LIGHT MODULATORS INCORPORATING CENTRALLY ANCHORED DRIVE ELECTRODES
This disclosure provides systems, methods and apparatus for reducing actuation voltage and switch time for an electrostatic actuator capable of actuating a light modulator. In one aspect, a light modulator can be formed on a substrate. The light modulator can include an electrostatic actuator. The electrostatic actuator can include a load beam electrode coupled to a shutter of the light modulator, and a drive beam electrode. The drive beam electrode can have a front end and a rear end. An anchor can be coupled to the drive beam and positioned away from the front end and the rear end.
1 . An apparatus comprising:
a substrate;
a light modulator including a shutter; and
an electrostatic actuator, comprising:
a load beam electrode coupled to the shutter and supporting the shutter above the substrate;
a drive beam electrode having a front portion positioned adjacent to the load beam and a rear portion positioned behind the front portion with respect to the load beam, the drive beam having a front end and a rear end, wherein the load beam extends along substantially the entire length of the drive beam; and
a first anchor coupled to the drive beam electrode and positioned away from the front end and the rear end.
2 . The apparatus of claim 1 , where the first anchor is spaced away from rear end of the drive beam electrode by a distance between about 10% and about 50% of a length of the drive beam electrode.
3 . The apparatus of claim 1 , wherein the rear portion of the drive beam electrode further includes first and second shape adjustment features extending out from the rear portion of the drive beam electrode, away from the load beam electrode.
4 . The apparatus of claim 3 , wherein:
the first shape adjustment feature is positioned between the rear end of the drive beam electrode and the first anchor; and
the second shape adjustment feature is positioned between the front end of the drive beam electrode and the first anchor.
5 . The apparatus of claim 4 , wherein a distance between the shape adjustment feature and the rear end of the drive beam electrode is less than a distance between the shape adjustment feature and the front end of the drive beam electrode.
6 . The apparatus of claim 3 , wherein each of the first and second shape adjustment feature are generally U-shaped sections of the drive beam electrode having widths in the range of about 3 microns to about 10 microns and lengths in the range of about 3 microns to about 10 microns.
7 . The apparatus of claim 1 , further comprising a second anchor coupled to the drive beam electrode and positioned between the first anchor and the front end of the drive beam electrode.
8 . The apparatus of claim 7 , wherein a distance between the first anchor and the rear end of the drive beam electrode is less than a distance between the second anchor and the front end of the drive beam electrode.
9 . The apparatus of claim 1 , wherein the front portion, the rear portion, the front end, and the rear end of the drive beam electrode form a loop.
10 . The apparatus of claim 1 , further comprising:
a display;
a processor capable of communicating with the display, the processor being capable of processing image data; and
a memory device capable of communicating with the processor.
11 . The apparatus of claim 10 , further comprising:
a driver circuit capable of sending at least one signal to the display; and
a controller capable of sending at least a portion of the image data to the driver circuit.
12 . The apparatus of claim 10 , further comprising:
an image source module capable of sending the image data to the processor, wherein the image source module includes at least one of a receiver, transceiver, and transmitter.
13 . The apparatus of claim 10 , further comprising:
an input device capable of receiving input data and to communicate the input data to the processor.
14 . An apparatus comprising:
a substrate;
a light modulator including a shutter; and
an electrostatic actuator, comprising:
a load beam electrode coupled to the shutter and supporting the shutter above the substrate;
a drive beam electrode having a front portion positioned adjacent to the load beam and a rear portion positioned behind the front portion with respect to the load beam, the drive beam having a front end and a rear end, wherein the load beam extends along substantially the entire length of the drive beam;
a first anchor coupled to the drive beam electrode and positioned away from the front end and the rear end of the drive beam electrode; and
a second anchor coupled to the drive beam electrode and positioned between the first anchor and the front end of the drive beam electrode.
15 . The apparatus of claim 14 , where the first anchor is spaced away from rear end of the drive beam electrode by a distance between about 10% and about 50% of a length of the drive beam electrode.
16 . The apparatus of claim 14 , wherein a distance between the first anchor and the rear end of the drive beam electrode is less than a distance between the second anchor and the front end of the drive beam electrode.
17 . The apparatus of claim 14 , wherein the rear portion of the drive beam electrode further comprises a first and second U-shaped sections extending out from the rear portion of the drive beam electrode, away from the load beam electrode.
18 . The apparatus of claim 17 , wherein:
the first U-shaped section is positioned between the rear end of the drive beam electrode and the first anchor; and
the second U-shaped section is positioned between the front end of the drive beam electrode and the first anchor.
19 . The apparatus of claim 17 , wherein each of the first and second U-shaped sections has a width in the range of about 3 microns to about 10 microns and a length in the range of about 3 microns to about 10 microns.
20 . The apparatus of claim 14 , wherein the front portion, the rear portion, the front end, and the rear end of the drive beam electrode form a loop.
21 . An apparatus comprising:
a substrate;
a light modulator including a light blocking means; and
an electrostatic actuator, comprising:
a load beam electrode coupled to the a light blocking means and supporting the a light blocking means above the substrate;
a drive beam electrode having a front portion positioned adjacent to the load beam and a rear portion positioned behind the front portion with respect to the load beam, the drive beam having a front end and a rear end, wherein the load beam extends along substantially the entire length of the drive beam; and
a first anchor coupled to the drive beam electrode and positioned away from the front end and the rear end.
22 . The apparatus of claim 21 , where the first anchor is spaced away from rear end of the drive beam electrode by a distance between about 10% and about 50% of a length of the drive beam electrode.
23 . The apparatus of claim 21 , wherein the rear portion of the drive beam electrode further comprises a first shape adjustment means for causing the front end of the drive beam electrode to bend towards the load beam.
24 . The apparatus of claim 23 , wherein the rear portion of the drive beam electrode further comprises a second shape adjustment means for preventing a central portion of the front portion of the drive beam from bending towards the rear portion of the drive beam.