Among them, active products need to cooperate with the touch screen to be used normally, so they are not considered as general products; The advantage is that it can provide more accurate handwriting operation, and some products also have functions such as pressure sensing and digital signature support.

A passive product is actually just a conductive object, which is used to reach out and point. Its distance and experience are not much different from fingers, but its advantage is universal, and it can be used as long as it is a capacitive touch screen.

Capacitance pen:

Capacitance pen is a conductive pen made of conductive material, which is used to touch the capacitive screen and complete the man-machine dialogue operation. Capacitance pen is used to touch electronic devices such as mobile phones and computers with capacitive touch screens.

Capacitive touch screen works by current induction of human body. It's a four-layer composite glass screen. The inner surface and interlayer of the glass screen are coated with a layer of ITO (namely coated conductive glass), and the outermost layer is a thin protective layer of Shi Ying glass.

ITO coating is used as working surface, four electrodes are led out from four corners, and inner ITO is used as shielding layer to ensure a good working environment.

When the finger touches the metal layer, the human electric field, the user and the touch screen surface form a coupling capacitance. For high frequency current, the capacitor is a direct conductor, so the finger draws a small current from the contact point.

This current flows from the electrodes at the four corners of the touch screen, and the current flowing through these four electrodes is proportional to the distance from the finger to the four corners. The controller obtains the position information of the touch point through the accurate calculation of these four current ratios.

Capacitance pen is an auxiliary device that uses conductive materials to imitate human body (usually fingers) to complete man-machine conversation.

The main difference is to prevent accidental touch. IPad after 20 18 support anti-misoperation. This is because of the design of the iPad itself. IPad after 20 18 (not used for mobile phones, but I heard that iPhone 13 may support this function).

Both support apple pencil and third-party capacitance pen to prevent accidental touch; A compatible pen means that you can write on any screen, but it doesn't prevent accidental touching. If the model supports, it is recommended to buy a capacitance pen that can prevent accidental contact.