Inertial force sensor and electronic device using same

• US 9,464,898 B2
• Filed: 02/20/2013
• Issued: 10/11/2016
• Est. Priority Date: 02/21/2012
• Status: Active Grant

• Current Assignee: MOSAID Technologies Inc. (f/k/a Conversant Intellectual Property Management)
• Original Assignee: Panasonic Intellectual Property Management Co., Ltd. (Panasonic Holdings Corporation)
• Inventors: Hattori, Isao, Uemura, Takeshi
• Primary Examiner(s): YANCHUS III, PAUL B
• Application Number:
  US14/379,535
• Publication Number:
  US 20150046737A1
• Time in Patent Office: 1,329 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G01C 19/5776 Signal processing not specific to any of the devices covered by groups G01C19/5607 - G01C19/5719
• CPC Class Codes: G01P 15/08 with conversion into electric or magnetic values
• CPC Class Codes: G01P 15/097 by vibratory elements
• CPC Class Codes: G01P 3/44 for measuring angular speed G01P3/56 takes precedence
• CPC Class Codes: G06F 1/3296 by lowering the supply or operating voltage

Abstract

An inertial force sensor includes the following elements: a sensor element for converting an inertial force into an electrical signal; a sensor signal processor connected to the sensor element, for outputting an inertial force value; and a power controller for controlling electric power supply to the sensor signal processor, based on the inertial force value. When the inertial force value is maintained for a predetermined time period within a predetermined range in which a reference value is the middle value of the range, the power controller reduces the electric power supply to the sensor signal processor and updates the reference value to the inertial force value obtained after a lapse of the predetermined time period.

Claims

1. An inertial force sensor comprising:

a sensor element configured to convert an inertial force into an electrical signal;

a sensor signal processor connected to the sensor element and configured to receive the electrical signal and output an inertial force value; and

a power controller configured to

reduce an electric power supply to the sensor signal processor when the inertial force value is maintained for a predetermined range, and configured to update a middle value of the predetermined range when the inertial force value is maintained for a predetermined time period.

2. The inertial force sensor of claim 1, wherein when the inertial force value exceeds the predetermined range, the power controller is configured to lengthen the predetermined time period.

3. The inertial force sensor of claim 1, wherein when the inertial force value exceeds the predetermined range, the power controller is configured to extend the predetermined range.

4. The inertial force sensor of claim 1, wherein the power controller is configured to confirm the inertial force value on a predetermined cycle, and determine the predetermined time period, using a product of the predetermined cycle and a predetermined number of times.

5. The inertial force sensor of claim 4, wherein when the inertial force value exceeds the predetermined range, the power controller is configured to increase the predetermined number of times.

11. An electronic device comprising:

the inertial force sensor of claim 1; and

a CPU configured to periodically transmit signals to and receive signals from the inertial force sensor,

wherein the CPU is configured to lengthen a cycle of transmission and reception of the signals while the electric power supply to the sensor signal processor is reduced.

6. An inertial force sensor comprising:

a first sensor element configured to convert a first inertial force into an electrical signal;

a second sensor element configured to convert a second inertial force, which is different from the first inertial force, into an electrical signal;

a first sensor signal processor connected to the first sensor element and configured to output a first inertial force value;

a second sensor signal processor connected to the second sensor element and configured to output a second inertial force value; and

a power controller configured to reduce an electric power supply to the second sensor signal processor based on the first inertial force value

when the inertial force value is maintained for a predetermined range, and configured to update a middle value of the predetermined range when the inertial force value is maintained for a predetermined time period.

7. The inertial force sensor of claim 6, wherein when the first inertial force value exceeds the predetermined range, the power controller is configured to lengthen the predetermined time period.

8. The inertial force sensor of claim 6, wherein when the first inertial force value exceeds the predetermined range, the power controller is configured to extend the predetermined range.

9. The inertial force sensor of claim 6, wherein the power controller is configured to confirm the first inertial force value on a predetermined cycle, and determine the predetermined time period, using a product of the predetermined cycle and a predetermined number of times.

10. The inertial force sensor of claim 9, wherein when the first inertial force value exceeds the predetermined range, the power controller is configured to increase the predetermined number of times.

12. An electronic device comprising:

the inertial force sensor of claim 6; and

a CPU configured to periodically transmit signals to and receive signals from the inertial force sensor,

wherein the CPU is configured to lengthen a cycle of transmission and reception of the signals while the electric power supply to the second sensor signal processor is reduced.

13. An inertial force sensor comprising:

a sensor element configured to convert an inertial force into an electrical signal;

a sensor signal processor connected to the sensor element and configured to receive the electrical signal and output an inertial force value; and

a power controller configured to control electric power supply to the sensor signal processor, based on the inertial force value, wherein the power controller includes;

a window part configured to output static signal when the inertial force value is maintained within a predetermined range;

a time measuring part configured to receive the static signal and output an electric power supply reducing signal and a reference value updating signal when the static signal continues for a predetermined time period, the electric power supply reducing signal is configured to reduce the electric power supply to the sensor signal and the reference value updating signal is configured to update a middle value of the predetermined range.

14. The inertial force sensor of claim 13, wherein when the inertial force value exceeds the predetermined range, the power controller is configured to lengthen the predetermined time period.

15. The inertial force sensor of claim 13, wherein when the inertial force value exceeds the predetermined range, the power controller is configured to extend the predetermined range.

16. The inertial force sensor of claim 13, wherein the power controller is configured to confirm the inertial force value on a predetermined cycle, and determine the predetermined time period, using a product of the predetermined cycle and a predetermined number of times.

17. The inertial force sensor of claim 16, wherein when the inertial force value exceeds the predetermined range, the power controller is configured to increase the predetermined number of times.