What are the differences between capacitive touch screen and resistive touch screen working environm

A capacitive touch screen is a layer of transparent special metal conductive substance attached to the surface of glass. When a finger touches a metal layer, the capacitance of the contact changes, causing the frequency of the oscillator connected to it to change to change, and information can be obtained by measuring the frequency change to determine the touch position. Since the capacitance changes with temperature, humidity or grounding, it is not stable and tends to drift.

Capacitive screen manufacturer No. 183, the middle four digits 2005, followed by 9375

A resistive touch screen is a sensor that is basically a thin film plus glass structure, and the adjacent side of the film and glass is coated with ITO (nano-indium tin metal oxide), and ITO has good conductivity and transparency. When the touch operation, the ITO of the lower layer of the film will contact the ITO of the upper layer of the glass, and the corresponding electrical signal will be transmitted through the sensor, which will be sent to the processor through the conversion circuit, and converted into the X and Y values on the screen through calculation, and the selected action will be completed and presented on the screen.

Working principle: Capacitive technology touch screen CTP (Capacity Touch Panel) uses the current induction of the human body to work. The capacitive screen is a four-layer composite glass screen, the inner surface and the interlayer of the glass screen are each coated with a layer of ITO (nano indium tin metal oxide), the outermost layer is only a thick silica glass protective layer, the interlayer ITO coating is used as the working surface, the four corners lead to four electrodes, and the inner ITO is the screen layer to ensure the working environment.

The capacitive screen environment requires no static electricity and no dust, and the resistive touch screen is not afraid of dust and static electricity, and is suitable for harsh environments.

Resistive screens can be touched with any hard object, while capacitive screens can only be touched by fingers (by static electricity) (of course, you can also use your feet). The stronger the static electricity of the hand, the higher the sensitivity, understand?

Capacitive touch screen technology works using the body's current sensing. The capacitive touch screen is a four-layer composite glass screen, the inner surface and the interlayer of the glass screen are each coated with a layer of ITO, the outermost layer is a thin layer of silicone glass protective layer, and the laminated ITO coating is used as the working surface ,..Capacitive screen manufacturers are fully touched:

The number of 183, the middle four digits of 2005, followed by 9375... Four electrodes are drawn from the four corners, and the inner ITO is a shielding layer to ensure a good working environment. When the finger touches the metal layer, due to the electric field of the human body, the user and the surface of the touch screen form a coupling capacitance, which is a direct conductor for high-frequency currents, so the finger draws a small current from the contact point.

This current flows out of the electrodes on the four corners of the touch screen, and the current flowing through these four electrodes is proportional to the distance of the finger to the four corners, and the controller derives the position of the touch point by accurately calculating the proportion of these four currents.

A resistive touch screen is a sensor that converts the physical position of a touch point (x,y) in a rectangular area into a voltage that represents the x and y coordinates. Many LCD modules use resistive touch screens that can be used with four, five, seven, or eight wires to generate the screen bias voltage and read back the voltage of the touch point.

There are many differences, the resistive screen is a soft screen, the resistive screen ** discount, and the resistive screen is a single touch. Capacitive screen hard screen, relatively expensive, ten-point touch.

Capacitance. You only use your fingers to the belly. As long as it is meat, you can touch it lightly, so that you don't need to use force.

Resistance. Anything is good to use on the screen. Sometimes the sea point is not accurate. There are many places to dot and the screen is spent.

The structure and working principle of the resistive screen.

First of all, resistive screens are divided into several categories, such as four-wire and five-wire, but what we often see is four-wire and five-wire, and the working principle is almost the same. The biggest difference is that the accuracy will vary when it is affected by external forces.

In fact, to put it simply, the resistive screen is divided into two layers, and the middle is separated by an isolator. When two layers collide with each other, the current will have an effect, and the chip will react by calculating the data between the force and the current, assessing which position of the screen is under pressure. Because resistive screens need the upper and lower layers to collide before they can react.

Therefore, when two points are pressed at the same time, the pressure on the screen becomes unbalanced, resulting in touch errors. Therefore, this principle makes it difficult to realize multi-touch on the resistive screen, and it is not easy to adjust the sensitivity of multi-touch even if it is realized through technical means.

In addition, because the resistive touch screen requires a certain amount of pressure, it is easy to cause the wear of the surface material for a long time, or the upper and lower layers lose their elasticity and cause poor contact, which will affect the normal service life of the product.

The structure and working principle of the capacitive screen.

After understanding the working principle of the resistive screen, let's take a look at the structure and working principle of the capacitive screen. In fact, the capacitive screen and the resistive screen also have two layers, but the difference is that the capacitive screen does not react through the collision between the two layers. Basically, the capacitive screen uses the lower layer to transmit signals to the upper layer, and when the upper layer is contacted by the conductor, the lower layer can receive the information and make calculations.

