JP2006284618A - Dehumidification control apparatus for image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dehumidification control apparatus for an image forming apparatus dehumidifying in a state making efficient use of power even when a power switch is turned on. <P>SOLUTION: The dehumidification control apparatus for the image forming apparatus controls dehumidifying heaters which are installed in a plurality of positions in the apparatus and dehumidifying by heating specified parts. The dehumidifying control apparatus is composed from: first dehumidifying heaters 8 to which power is supplied when a power source switch 10 of the image forming apparatus is turned off and the supply of power is made from a first power supplying circuit A when the supply of power is shut off when the switch is turned on; second dehumidifying heaters 9 to which the supply of power is shut off when the power source switch 10 is turned off and the supply of power is made from a second power supplying circuit B which is controlled to supply power when the switch is turned on; and a control circuit C switching the second power supplying circuit B between a saving energy mode and a normal mode. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention includes an image forming unit that forms a toner image based on image data, a sheet feeding and conveying unit that supplies a sheet to which the formed toner image is transferred, and a heat that thermally fixes the image transferred to the sheet. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dehumidification control device for an image forming apparatus that controls a dehumidifying heater that is installed at a plurality of locations in the apparatus and dehumidifies by heating predetermined portions.

  In an image forming apparatus using an electrophotographic system such as a copying machine, the image may be distorted due to condensation of the main parts for image formation inside the machine, that is, a paper cassette, a photosensitive drum, etc. There are problems such as paper jams. As a countermeasure, a plurality of heaters are arranged in the main part, and a power supply line is provided to operate the heaters even at night when the power switch is turned off.

  On the other hand, the tendency to further promote energy saving is becoming more conspicuous due to environmental considerations, and the power supply to the heater of the heat fixing unit is cut off during standby when no image forming operation is performed, and an unnecessary load or such a load. It is also necessary to turn off the power source for driving.

Therefore, in order to eliminate the inconvenience of dehumidification when the power supply to the heater for which the power switch is turned on is cut off and then the mode is shifted to the power saving consumption mode in which the power supply to the heat fixing unit is stopped. Image forming by the image forming unit is possible. Heating and heat retaining means for heating a predetermined portion to retain heat to prevent dehumidification or condensation, switching means for switching between supply and interruption of power from a commercial power supply to the heat and heat retaining means In the mode, the switching unit is made to cut off the power supply from the commercial power supply unit to the heating and heating unit, and in the energy saving mode, the switching unit is supplied with power from the commercial power source unit to the heating and heating unit. There has been proposed one provided with a control means for controlling as described above.
JP 2003-84629 A

  However, in the above-described image forming apparatus, the dehumidifying heater is energized while the power switch is turned on except in the power saving mode, assuming that the temperature inside the apparatus rises to some extent due to the heat source of the heater of the heat fixing unit. However, depending on the device, even if the power switch is turned on, it may not be sufficiently dehumidified. Therefore, if the dehumidification control is performed at any time regardless of the power switch or the power saving consumption mode, the control device becomes complicated, which is contrary to the demand for power saving.

  An object of the present invention is to provide a dehumidification control device for an image forming apparatus that can control a dehumidification heater with high power use efficiency with a simple circuit configuration regardless of the power saving consumption mode and the state of a power switch.

  In order to achieve the above-mentioned object, the first characteristic configuration of the dehumidification control device of the image forming apparatus according to the present invention is that, as described in claim 1 of the claims, the toner image is generated based on the image information signal. An image forming apparatus comprising: an image forming unit to be formed; a paper feeding / conveying unit that supplies a sheet for transferring the formed toner image; and a heat fixing unit that thermally fixes the image transferred to the sheet. In the image forming apparatus, a dehumidification control device for controlling a dehumidifying heater that is installed at a plurality of locations in the apparatus and dehumidifies by heating a predetermined portion, wherein power is supplied when the power switch of the image forming apparatus is turned off, and power is supplied when turned on. A first dehumidifying heater that is fed by a first feeding circuit that is shut off, and a second dehumidifying power that is fed by a second feeding circuit that is fed when the power switch is turned off and is fed when the power switch is turned on. It comprises a chromatography data is the second power supply circuit to a point that is configured by providing a control circuit to switch the power saving consumption mode and the normal mode.

