Information processor and control method

Abstract

To provide an information processor and a control method that improve stability of control using a distance measurement sensor.SOLUTION: An information processor performs figure detection processing to detect a figure present within a range of a first distance by using a distance measurement sensor that measures a distance to an object, and face direction determination processing to determine, when the figure is detected within the range of the first distance by the figure detection processing, a direction of a face of the figure. The information processor, in the face direction determination processing, determines, when the figure detected by the figure detection processing is within a range of a second distance that is closer than the first distance, the face direction of the figure by using the distance measurement sensor, maintains, when the figure detected by the figure detection processing moves from within the range of the second distance to outside the range of the second distance, a determination result of the face direction determined within the range of the second distance, and fixes, when the figure is detected outside the range of the second distance within the range of the first distance range from a state in which no figure is detected within the first distance by the person detection processing, a face direction determination result to a preset value.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to an information processing device and a control method. [Background technology]

[0002] There is a device that automatically activates a system when it detects the approach of a person using a distance sensor (ranging sensor) that detects distance using infrared rays or the like (for example, Patent Document 1).

[0003] Furthermore, in recent years, advances in computer vision and the like have improved the accuracy of detecting faces from images captured by cameras, and people are now being detected by face detection. Face detection not only detects people but also determines the orientation of the face, making it possible to control the device according to the orientation of the face (whether the person is facing forward, facing sideways, etc.). For example, when the face is facing sideways, the screen brightness is reduced or turned off to prevent unnecessary power consumption during periods when the user is not using the device. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2020-102151 Summary of the Invention [Problem to be solved by the invention]

[0005] Determining face orientation using face detection as described above requires a large development load related to image recognition for face detection and consumes a lot of power because it requires capturing images using a camera. Therefore, a simple method using a ranging sensor to determine the face orientation of a person can be considered to reduce power consumption. For example, determining face orientation using a ranging sensor can be done by utilizing the difference between the distance measurement values ​​for the upper and lower parts of the face, or the difference between the distance measurement values ​​for the left and right parts of the face. However, since the determination must be based on slight differences in distance measurement values ​​due to changes in face orientation, errors in ranging at long distances can be obscured, limiting the range of determination to short distances. Therefore, while a ranging sensor is used to determine the face orientation of a person within the short distance range within which a person can be detected, measures are taken, such as fixing the determination that the face is facing forward when the distance exceeds the range at which the ranging sensor can determine the face orientation.

[0006] If a distance sensor is used to determine the direction of the face within the range of distances where the direction of the face can be determined, and the determination is fixed as the face facing forward when the range of distances where the direction of the face can be determined is exceeded, the determination result will change unstably near the boundary of the range of distances where the direction of the face can be determined, and there is a concern that the screen brightness will also become unstable if the screen brightness is controlled based on this determination result.

[0007] The present invention has been made in view of the above circumstances, and one of its objects is to provide an information processing device and a control method that improve the stability of control using a distance measuring sensor. [Means for solving the problem]

[0008] The present invention has been made to solve the above-mentioned problems, and an information processing device according to a first aspect of the present invention comprises a ranging sensor that measures the distance to an object, a memory that temporarily stores distance information indicating the distance measured by the ranging sensor, and a processor that executes processing based on the distance information, wherein the processor performs a person detection process that uses the ranging sensor to detect a person present within a first distance range, and a face direction determination process that determines the face direction of the person when a person is detected within the first distance range by the person detection process, and in the face direction determination process, if the person detected by the person detection process is within a second distance range that is closer than the first distance, the processor determines the face direction of the person using the ranging sensor, and if the person detected by the person detection process moves from within the second distance range to outside the second distance range, the processor maintains the face direction determination result determined within the second distance range, and fixes the face direction determination result to a preset value when a person is detected outside the second distance range within the first distance range by the person detection process after not detecting a person within the first distance range.

[0009] In the above information processing device, the processor may, in the face direction determination process, maintain the determination result of the face direction determined within the second distance range when the person detected by the person detection process moves from within the second distance range to outside the second distance range, and then, when the person detected by the person detection process moves again within the second distance range, release the maintenance of the determination result and determine the face direction of the person using the ranging sensor.

[0010] In the above information processing device, the processor may, in the face direction determination process, maintain the determination result of the face direction determined within the second distance range due to a person detected by the person detection process moving from within the second distance range to outside the second distance range, and then, if the person detection process results in a state where no person is detected within the first distance range, cancel the maintenance of the determination result and terminate the face direction determination process.

[0011] In the above information processing device, the processor may, in the face direction determination process, fix the determination result of the face direction when a person is detected outside the second distance range within the first distance range by the person detection process from a state in which no person is detected within the first distance range, and then, when the person detected by the person detection process moves from outside the second distance range to within the second distance range, release the fixation of the determination result and determine the face direction of the person using the ranging sensor.

[0012] In the above information processing device, the processor may, in the face direction determination process, fix the face direction determination result when the person detection process changes from a state in which no person is detected within the first distance range to a state in which a person is detected outside the second distance range within the first distance range, and then release the fixation of the determination result and terminate the face direction determination process if the person detection process changes to a state in which no person is detected within the first distance range.

[0013] In the above information processing device, the processor may, in the face direction determination process, determine whether the face direction of a person detected within the first distance range by the person detection process is facing toward the information processing device, and when fixing the face direction determination result to a preset value, fix the face direction determination result to one in which the person's face direction is facing toward the information processing device.

[0014] In the information processing device, the processor may perform a screen brightness control process to control a screen brightness of a display unit based on the face direction determined by the face direction determination process.

[0015] Furthermore, according to a second aspect of the present invention, there is provided a control method for an information processing device including a ranging sensor that measures the distance to an object, a memory that temporarily stores distance information indicating the distance measured by the ranging sensor, and a processor that executes processing based on the distance information, the control method including a person detection step in which the processor detects a person present within a first distance range using the ranging sensor, and a face direction determination step in which, when a person is detected within the first distance range by the person detection step, the processor determines the face direction of the person using the ranging sensor in the face direction determination step if the person detected by the person detection step is within a second distance range that is closer than the first distance, and when the person detected by the person detection step moves from within the second distance range to outside the second distance range, the face direction determination result determined within the second distance range is maintained, and when a person is detected outside the second distance range within the first distance range after a state in which no person was detected within the first distance range by the person detection step, the face direction determination result is fixed to a preset value. [Effects of the Invention]

[0016] According to the above aspects of the present invention, it is possible to improve the stability of control using a distance measuring sensor. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a perspective view showing an example of the external configuration of an information processing apparatus according to an embodiment. [Figure 2] FIG. 4 is a diagram showing an example of a person detection range of the information processing apparatus according to the embodiment. [Figure 3] 10A and 10B are explanatory diagrams of a method for determining a face direction according to an embodiment. [Figure 4] 3A and 3B are schematic diagrams showing a first example of human detection and face direction determination using a TOF sensor according to an embodiment. [Figure 5] 5A and 5B are schematic diagrams showing a second example of human detection and face direction determination using a TOF sensor according to the embodiment. [Figure 6]10A and 10B are schematic diagrams showing a third example of human detection and face direction determination using a TOF sensor according to the embodiment. [Figure 7] FIG. 1 is a schematic block diagram showing an example of a hardware configuration of an information processing apparatus according to an embodiment. [Figure 8] FIG. 1 is a schematic block diagram showing an example of the functional configuration of an information processing apparatus according to an embodiment. [Figure 9] 10 is a flowchart showing an example of a face direction determination process according to the embodiment. [Figure 10] 10 is a flowchart showing an example of a screen brightness control process according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. First, an overview of an information processing device 1 according to this embodiment will be described. [overview] 1 is a perspective view showing an example of the external configuration of an information processing device 1 according to this embodiment. The information processing device 1 is, for example, a notebook PC (Personal Computer).

