Mobile terminal call screen-off method based on the front camera and gravity sensing of a mobile phone

Abstract

The present invention discloses a method for turning off the screen of a mobile terminal during a call based on the front camera and gravity sensing of the mobile phone. The method includes: during a call, obtaining the ambient light brightness value through the front camera of the mobile terminal; comparing the obtained ambient light brightness value with the ambient light thresholds under different preset ambient levels by the mobile terminal, and determining whether the screen of the mobile terminal is in a face-attached operation; if it is determined to be a face-attached operation, then determining whether it is an answering posture through the gravity sensor of the mobile terminal, and if it is an answering posture, controlling the mobile terminal to turn off the screen; if it is determined to be a face-attached operation but not an answering posture or it is determined not to be a face-attached operation, then controlling the mobile terminal to turn on the screen. The present invention obtains the ambient light brightness value through the front camera of the mobile terminal to simulate the distance between the screen of the mobile terminal and the user's face, and at the same time simulates the call posture through the gravity sensor to determine whether the call process is a face-attached operation, realizing the functions of turning off the screen when the face is attached and turning on the screen when away from the screen. It not only has low cost, but also high reliability and strong versatility.

Description

Technical Field

[0001] The present invention relates to mobile terminal technology, and particularly to a method for turning off the screen of a mobile terminal during a call based on the front camera and gravity sensing of a mobile phone. Background Art

[0002] As a kind of intelligent device, the mobile terminal brings great convenience to people in life. Among them, the call function is one of the basic functions of the mobile terminal. During a call, in order to reduce power consumption and prevent misoperation, the mobile terminal usually turns off the touch screen and the display screen, and then turns on the touch screen and the display screen again after the call ends or the call is interrupted.

[0003] There are mainly two existing methods for the mobile terminal to turn off the screen during a call. The first is to monitor through a proximity light sensor to turn off the screen when the phone is close, which requires the mobile terminal to be equipped with a proximity light sensor. However, adding a proximity light sensor increases the cost of the mobile terminal. The other is to turn off the screen during a call by detecting the proximity of the touch screen. This requires the screen or touch screen to support the analog proximity function. However, not all mobile terminal screens or touch screens support the analog proximity function. Therefore, how to provide a mobile terminal call screen-off method with low cost, strong versatility and good reliability has become an objective need. Summary of the Invention

[0004] The present invention provides a method for turning off the screen of a mobile terminal during a call based on the front camera and gravity sensing of a mobile phone, which is used to solve the problems of high cost and weak versatility existing in the existing mobile terminal call screen-off methods.

[0005] To achieve the purpose of the present invention, the present invention provides a method for turning off the screen of a mobile terminal during a call based on the front camera and gravity sensing of a mobile phone, and the method includes:

[0006] During a call, obtain the ambient light brightness value through the front camera of the mobile terminal;

[0007] The mobile terminal compares the obtained ambient light brightness value with the ambient light thresholds under different preset ambient levels, and determines whether the mobile terminal screen is in a face-attached operation;

[0008] If it is determined to be a face-attached operation, then determine whether it is an answering posture through the gravity sensor of the mobile terminal. If it is an answering posture, then control the mobile terminal to turn off the screen;

[0009] If it is determined to be a face-attached operation, but not an answering posture or it is determined not to be a face-attached operation, then control the mobile terminal to turn on the screen.

[0010] Further, the step of obtaining the ambient light brightness value through the front camera of the mobile terminal during the call includes:

[0011] The front camera of the mobile terminal acquires a byte stream array in the current environment, obtains the current ambient light brightness value, and records the maximum and minimum ambient light brightness values.

[0012] Further, the byte stream array acquired by the front camera of the mobile terminal is stored in the NV21 format, which includes a plurality of luminance values Y and multiple groups of VU arranged after the plurality of luminance values Y.

[0013] Further, the ambient light thresholds under different environment levels are obtained by the lighting device simulating the luminance values when approaching and moving away from the screen under different environment levels.

[0014] Further, the threshold value of each ambient light level is the average value of the difference between the luminance values when approaching and moving away from the screen at that environment level.

