Small and fast zoom system ktRGl>J
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Abstract tv Zq):c
There is a need for a small and fast optical zoom device that can change magnification. Conventional zoom devices require coupled mechanical motions to adjust the axial separations between individual or groups of elements in order to change the optical magnification. The mechanical motions decrease the speed of zooming, increase space and weight for zoom system, may induce unwanted jitter, and require large power consumption. In addition, the mechanical zoom system is restricted to magnifying the area on-axis. To solve problems of conventional zoom system, the zoom system utilizing one or more variable focal length micromirror array lenses without macroscopic mechanical motion of lenses is invented. sl"H!cwF
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Inventors: Cho, Gyoung Il; (Seoul, KR) ; Gim, Dong Woo; (Gyoungnam, KR) ; Seo, Cheong Soo; (Seoul, KR) ; Boyd, James Greenup; (Brenham, TX) ; Baek, Sang Hyune; (Suwon, KR) x<OVtAUB
Correspondence Name and Address: PARK & SUTTON LLP Jw>na _FJ
3255 WILSHIRE BLVD m>3\1`ZF~<
SUITE 1110 fW[RCd
LOS ANGELES So75h*e
CA l_8ibLyo
90010 xJnN95`R@
US NTO.;S|2%
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Serial No.: 806299 uRYq.`v,
Series Code: 10 2[j`bYNe
Filed: March 22, 2004 ?>I
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U.S. Current Class: 359/676 AX'-}5T=
U.S. Class at Publication: 359/676 th<>%e}5c
Intern'l Class: G02B 015/14; G02B 015/15 !N_eZPU.v
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Claims HuKOb4g
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1. A zoom system for forming an image with varying magnification comprising one or more variable focal length lenses, wherein the variable focal length lens is made of a micromirror array lens, wherein the micromirror array lens comprises a plurality of micromirrors, wherein each micromirror is controlled to change the focal length of the micromirror array lens, wherein the micromirror array lens further comprises a plurality of mechanical structures upholding the micromirrors and actuating components actuating the micromirrors. `I4E':
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4. The zoom system of claim 1, wherein the translation of each micromirror of the micromirror array lens is controlled. 'NCx <0*
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5. The zoom system of claim 1, wherein the rotation of each micromirror of the micromirror array lens is controlled. +?[s"(
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6. The zoom system of claim 1, wherein the translation and rotation of each micromirror of the micromirror array lens are controlled. F\GNLi
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7. The zoom system of claim 1, wherein the micromirrors of the micromirror array lens are arranged to form one or more concentric circles. fC[~X[H
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8. The zoom system of claim 1, wherein each micromirror of the micromirror array lens has a fan shape. \m1^sFMZ
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9. The zoom system of claim 1, wherein the reflective surface of each micromirror of the micromirror array lens is substantially flat. k*C[-5&#
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10. The zoom system of claim 1, wherein the reflective surface of each micromirror of the micromirror array lens has a curvature. R~|(]#com
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11. The zoom system of claim 10, wherein the curvature is controlled. G )`gn
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12. The zoom system of claim 1, wherein each micromirror of the micromirror array lens is actuated by electrostatic force. %`\Qtsape
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13. The zoom system of claim 1, wherein each micromirror of the micromirror array lens is actuated by electromagnetic force %$Xt1ub6(
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14. The zoom system of claim 1, wherein each micromirror of the micromirror array lens is actuated by electrostatic force and electromagnetic force. cS2]?zI
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15. The zoom system of claim 1, wherein the mechanical structure and the actuating components are located under the micromirrors. y\[* mgl:
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16. The zoom system of claim 1, wherein the micromirror array lens is a reflective Fresnel lens. 4L4u<
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17. The zoom system of claim 1, wherein the micromirrors are arranged in a flat plane. .cx9+;
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18. The zoom system of claim 1, and wherein each micromirror is controlled to change the focal length of the micromirror array lens. (:%t
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19. The zoom system of claim 1, wherein the micromirror array lens is an adaptive optical component, wherein the micromirror array lens compensates for phase errors of light introduced by the medium between an object and its image. rY1jC\
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20. The zoom system of claim 1, wherein the micromirror array lens is an adaptive optical component, wherein the micromirror array lens corrects aberrations. 1,U)rx$H
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21. The zoom system of claim 1, wherein the micromirror array lens is an adaptive optical component, wherein the micromiror array lens corrects the defects of the zoom system that cause the image to deviate from the rules of paraxial imagery. v6E5#pse8
