JPH06289473A - Flare preventing mask supporting structure for camera - Google Patents

Abstract

PURPOSE:To sufficiently prevent flare due to the transmission light of the peripheral part of a photographic lens by attaching a flare preventing mask into a key member moving less than the moving amount of a mobile lens-barrel even when a focal distance is changed by a variable focusing device driven by means of a helicoid to make the focal distance long. CONSTITUTION:A key plate 16 preventing the turn of the mobile lens-barrel 13 holding the photographic lenses 14 and 15 and guiding the advancing/retracting of the lens- barrel 13 is moved at speed almost equal to that of an intermediate lens-boarrel 12 and the flare preventing mask 33 is attached to the key plate 16. The intermediate lens-barrel 12 is linked with a fixed lens-barrel 11 via helicoids 11a and 12a and the mobile lens-barrel 13 through helicoids 12b and 13a. When the intermediate lens-barrel 12 is turned, the intermediate lens-barrel 12 and the mobile lens-barrel 13 are moved in the direction of an optical axis S with respect to the fixed lens-barrel 11 and the intermediate lens-barrel 12, respectively to change the focal distance. The moving quantity of the mobile lens-barrel 13 is lager than that of the intermediate lens-barrel 12 and even if the mobile lens-barrel 13 advanced up to the forefront, the key plate 16 is located in the side of an aperture 10a from the rear end part of the mobile lens-barrel 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flare prevention mask supporting structure for preventing a flare phenomenon caused by incident light on a photographing lens of a camera having a variable focus device such as a zoom lens device.

[0002]

2. Description of the Related Art In order that anyone can easily enjoy taking photographs, the focal length of the taking lens can be set to a long focal length (tele) and a short focal length (wide) without changing the lens. Cameras equipped with a variable focus device such as a so-called focus switching device that can be switched to, or a zoom device that can continuously change the focal length are in widespread use. In this type of camera with a variable focus device, since the constituent lenses are moved in the optical axis direction to change the focal length, the flare generation state differs depending on the position of the lens on the optical axis. In order to prevent flare on both the telephoto side and the wide side, a flare prevention mask is placed between the taking lens and the film, and the flare prevention mask also moves along the optical axis as the constituent lenses move. It is necessary to have a structure that moves in the direction.

FIG. 5 is a view showing a conventional supporting structure for a flare preventing mask of this type in a camera equipped with a zoom device. This zoom device includes a front lens group 1 and a rear lens group 2.
A helicoid 3a is formed on the outer peripheral surface of the movable lens barrel 3 holding the and
4b is formed in the intermediate lens barrel 4, and the intermediate lens barrel 4 is housed in the fixed lens barrel 5 in which the helicoid 5a is formed on the inner peripheral surface. The fixed barrel 5 is fixed to the camera body 6. Then, when the intermediate lens barrel 4 is rotated with respect to the fixed lens barrel 5, the intermediate lens barrel 4 moves in the optical axis S direction by the engagement of the helicoid 4b and the helicoid 5a. Further, the movable lens barrel 3 is accommodated in the intermediate lens barrel 4 by the engagement of the helicoid 4a and the helicoid 3a, and the movable lens barrel 3 is guided by a guide rod (not shown) to be prevented from rotating. Therefore, the rotation of the intermediate lens barrel 4 causes the movable lens barrel 3 to move in the optical axis S direction. The front lens group 1 is held at a predetermined position of the movable lens barrel 3,
The rear lens group 2 moves on the optical axis S by an amount different from the moving amount of the movable lens barrel 3 via a cam mechanism or the like. Therefore, by the movement of the movable lens barrel 3 in the optical axis S direction, the front lens group 1 and the rear lens group 2 move while maintaining a predetermined optical relationship, and the focal length changes.

