Patent Publication Number: US-10313586-B2

Title: Electronic apparatus, method for controlling the same, and storage medium

Description:
BACKGROUND 
     Field 
     The present disclosure relates to an electronic apparatus, a method for controlling the same, and a storage medium. 
     Description of the Related Art 
     Some electronic apparatuses equipped with a display device detect proximity of a user based on detection information from a human detection sensor, such as a proximity detection unit built into the apparatuses, and control the display device based on the detected proximity. 
     For example, recent digital cameras include a liquid crystal monitor on their rear portion in addition to an electronic viewfinder (EVF) and are configured to be able to use both the EVF and the liquid crystal monitor to check composition of objects. Such a configuration usually enables image display of either the EVF or liquid crystal monitor in view of reduction in power consumption. In other words, if the user views through a viewing window of the EVF, the image display on the EVF is enabled and liquid crystal monitor&#39;s image display is turned off. If the viewing window of the EVF is not closed and external light is incident thereon, the image display on the EVF is turned off and the liquid crystal monitor&#39;s image display is enabled. For such a control, a proximity sensor for detecting proximity of an object, e.g., the photographer&#39;s face, to the viewing window of the EVF is arranged on or near the viewing window. 
     Japanese Patent Application Laid-Open No. 2008-252526 discusses a television set that turns on its power if a light detection unit and a human detection unit determine that lighting is on and a person is present in the vicinity of the television set. 
     Japanese Patent Application Laid-Open No. 2001-339627 discusses an imaging apparatus using an EVF. The imaging apparatus turns on power to the imaging apparatus&#39;s display device if a proximity sensor detects that the EVF is being viewed through. The EVF can thus be powered off to reduce power consumption in situations where a display image of the EVF is not viewed by a user. 
     In general, display devices need a plurality of types of positive and negative voltages to drive their display elements. To reduce power consumption, the generation of such driving voltages can be stopped during periods in which no user is needed. It takes some time for a boosting or step-down operation for generating a driving voltage to complete and for the driving voltage to stabilize. An image display of a display device is typically enabled after stabilization of the driving voltages. Even if the proximity of a user is detected by a proximity detection unit, it can be difficult to immediately provide stable display on the display device. 
     The proximity detection unit can erroneously detect proximity and perform control on the display device even if the user is not operating the electronic apparatus. If the user walks with an electronic apparatus, such as an imaging apparatus, around the user&#39;s neck, the imaging apparatus swings and the back of the imaging apparatus can come into contact with and move away from the user&#39;s abdomen. If the back of the imaging apparatus comes into contact with or approaches the user&#39;s abdomen, the proximity detection unit detects the proximity. If the back of the imaging apparatus moves away from the user&#39;s abdomen, the proximity detection unit does not detect proximity. In other words, when the user walks with an electronic apparatus that detects proximity of a human body and controls a display device based on the detected proximity, the user&#39;s motion can result in the electronic apparatus can repeatedly switch from detecting proximity to not detecting proximity. This causes the display device to repeatedly drive (turn-on) and stop (turn-off), resulting in unnecessary power consumption. 
     SUMMARY OF THE INVENTION 
     The present disclosure is directed to an electronic apparatus that more suitably performs processing based on proximity detection and a method for controlling the electronic apparatus. 
     According to an aspect of the embodiments, an electronic apparatus includes a motion detection unit configured to detect a motion of the electronic apparatus, a proximity detection unit configured to detect proximity of an object, a display unit configured to be viewable when view through an eyepiece part, and a control unit configured to, in a case where proximity detection information from the proximity detection unit corresponds to a distance closer than a threshold, perform control to start display on the display unit, and configured to, in a case where the motion detection unit detects a first motion, change the threshold to a value corresponding to a greater distance. 
     According to another aspect of the embodiments, an electronic apparatus includes a motion detection unit configured to detect a motion of the electronic apparatus, a proximity detection unit configured to detect proximity of an object, a display unit configured to be viewable when viewed through an eyepiece part, and a control unit configured to, in a case where proximity detection information from the proximity detection unit corresponds to a distance closer than a threshold, perform control to start display on the display unit, and configured to, in a case where the motion detection unit detects a second motion, stop a detection operation of the proximity detection unit or stop the control of the display on the display unit based on a detection result from the proximity detection unit. 
     Further features will become apparent from the following description of exemplary embodiments with reference to the attached drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a rear view of an exemplary embodiment. 
         FIG. 2  is a schematic block diagram of the exemplary embodiment. 
         FIG. 3  is a schematic block diagram of a proximity detection unit. 
