Information processing device and control method

Abstract

To perform more appropriate screen brightness control using the ToF (Time of Flight) method. [Solution] The information processing device comprises a first sensor for dividing a predetermined detection range into multiple measurement units and measuring the distance to an object for each measurement unit, a second sensor for detecting the angle of the first sensor with respect to a preset reference direction, and a processor that performs processing based on the distance information for each measurement unit. The device performs a person detection process to detect the range of a person within the detection range based on the distance information for each measurement unit, a face direction determination process to determine the orientation of the person's face based on the distance information for each measurement unit within the range of the person detected within the detection range, and a screen brightness reduction process to reduce the screen brightness of the display unit based on the detection results from the person detection process and the face direction determination process. If the angle detected using the second sensor is greater than or equal to 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.

Description

Technical Field

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

Background Art

[0002] In recent years, with the development of computer vision and the like, the detection accuracy when detecting a face from a captured image captured by a camera has increased, and detection of a person by face detection has also been performed. In the detection of a person by face detection, not only can a person be simply detected, but also the orientation of the face can be detected. Therefore, it is also possible to perform control according to the orientation of the face (whether facing forward, sideways, etc.). For example, when the face is turned sideways, the screen brightness is reduced to prevent power from being wasted during periods when the user is not using it.

[0003] However, face detection and face orientation detection using the above-described camera have a large development load related to image recognition and also require high power consumption because it is necessary to capture an image using the camera. Therefore, a method for suppressing power consumption by a simple method using the ToF (Time of Flight) method and detecting the orientation of a person's face has also been disclosed (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, with the ToF method, for example, distance measurement is performed by dividing the detection range into an 8x8 grid using a distance sensor, which limits the detection resolution and FoV (Field of View) compared to face detection using a camera. Therefore, depending on the usage situation, only a part of the user's body may be within the FoV, which may result in an unexpected reduction in screen brightness. For example, there is a concern that the screen brightness may be mistakenly reduced even when the user is using the device, such as when using a clamshell-type (notebook) personal computer with the hinge angle wide open or when the user's posture is poor.

[0006] This invention has been made in view of the above circumstances, and one of its objectives is to provide an information processing device and a control method that perform screen brightness control using the ToF method more appropriately. [Means for solving the problem]

[0007] The present invention has been made to solve the above 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 the distance to an object for each measurement unit; a second sensor for detecting the angle of the first sensor with respect to a preset reference direction; a memory for temporarily storing distance information indicating the distance for each measurement unit measured by the first sensor; and a processor for executing processing based on the distance information for each measurement unit. The processor performs a person detection process to detect the range of a person within the detection range based on the distance information for each measurement unit; a face direction determination process to determine the orientation of the person's face based on the distance information for each measurement unit within the range of the person detected within the detection range; and a screen brightness reduction process to reduce the screen brightness of the display unit based on the detection results from the person detection process and the face direction determination process. If the angle detected using the second sensor is greater than or equal to 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.

[0008] In the above-described 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, and when the angle detected using the second sensor is greater than or equal to a predetermined threshold, the processor may disable the screen brightness reduction process when no person is detected within the detection range by the person detection process, and when a person is detected within the detection range by the person detection process, the processor may 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-described information processing device, the processor may, when the angle detected using the second sensor is greater than or equal to a predetermined threshold and the person detection process detects a person's range within the detection range, determine whether the orientation of the face is in a first direction facing the information processing device by the face direction determination process if the size of the detected person's range is within a predetermined first range, fix the face direction detection result by the face direction determination process to the first direction if the size of the detected person's range is outside the first range, and reduce the screen brightness of the display unit by the screen brightness reduction process if the face direction detection result by the face direction determination process is not in the first direction.

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

[0011] The above-described information processing device comprises a first housing on which the first sensor is provided, a second housing, and a rotation mechanism that connects the first housing and the second housing so as to be rotatable from a closed first state in which the first surface of the first housing and the 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, wherein the second sensor may be a sensor for detecting the degree of opening corresponding to the rotation of the first housing and the second housing as the angle of the first sensor with respect to the reference direction.

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

[0013] Furthermore, an information processing device according to a second aspect of the present invention comprises: a first sensor for dividing a predetermined detection range into a plurality of measurement units and measuring the distance to an object for each measurement unit; a second sensor for detecting the angle of the first sensor with respect to a preset reference direction; a memory for temporarily storing distance information indicating the distance for each measurement unit measured by the first sensor; and a processor for executing processing based on the distance information for each measurement unit, wherein the processor performs a person detection process for detecting the range of a person within the detection range based on the distance information for each measurement unit, and based on the distance information for each measurement unit within the range of a person detected within the detection range... The system performs a face direction determination process to determine the orientation of a person's face and a screen brightness reduction process to reduce the screen brightness of the display unit. If the angle detected using the second sensor is less than a predetermined threshold, the screen brightness reduction process is performed based on the detection results from the person detection process and the face direction determination process. If the angle detected using the second sensor is greater than or equal to the predetermined threshold, the screen brightness reduction process is disabled if the person detection process does not detect a person within the detection range, and the screen brightness reduction process is performed to reduce the screen brightness of the display unit based on the detection results from the face direction determination process.

[0014] Furthermore, an information processing device according to a third aspect of the present invention comprises: a first sensor for dividing a predetermined detection range into a plurality of measurement units and measuring the distance to an object for each measurement unit; a memory for temporarily storing distance information indicating the distance for each measurement unit measured by the first sensor; and a processor for executing processing based on the distance information for each measurement unit, wherein the processor performs a person detection process for detecting the range of a person within the detection range based on the distance information for each measurement unit; a face direction determination process for determining the orientation of a person's face based on the distance information for each measurement unit within the range of a person detected within the detection range; and The system performs a person detection process and a screen brightness reduction process that reduces the screen brightness of the display unit based on the detection results from the face direction determination process. 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 orientation of the face is in a first direction that is facing forward to the self-information processing device. When the size of the range of the detected person is outside the first range, the detection result of the face direction determination process is fixed to the first direction. If the detection result of the face direction determination process is not in the first direction, the screen brightness reduction process reduces the screen brightness of the display unit.

[0015] Furthermore, an information processing device according to a fourth aspect of the present invention comprises: a first sensor for dividing a predetermined detection range into a plurality of measurement units and measuring the distance to an object for each measurement unit; a memory for temporarily storing distance information indicating the distance for each measurement unit measured by the first sensor; and a processor for executing processing based on the distance information for each measurement unit. The processor performs: a person detection process for detecting the range of a person within the detection range based on the distance information for each measurement unit; a face direction determination process for determining the orientation of a person's face based on the distance information for each measurement unit within the range of a person detected within the detection range; and a screen brightness reduction process for reducing the screen brightness of the display unit based on the 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 detected person, if the distance to the person is less than a predetermined distance, the face direction determination process detects that the orientation of the face is within a first direction range including the first direction which is facing forward to the information processing device, and it is determined to be the first direction. If the distance to the person is greater than or equal to the predetermined distance, the face direction determination process detects that the orientation of the face is within a second direction range which is wider than the first direction range, and it is determined to be the first direction. If 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, the face direction determination process detects that the orientation of the face is within a second direction range, and it is determined to be the first direction.

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

[0017] Furthermore, a control method for an information processing apparatus according to a sixth aspect of the present invention, comprising: a first sensor for dividing a predetermined detection range into a plurality of measurement units and measuring the distance to an object for each measurement unit; a second sensor for detecting the angle of the first sensor with respect to a preset reference direction; a memory for temporarily storing distance information indicating the distance for each measurement unit measured by the first sensor; and a processor for executing processing based on the distance information for each measurement unit, the control method for an information processing apparatus comprising the steps of: the processor performing a person detection process to detect the range of a person present within the detection range based on the distance information for each measurement unit; and the range of a person detected within the detection range for each measurement unit The process includes the steps of: performing a face direction determination process to determine the orientation of a person's face based on distance information; and, if the angle detected using the second sensor is less than a predetermined threshold, 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 detected using the second sensor is greater than or equal to the predetermined threshold, the screen brightness reduction process is disabled if the person detection process does not detect a person within the detection range, and the screen brightness reduction process is performed to reduce the screen brightness of the display unit based on the detection results of the face direction determination process if the person detection process detects a person within the detection range.

