IMAGING AND DECODING DEVICE WITH QUANTUM DOT IMAGER

• US 20120224083A1
• Filed: 03/04/2011
• Published: 09/06/2012
• Est. Priority Date: 03/04/2011
• Status: Active Grant

• Current Assignee: Hand Held Products Incorporated (Honeywell International Inc.)
• Original Assignee: Hand Held Products Incorporated (Honeywell International Inc.)
• Inventors: Jovanovski, Brian, Van Volkinburg, Daniel, Chernyakov, Alexey
• Granted Patent: US 8,537,245 B2
• Time in Patent Office: Days
• US Class Current: 348/231.99
• CPC Class Codes: G06K 7/10722 Photodetector array or CCD scanning

Abstract

Devices, systems, and methods are disclosed for imaging with a decoding imager based on semiconducting nanocrystals that function as quantum dots, and decoding decodable features in the images. In an illustrative embodiment, a device includes an imaging subsystem, a data storage element, and a processor. The imaging subsystem includes an image sensor array and an imaging optics assembly operative for focusing an image onto the image sensor array. The image sensor array includes a plurality of pixels wherein a pixel includes a photosensitive portion comprising one or more nanocrystals, and a read-out portion capable of relaying incident light data representing light incident on the one or more nanocrystals. The data storage element is capable of storing frames of image data comprising data communicated through the read-out portion of at least some of the pixels during the imaging operation. The processor is operative for receiving one or more of the frames of image data from the data storage element and performing a decode operation for performing an attempted decode of a decodable feature represented in at least one of the frames of image data.

Claims

1. A device comprising:

an imaging subsystem comprising an image sensor array and an imaging optics assembly operative for focusing an image onto the image sensor array, the image sensor array comprising a plurality of pixels wherein a pixel comprises a photosensitive portion comprising one or more nanocrystals, and a read-out portion capable of relaying incident light data representing light incident on the one or more nanocrystals;

a data storage element capable of storing frames of image data comprising data communicated through the read-out portion of at least some of the pixels during the imaging operation; and

a processor operative for receiving one or more of the frames of image data from the data storage element and performing a decode operation for attempting to decode a decodable feature represented in at least one of the frames of image data.

2. The device of claim 1, wherein a plurality of the nanocrystals in the pixel are largely composed of a semiconducting material and have electrically conductive connections among at least some adjacent nanocrystals in the pixel.

3. The device of claim 1, wherein one or more of the nanocrystals has a band gap sensitive to visible light.

4. The device of claim 1, wherein each of a plurality of the pixels further comprises an in-pixel data storage portion capable of storing the data representing light incident on the one or more nanocrystals, and communicating the data representing light incident on the one or more nanocrystals to the data storage element.

5. The device of claim 4, wherein each of a plurality of the pixels is configured for initiating recording image data at the same time and finishing recording image data at the same time during the imaging operation.

6. The device of claim 4, further comprising a global electronic shutter control circuitry, the global electronic control circuitry configured to generate an exposure control timing pulse that is capable of causing simultaneous exposure of said pixels of said image sensor array during the imaging operation.

7. The device of claim 4, wherein the device is operative to selectively address and read-out image data from the in-pixel data storage portions comprised in a first plurality of the pixels independently of the in-pixel data storage portions comprised in a second plurality of the pixels.

8. The device of claim 1, wherein the device is operative to selectively address and read-out from the image sensor array image data from a first plurality of said pixels independently of a second plurality of said pixels.

9. The device of claim 1, wherein the processor is further operative for addressing a subset of the pixels, receiving a windowed frame of image data from the subset of the pixels, and performing a decode operation for attempting to decode a decodable feature represented in the windowed frame of image data.

10. The device of claim 1, wherein the read-out portion comprises at least a first pixel electrode and a second pixel electrode both connecting the photosensitive portion to a data read-out structure.

11. The device of claim 1, wherein the wherein the read-out portion comprises at least a first pixel electrode connecting the photosensitive portion to a data read-out structure, and the imaging subsystem further comprises one or more array electrodes positioned outside the pixels that complete a circuit with the first pixel electrode.

