US4764006A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ophthalmic measuring apparatus
Assignee: Canon Inc
•
Filing: 1986-09-10
•
Granted: 1988-08-16
•
Expires: 2006-09-10
Abstract
Abstract An ophthalmic measuring apparatus has an ultrasonic detector for measuring the length of a predetermined region of an eye to be examined, a device provided with a center axis coaxial with the center axis of the vibrator of the ultrasonic detector and projecting an index mark onto the cornea of the eye to be examined, and an imaging optical system for forming the corneal reflection image of the index mark on a predetermined image plane to measure the shape of the cornea.
Inventors
- 👤 Yoshimasa Hamano
- 👤 Takashi Masuda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 01:47
CPC Classifications
A; A61; A61B; A61B8/00; A61B8/10; A61B3/00; A61B3/10; A61B3/107; A61B3/14; A61B3/15; A61B3/152
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
137 words
An ophthalmic measuring apparatus comprising: an ultrasonic detector adapted to be positioned on the cornea of an eye to be examined for determining the length of a predetermined region of the eye to be examined by calculating the length of the predetermined region based on measuring the time required for the transmission and reception of an ultrasonic wave echo, wherein said ultrasonic detector comprises a vibrator; an index means for projecting an index mark onto the cornea of the eye to be examined, wherein the center axis of said index means is coaxial with the center axis of said vibrator of said ultrasonic detector; and an imaging optical system positioned coaxially with said index means, for forming the corneal reflection image of said index mark on a predetermined image plane to measure the shape of the cornea.
Claim 2
Dependent Claim
137 words
An ophthalmic measuring apparatus comprising: an ultrasonic detector adapted to be positioned on the cornea of an eye to be examined for determining the length of a predetermined region of the eye to be examined by calculating the length of the predetermined region based on measuring the time required for the transmission and reception of an ultrasonic wave echo, wherein said ultrasonic detector comprises a vibrator; an index means for projecting an index mark onto the cornea of the eye to be examined, wherein the center axis of said index means is coaxial with the center axis of said vibrator of said ultrasonic detector; and an imaging optical system positioned coaxially with said index means, for forming the corneal reflection image of said index mark on a predetermined image plane to measure the shape of the cornea.
Claim 3
Dependent Claim
48 words
An ophthalmic measuring apparatus according to claim 1, wherein at least a portion of a medium section of said ultrasonic detector is formed by a light transmitting member, and the corneal reflection image of said index mark is imaged on said image plane through said light transmitting member.
Claim 4
Dependent Claim
25 words
An ophthalmic measuring apparatus according to claim 2, provided with a fixation target presented to the eye to be examined through said light transmitting member.
Claim 5
Dependent Claim
23 words
An ophthalmic measuring apparatus according to claim 2, wherein a portion of said light transmitting member is provided with a light reflecting portion.
Claim 6
Dependent Claim
32 words
An ophthalmic measuring apparatus according to claim 2, wherein said vibrator is ring-shaped and said index mark is projected from the central opening in said vibrator onto the eye to be examined.
Claim 7
Dependent Claim
22 words
An ophthalmic measuring apparatus according to claim 2, wherein said index mark is provided at a position in said light transmitting member.
Claim 8
Dependent Claim
52 words
An ophthalmic measuring apparatus according to claim 6, wherein the end surface of said medium section which is adjacent to the eye to be examined is a light deflecting surface so that the light from said index mark emerges from said end surface and is deflected toward the eye to be examined.
Claim 9
Dependent Claim
19 words
An ophthalmic measuring apparatus according to claim 1, wherein light position detecting means is provided on said image plane.
Claim 10
Dependent Claim
30 words
An ophthalmic measuring apparatus according to claim 1, wherein said vibrator is provided on that side of said imaging optical system which is adjacent to the eye to be examined.
Claim 11
Dependent Claim
32 words
An ophthalmic measuring apparatus according to claim 1, wherein the corneal reflection image of said index mark passes around the outer side of said vibrator and is imaged on said image plane.
Claim 12
Dependent Claim
37 words
An ophthalmic measuring apparatus according to claim 1, wherein said vibrator is ring-shaped and the corneal reflection image of said index mark passes through the central opening in said vibrator and is imaged on said image plane.
Claim 13
Dependent Claim
14 words
An ophthalmic measuring apparatus according to claim 2, wherein said medium section is lens-like.
Claim 14
Dependent Claim
23 words
An ophthalmic measuring apparatus according to claim 2, wherein a portion of said medium section is provided with an ultrasonic wave reflecting surface.
Claim 15
Dependent Claim
38 words
An ophthalmic measuring apparatus according to claim 1, wherein said imaging optical system comprises an objective lens and a stop at a rearward focal plane of said objective lens, whereby said imaging optical system is a telecentric system.
Claim 16
Dependent Claim
17 words
An ophthalmic measuring apparatus according to claim 14, wherein said index means comprises a ring-shaped cylindrical lens.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-08-16 | 1992-02-15 | 1992-08-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-08-16 | 1996-02-15 | 1996-08-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-08-16 | 2000-02-15 | 2000-08-16 | $7700.00 | Window Closed / Lapsed |