JP2018081116A - interchangeable lens - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an interchangeable lens capable of preventing unintended functional/operational hindrance to electric and electronic control from outside although it is unnecessary to secure a space for letting a conduction path pass without providing any extra new parts.SOLUTION: The present invention relates to an interchangeable lens comprising: an exterior appearance ring part which is arranged in the exterior appearance of a lens barrel and made of metal; a guide shaft which has electric conductivity and is arranged in parallel with an optical axis to guide and move a lens holding member forward and backward in a direction parallel with the optical axis; a drive part which moves the lens holding member forward and backward in the direction of the optical axis along the guide shaft; a fixed cylinder which has electric conductivity and is fixed to the lens barrel; a mount part which connects the lens barrel to an imaging apparatus; and an electrically conductive plate which has electric conductivity and electrically connects the exterior appearance ring, the guide shaft, and the mount part.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an interchangeable lens that can be attached to and detached from a camera body that is electrically communicated with the camera body for control and the like, and includes an electric circuit and an optical system for communication.

  The interchangeable lens includes various mechanisms such as an optical element, a diaphragm mechanism that controls the amount of light, a focus mechanism that drives an optical element of a focus group, and a camera shake correction mechanism that drives a correction lens for correcting camera shake. These mechanisms provided in recent interchangeable lenses are electronically controlled because they are electronically controlled by communication between the camera body and the interchangeable lens.

  Since the interchangeable lens is electrically equipped, it is necessary to house a main substrate or a flexible substrate on which electronic parts such as a sensor and a microcomputer are mounted in the interchangeable lens. However, the user cannot tolerate an increase in the size of the interchangeable lens. Rather, interchangeable lenses are required to be smaller and lighter.

  Inside the interchangeable lens, which has been electrically reduced and further reduced in size and weight, the mechanical parts and electronic parts are arranged at high density, so if it is electrically affected by internal or external factors of the interchangeable lens, There is a risk of impeding control functions and operations and destroying electronic components. However, it is difficult for a miniaturized interchangeable lens to secure a space for taking measures against these adverse electrical effects.

  In recent interchangeable lenses, synthetic resin materials are used for interchangeable lens parts in order to achieve miniaturization and weight reduction in addition to conventionally used metals.

  Metals are excellent in ensuring accuracy and strength and in conductivity. For this reason, interchangeable lenses often use metal as a fixed cylinder for accurately supporting and moving the optical elements inside the interchangeable lens, and the mount for connecting the interchangeable lens itself to the camera body is made of metal. Mainstream.

  Synthetic resin materials are excellent in weight reduction and processing costs.

  After selecting the optimum material for each part, parts different from metal and synthetic resin material are mixedly arranged inside the interchangeable lens.

There are many opportunities for the user to manually operate the interchangeable lens, such as manual focus operation, zooming operation, and attachment / detachment operation of the interchangeable lens. When the user performs a focus operation, the optical elements in the focus group move along the main axis and the sub axis. Therefore, the main shaft and the sub shaft are made of metal for the guide shaft in order to accurately support and move the optical element. In particular, a guide shaft is generally used for a mirrorless interchangeable lens.

  When the interchangeable lens is operated with the user charged, if high-voltage static electricity is discharged to the interchangeable lens, it passes through the interchangeable lens, adversely affecting control, There is a risk of destroying parts.

  Therefore, there is an EMC test or the like in order to prevent unintentional electricity from adversely affecting the electronic device from inside and outside the electronic device. The EMC test includes an EMI test for measuring the influence of electromagnetic noise generated inside the electronic device on the outside, and an EMS test for measuring resistance against the electromagnetic noise generated outside the electronic device.

  From the results of this EMC test, countermeasures against adverse effects on electromagnetic noise inside and outside the electronic device, such as a design change of the mechanical mechanism of the interchangeable lens and the addition of antistatic components, are taken.

  A common measure against electromagnetic noise in electronic equipment is to design the mechanism so that electricity passing inside the electronic equipment passes through a conductive member, so that unintended electricity can be transferred to the reference potential of the electronic equipment. To the ground and ground.

  In the lens barrel described in Patent Document 1, a high voltage current such as static electricity is applied to the lens barrel and adversely affects an electronic circuit included in the lens barrel, thereby causing the camera to malfunction. As a countermeasure, the lens barrel is made of molded resin mixed with conductive carbon fiber, and the cam follower and gear mechanism are also made of conductive material. A method of connecting to the ground of a circuit is disclosed.

