JP2009210991A - Accessory lens unit and imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a structure facilitating attachment and detachment of a lens adaptor installed with an accessory lens to and from an imaging apparatus body, matching the optical axis of the accessory lens installed to the lens adaptor to that of a lens group of an imaging optical system as much as possible, and preventing breakage of the imaging apparatus even if external force is applied to the lens adaptor by preventing the force from being transmitted to a lens barrel unit having a photographic optical system. <P>SOLUTION: The accessory lens unit to be detachably attached to an imaging apparatus including a lens barrel unit including an imaging optical system and an imaging device, and a facing member formed to expose the lens barrel unit, includes: an engagement part for determining positions in an optical axial direction and in a direction orthogonal to the optical axis by being directly engaged with the lens barrel unit; and a contact part which does not contact with the facing member when no external force is applied to the accessory lens unit, and contacts with the facing member when external force is applied to the accessory lens unit. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an accessory lens unit mounting structure to an imaging device.

  2. Description of the Related Art Conventionally, it has been known that an imaging apparatus can further improve the imaging effect by using accessory lenses such as a teleconverter lens, a wide converter lens, and a close-up lens that are detachably attached to the imaging apparatus body. Note that the teleconverter lens and the wide converter lens may be simply referred to as a conversion lens.

  When attaching such an accessory lens to the imaging apparatus main body, it is important that the optical axes of the imaging optical system arranged in the imaging apparatus main body and the optical system of the accessory lens are matched and matched with high accuracy. This is because if the optical axis is displaced, the captured image has a problem such as one-sided blur.

  Various methods have been proposed for attaching the lens adapter to the imaging apparatus main body as described below.

  For example, Patent Document 1 (Japanese Patent Laid-Open No. 2005-156765) discloses that a lens adapter body is bonded and fixed to the tip of a lens barrel (page 7, FIG. 1). Patent Document 2 (Japanese Patent Application Laid-Open No. 2006-2032121) discloses that a lens adapter is mounted by a bayonet method on a front cover where a lens barrel is positioned.

There exists patent document 3 as another prior art.
Japanese Patent Laying-Open No. 2005-156765 (page 7, FIG. 1) Japanese Patent Laying-Open No. 2006-201321 (page 15, FIG. 10, FIG. 17) JP 2004-264367 A (page 13, FIG. 1, FIG. 2, FIG. 3)

  However, in Patent Document 1, since the lens adapter is fixed to the tip of the collapsible lens barrel, it is difficult to remove the lens adapter, which is not convenient. If the adhesive part is forcibly removed, the lens barrel itself may be damaged. Further, when an external force is applied to the lens adapter when the lens adapter is mounted, the force may be applied to the lens barrel and the operation of the lens barrel unit may become unstable, or in the worst case, the lens barrel unit may be damaged.

  In Patent Document 2, regarding positioning in a direction perpendicular to the optical axis, one component called a front cover is interposed for positioning the lens barrel unit and the lens adapter. Therefore, if the dimensions of the positioning accuracy portions of the front cover vary, the optical axes of the lens in the lens barrel unit and the lens in the lens adapter will shift.

  In consideration of the above-described facts, the present invention makes it easy to attach and detach the lens adapter equipped with the imaging device main body and the accessory lens, and both optical axes between the lens group of the imaging optical system and the accessory lens attached to the lens adapter. An accessory lens unit and an image pickup device having a structure that prevents damage to the device by preventing the device from being transmitted to the lens barrel unit having the photographing optical system even when an external force is applied to the lens adapter. It relates to providing an apparatus.

  An accessory lens unit according to one aspect of the present invention is an accessory that is detachably attached to an imaging apparatus having a barrel unit including an imaging optical system and an imaging element, and an exterior member formed to expose the barrel unit. A lens unit that directly engages the lens barrel unit to determine the position in the optical axis direction and the direction orthogonal to the optical axis, and abuts on the exterior member when no external force is applied to the accessory lens unit And an abutting portion that abuts against the exterior member when an external force is applied to the accessory lens unit.

  An imaging device according to another aspect of the present invention is an imaging device to which the accessory lens unit described above is detachably attached, and a barrel unit including an imaging optical system and an imaging element, and a barrel unit are exposed. The lens barrel unit engages with the engaging portion to determine the position of the accessory lens unit in the optical axis direction and the optical axis orthogonal direction, and has a holding portion for holding the accessory lens unit. The exterior member has a receiving portion that receives contact of the contact portion when external force is applied to the accessory lens unit without receiving contact of the contact portion when external force is not applied to the accessory lens unit. It is characterized by having.

