Method of driving image display device

A method of driving an image display device that includes (A) an image display panel in which pixels each having a first subpixel displaying a first primary color, a second subpixel displaying a second primary color, and a third subpixel displaying a third primary color are arranged in a two-dimensional matrix in a first direction and a second direction, at least a first pixel and a second pixel arranged in the first direction forms a pixel group, and a fourth subpixel displaying a fourth color is arranged between the first pixel and the second pixel in each pixel group, and (B) a signal processor, the method comprising:

• (1) in an i-th image display frame, in the signal processor:
• (a) in regard to the first pixel,
• (i) obtaining a first subpixel output signal on the basis of at least a first subpixel input signal and a corrected expansion coefficient α′i-0 and outputting the first subpixel output signal to the first subpixel,
• (ii) obtaining a second subpixel output signal on the basis of at least a second subpixel input signal and the corrected expansion coefficient α′i-0, and outputting the second subpixel output signal to the second subpixel, and
• (iii) obtaining a third subpixel output signal on the basis of at least a third subpixel input signal and the corrected expansion coefficient α′i-0, and outputting the third subpixel output signal to the third subpixel,
• (b) in regard to the second pixel,
• (i) obtaining a first subpixel output signal on the basis of at least a first subpixel input signal and a corrected expansion coefficient α′i-0, and outputting the first subpixel output signal to the first subpixel,
• (ii) obtaining a second subpixel output signal on the basis of at least a second subpixel input signal and the corrected expansion coefficient α′i-0, and outputting the second subpixel output signal to the second subpixel, and
• (iii) obtaining a third subpixel output signal on the basis of at least a third subpixel input signal and the corrected expansion coefficient α′i-0, and outputting the third subpixel output signal to the third subpixel, and
• (c) in regard to the fourth subpixel,
• obtaining a fourth subpixel output signal on the basis of a fourth subpixel control first signal obtained from the first subpixel input signal, the second subpixel input signal, and the third subpixel input signal to the first pixel and a fourth subpixel control second signal obtained from the first subpixel input signal, the second subpixel input signal, and the third subpixel input signal to the second pixel, and outputting the fourth subpixel output signal to the fourth subpixel;
• (2) obtaining in the signal processor or storing in the signal processor a maximum value Vmax(S) of luminosity with a saturation S in an HSV color space enlarged by adding the fourth color as a variable;
• and
• (3) in the i-th image display frame, in the signal processor:
• (a) obtaining a saturation Si and a luminosity Vi(S) in a plurality of pixels on the basis of subpixel input signal values in the plurality of pixels,
• (b) obtaining an expansion coefficient αhd i-0 on the basis of at least one of the values of Vmax(S)/Vi(S) obtained in the plurality of pixels, and
• (c) determining the corrected expansion coefficient α′i-0 on the basis of a value obtained by
• (i) calculating a difference between (1) a first reciprocal of the expansion coefficient αi-0 obtained in the i-th image display frame and (2) a second reciprocal of a corrected expansion coefficient α′(i−j)-0 applied in advance in an (i−j)th image display frame (where j is a positive integer equal to or greater than 1),
• (ii) obtaining a correction value corresponding to the difference, and
• (iii) adding or subtracting the correction value to or from the second reciprocal,
• wherein,
• the saturation S and the luminosity V(S) are represented as follows:
• S=(Max−Min)/Max
• V(S)=Max
• where, Max is a maximum value among three subpixel input signal values including a first subpixel input signal value, a second subpixel input signal value, and a third subpixel input signal value to the pixel, and
