Custom Capacitive and Resistive Touch Panels

Touch Panels from Design Mark

A touch screen is a transparent switch placed over a visual display. The switch enables interaction through physical contact by detecting the presence and location of a touch. The touch screen interface is one of the easiest to use and most intuitive of all computer interfaces, because it allows users to quickly navigate a computer system by touching icons or links on the screen.

Touch Screen Interface Product Features:

  • Virtually infinite options for user interface design and flexibility compared to physical buttons/switches
  • Easy-to-use interface for any industry (e.g., automotive and retail touch screens)
  • Requires less space – integrated design eliminates the need for external keyboards and other components
  • Sealing options can make touch screens highly resistant to environmental conditions

Components of a Touch Screen

A touch panel consists of a conductive bottom layer of either glass or film and a conductive top film layer, separated by small, transparent spacer dots. A voltage is applied across the conductive surface. When pressure from a touch is applied to the top layer, it is deflected and makes contact with the bottom layer, which results in a voltage drop. This change is detected by the controller. By alternating the voltage signal between the top layer and the bottom layer, the X and Y coordinates of the user’s touch are computed. This permits the display to function as a control panel and allow human-machine interface (HMI).

A touch panel typically has the following basic components:

  • Touch sensor – A touch-responsive surface, usually a glass panel placed over a visual display monitor. The technologies vary slightly but, typically, the sensor registers change in electrical signal distortion to sense a touch event and location.
  • Controller – An electronic device (PCB) is the interface between the sensor and the display. The controller takes information from the touch screen and translates it into information a computer can understand.
  • Software driver – A computer program enables the computer operating system and the controller to communicate.

Our design and engineering team will guide you to select the custom touch screen for your application’s requirements. Next, we’ll design and integrate the user interface (touch screen buttons) and touchscreen overlay into a value-added assembly for your product. Design Mark combines its expertise in user interface application and overlay production and can introduce hybrid products that marry custom labels, graphic overlay products, seals and gaskets, and membrane switches with the resulting touchscreen product hardware.

Resistive vs. Capacitive Touch Screens

To achieve the desired human-machine interface (HMI), you can choose from two types of touch screen technologies: resistive touch screens and capacitive touch screens.

  • Resistive touch screens – This is the preferred solution for low-cost applications. It consists of a conductive bottom layer of either glass or film and a conductive top film layer, separated by transparent spacer dots. A voltage is applied to the conductive surface. When pressure is applied to the top layer, it is deflected and makes contact with the bottom layer, which results in a voltage change. This change is detected by the controller. This technology is functional and economical for applications such as industrial controls, point-of-sale (POS), and handheld devices. Resistive touch screen features include:
  • Activation by finger, glove, or stylus
  • High touch point resolution
  • Low power requirements
  • Value solution
  • Reduced optical clarity
  • Capacitive touch screens – Capacitive touch panel design has an all-glass construction with greater than 9H surface hardness. A transparent conductive indium tin oxide (ITO) coating is distributed over both sides of the glass substrate. An electrode pattern is printed around the perimeter of the glass to generate an alternating current over the top conductive layer. The touch of a conductive probe draws the current to the specific point of contact. The controller then calculates the location of the touch. Capacitive technology provides durability, reliability, and enhanced optical clarity. However, it is restricted to touch sensitivity by conductive materials such as a bare finger or capacitive stylus. Design Mark is a well-respected capacitive touch screen manufacturer serving a wide variety of industry applications such as casino gaming machines, industrial equipment, ATM machines and point-of-sale (POS) kiosks.

Custom Touch Screen Design Considerations

When considering a touch screen application, Design Mark’s designers and engineers will ask you these questions to determine the right technology for your application:

  • Interface: What type of touch interface is needed – finger, gloved finger, both, or stylus?
  • Is it a small touch screen or large?
  • Options: Are touch buttons, drag and drop, or signature capture needed?
  • Display clarity: Is optical clarity a high consideration?
  • Environmental: Will it be exposed to chemicals, liquids, or extreme weather conditions?
  • Cost: What are the cost considerations?