Abstract: A driver circuit for driving top and bottom power transistors stacked between two supply terminals is provided. The driver circuit includes shoot-through reduction means for monitoring the gate-to-source voltages of the two power transistors so as to inhibit the turning-ON of each power transistor until the gate-to-source voltage of the other power transistor has fallen to a voltage level indicative of the other transistor being OFF. Additionally, the driver circuit which can utilize a bootstrap capacitor for providing enhanced voltages to drive the top power transistor, also includes a bootstrap capacitor recharge means to monitor the output voltage of the circuit so as to inhibit the turning-ON of the top power transistor until the bootstrap capacitor has had sufficient time to recharge.
Abstract: A three terminal control circuit for a low dropout voltage regulator having a PNP pass transistor is provided. The control circuit is capable of pulling the base drive point down to a voltage of 3.0 volts or less to permit a current limiting resistor to be inserted between the base drive point and the base of the PNP pass transistor. The control circuit includes a pair of small-valued capacitors for providing stable operation with different output capacitors. The control circuit can also be used with p-channel FET pass transistors.
Type:
Grant
Filed:
July 27, 1993
Date of Patent:
August 2, 1994
Assignee:
Linear Technology Corporation
Inventors:
Robert C. Dobkin, Carl T. Nelson, Dennis P. O'Neill
Abstract: A method and apparatus for displaying an image that is subject to multiple distortions substantially without distortion is provided. The image is recorded from a first viewpoint and subject to a first distortion and played back from a second viewpoint and subject to a second distortion. The display surface may also be distorted (e.g., curved). By mapping back through the projector to the screen and through the camera (at the viewpoint), the image is transformed so that it can be viewed from the viewpoint with little or no distortion.
Type:
Grant
Filed:
June 30, 1992
Date of Patent:
July 12, 1994
Assignee:
The Walt Disney Company
Inventors:
Gordon E. Liljegren, William G. Redmann, Scott F. Watson
Abstract: A method and circuit for increasing the output impedance of an inactive amplifier is provided. The method and circuit allows an increased number of amplifiers to be coupled in parallel to a single transmission line for distributing a plurality of video or other electrical signals to a remote location. The method and circuit increasing the impedance of an amplifier feedback network during inactive operation using a bootstrapping technique (i.e., by driving the feedback network) so as to increase the overall impedance of the amplifier during such operation.
Abstract: A blank book attachment having a mark and sweep leaf with a fold out feature is provided. The leaf is pivotally retained along one edge on a frame, and the frame is pivotally retained at the binding spine of the host blank book. Pulling outward on the leaf causes the leaf to extend out and beyond the pages of the book allowing the pages to turn freely. When the leaf is placed within the host book, with the book open or closed, the leaf can be turned as a page, in which case it also acts as a mark to identify a specific position in the host book. Alternatively, the leaf may be pivoted on the frame to allow the host book pages to be turned past it in either direction.
Abstract: A power efficient circuit for charging the gate of a transistor switch to a charge-pumped voltage level in excess of a supply rail voltage is provided. The circuit includes a current-controlled oscillator which generates an oscillating waveform that drives a capacitive charge-pump circuit. The circuit monitors the gate voltage of the transistor switch and reduces the frequency of the oscillating waveform, thereby reducing power consumption, when the gate voltage exceeds a frequency switching value indicating that the transistor switch has been sufficiently turned so as to allow the circuit to enter a micropower mode.
Abstract: A differential input amplifier stage having improved frequency compensation. Frequency compensation is achieved by cancelling one-half of the signal output of a differential error amplifier in the input stage, such that all error signals must pass through a "current-mirror" type load circuit in which a resistor-capacitor network is provided to roll off gain of the input stage.
Abstract: A graphic interface configuration system is allows a user to create a graphic interface for a computer program in which graphic elements in the interface are linked to variables or functions in any one of a number of programming elements.
Abstract: A graphic user interface for a computer is provided in which representations of application programs can be placed on the display in a specified area reserved for such a purpose in which area they could not be so readily obscured and forgotten, and which includes a facility for controlling the placement of such representations within the reserved area. The graphic images are guided into specific locations, or "docks" in the reserved area, and their removal from the docks is restricted to prevent accidental withdrawal.
Type:
Grant
Filed:
February 27, 1991
Date of Patent:
September 8, 1992
Assignee:
NeXT Computer, Inc.
Inventors:
Jean-Marie Hullot, Steven P. Jobs, Christopher M. Franklin
Abstract: A rectangular array signed digit multiplier circuit (10) is disclosed which comprises a multiplier core (28). The circuit (10) comprises a C-latch (14), a D-latch (18), an A-latch (26), and a feedback latch (52) operable to store operands to be input into the multiplier core (28) through a MULTIPLIER INPUT, a multiplicand INPUT, and ADDER INPUT and a FEEDBACK INPUT, respectively, The product output by the multiplier core (28) may comprise the sum of the product of the values input through the MULTIPLIER INPUT and MULTIPLICAND INPUT and the ADDER and FEEDBACK INPUTS. The product is stored in a result latch (40) and may be used in subsequent passes through multiplier core (28) through the use of a data path coupling result latch (40) with feedback latch (52). Multiplier core (28) comprises a series connection of a times three adder level (56), a Booth recoder level (58), a partial product generator level (60), a level one adder level (62), a level two adder level (64) and a level three adder level (66).
Abstract: A blank book attachment having a mark and sweep leaf with a fold out feature is provided. The leaf is pivotably retained along one edge on a frame, and the frame is pivotably retained at the binding spine of the host blank book. Pulling outward on the leaf causes the leaf to extend out and beyond the pages of the book allowing the pages to turn freely. When the leaf is placed within the host book, with the book open or closed, the leaf can be turned as a page, in which case it also acts as a mark to identify a specific position in the host book. Alternatively, the leaf may be pivoted on the frame to allow the host book pages to be turned past it in either direction.
Abstract: A method and apparatus for performing graphic compositing operations in a computer system, with improved system performance, is provided. The apparatus and method performs the plurality of compositing operations by implementing a series of write functions, selected from a group of write functions, in a predetermined combination or order.
Type:
Grant
Filed:
October 11, 1988
Date of Patent:
January 1, 1991
Assignee:
NeXT, Inc.
Inventors:
Leonard J. Hourvitz, John K. Newlin, Richard A. Page