12. The device of claim 1, wherein a representative pixel comprises a plurality of pixel sublayers, wherein each of the pixel sublayers comprises an average nanocrystal size different from an average nanocrystal size of the other pixel sublayer or sublayers.

13. The device of claim 12, wherein the pixel sublayers are sized to promote both distribution of wavelength collection between the sublayers, and total quantum efficiency of the pixel.

14. The device of claim 12, wherein the read-out portion of the pixel further comprises a plurality of sublayer electrodes such that at least one of the sublayer electrodes is in contact with each of the pixel sublayers.

15. The device of claim 1, wherein a representative pixel comprises a first pixel sublayer at a surface of the pixel, a second pixel sublayer below the first pixel sublayer, and a third pixel sublayer below the second pixel sublayer, wherein the first pixel sublayer has a first average nanocrystal size, the second pixel sublayer has a second average nanocrystal size that is larger than the first average nanocrystal size, and the third pixel sublayer has a third average nanocrystal size that is larger than the second average nanocrystal size.

16. The device of claim 15, wherein the first average nanocrystal size has a peak absorption wavelength closer to the blue end than the red end of the visual spectrum;

the third average nanocrystal size has a peak absorption wavelength closer to the red end than the blue end of the visual spectrum; and

the second average nanocrystal size has a peak absorption wavelength between the peak absorption wavelengths of the first average nanocrystal size and third average nanocrystal size.

17. The device of claim 1, further comprising an imaging activation input element for activating an imaging operation with the imaging subsystem.

18. The device of claim 1, further comprising an illumination subsystem operative for projecting an illumination pattern during at least a portion of the imaging operation.

19. The device of claim 18, wherein the illumination subsystem comprises a single illumination source.

20. The device of claim 1, wherein the nanocrystals are colloidally suspended in a polymer medium.

21. The device of claim 1, wherein the nanocrystals are imprinted on the read-out portion.

22. A method comprising:

using an imaging subsystem comprising an image sensor array and an imaging optics assembly, focusing an image onto the image sensor array, the image sensor array comprising a plurality of pixels wherein a pixel comprises a photosensitive portion comprising a plurality of semiconducting nanocrystals with electrically conductive connections among at least some adjacent nanocrystals, and a read-out portion capable of relaying incident light data representing light incident on the one or more nanocrystals;

storing the incident light data in each of a plurality of the pixels on in-pixel data storage portions comprised in each of the plurality of the pixels;

communicating the incident light data from one or more of the pixels to a data storage element external to the image sensor array;

storing frames of image data, comprising incident light data communicated from the one or more pixels, on a data storage element; and

receiving one or more of the frames of image data at a processor from the data storage element; and

using the processor, performing a decode operation for attempting to decode a decodable feature represented in at least one of the frames of image data.

23. The method of claim 22, wherein each of a plurality of the pixels is configured for initiating recording image data at the same time and finishing recording image data at the same time during the imaging operation.

24. The method of claim 22, further comprising an electronic simultaneous shutter control circuitry, the electronic simultaneous control circuitry configured to generate an exposure control timing pulse that is capable of causing simultaneous exposure of said pixels of said image sensor array during the imaging operation.

25. The method of claim 22, wherein the device is operative to selectively address and read-out image data from the in-pixel data storage portions comprised in a first plurality of the pixels independently of the in-pixel data storage portions comprised in a second plurality of the pixels.

26. The method of claim 22, further comprising positioning the imaging subsystem on a mount, determining an imaging target area of the imaging subsystem, and programming the processor to selectively address and read-out image data from the in-pixel data storage portions comprised in a first plurality of the pixels that images the imaging target area.

27. The method of claim 22, further comprising taking one or more initial images, subjecting the one or more initial images to preprocessing to detect and locate any candidate decodable features in an imaging area, selecting one or more target sections of an imaging target area corresponding to the one or more initial images that are defined by the candidate decodable features, reading imaging data from the one or more target sections, and performing the decode operation for attempting to decode a decodable feature represented in the one or more target sections.