Half the technical support we do is not technical. It is agreeing on what a word means. The same assembly is quoted as an infrared touch frame, an IR touch screen, a touch overlay, a touch frame kit and an infrared touch panel, sometimes by the same customer in the same email thread. This page is the list we keep beside the phone.
Frame, screen, panel, TP, overlay, kit
A touch frame is the sensor ring only — the aluminium, the LEDs, the controller. A touch screen is that ring plus a display behind it. In practice the two get used for the same purchase: a buyer who asks for a 55 inch infrared touch screen usually wants the frame and already has the LCD, because a finished 55 inch touch monitor would cost three times as much and arrive with a panel they did not choose.
A panel means one of two things and you have to read the context. In "capacitive touch panel" it is the glass-and-sensor sandwich with no display. In "LCD panel" it is the display itself. TP is shorthand for touch panel and shows up constantly in drawings translated from Chinese — a capacitive touch TP is not a different grade of part, it is the same panel with a shorter name. Overlay describes what the part does rather than what it is: a frame that drops over an existing display without bonding or firmware changes. Kit describes what ships in the box: frame, controller, cable, brackets.
Infrared, capacitive, PCAP, resistive
Infrared (IR) frames put LEDs and photodiodes around the perimeter and detect a broken beam. Capacitive panels measure the change in capacitance of an ITO grid when a finger approaches. PCAP and projected capacitive mean the same capacitive method — the electrodes are projected through the cover glass rather than sitting on its surface. Every capacitive product on this site is PCAP, which is why the term is not a separate product line.
Resistive is the older membrane stack: two transparent conductive layers pressed together. Still correct for a factory that runs gloved operators on a small screen with a stylus, and still cheaper than either of the others below 7 inch — but it has no multi-touch worth the name and the top layer scratches. We do not build it, and if a customer asks for it we usually find they wanted infrared with a glass front.
OD, VA, AA and sensor size
OD is the outer dimension of the part, which is what your housing is cut to. VA (view area) or AA (active area) is the part that actually responds to touch or shows an image. The sensor is the ITO pattern, which is neither: it sits a millimetre or two inside the OD and defines where the invisible electrodes end. Confusing OD with VA is the most common cause of a panel that arrives 3 mm too big for its housing. The stack-up guide walks through the three numbers on a real 21.5 inch part.
G+G, G+FF, G+F
The letters describe the stack: the first letter is the sensor substrate, the second is the cover. G+G is glass sensor under glass cover, the standard for anything that has to survive being cleaned or dropped. G+FF is film sensor under film, thinner and cheaper, and it is what most kiosks actually use. G+F is glass sensor under a single film. Performance is close; the difference shows up in thickness, edge durability and price.
Bezel, printed border, FPC tail
A bezel is the metal frame around an infrared screen, typically 13 mm on the sides and 19 mm at the bottom where the controller lives. A printed border is the black (or white, or colour) band printed on the edge of a capacitive panel to hide the electrodes and the tail bond — usually 6 to 20 mm, and the reason a capacitive product looks edge-to-edge. The FPC tail is the flexible ribbon that carries the signal out to the controller. Where it exits matters: left, right, top or bottom, same side or opposite side, and changing it later is expensive.
Controller, driver board, interface
Controller and driver board are the same PCB. The interface is how it talks to your system: USB HID is the default because Windows, Android and Linux already have the driver, so it is genuinely plug and play. I2C is for embedded boards that have no USB host. RS232 survives in industrial retrofits and in anything running a long cable. The interface guide covers cable length limits, which is where most integration problems actually come from.
Touch points, report rate, accuracy
Touch points is how many simultaneous fingers the controller resolves. 10 is the low-cost default; 20 is what Windows 10 / 11 and current Android boards actually accept, so a 20-point controller is the practical spec for a kiosk or a classroom board; 32 to 40 only pays off on a Linux build with its own input stack. Report rate is how often positions are sent, in Hz; below 60 the cursor feels laggy when drawing. Accuracy is the maximum positional error in millimetres, usually ±1 to ±2 mm on infrared and ±0.5 mm on small capacitive panels. None of these three are improved by paying more for a bigger name — they are set by the controller you specify.
Bonding: OCA, water glue, air gap
A touch panel in front of an LCD traps a layer of air unless you bond it. OCA is a solid optical adhesive sheet, the cleanest result and the most expensive. Water glue is a liquid UV-cured adhesive, cheaper, and prone to bubbles if the process is rushed. Air gap is no bonding at all, which is fine indoors and a problem outdoors where the gap fogs. When a customer asks for a touch display module, this is the decision being quoted.
The short list for a purchase order
- Infrared touch frame / IR touch frame: aluminium frame, controller, cable. No glass, no display.
- Infrared touch screen: the same part, described by the product it will become.
- Touch overlay / IR overlay: the same part, described by how it is installed on an existing display.
- Capacitive touch panel / capacitive touch screen / capacitive touch TP / PCAP panel: glass, sensor, tail, controller. No display.
- Touch display module: panel bonded to an LCD, one part number.
If the word you have is not on this list, send it anyway with a photo of the old part or the housing opening. A dimension settles an argument faster than a definition.
Tell us the size. We will tell you what fits.
Send a drawing, a size, or just a photo of the screen you are building around. Our engineers reply with a matched part and a price within 12 working hours.