JP3676518B2 - Lens frame with variable aperture mechanism of camera - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a lens barrel with a variable aperture mechanism capable of changing the size of a light beam passing through a photographing lens optical system of a camera.
[0002]
[Prior art]
In general, in a lens shutter camera, a shutter blade that is a first sector that opens and closes an exposure aperture to perform exposure control, and a variable aperture that is a second sector that varies the aperture diameter that determines the size of a light beam passing therethrough. 2. Description of the Related Art A configuration having a blade and a photographing lens optical system is known. In this case, the shutter blades are always fully open, the size of the passing light beam is determined by the aperture of the variable diaphragm blades according to the set aperture value, and the exposure amount is controlled by combining both.
[0003]
In addition to a shutter blade that also functions as a diaphragm blade, the shutter controls the exposure amount by combining the aperture diameter and the opening / closing speed, and the maximum luminous flux diameter is changed separately from the shutter according to the variable focal length of the photographing lens. Some lens shutter cameras have diaphragm blades for regulating the maximum aperture diameter.
A variable aperture mechanism of this type of conventional camera will be described with reference to a cross-sectional view of the main part of the taking lens barrel shown in FIG. 7. A front lens 105 is fixed to the lens frame 101, and the rear lens 5 has a rear side. A shutter holding member 102 is fixed to the lens frame 101. The shutter holding member 102 has shutter blades 103A and 103B rotatably supported on the support shafts 102a and 102b, respectively, and further on the rear side, for changing the aperture diameter of the aperture for determining the aperture light flux or maximum Variable aperture blades 104A and 104B for restricting the maximum aperture diameter by changing the light beam diameter are rotatably supported on the support shafts 102c and 102d. Although not shown, a rear lens is fixed to the lens frame 101 behind the shutter holding member 102. Here, as shown in FIG. 7, the shutter blades 103 </ b> A and 103 </ b> B and the variable diaphragm blades 104 </ b> A and 104 </ b> B are avoided so that the blade operating surfaces perpendicular to the optical axis do not wrap around the front lens 105 in the optical axis direction. Placed in.
[0004]
[Problems to be solved by the invention]
However, in such an arrangement, the front lens 105 and the rear lens (not shown) and the shutter holding member are larger than the thickness dimension in the optical axis direction occupied by the shutter blades 103A and 103B and the variable diaphragm blades 104A and 104B. Therefore, there is a problem in that it is impossible to make the lens frame compact by reducing the distance between both lenses further, and to increase the degree of freedom in lens design.
[0005]
In view of the above problems, an object of the present invention is to devise the arrangement of the variable aperture blades and to reduce the distance between the lenses and members sandwiching the variable aperture blades, and a lens with a variable aperture mechanism for a camera. To provide a mirror frame.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, the lens frame with a variable aperture mechanism of the camera of the present invention is provided in the photographic lens optical system and the photographic lens optical system, and is opened so as to restrict the passing light flux of the exposure light. A variable aperture blade having a variable aperture, and a lens that constitutes a part of the photographing optical system, is disposed adjacent to the aperture blade, and at least a surface facing the aperture blade is a convex surface, and The position of the operating surface of the diaphragm blade in the optical axis direction is arranged at a position that is closer to the lens surface than the top of the convex surface of the lens.
[0007]
In the lens barrel with a variable aperture mechanism of the camera of the present invention, the photographic lens optical system and the photographic lens optical system are provided in the photographic lens optical system, and the aperture diameter is variable so as to regulate the passing light flux of the exposure light. A diaphragm blade, a lens that constitutes a part of the photographing optical system, is disposed adjacent to the diaphragm blade, and at least a surface facing the diaphragm blade is a convex surface, and the lens is moved back and forth in the optical axis direction. A position of the operating surface of the diaphragm blade in the optical axis direction when the lens is closest to the diaphragm blade by the lens driving mechanism than the top of the convex surface of the lens. It is arrange | positioned in the position which entered the surface side.
