Mobile terminal and auto-focusing method using a lens position error compensation
First Claim
1. An auto-focusing method using a lens position error compensation for a mobile terminal having a camera module, comprising:
- detecting a target object during a photograph mode;
determining a lens position at which a focus value gradient related to the detected target object changes sign while moving a lens of the camera module in units of one step size; and
performing a lens position compensation by moving the lens to the determined lens position.
1 Assignment
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Accused Products
Abstract
A mobile terminal and auto-focusing method for the same are disclosed. The auto-focusing method uses a lens position error compensation and includes: detecting a target object during a photograph mode; determining a lens position at which a focus value gradient related to the detected target object changes sign while moving a lens of the camera module in units of one step size; and performing lens position compensation by moving the lens to the found lens position. As a result, the lens position errors caused by a conventional a voice coil motor are compensated, thereby providing rapid and fine auto-focusing.
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Citations
24 Claims
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1. An auto-focusing method using a lens position error compensation for a mobile terminal having a camera module, comprising:
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detecting a target object during a photograph mode; determining a lens position at which a focus value gradient related to the detected target object changes sign while moving a lens of the camera module in units of one step size; and performing a lens position compensation by moving the lens to the determined lens position. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. An auto-focusing method using a lens position error compensation for a mobile terminal having a camera module, comprising:
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setting a search start point to a lens position at which focus values start to change; detecting a target object during a photograph mode; determining a first lens position at which a focus value gradient related to the detected target object changes sign while moving forwards from the search start point a lens of the camera module in units of a first step size, and moving the lens to the determined first lens position; determining a second lens position at which the focus value gradient changes sign while moving backwards from the first lens position the lens in units of a second step size less than the first step size, and moving the lens to the determined second lens position; and determining an optimum focus lens position corresponding to a maximum focus value while moving forwards from the second lens position the lens in units of a third step size less than the second step size, and moving the lens to the determined optimum focus lens position. - View Dependent Claims (11, 12, 13, 14, 15, 16)
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17. A mobile terminal capable of performing auto-focusing through lens position error compensation, comprising:
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a camera module including a lens for detecting a target object during a photograph mode, a voice-coil motor for moving the lens, and an image signal processor for calculating a focus value and a focus value gradient related to the detected target object; and a control unit for setting a search start point to a lens position at which focus values start to change, determining a lens position at which the gradient of the focus value curve changes sign while moving from the search start point the lens in units of one step size, and performing lens position compensation by moving the lens to the found lens position. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24)
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Specification