Classifications

• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B7/00—Mountings, adjusting means, or light-tight connections, for optical elements
  • G02B7/02—Mountings, adjusting means, or light-tight connections, for optical elements for lenses
  • G02B7/04—Mountings, adjusting means, or light-tight connections, for optical elements for lenses with mechanism for focusing or varying magnification
  • G02B7/10—Mountings, adjusting means, or light-tight connections, for optical elements for lenses with mechanism for focusing or varying magnification by relative axial movement of several lenses, e.g. of varifocal objective lens
  • G02B7/102—Mountings, adjusting means, or light-tight connections, for optical elements for lenses with mechanism for focusing or varying magnification by relative axial movement of several lenses, e.g. of varifocal objective lens controlled by a microcomputer
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N25/00—Circuitry of solid-state image sensors [SSIS]; Control thereof
  • H04N25/60—Noise processing, e.g. detecting, correcting, reducing or removing noise
  • H04N25/61—Noise processing, e.g. detecting, correcting, reducing or removing noise the noise originating only from the lens unit, e.g. flare, shading, vignetting or "cos4"
  • H04N25/615—Noise processing, e.g. detecting, correcting, reducing or removing noise the noise originating only from the lens unit, e.g. flare, shading, vignetting or "cos4" involving a transfer function modelling the optical system, e.g. optical transfer function [OTF], phase transfer function [PhTF] or modulation transfer function [MTF]
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
  • G02B27/0025—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00 for optical correction, e.g. distorsion, aberration
  • G02B27/0068—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00 for optical correction, e.g. distorsion, aberration having means for controlling the degree of correction, e.g. using phase modulators, movable elements