JP 2001-337260 A

  However, since the lens barrel described in Patent Document 1 electrically connects the exterior portion of the conductive lens barrel and the grounding portion of the electronic circuit inside the lens barrel, the lens barrel from the exterior portion of the lens barrel. There is a problem that the number of parts that intervene to electrically connect the grounding portion of the electronic circuit inside the lens barrel increases.

  In addition, since the parts intervening to electrically connect the lens barrel to the grounding portion of the electronic circuit inside the lens barrel are conductive, carbon fiber or metal is used as the material, so the material is expensive. Has the problem of becoming.

  The present invention has been made in view of such a situation, and it is not necessary to secure a space for passing a conduction path without increasing new parts, but functions and operations for electronic control by unintended electricity from the outside. It is an object of the present invention to provide an interchangeable lens that can prevent the occurrence of obstruction and the destruction of electronic components.

  A first invention, which is a means for solving the above-described problems, includes an appearance ring portion made of metal that is disposed on the exterior of a lens barrel, a conductive electrode that is disposed in parallel to the optical axis, and a lens holding member. A guide shaft that guides the lens holding member so as to move forward and backward in a direction parallel to the optical axis; a drive unit that moves the lens holding member forward and backward in the optical axis direction along the guide shaft; A fixed cylinder fixed to the cylinder, a mount portion that connects the lens barrel to the imaging device, and a conductive plate that is electrically conductive and electrically connects the appearance ring, the guide shaft, and the mount portion. And an interchangeable lens.

  A second invention, which is a means for solving the above-mentioned problems, is the interchangeable lens described in the first invention, wherein the appearance ring portion is a decorative ring of the lens barrel or the lens mirror. The ring is located on the side surface of the cylinder.

  According to the present invention, it is not necessary to secure a space for passing a conduction path without increasing new parts, but functions and operations are inhibited against electronic control by unintended electricity from the outside, and electronic components are destroyed. It is possible to provide an interchangeable lens that can prevent this.

Sectional drawing which concerns on the Example of this invention

  The best mode for carrying out the present invention will be described below with reference to the accompanying drawings. In addition, this invention is not limited by this embodiment.

  The interchangeable lens 100 is detachable from a camera body (not shown), and the mount portion 101 of the interchangeable lens 100 and the mount portion of the camera body are connected by a bayonet mechanism or the like. Since an interchangeable lens having a long and long focal length may be connected to the camera body, the mount portion of the camera body is required to ensure strength and accuracy. Therefore, the mount part of the camera body is generally made of metal. The mount portion of the camera body includes various terminals that perform communication between the interchangeable lens 100 and the camera body, supply power from the camera body to the interchangeable lens 100, and align the reference potentials of the camera body and the interchangeable lens 100. It has been.

  The interchangeable lens 100 includes a metal member and a member made of a synthetic resin (plastic).

  Since the interchangeable lens 100 is required to be small and light, it is desirable to use a lot of synthetic resin as a material for a member of the interchangeable lens in order to realize a small and light weight. Actually, it is easy to become a member made of synthetic resin except for a portion where strength and accuracy are desired, such as a mount portion for mounting an interchangeable lens and a fixed tube for supporting a cam tube. However, if synthetic resin is frequently used as a material of the member of the interchangeable lens 100, there is a possibility that an unintended electricity generated inside the interchangeable lens 100 or given from outside may have an adverse effect. Since the interchangeable lens 100 uses synthetic resin for the fixed cylinder 103 and the fixed cylinder b110, since the metal part 105 and the mount 101 are not electrically connected, there is a possibility that unintended electricity may adversely affect the interchangeable lens 100. . Therefore, it is necessary to consider design in order to induce unintended electricity by using a metal member having high conductivity, and to prevent an adverse electrical effect on the electronic component and the mounting board.

  FIG. 1 is a cross-sectional view of the interchangeable lens 100 of the present embodiment cut along a plane parallel to the optical axis. FIG. 1 is simplified to simplify the description of the present invention. The left side of the figure is the object side, and the right side is the image side.

  In the interchangeable lens 100 of this example, 101 is a mount, 102 is a rear cylinder, 103 is a fixed cylinder, 104 is a focus ring, 105 is a metal part, 106 is a conduction plate, 107 is a main shaft, 108 is a mounting board, 109 is a sub-board. A shaft 110 is a fixed cylinder b, and L1 to L3 are lens groups.

