EP0172680A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Sequential colour light sources for endoscopes of the type employing a solid-state imaging device
Assignee: Olympus Corp
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Filing: 1985-07-26
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Granted: —
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Expires: 2005-07-26
Abstract
Abstract A light source (11) for illuminating a subject to be viewed through an endoscope (1) employing a solid-state imaging device (4), the object being illuminated sequentially with light transmitted through three colour-transmitting filters on a filter wheel (16) in the path of light from a light source lamp (12) that is formed into a parallel light beam by a reflector (13), and a convex lens system (14) for converging the light beam on the input end of a light guide (10) to feed light through the insertion sheath (2) of said endoscope (1), and at least two lens systems (15,17) between said reflector (13) for reducing the cross-sectional area and included angle of the light beam at the rotary filter wheel (16), which is formed with interference filters having high heat resistance.
Inventors
- 👤 Hiroyoshi Fujimori
- 👤 Tatsuo Nagasaki
- 👤 Tadashi Kato
- 👤 Masahiko Sasaki
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-23 06:59
CPC Classifications
A; A61; A61B; A61B1/00; A61B1/06; A61B1/0638; A61B1/0646; A61B1/0661; A61B1/0669; H; H04; H04N; H04N23/00; H04N23/70; H04N23/74; H04N23/50; H04N23/555
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
198 words
A sequential colour light source for an endoscope (1) incorporating an elongate insertion sheath (2) housing at its distal end an objective lens (3) with a solid-state imaging device (4) aligned with the focal plane of said objective lens, and a light guide (10) passing through said insertion sheath to project illuminating light to a subject positioned before said objective lens, said light source comprising a lamp (12), a reflector (13) producing a substantially parallel light beam, a converging convex lens system (14) concentrating the light beam onto the input end of an output light guide, and a rotary colour filter wheel (16) formed with independent colour-transmitting filters (16B, 16G, 16R) positioned on the optical path from the reflector to sequentially illuminate a subject with light having different respective wavelengths when operating with said rotary colour filter wheel driven to rotate, characterised in that two lens systems (15,17; 33,17; 41,17; 42,41,17) are arranged on the optical path from said converging lens system (14) to reduce the cross-sectional area of the beam perpendicular to the optical axis and so make the included angle of the beam incident on the colour filter wheel (16), which wheel comprises respective interference filters.
Claim 2
Dependent Claim
198 words
A sequential colour light source for an endoscope (1) incorporating an elongate insertion sheath (2) housing at its distal end an objective lens (3) with a solid-state imaging device (4) aligned with the focal plane of said objective lens, and a light guide (10) passing through said insertion sheath to project illuminating light to a subject positioned before said objective lens, said light source comprising a lamp (12), a reflector (13) producing a substantially parallel light beam, a converging convex lens system (14) concentrating the light beam onto the input end of an output light guide, and a rotary colour filter wheel (16) formed with independent colour-transmitting filters (16B, 16G, 16R) positioned on the optical path from the reflector to sequentially illuminate a subject with light having different respective wavelengths when operating with said rotary colour filter wheel driven to rotate, characterised in that two lens systems (15,17; 33,17; 41,17; 42,41,17) are arranged on the optical path from said converging lens system (14) to reduce the cross-sectional area of the beam perpendicular to the optical axis and so make the included angle of the beam incident on the colour filter wheel (16), which wheel comprises respective interference filters.
Claim 3
Dependent Claim
28 words
A source as claimed in Claim 1, characterised in that said two lens systems comprise a convex lens system (17) and a concave lens sytem (15; 41; 41,42).
Claim 4
Dependent Claim
20 words
A source as claimed in Claim 1, characterised in that said two lens systems comprise two convex lens systems (17,33).
Claim 5
Dependent Claim
33 words
A source as claimed in Claim 2 or Claim 3, characterised in that an iris (36) is provided at the vicinity of a focus of the converging light beam before said filter wheel.
Claim 6
Dependent Claim
71 words
An endoscope comprising a light source as claimed in any preceding Claim, characterised in that said solid-state imaging device (4) feeds an output signal to a video processor (7) for memorizing the electrical signals corresponding to the picture elements issued from said solid-state imaging device, defined by applying clock signals to cause sequential colour signals to be issued to display means (8) for displaying colour signals fed from said video processor.
Claim 7
Dependent Claim
82 words
An endoscope as claimed in Claim 5, characterised in that means (21) are provided for automatically controlling the light intensity for forming a brightness signal by adding the colour signals from said endoscope, means (22) for integrating said brightness signals for a time constant of approximately one frame period, and means (23) for controlling the intensity of illuminating light from said light source by applying the output from said integrating means to the power source for the lamp of said light source.
References Cited (Backward Citations)
GB1340767A
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US4074306A
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EP0018874A1
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EP0048410A1
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EP0050834A1
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EP0115874A1
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