The flare prevention mask 7 is attached to the rear end portion of the movable lens barrel 3, and accordingly moves along the optical axis S as the movable lens barrel 3 moves. FIG. 5 shows a state in which the photographing lens has advanced to the tele position. When the photographing lens is retracted to the wide position, the flare prevention mask 7 is positioned near the aperture 8.
Therefore, when the taking lens is in the tele position, the light transmitted through the outer peripheral portion of the taking lens is blocked by the flare prevention mask 7, and the light transmitted from the center of the taking lens to the peripheral portion reaches the film, and the wide angle is achieved. When in the position, the light transmitted through the center of the taking lens reaches the film. That is, flare is prevented according to the focal length of the taking lens.

[0005]

However, since the above-mentioned conventional flare prevention mask is attached to the movable lens barrel 3, it may be insufficient to prevent flare. That is, at the tele position of the taking lens shown in FIG. 5, since the movable lens barrel 3 is advanced to the foremost portion, the flare prevention mask 7 and the aperture 8 attached to the rear end portion of the movable lens barrel 3 are And the range of light that passes through the taking lens increases. If the flare prevention mask 7 is closer to the aperture 8 than the position shown in FIG.
The range of transmitted light becomes the center of the taking lens, and flare can be prevented more effectively. That is, flare can be prevented more effectively if the range of the photographing lens surrounded by the surface connecting the edge of the aperture 8 and the tip of the flare prevention mask 7 is small. If the flare prevention mask 7 is fixed immediately before the aperture 8, it functions sufficiently when the taking lens is in the wide position, but blocks the incidence of light on the film surface when the taking lens is in the tele position. There is a risk that

Therefore, the present invention provides a support structure for a flare preventing mask of a camera, which can surely prevent flare according to the focal length of the taking lens even when the focal length of the taking lens changes. It is an object.

[0007]

As a technical means for achieving the above object, a support structure for a flare preventing mask of a camera according to the present invention comprises a front lens group and a rear lens group held by a movable lens barrel. A lens is provided with a variable focus device that changes the focal length by moving along with the movement of the movable lens barrel in the optical axis direction, and the movement of the movable lens barrel is driven by engaging the movable lens barrel. In a camera having a key member for rotating the movable lens barrel about the optical axis and for preventing rotation of the movable lens barrel, in response to advance / retreat of the movable lens barrel,
It is characterized in that the key member is advanced and retracted in the optical axis direction by a movement amount smaller than the movement amount of the movable lens barrel, and a flare prevention mask is fixed to an appropriate position of the key member.

The movement of the key member can be performed by the power taken out by appropriately changing the speed from the midway of the power transmission path from the motor for driving the drive lens barrel to the drive lens barrel. Since the movement of the key member is sufficient to prevent the rotation of the movable lens barrel, it is not necessary to drive it at the same speed as the movable lens barrel by setting an appropriate length. Can be driven with a small stroke.

[0009]

When the movable lens barrel is retracted to the wide position, the key member is also retracted to the rearmost portion, so the flare prevention mask is located immediately before the aperture.
The light transmitted through the peripheral part of the taking lens on the wide side is blocked to prevent flare at the wide position.

When the movable lens barrel moves forward to the tele position, the key member also moves forward. However, since the moving amount of this key member is smaller than the moving amount of the moving lens barrel, the flare fixed to the key member is moved. The prevention mask is located closer to the aperture than the rear end of the movable lens barrel. For this reason, the light transmitted through the peripheral portion of the photographing lens is blocked, and flare at the tele position is effectively prevented.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A supporting structure for a flare preventing mask of a camera according to the present invention will be specifically described below with reference to the illustrated embodiments. In this embodiment, a camera equipped with a zoom device is mounted with a flare prevention mask.

1 and 2 are sectional views of the zoom device of this camera taken along a vertical plane including the optical axis S. FIG. 1 shows a wide position and FIG. 2 shows a tele position. ing. This zoom device includes a fixed lens barrel 11 fixed to the camera body 10, an intermediate lens barrel 12 as a drive lens barrel rotatably accommodated in the fixed lens barrel 11, and a movement accommodated in the intermediate lens barrel 12. The lens barrel 13 and a key plate 16 which is a key member for guiding the movement of the movable lens barrel 13 are mainly configured. A front group lens 14 is held at the front part of the movable lens barrel 13, and a rear group lens 15 is supported at the rear part thereof so as to be movable in the optical axis S direction with respect to the movable lens barrel 13. The movement of the rear lens group 15 with respect to the movable lens barrel is performed by a predetermined movement amount via a cam mechanism (not shown) or the like, and maintains a predetermined optical relationship with the front lens group 14. The focal length is changed. The aperture formed around the optical axis S of the camera body 10 is an aperture 10a.

