Optical sensing module and fingerprint sensing device

A fingerprint sensing device, configured to sense a fingerprint of a finger and comprising:

• a light emitting element, configured to emit a detection light irradiating the fingerprint;
• and
• an optical sensing module, comprising:
• an image sensor;
• a light transmissive layer, disposed on the image sensor;
• and
• an image selecting layer, disposed on the light transmissive layer,
• wherein when the finger touches a side of the optical sensing module adjacent to the image selecting layer, air in valleys of the fingerprint contacts the optical sensing module, such that the image selecting layer has a first transmittance for the detection light from the valleys, ridges of the fingerprint contact the optical sensing module, such that the image selecting layer has a second transmittance for the detection light from the ridges, the first transmittance is not equal to the second transmittance, such that one of the detection light from the valleys and the detection light from the ridges of the fingerprint is transmitted to the image sensor, and the image selecting layer reflects the other of the detection light from the valleys and the detection light from the ridges of the fingerprint to a direction away from the image sensor.