JPH11272149A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device capable of performing dehumidification and prevention of dew condensation with less power consumption. SOLUTION: This image forming device is provided with a dehumidifying heater 2 dehumidifying the transfer material inside a paper supplying tray, a dew condensation preventing heater 40 for preventing the dew condensation against the optical element of an optical system reading and writing image information, and a control means for controlling energization of the heaters 2 and 40; and the control means has a feature that it performs the energizing control of the heater 2 independently of the energizing control of the heater 40.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electrophotographic copying machine,
It relates to image forming apparatuses such as laser printers and facsimile machines, and in particular, has the function of dehumidifying the transfer material in the paper feed tray and the function of preventing condensation on lenses and mirrors in the system that reads and writes image information. The present invention relates to an image forming apparatus having the same.

[0002]

2. Description of the Related Art Conventionally, an image having a dehumidifying function for dehumidifying a transfer material (paper) in a paper feed tray and a dew condensation preventing function for preventing dew condensation on a lens and a mirror in a system for reading and writing image information. In the forming apparatus, dehumidification of a transfer material and prevention of dew condensation on a lens and the like are performed by various methods. For example, in Japanese Patent Application Laid-Open No. 4-94337, a humidity sensor is installed at a position immediately adjacent to a transfer material in a paper feed tray, and power to a dehumidification heater is turned on and off based on humidity information from the humidity sensor. Thereby, the humidity of the transfer material is controlled. In addition,
In Japanese Patent No. 74341, power is supplied to the dehumidifying heater only when power is not supplied to the fixing device, and the humidity of the transfer material is controlled. In an image forming apparatus having both the dehumidification function and the dew condensation prevention function, dehumidification and dew condensation prevention are performed under common control conditions. For example, in Japanese Patent Application Laid-Open No. 9-269706, when the power of the image forming apparatus main body is turned off, power is always supplied to the dew condensation prevention heater and the dehumidification heater. That is, electric power is supplied to the dew condensation prevention heater and the dehumidification heater under the common condition that the power is turned off.

[0003]

However, Japanese Patent Application Laid-Open No. 4-9 / 1990
In the method of performing dehumidification using a humidity sensor as disclosed in Japanese Patent No. 4337, dehumidification or the like may adhere to the humidity sensor, and normal dehumidification control may not be performed. In addition, since the humidity sensor is expensive, there is a problem that the manufacturing cost of the entire apparatus increases.

Further, the dehumidifying heater is energized only when power is not supplied to the fixing device as disclosed in Japanese Utility Model Laid-Open No. 1-74341, or the dew condensation preventing heater is always turned off when the power is turned off as disclosed in Japanese Patent Application Laid-Open No. 9-269706. In the configuration in which the dehumidifying heater is energized, the heater is energized immediately after image formation even when the temperature in the image forming apparatus is high, so that the temperature in the image forming apparatus becomes unnecessarily high. In addition, as disclosed in Japanese Patent Application Laid-Open No. 9-269706, dehumidification (since the transfer material absorbs moisture depending on the humidity of the atmosphere irrespective of the season, the relative humidity must be lowered by increasing the temperature or the like) and dew condensation (seasonal) Phenomena having different properties, such as a large change in temperature, are controlled under common conditions, that is, when the power is turned off, power is supplied to both the dew condensation prevention heater and the dehumidification heater (the power is turned off). Therefore, in a configuration in which both functions of dehumidification and dew condensation prevention work, the power consumption becomes extremely large.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an image forming apparatus capable of performing dehumidification and preventing dew condensation with low power consumption.

[0006]

In order to solve the above-mentioned problems, the invention according to the first aspect of the present invention provides a dehumidifying heater for dehumidifying a transfer material in a sheet feeding tray and an optical device for reading and writing image information. In an image forming apparatus having both a dew condensation preventing heater for preventing dew condensation in a system and a control unit for controlling energization to the dehumidifying heater and the dew condensation preventing heater, the control unit includes a dehumidifying heater for controlling energization and preventing dew condensation. It is characterized in that the control of the energization of the heater is performed independently.

