PROJECTION LENS OPTICAL SYSTEM, PROJECTION DEVICE EMPLOYING THE SAME, AND WEARABLE DEVICE

Provided are a projection lens optical system, and a projection device and a wearable device including the projection device. The projection lens optical system is used in a projection device of a wearable device and includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens, sequentially arranged from an emission area to an image plane, wherein the first lens has a positive refractive power, the second lens has a negative refractive power, the third lens has a positive refractive power, the fourth lens has a negative refractive power, the fifth lens has a negative refractive power, and the sixth lens has a positive refractive power, wherein the projection lens optical system satisfy the following Conditional Expression:LB/f≤0.5.