JP2003066309A - Lens unit and electronic camera using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a lens unit equipped with a reflecting optical system thin in thickness and small in size, and them to make an electronic camera, to which the lens unit is applied, thin in thickness and small in size. SOLUTION: This lens unit is equipped with a catoptric member 21a reflecting luminous flux made incident from a subject along a first optical axis O1 along a second optical axis O2 crossing with the first optical axis, lens groups (22a, 23a and 24a) provided to freely move along the second optical axis and forming a subject image by transmitting the luminous flux reflected by the catoptric member, an imaging device receiving the subject image formed by the lens groups, and actuators (31 and 32) driving an element to be driven inside the unit. At least two actuators are provided in the unit, and respectively arranged on a side opposite to a side where the lens groups are arranged with respect to the catoptric member and on a side opposite to a side where the lens groups are arranged with respect to the imaging device in a direction along the second optical axis.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens unit and an electronic camera using the same, more specifically, a lens unit having a reflective optical member for bending a light beam incident from a subject, and an electronic image obtained by applying this lens unit. The present invention relates to an electronic camera that acquires data.

[0002]

2. Description of the Related Art Conventionally, a subject image formed based on a light flux from a subject (hereinafter referred to as a subject light flux) incident on a photographing optical system including a plurality of lens groups and the like is obtained at a predetermined position. Means, such as a charge coupled device (C
A desired subject image is obtained by forming an image on the light receiving surface of an image sensor such as a CD (Charge Coupled Device) or a photographic light-sensitive material such as a film for photography, and this is formed in a predetermined recording medium in a predetermined form. A camera configured to record, an electronic camera such as a so-called electronic still camera, a digital video camera, a photographer, a movie camera, or the like has been generally put into practical use and widely spread.

In such a conventional camera, it is usual to include a lens unit including a photographing optical system such as a plurality of lenses for forming a subject image at a predetermined position.

Regarding a lens unit in a conventional camera, for example, a subject light flux that enters the inside of the camera through a plurality of lenses is guided onto a light receiving surface of a predetermined subject image acquisition means such as an image sensor or a photo film. Therefore, by disposing a predetermined reflecting means such as a reflecting mirror in the optical path, the optical path of the subject light flux is configured to be bent in a predetermined direction, for example, in a direction substantially perpendicular to the incident optical axis, etc. Various forms are generally known.

Various proposals have been made for the lens unit to which the so-called bending optical system as described above is applied, for example, in Japanese Patent Laid-Open No. 2001-75162.

In the lens unit disclosed in Japanese Patent Laid-Open No. 2001-75162, the reflecting means for bending the optical axis of the subject light flux in a substantially perpendicular direction is arranged in the optical path of the photographing optical system through which the subject light flux passes. Thus, the camera itself has been downsized while ensuring the optical path length required to acquire an image.

As described above, the use of the so-called bending optical system in which the reflecting means and the like are arranged in the optical path of the photographing optical system of the camera is a very advantageous means for realizing the miniaturization of the camera itself. I can say.

[0008]

By the way, as a main usage of a general camera, it is usual that a user takes it out to the field or the like and uses it. For this reason, the portability of the camera has been emphasized in the past, and there is a demand for further thinning and miniaturization of the camera itself.

In recent years, electronic cameras constructed mainly for the purpose of acquiring electronic still image data have rapidly become widespread, but in such electronic cameras,
A member that constitutes a part of the lens unit, such as a drive mechanism and an actuator for moving the photographic optical system and the like in a predetermined direction for a zooming operation, a focus adjusting operation, and the like, and an electric circuit that controls the actuator It is usually equipped with components.

In this case, various arrangements are required to further miniaturize the camera itself while appropriately arranging various components necessary for constructing the camera inside the camera. ing.

The present invention has been made in view of the above points, and an object of the present invention is to provide a lens unit including a bending optical system, in which each component such as a drive mechanism and an actuator is provided. The objective is to provide a lens unit that has been made thinner and smaller by efficiently arranging it, and to make the electronic camera thinner and smaller by applying it.

[0012]

In order to achieve the above object, a lens unit according to a first aspect of the present invention is a lens unit that crosses a light beam incident from a subject along a first optical axis with a first optical axis. A reflecting optical member that bends along the optical axis of the lens, and a lens group that is movably provided along the second optical axis and that transmits the light beam after being bent by the reflecting optical member to form a subject image. An image pickup device for receiving a subject image formed by the lens group, and an actuator for driving a driven element inside the unit, wherein at least two actuators are provided, and the actuator is provided on the second optical axis. At the respective positions on the side opposite to the side where the lens group is arranged with respect to the reflective optical member and on the side opposite to the side where the lens group is arranged with respect to the image sensor in the direction along Characterized in that it is location.