According to the first aspect of the present invention, the energization control of the dehumidifying heater and the dew condensation preventing heater is not performed under a common control condition as in the related art, but separately under different conditions. Since control is performed, fine control is possible. In addition, by controlling independently,
Since control is performed only for heaters that require energization control, energy can be saved.

[0008] The invention described in claim 2 is the first invention.
In the invention described in the above, comprising a temperature detecting means for detecting the temperature of the members involved in image formation, and a timer for detecting a set time and inputting the detection information to the control means,
The control means controls energization to the dehumidification heater based on temperature information from the temperature detection means and controls energization to the dew condensation prevention heater based on detection information from the timer.

According to the second aspect of the present invention, the power supply to the dehumidification heater is controlled by the information from the temperature detecting means, and the power supply to the dew condensation preventing heater is controlled by the information from the timer. Fine control becomes possible. In addition, since control is performed only for heaters that require energization control, energy can be saved.

[0010] Further, the invention described in claim 3 is based on claim 2.
Wherein the temperature detecting means comprises a temperature detecting element for detecting a temperature of a fixing device for fixing the toner image transferred to the transfer material, and the control means comprises a fixing device for detecting the temperature detected by the temperature detecting element. When the temperature of the apparatus falls below a predetermined temperature, power is supplied to the dehumidification heater.

According to the third aspect of the present invention, the transfer material can be dehumidified without requiring a new sensor, and energy and cost can be saved. This also prevents an excessive temperature rise in the device.

The invention described in claim 4 is the same as the claim 2.
In the invention described in the above, the temperature detecting means comprises a temperature detecting element for detecting a temperature of the image carrier which carries image information, and the control means comprises means for controlling the temperature of the image carrier detected by the temperature detecting element. When the temperature falls below a predetermined temperature, power is supplied to the dehumidification heater.

According to the fourth aspect of the present invention, it is possible to control the dehumidification of the transfer material without requiring a new sensor, and to save energy and cost. This also prevents an excessive temperature rise in the device.

The invention described in claim 5 is the same as the claim 2.
In the invention described in the above, the timer has a weekly timer function capable of changing the state of the image forming operation according to the arrival of a set day of the week and time, and the control unit performs image forming based on a signal from the timer. The power supply to the dew condensation prevention heater is performed a predetermined time before the power supply for enabling the power supply is turned on.

According to the fifth aspect of the present invention, since the heater for dew condensation prevention is energized only when it is desired to prevent dew condensation, dew condensation can be efficiently prevented and the energy saving effect is large.

The invention described in claim 6 is the same as the invention described in claim 2.
In the invention described in (1), an operation unit is provided which is electrically connected to the timer and sets an energization start time to the dew condensation prevention heater.

According to the invention described in claim 6, it is possible to set an optimum energization time of the dew condensation prevention heater according to the installation environment, and it is possible to further save energy.

The invention described in claim 7 is the same as the invention described in claim 2.
The control means has a control mode for controlling energization to the dehumidification heater and the dew condensation prevention heater based on temperature information from the temperature detection means, and an operation unit for setting the control mode. It is characterized by having.

According to the seventh aspect of the present invention, it is possible to maximize the effect of preventing dew condensation even when the device is used in a place where the installation environment is very bad and dew condensation is likely to occur. Become.

The invention described in claim 8 is the second invention.
Alternatively, in the invention according to claim 7, the control means has a control mode for controlling energization to the dehumidification heater and the dew condensation prevention heater based on detection information from the timer, and an operation for setting the control mode. It is characterized by having a part.

According to the eighth aspect of the present invention, the optimal energizing time of the dehumidifying heater can be set according to the installation environment, so that greater energy savings can be achieved.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a schematic configuration of a copying machine as an image forming apparatus according to the present embodiment. As shown, the copying machine includes a reading optical system 21 for reading an original image on a platen glass and a photosensitive drum 6 as an image carrier.
And a writing optical system 27 for writing image information to the optical disk.