[0008]
Further, in the lens frame with a variable aperture mechanism of the camera according to the present invention, the photographic lens optical system and the variably variable aperture diameter provided in the photographic lens optical system are capable of changing the aperture diameter so as to restrict the passing light flux of the exposure light. A diaphragm blade, a diaphragm blade opening / closing mechanism that opens and closes the diaphragm blade, and a part of the photographing optical system, is disposed adjacent to the diaphragm blade, and at least a surface facing the diaphragm blade is a convex surface A lens and a lens driving mechanism that moves the lens back and forth in the optical axis direction, and the position of the operating surface of the diaphragm blade in the optical axis direction is closest to the diaphragm blade by the lens driving mechanism. Sometimes, the lens is disposed at a position that is closer to the lens surface than the top of the convex surface of the lens, and the aperture blade is in a substantially open state of the aperture diameter, so that the lens is connected to the lens driving mechanism. Ri when moving in a direction away from the diaphragm blades, characterized in that it is driven in a direction to reduce the opening diameter by the diaphragm blade driving mechanism.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the illustrated examples.
FIG. 1 is an exploded perspective view showing a main part of a lens barrel with a variable aperture mechanism of a camera showing a first embodiment of the present invention. FIGS. 2 and 3 show the embodiment of the present invention. FIG. 2 is a cross-sectional view of the main part of the lens barrel with a variable aperture mechanism of the camera shown, in which FIG. 2 shows a state where the apertures of the variable aperture blades 4A and 4B are the smallest, and FIG. The most open state is shown.
[0010]
The lens barrel 1 is a cylindrical member, and has a front lens 5 fixedly attached to the tip thereof, and a shutter holding member 2 is fixed to the rear of the front lens. A rear group frame member (not shown) having a rear lens (not shown) fixed to a frame member (not shown) is disposed behind the shutter holding member 2 and is coaxial with the lens frame 1. It is configured to be movable, and the focal length can be changed by changing the distance between the front lens 5 and the rear lens. As described above, the lens frame of the camera is composed of the first group lens system consisting of the front lens 5 and the second group lens system (not shown), and the focal length is changed by changing the distance between the two lens groups. It constitutes a possible zoom lens.
[0011]
A fixed opening 2e is disposed at the center of the optical axis of the shutter holding member 2, and is sized so that the maximum luminous flux can pass through the entire focal length from the wide-angle range to the telephoto range. The shutter holding member 2 is integrally fixed with shutter blade support shafts 2a and 2b and diaphragm blade support shafts 2c and 2d. The shutter blade support shafts 2a and 2b are rotatably supported by the shutter blades 3A and 3B, which are also used as aperture blades, respectively, so that the shafts 3a and 3b can be rotated. The exposure is controlled by combining the opening diameter and the opening / closing speed. An aperture / shutter mechanism is provided. Apart from this shutter, the maximum aperture diameter is regulated by changing the maximum beam diameter according to the change in the focal length of the taking lens, so that the aperture blade support shafts 2c and 2d are fitted with holes 4a and 4b, respectively, so as to be rotatable. A diaphragm blade mechanism having variable diaphragm blades 4A and 4B that are pivotally supported is provided.
[0012]
In general, the diameter of a light beam that passes through varies depending on the focal length. Therefore, when the shutter blades 3A and 3B are fully opened, it is necessary to set and limit the maximum aperture diameter according to the focal length by the variable diaphragm blades 4A and 4B separately from the fixed opening 2e of the shutter holding member 2. For this purpose, the variable aperture blades 4A and 4B are provided.
The shutter blades 3A and 3B drive drive pins (not shown) engaged with the cam long holes 3c and 3d provided in the shutter blades 3A and 3B by a shutter opening / closing mechanism (not shown) that is linked to the photographing exposure operation. Opened and closed. The variable aperture blades 4A and 4B are operated by driving drive pins (not shown) engaged with the cam long holes 4c and 4d in conjunction with the variable focal length mechanism.