         FIG. 4A  is an operation flowchart according to the exemplary embodiment. 
         FIG. 4B  is an operation flowchart according to the exemplary embodiment. 
         FIGS. 5A, 5B, 5C, and 5D  are state transition diagrams according to the exemplary embodiment. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     An exemplary embodiment will be described in detail below with reference to the drawings. 
       FIG. 1  is a rear view of an imaging apparatus that is an exemplary embodiment of the electronic apparatus.  FIG. 2  is a schematic block diagram illustrating a configuration of the imaging apparatus. 
     An imaging apparatus  10  illustrated in  FIGS. 1 and 2  includes a camera main body  12  and a lens unit  14  that is detachable from the camera main body  12 . 
     The lens unit  14  includes a lens  16 , a diaphragm  18 , and a lens control unit  20 . The lens control unit  20  controls the lens  16  and the diaphragm  18  based on a control signal from a system control unit  30  of the camera main body  12 . The lens unit  14  is fixed to the camera main body  12  by mechanically coupling a mount  22  of the lens unit  14  with a mount  72  of the camera main body  12 . With the lens unit  14  fixed to the camera main body  12 , a connector  24  of the lens unit  14  is electrically connected to a connector  74  of the camera main body  12 . The lens control unit  20  communicates with the system control unit  30  via the connectors  74  and  24 . 
     The lens control unit  20  controls the entire lens unit  14 . The lens control unit  20  includes a built-in memory that stores constants, variables, and programs for operation. The lens control unit  20  also includes a nonvolatile memory that stores identification information such as a number unit to the lens unit  14 , management information, functional information such as a maximum aperture value, a minimum aperture value, and a focal length, and past and present setting values. The lens control unit  20  includes an automatic focusing (AF) function of changing an image forming position of an object image incident on an image sensor  42  by controlling focusing of the lens  16  based on a focusing state measured by an image processing unit  44 . The lens control unit  20  also includes a function of controlling the aperture value of the diaphragm  18  and the zooming of the lens  16 . 
     A configuration of the camera main body  12  will now be described. The system control unit  30  includes a central processing unit (CPU) that controls the entire imaging apparatus  10  using a system memory  32 . An electrically erasable and recordable nonvolatile memory  34  stores setting values, an imaging mode, and various types of correction data. Examples of the setting values include various parameters and an International Organization for Standardization (ISO) speed. The nonvolatile memory  34  also stores a computer program that runs on the system control unit  30 . 
     An operation unit  36  is an operation unit for inputting various types of predetermined operation instructions into the system control unit  30 . The operation unit  36  includes any one of a switch, a dial, a touch panel, a line of sight detection pointing device, or a voice recognition device, or any combination of thereof. 
     A power switch  38  is used to power on/off the imaging apparatus  10  and to make mode switch settings. 
     A power supply unit  40  includes a battery, a battery detection unit, a current detection unit, a protection circuit, a direct-current-to-direct-current (DCDC) converter, and a low dropout (LDO) regulator. The power supply unit  40  supplies desired power supply voltages generated by the DCDC converter to the components of the imaging apparatus  10  for desired periods based on instructions from the system control unit  30 . The power supply unit  40  detects the presence or absence of an attached battery, and the type and remaining level of the battery. When an overcurrent is detected, the power supply unit  40  cuts off the voltage outputs to protect load circuits. 
     The image sensor  42  is a sensor for converting an optical image formed by the lens unit  14  and incident on its imaging plane into an image signal. The image processing unit  44  performs predetermined calculation processing on the image signal output from the image sensor  42 , and applies pixel processing based on the calculation result to generate video data of a predetermined video signal format. Examples of the pixel processing include pixel interpolation processing, color conversion processing, and white balance processing. The image processing unit  44  temporarily stores the generated video data in a memory  46 . The image processing unit  44  includes a Joint Photographic Experts Group (JPEG) image compression function. 
     A recording circuit  48  is a circuit for recording the video data temporarily stored in the memory  46  on a removable recording medium, such as a semiconductor memory, and reproducing video data from the recording medium. 
     The system control unit  30  determines the aperture value of the diaphragm  18  and shutter speed of a shutter  50  based on exposure information from the image processing unit  44 . The system control unit  30  controls the shutter  50  to the determined shutter speed via a shutter control unit  52 , and controls the diaphragm  18  to the determined aperture value via the lens control unit  20 . The system control unit  30  controls image display of the video data temporarily stored in the memory  46  on a display  54  and an EVF  56 . 
