Image display apparatus, image display method, and non-transitory computer readable medium storing program

1. An image display apparatus, comprising:

a laser light source unit configured to output laser light;

a scan mirror unit configured to reflect and scan the laser light;

at least one processor configured by to execute instructions to:

control the laser light source unit so that a display image corresponding to input display image data is displayed;

control the scan mirror unit so that the display image corresponding to the display image data is displayed,

wherein, in a case in which a predetermined condition is satisfied, set a vertical scan speed, held when a first region in which a content is present in the display image data is scanned in a vertical direction, to a first speed that is lower than a constant speed that is set when a frame scan time required to display one frame is a constant time with the vertical scan speed held constant, and set a vertical scan speed held when a second region in which no content is present in the display image data is scanned in a vertical direction to a second speed that is higher than the constant speed so that the frame scan time is the constant time; and

acquire scan image data in which a length of the first region in the vertical scan direction is increased in accordance with the first speed, in a case in which the predetermined condition is satisfied,

wherein the laser light source unit is controlled so that the display image corresponding to the display image data is displayed with the use of the scan image data.

2. The image display apparatus according to claim 1 , wherein the at least one processor is configured to:

determine a luminance of the first region for the input display image data, and

determine the length by which the first region is increased on the basis of the determined luminance.

3. The image display apparatus according to claim 1 , wherein the predetermined condition is a condition in which the content displayed in the first region is displayed with an increased display luminance.

4. The image display apparatus according to claim 3 , wherein the condition in which the content is displayed with the increased display luminance is that an urgency level of the content displayed in the first region is no lower than a predetermined threshold value.

5. The image display apparatus according to claim 4 , wherein the at least one processor is configured to lower the first speed and raise the second speed as the urgency level of the content displayed in the first region becomes higher.

6. The image display apparatus according to claim 3 , wherein the condition in which the content is displayed with the increased display luminance is that a brightness of surroundings is no lower than a predetermined threshold value.

7. The image display apparatus according to claim 6 , wherein the at least one processor is configured to lower the first speed and raise the second speed as the brightness becomes higher.

8. An image display method, comprising:

acquiring display image data;

in a case in which a predetermined condition is satisfied, performing control so that a display image corresponding to the display image data is displayed with a vertical scan speed, held when a first region in which a content is present in the display image data is scanned in a vertical direction, being set to a first speed that is lower than a constant speed that is set when a frame scan time required to display one frame is a constant time with the vertical scan speed held constant and with a vertical scan speed, held when a second region in which no content is present in the display image data is scanned in a vertical direction, being set to a second speed that is higher than the constant speed so that the frame scan time is the constant time; and

acquire scan image data in which a length of the first region in the vertical scan direction is increased in accordance with the first speed, in a case in which the predetermined condition is satisfied, wherein the control is performed so that the display image corresponding to the display image data is displayed with the use of the scan image data.

9. A non-transitory computer readable medium storing a program causing a computer to execute a method comprising:

acquiring display image data; and

performing control, in a case in which a predetermined condition is satisfied, so that a display image corresponding to the display image data is displayed with a vertical scan speed held when a first region in which a content is present in the display image data is scanned in a vertical direction, being set to a first speed that is lower than a constant speed that is set when a frame scan time required to display one frame is a constant time with the vertical scan speed held constant and with a vertical scan speed, held when a second region in which no content is present in the display image data is scanned in a vertical direction, being set to a second speed that is higher than the constant speed so that the frame scan time is the constant time; and

acquiring scan image data in which a length of the first region in the vertical scan direction is increased in accordance with the first speed, in a case in which the predetermined condition is satisfied, wherein the control is performed so that the display image corresponding to the display image data is displayed with the use of the scan image data.