Camera and system of camera and electronic flash device

• US 5,239,336 A
• Filed: 12/05/1991
• Issued: 08/24/1993
• Est. Priority Date: 12/21/1990
• Status: Expired due to Term

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Sakamoto, Hiroshi, Matsui, Hideki, Yokonuma, Norikazu, Hagiuda, Nobuyoshi, Takayanagi, Ryotaro
• Primary Examiner(s): Adams, Russell E.
• Assistant Examiner(s): NOH, JAE
• Application Number:
  US07/802,604
• Time in Patent Office: 628 Days
• Field of Search: 354/420, 354/416, 354/417, 354/137, 354/138, 354/413
• US Class Current: 396/161
• CPC Class Codes: G03B 7/17 Selection of modes in flash units by exposure control arrangements
• CPC Class Codes: G03B 9/70 with flash-synchronising contacts

Abstract

A camera system includes a camera having a focal plane shutter and an electronic flash device cooperable with the camera. The flash device, which emits light repetitively, has two operating modes. In a first mode, a light emission start signal is synchronized with the start of the exposure of a film exposure area by a leading curtain of the shutter, and a light emission stop signal is synchronized with the end of the exposure of the film exposure area by a trailing curtain of the shutter. In a second mode, the light emission start signal is synchronized with the full exposure of the film exposure area by the leading curtain, and the light emission stop signal is synchronized with the start of shielding of the film exposure area by the trailing curtain.

Claims

1. A camera system including a camera having a focal plane shutter and an electronic flash device cooperable with the camera, comprising:

setting means for setting an exposure time of the shutter;

shutter control means for controlling the drive of a leading curtain and a trailing curtain of the shutter in accordance with the set exposure time;

a light emitting tube;

light emission control means for causing the light emitting tube to repetitively emit light during the exposure time of the shutter;

discrimination means for discriminating the set exposure time;

said discrimination means determining that the run of the trailing curtain of the shutter is started prior to full exposure of a film exposure area by the run of the leading curtain of the shutter in the set exposure time, to output a first discrimination signal, and determining that the run of the trailing curtain of the shutter is started after the full exposure of the film exposure area by the run of the leading curtain of the shutter in the set exposure time, to output a second discrimination signal; and

timing control means for outputting to said light emission control means a start signal to cause said light emitting tube to repetitively emit light and a stop signal to stop the repetitive light emission of said light emitting tube;

said timing control means outputting the light emission start signal substantially in synchronism with the start of the exposure of the film exposure area by the leading curtain and outputting the light emission stop signal substantially in synchronism with the end of the exposure of the film exposure area by the trailing curtain when said first discrimination signal is outputted;

said timing control means outputting the light emission start signal substantially in synchronism with the full exposure of the film exposure area by the leading curtain and outputting the light emission stop signal substantially in synchronism with the start of shielding of the film exposure area by the trailing curtain when said second discrimination signal is outputted.

2. A camera having a focal plane shutter and cooperable with an electronic flash device for repetitively emitting light by a light emitting tube during an exposure time of the focal plane shutter of the camera, comprising:

setting means for setting the exposure time of the shutter;

shutter control means for controlling the drive of a leading curtain and a trailing curtain of the shutter in accordance with the set exposure time;

discrimination means for discriminating the set exposure time;

said discrimination means determining that the run of the trailing curtain of the shutter is started after full exposure of a film exposure area by the run of the leading curtain of the shutter in the set exposure time, to output a discrimination signal; and

timing control means for outputting to said electronic flash device a start signal to cause said light emitting tube to repetitively emit light and a stop signal to stop the repetitive light emission of the light emitting tube;

said timing control means outputting said light emission start signal substantially in synchronism with the full exposure of the film exposure area by the leading curtain and outputting the light emission stop signal substantially in synchronism with the start of shielding of the film exposure area by the trailing curtain when said discrimination signal is outputted.

3. A camera according to claim 2 wherein said discrimination means determines that the run of the trailing curtain of the shutter is started prior to full exposure of the film exposure area by the run of the leading curtain of the shutter in the set exposure time, to output another discrimination signal, and said timing control means outputs the light emission start signal substantially in synchronism with the start of exposure of the film exposure area by the leading curtain and outputs the light emission stop signal substantially in synchronism with the end of exposure of the film exposure area by the trailing curtain when said other discrimination signal is outputted.