Patent Publication Number: US-2023133931-A1

Title: Image forming apparatus capable of on-off control of operating key lamp according to anbient illuminance

Description:
INCORPORATION BY REFERENCE 
     This application claims priority to Japanese Patent Application No. 2021-178660 filed on 1 Nov., 2021, the entire contents of which are incorporated by reference herein. 
     BACKGROUND 
     The present disclosure relates to image forming apparatuses. 
     There is generally known an image forming apparatus that predicts its frequency of use based on the number of persons passing by, the surrounding brightness or other factors and, upon determination of low frequency of use, transitions to a power-saving mode for decreasing the fixation temperature. 
     SUMMARY 
     A technique improved over the aforementioned technique is proposed as one aspect of the present disclosure. 
     An image forming apparatus according to an aspect of the present disclosure includes an operating key, an illuminance sensor, and a controller. The operating key contains a lamp. The illuminance sensor detects an ambient illuminance. The controller includes a processor and controls, through the processor executing a control program, turning on and off of the lamp. The operating key functions as a first trigger for return from a power-saving mode, where power consumption is reduced relative to a normal mode, to the normal mode. The controller turns the lamp off when the ambient illuminance detected by the illuminance sensor in the power-saving mode is equal to or more than a first threshold value, and the controller turns the lamp on when the ambient illuminance detected by the illuminance sensor in the power-saving mode is less than the first threshold value. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic view showing an example of a structure of an image forming apparatus. 
         FIG.  2    is a plan view showing an example of a structure of an operation device. 
         FIG.  3    is a block diagram showing an example of a circuit configuration of the image forming apparatus. 
         FIG.  4    is a flowchart showing an example of an operation of a controller. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, a description will be given of an embodiment of the present disclosure with reference to the drawings. Throughout the drawings, the same or corresponding parts are designated by the same references and further explanation thereof will be omitted. 
     Referring to  FIG.  1   , a description will be given of an image forming apparatus  100  according to an embodiment of the present disclosure.  FIG.  1    is a schematic view showing an example of a structure of the image forming apparatus  100 . The image forming apparatus  100  is, for example, a copier, a printer, a facsimile machine or a multifunction peripheral combining these functions. In this embodiment, the image forming apparatus  100  is a black-and-white multifunction peripheral. 
     As shown in  FIG.  1   , the image forming apparatus  100  includes a reading device  1 , a sheet feed device  2 , a conveyance device  3 , an image forming device  4 , a fixing device  5 , and a discharge device  6 . 
     The reading device  1  reads an image of an original document G. The reading device  1  generates image data representing the read image. The sheet feed device  2  accommodates a plurality of sheets S and feeds the sheet S to the conveyance device  3 . The sheet S is made of, for example, paper or synthetic resin. The conveyance device  3  includes a plurality of conveyance roller pairs and conveys the sheet S to the image forming device  4 . 
     The image forming device  4  electrophotographically forms a toner image on the sheet S. The image forming device  4  includes a photosensitive drum, a charging device, an exposure device, a developing device, a toner supply device, a transfer device, a cleaning device, and a destaticizing device. The image forming device  4  forms a toner image representing the image of an original document G, for example, based on the above-described image data. The fixing device  5  applies heat and pressure to the toner image to fix the toner image on the sheet S. The conveyance device  3  conveys the sheet S bearing the toner image fixed thereon to the discharge device  6 . The discharge device  6  discharges the sheet S to the outside of the image forming apparatus  100 . 
     Next, referring to  FIGS.  1  and  2   , a description will be given of a structure of an operation device  10  included in the image forming apparatus  100 .  FIG.  2    is a plan view showing an example of a structure of the operation device  10 . 
     As shown in  FIG.  2   , the operation device  10  includes a touch panel  11  and various keys. The operation device  10  includes, as various keys, a Start key  12  and a Stop key  13 . 
     The touch panel  11  is, for example, a device in which the function of an input device is added to a liquid crystal panel for use in displaying information. The Start key  12  is a key for use when a user inputs an instruction to start a job. The Stop key  13  is a key for use when the user inputs an instruction to cancel or suspend a job being executed. 
