JP2013238928A - Electronic device and power saving setting control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve an electronic device and a power saving setting control method for achieving power saving under the consideration of the convenience of a user.SOLUTION: An electronic device includes a power saving function. The electronic device includes: state switching means; user image generation means; stress degree calculation means; and timer setting means. While the electronic device is put in a normal operation state, the state switching means switches the electronic device to a power saving state after the lapse of a first time with any operation to the electronic device undetected. In response to the electronic device being switched to the power saving state, the user image generation means images a user, and generates the image of the user. The stress degree calculation means calculates the degree of stress corresponding to the face image included in the image. The timer setting means changes the first time on the basis of the degree of stress.

Description

  Embodiments described herein relate generally to an electronic device having a power saving function and a power saving setting control method applied to the device.

  In recent years, various electronic devices having a power saving function have been developed. Such an electronic device is configured such that a user can set parameters for power saving. This parameter indicates, for example, the time until the electronic device is set to the power saving state. For example, a personal computer (PC) is provided with a utility program for setting parameters for power saving. The user can set the time until the display is turned off, for example, using this utility program. In that case, the power of the display is turned off after the set time has passed without any user operation, and the power consumption is reduced.

  By the way, various techniques for recognizing a user's facial expression have been proposed. With this technology, for example, a slide show is displayed according to the facial expression of the viewer, and an image including a face with a predetermined facial expression is extracted from a plurality of images.

JP 2008-141484 A JP 2009-20416 A JP 2010-21819 A

  When controlled by the above-described power saving function, the electronic device may shift to a power saving state at a timing not intended by the user. For example, when a predetermined time elapses while the user is browsing the document displayed on the display without any operation, the display is turned off even though the user is browsing the document. there is a possibility. Therefore, it is expected that power can be saved while considering convenience for the user.

  It is an object of the present invention to provide an electronic device and a power saving setting control method that can save power while considering user convenience.

  According to the embodiment, the electronic device has a power saving function. The electronic device includes a state switching unit, a user image generation unit, a stress level calculation unit, and a timer setting unit. The state switching unit switches the electronic device to a power saving state when a first time elapses without detecting an operation on the electronic device while the electronic device is in a normal operation state. The user image generation means generates an image of the user by imaging the user in response to the electronic device being switched to the power saving state. The stress level calculation means calculates a stress level corresponding to the face image included in the image. The timer setting means changes the first time based on the stress level.

FIG. 2 is a perspective view illustrating an appearance of the electronic apparatus according to the embodiment. 2 is an exemplary block diagram showing the system configuration of the electronic apparatus of the embodiment. FIG. 2 is an exemplary block diagram illustrating a functional configuration of a power saving management program executed by the electronic apparatus of the embodiment. FIG. The conceptual diagram for demonstrating the stress level of the user calculated by the electronic device of the embodiment. 3 is an exemplary view showing a configuration example of an expression database used by the electronic apparatus of the embodiment. FIG. 6 is an exemplary flowchart illustrating an example of a procedure of state switching processing executed by the electronic apparatus of the embodiment. 6 is an exemplary flowchart illustrating an example of a procedure of power saving setting management processing which is executed by the electronic apparatus of the embodiment. 6 is an exemplary flowchart illustrating an example of a procedure of stress analysis processing executed by the electronic apparatus of the embodiment.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a diagram illustrating an external appearance of an electronic apparatus according to an embodiment of the present invention. This electronic apparatus is realized as a notebook type personal computer 10, for example.

  As shown in FIG. 1, the computer 10 includes a computer main body 11 and a display unit 12. The display unit 12 includes a display device including a liquid crystal display (LCD) 17. The display unit 12 is attached to the computer main body 11 so as to be rotatable between an open position where the upper surface of the computer main body 11 is exposed and a closed position covering the upper surface of the computer main body 11. The display unit 12 further includes a camera module 115 above the LCD 17. The camera module 115 is used for photographing a user or the like who uses the computer 10 when the display unit 12 is in an open position exposing the upper surface of the computer main body 11.

  The computer main body 11 has a thin box-shaped casing. On the upper surface of the computer main body 11, a keyboard 13, a power button 14 for powering on / off the computer 10, an input operation panel 15, a touch pad 16, Speakers 18A, 18B, etc. are arranged. Various operation buttons are provided on the input operation panel 15.

  Further, on the right side surface of the computer main body 11, for example, a universal serial bus (USB) 2.0 standard USB cable or a USB connector 19 for connecting a USB device is provided. The above-described camera module 115 may be an external camera (for example, a USB-connected web camera) connected via the USB connector 19.

  FIG. 2 is a diagram showing a system configuration of the computer 10.