The reading optical system 21 includes a light source 22 for irradiating the original with light, and a condensing lens 2 for reflecting light reflected from the original.
The mirror group 24 includes a mirror group 24 for guiding the light to the light source 3, a reading element 25 for reading the collected reflected light, and a fan 26 for releasing heat generated from the light source 22 to the outside.

The writing optical system 27 has a polygon mirror 28, a lens group 29, and a mirror 30, and reflects light from a light emitting source (not shown) by the polygon mirror 28 set so as to match the timing. The light is condensed by the lens group 29, reflected by the mirror 30 in a predetermined direction, and guided to the surface of the photosensitive drum 6 already charged by the charging charger 31. As a result, an electrostatic latent image corresponding to the document image (read image) is formed on the photosensitive drum 6. This electrostatic latent image is visualized by toner carried by the developing roller 32.

On the other hand, the transfer material (paper) stored in one or a plurality of paper feed trays 1 (two paper feed trays 1a and 1b are shown in the figure) is called a call roller 9 (in the figure). Are fed to a predetermined position of the photosensitive drum 6 by two feeding rollers 9a and 9b corresponding to the two sheet feeding trays 1a and 1b) and the sheet feeding roller 33.
The fed transfer material is sent to the transfer unit by a registration roller at a predetermined timing (in synchronization with the rotation of the photosensitive drum 6 (in the direction of the arrow)). In the transfer section, the toner image on the photosensitive drum 6 is transferred to a transfer material by the transfer charger 34. Thereafter, the transfer material to which the toner image has been transferred is discharged by the separation charger 35 and then separated from the photosensitive drum 6, and is fixed to the fixing roller 5a.
The toner image is heat-fixed by a fixing device 5 composed of a pressure roller 5b and a pressure roller 5b, and is conveyed to a discharge tray (not shown) by a discharge roller 38.

After the toner image is transferred onto the transfer material, the toner remaining on the surface of the photosensitive drum 6 is removed by the cleaning unit 36 in order to prepare for the formation of the next electrostatic latent image. In the figure, reference numeral 37 denotes an exhaust fan, which exhausts heat from the entire apparatus.

Further, in the copying machine of the present embodiment, the dew condensation preventing heater 40 is provided in the reading optical system 21. The dew condensation prevention heater 40 prevents dew condensation on the lenses and mirrors of the reading optical system 21 and the writing optical system 27.
That is, in the present embodiment, one heater 40 prevents both the reading optical system 21 and the writing optical system 27 from dew condensation.

Further, a dehumidifying heater 2 such as a sheath heater using a heating wire is provided in the sheet feeding tray 1.
(The dehumidification heater 2a is provided on the paper feeding tray 1a, and the dehumidification heater 2b is provided on the paper feeding tray 1b.) This dehumidification heater 2 is arranged at the bottom of the paper feed tray 1,
By warming the bottom of the paper feed tray 1, heat is diffused as a whole, and the transfer material is warmed and dehumidified. In the present embodiment, two paper feed trays 1 are provided, but the number of paper feed trays is not limited to this.

FIG. 2 is a block diagram of a circuit involved in controlling the energization of the dehumidifying heater 2 and the dew condensation preventing heater 40.
In the circuit shown, the main switch (POWER SW)
When the switch 46 is turned on, the first DC power supply 47 operates by the power from the power supply 45 input via the AC input plug, and power is supplied to each part of the control board 48. The control board 48 has a micro CPU 50 and a timer 49. The CPU 50 operates the first relay 52 that opens and closes a circuit that connects the second DC power supply 51 and the power supply 45,
The operation of the second relay 53 for opening and closing the circuit connecting the dehumidifying heater 2 and the power supply 45, the dew condensation prevention heater 40 and the power supply 4
5 and the operation of the third relay 54 that opens and closes the circuit connecting the circuit 5 and the control circuit 5.

The control board 48 includes a fixing roller temperature detecting element 4a for detecting the temperature of the fixing roller 5a of the fixing device 5, a drum temperature detecting element 4b for detecting the drum temperature of the photosensitive drum 6, and an operation unit. 44 are electrically connected.

