Automatic electronic camera for label image capture
US5818528A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 30, 1996 |
| Grant date | Oct 6, 1998 |
| Priority date | — |
| Expiry date | May 30, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N23/72
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A hand held label reader is capable of illuminating a label, capturing a digital image of two-dimensional information indicia on the label, and decoding the digital image to provide decoded output data to a terminal. The target label is illuminated by a low variation illuminator that includes a circular LED array mounted behind a plano-concave dispersing lens. The automatic electronic camera, which includes a CCD camera and control circuitry, uses three images to adjust the intensity of the digital image and store a properly exposed image of the label in video RAM. The intensity of the digital image is adjusted by controlling the video system gain via adjusting the CCD array's integration time, the gain of a video amplifier, and the gain provided by an analog-to-digital converter. The gain provided by the analog-digital-converter is adjusted to compensate for the attenuation of light through the camera's lens assembly. For the first image, the digital image is obtained using a default setting for the gain. The image intensity is analyzed using a histogram process and new gain setting are determined. The second image is obtained using the gain settings derived from the first image. …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.