Methods and apparatus for obtaining imaging information in bar code scanners
AssigneeNCR Corporation
InventorYeming Gu
Life of this patent
Estimating the term…
Abstract
Techniques for using a scan pattern to estimate imaging information for an object reflecting the scan pattern are described. As an object is brought within range of a scan window, a scan beam tracing out a scan pattern comprising a plurality of scan lines causes reflection of the scan beam back into the scan window to produce a scanner signal based on reflections of the scan beam. The time at which the scanner signal indicates the presence of an object is noted and this timing information is mapped to position information identifying the position of the scan beam. The timing and position information is used to estimate imaging information about the object, including position, size, shape and motion information.
Claims17
A bar code scanner comprising:
- a scan window;
- a laser source for producing a scan beam emerging from the scan window and striking an object within range of the scan window to produce reflections from the scan beam off of the object, a portion of the reflections comprising light reentering the scan window;
- collection optics for collecting the light reentering the scan window;
- a photodetector for producing a photosignal based on the light collected by the collection optics;
- a time space module for processing the signal to estimate imaging information relating to the object producing the reflections, the time space module being operative to note a time at which the signal indicates that an event of interest has occurred, the time space module being further operative to note a position of the scan beam at the time an event of interest has occurred and to employ the information provided by the timing of events and the position of the scan beam at the occurrence of events to estimate imaging information relating to the object.
A bar code scanner comprising:
- a first scan window;
- a first laser source for producing a first scan beam emerging from the first scan window and striking an object within range of the first scan window to produce reflections from the first scan beam off of the object, a portion of the reflections comprising light reentering the first scan window;
- a first set of collection optics for collecting the light reentering the scan window;
- a first photodetector for producing a first photosignal based on the light collected by the first set of collection optics;
- a second scan window;
- a second laser source for producing a second scan beam emerging from the second scan window and striking an object within range of the second scan window to produce reflections from the second scan beam off of the object, a portion of the reflections comprising light reentering the second scan window;
- a first set of collection optics for collecting the light reentering the scan window;
- a first photodetector for producing a first photosignal based on the light collected by the first set of collection optics;
- a time space module for processing the first and second photosignals to estimate imaging information relating to the object producing the reflections, the time space module being operative to note a time at which each photosignal indicates that an event of interest has occurred, the time space module being further operative to note a position of the first scan beam at the time the first photosignal indicates that an event of interest has occurred and to note a position of the second scan beam at the time the second photosignal indicates that an event of interest has occurred and to employ the information provided by the timing of events and the position of the first and second scan beams at the occurrence of events to estimate imaging information relating to the object.
A method of image estimation for a bar code scanner, comprising the steps of:
- emitting a scan beam from a scanner window to strike an object within range of the scan window in order to cause reflections from the object into the scan window;
- collecting the reflections from the object into the scan window;
- producing a scanner signal based on the reflections, the scanner signal indicating when the scan beam is or is not striking the object;
- noting timing information indicating the times when the scanner signal indicates that the scan beam is striking the object;
- using the timing information to determine the position of the scan beam when the scanner signal indicates that the scan beam is striking the object;
- and
- estimating imaging information relating to the object based on the position of the scan beam at the times when the scan beam is striking the object.
Dependencies are inferred from the claim text.