Canon patent to avoid AF hunting through improved detection of AF errors

AF hunting

Canon patent for a method to avoid Auto-Focus hunting by improving the detection of AF errors. If I got it right, this is achieved by using a linear polarizer between the optics and the imaging sensor (any help appreciated). This should improve the detection of inconsistent AF measurements and hence reduce if not drop the so called “AF hunting”. According to the machine-translated patent literature, this is…

a technology that can detect the displacement direction and amount of focus without having to drive the focus group.

 

  • Patent Publication No. 2016-24391
    • Published 2016.2.8
    • Filing date 2014.7.23
  • Example 1
    • Zoom ratio 1.00
    • Focal length 293.46
    • F-number 2.93
    • Half angle of view (degrees) 4.22
    • Image height 21.63
    • Overall length of the lens 274.0
    • BF 59.13
  • Canon patent
    • When placed near squeezed retarder phase difference changes toward the periphery from the center, and a linearly polarized light having a vertical plane of vibration, the focus position of the direct polarized light having a horizontal oscillation plane deviates
    • Place the linear polarizer between the optical system and the imaging device, and polarization selection means
[via Egami]

 

Yet another Canon patent for the EOS M system, it’s an EF-M 16-50mm f/3.5-5.6 IS STM

EF-M 16-50mm f/3.5-5.6 IS STM

It appears Canon is filing one patent for EF-M lenses after the other. Here is another one for an EF-M 16-50mm f/3.5-5.6 IS STM lens.

I can’t say if this optical formula has something to do with the already available EF-M 15-45mm f/3.5-6.3 IS STM lens. Maybe it was a patent obn the road to the 15-45mm. However, Canon appears to be definitely commited to the EOS M system.

  • Patent Publication No. 2016-118658
    • Published 2016.6.30
    • Filing date 2014.12.22
  • Example
    • Zoom ratio 2.88
    • Focal length 16.51 21.00 47.49
    • F-number 3.49 3.77 5.80
    • Half angle of view (degrees) 39.61 33.04 16.05
    • Image height 13.66 13.66 13.66
    • Overall length of the lens 82.00 77.35 84.14
    • BF 10.70 10.70 13.31
[via Egami]

Canon patent for 28-500mm F2.8-4 zoom lens (for Powershot 1″ sensor series?)

28-500mm F2.8-4

Canon patent for an optical formula that appears to be for a 1″ sensor, and for a 28-500mm F2.8-4 lens. Canon makes Powershot cameras with an 1″ sensor, the patent may point to a future super-zoom Powershot camera.

  • Patent Publication No. 2016-99548
    • Published 2016.5.30
    • Filing date 2014.11.25
  • Example 1
    • Zoom ratio 17.50
    • Focal length 9.76 104.00 170.79
    • F-number 2.88 3.77 3.90
    • Half angle of view (degrees) 36.48 4.51 2.75
    • The image height 7.22 8.20 8.20
    • The total lens length 196.17 196.17 196.17
    • BF 7.33 7.33 7.33
[via Egami]

Canon EF 70-200mm F2.8 DO in the works, patent suggests

70-200mm F2.8 DO

A Canon patent for a 70-200mm F2.8 DO (Diffractive Optics) lens. The patent was spotted by Egami, and they suggest this lens could hit the market before 2020, as replacement for the Canon EF 70-200 F2.8L IS.

It’s also suggested that this lens is 8K ready, i.e. ready to work with an 8K DSLR.

  • Patent Publication No. 2016-80877
    • Published 2016.5.16
    • Filing date 2014.10.17
  • Example 1
    • Zoom ratio 2.69
    • Focal length 72.15 134.00 193.98
    • F-number 2.91 2.91 2.91
    • Angle of view 16.69 9.17 6.36
    • Image height 21.64
    • The total lens length 223.50 223.50 223.50
    • BF 45.35 45.35 45.35
  • [0006] Conventional full high definition (number of pixels 1920 × 1080, pixel size number .mu.m) If image quality equivalent was sufficient in the conventional example as described in patent documents mentioned above. However, Super Hi-Vision (the number of pixels 8000 × 4000, pixel size 1μm before and after) for the future sought image quality, such as, is not sufficient in the imaging performance of conventional zoom lens. Therefore, further improvement of performance (in particular, reduction of the chromatic aberration amount) is required.
  • Canon patent
    • DOE ( diffractive optical element )
    • Inner zoom (Examples 2 and 3)
    • Inner focus
    • Floating (Examples 1, 4)
[via Egami]

Canon patent for 11mm F4L USM lens

11mm

This could be a very cool lens, if the optical formula described in this Canon patent will ever go into production. Canon filed a patent for a 11mm F4L USM lens. The optical formula appears to refer to a relatively small lens with good control of optical distortions.

  • Patent Publication No. 2016-81005
    • Published 2016.5.16
    • Filing date 2014.10.22
  • Example
    • Focal length 11.33 11.47
    • F-number 4.11 4.12
    • Half angle of 62.36 62.08
    • Image height 21.64 21.64
    • Overall length of the lens 109.13 109.12
    • BF 38.90 38.40
  • [0003]However, even in the little lens distortion, by the emphasis of perspective, it may appear to be distorted photographic image. Furthermore, suitable amount of distortion varies depending on the subject and the composition to be photographed. For this reason, it is required that the distortion in the variable.
  • Canon patent
    • It is less distortion in the normal state
    • A large distortion in the distortion change state
[via Egami]

Canon patent for 30mm F2.8 DO lens for full-frame mirrorless cameras

30mm

Another Canon patent for an optical formula that appears to point to a full-frame mirrorless camera, a 30mm F2.8 DO lens. “DO” stays for diffractive optics. I tell you folks, Canon’s full-frame mirrorless camera is coming!

  • Patent Publication No. 2016-102851
    • Published 2016.6.2
    • Filing date 2014.11.27
  • Example
    • Zoom ratio 1.00
    • Focal length 31.35
    • F-number 2.86
    • Angle of view 34.61
    • Image height 21.64
    • Overall length of the lens 85.29
    • BF 29.99
  • Canon patent
    • Positive ShiboTadashi
    • Diffractive optical element (the second group of aperture stop image side)
    • Correct axial chromatic aberration and lateral chromatic aberration of the near-infrared light
  • [0001] The present invention relates to a magnification chromatic aberration correction of the imaging optical system used in a near infrared region from the visible region is suitable especially monitoring optical system.
[via Egami]