JPH09211301A - Mechanism for adjusting initial focal point for camera provided with variable focus lens - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily perform the adjusting operation of an initial focal point by guiding the linear driving of a first driving lens barrel with respect to a fixed lens barrel by means of a guiding means in an optical axis direction, attaching/detaching a focusing position adjusting member to/from the guiding means and changing the initial position of the first driving lens barrel with respect to the fixed lens barrel, so that the adjustment of an initial focal point can be performed in a camera provided with a variable focus lens with a three-step extending type lens barrel. SOLUTION: A supporting part 22b is formed on one part of a first driving lens barrel 22, a nut member 24 in which a female screw part 24a is formed is freely inserted in a nut holder 22d formed on one part of the part 22b, and a driving screw 25 whose direction is in parallel with the direction of an optical axis S is screwed to the part 24a. A washer 26 with a U-shaped notched part 26a formed is attachable- detachable to/from the screw 25, the initial position of the lens barrel 22 is changed when the washer 26 is attached/detached in a state where the lend barrel 22 is assembled in the fixed lens barrel, so that the thickness, etc., of the washer 26 is adjusted and the initial focal point can be adjusted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an initial focus adjusting mechanism for adjusting the focus of a camera equipped with a variable focus device in which a taking lens is driven to change its magnification.

[0002]

2. Description of the Related Art With the spread of cameras in recent years, it has been desired to reduce the size, thickness, and weight of this type of popular camera, and at the same time, change the magnification of a zoom device or a focal length switching device. It is required to mount a mechanism. The variable power mechanism is a mechanism for moving the photographing lens in the optical axis direction. For example, on the telephoto side, the photographing lens protrudes from the camera body and is positioned at the front position, and on the wide angle side or the standard side, it is positioned at the camera body side. That is, the lens barrel holding the photographing lens is moved in the optical axis direction with respect to the camera body.

In order to move the taking lens within a predetermined range in order to obtain a sufficient magnification while reducing the thickness of the camera, the lens barrel is constituted by four stages, and three of the lens barrels are used. It is necessary to adopt a structure of sequentially moving. That is, the first driving lens barrel can be moved forward and backward with respect to the fixed lens barrel,
It is necessary to configure the second drive lens barrel so that the second drive lens barrel can move forward and backward with respect to the first drive lens barrel, and the moving lens barrel that holds the photographing lens with respect to the second drive lens barrel can move forward and backward. In addition, the amount of movement of the lens barrel must be such that the photographing optical system is maintained in a predetermined optical relationship. A structure using a cam cylinder is known as a structure for moving the lens barrel forward and backward, and this structure can also be used for this drive mechanism. However, in order to reduce the thickness of the camera body and secure a sufficient amount of movement of the lens barrel, the length of the cam increases, and a cam hole is formed over the entire area of the lens barrel. Therefore, the strength of the lens barrel may be insufficient. In particular, since a single driving source is used, which is advantageous in terms of cost, the length of the cam is further increased in a photographing lens in which a mechanism for performing a zooming operation and a focusing operation by the same cam is employed. As the length increases, the strength of the lens barrel further decreases. For this reason, the cam formed on the lens barrel is formed into a cam having a bottomed groove shape without using a through hole.

Further, one driving lens barrel is moved forward and backward in the optical axis direction without rotating, and the other lens barrel is rotated around the optical axis to move forward and backward in the optical axis direction. Japanese Patent Application Laid-Open No. 7-128567 proposes a structure in which the front lens group support barrel is moved back and forth in the optical axis direction by the rotation of the barrel.

[0005]

However, when the above-mentioned drive mechanism having a cam groove with a bottomed cam or the structure described in Japanese Patent Application Laid-Open No. 7-128567 is used, the following is obtained. There will be problems. That is, in the camera with the variable focus lens device, it is necessary to adjust the initial focus for adjusting the focal length in a state where the taking lens is assembled in the camera. This adjustment is performed by moving the lens barrel holding the taking lens back and forth in the optical axis direction to determine the initial position of movement in the optical axis direction. Therefore, the position of the first driving lens barrel with respect to the fixed lens barrel is adjusted by inserting, for example, a spacer.

