JP2013186327A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent dew condensation from forming inside a touch panel due to an environmental change when an image forming apparatus is not in a normal operation state and to suppress the occurrence of a defect in visibility of a liquid crystal display or a defect in operability of the touch panel.SOLUTION: An image forming apparatus comprises a liquid crystal display 32 and an input operation part 30 comprising a touch panel 40. It also comprises an operation state setting part (constituted by including a control part 60 and a sub power supply SW). The operation state setting part sets it to one operation state from among a plurality of operation states including a first state (a normal operation state) in which a power supply part supplies power to the input operation part 30 and an image forming part 2 and a second state (a special suspension state) in which the power supply part does not supply power to the image forming part 2 and supplies power to at least the liquid crystal display 32 among components of the input operation part 30. When it is set to a second state, a back light control part 62 energizes a back light 36 of the liquid crystal display 32.

Description

  The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus including a liquid crystal display device and an input operation unit having a touch panel arranged on a display screen side of the liquid crystal display device.

  In recent years, an input operation unit of an image forming apparatus employs a display screen of a liquid crystal display device provided with a light transmissive touch panel. The user visually recognizes characters, symbols, and patterns displayed on the display screen through the touch panel. Then, the user performs a switching operation of each function of the image forming apparatus by pressing a portion where a picture or the like to be selected is displayed. Here, the touch panel has a two-layer structure including an upper conductive layer and a lower conductive layer. Therefore, there is a gap between the upper conductive layer and the lower conductive layer. Conventionally, the air in the gap has been cooled and condensation has occurred. That is, when used in a high temperature and high humidity condition, and then the temperature drops, there may be a problem that water droplets adhere to the inside of the touch panel. When such a condensation problem occurs, it becomes difficult to visually recognize the display screen of the liquid crystal display device behind the touch panel. Further, the electrical contact / separation between the upper conductive layer and the lower conductive layer of the touch panel becomes unstable. Therefore, a touch panel shown in the following Patent Document 1 has been proposed as a touch panel in consideration of measures against condensation.

  The touch panel shown in Patent Document 1 includes an upper substrate on which an upper conductive layer is formed and a lower substrate on which a lower conductive layer is formed. The touch panel also includes a dot spacer for securing a gap between the two substrates, a bonding material for bonding the outer peripheral portions of the two substrates, and electrodes disposed on the outer peripheral portions of the two substrates. A desiccant is disposed on the dot spacers, the bonding material, and the electrodes. Therefore, in this touch panel, it is said that the occurrence of dew condensation can be suppressed by the moisture absorbing action of the desiccant.

JP 2006-215941 A

  However, it is assumed that dew condensation cannot be prevented even when the touch panel including the desiccant is incorporated in the input operation unit of the image forming apparatus as described above. This is because the installation environment of the image forming apparatus is not strictly controlled in terms of temperature and humidity as compared with precision equipment such as medical equipment. For this reason, there is a usage environment in which the room is operating in a particularly humid room, the operation is stopped at night, and the room temperature decreases. In addition, the desiccant cannot absorb any amount of moisture, and its hygroscopic effect is limited. Therefore, the moisture absorption action by the desiccant may inevitably cause condensation inside the touch panel.

  In view of this, the present invention prevents the occurrence of condensation inside the touch panel due to environmental changes when the image forming apparatus is not in a normal operating state, and prevents the occurrence of poor visibility of the liquid crystal display device and poor operability of the touch panel. The purpose is to suppress.

  An image forming apparatus according to the present invention includes an input operation unit that can be operated by a user, an image forming unit that forms an image on a sheet based on an instruction input to the input operation unit, and at least the input operation unit and the image forming unit. A power supply unit for supplying power to the unit. The input operation unit includes a liquid crystal display device having a liquid crystal panel on which a display screen is formed, a backlight for illuminating the liquid crystal panel, and a touch panel mounted on the display screen side of the liquid crystal display device. The touch panel includes an upper conductive layer and a lower conductive layer disposed to face the upper conductive layer with a space therebetween, and is configured to output a signal indicating a contact position by contact between the two conductive layers. Is. Further, the image forming apparatus includes a first state in which the power supply unit supplies power to the input operation unit and the image forming unit, and the power supply unit does not supply power to the image forming unit. An operation state setting unit for setting one operation state from among a plurality of operation states including a second state for supplying power to at least the liquid crystal display device; a backlight control unit for performing energization control of the backlight; , Provided. The backlight control unit energizes the backlight when the operating state setting unit sets the second state.

  According to the present invention, the backlight is energized even if it is not in a normal operating state (corresponding to the first state) in which power is supplied to the image forming unit. Therefore, the surface temperature of the touch panel when it is not in a normal operating state can be improved by the heat generation of the backlight. Therefore, it is possible to prevent condensation from forming inside the touch panel.

  Here, the image forming apparatus of the present invention includes a display control unit that controls display contents of the display screen, and the display control unit is set to the second state by the operating state setting unit. It is desirable that the display content for notifying that the state is the second state is displayed on the display screen. With this configuration, the user of the image forming apparatus can be notified of the second state. In addition, lighting of the backlight for suppressing condensation can be effectively used for image display.

  In addition, the image forming apparatus of the present invention preferably includes a light amount control unit that controls the light amount of the backlight in the second state. If comprised in this way, the heat_generation | fever temperature of a backlight can be changed by changing the light quantity of a backlight. Therefore, the power consumption can be suppressed by turning on the backlight with the minimum amount of light necessary to suppress condensation.

  In addition, the image forming apparatus of the present invention includes a time measuring unit that acquires time information, and the time measuring unit acquires information on an elapsed time since the second state is set or information on a current time as the time information. The backlight control unit controls whether or not the backlight is energized in the second state according to the energization mode determined corresponding to the time information acquired by the time measuring unit. It is desirable to have a configuration that is a thing. If comprised in this way, a power consumption can be suppressed by defining an energization aspect so that a backlight may be energized only for the time required for dew condensation suppression.

  In addition, the image forming apparatus of the present invention includes a time measuring unit that acquires time information, a storage unit that stores a time light amount table in which the light amount of the backlight is determined corresponding to the time information acquired by the time measuring unit, The time measuring unit obtains information on the elapsed time since the setting of the second state or information on the current time as the time information, and the light amount control unit stores the information in the storage unit. It is desirable that the light quantity of the backlight in the second state is controlled according to the time light quantity table. If comprised in this way, power consumption can be suppressed by defining a time light quantity table so that a backlight may be turned on with the light quantity required for dew condensation suppression. That is, it is possible to reliably adjust the amount of light of the backlight necessary for suppressing condensation on the basis of time information such as the elapsed time or the current time after the second state is set.

  The image forming apparatus according to the present invention further includes a temperature measuring unit that measures an in-machine temperature, and the backlight control unit is configured to perform the first operation according to an energization mode determined corresponding to the in-machine temperature measured by the temperature measuring unit. It is good also as a structure which controls the presence or absence of electricity supply to the said backlight in the state of 2. FIG. If comprised in this way, power consumption can be suppressed by determining the energization mode so that the backlight is energized only at a temperature at which condensation can occur.

