CN-122003625-A - Camera module with micro-scale optical absorption grating

Abstract

Embodiments described herein relate to camera modules that incorporate an optical absorption grating positioned and designed to reduce the effect of stray light on images captured by the camera module. Specifically, the optical absorption grating is configured to absorb light incident on the optical absorption grating. The optical absorption grating includes an array of protrusions and may in some cases be part of a grating assembly coupled to the optical component.

Inventors

• SHINOHARA YOSHIKAZU
• ZHANG CHENGLIN
• A. Halabica
• WANG LIGANG
• YAO YUHONG

Assignees

• 苹果公司

Dates

Publication Date

20260508

Application Date

20241007

Priority Date

20240617

Claims (20)

1. 1. A camera module, the camera module comprising: An image sensor; An optical assembly including an optical component and configured to direct light toward the image sensor, and A grating assembly coupled to the optical component, the grating assembly comprising: A substrate; an adhesive connecting the substrate to the optical component, and A grating formed of an optically absorbing material and positioned on a top surface of the substrate, wherein the grating comprises an array of protrusions.
2. 2. The camera module of claim 1, wherein the array of protrusions is a two-dimensional array.
3. 3. The camera module of claim 2, wherein: The two-dimensional array includes a first column including a first plurality of protrusions and a second column including a second plurality of protrusions, and The first columns are staggered with respect to the second columns.
4. 4. The camera module of claim 2, wherein each protrusion in the array of protrusions has a pyramid shape.
5. 5. The camera module of claim 1, wherein the array of protrusions is a one-dimensional array.
6. 6. The camera module of claim 1, wherein the optical component is separated from the grating by an air gap.
7. 7. The camera module of claim 1, wherein the optical component is a prism.
8. 8. A camera module, the camera module comprising: An image sensor; An optical assembly comprising a prism formed of an optically transparent material, wherein the optical assembly is configured such that light entering the optical assembly is reflected from a surface of the prism via total internal reflection, and An optical absorption grating positioned to face the surface, wherein the grating comprises an array of protrusions.
9. 9. The camera module of claim 8, wherein: Each protrusion in the array of protrusions has a height of at least 15 μm.
10. 10. The camera module of claim 8, comprising a substrate, wherein the optical absorption grating is positioned on a top surface of the substrate.
11. 11. The camera module of claim 10, wherein the array of protrusions is at least partially formed from the substrate.
12. 12. The camera module of claim 11, the optical absorption grating comprising a coating of an optical absorption material positioned on the top surface of the substrate.
13. 13. The camera module of claim 8, wherein each protrusion in the array of protrusions has a triangular cross-sectional shape.
14. 14. The camera module of claim 8, wherein each protrusion in the array of protrusions is a cone.
15. 15. A camera module, the camera module comprising: An image sensor; An optical component configured to direct light to the image sensor; a grating assembly positioned to face a surface of the optical component, the grating assembly comprising: A substrate, and An optical absorption grating positioned on a surface of the substrate and comprising an array of protrusions.
16. 16. The camera module of claim 15, wherein the protrusions in the array of protrusions are pyramids.
17. 17. The camera module of claim 15, wherein: The grating assembly is coupled to the optical component.
18. 18. The camera module of claim 15, wherein the width of the protrusions in the array of protrusions is between 40 μιη to 100 μιη.
19. 19. The camera module of claim 15, wherein the array of protrusions is a one-dimensional array.
20. 20. The camera module of claim 15, wherein: Wherein the array of protrusions is a one-dimensional array.

Description

Camera module with micro-scale optical absorption grating Cross Reference to Related Applications The present patent cooperation treaty patent application claims priority from U.S. non-provisional patent application Ser. No. 18/745,983, filed on day 17, 6, 2024, which claims the benefit of U.S. provisional patent application Ser. No. 63/543,684, filed on day 11, 10, 2023, the contents of which are incorporated herein by reference in their entirety as if fully disclosed herein. Technical Field Embodiments described herein relate to camera modules, and in particular, to camera modules including an optical absorption grating configured to absorb light and diffuse reflected light that is not absorbed by the absorption grating. Background Cameras remain an important feature of consumer electronics devices such as smartphones, tablets and computers. Stray light (which may be generated by light reflected from surfaces within the camera module or entering the camera module through unintended paths) may negatively affect the image captured by the camera module. For example, stray light may cause lens halation or other artifacts in the captured image. Accordingly, it is desirable to provide stray light mitigation for camera modules. Disclosure of Invention Embodiments described herein relate to a camera module including an optical absorption grating. Some embodiments relate to a camera module including an image sensor, an optical assembly including an optical component and configured to direct light toward the image sensor, and a grating assembly coupled to the optical component. The grating assembly may include a substrate, an adhesive connecting the substrate to the optical component, and a grating formed of an optically absorptive material and positioned on a top surface of the substrate. The grating includes an array of protrusions. In some variations, the array of protrusions is a two-dimensional array. In some of these variations, the two-dimensional array includes a first column having a first plurality of protrusions and a second column having a second plurality of protrusions. The first columns are staggered with respect to the second columns. Additionally or alternatively, each protrusion in the array of protrusions has a pyramid shape. In other variations, the array of protrusions is a one-dimensional array. The optical component is separated from the grating by an air gap. In some variations, the optical component is a prism. Other embodiments relate to a camera module including an image sensor and an optical assembly including a prism formed of an optically transparent material, wherein the optical assembly is configured such that light entering the optical assembly is reflected from a surface of the prism via total internal reflection. The camera module includes an optical absorption grating positioned to face the surface, wherein the grating includes an array of protrusions. In some variations, each protrusion in the array of protrusions has a height of at least 15 microns. In some variations, the camera module includes a substrate, wherein the optical absorption grating is positioned on a top surface of the substrate. In some of these variations, the array of protrusions is at least partially formed from a substrate. The optical absorption grating may include a coating of an optical absorption material positioned on a top surface of the substrate. In some variations, some or all of the protrusions in the array of protrusions have a triangular cross-sectional shape. In other variations, some or all of the protrusions in the array of protrusions are cones. Still other embodiments relate to a camera module having an image sensor, an optical component configured to direct light to the image sensor, and a grating assembly positioned to face a surface of the optical component. The grating assembly includes a substrate and an optical absorption grating positioned on a surface of the substrate and including an array of protrusions. In some variations, the protrusions in the array of protrusions are pyramids. Additionally or alternatively, the grating assembly is coupled to the optical component. In some examples, the height of the protrusions is between 40 μm and 100 μm. In some variations, the array of protrusions is a one-dimensional array. In other variations, the array of protrusions is a two-dimensional array. In some variations, the optical absorption grating defines an irregular pattern. In other variations, the optical absorption grating is a two-dimensional array having a plurality of rows and columns, and adjacent columns are staggered relative to one another. Drawings Reference will now be made to the exemplary embodiments illustrated in the drawings. It should be understood that the following description is not intended to limit the disclosure to one included embodiment. On the contrary, the disclosure provided by the present disclosure is intended to cover alternatives, modifications and equivale