Date post: | 16-Dec-2014 |
Category: |
Education |
Upload: | pravin-shirke |
View: | 2,372 times |
Download: | 1 times |
TV Transmitter&
Receiver
By: Shirke P.Y.
2 Prof.Shirke P.Y.
Basic Monochrome Television Transmitter
3 Prof.Shirke P.Y.
Basic Monochrome Television Receiver
TV Camera Heart of a TV camera is a Camera tube Camera tube – converts optical information into corresponding
electrical signal Amplitude proportional to brightness Optical image is focused by a lens assembly to a rectangular glass face-
plate Transparent conductive coating at the inner side of the glass face-plate On which is laid a thin layer of photoconductive material – having a
very high resistance when no light falls on it. Resistance decreases when the intensity increases Electron beam – used to pick up the picture information available on
the target plate in terms of varying resistance Beam is formed by an electron gun – deflected by a pair of deflection
coils kept mutually perpendicular on the glass plate - to achieve scanning of the entire target area
04/10/2023sk-mes-vkm4
Prof.Shirke P.Y.5
Vidicon: Improvement of contrast
Improvement of signal to noise ratio
High image lag
Plumbicon Lower image lag (follow up of organ motions)
Higher quantum noise level
Solid state camera based on CCD Digital fluoroscopy spot films are limited in resolution, since they depend on
the TV camera .
Types of Camera Pick Up Tube
6
Camera tube have a diameter of approximately 1 inch and a length of 6 inches.
7 Prof.Shirke P.Y.
Simplified cross-sectional view of aVidicon TV camera tube
Prof.Shirke P.Y.8
Vidicon
Prof.Shirke P.Y.9
Working of Vidicon
Prof.Shirke P.Y.10
Vidicon Target & Equivalent ckt of Pixel
11 Prof.Shirke P.Y.
Application of vidicon
Close circuit TV system Earlier type of vidicon were used only where
there was no fast movement , because of inherent lag
Prof.Shirke P.Y.12
Dark Current
Vidicon Lag
Beam Lag
Photoconductive Lag
Persistence Lag
Characteristic of Vidicon
Prof.Shirke P.Y.13
Lower image lag.It has fast response and produce high quality pictures at low
light level.It has small size and light weight and has low power operating
characteristics .It is similar to vidicon tube except small change in target plate
Plumbicon
14 Prof.Shirke P.Y.
Plumbicon
Prof.Shirke P.Y.15
Plumbicon Target & Equivalent ckt of Pixel
Prof.Shirke P.Y.16
Solid state camera based on CCD
Prof.Shirke P.Y.17
Solid state camera based on CCD Equivalent ckt
•Charge-Coupled Devices (CCDs)
• 1980s CCD were developed and replaced TV tubes and miniaturized imaging devices.
• Light photons enter the silicon layer, ionization of the light separates the e-. A layer of microscopic electrodes beneath the silicon acts as a ground for the freed electrons. Movement of charges can be measured by a circuit.
18
Each electrode is connected to a storage capacitor (TFT)
19 Prof.Shirke P.Y.
Colour Science
20 Prof.Shirke P.Y.
Colour Camera tube
21 Prof.Shirke P.Y.
Colour Camera tube
22 Prof.Shirke P.Y.
Picture Tube
23 Prof.Shirke P.Y.
Construction of picture tube
24 Prof.Shirke P.Y.
What is inside picture tube ?
25 Prof.Shirke P.Y.
•Monochrome Picture Tube
26 Prof.Shirke P.Y.
•DEFLECTION YOKEIt may be noted that a perpendicular displacement results because the magnetic field due to each coil reacts with the magnetic field of the electron beam to produce a force that deflects the electrons at right angles to both the beam axis and the deflection field.
27 Prof.Shirke P.Y.
•Deflection Yoke
28 Prof.Shirke P.Y.
PARTS AND WORK PRINCIPLE CRT COLOURED
1. Electron guns
2. Electron beams
3. Focusing coils
4. Deflection coils
5. Anode
6. Mask
7. Phosphor layers
8. Close-up of the phosphor
Parts CRT colour
29 Prof.Shirke P.Y.
•Delta-gun colour picture tube
(a) guns viewed from the base (b) electron beams, shadow mask and dot-triad phosphor screen (c) showing application of ‘Y’ and colour difference signals between the cathodes and control grids
30 Prof.Shirke P.Y.
The screen has a number of phosphorus that will be fluorescent when exposed to fire electrons produced by electron gun.
This electron beam be turned by magnetic field that controlled by vertical spool and horizontal (spool yoke).
Magnified view of a shadow mask color CRT
31 Prof.Shirke P.Y.
PRECISION-IN-LINE (P.I.L.) COLOUR PICTURE TUBE
(a) in-line guns (b) electron beams, aperture grille and striped three colour phosphor screen(c) mountings on neck and bowl of
the tube.
32 Prof.Shirke P.Y.
Electron at shoot off and will hit dots phosphor will produce bright light and can be seen in the screen.
Tube also have mask color, to place phosphor's dots so correct electron beams.
There 3 circles phosphor that is red, blue and green. when described based on sequence the colour, so seen to like picture.
Magnified view of an aperture grille color CRT
33 Prof.Shirke P.Y.
Basic Monochrome Television Transmitter
34 Prof.Shirke P.Y.
Monochrome TV Transmitter
35 Prof.Shirke P.Y.
Basic Monochrome Television Receiver
36 Prof.Shirke P.Y.
Monochrome Television Receiver
37 Prof.Shirke P.Y.
• 12190.pdf
https://www.google.co.in/search?client=firefox-a&rls=org.mozilla:en-US:official&channel=np&q=internet+port&bav=on.2,or.r_qf.&bvm=bv.52434380,d.bmk,pv.xjs.s.en_US.RJfod4swqLE.O&biw=1024&bih=598&dpr=1&um=1&ie=UTF-8&hl=en&tbm=isch&source=og&sa=N&tab=wi&ei=vCZBUv2OBI3GrAexm4CgDA#facrc=_&imgdii=X9uUmFeSlZIIQM%3A%3BmnxgF7FKu3TxVM%3BX9uUmFeSlZIIQM%3A&imgrc=X9uUmFeSlZIIQM%3A%3BfwewdAt_SKyNoM%3Bhttp%253A%252F%252Fhomepages.wmich.edu%252F~s5lu%252Fimages%252Frouter-connect-computer.jpg%3Bhttp%253A%252F%252Fhomepages.wmich.edu%252F~s5lu%252Fwinxp%252Fwinxp_network.html%3B500%3B379
38 Prof.Shirke P.Y.
39 Prof.Shirke P.Y.
40 Prof.Shirke P.Y.