Light emitting device, surface light source device, and display device

1 . A light emitting device comprising a light emitting element and a light flux controlling member for controlling light from the light emitting element, wherein

the light flux controlling member includes

an incidence surface for allowing incidence of the light from the light emitting element, the incidence surface being disposed to face a light emitting surface of the light emitting element,

a total reflecting surface for totally reflecting, in a direction away from an optical axis of the light emitting element, the light incident on the incidence surface, and

an emission surface for emitting the light reflected by the total reflecting surface, and

in a light distribution curve indicating a far-field light distribution of the light emitting device,

when an angle of a direction along the optical axis is 0°, an integral value of a luminous intensity in a range of 0° to 180° is A, and an integral value of a luminous intensity in a range of 83° to 97° is a1, a1/A is from 0.23 to 0.38.

2 . The light emitting device according to claim 1 , wherein, in the light distribution curve, when an integral value of a luminous intensity in a range of 0° to 80° is a2, a2/A is 0.60 or less.

3 . The light emitting device according to claim 1 , wherein, in the light distribution curve, when an integral value of a luminous intensity in a range of 110° to 180° is a3, a3/A is 0.40 or less.

4 . The light emitting device according to claim 1 , wherein

at least a portion of light emitted at an angle of 30° to 50° with respect to the optical axis from a light emitting center of the light emitting element is reflected by the total reflecting surface so that an angle of the reflected portion with respect to the optical axis is 90° or more.

5 . A surface light source device, comprising:

a substrate;

a plurality of light emitting devices disposed on the substrate; and

a light diffusion plate for diffusing light from the plurality of light emitting devices,

wherein

the plurality of light emitting devices include the light emitting device according to claim 1 .

6 . The surface light source device according to claim 5 , wherein

when a distance between the substrate and the light diffusion plate is H, and a center-to-center distance between adjacent light emitting devices among the plurality of light emitting devices is P, H is more than 7 mm, and H/P is 0.15 to 0.25.

7 . A display device comprising the surface light source device according to claim 5 .