Binocular multiplexing method and device

1. A binocular multiplexing device ( 100 ) for an ophthalmological instrument ( 110 ) having a single channel for objective measurement of at least one visual parameter of a subject, said ophthalmological instrument comprising means for generating a single illuminating beam ( 15 ), means for collecting a measuring beam ( 55 ) generated by reflection and/or refraction of said illuminating beam from an eye of the subject, and a sensor associated with said single measuring channel, said binocular multiplexing device comprising:

first optical splitting means ( 4 , 25 ) able to receive a stimulating image beam ( 14 ) issued from a stimulus test pattern and intended to stimulate accommodation by the subject, said first optical splitting means ( 4 , 25 ) being able to split said stimulating image beam ( 14 ) into a right ocular stimulating beam ( 14 a ) and a left ocular stimulating beam ( 14 a ) so as to stimulate accommodation by the right eye ( 13 ) and left eye ( 12 ) of the subject simultaneously;

second optical splitting means ( 5 , 140 , 24 , 43 , 44 , 45 , 46 ) able to receive said single illuminating beam ( 15 ) and to split said single illuminating beam ( 15 ) into a right monocular illuminating beam ( 15 b ) and a left monocular illuminating beam ( 15 a ), said right monocular illuminating beam ( 15 b ) and left monocular illuminating beam ( 15 a ) being intended to illuminate the right eye ( 13 ) and the left eye ( 12 ) of the subject, respectively, in order to form, after reflection and/or refraction from the eye ( 12 , 13 ) in question, a right ocular measuring beam ( 55 b ) and a left ocular measuring beam ( 55 a ), respectively;

optical switching means ( 5 , 24 , 43 , 44 , 45 , 46 ) able to receive said right ocular measuring beam ( 55 b ) and said left ocular measuring beam ( 55 a ) and to steer in sequence said right ocular measuring beam ( 55 b ) and said left ocular measuring beam ( 55 a ) into said single measuring channel, respectively;

first optical combining means ( 7 , 29 ) able to superpose the right ocular stimulating beam ( 14 b ) and the right monocular illuminating beam ( 15 b ), and first optical means for directing the right ocular stimulating beam ( 14 b ) and the right monocular illuminating beam ( 15 b ) toward the right eye ( 13 ); and

second optical combining means ( 6 , 28 ) able to superpose the left ocular stimulating beam ( 14 a ) and the left monocular illuminating beam ( 15 a ), and second optical means for directing the left ocular stimulating beam ( 14 a ) and the left monocular illuminating beam ( 15 a ) toward the left eye ( 12 ).

2. The binocular multiplexing device ( 100 ) as claimed in claim 1 , in which said first optical splitting means ( 4 , 25 ) comprise a beam-splitting plate or a beam-splitting cube.

3. The binocular multiplexing device ( 100 ) as claimed in claim 2 , comprising an electronic processing unit suitable for receiving a signal representative of the switching state of said optical switching means ( 5 , 24 , 43 , 44 , 45 ) and to receive, in sequence, a first measurement representative of said right ocular measuring beam ( 55 b ) and a second measurement representative of said left ocular measuring beam ( 55 a ), said electronic processing unit being able to combine said signal representative of the switching state and said first and second measurements in order to deliver a multiplexed binocular measurement of at least one vision parameter.

4. The binocular multiplexing device ( 100 ) as claimed in claim 1 , in which said optical switching means ( 5 , 24 , 43 , 44 , 45 ) comprise a dichroic plate, an orientable mirror ( 24 ), a retractable mirror, an electro-optical modulator, an acousto-optical modulator and/or polarization-selecting means ( 43 , 44 , 45 , 46 ).

5. The binocular multiplexing device ( 100 ) as claimed in claim 1 , in which said second optical splitting means are merged with said optical switching means, or in which said second optical splitting means comprise a beam-splitting plate or a beam-splitting cube.

6. The binocular multiplexing device ( 100 ) as claimed in claim 1 , in which said first optical combining means comprise a dichroic plate ( 7 , 29 ) able to superpose a right ocular stimulating beam ( 14 b ) in the visible domain and a right monocular illuminating beam ( 15 b ) in the infrared domain, and/or said second optical combining means comprise a dichroic plate ( 6 , 28 ) able to superpose a left ocular stimulating beam ( 14 a ) in the visible domain and a left monocular illuminating beam ( 15 a ) in the infrared domain, respectively.

