David L Ludwig

Author:

David Ludwig

ISBN #:

0618683267

Author:

David Ludwig

ISBN #:

0806619198

Author:

David Ludwig

ISBN #:

0844223859

Author:

David Ludwig

ISBN #:

0894648772

Author:

David J. Ludwig

ISBN #:

0570045274

Author:

David J. Ludwig

ISBN #:

0806617217

Author:

David J. Ludwig

ISBN #:

0789011964

Author:

David J. Ludwig

ISBN #:

0789011972

US Patent:

7180579, Feb 20, 2007

Filed:

Mar 22, 2004

Appl. No.:

10/806037

Inventors:

David E. Ludwig - Irvine CA, US
John V. Kennedy - Irvine CA, US
William Kleinhans - Westlake Village CA, US
Tina Liu - Westlake Village CA, US
Christian Krutzik - Costa Mesa CA, US

Assignee:

Irvine Sensors Corp. - Costa Mesa CA

International Classification:

G01C 3/08

US Classification:

356 401, 356 501, 356 502, 356 402

Abstract:

A 3-D LADAR imaging system incorporating stacked microelectronic layers is provided. A light source is imaged upon a target through beam shaping optics. Photons reflected from the target are collected and imaged upon a detector array though collection optics. The detector array signals are fed into a multilayer processing module wherein each layer includes detector signal processing circuitry. The detector array signals are amplified, compared to a user-defined threshold, digitized and fed into a high speed FIFO range bin. Dependant on the value of the digit contained in the bins in the register, and the digit's bin location, the time of a photon reflection from a target surface can be determined. A Ttrigger signal defines the reflection time represented by each bin location by resetting appropriate circuitry to begin processing. The bin data representing the photon reflections from the various target surfaces are read out of the FIFO and processed using appropriate circuitry to create a 3-D point cloud for creating a 3-D target image.

US Patent:

7436494, Oct 14, 2008

Filed:

Feb 15, 2007

Appl. No.:

11/706724

Inventors:

John Kennedy - Irvine CA, US
David Ludwig - Irvine CA, US
Christian Krutzik - Costa Mesa CA, US

Assignee:

Irvine Sensors Corp. - Costa Mesa CA

International Classification:

G01C 3/08

US Classification:

356 401

Abstract:

A 3-D LADAR imaging system incorporating stacked microelectronic layers is provided. A light source such as a laser is imaged upon a target through beam shaping optics. Photons reflected from the target are collected and imaged upon a detector array though collection optics. The detector array signals are fed into a multilayer processing module wherein each layer includes detector signal processing circuitry. The detector array signals are amplified, compared to a user-defined threshold, digitized and fed into a high speed FIFO shift register range bin. Dependant on the value of the digit contained in the bins in the register, and the digit's bin location, the time of a photon reflection from a target surface can be determined. A Ttrigger signal defines the reflection time represented at each bin location by resetting appropriate circuitry to begin processing. A reference insert circuit inserts data into the FIFO registers at a preselected location to provide a reference point at which all FIFO shift register data may be aligned to accommodate for timing differences between layers and channels.

US Patent:

8125367, Feb 28, 2012

Filed:

Jul 15, 2010

Appl. No.:

12/804267

Inventors:

David Ludwig - Irvine CA, US

Assignee:

Irvine Sensors Corp. - Costa Mesa CA

International Classification:

H03M 1/12

US Classification:

341155, 341122

Abstract:

A readout circuit which may be in the form of a readout integrated circuit or ROIC is disclosed for use in an AM chirp LADAR system having a photodetector coupled to a passive electronic filter. The filter output is coupled to a capacitive-coupled transimpedance amplifier with an output coupled to an analog storage register. The analog storage register output is coupled to a sample-and-hold circuit which in turn is coupled to an analog to digital converter circuit. In the stacked configuration, each IC operates independently and outputs its signals on a unique output line. The stacked ICs operate under the same set of control vectors as the individual ICs comprising the stack.

US Patent:

8198576, Jun 12, 2012

Filed:

Oct 10, 2008

Appl. No.:

12/287691

Inventors:

John Kennedy - Irvine CA, US
David Ludwig - Irvine CA, US
Christian Krutzik - Costa Mesa CA, US

Assignee:

Aprolase Development Co., LLC - Wilmington DE

International Classification:

G01C 3/08

US Classification:

250210, 356 401

Abstract:

A 3-D LADAR imaging system incorporating stacked microelectronic layers is provided. A reference insert circuit inserts data into the FIFO registers at a preselected location to provide a reference point at which all FIFO shift register data may be aligned to accommodate for timing differences between layers and channels. The bin data representing the photon reflections from the various target surfaces are read out of the FIFO and processed using appropriate circuitry such as a field programmable gate array to create a synchronized 3-D point cloud for creating a 3-D target image.

