Control device, electronic apparatus, control method, and program

Abstract

[Problem] To provide a control device with which it is possible to secure safety while suppressing a user's opportunity loss due to control on limits to an exterior temperature rise. [Solution] The control device is a device for controlling an electronic apparatus and includes: an acquisition unit for acquiring a duration of contact to a contact section that a user is in contact with, a material of the contact section, and a temperature of the contact section; a determination unit for determining an upper-limit temperature on the basis of the contact duration and the material; and a control unit for executing operation restriction on the electronic apparatus when the temperature is larger than the upper-limit temperature.

Description

Control device, electronic device, control method, and program

[0001] The present invention relates to a control device, an electronic device, a control method, and a program.

[0002] In recent years, as electronic devices have become more sophisticated and thinner and smaller, the temperature of their exteriors has risen, which can be uncomfortable for users or harmful to the human body. Patent Literature 1 discloses a configuration that performs power consumption reduction processing when the exterior of an imaging device reaches an uncomfortable temperature or an alert temperature just before a temperature that is harmful to the human body while the user is in contact with the imaging device.

[0003] JP 2016-82274 A

[0004] However, the configuration of Patent Document 1 does not take into account the impact on the human body due to differences in exterior surface materials or the duration of continuous contact with the exterior, and only restricts operation based on a temperature threshold. As a result, it is not possible to accurately determine whether something is actually harmful to the user, and restrictions are imposed on device operation even in situations where restrictions are not necessary, potentially resulting in a loss of opportunities for users to use the device.

[0005] The present invention can provide a control device that can ensure safety while suppressing opportunity loss for the user due to limiting control against an increase in exterior temperature.

[0006] A control device as one aspect of the present invention is a control device that controls an electronic device, and is characterized by having an acquisition unit that acquires the contact time of a contact part that a user is in contact with, the material of the contact part, and the temperature of the contact part, a determination unit that determines an upper limit temperature based on the contact time and the material, and a control unit that executes operational restrictions on the electronic device when the temperature is higher than the upper limit temperature.

[0007] According to the present invention, it is possible to provide a control device that can ensure safety while suppressing opportunity losses for users that accompany limiting control against an increase in exterior temperature.

[0008] FIG. 1 is an external view of an imaging device which is an example of an electronic device according to an embodiment of the present invention. FIG. 2 is a block diagram showing the configuration of the imaging device of this embodiment. FIG. 3 is a diagram showing the relationship between safe temperatures of this embodiment. FIG. 4 is a flowchart showing an example of temperature limit control of this embodiment. FIG. 5 is a flowchart showing another example of temperature limit control of this embodiment. FIG. 6 is a diagram showing an example in which the temperature limit control of this embodiment is applied to a head-mounted display. FIG. 7 is a diagram showing an example in which the temperature limit control of this embodiment is applied to a smartphone.

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to designate the same components, and redundant explanations will be omitted.

[0010] 1A and 1B are external views of a digital camera (image capture device) 100, which is an example of an electronic device according to an embodiment of the present invention. Fig. 1A is a view of the digital camera 100 as seen from the front, and Fig. 1B is a view of the digital camera 100 as seen from the back.

[0011] The display unit 28 is located on the back of the digital camera 100 and displays images and various information. The display unit 28 is connected to the rear exterior via a vari-angle mechanism and can be opened, closed, rotated, or otherwise adjusted from its position when stored in the display storage compartment 27 shown in FIG. 1B. For example, the display unit 28 can be deployed as shown in FIG. 1C by opening and closing it. A display open / close detection sensor 28S is located inside the display storage compartment 27 to detect the open / closed state of the display unit 28. The touch panel 70a can detect touch operations on the display surface (touch operation surface) of the display unit 28. The viewfinder display unit 43 is located on the top surface of the digital camera 100 and displays various settings of the digital camera 100, such as shutter speed and aperture. The shutter button 61 is used to issue shooting instructions. The mode switch 60 is used to switch between various modes. The terminal cover 40 protects connectors (not shown) for connecting cables and other devices to the digital camera 100.

[0012] The main electronic dial 71 is a rotary operation member. By turning the main electronic dial 71, settings such as shutter speed and aperture can be changed. The power switch 72 is used to turn the power of the digital camera 100 on and off. The sub electronic dial 73 is a rotary operation member. By turning the sub electronic dial 73, the selection frame (cursor) can be moved, images can be advanced, etc. The four-way key 74 is configured so that the up, down, left, and right parts can be pressed. By pressing the four-way key 74, processing corresponding to the part pressed can be performed. The SET button 75 is a push button, and is mainly used to confirm a selected item, etc.

[0013] The video button 76 is used to start or stop video shooting (recording). The AE lock button 77 is a push button. Pressing the AE lock button 77 in shooting standby mode fixes the exposure state. The magnify button 78 is used to switch the magnify mode ON and OFF in the live view display (LV display) of the shooting mode. By turning the magnify mode ON and operating the main electronic dial 71, the live view image (LV image) can be enlarged or reduced. In playback mode, the magnify button 78 is used to enlarge the playback image or increase the magnification ratio. The playback button 79 is used to switch between shooting mode and playback mode. Pressing the playback button 79 in shooting mode switches to playback mode, and the most recent image recorded on the recording medium 200 (described later) can be displayed on the display unit 28. The menu button 81 is used to display a menu screen. When the menu button 81 is pressed, a menu screen on the display unit 28 allows various settings to be configured. The user can intuitively make various settings using the menu screen displayed on the display unit 28, the four-way key 74, and the SET button 75.