     As illustrated in  FIG. 1 , the display  54  size can occupy a large area on the back of the camera main body  12 . The EVF  56  is a display unit arranged in a viewing window located above the display  54 . A screen of the EVF  56  is viewed by viewing through the viewing window. An output lens window  70   a  and a light receiving lens window  70   b  of a proximity detection unit  70  are arranged directly below the viewing window. The proximity detection unit  70  detects a state of proximity or a degree of the same up to a view-through state in which the user (photographer) presses an eye against the viewing window. 
     The display  54  includes an organic electroluminescent (EL) display or a liquid crystal display. For example, the display  54  includes a liquid crystal display that includes a transmissive liquid crystal panel of a thin film transistor active matrix driving method. Each display element of the liquid crystal panel includes red, green, and blue (RGB), three sub pixels including color filters of the three colors RGB arranged on top of liquid crystals. Polarization filters for suppressing the oscillation directions of light to one direction are arranged on bottom of the liquid crystals and on top of the color filters. A display driving unit  58  adjusts voltages applied to the respective sub pixels, whereby the transmittance of light emitted from a backlight  60  can be adjusted to display a desired image in gradations. 
     If a self-luminescence display such as an organic EL display is employed as the display  54 , the backlight  60  is not needed. 
     The display driving unit  58  supplies a driving timing signal for driving the display  54 . The display driving unit  58  includes a built-in boosting unit and step-down unit for generating driving voltages of the display elements of the display  54 . The display driving unit  58  applies the generated driving voltages to the display  54  in synchronization with the driving timing signal. 
     An illumination luminance control unit  62  can adjust the illumination luminance of the backlight  60  stepwise. The illumination luminance control unit  62  linearly changes the illumination luminance by limiting the amount of current applied to the light emitter of the backlight  60  based on a pulse width moderation (PWM) control signal from the system control unit  30 . The backlight  60  includes a light source such as a light-emitting diode (LED), a fluorescent tube, and an organic EL element, and a light guide plate, a reflection plate, and a diffusion plate for implementing plane emission of light output from the light source. The backlight  60  is fixed to a rear surface of the display  54  and projects light on the rear surface of the display  54 . 
     A touch panel  64  is arranged on a top surface of the display  54 . Examples of a touch detection method of the touch panel  64  include a resistive method, a capacitive method, and an optical method. The present exemplary embodiment can use any of these methods. 
     The EVF  56  includes a flat display, such as an organic EL display, and a liquid crystal display. As illustrated in  FIG. 1 , the EVF  56  is arranged inside the viewing window in an upper portion of the rear surface of the camera main body  12 . 
     The organic EL display of the EVF  56  includes a built-in organic EL panel of the thin film transistor active matrix driving method. Each display element of the organic EL panel includes R, G, and B, three organic EL elements. The organic EL elements emit light when a voltage is applied thereto. Driving voltages applied from an EVF driving unit  66  to the respective organic EL elements can be adjusted to control the amounts of light in the respective colors and display a desired image in gradations. 
     The EVF driving unit  66  supplies a driving timing signal for driving the EVF  56  to the EVF  56 . The EVF driving unit  66  includes a built-in boosting unit and step-down unit for generating the driving voltages of the EVF  56 . The EVF driving unit  66  applies the generated driving voltages to the EVF  56  in synchronization with the driving timing signal. 
     The system control unit  30  can display a menu screen, an image, and live view display on both the display and the EVF  56 . The system control unit  30  independently controls display on the display  54  and that of the EVF  56  on/off based on operations from the operation unit  36 . The system control unit  30  controls display switching between the display  54  and the EVF  56  based on a detection result from a proximity detection unit  70 . 
     An orientation detection unit  68  detects orientation of the camera main body  12  with respect to the direction of gravity. Based on the orientation detected by the orientation detection unit  68 , the system control unit  30  determines in what orientation of the camera main body  12  a captured image is captured. The system control unit adds direction information based on the orientation detected by the orientation detection unit  68  to an image file of the captured image, and, if needed, rotates and records the captured image in a specified direction. The orientation detection unit  68  includes an acceleration sensor. 
     The proximity detection unit  70  is arranged below the EVF  56 . The proximity detection unit  70  detects a state of proximity or a degree of the same (proximity distance) up to a view-through state in which the user presses an eye against the viewing window. If the system control unit  30  obtains proximity detection information from the proximity detection unit  70 , the system control unit  30  performs display switching to stop display on the display  54  and enable display on the EVF  56 . 
