JP3209011B2 - Driving force transmission mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving force transmitting mechanism in a lens barrel of a camera. More specifically, the present invention relates to a mechanism that performs transmission by a member that rotates around an optical axis, such as a transmission mechanism of a stop.

[0002]

2. Description of the Related Art Hitherto, in a lens barrel used for a camera, a configuration in which a driving force is transmitted by rotation, such as driving a diaphragm, is known. First, the configuration will be described according to the configuration of FIG. FIG. 2 is an exploded view of an essential part for easier understanding. Further, in the drawings, the details of the external parts and the optical system of the lens barrel, which are not particularly related to the present invention, are omitted, and the camera and the like are not shown, but they have a known configuration. In the figure, the left is the front of the lens barrel, that is, the object side, and the right is the rear of the lens barrel, that is, the camera side.

First, a non-rotatable aperture ring (1) and a stop drive ring (5) rotatable about the optical axis of the optical system are provided at the front of the lens barrel, that is, on the left side of the figure. And a predetermined number of aperture blades (2) sandwiched between both rings
Is installed. When the aperture driving ring (5) rotates with respect to the aperture ring (1), the aperture blade (2) rotates, and an aperture value is set according to the rotation angle. The aperture ring (1), the aperture drive ring (5), and the aperture blade (2) are provided so as to be integrally movable with respect to the optical axis direction, and light is transmitted according to operations such as zooming of the lens barrel. Move in the axial direction. on the other hand,
From the aperture driving ring (5), a first transmission lever (19) for transmitting a driving force for rotating the same extends along the optical axis toward the rear of the lens barrel.

On the other hand, a preset ring (12) for transmitting a stop-down instruction from the camera to the stop drive ring (5) is provided at the rear of the lens barrel, that is, on the right side of the figure. The preset ring (12) is installed so as to be rotatable only about the optical axis, and is biased by a spring (11) in a predetermined rotation direction.

A drive lever (21) extends rearward from the preset ring (12), and the aperture is driven by operating the drive lever (21) from the camera side. The spring (11) urges the diaphragm in either the direction of opening the diaphragm or the direction of decreasing the diaphragm in accordance with the configuration of the camera. In the former case, the drive lever (21) is moved from the camera side to the drive lever (21). By transmitting the driving force in the narrowing direction, the narrowing is performed. In the latter case, the drive lever (21) is previously held at the aperture open position from the camera side, and the holding is released, whereby the aperture is narrowed down by the urging force of the spring (11). In the drawing, (10) is a guide member for holding the spring (11).

Further, a second transmission lever (20) extends forward from the preset ring (12). The front end of the second transmission lever (20) forms a fork (24) extending in the inner circumferential direction of the lens barrel. The first transmission lever (19) is inserted through the fork (24). I have. Thus, when the second transmission lever (20) rotates about the optical axis, the rotation is transmitted to the first transmission lever (19) via the fork portion (24), but the first transmission When the lever (19) moves straight along the optical axis, no movement is transmitted because both levers slide by the fork portion (24).

On the other hand, a lens frame (9) for holding a lens (16) is provided between the preset ring (12) and the aperture drive ring (5). A cut-out portion (18) through which the first transmission lever (19) or the second transmission lever (20) passes is formed on the outer periphery of the lens frame (9).

In such a configuration, when the driving force from the camera is applied to the driving lever (21) or the holding force applied to the driving lever (21) is released, the spring (11) is released. A driving force in the rotating direction is applied to the preset ring (12) against or by the urging force of the second ring, and the driving force is transmitted to the preset ring (20) through the second transmission lever (20) and the fork portion (24). It is transmitted to one transmission lever (19). As a result, the aperture driving ring (5) is rotated, and the aperture blade (2) is operated to perform aperture reduction.

[0009]

In the above configuration, the first and second transmission levers (19) and (20) rotate about the optical axis, so that they do not hinder the rotation. The notch (18) formed on the outer periphery of the lens frame (9) must be formed to have a size larger than the rotation angle of both levers. Therefore, there is a problem in that light leaks through a vacant portion (a portion through which the lever does not pass) of the notch (18). Therefore, there is a problem that a flare occurs due to the leaked light beam.

