Vibration type motor, lens apparatus, and electronic device
A vibration type motor includes a vibrator that includes a piezo element, a contacting portion, and a holding portion, and generates a first vibration and a second vibration, a friction member that makes frictional contact with the contacting portion of the vibrator, a holding member that holds the holding portion of the vibrator, and a biasing member that biases the holding portion of the vibrator to the holding member, and a condition of A 3 /A 1 <A 4 /A 2 is satisfied where A 1 and A 2 are respectively amplitudes of the contacting portion in the first vibration and the second vibration, and A 3 and A 4 are respectively amplitudes of the holding portion in the first vibration and the second vibration in a state where the vibrator is not held by the holding member.
1. A vibration type motor comprising:
a vibrator including a piezo element, a contacting portion, and a holding portion, the vibrator being configured to generate a first vibration and a second vibration;
a friction member configured to make frictional contact with the contacting portion of the vibrator;
a holding member configured to hold the holding portion of the vibrator; and
a biasing member configured to bias the holding portion of the vibrator to the holding member,
wherein a condition below is satisfied:
A 3/ A 1< A 4/ A 2,
where A 1 and A 2 are respectively amplitudes of the contacting portion in the first vibration and the second vibration, and A 3 and A 4 are respectively amplitudes of the holding portion in the first vibration and the second vibration in a state where the vibrator is not held by the holding member.
2. The vibration type motor according to claim 1 , wherein the holding portion is provided at a position that is a node of the first vibration and that is not a node of the second vibration.
3. The vibration type motor according to claim 1 , wherein:
the first vibration is a vibration in which the contacting portion is displaced in a driving direction of the vibration type motor, and
the second vibration is a vibration in which the contacting portion is displaced in a direction orthogonal to the driving direction.
4. The vibration type motor according to claim 1 , wherein:
the second vibration is a vibration in which the contacting portion is displaced in a driving direction of the vibration type motor, and
the first vibration is a vibration in which the contacting portion is displaced in a direction orthogonal to the driving direction.
5. The vibration type motor according to claim 1 , wherein the biasing member biases the holding portion to the holding member with a predetermined biasing force so that the vibrator is held by the holding member.
6. The vibration type motor according to claim 1 , wherein when the state in which the vibrator is not held by the holding member is a first state, a state in which the vibrator is held by the holding member is a second state, a change amount of a resonance frequency between the first state and the second state in the second vibration is at least twice a change amount of a resonance frequency between the first state and the second state in the first vibration.
7. The vibration type motor according to claim 1 , wherein when viewed in a direction orthogonal to a contacting surface of the friction member contacting with the contacting portion, the biasing member overlaps with at least a part of each of the vibrator and the holding member.
8. The vibration type motor according to claim 1 , further comprising an adjusting member configured to adjust a biasing force of the biasing member.
9. The vibration type motor according to claim 8 , wherein when the state in which the vibrator is not held by the holding member is a first state, a state in which the vibrator is held by the holding member is a second state, the adjusting member adjusts the biasing force so as to adjust a change amount of a resonance frequency between the first state and the second state in the second vibration.
10. An electronic device comprising:
a vibration type motor; and
an object configured to be driven by the vibration type motor,
wherein the vibration type motor comprising:
a vibrator including a piezo element, a contacting portion, and a holding portion, the vibrator being configured to generate a first vibration and a second vibration;
a friction member configured to make frictional contact with the contacting portion of the vibrator;
a holding member configured to hold the holding portion of the vibrator; and
a biasing member configured to bias the holding portion of the vibrator to the holding member,
wherein a condition below is satisfied:
A 3/ A 1< A 4/ A 2,
where A 1 and A 2 are respectively amplitudes of the contacting portion in the first vibration and the second vibration, and A 3 and A 4 are respectively amplitudes of the holding portion in the first vibration and the second vibration in a state where the vibrator is not held by the holding member.
11. The electronic device according to claim 10 , wherein the electronic device is a lens apparatus and the object is an optical system.
12. A vibration type motor comprising:
a vibrator including a piezo element, a contacting portion, and a holding portion, the vibrator being configured to generate a first vibration and a second vibration;
a friction member configured to make frictional contact with the contacting portion of the vibrator;
a holding member configured to hold the holding portion of the vibrator; and
a biasing member configured to bias the holding portion of the vibrator to the holding member,
wherein the holding portion is provided at a position that is a node of the first vibration and that is not a node of the second vibration.
13. The vibration type motor according to claim 12 , wherein:
the first vibration is a vibration in which the contacting portion is displaced in a driving direction of the vibration type motor, and
the second vibration is a vibration in which the contacting portion is displaced in a direction orthogonal to the driving direction.
14. The vibration type motor according to claim 12 , wherein:
the second vibration is a vibration in which the contacting portion is displaced in a driving direction of the vibration type motor, and
the first vibration is a vibration in which the contacting portion is displaced in a direction orthogonal to the driving direction.
15. The vibration type motor according to claim 12 , wherein the biasing member biases the holding portion to the holding member with a predetermined biasing force so that the vibrator is held by the holding member.
16. The vibration type motor according to claim 12 , wherein when viewed in a direction orthogonal to a contacting surface of the friction member contacting with the contacting portion, the biasing member overlaps with at least a part of each of the vibrator and the holding member.
17. The vibration type motor according to claim 12 , further comprising an adjusting member configured to adjust a biasing force of the biasing member.
18. An electronic device comprising:
a vibration type motor; and
an object configured to be driven by the vibration type motor,
wherein the vibration type motor comprising:
a vibrator including a piezo element, a contacting portion, and a holding portion, the vibrator being configured to generate a first vibration and a second vibration;
a friction member configured to make frictional contact with the contacting portion of the vibrator;
a holding member configured to hold the holding portion of the vibrator; and
a biasing member configured to bias the holding portion of the vibrator to the holding member,
wherein the holding portion is provided at a position that is a node of the first vibration and that is not a node of the second vibration.
19. The electronic device according to claim 18 , wherein the electronic device is a lens apparatus and the object is an optical system.