     The proximity detection unit  70  includes, for example, an infrared emission element and a light receiving circuit. The proximity detection unit  70  emits infrared rays at regular intervals and measures the amount of reflected light to detect the presence or absence of an object in a predetermined position. The proximity detection unit  70  externally emits output infrared rays (probe light) from the infrared emission element through an output lens window  70   a  ( FIG. 1 ), and receives reflected light of the probe light from the object, e.g., the photographer, through a light receiving lens window  70   b  ( FIG. 1 ). The proximity detection unit  70  can detect a distance between the camera main body  12  and the photographer with a plurality of levels of detection thresholds. 
       FIG. 3  illustrates a schematic block diagram of the proximity detection unit  70 . An external interface  302  of the proximity detection unit  70  is connected to the system control unit  30 . The system control unit  30  controls the proximity detection unit  70  and receives a proximity detection result from the proximity detection unit  70 . 
     A light emission element control unit  304  can drive an infrared emission element  306  and increase and decrease its driving current. If the driving current increases, a light emission intensity of the infrared emission element  306  increases. Output light of the infrared emission element  306  is externally emitted via the output lens window  70   a.    
     The light radiated from the output lens window  70   a  is reflected by an object  320 . The reflected light is collected through the light receiving lens window  70   b  and incident on a light receiving element  308 . An amplifier unit  310  amplifies an output electrical signal of the light receiving element  308 . An analog-to-digital (A/D) conversion unit  312  converts an analog output signal of the amplifier unit  310  into a digital signal. 
     A logic control unit  314  controls turn-on/off timing of the infrared emission element  306 , and generates an accumulation/reset timing signal of the light receiving element  308 . The logic control unit  314  determines the proximity distance or the degree of proximity by comparing an output value of the A/D conversion unit  312  with the plurality of detection thresholds. The logic control unit  314  can change the detection threshold between the plurality of levels. The logic control unit  314  notifies the system control unit  30  of a proximity determination result via the external interface  302 . 
     The object  320  is basically a part of the face or body of the user of the imaging apparatus  10 , i.e., the photographer. The proximity detection unit  70  detects proximity of any object that reflects the light radiated from the output lens window  70   a.    
       FIGS. 4A and 4B  are flowcharts illustrating an imaging operation according to the present exemplary embodiment. A program for implementing the processing illustrated in  FIGS. 4A and 4B  is stored in the nonvolatile memory  34 . The system control unit  30  reads and loads the program from the nonvolatile memory  34  into the system memory  32 , and executes the program. The system control unit  30  thereby implements the processing illustrated in  FIGS. 4A and 4B . If the user turns on the power switch  38 , the imaging apparatus  10  is activated and the system control unit  30  starts the processing illustrated in  FIGS. 4A and 4B . 
     In step S 401 , the system control unit  30  activates the orientation detection unit  68  and the proximity detection unit  70 , and starts an operation of the orientation detection unit  68  and the proximity detection unit  70 . The system control unit  30  starts display on the display  54 . For example, the system control unit  30  displays a live view image captured by the image sensor  42  and various types of setting information. The system control unit  30  starts a timer for measuring non-operation time. 
     In step S 402 , the system control unit  30  obtains an orientation detection output from the orientation detection unit  68  and performs orientation detection calculation processing. By the orientation detection calculation processing, the system control unit  30  determines whether the user is making a walking motion or an eyepiece imaging preparation motion. If the user is making a walking motion, orientation information obtained from the orientation detection unit  68  oscillates based on the movement of the user&#39;s feet. The orientation information then shows periodic, almost constant changes in acceleration in the vertical and horizontal directions. If the user is making an eyepiece imaging preparation motion, as illustrated in  FIGS. 5A, 5B, 5C, and 5D , the user quickly moves the imaging apparatus  10  for eyepiece imaging from an on-hand operation state or live view imaging state. As a result, the orientation information includes a large change in acceleration in the vertical or horizontal direction. The system control unit  30  can determine the user motion based on such a difference. For example, if a change or movement greater than or equal to a predetermined amount of change in the vertical or horizontal direction is observed, the system control unit  30  determines that the user is making an eyepiece imaging preparation motion. 
     In step S 403 , the system control unit  30  determines whether the determination result in step S 402  indicates a walking motion. If the determination result indicates a walking motion (YES in step S 403 ), the processing proceeds to step S 404 . If not (NO in step S 403 ), the processing proceeds to step S 419 . 
     In step S 404 , the system control unit  30  stops a detection operation of the proximity detection unit  70 . The detection operation of the proximity detection unit  70  can be stopped to avoid erroneous detection of the proximity detection unit  70  while the user is walking. 
