JP4944821B2 - Lens unit and camera - Google Patents

Description

  The present invention relates to a lens unit that forms a bent lens barrel by bending an optical path using a deflecting optical element such as a mirror or a prism, and more particularly, a fixed deflecting optical element that bends an optical path of a plurality of lenses and lenses. And a lens unit including a lens barrel in which at least one lens is disposed closer to the object side than the deflection optical element at the time of photographing, and a camera using such a lens unit.

  In recent years, in compact cameras and the like, it is becoming common to use a zoom lens as a photographing lens. Such a zoom lens tends to have a large lens barrel. However, in order to improve portability, a camera including the lens barrel is required to be downsized, particularly thin. For this reason, many techniques for thinning the camera have been proposed. For example, as a means for reducing the thickness of a camera, zooming is performed by moving a plurality of lens groups to a required position using a rotating cylinder and a cam groove provided in the rotating cylinder, and changing the interval between the groups. A retractable lens barrel that shortens the length of the lens barrel by stacking tubes with different diameters to hold the lens so that the distance between each group is as small as possible during shooting. Is used. Furthermore, the length of the long side or short side of the camera body is used by bending the optical axis by inserting a deflecting optical element such as a mirror or prism that reflects and deflects the optical path in the middle of the optical axis of the lens barrel. Many bending lens barrels have been proposed that secure the optical path length and reduce the overall thickness of the camera. In particular, such a bent lens barrel can be substantially constituted only by the thickness of the deflecting optical element and the lens disposed on the front side thereof, and is effective in reducing the thickness.

In general, a bending lens barrel includes a deflection optical element that bends an optical path, a fixed cylinder that holds the deflection optical element, a first lens group that is closer to the object side than the deflection optical element, and more than the deflection optical element. One or more moving lens groups arranged on the image plane side and held so as to be movable on the optical axis, a shutter, and a diaphragm are included. Since the first lens group is a fixed lens group, the first lens group is fixedly held by the fixed cylinder, the moving lens group is movably held by the fixed cylinder, and the shutter and the diaphragm are The fixed cylinder is fixedly or movably held. Zooming and focusing are performed by moving the movable lens group. In some cases, a fixed lens is also provided on the image plane side. A subject image condensed by an imaging lens such as the first lens group and the moving lens group is formed on an imaging element such as a CCD and photographed.
When a camera is configured using such a bent lens barrel, a barrier member that shields the front of the lens surface of the first lens closest to the object in the first lens group, or a liquid crystal monitor on the back side of the camera body Therefore, the thickness of the camera is mainly determined by the barrier, the lens group, the deflection optical element, the fixed cylinder, and the liquid crystal monitor. These are the minimum configurations that determine the thickness of the camera, but in recent years, various configurations have been proposed in order to achieve further thinning.

For example, in Patent Document 1 (Japanese Patent Application Laid-Open No. 2007-86141), a prism is used as a reflecting member corresponding to a deflecting optical element, and a lens group including the prism rotates around a rotation axis, and is taken from a camera. The structure which accommodates this protrusion part in a camera is disclosed. That is, in this configuration, the lens on the object side of the prism protrudes from the camera at the time of shooting, but when not shooting, the prism and the object side lens are integrally rotated by the rotation shaft, and the lens portion on the object side is It is housed in the camera so that the thickness of the camera is reduced when not shooting. However, in this configuration, since the prism is movable, it is required that the repetitive positional accuracy of the prism be sufficiently high. This is because a change in the tilt angle of the prism causes a double angle change in the optical axis reflected and deflected.
As another configuration for reducing the thickness of the camera, for example, in Patent Document 2 (Japanese Patent Laid-Open No. 2006-259585), a prism as a reflective optical element corresponding to a deflecting optical element is retracted to the imaging element side when not photographing. In addition, a configuration is disclosed in which the lens group on the object side ahead of the prism is retracted and accommodated in the vacant space, thereby reducing the thickness of the camera during non-shooting. Japanese Patent Application Laid-Open No. 2006-106071 discloses a configuration in which the lens group on the object side is housed in a space that is vacated by rotating the reflecting mirror around the rotation axis and folding it. In these configurations of Patent Document 2 and Patent Document 3, as in the case of Patent Document 1 described above, since the deflection optical elements such as prisms and mirrors are movable, the deflection optical elements can be moved with extremely high positional accuracy. Will be required.

  In order to solve the problems in the configurations of Patent Document 1 to Patent Document 3 described above, a configuration in which a prism as a deflection optical element is fixed and a lens on the object side of the prism is moved to be retracted when not photographing is considered. . With such a configuration, it is possible to achieve a lens barrel that is thin and has high positional accuracy as a camera, because the thickness at the time of non-photographing is defined by the thickness due to the prism.