[0013]
The shutter opening / closing mechanism is controlled based on an exposure condition that is automatically determined based on a measurement value of a photometry unit that measures the brightness of a subject provided in the camera, or an exposure condition that is set by a manual operation.
The rear surface side of the front lens 5 is a convex lens having a convex surface protruding toward the shutter holding member. And in this Embodiment, when the amount of laps is set to A so that the operation plane of variable diaphragm blades 4A and 4B may wrap in the optical axis direction position with respect to the top of the rear surface of front lens 5, The variable aperture blades 4A and 4B are arranged so that A ≧ 0. The minimum apertures of the variable aperture blades 4A and 4B are regulated so as not to contact the surface of the lens 5.
[0014]
The operation of the lens barrel with the variable aperture mechanism of the camera according to the present embodiment will be briefly described.
By the focal length setting operation, the first lens group including the front lens 5 is provided, and the focus is changed by changing the distance between the lens frame 1 constituting the first group frame and the lens frame constituting the second lens group (not shown). Change the distance between wide angle and telephoto.
[0015]
When the set focal length is in the wide-angle region, the maximum luminous flux passing through the diaphragm blades is generally narrower than that in the telephoto region, so the variable diaphragm blades 4A and 4B are set to the narrowed positions as shown in FIG. When the focal length is in the telephoto area, the maximum luminous flux passing through the diaphragm blades is thicker than in the wide-angle region, so the variable diaphragm blades 4A and 4B are set to positions where the diaphragm is further opened as shown in FIG. In this way, the maximum aperture that can pass is regulated and controlled by interlocking the variable aperture blades 4A and 4B in accordance with the focal length.
[0016]
Then, the maximum beam diameter by the variable aperture blades 4A and 4B is controlled according to setting to a predetermined focal length, and then the shutter is driven by the shooting exposure start operation, and the shutter blades 3A and 3B are opened and closed, and the subject By setting the exposure aperture diameter and aperture time based on the exposure condition determined according to the brightness of the image, the exposure amount passing through the photographing lens is controlled.
[0017]
According to such an embodiment, by arranging the variable diaphragm blades in the optical axis direction from the top of the surface thereof in a range not hitting the convex lens surface with respect to the conventional diaphragm blade arrangement, The distance L in the optical axis direction from the top of the lens surface to the shutter holding member and other lenses can be made shorter than before, and the lens barrel and the camera incorporating it can be miniaturized.
[0018]
In addition, when there is a rear lens behind the shutter holding member, it is possible to shorten the distance between the lens groups with the front lens 5, so that the degree of freedom in lens optical design can be increased. As a result, it is possible to reduce the size of the lens barrel and obtain a camera having a lens with higher performance.
Further, in the case of a general two-group zoom lens, when changing the focal length from the wide-angle side to the telephoto side, the entire lens is moved forward in terms of optics, and the front lens 5 and the rear lens with the shutter mechanism interposed therebetween. Since the interval is narrowed, according to the present embodiment, it is possible to perform an optical design in which the focal length is extended to the telephoto side by the space in the optical axis direction that has been occupied by the variable aperture blades in the past.
[0019]
In the present embodiment, the aperture diameter of the variable aperture blade is automatically controlled in conjunction with zooming. However, in addition to the zooming operation, the aperture diameter of the aperture blade is varied in conjunction with a specific shooting mode switching operation or the like. It can also be applied to such cases.
Further, the present invention can also be applied to a case where the variable aperture blades that are varied according to the focal length are provided at appropriate positions in the lens barrel or the camera body as a so-called flare aperture that prevents harmful light from reaching the film surface.
[0020]
Next, a second embodiment of the present invention will be described with reference to the drawings.
4, 5 and 6 are cross-sectional views of the main part of a lens barrel with a variable aperture mechanism of a camera showing a second embodiment of the present invention. FIG. 4 shows a state in which the aperture of the aperture blade is wide open in a shooting preparation state, and FIG. 5 shows a state in which the aperture of the aperture blade is the smallest in the required range during shooting. FIG. 6 shows a retracted state in which the lens is retracted from the state shown in FIG. 4 so that the photographing lens prohibits photographing, and the aperture blade has a larger aperture than in the state shown in FIG. 5 so as not to interfere with the lens surface. It shows the state.