Therefore, according to the first aspect of the present invention, the two actuators in the direction along the second optical axis are displaced from the position where the lens group is disposed, that is, the position outside the reflective optical member, and the image pickup. Since they are arranged at positions on the outside of the element, respectively, the dimension along the first optical axis, that is, the depth direction of the lens unit can be reduced,
Therefore, it is possible to reduce the size and thickness of the lens unit.

According to a second aspect of the present invention, in the lens unit according to the first aspect, the actuators are arranged so as to be biased in the same direction in a direction orthogonal to the second optical axis. To do.

A third invention is the lens unit according to the first invention or the second invention, wherein the lens group has a first lens group and a second lens group. The actuator is configured to drive the first lens group and the second lens group, respectively, as driven elements.

Therefore, according to the second invention or the third invention, since the two actuators are arranged at positions deviated in the same direction in the direction orthogonal to the second optical axis, the two actuators are driven. It is possible to drive each of the two lens groups that are the two driven elements to be driven with high precision. As a result, it is possible to execute a highly accurate variable magnification operation or focus adjustment operation.

According to a fourth invention, in the lens unit according to the third invention, the first lens group and the second lens group are provided.
Is provided with a guide shaft for guiding the lens group of the first lens group so as to be movable along the second optical axis, and the guide shaft is rotatable in association with one actuator. Alternatively, in order to drive either one of the second lens groups, a drive groove is provided over the moving range of the driven lens group.

Therefore, according to the fourth aspect of the invention, the guide shaft that is rotatable in association with one of the actuators,
Since the drive groove is provided over the moving range of the lens group driven by this, and either the first lens group or the second lens group is driven by this drive groove, the number of parts of the drive system can be reduced. Can be reduced. This can contribute to downsizing of the lens unit.

According to a fifth aspect of the present invention, in the lens unit of the fourth aspect, two guide shafts are provided, and one of the two guide shafts is arranged on a side where the respective actuators are arranged eccentrically. The drive shaft is provided with the drive groove.

Therefore, according to the fifth aspect of the invention, since the drive groove is provided on the guide shaft provided on the side of the two guide shafts on which the two actuators are arranged eccentrically, each actuator is arranged. The two lens groups are driven based on the side guide axis. Therefore, by this, work to match the center position of each lens group,
That is, the work of aligning the optical axis becomes easy. Therefore, it is easy to contribute to the improvement of the optical performance.

A sixth invention is the lens unit according to any one of the third invention, the fourth invention or the fifth invention, wherein the second lens group contributes to the focus adjusting operation. The actuator, which is a lens group and is disposed on a side of the image pickup device opposite to a side on which the lens group is disposed, drives the second lens group.

Therefore, according to the sixth aspect of the invention, the second lens group that contributes to the focus adjusting operation requiring precision is driven by the actuator arranged on the side opposite to the side where the lens group of the image pickup element is arranged. Since this is done, it is possible to perform a more accurate focus adjustment operation. That is,
The shift of the focus adjustment state caused by the zooming operation can be suppressed by highly accurate control.

According to a seventh invention, in the lens unit according to the first invention to the sixth invention, the actuator arranged on the side opposite to the side on which the lens group of the reflection optical member is arranged is the reflection unit. It is characterized in that it is arranged close to the back surface side of the reflection surface of the optical member.

An eighth invention is the lens unit according to the seventh invention, further comprising a frame body for supporting the reflective optical member, and the frame body is provided with fixing means for fixing the actuator. It is characterized by

Therefore, according to the seventh invention or the eighth invention, the actuator arranged at a position outside the reflective optical member (on the side opposite to the side where the lens group is arranged) is reflected by the reflective optical member. Since it is arranged at a position close to the back surface side of the surface, the space on the back surface side of the reflective surface of the reflective optical member can be effectively utilized. This can contribute to downsizing and thinning of the lens unit itself.

An electronic camera according to a ninth aspect of the present invention is the electronic camera according to the first aspect.
~ The lens unit according to any one of the eighth invention is provided inside.

Therefore, according to the ninth aspect of the invention, by applying the lens unit which has been made smaller and thinner by the first to eighth aspects of the invention, the electronic camera itself can be made smaller and thinner. be able to.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below with reference to the illustrated embodiments. FIG. 1 is a perspective view showing the outer appearance of an electronic camera to which the lens unit according to the first embodiment of the present invention is applied. FIG. 2 is a perspective view schematically showing main internal components of the electronic camera.