[0018] Furthermore, a control method for an information processing apparatus according to a seventh aspect of the present invention, comprising: a first sensor for dividing a predetermined detection range into a plurality of measurement units and measuring the distance to an object for each measurement unit; a memory for temporarily storing distance information indicating the distance for each measurement unit measured by the first sensor; and a processor for executing processing based on the distance information for each measurement unit, wherein the processor performs a person detection process to detect the range of a person present within the detection range based on the distance information for each measurement unit; and performs a face direction determination process to determine the orientation of the person's face based on the distance information for each measurement unit within the range of a person detected within the detection range. The process includes the steps of: performing a screen brightness reduction process to reduce the screen brightness of the display unit based on the detection results from the person detection process and the face direction determination process, wherein if 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 orientation of the face is in a first direction that is facing the information processing device; if the size of the range of the detected person is outside the first range, the detection result of the face direction determination process fixes the face direction to the first direction; and if the detection result of the face direction determination process is not in the first direction, the screen brightness reduction process reduces the screen brightness of the display unit.

[0019] Furthermore, an information processing apparatus according to an eighth aspect of the present invention, comprising: a first sensor for dividing a predetermined detection range into a plurality of measurement units and measuring the distance to an object for each measurement unit; a memory for temporarily storing distance information indicating the distance for each measurement unit measured by the first sensor; and a processor for executing processing based on the distance information for each measurement unit, the control method for an information processing apparatus includes the steps of: the processor performing a person detection process to detect the range of a person within the detection range based on the distance information for each measurement unit; the processor performing a face direction determination process to determine the orientation of the person's face based on the distance information for each measurement unit within the range of the person detected within the detection range; and the processor performing a screen brightness reduction process to reduce the screen brightness of the display unit based on the 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 process, if the distance to the person is less than a predetermined distance, the face direction determination process determines that the orientation of the face is within a first direction range including the first direction which is facing the information processing device, and if the distance to the person is greater than or equal to the predetermined distance, the face direction determination process determines that the orientation of the face is within a second direction range which is wider than the first direction range, and if 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 orientation of the face is within a second direction range, even if the distance to the person detected by the person detection process is less than a predetermined distance, and the face direction determination process determines that the orientation of the face is within a second direction range. [Effects of the Invention]

[0020] According to the above-described aspect of the present invention, screen brightness control using the ToF method can be performed more appropriately. [Brief explanation of the drawing]

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

Modes for Carrying Out the Invention

[0022] Hereinafter, embodiments of the present invention will be described with reference to the drawings. <The First Embodiment> First, the first embodiment will be described. Figure 1 is a perspective view showing an example of the external configuration of the information processing device 1 according to this embodiment. The information processing device 1 is, for example, a notebook-type (clamshell-type) PC (Personal Computer). The information processing device 1 comprises 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 the axis of rotation formed by the hinge mechanism 15. The opening angle (hinge angle) due to the rotation of the first housing 10 and the second housing 20 is shown as "θ".

[0023] The first enclosure 10 is also called the A cover or display enclosure. The second enclosure 20 is also called the C cover or system enclosure. In the following description, the sides of the first enclosure 10 and the second enclosure 20 that are equipped with the hinge mechanism 15 are referred to as sides 10c and 20c, respectively. The sides of the first enclosure 10 and the second enclosure 20 that are opposite to sides 10c and 20c are referred to as sides 10a and 20a, respectively. In the diagram, the direction from side 20a toward side 20c is referred to as "rear," and the direction from side 20c toward side 20a is referred to as "front." Also, when looking forward from the information processing device 1, the direction toward the right is referred to as "right," and the direction toward the left is referred to as "left." The right sides of the first enclosure 10 and the second enclosure 20 are referred to as sides 10b and 20b, respectively, and the left sides are referred to as sides 10d and 20d, respectively. Furthermore, the state in which the first housing 10 and the second housing 20 overlap and are completely closed (opening angle θ = 0°) is called the "closed state". In the closed state, the faces of the first housing 10 and the second housing 20 facing each other are called the "inner surfaces", and the surface opposite to the inner surface is called the "outer surface". Also, the state in which the first housing 10 and the second housing 20 are open relative to the closed state is called the "open state".

[0024] The appearance of the information processing device 1 shown in Figure 1 is an example of the 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 the user uses the information processing device 1, and is typically used with an opening angle θ of approximately 100 to 140°. The range of the opening angle θ in the open state can be arbitrarily determined according to 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 composed of a liquid crystal display (LCD) or an electroluminescent (EL) display, etc. A ToF sensor 130 is provided in the area surrounding the display unit 110 on the inner surface of the first housing 10. For example, the ToF sensor 130 is positioned on the side surface 10a of the area surrounding the display unit 110. Note that the position of the ToF sensor 130 is just an example, and it may be located in any other place as long as it is possible to measure the distance in the direction facing the display screen of the display unit 110.

[0026] The ToF sensor 130 is a distance measuring sensor that measures the distance to an object (e.g., a person) located in the 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 is composed of a light-emitting unit that emits infrared light and a light-receiving unit that receives the reflected light that comes back when the emitted infrared light is reflected off the surface of an object. The ToF sensor 130 emits infrared light forward at a predetermined sampling period (e.g., 1 Hz) and receives the reflected light of the emitted infrared light, and outputs a distance measuring signal corresponding to the distance to the object (e.g., a person) using the ToF (Time of Flight) method, which converts the time difference from emission to reception into distance.

[0027] Furthermore, a power button 140 is provided on the side 20b of the second enclosure 20. The power button 140 is an operator used by the user to instruct the system to turn the power on or off, transition from standby state to normal operation state, and transition from normal operation state to standby state. Normal operation state is the operating state of the system in which processing can be executed without any particular restrictions, and corresponds, for example, to the S0 state defined in ACPI (Advanced Configuration and Power Interface).

[0028] Standby state is a state in which at least a portion of system processing is restricted, and power consumption is lower than in normal operation. For example, standby state may be a standby state, sleep state, etc., and may be a state equivalent to modern standby in Windows® or S3 state (sleep state) as defined by ACPI. Standby state may also include a state in which the display unit is turned OFF (screen OFF) or a screen locked state. Screen locked is a state in which a pre-set image (e.g., a screen lock image) is displayed on the display unit so that the content being processed cannot be seen, and the device cannot be used until the lock is released (e.g., user authentication).

[0029] Furthermore, a keyboard 151 and a touchpad 153 are provided on the inner surface of the second housing 20 as input devices for receiving user input. Alternatively, a touch sensor may be provided instead of, or in addition to, the keyboard 151 and touchpad 153, or a mouse or external keyboard may be connected. In the configuration where a touch sensor is provided, the area corresponding to the display screen of the display unit 110 may be configured as a touch panel for receiving operations. The input devices may also include a microphone for receiving audio input.

[0030] When the first housing 10 and the second housing 20 are closed, the display unit 110 located on the inner surface of the first housing 10 and the keyboard 151 and touchpad 153 located on the inner surface of the second housing 20 are covered by the other housing surface and are unable to function.

[0031] The information processing device 1 performs HPD (Human Presence Detection) processing to detect a person in front of the information processing device 1 based on the distance measurement signal output by the ToF sensor 130.

[0032] Figure 2 shows an example of the distance measurement range of the ToF sensor 130 according to this embodiment. In the open state, the ToF sensor 130, which is located 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). This ToF sensor 130 is a distance measuring sensor for detecting a person (e.g., a user) in front of it, and the detection range for detecting a person is called the detection range FoV (Field of View). The detection range FoV corresponds to the range of angles that the ToF sensor 130 can measure.

[0033] For example, the ToF sensor 130 divides the detection range FoV into 8x8 measurement units and measures the distance for each unit (measurement unit). Since the purpose is to detect a person (user) using the information processing device 1, distances to objects beyond a certain distance (e.g., 2m) may be excluded from the distance measurement target. Furthermore, it is impossible to measure the distance to objects that are too far away for infrared light to reach.

[0034] The information processing device 1 controls the operating state of its system according to the presence or absence of a person through HPD processing. For example, if the information processing device 1 detects the presence of a person (Presence=True) in front of it from a state where no person is present (Presence=False) while in standby mode, it starts the system and controls it to the normal operating state.

[0035] Furthermore, if the information processing device 1 detects the presence of a person in front of it, it detects the orientation of the person's face based on the distance measurement 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, the state in which the person's face is facing the direction of the information processing device 1 (the direction of the display unit 110) (the state in which the face is facing directly towards the information processing device 1) is defined as the state in which the person is paying attention to the information processing device 1. On the other hand, the 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) (the state in which the face is facing left, right, up, or down, etc., and the face is not facing directly towards the information processing device 1) is defined as the state in which the person is not paying attention to the information processing device 1.

[0036] (Method for determining the direction of the face) Next, a method for determining the orientation of the face based on the distance measurement signal output from the ToF sensor 130 will be described. In this embodiment, the information processing device 1 determines the orientation of the face as front, left, right, up, or down. The left and right orientation refers to the orientation of the face in the horizontal direction corresponding to the rotation direction with respect to the vertical axis passing through the center of the face. The up and down orientation refers to the orientation of the face in the vertical direction corresponding to the rotation direction with respect to the horizontal axis passing through the center of the face.

