Types of Camera tubes :- vidicon camera tube construction, working principle, Advantage, Disadvantage, Applications

 Camera tubes:-

A camera tube is eye of T.V system. Camera tube is a type of transducer which is used to change the optical image signal into electrical signal. 

It produces many important function which is given below:- 

1. Sensitive to visual light. 

2. Wide dynamic range with respect to light intensity.
3. While viewing multialignment scene its has ability to resolve detail.
4. Output of camera tube is directly proportional to intensity of light.

Types of camera tubes:-

1. Vidicon camera tube 
2. Plumbicon camera tube 
3. Image orthicon camera tube 

Vidicon camera tube:-

Vidicon camera tube was developed by RCA (radio Corporation Of America) in 1950.

Construction:-

•  It has a photoconductive target plate and has an electron beam which are used to focusing and Scanning System.
•  The photoconductive material are made up of antimony trisulphate.

• The input light signal passes through a convex lens system and is incident on a face plate made up of optically flat glass.
• The light from faceplate falls on the target plate which has made up of two layer fixing a light is a thin coating of tin oxide which is a transparent to light and a good conductor of electricity this layer is called signal plate.

• The back layer of target plate is coated with antimony trisulphate semiconductor which is like a insulator material in absence of light.
• The target plate is scanned by electron beam which is produced by electron gun it consisting cathode.
• Accelerating grid and control grid helps to not be distracted.
• The focus grid slow down the electron .
• Deflation coil not to do distracted the beam.
• Allignment coil allingh the beam to axis of tube .

Working principle:-

It it works on the principle of photoconduction 

the signal plate is kept positive by external voltage source of supply.

when light falls on plate produces free electron in the material these electron migrate to positive signal plate attach behind deficiency on semiconductor material .

Towards gun side the insufficiency of electron will be proportional to number of free electron produces by the light and migrated to the signal plate that insufficiency of electron is full filled by electron produced by electron gun.

Advantage:- 

• Easy operation. 
• Cost cheaper.
• Small in size.
• Light weighted.
• It provides good sensitive. 
• Better SNR than orthicon camera tube.

Disadvantage:-

• Dark current. 
• Image lag.

Applications:-

• Outdoor recording. 
• Domestic recording. 
• Used in tv system. 

Question:- 

What is Kell factor ?

Here we get some knowledge on this topic 

●Introduction of television system

●Monochrome TV Transmitter ,Block diagram of monochrome 

●Propogation of TV signal with its types of method