Predistorter for high frequency optical communications devices
Granted: June 13, 1995
Patent Number:
5424680
A generalized frequency dependent predistortion circuit for nonlinear optic devices such as semiconductor lasers and light emitting diodes includes a pre-filter and post-filter associated with a linearizer (distorter). A multi-channel sub-carrier electrical signal is input to a splitter which provides on a primary path a signal to a time delay and hence to a coupler to the secondary paths. In the first secondary path, a pre-filter provides a signal to a second order distorter. This…
Head rail-mounted mini-blind actuator
Granted: February 21, 1995
Patent Number:
5391967
A mini-blind actuator has a motor and a housing that holds the motor and a dc battery. The rotor of the motor is coupled to the baton of the mini-blind for rotating the baton and thereby opening or closing the slats of the mini-blind. Alternatively, the rotor is coupled to the tilt rod of the blind to rotate the tilt rod and thereby open or close the slats of the mini-blind. A control signal generator generates a control signal for completing the electrical circuit between the battery…
Positioning actuator
Granted: December 6, 1994
Patent Number:
5370011
The present disclosure concerns an actuator for converting rotary movement into linear movement. The actuator comprises a prime mover turning a reduction gear assembly which, in turn, drives a mechanical transmission including a linearly moving control element. To achieve precise movement of the control element to a desired position, and to ensure the desired position is retained as exactly as possible, a reduction gear assembly which is self-locking with respect to the maximum…
Electromagnetic motor of the finite rotational type
Granted: November 29, 1994
Patent Number:
5369322
An electromagnetic motor of the finite rotational type has an improved rotor-returning mechanism for exerting a magnetic force to return its rotor to the initial angular position in a non-excited condition. The rotor-returning mechanism is comprised of a permanent magnet fixedly mounted on a stator and a permanent magnet mounted around the rotor. The permanent magnets are arranged such that, a magnetic attractive force generated between the permanent magnets functions to return the rotor…
Positioning device for a member and drilling system employing said positioning device
Granted: October 11, 1994
Patent Number:
5353884
The present invention relates to a positioning device capable of positioning a member in any direction with a high degree of resolution by using a hollow type harmonic drive mechanism, and to a drilling-direction control device for a drilling system utilizing the positioning device. The device of the present invention is mainly constituted by a double eccentric mechanism section (10). A first annular member (12) is rotatably supported by a circular inner circumferential surface (11a) of…
Attitude control device and drilling-direction control device
Granted: May 31, 1994
Patent Number:
5316090
An attitude control device has a plurality of harmonic drive mechanisms of the hollow type, preferably first and second harmonic drive mechanisms. First and second rotational members are connected to the outputs of the first and second harmonic drive mechanisms. These rotational members have eccentric hollow portions which rotate eccentrically around the rotational axes of the harmonic drive mechanisms. A member to be driven is placed to extend through the eccentric hollow portions such…
Attitude and drilling-direction control device
Granted: May 3, 1994
Patent Number:
5307885
An attitude control device has a plurality of harmonic drive mechanisms of the hollow type, preferably first and second harmonic drive mechanisms. First and second rotational members are connected to the outputs of the first and second harmonic drive mechanisms. These rotational members have eccentric hollow portions which rotate eccentrically around the rotational axes of the harmonic drive mechanisms. A member to be driven is placed to extend through the eccentric hollow portions such…
Structure for uniting shapes and images with words
Granted: April 26, 1994
Patent Number:
5306006
Methods of making a predetermined shape from a plurality of uniformly styled letters of a word comprise the steps of measuring each letter in the word to determine how much of a total shape area each letter will occupy; placing a first letter along an outer edge of the predetermined shape; adjusting another letter of the word so that it can be placed against at least one of an edge of the first letter and the outer edge of the predetermined shape; placing the another letter; and…
Planetary gear transmission
Granted: March 22, 1994
Patent Number:
5295925
A two-stage planetary gear transmission having a first-stage planetary gear transmission and a second-stage planetary gear transmission is disclosed, wherein the carrier of the second-stage planetary gear transmission comprises first and second carrier parts integrally connected with each other. A hollow pinion shaft formed thereon with the sun gear of the second stage is rotationally supported on the first carrier part via a deep-channel ball bearing in a cantilevered condition. A…
Wave gear drive
Granted: February 1, 1994
Patent Number:
5282398
A wave gear drive having a wave generator whose exterior configuration is formed using a shape defined by a tangential polar coordinate equation having at least four Fourier expansion terms, whereby the amount of flexing of the flexible external gear can be maintained at a prescribed magnitude while simultaneously reducing the magnitude of the tooth rim bending stress of the external gear, and the meshing entry gap of the teeth can be enlarged, thus eliminating the danger of tooth…
Shunt-expansive predistortion linearizers for optical analog transmitters
