Hybrid image sensor

• US 9,549,099 B2
• Filed: 03/12/2013
• Issued: 01/17/2017
• Est. Priority Date: 03/12/2013
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Fan, Xiaofeng
• Primary Examiner(s): Ye, Lin
• Assistant Examiner(s): YODER III, CHRISS S
• Application Number:
  US13/797,851
• Publication Number:
  US 20140267855A1
• Time in Patent Office: 1,407 Days
• Field of Search: 348/294, 348/296, 348/301, 348/302, 348/308, 348/309, 348/310, 250/208.1, 257/40, 341/155
• US Class Current: 1/1
• CPC Class Codes: H01L 27/14609 Pixel-elements with integrated switching, control, storage or amplification elements scanning details of imagers (circuitry of solid-state image sensors H04N25/00); circuitry of imagers H04N25/70
• CPC Class Codes: H01L 27/14806 Structural or functional details thereof
• CPC Class Codes: H04N 25/00 Circuitry of solid-state image sensors [SSIS]; Control thereof
• CPC Class Codes: H04N 25/59 by controlling the amount of charge storable in the pixel, e.g. modification of the charge conversion ratio of the floating node capacitance
• CPC Class Codes: H04N 25/616 involving a correlated sampling function, e.g. correlated double sampling [CDS] or triple sampling
• CPC Class Codes: H04N 25/75 Circuitry for providing, modifying or processing image signals from the pixel array
• CPC Class Codes: H04N 25/771 comprising storage means other than floating diffusion
• CPC Class Codes: H04N 3/155 Control of the image-sensor operation, e.g. image processing within the image-sensor

Abstract

A method for performing correlated double sampling for a sensor, such as an image sensor. The method includes collecting a first charge corresponding to a first parameter, transferring the first charge to a first storage component, transferring the first charge from the first storage component to a second storage component, resetting the first storage component, transferring the first charge from the second storage component to the first storage component, and reading the first storage component to determine the first charge. The method may be implemented in electronic devices including image sensors.

Claims

1. A method for performing correlated double sampling for an image sensor, comprising:

collecting a first charge corresponding to light;

resetting the first storage component;

reading the first storage component;

transferring the first charge to the first storage component;

reading the first storage component to determine the first charge;

determining if additional correlated double sampling is to be performed;

if the additional correlated double sampling is to be performed, increasing a potential of a variable potential second storage component and transferring the first charge from the first storage component to the variable potential second storage component;

collecting a second charge corresponding to light;

resetting the first storage component;

reading the first storage component;

transferring the second charge to the first storage component;

decreasing the potential of the variable potential second storage component and transferring the first charge from the variable potential second storage component to the first storage component to combine the first charge with the second charge; and

reading the first storage component to determine the combined first and second charge.

2. The method of claim 1, wherein the variable potential is determined by a voltage applied to the variable potential second storage component.

3. The method of claim 1, wherein the first storage component has a set potential.

4. The method of claim 3, wherein the set potential is determined by a characteristic of a material forming the first storage component.

5. The method of claim 1, further comprising:

after reading the first storage component to determine the combined first and second charge, determining if additional correlated double sampling is to be performed;

if the additional correlated double sampling is to be performed, increasing the potential of the variable potential second storage component and transferring the combined first and second charge to the variable potential second storage component;

collecting a third charge corresponding to light;

resetting the first storage component;

reading the first storage component;

transferring the third charge to the first storage component;

decreasing the potential of the variable potential second storage component and transferring the combined first and second charge from the variable potential second storage component to the first storage component to combine the first and second charge with the third charge; and

reading the first storage component to determine the combined first charge, second charge and the third charge.

6. The method of claim 5, further comprising:

prior to transferring the combined first and second charge from the variable potential second storage component to the first storage component to combine the first and second charge with the third charge,

reading the first storage component to determine the third charge.

7. The method of claim 1, wherein reading the first storage component to determine the first charge is performed by a processor.

8. The method of claim 1, further comprising:

prior to transferring the first charge to the first storage component,

transferring the first charge to an auxiliary storage component; and

transferring the first charge from the auxiliary storage component to the first storage component after the first storage component has been reset and read.

9. The method of claim 6, further comprising:

prior to transferring the first charge from the variable potential second storage component to the first storage component to combine the first charge with the second charge,

reading the first storage component to determine the second charge.