JP 2007-86141 A JP 2006-259665A JP 2006-106071 A

As described above, if the prism as the deflecting optical element is fixed and the lens on the object side of the prism is moved and retracted at the time of non-photographing, the thickness at the time of non-photographing is the thickness caused by the prism. The lens barrel that is defined and solves the problems in the configurations of Patent Documents 1 to 3 and that is thin as a camera and has high positional accuracy can be obtained. However, in this case, if the prism is exposed to the outside after the lens is retracted, dirt and dust are likely to adhere to the prism, which is not preferable.
The present invention has been made in view of the above-described circumstances, and can prevent and prevent dirt and dust from adhering to an optical system such as a lens and a deflecting optical element, and can ensure thinness when not photographing. It is an object of the present invention to provide a lens unit and a camera equipped with such a lens unit.
The purpose of claim 1 of the present invention, the thinness in the non-shooting effectively ensured, moreover make it possible to prevent adhesion of dirt and dust in the optical system, in particular, dirt or dust on the optical system A lens unit that enables a protective member that protects and prevents the adhesion of the lens to be stably moved back and forth in the optical axis direction on the object side of the optical axis bent by the deflecting optical element using a simple configuration. It is to provide.

According to the second aspect of the present invention, in particular, a protective member for protecting and preventing dirt and dust from adhering to the optical system is moved in conjunction with the movement of the retracting lens without providing an independent drive source, and control is performed. Is to provide a lens unit that is simple and does not cause malfunction such as interference.
The purpose of claim 3 of the present invention is to simplify the shape of the protective member that protects against dirt and dust from being deposited on the optical system in particular, effectively reducing the thickness during non-photographing and degrading the performance. It is an object of the present invention to provide a lens unit that can protect an optical system without causing it.
An object of claim 4 of the present invention is to provide a camera that can effectively protect an optical system while ensuring thinness.
An object of claim 5 of the present invention is to provide a camera that can realize high portability, in particular, without the lens unit protruding from the outer shape during non-photographing.

In order to achieve the above-described object, the lens unit according to the present invention described in claim 1
An optical system including a plurality of lenses and optical elements, and a protective member for protecting the optical system,
The optical system sequentially from the object side,
A first lens group composed of at least one lens;
A deflection optical element that bends the optical axis of the optical system;
A second lens group composed of at least one lens ;
Is arranged,
The deflecting optical element is fixedly arranged at the same position both during shooting and during non-shooting,
The first lens group is arranged so that the optical axis of the first lens group coincides with the optical axis of the optical system at the time of photographing, and at least one of the first lens group at the time of non-photographing. The retractable lens is used as a retractable lens, and the retractable lens is moved and retracted so as to be out of the optical axis of the optical system,
The protective member is disposed further on the object side of the first lens group, and moves to a space generated by moving the retractable lens from the optical axis of the optical system when not photographing .
The protective member is fixed to a holding member for holding the protective member, and the holding member is a guide member arranged in parallel to the optical axis on the object side of the optical axis bent by the deflecting optical element. A fitting portion for fitting is provided, and the protection member is movable in parallel with the optical axis on the object side .

Lens unit according to the present invention described in 請 Motomeko 2,
The holding member is urged toward the object side of the optical axis by an elastic member, and an engagement receiving portion that engages with the engaging portion provided in the retracting lens during the retracting movement of the retracting lens. Have
When the retracting lens is retracted, the retracting lens is engaged with the engaging receiving portion of the retaining member, so that the retaining member is moved in the direction opposite to the object side along the optical axis on the object side. It is characterized by being moved to.
The lens unit according to the present invention described in claim 3 is:
The protective member is formed using a parallel plate that transmits light.

A camera according to the present invention described in claim 4
An imaging optical system is configured using the lens unit according to any one of claims 1 to 3 .
A camera according to the present invention described in claim 5 is
The non-photographing means that the protective member is located on the same side as the object side surface of the camera body or behind it, and at the time of photographing, the protective member is located closer to the object side than during non-photographing. It is a feature.

According to the present invention, a lens unit capable of protecting and preventing dirt and dust from adhering to an optical system such as a lens and a deflecting optical element, and ensuring the thinness when not photographing, and such a lens unit. Can be provided.
That is, according to the lens unit of claim 1 of the present invention,
An optical system including a plurality of lenses and optical elements, and a protective member for protecting the optical system,
The optical system sequentially from the object side,
A first lens group composed of at least one lens;
A deflection optical element that bends the optical axis of the optical system;
A second lens group composed of at least one lens ;
Is arranged,
The deflecting optical element is fixedly arranged at the same position both during shooting and during non-shooting,
The first lens group is arranged so that the optical axis of the first lens group coincides with the optical axis of the optical system at the time of photographing, and at least one of the first lens group at the time of non-photographing. The retractable lens is used as a retractable lens, and the retractable lens is moved and retracted so as to be out of the optical axis of the optical system,
The protective member is disposed further on the object side of the first lens group, and moves to a space generated by moving the retractable lens from the optical axis of the optical system when not photographing .
The protective member is fixed to a holding member for holding the protective member, and the holding member is a guide member arranged in parallel to the optical axis on the object side of the optical axis bent by the deflecting optical element. By including a fitting portion to be fitted, and enabling the protective member to move in parallel with the optical axis on the object side ,
The thinness in the non-shooting effectively ensured, moreover Ri Do can prevent adhesion of dirt and dust in the optical system, in particular, the protective member for protecting prevent adhesion of dirt or dust on the optical system Using a simple configuration, it becomes possible to stably move back and forth in the optical axis direction on the object side of the optical axis bent by the deflecting optical element.