  The image forming apparatus of the present invention also includes a temperature measurement unit that measures the temperature inside the apparatus, and a storage unit that stores a temperature light quantity table in which the light quantity of the backlight is determined corresponding to the temperature inside the apparatus measured by the temperature measurement unit. The light quantity control unit may control the light quantity of the backlight in the second state according to the temperature light quantity table stored in the storage unit. If comprised in this way, power consumption can be suppressed by defining a temperature light quantity table so that a backlight may be turned on with the light quantity required for dew condensation suppression. That is, it is possible to reliably adjust the light amount of the backlight necessary for suppressing condensation based on the measured temperature.

  The image forming apparatus according to the present invention also provides a current for sending the power supplied to the image forming apparatus to the input operation unit without opening or closing a current path for sending the power supplied to the image forming apparatus to the image forming unit. A relay unit that opens and closes a path (hereinafter referred to as a “current path to the input operation unit”), and the operation state setting unit is configured to set the second state to a current path to the input operation unit. It is desirable that the relay unit is controlled to be closed. With this configuration, it is possible to control only the power supply to the input operation unit without affecting the power supply to the image forming unit by opening and closing the current path by the relay unit. Accordingly, the second state can be set by closing the relay unit.

  According to the image forming apparatus of the present invention, it is possible to prevent dew condensation from occurring inside the touch panel due to environmental changes when the image forming apparatus is not in a normal operating state (first state), and to improve the visibility of the liquid crystal display device. Occurrence of defects or touch panel operability defects can be suppressed.

1 is a diagram illustrating a configuration of an image forming apparatus according to a first embodiment. It is a block diagram which shows the structure of the input operation part of a 1st form. It is sectional drawing which shows the structure of a touchscreen. It is a block diagram which shows the electric power supply path | route of a 1st form. It is a block diagram which shows the structure of the input operation part of 1st form, and a control part, and the mode of the electric power supply to each part. It is a timing chart which shows the power supply control sequence of a 1st form. It is a flowchart of the condensation suppression process performed with a 1st form. It is a flowchart of the condensation suppression process performed with a 2nd form. It is a block diagram which shows the structure of the input operation part of a 3rd form, and a control part. It is a flowchart of the dew condensation suppression process performed with a 3rd form. It is a block diagram which shows the structure of the input operation part and control part of a 4th form. It is a flowchart of the dew condensation suppression process performed with the 4th form and the 5th form. It is a block diagram which shows the structure of the input operation part of 5th form, and a control part.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will be described below in detail with reference to the accompanying drawings. This embodiment embodies the present invention in an electrophotographic image forming apparatus.

[First embodiment]
<Configuration of image forming apparatus>
FIG. 1 shows a schematic configuration of an image forming apparatus 1 of the present embodiment. The image forming apparatus 1 is a so-called tandem color printer. The image forming apparatus 1 includes an image forming unit 2, an input operation unit 30, a control unit 60 (see FIG. 4), and a power supply unit 80 (see FIG. 4). The input operation unit 30, the control unit 60, and the power supply unit 80 will be described later. The image forming unit 2 includes an intermediate transfer belt 7 and a process unit 71. The intermediate transfer belt 7 is an endless belt member having conductivity. The intermediate transfer belt 7 is supported by rollers 26 and 27 at two upper end portions. Rollers 28 and 29 are also provided at two locations on the lower end of the intermediate transfer belt 7. At the time of image formation, these rollers 26, 27, 28 and 29 are driven to rotate clockwise. As a result, the intermediate transfer belt 7 is driven to rotate.

  The process unit 71 forms a toner image having a predetermined density on the belt surface of the intermediate transfer belt 7 that moves at a predetermined speed. The process unit 71 includes an image forming unit 10Y that forms a yellow (Y) image, an image forming unit 10M that forms a magenta (M) image, and an image forming unit that forms a cyan (C) image. 10C and an image forming unit 10K that forms a black (K) color image.

  The image forming unit 10Y has a photosensitive drum 3Y. In addition, the image forming unit 10Y includes a charging unit 4Y, an optical writing unit 5Y, a developing device 6Y, and a cleaning unit 9Y that are arranged around the photosensitive drum 3Y. The other image forming units 10M, 10C, and 10K are configured similarly to the image forming unit 10Y. That is, each of the image forming units 10M, 10C, and 10K includes, as shown in FIG. 1, the photosensitive drums 3M, 3C, and 3K, and the charging unit 4M disposed around the photosensitive drums 3M, 3C, and 3K, respectively. , 4C, 4K, optical writing units 5M, 5C, 5K, developing devices 6M, 6C, 6K, and cleaning units 9M, 9C, 9K. In the following description, Y, M, C, and K are not attached unless otherwise distinguished.

  In the image forming unit 10, the charging unit 4 charges the surface of the photosensitive drum 3. The optical writing unit 5 exposes the charged photosensitive drum 3 based on image data corresponding to the image forming color. That is, the photosensitive drum 3 is irradiated with laser beam light for each line, and an electrostatic latent image based on image data is formed. The developing device 6 develops this electrostatic latent image. As a result, a toner image which is a visible image is formed on the photosensitive drum 3.

  In this way, a yellow (Y) toner image is formed on the photosensitive drum 3Y, a magenta (M) toner image is printed on the photosensitive drum 3M, and a cyan (C) toner is printed on the photosensitive drum 3C. A black (K) toner image is formed on the photosensitive drum 3K. The toner images of the respective colors formed on the photosensitive drum 3 are transferred to the intermediate transfer belt 7 by primary transfer rollers 8Y, 8M, 8C, and 8K provided corresponding to the photosensitive drums 3Y, 3M, 3C, and 3K. Is done. This is called “primary transfer”.

  The toner image formed on the intermediate transfer belt 7 is sequentially transferred toward the secondary transfer unit 11 by rotating the intermediate transfer belt 7 in the clockwise direction in FIG. 1 according to the rotation of the plurality of rollers 26, 27, 28, and 29. Sent. The secondary transfer unit 11 is disposed below the intermediate transfer belt 7 in the drawing.

  The image forming apparatus 1 also includes a paper supply unit 15. The paper supply unit 15 includes a paper feed tray that stores plain paper, thin paper, thick paper, coated paper, and the like of a plurality of sizes, and a large-capacity paper feeder (PFU). The paper P supplied by the paper supply unit 15 is conveyed to the secondary transfer unit 11 through the loop roller 22 and the registration roller 23.

  The toner image formed on the intermediate transfer belt 7 is collectively transferred from the intermediate transfer belt 7 to the paper P in the secondary transfer unit 11. This is called secondary transfer. A fixing device 17 is provided on the downstream side of the secondary transfer unit 11 in the paper transport path. The fixing device 17 includes a fixing heater 17a (see FIG. 4) and a nip roller 17b. The fixing device 17 performs fixing processing of the color image transferred to the paper P by applying pressure while heating the paper P by the fixing heater 17a and the nip roller 17b. The paper after fixing is discharged through a paper discharge roller 24. Note that the image forming apparatus 1 can perform not only single-sided printing but also double-sided printing. During single-sided printing, the paper after color image fixing is discharged as it is. During double-sided printing, an image is also formed on the back side of the paper after fixing the color image.

