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US 5,689,341 AGranted
LCD panel test system
AssigneeAdvantest Corporation
InventorMasaki Hayashi
Life of this patent
Estimating the term…
Abstract
A LCD test system is able to adjust the differences in focal point lengths caused by chromatic aberration without increasing the size of the camera system and its manufacturing cost. In addition to the conventional structure, the parallel plates are inserted in the pockets of the rotation plate along with each of the four types of optical filters such as red, green, blue and transparency. Therefore, the differences in the focal point lengths due to the chromatic aberration are adjusted without increasing the size of the camera system and its manufacturing cost drastically.
Claims5
An LCD test system, comprising:
- a camera section (19) having a built-in image element for capturing image contrast data of a display panel (10) to be inspected;
- a rotation plate (14) having a plurality of types of optical filters for passing images on said display panel (10) therethrough;
- an optical lens (13) for forming an image on said camera section (19);
- a motor (15) for rotating said plate (14);
- and
- a plurality of parallel plates (21) provided corresponding to said plurality of optical filters for compensating differences in focal point lengths caused by a chromatic aberration of said optical lens, said parallel plates (21) having different thickness from the others depending on colors of said optical filters.
3 more elements
Dependencies are inferred from the claim text.