According to the lens unit of claim 2 of the present invention,
The holding member is urged toward the object side of the optical axis by an elastic member, and an engagement receiving portion that engages with the engaging portion provided in the retracting lens during the retracting movement of the retracting lens. When the retractable lens is retracted, the retracting lens engaging portion engages with the engaging receiving portion of the retaining member, so that the holding member is moved along the optical axis on the object side. By moving in the opposite direction to the side,
In particular, without providing an independent drive source, a protective member that protects dirt and dust from being attached to the optical system is moved in conjunction with the movement of the retractable lens, making control simple and preventing malfunctions such as interference. It will not be generated.

According to the lens unit of claim 3 of the present invention,
By forming the protective member using a parallel plate that transmits light,
In particular, protect the optical system without degrading performance by simplifying the shape of the protective member that protects and prevents dirt and dust from adhering to the optical system, effectively reducing the thickness when not shooting. Is possible.
Furthermore, according to the camera of claim 4 of the present invention,
By configuring the imaging optical system using the lens unit according to any one of claims 1 to 3 ,
In particular, the optical system can be effectively protected while ensuring the thinness.

According to the camera of claim 5 of the present invention,
When the non-photographing, the protective member is located on the same side of the object side surface of the camera body or behind it, and at the time of photographing, the protective member is located on the object side than the non-photographed ,
In particular, the lens unit does not protrude from the outer shape during non-photographing, and high portability can be realized.

Hereinafter, based on an embodiment of the present invention, a lens unit and a camera of the present invention will be described in detail with reference to the drawings.
1 to 3 show a configuration of a main part of a lens barrel part of a lens unit according to an embodiment of the present invention. FIG. 1 is a perspective view of a main part of the lens barrel, respectively. 2 is a front view of the main part of the lens barrel, and FIG. 3 is an exploded perspective view of the main part of the lens barrel. FIG. 4 is a schematic partial cross-sectional side view showing a configuration of an optical system used in the lens barrel of FIGS. 1 to 3. FIGS. 5 to 7 show the operation of the retractable lens group in the lens barrel of FIGS. 1 to 3, respectively. FIG. 5 is for shooting, FIG. 6 is in the middle of storage, and FIG. It is a perspective view which shows the state at the time of accommodation. FIGS. 8 and 9 show in detail the operational positional relationship between the retractable lens group and the prism as the deflecting optical element. FIG. 8 shows a state during photographing, and FIG. 9 shows a state during non-photographing storage. It is principal part sectional drawing.
10 and 11 show the configuration of the main part of the lens unit including the protective cover. FIG. 10 is a perspective view in a photographing state, and FIG. 11 is a perspective view in a stored state. 12 shows in more detail the configuration in the photographing state of the main part of the lens unit including the protective cover shown in FIG. 10, (a) is a front view seen from the front (object side), (b). These are arrow sectional views along the AA line.

FIG. 13 shows in more detail the configuration of the main part of the lens unit including the protective cover shown in FIG. 11 in the housed state. FIG. 13A is a front view seen from the front, and FIG. It is arrow sectional drawing which follows the -B line. FIG. 14 is a perspective view of the main part of the lens unit including the protective cover in a shooting state when viewed from the back (photographer side). FIG. 15 shows the configuration of the main part of the lens unit including the protective cover in the middle of storage, (a) is a perspective view seen from the back, and (b) shows the C part in (a). It is detail drawing which expands and shows. FIG. 16 is a perspective view of the configuration of the main part of the lens unit including the protective cover as viewed from the back.
FIG. 17 is an exploded perspective view of a camera as a digital camera, for example, in which a lens unit including the lens barrel shown in FIGS. 1 to 16 is incorporated. 18 and 19 show the external configuration of a camera in which the lens unit described above is incorporated, and are a perspective view in a shooting state and a perspective view in a storage state, respectively. 20 and 21 show the internal configuration of the camera in which the above-described lens unit is incorporated, and are a cross-sectional view in a shooting state and a cross-sectional view in a storage state, respectively.

