Television – Synchronization – Sync separation
Reexamination Certificate
1994-11-30
2001-05-01
Lee, Michael (Department: 2614)
Television
Synchronization
Sync separation
C348S530000
Reexamination Certificate
active
06226044
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to a field synchronization system and technique and more specifically, to a field synchronization system and technique of a field detect circuit adaptable for use with non-standard output digital data ports of forward looking infrared (FLIR) sensors.
2. Description of Prior Art
Television is the transmission of scenes, either still or in motion, by electrical means. It is necessary to break up the scene into minute elements and utilize these elements in an orderly sequence. This process is called scanning, a type of which is somewhat similar to the process of reading a text line-by-line (or row of data) from a printed page (called interlacing). Because of the physical principles involved, there is a relationship between brightness and the rate of scanning: brightness going down with increase scanning rate. To provide a true and realistic feeling of motion to all actions displayed, it is necessary to present a number of pictures or frames per second. Early designers in compromising on brightness, utilized a reasonable transmission bandwidth, and frame frequency, selected a rate of display of 30 complete pictures per second. A frame frequency of only 30 pictures/second would result in a flicker discernible to the eye, so each picture is divided into two parts called fields. Two fields must be produced in order to make one complete picture or frame. The field frequency is therefore 60 fields/second and the frame frequency is 30 frames/second. Each field contains one-half of the total picture elements.
For a decernible picture to be presented, there requires a digital timing protocol for the differentiation and synchronization of the two fields into one interlaced frame of digital information that is utilized by a field detect circuitry. A problem occurs in the prior art when the digital data inputs to the field circuitry does not follow the SMPTE Standard 244M known in the Prior Art. Many FLIR sensors output their own field index but do not follow the accepted protocol with respect to the falling edges of the horizontal and vertical synchronization signals. While the prior art has reported using field detect circuits, none have established a basis for a specific apparatus that is dedicated to the task of resolving the particular problem at hand. What is needed in this instance is a field synchronization system and technique of a field detect circuit adaptable for use with non-standard output digital data ports of forward looking infrared (FLIR) sensors.
SUMMARY OF THE INVENTION
It is therefore one object of the invention to provide a field synchronization system and technique of a field detect circuit adaptable for use with non-standard output digital data ports of forward looking infrared (FLIR) sensors.
According to the invention, a field synchronization system of a field detect circuit adaptable for use with non-standard output digital data of forward looking infrared (FLIR) sensors is disclosed. Timing signals, along with digital data are input from a FLIR sensor. There is output from a frame grabber, the vertical and horizontal signal outputs, and a generated field index signal. A Jumper allows for user selection of the standard frame grabber generated field index signal or the externally provided field index signal, thus bypassing the frame grabber field index circuitry.
REFERENCES:
patent: 4460918 (1984-07-01), Flasza
patent: 5025496 (1991-06-01), Canfield
patent: 5327175 (1994-07-01), Kim
“Imaging With Speed Trapix Plus” Recognition Concepts, Inc. product brouchure, Jan. 13, 1996.*
Society of Motion Picture and Television Engineers; “Proposed SMPTE Standard for Television—System M/NTSC Composite Video Signals-Bit-Parallel Digital Interface”; Oct., 1993; pp. 1-17.
Bashore Alain L.
Holford John E.
Lee Michael
Lee Milton W.
The United States of America as represented by the Secretary of
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