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CPT

Structure of CPT

Structure of CPT image

Currently, Color Braun Tube of Shadow Mask type used in general consists of phosphor layer coated and printed inside a panel of glass instruments (panel/funnel), shadow mask and electron gun. From outside voltage is applied to the electron gun and the heater generates heat and thermal electrons of the cathode discharge. It controls, accelerates and converges the grid which causes electron beam to reach and radiate the phosphor layer. This is how the image on the screen are produced.

Principle of CPT

Principle of CPT  image

When the electron beams that electron gun generates pass through a pair of right-angled and aligned plates or coils of deflection, they are deflected by signal voltage applied to deflection plates or coils from the outside and locus on the phosphor layer moves up and down, right and left drawing images. Deflecting methods of electron beam are divided into electrostatic deflection and electromagnetic deflection. Electrostatic deflection is this: to supply deflection voltage between two deflection plates and deflect electron beams by electric field. It has smaller deflection angle and higher frequency, compared to electromagnetic deflection. But due to high frequency it is usually used for Braun Tube of observation specific use. Electromagnetic deflection is this: to flow electric current to the deflection coil installed to the neck of Braun Tube and deflect electron beams by this magnetic field