First, the main part of the lens barrel in the lens unit according to one embodiment of the present invention shown in FIGS. 1 to 3 and the optical system shown in FIG. 4 will be described.
The optical system in the lens barrel shown in FIGS. 1 to 3 includes, as shown in detail in FIG. 4, the first lens group G1, the prism PR, the second lens group G2, and the third lens from the object side (upper side in the figure). The group G3, the aperture / shutter unit AS, the fourth lens group G4, the fifth lens group G5, the sixth lens group G6, the seventh lens group G7, the optical filter OF, and the imaging element IS are sequentially arranged along the optical axis. Configured.
In FIG. 4, the first lens group G1 is composed of one or more lenses as a retracting lens group disposed closest to the object side, and receives light from the object side. The first lens group G1 is fixedly arranged in the photographing state, and retracts out of the optical path in the housed state when not photographing. The prism PR is used as a deflecting optical element that reflects and deflects incident light. In this case, the incident light is deflected by 90 degrees and the optical axis is bent to form a bent optical path. The second lens group G2 includes one or more lenses and is fixedly disposed on the image plane side of the prism PR. The third lens group G3 is a movable lens group that includes one or more lenses, for example, three lenses, and is movable along the optical axis.

The aperture / shutter unit AS has an aperture function for narrowing the light beam on the optical path and a shutter function for opening and closing the optical path. The fourth lens group G4 is composed of one or more lenses, for example, one lens, and is a movable lens group movable along the optical axis. The fifth lens group G5 is composed of one or more lenses, for example, three lenses, and is a movable lens group that is movable along the optical axis.
The sixth lens group G6 is composed of one or more lenses, for example, two lenses, and is a movable lens group movable along the optical axis. The seventh lens group G7 is composed of one or more lenses, for example, one lens, and is fixedly disposed. The optical filter OF is a filter that cuts infrared rays, and may also have a function of a low-pass filter. The imaging element IS is composed of an image sensor such as a CMOS (complementary metal oxide semiconductor) or a CCD (charge coupled device), and converts an optical image formed on the light receiving surface into electronic image data.
Note that the deflecting optical element forms a bent optical path by reflecting or refracting incident light to bend or refract the incident light. A mirror or the like may be used as the deflecting optical element instead of the prism PR. good.

The third lens group G3, the fourth lens group G4, and the fifth lens group G5 are variable power lens groups, and can be moved to required positions on the optical axis by a driving mechanism (not shown). The focal length can be changed by moving the third lens group G3 to the fifth lens group G5.
The aperture / shutter unit AS may move, for example, integrally with the fourth lens group G4, but may move alone or hinder the operation of the third lens group G3 to the fifth lens group G5. Otherwise, it can be fixed. The sixth lens group G6 is a focusing lens group, and moves on the optical axis by a driving device (not shown) to perform a focusing operation so as to form a subject optical image on the light receiving surface of the image sensor IS. Do. By the operation of these lens groups, a zooming operation and a focusing operation can be performed at the time of photographing.
The lens barrel shown in FIGS. 1 to 3 includes a lens holding frame 11, a main shaft 12, a fixed frame 13, a sub shaft 14, a compression torsion spring 15, a lead screw 16, a pulse motor 17, and a nut member 18.

The first lens group G1, which is a retracting lens group, is held by the lens holding frame 11. The lens holding frame 11 has a cylindrical sleeve portion 11 a into which a main shaft 12 that is a guide shaft is inserted, and enables rotation around the main shaft 12 and sliding movement along the main shaft 12. That is, the main shaft 12 is fixed to the fixed frame 13 at both ends, whereby the first lens group G1 is movable in a direction along the main shaft 12. The lens holding frame 11 is provided with a sub guide pin 11b on the opposite side of the sleeve portion 11a across the first lens group G1. An auxiliary shaft 14 is fixed to the fixed frame 13 on the opposite side of the main shaft 12 with the first lens group G1 interposed therebetween. The sub guide pin 11b is disposed so as to be sandwiched between the sub shaft 14 and the fixed frame 13 during photographing.
A compression torsion spring 15 is disposed between the fixed frame 13 and the sleeve portion 11 a of the lens holding frame 11 on the lower end side of the main shaft 12 in the figure. The compression torsion spring 15 functions as a compression spring that presses the lens holding frame 11 upward in the figure along the main axis direction, and a direction in which the lens holding frame 11 is pressed toward the sub shaft 14 around the main shaft 12 toward the sub shaft 14. It also has the function of a torsion spring that generates a rotational force to rotate it. The compression torsion spring 15 is fixed to the fixed frame 13 on the side opposite to the lens holding frame 11 side in the direction of the main shaft 12, and the lens holding frame 11 side is provided with a spring engagement portion 11d (see FIG. 8 and FIG. 9).

