Focus controlling method and system by evaluating a resolution index

A focus controlling method for scanning an original in a document wrapper on a document plate of an image capturing system, said focus controlling method comprising:

• setting a raised height of the original being scanned;
• adjusting a position of an image capturing device to scan a selected calibration paper of at least two calibration papers, a height of said selected calibration paper is about the same as the raised height of the original being scanned, said image capturing device having an input interface, said input interface having a menu of at least one document wrapper;
• adjusting a focus point of said image capturing device according to the height of the selected calibration paper;
• scanning said selected calibration paper to generate a resolution index;
• and
• repeating said adjusting step and said scanning step until said resolution index is about at a maximum value.

A focus controlling method for scanning an original in a document wrapper on a document plate of an image capturing system, said focus controlling method comprising:

• setting a raised height of the original being scanned;
• generating a target resolution index for compensating the raised height of the original being scanned;
• adjusting a focus point of the image capturing device according to the target resolution index;
• scanning a calibration paper to generate a resolution index;
• and
• repeating said adjusting step and said scanning step until said resolution index is about the same as said target resolution index.

A focus controlling system of an image capturing system for scanning an original in a document wrapper on a document plate of the image capturing system, the focus controlling system comprising:

• a calibration paper, having resolution patterns thereon, located on a surface of the document plate of the image capturing system;
• an image capturing device for scanning the calibration paper to generate a resolution index, the image capturing device having a focus point adjusting mechanism;
• an input interface for receiving a raised height of the original being scanned, said input interface having a menu of at least one document wrapper;
• a data converting device for providing a target resolution index corresponding to the raised height of the original being scanned;
• and
• processing and controlling means being responsive to the input interface and the image capturing device to control the focus point adjusting mechanism by adjusting the resolution index to be about the same as the target resolution index.