  As shown in FIG. 2, the computer 10 includes a CPU 101, a north bridge 102, a main memory 103, a south bridge 104, a GPU (Graphics Processing Unit) 105, a VRAM (video RAM: random access memory) 105A, a sound controller 106, BIOS-ROM (basic input / output system-read only memory) 107, local area network (LAN) controller 108, hard disk drive (HDD) 109, optical disk drive (ODD) 110, USB controller 111, wireless LAN controller 112, embedded controller / Keyboard controller (EC / KBC) 113, EEPROM (electrically erasable programmable ROM) 114, camera module 115, etc.

  The CPU 101 is a processor that controls the operation of the computer 10, and executes various application programs such as an operating system (OS) 201 and a power saving management program 202 that are loaded from the HDD 109 to the main memory 103. The OS 201 has a power saving function for setting the computer 10 to one of a normal operation state that operates with normal power consumption and a power saving state that operates with lower power consumption than normal. The OS 201 indicates, for example, that the user has not operated the computer 10 within a period during which the computer 10 is in a normal operation state, and that a threshold period (first time) has elapsed (for example, a timer set with the first time). The computer 10 is switched from the normal operation state to the power saving state. In addition, for example, the OS 201 switches the computer 10 from the power saving state to the normal operation state in response to the detection of the user's operation on the computer 10 within the period in which the computer 10 is in the power saving state.

  The power saving management program 202 has a function of managing a first time (timer) used by the OS 201 for switching the computer 10 from the normal operation state to the power saving state. The power saving management program 202 changes the first time based on, for example, the degree of stress perceived by the user when the computer 10 is switched from the normal operation state to the power saving state (hereinafter also referred to as the stress degree). To do.

  The CPU 101 also executes the BIOS stored in the BIOS-ROM 107. The BIOS is a program for hardware control.

  The north bridge 102 is a bridge device that connects the local bus of the CPU 101 and the south bridge 104. The north bridge 102 also includes a memory controller that controls access to the main memory 103. The north bridge 102 also has a function of executing communication with the GPU 105 via a PCI EXPRESS standard serial bus or the like.

  The GPU 105 is a display controller that controls the LCD 17 used as a display monitor of the computer 10. A display signal generated by the GPU 105 is sent to the LCD 17.

  The south bridge 104 controls each device on a peripheral component interconnect (PCI) bus and each device on a low pin count (LPC) bus. Further, the south bridge 104 includes an IDE (Integrated Drive Electronics) controller for controlling the HDD 109 and the ODD 110. Further, the south bridge 104 has a function of executing communication with the sound controller 106.

  The sound controller 106 is a sound source device and outputs audio data to be reproduced to the speakers 18A and 18B.

  The LAN controller 108 is a wired communication device that executes IEEE 802.3 standard wired communication, for example, while the wireless LAN controller 112 is a wireless communication device that executes IEEE 802.11g standard wireless communication, for example. In addition, the USB controller 111 executes communication with an external device (connected via the USB connector 19) that supports, for example, the USB 2.0 standard. For example, communication is performed when a digital image captured by a web camera that is an external device is captured and stored in the HDD 109.

  The camera module 115 executes imaging processing using a camera. For example, the camera module 115 generates image data using an image captured by the camera, and executes communication when the image data is stored in the main memory 103 or the HDD 109. The camera module 115 supplies image data to various application programs such as the power saving management program 202. The camera module 115 has a function of executing imaging and a function of turning on / off the power in accordance with control by various application programs such as the OS 201 and the power saving management program 202.

  The EC / KBC 113 is a one-chip microcomputer in which an embedded controller for power management and a keyboard controller for controlling the keyboard 13 and the touch pad 16 are integrated. The EC / KBC 113 has a function of turning on / off the computer 10 in accordance with the operation of the power button 14 by the user.

  Next, a functional configuration of the power saving management program 202 operating on the computer 10 and a functional configuration related to the power saving function of the OS 201 that cooperates with the power saving management program 202 will be described with reference to FIG.

First, the configuration of the OS 201 will be described.
The OS 201 has a power saving function, and sets the computer 10 to one of a normal operation state that operates with normal power consumption and a power saving state that operates with lower power consumption than normal. This power saving state is not only the standby state (sleep state) of the computer 10, but also the state where the brightness of the display 17 connected to the computer 10 is lowered, the state where the display 17 is turned off, and the speakers 18A and 18B are powered This includes a state in which each component in the computer 10 and each device connected to the computer 10 operate with lower power consumption than usual, such as a turned off state. The OS 201 includes a timer 31, a state switching unit 32, a switching notification unit 33, and an operation detection unit 34.

  The timer 31 measures the elapsed time (elapsed time when there is no operation) when the user does not operate the computer 10 while the computer 10 is in the normal operation state. The timer 31 notifies the switching notification unit 33 and the state switching unit 32 that the timer 31 has expired when the measured elapsed time of no operation exceeds the first time.

