Information processing device and control method

Abstract

To more appropriately control screen brightness using the ToF method. [Solution] The information processing device divides a predetermined detection range into multiple measurement units and comprises a first sensor for measuring the distance to an object for each measurement unit, a second sensor for detecting the angle of the first sensor relative to a predetermined reference direction, and a processor that performs processing based on distance information for each measurement unit.The information processing device performs a person detection process that detects the range of a person present within the detection range based on the distance information for each measurement unit, a face direction determination process that determines the direction of the person's face based on distance information for each measurement unit within the range of a person detected within the detection range, and a screen brightness reduction process that reduces the screen brightness of the display unit based on the detection results of the person detection process and the face direction determination process.If the angle detected using the second sensor is equal to or greater than a predetermined threshold, the control content of the face direction determination process is changed based on the size of the range of a person detected within the detection range by the person detection process.

Description

[Technical Field]

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

[0002] In recent years, advances in computer vision and other technologies have improved the accuracy of detecting faces from images captured by cameras, and people are now being detected using face detection. Face detection not only detects people but also detects the orientation of their faces, making it possible to control the device based on the orientation of the face (whether the person is facing forward, facing sideways, etc.). For example, if the person's face is facing sideways, the screen brightness is reduced to prevent unnecessary power consumption during periods when the user is not using the device.

[0003] However, the above-mentioned face detection and face orientation detection using a camera requires a large development load related to image recognition, etc., and also consumes a lot of power because it is necessary to capture an image using a camera. For this reason, a simple method using a ToF (Time of Flight) system has been disclosed that reduces power consumption and detects the orientation of a person's face (see, for example, Patent Document 1). [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] However, the ToF method uses a ranging sensor to measure distance by dividing the detection range into 8 x 8 squares, which limits the detection resolution and Field of View (FoV) compared to face detection using a camera. Therefore, depending on the usage situation, only part of the user's body may be within the FoV, which may result in an unexpected reduction in screen brightness. For example, when a clamshell (notebook) personal computer is used with the computer wide open (with a large hinge angle) or when the user's posture is poor, there is a concern that the screen brightness may be reduced accidentally even when the user is using the computer.

[0006] 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 more appropriately control screen brightness using the ToF method. [Means for solving the problem]

[0007] 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 first sensor for dividing a predetermined detection range into a plurality of measurement units and measuring a distance to an object for each of the measurement units; a second sensor for detecting an angle of the first sensor relative to a predetermined reference direction; a memory for temporarily storing distance information indicating the distance for each of the measurement units measured by the first sensor; and a processor for executing processing based on the distance information for each of the measurement units, wherein the processor performs a person detection process for detecting a range of a person present within the detection range based on the distance information for each of the measurement units; a face direction determination process for determining the direction of the person's face based on the distance information for each of the measurement units within the range of the person detected within the detection range; and a screen brightness reduction process for reducing the screen brightness of a display unit based on detection results from the person detection process and the face direction determination process, and if the angle detected using the second sensor is equal to or greater than a predetermined threshold, changes the control content of the face direction determination process based on the size of the range of the person detected within the detection range by the person detection process.

[0008] In the above information processing device, the processor may enable the screen brightness reduction process when the angle detected using the second sensor is less than a predetermined threshold, disable the screen brightness reduction process when the angle detected using the second sensor is equal to or greater than a predetermined threshold and no range of a person is detected within the detection range by the person detection process, and enable the screen brightness reduction process and reduce the screen brightness of the display unit based on the detection result of the face direction determination process.

[0009] In the above information processing device, when the angle detected using the second sensor is equal to or greater than a predetermined threshold and a range of a person is detected within the detection range by the person detection process, if the size of the range of the detected person is within a predetermined first range, the processor may determine by the face direction determination process whether the orientation of the face is in a first direction that is forward relative to the information processing device, fix the detection result of the face direction by the face direction determination process to the first direction if the size of the range of the detected person is outside the first range, and reduce the screen brightness of the display unit by the screen brightness reduction process if the detection result of the face direction by the face direction determination process is not in the first direction.

[0010] In the information processing device, the processor may, based on the distance information for each measurement unit of the range of the person detected by the person detection processing, determine that the direction is the first direction when the face direction determination processing detects that the direction of the face is within a first direction range that includes the first direction if the distance to the person is less than a predetermined distance; determine that the direction is the first direction when the face direction determination processing detects that the direction of the face is within a second direction range that is wider than the first direction range if the distance to the person is equal to or greater than the predetermined distance; and determine that the direction is the first direction when the angle detected using the second sensor is equal to or greater than a predetermined threshold and the size of the range of the person detected by the person detection processing is within the first range, if the size of the range of the person is smaller than a predetermined threshold within the first range, even if the distance to the person detected by the person detection processing is less than the predetermined distance, when the face direction determination processing detects that the direction of the face is within the second direction range.

[0011] The above-mentioned information processing device may include a first housing in which the first sensor is provided, a second housing, and a rotation mechanism that rotatably connects the first housing and the second housing from a closed first state in which a first surface of the first housing and a second surface of the second housing face each other and overlap, to an open second state in which the first surface and the second surface do not overlap, and the second sensor may be a sensor for detecting an opening degree corresponding to the rotation of the first housing and the second housing as an angle of the first sensor with respect to the reference direction.

[0012] In the information processing device, the second sensor may be a sensor for detecting an angle of the first sensor with respect to a vertical direction as the angle of the first sensor with respect to the reference direction.

[0013] An information processing device according to a second aspect of the present invention includes a first sensor for dividing a predetermined detection range into a plurality of measurement units and measuring a distance to an object for each of the measurement units; a second sensor for detecting an angle of the first sensor with respect to a preset reference direction; a memory for temporarily storing distance information indicating the distance for each of the measurement units measured by the first sensor; and a processor for executing processing based on the distance information for each of the measurement units, wherein the processor performs a person detection process for detecting a range of a person present within the detection range based on the distance information for each of the measurement units; and performs a face direction determination process for determining the direction of the person's face and a screen brightness reduction process for reducing the screen brightness of the display unit, and when the angle detected using the second sensor is less than a predetermined threshold, performs the screen brightness reduction process based on the detection results of the person detection process and the face direction determination process, and when the angle detected using the second sensor is equal to or greater than a predetermined threshold, disables the screen brightness reduction process when a person's range is not detected within the detection range by the person detection process, and performs the screen brightness reduction process to reduce the screen brightness of the display unit based on the detection result of the face direction determination process when a person's range is detected within the detection range by the person detection process.

[0014] An information processing device according to a third aspect of the present invention includes a first sensor for dividing a predetermined detection range into a plurality of measurement units and measuring a distance to an object for each of the measurement units, a memory for temporarily storing distance information indicating the distance for each of the measurement units measured by the first sensor, and a processor for executing processing based on the distance information for each of the measurement units, wherein the processor performs a person detection process for detecting a range of a person present within the detection range based on the distance information for each of the measurement units, a face direction determination process for determining a direction of the person's face based on the distance information for each of the measurement units in the range of the person detected within the detection range, and and a screen brightness reduction process that reduces the screen brightness of the display unit based on the detection results of the person detection process and the face direction determination process, and when the size of the range of the person detected by the person detection process is within a predetermined first range, the face direction determination process determines whether the direction of the face is a first direction that is forward relative to the information processing device, and when the size of the range of the detected person is outside the first range, the detection result of the face direction by the face direction determination process is fixed to the first direction, and when the detection result of the face direction by the face direction determination process is not the first direction, the screen brightness of the display unit is reduced by the screen brightness reduction process.

[0015] Further, an information processing device according to a fourth aspect of the present invention includes a first sensor for dividing a predetermined detection range into a plurality of measurement units and measuring a distance to an object for each of the measurement units, a memory for temporarily storing distance information indicating the distance for each of the measurement units measured by the first sensor, and a processor for executing processing based on the distance information for each of the measurement units, wherein the processor performs a person detection process for detecting a range of a person present within the detection range based on the distance information for each of the measurement units, a face direction determination process for determining a direction of the person's face based on the distance information for each of the measurement units in the range of the person detected within the detection range, and a screen brightness reduction process for reducing the screen brightness of a display unit based on detection results from the person detection process and the face direction determination process, and When the distance to the person is less than a predetermined distance based on the distance information for each measurement unit of the range of the person detected, the face direction determination process determines that the direction is the first direction when it is detected by the face direction determination process that the direction of the face is within a first direction range including a first direction that is directly in front of the information processing device itself; when the distance to the person is equal to or greater than the predetermined distance, the face direction determination process determines that the direction is the first direction when it is detected by the face direction determination process that the direction of the face is within a second direction range that is wider than the first direction range; and when the size of the range of the person detected by the person detection process is smaller than a predetermined threshold, the face direction determination process determines that the direction is the first direction when it is detected by the face direction determination process that the direction of the face is within the second direction range even if the distance to the person detected by the person detection process is less than the predetermined distance.

[0016] Furthermore, according to a fifth aspect of the present invention, there is provided a control method for an information processing device including: a first sensor for dividing a predetermined detection range into a plurality of measurement units and measuring a distance to an object for each of the measurement units; a second sensor for detecting an angle of the first sensor relative to a predetermined reference direction; a memory for temporarily storing distance information indicating the distance for each of the measurement units measured by the first sensor; and a processor for executing processing based on the distance information for each of the measurement units. The control method includes the steps of: performing, by the processor, a person detection process for detecting a range of a person present within the detection range based on the distance information for each of the measurement units; performing a face direction determination process for determining the direction of the person's face based on the distance information for each of the measurement units within the range of the person detected within the detection range; performing a screen brightness reduction process for reducing the screen brightness of a display unit based on detection results from the person detection process and the face direction determination process; and, if the angle detected using the second sensor is equal to or greater than a predetermined threshold, changing control content of the face direction determination process based on the size of the range of the person detected within the detection range by the person detection process.

