Method of photographing by varying flash trigger time and camera adopting the same

• US 20040247305A1
• Filed: 04/14/2004
• Published: 12/09/2004
• Est. Priority Date: 06/04/2003
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Techwin Co., Ltd. (Hanwha Corporation)
• Inventors: Lee, Jin-gi, Lim, Jae-chung
• Granted Patent: US 6,952,525 B2
• Time in Patent Office: Days
• US Class Current: 396/61
• CPC Class Codes: G03B 15/05 Combinations of cameras with electronic flash apparatus; Electronic flash units
• CPC Class Codes: G03B 2215/05 Combinations of cameras with electronic flash units

Abstract

Provided herein is a method of photographing in a camera having a flash and a distance measurement unit to measure a distance from the camera to the object, which includes determining whether instructions to perform consecutive photograph are given, measuring a distance from the camera to the object, if consecutive shooting instructions are given, and determining a flash trigger time according to the result of measuring the distance, emitting a flash for the determined flash trigger time while photographing is performed, and performing the measurement and determination operation, if consecutive shooting is not completed.

Claims

1. A method for taking photographs, the method comprising:

determining whether consecutive photographs are to be taken;

if it is determined that consecutive photographs are to be taken, performing further steps comprising

measuring a distance from the camera to the object,

determining a flash trigger time based on the measured the distance;

emitting a flash for the determined flash trigger time while photographing the object; and

repeating the steps of measuring a distance and determining a flash trigger time until there are no further consecutive photographs to be taken.

2. The method of claim 1, further comprising:

determining whether there is a low brightness environment; and

performing the steps of measuring a distance and determining a flash trigger time based on the low brightness environment determination.

3. The method of claim 2, wherein the step of determining a flash trigger time comprises determining the flash trigger time based on a step function of the measured distance, wherein the step function includes at least two steps.

4. The method of claim 1, wherein, the step of determining a flash trigger time comprises determining the flash trigger time by applying a predetermined function to the measured distance.

5. A method of photographing in a consecutive mode by using a flash in a camera having the flash and a distance measurement unit to measure a distance from the camera to an object, the method comprising:

determining the distance from the camera to the object in a first frame;

determining the distance from the camera to the object in a second frame; and

varying the flash trigger time according to whether the distance from the camera to the object is the same in first frame and the second frame.

6. The method of claim 5, further comprising:

determining whether instructions to take a photograph have been given;

if it is determined that instructions to take a photograph have been given, taking a first photograph while emitting a flash during a flash trigger time T1;

determining whether a consecutive shooting is to be performed;

if it is determined that consecutive shooting is to be performed, determining a flash trigger time T2 corrected according to a change in the distance from the camera to the object; and

taking a second photograph while emitting a flash during the flash trigger time T2.

7. The method of claim 6, further comprising:

measuring a distance L1 from the camera to the object; and

determining the flash trigger time T1 according to the measured distance L1.

8. The method of claim 7, wherein the flash trigger time T1 is determined based on a step function of the measured distance L1, the step function having at least two steps.

9. The method of claim 7, wherein the flash trigger time T1 is determined by applying a predetermined function to the distance L1.

10. The method of claim 6, further comprising:

continuously determining whether photographing instructions are given;

measuring a distance L2 from the camera to the object;

determining whether the distance L2 is the same as the distance L1 in the preceding frame;

if the distance L2 is not the same as the distance L1 in the preceding frame, photographing while emitting a flash during a predetermined flash trigger time T1; and

correcting the flash trigger time, if the distance L2 is the same as the preceding frame.

11. The method of claim 10, wherein the corrected flash trigger time T2 is determined as a step function of the distance L2.

12. The method of claim 10, wherein the corrected flash trigger time T2 is determined by applying a predetermined function to the distance L2.

13. The method of claim 10, further comprising increasing a CCD sensitivity gain width by Δ

EV, if the distance L2 is the same as the preceding frame.

14. The method of claim 6, further comprising:

determining whether photographing instructions have been given;

if it is determined that photographing instructions have been given, determining whether there is a low brightness environment;

if it is determined that there is a low brightness environment, photographing while emitting a flash during a predetermined flash trigger time T1;

if it is determine that there is not a low brightness environment, photographing without emitting a flash; and

determining whether consecutive shooting is to be performed.

15. The method of claim 14, further comprising:

determining whether consecutive shooting is to be performed;

if it is determined that consecutive shooting is to be performed, determining whether there is a low brightness environment;

if it is determined that there is a low brightness environment, photographing while emitting a flash during a predetermined flash trigger time T1;

if it is determine that there is not a low brightness environment, photographing without emitting a flash; and

determining whether consecutive shooting is to be performed.

16. A camera comprising;

a photographing mode selection unit operated by a user to generate and output a consecutive shooting mode signal;

a release switch operated by the user to generate and output a photographing instruction signal;

a distance measurement unit to measure a distance L1 from the camera to an object;

a control unit to determine a flash trigger time T1 according to the measured distance L1 and output a flash trigger signal according to the flash trigger time T1 in response to the consecutive shooting mode signal;

an illumination unit having a predetermined power, a flash capacitor, and a flash and emitting a flash in response to the flash trigger signal; and

an image photographing unit to take a photograph.

17. The camera of claim 16, further comprising a brightness measurement unit to measure the brightness of an environment in which photographing is performed and output a brightness signal, wherein the control unit determines the flash trigger time T1 according to the distance T1 in response to the brightness signal and outputs a flash trigger signal according to the flash trigger time T1.

18. A camera comprising:

a release switch operated by a user to generate and output a photographing instruction signal;

a mode selection unit operated by the user to generate and output a consecutive shooting mode signal;

a distance measurement unit to measure a distance from the camera to an object;

a control unit to determine a flash trigger time according to the result of measuring the distance, compare the results of measuring the distances in a present frame and a preceding frame in response to the consecutive shooting mode signal, determine a flash trigger time corrected according to the result of comparison, and output a flash trigger signal according to the determined flash trigger time;

an illumination unit having a predetermined electric power, a flash capacitor, and a flash, to emit flash in response to the flash trigger signal; and

an image photographing unit to photograph the object.

19. The camera of claim 18, further comprising a brightness measurement unit to measure a brightness of an environment in which photographing is performed and output a brightness signal, wherein the control unit determines the flash trigger time according to the result of measuring the distance, compares the results of measuring the distances in the present frame and the preceding frame in response to the brightness signal, determines the flash trigger time corrected according to the result of comparison, and outputs a flash trigger signal according to the determined flash trigger time.