  In response to the expiration notification of the timer 31, the switching notification unit 33 notifies the power saving management program 202 (switching detection unit 411) that the computer 10 is switched from the normal operation state to the power saving state. Then, the state switching unit 32 switches the computer 10 from the normal operation state to the power saving state in response to the expiration notification of the timer 31.

  The operation detection unit 34 detects an operation on the computer 10 by the user. The operation detection unit 34 detects, for example, an operation by a user using a pointing device such as the keyboard 13 or the touch pad 16, an operation of connecting an external device such as a USB flash memory or a printer to the computer 10, and the like.

  The operation detection unit 34 notifies the state switching unit 32 that an operation has been detected when an operation on the computer 10 by the user is detected while the computer 10 is in the power saving state. The state switching unit 32 switches the computer 10 from the power saving state to the normal operation state in response to the notification from the operation detection unit 34.

  Further, when the operation detection unit 34 detects an operation on the computer 10 by the user while the computer 10 is in a normal operation state, the operation detection unit 34 notifies the timer 31 that the operation has been detected. In response to the notification from the operation detection unit 34, the timer 31 resets the elapsed time for no operation during measurement.

Next, the configuration of the power saving management program 202 will be described.
The power saving management program 202 controls a first time for switching the computer 10 from the normal operation state to the power saving state, which is set in the timer 31 according to the stress level perceived by the user. For example, the power saving management program 202 reduces the user's stress level by setting the first time longer when the user's stress level is high, and sets the first time shorter when the user's stress level is low. As a result, the power saving effect can be enhanced.

  The power saving management program 202 includes a power saving setting management unit 41 and a stress analysis unit 42. The power saving setting management unit 41 sets (changes) the first time set in the timer 31 based on the stress level perceived by the user. The power saving setting management unit 41 includes a switching detection unit 411 and a timer setting unit 412. The stress analysis unit 42 acquires the degree of stress perceived by the user using the computer 10. The stress analysis unit 42 includes an image reading unit 421, a feature amount calculation unit 422, and a stress level calculation unit 423.

  First, the switch detection unit 411 causes the image reading unit 421 to analyze the user's stress level in response to a notification from the OS 201 (switch notification unit 33) indicating that the computer 10 is switched from the normal operation state to the power saving state. Request. More specifically, the switching detection unit 411 requests the image reading unit 421 to acquire an image of the user in order to analyze the user's stress level. Note that the switch detection unit 411 may detect a message (event) issued by the OS 201 for switching the computer 10 from the normal operation state to the power saving state, not the notification by the switch notification unit 33. In that case, the switching detection unit 411 requests the image reading unit 421 to analyze the user's stress level in response to the detection of the message.

  The image reading unit 421 captures an image of the user using the computer 10 by using the camera module 115 in response to a request from the switching detection unit 411 (hereinafter also referred to as a user image). Generate. The image reading unit 421 outputs the generated user image to the feature amount calculation unit 422. The image reading unit 421 may turn off the camera module 115 after turning on the camera module 115 and generating a user image using the camera module 15 in response to a request from the switching detection unit 411. Thereby, the power consumption by the camera module 115 can be reduced.

  The feature amount calculation unit 422 calculates an image feature amount using the user image output by the image reading unit 421. The feature amount calculation unit 422 detects, for example, a face image area (that is, a user's face image) included in the user image, and a feature amount (a set of feature amounts) related to the shape (edge) or color included in the face image region. ) Is calculated. The feature amount calculation unit 422 outputs the calculated feature amount to the stress level calculation unit 423.

  The stress level calculation unit 423 calculates the stress level corresponding to the face image included in the user image. Specifically, the stress level calculation unit 423 refers to the facial expression database 5 to detect a facial expression having a feature quantity most similar to the feature quantity output by the feature quantity calculation unit 422, and associates the facial expression with the facial expression. Detect the degree of stress. The stress level calculation unit 423 outputs the detected stress level to the timer setting unit 412 (that is, returns it to the power saving setting management unit 41 that is a request source).

  FIG. 4 is a diagram schematically showing the relationship between the user's facial expression and the stress level. In this embodiment, for example, various facial expressions are defined at a plurality of discrete levels, and a stress level is associated with each prescribed facial expression. In the example shown in FIG. 4, it is assumed that the stress perceived by the user is small (no stress) in a facial expression (no expression) 61 in which emotions do not particularly appear, and the negative stress level (−5 points) is assumed. Associated. Further, in the facial expression 63 in which strong emotion such as an angry facial expression or a surprised facial expression appears, it is assumed that the stress perceived by the user is large (stress is present), and a positive stress level (+15 points) is associated. It has been. Similarly, the intermediate facial expression 62 is also associated with a degree of stress corresponding to the strength of emotion appearing in the facial expression.