[0019] The information processing device 1 is, for example, a notebook (clamshell) type PC (Personal Computer). The information processing device 1 includes a first housing 10, a second housing 20, and a hinge mechanism 15. The first housing 10 and the second housing 20 are connected using the hinge mechanism 15. The first housing 10 is rotatable relative to the second housing 20 around a rotation axis defined by the hinge mechanism 15. The opening angle resulting from the rotation of the first housing 10 and the second housing 20 is shown as "θ".

[0020] The first housing 10 is also referred to as an A cover or a display housing. The second housing 20 is also referred to as a C cover or a system housing. In the following description, the sides of the first housing 10 and the second housing 20 on which the hinge mechanism 15 is provided are referred to as side 10c and 20c, respectively. The sides of the first housing 10 and the second housing 20 opposite side 10c and 20c are referred to as side 10a and 20a, respectively. In the drawings, the direction from side 20a to side 20c is referred to as "rear," and the direction from side 20c to side 20a is referred to as "front." Furthermore, when looking forward from the information processing device 1, the direction toward the right is referred to as "rightward," and the direction toward the left is referred to as "leftward." The right sides of the first housing 10 and the second housing 20 are referred to as side 10b and 20b, respectively, and the left sides are referred to as side 10d and 20d, respectively. Furthermore, the state in which the first housing 10 and the second housing 20 overlap and are completely closed (a state in which the opening angle θ=0°) is referred to as the "closed state." In the closed state, the surfaces of the first housing 10 and the second housing 20 that face each other are referred to as the "inner surfaces," and the surfaces opposite the inner surfaces are referred to as the "outer surfaces." Furthermore, the state in which the first housing 10 and the second housing 20 are open relative to the closed state is referred to as the "open state."

[0021] The external appearance of the information processing device 1 shown in FIG. 1 is an example of an open state. In the open state, the side surface 10a of the first housing 10 and the side surface 20a of the second housing 20 are separated. In the open state, the inner surfaces of the first housing 10 and the second housing 20 are exposed. The open state is one of the states in which a user uses the information processing device 1, and it is typically used with an opening angle θ of approximately 100 to 130°. The range of the opening angle θ that results in the open state can be determined arbitrarily depending on the range of angles that can be rotated by the hinge mechanism 15, etc.

[0022] A display unit 110 is provided on the inner surface of the first housing 10. The display unit 110 is configured to include a liquid crystal display (LCD), an organic electroluminescence (EL) display, or the like. A TOF sensor 130 is provided on the inner surface of the first housing 10 in a peripheral region of the display unit 110. For example, the TOF sensor 130 is disposed on the side surface 20a side of the peripheral region of the display unit 110. Note that the position where the TOF sensor 130 is disposed is just an example, and the TOF sensor 130 may be disposed in another location as long as it can face in a direction facing the display screen of the display unit 110.

[0023] The TOF sensor 130 is a distance measurement sensor that measures the distance to an object (e.g., a person) present in a direction facing the display screen of the display unit 110 (i.e., in front of the information processing device 1). For example, the TOF sensor 130 includes a light-emitting unit that emits infrared rays and a light-receiving unit that receives the reflected light of the emitted infrared rays that reflects off the surface of the object. The TOF sensor 130 emits infrared rays forward at a predetermined sampling period (e.g., 1 Hz) and receives the reflected light of the emitted infrared rays, thereby outputting a distance measurement signal corresponding to the distance to the object (e.g., a person) using a ToF (Time of Flight) method that converts the time difference between emission and reception of the infrared rays into distance.

[0024] A power button 140 is provided on the side surface 20b of the second housing 20. The power button 140 is an operator that allows the user to instruct turning the power on or off, transitioning from a standby state to a normal operating state, transitioning from the normal operating state to a standby state, etc. The normal operating state is an operating state of the system in which processing can be executed without any particular restrictions, and corresponds to, for example, the S0 state defined by ACPI (Advanced Configuration and Power Interface).

[0025] The standby state is a state in which at least a portion of system processing is restricted and in which power consumption is lower than in the normal operating state. For example, the standby state may be a standby state, a sleep state, or the like, and may be a state equivalent to Modern Standby in Windows (registered trademark) or the S3 state (sleep state) defined by ACPI. The standby state may also include a state in which at least the display of the display unit is turned off (screen off) or a state in which the screen is locked. The screen lock is a state in which a preset image (e.g., a screen lock image) is displayed on the display unit so that the contents of processing cannot be seen, and the device cannot be used until the lock is released (e.g., user authentication is performed).

[0026] Furthermore, a keyboard 151 and a touchpad 153 are provided on the inner surface of the second housing 20 as input devices that accept user operation inputs. Note that, instead of or in addition to the keyboard 151 and the touchpad 153, a touch sensor may be provided as the input device, or a mouse or an external keyboard may be connected. In the case where a touch sensor is provided, an area corresponding to the display screen of the display unit 110 may be configured as a touch panel that accepts operations. The input device may also include a microphone that inputs voice.

[0027] In addition, when the first housing 10 and the second housing 20 are in a closed state, the display unit 110 provided on the inner surface of the first housing 10 and the keyboard 151 and touchpad 153 provided on the inner surface of the second housing 20 are covered by the surface of the other housing, and are unable to function.

[0028] The information processing device 1 executes HPD (Human Presence Detection) processing to detect a person present in front of the information processing device 1 based on the distance measurement signal output by the TOF sensor 130.

[0029] 2 is a diagram showing an example of the distance measurement range of the TOF sensor 130 according to this embodiment. In the open state, the TOF sensor 130 arranged on the inner surface of the first housing 10 measures the distance to an object (e.g., a person) in the direction facing the inner surface of the first housing 10 (forward). The TOF sensor 130 is a distance measurement sensor for detecting a person (e.g., a user) present in front, and the detection range for detecting a person is called the detection range FoV (Field of View: detection field of view angle). The detection range FoV corresponds to the range of angles over which the TOF sensor 130 can measure distances.

[0030] For example, the TOF sensor 130 divides the detection range FoV into measurement units of 8x8 squares and measures the distance for each square (measurement unit). Note that, since the purpose is to detect a person (user) using the information processing device 1, distances to objects that are a certain distance or more (for example, 2 m) away may be excluded from the distance measurement targets. Note that it is impossible to measure the distance to objects that are too far away for infrared rays to reach them.

[0031] The information processing device 1 controls the operating state of the system of the information processing device 1 according to the presence or absence of a person through HPD processing. For example, when the information processing device 1 detects that a person approaches the information processing device 1 and that the person is present in front of the information processing device 1, the information processing device 1 starts up the system and controls it to a normal operating state. Furthermore, when a person leaves the information processing device 1 and the person is no longer detected in front of the information processing device 1, the information processing device 1 controls it to a standby state.