• Min is a minimum value among the three subpixel input signal values including the first subpixel input signal value, the second subpixel input signal value, and the third subpixel input signal value to the pixel;
• (a) the correction value includes Δ1, Δ2, Δ3, and Δ4;
• (b) when Δ1>Δ2>0 and Δ4>Δ3 >0, a first predetermined value is ε1, a second predetermined value is ε2, a third predetermined value is ε3, a fourth predetermined value is ε4, ε1 <ε2<0, and ε4>ε3>0;
• (c) if a value of the difference is smaller than the first predetermined value ε1, the corrected expansion coefficient α′i-0 is calculated on the basis of the following expression:
• (1/α′i-0)=(1/α′(i−j)-0)−Δ1;
• (d) if the value of the difference is equal to or greater than the first predetermined value ε1 and smaller than the second predetermined value ε2, the corrected expansion coefficient α′i-0 is calculated on the basis of the following expression:
• (1/α′i-0)=(1/α′(i−j)-0)−Δ2;
• (e) if the value of the difference is equal to or greater than the second predetermined value ε2 and smaller than the third predetermined value ε3, the corrected expansion coefficient α′i-0 is calculated on the basis of the following expression:
• (1/α′i-0)=(1/α′(i−j)-0);
• (f) if the value of the difference is equal to or greater than the third predetermined value ε3 and smaller than the fourth predetermined value ε4, the corrected expansion coefficient α′i-0 is calculated on the basis of the following expression:
• (1/α′i-0)=(1/α′(i−j)-0)+Δ3;
• and
• (g) if the value of the difference is equal to or greater than the fourth predetermined value ε4, the corrected expansion coefficient α′i-0 is calculated on the basis of the following expression:
• (1/α′i-0)=(1/α′(i−j)-0)+Δ4.

A method of driving an image display device, wherein

• the image display device includes (A) an image display panel in which P×Q pixel groups in total of P pixel groups in a first direction and Q pixel groups in a second direction are arranged in a two-dimensional matrix, and (B) a signal processor,
• each pixel group has a first pixel and a second pixel in the first direction,
• the first pixel has a first subpixel displaying a first primary color, a second subpixel displaying a second primary color, and a third subpixel displaying a third primary color,
• the second pixel has a first subpixel displaying the first primary color, a second subpixel displaying the second primary color, and a fourth subpixel displaying a fourth color, the method comprising:
• (1) in an i-th image display frame, in the signal processor:
• (a) obtaining a third subpixel output signal to a (p,q)th [where p=1, 2, ..., P, and q=1, 2, ..., and Q] first pixel when counting in the first direction on the basis of at least a third subpixel input signal to the (p,q)th first pixel, a third subpixel input signal to a (p,q)th second pixel, and a corrected expansion coefficient α′i-0, and outputting the third subpixel output signal to the third subpixel of the (p,q)th first pixel, and
• (b) obtaining a fourth subpixel output signal to the (p,q)th second pixel on the basis of a fourth subpixel control second signal obtained from a first subpixel input signal, a second subpixel input signal, and the third subpixel input signal to the (p,q)th second pixel, a fourth subpixel control first signal obtained from a first subpixel input signal, a second subpixel input signal, and a third subpixel input signal to an adjacent pixel adjacent to the (p,q)th second pixel in the first direction, and the corrected expansion coefficient α′i-0, and outputting the fourth subpixel output signal to the fourth subpixel of the (p,q)th second pixel;
• (2) obtaining in the signal processor or storing in the signal processor a maximum value Vmax(S) of luminosity with a saturation S in an HSV color space enlarged by adding a fourth color as a variable;
• and
• (3) in the i-th image display frame, in the signal processor:
