Camera

• US 4,809,030 A
• Filed: 09/18/1987
• Issued: 02/28/1989
• Est. Priority Date: 09/24/1986
• Status: Expired due to Term

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Takagi, Tadao, Fukuhara, Toru
• Primary Examiner(s): Perkey, W. B.
• Application Number:
  US07/098,394
• Time in Patent Office: 529 Days
• Field of Search: 354/414-417, 354/420-423, 354/431, 354/432
• US Class Current: 396/161
• CPC Class Codes: G03B 7/08 Control effected solely on the basis of the response, to the intensity of the light received by the camera, of a built-in light-sensitive device
• CPC Class Codes: G03B 7/093 for control of exposure time
• CPC Class Codes: G03B 7/09974 using the film or shutter as sensor light reflecting member
• CPC Class Codes: G03B 7/09979 Multi-zone light measuring
• CPC Class Codes: G03B 7/16 in accordance with both the intensity of the flash source and the distance of the flash source from the object, e.g. in accordance with the "guide number" of the flash bulb and the focusing of the camera
• CPC Class Codes: G03B 7/28 Circuitry to measure or to take account of the object contrast

Abstract

A camera includes producing means for detecting the state of the luminance of the object field and producing a luminance information signal conforming to the detected state of the luminance of the object field, control means for calculating the exposure value for exposure of a film on the basis of the luminance information signal and performing the exposing operation of the film, setting means for setting a comparative level on the basis of the luminance information signal, flash emitting means for emitting flash toward the object field in response to the start of the exposing operation by the control means, means for calculating the integrated value of at least a part of the light from the object field at any time in response to the start of the exposing operation by the control means, and stop means for detecting that the integrated value and the comparative level have assumed a predetermined relation and stopping the flash emitting operation of the flash emitting means.

Claims

1. A camera comprising:

(a) measuring means for dividing an object field to be photographed into a plurality of areas, measuring luminances of at least some of said plurality of areas and producing a plurality of measurement outputs conforming to the luminances of said at least some areas;

(b) producing means for producing a first information signal conforming to a maximum luminance difference and a second information signal conforming to a mean luminance value on the basis of said plurality of measurement outputs, said maximum luminance difference indicating a difference between a maximum value and a minimum value in the measured luminances corresponding to said at least some areas, said mean luminance value indicating a mean value of said measured luminances corresponding to said at least some areas;

(c) control means for calculating an exposure value for exposure of a film on the basis of said plurality of measurement outputs corresponding to said at least some areas, and performing an exposing operation of the film;

(d) memory means in which a plurality of comparative levels are stored;

(e) selecting means for selecting one of said plurality of comparative levels on the basis of said first and second information signals;

(f) flash emitting means for emitting flash toward the object field in response to the start of the exposing operation by said control means;

(g) means for calculating an integrated value of at least a part of light from the object field at a time subsequent to the start of the exposing operation by said control means; and

(h) stop means for detecting that said integrated value and said selected one of said plurality of comparative levels have assumed a predetermined relationship, and stopping the flash emitting operation of said flash emitting means.

2. A camera according to claim 1, wherein said control means has a plurality of states for calculating the exposure value, selects one of said plurality of states on the basis of said first and second information signals and calculates the exposure value on the basis of said plurality of measurement outputs in the selected one state.

3. A camera according to claim 2, wherein said selecting means selects the largest one of said plurality of comparative levels as the value indicated by said second information signal becomes larger when the luminance indicated by said second information signal is larger than a predetermined value.

4. A camera according to claim 3, wherein said control means calculates the exposure value on the basis of different equations in the respective ones of said plurality of states.

5. A camera comprising:

(a) measuring means for dividing an object field to be photographed into a plurality of areas, measuring luminances of at least some of said plurality of areas and producing a plurality of measurement outputs conforming to the luminances of said at least some areas;

(b) producing means for producing a plurality of information signals each of which indicates different information with respect to the luminance distribution of the object field on the basis of said plurality of measurement outputs;

(c) control means for calculating an exposure value for exposure of a film on the basis of said plurality of information signals and said plurality of measurement outputs, and performing an exposing operation of the film on the basis of the calculated exposure value;

(d) determining means for determining a comparative level on the basis of said plurality of information signals;

(e) flash emitting means for emitting flash toward the object field in response to the start of the exposing operation by said control means;

(f) means for calculating an integrated value of at least a part of light from the object field at a time subsequent to the start of the exposing operation by said control means; and

(g) stop means for detecting that said integrated value and said comparative level have assumed a predetermined relationship, and stopping the flash emitting operation of said flash emitting means.

6. A camera according to claim 5, wherein said control means has a plurality of states for calculating the exposure value, selects one of said plurality of states on the basis of said plurality of information signals and calculates the exposure value on the basis of said plurality of measurement outputs in the selected one state.

7. A camera according to claim 6, wherein said plurality of information signals has a signal conforming to a maximum luminance difference indicating a difference between a maximum value and a minimum value in the measured luminances corresponding to said at least some areas.

8. A camera according to claim 7, wherein said plurality of information signals have a signal conforming to a mean luminance value indicating a mean value of said measured luminances corresponding to said at least some areas.

9. A camera comprising:

(a) measuring means for dividing an object field to be photographed into a plurality of areas, measuring luminances of at least some of said plurality of areas and producing a plurality of measurement outputs conforming to the luminance of said at least some areas;

(b) producing means for producing a plurality of information signals each of which indicates different information with respect to the luminance distribution of the object field on the basis of said plurality of measurement outputs;

(c) control means for calculating an exposure value for exposure of a film on the basis of said plurality of information signals and said plurality of measurement outputs, and performing an exposing operation of the film on the basis of the calculated exposure value;

(d) flash emitting means for emitting flash toward the object field in response to the start of the exposing operation by said control means;

(e) means for calculating an integrated value of at least a part of light from the object field at a time subsequent to the start of the exposing operation by said control means;

(f) stop means for detecting that said integrated value and a comparative level have assumed a predetermined relationship, and stopping the flash emitting operation of said flash emitting means; and

(g) changing means for changing said comparative level on the basis of said plurality of information signals.

10. A camera according to claim 9, wherein said control means has a plurality of states for calculating the exposure value, selects one of said plurality of states on the basis of said plurality of information signals and calculates the exposure value on the basis of said plurality of measurement outputs in the selected one state.

11. A camera according to claim 10, wherein said plurality of information signals have a signal conforming to a maximum luminance difference indicating a difference between a maximum value and a minimum value in the measured luminances corresponding to said at least some areas.

12. A camera according to claim 11, wherein said plurality of information signals have a signal conforming to a mean luminance value indicating a mean value of said measured luminances corresponding to said at least some areas.