     The operation device  10  further includes a Power-Saving key  14  as one of the various keys. The Power-Saving key  14  is a key for use when the user inputs an instruction to transition from the normal mode to the power-saving mode and an instruction to return from the power-saving mode to the normal mode. The power-saving mode is a mode where the power consumption is reduced relative to the normal mode. In the power-saving mode, for example, power feeding to a heater included in the fixing device  5  is stopped. The Power-Saving key  14  functions as a first trigger for the return from the power-saving mode to the normal mode. The Power-Saving key  14  corresponds to an example of the “operating key”. 
     The Power-Saving key  14  contains a lamp  14 A. The lamp  14 A contains, for example, a light-emitting diode. The lamp  14 A turned on indicates, with light, the location of the Power-Saving key  14  on the operation device  10  to the user. 
     Next, referring to  FIGS.  1  to  3   , a description will be given of a circuit configuration of the image forming apparatus  100 .  FIG.  3    is a block diagram showing an example of a circuit configuration of the image forming apparatus  100 . 
     As shown in  FIG.  3   , the image forming apparatus  100  further includes a human detection sensor  20 , an illuminance sensor  30 , a controller  60 , and a storage device  70 . 
     The human detection sensor  20  is an infrared ray sensor that has a variable human body detection range for detecting a human body and functions as a second trigger for the return from the power-saving mode to the normal mode. The human detection sensor  20  includes a reflective sensor  21  and a pyroelectric sensor  22 . The reflective sensor  21  has a human body detection range set to a normal range (for example, a distance range of less than several tens of centimeters). The pyroelectric sensor  22  has a human body detection range set to a wide range (for example, a distance range of not less than 3 m and not more than 5 m) relative to the normal range. 
     The illuminance sensor  30  is a sensor for use in detecting the ambient illuminance of the image forming apparatus  100 . 
     The storage device  70  comprises a plurality of storage devices and stores data and computer programs. The storage device  70  includes a main storage device, such as a semiconductor memory, and an auxiliary storage device, such as a hard disk drive. 
     The controller  60  includes a processor, such as a CPU (central processing unit). By executing a control program stored in the storage device  70 , the controller  60  controls the components of the image forming apparatus  100 . Specifically, the controller  60  controls the turning on and off of the lamp  14 A according to the ambient illuminance detected by the illuminance sensor  30  in the power-saving mode. In addition, the controller  60  controls the human body detection range of the human detection sensor  20  by switching between the reflective sensor  21  and the pyroelectric sensor  22  according to the ambient illuminance detected by the illuminance sensor  30  in the power-saving mode. 
     Next, referring to  FIGS.  1  to  4   , a description will be given of an operation of the controller  60 .  FIG.  4    is a flowchart showing an example of an operation of the controller  60 . 
     Step S 101 : The controller  60  executes the setting of the normal mode as shown in  FIG.  4   . In the normal mode, for example, power is fed to the heater included in the fixing device  5 . When the processing in step S 101  is completed, the controller  60  goes to the processing in step S 103 . 
     Step S 103 : The controller  60  determines whether or not to transition to the power-saving mode. When determining that a transition to the power-saving mode should be made (Yes in step S 103 ), the controller  60  goes to the processing in step S 105 . When determining that a transition to the power-saving mode should not be made (No in step S 103 ), the controller  60  goes back to the processing in step S 101 . For example, when the Power-Saving key  14  is pressed in the normal mode, the controller  60  determines that a transition to the power-saving mode should be made. Also when a predetermined transition time has passed while no operation is made in the normal mode, the controller  60  determines that a transition to the power-saving mode should be made. In the power-saving mode, for example, the controller  60  stops power feeding to the heater included in the fixing device  5 . The power-saving mode includes a first power-saving mode and a second power-saving mode. 
     Step S 105 : The controller  60  determines whether or not the ambient illuminance is equal to or more than a threshold value. When determining that the ambient illuminance is equal to or more than the threshold value (Yes in step S 105 ), the controller  60  goes to the processing in step S 107 . When determining that the ambient illuminance is less than the threshold value (No in step S 105 ), the controller  60  goes to the processing in step S 109 . 
     Step S 107 : The controller  60  executes the setting of the first power-saving mode. In the first power-saving mode, the controller  60  controls the lamp  14 A to turn it off. Additionally, in the first power-saving mode, the controller  60  performs control to set the human body detection range of the human detection sensor  20  to the normal range by allowing the reflective sensor  21  to operate as the human detection sensor  20 . When the processing in step S 107  is completed, the controller  60  goes to the processing in step S 111 . 