  FIG. 5 shows a configuration example of the facial expression database 5 for defining the relationship between the user's facial expression and the stress level shown in FIG. The facial expression database 5 includes a plurality of entries corresponding to a plurality of facial expressions. Each entry includes, for example, a facial expression ID, feature amounts 1, 2,..., N, and a stress level. In an entry corresponding to a certain expression, “expression ID” indicates identification information assigned to the expression. The “feature amount” indicates a set of image feature amounts included in the facial image of the expression. In this “feature amount”, for example, an image feature amount calculated by classifying a large number of user face images for each facial expression and analyzing the face images classified into the same facial expression is set. The “stress level” indicates the degree of stress associated with the facial expression. In the “stress level”, not only a positive value but also a negative value is set, and the larger the value, the higher the stress.

  The stress level calculation unit 423 calculates the similarity between the feature amount included in each entry in the facial expression database 5 as described above and the feature amount output by the feature amount calculation unit 422, and the calculated similarity is The degree of stress included in the largest entry is detected.

  Each entry in the facial expression database 5 may include an image indicating a standard face for each facial expression instead of the “feature”. In this case, the stress level calculation unit 423 calculates the similarity between the face image in the user image captured by the camera 115 and the standard face image included in each entry, and the calculated similarity is the maximum. The degree of stress included in the entry is detected.

  The timer setting unit 412 includes a stress counter 412A for storing a cumulative value of the stress level. The timer setting unit 412 clears the stress counter 412A when the power saving management program 202 is started, for example. Clearing the stress counter 412A represents, for example, setting a predetermined initial value (for example, 50) in the stress counter 412A. The timer setting unit 412 is a first time set in the timer 31 to switch the computer 10 that is not operated by the user from the normal operation state to the power saving state based on the stress level output by the stress level calculation unit 423. To change.

  More specifically, the timer setting unit 412 adds the stress level output by the stress level calculation unit 423 and the value set in the stress counter 412A, and newly adds the added value to the stress counter 412A. Set to. That is, the timer setting unit 412 uses the stress counter 412A to calculate a cumulative value in which the stress level output by the stress level calculation unit 423 is accumulated.

  Next, when the value set in the stress counter 412A is larger than the timer increase threshold value (first threshold value), the timer setting unit 412 sets the first time set in the timer 31 to, for example, a predetermined value. The stress counter 412A is cleared by increasing the ratio (for example, 10%). That is, as the stress level perceived by the user is higher, the accumulated value of the stress level is more likely to exceed the first threshold value, and the user operation according to the fact that the accumulated value exceeds the first threshold value. The first time until the computer 10 that does not have a transition from the normal operation state to the power saving state is set longer than the current time. With this setting, for example, when the user browses a document or image displayed on the screen for a long time without operating the computer 10, the computer 10 shifts from the normal operation state to the power saving state. The possibility can be reduced. Therefore, it is possible to prevent the degree of stress perceived by the user from further increasing and improve the convenience for the user. An upper limit may be provided for the first time set in the timer 31. For example, when the first time lengthened by a predetermined ratio is larger than the upper limit value, the timer setting unit 412 changes the first time to the upper limit value (that is, the upper limit value is set in the timer 31).

  On the other hand, when the value set in the stress counter 412A is smaller than the threshold value for decrementing the timer (second threshold value), the timer setting unit 412 sets the first time set in the timer 31 to, for example, a predetermined value. The stress counter 412A is cleared by shortening the ratio (for example, 10%). In other words, the lower the stress level perceived by the user, the easier the stored value of the stress level falls below the second threshold value, and the user operation according to the fact that the stored value falls below the second threshold value. The first time until the computer 10 that does not have a transition from the normal operation state to the power saving state is set to be shorter than the current time. With this setting, for example, the computer 10 that has not been operated by the user can be shifted from the normal operation state to the power saving state earlier, so that the power saving effect can be enhanced. Note that a lower limit value may be provided for the first time set in the timer 31. For example, when the first time shortened by a predetermined ratio is smaller than the lower limit value, the timer setting unit 412 changes the first time to the lower limit value (that is, the lower limit value is set in the timer 31).

  As described above, by changing the first time set in the timer 31 based on the degree of stress, the usage pattern of the computer 10 for each user, the usage pattern that varies depending on the work contents even for the same user, etc. Since the first time is changed according to the above, the power saving effect can be enhanced while considering the convenience for the user. The user can use the computer 10 with less stress and less power consumption without manually setting the first time set in the timer 31.

  Note that the image reading unit 421 can generate not only a user image including the face in front of the user facing the screen of the display 17 but also a user image including a face other than the front such as a side face or a crawling face. The stress level calculation unit 423 can also refer to the facial expression database 5 to recognize a facial expression or a facial expression of a crawling face and detect a stress level associated with the facial expression.

