Display apparatuses and display methods

1. A display apparatus, comprising:

a display unit, having a plurality of pixels;

a collimation unit configured to collimate light in a light exit direction of the display unit to obtain collimated light; and

an adjustment unit configured to deflect the collimated light, so that light emitted by pixels at different positions in the display unit is imaged at different depths of field,

wherein the plurality of pixels in the display unit are arranged in an array, and light which is emitted by each of the plurality of pixels and is collimated by the collimation unit comprises at least a first part of light and a second part of light; and

wherein the adjustment unit comprises a plurality of adjustment sub-units, a first adjustment sub-unit and a second adjustment sub-unit are provided for the first part of light and the second part of light respectively, so that a first refraction angle for the first part of light is different from a second refraction angle for the second part of light, and

wherein at least one of an incident angle of the first part of light relative to the first adjustment sub-unit, an incident angle of the second part of light relative to the second adjustment sub-unit, a refractive index of the first adjustment sub-unit, and a refractive index of the second adjustment sub-unit is changed such that the first part of light and the second part of light converge at a predetermined depth of field.

2. The display apparatus according to claim 1 , wherein

for one row of pixels of two adjacent rows of pixels of the display unit, the first adjustment sub-unit and the second adjustment sub-unit are provided so that the first part of light and the second part of light converge at a first depth of field; and

for the other row of pixels of the two adjacent rows of pixels of the display unit, the first adjustment sub-unit and the second adjustment sub-unit are provided so that the first part of light and the second part of light converge at a second depth of field different from the first depth of field.

3. The display apparatus according to claim 2 , wherein the first adjustment sub-unit and the second adjustment sub-unit are provided so that the first part of light which is emitted by the one row of pixels and is collimated by the collimation unit and the second part of light which is emitted by the other row of pixels and is collimated by the collimation unit converge at a third depth of field which is between the first depth of field and the second depth of field.

4. The display apparatus according to claim 3 , wherein the first adjustment sub-unit and the second adjustment sub-unit are provided so that the second part of light which is emitted by the one row of pixels and is collimated by the collimation unit and the first part of light which is emitted by the other row of pixels and is collimated by the collimation unit are totally reflected.

5. The display apparatus according to claim 2 , wherein one of the first depth of field and the second depth of field is in a range of 0.20 meters to 0.30 meters in a direction opposite to the light exit direction of the display unit and the other of the first depth of field and the second depth of field is in a range of 3 meters to 5 meters in the direction opposite to the light exit direction of the display unit.

6. A display method for a display apparatus which comprises a display unit having a plurality of pixels; a collimation unit configured to collimate light in a light exit direction of the display unit to obtain collimated light; and an adjustment unit configured to deflect the collimated light so that light emitted by pixels at different positions in the display unit is imaged at different depths of field, the display method comprising:

in a first time period, displaying a first frame of image at one row of pixels of pixels of the display unit, the first frame of image being deflected by the adjustment unit so that the first frame of image is imaged at a first depth of field; and

in a second time period, displaying a second frame of image different from the first frame of image at another row of pixels of the display unit which is adjacent to the one row of pixels, the second frame of image being deflected by the adjustment unit so that the second frame of image is imaged at a second depth of field different from the first depth of field,

wherein the plurality of pixels in the display unit are arranged in an array, and light which is emitted by each of the plurality of pixels and is collimated by the collimation unit comprises at least a first part of light and a second part of light; and

wherein the adjustment unit comprises a plurality of adjustment sub-units, a first adjustment sub-unit and a second adjustment sub-unit are provided for the first part of light and the second part of light respectively, so that a first refraction angle for the first part of light is different from a second refraction angle for the second part of light, and

wherein at least one of an incident angle of the first part of light relative to the first adjustment sub-unit, an incident angle of the second part of light relative to the second adjustment sub-unit, a refractive index of the first adjustment sub-unit, and a refractive index of the second adjustment sub-unit is changed such that the first part of light and the second part of light converge at a predetermined depth of field.

7. The display method according to claim 6 , wherein the first frame of image comprises a foreground image, and the second frame of image comprises a background image.

8. The display method according to claim 6 , further comprising:

in a third time period, displaying at least a third frame of image on the display unit, the third frame of image being deflected by the adjustment unit so that the third frame of image is imaged at a third depth of field which is between the first depth of field and the second depth of field.