  It is easy to attach and detach the lens adapter equipped with the imaging device body and the accessory lens. Both the optical axes of the lens group of the imaging optical system and the accessory lens attached to the lens adapter are matched as much as possible. Provided are an accessory lens unit and an imaging device having a structure that prevents destruction of the device by preventing the force from being transmitted to a lens barrel unit having a photographing optical system even when external force is applied to the lens.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, taking an imaging apparatus as an example. In addition, in each figure, the same reference number is attached | subjected about the same member and the overlapping description is abbreviate | omitted.

  3 and 4 show an outline of the electronic imaging apparatus given as an example, and an outline of the apparatus will be described below. Here, FIG. 3 is a schematic front perspective view of the apparatus of the present invention. FIG. 4 is a schematic front perspective view of the apparatus of the present invention, showing a state where the apparatus is turned on and the lens barrel unit is extended.

  In FIG. 3, reference numeral 101 denotes an imaging apparatus main body. As shown in the figure, the imaging apparatus main body 101 is covered with an exterior member. A lens barrel unit provided with a photographing optical system lens, a lens barrier, a photoelectric conversion element such as a CCD (or other photoelectric conversion elements such as CMOS), a feeding mechanism, a zoom mechanism, a shutter, etc. on the front surface of the image pickup apparatus main body 101 102 is partially exposed. A subject image is formed on the image sensor by an optical system disposed inside the barrel unit 102. Reference numeral 110 denotes a grip portion for the operator to hold the exterior member of the imaging apparatus main body 101 with the right hand.

  A strobe light emission window 111 is provided at the upper right of the lens barrel unit 102 to emit light as necessary when the amount of light is insufficient during photographing. A voice input microphone (not shown) is provided in the upper left part of the barrel unit.

  Reference numeral 103 denotes a front cover made of a resin member that covers the front portion of the imaging apparatus main body. The front cover 103 is integrally formed with an opening for exposing the strobe light emission window 111 and a bayonet coupling portion described later, and further, a bayonet lock mechanism component and a bayonet lock release button 112 are incorporated.

  In FIG. 4, reference numeral 113 denotes a power button. When the button is pressed and the power is turned on, the lens barrel unit 102 is extended from the state of FIG. 3 to the state of FIG. A zoom lever 114 has a structure that can be rotated clockwise to a predetermined position (Q) and counterclockwise (P). The zoom lever 114 is an input interface to the imaging apparatus main body 101 that changes the positional relationship of the photographing optical system lens group provided in the lens barrel unit 102 and zooms from wide angle to telephoto. The zoom lever 114 is configured to return to its initial position by the biasing force of a spring (not shown) when the operator releases the hand after operating in the P and Q directions.

  A rear cover covers the apparatus main body 101 on the rear side of the apparatus, and display means for displaying characters, images, and the like, for example, a liquid crystal display apparatus is provided at the left of the center of the rear cover. This liquid crystal display device is used for displaying a selection menu and icons for confirming a subject image to be captured, reproducing and displaying the captured image, and changing device settings. The rear cover is provided with an opening or a transparent window (LCD window) so that the liquid crystal display device can be seen.

  Reference numeral 115 denotes a shutter button. By operating the shutter button 115, the subject is imaged and the image data of the subject image is recorded on a recording medium incorporated in the apparatus main body. At this time, audio data from the microphone can be recorded together with the image data. An audio playback speaker (not shown) is provided inside the apparatus, so that audio stored in a recording medium can be played, and operation sounds recorded in the recording unit in advance can be played back. .

  In addition, a battery lid (not shown) that can be opened and closed with respect to the apparatus main body 101 is provided on the bottom surface of the exterior member of the apparatus main body 101, and a main battery (not shown) serving as a power source is inserted into the apparatus main body 101 in a detachable manner. . The recording medium (card type memory) can be inserted and removed when the battery cover is open. In addition, a mode switching lever is provided on the back of the apparatus, and in the imaging apparatus of this embodiment, the operator can select a still image mode, a moving image mode, a scene mode, and the like by moving the lever using the mode switching lever. It is configured as follows. Description of each mode is omitted because it is a known prior art.

  A plurality of rear operation button groups are arranged on the rear surface of the apparatus main body 101 and on the right side of the liquid crystal display device, and are operated while viewing menus and icons displayed on the liquid crystal display device. Display settings for changing settings of the device main unit 101, switching menus, switching on / off the liquid crystal display device, brightness of the liquid crystal display device, etc. It is a play button etc. which shift to. Since these operation buttons are operated while looking at the liquid crystal display device, it is arranged near the liquid crystal display device to improve user convenience.