  A cleaning unit 9 provided on the lower left side of the photosensitive drum 3 removes the toner agent remaining on the photosensitive drum 3 after the primary transfer. A cleaning unit 12 is also provided at the upper left of the intermediate transfer belt 7. The cleaning unit 12 removes residual toner remaining on the intermediate transfer belt 7 after the secondary transfer.

  FIG. 2 shows the configuration of the input operation unit 30 of the image forming apparatus 1. The input operation unit 30 includes a liquid crystal monitor unit 31 and a numeric keypad unit 50. The liquid crystal monitor unit 31 includes a liquid crystal display device (LCD) 32 and a touch panel 40. The numeric keypad 50 includes a start key for instructing start of printing, a stop key for instructing to stop printing, a reset key for resetting input contents, a number key for inputting various numerical values such as the number of copies, and a selection key for selecting a function. And the like, and a plurality of hard keys 51. The user performs input operations such as various settings using the touch panel 40 and the hard keys 51.

  The pressing operation of each key 51 by the user is detected by a switch 51 a provided on each key 51. The numeric keypad 50 is provided with an input control CPU 56. The detection signal from the switch 51a is input to the input control CPU 56 and processed. Further, the start key and the stop key are provided with a lighting portion composed of an LED 52. The LED 52 is controlled to be turned on by the input control CPU 56. For example, the LED 52 provided in the start key is controlled to be lit in blue to indicate that the user can perform a pressing operation. In addition, the lighting control is performed in red, which indicates that the user cannot perform the pressing operation. In addition, the numeric keypad 50 is provided with an LED (hereinafter referred to as “operation status display unit 53”) for indicating the operation status of the image forming apparatus 1. The operating state display unit 53 is controlled to be turned on in three modes: off, red, and blue. Here, the image forming apparatus 1 is provided with a main power switch 66 and a sub power switch 67 (see FIG. 4).

  When the main power switch 66 is off, the operating state display unit 53 is in an extinguished state. The state of the image forming apparatus 1 when the main power switch 66 is off is referred to as “non-operating state”. Further, when the main power switch 66 is on and the sub power switch 67 is off, the operating state display unit 53 is controlled to be in a red lighting state. The state of the image forming apparatus 1 when the main power switch 66 is on and the sub power switch 67 is off is referred to as “pause state”. In the hibernation state, as will be described later, “normal hibernation state” in which power is not supplied to the input operation unit 30 and the image forming unit 2 except the operation state display unit 53 and power is supplied to the control unit 60, and image formation is performed. There is a “special sleep state (corresponding to the second state)” in which power is not supplied to the unit 2 and power is supplied to the control unit 60 and the liquid crystal display device 32 of the input operation unit 30. Further, when the main power switch 66 is on and the sub power switch 67 is on, the operating state display unit 53 is controlled to be in a blue lighting state. The state of the image forming apparatus 1 when the main power switch 66 is on and the sub power switch 67 is on is referred to as “normal operating state (corresponding to the first state)”. It is not the input control CPU 56 provided in the numeric keypad unit 50 but the main CPU 61 provided in the control unit 60 that controls the lighting of the operating state display unit 53.

  The liquid crystal display device 32 includes a liquid crystal panel (LCD panel) 33 and a backlight 36 that irradiates the liquid crystal panel 33 from behind. The liquid crystal panel 33 is a TFT (Thin Film Transistor) type liquid crystal panel. The liquid crystal panel 33 has a display screen 34. The backlight 36 uses an LED. On the display screen 34 of the liquid crystal display device 32, soft keys necessary for an input operation using the touch panel 40 are displayed.

  The touch panel 40 is disposed on the display screen 34 side (front side as viewed from the user) of the liquid crystal display device 32. The touch panel 40 is a pointing device (position input device) that exhibits a position input function, and is a resistive film type. Specifically, as shown in FIG. 3, the touch panel 40 includes a film 41 on which a resistive film 42 is formed and a glass 44 on which a resistive film 45 is formed. The film 41 and the glass 44 are arranged to face each other with the resistance films 42 and 45 facing each other in a state where a certain gap is secured. The film 41 is also referred to as a light transmissive upper substrate having an upper conductive layer (resistive film 42) formed on the lower surface. The glass 44 is also referred to as a light-transmitting lower substrate having a lower conductive layer (resistive film 45) formed on the upper surface. Only the outer periphery of the film 41 and the glass 44 is bonded with a bonding material 47. The bonding material 47 is made of an insulating material that can be adhered and adhered, such as epoxy resin or silicon resin. In addition, since the touch panel 40 detects the position by the contact between the two resistance films 42 and 45, it is necessary to prevent the two resistance films 42 and 45 from contacting each other even if the film 41 is deformed when there is no load. Therefore, a dot spacer 48 is provided between the resistance films 42 and 45. Electrodes (not shown) are provided on the left and right ends of the film 41 and the upper and lower ends of the glass 44. The electrodes at the left and right ends of the film 41 apply a voltage for determining the X coordinate of the pressed position. A voltage for determining the Y coordinate of the pressed position is applied to the upper and lower electrodes of the glass 44. The touch panel is provided with a wiring member (not shown). Position information based on the potential at the contact point between the two resistance films 42 and 45 is output to the input control CPU 56 of the numeric keypad 50 via the wiring member (not shown). In addition, the location where condensation occurs for the purpose of suppressing the image forming apparatus 1 of the embodiment is a space between both the resistance films 42 and 45.

  An input operation by the user using the touch panel 40 and the liquid crystal display device 32 configured as described above is performed as follows. First, a plurality of soft keys are displayed in color on the display screen 34 of the liquid crystal display device 32. The user touches the touch panel 40 of the display location with a finger or a pen. Then, since the detected potential of the contact point between the two resistance films 42 and 45 differs depending on the touched location, the touch panel 40 outputs position information corresponding to the detected potential to the input control CPU 56 of the numeric keypad 50 ( (See FIG. 2). An input signal from the touch panel 40 is subjected to coordinate determination by the input control CPU 56 of the numeric keypad 50. That is, it is determined whether the point at the coordinate in the X direction or the Y direction has been operated. The input control CPU 56 of the numeric keypad 50 is connected to the main CPU 61 of the control unit 60 so as to be communicable. The liquid crystal display device 32 is connected to the control unit 60.

  FIG. 4 is a diagram showing a schematic power supply path in the image forming apparatus 1. As shown in FIG. 4, the image forming apparatus 1 can supply power from the power supply unit 80 to the control unit 60, the input operation unit 30, and the image forming unit 2. In addition, the image forming apparatus 1 includes a main power supply SW (switch) 66 in the power supply unit 80. The image forming apparatus 1 is installed indoors and connected to an outlet for use. When the main power supply SW66 is turned on, the AC 100V power input to the image forming apparatus 1 is converted into power having a current value according to the operation standard by the DC power supply unit 81 (that is, the AC-DC converter 81). It is supplied to the control unit 60. The control unit 60 is provided with a main CPU 61 that controls the entire image forming apparatus 1. A sub power supply SW 67 is connected to the main CPU 61. When the sub power supply SW 67 is turned on, the main CPU 61 that has received an input signal from the sub power supply SW 67 operates a first relay (corresponding to a relay section) 68 provided in the power supply section 80. The first relay 68 is provided in the middle of a power supply path that converts AC 100V power by the AC-DC converter 81 and supplies the converted power to the liquid crystal display device 32. More specifically, it is provided upstream of the AC-DC converter 81 on the power supply path to the liquid crystal display device 32. When the contact of the first relay 68 is closed by the main CPU 61, power is supplied to the liquid crystal display device 32 provided in the input operation unit 30. Here, the first relay 68 is disposed on the power supply path for supplying the alternating current input to the image forming apparatus 1 to the liquid crystal display device 32, and the power supply path to the control unit 60 and the image forming unit 2. Not placed on top. Therefore, by operating the first relay 68, it is possible to control only the power supply to the liquid crystal display device 32 without affecting the power supply to the control unit 60 and the image forming unit 2.

