Convergence displacement correcting device for projection-type image display apparatus and method thereof
First Claim
Patent Images
1. A projection-type image display apparatus comprising:
- a screen;
a plurality of cathode-ray tubes in juxtaposition each including a picture plane for forming an image of a different monochromatic color, said image being projected on said screen;
a sawtoothed-shaped voltage correction circuit supplied with a regulation voltage for adjusting a static convergence of said image on said screen and a sawtoothed-shaped voltage for correcting a raster shape displayed on the picture plane of one cathode-ray tube in accordance with a projection angle to said screen of said cathode-ray tubes, and outputting a correction sawtoothed-shaped voltage changing in voltage level in accordance with said regulation voltage inputted thereto; and
a raster shape correction circuit supplied with said correction sawtoothed-shaped voltage for correcting the raster shape displayed on said picture plane in accordance with said sawtoothed-shaped voltage in such a manner that the raster shape of said one cathode-ray tube projected on said screen is identical to raster shapes of the other cathode-ray tubes.
2 Assignments
0 Petitions
Accused Products
Abstract
A projection-type image display apparatus, in which a correction raster shape correction circuit is supplied with a sawtoothed-shaped voltage changing in level in accordance with a static convergence regulation voltage for correcting respective raster shapes displayed on the respective picture planes of a plurality of cathode-ray tubes, so that the convergence is not displaced at the peripheral portions of the picture screen at the time of regulating the static convergence.
-
Citations
8 Claims
-
1. A projection-type image display apparatus comprising:
-
a screen; a plurality of cathode-ray tubes in juxtaposition each including a picture plane for forming an image of a different monochromatic color, said image being projected on said screen; a sawtoothed-shaped voltage correction circuit supplied with a regulation voltage for adjusting a static convergence of said image on said screen and a sawtoothed-shaped voltage for correcting a raster shape displayed on the picture plane of one cathode-ray tube in accordance with a projection angle to said screen of said cathode-ray tubes, and outputting a correction sawtoothed-shaped voltage changing in voltage level in accordance with said regulation voltage inputted thereto; and a raster shape correction circuit supplied with said correction sawtoothed-shaped voltage for correcting the raster shape displayed on said picture plane in accordance with said sawtoothed-shaped voltage in such a manner that the raster shape of said one cathode-ray tube projected on said screen is identical to raster shapes of the other cathode-ray tubes. - View Dependent Claims (3, 4, 5, 6)
-
-
2. A projection-type image display apparatus comprising:
-
a screen; three cathode-ray tubes each including a picture plane for forming an image thereon, said cathode-ray tubes being juxtaposed in such a manner that a different three-color monochromatic image is formed on each picture plane and projected on said screen; a plurality of sawtoothed-shaped voltage correction circuits each supplied with a regulation voltage for adjusting a static convergence against said screen of said image and a sawtoothed-shaped voltage for correcting a raster shape displayed on each picture plane of the cathode-ray tubes on sides in accordance with a projection angle of said cathode-ray tubes to said screen, and outputting a correction sawtoothed-shaped voltage changing in voltage level in accordance with said regulation voltage; and a plurality of raster shape correction circuits each supplied with said correction sawtoothed-shaped voltage correspondingly for correcting the raster shape displayed on each picture plane in accordance with said sawtoothed-shaped voltage in such a manner that the raster shape of the cathode-ray tubes projected on said screen on the sides is identical to the raster shape of a central cathode-ray tube.
-
-
7. A method for correcting a convergence displacement in a projection-type image display apparatus including a plurality of cathode-ray tubes in juxtaposition for projecting an image on a screen, each cathode-ray tube having a picture plane for forming the image of a different monochromatic color, comprising the steps of:
-
(a) applying a regular voltage to a voltage correction circuit for adjusting a static convergence of said image on said screen; (b) applying a sawtoothed-shaped voltage to said voltage correction circuit for correcting a raster shape displayed on the picture plane of at least one of the cathode-ray tubes in accordance with a projection angle to said screen of the cathode-ray tubes in accordance with said regular voltage; (c) generating a correction sawtoothed-shaped voltage from said voltage correction circuit changing in voltage level in accordance with said regulation voltage inputted thereto; and (d) applying said correction sawtoothed-shaped voltage to a raster shape correction circuit for correcting said raster shape displayed on said picture plane of said at least one of the cathode-ray tubes in accordance with said sawtoothed-shaped voltage such that the raster shape of said at least one of the cathode-ray tubes projected on said screen matches raster shapes of the other cathode ray tubes. - View Dependent Claims (8)
-
Specification