Vibrating gyroscope and electronic device using the same

Details Vibrating gyroscope and electronic device using the same Vibrating gyroscope and electronic device using the same

2001-06-25

2003-12-23

Moller, Richard A. (Department: 2856)

Measuring and testing

Speed, velocity, or acceleration

Angular rate using gyroscopic or coriolis effect

C073S001770

Reexamination Certificate

active

06666090

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to a vibrating gyroscope and an electronic device using the same. More particularly, the present invention relates to a vibrating gyroscope for use in electronic devices such as video cameras having an anti-shake function, car navigation systems, and pointing devices, and to an electronic device using the same.
2. Description of the Related Art
FIG. 13
is a block diagram of a conventional vibrating gyroscope
50
. The basic concept of the vibrating gyroscope
50
shown in
FIG. 13
is disclosed in Japanese Unexamined Patent Application Publication No. 4-215017.
Referring to
FIG. 13
, the vibrating gyroscope
50
includes a vibrator
100
, a sensor circuit
200
, a driving circuit
300
, a signal processing circuit
400
, and a diagnostic circuit
700
.
The vibrator
100
includes a first piezoelectric substrate
101
, and a second piezoelectric substrate
102
. The first piezoelectric substrate
101
has a first sensor electrode
104
and a second sensor electrode
105
on one principal plane thereof, and is polarized in the thickness direction. The second piezoelectric substrate
102
has a driving electrode
106
on one principal plane thereof, and is polarized in the thickness direction. The other principal plane of the first piezoelectric substrate
101
and the other principal plane of the second piezoelectric substrate
102
are bonded via an intermediate electrode
103
. The sensor circuit
200
includes a first charge amp
220
, a second charge amp
221
, and a differential circuit
210
. The driving circuit
300
includes an adder circuit
310
, an automatic gain control (AGC) circuit
320
, and a phase correction circuit
330
. The signal processing circuit
400
includes a detector circuit
410
, a smoothing circuit
420
, and an amplifier circuit
430
.
In the vibrating gyroscope
50
having such a structure, the first and second sensor electrodes
104
and
105
of the vibrator
100
are connected to the first and second charge amps
220
and
221
, respectively. Each of the first and second charge amps
220
and
221
is connected to the adder circuit
310
and the differential circuit
210
. The adder circuit
310
is connected to the AGC circuit
320
, and the AGC circuit
320
is connected to the phase correction circuit
330
. The phase correction circuit
330
is then connected to the driving electrode
106
, the detector circuit
410
, and a diagnostic circuit
700
. The differential circuit
210
is connected to the detector circuit
410
and the diagnostic circuit
700
. The detector circuit
410
is connected to the smoothing circuit
420
, and the smoothing circuit
420
is connected to the amplifier circuit
430
.
In operation, by applying a driving voltage to the driving electrode
106
, the vibrator
100
undergoes flexural vibration in the thickness direction with the longitudinal ends free. When an angular velocity whose axis extends in the longitudinal direction is applied to the vibrator
100
, the Coriolis force causes a bending displacement in the width direction. Hence, signals having the same phase, which are caused by the driving voltage, and charges having different phases are generated at the first and second sensor electrodes
104
and
105
according to the Coriolis force.
The first charge amp
220
converts the charge generated at the first sensor electrode
104
into a voltage, which is then input to the differential circuit
210
and the adder circuit
310
. The second charge amp
221
converts the charge generated at the second sensor electrode
105
into a voltage, which is then input to the differential circuit
210
and the adder circuit
310
. The adder circuit
310
adds the input signals so that the action of the Coriolis force maybe eliminated from the signals, and outputs the resulting signal to the AGC circuit
320
. The AGC circuit
320
amplifies the received signal to provide a fixed amplitude, and inputs the result to the phase correction circuit
330
. The phase correction circuit
330
corrects the phase of the input signal before inputting the driving voltage to the driving electrode
106
and the detector circuit
410
.
The differential circuit
210
subtracts the input signals so that the signal corresponding to the driving signal may be removed from the signals, and inputs the signal corresponding to the Coriolis force to the detector circuit
410
. The detector circuit
410
detects the input signal from the differential circuit
210
in synchronization with the driving voltage, and inputs the result to the smoothing circuit
420
. The smoothing circuit
420
smoothes the input signal, and inputs it to the amplifier circuit
430
, and the amplifier circuit
430
direct-current amplifies the input signal to output a signal corresponding to the angular velocity to the outside.
Since the sensor circuit
200
and the driving circuit
300
are connected to the diagnostic circuit
700
in the vibrating gyroscope
50
, it can be determined whether or not both the sensor circuit
200
and the driving circuit
300
are functioning normally, or whether or not at least one of the sensor circuit
200
and the driving circuit
300
is functioning abnormally.
The conventional vibrating gyroscope
50
includes the diagnostic circuit
700
which is connected to the sensor circuit
200
and the driving circuit
300
, and it is possible to determine whether or not the sensor circuit
200
and/or the driving circuit
300
are functioning normally.
Phenomena which arises as a result of abnormality of the differential circuit
210
and the phase correction circuit
330
can also be determined. For example, it can be determined whether or not there are defects such as breakage, degradation, and connection failure in the first sensor electrode
104
, the second sensor electrode
105
, and the driving electrode
106
of the vibrator
100
, or whether or not a power supply line leading to the driving circuit
300
has been disconnected.
In the conventional vibrating gyroscope
50
, however, only a part of the circuit components that can operate abnormally is monitored, and all abnormalities of the vibrating gyroscope
50
are not determined. In technologies such as vehicle-related technologies, since a variety of components interact with one another to establish a complex system, a small abnormality of one component may lead to fatal damage of the overall system. Therefore, it is desired that the presence of an abnormality of not only a part of a circuit but also all circuit components including a power supply be reliably determined.
However, since the diagnostic circuit
700
is not connected to the signal processing circuit
400
in the conventional vibrating gyroscope
50
, abnormality of the signal processing circuit
400
cannot be examined. Thus, a problem occurs in that an incorrect angular velocity which is output due to an abnormality of the signal processing circuit
400
would not be recognized. Furthermore, since the vibrating gyroscope
50
does not allow abnormalities of a power supply to be examined, another problem occurs in that phenomena which do not arise as a result of abnormalities of the differential circuit
210
and the phase correction circuit
330
, namely, variance in voltage values of the power supply, and incorrect angular velocity which is output due to failure such as noise or instantaneous stop of operation, would not be recognized.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a vibrating gyroscope capable of reliably examining abnormalities if some circuit components are not functioning normally.
It is another object of the present invention to provide a vibrating gyroscope capable of reliably examining abnormalities if a power supply is not functioning normally.
It is still another object of the present invention to provide an electronic device having a reliable system implemented in a vibrating gyroscope capable of reliably examining abnormalities.
To this end, in

Affiliated with

Also associated with

Rating

Vibrating gyroscope and electronic device using the same does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Vibrating gyroscope and electronic device using the same, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Vibrating gyroscope and electronic device using the same will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3107496