     In step S 405 , the system control unit  30  changes time (a threshold of time) before the imaging apparatus  10  enters a power saving mode (power saving mode shift time) from an initial value T 0  to a shorter predetermined time T 1 . For example, if the initial value T 0  of the time before the imaging apparatus  10  enters the power saving mode is  60  seconds, the system control unit  30  sets the predetermined time T 1  to shorter time, e.g., 30 seconds. The power saving mode refers to a state in which an operation of some of the functions of the imaging apparatus  10  is stopped. In the power saving mode, standby power of the imaging apparatus  10  can be reduced, compared to a normal operation mode. For example, in the power saving mode, the system control unit  30  hides the display on the display  54  and turns off the backlight  60 . Other examples of the power saving mode can include a mode in which the emission intensity of the backlight  60  is reduced to reduce display luminance of display  54 , and a mode in which the driving of the touch panel  64  is stopped. By such a control, the imaging apparatus  10  can enter the power saving mode of low power consumption early if the imaging apparatus  10  is not in use, like when the user is holding the imaging apparatus  10  while walking or imaging apparatus  10  is hanging from the user&#39;s neck while the user is walking. 
     In step S 406 , the system control unit  30  obtains the orientation detection output from the orientation detection unit  68  and performs orientation detection calculation processing. The orientation detection calculation processing is calculation processing for determining whether the user is making preparations for eyepiece imaging in which an eye is brought close to the EVF  56 . Here, a situation such that the user looks for an object during walking, finds one, and then makes an eyepiece imaging preparation motion is assumed. 
     In step S 407 , the system control unit  30  determines, based on a calculation result of step S 406 , whether an eyepiece imaging preparation motion is detected. If an eyepiece imaging preparation motion is determined to be detected (YES in step S 407 ), the processing proceeds to step S 408 . In step S 408 , the system control unit  30  changes the power saving mode shift time from T 1  back to the initial value T 0  before change. In step S 409 , the system control unit  30  resumes the detection operation of the proximity detection unit  70 . The processing then proceeds to step S 420 . 
     In step S 407 , if the user is not making an eyepiece imaging preparation motion (NO in step S 407 ), the processing proceeds to step S 410 . In step S 410 , the system control unit  30  determines whether there is an input from the operation unit  36 . If there is an input from the operation unit  36  (YES in step S 410 ), the processing proceeds to step S 411 . If there is no input from the operation unit  36  (NO in step S 410 ), the processing proceeds to step S 412 . 
     In step S 411 , the system control unit  30  executes processing based on the operation. The system control unit  30  changes the power saving mode shift time back to the initial value T 0 , and resets and resumes measurement of the non-operation time. If the operation of the proximity detection unit  70  has stopped, the system control unit  30  resumes the detection operation of the proximity detection unit  70 . Examples of the processing based on the operation include processing for changing an imaging setting and imaging processing. After step S 411 , the processing proceeds to step S 417 . 
     In step S 412 , the system control unit  30  determines whether the non-operation time has reached T 1 . If the non-operation time has not reached T 1  (NO in step S 412 ), the processing returns to step S 406 . The system control unit  30  then repeats step S 406  and subsequent steps. If the non-operation time has reached T 1  (YES in step S 412 ), the processing proceeds to step S 413 . 
     In step S 413 , the system control unit  30  changes the power saving mode shift time from T 1  back to the initial value T 0 . In step S 414 , the system control unit  30  changes the operation mode from the normal operation mode to the power saving mode. This reduces the power consumption of the imaging apparatus  10 . The system control unit  30  can stop the operation of the orientation detection unit  68  and the proximity detection unit  70 . 
     In step S 415 , the system control unit  30  determines whether the operation unit  36  is operated. If the operation unit  36  is not operated (NO in step S 415 ), the processing returns to step S 415 , whereby the system control unit  30  waits for an operation input from the operation unit  36 . If there is an operation input from the operation unit  36  (YES in step S 415 ), the processing proceeds to step S 416 . 
     In step S 416 , the system control unit  30  cancels the power saving mode and enters the normal operation mode. The processing then proceeds to step S 417 . If the operation of the orientation detection unit  68  and the proximity detection unit  70  has been stopped, the system control unit  30  resumes the operation of the orientation detection unit  68  and the proximity detection unit  70 . The system control unit  30  resets and resumes the measurement of the non-operation time. 
     In step S 419 , the system control unit  30  determines whether an eyepiece imaging preparation motion is detected. If an eyepiece imaging preparation motion is not detected (NO in step S 419 ), the processing proceeds to step S 438 . If an eyepiece imaging preparation motion is detected (YES in step S 419 ), the processing proceeds to step S 420 . 
