Reference data coding in solid state image sensors

• US 20020114526A1
• Filed: 02/07/2002
• Published: 08/22/2002
• Est. Priority Date: 02/08/2001
• Status: Active Grant

• Current Assignee: STMicroelectronics Limited (STMicroelectronics NV)
• Original Assignee: STMicroelectronics Limited (STMicroelectronics NV)
• Inventors: Dennis, Carl
• Granted Patent: US 6,812,058 B2
• Time in Patent Office: Days
• US Class Current: 382/232
• CPC Class Codes: H01L 27/14621 Colour filter arrangements
• CPC Class Codes: H01L 27/14627 Microlenses

Abstract

Data is encoded in a solid state image sensor that includes a sensor pixel array by varying the color processing applied to at least some of the border pixels of the sensor pixel array. Data may be encoded in the color processing by varying the pattern of a color filter mosaic and by varying a pattern of a microlens array in accordance with a predetermined scheme. This scheme includes omission of color filter material and omission of the microlens array from selected pixels. The data, typically encoded in a binary format, is read by illuminating the sensor pixel array and by processing the output signals from the border pixels. The encoded data may include color process codes, mask revision codes and product codes.

Claims

1. A method of encoding data in a solid state image sensor, said sensor comprising an array of pixels including a plurality of border pixels with color processing applied to said array of pixels, the method comprising varying the color processing applied to at least some of said border pixels in accordance with a predetermined scheme such that data is encoded in the color processing applied to said border pixels.

2. A method as claimed in claim 1, wherein the color processing includes the application of a color filter mosaic to said array of pixels and said data is encoded by means of varying the pattern of color filter material applied to said border pixels.

3. A method as claimed in claim 2, wherein said data is encoded by the omission of color filter material from selected border pixels.

4. A method as claimed in claim 2, wherein said data is encoded by the application of multiple color filter layers to selected border pixels.

5. A method as claimed in any one of claims 2 to 4, wherein said color filter mosaic comprises a Bayer pattern mosaic and wherein one bit of binary data is encoded in two adjacent blocks of four pixels of said pattern by varying the color filter material applied to one pixel of one of said two adjacent blocks.

6. A method as claimed in claim 1, wherein the color processing includes the application of a microlens array to said array of pixels and said data is encoded by means of varying the pattern of microlenses applied to said border pixels.

7. A method according to any preceding claim, wherein the encoded data includes a color process code.

8. A method according to any preceding claim wherein the encoded data includes a mask revision code.

9. A method according to any preceding claim, wherein the encoded data includes a product code.

10. A method according to any preceding claim, wherein the encoded data includes at least one of a start code and an end code.

11. A method of reading data encoded using the method of any one of claims 1 to 10, comprising illuminating the image sensor and interpreting signals output from said border pixels.

12. A method as claimed in claim 11, further including a step of electronically storing said data in said image sensor or in an image sensor system incorporating said image sensor.

14. An image sensor as claimed in claim 13, wherein said data is encoded by means of a method as claimed in any one of claims 1 to 10.

15. An image sensor as claimed in claim 13 or claim 14, or an image sensor system incorporating said image sensor, adapted to read said data encoded in said color processing when the image sensor is illuminated.

16. An image sensor or an image sensor system as claimed in claim 15, including storage means for electronically storing said data.

13. A solid state image sensor comprising an array of pixels including a plurality of border pixels with color processing applied to said array of pixels, said image sensor including data encoded in the color processing applied to at least some of said border pixels.