  The first time set in the timer 31 includes a first user image captured before the timing at which the computer 10 is switched to the power saving state and a second user image captured after the timing. May be used to change. By using these first and second user images to calculate the difference in stress level before and after the computer 10 is switched to the power saving state, the change in the stress level caused by the switching to the power saving state is calculated. Can be acquired.

  More specifically, first, the image reading unit 421 immediately before the computer 10 is switched to the power saving state by the state switching unit 32 in response to a request for analysis of the user's stress level by the switching detection unit 411. A first user image is generated by imaging the user (a predetermined time before the switching timing). Then, the image reading unit 421 generates a second user image by imaging the user immediately after the computer 10 is switched to the power saving state by the state switching unit 32 (after a predetermined time from the switching timing).

  The feature amount calculation unit 422 calculates a first feature amount corresponding to the face image included in the first user image, and calculates a second feature amount corresponding to the face image included in the second user image. The stress level calculation unit 423 refers to the facial expression database 5 to calculate a first stress level associated with the facial expression corresponding to the first feature amount, and to calculate a second stress associated with the facial expression corresponding to the second feature amount. Calculate the degree. Then, the stress level calculation unit 423 calculates the difference between the first stress level and the second stress level as in the following equation.

Difference in stress level = second stress level−first stress level Next, the timer setting unit 412 determines the difference in the calculated stress level (change in the stress level due to the computer 10 being switched to the power saving state). The first time set in the timer 31 is changed. For example, when the difference in the stress level is larger than the threshold value for increasing the timer (for example, 10), the stress level is increased by switching, and therefore the timer setting unit 412 lengthens the first time by a predetermined rate. Further, for example, when the difference in the stress level is smaller than the threshold for timer decrease (for example, 0), the timer setting unit 412 considers that the stress level has not changed due to switching, and sets the first time to a predetermined ratio. Just shorten it. Thereby, the first time set in the timer 31 can be changed in consideration of the change in the degree of stress caused by switching to the power saving state.

  As described above, the image reading unit 421 can generate not only a user image including a front face of the user but also a user image including a face other than the front face such as a side face and a crawling face. When the user image includes a profile or a crawling face, the user does not watch the screen of the display 17, for example, and does not notice that the computer 10 has been switched to the power saving state. It is assumed that the expression does not change, that is, the stress level does not change by switching. Therefore, when the first and second user images including the side face and the scolding face are generated, the first time set in the timer 31 is shortened, and the power saving effect can be enhanced.

  In order to identify the front face and the side face or the crawling face, an entry corresponding to the side face or the crawling face may be created in the expression database 5. For example, a low stress level is associated with a side face or a crawling face. The stress level calculation unit 423 refers to the facial expression database 5 to detect that the feature amount calculated using the user image corresponds to the user's profile or scolding face, and detects an associated low stress level. To do. The timer setting unit 412 shortens the first time set in the timer 31 when the low stress level is output from the stress level calculation unit 423. Therefore, when a user image including a profile or a scolding face is generated, the first time set in the timer 31 is shortened, and the power saving effect can be enhanced. Further, according to this method, an appropriate time can be set in the timer 31 even for a side face or a crawling face whose facial expression is difficult to recognize.

  Further, the first time set in the timer 31 may be changed using a plurality of images acquired within a predetermined period including the timing at which the computer 10 is switched to the power saving state. By using a plurality of images, for example, a statistical value such as an average or cumulative stress level within a predetermined period including the timing at which the computer 10 is switched to the power saving state is acquired, and based on the statistical value of the stress level The first time can be changed.

  More specifically, first, the image reading unit 421 determines the timing at which the computer 10 is switched to the power saving state by the state switching unit 32 in response to a request for analysis of the user's stress level by the switching detection unit 411. A plurality of user images are generated by capturing an image of the user within a predetermined period. This predetermined period may be a predetermined period before and after the switching timing (for example, 3 seconds before and after the switching timing), or may be a predetermined period after the switching timing (for example, 2 seconds after the switching timing). . The image reading unit 421 turns on the camera module 115 in response to the request for the analysis of the degree of stress, and turns off the camera module 115 after the generation of the user image is completed.

  The feature amount calculation unit 422 calculates a feature amount (a feature amount set) corresponding to the face image included in each of the generated plurality of user images. Then, the stress level calculation unit 423 refers to the facial expression database 5 and calculates the stress level associated with the facial expression corresponding to the feature amount. That is, the stress level calculation unit 423 calculates a plurality of stress levels corresponding to a plurality of face images included in a plurality of user images. The stress level calculation unit 423 calculates, for example, an average stress level that indicates an average of a plurality of calculated stress levels.

  Next, the timer setting unit 412 changes the first time set in the timer 31 based on the calculated average stress level. For example, the timer setting unit 412 lengthens the first time when the average stress degree is larger than the timer increase threshold value, and shortens the first time when the average stress degree is smaller than the timer decrease threshold value. To do.