[0037] Figure 3 is an explanatory diagram of the face orientation determination method according to this embodiment. In this figure, the detection range FoV is divided into 64 measurement units of 8x8 squares, and an example of the distance value for each square (measurement unit) is represented numerically within each square. For example, the distance value for each square is the distance value measured by the ToF sensor 130 at a predetermined period (e.g., every 1 second). Since people move to some extent, the distance value for each square is constantly fluctuating. Therefore, in order to obtain a highly reliable distance value, the distance values ​​measured at a predetermined period (e.g., every 1 second) may be averaged over time.

[0038] In this diagram, the distance values ​​shown in each cell are in millimeters. In the example shown, cells with distance values ​​between 450 and 610 represent the area where the person is located. Cells with distance values ​​of 1000 or more represent the distance of objects on the ceiling or behind the person. Cells where no distance value is displayed indicate that the object is too far away to measure.

[0039] The range of a person is characterized by an edge that is generally mountain-shaped, and the width of the upper part of the torso from the shoulders up being shorter than the width of the shoulders. For example, if the range of cells where the distance measurement value is within 1m (1000mm) and the difference in distance measurement values ​​is small (here, about 450 to 610) has an edge that is mountain-shaped, which has the characteristics of a person, then the information processing device 1 detects that range as the range of a person (i.e., detects the presence of a person). In the illustrated example, the six cells arranged horizontally (left to right) from the cell labeled SL (Shoulder Left) to the cell labeled SR (Shoulder Right) correspond to the shoulder range (shoulder width), and the width of the part above the shoulder range is shorter than the width of the shoulders.

[0040] Furthermore, the information processing device 1 detects the area above the shoulders, with a narrow width on both sides, as the face area. For example, the information processing device 1 detects a 3 (horizontal) x 4 (vertical) grid above the shoulders of a person as the face area. The size of this face area corresponds to the face area of ​​a person located at the distance where the information processing device 1 is being used (keyboard operation is being performed), when the detection range FoV is measured using an 8x8 grid.

[0041] Furthermore, the information processing device 1 may detect the area of ​​the person's face as the 3x3 grid above the shoulder area. Also, if the detection range FoV is measured using measurement units other than 8x8 grids, the face area will also be set to a range that matches the number of measurement units, instead of 3x4 or 3x3 grids.

[0042] As shown in the diagram, the central square within the face area is considered the center of the face. The distance value of the square labeled FT (Face Top) above the central square is considered the distance value of the upper part of the face (forehead). The distance value of the square labeled FB (Face Bottom) below the central square is considered the distance value of the lower part of the face (chin). The distance value of the square labeled FL (Face Left) to the left of the central square is considered the distance value of the left side of the face. The distance value of the square labeled FR (Face Right) to the right of the central square is considered the distance value of the left side of the face.

[0043] Note that the center square within the face area is the center square of the 3x3 grid if the face area is 3x3 squares, but if the face area is 3(horizontal)x4(vertical) squares, it will be either the square in the middle column of the second row or the square in the middle column of the third row. Here, the lower square (the square in the third row) is given priority as the center square.

[0044] Alternatively, the upper cell (the cell in the second row) may be prioritized as the center cell. Furthermore, the distance values ​​of both cells may be tracked, and the cell with the smaller distance value may be prioritized as the center cell, or the cell with the larger variation (movement) in the distance value may be prioritized as the center cell.

[0045] The information processing device 1 determines the orientation of the face based on distance measurements of the upper, lower, left, and right parts of the face. For example, the information processing device 1 determines the vertical orientation of the face based on the difference between the distance measurement of the upper part of the face and the distance measurement of the lower part of the face. The information processing device 1 also determines the horizontal orientation of the face based on the difference between the distance measurement of the left part of the face and the distance measurement of the right part of the face.

[0046] For example, the information processing device 1 determines that the face is facing downwards if the difference between the distance measurement value at the top of the face and the distance measurement value at the bottom of the face is greater than or equal to a predetermined threshold, and the distance measurement value at the top of the face is smaller than the distance measurement value at the bottom of the face. On the other hand, the information processing device 1 determines that the face is facing upwards if the difference between the distance measurement value at the top of the face and the distance measurement value at the bottom of the face is greater than or equal to a predetermined threshold, and the distance measurement value at the bottom of the face is smaller than the distance measurement value at the top of the face.

[0047] Furthermore, the information processing device 1 determines that the face is facing to the right if the difference between the distance measurement value of the left side of the face and the distance measurement value of the right side of the face is greater than or equal to a predetermined threshold, and the distance measurement value of the left side of the face is smaller than the distance measurement value of the right side of the face. On the other hand, the information processing device 1 determines that the face is facing to the left if the difference between the distance measurement value of the left side of the face and the distance measurement value of the right side of the face is greater than or equal to a predetermined threshold, and the distance measurement value of the right side of the face is smaller than the distance measurement value of the left side of the face.

[0048] Furthermore, the information processing device 1 determines that the face is facing forward if 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 is less than a predetermined threshold, and 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 is less than a predetermined threshold. In this way, the information processing device 1 can determine the orientation of the face based on the distance measurement values ​​of the upper part, lower part, left part, and right part of the face.

[0049] The information processing device 1 may determine the orientation of the face in the vertical (up and down) and horizontal (left and right) directions based on which part of the face—the upper, lower, left, and right—has the smallest distance measurement value. Furthermore, the information processing device 1 may determine that the face is facing forward if the difference in distance measurement values ​​between 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 vertical face angle from the difference between the distance measurement value at the top of the face and the distance measurement value at the bottom of the face. Similarly, the information processing device 1 may detect the horizontal face angle from the difference between the distance measurement value at the left side of the face and the distance measurement value at the right side of the face. The information processing device 1 may then determine the orientation of the face (for example, whether it is facing forward or not) based on the vertical and horizontal face angles.

[0051] For example, the information processing device 1 controls the screen brightness of the display unit 110 (dimming control) according to the result of determining the direction of the face. Specifically, when the face is not facing forward (not looking at 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 if the person who was in front of the information processing device 1 is no longer there. In this way, the information processing device 1 can suppress unnecessary power consumption by reducing the screen brightness of the display unit 110 when there is no user or when there is a user but they are not looking at the information processing device 1. This process of reducing screen brightness will be referred to as the "screen brightness reduction process" below.

[0052] Furthermore, during this screen brightness reduction process, when the user's face is again facing forward (i.e., when the user is looking at the information processing device 1), the information processing device 1 restores the screen brightness to its original level before reduction.

[0053] In the following, the original screen brightness before reduction will be referred to as "standard brightness," and the screen brightness after reduction from standard brightness will be referred to as "low brightness." Low brightness is at least lower than standard brightness, but the lower the brightness, the greater the power saving effect. For example, low brightness may be set to about 0-10% of standard brightness.

[0054] Figure 4 shows an example of screen brightness reduction processing according to this embodiment. For example, the information processing device 1 determines the orientation of the face of a person (user) in front of the information processing device 1 and determines whether the face is facing forward or not.

[0055] Figure 4(A) shows a state where the face is facing forward towards 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, Figure 4(B) shows a state where the face is not facing forward towards 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 Figure 4(A) to the sideways state shown in Figure 4(B), the information processing device 1 reduces the screen brightness of the display unit 110 from standard brightness to low brightness. Also, when the face changes from the sideways state shown in Figure 4(B) to the forward-facing state shown in Figure 4(A), the information processing device 1 returns the screen brightness of the display unit 110 from low brightness to standard brightness.

[0056] In the following, in the person detection process that uses the ToF sensor 130 to detect a person (or area of ​​a person) within the detection range FoV, the detection result indicating that a person (or area of ​​a person) has been detected will be described as "Presence=True," and the detection result indicating that no person (or area of ​​a person) has been detected will be described as "Presence=False." Furthermore, in the face direction determination process that uses the ToF sensor 130 to determine the orientation of a person's face within the detection range FoV, the determination result indicating that the person is facing forward (paying attention to the information processing device 1) will be described as "Attention=True," and the determination result indicating that the person is not facing forward (not paying attention to the information processing device 1) will be described as "Attention=False."

[0057] Here, the person and face detection method using distance information from the ToF sensor 130 has limitations in detection resolution and detection range FoV compared to person and face detection 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, if the user uses the device with a large opening angle θ, the distance measurement direction of the ToF sensor 130 will be directed upwards, causing the detection range FoV to shift upwards and making it difficult for the user's body to be within the detection range FoV. For this reason, conventionally, in order to prevent the screen brightness from being reduced due to the inability to detect a user who is present, the screen brightness reduction process was sometimes disabled when the opening angle θ was large.

