Lens having an extended range of focus and method of making the same

A method for making a lens with an extended range of focus, the method comprising the steps of:

• (1) calculating a monofocal virtual base system with a basic value of the focal power (Flens) while setting the parameters of a first optical surface, the parameters of a second optical surface and a lens thickness (d1) and also a material type with a refractive index (n2) and an Abbe number;
• (2) dividing the basic value of the focal power (Flens) into a base focal power (Fbase) and into a structure-shaped focal power component (Fstructure), wherein the base focal power (Fbase) is determined by the parameters (R3) of a first optical surface, the parameters (R4) of a calculated surface and a lens thickness (d2) and the material type with a refractive index (n2) and the Abbe number;
• (3) determining the parameters of an additional spiral focal power distribution Fspiral(r, phi) which, in relation to a plane perpendicular to the optical axis, changes as a function of the radial height (r) and of the azimuth angle (phi) of the aperture between a basic value and a maximum value depending nonlinearly on the radius;
• (4) determining an additional spiral and structure-shaped focal power (FSS) by adding the spiral focal power distribution Fspiral from step (3) to the structure-shaped focal power distribution (Fstructure) from step (2);
• (5) adding or subtracting the spiral and structure-shaped focal power distribution
• FSS(r,phi)=Fstructure+Fspiral(r,phi)
• obtained in step (4) to the optical effect of the base system (Fbase) from step (2);
• (6) making the lens with the spiral and structure-shaped focal power distribution at, on and/or inside the lens such that the overall focal power of the manufactured lens emerges as:
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A lens system defining a beam path and having an extended range of focus, the lens system comprising:

• a lens with an extended range of focus arranged as an imaging element in said beam path of said lens system;
• said lens defining an optical axis and being made of a transparent material;
• said lens having two finished optical surfaces;
• said lens having a focal power distribution (Ftot);
• and,
• said focal power distribution (Ftot), referred to a plane perpendicular to said optical axis, changes as a function of the radial height (r) and of the azimuth angle (phi) of the aperture between a calculated basic value of the focal power (Flens) not equal to zero and a maximum value Fspiral max (r, phi) so as to cause said focal power distribution (Ftot) to emerge by calculation as:
• Ftot(r,phi)=Flens(r)+Fspiral max(r,phi)*w(phi)
• wherein Fspiral max(r, phi) depends nonlinearly on the radius and w(phi), which is a factor for the focal power component having the spiral profile, and in that the calculated basic value of said focal power (Flens) is split into a refractive focal power component of a base system (Fbase) and into a focal power component of a structure (Fstructure), furthermore a spiral focal power component
• Fspiral(r,phi)=Fspiral max(r,phi)*w(phi)
• and the focal power component of the structure (Fstructure) being combined to form a spiral and structure-shaped additional focal power
• Fss(r,phi)=FstructureFspiral(r,phi)
• such that the overall focal power of the finished lens emerges as
• Ftot(r,phi)=Fbase+Fss(r,phi).