Anti-reflective layer, touch substrate, touch panel, and portable electronic apparatus

1. A portable electronic apparatus, comprising:

a display panel;

a touch substrate attached to the display panel; and

an image capturing device comprising a lens mounted in a window region configured to allow the lens to receive light, the display panel and the touch substrate being completely absent in the window region;

wherein the portable electronic apparatus in the window region comprises:

a base substrate;

a first sub-layer on the base substrate;

a second sub-layer on a side of the first sub-layer away from the base substrate;

a third sub-layer on a side of the second sub-layer away from the first sub-layer; and

the lens on a side of the third sub-layer away from the second sub-layer;

wherein the first sub-layer, the second sub-layer, and the third sub-layer are laminated together;

the second sub-layer is in contact with the first sub-layer, and is in contact with the third sub-layer;

the second sub-layer has a refractive index greater than those of the first sub-layer and the third sub-layer; and

a thickness of the second sub-layer is in a range of 50 nm to 75 nm.

2. The portable electronic apparatus of claim 1 , wherein the first sub-layer and the third sub-layer are made of a same material; and

the second sub-layer is made of a material different from that of the first sub-layer and the third sub-layer.

3. The portable electronic apparatus of claim 1 , wherein the first sub-layer and the third sub-layer are made of silicon dioxide; and

the second sub-layer is made of a material comprising SiO x N y , wherein x>0, and y>0.

4. The portable electronic apparatus of claim 1 , wherein a light transmissive rate of the anti-reflective layer is greater than 95% at a wavelength of approximately 550 nm.

5. The portable electronic apparatus of claim 1 , wherein the refractive index of the second sub-layer is in a range of approximately 1.46 to approximately 2.0.

6. The portable electronic apparatus of claim 1 , wherein the first sub-layer has a thickness in a range of approximately 10 nm to approximately 20 nm; and

the third sub-layer has a thickness in a range of approximately 90 nm to approximately 110 nm.

7. The portable electronic apparatus of claim 1 , wherein the display panel is absent in the window region.

8. The portable electronic apparatus of claim 1 , wherein a touch electrode layer is absent in the window region.

9. The portable electronic apparatus of claim 1 , wherein the lens is directly adjacent to the third sub-layer.

10. The portable electronic apparatus of claim 1 , wherein an average visible light reflective rate of the anti-reflective layer is no more than 1.5%.

11. The portable electronic apparatus of claim 1 , wherein an average visible light transmissive rate of the anti-reflective layer is greater than 92%.

12. The portable electronic apparatus of claim 1 , wherein the lens is completely within the window region.

13. The portable electronic apparatus of claim 1 , wherein the anti-reflective layer extends from a display area of the display panel into the window region.

14. The portable electronic apparatus of claim 1 , wherein the window region is in a peripheral region of the display panel.