JP2001005042A - Adjustment mechanism for diaphragm opening/closing device at the time of assembling - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adjustment mechanism capable of performing adjustment in a shorter time because measurement and adjustment have only to be performed once, respectively, in terms of the adjustment of the diaphragm diameter of a diaphragm opening/closing device at the time of assembling by providing a means for changing the relative angle positions of a fixed ring and a supporting ring at the assembling and fixing time stepwise. SOLUTION: A 1st step part 11a having an inside diameter as long as the outside diameter of the supporting ring 12 and holding the ring 12 is formed on the inner periphery of the fixed ring 11. The ring 12 is nipped and held between the step part 11a of the ring 11 and a filter frame 14. One engaging projection engaged with the U-shaped groove of the ring 12 is formed on the inner periphery of the step part 11a of the ring 11. By engaging the engaging projection in any U-shaped groove, the angle position of the ring 12 to the ring 11 is decided. Thus, the adjustment of the diaphragm diameter of the diaphragm opening/closing device can be finely performed stepwise in a wide range, so that it is intelligible and easy and the working time is made shorter than that in the conventional manner.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adjustment mechanism for assembling an aperture opening / closing device for an interchangeable lens barrel for a single-lens reflex camera.

[0002]

2. Description of the Related Art Conventionally, the adjustment of the aperture diameter at the time of assembling an aperture opening / closing device is performed by measuring the deviation of the aperture diameter from a reference value with a measuring device, and each component interposed from the aperture lever to the aperture blade. The adjustment is performed by continuously changing the relative angular position. However, the amount of adjustment is very small and depends on the intuition of the operator, and cannot be adjusted while measuring. Therefore, the operator must repeat the measurement and adjustment until the aperture diameter falls within the standard.

[0003]

An object of the present invention is to provide an adjustment mechanism which requires only one measurement and adjustment for adjusting the aperture diameter of an aperture opening / closing device at the time of assembly, and can be adjusted in a shorter time.

[0004]

SUMMARY OF THE INVENTION The present invention provides a plurality of aperture blades each having a support pin and a drive pin at one place; a fixed ring; a support ring supporting a support pin of the aperture blade; An opening / closing ring that opens and closes the aperture by relative rotation with respect to the support ring, characterized in that a means for changing the relative angular position of the fixed ring and the support ring at the time of assembly and fixing is provided in a stepwise manner. I have. The above-described aperture opening / closing device may be provided with an aperture lever that rotates integrally with the opening / closing ring, and a means for changing the relative angular position of the opening / closing ring and the aperture lever when the assembly is fixed. Both the adjustment mechanism using the support ring and the adjustment mechanism using the aperture lever may be provided, or only one of them may be used. Further, the relative angular positions of the fixed ring and the supporting ring, and the relative positions of the aperture lever and the opening / closing ring may be changed at an equal angular pitch or not at an equal angular pitch.

The relative angular position between the fixed ring and the support ring in the adjustment mechanism using the support ring is 0 ° <α <(360 /
N) The angle α that satisfies the angle is defined as (360)
/ N × n ± α) ° is preferably changed stepwise at an angular interval (n is an arbitrary natural number) because the same adjustment result as changing only α is obtained. Similarly, the relative angular position between the opening / closing ring and the aperture lever in the adjustment mechanism using the aperture lever is (360 / N) with an arbitrary angle β satisfying 0 ° <β <(360 / N) ° as a fine adjustment angle amount. × n '±
β) It may be changed stepwise at angular intervals of ° (n 'is an arbitrary natural number). Both the adjustment mechanism using the support ring and the adjustment mechanism using the aperture lever may be provided, or only one of them may be used.

When the fine adjustment angle α is smaller than the rotation angle of the opening and closing ring required for the diaphragm operation for changing the exposure value by 1 Ev, fine adjustment can be performed by an adjustment mechanism using a support ring. Further, the adjustment angle amount β is set to an exposure value of 1E.
Even if the angle is smaller than the rotation angle of the aperture lever required for the aperture operation to change v, fine adjustment can be performed by an adjustment mechanism using the aperture lever. Of course, both of these adjustment mechanisms may be provided, and in that case, fine and wide adjustment can be preferably performed by a combination of α and β. α <β
Then, the support ring side can be a fine adjustment mechanism and the aperture lever side can be a coarse adjustment mechanism. The opposite, that is, α> β,
It is also possible to use a rough adjustment mechanism on the support ring side and a fine adjustment mechanism on the aperture lever side.