  In addition, the center of the display area of the liquid crystal display device is arranged so as to coincide with the optical axis of the photographing optical system of the barrel unit 102 as much as possible, so that the photographer feels uncomfortable when determining the subject while looking at the liquid crystal display device. Can be eliminated.

  The apparatus main body 101 stores the extended lens barrel unit 102 by pressing the power button 113 again during a series of image capturing / reproducing operations and after the image capturing / reproducing operation is completed, and the power is turned off.

  Next, the structure of the bayonet type high-precision positioning mechanism of the image pickup apparatus of the present invention will be described. FIG. 5 is a diagram illustrating a state where the bayonet cap of the imaging apparatus according to the present invention is removed.

  In FIG. 5, reference numeral 116 denotes a bayonet cap, which is a cosmetic cap when a lens adapter (to be described later) is not attached. To change the bayonet cap attached state, ie, the state of FIG. 3 to the state of FIG. 5, the bayonet lock release button 112 is pushed in and the rotation lock is released, and the optical axis is rotated counterclockwise (this implementation) In the example, it is rotated 52 degrees). By doing so, the bayonet cap 116 comes off from the fitting portion and can be removed. The rotation angle up to the detachable state is determined by the number of fitting claws arranged on the apparatus main body 101 and the bayonet cap 116, and the number of fitting claws is three in this embodiment. Reference numeral 103c denotes a bayonet fitting claw protruding in an arc shape.

  When the bayonet cap 116 is removed, the bayonet coupling portion disposed in the bayonet front cover B portion (FIG. 2) is exposed. The bayonet cap 116 has three claw portions that fit into the 103c and project in an arc shape from the cylindrical part. The bayonet cap 116 is bayonet-coupled to the exterior member of the apparatus main body 101 by these engaging portions. Although details will be described later, the bayonet engaging portion provided in the front cover 103 plays an auxiliary role in the present invention.

  FIG. 6 is a developed perspective view showing a developed state of the lens adapter and the accessory lens of the apparatus of the present invention. In the figure, 104 is a lens adapter, and 105 is an accessory lens.

  When the accessory lens 105 is detachably attached to the imaging apparatus main body 101, the accessory lens 105 is generally attached to the imaging apparatus main body 101 via a lens adapter 104 having a coupling portion to the imaging apparatus main body 101. There are many. In such a system, a structure in which various accessory lenses 105 are attached to the tip of the lens adapter 104 by a screw mount system (two-body type of accessory lens and lens adapter) is adopted. On the other hand, some accessory lenses 105 are preliminarily provided with a connecting portion to the apparatus main body (accessory lens and one lens adapter type). However, the two-body type in which the accessory lens 105 can be attached to the imaging apparatus main body 101 via the lens adapter (relay cylinder) 104 is considered to carry a plurality of accessory lenses 105, and each one is reduced in size and is portable. Excellent in properties. Therefore, there are more cases that adopt this method. Further, as an advantage of the two-body type, even if the image pickup apparatus main body 101 is replaced, only the lens adapter 104 can be renewed and the accessory lens 105 can be used as an asset. In other words, there is an advantage of excellent versatility.

  By the way, the lens adapter 104 and the accessory lens 105 as a two-body type are configured to be positioned and fixed with high accuracy by a screw mount method. Therefore, the accuracy of attaching the accessory lens 105 to the imaging device main body 101 is considered to be equivalent to the accuracy of attaching the lens adapter 104 to the device main body 101. That is, even in the case of the two-pair type, if the lens adapter 104 is positioned and fixed to the imaging apparatus main body 101 with high accuracy, a high-definition image without the above-described optical axis deviation and no defects such as single blurring can be obtained. Can be imaged.

  In FIG. 6, like the bayonet cap 116, the lens adapter 104 is provided with three arc-shaped protrusions (contact portions) 104a inward from the tube portion. This portion engages with the arc-shaped protrusion 103c of the front cover 103 described above. Further, a threaded portion 104 c is provided on the inner peripheral portion of the other end of the lens adapter 104. Reference numeral 105a denotes a screw portion that can be screwed into the screw portion 104c. At least one optical lens is disposed inside the accessory lens 105. In this embodiment, a wide (wide angle) conversion lens is used for explanation, but in addition to this, various types of optical accessories such as a tele (telephoto) conversion lens, a macro (close-up) conversion lens, and various filters are prepared. ing. In the case of a filter, it may not be a lens. The accessory lens 105 and the lens adapter 104 are of a screw mount type that are coupled by screwing.

