New patent describes a super compact OVF (for small DSLR or mirrorless?)

The latest patent spotted by Egami (translation here) describes a Canon developed Optical Viewfinder with 100% field of view. The special thing about that patent is that the viewfinder is a lot smaller than current finders. It sounds like a perfect solution for a new super small Canon DSLR or a future Mirrorless camera with Optical or Hybrid viewfinder. Otherwise…why do it that small?

Canon Files Patent For Two 4/3 Lenses (14-28mm f/1.4-2.4 and 12-28mm f/2-3.2)

Canon Files Patent For Two 4/3 Lens
14-28mm f/1.4-2.4
Canon Files Patent For Two 4/3 Lens
12-28mm f/2-3.2

This came as a surprise. Could this mean Canon is working on a new version of the Powershot G1X? looks like.

Japanese blog Egami (translated) spotted a patent for two lenses with a 4/3 ratio. A 14-28mm f/1.4-2.4 and a 12-28mm f/2-3.2. I don't know what to think about that. The machine translated text is difficult to understand. If someone here can help with the interpretation, he or she is welcome. Any Japanese reader willing to help? :-) Quoting Egami:

Canon 28mm F1.8-2.8 is fourteen-28mm, 12- F2-3.2 ,14-28mm F1.4-2.4 of the patent is pending. 4/3 ” imaging element of becoming a zoom lens equivalent to 24-56mm. 4/3 corresponds to, or the 28-56mm, equivalent size 35mm ” imaging element while using, Myu4 / 3 lens without correspond to and if integrated, can realize the camera is so superior balance of performance, size.

  • Patent Publication No. 2012-226042
    • Release Date 2012.11.15
    • Filing date 2011.4.18
  • Example 1
    • Zoom ratio 2.37
    • 33.60 – – 28.74mm f = 14.20 focal length
    • Fno = 1.80 -. 3.30 – 2.93
    • Half angle of view ω = 37.13 – 17.74 – 20.51deg.
    • Image height 10.75mm
    • 77.74 – – 75.24mm 77.26 overall length of the lens
    • BF 1.46mm
    • 11 sheets in 10 groups lens configuration
    • Three four-sided aspherical
  • Example 3
    • Zoom ratio 2.72
    • 33.60 – – 28.53mm f = 12.36 focal length
    • Fno = 2.06 -. 3.60 – 3.26
    • Half angle of view ω = 41.01 – 17.74 – 20.65deg.
    • Image height 10.75mm
    • 82.29 – – 79.22mm 82.03 overall length of the lens
    • BF 1.21mm
    • Eight 8 groups lens configuration
    • Four aspherical surface 7
  • Example 4
    • Zoom ratio 2.37
    • 33.60 – – 28.74mm f = 14.20 focal length
    • Fno = 1.40 -. 2.71 – 2.39
    • Half angle of view ω = 37.13 – 17.74 – 20.51deg.
    • Image height 10.75mm
    • 80.53 – – 77.94mm 79.63 overall length of the lens
    • BF 1.51mm
    • 10 sheets of 9 groups lens configuration
    • Three four-sided aspherical

[via Egami]

 

Canon Patent To Improve Hybrid Auto-Focus Speed

Hopefully this leads to quicker hybrid AF. Canon filed a patent that aims at improving the speed of hybrid (phase and contrast detection) AF systems, particularly when tracking subjects. The patent’s abstract:

A camera to which a lens unit is exchangeably attached includes a phase difference detection type focus detection unit, a contrast detection type focus detection unit, and a processor configured to acquire correction information used to correct a shift amount between a focus detecting light flux and an image-pickup light flux from the image pickup lens. The contrast detection type focus detection unit performs scanning in a single direction from a focus position detected by the phase difference detection type focus detection unit, the single direction being set based on the correction information.

The patent tackles the following technical problem:

Since the [contrast detection focus method] has an excellent focus detection precision but requires a long time for focusing, the [contrast detection focus method] cannot be applied when an allowable time period required for the focus detection is short, in particular, in following a moving body or at the consecutive shooting time.

This is done in the following way:

A camera according to the present invention is a camera to which a lens unit is exchangeably attached. The lens unit includes an image pickup lens configured to form an object image, and is compatible with a first focus detection unit configured to provide a focus detection by detecting a phase difference between a pair of object images formed by utilizing a first pupil splitting unit. The camera includes a second focus detection unit configured to provide a focus detection by detecting a phase difference between a pair of object images formed by utilizing a second pupil splitting unit different from the first pupil splitting unit, a third focus detection unit configured to provide a focus detection by detecting a peak position of a contrast of the object image by performing scanning that changes a distance between an image pickup device and a focus position formed by the image pickup lens, and an acquisition unit configured to acquire correction information used to correct a shift amount between a focus detecting light flux and an image-pickup light flux from the image pickup lens. The third focus detection unit performs the scanning in a single direction from a focus position detected by the second focus detection unit, the single direction being set based on the correction information.