By the way, in the conventional mechanism in which a cam hole is formed in the lens barrel and driven, two mirrors for guiding the movement of the pin portion connected to the cam hole in the optical axis direction and for regulating the movement amount thereof are provided. It has a mechanism that connects to the cam hole of the body. However, if the cam is formed in the shape of a groove with a bottom, it is impossible to penetrate the lens barrel with the pin portion. Therefore, a member for regulating the moving direction and the moving amount of the pin portion is required, and the lens barrel having the cam is formed. In addition, a driving ring member and the like are required. Further, in the three-stage extension zoom lens barrel described in JP-A-7-128567, the fixed barrel integrated with the camera body is formed by a double structure of an inner barrel and an outer barrel. The rotary cylinder is housed between the outer cylinder and the outer cylinder.

In such a structure in which the driving ring member is provided and the fixed lens barrel has a double structure, when the initial focus is adjusted, the spacer is inserted or the first driving lens barrel is used. When adding the positioning member of
It is necessary to remove the first driving lens barrel from the fixed lens barrel and insert a spacer or the like. Therefore, the work for adjusting the initial focus is complicated.

Therefore, according to the present invention, the taking lens can be driven with a simple structure,
An object of the present invention is to provide an initial focus adjustment mechanism for a camera with a variable focus lens device, which enables adjustment of the initial focus without removing parts or the like from the fixed lens barrel.

[0009]

As a technical means for achieving the above object, an initial focus adjusting mechanism of a camera with a variable focus lens device according to the present invention is constructed by advancing and retracting a taking lens in an optical axis direction. In a camera with a variable focus lens device having a photographing optical system for performing a zooming operation or a focusing operation, the camera is housed in a fixed lens barrel, and the linear driving means does not rotate about the optical axis with respect to the fixed lens barrel. Is provided with a driving lens barrel which is guided by a guide means to move forward and backward in the optical axis direction, a focus position adjusting member is detachably provided on the guide means, and the driving lens barrel is assembled in a fixed lens barrel, By attaching and detaching the position adjusting member, the initial position of the drive lens barrel with respect to the guide means is changed to adjust the initial focus.

When the focus position adjusting member is attached to the guide means, since the position of the guide means is fixed together with the fixed lens barrel, the moving range of the driving lens barrel is restricted by the focus position adjusting member, The distance between the fixed barrel and the drive barrel in the initial position is changed. That is, the position where the drive lens barrel comes into contact with the focus position adjusting member is the end of the movement. When the photographing lens is connected to the driving lens barrel via another driving lens barrel or a moving lens barrel, the positions of these photographing lenses are changed with respect to the fixed lens barrel. Therefore, the focus position of the photographing lens can be adjusted. Since this guide means guides the linear movement of the drive lens barrel, it can be disposed outside the drive lens barrel. Therefore, the focus position adjusting member is incorporated in the fixed lens barrel. It can be attached and detached in the state.

The guide means is formed by a drive screw having a male screw so that the member for linearly driving the drive lens barrel can be used also as the guide means to reduce the number of parts. A female screw portion screwed with the drive screw is provided so as to be connected to a part of the drive lens barrel, and the position of the drive lens barrel with respect to the female screw portion is changed by attaching and detaching the focus position adjusting member. It is characterized by making adjustments.

When the drive screw is rotated, the drive means connected to the female screw portion screwed with the drive screw moves back and forth along the drive screw. This drive screw serves as guide means, and by attaching and detaching the focus position adjusting member to the drive screw, the positional relationship between the female screw portion and the drive lens barrel is changed, and the position of the drive lens barrel with respect to the guide means is changed. The focus position can be adjusted.

Further, in order to easily attach / detach the focus position adjusting member, the focus position adjusting member is constituted by a washer having a U-shaped notch, and its longitudinal direction with respect to the guide means. It is characterized in that the washer is attached / detached in the intersecting direction to change the position of the drive lens barrel with respect to the female screw portion to adjust the initial focus.

The washer can be attached / detached by inserting / removing the notched portion of the washer into / from the guide means, and the position of the drive lens barrel with respect to the fixed lens barrel can be changed by changing the thickness and the number of the washer to be mounted. The focus position can be adjusted.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The initial focus adjusting mechanism of a camera with a variable focus lens device according to the present invention will be specifically described below based on the preferred embodiments shown in the drawings.

