Patent ID: 7085219

Claim:
An optical lens for condensing a light emitted from a laser light source on an optical recording medium, the light having at least one kind of a wavelength λ 1 within a wavelength range from 400 nm to 440 nm, the optical lens being mounted in an optical information recording and reproducing apparatus capable of executing at least either a record of information on the optical recording medium or a reproduction of information recorded on the optical recording medium by condensing the light on the optical recording medium, the optical lens comprising: a light incident side lens surface disposed on a side which the light emitted from the laser light source enters, the light incident side lens surface comprising a peripheral part having an angle θ of 45 degrees or more, where the θ is an angle formed by a normal line at a position on each lens surface and an optical axis; and a first anti-reflection film formed on the light incident side lens surface, the first anti-reflection film having a film thickness which is set so that a wavelength λ 2 at which a reflectance of the light entering a central part of the light incident side lens surface at an angle of zero degrees has a local minimum value, satisfies λ 1 <λ 2 and 420 nm≦λ 2 680 nm, the central part having the angle θ of zero degrees.