US 5,844,671 A · Lens meter

Abstract

A lens meter having a measuring optical system comprises a device for measuring an optical characteristics continuously, a device for introducing the lens to the desired positional relation for a measuring optical axis in the measuring optical system on the basis of the measured data, a device for generating the alignment ending signal when the alignment is achieved to the predetermined standard level, a device for judging whether the measured data is stable within a predetermined permissible range of the variation, and a device for storing the measured data of the lens based on the judgment result. This apparatus further comprises a device for designating which the left or right lens should be measured, a device for generating the signal for reading-and-storing the measured data, a device for storing the measurement result, a device for detecting whether the lens exists on the measuring optical axis, and a device for judging the changing-over of the left or right of the lens. This apparatus further comprises a device for changing-over a mode to measure an additive diopter in the progressive multi focus lens, a device for inputting which the lens is for left or right, a device for detecting a displacement of a measuring position, a device for conducting to a right and left reference axis of the lens, a device for conducting a measuring position closed to the near viewing section from the far viewing section, and a device for displacing the measuring position closed to the near viewing section to the predetermined nose position.

Claims10

Dependent claims

A lens meter having a measuring optical system for projecting a measuring light flux on a lens to be examined and detecting a position of an image formed on a light receiving element by the measuring light flux transmitted through the examined lens, calculating means for calculating a refractive power of the lens on the basis of a measurement result from said measuring optical system, and control means for controlling an operation of an apparatus, the lens meter comprising:

mode changing-over means for changing-over a measuring mode to each of a progressive multifocus lens measuring mode and a single focus lens measuring mode;
alignment means for moving the lens to a desired position with respect to a measuring optical axis of said measuring optical system on the basis of a prism degree obtained by operation of said measuring optical system and said calculating means;
judging means for judging whether the prism degree is within predetermined limits and that the refractive power is stable within predetermined limits of variation;
store signal generating means for generating a signal for storing the refractive power as the refractive power of the lens when said judging means judges the prism degree is within the predetermined limits and that the refractive power is stable within the predetermined limits of variation;
and
memory means for storing the refractive power when said store signal generating means generates a store signal as the refractive power of the lens.

3 more elements

mode changing-over means for changing-over a measuring mode to each of a progressive multifocus lens measuring mode and a single focus lens measuring mode;
judging means for judging whether a prism degree obtained by operation of said measuring optical system and said calculating means is within predetermined limits and that the refractive power is stable within predetermined limits of variation, said judging means having alignment means for moving the lens to a desired position with respect to a measuring optical axis in said measuring optical system, said alignment means comprising:
first conduction means for conducting the lens to the desired position with respect to the measuring optical axis in said measuring optical system based on the prism degree when the measuring mode is changed-over to said single focus lens measuring mode, and for conducting a measuring position to a reference ordinate line of the lens based on the prism degree when the measuring mode is changed-over to said progressive multifocus lens measuring mode;
and
second conduction means for conducting the measuring position close to a near viewing section through a progressive section from a far viewing section based on a measured astigmatism refractive power;
store signal generating means for generating a signal for storing the refractive power as the refractive power of the lens when said judging means judges that the prism degree is stable within predetermined limits and that the refractive power is within predetermined limits of variation;
and
memory means for storing the refractive power when said store signal generating means generates a store signal as the refractive power of the lens.

5 more elements

mode changing-over means for changing-over a measuring mode to each of a progressive multifocus lens measuring mode and a single focus lens measuring mode;
detecting means for detecting a displacement in a lateral direction of the lens;
store signal generating means for generating a signal for storing the refractive power as the refractive power of the lens, said store signal generating means having alignment means for moving the lens to a desired position with respect to a measuring optical axis in said measuring optical system, said alignment means comprising:
first conduction means for conducting the lens to the desired position with respect to the measuring optical axis in said measuring optical system based on a prism degree, obtained by operation of said measuring optical system and said calculating means when the measuring mode is changed-over to said single focus lens measuring mode, and for conducting a measuring position to a reference ordinate line of the lens based on the prism degree, when the measuring mode is changed-over to said progressive multifocus lens measuring mode;
second conduction means for conducting the measuring position close to a near viewing section through a progressive section from a far viewing section based on a measured astigmatism refractive power;
and
third conduction means for conducting the measuring position to a predetermined nose side based on a detecting result by said detecting means;
and
memory means for storing the refractive power when said store signal generating means generates a store signal as the refractive power of the lens.

6 more elements

Dependencies are inferred from the claim text.

Lens meter

Life of this patent

Lens meter

Life of this patent

Abstract

Claims10