A helicoid 11 is provided on the inner peripheral surface of the fixed lens barrel 11.
a is formed, and an outer helicoid 12a that meshes with the helicoid 11a is formed on the outer peripheral surface of the intermediate lens barrel 12. When the intermediate lens barrel 12 is housed in the fixed lens barrel 11, the outside It meshes with the helicoid 12a. An inner helicoid 12b is formed on the inner peripheral surface of the intermediate lens barrel 12, and the inner helicoid 12b is formed on the inner peripheral surface of the movable lens barrel 13.
A helicoid 13a that meshes with b is formed, and these inner helicoid 12b and helicoid 13a mesh with each other when the movable lens barrel 13 is housed in the intermediate lens barrel 12. Then, the key plate 16 is inserted into the inside of the intermediate lens barrel 12 and the movable lens barrel 13 from the rear end portion of the intermediate lens barrel 12, and as shown in FIG. The roller 17 provided inside is engaged.

3 and 4 are views for explaining the driving of the zoom device, FIG. 3 is a rear view of the intermediate lens barrel 12, and FIG. 4 is a bottom view of FIG. As shown in FIG. 3, the power of the motor 18 built in the camera body 10 is appropriately changed in speed via the gear train 19 and transmitted to the drive gear 20. An input gear 22 having a rotary shaft 21 in a direction parallel to the optical axis S meshes with the drive gear 20, and a guide gear 23 is provided coaxially with the input gear 22, and the guide gear 23 is the input gear. It is adapted to rotate in synchronization with the rotation of 22. This guide gear 23 is
As shown in FIG. 4, the rear end portion of the intermediate lens barrel 12 is formed to have a tooth width that is appropriately longer than a moving range to be described later.
A lens barrel drive gear 24 is meshed with 23. The lens barrel drive gear 24 meshes with the lens barrel gear 25 formed at the outer peripheral rear end of the intermediate lens barrel 12. Therefore, the motor 18
Is transmitted to the lens barrel gear 25 via the gear train 19, the drive gear 20, the input gear 22, the guide gear 23, and the lens barrel drive gear 24.

An operating gear 27 having a rotating shaft 26 in a direction parallel to the optical axis S is meshed with the input gear 22, and a driving screw 28 having an appropriate length is coaxial with the operating gear 27. The operation gear 27 and the drive screw 28 are provided so as to rotate in synchronization with each other about the rotation shaft 26. This drive screw 28
A drive nut 29 is screwed onto the drive nut 29, and the lens barrel drive gear 24 is rotatably provided on the drive nut 29 via a bearing 24a. In addition, the drive nut 29 has a key bracket 30
One side end of the key bracket is fitted.
The key plate 16 is attached to the upper end of the key bracket 30 so as to be integrated with the key bracket 30. A guide rod 31 extending in the direction of the optical axis S is provided on the opposite side of the rotary shaft 26 with the key plate 16 interposed therebetween.
The other end portion of the side of the key bracket 30 is slidably fitted and connected to the key bracket 30 to prevent the key bracket 31 from turning around the optical axis S.

A slider 41 is slidably fitted on the guide rod 31, and one end of the slider 41 is connected to the key bracket 30 via a locking pin 32.
Therefore, the slider 41 slides along the guide rod 31 along with the key bracket 30 and is prevented from rotating around the guide rod 31.
Further, a position sensor 42 is arranged beside the guide rod 31, and an input terminal 42 of the position sensor 42 is provided.
a is connected to a fork 41a formed on the slider 41. Also, this slider 41 and the key bracket 30
A leaf spring 43 is provided between the slider and the slider, and the slider 41 slides forward under the restoring force of the leaf spring 43.