[0014] The communication terminal 10 is used when the digital camera 100 communicates with the lens unit 150 (described later). The eyepiece finder 17 is a peer-type finder. The user can view an image displayed on an internal EVF (Electronic Viewfinder) 29 through the eyepiece 16 of the eyepiece finder 17. The eyepiece detection unit 57 detects whether the user has placed their eye on the eyepiece 16. The grip unit 90 is a holding unit shaped to be easily gripped with the user's right hand when holding the digital camera 100. When the digital camera 100 is held by gripping the grip unit 90 with the little finger, ring finger, and middle finger of the right hand, the shutter button 61 and main electronic dial 71 are positioned so that they can be operated with the index finger of the right hand. In the same state, the sub electronic dial 73 is positioned so that it can be operated with the thumb of the right hand. The thumb rest 91 is a grip member provided on the rear side of the digital camera 100 in a position where it is easy to place the thumb of the right hand when gripping the grip 90 without operating any of the operation members. The thumb rest 91 is made of a rubber member or the like to enhance holding power (grip feeling).

[0015] FIG. 2 is a block diagram showing the configuration of the digital camera 100. The lens unit 150 is configured to be detachable from the digital camera 100. The lens unit 150 includes a lens 103. The lens 103 is usually composed of multiple lenses, but FIG. 2 shows only a single lens for simplicity's sake. The communication terminal 6 is used when the lens unit 150 communicates with the digital camera 100. The lens unit 150 communicates with the system control unit 50 via the communication terminals 6 and 10. The lens system control circuit 4 controls the aperture 1 via the aperture drive circuit 2. The lens system control circuit 4 also adjusts the focus by displacing the position of the lens 103 via the AF drive circuit 3.

[0016] The shutter 101 is a focal plane shutter that can control the exposure time of the imaging unit 22 under the control of the system control unit 50 .

[0017] The imaging unit 22 is an imaging element (image sensor) configured with a CCD, CMOS element, or the like that converts an optical image into an electrical signal. The imaging unit 22 may include an imaging surface phase difference sensor that outputs defocus amount information to the system control unit 50. The A / D converter 23 converts the analog signal output from the imaging unit 22 into a digital signal.

[0018] The image processing unit 24 performs predetermined processing (pixel interpolation, resizing such as reduction, color conversion, etc.) on data from the A / D converter 23 or data from the memory control unit 15. The image processing unit 24 also performs predetermined arithmetic processing using the captured image data, and the system control unit 50 performs exposure control and focus detection control based on the arithmetic results obtained by the image processing unit 24. This allows TTL (through-the-lens) type AF (autofocus) processing, AE (autoexposure) processing, EF (pre-flash) processing, etc. to be performed. The image processing unit 24 also performs predetermined arithmetic processing using the captured image data, and TTL type AWB (auto white balance) processing based on the arithmetic results obtained.

[0019] The output data from the A / D converter 23 is written to the memory 32 via the image processing unit 24 and the memory control unit 15, or is written to the memory 32 via the memory control unit 15 without going through the image processing unit 24. The memory 32 stores image data obtained by the imaging unit 22 and converted into digital data by the A / D converter 23, as well as image data to be displayed on the display unit 28 and the EVF 29. The memory 32 has a storage capacity sufficient to store a predetermined number of still images and a predetermined period of moving images and audio.

[0020] The memory 32 also serves as a memory for image display (video memory). The D / A converter 19 converts image display data stored in the memory 32 into analog signals and supplies them to the display unit 28 or the EVF 29. As a result, the image display data written to the memory 32 is displayed on the display unit 28 or the EVF 29 via the D / A converter 19. The display unit 28 and the EVF 29 are each a display such as an LCD or an organic EL, and perform display in accordance with the analog signal from the D / A converter 19. The digital signal that has been A / D converted by the A / D converter 23 and stored in the memory 32 is converted into an analog signal by the D / A converter 19, and the analog signal is sequentially transferred to and displayed on the display unit 28 or the EVF 29, thereby enabling live view display.

[0021] The system control unit 50 is a control device that includes at least one processor and / or at least one circuit and that controls the entire digital camera 100. The system control unit 50 realizes each process of this embodiment by executing a program recorded in the nonvolatile memory 56. The system control unit 50 also performs display control by controlling the memory 32, D / A converter 19, display unit 28, EVF 29, etc.

[0022] The system memory 52 is, for example, a RAM, and the system control unit 50 loads constants and variables for the operation of the system control unit 50, as well as programs read from the nonvolatile memory 56, into the system memory 52.

[0023] The nonvolatile memory 56 is an electrically erasable and recordable memory, such as an EEPROM, etc. Constants and programs for the operation of the system control unit 50 are recorded in the nonvolatile memory 56.

