Canon Patent: RF 28-70mm f/2.8L That Does Not Extend, Inner Focusing

Canon Patent

Here is a very interesting Canon patent application, once more for an RF mount lens. An RF 28-70mm f/2.8L with inner focusing and that does not extend might be in the works.

The Canon patent application spotted by asobinet.com (they did not disclose the patent number), discusses optical formulas for a RF 28-70mm f/2.8L lens. The interesting part, if I got it right from the machine translated Japanese text, is that the lens not only does all the focusing but also employs a design that is usually found on wide-angle lenses.

It sounds like a patent for a small and lightweight standard zoom. The characteristic of this optical system is that the total length is the longest at the wide-angle end and the total length becomes shorter toward the telephoto end. This is a common optical system for wide-angle lenses, but I don’t see this type of lens with standard zoom lenses, especially with large-aperture zoom lenses. If it is really put into practical use, it will be a very portable lens.

Did I get it right? The lens is indeed described to be shorter at the telephoto end (emphasis mine) in both embodiment:

  • Wide-angle intermediate telephoto
  • Focal length 28.84 36.81 67.90
  • F number 2.91 2.91 2.91
  • Half angle of view (°) 32.68 29.23 17.67
  • Image height 18.50 20.60 21.64
  • Lens total length 117.09 109.31 101.58
  • BF 9.99 13.47 21.59
  • Focal length 28.84 37.17 67.90
  • F number 2.91 2.91 2.91
  • Half angle of view (°) 32.65 28.90 17.67
  • Image height 21.64 21.64 21.64
  • Lens total length 132.62 122.81 111.18
  • BF 21.92 26.79 39.84

Moreover, the lens uses a floating focus structure to achieve autofocus. That means it might have very fast and and highly responsive AF. The patent literature is very clear in what should be achieved:

PROBLEM TO BE SOLVED: To provide a zoom lens having a short overall lens length, being compact and lightweight, and having high optical performance.

All comments welcome.

More Canon patent applications are listed here. Some particularly interesting patent applications we think might get into production are these:

Canon Patent: Head Mounted Display For Virtual Reality (RF 5.2mm f/2.8L)

Rf 5.2mm F/2.8L

Today Canon announced the RF 5.2mm f/2.8L dual fisheye lens for VR. Here is a Canon patent for a head mounted display for VR applications.

Various Canon patent applications that deal with VR applications have been spotted by asobinet.com. Likely they are related to the RF 5.2mm f/2.8L lens.

Canon patent application 2021-89382:

PROBLEM TO BE SOLVED: To provide an electronic device capable of more preferably displaying a VR image captured by using a plurality of optical systems.

[…] to obtain a wide-angle image with parallax using two optical systems, known technique for displaying a VR (Virtual Reality) image having a stereoscopic effect by displaying maps on the virtual sphere. A twin-lens VR camera for capturing an image with parallax has two optical systems oriented in the same direction, and captures two images with parallax by one imaging operation. As a twin-lens VR camera, a camera that captures a wide range of 180 degrees (hemisphere, 90 degrees in all directions from the center of an image) or more in each optical system is known. In addition, as a VR display method, “single-lens VR display” that displays one image by transforming the VR image into a virtual sphere, and VR images for the left eye and the right eye are displayed side by side in the left and right areas. “Binocular VR display” is known.

Canon patent application 2021-118415:

PROBLEM TO BE SOLVED: To appropriately dimm an external light entering between a head-mounted display (HMD) and a face.

In recent years, VR (Virtual Reality) technology that allows users to experience virtual reality and MR (Mixed Reality) technology that allows users to experience mixed reality by seamlessly fusing reality and virtual reality are known. ..
There is a head-mounted display as one of the technologies that allows you to experience the above. If there is a gap between the head-mounted display and the face when the head-mounted display is attached to the head, the displayed image will be difficult to see due to the influence of external light, and the immersive feeling such as virtual reality experience will be reduced.

Canon patent application 2021-118426:

PROBLEM TO BE SOLVED: To improve the compression rate of a moving image composed of a frame image having distortion of a lens and to suppress the processing amount.

