Display panel and display apparatus having a photochromic layer

1. A display panel having a subpixel region and an inter-subpixel region, comprising:

a base substrate; and

a photochromic layer on the base substrate at least partially in the subpixel region for preventing light leakage in the subpixel region;

wherein the photochromic layer comprises a plurality of photochromic blocks;

the display panel has a spacer region configured to receive a spacer for maintaining a gap between a first display substrate and a second display substrate facing the first display substrate;

the spacer region is in a light leakage preventing region; and

one of the plurality of photochromic blocks is in the light leakage preventing region.

2. The display panel of claim 1 , wherein a projection of the spacer region on the base substrate is completely within a projection of the one of the plurality of photochromic blocks on the base substrate.

3. The display panel of claim 1 , wherein the projection of the one of the plurality of photochromic blocks on the base substrate surrounds and abuts a perimeter of the projection of the spacer region on the base substrate.

4. The display panel of claim 1 , further comprising a black matrix;

wherein a projection of the spacer region on the base substrate overlaps with that of the black matrix;

the light leakage preventing region includes a sub-region corresponding to a portion of the black matrix.

5. The display panel of claim 4 , wherein the sub-region corresponding to the portion of the black matrix overlaps with a sub-region of the light leakage preventing region corresponding to the one of the plurality of photochromic blocks.

6. The display panel of claim 4 , wherein the sub-region corresponding to the one of the plurality of photochromic blocks abuts two sides of the sub-region corresponding to the portion of the black matrix.

7. The display panel of claim 1 , wherein the photochromic layer is configured to transition from a first state to a second state when exposed to a light intensity exceeding an intensity threshold; and

the photochromic layer has a first light transmittance rate in the first state higher than a second light transmittance rate in the second state.

8. The display panel of claim 7 , wherein the first state is a visible light transmissive state, and the second state is a visible light blocking state.

9. A display panel of claim 8 ,

wherein the photochromic layer is configured to transition from the second state to the first state when the photochromic layer is no longer exposed to the light intensity exceeding the intensity threshold.

10. The display panel of claim 1 , wherein the light leakage preventing region has a substantially the same external contour as the spacer region.

11. The display panel of claim 1 , wherein the light leakage preventing region is concentric with the spacer region.

12. The display panel of claim 1 , wherein the light leakage preventing region has a diameter or width greater than that of the spacer region by an amount in a range of approximately 2 μm to approximately 200 μm.

13. The display panel of claim 1 , wherein the photochromic layer comprises silver halide.

14. The display panel of claim 13 , wherein the photochromic layer further comprises a catalyst.

15. The display panel of claim 1 , wherein the photochromic layer has a thickness in a range of approximately 0.1 μm to approximately 1 μm.

16. The display panel of claim 1 , further comprising:

an alignment film on a side of the photochromic layer distal to the base substrate for aligning liquid crystal molecules;

wherein a projection of the photochromic layer on the base substrate at least partially overlaps with that of the alignment film; and

the photochromic layer is configured to prevent light leakage due to a damage on the alignment film.

17. The display panel of claim 1 , further comprising a color filter on a side of the photochromic layer proximal to the base substrate.

18. The display panel of claim 1 , wherein the photochromic layer is an integral layer covering at least the subpixel region.

19. A display apparatus, comprising a display panel of claim 1 .