Canon Patent: AF-Motor With Reduced Size And Lower Power Consumption

Canon Patent

A new Canon Patent application.

Canon patent application 2023096628 (Japan, published 7/7/2023) discusses technology and methods for a autofocus-driving motor with reduced size and lower power consumption.

The motor described in the the patent literature is a “linear motor”. Canon interchangeable lenses have a “ring-type USM”-motor for single-lens reflex cameras and a “NanoUSM”-motor for mirrorless cameras. Both are driven by ultrasonic waves, so this would be a new kind of motor driving Canon lenses.

From the patent literature:

A linear motor, a lens barrel, and a driving device that can improve power efficiency while suppressing an increase in external size are provided. BACKGROUND ART A linear motor is a motor that mainly generates force in one direction

It is used in a wide range of industrial fields. Linear motors are often used exclusively in linear drive applications and are often used in combination with linear guide mechanisms. Linear motors are classified into electromagnetic, pressure, friction, and tension/extrusion types according to the principle of thrust generation, and into finite tracks, endless tracks, etc. according to the drive range. be. In addition, devices that use mechanisms such as so-called rack and pinions and tires to convert the thrust of a normal rotary motor into linear thrust are also broadly classified as linear motors (linear actuators).

An example of the use of a linear motor is a focusing mechanism in a lens barrel. In the lens barrel, the focus operation is performed by moving the focus lens group inside the lens barrel back and forth on the optical axis perpendicular to the camera’s image sensor in order to focus on the subject at the desired position when shooting. is done. A linear motor is used to adjust the movement of the focus lens group.

Necessary conditions for the linear motor used in the focus mechanism in the lens barrel are that it has a size that fits inside the lens barrel, and that the maximum output and resolution of the thrust force sufficient to move and adjust the focus lens group are required. Being prepared, being quiet, etc. To meet these conditions, among the above categories, electromagnetic linear motors with finite trajectories are used, especially voice coil motors (VCMs), which generate the Lorentz force through a combination of permanent magnets and coils. may occur.

Since the VCM does not generate thrust when it is not energized, when using the VCM as a focus mechanism in the lens barrel, it is necessary to always energize the VCM to hold the focus lens group during use. For this reason, depending on the shooting scene, it may consume a large amount of power and the battery of the camera will be consumed faster than when using other friction type ultrasonic motors for the focusing mechanism in the lens barrel. be. Therefore, when a VCM is used as a focusing mechanism in the lens barrel, it is required to improve the power efficiency of the VCM.

In order to improve the power efficiency of a VCM with a finite orbit without increasing the external size, the efficiency of a magnetic circuit composed of a permanent magnet and a yoke (hereinafter simply referred to as magnetic efficiency), that is, the coil area of ​​the VCM The key is how to increase the density of the magnetic flux that contributes to the generation of thrust. The magnetic circuit here is an expression that compares the flow of magnetic flux in space to the flow of current in a circuit, and indicates the direction and magnitude of the magnetic flux density at each point. itself is also shown. In addition, in general finite orbit VCM, it is known that the magnetic efficiency is relatively lower at both ends of the drive stroke than at the center, and it is important in practice to suppress this. (See, for example, Patent Document 1).

However, in the VCM of Patent Document 1, since the magnetic efficiency in the central portion of the driving stroke is reduced in order to equalize the magnetic efficiency in the driving stroke, there is a problem that the power efficiency as a whole deteriorates. In addition, since the configuration of Patent Document 2 requires a separate fixing means for fixing the magnet, there is a problem that the external size of the linear motor tends to increase.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide a linear motor, a lens barrel, and a driving device that can improve power efficiency while suppressing an increase in external size.

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

[via asobinet]

Canon Patent: Medical Devices To Use EOS R Technology

Canon Patent

Canon wants their EOS R system (and technology) to be everywhere. Medical devices included.

A newly spotted Canon patent (published 6/6/23) discusses methods and technology to implement EOS R camera technology on medical devices.

From the patent literature:

An object of the present invention is to provide an imaging apparatus that enables confirmation of medical information and imaging parameters, and also allows confirmation of medical information before imaging of image data.

Description of the Related Art Techniques

For associating an image with information about the subject of the image have been proposed. In Patent Document 1, in an imaging device, an image of a code is captured, the code is analyzed, patient information corresponding to the code is acquired from a database, the patient information is superimposed on a live view image, and captured image data is obtained. It is described that patient information is recorded in association with.

In a camera that stores medical information such as patient information in association with image data, it is important for the user to confirm that the medical information is correct. there is Furthermore, at the time of shooting, it is also important to check shooting parameters (Av/Tv/exposure compensation/Iso, etc.) for shooting high-quality image data.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide an imaging apparatus that
enables confirmation of medical information and imaging parameters, and also allows confirmation of medical information prior to imaging of image data.

This going to be part of Canon’s Medical Photo Solutions. The example shows a camera with an EOS R-like design and the ability to display medical parameters. Using the network system, it will be possible to display information on the camera by linking it with the hospital system.

[via asobinet]

Canon Patent: 35mm f/1.3 Lens With Very Short Back Focus

Canon Patent

A new Canon patent was spotted. Will this lens ever hit the shelves? Unlikely in our opinion.

Canon patent application 2023077336 (Japan, published 6/5/23) discusses optical formulas for a 35mm f/1.3 lens.

An object of the present invention is to realize an optical system capable of reducing ghosts in a desired wavelength region in spite of having a large aperture and a small lens.

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention relates to an optical system and the like, and is suitable for imaging apparatuses such as digital video cameras, digital still cameras, broadcast cameras, surveillance cameras, cameras for wearable devices, and cameras for mobile devices.