FIG. 2 is a sectional view of the rear surface of a camera provided with a driving device for a photographing lens of a camera with a variable focus lens device according to the present invention, and FIG. 3 is a sectional view of a plane. A cartridge chamber 2 and a spool chamber 3 are arranged with the taking lens 1 in between. A dry battery 4 for power supply and a main condenser 5 for a strobe circuit are arranged on the opposite side of the taking lens 1 with the spool chamber 3 in between, and a drive motor which is a drive source for a lens barrel and the like is provided under the dry battery 4. 6 are provided. A pinion 7 fitted to the output shaft of the drive motor 6 is connected via a gear train 8 to a lens barrel drive gear 9 as power split means. The lens barrel drive gear 9 is formed by extending the tooth width in the optical axis direction as shown in FIG. 3, and the lens barrel drive gear 9 includes a first drive gear 11 as a first lens barrel drive means. The drive transmission gear 12 meshes. Further, as shown in FIGS. 2 and 4, the drive transmission gear 12 is rotatably supported by a rear end portion of a first drive lens barrel, which will be described later, about a direction parallel to the optical axis S. The second drive gear 13 as the two lens barrel drive means is meshed. As shown in FIG. 2, a transmission gear 14 meshes in the middle of the gear train 8, and an appropriate gear train (not shown) is connected to the transmission gear 14 to obtain the driving force of the variable power mechanism of the finder. There is.

As shown in FIGS. 4 and 5, the camera body 20
A fixed lens barrel 21 is attached to the fixed lens barrel 21.
A first driving lens barrel 22 as a driving lens barrel whose position is adjusted at the time of adjusting the initial focus is housed slidably in the direction of the optical axis S inside. As shown in FIG. 1, the first driving lens barrel 22 has a support portion 22b formed on a part of the lens barrel body 22a, and a guide hole 22c formed at one end of the support portion 22b has a guide hole 22c. As shown in FIG. 3, the guide rod 23 supported along the direction of the optical axis S is loosely inserted. A nut holder 22d is formed by opening the lower side at the other end of the support portion 22b, and a through hole 22e is formed in each of the surfaces of the nut holder 22d orthogonal to the optical axis S. This nut holder
A nut member 24 is removably inserted into 22d, and a female screw portion 24 formed on the nut member 24 in the mounted state.
The a is aligned with the through hole 22e.

A drive screw 25 as guide means is screwed into the nut member 24 loaded in the nut holder 22d. The drive screw 25 is arranged along the direction of the optical axis S as shown in FIG. 3, and the first drive gear 11 is fitted to one end thereof to rotate the first drive screw 11. It is designed to rotate with. In addition, as shown in FIG.
When the drive screw 25 is screwed into the, the washer 26 is incorporated. Moreover, the washer 26 has a substantially U-shaped notch 26a, and the washer 26 can be attached and detached by inserting and removing it in the direction orthogonal to the drive screw 25 even when the drive screw 25 is screwed into the nut member 24. I am doing it.

A helicoid 22f is formed on the inner peripheral surface of the first driving lens barrel 22, and a second driving lens barrel 27 having a helicoid 27a which is screwed with the helicoid 22f is formed on the outer peripheral surface. It is housed in the first drive lens barrel 22. This second
As shown in FIG. 4, an internal gear 27b is formed at the rear end of the inner peripheral surface of the drive lens barrel 27, and the internal gear 27b is driven by the internal gear 27b.
28 meshed. The driven gear 28 is connected to a connecting shaft 29 arranged in parallel with the optical axis S, and is rotated together with the connecting shaft 29 by, for example, a spline or the like, and is connected to the connecting shaft 29.
It is slidable with respect to. The second drive gear 13 is fitted to the rear end of the connecting shaft 29, and the connecting shaft 29 is also rotated by the rotation of the second drive gear 13. A rear end of the connecting shaft 29 is rotatably supported by a rear portion of the first drive lens barrel 22, and a rear end portion of the second drive lens barrel 27 is rotatably and slidable from a central portion to a front end portion. It is movably supported.

