Television 1 Jess UEAB2006 Principles of Color Television

Television 1 Jess UEAB2006 Three Basic Colors of Television Blue Red Green 11 % 30% 59 %

Television 1 Jess UEAB2006 Three Color Characteristics Hue – adjusted color sometime called tint control (from green to red) Brightness – illumination of the picture that includes sharpness of edges including the contrast control Saturation -

Television 1 Jess UEAB2006 Lights 430 Terahertz (430 X 10 Hz) to 750 Terahertz (750 X 10 Hz) 430 Terahertz is considered as a wavelength 750 Terahertz correspond to the color red and the higher frequency 400 nm seen deep blue Some colors do not correspond to any one given wavelength of light (example brown and purple) 12

Television 1 Jess UEAB2006 Electromagnetic Spectrum

Television 1 Jess UEAB2006 Color Mixing When sunlight passes through a glass prism will separate into multitude of color components. The display is called saturation

Television 1 Jess UEAB2006 Subtractive color mixing Subtractive mixing – make use of filtering action that dyes pigments and inks. Ex: pictures, photographs, color movies. Additive mixing – superior to subtractive mixing. Using the primary colors as the base.

Television 1 Jess UEAB2006 Spectrum of White light

Television 1 Jess UEAB2006 Additive Mixing

Television 1 Jess UEAB2006 Result of Additive Mixing

Television 1 Jess UEAB2006 Result of 3 color additive mixing White Pale yellow Graypink Pale green Bluish Green 100% White 50% White 50 % Saturated red 50% Saturated Yellow

Television 1 Jess UEAB2006 Luminance Level Dark yellow producing a shade of gray approaching black Y= 0.59G R B For equal Energy Y = 0.59(1) (1) (1) »=1.00 For 50 % red 100% blue 100% green Y = 0.59G R B »= 0.59(1) (1) (1) »= »=0.85

Television 1 Jess UEAB2006 Object size and color A 23 in television picture tube can show a video signal of 0.5 MHz or less correspond to horizontal picture tube object sizer ranging from 0.34 in or more. Object sizes ranging from 0.34 in to a minimum of 0.12 in corresponding to the half cycle of video frequency of 1.5 MHz. Only two colors orange and cyan can provide complete color reprodution

Television 1 Jess UEAB2006 continuation Luminance signal information has required bandpass from 0 to 4.2 MHZ The narrower the bandwidth of the color information the less complex the color tv system need be.

Television 1 Jess UEAB2006 Color Television Transmission

Television 1 Jess UEAB2006 Matrix Y Color Transmitter

Television 1 Jess UEAB2006 G-Y Matrix (R –Y) + Y = R (B – Y) +Y = B (G – Y) + Y = G

Television 1 Jess UEAB2006 Y color Receiver

Television 1 Jess UEAB2006 Balance Modulator

Television 1 Jess UEAB2006 Color Burst color synchronizing

Television 1 Jess UEAB2006 Phase relationship The amplitude of the composite chrominance signal represents the color Saturation information and its phase corresponds to the actual color of hue information of the picture being transmitted Phasor – a sine and cosine waves can be represented by a straight line.

Television 1 Jess UEAB2006 Three phasors properties Length Speed of counter clockwise rotation Relative angular position

Television 1 Jess UEAB2006 Performance of the chrominance signal Y =0.59G R B =0.599(0) +0.30(0) (0) = 0.41 R –Y = 0.70R – 0.11B– 0.59G =0.70(1) – 0.11(1) – 0.59(1) = 0.59 B – Y 0.89B – 0.30R – 0.59G =0.89(1) – 0.30(1) – 0.59(0) = 0.59

Television 1 Jess UEAB2006 COLOR PHASE ANGLE

Television 1 Jess UEAB2006

Misconvergence

Television 1 Jess UEAB2006

Low green adjustment

Television 1 Jess UEAB2006 High adjustment of blue

Television 1 Jess UEAB2006 Dominant Red missing green

Television 1 Jess UEAB2006 Dominant Blue Missing Green

Television 1 Jess UEAB2006 Missing Red

Television 1 Jess UEAB2006 Too much Blue adjustment

Television 1 Jess UEAB2006 Low red adjustment

Television 1 Jess UEAB2006 Low green and blue adjustment

Television 1 Jess UEAB2006 Low red and green color adjustment