HDR image sensor with LFM and reduced motion blur

Patent metadata

Field	Value
Publication number	US-11044417-B2
Application number	US-202016822331-A
Country	US
Kind code	B2
Filing date	Mar 18, 2020
Priority date	Sep 19, 2018
Publication date	Jun 22, 2021
Grant date	Jun 22, 2021

Abstract

An HDR image sensor supporting LED Flicker Mitigation to reduce Motion Blur and a method of operating same are provided. A timing controller circuit generates at least one control signal that controls an operation of the image sensor. A split-photodiode (PD) pixel includes at least two or more photodiodes that may be independently exposed to one or more bursts of light from a light source. A first photodiode of the two or more photodiodes has a first exposure period that is longer in duration than a second exposure period of a second photodiode of the two or more photodiodes. The second photodiode performs a fragmented exposure operation in which a plurality of exposure periods of the second photodiode are shorter in duration than the first exposure period of the first photodiode, and include both continuous and fragmented exposure periods to capture the one or more bursts of light.

First claim

What is claimed is:

1. An image sensor comprising:
at least one pixel, in which the at least one pixel comprises a split photodiode pixel including a first photodiode and a second photodiode,
wherein the first photodiode is configured to be exposed during a first exposure period in response to a first control signal received from a controller,
wherein a second photodiode is configured to be exposed, in response to a second control signal received from the controller, during a plurality of exposure periods including a fragmented medium exposure period, a continuous medium exposure period, a fragmented short exposure period, and a continuous short exposure period, and
wherein the first exposure period of the first photodiode is a continuous long exposure that is longer in duration than any of the plurality of exposure periods of the second photodiode.

2. The image sensor of claim 1 , wherein a fragmented medium exposure operation and a fragmented short exposure operation performed by the second photodiode occurs sequentially.

3. The image sensor of claim 2 , wherein the fragmented medium exposure operation and the fragmented short exposure operation occur during the first exposure period of the first photodiode.

4. The image sensor of claim 3 , wherein the fragmented medium exposure operation and the fragmented short exposure operation occur during a frame.

5. The image sensor of claim 4 , wherein a plurality of fragmented medium exposure operations performed by the second photodiode occurs during the frame.

6. The image sensor of claim 5 , wherein a plurality of fragmented short exposure operations performed by the second photodiode occurs during the frame.

7. The image sensor of claim 6 , wherein the plurality of fragmented medium exposure operations and the plurality of fragmented short exposure operations occur during the first period of the first photodiode.

8. The image sensor of claim 1 , wherein the fragmented medium exposure period is longer than the fragmented short exposure period.

9. The image sensor of claim 1 , wherein the fragmented medium exposure period is one of evenly divided N parts of the continuous medium exposure period,
wherein the fragmented short exposure period is one of evenly divided M parts of the continuous short exposure period,
wherein each of N and M is a natural number.

10. The image sensor of claim 1 , a continuous medium exposure operation and a continuous short exposure operation performed by the second photodiode occurs sequentially after the first exposure period of the first photodiode.

11. An image sensor comprising:
at least one pixel, in which the at least one pixel comprises a split photodiode pixel including a first photodiode and a second photodiode,
wherein the first photodiode is configured to be exposed during a first exposure period in response to a first control signal received from a controller,
wherein a second photodiode is configured to be exposed, in response to a second control signal received from the controller, during a plurality of exposure periods including a fragmented medium exposure period, a continuous medium exposure period, a fragmented short exposure period, and a continuous short exposure period, and
wherein the second photodiode is blanked during a blank period.

12. The image sensor of claim 11 , wherein the blank period is placed between a first fragmented medium exposure operation and a second fragmented medium exposure operation which is performed by the second photodiode.

13. The image sensor of claim 12 , wherein the first and second fragmented medium exposure operations occur during a frame.

14. The image sensor of claim 13 , wherein the first fragmented medium exposure operation and a first fragmented short exposure operation performed by the second photodiode occur during the first exposure period of the first photodiode.

15. The image sensor of claim 14 , wherein the first and second fragmented short exposure operation performed by the second photodiode occurs during the frame.

16. The image sensor of claim 15 , wherein the blank period is placed between the first fragmented short exposure operation and the second fragmented short exposure operation.

17. The image sensor of claim 13 , wherein a first continuous short exposure operation performed by the second photodiode occurs right after a first continuous medium exposure operation performed by the second photodiode.

18. The image sensor of claim 17 , wherein the first continuous medium exposure operation and the first continuous short exposure operation occur during the frame.

19. The image sensor of claim 17 , wherein the first continuous medium exposure operation and the first continuous short exposure operation after the first exposure period of the first photodiode.

20. The image sensor of claim 11 , wherein the fragmented medium exposure period is one of evenly divided N parts of the continuous medium exposure period,
wherein the fragmented short exposure period is one of evenly divided M parts of the continuous short exposure period,
wherein each of N and M is a natural number.

Assignees

• Samsung Electronics Co Ltd

Inventors

• Bitan Gal
• Hamami Shay

Classifications

• H04N25/00 Primary

  Circuitry of solid-state image sensors [SSIS]; Control thereof · CPC title

• H04N23/684 Primary

  performed by controlling the image sensor readout, e.g. by controlling the integration time · CPC title

• H04N25/585

  with pixels having different sensitivities within the sensor, e.g. fast or slow pixels or pixels having different sizes · CPC title

• H04N25/771

  comprising storage means other than floating diffusion · CPC title

• H04N23/745 Primary

  Detection of flicker frequency or suppression of flicker wherein the flicker is caused by illumination, e.g. due to fluorescent tube illumination or pulsed LED illumination · CPC title