A piezoelectric material contains a main component containing a perovskite-type metal oxide represented by general formula (1), a first sub-component containing Mn, and a second sub-component containing Bi or Bi and Li. A Mn content relative to 100 parts by weight of the metal oxide is 0.500 parts by weight or less (including 0 parts by weight) in terms of metal, a Bi content relative to 100 parts by weight of the metal oxide is 0.042 parts by weight or more and 0.850 parts by weight or less in terms of metal, and a Li content relative to 100 parts by weight of the metal oxide is 0.028 parts by weight or less (including 0 parts by weight) in terms of metal:
(Ba.sub.1−x−yCa.sub.xSn.sub.y).sub.α(Ti.sub.1−zZr.sub.z)O.sub.3 (where 0.020≦x≦0.200, 0.020≦y≦0.200, 0≦z≦0.085, 0.986≦α≦1.100)  General formula (1).

A vibration type actuator providing a satisfactory actuator performance even when an increase in speed is achieved and having a contact spring. The actuator includes a vibrator equipped with an electrical-mechanical energy conversion element, an elastic member to which the electrical-mechanical energy conversion element is fixed, and a protrusion provided on the elastic member. The vibrator can generate an elliptic movement in the protrusion. A driven body is configured to come into contact with the protrusion and to make a relative movement with respect to the vibrator. The protrusion includes a contact portion having a contact surface contacting the driven body, a continuous side wall portion protruding with respect to one end surface of the elastic member and forming a hollow structure, and a connection portion connecting the contact portion and the side wall portion and exhibiting flexibility in a direction normal to the contact surface.

A piezoelectric element having an improved piezoelectric constant is provided, and a liquid discharge head, an ultrasonic motor, and a dust removing device, each of which uses the above piezoelectric element, are also provided. A piezoelectric element at least includes a pair of electrodes and a piezoelectric material provided in contact with the pair of electrodes, the piezoelectric material is formed of an aggregate of crystal grains containing barium titanate as a primary component, and among the crystal grains of the aggregate, crystal grains at least in contact with the electrodes have dislocation layers in the grains. A liquid discharge head, an ultrasonic motor, and a dust removing device each use the above piezoelectric element.

A vibration wave motor includes a driven body, a vibrator including an annular vibration plate and an annular piezoelectric element, and a vibration damping member, which are arranged in sequence, wherein the vibration plate has, on a side facing the driven body, radially extending groove portions at X places, and, when center depths of the groove portions at X places are sequentially denoted by D1 to DX in a circumferential direction, D1 to DX vary along a curve obtained by superposing one or more sine waves, and wherein the vibration plate is locally supported by the vibration damping member in some or all antinode portions of a standing wave occurring when the vibration wave motor is driven.

A drive device for a vibration actuator, which makes it possible to perform low-speed and stable driving and expand a dynamic range of driving speed. A first switching circuit and a second switching circuit apply a first drive signal and a second drive signal for exciting vibration, to an electromechanical energy conversion element of a vibrating body. A position detection sensor acquires information on a relative position between the vibrating body and a driven body in pressure contact with each other. An MPU switches the first and second drive signal to a third drive signal and a fourth drive signal, respectively, based on the acquired information, to thereby change a position at which a largest one of peaks of amplitude of vibration excited in the vibrating body is formed.

A vibration-type drive apparatus which increases productivity and also prevents undesired vibration from occurring during operation. The vibration-type drive apparatus has an elastic body, a vibrating body having an electro-mechanical energy conversion element mounted on the elastic body, a driven body that is brought into pressure contact with the vibrating body, and a pressurizing member that brings the driven body into pressure contact with the vibrating body. Relative positions of the vibrating body and the driven body change due to vibrations excited in the vibrating body. The pressurizing member has a positioning portion, and the driven body has a fitting-receiving portion that is to be fitted onto the positioning portion. During operation, the positioning portion and the fitting-receiving portion are not in contact with each other.

The present invention provides a lead-free piezoelectric material having a high piezoelectric constant and a high mechanical quality factor in a wide operating temperature range. The piezoelectric material includes a perovskite-type metal oxide represented by Formula (1):
(Ba.sub.1-xCa.sub.x).sub.a(Ti.sub.1-yZr.sub.y)O.sub.3 (1.00≦a≦1.01, 0.125≦x<0.155, and 0.041≦y≦0.074)
as a main component. The metal oxide contains Mn in a content of 0.12 parts by weight or more and 0.40 parts by weight or less based on 100 parts by weight of the metal oxide on a metal basis.

There is provided a piezoelectric material not containing any lead component, having stable piezoelectric characteristics in an operating temperature range, a high mechanical quality factor, and satisfactory piezoelectric characteristics. The piezoelectric material includes a main component containing a perovskite-type metal oxide that can be expressed using the following general formula (1), and subcomponents containing Mn, Li, and Bi. When the metal oxide is 100 parts by weight, the content of Mn on a metal basis is not less than 0.04 parts by weight and is not greater than 0.36 parts by weight, content α of Li on a metal basis is not less than 0.0013 parts by weight and is not greater than 0.0280 parts by weight, and content β of Bi on a metal basis is not less than 0.042 parts by weight and is not greater than 0.850 parts by weight
(Ba.sub.1-xCa.sub.x).sub.a(Ti.sub.1-y-zZr.sub.ySn.sub.z)O.sub.3  (1)
(in the formula (1), 0.09≦x≦0.30, 0.074<y≦0.085, 0≦z≦0.02, and 0.986≦a≦1.02).

Provided is a piezoelectric material that is free of lead and potassium, has satisfactory insulation property and piezoelectricity, and has a high Curie temperature. The piezoelectric material includes a perovskite-type metal oxide represented by the following general formula (1): General formula (1) (Na.sub.xM.sub.1-y)(Zr.sub.z(Nb.sub.1-wTa.sub.w).sub.y(Ti.sub.1-vSn.sub.v).sub.(1-y-z))O.sub.3 where M represents at least any one of Ba, Sr, and Ca, and relationships of 0.80≦x≦0.95, 0.85≦y≦0.95, 0<z≦0.03, 0≦v<0.2, 0≦w<0.2, and 0.05≦1−y−z≦0.15 are satisfied.

Provided is a lead-free piezoelectric material having satisfactory piezoelectric constant and mechanical quality factor in a device driving temperature range (−30° C. to 50° C.) The piezoelectric material includes a main component containing a perovskite-type metal oxide represented by Formula 1, a first auxiliary component composed of Mn, and a second auxiliary component composed of Bi or Bi and Li. The content of Mn is 0.040 parts by weight or more and 0.500 parts by weight or less based on 100 parts by weight of the metal oxide on a metal basis. The content of Bi is 0.042 parts by weight or more and 0.850 parts by weight or less and the content of Li is 0.028 parts by weight or less (including 0 parts by weight) based on 100 parts by weight of the metal oxide on a metal basis. (Ba.sub.1-xCa.sub.x).sub.a(Ti.sub.1-yZr.sub.y)O.sub.3 . . . (1), wherein, 0.030≦x<0.090, 0.030≦y≦0.080, and 0.9860≦a≦1.0200.