Abstract:
An electron beam device includes an electron beam source, plural spaced plates having aligned apertures through which an electron beam is directed, an electrostatic focusing arrangement, and plural electrostatically charged deflection plates for deflecting the beam and displacing it over a target surface. The apertures in the spaced plates are of deceasing size in the direction of travel of the electron beam for intercepting the outer periphery of the beam and providing a beam of reduced cross section. The electron beam is simultaneously deflected by the deflection plates and focused by the electrostatic focusing arrangement. The electrostatic focusing arrangement includes first and second focusing elements through which the beam is directed which are disposed along the beamline and adjacent the upper and lower end portions, respectively, of the beam deflection plates. The electron beam device is of small size, permitting plural devices to be arranged in two- and three-dimensional compact matrix arrays for dense electron beam lithography arrangements such as for use in the simultaneous manufacture of large numbers of semiconductor devices to boost the throughput in integrated circuit manufacture inexpensively.
Abstract:
For use in a beam index color cathode ray tube (CRT), a multi-beam group electron gun directs first and second groups of vertically aligned electron beams on respective parallel, horizontally aligned color phosphor stripes on the CRT's display screen. Each group of electron beams includes three beams, one for each of the three primary colors of red, green and blue. The first and second electron beam groups are horizontally offset from one another, with the upper, intermediate and lower electron beams in each group tracing the same horizontal phosphor stripe as the beams scan the display screen and with a time delay provided to synchronize the video information of both electron beam groups. A color video signal is provided either to a respective cathode or to a respective segmented conductive portion containing a beam passing aperture in the electron gun's G1 control grid for individually modulating each beam with color video image information.
Abstract:
An internal resistor within a color cathode ray tube (CRT) is connected to a voltage source and is coupled across a G4 grid and a G6 grid of the CRT's multi-grid quadrupole (QPF) electron gun. De-coupling the G4 grid from the G2 grid in the electron gun's prefocus lens and operating the G4 grid at a higher voltage as used in the gun's high voltage main focus lens moves the equivalent lens of the prefocus and main focus lenses toward the CRT's display screen and reduces electron beam magnification and spot size for improved video image definition and focusing.
Abstract:
In a multi-stage, multi-beam electron gun of the common lens type for use in a color cathode ray tube (CRT), a charged grid in the prefocus lens of the electron gun is provided with three inline asymmetric beam passing apertures. The three asymmetric apertures may be either in the G4 grid, in the upper side of the G3 grid, or on the lower side of the G5 grid, i.e., in facing relation to the G4 grid, or may be incorporated in both the G3 and G5 grids. The small G3-G4 and G4-G5 spacing gives rise to isolation of the electron optic lenses of the two outer electron beams from that of the center electron beam allowing the asymmetric auxiliary apertures to asymmetrically and independently correct for electron beam astigmatism, i.e., the difference between the beam's horizontal and vertical focus voltage, and differences in the focus voltages of the two outer electron beams relative to the center electron beam. Each of the three inline apertures includes a circular center portion with an overlapping (or superimposed) elliptically shaped aperture. The elliptical aperture may be aligned generally vertically or generally horizontally, and the two outer electron beam passing apertures may be larger or smaller in diameter than the center aperture. In the two outer electron beam passing apertures, the superimposed elliptically shaped aperture may be horizontally offset (either outwardly or inwardly relative to the circular center portion) for controlling static convergence of the three electron beams.
Abstract:
An electron gun for use in a cathode ray tube (CRT) includes a cathode, a low voltage beam forming region (BFR), and a high voltage deflection focus lens disposed in the beam deflection region of the CRT's magnetic deflection yoke for simultaneous and coincident focusing and deflection of the electron beam on the CRT's display screen. The deflection lens includes a plurality of first focus grids disposed in the CRT's neck portion including a spaced first pair of grids (G42, G44) having respective beam passing apertures disposed horizontally off-center in opposed directions relative to the electron beam axis, and a second pair of grids (G46, G48) having respective beam passing apertures disposed vertically off-center in opposed directions relative to the axis. Other grids disposed on opposed sides of each of the first and second pair of grids have respective beam passing apertures centered with respect to the electron beam axis and are maintained at a fixed focus voltage. A first dynamic focus correction voltage source (275) and a second dynamic focus correction voltage source (277) which vary with the electron beam deflection are respectively applied to each of the first and second pair of grids for compensating for asymmetric off-axis electron beam defocusing at all points on the CRT's faceplate. This dynamic off-axis defocusing correction is equally applicable in a single beam, monochromatic deflection lens CRT, as well as in a multi-beam, color deflection lens CRT.
