Display device with sidelight illumination and luminance correction

1. A display device comprising:

an image display panel;

a planar light source comprising

a light guide plate that irradiates the image display panel from a back surface of the image display panel and includes a first side surface serving as a first incident surface and a second side surface serving as a second incident surface and opposite to the first side surface,

a first sidelight light source that is disposed at a position facing the first incident surface of the light guide plate and includes a plurality of light sources, and

a second sidelight light source that is disposed at a position facing the second incident surface of the light guide plate and includes a plurality of light sources; and

a controller configured to control luminance of the light sources of the first sidelight light source individually and luminance of the light sources of the second sidelight light source individually,

wherein the controller is configured to divide an entire display surface of the image display panel into a first display surface and a second display surface,

wherein the controller is configured to

set first luminance determination blocks by dividing the first display surface into a plurality of portions in a light source array direction in which the light sources of the first and second sidelight light sources are aligned and in a light incident direction orthogonal to the light source array direction,

identify a first highest luminance block having highest luminance out of the first luminance determination blocks present at the same position in the light source array direction in an image to be displayed based on information of an input signal of the image,

identify a first luminance correction target block to be a target of luminance correction out of the first luminance determination blocks present at the same position in the light source array direction based on the first highest luminance block and luminance information on the light sources, and

control light source lighting amounts of the respective light sources so as to satisfy luminance of the identified first luminance correction target block, and

wherein the controller is configured to

set second luminance determination blocks by dividing the second display surface into a plurality of portions in the light source array direction and the light incident direction,

identify a second highest luminance block having highest luminance out of the second luminance determination blocks present at the same position in the light source array direction in the image to be displayed based on information in the input signal of the image,

identify a second luminance correction target block to be a target of luminance correction out of the second luminance determination blocks present at the same position in the light source array direction based on the second highest luminance block and the luminance information on the light sources, and

control the light source lighting amounts of the respective light sources so as to satisfy luminance of the identified second luminance correction target block,

wherein the luminance information on the light sources indicates light intensity distribution of light sources obtained when light sources included in one of the first sidelight light source and the second sidelight light source are turned on individually, and

wherein the controller is configured to perform coordinate transformation so as to obtain luminance information in which the luminance information on the light sources are inverted in a manner line symmetric with respect to a center line of the light guide plate in the light incident direction to use the luminance information on the light sources as light intensity distribution of light sources included in the other of the first sidelight light source and the second sidelight light source.

2. The display device according to claim 1 ,

wherein the controller is configured to

temporarily determine light source drive values of the respective light sources based on the information on the input signal,

correct the temporarily determined light source drive values using the luminance information on the light sources such that the luminance of each of the first and second luminance correction target blocks satisfies target luminance, and

control the light source lighting amounts of the light sources using the respective corrected light source drive values.

3. The display device according to claim 2 ,

wherein the controller is configured to correct the temporarily determined light source drive values in a predetermined order, and

wherein the controller is configured to correct, after correcting at least one of the temporarily determined light source drive values, the remaining ones of the temporarily determined light source drive values using the at least one corrected light source drive value.

4. A display device comprising:

an image display panel;

a planar light source comprising

a light guide plate that irradiates the image display panel from a back surface of the image display panel and includes a first side surface serving as a first incident surface and a second side surface serving as a second incident surface and opposite to the first side surface,

a first sidelight light source that is disposed at a position facing the first incident surface of the light guide plate and includes a plurality of light sources, and

a second sidelight light source that is disposed at a position facing the second incident surface of the light guide plate and includes a plurality of light sources; and

a controller configured to control luminance of the light sources of the first sidelight light source individually and luminance of the light sources of the second sidelight light source individually,

wherein the controller is configured to divide an entire display surface of the image display panel into a first display surface and a second display surface,

wherein the controller is configured to

set first luminance determination blocks by dividing the first display surface into a plurality of portions in a light source array direction I n which the light sources of the first and second sidelight light sources are aligned and in a light incident direction orthogonal to the light source array direction,

identify a first highest luminance block having highest luminance out of the first luminance determination blocks present at the same position in the light source array direction in an image to be displayed based on information of an input signal of the image,

identify a first luminance correction target block to be a target of luminance correction out of the first luminance determination blocks present at the same position in the light source array direction based on the first highest luminance block and luminance information on the light sources, and

control light source lighting amounts of the respective light sources so as to satisfy luminance of the identified first luminance correction target block, and

wherein the controller is configured to

set second luminance determination blocks by dividing the second display surface into a plurality of portions in the light source array direction and the light incident direction,

identify a second highest luminance block having highest luminance out of the second luminance determination blocks present at the same position in the light source array direction in the image to be displayed based on information in the input signal of the image,

identify a second luminance correction target block to be a target of luminance correction out of the second luminance determination blocks present at the same position in the light source array direction based on the second highest luminance block and the luminance information on the light sources, and

control the light source lighting amounts of the respective light sources so as to satisfy luminance of the identified second luminance correction target block,

wherein the luminance information on the light sources indicates light intensity distribution of light sources obtained when light sources included in a first light source group of two light source groups are turned on individually, the two light source group being obtained by dividing light sources included in one of the first sidelight light source and the second sidelight light source into two groups at a first center line of the light guide plate in the light source array direction,

