Piezoelectrically actuated light deflector

Claim 2

A light deflector of the piezoelectrically actuated reflector type comprising first and second light reflectors having respective height and width dimensions, a pair of piezoelectric strips having substantially greater length than thickness extending generally parallel to one another lengthwise and each articulately connected at one end in spaced apart relation along the height dimension of the first reflector and connected at the other end spaced apart relation along the height dimension of the second reflector, means for fixedly supporting the reflector-strip structure at a point with respect to which the strips can extend and contract in response to an electrical drive signal applied thereto, and electrode means connected to the strips for receiving the applied signal to produce extension of one strip and contraction of the other in accordance with the spontaneous polarization of the strips and the magnitude and polarity of tha applied signal whereby each reflector rotates about a respectiVe axis passing therethrough oriented transversely of the length of the strips and parallel to the width dimensions of said reflectors, for deflecting a light beam reflected from one reflector to the other.

Claim 3

The apparatus of claim 1 including means for applying a bias voltage to the strips to establish a predetermined quiescent polarization therein oriented transverse to the strip length whereby repeatability of reflector rotation is obtained in response to a drive signal of given amplitude applied to the strips for increasing the polarization of one strip to cause elongation thereof and decreasing the polarization of the other strip to cause contraction thereof.

Claim 4

The apparatus of claim 1 wherein the length to thickness ratio of the strips is on the order of ten to one or more.

Claim 5

The apparatus of claim 3 wherein the light reflectors have height in the direction of the spacing between the strips and thickness lengthwise of the strips proportioned so that the height to thickness ratio of each reflector is at least equal to the length to thickness ratio of the strips, and the strips are connected to the reflectors along the height dimension thereof at points corresponding to the nodes of the lowest order flexural vibration mode which could occur along the height dimension of a free reflector whereby motion associated with said flexural mode is inhibited.

Claim 6

The apparatus of claim 4 including means for applying a bias voltage to the strips to establish a predetermined quiescent polarization therein oriented transverse to the strip length whereby repeatability of reflector rotation is obtained in response to a drive signal of given amplitude applied to the strips for increasing the polarization of one strip to cause elongation thereof and decreasing the polarization of the other strip to cause contraction thereof.

Claim 7

The apparatus of claim 3 including an additional pair of piezoelectric strips having a length to thickness ratio on the order of ten to one or more extending generally parallel to one another lengthwise in spaced apart relation with the ends thereof articulately connected to the reflectors and disposed in side by side relation with said pair of piezoelectric strips, and wherein the light reflectors have width in the direction of the side by side disposition of the strips and thickness lengthwise of the strips proportioned so that the width to thickness ratio of each reflector is at least equal to the length to thickness ratio of the strips, and the strips are connected to the reflectors along the width dimension thereof at points corresponding to the nodes of the lowest even order free torsional vibration mode which could occur along the width dimension of a free reflector whereby said torsional mode is inhibited.

Claim 8

The apparatus of claim 6 including means for applying a bias voltage to the strips to establish a predetermined quiescent polarization therein oriented transverse to the strip length whereby repeatability of reflector rotation is obtained in response to a drive signal of given amplitude applied to the strips for increasing the polarization of one strip to cause elongation thereof and decreasing the polarization of the other strip to cause contraction thereof.

Claim 9

A light deflector of the piezoelectrically actuated reflector type comprising a pair of piezoelectric strips having a length to thicknss ratio on the order of ten to one or more extending generally parallel to one another lengthwise in spaced apart relation, a light reflector having height in the direction of the spacing between the strips and thickness lengthwise of the strips proportioned so that the reflector height to thickness ratio is at least equal to the length to thickness ratio of the strips, and articulately connected to one end of the strips at points along the height dimension of the reflector corresponding to the nodes of the lowest order flexural vibration mode which could occur along the height dimension of a free reflector whereby motion associAted with said flexural mode is inhibited, and means for fixedly supporting the reflector-strip structure at a point with respect to which the strips can extend and contract in response to an electrical drive signal applied thereto electrode means connected to the strips for receiving an applied drive signal to produce extension of one strip and contraction of the other in accordance with the spontaneous polarization of the strips and the magnitude and polarity of the applied signal whereby the reflector rotates about an axis passing therethrough oriented transversely of the length of the strips for deflecting a light beam incident on the reflector.

Claim 10

A light deflector of the piezoelectrically actuated reflector type comprising a pair of piezoelectric strips having a length to thicknss ratio on the order of ten to one or more extending generally parallel to one another lengthwise in spaced apart relation, a light reflector having height in the direction of the spacing between the strips and thickness lengthwise of the strips proportioned so that the reflector height to thickness ratio is at least equal to the length to thickness ratio of the strips, and articulately connected to one end of the strips at points along the height dimension of the reflector corresponding to the nodes of the lowest order flexural vibration mode which could occur along the height dimension of a free reflector whereby motion associAted with said flexural mode is inhibited, and means for fixedly supporting the reflector-strip structure at a point with respect to which the strips can extend and contract in response to an electrical drive signal applied thereto electrode means connected to the strips for receiving an applied drive signal to produce extension of one strip and contraction of the other in accordance with the spontaneous polarization of the strips and the magnitude and polarity of the applied signal whereby the reflector rotates about an axis passing therethrough oriented transversely of the length of the strips for deflecting a light beam incident on the reflector.

Claim 11

The apparatus of claim 8 including means for applying a bias voltage to the strips to establish a predetermined quiescent polarization therein oriented transverse to the strip length whereby repeatability of reflector rotation is obtained in response to a drive signal of given amplitude applied to the strips for increasing the polarization of one strip to cause elongation thereof and decreasing the polarization of the other strip to cause contraction thereof.