[0015] Further, the steps for the mobile terminal to compare the acquired ambient light brightness value with the ambient light thresholds under preset different environment levels and to determine whether the mobile terminal screen is in a face - sticking operation include:

[0016] The mobile terminal determines which ambient light level the acquired ambient light brightness value belongs to;

[0017] The mobile terminal determines whether the difference between the acquired maximum ambient light brightness value and the minimum ambient light brightness value is greater than the ambient light threshold at that level. If so, it is determined that the mobile terminal screen is in a face - sticking operation.

[0018] Further, when the mobile terminal determines that the difference between the acquired maximum ambient light brightness value and the minimum ambient light brightness value is greater than the ambient light threshold at that level, it determines whether the current ambient light brightness value is in the same ambient light level.

[0019] Further, the steps for determining whether the ambient light brightness value is in the same ambient light level include:

[0020] If the time when the current ambient light brightness value becomes darker is less than or equal to the preset light - sensing change time, it is in the same ambient light level, and it is determined that the mobile terminal screen is in a face - sticking operation;

[0021] If the time when the current ambient light brightness value becomes darker is greater than the preset light - sensing change time, it is determined that the ambient light has become darker, and the ambient light level is re - matched.

[0022] Further, the steps for determining whether it is an answering posture by the gravity sensor of the mobile terminal include:

[0023] By simulating answering data multiple times, the gravitational acceleration satisfies:

[0024] FloatMath.sqrt(deltaX * deltaX + deltaY * deltaY + deltaZ * deltaZ) > 0.4

[0025] And when it simultaneously satisfies Math.abs(X) > 4, Y > 3, and Math.abs(Z) < 5, it is determined as the answering posture.

[0026] Wherein, X, Y, and Z are respectively the coordinate values of the screen of the mobile terminal.

[0027] Further, before the step of determining whether it is the answering posture by using the gravity sensor of the mobile terminal, the following is included:

[0028] When the user answers the call, the standard position of the mobile terminal is corrected based on the current position of the mobile terminal.

[0029] The beneficial effects of the present invention are as follows: The present invention obtains the ambient light brightness value through the front camera of the mobile terminal, simulates the distance between the screen of the mobile terminal and the user's face through the brightness value, and simultaneously simulates the call posture through the gravity sensor to determine whether the operation during the call is a face - sticking operation, realizing the function of turning off the screen when sticking to the face and turning on the screen when away from the screen. The present invention uses the existing front camera to simulate the distance between the screen and the user's face, without requiring a proximity light sensor, nor does it require the touch screen to support the proximity - like function. It not only has low cost, but also high reliability and strong versatility.

[0030] On the other hand, it determines whether the current environment is at the same environment level by the time when the ambient light brightness value becomes darker, thereby avoiding misjudgment caused by the darkening of the light brightness when entering a dark environment from a bright environment, and further improving the reliability of determining the face - sticking operation. Brief Description of the Drawings

[0031] Figure 1 is the flowchart of the method of the present invention. Detailed Embodiments

[0032] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the drawings and specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts fall within the protection scope of the present invention.

[0033] As Figure 1 shown, the method for turning off the screen during a call of the mobile terminal based on the front camera and gravity sensing of the present invention includes the following steps:

[0034] S101. During the call state, obtain the ambient light brightness value through the front camera of the mobile terminal.

[0035] In this step, when the mobile terminal is in a call state, the ambient light luminance value is obtained through the front camera of the mobile terminal. The mobile terminal is a mobile device with a front camera that can make calls, such as a mobile phone, a tablet computer, a smartwatch, etc. Specifically, the front camera of the mobile terminal obtains a byte stream array in the current environment to obtain the current ambient light luminance value, and records the maximum ambient light luminance value and the minimum ambient light luminance value. The byte stream array obtained by the front camera of the mobile terminal is stored in the NV21 format, which includes multiple luminance values Y and multiple groups of VU arranged after the multiple luminance values Y. In this embodiment, taking the Android system as an example, the NV21 format provided by the default opening of the camera is as follows:

[0036] Y Y Y Y Y Y Y Y V U V U V U V U

[0037] Among them, Y is the luminance value obtained by the front camera of the mobile terminal. By obtaining the Y value, the current ambient light luminance value BV can be obtained, and the maximum ambient light luminance value BVMAX and the minimum ambient light luminance value BVMIN are recorded.

