Semiconductor device manufacturing: process – Making device or circuit responsive to nonelectrical signal
Reexamination Certificate
1998-08-28
2001-04-10
Nelms, David (Department: 2818)
Semiconductor device manufacturing: process
Making device or circuit responsive to nonelectrical signal
C355S053000, C355S067000
Reexamination Certificate
active
06214633
ABSTRACT:
FIELD OF THE INVENTION
The present invention is directed to providing intensity modulation using micromachine technology. In particular, intensity modulation is accomplished by at least one microscopic shutter. The shutters are fabricated using lithographic micromachining techniques. The shutters are incorporated into a system for controlling light, each shutter being located at the focal point of a microlens array used to deliver light to, and direct light from, a focal plane of the array.
BACKGROUND OF THE INVENTION
Conventionally, intensity modulation devices included liquid crystals and tiltable mirrors. Such intensity modulators have disadvantages in that light throughput efficiency and light power handling capacity are insufficient and stray light noise is too high. In particular, the liquid crystal display suffers most greatly regarding the light throughput efficiency and light power handling capacity, while the tilting micromirrors suffer from stray light noise.
In addition, although conventional intensity modulation devices such as liquid crystals are well-suited for large applications, they are not particularly well-suited for regulating the intensity of light on a microscopic scale. Rather, their large size renders them incapable of efficiently operating to block incident light in applications requiring fine precision intensity regulation on a small scale.
In the absence of a device capable of regulating the intensity of light on a microscopic scale, microscopic devices requiring such light regulation have generally relied upon pulsed laser light. Similarly, to digitalize conventional devices that are optically driven without increasing the size of those devices, pulsed laser light has been relied upon. For instance, when printing devices are digitalized, laser diodes have been conventionally used to regulate laser beams incident upon special paper where images are to be formed.
However, disadvantages frequently result when laser beams are required. For instance, when digitalizing printing devices as described above, an expensive type of special paper is required for printing and power consumption of the printing device must be increased to generate laser beams.
SUMMARY OF THE INVENTION
It is an object of the present invention to overcome all of the disadvantages noted above. In particular, the present invention may overcome these problems by using a true shutter. In other words, when the shutter in accordance with the present invention is open, 100% of the light is through put efficiently. When closed, all of the light is blocked, and not redirected as in the mirror systems.
Other and further objects, features and advantages of the present invention will be set forth in the description that follows, and in part will become apparent from the detailed description, or may be learned by practice of the invention.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, the present invention includes an apparatus for controlling light comprising a non-transparent surface for blocking incident light, an array of first lenses for focusing the incident light upon the non-transparent surface, an array of shutters corresponding to the array of first lenses and positioned on the non-transparent surface for controlling passage of the incident light through the non-transparent surface, and an array of second lenses corresponding to the array of shutters for collimating the incident light passing through the shutters. In this apparatus, the shutters are separated from the first lenses by a distance equal to a focal distance of the first lenses such that the incident light is focused by the first lenses onto the shutters. As such, the shutters may be opened and closed to control the intensity of the incident light passing therethrough.
The apparatus may further comprise electrostatic comb drives corresponding to the array of shutters for actuating the shutters, where the electrostatic comb drives each include two stationary stators that are separated by a distance at least as great as the largest shutter openings, and the shutter include two sliders that move relative to the stationary stators based on a magnitude of a voltage applied thereto. Alternatively, the apparatus may include return springs for biasing the shutters in an opened or closed position, and micromachine actuators for controlling actuation of the shutters. In either case, the shutters may be Foucault shutters, or other known shutters.
In addition, the present invention includes a method of manufacturing a micromachine Foucault shutter array that includes assembling an array of shutters on a non-transparent surface for controlling passage of incident light through the non-transparent surface, assembling an array of first lenses corresponding to the array of shutters for focusing incident light upon the non-transparent surface, positioning the array of first lenses relative to the non-transparent surface such that the incident light is focused upon the shutters by the first lenses, and assembling an array of second lenses corresponding to the array of shutter for collimating the incident light passing through the shutters. Electrostatic comb drives and/or micromachine actuators may be installed to control actuation of the shutters, thereby opening and closing the shutters to control the intensity of incident light passing therethrough. Electrostatic comb drives include two stationary stators that are separated by a distance at least as great as the largest possible opening in the shutters, where the shutters each include two sliders that move relative to the stationary stators based on a magnitude of a relative voltage applied thereto. Return springs may also be installed for biasing the shutter in an opened or closed position.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in this art from this detailed description.
REFERENCES:
patent: 4212519 (1980-07-01), Drexhage et al.
patent: 4584056 (1986-04-01), Perret et al.
patent: 4755415 (1988-07-01), Iijima et al.
patent: 4854678 (1989-08-01), Kitano et al.
patent: 4887104 (1989-12-01), Kitano et al.
patent: 5629918 (1997-05-01), Ho et al.
patent: 5675402 (1997-10-01), Cho et al.
Clark Rodney L.
Karpinsky John R.
Le Dung
Mems Optical Inc.
Nelms David
LandOfFree
System for controlling light including a micromachined... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with System for controlling light including a micromachined..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and System for controlling light including a micromachined... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2463318