  Usually, the photographer mounts one interchangeable accessory lens 105 and lens adapter 104 in advance by a screw method. The integrated accessory lens 105 and lens adapter 104 (accessory lens unit) are quickly bayonet-coupled to the apparatus body and used in accordance with the shooting situation. In shooting situations that change from moment to moment, the bayonet connection can be easily attached and detached, so that the operability is good and there is no stress.

  As described above, it is described that the bayonet cap 116 is attached when the accessory lens 105 is not used. However, of course, even if the bayonet cap 116 is not attached, there is no functional problem in photographing.

  FIG. 7 shows a state in which the lens adapter 104 and the accessory lens 105 are screw-mounted and are bayonet-coupled to the apparatus main body.

  Next, a method for positioning the lens barrel unit 102 having the photographing optical system and the lens adapter 104 with high accuracy will be described in detail.

  FIG. 1 is a longitudinal sectional view in which a lens adapter 104 and an accessory lens 105 are mounted on the apparatus main body 101 and cut so as to pass through the optical axis. FIG. 2 is an enlarged view of a portion B in FIG.

  In FIG. 1, the front cover 103 is provided with a receiving portion that supports the lens adapter 104 in an auxiliary manner at a portion bulging from the front surface of the cover toward the subject. Among the components of the lens barrel unit 102, the outermost component is a lens barrel cover 106, and an arc-shaped groove is partially formed on the outer peripheral portion thereof as will be described in detail later.

  The accessory lens 105 described in the present embodiment is a wide conversion lens and includes three optical lenses.

  In FIG. 1, the apparatus main body 101 is in a power-on state, and the photographic optical system is extended from the apparatus main body 101. The lens barrel unit 102 is designed so as not to come into contact with the accessory lens 105 even if the lens barrel unit 102 is scaled and extended to the maximum extent.

  Here, as will be confirmed, in order to exhibit the optical performance sufficiently, the optical axis of the photographing optical system arranged in the lens barrel unit 102 and the optical axis of the optical lens system arranged in the accessory lens 105 are determined. It is positioned and matched with high accuracy.

  The positioning of the lens adapter 104 and the apparatus main body 101 will be described in detail with reference to FIG.

  An arc-shaped groove 106 b is disposed on the outer peripheral portion of the lens barrel cover 106 that is a component of the lens barrel unit 102. There are three arc-shaped grooves intermittently around the lens barrel cover 106. This groove will be described later with reference to FIG. An arc-shaped protruding portion (engaging portion) 104 d protruding inward from the lens adapter 104 is fitted into the groove, and the lens adapter 104 on which the lens barrel unit 102 and the accessory lens 105 are mounted is directly positioned. The lens barrel unit 102 and the lens adapter 104 are positioned and regulated at the same time in the thrust direction (optical axis direction) and radial direction (optical axis orthogonal direction) by the direct engagement of the groove 106b and the protrusion 104d. Thereby, the optical axis of the imaging optical system in which the lens barrel unit 102 is arranged and the optical axis of the lens optical system arranged in the accessory lens 105 connected to the lens adapter 104 can be positioned and matched with high accuracy. It becomes possible. However, the normal accessory lens 105 is not always smaller than the imaging device main body 101. That is, when the operator accidentally drops or hits the accessory lens 105 with the accessory lens 105 attached to the imaging apparatus main body 101, the external force is applied from the protruding portion 104d of the lens adapter 104 to the lens barrel unit. A large external force is applied to the lens barrel unit 102 through the groove 106d which is a part of the lens 102. The lens barrel unit 102 is very weak against external force because it is equipped with a driving unit such as an unwinding and sinking operation and an imaging optical system that becomes the liver of the imaging apparatus main body 101. Due to this external force, the operation becomes unstable, or in some cases, distortion or the like occurs in the imaging optical system, resulting in problems such as single blurring in the image to be captured.