[0021]
The lens frame 21 has a shutter holding member 22 fixed thereto. A lens holding frame 26 to which the front lens 25 is fixed is fitted to the front side of the shutter holding member 22 so as to be slidable in the optical axis direction with respect to the lens frame 21. Here, the lens holding frame 26 is prevented from moving in the rotational direction because the hole 26a is engaged with the guide shaft 27 erected on the lens barrel 21 in the optical axis direction. The front lens 25 is moved in a straight line in the optical axis direction to move the focus of the front lens 25 from the state of FIG. 4 to the state of FIG. 5 with respect to the subject at the time of shooting, and the front lens 25 from the state of FIG. 4 to the state of FIG. Can be stored and moved to the retracted state.
[0022]
A rear group frame member having a rear lens (not shown) fixed to a frame member (not shown) is disposed on the rear side of the shutter holding member 22 and is configured to be movable coaxially with the lens frame 21. The focal length can be changed by changing the distance between the front lens 25 and the rear lens. As described above, the lens frame of the camera is a first group lens system composed of the front lens 25 and a second group lens system (not shown), and the focal length can be varied by varying the distance between both group lenses. The same zoom lens is configured as in the first embodiment.
[0023]
Shutter blade support shafts 22a and 22b and diaphragm blade support shafts 22c and 22d are integrally fixed to the shutter holding member 22. The shutter holding member 22 is closed after the shutter blades 23A and 23B are pivotally supported by the shutter blade support shafts 22a and 22b through the holes 23a and 23b, respectively, and always reach the fully opened opening diameter. The shutter mechanism controls the open / close waveform and controls the exposure according to the open / close speed.
[0024]
Further, the shutter holding member 22 is provided in front of the shutter mechanism in front of the shutter mechanism to change the aperture stop of the photographic lens optical system to set the aperture aperture diameter. Therefore, the aperture support shafts 22c and 22d have holes 24a and 22a, respectively. An aperture blade mechanism having variable aperture blades 24A and 24B that are pivotally supported by inserting 24b is disposed.
The shutter blades 23A and 23B are opened and closed by driving a drive pin (not shown) engaged with the cam long holes 23c and 23d in conjunction with a shutter release operation of the camera by a shutter opening / closing mechanism (not shown). . The aperture blades 24A and 24B are configured such that a drive pin (not shown) engaged with the cam long holes 24c and 24d is driven by an aperture blade opening / closing mechanism (not shown) so that the opening diameter can be changed. The exposure amount at the time of photographing is controlled by changing the combination of the aperture diameter of the aperture blade mechanism and the opening / closing time of the shutter mechanism according to the brightness of the subject.
[0025]
As shown in the figure, the front lens 25 is a convex lens having a convex surface whose rear surface side protrudes toward the shutter holding member.
In the second embodiment, in the retracted state shown in FIG. 6 and the photographing preparation state shown in FIG. The aperture blades 24A and 24B are arranged so that A ≧ 0 when the wrap amount is A as shown in the drawing so that the lap is performed at the axial position.
[0026]
FIG. 4 shows a preparatory position state before the front lens 25 is extended from the retracted position and focused, so that the aperture blades 24A and 24B have a considerably large opening diameter so as not to interfere with the front lens 25. Running away. FIG. 5 shows a state in which the front lens 25 is focused on the subject at a close distance at the extended position in the focusing movement range, and the front lens 25 is extended to a position where it does not overlap with the operation plane of the aperture blades 24A and 24B. Therefore, the aperture diameters of the aperture blades 24A and 24B can be changed to any size. FIG. 6 shows a state where the front lens 25 is in a retracted position further retracted from the state shown in FIG. 4, and the apex of the convex surface of the front lens 25 is closer to the shutter blades 23A and 23B. At this time, the diaphragm blades 24A and 24B further operate in the opening direction so as not to interfere with the convex surface.
