Axial chromatic aberration auto-focusing system and method
AssigneeSymbol Technologies, Inc.
InventorsVladimir Gurevich, Mark Krichever, Bradley S. Carlson, Chinh Tan
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Abstract
A system and method utilizing the principles of axial chromatic aberration for auto-focusing an image onto an image sensor are provided. The system and method are particularly suitable for incorporation within an optical code reader. A signal processor analyzes data signals representative of the intensity or magnitude of wavelength components of an impinged image onto the image sensor for determining a value indicative of the focus quality of the impinged image. An actuator controls movement of a lens in accordance with the determination until obtainment of a desired focus quality. A decoder decodes the image having the desired focus quality.
Claims27
An optical code reading system for imaging and decoding an optical code, said optical code reading system comprising:
- an optical code reader comprising an image sensor for imaging said optical code and generating at least one data signal representative of a parameter of at least one wavelength component of said optical code impinging onto said image sensor, and at least one lens positioned for movement along an optical axis of said optical code reader, wherein each of said at least one data signal represents a particular color;
- a signal processor comprising means for performing an analysis utilizing principles of axial chromatic aberration and a value indicative of the parameter of a single wavelength component of the at least one wavelength component associated with a single data signal of the at least one data signal representing one of the colors, and means for determining an amount of movement of said at least one lens for adjusting a focus quality of an image corresponding to said optical code and impinged onto said image sensor, such that said amount of movement is determined based on the analysis;
- an actuator operatively coupled to said at least one lens for moving said at least one lens along said optical axis of said optical code reader by at least the determined amount for adjusting the focus quality of said image;
- and
- a decoder for decoding data encoded by said image.
A method for imaging and decoding an optical code, said method comprising the steps of:
- imaging said optical code by an image sensor and generating at least one data signal representative of a parameter of at least one wavelength component of said optical code impinging onto said image sensor, wherein each of said at least one data signal represents a particular color;
- performing an analysis utilizing principles of axial chromatic aberration and a value indicative of the parameter of a single wavelength component of the at least one wavelength component associated with a single data signal of the at least one data signal representing one of the colors;
- determining an amount of movement of at least one lens based on said analysis for adjusting a focus quality of an image corresponding to said optical code and impinged onto said image sensor, such that said amount of movement is determined based on the analysis;
- moving said at least one lens by at least the determined amount for adjusting the focus quality of said image;
- and
- decoding data encoded by said image.
A system for adjusting a focus quality of an image impinging onto an image sensor and for decoding data encoded by said image, said system comprising:
- means for generating at least one data signal representative of a parameter of at least one wavelength component of said image, wherein each of said at least one data signal represents a particular color;
- means for performing an analysis utilizing principles of axial chromatic aberration and a value indicative of the parameter of a single wavelength component of the at least one wavelength component associated with a single data signal of the at least one data signal representing one of the colors;
- an actuator for moving at least one lens in accordance with the analysis for adjusting the focus quality of said image, such that an amount of movement of said at least one lens is determined based on the analysis;
- and
- a decoder for decoding data encoded by said image.
A method for adjusting a focus quality of an image impinging onto an image sensor and for decoding data encoded by said image, said method comprising the steps of:
- generating at least one data signal representative of a parameter of at least one wavelength component of said image, wherein each of said at least one data signal represents a particular color;
- performing an analysis utilizing principles of axial chromatic aberration and a value indicative of the parameter of a single wavelength component of the at least one wavelength component associated with a single data signal of the at least one data signal representing one of the colors;
- moving at least one lens in accordance with the analysis for adjusting the focus quality of said image, such that an amount of movement of said at least one lens is determined based on the analysis;
- and
- decoding data encoded by said image.
A method for determining a focus discriminator for a focusing system, said method comprising the steps of:
- generating a data signal representative of a parameter of a single wavelength component of an image impinged onto an image sensor of said focusing system;
- performing an analysis by determining a difference between a value indicative of the parameter of the wavelength component and a value stored within a memory, wherein said difference is a focus discriminator indicating whether said image requires focusing by said focusing system;
- and
- decoding data encoded by said image.
Dependencies are inferred from the claim text.