  In order to avoid these problems, in the present invention, when an external force is applied to the accessory lens 105 and the lens adapter 104, the force is transmitted to the front cover 103 instead of the lens barrel unit 102. The arc-shaped projecting portion 104a projecting inward from the lens adapter 104 is disposed with a predetermined gap in the arc-shaped outer wall 103b, the arc-shaped projecting portion 103c, and the contacted portion 103d of the front cover 103. Yes. Since such a gap is provided, the lens adapter 104 is positioned on the lens barrel unit 102. If there is no gap, when the lens adapter 104 is fitted into the lens barrel unit 102, the projection 104a cannot be inserted well due to interference from the front cover 103. The lens adapter 104 can be positioned only on the lens barrel unit 102 because the gap is left. By positioning the lens adapter 104 only in the lens barrel unit 102, the optical axis of the imaging optical system in which the lens barrel unit 102 is arranged and the lens optical system arranged in the accessory lens 105 connected to the lens adapter 104. The optical axis can be positioned with high accuracy. Further, when an external force is applied to the accessory lens 105 and the lens adapter 104, the lens adapter 104 and the lens barrel unit 102 are slightly distorted and move integrally with the bayonet fitting. The protruding portion 104a of the lens adapter 104 abuts so that the external force is received by the outer wall 103b and the protruding portions 103c and 103d of the front cover 103. Thereby, an external force applied to the accessory lens 105 and the lens adapter 104 is transmitted to the front cover 103. As will be described in detail later, if the lens barrel unit 102 is held floating with respect to the structure, the accessory lens 105 and the lens adapter 104 can be connected to the lens barrel unit 102 without causing even a slight distortion. The lens barrel unit 102 moves integrally, and the projecting portion 104 a comes into contact with the receiving portions (outer wall 103 b, projecting portions 103 c and 103 d) of the front cover 103, and the applied external force can be transmitted to the front cover 103. The front cover 103 is fastened to a main chassis described later by fastening means (not shown).

  In the present embodiment, the front cover 103 is assumed to be made of resin, but specifically, engineering plastics such as PC, PC + ABS, and ABS are considered good. When the strength is insufficient, there is a method of strengthening by blending glass fiber or the like into the resin material. This configuration is also possible with a metal exterior such as a thixo mold or a magnesium alloy.

  Here, a bayonet type positioning mechanism of a conventional imaging apparatus according to the present invention will be described with reference to FIGS.

  FIG. 13 is a longitudinal cross-sectional view of a state in which the lens adapter and the lens accessory are attached to the image pickup apparatus by the bayonet method according to the conventional method, cut along the optical axis of the image pickup apparatus. FIG. 14 is a partially enlarged view of part A in FIG.

  In FIG. 13, reference numeral 501 denotes an imaging apparatus main body, which has a collapsible zoom lens barrel unit 502. An imaging optical system composed of a plurality of lens groups is arranged inside the lens barrel unit 502, and has a structure in which the magnification can be changed to the telephoto and wide-angle by changing the lens interval. Reference numeral 503 denotes a front cover that mainly covers the front side of the image pickup apparatus main body 501. Reference numeral 504 denotes a cylindrical lens adapter, which is coupled to the front cover 503 by a bayonet mount method to be described later. Reference numeral 505 denotes an accessory lens, in which a lens is disposed on a cylindrical member. As the accessory lens 505, various lenses such as a wide (wide angle) conversion lens, a tele (telephoto) conversion lens, and a macro (close-up) conversion lens are prepared. The accessory lens 505 and the lens adapter 504 are a screw mount type that is coupled by screwing. Here, in order to fully exhibit the optical performance, it is necessary to make the optical axis of the barrel unit 502 coincide with the optical axis of the accessory lens 505. That is, it is important to position the lens barrel unit 502 and the accessory lens 505 with high accuracy. Since the screw mount method is a method in which positioning and fixing are performed with high accuracy, an attachment error between the accessory lens 505 and the lens adapter 504 hardly occurs. In other words, accurately positioning and fixing the accessory lens 505 to the lens barrel unit 502 means positioning and fixing the lens adapter 504 to the lens barrel unit 502 with high accuracy.

  However, in the method of FIG. 13, it must be said that the front cover 503 is interposed for positioning the lens barrel unit 502 and the accessory lens 505 to reduce the positioning accuracy.

  In FIG. 14, reference numeral 506 denotes a lens barrel cover, which is a component of the lens barrel unit 502. The front cover 503 has a circumferential inner wall portion 503a for positioning the lens barrel unit 502, and contacts the outer diameter of the lens barrel cover 506 to position the front cover 503 and the lens barrel unit 502. ing. The front cover 503 has a bayonet coupling part, 503b is an arcuate outer wall, 503c is an arcuate protrusion, and 503d is a receiving part. On the other hand, the lens adapter 504 also has a portion for connecting the bayonet to the front cover 503, 504a has an arc-shaped protruding portion protruding inward from the cylindrical lens adapter 504, and 504b at the tip of the protruding portion is a protruding portion. It is the inner wall.

  FIG. 14 shows a state in which the lens adapter 504 is bayonet-coupled to the front cover 503. 503c does not exist at a predetermined position in which a lock release button (not shown) attached to the front cover 503 is pushed and the lens adapter 504 is rotated by a certain angle around the optical axis. Therefore, the conversion lens adapter 504 can be easily removed to the subject side.

