1. Field of the Invention
The present invention relates to a deflection yoke for use with a color CRT having an in-line type electron gun.
2. Description of the Related Art
A deflection yoke is mounted on a neck of a color CRT in which three electron guns are incorporated. The deflection yoke is energized to magnetically deflect three electron beams both horizontally and then vertically so as to scan the entire area of the inner surface of the CRT.
The horizontal deflection coil 3 includes two subassemblies, each assembly being substantially in the shape of a saddle. The two subassemblies are aligned in the deflection yoke, vertically and symmetrically with respect to a horizontal axis. Likewise, the vertical deflection coil 4 includes two subassemblies, each assembly being in the shape of a saddle. The two subassemblies are aligned in a space outside of the coil bobbin 2, horizontally and symmetrically with respect to a vertical axis. A ferrite core 5 is disposed in a space outside of the vertical coil 4 so that both the horizontal coil 4 and vertical coil 3 provide magnetic deflection of the three beams with increased efficiency.
A deflection yoke is required to perform two tasks: deflection of three electron-beams horizontally and vertically and convergence of the three beams on the inner surface of the screen of the color CRT. In order to achieve these tasks, the actual deflection yoke is required to generate appropriate magnetic fields, thereby necessitating complex shapes of portions depicted at “A” in
Referring to
Recent CRTs, especially, color picture tubes for a display monitor are used to display high-resolution images that require excellent convergence performance. Convergence performance is determined by the arrangement of the turns of coil in the grooves. With the aforementioned conventional deflection yoke, there is no regularity in the turns of coil placed in the grooves. Thus, the lack of regularity inherently results in variations in convergence that is not negligible. Such a deflection yoke is not suitable for ensuring regularity of turns of coil in the grooves.
Deflection yokes have particularly stringent convergence requirements, for example in the field of a color picture tube for a display monitor. Thus, deflection yokes should have minimal variations in their deflection performance.
Thus, the irregularity of arrangement of a deflection coil accommodated in the aforementioned grooves cannot be neglected. The present invention was made in view of the aforementioned drawbacks of the conventional deflection yoke.
An object of the present invention is to provide a deflection yoke that can be manufactured by the conventional technology and yet has reduced variations in convergence performance.
A deflection yoke apparatus include a saddle-type coil bobbin, first guide grooves, at least second guide groove, at least third guide groove, and a multi-wire conductor. The saddle-type coil bobbin has a front end portion and a rear end portion. The first guide grooves is formed in the inner surface of the coil bobbin and extends across the front end portion and the rear end portion. The at least second guide groove is formed in the front end portion of the coil bobbin. The at least third guide groove is formed in the rear end portion of the coil bobbin. The multi-wire conductor is wound around the coil bobbin, the conductor being routed through the first guide groove, the at least second guide groove, and the third guide groove. The second guide groove and third guide groove has a width in a range of 1.0 to 1.5 times a diameter of the conductor.
The at least one second guide groove may be one of a plurality of second guide grooves aligned in parallel and the at least one third guide groove may be one of a plurality of third guide grooves aligned in parallel.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limiting the present invention, and wherein:
Embodiments of the present invention will be described in detail with reference to the accompanying drawings.
A deflection yoke according to a first embodiment includes a conductor that is wound on a saddle-type coil bobbin having a front portion and a rear portion end. The saddle-shaped coil bobbin has guide grooves formed in an inner surface thereof, the guide grooves extending from the front portion to the rear portion to guide turns of coil. The front portion of the coil bobbin has hook-like projections and another guide grooves that guide the conductor. The rear portion of the coil bobbin has hook-like projections and still another guide grooves for guiding the conductor therein.
In the first embodiment, the distance between the hook-like projections 9 of the front side and the coil bobbin 2 is selected taking the diameter of the conductor into account such that the turns of coil can be regularly laid in the groove 6 of the coil bobbin 2. However, as shown in
In order to solve the problem that a large number of turns of coil are concentrated in layers within the single groove 7, a coil bobbin of a second embodiment has another groove 11.
Referring to
While the invention has been described with respect to the front side of the horizontal deflection yoke, the construction according to the invention can also be applied to the front side and rear side of the vertical deflection coil that are mounted outside of the deflection yoke. The second embodiment has been described with respect to a two-groove configuration, i.e., the groove 7 and groove 11. More grooves may be provided while offering the same advantages and effects.
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art intended to be included within the scope of the following claims.
Number | Date | Country | Kind |
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2001-172045 | Jun 2001 | JP | national |
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Number | Date | Country | |
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20020185956 A1 | Dec 2002 | US |