  In the present embodiment, the mount 101, the rear cylinder 102, the metal part 105, the conductive plate 106, the main shaft 107, and the auxiliary shaft 109 are all made of metal.

  The mount 101 and the rear cylinder 102 are connected and fixed to each other with screws, and since both members are made of metal, they have conductivity. Therefore, even when unintended electricity is given from the outside, there is a property of preferentially inducing electricity.

  The fixed cylinder 103 and the fixed cylinder b110 are the basis of the interchangeable lens 100, and the fixed cylinder 103 and the fixed cylinder b110 themselves are not rotated by the operation of the interchangeable lens 100. Moreover, since the fixed cylinder 103 and the fixed cylinder b110 are made of synthetic resin, even when unintended electricity is given from the outside, it is difficult for the fixed cylinder 103 and the fixed cylinder b110 to pass through.

  The focus ring 104 is an appearance member, and the focus position can be adjusted by a user's manual operation.

  The metal part 105 is an appearance member. In this embodiment, the ring is arranged at the name ring position, but it may be a ring on the side surface of the interchangeable lens 100.

  The main shaft 106 is made of metal and is connected to a motor (not shown). The lens group L2 moves while sliding in the optical axis direction along the main shaft 106 and the sub shaft 109 by the rotation of the motor as the driving unit.

  The conductive plate 107 is made of metal and electrically connects the metal part 105 and the main shaft 106, and the main shaft 106 and the mount 101. When the substrate 108 is electrically connected to the mount 101, the main shaft 106 may be electrically connected to the mount 101 through the substrate 108.

  The substrate 108 performs control of the interchangeable lens 100, communication processing with the camera body, and the like. The substrate 108 is surrounded by the mount 101 and the rear cylinder 102. The substrate 108 has a substantially ring shape or a C shape with a part of the circumference cut out.

  From the above, in the interchangeable lens 100 according to the present invention, the main shaft 106 and the image-side conductive plate 107 are again connected from the external metal part 105 positioned on the object side of the interchangeable lens 100 via the object-side conductive plate 107. To the mount 101 are electrically connected. That is, the external metal part 105 of the interchangeable lens 100 is electrically connected to the mount 101 serving as a ground. As a result, by attaching the metal part 105 to the external appearance of the interchangeable lens 100, charges are not accumulated in the metal part 105 during the EMC test, and static electricity does not fly to the internal parts.

  If it does so, this invention does not need to add the flexible, copper foil tape, press part, etc. which were conventionally used for the countermeasure against static electricity inside the interchangeable lens 100. FIG.

  Therefore, the present invention uses a metal-made conductive main shaft 106 as a part of the conduction path from the metal part 105 to the mount 101, so that a flexible or copper foil tape for newly passing the conduction path, There is no need to secure space for press parts.

  In the embodiment of the present invention, the metal part 105 that is the appearance member is arranged at the name ring position, but the ring may be located on the side surface of the interchangeable lens 100. In that case, needless to say, the object-side conductive plate 107 is arranged to electrically connect the metal part 105, which is a ring located on the side surface of the interchangeable lens 100, and the main shaft 106.

  In this embodiment, the main shaft 106 is used as a part of the conduction path from the metal part 105 to the mount 101. However, if the metal part 105 is electrically connected to the mount 101, the sub shaft 109 is used instead of the main shaft 106. It goes without saying that there is no problem even if it is used for the conduction path.

100 Interchangeable lens 101 Mount 102 Rear cylinder 103 Fixed cylinder 104 Focus ring 105 Metal part 106 Main shaft 107 Conducting shaft 108 Substrate 109 Sub axis 110 Fixed cylinder

Claims (2)

An appearance ring portion made of metal disposed on the exterior of the lens barrel;
A guide shaft that has conductivity and is arranged in parallel with the optical axis and guides the lens holding member so as to move forward and backward in a direction parallel to the optical axis;
A drive unit that moves the lens holding member forward and backward in the optical axis direction along the guide shaft;
A non-conductive, fixed cylinder fixed to the lens barrel;
A mount for connecting the lens barrel to the imaging device;
A conductive plate having conductivity and electrically connecting the appearance ring, the guide shaft, and the mount;
An interchangeable lens comprising:   2. The interchangeable lens according to claim 1, wherein the appearance ring portion is a decoration ring of the lens barrel or a ring positioned on a side surface of the lens barrel.

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