wherein the controller is configured to perform coordinate transformation so as to obtain luminance information in which the luminance information on the light sources are inverted in a manner line-symmetric with respect to the first center line to use the luminance information on the light sources as light intensity distribution of light sources included in a second light source group of the two light source groups,

wherein the controller is configured to perform coordinate transformation so as to obtain luminance information in which the luminance information on the light sources are inverted in a manner line-symmetric with respect to a second center line of the light guide plate in the light incident direction to use the luminance information on the light sources as light intensity distribution of light sources that are present at the same position in the light source array direction as the first light source group and included in the other of the first sidelight light source and the second sidelight light source, and

wherein performs the controller is configured to perform coordinate transformation so as to obtain luminance information in which the luminance information on the light sources are inverted in a manner point-symmetric with respect to a center point at which the first center line intersects with the second center line to use the luminance information on the light sources as light intensity distribution of light sources that are present at the same position in the light source array direction as the second light source group of the two light source groups and included in the other of the first sidelight light source and the second sidelight light source.

5. The display device according to claim 4 , wherein the controller is configured to

temporarily determine light source drive values of the respective light sources based on the information on the input signal,

correct the temporarily determined light source drive values using the luminance information on the light sources such that the luminance of each of the first and second luminance correction target blocks satisfies target luminance, and

control the light source lighting amounts of the light sources using the respective corrected light source drive values.

6. The display device according to claim 5 ,

wherein the controller is configured to correct the temporarily determined light source drive values in a predetermined order, and

wherein the controller is configured to correct, after correcting at least one of the temporarily determined light source drive values, the remaining ones of the temporarily determined light source drive values using the at least one corrected light source drive value.

7. A display device comprising:

an image display panel;

a planar light source comprising

a light guide plate that irradiates the image display panel from a back surface of the image display panel and includes a first side surface serving as a first incident surface and a second side surface serving as a second incident surface and opposite to the first side surface,

a first sidelight light source that is disposed at a position facing the first incident surface of the light guide plate and includes a plurality of light sources, and

a second sidelight light source that is disposed at a position facing the second incident surface of the light guide plate and includes a plurality of light sources; and

a controller configured to control luminance of the light sources of the first sidelight light source individually and luminance of the light sources of the second sidelight light source individually,

wherein the controller is configured to divide an entire display surface of the image display panel into a first display surface and a second display surface, the first display surface being more affected by light output from the first sidelight light source than by light output from the second sidelight light source, the second display surface being more affected by light output from the second sidelight light source than by light output from the first sidelight light source,

wherein the controller is configured to

divide the first display surface into a plurality of first regions corresponding to the light sources included in the first sidelight light source,

set a plurality of first luminance determination blocks for each first region by dividing the first region into a plurality of portions in a light incident direction along which light from the corresponding light source of the first sidelight light source is incident on the first region,

identify a first highest luminance block having highest luminance out of the first luminance determination blocks in each first region in an image to be displayed based on information of an input signal of the image,

identify a first luminance correction target block to be a target of luminance correction out of the first luminance determination blocks in each first region based on the first highest luminance block and luminance information on the light sources, and

control a light source lighting amount of each light source of the first sidelight light source so as to satisfy luminance of the identified first luminance correction target block of the first region corresponding to the light source, and

wherein the controller is configured to

divide the second display surface into a plurality of second regions corresponding to the light sources included in the second sidelight light source,

set a plurality of second luminance determination blocks for each second region by dividing the second region into a plurality of portions in a light incident direction along which light from the corresponding light source of the second sidelight light source is incident on the second region,

identify a second highest luminance block having highest luminance out of the second luminance determination blocks in each second region in the image to be displayed based on information of the input signal of he image,

identify a second luminance correction target block to be a target of luminance correction out of the second luminance determination blocks in each second region based on the second highest luminance block and the luminance information on the light sources, and

control a light source lighting amount of each light source of the second sidelight light source so as to satisfy luminance of the identified second luminance correction target block of the second region corresponding to the light source, using the light source lighting amount of at least one of the light sources of the first sidelight light source, the at least one light source including a light source located directly opposite to the light source corresponding to the second region.

8. The display device according to claim 7 , wherein the controller is configured to

temporarily determine light source drive values of the respective light sources based on the information on the input signal,

correct the temporarily determined light source drive values using the luminance information on the light sources such that the luminance of each of the first and second luminance correction target blocks satisfies target luminance, and

control the light source lighting amounts of the light sources using the respective corrected light source drive values.

9. The display device according to claim 7 ,

wherein the controller is configured to correct the temporarily determined light source drive values in a predetermined order, and

wherein the controller is configured to correct, after correcting at least one of the temporarily determined light source drive values, the remaining ones of the temporarily determined light source drive values using the at least one corrected light source drive value.

10. The display device according to claim 7 ,

wherein the luminance information on the light sources indicates light intensity distribution of light sources obtained when at least a part of the light sources included in the first sidelight light source and the second sidelight light source is turned on individually.

11. The display device according to claim 7 ,

wherein the luminance information on the light sources indicates light intensity distribution of the light sources obtained when the light sources included in the first sidelight light source and the second sidelight light source are turned on individually.