Input device including a layer of particles

• US 20050237309A1
• Filed: 04/26/2004
• Published: 10/27/2005
• Est. Priority Date: 04/26/2004
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Sharma, Manish
• Granted Patent: US 7,532,203 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 3/046 by electromagnetic means
• CPC Class Codes: G09G 2320/029 by monitoring one or more pixels in the display panel, e.g. by monitoring a fixed reference pixel
• CPC Class Codes: G09G 3/3486 using light modulating elements actuated by a magnetic field

Abstract

An input device includes a plurality of MRAM cells and a layer of particles. An MRAM cell in the input device includes a sense layer having a magnetic orientation. At least one particle of the layer of particles is located near the MRAM cell such that the particle affects the magnetic orientation of the sense layer of the MRAM cell.

Claims

1. An input device, comprising:

a plurality of MRAM cells, each including a sense layer having a magnetic orientation; and

a layer of particles including at least one particle located near at least one cell of the plurality of MRAM cells,

wherein the at least one particle affects an orientation of the magnetic field of the sense layer of the at least one cell.

2. The input device of claim 1, wherein the at least one particle emits a magnetic field with a changeable orientation that affects the orientation of the magnetic field of the sense layer of the at least one cell.

3. The input device of claim 2, wherein each of the plurality of cells further comprise:

a barrier layer provided between the sense layer and a reference layer with a fixed magnetic field orientation creating a magnetic tunnel junction between the sense layer and the reference layer.

4. The input device of claim 3, wherein a resistance of the at least one MRAM cell changes in response to the orientation of the magnetic field of the at least one particle changing.

5. The input device of claim 4, further comprising a control unit operable to measure the resistance of the at least one MRAM cell to determine a state of the at least one particle.

6. The input device of claim 1, wherein the at least one MRAM cell comprises a nonvolatile storage cell storing a state of the at least one particle, the state being associated with the orientation of the magnetic field of the at least one particle.

7. The input device of claim 1, wherein the particles comprise magnetic particles.

8. The input device of claim 7, further comprising a magnetic field generating device for altering an orientation of a magnetic field of one or more of the magnetic particles when placed in proximity to the layer of particles.

9. The input device of claim 8, wherein the magnetic field generating device comprises:

an electromagnet having a polarity; and

a switch for controlling the polarity of the electromagnet operable to apply a magnetic field to the one or more particles.

10. The input device of claim 7, wherein the magnetic particles have an electrostatic charge.

11. The input device of claim 10, further comprising an electrostatic field generating device for altering an orientation of a magnetic field of one or more of the magnetic particles when placed in proximity to the layer of particles.

12. The input device of claim 1, further comprising an integrated display having a plurality of pixels and wherein at least one of the pixels is directly controlled by at least one of the plurality of MRAM cells.

13. The input device of claim 1, further comprising an integrated display having a plurality of pixels and wherein at least one of the pixels is indirectly controlled by at least one of the plurality of MRAM cells.

14. The input device of claim 1, wherein the layer of particles comprise non-volatile data storage.

15. The input device of claim 14, further comprising an initializer to apply a voltage to the layer of particles to erase data stored in the layer of particles.

16. A non-volatile input memory device, comprising;

a layer of particles operable to non-volatility store input information; and

a plurality of MRAM cells near the layer of particles,

wherein at least one cell of the plurality of MRAM cells reads the input information stored in at least a portion of the layer of particles.

17. The non-volatile input memory device of claim 16, wherein at least one of the plurality of MRAM cells includes a barrier layer having a magnetic tunnel junction.

18. The non-volatile input memory device of claim 16, wherein at least one of the particles has an electrostatic charge.

19. The non-volatile input memory device of claim 16, wherein at least one of the particles has a magnetic field.

20. The non-volatile input memory device of claim 16, wherein the at least a portion of the layer of particles is operable to receive the input information from a user input device.

21. The non-volatile input memory device of claim 16, further comprising a display having a plurality of pixels and wherein at lease one of the pixels is directly controlled by the input information stored in the layer of particles.

22. The non-volatile input memory device of claim 16, further comprising a display having a plurality of pixels and wherein at least of the pixels is indirectly controlled by the input information stored in the layer of particles.

23. The non-volatile input Memory device of claim 16, further comprising an initializer operable to erase the input information stored in the layer of particles.

24. The non-volatile input memory device of claim 16, wherein the at least one of the plurality of MRAM cells includes a reference layer having a pinned magnetic orientation, a barrier layer adjacent to the reference layer, and a sense layer adjacent to the barrier layer, the sense layer having a changeable magnetic orientation.

25. The non-volatile input memory device of claim 24, wherein at least one of the particles changes the magnetic orientation of the sense layer.

26. A method of operating an input device having a layer of particles, each particle having a magnetic orientation, the layer of particles overlaying a plurality of MRAM cells, the method comprising:

changing the magnetic orientation of at least one particle in the layer of particles;

providing a voltage to at least one of the plurality of MRAM cells wherein the at least one MRAM cell is substantially underlying the at least one particle; and

detecting a change in resistance of the at least one cell.

27. The method according to claim 26, wherein the resistance changes in response to the change of the magnetic orientation of the at least one particle.

28. The method according to claim 26, further comprising activating a pixel of a display in response to the detection of the change in resistance of the at least one MRAM cell.

29. The method according to claim 26, further comprising:

receiving a magnetic field at the layer of particles, wherein the magnetic field is generated by a magnetic field generator and changes the magnetic orientation of the at least one particle.

30. The method according to claim 26, further comprising initializing the apparatus by aligning the magnetic orientation of each particle of the layer of particles in substantially one direction.

31. The method according to claim 30, wherein initializing includes providing a voltage to the layer of particles.

32. The method according to claim 30, wherein initializing includes providing an external magnetic field to the layer of particles.

33. The method according to claim 26, wherein the MRAM cell includes a sense layer having a changeable magnetic orientation and wherein the step of changing the magnetic orientation of at least one particle in the layer of particles causes the magnetic orientation of the sense layer to change.

34. The method according to claim 26, further comprising:

receiving an electrostatic field at the layer of particles, wherein the electrostatic field is generated by an electrostatic field generator and changes the magnetic orientation of the at least one particle.

35. An apparatus having a layer of particles, each particle having a magnetic orientation, the layer of particles overlaying a plurality of MRAM cells, the apparatus comprising:

means for changing the magnetic orientation of at least one particle in the layer of particles;

means for providing a voltage to at least one of the MRAM cells; and

means for detecting a change in resistance of the at least one of the MRAM cells located under the at least one particle, the change in resistance in response to the change of the magnetic orientation of the at least one particle.

36. The apparatus of claim 35, further comprising means for activating a pixel of a display in response to the detection of the change in resistance of one of the MRAM cells.

37. The apparatus of claim 35, further comprising means for aligning the magnetic orientation of each particle in the layer of particles in substantially one direction.

38. The apparatus of claim 35, wherein the at least one of the MRAM cells further comprises sense means responsive to the magnetic orientation of at least one particle in the layer of particles.