  According to the above-described configuration, the first power supply circuit and the second power supply circuit can perform dehumidification when the power switch is turned off, and the second power supply circuit can perform dehumidification when the power switch is turned on. In addition, when the power switch is turned on by the control circuit, the power feeding circuit is switched between the power saving consumption mode and the normal mode, so that appropriate dehumidification control can be performed according to each mode.

  According to the second characteristic configuration described in the second aspect, in addition to the first characteristic configuration described above, the second power feeding circuit includes the second dehumidifying heater based on an environmental state in the normal mode. Is controlled to a predetermined target temperature, and the second dehumidifying heater is switched to always supply power in the power saving consumption mode, whereby the power switch is turned on and in the normal mode not in the power saving consumption mode. Can be controlled to an appropriate temperature reflecting the influence of the heat source such as the heat fixing means, and in the power saving consumption mode in which the heater of the heat fixing means is turned off, the dehumidification is surely performed by always supplying power.

  The third characteristic configuration is a dehumidifying heater for a paper feeding cassette in which the first heater dehumidifies paper in addition to the first or second characteristic configuration described above, as described in claim 3. The second dehumidifying heater is a photosensitive member dehumidifying heater that dehumidifies the photosensitive drum of the image forming means. According to such a configuration, the peripheral area of the photosensitive member that has a significant influence on the image forming process during standby is provided. Temperature management can always be performed properly and reliable dehumidification can be performed when the power switch is turned off or in the power saving mode. One sheet is reliably dehumidified when the power switch is turned off or in the power-saving mode, and the internal temperature rises due to heat generated from the load such as the heater of the heat fixing means during standby. Will disappear.

  As described above, according to the present invention, it is possible to provide a dehumidification control device for an image forming apparatus that can perform dehumidification in a state where power use efficiency is good even when the power switch is on.

  A dehumidification control device for an image forming apparatus according to the present invention will be described below. As shown in FIG. 2, the image forming apparatus includes a document cover 1 that presses a document placed on a document placement table 1a, and an optical system that forms an image of a document placed on the document placement table 1a on an image sensor. 3, a paper feed cassette 2 in which paper is accommodated, an image forming unit 4 that forms a toner image based on image data read by the image sensor, and a paper that supplies paper for transferring the formed toner image The apparatus includes a paper transport unit 6 and a thermal fixing unit 5 that thermally fixes the image transferred onto the paper.

  The image forming unit 4 includes image forming units 4 a, 4 b, 4 c, and 4 d provided with a charger 41, a developing device 42, a cleaner 43, and the like along the rotation direction around the photosensitive drum 40 along the transfer belt 44. Each developing device contains toner of four colors, yellow, magenta, cyan, and black. An exposure optical path from the semiconductor laser unit is provided between the charging device 41 and the developing device 42, and the toner images developed in the respective colors are transferred to the transfer belt 44 and then transferred to the paper.

  The sheet on which the toner image has been transferred is sent to the thermal fixing means 5 by the paper feeding / conveying means 6, fixed, and then discharged to the paper discharge tray 7.

  Two AC power panel heaters serving as the first dehumidifying heater 8 are installed in the lower part of the paper feed cassette 4, and an AC power panel serving as the second dehumidifying heater 9 is provided inside each photosensitive drum 40. A heater is installed. The heater for dehumidification is not particularly limited, and any heater for AC power can be used as appropriate. Use of a DC power source heater is not preferable because it requires not only a DC power source that operates when the power switch, which will be described later, is turned off, but also inconveniences such as reduced conversion efficiency of the DC power source in the power saving mode. .

  The dehumidifying heaters 8 and 9 described above are heated and controlled by the dehumidifying control device according to the present invention, and dehumidifying the sheets of paper stored in the photosensitive drum 40 and the paper feed cassette 4 are controlled. As shown in FIG. 1, the dehumidifying control device includes a power switch 10 of a two-pole system that controls power supply from a commercial power supply 11 and a transformer that steps down the voltage of the commercial power supply when the power switch 10 is turned on. 12, a DC power source 13 that converts the stepped-down AC voltage into a control DC voltage, a main controller 14 that includes a CPU that operates with power supplied from the DC power source 13, and the DC voltage (VCC a transistor 18 that controls the supply of the sleep), and an engine controller 15 that includes a CPU that is operated by a DC power source that is supplied via the transistor 18. The main controller 14 controls the entire system including image processing, and the engine controller 15 controls the image forming process, and both cooperate to control the image forming apparatus through serial communication or the like.

