Digitally controlled system for scanning and reading bar codes
First Claim
1. A portable scanner unit for scanning an optical beam across a symbol when pointed toward the symbol for reading data represented by the symbol in response to light returned to said unit which comprises optical assembly means including a light source for producing the optical beam and means for scanning the beam across the symbol, means including a photodetector illuminated by said return light and circuitry for translating the returned light into electrical signals with variable sensitivity of translation, means for varying the sensitivity of said translating means which corresponds to the relationship of the amplitude of said electrical signal to the intensity of said return light illuminating said photodetector, manually actuable means for providing an output upon actuation which is manually variable in magnitude and for operating said light source when said unit is pointed towards said symbol, and control means including a computer for generating a plurality of digital control signals corresponding respectively to a predetermined optical intensity of said beam, the intensity of said returned light, and the magnitude of variable output of said manually actuable means and applying said digital control signals to said optical assembly means and said means for varying the sensitivity of translation of said translating means for controlling with said digital control signals the intensity of the light produced by said lights source, the sensitivity of said translating means to said returned light and the distance over which said scanning means scans the beam across said symbol.
5 Assignments
0 Petitions
Accused Products
Abstract
A unitary hand-held bar code scanner and reader produces an elliptical beam, oriented with its major axis along the direction of the bars, utilizing optics employing far field diffraction effects to shape the beam and maintain its elliptical aspect (length to width ratio) constant over a distance in front of the scanner were bar codes may be located. The optics eliminates parallax even though the photodetector and light source (preferably a laser diode) are located offset from each other on a board on which the optics are mounted. A housing assembly has channels which mount the board therein without shock absorbing devices. A digital microcomputer controller and peripheral devices regulate the optical power output from the laser diode and prevents catastrophic failure, if the electrical current through the laser diode exceeds safe limits. Digital control of the gain of the electronic circuits which provide the signals from which bar code information can be decoded and for the operation and control of a motor for oscillating a deflector which scans the beam across the code are also provided utilizing the microcomputer. The microcomputer also controls interface circuits to provide compatibility with auxiliary equipment and host computers which generate commands and requires data inputs of various polarity and format.
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Citations
30 Claims
- 1. A portable scanner unit for scanning an optical beam across a symbol when pointed toward the symbol for reading data represented by the symbol in response to light returned to said unit which comprises optical assembly means including a light source for producing the optical beam and means for scanning the beam across the symbol, means including a photodetector illuminated by said return light and circuitry for translating the returned light into electrical signals with variable sensitivity of translation, means for varying the sensitivity of said translating means which corresponds to the relationship of the amplitude of said electrical signal to the intensity of said return light illuminating said photodetector, manually actuable means for providing an output upon actuation which is manually variable in magnitude and for operating said light source when said unit is pointed towards said symbol, and control means including a computer for generating a plurality of digital control signals corresponding respectively to a predetermined optical intensity of said beam, the intensity of said returned light, and the magnitude of variable output of said manually actuable means and applying said digital control signals to said optical assembly means and said means for varying the sensitivity of translation of said translating means for controlling with said digital control signals the intensity of the light produced by said lights source, the sensitivity of said translating means to said returned light and the distance over which said scanning means scans the beam across said symbol.
- 16. A portable scanner unit for scanning an optical beam across a symbol when pointed toward the symbol for reading data represented by the symbol in response to light returned to said unit which comprises optical assembly means including a light source for producing the optical beam and means for scanning the beam across the symbol, means including a photodetector illuminated by said returned light and circuitry for translating the returned light into electrical signals with variable sensitivity of translation, means for varying the sensitivity of translation of said translating means corresponding to the relationship of the amplitude of said electrical signals to the intensity of said returned light illuminating said photodetector, means for operating said light source when said unit is pointed towards said symbol, control means including a computer for generating a plurality of digital control signals corresponding, respectively, to a predetermined optical intensity of said beam and the intensity of said returned light and applying said digital control signals to said optical assembly means and said means for varying the sensitivity of translation of said translating means for controlling with said digital control signals the intensity of the light produced by said light source, and the sensitivity of said translating means to said returned light.
Specification