Electronic device, electronic device controlling method, and computer program product

An electronic device includes: display controller; user presence determination module; user authentication module; and controller. The user presence determination module determines presence of a user based on image data received from the camera while dominating access to a camera. The user authentication module dominates access to the camera, if the display is put in a screen lock state and to perform a user authentication based on the image data. The controller turns off the display if the user present determination module determines that the user is absent and while the display has not been put in the screen lock state, and to cause the user presence determination module to release the access to the camera and to put the display in the screen lock state before turning on the display if it is determined after the display is turned off that the user is present.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2012-047346, filed on Mar. 2, 2012, the entire contents of which are incorporated herein by reference.

FIELD

Embodiments described herein relate generally to an electronic device, an electronic device controlling method, and a computer program product.

BACKGROUND

Conventionally, there is known a power saving technology for display devices such as televisions and displays, by detecting a condition that the user has not been using the display and by shutting down a display.

For example, the power saving is achieved by turning off the television in accordance with a detection state of a user's face captured by a capturing module, thereby preventing the television from displaying images while there are no viewers around.

Further, there is disclosed a technology of detecting a user who is not seated on a predetermined seat by capturing its image with a camera, thereby stopping to display images on the display screen.

When only one camera device is used to perform detection of user presence and user authentication, and when the display is turned on or off in accordance with the user presence, it might be considered to provide a screen lock function which works in association with turning on and off of the display, in order to improve security.

However, if the user presence detection process and the user authentication process are performed independently, because access to the camera is exclusive, contention might occur in use of the camera device, and might result in a deadlock depending on some conditions.

DETAILED DESCRIPTION

In general, according to one embodiment, an electronic device comprises: a display; a user presence determination module; a user authentication module; and a controller. The display controller is configured to display various types of information on a display. The user presence determination module is configured to determine presence of a user based on image data received from the camera, while dominating access to a camera. The user authentication module is configured to dominate access to the camera, if the display is put in a screen lock state and to perform a user authentication based on the image data received from the camera. The controller is configured turn off the display if the user presence determination module determines that the user is absent and while the display has not been put in the screen lock state, and to cause the user presence determination module to release the access to the camera and to put the display in the screen lock state before turning on the display if it is determined after the display is turned off that the user is present.

An embodiment will now be explained in detail with reference to accompanying drawings.

FIG. 1is a block diagram of an outlined configuration of an information processor, which is an electronic device, according to the embodiment.

An information processor10according to the first embodiment is configured as a laptop personal computer (PC) having a camera.

The information processor10comprises a micro-processing unit (MPU)11that controls the overall information processor10, a read-only memory (ROM)12being a non-volatile memory storing therein control programs and the like executed by the MPU11, a random access memory (RAM)13that is used as a working area of the MPU11and temporarily stores therein various types of data, an internal input/output (I/O) (I/O module)14performing various interfacing operations, and an external storage device15configured as a hard disk drive, a solid state disk (SSD), or the like connected via the internal I/O14and storing therein various types of data.

The information processor10comprises a display17configured as a liquid crystal display, an electroluminescent (EL) display, or the like housed in a display panel module16, a camera18being a camera device including charge coupled device (CCD) imaging elements or complementary metal oxide semiconductor (CMOS) imaging elements, an operation device19configured as a keyboard, a touch panel, a mouse, and the like and allowing a user to perform various operations, and a memory card reader-writer (R/W)20into which a memory card MC that is a recording medium is inserted and that reads and writes various types of data.

Operations according to the embodiment will now be explained.

FIG. 2is a flowchart of outlined operations of the information processor10according to the embodiment.

It is assumed herein that, as an initial condition, the camera18is powered off, and the display is powered on.

To begin with, when the information processor10is powered on (S11), the MPU11refers to power plan setting data of an operating system (OS), and acquires power plan settings (S12).

The power plan setting is specified as a continuous time period during which a user perform no operation, from when a state in which the user perform no operation is detected in the information processor10to when a transition is made to a predetermined power saving mode.

The following four types of the power saving modes are available in the embodiment.

(1) Display brightness reduction mode

(3) Information processor (computer) sleep mode

(4) Information processor (computer) hibernation mode

The display brightness reduction mode saves power by reducing the amount of light output from backlights when the display is a backlight liquid crystal display.

The display power-off mode powers off the display, so that only a standby power is consumed. It goes without saying that, if the display is a backlight liquid crystal display, all of the backlights are turned off.