As shown in FIGS. 1 and 2, a flare prevention mask 33 is attached to the rear end of the key plate 16. In this embodiment, the flare prevention mask 33
Is attached to the rear end of the key plate 16, but may be another part of the key plate 16. When attached to the rear end of the key plate 16 as in this embodiment, as shown in FIGS. 1 and 2, the outer peripheral edge of the flare prevention mask 33 is brought close to the inner peripheral surface of the fixed lens barrel 11. Can be arranged.
Therefore, the light reflected on the inner surface of the drive lens barrel 12 is prevented from reaching the aperture 10a, and flare due to this reflected light can be prevented.

The operation of the embodiment of the support structure for the flare preventing mask of the camera according to the present invention constructed as described above will be described below.

FIG. 1 shows the case where the zoom device is in the wide position, and the zoom drive of the taking lenses 14 and 15 is performed by a motor.
Driven by 18. The zoom device is of the rear focus type. When the motor 18 is driven, its rotation is transmitted to the drive gear 20 via the gear train 19. Since the input gear 22 meshes with the drive gear 20 and the operating gear 27 meshes with the input gear 22, the rotation of the drive gear 20 causes the input gear 22 and the operating gear 27 to rotate. Become.

Since the rotation shaft 21 of the input gear 22 is provided with the guide gear 23, the rotation of the input gear 22 causes the guide gear 23 to rotate.
23 will rotate. A lens barrel drive gear 24 meshes with the guide gear 23, and a lens barrel gear 25 meshes with the lens barrel drive gear 24. Therefore, the guide gear 23 rotates through the lens barrel drive gear 24. It is transmitted to the gear 25. Then, the lens barrel gear 25
Is formed on the outer peripheral surface of the intermediate lens barrel 12, so that the intermediate lens barrel 12 rotates. Further, the intermediate lens barrel 12 is a fixed lens barrel via the outer helicoid 12a and the helicoid 11a.
Since the fixed lens barrel 11 is connected to the camera body 10, the fixed lens barrel 11 is fixed to the camera body 10.
Moves in the optical axis S direction with respect to the fixed lens barrel 11. When the zoom device is in the wide position, the intermediate lens barrel
12 will move forward, and will retract if it is in the tele position.

On the other hand, when the operating gear 27 rotates, the drive screw 28 coaxially with the operating gear 27 also rotates.
The drive nut 29, which is screwed onto the drive nut 28, moves along the drive screw 28. The moving direction of the drive nut 29 is the same as the moving direction of the intermediate lens barrel 12, that is, it moves forward when the zoom device is in the wide position, and moves backward when the zoom device is in the tele position. . Further, in order that the moving speed of the drive nut 29 and the moving speed of the intermediate lens barrel 12 are substantially equal to each other, the relationship between the pitches of the drive screw 28 and the screw of the drive nut 29, the helicoid 11a, and the outer helicoid 12a.
The pitch relationship is defined.

When the intermediate lens barrel 12 is rotated, it is connected to the intermediate lens barrel 12 through the inner helicoid 12b and the helicoid 13a, and the roller 17 is engaged with the key plate 16 to rotate. The blocked movable lens barrel 13 moves in the direction of the optical axis S. The moving lens barrel 13 moves in the same direction as the intermediate lens barrel 12, that is, it moves forward when the zoom device is in the wide position, and moves backward when it is in the tele position. The moving amount of the movable lens barrel 13 is larger than the moving amount of the intermediate lens barrel 12, and is doubled in this embodiment.

Since the key plate 16 is provided integrally with the key bracket 30 fitted to the drive nut 29, when the drive nut 29 moves along the drive screw 28, the key plate 16 is moved.
Will also move in the same direction. And this key board 16
Is set to a length that does not drop from the roller 17 even when the movable lens barrel 13 moves to the frontmost part with respect to the intermediate lens barrel 12.