[0024] The system timer 53 is a timekeeping unit that measures the time used for various controls and the time of a built-in clock.

[0025] The communication unit 54 transmits and receives video signals and audio signals to and from external devices connected wirelessly or via a wired cable. The communication unit 54 can also connect to a wireless LAN (Local Area Network) or the Internet. The communication unit 54 can also communicate with external devices via Bluetooth (registered trademark) or Bluetooth Low Energy. The communication unit 54 can transmit images (including LV images) captured by the imaging unit 22 and images recorded on the recording medium 200, and can receive image data and various other information from external devices.

[0026] The orientation detection unit 55 detects the orientation of the digital camera 100 with respect to the direction of gravity. Based on the orientation detected by the orientation detection unit 55, it is possible to determine whether an image captured by the imaging unit 22 was captured with the digital camera 100 held horizontally or vertically. The system control unit 50 can add orientation information corresponding to the orientation detected by the orientation detection unit 55 to the image file of the image captured by the imaging unit 22, or rotate and record the image. An acceleration sensor, a gyro sensor, or the like can be used as the orientation detection unit 55. The acceleration sensor or gyro sensor of the orientation detection unit 55 can also be used to detect movement of the digital camera 100 (such as panning, tilting, lifting, and whether the digital camera 100 is stationary).

[0027] The eyepiece detection unit 57 is an eyepiece detection sensor that detects (detects proximity) whether an eye (object) approaches (approaches) or moves away (away from) the eyepiece 16. The system control unit 50 switches the display unit 28 and the EVF 29 between on (display state) and off (non-display state) depending on the state detected by the eyepiece detection unit 57. Specifically, when the system is in a shooting standby state and the display destination switching setting is automatic switching, the display unit 28 is turned on as the display destination and the EVF 29 is turned off when the eye is not in contact with the subject. Furthermore, when the eye is in contact with the subject, the display unit 28 is turned on as the display destination and the display unit 28 is turned off. The eyepiece detection unit 57 can be, for example, an infrared proximity sensor, which can detect the approach of an object to the eyepiece 16 incorporating the EVF 29. When an object approaches, infrared light emitted from a light-emitting unit (not shown) of the eyepiece detection unit 57 is reflected by the object and received by a light-receiving unit (not shown) of the infrared proximity sensor. The amount of received infrared light can also determine the distance an object is approaching the eyepiece 16 (eyepiece distance). In this way, the eyepiece detection unit 57 performs eyepiece detection, detecting the proximity of an object to the eyepiece 16. When an object approaching within a predetermined distance from the eyepiece 16 is detected from a non-eyepiece state (non-approach state), it is detected as being in eye contact. When an object detected as being close moves away from the eyepiece state (approach state) by a predetermined distance or more, it is detected as being disengaged. The threshold for detecting eye contact and the threshold for detecting disengagement may be different, for example, by providing hysteresis. Furthermore, after detecting eye contact, the eye is considered to be in the eye contact state until disengagement is detected. After detecting disengagement, the eye is considered to be in the non-eye contact state until contact is detected. The infrared proximity sensor is merely an example, and other sensors capable of detecting a state that can be considered as being in eye contact may be used for the eyepiece detection unit 57.

[0028] The temperature detection unit 119 is configured with a temperature detection means (second detection means) 119s, such as a thermistor, for detecting the exterior temperature of the digital camera 100. The temperature detection means 119s is not limited to one type, and may be arranged near one or more exteriors.

[0029] The contact detection unit 120 is configured with a contact detection means (first detection means) 120s for detecting whether or not the user is touching the exterior of the digital camera 100. The contact detection means 120s is, for example, a pressure sensor, an optical proximity sensor, or a capacitance sensor, but is not limited to one type, and may be arranged near one or more exteriors.

[0030] The contact time detection unit 121 detects the continuous contact time (contact time) that the user is continuously contacting the exterior of the digital camera 100. The contact time detection means (third detection means) 121s constituting the contact time detection unit 121 may be a pressure sensor, an optical proximity sensor, a capacitance sensor, or the like, similar to the contact detection means 120s, but is not limited to one type and may be arranged near one or more of the exteriors. Furthermore, the contact time detection means 121s and the contact detection means 120s may be a single detection means or different detection means. The system control unit 50 may be configured to acquire the contact time using information from the contact detection unit 120.

[0031] Various settings of the digital camera 100 such as shutter speed and aperture are displayed on the outside viewfinder display section 43 via an outside viewfinder display section drive circuit 44 .

[0032] The power supply control unit 80 is composed of a battery detection circuit, a DC-DC converter, a switch circuit for switching between powered blocks, and other components, and detects whether a battery is installed, the type of battery, and the remaining battery charge. The power supply control unit 80 also controls the DC-DC converter based on the detection results and instructions from the system control unit 50, and supplies the required voltage for the required period to each component, including the recording medium 200. The power supply unit 30 is composed of a primary battery such as an alkaline battery or a lithium battery, a secondary battery such as a NiCd battery, a NiMH battery, or a Li battery, or an AC adapter, etc.