[0017] Further, according to a sixth aspect of the present invention, there is provided a control method for an information processing device including a first sensor for dividing a predetermined detection range into a plurality of measurement units and measuring a distance to an object for each of the measurement units, a second sensor for detecting an angle of the first sensor with respect to a preset reference direction, a memory for temporarily storing distance information indicating the distance for each of the measurement units measured by the first sensor, and a processor for executing processing based on the distance information for each of the measurement units, the method comprising the steps of: performing a person detection process by the processor to detect a range of a person present within the detection range based on the distance information for each of the measurement units; The method includes a step of performing a face direction determination process to determine the direction of a person's face based on distance information, and a step of performing a screen brightness reduction process to reduce the screen brightness of a display unit based on the detection results of the person detection process and the face direction determination process when the angle detected using the second sensor is less than a predetermined threshold, wherein if the angle detected using the second sensor is equal to or greater than a predetermined threshold and no range of a person is detected within the detection range by the person detection process, the screen brightness reduction process is disabled, and if a range of a person is detected within the detection range by the person detection process, the screen brightness reduction process is reduced based on the detection results of the face direction determination process.

[0018] Furthermore, according to a seventh aspect of the present invention, there is provided a control method for an information processing device including a first sensor for dividing a predetermined detection range into a plurality of measurement units and measuring a distance to an object for each of the measurement units, a memory for temporarily storing distance information indicating the distance for each of the measurement units measured by the first sensor, and a processor for executing processing based on the distance information for each of the measurement units, the control method including the steps of: performing a person detection process by the processor to detect a range of a person present within the detection range based on the distance information for each of the measurement units; and performing a face direction determination process to determine a direction of the person's face based on the distance information for each of the measurement units within the range of the person detected within the detection range. and performing a screen brightness reduction process of reducing the screen brightness of a display unit based on the detection results of the person detection process and the face direction determination process, wherein when the size of the range of the person detected by the person detection process is within a predetermined first range, the face direction determination process determines whether the direction of the face is in a first direction that is forward relative to the information processing device, and when the size of the range of the detected person is outside the first range, the detection result of the face direction by the face direction determination process is fixed to the first direction, and when the detection result of the face direction by the face direction determination process is not in the first direction, the screen brightness of the display unit is reduced by the screen brightness reduction process.

[0019] Furthermore, according to an eighth aspect of the present invention, there is provided a control method for an information processing device including a first sensor for dividing a predetermined detection range into a plurality of measurement units and measuring a distance to an object for each of the measurement units, a memory for temporarily storing distance information indicating the distance for each of the measurement units measured by the first sensor, and a processor for executing processing based on the distance information for each of the measurement units, the control method including the steps of: performing, by the processor, a person detection process for detecting a range of a person present within the detection range based on the distance information for each of the measurement units; a face direction determination process for determining a face orientation of the person based on the distance information for each of the measurement units in the range of the person detected within the detection range; and a screen brightness reduction process for reducing the screen brightness of a display unit based on detection results from the person detection process and the face direction determination process, Based on the distance information for each measurement unit of the range of the person detected by the person detection processing, if the distance to the person is less than a predetermined distance, the face direction determination processing determines that the direction of the face is the first direction when it detects that the direction of the face is within a first direction range that includes a first direction that is directly in front of the information processing device; if the distance to the person is equal to or greater than the predetermined distance, the face direction determination processing determines that the direction of the face is the first direction when it detects that the direction of the face is within a second direction range that is wider than the first direction range; and if the size of the range of the person detected by the person detection processing is smaller than a predetermined threshold, the face direction determination processing determines that the direction is the first direction when it detects that the direction of the face is within the second direction range, even if the distance to the person detected by the person detection processing is less than the predetermined distance. [Effects of the Invention]

[0020] According to the above aspect of the present invention, it is possible to more appropriately control the screen brightness using the ToF method. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a perspective view showing an example of the external configuration of an information processing apparatus according to a first embodiment. [Figure 2]FIG. 2 is a diagram showing an example of a person detection range of the information processing device according to the first embodiment. [Figure 3] FIG. 2 is an explanatory diagram of a method for determining a face direction according to the first embodiment. [Figure 4] FIG. 4 is a diagram showing an example of a screen brightness reduction process according to the first embodiment. [Figure 5] 5 is an explanatory diagram of the screen brightness reduction process when the opening angle θ is large according to the first embodiment. FIG. [Figure 6] FIG. 1 is a schematic block diagram showing an example of a hardware configuration of an information processing apparatus according to a first embodiment. [Figure 7] FIG. 1 is a schematic block diagram showing an example of the functional configuration of an information processing apparatus according to a first embodiment. [Figure 8] 6 is a flowchart showing an example of a screen brightness reduction process according to the first embodiment. [Figure 9] 6 is a flowchart showing an example of a screen brightness reduction process according to an opening angle θ according to the first embodiment. [Figure 10] FIG. 10 is an explanatory diagram of a screen brightness reduction process according to the second embodiment. [Figure 11] 10 is a flowchart showing an example of a face direction determination process according to the second embodiment. [Figure 12] FIG. 11 is an explanatory diagram of FoA according to the distance to a person according to the third embodiment. [Figure 13] FIG. 11 is a diagram showing an example of FoA switching at a short distance according to the third embodiment. [Figure 14] 11 is a flowchart showing an example of a face direction determination process according to the third embodiment. [Figure 15] 13 is a flowchart showing an example of a face direction determination process according to the fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. First Embodiment First, the first embodiment will be described. FIG. 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 (clamshell) 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 formed by the hinge mechanism 15. The opening angle (hinge angle) resulting from the rotation of the first housing 10 and the second housing 20 is shown as "θ".

[0023] 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."

[0024] 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 140°. 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.

[0025] 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 10a 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 is capable of measuring the distance in the direction facing the display screen of the display unit 110.

[0026] 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.

[0027] 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).

[0028] 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).

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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 the presence of a person (Presence=True) in front of the information processing device 1 in a standby state from a state in which no person is present (Presence=False), the information processing device 1 starts up the system and controls it to a normal operating state.

[0035] 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 orientation 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.

[0036] (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.

[0037] 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, 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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 can determine the orientation of the face based on the distance measurement values ​​of the upper, lower, left, and right parts of the face.

[0049] 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.

[0050] Furthermore, the information processing device 1 may detect the face angle in the up-down direction from the difference between the distance measurement value of the upper part of the face and the distance measurement value of the lower part of the face. Similarly, the information processing device 1 may detect the face angle in the left-right direction from the difference between the distance measurement value of the left part of the face and the distance measurement value of the right part of the face. Then, the information processing device 1 may determine the face direction (for example, whether it is facing forward or not) based on the face angle in the up-down direction and the face angle in the left-right direction.

[0051] 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 user is not paying attention to the information processing device 1), the information processing device 1 reduces the screen brightness of the display unit 110 to save power. The information processing device 1 may also reduce the screen brightness of the display unit 110 when a person who was in front of the information processing device 1 is no longer present. In this way, when there is no user present or when a user is present but not looking at the information processing device 1, the information processing device 1 can reduce unnecessary power consumption by reducing the screen brightness of the display unit 110. This process of reducing the screen brightness is hereinafter referred to as a "screen brightness reduction process."

[0052] Furthermore, in this screen brightness reduction process, when the face is directed forward again (when the user starts to look at the information processing device 1), the information processing device 1 restores the screen brightness to the original level before reduction.

[0053] Hereinafter, the original screen brightness before reduction will be referred to as "standard brightness," and the screen brightness reduced from the standard brightness 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.

[0054] 4 is a diagram showing an example of the screen brightness reduction process according to the present embodiment. For example, the information processing device 1 determines the orientation of the face of a person (user) present in front of the information processing device 1, and determines whether the face is facing forward.

[0055] 4A shows a state in which the face is facing forward with respect to the information processing device 1, and it can be determined that the user is paying attention to the screen of the display unit 110. Therefore, the information processing device 1 controls the screen brightness of the display unit 110 to standard brightness. On the other hand, FIG. 4B shows a state in which the face is not facing forward with respect to the information processing device 1 (for example, facing sideways), and it can be determined that the user is not paying attention to the screen of the display unit 110. Therefore, when the face changes from the forward-facing state shown in FIG. 4A to the sideways state shown in FIG. 4B, the information processing device 1 reduces the screen brightness of the display unit 110 from standard brightness to low brightness. Furthermore, when the face changes from the sideways state shown in FIG. 4B to the forward-facing state shown in FIG. 4A, the information processing device 1 restores the screen brightness of the display unit 110 from low brightness to standard brightness.

[0056] Hereinafter, in a person detection process that detects a person (person range) present within the detection range FoV using the ToF sensor 130, a detection result indicating that a person (person range) has been detected will be referred to as "Presence=True," and a detection result indicating that a person (person range) has not been detected will be referred to as "Presence=False." Furthermore, in a face direction determination process that determines the facial orientation of a person present within the detection range FoV using the ToF sensor 130, a determination result indicating that a person has been determined to be facing forward (paying attention to the information processing device 1) will be referred to as "Attention=True," and a determination result indicating that a person has been determined not to be facing forward (not paying attention to the information processing device 1) will be referred to as "Attention=False."

[0057] Here, the detection method of people and faces based on distance information using the ToF sensor 130 has limited detection resolution and a detection range (FoV) compared to the detection of people and faces using a camera. For example, because the detection range (FoV) is narrow, depending on the usage situation, part or all of the user's body may not be within the detection range (FoV). For example, when a user uses the device with a large opening angle θ, the ranging direction of the ToF sensor 130 faces upward, shifting the detection range (FoV) upward and making it difficult for the user's body to be within the detection range (FoV). For this reason, in the past, a countermeasure was sometimes taken to disable the screen brightness reduction process when the opening angle θ was large, so as to prevent the screen brightness from being reduced due to the inability to detect the user even though the user was present.

