Method and means for analyzing sphero-cylindrical optical systems

In a lensmeter:

• (a) first and second light detector means, each comprising a light detector having an area capable of detecting the presence of a light beam, for providing position signals indicating which portions of the light detector area are subjected to a light beam;
• (b) means for receiving light from a single source after passage through a test lens and for directing at least two light beams such that each beam is directed at a respectively associated one of said first and second light detection means;
• (c) said light detection means including a means for recognizing when each of said light beams lies on a line extending through the area of its respectively associated light sensor;
• (d) each of said light detector means being capable of recognizing when its respectively associated light beams is directed toward a given region of its area;
• and
• (e) means responsive to said signals for producing relative displacement of said light detector means relative to said light beams toward a position in which said light beams are directed at a given position on their respectively associated light detectors.

In a lens meter:

• (a) first and second light detector means, each comprising a light detector having an area capable of detecting the presence of a light beam, for providing position signals indicating which portions of the light detector area are subjected to a light beam;
• (b) means, including a light source, for directing at least two light beams such that each beam is directed at a respectively associated one of said first and second light detection means;
• (c) said light detection means including a means for recognizing when each of said light beams lies on a line extending through the area of its respectively associated light sensor;
• (d) each of said light detector means being capable of recognizing when its respectively associated light beam is directed toward a given region of its area;
• and
• (e) means, responsive to said signals, for producing relative displacement of said light detector means relative to said light beams toward a position in which said light beams are directed at a given position on their respectively associated light detectors;
• (f) said means for producing relative displacement comprising means for moving both light detectors apart or together in a plane transverse to the direction of said light beam.

In a lensmeter:

• (a) first and second spaced light detection means, each comprising a light detector having areas capable of detecting the presence of a light beam for providing position signals indicating which of said areas of the detector are illuminated by a light beam and for indicating when the beam is directed toward a given portion of said area;
• (b) light beam directing means for directing two light beams emanating from a single source, each at a respectively associated one of said first and second light detection means;
• (c) lens holding means for interposing a test lens between said source and said light beam directing means in the path of the light in both of said light beams such that the direction of said beams is altered as a function of optical properties of the test lens;
• and
• (d) positioning means responsive to said signals for altering the relative position of said light detectors and at least one of said light beam directing means and said lens holding means until the respectively associated light beam of each detector is directed toward said given portion of its area.

In a lensmeter:

• (a) first and second light detection means, each comprising a light detector having an area capable of detecting the presence of a light beam for providing position signals indicating which portions of the detector area are subjected to a light beam and for indicating when the beam is directed toward a given portion of said area;
• (b) light beam directing means for directing two light beams each at a respectively associated one of said first and second light detection means;
• (c) lens holding means for interposing a test lens in the path of the light in both of said light beams such that the direction of said beams is altered as a function of optical properties of the test lens;
• (d) positioning means responsive to said signals for altering the relative position of said light detectors and at least one of said light beam directing means and said lens holding means until the respectively associated light beam of each detector is directed toward said given portion of its area;
• and
• (e) said positioning means comprising means for moving the detectors together in each of two perpendicular directions transverse to the direction of said light beams, and means for moving said detectors such that they move in one direction transverse to the direction of said light beam so that the beams move oppositely relative to their respectively associated light sensors.

In a lensmeter:

• (a) first and second light detector means, each comprising a light detector area capable of detecting the presence of a light beam for providing position signals indicating which portions of the detector area are subjected to a light beam;
• (b) means, including a mask formed with a pair of spaced perforations, for directing two light beams such that each impinges upon a respectively associated one of said first and second light detection means;
• (c) lens holding means for interposing a test lens in the path of the light which forms said two light beams such that the direction of said beams is altered as a function of optical properties of the test lens;
• and
• (d) a focusing lens interposed between said mask and said lens holding means at a position such that the perforations of the mask and a test lens positioned in said lens holding means lie at conjugate distances from said focusing lens whereby the image of the test lens will appear at the position of said perforations.

In a lensmeter:

• (a) first and second light detection means, each comprising a light detector having an area capable of detecting the presence of a light beam for providing signals indicating which portions of the detector area are subjected to the light beam and for indicating when the beam is directed toward a given portion of said area;
• (b) light beam directing means comprising a mask formed with two perforations for directing two light beams each at a respectively associated one of said first and second light detection means;
• (c) a lens holding means for interposing a test lens in the light that forms said light beams such that the direction of said beams is altered as a function of the spherical properties of the test lens;
• (d) said light beam directing means further comprising a focusing lens positioned between said lens holding means and said mask such that a test lens held in said lens holding means and said perforations lie at conjugate distances from said focusing lens whereby an image of the test lens appears at the position of said perforations;
• and
• (e) means for moving said light beams and said light sensors relative to one another such that each light beam impinges upon said given portion of the area of its respectively associated light sensor.

A method of determining the parameters of a test lens with the aid of beam forming apparatus, arranged to form two light beams, and with sensing apparatus capable of sensing the relative spatial position of those two beams, which method comprises the steps of:

• (a) radiating light from a single source through a test lens;
• (b) causing said beam forming apparatus to form two identifiable beams of light from the source after the light has passed through said test lens;
• (c) determining the relative spatial position of said beams in the absence of a test lens with the aid of said sensing apparatus;
• and
• (d) determining the amount of change in the position, one relative to the other two, of the beam forming apparatus, the sensing apparatus, and the test lens which is required to position the beams so that they have the same relative spatial position that they had in the absence of the test lens.

A method of determining parameters of a test lens with the aid of beam forming apparatus for forming two light beams and sensing apparatus capable of sensing the relative spatial position of those two beams, which method comprises the steps of:

• (a) radiating light from a source;
• (b) causing said beam forming apparatus to form two identifiable beams of the light from the source;
• (c) determining the relative spatial position of said beams in the absence of a test lens with the aid of said sensing apparatus;
• (d) interposing a test lens in the path of said two beams;
• (e) determining the amount of change in the position of one relative to the other two of the beam forming apparatus, the sensing apparatus, and the test lens which is required to position the beams so that they have the same relative spatial positions that they had in the absence of the test lens;
• and
• (f) including the further step of causing said beams to pass through a focal point after passing through the test lens and determining the spatial position of the beams after having passed through the focal point;
• (g) said beams being formed such that their paths, in the absence of a test lens, lie symmetrically positioned on opposite sides of a straight line;
• and
• (h) the step of determining being conducted so as to find a change in the spatial positions of said beams relative to said line.