JP2001075144A - Diaphragm device, lens device and camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the cost and reduce the size without using a cam member. SOLUTION: In this diaphragm device, 1st and 2nd diaphragm blades 1 and 2 are arranged by plural sets around an optical axis, and a part different from the attaching part of the 1st diaphragm blade to a diaphragm board member 5 in each set and a part different from the attaching part of the 2nd diaphragm blade to rotating members 6 and 10 are coupled to relatively turn, and a plurality of the rotating members 6 and 10 are arranged in an optical axis direction and also coupled to integrally rotate, then the plural sets of diaphragm blades are divided and arranged by the same number between the member 5 and the member 10 adjacent to the member 5 and between the members 6 and 10 adjacent to each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diaphragm device used for a lens device for TV and still photography.

[0002]

2. Description of the Related Art FIGS. 10 to 12 show the structure of a diaphragm device used in a conventional lens device. As shown in these figures, this diaphragm device is configured to have a plurality of diaphragm blades 50, and a rotary shaft 51 is provided on one side of each diaphragm blade 50, and a pin 52 is provided on the other side. ing.

The number of rotating shafts 51 of each of the diaphragm blades 50 is equal to the number of blades in a portion around the opening 54 facing the optical axis direction (hereinafter referred to as a base plate portion) of a cylindrical diaphragm blade container 53 with a bottom. The shaft holes 55 are fitted respectively. Thereby, the plurality of aperture blades 50 are provided in the container 53 by the rotation shaft 5.
1 is rotatably accommodated.

In the diaphragm blade container 54, a cam member 56 having an opening 57 is rotatable about the optical axis with respect to the diaphragm blade container 54 with the diaphragm blade 50 interposed between the diaphragm member and the main plate. Accommodated as possible. The pins 52 of the aperture blades 50 are fitted into the cam grooves 58 formed on the cam member 56 in the same number as the number of blades.

In the aperture device constructed as described above, when the cam member 56 is rotated about the optical axis with respect to the aperture blade container 53, each pin 52 moves along each cam groove 58. The aperture blades 50 rotate about the respective rotation shafts 51, and the effective area of the aperture opening formed inside them changes due to the overlap of the aperture blades 50. Thus, the amount of light passing through the aperture device can be adjusted.

However, in the above-mentioned conventional diaphragm device, the outer diameter of the diaphragm blade 50 is determined so that light does not leak from a portion other than the effective diaphragm opening when the diaphragm is stopped down. It could not be smaller.

If the number of aperture blades is increased, the aperture blades can be downsized even with the same configuration of the above-described aperture device. In this case, however, if the number of cam grooves 58 to be machined in the cam member 56 increases, Since adjacent cam grooves interfere with each other, it becomes difficult to process the cam grooves. For this reason, it is difficult to reduce the size of the aperture device and, consequently, the size of the entire lens device.

On the other hand, Japanese Patent No. 2607672 proposes the following diaphragm device in order to achieve a reduction in the size of the diaphragm device.

That is, in the diaphragm device according to the above patent,
As shown in FIGS. 13 to 15, a first diaphragm blade group 61 including a plurality of diaphragm blades for determining an effective diaphragm aperture and a second diaphragm blade group 62 including a plurality of second diaphragm blades are arranged along an optical axis. Cam members 6 arranged in the front and rear directions to correspond to each aperture blade group
3. Rotate 64. Then, an effective aperture opening is determined by the first aperture blade group, and the second aperture blade group is operated to cover a non-overlapping portion other than the effective aperture aperture of the first aperture blade group. As a result, the outer diameter of the diaphragm blade is reduced, and the size of the diaphragm device is reduced.

[0010]

However, in the aperture device according to the above-mentioned patent, the same number of cam members as the number of aperture blade groups are used to operate the plurality of aperture blade groups. There is a problem that becomes high.