Good to know that Canon is working hard on a better hybrid Af system. :-)

Canon Patent To Improve Hybrid Auto-Focus Speed

[via freepatentsonline]

Canon Files Another Patent For Phase Detection Auto-Focus

Canon Files Another Patent For Phase Detection Auto-Focus

I reported about two similar patents filed by Canon in the past (here and here). Now Canon files another patent for phase detection Auto-Focus, explicitly referring to phase-detection AF for a camera with “removable lenses”.

The present invention has been made in view of the above-described problems, and provides an image- pickup apparatus in which a focus detecting pixel is arranged in a part of an image sensor to perform focus detection based on the phase difference detection method. With this arrangement, it is possible to reduce the frequency of lens driving upon focusing while preventing a hunting phenomenon upon focusing.

The image-pickup apparatus according to a first aspect of the present invention capable of mounting a removable lens unit with an image-pickup optical system including a focus lens thereon,

comprises: an image sensor in which an image-pickup pixel to receive a light beam passed through an exit pupil of the image-pickup optical system and a focus detecting pixel to receive a light beam passed through the exit pupil, partially shielded, of the image-pickup optical system are arrayed; focus detection means for detecting a shift amount of the focus lens from a focus position based on a phase difference in an output signal from the focus detecting pixel; and acquisition means for acquiring ray vignetting information of the image-pickup optical system, wherein, when a position detection resolution of the focus lens is lower than a drive resolution of the focus lens, the focus detection means detects the shift amount of the focus lens from the focus position using the ray vignetting information in a predetermined position of the focus lens specified based on information from the lens unit.

Could this be the patent for a new method to get phase-detection AF? Maybe it is for Canon’s next, pro-oriented mirrorless camera.

[via freepatentsonline]

[Patent] Canon Files Patent For 14mm f/2.8 Lens (better coating, low refractive index)

14mm f/2.8

Egami (translated) spotted another patent filed by Canon. This time it is for a 14mm f/2.8 lens with improved coating (tubular coating):

It seems it is possible to realize a low-refractive-index low reflectivity by the structure below the diffraction limit, even without the uneven surface of the coating. 14mm F2.8 is what I want you to adopt all means patent coating of the lens as the front lens is large, yet is protruding.

Cross-sectional view
  • Patent Publication No. 2012-159723
    • 2012.8.23 Release Date
    • 2011.2.1 filing date
  • Example 1
    • F = 14.3mm focal length
    • Fno. = 2.89
    • Half angle ω = 56.6 °
    • 14 images in 10 groups lens configuration
  • Existing coating roughness
    • In daily use, dirt or dust may adhere, could not wipe, sex or bad Mentenasu productivity and manufacturing process
  • Canon patent
    • (Coating applied to one surface of a lens) thin film layer
    • Having a plurality of tubular spaces are arranged parallel to the tube
    • Maximum opening diameter of the tubular space below 400nm
    • The inorganic oxide materials (silica, titania)
[via Egami]

Canon Files Patent For 28-300mm and 28-135mm lens (reduced chromatic aberrations)

28-300mm f/3.5-5.6
28-135mm f/4-5.6

Next two Canon patents! As usual spotted by Japanese site Egami (translated) This time for a 28-135mm f/4-5.6 and a 28-300mm f/3.5-5.6 lens.The patent is about reducing chromatic aberrations.

  • Patent Publication No. 2012-163746
    • 2012.8.30 Release Date
    • 2011.2.7 filing date
  • Example 4
    • Zoom ratio 4.67
    • 56.11 – – 131.85mm f = 28.21 focal length
    • Fno 4.12 -. 4.89 – 5.77
    • Half angle of view ω = 37.48 – 21.09 – 9.32deg.
    • Image height 21.64mm
    • 242.67 – – 266.43mm 224.00 overall length of the lens
    • BF 55.79 – 70.40 – 82.95mm
    • 20 sheets of 14 group lens configuration
    • Two two-sided aspherical
    • Three low-dispersion glass
    • Four Super UD glass
    • 102.40mm effective diameter of the first surface
    • 5-group zoom negative positive negative
  • Example 5
    • Zoom ratio 10.31
    • 93.64 – – 307.06mm f = 29.77 focal length
    • Fno 3.31 -. 4.71 – 5.85
    • Half angle of view ω = 36.00 – 13.01 – 4.03deg.
    • Image height 21.64mm
    • 263.66 – – 304.01mm 209.34 overall length of the lens
    • BF 61.72 – 89.40 – 106.84mm
    • 18 sheets 12 groups lens configuration
    • Three 3 aspherical surface
    • Three low-dispersion glass
    • 2 UD glass sheets
    • 84.36mm effective diameter of the first surface
    • 5-group zoom negative positive negative
  • In the zoom lens of the positive lead type, reducing the chromatic aberration of magnification of the secondary

More graphs after the break

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