Color Television Fundamentals
Color Television fundamentals:
Trinitron was Sony’s trade name for its line of aperture grille based CRTs used in television set and computer display monitors. Patent protection on the basic Trinitron design ran out in 1996, and it quickly faced a number of competitors at much lower the prices. The Sony responded by introducing their flat-screen FD trinition designs , which maintained their premier position in the market into early 2000 ‘s. Nevertheless, these designs were surpassed comparatively quickly by plasma and the LCD designs name Trinitron was derived from the Trinity, meaning union of 3, and tron from the electron tube, after way that Trinitron combined 3 separate electron guns of other CRT designs into 1.
NTSC, SECAM and PAL system:
- SECAM is Analog color television system first used in France. A team working at Compagnie Française de Television invented the SECAM. It is historically the first European color television standard.
- The SECAM differs from other color systems by the way the R-Y and B-Y signals are carried.
- SECAM uses the frequency modulation to encode chrominance information on the sub carrier.
- Of several color-image systems for color television available in the world, Japan adopts “NTSC system” which is equally adopted in America and Korea. Hence, video tapes and DVD on other systems, for instance “PAL system,” can’t play well in Japan. In the countries where “PAL system” is adopted that is NTSC system media don’t work. There is also “SECAM system” for images on color television so that roughly, there are three systems. DVD and other media made on the “PAL system” can be reproduced on the “SECOM system” television.
- Second, instead of transmitting the red and the blue information together, it only sends 1 of them at time, and uses information about the other color from preceding line. It uses analog delay line memory device, for storing 1 line of color information. This justifies the “Sequential, With Memory” name.
- Because the SECAM transmits only one color at a time, it is free of the color artifacts present in the NTSC and PAL resulting from the combined transmission of both signals.
CIE color specification system:
- This is one of the most extensively used systems for specifying color but it can be confusing. The purpose of this lab is to demonstrate the principles that Schwartz. It is important to understand the CIE system while it is used to analyze color vision, design color vision tests and explain color vision anomalies.
THE CIE CHROMATICITY DIAGRAM:-
The hue of any wavelength can be specified by the XYZ tristimulus values for that wavelength, but if looking at the numbers they are rather awkward to work with. It would be nice if we could express the mix in terms of a percent that each primary contributes to the total. After all it is the relative proportions of the three primaries in the mix that determine its hue. This can be done by defining three new parameters known as little x, y and z which are based on the X, Y and Z tristimulus values.
LED Color Mixing:
LEDs as with all manufactured products have material and process variations that yield products
with corresponding variation in performance. LEDs are binned and packaged to balance the nature of the manufacturing process with the needs of the lighting industry. Lighting-class LEDs are driven by application requirements and industry standards, including color consistency and color and lumen maintenance.
Question answer section:
Q1: To carry out a full test of the Television what are the performance parameters to be measured?
Ans: To carry out a full test of the Television following performance parameters are measured;
Electro-optic transfer function (gamma curve)
Noise levels and noise distribution
Sensitivity Exposure range, including the effects of black stretch/press and knee
Colour rendering
Infra-red response
Spatial resolution, detail settings and aliasing
Lens/optical aberrations
Temporal/shutter effects
Q2: Demonstrate the Cie Chromaticity diagram?
Ans:Color mixing
• Select two spectral hues (identified by wavelength) to be mixed
• Join them with a line
• Midpoint of line represents the chromaticity coordinates for a 50/50 mix of these two wavelengths.
• Draw a line from white, through the point, to the perimeter. This specifies the dominant wavelength (the hue) for that mix.
• For unequal mixes, the point along the line connecting the 2 wavelengths will be shift closer to the major wavelength, and the line will be divided into segment with lengths that are proportional to the mix.
Q3: Write the measurement of camera?
Ans: Measurements can be made in two ways subjective and an analytical .The Subjective assessment may be rapid and will always reveal whether analytical measurements are needed. They can be used as a confirmation of results and to demonstrate any effects. Analytical measurement takes longer and it requires special equipment and/or
software analysis.
Q4: How to clean plasma and LCD TV?
Ans: Use this high quality microfiber screen cloth with our special formula screen cleaning gel for big screen Television’s, plasma and the LCD screens and Television . This cleaning system is the perfect solution to remove fingerprint and smudges on your screen.For a spotless screen • Streak-free cleaning gel for spotless screens • Lint-free microfiber cloth cleans safely and thoroughly Safely clean screen • Safe, drip-free formula Use over and over again • Lint-free, reusable, washable microfiber cloth
Q5: What is Degaussing ?
Ans: It is the process of decreasing or eliminating a leftover magnetic field . It is possibly named after the gausses unit of magnetism. Due to magnetic hysteresis it is generally not possible to reduce a magnetic field completely to 0, that’s why degaussing typically induces a very small “known” field referred to as the bias. Degaussing was formerly applied to reduce ships’ magnetic signatures during the world war 2. Degaussing is also used to reduce the magnetic fields in CRT monitors and to destroy the data on magnetic media.
GATE Syllabus-
IES Syllabus-
1.IES Syllabus for Electronics and telecomm
2.IES Syllabus for Electrical Engineering
3. IES Syllabus for General Ability
this article gives detailed information about the color scheme. and it gives the basic information about the television and how it works so please all read this article to gain knowledge