[0058] However, even when the opening angle θ is large, it may be possible to detect the user's body or face depending on the user's usage state (such as posture or positional relationship with the information processing device 1). Therefore, the information processing device 1 according to this embodiment enables the screen brightness reduction process depending on the conditions even when the opening angle θ is large, thereby achieving further power saving.

[0059] A specific description will be given below. The information processing device 1 enables the screen brightness reduction process when the opening angle θ is not large (for example, 0 to 140°). That is, when the opening angle θ is not large (for example, 0 to 140°), the information processing device 1 reduces the screen brightness both when no person (a range of people) is detected (Presence=False) and when the person is not facing forward (Attention=False).

[0060] On the other hand, when the opening angle θ is large (for example, 140 to 180°) and a person (a range of people) is not detected (Presence=False), the information processing device 1 disables the screen brightness reduction process, and when a person (a range of people) is detected (Presence=True), the information processing device 1 enables the screen brightness reduction process. That is, when the opening angle θ is large (for example, 140 to 180°), the information processing device 1 reduces the screen brightness only when a person is not facing forward (Attention=False), and when a person (a range of people) is not detected (Presence=False), the information processing device 1 disables the screen brightness reduction process (keeps the screen brightness at standard brightness).

[0061] FIG. 5 is an explanatory diagram of the screen brightness reduction process when the opening angle θ is large according to this embodiment. (A) in FIG. 5 shows a state in which a user is present but the detection range FoV is shifted upward due to the large opening angle θ, and the user's body is not included in the range. Since no person (range of person) is detected (Presence=False), the information processing device 1 disables the screen brightness reduction process and controls the screen brightness to standard brightness. This makes it possible to prevent the screen brightness from being erroneously reduced when the opening angle θ is large, even though the user is present.

[0062] 5B and 5C show an example in which the detection range FoV is shifted upward because the opening angle θ is large, as in FIG. 5A, but the detection range FoV is included depending on the user's usage state (posture, positional relationship with the information processing device 1, etc.) When a person (person range) is detected (Presence=True), the information processing device 1 enables the screen brightness reduction process.

[0063] In the example shown in Fig. 5(B), the user is not facing forward (Attention = False), so the screen brightness is set to low. On the other hand, in the example shown in Fig. 5(C), the user is facing forward (Attention = True), so the screen brightness is left at standard brightness. As a result, even when the opening angle θ is large, if an object (a range of a person) is detected (Presence = True) depending on the user's usage state (posture, positional relationship with the information processing device 1, etc.), the screen brightness reduction process can be enabled to achieve power saving.

[0064] [Hardware configuration of information processing device] Next, the configuration of the information processing device 1 will be described in detail. Fig. 6 is a schematic block diagram showing an example of the hardware configuration of an information processing device 1 according to this embodiment. In Fig. 6, components corresponding to those in Fig. 1 are assigned the same reference numerals. The information processing device 1 includes a display unit 110, an acceleration sensor 120, 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.

[0065] 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.

[0066] The acceleration sensor 120 includes at least two acceleration sensors. The acceleration sensors 120 are provided inside the first housing 10 and the second housing 20, respectively. The acceleration sensors 120 detect the orientations and changes in orientations of the first housing 10 and the second housing 20. For example, the acceleration sensor 120 detects the accelerations of the first housing 10 in three axial directions and the accelerations of the second housing 20 in three axial directions, and outputs detection signals indicating the detection results.

[0067] 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).

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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 a startup process that starts the system from a standby state and transitions it to a normal operating state, and a sleep process that transitions it from the normal operating state to a standby state. CPU 301 also executes a screen brightness reduction process that reduces the screen brightness of display unit 110 based on the determination result of the face orientation described above.

[0076] 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.

[0077] 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 reading and writing of data from the system memory 304, the storage unit 170, etc. by the CPU 301 and the GPU 302. 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 a detection signal output from the acceleration sensor 120 and a ranging signal output from the ToF sensor 130.

[0078] 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.

[0079] 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.

[0080] [Functional configuration of information processing device] Next, the functional configuration of the information processing device 1 that executes the above-mentioned screen brightness reduction process will be described. Fig. 7 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 detects the opening angle θ between the first housing 10 and the second housing, detects a person present in front of the information processing device 1, and determines the direction of their face, and a screen brightness control unit 310 that controls the screen brightness of the display unit 110 based on the detection results and determination results by the detection processing unit 210.

[0081] The detection processing unit 210 includes an angle detection unit 211, a person detection unit 212, a face range detection unit 213, a face direction determination unit 214, and a detection result output unit 215 as functional components that detect the above-mentioned opening angle θ, detect people, and determine the direction of their faces by the CPU 301 or the chipset 303 or the like executing a specific program.

[0082] The angle detection unit 211 detects the opening angle θ (relative angle) between the first housing 10 and the second housing 20 based on the detection signal output from the acceleration sensor 120. The angle detection unit 211 outputs the detection result of the opening angle θ to the detection result output unit 215.

[0083] The person detection unit 212 performs a person detection process to detect a person (a range of a person) present within the detection range FoV based on the distance measurement value of the ToF sensor 130. For example, since people move to some extent, unlike objects, when detecting a person, the person detection unit 212 may exclude completely stationary objects from the detection targets and may detect only objects that are moving (for example, slight movements).

[0084] Specifically, as described with reference to Fig. 3, the person 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 x 8 squares, based on the distance measurement signal output from the ToF sensor 130. Then, when 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 person detection unit 212 detects that range as a range of a person. The person detection unit 212 outputs the detection result of the person detection process to the detection result output unit 215.

[0085] When a person (person's area) is detected by the person detection unit 212, the face area detection unit 213 performs face area detection processing to detect the area of ​​the person's face. For example, the face area detection unit 213 detects the area of ​​the person's face based on the shape of the edges of the area of ​​the detected person. Specifically, the face area detection unit 213 detects the area of ​​the shoulders within the area of ​​the person, and detects an area of ​​3 (horizontal) × 4 (vertical) squares or 3 × 3 squares above the shoulder area as the area of ​​the face (see FIG. 3).

[0086] The face direction determination unit 214 performs face direction determination processing to determine the face direction based on the distance measurement values ​​within the face range detected by the face range detection unit 213. For example, the face direction determination unit 214 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. For example, as described with reference to FIG. 3, the face direction determination unit 214 detects the face angle in the vertical direction (up and down direction) and the face angle in the horizontal direction (left and right direction) based on the difference in distance measurement values ​​for the upper, lower, left, and right parts of the face, and determines the face direction (for example, whether the face is facing forward) based on the detected face angles. Note that the face direction determination unit 214 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.

[0087] The face direction determining unit 214 may determine whether or not the face is facing forward. The face direction determining unit 214 outputs the determination result of the face direction to the detection result output unit 215.

[0088] The detection result output unit 215 outputs information indicating the detection result of the opening angle θ by the angle detection unit 211 to the screen brightness control unit 310. For example, the detection result output unit 215 outputs angle information indicating the value of the opening angle θ detected by the angle detection unit 211. Note that the detection result output unit 215 may output angle information indicating either that the opening angle θ is not large (for example, 0 to 140°) or that the opening angle θ is large (for example, 140 to 180°) based on the value of the opening angle θ detected by the angle detection unit 211.

[0089] Furthermore, the detection result output unit 215 outputs information indicating the detection result by the person detection unit 212 to the screen brightness control unit 310. For example, based on the detection result by the person detection unit 212, if a person (a range of a person) is detected, the detection result output unit 215 outputs "Presence=True", and if a person (a range of a person) is not detected, the detection result output unit 215 outputs "Presence=False".

[0090] Furthermore, the detection result output unit 215 outputs information on the determination result by the face direction determination unit 214 to the screen brightness control unit 310. For example, based on the determination result by the face direction determination unit 214, the detection result output unit 215 outputs "Attention=True" if the face is facing forward, and outputs "Attention=False" if the face is not facing forward.

[0091] The screen brightness control unit 310 is a functional configuration realized by executing the BIOS and OS programs by the CPU 11. For example, the screen brightness control unit 310 includes a brightness reduction processing unit 311 and a timer 312 as functional configurations realized by executing the OS programs.

[0092] When the system is in a normal operating state, the brightness reduction processing unit 311 acquires angle information of the opening angle θ detected by the detection processing unit 210, information indicating the person detection result, and information indicating the face direction determination result, and controls the screen brightness of the display unit 110 based on the acquired information.

[0093] The brightness reduction processing unit 311 enables the screen brightness reduction processing when the opening angle θ is not large (for example, 0 to 140°). Specifically, when the brightness reduction processing unit 311 acquires "Presence=False", it controls the screen brightness to low. On the other hand, when the brightness reduction processing unit 311 acquires "Presence=True", it controls the screen brightness to standard brightness when "Attention=True" is acquired, and controls the screen brightness to low when "Attention=False" is acquired.

[0094] The timer 312 is a timer that measures the waiting time from when the brightness reduction processing unit 311 acquires "Attention=False" from the detection processing unit 210 while controlling the screen brightness to standard brightness until the brightness is controlled to low brightness. If the brightness reduction processing unit 311 acquires "Attention=True" before a predetermined waiting time has elapsed even after acquiring "Attention=False," the brightness reduction processing unit 311 does not control the screen brightness to low brightness and keeps it at standard brightness. If the brightness reduction processing unit 311 does not acquire "Attention=True" within the predetermined waiting time after acquiring "Attention=False," the brightness reduction processing unit 311 controls the screen brightness to low brightness. This prevents the screen brightness from being reduced 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.

[0095] [Screen brightness reduction processing operation] Next, the operation of the screen brightness reduction process executed by the screen brightness control unit 310 will be described with reference to Fig. 8. Fig. 8 is a flowchart showing an example of the screen brightness reduction 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.

