Optical: systems and elements – Optical modulator – Light wave temporal modulation
Reexamination Certificate
2002-06-28
2004-03-30
Epps, Georgia (Department: 2872)
Optical: systems and elements
Optical modulator
Light wave temporal modulation
C359S237000, C359S291000, C359S298000, C359S224200, C359S572000
Reexamination Certificate
active
06714337
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to a method and device for modulating a light beam. More specifically, this invention relates to a light modulator that is electro-mechanically biased in order to more efficiently modulate optical signals by having an improved gamma response.
BACKGROUND OF THE INVENTION
For light modulating devices, the relationship between an applied signal (usually a voltage) and the resulting output illumination intensity is referred to as the response function or transfer function. For many devices, this response function approximates the function form of I=kV
&ggr;
, where I is the output illumination intensity, V is the applied voltage, k is an arbitrary constant that is selected for the device under consideration, and &ggr; (gamma), which determines the response of the modulator, is the exponent. Thus, light modulators can be described simply by their “gamma” response. A gamma value of 1 describes a light modulator for which the intensity varies linearly with the applied signal. When such a device is used in an image display device, it is difficult to render images without observable granularity or visible “steps” in the darkest portions of an image. Thus, a higher gamma value is desirable for displays. Also, the best image reproduction can be obtained by matching the display device gamma to the manner in which the image was originally recorded, referred to as the source or content gamma. Conventional image source gamma values are in the range of 2 to 3.
What is needed is a light modulator that has a tunable gamma response that can be optimized for a variety of applications.
SUMMARY OF THE INVENTION
Embodiments of the present invention include an apparatus having an improved, tunable gamma response. The apparatus comprises a light modulator having a plurality of spaced-apart elements, having alternating active elements and passive elements lying in a first plane; a gamma controller; and a displacement controller. The gamma controller applies a gamma voltage to a substrate, creating an electro-static field that pulls the spaced-apart elements to a bias plane parallel to the first plane and preferably closer to the substrate. In a reflection mode, the plurality of spaced-apart elements all lie in the bias plane, and a light beam impinging on the plurality of spaced-apart elements will be substantially reflected so that the plurality of spaced-apart elements act as a specular mirror. A low-noise optical receiver that accepts only diffracted light (a first-order receiver) will detect a signal having a substantially zero illumination intensity. In a diffraction mode, the displacement controller applies a displacement voltage to the active elements. In response to the displacement controller, the active elements are moved to a second plane substantially parallel to the bias plane and preferably closer to the substrate so that a light beam impinging on the light modulator will be substantially diffracted. A first-order receiver will now detect a signal having a non-zero illumination intensity. The illumination intensity of the detected signal is proportional to the displacement voltage raised to an exponential power known as the gamma response. Preferably, the gamma response is between approximately 1.75 and 3.0.
REFERENCES:
patent: 1525550 (1925-02-01), Jenkins
patent: 1548262 (1925-08-01), Freedman
patent: 1814701 (1931-07-01), Ives
patent: 2415226 (1947-02-01), Sziklai
patent: 2783406 (1957-02-01), Vanderhooft
patent: 2920529 (1960-01-01), Blythe
patent: 2991490 (1961-07-01), Grey et al.
patent: 3256565 (1966-06-01), Weissenstern et al.
patent: 3388301 (1968-06-01), James
patent: 3443871 (1969-05-01), Chitayat
patent: 3553364 (1971-01-01), Lee
patent: 3576394 (1971-04-01), Lee
patent: 3600798 (1971-08-01), Lee
patent: 3656837 (1972-04-01), Sandbank
patent: 3657610 (1972-04-01), Yamamoto et al.
patent: 3693239 (1972-09-01), Dix
patent: 3743507 (1973-07-01), Ih et al.
patent: 3752563 (1973-08-01), Torok et al.
patent: 3781465 (1973-12-01), Ernstoff et al.
patent: 3783184 (1974-01-01), Ernstoff et al.
patent: 3792916 (1974-02-01), Sarna
patent: 3802769 (1974-04-01), Rotz et al.
patent: 3811186 (1974-05-01), Larnerd et al.
patent: 3861784 (1975-01-01), Torok
patent: 3862360 (1975-01-01), Dill et al.
patent: 3871014 (1975-03-01), King et al.
patent: 3886310 (1975-05-01), Guldberg et al.
patent: 3896338 (1975-09-01), Nathanson et al.
patent: 3915548 (1975-10-01), Opittek
patent: 3935499 (1976-01-01), Oess
patent: 3935500 (1976-01-01), Oess et al.
patent: 3938881 (1976-02-01), Biegelsen et al.
patent: 3941456 (1976-03-01), Schilz et al.
patent: 3942245 (1976-03-01), Jackson et al.
patent: 3943281 (1976-03-01), Keller et al.
