Patent US5042939A successfully refreshed from Google Patents.
US5042939A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Laser scanning type eye fundus camera
Assignee: Topcon Corp
•
Filing: 1989-11-16
•
Granted: 1991-08-27
•
Expires: 2009-11-16
Abstract
Abstract A laser scanning type eye fundus camera is designed such that retina photographing for one frame is perofrmed alternately with two laser beams having two wavelengths among three laser beams wavelengths of the primary three colors and with one laser beam including the remaining one wavelength to obtain a retina image composed of the wavelengths of the respective primary colors which are combined to obtain one color retina image.
Inventors
- 👤 Francois Zayek
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 20:29
CPC Classifications
A; A61; A61B; A61B3/00; A61B3/10; A61B3/12; A61B3/1225
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
228 words
A laser scanning type eye fundus camera comprising: laser beam generating means for generating first, second, and third laser beams, each having a wavelength corresponding to one of the three primary colors; a scanning optical system for scanning a laser beam over the retina of an eye to be tested; switch means for selectively switching between a first group and a second group of the laser beams generated by said laser beam generating means and for guiding said selected group to said scanning optical system; control means for controlling said switch means to selectively switch between said first group and said second group in synchronization with said scanning optical system to allow said scanning optical system to alternately scan one frame of the retina of the eye with said first group and one frame of the retina of the eye with said second group; a light receiving optical system for guiding light reflected from the retina of the eye; first light receiving means for receiving reflected light guided by said light receiving optical system from said first and said second laser beams; second light receiving means for receiving reflected light guided by said light receiving optical system from said third laser beam; and image processing means for combining an output from said first and said second light receiving means to form a single color image of the retina.
Claim 2
Dependent Claim
228 words
A laser scanning type eye fundus camera comprising: laser beam generating means for generating first, second, and third laser beams, each having a wavelength corresponding to one of the three primary colors; a scanning optical system for scanning a laser beam over the retina of an eye to be tested; switch means for selectively switching between a first group and a second group of the laser beams generated by said laser beam generating means and for guiding said selected group to said scanning optical system; control means for controlling said switch means to selectively switch between said first group and said second group in synchronization with said scanning optical system to allow said scanning optical system to alternately scan one frame of the retina of the eye with said first group and one frame of the retina of the eye with said second group; a light receiving optical system for guiding light reflected from the retina of the eye; first light receiving means for receiving reflected light guided by said light receiving optical system from said first and said second laser beams; second light receiving means for receiving reflected light guided by said light receiving optical system from said third laser beam; and image processing means for combining an output from said first and said second light receiving means to form a single color image of the retina.
Claim 3
Dependent Claim
41 words
A laser scanning type eye fundus camera according to claim 1, wherein said laser beam generating means comprises first, second, and third laser emitting elements adapted to emit laser beams with wavelengths corresponding to blue light, green light, and red light.
Claim 4
Dependent Claim
30 words
A laser scanning type eye fundus camera according to claim 1, wherein said switch means includes a quick return mirror disposed in an optical path of said scanning optical system.
Claim 5
Dependent Claim
26 words
A laser scanning type eye fundus camera according to claim 1, wherein said switch means comprises a rotating disc plate with a semicircular light transmitting portion.
Claim 6
Dependent Claim
20 words
A laser scanning type eye fundus camera according to claim 1, wherein said switch means comprises a liquid crystal shutter.
Claim 7
Dependent Claim
42 words
A laser scanning type eye fundus camera according to claim 2, wherein said first group comprises a laser beam with a wavelength corresponding to blue light and said second group comprises laser beams with wavelengths corresponding to green light and red light.
Claim 8
Dependent Claim
32 words
A laser scanning type eye fundus camera according to claim 1, wherein said first group comprises said first laser beam and said second group comprises said second and said third laser beams.
Claim 9
Dependent Claim
46 words
A laser scanning type eye fundus camera according to claim 7, wherein said first laser beam has a wavelength corresponding to blue light, said second laser beam has a wavelength corresponding to green light, and said third laser beam has a wavelength corresponding to red light.
Claim 10
Dependent Claim
35 words
A laser scanning type eye fundus camera according to claim 1, wherein said first group comprises said first and said third laser beams and said second group comprises said second and said third laser beams.
Claim 11
Dependent Claim
46 words
A laser scanning type eye fundus camera according to claim 9, wherein said first laser beam has a wavelength corresponding to blue light, said second laser beam has a wavelength corresponding to green light, and said third laser beam has a wavelength corresponding to red light.
Claim 12
Dependent Claim
21 words
A laser scanning type eye fundus camera according to claim 1, wherein said laser beam generating means comprises a dichroic mirror.
Claim 13
Dependent Claim
21 words
A laser scanning type eye fundus camera according to claim 1, wherein said light receiving optical system comprises a dichroic mirror.
References Cited (Backward Citations)
US4781453A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-08-26 | 1995-02-25 | 1995-08-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-08-26 | 1999-02-25 | 1999-08-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-08-26 | 2003-02-25 | 2003-08-27 | $7700.00 | Window Closed / Lapsed |