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April 1, 2015
Posted in Patents

Canon Patent for new automatic Vignette Correction Processing Algorithm

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2015_56709_fig04b

Egami (translated) spotted a patent filed by Canon for an image processing algorithm that corrects lens vignetting by varying the exposure time according to the image height, i.e. applying different exposure times to different spots in the image area.

One thing to note, in my opinion: this patent implicitly also refers to a new sensor tech. Some excerpts from the patent description:

The present invention relates to the control method of the imaging device which has an image sensor in which exposure control is possible for every region, and the Method of amendment of an image.

In the imaging device which photos an object by acquiring an optical image via a lens, in the image of the photoed object, what is called a light-falloff-at-edges phenomenon in which light volume is deteriorated occurs as it goes to an image periphery from the central part of the image.

It is known that a light-falloff-at-edges phenomenon will be decided by the relation of the characteristic of the lens with which an imaging device is provided, and the characteristic of a solid state image pickup device. Specifically, it is a relation with the position of the solid state image pickup device to an effective image circle (region where light hits uniformly), and the amount of light falloff at edges is decided uniquely. However, it will be the requisite that the effective pixel center of a solid state image pickup device and the optical axis center of a lens are corresponding in this case. It is dependent also on the f-stop of a lens, and the amount of light falloff at edges has an omission condition of light volume remarkable in the opening and small diaphragm side. In the opening side, although the incident light in a lens center enters as a general lens characteristic with circular light flux, since the incident light in the corner of a lens always passes along the corner, light will be kicked, incident light becomes the light flux of elliptic form, and light volume is deteriorated.

  • Patent Publication No. 2015-56709
    • Published 2015.3.23
    • Filing date 2013.9.11
  • Patents
    • I varying the exposure time for each area
      • The exposure start falling apart, batch read
      • At the same time in the start of exposure, read apart
    • I lengthen the peripheral of exposure time

What do you think?

March 9, 2015
Posted in Patents

Canon Patent for 100x Zoom Compact Camera (24-2400mm equivalent)

2014_174524_fig07

Will this patent (spotted by Egami) ever hit the market? If it does it will probably yield a new Powershot camera with a wobbling 100x zoom. The patent refers to a 1/2.3″ sensor and an equivalent focal length of 24-2400mm.

  • Patent Publication No. 2014-174524
    • Published 2014.9.22
    • Filing date 2013.3.13
  • Example 4
    • Zoom ratio 98.52
    • The focal length f = 3.07 53.41 302.40mm
    • Fno. 1.85 8.14 9.00
    • Half angle ω = 36.2 2.40 0.50 °
    • Overall length of the lens 110.05mm
    • BF 12.67 27.40 5.19mm
    • 4-group zoom of positive and negative, positive
    • Inner zoom (the second group, the third group)
    • Rear focus (fourth group)
    • Anti-vibration (third group)

Do you think Canon will produce a Powershot with a 100x zoom anytime soon?

March 5, 2015
Posted in Patents

Canon Patent for 12-32mm T3.5 and a 15-47mm T2.8 Cinema Lenses

pat

Egami (translated) spotted a patent for two Cinema lenses, a 12-32mm T3.5 and a 15-47mm T2.8 lens.

  • Patent Publication No. 2015-34858
    • Published 2015.2.19
    • Filing date 2013.8.8
  • Example 1
    • Zoom ratio 2.50
    • The focal length f = 12.50 18.75 31.25mm
    • Fno. 3.50
    • Half angle ω = 51.21 39.67 26.45 °
    • Image height Y = 15.5mm
    • Overall length of the lens 193.59
    • BF 42.84
  • Example 2
    • Zoom ratio 2.81
    • Focal length 16.00 26.88 45.00
    • Fno. 2.80
    • Half angle of 44.18 30.05 19.06
    • Image height Y = 15.5mm
    • Overall length of the lens 247.38
    • BF 43.27
  • Canon patent
    • Negative positive and negative positive 4-group zoom
    • Inner zoom (the second group)
    • Inner focus (rear group of the first group)
February 27, 2015
Posted in Patents

Canon Patent for 9-18mm Ultra-Wide Angle Lens for EOS M

9.18

Egami (translated) spotted a patent for an EF-M 9-18mm f/3.5-4.5 STM lens for the EOS M system. A bit weird since there is already the excellent EF-M 11-22mm f/4-5.6 IS STM lens. I guess this is just one of the many patents Canon is filing and not a lens that will hit the market anytime soon.

  • Patent Publication No. 2015-34892
    • Published 2015.2.19
    • Filing date 2013.8.9
  • Example 1
    • Zoom ratio 1.90
    • The focal length f = 9.22 14.67 17.50mm
    • Fno. 3.45 4.02 4.63
    • Half angle ω = 55.92 42.90 37.92 °
    • Image height Y = 13.63mm
    • Overall length of the lens 94.76 85.16 91.16mm
    • BF 13.06 15.35 13.60mm
    • Negative positive and negative positive 4-group zoom
    • Inner Focus (third group)
    • Video support
February 25, 2015
Posted in Patents

Canon Patent for Foveon Style Multilayer AF Sensor

pat

Egami (translated) spotted a patent for a new AF sensor. The patent describes a Foveon-like, multilayer sensor:

Patent Publication No. 2015-37217

  • Published 2015.2.23
  • Filing date 2013.8.12

Canon patent

  • AF sensor
  • In the depth direction, I comprises a first layer, the second layer, the photoelectric conversion portion of the third layer
  • The second layer is for monitoring, detecting the amount of light that is received in real-time, to control the accumulation time
  • The third layer in a bright environment, the dark environment so that the use of the first layer, sensitivity can be switched
  • Furthermore, in a dark environment is used by adding the first and third layers
February 24, 2015
Posted in Patents

Canon Patent for EF-EF-M Adapter with Improved Auto-Focus Speed

2015_34903_fig01

Egami (translated) spotted what could be Canon’s best move to push their mirrorless cameras. A new EF-EF-M adapter that should deliver better AF speed when using EF and EF-S lenses. While the AF performance of Canon’s new EOS M3 is excellent with the native EF-M lenses, AF performance is limited when using EF lenses via the currently available adapter. If Canon puts such an adapter on the market it would a huge selling point for the EOS M3. Access to Canon’s extended lens lune-up, and same AF performance as with native lenses!

Machine translated patent description:

  • Patent Publication No. 2015-34903
    • Published 2015.2.19
    • Filing date 2013.8.9
  • Master lens
    • Zoom ratio 2.69
    • Focal length 72.13 135.02 193.99mm
    • Fno. 2.90
    • Half angle ω = 10.72 5.78 4.03 °
    • Image height Y = 13.66mm
    • Overall length of the lens 237.36mm
    • BF 54.00mm
  • Adapter installed
    • Zoom ratio 2.69
    • The focal length f = 72.12 135.00 193.96mm
    • Fno. 2.90
    • Half angle ω = 10.72 5.78 4.03 °
    • Image height Y = 13.66mm
    • Overall length of the lens 239.70mm
    • BF 16.77mm
  • Canon patent
    • Fast AF adapter
    • Wobbling corresponding
    • 3-group configuration of positive and negative positive
    • 2 group also serves as a focus group and the anti-vibration group
    • And realize high-speed AF focus group was lighter
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