[0033] The recording medium I / F 18 is an interface with a recording medium 200 such as a memory card or a hard disk. The recording medium 200 is a recording medium such as a memory card for recording captured images, and is composed of a semiconductor memory, a magnetic disk, or the like.

[0034] The operation unit 70 is an input unit that accepts operations from the user (user operations) and is used to input various operational instructions to the system control unit 50. The operation unit 70 includes a shutter button 61, a mode selector switch 60, a power switch 72, a touch panel 70a, and other operation members 70b. The other operation members 70b include a main electronic dial 71, a sub electronic dial 73, a four-way key 74, a SET button 75, a video button 76, an AE lock button 77, a magnification button 78, a playback button 79, a menu button 81, etc.

[0035] The shutter button 61 includes a first shutter switch 62 and a second shutter switch 64. The first shutter switch 62 is turned on when the shutter button 61 is pressed halfway (a shooting preparation instruction) during operation, and generates a first shutter switch signal SW1. The system control unit 50 starts shooting preparation operations such as AF processing, AE processing, AWB processing, and EF processing in response to the first shutter switch signal SW1.

[0036] The second shutter switch 64 is turned ON when the shutter button 61 is fully pressed (photographing instruction) and generates a second shutter switch signal SW2. The second shutter switch signal SW2 causes the system control unit 50 to start a series of photographing processing operations, from reading out a signal from the imaging unit 22 to writing the captured image to the recording medium 200 as an image file.

[0037] The mode selector switch 60 is used to switch the operating mode of the system control unit 50 between a still image capture mode, a video capture mode, and a playback mode. Modes included in the still image capture mode include an auto capture mode, an auto scene determination mode, a manual mode, an aperture priority mode (Av mode), a shutter speed priority mode (Tv mode), and a program AE mode (P mode). There are also various scene modes and custom modes that provide capture settings for specific capture scenes. Using the mode selector switch 60, the user can directly switch to one of these modes. Alternatively, after switching to a list screen of capture modes using the mode selector switch 60, the user may selectively switch to one of the displayed modes using another operating member. Similarly, the video capture mode may also include multiple modes.

[0038] The touch panel 70a is a touch sensor that detects various touch operations on the display surface of the display unit 28 (the operation surface of the touch panel 70a). The touch panel 70a and the display unit 28 can be configured as an integrated unit. For example, the touch panel 70a is configured so that its light transmittance does not interfere with the display of the display unit 28, and is attached to the upper layer of the display surface of the display unit 28. Input coordinates on the touch panel 70a are associated with display coordinates on the display surface of the display unit 28. This makes it possible to provide a GUI (graphical user interface) that allows the user to directly operate the screen displayed on the display unit 28.

[0039] The system control unit 50 can detect the following operations on the touch panel 70a or the state of the touch panel 70a.

[0040] - A finger or pen that was not touching the touch panel 70a now touches the touch panel 70a, i.e., the start of touching (hereinafter referred to as Touch-Down). - A state in which the touch panel 70a is touched with a finger or pen (hereinafter referred to as Touch-On). - A finger or pen moves while still touching the touch panel 70a (hereinafter referred to as Touch-Move). - A finger or pen that was touching the touch panel 70a is released from the touch panel 70a, i.e., the end of touching (hereinafter referred to as Touch-Up). - A state in which nothing is touching the touch panel 70a (hereinafter referred to as Touch-Off). When Touch-Down is detected, Touch-On is also detected at the same time. After Touch-Down, Touch-On normally continues to be detected unless Touch-Up is detected. When Touch-Move is detected, Touch-On is also detected at the same time. Even if Touch On is detected, Touch Move will not be detected unless the touch position moves. After it is detected that all fingers or pens that were touching have touched up, Touch Off will occur.

[0041] These operations and states, as well as the position coordinates of the finger or pen touching the touch panel 70a, are notified to the system control unit 50 via the internal bus. The system control unit 50 determines what type of operation (touch operation) was performed on the touch panel 70a based on the notified information. Regarding touch-move, the movement direction of the finger or pen moving on the touch panel 70a can also be determined for each vertical and horizontal component on the touch panel 70a based on changes in the position coordinates. If a touch-move of a predetermined distance or more is detected, it is determined that a slide operation has been performed. An operation in which a finger is touched on the touch panel 70a, moved quickly for a certain distance, and then released is called a flick. In other words, a flick is an operation in which a finger is quickly traced across the touch panel 70a as if flicking it. If a touch-move of a predetermined distance or more at a predetermined speed or more is detected and a touch-up is then detected, it is determined that a flick has been performed (it is determined that a flick occurred following a slide operation). Furthermore, a touch operation in which multiple points (e.g., two points) are touched together (multi-touch) and the touch positions are brought closer together is called a pinch in, and a touch operation in which the touch positions are moved farther apart is called a pinch out. Pinch out and pinch in are collectively called a pinch operation (or simply a pinch). The touch panel 70a may be any of a variety of touch panel types, including resistive film type, capacitive type, surface acoustic wave type, infrared type, electromagnetic induction type, image recognition type, and optical sensor type. There are types that detect a touch by contact with the touch panel, and types that detect a touch by the approach of a finger or pen to the touch panel, and either type is acceptable.