  The stress level calculation unit 423 corresponds to a first average stress level indicating an average of a plurality of stress levels corresponding to a plurality of user images before the switching timing, and a plurality of user images after the switching timing. You may calculate the difference with the 2nd average stress degree which shows the average of several stress degrees. The timer setting unit 412 changes the first time set in the timer 31 based on the calculated difference. For example, the timer setting unit 412 increases the first time when the calculated difference is larger than the timer increase threshold, and the first time when the calculated difference is smaller than the timer decrease threshold. To shorten.

  As described above, by using a plurality of user images, the degree of stress perceived by the user (or change in the degree of stress) can be estimated more accurately.

  Further, in order to estimate the degree of stress perceived by the user, the computer 10 may further be provided with an acceleration sensor for detecting vibration. This acceleration sensor can detect, for example, vibration caused by an input operation using the keyboard 13 or the like. The stress level calculation unit 423 calculates the stress level of the user who is using the computer 10 based on the detected magnitude and pattern of vibration. For example, the stress level calculation unit 423 calculates a high stress level (a stress level that is a positive value) when a vibration larger than an average vibration when used in the past is detected. The timer setting unit 412 can change the first time set in the timer 31 using the calculated degree of stress.

  Next, an example of a procedure of state switching processing executed by the computer 10 will be described with reference to the flowchart of FIG. In this state switching process, the computer 10 is switched between a normal operation state and a power saving state (standby state) that consumes less power than the normal operation state. In the following, it is assumed that the computer 10 is currently set to the normal operation state.

  First, the timer 31 determines whether or not an elapsed time (elapsed time when there is no operation) without a user operation on the computer 10 is greater than a first time (timer set time) set in the timer 31 ( Block B51). That is, the timer 31 determines whether or not the timer set time has expired. When the elapsed time without operation is equal to or shorter than the first time (NO in block B51), the process returns to block B51, and it is again determined whether the elapsed time without operation is greater than the first time.

  When the elapsed time without operation is greater than the first time (YES in block B51), the switching notification unit 33 indicates that the computer 10 shifts from the normal operation state to the power saving state (switching detection unit 202). 411) (block B52). Then, the state switching unit 32 switches the computer 10 from the normal operation state to the power saving state (block B53).

  Next, the operation detection unit 34 determines whether or not an operation on the computer 10 by the user has been detected (block B54). When an operation by the user is not detected (NO in block B54), the process returns to block B54, and it is determined again whether or not an operation by the user is detected.

  When an operation by the user is detected (YES in block B54), the state switching unit 32 switches the computer 10 from the power saving state to the normal operation state (block B55). Then, the processing from block B51 to block B55 is repeatedly executed.

  With the above processing, the computer 10 is in a normal operation state, and when the first time has passed without any user operation, the computer 10 shifts to the power saving state, is in the power saving state, and the user operation is detected. If it does, it will return to the normal operating state.

  Next, an example of the procedure of the power saving setting management process executed by the computer 10 will be described with reference to the flowchart of FIG. In this power saving setting management process, when the computer 10 is switched from the normal operation state to the power saving state, the first time set in the timer 31 is controlled based on the stress level perceived by the user. As described with reference to FIG. 6, the OS 201 uses the first time set in the timer 31 to set in the timer 31 a period in which the computer 10 is in a normal operation state and no operation is performed by the user. When the set first time is exceeded, the computer 10 is shifted from the normal operation state to the power saving state.

  First, the switching detection unit 411 determines whether a notification indicating that the computer 10 shifts to the power saving state is detected (block B11). When the notification is not detected (NO in block B11), the process returns to block B11, and it is determined again whether or not the notification indicating that the computer 10 shifts to the power saving state is detected.

  When the notification is detected (YES in block B11), the switching detection unit 411 requests the stress analysis unit 42 to analyze the stress level of the user, and acquires the analyzed stress level (block B12). This degree of stress indicates, for example, the degree of stress perceived by the user after the computer 10 is switched from the normal operation state to the power saving state. In addition, the degree of stress includes the degree of stress perceived by the user when the computer 10 was perceived in the normal operation state, and the degree of stress perceived by the user after switching from the normal operation state to the power saving state. The difference may be shown. The stress analysis process by the stress analysis unit 42 will be described later with reference to the flowchart of FIG.

  The timer setting unit 412 adds the acquired stress level to the stress counter 412A (block B13). That is, the timer setting unit 412 newly sets a value obtained by adding the value set in the stress counter 412A and the acquired stress level to the stress counter 412A. In the initial state (for example, when the power saving management program 202 is activated), a predetermined initial value (for example, 50) is set in the stress counter 412A. Therefore, clearing the stress counter 412A indicates that a predetermined initial value is set in the stress counter 412A.