FIG. 3 shows the fixing device 5. As shown, the fixing device 5 includes a fixing roller 5a and a fixing roller 5a.
a and a pressure roller 5b pressed against a. A flashing halogen lamp 5c is built in the fixing roller 5a. In order to maintain the temperature of the fixing roller 5a within a temperature range necessary for fixing, a fixing roller temperature detecting element 4a such as a thermistor is provided in contact with the surface of the fixing roller 5a. When the transfer material on which the toner image has been transferred is introduced into the nip portion between the fixing roller 5a and the pressing roller 5b, the toner image on the transfer material is changed by heat from the halogen lamp 5c provided on the fixing roller 5a. Be established.

When the main switch 46 is turned on, the inside of the image forming apparatus is close to the same state as the external environment.
The transfer material in the paper feed tray 1 is often in a high humidity state. Therefore, if an image is formed as it is, the electrostatic latent image on the photosensitive drum 6 is not transferred well, or wrinkles are generated on the transfer material heated and pressed rapidly by the fixing device 5. I do. In addition, a paper jam may occur due to a transfer material transfer failure, or a mirror or a lens may cause dew condensation, thereby making it impossible to read or write a normal image. However, when the temperature inside the image forming apparatus increases due to a heat source (for example, a heat source for preventing dew condensation on the fixing roller 5a, the light source 22, and the photosensitive drum 6), the transfer material in the sheet feeding tray 1 is increased. Is naturally dehumidified to a state where there is no problem in use.

The above-described problem that occurs when the main switch 46 is turned on may occur even in a normal use state. That is, even in a standby state in which the heat source of each unit is dropped to save power consumption, the temperature in the apparatus is low, so that the transfer material accommodated in the paper feed tray 1 is cooled and the humidity is high. The same applies to a case where a transfer material placed in an external environment is additionally used in the paper feed tray 1. Therefore, in the present embodiment, in order to solve the above problem, a dehumidifying heater is provided by a method described below. 2 and energization to the dew condensation prevention heater 40 are controlled.

First, the energization control of the dehumidification heater 2 will be described with reference to FIG. In the present embodiment, the CPU 5 detects the temperature based on the detection signal from the fixing roller temperature detecting element 4a.
When 0 activates the second relay 53, the energization to the dehumidification heater 2 is controlled. Specifically, the CPU 50
Activates the second relay 53 when it recognizes from the detection signal from the fixing roller temperature detecting element 4a that the temperature of the fixing roller 5a has not reached a predetermined temperature at which the transfer material can be sufficiently dehumidified. , Paper feed tray 1 (1
The power is supplied to the dehumidification heaters 2 (2a, 2b) of (a) and (1b). As a result, the dehumidifying heater 2 of the paper feed tray 1 is energized, and the transfer material in the paper feed tray 1 is dehumidified.

On the other hand, the CPU 50 determines that the temperature of the fixing roller 5a reaches a predetermined temperature at which the transfer material can be sufficiently dehumidified (the temperature of the fixing roller 5a rises, the inside of the apparatus is warmed, and When it is recognized that the transfer material in 1 has been dehumidified) by the detection signal from the fixing roller temperature detection element 4a, the second relay 53 is operated to stop the power supply to the dehumidification heater 2 (2a, 2b). . This prevents the temperature inside the device from becoming unnecessarily high and wasteful power consumption.

In this example, the CPU 50 controls the operation of the second relay 53 based on the detection signal from the fixing roller temperature detecting element 4a. CPU 4b based on a detection signal from a temperature detecting element for detecting the temperature inside the apparatus for controlling the operation of the exhaust fan 37 or 4b.
May control the operation of the second relay 53.

Next, control of energization of the dew condensation prevention heater 40 will be described. In the present embodiment, the CPU 50 operates the third relay 54 based on a signal from the timer 49 to control the power supply to the dew condensation prevention heater 40. In this case, the timer 49 also has a weekly timer function. This weekly timer function is, for example, a power supply 51 at 8:00 am every day from Monday to Friday.
Is set to the ON state (a state where the copying operation can be performed immediately) and the power supply 51 is turned off every day at 9:00 (a standby state in which a part of the power supply is energized. Specifically, the first relay 52)
Is turned off, all loads other than the control board 48 are turned off, and energy saving is achieved).
This function allows the user to freely set the day and time when the power supply 51 is turned on and off, such as setting the power supply 51 to the off state all day on Saturday and Sunday.