[0042] Below, we will explain temperature limit control using the temperature detection unit 119, contact detection unit 120, and contact time detection unit 121. Generally, assuming that the temperature of a material is constant, contact with a material with high thermal conductivity can transfer more thermal energy to another substance than contact with a material with low thermal conductivity, posing a greater risk to the human body. Furthermore, the continuous contact time is a variable that determines the total amount of thermal energy transferred to the human body, and is therefore an important parameter in indicators of the degree of risk to the human body. These concepts are also clearly stated in thermal safety standards (IEC 62368-1, etc.).

[0043] FIG. 3 is a diagram showing the safe temperature relationship of this embodiment, showing the maximum temperature limit of the digital camera 100's exterior and the continuous contact time, which is the duration for which a user can contact the exterior from a safety perspective. FIG. 3(a) shows the safe temperature relationship 300a for a given exterior material. Here, Ta1, Ta2, and Ta3 respectively represent exterior temperatures, with the relationship between the three being Ta1 > Ta2 > Ta3. Furthermore, t1, t2, and t3 respectively represent the user's continuous contact time with the exterior, with the relationship between the three being t1 < t2 < t3. For example, when the exterior temperature is Ta2, the user's continuous contact time is t2. Continuous contact for a time exceeding t2 is harmful to the user's body, potentially resulting in physical injury such as burns. In other words, for safety reasons, if the exterior temperature is Ta2, the user should not continue continuous contact for a time longer than t2. In this embodiment, if the continuous contact time is t2, the temperature of the exterior surface must not exceed Ta2. Hereinafter, the temperature corresponding to the exterior temperature Ta2 in this embodiment will be referred to as the upper limit temperature Tm during the continuous contact time t2.

[0044] FIG. 3(b) shows a safety temperature relationship 300b for a different exterior material than that shown in FIG. 3(a). In this embodiment, the thermal conductivity λa of the exterior material Ma shown in the safety temperature relationship 300a is greater than the thermal conductivity λb of the exterior material Mb shown in the safety temperature relationship 300b. In this embodiment, the exterior material Ma is a metal such as a magnesium alloy, and has a thermal conductivity of approximately 50 to 70 W / mK. The exterior material Mb is a resin or rubber material such as PC or NBR, and has a thermal conductivity of approximately 0.1 to 0.5 W / mK. As with the exterior material Ma, the exterior temperatures Tb1, Tb2, and Tb3 of the exterior material Mb indicate the upper limit temperatures Tm corresponding to t1, t2, and t3, respectively, and the relationship Tb1 > Tb2 > Tb3 holds.

[0045] Figure 3(c) plots the safety temperature relationships 300a and 300b simultaneously, showing the safety temperature relationship 300ab. As shown in Figure 3(c), when the continuous contact times t1, t2, and t3 are all the same, the relationships are Ta1 < Tb1, Ta2 < Tb2, and Ta3 < Tb3. When continuous contact is performed for the same duration, the metal exterior surface poses a greater risk to the human body than the plastic exterior surface, so the upper limit temperature must also be lower. In this embodiment, the exterior materials are classified into two types: exterior material Ma and exterior material Mb. However, the number of types may be three or more, or the entire exterior may be made of a single material. While each safety temperature relationship diagram is expressed as a graph, the relationship between contact time and upper limit temperature may be calculated using a function specific to each material, or several combinations of contact time and upper limit temperature may be recorded in a table.

[0046] The temperature limit control method executed by the system control unit 50 will be described below with reference to Fig. 4. Fig. 4 is a flowchart showing the temperature limit control.

[0047] In step S401, the system control unit 50 determines whether the contact detection unit 120s has detected a user's contact with the exterior of the digital camera 100. If the system control unit 50 determines that contact has been detected, it executes the processing of step S402;

[0048] In step S402, the system control unit 50 identifies (acquires) the contact exterior (contact portion) P that the user is touching, based on information about the position where the contact detection unit 120s is mounted.

[0049] In step S403, the system control unit 50 determines (obtains) the exterior material M of the contact exterior P. The digital camera 100 is assumed to have information about the exterior material M of each exterior in advance.

[0050] In step S404, the system control unit 50 acquires the continuous contact time t with the contact exterior P from the contact time detection unit 121s.

[0051] In step S405, the system control unit 50 refers to the safe temperature relationship 300 corresponding to the exterior material M and determines the upper limit temperature Tm for the current continuous contact time t using the continuous contact time t.

[0052] In step S406, the system control unit 50 acquires the actual contact temperature T of the contact exterior P from the temperature detection means 119s.

[0053] In step S407, the system control unit 50 determines whether the upper limit temperature Tm determined in step S405 is lower than the contact temperature T acquired in step S406. If the system control unit 50 determines that the upper limit temperature Tm is lower than the contact temperature T, it executes the process of step S408;

[0054] In step S408, the system control unit 50 restricts the functions of the digital camera 100 to protect the safety of the user. The restriction on the functions of the digital camera 100 may be a restriction on the recording function, including the resolution and frame rate, a restriction on the function of the shutter button 61, a power saving process such as a forced power shutdown, or simply a warning display on the display unit 28 or the EVF 29.

