The image sensors in scanners are designed to capture images with high resolution, accuracy and reproduce details of scanned objects. They make it possible to scan various types of documents, from simple text to complex graphics and photos, which is used in many fields such as document archiving, graphic design, medicine and many others. Image sensors are a key component of scanners, which make it much easier to transfer and store documents and images in digital form. Their development and technological advances have improved the scanning quality, speed and accessibility of scanners, allowing us to conveniently use digital copies of our documents and images.
Differences in image sensors
In document scanners, we can find two main image sensor technologies:
- CCD - Charged Coupled Device
- CIS - Contact Image Sensor
Both types of sensors have their own distinctive characteristics that will affect the performance of your document scanner.
CCD technology is the longest used in document scanners. Devices that use CCD optical technology work as follows: as the document passes through the scanner, it is illuminated by a light source. While illuminated, the object is photographed through a reduction lens. The resulting image is then projected onto a CCD sensor and processed. The pixels on the CCD sensor act as light-sensitive elements that generate an electrical signal proportional to the intensity of the reflected light. These signals are then processed to create a digital file.
These sensors are characterized by:
- High image quality with low noise,
- wide dynamic range and high color gamut,
- high detail of the recorded image.
An example application is the scanning of slides, graphics or photographs - high quality images.
CIS, or Contact Image Sensor, is a more modern technology that has gained its popularity in recent years. They are more compact and less expensive to manufacture than CCD sensors. A CIS sensor consists of light-sensitive lines arranged along the scanning head. These lines scan a document as it passes through the scanner, and thousands of photodiodes form an image of the document. CIS sensors are more energy-efficient and faster in performance than CCDs, making them popular in portable scanners and multifunction devices.
They are characterized by:
- The possibility of achieving higher speeds,
- low energy consumption,
- low price in production,
- constantly developing technology.
A solution ideally suited for scanning text documents.
Increase the potential of your scanner
It is important to understand that the quality of scanning does not depend solely on the technology of the sensors used in the document scanner itself. Of great importance is the software, which has an invaluable impact on the scanning result. It not only provides convenience and ease of use, but also access to advanced features that allow you to obtain high quality scanned documents and images, edit, organize and share them.