Catadioptric lens system and video see-through device equipped therewith

A video see-through apparatus comprising:

• a display panel configured to output light of an image;
• and
• a catadioptric lens system comprising:
• a first lens;
• a second lens;
• a third lens;
• and
• a fourth lens,
• wherein the first lens, the second lens, the third lens, and the fourth lens are sequentially disposed in a direction of an optical axis from a side of a user's eye toward a side of an image surface,
• wherein a second surface of the first lens facing the image surface is configured to reflect at least a portion of light from the second lens and a fourth surface of the second lens facing the image surface is configured to re-reflect at least a portion of light reflected from the first lens,
• wherein the first lens has a positive refractive power, the second lens has a positive refractive power, the third lens has a negative refractive power, and the fourth lens has a positive refractive power,
• wherein the first lens is configured to move in the direction of the optical axis within a distance range of 0.1 mm to 1.1 mm from the second lens, and
• wherein a change of refractive power within a movement range of the first lens is within a range of −7D to +1D.