The means for changing the relative angular position between the fixed ring and the support ring has a structure in which a projection provided on the inner peripheral surface of the fixed ring fits into one of a plurality of grooves provided on the outer peripheral surface of the support ring. ,
The means for changing the relative angular position between the opening / closing ring and the aperture lever may have a structure in which the aperture lever is inserted into one of a plurality of aperture lever engaging grooves provided on the end face of the opening / closing ring without play in the circumferential direction. .

[0008]

FIG. 1 is a cross-sectional view of an interchangeable lens barrel for a single-lens reflex camera provided with an aperture opening / closing device having eight (N = 8) aperture blades 10 to which the present invention is applied. On the inner periphery of the fixed ring 11, a first step portion 11a having an inner diameter equal to the outer diameter of the support ring 12 and holding the support ring 12 is formed. The support ring 12 is held between the first step 11a of the fixed ring 11 and the filter frame 14. Here, the fine adjustment angle α of the aperture diameter by the support ring 12 is set to α = 10 ′ (constant), and the support ring 12 is
b, 12c, 12d, 12e, 12c ', 12d', 1
2e ′ is an angle pitch of 44 ° 50 ′ (= 360 / N ° −
10 ') (three on each side of the U groove 12b, which is a design reference position) (FIG. 3). Conventionally, the U-groove is provided only at the design reference position, and there is no room for adjustment. In the present embodiment, the first step portion 11a of the stationary ring 11
On the inner circumference of the support ring 12 engages with the U groove of the support ring 12.
Are provided at one position, and the engagement protrusion 11b engages with any one of the U-shaped grooves, so that the support ring 1 with respect to the fixed ring 11 is provided.
2 are determined.

The fixed ring 11 is also formed with a second step portion 11c having the same inner diameter as the outer diameter of the opening / closing ring 13.
The opening / closing ring 13 is rotatably fitted in the second step portion 11 c of the fixed ring 11, and is sandwiched and held by the filter frame 14 via the support ring 12. Here, the coarse adjustment angle amount β of the aperture diameter by the aperture lever 15 is set to β = 1 ° (constant), and the opening and closing ring 13 engages with the aperture lever 15 in the circumferential direction without play in the circumferential direction. 13c, 13d,
13e, 13c ', 13d', and 13e 'are 44 ° (= 3
Seven locations (three locations on each side of the engagement groove 13b, which is a design reference position) are provided at an angular pitch of 60 / N ° -1 ° (FIG. 4). Conventionally, the engagement groove is provided only at the design reference position, and there is no room for adjustment. In the present embodiment, the angular position of the opening / closing ring 13 is determined by engaging the aperture lever 15 with one of the engagement grooves.

A release ring 16 is fixed to the aperture lever 15. The release ring 16 is rotatable around the optical axis. An aperture release plate 17 is fixed to the release ring 16. The aperture release plate 17 is engaged with a camera body side release plate (not shown) and is operated from the camera body side. Conventionally, as shown in FIGS. 5 and 6, a long groove 17a is provided in the aperture release plate 17, and the aperture release plate 17 is fixed to the release ring 16 by using a set screw 18. Only the relative angular position between the diaphragm and the release plate 17 is adjusted. In the present embodiment, as shown in FIG.
And it is fixed without adjustment white.

The aperture blade 10 has a support pin 10a and a drive pin 10b on the subject side and the film surface side, respectively. The support pin 10a is fitted and supported in the cam groove 12a of the support ring 12 (FIG. 3). The drive pin 10b is fitted and supported in a drive hole 13a of the opening and closing ring 13 (FIG. 4).
When the opening and closing ring 13 is rotated, a required interval (45 ° here) is set.
The aperture opening is opened and closed by the aperture blades 10 provided at (N = 8 at intervals). That is, since the drive hole 13a and the drive pin 10b are rotated by the rotation of the opening / closing ring 13, all the aperture blades 10 rotate about the optical axis, and at the same time, the support pins 10a slide along the cam grooves 12a, and the respective aperture blades 10 Is a conventionally known aperture opening / closing mechanism that rotates around the drive pin 10b. In this embodiment, when the opening / closing ring 13 is rotated clockwise around the optical axis by 4 ° when viewed from the subject side, the 1Ev aperture diameter increases. Hereinafter, adjustment at the time of assembling the aperture opening / closing device according to the present embodiment will be described.