7. The binocular multiplexing device ( 100 ) as claimed in claim 1 , furthermore comprising an optical port ( 22 , 35 ) for coupling to an ophthalmological instrument ( 110 ) having a single measuring channel, said optical coupling port ( 22 , 35 ) being able to receive a stimulating image beam ( 14 ) issued from a stimulus test pattern, and a single illuminating beam ( 15 ), and to transmit a single measuring beam ( 55 ), and mechanical and/or opto-mechanical means for aligning said ophthalmological instrument ( 110 ) having a single measuring channel and said binocular multiplexing device ( 100 ), said mechanical and/or opto-mechanical aligning means comprising an alignment test pattern ( 48 , 50 ) able to emit an optical aligning beam, and optical means ( 47 , 51 , 52 ) able to superpose said aligning optical beam ( 60 ) and said single measuring beam ( 55 ) in the optical coupling port ( 22 , 35 ).

8. An ophthalmological instrument ( 120 ) for multiplexed binocular measurement of at least one vision parameter of a subject, said ophthalmological instrument comprising a binocular multiplexing device ( 100 ) according to claim 7 , and:

ophthalmological means ( 2 ) for measuring at least one vision parameter of a subject, said ophthalmological measuring means being able to generate a single illuminating beam ( 15 ) and to receive and analyze a single measuring beam ( 55 ) generated by reflection and/or refraction of said single illuminating beam from an eye ( 12 , 13 ) of the subject, said single illuminating beam ( 15 ) and said single measuring beam ( 55 ) following reciprocal optical paths between said ophthalmological measuring means ( 2 ) and the eye ( 12 , 13 ) of the subject.

9. The binocular multiplexing device ( 100 ) as claimed in claim 1 , comprising a right exit pupil ( 37 ), a left exit pupil ( 36 ) and imaging optical means ( 20 , 21 , 23 , 32 , 33 , 34 ), said right exit pupil ( 37 ) being able to receive said right monocular illuminating beam ( 15 b ) and said right ocular measuring beam ( 55 b ), and said left exit pupil ( 36 ) being able to receive said left monocular illuminating beam ( 15 a ) and said left ocular measuring beam ( 55 a ), respectively, and said imaging optical means ( 18 , 19 , 20 , 21 , 23 , 32 , 33 , 34 ) being able to form the image of an exit pupil ( 22 , 35 ) of said ophthalmological instrument ( 100 ) having a single measuring channel on said right exit pupil ( 37 ) and/or said left exit pupil ( 36 ).

10. The binocular multiplexing device ( 100 ) as claimed in claim 9 , comprising secondary illuminating means ( 160 , 161 ) able to emit a secondary illuminating beam ( 170 , 171 ) in the direction of the cornea of each eye ( 12 , 13 ) so as to generate a right ocular measuring beam ( 55 b ) and a left ocular measuring beam ( 55 a ), respectively, in order to provide an analysis of the cornea by keratometry and/or corneal topography.

11. The binocular multiplexing device ( 100 ) as claimed in claim 9 , comprising:

a right optical system ( 9 , 11 , 21 ) placed between the first optical combining means ( 7 , 29 ) and the right eye ( 13 ) of the subject;

a left optical system ( 8 , 10 , 20 ) placed between the second optical combining means ( 6 , 28 ) and the left eye ( 12 ) of the subject; and

means ( 30 , 31 , 32 , 33 ) for aligning said right optical system ( 9 , 11 , 21 , 33 ) and said left optical system ( 8 , 10 , 20 , 32 ) so as to adjust the pupillary distance depending on the prismatic convergence of the subject.

12. The binocular multiplexing device ( 100 ) as claimed in claim 1 , furthermore comprising an optical system ( 3 ) placed on the optical path of the stimulating image beam ( 14 ), said optical system ( 3 ) being able to correct an average sphere error of the two eyes ( 12 , 13 ).

13. The binocular multiplexing device ( 100 ) as claimed in claim 1 , furthermore comprising a first optical system ( 18 , 26 ) placed on the optical path of the right ocular stimulating beam ( 14 b ) and a second optical system ( 19 , 27 ) placed on the optical path of the left ocular stimulating beam ( 14 a ), said first optical system ( 18 , 26 ) and said second optical system ( 19 , 27 ) being able to correct a sphere and/or cylinder error of the right eye ( 13 ) and of the left eye ( 12 ) of the subject, respectively.