It is an object of the present invention to provide a lens barrel of a camera capable of efficiently removing this light leakage and taking clear pictures without flare.

[0011]

In order to achieve the above object, the present invention is directed to a lens barrel having an operating mechanism for transmitting drive by rotating about an optical axis. An element, a driving force transmitting means extending in the optical axis direction across the front and rear of the lens barrel component, and installed to be rotatable around the optical axis, and to allow the driving force transmitting means to rotate. A cutout portion formed in the lens barrel component, an opening through which the driving force transmitting means passes, and a light shielding portion for light shielding the cutout portion other than the opening; A light-shielding member installed so as to be able to rotate with movement is provided.

According to a second aspect of the present invention, in the configuration of the first aspect, the light shielding member is rotatably installed by fitting the light shielding member to the lens barrel constituent element.

According to a third aspect of the present invention, in the configuration of the first aspect, the light shielding member is formed around the entire optical axis.

According to a fourth aspect of the present invention, in the configuration of the first aspect, the driving force transmitting means is formed by a first member and a second member which move relatively in the optical axis direction, and the light shielding member is The first member and the second member are also relatively movable with respect to the optical axis direction, and also serve as connecting means for connecting the first member and the second member such that they cannot rotate relative to each other.

Further, according to the invention of claim 5, in the configuration of claim 1, the light shielding member is provided with a shielding member.

On the other hand, according to a sixth aspect of the present invention, there is provided a lens barrel having an operating mechanism for transmitting a drive by rotating about an optical axis, wherein the lens barrel includes a lens barrel and a lens barrel. A driving force transmitting unit extending in the optical axis direction and rotatably installed around the optical axis; and a notch formed in the lens barrel component to allow the driving force transmitting unit to rotate. And an opening through which the driving force transmission means passes, and is formed so as to shield the notch portion from light other than the opening, so that the driving force transmission means can be rotated with the rotation of the driving force transmission means. Being installed,
A light shielding member having an inner peripheral surface formed to prevent unnecessary light generated on an outer peripheral portion of the lens effective light beam.

According to a seventh aspect of the present invention, in the configuration of the sixth aspect, the light shielding member is rotatably installed by fitting the light shielding member to the lens barrel constituent element.

According to an eighth aspect of the present invention, in the configuration of the sixth aspect, the light shielding member is formed around the entire optical axis.

According to a ninth aspect of the present invention, in the configuration of the sixth aspect, the driving force transmitting means is formed by a first member and a second member which relatively move in the optical axis direction, and Is also capable of relatively moving the first member and the second member in the direction of the optical axis, and also serves as connecting means for connecting the first member and the second member such that they cannot rotate relative to each other.

Further, according to the tenth aspect, in the sixth aspect,
In the above configuration, the light shielding member is provided with a shielding member.

[0021]

According to the structure of the present invention, since light passing through the notch formed in the lens barrel component is blocked by the light shielding member, unnecessary light does not enter. More specifically, in the first aspect of the present invention, when the driving force transmitting means rotates, the light blocking member also rotates with the rotation, so that the transmission of the driving force is not hindered. Does not pass, so that unnecessary light does not enter. According to the second aspect of the present invention, the light-shielding member can be installed without requiring a special holding member or the like because the light-shielding member is fitted to the lens barrel component. In addition, since it is arranged close to the notch, unnecessary light can be more effectively prevented. According to the third aspect of the present invention, since the light shielding member is formed over the entire optical axis, light rays obliquely incident from the cutout can be effectively shielded. According to the fourth aspect of the present invention, since the light shielding member also serves as a connecting means of the driving force transmitting means, the light shielding member can be installed without increasing the number of members.
According to the fifth aspect of the present invention, the light incident from a small gap between the opening of the light shielding member and the driving force transmitting means is effectively shielded by the shielding member, and harmful light is prevented by the end face of the opening and the driving force transmitting means. Can be prevented.