The information processor sleep mode is a state corresponding to the sleep state S3according to the Advanced Configuration and Power Interface (ACPI) Specification, which is one of the standards related to power savings of personal computers. This is a power saving mode that suppresses power consumption by powering off devices such as a display function, an external storage device, and the like. In the sleep mode, because power is kept supplied to the RAM so that data currently being processed is maintained as it is, the information processor10can be resumed from where the work is stopped, unlike when the information processor is powered off and then powered on. In addition, a normal operation mode can be quickly recovered, e.g., within a few seconds, from the information processor sleep mode.

The information processor hibernation mode is a state corresponding to the sleep state S4according to the ACPI Specification. This is a mode that saves the content of the RAM13in the external storage device15, such as a hard disk drive, and then powering off the devices including the RAM13. Therefore, an area for saving the data before making a transition to the hibernation is reserved in the storage area of the external storage device15, in the memory capacity almost the same as the RAM13. In the information processor hibernation mode, the information processor10is put in a state substantially the same as that of when the information processor10is powered off, unlike in the information processor sleep mode.

However, because the information processor10is required to save or to read the content of the RAM13in or from the external storage device15, it takes time to make a transition to or recover from the information processor hibernation mode.

From the viewpoint of the device, the information processor10in both the information processor sleep mode and the information processor hibernation mode is in a state almost the same as that of when the information processor10is powered off. Therefore, in order to make transition to each mode, devices and device drivers needs to be completed and initialized as similar to the shutdown and system boot up (power on) for recovery.

FIGS. 3A and 3Bare schematic diagrams for explaining an example of the power plan settings.

There are four types of power plan settings according to the embodiment, as illustrated inFIGS. 3A and 3B, in a manner corresponding to the power saving modes explained above. These types include a power plan setting TDIM corresponding to the display brightness reduction mode, a power plan setting TOFF corresponding to the display power-off mode, a power plan setting TSLP corresponding to the information processor (computer) sleep mode, and a power plan setting TSTP corresponding to the information processor (computer) hibernation mode.

The power plan setting is set to an OS timer managed by the MPU11mainly under the control of the OS. When the time specified in the power plan setting has elapsed from the time when a user stops making any operation, the operation mode is changed to a corresponding power saving mode. In the explanation below, the power plan settings are set in unit of a minute.

In the specific example of the power plan settings illustrated inFIG. 3A, the power plan setting TDIM corresponding to the display brightness reduction mode is set to 2 minutes, the power plan setting TOFF corresponding to the display power-off mode is set to 10 minutes, the power plan setting TSLP corresponding to the information processor sleep mode is set to 20 minutes, and the power plan setting TSTP corresponding to the information processor hibernation mode is set to 30 minutes.

In another example illustrated inFIG. 3B, the power plan setting TDIM corresponding to the display brightness reduction mode is set to none, the power plan setting TOFF corresponding to the display power-off mode is set to none, the power plan setting TSLP corresponding to the information processor (computer) sleep mode is set to 25 minutes, and the power plan setting TSTP corresponding to the information processor (computer) hibernation mode is set to 50 minutes.

Based on the power plan setting TDIM, the power plan setting TOFF, the power plan setting TSLP, and the power plan setting TSTP acquired at S12, the MPU11identifies a power plan setting TMIN that is the power plan setting specified with the shortest time among these power plan settings, and calculates and sets a face detection interval time (S13).

More specifically, in the example illustrated inFIG. 3A, because the power plan setting TDIM corresponding to the display brightness reduction mode is specified with the shortest time, the MPU11sets TMIN to TDIM.

Similarly, in the example illustrated inFIG. 3B, because the power plan setting TSLP corresponding to the information processor sleep mode is specified with the shortest time, the MPU11sets TMIN to TSLP.

FIG. 4is a general schematic diagram for explaining a method of calculating the face detection interval.

The MPU11then determines to which one of equal to or less than 1 minute, more than 1 minute and less than 20 minutes, and equal to or more than 20 minutes the power plan setting specified with the shortest time belongs.

If the power plan setting specified with the shortest time is equal to or less than 1 minute, the MPU11sets the face detection interval time TINT to 45 seconds.

If the power plan setting specified with the shortest time TMIN is more than 1 minute and equal to or less than 20 minutes, the MPU11sets the face detection interval time TINT to TMIN/2 minutes.