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

[0059] The following provides a detailed explanation. The information processing device 1 enables screen brightness reduction processing 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 in both cases: when no person (or range of person) 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, 140-180°), the information processing device 1 disables the screen brightness reduction process if no person (or area of ​​a person) is detected (Presence=False), and enables the screen brightness reduction process if a person (or area of ​​a person) is detected (Presence=True). In other words, when the opening angle θ is large (for example, 140-180°), the information processing device 1 reduces the screen brightness only when the person is not facing forward (Attention=False), and disables the screen brightness reduction process (leaving the screen brightness at standard brightness) if no person (or area of ​​a person) is detected (Presence=False).

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

[0062] Figures 5(B) and (C) show examples where, similar to Figure 5(A), the detection range FoV is shifted upward due to a large opening angle θ, but the detection range FoV may still be included depending on the user's usage (such as posture and positional relationship with the information processing device 1). The information processing device 1 enables screen brightness reduction processing when a person (or the area of ​​the person) is detected (Presence=True).

[0063] In the example shown in Figure 5(B), the screen brightness is reduced because the user is not facing forward (Attention=False). On the other hand, in the example shown in Figure 5(C), the screen brightness is kept at standard brightness because the user is facing forward (Attention=True). This allows for power saving by enabling screen brightness reduction processing when an object (person) is detected (Presence=True) depending on the user's usage state (posture, positional relationship with the information processing device 1, etc.).

[0064] [Hardware configuration of information processing equipment] Next, we will explain the configuration of the information processing device 1 in detail. Figure 6 is a schematic block diagram showing an example of the hardware configuration of the information processing device 1 according to this embodiment. In Figure 6, the components corresponding to each part in Figure 1 are denoted by the same reference numerals. The information processing device 1 consists of 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 performed by the main processing unit 300 and processing by application programs running on the system processing.

[0066] The acceleration sensor 120 includes at least two acceleration sensors. The acceleration sensors 120 are located inside the first housing 10 and the second housing 20, respectively. The acceleration sensors 120 detect the orientation and changes in orientation of the first housing 10 and the second housing 20, respectively. For example, the acceleration sensors 120 detect the acceleration in the three axes of the first housing 10 and the acceleration in the three axes of the second housing 20, and output a detection signal indicating the detection result.

[0067] As mentioned above, the ToF sensor 130 is a distance measuring sensor that measures the distance to an object (e.g., a person) located in front of it using the ToF method. For example, the ToF sensor 130 outputs a distance measuring signal that includes a distance measurement value measured to an object (e.g., a person) located 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 EC200 in response to user operation. The input device 150 is an input unit that receives user input and includes, for example, a keyboard 151 and a touchpad 153. The input device 150 outputs an operation signal indicating the content of the operation to the EC200 in response to operation on the keyboard 151 and the touchpad 153.

[0069] The communication unit 160 connects 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® and a wireless LAN interface such as Wi-Fi®.

[0070] The storage unit 170 is comprised of storage media such as an HDD (Hard Disk Drive), SSD (Solid State Drive), RAM, and ROM. The storage unit 170 stores various programs such as the OS, device drivers, and applications, as well as various data acquired through the operation of these programs.

[0071] The power supply unit 400 supplies power to each part of the information processing device 1 according to its operating status. The power supply unit 400 is equipped with a DC (Direct Current) / DC converter. The DC / DC converter converts the voltage of the DC power supplied from an AC (Alternate Current) / DC adapter or a battery (battery pack) to the voltage required by each part. The power whose voltage has been converted by the DC / DC converter is supplied to each part via each power supply system. For example, the power supply unit 400 supplies power to each part via each power supply system based on control signals input from the EC200.

[0072] The EC200 is a microcomputer comprising a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), and I / O (Input / Output) logic circuits. The EC200's CPU reads a control program (firmware) pre-stored in its ROM, executes the read control program, and performs its functions. The EC200 operates independently of the main processing unit 300, controlling the operation of the main processing unit 300 and managing its operating state. The EC200 is also connected to the power button 140, input device 150, and power supply unit 400, etc.

[0073] For example, the EC200 communicates with the power supply unit 400 to obtain information about the battery status (such as remaining capacity) from the power supply unit 400, and outputs control signals to the power supply unit 400 to control the power supply according to the operating status of each part of the information processing device 1. The EC200 also obtains operation signals from the power button 140 and the input device 150, and outputs operation signals related to the processing of the main processing unit 300 to the main processing unit 300.

[0074] The main processing unit 300 is comprised of a CPU (Central Processing Unit) 301, a GPU (Graphics Processing Unit) 302, a chipset 303, and system memory 304, and is capable of executing various application programs on the OS (Operating System) through system processing based on the OS.

[0075] The CPU 301 is a processor that performs processes based on BIOS programs, OS programs, and application programs running on the OS. For example, the CPU 301 performs startup processes that start the system from a standby state and transition it to a normal operating state, and sleep processes that transition it from a normal operating state to a standby state. The CPU 301 also performs screen brightness reduction processing to reduce the screen brightness of the display unit 110 based on the results of the face orientation determination mentioned above.

[0076] The GPU 302 is connected to the display unit 110. The GPU 302 performs image processing based on the control of the CPU 301 and generates display data. The GPU 302 outputs the generated display data to the display unit 110.

[0077] The chipset 303 has functions as a memory controller and an I / O controller. For example, the chipset 303 controls the reading and writing of data from the system memory 304 and storage unit 170 by the CPU 301 and GPU 302. The chipset 303 also controls the input and output of data from the communication unit 160, display unit 110 and EC200. Furthermore, the chipset 303 has functions as a sensor hub. For example, the chipset 303 acquires detection signals output from the acceleration sensor 120 and distance measurement signals output from the ToF sensor 130.

[0078] System memory 304 is used as a reading area for programs executed by the CPU 301 and as a work area for writing processing data.

[0079] The CPU 301, GPU 302, and chipset 303 may be configured as a single integrated processor, or they may be configured as individual processors, either partially or individually. For example, in normal operation, the CPU 301, GPU 302, and chipset 303 are all operational, but in standby mode, only at least a portion of the chipset 303 is operational.

[0080] [Functional Configuration of Information Processing Equipment] Next, the functional configuration of the information processing device 1 that performs the screen brightness reduction process described above will be explained. Figure 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 the person's face, and a screen brightness control unit 310 that controls the screen brightness of the display unit 110 based on the detection result and determination result from the detection processing unit 210.

[0081] The detection processing unit 210 has a functional configuration that enables the detection of the opening angle θ, detection of a person, and determination of the direction of the face as described above, when the CPU 301 or chipset 303, etc., executes a specific program, and 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.

[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 people (areas of people) that are within the detection range FoV based on the distance measurement value of the ToF sensor 130. For example, unlike objects, people are constantly moving, so when the person detection unit 212 detects people, it may exclude completely stationary objects from detection targets and only detect objects that are moving (e.g., making minute movements).

[0084] Specifically, as explained with reference to Figure 3, for example, the person detection unit 212 obtains distance values ​​for each of the 64 measurement units (8x8 grids) within the detection range FoV, which is divided into 64 measurement units, based on the distance measurement signal output from the ToF sensor 130. The person detection unit 212 then detects the area as the area of ​​a person if the edges of the area where distance measurement values ​​are obtained within 1m (1000mm) and the difference in distance measurement values ​​is small (for example, around 450 to 610) form a mountain shape with human characteristics. The person detection unit 212 outputs the detection result from the person detection process to the detection result output unit 215.

[0085] When the person detection unit 212 detects a person (or the area of ​​a person), the face range detection unit 213 performs a face range detection process to detect the area of ​​the person's face. For example, the face range detection unit 213 detects the area of ​​the person's face based on the shape of the edges of the detected area of ​​the person. Specifically, the face range detection unit 213 detects the shoulder area within the area of ​​the person and detects the area above the shoulder area, such as a 3x4 grid or a 3x3 grid, as the face area (see Figure 3).

[0086] The face direction determination unit 214 performs a face direction determination process to determine the orientation of the face based on the distance values ​​within the face range detected by the face range detection unit 213. For example, the face direction determination unit 214 determines the orientation of the face based on the difference in distance values ​​for each of several squares (measurement units) within the face range. For example, as explained with reference to Figure 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 values ​​for the upper, lower, left, and right parts of the face, and determines the orientation of the face (for example, whether it is facing forward or not) based on the detected face angles. The face direction determination unit 214 determines the orientation of the face based on which part of the face range is closest, based on the distance values ​​for each of several squares (measurement units) within the face range.

