Wand or Pen Readers

Wand (pen) readers are the lowest-cost entry-level barcode scanning technology, requiring direct contact and a swiping motion across the code.

Wand readers are the lowest cost "entry level" technology used to read bar codes. Most wands look very much like ordinary pens and are designed to be held the same way. Wands usually have no moving parts and rely on the user moving the optical head of the wand over the code to produce the scanning signal for decoding. Most wands are of the so-called "dumb" type, meaning their only function is to convert the optical signal seen at the tip into an analogue electrical signal that is then fed, usually via the attached cable, to the host device for decoding (Wand Interface type).

An extension of the basic wand reader is to build in some decoding and/or memory storage. Such devices are usually described as "smart" or "intelligent" wands. They process the signal before transmitting it to the host (e.g. converting it to an RS232 serial output signal). "Memory" wands serve a similar function but have on-board memory to store the data for later downloading to a host device.

The common feature of all wand devices is that the tip or head of the device must contact and move across the bar code or label. This creates a number of obvious and immediate limitations:

• The surface being read must be suitable for having the wand passed over it and robust enough to survive frequent readings. Codes printed on paper-based materials can suffer wear, leading to reading difficulties.
• The user must be able to get close to the code so they can easily "swipe" it with the wand.
• Very small or very large codes can be difficult for users to scan.
• It takes some practice to develop the "knack" required for good first-time reads; novices sometimes experience difficulties.
• The surface bearing the code must adequately reflect the light/dark differentiation. In an attempt to protect delicate codes, users sometimes place some form of clear plastic protection over them. However, if the plastic itself is too reflective (or too thick), the wand will not be able to get an accurate image from the code.
• Wands really need to be used on codes on a flat surface; reading around the curve of a cylindrical object is either very difficult or impossible.
• Wands are not really suited to "high volume" applications. Apart from wear and tear on the wands themselves, wear and tear on users can be a bigger problem!

Despite these limitations, wands remain a very popular choice for low- volume, close-proximity applications. Low power consumption makes them suitable for attachment to battery-powered handheld devices, and their biggest benefit is, of course, their relatively low cost.