High dynamic range image sensor system and method thereof

• US 9,380,228 B2
• Filed: 03/13/2014
• Issued: 06/28/2016
• Est. Priority Date: 03/13/2013
• Status: Active Grant

• Current Assignee: HL Klemove Corporation
• Original Assignee: Gentex Corporation
• Inventors: McMillan, Daniel G., Bush, Gregory S.
• Primary Examiner(s): Haskins, Twyler
• Assistant Examiner(s): Chiu, Wesley J
• Application Number:
  US14/209,235
• Publication Number:
  US 20140267856A1
• Time in Patent Office: 838 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G06F 2212/00 Indexing scheme relating to accessing, addressing or allocation within memory systems or architectures
• CPC Class Codes: H04N 25/533 by using differing integration times for different sensor regions
• CPC Class Codes: H04N 25/771 comprising storage means other than floating diffusion

Abstract

A high dynamic range imager system is provided that includes an imager having a pixel array, and memory in communication with the pixel array, the memory comprising a plurality of memory cells, wherein the number of memory cells is approximately the number of whole row-times of exposures between the first conditional reset and row readout.

Claims

1. A high dynamic range imager system comprising:

an imager comprising;

a pixel array disposed on a die comprising a plurality of pixel rows;

a memory disposed on the die and in communication with the pixel array, the memory comprising a plurality of memory cells configured to store data representative of a selected conditional reset;

a memory manager in communication with the memory and configured to allocate a portion of the memory cells to each pixel row of the plurality of pixel rows at a time of a conditional reset of each pixel row,

wherein the number of memory cells is based upon an exposure time between a first conditional reset and a row readout of each pixel row.

2. A high dynamic range imager system as in claim 1, wherein the memory manager is configured to maintain a list of defective memory locations and skip the defective memory locations when allocating the portion of the memory cells.

3. A high dynamic range imager system as in claim 2, wherein the memory manager is configured to skip the defective memory locations by allocating a plurality of additional memory cells of the memory to at least one pixel row of the plurality of pixel rows between the first conditional reset and the row readout of the at least one pixel row.

4. A high dynamic range imager system as in claim 3, wherein the additional memory cells correspond to a plurality of potentially defective memory cells.

5. A high dynamic range imager system as in claim 1, wherein the number of memory cells is a number of pixels in the plurality of pixel rows from a first conditional reset to a row readout of each pixel row.

6. An imager die for storing integration period selection data for a high dynamic range image sensor comprising:

a pixel array comprising a plurality of pixel rows;

an imager memory in communication with the pixel array, the imager memory comprising a plurality of memory cells;

a memory manager in communication with the pixel array and the imager memory, the memory manager configured to control an allocation of the memory cells for the data from the pixel array; and

wherein the number of memory cells allocated by the memory manager is the number of pixels in the plurality of pixel rows from a first conditional reset of a first row of the plurality of pixel rows to a row readout of a second row of the plurality of pixel rows and the number of the memory cells is based upon an exposure time between the first conditional reset and the row readout.

7. The imager die of claim 6, wherein the number of memory cells is further based on a plurality of additional conditional resets between the first conditional reset and the row readout.

8. The imager die of claim 6, wherein the memory manager is configured to allocate a row of the plurality of memory cells to each row of the plurality of pixel rows at a time of the first conditional reset of each row of the plurality of pixels rows.

9. The imager die of claim 6, wherein the memory manager is configured to reuse a memory row of the plurality of memory cells to allocate the memory row from the second row of the pixel rows to a third row of the plurality of pixel rows in response to the row readout of the second row.

10. The imager die of claim 9, wherein the memory row is reused a plurality of times to allocate the data from a portion of the plurality of pixel rows during the collection of a single image frame.

11. A high dynamic range imager comprising:

a pixel array comprising a plurality of pixel rows;

a memory disposed on an imager die in communication with the pixel array and configured for storing data representative of an integration period index in a plurality of memory rows comprising memory cells;

a memory manager in communication with the pixel array and the memory, the memory manager configured to control a dynamic allocation of the memory cells for the data from each of the plurality of pixel rows in the plurality of memory rows; and

wherein the number of pixel rows is greater than the number of the plurality of memory rows and the number of the memory cells is based upon an exposure time between a first conditional reset and a row readout of at least one pixel row.

12. The high dynamic range imager as in claim 11, wherein the memory manager is configured to dynamically allocate the memory cells to store the data from the plurality of pixel rows in response to a first conditional reset of each pixel row of the plurality of pixel rows.

13. The high dynamic range imager as in claim 12, wherein dynamically allocating the data from the plurality of pixel rows further comprises unassociating a pixel row of the plurality of pixel rows from a memory row of the plurality of memory rows in response to a row readout of the pixel row to provide an available memory row.

14. The high dynamic range imager as in claim 13, wherein dynamically allocating the data from the plurality of rows further comprises reusing the available memory row such that the plurality of memory rows is configured to store the data from each of the plurality of pixel rows.

15. The high dynamic range imager as in claim 13, wherein the number of memory rows further comprises at least one additional memory row corresponding to the memory row allocated by the memory manager for the row readout of the pixel row to provide the available memory row.

16. The high dynamic range imager as in claim 11, wherein the number of memory rows further comprises at least one additional memory row allocated by the memory manager for at least one defective memory cell identified by the memory manager in a defective memory row of the plurality of memory rows.

17. The high dynamic range imager as in claim 11, wherein the number of the memory cells is based upon the plurality of pixel rows from a first conditional reset of a first row of the plurality of pixel rows to a row readout of a second row of the plurality of pixel rows.