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22. The zoom system of claim 1, wherein the micromirror array lens is an adaptive optical component, wherein an object which does not lie on the optical axis can be imaged by the micromirror array lens without macroscopic mechanical movement of zoom system. =NnG[#n%
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23. The zoom system of claim 1, wherein the micromirror array lens is controlled to satisfy the same phase condition for each wavelength of Red, Green, and Blue (RGB), respectively, to get a color image. Ir*{IVvej
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24. The zoom system of claim 23, further comprising a plurality of bandpass filters. Y%@;\
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25. The zoom system of claim 23, further comprising a photoelectric sensor, wherein the photoelectric sensor comprises Red, Green, and Blue (RGB) sensors, wherein a color image is obtained by treatment of electrical signals from the Red, Green, and Blue (RGB) sensors. UlKg2p
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26. The zoom system of claim 25, wherein the treatment of electrical signals from the Red, Green and Blue (RGB) sensors is synchronized and/or matched with the control of the micromirror array lens to satisfy the same phase condition for each wavelength of Red, Green and Blue (RGB), respectively. jqTK7b
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27. The zoom system of claim 1, wherein the variable focal length lenses comprise a first variable focal length lens and a second variable focal length lens, wherein the focal length of the first variable focal length lens and the focal length of the second variable focal length lens are changed to form the image in-focus at a given magnification. ,9ew75Jl
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28. The zoom system of claim 27, wherein the first variable focal length lens is made of a micromirror array lens, wherein the micromirror array lens comprises a plurality of micromirrors. oz[G'[\}F
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29. The zoom system of claim 27, wherein the second variable focal length lens is made of a micromirror array lens, wherein the micromirror array lens comprises a plurality of micromirrors. HqV4!o9'
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30. The zoom system of claim 27, wherein the first variable focal length lens and the second variable focal length lens are made of micromirror array lenses, wherein each of the micromirror array lenses comprises a plurality of micromirrors. Bsd~_y}8
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31. The zoom system of claim 27, further comprising a beam splitter is positioned between the first variable focal length lens and the second variable focal length lens. jIHY[yDT
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32. The zoom system of claim 27, wherein the first variable focal length lens and the second variable focal length lens are positioned so that the path of the light reflected by the first variable focal length lens and the second variable focal length lens is not blocked. 322-'S3<
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33. The zoom system of claim 27, further comprising a focus lens group, an elector lens group and a relay lens group, wherein the first variable focal length lens forms a variator lens group, and the second variable focal length lens forms a compensator lens group. -lq`EB+
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Description 1|>bG#|
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BACKGROUND OF THE INVENTION %zDi|WZ
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[0001] The present invention relates to an optical zoom device and operational methods for the device. vkM_a}%<
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[0002] Conventional zoom devices require coupled mechanical motions to adjust the axial separations between individual or groups of elements in order to change the optical magnification. <;jg/
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[0003] FIG. 1 illustrates conventional mechanical zoom system. At the very basic level, a zoom system includes at least one moving lens for zooming. One lens to change the image size is called the variator 1 and another lens to maintain focus through the zoom range is called the compensator 2. The variator 1 is moved to change the image size of object. However, the image is defocused because the imaging position is also changed. Therefore, the variator 1 must move in unison with the compensator lens 2 to zoom and keep the image 3 in focus. These movements are usually mechanically controlled by a zoom ring on the lens barrel. MI.OOoP3a
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[0004] The mechanical motions decrease the speed of zooming, increase space and weight for zoom system, may induce unwanted jitter, and require large power consumption. In addition, the mechanical zoom system is restricted to magnifying the area on-axis. Therefore, there has been a need for a small and fast zoom device that can change magnification. beV+3HqB8
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SUMMARY OF THE INVENTION U^K8^an$
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[0005] The present invention contrives to solve the disadvantages of the conventional zoom system. &Wk:>9]Jrb
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[0006] An objective of the invention is to provide a zoom system that is compact and does not have macroscopic mechanical motions of lenses. f3h]t0M
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[0007] Another object of the invention is to provide a zoom system that consumes minimal power. uBC#4cX`D*
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[0008] Still another object of the invention is to provide a zoom system that can compensate various optical distortions or aberrations. -&)
