Add touchscreen to your monitor


Schools and some businesses have used a touchscreen whiteboard for some years now. The two technologies being used are a top mounted “short throw” projector that projects the image onto the whiteboard or a rear projector shows the image without shadows. These are being replaced by touchscreen monitors because they require less modification to the rooms. Touch screens add a large cost to the monitor’s price.

Touchscreen technology

There are 3 kinds of touch technology, the earliest being resistive touch. An overlay is attached to the screen and when you touch with a stylus, the interface can detect where the stylus has been pressed based on a grid of tiny wires that short at the point where you pressed. However, this system only allowed one object to touch the screen at any one time.

Capacitive touch screens rely on skin capacitance to work, as dry fingers have a capacitance that is different to the capacitance of the glass that they work behind. Since the hardware can sense multiple finger presses at once, multi touch is possible. Gestures have been created to pinch and zoom, shrink and move objects around.

Infra-red touch screens can work with gestures but they don’t have to be part of the screen, instead provided as a frame to go round the outside of the screen.

Add your own touch screen

Consider that a non-touchscreen 21.5″ monitor will cost about £100 to buy, the touchscreen version is almost 3 times the price.

Since infra-red touch screens are simply a frame you mount on your existing monitor, they can be purchased at a later date and “retrofitted”.

You can get the retrofit pack, which you screw the sides together and attach to your monitor, connect the USB cable and your computer will recognise the device as a HID device, and probably will think it’s a mouse.

Pricing depends on the size of screen with 15-19″ screens being £110, 21-24″ screens being £120 and 27″ screens being £130.

You can buy these at Amazon here.

If you are an educational establishment or business using a larger display screen or projection screen and want to make it touch screen, or if you are using your TV as a monitor, the retrofit packs are priced £150 for 32″, £170 for 40-42″, £180 for 43″, £200 for 49″, £220 for 50″, £240 for 55″,   £260 for 60″, £300 for 65″, £320 for 70″, £350 for 75″, £400 for 85″ and £450 for 98″.

You can buy these at Amazon.

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