Scott J Cameron

US Patent:

20130290421, Oct 31, 2013

Filed:

Apr 18, 2013

Appl. No.:

13/865886

Inventors:

James LAMANNA - Los Angeles CA, US
Braddock GASKILL - South Pasadena CA, US
David DOUGLAS - Concord MA, US
Scott CAMERON - Pasadena CA, US

Assignee:

TouchTable, Inc. - Pasadena CA

International Classification:

G06F 15/163

US Classification:

709204

Abstract:

Visualization of relatively complex data sets and the simultaneous synchronization of such data sets across both a network and to different areas having different capabilities is disclosed, especially in connection with session structure, synchronization, synchronized control of imagery, and restoring synchronization to a predefined tour.

US Patent:

60940263, Jul 25, 2000

Filed:

Feb 2, 1994

Appl. No.:

8/191060

Inventors:

Scott W. Cameron - Milpitas CA

Assignee:

STMicroelectronics, Inc. - Carrollton TX

International Classification:

H02P 104

US Classification:

318471

Abstract:

A method and integrated circuit for providing drive signals to a polyphase dc motor. The integrated circuit is fabricated on a semiconductor substrate for providing drive signals to a polyphase dc motor. The circuit includes a coil drive circuit for connection to drive coils of the motor to selectively supply drive currents thereto in a predetermined sequence. A sequencer circuit commutatively selects the drive coils to which the drive currents are selectively supplied, and a motor, speed controlling circuit controls the speed of the motor by controlling the speed of commutation. A temperature sensing element, such as a diode, is fabricated in the substrate to indicate the temperature of the substrate, and a temperature measuring circuit is connected to the temperature sensing element and to the motor speed controlling circuit to operate the motor speed controlling circuit to slow the speed of the motor when the temperature of the substrate exceeds a first predetermined temperature. If desired, temperature measuring circuit can include a circuit for measuring a second temperature higher than the first predetermined temperature to operate a shut down circuit to turn off the motor if the substrate temperature is too high.

US Patent:

55460305, Aug 13, 1996

Filed:

Dec 30, 1994

Appl. No.:

8/366793

Inventors:

Scott W. Cameron - Milpitas CA

Assignee:

SGS-Thomson Microelectronics, Inc. - Carrollton TX

International Classification:

H03K 300
H03L 500
G06G 712
G11B 509

US Classification:

327110

Abstract:

An innovative circuit for driving the write head. All of the driving transistors are NPN, and are prevented from saturation. This is achieved by shifting and scaling down the differential drive applied to the pull-up transistors, to drive the pull-down transistors with levels such that the pull-down transistors cannot reach saturation. This provides a very simple circuit in which all four of the drive transistors are NPN, and all are kept out of saturation. Moreover, the peak write current applied to the head is precisely limited.

US Patent:

57709688, Jun 23, 1998

Filed:

Dec 30, 1994

Appl. No.:

8/366790

Inventors:

Scott Warren Cameron - Milpitas CA

Assignee:

SGS-Thomson Microelectronics, Inc. - Carrollton TX

International Classification:

G11B 502
H03F 345

US Classification:

327538

Abstract:

An innovative differential amplifier circuit, which can control the midpoint potential of a load which does not itself have any midpoint connection. This is achieved by using a proxy load element in parallel with the primary load. The proxy load is of much higher impedance value than the primary load, and does have a center tap. The potential of the center tap of the mirrored load is used for a feedback connection to a control loop which regulates the output to both the primary load and the proxy load.

US Patent:

6172548, Jan 9, 2001

Filed:

Dec 30, 1994

Appl. No.:

8/366561

Inventors:

Scott Warren Cameron - Milpitas CA
Axel Alegre de La Soujeole - Scotts Valley CA

Assignee:

STMicroelectronics, Inc. - Carrollton TX

International Classification:

H03L 500

US Classification:

327309

Abstract:

The present application discloses an innovative improved circuit, in which the long transient at write-to-read transitions is avoided by using a shorting switch to short the inputs of the first amplifier stage together when the read amplifier is activated. This speeds up write-to-read transition. Moreover, since read mode can now be entered more quickly after a power-down condition, this circuit also permits the use of other power-saving tricks to idle the read amplifier momentarily.

US Patent:

55571808, Sep 17, 1996

Filed:

Jun 30, 1993

Appl. No.:

8/085507

Inventors:

Scott W. Cameron - Milpitas CA

Assignee:

SGS-Thomson Microelectronics, Inc. - Carrollton TX

International Classification:

H02P 118

US Classification:

318254

Abstract:

A circuit and method for operating a polyphase dc motor of the type having a plurality of driving coils connected together at a center tap current input node. Each driving coil have a current input node at an end opposite the center tap connection. A plurality of pairs of switches are arranged for connection in series across a power supply voltage. Each pair have a connection node between each switch connected to a respective one of the current input nodes. A sequencer individually operates the switches to cause a driving current to be passed between sequentially selected only single ones of the driving coils and the center tap current input node.

US Patent:

54558859, Oct 3, 1995

Filed:

Feb 13, 1995

Appl. No.:

8/387386

Inventors:

Scott W. Cameron - Milpitas CA

Assignee:

SGS-Thomson Microelectronics, Inc. - Carrollton TX

International Classification:

H02P 7285

US Classification:

388834

Abstract:

A method and apparatus for operating a polyphase dc motor selectively in dual-coil or uni-coil commutation modes. The motor has a plurality of "Y" connected driving coils connected together at a center tap. Each driving coil has an input node at an end opposite the center tap, and is driven by a switch pair. Each switch pair is arranged for connection in series across a power supply voltage, and has a node between each switch connected to a respective one of the coil input nodes. An additional pair of switches are provided for connection in series across the power supply with a connection node between each switch connected to the center tap. A circuit is provided to operate the switches to cause a driving current to be passed between sequentially selected pairs of the driving coils for an initial start-up time. Also, a circuit to operate the switches after the initial start-up time is provided to cause a driving current to be passed between sequentially selected only single ones of the driving coils and the center tap current input node. The apparatus also has a circuit for detecting a zero crossing of a bemf signal of a floating one of the driving coils and a delay circuit for establishing a delay between a zero crossing and a commutation of driving signals to the coils.

US Patent:

56191090, Apr 8, 1997

Filed:

Jun 7, 1995

Appl. No.:

8/477458

Inventors:

Scott W. Cameron - Milpitas CA
Karl M. Schlager - Campbell CA

Assignee:

SGS-Thomson Microelectronics, Inc. - Carrollton TX

International Classification:

H02P 310

US Classification:

318375

Abstract:

A method and circuit for braking a forward rotation of a rotor of a polyphase DC motor. A commutation sequencer is incremented by several phases to produce an incremented commutation sequence to produce a magnetic flux vector that lags a magnetic pole of the motor. Driving currents are applied to coils of the motor in accordance with the incremented commutation sequence to brake the rotor. The method is implemented in a circuit that has a sequencer for incrementally generating sets of commutation signals to select stator coils for energization to rotate the rotor. A power stage to which the commutation signals are applied energizes the selected coils in accordance with the commutation signals. A circuit interrupts the energization of the selected coils and the commutation sequence is altered to produce a sequence that produces a negative torque on the rotor. Circuits are also provided to inhibit application of the altered commutation sequence until recirculation currents in the power stage caused by the coils in response to the reduction of the input voltage have fallen below a predetermined level, and to inhibit application of the altered commutation sequence until a voltage on a sense resistor between the power stage and a reference potential has fallen below a predetermined level after an operation of the circuit for interrupting the energization of the selected coils.