Confocal imaging device using spatially modulated illumination with electronic rolling shutter detection

• US 8,237,835 B1
• Filed: 11/22/2011
• Issued: 08/07/2012
• Est. Priority Date: 05/19/2011
• Status: Active Grant

• Current Assignee: Aeon Imaging, LLC
• Original Assignee: Aeon Imaging, LLC
• Inventors: Muller, Matthew Stefan
• Primary Examiner(s): VILLECCO, JOHN M
• Application Number:
  US13/302,814
• Time in Patent Office: 259 Days
• Field of Search: 348/78, 348/77, 348/296, 382/117, 250/201.9, 351/206, 351/214, 351/215, 600/452
• US Class Current: 348/296
• CPC Class Codes: A61B 3/1025 for confocal scanning
• CPC Class Codes: G01J 3/0208 using focussing or collimating elements, e.g. lenses or mirrors; performing aberration correction
• CPC Class Codes: G01J 3/0224 using polarising or depolarising elements
• CPC Class Codes: G01J 3/0229 using masks, aperture plates, spatial light modulators or spatial filters, e.g. reflective filters
• CPC Class Codes: G01J 3/0232 using shutters
• CPC Class Codes: G01J 3/2803 using photoelectric array detector
• CPC Class Codes: G01J 3/2889 Rapid scan spectrometers; Time resolved spectrometry
• CPC Class Codes: G01J 3/513 having fixed filter-detector pairs
• CPC Class Codes: G02B 21/0032 Optical details of illumination, e.g. light-sources, pinholes, beam splitters, slits, fibers G02B21/0036 - G02B21/008; means for illumination of specimens in general G02B21/06
• CPC Class Codes: G02B 21/004 fixed arrays, e.g. switchable aperture arrays
• CPC Class Codes: G02B 21/0064 multi-spectral or wavelength-selective arrangements, e.g. wavelength fan-out, chromatic profiling G02B21/0076 takes precedence
• CPC Class Codes: G02B 21/008 Details of detection or image processing, including general computer control
• CPC Class Codes: G02B 21/14 affording illumination for phase-contrast observation
• CPC Class Codes: H04N 25/531 by controlling rolling shutters in CMOS SSIS

Abstract

A digital imaging device comprising a light source, a pixel array detector having a rolling shutter functionality, a spatial light modulator configured to produce one or more modulation patterns during a frame exposure of the pixel array detector, and at least one timing signal configured to control a spatial-temporal relationship between a rolling shutter of the pixel array detector and the one or more modulation patterns provided by the spatial light modulator.

Claims

1. A digital imaging device, comprising:

a digital light projector operable in a structured light illumination mode that is capable of converting a plurality of color or grayscale brightness values having a first frame rate to a limited number of brightness values having a second frame rate exceeding the first frame rate;

a pixel array detector having a rolling shutter functionality;

and

at least one timing signal configured to control a spatial-temporal relationship between a rolling shutter of the pixel array detector and one or more illumination patterns provided by the digital light projector.

2. The device of claim 1, wherein the pixel array detector is a complementary metal-oxide semiconductor (“

CMOS”

) sensor.

3. The device of claim 1, further comprising one or more additional digital light projectors.

4. The device of claim 1, wherein the rolling shutter of the pixel array detector is configured to perform at least one of the following filtering functions:

a) spatial filtering of at least one of light returning from a target and light passing through the target;

b) filtering at least one of the angle of light returning from the target and the angle of light passing through the target;

c) filtering spatially separated polarization components of at least one of light returning from the target and light passing through the target; and

d) filtering spatially separated frequency components of at least one of light returning from the target and light passing through the target.

5. The device of claim 4, further comprising an anisotropic material configured to spatially separate the polarization components of light returning from the target.

6. The device of claim 4, further comprising a dispersive component configured to spatially separate the frequency components of light returning from the target.