     In step S 438 , the system control unit  30  determines whether proximity is detected by the proximity detection unit  70 . The system control unit  30  determines whether an object is closer than a proximity distance threshold TH 1 . If proximity is detected, i.e., the object is determined to be closer than the proximity distance threshold TH 1  (YES in step S 438 ), the processing proceeds to step S 423 . If not (NO in step S 438 ), the processing proceeds to step S 417 . 
     In step S 420 , the system control unit  30  changes the proximity distance threshold of the proximity detection unit  70  from TH 1  to TH 2 , which is greater than TH 1 . The purpose is to switch display from the display  54  to the EVF  56  earlier when shifting to eyepiece imaging. The system control unit  30  starts to measure an elapsed time from the eyepiece imaging preparation motion. Determining whether the object is in proximity can be based on the use of something other than the proximity distance itself as a threshold like TH 1  and TH 2 . For example, determining whether the object is in proximity can be based on using thresholds set with respect to the amount of light received by the light receiving element  308 . In other words, the thresholds can be the proximity distance thresholds TH 1  and TH 2 , the received amount of light of the light receiving element  308 , or other elements as long as the thresholds correspond to large and small proximity distances. 
     In step S 421 , the system control unit  30  determines whether the distance detected by the proximity detection unit  70  is closer than the proximity distance threshold, e.g., TH 2 . If the object is closer than the proximity distance threshold TH 2  (YES in step S 421 ), the processing proceeds to step S 422 . If not (NO in step S 421 ), the processing proceeds to step S 440 . In step S 440 , the system control unit  30  determines whether the elapsed time from the eyepiece imaging preparation motion has reached T 2 . T 2  is a threshold of time estimated to be typically needed from when an eye piece imaging preparation motion is made to when the viewing window is viewed through. For example, T 2  is set to approximately 1 second. If the elapsed time from the eyepiece imaging preparation motion has reached T 2  (YES in step S 440 ), i.e., if proximity is not detected within T 2 , the processing proceeds to step S 441 . If not (NO in step S 440 ), the processing returns to step S 421 . 
     In step S 441 , the system control unit  30  changes the proximity distance threshold of the proximity detection unit  70  back to the initial value TH 1 . The processing then proceeds to step S 417 . If proximity is not detected by the proximity detection unit  70  within T 2  from the eyepiece imaging preparation motion, the motion detected in step S 419  may not be the motion for making preparations for eyepiece imaging. The system control unit  30  then changes the proximity distance threshold back to the initial value TH 1 . 
     In step S 422 , the system control unit  30  changes the proximity distance threshold of the proximity detection unit  70  back to the initial value TH 1 . In step S 423 , the system control unit  30  switches display from the display  54  to the EVF  56 . More specifically, the system control unit  30  hides display on the display  54  and drives the EVF  56  for display. For example, the EVF  56  displays a live view image captured by the image sensor  42  and various types of setting information. 
     In step S 424 , the system control unit  30  obtains orientation detection information output from the orientation detection unit  68 , and performs calculation processing for determining whether the user is making a walking motion. In step S 425 , the system control unit  30  determines whether a walking motion is detected from the calculation result of step S 424 . If a walking motion is detected (YES in step S 425 ), the processing proceeds to step S 426 . If no walking motion is detected (NO in step S 425 ), the processing proceeds to step S 439 . 
     In step S 439 , the system control unit  30  determines, based on the detection output of the proximity detection unit  70 , whether the user withdraws the user&#39;s eye from the EVF  56 . In step S 439 , if withdrawal of the user&#39;s eye is detected (YES in step S 439 ), the processing proceeds to step S 432 . If withdrawal of the user&#39;s eye is not detected (NO in step S 439 ), the processing returns to step S 424 . In step S 424 , the system control unit  30  determines again whether the user is making a walking motion. To detect withdrawal of the user&#39;s eye in step S 439 , the proximity detection unit  70  detects that the object changes from the state of being in proximity to a state of not being in proximity. The user&#39;s eye can be determined to be withdrawn if the object is separated from the proximity detection unit  70  by more than the same proximity distance threshold TH 1  as that during proximity detection. The user&#39;s eye can be determined to be withdrawn if the object is separated by a distance having hysteresis with respect to the proximity distance threshold TH 1 . 
     In step S 426 , the system control unit  30  stops the detection operation of the proximity detection unit  70 . In step S 427 , the system control unit  30  changes the threshold of the power saving mode shift time of the imaging apparatus  10  from the initial value T 0  to the shorter value T 1 . 