14. The binocular multiplexing device ( 100 ) as claimed in claim 1 , comprising:

a right optical system ( 9 , 11 , 21 ) placed between the first optical combining means ( 7 , 29 ) and the right eye ( 13 ) of the subject;

a left optical system ( 8 , 10 , 20 ) placed between the second optical combining means ( 6 , 28 ) and the left eye ( 12 ) of the subject; and

means ( 30 , 31 , 32 , 33 ) for aligning said right optical system ( 9 , 11 , 21 , 33 ) and said left optical system ( 8 , 10 , 20 , 32 ) so as to adjust the pupillary distance depending on the prismatic convergence of the subject.

15. The binocular multiplexing device as claimed in claim 1 , in which, the optical paths of the stimulating image beam ( 14 ), of the single illuminating beam ( 15 ) and of the single measuring beam ( 55 ) being merged, said binocular multiplexing device comprises:

third optical splitting means ( 42 ) able to receive and to spatially split said stimulating image beam ( 14 ) and said single illuminating beam ( 15 ), said third optical splitting means ( 42 ) being able to receive said single measuring beam ( 55 ) along an optical path that is the reverse of that of said single illuminating beam ( 15 ).

16. The binocular multiplexing device ( 100 ) as claimed in claim 1 , in which said third optical splitting means comprise a beam-splitting plate ( 42 ) able to split a stimulating image beam ( 14 ) in the visible domain and an illuminating beam ( 15 ) in the infrared domain.

17. The binocular multiplexing device ( 100 ) as claimed in claim 1 , comprising an electronic processing unit suitable for receiving a signal representative of the switching state of said optical switching means ( 5 , 24 , 43 , 44 , 45 ) and to receive, in sequence, a first measurement representative of said right ocular measuring beam ( 55 b ) and a second measurement representative of said left ocular measuring beam ( 55 a ), said electronic processing unit being able to combine said signal representative of the switching state and said first and second measurements in order to deliver a multiplexed binocular measurement of at least one vision parameter.

18. An ophthalmological instrument ( 120 ) for multiplexed binocular measurement of at least one vision parameter of a subject, said ophthalmological instrument comprising a binocular multiplexing device ( 100 ) according to claim 1 , and:

ophthalmological means ( 2 ) for measuring at least one vision parameter of a subject, said ophthalmological measuring means being able to generate a single illuminating beam ( 15 ) and to receive and analyze a single measuring beam ( 55 ) generated by reflection and/or refraction of said single illuminating beam from an eye ( 12 , 13 ) of the subject, said single illuminating beam ( 15 ) and said single measuring beam ( 55 ) following reciprocal optical paths between said ophthalmological measuring means ( 2 ) and the eye ( 12 , 13 ) of the subject.

19. A method for determining at least one binocular vision parameter of a subject, said method comprising the following steps:

a) delivering a stimulating image beam ( 14 ) for a proximity value P;

b) splitting the stimulating image beam ( 14 ) into a right ocular stimulating beam ( 14 b ) and a left ocular stimulating beam ( 14 a ) so as to stimulate accommodation by the right eye ( 13 ) and by the left eye ( 12 ) of the subject simultaneously;

c) generating a right monocular illuminating beam ( 15 b ) and/or a left monocular illuminating beam ( 15 a );

d) optically superposing said right ocular stimulating beam ( 14 b ) and said right monocular illuminating beam ( 15 b ) in a right optical channel ( 17 ) and/or optically superposing said left ocular stimulating beam ( 14 a ) and said left monocular illuminating beam ( 15 a ) in a left optical channel ( 16 ), respectively;

e) collecting the right monocular measuring beam ( 55 b ) or the left monocular measuring beam ( 55 a ) along an optical path that is the inverse of that of the right monocular illuminating beam ( 15 b ) and of the left monocular illuminating beam ( 15 a ), respectively;

f) analyzing the right monocular measuring beam ( 55 b ) or the left monocular measuring beam ( 55 a ) so as to determine at least one right monocular vision parameter or left monocular vision parameter, respectively; and

g) repeating steps c) to f) after switching of the monocular measuring beam ( 55 a , 55 b ), so as to determine at least one binocular vision parameter of a subject using the same ocular stimulations for the right eye ( 13 ) and left eye ( 12 ) of the subject.

20. A method for determining at least one objective binocular vision parameter of a subject, comprising carrying out the steps of the method as claimed in claim 19 for a first proximity value P1, then carrying out the steps of the method for at least one other proximity value Pn.

21. The method as claimed in claim 19 , in which step c) of generating a right monocular illuminating beam ( 15 b ) and/or a left monocular illuminating beam ( 15 a ) is carried out by dividing or switching a single illuminating beam ( 15 ).