The operation unit 44 allows the user to set how long before the operable copy time (the time during which the power supply 51 is turned on) before turning on the dew condensation prevention heater 40. As a result, the user can freely select the optimal heater operation time from the conditions of the installation location of the machine, the local weather conditions, and the like. For example, the power supply 5
Assuming that the time at which 1 is set to the on state is set at 9:00 in the morning and the time at which the dew condensation prevention heater 40 is turned on is set two hours before that, the CPU 50 receives a signal from the timer 49 at 7:00 in the morning. Turn on the third relay 54,
The dew condensation prevention heater 40 is energized. Thereafter, at 9:00 in the morning after a lapse of time, the CPU 50 turns off the third relay 54 and turns on the first relay 52 in response to a signal from the timer 49 to start up the system. FIG. 4 is a flowchart showing an example of this operation.
The operation unit 44 turns on the dew condensation prevention heater 40 (the time when the dew condensation prevention heater ON time is subtracted from the system ON time).
Is set (S1), when the power supply 51 is turned off (when the first relay 52 is turned off), the CPU 50 sends a signal from the timer 49 to the set ON time of the dew condensation prevention heater 40. At the point of time (S2), the third relay 54 is turned on (S3), and the dew condensation prevention heater 40 is energized. Thereafter, when the time has elapsed and the arrival of the system ON time is transmitted to the CPU 50 through the timer 49 (S4), the CPU 50 causes the third relay 54
Is turned off and the first relay 52 is turned on to start up the system (S5).

Since the surface temperature of the fixing roller 5a is extremely high (about 200 degrees), a large amount of heat is dissipated from the fixing roller 5a into the apparatus. Therefore, in the present embodiment, when the power supply 51 is turned off by the weekly timer or in a standby state in which the copying operation is not performed for a long time, the halogen lamp 5c is completely turned off, or the halogen lamp 5c is turned on and off quickly. This is repeated, so that the temperature of the fixing roller 5a is kept low. Of course, even in this case, since the energization control of the dehumidification heater 2 and the dew condensation prevention heater 40 is performed as described above, an increase in the humidity of the transfer material and dew condensation on the lens and the like can be prevented.

Further, in the present embodiment, in consideration of use in a place where the installation environment is very bad and dew condensation is likely to occur,
The operation unit 44 can be set so that the energization control of the dew condensation prevention heater 40 is performed in the same manner as the energization control of the dehumidification heater 2. That is, this control mode is
Is set, the CPU 50 operates the third relay 54 based on the detection signal from the fixing roller temperature detection element 4a to control the energization to the dew condensation prevention heater 40 (of course,
The control of energization to the dehumidifying heater 2 is also performed based on the detection signal from the fixing roller temperature detecting element 4a as described above. In this control mode, power consumption increases,
This has the effect that dew condensation can be reliably prevented.

Further, in the present embodiment, the operation unit 44 can be set so that the energization control of the dehumidification heater 2 is performed in the same manner as the energization control of the dew condensation prevention heater 40. That is, when this control mode is set by the operation unit 44,
Based on the signal from the timer 49, the CPU 50 operates the second relay 53 to control the energization to the dehumidification heater 2 (of course, the energization control to the dew condensation prevention heater 40 is also controlled by the signal from the timer 49 as described above. Based on that). This control mode is excellent in that energy can be saved, and is particularly useful in an installation environment where little consideration is required for dehumidification and dew condensation.

