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US 6,556,791 B1Granted
Dual channel optical imaging system
AssigneeEastman Kodak Company
InventorDonald E. Oinen
Life of this patent
Estimating the term…
Abstract
An image forming optical system especially suitable as a viewfinder system in an electronic or electronic/film (hybrid) camera includes an objective lens system, an electronic imaging channel, and a visual viewfinding imaging channel. The objective lens system is common to both the electronic and visual imaging channels, and provides a zoom function. The objective lens system is substantially afocal. The optical system includes an optical component that provides at least three reflections for the visual viewfinder image forming light.
Claims24
An image forming optical system, comprising:
- an electronic imaging channel having an optical axis that forms a first image of an object in an image plane, and
- a visual imaging channel having an optical axis that is at least in part common with the optical axis of the electronic imaging channel so as to form a common optical axis segment, that forms a virtual image of the object in another image plane, adapted such that the first image and the virtual image are substantially identical;
- and
- an objective lens system located along the common segment of the optical axis, the objective lens system including a first optical component having negative power as viewed from an object side, wherein the objective lens system is a zoom objective lens system located along the common optical axis segment providing a zoom ratio that is less than or equal to about 3×.
1 more element
The optical system of claim 6, wherein the beamsplitter is a beamsplitting cube.
An image forming optical system, comprising:
- an electronic imaging channel having an optical axis that forms a first image of an object in an image plane;
- a visual imaging channel having an optical axis that is at least in part common with the optical axis of the electronic imaging channel so as to form a common optical axis segment, that forms a virtual image of the object in another image plane, adapted such that the first image and the virtual image are substantially identical;
- an mth optical element located along the common optical axis segment that provides optical transmission for light of the first image and optical reflection for light of the virtual image;
- an nth optical element located along the optical axis in the visual imaging channel that provides at least three reflections of the light of the virtual image;
- and
- a light baffle located on the common optical axis segment on an object side of an objective system defining an input plane of the optical system, and a zth optical element located on the optical axis of the visual imaging channel on an object side of the nth optical element defining an output plane of the optical system, wherein the input plane and the output plane are parallel, and further wherein a separation distance between the input and output planes is less than or equal to 24 mm.
3 more elements
A viewfinder optical system for a camera, comprising:
- object in a an electronic imaging channel that forms a digital image of an object in a digital image medium, and
- a visual imaging channel that forms a virtual viewfinder image of the object for viewing by a user of the camera, adapted to form substantially identical first and virtual images, further comprising an optical element that is common to the electronic imaging channel and the visual imaging channel wherein the optical element transmits at least a portion of light from the object to form one of the digital and the virtual images, and
- another optical element having at least three reflective surfaces, located in the visual imaging channel, wherein a distance as measured in a plane parallel to a portion of the electronic imaging channel and the visual imaging channel is less than or equal to 24 mm, and the optical element that is common to the electronic imaging channel and the visual imaging channel includes a zoom lens system.
A viewfinder optical system for a camera, comprising:
- an electronic imaging channel constructed according to the following table:
