Light source

1. A light bulb comprising:

(a) a substrate having a light emitting member provided thereon, the substrate has an insertion end, a longitudinally opposed outer end and a body portion extending longitudinally between the insertion end and the outer end, the body portion has first and second longitudinally extending sides; and,

(b) a main body in which the substrate is removably received, the main body comprising a heat sink and electrical contact members, the main body has a recess in which the insertion end of the substrate is slideably receivable, and the heat sink has an opening in which the body portion of the substrate is positioned when the insertion end of the substrate is inserted into the recess, the opening comprising a first sidewall portion and an opposed second sidewall portion,

wherein the substrate is moveable from a fully inserted in use position in which the substrate is secured in position in the main body and a withdrawn position in which the substrate has been withdrawn from the light bulb and the substrate is slideably insertable into the in use position, and

wherein, when the substrate is in the fully inserted in use position, the first longitudinally extending side faces the first sidewall portion and is in thermal communication with the first sidewall portion and the second longitudinally extending side faces the second sidewall portion and is in thermal communication with the second sidewall portion, and

wherein the electrical contact members comprise an electrically conductive body portion that is mounted to the main body and the electrically conductive body portion mechanically secures the substrate in position in the fully inserted in use position.

2. The light bulb of claim 1 wherein the electrically conductive body portion comprises a biasing member which engages the substrate.

3. The light bulb of claim 1 wherein the electrical contact members comprises a first electrical contact member which contacts a first side of the substrate and a second electrical contact member that contacts an opposed side of the substrate.

4. The light bulb of claim 1 wherein the electrical contact members comprise first and second electrical contact members, the first electrical contact member exerts a force in a first direction on the substrate and the second electrical contact member exerts a force in a direction opposite to the first direction on the substrate.

5. The light bulb of claim 1 wherein the insertion end is a lead end when the substrate is inserted into the main body and the electrical contact members comprise a cam surface engageable by the insertion end upon insertion of the substrate into the main body.

6. The light bulb of claim 1 wherein at least a portion of the electrical contact members are provided in the recess.

7. The light bulb of claim 6 wherein the recess is provided in the heat sink.

8. The light bulb of claim 6 wherein the electrical contact members comprise a guide surface which guides the substrate into the recess.

9. The light bulb of claim 1 wherein the heat sink has a recess in which the substrate is slideably receivable.

10. The light bulb of claim 1 wherein the electrical contact members thermally connect the substrate with the heat sink.

11. The light bulb of claim 10 wherein the substrate is made of a non-conductive material and is coated with a thermal conducting layer.

12. The light bulb of claim 1 wherein the substrate comprises a printed circuit board.

13. The light bulb of claim 1 wherein the main body comprises a housing having a base connectable to a source of current, a diffuser and a slot in which the substrate is slideably receivable.

14. The light bulb of claim 1 wherein the body portion has first and second longitudinally extending surfaces on different sides of the body portion and a light emitting member is provided on each of the first and second longitudinally extending surfaces.

15. The light bulb of claim 1 wherein the outer portion of the heat sink has fins that extend generally axially.

16. The light bulb of claim 1 wherein the substrate is insertable into the main body in a direction that is generally transverse to the axial direction.

17. The light bulb of claim 16 wherein the outer portion of the heat sink has fins that extend generally axially.

18. The light bulb of claim 1 , wherein the main body further comprises an insertion end that is electrically connectable to a light housing, an outer light emitting end that is spaced from the insertion end in an axial direction, and a mid-portion located between the insertion end and the outer light emitting end, the mid-portion having an exterior surface which comprises an outer portion of the heat sink.

19. The light bulb of claim 18 wherein the substrate is insertable into the main body in a direction that is generally transverse to the axial direction.

20. A light bulb comprising:

(a) a substrate having a light emitting member provided thereon, the substrate has an insertion end, a longitudinally opposed outer end and a body portion extending longitudinally between the insertion end and the outer end, the body portion has first and second longitudinally extending sides; and,

(b) a main body comprising a heat sink and having a recess in which the insertion end of the substrate is slideably receivable, the heat sink has an opening comprising a first sidewall portion and an opposed second sidewall portion,

wherein the substrate is moveable from a fully inserted in use position in which the substrate is secured in position in the main body and a withdrawn position in which the substrate has been withdrawn from the light bulb and the substrate is slideably insertable into the in use position, and

wherein, when the substrate is in the fully inserted in use position, the first longitudinally extending side faces the first sidewall portion and is in thermal communication with the first sidewall portion and the second longitudinally extending side faces the second sidewall portion and is in thermal communication with the second sidewall portion.

21. The light bulb of claim 20 wherein the substrate is insertable into the main body in a direction that is generally transverse to the axial direction.