[0032] Furthermore, when the information processing device 1 detects the presence of a person in front of the information processing device 1, the information processing device 1 detects the direction of the person's face based on the ranging signal output by the TOF sensor 130. For example, the information processing device 1 determines whether the person's face is facing the direction of the information processing device 1 (the direction of the display unit 110). Here, a state in which the person's face is facing the direction of the information processing device 1 (the direction of the display unit 110) (a state in which the person's face is facing forward relative to the information processing device 1) is defined as a state in which the person is paying attention to the information processing device 1. On the other hand, a state in which the person's face is not facing the direction of the information processing device 1 (the direction of the display unit 110) (a state in which the person's face is facing left, right, up, or down relative to the information processing device 1 and is not facing forward relative to the information processing device 1) is defined as a state in which the person is not paying attention to the information processing device 1.

[0033] For example, the information processing device 1 controls (dimming control) the screen brightness of the display unit 110 according to the determination result of the face direction. Specifically, when the face is not facing forward (when the person is not paying attention to the information processing device 1), the information processing device 1 saves power by lowering the screen brightness of the display unit 110. Furthermore, when the face is facing forward again (when the person is paying attention to the information processing device 1), the information processing device 1 returns the screen brightness to the original level before lowering it.

[0034] Hereinafter, the original screen brightness before being reduced will be referred to as "standard brightness." Also, the screen brightness reduced from the standard brightness when the face is not facing forward will be referred to as "low brightness." Low brightness is at least a brightness lower than the standard brightness, and the lower the brightness, the greater the power saving effect. For example, low brightness may be a brightness of about 0 to 10% of the standard brightness.

[0035] (How to determine face direction) Next, a method for determining the face orientation based on the ranging signal output from the TOF sensor 130 will be described. In this embodiment, the information processing device 1 determines the face orientation as front, left, right, up, or down. The left-right orientation refers to the face orientation in the horizontal direction corresponding to the rotation direction around a vertical axis passing through the center of the face. The up-down orientation refers to the face orientation in the vertical direction corresponding to the rotation direction around a horizontal axis passing through the center of the face.

[0036] FIG. 3 is an explanatory diagram of a face orientation determination method according to this embodiment. In this diagram, the detection range FoV is divided into 64 measurement units of 8×8 squares, and an example of a distance measurement value for each square (measurement unit) is represented by a number within each square. For example, the distance measurement value for each square is a distance measurement value measured by the TOF sensor 130 at a predetermined cycle (e.g., every 1 second). Since people move to some extent, the distance measurement value for each square is constantly fluctuating. Therefore, in order to obtain a highly reliable distance measurement value, the distance measurement values ​​measured at a predetermined cycle (e.g., every 1 second) may be time-averaged.

[0037] In this diagram, the distance measurement values ​​shown in numbers within each square are in millimeters. In the example shown, squares with distance values ​​between 450 and 610 are the range in which a person is present. Squares with distance values ​​of 1000 or more are the distance measurement values ​​for objects on the ceiling or behind the person. Squares with no distance measurement value displayed are squares where the object is too far away to be measured.

[0038] The range of a person has the characteristic that the edges of the range are roughly mountain-shaped, and the width of the part of the torso above the shoulders is shorter than the width of the shoulders. For example, when the edges of the range of squares where distance measurement values ​​with small differences (here, about 450 to 610) are obtained within 1 m (1000 mm) form a mountain-shaped shape characteristic of a person, the information processing device 1 detects the range as the range of a person (i.e., detects the presence of a person). In the illustrated example, the six squares lined up horizontally (left and right) from the square marked SL (Shoulder Left) to the square marked SR (Shoulder Right) correspond to the shoulder range (shoulder width), and the width of the part above the shoulder range is shorter than the shoulder width.

[0039] Furthermore, the information processing device 1 detects a narrow range above the shoulder area as the face area. For example, the information processing device 1 detects a 3 (horizontal) × 4 (vertical) square above the shoulder area within the person's area as the face area. The size of this face area corresponds to the face area of ​​a person present at a distance where the information processing device 1 is being used (where keyboard operation is being performed) when distance measurement is performed with a detection range FoV of 8 × 8 squares.

[0040] The information processing device 1 may detect the 3x3 squares above the shoulder area of ​​the person as the face area. If the detection range FoV is measured using a measurement unit other than 8x8 squares, the face area is also set to a range that matches the number of measurement units, instead of 3x4 squares or 3x3 squares.

[0041] As shown in the figure, the center square of the face area is the center of the face, and the distance measurement value of the square above the center square marked FT (Face Top) is taken as the distance measurement value of the upper part of the face (forehead position). The distance measurement value of the square below the center square marked FB (Face Bottom) is taken as the distance measurement value of the lower part of the face (chin position). The distance measurement value of the square to the left of the center square marked FL (Face Left) is taken as the distance measurement value of the left part of the face. The distance measurement value of the square to the right of the center square marked FR (Face Right) is taken as the distance measurement value of the left part of the face.

[0042] If the face area is 3x3 squares, the center square of the 3x3 squares will be the square in the center of the 3x3 squares, but if the face area is 3 (horizontal) x 4 (vertical) squares, it will be either the square in the center column of the second row or the mast in the center column of the third row. Here, the lower square (the square in the third row) is given priority as the center square.

[0043] The upper cell (cell in the second row) may be prioritized as the center cell. Alternatively, the distance measurements of both cells may be tracked, and the cell with the smaller distance measurement value may be prioritized as the center cell, or the cell with the largest amount of variation (amount of movement) in the distance measurement value may be prioritized as the center cell.

[0044] The information processing device 1 determines the orientation of the face based on the distance measurements of the upper, lower, left, and right parts of the face. For example, the information processing device 1 determines the orientation of the face in the vertical direction (up and down direction) based on the difference between the distance measurements of the upper and lower parts of the face. The information processing device 1 also determines the orientation of the face in the horizontal direction (left and right direction) based on the difference between the distance measurements of the left and right parts of the face.

[0045] For example, if the difference between the distance measurement values ​​of the upper and lower parts of the face is equal to or greater than a predetermined threshold and the distance measurement value of the upper part of the face is smaller than the distance measurement value of the lower part of the face, the information processing device 1 determines that the face is facing downward. On the other hand, if the difference between the distance measurement values ​​of the upper and lower parts of the face is equal to or greater than a predetermined threshold and the distance measurement value of the lower part of the face is smaller than the distance measurement value of the upper part of the face, the information processing device 1 determines that the face is facing upward.

[0046] Furthermore, if the difference between the distance measurement values ​​for the left and right parts of the face is equal to or greater than a predetermined threshold and the distance measurement value for the left part of the face is smaller than the distance measurement value for the right part, the information processing device 1 determines that the face is facing right. On the other hand, if the difference between the distance measurement values ​​for the left and right parts of the face is equal to or greater than a predetermined threshold and the distance measurement value for the right part of the face is smaller than the distance measurement value for the left part, the information processing device 1 determines that the face is facing left.

[0047] Furthermore, if the difference between the distance measurement values ​​of the upper and lower parts of the face is less than a predetermined threshold and the difference between the distance measurement values ​​of the left and right parts of the face is less than a predetermined threshold, the information processing device 1 determines that the face is facing forward. In this way, the information processing device 1 determines whether the face is facing up or down, left or right, or forward, based on the distance measurement values ​​of the upper, lower, left, and right parts of the face, thereby determining the orientation of the face.

[0048] The information processing device 1 may determine the orientation of the face in the vertical (up-down) and horizontal (left-right) directions depending on which part of the face has the smallest distance measurement value among the upper, lower, left, and right parts. Furthermore, the information processing device 1 may determine that the face is facing forward when the difference in the distance measurement values ​​of the upper, lower, left, and right parts of the face is less than a predetermined threshold.

