The Disadvantages of a PC Light Pen
- Light pens are about the same size as a typical ink pen.pen image by Krasser from Fotolia.com
In a 1984 edition of "InfoWorld," software creator George Grayson commented that "if the mouse turns out to be as popular as it's being portrayed, use of the light pen will be limited." The pointing device, which allows you to make selections on a computer screen, enjoyed a period of heavy adoption after IBM invented it in the 1960s, but the more popular mouse has since replaced the light pen. Although there are still many reasons why someone might want to use a light pen, the device has a number of disadvantages when operated alongside modern computer hardware. - CRT monitors are bulky and consume more power than LCDs.pc monitor image by Jorge Casais from Fotolia.com
Because of the way light pens work, they are only compatible with CRT monitors. This is because while a CRT monitor updates the picture by streaming a beam of light across the screen, LCDs only update the parts of the screen where the picture has changed. Light pens need the beam of light CRTs provide to detect their position on the screen.
Before LCDs became commonplace items, this limitation was not an issue. But very few computers are now available with CRT monitors and laptop monitors use LCDs exclusively. If you have a newer computer, you will likely have to find an old CRT monitor to use a light pen and add quite a bit of bulk to your workspace in the process. - Modern video cards do not have an input for light pens.video card image by TEA from Fotolia.com
Early computer video cards included connectors for light pens, but modern graphics hardware does not provide an interface for attaching light pens. Consequently, old light pens will not work with modern PCs without extensive modification. A few companies do manufacture light pens that connect via USB 2.0, but these devices are not widely available. - Mouse users may have trouble adjusting to light pens.computer mouse image by jimcox40 from Fotolia.com
Light pens provide the same functionality as a mouse, but take time to learn how to use. This is especially true if you are accustomed to using a mouse. Sometimes users have to adjust aspects of their computer, such as the color of the desktop background, to make light pens easier to use. It may also take time to calibrate your light pen to the desired sensitivity.