First, the support ring 12 and the fixed ring 11, and the opening and closing ring 13 and the aperture lever 15 are engaged at the design reference position, and the aperture diameter is measured. Ideally, the measured aperture diameter should be within the standard, but it will be out of the standard depending on the processing accuracy and assembly accuracy of each part, so adjustment is necessary.

The drive pin 10b of the aperture blade 10 and the opening / closing ring 1
3 is disengaged from the drive hole 13a, and the aperture lever 15
When the engagement groove of the opening / closing ring 13 that engages with the first engagement groove 13c is shifted from the engagement groove 13b that is the reference position to the first engagement groove 13c that is adjacent in the counterclockwise direction around the optical axis when viewed from the film surface side, Ring 1
The angular position of 3 rotates clockwise by 44 °. Opening and closing ring 13
Has only eight drive holes 13a at equally-spaced positions on a concentric circle, so that clockwise 44 ° rotation of the opening and closing ring 13 is the same as counterclockwise 1 ° rotation. That is, in this embodiment, since the rotation of 4 ° corresponds to the change of 1Ev, the rotation of 1 ° in the counterclockwise direction is a coarse adjustment for increasing the exposure value by ４Ev. If it is desired to increase the adjustment amount, when the opening and closing ring 13 is shifted to the engagement groove 13d, the angular position of the opening and closing ring 13 is rotated by 88 ° clockwise, which is the same as the counterclockwise rotation of 2 °. This is a rough adjustment to increase 2Ev. If the opening diameter (exposure value) is to be reduced, the engaging groove 1 in the opposite direction (clockwise around the optical axis as viewed from the film surface side) is used.
3c '. Since the engagement grooves are provided at three locations on both sides of the engagement groove 13b, coarse adjustment of up to ± 3 ° is possible. After the adjustment, the drive pin 10b of the aperture blade 10 and the drive hole 13a of the opening / closing ring 13 are engaged again.

The support pin 10a of the aperture blade 10 and the support ring 1
2 is disengaged from the cam groove 12a, and the U groove of the support ring 12 that engages with the engagement protrusion 11b of the fixed ring 11 is moved from the reference position, the U groove 12b, around the optical axis as viewed from the subject side. When the support ring 12 is shifted to the first U-groove 12c adjacent in the counterclockwise direction, the angular position of the support ring 12 rotates clockwise by 44 ° 50 ′. Since the support ring 12 has only eight cam grooves 12a at equal positions on the concentric circle, the clockwise rotation of the support ring
A 0 'rotation is the same as a 10' counterclockwise rotation. That is, in this embodiment, since the rotation of 4 ° corresponds to the change of 1Ev, the rotation of 10 ′ reduces the exposure value to 1 / 24E.
Fine adjustment to increase v. When the adjustment amount is increased, if the support ring 12 is shifted to the U groove 12d, the angular position of the support ring 12 rotates 89 ° 40 ′ in the counterclockwise direction.
The result is the same as that of the 0 'rotation, which is fine adjustment for increasing the exposure value by 1/12 Ev. Since the U-groove is provided at three places on both sides of the U-groove 12b, fine adjustment of ± 30 'at the maximum is possible. After the adjustment, the support pin 10a of the aperture blade 10 and the cam groove 12a of the support ring 12 are engaged again.

In this embodiment, if the fine adjustment and the coarse adjustment by the adjustment mechanism described above are combined, the adjustment range is ± 3 ° 30 ', 10' pitch (in terms of exposure value, the adjustment range is Can be adjusted at ± 7/8 Ev, 1/24 Ev pitch), so that the adjustment may be made to an appropriate adjustment amount based on the measurement result.

In the above-described embodiment, the adjustment intervals α and β of the adjustment mechanism are equal pitches. However, the adjustment intervals (α and β) do not need to be equal pitches, and may be set to any angle intervals. Good. For example, the angle between the U groove 12b and the U groove 12c is 4
4 ° 50 ′ (α ₁ = 10 ′), U groove 12c and U groove 12d
Angle of 44 ° 40 '(α ₂ = 20'), U groove 12d
Angle between the U-groove 12e and 44 ° 30 '(α ₃ = 30')
, The adjustment intervals are 10 ', 30', and 60 'with respect to the reference position, so that they are 1 / 24Ev and 1 / 8E, respectively.
v, 1/4 Ev can be adjusted.