Definitions

• he present invention relates to an image pickup apparatus, and is suitable for a digital still camera, a video camera, a TV camera and the like, which are provided, on an optical path of an image pickup optical system thereof, with such a correction unit, for example a phase modulating element, for effectively correcting aberration in the image pickup optical system.
• a correction unit for example a phase modulating element
• an aspherical lens is used to perform aberration correction with respect to a beam having a large angle of field.
• the image pickup angle of field becomes larger (as the angle of field becomes wider) , there occur more frequently coma, field curvature/astigmatism and the like.
• the number of lenses is increased, and aspherical lenses are used.
• Optical elements (lenses) used in an image pickup optical system are unchangeable in shape. For this reason, even if the surface of a lens has a curvature or an aspherical shape optimal for a given angle of field (zoom position) or a focus position, this shape is not necessarily optimal for another angle of field (zoom position) or another focus position .
• all aberrations in an optical system can be expressed as a pupil aberration at a pupil of the optical system.
• an imaging optical system in which a phase modulating element is interposed at the pupil of the optical system to correct the spherical aberration, and conversely add the spherical aberration to obtain a soft-focus effect (PTL 3) .
• NPL 1 Japanese Journal of Optics, Vol. 36, No. 3, 2007 Summary of Invention
• the present invention has an object to provide an image pickup apparatus which favorably corrects aberration with respect to both an axial beam and an off-axial beam having a certain angle of field, and thus achieves high optical performance over an entire screen.
• an image pickup apparatus including: an image pickup element; an image pickup optical system for forming an image of an object on the image pickup element by using a beam from the object; a phase modulating element disposed on a pupil plane of the image pickup optical system, for modulating a phase state of the beam from the object; a modulating element controller for controlling the phase modulating element; and an image pickup element controller for dividing the image pickup element into multiple areas, and reading, for each of the multiple divided areas, information on the image formed on the image pickup element in a time-sharing manner, in which, when the image pickup element controller reads the information on the image formed on the image pickup element by an area-by-area basis for the multiple divided areas in the time-sharing manner, the modulating element controller controls the phase modulating element so as to reduce a wavefront aberration in the divided area from which the information is to be read.
• Fig. 1 is an explanatory diagram of a first embodiment of the present invention.
• Fig. 2 is a diagram illustrating an area division pattern on an image plane according to the first embodiment.
• Fig. 3A is a diagram illustrating wavefront
• Fig. 3B is a diagram illustrating wavefront
• Fig. 3C is a diagram illustrating wavefront
• Fig. 3D is a diagram illustrating wavefront
• Fig. 4A is a diagram illustrating spots of the
• Fig. 4B is a diagram illustrating spots of the
• Fig. 4C is a diagram illustrating spots of the
• Fig. 4D is a diagram illustrating spots of the
• FIG. 5 is an explanatory diagram of a second
• Fig. 6 is a diagram illustrating relation between an angle of field and a wavefront aberration amount
• Fig. 7 is a diagram illustrating positions of angle of field in each area according to the second embodiment.
• Fig. 8 is a diagram illustrating spots of an area il obtained before and after the phase modulating element performs the modulation according to the second embodiment.
• Fig. 9 is a diagram illustrating wavefront
• Fig. 10 is a diagram illustrating phase modulating amounts provided to the phase modulating element with regard to the area il according to the second embodiment.
• Fig. 11 is a diagram illustrating spots of an area dl obtained before and after the phase modulating element performs the modulation according to the second embodiment.
• Fig. 12 is a diagram illustrating wavefront
• Fig. 13 is a diagram illustrating phase modulating amounts provided to the phase modulating element with regard to the area dl according to the second embodiment.
• Fig. 14 is a diagram illustrating spots of an area a obtained before and after the phase modulating element performs the modulation according to the second embodiment.
• Fig. 15 is a diagram illustrating wavefront
• Fig. 16 is a diagram illustrating phase modulating amounts provided to the phase modulating element with regard to the area a according to the second embodiment.
• FIG. 17 is an explanatory diagram of a third
• Fig. 18A is a diagram illustrating relation
• Fig. 18B is a diagram illustrating relation between the angle of field and the wavefront aberration amount at a telephoto end according to the third embodiment.
• Fig. 19A is a diagram illustrating an area
• Fig. 19B is a diagram illustrating an area
• Fig. 20 is a diagram illustrating spots of an area il (wide side) obtained before and after the phase
• modulating element performs the modulation according to the third embodiment .
• Fig. 21 is a diagram illustrating wavefront
• Fig. 22 is a diagram illustrating phase modulating amounts provided to the phase modulating element with regard to the area il (wide side) according to the third embodiment .
• Fig. 23 is a diagram illustrating spots of an area dl (wide side) obtained before and after the phase
• modulating element performs the modulation according to the third embodiment.
