Terminal device and illumination control method

Patent metadata

Field	Value
Publication number	US-9767735-B2
Application number	US-201414341150-A
Country	US
Kind code	B2
Filing date	Jul 25, 2014
Priority date	Jul 25, 2014
Publication date	Sep 19, 2017
Grant date	Sep 19, 2017

Abstract

To avoid unintentionally turning off a backlight, a device includes circuitry that is configured to control a backlight to illuminate a display panel of the device; store a first preset time interval for reducing brightness of the backlight; determine that an input has not been received within the first preset time interval; acquire one or more signals from a sensor device corresponding to movement of the device; estimate whether the device is in use based on the one or more signals; and postpone a reduction in the brightness of the backlight based when a result of an estimate indicates that the device is in use.

First claim

The invention claimed is:

1. A device comprising:
circuitry configured to
control a backlight to illuminate a display panel of the device;
store a first preset time interval for reducing brightness of the backlight;
determine that an input has not been received within the first preset time interval;
acquire one or more signals from a sensor device corresponding to movement of the device;
estimate whether the device is in use based on a shape of a distribution of one or more features of a multi-dimensional feature extraction function calculated from the one or more signals,
determine that the device is not in use in response to determining that the shape of the distribution of the one of more features of the multi-dimensional feature extraction function corresponds to a Gaussian distribution;
postpone a reduction in the brightness of the backlight when the multidimensional feature extraction function calculated from the one or more signals indicates that the device is in use regardless of whether or not the input has been received at the device;
and reduce the brightness of the backlight after the first preset time interval when the multi-dimensional feature extraction function calculated from the one or more signals indicates that the device is not in use.

2. The device of claim 1 , wherein the circuitry is configured to measure a time from when an input was last detected at the device.

3. The device of claim 2 , wherein the circuitry is configured to acquire the one or more signals from the sensor device when the measured time reaches a time corresponding to the first preset time interval wherein the first preset time interval corresponds to a predetermined amount of time before a time associated with reduction in the brightness of the backlight and the predetermined amount of time is based on a sample period of a usage estimation calculation.

4. The device of claim 1 , wherein the circuitry is configured to detect an input operation as a touchscreen operation or an operation key operation.

5. The device of claim 1 , wherein the circuitry is configured to reduce the backlight after the first preset time interval has elapsed and the estimate that the device is not in use.

6. The device of claim 1 , wherein the circuitry is configured to store a second preset time interval for turning off the backlight after the backlight has been reduced.

7. The device of claim 6 , wherein the circuitry is configured to turn off the backlight after the second preset time interval has elapsed and the estimate that the device is not in use.

8. The device of claim 1 , wherein the circuitry is configured estimate whether or not the device is in use based on a discriminant calculated from the multi-dimensional feature extraction function.

9. The device of claim 8 , wherein the circuitry is further configured to estimate that the device is in use in a case that the discriminant of the multi-dimensional feature extraction function is greater than a predetermined threshold.

10. The device of claim 9 , wherein the circuitry is configured to perform the estimation of whether or not the device is in use a predetermined number of times.

11. The device of claim 10 , wherein the circuitry is configured to estimate whether or not the device is in use based on a primary process of the multi-dimensional feature extraction function that outputs a signal for one or more axes of the sensor device and a norm of the signal of the one or more axes of the sensor device.

12. The device of claim 11 , wherein the circuitry is configured to estimate whether or not the device is in use based on a secondary process of the multi-dimensional feature extraction function that outputs a non-operation signal, a differentiation signal, and a low pass filter signal based on the output of the primary process of the multi-dimensional feature extraction function.

13. The device of claim 12 , wherein the circuitry is configured to estimate whether or not the device is in use based on a tertiary process of the multi-dimensional feature extraction function computes a mean, a standard deviation, a kurtosis, and a skewness based on the output of the secondary process of the multi-dimensional feature extraction function.

14. The device of claim 13 , wherein the circuitry is configured to estimate whether or not the device is in use based on an orientation of the device or a directional change in acceleration of the device determined from the mean computed by the tertiary process of the multi-dimensional feature extraction function.

15. The device of claim 13 , wherein the circuitry is configured to estimate whether or not the device is in use based on a variance in the acceleration of the device determined from the standard deviation computed by the tertiary process of the multi-dimensional feature extraction function.

16. The device of claim 13 , wherein the circuitry is configured to estimate whether or not the device is in use based on the shape of the distribution of the one or more features of the multi-dimensional feature extraction function, wherein the one or more features include the skewness and the kurtosis computed by the tertiary process of the multi-dimensional feature extraction function.

17. The device of claim 1 , wherein estimating whether or not the device is in use further includes calculating the multi-dimensional feature extraction function as a three-tiered 48-dimension feature value function, wherein
a first tier includes four primary dimensions corresponding to a detection signal for one or more axes of the signal device and a norm of the detection signal of the one or more axes of the signal device;
a second tier includes three secondary dimensions corresponding to a non-operation signal, a differentiation signal, and a low pass filter signal of the four primary dimensions of the first tier; and
a third tier includes three tertiary dimensions corresponding to a mean, a standard deviation, a kurtosis, and a skewness of the three secondary dimensions of the second tier associated with each of the four primary dimensions of the first tier.

18. A method of controlling illumination of a device comprising:
controlling a backlight to illuminate a display panel of the device;
storing a first preset time interval for reducing brightness of the backlight;
determining that an input has not been received within the first preset time interval;
acquiring one or more signals from a sensor device corresponding to movement of the device;
estimating whether the device is in use based on a shape of a distribution of one or more features of a multi-dimensional feature extraction function calculated from the one or more signals;
determining that the device is not in use in response to determining that the shape of the distribution of the one of more features of the multi-dimensional feature extraction function corresponds to a Gaussian distribution;
postponing a reduction in the brightness of the backlight based when a result of the estimate indicates that the device is in use;
and reducing the brightness of the backlight after the first preset time interval when the multi-dimensional feature extraction function calculated from the one or more signals indicates that the device is not in use.

19. A non-transitory computer readable medium having instructions stored therein that, when executed by one or more processors, cause the one or more processors to perform a method of controlling illumination of a device, wherein the device includes a motion sensor, the method comprising:
con

Assignees

• Sony Corp
• Sony Mobile Communications Inc

Inventors

• Mizukami Tomoo
• Watanabe Eri
• Kobayashi Yoshiyuki

Classifications

• H04W52/027

  by controlling a display operation or backlight unit · CPC title

• G09G2330/022

  in absence of operation, e.g. no data being entered during a predetermined time · CPC title

• H04M2250/12

  including a sensor for measuring a physical value, e.g. temperature or motion · CPC title

• H04W52/0254

  detecting a user operation or a tactile contact or a motion of the device · CPC title

• G06F1/3231

  Monitoring the presence, absence or movement of users · CPC title