  When the sub power SW 67 is turned on, the main CPU 61 that has received an input signal from the sub power SW 67 outputs a mechanical control power control signal to the DC power source 81. As a result, power is supplied from the DC power supply unit 81 to the image forming unit 2 so that the image forming unit 2 can operate. Here, the main CPU 61 is communicably connected to a mechanical control CPU 2 a provided in the image forming unit 2. The mechanical control CPU 2 a controls the operation of each unit (process unit 71 and the like) constituting the image forming unit 2 based on a signal from the main CPU 61. Further, the mechanical control CPU 2 a controls the operation of the second relay 69. The second relay 69 is provided in the middle of the power supply path for supplying AC 100V power to the fixing heater 17a. When the contact of the second relay 69 is closed by the mechanical control CPU 2a, electric power is supplied to the fixing heater 17a.

  Here, the power supplied to the control unit 60 when the main power supply SW 66 is turned on is referred to as “power supply 1”. The power source 1 supplies power not only to the control unit 60 but also to an operation state display unit 53 provided in the numeric keypad unit 50 as shown in FIG. The power supplied to the liquid crystal display device 32 of the input operation unit 30 when the sub power supply SW 67 is turned on, that is, when the contact of the first relay 68 is closed is referred to as “power supply 2”. The power source 2 supplies power to the backlight 36 and the LCD panel 33 of the liquid crystal display device 32 as shown in FIG. Further, when the power supply 2 is supplied, power is also supplied to the backlight control unit 62 and the display control unit 63 provided in the control unit 60 as shown in FIG. The backlight control unit 62 and the display control unit 63 will be described later. The power supplied to the image forming unit 2 when the mechanical control power control signal is output from the main CPU 61 of the control unit 60 is referred to as “power source 3”. The power supply 3 supplies power not only to the image forming unit 2 but also to the input control CPU 56 provided in the numeric keypad unit 50 as shown in FIG.

  FIG. 5 is a schematic block diagram of the input operation unit 30 and the control unit 60. As shown in FIG. 5, the control unit 60 includes a backlight control unit 62 and a display control unit 63 in addition to the main CPU 61. The backlight control unit 62 controls energization of the backlight 36 to control lighting / extinguishing of the backlight 36. Further, the display control unit 63 controls the display content of the display screen 34 of the LCD panel 33. Specifically, the display control unit 63 outputs display data corresponding to the display content to the LCD panel 33. Thereby, the display content based on the output display data is displayed on the LCD panel 33. Although the backlight control unit 62 and the display control unit 63 are described separately from the main CPU 61 in FIG. 5 for convenience, the backlight control unit 62 and the display control unit 63 are configured to include the main CPU 61.

  FIG. 6 is a timing chart summarizing the power supply control sequence in the image forming apparatus 1. As shown in FIG. 6, when the main power SW 66 is turned on, the power 1 is supplied. When the sub power SW 67 is turned on, a relay control signal is output from the main CPU 61. As a result, the contact of the first relay 68 is closed, so that the power source 2 is supplied. When the sub power SW 67 is turned on, the main CPU 61 outputs a mechanical control power control signal. Thereby, the power supply 3 is supplied. This state corresponds to the above-described normal operation state (first state).

  When the sub power supply SW67 is turned off from the normal operating state, the output of the relay control signal is stopped as shown by the broken line in FIG. As a result, the contact of the first relay 68 is opened, and the supply of the power supply 2 is stopped. Further, when the sub power SW 67 is turned off, the output of the mechanical control power control signal is stopped. Thereby, supply of the power supply 3 stops. This state corresponds to the normal rest state among the above rest states.

  Here, the image forming apparatus 1 of the embodiment is not only in the normal hibernation state in which the output of the relay control signal is stopped when the sub power source SW 67 is turned off from the normal operation state, but also when the sub power source SW 67 is turned off from the normal operation state. A special pause state (second state) in which the output of the relay control signal is continued can be taken. The setting of whether to enter the normal hibernation state or the special hibernation state when the sub power supply SW 67 is turned off is performed by operating the input operation unit 30 by the user. When the special power-off state is set, even if the sub power SW 67 is turned off, the relay control signal continues to be output as indicated by the solid line in FIG. 6, and only the mechanical control power control signal is stopped. Accordingly, as shown by the solid line in FIG. 6, the supply of the power supply 2 is continued and the supply of the power supply 3 is stopped. As described below, the special hibernation state in which power is not supplied to the image forming unit 2 but power is supplied to the liquid crystal display device 32 is provided by energizing the backlight 36 as described later. This is to prevent temperature drop. Hereinafter, setting the special sleep state is also referred to as turning on the condensation suppression function. Also, setting the special power-off state when the sub power SW 67 is turned off is also expressed as selecting the dew condensation suppression function.

<Operation of image forming apparatus>
Next, the operation of the image forming apparatus 1 when the normal operation state is switched to the special suspension state will be described based on the flowchart shown in FIG. When the image forming apparatus 1 is switched to the special hibernation state, the following dew condensation suppressing process is performed. In this specification, the special pause state in which the condensation suppression process is performed is also referred to as a condensation suppression mode.

  [Dew condensation suppression process] When the sub power supply is turned off (step S001), the control unit 60 determines whether or not the condensation suppression function is selected (S002). If it is not selected (S002: No), it operates according to the power supply control sequence when the dew condensation suppression function is not selected, which is partially shown by broken lines in FIG. 6 (S003). That is, the output of the relay control signal is stopped, and the supply of the power source 2 is stopped. Further, the output of the mechanical control power control signal is stopped, and the supply of the power source 3 is stopped. As a result, the image forming apparatus 1 enters the normal pause state described above (S004).

  On the other hand, when the dew condensation suppression function is selected (S002: Yes), the operation is performed according to the power supply control sequence when the dew condensation suppression function is selected, which is indicated by a solid line in FIG. 6 (S005). That is, the output of the relay control signal is continued and the supply of the power source 2 is continued. However, the output of the mechanical control power control signal is stopped and the supply of the power source 3 is stopped. As a result, the image forming apparatus 1 enters the above-described special sleep state.

  After entering the special sleep state, the control unit 60 turns on the operating state display unit 53 (see FIG. 2) in red (S006). As a result, the user is notified that the dew condensation suppression function is in a special sleep state. Subsequently, the display control unit 63 sets display data on the LCD panel 33 (S007). In this embodiment, the display data is data for displaying a black single image on the LCD panel 33. In step S007, the backlight control unit 62 further energizes and turns on the backlight 36. As a result, the display screen 34 of the LCD panel 33 becomes black.

