Circuit device, physical quantity detection device, electronic apparatus, and moving object

• US 10,254,115 B2
• Filed: 02/16/2016
• Issued: 04/09/2019
• Est. Priority Date: 02/20/2015
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Haneda, Hideo, Sudo, Yasuhiro
• Primary Examiner(s): Lebentritt, Michael
• Application Number:
  US15/044,217
• Publication Number:
  US 20160245652A1
• Time in Patent Office: 1,148 Days
• Field of Search: None
• CPC Class Codes: G01C 19/5614 Signal processing

Abstract

A circuit device includes a drive circuit which drives a vibrating reed; a detection circuit which outputs physical quantity information corresponding to the physical quantity, based on a detection signal according to a physical quantity that is output from the vibrating reed; and an arithmetic processing unit which performs arithmetic processing, based on the physical quantity information from the detection circuit and time interval information that is defined by a drive frequency of the drive circuit.

Claims

1. A circuit device comprising:

a drive circuit which drives a vibrating reed;

a detection circuit which outputs physical quantity information corresponding to the physical quantity, based on a detection signal according to a physical quantity that is output from the vibrating reed; and

an arithmetic processing unit which performs arithmetic processing, based on the physical quantity information from the detection circuit and time interval information that is defined by a stored drive frequency of the drive circuit unaffected by fluctuation,

wherein the detection circuit outputs the physical quantity information with an output period based on a master clock signal, wherein the master clock signal is asynchronous to a reference clock signal that is generated based on a signal of the drive circuit, the signal of the drive circuit having the drive frequency of the drive circuit.

2. The circuit device according to claim 1, wherein the arithmetic processing unit receives the reference clock signal, sets a number of edges of the reference clock signal during a output period duration of the physical quantity information as the time interval information, and performs the arithmetic processing.

3. The circuit device according to claim 1, wherein the arithmetic processing unit performs integration processing to generate an integral based on the physical quantity information as the arithmetic processing.

4. The circuit device according to claim 1, wherein the arithmetic processing unit performs posture arithmetic processing to determine a position based on the physical quantity information as the arithmetic processing.

5. The circuit device according to claim 1, wherein the arithmetic processing unit performs the arithmetic processing for the physical quantity information and outputs after-arithmetic physical quantity information.

6. The circuit device according to claim 5, further comprising:

a register unit; and

a control unit,

wherein the register unit includes an information register which stores the after-arithmetic physical quantity information, and

wherein the control unit performs read processing of the after-arithmetic physical quantity information from the information register in accordance with a read command, and performs processing of resetting an integration processing unit of the arithmetic processing unit to an initial state in accordance with a reset command, wherein the integration processing unit is configured to generate an integral based on the physical quantity information.

7. The circuit device according to claim 6, wherein the control unit performs processing of resetting the integration processing unit of the arithmetic processing unit to an initial state, if the after-arithmetic physical quantity information is read by the read command.

8. The circuit device according to claim 5, wherein the arithmetic processing unit performs the arithmetic processing for the physical quantity information of floating point notation, and outputs the after-arithmetic physical quantity information of fixed-point notation.

9. The circuit device according to claim 1, wherein the arithmetic processing unit performs the arithmetic processing, using an arithmetic coefficient in which a value based on the drive frequency of the drive circuit is set.

10. The circuit device according to claim 9, wherein the arithmetic processing unit performs the arithmetic processing, using the arithmetic coefficient in which a value based on the drive frequency and setting sensitivity of the physical quantity information is set.

11. The circuit device according to claim 1, wherein the arithmetic processing unit performs the arithmetic processing, based on the time interval information which is defined by measurement results of the drive frequency.

12. The circuit device according to claim 11,

wherein the drive frequency information which is set based on measurement results of the drive frequency is written to a non-volatile memory, and

wherein the arithmetic processing unit performs the arithmetic processing, based on the time interval information which is defined by the drive frequency information from the non-volatile memory.

13. The circuit device according to claim 1, wherein the arithmetic processing unit includes:

a counter which is reset by a signal synchronous to an output period of the physical quantity information, and performs a count operation using a signal based on a reference clock signal that is generated based on a signal of the drive circuit; and

a multiplication processing unit which performs multiplication processing based on the physical quantity information and a count value from the counter.

14. The circuit device according to claim 13, wherein the multiplication processing unit receives an arithmetic coefficient in which a value based on the drive frequency of the drive circuit is set, and performs the multiplication processing based on the physical quantity information, the count value, and the arithmetic coefficient.

15. The circuit device according to claim 1,

wherein the detection circuit extracts DC components of the physical quantity information and removes the DC components from the physical quantity information, and

wherein the arithmetic processing unit performs the arithmetic processing, based on the physical quantity information from which the DC components are removed.

18. A physical quantity detection device comprising:

the circuit device according to claim 1; and

the vibrating reed.

19. An electronic apparatus comprising:

the circuit device according to claim 1.

20. A moving object comprising:

the circuit device according to claim 1.

16. A circuit device comprising:

a drive circuit which drives a vibrating reed;

a detection circuit which outputs physical quantity information corresponding to the physical quantity, based on a detection signal according to a physical quantity that is output from the vibrating reed;

a non-volatile memory to which drive frequency information of the drive circuit is written, the drive frequency information comprising a drive frequency of the drive circuit unaffected by fluctuation; and

an arithmetic processing unit which performs arithmetic processing, based on the physical quantity information from the detection circuit and the drive frequency information from the non-volatile memory,

wherein the detection circuit outputs the physical quantity information with an output period based on a master clock signal, wherein the master clock signal is asynchronous to a reference clock signal that is generated based on a signal of the drive circuit, the signal of the drive circuit having the drive frequency of the drive circuit.

17. The circuit device according to claim 16, wherein the non-volatile memory stores the drive frequency information which is set based on measurement results of the drive frequency.