[0027]
Thus, the minimum apertures of the variable aperture blades 24A and 24B are regulated so as not to come into contact with the surface of the front lens 25 according to the extension position of the front lens in the optical axis direction.
The operation of the lens barrel having the variable aperture mechanism of the second embodiment will be briefly described.
[0028]
In FIG. 4, when a camera release operation (not shown) is performed, the lens holding frame 26 is driven in the forward direction away from the variable aperture blades 24A and 24B by the lens driving mechanism. The lens driving mechanism is controlled by a CPU (Central Processing Unit) (not shown), and the CPU holds the lens holding frame 26 at a target stop position. When the lens holding frame 26 stops, the diaphragm blades 24A and 24B are then driven in the closing direction by the diaphragm blade driving mechanism. The diaphragm blade driving mechanism is controlled by the CPU, and the CPU controls and stops the diaphragm blades 24A and 24B at a target stop position.
[0029]
As shown in FIG. 5, when the diaphragm blades 24A and 24B are stopped, the shutter blades 23A and 23B are opened and closed by the shutter opening and closing mechanism, and the aperture blades 24A and 24B of the photographing lens are used as the exposure opening time according to the brightness of the subject. The exposure amount passing through the opening diameter of 24B is controlled.
In the second embodiment, in the retracted state, as in the first embodiment, the diaphragm blades are arranged on the lens side from the top of the lens surface, so from the top of the lens surface to the shutter holding member and other lenses. Since the distance L can be made shorter than before, the lens barrel can be downsized.
[0030]
Further, in the second embodiment, the aperture blades 24A and 24B are normally set in an open state in which the aperture diameter is increased so as to avoid interference with the front lens 25. Since the aperture diameter is driven to change after being separated from the aperture blades 24A and 24B in the optical axis direction, the aperture diameters of the aperture blades 24A and 24B can be freely reduced without being restricted by interference with the front lens 25. It is.
[0031]
Further, when the lens barrel is folded and moved in the optical axis direction so as to shorten the distance between the lenses so as to be in the retracted state, as shown in FIG. 5, the apertures of the aperture blades 24A and 24B are compared with the photographing preparation state of FIG. It can be further widened to increase the amount of lap between the top of the lens surface and the aperture blades 24A and 24B, so that it can be miniaturized for convenience in carrying.
[Appendix]
According to the above-described embodiment of the present invention as described in detail above, the following configuration can be obtained.
[0032]
(1) A variable aperture blade that can change the aperture diameter so as to restrict the light to be exposed and does not become fully closed;
A lens that is arranged adjacent to the diaphragm blades, and at least a surface facing the diaphragm blades is a convex surface;
Have
A variable aperture mechanism for a camera, wherein the position of the aperture blade in the optical axis direction is the same as the top of the convex surface of the lens, or is located at the position closer to the lens surface than the top With lens barrel.
[0033]
(2) a shutter blade that performs exposure by passing light by opening and closing; and
A variable aperture blade that can change the aperture diameter so as to regulate the diameter of the passing light beam to be exposed and does not become fully closed,
A lens that is arranged adjacent to the diaphragm blades, and at least a surface facing the diaphragm blades is a convex surface;
Have
A variable aperture mechanism for a camera, wherein the position of the aperture blade in the optical axis direction is the same as the top of the convex surface of the lens, or is located at the position closer to the lens surface than the top With lens barrel.
[0034]
(3) a variable aperture blade whose aperture diameter can be changed so as to regulate light to be exposed, and which is not fully closed;
A lens that is arranged adjacent to the diaphragm blades, and at least a surface facing the diaphragm blades is a convex surface;
A lens driving mechanism for moving the lens back and forth in the optical axis direction;
Have
The position of the diaphragm blade in the optical axis direction is the same as the top of the convex surface of the lens when the lens is closest to the diaphragm blade by the lens driving mechanism, or enters the lens surface side from the top of the lens. A lens barrel with a variable aperture mechanism for a camera, characterized in that the lens is arranged at an open position.
