Reflective display pixel

A reflective display pixel for modulating a return of incident visible light in specified wavelength bands, comprising:

• a stack of cells each to selectively return light in a corresponding at least one of the specified wavelength bands, wherein a first of the cells comprises a fluid containing:
• a light absorbing medium to absorb the incident visible light in the at least one specified wavelength band for the first cell, and being substantially transparent to at least a portion of the incident visible light in any of the specified wavelength bands for one or more cells lower in the stack;
• a light returning medium to selectively return at least a portion of the incident visible light within the at least one specified wavelength band for the first cell, and being substantially transparent to at least a portion of the incident visible light in any of the specified wavelength bands for the one or more cells lower in the stack, wherein the light returning medium includes a plurality of light returning particles selected from the group consisting of:
• Bragg scattering particles comprising a multilayer stack of dielectric layers with different refractive indices;
• plasmonic particles;
• and
• luminescent particles capable of selectively emitting at least a portion of light within the at least one specified wavelength band for the first cell;
• and
• where at least one of the light absorbing medium and the light returning medium is capable of controllable movement between positions within the first cell to adjust an amount of the incident visible light returned within the at least one specified wavelength band for the first cell.

A reflective display pixel for modulating a return of incident visible light in specified wavelength bands, comprising:

• a stack of cells each to selectively return light in a corresponding at least one of the specified wavelength bands, wherein a first of the cells comprises a fluid containing:
• a light absorbing medium to absorb the incident visible light in the at least one specified wavelength band for the first cell, and being substantially transparent to at least a portion of the incident visible light in any of the specified wavelength bands for one or more cells lower in the stack, wherein the light absorbing medium includes a plurality of light absorbing particles, the light absorbing particles capable of selectively absorbing the incident visible light in at least a portion of the at least one specified wavelength band for the first cell;
• a light returning medium to selectively return at least a portion of the incident visible light within the at least one specified wavelength band for the first cell, and being substantially transparent to at least a portion of the incident visible light in any of the specified wavelength bands for the one or more cells lower in the stack;
• and
• where at least one of the light absorbing medium and the light returning medium is capable of controllable movement between positions within the first cell to adjust an amount of the incident visible light returned within the at least one specified wavelength band for the first cell.

A reflective display pixel for modulating a return of incident visible light, comprising:

• a stack of cells, wherein a first of the cells comprises a fluid containing:
• a light absorbing medium to absorb the incident visible light in at least one specified wavelength band for the first cell, and being substantially transparent to at least a portion of the incident visible light in any of specified wavelength bands for one or more cells lower in the stack;
• a light returning medium to selectively return at least a portion of the incident visible light outside the at least one specified wavelength band for the first cell, and being substantially transparent to at least a portion of the incident visible light in any of the specified wavelength bands for the one or more cells lower in the stack;
• and
• where at least one of the light absorbing medium and the light returning medium is controllable to move up and down between positions within the fluid to adjust an amount of the incident visible light returned for the first cell, the positions including a first position closer to a viewing surface of the first cell, and a second position farther away from the viewing surface of the first cell.