US 11,980,422 B2
Alignment means of measurement instrument
Mika Salkola, Espoo (FI); Antti Jaatinen, Leppävirta (FI); Kati Stranius, Kuopio (FI); and Mertsi Haapalainen, Kuopio (FI)
Assigned to ICARE FINLAND OY, Vantaa (FI)
Appl. No. 17/166,396
Filed by ICARE FINLAND OY, Vantaa (FI)
PCT Filed Sep. 4, 2019, PCT No. PCT/FI2019/050627
§ 371(c)(1), (2) Date Feb. 3, 2021,
PCT Pub. No. WO2020/053476, PCT Pub. Date Mar. 19, 2020.
Claims priority of application No. 20185754 (FI), filed on Sep. 11, 2018.
Prior Publication US 2021/0298598 A1, Sep. 30, 2021
Int. Cl. A61B 3/16 (2006.01); A61B 3/00 (2006.01); A61B 3/15 (2006.01); G02B 6/42 (2006.01)
CPC A61B 3/165 (2013.01) [A61B 3/0008 (2013.01); A61B 3/152 (2013.01); G02B 6/4226 (2013.01)] 14 Claims
OG exemplary drawing
 
1. An alignment means of a measurement instrument, the alignment means comprising
a housing;
an optical component having a principal axis in a direction parallel to a desired alignment, the optical component being configured such that an eye of the user is to be aligned with the principal axis of the optical component;
a first light source positioned at a first distance S1 from the optical component and at a first height h1 from the principle axis;
a second light source positioned at a second distance S2 from the optical component and at a second height h2 from the principle axis; and
an angle barrier means,
wherein the optical component comprises a focal point, wherein the first and second light sources are positioned between the optical component and the focal point; and
wherein the housing, the optical component, and the angle barrier means are arranged to:
block visibility of the first light source along the principal axis at a distance superior to d1′;
block visibility of the second light source along the principal axis at a distance smaller than d2, wherein d2 is smaller than d1′, and wherein d1′ and d2 are distances from the optical component; and
block visibility of the second light source along the principal axis at a distance superior to d2′, wherein d2′ is greater than d1′;
the alignment means further comprising a third light source arranged at a third distance S3 from the optical component and at a third height h3 from the principal axis, wherein the housing, the optical component, and the angle barrier means are arranged to block visibility of the third light source along the principal axis at a distance smaller than d3, and wherein d3 is greater than d1′ and smaller than d2′.