[0049] Here, since the difference in distance measurement values ​​between the upper, lower, left, and right parts of the face is not large, the range in which the face direction can be determined is limited to a range closer than the range in which a person can be detected. That is, even if the information processing device 1 detects a person within the detection range FoV (for example, a range of about 2 m) shown in Fig. 2 using the TOF sensor 130, the range in which the face direction of the detected person can be determined (determined) is a relatively short, narrow range (for example, a range of about 1 m). With reference to Figs. 4 to 6, the detection of a person and the determination of the face direction using the TOF sensor 130 in this embodiment will be described.

[0050] 4 is a schematic diagram showing a first example of person detection and face direction determination using the TOF sensor 130 according to the present embodiment. A range in which a person can be detected, corresponding to the detection range FoV, is shown as person detection range R1. Furthermore, a range within person detection range R1 in which the face direction can be determined is shown as face direction determination range R2. Face direction determination range R2 is a narrower range within person detection range R1 that is closer to the information processing device 1 than person detection range R1. A range within person detection range R1 outside face direction determination range R2 is a range in which a person can be detected using the TOF sensor 130, but in which the TOF sensor 130 may not be able to accurately determine the face direction.

[0051] When a person U is detected in the person detection range R1 and the detected person U is within the face direction determination range R2, the information processing device 1 determines the facial direction of the person U using the TOF sensor 130. Based on the determination result of the facial direction of the person U, the information processing device 1 determines whether or not the person U is paying attention to the information processing device 1. Hereinafter, the determination of whether or not the person U is paying attention to the information processing device 1 is referred to as "Attention determination."

[0052] When the information processing device 1 determines that the person U's face is facing forward, it determines that the person U is paying attention to the information processing device 1 and sets the determination result of the Attention determination to "Attention=True." On the other hand, when the information processing device 1 determines that the person U's face is not facing forward, it determines that the person U is not paying attention to the information processing device 1 and sets the determination result of the Attention determination to "Attention=False."

[0053] 5 is a schematic diagram showing a second example of person detection and face direction determination using the TOF sensor 130 according to the present embodiment. This diagram shows Attention determination when a person U detected in the person detection range R1 moves from within the face direction determination range R2 (see FIG. 4) to outside the face direction determination range R2. When the person U detected in the person detection range R1 moves from within the face direction determination range R2 to outside the face direction determination range R2, the information processing device 1 maintains the determination result of the face direction when determined within the face direction determination range R2, i.e., the determination result of Attention determination.

[0054] For example, if the person U who was determined to be "Attention=True" within the face direction determination range R2 moves out of the face direction determination range R2, the information processing device 1 maintains the determination result of the Attention determination as "Attention=True." Also, if the person U who was determined to be "Attention=False" within the face direction determination range R2 moves out of the face direction determination range R2, the information processing device 1 maintains the determination result of the Attention determination as "Attention=False." Note that if the person U moves further and is no longer detected within the person detection range R1, the information processing device 1 cancels the determination result of the Attention determination.

[0055] FIG. 6 is a schematic diagram showing a third example of person detection and face direction determination using the TOF sensor 130 according to the present embodiment. This diagram illustrates the Attention determination when a person U moves from outside the person detection range R1 into the person detection range R1. When the person U moves from outside the person detection range R1 into the person detection range R1 (approaching the information processing device 1) and thus the information processing device 1 detects the person U outside the face direction determination range R2 within the person detection range R1, the information processing device 1 fixes the determination result of the Attention determination to "Attention=True." Note that when the person U moves further (approaches the information processing device 1) and enters the face direction determination range R2, the information processing device 1 determines the face direction of the person U using the TOF sensor 130 as shown in FIG. 4.

[0056] [Hardware configuration of information processing device] 7 is a schematic block diagram showing an example of the hardware configuration of an information processing device 1 according to this embodiment. In this Fig. 7, components corresponding to those in Fig. 1 are assigned the same reference numerals. The information processing device 1 includes a display unit 110, a ToF sensor 130, a power button 140, an input device 150, a communication unit 160, a storage unit 170, an EC (Embedded Controller) 200, a main processing unit 300, and a power supply unit 400.

[0057] The display unit 110 displays display data (images) generated based on system processing executed by the main processing unit 300 and processing of application programs running on the system processing.

[0058] As described above, the ToF sensor 130 is a distance measurement sensor that uses the ToF method to measure the distance to an object (e.g., a person) present in front. For example, the ToF sensor 130 outputs a distance measurement signal including a distance measurement value that measures the distance to an object (e.g., a person) present in the detection range FoV in the direction facing the inner surface of the first housing 10 (forward).

[0059] The power button 140 outputs an operation signal to the EC 200 in response to a user operation. The input device 150 is an input unit that accepts user input, and is configured to include, for example, a keyboard 151 and a touchpad 153. In response to accepting an operation on the keyboard 151 and the touchpad 153, the input device 150 outputs an operation signal indicating the operation content to the EC 200.

[0060] The communication unit 160 is communicably connected to other devices via a wireless or wired communication network, and transmits and receives various types of data. For example, the communication unit 160 is configured to include a wired LAN interface such as Ethernet (registered trademark), a wireless LAN interface such as Wi-Fi (registered trademark), etc.

[0061] The storage unit 170 includes storage media such as a hard disk drive (HDD), a solid state drive (SSD), RAM, and ROM. The storage unit 170 stores various programs such as an OS, device drivers, and applications, as well as various data acquired by the operation of the programs.

[0062] The power supply unit 400 supplies power to each unit of the information processing device 1 according to the operating state of each unit. The power supply unit 400 includes a DC (Direct Current) / DC converter. The DC / DC converter converts the voltage of direct current power supplied from an AC (Alternate Current) / DC adapter or a battery (battery pack) into the voltage required by each unit. The power whose voltage is converted by the DC / DC converter is supplied to each unit via each power supply system. For example, the power supply unit 400 supplies power to each unit via each power supply system based on a control signal input from the EC 200.

[0063] The EC200 is a microcomputer including a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), and I / O (Input / Output) logic circuits. The CPU of the EC200 reads a control program (firmware) pre-stored in its own ROM, executes the read control program, and performs its functions. The EC200 operates independently of the main processing unit 300, controls the operation of the main processing unit 300, and manages its operating state. The EC200 is also connected to the power button 140, the input device 150, the power supply unit 400, and the like.

[0064] For example, the EC 200 communicates with the power supply unit 400 to acquire information on the battery status (such as remaining capacity) from the power supply unit 400, and outputs to the power supply unit 400 control signals and the like for controlling the supply of power according to the operating state of each unit of the information processing device 1. The EC 200 also acquires operation signals from the power button 140 and the input device 150, and outputs to the main processing unit 300 operation signals related to processing by the main processing unit 300 among the acquired operation signals.

[0065] The main processing unit 300 is composed of a CPU (Central Processing Unit) 301, a GPU (Graphics Processing Unit) 302, a chipset 303, and a system memory 304, and is capable of executing processing of various application programs on an OS (Operating System) through system processing based on the OS.

[0066] CPU 301 is a processor that executes processes based on BIOS programs, processes based on OS programs, and processes based on application programs that run on the OS. For example, CPU 301 executes startup processing that starts the system from a standby state and transitions it to a normal operating state, and sleep processing that transitions it from the normal operating state to a standby state. CPU 301 also executes screen brightness control processing that controls the screen brightness of display unit 110 based on the above-mentioned face orientation determination result, etc.