• Fig. 24 is a diagram illustrating wavefront
• Fig. 25 is a diagram illustrating phase modulating amounts provided to the phase modulating element with regard to the area dl (wide side) according to the third embodiment .
• Fig. 26 is a diagram illustrating spots of an area a (wide side) obtained before and after the phase
• modulating element performs the modulation according to the third embodiment.
• Fig. 27 is a diagram illustrating wavefront
• Fig. 28 is a diagram illustrating phase modulating amounts provided to the phase modulating element with regard to the area a (wide side) according to the third embodiment .
• Fig. 29 is a diagram illustrating spots of an area dl ' (telephoto side) obtained before and after the phase modulating element performs the modulation according to the third embodiment.
• Fig. 30 is a diagram illustrating wavefront
• Fig. 31 is a diagram illustrating phase modulating amounts provided to the phase modulating element with regard to the area dl ' (telephoto side) according to the third embodiment.
• Fig. 32 is a diagram illustrating spots of an area a' (telephoto side) obtained before and after the phase modulating element performs the modulation according to the third embodiment.
• Fig. 33 is a diagram illustrating wavefront
• Fig. 34 is a diagram illustrating phase modulating amounts provided to the phase modulating element with regard to the area a' (telephoto side) according to the third embodiment.
• Fig. 35 is a diagram illustrating an example of weighting performed on respective points in an area
• Fig. 36 is a diagram illustrating an example of a process in which data is read from an LUT and image pickup is then performed according to the third embodiment.
• Fig. 37 is a diagram for describing a fourth
• the present invention has an object to provide an image pickup apparatus which favorably corrects aberration with respect to both an axial beam and an off-axial beam having a certain angle of field, and thus achieves high optical performance over an entire screen.
• the image pickup apparatus of the present invention uses an image pickup optical system 105 having a single focal length or a zoom function to form image information of an external world (object) on a CCD or CMOS image pickup element 102.
• the pupil plane is such a surface that is perpendicular to an optical axis at a point at which an off-axial principal ray intersects the optical axis .
• invention includes a modulating element controller 108 which controls the phase modulating element 101 to provide a phase amount to a beam passing through the phase
• controller 109 which divides the image pickup element 102 into three or more areas and reads the image information by an area-by-area basis for the multiple divided areas in a time-sharing manner.
• the modulating element controller 109 reads the image information by an area-by- area basis for the multiple divided areas in a time-sharing manner, the modulating element controller 108 attempts to reduce a wavefront aberration for each of the divided areas of the image pickup element 102. Specifically, the phase modulating element 101 modulates the phase amount to be provided to the passing beam.
• aberration corresponds to such aberration that occurs as a result of superimposition of various kinds of aberrations.
• an area containing the center of the image pickup element 102 has the largest size or has the same size as the other areas. That is, no area is included in the multiple divided areas whose size is larger than the area containing the center of the image pickup element 102 in the multiple divided areas. In other word, the area containing the center of the image pickup element 102 has the largest size in the multiple divided areas.
• the number of divided areas is changed depending on a zoom position of the image pickup optical system 105. For example, the number of divided areas is set to be larger at a wide-angle end than at a telephoto end.
• the phase amount modulated by the phase modulating element 101 is set so as to minimize the
• the phase modulating element may be formed of an element whose thickness is partially variable .
• Fig. 1 is a main part schematic diagram of the first
• Fig. 1 is a main part schematic diagram in which the phase modulating element 101 according to the present invention is added to the wide- angle lens (optical system) (image pickup optical system) described in PTL 4.
• the wavefront aberration of the d-line (594 ran) is used for the calculation of the wavefront aberration.
• the wavelength may be selected arbitrarily depending on wavelengths that use the optical system. Further, in a case of using wavelengths in a wide band, other calculation methods may be employed, such as using a wavelength
• the aspect ratio of the image pickup element 102 is defined as 3:2, but the aspect ratio of the image pickup element 102 is not limited thereto .
• the optical system 105 is a wide-angle lens
• modulating element 101 is disposed at the position of the pupil 103 of the optical system 105 or its vicinity.
• phase modulating element 101 examples include a liquid crystal and a non-linear crystal, which are made of a material that is changeable in refractive index by
• phase modulating element 101 may be an element that is made of a transmissive
• phase modulating element 101 may be an element whose thickness is partially changeable.
• phase modulating amount is
• phase modulating amount ⁇ is expressed as follows:
• ⁇ ⁇ ⁇ ⁇ / ⁇
• ⁇ represents the change amount of the refractive index
• T represents the thickness of the material
• ⁇ represents the used wavelength.
• ⁇ represents the change amount of the refractive index
• T represents the thickness of the material
• ⁇ represents the used wavelength.
