Identification of liquid crystal display panels
First Claim
1. A method of identifying the type of a liquid crystal display panel for use in a computer system, wherein the liquid crystal display panel receives a plurality of video signals including a pixel clock and pixel data, the method comprising the steps of:
- providing an oscillating signal having a period and which is generated in the liquid crystal display panel, said oscillating signal being other than said plurality of video signals;
determining a value that represents the relation between said oscillating signal period and the period of a computer system clock signal; and
comparing said value with the entries of a table to determine the type of the liquid crystal display panel.
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Accused Products
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.
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Citations
12 Claims
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1. A method of identifying the type of a liquid crystal display panel for use in a computer system, wherein the liquid crystal display panel receives a plurality of video signals including a pixel clock and pixel data, the method comprising the steps of:
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providing an oscillating signal having a period and which is generated in the liquid crystal display panel, said oscillating signal being other than said plurality of video signals; determining a value that represents the relation between said oscillating signal period and the period of a computer system clock signal; and comparing said value with the entries of a table to determine the type of the liquid crystal display panel. - View Dependent Claims (2, 3, 4)
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5. A method of initializing a video controller that provides a plurality of video signals including a pixel clock and pixel data to a liquid crystal display panel in a computer system, wherein the video controller is initialized with parameters stored in a storage device which contains different sets of parameters associated with different types of liquid crystal display panels, the method comprising the steps of:
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identifying the type of liquid crystal display panel, said identifying step including the steps of; providing an oscillating signal having a period generated in the liquid crystal display panel, said oscillating signal being other than said plurality of video signals; determining a value that represents the relation between said oscillating signal period and the period of a computer system clock signal; and comparing said value with the entries of a table to determine the type of the liquid crystal display panel; and retrieving from the storage device the set of parameters associated with the identified type of the liquid crystal display panel for initializing the video controller. - View Dependent Claims (6)
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7. A computer system, comprising:
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a microprocessor; a liquid crystal display panel receiving a plurality of video signals and including a generator for generating an oscillating signal having a first period, said oscillating signal being other than said plurality of video signals; a video controller which provides said plurality of video signals; a clock generator producing a clock signal having a second period; an analyzer responsive to said oscillating signal and said clock signal for determining a value that represents the relation between said oscillating signal period and said clock signal period; and a storage device 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. - View Dependent Claims (8, 9, 10, 11, 12)
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Specification