FIG. 3 is an external perspective view showing only the lens unit according to the first embodiment of the present invention. FIG. 4 is an exploded perspective view showing a part of the lens unit shown in FIG. 3 and showing a drive mechanism for moving the reflective optical member and the variable power lens frame.

First, an electronic camera to which the lens unit of the present invention is applied will be described with reference to FIGS.

As shown in FIGS. 1 and 2, the electronic camera 1 has an exterior member 11 which is a housing having various constituent members inside and formed so that its dimension in the depth direction becomes relatively small.
The outer surface is constituted by. On the upper surface of the exterior member 11, operation members such as a release button 12 which is an operation member for instructing execution of the exposure operation are arranged.

On the front surface of the exterior member 11, a strobe light irradiation window 13 forming a part of the flash light emitting device is arranged at a predetermined position near the upper edge (not shown in FIG. 2). ). An objective optical system in which an objective optical system of a photographing lens unit (see FIG. 2; hereinafter simply referred to as a lens unit) 2 including a photographing optical system is arranged at a predetermined position adjacent to the strobe light irradiation window 13. A taking lens window 14 which is a window is provided.

Inside the electronic camera 1, as shown in FIG. 2, a plurality of circuit boards 15 are arranged at predetermined positions in the substantially central portion so as to be stacked along the depth direction of the electronic camera 1. ing.

The circuit board 15 is provided with operation switches that interlock with various operation members provided on the surface of the exterior member 11 such as the release button 12 and generate predetermined corresponding instruction signals. Therefore, a predetermined instruction signal is generated according to the operation of the operation member such as the release button 12. The circuit board 15 is electrically connected to the image pickup board 28 and the like provided in the lens unit 2.

Inside the electronic camera 1, at a predetermined position near one end, that is, at one end of the space formed at both ends of the circuit board 15, the electronic camera 1 is placed. A battery 16 that serves as a power source is disposed. Although not shown, the battery 16 and the circuit board 15 are electrically connected by a predetermined power supply connection line. As a result, the power of the battery 16 is supplied to the circuit board 15 via the predetermined power supply circuit. Further, the lens unit 2 described above is fixed to the other end of the internal space of the electronic camera 1.

Next, the structure of the lens unit 2 applied to the electronic camera of this embodiment and others will be described in detail below.
As described above, the lens unit 2 is arranged at a predetermined position inside the electronic camera 1. As shown in FIG. 3, the lens unit 2 includes a plurality of frame members respectively holding a plurality of lens groups that contribute to photographing, a drive mechanism for moving the frame members in a predetermined direction, and the lens. The reflection optical member 21a and the like are configured to bend the light flux incident on the unit 2 inside and guide it toward the light-receiving surface of an image sensor (not shown) arranged at a predetermined position.

Specifically, it is as follows. That is, various constituent members constituting the lens unit 2 are arranged at predetermined positions on the lens unit base (hereinafter, simply referred to as a base) 25.

The photographic optical system of the lens unit 2 is a bending optical system and is a reflecting optical member 21a such as a prism made of optical glass or the like, and a magnification is changed by moving in the direction along the optical axis based on a predetermined instruction signal. A zoom lens group 22a, which is the first lens group that contributes to the operation, and a correction system, which is the second lens group, that performs the focus adjustment operation and corrects the deviation of the focus adjustment state caused by the zoom operation. Lens group 23
a and a fixed lens group 24a for finally forming an image of a subject on a predetermined light receiving surface of an image pickup element (not shown).

These lens groups are arranged from the position closest to the subject to the reflective optical member 21a and the zoom lens group 2
2a, the correction system lens group 23a, and the fixed lens group 24a are arranged in this order, and an image pickup substrate 28 on which an image pickup element (not shown) is mounted is arranged at a position behind the fixed lens group 24a.

A connector portion 28a is mounted on an end portion of the image pickup board 28, and an image signal processing circuit or the like is provided on the image pickup board 28 via a flexible printed board 28b connected to the connector portion 28a. It is electrically connected to the circuit board 15 to be mounted.

The reflective optical member 21a has a substantially L-shaped cross section and is fixed and held at a predetermined position on the base 25 by a prism frame 21 which is a frame body fixed near one end of the base 25. ing. The fixed lens group 24 a is fixedly held at a predetermined position on the base 25 by a fixed frame 24 fixed near the other end of the base 25.