Further, only one of the coarse adjustment mechanism using the aperture lever 15 and the fine adjustment mechanism using the support ring 12 may be provided. Further, it is also possible that the support ring 12 side is a coarse adjustment mechanism and the aperture lever 15 side is a fine adjustment mechanism, that is, α> β.

[0018]

According to the present invention, the adjustment of the aperture diameter of the aperture opening / closing device can be performed in a wide range, finely and stepwise, so that the adjustment is easy and easy to understand, and the working time can be shortened as compared with the prior art.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a lens barrel to which an adjustment mechanism at the time of assembling an aperture opening / closing device according to the present invention is applied.

FIG. 2 is a partial view of a release plate of a lens barrel to which an adjusting mechanism for assembling the aperture opening / closing device according to the present invention is viewed from a film surface side.

FIG. 3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a sectional view taken along line IV-IV in FIG.

FIG. 5 is a side sectional view of a conventional lens barrel.

FIG. 6 is a partial view of a release plate of a conventional lens barrel viewed from a film surface side.

[Explanation of symbols]

Reference Signs List 10 aperture blade 10a support pin 10b drive pin 11 fixed ring 11a first step 11b engagement projection 11c second step 12 support ring 12a cam groove 12b U groove (design reference position) 12c 12d 12e 12c '12d' 12e
U groove 13 opening / closing ring 13 a drive hole 13 b engagement groove (design reference position) 13 c 13 d 13 e 13 c ′ 13 d ′ 13 e
´ Engagement groove 14 Filter frame 15 Aperture lever 16 Release ring 17 Aperture release plate 17a Long groove 18 Set screw

Claims (13)