• ⁇ represents the change amount of the refractive index
• T represents the thickness of the material
• ⁇ represents the used wavelength.
• ⁇ represents the change in refractive index
• a change in refractive index may also be realized by using a material (non-linear crystal element) having a nonlinear optical characteristic such as the Pockels effect or the Kerr effect.
• a change in the refractive index of a liquid crystal or a crystal has polarization
• the following method may be used. That is, when used in an image pickup optical system (optical system) , two sheets of liquid crystals are attached together so as to make their
• a transparent body having a refractive index of 1 or larger such as a gel or a liquid, may be
• the phase modulating amount is determined based on a difference in thickness and the refractive index of the material.
• CMOS image pickup element 102 is divided into multiple areas by the image pickup element controller 109 as
• a division number is nine, and that all of nine divided areas 301 have the same size.
• the division number may be any number as long as the division number is equal to or larger than three.
• Figs. 3A to 3D respectively illustrate the wavefront aberrations corresponding to the central angles of field of the respective areas 301.
• Figs. 3A to 3D respectively illustrate the wavefront aberrations of the respective angles of field in the cross section illustrated in Fig. 1.
• the wavefront aberrations of areas d2 to d4 have the same shapes as the wavefront aberration of an area dl, which are respectively rotated about an optical axis 106.
• the wavefront aberrations in areas bl and b2 have shapes symmetric to each other about the optical axis 106. The same applies for areas cl and c2.
• Fig. 3A corresponds to an area a of Fig. 2, Fig. 3B
• Fig. 3C corresponds to the areas cl and c2 of Fig. 2
• Fig. 3D corresponds to the areas dl to d4 of Fig. 2.
• the modulating element controller 108 causes the phase modulating element 101 to perform modulation so that, for example, the wavefront aberrations illustrated in Figs. 3A to 3D are canceled with respect to the central angles of field of the respective areas 301.
• the phase modulating element 101 is caused to perform the modulation so as to generate a phase lag, and an attempt is made to make a difference in wavefront distribution on the pupil 103 become closer to 0.
• the wavefront aberration does not need to be completely 0, and as long as sufficient optical performance is maintained as the image pickup optical system, it poses no problem that there remains a certain wavefront aberration.
• the correction is performed until the wavefront aberrations illustrated in Figs. 3A to 3D become egual to or smaller than 20 mX.
• a control unit 107 Upon start of the image pickup, a control unit 107 refers to a lookup table (LUT) 104.
• LUT lookup table
• the phase modulating amount to be generated is determined according to the divided area.
• the phase modulating amount required for the area is extracted.
• the control unit 107 sends information on an area for which the reading is performed in a timesharing manner and on the phase modulating amount required for the area, to the modulating element controller 108 used for the phase modulating element 101 and the image pickup element controller 109 used for the image pickup element 102.
• the modulating element controller 108 and the image pickup element controller 109 control the phase modulating element 101 and the image pickup element 102, respectively. For example, at the time of reading the image information of the area a on the image pickup element 102, the modulating element controller 108 provides such a phase difference that can cancel the wavefront aberration at a angle of field of 0 degrees to the phase modulating element 101 in a time-sharing manner. In synchronization with this, the image pickup element controller 109 reads the image information only from the area a of the image pickup element 102.
• the modulating element controller 108 performs control so as to provide, to the phase modulating element 101, such a phase difference that can correct the wavefront aberration at the central angle of field of each of the areas.
• the image pickup element controller 109 which includes a separate reading unit, performs control so as to similarly perform the reading of the image information in a time-sharing manner at temporally
• phase difference to be provided to each area 301 by the phase modulating element 101 is determined based on data on a wavefront aberration
• the LUT 104 stores the wavefront aberration correcting amount
• aberration correcting amount may incorporate a correcting amount determined based on a focus position with respect to the optical system 105. Further, in this embodiment, the correction for the single-focal-length optical system is described. However, for example, in the case of a zoom lens, it is only necessary to incorporate the correcting amount determined based on each zoom position into the LOT 104, thereby changing the correcting amount for each focal length.
• able 1 is a table showing the angles of field of each area and the ranges of each area on the image pickup element 102.
• x represents a longitudinal direction of the screen
• y represents a direction perpendicular to x.
• the center of the screen (the optical axis in the case of a co-axial system) is assumed to be 0 degrees.
• the same coordinate directions are also used in embodiments
• the coordinate values of each area represent ratios obtained when an x-coordinate and a y-coordinate at a maximum angle of field on the image pickup element 102 are respectively assumed to be 1.
• Figs. 4A to 4D illustrate spot shapes at the central angles of field of the