The lens holding frame 11 is urged toward the prism PR side of the fixed frame 13 along the direction of the main shaft 12 by the compression repulsive force of the compression torsion spring 15, and the lens holding frame 11 pushes the sub guide pin 11 b to the sub guide pin by the torsion force. The shaft 14 is biased toward the side that presses it. The fixed frame 13 is formed with a receiving surface 13a (see FIG. 3) on which the lens holding frame 11 is locked in the photographing state, so that the first lens group G1 is stabilized on the surface where the optical axes intersect perpendicularly. The position can be secured. By engaging the sub guide pin 11b with the sub shaft 14 by the torsional force, the tilt of the optical axis of the first lens group G1 can be stabilized.
Further, the receiving surface 13d of the fixed frame 13 facing the auxiliary shaft 14 with the auxiliary guide pin 11b interposed therebetween is provided with a minimal gap from the auxiliary guide pin 11b, so that the user inadvertently makes the first lens group. Even if it contacts G1, the amount of movement is small, and if it is released from the contact, it can return to its original position.
A pulse motor 17 to which a lead screw 16 is directly connected is fixed to the fixed frame 13, and the lead screw 16 is disposed in parallel with the main shaft 12. In other words, the main shaft 12, the sub shaft 14, and the lead screw 16 are arranged in parallel to each other perpendicular to the plane including the optical axis bent by the prism PR. A nut member 18 is screwed into the lead screw 16, and a rotation-preventing protrusion 18 a of the nut member 18 is fitted in a straight guide groove 13 b formed in the fixed frame 13 in parallel with the lead screw 16 and the main shaft 12. ing. As a result, the nut member 18 can be moved straight along the lead screw 16 by the rotation of the lead screw 16.

The lens holding frame 11 has a nut engaging portion 11c (see FIG. 2) with which the engaging protrusion 18b of the nut member 18 is engaged, and these are engaged by the compression repulsive force of the compression torsion spring 15. The nut engaging portion 11c of the lens holding frame 11 is formed by two substantially fan-shaped plate-like projecting portions facing each other in parallel with an appropriate interval in the direction of the main shaft 12. The engaging protrusions 18b of the nut member 18 are engaged with each other with a slight play in the direction along the main shaft 12 (see FIG. 2). Thus, the lens holding frame 11 can be moved on the main shaft 12 according to the rotation of the pulse motor 17.
Further, on the side of the fixed frame 13 far from the prism PR, that is, in the lower side of the figure, there is provided a retracting cam portion 13c that engages when the lens holding frame 11 moves and guides it in the back direction. When the lens 11 moves, the lens holding frame 11 engages with the retracting cam portion 13c, the lens holding frame 11 rotates against the torsional force of the compression torsion spring 15, and the sub guide pin 11b rotates to the sub shaft. 14 apart. When the nut member 18 moves to a predetermined position, the lens holding frame 11 is retracted into a retracting space formed in the fixed frame 13 (see FIGS. 7 and 9).

In this embodiment, the lead screw 16 is directly connected to the pulse motor 17 which is a drive source. However, a gear or the like may be interposed between the pulse motor 17 and the lead screw 16. The drive source may be a DC (direct current) motor instead of the pulse motor 17, or a linear motor may be used instead of the pulse motor 17 and the lead screw 16.
5, 6, and 7 show the state in which the lens holding frame 11 moves from the shooting state to the retracted state. FIG. 5 shows the shooting state (during shooting), FIG. FIG. 7 shows the retracted and stored state (when stored).
FIGS. 8 and 9 are schematic views showing a part of the retracted and retracted state during photographing and during non-photographing as seen from the side. Since the main shaft 12, the lead screw 16, the pulse motor 17 and the sub shaft 14 are arranged on the side of the prism PR, the lens barrel is disposed on the object side with respect to the object side surface of the prism PR when housed. There is no object to be positioned, and the lens holding frame 11 does not protrude rearward (downward in the drawing) from the prism PR when retracted. Therefore, the thickness of the lens barrel at the time of storage is determined by the thickness dimension of the prism PR. , The smallest dimension.

The perspective view shown in FIG. 10 shows a configuration in the photographing state of the main part of the lens unit including the above-described lens barrel and the protective cover. The perspective view shown in FIG. 11 is the same lens unit as FIG. The structure in the accommodation state of the principal part is shown. 12A is a front view of the configuration of the main part of the lens unit including the protective cover shown in FIG. 10 in the photographing state, as viewed from the front (object side), and FIG. 12B is an arrow along the line AA. This is shown in more detail by a cross-sectional view. FIG. 13: (a) The front view which looked at the structure in the accommodation state of the principal part of the lens unit containing the protective cover shown in FIG. 11 from the front, and (b) The arrow sectional view which follows the BB line Shows in more detail. FIG. 14 is a perspective view of the main part of the lens unit including the protective cover in a shooting state when viewed from the back (photographer side). FIGS. 15A and 15B show the configuration of the main part of the lens unit including the protective cover in the middle of storage, with (a) a perspective view seen from the back, and (b) a detailed view showing an enlarged C part. FIG. 16 is a perspective view of the configuration of the main part of the lens unit including the protective cover in the housed state as viewed from the back.
10 to 16, in addition to a part of the configuration of FIGS. 1 to 9 described above, a protective glass 21, a protective cover 22, a first protective cover guide shaft 23, a second protective cover guide shaft 24, and A compression spring 25 is shown.

