Solid state lamp using light emitting strips
In one embodiment, an LED lamp has a generally bulb shape. The LEDs are low power types and are encapsulated in thin, narrow, flexible strips. The LEDs are connected in series in the strips to drop a desired voltage. The strips are affixed to the outer surface of a bulb form to provide structure to the lamp. The strips are connected in parallel to a power supply, which may be housed in the lamp. Since many low power LEDs are used and are spread out over a large surface area, there is no need for a large metal heat sink. Further, the light emission is similar to that of an incandescent bulb. In other embodiment, there is no bulb form and the strips are bendable to have a variety of shapes. In another embodiment, a light sheet is bent to provide 360 degrees of light emission. Many other embodiments are described.
1. A solid state lamp comprising:
multiple strips, each of the strips comprising a substrate extending from a first end to a second end opposite the first end, the substrate of each strip being individually separate and distinct from the substrate of any other of the multiple strips, and each strip comprising one or more light emitting diodes (LEDs) disposed on the respective substrate configured to emit light during operation, wherein the respective substrate of each strip transmits at least some of the light emitted by the LEDs;
a support structure comprising a wire frame having a first portion and a second portion different from the first portion, the multiple strips being separately attached to the support structure, wherein the first end of each strip is attached to the first portion of the wire frame and the second end of each strip is attached to the second portion of the wire frame; and
a connector affixed to the support structure and configured to electrically connect the support structure to an external power source.
2. The solid state lamp of claim 1 , wherein the one or more strips are shaped to mimic the appearance of filaments in an incandescent light bulb during operation.
3. The solid state lamp of claim 1 , wherein each strip is configured to emit light around an axis of the strip.
4. The solid state lamp of claim 1 , wherein each of the one or more strips further comprises a phosphor coating covering the one or more LEDs and the one or more LEDs are configured, during operation, to emit light towards the phosphor and the phosphor is configured to convert light received from the one or more LEDs into converted light.
5. The solid state lamp of claim 1 , wherein the one or more LED strips are electrically connected in parallel.
6. The solid state lamp of claim 1 , wherein the support structure comprises a transparent material.
7. The solid state lamp of claim 1 , wherein the one or more strips are electrically connected in series.
8. The solid state lamp of claim 1 , wherein the one or more strips extend along a straight line from the first portion of the support structure to the second portion of the support structure.
9. The solid state lamp of claim 1 , wherein the connector comprises a screw socket connector or bayonet socket connector.
10. The solid state lamp of claim 1 , wherein the connector is an Edison-type connector.
11. The solid state lamp of claim 1 , wherein the connector is configured for connection to a socket by rotation about a connector axis, and the first and second electrical contacts of the one or more strips connect to the support structure at different positions along the connector axis.
12. The solid state lamp of claim 1 , wherein the LEDs are LED dies.
13. The solid state lamp of claim 12 , wherein each strip comprises transparent electrodes electrically connecting LED dies on the strip.
14. The solid state lamp of claim 12 , wherein sides of the LED dies are encapsulated by phosphor infused in a binder material.
15. The solid state lamp of claim 14 , wherein the binder material is a silicone.
16. The solid state lamp of claim 12 , wherein the LED dies are disposed on a single side of the substrate.
17. The solid state lamp of claim 12 , wherein the LED dies are disposed in a single row on the substrate.
18. The solid state lamp of claim 12 , wherein the LED dies are encapsulated in the strip.
19. The solid state lamp of claim 18 , wherein each strip comprises a layer of material extending over multiple of the LED dies.
20. The solid state lamp of claim 1 , wherein at least some of the strips are curved.
21. The solid state lamp of claim 1 , wherein the connector defines a lamp axis about which the lamp is rotated when installing the lamp in a conventional light socket, and at least a portion of at least some of the strips extend along the lamp axis non-parallel to the lamp axis.
22. The solid state lamp of claim 21 , wherein at least a portion of at least some of the strips extend along the lamp axis non-parallel to each other.
23. The solid state lamp of claim 1 , wherein each strip comprises an electrical contact at the first end of the strip and another electrical contact at the opposite end of the strip, the LEDs of each strip being electrically connected with the electrical contacts.
24. The solid state lamp of claim 23 , wherein the support structure is configured to provide electrical power to the strips and is electrically connected to the strips at the electrical contacts at the two ends of the strips.