How Does a Scanner Work?

In the digital age, a well-equipped office contains several electronic devices. A desktop or laptop computer is essential for running office apps and connecting to the internet. Many jobs require multiple monitors with a resolution. There is always a need for hard copies so quality printers are necessary. Keyboards of various types, mice, trackballs, and digital projectors come in handy for many applications. Another handy device is the image scanner, commonly shortened to just “scanner”. Documents, photos, and other hard copies can be photographed digitally and stored as a file on a computer. They can then be used in all kinds of programs and shared through emails or on websites. It’s an amazing device and the way that it works is fascinating.

A Brief History

Scanners de bureau or desktop scanners are found in most offices. They evolved from a 19th Century invention called the pantelegraph. This ingenious machine was developed by the Italian inventor, Giovanni Caselli and entered usage in the 1860s. Essentially an early fax machine, the pantelegraph used electromagnets to move a series of pendulums that traced the outline of text or a drawing. The movements would be transmitted via telegraph to the source location where another set of pendulums would redraw the text or image sent. 

This led to the Belinograph, invented by Edouard Belin in 1913. This refined machine used photocells to scan images and sent them over telephone lines. They were commonly used by news agencies in the 1920s. 

Modern Scanners

Modern scanners are amazing devices that are often incorporated into multifunction printers. Using a process called optical character recognition, photo sensors mounted in a scanner head move across the page and capture words and images, storing them digitally. Through the use of software, the captured image can be transferred to a computer and stored as a digital file. It is then available for use in building a website, digital publication, or social media platform. Scanned images can also be sent through texts or emails. There are several different types of scanners.

Flatbed Scanners

As the name implies, flatbed scanners have a flat sheet of glass upon which the document to be scanned is placed. The lid is closed and a button is pushed, activating the scanner head which moves across the document. This is the most commonly used scanner type. It is found in offices, schools, libraries, and homes. The flatbed is also the type that is often part of a multipurpose printer.

Handheld Scanners 

Handheld scanners are smaller and fully portable. They are handy for projects that require heading out to do research as they can be pulled out to scan newspaper or magazine articles, photos, or any kind of document that can be copied but not taken. 

Sheetfed Scanners

Sheetfed scanners are also smaller than flatbed scanners and are fairly portable. Their usefulness comes from the ability to feed multiple documents into them, one after another, which can save a lot of time. Some sheetfed scanners have automatic feeders that are real-time-savers as the user can just place a stack of documents in the feeder and start the process. The scanner will load and process the entire stack without any more steps taken by the user. 

3D Scanners

3D scanners are more advanced and take measure a series of points on a three-dimensional object in the real world and save them as a digital virtual object. This is very useful in engineering and architecture.

Scanners are remarkable machines that make communication and many tasks in the office or home much easier. Today’s devices have come a long way from Caselli’s pantelegraph. 

Leave a Comment

%d bloggers like this: