Spectacle lens selection method and spectacle lens selection system
AssigneeSeiko Epson Corporation
InventorOsamu Wada
Life of this patent
Estimating the term…
Abstract
An eyeball infraduction value Indih is measured, and then ΔE is determined from an equation ΔE=Indih−(Fh+SPh+Nh) based on the eyeball infraduction value Indih, a distance portion eyepoint height Fh, a progressive corridor length SPh, and a reading portion eyepoint height Nh, and Oh is determined from an equation of Oh=Bh−(Fh+SPh+Nh+ΔE+Uh) based on the ΔE, a lens portion height Bh, the distance portion eyepoint height Fh, the progressive corridor length SPh, the reading portion eyepoint height Nh, and a lower frame height Uh. A spectacle lens that satisfies conditions of 0 mm≦ΔE≦2 mm and 0 mm<Oh is selected.
Claims10
A spectacle lens selection method to select a single spectacle lens including a distance portion, a progressive corridor, and a reading portion from a plurality of target spectacle lens, the method comprising:
- determining a horizontal fixation field width Fw, the Fw extending from a distance eyepoint in a horizontal direction;
- measuring an eyeball infraduction value Indih, the Indih being a length from the distance eyepoint to a reading eyepoint;
- determining a ΔE from Equation (1) based on the Indih, a distance portion eyepoint height Fh from a boundary between the distance portion and the progressive corridor to the distance eyepoint, a progressive corridor length SPh, the SPh being a length from the boundary between the distance portion and the progressive corridor to a boundary between the progressive corridor and the reading portion, and a reading portion eyepoint height Nh from the boundary between the progressive corridor and the reading portion to an optical center of the reading portion;
- determining a th from Equation (2) based on the Fh, the SPh, and the Nh;
- determining an upper frame height Oh from the distance eyepoint to an upper end of a test spectacle lens from Equation (3) based on a lens portion height Bh of the test spectacle lens, the th, the ΔE, and a lower frame height Uh from a lower end of the test spectacle lens to the reading eyepoint,
- ΔE=Indih−(Fh+SPh+Nh) (1)
- th=Fh+SPh+Nh (2)
- Oh=Bh−(th+ΔE+Uh) (3);
- judging a target spectacle lens satisfied the Fw and conditions of 0 mm≦ΔE≦2 mm and 0 mm<Oh;
- and
- selecting a spectacle lens satisfied the Fw and the conditions.
A spectacle lens selection system to select a spectacle lens including a distance portion, a progressive corridor, and a reading portion, the system comprising:
- a horizontal fixation field width determination unit that determines a horizontal fixation field width Fw, the Fw extending from a distance eyepoint of a test spectacle lens in a horizontal direction;
- an eyeball infraduction value measurement unit that measures an eyeball infraduction value Indih, the Indih being a length from the distance eyepoint to a reading eyepoint;
- and
- a selection unit that selects a single spectacle lens from a plurality of types of target spectacle lens based on information containing a value measured by the eyeball infraduction value measurement unit, the selection unit including;
- unit a computation section that determines;
- a ΔE from Equation (1) based on the Indih, a distance portion eyepoint height Fh from a boundary between the distance portion and the progressive corridor to the distance eyepoint, a progressive corridor length SPh, the SPh being a length from the boundary between the distance portion and the progressive corridor to a boundary between the progressive corridor and the reading portion, and a reading portion eyepoint height Nh from the boundary between the progressive corridor and the reading portion to an optical center of the reading portion;
- a th from Equation (2) based on the Fh, the SPh, and Nh;
- and
- an upper frame height Oh from the distance eyepoint to an upper end of a test spectacle lens from Equation (3) based on a lens portion height Bh of the test spectacle lens, the th, the ΔE, and a lower frame height Uh from a lower end of the test spectacle lens to the reading eyepoint,
- ΔE=Indih−(Fh+SPh+Nh) (1)
- th=Fh+SPh+Nh (2)
- Oh=Bh−(th+ΔE+Uh) (3);
- and
- a judgment section that judges a target spectacle lens that satisfies the Fw unit and conditions of 0 mm≦ΔE≦2 mm and 0 mm<Oh, and selects a spectacle lens that satisfied the Fw and the conditions.
Dependencies are inferred from the claim text.