A helicoid 27c is formed on the inner peripheral surface of the second drive lens barrel 27, and the moving lens barrel 30 is formed with a helicoid 30a that meshes with the helicoid 27c.
It is housed in the drive lens barrel 27. The movable lens barrel 30 holds a front lens group 31, and the front lens group 31 is a movable lens barrel.
It is designed to move in sync with 30.

A first key 36 as a first linearly moving member is fixed to the rear end portion of the first driving lens barrel 22 so that the first key 36 moves together with the first driving lens barrel 22 in the direction of the optical axis S. I am going to move back and forth. A second key 37 as a second linearly moving member is connected to the rear end portion of the second driving lens barrel 27. The second drive lens barrel
A flange portion 27d directed inward is formed at the rear end portion of 27, and by connecting the rear end portion of the second key 37 with the flange portion 27d sandwiched at an appropriate interval,
The second key 37 moves forward and backward together with the second driving lens barrel 27 in the direction of the optical axis S, and the second driving lens barrel 27 rotates with respect to the second key 37.

As shown in FIG. 6, the first key 36 extends forwardly to a flange portion 36a having an opening in the central portion, which is locked to the rear end portion of the first driving lens barrel 22 and extends. Key part of the book
It is formed in a shape provided with 36b. The second key 37 has a cylindrical body 37a, and a flange 37b formed at the rear end of the body 37a for engaging with the flange 27d of the second drive lens barrel. Part 37a
A key opening 37c is formed through which the key portion 36b of the first key 36 is loosely inserted. Therefore, the second key 37 is slidable in the optical axis S direction with respect to the first key 36 with the key portion 36b of the first key 36 loosely inserted into the key opening 37c from the flange portion 37b side. It is said that.

The movable lens barrel 30 is loosely fitted in the main body portion 37a of the second key 37. As shown in FIG. 6, a proper number of guide holes 37d whose longitudinal direction is parallel to the optical axis S are formed in the main body portion 37a, and the guide hole 37d is formed on the inner surface of the rear end portion of the movable lens barrel 30. Guide protrusion 30b loosely inserted in the guide hole 37d
Are formed. Therefore, the key portion 36 of the first key 36
b is loosely inserted in the key opening 37c of the second key 37, and the second key 37
With the guide protrusion 30b of the movable lens barrel 30 loosely inserted in the guide hole 37d of the movable lens barrel 30, the first key 36 and the second key 37
And are integrated with each other and can move back and forth in the direction of the optical axis S, and the movable lens barrel 30 is prevented from rotating around the optical axis S.

Further, the rear group lens 32 is held by the rear group lens frame 33, and the outer peripheral surface of the rear group lens frame 33 is shown in FIG.
A connecting pin 33a is provided so as to project as shown in FIG. On the other hand, as shown in FIG. 6, the second key 37 has a guide slit 37e formed along the direction of the optical axis S. The connecting pin 33a is loosely inserted in the guide slit 37e, and the tip thereof is further inserted. The portion is loosely inserted in a cam groove (not shown) formed on the inner surface of the second drive lens barrel 27. Therefore, when the second drive lens barrel 27 is rotated and moved forward, the movement amount is regulated by the connecting pin 33a being guided by the cam groove, and is moved in the optical axis S direction by being guided by the guide slit 37e. Therefore, the rear lens group 32 moves in the direction of the optical axis S with a predetermined amount of movement. Moreover, the amount of movement is different from the amount of movement of the movable lens barrel 30, and therefore the front lens group 31
And the rear lens group 32 maintain a predetermined optical relationship and the optical axis S
Will move in the direction of. In addition, as shown in FIG. 6, the guide slit 37 is provided at the rear end of the movable lens barrel 30.
A notch 30c for receiving the tip of the connecting pin 33a is formed at a position overlapping with e.

The operation of the embodiment of the driving device for the photographing lens of the camera with variable focus lens device according to the present invention constructed as above will be described below.

