What Is An Infrared Touch Screen? And How Does it work?

Interactive flat panel displays (IFPDs) featuring infrared touch screens have gained popularity in recent years.

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In comparison to smart projector boards, which were commonly used in education, IFPDs are more convenient and practical.

There’s no need to calibrate a projector before a lecture; with LED lighting technology, IFPDs provide a clear image throughout, and thanks to the IR touchscreen, presenters can annotate their presentations using nearly any object, whether it be a dry or wet finger, pen, or stylus.

Today, we will focus on the IR touchscreen to explore how it enhances user experience.

What Is An Infrared Touchscreen?

An infrared touch screen is composed of an LCD monitor, an IR touch frame, and an infrared touch overlay.

Typically, the overlay consists of a protective glass piece encased by the IR touch frame, which contains embedded infrared LEDs and photodetectors. An optical bezel is inserted between the glass and the frame to secure the setup and transmit the infrared light emitted by the LEDs.

IR LEDs emit invisible infrared beams through the optical bezel, creating grids on the overlay's surface. Photodetectors, placed opposite to the LEDs, detect any interruptions in these beams during touch events.

How Does Infrared Touchscreen Work?

The infrared touchscreen operates by detecting interruptions of infrared beams emitted by LEDs in the frame surrounding the touchscreen overlay.

It comprises two rows of IR LEDs that generate invisible horizontal and vertical beams, forming a comprehensive beam grid over the overlay's surface. Corresponding photoreceptors are installed on the opposite side of the LEDs.

When an opaque object touches the surface, it obstructs the light beams. Photoreceptors detect these interruptions in both vertical and horizontal directions, which enables them to locate the x and y coordinates and send signals to the processor for an appropriate response.

To gain deeper insights into its structure and functioning, it’s advisable to explore a workshop that demonstrates the assembly process. Although opportunities may be limited, regular maintenance allows you to check internal components.

Take a look at the video below for more information.

How To Install An Infrared Touch Screen Interface (Overlay)?

Regular maintenance is essential to ensure the smooth operation of IR touch screen equipment. This process involves cleaning and re-installing the interface (overlay).

1. First, remove the screws from the bracket used to secure the LCD monitor and touchscreen overlay.
2. Next, take out the bracket.
3. Place the overlay on a flat workbench.
4. Use a canned air duster to clean out any dust inside the sheet metal frame.
5. Clean the interior surface of the glass overlay with a mild cleaner only; do not use chemical solvents.
6. Clean the surface of the monitor.
7. With the help of a partner, gently reinstall the overlay.
8. Return the bottom bracket to its original position.
9. Secure the bracket with new screws.

Alternatively, review this video for further instructions.

Benefits Of Infrared Touch Screen Technology

Aside from infrared touch technology, resistive and capacitive touch technologies are also well-established in the market, demonstrating stable performance.

Resistive and capacitive touch technologies have been around longer than infrared touch screens.

Yet, many engineers prefer infrared touch screens for interactive whiteboards utilized in business meetings and distance learning.

• Economical option: IR touch screens are relatively inexpensive in large sizes compared to other touch technologies.
• Better display: With no additional materials between the LCD and overlay, IR touch screens provide superior light transmission, rendering vivid images without compromising color or brightness.
• Supports multi-touch: With dual operating systems (Windows and Android 9.0), they can support up to 40 touchpoints simultaneously, accommodating group participation on an IFPD.
• Short response time: Typically under 8ms, IR touch screens accurately respond to interruptions in light, ensuring quick action.
• Exceptional writing experience: The overlay, often made from tempered glass, provides a smooth writing surface.
• Scratch-resistant: The glass overlay protects the LCD monitor, preventing scratches.
• Flexible screen size customization: By adjusting the number of embedded LEDs and photodetectors, you can create custom-sized infrared touch interfaces.
• Easy maintenance: Without adhesive materials between the monitor and overlay, disassembling for regular maintenance is straightforward.
• Clear images: Compared to many camera- or projector-based systems, IR touch screens typically utilize backlight LEDs to deliver clear visuals in various lighting environments.
• 4K resolution support: They are compatible with 4K resolution displays, working efficiently with high pixel monitors.
• No display obstructions: As LEDs and sensors are fixed around the monitor, the screen offers an unrestricted view.
• Versatile writing tools: You can use anything from a bare finger to a gloved hand or pen, provided it is not transparent.
• No calibration required: Unlike traditional smart projectors, IR touch screens do not require calibration for optimal operation.
• No pressure needed: For writing, IR touch screens do not necessitate pressure to detect input, eliminating potential damage from prolonged use.

Difference Between Capacitive and Infrared Touch Screens

Among touch screen technologies, infrared and projected capacitive types are the most commonly used, although they serve different applications due to their inherent differences.

Workings

In PCAP (Projected Capacitive) touch screens, a layer of transparent electrode film is placed between the LCD panel and cover glass. When a finger touches the screen, the electrical current through that film alters, relaying the x and y position signals to the computer.

In contrast, IR touch screens detect the finger’s position by recognizing the interruption of invisible rays emitted by infrared LEDs incorporated in the touchscreen frames.

Structure

Often, an IR touchscreen will have a bezel designed to transfer infrared light to the overlay surface, whereas PCAP touch screens do not require a bezel.

Multi-touch

PCAP touch screens support only two-point input, while IR touch screens can support up to 40-point inputs.

Activated by

IR touch screens can be triggered by any non-transparent object, whereas PCAP types only respond to bare fingers, thin surgical gloves, or cotton gloves.

Price

The transparent electrode film used in PCAP touch screens is costly, particularly for larger screens. In contrast, IR technology only requires a few additional LEDs and corresponding detectors, making it a more economical solution for large interactive displays, such as digital boards used in business presentations.

Applications

Due to cost-effectiveness and multi-touch capabilities, IR touch screens predominantly find application in larger screen formats, whereas PCAP technology is commonly used in smartphones and tablets.

For further information, please visit our website IRTOUCH.