[0096] (Step S101) The brightness reduction processing unit 311 determines whether or not "Attention=False" has been acquired from the detection processing unit 210. If the brightness reduction processing unit 311 determines that "Attention=False" has not been acquired (NO), it performs the process of step S101 again. On the other hand, if the brightness reduction processing unit 311 determines that "Attention=False" has been acquired (YES), it starts counting the waiting time using the timer 312 (step S103). Then, it proceeds to the process of step S105.

[0097] (Step S105) The brightness reduction processing unit 311 determines whether or not "Attention=True" has been acquired from the detection processing unit 210. When the brightness reduction processing unit 311 determines that "Attention=True" has not been acquired (NO), the brightness reduction processing unit 311 proceeds to the processing of step S107.

[0098] (Step S107) The brightness reduction processing unit 311 determines whether a predetermined waiting time (for example, 10 seconds) has elapsed (i.e., whether the timer has expired) based on the value of the timer 312. If the brightness reduction processing unit 311 determines that the predetermined waiting time (for example, 10 seconds) has not elapsed (i.e., the timer has not expired) (step S107: NO), the brightness reduction processing unit 311 returns to the processing of step S105. If the brightness reduction processing unit 311 determines that "Attention=True" has been acquired before the predetermined waiting time (for example, 10 seconds) has elapsed (step S105: YES), the brightness reduction processing unit 311 returns to the processing of step S101. At this time, the timer 312 is reset.

[0099] On the other hand, if it is determined in step S107 that the predetermined waiting time (for example, 10 seconds) has elapsed (step S107: YES), the brightness reduction processing unit 311 changes the screen brightness to low brightness (step S109), and then proceeds to the processing of step S111.

[0100] (Step S111) The brightness reduction processing unit 311 determines whether or not "Attention=True" has been acquired from the detection processing unit 210. If the brightness reduction processing unit 311 determines that "Attention=True" has not been acquired (NO), it performs the process of step S111 again. On the other hand, if the brightness reduction processing unit 311 determines that "Attention=True" has been acquired (YES), it returns the screen brightness to standard brightness (step S113).

[0101] Next, the screen brightness reduction process when the opening angle θ is large (for example, 140 to 180°) will be described. When the brightness reduction processing unit 311 acquires "Presence=False", it disables the screen brightness reduction process and fixes the screen brightness to standard brightness (does not reduce the screen brightness). On the other hand, when the brightness reduction processing unit 311 acquires "Presence=True", it enables the screen brightness reduction process, and when "Attention=True" it controls the screen brightness to standard brightness, and when "Attention=False" it controls the screen brightness to low brightness.

[0102] Here, with reference to FIG. 9, the operation of the screen brightness reduction process in which the information processing device 1 performs control to switch between enabling and disabling the screen brightness reduction process in accordance with the opening angle θ will be described. FIG. 9 is a flowchart showing an example of the screen brightness reduction process according to the opening angle θ according to this embodiment.

[0103] (Step S201) The brightness reduction processing unit 311 acquires angle information indicating the value of the opening angle θ from the detection processing unit 210 and determines the opening angle θ. If the brightness reduction processing unit 311 determines that the opening angle θ is greater than 0° and less than 140° (0°<θ<140°), the process proceeds to step S203. On the other hand, if the brightness reduction processing unit 311 determines that the opening angle θ is greater than 140° and less than 180° (140°≦θ≦180°), the process proceeds to step S205.

[0104] (Step S203) The luminance reduction processing unit 311 enables the screen luminance reduction processing. That is, when the opening angle θ is not large (for example, 0 to 140°), the luminance reduction processing unit 311 reduces the screen luminance from standard luminance to low luminance whether "Presence=False" or "Attention=False" is acquired.

[0105] (Step S205) The brightness reduction processing unit 311 determines whether it has acquired "Presence=True" or "Presence=False" as the detection result of a person (range of person) from the detection processing unit 210. If the brightness reduction processing unit 311 determines that it has acquired "Presence=True", it proceeds to the processing of step S207. On the other hand, if the brightness reduction processing unit 311 determines that it has acquired "Presence=False", it proceeds to the processing of step S209.

[0106] (Step S207) The brightness reduction processing unit 311 enables the screen brightness reduction processing.

[0107] (Step S209) The brightness reduction processing unit 311 disables the screen brightness reduction processing.

[0108] That is, when the opening angle θ is large (for example, 140 to 180°), the brightness reduction processing unit 311 does not perform brightness reduction processing when "Presence=False", and reduces the screen brightness from standard brightness to low brightness only when "Attention=False" is acquired.

[0109] [Summary of the first embodiment] As described above, the information processing device 1 according to this embodiment includes a ToF sensor 130 (an example of a first sensor) that divides a detection range FoV (an example of a predetermined detection range) into a plurality of measurement units (e.g., 8×8 squares) and measures the distance to an object for each measurement unit; an acceleration sensor 120 (an example of a second sensor) that detects the angle (e.g., opening angle θ) of the ToF sensor 130 relative to a preset reference direction; a system memory 304 (an example of a memory) that temporarily stores distance measurements (an example of distance information) indicating the distance for each measurement unit measured by the ToF sensor 130; and a processor (e.g., a CPU 301, a chipset 303, etc.) that executes processing (e.g., person detection processing, face direction determination processing, etc.) based on the distance measurements for each measurement unit. In the person detection processing, the information processing device 1 detects the range of a person present within the detection range FoV based on the distance measurements for each measurement unit. In the face direction determination processing, the information processing device 1 determines the direction of the person's face based on the distance measurements for each measurement unit within the range of a person detected within the detection range FoV. Furthermore, the information processing device 1 performs a screen brightness reduction process to reduce the screen brightness of the display unit 110.

[0110] For example, when the angle (e.g., opening angle θ) detected using the acceleration sensor 120 is less than a predetermined threshold (e.g., 0°<θ<140°), the information processing device 1 enables the screen brightness reduction process and reduces the screen brightness of the display unit 110 based on the determination results of the person detection process and the face direction determination process. On the other hand, when the angle (e.g., opening angle θ) detected using the acceleration sensor 120 is equal to or greater than a predetermined threshold (e.g., 140°≦θ≦180°), the information processing device 1 disables the screen brightness reduction process when a person's range is not detected within the detection range FoV by the person detection process, and enables the screen brightness reduction process when a person's range is detected within the detection range FoV by the person detection process, and reduces the screen brightness of the display unit 110 based on the determination results of the face direction determination process.

[0111] As a result, even when the angle (for example, opening angle θ) of the ToF sensor 130 is large, the information processing device 1 can reduce the screen brightness when the user is not facing forward, thereby saving power, while preventing the screen brightness from being unintentionally reduced depending on the user's usage state (posture, positional relationship with the information processing device 1, etc.). Thus, the information processing device 1 can more appropriately control the screen brightness using the ToF method.

[0112] The information processing device 1 also includes a first housing 10 provided with a ToF sensor 130, a second housing 20, and a hinge mechanism 15 (an example of a rotation mechanism) that rotatably couples the first housing 10 and the second housing 20 from a closed state (first state) in which an inner surface (an example of a first surface) of the first housing 10 and an inner surface (an example of a second surface) of the second housing 20 face each other and overlap, to an open state (second state) in which they are open and do not overlap. The acceleration sensor 120 is a sensor for detecting an opening angle θ (opening degree) corresponding to the rotation of the first housing 10 and the second housing 20 as the angle of the ToF sensor 130 with respect to a reference direction.

[0113] As a result, the information processing device 1 can reduce the screen brightness when the user is not facing forward, thereby saving power, while preventing the screen brightness from being unintentionally reduced depending on the user's usage state (such as posture or positional relationship with the information processing device 1), even when the opening angle θ between the first housing 10 and the second housing 20, in which the ToF sensor 130 is provided, is large. Therefore, the information processing device 1 can more appropriately control the screen brightness using the ToF method.

[0114] The acceleration sensor 120 may be a sensor for detecting the angle of the ToF sensor 130 with respect to the vertical direction as the angle of the ToF sensor 130 with respect to the reference direction.

[0115] As a result, the information processing device 1 detects the angle of the ToF sensor 130 relative to the vertical direction instead of the opening angle θ between the first housing 10 and the second housing 20 on which the ToF sensor 130 is provided, thereby preventing unintentional reduction in screen brightness due to the user's usage state (posture, positional relationship with the information processing device 1, etc.), and reducing the screen brightness when the user is not facing forward, thereby achieving power saving. Thus, the information processing device 1 can more appropriately control the screen brightness using the ToF method.

[0116] Furthermore, the control method in the information processing device 1 according to this embodiment is a control method in an information processing device 1 that includes a ToF sensor 130 (an example of a first sensor) that divides the detection range FoV (an example of a predetermined detection range) into multiple measurement units and measures the distance to an object for each measurement unit, an acceleration sensor 120 (an example of a second sensor) that detects the angle of the ToF sensor 130 relative to a preset reference direction (e.g., opening angle θ), a system memory 304 (an example of a memory) that temporarily stores distance measurements (an example of distance information) indicating the distance for each measurement unit measured by the ToF sensor 130, and a processor (e.g., a CPU 301, a chipset 303, etc.) that executes processing (e.g., person detection processing, face direction determination processing, etc.) based on the distance measurements for each measurement unit.

