1. What is the difference between vibration motors in smartphones?

The vibration motor is the source power for smartphones. It can be mainly divided into two kinds: one is ERM motor, Eccentric Rotating Mass (rotating mass) and the other is Linear resonant motor. Among them, the linear motor is divided into Z axis motor and X axis linear motor. 

The ERM motor is similar to the motor used in the four-wheel drive car when we were children. The principle is very simple, that is a small motor drives the eccentric rotor to rotate, so as to produce vibration. 

But the main drawback of the ERM motor is the slow response speed, can not realize the urgent start, stop, the vibration of the phone is some delay. "Da Da Da" vibration effect is is not very ideal, so it is almost only staying in the thousａnd yuan phones. 

A linear motor consists of a stator and a actuator, where the stator consists of a coil and an FPC, and the actuator consists of a mass block and a magnet. The energized coil is subjected to Lorentz force in the magnetic field, and the vibrational sensation is generated by reciprocating motion with the actuator in a fixed direction. The frequency of motion depends on the frequency of the driving signal.

Linear motor has fast response speed, strong vibration force, vibration direction, vibration frequency and waveform can be adjusted, so it can achieve more complex and various customized vibration effects.

Z-axis motor is also known as coin linear vibration motor. The motor moves in the vertical Z-axis direction and the vibration stroke is relatively short. 

X-axis motor, also known as rectangular or transverse linear motor, can achieve a long stroke, long acceleration time, so the vibration is stronger than Z-axis motor.

                                 LRA's structure

Linear motor and ERM motor are different not only in structure, but also in driving scheme.

The linear driver chip can output up to 10V peak voltage, under high voltage drive, can further shorten the start and stop time, improve the vibration strength. The dozens of vibration waveforms built in the driver chip can be matched with the audio decoder to realize the audio vibration.

Through post-experience optimization, accurate and targeted vibration feedback can be achieved in a variety of scenarios.

ERM motors support neither high voltage drive output nor built-in drive waveforms.

Comparison of linear motor and rotor motor drive schemes

Highlight

X axis vibration motor >Z-axis vibration motor >ERM motor>Flat vibration motor

2. How to measure the quality of phone motor?

1) Start and stop time

vibration (vibration intensity) is the two key indicators to measure the quality of a motor, but also the key to achieve "short and powerful".

2) System adaptation is more critical

Good hardware performance is just one of the foundations of a great experience, and MIUI has been carefully tailored to tailor up to 153 vibration scenarios.

3) UI interactive touch

MIUI customizes different vibration effects for interactive operations on different interfaces. For example, the large buttons on the interface such as dial keypad, calculator keypad and input method provide short and moderate vibration feedback.

In the hover button, virtual button and other interface light button provides a brisk vibration feedback.

In the case of the recording button, notification button, and camera camera button, the vibration feedback is shorter and moderate with two clicks...

4) Ringtone with vibration

As mentioned above, the vibration waveform built into the driver chip and the AP audio decoder can realize the audio random vibration, so that the bell vibrates according to the rhythm.

In MIUI, different ringtones have different vibration effects. The vibration effects match the melody of the ringtones, making the ringtones more diverse and achieving more three-dimensional and multidimensional reminding effects.

5. Game 4D shock sensation

Through the recognition of various game sound effects such as gunfire and vehicle sound in the game, MIUI has also customized many game 4D shock sensations: different scenes (opening plane/jump landing/vehicle collision...). Different weapons (AKM/AWM/VSS...) Different kills (normal kill/headshot kill/triple kill...) All have different vibration effect feedback.

When you drive the motorcycle in the game, you can not only hear the "da da da" roar of the motorcycle, but also feel the vibration from the phone.

And when you change into a bouncing car, you can feel another kind of vibration feedback matching with this model.

The various and varied 4D vibrations brought by this X-axis motor can greatly enhance the sense of presence and immersion in the game, and various 4D vibrations and related game adaptations are still being updated. 

More about vibration motors can be found at:  

What's Phone Vibration Motor？ 

Hot Tags: Vibration motor, ERM motors, Rectangular Linear Vibration, Z-axis motor, X axis vibration motor, phone vibration motor, coin linear vibration motors