[0011]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, according to the present invention, an aperture member is disposed in parallel with the aperture member in the optical axis direction. A rotating member rotatable around the first, a first diaphragm blade rotatably attached to the diaphragm ground member in a plane orthogonal to the optical axis,
And a second diaphragm blade rotatably mounted on the rotating member in a plane orthogonal to the optical axis. A plurality of first and second diaphragm blades are arranged around the optical axis. In a diaphragm device in which a portion different from a portion where the first diaphragm blade is attached to the diaphragm base member and a portion different from a portion where the second diaphragm blade is attached to the rotating member are relatively rotatably connected, A plurality of diaphragm members are arranged in the direction of the optical axis, and the plurality of rotating members are connected so as to be integrally rotatable. The plurality of sets of diaphragm blades are arranged between the diaphragm member and the rotating member adjacent to the diaphragm member in the optical axis direction and with each other. The same number of sets are divided and arranged between rotating members adjacent in the axial direction.

In the aperture device constructed as described above, when the plurality of rotating members are integrally rotated to rotate the second aperture blade in synchronization with the rotating members, the rotation of the second aperture blade causes the rotation of the second aperture blade. The first diaphragm blade connected to this rotates around a portion attached to the diaphragm member. When a plurality of sets of the first and second aperture blades connected as described above are arranged around the optical axis, and the first aperture blade is used as an aperture blade for forming an effective aperture opening, each first aperture blade is used. Are formed inside these aperture openings, the effective area of which can be adjusted. Moreover, with the second diaphragm blade,
It is possible to cover openings other than the effective aperture opening formed between the first aperture blades, and it is possible to prevent light from leaking from other than the effective aperture opening.

Further, according to the drawing device of the present invention, since the cam groove is not used unlike the related art, there is no need to machine the cam groove, and the cost can be reduced as compared with the related art. Also,
If the outer diameter of the aperture device is reduced, the problem that adjacent cam grooves interfere with each other is eliminated, so that the number of aperture blades can be increased as compared with the conventional case, and further downsizing can be realized.

Further, when the number of sets is n and the number of divisions of each set is m, the plurality of sets of diaphragm blades are spaced (360 / n) ° around the optical axis when viewed in the optical axis direction. And the diaphragm blades arranged between the same members by the same number of sets are divided around the optical axis (m × 36).
By disposing at intervals of 0 / n) °, for example, interference between a portion of the second diaphragm member attached to the rotating member and another set of first diaphragm blades disposed between the same member as the second diaphragm blade is performed. The rotation of the rotation member by approximately (m × 360 / n) ° is allowed without causing interference between the constituent members. Therefore, it is possible to increase the number of sets of diaphragm blades and reduce the size of the diaphragm device, and to set the rotational operation angle of the rotating member from the opening of the diaphragm to the minimum diaphragm in a range where good operability can be obtained. It becomes possible.

[0015] At least one of the plurality of rotating members is provided.
By using a member having a smaller thickness in the optical axis direction than the other rotating members as one of the rotating members, it is possible to suppress an increase in the thickness of the diaphragm device in the optical axis direction due to an increase in the number of rotating members.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 to 3 show the construction of a diaphragm device employing a diaphragm blade drive system which is a prerequisite technology of the diaphragm device according to the present invention. FIG. 1 shows the overall configuration of the aperture device, and FIGS. 2 and 3 show only one set of the first aperture blade and the second aperture blade. FIG. 2 shows a state in which the aperture is open, and FIG. 3 shows a state in which the aperture is being stopped.

In these figures, reference numeral 1 denotes a first thin plate-like member formed in a substantially arc shape whose diameter on the optical axis side (hereinafter referred to as the inside) in the optical axis radial direction is larger than the effective opening diameter of the optical lens system. It is an aperture blade.

Reference numeral 2 denotes a thin plate-shaped second diaphragm blade having a length shorter than the length of the first diaphragm blade 1 and formed in a substantially arc shape.

Reference numeral 3 denotes a pin member protruding at one end on one side of the first diaphragm blade 1, and 4 denotes a second diaphragm blade 2.
This is a pin member protrudingly formed at one end of the upper surface.

Reference numeral 5 is a cylindrical diaphragm blade container (diaphragm base member) having a bottom, and a circular hole having a diameter larger than the effective opening diameter is provided in a base plate portion corresponding to the bottom surface so as not to block light rays when the diaphragm is opened. 5b are formed.