  As shown in FIGS. 10 and 11, at the time of photographing, a protective glass 21 made of, for example, transparent parallel flat glass is disposed on the object side of the first lens group G1 that is a retractable lens. The protective glass 21 is held by a protective cover 22 having a box shape so as not to interfere with the locus of the first lens group G1 retracting. The protective glass 21 is disposed in a window portion formed on the protective cover 22 corresponding to the position of the imaging optical path at the time of photographing, and the imaging light flux at the time of photographing is transmitted through the protective glass 21. . These protective glass 21 and protective cover 22 constitute a protective member that protects the optical system. The protective cover 22 is disposed in parallel to the optical axis on the object side of the bent surface of the optical axis bent by the prism PR, and the first and second protective cover guides as guide members fixed to the fixed frame 13. The shafts 23 and 24 are provided with first and second fitting portions 22a and 22b, respectively, into which the shafts 23 and 24 are slidably fitted. In this case, the first fitting portion 22 a is formed in a sleeve shape through which the first protective cover guide shaft 23 is inserted, and the second fitting portion 22 b grips the second protective cover guide shaft 24. It has a shape.

With such a configuration, the protective cover 22 can move parallel to the optical axis on the object side with respect to the folding surface. In addition, the optical system such as the prism PR and the first lens group G1 is covered and protected by the protective glass 21 and the protective cover 22, and does not come into contact with the outside. Due to such a configuration, dust, dirt, and the like hardly adhere to the optical system such as the prism PR and the first lens group G1. In this configuration, instead of the first and second protective cover guide shafts 23 and 24 and the first and second fitting portions 22a and 22b, a protruding key and a key groove fitted to the key are used. You may use the structure which controls parallel movement.
Next, the operation of the first lens group G1 from the photographing state to the housed state and the protective member made of the protective glass 21 and the protective cover 22 will be described in more detail with reference to FIGS. In FIG. 12 for explaining in more detail the configuration of the main part of the lens unit including the protective cover shown in FIG. 10 in the photographing state, (a) shows a front view seen from the object side, and (b) shows The arrow sectional drawing which follows the AA line is shown.

Further, in FIG. 13 for explaining in more detail the configuration of the main part of the lens unit including the protective cover shown in FIG. 11 in the housed state, (a) shows a front view seen from the object side, (b ) Shows an arrow cross-sectional view along the line BB. FIG. 14 shows a perspective view of the configuration of the main part of the lens unit including the protective cover 22 in a shooting state as viewed from the back (photographer side). FIG. 15 shows a configuration of the main part of the lens unit including the protective cover in the middle of storage, (a) is a perspective view seen from the back, and (b) is a C part in (a). It is detail drawing which expands and shows. FIG. 16 is a perspective view of the configuration of the main part of the lens unit including the protective cover in the housed state as viewed from the back.
12 to 16, the protective cover 22 is urged toward the object side by the compression spring 25.
The lens holding frame 11 of the first lens group G1 is provided with an engaging protrusion 11e that engages with the protective cover 22 when retracted. The protective cover 22 has an engagement receiving portion that engages with the engaging protrusion 11e. 22c is provided. When the lens holding frame 11 of the first lens group G1 retreats and engages with the retraction cam portion 13c of the fixed frame 13 and starts rotating around the main shaft 12, the engagement protrusion 11e of the lens holding frame 11 is fixed. Engages with the engagement receiving portion 22 c of the frame 22.

As the lens holding frame 11 of the first lens group G1 rotates, the protective cover 22 is moved to the prism PR side according to the protective cover guide shafts 23 and 24. By this operation, the protective cover 22 is housed in the housing position using the lens holding frame 11 of the first lens group G1, which is a retracting lens group, as a drive source. Conversely, when the lens holding frame 11 of the first lens group G1 moves to the photographing state, the protective cover 22 is moved by the repulsive force of the compression spring 25 as the lens holding frame 11 of the first lens group G1 rotates. When the fitting portions 22a and 22b of the protective cover 22 are engaged with the fixed frame 13 at the ends of the guide shafts 23 and 24, the position of the protective cover 22 is fixed. If the lens holding frame 11 of the first lens group G1 moves further and is positioned in front of the prism PR, the photographing is possible.
That is, at the time of photographing, the lens holding frame 11 is positioned at the upper end of the main shaft 12 in FIG. 1 and the like by the nut member 18 driven by the pulse motor 17 through the lead screw 16. At this time, the lens holding frame 11 is disposed at a predetermined position on the optical axis on the object side of the prism PR by pressing the sub guide pin 11b against the sub shaft 14 by the compression torsion spring 15. Further, at the time of storage, the lens holding frame 11 is positioned below the main shaft 12 by the nut member 18 driven by the pulse motor 17 via the lead screw 16.