• phase modulating element 101 is interposed at the position of the pupil 103 of the optical system 105, and the image pickup element 102 is divided into the
• the aberration correction can be any optical correction
• CMOS image pickup a CMOS image pickup
• CMOS image pickup element which performs reading on a pixel basis, rather than a CCD image pickup element, which performs line- reading.
• the second embodiment of the present invention is described.
• An optical system used in this embodiment is the same as in the first embodiment.
• components with the same reference symbols have the same functions, and thus description thereof is herein omitted.
• the image pickup element 102 is divided into nine areas having the same size.
• the wavefront aberration is larger on the periphery of the image pickup element (at a larger angle of field) , and accordingly, the wavefront aberration may significantly differ even within the same area.
• the wavefront aberration becomes the largest at about a middle angle of field of the screen and becomes smaller again as closer to the periphery thereof. Accordingly, if the wavefront aberration at the center of the area is adopted, the aberration conversely deteriorates on the periphery of the area, resulting in a deformed spot shape.
• the wavefront aberration be corrected with one area corresponding to one pixel.
• the image pickup takes a longer period of time, and an ultra-high modulation speed is required for the phase modulating element, and hence increasing the division number is not desired.
• the image pickup element 102 is divided into larger areas (sizes) in the vicinity of the center of the screen where the change amount in wavefront aberration is smaller, and into the same or smaller areas in a portion closer to the periphery of the screen.
• the diagonal angle of field of an area a is set to 0 to 32 degrees
• the diagonal angles of field of areas dl to d4 are set to 32 to 38 degrees
• the diagonal angles of field of areas il to i4 are set to 38 to 42 degrees.
• the screen needs to be divided into fifty or more areas.
• the number of divided areas can be reduced significantly, and also, the effect of improved optical performance can be
• the modulation speed of the phase modulating element 101 can be decreased.
• the phase modulating amount is determined so as to minimize the wavefront aberration at a point having such a wavefront aberration that is the same as or similar to the average value of the wavefront aberrations in the area.
• a point F3 of Fig. 7 corresponds to a beam in an optical axis direction.
• Table 2 shows the ranges of angle of field of each area and the ranges of each area on the image pickup element 102.
• Figs. 8 to 16 illustrate improved spot shapes and wavefront aberration shapes for the points Fl to F5 illustrated in Fig. 7, and the phase differences provided to the phase modulating element 101.
• Figs. 8 to 10 illustrate improved spot shapes and wavefront aberration shapes for the points Fl to F5 illustrated in Fig. 7, and the phase differences provided to the phase modulating element 101.
• Figs. 11 to 13 respectively illustrate the spots
• Figs. 14 to 16 respectively illustrate the spots, the wavefront aberrations and the phase modulating amounts of the area a. Improvements in spot shape and improvements in wavefront aberration amount can be
• the division number can be reduced, and the modulation speed of the phase modulating element can also be lowered.
• the following measure may be taken. That is, different exposure periods are used for the areas on the periphery of the screen and for the areas in the vicinity of the center of the screen, and the exposure period for the periphery of the screen is made longer, thereby increasing the peripheral light amount.
• phase modulating element 101 it is determined that the phase amount which is to be provided to the passing beam by the phase modulating element 101 based on the average of wavefront aberrations obtained when the stop is at full-aperture state. However, when the stop is changed, other modulating amounts optimal for respective stop values may be used.
• Fig. 17 is a main part schematic diagram of a third
• Fig. 17 is a main part schematic diagram in which the phase modulating element 101 is added to the zoom lens 1801 described in the first embodiment of PTL 5.
• Fig. 17 illustrate the wide- angle end, a middle zoom position (middle position) and the telephoto end, respectively.
• the respective control units of the control unit 107 and the like are omitted for the wide-angle end and the middle position (Middle) and are illustrated only for the telephoto end.
• the aspect ratio of the image pickup element 102 is set to 4:3.
• the zoom lens 1801 is a zoom lens having a zoom ratio of three with the focal length ranging from 5.6 mm to 16.8 mm, and the angle of field thereof changes from 32.2 degrees to 11.7 degrees in terms of the half angle of field.
• the number of divided areas is also changed in addition to the change amount of the phase modulating element 101.
• the phase amount is determined according to the zoom position and the position of the divided area. In this way, by changing the number of divided areas according to the zoom position, the correction of the wavefront aberration can be performed more efficiently.
• Such change data on the number of areas is also stored in the LUT 104, and hence the phase modulating amount which corresponds to each zoom position can be easily extracted. Further, in view of the fact that the present invention is directed to the image pickup system, it is desired that the shutter speed be made faster at the telephoto end to