According to the sixth aspect of the present invention, when the driving force transmitting means rotates, the light shielding member also rotates.
The transmission of the driving force is not hindered, and unnecessary light does not enter because light does not pass through other than the opening. Further, the inner peripheral surface of the light-shielding member prevents unnecessary light generated on the outer periphery of the effective light beam, thereby effectively preventing the image quality from deteriorating. In the invention of claim 7, the light-shielding member can be installed without requiring a special holding member or the like because the light-shielding member is fitted to the lens barrel component. In addition, since it is arranged close to the notch, unnecessary light can be more effectively prevented. According to the eighth aspect of the present invention, since the light blocking member is formed over the entire optical axis, light rays obliquely incident from the cutout can be effectively blocked. According to the ninth aspect of the present invention, since the light shielding member also serves as a connecting means of the driving force transmitting means, the light shielding member can be installed without increasing the number of members. In the invention according to claim 10, furthermore, light rays incident from a small gap between the opening of the light shielding member and the driving force transmitting means are effectively shielded by the shielding member, and harmful light is prevented by the end face of the opening and the driving force transmitting means. Can be prevented.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A description will now be given, with reference to the drawings, of an aperture mechanism for a lens barrel according to an embodiment of the present invention. FIG. 1 shows an aperture mechanism according to the present invention, and is an exploded view similar to the prior art shown in FIG. In this figure, components having the same configuration as that of the prior art shown in FIG. In the figure, the left side is in front of the lens barrel,
That is, the object side, and the right side is behind the lens barrel, that is, the camera side. In the figure, the external parts of the lens barrel and the details of the optical system which are not particularly related to the present invention are omitted, and the camera and the like are not shown, but they have a known configuration.

First, a non-rotatable aperture ring (1) and an aperture drive ring (5) rotatable about the optical axis of the optical system are provided at the front of the lens barrel. And a predetermined number of aperture blades (2) are disposed therebetween.
A pair of drive shafts (3, 3) extending forward and rearward of the blade (2) are implanted in each aperture blade (2) so that their axes are parallel and do not coincide with each other. A drive shaft (3) extending forward of the blade (2) is engaged with a hole (4) formed in the aperture ring (1), while a drive shaft (3) extending rearward is connected to the aperture drive ring (3). It is fitted in the cam groove (6) formed in 5). Therefore, the aperture drive ring (5)
Is rotated by the cam groove (6) to drive the rear drive shaft (3).
Is driven, and the aperture blade (3) rotates around the hole (4). Thus, the aperture is stopped down and the aperture is opened. The rotation angle of the aperture driving ring (5) determines the rotation angle of the aperture blade (2), and the aperture diameter is determined.

The aperture ring (1), the aperture drive ring (5), and the aperture blade (2) are provided so as to be integrally movable in the optical axis direction, and perform zooming and focusing of the lens barrel. Move in the optical axis direction in accordance with an operation for generating a special effect or the like. On the other hand, from the aperture drive ring (5), a first transmission lever (13) for transmitting a driving force for rotating the aperture drive ring (5) is provided.
It extends along the optical axis and toward the rear of the lens barrel.

On the other hand, in the figure, a preset ring (12) for transmitting an aperture stop instruction from the camera to the aperture drive ring (3) is provided at the rear of the lens barrel. The preset ring (12) is installed so as to be rotatable only about the optical axis, and is urged by a spring (11) in a predetermined rotation direction.

A drive lever (21) extends rearward from the preset ring (12), and the aperture is driven by operating the drive lever (21) from the camera side. The spring (11) urges the diaphragm in either the direction of opening the diaphragm or the direction of decreasing the diaphragm in accordance with the configuration of the camera. In the former case, the drive lever (21) is moved from the camera side to the drive lever (21). By transmitting the driving force in the narrowing direction, the narrowing is performed. In the latter case, the drive lever (21) is previously held at the aperture open position from the camera side, and the holding is released, whereby the aperture is narrowed down by the urging force of the spring (11). In the drawing, (10) is a guide member for holding the spring (11).

