Flash synchronizing device

• US 5,291,237 A
• Filed: 04/24/1992
• Issued: 03/01/1994
• Est. Priority Date: 04/25/1991
• Status: Expired due to Fees

• Current Assignee: Seiko Precision Incorporated (Seiko Group Corp.)
• Original Assignee: Seikosha Co., Ltd.
• Inventors: Yamazaki, Hiroshi, Nakajima, Yuji, Aoyama, Tomihiko, Imano, Seiichi, Hayakawa, Teruyo, Tagami, Shigeru
• Primary Examiner(s): Gellner, Michael L.
• Assistant Examiner(s): NOH, JAE
• Application Number:
  US07/874,285
• Time in Patent Office: 676 Days
• Field of Search: 354/129, 354/435, 354/441, 354/446, 354/412, 354/420, 354/423, 354/422, 354/416, 354/413
• US Class Current: 396/67
• CPC Class Codes: G03B 7/095 for control of aperture
• CPC Class Codes: G03B 7/17 Selection of modes in flash units by exposure control arrangements

Abstract

A camera has a shutter which may also constitute a diaphragm. In a multi-flash mode the shutter selectively has a maximum aperture at an onset or at the end of the time base. The flash occurs in synchronism with a shutter waveform shaped by this aperture area and a time base element. In a second embodiment, a second diaphragm setting circuit is provided, in diaphragm priority photography, for computing a measurement value of a distance to a subject and a second diaphragm value from the guide number during an emission of flashed light. The diaphragm is set to the computed second diaphragm value, ad an electronic flash is energized with a desired aperture area. The diaphragm is set to an initial value to effect the photography at a time other than during the emission of flashed light. A timing circuit may be provided for setting the diaphragm to the second diaphragm value. The aperture area may be increased or decreased for diaphragm matching with the quantity of flashed light and the distance to the subject during diaphragm priority flash photography.

Claims

1. A flash synchronizing device comprising a shutter serving as a diaphragm, a multi-flash means for effecting a plurality of flashes during a period from a start of a single exposure by said shutter to the end thereof, means for setting said diaphragm to a series of different diaphragm values during said period, including a maximum diaphragm value, and a maximum diaphragm value synchronizing flash means for synchronizing one of the flashes of said multi-flash means with the time of occurrence of said maximum diaphragm value of said series during said period, at least one other of said plurality of flashes occurring at a time other than the time of occurrence of said maximum diaphragm value.

2. In a flash synchronizing device comprising a photometric means for measuring a brightness of a subject, a focusing means for measuring the distance to said subject, an exposure quantity setting means for setting an exposure quantity from a first diaphragm value obtained by said photometric means or predetermined by a user, a flash control means for operating an electronic flash a first time during a period from a start of a single exposure by the shutter to the end thereof, the improvement wherein said device further comprises a second diaphragm setting means for computing a second diaphragm value from the distance measured by said focusing means and from a light quantity of said electronic flash and for setting said second diaphragm value during said period, means for outputting the second diaphragm value to said exposure quantity setting means, and means for operating with flash control means a second time in synchronization with the time of occurrence of said second diaphragm value during said period.

5. The flash synchronizing device of claim 2 wherein said means for setting said second diaphragm value comprises means for setting a diaphragm value that is greater than all other diaphragm values during said period.

6. The flash synchronizing device of claim 5 wherein said means for setting said second diaphragm value comprises means for setting said second diaphragm value to occur at the start of said period.

7. The flash synchronizing device of claim 5 wherein said means for setting said second diaphragm value comprises means for setting said second diaphragm value to occur at the end of said period.

8. The flash synchronizing device of claim 2 wherein said means for setting said second diaphragm value comprises means for setting said second diaphragm value to be less than other diaphragm values during said period.

3. A flash synchronizing device comprising a shutter serving as a diaphragm, a multi-flash means for effecting a plurality of flashes during a period from a start of a single exposure by said shutter to the end thereof, means for setting said diaphragm to a series of different diaphragm values during said period, including a maximum diaphragm value, and a maximum diaphragm value synchronizing flash means for synchronizing one of the flashes of said multi-flash means with the time of occurrence of said maximum diaphragm value of said series during said period, at least one other of said plurality of flashes occurring at a time other than the time of occurrence of said maximum diaphragm value, said means for setting said diaphragm comprising means for setting said diaphragm to said maximum value at the beginning of said period, whereby said one flash occurs at the beginning of said period.