FIG. 4 shows a state in which the front lens group 31 and the rear lens group 32 have moved to the frontmost portion, and FIG. 5 shows a state in which they have moved to the rearmost portion. In FIG. 5, when the drive motor 6 is actuated to rotate the lens barrel drive gear 9, the first drive gear 11 meshing with the lens barrel drive gear 9 is rotated, and the first drive gear 11 is rotated. Since the drive screw 25 is fitted in the drive screw 25, the drive screw 25 also rotates in the same direction. A nut member 24 is screwed into the drive screw 25.
24 is accommodated in the nut holder 22d of the first drive lens barrel 22, and since the first drive lens barrel 22 is guided by the guide rod 23, the rotation of the drive screw 25 causes the nut member 24 to move forward. The first drive lens barrel 22 moves forward in synchronization. Further, the first key 36 fixed to the rear end portion of the first driving lens barrel 22 also moves forward together with the first driving lens barrel 22.

Since the drive transmission gear 12 is also meshed with the lens barrel drive gear 9, the drive transmission gear 12 is also rotated by the operation of the drive motor 6, and this drive transmission gear 12 is also rotated.
The second drive gear 13 meshing with 12 also rotates. Since the drive transmission gear 12 and the second drive gear 13 are provided at the rear end of the first drive lens barrel 22, the drive transmission gear 12 and the second drive gear 13 are moved forward together with the first drive lens barrel 22. At this time, the lens barrel drive gear 9 has its tooth width extended in the direction of the optical axis S.
The engagement between the lens barrel drive gear 9 and the lens barrel 12 will not be disengaged. Since the second drive gear 13 is fitted on the connecting shaft 29,
The connecting shaft 29 also rotates in synchronization with the second drive gear 13, and the driven gear 28 connected to the connecting shaft 29 also rotates in synchronization. The driven gear 28 meshes with an internal gear 27b formed on the inner peripheral surface of the second drive lens barrel 27, and the second drive lens barrel 27 is rotatably housed in the first drive lens barrel 22. Therefore, the rotation of the driven gear 28 causes the second drive lens barrel 27 to move to the optical axis S.
. The second driving lens barrel 27 is connected to the first driving lens barrel 22 via the helicoids 22f and 27a, and the second driving lens barrel 27 rotates with respect to the first driving lens barrel 22. The drive lens barrel 27 advances relative to the first drive lens barrel 22. Further, since the second key 37 linked to the rear end of the second drive lens barrel 27 is linked to the first key 36, the second key 37 does not rotate and the second drive lens barrel 27 does not rotate. It will move forward with respect to the first key 36 in synchronization with. Therefore, the second driving lens barrel 27 and the second key 37 are further advanced than the second driving lens barrel 22 and the first key 36, respectively. The driven gear 28 moves forward while sliding on the connecting shaft 29 together with the second drive lens barrel 22.

The second drive lens barrel 27 has helicoids 27c and 30a.
The movable lens barrel 30 is connected to the second key 37 that moves forward in the direction of the optical axis S by the guide protrusion 30b.
And the guide hole 37d, the movable lens barrel 30 advances with respect to the second driving lens barrel 27 by the rotation of the second driving lens barrel 27. The front lens group 31 is attached to the movable lens barrel 30.
Therefore, the front lens group 31 also moves forward together with the movable lens barrel 30. Further, since the rear lens group 32 is connected to the second key 37 and the second drive lens barrel 27, the movement amount is restricted by the rotation of the second drive lens barrel 27 and is guided by the guide slit 37e. It will move forward, Fig. 4
As shown in, the front lens group 31 and the rear lens group 32 are located at the forefront. The forward movement of the front lens group 31 and the rear lens group 32 is performed while maintaining a predetermined optical relationship, and the magnification is varied with the movement of the movable lens barrel 30.

When the output shaft of the drive motor 6 rotates in the opposite direction in the state shown in FIG. 4, the lens barrel drive gear 9 rotates in the opposite direction to that in the above-described operation. For this reason,
The first drive lens barrel 22 retracts with respect to the fixed lens barrel 21, the second drive lens barrel 27 retracts with respect to the first drive lens barrel 22, and the moving lens barrel 30 with respect to the second drive lens barrel 27. This means that the front lens group 31 and the rear lens group 32 are located at the rearmost position as shown in FIG.

