Scanners are electronic devices that capture images from physical objects and convert them into digital formats. This digitized information can then be stored on computers for viewing and further modification using software applications. In the realm of electronic data transmission, scanning is considered a reliable and effective method for transmitting images. The fundamental principle of a scanner involves analyzing an image, reproducing it, and transforming it into a digital image through optical character recognition techniques.
Scanners come in a variety of shapes and sizes, each designed for specific purposes. Here are some of the most popular types of scanners available:
1. Flatbed Scanners
The flatbed scanner is perhaps the most recognizable type. Typically placed on a desk, it features a flip-up top that reveals a glass scanning surface when opened. Flatbeds are available in various sizes, accommodating standard paper sizes up to legal and even larger formats.
Many all-in-one models combine a flatbed scanner with a printer, minimizing desk space requirements. These scanners are excellent for digitizing books, newspaper articles, and even DVD cases for those looking to create digital film libraries.
While some flatbed scanners are suitable for photo scanning, especially those with high resolutions, they are not known for speed. Each item must be manually placed onto the scanner bed before processing. For bulk document scanning, however, flatbed scanners remain a reliable choice.
2. Sheetfed Scanners
As the name suggests, sheetfed scanners operate by feeding documents into a vertical or horizontal slot. Key components include a sheet-feeder, a scanning module, and calibration sheets. While often more expensive than other types, the time saved can justify the investment for users with specific needs.
Unlike flatbed scanners where the sensor and light source move across a stationary glass panel, in sheetfed scanners, the sensor and light source remain fixed. Instead, the document moves through the scanner. This design makes them ideal for scanning single-page documents efficiently. However, their inability to scan thick objects like books is a significant limitation.
The primary advantage of sheetfed scanners is their ability to process multiple documents consecutively without manual page turning. Documents can be loaded into a feeder tray, and the machine automatically pulls each page through for scanning, similar to a photocopier.
3. Photo Scanners
While document scanning doesn’t demand high resolution or color depth, photo scanning does. Many general-purpose scanners can handle photos, eliminating the need for a separate device. However, if the primary goal is digitizing film negatives or slides, a dedicated photo scanner is the optimal choice.
Photo scanners incorporate specialized technology to handle slides and negatives. They often include built-in software for enhancing and restoring old photos.
Epson photo scanners are a prime example of high-quality photo scanners. Although slightly pricier than general scanners or printers, they often include adapters for scanning slides and negatives and offer significantly higher scanning resolutions compared to other scanner types.
4. Handheld Scanners
Handheld scanners differ significantly from sheetfed and flatbed models. Instead of placing documents into the scanner, users manually move the handheld scanner over the item to be scanned. Users glide the scanner across the document’s surface, capturing its details.
These scanners require a steady hand to ensure accurate detail capture. Even slight movements or hand tremors can result in distorted or inaccurate scans. A common example of a handheld scanner is the standard tag scanner used in retail stores to read product prices.
5. Portable Scanners
Portable scanners are compact handheld or small desktop devices designed for scanning on the go. Some are as small as ink pens, while higher-quality portable scanners are slightly larger.
While most portable scanners don’t achieve the high resolution of flatbed scanners, they are well-suited for users who conduct research in libraries or need to scan small documents frequently.
Achieving good quality scans with portable scanners requires practice. However, their advantage lies in their ability to quickly capture information in digital format for later review and organization.
6. Drum Scanners
Drum scanners employ photomultiplier tubes (PMT) to scan images, a different technology from the charge-coupled devices (CCD) used in flatbed scanners. Photomultiplier tubes are highly sensitive vacuum tubes that detect light.
In drum scanning, the image is mounted on a glass cylinder or drum. As a light beam traverses the image, the reflected light is captured by the PMTs and processed. Drum scanners are known for their high resolution, making them ideal for detailed and professional-quality scanning. However, they are less common than flatbed scanners due to their high cost and larger size.
7. Film and Slide Scanners
High-end photo scanners can produce satisfactory results for scanning high-quality 35mm film, negatives, or slides. However, dedicated slide scanners are available specifically for bulk scanning of film products. While image quality may not be the absolute highest, they offer speed and efficiency in processing large quantities of slides.
8. Multifunction Scanner Printers
Many users today opt for multifunction printers, which essentially combine a printer, scanner, and photocopier into a single device. These are suitable for occasional scanning needs or when high resolution is not critical. Multifunction scanners often include fax capabilities as well.
Multifunction scanner/printers are a practical choice for both office and home environments, especially where space is limited. Their software allows users to scan photos or documents. Many are now available in wireless configurations, enabling multiple computers and devices to send and receive scans.
9. Production Scanners
Production scanners operate similarly to flatbed scanners but at significantly faster speeds. They are built for durability and high-volume scanning tasks. These scanners also feature document feeders for quickly processing large batches of documents.
Production scanners are considerably more expensive than flatbed models. They are targeted towards publishing companies and businesses that require daily high-volume document scanning.
10. Specialty Scanners
Specialty scanners are designed for specific tasks such as scanning business cards and receipts. While flatbed, document, or even portable scanners can perform these functions, specialty scanners, like business card scanners, come with software to streamline the processing and organization of these specific scan types.
Technological advancements have provided a wide array of convenient and functional scanners to meet diverse work needs. Scanners are available in various forms and functionalities to suit individual requirements. What type of scanner do you use in your office or home?
Did you know that mobile applications now allow you to scan documents using just your smartphone? Discover more about these interesting mobile scanner apps here.