Conventionally, a lens for stereoscopic photography has been used as an interchangeable lens system. By using a stereoscopic lens, a pair of left and right parallax images can be captured. When playing back a captured still image or moving image, the image for the right eye is displayed on the user’s right eye, and the image for the left eye is displayed on the left eye. As a result, an image having a parallax is projected on the right eye and the left eye, so that the user can visually recognize the image having a stereoscopic effect. As a related technique, a stereo adapter of Patent Document 1 has been proposed. The stereo adapter of Patent Document 1 has a left opening for capturing a left image and a right opening for capturing a right image, and is left in each region horizontally divided into two in the image pickup unit of the camera. The image and the right image are imaged at the same time.

Interesting times coming for EOS R photographers.

Canon Patent: RF 180mm f/3.5 Macro And RF 200mm f/4 Macro

Canon Patent

And here is a new Canon patent application and as most of them are, this one too is for RF-mount lenses.

asobinet.com spotted Canon patent application 2021-152568 (Japan). The patent application discusses optical formulas for both RF 180mm f/3.5 Macro and RF 200mm f/4 Macro lenses. The former lens might replace the EF 180mm F3.5L Macro USM, a lens that has already been discontinued.

PROBLEM TO BE SOLVED: To provide an optical system which is suitable for a macro lens and can suppress aberration fluctuation.

The optical system of each embodiment has an aperture aperture SP2 as a main focus aperture that determines (limits) the light beam of the open F number (Fno), and a positive refractive power arranged on the object side of the aperture aperture SP2. It has a front focus group LPF, a rear focus group LPR having a positive refractive power arranged on the image side of the aperture aperture SP2, and a negative refractive power arranged on the image side of the rear focus group LPR. It has a posterior group LN. The “group” as used herein means each group of lenses whose spacing changes during focusing.

Embodiment 1:

  • Focal length 171.00
  • F number 3.50
  • Half angle of view (°) 7.21
  • Image height 21.64
  • Overall length of optical system 194.49
  • BF 47.67
  • Magnification ∞ β = -1

Embodiment 2:

  • Focal length 174.43
  • F number 3.50
  • Half angle of view (°) 7.07
  • Image height 21.64
  • Overall length of optical system 189.49
  • BF 13.73
  • Magnification ∞ β = -1

Embodiment 3:

  • Focal length 140.00
  • F number 3.50
  • Half angle of view (°) 8.78
  • Image height 21.64
  • Overall length of optical system 177.49
  • BF 35.17
  • Magnification ∞ β = -1

Embodiment 4:

  • Focal length 194.00
  • F number 4.00
  • Half angle of view (°) 6.36
  • Image height 21.64
  • Overall length of optical system 202.49
  • BF 39.36
  • Magnification ∞ β = -1

More Canon patents are listed here. Some particularly interesting patent applications we think might get into production are these:

Canon Patent: RF 16-30mm f/4-5.6 Lens For The EOR System

Canon Patent

Here is another Canon patent application for an RF-mount lens, as usual spotted by asobinet.com.

Canon patent application 2021-148949 (Japan) discusses optical formulas for what seems to be a RF 16-30mm f/4-5.6 lens for the EOS R full frame mirrorless system. From the patent literature:

PROBLEM TO BE SOLVED: To provide a small and wide angle-of-view zoom lens having high optical performance in the entire zoom range, and an image pickup device and an image pickup system having the same.

[…] In recent years, a zoom lens used in an imaging device is required to have high optical performance in the entire zoom range, to be compact and to have a wide angle of view, as the imaging device becomes more sophisticated. As a zoom lens that is small and relatively easy to widen, a negative lead type zoom lens in which a lens group having a negative refractive power precedes (is located closest to the object side) is known. As a negative lead type zoom lens, Patent Document 1 discloses a zoom lens composed of first to fourth lens groups having negative, positive, negative, and positive refractive powers arranged in order from the object side to the image side. ing. Further, Patent Document 2 discloses a zoom lens composed of first to fifth lens groups having negative, positive, positive, negative, and positive refractive powers arranged in order from the object side to the image side.

If it hits the market, this is going to be an affordable lens for the EOS R system, like the recently released RF 16mm f/2.8 STM pancake lens.