A plurality of small circular holes 5a whose central axis is parallel to the optical axis are radially provided around the circular hole 5b in the ground plane portion. Each small hole 5
The pin member 3 of each first aperture blade 1 is rotatably fitted to a. As a result, the first diaphragm blade 1 becomes the diaphragm blade container 5
Is supported rotatably in a direction (within a plane orthogonal to the optical axis) that advances and retreats with respect to the stop optical path formed by the circular hole 5b.

Reference numeral 6 denotes a ring-shaped disk member (rotating member) having a circular hole 6b having a diameter larger than the effective opening diameter (in this embodiment, larger than the circular hole 5b of the diaphragm blade container 5) in the center. Is provided. The movement of the disk member 6 is restricted in the optical axis direction with respect to the diaphragm blade container 5, and the disk member 6 is supported so as to be rotatable about the optical axis.

The disk member 6 is provided with a plurality of small circular holes 6a whose central axes are parallel to the optical axis, radially about the optical axis. The pin members 4 of the second aperture blades 2 are rotatably fitted in the small circular holes 6a. This allows
The second diaphragm blade 2 is supported by the disk portion 6 so as to be rotatable in a direction (in a plane orthogonal to the optical axis) that advances and retreats with respect to the diaphragm optical path.

The intermediate portion of the first diaphragm blade 1 and the other end of the second diaphragm blade 2 are relatively rotatably connected in a plane orthogonal to the optical axis by loose caulking or the like at a connecting portion 1a. I have. A plurality of sets of the first diaphragm blades 1 and the second diaphragm blades 2 connected to each other are configured so that the angular relationship is equally divided in the circumferential direction around the optical axis.

Reference numeral 7 shown in FIG. 1 denotes a housing of a lens device on which the above-described aperture device is mounted. The aperture blade container 5 is integrally fixed to the housing 7. Reference numeral 8 denotes an aperture operation ring, which is restricted from moving in the optical axis direction with respect to the housing 7 and is rotatably supported about the optical axis. Also, the aperture operation ring 8
On the upper side, a scale 8a indicating the F-number of the aperture is displayed, and the F-number of the aperture corresponding to the rotation angle of 8 can be confirmed by the positional relationship with the index line 7a provided on the housing 7. ing.

Reference numeral 9 denotes a pin member, which passes through an elongated hole 7b provided in the housing 7, and
Are connected so that they can be rotated synchronously.

In the aperture device and the lens device configured as described above, when the operator rotates the aperture operation ring 8 manually or electrically by a motor or the like to change the light amount, the aperture operation ring 8 is attached to the housing 7. On the other hand, it rotates around the optical axis.

When the aperture operation ring 8 rotates, the disk member 6 connected to the operation ring 8 by the pin member 9 also rotates in synchronization with the rotation of the operation ring 8.

When the disk member 6 rotates, the pin member 4 fitted in the small circular hole 6a moves along a circular orbit centered on the optical axis, and accordingly, the second diaphragm blade 2 moves the optical path. Move forward and backward.

Further, the second diaphragm blade 2 is connected to the first diaphragm blade 1.
When the second diaphragm blade 2 moves forward and backward, the first diaphragm blade 1 moves forward and backward with respect to the diaphragm optical path around the pin member 3 accordingly.

When the first diaphragm blades 1 enter the diaphragm optical path in this way, the first diaphragm blade groups overlap each other, and an effective diaphragm aperture is formed inside these. Further, of the openings formed between the first diaphragm blade groups, portions other than the effective diaphragm openings (the openings formed outside the first diaphragm blades 1) are covered by the second diaphragm blade group. As a result, light does not leak from portions other than the effective aperture.

Here, the relationship between the rotation angle of the disk member 6 and the rotation angle of the first diaphragm blade 1 is uniquely determined by geometric conditions, and the effective area of the diaphragm aperture is determined by the first diaphragm blade. 1
Is determined by the rotation angle of. For this reason, by changing the rotation angle of the diaphragm operation ring 8 for rotating the disk member 6, the effective area of the diaphragm opening changes, and the effect of the diaphragm can be obtained.

