Image sensor and image sensor system including the same

Patent metadata

Field	Value
Publication number	US-9485483-B2
Application number	US-201514607127-A
Country	US
Kind code	B2
Filing date	Jan 28, 2015
Priority date	Apr 9, 2014
Publication date	Nov 1, 2016
Grant date	Nov 1, 2016

Abstract

An image sensor includes a pixel array, a micro lens array and polarizing filters. The pixel array includes a plurality of pixels. The micro lens array is disposed on the pixel array and includes a plurality of micro lenses. The micro lens overlaps a pixel group of the pixel array. The polarizing filter is disposed on the micro lens and includes a plurality of polarizing filters having at least two different polarizing phases. Accordingly, the accuracy and the reliability of the local auto white balancing may be improved.

First claim

What is claimed is:

1. An image sensor system comprising:
an image sensor that generates signals representing an input image, the image sensor comprising:
a pixel array including a plurality of pixels,
a micro lens array disposed on the pixel array and including a plurality of micro lenses and a plurality of polarizing filters, each of the micro lenses being juxtaposed with a respective group of pixels of the pixel array, each of the polarizing filters being disposed on one of the micro lenses, and the polarizing filters having at least two different polarizing phases; and

a signal processor operatively connected to the image sensor and configured to generate a plurality of polarized sub images based on the input image and to conduct an auto white balancing process based on the polarized sub images,
wherein the signal processor comprises:
a polarized sub image generating part configured to generate the polarized sub images based on the input image,
a light source characteristic determining part configured to determine a characteristic value of a light source corresponding to a difference between the polarized sub images,
a depth determining part configured to determine a depth of the input image based on the polarized sub images, and
a local auto white balancing part configured to conduct local auto white balancing based on the characteristic value of the light source and the depth.

2. The image sensor system of claim 1 , wherein the micro lenses include first and second micro lenses disposed adjacent to each other, and
the plurality of polarizing filters comprise a first polarizing filter having a first polarizing phase and disposed on the first micro lens, and
a second polarizing filter having a second polarizing phase different from the first polarizing phase and disposed on the second micro lens.

3. The image sensor system of claim 2 , wherein the second micro lens is disposed adjacent to the first micro lens in a first direction,
the micro lenses include a third micro lens, and a fourth micro lens disposed adjacent to the third micro lens in the first direction, and
the plurality of polarizing filters comprise a third polarizing filter having a third polarizing phase and disposed on the third micro lens, the third micro lens being disposed adjacent to the first micro lens in a second direction, and
a fourth polarizing filter having a fourth polarizing phase different from the third polarizing phase and disposed on the fourth micro lens.

4. The image sensor system of claim 3 , wherein the first polarizing phase has a direction parallel to the second direction,
the second polarizing phase has a direction rotated by 90 degrees with respect to the second direction,
the third polarizing phase has a direction rotated by 45 degrees with respect to the second direction, and
the fourth polarizing phase has a direction rotated by 135 degrees with respect to the second direction.

5. The image sensor system of claim 3 , wherein the polarized sub image generating part is configured to generate as said polarized sub images a first polarized sub image using the first polarizing filter, a second polarized sub image using the second polarizing filter, a third polarized sub image using the third polarizing filter, and a fourth polarized sub image using the fourth polarizing filter.

6. The image sensor system of claim 5 , wherein the light source characteristic determining part is configured to subtract a minimum polarized sub image grayscale value having the smallest luminance among those of the first to fourth polarized sub images from a maximum polarized sub image grayscale value having the greatest luminance among the first to fourth polarized sub images.

7. The image sensor system of claim 1 , wherein the depth determining part is configured to determine the depth using a first disparity in a first direction in the pixel group juxtaposed with the micro lens and a second disparity in a second direction crossing the first direction in the pixel group juxtaposed with the micro lens.

8. The image sensor system of claim 1 , wherein the local auto white balancing part is configured to generate a white balancing compensating value using the characteristic values of the light source of the pixel groups in a local window which has a depth which is the same as a depth of a central pixel group corresponding to a center of the local window.

9. The image sensor system of claim 8 , wherein the white balancing compensating value is determined as a most frequent characteristic value of the light source among histograms of the characteristic values of the light source of the pixel groups in the local window which has the depth that is the same as the depth of the central pixel group.

10. The image sensor system of claim 8 , wherein the white balancing compensating value is determined as an average of the characteristic values of the light source of the pixel groups in the local window which has the depth that is the same as the depth of the central pixel group.

11. An image sensor system, comprising:
an array of pixels that convert incident light to electronic signals;
an array of micro lenses optically aligned with the pixels so as to direct light onto the pixels;
polarizers optically aligned with the micro lenses such that light directed onto the pixels in the sensor by the micro lenses is polarized by the polarizers, wherein the polarizers have transmission axes that are substantially parallel, and respective ones of the polarizers having transmission orientations different from one another; and
a signal processor operatively connected to the array of pixels and configured to conduct an auto white balancing process based on the signals produced by the pixels,
wherein the signal processor comprises:
a polarized sub image generating part configured to generate polarized sub images based on the signals produced by the pixels,
a light source characteristic determining part configured to determine a characteristic value of a light source corresponding to a difference between the polarized sub images,
a depth determining part configured to determine a depth of the input image based on the polarized sub images, and
a local auto white balancing part configured to conduct local auto white balancing based on the characteristic value of the light source and the depth.

12. The image sensor system of claim 11 , wherein the array of pixels comprises an array of respective groups of pixels, and each of the micro lenses is optically aligned with the pixels of a respective one of the groups thereof.

13. The image sensor system of claim 11 , wherein the micro lenses are disposed in a two-dimensional array in which each of the mirco lenses is disposed adjacent to others of the micro lenses in first and second directions, respectively,
the polarizers are disposed in a two-dimensional array such that the polarizers are optically aligned with the micro lenses, respectively, and each of the polarizers is disposed adjacent to others of the polarizers in the first and second directions, respectively, and
the transmission orientation of each of the polarizers is different from those of the polarizers disposed adjacent thereto in the first and second directions.

14. The image sensor system of claim 11 , wherein the micro lenses are arranged in units, the transmission orientations of the polarizers optically aligned with the micro lenses of each unit of micro lenses are the same as the transmission orientations of the polarizers optically aligned with the micro lenses of each of the other units of micro lenses, and
the signal processor is configured to ge

Assignees

• Samsung Electronics Co Ltd

Inventors

• Cho Sung-Kwang
• Kim Dae-Kwan
• Kim Tae-Chan
• Lee Hyung-Gu

Classifications

• G02B3/0056 Primary

  arranged along two different directions in a plane, e.g. honeycomb arrangement of lenses (G02B3/0043 takes precedence; miniaturised objectives for electronic devices employing wafer level optics G02B13/0085) · CPC title

• H04N23/88 Primary

  for colour balance, e.g. white-balance circuits or colour temperature control · CPC title

• G03B11/00

  Filters or other obturators specially adapted for photographic purposes · CPC title

• H04N9/735 Primary

  Electricity · mapped topic

• G02B5/30

  Polarising elements (light-modulating devices with active elements G02F1/00) · CPC title