Resistive Touch Panels
Today there are over 20 different technologies that revolve around touch panels. A common type of touch panel is resistive touch panels (RTPs) which in 2012 made up approximately 26% of the market. These work by combining two conductive electrode layers separated by very small transparent insulation spacers also known as spacer dots. When pressure is applied from a finger or stylus it brings the two layers into contact. This results in a drop in voltage at the contact point which is then detected by a controller. There are three types of resistive touch panels each with its own unique attributes, 4-wire, 5-wire, and 8-wire.
Although there are three different types of resistive touch panels each work under the same principle, applied pressure brings two conductive layers together. The 4-wire construction consists of two separate layers; one layer carries the X and the other that carries the Y. A touch (applied pressure) will bring the two layers together and the contact point will then be calculated. The disadvantage of a 4-wire is if the top layer becomes scratched or ripped the X coordinate will no longer function and will need to be replaced. A 5-wire touch panel is constructed with a film that is suspended over the top layer and voltage is simultaneously measured at each corner. When a user touches the top surface it becomes in contact with the bottom layer causing a change in resistance which would then be calculated by the controller. Since the top layer is acting only as a probe it will still function if the top surface becomes scratched or torn unlike the 4-wire making it a more durable design.
The last type is the 8-wire and this is based on the 4-wire technology principle by adding an additional 4-wire set. Having the additional set doubles the level of electrodes and in turn, will increase the overall accuracy and reduces drifts so you won’t have to recalibrate as much as you would with a 4 or 5-wire touch panel. The general benefits of resistive touch panels include the lowest costs in comparison to other types of touch panels. Additionally, they offer low power consumption and are pressure actuated with a finger, gloves, stylus, etc. RTPs are also resistant to external factors such as water and dust so if the end product were to be used in an outdoor application or in a machine shop it won’t create a false actuation. Here are some limitations to consider when deciding whether or not RTPs are suitable for your application. You may be more familiar with multi-touch panels but the standard for resistive touch panels is one-touch. There are some controller companies working on multi-touch technology with resistive touch panels but again, it’s not the standard.
Another limitation is the relatively low light transmission which approximately runs 76 – 82% so if your graphics within the end product is a priority you may want to reconsider another type of panel. The touch life is lower for resistive touch panels because they use ITO film as the conductive material which is less durable than other options. Repeated pushing and selecting over time will create fractures and can degrade the touch panels’ ability to operate. With a 4-wire and 8-wire expect 1 million actuations in one location because they both share the same technology. The 5-wire will allow 10 million actuations. The standard sizes for all range from 2.8″ – 21″ with additional custom sizes available.
Golden Margins –Entire Range of Touchscreen Products
We hope you found these touchscreen or panel PC fundamentals informative. Goldenmargins offers a broad selection of Industrial Touchscreen Monitors and Touch Panel PCs in various sizes and configurations, including medical touch screens, sunlight-readable touch screens, open-frame touch screens, and waterproof touch panels, as well as other unique touch screen or panel PC designs. You can learn more about our services HERE or by calling us at +86 755 23191996 or sales@goldenmargins.com
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