Between the prism frame 21 and the fixed frame 24, there are two guide shafts, a drive shaft 26 and a guide shaft 2.
7 are suspended. The drive shaft 26 of the two guide shafts serves as a main guide shaft for guiding the movement of the variable power lens frame 22 and the correction lens frame 23 in the second optical axis O2 direction as described later. It is a thing. Further, the guide shaft 27 serves to prevent the variable power lens frame 22 and the correction lens frame 23 from rotating around the drive shaft 26, and at the same time, the two frames 22 and 23 in the second optical axis O2 direction. It serves as an auxiliary guide shaft for guiding movement.

Both ends of the drive shaft 26 are rotatably supported by the prism frame 21 and the fixed frame 24. In this case, on the side of the fixed frame 24, the drive shaft 26 penetrates through a predetermined portion of the fixed frame 24, and the tip end of the drive shaft 26 projects outside the fixed frame 24. A drive gear 26b is fixed to the protruding tip of the drive shaft 26. In addition, both ends of the guide shaft 27 are also the prism frame 21.
And is fixedly supported by the fixed frame 24.

Here, the optical axis on the incident side (subject side) of the light flux in the reflective optical member 21a is indicated by reference numeral O1 as shown in FIG. 3, and the optical axis indicated by the reference numeral O1 is called the first optical axis. I shall. Further, the optical axis orthogonal to the first optical axis O1 is indicated by the reference numeral O2 as shown in FIG. 3, and the optical axis indicated by the reference numeral O2 is called the second optical axis. This second optical axis O2 is used for the above-mentioned variable power lens group 22.
The center axis of a light flux that passes through substantially the centers of a, the correction system lens group 23a, and the fixed lens group 24a and reaches the image pickup device (not shown) on the image pickup substrate 28 is shown.

The drive shaft 26 and the guide shaft 27 respectively include a variable power lens frame 22 for fixedly holding the variable power system lens group 22a and a correction lens frame 23 for fixedly hold the correction system lens group 23a in FIG. It is supported so as to be independently movable in the direction along the second optical axis O2 shown.

In this case, the support arm 23d formed at one end of the correction lens frame 23 is provided with a through hole along the second optical axis O2 in FIG. The drive shaft 26 is rotatably inserted through the through hole.

The cam pin 23b is attached to the support arm 23d.
Is provided, and the tip portion (not shown) of the cam pin 23b is provided so as to project toward the inside of the through hole of the support arm 23d. Correspondingly, a cam groove 26a, which is a drive groove, is formed over a predetermined range on a part of the peripheral surface of the drive shaft 26 near the position where the correction lens frame 23 is arranged. That is, this cam groove 26a
Are formed over the moving range of the correction lens frame 23 that holds the correction system lens group 23a that is driven by the rotation of the drive shaft 26. Then, the cam groove 2
The cam pin 23b described above is cam-engaged with 6a.

On the other hand, at the other end of the correction lens frame 23, a bearing portion 23e having a substantially U-shaped cross section is formed.
The guide shaft 27 is arranged inside the bearing portion 23e. In this case, the guide shaft 27 prevents the correction lens frame 23 from rotating about the drive shaft 26 and guides the movement of the correction lens frame 23 in the direction along the second optical axis O2 in FIG. Has a role to do.

Therefore, the drive shaft 26 is used as the correction lens frame 2
3 is rotated by a correction lens drive mechanism (details will be described later) that drives the lens 3 so as to move in the direction along the second optical axis O2, the correction lens frame 23 causes the second optical axis to move along with this rotation operation. It is designed to move in the direction along O2.

On the other hand, in the base portion 22dd of the support arm 22d formed at one end portion of the variable power lens frame 22, a through hole similar to the through hole of the correction lens frame 23 described above is formed in the direction along the second optical axis O2. Has been drilled. Drive shaft 2 for this through hole
6 is rotatably inserted.

Then, the variable magnification lens frame 22 and the prism frame 2
In the space between the drive shaft 26 and the drive shaft 26, an urging member 30 such as an extensible coil spring is wound around the drive shaft 26. This urging member 30 has one end portion which is the base portion 22 of the support arm 22d.
It is in contact with the surface of dd facing the prism frame 21, and the other end is in contact with the surface of the supporting frame 22d of the prism frame 21 facing the base 22dd. As a result, in a normal state, the biasing force of the biasing member 30 acts in the direction in which the variable magnification lens frame 22 is separated from the prism frame 21.

A wire hooking portion 22c is provided near the tip 22b of the support arm 22d of the variable power lens frame 22. The wire hooking portion 22c has a linear member 34 forming a part of a variable power lens driving mechanism (details will be described later) that drives the variable power lens frame 22 to move in the direction along the second optical axis O2. Are connected at one end.

