| 摘要 |
PURPOSE:To facilitate the control of optical system for a projection type television device, by irradiating a test pattern to a target from outside and forming an image of the pattern on a screen. CONSTITUTION:The light delivered from a laser beam source 14 is deflected toward the XY direction by a light deflecting device 15 and projected on a target 3 of a cathode-ray tube 1 through a film 18 via an optical lens group 19 and a mirror 20. A compensating matter 11 is previously removed from a supporter 13, and a luminous point is formed at the center of the target 13 by means of the film 18 having a spot type pattern at its center. Then a valve 9 is fixed. A screen 21 is moved back and forth to perform the focal adjustment to the luminous point. Thereafter, the film 18 having a pattern of cross hatch, etc. is used to fix temporarily the matter 11 to the supporter 13, and the matter 11 is displaced to control the spherical aberration. Thus the matter 11 is fixed finally. In such way, the control is facilitated for an optical system. |
