Browse Prior Art Database

Automatic Image Brightness Compensation

IP.com Disclosure Number: IPCOM000061405D
Original Publication Date: 1986-Jun-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Vilter, PF: AUTHOR

Abstract

Automatic brightness adjustment is made any time a computer terminal operator changes the presentation mode, i.e. light characters on a dark background to dark characters on light background or vice versa. Although this gross brightness balancing is done automatically, the manual brightness con remains active for any further or fine adjustments.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 1

Automatic Image Brightness Compensation

Automatic brightness adjustment is made any time a computer terminal operator changes the presentation mode, i.e. light characters on a dark background to dark characters on light background or vice versa. Although this gross brightness balancing is done automatically, the manual brightness con remains active for any further or fine adjustments.

Screen brightness of the computer terminal is raised or lowered in 60 mv increments for each step of the terminal video DAC (Digital To Analog Converter). Four steps are used for screen brightness adjustment between forward and reverse screen images. The brightness value is loaded under microprocessor control into register 10 and consists of 31 brightness bits. Five brightness change bits are applied from register 10 to VDAC 20 which provides an output voltage to the video monitor or terminal, not shown.

Disclosed anonymously.

1