[0038] S102. The mobile terminal compares the obtained ambient light luminance value with the ambient light thresholds under different preset ambient levels, and determines whether the mobile terminal screen is in a face-attached operation.

[0039] In this step, since the light brightness values near and far from the screen are different under different ambient lights, it is necessary to collect the light brightness values near and far from the screen under different ambient lights, so as to accurately determine whether the mobile terminal screen is in a face-to-screen operation. Specifically, the mobile terminal compares the obtained ambient light brightness value with the ambient light thresholds under different ambient levels to determine which ambient level the current ambient light brightness value belongs to. Among them, the ambient light thresholds Environmen[X] under different ambient levels are obtained by simulating with a lighting device, and the threshold for each ambient light level is the average value of the difference in brightness values when approaching and moving away from the screen under that ambient level. In this embodiment, five ambient light levels of strong light Environmen[0], medium light Environmen[1], weak light Environmen[2], dim light Environmen[3], and extremely dim light Environmen[4] are taken as examples for illustration. A lighting instrument is used to simulate the above five levels of ambient light. For example, under strong light (2000 - 10000 lux), the image stream data Xdata

[10] of the front cameras of 10 mobile phones is collected when not approaching, and the data stream Ndata

[10] is collected when approaching. Then, the corresponding brightness values are parsed based on the collected image stream data Xdata

[10] and Ndata

[10] , and the threshold Environmen[0] under strong light is obtained by calculating the average value of the difference between the two brightness values. The thresholds under medium, weak, dim, and extremely dim light environments are obtained in turn.

[0040] Since the light brightness values collected by the front camera are different when approaching and moving away from the screen during a call, it is possible to determine whether the screen is face-to-screen based on the change in the light brightness value. Specifically, after determining that the current ambient light brightness value belongs to the corresponding ambient light level, the mobile terminal determines whether the difference between the maximum ambient light brightness value and the minimum ambient light brightness value obtained currently is greater than the ambient light threshold under that level. If so, it is determined that the mobile terminal screen is in a face-to-screen operation. For example, under strong light, if the difference between the currently obtained maximum ambient light brightness value BVMAX and the minimum ambient light brightness value BVMIN is greater than Environmen[0], that is, BVMAX - BVMIN > Environmen[0], it is determined as a face-to-screen operation.

[0041] In some embodiments, during a call, if the environment changes, for example, from outdoors in sunlight to indoors in the dark, at this time, when BVMAX - BVMIN > Environmen[0], it may lead to a misjudgment of a face - sticking operation due to the darkening of the ambient light. Therefore, such situations need to be excluded to improve reliability. Specifically, when the mobile terminal determines that the difference between the maximum ambient light brightness value and the minimum ambient light brightness value obtained is greater than the ambient light threshold at this level, it is necessary to determine whether the current ambient light brightness value is in the same ambient light level. At this time, while BVMAX - BVMIN > Environmen[0] is required, it is also necessary to ensure that the current BV and BVMIN fluctuate within a certain small range, that is, Math.abs(BVMIN - BV) < preset range value.

[0042] In some embodiments, since it usually takes a relatively long time to enter a dark environment from a bright environment, while a face - sticking operation is an instantaneous process, whether the current ambient light brightness value is in the same ambient light level can be judged by the time when the ambient light brightness value darkens. Specifically, if the time when the current ambient light brightness value darkens is less than or equal to the preset light - sensing change time, it is in the same ambient light level. At this time, the darkening of the ambient light brightness value can be judged as a face - sticking operation on the mobile terminal screen; if the time when the current ambient light brightness value darkens is greater than the preset light - sensing change time, it is judged as a change in ambient light, and the ambient light level needs to be re - matched. Among them, the preset light - sensing change time can be determined according to the actual situation. For example, the action of picking up the mobile terminal usually takes within 0.5 s, so the preset light - sensing change time can be set to 0.5 s. If the time when the current ambient light brightness value darkens exceeds 0.5 s, it is determined that the ambient light has changed.

