Patent ID: 8816963

Claim:
An optical navigation module comprising: a light transmission window comprising a navigation surface; a light source located under the transmission window; a first light shield configured for blocking ambient light; a sensor located under the transmission window; a second light shield located between the light source and the sensor and configured for blocking direct light from the light source to the sensor; wherein the light transmission window comprises a first refraction surface on the top of the light source to refract the light and change a direction of the light towards the top navigation surface and a second refraction surface to refract back-scattered light, change a direction of the back-scattered light and guide the back-scattered light from the top navigation surface towards the sensor for sensing relative object movement; wherein the light transmission window further comprises a top navigation surface, a first lens and a second lens; the top navigation surface is the same height as a top surface of the first light shield; the first lens is on the first refraction surface, the first lens transforms the light from the light source to a desirable size; the second lens is on the second refraction surface; two cavities are formed underneath the first light shield and separated by the second light shield; and the sensor and the light source are placed in the two cavities respectively; wherein a top part of the second light shield is inserted into the light transmission window; a top surface of the second light shield is lower than the top surface of the first light shield, and the top surface of the second light shield is higher than a bottom surface of the light transmission window and is higher than a bottom surface of the first light shield; and wherein the first light shield and the second light shield are molded together with the light transmission window.