[0035]
(4) a variable aperture blade whose aperture diameter can be changed so as to regulate the light to be exposed and which does not become a fully closed state;
A diaphragm blade opening and closing mechanism for opening and closing the diaphragm blade;
A lens that is arranged adjacent to the diaphragm blades, and at least a surface facing the diaphragm blades is a convex surface;
A lens driving mechanism for moving the lens back and forth in the optical axis direction;
Have
The position of the diaphragm blade in the optical axis direction is the same as the top of the convex surface of the lens when the lens is closest to the diaphragm blade by the lens driving mechanism, or enters the lens surface side from the top of the lens. The aperture blade is disposed at a position where the aperture diameter is in an open state and the lens is moved away from the aperture blade by the lens drive mechanism, and then the aperture diameter is adjusted by the aperture blade drive mechanism. A lens barrel with a variable aperture mechanism for a camera, wherein the lens barrel is driven in a direction to reduce the size.
[0036]
(5) In supplementary note 3, a diaphragm aperture blade opening / closing mechanism for further opening and closing the aperture blade;
Zoom optics,
Focal length changing means for changing the focal length of the zoom optical system;
Have
The lens frame with a variable aperture mechanism of a camera, wherein the aperture blade drive mechanism operates in conjunction with the focal length changing means.
[0037]
(6) In Appendix 4,
The camera has a photometric means for measuring the brightness of the subject,
The lens frame with a variable aperture mechanism of a camera, wherein the aperture blade drive mechanism is controlled based on a photometric value measured by the photometric means.
(7) In Appendix 4,
The camera has exposure condition setting means for changing the exposure condition,
The lens barrel with a variable aperture mechanism of a camera, wherein the aperture blade driving mechanism is controlled based on the condition set by the exposure condition setting means.
[0038]
(8) A variable aperture blade whose aperture diameter can be changed so as to regulate the light to be exposed, and which is not fully closed;
A diaphragm blade opening and closing mechanism for opening and closing the diaphragm blade;
A lens optical system with a variable focal length;
Focal length changing means for changing the focal length of the lens optical system with variable focal length;
A lens that constitutes the lens optical system, is disposed adjacent to the aperture blade, and at least a surface facing the aperture blade is a convex surface;
A lens driving mechanism that moves the lens back and forth in the optical axis direction in conjunction with the focal length changing means;
A diaphragm interlocking mechanism that operates the diaphragm blade driving mechanism in conjunction with the focal length changing means;
Have
The position of the diaphragm blade in the optical axis direction is the same as the top of the convex surface of the lens when the lens is closest to the diaphragm blade by the lens driving mechanism, or enters the lens surface side from the top of the lens. The diaphragm blades are arranged at the positions of the aperture blades, and the aperture blades are moved to a direction in which they are moved away from the diaphragm blades by the lens driving mechanism, with the aperture diameter of the aperture interlocking mechanism being substantially open. A lens barrel with a variable aperture mechanism for a camera, wherein the lens barrel is driven in a direction to reduce the aperture diameter by a driving mechanism.
[0039]
【The invention's effect】
As described above, according to the lens barrel having the variable aperture mechanism according to the present invention, the variable aperture blade is disposed in a position not entering the convex lens surface and entering the optical axis direction from the surface top. The distance in the optical axis direction from the top of the lens surface to the shutter holding member and other lenses can be shortened, and the lens barrel can be reduced in size.
[0040]
In addition, since it is possible to shorten the distance between the lens groups with the variable aperture blade interposed therebetween, it is possible to increase the degree of freedom in lens optical design, and it is possible to obtain a lens barrel with higher performance.
Furthermore, when the lens is moved in the optical axis direction during non-shooting and during shooting, the lens is separated in the optical axis direction from the variable aperture blade that is wrapped in the optical axis direction with this lens. By driving the aperture diameter to be changed later, it is possible to freely reduce the aperture diameter of the variable aperture blade without being restricted by interference with the lens.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view showing a main part of a lens barrel with a variable aperture mechanism of a camera according to a first embodiment of the present invention, as viewed obliquely from the front.