• (a) obtaining a saturation Si and a luminosity Vi(S) in a plurality of pixels on the basis of subpixel input signal values in the plurality of pixels,
• (b) obtaining an expansion coefficient αhd i-0 on the basis of at least one of the values of Vmax(S)/Vi(S) obtained in the plurality of pixels, and
• (c) determining the corrected expansion coefficient α′i-0, on the basis of a value obtained by
• (i) calculating a difference between (1) a first reciprocal of the expansion coefficient αi-0 obtained in the i-th image display frame and (2) a second reciprocal of a corrected expansion coefficient α′(i−)-0 applied in advance in an (i−j)th image display frame (where j is a positive integer equal to or greater than 1),
• (ii) obtaining a correction value corresponding to the difference, and
• (iii) adding or subtracting the correction value to or from the second reciprocal,
• wherein,
• the saturation S and the luminosity V(S) are represented as follows:
• S=(Max−Min)/Max
• V(S)=Max
• where, Max is a maximum value among three subpixel input signal values including a first subpixel input signal value, a second subpixel input signal value, and a third subpixel input signal value to the pixel, and
• Min is a minimum value among the three subpixel input signal values including the first subpixel input signal value, the second subpixel input signal value, and the third subpixel input signal value to the pixel;
• (a) the correction value includes Δ1, Δ2, Δ3, and Δ4;
• (b) when Δ1>Δ2>0 and Δ4>Δ3 >0, a first predetermined value is ε1, a second predetermined value is ε2, a third predetermined value is ε3, a fourth predetermined value is ε4, ε1<ε2<0, and ε4>ε3>0;
• (c) if a value of the difference is smaller than the first predetermined value ε1, the corrected expansion coefficient α′i-0 is calculated on the basis of the following expression:
• (1/α′i-0)=(1/α′(i−j)-0)−Δ1;
• (d) if the value of the difference is equal to or greater than the first predetermined value ε1 and smaller than the second predetermined value ε2, the corrected expansion coefficient α′i-0 is calculated on the basis of the following expression:
• (1/α′i-0)=(1/α′(i−j)-0)−Δ2;
• (e) if the value of the difference is equal to or greater than the second predetermined value ε2 and smaller than the third predetermined value ε3, the corrected expansion coefficient α′i-0 is calculated on the basis of the following expression:
• (1/α′i-0)=(1/α′(i−j)-0);
• (f) if the value of the difference is equal to or greater than the third predetermined value ε3 and smaller than the fourth predetermined value ε4, the corrected expansion coefficient α′i-0 is calculated on the basis of the following expression:
• (1/α′i-0)=(1/α′(i−j)-0)+Δ3;
• and
• (g) if the value of the difference is equal to or greater than the fourth predetermined value ε4, the corrected expansion coefficient α′i-0 is calculated on the basis of the following expression:
• (1/α′i-0)=(1/α′(i−j)-0)+Δ4.

A method of driving an image display device, wherein

• the image display device includes
• (A) an image display panel in which P0×Q0 pixels in total of P0 pixels in a first direction and Q0 pixels in a second direction are arranged in a two-dimensional matrix, and
• (B) a signal processor,
• each pixel has a first subpixel displaying a first primary color, a second subpixel displaying a second primary color, a third subpixel displaying a third primary color, and a fourth subpixel displaying a fourth color, the method comprising:
• (1) in an i-th image display frame, in the signal processor:
• (a) obtaining a first subpixel output signal on the basis of at least a first subpixel input signal and a corrected expansion coefficient α′i-0, and outputting the first subpixel output signal to the first subpixel,
• (b) obtaining a second subpixel output signal on the basis of at least a second subpixel input signal and the corrected expansion coefficient α′i-0, and outputting the second subpixel output signal to the second subpixel,
