Patent ID: 7242522

Claim:
Binocular magnifying glasses, comprising: a pair of magnifying glasses for right and left eyes, each of said pair of magnifying glasses comprising: a magnifying optical system that has an objective lens with a positive power and an eyepiece with a positive power; and a deflector that deflects an optical path of said magnifying optical system, said deflector located between said objective lens and said eyepiece, wherein said deflector includes a first, second, third and fourth reflective surfaces, light incident on said deflector from said objective lens being reflected by said first, second, third and fourth reflective surfaces in order of said first, second, third and fourth reflective surfaces to direct the incident light to said eyepiece and to form an erect image, wherein when an angle, formed between an intersection line of said second and third reflective surfaces and a plane with which an intersection line of said first and fourth reflective surfaces perpendicularly intersects, is represented by an angle ψ which does not take a value of zero, and where γ-rotation is about each of axes X L and X R , which respectively correspond to visual axes of left and right eyes when an object distance is infinite in a condition of a primary position, and β-rotation is rotation about each of axis Y L and Y R , which are respectively perpendicular to the axes X L and X R and are also perpendicular to a z-axis which perpendicularly intersects with the axis X L at a position of said deflector for the left eye and with the axis X R at a position of said deflector for the right eye, if an angle of the γ-rotation and an angle of the β-rotation are respectively represented by γ(°) and β(°) with respect to a condition in which optical axes of said objective lenses for the right and left eyes are parallel with each other, said binocular magnifying glasses satisfies a relationship: −0.5°<2ψ−{ε(γ)+ε(β)}<0.5° where ε(γ)=γ−cos −1 {1−sin 2 (90−θ)×(1−cos γ)}, ε(β)=cos −1 {1−sin 2 θ×(1−cos β)}, and θ represents a deflection angle (unit: degree) that said deflector deflects the optical path.