On the other hand, at the other end of the variable power lens frame 22, a bearing portion 22e having a substantially U-shaped cross section is formed.
A guide shaft 27 is arranged inside the bearing portion 22e. In this case, the guide shaft 27 prevents the variable power lens frame 22 from rotating about the drive shaft 26 and guides the movement of the variable power lens frame 22 in the direction along the second optical axis O2. It plays a role in the correction lens frame 2 described above.
The bearing portion 23e of No. 3 is completely the same.

Therefore, the variable power lens frame 22 is arranged so as to be movable in the direction along the second optical axis O2, and the variable power lens drive mechanism acts on the variable power lens frame 22. When this happens, the variable magnification lens frame 23
Moves toward the prism frame 21, or by the action of the biasing member 30, the variable power lens frame 22 can move along the second optical axis O2 in the direction away from the prism frame 21. It is like this.

The prism frame 21 has a reflective optical member 21a.
Is fixed. The reflective optical member 21a bends a light beam (subject light beam) incident from a subject existing at a position facing the front surface of the electronic camera 1 at a substantially right angle and guides it toward an image sensor (not shown). It is an optical member.

The prism frame 21 has a substantially L-shaped cross section as described above, and the reflective optical member 21a is
It is arranged on the side of the long arm portion 21b (see FIG. 4).
A variable power lens drive mechanism for moving the variable power lens frame 22 as a driven element in the direction along the optical axis O2 is provided on the short arm portion 21c side of the prism frame 21.

As shown in FIG. 4, this variable power lens drive mechanism comprises a variable power actuator 31 which serves as a drive source for variable power operation.
A pulley 33 fixed near the tip of the rotary shaft 31a of the variable power actuator 31 and having a groove 33a formed on the outer peripheral surface thereof; and a linear wire having one end fixed to the groove 33a of the pulley 33. It is configured by the member 34 and the like.

The variable-magnification actuator 31 includes a rotary shaft 3
A flange portion 31b is provided near the base end portion of 1a. The flange portion 31b is provided with a screw 40 as a fixing means.
Is used to attach to the short arm portion 21c of the prism frame 21. As a result, the variable power actuator 31 is fixedly supported by the prism frame 21. And
At this time, the rotation shaft 31a is connected to the short arm portion 21 of the prism frame 21.
It is arranged so as to project outward from the hole 21d formed in c.

In this case, the reflection optical member 21a attached to the prism frame 21 has an optical axis O1 shown in FIG.
And a reflecting surface having an inclination angle of about 45 degrees with respect to each of the optical axis O2. This reflecting surface is provided for the object located on the extension line of the optical axis O1 and the optical axis O2.
Each lens (22a ・ 23a ・ 24) located on the extension line of
a) and an image pickup device (not shown) on the image pickup substrate 28, respectively. The reflective optical member 21a is formed so that a predetermined space is formed on the back surface side of the reflective surface, that is, a portion facing the base 25. Then, in this space, the variable magnification actuator 31
Are arranged.

Rotating shaft 31a of actuator 31 for magnification change
As described above, the pulley 33 is fixedly provided near the tip of the. One end of the linear member 34 is fixedly provided in the groove portion 33a of the pulley 33. The other end of the linear member 34 is connected to the wire hooking portion 22c provided on the tip end portion 22b of the support arm 22d of the variable power lens frame 22 as described above (see FIG. 3).

Therefore, when the variable-magnification actuator 31 is driven and the rotation shaft 31a starts to rotate in a predetermined direction (one of the directions of arrows R1 and R2 shown in FIG. 3),
At the same time, the pulley 33 rotates in the same direction. Along with this, the variable power lens frame 22 connected to the linear member 34 has the optical axis O
It is adapted to move in the direction along 2 (either one of the arrow X1 and X2 directions shown in FIG. 3).

On the other hand, in the vicinity of the drive gear 26b of the drive shaft 26, the correction system lens drive for moving the correction lens frame 23 holding the correction system lens group 23a as the driven element in the direction along the optical axis O2. A correction system actuator 32 for driving the mechanism is provided. The correction system actuator 32 is fixedly installed on the base 25.

A drive gear 32a is fixed to the tip of the rotation shaft of the correction system actuator 32. The drive gear 32 a meshes with the drive gear 26 b of the drive shaft 26. Therefore, the correction system actuator 32
Is transmitted to the drive shaft 26 so that it can be rotated in a predetermined direction. When the drive shaft 26 rotates, the action of the cam groove 26a of the drive shaft 26 and the cam pin 23b of the correction lens frame 23 causes the correction lens frame 23 to move in the direction along the optical axis O2 (arrow X1 shown in FIG. 3).・ It is designed to move in either direction X2).

