Flat panel display attribute generator

Abstract

An electronic terminal employs a liquid crystal display for displaying desired characters. The terminal has circuitry for providing attributes to the characters, on a character-by-character basis or on a plurality of characters basis. These attributes include double width, double height, underline, inversion and intensity control. These attributes are formed using minimal additional memory and circuitry.

Description

BACKGROUND OF THE INVENTION1. Field of the InventionThis invention relates to electronic systems having flat planel displays and more particularly to a flat panel display that employs a full range of attributes.2. Description of the Prior ArtIn the past, attributes for liquid crystal displays have been formed by recreating a character set for each attribute or combination of attributes desired. These are not truly attributes, but rather character sets that emulate the attributes for character presentations. This arrangement of displaying character attributes is expensive for each character in terms of hardware, specifically storage.Another prior art method is to employ a very fast processor for real time storing of a modified character font into a character generator. However, this system is expensive since the processor, memory speed, and support logic must be very fast to store characters, modify characters, and display characters as fast as the communication link is providing pre...

AI Technical Summary

Benefits of technology

Desk top terminals are designed with high quality CRT displays using host-to-terminal presentation protocols that enhance the readability of the characters displayed on the CRT. These protocols define video attributes that affect the visual presentation of the displayed characters on the CRT. The CRT uses a raster scan technology and the generation of individual attributes and combinations of these attributes is straightforward.

This invention provides for a method of display and attribute definition to define either combined character and attribute flags within the same device, or separate display character and attribute memory. Only the method of decoding the attribute flags changes with the storage technique. In this preferred embodiment, the implementation of the screen and attribute memory is in separate memories to enhance the number of communication terminal protocols that can be supported without major logic changes, but this is an engineering design choice.

Problems solved by technology

The display devices to date, however, have had a limitation as to the quality of the display and the quality of the characters displayed.

In many cases, the LCD display was able to generate one attribute, but lacked the ability to generate multiple attributes with the same quality as the CRT.

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