Display modules with direct-lit backlight units
A display may have a pixel array such as a liquid crystal pixel array. The pixel array may be illuminated with backlight illumination from a direct-lit backlight unit. The backlight unit may include an array of light-emitting diodes (LEDs) on a printed circuit board. The display may have a notch to accommodate an input-output component. Reflective layers may be included in the notch. The backlight may include a color conversion layer with a property that varies as a function of position. The light-emitting diodes may be covered by a slab of encapsulant with recesses in an upper surface.
1. An electronic device comprising:
a liquid crystal display panel;
a backlight unit that provides backlight for the liquid crystal display panel, wherein the backlight unit comprises:
an array of light-emitting diodes arranged in a light-emitting area, wherein the light-emitting area has a notch;
a bracket that overlaps the notch; and
foam that is interposed between the bracket and the liquid crystal display panel; and
an input-output component in the notch.
2. The electronic device defined in claim 1 , wherein the backlight unit further comprises:
an optical film over the array of light-emitting diodes.
3. The electronic device defined in claim 2 , further comprising:
a first adhesive layer that is interposed between the bracket and the optical film.
4. The electronic device defined in claim 3 , further comprising:
a second adhesive layer that is interposed between the bracket and the foam.
5. The electronic device defined in claim 4 , wherein the foam directly contacts the liquid crystal display panel.
6. The electronic device defined in claim 2 , wherein the bracket has a first portion that overlaps a second portion of the optical film on a first side of the notch and wherein the bracket has a third portion that overlaps a fourth portion of the optical film on a second, opposing side of the notch.
7. The electronic device defined in claim 2 , wherein the electronic device comprises a housing, wherein the liquid crystal display panel and the backlight unit are formed in the housing, wherein the electronic device includes a protrusion that extends from the housing, wherein the optical film has an opening, wherein the protrusion extends through the opening, wherein the bracket does not overlap the opening, and wherein the foam overlaps the opening.
8. The electronic device defined in claim 1 , wherein the bracket has an opening that accommodates the input-output component.
9. The electronic device defined in claim 8 , wherein the foam has an additional opening that accommodates the input-output component.
10. The electronic device defined in claim 1 , further comprising:
a reflective layer that is formed along a border of the light-emitting area at an interface between the light-emitting area and the notch.
11. The electronic device defined in claim 10 , wherein the notch has first and second opposing edges and a third edge that extends between the first and second edges and wherein the reflective layer extends along the first, second, and third edges.
12. The electronic device defined in claim 10 , wherein the backlight unit further comprises a plurality of optical films that is formed over the array of light-emitting diodes.
13. The electronic device defined in claim 12 , wherein the plurality of optical films has a first thickness and wherein the reflective layer has a second thickness that is greater than or equal to the first thickness.
14. The electronic device defined in claim 12 , wherein each optical film in the plurality of optical films has a respective edge that is adjacent to the reflective layer.
15. An electronic device comprising:
a liquid crystal display panel;
a backlight unit that provides backlight for the liquid crystal display panel, wherein the backlight unit comprises:
an array of light-emitting diodes arranged in a light-emitting area, wherein the light-emitting area has a notch;
a first reflective layer in the notch;
an optical film over the array of light-emitting diodes; and
a second reflective layer on the optical film, wherein the second reflective layer overlaps the first reflective layer; and
an input-output component in the notch.
16. The electronic device defined in claim 15 , wherein the optical film is a diffuser film.
17. The electronic device defined in claim 15 , wherein the electronic device comprises a housing, wherein the liquid crystal display panel and the backlight unit are formed in the housing, and wherein the electronic device includes a protrusion that extends from the housing.
18. The electronic device defined in claim 17 , wherein the first reflective layer has a first opening, wherein the optical film has a second opening, and wherein the protrusion extends through the first and second openings.