Further, a second transmission lever (14) extends forward from the preset ring (12). The front end of the second transmission lever (14) is superimposed on the first transmission lever (13), and is separated from the first transmission lever (13) even when the aperture driving ring (5) has moved to the front. Not just long.

On the other hand, a lens frame (9) for holding a lens (16) is provided between the preset ring (12) and the aperture driving ring (5). A cutout (18) through which the first transmission lever (13) or the second transmission lever (14) passes is formed on the outer periphery of the lens frame (9). In the lens frame (9),
As shown in FIG. 6, the shaft (2) of the cam follower pin (25)
6) are implanted in three places, and the cam follower pin (25) is fitted to the cam (15a) formed on the cam ring (15) shown in FIG. 1, and the cam ring (15) operates. By doing so, the lens frame (9) operates in the optical axis direction. The movement of the aperture ring (1), the aperture drive ring (5) and the aperture blade (2) in the optical axis direction may be interlocked with the movement of the lens frame (9), or may be independent of each other. It may be a movement that occurs.

A guide portion (17) having a circular shape is formed on the outer periphery of the front portion of the lens frame (9) toward the outside, and the front portion has a smaller diameter than the guide portion (17). An external thread (27) is formed. Guide unit (17)
Is fitted with an inner periphery of an interlocking ring (8) also serving as a light shielding portion. Furthermore, the female thread (7a) of the holding ring (7) is screwed into the male thread (27) from the front with the interlocking ring (8) fitted. In this state, the interlocking ring (8) is rotatable along the guide portion (17), but does not come off in the optical axis direction because of the holding ring (7).

On the other hand, the interlocking ring (8) has the first
And a passage opening (8a) large enough to allow the second and third transmission levers (13, 14) to pass therethrough, in which the first and second transmission levers (13, 14) are superimposed. Penetrates.

FIG. 4 shows the above state. When the second transmission lever (14) rotates, the first transmission lever (13) also rotates via the interlocking ring (8). That is, the interlocking ring (8) also functions as a connecting means for connecting the levers (13, 14) in the rotational direction.

In such a configuration, when the driving force from the camera is applied to the driving lever (21) or the holding force applied to the driving lever (21) is released, the spring (11) is released. A driving force in the rotating direction is applied to the preset ring (12) against or by the urging force of the second transmission lever (14) and the passing force of the second transmission lever (14) and the interlocking ring (8). 8a) to the first transmission lever (13). This allows
The aperture driving ring (5) is rotated, and the aperture blade (2) is operated to stop down. At this time,
Both transmission levers (13, 14) can rotate by the opening angle of the notch (18) formed in the lens frame (9), and with the rotation, the interlocking ring (8) also rotates. To rotate, the notch (18) other than the portion through which both transmission levers (13, 14) pass is closed by the interlocking ring (8). Therefore, light does not leak from the cutout portion (18), and the problem that a flare occurs unlike the related art does not occur.

Although the rotation angle of the preset ring (12) is determined by a well-known mechanism on the camera side or a mechanism such as a stopper in the lens barrel, it is not related to the gist of the present invention. Is omitted.

FIG. 3 shows a modification of the above embodiment, in which an anti-reflection plate (22) is provided on the interlocking ring (8). The anti-reflection plate (22) is connected to the passage opening (8) of the interlocking ring (8).
a), and is located at a position just inside
a) and the light passing through a small gap between the first and second transmission levers (13, 14) is prevented from entering the inside, and conversely, the light rays inside the lens barrel are transmitted by the transmission levers (13, 14).
14) and harmful light that is scattered by the end face of the passage opening (8a) is prevented. Furthermore, the anti-reflection plate (22) is colored with a low-reflectance paint, planted, or adhered to the anti-reflection plate (22) with a member such as a light-shielding paper (23). The function of prevention can be enhanced.

