Apparatus and method for controlling light intensity of camera

• US 20110317988A1
• Filed: 06/27/2011
• Published: 12/29/2011
• Est. Priority Date: 06/28/2010
• Status: Active Grant

• Current Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Original Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Inventors: Lee, Choon Bok
• Granted Patent: US 8,548,316 B2
• Time in Patent Office: Days
• US Class Current: 396/61
• CPC Class Codes: G03B 13/34 Power focusing
• 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
• CPC Class Codes: H04N 23/67 Focus control based on electronic image sensor signals
• CPC Class Codes: H04N 23/74 by influencing the scene brightness using illuminating means

Abstract

Provided is an apparatus and method of controlling light intensity of a camera. The method of controlling light intensity of a camera includes generating a code value for correcting a positional error of the camera to store the positional error in a memory, and then, reflecting the code value for correcting the positional error to generate a code value upon auto-focusing. Next, after measuring a distance to a subject through displacement of a camera lens according to the auto-focusing, light intensity of a flash is adjusted according to the distance to the subject.

Claims

1. A method of controlling light intensity of a camera, which comprises:

generating a code value for correcting a positional error of the camera to store the code value in a memory;

performing an auto-focusing function through a code value, to which the code value for correcting the positional error is added, to measure a distance to a subject; and

adjusting light intensity of a flash according to the distance to the subject.

2. The method according to claim 1, wherein generating a code value for correcting a positional error of the camera to store the code value in a memory comprises:

performing the auto-focusing function in a state in which the camera is in a horizontal posture to measure a current value applied to drive a voice coil actuator (VCA) of the camera;

performing the auto-focusing function in a state in which the camera is in a vertical posture to measure a current value applied to drive the VCA of the camera; and

obtaining a current value of the positional error of the camera, and then, converting the current value of the positional error into a code value to store the code value in the memory.

3. The method according to claim 2, wherein, in obtaining a current value of the positional error of the camera, and then, converting the current value of the positional error into a code value to store the code value in the memory, the current value of the positional error of the camera is a difference between a current value measured in the horizontal posture and a current value measured in the vertical posture.

4. The method according to claim 1, wherein performing an auto-focusing function through a code value, to which the code value for correcting the positional error is added, to measure a distance to a subject comprises:

adding the code value for correcting the positional error and generating a code value for the auto-focusing;

generating a current corresponding to the generated code value and driving an actuator to perform the auto-focusing; and

checking displacement of a camera lens according to the auto-focusing, and then, extracting data of the distance to the subject corresponding to the displacement of the camera lens.

5. An apparatus for controlling light intensity of a camera, which comprises:

an actuator including at least one lens and moving the lens according to a drive signal applied from the exterior to perform an auto-focusing;

a driver configured to generate a current corresponding to a code value transmitted from the exterior and applying the current as the drive signal to the actuator;

a memory configured to store a code value for correcting a positional error of the camera and data of a distance to a subject according to displacement of the lens;

a flash configured to emitting light while differentiating the light intensity according to the distance to the subject; and

a controller configured to reflect the code value for correcting the positional error of the camera to generate a code value for the auto-focusing and then transmit the generated code value to the driver, check the displacement of the lens according to the auto-focusing to extract the distance to the subject according to the displacement from the memory, and adjust the light intensity of the light emitted from the flash according to the extracted distance to the subject.