US 6,534,935 B1Granted

Color CRT apparatus

AssigneeMatsushita Electric Industrial Co., Ltd.

InventorsHiroshi Sakurai, Etsuji Tagami, Hiromi Wakasono

Life of this patent

Estimating the term…

Loading patent…

Abstract

In a color CRT apparatus in which three electron beams are not superimposed on one point on the screen at a time, a time difference is applied to modulating signals corresponding to the respective electron beams to adjust phase, thus achieving convergence of images, the screen is flat, both a horizontal magnetic deflection field and a vertical magnetic deflection field have uniform magnetic field distribution, paths of both side electron beams and a path of the center electron beam of the three electron beams emitted from electron sources are approximately parallel, and the time difference applied to the modulating signals is set to be approximately constant throughout the screen. Thus, images formed of imaging spots of the three electron beams can be superimposed on the screen with high precision to be matched without causing increased cost.

Claims18

Dependent claims

A color CRT apparatus, comprising a system in which three electron beams, including side electron beams and a center electron beam, emitted from three electron sources arranged in an in-line form in a horizontal direction corresponding to three colors R, G, and B are deflected by a horizontal magnetic deflection field and a vertical magnetic deflection field in a magnetic deflection field area, imaging spots of the three electron beams that are not superimposed on one point on a screen at a time are formed, and according to a time difference in timings at which the three electron beams scan the same one point on the screen, respectively, a time difference is applied to input timings of modulating signals for the respective electron beams to form color images on the screen,

wherein the screen is substantially flat,
both the horizontal magnetic deflection field and the vertical magnetic deflection field have substantially uniform magnetic field distribution,
paths of the side electron beams and a path of the center electron beam are approximately parallel to each other when the electron beams enter the magnetic deflection field area, and
the time difference applied to the input timings of the modulating signals is approximately constant throughout the screen.

1 more element

wherein the screen is approximately flat,
both the horizontal magnetic deflection field and the vertical magnetic deflection field have approximately uniform magnetic field distribution, and
adjustment is made so that the imaging spots of the three electron beams on the screen at a time are positioned continually at a certain interval between respective adjacent two of the imaging spots in a horizontal direction by allowing paths of the side electron beams and a path of the center electron beam to be approximately parallel to each other when the electron beams enter the magnetic deflection field area and the vertical magnetic deflection field is not generated and by increasing, according to strength of the vertical magnetic deflection field, intervals between the paths of the side electron beams and the path of the center electron beam when the electron beams enter the magnetic deflection field area and the vertical magnetic deflection field is generated.

Dependencies are inferred from the claim text.