[0055] A safety margin may be provided for the upper limit temperature Tm. For example, the temperature margin may be determined by referring to the value of the detection error of the temperature detection means 119s.

[0056] In this embodiment, the system control unit 50 also functions as an acquisition unit that acquires the continuous contact time t, the exterior material M, and the contact temperature T. The system control unit 50 also functions as a determination unit that determines the upper limit temperature Tm. Furthermore, the system control unit 50 also functions as a control unit that restricts the functions of the digital camera 100 when the upper limit temperature Tm is lower than the contact temperature T.

[0057] Desirable mounting positions of the temperature detecting means 119s, the contact detecting means 120s, and the contact time detecting means 121s, as well as the detecting means, will be described below with reference to FIGS.

[0058] Grip section 90 is shaped to be held by the user when using digital camera 100, and is the part of the exterior that the user will be in contact with the most of the time. For this reason, it is desirable to provide various detection means for detecting the contact state and temperature of grip section 90.

[0059] Due to the structure of the digital camera 100, the imaging unit 22 is often located on the front side of the interior, while a circuit board including the system control unit 50 is located on the back side. The system control unit 50 consumes particularly large amounts of power within the digital camera 100 and therefore generates a large amount of heat, making the display housing 27, which is the exterior component, prone to high temperatures. Therefore, to ensure safety in the event of user contact, it is desirable to subject it to temperature limit control and provide various detection means to detect the contact state and temperature of the display housing 27. It is desirable to use an optical proximity sensor for at least one of the contact detection means 120s and contact time detection means 121s of the display housing 27. By using an optical proximity sensor arranged to detect the exterior surface of the display housing 27, it is possible to detect the open / closed state of the display 28 in addition to the user's contact state. This makes it possible to eliminate the conventional display open / close detection sensor 28S. Furthermore, when detecting contact and temperature of the display housing 27, it is desirable to switch the detection ON / OFF depending on the open / closed state of the display 28, regardless of the detection means. Specifically, it is desirable to turn on the contact and temperature detection when it is detected that the display unit 28 is not housed in the display unit housing 27, and to turn off the contact and temperature detection when the display unit 28 is housed in the display unit housing 27 because the user cannot touch the display unit housing 27. This allows the power consumption of the digital camera 100 to be reduced.

[0060] The strap attachment portion 301 is provided to support the digital camera 100 and lens unit 150 when the strap is in use. Because high durability is required, it is often made of a metal material. One example of a material for the strap attachment portion 301 is zinc die-cast. However, this material has a very high thermal conductivity of approximately 100 W / mK, posing a high risk to the human body when the temperature rises. Furthermore, metal materials in general, not just zinc die-cast, have high thermal conductivity. Therefore, it is desirable to provide various detection means to detect the contact state and temperature of the strap attachment portion 301. It is also desirable to use a capacitance sensor for at least one of the contact detection means 120s and contact time detection means 121s of the strap attachment portion 301. Due to the structure of the strap attachment portion 301, applying a pressure sensor or optical proximity sensor requires the respective sensors to be located on the exterior surface. On the other hand, a capacitance sensor can detect contact by locating the detection unit inside the digital camera 100, incorporating the strap attachment portion 301 as a detection circuit, and configuring it to detect the capacitance of the strap attachment portion 301 itself. This eliminates the need to place a sensor on the exterior surface, reducing the risk of sensor failure due to impact, etc., and also making it possible to avoid false detection due to pressure detection, etc., when using a strap. When a capacitance sensor is used for at least one of the contact detection means 120s and the contact time detection means 121s, it is desirable to set a detection threshold that detects the capacitance of the human body while not detecting objects other than the human body (gloves, etc.).

[0061] The temperature detection unit 119s does not necessarily have to be mounted in close proximity to the contact detection unit 120s or the contact time detection unit 121s, for example, on the same board. Also, it is not necessary to directly detect the temperature of the exterior, and it is possible to predict the temperature of a specific exterior by understanding in advance the correlation between the temperature of the exterior and the temperature at the mounting position of the temperature detection unit 119s.

[0062] Below, a method of temperature limit control different from the flow shown in Fig. 4 will be described. Fig. 5 is a flowchart showing another example of temperature limit control. In the following description, the contact detection means 120s and the contact time detection means 121s are considered to be the same detection means, and will be collectively referred to as the contact detection means 120s.

[0063] In step S501, the system control unit 50 determines whether the contact detection unit 120s has detected a user's contact with the exterior of the digital camera 100. If the system control unit 50 determines that contact has been detected, it executes the process of step S502, and if it determines that contact has not been detected, it executes the process of step S509.

[0064] In step S502, the system control unit 50 acquires the continuous contact time t. At this time, by acquiring the current continuous contact time t by adding the time for one sampling to the continuous contact time t at the previous sampling, it is possible to perform both contact detection and continuous contact time detection using only the contact detection unit 120s.

[0065] The processes in steps S503 to S508 are similar to the processes in steps S402, S403, and S405 to S408 in FIG. 4, respectively, and therefore will not be described further.