• (c) obtaining a third subpixel output signal on the basis of at least a third subpixel input signal and the corrected expansion coefficient α′i-0, and outputting the third subpixel output signal to the third subpixel, and
• (d) obtaining a fourth subpixel output signal to a (p,q)th [where p=1, 2, ..., and P0, and q=1, 2, ..., and Q0 ] pixel when counting in the second direction on the basis of a fourth subpixel control second signal obtained from a first subpixel input signal, a second subpixel input signal, and a third subpixel input signal to the (p,q)th pixel and a fourth subpixel control first signal obtained from a first subpixel input signal, a second subpixel input signal, and a third subpixel input signal to an adjacent pixel adjacent to the (p,q)th pixel in the second direction, and outputting the fourth subpixel output signal to the fourth subpixel of the (p,q)th pixel;
• (2) obtaining in the signal processor or storing in the signal processor a maximum value Vmax(S) of luminosity with saturation S in an HSV color space enlarged by adding the fourth color as a variable;
• and
• (3) in the i-th image display frame, in the signal processor:
• (a) obtaining a saturation Si and a luminosity Vi(S) in a plurality of pixels on the basis of subpixel input signal values in the plurality of pixels,
• (b) obtaining an expansion coefficient αhd i-0 on the basis of at least one of the values of Vmax(S)/Vi(S) obtained in the plurality of pixels, and
• (c) determining the corrected expansion coefficient α′i-0 on the basis of a value obtained by
• (i) calculating a difference between (1) a first reciprocal of the expansion coefficient αi-0 obtained in the i-th image display frame and (2) a second reciprocal of a corrected expansion coefficient α′(i−j)−0 applied in advance in an (i−j)th image display frame (where j is a positive integer equal to or greater than 1),
• (ii) obtaining a correction value corresponding to the difference, and
• (iii) adding or subtracting the correction value to or from the second reciprocal,
• wherein,
• the saturation S and the luminosity V(S) are represented as follows:
• S=(Max−Min)/Max
• V(S)=Max
• where, Max is a maximum value among three subpixel input signal values including a first subpixel input signal value, a second subpixel input signal value, and a third subpixel input signal value to the pixel, and
• Min is a minimum value among the three subpixel input signal values including the first subpixel input signal value, the second subpixel input signal value, and the third subpixel input signal value to the pixel;
• (a) the correction value includes Δ1, Δ2, Δ3, and Δ4;
• (b) when Δ1>Δ2>0 and Δ4>Δ3 >0, a first predetermined value is ε1, a second predetermined value is ε2, a third predetermined value is ε3, a fourth predetermined value is ε4, ε1<ε2<0, and ε4>ε3>0;
• (c) if a value of the difference is smaller than the first predetermined value ε1, the corrected expansion coefficient α′i-0 is calculated on the basis of the following expression:
• (1/α′i-0)=(1/α′(i−j)-0)−Δ1;
• (d) if the value of the difference is equal to or greater than the first predetermined value ε1 and smaller than the second predetermined value ε2, the corrected expansion coefficient α′i-0 is calculated on the basis of the following expression:
• (1/α′i-0)=(1/α′(i−j)-0)−Δ2;
• (e) if the value of the difference is equal to or greater than the second predetermined value ε2 and smaller than the third predetermined value ε3, the corrected expansion coefficient α′i-0 is calculated on the basis of the following expression:
• (1/α′i-0)=(1/α′(i−j)-0);
• (f) if the value of the difference is equal to or greater than the third predetermined value ε3 and smaller than the fourth predetermined value ε4, the corrected expansion coefficient α′i-0 is calculated on the basis of the following expression:
• (1/α′i-0)=(1/α′(i−j)-0)+Δ3;
• and
• (g) if the value of the difference is equal to or greater than the fourth predetermined value ε4, the corrected expansion coefficient α′i-0 is calculated on the basis of the following expression:
• (1/α′i-0)=(1/α′(i−j)-0)+Δ4.

