Browse Prior Art Database

Quasi-Interlace Method using Line Memory to Display Interlace Video Signal on a TFT LCD

IP.com Disclosure Number: IPCOM000115437D
Original Publication Date: 1995-May-01
Included in the Prior Art Database: 2005-Mar-30
Document File: 2 page(s) / 61K

Publishing Venue

IBM

Related People

Matsuse, S: AUTHOR [+2]

Abstract

Disclosed is a method conversion from interlace scan to non-interlace using less memory resources and quasi-interlace. For example, a TFT LCD cannot do interlace scan originally, but the method makes it become easy to display some interlaced image like NTSC which is one of the standard TV signals in the world wide. The method does not use frame memories to convert the scan mode, but uses only two line memories for quasi-interlace.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 65% of the total text.

Quasi-Interlace Method using Line Memory to Display Interlace Video
Signal on a TFT LCD

      Disclosed is a method conversion from interlace scan to
non-interlace using less memory resources and quasi-interlace.  For
example, a TFT LCD cannot do interlace scan originally, but the
method makes it become easy to display some interlaced image like
NTSC which is one of the standard TV signals in the world wide.  The
method does not use frame memories to convert the scan mode, but uses
only two line memories for quasi-interlace.

      The method will be best understood with reference to the
drawing of the timing of VGA (non-interlace) and NTSC (interlace) and
quasi-interlace.  The horizontal direction of the drawings show a
time based on the scan line number on the display, and vertical
direction shows forwarding structure of the scan line.  The slope up
to the right means that the scan runs on the display from left to
right side.  And the scan returns back to the left side.  The first
scan starts at the arrow of start.  The under score shows blank time
which is behind the available display line, or shows black line.  The
time lag of the start point between odd and even field indicates
interlace scan on the both of the NTSC and the quasi-interlace memory
write.

      At the case of quasi-interlace, two line memory is used, and
the image data is written on one line memory of the two, then the
written data is read twice at the next scan.  This is described...