FIG. 5 is a flowchart showing an example of the power-on control of the dehumidifying heater 2 when the power supply 51 is turned off by the weekly timer. When the power supply 51 is turned off by the weekly timer (S1), as long as the transfer material is present in the paper feed tray 1 (S2), the paper feed tray 1 is lowered by the tray movable means 7 (see FIG. 1). The transfer material is separated from the call roller 9 (S3). Further, as long as the power supply 51 is disconnected by the weekly timer (S4), the output of the temperature detecting element 4a for detecting the temperature of the fixing roller 5a is taken into the control board 48, and waits until the temperature becomes lower than a predetermined temperature. (S5), the dehumidification heater 2 is energized to start dehumidification of the transfer material in the sheet feeding tray 1 (S6). When the temperature of the temperature detecting element 4 reaches or exceeds a predetermined temperature (S7), it is determined that the temperature in the apparatus is sufficiently high and the dehumidification of the transfer material is naturally performed, and the temperature in the apparatus is further wasted. The dehumidifying heater 2 is turned off so as not to raise (S8). The blinking of the dehumidifying heater 2 continues as long as the power supply 51 of the weekly timer is not released (S4).

As described above, according to the copying machine (image forming apparatus) of the present embodiment, the dehumidification control of the transfer material and the dew condensation prevention control of the mirrors and lenses of the reading optical system 21 and the writing optical system 27 are performed. Are performed independently, so that fine control and energy saving can be achieved.

In this embodiment, the halogen lamp 5
The CPU 50 operates the second relay 53 based on a detection signal from the fixing roller temperature detection element 4a, which is an existing sensor necessary for the energization control of c, whereby the energization to the dehumidification heater 2 is controlled. That is, the internal temperature of the apparatus is assumed using the fixing roller temperature detecting element 4a (the internal temperature of the apparatus is assumed based on the temperature of the fixing roller 5a), thereby controlling the energization to the dehumidifying heater 2. Therefore, dehumidification control of the transfer material can be performed without requiring a new sensor, and energy saving and cost saving can be achieved. This also prevents an excessive temperature rise in the device. The same applies to the case where a drum temperature detecting element 4b for detecting the drum temperature of the photosensitive drum 6 or another existing temperature sensor is used instead of the fixing roller temperature detecting element 4a.

In this embodiment, the CPU 50 operates the third relay 54 based on a signal from the timer 49 to control the power supply to the dew condensation prevention heater 40. Specifically, the timer 49 has a weekly timer function that can change the operation state of the image forming apparatus according to the arrival of the set time, and the dew condensation prevention heater 40 is provided a predetermined time before the set time when the power supply 51 is turned on by the weekly timer. Is turned on to prevent condensation on the lenses and mirrors of the reading optical system 21 and the writing optical system 27. Therefore, dew condensation can be efficiently prevented, and the energy saving effect is large. Further, in the present embodiment, the operation time of the dew condensation prevention heater 40 (how long before the set time when the power supply 51 is turned on, how long the dew condensation prevention heater 40 should be energized) can be set by the operation unit 44. Therefore, it is possible to set the optimal energization time of the dew condensation prevention heater 40 according to the installation environment, and it is possible to save more energy.

In this embodiment, the dew condensation preventing heater 4
The operation unit 44 controls the energization control of the dehumidification heater 2 to be performed in the same manner as the energization control of the dehumidification heater 2 regardless of the weekly timer.
It can be set with. Therefore, even when the device is used in a place where the installation environment is extremely bad and dew condensation is likely to occur, the effect of preventing dew condensation can be maximized.

Further, in the present embodiment, the operation unit 44 can be set so that the energization control of the dehumidification heater 2 is performed in the same manner as the energization control of the dew condensation prevention heater 40. Therefore, the optimal energizing time of the heater 2 can be set according to the installation environment, so that greater energy saving can be achieved.

In this embodiment, a copying machine has been described as an example of an image forming apparatus. However, the above-described control method (dehumidification control and dew condensation prevention control) can be applied to other image forming apparatuses such as a laser printer and a facsimile. Needless to say, it can be applied. Although the copying machine of the present embodiment has the reading optical system 21 and the writing optical system 27, an apparatus without the reading optical system 21, such as a laser printer, has an image from an external device (not shown). The writing optical system 27 is operated according to the formation information, and the above-described image formation is performed.

[0050]

According to the first aspect of the present invention, since the energization control of the dehumidification heater and the dew condensation prevention heater is performed independently of each other, fine control and energy saving can be achieved.