2. Description of the Related Art
There is a demand for a high-performance optical system that reduces the occurrence of ghosts and flares. In order to reduce the occurrence of ghosts and flares, a method of providing an antireflection film on the lens surface is known.
In recent years, optical systems have become larger in diameter and smaller in size, and the opening angle of lenses tends to increase. However, due to problems in manufacturing the antireflection film, the antireflection effect in the periphery of the lens with a large opening angle may be inferior to the antireflection effect in the position on the optical axis.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide an optical system capable of reducing ghosts, particularly in a desired wavelength region, while having a large aperture and a small lens.

Example 1

  • Focal length: 12.40
  • F-value: 1.30
  • Half angle of view: 32.82
  • Image height: 8.00
  • Overall length: 21.76
  • Back focus: 0.44

Example 2

  • Focal Length: 33.53
  • F-value: 1.30
  • Half angle of view: 32.83
  • Image height: 21.64
  • Overall length: 61.97
  • Back focus: 0.29

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

Canon Patent For Box-shaped Camera Body (Cinema EOS?)

Canon Patent

Rather interesting Canon patent application. A box-shaped interchangeable lens camera.

Canon patent application 2023024538 (Japan, published 2/16/2023) discusses methods and technology for a box-shaped camera (or a protection for a box-shaped camera?).

From the patent literature:

A camera mount protection when a lens is removed from an imaging device with a detachable lens.

Description of the Related Art

A lens-exchangeable imaging apparatus is known in which a lens device can be attached to and detached from a mount formed on the front surface of a camera body. Also, interchangeable-lens imaging devices with a very short distance from the lens mount to the image sensor have appeared, such as so-called mirrorless cameras that do not have a reflecting mirror to guide the incident light of the lens device to the optical viewfinder.

Further, some interchangeable-lens imaging apparatuses have a tripod or a seat on a plurality of side surfaces of the camera body, and are capable of vertical shooting or upside-down shooting. Patent Literature 1 discloses a camera having a mounting surface and a tripod mount on the top surface. Or you can shoot with the camera fixed upside down on the gimbal.

In Patent Document 1, the lens mount protrudes from the camera body when the camera is viewed from the front side. Therefore, if the camera is placed with the mount surface facing downward while the lens device is removed from the camera body, the mount surface may be damaged.

In addition, when a large lens device is attached to the camera body, the center of gravity of the camera as a whole is shifted forward from the tipping limit, and there is a concern that the camera may topple forward. This is especially noticeable when the camera body is made smaller and lighter, such as with a mirrorless mount.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an image pickup device capable of protecting the mount of the image pickup device when the lens is removed.

More Canon patent applications are listed here

[via asobinet]

Canon Patent: 18-100mm F4 And 14-60mm F4 Lenses

Canon Patent

Another Canon patent application today, for a 18-100mm f/4 lens and a 14-60mm f/4 lens.

Canon patent application 2023018409 (Japan, published 2/8/2023) discusses optical formulas for two lenses we think are for the RF mount, 18-100mm f/4 and a 14-60mm f/4.

From the patent literature:

To provide a zoom lens that is compatible with a short back and suppresses variations in optical performance due to focusing in a wide-angle range with a wide angle of view.

Description of the Related Art

There is a demand for a compact and lightweight zoom lens compatible with a so-called mirrorless camera without a quick return mirror. For example, it consists of a first lens group with positive refractive power, a second lens group with negative refractive power, and a subsequent group including a plurality of lens groups, arranged in order from the object side to the image side, and the second lens group is the main lens group. A zoom lens with a variable power group is known (.

Further, in recent years, in order to reduce the size of the zoom lens, an imaging apparatus has been proposed that electrically corrects distortion mainly in a wide-angle range among various aberrations of a zoom lens. However, in such an image pickup apparatus, field curvature fluctuations, in particular, become large as aberration fluctuations during focusing.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a zoom lens that is compatible with shortback and suppresses fluctuations in optical performance due to focusing in a wide-angle range with a wide angle of view, and an imaging apparatus and an imaging system having the zoom lens.

Example 1

  • Focal length: 15.45-68.00
  • F-value: 4.12
  • Half angle of view: 36.92-11.36
  • Total length: 106.58-125.20
  • Back focus: 10.68-12.16

Example 2

  • Focal length: 13.40-63.10
  • F-value: 4.12
  • Half angle of view: 40.91-12.22
  • Overall length: 105.91-129.46
  • Back focus: 11.16

Example 3

  • Focal length: 18.00-88.20
  • F-value: 4.12
  • Half angle of view: 32.82-8.80
  • Total length: 108.02-127.32
  • Back focus: 11.42

More Canon patent applications are listed here.

[via asobinet]

Canon Patent: RF 100-300mm F2.8 x 1.4 Extender Lens

Canon Patent

A new Canon patent application for another RF mount lens. Canon patent application 2023018429 (Japan, published 2/8/2023) discusses optical formulas for an RF 100-300mm F2.8 x 1.4 extender lens.

From the patent literature:

A zoom lens having a large aperture and a long focal length is provided, in which the focal length range can be easily changed to the long focal length side by an extender, and good optical performance can be maintained even before and after the extender is inserted.

A known method is to change the focal length of the optical system by inserting an extender (magnification conversion group) separate from the main optical system.

However, since a large air gap is required to insert the extender into the optical path, if the position for inserting the extender is inappropriate, the size of the main optical system and the extender will increase. Also, in order to maintain good optical performance before and after inserting the extender, it is necessary to appropriately set the refractive powers of the lens groups before and after the extender.

In the present invention, by inserting an extender into the main optical system, the focal length range can be easily changed to the long focal length side. The purpose is to provide a long zoom lens.

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

[via Digicame-Info]