JPH0710335Y2 - Caliber adjusting device with step motor as drive source - Google Patents

Description

[Detailed description of the device] [Industrial applications]

The present invention relates to an aperture adjusting device such as a diaphragm device for a single-lens reflex camera, and more particularly to a novel aperture adjusting device that can reduce the number of adjustment steps during assembly in an aperture adjusting device using a step motor as a drive source.

[Prior art]

In the conventional seed diameter adjusting device having a step motor as a driving source, an optical path hole is basically formed, and a base member having a step motor mounted therein and a base member that can freely reciprocate around the optical path hole are provided in the base member. A drive ring that is supported and rotates by transmitting the step rotation of the step motor, and a plurality of optical paths of the same shape in which one end surface of the drive ring is swingably supported at equal intervals and each has a cam follower. A plurality of optical path opening / closing blades are sandwiched between the opening / closing blades and the drive ring, and a cam portion to which the cam followers follow is formed corresponding to each cam follower planted in each of the plurality of optical path opening / closing blades. , A cam ring fixed to the base member, transmitting the rotation of the step motor to rotate the drive ring, By changing the relative turning angle of the serial drive ring, it swung the optical path shutter blades have been made so as to open and close the optical path hole formed in the base member.

[Problems to be solved by the device]

By the way, the aperture adjusting device of this kind is generally adapted to obtain a desired aperture value by rotating a step motor by a predetermined number of pulses from the home position at a fully open position for, for example, open metering. . By the way, when the drive ring is rotated by using the step motor as a drive source like the seed diameter adjusting device, the step motor is discontinuous in step rotation due to its characteristic, and a free position between steps is set as a stop phase. It is not possible. Therefore, generally, for example, a screw hole for mounting is made a long hole so that the fixed angle of the cam ring relative to the base member can be finely adjusted, and the drive ring is rotated when the step motor is in the stop phase. An assembly that fixes the cam ring to the base member by finely adjusting the mounting position of the cam ring with respect to the drive ring so that the optical path opening / closing blade has the desired full aperture diameter when the drive ring is at this reference turning angle based on the angle. I'm working. Further, in the aperture adjusting device using the step motor of the type as a drive source, in order to prevent the home position from being defective due to step-out or overshoot, the drive ring is driven so as to be surely stopped at the fully open position which is the home position. It is necessary to provide a stopper for the ring. In the conventional seed diameter adjusting device, the stopper of the drive ring is generally provided on the base member. Therefore, the fine adjustment of the mounting position of the stopper must be performed along with the fine adjustment of the mounting position of the cam ring. There is a problem in that the number of adjustment steps increases and the chances of adjustment errors increase.

[Means for solving problems]

In view of such problems, the present invention has been made with the object of reducing the number of adjustment steps during assembly. More specifically, the present invention was made by paying attention to the fact that the swing angle of the optical path opening / closing blade is determined by the relative swing angle of the cam ring and the drive ring, and the swing limit corresponding to the fully open position of the drive ring. By forming a stopper for regulating the cam ring on the cam ring, the position of the stopper can be automatically adjusted at the same time by adjusting the position of the cam ring, thereby reducing the number of adjustment steps during assembly. In summary, the aperture adjusting device using a step motor as a driving source according to the present invention includes: a base member having an optical path hole formed therein, and a base member having a step motor mounted thereon: supported by the base member so as to freely reciprocate around the optical path hole. A drive ring which is rotated by transmitting the step rotation of the step motor: a plurality of optical path opening / closing blades of the same shape, which are swingably supported at equal intervals on one end surface of the drive ring and in which cam followers are respectively planted And: a plurality of optical path opening / closing blades are sandwiched between the drive ring, and a cam portion to which the cam followers follow is formed corresponding to each cam follower planted in each of the plurality of optical path opening / closing blades, It is premised on a diameter adjusting device driven by a step motor having a cam ring fixed to a base member: to the base member of the cam ring. To a fixed position relative with the adjustable: in which the stopper for restricting the pivoting limit corresponding to the fully open position of the drive ring formed in the cam ring.

[Action]

The aperture adjusting device using a step motor as a driving source of the present invention basically transfers the rotation of the step motor to the driving ring to control the swing angle of the driving ring with respect to the cam ring, thereby swinging each optical path opening / closing blade. It is designed to determine the moving angle and adjust the aperture. During the assembly work, the mounting angle of the cam ring with respect to the base member is finely adjusted so that the desired full opening diameter can be obtained in the stop phase of the step motor near the fully open position. The stopper for regulating the home position of the drive ring is also required to be finely adjusted in accordance with the stop phase of the step motor at the fully open position.
In the present invention, since the stopper is formed on the cam ring, the mounting position of the stopper can be adjusted at the same time by finely adjusting the mounting position of the cam ring, and it is not necessary to adjust the mounting position of the stopper independently.

