Optical: systems and elements – Lens – Fluid
Reexamination Certificate
2001-06-19
2003-03-25
Mack, Ricky (Department: 2873)
Optical: systems and elements
Lens
Fluid
Reexamination Certificate
active
06538823
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to microlenses, and more particularly to liquid microlenses.
DESCRIPTION OF THE RELATED ART
Most tunable microlenses are either gradient index (GRIN) lenses with the refraction index controlled electrostatically or flexible polymeric lenses with the shape controlled mechanically. Both technologies have inherent limitations that impose severe restrictions on the performance of these existing tunable microlenses.
Tunable gradient index lenses have inherent limitations associated with the relatively small electro-optic coefficients found in the majority of electro-optic materials. This results in a small optical path modulation and, therefore, requires thick lenses or very high voltages to be employed. In addition, many electro-optic materials show strong birefringence that causes polarization dependence of the microlens properties.
Mechanically adjustable flexible lenses typically have a substantially wider range of tunability than the gradient index lenses. However, they require external actuation devices, such as micropumps, to operate. Microintegration of such devices involves substantial problems, especially severe in the case where a two-dimensional array of tunable microlenses is required.
Attempts have also been made to use other technologies to produce tunable microlenses, such as liquid microlenses controlled through self assembled monolayers (SAMs). Some of these attempts are described in U.S. Pat. No. 6,014,259 to Wohlstadter, issued Jan. 11, 2000, the entirety of which is hereby incorporated by reference herein. Microlenses utilizing self assembled monolayers, however, also suffer from several problems, including severe limitations on material selection and strong hysteresis leading to the failure of the microlens to return to an original shape after a tuning voltage is disconnected. Additionally, none of the above-described microlenses allow for both lens position adjustment and focal length tuning.
SUMMARY OF THE INVENTION
A tunable liquid microlens includes an insulating layer, a droplet of a transparent conducting liquid disposed on a first surface of the insulating layer and a plurality of electrodes insulated from the droplet by the insulating layer. The plurality of electrodes are disposed such that they may be selectively biased to create a respective voltage potential between the droplet and each of the plurality of electrodes, whereby a contact angle between the droplet and the first surface is variable and the droplet may be repositioned along the first surface. Note that by transparent it is meant transparent at the light frequency of interest, which may or may not be visible.
The tunable liquid microlens allows for both lens position adjustment and focal length tuning. In addition, the tunable liquid microlens provides greater freedom in material selection.
REFERENCES:
patent: 3670130 (1972-06-01), Greedwood
patent: 4030813 (1977-06-01), Kohashi et al.
patent: 4118270 (1978-10-01), Pan et al.
patent: 4137060 (1979-01-01), Timmerman
patent: 4338352 (1982-07-01), Bear et al.
patent: 4406732 (1983-09-01), Kayoun
patent: 4569575 (1986-02-01), Le Pesant et al.
patent: 4653847 (1987-03-01), Berg et al.
patent: 4671609 (1987-06-01), Khoe et al.
patent: 4708426 (1987-11-01), Khoe
patent: 4867521 (1989-09-01), Mallinson
patent: 4948214 (1990-08-01), Hamblem
patent: 5412746 (1995-05-01), Rossberg et al.
patent: 5486337 (1996-01-01), Ohkawa
patent: 5518863 (1996-05-01), Pawluczyk
patent: 5659330 (1997-08-01), Sheridon
patent: 6014259 (2000-01-01), Wohlstadter
patent: 6369954 (2002-04-01), Berge et al.
patent: 196 23 270 (1998-01-01), None
patent: 2 769 375 (1999-04-01), None
Schilling, Andreas et al., Surface Profiles of Reflow Microlens Under the Influence of Surface Tension and Gravity,Opt. Eng.39(8) pp. 2171-2176, Society of Photo-Optical Instrumentation Engineers, Aug. 2000.
Danzebrink, R. et al., “Deposition of Micropatterned Coating Using an Ink-Jet Technique,”Thin Solid Films351, pp. 115-118, Elsevier Science S.A. (1999).
Feng, Chuan Liang, et al., “Reversible Wettability of Photoresponsive Flourine-Containing Azobenzene Polymer in Langmuir-Blodgett Films,”Langmuirvol. 17, No. 15, 2001, pp. 4593-4597, American Checmical Society, published on Web Jun. 22, 2001.
Ichimura, Kunihiro et al., “Light-Driven Motion of Liquids on a Photoresponsive Surface”www.sciencemag.org, Science, vol. 288, Jun. 2, 2000, pp. 1624-1626.
Commander, L.G. et al., “Variable Focal Length Microlenses,”Optics Communications177 (2000), Apr. 15, 2000, pp. 157-170.
Washizu, Masao, “Electrostatic Actuation of Liquid Droplets for Microreactor Applications,” IEEE Transactions on Industry Applications, vol. 34, No. 4, Jul./AUg. 1998, pp. 732-737.
Kroupenkine Timofei N.
Yang Shu
Lucent Technologies - Inc.
Mack Ricky
Morris LLP Duane
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