• Table 3 and Table 4 show the ranges of angle of field angle of each area and the ranges of each area on the image pickup element 102 for the case of the wide-angle end and the case of the telephoto end, respectively. Further, with regard to representative areas in the case of the wide- angle end and in the case of the telephoto end, Figs. 20 to 34 illustrate the adopted phase modulating amounts and the spots and the wavefront aberrations before and after the phase modulation is adopted.
• Figs. 20 to 22 respectively illustrate the spots
• Figs. 23 to 25 respectively illustrate the spots, the wavefront
• weighting is performed on each position in the area of the image pickup element 102, thereby determining the phase modulating amount which is to be added to the phase modulating element 101.
• the weighting function is
• the weighting function is also stored in the LUT 104, and an appropriate weighting amount is applied
• the weighting function may differ depending on the area or depending on the zoom positio .
• the division number may be further changed at respective zoom positions between the wide-angle end and the telephoto end, thereby enabling the most effective division number to be selected for each focal length. Further, the phase modulating amounts
• a process up until image pickup in which data is read from the LUT 104, and the phase modulating element 101 is caused to perform the modulation.
• the phase modulating element 101 used in Fig. 36 is a phase modulating element of liquid crystal type described in the first embodiment.
• a current zoom position (focal length) of the zoom lens is obtained by a sensor 3702, and a table value indicating a focal length closest to the focal length stored in a memory 3701 is selected.
• the number of divided areas on the image pickup element 102 is determined, and the determined value is then sent to the image pickup element controller 109.
• the focus position and the stop value are detected by the sensor 3702 in the same manner, and a table value indicating a distance closest to the focus position stored in the memory 3701 is obtained, to thereby determine a phase modulating
• the sensor 3702 is denoted by the same reference
• control unit 107 calculates a voltage to be applied to transparent electrodes 202 of the phase modulating element 101. According to the determined voltage, the modulating element controller 108 applies the voltage to the
• the image pickup element controller 109 controls the image pickup element 102 so as to perform the reading only for an area used for the image pickup. Though an area which is not used for the image pickup receives light, data is not read from this area. After the image pickup is finished with one area, charges accumulated in the image pickup element 102 are once reset, and the image pickup element controller 109 performs control so as to start the reading from the next area again.
• the phase modulating element 101 can be caused to perform the modulation for each area on the image pickup element 102, and the acquisition of an image can be performed by synchronizing the phase modulation and the reading .
• Fig. 37 is an explanatory diagram for area division performed on the surface of an image pickup element according to a fourth embodiment of the present invention. ⁇ division method for area division performed on an image pickup element 102 of the fourth embodiment is described.
• the shapes of the divided areas of the image pickup element 102 are all rectangular.
• the shape of the divided area is not limited thereto.
• the division may be made as follows. That is, a large circular area 3801 is set at the center where the optical performance is excellent, and, around the area 3801, areas 3802 are set radially. By performing the area division in this manner, with respect to a rotationally-symmetric optical system, differences in correcting amount among the areas can be reduced. Further, divided areas are further made smaller like divided areas 3803 on the periphery of the screen, and hence such an optical system can be handled with more ease that the wavefront aberration steeply increases on the periphery of the screen.
• part of the optical system may be made decentered for the image stabilizing.
• decentering aberration occurs according to the decentering amount at the time of the image stabilizing for the camera shaking.
• an LUT can be created for the decentering amount and the decentering aberration, and the phase modulating element can be caused to perform
• favorable optical performance can be achieved by changing the correcting amount of the wavefront aberration according to the zoom position, the focus position and the like of the image pickup optical system, or changing the division number of areas of the image pickup element itself.
• the present invention can favorably deal with image pickup performed in a time-sharing manner, a change in number of divided areas and the like.

Landscapes

• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Multimedia (AREA)
• Signal Processing (AREA)
• Lenses (AREA)
• Lens Barrels (AREA)
• Studio Devices (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

ID=44798823

Family Applications (1)

Country Status (5)

Cited By (2)

Families Citing this family (2)

Citations (3)

Family Cites Families (22)

• 2010
  • 2010-04-16 JP JP2010094941A patent/JP5312393B2/ja not_active Expired - Fee Related
• 2011
  • 2011-04-12 WO PCT/JP2011/059477 patent/WO2011129459A1/en not_active Ceased
  • 2011-04-12 US US13/502,225 patent/US9118853B2/en not_active Expired - Fee Related
  • 2011-04-12 EP EP11768977.8A patent/EP2443820A4/en not_active Withdrawn
  • 2011-04-12 CN CN201180018990.6A patent/CN102972019B/zh not_active Expired - Fee Related

Patent Citations (3)

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events