[0117] The control method in the information processing device 1 includes the steps of: performing a person detection process by the processor to detect the range of a person present within the detection range FoV based on distance measurement values ​​for each measurement unit; performing a face direction determination process to determine the direction of the person's face based on the distance measurement values ​​for each measurement unit within the range of the person detected within the detection range FoV; and performing a screen brightness reduction process to reduce the screen brightness of the display unit based on the detection results of the person detection process and the face direction determination process if the angle (e.g., opening angle θ) detected using the acceleration sensor 120 is less than a predetermined threshold (e.g., 0°<θ<140°).If the angle (e.g., opening angle θ) detected using the acceleration sensor 120 is equal to or greater than a predetermined threshold (e.g., 140°≦θ≦180°), the screen brightness reduction process is disabled when the range of a person is not detected within the detection range FoV by the person detection process; and the screen brightness reduction process is enabled when the range of a person is detected within the detection range FoV by the person detection process, and the screen brightness of the display unit 110 is reduced based on the determination result of the face direction determination process.

[0118] As a result, the control method in the information processing device 1 can reduce the screen brightness when the user is not facing forward, thereby saving power, while preventing the screen brightness from being unintentionally reduced depending on the user's usage state (posture, positional relationship with the information processing device 1, etc.) even when the angle of the ToF sensor 130 (for example, opening angle θ) is large. Therefore, the control method in the information processing device 1 can more appropriately control the screen brightness using the ToF method.

[0119] The threshold value for determining that the opening angle θ is large is not limited to 140°, but can be set arbitrarily as appropriate.

[0120] <Second embodiment> Next, a second embodiment will be described. In the first embodiment, the process of enabling the screen brightness reduction process (step S207 in FIG. 9) was described when a person (a range of people) was detected (Presence=True) when the opening angle θ was large (for example, 140 to 180°). However, since the detection range FoV shifts upward when the opening angle θ is large, even if a person (a range of people) is detected, the position of the face may fall outside the detection range FoV depending on the positional relationship between the person and the information processing device 1, and the direction of the face may not be determined correctly.

[0121] In this case, since a person (a range of people) has been detected, it is considered that the user is using the information processing device 1, but since the face direction cannot be determined correctly, there is a possibility that the screen brightness will be reduced as "Attention = False", which is not preferable. Therefore, in this embodiment, even if (a range of people) is detected (Presence = True) when the opening angle θ is large (for example, 140 to 180°), if the range of people detected is narrow or wide, there is a possibility that the face direction cannot be determined correctly, so the person is excluded from the target of face direction determination processing and fixed to "Attention = True".

[0122] FIG. 10 is an explanatory diagram of the screen brightness reduction process according to this embodiment. (A) of FIG. 10 shows an example in which the range of the detected person is narrow. For example, if the number of squares N in the range of the detected person is less than 10 (N<10), only a small part of the person's body is within the detection range FoV, and therefore the face direction may not be determined correctly. Therefore, if the number of squares N in the range of the detected person is less than 10 (N<10), the information processing device 1 excludes the person from the target of the face direction determination process and fixes it to "Attention=True." This allows the information processing device 1 to prevent the screen brightness from being unintentionally reduced despite the presence of a user.

[0123] (B) in FIG. 10 shows an example in which the range of the detected person is narrow. For example, if the number of squares N in the range of the detected person is greater than 44 (N>44), much of the person's torso is within the detection range FoV, and there is a possibility that the direction of the face cannot be determined correctly. Therefore, when the number of squares N in the range of the detected person is greater than 44 (N>44), the information processing device 1 excludes the person from the target of the face direction determination process and fixes it to "Attention=True." This enables the information processing device 1 to prevent the screen brightness from being unintentionally reduced despite the presence of a user.

[0124] In addition, if the number N of squares in the range of the detected person is 10 or more and 44 or less (10≦N≦44), the information processing device 1 performs face direction determination processing and outputs "Attention=True" or "Attention=False" based on the determination result.

[0125] 11 is a flowchart showing an example of the face direction determination process according to this embodiment, and the operation of the face direction determination process according to this embodiment will be described with reference to this FIG.

[0126] (Step S301) The detection processing unit 210 detects a person (range of person) present within the detection range FoV based on the distance measurement value of the ToF sensor 130, and determines whether "Presence=True" or "Presence=False." If the detection processing unit 210 determines that "Presence=False," the process proceeds to step S303. On the other hand, if the detection processing unit 210 determines that "Presence=True," the process proceeds to step S305.

[0127] (Step S303) Since "Presence=False", the detection processing unit 210 outputs "Attention=False".

[0128] (Step S305) The detection processing unit 210 determines the range (number of squares N) of the detected person. If the detection processing unit 210 determines that the range (number of squares N) of the detected person is 10 or more and 44 or less (10≦N≦44), the process proceeds to step S307. On the other hand, if the range (number of squares N) of the detected person is small (N<10) or greater than 44 (N>44), the detection processing unit 210 proceeds to step S311.

[0129] (Step S307) The detection processing unit 210 starts the face direction determination process based on the distance measurement value of the ToF sensor 130. Then, the process proceeds to step S309.

[0130] (Step S309) The detection processing unit 210 outputs "Attention=True" or "Attention=False" based on the determination result of the face direction determination process.

[0131] (Step S311) The detection processing unit 210 excludes the face from the target of the face direction determination processing, and then proceeds to the processing of step S313.

[0132] (Step S313) The detection processing unit 210 fixes the output of the determination result of the face direction determination process to "Attention=True."

[0133] [Summary of the second embodiment] As described above, the information processing device 1 according to this embodiment includes a ToF sensor 130 (an example of a first sensor) that divides the detection range FoV (an example of a predetermined detection range) into multiple measurement units and measures the distance to an object for each measurement unit, an acceleration sensor 120 (an example of a second sensor) that detects the angle of the ToF sensor 130 relative to a preset reference direction (e.g., opening angle θ), a system memory 304 (an example of a memory) that temporarily stores distance measurements (an example of distance information) indicating the distance for each measurement unit measured by the ToF sensor 130, and a processor (e.g., a CPU 301, a chipset 303, etc.) that executes processing (e.g., person detection processing, face direction determination processing, etc.) based on the distance measurements for each measurement unit.

[0134] In a person detection process, the information processing device 1 detects the range of a person present within the detection range FoV based on distance measurement values ​​for each measurement unit. Furthermore, in a face direction determination process, the information processing device 1 determines the direction of the person's face based on distance measurement values ​​for each measurement unit within the range of a person detected within the detection range FoV. The information processing device 1 then performs a screen brightness reduction process to reduce the screen brightness of the display unit 110 based on the determination results of the person detection process and the face direction determination process. If an angle (e.g., opening angle θ) detected using the acceleration sensor 120 is equal to or greater than a predetermined threshold (e.g., 140°), the information processing device 1 changes the control content of the face direction determination process based on the size of the range of a person detected within the detection range FoV by the person detection process.

[0135] This allows the information processing device 1 to more appropriately control the screen brightness using the ToF method by changing the control content of the face direction determination process depending on the positional relationship between the distance measurement direction of the ToF sensor 130 and the user.

[0136] For example, when an angle (e.g., opening angle θ) detected using the acceleration sensor 120 is equal to or greater than a predetermined threshold (e.g., 140°) and a person's range is detected within the detection range FoV by the person detection process, if the size of the detected person's range (number of squares N) is within a predetermined first range (e.g., 10≦N≦44), the information processing device 1 determines whether the face is facing a first direction (front) by face direction determination process, and if the size of the detected person's range (number of squares N) is outside the first range (e.g., N<10 or N>44), fixes the determination result of the face direction by the face direction determination process to the first direction (front) (Attention=True). Furthermore, if the determination result of the face direction by the face direction determination process is not the first direction (front), the information processing device 1 reduces the screen brightness of the display unit 110 by screen brightness reduction process.

[0137] This allows the information processing device 1 to reduce power consumption by reducing the screen brightness when the user's face is not facing forward while the face is being detected, while preventing the screen brightness from being unintentionally reduced when the face position is outside the detection range FoV due to the positional relationship with the user. Therefore, the information processing device 1 can more appropriately control the screen brightness using the ToF method.

[0138] Furthermore, the control method in the information processing device 1 according to this embodiment is a control method in an information processing device 1 that includes a ToF sensor 130 (an example of a first sensor) that divides the detection range FoV (an example of a predetermined detection range) into multiple measurement units and measures the distance to an object for each measurement unit, an acceleration sensor 120 (an example of a second sensor) that detects the angle of the ToF sensor 130 relative to a preset reference direction (e.g., opening angle θ), a system memory 304 (an example of a memory) that temporarily stores distance measurements (an example of distance information) indicating the distance for each measurement unit measured by the ToF sensor 130, and a processor (e.g., a CPU 301, a chipset 303, etc.) that executes processing (e.g., person detection processing, face direction determination processing, etc.) based on the distance measurements for each measurement unit.

[0139] The control method in the information processing device 1 includes the steps of: performing a person detection process by the processor to detect the range of a person present within the detection range FoV based on the distance measurement value for each measurement unit; performing a face direction determination process to determine the direction of the person's face based on the distance measurement value for each measurement unit within the range of the person detected within the detection range FoV; performing a screen brightness reduction process to reduce the screen brightness of the display unit 110 based on the detection results of the person detection process and the face direction determination process; and changing the control content of the face direction determination process based on the size of the range of the person detected within the detection range FoV by the person detection process when the angle (e.g., opening angle θ) detected using the acceleration sensor 120 is equal to or greater than a predetermined threshold value (e.g., 140°).

[0140] As a result, the control method in the information processing device 1 can more appropriately control the screen brightness using the ToF method by changing the control content of the face direction determination process depending on the positional relationship between the distance measurement direction of the ToF sensor 130 and the user.

[0141] For example, the control method in the information processing device 1 determines whether the face direction is in a first direction by face direction determination processing when the size of the range (number of squares N) of the person detected by the person detection processing is within a predetermined first range (for example, 10≦N≦44). Also, the control method in the information processing device 1 fixes the detection result of the face direction by the face direction determination processing to the first direction (front) (Attention=True) when the size of the range (number of squares N) of the detected person is outside the first range (for example, N<10 or N>44), and reduces the screen brightness of the display unit 110 by screen brightness reduction processing when the detection result of the face direction by the face direction determination processing is not the first direction (front).