Granted: January 25, 1994
Patent Number:
5282072
This invention teaches new types of linearization circuits, exhibiting improved broadband suppression of nonlinear distortion. These realizations do not require the use of reactive elements such as capacitors, or of active elements such as transistors, eliminating the drawbacks of prior art realizations. The linearization circuits are particularly suitable for linearizing optical sources with odd wave voltage to light transfer characteristics, such as externally modulated CW lasers. The…
Cascaded optical modulation system with high linearity
Granted: January 11, 1994
Patent Number:
5278923
An optical modulation system having cascade-coupled electro-optic modulator stages in either dual tandem or split tandem configurations. An electrical splitter derives multiple electrical drives for the multiple stages from a single modulating input signal. The multiple drive signals are linearly related in magnitude and preferably induce simultaneous antiphase (180.degree. out-of-phase) optical modulation in the tandem stages. While a double Mach-Zehnder cascade configuration could be…
Cup-type harmonic drive having a short, flexible cup member
Granted: December 14, 1993
Patent Number:
5269202
A cup-type harmonic gear drive comprises a rigid circular spline, a cup-shaped flexspline disposed inside the circular spline and a wave generator means fitted inside the flexspline for flexing the flexspline into elliptic to engage it with the circular spline and for rotating the engagement portions to thereby produce relative rotation between the splines. The flexspline has a tube, a disc-shaped diaphragm connected integrally to the end of said tube to define the cup bottom, and a…
Optical distribution of analog and digital signals using optical modulators with complementary outputs
Granted: October 12, 1993
Patent Number:
5253309
A novel optical system is taught including an optical source, an optical modulator having at least one optical input port for receiving the optical signal from the optical source, a modulation port for receiving the optical signal from the optical source, a modulation port for receiving a modulating signal, and complementary output port signals. The complementary modulated output signals are applied to one or more optical receivers at the other end of an optical transmission link. In one…
Active alignment system for laser to fiber coupling
Granted: June 1, 1993
Patent Number:
5216729
A laser generates a beam which is actively steered into an optical element having a waveguide which receives and transmits the beam. The waveguide is coupled to an optical fiber which is also actively steered. Both the beam steering and fiber steering mechanisms seek to align the beam from the laser to the fiber for maximum output. The beam steering mechanism features a pair of planar mirrors pivoted at right angles to each other. A precision force transducer will cause desired amounts…
Temperature stable solid-state laser package
Granted: January 19, 1993
Patent Number:
5181214
A laser-diode or laser diode array end-pumped solid-state laser package for optical communications and the like mounted on a common thermally conductive, low thermal expansion base that is temperature stabilized with a thermo-electric cooler. The laser package includes a heat sink, a thermo-electric cooler mounted on the heat sink, a base having a base plate portion mounted on the thermo-electric cooler and a block portion mounted on the base plate portion and optical elements mounted on…
Unidirectional, planar ring laser with birefringence
Granted: January 5, 1993
Patent Number:
5177764
The present invention provides a means of inducing unidirectional oscillation in monolithic and composite ring lasers in which the light path is planar. The intracavity optical diode that enforces unidirectional oscillation in the planar ring oscillator is achieved by a combination of the nonreciprocal Faraday effect, a linear birefringence effect in which the principal axes of the birefringence are not parallel and perpendicular to the plane of propagation of the ring light path, and…
Optical transmitters linearized by means of parametric feedback
Granted: November 3, 1992
Patent Number:
5161044
The invention discloses a general technique of taking advantage of the stability of the modulator transfer characteristic in order to correct for second and third order distortion. These objectives are achieved in a way compatible with the nature of the video distribution frequency formats. The method of this invention for linearizing the amplitude transfer characteristic of integrated optic devices for analog transmission is accomplished by injecting pilot signals, monitoring the…
Tunable single-frequency ring laser
Granted: September 15, 1992
Patent Number:
5148444
A tunable, single-frequency, solid-state ring laser includes a solid-state laser material pumped by laser-diode light and at least one additional external piece which reflects the intra-cavity lasing light in a closed loop such that the plane of polarization is changed in an appropriate amount to compensate for magneto-optic change (Faraday rotation) of the plane of polarization, which occurs either inside the solid-state material or in one of the external pieces which traversed by the…
Light wave polarization determination using a hybrid system
Granted: April 7, 1992
Patent Number:
5102222
Apparatus and method for determining dynamically the polarization vector direction, or polarization vector components and associated temporal phase angle, of a light beam. The apparatus includes a compact polarization beam splitter that receives a beam of light, separates the beam into two perpendicular polarization components and directs these components to a pair of optical detectors and associated circuits that form the sum and difference signals of the electrical signals produced by…
