Display device and data processing device

A display device comprising:

• a light guide plate;
• a display panel;
• an intermediate layer;
• and
• an optical element between the light guide plate and a light source,
• wherein the light guide plate comprises a first surface and a second surface,
• wherein the second surface is included in a plane intersecting a plane including the first surface,
• wherein the first surface is configured to be irradiated with light,
• wherein the second surface is configured to distribute the light,
• wherein the second surface is in contact with the intermediate layer,
• wherein the second surface comprises a first refractive index in a region in contact with the intermediate layer,
• wherein the display panel faces the second surface with the intermediate layer positioned therebetween,
• wherein the intermediate layer comprises a region positioned between the second surface and the display panel,
• wherein the intermediate layer comprises a second refractive index in a region in contact with the second surface,
• wherein the second refractive index is smaller than the first refractive index,
• wherein the optical element comprises a first lens including a first curved surface and a second lens including a second curved surface,
• wherein the first curved surface comprises a first curvature radius in a plane including the thickness direction,
• wherein the second curved surface comprises a third curvature radius in a plane including the thickness direction, and
• wherein the first curvature radius is different from the third curvature radius.