Ocular refractivity measuring apparatus

Claim 2

An ocular refractivity measuring apparatus comprising: a light receiving optical system comprising a light intensity dividing member and an obturating plate having a linear edge so as to obturate part of an opening of said light receiving optical system, wherein said light intensity dividing member is closer to an eye to be measured in an optical path than said obturating plate; an illuminating optical system having a light source member extending so that said light source member extending across the linear edge can be seen from the side of the eye for illuminating the fundus of the eye via said light intensity dividing member; an imaging device provided on a light receiving surface of said light receiving optical system at a position substantially conjugate with a pupil of the eye for receiving the light from said illuminating optical system via the eye for detecting the amount of light in two regions of the pupil of the eye arranged in a direction perpendicular to the linear edge; and calculation means for calculating the refractivity of the eye on the basis of one of the ratio of the amount of light in the two regions of the pupil of the eye arranged in a direction perpendicular to the linear edge detected by said imaging device and a quantity defined as the difference in the amount of light between the two regions divided by the amount of light in the two regions, and on the basis of the distance between the two regions.

Claim 3

An ocular refractivity measuring apparatus according to claim 1, wherein said light source member has the shape of a slit.

Claim 4

An ocular refractivity measuring apparatus according to claim 1, wherein the two regions are point-like regions.

Claim 5

An ocular refractivity measuring apparatus according to claim 1, wherein the two regions are separated from each other or partially overlap each other and wherein the distance between the two regions is the distance between the centers of gravity of the two regions.

Claim 6

An ocular refractivity measuring apparatus according to claim 4, wherein said calculation means calculates the refractivity of the eye in accordance with the ratio of the total amount of light in the two regions.

Claim 7

An ocular refractivity measuring apparatus according to claim 4, wherein said calculation means calculates the refractivity of the eye in accordance with the ratio of the average amount of light in the two regions.

Claim 8

An ocular refractivity measuring apparatus comprising: a focusing light receiving optical system comprising a light intensity dividing member and an obturating plate having a linear edge so as to obturate part of an opening of said focusing light receiving optical system, wherein said light intensity dividing member is closer to an eye to be measured in an optical path than said obturating plate; an illuminating optical system having a light source member extending so that said light source member extending across the linear edge can be seen from the side of the eye for illuminating the fundus of the eye via said light intensity dividing member; an imaging device provided on a light receiving surface of said focusing light receiving optical system at a position substantially conjugate with a pupil of the eye for receiving the light from said illuminating optical system via the eye; magnification detection means for detecting a projection magnification for the pupil of said focusing light receiving optical system; and calculation means for calculating refractivity of the eye using the output from said magnification detection means and on the basis of a distribution of illuminance of a pupillary image imaged on said imaging device.

Claim 9

An ocular refractivity measuring apparatus comprising: a focusing light receiving optical system comprising a light intensity dividing member and an obturating plate having a linear edge so as to obturate part of an opening of said focusing light receiving optical system, wherein said light intensity dividing member is closer to an eye to be measured in an optical path than said obturating plate; an illuminating optical system having a light source member extending so that said light source member extending across the linear edge can be seen from the side of the eye for illuminating the fundus of the eye via said light intensity dividing member; an imaging device provided on a light receiving surface of said focusing light receiving optical system at a position substantially conjugate with a pupil of the eye for receiving the light from said illuminating optical system via the eye; magnification detection means for detecting a projection magnification for the pupil of said focusing light receiving optical system; and calculation means for calculating refractivity of the eye using the output from said magnification detection means and on the basis of a distribution of illuminance of a pupillary image imaged on said imaging device.

Claim 10

An ocular refractivity measuring apparatus for illuminating an eye to be measured and for measuring the refractivity of the eye from a distribution of illuminance of pupillary images imaged on an image medium by light beams obturated by an obturating plate having edges extending in two orthogonal directions at a position deviated from an optical axis and reflected by a fundus of the eye, said apparatus comprising: an imaging optical system for imaging the pupillary image on the image medium via the obturating plate having edges in two orthogonal directions at a position deviated from the optical axis; an illuminating optical system, comprising two light sources for individually illuminating the eye to produce first and second pupillary images imaged by said imaging optical system using said two light sources, wherein said two light sources extend so that one of said two light sources extending across one of the edges of the obturating plate and the other of said two light sources extending across the other of the edges can be seen from the side of the eye in two directions perpendicular to the edges of the obturating plate; a light intensity dividing member positioned closer to the eye than said obturating plate, for directing the light so that light from said illuminating optical system is projected to the eye and imaged by said imaging optical system; and means for calculating an astigmatic angle, the degree of astigmatism, and the degree of spherical ametropia by using the direction of a line segment, connecting two points on and passing through the center of the first pupillary image individually produced by one of said two light sources, along which the first pupillary image has the largest gradient of illuminance, by using the direction of a line segment, connecting two points on and passing through the center of the second pupillary image individually produced by the other of said two light sources, along which the second pupillary image has the largest gradient of illuminance, and by using the distribution of illuminance of the first and second pupillary images along said directions.