The lens unit of this embodiment having the above-described structure operates as follows. That is, first, when the electronic camera 1 is in the shooting preparation state, the user performs a predetermined operation for executing the magnification changing operation, and receives the magnification changing instruction signal generated by the operation, and the circuit board 15 receives the magnification changing instruction signal. The control circuit (not shown) mounted in
The drive control of the scaling actuator 31 is performed. Then, the rotary shaft 31a of the variable power actuator 31 is
It rotates in one of the directions of arrows R1 and R2 shown in FIG. At the same time, the pulley 33 also rotates in the same direction.

Here, the pulley 33 is the arrow R shown in FIG.
When rotated in one direction, the linear member 34 causes the pulley 3 to move.
It is rolled up by 3. Therefore, along with this, the variable power lens frame 22 moves in the direction of arrow X1 shown in FIG. 3 against the biasing force of the biasing member 30.

On the other hand, the pulley 33 has an arrow R2 shown in FIG.
When rotated in the direction, the linear member 34
Rewound by. Therefore, along with this, the variable power lens frame 22 moves in the arrow X2 direction shown in FIG. 3 by the biasing force of the biasing member 30.

When the magnification varying operation is executed by moving the magnification varying lens frame 22 in the arrow X1 direction or the arrow X2 direction in FIG. 3 as described above, the focus state changes. In order to correct this, a control circuit (not particularly shown) mounted on the circuit board 15 drives and controls the correction system actuator 32 in conjunction with the zooming operation.

When the correction system actuator 32 is driven and the drive gear 32a rotates in a predetermined direction, the drive shaft 26 rotates in a predetermined direction via the drive gear 26b meshing with the drive gear 32a. As a result, the correction lens frame 23
Moves the arrow X1 direction or the arrow X2 direction in FIG. 3 and arranges the correction lens frame 23 so as to be at a predetermined position according to the zooming operation.

As described above, according to the first embodiment, the two actuators, the variable magnification actuator 31 and the correction system actuator 32, are arranged in the respective lens groups (22a) in the direction along the second optical axis O2.・ 23a ・ 24
a position deviated from the arrangement position of a), that is, the reflective optical member 21.
Since they are arranged at a position outside of a and a position outside of the image pickup device (not shown) on the image pickup substrate 28, respectively, the direction along the first optical axis O1, that is, the depth of the lens unit 2 is determined. The dimension in the direction can be reduced. Therefore, the lens unit 2 can be made smaller and thinner.

Further, according to the present embodiment, the second optical axis O
In the direction orthogonal to 2, the two actuators 31.
Since 32 is arranged, the two actuators 31 and 32
Each of the two lens groups (the variable power lens group 22a held by the variable power lens frame 22 and the correction system lens group 23a held by the correction lens frame 23), which are the two driven elements driven by Can be moved to. As a result, it is possible to execute a highly accurate variable magnification operation or focus adjustment operation.

In the present embodiment, the guide shaft (driving shaft 26) that is rotatable in association with one actuator (correction system actuator 32) is driven by the lens group (correction system lens group). 23a) is provided with a drive groove (cam groove 26a), and the drive groove (26a) drives the second lens group (23a) (guide for guiding the movement of the variable magnification lens frame 22). Since a part of the shaft is used as a drive system for driving the correction lens frame 23), the number of parts of the drive system can be reduced. This can contribute to downsizing of the lens unit, reduce the number of manufacturing steps, and contribute to reduction of manufacturing cost.

Further, since the cam groove 26a is provided on the side where the two actuators (31, 32) of the two guide shafts (26, 27) are eccentrically arranged, that is, on the side of the drive shaft 26, the drive is performed. The two lens groups are driven with the axis 26 as a reference. This can facilitate the work of aligning the center positions of the lens groups, that is, the work of aligning the optical axes. Therefore, this makes it possible to avoid a problem such as an optical axis shift, which facilitates the improvement of the optical performance of the lens unit 2.

The second lens group (correction system lens) that contributes to the focus adjusting operation requiring extremely high accuracy by the correction system actuator 32 arranged outside the image pickup device (on the side opposite to the side where the lens group is arranged). Since the correction lens frame 23 holding the group 23a) is driven, it is possible to perform a more accurate focus adjustment operation. That is, the shift of the focus adjustment state caused by the zooming operation can be suppressed by highly accurate control.