[0087] The face direction determination unit 214 may also determine whether or not the face is facing forward. The face direction determination unit 214 outputs the result of the face direction determination 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. The detection result output unit 215 may also 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, the detection result output unit 215 outputs "Presence=True" if a person (or area of ​​a person) is detected, and outputs "Presence=False" if no person (or area of ​​a person) is detected.

[0090] Furthermore, the detection result output unit 215 outputs the determination result information from the face direction determination unit 214 to the screen brightness control unit 310. For example, based on the determination result from 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 the CPU 11 executing BIOS and OS programs. For example, the screen brightness control unit 310 includes a brightness reduction processing unit 311 and a timer 312 as functional configurations realized by the execution of 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 result of person detection, and information indicating the result of face orientation determination, and controls the screen brightness of the display unit 110 based on the acquired information.

[0093] The brightness reduction processing unit 311 enables 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 obtains "Presence=False", it controls the screen brightness to low brightness. On the other hand, when the brightness reduction processing unit 311 obtains "Presence=True", it controls the screen brightness to standard brightness when it obtains "Attention=True", and controls the screen brightness to low brightness when it obtains "Attention=False".

[0094] Timer 312 is a timer that measures the waiting time from when the brightness reduction processing unit 311 receives "Attention=False" from the detection processing unit 210 while the brightness reduction processing unit 311 is controlling the screen brightness to low brightness. If the brightness reduction processing unit 311 receives "Attention=False" but receives "Attention=True" before the predetermined waiting time has elapsed, it will not control the screen brightness to low brightness and will remain at standard brightness. If the brightness reduction processing unit 311 does not receive "Attention=True" within the predetermined waiting time after receiving "Attention=False", it will control the screen brightness to low brightness. This prevents the screen brightness from being reduced to low brightness just because the user looks away for a moment while using the information processing device 1. The predetermined waiting time is set in advance, for example, to 10 seconds. Note that this predetermined waiting time may be configured to be configurable by the user.

[0095] [Screen brightness reduction process operation] Next, with reference to Figure 8, the operation of the screen brightness reduction process performed by the screen brightness control unit 310 will be described. Figure 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 with the person's (user's) face facing forward, and the screen brightness is set to standard brightness.

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

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

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

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

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

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

[0102] Here, referring to Figure 9, we will explain the operation of the screen brightness reduction process, in which the information processing device 1 controls the switching between enabling and disabling the screen brightness reduction process according to the opening angle θ. Figure 9 is a flowchart showing an example of screen brightness reduction processing according to the opening angle θ according to this embodiment.

[0103] (Step S201) The brightness reduction processing unit 311 obtains 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°), it proceeds to the process in step S203. On the other hand, if the brightness reduction processing unit 311 determines that the opening angle θ is 140° or greater and 180° or less (140° ≤ θ ≤ 180°), it proceeds to the process in step S205.

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

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

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

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

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

[0109] [Summary of the first embodiment] As described above, the information processing device 1 according to this embodiment divides the detection range FoV (an example of a predetermined detection range) into a plurality of measurement units (e.g., 8 x 8 squares), and includes a ToF sensor 130 (an example of a first sensor) for measuring the distance to an object for each measurement unit, an acceleration sensor 120 (an example of a second sensor) for detecting the angle of the ToF sensor 130 with respect to a preset reference direction (e.g., opening angle θ), a system memory 304 (an example of a memory) for temporarily storing distance values ​​(an example of distance information) indicating the distance for each measurement unit measured by the ToF sensor 130, and a processor (e.g., CPU 301, chipset 303, etc.) that executes processing (e.g., person detection processing, face direction determination processing, etc.) based on the distance values ​​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 values ​​for each measurement unit. In the face direction determination processing, the information processing device 1 determines the orientation of a person's face based on the distance values ​​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, if the angle detected using the acceleration sensor 120 (e.g., opening angle θ) is less than a predetermined threshold (e.g., 0° < θ < 140°), the information processing device 1 enables screen brightness reduction processing and reduces the screen brightness of the display unit 110 based on the determination results from the person detection processing and face direction determination processing. On the other hand, if the angle detected using the acceleration sensor 120 (e.g., opening angle θ) is greater than or equal to a predetermined threshold (e.g., 140° ≤ θ ≤ 180°), the information processing device 1 disables screen brightness reduction processing if no person is detected within the detection range FoV by the person detection processing, and enables screen brightness reduction processing if a person is detected within the detection range FoV by the person detection processing and reduces the screen brightness of the display unit 110 based on the determination results from the face direction determination processing.

[0111] As a result, the information processing device 1 can reduce screen brightness unintentionally, even when the angle of the ToF sensor 130 (e.g., opening angle θ) is large, due to the user's usage conditions (such as posture and positional relationship with the information processing device 1), while also saving power by reducing screen brightness when the user is not facing forward. Therefore, the information processing device 1 can perform screen brightness control using the ToF method more appropriately.

[0112] Furthermore, the information processing device 1 includes a first housing 10 on which a ToF sensor 130 is provided, a second housing 20, and a hinge mechanism 15 (an example of a rotation mechanism) that connects the first housing 10 and the second housing 20 so as to be rotatable from a closed state (first state) where the inner surface of the first housing 10 (an example of a first surface) and the inner surface of the second housing 20 (an example of a second surface) face each other and overlap, to an open state (second state) where they do not overlap. The acceleration sensor 120 is a sensor for detecting the opening angle θ (degree of opening) 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, even when the opening angle θ between the first housing 10 and the second housing 20, where the ToF sensor 130 is installed, is large, the information processing device 1 can suppress unintended reductions in screen brightness due to the user's usage state (such as posture and positional relationship with the information processing device 1), while also reducing screen brightness and saving power when the user is not facing forward. Therefore, the information processing device 1 can perform screen brightness control using the ToF method more appropriately.

[0114] The acceleration sensor 120 may also 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 with respect to the vertical direction, instead of the opening angle θ between the first housing 10 and the second housing 20 where the ToF sensor 130 is installed. This suppresses unintentional reduction of screen brightness due to the user's usage state (such as posture and positional relationship with the information processing device 1), while also reducing screen brightness and saving power when the user is not facing forward. Therefore, the information processing device 1 can perform screen brightness control using the ToF method more appropriately.

[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 comprising: a ToF sensor 130 (an example of a first sensor) for dividing the detection range FoV (an example of a predetermined detection range) into a plurality of measurement units and measuring the distance to an object for each measurement unit; an acceleration sensor 120 (an example of a second sensor) for detecting the angle of the ToF sensor 130 with respect to a preset reference direction (for example, the opening angle θ); a system memory 304 (an example of a memory) for temporarily storing distance values ​​(an example of distance information) indicating the distance for each measurement unit measured by the ToF sensor 130; and a processor (for example, a CPU 301, a chipset 303, etc.) that executes processing (for example, person detection processing, face direction determination processing, etc.) based on the distance values ​​for each measurement unit.

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

[0118] As a result, the control method in the information processing device 1 can suppress unintended reductions in screen brightness due to the user's usage state (such as posture and positional relationship with the information processing device 1), even when the angle of the ToF sensor 130 (e.g., opening angle θ) is large, while also reducing screen brightness and saving power when the user is not facing forward. Therefore, the control method in the information processing device 1 can perform screen brightness control using the ToF method more appropriately.

[0119] Furthermore, the threshold for determining whether 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, when a person (or area of ​​a person) is detected with a large opening angle θ (for example, 140-180°) (Presence=True), a process to enable screen brightness reduction (step S207 in Figure 9) was described. However, when the opening angle θ is large, the detection range FoV shifts upward, so even if a person (or area of ​​a person) is detected, depending on the positional relationship between the person and the information processing device 1, the position of the face may fall outside the detection range FoV, making it impossible to correctly determine the orientation of the face.

[0121] In this case, since a person (or the area containing the person) has been detected, it is assumed that the user is using the information processing device 1. However, because the direction of the face cannot be correctly determined, there is a possibility that the screen brightness will be reduced by setting "Attention=False", which is undesirable. Therefore, in this embodiment, even when a person's area is detected at a large opening angle θ (for example, 140-180°) (Presence=True), if the detected area containing the person is narrow or wide, there is a possibility that the direction of the face cannot be correctly determined. In such cases, the area containing the person is excluded from the face direction determination process and fixed to "Attention=True".

[0122] Figure 10 is an explanatory diagram of the screen brightness reduction process according to this embodiment. Figure 10(A) shows an example where 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 included in the detection range FoV, so it may not be possible to correctly determine the orientation of the face. 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 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 even when a user is present.

[0123] Figure 10(B) shows an example where the detected person's range is narrow. For example, if the number of cells N in the detected person's range is greater than 44 (N>44), a large portion of the person's torso may be within the detection FoV, making it impossible to correctly determine the orientation of the face. Therefore, if the number of cells N in the detected person's range is greater than 44 (N>44), the information processing device 1 excludes the person from the face orientation determination process and fixes "Attention=True". This allows the information processing device 1 to prevent the screen brightness from being unintentionally reduced even when a user is present.

