Tech 9-3 tv

Television (often abbreviated to TV, T.V., or t.v.) is a common telecommunication system for broadcasting and receiving moving pictures and sound over a distance.

All practical television systems use the fundamental idea of scanning an image to produce a time series signal representation. That representation is then transmitted to a device to reverse the scanning process. The final device, the television (or TV set), relies on the human eye to integrate the result into a coherent image.

Electromechanical techniques were developed from the 1900s into the 1920s, progressing from the transmission of still photographs, to live still duotone images, to moving duotone or silhouette images, with each step increasing the sensitivity and speed of the scanning photoelectric cell.

As it is written in the patent: The invention relates to the transmission and reception of colored pictures or images by wire or wireless. Even though the invention was not already adaptable to standard television equipment then in use; the invention was considered easy to adapt to any transmitter or receiver of black and white television equipment.

The elements of a simple television system are: * An image source - this may be a camera for live pick-up of images or VTR or a Film Chain-Telecine-flying spot scanner for transmission of films. * A sound source. * A transmitter, which modulates one or more television signals with both picture and sound information for transmission. * A receiver, which recovers the picture and sound signals from the television broadcast. * A display device, which turns the electrical signals into visible light. * A sound device, which turns electrical signals into sound waves to go along with the picture.

* CRT (cathode-ray tube): The most common screens were direct-view CRTs for up to roughly 100 cm (40 inch) (in 4:3 ratio) and 115 cm (45 inch) ((in 16:9 ratio) diagonals. These are the least expensive, and are a refined technology that can still provide the best overall picture quality value. As they do not have a fixed native resolution, they are capable of displaying sources with different resolutions at the best possible image quality. The frame rate or refresh rate of a typical NTSC format CRT TV is 29.97 Hz, and for the PAL format, 25 Hz, both are scanned with two fields per frame in an interlaced fashion. A typical NTSC broadcast signal's visible portion has an equivalent resolution of about 640x480 pixels. It actually could be slightly higher than that, but the vertical blanking interval (VBI), allows other signals to be carried along with the broadcast. High lead content. * Rear projection: Most very large screen TVs (to 100 inches [254 cm] or more) use projection technology. Three types of projection systems are used in projection TVs: CRT-based, LCD-based, and DLP (reflective micromirror chip) -based. Projection television has been commercially available since the 1970s, but at that time could not match the image sharpness of the CRT; current models are vastly improved, and offer a cost-effective large-screen display. o A variation is a video projector, using similar technology, which projects onto a screen. A modern Philips LCD TV A modern Philips LCD TV * Flat panel (LCD or plasma): Modern advances have brought flat panels to TV that use active matrix LCD or plasma display technology. Flat panel LCDs and plasma displays are as little as 25.4 mm (1 inch) thick and can be hung on a wall like a picture or put over a pedestal. Some models can also be used as computer monitors. * LED technology has become one of the choices for outdoor video and stadium uses, since the advent of bright LEDs and driver circuits. LEDs enable scalable ultra-large flat panel video displays that other technologies may never be able to match in performance.

With high lead content in CRTs, and the rapid diffusion of new, flat-panel display technologies, there is growing concern about electronic waste from discarded televisions. Related occupational health concerns exist, as well, for disassemblers removing copper wiring and other materials from CRTs. Further environmental concerns related to television design and use relate to the devices' increasing electrical energy requirements. [16]

Picture quality was very poor, and the screens were only an inch or so wide and were made up of only...................
These sets used a motor to rotate a metal disk to produce the picture, rather than a picture tube. A neon tube behind the disk provided the light.

By 1930 it was clear that mechanical television systems could never produce the picture quality required for commercial success. Electronic television requires a cathode ray tube (picture tube) to display the picture, and some sort of electronic camera tube to capture the image. The cathode ray tube was the easier of these to develop, but the emergence of electronic television was delayed for years until a suitable camera tube could be developed.

high definition television (HDTV) A broadcast technology in which the number of scan lines of the video image is increased and the size of the pixels decreased (as well as reshaped)--resulting in a, clearer, better defined image.

cathode ray tube (CRT) A television picture tube. The cathode ray excites the pixels to create the video image.

The High-Definition Multimedia Interface (HDMI) is an all-digital audio/video interface capable of transmitting uncompressed streams. HDMI is compatible with High-bandwidth Digital Content Protection (HDCP) Digital Rights Management technology. HDMI provides an interface between any compatible digital audio/video source, such as a set-top box, a DVD player, a PC, a video game console, or an AV receiver and a compatible digital audio and/or video monitor, such as a digital television (DTV). In 2006, HDMI began to appear as a feature on prosumer HDTV camcorders and even high-end digital still cameras.[1][2][3]

PAL, short for Phase Alternating Line, is a colour encoding system used in broadcast television systems in large parts of the world. Other common analogue television systems are SECAM and NTSC.

SECAM, also written SÉCAM (Séquentiel couleur à mémoire, French for "sequential color with memory"), is an analog color television system first used in France.

An RCA jack, also referred to as a phono connector or CINCH/AV connector, is a type of electrical connector that is commonly used in the audio/video market. The name "RCA" derives from the Radio Corporation of America, which introduced the design by the early 1940s to allow phonograph players to be connected to amplifiers.

The F connector is a type of RF connector commonly used for "over the air" terrestrial television, cable television and universally for satellite television and cable modems, usually with RG-6/U cable or (in older installations) with RG-59/U cable. It was invented by Eric Winston in the early 1950’s while working for Jerrold Electronics on their development of cable television.

brand name for the IEEE 1394 interface. It is also known as i.Link (Sony’s name) or IEEE 1394 (although the 1394 standard also defines a backplane interface). It is a personal computer (and digital audio/digital video) serial bus interface standard, offering high-speed communications and isochronous real-time data services. FireWire has replaced Parallel SCSI in many applications, due to lower implementation costs and a simplified, more adaptable cabling system. IEEE 1394 has been adopted as the High Definition Audio-Video Network Alliance (HANA) standard connection interface for A/V component communication and control[citation needed]. FireWire is also available in wireless, fiber optic and coaxial versions using the isochronous protocols.

Separate video, abbreviated S-Video and also known as Y/C (or erroneously, S-VHS and "super video") is an analog video signal that carries the video data as two separate signals (brightness and color), unlike composite video which carries the entire set of signals in one signal line. S-Video, as most commonly implemented, carries high-bandwidth 480i or 576i resolution video, i.e. standard definition video. It does not carry audio on the same cable.

VGA connectors" and their associated cabling are almost always used solely to carry analog component RGBHV (red - green - blue - horizontal sync - vertical sync) video signals along with DDC2 digital clock and data.

The Digital Visual Interface (DVI) is a video interface standard designed to maximize the visual quality of digital display devices such as flat panel LCD computer displays and digital projectors