Four lens optical lens assembly having specified total Abbe number

An optical lens assembly, configured for a plurality of near infrared light beams emitted by a structured light generating unit having a plurality of light sources to pass through, a side facing the structured light generating unit having the light sources being a light input side, another side opposite thereto being a light output side, the optical lens assembly comprising a first lens element, a second lens element, a third lens element and a fourth lens element arranged along an optical axis in a sequence from the light output side to the light input side, each of the first lens element, the second lens element, the third lens element and the fourth lens element comprising a light output surface facing the light output side and a light input surface facing the light input side;

• wherein
• the first lens element has positive refracting power and the light input side surface of the first lens element has a concave portion in a vicinity of a periphery of the first lens element,
• the light input side surface of the third lens element has a concave portion in a vicinity of the optical axis,
• the light output side surface of the fourth lens element has a concave portion in a vicinity of the optical axis,
• wherein lens elements of the optical lens assembly are only the four lens elements described above and the optical lens assembly satisfies:
• V1+V2+V3+V4≤141, and V1 is an Abbe number of the first lens element, V2 is an Abbe number of the second lens element, V3 is an Abbe number of the third lens element, V4 is an Abbe number of the fourth lens element.

An optical lens assembly, configured for a plurality of near infrared light beams emitted by a structured light generating unit having a plurality of light sources to pass through, a side facing the structured light generating unit having the light sources being a light input side, another side opposite thereto being a light output side, the optical lens assembly comprising a first lens element, a second lens element, a third lens element and a fourth lens element arranged along an optical axis in a sequence from the light output side to the light input side, each of the first lens element, the second lens element, the third lens element and the fourth lens element comprising a light output surface facing the light output side and a light input surface facing the light input side;

• wherein
• the first lens element has positive refracting power and the light input side surface of the first lens element has a concave portion in a vicinity of a periphery of the first lens element,
• the light input side surface of the third lens element has a concave portion in a vicinity of the optical axis,
• the light output side surface of the fourth lens element has a concave portion in a vicinity of a periphery of the fourth lens element,
• wherein lens elements of the optical lens assembly are only the four lens elements described above and the optical lens assembly satisfies:
• V1+V2+V3+V4≤141, and V1 is an Abbe number of the first lens element, V2 is an Abbe number of the second lens element, V3 is an Abbe number of the third lens element, V4 is an Abbe number of the fourth lens element.