  Here, consider the accuracy of the mounting position of the lens barrel unit 502 and the lens adapter 504. The outer peripheral wall 506a of the lens barrel cover 506, which is a component of the lens barrel unit 502, includes a circumferential inner wall 503a of the front cover, an inner wall 504b of the protruding portion of the lens adapter, and an arc-shaped outer wall of the front cover 503. 503b, respectively. In this manner, the front cover 503 is interposed between the lens barrel unit 502 and the lens adapter 504, and the positioning accuracy is lowered.

  FIG. 8 is a perspective view of the lens barrel unit 102 of the present invention. The lens barrel cover 106 is provided with an arcuate groove 106b. The groove 106 b is a holding portion that engages with the protruding portion 104 d and holds the lens adapter 104 and the accessory lens 105. When moved from the portion 106b in the counterclockwise direction in the figure, there are an inclined surface in the 106d radial direction (radial backlash direction) and an inclined surface in the 106e thickness direction (thrust backlash direction). This is a consideration for facilitating insertion of the engaging portion 104d of the lens adapter 104.

That is, when the protrusion 104d inserts the lens adapter 104 as shown by the two-dot chain line in the figure, the fitting is loose at the entrance and gradually becomes tighter.
In this figure, only one bayonet coupling portion 106f and one protruding portion 104d can be seen, but a total of three grooves are provided at intervals of 120 degrees around the center of the optical axis. Of course, the number is not limited to three, and other numbers may be used.

  FIG. 9 is a diagram illustrating a state in which the accessory lens 105 and the attached lens adapter 104 are attached to the imaging apparatus main body 101. The front cover 103 incorporates a lock plate 117 and a bayonet lock release button 112, and is always urged to a state as shown in the figure by a not-shown holding plate and a spring, and moves inward of the apparatus along the optical axis. It has a structure that can be pushed in. Further, the operations of the lock plate 117 and the bayonet lock release button 112 are interlocked. When the lock plate 117 is pushed in the direction toward the inside of the apparatus, the bayonet lock release button 112 is also retracted in the direction toward the inside of the apparatus. On the contrary, when the bayonet lock release button 112 is pushed in, the lock plate 117 is also retracted. When the lens adapter 104 is attached to the imaging apparatus main body 101, the arc-shaped protrusion 104a disposed on the lens adapter 104 pushes the lock plate 117 toward the inside of the apparatus. In this state, when the lens adapter 104 is not engaged with the lock plate 117, the lock plate 117 is pushed back by the spring biasing force to return to the position shown in the figure when the lens adapter 104 is not engaged with the lock plate 117. And the direction of rotation is locked. Thus, even if the lens adapter 104 is rotated in the direction opposite to the arrow, the protruding portion 104a is restricted by the lock plate 117 and cannot be rotated. When removing the lens adapter 104, the lens adapter 104 can be easily removed by pressing the bayonet lock release button 112 and rotating the lens adapter 104 in the direction opposite to the arrow.

  In the present embodiment, a method of bayonet-connecting the lens adapter 104 to the lens barrel cover 106 of the lens barrel unit 102 is shown. However, the present invention is not limited to this, and may be coupled to one component of the lens barrel unit 102 or may be other fitting means other than bayonet coupling.

  Next, a state in which the lens barrel unit 102 is held on the structure so as to be displaceable in the optical axis direction and the direction orthogonal to the optical axis will be described with reference to FIGS. 10, 11, and 12.

  FIG. 10 is an exploded perspective view showing a state in which the lens barrel unit 102 and the bush are assembled into the structure. FIG. 11 is a front view showing a state in which the lens barrel unit 102 and the bush are incorporated into the structure. FIG. 12 is a partial cross-sectional view taken along the line CC in FIG.

  In FIG. 10, reference numeral 118 denotes a main chassis made of metal, which is the main structure of the imaging apparatus (in this embodiment, a metal plate such as stainless steel is assumed, but it may be made of resin or the like). Further, bushes 119a and 119b made of an elastic body and stepped screws 120a and 120b, which are used when the lens barrel unit 102 is attached to the main chassis 118, are shown in a developed state.

  Next, details of each component will be described. The lens barrel cover 106, which is a component of the lens barrel unit 102, has a wing-shaped portion 106k protruding in a direction perpendicular to the optical axis, and there is a hole 106i for temporary positioning to the main chassis 118, 106j is arranged, and bush fitting portions 106g and 106h into which bushes 119a and 119b made of an elastic body are fitted are arranged. The bush fitting portions 106g and 106h have a through hole in the center, and bushes 119a and 119b made of an elastic body are inserted therein.

