Canon Patent: Underwater Attachment Optic For Better Performance

Canon Patent

Very interesting Canon patent application. If I got it right, it is for a sort of underwater attachment optic you can mount on a telephoto lens. The optical system should deliver an optical underwater performance that’s close to what you get when using the lens on the surface (i.e. in “air”).

Canon patent application 2022-24363 (Japan) discusses technology and optical formulas for an optical filter system that gets mounted on a lens and should deliver much better optical performance under water.

PROBLEM TO BE SOLVED: To provide an attachment optical system capable of obtaining optical performance close to that in the case of use in air when used in water with a simple configuration.

Conventionally, an attachment optical system for mounting on an image pickup lens is known. In recent years, the number of users who enjoy shooting underwater is increasing, and the demand for an image pickup lens optimally designed for underwater use is increasing. Generally, as an underwater camera or an amphibious camera, a camera in which the camera is housed in an underwater housing or a camera in which the camera itself is provided with a waterproof mechanism is used. However, the refractive index and dispersion of water and salt water are different from those in air. For example, the refractive index for the d-line is about 4/3 with respect to air, and the dispersion is about 62 in Abbe number. Therefore, when an image pickup optical system whose aberration is sufficiently corrected in air is used in water, the refraction action at the interface between water and the image pickup optical system changes, and the optical performance deteriorates due to the change in aberration.

When an optical system that has been subjected to aberration correction on the assumption that it is used in air is used in water, the aberration changes as described above. Specifically, it is necessary to extend the focus lens group in order to generate curvature of field on the over side, distortion, and to shift the focus position to the rear of the image plane and return the focus to the image plane position. There is the occurrence of aberration fluctuation due to. Further, the change in aberration becomes more remarkable as the thickness of the housing mounted in front of the optical system becomes thicker when used underwater. With the attachment optical system disclosed in Patent Document 1 and Patent Document 2, it is difficult to cope with all of the above-mentioned changes in aberration, and the optical performance when used in water is close to that when used in air. Cannot be obtained.

Therefore, the present invention presents an attachment optical system, an optical system, and a method for manufacturing an optical system, which can obtain optical performance close to that of use in air when used in water with a simple configuration. The purpose is to provide.

The attachment optical system as one aspect of the present invention has a first converter optical system that can be attached to the object side of the image pickup optical system, and the first converter optical system has a dome-shaped cover. It has one unit and a second unit composed of a plurality of lenses, and the second unit has a negative refractive power arranged at a position closest to the first unit in the second unit. The focal length fd of the first unit, the focal length ffc of the second unit, and the focal length fn of the lens having a negative refractive power in the second unit in water having a lens are predetermined conditional expressions. To be satisfied.

asobinet.com suggests this is for movie application and less for stills photography. They also suggest it is for a zoom lens for the Canon EOS Cinema system.

Canon Patent: 135mm f/2 1:2 Macro And 200mm f/2.4 1:2 Macro Lenses

Canon Patent

And yet another Canon patent application: 135mm f/2 1:2 Macro And 200mm f/2.4 1:2 Macro Lenses.

Canon patent application 2022-22595 (Japan) discusses optical formulas for two macro lenses: 135mm f/2 1:2 M.

PROBLEM TO BE SOLVED: To provide an optical system capable of expanding a close range in a small size while suppressing the number of focus groups, and an image pickup apparatus having the same.

If the floating focusing method is used to increase the close-up magnification, the number of lenses in each group increases, and it is difficult to drive the focus group at high speed. In the lenses of Patent Document 1 and Patent Document 2, when the number of lenses in the focus group is reduced in order to realize high-speed drive, sufficient aberration performance cannot be obtained because the configuration of each group is not appropriate.

An object of the present invention is to provide an optical system capable of expanding a close range in a small size while suppressing the number of focus groups, and an image pickup apparatus having the same.