[0066] In step S509, the system control unit 50 acquires the continuous non-contact time I by performing the same calculation as for the continuous contact time t. The continuous non-contact time I is the antonym of the continuous contact time t, and is the duration during which the user does not touch the exterior of the digital camera 100 (the time from when it is detected that the user is not touching the exterior to when it is detected that the user is touching the exterior).

[0067] In step S510, the system control unit 50 determines whether the continuous non-contact time I is shorter than a reset margin time (predetermined time) R. The reset margin time R is the amount of time from the last contact detection until the continuous contact time t is reset. That is, if no contact is made in the sampling period following the last contact detection, the continuous contact is interrupted, and the continuous contact time t becomes 0. However, the continuous contact time t is not reset until the reset margin time R has elapsed since the last contact detection. That is, if the continuous non-contact time I is shorter than the reset margin time R, the continuous contact time t is not reset. If the system control unit 50 determines that the continuous non-contact time I is shorter than the reset margin time R, it executes the process of step S511. If it determines that the continuous non-contact time I is not shorter than the reset margin time R, it executes the process of step S512.

[0068] In step S511, the system control unit 50 adds the continuous non-contact time I to the continuous contact time t. By controlling in this manner, even if a user action occurs in which continuous contact is not made for a very short period of time, such as when re-gripping the grip portion 90, continuous contact can be maintained as the contact determination, and a harmful contact state can be avoided.

[0069] In step S512, the system control unit 50 determines that the non-contact state has continued sufficiently and the risk has been reduced, and resets the continuous contact time t.

[0070] Hereinafter, a description will be given of a method of temperature limit control that is different from the flow charts of Figures 4 and 5. Figure 6 is a flowchart showing another example of temperature limit control.

[0071] The process of step S601 is the same as the process of step S401 in FIG. 4, and therefore a description thereof will be omitted.

[0072] The process of step S602 is the same as the process of step S502 in FIG. 5, and therefore a description thereof will be omitted.

[0073] The processes in steps S603 to S606 are similar to the processes in steps S402, S403, S405, and S406 in FIG. 4, respectively, and therefore will not be described further.

[0074] In step S607, the system control unit 50 determines whether the contact temperature T is lower than the contact temperature T0 (previous contact temperature) acquired during the previous sampling. If the system control unit 50 determines that the contact temperature T is lower than the previous contact temperature T0, i.e., if the temperature has decreased over time, it executes the process of step S608. If the system control unit 50 determines that the contact temperature T is not lower than the previous contact temperature T0, i.e., if the temperature has increased over time, it executes the process of step S609.

[0075] If the temperature has decreased (been decreasing) over time, this means that contact has continued from a temperature higher than the current contact temperature T, and therefore the risk of personal injury such as burns is higher than if contact continued at the current contact temperature T. Therefore, in step S608, the system control unit 50 sets the current contact temperature to the previous contact temperature T0 (the current contact temperature is not updated).

[0076] If the temperature rises over time, it is expected that the continuous contact time will gradually decrease during continuous gripping. Therefore, in step S609, the system control unit 50 sets the current contact temperature to the contact temperature T acquired in step S606 (updates the current contact temperature).

[0077] In step S609, the final contact temperature T is recorded as the previous contact temperature T0 so that it can be used for the next sampling.

[0078] The processes in steps S610 and S611 are similar to those in steps S407 and S408 in FIG. 4, respectively, and therefore will not be described further.

[0079] As described above, even if the exterior temperature changes over time, the digital camera 100 can be controlled so that the user can always use it within a safe temperature range. In the flow of FIG. 6 , whether or not to update the current contact temperature is determined by comparing the contact temperature T with the previous contact temperature T0 in step S607. However, whether or not to update the current contact temperature may be determined based on the state of the digital camera 100. For example, when the image capture unit 22 captures an image, heat is generated, which promotes a rise in the temperature of the exterior of the digital camera 100. Therefore, while it is determined that the image capture unit 22 is performing an image capture operation, the contact temperature T acquired in step S606 is used in the determination in step S610. On the other hand, when the image capture unit 22 is not performing an image capture operation, the temperature of the exterior is assumed to decrease, and the current contact temperature is set to the previous contact temperature T0.

[0080] Below, with reference to Figures 7 and 8, we will explain modifications in which the temperature limit control of this embodiment is applied to various digital devices. In the following explanation, the temperature detection unit 119s, the contact detection unit 120s, and the contact time detection unit 121s will be collectively referred to as the detection unit. However, as mentioned above, the contact detection unit 120s and the contact time detection unit 121s may be a single detection unit or may be different detection units. Furthermore, the temperature detection unit 119s does not necessarily have to be mounted in close proximity to the contact detection unit 120s or the contact time detection unit 121s, for example, on the same board, and it does not necessarily have to directly detect the temperature of the exterior.