[0067] The GPU 302 is connected to the display unit 110. The GPU 302 generates display data by executing image processing under the control of the CPU 301. The GPU 302 outputs the generated display data to the display unit 110.

[0068] The chipset 303 has a function as a memory controller and a function as an I / O controller. For example, the chipset 303 controls the CPU 301 and the GPU 302 to read and write data from the system memory 304, the storage unit 170, etc. The chipset 303 also controls the input and output of data from the communication unit 160, the display unit 110, and the EC 200. The chipset 303 also has a function as a sensor hub. For example, the chipset 303 acquires ranging signals output from the TOF sensor 130.

[0069] The system memory 304 is used as a reading area for programs executed by the CPU 301 and a working area for writing processing data.

[0070] The CPU 301, GPU 302, and chipset 303 may be configured as a single integrated processor, or some or each may be configured as individual processors. For example, in a normal operating state, the CPU 301, GPU 302, and chipset 303 are all in operation, but in a standby state, only at least a part of the chipset 303 is in operation.

[0071] [Functional configuration of information processing device] Next, the functional configuration of the information processing device 1 that detects a person and determines the direction of the face using the TOF sensor 130 will be described in detail.

[0072] 8 is a schematic block diagram showing an example of the functional configuration of the information processing device 1 according to this embodiment. The information processing device 1 includes a detection processing unit 210 that acquires a ranging signal measured by the TOF sensor 130 and determines the direction of a person and their face, and a system processing unit 310 that performs processing based on the detection results and determination results by the detection processing unit 210. The detection processing unit 210 includes a person detection unit 211, a face area detection unit 212, a face direction determination unit 213, and a determination result output unit 215 as functional components that perform the above-mentioned person detection and face direction determination by the CPU 301, the chipset 303, or the like executing a specific program.

[0073] The person detection unit 211 performs a person detection process to detect a person present within the person detection range R1 (detection range FoV) based on the distance measurement value of the TOF sensor 130. For example, unlike objects, people move to some extent, so when detecting a person, the person detection unit 211 may exclude completely stationary objects from the detection targets and may detect only objects that are moving (for example, slight movements).

[0074] The face area detection unit 212 performs face area detection processing to detect the area of ​​the person's face when a person is detected by the person detection unit 211. For example, the face area detection unit 212 first detects the area of ​​the person, and then detects the area of ​​the face from within the area of ​​the person.

[0075] 3, the face area detection unit 212 acquires a distance measurement value for each square (measurement unit) of the detection range FoV, which is divided into 64 measurement units of 8×8 squares, based on the distance measurement signal output from the TOF sensor 130. If the edge of the range of squares where distance measurement values ​​with little difference (for example, about 450 to 610) are obtained within 1 m (1000 mm) forms a mountain shape characteristic of a person, the face area detection unit 212 detects that range as the range of a person.

[0076] Furthermore, similar to the detection of people by the person detection unit 211 described above, when detecting the range of a person, the face area detection unit 212 may exclude completely stationary objects from the detection targets and may detect only objects that are moving (for example, slight movements). For example, the face area detection unit 212 determines whether the distance measurement value of each square from the distance measurement values ​​measured at a predetermined cycle (for example, one second intervals) is that of a moving object based on the amount of variation in the distance measurement value of each square, and detects the range of a person based on the edge of the range of the square from which the distance measurement value of the moving object was obtained.

[0077] Next, the face area detection unit 212 detects the area of ​​the person's face based on the shape of the edges of the detected area of ​​the person. For example, the face area detection unit 212 detects the area of ​​the person's shoulders, and detects an area of ​​3 (horizontal) × 4 (vertical) squares or 3 × 3 squares above the shoulders as the area of ​​the face (see FIG. 3).

[0078] The face direction determination unit 213 performs face direction determination processing to determine the face direction based on distance measurement values ​​within the face range detected by the face range detection unit 212. For example, the face direction determination unit 213 determines the face direction based on the difference in distance measurement values ​​for each of a plurality of squares (measurement units) within the face range. Specifically, as described with reference to FIG. 3, the face direction determination unit 213 determines the face direction by determining whether the face is facing vertically (up and down), horizontally (left and right), or frontally based on the difference in distance measurement values ​​for the upper, lower, left, and right parts of the face. For example, the face direction determination unit 213 determines the face direction based on which part of the face range is closest based on the distance measurement values ​​for each of a plurality of squares (measurement units) within the face range.

[0079] The face direction determination unit 213 may calculate an average distance to the person based on distance measurement values ​​within the range of the person, and detect the face direction by taking the average distance to the person into consideration. For example, when calculating the difference between the distance measurement values ​​for each of a plurality of squares (measurement units) within the range of the face, the face direction determination unit 213 may detect the face direction using the difference from the average distance to the person.

[0080] Here, when the person detected by the person detection unit 211 is within the face direction determination range R2, the face direction determination unit 213 determines the face direction based on the distance measurement value by the TOF sensor 130 as described above (see FIG. 4). On the other hand, when the person detected by the person detection unit 211 is outside the face direction determination range R2, the face direction determination unit 213 does not determine the face direction based on the distance measurement value because there is a possibility that the determination cannot be made accurately due to an error in the distance measurement value.

[0081] For example, when a person detected by the person detection unit 211 moves from within the face direction determination range R2 to outside the face direction determination range R2, the face direction determination unit 213 maintains the determination result of the face direction determined within the face direction determination range R2 (see FIG. 5). Also, when the person detection unit 211 detects a person outside the face direction determination range R2 within the person detection range R1 after a state in which no person has been detected within the person detection range R1, the face direction determination unit 213 fixes the determination result of the face direction to a preset one (see FIG. 6). The preset face direction refers to, for example, a state in which the face is facing forward.

[0082] Furthermore, when the person detected by the person detection unit 211 moves from within the face direction determination range R2 to outside the face direction determination range R2, the face direction determination unit 213 maintains the determination result of the face direction determined within the face direction determination range R2, and then when the person detected by the person detection unit 211 moves again into the face direction determination range R2, the face direction determination unit 213 cancels the maintenance of the determination result and determines the face direction of the person using the TOF sensor 130 (see FIG. 4).

[0083] Furthermore, if the person detected by the person detection unit 211 moves from within the face direction determination range R2 to outside the face direction determination range R2 and thus the person has maintained the determination result of the face direction determined within the face direction determination range R2, and then the person detection unit 211 no longer detects a person within the person detection range R1, the face direction determination unit 213 cancels the maintenance of the determination result and terminates the face direction determination process.

[0084] Furthermore, after the face direction determination unit 213 fixes the determination result of the face direction when the person detection unit 211 detects a person outside the face direction determination range R2 within the person detection range R1 from a state in which no person is detected within the person detection range R1, when the person detected by the person detection unit 211 moves from outside the face direction determination range R2 to within the face direction determination range R2, the face direction determination unit 213 releases the fixation of the determination result and determines the face direction of the person using the TOF sensor 130.

[0085] Furthermore, after the face direction determination unit 213 fixes the determination result of the face direction due to the fact that the person detection unit 211 has detected a person outside the face direction determination range R2 within the person detection range R1, if the person detection unit 211 returns to a state where no person is detected within the person detection range R1, the face direction determination unit 213 releases the fixation of the determination result and terminates the face direction determination process.

[0086] The determination result output unit 215 outputs information based on the face direction detected by the face direction determination unit 213 to the system processing unit 310. For example, when the determination result output unit 215 determines that the face direction detected by the face direction determination unit 213 is facing forward, the person is in a state of paying attention to the information processing device 1, and therefore outputs "Attention=True" as the determination result of the Attention determination. On the other hand, when the determination result output unit 215 determines that the face direction of the person detected by the face direction determination unit 213 is not facing forward, the person is in a state of not paying attention to the information processing device 1, and therefore outputs "Attention=False" as the determination result of the Attention determination.