  Next, the timer setting unit 412 determines whether or not the value of the stress counter 412A is larger than a timer increase threshold value (for example, 100) for increasing the timer 31 (block B14). When the value of the stress counter 412A is larger than the threshold value for increasing the timer for increasing the timer 31 (YES in block B14), the timer setting unit 412 sets the first time (the transition to the power saving state) set in the timer 31. (Timer value) is increased (block B15). For example, the timer setting unit 412 increases the first time set in the timer 31 at a constant rate. More specifically, when it is assumed that the certain ratio is 10% and 300 seconds is set in the timer 31, the timer setting unit 412 changes the timer 31 to 330 seconds.

  Then, the timer setting unit 412 determines whether or not the increased timer value is greater than a predetermined maximum value (for example, 600 seconds) (block B16). When the increased timer value is larger than the predetermined maximum value (YES in block B16), the timer setting unit 412 sets the predetermined maximum value in the timer 31 (block B17). That is, the timer setting unit 412 limits the upper limit value set in the timer 31 to the predetermined maximum value. Then, the timer setting unit 412 clears the stress counter 412A (sets an initial value in the stress counter 412A) (block B18).

  On the other hand, when the increased timer value is equal to or less than the predetermined maximum value (NO in block B16), the timer setting unit 412 holds the increased timer value as it is and clears the stress counter 412A (block B18).

  When the value of the stress counter 412A is equal to or smaller than the timer increase threshold value for increasing the timer 31 (NO in block B14), the timer setting unit 412 allows the stress counter 412A to decrease the timer 31. It is determined whether or not it is smaller than the timer decrement threshold (block B19). When the value of the stress counter 412A is smaller than the timer decrement threshold for decrementing the timer 31 (YES in block B19), the timer setting unit 412 decrements the first time set in the timer 31 (block) B20). For example, the timer setting unit 412 decreases the first time set in the timer 31 at a constant rate. More specifically, when it is assumed that the certain ratio is 10% and the timer 31 is set to 62 seconds, the timer setting unit 412 changes the timer 31 to 55.8 seconds.

  Then, the timer setting unit 412 determines whether or not the decreased timer value is smaller than a predetermined minimum value (for example, 60 seconds) (block B21). When the decreased timer value is smaller than the predetermined minimum value (YES in block B21), the timer setting unit 412 sets this minimum value in the timer 31 (block B22). That is, the timer setting unit 412 limits the lower limit value set in the timer 31 to the predetermined minimum value. In the example in which 55.8 seconds is set in the timer 31 in the block B20 described above, the timer setting unit 412 changes the value set in the timer 31 from 55.8 seconds to 60 seconds in the block B22. Then, the timer setting unit 412 clears the stress counter 412A (sets an initial value in the stress counter 412A) (block B23).

  On the other hand, when the decreased timer value is equal to or greater than the predetermined minimum value (NO in block B21), the timer setting unit 412 holds the decreased timer value as it is and clears the stress counter 412A (block B23).

  FIG. 8 shows an example of a procedure of stress analysis processing executed by the stress analysis unit 42. As described above, the stress analysis process is a process executed according to block B12 in FIG.

  First, the image reading unit 421 determines whether or not the switching detection unit 411 has requested the analysis of the stress level perceived by the user (block B31). If the analysis of the stress level is not requested (NO in block B31), the process returns to block B31 and it is determined again whether the analysis of the stress level is requested.

  When the analysis of the stress level is requested (YES in block B31), the image reading unit 421 turns on the power of the camera 115 (block B32). For example, the camera 115 is turned on only for a predetermined period including a transition timing at which the computer 10 shifts from the normal operation state to the power saving state (for example, 3 seconds before and after the transition timing, 2 seconds from the transition timing, etc.). To be. Thereby, the power consumption by the camera 115 can be reduced. The image reading unit 421 acquires an image captured by the camera 115 (block B33). For example, the camera 115 generates an image including a user's face (front face, side face, etc.) facing the screen of the display 17. The image reading unit 421 reads an image generated by the camera 115 and outputs the image to the feature amount calculation unit 422.

  The feature amount calculation unit 422 calculates the feature amount of the image by analyzing the image output by the image reading unit 421 (block B34). For example, the feature amount calculation unit 422 detects a face image region (that is, a user's face image) included in the image, and calculates a feature amount related to the shape (edge) and color included in the face image region. Then, the feature amount calculation unit 422 outputs the calculated feature amount to the stress degree calculation unit 423.

  The stress level calculation unit 423 recognizes the facial expression corresponding to the face image of the user by matching the feature amount output by the feature amount calculation unit 422 with the feature amount for each facial expression stored in the facial expression database 5, The degree of stress corresponding to the recognized facial expression is calculated (block B35). The facial expression database 5 includes, for example, a set of feature amounts corresponding to each of a plurality of facial expressions, and a stress level associated with each of the plurality of facial expressions. Therefore, the stress level calculation unit 423 refers to the facial expression database 5 and detects the stress level associated with the facial expression corresponding to the user's facial image. The stress level calculation unit 423 returns the calculated stress level to the request source (timer setting unit 412) (block B36). Then, for example, the image reading unit 421 turns off the power of the camera 115 after an image is acquired for a predetermined period in response to a request from the switching detection unit 411 (block B37).

