The 6 Best Pen Scanners
A Brief History Of The Scanners
It's a little hard to believe, but the first image scanner technically dates back to the 1860s. The freestanding device known as the panetelegraph was invented by Italian physicist Giovani Caselli in the latter half of the 19th century, with the first prototype presented to the Grand Duke of Tuscany in 1856. It came into popular commercial use in the following decade after additional development under the guidance of a few French inventors. Widely considered the precursor to the modern day fax machine, the pantelegraph could transmit images over a standard telegraph wire. On the receiving end, an inked stylus would produce a copy of the transmitted image.
The next great advancement in scanning technology arrived in 1913. Édouard Belin's Belinograph used a device called a photocell to record images and transmit them over standard phone lines, a technology that was eventually picked up by news media organizations including the Associated Press. While the first prototypes worked quite slowly, by the 1930s, the latest versions could ingest and transmit a full letter-sized page in just one minute. That same decade, the first portable iterations of these devices were developed. This was a major advancement for field reporting, as photographers could transmit images from anywhere with a phone line. Commercially, this technology came to be known as "wirephoto," and was actually in wide use until the early 1990s.
These early scanning technologies were focused more on transmission than on digitizing images, as they predate computer storage. The flatbed scanner, which uses the same technology found in pen scanners and other handheld and portable scanning devices, was invented in the 1970s by American computer scientist Ray Kurzweil. Kurzweil's invention was initially intended as a reading machine for the blind, and it relied on optical character recognition technology to turn printed text into something that could be read aloud by a computer.
While Kurzweil's inventions laid the groundwork for most of today's commercial scanners, it took several decades for the technology to find its way into portable machines. By the early 1990s, the first handheld scanners reached the market. Users could drag the devices across images or passages of text, and a computer would stitch the resulting images together to re-create the full page.
Today, flatbed scanners can be found in many homes and are often built into printers. Portable scanners, though less popular, have come a long way, as well, and, for the most part, don't require an external computer to stitch together composite images of the media they capture.
How Scanning Technology Works
Most modern scanners rely on a lens, a series of mirrors, or a CCD, in order to create digital versions of printed media. Though the method of capture changes slightly depending on what style of scanner you're using, these basic components remain the same.
In a flatbed scanner, a beam of light moves across the surface of the object to be scanned, which is usually protected by a pane of glass. The light reflects off of the object and onto the first of several mirrors that work in tandem to send that reflection into the lens. While the light appears to move continuously, the lens is actually capturing a series of tiny images, one after another. Each of these images is only one small part of the whole, but, because they are collected in rapid succession, the process of scanning an entire letter-sized document can happen in as little as a few seconds, depending on the level of detail being captured.
The lens directs each tiny image onto the CCD, which is comprised of a group of light sensitive diodes called photosites. Each one measures the intensity of the light that strikes it, and emits an electric charge of corresponding strength. For color scans, this process happens three times over, with separate passes for red, blue, and green light. This collection of charges of varying intensities is then converted to a digital map of sorts, which is in turn interpreted by imaging software as pixels. Each of these small groups of pixels is stitched together to form a composite image when the scan is complete using a set of standards established in 1992 called TWAIN.
Pen scanners work virtually this exact same way, except that instead of the light moving across the surface of the object mechanically, the entire scanning device is moved manually by the user. Since handheld movement is inherently inconsistent, pen scans are subject to some level of distortion, though most contemporary models come with software to mitigate that issue.
Some Good Uses For Your Newest Gadget
Depending on what type of pen scanner you're in the market for, there are a host of opportunities to put your new gadget to work, some more obvious than others.
Perhaps the most common need for pen scanners comes from those in research-based fields who need to search through printed material like books, magazines, and archives that can't be removed from where they're kept on file. A pen scanner allows you to easily save excerpts or even full pages of text, so you can take them with you and keep them organized for citation purposes.
Many of today's pen scanners come with built-in character recognition software, which allows them to ingest printed images of text and output a version that's editable in any word processor. This is great alternative to smart notebooks for those looking to turn handwritten pages into text that can be formatted on a computer and shared digitally.
Some portable scanners are not limited to text-based application. These tend to be wand-style models, with sensors that span the length of the devices. Scanners of this nature are perfect for digitizing full-page images or pages with images and text side-by-side. If you're an academic or frequent library-goer, this can save you a great deal of time over making photocopies or using flatbed scanners, which can be slow and may come with fees for use. They're also great for oversized books and other media that are too large for most flatbeds or those with tight bindings that can be damaged in the process.