[0124] Furthermore, if the number of squares N within the range of the detected person is between 10 and 44 (10 ≤ N ≤ 44), the information processing device 1 performs a face direction determination process and outputs "Attention=True" or "Attention=False" based on the determination result.

[0125] Figure 11 is a flowchart showing an example of the face direction determination process according to this embodiment. The operation of the face direction determination process according to this embodiment will be explained with reference to Figure 11.

[0126] (Step S301) The detection processing unit 210 detects a person (range of a person) 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 the process in step S303. On the other hand, if the detection processing unit 210 determines that "Presence=True", it proceeds to the process in step S305.

[0127] (Step S303) The detection processing unit 210 outputs "Attention=False" because "Presence=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 between 10 and 44 (10 ≤ N ≤ 44), it 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, it proceeds to the process in 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 face direction determination process. Then, the process proceeds to step S313.

[0132] (Step S313) The detection processing unit 210 fixes the output of the face direction determination result 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) for dividing the detection range FoV (an example of a predetermined detection range) into a plurality of measurement units and measuring the distance to an object for each measurement unit, an acceleration sensor 120 (an example of a second sensor) for detecting the angle of the ToF sensor 130 with respect to a preset reference direction (for example, the opening angle θ), a system memory 304 (an example of a memory) for temporarily storing distance values ​​(an example of distance information) indicating the distance for each measurement unit measured by the ToF sensor 130, and a processor (for example, a CPU 301, chipset 303, etc.) that performs processing (for example, person detection processing, face direction determination processing, etc.) based on the distance values ​​for each measurement unit.

[0134] In the person detection process, the information processing device 1 detects the range of a person within the detection range FoV based on the distance measurement value for each measurement unit. In the face direction determination process, the information processing device 1 determines the orientation 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. Based on the determination results from the person detection process and the face direction determination process, the information processing device 1 performs a screen brightness reduction process to reduce the screen brightness of the display unit 110. If the angle detected using the acceleration sensor 120 (for example, the opening angle θ) is greater than or equal to a predetermined threshold (for example, 140°), 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 FoV by the person detection process.

[0135] As a result, the information processing device 1 can more appropriately control screen brightness using the ToF method by changing the control content of the face direction determination process based on the distance measurement direction of the ToF sensor 130 and the positional relationship with the user.

[0136] For example, if the information processing device 1 detects an angle (e.g., opening angle θ) using the acceleration sensor 120 and the angle is greater than or equal to a predetermined threshold (e.g., 140°), and the person detection process detects a person within the detection range FoV, then 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 the information processing device 1 in a first direction (facing forward) using a face direction determination process. 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), the information processing device 1 fixes the face direction determination result from the face direction determination process to the first direction (facing forward) (Attention = True). Furthermore, if the face direction determination result from the face direction determination process is not the first direction (facing forward), the information processing device 1 reduces the screen brightness of the display unit 110 using a screen brightness reduction process.

[0137] As a result, the information processing device 1 can suppress unintended reductions in screen brightness caused by the face position moving outside the detection range (FoV) due to its position relative to the user, while simultaneously reducing screen brightness and saving power when the user's face is detected but not facing forward. Therefore, the information processing device 1 can perform screen brightness control using the ToF method more appropriately.

[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 comprising: a ToF sensor 130 (an example of a first sensor) for dividing the detection range FoV (an example of a predetermined detection range) into a plurality of measurement units and measuring the distance to an object for each measurement unit; an acceleration sensor 120 (an example of a second sensor) for detecting the angle of the ToF sensor 130 with respect to a preset reference direction (for example, the opening angle θ); a system memory 304 (an example of a memory) for temporarily storing distance values ​​(an example of distance information) indicating the distance for each measurement unit measured by the ToF sensor 130; and a processor (for example, a CPU 301, a chipset 303, etc.) that executes processing (for example, person detection processing, face direction determination processing, etc.) based on the distance values ​​for each measurement unit.

[0139] The control method in the information processing device 1 includes the steps of: the processor performing a person detection process to detect the range of a person within the detection range FoV based on the distance measurement value for each measurement unit; performing a face direction determination process to determine the orientation 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 from the person detection process and the face direction determination process; and, if the angle detected using the acceleration sensor 120 (for example, the opening angle θ) is greater than or equal to a predetermined threshold (for example, 140°), 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.

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

[0141] For example, in the control method of 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 (for example, 10 ≤ N ≤ 44), the face direction determination process determines whether or not the face is facing a first direction. Also, in the control method of the information processing device 1, 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), the face direction detection result by the face direction determination process is fixed to the first direction (front) (Attention = True), and if the face direction detection result by the face direction determination process is not the first direction (front), the screen brightness of the display unit 110 is reduced by the screen brightness reduction process.

[0142] As a result, the control method in the information processing device 1 can suppress unintended reductions in screen brightness caused by the face position moving outside the detection range (FoV) due to the relative position of the user, while simultaneously reducing screen brightness and saving power when the user's face is detected but not facing forward. Therefore, the control method in the information processing device 1 can perform screen brightness control using the ToF method more appropriately.

[0143] Furthermore, the information processing device 1 may change 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 greater than or equal to a predetermined threshold (e.g., 140°). For example, without detecting the angle (e.g., opening angle θ) using the acceleration sensor 120, the information processing device 1 may determine whether the orientation of the face is in a first direction facing the information processing device 1 when the size of the range of a person detected by the person detection process (number of squares N) is within a predetermined first range (e.g., 10 ≤ N ≤ 44), and fix the face direction determination result by the face direction determination process to the first direction (facing forward) when the size of the range of a person detected by the person detection process (number of squares N) is outside the first range (e.g., N < 10, or N > 44) (Attention = True).

[0144] Note that the threshold (first range) for the range of detected individuals (number of cells N) was set to 10 or more and 44 or less (10 ≤ N ≤ 44), but this threshold can be set arbitrarily.

[0145] <Third Embodiment> Next, a third embodiment will be described. The face direction determination unit 214, when determining whether the face is facing forward based on the detected face angle, changes the range of face angles that are determined to be facing forward (FoA: Field of Attention) according to the distance from the person.

[0146] Figure 12 is an explanatory diagram of FoA according to the distance to the person according to this embodiment. When the person is far away, or when the information processing device 1 is viewed from a position farther from the center (for example, farther to the left or right) compared to when the person is close, the FoA used to determine that the face is facing forward is larger when the person is far away compared to when the person is close. In other words, when the face direction determination unit 214 determines whether the face is facing forward based on the detected face angle, it uses a small FoA when the person is close and a large FoA when the person is far away.

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

[0148] Furthermore, while the small FoA and large FoA can be set to 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 to 0±60°.

[0149] In the second embodiment, even when the range of the detected person (number of squares N) is between 10 and 44 (10 ≤ N ≤ 44) and face direction determination processing is performed, if the user is at close range and in an inappropriate posture (for example, a posture where the body is tilted to the side), 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 (number of squares N).

[0150] Figure 13 shows an example of switching FoA at close range according to this embodiment. Compared to when the user is in an appropriate posture as shown in Figure 13(A), when the user is in an inappropriate posture as shown in Figure 13(B), the range of the detected person (number of squares N) decreases. Therefore, even if the distance to the person is less than a predetermined distance (for example, 700 mm), if the range of the person (number of squares N) is less than 25, the face direction determination unit 214 uses a larger FoA to determine whether the face is facing forward or not. This prevents the system from mistakenly detecting that the user's face is not facing forward when using the information processing device 1 in an inappropriate posture, which could unintentionally reduce the screen brightness.

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

[0152] Furthermore, the threshold for the range of people (number of squares N) used to determine whether a user is in an inappropriate posture is not limited to 25, but can be set arbitrarily.

[0153] Figure 14 is a flowchart showing an example of the face direction determination process according to this embodiment. The operation of the face direction determination process according to this embodiment will be explained with reference to Figure 14.

[0154] (Step S401) The detection processing unit 210 detects a person (range of a person) 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 the process in step S403. On the other hand, if the detection processing unit 210 determines that "Presence=True", it proceeds to the process in step S405.

[0155] (Step S403) The detection processing unit 210 outputs "Attention=False" because "Presence=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 of the distance measurement values ​​of the detected person range with a predetermined distance (e.g., 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), it proceeds to the process in 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 mm), it proceeds to the process in step S411.

