Samsung Display Devices Co., Ltd.

Samsung Sdi Co., Inc.

Hak-cheol Yang

Neung-yong Yun

Chang-seob Kim

Sang-kyun Kim

Jeong-Nam Kim

Hyoung-wook Jang

Neung-yong Yoon

Hun-chang Kim

A solid dielectric material is installed between the second focus electrode and third focus electrode in a one-pin dynamic electron gun assembly in order to increase capacitance between the two electrodes. The increased capacitance between the two electrodes reduces the voltage Vg between the two electrodes and increases the effective voltage Vd (eff) between the third focus electrode and the fourth focus electrode since Vd&equals;Vg&plus;Vd (eff).

One-pin dynamic electron gun for a cathode ray tube

An electron gun for a color cathode ray tube includes a triode unit, a main lens unit, and first and second auxiliary electrodes. The triode unit includes plural cathodes arrayed in a first direction and first and second electrodes each having corresponding plural electron beam passing holes corresponding to the respective cathodes. The main lens unit finally focuses and accelerates an electron beam and includes a third electrode forming a pre-focus lens with the second electrode. The first auxiliary electrode is coupled to one side surface of the second electrode facing the first electrode. The second auxiliary electrode is coupled to the other side surface of the second electrode facing the third electrode. With this arrangement, a beam spot of uniform size can be formed on the entire surface of a screen.

Cathode ray tube with auxiliary electrodes having a plurality of slots

An electron gun for a color cathode ray tube includes a triode having a cathode, a control electrode, and a screen electrode for producing electron beams; first, second, and third focus electrodes; and a final accelerating electrode sequentially disposed from the screen electrode. A first constant voltage is applied to the screen electrode and the second focus electrode, a second constant voltage higher than the first constant voltage is applied to the first focus electrode and the third focus electrode, and an anode voltage higher than the second constant voltage is applied to the final accelerating electrode, so that electron beams cross from the triode cross between a main lens formed by the third focus electrode and the final accelerating electrode, and an auxiliary lens formed by the first, second, and third focus electrodes. The electron gun produces uniform size electron beam spots over a fluorescent film of a cathode ray tube with reduced spherical aberration.

Electron gun for color cathode ray tube

An electron gun for a color cathode ray tube includes a cathode structure having three electron emitting portions in a field emission array cell. A focus electrode and a final acceleration electrode are sequentially arranged with respect to the cathode structure and form a main lens for focusing electron beams emitted from the three electron emitting portions. The eccentric distance of the electron emitting portions is shorter than the eccentric distance of the electron beam emitting holes in the focus electrode opposite the electron emitting portions. Focus characteristics and convergence characteristics are improved.

A screen for a beam index tube includes a fluorescent surface having a pattern of color stripes respectively producing red, green, and blue light in unit areas within the stripes in response to an incident electron beam and index unit areas regularly arranged in the pattern, the color stripes being arranged side-by-side and along a vertical direction with color unit areas of vertical stripes being in registration along a horizontal direction, each color unit area being spaced in the horizontal and vertical directions from the nearest color unit area by one unit area, and the index unit areas being disposed among the color unit areas and spaced from the nearest index unit area by three unit areas in the horizontal direction and one unit area in the vertical direction. A beam index tube may include the screen in combination with a tube assembly and an electron gun. Since the index unit areas are not spaced from nearest color unit areas, vertical deflection correction of the electron beam is not required and can be omitted. Thus, the picture quality produced is not adversely affected by the earth's magnetic field and manufacturing costs are reduced by avoiding the elements needed for the vertical deflection correction.

Fluorescent screen pattern for beam index tube and beam index tube

A device for driving a directly heated cathode of a cathode ray tube eliminating a delay due to inductance of a transformer. A transformer that produces the heater-heating signal voltage applied to the cathode includes a secondary coil divided into first and second coils. The voltage induced in the first coil is used for the heater-heating voltage and the signal induced in the second coil is synchronized with the voltage induced in the first coil and used as a bias voltage for turning on and off a switching element in synchronization with the heater-heating voltage. The switching element turns on only when the heater-heating signal voltage is applied to a control terminal of the switching element.

Device for driving directly heated cathode of cathode ray tube

A double cross-over type electron gun for a color CRT is provided. The electron gun includes a triode having a cathode, a control electrode and a screen electrode, for generating and controlling an electron beam, a plurality of focus electrodes sequentially disposed adjacent to the triode, for forming at least one auxiliary lens, and a final accelerating electrode disposed adjacent to the focus electrode, for forming a main lens. The electron beam generated by the triode includes a cross-over point in front of the main lens and proximate to the auxiliary lens. At least one of the auxiliary lenses disposed upstream from the main lens is formed as a quadrupole lens so that the position of the cross-over point in the horizontal direction and that in the vertical direction are different from each other. When a dynamic focusing voltage is applied, the image quality at the periphery of a screen can be greatly improved.

Growing community of inventors

Suwon, South Korea

Hak-cheol Yang