Canon Patent: 18-90mm f/3.5-5.6, 18-135mm f/3.5-5.6, 30mm f/2.8 Lenses

Canon Patent
Image courtesy: egami

Egami (translated) spotted a new Canon patent. Three lenses are covered by the patent: 18-90mm f/3.5-5.6, 18-135mm f/3.5-5.6, 30mm f/2.8. The patent appears to refer to lenses that are resistant to temperature variation, i.e. that have consistent performance regardless of temperature variations .

Canon Patent
Image courtesy: egami
  • Patent Publication No. 2013-88736
    • Publication date 2013.5.13
    • Filing date 2011.10.21
  • Example 1
    • Zoom ratio 7.02
    • Focal length f = 18.60 – 130.50mm
    • Fno 3.59 -. 5.88
    • Half angle ω = 36.29 – 5.98 °
    • Image height 13.66mm
    • 187.48mm – 138.01 overall length of the lens
    • BF 35.60 – 70.79mm
    • Effective diameter of 58.92mm front lens
    • 16 pieces of 12-group lens configuration
    • One piece of one aspherical surface
    • One UD glass
    • 6-group zoom positive and negative negative positive positive
    • Inner Focus (Group 4)
  • Example 2
    • Zoom ratio 4.73
    • Focal length f = 18.60 – 87.97mm
    • Fno 3.59 -. 5.88
    • Half angle ω = 36.29 – 8.83 °
    • Image height 13.66mm
    • 164.98mm – 125.04 overall length of the lens
    • BF 35.60 – 69.29mm
    • Effective diameter of 61.54mm front lens
    • 13 pieces of 9 lens configuration
    • One piece of one aspherical surface
    • 4-group zoom positive and negative positive positive
    • Inner Focus (the second group)
  • Example 3
    • Focal length f = 29.48mm
    • Fno. 2.92
    • Half angle ω = 24.86 °
    • Image height 13.66mm
    • The overall length of the lens 78.43mm
    • BF 35.40mm
    • Effective diameter of 22.43mm front lens
    • 10 pieces of 8 lens configuration
    • One piece of one aspherical surface
  • Resin lens
    • Vulnerable to temperature change
    • There are restrictions on the type of coating, ghost and flare cause of
  • Canon patent
    • The final lens group is arranged a resin lens having a concave surface facing the image side, and place the glass lens on the image side
    • Weaken the power of the resin lens, I reduce the performance variation due to temperature change
    • Incident light axial rays is arranged in a low position of the resin lens, to suppress the influence of the birefringence variation of the resin lens
    • Likely to occur in the concave surface of the resin lens ghost is avoided by optimization of the power of the air lens in the shape of the glass lens and resin lens, in the meantime

Canon Patent: Image Stabilized Lens For Astro-Photography

Canon Patent

Egami (translated) spotted a Canon patent concerning an image stabilized lens for astro-photography. The lens is able to automatically track objects (stars etc). Canon has a DSLR suited for astro-photography, the EOS 60Da (price & specs). Such a lens obviously needs a camera that supports it. That means GPS, levelling, and a powerful CPU.

  • Patent Publication No. 2013-77910
    • Publication date 2013.4.25
    • Filing date 2011.9.29
  • Canon patent
    • In the lens anti-vibration mechanism from etc., let me change the direction of the optical axis
    • From the GPS, etc., I ask the coordinates and altitude
    • Detects the inclination of the posture from the electronic level, etc., to determine the direction of the optical axis
    • Calculate the speed and direction of movement of celestial angle of view, and controls the lens according to the calculation result

Canon Files Patent For High-Res Images Obtained By Pixel Shift


Image courtesy: Egami

Egami (translated) spotted a patent filed by Canon that appears to be for high resolution pictures that are obtained by combining different shots. Basically a continuous shooting situation where you build a final image based on the images that have been shot. Motion could obviously be a big problem.

  • Patent Publication No. 2013-74337
    • Publication date 2013.4.22
    • Filing date 2011.9.26
  • If there is misalignment of the sub-pixels, it can obtain a high resolution image from a low resolution image
  • Canon patent
    • By continuous shooting and combining pixel shift, I get a high-resolution image
    • Method of pixel shift, lens and image sensor shift of
    • By setting appropriately the displacement amount corresponding to the super-resolution magnification optimization


Rumor & Patent: Canon Working On New Tilt-Shift Lenses?




Just recently a rumor about new Canon tilt-shift lenses surfaced. 45mm and 90mm are possible candidates for a replacement. The new tilt-shifts could be announced at the end of 2013 and be released in early 2014.

Egami (translated) spotted a patent that fits well with the rumor above. It is not directly related to lens engineering, it considers a method to change the angle of the grid lines in the EVF and in live view mode depending by the amount of tilt that was set.

  • Patent Publication No. 2013-81129
    • Publication date 2013.5.2
    • Filing date 2011.10.5
  • Shooting assist functions suitable for tilt lens
  • I rotate display grid lines
    • The angle information of the tilt lens to determine the angle of the grid lines
    • To align in the direction of change of focus, the angle of the grating lines, easy to compose the picture

Canon Patent For 400mm f/4 DO Lens

Canon Patent

Canon Patent

Egami (translated) spotted another patent filed by Canon. It is for a 400mm f/4 lens with diffractive optical elements (to reduce flare).

Patent description (machine translated):

  • Patent Publication No. 2013-64858
    • 2013.4.11 Release Date
    • Filing date 2011.9.16
  • Example 1
    • Focal length f = 392.12mm
    • Fno. 4.12
    • Half angle of ω = 3.16 °
    • Image height Y = 21.64mm
    • 262.14mm length lens
    • BF 69.97mm
    • Two fluorite
  • Materials and anomalous partial dispersion DOE to use, reduce the chromatic aberration
  • Refractive power of the diffractive surface
    • Strong, but can reduce the chromatic aberration of the element itself, flare increases
    • The weaker, other optical element DOE play a role
  • Refractive optical unit
    • DOE anomalous partial dispersion and bonding materials
    • DOE aspherical surface on the opposite side of the
  • Vibration control
  • Inner Focus
[via Egami]

Canon Files Patent For New Primes (45mm, 50mm, 60mm)

50mm f/1.4
50mm f/1.2

Egami spotted another patent filed by Canon. The patent refers to s 50 mm F1.4 , 50 mm F1.2 , 45mm F1.6 and 60 mm F1.8 lenses, and describes an apochromatic design that aims to reduce chromatic aberration.

Patent description (machine translated):

  • Patent Publication No. 2013-57802
    • 2013.3.28 Release Date
    • 2011.9.8 filing date
  • Example
    Focal length Fno. Angle of view Focus
    One 51.7 1.45 45.4 Floating rear focusing +
    Two 51.7 1.45 45.4 Fed whole
    Three 51.7 1.25 45.4 Floating rear focusing +
    Four 51.7 1.25 45.4 Fed whole
    Five 45.0 1.6 51.4 Fed whole
    Six 60.0 1.85 39.7 Fed whole
  • In many large-diameter Gaussian secondary spectrum of axial chromatic aberration
    • This problem occurs when using glass and others with the same Abbe number, a lens that is different partial dispersion ratio
    • When used in a positive lens lanthanum flint glass small partial dispersion ratio
    • When used in a negative lens of flint glass titanium large partial dispersion ratio
  • Canon patent
    • Using a lens with a partial dispersion ratio appropriate correcting the axial chromatic aberration secondary spectrum
    • The concave lens surface adjacent to the aperture, coma aberration correction, the sagittal flare
[via egami]