Example 1

  • Focal length: 133.0
  • F value: 2.05
  • Half angle of view: 9.24
  • Image height: 21.64
  • Shooting magnification: -0.5

Example 3

  • Focal length: 200.0
  • F value: 2.40
  • Half angle of view: 6.18
  • Image height: 21.64
  • Shooting magnification: -0.5

Example 4

  • Focal length: 199.9
  • F value: 2.80
  • Half angle of view: 6.18
  • Image height: 21.64
  • Shooting magnification: -1.00

The Canon patent application was spotted by asobinet.com. More Canon patent applications are listed here. Some particularly interesting patent applications we think might get into production are these:

Canon Patent: Rotating Built-in Extender (so you may operate it with just your right hand)

Canon Patent

A new Canon patent. What about a rotating built-in extender you can operate with just one hand?

Canon patent application 2022-23481 (Japan) discusses methods and technology for a built-in rotating extender.

PROBLEM TO BE SOLVED: To provide an optical device advantageous in terms of operability.

Patent Document 1 discloses a lens device including a lens group that can be inserted and removed with respect to an optical axis by an operating member (lever). Further, Patent Document 2 discloses a lens device having a support structure that supports a filter that can be inserted and removed from the optical axis by an operating member.

If the position and operation direction of the operation member are uniquely determined in Patent Document 1 and Patent Document 2, for example, depending on the operator and the operation situation, it may be disadvantageous in terms of operability. An object of the present invention is, for example, to provide an optical device which is advantageous in terms of operability. An optical device 100 is rotatably fixed to a lens barrel portion 11 around a lens 11L, a lens barrel portion 11 holding at least a part of the lens 11L, and an optical axis O of the lens 11L. It has a rotating housing 12, and the rotating housing 12 includes an extender lens barrel 17 that supports a converter 17L that is inserted and removed with respect to the optical axis O.

The Canon patent application was spotted by asobinet.com. They say:

Yesterday [we found a] a patent application that seemed to envision the 400mm F4 DO IS Extender 1.4 × and 600mm F4 IS Extender 1.4 ×, and now a patent application for the structure of the built-in extender has been published. This time, The fact that the structure of the optical system and the moving parts have appeared in a series of patents suggests that they are seriously considering a telephoto single focal length lens with a patent application for the structure of the built-in extender has been published. built-in extender.
This patent application is not just about the movable parts of the built-in extender, but it also aims to make the movable parts rotating to provide operability suitable for various shooting styles.

For example, the current lens with built-in extender, the EF200-400mm F4L IS USM Extender 1.4 ×, has the extender switching lever positioned for left hand operation, so it is not compatible with right hand operation. In fact, some people have commented that they wished it was placed in a position where it could be used for right-handed operation like Nikon’s, so there may be demand for improved operability.
I am wondering if this structure can be implemented in the telephoto L-series, which requires Robustness, but it seems highly likely that research and development is underway for lenses with built-in extenders. We may see more patent applications like this in the future.

Canon Patent: Switch Between Electronic And Dot-sight Viewfinder

Canon Patent

This seems a rather interesting and innovative Canon patent application. How about switching between dot-sight and electronic viewfinder?

Canon patent application 2022-23783 (Japan) discusses methods and technology for a device that allows to switch between dot-sight and electronic viewfinder. If you want to learn more about dot-sight, have a look here.

PROBLEM TO BE SOLVED: To provide a small display device capable of switching between a sight and an electronic viewfinder.

Conventionally, when a distant moving subject such as a bird or an airplane is photographed by using an image pickup device, a sighting device called a dot sight is widely used. Further, in an image pickup device equipped with a high-magnification lens, a display device such as an electronic viewfinder is widely used in order to enable stable shooting. Patent Document 1 discloses an image pickup apparatus including both an electronic viewfinder and a sighting device.

However, in the image pickup device disclosed in Patent Document 1, since the function of the sighting device and the function of the electronic viewfinder are realized by using different display devices, the size of the image pickup device becomes large.

The display device as one aspect of the present invention is arranged between the image display element, the eyepiece, the objective window, and the eyepiece and the objective window, and is displayed on the image display element. It has a reflective optical element that guides the image to the eyepiece, and the reflective optical element can switch between the first state and the second state by changing the transmission rate, and the first state. In, the image displayed on the image display element can be visually recognized through the eyepiece, and in the second state, the image from the objective window and the image through the eyepiece. It is possible to visually recognize an image in which an image displayed on the display element is superimposed.