[0142] As a result, the control method in the information processing device 1 can reduce power consumption by reducing the screen brightness when the user's face is not facing forward while the face is detected, while preventing the screen brightness from being unintentionally reduced when the face position is outside the detection range FoV due to the positional relationship with the user. Therefore, the control method in the information processing device 1 can more appropriately control the screen brightness using the ToF method.

[0143] The information processing device 1 may perform a process of changing the control content of the face direction determination process based on the size of the range of a person detected within the detection range FoV by the person detection process, regardless of whether the angle (e.g., opening angle θ) detected using the acceleration sensor 120 is equal to or greater than a predetermined threshold (e.g., 140°). For example, the information processing device 1 may determine, by the face direction determination process, whether the face is oriented in a first direction that faces forward relative to the information processing device 1 when the size of the range (number of squares N) of the person detected by the person detection process is within a predetermined first range (e.g., 10≦N≦44), without detecting the angle (e.g., opening angle θ) using the acceleration sensor 120, and may fix the determination result of the face direction by the face direction determination process to the first direction (forward) when the size of the range (number of squares N) of the detected person is outside the first range (e.g., N<10 or N>44) (Attention=True).

[0144] Although the threshold (first range) of the range (number of squares N) of detected people is set to 10 or more and 44 or less (10≦N≦44), this threshold can be set arbitrarily.

[0145] <Third embodiment> Next, a third embodiment will be described. When determining whether the face direction is forward based on the detected face angle, the face direction determination unit 214 changes the range of face angles (Field of Attention: FoA) at which the face direction is determined to be forward depending on the distance to the person.

[0146] 12 is an explanatory diagram of FoA according to the distance to a person according to this embodiment. When the distance to a person is far, the information processing device 1 may be used while being viewed from a position further from the center (for example, a position further to the left or right) than when the distance to a person is close. Therefore, the FoA for determining that the face is facing forward is set larger when the distance to a person is far than when the distance to a person is close. In other words, when determining whether the face is facing forward based on the detected face angle, the face direction determination unit 214 uses a small FoA when the distance to a person is close and a large FoA when the distance to a person is far.

[0147] For example, when the distance to the person is less than a predetermined distance (e.g., 700 mm), the face direction determination unit 214 uses a small FoA to determine whether the face is facing forward. On the other hand, when the distance to the person is equal to or greater than a predetermined distance (e.g., 700 mm), the face direction determination unit 214 uses a large FoA to determine whether the face is facing forward. Note that this predetermined distance is not limited to 700 mm and can be set to any distance.

[0148] In addition, the small and large FoAs can be set within any angle range. For example, if the front direction is set to 0°, the small FoA can be set to 0±30° and the large FoA can be set to 0±60°.

[0149] Here, in the second embodiment, even when the range of a detected person (the number of squares N) is 10 or more and 44 or less (10≦N≦44) and face direction determination processing is performed, if the user is close and assumes an inappropriate posture (for example, a posture in which the body is leaning diagonally), the face angle may fall outside the range with a small FoA, and the screen brightness may be unintentionally reduced. Therefore, in this embodiment, the face direction determination unit 214 switches between a small FoA and a large FoA, taking into consideration not only the distance to the person but also the range of the person (the number of squares N).

[0150] 13 is a diagram showing an example of FoA switching at close range according to this embodiment. Compared to when the user is in an appropriate posture as shown in FIG. 13A, when the user is in an inappropriate posture as shown in FIG. 13B, the range of the detected person (the number of squares N) is smaller. Therefore, when the distance to the person is less than a predetermined distance (e.g., 700 mm) but the range of the person (the number of squares N) is less than 25, the face direction determination unit 214 uses a large FoA to determine whether the face is facing forward. This prevents the screen brightness from being unintentionally reduced when the user is using the information processing device 1 in an inappropriate posture and the face is erroneously detected as not facing forward.

[0151] Furthermore, if the distance to the person is less than a predetermined distance (for example, 700 mm) and the range of the person (number of squares N) is 25 or more, the face direction determination unit 214 uses a small FoA to determine whether the face is facing forward.

[0152] The threshold value of the range of a person (the number of squares N) when determining whether or not the user is in an inappropriate posture is not limited to 25, but can be set arbitrarily.

[0153] 14 is a flowchart showing an example of the face direction determination process according to this embodiment, and the operation of the face direction determination process according to this embodiment will be described with reference to this FIG.

[0154] (Step S401) The detection processing unit 210 detects a person (range of person) present within the detection range FoV based on the distance measurement value of the ToF sensor 130, and determines whether "Presence=True" or "Presence=False." If the detection processing unit 210 determines that "Presence=False," it proceeds to processing of step S403. On the other hand, if the detection processing unit 210 determines that "Presence=True," it proceeds to processing of step S405.

[0155] (Step S403) Since "Presence=False", the detection processing unit 210 outputs "Attention=False".

[0156] (Step S405) The detection processing unit 210 determines the distance D to the person based on the distance measurement value of the ToF sensor 130. For example, the detection processing unit 210 compares the average distance measurement value in the range of the detected person with a predetermined distance (for example, 700 mm) to make a determination. If the detection processing unit 210 determines that the distance D to the person is 700 mm or more (D≧700 mm), the process proceeds to step S411. On the other hand, if the detection processing unit 210 determines that the distance D to the person is less than 700 mm (D<700), the process proceeds to step S411.

[0157] (Step S407) If the distance to the person is far, the detection processing unit 210 starts the face direction determination process using a large FoA, and then proceeds to the process of step S409.

[0158] (Step S409) The detection processing unit 210 outputs "Attention=True" or "Attention=False" based on the determination result of the face direction determination process.

[0159] (Step S411) In order to determine whether the user's posture is appropriate or inappropriate, the detection processing unit 210 determines whether the range of the detected person (number of squares N) is 25 or more. If the detection processing unit 210 determines that the range of the detected person (number of squares N) is 25 or more, it determines that the user's posture is appropriate, and proceeds to the processing of step S413. On the other hand, if the detection processing unit 210 determines that the range of the detected person (number of squares N) is less than 25, it determines that the user's posture is inappropriate, and proceeds to the processing of step S417.

[0160] (Step S413) Because the user's posture is appropriate at close range, the detection processing unit 210 starts the face direction determination process using a small FoA, and then proceeds to the process of step S415.

[0161] (Step S415) The detection processing unit 210 outputs "Attention=True" or "Attention=False" based on the determination result of the face direction determination process.

[0162] (Step S417) If the user's posture is inappropriate even if the distance is short, the detection processing unit 210 starts the face direction determination process using a large FoA, and then proceeds to the process of step S419.

[0163] (Step S419) The detection processing unit 210 outputs "Attention=True" or "Attention=False" based on the determination result of the face direction determination process.

[0164] [Summary of the third embodiment] As described above, the information processing device 1 according to this embodiment includes a ToF sensor 130 (an example of a first sensor) that divides a detection range FoV (an example of a predetermined detection range) into multiple measurement units and measures the distance to an object for each measurement unit; an acceleration sensor 120 (an example of a second sensor) that detects the angle (e.g., opening angle θ) of the ToF sensor 130 relative to a preset reference direction; a system memory 304 (an example of a memory) that temporarily stores distance measurements (an example of distance information) indicating the distance for each measurement unit measured by the ToF sensor 130; and a processor (e.g., a CPU 301, a chipset 303, etc.) that executes processing (e.g., person detection processing, face direction determination processing, etc.) based on the distance measurements for each measurement unit. In the person detection processing, the information processing device 1 detects the range of a person present within the detection range FoV based on the distance measurements for each measurement unit. In the face direction determination processing, the information processing device 1 determines the direction of the person's face based on the distance measurements for each measurement unit within the range of a person detected within the detection range FoV. Furthermore, the information processing device 1 performs a screen brightness reduction process for reducing the screen brightness of the display unit 110 based on the detection results of the person detection process and the face direction determination process.

[0165] Furthermore, based on distance information for each measurement unit of the range of a person detected by person detection processing, if the distance to the person is less than a predetermined distance (e.g., 700 mm), the information processing device 1 determines that the face direction (face angle) is the first direction (front) (Attention=True) when the face direction determination processing detects that the face direction (face angle) is within a first direction range (e.g., small FoA) including the first direction (front). On the other hand, based on distance information for each measurement unit of the range of a person detected by person detection processing, if the distance to the person is equal to or greater than a predetermined distance (e.g., 700 mm), the information processing device 1 determines that the face direction (face angle) is the first direction (front) (Attention=True). Then, when the angle (e.g., opening angle θ) detected using the acceleration sensor 120 is equal to or greater than a predetermined threshold (e.g., 140°) and the size of the range (number of squares N) of the person detected by the person detection process is within a first range (e.g., 10≦N≦44), if the size of the range of the person is smaller than a predetermined threshold (e.g., 25) within the first range, the information processing device 1 determines that the face direction is the first direction (front) (Attention=True) when the face direction determination process detects that the face direction is within a second direction range (e.g., large FoA), even if the distance to the person detected by the person detection process is less than the predetermined distance.

[0166] This allows the information processing device 1 to prevent the screen brightness from being unintentionally reduced due to a nearby user taking an inappropriate posture (for example, a posture in which the body is leaning diagonally). Therefore, the information processing device 1 can more appropriately control the screen brightness using the ToF method.

[0167] Furthermore, the control method in the information processing device 1 according to this embodiment is a control method in an information processing device 1 that includes a ToF sensor 130 (an example of a first sensor) that divides the detection range FoV (an example of a predetermined detection range) into multiple measurement units and measures the distance to an object for each measurement unit, an acceleration sensor 120 (an example of a second sensor) that detects the angle of the ToF sensor 130 relative to a preset reference direction (e.g., opening angle θ), a system memory 304 (an example of a memory) that temporarily stores distance measurements (an example of distance information) indicating the distance for each measurement unit measured by the ToF sensor 130, and a processor (e.g., a CPU 301, a chipset 303, etc.) that executes processing (e.g., person detection processing, face direction determination processing, etc.) based on the distance measurements for each measurement unit.

[0168] The control method in the information processing device 1 includes the steps of: performing a person detection process by the processor to detect the range of a person present within the detection range FoV based on distance measurement values ​​for each measurement unit; performing a face direction determination process to determine the direction of the person's face based on distance measurement values ​​for each measurement unit within the range of a person detected within the detection range FoV; and performing a screen brightness reduction process to reduce the screen brightness of the display unit 110 based on the detection results of the person detection process and the face direction determination process, and determining the direction of the person's face based on distance information for each measurement unit within the range of a person detected by the person detection process. If the distance to the object is less than a predetermined distance (e.g., 700 mm), the face direction determination process determines that the face direction (face angle) is within a first direction range (e.g., a small FoA) that includes the first direction (front), and determines that the face is in the first direction (front) (Attention=True).If the distance to the person is greater than or equal to a predetermined distance (e.g., 700 mm), the face direction determination process determines that the face direction (face angle) is within a second direction range (e.g., a large FoA) that is wider than the first direction range, and determines that the face is in the first direction (front) (Attention=True). Furthermore, the control method in the information processing device 1 is such that, when the angle (e.g., opening angle θ) detected using the acceleration sensor 120 is equal to or greater than a predetermined threshold (e.g., 140°) and the size of the range (number of squares N) of the person detected by the person detection process is within a first range (e.g., 10≦N≦44), if the size of the range of the person is smaller than a predetermined threshold (e.g., 25) within the first range, even if the distance to the person detected by the person detection process is less than a predetermined distance (e.g., 700 mm), the face direction determination process determines that the face direction is within a second direction range (e.g., large FoA) and determines that the face is facing in the first direction (front) (Attention=True).

[0169] As a result, the control method in the information processing device 1 can prevent the screen brightness from being unintentionally reduced due to an inappropriate posture (for example, a posture in which the body is leaning diagonally) of a user who is nearby. Therefore, the control method in the information processing device 1 can more appropriately control the screen brightness using the ToF method.

[0170] The information processing device 1 may perform the process of changing the control content of the face direction determination process based on the size of the range of the person detected within the detection range FoV by the person detection process, regardless of whether the angle (e.g., opening angle θ) detected using the acceleration sensor 120 is equal to or greater than a predetermined threshold (e.g., 140°). For example, without detecting the angle (e.g., opening angle θ) using the acceleration sensor 120, when the size of the range (number of squares N) of the person detected by the person detection process is within a first range (e.g., 10≦N≦44), and the size of the range of the person is smaller than a predetermined threshold (e.g., 25) within the first range, the information processing device 1 may determine that the face direction is in the first direction (front) (Attention=True) when the face direction determination process detects that the direction of the face is within a second direction range (e.g., large FoA) even if the distance to the person detected by the person detection process is less than a predetermined distance (e.g., 700 mm).

[0171] <Fourth embodiment> Next, a fourth embodiment will be described. In this embodiment, a face direction determination process that combines the face direction determination process according to the second embodiment (see FIG. 11) and the face direction determination process according to the third embodiment (see FIG. 14) will be described.

[0172] Fig. 15 is a flowchart showing an example of face direction determination processing according to this embodiment. The operation of the face direction determination processing according to this embodiment will be described with reference to Fig. 15. Note that in Fig. 15, processes corresponding to those shown in Fig. 11 or 14 are denoted by the same reference numerals.

[0173] (Step S301) The detection processing unit 210 detects a person (range of person) present within the detection range FoV based on the distance measurement value of the ToF sensor 130, and determines whether "Presence=True" or "Presence=False." If the detection processing unit 210 determines that "Presence=False," the process proceeds to step S303. On the other hand, if the detection processing unit 210 determines that "Presence=True," the process proceeds to step S305.

[0174] (Step S303) Since "Presence=False", the detection processing unit 210 outputs "Attention=False".

[0175] (Step S305) The detection processing unit 210 determines the range (number of squares N) of the detected person. If the range (number of squares N) of the detected person is small (N<10) or greater than 44 (N>44), the detection processing unit 210 proceeds to processing of step S311. On the other hand, if the detection processing unit 210 determines that the range (number of squares N) of the detected person is between 10 and 44 (10≦N≦44), the detection processing unit 210 proceeds to processing of step S405.

[0176] (Step S311) The detection processing unit 210 excludes the face from the target of the face direction determination processing, and then proceeds to the processing of step S313.

[0177] (Step S313) The detection processing unit 210 fixes the output of the determination result of the face direction determination process to "Attention=True."

[0178] (Step S405) The detection processing unit 210 determines the distance D to the person based on the distance measurement value of the ToF sensor 130. For example, the detection processing unit 210 compares the average distance measurement value in the range of the detected person with a predetermined distance (for example, 700 mm) to make a determination. If the detection processing unit 210 determines that the distance D to the person is 700 mm or more (D≧700 mm), the process proceeds to step S411. On the other hand, if the detection processing unit 210 determines that the distance D to the person is less than 700 mm (D<700), the process proceeds to step S411.

[0179] (Step S407) If the distance to the person is far, the detection processing unit 210 starts the face direction determination process using a large FoA, and then proceeds to the process of step S409.

[0180] (Step S409) The detection processing unit 210 outputs "Attention=True" or "Attention=False" based on the determination result of the face direction determination process.

[0181] (Step S411) In order to determine whether the user's posture is appropriate or inappropriate, the detection processing unit 210 determines whether the range of the detected person (number of squares N) is 25 or more. If the detection processing unit 210 determines that the range of the detected person (number of squares N) is 25 or more, it determines that the user's posture is appropriate, and proceeds to the processing of step S413. On the other hand, if the detection processing unit 210 determines that the range of the detected person (number of squares N) is less than 25, it determines that the user's posture is inappropriate, and proceeds to the processing of step S417.

[0182] (Step S413) Because the user's posture is appropriate at close range, the detection processing unit 210 starts the face direction determination process using a small FoA, and then proceeds to the process of step S415.

[0183] (Step S415) The detection processing unit 210 outputs "Attention=True" or "Attention=False" based on the determination result of the face direction determination process.

[0184] (Step S417) If the user's posture is inappropriate even if the distance is short, the detection processing unit 210 starts the face direction determination process using a large FoA, and then proceeds to the process of step S419.

[0185] (Step S419) The detection processing unit 210 outputs "Attention=True" or "Attention=False" based on the determination result of the face direction determination process.

[0186] 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.

[0187] 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.

[0188] 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.

[0189] In addition, in the above embodiment, an example was described in which the detection range FoV was divided into measurement units of 8x8 squares and distance measurement was performed for each square (measurement unit) using the TOF sensor 130, but the number of divisions of the detection range FoV may be other than 8x8 squares.

[0190] 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.

[0191] 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.

[0192] 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.

[0193] 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.

[0194] 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.

[0195] 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]

[0196] 1 Information processing device First housing, 20 Second housing, 15 Hinge mechanism, 110 Display unit, 120 Acceleration sensor, 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 Angle detection unit, 212 Person detection unit, 213 Face range detection unit, 214 Face direction determination unit, 215 Detection result output unit, 300 Main processing unit, 301 CPU, 302 GPU, 303 Chipset, 304 System memory, 310 Screen brightness control unit, 311 Brightness reduction processing unit, 312 Timer, 400 Power supply unit

Claims

1. a first sensor for dividing a predetermined detection range into a plurality of measurement units and measuring a distance to an object for each of the measurement units; a second sensor for detecting an angle of the first sensor relative to a preset reference direction; a memory that temporarily stores distance information indicating the distance for each measurement unit measured by the first sensor; a processor that executes processing based on the distance information for each measurement unit; Equipped with The processor: a person detection process for detecting a range of a person present within the detection range based on the distance information for each measurement unit; a face direction determination process for determining a direction of the face of the person based on distance information for each measurement unit within the range of the person detected within the detection range; a screen brightness reduction process for reducing the screen brightness of a display unit based on the detection results of the person detection process and the face direction determination process; and When the angle detected by the second sensor is equal to or greater than a predetermined threshold, the control content of the face direction determination process is changed based on the size of the range of the person detected within the detection range by the person detection process. Information processing device.

2. The processor: when the angle detected using the second sensor is less than a predetermined threshold, the screen brightness reduction process is enabled, and when a range of a person is not detected within the detection range by the person detection process, the screen brightness of the display unit is reduced, and when a range of a person is detected within the detection range by the person detection process, the screen brightness of the display unit is reduced based on the detection result of the face direction determination process; When the angle detected using the second sensor is equal to or greater than a predetermined threshold, if the range of a person is not detected within the detection range by the person detection process, the screen brightness reduction process is disabled, and if the range of a person is detected within the detection range by the person detection process, the screen brightness reduction process is enabled and the screen brightness of the display unit is reduced based on the detection result of the face direction determination process. The information processing device according to claim 1 .

3. The processor: when the angle detected using the second sensor is equal to or greater than a predetermined threshold and a range of a person is detected within the detection range by the person detection process, if the size of the range of the detected person is within a predetermined first range, determine by the face direction determination process whether or not the orientation of the face is a first direction that is a front direction with respect to the information processing device, and if the size of the range of the detected person is outside the first range, fix the detection result of the orientation of the face by the face direction determination process to the first direction; When the face direction detection result obtained by the face direction determination process is not the first direction, the screen brightness of the display unit is reduced by the screen brightness reduction process. The information processing device according to claim 2 .

