OPTICAL SYSTEM

• Main Author: SHIODA RYO
• Format: Patent
• Language: English; Japanese
• Published: 01.02.2024
• Subjects: OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICS; PHYSICS

To provide an optical system that reduces variations in image magnification while correcting various aberrations during image formation by appropriately distributing refractive powers.SOLUTION: An optical system includes, in order from the object side, a first lens group G1 having positive refractive power and a second lens group G2 having positive refractive power. When adjusting focus from a long distance to a short distance, at least the second lens group G2 moves to the object side. The second lens group G2 includes, in order from the object side, a front subgroup G2A and a rear subgroup G2B of the second lens group G2. The front subgroup G2A and the rear subgroup G2B of the second lens group G2 each include at least one lens with positive refractive power and at least one lens with negative refractive power, satisfying predetermined conditional expressions.SELECTED DRAWING: Figure 1 【課題】屈折力を適切に配置することで、結像時の諸収差を補正した上で像倍率変動を抑制した光学系を提供する。【解決手段】物体側から順に、正の屈折力を有する第１レンズ群Ｇ１と、正の屈折力を有する第２レンズ群Ｇ２を有し、遠距離から近距離への合焦に際し少なくとも第２レンズ群Ｇ２が物体側に移動し、第２レンズ群Ｇ２は物体側から順に第２レンズ群前群Ｇ２Ａと第２レンズ群後群Ｇ２Ｂで構成され、第２レンズ群前群Ｇ２Ａと第２レンズ群後群Ｇ２Ｂはそれぞれ正の屈折力のレンズと負の屈折力のレンズを１枚以上有し、所定の条件式を満足する。【選択図】図１