  7 and FIG. 8, the first time until the non-operated computer 10 is switched from the normal operation state to the power saving state in consideration of the stress level of the user (the first time set in the timer 31). 1 hour) can be controlled. The timer setting unit 412 increases the first time set in the timer 31 when the degree of stress perceived by the user is high. Thereby, the stress which arises when the computer 10 transfers to a power saving state from a normal operation state and a user's operation | work is interrupted can be reduced, and the convenience by a user can be improved. The timer setting unit 412 further decreases the first time set in the timer 31 when the degree of stress perceived by the user is low.

  Therefore, according to this embodiment, it is possible to save power while considering convenience for the user. The user can use the computer 10 with less stress and less power consumption without manually setting the first time set in the timer 31.

  Note that all of the processing procedures of the present embodiment described with reference to the flowcharts of FIGS. 6 to 8 can be executed by software. For this reason, the same effect as this embodiment can be easily realized only by installing and executing this program on a normal computer through a computer-readable storage medium storing the program for executing this processing procedure. .

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 115 ... Camera module, 201 ... OS, 202 ... Power saving management program, 31 ... Timer, 32 ... State switching part, 33 ... Switching notification part, 34 ... Operation detection part, 41 ... Power saving setting management part, 411 ... Switching detection , 412... Timer setting unit, 412A ... stress counter, 42 ... stress analysis unit, 421 ... image reading unit, 422 ... feature amount calculation unit, 423 ... stress degree calculation unit, 5 ... display database.

Claims (10)

An electronic device having a power saving function,
A state switching means for switching the electronic device to a power saving state when a first time has elapsed without detecting an operation on the electronic device while the electronic device is in a normal operation state;
User image generation means for generating an image of the user by imaging the user in response to the electronic device being switched to the power saving state;
A stress level calculating means for calculating a stress level corresponding to a face image included in the image;
An electronic device comprising timer setting means for changing the first time based on the degree of stress.   The timer setting means calculates a cumulative value in which the calculated stress level is accumulated, and increases the first time when the cumulative value is larger than a first threshold, and the cumulative value is a second value. The electronic device according to claim 1, wherein the first time is decreased when the time is smaller than a threshold value.   The state switching unit further reduces the power consumption of the electronic device when the changed first time elapses without detecting an operation on the electronic device while the electronic device is in the normal operation state. The electronic device according to claim 1, wherein the electronic device is switched to a state. The user image generation means further generates a first image of the user by imaging the user before the timing when the electronic device is switched to the power saving state, and the user after the timing. To generate a second image of the user,
The stress level calculating means calculates a first stress level corresponding to a face image included in the first image, calculates a second stress level corresponding to a face image included in the second image, and Calculating the difference between the stress level and the second stress level,
The electronic device according to claim 1, wherein the timer setting unit changes the first time based on the calculated difference. The user image generation means further generates a plurality of images of the user by capturing the user for a predetermined period including a timing at which the electronic device is switched to the power saving state.
The stress level calculation means calculates a plurality of stress levels corresponding to a plurality of face images included in the plurality of images, calculates an average stress level indicating an average of the calculated multiple stress levels,
The electronic device according to claim 1, wherein the timer setting unit changes the first time based on the average stress level.   When the electronic device is switched to the power saving state, the user image generation unit powers on a camera module connected to the electronic device, generates an image of the user using the camera module, and the camera The electronic device according to claim 1, wherein the module is powered off.   The electronic device according to claim 1, wherein the stress level calculation unit recognizes an expression corresponding to a face image included in the image and calculates a stress level associated with the recognized expression.   The electronic device according to claim 1, wherein the state switching unit further switches the electronic device to the normal operation state when an operation on the electronic device is detected while the electronic device is in the power saving state. A power saving setting control method for controlling settings of an electronic device having a power saving function,
When the electronic device is in a normal operation state and an operation on the electronic device is not detected and a first time has elapsed, the electronic device is switched to a power saving state,
In response to the electronic device being switched to the power saving state, the user is imaged to generate an image of the user,
Calculating a stress level corresponding to the face image included in the image;
A power saving setting control method for changing the first time based on the degree of stress. A program executed by a computer having a power saving function,
A step of switching the computer to a power saving state when a first time has elapsed without detecting an operation on the computer while the computer is in a normal operation state;
In response to the computer being switched to the power saving state, imaging the user to generate an image of the user;
A procedure for calculating a stress level corresponding to a face image included in the image;
A program for causing the computer to execute a procedure for changing the first time based on the degree of stress.

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