Fabrication method and fabrication apparatus for backlight source, display device, and a display system

A method for fabricating a backlight source, comprising:

• determining an n-step MacAdam ellipse in a uniform chromaticity diagram, n being an integer smaller than or equal to 3;
• and
• fabricating the backlight source according to chromaticity coordinates within the n-step MacAdam ellipse to cause chromaticity coordinates of light emitted from different light-emitting diodes of the backlight source to be within the n-step MacAdam ellipse,
• wherein determining the n-step MacAdam ellipse includes:
• determining a target color temperature of a display device including the backlight source;
• determining an intersection of an isothermal line segment of the target color temperature and a Planckian locus in the uniform chromaticity diagram;
• and
• determining the n-step MacAdam ellipse according to the isothermal line segment and the intersection, the intersection being within the n-step MacAdam ellipse, and two endpoints of the isothermal line segment being on the n-step MacAdam ellipse, and
• wherein determining the n-step MacAdam ellipse according to the isothermal line segment and the intersection includes:
• determining at least one initial ellipse according to the isothermal line segment and the intersection, each of the at least one initial ellipse having the intersection as a center point, and the two endpoints of the isothermal line segment being on each of the at least one initial ellipse;
• matching the at least one initial ellipse with an m-step MacAdam ellipse in the uniform chromaticity diagram to determine, from the at least one initial ellipse, a largest initial ellipse containing the m-step MacAdam ellipse, wherein n≤m≤7;
• determining a chromaticity-region quadrilateral according to the largest initial ellipse, the two endpoints of the isothermal line segment forming a first vertex and a second vertex of the chromaticity-region quadrilateral, respectively, a point on the largest initial ellipse corresponding to a minimum abscissa of the largest initial ellipse in the uniform chromaticity diagram forming a third vertex of the chromaticity-region quadrilateral, and a point on the largest initial ellipse corresponding to a maximum abscissa of the largest initial ellipse in the uniform chromaticity diagram forming a fourth vertex of the chromaticity-region quadrilateral;
• and
• determining the n-step MacAdam ellipse in the chromaticity-region quadrilateral.