Lighting systems with removable illumination modules

1. A lighting system comprising:

a lightsheet comprising:

a substrate;

one or more first electrical contacts disposed on the substrate and electrically connected to each other;

one or more second electrical contacts disposed on the substrate and electrically connected to each other, wherein the one or more first electrical contacts are electrically isolated from the one or more second electrical contacts; and

a plurality of illumination modules disposed on the substrate and electrically connected to each other, each illumination module comprising (i) one or more electrically connected light-emitting elements, (ii) a first power conductor, and (iii) a second power conductor electrically isolated from the first power conductor, wherein the one or more light-emitting elements are electrically connected between and energizable by the first and second power conductors,

wherein (i) the first power conductors of the illumination modules are electrically connected to the one or more first electrical contacts, (ii) the second power conductors of the illumination modules are electrically connected to the one or more second electrical contacts, (iii) the illumination modules are collectively energizable via application of power to a first electrical contact and a second electrical contact, and (iv) the first and second power conductors of the illumination modules are electrically connected to enable energization of all remaining illumination modules upon removal of any illumination module from the lightsheet.

2. The lighting system of claim 1 , wherein:

the first and second power conductors of each illumination module form an independent path electrically connected to at least one first electrical contact and at least one second electrical contact; and

removal of any illumination module does not sever the independent path formed by the first and second power conductors of any other illumination module.

3. The lighting system of claim 1 , further comprising one or more control elements configured to control current to at least one of the illumination modules.

4. The lighting system of claim 3 , wherein (i) the one or more control elements comprise a plurality of control elements, and (ii) each illumination module has a different control element electrically coupled thereto.

5. The lighting system of claim 1 , wherein at least one illumination module comprises one or more connectors for mechanical and electrical connection to an adjoining illumination module.

6. The lighting system of claim 5 , wherein at least one of the connectors comprises a snap connector.

7. The lighting system of claim 1 , wherein the light-emitting elements of at least one illumination module comprise light-emitting diodes.

8. The lighting system of claim 1 , wherein the one or more light-emitting elements of at least one illumination module comprise a plurality of light-emitting elements that are electrically connected in series.

9. The lighting system of claim 1 , wherein:

each illumination module comprises a plurality of electrically connected illumination units; and

each illumination unit comprises (i) one or more electrically connected light-emitting elements, and (ii) a bypass element (a) electrically connected across the first and second power conductors and (b) configured to transition from a high-impedance state to a low-impedance state and thereby complete a circuit between the first and second power conductors upon removal of the one or more light-emitting elements of the illumination unit from the lightsheet, whereby energization of unremoved light-emitting elements within the illumination module is maintained.

10. The lighting system of claim 9 , wherein at least one of the bypass elements comprises at least one of a switch, a relay, a Zener diode, or a circuit comprising at least one transistor and at least one resistor.

11. The lighting system of claim 9 , wherein at least one illumination module further comprises a second illumination unit comprising one or more electrically connected light-emitting elements without a bypass element associated therewith.

12. The lighting system of claim 11 , further comprising a power supply electrically connected to at least one of the first electrical contacts and at least one of the second electrical contacts, wherein (i) the at least one illumination module extends from a proximal end proximate the power supply to a distal end away from the power supply, and (ii) the second illumination unit is disposed at the proximal end.

13. The lighting system of claim 9 , wherein, for at least one illumination module, at least one illumination unit further comprises (i) a voltage-drop element and (ii) a shunt configured to (a) prevent voltage drop across the voltage-drop element when the one or more light-emitting elements of the illumination unit are present on the lightsheet, and (b) upon removal of the one or more light-emitting elements of the illumination unit, cause a voltage drop across the voltage-drop element.

14. The lighting system of claim 13 , wherein the shunt is configured to be at least partially removed upon removal of the one or more light-emitting elements of the illumination unit, thereby causing the voltage drop across the voltage-drop element.

15. The lighting system of claim 13 , wherein the voltage drop across the voltage-drop element is approximately equal to a voltage drop across the one or more light-emitting elements of the illumination unit when the one or more light-emitting elements of the illumination unit are present on the lightsheet.

16. The lighting system of claim 13 , wherein the voltage-drop element comprises a resistor.

17. The lighting system of claim 9 , wherein, for each illumination unit, (i) the one or more electrically connected light-emitting elements are electrically connected in series with the first power conductor, (ii) the bypass element has first and second electrical connection points, (iii) the first electrical connection point of the bypass element is electrically connected between (a) the one or more light-emitting elements of the illumination unit and (b) the one or more light-emitting elements of an adjoining illumination unit, and (iv) the second electrical connection point of the bypass element is electrically connected to the second power conductor.

18. The lighting system of claim 9 , wherein at least one bypass element has a resistance of at least 10 6 ohms in the high-impedance state.

19. The lighting system of claim 9 , wherein at least one bypass element has a resistance no greater than 10 3 ohms in the low-impedance state.

20. The lighting system of claim 1 , further comprising a second lightsheet electrically connected to the lightsheet.

21. The lighting system of claim 1 , further comprising an optic disposed over at least a portion of the lightsheet.

22. The lighting system of claim 21 , wherein the optic comprises at least one of a lens, a diffuser, a refractive optic, a reflective optic, a Fresnel optic, a fabric, a translucent material panel, a graphic panel, or a membrane.

23. The lighting system of claim 1 , wherein an optical characteristic of one or more of the illumination units is different from a corresponding optical characteristic of one or more other illumination units.

24. The lighting system of claim 23 , wherein the optical characteristic comprises at least one of correlated color temperature, color rendering index, R9, spectral power distribution, or spatial light intensity distribution.

25. The lighting system of claim 1 , wherein the substrate is flexible.

26. The lighting system of claim 1 , wherein along each illumination unit, a pitch at which the light-emitting elements are spaced is substantially constant.

27. The lighting system of claim 1 , wherein the lightsheet comprises one or more connectors for mechanical and/or electrical connection to an adjoining lightsheet.

28. The lighting system of claim 1 , further comprising:

a first snap connector electrically connected to the one or more first electrical contacts;

a second snap connector electrically connected to the one or more second electrical contacts; and

a second lightsheet comprising:

a second substrate,

third and fourth power conductors disposed on the second substrate,

a plurality of second light-emitting elements disposed on the second substrate and electrically connected to the third and fourth power conductors,

a third snap connector electrically connected to the third power conductor, and

a fourth snap connector electrically connected to the fourth power conductor,

wherein (i) the first snap connector is configured for connection to the third snap connector, thereby electrically coupling the one or more first electrical contacts to the third power conductor, (ii) the second snap connector is configured for connection to the fourth snap connector, thereby electrically coupling the one or more second electrical contacts to the fourth power conductor.