  The main chassis 118 is provided with shaft portions 118c and 118d for temporarily positioning the lens barrel unit 102, and tap portions 118a and 118b for fastening the stepped screws 120a and 120b.

  Next, the bushes 119a and 119b made of an elastic body will be described. The bushes 119a and 119b are made of silicon rubber or chloroprene rubber. When a force is applied to the elastic body, the elastic body is elastically deformed. In addition, although the rubber-type member is assumed in a present Example, you may be elastic bodies, such as a foaming body and a spring. The bushes made of the elastic bodies 119a and 119b are inserted into the bush fitting portions 106g and 106h of the lens barrel cover 106, and a hole through which the stepped screws 120a and 120b pass is provided in the center portion.

  In the assembly procedure, first, the bushes 119a and 119b made of an elastic body are lightly press-fitted into the bushing fitting portions 106g and 106h of the lens barrel cover 106 which is a component of the lens barrel unit 102. Next, the lens barrel unit 102 in which the bushes 119a and 119b are incorporated is attached to the main chassis 118 so that the holes 106i and 106j and the shafts 118c and 118d of the main chassis 118 are aligned. Finally, the bushes 119a and 119b and the wing portion 106k of the lens barrel unit are passed through the stepped screws 120a and 120b, and are fastened and fixed to the shaft portions 118c and 118d of the main chassis 118.

  FIG. 11 is a view showing a state after being assembled as described above.

  It can be seen that the hole portions 106i and 106j of the lens barrel cover 106 and the shaft portion 118c118d of the main chassis 118 are respectively inserted. The relationship between the shaft and the hole is a predetermined gap, and the main chassis 118 and the lens barrel unit 102 can freely move between the stepped screws 120a and 120b before they are fixed. is there. Even after the stepped screws 120a and 120b are fixed, the bushing 119a and 119b made of the above-described elastic body is elastically deformed in the lens barrel unit 102 with respect to the main chassis 118, so that the light is applied within a predetermined range. It can be displaced in a direction perpendicular to the axis.

  Next, a state in which the lens barrel unit 102 is displaceably fixed to the main chassis 118 via the bushes 119a and 119b made of an elastic body will be described with reference to the cross-sectional view of FIG.

  In FIG. 12, a wing portion 106k protruding from the lens barrel cover 106 in a direction orthogonal to the optical axis has a bush fitting portion 106g. The main chassis 118 has a tap portion 118a to which a stepped screw 120a is fastened. The stepped screw 120a is fastened to the tap portion 118a of the main chassis 118 with the bush 119a and the lens barrel cover 106 interposed therebetween. The stepped portion of the stepped screw 120a abuts on the main chassis 118, and the screw tightening is completed. That is, the bush 119a made of an elastic body is configured such that no stress due to screw tightening is applied in the tightening direction (parallel to the optical axis) (floating holding with respect to the main chassis of the lens barrel unit).

  In this figure, the bush 119a which consists of an elastic body has shown the state which is not deform | transforming. When an external force is applied to the accessory lens 105 or the lens adapter 104 and the external force is applied to the lens barrel unit 102, the bush 119a made of an elastic body freely deforms and absorbs the external force. The lens barrel unit 102 is appropriately moved in an optical axis direction and a direction perpendicular to the optical axis by an external force (floating holding), so that no distortion occurs in the lens barrel unit.

  Although detailed description is omitted, the holding of the lens barrel with respect to the main chassis 118 has the same configuration in the stepped screw 120b, the bush 119b, the hole portion 106j, and the tap portion 118b.

  In this embodiment, the lens barrel unit 102 is held by the main chassis 118 as the main structure so as to be displaceable in the direction perpendicular to the optical axis (floating holding) using the two rubber bushes 119a and 119b. . However, the number of rubber bushes 119a and 119b is not limited to two, and may be held floating using a member other than the rubber bush.

  As described above, the imaging apparatus main body 101 and the lens adapter 104 can be easily attached and detached. Also, a method for matching the optical axis between the lens group of the imaging optical system in the lens barrel unit 102 and the accessory lens 105 attached to the lens adapter 104 with high accuracy is to use the lens barrel unit 102 and the lens adapter 104. This is possible by positioning directly without intervening other parts. However, if direct positioning is performed, if an external force is applied to the accessory lens 105 or the lens adapter 104, the external force may be transmitted to the lens barrel unit 102. Therefore, a predetermined gap is provided between the lens adapter 104 and the front cover 103, and the fitting portion between the lens adapter 104 and the front cover 103 is provided. Therefore, the lens adapter 104 abuts against the front cover 103 only when a certain level of force is applied, and it is possible to transmit the external force to the front cover 103 without transmitting it to the lens barrel unit 102. Further, by holding the lens barrel unit 102 so as to be displaceable with respect to the main structure in the direction perpendicular to the optical axis and the optical axis, it is possible to adopt a configuration in which an external force is not transmitted to the lens barrel unit 102. 102 can be prevented from being damaged or broken.