  Although the configuration of the power switch 10 will not be described in detail, a DC power source generated when the control contact of the power switch 10 is turned on (even if the above-described DC power source is used) A known relay circuit for connecting an AC contact by power feeding from the power supply is provided. When the power switch 10 is turned off, power is supplied to the dehumidifying heaters 8 and 9 from the commercial power source for dehumidification, and the dehumidifying heaters 8 and 9 are saturated at a predetermined temperature when always energized. Is set to When the power switch 10 is turned off, the power supply to the first dehumidifying heater 8 is stopped. The second dehumidifying heater 9 is on / off controlled by the engine controller 15 so as to reach a predetermined temperature.

  Although not shown, each photoconductive drum 40 is provided with a temperature sensor, and an output signal thereof is input to the engine controller 15. The engine controller 15 detects a detected value by a temperature sensor and a humidity sensor for measuring outside air installed in the apparatus. Based on the above, the triac 16 is controlled so that the photosensitive drum 40 is maintained at a predetermined temperature at which no condensation occurs. As a result, the temperature of the photosensitive drum 40 can be maintained at a predetermined temperature regardless of fluctuations in the internal temperature due to heat radiation from the heat fixing means 5, and the toner contained in the developing unit 42 is abnormally heated. Thus, the charging amount is controlled so as not to cause inconveniences such as a decrease in density due to a change in charge amount.

  When the standby state for a predetermined time continues after the thermal fixing unit 5 is controlled to a predetermined temperature and the image forming apparatus becomes operable, the main controller 14 turns off the transistor 18 and shifts to the power saving mode. When the transistor 18 is turned off, the power supply to the engine controller 15 is cut off, and accordingly, the switch 18 is turned on, power from the DC power supply 13 is supplied via the resistor 17 and the triac 16 is turned on. Therefore, in the power saving consumption mode, power is always supplied to the second heater 9.

  In other words, power is supplied by a first power supply circuit A (configured by elements constituting a power supply loop formed when the power supply circuit 10 is turned off). Power is supplied by one dehumidifying heater 8 and a second power supply circuit B (configured by elements constituting a power supply loop formed when the power supply switch 10 is turned on and controlled when the power switch 10 is turned on). A second dehumidifying heater 9 is provided, and the second power feeding circuit B is configured by a control circuit C (configured by an engine controller 15, a resistor 17, a switch 18, and a triac 16) that switches between a power saving mode and a normal mode. The second power supply circuit B controls the second dehumidifying heater 9 to a predetermined target temperature based on the environmental state in the normal mode, and the power saving consumption mode It is configured to be switched to power at all times to the second dehumidification heater 9.

  It goes without saying that the constituent circuits of the dehumidification control device shown in the above-described embodiment are merely examples, and can be appropriately changed and designed within a range where the operation of the present invention is good or bad.

Illustration of the image forming apparatus Circuit diagram of dehumidification control device

Explanation of symbols

8: First dehumidifying heater 9: Second dehumidifying heater 10: Power switch A: First power feeding circuit A
B: Second power supply circuit C: Control circuit

Claims (3)

An image forming unit that forms a toner image based on image data, a sheet feeding and conveying unit that feeds and conveys a sheet on which the formed toner image is transferred, and a thermal fixing unit that thermally fixes the image transferred to the sheet. A dehumidification control device for an image forming apparatus that controls a dehumidifying heater that is installed at a plurality of locations in the apparatus and dehumidifies by heating a predetermined portion,
Power is supplied when the power switch of the image forming apparatus is turned off, and is supplied by a first power supply circuit that is supplied with power when the power switch is turned off. A dehumidification control device for an image forming apparatus, comprising: a second dehumidifying heater that is fed by a second feeding circuit, and a control circuit that switches the second feeding circuit between a power saving consumption mode and a normal mode.   The second power supply circuit controls the second dehumidifying heater to a predetermined target temperature based on an environmental condition in the normal mode, and constantly supplies power to the second dehumidifying heater in the power saving consumption mode. The dehumidification control device for an image forming apparatus according to claim 1, wherein the dehumidification control device is switched.   3. The dehumidifying heater for a sheet feeding cassette that dehumidifies paper, and the second dehumidifying heater for dehumidifying a photosensitive drum of the image forming unit. Dehumidification control device of image forming apparatus.

Images