Imaging apparatus and imaging method for capturing imaging data via a pixel array

Patent metadata

Field	Value
Publication number	US-10142572-B2
Application number	US-201615196615-A
Country	US
Kind code	B2
Filing date	Jun 29, 2016
Priority date	Jul 29, 2015
Publication date	Nov 27, 2018
Grant date	Nov 27, 2018

Abstract

The present disclosure relates to an imaging apparatus. The imaging apparatus comprises a pixel array. The pixel array comprises a first pixel comprising a first radiation-sensitive region and at least one associated charge storage region for collecting electrical charges from the first radiation-sensitive region. The pixel array also comprises a second pixel comprising a second radiation-sensitive region and at least one associated charge storage region for collecting electrical charges from the second radiation-sensitive region. Furthermore, the imaging apparatus comprises control circuitry configured to generate a common compensation signal being common to the first and second pixels. The common compensation signal mitigates a saturation of the respective charge storage regions of the first and second pixels.

First claim

What is claimed is:

1. An imaging apparatus, comprising:
a pixel array comprising:
a first differential pixel comprising a first radiation-sensitive region and at least one first associated charge storage region for collecting electrical charges from the first radiation-sensitive region, and
a second differential pixel comprising a second radiation-sensitive region and at least one second associated charge storage region for collecting electrical charges from the second radiation-sensitive region; and

a control circuitry configured to:
generate a common compensation signal that is common to the first differential pixel and the second differential pixel,
the common compensation signal to mitigate a saturation of at least one of:
the at least one first associated charge storage region, or
the at least one second associated charge storage region, and

the control circuitry being configured for an open-loop control of the common compensation signal based on a saturation of one or more pixels of the pixel array.

2. The imaging apparatus of claim 1 , wherein the control circuitry is further configured to:
generate a common electrical current to or from the at least one first associated charge storage region and the at least one second associated charge storage region.

3. The imaging apparatus of claim 1 , wherein the control circuitry is a first control circuitry;
wherein the common compensation signal is a first common compensation signal; and
wherein the imaging apparatus comprises a second control circuitry,
the second control circuitry comprising a closed feedback loop to control a second common compensation signal.

4. The imaging apparatus of claim 1 , further comprising:
a reference pixel comprising:
a third radiation-sensitive region,
at least one third associated charge storage region, and
a compensation circuitry configured to generate a reference compensation signal based on an electrical charge in the at least one third associated charge storage region or a quantity derived from the electrical charge,
the reference compensation signal to mitigate a saturation of the at least one third associated charge storage region; and

wherein the control circuitry comprises distribution circuitry configured to distribute the reference compensation signal to the first differential pixel and the second differential pixel.

5. The imaging apparatus of claim 1 , wherein the first radiation-sensitive region is located between two charge storage regions of the at least one first associated charge storage region,
wherein the second radiation-sensitive region is located between two charge storage regions of the at least one second associated charge storage region, and
wherein the first differential pixel and the second differential pixel each comprise at least two modulation gates for generating a varying course of electric potential.

6. The imaging apparatus of claim 1 , wherein the first differential pixel or the second differential pixel is a Time-of-Flight (ToF) pixel.

7. The imaging apparatus of claim 1 , wherein the control circuitry further comprises:
a temperature sensor configured to trigger the common compensation signal if a background temperature exceeds a predefined threshold.

8. The imaging apparatus of claim 1 , wherein the control circuitry further comprises:
a light sensor configured to trigger the common compensation signal if a background illumination exceeds a predefined threshold.

9. The imaging apparatus of claim 1 , wherein the control circuitry further comprises:
a light sensor configured to trigger an increase in a signal strength of the common compensation signal in relation to a background illumination.

10. The imaging apparatus of claim 1 , wherein the first differential pixel or the second differential pixel comprises at least one reset transistor coupled between the at least one first associated charge storage region or the at least one second associated charge storage region and a reset potential and
wherein the control circuitry is further configured to:
provide the common compensation signal to the at least one first associated charge storage region or the at least one second associated charge storage region via the at least one reset transistor of the first differential pixel or the second differential pixel.

11. The imaging apparatus of claim 10 , wherein the reset potential is in a range between 0.3 VDDA to 0.7 VDDA, and
wherein VDDA denotes a supply voltage of the first differential pixel or the second differential pixel.

12. The imaging apparatus of claim 10 , wherein the control circuitry is further configured to:
provide the common compensation signal and a reset signal for the at least one reset transistor via a common signal line.

13. The imaging apparatus of claim 10 , wherein the common compensation signal provided to the at least one reset transistor causes an equal electrical compensation current that is common to the first differential pixel and the second differential pixel to or from the at least one first associated charge storage region and the at least one second associated charge storage region.

14. The imaging apparatus of claim 10 , wherein the control circuitry is further configured to:
apply the common compensation signal to a control terminal of the at least one reset transistor.

15. The imaging apparatus of claim 14 , wherein the control circuitry is further configured to:
apply the common compensation signal to the control terminal between subsequent predefined reset signals.

16. A Time of Flight (ToF) imaging apparatus, comprising:
a ToF pixel array comprising:
a first differential pixel comprising:
a first light-sensitive semiconductor region, and
at least one first associated charge storage region for collecting electrical charges from the first light-sensitive semiconductor region and at least a first reset transistor coupled between the at least one first associated charge storage region and a reset potential;

a second differential pixel comprising:
a second light-sensitive semiconductor region, and
at least one second associated charge storage region for collecting electrical charges from the second light-sensitive semiconductor region and at least a second reset transistor coupled between the at least one second associated charge storage region and the reset potential; and

a control circuitry configured to:
generate a common compensation signal that is common to the first differential pixel and the second differential pixel,
the common compensation signal to mitigate a saturation of at least one of:
 the at least one first associated charge storage region, or
 the at least one second associated charge storage region,

the control circuitry being configured to provide the common compensation signal to the first light-sensitive semiconductor region and the second light-sensitive semiconductor region via the at least the first reset transistor and the at least the second reset transistor, and
the control circuitry being configured for an open-loop control of the common compensation signal based on a saturation of one or more pixels of the ToF pixel array.

17. The ToF imaging apparatus of claim 16 , wherein the control circuitry further comprises:
a temperature sensor configured to trigger the common compensation signal if a background temperature exceeds a predefined threshold.

18. The ToF imaging apparatus of claim 16 , wherein the control circuitry further comprises:
a light sensor configured to trigger the common compensa

Assignees

• Infineon Technologies Ag

Inventors

• Dielacher Markus
• Flatscher Martin
• Gansinger Stefan
• Mark Michael
• Prainsack Josef
• Unterassinger Hartwig

Classifications

• H04N25/771

  comprising storage means other than floating diffusion · CPC title

• H04N25/71 Primary

  Charge-coupled device [CCD] sensors; Charge-transfer registers specially adapted for CCD sensors · CPC title

• H04N25/77

  Pixel circuitry, e.g. memories, A/D converters, pixel amplifiers, shared circuits or shared components · CPC title

• H04N25/59

  by controlling the amount of charge storable in the pixel, e.g. modification of the charge conversion ratio of the floating node capacitance · CPC title

• G01S7/497

  Means for monitoring or calibrating · CPC title