According to the above-described diaphragm device, the same diaphragm effect as that of the conventional diaphragm device can be obtained. However, in the present diaphragm device, a cam member for operating the diaphragm blades 1 and 2 is not used. There is no need to machine a high-precision cam groove, and the cost can be reduced as compared with the conventional case. In addition, since the problem that adjacent cam grooves interfere with each other is eliminated, the number or the number of sets of diaphragm blades arranged on the circumference can be increased as compared with the conventional case, and further downsizing of the diaphragm device can be realized.

By the way, the first and second aperture blades 1, 2
In the case where n sets are arranged around the optical axis, as shown in FIG. 4, the first stop blade at a certain position is 1-A, and the second stop blade forming a pair with the first stop blade 1-A is 2 -A, an angle (360 / n) ° around the optical axis from the first diaphragm blade 1-A
1-B, the first diaphragm blade 1-B, and the first diaphragm blade 1-
When the second diaphragm blade forming a pair with B is 2-B, the second diaphragm blade 2-A is connected to the first diaphragm blade 1A in at least one place.
-B and the diaphragm blade container 5 are disposed so as to be sandwiched in the optical axis direction.

When the rotating member 6 is rotated in this state, the pin member 4 of the second diaphragm blade 2-A fitted in the small circular hole 6a moves along a circular orbit centered on the optical axis. When the pin member 4 of the second diaphragm blade 2-A moves to the vicinity of the pin member 3 of the first diaphragm blade 1-B, as shown in FIG. 5, the pin member 4 is moved to the first diaphragm blade 1-B. And cannot move any further.

Thus, in the aperture device having the above configuration, the rotation range of the rotating member 6, that is, the rotation range of the aperture operation ring 8 is changed from the aperture open position to the second aperture blade 2
The rotation angle is limited to a range where the -A pin member 4 does not collide with the end surface of the first diaphragm blade 1-B, and is smaller than (360 / n) °.

On the other hand, when the aperture of the photographing lens is manually operated, the operability is deteriorated if the rotation angle of the operation ring from opening the aperture to the minimum aperture is too small or too large.
It is considered that about 90 ° is good for operation.

However, according to the aperture device having the above-described configuration, when the rotation angle of the operation ring 8 is to be set to about 90 °, it is necessary to set n to 4 or less, and the first and second arrangements around the optical axis are required. The object of the present invention in which the number of sets of the second diaphragm blades 1 and 2 is increased to reduce the outer shape of the diaphragm device cannot be achieved.

(Embodiment) In order to solve the above-mentioned problem, an aperture device as shown in FIG. 6 is constructed as an embodiment of the present invention. In addition, in the figure, the same reference numerals are given to components common to those in FIGS.

In this embodiment, a circular hole 1 having a diameter equal to or larger than the effective opening diameter is provided at the center of the drawing device shown in FIGS.
0b, and a ring-shaped thin disk member 10 in which a plurality of small circular holes 10a whose central axes are parallel to the optical axis are radially formed around the optical axis is added.

In the present embodiment, the number n of all sets of the first and second diaphragm blades is a multiple of two. here,
“2” is a division number (m) when the same number of sets of n sets of diaphragm blades are divided and arranged between the diaphragm blade container 5 and the disk member 10 and between the disk members 10 and 6 as described below. )
It is.

In this embodiment, first, n / 2 sets of the first and second diaphragm blades 1 and 2 are arranged on the diaphragm blade container 5 at an angle of (2 × 360 / n) ° around the optical axis. The pin member 3 of the first angular aperture blade 1 is inserted into the small circular hole 5a of the aperture blade container 5.
Is fitted.

Next, the disk member 10 is positioned so that the n / 2 sets of the first and second diaphragm blades 1 and 2 are sandwiched between the disk member 10 and the main plate portion of the diaphragm blade container 5 in the optical axis direction. To place. At this time, the pin member 4 of each second diaphragm blade 2 is fitted into the small circular hole 10a of the disk member 10.