     In step S 428 , the system control unit  30  determines an input operation from the operation unit  36 . If there is an input from the operation unit  36  (YES in step S 428 ), the processing proceeds to step S 429 . Here, a situation in which the user walks during eyepiece imaging is assumed. If there is no input from the operation unit  36  (NO in step S 428 ), the processing proceeds to step S 433 . Here, a situation is presumed in which the user walks with the imaging apparatus  10  not in use, i.e., around the user&#39;s neck. 
     In step S 429 , the system control unit  30  changes the threshold of the power saving mode shift time back to the initial value T 0 , and resets and resumes the measurement of the non-operation time. The system control unit  30  also executes processing based on the input operation from the operation unit  36  (for example, processing for changing an imaging setting and imaging processing). In step S 430 , the system control unit  30  resumes the operation of the proximity detection unit  70 . 
     In step S 431 , the system control unit  30  waits until the user&#39;s eye is detected to be withdrawn based on the proximity detection output of the proximity detection unit  70 . In step S 431 , if the user&#39;s eye is detected to be withdrawn (YES in step S 431 ), the processing proceeds to step S 432 . 
     In step S 432 , the system control unit  30  switches display from the EVF  56  to the display  54 . More specifically, the system control unit  30  stops driving and hides the display on the EVF  56 , and drives the display  54  into a displayable state. For example, the display  54  displays a live view image captured by the image sensor  42  and various types of setting information. 
     In step S 428 , if there is no input operation from the operation unit  36  (NO in step S 428 ), the processing proceeds to step S 433 . In step S 433 , the system control unit  30  determines whether the non-operation time has reached T 1 . If the non-operation time has not reached T 1  (NO in step S 433 ), the processing returns to step S 428 . If the non-operation time has reached T 1  (YES in step S 433 ), the processing proceeds to step S 434 . 
     In step S 434 , the system control unit  30  changes the threshold of the power saving mode shift time from T 1  back to the initial value T 0 . In step S 435 , the system control unit  30  changes the operation mode from the normal operation mode to the power saving mode. In step S 436 , the system control unit  30  waits for an input from the operation unit  36 . If there is an input from the operation unit  36  (YES in step S 436 ), the processing proceeds to step S 437 . In step S 437 , the system control unit  30  cancels the power saving mode and enters the normal operation mode. If the operation of the orientation detection unit  68  and the proximity detection unit  70  has been stopped, the system control unit  30  resumes the operation of the orientation detection unit  68  and the proximity detection unit  70 . The system control unit  30  also resets and resumes the measurement of the non-operation time. 
     In step S 417 , the system control unit  30  determines whether the power switch  38  is turned off. If the power switch  38  is not turned off (NO in step S 417 ), the processing returns to step S 402 . The system control unit  30  then performs step S 402  and subsequent steps again. If the power switch  38  is turned off (YES in step S 417 ), the system control unit  30  turns off the power of the camera main body  12 . 
       FIGS. 5A, 5B, 5C, and 5D  are schematic diagrams illustrating a relationship between state transitions among an initial state before eyepiece imaging, detection of a swing-up motion, detection of a drawing motion, and thresholds. 
     In the initial state before eyepiece imaging, as illustrated in  FIG. 5A , an on-hand operation or live view imaging is assumed. When shifting from an on-hand operation state illustrated in  FIG. 5A  to eyepiece imaging, the user makes a swing-up motion as illustrated in  FIG. 5B . A large change in acceleration in a vertically upward direction is observed as an eyepiece imaging preparation motion. When shifting from a live view imaging state to eyepiece imaging, the user makes a drawing motion as illustrated in  FIG. 5C . A large change in acceleration in a horizontally approaching direction is observed as an eyepiece imaging preparation motion. 
     During the motions illustrated in  FIGS. 5B and 5C , if the orientation detection unit  68  detects the eyepiece imaging preparation motion, the proximity distance threshold of the proximity detection unit  70  is changed from the initial value TH 1  to the greater TH 2  value. Proximity can thus be detected earlier than if the proximity distance threshold is kept at the threshold TH 1 . If proximity is not detected within the predetermined time T 2  in the state illustrated in  FIG. 5B or 5C , the detection is assumed to be erroneous and the state is restored to the initial state illustrated in  FIG. 5A . If proximity is detected within the time T 2 , display is switched to the EVF  56 . This can reduce the display switching time. If proximity is detected within the time T 2  in the state illustrated in  FIG. 5B or 5C , the state is switched to a state illustrated in  FIG. 5D  (display by the EVF  56 ). 