A lens barrel drive gear for driving the intermediate lens barrel 12
Since 24 is meshed with the guide gear 23 extending in the optical axis S direction, even when the lens barrel drive gear 24 moves along the drive screw 28, the lens barrel drive gear 24 and the guide gear 23 The mesh with is maintained. Moreover, since the moving speed of the drive nut 29 and the moving speed of the intermediate lens barrel 12 are substantially equal to each other, the engagement between the lens barrel drive gear 24 and the lens barrel gear 25 is maintained.

When the key plate 16 is in the wide position, the flare prevention mask 33 is located close to the aperture 10a as shown in FIG. The surface connecting the edge portion of the aperture 10a and the tip edge of the flare prevention mask 33 intersects with the taking lenses 14 and 15 in the vicinity of the optical axis S, so that the light passing through the peripheral portions of the taking lenses 14 and 15 does not pass through. It is blocked by the flare prevention mask 33 to prevent flare.

When the zoom device is moved to the tele position, the state shown in FIG. 2 is obtained, and the movable lens barrel 13 is at the forefront part of the intermediate lens barrel 12.
The intermediate lens barrels 12 are located at the frontmost portions of the fixed lens barrels 11, respectively. Further, the key plate 16 extends forward from the rear end portion of the intermediate lens barrel 12, and the front end portion thereof engages with a roller 17 provided inside the movable lens barrel 13. That is, the key plate 16 is a movable lens barrel.
The flare prevention mask 33, which is located closer to the aperture 10a than the rear end of the 13 and is attached to the key plate 16, is shown in FIG.
As shown by the solid line, it is located closer to the aperture 10a than the rear end of the movable lens barrel 13. In FIG. 2, the conventional flare prevention mask 7 attached to the movable lens barrel is also shown by imaginary lines, and each surface connecting the edge portion of the aperture 10a and the flare prevention mask 7 or the flare prevention mask 33. Causes a difference indicated by a symbol L in FIG. For this reason, the flare prevention mask 33 allows only light that has passed through a narrow area in the central portion of the taking lenses 14 and 15 to reach the aperture 10a, and allows light that has passed through the periphery of the taking lenses 14 and 15. It is possible to prevent flare.

Further, the slider 41 slidably fitted on the guide rod 31 with which the key bracket 30 is linked is connected to the key bracket 30.
As the slider moves forward and backward, the slider 41 also moves forward and backward.
Since the input terminal 41a of the position sensor 42 is connected to the slider 41, the position of the input terminal 41a with respect to the position sensor 42 changes as the slider 41 moves back and forth. Therefore, the output of the position sensor 42 changes, and the position of the key bracket 30, that is, the intermediate lens barrel 12 is detected by the magnitude of the output. Since the intermediate lens barrel 12 and the movable lens barrel 13 move forward and backward in a predetermined relationship, the position of the movable lens barrel 13 is detected by the position of the intermediate lens barrel 12, and the zoom position is detected. Based on the detected zoom position, C (not shown) mounted on the camera
The PU controls exposure and autofocus.

To change the state from the tele position to the wide position, the intermediate lens barrel 12 is rotated in the opposite direction to the case where the intermediate lens barrel 12 is changed to the tele position by, for example, reversing the motor 18. The rotation of the intermediate lens barrel 12 causes the movable lens barrel 13 to retract, and the intermediate lens barrel 12 to retract to the wide position shown in FIG.

[0029]

As described above, according to the support structure for the flare preventing mask of the camera of the present invention, the movement of the movable lens barrel is guided, and the movement amount of the movable lens barrel is smaller than that of the movable lens barrel. Since a flare prevention mask is provided on the key member that moves forward and backward in synchronization with the moving lens barrel, the flare prevention mask is positioned closer to the aperture side than the rear end of the moving lens barrel even when the taking lens is located on the long focus side. To position. Therefore, as compared with the case where the flare prevention mask is provided at the rear end of the movable lens barrel, the light transmitted through the periphery of the taking lens can be blocked and flare can be sufficiently prevented.

Further, when the taking lens is located on the short focus side, the flare prevention mask is located close to the aperture, so flare can be prevented even on the short focus side.