According to the present invention, it is possible to provide a small display device and an image pickup device capable of switching between a sighting device and an electronic viewfinder.

Is this cool? Me thinks it is.

The Canon patent application was spotted by asobinet.com. More Canon patent applications are listed here. Some particularly interesting patent applications we think might get into production are these:

Canon Patent: 400mm f/4 DO IS Extender 1.4x and 600mm f/4 IS Extender 1.4x

Canon Patent

A new Canon patent application was spotted. 400mm f/4 DO IS Extender 1.4x and 600mm f/4 IS Extender 1.4x are discussed.

Canon patent application 2022-22771 discusses optical formulas for two rather interesting lenses:

  • 400mm f/4 DO IS Extender 1.4x
  • 600mm f/4 IS Extender 1.4x

PROBLEM TO BE SOLVED: To provide an optical system in which a magnification conversion optical group can be inserted and removed and the total length is short.

As a method of changing the focal length of the optical system used for imaging, there is a method of inserting a magnification conversion optical group such as an extender into the optical path . Further, as an optical system in which the total length (distance from the optical surface on the object side to the image surface) does not change due to the insertion / removal of the magnification conversion optical group, Patent Document 1 describes the axial light beam between the aperture stop and the image surface. An optical system capable of inserting and removing a magnification conversion group at a converging position is disclosed.

However, if a space for inserting the magnification conversion optical group is provided between the aperture diaphragm and the image plane as in Patent Document 1, the total length of the original optical system becomes long . Further, if the magnification conversion optical group is inserted in a narrow space, various aberrations of the optical system may increase. The
present invention provides an optical system in which a magnification conversion optical group can be inserted and removed, but the total length is short and good optical performance can be obtained.

Example 1

  • Focal length: 392.58
  • F value: 4.12
  • Half angle of view: 3.15
  • Image height: 21.64
  • Overall length: 280.33
  • Back focus: 36.01

Example 1 (with inserted teleconverter)

  • Focal length: 549.72
  • F value: 5.77
  • Half angle of view: 2.25
  • Image height: 21.64
  • Overall length: 280.33
  • Back focus: 36.00

Example 5

  • Focal length: 585.00
  • F value: 4.12
  • Half angle of view: 2.12
  • Image height: 21.64
  • Overall length: 467.45
  • Back focus: 55.50

Example 5 (with inserted teleconverter)

  • Focal length: 819.18
  • F value: 5.77
  • Half angle of view: 1.51
  • Image height: 21.64
  • Overall length: 467.45
  • Back focus: 55.50

The Canon patent application was spotted by asobinet.com. More Canon patent applications are listed here. Some particularly interesting patent applications we think might get into production are these:

Canon Patent: Externally Connected Camera Cooling Device

Canon Patent

Well, that’s a somewhat different Canon patent application for once.

Canon patent application 2022-21539 (Japan) discusses methods and technology to connect an external camera cooling device.

PROBLEM TO BE SOLVED: To provide an externally connected electronic device for cooling that can be connected to an image pickup device.

The present invention relates to an electronic device, and more particularly to an electronic device that can be externally connected to an image pickup device and dissipate heat to the image pickup device. However, in the technique described in Patent Document 1, by arranging the ventilation duct inside the image pickup device, a large space for installing the blower duct is required, which may hinder the miniaturization of the image pickup device. The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide an externally connected electronic device that can be connected to an image pickup apparatus.
In order to solve the above problems, the present invention comprises an interface unit including a connection unit that can be attached to the external device by connecting to an interface terminal provided in the external device, a heat transfer unit, a heat dissipation unit, and the like . The electronic device is characterized in that the heat transfer section and the heat dissipation section are connected to the interface section, and the interface section is in the opposite direction to the external device when the interface section is connected to the external device. offer.

If we got it right, it is an external cooling device that can be attached to the camera and connected to an USB port. We think the device has a Peltier element and a fan. It can be attached when needed, so it can be seen as a portable camera cooling device.

The camera depicted in the drawings appears to be a mirrorless camera, and pretty much looks like an EOS M camera. Canon planing to release an overheating EOS M model? :-)

The Canon patent application was spotted by asobinet.com. More Canon patent applications are listed here. Some particularly interesting patent applications we think might get into production are these: