four-wire resistive touch screen and five-wire resistive touch screen

The difference and technical comparison between four-wire resistive touch screen and five-wire resistive touch screen

OneTouch -4W four wire resistance

The bottom layer of the screen is a general glass plate. There are two layers of ITO Film on the glass. The upper layer is used to read the y-axis voltage value, and the lower layer is used to read the x-axis voltage value. The two layers of film are close together, and the surface is coated with ITO. In contrast, the middle is separated by tiny, transparent insulating “separation points”. In the standby state, the CPU alternately supplies the +5 voltage to the upper y-axis and the lower x-axis at a very fast frequency. When one layer is conductive, the other layer is grounded to read the voltage value. The voltage value on the film is continuously converted by the A/D converter and monitored by the CPU on the control card. When the screen is touched, the ITO on the upper film and the lower film are connected. After the CPU checks it, the following processing is performed. The CPU first supplies the lower x-axis +5v and grounds the upper y-axis; when touched, the upper layer digitizes the voltage of the lower x-axis and calculates the x-axis coordinates. Then the CPU supplies the y-axis +5v and grounds the lower x-axis; when touched, the lower layer sends out the voltage value on the upper y'axis, and the A/D converter digitizes the voltage value to calculate the y-axis coordinate.

The four-wire resistor is a multilayer polyester structure, also called a plastic-plastic-glass (plexiglass) structure. Due to the layered structure attached to the back of the glass or plastic by the adhesive, the additional layer produced will reduce the light clarity, and in long-term use, it is easy to produce inter-film delamination and linear decline due to film type deformation. The x-axis and y-axis must be measured through two layers. The y-axis soft surface layer has a uniform voltage gradient, and the bottom substrate is the voltage probe. The continuous deformation of the outer surface layer will change its characteristics (resistance), thereby reducing the linearity and accuracy of the shaft.

The durability of the four-wire resistor is relatively strong, and the maximum number of touches is 3 million. It cannot be used after partial scratching. The surface hardness is 3H, the production process is relatively simple, and the cost is low. It can be applied to consumer products below 10.4 inches: PAD/mobile phones and other small-size products such as PAD/car phones/mobile phones.

OneTouch -5W five-wire resistor

The bottom layer of the screen, which is attached to the cathode ray tube (CRT) or liquid crystal display (LCD), is a glass plate (ITO Glass) coated with a uniform conductive material-ito. The outermost layer is a layer of polyester film (ITO Film), which has a unique metallic conductive coating film ITO on the inside and a reinforced coating film on the outside. The ITO Film is tightly suspended on top, and the ITO-plated surface faces each other, and the two layers are separated by a tiny transparent insulation [segment point].

In the standby state, the four wires on the Glass will send out +5 volts current, the voltage value on the ITO Film is 0, and the voltage value on the ITO Film is continuously converted by the A/D converter, and the CPU on the control card Monitoring. When the screen is touched, a line on the Film will send out the voltage at that point. After the microprocessor detects it, it performs the following conversion processing. The microprocessor first supplies the x-axis +5v and grounds the y-axis. When touched, the adc digitizes the voltage value and calculates the x-axis coordinate position. Next, the microprocessor supplies the y-axis +5v and grounds the x-axis. When it touches the city, Film will send the voltage value of the point on the y-axis, and the ACD digitizes the voltage value to calculate the coordinate position of the y-axis.

The structure of the five-wire resistor is simple, using a glass substrate structure with a polyester surface layer covering ITO glass. Called a plastic-on-glass structure, this structure has the least number of optical characteristics. The least easy to layer and has the best light transmittance and stable reliability. Use the base plate to measure the x and y axes, and the soft surface layer serves only as a probe for measuring voltage. This means that the touch screen can keep working continuously, even if the conductive coating on the surface is uneven. The result of using this technology is that the touch screen can accurately, lasting, stable and reliable measurement and drift-free work. The maximum number of touches of the five-wire resistor is 35 million times. After partial scratches, the screen can still be used normally. The special scratch-resistant layer has a surface hardness of 4H. The production process is more complicated and the cost is high. It can be applied to 10.4 inches or more. , Industrial and public products: POS/ATM/industrial control/touch query terminal, etc.