In this embodiment, the linear driving means for moving the first driving lens barrel 22 with respect to the fixed lens barrel 21 is driven by a rotating driving screw 25 and a nut member screwed onto the driving screw 25.
Although the structure constituted by the combination with 24 has been described, the linear driving means can be constituted by another mechanism. For example, a rack portion may be formed in a part of the first drive lens barrel 22, a gear that meshes with the rack portion may be provided, and the gear may be rotated by the drive motor 6. That is, since the first driving lens barrel 22 is linearly moved in the direction of the optical axis S without rotating, the first driving lens barrel 22 is housed in the fixed lens barrel 21 and the second driving lens barrel 27 is If the rotation can be supported, desired components can be provided in the first driving lens barrel 22, or a part of the first driving lens barrel 22 can be cut out. Further, in the case where the drive gear 25 is not provided, the guide rod 23 is used as a guide means instead of the drive gear 25, and the washer 26 is attached to and detached from the guide rod 23 so that the initial focus described below is obtained. Can be adjusted.

The initial focus is adjusted by attaching and detaching the washer 26 to and from the drive screw 25. That is, the washer 26 is interposed between the first drive lens barrel 22 and the nut member 24, and the position of the nut member 24 is constant in the initial position. The position of the body 22 with respect to the nut member 24 is restricted. By adjusting the initial position of the first driving lens barrel 22, the initial focus position of the taking lens can be adjusted. Moreover, the drive screw 25 is disposed outside the first drive lens barrel 22, and a through hole can be formed in a portion of the fixed lens barrel 21 corresponding to the drive screw 25, so that the washer 26 is passed through the through hole. Can be attached and detached in a state where the first drive lens barrel 22 is incorporated in the fixed lens barrel 21, and the work of adjusting the initial focus can be easily performed. Further, since the washer 26 has the U-shaped notch 26a, the washer 26 can be easily attached and detached from the direction orthogonal to the drive screw 25. Then, by changing the thickness of the washer 26 and the number of mounted lenses, the focal point of the photographing lens is converged to a predetermined position when the first drive lens barrel 22 is located at the rear end portion and at the front end portion. To adjust.

Next, referring to FIGS. 7 and 8, the movable lens barrel 30
Another embodiment relating to a mechanism for guiding the advance / retreat of will be described. The same parts as those in the embodiment shown in FIGS. 1 to 6 are designated by the same reference numerals, and the description thereof will be omitted. FIG. 8 is an enlarged cross-sectional view of a part of the first driving lens barrel 22. On the inner surface of the first driving lens barrel 22, a guide groove 22g in a direction parallel to the optical axis direction is appropriately provided together with the helicoid 22f. The number is formed. On the other hand, at the rear end of the guide key 38 which is connected to the movable lens barrel 30 by the same structure as the second key 37, the guide groove 22g is formed.
A guide protrusion 38a is formed so as to be loosely inserted in the guide groove 38g, and the guide protrusion 38a is loosely inserted in the guide groove 22g to prevent the guide key 38 from rotating and guide the advance / retreat in the optical axis direction. I am doing it. The guide key 38 does not need the key opening 37c formed in the second key 37. The rear end of the guide key 38 is connected to the second drive lens barrel 27 so that it can move forward and backward together with the second drive lens barrel 27 in the optical axis direction. An annular mask plate 39 is attached to the rear end of the first driving lens barrel 22 to prevent the flare phenomenon caused by the subject light transmitted through the taking lens.

In the structure shown in FIGS. 7 and 8, the second
When the driving lens barrel 27 receives the power from the driving motor 6 and rotates, the second driving lens barrel 27 advances and retreats in the optical axis direction due to the connection with the first driving lens barrel 22 by the helicoids 22f and 27a. To do. As the second drive lens barrel 27 moves back and forth, the guide key 38 moves back and forth in the same direction. At this time, since the guide protrusion 38a of the guide key 38 is loosely inserted in the guide groove 22g formed on the inner surface of the first drive lens barrel 22, the guide key 38 is directly moved without rotating. And then go back and forth. That is, according to the embodiment shown in FIGS. 7 and 8, the first key 36 in the structure shown in FIGS. 1 to 6 is unnecessary, and the guide groove 22g formed in the inner surface of the first driving lens barrel 22 is used. Since the guide key 38 corresponding to the second key 37 is guided to move forward and backward, the number of parts can be reduced and the structure can be simplified.

