Factory and user calibration of haptic systems

1. A method for performing a calibration process in an electronic device, comprising:

detecting a stationary state of an electronic device;

(a) generating a drive signal from a haptic driver in a sensorless haptic system disposed in the electronic device;

(b) transmitting the drive signal to an actuator in the sensorless haptic system;

(c) detecting a back Electromotive Force (bEMF) signal from the actuator in the sensorless haptic system;

(d) analyzing an output waveform from the bEMF signal, wherein the output waveform from the bEMF signal comprises a sinusoidal waveform;

(e) comparing the output waveform with a target sinusoidal waveform set for bEMF signal;

(f) adjusting a scale of the drive signal generated from the haptic driver to calibrate the sensorless haptic system;

repeatedly performing (a) to (f) until the output waveform matched the target sinusoidal waveform set to complete the calibration process; and

storing the adjusted scale of the haptic output in a memory of the electronic device as a new reference standard for future calibration.

2. The method of claim 1 , wherein adjusting the scale of the drive signal further comprises:

adjusting an amplitude of the output waveform.

3. The method of claim 2 , further comprising:

altering a haptic output generated from the actuator in the sensorless haptic system.

4. The method of claim 1 , further comprising:

receiving an input signal applied to the sensorless haptic system to generate the drive signal.

5. The method of claim 4 , wherein the input signal is applied by a user.

6. The method of claim 4 , wherein the input signal is applied by a working staff in a factory.

7. The method of claim 1 , wherein the drive signal is in direct communication with the actuator disposed in close proximity to the haptic driver in the sensorless haptic system.

8. The method of claim 1 , wherein the drive signal is a voltage signal or a current signal.

9. The method of claim 1 , wherein the electronic device is a wearable device or a portable device.

10. A method for performing a calibration process in an electronic device, comprising:

(a) tracking a haptic output from an actuator in a sensorless haptic system by generating a drive signal to the actuator to detect a back Electromotive Force (bEMF) signal comprising a sinusoidal waveform from the actuator, wherein the sensorless haptic system is embedded in a wearable device or portable device;

(b) comparing the output waveform with a target sinusoidal waveform set for bEMF signal;

(c) adjusting a voltage or current applied to a haptic driver in the sensorless haptic system in response to the sinusoidal waveform from the tracked haptic output;

(d) adjusting a scale of the haptic output to calibrate the sensorless haptic system;

repeatedly performing (a) to (d) until the output waveform matched the target sinusoidal waveform set to complete the calibration process; and

storing the adjusted scale of the haptic output in a memory device in the wearable device or portable device as a new reference standard for future calibration.

11. The method of claim 10 , wherein the calibration process is performed by a working staff in a factory or by a user.

12. An electronic device comprising:

a sensorless haptic system disposed in an electronic device, the sensorless haptic system comprising:

a haptic driver; and

an electromagnetic (EM) actuator disposed in close proximity to the haptic driver, wherein the electromagnetic (EM) actuator is configured to generate a back Electromotive Force (bEMF) signal comprising sinusoidal waveform when actuated for a sensorless haptic system calibration process, wherein detection of the a back Electromotive Force (bEMF) signal for the sensorless haptic system calibration process is repeatedly performed until a target sinusoidal waveform is obtained; and

a memory configured to store an adjusted scale of the sensorless haptic system as a new reference standard for future calibration,

wherein the electronic device is a wearable device or a portable device.

13. The electronic device of claim 12 , wherein the actuator is physically connected to the haptic driver.

14. The electronic device of claim 12 , further comprising:

an input interface in electronic communication to the haptic driver.

15. The electronic device of claim 14 , wherein the input interface is configured to interact with a user or a working staff in a factory for the sensorless haptic system calibration process.