FIG. 5 shows a further modification of the above embodiment.
The relationship between the interlocking ring and the holding ring with respect to the lens frame is reversed inside and outside. That is, a guide part (117) having a circular shape is formed inward on the inner periphery of the front part of the lens frame (119), and further, the guide part (117) is provided on the front part.
A female screw portion (127) having a diameter larger than that of the female screw portion is formed. An interlocking ring (1) serving also as a light-shielding portion is provided on the guide portion (117).
08) is fitted. In addition, the interlocking ring (1
08) with the holding ring (10
7) The male screw part (107a) is the female screw part (127)
Screwed into. In this state, the interlocking ring (108)
Is rotatable along the guide portion (117), but does not separate in the optical axis direction. In the above configuration, the other configuration and the operation are completely the same as those in the above-described embodiment, and thus description thereof is omitted. At this time, since the inner diameter of the interlocking ring (108) faces the optical path of the lens (116), it is possible to have a function as a so-called flare cutter for preventing harmful light.

In the embodiment described above, the interlocking ring also has the function of connecting the transmission levers to each other. Regardless of this, the connection is performed by another structure such as a fork portion as in the prior art. Alternatively, it may be one that exclusively performs the function of preventing light leakage. Further, in the above embodiment, the aperture ring, the aperture drive ring, and the aperture blade operate in the optical axis direction. Therefore, the transmission lever is also divided into two members, but each member does not operate in the optical axis direction. In this case, the transmission lever may not be divided (the preset ring and the aperture drive lever may be directly connected).

In addition, in the above-described embodiment, the structure of the lens barrel has been shown to be simple in order to simplify the description and facilitate understanding. However, it is needless to say that a lens barrel having a further additional structure may be used. It goes without saying that the technical idea of the present invention can be applied. For example, in the above embodiment, the drive lever is operated from the camera side, but may be driven via another lever, ring, or the like. Further, an actuator may be provided in the lens barrel, and the driving lever may be operated by the driving force.

Further, in the above-described embodiment, the light leaking through the notch formed in the lens frame for holding the lens is prevented, but it is needless to say that the light is prevented from being formed on other members installed in the lens barrel. It is also possible to prevent light from leaking from a portion corresponding to the notch portion, and in that case, the interlocking ring may be installed not on the lens frame but on another member. Also, the interlocking ring may not be formed over the entire circumference around the optical axis, but may be formed so as to block light only in the vicinity of the notch. Furthermore, each of the above modifications can be configured not in isolation but in combination with each other.

[0040]

According to the structure of the present invention, since light passing through the cutout formed in the lens barrel component is blocked by the light blocking member, unnecessary light does not enter. More specifically, according to the first aspect of the present invention, when the driving force transmitting means rotates, the light shielding member also rotates, so that the transmission of the driving force is not hindered, and the driving force is transmitted through the opening. Unnecessary light does not enter because light does not pass through portions other than the portion where the transmission means penetrates. According to the second aspect of the present invention, the light-shielding member can be installed without requiring a special holding member or the like because the light-shielding member is fitted to the lens barrel component. In addition, since the light blocking member is disposed in close contact with the notch, unnecessary light can be more effectively prevented. According to the third aspect of the present invention, since the light blocking member is formed over the entire optical axis, light obliquely incident from the notch can be effectively shielded and incident through a portion other than the notch. Light can be blocked. According to the fourth aspect of the present invention, since the light shielding member also serves as a connecting means of the driving force transmitting means, the light shielding member can be installed without increasing the number of members. In particular, since the connecting means is configured to be in close contact with the driving force transmitting means with high precision without play, a high light shielding ability can be provided.

According to the fifth aspect of the present invention, light rays incident from a slight gap between the opening of the light shielding member and the driving force transmitting means are effectively shielded by the shielding member.
It is also possible to prevent the inside light beam from being scattered by the end face of the opening or the driving force transmitting means and becoming harmful light.