[0034]

As described above, according to the initial focus adjustment mechanism of the camera with the variable focus lens device according to the present invention, the linear drive of the first drive lens barrel housed in the fixed lens barrel in the optical axis direction is performed. The initial focus position can be adjusted by changing the position of the first drive lens barrel on the optical axis by attaching and detaching the focus position adjusting member to the guide means for guiding. And
Since this guide means can be arranged outside the first driving lens barrel, the initial focus can be adjusted with the first driving lens barrel incorporated in the fixed lens barrel. Therefore, the work of adjusting the initial focus can be easily performed.

[Brief description of drawings]

FIG. 1 is a schematic exploded perspective view showing a mechanism for linearly operating a first driving lens barrel of a camera with a variable focus lens device having an initial focus adjustment mechanism according to the present invention.

FIG. 2 is a cross-sectional view of the rear surface of the camera provided with the initial focus adjustment mechanism of the camera with the variable focus lens device according to the present invention.

FIG. 3 is a cross-sectional plan view of a camera including an initial focus adjustment mechanism for a camera with a variable focus lens device according to the present invention.

FIG. 4 is a cross-sectional view taken along a vertical plane including an optical axis of a camera having an initial focus adjustment mechanism of a camera with a variable focus lens device according to the present invention, showing a state in which a taking lens has advanced to a forefront portion. .

FIG. 5 is a cross-sectional view taken along a vertical plane including an optical axis of a camera having an initial focus adjustment mechanism of a camera with a variable focus lens device according to the present invention, showing a state in which a taking lens has advanced to a frontmost position. .

FIG. 6 is an exploded perspective view for explaining a drive mechanism of a taking lens having an initial focus adjustment mechanism of a camera with a variable focus lens device according to the present invention.

7 is a view showing a mechanism according to another embodiment for guiding the movement of the movable lens barrel, and is a sectional view corresponding to FIG.

8 is an enlarged view of a main part of FIG. 7, in which a part is omitted.

[Explanation of symbols]

 1 Photographic lens 6 Drive motor 9 Lens drive gear 11 First drive gear 12 Drive transmission gear 13 Second drive gear 20 Camera body 21 Fixed lens barrel 22 First drive lens barrel 23 Guide rod 24 Nut member 25 Drive screw (guide Means) 26 Washer (focus position adjusting member) 26a Notch 27 Second drive lens barrel 30 Moving lens barrel 31 Front lens group 32 Rear lens group 36 First key 37 Second key

Claims (3)

[Claims] 1. A camera with a varifocal lens device having a photographic optical system for performing a zooming operation or a focusing operation by advancing and retracting a photographic lens in the optical axis direction, wherein the camera is housed in a fixed barrel and is driven by a linear driving means. A drive lens barrel which is guided by the guide means and moves forward and backward in the optical axis direction without rotating about the optical axis is provided to the fixed lens barrel, and a focus position adjusting member is detachably provided to the guide means. The initial position of the drive lens barrel with respect to the guide means is changed by attaching and detaching the focus position adjusting member with the drive lens barrel incorporated in the fixed lens barrel, thereby adjusting the initial focus. Initial focus adjustment mechanism for cameras with variable focus lens device. 2. The focus means for adjusting the focus position, wherein the guide means is formed by a drive screw having a male screw, and a female screw portion screwed with the drive screw is provided so as to be connected to a part of the drive lens barrel. 2. The initial focus adjustment mechanism for a camera with a variable focus lens device according to claim 1, wherein the position of the drive lens barrel with respect to the female screw portion is changed by attaching or detaching a member to adjust the initial focus. 3. The drive mirror by forming the focus position adjusting member by a washer having a U-shaped notch, and attaching and detaching the washer to and from the guide means in a direction intersecting the longitudinal direction thereof. 3. The initial focus adjustment mechanism for a camera with a variable focus lens device according to claim 1, wherein the initial focus is adjusted by changing the position of the barrel with respect to the female screw portion.