At this time, the lens holding frame 11 is rotated against the compression torsion spring 15 by the retraction cam portion 13 c of the fixed frame 13, the sub guide pin 11 b is separated from the sub shaft 14, and the lens holding frame 11 is moved to the fixed frame 13. Retreat into the formed retreat space. Note that the nut engaging portion 11c (see FIG. 2) of the lens holding frame 11 has a substantially sector shape, because the engagement with the engaging protrusion 18b of the nut member 18 is released in the rotation range of the lens holding frame 11. This is to prevent it from occurring.
The lens unit according to the present invention described above is used by being incorporated in an imaging apparatus such as a camera. The exploded perspective view of FIG. 17 schematically shows the configuration of a digital camera as a camera incorporating the above-described lens unit. The perspective view of FIG. 18 shows the external configuration of the digital camera of FIG. 17 in the shooting state, and the perspective view of FIG. 19 shows the external configuration of the digital camera of FIG. The cross-sectional view of FIG. 20 shows the internal configuration of the digital camera of FIG. 17 in the shooting state, and the cross-sectional view of FIG. 21 shows the internal configuration of the digital camera of FIG.

The digital camera shown in FIGS. 17 to 21 includes a lens unit 31, a circuit board 32, a capacitor 33, a battery 34, a display device 35, a memory card 36, a flash 37, a front cover 38, and a rear cover 39. In this case, the lens unit 31 includes the protective glass 21, the protective cover 22, and the lens barrel as described above.
The lens unit 31 includes the lens barrel configured as described above, the protective glass 21, and the protective cover 22, and the same parts as those in FIGS. Detailed description is omitted. The circuit board 32 is a printed wiring board on which electrical components for performing image processing, camera control, and the like are arranged and mounted. The capacitor 33 is used as a power source for accumulating the charge of the battery 34 as a power source and causing the strobe 37 to emit light. The battery 34 is a power source for the camera, and supplies power for driving the various parts of the camera, such as the lens unit 31, the circuit board 32, the capacitor 33, the display device 35, the memory card 36, and the flash 37. The display device 35 is configured using an LCD (Liquid Crystal Display) or the like, and displays information related to an operation for operating the camera, a captured / stored image, and the like according to the operation or state.

The memory card 36 is a general-purpose type or a dedicated type recording medium equipped with a flash memory that stores recording data including captured images and other information. When the flash 37 is requested or instructed to emit light, the charged light of the capacitor 33 is discharged to illuminate the subject. The front cover 38 and the rear cover 39 constitute an exterior cover of the camera, a so-called camera body, and include the lens unit 31, the circuit board 32, the capacitor 33, the battery 34, the display device 35, the memory card 36, the flash 37, and the like described above. Retain / store. In this case, as described above, the protective glass 21 and the protective cover 22 of the lens unit 31 cover and protect the optical system such as the first lens group G1 and the prism PR, and can move forward and backward along the thickness direction of the camera body. When shooting, the front side of the protective cover 22 is retracted toward the photographer side and positioned behind the front cover 38 of the camera body or behind it. , Eliminate protrusions and keep thin.
The digital camera equipped with the lens unit 31 according to this embodiment has a protective glass 21 and a protective cover 22 in a non-photographing state in which the power is not turned on, that is, in a retracted state, as can be seen from the sectional view of FIG. The object side surface, that is, the front surface, forms the same surface as the front surface of the front cover 38 that forms the camera body, or enters inward from the front surface of the front cover 38.

When the power is turned on, as can be seen from the cross-sectional view of FIG. 20 and the like, the protective cover 22 protrudes toward the object side as the lens holding frame 11 of the first lens group G1 moves, and the lens holding frame of the first lens group G1. 11 is positioned in front of the prism PR and the preparation for photographing is completed. At this time, the protective cover 22 should abut against a part of the lens holding frame 11 of the first lens group G1 so as not to interfere with the first lens group G1 and the like even if the user carelessly presses. preferable. In this embodiment, the sub-guide pin 11b of the lens holding frame 11 is abutted. If the protective cover 22 is pressed, the protective cover 22 is used as the lens holding frame of the first lens group G1. 11 is in contact with the root of the sub guide pin 11b and the sub guide pin 11b engages with the fixed frame 13, so that the protective cover 22 does not move any further. At this time, it is desirable that the protective glass 21 does not come into contact with the first lens group G1.
In such a camera, in the shooting state, the first lens group G1 is in an appropriate shooting state and is protected by the protective glass 21, and in the non-shooting state, the front surface of the front cover 38 that forms the camera body. Therefore, the thickness of the camera is almost determined by the protective glass 21, the prism PR, the fixed frame 13, and the display device 35, and can be made sufficiently thin to increase portability. it can. As described above, it is possible to effectively prevent the optical element from being stained and dust from being attached while ensuring the thinness when not photographing.