Moreover, since the flare prevention mask is attached to the key member, the camera has a simple structure, can effectively prevent flare without increasing the manufacturing cost, and provides a clear image of the photographed image. it can.

Further, when the flare prevention mask is attached to the rear end of the key member, the flare prevention mask is arranged by bringing the outer edge of the mask close to the inner surface of the driving lens barrel or the fixed lens barrel. Can be installed. For this reason, it is difficult to prevent flare due to the light reflected on the inner surface of the drive lens barrel or the fixed lens barrel with the conventional flare prevention mask attached to the rear end of the movable lens barrel. By extending the flare prevention mask to the inner surface of the lens barrel, flare due to reflected light on the inner surface can be effectively prevented.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a camera body having a flare prevention mask attached by a support structure according to the present invention, taken along a vertical plane including an optical axis, showing a state in which a taking lens is on a short focus side. ing.

FIG. 2 is a schematic cross-sectional view of a camera body having a flare prevention mask attached by the support structure according to the present invention, taken along a vertical plane including an optical axis, showing a state in which a taking lens is on a long focal length side. ing.

FIG. 3 is a rear view showing the main part of the camera body for explaining zoom driving and key member driving.

FIG. 4 is a bottom view of FIG.

5 is a cross-sectional view of a camera body showing a conventional support structure for a flare prevention mask, which is a view corresponding to FIG. 1. FIG.

[Explanation of symbols]

 10 Camera body 11 Fixed lens barrel 11a Helicoid 12 Intermediate lens barrel 12a Outer helicoid 12b Inner helicoid 13 Moving lens barrel 13a Helicoid 14 Front lens group 15 Rear lens group 16 Key plate (key member) 17 Roller 20 Drive gear 22 Input gear 23 Guide Gear 24 Lens barrel drive gear 25 Lens barrel gear 27 Actuating gear 28 Drive screw 29 Drive nut 30 Key bracket 31 Guide rod

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[Procedure amendment]

[Submission date] October 28, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction content]

1 and 2 are sectional views of the zoom device of this camera taken along a vertical plane including the optical axis S. FIG. 1 shows a wide position and FIG. 2 shows a tele position. ing. This zoom device includes a fixed lens barrel 11 fixed to the camera body 10, an intermediate lens barrel 12 as a drive lens barrel rotatably accommodated in the fixed lens barrel 11, and a movement accommodated in the intermediate lens barrel 12. The lens barrel 13 and a key plate 16 which is a key member for guiding the movement of the movable lens barrel 13 are mainly configured. A front group lens 14 is held at the front part of the movable lens barrel 13, and a rear group lens 15 is supported at the rear part thereof so as to be movable in the optical axis S direction with respect to the movable lens barrel 13. The rear lens group 15 is moved with respect to the movable lens barrel by a predetermined amount, and the focal length is changed while maintaining a predetermined optical relationship with the front lens group 14. The aperture formed around the optical axis S of the camera body 10 is an aperture 10a.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction content]

A helicoid 11 is provided on the inner peripheral surface of the fixed lens barrel 11.
a is formed, and an outer helicoid 12a that meshes with the helicoid 11a is formed on the outer peripheral surface of the intermediate lens barrel 12. When the intermediate lens barrel 12 is housed in the fixed lens barrel 11, the outside It meshes with the helicoid 12a. Further, the inner peripheral surface of the intermediate lens tube 12 inner helicoid 12b is formed, the inner helicoid 12 in the outer peripheral surface of the moving lens barrel 13
A helicoid 13a that meshes with b is formed, and these inner helicoid 12b and helicoid 13a mesh with each other when the movable lens barrel 13 is housed in the intermediate lens barrel 12. The key plate 16 is inserted into the intermediate lens barrel 12 and the movable lens barrel 13 from the rear end portion of the intermediate lens barrel 12, and rollers provided inside the movable lens barrel 13 on both sides of the key plate 16. 17 engaged. This
The roller 17 of the bracket is fixed to the rear end of the movable lens barrel 13 as a bracket.
The guide part 34a formed at the bottom of the
It is rotatably supported by the shaft pin 35 that is planted.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0016

