Method and apparatus for detecting optimum lens focus position

A lens focusing system comprising:

• a lens in a field of view of an image detector;
• a mechanism to move the lens;
• a compression engine, responsive to the image detector, to provide a compressed data file;
• and
• a digital processor to compare the size of each compressed data file and to provide a control signal to the motor to move the lens to a position that creates the largest compressed data file.

A method of focusing a lens comprising:

• (a) capturing a first image and digitally compressing and storing the data;
• (b) moving the lens to another position;
• (c) capturing a second image and digitally compressing and storing the data;
• and
• (d) comparing the size of the data file of the first image with the size of the data file of the second image and moving the lens in the direction of the position providing the larger file size.

An automatic focusing system for a camera comprising:

• a lens;
• a driver that drives said lens along an optical axis of said lens;
• a detector that receives an optical image through said lens and outputting signals indicative of said received optical image at an instant of time;
• a processor that processes said signals to provide a digital signal indicative of the optical image and to compress said digital signal to provide a compressed digital signal to provide a size signal indicative of the size of the compressed digital signal;
• and
• a controller that controls said driver to locate said lens at a position where said size signal becomes greatest.

A method of locating a lens in a unit under test comprising:

• placing a test target a fixed distance from the unit under test;
• moving the lens to one of a plurality of positions and capturing through the lens and digitally compressing a digital image of the test target to provide a compressed image file having a file size;
• moving the lens to another one of a plurality of positions and capturing through the lens and digitally compressing a digital image of the test target to provide a compressed image file having a file size until the file size is maximized;
• and
• fixing the lens within the unit under test at the position that provides the maximum file size.

A method of locating a sensor relative to a lens in a unit under test comprising:

• replicating a test target over regions of an object plane as it passes through the lens;
• capturing an image of the test target with the sensor and segmenting the image into regions corresponding to the regions of the object plane and compressing a digital image corresponding to each region and recording the relative size of the compressed image for each region;
• and
• adjusting the location of the sensor relative to the lens to set axial and tilt adjustments such that the relative size of the compressed image for each region is maximized.

A method comprising:

• (a) capturing a portion of a first image passing through a lens and digitally compressing and recording the size of the resulting data file;
• (b) moving the lens to another position;
• (c) capturing a portion of a second image passing through the lens and digitally compressing and recording the size of the resulting data file;
• and
• (d) comparing the size of the data file of the first image with the size of the data file of the second image to determine which lens position provides a larger file size.

A range finder comprising:

• a lens having a plurality of predetermined positions with corresponding ranges;
• a driver that drives said lens along an optical axis of said lens;
• a detector that receives an optical image through said lens and outputting signals indicative of said received optical image at an instant of time;
• a processor that processes said signals to provide a digital signal indicative of the optical image and to compress said digital signal to provide a compressed digital signal to provide a size signal indicative of the size of the compressed digital signal;
• and
• a controller that controls said driver to locate said lens at a position where said size signal becomes greatest, said position corresponding to a specific range.