[0043] In some embodiments, since the brightness value data collected by the front - facing camera is usually 60 groups per second, if only one group of data is used for judgment, it is easy to misjudge. To further improve the reliability of the judged face - sticking operation, multiple consecutive groups of data can be selected for judgment. Specifically, multiple consecutive ambient light brightness values are selected. When the above - mentioned face - sticking operation is satisfied, a valid value is recorded, and the valid values are consecutive. When the number of valid values is greater than 4, it is determined as a face - sticking operation.

[0044] S103. If it is determined as a face - sticking operation, then use the gravity sensor of the mobile terminal to determine whether it is an answering posture. If it is an answering posture, control the mobile terminal to turn off the screen.

[0045] Specifically, determining whether it is an answering posture through the gravity sensor of the mobile terminal is as follows: By simulating answering data multiple times, the gravitational acceleration satisfies:

[0046] FloatMath.sqrt(deltaX*deltaX+deltaY*deltaY+deltaZ*deltaZ)>0.4。

[0047] During the process of a user answering a call, there may be a need to view the screen of the mobile terminal while on the call, such as using the mobile terminal to browse other applications, etc. At this time, the mobile terminal needs to be in a screen-on state.

[0048] This solution can confirm the current posture of the mobile terminal through a gravity sensor to determine whether the user is in an answering state. Specifically, when the user answers a call, the relative position between the user and the mobile terminal is fixed and standard (the mobile terminal is default located directly in front of the user's face at this time). By correcting the standard position of the mobile terminal according to this position, the current position of the mobile terminal can be defined as (0, 10, 2). In this way, when the user is in a special position, such as when the user is lying in bed answering a call, the answering posture of the mobile terminal can also be accurately determined.

[0049] Among them, the X coordinate is defined as the horizontal posture of the mobile terminal. For example, when the screen of the mobile terminal faces left, it is 10, and when the screen of the mobile terminal faces right, it is -10; the Y coordinate is defined as the rotation posture of the mobile terminal. For example, when the earpiece of the mobile terminal faces up and the long side is in a vertical posture, it is 10, and when the earpiece of the mobile terminal faces down and the long side is in a vertical posture, it is -10; the Z coordinate is defined as the vertical posture of the mobile terminal. For example, when the screen of the mobile terminal faces up, it is 10, and when the screen of the mobile terminal faces down, it is -10.

[0050] For example, when the mobile terminal is placed horizontally with the screen facing up, the Z value is 10; when the mobile terminal is placed horizontally with the screen facing down, the Z value is -10; when the mobile terminal is placed with the screen facing left, the X value is 10; when the mobile terminal is placed with the screen facing right, the X value is -10; when the long side of the mobile terminal is placed vertically, the Y value is 10; when the short side of the mobile terminal is vertical, the Y value is 0 respectively.

[0051] Therefore, the standard position of the mobile terminal defined when the user answers a call is that the screen of the mobile terminal faces the user's face, the mobile terminal is in a state where the long side is vertical, and the screen of the mobile terminal is slightly facing up.

[0052] Based on the above standard position, it can be defined here that when Math.abs(X)>4, Y>3, and Math.abs(Z)<5 are satisfied simultaneously, it is determined as the answering posture, where X, Y, and Z are the coordinate values of the mobile terminal screen respectively.

[0053] The above-defined posture of the mobile terminal is that the screen of the mobile terminal cannot be located directly in front of the user's face, and the screen of the mobile terminal faces the user's left face or right face. Therefore, the range of the X value is from -4 to -10 and from 4 to 10.

[0054] In addition, in principle, the mobile terminal should be placed with the earpiece facing up and the long side vertical, that is, the Y value should be greater than 3.

[0055] Finally, the screen of the mobile terminal should be slightly upward or downward, not completely upward or completely downward, so the Z value ranges from -5 to 5.

[0056] When it is determined as a face-touching operation, it is judged whether it is an answering posture through the gravity sensor of the mobile terminal. If it is an answering posture, the mobile terminal is controlled to turn off the screen to prevent accidental operations during the call.

[0057] The above judgment conditions are only effective when the user answers the phone and the user's position is basically fixed. If the user moves freely when answering the phone, the user can cancel the determination of the X value as needed. In this way, as long as the mobile terminal is in a vertical state with the earpiece facing up, it is defaulted to be in the answering posture.