- CLEAR AXIAL SURF. APER. BEAM RADIUS THICKNESS GLASS SPECIAL NOTES 6.74 × 8.83 3.06 BAFFLE A 1 6.11 × 8.37 3.10 20.4791 0.750 883408 OHARA S-LAH58 2 5.67 × 7.33 3.03 6.6466 B 3 8.37 4.60 13.2967 1.833 835427 OHARA S-LAH55 4 8.27 4.59 −19.1063 C 3.03 3.03 DIAPHRAGM 3.240 5 3.31 × 5.96 2.33 PLANO 517642 SCHOTT BK7 6 3.34 × 6.58 2.25 PLANO 7 4.61 1.47 PLANO 0.075 660300 POLYESTER 8 4.63 1.46 PLANO 0.7029 9 4.91 1.30 5.777 2.5168 883408 OHARA S-LAH58 10 4.40 0.75 −6.710 0.300 11 3.90 0.59 −4.789 0.810 847238 OHARA S-TIH53 12 3.66 0.41 −46.715 0.446 13 3.44 0.24 PLANO 0.500 511510 OHARA FTL8 14 3.28 0.10 PLANO 0.425 529517 OHARA SSL2 15 3.32 0.03 PLANO;
- and
- a visual imaging channel constructed according to the following table:
- CLEAR AXIAL SURF. APER. BEAM RADIUS THICKNESS GLASS SPECIAL NOTES 6.74 × 8.83 3.10 BAFFLE A 1 6.11 × 8.37 3.10 20.4791 0.750 883408 OHARA S-LAH58 2 5.67 × 7.33 3.03 6.6466 B 3 8.37 4.60 13.2967 1.833 835427 OHARA S-LAH55 4 8.27 4.59 −19.1063 C 3.03 3.03 DIAPHRAGM 3.240 5 3.31 × 5.96 2.33 PLANO −5.942 REFL. BEAMSPLITTER (MIRROR) 6′ 3.18 × 4.69 1.06 ASPHERE −3.909 590309 DOW685 7′ 4.14 × 6.84 0.78 214.2158 −2.958 8′ 5.25 × 9.57 0.45 −23.5217 −3.174 525563 ZEONEX 480R 9′ 5.75 × 10.30 0.15 ASPHERE −0.750 10′ 5.6* × 10.2* 0.05 PLANO −6.882 FIELD STOP 11′ 7.73 × 13.05 0.89 −10.6618 −5.579 525563 ZEONEX 480R 12′ 7.25 × 12.10 1.21 ASPHERE −2.004 13′ 6.67 × 11.15 1.31 12.500 −5.772 525563 ZEONEX 480R PRISM FACE 14′ 9.41 × 10.73 2.37 PLANO 7.500 REFL. ZEONEX 480R-PRISM 15′ 9.34 × 10.29 3.34 PLANO −8.253 REFL. ZEONEX 480R-PRISM 16′ 6.52 × 14.28 2.87 PLANO 12.888 REFL. ZEONEX 480R-PRISM 17′ 6.44 × 9.10 3.79 −9.3851 1.031 PRISM FACE 18′ 8.28 3.68 −7.7269 1.500 590309 DOW685 19′ 8.45 3.88 40.16704 0.750 20′ 8.65 4.08 25.43669 2.666 525563 ZEONEX 480R 21′ 8.68 4.32 −14.77141;
- REFRACTIVE INDEX DATA FOR ZEONEX Z480R:
- WAVE- 786.5 656.3 587.6 546.1 486.1 435.8 LENGTH INDEX 1.51862 1.52196 1.52470 1.52692 1.53129 1.53649 ASPHERIC EQUATION SAG = [cy2/[1 + (1 − c2y2)] + Dy4 SURF RADIUS CURVATURE D THICKNESS MATERIAL 6′ −6.21371 −0.160934450 −1.857860E−03 3.909 DOW685 7′ −214.2158 8′ 23.5217 3.714 ZEONEX 9′ −14.87332 −0.067234484 −1.285630E−03 11′ −10.6618 12′ −20.69256 −0.048326548 2.008580E−04 5.579 ZEONEX,
- wherein distances are in millimeters, and the surfaces are numbered from an object side to a viewing side of the viewfinder.
5 more elements
In a hybrid camera that provides for capture of an analogue image of an object on a film medium and for capture and viewing of a digital image of the object in an electronic medium, the improvement comprising:
- a viewfinder optical system incorporated into the hybrid camera, including an electronic imaging channel having an optical axis that forms the digital image of the object, and a visual imaging channel having an optical axis that has a common segment with the optical axis of the electronic imaging channel, that forms a virtual image of the object in an eyepiece of the viewfinder system, adapted such that the digital image and the virtual image are substantially identical;
- and
- an objective lens system located along the common segment of the optical axis, the objective lens system including a first optical component having negative power as viewed from an object side, wherein the objective lens system is a zoom objective lens system located along the common optical axis segment providing a zoom ratio that is less than about 3×.
A method for capturing images, comprising the steps of:
- providing a hybrid camera including a viewfinder optical system and a separate image taking optical system, the viewfinder optical system including a common segment having a zoom objective lens system;
- forming an analog image of an object on an analog image capture medium with the image taking optical system;
- and
- forming a virtual image of the object with the viewfinder optical system and forming a substantially identical digital image of the object on an electronic image capture medium with the viewfinder optical system by passing light from the object through the common segment of the viewfinder optical system, wherein the common segment of the viewfinder optical system includes at least a portion of a system forming the virtual image of the object and at least a portion of a system forming the substantially identical digital image of the object.
1 more element
Dependencies are inferred from the claim text.