Key structure and keyboard

1. A key structure, comprising:

a base;

a light sensing module, disposed at the base;

a carrier, located above the base;

a magnetic member, disposed on the carrier;

a cap, adapted to be assembled to the carrier via a magnetic attracting force of the magnetic member or adapted to be detached from the carrier via overcoming the magnetic attracting force of the magnetic member; and

a scissor structure, connected between the base and the carrier, the carrier and the cap disposed thereon moving up and down relative to the base via the scissor structure,

wherein an orthogonal projection of the magnetic member on the base is not overlapped with an orthogonal projection of the light sensing module on the base.

2. The key structure as claimed in claim 1 , wherein after the light sensing module projects light on a sensing region of the cap along a path, the sensing region projects reflected light to the light sensing module along the path.

3. The key structure as claimed in claim 2 , wherein at least a part of the carrier is transparent and is located on the path, and the magnetic member is not located on the path.

4. The key structure as claimed in claim 2 , wherein the scissor structure is not located on the path.

5. The key structure as claimed in claim 4 , wherein the scissor structure comprises a first linking member and a second linking member pivotally connected to each other and pivotally connected to the base, the carrier is pivotally connected to the first linking member and the second linking member, and the second linking member has an avoidance space to allow the light or the reflected light to pass through.

6. The key structure as claimed in claim 5 , wherein orthogonal projections of the first linking member and the second linking member on the base form a closed contour, and an orthogonal projection of the avoidance space on the base belongs to a portion of the closed contour.

7. The key structure as claimed in claim 5 , wherein a material of the second linking member is metal, and a material of the first linking member is plastic.

8. The key structure as claimed in claim 2 , wherein the scissor structure is transparent, and a part of the scissor structure is located on the path.

9. The key structure as claimed in claim 8 , wherein the scissor structure comprises a first linking member and a second linking member pivotally connected to the base respectively, and a part of the first linking member and a part of the second linking member are transparent and are both located on the path.

10. The key structure as claimed in claim 9 , wherein in each of the first linking member and the second linking member, a transparent material is combined with and a non-transparent material, and a portion of the transparent material is located on the path.

11. The key structure as claimed in claim 2 , wherein the key structure is suitable for allowing replacement of different caps, and the different caps respectively have sensing regions exhibiting different optical properties.

12. The key structure as claimed in claim 11 , wherein the optical properties comprise a pattern or a color level.

13. The key structure as claimed in claim 2 , further comprising another magnetic member disposed at the cap and corresponding to the magnetic member located on the carrier, wherein a location of the another magnetic member at the cap is different from a location of the sensing region, and the another magnetic member is not located on the path.

14. A keyboard, comprising:

a base, having a thin film circuit;

a light sensing module, disposed at the base;

a carrier, located above the base;

a magnetic member, disposed on the carrier;

a cap; and

a scissor structure, connected between the base and the carrier, the carrier and the cap disposed thereon moving up and down relative to the base via the scissor structure; and

a control unit, electrically connected to the thin film circuit and the light sensing module,

wherein after the light sensing module projects light to the cap, the cap projects reflected light to the light sensing module,

wherein the cap is adapted to be assembled to the carrier via a magnetic attracting force of the magnetic member or adapted to be detached from the carrier via overcoming the magnetic attracting force of the magnetic member, so that the key structure is suitable for allowing replacement of different caps, and the control unit determines the cap according to the reflected light generated by the cap and received by the light sensing module.

15. The keyboard as claimed in claim 14 , wherein after the light sensing module projects light on a sensing region of the cap along a path, the sensing region projects reflected light to the light sensing module along the path, and the sensing regions of the different caps respectively have different patterns or color levels.

16. The keyboard as claimed in claim 15 , wherein at least a part of the carrier is located on the path and is transparent, and the magnetic member is not located on the path.

17. The keyboard as claimed in claim 15 , wherein the scissor structure comprises a first linking member and a second linking member pivotally connected to each other and pivotally connected to the base, the carrier is pivotally connected to the first linking member and the second linking member, and the first linking member has an avoidance space to allow the light or the reflected light to pass through.

18. The keyboard as claimed in claim 17 , wherein a material of the first linking member is metal, and a material of the second linking member is plastic.

19. The keyboard as claimed in claim 15 , wherein the scissor structure comprises a first linking member and a second linking member pivotally connected to the base respectively, and a part of the first linking member and a part of the second linking member are transparent and are both located on the path.

20. The keyboard as claimed in claim 19 , wherein a material of the first linking member and a material of the second linking member are plastic.