[0087] The determination result output unit 215 may output information indicating the face direction as information based on the face direction detected by the face direction determination unit 213. The information indicating the face direction is, for example, facing forward, facing upward, facing downward, facing left, facing right, etc.

[0088] The system processing unit 310 is a functional configuration realized by the CPU 11 executing the BIOS and OS programs. For example, the system processing unit 310 includes a screen brightness control unit 311 and a timer 312 as functional configurations realized by the CPU 11 executing the OS programs.

[0089] The screen brightness control unit 311 controls the screen brightness of the display unit 110 based on the direction of the face detected by the detection processing unit 210. For example, when the screen brightness control unit 311 acquires "Attention=False" from the detection processing unit 210 in a normal operating state, it controls the screen brightness to low.

[0090] Furthermore, when the screen brightness control unit 311 acquires "Attention=True" from the detection processing unit 210 while the screen brightness is controlled to low brightness, the screen brightness control unit 311 returns the screen brightness to standard brightness. That is, when the detection processing unit 210 detects that the face is facing forward while the screen brightness is reduced, the screen brightness control unit 311 returns the screen brightness to the standard brightness before it was reduced.

[0091] The timer 312 is a timer that measures the waiting time from when "Attention=False" is acquired from the detection processing unit 210 in a normal operating state until the screen brightness is controlled to low brightness. If the screen brightness control unit 311 acquires "Attention=True" before a predetermined waiting time has elapsed even after acquiring "Attention=False," the screen brightness control unit 311 does not control the screen brightness to low brightness and keeps it at standard brightness. If the screen brightness control unit 311 does not acquire "Attention=True" within the predetermined waiting time after acquiring "Attention=False," the screen brightness control unit 311 controls the screen brightness to low brightness. This prevents the screen brightness from being reduced to low brightness even if the user looks away for a moment while using the information processing device 1. The predetermined waiting time is preset to, for example, 10 seconds. Note that this predetermined waiting time may be configured to be user-configurable.

[0092] [Face direction determination processing] Next, with reference to FIG. 9, the operation of the face direction determination process in which the information processing device 1 detects the direction of the face using the TOF sensor 130 will be described.

[0093] FIG. 9 is a flowchart showing an example of the face direction determination process according to this embodiment. (Step S101) The detection processing unit 210 acquires the distance measurement signal output from the TOF sensor 130 at a predetermined cycle, and performs a person detection process to detect a person present within the person detection range R1 based on the distance measurement value of the TOF sensor 130. For example, the detection processing unit 210 detects a person present within the person detection range R1 based on the distance measurement value of an object that is moving (e.g., slightly moving). Then, the process proceeds to step S103.

[0094] (Step S103) The detection processing unit 210 determines whether or not a person has been detected in the person detection processing of step S101. If the detection processing unit 210 determines that a person has not been detected (NO), it continues the processing of step S101 and continues the person detection processing. On the other hand, if the detection processing unit 210 determines that a person has been detected (YES), it proceeds to the processing of step S105.

[0095] (Step S105) The detection processing unit 210 determines whether the person detected in the person detection processing of step S101 is within the face direction determination range R2. If the detection processing unit 210 determines that the detected person is within the face direction determination range R2 (YES), the process proceeds to step S107. On the other hand, if the detection processing unit 210 determines that the detected person is outside the face direction determination range R2 (NO), the process proceeds to step S111.

[0096] (Step S107) The detection processing unit 210 determines the orientation of the face using the distance measurement value obtained by the TOF sensor 130. For example, as described with reference to Fig. 3, the detection processing unit 210 detects the area of ​​the person's face based on the shape of the edges of the area of ​​the detected person, and determines the orientation of the face based on the distance measurement value within the area of ​​the face. Then, the process proceeds to step S109.

[0097] (Step S109) The detection processing unit 210 outputs information based on the face direction determined in step S107 to the system processing unit 310 as a determination result. For example, the detection processing unit 210 outputs a determination result of the Attention determination to the system processing unit 310 based on the face direction determined in step S107. As an example, if the detected face direction is forward, the detection processing unit 210 outputs "Attention=True" to the system processing unit 310. On the other hand, if the detected face direction is not forward, the detection processing unit 210 outputs "Attention=False" to the system processing unit 310.

[0098] (Step S111) If the person detected in the person detection process of step S101 is outside the face direction determination range R2, the detection processing unit 210 determines whether or not the person was within the face direction determination range R2 before going outside the face direction determination range R2. If the detection processing unit 210 determines that the person was within the face direction determination range R2 before going outside the face direction determination range R2 (YES), the process proceeds to step S113. On the other hand, if the detection processing unit 210 determines that the person was not within the face direction determination range R2 before going outside the face direction determination range R2 (NO), the process proceeds to step S115.

[0099] (Step S113) The detection processing unit 210 maintains the previous determination result because the person detected in the person detection range R1 has moved from within the face direction determination range R2 to outside the face direction determination range R2. For example, if the person that the detection processing unit 210 had determined as "Attention=True" within the face direction determination range R2 has moved outside the face direction determination range R2, the detection processing unit 210 maintains the determination result and outputs "Attention=True" to the system processing unit 310. Furthermore, if the person that the information processing device 1 had determined as "Attention=False" within the face direction determination range R2 has moved outside the face direction determination range R2, the information processing device 1 maintains the determination result and outputs "Attention=False" to the system processing unit 310.

[0100] (Step S115) If the detection processing unit 210 was not within the face direction determination range R2 before going outside the face direction determination range R2, that is, if the person was outside the person detection range R1 before going outside the face direction determination range R2, the detection processing unit 210 fixes the determination result as "Attention=True" and outputs it to the system processing unit 310.

[0101] [Screen brightness control processing] Next, the operation of the screen brightness control process executed by the system processing unit 310 will be described with reference to Fig. 10. Fig. 10 is a flowchart showing an example of the screen brightness control process according to this embodiment. Here, it is assumed that the information processing device 1 is in a normal operating state, a person (user) is facing forward, and the screen brightness is set to standard brightness.

[0102] (Step S201) The screen brightness control unit 311 determines whether or not "Attention=False" has been acquired from the detection processing unit 210. If the screen brightness control unit 311 determines that "Attention=False" has not been acquired (NO), it performs the process of step S201 again. On the other hand, if the screen brightness control unit 311 determines that "Attention=False" has been acquired (YES), it starts counting the waiting time using the timer 312 (step S203). Then, the process proceeds to step S205.

[0103] (Step S205) The screen brightness control unit 311 determines whether or not "Attention=True" has been acquired from the detection processing unit 210. When the screen brightness control unit 311 determines that "Attention=True" has not been acquired (NO), the process proceeds to step S207.

[0104] (Step S207) The screen brightness control unit 311 determines whether a predetermined waiting time (e.g., 10 seconds) has elapsed (i.e., whether the timer has expired) based on the value of the timer 312. If the screen brightness control unit 311 determines that the predetermined waiting time (e.g., 10 seconds) has not elapsed (i.e., the timer has not expired) (step S207: NO), the process returns to step S205. If the screen brightness control unit 311 determines that "Attention=True" has been acquired before the predetermined waiting time (e.g., 10 seconds) has elapsed (step S205: YES), the process returns to step S201. At this time, the timer 312 is reset.

