How Resistive Touchscreen Displays Detect and Respond to Touch

In the industrial field, touchscreen displays are widely used in various control panels, automation equipment, and monitoring systems as important human-computer interaction devices. Resistive touchscreens have always been the mainstream choice for industrial displays due to their low cost, strong adaptability, and accurate response. This article will delve into the detection and response mechanism of resistive touchscreens to help readers better understand their working principles and application scenarios.

I. Working Principle of Resistive Touchscreens

1. Structural Composition
   Resistive touchscreens are composed of multiple layers of composite films, mainly including:
   Base Layer: Usually glass or acrylic glass, providing robust support.

Conductive Layer: Two layers of transparent conductive material (such as ITO, indium tin oxide), used to detect touch signals.

Isolation Layer: Tiny gaps separate the two conductive material layers, preventing them from contacting each other when not touched.

Outer Protective Layer: A hardened plastic layer to prevent scratches on the conductive layer.

2. Basic Principle of Touch Detection
   Resistive touchscreens operate based on pressure-sensing technology. When a user presses the screen with their finger or stylus, a circuit is formed between the upper and lower conductive layers at the contact point, causing a change in resistance. The controller determines the location of the touch point by measuring this resistance change.
3. Coordinate Detection Method

Four-wire resistive touchscreen: This is the most common type of resistive touchscreen. It calculates coordinates by applying voltages along the X and Y axes and measuring the voltage change at the touch point.

X-coordinate detection: A driving voltage V_ref is applied to the X+ electrode, and the X- electrode is grounded, forming a uniform electric field. Upon touch, the voltage at the touch point is collected through the Y+ electrode, calculated using the formula x = \frac{V_{Y+}}{V_{ref}}\times Width.

Y-coordinate detection: A driving voltage V_ref is applied to the Y+ electrode, and the Y- electrode is grounded, forming a uniform electric field. When touched, the voltage at the touch point is collected through the X+ electrode, calculated using the formula: y = \frac{V_{Y+}}{V_{ref}}\times Height .

Touch detection: A touch is detected by measuring the resistance change between two conductive layers. Typically, a weak pull-up resistor and a strong pull-down resistor are used to detect the voltage change, thus determining the touch state.

II: LEEHON Technology: A Professional Resistive Touchscreen Supplier

As a leading industrial display supplier in China, LEEHON Technology focuses on providing high-quality resistive touchscreen solutions. Its products feature high precision, high durability, and good anti-interference capabilities, making them suitable for various industrial environments. LEEHON Technology’s resistive touchscreens support single-point touch, have fast response times, and can meet the precise operation requirements of industrial equipment. Furthermore, LEEHON Technology also provides customized services, designing and manufacturing touchscreen displays that meet industrial standards according to specific customer needs.

III: FAQ (Frequently Asked Questions)

1. Does a resistive touchscreen support multi-touch?

Traditional resistive touchscreens struggle with multi-touch functionality because their detection mechanism relies on changes in resistance at a single point. However, some new resistive touchscreen technologies are attempting to overcome this limitation.

2. How fast is the response time of a resistive touchscreen?

Resistive touchscreens typically have a response time of less than 10ms, sufficient for most industrial applications.

3. Can resistive touchscreens be operated while wearing gloves?

Yes, resistive touchscreens, based on pressure sensing, support operation while wearing gloves or using non-conductive objects. This gives them a unique advantage in industrial environments.

4. How durable are resistive touchscreens?

Resistive touchscreens are quite durable and resistant to physical damage. Their outer protective layer effectively prevents scratches, and even scratches on the outer conductive layer will not affect usability.

5. What is the light transmittance of a resistive touchscreen?

The light transmittance of resistive touchscreens is typically around 80%, lower than capacitive touchscreens, but sufficient for industrial applications.

Summary

Resistive touchscreens determine touch position by detecting changes in resistance between two conductive layers. They offer advantages such as low cost, precise response, and support for operation while wearing gloves. They are widely used in industrial applications, especially in environments requiring precise control and harsh conditions. LEEHON Technology, as a professional supplier, provides reliable resistive touchscreen solutions to industrial users through its high-quality products and customized services. With continuous technological advancements, resistive touchscreens will play an increasingly important role in more industrial scenarios.