US 6,584,040 B1 · Electronic timepiece

Abstract

To provide an electronic timepiece enabling reliable detection of a state of rotation of an indication wheel such as a date dial. An ultrasonic motor 1130 has an ultrasonic rotor pinion 1134b. A date dial 1120 is disposed on a main plate 1102 in such a way as to rotate relative thereto. The ultrasonic rotor pinion 1134b is meshed with an intermediate date driving gear wheel 1142a. A date driving wheel 1150 is rotatably disposed on the main plate 1102. A date driving gear wheel 1150b is meshed with an intermediate date driving pinion 1142b. A date driving gear portion 1150b is meshed with a dial gear portion 1120a. A contact point spring 1160 is disposed on a spring guiding portion 1150d. The contact point spring 1160 rotates integrally with the date driving wheel 1150 through the rotation of the date driving wheel 1150. The state of rotation of the date driving wheel 1150 can be detected by contact of the contact point spring 1160 with the contact point pattern 1174.

Claims23

Dependent claims

An electronic timepiece comprising:

a transmission wheel;
a wheel train for rotating the transmission wheel;
a contact point spring comprised of a conductive material and connected to the transmission wheel for rotation therewith;
a printed circuit board having a first detection pattern and a second detection pattern each for contacting the contact point spring during rotation thereof so that in a first detection state only the first detection pattern generates a rotational position detection signal for detecting a rotational position of the transmission wheel, in a second detection state only the second detection pattern generates a rotational position detection signal for detecting a rotational position of the transmission wheel, and in a third detection state both the first and the second detection patterns simultaneously generate rotational position detection signals each for detecting a rotational position of the transmission wheel;
and
a control circuit for determining a case where the third detection state has occurred immediately after the first detection state has been detected and a case where the third detection state has occurred immediately after the second detection state has been detected by distinguishing between the two cases.

3 more elements

An electronic timepiece comprising:

a date signal generating circuit for generating a date signal by counting data with respect to date information;
an ultrasonic motor driving circuit for generating an ultrasonic motor driving signal in accordance with the date signal generated by the date signal generating circuit;
an ultrasonic motor driven by the ultrasonic motor driving signal generated by the ultrasonic motor driving circuit, the ultrasonic motor having an ultrasonic stator, a piezoelectric element bonded to the ultrasonic stator and being driven by the ultrasonic motor driving signal generated by the ultrasonic motor driving circuit to undergo expansion and contraction, and an ultrasonic rotor disposed on the ultrasonic stator to be frictionally driven by expansion and contraction movement of the piezoelectric element to undergo rotation;
a calendar wheel train connected to be rotationally driven by the ultrasonic rotor;
a date finger connected to the calendar wheel train for rotation therewith;
a date dial for displaying date data in accordance with rotation of the date finger;
a transmission wheel connected to be rotationally driven by the ultrasonic rotor;
a contact point spring comprised of a conductive material and connected to the transmission wheel for rotation therewith;
a printed circuit board having at least one detection pattern for contacting the contact point spring during rotation thereof;
and
a control circuit for detecting a rotational position of the transmission wheel in accordance with a rotational position detection signal from the detection pattern when the contact point spring contacts the detection pattern.

8 more elements

An electronic timepiece comprising:

a date signal generating circuit for generating a date signal by counting data with respect to date information;
an ultrasonic motor driving circuit for generating an ultrasonic motor driving signal in accordance with the date signal generated by the date signal generating circuit;
an ultrasonic motor driven by the ultrasonic motor driving signal generated by the ultrasonic motor driving circuit, the ultrasonic motor having an ultrasonic stator, a piezoelectric element bonded to the ultrasonic stator and being driven by the ultrasonic motor driving signal generated by the ultrasonic motor driving circuit to undergo expansion and contraction, and an ultrasonic rotor disposed on the ultrasonic stator to be frictionally driven by expansion and contraction movement of the piezoelectric element to undergo rotation;
a calendar wheel train having an integral date finger and connected to the ultrasonic rotor for rotation therewith;
a date dial for displaying date data in accordance with rotation of the date finger;
a transmission wheel disposed in the calendar wheel train for undergoing rotation in accordance with rotation of the ultrasonic rotor;
a contact point spring comprised of a conductive material and connected to the transmission wheel for rotation therewith;
a printed circuit board having at least one detection pattern for contacting the contact point spring during rotation thereof;
and
a control circuit for detecting a rotational position of the transmission wheel in accordance with a rotational position detection signal from the detection pattern when the contact point spring contacts the detection pattern.

7 more elements

Dependencies are inferred from the claim text.

Electronic timepiece

Life of this patent

Electronic timepiece

Life of this patent

Abstract

Claims23