System for adjusting focus of a liquid lens in a machine vision system
First Claim
Patent Images
1. A system for performing a vision process using a camera, the system comprising:
- a liquid lens having an imaging lens field of view where the focus of the liquid lens is adjustable;
an imaging sensor for imaging the field of view;
at least one calibration target positioned at a predetermined location within the field of view;
a processor receiving imaging data from the imaging sensor, the processor being programmed to;
capture an image at a number of different focus positions of the liquid lens;
calculate a value that compares that part of the image where the calibration target is located to a known, focused image acquired of the calibration target stored in memory; and
use the comparison to determine temperature and aging effects of the liquid lens.
1 Assignment
0 Petitions
Accused Products
Abstract
A method and apparatus for recalibrating a liquid lens. In one embodiment, a lens holder is provided to adjust the focal length of the lens as a function of temperature. In another embodiment, a recalibration circuit including a second lens of similar characteristics to the imaging lens is used to determine an appropriate focus. In other embodiments, an open loop calibration process is used.
-
Citations
20 Claims
-
1. A system for performing a vision process using a camera, the system comprising:
-
a liquid lens having an imaging lens field of view where the focus of the liquid lens is adjustable; an imaging sensor for imaging the field of view; at least one calibration target positioned at a predetermined location within the field of view; a processor receiving imaging data from the imaging sensor, the processor being programmed to; capture an image at a number of different focus positions of the liquid lens; calculate a value that compares that part of the image where the calibration target is located to a known, focused image acquired of the calibration target stored in memory; and use the comparison to determine temperature and aging effects of the liquid lens. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A system for performing a vision process using a camera, the system comprising:
-
a liquid lens having an imaging lens field of view where the focus of the liquid lens is adjustable; an imaging sensor for imaging the field of view; a calibration target; a first aiming illuminator; a second aiming illuminator; a processor receiving imaging data from the imaging sensor, the processor being programmed to; calculate a distance between the aiming illuminator and the second aiming illuminator; focus the liquid lens to obtain a sharp image of the calibration target; calculate a ratio of the distance to a size of the calibration target; and use the ratio to determine a distance to the calibration target, wherein the calculated distance is usable to focus the liquid lens. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
-
Specification