1992-12-28
1994-02-15
Hayes, Monroe H.
3541451, G03B 1503
Patent
active
052871347
ABSTRACT:
An electronic strobe flash apparatus includes a first energizable flash tube arranged to project light in a first direction to directly illuminate a scene, a second energizable flash arrange to project light in a second direction to indirectly illuminate the scene, a battery power supply for providing a source of charging energy, first and second high voltage discharge capacitors coupled to the first and second flash tubes, and electronic control means for providing charging current from the power supply to the first high discharge voltage capacitor until it is charged to a predetermined discharge voltage and for then charging the second high voltage discharge capacitor to the predetermined discharge voltage level. Preferably, the electronic control means includes a single DC/DC converter coupled through a miniaturized relay to the first and second high voltage capacitors to successively charge each under charge control signals provided by a microcontroller. The charging of the first high voltage discharge capacitor to the predetermined high voltage level takes place more rapidly than the charging of the second high voltage discharge capacitor, since the capacitance of the latter exceeds the capacitance of the former. Preferably, if the user of the camera attempts to depress the shutter release button to take a picture, the automatic exposure control system of the camera provides a warning to the user in the event that the second high voltage discharge capacitor is being charged so that the user can either wait until charging is complete or depress the shutter release button further and make an exposure employing only the direct flash unit. The preferred embodiment of the present invention provides for rapid recharging of the low-capacitance, high voltage discharge capacitor of the direct flash unit which may be sufficient under the circumstances and which avoids unnecessary charging of the large capacitance high voltage discharge capacitor of the indirect flash unit and consequent waste of battery energy. Preferably, a ceiling detector provides a control signal that inhibits charging of the indirect flash tube high voltage capacitor.
REFERENCES:
patent: 4242616 (1980-12-01), Takematsu
patent: 4384238 (1983-05-01), Greenwald et al.
patent: 4705373 (1987-11-01), Ohmori
patent: 4748382 (1988-05-01), Walker
patent: 4908552 (1990-03-01), Kumakura
patent: 5049916 (1991-09-01), O'Such et al.
patent: 5055865 (1991-10-01), Fujino et al.
patent: 5136312 (1992-08-01), Weaver et al.
patent: 5146258 (1992-09-01), Bell et al.
Eastman Kodak Company
Hayes Monroe H.
Woods David M.
LandOfFree
Photographic flash apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Photographic flash apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Photographic flash apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1210757