Radiant energy – Ionic separation or analysis – Static field-type ion path-bending selecting means
Patent
1989-01-23
1990-05-15
Perkey, W. B.
Radiant energy
Ionic separation or analysis
Static field-type ion path-bending selecting means
2502017, G03B 300, G01J 120
Patent
active
049262068
ABSTRACT:
A lighting device such as an electronic flash device attachable to a camera body includes first and second light projecting optical systems which project first and second light fluxes for illuminating an object to aid focus detection by a focus detection device. The second light flux spreads at a larger solid angle than the first light flux and illuminates a first distance zone which extends to a closer distance side while covering the whole of a second distance zone illuminated by the first light flux. An optical wedge disposed in the second light projecting optical system deflects a part of the second light flux towards the closer distance side of the first distance zone. Another lighting device includes a single light projecting optical system but it also includes an optical wedge for deflecting a part of a light flux projected by the light projecting optical system to widen a distance zone illuminated by the light flux towards a closer distance. The optical wedge also serves to produce a difference in intensity distribution of the light flux such that the light flux has higher intensity at a part thereof for illuminating a farther distance side of the distance zone than at a part thereof for illuminating a closer distance side of the distance zone. A light source of the light projecting optical system(s) is provided with a conical light reflecter surrounding a light emitting diode to reflect light emitted from side surfaces of the light emitting diode forward.
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Egawa Takeshi
Matsui Tohru
Minolta Camera Kabushiki Kaisha
Perkey W. B.
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