[0105] On the other hand, if it is determined in step S207 that the predetermined waiting time (for example, 10 seconds) has elapsed (step S207: YES), screen brightness control unit 311 changes the screen brightness to low brightness (step S209), and then proceeds to the processing of step S211.

[0106] (Step S211) The screen brightness control unit 311 determines whether or not "Attention=True" has been acquired from the detection processing unit 210. If the screen brightness control unit 311 determines that "Attention=True" has not been acquired (NO), it performs the process of step S211 again. On the other hand, if the screen brightness control unit 311 determines that "Attention=True" has been acquired (YES), it returns the screen brightness to standard brightness (step S213).

[0107] [Summary of the embodiment] As described above, the information processing device 1 according to this embodiment includes a TOF sensor 130 (an example of a distance measurement sensor) that measures the distance to an object, a system memory 304 (an example of a memory) that temporarily stores a distance measurement value (an example of distance information) indicating the distance measured by the TOF sensor 130, and a processor (e.g., a CPU 301, a chipset 303, etc.) that executes processing (e.g., a person detection process, a face direction determination process, etc.) based on the distance measurement value. In the person detection process, the information processing device 1 detects a person present within a first distance range (e.g., a person detection range R1) using the TOF sensor 130. In the face direction determination process, when a person is detected within the person detection range R1 by the person detection process, the information processing device 1 determines the face direction of the person. For example, in the face direction determination process, when a person detected by the person detection process is within a second distance range (e.g., a face direction determination range R2) that is closer than the first distance, the information processing device 1 determines the face direction of the person using the TOF sensor 130. Furthermore, in the face direction determination process, if a person detected by the person detection process moves from within the face direction determination range R2 to outside the face direction determination range R2, the information processing device 1 maintains the determination result of the face direction determined within the face direction determination range R2. Furthermore, in the face direction determination process, if a person is detected outside the face direction determination range R2 within the person detection range R1 after a state in which no person was detected within the person detection range R1 by the person detection process, the information processing device 1 fixes the determination result of the face direction (for example, facing forward relative to the information processing device 1) to a preset value.

[0108] This prevents the information processing device 1 from producing unstable changes in the determination result near the boundary of the range of distances in which the face orientation can be determined, thereby improving the stability of control using the TOF sensor 130.

[0109] Furthermore, in the face direction determination process, when a person detected by the person detection process moves from within the face direction determination range R2 to outside the face direction determination range R2, the information processing device 1 maintains the determination result of the face direction determined within the face direction determination range R2, and then when the person detected by the person detection process moves again into the face direction determination range R2, the information processing device 1 cancels the maintenance of the determination result and determines the face direction of the person using the TOF sensor 130.

[0110] As a result, even if the face direction determination result is not updated because the person has moved outside the face direction determination range R2, the information processing device 1 can resume determining the face direction simply by moving closer to the face direction determination range R2.

[0111] Furthermore, in the face direction determination process, if a person detected by the person detection process moves from within the face direction determination range R2 to outside the face direction determination range R2 and the person is then detected within the person detection range R1 by the person detection process, the information processing device 1 releases the maintenance of the determination result and terminates the face direction determination process.

[0112] As a result, when the person leaves and becomes absent, the information processing device 1 does not need to determine the direction of the face, and therefore can terminate the face direction determination process.

[0113] Furthermore, in the face direction determination process, the information processing device 1 fixes the determination result of the face direction when a person is detected outside the face direction determination range R2 within the person detection range R1 from a state in which no person is detected within the person detection range R1 by the person detection process, and then when the person detected by the person detection process moves from outside the face direction determination range R2 to within the face direction determination range R2, the information processing device 1 releases the fixation of the determination result and determines the face direction of the person using the TOF sensor 130.

[0114] As a result, when a person approaches, the information processing device 1 can detect the person as the person using the information processing device 1 even if the person is at a distance where the direction of the face cannot be determined.

[0115] Furthermore, in the face direction determination process, if the information processing device 1 fixes the face direction determination result due to the detection of a person outside the face direction determination range R2 within the person detection range R1 after the state in which no person was detected within the person detection range R1 by the person detection process changes to a state in which no person is detected within the person detection range R1 by the person detection process, then the information processing device 1 releases the fixation of the determination result and terminates the face direction determination process.

[0116] As a result, when the person leaves and becomes absent, the information processing device 1 does not need to determine the direction of the face, and therefore can terminate the face direction determination process.

[0117] In addition, in the face direction determination process, the information processing device 1 determines whether the face direction of a person detected within the person detection range R1 by the person detection process is facing toward the information processing device 1, and when fixing the face direction determination result to a preset value, fixes it to the determination result that the person's face direction is facing toward the information processing device 1 (for example, "Attention=True").

[0118] As a result, when a person approaches, the information processing device 1 can detect the person as the person using the information processing device 1 even if the person is at a distance where the direction of the face cannot be determined.

[0119] Furthermore, the information processing device 1 performs a screen brightness control process for controlling the screen brightness of the display unit 110 based on the face direction determined by the face direction determination process.

[0120] This allows the information processing device 1 to reduce or turn off the screen brightness when, for example, the user is not facing forward, thereby preventing unnecessary power consumption during periods when the device is not in use.

[0121] Furthermore, the control method in the information processing device 1 according to this embodiment includes a person detection step in which a processor (e.g., CPU 301, chipset 303, etc.) detects a person present within a first distance range (e.g., person detection range R1) using the TOF sensor 130, and a face direction determination step in which, when a person is detected within the person detection range R1 by the person detection step, a face direction of the person is determined. In the face direction determination step, when a person detected by the person detection processing is within a second distance range (e.g., face direction determination range R2) that is closer than the first distance, the face direction of the person is determined using the TOF sensor 130. When the person detected by the person detection step moves from within the face direction determination range R2 to outside the face direction determination range R2, the determination result of the face direction determined within the face direction determination range R2 is maintained. When a person is detected outside the face direction determination range R2 within the person detection range R1 after a state in which no person was detected within the person detection range R1 by the person detection step, the determination result of the face direction (e.g., facing forward relative to the information processing device 1) is fixed to a preset face direction (e.g., facing forward relative to the information processing device 1).

[0122] As a result, the control method in the information processing device 1 can improve the stability of control using the TOF sensor 130, since the determination results do not change unstably near the boundary of the distance range in which the face orientation can be determined.

[0123] Although the embodiments of the present invention have been described above in detail with reference to the drawings, the specific configurations are not limited to the above-described embodiments, and the present invention also includes designs that do not deviate from the gist of the present invention. For example, the configurations described in the above-described embodiments can be combined in any manner.

[0124] Furthermore, in the above embodiment, the information processing device 1 detected the orientation of the face using distance measurement values ​​of four squares within the range of the detected face: the top, bottom, left, and right sides of the face; however, the orientation of the face (upward, downward, forward) may also be detected using distance measurement values ​​of two squares at the top and bottom of the face, or the orientation of the face (leftward, right, forward) may also be detected using distance measurement values ​​of two squares at the left and right sides of the face.

[0125] Furthermore, the information processing device 1 may detect the orientation of the face using distance measurement values ​​from five or more squares within the range of the detected face (for example, a 3x4 square, a 3x3 square). For example, the information processing device 1 may detect the orientation of the face using distance measurement values ​​from five squares within the range of the detected face: the center, top, bottom, left, and right sides of the face. Furthermore, the information processing device 1 may detect the orientation of the face using distance measurement values ​​from eight squares around the center of the face within the range of the detected face, or may detect the orientation of the face using distance measurement values ​​from nine squares, including the distance measurement value from the center of the face.