It is a perspective view showing typically the composition of the principal part of the lens barrel which constitutes the lens unit concerning one embodiment of the present invention. It is a front view which shows the structure of the principal part of the lens barrel of FIG. It is a disassembled perspective view which shows the structure of the principal part of the lens barrel of FIG. It is a typical fragmentary sectional side view which shows the structure of the optical system used for the lens barrel of FIG. It is a perspective view which shows the state at the time of imaging | photography for demonstrating operation | movement of the retractable lens group in the lens barrel of FIG. It is a perspective view which shows the state in the middle of the accommodation for demonstrating operation | movement of the retractable lens group in the lens barrel of FIG. It is a perspective view which shows the state at the time of accommodation for demonstrating operation | movement of the retractable lens group in the lens barrel of FIG. FIG. 2 is a cross-sectional view of a main part showing a state at the time of photographing for explaining an operational positional relationship between a retracting lens group and a prism as a deflection optical element in the lens barrel of FIG. 1. FIG. 2 is a cross-sectional view of a main part showing a non-photographing and storing state for explaining an operational positional relationship between a retracting lens group and a prism as a deflection optical element in the lens barrel of FIG. 1. It is a perspective view of the photography state which shows the structure of the principal part of the lens unit containing a protective cover. It is a perspective view of the accommodation state which shows the structure of the principal part of the lens unit of FIG. 10 shows in more detail the configuration of the main part of the lens unit in FIG. 10 in a shooting state, where (a) is a front view seen from the front (object side), and (b) is an arrow view along the line AA. It is sectional drawing. 11 shows in more detail the configuration of the main part of the lens unit including the protective cover of FIG. 11 in the housed state, where (a) is a front view seen from the front, and (b) is an arrow view along the line BB. It is sectional drawing. It is a perspective view in the imaging state which looked at the structure of the principal part of the lens unit containing the protective cover of FIG. 10 from the back surface (photographer side). The structure of the principal part of the lens unit containing the protective cover in the middle of accommodation is shown, (a) is the perspective view seen from the back surface, (b) expands and shows the C section in (a). FIG. It is the perspective view in the accommodation state which looked at the structure of the principal part of the lens unit containing the protective cover of FIG. 11 from the back. It is a disassembled perspective view which shows the structure of the principal part of the digital camera as a camera incorporating the lens unit containing the lens barrel of FIGS. It is a perspective view which shows typically the structure of the principal part in the imaging | photography state of the camera of FIG. It is a perspective view which shows typically the structure of the principal part in the accommodation state of the camera of FIG. It is sectional drawing in the imaging | photography state for demonstrating the operation state of the camera of FIG. It is sectional drawing in the accommodation state for demonstrating the operation state of the camera of FIG.

Explanation of symbols

11 Lens holding frame 11a Sleeve portion 11b Sub guide pin 11c Nut engaging portion 11d Spring engaging portion 11e Engaging projection 12 Main shaft (guide shaft)
13 Fixed frame (fixing member)
13a receiving surface 13b rectilinear guide groove 13c retracting cam portion 14 countershaft 15 compression torsion spring 16 lead screw 17 pulse motor 18 nut member 18a anti-rotation projection 18b engagement projection 21 protective glass 22 protective cover 22a first fitting portion 22b first 2 fitting portion 22c engagement receiving portion 23 first protective cover guide shaft 24 second protective cover guide shaft 25 compression spring 31 lens unit 32 circuit board 33 capacitor 34 battery 35 display device 36 memory card 37 strobe 38 front cover 39 Rear cover G1 First lens group (withdrawal lens group)
PR prism (deflection optical element)
G2 Second lens group G3 Third lens group AS Aperture / shutter unit G4 Fourth lens group G5 Fifth lens group G6 Sixth lens group G7 Seventh lens group OF Optical filter IS Image sensor

Claims (5)

An optical system including a plurality of lenses and optical elements, and a protective member for protecting the optical system,
The optical system sequentially from the object side,
A first lens group composed of at least one lens;
A deflection optical element that bends the optical axis of the optical system;
A second lens group composed of at least one lens ;
Is arranged,
The deflecting optical element is fixedly arranged at the same position both during shooting and during non-shooting,
The first lens group is arranged so that the optical axis of the first lens group coincides with the optical axis of the optical system at the time of photographing, and at least one of the first lens group at the time of non-photographing. The retractable lens is used as a retractable lens, and the retractable lens is moved and retracted so as to be out of the optical axis of the optical system,
The protective member is disposed further on the object side of the first lens group, and moves to a space generated by moving the retractable lens from the optical axis of the optical system when not photographing .
The protective member is fixed to a holding member for holding the protective member, and the holding member is a guide member arranged in parallel to the optical axis on the object side of the optical axis bent by the deflecting optical element. A lens unit comprising a fitting portion for fitting, wherein the protective member is movable in parallel with the optical axis on the object side . The holding member is urged in the object side direction of the optical axis by an elastic member, and an engagement receiving portion that engages with the engaging portion provided in the retracting lens during the retracting movement of the retracting lens. When the retractable lens is retracted, the retracting lens engaging portion engages with the engaging receiving portion of the retaining member, so that the holding member is moved along the optical axis on the object side. The lens unit according to claim 1 , wherein the lens unit is moved in a direction opposite to the side. Wherein the protective member is a lens unit according to claim 1 or claim 2, characterized in that it is formed by using a parallel plate which transmits light. A camera comprising an imaging optical system using the lens unit according to any one of claims 1 to 3 . The non-photographing means that the protective member is located on the same side as the object side surface of the camera body or behind it, and at the time of photographing, the protective member is located closer to the object side than during non-photographing. The camera according to claim 4 , characterized in that:

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