A method of driving an image display device, wherein

• the image display device includes
• (A) an image display panel in which P×Q pixel groups in total of P pixel groups in a first direction and Q pixel groups in a second direction are arranged in a two-dimensional matrix, and
• (B) a signal processor,
• each pixel group has a first pixel and a second pixel in the first direction,
• the first pixel has a first subpixel displaying a first primary color, a second subpixel displaying a second primary color, and a third subpixel displaying a third primary color,
• the second pixel has a first subpixel displaying the first primary color, a second subpixel displaying the second primary color, and a fourth subpixel displaying a fourth color,
• (1) in an i-th image display frame, in the signal processor:
• (a) obtaining a fourth subpixel output signal on the basis of a fourth subpixel control second signal obtained from a first subpixel input signal, a second subpixel input signal, and a third subpixel input signal to a (p,q)th [where p=1, 2, ..., and P and q=1, 2, ..., and Q] second pixel when counting in the second direction, a fourth subpixel control first signal obtained from a first subpixel input signal, a second subpixel input signal, and a third subpixel input signal to an adjacent pixel adjacent to the (p,q)th second pixel in the second direction, and a corrected expansion coefficient α′i-0, and outputting the fourth subpixel output signal to the fourth subpixel of the (p,q)th second pixel, and
• (b) obtaining a third subpixel output signal on the basis of at least a third subpixel input signal to the (p,q)th second pixel, a third subpixel input signal to a (p,q)th first pixel, and the corrected expansion coefficient α′i-0, and outputting the third subpixel output signal to the third subpixel of the (p,q)th first pixel;
• (2) obtaining in the signal processor or storing in the signal processor a maximum value Vmax(S) of luminosity with a saturation S in an HSV color space enlarged by adding the fourth color as a variable;
• and
• (3) in the i-th image display frame, in the signal processor:
• (a) obtaining a saturation Si and a luminosity Vi(S) in a plurality of pixels on the basis of subpixel input signal values in the plurality of pixels,
• (b) obtaining an expansion coefficient αi-0 on the basis of at least one of the values of Vmax(S)/Vi(S) obtained in the plurality of pixels, and
• (c) determining the corrected expansion coefficient α′i-0 on the basis of a value obtained by
• (i) calculating a difference between (1) a first reciprocal of the expansion coefficient αi-0 obtained in the i-th image display frame and (2) a second reciprocal of a corrected expansion coefficient α′(i−j)−0 applied in advance in an (i−j)th image display frame (where j is a positive integer equal to or greater than 1),
• (ii) obtaining a correction value corresponding to the difference, and
• (iii) adding or subtracting the correction value to or from the second reciprocal,
• wherein,
• the saturation S and the luminosity V(S) are represented as follows:
• S=(Max−Min)/Max
• V(S)=Max
• where, Max is a maximum value among three subpixel input signal values including a first subpixel input signal value, a second subpixel input signal value, and a third subpixel input signal value to the pixel, and
• Min is a minimum value among the three subpixel input signal values including the first subpixel input signal value, the second subpixel input signal value, and the third subpixel input signal value to the pixel;
• (a) the correction value includes Δ1, Δ2, Δ3, and Δ4;
• (b) when Δ1>Δ2>0 and Δ4>Δ3>0, a first predetermined value is ε1, a second predetermined value is ε2, a third predetermined value is ε3, a fourth predetermined value is ε4, ε1<ε2<0, and ε4>ε3>0;
• (c) if a value of the difference is smaller than the first predetermined value ε1, the corrected expansion coefficient α′i-0 is calculated on the basis of the following expression:
• (1/α′i-0)=(1/α′(i−j)-0)−Δ1;
• (d) if the value of the difference is equal to or greater than the first predetermined value ε1 and smaller than the second predetermined value ε2, the corrected expansion coefficient α′i-0 is calculated on the basis of the following expression:
• (1/α′i-0)=(1/α′(i−j)-0)−Δ2;
• (e) if the value of the difference is equal to or greater than the second predetermined value ε2 and smaller than the third predetermined value ε3, the corrected expansion coefficient α′i-0 is calculated on the basis of the following expression:
• (1/α′i-0)=(1/α′(i−j)-0);
• (f) if the value of the difference is equal to or greater than the third predetermined value ε3 and smaller than the fourth predetermined value ε4, the corrected expansion coefficient α′i-0 is calculated on the basis of the following expression:
• (1/α′i-0)=(1/α′(i−j)-0)+Δ3;
• and
• (g) if the value of the difference is equal to or greater than the fourth predetermined value ε4, the corrected expansion coefficient α′i-0 is calculated on the basis of the following expression:
• (1/α′i-0)=(1/α′(i−j)-0)+Δ4.