Image processing and emission systems
The basis for the functioning of video devices are technical and structural solutions and electronic systems, which enable the emission of the image in the form most favorable to the recipient and are able to transform the image accordingly, in order to increase its usability. The use of digital technology has opened up new possibilities for image transformation and the creation of new utility functions, related to its emission.
The basic element of video devices is the screen. The traditional screen is a slice of the sphere (Ball), therefore it is convex. External objects are reflected in it, especially light sources, interfering with the reception of the image. An innovative solution was the introduction by Sony of Super Trinitron screens with a surface constituting a section of a cylinder, i.e. vertical flat screens. The introduction of vertical flattening of the screen also made it possible to use the so-called. slotted shadow mask, located inside the cathode ray tube, instead of a traditional perforated mask, resulting in a sharper and brighter image. The shape of the screen reduced distortion and light reflections, and also enabled the magnification of the viewing angle of the image. Currently, thanks to new technologies and constructions, the so-called. super-flat screens, that provide detailed and clear images with natural colors over the entire screen surface and a very wide viewing angle.
An important step towards improving image quality was the introduction of cathode ray tubes with black coverage, referred to as "black". Thanks to this coating, the screen reduces unwanted light scattering and reflections, giving better contrast and clear, realistic image. Another solution was the introduction of widescreen screens, i.e. screens extended horizontally with a format 16:9 (width-to-height ratio of the screen). This format provides a "cinematic" experience when watching widescreen movies.
The classic way of image emission is based on the use of a cathode ray tube, i.e. the so-called. cathode-ray tube (CRT). Another solution was the use of liquid crystals, which were used to construct the so-called. liquid crystal displejów (LCD). These disclices have become popular due to their use as monochrome digital pointers in watches., calculators, measuring instruments, etc.. Today, LCDs are used as color screens in small TVs, cameras and other video devices, as well as as computer screens (Laptops). For very large screens (with a diagonal of more than 35", i.e.. above 88 Cm) the so-called. optical projection systems. The operation of such a system is based on the use of three high-brightness projection cathode ray tubes, from which one large image is created as a result of passing through a system of special lenticular internal screens. The final image is created directly on the flat cover, made of tinted plastic, constituting an external screen. Some optical projection systems also use LCD.
Currently, digital technology is largely used in video devices. Signals from analog sources (continuous signals), for example. analog signal from the transmitting station, are converted into digital signals (signals in the form of pulses) and binary data (zeros and ones). Such data can be easily machined, enabling the implementation of many functions and effectively affecting the image quality, increasing the stability of the device and extending its life. The processed and processed digital signal is then converted into an analog signal, cathode ray tube control.