patent: 3947105 (1976-03-01), Smith
patent: 3969611 (1976-07-01), Fonteneau
patent: 3980476 (1976-09-01), Wysocki
patent: 3991416 (1976-11-01), Byles et al.
patent: 4001663 (1977-01-01), Bray
patent: 4004849 (1977-01-01), Shattuck
patent: 4006968 (1977-02-01), Ernstoff et al.
patent: 4009939 (1977-03-01), Okano
patent: 4011009 (1977-03-01), Lama et al.
patent: 4012116 (1977-03-01), Yevick
patent: 4012835 (1977-03-01), Wallick
patent: 4017158 (1977-04-01), Booth
patent: 4020381 (1977-04-01), Oess et al.
patent: 4021766 (1977-05-01), Aine
patent: 4034211 (1977-07-01), Horst et al.
patent: 4034399 (1977-07-01), Drukier et al.
patent: 4035068 (1977-07-01), Rawson
patent: 4067129 (1978-01-01), Abramson et al.
patent: 4084437 (1978-04-01), Finnegan
patent: 4090219 (1978-05-01), Ernstoff et al.
patent: 4093346 (1978-06-01), Nishino et al.
patent: 4093921 (1978-06-01), Buss
patent: 4093922 (1978-06-01), Buss
patent: 4100579 (1978-07-01), Ernstoff
patent: 4103273 (1978-07-01), Keller
patent: 4126380 (1978-11-01), Borm
patent: 4127322 (1978-11-01), Jacobson et al.
patent: 4135502 (1979-01-01), Peck
patent: 4139257 (1979-02-01), Matsumoto
patent: 4143943 (1979-03-01), Rawson
patent: 4163570 (1979-08-01), Greenaway
patent: 4184700 (1980-01-01), Greenaway
patent: 4185891 (1980-01-01), Kaestner
patent: 4190855 (1980-02-01), Inoue
patent: 4195915 (1980-04-01), Lichty et al.
patent: 4205428 (1980-06-01), Ernstoff et al.
patent: 4211918 (1980-07-01), Nyfeler et al.
patent: 4223050 (1980-09-01), Nyfeler et al.
patent: 4225913 (1980-09-01), Bray
patent: 4249796 (1981-02-01), Sincerbox et al.
patent: 4250217 (1981-02-01), Greenaway
patent: 4250393 (1981-02-01), Greenaway
patent: 4256787 (1981-03-01), Shaver et al.
patent: 4257016 (1981-03-01), Kramer, Jr. et al.
patent: 4290672 (1981-09-01), Whitefield
patent: 4295145 (1981-10-01), Latta
patent: 4311999 (1982-01-01), Upton et al.
patent: 4327411 (1982-04-01), Turner
patent: 4327966 (1982-05-01), Bloom
patent: 4331972 (1982-05-01), Rajchman
patent: 4336982 (1982-06-01), Rector, Jr.
patent: 4338660 (1982-07-01), Kelley et al.
patent: 4343535 (1982-08-01), Bleha, Jr.
patent: 4346965 (1982-08-01), Spraque et al.
patent: 4348079 (1982-09-01), Johnson
patent: 4355463 (1982-10-01), Burns
patent: 4361384 (1982-11-01), Bosserman
patent: 4369524 (1983-01-01), Rawson et al.
patent: 4374397 (1983-02-01), Mir
patent: 4389096 (1983-06-01), Hori et al.
patent: 4391490 (1983-07-01), Hartke
patent: 4396246 (1983-08-01), Holman
patent: 4398798 (1983-08-01), Krawczak et al.
patent: 4400740 (1983-08-01), Traino et al.
patent: 4408884 (1983-10-01), Kleinknecht et al.
patent: 4414583 (1983-11-01), Hooker, III
patent: 4417386 (1983-11-01), Exner
patent: 4418397 (1983-11-01), Brantingham et al.
patent: 4420717 (1983-12-01), Wallace et al.
patent: 4422099 (1983-12-01), Wolfe
patent: 4426768 (1984-01-01), Black et al.
patent: 4430584 (1984-02-01), Someshwar et al.
patent: 4435041 (1984-03-01), Torok et al.
patent: 4440839 (1984-04-01), Mottier
patent: 4443819 (1984-04-01), Funada et al.
patent: 4443845 (1984-04-01), Hamilton et al.
patent: 4447881 (1984-05-01), Brantingham et al.
patent: 4454591 (1984-06-01), Lou
patent: 4456338 (1984-06-01), Gelbart
patent: 4460907 (1984-07-01), Nelson
patent: 4462046 (1984-07-01), Spight
patent: 4467342 (1984-08-01), Tower
patent: 4468725 (1984-08-01), Venturini
patent: 4483596 (198
Dinh Jack
Epps Georgia
Haverstock & Owens LLP
Silicon Light Machines
LandOfFree
Method and device for modulating a light beam and having an... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and device for modulating a light beam and having an..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and device for modulating a light beam and having an... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3276128