Flat display unit and method for converting color signal in the unit

1. A flat display unit comprising:

a pixel group which is two-dimensionally arranged in a display region and in which pixels for red (R), green (G), and blue (B) are repeatedly arranged in a row direction;

a source drive circuit which outputs signals to a signal line group every scanning period and which supplies the signals to the corresponding pixels for red (R), green (G), and blue (B);

a color signal interpolation circuit which defines an input video signal of green (G) as a first color signal of a reference, and the other two input video signals as second and third color signals,

and which multiplies a plurality of time-shifted samples of the second color signal by co-efficients, respectively, and synthesizes the samples to generate a first interpolation color signal as the R system,

and which multiples a plurality of time-shifted sample of the third color signal by coefficients, respectively, and synthesizes the samples to generate a second interpolation color signal as the B system;

the color signal interpolation circuit including a circuit for defining a Gn signal as a center of a phase, denoting an integer with n, and obtaining the following calculation outputs in a position of a phase delayed behind Gn by one clock in order to obtain two interpolation samples between the respective samples of the R, G, B input video signals:

Rna =(⅔)× Rn +(⅓) R ( n+ 1),

Gna =(⅔)× Gn +(⅓) G ( n+ 1), and

Bna =(⅔)× Bn +(⅓) B ( n+ 1);

a circuit for obtaining the following calculation outputs in a position of a phase advanced ahead of Gn by one clock:

Rnb =(⅓) Rn +(⅔) R ( n+ 1),

Gnb =(⅓) Gn +(⅔) G ( n+ 1), and

Bnb =(⅓) Bn +(⅔) B ( n+ 1); and

a circuit for obtaining Gn=Gn in a phase position of Gn; and

a signal output circuit which supplies to the source drive circuit the first color signal, the first interpolation color signal, and the second interpolation color signal obtained.

2. The flat display unit according to claim 1 , which further subjects the signal of the phase of Gn to filtering of (¼)Gnb+(½)Gn+(¼)Gb to obtain a calculation output of ((10×Gn+G(n−1)+G(n+1))/12).

3. A flat display unit, comprising:

a pixel group which is two-dimensionally arranged in a display region and in which pixels for red (R), green (G), and blue (B) are repeatedly arranged in a row direction;

a source drive circuit which outputs signals to a signal line group every scanning period and which supplies the signals to the corresponding pixels for red (R), green (G), and blue (B);

a color signal interpolation circuit which defines an input video signal of green (G) as a first color signal of a reference, and the other two input video signals as second and third color signals;

and which multiplies a plurality of time-shifted samples of the second color signal by coefficients, respectively, and synthesizes the samples to generate a first interpolation color signal as the R system, and arranges the first interpolation color signal at the front side of the first color signal position on time axis,

and which multiplies a plurality of time-shifted sample of a third color signal by coefficients, respectively, and synthesizes the samples to generate a second interpolation color signal as the B system, and

a signal output circuit which supplies to the source drive circuit the first color signal, the first interpolation color signal, and the second interpolation color signal obtained,

wherein the color signal interpolation circuit processes the green (G) video signal as the first color signal,

the color signal interpolation circuit comprises:

a 0 insertion circuit which inserts two zeros between the respective samples with respect to the first to third color signals, respectively;

a filtering circuit which filters the respective 0-inserted color signals with different weightings, respectively; and

a sampling circuit which samples and extracts the respective filtered outputs in desired phases, respectively,

wherein the filtering circuit comprises at least six delay elements which successively delay the 0-inserted color signals to obtain seven output signals having different phases,

defines a Gn signal as a center of a phase, denotes an integer with n, and obtains a B(n−1)b signal of a phase which is one clock before the Gn signal by a calculation of:

B ( n− 1) b =(4 ×B ( n− 1)+8 ×B ( n+ 1))/12,

obtains an Rna signal of a phase which is one clock after the Gn signal by a calculation of:

Rna =(8× Rn+ 8 ×R ( n+ 1))/12, and

obtains the Gn signal by a calculation of:

Gn =(10 ×Gn+G ( n− 1)+ G ( n+ 1))/12.