4. A flash synchronizing device comprising a shutter serving as a diaphragm, a multi-flash means for effecting a plurality of flashes during a period from a start of a single exposure by said shutter to the end thereof, means for setting said diaphragm to a series of different diaphragm values during said period, including a maximum diaphragm value, and a maximum diaphragm value synchronizing flash means for synchronizing one of the flashes of said multi-flash means with the time of occurrence of said maximum diaphragm value of said series during said period, at least one other of said plurality of flashes occurring at a time other than the time of occurrence of said maximum diaphragm value, said means for setting said diaphragm comprising means for setting said diaphragm to said maximum value at the end of said period, whereby said one flash occurs at the end of said period.

9. In a flash synchronizing device for a camera having a shutter that also serves as a diaphragm, means for opening said shutter and controlling the diaphragm value thereof from the start of an exposure to the end thereof, a flash means, and means for controlling said flash means to produce a flash during said exposure, the improvement wherein said means for opening and controlling said shutter comprises means for controlling the diaphragm value to have a plurality of different values during said exposure, and said means for controlling said flash means comprises means for synchronizing said flash with the occurrence of a predetermined one of said diaphragm values or of a diaphragm value predetermined by a user and means for controlling said flash means to flash at another time during said exposure at which the diaphragm value is different than said predetermined one value.

10. The flash synchronizing device of claim 9 wherein said means for controlling said diaphragm comprises means for setting said predetermined one of said diaphragm values to have a maximum value greater than all other diaphragm values thereof during said exposure.

13. The flash synchronizing device of claim 9 wherein said camera has a photometric means for measuring brightness of a subject and a focusing means for measuring the distance to said subject, said means for opening and controlling said shutter comprising means for setting said diaphragm to a first diaphragm value during a first part of said exposure, means for setting said diaphragm to a second diaphragm value during another part of said exposure, said second diaphragm value being dependent upon the distance measured by said focusing means or set by a user and the light quantity of said flash means, said means for controlling said flash means comprising means for synchronizing said flash when said diaphragm is set to said second diaphragm value.

14. The flash synchronizing device of claim 13 wherein said first diaphragm value is less than said second diaphragm value.

15. The flash synchronizing device of claim 13 wherein said first diaphragm value is greater than said second diaphragm value.

11. In a flash synchronizing device for a camera having a shutter that also serves as a diaphragm, means for opening said shutter and controlling the diaphragm value thereof from the start of an exposure to the end thereof, a flash means, and means for controlling said flash means to produce a flash during said exposure, the improvement wherein said means for opening and controlling said shuttered comprises means for controlling the diaphragm value to have a plurality of different values during said exposure, and said means for controlling said flash means comprises means for synchronizing said flash with the occurrence of a predetermined one of said diaphragm values or of a diaphragm value predetermined by a user and means for controlling said flash means to flash at another time during said exposure at which the diaphragm value is different than said predetermined one value, said means for controlling said diaphragm comprises means for setting said predetermined one of said diaphragm values to have a maximum value greater than all other diaphragm values thereof during said exposure, said predetermined one of said diaphragm values occurring at the start of said exposure.

12. In a flash synchronizing device for a camera having a shutter that also serves as a diaphragm, means for opening said shutter and controlling the diaphragm value thereof from the start of an exposure to the end thereof, a flash means, and means for controlling said flash means to produce a flash during said exposure, the improvement wherein said means for opening and controlling said shutter comprises means for controlling the diaphragm value to have a plurality of different values during said exposure, and said means for controlling said flash means comprises means for synchronizing said flash with the occurrence of a predetermined one of said diaphragm values or of a diaphragm value predetermined by a user and means for controlling said flash means to flash at another time during said exposure at which the diaphragm value is different than said predetermined one value, said means for controlling said diaphragm comprises means for setting said predetermined one of said diaphragm values to have a maximum value greater than all other diaphragm values thereof during said exposure, said predetermined one of said diaphragm values occurring at the end of said exposure.