Camera system comprising a camera, camera, method of operating a camera and method for deconvoluting a recorded image

Patent metadata

Field	Value
Publication number	US-9826161-B2
Application number	US-201514959460-A
Country	US
Kind code	B2
Filing date	Dec 4, 2015
Priority date	Mar 22, 2011
Publication date	Nov 21, 2017
Grant date	Nov 21, 2017

Abstract

A system and camera wherein the camera comprises in the light path a diffuser ( 4 ). The system or camera comprises a means ( 6 ) to modulate the diffusing properties of the diffuser ( 4 ) on an image projected by the lens on the sensor during exposure of the image. To the captured blurred image ( 10 ) an inverse point spread function is applied to deconvolute ( 24 ) the blurred image to a sharper image. Motion invariant image can so be achieved.

First claim

The invention claimed is:

1. A camera system comprising:
a camera with a lens, an image sensor, and a shutter, the shutter configured to open to begin an individual exposure of an image on the sensor and close to end the individual exposure;
a liquid crystal diffuser in a light path of the camera;
a diffuser driver configured to electronically drive the liquid crystal diffuser to vary an amount of diffusion by the liquid crystal diffuser on light received by the camera system projected by the lens on the sensor throughout a duration of the individual exposure of the image on the sensor, the diffuser driver configured to drive the liquid crystal diffuser to vary the amount of diffusion starting before the shutter is opened and continue driving the liquid crystal diffuser to vary the amount of diffusion until after the shutter closes; and
a controller configured to synchronize the diffuser driver and the amount of diffusion with the exposure to vary the amount of diffusion throughout the duration of the exposure.

2. A camera system as claimed in claim 1 , wherein the diffuser driver dynamically changes diffusing properties of the liquid crystal diffuser in synchronicity with the exposure.

3. A camera system as claimed in claim 1 , wherein the diffuser driver is arranged to, during the individual exposure, drive the liquid crystal diffuser gradually between a diffusing state and a transparenet state.

4. A camera system as claimed in claim 3 , further comprising a controller configured to cause the diffuser driver to electronically drive the liquid crystal diffuser.

5. A camera system as claimed in claim 4 wherein the controller is configured such that parameters of the diffuser driver are set manually.

6. A camera system as claimed in claim 4 , wherein the diffuser driver is configured to establish the speed and/or the distance to the camera of an object to be recorded and wherein the controller is arranged to obtain a signal from the diffuser driver that communicates information related to the speed and/or the distance to the camera of the object.

7. A camera system as claimed in claim 6 , further comprising a deconvolutor configured to deconvolute a recorded image, wherein the recorded image is deconvoluted with an inverse point spread function (IPSF).

8. A camera system as claimed in claim 7 wherein the liquid crystal diffuser is positioned in front of the lens.

9. A camera system as claimed in claim 7 wherein the liquid crystal diffuser is positioned in between the lens and the sensor.

10. A camera for a camera system as claimed in claim 9 .

11. A camera system as claimed in claim 1 wherein the system comprises a means for moving the diffuser in synchronicity with the exposure.

12. A camera system as claimed in claim 1 , wherein the liquid crystal diffuser is comprised of a Liquid Crystals (LC) layer, a planar electric field modulating layer, two transparent electrodes, and two transparent glass or plastic substrates, the LC layer and the planar electric field modulating layer being interposed between the two transparent electrodes, which are in turn interposed between the two transparent substrates.

13. A camera system as claimed in claim 12 , wherein the planar electric field modulating layer has a uniform refraction index and a non-uniform dielectric transparency index, and wherein at least one of the two transparent electrodes is a planar grid electrode printed on one of the two transparent glass or plastic substrates, the planar grid electrode having a grid size that corresponds to a thickness of the one of the two transparent glass or plastic substrates on which the planar grid electrode is printed.

14. A camera system as claimed in claim 1 , wherein the diffuser driver is configured such that the liquid crystal diffuser is time multiplexed during the individual exposure between a transparent state and a diffusing state, and wherein a ratio between the transparent and diffusing states is a function of time, in synchronicity with the individual exposure, ranging from diffuse at a beginning of the individual exposure, to transparent at a middle of the individual exposure, and back to diffuse at an end of the individual exposure.

15. A method of operating a camera, wherein the camera comprises a lens, an image sensor, a shutter, and a liquid crystal diffuser in a light path of the camera, the shutter configured to open to begin an individual exposure of an image on the sensor and close to end the individual exposure, the method comprising:
electronically driving the liquid crystal diffuser during the individual exposure for image acquisition to vary an amount of diffusion by the liquid crystal diffuser on light received by the camera projected by the lens on the sensor throughout a duration of the individual exposure, the amount of diffusion varied starting before the shutter is opened and continuing until after the shutter closes; and
synchronizing the amount of diffusion with the exposure to vary the amount of diffusion throughout the duration of the exposure.

16. A method as claimed in claim 15 , wherein the amount of diffusion depends on signals conveying information corresponding to a speed and/or a distance to the lens of a recorded object.

17. A method as claimed in claim 15 , wherein the liquid crystal diffuser is comprised of a Liquid Crystals (LC) layer, a planar electric field modulating layer, two transparent electrodes, and two transparent glass or plastic substrates, the LC layer and the planar electric field modulating layer being interposed between the two transparent electrodes, which are in turn interposed between the two transparent substrates.

18. A method as claimed in claim 17 , wherein the planar electric field modulating layer has a uniform refraction index and a non-uniform dielectric transparency index, and wherein at least one of the two transparent electrodes is a planar grid electrode printed on one of the two transparent glass or plastic substrates, the planar grid electrode having a grid size that corresponds to a thickness of the one of the two transparent glass or plastic substrates on which the planar grid electrode is printed.

19. A method as claimed in claim 15 , wherein the liquid crystal diffuser is time multiplexed during the individual exposure between a transparent state and a diffusing state, and wherein a ratio between the transparent and diffusing states is a function of time, in synchronicity with the individual exposure, ranging from diffuse at a beginning of the individual exposure, to transparent at a middle of the individual exposure, and back to diffuse at an end of the individual exposure.

20. A method for deconvoluting image data recorded by a camera comprising a lens, a shutter, an image sensor, and a liquid crystal diffuser in a light path of the camera, the shutter configured to open to begin an individual exposure of an image on the sensor and close to end the individual exposure,
wherein during image acquisition the liquid crystal diffuser is electronically driven to vary an amount of diffusion by the liquid crystal diffuser on light received by the camera projected by the lens on the sensor throughout a duration of the individual exposure of the image on the image sensor, the liquid crystal diffuser being electronically driven to vary the amount of diffusion starting before the shutter is opened and continue driving the liquid crystal diffuser to vary the amount of diffusion until after the shutter closes, and
wherein an inverse point spread function (IPSF) is app

Assignees

• Koninklijke Philips Nv

Inventors

• Znamenskiy Dmitry Nikolayevich
• Rajagopalan Ruben
• Hikmet Rifat Ata Mustafa

Classifications

• H04N23/682 Primary

  Vibration or motion blur correction · CPC title

• H04N23/683 Primary

  performed by a processor, e.g. controlling the readout of an image memory · CPC title

• H04N23/73

  by influencing the exposure time · CPC title

• G02F1/137

  characterised by the electro-optical or magneto-optical effect, e.g. field-induced phase transition, orientation effect, guest-host interaction or dynamic scattering · CPC title

• H04N5/2353

  Electricity · mapped topic