If the power plan setting specified with the shortest time TMIN is more than 20 minutes, the MPU11sets the face detection interval time TINT to 10 minutes.

Therefore, in the example illustrated inFIG. 3A, because TMIN=TDIM=2 minutes, the face detection interval time TINT is set as: TINT=2/2=1 minute.

Similarly, in the example illustrated inFIG. 3B, because TMIN=TDIM=25 minutes, the face detection interval time TINT is set as: TINT=10 minutes.

The MPU11sets the face detection interval time TINT (=X) to a face detection interval timer (internal timer) used when the user is present, and causes the timer to start counting.

The MPU11then goes to a routine process including a user presence detection and a user authentication (S14).

FIG. 5is a flowchart of the regular process.

To begin with, the MPU11performs a user presence detection process at every Y seconds (S21). Y is time set to the face detection interval timer (internal timer) used when the user is absent, and specified with relatively short time to enable the presence of the user to be detected quickly. In this manner, the user is prevented from feeling anxious about the information processor10not starting to operate. Specifically, Y is specified with time of approximately 2 seconds.

When the face detection interval timer completes counting, in other words, in every two seconds in the example explained above, the MPU11powers on the camera18only for a time required for image capturing, and causes the camera18to capture the image. The MPU11then acquires the image thus captured, and powers off the camera18again. The MPU11then performs a face detection process, that is, the user presence detection process (S21).

The MPU11then determines if a face is detected, i.e., the presence of the user, in the face detection process at S21(S22).

If no face is detected at the determination at S22, i.e., if the user is absent (No at S22), the MPU11determines if an operation on the operation device19by the user is detected (S23).

If no user operation on the operation device19is detected at the determination at S23(No at S23), the MPU11returns the process to S21, and the same process is repeated thereafter.

If a user operation on the operation device19is detected in the determination at S23(Yes at S23), the MPU11proceeds to the process to S24.

If a face is detected, in other words, if presence of the user is detected at the determination at S22(Yes at S22), the MPU11determines if a lock setting requiring a user authentication is enabled in the information processor10(S24).

If it is determined that the lock setting is disabled at the determination at S24(No at S24), the MPU11powers on the display17via the internal I/O14(S35), and proceeds to the process to S31.

Powering on the display17herein means to cause the display17to display an image effectively, and includes not only actually powering on the display, but also turning on the backlight, when the display17is a liquid crystal display using a backlight, for example (the same can be said for the explanation hereunder).

When it is determined that the lock setting is enabled at the determination at S24(Yes at S24), because the user presence detection process (user presence process application) stops dominating the access to the camera18, the MPU11releases the access to the camera18(a camera device) (S25).

The MPU11then performs a locking process so as to allow the user authentication process (user authentication application) to dominate access to the camera18(camera device) (S26).

The MPU11then powers on the display17(or keeps the power on of the display17) via the internal I/O14(S27).

FIG. 6is a schematic diagram for explaining how an exemplary log-on window (lock window) is displayed (S28).

Once the display17is powered on, the MPU11displays a log-on window, such as the one illustrated inFIG. 6, onto the display screen of the display17.

The MPU11then performs a user authentication process using the user authentication application (S29). Specifically, the MPU11captures an image by powering the camera18on only for a time required for the image capturing, acquires data thus captured, and powers off the camera18again. The MPU11then detects the face of the user from the image represented by the captured data, and performs an image recognition process, such as pattern matching, and determines if the face of the user thus detected corresponds to the face of an authorized user.

The MPU11then determines if the user authentication is completed in the user authentication process at S29, in other word, determines if the user authentication application was able to detect the face of an authorized user (S30).

If the user authentication application was not able to detect the face of the authorized user in the determination at S30(No at S30), the MPU11determines that the user authentication is incomplete, and proceeds to the process to S28again, and the same process is repeated thereafter.

If the user authentication application was able to detect the face of the authorized user in the determination at S30(Yes at S30), the MPU11determines that the user authentication is completed, displays a desktop image on the display screen of the display17, and causes the information processor10to perform a routine operation (S31).

The MPU11then sets the face detection interval time (X minutes) to the face detection interval timer (internal timer) for detecting the presence of the user, and causes the timer to start counting.

The MPU11determines if the face detection interval timer reaches the count (is counted up). When the face detection interval timer reaches the count, in other word, once in every X minutes, the MPU11captures an image by powering the camera18on only for a time required for the image capturing, acquires data thus captured, and powers off the camera18again.