FIG. 2 is a cross-sectional view of a main part of a lens barrel with a variable aperture mechanism of a camera showing a first embodiment of the present invention, showing a state where the apertures of variable aperture blades 4A and 4B are the smallest.
FIG. 3 is a cross-sectional view of the main part of the lens barrel with a variable aperture mechanism of the camera showing the first embodiment of the present invention, showing a state in which the apertures of the variable aperture blades 4A and 4B are opened most.
FIG. 4 is a cross-sectional view of an essential part of a lens barrel with a variable aperture mechanism of a camera showing a second embodiment of the present invention, in a state where it is in a shooting preparation state so as not to interfere with the lens surface. It shows a state where the aperture is wide open.
FIG. 5 is a cross-sectional view of the main part of a lens barrel with a variable aperture mechanism of a camera showing a second embodiment of the present invention, in which the aperture blade aperture is the smallest in the required range at the time of shooting; Indicates.
6 is a cross-sectional view of an essential part of a lens barrel with a variable aperture mechanism of a camera showing a second embodiment of the present invention, from the state shown in FIG. 4 so that the photographing lens prohibits photographing. FIG. 4 shows a state in which the aperture is larger than the state shown in FIG. 4 so that the variable aperture blade is in the retracted state and is not interfered with the lens surface.
FIG. 7 is a cross-sectional view of an essential part showing a lens barrel with a variable aperture mechanism of a conventional camera.
[Explanation of symbols]
1,21 Lens frame 2,22 Shutter holding members 3A, 3B, 23A, 23B Shutter blades 4A, 4B, 24A, 24B Variable aperture blades 5, 25 Front lens 26 Lens holding frame 27 Guide shaft

Claims (3)

A taking lens optical system;
A variable aperture blade provided in the photographic lens optical system, the aperture diameter of which can be changed so as to regulate a passing light flux of light to be exposed;
A lens that constitutes a part of the photographing optical system, is disposed adjacent to the diaphragm blade, and at least a surface facing the diaphragm blade is a convex surface;
Have
A lens barrel with a variable aperture mechanism for a camera, wherein the position of the operating surface of the aperture blade in the optical axis direction is arranged at a position that is closer to the lens surface than the top of the convex surface of the lens . A taking lens optical system;
A variable aperture blade provided in the photographic lens optical system, the aperture diameter of which can be changed so as to regulate a passing light flux of light to be exposed;
A lens that constitutes a part of the photographing optical system, is disposed adjacent to the diaphragm blade, and at least a surface facing the diaphragm blade is a convex surface;
A lens driving mechanism for moving the lens back and forth in the optical axis direction;
Have
The position of the operating surface of the diaphragm blade in the optical axis direction is arranged at a position that enters the lens surface side from the top of the convex surface of the lens when the lens is closest to the diaphragm blade by the lens driving mechanism. A lens barrel with a variable aperture mechanism for a camera. A taking lens optical system;
A variable aperture blade provided in the photographic lens optical system, the aperture diameter of which can be changed so as to regulate a passing light flux of light to be exposed;
A diaphragm blade opening and closing mechanism for opening and closing the diaphragm blade;
A lens that constitutes a part of the photographing optical system, is disposed adjacent to the diaphragm blade, and at least a surface facing the diaphragm blade is a convex surface;
A lens driving mechanism for moving the lens back and forth in the optical axis direction;
Have
The position of the operating surface of the diaphragm blade in the optical axis direction is arranged at a position that is closer to the lens surface than the top of the convex surface of the lens when the lens is closest to the diaphragm blade by the lens driving mechanism. The aperture blade is in a substantially open state of the aperture diameter, and when the lens is moved away from the aperture blade by the lens driving mechanism, the aperture blade is driven in a direction to reduce the aperture diameter. A lens barrel with a variable aperture mechanism for a camera.

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