  Subsequently, the control unit 60 determines whether or not the sub power supply SW67 is turned on (S008). If it is not turned on (S008: No), the above steps S006 and S007 are repeated. On the other hand, when the sub power supply SW67 is turned on, the mechanical control power supply control signal is output and the power supply 3 is supplied as shown in the power supply control sequence of FIG. As a result, the image forming apparatus 1 enters the normal operation state described above (S009).

  As described above, the image forming apparatus 1 turns on the backlight 36 when the image forming apparatus 1 is set in the special pause state in which the dew condensation suppressing function is activated. Thereby, the surface temperature of the touch panel 40 can be improved. Therefore, it is possible to prevent condensation from forming inside the touch panel 40 even after the operation of the image forming unit 2 is stopped. Therefore, it is possible to suppress the occurrence of poor visibility of the liquid crystal display device 32 and poor operability of the touch panel 40 due to condensation. In particular, when the touch panel 40 becomes inoperable in the image forming apparatus 1 used for commercial printing, the damage to the user is great. Since the image forming apparatus 1 according to the embodiment contributes to the stable use of the touch panel 40, the occurrence of such damage can be effectively prevented. Note that the backlight 36 uses an LED and generates less heat than that using an incandescent bulb, but is sufficient as a heat generation for preventing condensation.

  Further, the image forming apparatus 1 prevents condensation by turning on the backlight 36. Therefore, the operability of the touch panel 40 is not hindered. That is, as a countermeasure against dew condensation on the touch panel 40, the technique of preventing the sticking between the upper conductive layer 42 and the lower conductive layer 45 by increasing the number of dot spacers 48 increases the input load and impairs light operability. was there. However, in the image forming apparatus 1 of the embodiment, good operability can be maintained.

  Further, the image forming apparatus 1 supplies power to the input operation unit 30 without supplying power to the image forming unit 2. For this reason, the anti-condensation function can be exhibited while suppressing power consumption compared to the existing low power mode. The low power mode is a mode in which the fixing heater 17a is kept at a low power standby so that it can be quickly restarted. In the low power mode, both the input operation unit 30 and the image forming unit 2 are energized, and the power consumption is larger than in the special hibernation state of the embodiment.

  In addition, the image forming apparatus 1 uses the backlight 36 of the liquid crystal display device 32 that is naturally necessary for touch input to prevent condensation on the touch panel 40. Therefore, it is possible to reduce the cost as compared with the case where condensation is prevented by disposing a heating unit and a dehumidifying unit on the touch panel 40 separately. Further, the structure of the touch panel 40 is not complicated. Furthermore, compared to the one that adds a separate component (such as a desiccant) to exert dehumidifying action, it does not depend on the performance of the added component, and exhibits a dew condensation suppression function in any environment. can do. For example, when a desiccant is used, the desiccant may be saturated due to moisture absorption and may not exhibit a dew condensation suppressing function. However, in the embodiment, such a problem does not occur.

[Second form]
The second embodiment will be described. The configuration of the image forming apparatus 1 according to this embodiment and the operation in the normal operation state are the same as those in the first embodiment. This embodiment is different from the first embodiment in the control when set to a special sleep state in which the dew condensation suppression function is activated. That is, in the first embodiment, the operating state display unit 53 is lit red and the display screen 34 of the LCD panel 33 is black. On the other hand, in the present embodiment, the characters “during condensation suppression mode” are displayed on the display screen 34 of the LCD panel 33 without lighting the operation state display unit 53.

  In the present embodiment, the operation of the image forming apparatus 1 when switched to the special sleep state will be described based on the flowchart of FIG. Steps S101 to S105 shown in FIG. 8 are the same processes as steps S001 to S005 shown in FIG. Further, steps S107 and S108 shown in FIG. 8 are the same processes as steps S008 and S009 shown in FIG.

  In the image forming apparatus according to the second embodiment, the control unit 60 displays the characters “in dew condensation suppression mode” on the display screen 34 of the LCD panel 33 after entering the special sleep state (S105) (S106). In other words, the display control unit 63 sets display data for displaying the characters “in the condensation suppression mode”. Further, the backlight control unit 62 turns on the backlight 36. As a result, the characters “in dew condensation suppression mode” are displayed on the display screen 34 of the LCD panel 33. Therefore, it is possible to notify the user that the condensation suppression function is working. In addition, the lighting of the backlight 36 for suppressing dew condensation is effectively used for information presentation by character display.

  In the present embodiment, the process of lighting the operating state display unit 53 in red is not performed (the process of step S006 shown in FIG. 7 is not performed). This is because in the present embodiment, it is possible to notify the user by displaying on the LCD panel 33, so that the display by the operation state display unit 53 is not required. However, display by the operating state display unit 53 may be performed.

[Third embodiment]
A third embodiment will be described. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted. The configuration of the image forming apparatus according to this embodiment is different from that of the first embodiment in that the backlight control unit 62 includes a light amount control unit 64 as shown in FIG. The light quantity control unit 64 controls the light quantity of the backlight 36. Specifically, the light quantity control unit 64 adjusts the current flowing through the LEDs constituting the backlight 36 by performing PWM control (pulse width modulation control). If the current passed through the LED is increased, the brightness of the backlight 36 increases. Conversely, if the current flowing through the LED is reduced, the brightness of the backlight 36 decreases.

  The operation of the image forming apparatus according to the present embodiment is the same as that of the first embodiment in the normal operation state. However, this embodiment is different from the first embodiment in the control when set to the special hibernation state in which the dew condensation suppressing function is activated. That is, in the first embodiment, there is no function for adjusting the amount of light of the backlight 36 when the backlight 36 is turned on. On the other hand, in the present embodiment, it is possible to adjust the light amount of the backlight 36.

  In the present embodiment, the operation of the image forming apparatus 1 when switched to the special sleep state will be described based on the flowchart of FIG. Steps S201 to S206 shown in FIG. 10 are the same processes as steps S001 to S006 shown in FIG. Further, steps S208 and S209 shown in FIG. 10 are the same processes as steps S008 and S009 shown in FIG.

  In the image forming apparatus according to the third embodiment, the control unit 60 turns on the operation state display unit 53 in red (S206) after entering the special sleep state (S205). This notifies the user that the condensation suppression function is working. Subsequently, the display control unit 63 sets display data on the LCD panel 33 (S207). In this embodiment, as in the first embodiment, the display data is data for displaying a full-color image on the LCD panel 33. In step S207, the light amount control unit 64 further adjusts the light amount when the backlight 36 is turned on (sets the luminance of the backlight 36). Then, the backlight control unit 62 turns on the backlight 36 with the luminance set by the light amount control unit 64. As a result, a black single image is displayed on the display screen 34 of the LCD panel 33 with the set light amount. Here, the amount of light for turning on the backlight 36 is set in advance by the user operating the input operation unit 30.

  As described above, the image forming apparatus according to the third embodiment can change the heat generation amount of the backlight 36 by changing the light amount of the backlight 36 in the dew condensation suppression mode. Therefore, the power consumption can be suppressed by turning on the backlight 36 with the minimum amount of light necessary for suppressing condensation. For example, even in the winter when condensation is likely to occur, when the temperature of the place where the image forming apparatus 1 is installed is higher than that on other days, the user can operate the input operation unit 30 in advance to reduce the amount of light from the backlight 36. To light up.