[Correction method] Change

[Correction content]

[0016] The slider 41 to the guide rod 31 is loosely fitted slidably, one end of the slider 41 is communicated tied to the key bracket 30 via a locking pin 32.
Therefore, the slider 41 slides along the guide rod 31 along with the key bracket 30 and is prevented from rotating around the guide rod 31.
Further, a position sensor 42 is arranged beside the guide rod 31, and an input terminal 42 of the position sensor 42 is provided.
a is connected to a fork 41a formed on the slider 41. Also, this slider 41 and the key bracket 30
A leaf spring 43 is interposed between the slider and the slider, and the slider 41 slides forward under the restoring force of the leaf spring 43.
The abutment tongue 41b formed on a part of 41 is as shown in FIG.
In addition, the rear end of the intermediate lens barrel 12 is always abutted .

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0026

[Correction method] Change

[Correction content]

When the zoom device is moved to the tele position, the state shown in FIG. 2 is obtained, and the movable lens barrel 13 is at the forefront part of the intermediate lens barrel 12.
The intermediate lens barrels 12 are located at the frontmost portions of the fixed lens barrels 11, respectively. Further, the tip of the key plate 16 is engaged with a roller 17 provided inside the movable lens barrel 13. That is, the key plate 16 is located in aperture 10a side than the rear end portion of the moving lens barrel 13, the anti-flare mask 33 attached to the key plate 16, as shown in FIG. 2, the movement barrel 13 It is located closer to the aperture 10a than the rear end. In FIG. 2, the conventional flare prevention mask 7 attached to the movable lens barrel is also shown by imaginary lines, and each surface connecting the edge portion of the aperture 10a and the flare prevention mask 7 or the flare prevention mask 33. Causes a difference indicated by a symbol L in FIG. Therefore, with the flare prevention mask 33, only the light that has passed through the narrow range of the central portions of the taking lenses 14 and 15 can be used.
It is possible to prevent the flare due to the light transmitted through the periphery of the taking lenses 14 and 15.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Name of item to be corrected] 0027

[Correction method] Change

[Correction content]

Further, the slider 41 that the key bracket 30 is loosely fitted slidably on the guide rod 31 in tandem, since being communicated tied to the key bracket 30, the key bracket
As the slider moves forward and backward, the slider 41 also moves forward and backward.
Since the input terminal 41a of the position sensor 42 is connected to the slider 41, the position of the input terminal 41a with respect to the position sensor 42 changes as the slider 41 moves back and forth. Therefore, the output of the position sensor 42 changes, and the position of the key bracket 30, that is, the intermediate lens barrel 12 is detected by the magnitude of the output. Since the intermediate lens barrel 12 and the movable lens barrel 13 move forward and backward in a predetermined relationship, the position of the movable lens barrel 13 is detected by the position of the intermediate lens barrel 12, and the zoom position is detected. Based on the detected zoom position, C (not shown) mounted on the camera
The PU controls exposure and autofocus.

[Procedure correction 6]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 1

[Correction method] Change

[Correction content]

[Figure 1]

[Procedure Amendment 7]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 2

[Correction method] Change

[Correction content]

[Fig. 2]

[Procedure Amendment 8]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 3

[Correction method] Change

[Correction content]

[Figure 3]

[Procedure Amendment 9]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 4

[Correction method] Change

[Correction content]

[Figure 4]

Claims (1)

[Claims] 1. A variable focus device for changing a focal length by moving a front lens group and a rear lens group held by a movable lens barrel as the movable lens barrel moves forward and backward in the optical axis direction. A camera having a key member for moving the movable lens barrel by rotating the drive lens barrel engaged with the movable lens barrel about an optical axis, and for preventing the movable lens barrel from rotating. In response to the movement of the movable lens barrel, the key member is moved in the optical axis direction by a movement amount smaller than the movement amount of the movable lens barrel, and a flare prevention mask is fixed to an appropriate position of the key member. A support structure for a mask for preventing flare of a camera.