| 摘要 |
A LIGHTING APPARATUS (1) HAS A CONVEX LENS (11) ARRANGED SO THAT ITS OPTICAL AXIS IS AT AN ANGLE ( ) WITH RESPECT TO THE NORMAL OF AN OBSERVATION PORTION (3A) (E.G., A SEMICONDUCTOR SUBSTRATE OR THE LIKE), WITH A CAMERA (5) ARRANGED IN THE PATH OF THE REFLECTED LIGHT RAYS. WHEN A LIGHT-EMITTING PORTION (13) IS ARRANGED ALONG THE OPTICAL AXIS OF THE LENS (11), A BRIGHT FIELD ILLUMINATION TAKES PLACE. IF A KNOB (29) IS TURNED, THE LIGHT-EMITTING PORTION (13) MOVES ALONG A BALL SCREW (25), THEREBY CHANGING THE ILLUMINATION FROM A BRIGHT FIELD ILLUMINATION TO A DARK FIELD ILLUMINATION. WHEN A KNOB (37) IS TURNED, THE LIGHT EXITING THE LENS (11) WILL DIVERGE IF THE LIGHT-EMITTING PORTION (13) IS MOVED CLOSE TO THE LENS (11), CONVERGE IF THE LIGHT-EMITTING PORTION (13) IS MOVED FAR AWAY FROM THE LENS (11), AND BE PARALLEL IF THE LIGHT-EMITTING PORTION (13) IS POSITIONED AT THE FOCAL POINT OF THE LENS (11). BY CHANGING THE POSITION OF THE LIGHT-EMITTING PORTION (13) IN THIS WAY, IT IS POSSIBLE TO CHANGE THE ILLUMINATING ANGLE AND THE ILLUMINATING ANGLE DISTRIBUTION, AND BY ADJUSTING THE POSITION OF THE LIGHT-EMITTING PORTION (13) IN ACCORDANCE WITH THE OPTICAL CHARACTERISTICS OF THE OBJECT (3), IT IS POSSIBLE TO OBTAIN A HIGH CONTRAST IMAGE. IT IS ALSO POSSIBLE FOR THESE ADJUSTMENTS TO BE CARRIED OUT AUTOMATICALLY BY USING AN ACTUATOR, MICROCOMPUTER OR THE LIKE. (FIG. 3)
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