Embodiment 1:

  • Zoom ratio 1.79
  • Wide-angle intermediate telephoto
  • Focal length 16.48 22.05 29.50
  • F number 4.12 4.79 5.61
  • Half angle of view (degrees) 55.80 44.90 35.80
  • Image height 21.64 21.64 21.64
  • Lens total length 100.88 99.27 100.51
  • BF 14.00 16.25 19.80

Embodiment 2:

  • Zoom ratio 1.79
  • Wide-angle intermediate telephoto
  • Focal length 16.48 22.05 29.50
  • F number 4.12 4.12 4.12
  • Half angle of view (degrees) 55.20 45.00 36.20
  • Image height 21.64 21.64 21.64
  • Lens total length 110.07 105.92 108.00
  • BF 12.80 17.50 21.37

More Canon patents are listed here. Some particularly interesting patent applications we think might get into production are these:

Canon Patent: RF 70mm F1.8 STM Lens For EOS R System

Canon Patent

A new Thursday, a new Canon patent. Not surprising yet another one for the RF mount. The whole thing was spotted by asobinet.com.

Canon patent application 2021-131499 (Japan) discusses optical formulas for what appears to be an RF 70mm f/1.8 STM lens for Canon’s full frame mirrorless system EOS R. From the patent literature:

PROBLEM TO BE SOLVED

To provide a compact, lightweight and large-diameter optical system.

Patent Document 1 describes a double-Gauss type optical system capable of correcting various aberrations with a small number of lenses

However, the double-Gauss type optical system as disclosed in Patent Document 1 satisfactorily corrects various aberrations such as spherical aberration and curvature of field when the symmetry is broken due to miniaturization. Becomes difficult. In particular, when the optical system has a large aperture ratio, it becomes difficult to suppress sagittal flare and coma flare at an intermediate angle of view.

Therefore, an object of the present invention is to provide an optical system and an image pickup apparatus having high optical performance while being compact and having a large aperture ratio.

Embodiment 1:

  • Focal length 49.57
  • F number 1.85
  • Half angle of view 23.58
  • Image height 21.64
  • Lens overall length 59.59
  • BF 25.67

Embodiment 2:

  • Focal length 70.00
  • F number 1.85
  • Half angle of view 17.17
  • Image height 21.64
  • Lens overall length 83.52
  • BF 36.62

According to asobinet, the lens discussed in the patent literature has an optical design similar to the RF 50mm F1.8 STM. Maybe it is another excellent performer at an affordable price.

More Canon patents are listed here. Some particularly interesting patent applications we think might get into production are these:

Canon Patent: Automatic Adjustment Of Touchpad AF Sensitivity

Canon Patent Application

Interesting Canon patent application spotted by asobinet.com. The sensitivity of the touchpad used for autofocus tracking is automatically adjusted with regard to shutter speed and the subject.

Canon patent application 2021-128242 discusses technology and methods to automatically set the touchpad sensitivity when tracking a subject with autofocus.

If we got this patent right, the sensitivity of the touchpad is based on subject recognition technology and values computed from the shutter speed and the movement speed of the subject. In other words: if the algorithm detects a fast moving subject and a fast shutter is set, then the sensitivity of the touchpad is increased in the sense that the AF frame will move faster when the touchpad is used to track a subject. Here is the machine translated patent abstract:

Problem: To improve the operability of an AF frame.

Means for solving: A touch detection means capable of detecting touch operation on a touch panel, and a display control means for displaying an item showing an in-focus position on a display part ; A shutter speed acquiring means for acquiring a shutter speed being set and a control means for moving the item on the display part in accordance with the amount of movement of the touch position detected by the touch detecting means, and the control means is used when the touch position detected by the touch detecting means is a 1 movement amount. It has a control means controlled so that a direction when the aforementioned shutter speed is larger than the above-mentioned first value moves the aforementioned item largely rather than the case where the aforementioned shutter speed is smaller than a first value.

And, in particular:

[…] In the method [described in the patent, editor’s note] when the user is chasing a fast-moving subject, if the AF frame is set small, the touch move must be performed many times in order to move the AF frame [and hence the subject tracking might fail, editor’s note] Therefore, the AF frame cannot be moved according to the speed of movement of the user, which may reduce the operability of the user.

Do you think I got the patent right? Feel free to speak out in the comments section.

More Canon patents are listed here. Some particularly interesting patent applications we think might get into production are these: