prohibition cancellation of the panel 2a is performed in step S. 35
And step S. 36 between steps S.36. 33 'may be executed.

Next, the S. 9, when the preheating mode switch SW is on, it is determined whether or not a predetermined time has elapsed since the preheating mode switch SW was turned on (S.3).
7), then S. Move to 38. This is because it may be desirable to turn off the preheat mode switch SW and then immediately turn off the preheat mode switch SW to perform a copying operation. When the operation / display control unit 7 has not been operated for a predetermined time, the S.S. Move to 38. S. In 38,
The opening prohibition process of the panel 2a is executed, then the display indicating that the phase transition work is in progress (S.39), and thereafter, heating / melting for amorphizing the substance forming the phase transition layer 9b is executed. (S.40), it is determined whether the temperature of the phase change layer 9b is equal to or higher than the melting point Tm (S.41). From this, it is judged whether or not the heating / melting process is completed.
In the course of the melting process, it is judged whether or not the preheating mode switch SW is turned off (S.42). When the preheating mode switch SW is turned off, the S.S. Panel 2 moved to 43
After performing the opening prohibition cancellation of S.a. Move to 4. In this case, in order to prohibit the copying operation when the substance forming the phase transition layer 9b is in a molten state, it is desirable to wait for a predetermined time to execute the copy prohibition cancellation.
S. 41, when the temperature of the substance forming the phase transition layer 9b is equal to or higher than the melting point Tm, S.S. Moving to 44, panel 2
The opening prohibition process of a is executed. After this, S. At 45, the substance forming the phase transition layer 9b in the molten state is cooled, and then it is determined whether the temperature of the substance forming the phase transition layer 9b is equal to or lower than the crystallization start temperature Tc. (S.46). During the cooling for amorphizing the substance forming the phase transition layer 9b, it is determined whether the preheating mode switch SW is turned off (S.47), and when the preheating mode switch SW is turned off, The prohibition of opening the panel 2a is released (S.48), and then the process proceeds to S4. In addition,
In this case as well, in order to prohibit the copying operation when the substance forming the phase change layer 9b is in a molten state, it is desirable to wait for a predetermined time to execute the copying prohibition cancellation.

When the preheating mode switch SW is turned off during the phase transition work of turning on the preheating mode switch SW to amorphize the material forming the phase transition layer 9b, the phase transition layer 9b is turned off. The amorphous state and crystalline state of the constituent substances may coexist, but this does not affect the energy utilization efficiency.

Next, the S. 46, when the temperature of the substance forming the phase transition layer 9b is equal to or lower than the crystallization start temperature Tc, the completion of the phase transition work is displayed (S.49), and S.49. Then, the process proceeds to 50 and it is determined whether the preheating temperature T0 or lower. When the temperature of the substance forming the phase transition layer 9b is equal to or lower than the preheating temperature T0, the Peltier effect element 9d is energized to maintain the temperature of the fixing roller 9 at the preheating temperature T0 (S.51), and then the preheating mode is set. Whether the switch SW is off (S.
52), it is determined whether the operation / display control unit 7 has not been operated for a predetermined time (S.53), and when the preheating mode is released, S.52. Move to 2. In FIG. 11, reference numeral Q4 indicates the cooling process in the preheating mode and the state of maintaining the preheating temperature T0. It should be noted that the execution of the opening prohibition cancellation of the panel 2a is performed in step S. 46 and step S.6. 49 between steps S.49. You may go at 44 '.

Here, the Peltier effect element 9d is used to heat, melt, and cool the phase transition layer 9b. A known halogen lamp is used for heating and melting the phase transition layer 9b. A blower fan may be used to cool the phase transition layer 9b. Further, in this case, it is considered that the power plug is directly pulled out from the outlet of the indoor wiring, so that it is desirable that the power supply circuit has a built-in battery.

Further, although the panel 2 is described as a two-divided panel here, the present invention can be applied to a panel having one sheet.

Furthermore, in this embodiment, since the phase transition work of the substance constituting the phase transition layer from crystalline to amorphous is performed,
Although the cooling from the molten state is performed by energizing the Peltier effect element 9d, it can also be performed by natural cooling by appropriately selecting the substance forming the phase transition layer.

[0044]

Since the invention described in claims 1 to 8 is configured as described above, it is possible to stably perform the phase transition work without sacrificing the opening and closing operability of the panel as much as possible. Has the effect.

[Brief description of the drawings]

FIG. 1 is a diagram showing an external configuration of an image forming apparatus according to the present invention.

FIG. 2 is a control block diagram of the image forming apparatus according to the present invention.

FIG. 3 is a sectional view showing an example of a fixing roller according to the present invention.

FIG. 4 is a cross-sectional view showing an example of panel opening prohibition means according to the present invention.

FIG. 5 is a cross-sectional view showing another example of the panel opening prohibiting means according to the present invention.

6 is a plan view showing an example of an operation / display control section shown in FIG. 1. FIG.

FIG. 7 is a flowchart for explaining the operation of the image forming apparatus according to the present invention.

FIG. 8 is a flowchart for explaining the operation of the image forming apparatus according to the present invention.

FIG. 9 is a flowchart for explaining the operation of the image forming apparatus according to the present invention.

FIG. 10 is a flowchart for explaining the operation of the image forming apparatus according to the present invention.

FIG. 11 is a temperature change graph showing an example of the temperature rising process, the fixing temperature maintaining process, and the melting / cooling process of the phase transition layer when the fixing device according to the present invention is started up.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Housing 2 ... Panel 6 ... Fixing device 9 ... Fixing roller 9b ... Phase transition layer 10 ... Solenoid (Panel opening prohibition means) 11 ... Iron plate (Panel opening prohibition means)

Claims (8)

[Claims] 1. An image forming mechanism including a fixing device is provided in a housing having an openable / closable panel, and the fixing device is capable of phase transition between a crystalline state and an amorphous state on an outer peripheral surface of a fixing roller. In an image forming apparatus in which a phase transition layer made of a different substance is provided, and the fixing roller accelerates the temperature rise of its outer peripheral surface by thermal energy generated at the time of phase transition from amorphous to crystalline by heating, A panel opening inhibiting means for inhibiting the opening of the panel, wherein the panel opening inhibiting means inhibits the opening of the panel during a phase transition operation between the crystalline and amorphous phases of the phase transition layer; A characteristic image forming apparatus. 2. The image forming apparatus according to claim 1, wherein the phase change operation is heating operation of the phase change layer from amorphous to crystalline. 3. The image forming apparatus according to claim 1, wherein the phase change operation is a heating / melting operation from crystalline to amorphous of the phase change layer. 4. The image forming apparatus according to claim 1, wherein the phase transition work includes heating / melting work from crystalline to amorphous of the phase change layer and cooling work after melting. 5. The image forming apparatus according to claim 1, wherein the phase transition work is performed when a main switch is turned off. 6. The phase transition operation is performed at the start of a preheating mode for maintaining the temperature of the phase transition layer at a preheating temperature higher than room temperature and slightly lower than the amorphization temperature of the phase transition layer. The image forming apparatus according to claim 5, further comprising: 7. The execution of the phase change operation is prohibited if the main switch is turned off while the phase change layer is maintained at a preheating temperature.
An image forming apparatus according to claim 1. 8. The image forming apparatus according to claim 1, wherein the panel includes a first panel and a second panel facing the fixing device.