[0157] (Step S407) If the detection processing unit 210 is far from the person, it starts the face direction determination process using a large FoA. Then it proceeds to the process in 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) The detection processing unit 210 determines whether the range of detected people (number of squares N) is 25 or more in order to determine whether the user's posture is appropriate or inappropriate. If the detection processing unit 210 determines that the range of detected people (number of squares N) is 25 or more, it determines that the user's posture is appropriate and proceeds to step S413. On the other hand, if the detection processing unit 210 determines that the range of detected people (number of squares N) is less than 25, it determines that the user's posture is inappropriate and proceeds to step S417.

[0160] (Step S413) The detection processing unit 210 starts the face direction determination process using a small FoA because the user's posture is appropriate at close range. Then it proceeds to the process in 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 at close range, the detection processing unit 210 starts the face direction determination process using a large FoA. Then, it proceeds to the process in 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) for dividing the detection range FoV (an example of a predetermined detection range) into multiple measurement units and measuring the distance to an object for each measurement unit, an acceleration sensor 120 (an example of a second sensor) for detecting the angle of the ToF sensor 130 with respect to a preset reference direction (e.g., opening angle θ), a system memory 304 (an example of a memory) for temporarily storing distance values ​​(an example of distance information) indicating the distance for each measurement unit measured by the ToF sensor 130, and a processor (e.g., CPU 301, chipset 303, etc.) for executing processing (e.g., person detection processing, face direction determination processing, etc.) based on the distance values ​​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 values ​​for each measurement unit. In the face direction determination processing, the information processing device 1 determines the orientation of a person's face based on the distance values ​​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 based on the detection results from the person detection process and the face direction determination process.

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

[0166] As a result, the information processing device 1 can prevent the screen brightness from unintentionally decreasing due to an inappropriate posture (for example, a posture where the body is tilted to the side) adopted by a user at close range. Therefore, the information processing device 1 can perform screen brightness control using the ToF method more appropriately.

[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 comprising: a ToF sensor 130 (an example of a first sensor) for dividing the detection range FoV (an example of a predetermined detection range) into a plurality of measurement units and measuring the distance to an object for each measurement unit; an acceleration sensor 120 (an example of a second sensor) for detecting the angle of the ToF sensor 130 with respect to a preset reference direction (for example, the opening angle θ); a system memory 304 (an example of a memory) for temporarily storing distance values ​​(an example of distance information) indicating the distance for each measurement unit measured by the ToF sensor 130; and a processor (for example, a CPU 301, a chipset 303, etc.) that executes processing (for example, person detection processing, face direction determination processing, etc.) based on the distance values ​​for each measurement unit.

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

[0169] As a result, the control method in the information processing device 1 can suppress the unintentional reduction of screen brightness caused by a user in close proximity adopting an inappropriate posture (for example, a posture where the body is tilted to the side). Therefore, the control method in the information processing device 1 can perform screen brightness control using the ToF method more appropriately.

[0170] Furthermore, the information processing device 1 may change 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 greater than or equal to a predetermined threshold (e.g., 140°). For example, without detecting the angle (e.g., opening angle θ) using the acceleration sensor 120, if the size of the range of a person detected by the person detection process (number of squares N) 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 is facing 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., a 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 Figure 11) and the face direction determination process according to the third embodiment (see Figure 14) will be described.

[0172] Figure 15 is a flowchart showing an example of the face direction determination process according to this embodiment. The operation of the face direction determination process according to this embodiment will be explained with reference to Figure 15. In Figure 15, the processes corresponding to the processes shown in Figure 11 or Figure 14 are denoted by the same reference numerals.

[0173] (Step S301) The detection processing unit 210 detects a person (range of a person) 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 the process in step S303. On the other hand, if the detection processing unit 210 determines that "Presence=True", it proceeds to the process in step S305.

[0174] (Step S303) The detection processing unit 210 outputs "Attention=False" because "Presence=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 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 10 or greater and 44 or less (10 ≤ N ≤ 44), the detection processing unit 210 proceeds to step S405.

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

[0177] (Step S313) The detection processing unit 210 fixes the output of the face direction determination result 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 of the distance measurement values ​​of the detected person range with a predetermined distance (e.g., 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), it proceeds to the process in 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 mm), it proceeds to the process in step S411.

[0179] (Step S407) If the detection processing unit 210 is far from the person, it starts the face direction determination process using a large FoA. Then it proceeds to the process in 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) The detection processing unit 210 determines whether the range of detected people (number of squares N) is 25 or more in order to determine whether the user's posture is appropriate or inappropriate. If the detection processing unit 210 determines that the range of detected people (number of squares N) is 25 or more, it determines that the user's posture is appropriate and proceeds to step S413. On the other hand, if the detection processing unit 210 determines that the range of detected people (number of squares N) is less than 25, it determines that the user's posture is inappropriate and proceeds to step S417.

[0182] (Step S413) The detection processing unit 210 starts the face direction determination process using a small FoA because the user's posture is appropriate at close range. Then it proceeds to the process in 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 at close range, the detection processing unit 210 starts the face direction determination process using a large FoA. Then, it proceeds to the process in 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 embodiments of this invention have been described in detail above with reference to the drawings, the specific configurations are not limited to the embodiments described above, and include designs and the like that do not depart from the spirit of this invention. For example, the configurations described in the embodiments described above can be combined in any way.

[0187] Furthermore, in the above embodiment, the information processing device 1 detected the orientation of the face using distance values ​​from four cells within the detected face range: upper, lower, left, and right. However, the orientation of the face (upward, downward, or forward) may be detected using distance values ​​from two cells: upper and lower. Alternatively, the orientation of the face (leftward, rightward, or forward) may be detected using distance values ​​from two cells: left and right.

[0188] Furthermore, the information processing device 1 may detect the orientation of the face using distance values ​​from five or more squares within the detected face area (e.g., 3x4 squares, 3x3 squares). For example, the information processing device 1 may detect the orientation of the face using distance values ​​from five squares within the detected face area: the center of the face, the top, the bottom, the left side, and the left side. Alternatively, the information processing device 1 may detect the orientation of the face using distance values ​​from eight squares around the center of the face within the detected face area, or it may detect the orientation of the face using distance values ​​from nine squares including the distance value of the center of the face.

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

[0190] Furthermore, although the above embodiment describes an example in which the ToF sensor 130 is built into the information processing device 1, the configuration 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 of the sides 10a, 10b, 10c, etc.) as an external accessory of the information processing device 1, and may be connected to the information processing device 1 wirelessly or via a wired connection.

[0191] Furthermore, although the above embodiment described a ToF sensor 130 using infrared light as an example of a distance measuring sensor, it is not limited to this. For example, a distance measuring sensor using a laser or ultrasound may also be used.

[0192] The information processing device 1 described above has a computer system inside. The processing in each configuration of the information processing device 1 may be performed by recording a program for realizing the functions of each configuration of the information processing device 1 onto a computer-readable recording medium, loading the program recorded on this recording medium into the computer system, and executing it. Here, "loading the program recorded on the recording medium into the computer system and executing it" includes installing the program into the computer system. Here, "computer system" includes hardware such as the OS and peripheral devices. Furthermore, "computer system" may include multiple computer devices connected via a network including communication lines such as the Internet, WAN, LAN, and dedicated lines. Also, "computer-readable recording medium" refers to portable media such as flexible disks, magneto-optical disks, ROMs, CD-ROMs, and storage devices such as hard disks built into the computer system. Thus, the recording medium storing the program may be a non-transient recording medium such as a CD-ROM.

[0193] Furthermore, the recording medium also includes internal or external recording media accessible from the distribution server for distributing the program. The program may be divided into multiple parts, downloaded at different times, and then combined in each configuration of the information processing device 1. The distribution servers for each of the divided programs may also be different. Moreover, "computer-readable recording media" includes volatile memory (RAM) within computer systems that act as servers or clients when a program is transmitted over a network, which retains the program for a certain period of time. The program itself may also be intended to implement some of the functions described above. Furthermore, the program may be a so-called differential file (differential program) that can implement the functions described above in combination with a program already recorded 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 implemented as an integrated circuit such as an LSI (Large Scale Integration). Each function may be individually processorized, or some or all of them may be integrated into a single processor. In addition, the method of implementing the integrated circuit is not limited to LSIs; it may also be implemented using dedicated circuits or general-purpose processors. Furthermore, if an integrated circuit technology that can replace LSIs emerges due to advances in semiconductor technology, an integrated circuit using that technology may be used.