Further, the remaining n /
The two sets of first and second aperture blades 1 and 2 are angled (36) with the n / 2 sets of first and second aperture blades 1 and 2 arranged earlier.
0 / n) °, at an angle (2 × 360) around the optical axis.
/ N) °. At this time, the pin member 3 of each of the first diaphragm blades 1 arranged later is fitted into the small circular hole 5a of the diaphragm blade container 5.

Then, the disk member 6 is disposed thereon, and the pin member 4 of the second diaphragm blade 2 disposed later is connected to the disk member 6.
In the small circular hole 6a.

The movement of the disk member 6 in the optical axis direction with respect to the diaphragm blade container 5 is restricted, and the disk member 6 is supported so as to be rotatable about the optical axis. The disk member 6 is a disk member 1.
It is connected so as to rotate integrally with 0 around the optical axis.

In such a configuration, when the aperture operation ring 8 connected to the disk member 6 is rotated, the disk members 6, 10 rotate integrally about the optical axis. At this time,
The first and second diaphragm blades 1 and 2 of each set operate similarly to the diaphragm device having the configuration shown in FIGS. 1 to 3 when viewed in the optical axis direction, so that a similar diaphragm effect is obtained.

Here, as shown in FIG. 7, a pin member 4-A of a set of second diaphragm blades 2-A disposed between the diaphragm blade container 5 and the disk member 10 is viewed in the optical axis direction. Considering the case where the member moves from the set to the vicinity of the pin member 3-B of the first diaphragm blade 1-B of the set arranged at the angle (360 / n) °, the pin member 4-A is considered. Is a disk member 10
Of the angle (36).
0 / n) °, the first diaphragm blade 1-B of the set arranged between the disk members 6 and 10 has the pin member 4
-A does not interfere with the first diaphragm blade 1-B, and further sets the pair arranged at an angle (2 × 360 / n) ° advanced by an angle (360 / n) °, that is, the second diaphragm blade 2-A. Similarly to the set including the diaphragm blade container 5 and the disk member 10, the set can move within a range until the first diaphragm blade 1-C interferes with the set.

As described above, according to the present embodiment, the disk member 10 is added between the aperture blade container 5 and the disk member 6, and the space between the aperture blade container 5 and the disk member 10 By dividing and arranging the same number of sets of the first and second aperture blades 1 and 2 between the two disk members 6 and 10, the rotation range of the aperture operation ring 8 can be adjusted to the aperture device shown in FIGS. An aperture device with good operability can be obtained while reducing the cost by eliminating the need for a cam groove and reducing the size by increasing the number of aperture blade sets.

In this embodiment, the disk member 10 is
Although the case where only one sheet is added is shown, a plurality of disc members 10 are added and arranged in parallel between the diaphragm blade container 5 and the disc member 6, and the first and second diaphragm blades are interposed between these members. May be arranged by the same number.

In the present embodiment, a loose caulking is used for the connecting portion 1a between the first diaphragm blade 1 and the second diaphragm blade 2, and the connection between the first diaphragm blade 1 and the diaphragm blade container 5 and the second diaphragm The case where the pin members 3, 4 and the small circular holes 5a, 6a, 10a are fitted to connect the blades 2 to the disk members 6, 10 has been described, but a bearing member is used for these portions. Alternatively, other connection methods may be used.

FIG. 8 shows the overall configuration of a lens device equipped with the aperture device of this embodiment. As described above, by using the aperture device S miniaturized in the radial direction and the optical axis direction, the outer diameter of the housing 7 of the lens device L can be reduced, and a small and lightweight lens device can be realized. . Further, since the cost of the aperture device is reduced, the cost of a lens device equipped with the same can be reduced.

FIG. 9 shows a camera equipped with the lens device L. By mounting the small and lightweight lens device L as described above, it is possible to reduce the size, weight and cost of the entire camera system.

[0054]

As described above, according to the present invention,
Since a cam member provided with a cam groove is not used unlike the conventional drawing device, there is no need to process the cam groove, and the cost can be reduced as compared with the conventional drawing device. Also,
Reducing the outer diameter of the aperture device eliminates the problem of adjacent cam grooves interfering with each other.Therefore, the number of aperture blades and the number of sets arranged around the optical axis can be made larger than before, and further downsizing is realized. it can.