[Fourth form]
A fourth embodiment will be described. In this embodiment, the same components as those in the third embodiment are denoted by the same reference numerals, and description thereof is omitted. In the image forming apparatus according to this embodiment, the control unit 60 includes a time measuring unit that acquires time information. In the embodiment, the time measuring unit is configured to include an RTC (real time clock) 74 attached to the main CPU 61 as shown in FIG. The RTC 74 measures the current time. Based on the information on the current time measured by the RTC 74, the timer unit measures the elapsed time since the special sleep state (condensation suppression mode) is set. Note that if the time measuring unit can measure the elapsed time since the dew condensation suppression mode is set, the main CPU 61 loads a program for time measurement stored in the ROM 76, which will be described later, without including the RTC 74. Other configurations, such as a configuration to execute, may be adopted. For example, a configuration in which the main CPU 61 executes a program for measuring the elapsed time based on the operation clock frequency of the main CPU 61 and the number of clocks to be counted after being set in the special hibernation state, the interrupt cycle and execution of the timer interrupt process A configuration in which the main CPU 61 executes a program for measuring the elapsed time based on the number of times may be employed.

  The main CPU 61 is additionally provided with a ROM (corresponding to a storage unit) 76 storing a program and a RAM 75 serving as an execution area for the program. The ROM 76 stores an elapsed time light amount table 77. The elapsed time light amount table 77 is a table in which the elapsed time measured by the time measuring unit is associated with the light amount of the backlight 36. In the elapsed time light amount table 77, the elapsed time and the light amount are associated so that the light amount of the backlight 36 increases as the elapsed time increases, that is, the luminance of the backlight 36 increases. The light quantity control unit 64 adjusts the light quantity of the backlight 36 according to the elapsed time light quantity table 77. As a result, the light quantity of the backlight 36 can be increased not only immediately after the user turns off the sub power supply SW 67 but as the temperature at the dawn and the place where the image forming apparatus 1 is installed decreases at midnight. That is, the power consumption can be suppressed compared to the case where the backlight 36 is continuously turned on with the maximum light amount immediately after the user turns off the sub power SW 67.

  The operation of the image forming apparatus according to this embodiment is the same as that of the third embodiment in the normal operation state. However, this embodiment is different from the third embodiment in the control when set to the special hibernation state in which the dew condensation suppression function is activated. That is, in the third embodiment, the user presets the light amount of the backlight 36. On the other hand, in this embodiment, the control unit 60 automatically adjusts the light amount of the backlight 36 based on the elapsed time light amount table 77.

  In the present embodiment, the operation of the image forming apparatus 1 when switched to the special sleep state will be described based on the flowchart of FIG. Steps S301 to S306 shown in FIG. 12 are the same processes as steps S201 to S206 shown in FIG. Further, steps S309 and S310 shown in FIG. 12 are the same processes as steps S208 and S209 shown in FIG.

  In the image forming apparatus of the fourth embodiment, the control unit 60 turns on the operating state display unit 53 in red after entering a special sleep state (S305) (S306). This notifies the user that the condensation suppression function is working. Then, the control part 60 acquires the elapsed time after shifting to dew condensation suppression mode by a time measuring part (S307). In step S307, the control unit 60 refers to the elapsed time light amount table 77 stored in the ROM (storage unit) 76 and sets the light amount associated with the acquired elapsed time.

  Thereafter, the display control unit 63 sets display data on the LCD panel 33 (S308). In this embodiment, as in the third embodiment, the display data is data for displaying a full black image on the LCD panel 33. In step S308, the light amount control unit 64 further adjusts the light amount when the backlight 36 is turned on according to the light amount set in step S307 (sets the luminance of the backlight 36). Then, the backlight control unit 62 turns on the backlight 36 with the luminance set by the light amount control unit 64. As a result, a black single image is displayed on the display screen 34 of the LCD panel 33 with the set light amount. Thereafter, the control unit 60 repeats these processes until the sub power supply SW 67 is turned on (S309).

  Here, the elapsed time light amount table 77 associates the elapsed time with the light amount so that the light amount of the backlight 36 increases as the elapsed time increases, that is, the luminance of the backlight 36 increases. . Therefore, the light amount control unit 64 increases the light amount of the backlight 36 not only immediately after the user turns off the sub power supply SW 67 but as the temperature of the setting place of the image forming apparatus 1 becomes lower at midnight. Therefore, in the fourth embodiment, it is possible to reduce power consumption as compared with the case where the backlight 36 is continuously turned on with the maximum light amount immediately after the user turns off the sub power supply SW67. Note that the increase in the amount of light of the backlight 36 with the passage of time is preferably stopped when a predetermined amount of light is reached, and thereafter, the backlight 36 is lit with the amount of light reached. This is because an unlimited increase in the amount of light is against the suppression of power consumption. Further, considering that the temperature at the place where the image forming apparatus 1 is installed gradually rises at the time of sunrise, the amount of light of the backlight increases with time, becomes constant thereafter, and then decreases. May be. In this case, in the elapsed time light amount table, the elapsed time and the light amount are associated with each other so that the light amount of the backlight changes from increasing to constant to decreasing as the elapsed time increases. According to this, not only the power consumption immediately after the user turns off the sub power supply SW 67 but also the power consumption after sunrise can be suppressed.

  In the fourth embodiment, the light amount of the backlight 36 is controlled based on the elapsed time light amount table 77. However, whether the backlight 36 is energized or not is controlled according to the elapsed time acquired by the time measuring unit. You may make it do. As for the relationship between the elapsed time and the energization mode, it is desirable that the backlight 36 is energized not after immediately after the user turns off the sub power supply SW 67 but at a time when condensation starts to occur. Therefore, a program that defines the relationship between the elapsed time and the energization mode is stored in advance in a ROM (storage unit) 76, and the main CPU 61 executes the program. If comprised in this way, since the backlight 36 can be energized and lighted only for the time required for dew condensation suppression, power consumption can be suppressed. Note that the number of hours after the sub power supply SW 67 is turned off may be arbitrarily set by the user by operating the input operation unit 30.

  In the fourth embodiment, the light amount of the backlight 36 is controlled according to the elapsed time light amount table 77 in which the elapsed time since the special sleep state is set and the light amount of the backlight 36 are related. On the other hand, the light amount of the backlight 36 may be controlled according to the current time light amount table 79 that associates the current time obtained from the RTC 74 with the light amount of the backlight 36. In this case, as shown in FIG. 11, a current time light amount table 79 is stored in a ROM (storage unit) 76 instead of the elapsed time light amount table 77. In the current time light quantity table 79, the time and the light quantity are associated with each other in consideration of the change in temperature with respect to the time for each time period (season). For example, the backlight 36 starts to light with a medium amount of light at midnight when the temperature decreases, the light amount of the backlight 36 is increased at 3:00 am when the temperature further decreases, and the backlight 36 increases at 7:00 am when the temperature rises. The current time is associated with the amount of light so that the light 36 is turned off. If the light amount of the backlight 36 is controlled according to the current time light amount table 79, the light amount of the backlight 36 can be optimally adjusted with respect to the time regardless of the time when the user shifts to the special sleep state. .

