Christopher P Sexton

US Patent:

55304893, Jun 25, 1996

Filed:

Oct 5, 1994

Appl. No.:

8/318532

Inventors:

Alan R. Henderson - Carlsbad CA
Christopher S. Sexton - San Diego CA

International Classification:

H04N 931

US Classification:

348757

Abstract:

Color separation dichroic mirrors (40,42) positioned between a group of reflective liquid crystal light valves (26,28,30) and a polarization analyzer (14) enable a single projection lens (18) to project all colors via a light beam of single linear polarization with a high degree of contrast, efficiency and color separation. The polarization analyzer (14) directs a light beam with a single polarization state to a pair of dichroic color filters (40,42) which separate the beam into three different colors that are sent to three different reflective liquid crystal light valves (26,28,30). The light valves reflect the respective colored light beams with change of polarization state back to the dichroic mirrors (40,42) which combine the three colors into a single combined multi-color beam that is fed through the polarization analyzer (14) to a single system projection lens (18).

US Patent:

51990547, Mar 30, 1993

Filed:

Aug 30, 1990

Appl. No.:

7/575550

Inventors:

John A. Adams - Escondido CA
Bruce D. Baker - Olivenhain CA
Kerry L. Brown - Temecula CA
Robert L. Corey - San Diego CA
Brian L. Ganz - San Diego CA
David C. Reynolds - San Marcos CA
Edward W. Ross - Escondido CA
Gerald S. Russell - San Diego CA
Christopher S. Sexton - San Diego CA

Assignee:

Four Pi Systems Corporation - San Diego CA

International Classification:

H01J 3508

US Classification:

378 21

Abstract:

A high resolution laminography system for the inspection of integrated circuits wherein a beam of highly focused electrons is traced in a circular pattern on a flat target within a vacuum chamber. The target converts the electron beam into X-rays, so that a source of X-rays is produced which rotates in synchronization with a rotating detector assembly. An object is placed within the vacuum chamber, between the X-ray source and the detector so that an X-ray cross sectional image of a cutting plane of the object is produced. A computer and feedback system controls image acquisition and an automated positioning system. The computer system can also operate under program control to automatically analyze data, measure characteristics of the object under inspection, and make decisions regarding the acceptability of the object's quality. The invention also employs a channeltron imager to directly image the target so that the condition of the target may be monitored, and electron drift within the system can be compensated for.

US Patent:

20210328402, Oct 21, 2021

Filed:

Apr 16, 2021

Appl. No.:

17/232492

Inventors:

- Solana Beach CA, US
Jinendra S. Ranka - San Diego CA, US
Christopher S. Sexton - San Diego CA, US
Brett A. Spivey - Carlsbad CA, US
Kyle D. Watson - Carlsbad CA, US

International Classification:

H01S 3/13
G01S 7/4911
G01B 9/02

Abstract:

Various disclosed embodiments provide illustrative interferometers, optical phase locked loops, laser systems, interferometry methods, and phase locked loop methods. In illustrative embodiments, light from a laser is split into a first arm and a second arm. Light in an arm chosen from the first arm and the second arm is time delayed. The light in the first arm is split into third, fourth, and fifth arms. The light in the second arm is split into sixth, seventh, and eighth arms. Light in the seventh and eighth arms is phase shifted relative to light in the sixth arm. Light in the third, fourth, and fifth arms is combined with light in the sixth arm and phase shifted light in the seventh and eighth arms, respectively. A frequency correction signal for the laser is generated.