Self-calibrating and/or self-testing camera module
Improved digital camera module incorporating circuitry for self-test and calibration. The digital camera module incorporates an image sensor, an image processor using volatile working memory and non-volatile memory containing correction data to produce corrected images during normal device operation. During test and calibration, a calibration processor takes image sensor data and produces correction data which is stored in the non-volatile memory.
1 . A digital camera module comprising:
an image sensor,
an image processor receiving data from the image sensor and producing corrected image data,
a calibration processor receiving data from the image sensor,
volatile working memory for use by the image processor and calibration processor,
non-volatile memory for holding correction data generated by the correction processor for use by the image processor, and
a control processor with control inputs controlling the operation of the image sensor, calibration processor, and image processor.
2 . The digital camera module of claim 1 where the image sensor, calibration processor, control processor, and image processor are manufactured on a single integrated circuit.
3 . The digital camera module of claim 1 where the image sensor, calibration processor, control processor, image processor, and volatile working memory are manufactured on a single integrated circuit.
4 . The digital camera module of claim 1 where the image sensor, calibration processor, control processor, image processor, volatile working memory, and non-volatile memory are manufactured on a single integrated circuit.
5 . The digital camera module of claim 1 where the calibration processor and the image processor are implemented using a common digital signal processor.
6 . The digital camera module of claim 1 where the non-volatile memory is a write-once memory.
7 . The digital camera module of claim 1 where the non-volatile memory is a rewriteable memory.
8 . The digital camera module of claim 1 where the control inputs select from a plurality of operating modes including at least one mode where the calibration processor analyzes the output of the image sensor responding to a preselected test image and writes correction data to the non-volatile memory.
9 . The digital camera module of claim 8 where the control processor includes an output signal responsive to the calibration processor to indicate to external circuitry whether the module passed or failed predetermined criteria in analyzing the output of the image sensor responding to the preselected test image.
10 . The digital camera module of claim 8 where the calibration processor is responsive to a plurality of test images.
11 . The digital camera module of claim 10 where the calibration processor responding to a test image writes correction data to the nonvolatile memory for correcting fixed pattern noise.
12 . The digital camera module of claim 10 where the calibration processor responding to a test image writes correction data to the nonvolatile memory for correcting row and/or column noise.
13 . The digital camera module of claim 10 where the calibration processor responding to a test image writes correction data to the nonvolatile memory for correcting blemishes.
14 . The digital camera module of claim 10 where the calibration processor responding to a test image writes correction data to the nonvolatile memory for correcting vignetting.
15 . The digital camera module of claim 10 where the calibration processor responding to a test image writes correction data to the nonvolatile memory for correcting color balance.