Abstract: A lens has a body (1), reinforcing extensions (3a, 3b) and a clear aperture (9) surrounded on top and bottom by lens body. The lens is suitable for spot scanning. The lens is made of a water absorbing material, such as most polymers, particularly acrylate polymers. Aluminum sheets as vapor barriers are attached on each side of the lens body. This results in excellent resistance to change or distortion in high humidity environments.
Type:
Grant
Filed:
January 16, 2003
Date of Patent:
October 19, 2004
Assignee:
Lexmark International, Inc.
Inventors:
Roger Steven Cannon, Dana Allen Dodds, Philip Jerome Heink, Robert LeRoy Paterson, Daniel Eugene Pawley, Wilson Morgan Routt, Jr.
Abstract: This application discloses circuit and method for reducing the turn-off time of a power transistor driving an inductive load. The circuit clamps the gate to source of a power transistor by using two field effect transistors as the current path across the gate and source of the power transistor. A zener diode connected from the source to gate of the two field effect transistors is used to provide high voltage protection.
Abstract: A chopper stabilized current amplifier circuit is disclosed. The current amplifier circuit includes a main operational transconductance amplifier, a nulling transconductance amplifier, two capacitors, four switches, and a timing control circuit. The timing control circuit uses analog inverters to decrease the slew rate of the switching of the switches to decrease the noise in the system.
Abstract: A digital-to-analog converter has a bias block that provides first and second voltage outputs, and a bit cell having a switch for selectively connecting either a first or a second summing node to a current flow path depending upon the state of a binary input signal. An output bipolar transistor and a current source are connected in series between a supply voltage and a reference potential. A first MOS transistor is connected in the current flow path with its gate connected to the bipolar transistor. A base current compensating second MOS transistor is connected between the supply voltage and a base of the output bipolar transistor with its gate connected to the first voltage output of the amplifier. A resistor is connected between the base of the output bipolar transistor and the second voltage output of the amplifier. When a plurality of bit stages are provided, the resistor of each of the plurality of bit cells is sized according to a position of its associated cell in the bit order.
Abstract: A circuit for providing drive current to a coil of a motor uses a sensefet current sensing device having a sense node and a source node. The source node is connected to deliver current to the coil, wherein a "sense" current proportional to said delivered current is produced on the sense node. An amplifier is connected to sense a voltage between said sense and source nodes to produce an output voltage to force a voltage on the sense node to be the same as a voltage on the source node. A pass element is connected to route said "sense" current to an output node. The circuit produces an output that is suitable for use as a feedback signal in a motor control system.