Abstract:
An inline electron gun for use in a multi-beam color cathode ray tube (CRT) has a main focus lens for focusing the electron beams on a display screen of the CRT. The main focus lens includes adjacent charged electrodes each having a respective common lens aperture through which the electron beams are directed and which are in facing relation for reducing horizontal spherical aberration of the electron beams on the display screen, where each common lens aperture has a longitudinal axis aligned with the inline electron beams. In one embodiment, each common lens aperture is chain-link-shaped including spaced, vertically enlarged portions, each aligned with a respective electron beam for correcting for vertical spherical aberration. Each adjacent electrode further includes a plurality of auxiliary apertures, each aligned with and passing a respective electron beam. Each auxiliary aperture includes a generally circular center portion and upper and lower slots extending generally vertically therefrom to provide balanced focusing for all of the electron beams as well as to correct for beam astigmatism. The circular center portion of each aperture is adapted to receive a cylindrical electrode support rod, or mandrel, disposed within and aligning the electrodes during electron gun assembly. The three inline auxiliary apertures may have the same diameter, or the two outer apertures may have larger diameters and wider slots than the center aperture in another embodiment. The slots may be vertically centered on the circular center portion of each aperture, or the two outer apertures may have outwardly disposed upper and lower slots in another embodiment.
Abstract:
A multi-beam electron gun for use in a monochrome cathode ray tube (CRT) such as used in a black and white television receiver, a projection television receiver, or a computer monitor includes G1 control and G2 screen grids each having a plurality of vertically aligned apertures for forming electron beams which are deflected in unison across the CRT's display screen to simultaneously trace a plurality of vertically spaced, horizontal scan lines with each display screen sweep. The electron beams are deflected across the screen in a raster-like manner with each beam containing video information for each adjacent scan line. The G1 control grid includes a plurality of discrete conductive portions each including a respective beam passing aperture and each coupled to a respective video signal source, with the video signal sources including memory for storing video signal information for subsequent display. This permits plural adjacent scanning electron beams to simultaneously provide adjacent portions of the same frame of a video image on the display screen. The grids in the main lens portion of the electron gun include vertically elongated, common apertures for focusing each of the electron beams on the display screen, with the electron beams deflected by a vertically oriented, self-convergent magnetic deflection yoke. In another embodiment, each of a plurality of vertically aligned apertures in the G1 grid has an associated cathode, with a respective video signal provided to each of the cathodes for simultaneously writing video information on adjacent horizontal scan lines on the video display.
Abstract:
A multi-beam electron gun for a color cathode ray tube (CRT) includes a plurality of vertically spaced, horizontal inline beams, where each inline array of beams provides the three primary colors of red, green and blue and adjacent inline beam arrays simultaneously trace adjacent horizontal scan lines on the color CRT's display screen. The beams in each horizontal inline array of beams are focused on a common spot on the display screen, with the three beams deflected across the screen in unison. Each inline array of beams is modulated in accordance with that portion of the video image which they form allowing adjacent, vertically spaced inline arrays to write different video image information on the screen in simultaneously forming adjacent portions of the color video image. Simultaneously providing color video image information on more than one horizontal scan line allows for a reduction in horizontal scan frequency and associated magnetic deflection yoke operating criteria, and also increases beam dwell time on the screen's phosphor elements allowing for a reduction in individual beam current without sacrificing video image brightness while improving video image resolution. Individual beams are modulated by providing video drive signals to either segmented conductive portions in the G1 control grid in one embodiment, where each conductive portion includes a beam passing aperture, or in another embodiment to each cathode which is aligned with and directs emitted electrons through an associated aperture in the G1 control grid.
Abstract:
An inline electron gun for use in a multi-beam color cathode ray tube (CRT) has a main focus lens for focusing the electron beams on a display screen of the CRT. The main focus lens includes adjacent charged electrodes each having chain link-type common lens apertures through which the electron beams are directed and which are in facing relation for reducing horizontal spherical aberration of the electron beams on the CRT display screen, where each common lens aperture has a longitudinal axis aligned with the inline electron beams. Each common lens aperture includes spaced, vertically enlarged portions, each aligned with a respective electron beam, for correcting for vertical spherical aberration of the electron beams. Increasing the vertical dimension of that portion of each of the common lens apertures aligned with a respective electron beam reduces the vertical spot size of the electron beam without degrading other electron gun operating characteristics. The chain link-type common lens is defined by a thin peripheral side wall parallel to the beam axis which may also be used in other embodiments such as in combination with facing conventional solid (double side wall) or hollow (single side wall) common lens structures in adjacent electrodes in the main focus lens. The chain link-type common lens aperture may be either disposed in an inwardly directed end wall of the electrode or it may be defined by a straight side wall of the electrode aligned with the electron gun axis.
Abstract:
A limiting aperture disposed in a relatively low voltage and electrostatic field-free region in the main focusing lens portion of an electron gun in a cathode ray tube (CRT) provides reduced electron beam spot size and improved video image contrast and purity in the CRT's display screen. The generally circular limiting aperture is disposed on the axis of the electron gun and within a charged electrode, or grid, within the main focusing lens. The cylindrically shaped, charged grid is elongated along the gun axis and includes generally circular recesses in facing surfaces thereof, which recesses are also disposed on the gun axis and separated by an inner partition defining the limiting aperture. The charged grid is maintained at a voltage V.sub.G, with V.sub.G .ltoreq.0.12 V.sub.A, where V.sub.A is the CRT's anode voltage. With the limiting aperture recessed within the elongated charged electrode, the electrostatic field is essentially zero at the limiting aperture where outer, peripheral electrons in the electron beam are intercepted and removed from the beam for limiting electron beam spot size. The low voltage of the limiting aperture-bearing grid substantially reduces the possibility of secondary electrons reaching the display screen. Most of the secondary electrons are absorbed by the succeeding high voltage grid.