[0195] Furthermore, the information processing device 1 in the above embodiment is not limited to a notebook PC, but may also be a desktop PC, tablet device, smartphone, game device, multimedia terminal, etc. [Explanation of Symbols]

[0196] 1 Information Processing Device: First Housing, 20 Second Housing, 15 Hinge Mechanism, 110 Display Unit, 120 Accelerometer, 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 multiple measurement units and measuring the distance to an object for each measurement unit, A second sensor for detecting the angle of the first sensor with respect to a preset reference direction, A memory for temporarily storing distance information indicating the distance for each measurement unit measured by the first sensor, A processor that performs processing based on distance information for each unit of measurement, Equipped with, The aforementioned processor, A person detection process that detects the range of people within the detection range based on the distance information for each measurement unit, A face direction determination process is performed to determine the orientation of a person's face based on the distance information for each measurement unit within the range of a person detected within the detection range. A screen brightness reduction process that reduces the screen brightness of the display unit based on the detection results from the person detection process and the face direction determination process, Perform If the angle detected using the second sensor is greater than or equal to 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 aforementioned processor, If the angle detected by the second sensor is less than a predetermined threshold, the screen brightness reduction process is enabled. If the angle detected by the second sensor is greater than or equal to a predetermined threshold, the screen brightness reduction process is disabled if the person detection process does not detect a person within the detection range, and 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 apparatus according to claim 1.

3. The aforementioned processor, If the angle detected by the second sensor is greater than or equal to a predetermined threshold and the person detection process detects a person within the detection range, then if the size of the detected person's range is within a predetermined first range, the face direction determination process determines whether the orientation of the face is in a first direction that is facing the information processing device; if the size of the detected person's range is outside the first range, the face direction detection result from the face direction determination process is fixed to the first direction. If the detection result of the face orientation determined by the face orientation 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 apparatus according to claim 2.

4. The aforementioned processor, Based on the distance information for each measurement unit of the range of the person detected by the person detection process, if the distance to the person is less than a predetermined distance, the face direction determination process determines that the orientation of the face is within the first direction range including the first direction, and if the distance to the person is greater than or equal to the predetermined distance, the face direction determination process determines that the orientation of the face is within the second direction range which is wider than the first direction range, and If the angle detected using the second sensor is greater than or equal to a predetermined threshold and the size of the range of the person detected by the person detection process is within the first range, then, even if the distance to the person detected by the person detection process is less than a predetermined distance, the face direction determination process will determine that the orientation of the face is within the second direction range, and the face direction determination process will determine that the orientation is within the second direction range. The information processing apparatus according to claim 3.

5. The first housing, which is provided with the first sensor, The second cabinet and A rotating mechanism connects the first housing and the second housing so that it can rotate from a closed first state in which the first surface of the first housing and the 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 the degree of opening corresponding to the rotation between the first housing and the second housing, as the angle of the first sensor with respect to the reference direction. The information processing apparatus according to any one of claims 1 to 4.

6. The second sensor is a sensor for detecting the angle of the first sensor with respect to the vertical direction, which is the angle of the first sensor with respect to the reference direction. The information processing apparatus according to any one of claims 1 to 4.

7. A first sensor for dividing a predetermined detection range into multiple measurement units and measuring the distance to an object for each measurement unit, A second sensor for detecting the angle of the first sensor with respect to a preset reference direction, A memory for temporarily storing distance information indicating the distance for each measurement unit measured by the first sensor, A processor that performs processing based on distance information for each unit of measurement, Equipped with, The aforementioned processor, A person detection process that detects the range of people within the detection range based on the distance information for each measurement unit, A face direction determination process is performed to determine the orientation of a person's face based on the distance information for each measurement unit within the range of a person detected within the detection range. A screen brightness reduction process that reduces the screen brightness of the display unit, Perform If the angle detected using the second sensor is less than a predetermined threshold, the screen brightness reduction process is performed based on the detection results from the person detection process and the face direction determination process. If the angle detected by the second sensor is greater than or equal to a predetermined threshold, the screen brightness reduction process is disabled if the person detection process does not detect a person within the detection range, and 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 if the person detection process does detect a person within the detection range. Information processing device.

8. A first sensor for dividing a predetermined detection range into multiple measurement units and measuring the distance to an object for each measurement unit, A memory for temporarily storing distance information indicating the distance for each measurement unit measured by the first sensor, A processor that performs processing based on distance information for each unit of measurement, Equipped with, The aforementioned processor, A person detection process that detects the range of people within the detection range based on the distance information for each measurement unit, A face direction determination process is performed to determine the orientation of a person's face based on the distance information for each measurement unit within the range of a person detected within the detection range. A screen brightness reduction process that reduces the screen brightness of the display unit based on the detection results from the person detection process and the face direction determination process, Perform 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 orientation of the face is in a first direction that is facing forward to the self-information processing device. When the size of the range of the detected person is outside the first range, the face direction detection result from the face direction determination process is fixed to the first direction. If the detection result of the face orientation determined by the face orientation 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 multiple measurement units and measuring the distance to an object for each measurement unit, A memory for temporarily storing distance information indicating the distance for each measurement unit measured by the first sensor, A processor that performs processing based on distance information for each unit of measurement, Equipped with, The aforementioned processor, A person detection process that detects the range of people within the detection range based on the distance information for each measurement unit, A face direction determination process is performed to determine the orientation of a person's face based on the distance information for each measurement unit within the range of a person detected within the detection range. A screen brightness reduction process that reduces the screen brightness of the display unit based on the detection results from the person detection process and the face direction determination process, Perform Based on the distance information for each measurement unit of the range of the person detected by the person detection process, if the distance to the person is less than a predetermined distance, the face direction determination process determines that the orientation of the face is within a first direction range that includes the first direction facing the self-recording information processing device, and if the distance to the person is greater than or equal to the predetermined distance, the face direction determination process determines that the orientation 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, even if the distance to the person detected by the person detection process is less than a predetermined distance, the face direction determination process determines that the orientation of the face is within the range of the second direction, and thus it is determined to be the first direction. Information processing device.

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

11. A control method for an information processing device comprising: a first sensor for dividing a predetermined detection range into a plurality of measurement units and measuring the distance to an object for each measurement unit; a second sensor for detecting the angle of the first sensor with respect to a preset reference direction; a memory for temporarily storing distance information indicating the distance for each measurement unit measured by the first sensor; and a processor for executing processing based on the distance information for each measurement unit, wherein The aforementioned processor, The steps include: performing a person detection process to detect the range of people within the detection range based on the distance information for each measurement unit; The steps include: performing a face direction determination process to determine the orientation of a person's face based on the distance information for each measurement unit within the range of a person detected within the detection range; If the angle detected using the second sensor is less than a predetermined threshold, the steps include: performing a screen brightness reduction process to reduce the screen brightness of the display unit based on the detection results from the person detection process and the face direction determination process; Includes, If the angle detected by the second sensor is greater than or equal to a predetermined threshold, the screen brightness reduction process is disabled if the person detection process does not detect a person within the detection range, and 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 if the person detection process does detect a person within the detection range. Control method.

12. A control method for an information processing device comprising: a first sensor for dividing a predetermined detection range into multiple measurement units and measuring the distance to an object for each measurement unit; a memory for temporarily storing distance information indicating the distance for each measurement unit measured by the first sensor; and a processor for executing processing based on the distance information for each measurement unit, wherein The aforementioned processor, The steps include: performing a person detection process to detect the range of people within the detection range based on the distance information for each measurement unit; The steps include: performing a face direction determination process to determine the orientation of a person's face based on the distance information for each measurement unit within the range of a person detected within the detection range; The steps include: performing a screen brightness reduction process to reduce the screen brightness of the display unit based on the detection results from the person detection process and the face direction determination process; Includes, 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 orientation of the face is in a first direction that is facing the information processing device; when the size of the range of the detected person is outside the first range, the face direction detection result from the face direction determination process is fixed to the first direction. If the detection result of the face orientation determined by the face orientation 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 comprising: a first sensor for dividing a predetermined detection range into multiple measurement units and measuring the distance to an object for each measurement unit; a memory for temporarily storing distance information indicating the distance for each measurement unit measured by the first sensor; and a processor for executing processing based on the distance information for each measurement unit, wherein The aforementioned processor, The steps include: performing a person detection process to detect the range of people within the detection range based on the distance information for each measurement unit; The steps include: performing a face direction determination process to determine the orientation of a person's face based on the distance information for each measurement unit within the range of a person detected within the detection range; The steps include: performing a screen brightness reduction process to reduce the screen brightness of the display unit based on the detection results from the person detection process and the face direction determination process; Includes, Based on the distance information for each measurement unit of the range of the person detected by the person detection process, if the distance to the person is less than a predetermined distance, the face direction determination process determines that the orientation of the face is within a first direction range including the first direction which is facing the information processing device, and if the distance to the person is greater than or equal to the predetermined distance, the face direction determination process determines that the orientation of the face is within a second direction range which 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, even if the distance to the person detected by the person detection process is less than a predetermined distance, the face direction determination process determines that the orientation of the face is within the range of the second direction, and thus it is determined to be the first direction. Control method.

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