Patent Document ID: 20040263539
Application ID: 10800776
Patent Status: 0

Claim One:
1. A signal processor for multiple gradations for replacing one field with a plurality of subfields weighted with a predetermined luminance and coding a lit or unlit state of each display cell on a subfield basis in an input image signal having a predetermined number of gradations for each primary color, the processor comprising: a main path for generating a primary color signal having a first number of gradations from a primary color signal of an input image signal having the predetermined number of gradations, the first number of gradations being equal to or smaller than the predetermined number of gradations; a sub-path for generating a primary color signal having a second number of gradations, the second number of gradations being smaller than the first number of gradations; a switch for switching so that either of the signal generated by the main path and the signal generated by the sub-path is output; a movement detection circuit for detecting a moving area and the amount of movement by detecting the change in a primary color signal on a pixel basis between the current field and the preceding field of the input image signal; a level detection circuit for detecting and outputting the amount of level indicating the tendency for a moving image false contour to occur on a pixel basis for each primary color signal in the main path; a path switching control circuit for switching the switch from the main path output to the sub-path output based on the detected amount of movement and amount of level; plural subfield coding circuits for receiving the signal output from the switch thereto and for outputting a converted signal by carrying out different subfield coding, respectively; a superposing circuit for receiving the output of the plural subfield coding circuits thereto and selecting one of the input signals; and a superposing control circuit for controlling the selection of the output of the plural subfield coding circuits in the superposing circuit for each primary color signal on a pixel basis.