Joystick

1. A joystick, comprising:

a casing, having a hole:

a stick body movably disposed on the casing via the hole, the stick body comprising:

a pressing portion;

an indication portion connected to the pressing portion and inserting into the hole, a sunken structure being formed on a bottom of the indication portion; and

an identification pattern disposed on an inner surface of the sunken structure; and

an optical sensor disposed inside the casing and facing the sunken structure, and adapted to analyze a movement of the identification pattern to identify a control status of the stick body.

2. The joystick of claim 1 , wherein the indication portion comprises a cubic member disposed inside the casing in a movable manner.

3. The joystick of claim 1 , wherein the indication portion comprises a spherical member disposed inside the casing in a rotatable manner.

4. The joystick of claim 3 , wherein the casing further has an accommodating structure where inside the spherical member is disposed in a tight manner.

5. The joystick of claim 1 , wherein the indication portion comprises a half-spherical member disposed inside the casing in a shiftable and rotatable manner.

6. The joystick of claim 5 , wherein the indication portion further comprises a supporting member surrounding an edge of the half-spherical member, and adapted to detachably abutting against an inner wall of the casing.

7. The joystick of claim 6 , wherein the casing further has a constraining portion disposed on the inner wall of the casing to constrain a movement of the supporting member relative to the casing.

8. The joystick of claim 1 , wherein the indication portion is divided into a first section and a second section connected to each other, a diameter of the first section is smaller than an aperture of the hole and a diameter of the second section is greater than the aperture.

9. The joystick of claim 1 , wherein the casing further has a blocking portion disposed on a bore wall of the hole and adapted to prevent the stick body from being separated from the hole.

10. The joystick of claim 9 , wherein a rotation angle of the stick body relative to the casing is defined by a dimension of the blocking portion.

11. The joystick of claim 1 , wherein the inner surface of the sunken structure is one of a flat surface and an arc surface.

12. The joystick of claim 11 , wherein the arc surface is a concave or a convex.

13. The joystick of claim 1 , wherein the identification pattern comprises one dot or a plurality of dots.

14. The joystick of claim 13 , wherein the dot has a symmetric form or an asymmetric form.

15. The joystick of claim 13 , wherein the plurality of dots is arranged in symmetry or in asymmetry.

16. The joystick of claim 1 , further comprising:

a resilient component disposed between the pressing portion and an upper surface of the casing, and adapted to recover the pressing portion to an initial position via a resilient recovering force of the resilient component.

17. The joystick of claim 1 , further comprising:

a resilient component disposed between the indication portion and a bottom surface of the casing, and used to recover the pressing portion to an initial position via a resilient recovering force of the resilient component.

18. The joystick of claim 17 , wherein the indication portion is disposed inside the casing in a separable manner, and the resilient component pushes the indication portion abutting against the casing.

19. The joystick of claim 1 , further comprising:

a light source disposed inside the casing and adapted to emit an optical illumination signal toward the identification pattern.

20. The joystick of claim 1 , wherein the identification pattern is located inside a predefined region within a field of view of the optical sensor.