Directional backlights with light emitting element packages

A light emitting diode array for a directional display apparatus, comprising:

• a first array of light emitting diode packages, each being a light emitting diode package being arrayed linearly, the light emitting diode package comprising:
• a body of packaging material;
• at least one light generation element arranged to generate light in an emission band;
• and
• a protection diode;
• wherein the at least one light generation element is arranged in a first well in said body, and the protection diode is not arranged in the first well.

A directional backlight for a directional display apparatus,

• comprising:
• a light emitting diode array, comprising:
• a first array of light emitting diode packages, each being a light emitting diode package being arrayed linearly, the light emitting diode package comprising:
• a body of packaging material;
• at least one light generation element arranged to generate light in an emission band;
• and
• a protection diode;
• wherein the at least one light generation element is arranged in a first well in said body, and the protection diode is not arranged in the first well;
• and
• a waveguide comprising an input end arranged to receive input light from the light emitting diode array at respective input positions, first and second, opposed guide surfaces for guiding input light along the waveguide, and a reflective end for reflecting input light back through the waveguide, the second guide surface being arranged to deflect light after reflection from the reflective end as output light through the first guide surface, and the waveguide being arranged to direct the output light into optical windows in output directions that are distributed in a lateral direction in dependence on the input position of the input light.

A directional display apparatus comprising:

• a directional backlight, comprising:
• a light emitting diode array, comprising:
• a first array of light emitting diode packages, each being a light emitting diode package being arrayed linearly, the light emitting diode package comprising:
• a body of packaging material;
• at least one light generation element arranged to generate light in an emission band;
• and
• a protection diode;
• wherein the at least one light generation element is arranged in a first well in said body, and the protection diode is not arranged in the first well;
• and
• a waveguide comprising an input end arranged to receive input light from the light emitting diode array at respective input positions, first and second, opposed guide surfaces for guiding input light along the waveguide, and a reflective end for reflecting input light back through the waveguide, the second guide surface being arranged to deflect light after reflection from the reflective end as output light through the first guide surface, and the waveguide being arranged to direct the output light into optical windows in output directions that are distributed in a lateral direction in dependence on the input position of the input light;
• and
• a transmissive spatial light modulator arranged to receive the output light from the first guide surface of the waveguide and to modulate it to display an image.

A method of forming an array of light emitting diode packages, the method using a linear holder comprising a slot capable of receiving a line of light emitting diode packages, the method comprising:

• disposing the light emitting diode packages in the slot of the holder;
• aligning the linear holder with an array substrate;
• providing solder and thermal connection between the array of light emitting diode packages and the array substrate;
• and
• removing the linear holder.

A directional backlight for a directional display apparatus, comprising:

• an array of light sources;
• a waveguide comprising an input end arranged to receive input light from the light emitting diode array at respective input positions, and first and second, opposed guide surfaces for guiding input light along the waveguide, the second guide surface being arranged to deflect light as output light through the first guide surface, and the waveguide being arranged to direct the output light into optical windows in output directions that are distributed in a lateral direction in dependence on the input position of the input light;
• and
• an input end, front light shielding arrangement for shielding the light sources, comprising:
• an extraction film strip extending across the first guide surface adjacent the input end, the extraction film strip comprising an array of alternating first and second facets, the first facets being oriented to receive light that leaks from the first guide surface while being guided along the waveguide, and the second facets being arranged to deflect the received light towards the normal to the first guide surface;
• and
• a mask arranged outside the extraction film strip arranged to absorb the received light after deflection by the second facets.

A directional display apparatus comprising:

• a directional backlight, comprising:
• a waveguide comprising an input end arranged to receive input light from the light emitting diode array at respective input positions, and first and second, opposed guide surfaces for guiding input light along the waveguide, the second guide surface being arranged to deflect light as output light through the first guide surface, and the waveguide being arranged to direct the output light into optical windows in output directions that are distributed in a lateral direction in dependence on the input position of the input light;
• and
• an input end, front light shielding arrangement for shielding the light sources, comprising:
• an extraction film strip extending across the first guide surface adjacent the input end, the extraction film strip comprising an array of alternating first and second facets, the first facets being oriented to receive light that leaks from the first guide surface while being guided along the waveguide, and the second facets being arranged to deflect the received light towards the normal to the first guide surface;
• and
• a mask arranged outside the extraction film strip arranged to absorb the received light after deflection by the second facets;
• and
• a transmissive spatial light modulator arranged to receive the output light from the first guide surface of the waveguide and to modulate it to display an image.