[Claims] A plurality of aperture blades each having a support pin and a drive pin at one position; a fixed ring; a support ring supporting the support pins of the aperture blade; an optical axis supporting the drive pin of the aperture blade; An opening / closing ring that is freely rotatable around and opens and closes the aperture by relative rotation with respect to the support ring, wherein the fixed ring and the support ring are assembled and fixed between the fixed ring and the support ring. A mechanism for assembling a diaphragm opening / closing device, comprising means for changing a relative angular position in a stepwise manner. 2. A plurality of aperture blades each having a support pin and a drive pin at one position; a fixed ring; a support ring supporting the support pins of the aperture blade; and an optical axis supporting the drive pin of the aperture blade. An opening / closing ring that is freely rotatable around and opens and closes the aperture by relative rotation with respect to the support ring; an aperture lever that engages with the opening / closing ring, rotates integrally, and operates an aperture opening during aperture operation according to its angular position. And a means for gradually changing the relative angular position of the opening and closing ring and the aperture lever when the assembly is fixed between the aperture lever and the opening and closing ring. Adjustment mechanism for assembling the aperture opening / closing device. A plurality of aperture blades each having a support pin and a drive pin, a fixed ring, a support ring supporting the support pins of the aperture blades, and an optical axis supporting the drive pins of the aperture blades. An opening / closing ring that is freely rotatable around and opens and closes the aperture by relative rotation with respect to the support ring; an aperture lever that engages with the opening / closing ring, rotates integrally, and operates an aperture opening during aperture operation according to its angular position. Means for stepwise changing the relative angular position between the fixed ring and the support ring when assembling and fixing the support ring to the fixed ring; and A mechanism for assembling a diaphragm opening / closing device, comprising means for stepwise changing the relative angular position between the opening / closing ring and the diaphragm lever when fixing. 4. An N-number (N> 1) aperture blade having one support pin and one drive pin; a fixed ring; a support ring supporting the support pin of the aperture blade; and a drive pin of the aperture blade. An opening / closing ring that supports and rotates freely around the optical axis and opens and closes the aperture by relative rotation with respect to the support ring. An aperture α that satisfies 0 ° <α <(360 / N) ° As a fine adjustment angle amount, when assembling and fixing the support ring to the fixed ring,
The relative angular position between the fixed ring and the support ring is defined as (360 / N ×
A mechanism for assembling an aperture opening / closing device, comprising means for changing the aperture stepwise at an angular interval of (n ± α) ° (n is an arbitrary natural number). 5. An N-piece (N> 1) aperture blade having a support pin and a drive pin at one place; a fixed ring; a support ring for supporting the support pin of the aperture blade; and a drive pin of the aperture blade. An opening / closing ring that supports and is freely rotatable around the optical axis and opens and closes the aperture by relative rotation with respect to the support ring. An arbitrary angle satisfying 0 ° <β <(360 / N) °. When β is a fine adjustment angle amount, when assembling and fixing the aperture lever to the opening / closing ring, the relative angular position between the opening / closing ring and the aperture lever is
An adjustment mechanism for assembling a diaphragm opening / closing device, wherein means for changing the aperture in a stepwise manner at an angular interval of (360 / N × n ± β) ° (n is an arbitrary natural number) is provided. 6. An N number of (N> 1) aperture blades each having a support pin and a drive pin, a fixed ring, a support ring supporting the support pins of the aperture blade, and a drive pin of the aperture blade. An opening / closing ring that supports and is rotatable around the optical axis and opens and closes the aperture by relative rotation with respect to the support ring. When the support ring is assembled and fixed to the fixed ring, Means for changing the relative angular position of the aperture ring and the support ring in a stepwise manner at an angular interval of (360 / N × n ± α) ° (n is an arbitrary natural number); In addition, the relative angular position between the opening / closing ring and the aperture lever is set to (360 /
An adjusting mechanism for assembling a diaphragm opening / closing device, comprising means for changing stepwise at angular intervals of (N × n ′ ± β) ° (n ′ is an arbitrary natural number). 7. N (N> 1) aperture blades each having one support pin and one drive pin; a fixed ring; a support ring supporting the support pins of the aperture blade; and a drive pin of the aperture blade. An opening / closing ring that supports and rotates freely around the optical axis and opens and closes the aperture by relative rotation with respect to the support ring. The small angle is set as the fine adjustment angle amount α, and when the support ring is assembled and fixed to the fixed ring, the relative angular position between the fixed ring and the support ring is set at an angular interval (n / n) of (360 / N × n ± α) °. An adjusting mechanism at the time of assembling the aperture opening / closing device, wherein a means for changing the aperture stepwise by an arbitrary natural number is provided. 8. An N number of (N> 1) aperture blades each having one support pin and one drive pin; a fixed ring; a support ring supporting the support pins of the aperture blade; and a drive pin of the aperture blade. An opening / closing ring that supports and rotates freely around the optical axis and opens and closes the aperture by relative rotation with respect to the support ring. When the aperture lever is assembled and fixed to the opening / closing ring, the relative angle position between the opening / closing ring and the aperture lever is set to (360 / N × n ± β) °.
Characterized in that a means for changing the aperture in a stepwise manner at an angular interval (n is an arbitrary natural number) is provided. 9. An N-number (N> 1) aperture blade having one support pin and one drive pin; a fixed ring; a support ring supporting the support pin of the aperture blade; and a drive pin of the aperture blade. An opening / closing ring that supports and rotates freely around the optical axis and opens and closes the aperture by relative rotation with respect to the support ring. A small angle is defined as a fine adjustment angle amount α, and an angle smaller than the rotation angle of the aperture lever required for the aperture operation for changing the exposure value by 1 Ev is defined as an adjustment angle amount β, when the support ring is assembled and fixed to the fixed ring. Means for changing the relative angular position of the aperture ring and the support ring stepwise at an angular interval of (360 / N × n ± α) ° (n is an arbitrary natural number); The opening and closing ring and the aperture lever A mechanism for changing the relative angular position in a stepwise manner at an angular interval of (360 / N × n ′ ± β) ° (n ′ is an arbitrary natural number) is provided. . 10. The assembling / adjusting mechanism for an aperture opening / closing device according to claim 6, wherein α and β satisfy α <β. 11. The assembling / adjusting mechanism for an aperture opening / closing device according to claim 6, wherein α and β satisfy α> β. 12. The method according to claim 1, 3, 4, 6, 7, 9 or 1.
In the adjusting mechanism for assembling the aperture opening / closing device according to any one of the above items 1, the means for changing the relative angular position of the fixed ring and the support ring is provided at an arbitrary angular interval on the outer peripheral surface of the support ring. An assembling adjustment mechanism for a diaphragm opening / closing device, comprising: a plurality of grooves; and a projection provided on an inner peripheral surface of the fixed ring and fitted into one of the plurality of grooves. 13. The adjusting mechanism for assembling the aperture opening / closing device according to claim 2, wherein a relative angular position between the opening / closing ring and the aperture lever is changed. The means includes a plurality of aperture lever engagement grooves provided at arbitrary angular intervals on an end face of the opening and closing ring, and the aperture opening / closing aperture which is inserted into any of these engagement grooves without play in the circumferential direction. Adjustment mechanism when assembling the device.