Browse Prior Art Database

Dot Stretch

IP.com Disclosure Number: IPCOM000100361D
Original Publication Date: 1990-Apr-01
Included in the Prior Art Database: 2005-Mar-15
Document File: 4 page(s) / 114K

Publishing Venue

IBM

Related People

Sohda, M: AUTHOR

Abstract

The traditional stretch method is to stretch vertical lines of a character image horizontally with a high resolution CRT display as shown in Fig. 1. As shown in the Fig. 2, case #1, if there is no other color element except for a character image in a character box, the traditional method has no problem. But if a character box contains other color elements, such as a background color (shown in Fig. 2, case #2, as an example), a ruler cursor, a trimming line, etc., the old method causes trouble. In this example, the character image is yellow (RED : on, GREEN : on, BLUE : off), and the background color is blue. The old method stretches only character image, as in case #2, and it causes an unintentional line (white line in this case) because Red and Green signals overlap to Blue signal.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Dot Stretch

       The traditional stretch method is to stretch vertical
lines of a character image horizontally with a high resolution CRT
display  as shown in Fig. 1.  As shown in the Fig. 2, case #1, if
there is no other color element except for a character image in a
character box, the traditional method has no problem.  But if a
character box contains other color elements, such as a background
color (shown in Fig. 2, case #2, as an example), a ruler cursor, a
trimming line, etc., the old method causes trouble.  In this example,
the character image is yellow (RED : on, GREEN : on, BLUE : off), and
the background color is blue.  The old method stretches only
character image, as in case #2, and it causes an unintentional line
(white line in this case) because Red and Green signals overlap to
Blue signal.

      This article describes a new dot stretch method which
eliminates this overlapped portion, as in case #3, and enhances to
make a variable stretch length for both normal and reverse mode.

      To realize this method, a circuit diagram (for Red signal) is
shown in Fig. 3 for an example.  The other circuits of Green and Blue
can be the same circuit as the Red except for a common portion.
"(Red) Serial Signal" is a scan line image which is adequately
processed by an attribute controller.  A positive pulse in normal
mode or a negative pulse in reverse mode or for background in normal
mode means a dot of character to be displayed.  This signal goes to
D-Flip Flop (D-FF #1), a low-level stretch generator (Low STR Gen)
and a high-level stretch generator (High STR Gen).  "Dot CLK" is a
clock to synchronize all DOT STRETCH video signals.  "Stretch
Position" directs positions in "Serial Signal" to be stretched and
generates negative pulses and positive pulses in "Low STR Gen" and
"High STR Gen", respectively.  This is shown in F...