Code sensor with multi-faceted reflector for sensing plural image distances

• US 5,198,648 A
• Filed: 12/27/1990
• Issued: 03/30/1993
• Est. Priority Date: 12/27/1990
• Status: Expired due to Fees

• Current Assignee: Eastman Kodak Company
• Original Assignee: Eastman Kodak Company
• Inventors: Hibbard, Robert H.
• Primary Examiner(s): Shepperd, John W.
• Assistant Examiner(s): SIKORSKI, EDWARD
• Application Number:
  US07/634,638
• Time in Patent Office: 824 Days
• Field of Search: 235/439, 235/462, 235/467, 235/472, 235/454, 359/193, 359/196, 359/205, 359/208, 359/216, 359/439, 359/546, 359/850, 359/852
• US Class Current: 235/462.24
• CPC Class Codes: G06K 2207/1013 Multi-focal
• CPC Class Codes: G06K 7/10811 Focalisation
• CPC Class Codes: G06K 7/10831 Arrangement of optical elements, e.g. lenses, mirrors, prisms optical elements per se G02B

Abstract

A bar code scanner having a lens, a reflector, a sensor, and a detection unit. The lens is arranged to focus an image of a bar code to be scanned along an image path. The reflector is angled obliquely to the image path so as to reflect images at an angle to the image path. The reflector has reflector surface shaped so as to provide a plurality of reflected images of the scanned bar code, with one of the reflected image being an in-focus image and a remainder of the reflected images being out-of-focus images. The sensor is in the image path and simultaneously senses the plurality of reflected images and provides a sensor output signal corresponding to the sensed images. The detection unit is coupled to the sensor and decodes the sensor output signal and provides a bar code output signal that corresponds to the scanned bar code.

Claims

1. A bar code scanner comprising:

a lens arranged to focus an image of a bar code to be scanned along an image path;

a reflector in the image path and angled obliquely to the image path so as to reflect images at an angle to the image path, said reflector having a reflector surface shaped so as to provide a plurality of reflected images of the scanned bar code, with one of said reflected images being an in-focus image and a remainder of said reflected images being out-of-focus images;

a single linear array sensor in the image path onto which said images are reflected and which simultaneously senses the plurality of reflected images and provides a sensor output signal corresponding to the sensed images; and

a detection unit coupled to the sensor which decodes the sensor output signal and provides a bar code output signal that corresponds to the scanned bar code.

2. The bar code scanner of claim 1, wherein the reflector surface is shaped so as to comprise a plurality of facets.

3. The bar code scanner of claim 2, wherein the lens is positioned on the image path between the bar code to be scanned and the reflector.

4. The bar code scanner of claim 2, wherein the lens is positioned on the image path between the reflector and the single linear array sensor.

5. The bar code scanner of claim 1, wherein the single linear array sensor is a CCD sensor.

6. The bar code scanner of claim 1, wherein the detection unit includes means for filtering the in-focus image from the out-of-focus images contained in the sensor output signal and producing the code output signal from the in-focus image.

7. The bar code scanner of claim 1, wherein the reflector surface is smoothly curved so as to provide the in-focus and out-of-focus reflected images to said single linear array sensor.

8. The bar code scanner of claim 1, wherein the reflector surface is shaped so as to provide the in-focus and the out-of-focus reflected images superimposed on the single linear array sensor.

9. A method of scanning a code comprising:

simultaneously focusing a plurality of images of the code onto a single linear array sensor, said plurality of images containing an in-focus image of the code and a plurality of out-of-focus images;

producing a single linear array sensor output signal corresponding to the plurality of images focused onto said sensor;

determining the in-focus image from the sensor output signal; and

decoding the in-focus image to extract information.

10. The method of claim 9, wherein said step of simultaneously focusing includes the step of simultaneously reflecting separate images of the code from a reflector onto said single linear array sensor.

11. The method of claim 10, wherein the reflector is a faceted reflector and the step of simultaneously reflecting includes the step of reflecting a plurality of images from a single image with the faceted reflector.

12. The method of claim 10, wherein the separate images are superimposed by the reflector and the single linear array sensor receives said superimposed images.