US 5,495,263 A · Identification of liquid crystal display panels

Abstract

A method that identifies the type of LCD panel used in a portable computer system based on the frequency of the oscillator signal of the DC-to-AC inverter in the LCD panel. In this method, only one signal is routed from the LCD panel to the base unit of the portable computer system for the purpose of panel identification. The inverter oscillating signal is used to increment a counter during power on operations. A system counter, which is clocked by a system clock, is used to determine the number of system clocks needed for the panel identification counter to reach a predetermined count. That number is compared with the entries of a table, in which each entry corresponds to a type of LCD panel. In this manner, the type of LCD panel can be identified based on the frequency of the inverter signal. A corresponding entry in a second table is accessed to obtain a table entry for the identified LCD panel to a full table of LCD panel parameters. The table entry is stored in a predetermined location in the Video ROM. During the video power on portion of the BIOS, the video BIOS routines access the predetermined location in the Video ROM to obtain the parameters to properly initialize the video controller.

Claims7

Dependent claims

A method of identifying types of liquid crystal display panels, the method comprising the steps of:

providing an oscillating signal generated in the liquid crystal display panel;
determining a value that represents the relation between the oscillating signal period and the period of a computer system clock signal having a period less than the oscillating signal period;
and
comparing said value with the entries of a table to determine the type of the liquid crystal display panel.

1 more element

A computer system, comprising:

a microprocessor;
a liquid crystal display panel including means for generating an oscillating signal having a period;
a clock generator producing a clock signal having a period less than said oscillating signal period;
means coupled to said microprocessor and to said liquid crystal display panel to receive said oscillating signal and connected to said clock generator to receive said clock signal for determining a value that represents the relation between said oscillating signal period and said clock signal period;
and
means coupled to said microprocessor for storing a first table containing values that represent different types of liquid crystal display panels, wherein said microprocessor compares said relation value with said first table values to determine the type of said liquid crystal display panel.

3 more elements

Dependencies are inferred from the claim text.

Identification of liquid crystal display panels

Life of this patent

Identification of liquid crystal display panels

Life of this patent

Abstract

Claims7