Capacitive pen principle

Mobile phone crystal 3.2*2.5mm 3225 26M (26.000MHZ) 7.5PF 10PPM 20PPM 30PPM

Single chip microcomputer STM32L151CCU6

Tantalum capacitor

Guide: The capacitive pen is a conductor material. If you want, any conductor can be used as a capacitive pen , key, ear spoon, pencil lead, etc. Let's learn the principle of the capacitive pen .

1. Capacitor pen principle - introduction

With the rise of capacitive touch screens, capacitive pens have also been forced to revolutionize the material. Due to the different principles of screen touch, the traditional resistive screen can be touched with a pen or a sharp object. The concept is not suitable for iPhone, iPad or other smart products. The emergence of a capacitive pen is solving this problem. The capacitive pen is a pen made of a conductive material and has a conductive characteristic for use in a touch-capacitive screen to perform a man-machine dialogue operation. The capacitive pen is used to touch electronic devices such as mobile phones and computers with capacitive touch screens.

2. Capacitor pen principle - classification

At present, the capacitive stylus on the market mainly uses conductive materials such as conductive cotton, rubber (surface coated conductive paint) and conductive fibers. The principle is that conductive materials are used on the surface. Capacitive pens can be divided into capacitive active pens and capacitive passive pens.

Capacitor active pen, there is a circuit in the pen, the pen emits a signal to the touch screen matrix to receive, to detect the pen's coordinates, the pen is medium, to be charged, and can design a variety of functions.

A capacitive passive pen can be used as a finger and does not emit a signal by itself, but contact with the touch screen can change the capacitance of the touch screen matrix. This pen does not emit a signal, so it is either very large; or the phone is mainly used for this function, and the touch screen resolution is designed to be very high for passive pens.

3. Capacitive pen principle

When it comes to capacitive stylus, we must first talk about the principle of capacitive touch. Capacitive touch is divided into surface capacitive touch and projected capacitive touch screen. The principle of capacitive touch is that when a finger or other conductive material is touched to the panel, the panel detects the change in capacitance of the surface to generate an electronic signal, and determines the touch position. Therefore, you can use your fingers or other conductive materials to control. Generally, the traditional conductive plastic stylus can not be controlled.

A capacitive pen is an auxiliary device that uses a conductor material to mimic the human body (usually a finger) to complete human-machine dialogue. When the finger touches the metal layer, since the human body electric field, the user and the touch screen surface form a coupling capacitance, for the high frequency current, the capacitance is a direct conductor, and the finger sucks a small current from the contact point. This current flows out from the electrodes on the four corners of the touch screen, and the current flowing through the four electrodes is proportional to the distance from the finger to the four corners. The controller calculates the touch ratio by accurately calculating the ratio of the four currents. location information.

Expand reading:

1. Touch screen application market channel widening

2. Multiple choice capacitive touch screen tablet solution

3. Capacitive multi-finger touch solution