The variable-magnification actuator 31 arranged outside the reflective optical member 21a (on the side opposite to the side where the lens group is arranged) is arranged at a position close to the back surface side of the reflective surface of the reflective optical member 21a. Therefore, the space on the back surface side of the reflecting surface of the reflecting optical member 21a can be effectively used. This can contribute to downsizing and thinning of the lens unit 2 itself.

Therefore, the electronic camera 1 to which the lens unit 2 which has been made smaller and thinner is applied can also be easily made smaller and thinner.

Next, regarding the second embodiment of the present invention,
This will be described below. FIG. 5 is an external perspective view showing only the lens unit according to the second embodiment of the present invention. In addition, FIG.
FIG. 6 is an exploded perspective view of an essential part showing a part of the lens unit shown in FIG. 5, which is an enlarged view of only a part of a driving mechanism for moving the variable power lens frame.

As shown in FIG. 5, the lens unit 2A of the present embodiment is basically of the same configuration as the lens unit 2 of the above-described first embodiment, and has a variable power lens frame. The only difference is the configuration of the drive mechanism for moving 22A along the second optical axis O2. Therefore, the same components as those in the first embodiment described above are designated by the same reference numerals, detailed description thereof will be omitted, and only different portions will be described in detail below.

In the lens unit 2A of this embodiment, the short arm portion 21c of the prism frame 21 is provided with a variable power lens drive mechanism for moving the variable power lens frame 22A in the direction along the optical axis O2. .

The variable-magnification lens drive mechanism in the present lens unit 2A has a variable-magnification actuator 31 serving as a driving source for variable-magnification operation, and a tip end portion of a rotary shaft 31a of the variable-magnification actuator 31, as shown in FIG. It is constituted by a pulley 41 fixedly provided in the vicinity and having an outer peripheral surface formed with a gear portion 41a, a timing belt 43 meshing with the gear portion 41a of the pulley 41, and the like.

The variable-magnification actuator 31 has the above-mentioned first structure.
It is attached and fixedly supported on the short arm portion 21c of the prism frame 21 by using the same means as in the above embodiment. Therefore, also in the present embodiment, the magnification changing actuator 31 is arranged in the space formed on the back surface side of the reflection surface of the reflection optical member 21 a attached to the prism frame 21, that is, in the space facing the base 25. .

A pulley 42 having substantially the same shape as the pulley 41 is rotatably fixed to one side surface of the fixed frame 24. The other end of the timing belt 43 meshes with the gear portion 42a of the pulley 42.

Then, a predetermined portion of the timing belt 43 is fixed to the tip portion 22 of the support arm 22d of the variable magnification lens frame 22A by using the belt pressing member 46 as shown in FIGS.
It is fixed at b.

That is, as shown in FIG. 6, in the belt fixing portion 44 of the timing belt 43, the timing belt 43 is fixed to the variable magnification lens frame 22A by the following means.

The belt pressing member 46 is a plate-shaped small piece member having a screw hole 46a formed substantially in the center thereof. In accordance with this, a screw hole 22f is provided on the upper surface of the tip portion 22b of the support arm 22d. Also, the timing belt 4
A through hole 43a is bored at a predetermined portion of No. 3.

Then, at the tip 22b of the support arm 22d,
The timing belt 43 and the belt pressing member 46 are placed on top of each other. At this time, the screw hole 22f, the through hole 43a, and the screw hole 46a are brought into a matched state. In this state, the shaft portion of the screw 45 is passed through the screw hole 46a and the through hole 43a, and the screw 45 is screwed into the screw hole 22f. In this way, the timing belt 43 is
The zoom lens frame 22 is fixed at a predetermined position.

Therefore, when the variable-magnification actuator 31 is driven and the rotating shaft 31a starts rotating in a predetermined direction (one of the directions of arrows R1 and R2 shown in FIG. 5),
At the same time, the pulley 41 rotates in the same direction. Along with this, the variable magnification lens frame 22A connected to the timing belt 43.
Moves in the direction along the optical axis O2 (one of the directions of arrows X1 and X2 shown in FIG. 5).

The other structure is exactly the same as that of the first embodiment. The operation of the lens unit 2A of the present embodiment configured as described above is also substantially the same as that of the above-described first embodiment.

As described above, according to the second embodiment, the zoom lens driving mechanism having a different structure from that of the first embodiment is used, and exactly the same as the first embodiment. The effect of can be obtained.

Further, in this embodiment, since the variable power lens drive mechanism is constructed by using the timing belt 43, the variable power lens frame 22A can be reliably moved.