A longitudinal sectional view of the lens adapter and accessory lens of Example 1 attached to the apparatus main body and cut so as to pass through the optical axis. Partial enlarged view of part 1B Schematic front perspective view of Example 1 External force front perspective view showing a state in which the power source of the apparatus of Example 1 is turned on and the lens barrel unit is extended. The figure which shows the state which removed the bayonet cap in Example 1. The expansion | deployment perspective view which shows the state which the lens adapter and the accessory lens expanded | deployed in Example 1. FIG. The figure which shows the state in which the lens adapter and the accessory lens in Example 1 are screw-mounted and are bayonet-coupled to the apparatus main body. The perspective view of the lens-barrel unit of Example 1 The figure which showed a mode that the accessory adapter and the lens adapter attached in Example 1 were mounted | worn with the imaging device main body An exploded perspective view showing a state in which the lens barrel unit and the bushing are incorporated into the structure in the first embodiment. The figure which showed a mode that the lens-barrel unit and the bush in Example 1 were integrated in the structure FIG. 11 is a partial cross-sectional view taken along a line CC in FIG. A longitudinal sectional view of a conventional lens adapter and accessory lens mounted on the main body and cut so as to pass through the optical axis 13 is an enlarged cross-sectional view of part A of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Image pick-up apparatus main body 102 Lens barrel unit 103 Front cover 103a Arc-shaped inner wall 103b Arc-shaped outer wall 103b Arc-shaped protrusion 103d Receiving part 103e Bayonet coupling part 104 Lens adapter 104a Arc-shaped protrusion 104b Projection inner wall 104c Screw Part 104d Arc-shaped protrusion 105 Accessory lens 105a Screw part 106 Lens tube cover 106a Arc-shaped outer wall 106b Arc-shaped groove 106c Notch part 106d Radially inclined surface 106e Thickness-inclined surface 106f Bayonet coupling part 106g, h bush Insertion part 106i, j Hole part 106k Wing part 110 Grip part 111 Strobe light emission window 112 Bayonet lock release button 113 Power button 114 Zoom lever 115 Shutter button 116 Bayonet cap 116a Claw part 117 Bock plate 118 Main chassis 118a, b Tap portion 118c, d Shaft portion 119a, b Bush 120a made of elastic body, b Stepped screw 501 Imaging device main body 502 Lens barrel unit 503 Front cover 503a Circumferential inner wall 503b Arc shape Outer wall 503c Arc-shaped protrusion 503d Receiving part 504 Lens adapter 504a Arc-shaped protrusion 504b Inner wall 505 of accessory part Accessory lens 506 Lens tube cover 506a Circumferential outer wall

Claims (5)

An accessory lens unit that is detachably attached to an imaging apparatus having a barrel unit including an imaging optical system and an imaging element, and an exterior member formed to expose the barrel unit,
An engaging portion that determines the position in the optical axis direction and the optical axis orthogonal direction by directly engaging the lens barrel unit;
An accessory having a contact portion that contacts the exterior member when an external force is applied to the accessory lens unit without contacting the exterior member when an external force is not applied to the accessory lens unit Lens unit.   The accessory lens unit according to claim 1, wherein the accessory lens unit includes a lens adapter having the engaging portion and the contact portion, and an accessory lens attached to the lens adapter.   The accessory lens unit according to claim 1, wherein the engaging portion is attached to the lens barrel unit by a bayonet mount method. An imaging device to which the accessory lens unit according to any one of claims 1 to 3 is detachably attached,
A lens barrel unit including an imaging optical system and an imaging element;
An exterior member formed to expose the lens barrel unit;
The lens barrel unit engages with the engaging portion to determine the position of the accessory lens unit in the optical axis direction and the optical axis orthogonal direction, and has a holding portion that holds the accessory lens unit,
The exterior member receives the contact of the contact portion when an external force is applied to the accessory lens unit without receiving the contact of the contact portion when an external force is not applied to the accessory lens unit. An imaging device comprising a portion. A main chassis for holding the lens barrel unit;
The imaging apparatus according to claim 4, wherein the barrel unit is held on the main chassis so as to be displaceable in an optical axis direction of the photographing optical system and a direction orthogonal to the optical axis.