  In addition, the presence / absence of energization of the backlight 36 may be controlled according to the information on the current time acquired by the time measuring unit without being based on the current time light quantity table 79. Regarding the relationship between the time and the power supply mode, for example, the power supply of the backlight 36 is started when the temperature becomes midnight, and the power supply of the backlight 36 is turned on when the temperature rises at 7:00 am. Configure to be stopped. For this purpose, a program that defines the relationship between the time and the energization mode is stored in advance in a ROM (storage unit) 76, and the main CPU 61 executes the program. With this configuration, whether or not the backlight 36 is energized can be optimally adjusted with respect to the time regardless of the time when the user shifts to the special hibernation state. Note that the timekeeping unit may acquire information on the current time from the outside such as a standard radio wave for a radio clock or a time site for measuring the current time, instead of the RTC 74.

[Fifth embodiment]
A fifth embodiment will be described. In this embodiment, the same components as those in the third embodiment are denoted by the same reference numerals, and description thereof is omitted. In the image forming apparatus according to this embodiment, the input operation unit 30 includes a temperature measurement unit 90 as shown in FIG. The temperature measuring unit 90 includes a thermistor. The temperature measuring unit 90 may employ other configurations such as a thermocouple and bimetal as long as the temperature can be measured. The location of the temperature measurement unit 90 is in the vicinity of the touch panel 40. This is for measuring the in-machine temperature around the touch panel 40 where condensation occurs. Note that power is supplied from the power source 2 to the temperature measurement unit 90.

  The main CPU 61 is additionally provided with a ROM (corresponding to a storage unit) 76 storing a program and a RAM 75 serving as an execution area for the program. A temperature light quantity table 78 is stored in the ROM 76. The temperature light quantity table 78 is a table showing the correspondence between the temperature around the touch panel 40 measured by the temperature measurement unit 90 and the light quantity of the backlight 36. In the temperature light quantity table 78, the temperature and the light quantity are associated so that the light quantity of the backlight 36 increases as the temperature decreases, that is, the luminance of the backlight 36 increases. The light quantity control unit 64 adjusts the light quantity of the backlight 36 according to the temperature light quantity table 78. Thereby, after the user turns off the sub power SW 67, the light quantity of the backlight 36 can be increased at midnight and as the temperature of the installation place of the image forming apparatus 1 decreases. Moreover, the light quantity of the backlight 36 can be decreased as temperature rises gradually from sunrise. According to this, power consumption can be suppressed as compared with the case where the backlight 36 is continuously turned on with the maximum light amount immediately after the user turns off the sub power SW 67.

  The operation of the image forming apparatus according to this embodiment is obtained by changing the processing in step S307 shown in FIG. 12 in the fourth embodiment to step S317 shown in FIG. That is, the fourth embodiment is configured to adjust the light amount of the backlight 36 based on the elapsed time light amount table 77. On the other hand, in this embodiment, the light quantity of the backlight 36 is adjusted based on the temperature light quantity table 78.

  In the present embodiment, the operation of the image forming apparatus 1 when switched to the special sleep state will be described based on the flowchart of FIG. Description of the same processing as in the fourth embodiment is omitted. As shown in FIG. 12, in the image forming apparatus 1 according to the fifth embodiment, the control unit 60 turns on the operating state display unit 53 in red (S306) after entering the special sleep state (S305). This notifies the user that the condensation suppression function is working. Subsequently, the control unit 60 acquires the temperature measured by the temperature measurement unit 90 (S317). The temperature measuring unit 90 is disposed in the vicinity of the touch panel 40 as described above. Therefore, the temperature measured by the temperature measuring unit 90 is the ambient temperature of the touch panel 40 where condensation occurs. In step S317, the control unit 60 refers to the temperature light amount table 78 stored in the ROM (storage unit) 76, and sets the light amount associated with the acquired temperature.

  Thereafter, the display control unit 63 sets display data on the LCD panel 33 (S308). In this embodiment, as in the fourth embodiment, the display data is data for displaying a full black image on the LCD panel 33. In step S308, the light amount control unit 64 further adjusts the light amount when the backlight 36 is turned on according to the light amount set in step S317 (sets the luminance of the backlight 36). Then, the backlight control unit 62 turns on the backlight 36 with the luminance set by the light amount control unit 64. As a result, a black single image is displayed on the display screen 34 of the LCD panel 33 with the set light amount. Thereafter, the control unit 60 repeats these processes until the sub power supply SW 67 is turned on (S309).

  Here, in the temperature light amount table 78, the temperature and the light amount are associated with each other so that the light amount of the backlight 36 increases as the temperature decreases, that is, the luminance of the backlight 36 increases. Therefore, after the user turns off the sub power supply SW 67, the light amount control unit 64 increases the light amount of the backlight 36 at midnight and as the temperature of the installation place of the image forming apparatus 1 decreases. Moreover, the light quantity of the backlight 36 is decreased as the temperature gradually rises from sunrise. Therefore, in the fifth embodiment, it is possible to reduce power consumption as compared with the case where the backlight 36 is continuously turned on with the maximum light amount immediately after the user turns off the sub power supply SW67.

  In the fifth embodiment, the light amount of the backlight 36 is controlled based on the temperature light amount table 78. However, whether or not the backlight 36 is energized is controlled according to the temperature acquired by the temperature measuring unit 90. You may make it do. As for the relationship between the temperature and the energization mode, it is desirable that the backlight 36 is energized not only immediately after the user turns off the sub power supply SW 67 but at a temperature at which condensation may occur. For this purpose, a program that defines the relationship between temperature and energization mode is stored in a ROM (storage unit) 76 in advance, and the main CPU 61 executes this program. With this configuration, the backlight 36 can be energized and lit only when there is a risk of condensation, so that power consumption can be reduced. It should be noted that the number of times the ambient temperature of the touch panel 40 becomes lower or lower may be configured so that the user can arbitrarily set the backlight 36 by operating the input operation unit 30.

  Moreover, it is good also as a structure provided with the humidity measurement part (humidity sensor) which can measure humidity with the temperature measurement part 90. FIG. The dew point temperature at which condensation occurs is determined by the relationship between temperature and humidity. Therefore, if the temperature measurement unit 90 and the humidity measurement unit are provided, the occurrence of condensation can be reliably detected. As with the temperature measurement unit 90, the humidity measurement unit is also preferably disposed near the touch panel 40.

  As described above in detail, the image forming apparatus 1 of the present invention includes the operating state setting unit including the control unit 60 and the sub power supply SW 67, and the backlight control unit 62. When the operation state setting unit sets the special hibernation state, the backlight control unit 62 energizes and turns on the backlight 36. That is, the dew condensation suppression mode can be set. Therefore, it is possible to improve the surface temperature of the touch panel 40 when it is not in a normal operating state. Therefore, it is possible to prevent condensation from forming inside the touch panel 40. As a result, the occurrence of poor visibility of the liquid crystal display device 32 and poor operability of the touch panel 40 can be suppressed.