According to the sixth aspect of the present invention, when the driving force transmitting means rotates, the light shielding member also rotates.
The transmission of the driving force is not hindered, and unnecessary light does not enter because light does not pass through the opening other than the portion where the driving force transmitting means penetrates. Further, the inner peripheral surface of the light-shielding member prevents unnecessary light generated on the outer periphery of the effective light beam, thereby effectively preventing the image quality from deteriorating. In the invention of claim 7, the light-shielding member can be installed without requiring a special holding member or the like because the light-shielding member is fitted to the lens barrel component. In addition, since the light blocking member is disposed in close contact with the notch, unnecessary light can be more effectively prevented. According to the eighth aspect of the present invention, the light shielding member is formed over the entire optical axis, so that light rays obliquely incident from the notch can be effectively shielded and incident through portions other than the notch. Light can be blocked. In the invention of claim 9, further,
Since the light shielding member also serves as the connecting means of the driving force transmitting means, it can be installed without increasing the number of members. In particular, since the connecting means is configured to be in close contact with the driving force transmitting means with high precision without play, a high light shielding ability can be provided. According to the tenth aspect of the present invention, the light rays entering from a small gap between the opening of the light shielding member and the driving force transmitting means are also effectively shielded by the shielding member, and the inner light rays are blocked by the end face of the opening and the driving force transmitting means. Can be prevented from being harmful due to scattering.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a lens barrel showing an embodiment of the present invention.

FIG. 2 is an exploded perspective view of a conventional lens barrel.

FIG. 3 is an essential part perspective view showing a first modification of the embodiment.

FIG. 4 is a sectional view of a main part of the embodiment.

FIG. 5 is a sectional view of a main part showing a second modification of the embodiment.

FIG. 6 is a partial perspective view of the embodiment.

[Explanation of symbols]

8: light shielding member, connecting means 9, 16: lens barrel constituent elements (first member, second member) 13, 14: driving force transmitting means 18: notch 22: shielding member

Claims (10)

(57) [Claims] 1. A lens barrel having an operating mechanism for transmitting a drive by rotating about an optical axis, comprising: a lens barrel component; and an optical axis direction extending before and after the lens barrel component. A driving force transmitting means installed rotatably around the optical axis; and a notch formed in the lens barrel component to allow the driving force transmitting means to rotate. A light-shielding member having an opening through which the driving force transmission means passes and which is formed so as to shield the notch portion from light outside the opening, and which is installed so as to be rotatable with the rotation of the driving force transmission means; A driving force transmission mechanism comprising: 2. The driving force transmission mechanism according to claim 1, wherein the light shielding member is rotatably installed by fitting to the lens barrel constituent element. 3. The driving force transmission mechanism according to claim 1, wherein the light blocking member is formed around the entire optical axis. 4. The driving force transmitting means is formed by a first member and a second member which relatively move in the optical axis direction, and the light shielding member connects the first member and the second member to the optical axis. 2. The driving force transmission mechanism according to claim 1, wherein said driving force transmission mechanism also serves as a connecting means for connecting the movable member relative to the direction so as to be relatively movable and relatively unrotatable. 5. The driving force transmission mechanism according to claim 1, wherein a shielding member is provided on the inner peripheral side of the opening in the light shielding member. 6. A lens barrel having an operation mechanism for transmitting drive by rotating about an optical axis, comprising: a lens barrel component; and an optical axis direction extending before and after the lens barrel component. A driving force transmitting means installed rotatably around the optical axis; and a notch formed in the lens barrel component to allow the driving force transmitting means to rotate. It has an opening through which the driving force transmission means passes and is formed so as to shield the notch portion from light other than the opening, and is installed so as to be rotatable with the rotation of the driving force transmission means, A light transmitting member having an inner peripheral surface formed to prevent unnecessary light generated on an outer peripheral portion of the lens effective light beam. 7. The driving force transmission mechanism according to claim 6, wherein the light shielding member is rotatably installed by fitting to the lens barrel component. 8. The driving force transmission mechanism according to claim 6, wherein the light blocking member is formed around the entire optical axis. 9. The driving force transmitting means is formed by a first member and a second member which relatively move in an optical axis direction, and the light shielding member connects the first member and the second member to the optical axis. 7. The driving force transmission mechanism according to claim 6, wherein said driving force transmission mechanism also serves as a connecting means for connecting the movable member relative to each other so as to be relatively movable in the direction. 10. The driving force transmission mechanism according to claim 6, wherein a shielding member is provided on an inner peripheral side of the opening in the light shielding member.