Therefore, the two layers of screens do not have to be in direct contact, only through the information received by the lower layers and calculations are made to determine where the fingers touch. It is precisely because of this that the capacitive screen can not only support multiple points at the same time, but also greatly improve the sensitivity of touch. And because the human body itself is a conductor, the capacitive screen can react when the finger touches the screen.

The advantage of capacitive screen over resistive screen is that capacitive screen is the principle of electrostatic drive of the human body, resistance screen is the principle of force drive, and capacitive screen can be used under harsh conditions (high temperature, high humidity, low temperature), but the use of resistive screen will be affected.

A capacitive touch screen can be simply seen as a screen composed of four layers of composite screens: the outermost layer is the protective layer of glass, followed by the conductive layer, the third layer is a non-conductive glass screen, and the innermost fourth layer is also a conductive layer. The innermost conductive layer is the shielding layer, which plays the role of shielding the internal electrical signal, the capacitive screen expert No. 183, the middle four digits 2005, and the back is 9375.

The conductive layer in the middle is a key part of the entire touchscreen, with direct leads at the four corners or four edges that are responsible for detecting the position of the touch points.

The capacitive screen responds quickly to 5-15ms, and you can touch and play games with both hands at the same time, with fast response speed and beautiful appearance.

The resistive touch screen is controlled using pressure sensitivity. Its main part is a resistive thin film screen that is very well matched with the surface of the display, which is a multi-layer composite film, which uses a layer of glass or hard plastic plate as the base layer, and the surface is coated with a transparent metal oxide (ITO) conductive layer, which is covered with a layer of hardened outer surface, smooth and anti-scratch plastic layer (its inner surface is also coated with an ITO coating), and between them there are many small (about 1 1000 inches) transparent spacers to separate the two ITO conductive layers of insulation. When the finger touches the screen, the two conductive layers that are usually insulated from each other have a contact at the touch point, because one of the conductive layers is connected to the 5V uniform voltage field in the direction of the y-axis, so that the voltage of the detection layer changes from zero to non-zero, and the controller detects this connection, performs a D conversion, and compares the obtained voltage value with 5V to obtain the Y-axis coordinates of the touch point, and the X-axis coordinates are obtained in the same way, which is the most basic principle common to all resistive technology touch screens.

The resistive screen is cheaper than the capacitive screen, the resistive screen is not as fast as the capacitive screen, the resistive screen is a single touch, the capacitive screen supports 10-point touch, and you can see that the capacitive screen has a greater advantage than the resistive screen.

The structure of the capacitive touch screen is mainly to coat a transparent thin film conductor layer on the glass screen, and then add a piece of protective glass outside the conductor layer, and plate narrow electrodes on the four sides of the touch screen to form a low-voltage alternating electric field in the conductor. When touching the screen, due to the existence of the electric field of the human body, a coupling capacitance will be formed between the finger and the conductor layer, and the current emitted by the four electrodes will flow to the contact, and the current strength is proportional to the distance from the finger to the electrode, and the controller behind the touch screen will calculate the proportion and strength of the current to accurately calculate the position of the touch point.

Compared with resistive touch screens that were common on the market at the time, capacitive touch screens had obvious advantages. First of all, a capacitive touch screen only needs touch and does not require pressure to generate a signal, while a resistive touch screen is activated by pressure. Secondly, capacitive touch screens have a long average lifespan.

Again, in the resistive touch screen, the upper film needs to be thin enough to be elastic, so that it can bend downward to contact the film below, so it is easy to be damaged, while the capacitive touch screen cover can be relatively thick, and there is glass protection, good scratch resistance, which can better protect the conductor and inductor. In addition, the capacitive touch screen is more durable, less prone to aging, and resistant to high temperatures. Moreover, the double glass design of the capacitive touch screen can more effectively prevent the impact of external environmental factors on the touch screen, even if the screen is stained with dirt, dust or oil stains, the capacitive touch screen can still accurately calculate the touch position.

More importantly, the touch screen at this time has developed from the early analog touch screen to the digital touch screen, which can realize multi-touch.

When testing the touch screen, it is necessary to choose a high-current shrapnel microneedle module, and the appropriate test module can play a good connection function, and can play an excellent role in the on-current and transmission signal!

The difference for the user is that the capacitance only works by the hand, and it is extremely sensitive! The feeling of resistance can work for anything, but it is not sensitive, and the keys need to be forced...! After using N8 and N97, you can clearly feel the difference between capacitance and resistance!

Capacitive screen is more NB recommend Meizu M8

Resistance touch is to read out the parameters by touching the change of the resistance value.

Capacitive touch is the change in the capacitance value that is coupled by the charge, and the parameters are read out.