  Note that this embodiment is merely an example, and does not limit the present invention. Therefore, the present invention can naturally be improved and modified in various ways without departing from the gist thereof. For example, in the first embodiment, the user has set the normal operation state so that the dew condensation prevention function is exhibited when the normal operation state is changed to the special hibernation state (to enter the dew condensation prevention mode). This setting is stored in the internal memory (RAM 75) of the image forming apparatus 1. On the other hand, a switch for exhibiting a dew condensation prevention function (a switch for setting a dew condensation suppression mode; hereinafter referred to as a “mode setting switch”) may be provided separately. This mode setting switch is connected so that it can be operated by the supply of the power supply 1 like the sub power supply SW67. The signal from the mode setting switch is input to the main CPU 61. In this way, it is possible to shift from the normal resting state where the dew condensation prevention function is not working to the special resting state where the dew condensation prevention function is working.

  In addition, whether to set a special hibernation state (condensation suppression mode) in which the dew condensation suppression function is exhibited when the sub power supply SW 67 is turned off or a normal hibernation state in which the dew condensation suppression function is not exhibited is set by an input operation by the user. Although it is configured to be performed based on an operation by the unit 30, it may be configured not to be set by the user. That is, it may be configured such that when the sub power SW 67 is turned off, a transition is made to a special sleep state (condensation suppression mode).

  In the embodiment, the backlight control unit 62 turns on the backlight 36 in a special pause state in which the dew condensation prevention function operates. However, if the heat generation amount for suppressing the dew condensation is sufficient, the backlight 36 is turned on. Only a small amount of current may be applied to the backlight 36.

  Further, in the first and third to fifth embodiments, the display screen 34 is configured to be entirely black, but an arbitrary image can be displayed on the display screen 34. That is, the present invention is aimed at lowering the temperature around the touch panel 40 due to the heat generated by the backlight 36, and therefore any color, shape, character, or the like of the image displayed on the display screen 34 may be used. However, in order to improve the usability of the image forming apparatus 1, it is desirable to provide a display that can notify the user that the condensation prevention function is working.

  In the first and third to fifth embodiments, the operating state display unit 53 (see FIG. 2) is lit in red (see step S006 in FIG. 7), and the user enters a special sleep state in which the dew condensation suppressing function is activated. It is reported that there is a normal pause or special pause, such as red when it is in a normal pause state where the condensation suppression function does not work, and yellow when it is a special operation state where the condensation suppression function is active. It is desirable to change the lighting color of the status display unit 53. With this configuration, even if the user forgets whether or not the condensation suppression function is set to work, it can be identified based on the lighting color.

  The touch panel 40 is a resistive film type, but may be a matrix switch type touch panel. Moreover, although the LED backlight was employ | adopted for the backlight 36, you may employ | adopt the backlight of an incandescent lamp in consideration of making high calorie | heat amount at the time of light emission.

  In the embodiment, the image forming apparatus 1 which is a tandem color printer has been described as an example. However, the present invention is an image forming apparatus including the input operation unit 30 having the touch panel 40 and the liquid crystal display device 32. For example, the present invention can be applied to any type of image forming apparatus. For example, the present invention can also be applied to a so-called four-cycle system in which developing devices for each color are provided around one photoconductor. For example, the present invention can also be applied to an ink jet image forming apparatus. Further, for example, the present invention can be applied to a monochrome copying machine, a printer, a facsimile, or a multifunction machine having these functions in combination.

Note that the control unit 60 and the sub power supply SW 67 of the embodiment constitute an operating state setting unit of the present invention.
Further, the control unit 60 of the embodiment constitutes a backlight control unit 62, a display control unit 63, a light amount control unit 64, and a time measuring unit of the present invention.
The normal operation state of the embodiment corresponds to the “first state” of the present invention, and the special sleep state of the embodiment corresponds to the “second state” of the present invention.
Further, the elapsed time light amount table 77 and the current time light amount table 79 of the embodiment correspond to the “time light amount table” of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus 2 ... Image forming part 30 ... Input operation part 32 ... Liquid crystal display device 33 ... Liquid crystal panel 34 ... Display screen 36 ... Backlight 40 ... Touch panel 41 ... Film 42 ... Resistive film (upper conductive layer) of film
44 ... Glass 45 ... Glass resistance film (lower conductive layer)
60 ... Control unit 62 ... Backlight control unit 63 ... Display control unit 64 ... Light quantity control unit 67 ... Sub power supply SW
68. Relay unit (first relay)
76 ... Storage unit (ROM)
80 ... Power supply unit 90 ... Temperature measurement unit

Claims (8)

An input operation unit operable by the user;
An image forming unit that forms an image on a sheet based on an instruction input to the input operation unit;
A power supply unit that supplies power to at least the input operation unit and the image forming unit,
The input operation unit is
A liquid crystal display device having a liquid crystal panel on which a display screen is formed, and a backlight for illuminating the liquid crystal panel;
A touch panel mounted on the display screen side of the liquid crystal display device,
The touch panel includes an upper conductive layer and a lower conductive layer disposed to face the upper conductive layer with a space therebetween, and is configured to output a signal indicating a contact position by contact between the two conductive layers. An image forming apparatus,
A first state in which the power supply unit supplies power to the input operation unit and the image forming unit, and at least the liquid crystal display device of the input operation unit in which the power supply unit does not supply power to the image forming unit An operation state setting unit for setting one operation state from among a plurality of operation states including a second state for supplying power to
A backlight control unit that performs energization control of the backlight,
The image forming apparatus according to claim 1, wherein the backlight control unit is configured to energize the backlight when the operating state setting unit sets the second state. A display control unit for controlling the display content of the display screen;
The display control unit is configured to display, on the display screen, display contents for informing that the second state is set when the operation state setting unit sets the second state. The image forming apparatus according to claim 1.   The image forming apparatus according to claim 1, further comprising a light amount control unit that controls a light amount of the backlight in the second state. It has a timekeeping part that acquires time information,
The timekeeping unit acquires information on elapsed time since the second state is set or information on current time as the time information,
The backlight control unit is configured to control whether the backlight is energized in the second state in accordance with an energization mode determined corresponding to the time information acquired by the timing unit. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. A timekeeping section for obtaining time information;
A storage unit that stores a time light amount table in which the light amount of the backlight is determined corresponding to the time information acquired by the time measuring unit;
The timekeeping unit acquires information on elapsed time since the second state is set or information on current time as the time information,
The image formation according to claim 3, wherein the light amount control unit controls the light amount of the backlight in the second state according to the temporal light amount table stored in the storage unit. apparatus. It has a temperature measurement unit that measures the temperature inside the machine.
The backlight control unit controls whether the backlight is energized in the second state according to an energization mode determined corresponding to the in-machine temperature measured by the temperature measurement unit. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. A temperature measurement unit that measures the temperature inside the machine,
A storage unit for storing a temperature light amount table in which the light amount of the backlight is determined corresponding to the temperature inside the apparatus measured by the temperature measurement unit;
The image formation according to claim 3, wherein the light amount control unit controls the light amount of the backlight in the second state according to the temperature light amount table stored in the storage unit. apparatus. A current path for sending power supplied to the image forming apparatus to the input operation unit without opening or closing a current path for sending power supplied to the image forming apparatus to the image forming unit (hereinafter referred to as “to the input operation unit”). A relay that opens and closes the current path)
The operation state setting unit controls the relay unit to close the current path to the input operation unit when the second state is set. The image forming apparatus according to any one of 1 to 7.

Images