Further, when the number of sets is n and the number of divisions for each set is m, the plurality of sets of aperture blades are spaced (360 / n) ° around the optical axis when viewed in the optical axis direction. And the diaphragm blades arranged between the same members by the same number of sets are divided around the optical axis (m × 36).
0 / n) °, the rotation member can be rotated by approximately (m × 360 / n) ° without causing interference between the constituent members, so that the number of sets of aperture blades is larger than in the past. Thus, the rotation operation angle of the rotary member from the opening of the aperture to the minimum aperture can be set in a range in which good operability can be obtained while downsizing the aperture device.

Further, at least one of the plurality of rotating members
If a member having a smaller thickness in the optical axis direction than the other rotating members is used as one rotating member, an increase in the thickness of the diaphragm device in the optical axis direction due to an increase in the number of rotating members can also be suppressed.

[Brief description of the drawings]

FIG. 1 is a front view, a side cross-sectional view, and a plan view of a diaphragm device that is a base technology of the present invention.

FIG. 2 is an explanatory diagram of connection of first and second aperture blades in the aperture device (open state).

FIG. 3 is an explanatory diagram of connection of first and second aperture blades in the aperture device (in the middle of an aperture state).

FIG. 4 is a layout view of diaphragm blades in the diaphragm device.

FIG. 5 is a view for explaining interference between components in the diaphragm device.

FIG. 6 is a side sectional view of the diaphragm device according to the embodiment of the present invention.

FIG. 7 is a front view of the aperture device of the embodiment.

FIG. 8 is a side view of a lens device equipped with the diaphragm device of the embodiment.

FIG. 9 is a side view of a camera equipped with the lens device.

FIG. 10 is a side sectional view of a conventional diaphragm device.

FIG. 11 is a rear view of a conventional diaphragm device.

FIG. 12 is a front view of a conventional diaphragm device.

FIG. 13 is a side sectional view of a conventional diaphragm device.

FIG. 14 is a rear view of a conventional diaphragm device.

FIG. 15 is a front view of a conventional diaphragm device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st aperture blade 2 2nd aperture blade 3,4,9 Pin member 5 Aperture blade container 6,10 Disk member 7 Lens device housing 8 Operation ring

Claims (6)

[Claims] An aperture member which is disposed in parallel with the aperture member in the optical axis direction and is rotatable around the optical axis with respect to the aperture member; A first diaphragm blade rotatably mounted in the plane perpendicular to the axis, and a second diaphragm blade rotatably mounted in the plane perpendicular to the optical axis on the rotating member; First
And a plurality of sets of second diaphragm blades arranged around the optical axis, and a portion of each group different from a mounting portion of the first diaphragm blade to the diaphragm ground member, and mounting of the second diaphragm blade to the rotating member. In a diaphragm device in which a part different from the part is connected so as to be relatively rotatable, a plurality of the rotating members are arranged in the optical axis direction, and the plurality of rotating members are connected so as to be integrally rotatable. A diaphragm device, wherein the same number of sets are divided and arranged between the diaphragm base member and the rotary member adjacent thereto in the optical axis direction and between the rotary members adjacent to each other in the optical axis direction. 2. When the number of sets of the plurality of sets is n and the number of divisions of the same number of sets is m, the plurality of sets of aperture blades are arranged around the optical axis in the optical axis direction (360 / n). The aperture blades are arranged at an interval of ° and the aperture blades arranged between the same members by the same number of groups are arranged at intervals of (m × 360 / n) ° around the optical axis. The squeezing device as described. 3. An effective aperture opening is formed by the plurality of first aperture blades, and an opening other than the effective aperture opening formed between the first aperture blades by the plurality of second aperture blades is covered. The aperture device according to claim 1 or 2, wherein 4. At least one of the plurality of rotating members
4. The diaphragm device according to claim 1, wherein a member having a smaller thickness in the optical axis direction than the other rotating members is used as one of the rotating members. 5. A lens device comprising the diaphragm device according to claim 1. Description: 6. A camera comprising the lens device according to claim 5.