[0126] Furthermore, in the above embodiment, a configuration example in which the ToF sensor 130 is built into the information processing device 1 has been described, but the present invention is not limited to this. For example, the ToF sensor 130 does not have to be built into the information processing device 1, but may be configured to be attachable to the information processing device 1 (for example, any one of the side surfaces 10a, 10b, 10c, etc.) as an external accessory of the information processing device 1, and may be communicatively connected to the information processing device 1 wirelessly or via a wire.

[0127] In the above embodiment, the TOF sensor 130 using infrared rays has been described as an example of a distance measurement sensor, but the present invention is not limited to this. For example, a distance measurement sensor using a laser or ultrasonic waves may also be used.

[0128] The above-mentioned standby state may include a hibernation state, a power-off state, etc. The hibernation state corresponds to, for example, the S4 state defined by ACPI. The power-off state corresponds to, for example, the S5 state (shutdown state) defined by ACPI. Among the standby states, the standby state, sleep state, hibernation state, and power-off state are states in which power consumption is lower (states in which power consumption is reduced) than in the normal operating state.

[0129] The information processing device 1 described above includes an internal computer system. A program for implementing the functions of each component of the information processing device 1 may be recorded on a computer-readable recording medium, and the program may be loaded into a computer system and executed to perform processing in each component of the information processing device 1. Here, "loading a program recorded on a recording medium into a computer system and executing it" includes installing the program into a computer system. The term "computer system" here includes hardware such as an OS and peripheral devices. The term "computer system" may also include multiple computer devices connected via a network, including the Internet, a WAN, a LAN, a dedicated line, or other communication lines. The term "computer-readable recording medium" refers to portable media such as a flexible disk, a magneto-optical disk, a ROM, a CD-ROM, or a storage device such as a hard disk built into a computer system. The recording medium storing the program may also be a non-transitory recording medium such as a CD-ROM.

[0130] The recording medium also includes internal or external recording media accessible from a distribution server for distributing the program. The program may be divided into multiple parts, downloaded at different times, and then combined by the components of the information processing device 1, or each divided program may be distributed by a different distribution server. Furthermore, the term "computer-readable recording medium" also includes a medium that stores a program for a certain period of time, such as volatile memory (RAM) within a computer system that serves as a server or client when a program is transmitted over a network. The program may also be a medium that realizes part of the above-described functions. Furthermore, the program may be a so-called differential file (differential program) that can realize the above-described functions in combination with a program already stored in the computer system.

[0131] Furthermore, some or all of the functions of the information processing device 1 in the above-described embodiment may be realized as an integrated circuit such as an LSI (Large Scale Integration). Each function may be individually implemented as a processor, or some or all of the functions may be integrated into a processor. The integrated circuit method is not limited to LSI, and may be implemented using a dedicated circuit or a general-purpose processor. Furthermore, if an integrated circuit technology that can replace LSI emerges due to advances in semiconductor technology, an integrated circuit based on that technology may be used.

[0132] Furthermore, the information processing device 1 of the above embodiment is not limited to a notebook PC, but may be, for example, a desktop PC, a tablet terminal device, a smartphone, a game device, a multimedia terminal, or the like. [Explanation of symbols]

[0133] 1 Information processing device, 10 First housing, 20 Second housing, 15 Hinge mechanism, 110 Display unit, 130 ToF sensor, 140 Power button, 150 Input device, 151 Keyboard, 153 Touchpad, 160 Communication unit, 170 Memory unit, 200 EC, 210 Detection processing unit, 211 Person detection unit, 212 Face range detection unit, 213 Face direction determination unit, 215 Determination result output unit, 300 Main processing unit, 301 CPU, 302 GPU, 303 Chipset, 304 System memory, 310 System processing unit, 311 Screen brightness control unit, 312 Timer, 400 Power supply unit

Claims

1. a distance measuring sensor for measuring the distance to an object; a memory for temporarily storing distance information indicating the distance measured by the distance measuring sensor; a processor that performs processing based on the distance information; Equipped with The processor: a person detection process for detecting a person present within a first distance range using the distance measuring sensor; a face direction determination process for determining a face direction of a person when the person is detected within the range of the first distance by the person detection process; and In the face direction determination process, When the person detected by the person detection process is within a range of a second distance that is closer than the first distance, the distance measuring sensor is used to determine the direction of the face of the person; When the person detected by the person detection process moves from within the range of the second distance to outside the range of the second distance, the determination result of the face direction determined within the range of the second distance is maintained; When a person is detected outside the second distance range within the first distance range after a state in which no person is detected within the first distance range by the person detection process, the face direction determination result is fixed to a predetermined value. Information processing device.

2. The processor: In the face direction determination process, a determination result of the face orientation determined within the second distance range is maintained when the person detected by the person detection process moves from within the second distance range to outside the second distance range, and then when the person detected by the person detection process moves again within the second distance range, the maintenance of the determination result is released and the face orientation of the person is determined using the distance measuring sensor; The information processing device according to claim 1 .

3. The processor: In the face direction determination process, and after maintaining the determination result of the face direction determined within the second distance range due to the person detected by the person detection process moving from within the second distance range to outside the second distance range, when a state occurs in which no person is detected within the first distance range by the person detection process, canceling the maintenance of the determination result and terminating the face direction determination process. The information processing device according to claim 1 .

4. The processor: In the face direction determination process, a determination result of a face direction is fixed when a person is detected outside a second distance range within the first distance range from a state in which no person is detected within the first distance range by the person detection process, and then when the person detected by the person detection process moves from outside the second distance range to within the second distance range, the fixation of the determination result is released and the distance measuring sensor is used to determine the face direction of the person. The information processing device according to claim 1 .

5. The processor: In the face direction determination process, and after fixing the determination result of the face direction due to a person being detected outside the second distance range within the first distance range from a state in which no person has been detected within the first distance range by the person detection process, when the state returns to a state in which no person has been detected within the first distance range by the person detection process, canceling the fixation of the determination result and terminating the face direction determination process. The information processing device according to claim 1 .

6. The processor: In the face direction determination process, it is determined whether or not the face direction of the person detected within the range of the first distance by the person detection process is facing toward the information processing device; When fixing the face direction to a predetermined determination result, the face direction is fixed to a determination result that the face direction of the person is facing the direction of the information processing device. The information processing device according to claim 1 .

7. The processor: performing a screen brightness control process for controlling the screen brightness of a display unit based on the face direction determined by the face direction determination process; The information processing device according to claim 1 .

8. A control method for an information processing device including a distance measuring sensor that measures a distance to an object, a memory that temporarily stores distance information indicating the distance measured by the distance measuring sensor, and a processor that executes processing based on the distance information, comprising: the processor: a person detection step of detecting a person present within a first distance range using the distance measurement sensor; a face direction determination step of determining a direction of a face of a person detected within the range of the first distance by the person detection step; Including, In the face direction determination step, When the person detected by the person detecting step is within a range of a second distance that is closer than the first distance, determining a face direction of the person using the distance measuring sensor; When the person detected by the person detection step moves from within the range of the second distance to outside the range of the second distance, the determination result of the face direction determined within the range of the second distance is maintained; When a person is detected outside the second distance range within the first distance range after a state in which no person is detected within the first distance range in the person detection step, the face direction determination result is fixed to a predetermined value. Control method.

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