[0058] S104: If it is determined as a face-touching operation but not an answering posture or it is determined as not a face-touching operation, the mobile terminal is controlled to turn on the screen to meet the user's needs for using other applications.

[0059] The method for the mobile terminal call face-touching screen-off based on the front camera and gravity sensing of the mobile phone in this embodiment obtains the ambient light brightness value through the front camera of the mobile terminal, and simulates the distance between the mobile terminal screen and the user's face through the brightness value. At the same time, the call posture is simulated through the gravity sensor to judge whether it is a face-touching operation during the call, realizing the functions of face-touching screen-off and screen-on when away from the screen. The present invention not only has high reliability, but also does not need to use a proximity light sensor or the touch screen does not need to support the analog proximity function, with low cost and strong versatility.

[0060] Although the present invention has been disclosed through the above embodiments, the protection scope of the present invention is not limited thereto. Without departing from the concept of the present invention, the deformations, substitutions, etc. made to the above components will all fall within the scope of the claims of the present invention.

Claims

1. A method for turning off the screen of a mobile terminal during a call based on a mobile phone front camera and gravity sensor, characterized in that: The method includes: In the call state, the ambient light brightness value is obtained through the front camera of the mobile terminal; The mobile terminal compares the acquired ambient light brightness value with the preset ambient light thresholds under different environmental levels, and determines whether the mobile terminal screen is in close contact with the face; wherein the ambient light thresholds under different environmental levels are obtained by simulating the brightness values ​​of the screen close to and far from the screen under different environmental levels by a lighting device; If it is determined to be a face-to-face operation, determining whether it is an answering posture through the gravity sensor of the mobile terminal, and if it is an answering posture, controlling the mobile terminal to turn off the screen; If it is determined to be a face-to-face operation, but not a call answering posture or it is determined not to be a face-to-face operation, control the mobile terminal to light up the screen; In the call state, the step of obtaining the ambient light brightness value through the front camera of the mobile terminal includes: The front camera of the mobile terminal obtains the byte stream array in the current environment, obtains the current ambient light brightness value, and records the maximum ambient light brightness value and the minimum ambient light brightness value; The mobile terminal compares the acquired ambient light brightness value with preset ambient light thresholds under different environmental levels, and determines whether the mobile terminal screen is in face-to-face operation, including: The mobile terminal determines to which ambient light level the acquired ambient light brightness value belongs; The mobile terminal determines that the difference between the obtained maximum ambient light brightness value and the minimum ambient light brightness value is greater than the ambient light threshold at that level; determines whether the current ambient light brightness value is at the same ambient light level; if the time for the current ambient light brightness value to dim is less than or equal to the preset light perception change time, then they are at the same ambient level, and it is determined that the mobile terminal screen is being operated close to the face; if the time for the current ambient light brightness value to dim is greater than the preset light perception change time, then it is determined that the ambient light is dimming, and the ambient light level is re-matched.

2. The method for turning off the screen during a call on a mobile terminal according to claim 1, wherein: The byte stream array acquired by the front camera of the mobile terminal is stored in NV21 format, which includes multiple brightness values ​​Y and multiple groups of VUs set after the multiple brightness values ​​Y.

3. The method for turning off the screen of a mobile terminal during a call as claimed in claim 1, characterized in that: The threshold of each ambient light level is the average value of the difference in brightness when approaching and moving away from the screen under the ambient light level.

4. The method for turning off the screen of a mobile terminal during a call as claimed in claim 1, characterized in that: The step of determining whether it is an answering posture by the gravity sensor of the mobile terminal comprises: Through multiple simulations of answering data, we can obtain that the gravity acceleration satisfies: FloatMath.sqrt(deltaX*deltaX+deltaY*deltaY+deltaZ* deltaZ)>0.4 If Math.abs(X)>4, Y>3, and Math.abs(Z)<5 are satisfied at the same time, it is judged as the answering posture. Among them, X, Y, and Z are the coordinate values ​​of the mobile terminal screen respectively.

5. The method for turning off the screen during a call on a mobile terminal according to claim 4, characterized in that: The step of determining whether it is an answering posture by the gravity sensor of the mobile terminal includes: When the user answers the call, the standard location of the mobile terminal is corrected based on the current location of the mobile terminal.

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