US Patent:

8279420, Oct 2, 2012

Filed:

Jul 16, 2010

Appl. No.:

12/804203

Inventors:

David Ludwig - Irvine CA, US
Medhat Azzazy - Laguna Niguel CA, US

Assignee:

ISC8 Inc. - Costa Mesa CA

International Classification:

G01C 3/08

US Classification:

356 501, 356 301, 356 401

Abstract:

A phase-sensing and scanning time-of-flight LADAR method and device are disclosed that take advantage of an atmospheric absorption bands within the solar IR spectrum. In the phase-sensing LADAR embodiment, an object is illuminated with electromagnetic energy such as a laser beam having a wavelength substantially equal to a predetermined atmospheric absorption band such as 1. 39 microns. The transmitted laser beam is modulated at a predetermined frequency and has a first phase. The phase of the reflected and returned laser beam is altered proportional to the distance of the object and has a second phase. The first phase of the transmitted signal and the second phase of the received signal are compared and used to determine the distance of the object from the device. The system may comprise a modified laser that is tuned to operate in an atmospheric absorption band. A method to identify range ambiguity is disclosed by periodically altering the modulation frequency from a first modulation frequency to a second modulation frequency.

US Patent:

RE43722, Oct 9, 2012

Filed:

Oct 28, 2009

Appl. No.:

12/607253

Inventors:

John Kennedy - Irvine CA, US
David Ludwig - Irvine CA, US
Christian Krutzik - Costa Mesa CA, US

Assignee:

Aprolase Development Co., LLC - Wilmington DE

International Classification:

G01C 3/08

US Classification:

356 401, 356 41, 356 501, 356 51

Abstract:

A 3-D LADAR imaging system incorporating stacked microelectronic layers is provided. A light source such as a laser is imaged upon a target through beam shaping optics. Photons reflected from the target are collected and imaged upon a detector array though collection optics. The detector array signals are fed into a multilayer processing module wherein each layer includes detector signal processing circuitry. The detector array signals are amplified, compared to a user-defined threshold, digitized and fed into a high speed FIFO shift register range bin. Dependant on the value of the digit contained in the bins in the register, and the digit's bin location, the time of a photon reflection from a target surface can be determined. A Ttrigger signal defines the reflection time represented at each bin location by resetting appropriate circuitry to begin processing. A reference insert circuit inserts data into the FIFO registers at a preselected location to provide a reference point at which all FIFO shift register data may be aligned to accommodate for timing differences between layers and channels.

US Patent:

RE43877, Dec 25, 2012

Filed:

Feb 25, 2010

Appl. No.:

12/712810

Inventors:

David Ludwig - Irvine CA, US
James Yamaguchi - Laguna Niguel CA, US
Stewart Clark - Newport Beach CA, US
W. Eric Boyd - Irvine CA, US

Assignee:

Aprolase Development Co., LLC - Wilmington DE

International Classification:

H01L 21/00

US Classification:

438462, 438110, 438742, 438464, 257E21599

Abstract:

A preprocessed semiconductor substrate such as a wafer is provided with a metal etch mask which defines singulation channels on the substrate surface. An isotropic etch process is used to define a singulation channel with a first depth extending into the semiconductor substrate material. A second anisotropic etch process is used to increase the depth of the singulation channel while providing substantially vertical singulation channel sidewalls. The singulation channel can be extended through the depth of the substrate or, in an alternative embodiment, a predetermined portion of the inactive surface of the substrate removed to expose the singulation channels. In this manner, semiconductor die can be precisely singulated from a wafer while maintaining vertical die sidewalls.

US Patent:

20040188596, Sep 30, 2004

Filed:

Mar 22, 2004

Appl. No.:

10/805849

Inventors:

David Ludwig - Irvine CA, US
John Kennedy - Irvine CA, US
Christian Krutzik - Costa Mesa CA, US

International Classification:

G09G005/00

US Classification:

250/208100

Abstract:

A 3-D LADAR imaging system incorporating stacked microelectronic layers is provided. A light source is imaged upon a target through beam shaping optics. Photons reflected from the target are collected and imaged upon a detector array though collection optics. The detector array signals are fed into a multilayer processing module wherein each layer includes detector signal processing circuitry. The detector array signals are amplified, compared to a user-defined threshold, digitized and fed into a high speed FIFO range bin. Dependant on the value of the digit contained in the bins in the register, and the digit's bin location, the time of a photon reflection from a target surface can be determined. A Ttrigger signal defines the reflection time represented by each bin location by resetting appropriate circuitry to begin processing. The bin data representing the photon reflections from the various target surfaces are read out of the FIFO and processed using appropriate circuitry to create a 3-D point cloud for creating a 3-D target image.