Planar illumination device
View Patent ↗A planar illumination device includes: a light guide plate; a point light source disposed to face a light incident surface of the light guide plate; and a circuit substrate on which the point light source is mounted. The circuit substrate includes: a base film; a first conductive layer and a first coverlay film stacked in sequence on a first surface of the base film, the first conductive layer including a pair of lands to which a pair of electrode terminals of the point light source are electrically connected; and a second conductive layer and a second coverlay film stacked in sequence on a second surface of the base film the second coverlay film including a light absorber. The second coverlay film is exposed between the lands and in front of a light emitting surface of the point light source in a light emitting direction.
1. A planar illumination device comprising:
a light guide plate including a pair of principal surfaces opposed to each other, one of the principal surfaces serving as a light emitting surface;
a point light source disposed to face a light incident surface of the light guide plate; and
a circuit substrate on which the point light source is mounted, the circuit substrate comprising:
a base film including a first surface and a second surface;
a first conductive layer and a first coverlay film stacked in sequence on the first surface of the base film, the first conductive layer including a pair of lands to which a pair of electrode terminals of the point light source are electrically connected; and
a second conductive layer and a second coverlay film stacked in sequence on the second surface of the base film the second coverlay film including a light absorber,
wherein the second coverlay film is exposed between the lands and in front of a light emitting surface of the point light source in a light emitting direction in a plan view of the circuit substrate as viewed from the first surface of the base film.
2. The planar illumination device according to claim 1 , wherein
the point light source includes a light emitting chip and a phosphor, and
the light absorber absorbs at least light emitted by the phosphor.
3. The planar illumination device according to claim 2 , wherein the second coverlay film includes a black member.
4. The planar illumination device according to claim 2 , wherein the second coverlay film includes a blue member.
5. The planar illumination device according to claim 1 , wherein the second coverlay film includes a black member.
6. The planar illumination device according to claim 1 , wherein the second coverlay film includes a blue member.
7. The planar illumination device according to claim 1 , wherein a front portion of the second coverlay film in the emitting direction of light from the point light source overlaps the principal surfaces of the light guide plate in a plan view of the circuit substrate.
8. The planar illumination device according to claim 1 , wherein the base film includes:
a front side surface substantially aligned with the light emitting surface of the point light source in the plan view of the circuit substrate; and
a cutout formed at a position overlapping the point light source and extending toward a rear from the front side surface.