     If the orientation detection unit  68  detects a walking motion in step S 403  or S 425 , the system control unit  30  stops the detection operation of the proximity detection unit  70 . This can avoid erroneous detection of the proximity detection unit  70  during a walking motion. Searching between detection and non-detection of proximity by the proximity detection unit  70  due to the swinging of the camera main body  12  in a walking motion can be prevented, and thus, frequent switching of display between the EVF  56  and the display  54  can be prevented. If a walking motion is detected, the power saving mode shift time can be changed to reduce the power consumption when the imaging apparatus  10  is not in use. 
     The proximity detection operation of the proximity detection unit  70  does not need to be stopped if a walking motion is detected. Instead, the switching of display (driving) and hiding (driving stopped) of the EVF  56  and the display  54  based on the detection result can be disabled. 
     In the present exemplary embodiment, if the user makes an eyepiece imaging preparation motion, the proximity distance threshold of the proximity detection unit  70  can be changed to reduce the switching time of display from the display  54  to the EVF  56 . 
     When the user makes a walking motion, the detection operation of the proximity detection unit  70  can be stopped and the power saving mode shift time can be changed to reduce the power consumption when the imaging apparatus  10  is not in use. 
     The present exemplary embodiment has been described by using the imaging apparatus  10  including two display units, the EVF  56  and the display  54  as an example. However, an exemplary embodiment can be applied to any electronic apparatus that includes at least one display unit. 
     The proximity detection unit  70  is described to use the infrared projection and reception-based proximity detection method. However, the proximity detection unit  70  can use capacitive and other methods. The orientation detection unit  68  is described to use an acceleration sensor. However, sensors of other detection methods, such a gyro sensor, can be used. 
     The present invention is not limited to an imaging apparatus. An exemplary embodiment is applicable to any electronic apparatus including a display unit or units that perform similar control. 
     The above-described various types of controls performed by the system control unit  30  can be performed by a single piece of hardware. A plurality of pieces of hardware can share processing to control the entire imaging apparatus. 
     In the above-described exemplary embodiment, the threshold of proximity detection is described to be changed based on orientation. In more general terms, the threshold of proximity detection can be changed based on a motion of the camera main body  12  or a degree thereof. In such a case, the orientation detection unit can be read as a motion detection unit. 
     The above-described exemplary embodiment is not seen to be limiting, and various modes not departing from the essence of the exemplary embodiment are applicable. The above-described exemplary embodiment is just one exemplary embodiment, and various exemplary embodiments can be combined as appropriate. 
     The above-described exemplary embodiment discusses an example where an imaging apparatus includes two display units. However, an exemplary embodiment is applicable to any electronic apparatus that includes a display unit or display units and controls display on the display unit(s) based on proximity. More specifically, an exemplary embodiment is applicable to a personal computer, a personal digital assistant (PDA), a mobile phone terminal, a portable image viewer, a printer, a digital photo frame, a music player, a game machine, an electronic book reader, a tablet terminal, a smartphone, and a projection apparatus. 
     According to an exemplary embodiment, display can be appropriately controlled based on proximity detection. 
     Other Embodiments 
     Embodiment(s) can also be realized by a computer of a system or apparatus that reads out and executes computer executable instructions (e.g., one or more programs) recorded on a storage medium (which may also be referred to more fully as a ‘non-transitory computer-readable storage medium’) to perform the functions of one or more of the above-described embodiment(s) and/or that includes one or more circuits (e.g., application specific integrated circuit (ASIC)) for performing the functions of one or more of the above-described embodiment(s), and by a method performed by the computer of the system or apparatus by, for example, reading out and executing the computer executable instructions from the storage medium to perform the functions of one or more of the above-described embodiment(s) and/or controlling the one or more circuits to perform the functions of one or more of the above-described embodiment(s). The computer may comprise one or more processors (e.g., central processing unit (CPU), micro processing unit (MPU)) and may include a network of separate computers or separate processors to read out and execute the computer executable instructions. The computer executable instructions may be provided to the computer, for example, from a network or the storage medium. The storage medium may include, for example, one or more of a hard disk, a random-access memory (RAM), a read only memory (ROM), a storage of distributed computing systems, an optical disk (such as a compact disc (CD), digital versatile disc (DVD), or Blu-ray Disc (BD)™), a flash memory device, a memory card, and the like. 
     While exemplary embodiments have been described, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions. 
     This application claims the benefit of Japanese Patent Application No. 2016-109669, filed Jun. 1, 2016, which is hereby incorporated by reference herein in its entirety.