Contact image sensor is an image reading sensor that uses LED as a light source, integrated lens and sensor IC for imaging. It is used as an image reading device in various products because it is easily integrated into the product.
The image sensor market is developing rapidly. At present, the image sensor market demand speed is gradually increasing, which is mainly due to the rapid growth of shipments of digital cameras, camera phones and scanners. With the rapid progress of image sensor technology, its applications are becoming more and more extensive.
The contact image sensor can effectively capture the target in contact with or very close to it. In contrast, a true line scan camera of the kind seen on a microfilm scanner will usually be placed a distance back and will use a lens to focus the light as the object passes underneath. This is usually the case for industrial line scan cameras that take photos of 3D objects from a height.
Contact image sensor module
The contact image sensor module can integrate a light source, lens and image sensor in a compact package. It uses a device principle to convert the optical signal converted from photoelectric to an electronic signal.
Contact image sensor
The contact image sensor has the function of closely arranging the light sensing units. In the application of the scanning instrument, it can directly collect the light information of the scanned original text. Because of its low price and no need for lens groups, a more compact scanner can be manufactured, and the cost is greatly reduced. However, due to the contact type (which must be closer to the original film), only LED light sources can be used, and the depth of field, resolution, and color performance are not as good as CCD, and cannot be used for conveying film scanning.
The contact image sensor module is an IC made of CMOS technology for a sensor array. The length of the array is the same as the original length. The optical route is determined by the CIS main body. The system is small in size, short in optical path, does not need to adjust the optical path, can meet the requirements of small size, simple installation, does not need to adjust the optical path, and solves the problems of contact image signal uniformity and component volume.
The working principle of contact image sensor
Contact image sensor mainly includes lens light source array, rod lens array, CMOS image sensor array and circuit board, protective glass, interface and housing. The components of the contact image sensor are all concentrated in the housing, with compact structure, small volume and light weight. The production of its main components requires a micro-manufacturing process. When the contact image sensor is working, the light emitted by a group of LED light sources is directly directed to the surface of the scanned object (prints, etc.). The self-focusing rod lens array focuses the image on the photoelectric sensor array (usually a MOS device) and converts it into Charge storage.
Different types of position sensor units (contact image sensor pixels) receive different light intensities, and different parts of the scanning surface have different light intensities. The light emission time (charge accumulation time) of each pixel in each read cycle is the same. When the accumulation time is reached, the shift register sequentially controls the analog switch to turn on, and sequentially outputs the electrical signal of each pixel in the form of an analog signal, thereby obtaining the scanned analog image signal.
Contact image sensor
Most fax machines use contact image sensors as image reading components. CIS can also be used in scanners, currency detectors, and train ticketing systems. It can be used to scan various bills, card readers, and resolution. Achieve 1200 DPI. Contact image sensors are widely used in products such as fax machines.
