Infrared cut-off filter

• US 10,156,665 B2
• Filed: 06/01/2016
• Issued: 12/18/2018
• Est. Priority Date: 06/01/2016
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Inventors: Juhola, Mikko
• Primary Examiner(s): Holder, Anner N
• Application Number:
  US15/170,849
• Publication Number:
  US 20170351016A1
• Time in Patent Office: 930 Days
• CPC Class Codes: G02B 1/11 Anti-reflection coatings
• CPC Class Codes: G02B 5/281 designed for the infrared light
• CPC Class Codes: H04N 23/10 for generating image signals from different wavelengths
• CPC Class Codes: H04N 23/55 Optical parts specially adapted for electronic image sensors; Mounting thereof

Abstract

According to an embodiment a device comprises: an image sensor, an optical system comprising at least one lens, and an infrared, IR cut-off filter, transmission characteristics of the IR cut-off filter comprising a ripple with low transmission between wavelengths corresponding to blue and green.

Claims

1. A device, comprising:

an image sensor;

an optical system comprising at least one lens; and

an infrared, IR cut-off filter;

the transmission characteristics of the IR cut-off filter comprising a ripple with a low transmission between wavelengths corresponding to blue and green.

2. The device of claim 1 wherein the transmission characteristics of the IR cut-off filter comprise the ripple with the low transmission in a range chosen between wavelengths 470 nm and 515 nms.

3. The device of claim 1, wherein the transmission characteristics of the IR cut-off filter comprises the ripple with a lowest transmission chosen from the range 30% to 40%.

4. The device of claim 3, wherein the lowest transmission substantially corresponds to a wavelength range chosen between 487 nm to 491 nm.

5. The device of claim 1, wherein the IR cut-off filter comprises a blue glass substrate and multiple IR interference layers on one side and multiple anti-reflective layers on another side.

6. The device of claim 5 wherein the IR cut-off filter comprises less than or equal to 30 IR interference layers.

7. The device of claim 5 wherein the IR cut-off filter comprises less than or equal to 10 Anti-reflective layers.

8. The device of claim 1, wherein the optical system comprises at least three lenses.

9. The device of claim 1, wherein the optical system comprises an image stabilization module and/or an autofocus.

10. The device of claim 1, wherein the image sensor is a complementary metal-oxide semiconductor, CMOS based sensor.

11. A portable device, comprising:

an image sensor;

an optical system comprising at least one lens; and

an infrared, IR cut-off filter;

a response of the image sensor in a green region being greater than standard red green blue, sRGB color space; and

transmission characteristics of the IR cut-off filter comprising a ripple with low transmission between wavelengths corresponding to blue and green.

12. The device of claim 11, wherein the transmission characteristics of the IR cut-off filter normalize the response of the image sensor towards sRGB.

13. The device of claim 11 wherein the transmission characteristics of the IR cut-off filter comprise the ripple with low transmission in a range chosen between wavelengths 470 nm and 515 nms.

14. The device of claim 11, wherein the transmission characteristics of the IR cut-off filter comprises the ripple with a lowest transmission chosen from the range 30% to 40%.

15. The device of claim 14, wherein the lowest transmission substantially corresponds to a wavelength range chosen between 487 nm to 491 nm.

16. The device of claim 11, wherein the IR cut-off filter comprises a blue glass substrate and at most 30 IR interference layers;

or

a resin type absorbing layer;

or

a plastic absorbing substrate.

17. The device of claim 11, wherein the IR cut-off filter comprises at most 10 anti-reflective layers.

18. The device of claim 11, wherein the optical system comprises an image stabilization module.

19. A method comprising:

configuring an image sensor on a substrate, in an enclosure;

configuring an infrared IR cut off filter over the image sensor, in the enclosure, transmission characteristics of the IR cut off filter comprising a ripple with substantially lower transmission of in between wavelengths corresponding to colors blue and green;

configuring an optical system over the image sensor, in the enclosure;

configuring the enclosure on a circuit board comprising at least one processor and storage; and

enclosing the circuit board comprising the enclosure in a casing, such that there is an optical aperture in the casing corresponding to the enclosure.

20. The method according to claim 19, wherein the ripple extends from 487 nm to 491 nm.