[0081] FIG. 7 is a diagram illustrating an example in which the temperature restriction control of this embodiment is applied to a head-mounted display 700. The head-mounted display 700 includes a first detector 701 and a second detector 702. For example, as shown in FIG. 7B , the user holds the head-mounted display 700. Because the head-mounted display 700 includes a face contact area 703 that is continuously in contact with the face, it may be designed to dissipate heat from the heat source to an exterior other than the face contact area 703. Therefore, by arranging the first detector 701 and the second detector 702, it is possible to restrict operation against dangerous temperatures even when the user continuously holds the exterior, which is the target of concentrated heat dissipation. On the other hand, when the user does not touch the exterior, control is possible to avoid unnecessary operation restrictions, thereby preventing usability from being impaired. The first detector 701 and the second detector 702 may be positioned symmetrically when viewed from the front, taking into account factors such as dominant hand.

[0082] FIG. 8 illustrates an example in which the temperature limit control of this embodiment is applied to a smartphone. The smartphone 710 includes a first detection unit 711, a second detection unit 712, a touch panel 713, and an exterior cover 714. The amount of heat generated by smartphones 710 tends to increase as they become more multifunctional, more sophisticated, and have improved imaging performance. Furthermore, when a user uses the smartphone 710, the smartphone may be held in their hand or placed on a desk or tripod without being touched. Furthermore, the expected contact points on the exterior of the smartphone 710 are almost all parts of the exterior, and the materials used vary depending on the location, such as the touch panel 713 being made of glass and the exterior cover 714 being made of resin. Conventionally, operation restrictions are implemented through contact detection, but the temperature limit is not adjusted based on the exterior material being touched, nor is control based on the duration of continuous contact. As a result, there is a risk that the user may unnecessarily impose operation restrictions even when the temperature is within a safe range.

[0083] By applying the temperature limit control of this embodiment, operation can be limited to an appropriate dangerous temperature according to the user's contact state by detecting the user's contact state and determining the limit temperature based on the thermal conductivity of the exterior material in contact and the duration of continuous contact. On the other hand, by not restricting operation when the user does not continuously contact the exterior, or by determining the limit temperature based on the thermal conductivity of the exterior material in contact, operation can be restricted without unnecessary restrictions, thereby preventing usability from being impaired. Furthermore, input from the touch panel 713 may be used as at least one of the contact detection means 120s and the contact time detection means 121s, rather than being limited to the first detection unit 711 and the second detection unit 712. A detection unit may also be provided on the rear exterior of the smartphone 710. [Other Embodiments] The present invention can also be realized by providing a program implementing one or more of the functions of the above-described embodiments to a system or device via a network or a storage medium, and having one or more processors in the computer of the system or device read and execute the program. The present invention can also be realized by a circuit (e.g., an ASIC) implementing one or more functions.

[0084] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist of the present invention.

Claims

1. A control device for controlling an electronic device, comprising: an acquisition unit that acquires the contact time of a contact part that a user is in contact with, the material of the contact part, and the temperature of the contact part; a determination unit that determines an upper limit temperature based on the contact time and the material; and a control unit that imposes operational restrictions on the electronic device when the temperature is higher than the upper limit temperature.

2. The electronic device according to claim 1, wherein the determination unit determines the upper limit temperature using data indicating the relationship between the contact time and the upper limit temperature for each material.

3. A control device as described in claim 1 or 2, characterized in that if the time from the time it is detected that the user is not touching the contact portion to the time it is detected that the user is touching the contact portion is shorter than a predetermined time, measurement of the contact time continues.

4. A control device according to any one of claims 1 to 3, characterized in that if the temperature decreases, the temperature is not updated, and if the temperature increases, the temperature is updated.

5. An electronic device comprising: a control device according to any one of claims 1 to 4; a first detection means for detecting contact with the contact portion by the user; and a second detection means for detecting the temperature of the contact portion.

6. The electronic device according to claim 5, further comprising a third detection means for detecting the contact time.

7. The electronic device according to claim 6, wherein the first detection means and the third detection means are the same means.

8. The electronic device according to claim 6 or 7, wherein at least one of the first detection means and the third detection means is a pressure sensor.

9. The electronic device according to claim 6 or 7, wherein at least one of the first detecting means and the third detecting means is an optical proximity sensor.

10. The electronic device according to claim 6 or 7, wherein at least one of the first detecting means and the third detecting means is a capacitance sensor.

11. The electronic device according to any one of claims 6 to 10, characterized in that the electronic device is an imaging device having an imaging unit, and the temperature is updated when the imaging unit is performing an imaging operation, and the temperature is not updated when the imaging unit is not performing an imaging operation.

12. The electronic device according to claim 11, wherein the electronic device is an imaging device having an imaging section, and the contact section is a grip section.

13. The electronic device according to claim 11 or 12, characterized in that the electronic device is an imaging device having an imaging section, and the contact section is a display section housing section.

14. The electronic device according to any one of claims 11 to 13, characterized in that the electronic device is an imaging device having an imaging section, and the contact section is a strap attachment section.

15. A control method for controlling an electronic device, comprising the steps of: acquiring the contact time of a contact part that a user is in contact with, the material of the contact part, and the temperature of the contact part; determining an upper limit temperature based on the contact time and the material; and executing an operational restriction on the electronic device if the temperature is higher than the upper limit temperature.

16. A program for causing a computer to execute the control method according to claim 15.

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