Claim 11

An ocular refractivity measuring apparatus for illuminating an eye to be measured and for measuring the refractivity of the eye from a distribution of illuminance of pupillary images imaged on an image medium by light beams obturated by an obturating plate having edges extending in two orthogonal directions at a position deviated from an optical axis and reflected by a fundus of the eye, said apparatus comprising: an imaging optical system for imaging the pupillary image on the image medium via the obturating plate having edges in two orthogonal directions at a position deviated from the optical axis; an illuminating optical system, comprising two light sources for individually illuminating the eye to produce first and second pupillary images imaged by said imaging optical system using said two light sources, wherein said two light sources extend so that one of said two light sources extending across one of the edges of the obturating plate and the other of said two light sources extending across the other of the edges can be seen from the side of the eye in two directions perpendicular to the edges of the obturating plate; a light intensity dividing member positioned closer to the eye than said obturating plate, for directing the light so that light from said illuminating optical system is projected to the eye and imaged by said imaging optical system; and means for calculating an astigmatic angle, the degree of astigmatism, and the degree of spherical ametropia by using the direction of a line segment, connecting two points on and passing through the center of the first pupillary image individually produced by one of said two light sources, along which the first pupillary image has the largest gradient of illuminance, by using the direction of a line segment, connecting two points on and passing through the center of the second pupillary image individually produced by the other of said two light sources, along which the second pupillary image has the largest gradient of illuminance, and by using the distribution of illuminance of the first and second pupillary images along said directions.

Claim 12

An ocular refractivity measuring apparatus for illuminating an eye to be measured and for measuring the ocular refractivity of the eye from a distribution of illuminance on a pupillar image imaged on an image medium by light beams obturated by an obturating plate having edges extending in two orthogonal directions and reflected by a fundus of the eye, said apparatus comprising: an imaging optical system for imaging the pupillary image on the image medium via the obturating plate; an illuminating optical system, comprising two simultaneously lit light sources, for illuminating the eye using said two light sources, wherein said two light sources extend so that one of said two light sources extending across one of the edges of the obturating plate and the other of said two light sources extending across the other of the edges can be seen from the side of the eye; a light intensity dividing member positioned closer to the eye than said obturating plate, for directing light so that light from said illuminating optical system is projected to the eye and imaged by said imaging optical system; and calculation means for calculating the ocular refractivity of the eye in two directions, each perpendicular to a different one of the edges of the obturating plate, by using the distribution of illuminance of the pupillary image on the image medium in two directions, each perpendicular to a different one of the edges of the obturating plate.

Claim 13

An ocular refractivity measuring apparatus for illuminating an eye to be measured and for measuring the ocular refractivity of the eye from a distribution of illuminance on a pupillar image imaged on an image medium by light beams obturated by an obturating plate having edges extending in two orthogonal directions and reflected by a fundus of the eye, said apparatus comprising: an imaging optical system for imaging the pupillary image on the image medium via the obturating plate; an illuminating optical system, comprising two simultaneously lit light sources, for illuminating the eye using said two light sources, wherein said two light sources extend so that one of said two light sources extending across one of the edges of the obturating plate and the other of said two light sources extending across the other of the edges can be seen from the side of the eye; a light intensity dividing member positioned closer to the eye than said obturating plate, for directing light so that light from said illuminating optical system is projected to the eye and imaged by said imaging optical system; and calculation means for calculating the ocular refractivity of the eye in two directions, each perpendicular to a different one of the edges of the obturating plate, by using the distribution of illuminance of the pupillary image on the image medium in two directions, each perpendicular to a different one of the edges of the obturating plate.

Claim 14

An ocular refractivity measuring apparatus comprising: a light receiving optical system comprising a light intensity dividing member and an obturating plate having a linear edge so as to obturate part of an opening of said light receiving optical system, wherein said light dividing member is closer to an eye to be measured in an optical path than said obturating plate; an illuminating optical system, having an optical axis non-coaxial with the optical axis of said light receiving optical system, including a light source member extending so that said light source member extending across the linear edge can be seen from the side of the eye for illuminating the fundus of the eye via said light intensity dividing member; an imaging device provided on a light receiving surface of said light receiving optical system at a position substantially conjugate with a pupil of the eye for receiving the light from said illuminating optical system via the eye for detecting the amount of light in two regions of the pupil of the eye arranged by a predetermined distance in a direction perpendicular to the linear edge of said obturating plate; and calculation means for calculating the refractivity of the eye on the basis of one of the ratio of the amount of light in the two regions of the pupil of the eye arranged in a direction perpendicular to the linear edge of said obturating plate detected by said imaging device and a quantity defined as the difference in the amount of light between the two regions divided by the amount of light in the two regions.

Claim 15

An ocular refractivity measuring apparatus comprising: a light receiving optical system comprising a light intensity dividing member and an obturating plate having a linear edge so as to obturate part of an opening of said light receiving optical system, wherein said light dividing member is closer to an eye to be measured in an optical path than said obturating plate; an illuminating optical system, having an optical axis non-coaxial with the optical axis of said light receiving optical system, including a light source member extending so that said light source member extending across the linear edge can be seen from the side of the eye for illuminating the fundus of the eye via said light intensity dividing member; an imaging device provided on a light receiving surface of said light receiving optical system at a position substantially conjugate with a pupil of the eye for receiving the light from said illuminating optical system via the eye for detecting the amount of light in two regions of the pupil of the eye arranged by a predetermined distance in a direction perpendicular to the linear edge of said obturating plate; and calculation means for calculating the refractivity of the eye on the basis of one of the ratio of the amount of light in the two regions of the pupil of the eye arranged in a direction perpendicular to the linear edge of said obturating plate detected by said imaging device and a quantity defined as the difference in the amount of light between the two regions divided by the amount of light in the two regions.