4. The processor: based on distance information for each measurement unit of the range of the person detected by the person detection processing, when the distance to the person is less than a predetermined distance, the face direction determination processing determines that the direction of the face is the first direction when it is detected that the direction of the face is within a first direction range that includes the first direction, and when the distance to the person is equal to or greater than the predetermined distance, the face direction determination processing determines that the direction of the face is the first direction when it is detected that the direction of the face is within a second direction range that is wider than the first direction range; When the angle detected using the second sensor is equal to or greater than a predetermined threshold and the size of the range of the person detected by the person detection process is within the first range, if the size of the range of the person is smaller than a predetermined threshold within the first range, even if the distance to the person detected by the person detection process is less than a predetermined distance, the face direction is determined to be the first direction when the face direction determination process detects that the direction of the face is within the second direction range. The information processing device according to claim 3 .

5. a first housing in which the first sensor is provided; A second housing; a rotation mechanism that rotatably couples the first housing and the second housing from a closed first state in which a first surface of the first housing and a second surface of the second housing face each other and overlap, to an open second state in which the first surface and the second surface do not overlap; Equipped with the second sensor is a sensor for detecting an opening degree corresponding to a rotation of the first housing and the second housing as an angle of the first sensor with respect to the reference direction. The information processing device according to claim 1 .

6. the second sensor is a sensor for detecting an angle of the first sensor with respect to a vertical direction as an angle of the first sensor with respect to the reference direction; The information processing device according to claim 1 .

7. a first sensor for dividing a predetermined detection range into a plurality of measurement units and measuring a distance to an object for each of the measurement units; a second sensor for detecting an angle of the first sensor relative to a preset reference direction; a memory that temporarily stores distance information indicating the distance for each measurement unit measured by the first sensor; a processor that executes processing based on the distance information for each measurement unit; Equipped with The processor: a person detection process for detecting a range of a person present within the detection range based on the distance information for each measurement unit; a face direction determination process for determining a direction of the face of the person based on distance information for each measurement unit within the range of the person detected within the detection range; a screen brightness reduction process for reducing the screen brightness of a display unit based on the detection results of the person detection process and the face direction determination process; and when the angle detected using the second sensor is less than a predetermined threshold, the screen brightness reduction process is enabled, and when a range of a person is not detected within the detection range by the person detection process, the screen brightness of the display unit is reduced, and when a range of a person is detected within the detection range by the person detection process, the screen brightness of the display unit is reduced based on the detection result of the face direction determination process; When the angle detected using the second sensor is equal to or greater than a predetermined threshold, if the range of a person is not detected within the detection range by the person detection process, the screen brightness reduction process is disabled, and if the range of a person is detected within the detection range by the person detection process, the screen brightness reduction process is performed to reduce the screen brightness of the display unit based on the detection result of the face direction determination process. Information processing device.

8. a first sensor for dividing a predetermined detection range into a plurality of measurement units and measuring a distance to an object for each of the measurement units; a memory that temporarily stores distance information indicating the distance for each measurement unit measured by the first sensor; a processor that executes processing based on the distance information for each measurement unit; Equipped with The processor: a person detection process for detecting a range of a person present within the detection range based on the distance information for each measurement unit; a face direction determination process for determining a direction of the face of the person based on distance information for each measurement unit within the range of the person detected within the detection range; a screen brightness reduction process for reducing the screen brightness of a display unit based on the detection results of the person detection process and the face direction determination process; and when the size of the range of the person detected by the person detection processing is within a predetermined first range, the face direction determination processing determines whether or not the orientation of the face is a first direction that faces forward relative to the information processing device itself, and when the size of the range of the detected person is outside the first range, the detection result of the orientation of the face by the face direction determination processing is fixed to the first direction; When the face direction detection result obtained by the face direction determination process is not the first direction, the screen brightness of the display unit is reduced by the screen brightness reduction process. Information processing device.

9. a first sensor for dividing a predetermined detection range into a plurality of measurement units and measuring a distance to an object for each of the measurement units; a memory that temporarily stores distance information indicating the distance for each measurement unit measured by the first sensor; a processor that executes processing based on the distance information for each measurement unit; Equipped with The processor: a person detection process for detecting a range of a person present within the detection range based on the distance information for each measurement unit; a face direction determination process for determining a direction of the face of the person based on distance information for each measurement unit within the range of the person detected within the detection range; a screen brightness reduction process for reducing the screen brightness of a display unit based on the detection results of the person detection process and the face direction determination process; and based on distance information for each measurement unit of the range of the person detected by the person detection processing, when the distance to the person is less than a predetermined distance, the face direction determination processing determines that the direction of the face is the first direction when it is detected by the face direction determination processing that the direction of the face is within a first direction range including a first direction in which the face is directly in front of the self-recording information processing device, and when the distance to the person is equal to or greater than the predetermined distance, the face direction determination processing determines that the direction of the face is the first direction when it is detected by the face direction determination processing that the direction of the face is within a second direction range wider than the first direction range, When the size of the range of the person detected by the person detection process is smaller than a predetermined threshold, even if the distance to the person detected by the person detection process is less than a predetermined distance, if the face direction determination process detects that the direction of the face is within the second direction range, it is determined that the direction is the first direction. Information processing device.

10. A control method for an information processing device including: a first sensor for dividing a predetermined detection range into a plurality of measurement units and measuring a distance to an object for each of the measurement units; a second sensor for detecting an angle of the first sensor with respect to a preset reference direction; a memory for temporarily storing distance information indicating the distance for each of the measurement units measured by the first sensor; and a processor for executing processing based on the distance information for each of the measurement units, the processor: a step of performing a person detection process to detect a range of people present within the detection range based on the distance information for each measurement unit; performing a face direction determination process for determining a direction of a person's face based on distance information for each measurement unit within the range of the person detected within the detection range; a step of performing a screen brightness reduction process to reduce the screen brightness of a display unit based on the detection results of the person detection process and the face direction determination process; a step of changing control content of the face direction determination process based on the size of the range of the person detected within the detection range by the person detection process when the angle detected using the second sensor is equal to or greater than a predetermined threshold; A control method comprising:

11. A control method for an information processing device including: a first sensor for dividing a predetermined detection range into a plurality of measurement units and measuring a distance to an object for each of the measurement units; a second sensor for detecting an angle of the first sensor with respect to a preset reference direction; a memory for temporarily storing distance information indicating the distance for each of the measurement units measured by the first sensor; and a processor for executing processing based on the distance information for each of the measurement units, the processor: a step of performing a person detection process to detect a range of people present within the detection range based on the distance information for each measurement unit; performing a face direction determination process for determining a direction of a person's face based on distance information for each measurement unit within the range of the person detected within the detection range; a step of performing a screen brightness reduction process to reduce the screen brightness of a display unit based on the detection results of the person detection process and the face direction determination process; Including, In the screen brightness reduction process when the angle detected using the second sensor is less than a predetermined threshold, the screen brightness reduction process is enabled, and when a range of a person is not detected within the detection range by the person detection process, the screen brightness of the display unit is reduced, and when a range of a person is detected within the detection range by the person detection process, the screen brightness of the display unit is reduced based on the detection result of the face direction determination process; When the angle detected using the second sensor is equal to or greater than a predetermined threshold, if the range of a person is not detected within the detection range by the person detection process, the screen brightness reduction process is disabled, and if the range of a person is detected within the detection range by the person detection process, the screen brightness reduction process is performed to reduce the screen brightness of the display unit based on the detection result of the face direction determination process. Control method.

12. A control method for an information processing device including: a first sensor for dividing a predetermined detection range into a plurality of measurement units and measuring a distance to an object for each of the measurement units; a memory for temporarily storing distance information indicating the distance for each of the measurement units measured by the first sensor; and a processor for executing processing based on the distance information for each of the measurement units, the processor: a step of performing a person detection process to detect a range of people present within the detection range based on the distance information for each measurement unit; performing a face direction determination process for determining a direction of a person's face based on distance information for each measurement unit within the range of the person detected within the detection range; a step of performing a screen brightness reduction process to reduce the screen brightness of a display unit based on the detection results of the person detection process and the face direction determination process; Including, when the size of the range of the person detected by the person detection processing is within a predetermined first range, the face direction determination processing determines whether or not the orientation of the face is a first direction that faces forward with respect to the information processing device, and when the size of the range of the detected person is outside the first range, the detection result of the orientation of the face by the face direction determination processing is fixed to the first direction; When the face direction detection result obtained by the face direction determination process is not the first direction, the screen brightness of the display unit is reduced by the screen brightness reduction process. Control method.

13. A control method for an information processing device including: a first sensor for dividing a predetermined detection range into a plurality of measurement units and measuring a distance to an object for each of the measurement units; a memory for temporarily storing distance information indicating the distance for each of the measurement units measured by the first sensor; and a processor for executing processing based on the distance information for each of the measurement units, the processor: a step of performing a person detection process to detect a range of people present within the detection range based on the distance information for each measurement unit; performing a face direction determination process for determining a direction of a person's face based on distance information for each measurement unit within the range of the person detected within the detection range; a step of performing a screen brightness reduction process to reduce the screen brightness of a display unit based on the detection results of the person detection process and the face direction determination process; Including, based on distance information for each measurement unit of the range of the person detected by the person detection processing, when the distance to the person is less than a predetermined distance, the face direction determination processing determines that the direction of the face is the first direction when it is detected by the face direction determination processing that the direction of the face is within a first direction range including a first direction in which the face is directly in front of the information processing device, and when the distance to the person is equal to or greater than the predetermined distance, the face direction determination processing determines that the direction of the face is the first direction when it is detected by the face direction determination processing that the direction of the face is within a second direction range wider than the first direction range, When the size of the range of the person detected by the person detection process is smaller than a predetermined threshold, even if the distance to the person detected by the person detection process is less than a predetermined distance, if the face direction determination process detects that the direction of the face is within the second direction range, it is determined that the direction is the first direction. Control method.

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