Browse Prior Art Database

Automatic Contrast Adjustment of Liquid Crystal Display Screens

IP.com Disclosure Number: IPCOM000113146D
Original Publication Date: 1994-Jul-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 51K

Publishing Venue

IBM

Related People

Miller, RV: AUTHOR [+2]

Abstract

Described is a technique to provide an automatic adjustment of the contrast setting of Liquid Crystal Display (LCD) devices, as used in hand-held, laptop and mobile Personal Computers (PCs). The technique utilizes data from sensors incorporated in the battery recharging circuitry.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 74% of the total text.

Automatic Contrast Adjustment of Liquid Crystal Display Screens

      Described is a technique to provide an automatic adjustment of
the contrast setting of Liquid Crystal Display (LCD) devices, as used
in hand-held, laptop and mobile Personal Computers (PCs).  The
technique utilizes data from sensors incorporated in the battery
recharging circuitry.

      In environments where LCD screens are utilized, temperature
changes can affect the contrast settings, which in turn can affect
the readability of the LCD screens.  In prior art, when temperature
changes occurred, due to the movement of the portable PCs from one
environment to another, a manual adjustment of the contrast setting
was used in order to attain a readable screen.  Also, in other prior
art, automatic adjustment used a separate sensor in order to detect
and calculate temperature changes of an LCD screen and to adjust the
contrast setting.

      The concept described herein eliminates the need to manually
adjust, or to use a separate sensor, in the contrast setting
adjustment by utilizing data from sensors already installed.  This
data is used to detect and automatically adjust for varying
temperature environments.  This operation is performed automatically
by the Basic Input Output System (BIOS) in the PC.

      The rechargeable battery installed in mobile PCs is the usual
source of power in environments where LCD screens are utilized.  The
charging circuits, used to recharge the battery,...