According to the second aspect of the present invention, the power supply to the dehumidifying heater is controlled by the information from the temperature detecting means, and the power supply to the dew condensation preventing heater is controlled by the information from the timer. Control and energy saving become possible.

According to the third aspect of the present invention, it is possible to control the dehumidification of the transfer material without requiring a new sensor, thereby achieving energy saving and cost saving. This also prevents an excessive temperature rise in the device.

According to the fourth aspect of the present invention, it is possible to control the dehumidification of the transfer material without requiring a new sensor, and to save energy and cost. This also prevents an excessive temperature rise in the device.

According to the fifth aspect of the invention, dew condensation can be efficiently prevented, and the energy saving effect is large.

According to the sixth aspect of the present invention, it is possible to set an optimum energizing time of the dew condensation preventing heater according to the installation environment, thereby enabling greater energy saving.

According to the seventh aspect of the invention, even when the device is used in a place where the installation environment is very bad and dew condensation is likely to occur, the effect of preventing dew condensation can be maximized. .

According to the eighth aspect of the invention, the optimal energizing time of the dehumidifying heater can be set according to the installation environment, so that greater energy savings can be achieved.

[Brief description of the drawings]

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

FIG. 2 is a block diagram of a circuit involved in controlling energization of a dehumidification heater and a dew condensation prevention heater.

FIG. 3 is a perspective view of a fixing device.

FIG. 4 is a flowchart illustrating an example of operation control of a condensation prevention heater.

FIG. 5 is a flowchart showing an example of a power supply control of a dehumidification heater in a power-off state by a weekly timer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Paper feed tray 2 ... Dehumidification heater 40 ... Dew condensation prevention heater 44 ... Operation part

Claims (8)

[Claims] 1. A dehumidifying heater for dehumidifying a transfer material in a sheet feeding tray, a dew condensation preventing heater for preventing dew condensation of an optical system for reading and writing image information, and a dehumidifying heater and a dew condensation preventing heater. An image forming apparatus having a control unit for controlling energization, wherein the control unit performs energization control of a dehumidification heater and energization control of a dew condensation prevention heater independently. 2. A temperature detecting means for detecting a temperature of a member involved in image formation, and a timer for detecting a set time and inputting the detection information to the control means, wherein the control means is configured to detect the temperature. 2. The image forming apparatus according to claim 1, wherein the controller controls the energization of the dehumidifying heater based on temperature information from the means, and controls the energization of the dew condensation preventing heater based on detection information from the timer. apparatus. 3. The fixing device according to claim 1, wherein the temperature detecting unit includes a temperature detecting element that detects a temperature of a fixing device that fixes the toner image transferred to the transfer material. The control unit detects the temperature of the fixing device. 3. The image forming apparatus according to claim 2, wherein when the temperature of the image forming device becomes equal to or lower than a predetermined temperature, power is supplied to the dehumidifying heater. 4. The temperature detecting means comprises a temperature detecting element for detecting a temperature of an image carrier for carrying image information, and the control means controls a temperature of the image carrier detected by the temperature detecting element to a predetermined value. 3. The image forming apparatus according to claim 2, wherein when the temperature becomes equal to or lower than the temperature, the dehumidifying heater is energized. 5. The timer has a weekly timer function capable of changing the state of an image forming operation according to a set day of the week or the arrival of a time.
3. The image forming apparatus according to claim 2, wherein a power supply to the dew condensation prevention heater is performed a predetermined time before a power supply enabling image formation is turned on based on a signal from a timer. 6. The image forming apparatus according to claim 2, further comprising an operation unit electrically connected to the timer, for setting a time for starting energization of the dew condensation prevention heater. 7. The control means has a control mode for controlling energization to a dehumidification heater and a dew condensation prevention heater based on temperature information from the temperature detection means, and includes an operation unit for setting the control mode. The image forming apparatus according to claim 2, wherein: 8. The control means has a control mode for controlling energization to a dehumidification heater and a dew condensation prevention heater based on detection information from the timer, and includes an operation unit for setting the control mode. 3. The method according to claim 2, wherein
Alternatively, the image forming apparatus according to claim 7.