The MPU11then performs the face detection process, that is, the user presence detection process (S32)

The MPU11then determines if the face is detected in the face detection process at S33, in other word, determines if the presence of the user is detected (S33).

If no face is detected, in other word, the presence of the user is not detected in the determination at S33(No at S33), the MPU11powers off the display17via the internal I/O14(S34).

Powering off the display17herein means an off-state in which the display17stops displaying an image effectively, and includes not only actually powering off the display, but also turning off the backlight, when the display17is a liquid crystal display using a backlight, for example. In other words, powering off includes a situation where the display control is continued but no image is effectively displayed.

The MPU11then proceeds to the process to S21, and the same process is repeated thereafter.

If the face is detected in the determination at S33, in other word, the presence of the user is detected (Yes at S33), the MPU11returns the process to S31, and the same process is performed thereafter.

As explained above, according to the embodiment, immediately after the information processor10is powered on and when absence of the user is detected, the user presence detection process (user presence detection application) has an exclusive access to the camera18(camera device).

By contrast, once presence of the user is detected while the lock setting is enabled, in order to perform the user authentication, the user presence detection process (user presence detection application) is caused to release the access to the camera18(a camera device), and then the locking process, which is a prerequisite for a user authentication, is performed before powering on the display17. Therefore, security can be ensured, without permitting the display17to display the desktop image used in the routine operation.

Furthermore, because the access to the camera18is released before the process proceeds to the user authentication process (user authentication application), the user authentication process (user authentication application) can reliably acquire and make use of the exclusive access to the camera18. As a result, the user authentication process (user authentication application) can reliably perform the user authentication process using the camera18, and therefore, usability of the user is improved.

FIG. 7is a block diagram of a general configuration of an information processor according to a modification of the embodiment.

Explained in the above embodiment is an example in which the information processor10is a laptop personal computer comprising an internal camera, and the display17and the camera18are integrally housed in the display panel16of the information processor10. An information processor10A according to the modification is configured as a desktop personal computer comprising an external input/output (I/O) module21for performing various interface operations with an external device, instead of the display panel16in which the display17and the camera18are integrally housed, and to which an external display23is connected via the external I/O21. A camera22is then integrally housed in the external display23.

In the modification of the embodiment having such a configuration as well, when the user presence detection process (user presence detection application) or the user authentication process (user authentication application) dominates the access to a single camera18that is externally connected, the access can be granted reliably as required. Reliably avoided thereby without sacrificing the usability of users is a deadlock leading to situations where neither one of the user presence detection process and the user authentication process can be performed.

Explained above is an example in which the electronic device is an information processor (computer), but the embodiment can be applied to any electronic device using a display, such as a television and a video recorder.

Explained above is an example in which the face detection interval timer is set only once as initial setting. However, it is also possible to set the face detection interval time shorter than the face detection interval time set at S13when the user presence is no longer detected (No at S33) and the display is powered off (S34), until the user presence is detected again. Furthermore, it is also possible to keep performing the face detection successively, without setting the face detection interval time.

Furthermore, there are no explanations about when the power plan setting is updated, above. However, when the power plan setting is updated, the time set to the face detection interval timer is also updated. In this manner, the face detection interval timer is always set to be shorter than the shortest time to which the power plan setting is specified, and energy saving can be achieved reliably.

The control program executed on the electronic device according to the embodiment is provided in a manner incorporated in the ROM or the like in advance.

The control program executed on the electronic device according to the embodiment may also be provided in a manner recorded in a computer-readable recording medium, such as a compact disk read-only memory (CD-ROM), a flexible disk (FD), a compact disk recordable (CD-R), a digital versatile disk (DVD), and a memory card, as a file in an installable or executable format.

Furthermore, the control program executed on the electronic device according to the embodiment may be stored in a computer connected to a network such as the Internet, and may be made available for downloads over the network. Furthermore, the control program executed on the electronic device according to the embodiment may be provided or distributed over a network such as the Internet.

The control program executed on the electronic device according to the embodiment has a modular structure including each module explained above (a display controller, a user presence determination module, a reference elapsed time storage module, an interval time setting module, and a power controller). As actual hardware, for example, by causing a central processing unit (CPU) (processor) to read the computer program from the ROM and to execute the computer program, each of the display controller, the user presence determination module, the reference elapsed time storage module, the interval time setting module, and the power controller is loaded onto the main memory, and is generated on the main memory.