Traditional function phones and early smart phones do not pay attention to vibration experience, and their technical investment is limited. Therefore, in the selection of vibration motors, most of them are equipped with the most common rotor motors, which are very small in size and use electromagnetic induction to drive the rotor to rotate to produce vibration.
In the later period, the supply chain manufacturers upgraded the design of the rotor motor, and introduced the flat rotor motor, which looks like button cell. Because the thickness is controlled, it is very suitable for thin smart phones, but the vibration experience is not much improved compared with the initial rotor motor.
Because of the uneven counterweight in the internal structure of the rotor motor, it doesn't sound clean and tidy from the vibration sound, and there will be a little delay in the somatosensory experience of vibration. Moreover, the time from the user's touch to the start of vibration and the time from the user's stop of touch to the stop of vibration are delayed, so the overall vibration feedback is not timely enough and there is a very obvious sense of lag. Due to the vibration delay, the vibration sound has also become "buzzing".