Image sensor

• US 6,646,249 B2
• Filed: 10/25/2001
• Issued: 11/11/2003
• Est. Priority Date: 10/26/2000
• Status: Expired due to Fees

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Bird, Neil C.
• Primary Examiner(s): Porta, David
• Assistant Examiner(s): Lee, Patrick J.
• Application Number:
  US10/144,827
• Publication Number:
  US 20020134916A1
• Time in Patent Office: 747 Days
• Field of Search: 348/207, 348/241, 348/294, 348/307-309, 348/311, 348/229, 348/281, 348/283, 348/300, 348/302, 250/370.09, 250/208.1, 250/214.R, 250/214.1, 257/230, 257/233, 257/89, 257/443-445, 438/16, 345/147, 345/204, 382/124, 359/55, 359/68, 359/54, 359/61, 359/58, 340/805, 358/482-483, 357/24
• US Class Current: 250/208.1
• CPC Class Codes: H04N 25/76 Addressed sensors, e.g. MOS or CMOS sensors

Abstract

An image sensor comprises rows and columns of pixels. Each pixel comprises an image sensing element and a switching device. The switching device enables a signal of the image sensing element to be provided to the associated column conductor. The switching device has two inputs—a first input defined by the row conductor, and a second input. Two adjacent columns of pixels are associated with each column conductor, and the two columns of pixels between adjacent column conductors are associated with a respective shared control line providing the second input. The switch arrangement with two inputs enables individual pixels to be isolated. The sharing of control lines between pairs of columns of pixels means that each pixel requires the same number of connections as in a conventional array with only a single switch control input.

Claims

1. An image sensor comprising rows and columns of image sensing pixels, each row of pixels being associated with a respective row conductor, and each column of pixels being associated with a column conductor, each pixel comprising an image sensing element and a switching device, the switching device enabling a signal of the image sensing element to be provided to the associated column conductor, wherein the switching device is controlled by two inputs, a first input defined by the row conductor, and a second input,

characterized in that two adjacent columns of pixels are associated with each column conductor, the two adjacent columns of pixels being located on opposite sides of the column conductor, the column conductors thereby having a pitch of twice the pitch of the pixel columns, and in that the two columns of pixels between adjacent column conductors are associated with a respective shared control line providing the second input.

7. An image sensor as claimed in claim 1, wherein each pixel comprises two series-connected transistors and the image sensing element coupled between the column conductor and a common electrode, the two series-connected transistors defining the switching device.

8. An image sensor as claimed in claim 7, wherein the two inputs to the switching device are coupled to the gates of the two transistors.

9. An image sensor as claimed in claim 7, wherein one of the two series-connected transistors of one pixel also forms one of the two series-connected transistors of an adjacent pixel in the same column.

10. An image sensor as claimed in claim 1, wherein the image sensing element comprises a photodiode.

16. The image sensor of claim 1, wherein each pixel comprises two series-connected transistors and the image sensing element coupled between the column conductor and a common electrode, the two series-connected transistors defining the switching device.

17. The image sensor of claim 16, wherein the two inputs to the switching device are coupled to the gates of the two transistors.

18. The image sensor of claim 16, wherein one of the two series-connected transistors of one pixel also forms one of the two series-connected transistors of an adjacent pixel in the same column.

2. An image sensor comprising rows and columns of image sensing pixels, each row of pixels being associated with a respective row conductor, and each column of pixels being associated with a column conductor, each pixel comprising an image sensing element and a switching device, the switching device enabling a signal of the image sensing element to be provided to the associated column conductor,

wherein the switching device is controlled by two inputs, a first input defined by the row conductor, and a second input,

wherein two adjacent columns of pixels are associated with each column conductor, the two adjacent columns of pixels being located on opposite sides of the column conductor, the column conductors thereby having a pitch of twice the pitch of the pixel columns,

wherein the two columns of pixels between adjacent column conductors are associated with a respective shared control line providing the second input, and

wherein each column conductor is provided with a routing device which is selectively operable to route the signal from the column conductor to a first or a second signal measurement device.

3. An image sensor as claimed in claim 2, wherein the shared control line provides a control signal for the two routing devices of the two columns which are associated with the shared control line, the control signal enabling one of the routing devices to route to the first signal measurement device and the other routing device to route to the second signal measurement device.

4. An image sensor as claimed in claim 3;

wherein each routing device comprises first and second transistors, the first transistor being connected between the column conductor and the first signal measurement device, and the second transistor being connected between the column conductor and the second signal measurement device.

5. An image sensor as claimed in claim 4, wherein the first and second transistors comprise amorphous silicon thin film transistors, and wherein the switching device of each pixel also comprises one or more amorphous silicon thin film transistors.

6. An image sensor as claimed in claim 2, wherein each signal measurement device comprises a charge sensitive amplifier.

11. An image sensor as claimed in claim 2, wherein each pixel comprises two series-connected transistors and the image sensing element coupled between the column conductor and a common electrode, the two series-connected transistors defining the switching device.

12. An image sensor as claimed in claim 11, wherein the two inputs to the switching device are coupled to the gates of the two transistors.

13. An image sensor as claimed in claim 11, wherein one of the two series-connected transistors of one pixel also forms one of the two series-connected transistors of an adjacent pixel in the same column.

14. An image sensor as claimed in claim 2, wherein the image sensing element comprises a photodiode.

15. An image sensor comprising rows and columns of image sensing pixels, each row of pixels being associated with a respective row conductor, and each column of pixels being associated with a column conductor, each pixel comprising an image sensing element and a switching device, the switching device enabling a signal of the image sensing element to be provided to the associated column conductor, wherein:

the switching device is controlled by two inputs, the two inputs including a first input defined by the row conductor, and a second input;

two adjacent columns of pixels are associated with each column conductor, the two adjacent columns of pixels being located on opposite sides of the column conductor, the column conductors thereby having a pitch of twice the pitch of the pixel columns; and

the two columns of pixels between adjacent column conductors are associated with a respective shared control line providing the second input, every pixel of the two columns being associated with the same respective shared control line.

19. The image sensor of claim 15, wherein the image sensing element comprises a photodiode.