In each of the above-described embodiments, an example in which the lens unit 2.2A of the present invention is applied to an electronic camera has been described, but the present invention is not limited to this, and for example, a photograph such as a photo film is taken. It can be easily applied to a general camera or the like using a photosensitive material.

[0091]

As described above, according to the present invention, in a lens unit including a bending optical system, each constituent member such as a drive mechanism and an actuator is efficiently arranged to reduce the thickness and By providing a lens unit that is downsized and applying the lens unit, it is possible to reduce the thickness and size of the electronic camera.

[Brief description of drawings]

FIG. 1 is a perspective view showing an external appearance of an electronic camera to which a lens unit according to a first embodiment of the present invention is applied.

FIG. 2 is a perspective view schematically showing main internal components of the electronic camera shown in FIG.

FIG. 3 is an external perspective view showing only a lens unit applied to the electronic camera of FIG.

FIG. 4 is an exploded perspective view of a part of the lens unit shown in FIG. 3, showing a drive mechanism for moving a reflective optical member and a variable power lens frame.

FIG. 5 is an external perspective view showing only a lens unit according to a second embodiment of the present invention.

6 is an exploded perspective view of a part of the lens unit shown in FIG. 5, showing a part of a drive mechanism for moving the variable power lens frame in an enlarged manner. FIG.

[Explanation of symbols]

1 ... Electronic camera 2.2A ... Lens unit 21 ... Prism frame 21a ... Reflective optical member 22.22A ... Zoom lens frame 22a ... Zoom lens group (first lens group, driven element) ) 23 ... Correction lens frame 23a ... Correction system lens group (second lens group, driven element) 23b ... Cam pin 24 ... Fixed frame 24a ... Fixed lens group 25 ... Base (lens unit) 26 ...... Drive shaft (main guide shaft) 26a …… Cam groove (drive groove) 27 …… Guide shaft (sub guide shaft) 28 …… Imaging board 30 …… Biasing member 31 …… Scaling actuator 32 …… Correction System actuators 33, 41, 42 ... pulley 34 ... linear member 43 ... timing belt 46 ... belt pressing member

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2H044 AJ04 BE02 BE06 BF01 DA01                       DA02 DB02 DD03 DD07 EF02                       EF03 EF08                 5C022 AA13 AB15 AB40 AB66 AC22                       AC32 AC42 AC54 AC70 AC73                       AC74 AC78

Claims (9)

[Claims] 1. A reflective optical member that bends a light flux incident from a subject along a first optical axis along a second optical axis that intersects the first optical axis, and moves along the second optical axis. A lens group that is freely provided and that transmits a light beam after being bent by the reflective optical member to form a subject image, an image pickup element that receives the subject image formed by the lens group, and An actuator that drives a driven element, and at least two actuators are provided, and a side where the lens group is arranged with respect to the reflective optical member in a direction along the second optical axis. Is disposed on the opposite side and on the side opposite to the side on which the lens group is disposed with respect to the image sensor, respectively. 2. The lens unit according to claim 1, wherein the actuators are arranged so as to deviate in the same direction in a direction orthogonal to the second optical axis. 3. The lens group includes a first lens group and a second lens group, and the actuator includes the first lens group and the second lens group as driven elements, respectively. The lens unit according to claim 1 or 2, wherein the lens unit is configured to be driven. 4. A guide shaft for guiding the first lens group and the second lens group so as to be movable along a second optical axis, wherein the guide shaft is interlocked with one actuator. And a drive groove is provided over the moving range of the driven lens group in order to drive either the first lens group or the second lens group. The lens unit according to claim 3, wherein the lens unit is a lens unit. 5. The two guide shafts are provided, and the drive groove is provided on the guide shaft provided on the side of the two guide shafts on which the actuators are arranged eccentrically. The lens unit according to claim 4, wherein 6. The second lens group is a lens group that contributes to a focus adjustment operation, and the actuator arranged on the side opposite to the side where the lens group of the image pickup element is arranged is the first lens group. The lens unit according to claim 3, which drives the second lens group. 7. An actuator arranged on a side of the reflective optical member opposite to a side on which the lens group is arranged,
7. The reflective optical member is arranged in close proximity to the back surface side of the reflective surface of the reflective optical member.
The lens unit according to any one of 1. 8. A frame for supporting the reflective optical member,
The lens unit according to claim 7, further comprising: a fixing means for fixing the actuator to the frame body. 9. Claims 1, 2, 3, 4, 5, 6, 7 ,.
8. An electronic camera comprising the lens unit described in any one of 8 inside.