INTRODUCTION:-
- Image orthicon camera tube is a type of camera tubes.
- In this camera tube use photoemission.
- It was produced by RCA radio Corporation Of America in 1945.
- it could operate over a wide range of illumination level from Bright light to Dark shadows and produces high picture quality.
- it works on the principle of photoemission.
- It consist three section :-
- Image section.
- Scanning section.
- Multiplier section.
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| Constructional diagram of image orthicon camera tube |
Construction and working section wise:-
Image section:-
In image section when light comes through the convex lens and falls on the face plate that is intrinsic material .Optical image on photocathode convert into charge image then transfer to the target plate which is made up of bismuth or silver.
Photo electrons bundle are emitted from each pixel of the cathode.
Number of photoelectron emitted are proportional to the light incident on photocathode.
These electrons are focused on target at corresponding points, accelerated to thin glass target plate to produce secondary emission,this all process are done in image section.
Scanning section:-
When Dynode of electron gun send the scanning beam to the target plate then the scanned the target plate and return to the multiplier of electron gun.
In this section scanning process are done.
In this section focus coil ,allignment coil ,deflation coil and grid is inbuilt which is works as the vidicon or plumbicon camera tube.
Multiplier section:-
In this section the scanning beam which is comes from faceplate to the the electron gun the multiplier section are multiplied the signal to get a sufficient electron for the purpose of output use.
Applications:-
In industrial applications.
Studios for live shows.
Picture in CCTV.
Advantage:-
High sensitivity.
More length size .
No lag.
Handling a wide range of light values.
S/N ratio is 30dB.
Disadvantage:-
Operation is not easy like vidicon or plumbicon camera tube.
Operation is difficulty.
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