# US 5,350,909 A · Optical scanner for bar code scanning

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- Number: US 5,350,909 A
- Document ID: US5350909A
- Status: Granted
- Kind: A
- Application number: 07/960,656
- Filed: 1992-10-14
- Granted: 1994-09-27
- Earliest claimed: 1992-10-14
- Assignees: International Business Machines Corporation
- Inventors: Kenneth E. Powell; Deborah A. Mallory
- Web page: https://patentgrep.com/patent/US5350909A

## CPC

- G06K 7/10702: {Particularities of propagating elements, e.g. lenses, mirrors (G06K7/10831 takes precedence)}
- G06K 7/10811: {Focalisation}
- G06K 2207/1013: Multi-focal
- G06K: GRAPHICAL DATA READING (image or video recognition or understanding G06V); PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS

## Abstract

An apparatus for scanning bar code data recorded on a target includes a source emitting a beam of radiation, and optics for deflecting the beam of radiation along an axis normal to the beam. The apparatus further includes an electronic shutter element defining a plurality of adjacent regions, each region independently capable of assuming a substantially transparent state, and, digital logic, for causing the adjacent regions of the shutter element to assume substantially transparent states in a sequential, directional manner along the axis to affect directional transmission of less than all of the deflected beam onto the target. The apparatus further includes a detector for sensing the presence of radiation reflected from the target, and, optics for converting the radiation reflected from the target into a beam and for focussing the beam onto the detector.

## Claims

### Claim 1

An optical scanner for scanning bar code data comprising:
a) a source of a beam of radiation;
b) optical means for deflecting the beam of radiation along an axis normal to the beam;
c) an electronic shutter element, optically coupled with the optical means, said shutter element defining a plurality of adjacent regions, each region independently capable of assuming a substantially transparent state;
d) digital logic, coupled to said shutter element, for causing said adjacent regions of said electronic shutter to assume said substantially transparent state, in a sequential, directional manner along said axis to affect directional transmission of less than all of the deflected beam onto the target;
e) a detector for detecting the presence of radiation reflected from the target;
f) second optical means, optically coupled to the detector, for converting the radiation reflected from the target to a beam and for focusing the beam on the detector; and
g) a baffle optically isolating the detector from the source, said baffle further optically partitioning each of said plurality of regions of the electronic shutter element into an emission subregion and a detection subregion to affect simultaneous transmission through one of said regions the deflected beam toward the target and said reflected radiation toward said detector.

### Claim 2 (depends on 1)

The apparatus of claim 1 wherein
said detector converts detected radiation into electrical signals; and
said apparatus further in combination with decoding logic, responsive to said detector, for processing said electrical signals.

### Claim 3 (depends on 2)

The apparatus of claim 2 wherein said digital logic and decoding logic comprise a microprocessor.

### Claim 4

An apparatus for scanning bar code data records on a target, the apparatus comprising:
a) a source emitting a substantially circular beam of radiation;
b) beam expander optics, optically coupled to the source, for expanding the diameter of the circular beam;
c) a cylindrical lens, optically coupled with said beam expander optics, for deflecting the expanded beam along an axis normal to the expanded beam;
d) an electronic shutter element, optically coupled to the cylindrical lens, said shutter element defining a plurality of adjacent regions, each region independently capable of assuming a substantially transparent state;
e) a digital processor, coupled to said electronic shutter, for causing said adjacent regions of the electronic shutter to assume said substantially transparent state in a sequential, directional manner along said axis, to affect directional transmission of less than all of the deflected beam onto the target;
f) bending optics, optically coupled with said electronic shutter, for focusing less than all the deflected beam onto the target;
g) filter optics responsive to radiation reflected from the target;
h) a detector responsive to the presence of radiation reflected from the target and for converting radiation detected into electrical signals;
i) decode logic, responsive to said detector, for processing said converted electrical signals;
j) means, optically coupled with said filter optics, for converting the radiation received by the filter optics to a beam, and for focusing the beam onto the detector; and
k) a baffle optically isolating the detector from the source, said baffle further optically partitioning each of said plurality of regions of the electronic shutter element into an emission subregion and a detection subregion to affect simultaneous transmission through one of said regions the deflected beam toward the target and said reflected radiation toward said detector.

### Claim 5 (depends on 4)

The apparatus of claim 4 wherein said electronic shutter element comprises a liquid crystal display assembly having a plurality of adjacent rectangular regions which are independently capable of assuming either a substantially transparent state or a substantially opaque state.

### Claim 6 (depends on 4)

The apparatus of claim 4 wherein said digital processor and said decode logic comprise a microprocessor.

### Claim 7 (depends on 4)

The apparatus of claim 4 wherein said source emits laser radiation.

### Claim 8 (depends on 5)

The apparatus of claim 5 wherein said source emits infrared radiation.

### Claim 9 (depends on 4)

The apparatus of claim 4 wherein said beam expansion optics expand the diameter of said substantially circular beam of radiation by at least a factor of five.

### Claim 10 (depends on 1)

The apparatus of claim 1 wherein said electronic shutter element comprises a liquid crystal display assembly having a plurality of adjacent rectangular regions which are independently capable of assuming either a substantially transparent state or a substantially opaque state.

### Claim 11 (depends on 1)

The apparatus of claim 1 wherein said source emits laser radiation.

### Claim 12 (depends on 1)

The apparatus of claim 1 wherein said source emits infrared radiation.