Egami (translated) spotted a patent filed by Canon that could point to the next iteration of the EF 300mm f/4L IS lens (announced 2004). A 50mm and 24mm lens are also mentioned. If I got it right these lenses are also featuring optimised refractive index distribution.

The lenses described in the patent feature an optical unit with an optimised refractive index distribution over the lens’ optics. The described optical system consists of a first lens unit with positive refracting power, a second lens unit with negative refracting power, and a third lens unit that has positive refracting power. The aforementioned refractive-index-distribution element is arranged at the first lens unit. Such an optical system should be able to reduce various optical aberrations like chromatic aberrations.

• Patent Publication No. 2015-28551
  • Published 2015.2.12
  • Filing date 2013.7.30
• Example
  

  embodiment

  Example	Focal distance	Fno.	Half angle	Image height	Overall length of the lens	BF
  One	294.00	4.14	4.21	21.64	239.07	83.42
  Two	24.48	2.86	41.47	21.64	92.00	38.00
  Three	51.70	1.30	22.71	21.64	94.01	37.50
  Four	294.00	4.14	4.21	21.64	240.00	82.95
  Five	6.15 20.45 71.28	2.88 3.71 3.69	30.34 9.98 2.89	3.60	84.11 86.12 90.41	11.74 15.68 8.50
  Six	293.97	4.14	4.21	21.64	239.98	85.34

• Canon patent
  • The use of refractive index distribution element

EF 300mm f/4L IS 

 

[via Egami]

Egami (translated) spotted a patent filed by Canon for an external image stabilisation unit. The unit is placed between the camera body and the lens, just like you would do with a teleconverter. Cool invention!

The present invention, users vibration reduction function or lighter or selectable according to the application, in addition to being used as an optical system having a vibration reduction converter, an optical system having a vibration reduction function, a vibration reduction function can also be used as a commercial advantage that the two systems can be Heibai by diverting a large portion of the component with no lightweight optics.

• Patent Publication No. 2015-28555
  • Published 2015.2.12
  • Filing date 2013.7.30
• Example 1a (master lens only)
  • Focal length 392.50
  • F-number 2.92
  • Half angle of 3.16
  • Image height 21.64
  • Overall length of the lens 379.64
  • BF 41.57
  • Effective diameter of the front lens 135.72mm
  • Lens configuration 8 groups nine
• Example 1b (anti-vibration converter mounted state)
  • Focal length 392.50
  • F-number 2.92
  • Half angle of 3.16
  • Image height 21.64
  • Overall length of the lens 379.64
  • BF 41.56
  • Effective diameter of the front lens 135.72mm
  • Lens construction 12 groups 15 sheets
• Canon patent
  • 3-group configuration of positive and negative positive
  • Inner focus (the second group)
  • The anti-vibration converter can be inserted on the object side of the third group

Egami (translated) spotted a patent filed by Canon that appears to refer to a new auto-focus technology to implement in mirrorless cameras and in cameras with a translucent mirror (like the Sony A99).

• Patent Publication No. 2015-22264
  • Published 2015.2.2
  • Filing date 2013.7.23
• Canon patent
  • Phase difference detection method to be received by the AF sensor can be reflected incident light from the imaging lens
  • The phase difference detection by the image plane phase difference AF
  • The phase difference detection by external light AF sensor

 

Egami (translated) spotted a patent for a DSLR mount made of metal and resin. The metal part is the “inner part” of the mount, the “resin part” the outer part. The advantages are lower weight and lower abrasion. Another advantage could consist in smoother mounting/unmounting of lenses, with less abrasion of the lens-side part of the mount, since high quality resin is more abrasion resistent than metal. Be aware that when talking about resins we are not talking about mere plastic.

• Canon patent
  • Of bayonet mechanism mount
  • Mounting an inner peripheral portion of the body has a concave rail surfaces of metal
  • Mount the outer periphery of having a rail surface of the convex shape in the resin
  • That resin rail than the metal rail, I have a narrow width and high height

More from the machine translated patent description:

If a metallic material is used for the construction material of camera mount, the strength of mount will be secured, but if attachment and detachment of a taking lens (lens device) are repeated, a mount surface will be worn out and appearance grace will be spoiled by the abrasion. Wear becomes a cause, the slidability of a mount surface is deteriorated, attachment-and-detachment torque becomes high, and an operation feeling becomes less good. In order to secure the abrasion resistance of mount, and slidability, when a resin material is used as construction material of the whole mount, as compared with the case where a metallic material is used, strength is weak.

and

In order to compensate the characteristic of a metallic material and resin mutually, the mount which molded metal and resin integrally is proposed. The Patent[shows a] mount of composition of having the mount main part which constituted the mount surface from a synthetic resin excellent in abrasion resistance and a sliding feel, and a metal ring component for reinforcing this mount main part.

[via Egami]

Egami (translated) spotted another patent filed by Canon.

The patent refers to a technique for the generation of sharp images without star trails when taking photos of the night sky with long exposures. The purpose is to generate an image where a landscape and a star are made bright and a track of the star is prevented from appearing when a star and landscape photograph is taken.

How does this work? A first detection process concerns the landscape in the test image, first detection data is produced. A second detection process detects the star from the test image in accordance with the first detection data and obtains second detection data. The exposure condition setting section obtains a first image by the imaging section with a first exposure condition which is set in accordance with the first detection data, controls the imaging section with a second exposure condition which is set in accordance with the second detection data, and obtains a second image. A first synthesis corrects a luminance value of the star to a prescribed luminance value in the second image data, and sets it to be a first synthesized image. A second synthesis synthesizes the first synthesized image and the first image, and generates a second synthesized image.

Canon patent

• Low sensitivity, I will test taken at the proper exposure
• Place the time, to test shooting with the same settings
• From the difference of the two test images to detect a movement of the star, and also to calculate the proper exposure time from the mobile width
• The production shot with appropriate exposure to the subject of non-star
• The production shot with appropriate exposure to star
• To obtain the final output image by synthesizing two images production

[via Egami]