Patent ID: 8022972

Claim:
An automatic coarseness setting method comprising: detecting a pixel clock of an input video signal; selecting one of a plurality of coarseness ranges and setting one value from among a plurality of coarseness values within the selected coarseness range as a coarseness value for displaying the input video signal on a screen, based on the pixel clock; determining whether the pixel clock of the input video signal is included in the selected coarseness range; if it is determined that the pixel clock is included in the selected coarseness range, changing a preset coarseness value to the set one value corresponding to the pixel clock, which sets the coarseness range as the selected one of the plurality of coarseness ranges; if it is determined that the pixel clock is not included in the selected coarseness range, determining whether the selected coarseness range has been shifted; if it is determined that the selected coarseness range has been shifted, restoring the selected coarseness range to an original coarseness range; and if it is determined that the selected coarseness range has not been shifted, shifting the selected coarseness range to another one of the plurality of coarseness ranges and changing the set coarseness value to a value of the pixel clock of the input video signal.