     Step S 109 : The controller  60  executes the setting of the second power-saving mode. In the second power-saving mode, the controller  60  controls the lamp  14 A to turn it on. Additionally, in the second power-saving mode, the controller  60  performs control to set the human body detection range of the human detection sensor  20  to the wide range expanded relative to the normal range by allowing the pyroelectric sensor  22  to operate as the human detection sensor  20 . When the processing in step S 109  is completed, the controller  60  goes to the processing in step S 111 . When the ambient illuminance is less than the threshold value, any human body is less detectable. Therefore, the controller  60  may intermittently operate the pyroelectric sensor  22  for the sake of energy saving. 
     Step S 111 : The controller  60  determines whether or not to cancel the power-saving mode. When determining that the power-saving mode should be cancelled (Yes in step S 111 ), the controller  60  goes back to the processing in step S 101 . When determining that the power-saving mode should not be cancelled (No in step S 111 ), the controller  60  goes back to the processing in step S 105 . For example, when the Power-Saving key  14  is pressed in the power-saving mode, the controller  60  determines that the power-saving mode should be cancelled. Also when the human detection sensor  20  detects a human body in the power-saving mode, the controller  60  determines that the power-saving mode should be cancelled. 
     Meanwhile, when the surrounding area is dark at the return from the power-saving mode, the general image forming apparatus described previously has difficulty in identifying the location of the operating key, which presents a problem with operability. 
     On the contrary, in the above embodiment, when the ambient illuminance in the power-saving mode is less than the threshold value, the lamp  14 A is turned on, which increases the visibility of the Power-Saving key  14 . As a result, an image forming apparatus  100  having improved operability at the return from the power-saving mode is provided. 
     The description of the embodiment of the present disclosure has so far been given with reference to the drawings. However, the present disclosure is not limited to the above embodiment and can be implemented in various forms without departing the gist of the present disclosure. The various formations of the disclosure can be made by appropriately combining a plurality of components disclosed in the above embodiment. For example, some of all the components disclosed in the above embodiment may be deleted. For the sake of ease of understanding, the drawings are schematic representation, primarily of components. The number of components and so on shown in the drawings may be different from those of actual components for convenience of creation of the drawings. The components described in the above embodiments are merely illustrative, not particularly limited, and can be changed variously without substantially departing from the effects of the present disclosure. 
     For example, although the image forming apparatus  100  in the above embodiment is of electrophotographic printing type, the present disclosure is not limited to this embodiment. For example, the image forming apparatus  100  may be of ink-jet printing type. Although the image forming apparatus  100  in the above embodiment is a black-and-white multifunction peripheral, the present disclosure is not limited to this embodiment. For example, the image forming apparatus  100  may be a color multifunction peripheral. 
     Although in the above embodiment the operating key is the Power-Saving key  14 , the present disclosure is not limited to this embodiment. For example, the operating key may be a power key that controls the mode and also controls the turning on and off power supply. 
     Although in the above embodiment the threshold value of the illuminance in controlling the lamp is equal to that of the illuminance in controlling human body detection, the present disclosure is not limited to this embodiment. For example, the controller  60  may turn the lamp  14 A off when the ambient illuminance detected by the illuminance sensor  30  in the power-saving mode is equal to or more than a first threshold value, and the controller  60  may turn the lamp  14 A on when the ambient illuminance detected by the illuminance sensor  30  in the power-saving mode is less than the first threshold value. On the other hand, the controller  60  may set the human body detection range to the normal range when the ambient illuminance detected by the illuminance sensor  30  in the power-saving mode is equal to or more than a second threshold value, and the controller  60  may set the human body detection range to the wide range when the ambient illuminance detected by the illuminance sensor  30  in the power-saving mode is less than the second threshold value. The first and second threshold values are different from each other. 
     INDUSTRIAL APPLICABILITY 
     The present disclosure is applicable in the field of image forming apparatuses. 
     While the present disclosure has been described in detail with reference to the embodiments thereof, it would be apparent to those skilled in the art the various changes and modifications may be made therein within the scope defined by the appended claims.