Bio sensing device
Disclosed is a bio sensing device including a medium layer, a light emitting element and an optical sensor. The light emitting element is configured to emit a light toward a user's skin layer, in which the light passes through the medium layer and has a maximum intensity in a first wavelength. The optical sensor is configured to receive a reflected part of the light from the user's skin layer, in which the reflected part of the light passes through the medium layer, and the medium layer has a first transmittance greater than 60% with respect to the first wavelength.
1 . A bio sensing device, comprising:
a medium layer;
a light emitting element configured to emit a light toward a user's skin layer, wherein the light passes through the medium layer and has a maximum intensity in a first wavelength;
an optical sensor configured to receive a reflected part of the light from the user's skin layer, wherein the reflected part of the light passes through the medium layer, and the light emitting element is not overlapped with the optical sensor in a normal direction of the medium layer; and
a first transistor directly connected to the light emitting element, wherein a gate electrode of the first transistor is not overlapped with the light emitting element in the normal direction,
wherein the medium layer has a first transmittance greater than 60% with respect to the first wavelength.
2 . The bio sensing device according to claim 1 , wherein the first transmittance is greater than 80%.
3 . The bio sensing device according to claim 1 , wherein the optical sensor has a maximum responsivity in a second wavelength, and the medium layer has a second transmittance greater than 60% with respect to the second wavelength.
4 . The bio sensing device according to claim 3 , wherein the second transmittance is greater than 80%.
5 . The bio sensing device according to claim 1 , further comprising a second transistor directly connected to the optical sensor, wherein a gate electrode of the second transistor is not overlapped with the optical sensor in the normal direction.
6 . The bio sensing device according to claim 1 , wherein a distance between the optical sensor and the medium layer is less than a distance between the light emitting element and the medium layer.
7 . The bio sensing device according to claim 1 , wherein a distance between the light emitting element and the medium layer is less than a distance between the gate electrode of the first transistor and the medium layer.
8 . The bio sensing device according to claim 1 , further comprising a second transistor directly connected to the optical sensor, wherein a distance between the optical sensor and the medium layer is less than a distance between a gate electrode of the second transistor and the medium layer.
9 . The bio sensing device according to claim 1 , wherein the medium layer is a stretchable medium layer.
10 . The bio sensing device according to claim 9 , wherein the medium layer comprises a plurality of island portions and a bridge portion connecting at least two of the plurality of island portions, and the light emitting element and the optical sensor are disposed on at least one of the plurality of island portions.
11 . The bio sensing device according to claim 9 , further comprising a supporting layer disposed under the medium layer, wherein the supporting layer comprises an opening overlapping at least one of the light emitting element and the optical sensor in the normal direction of the medium layer.
12 . The bio sensing device according to claim 1 , wherein the optical sensor comprises a plurality of photodiodes stacked with one another.
13 . The bio sensing device according to claim 12 , wherein the plurality of photodiodes are organic photodiodes.
14 . The bio sensing device according to claim 1 , wherein the light emitting element and the optical sensor are disposed on the medium layer.
15 . The bio sensing device according to claim 1 , further comprising a base layer, wherein the light emitting element and the optical sensor are disposed on the base layer and between the base layer and the medium layer.
16 . The bio sensing device according to claim 15 , wherein the base layer is a stretchable base layer.
17 . The bio sensing device according to claim 16 , wherein the base layer comprises a plurality of island portions and a bridge portion connecting at least two of the plurality of island portions, and the light emitting element and the optical sensor are disposed on at least one of the plurality of island portions.
18 . The bio sensing device according to claim 16 , further comprising a supporting layer disposed on a side of the base layer opposite to another side of the base layer on which the light emitting element is disposed.