Systems and methods for focusing on objects to capture images thereof

• US 10,101,560 B2
• Filed: 09/04/2015
• Issued: 10/16/2018
• Est. Priority Date: 09/04/2015
• Status: Active Grant

• Current Assignee: MediaTek, Inc.
• Original Assignee: MediaTek, Inc.
• Inventors: Chen, Cheng-Che, Wu, Mu-Hsing, Wei, Yu-Ming
• Primary Examiner(s): Pihulic, Daniel
• Application Number:
  US14/845,957
• Publication Number:
  US 20170068069A1
• Time in Patent Office: 1,138 Days
• CPC Class Codes: G01S 15/08 Systems for measuring distance only indirect measurement G01S15/46
• CPC Class Codes: G01S 7/52004 Means for monitoring or calibrating short-range imaging G01S7/5205
• CPC Class Codes: G02B 7/08 adapted to co-operate with a remote control mechanism
• CPC Class Codes: G02B 7/40 using time delay of the reflected waves, e.g. of ultrasonic waves
• CPC Class Codes: H04N 23/67 Focus control based on electronic image sensor signals

Abstract

A method for focusing on an object to capture an image of that object is provided. The method includes obtaining the travel time between the point in time that an ultrasonic signal is sent and the point in time at which the reflected signal is received. The method also includes obtaining environment information of the electronic device based on location/position information. The method further includes determining local sound speed according to environment information and determining the distance to an object using the local sound speed and the travel time. In addition, the method can include focusing on the object according to the object distance.

Claims

1. A method for focusing in an electronic device capable of capturing images, the method comprising:

obtaining a travel time of an ultrasonic signal travelling to and from an object;

obtaining either or both of location/position information and environment information of the electronic device;

determining a local sound speed according to either or both of the location/position information and the environment information of the electronic device;

determining an object distance between the electronic device and the object according to the local sound speed and the travel time; and

focusing on the object according to the object distance.

2. The method as claimed in claim 1, wherein the obtaining either or both of location/position information and environment information of the electronic device comprises:

receiving location/position information of the electronic device; and

obtaining environment information of the electronic device based, at least in part, on the received location/position information of the electronic device.

3. The method as claimed in claim 2, wherein obtaining environment information of the electronic device based, at least in part, on the received location/position information of the electronic device comprises receiving the environment information of the electronic device corresponding to a location or position indicated by the location or the position information, by connecting to the Internet.

4. The method as claimed in claim 1, wherein the obtaining location/position information of the electronic device is performed by utilizing one or more of GPS, WiFi, BT beacon, GSM, GPRS, and WCDMA.

5. The method as claimed in claim 1, wherein the environment information comprises temperature data, humidity data, pressure data, wind speed data, and/or wind direction data.

6. The method as claimed in claim 1, wherein determining the local sound speed comprises referring to a local sound speed look-up table containing local sound speeds corresponding to different environmental data values.

7. The method as claimed in claim 1, wherein determining the local sound speed comprises determining the local sound speed according to a location/position indicated by the received location/position information.

8. The method as claimed in claim 1, further comprising adjusting a frequency and/or amplitude of the ultrasonic signal according to the travel time.

9. The method as claimed in claim 1, further comprising obtaining the number of motor steps or a focal distance for adjusting a lens according to the object distance.

10. The method as claimed in claim 9, wherein the obtaining the number of motor steps for adjusting the lens according to the object distance comprises referring to a motor steps look-up table containing the number of motor steps/focal distance corresponding to different object distances.

11. The method as claimed in claim 1, further comprising:

obtaining an estimated object distance between the electronic device and the object by using a different focusing method;

calibrating a local sound speed look-up table according to the estimated object distance and the travel time.

12. An electronic device, comprising:

a sound speed analyzer configured to obtain a local sound speed according to either or both of location/position information and environment information of the electronic device; and

an object distance detecting module comprising a transmitter configured to transmit an ultrasonic signal and a receiver configured to receive the ultrasonic signal, wherein the object distance detecting module is configured to obtain a travel time of the ultrasonic signal travelling to and from an object, detect an object distance between the electronic device and the object according to the local sound speed and the travel time of the ultrasonic signal, and provide the object distance for focusing on the object according to the object distance.

13. The electronic device as claimed in claim 12, wherein the object distance detecting module further comprises:

a time analyzer configured to calculate the travel time between a transmitted time of the ultrasonic signal from the transmitter and a received time of the ultrasonic signal received by the receiver; and

a distance analyzer configured to determine the object distance between the electronic device and the object according to the local sound speed provided by the sound speed analyzer and the travel time provided by the time analyzer.

14. The electronic device as claimed in claim 13, further comprising:

a lens unit, comprising a lens; and

a motor connected to the lens unit and configured to move the lens to focus on the object according to the object distance.

15. The electronic device as claimed in claim 12, wherein the sound speed analyzer comprises:

a positioning unit, configured to receive the location/position information of the electronic device; and

a sound speed converter configured to obtain the local sound speed according to the environment information which is obtained at least based on the location/position information.

16. The electronic device as claimed in claim 15, wherein the sound speed analyzer further comprises:

a network unit, configured to access a data base and obtain the environment information from the data base according to the location/position information.

17. The electronic device as claimed in claim 15, wherein the positioning unit comprises one or more of GPS, WiFi, BT beacon, GSM, GPRS, and WCDMA.

18. The electronic device as claimed in claim 12, wherein the environment information comprises temperature data, humidity data, pressure data, wind speed data, and/or wind direction data.

19. The electronic device as claimed in claim 12, wherein the object distance detecting module further comprises a signal corrector configured to adjust a frequency and/or amplitude of the ultrasonic signal transmitted by the transmitter according to the travel time.

20. The electronic device as claimed in claim 12, further comprising an image capturing module, configured to determine a focal distance or the number of motor steps according to the object distance and to focus the object using the focal distance or the number of motor steps.

21. An electronic device, comprising:

a time analyzer, configured to obtain a travel time of an ultrasonic signal travelling to and from an object;

a positioning unit, configured to receive location/position information of the electronic device;

a sound speed converter, configured to determine a local sound speed according to either or both of the location/position information and environment information of the electronic device; and

a distance analyzer, configured to determine an object distance between the electronic device and the object according to the local sound speed and the travel time, and provide the object distance for focusing on the object according to the object distance.

22. The electronic device as claimed in claim 21, further comprising a network unit, configured to obtain the environment information of the electronic device based, at least in part, on the received location/position information of the electronic device.