Wide dynamic range using monochromatic sensor

• US 9,621,817 B2
• Filed: 11/28/2016
• Issued: 04/11/2017
• Est. Priority Date: 07/26/2012
• Status: Active Grant

• Current Assignee: Depuy Synthes Products Incorporated (Johnson & Johnson)
• Original Assignee: Depuy Synthes Products Incorporated (Johnson & Johnson)
• Inventors: Blanquart, Laurent, Richardson, John
• Primary Examiner(s): AYNALEM, NATHNAEL B
• Application Number:
  US15/362,512
• Publication Number:
  US 20170078548A1
• Time in Patent Office: 134 Days
• Field of Search: 348 65, 348 68, 34820899, 348234, 348241, 348317, 348362
• CPC Class Codes: A61B 1/045 Control thereof
• CPC Class Codes: A61B 1/0605 for spatially modulated illumination
• CPC Class Codes: H04N 13/239 using two 2D image sensors having a relative position equal to or related to the interocular distance H04N13/243 takes precedence
• CPC Class Codes: H04N 2209/042 having a single pick-up sensor
• CPC Class Codes: H04N 23/10 for generating image signals from different wavelengths
• CPC Class Codes: H04N 23/12 with one sensor only
• CPC Class Codes: H04N 23/56 provided with illuminating means
• CPC Class Codes: H04N 23/74 by influencing the scene brightness using illuminating means
• CPC Class Codes: H04N 23/741 by increasing the dynamic range of the image compared to the dynamic range of the electronic image sensors
• CPC Class Codes: H04N 23/843 Demosaicing, e.g. interpolating colour pixel values
• CPC Class Codes: H04N 25/10 for transforming different wavelengths into image signals
• CPC Class Codes: H04N 25/58 involving two or more exposures
• CPC Class Codes: H04N 25/583 with different integration times
• CPC Class Codes: H04N 25/585 with pixels having different sensitivities within the sensor, e.g. fast or slow pixels or pixels having different sizes
• CPC Class Codes: H04N 25/70 SSIS architectures; Circuits associated therewith
• CPC Class Codes: H04N 25/778 comprising amplifiers shared between a plurality of pixels, i.e. at least one part of the amplifier must be on the sensor array itself

Abstract

A system for digital imaging in a light deficient environment includes an emitter for providing illumination with electromagnetic pulses. The system includes an image sensor that creates image data from the electromagnetic pulses. The image sensor has a plurality of subsets of differing pixels, where each of the pixels comprises a transfer gate transistor. Each transfer gate transistor in one subset of pixels is electrically connected by a TX signal. The TX signal provides global operation of transfer gate transistor (TX) per subset of pixels. The system includes a memory comprising instructions for controlling the emitter so as to pulse for a plurality of exposures that correspond to the subsets of differing pixels and instructions that coordinate the electromagnetic pulses being emitted during a blanking portion of the image sensor frame period. The system includes a processor that combines a plurality of exposures to expand dynamic range.

Claims

1. A system for digital imaging in a light deficient environment comprising:

an emitter for providing illumination in electromagnetic pulses;

an image sensor that is sensitive to the electromagnetic pulses and creates image data therefrom;

wherein said image sensor comprises a plurality of subsets of differing pixels;

wherein each of the pixels comprises a transfer gate transistor;

wherein each transfer gate transistor in one subset of pixels are electrically connected together by a TX signal;

wherein the TX signal provides global operation of transfer gate transistor (TX) per subset of pixels;

a memory comprising instruction for controlling the emitter so as to pulse for a plurality of exposures that correspond to the subsets of differing pixels;

wherein said memory further comprises instructions that coordinate the pulses to be emitted during a predefined portion of the image sensor frame period during which pulse sensitive pixels are not read; and

wherein a processor combines the plurality of exposures to expand dynamic range.

2. The system of claim 1, wherein said emitter comprises lasers.

3. The system of claim 1, wherein said emitter comprises light emitting diodes.

4. The system of claim 1, wherein the image sensor is a monochromatic sensor.

5. The system of claim 4, wherein the plurality of subsets of pixels are arranged in a checker board pattern.

6. The system of claim 1, wherein two pixels share a floating diffusion.

7. The system of claim 1, wherein four pixels share a floating diffusion.

8. The system of claim 5, wherein two pixels share a floating diffusion in the horizontal direction in a 2-way pixel share, wherein the TX signal comprises a TX1 signal and a TX2 signal.

9. The system of claim 8, wherein the TX1 signal attaches the transfer gate transistor (TX) of pixels located on a left side of the 2-way pixel share on odd rows, and the transfer gate transistor (TX) of pixels located on a right side of the 2-way pixel share on even rows, and the TX2 signal attaches the transfer gate transistor (TX) of pixels located on the right side of the 2-way pixel share on odd rows, and the transfer gate transistor (TX) of pixels located on the left side of the 2-way pixel share on even rows.

10. The system of claim 9, wherein the global operation of the TX1 signal and the TX2 signal is performed during a predefined portion of the image sensor frame period during which pulse sensitive pixels are not read.

11. The system of claim 1, wherein the image sensor excludes a Bayer pattern.