Photonic MEMS and structures

• US 7,123,216 B1
• Filed: 10/05/1999
• Issued: 10/17/2006
• Est. Priority Date: 05/05/1994
• Status: Expired due to Fees

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: IDC, LLC
• Inventors: Miles, Mark W.
• Primary Examiner(s): Dang, Hung Xuan
• Application Number:
  US09/413,222
• Time in Patent Office: 2,569 Days
• Field of Search: 345/54, 345/96, 345/95, 345/55, 345/79, 345/87, 345/97, 359/322
• US Class Current: 345/54
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: G01J 3/0256 Compact construction
• CPC Class Codes: G01J 3/26 using multiple reflection, e.g. Fabry-Perot interferometer, variable interference filters
• CPC Class Codes: G01L 5/0047 measuring forces due to residual stresses
• CPC Class Codes: G02B 2006/12104 Mirror; Reflectors or the like
• CPC Class Codes: G02B 2006/12109 Filter
• CPC Class Codes: G02B 2006/12126 Light absorber
• CPC Class Codes: G02B 2006/12159 Interferometer
• CPC Class Codes: G02B 2006/12164 Multiplexing; Demultiplexing
• CPC Class Codes: G02B 26/001 based on interference in an adjustable optical cavity interference filters G02B5/28; devices or arrangements using multiple reflections in spectrometry or monochromators G01J3/26
• CPC Class Codes: G02B 26/02 for controlling the intensity of light G02B26/004 takes precedence
• CPC Class Codes: G02B 26/08 for controlling the direction of light in light guides G02B6/35
• CPC Class Codes: G02B 26/0833 the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD G02B26/0825 takes precedence; micromechanical devices in general B81B
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: G02B 6/12007 forming wavelength selective elements, e.g. multiplexer, demultiplexer
• CPC Class Codes: G02B 6/122 Basic optical elements, e.g. light-guiding paths
• CPC Class Codes: G02B 6/1225 comprising photonic band-gap structures or photonic lattices
• CPC Class Codes: G02B 6/13 Integrated optical circuits characterised by the manufacturing method
• CPC Class Codes: G02B 6/266 the optical element being an attenuator
• CPC Class Codes: G02B 6/3536 involving evanescent coupling variation, e.g. by a moving element such as a membrane which changes the effective refractive index mode converters G02B6/14; adjustable lateral coupling between waveguides G02B6/283; electro- optical refractive index variations G02F1/0118
• CPC Class Codes: G02B 6/357 : Electrostatic force electrostatic forces controlling reflecting elements in general G02B26/0841
• CPC Class Codes: G02B 6/3578 : Piezoelectric force piezoelectric forces controlling reflecting elements in general G02B26/0858; piezo-optic devices G02F1/0131
• CPC Class Codes: G02B 6/3584 : constructional details of an associated actuator having a MEMS construction, i.e. constructed using semiconductor technology such as etching MEMS per se B81B, B81C
• CPC Class Codes: G02B 6/43 : Arrangements comprising a plurality of opto-electronic elements and associated optical interconnections
• CPC Class Codes: G09G 2310/02 : Addressing, scanning or driving the display screen or processing steps related thereto
• CPC Class Codes: G09G 2310/06 : Details of flat display driving waveforms
• CPC Class Codes: G09G 3/3466 : based on interferometric effect

Abstract

An interference modulator (Imod) incorporates anti-reflection coatings and/or micro-fabricated supplemental lighting sources. An efficient drive scheme is provided for matrix addressed arrays of IMods or other micromechanical devices. An improved color scheme provides greater flexibility. Electronic hardware can be field reconfigured to accommodate different display formats and/or application functions. An IMod'"'"'s electromechanical behavior can be decoupled from its optical behavior. An improved actuation means is provided, some one of which may be hidden from view. An IMod or IMod array is fabricated and used in conjunction with a MEMS switch or switch array. An IMod can be used for optical switching and modulation. Some IMods incorporate 2-D and 3-D photonic structures. A variety of applications for the modulation of light are discussed. A MEMS manufacturing and packaging approach is provided based on a continuous web fed process. IMods can be used as test structures for the evaluation of residual stress in deposited materials.

Claims

1. A line-at-a-time electronic driving method comprising

applying a bias voltage to rows or columns of a device,

applying data voltages to the columns, in the case when the bias voltage is applied to the rows, or the rows, in the case when the bias voltage is applied to the columns, the data voltages being applied alternately about a value of the bias voltage,

actuation of the device occurring when a difference between the values of the data voltage and a select voltage is above a first predetermined level,

release of the device occurring when the difference between the values of the data voltage and the select voltage is below a second predetermined level lowest, and

the device maintaining its state when the select voltage is at the bias level.

2. The method of claim 1 in which the device comprises multiple MEMS devices.

3. The method of claim 1 in which the bias voltage is within a hysteresis window of the device.

4. The method of claim 3 in which the bias voltage is in the middle of the hysteresis window.

5. The method of claim 1 in which the data voltages include two possible values and the select voltages include two possible values that are applied to the rows or columns of the device such that the difference between one of the select voltages and one of the data voltages is above the first predetermined level, the difference between the other of the select voltages and the one of the data voltages is below the second predetermined level, and the difference between the other of the select voltages and the other of the data voltages is below the second predetermined level.

6. The method of claim 5 in which the difference between the other of the select voltages and one of the data voltages is above the first predetermined threshold.

7. The method of claim 1 in which the select voltages are applied in alternating frames such that voltages of alternate polarity are applied to a selected row in successive frames.

8. The method of claim 1 in which the select voltages are applied in frames, the select voltages being applied to successive rows in separate portions of each frame.

9. The method of claim 1 in which the select voltages are applied in repetitive passes to at least portions of each one of successive frames.

10. The method of claim 1 in which the select voltages are applied to different portions of a frame at different rates.

11. The method of claim 1 in which the first predetermined threshold is about 9 volts adn the second predetermined threshold is about 0 volts.