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[0009] To achieve the above objectives, a zoom system for forming an image with varying magnification including one or more variable focal length lenses is provided. ')2LP;(
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[0010] The variable focal length lenses include a first variable focal length lens and a second variable focal length lens. The focal lengths of the variable focal length lenses are changed to form the image in-focus at a given magnification. 5a2;@}%V
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[0011] The variable focal length lenses are made of micromirror array lenses. The micromirror array lens include a plurality of micromirrors. xf|C{XV@H
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[0012] The translation and/or rotation of each micromirror of the micromirror array lens is controlled to get the desired functions of the zoom system. A,7* 52U
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[0013] The micromirrors of the micromirror array lens are arranged to form one or more concentric circles. lACS^(
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[0014] Each micromirror of the micromirror array lens may have a fan shape. gzlRK^5
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[0015] The reflective surface of each micromirror of the micromirror array lens is substantially flat. Alternatively, the reflective surface of each micromirror of the micromirror array lens has a curvature. The curvature of the micromirror may be controlled. 9PaV*S(\TR
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[0016] Each micromirror of the micromirror array lens is actuated by electrostatic force and/or electromagnetic force. /L2.7`5
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[0017] The micromirror array lens further includes a plurality of mechanical structure upholding the micromirrors and actuating components actuating the micromirrors. The mechanical structures and the actuating components are located under the micromirrors. KmWd$Qy,
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[0018] The micromirror array lens is a reflective Fresnel lens, and the micromirrors are arranged in a flat plane. y`7b3*P
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[0019] The zoom system includes a beam splitter positioned between the first variable focal length lens and the second variable focal length lens. Alternatively, the first variable focal length lens and the second variable focal length lens are positioned so that the path of the light reflected by the first variable focal length lens and the second variable focal length lens is not blocked. 5 (q4o`
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[0020] Each micromirror is controlled to change the focal length of the micromirror array lens. Zl.,pcL
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[0021] The micromirror array lens is an adaptive optical component. The micromirror array lens compensates for phase errors of light introduced by the medium between an object and its image and/or corrects the defects of the zoom system that may cause the image to deviate from the rules of paraxial imagery. Also, an object which does not lie on the optical axis can be imaged by the micromirror array lens without macroscopic mechanical movement of the zoom system. wawJZ+V
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[0022] The zoom system may further include a focus lens group, an elector lens group and a relay lens group. The first variable focal length lens forms a variator lens group, and the second variable focal length lens forms a compensator lens group. lcfs
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[0023] The micromirror array lens is controlled to satisfy the same phase condition for each wavelength of Red, Green, and Blue (RGB), respectively, to get a color image. The zoom system may further include a plurality of bandpass filters for color imaging. Also, the zoom system may further include a photoelectric sensor. The photoelectric sensor includes Red, Green, and Blue (RGB) sensors. A color image is obtained by treatment of electrical signals from the Red, Green, and Blue (RGB) sensors. The treatment of electrical signals from the Red, Green and Blue (RGB) sensors is synchronized and/or matched with the control of the micromirror array lens to satisfy the same phase condition for each wavelength of Red, Green and Blue (RGB), respectively. ="AaC!E,W
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[0024] The zoom system of the present invention includes one or more variable focal-length micromirror array lenses. The zoom system can change the magnification of an imaging system without macroscopic mechanical motions of lenses. The micromirror array lens includes micromirrors and actuating components, and uses a very simple mechanism to control the focal length. The focal length of the micromirror array lens is changed with the translation and/or rotation of each micromirror. !|mzu1S
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[0025] The micromirror has a tiny mass. Therefore, the lens comprising the micromirror has a very fast response time down to hundreds of microseconds. The lens also has a large focal length variation and a high optical focusing efficiency. In addition, the lens makes possible a large size lens, makes the focusing system very simple, and requires low power consumption. The lens has a low production cost because of the advantage of mass productivity. The lens can also compensate for optical effects introduced by the medium between the object and its image and/or corrects the defects of a lens system that cause the image to deviate from the rules of paraxial imagery. P"[{s^mb
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