7. The device of claim 4, further comprising one or more additional pixel array detectors each having a rolling shutter functionality, wherein the one or more additional pixel array detectors each have a rolling shutter configured to perform one or more of the filtering functions.

8. The device of claim 4, further comprising a wavefront controller configured to modify a wavefront of light returning from a target.

9. The device of claim 1, further comprising one or more apertures or filters configured to at least partially restrict light traveling from the digital light projector to a target or light traveling from the target to the pixel array detector.

10. A method for digital imaging, the method comprising the steps of:

operating a digital light projector in a structured illumination mode to produce one or more illumination patterns during a frame exposure of a pixel array detector having a rolling shutter functionality, wherein the structured light illumination mode is capable of converting a plurality of color or grayscale brightness values having a first frame rate to a limited number of brightness values having a second frame rate exceeding the first frame rate;

directing light from the produced one or more illumination patterns onto a target;

directing light from the target to the pixel array detector having rolling shutter functionality; and

using at least one timing signal to control a spatial-temporal relationship between a rolling shutter of the pixel array detector and the one or more illumination patterns provided by the digital light projector.

11. The method of claim 10, further comprising using the rolling shutter of the pixel array detector to perform at least one of the following filtering functions:

a) spatial filtering of at least one of light returning from the target and light passing through the target;

b) filtering at least one of the angle of light returning from the target and the angle of light passing through the target;

c) filtering spatially separated polarization components of at least one of light returning from the target and light passing through the target; and

d) filtering spatially separated frequency components of at least one of light returning from the target and light passing through the target.

12. The method of claim 11, further comprising using an anisotropic material to spatially separate the polarization components of light returning from the target.

13. The method of claim 11, further comprising using a dispersive component to spatially separate the frequency components of light returning from the target.

14. The method of claim 11, further comprising using one or more additional pixel array detectors each having a rolling shutter functionality to perform one or more of the filtering functions.

15. The method of claim 10, wherein the step of directing the produced one or more illumination patterns onto the target comprises establishing a known relationship between an illumination pattern and the angle of light directed onto the target.

16. The method of claim 10, wherein the step of directing light from the target to the pixel array detector comprises directing light from the target to a complementary metal-oxide semiconductor (“

CMOS”

) sensor with rolling shutter functionality.

17. The method of claim 10, wherein a portion of light being directed from the digital light projector to the target is directed to a reference pathway of known optical path length.

18. The method of claim 17, wherein a portion of light from the reference pathway is directed to the pixel array detector.

19. The method of claim 10, further comprising using a wavefront controller to modify a wavefront of light returning from the target.

20. The method of claim 19, wherein a portion of light directed from the target to the pixel array detector is directed to a wavefront detector.

21. The method of claim 20, further comprising using wavefront data obtained by the wavefront detector to modify the wavefront of light returning from the target using the wavefront controller.

22. The method of claim 10, further comprising using image data obtained by the pixel array detector to adjust one or more of the following:

(a) an illumination pattern produced by the digital light projector;

(b) timing synchronization between the illumination pattern and the rolling shutter of the pixel array detector;

(c) operating parameters of the pixel array detector, the operating parameters being selected from frame rate, gain, rolling shutter width and pixel region of interest; and

(d) operating parameters of one or more light sources, the operating parameters being selected from driving current, driving frequency, driving phase, driving pulse width, and duty cycle.

23. A method for digital imaging, the method comprising the steps of:

illuminating a spatial light modulator with one or more light sources, the illuminated spatial light modulator producing one or more modulation patterns during a frame exposure of a pixel array detector having a rolling shutter functionality;

directing light from the produced one or more modulation patterns onto a target;

directing light from the target to the pixel array detector having rolling shutter functionality;

using at least one timing signal to control a spatial-temporal relationship between a rolling shutter of the pixel array detector and the one or more modulation patterns provided by the spatial light modulator;

using a wavefront controller to modify a wavefront of light returning from the target; and

using image data obtained by the pixel array detector to modify the wavefront of light returning from the target using the wavefront controller.