【Example】

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. First, FIG. 1 is a mechanism diagram of a diameter adjusting device using a step motor as a drive source according to an embodiment of the present invention. Also, the second
FIG. 3 is a plan view showing a base member 10 which is a component of the above device, FIG. 3 is a plan view showing a drive ring 20 which is a component of the device, and FIG. 4 is a plan view showing a cam ring 30 which is a component of the device. . The base member 10 has an optical path hole 11 for passing through the field hole.
An inner cylinder 12 in which is formed, an outer cylinder 13 concentric with the inner cylinder 12, and an inner cylinder
The base plate 14 that connects the common end surface of the outer cylinder 13 and the outer cylinder 13 is integrally formed, and the inner peripheral surface of the outer cylinder 13 has a bearing surface 15, 16, 17, 18, 19, 19, which is lowered by one step. Has been formed. A rotor shaft 41 of a step motor 40 is rotatably penetrated from the back surface of the base plate 14, and a rotor pinion 42 is fixed to the rotor shaft 41. Also, the base plate 14
A reduction gear 43 meshing with the rotor pinion 42 is rotatably supported on the shaft 111 planted in the. Next, on the outer peripheral portion of the drive ring 20, six support protrusions 21, 22, 23, 24, 25, 26 are formed at equal intervals. In addition, a hole 27 having a diameter larger than the outer diameter of the inner cylinder 12 of the base member 10 is bored in the center of the drive ring 20, and the support projections 21, 22 ...
The diameter of the imaginary circle connecting the tips of 23, 24, 25 is larger than the inner diameter of the corresponding bearing surface 15, 16, 17, 18, 19 and
Since the outer diameter of the corresponding bearing surface 15, 16, 17, 18, 19 is smaller, the drive ring 20 has a bearing surface 15, 16, 17, 17, which the supporting projections 21, 22, 23, 24, 25 respectively correspond to. Supported by 18 ・ 19,
It is incorporated into the outer cylinder 13 so as to be rotatable around the inner cylinder 12.
The support projection 26 has an engaging projection 27 whose function will be clarified later.
Are formed continuously, but the outer cylinder 13 is cut out at the location of the bearing surface 110 corresponding to the support projection 26, and the bearing surface 110 extends to the outer edge portion of the base member 10. Colliding piece 27
Is also supported on the extended bearing surface 17. Further, on the back surface of the drive ring 20, a support protrusion 21 and a support protrusion 22 are provided.
A rack 28 is formed between the two
The reduction gear 43 supported by 111 meshes with the pinion 44 constituting the two-stage gear, the rotation of the pinion 44 is transmitted to the rack 28, and the drive ring 20 turns around the inner cylinder 12. . In addition, bearing holes 29 are provided in each of the support protrusions 21, 22, 23, 24, 25, and 26.
・ 210 ・ 211.212 ・ 213 ・ 214 are drilled and each bearing hole 29.2
The diaphragm blades for opening and closing the optical path hole 11 are pivotally supported on the 10, 21, 212, 213 and 214 so as to be swingable. In FIG. 1, only the diaphragm blades 51 supported in the bearing holes 29 are shown in order to avoid complication of the drawing, but other bearing holes 210, 211, 212.
The diaphragm blades of the same shape are also pivotally supported by 13 and 214. The cam followers 51 are formed on the surfaces of these diaphragm blades, respectively.
a, 52a, 53a, 54a, 55a, 56a are planted. Next, the outer diameter of the cam ring 30 is substantially equal to the outer diameter of the base member 10, through holes 31 having a diameter substantially equal to the optical path hole 11 are formed in the central portion, and the peripheral portions are mounted at equal intervals. The long holes 32, 33 and 34 are drilled in three places. On the other hand, on the front end face of the outer cylinder 13 of the base member 10, corresponding to the elongated holes 32, 33, 34, the mounting bosses 112, 113,
114 are formed, and 112, 113, and 114 have a height that forms a space between the base member 10 and the cam ring 30 that is necessary and sufficient not to interfere with the travel of the diaphragm blades. Each boss 112/113/11
Screw holes 115, 116, 117 are drilled in 4 and long holes 32, 33, 34
The cam ring 30 is fixed to the base member 10 by screwing a screw penetrating through the corresponding screw hole 115, 116, 117. The fixed angle of the cam ring 30 relative to the base member 10 can be finely adjusted within the range of the long holes 32, 33, 34. In FIG. 1, the cam ring 30 is virtually shown by a one-dot chain line in order to show the internal state. In addition, the cam ring 30 has cam grooves 35, 36, 37, 38, 39, and 310 of the same shape at equal intervals corresponding to the cam followers 51a, 52a, 53a, 54a, 55a, and 56a planted in each diaphragm blade. The cam followers 51a, 52a, 53a, 54a, 55a, 56a.
Is driven by the corresponding cam grooves 35, 36, 37, 38, 39, 310. Further, a stopper protrusion 311 is formed on the back surface of the cam ring 30 in a bent manner. The stopper protrusion 311 is engaged with the drive ring 20 when the drive ring 20 is rotated counterclockwise to the fully open position. The protrusion 27 is engaged to stop the left rotation of the drive ring 20. Next, the operation of this embodiment will be described with reference to the above matters. In the state where the whole is assembled as shown in Fig. 1,
When the rotor pinion 42 attached to the rotor shaft 41 of the step motor 40 rotates in a clockwise direction, the reduction gear 43 supported by the shaft 111 rotates in a counterclockwise direction, and the pinion 44 and the drive ring 20 coaxial with this rotate. The drive ring 20 turns clockwise through a rack 28 formed on the back surface. At this time, the cam follower 51a planted in the diaphragm blade 51 pivotally supported in the bearing hole 29 and the same shape as the diaphragm blade 51 and pivotally supported in the other bearing holes 210, 211, 212, 213, 214 are not shown. Cam followers 52a, 53a, 54a, 55a, 56a planted on diaphragm blades
Move leftward while being driven by the corresponding cam grooves 35, 36, 37, 38, 39, and 310, so that the diaphragm blade 51 and each diaphragm blade (not shown) having the same shape as the corresponding blade hole 29・
It swings counterclockwise around 210, 211, 212, 213, and 214, and operates in the direction of blocking the optical path hole 11. On the contrary, when the rotor pinion 42 attached to the rotor shaft 41 of the step motor 40 makes a step rotation counterclockwise,
The drive ring 20 turns counterclockwise through the transmission train, and the cam followers 51a, 52a, 53a, 54a, 55a, and 56a correspond to the diaphragm blade 51 and each diaphragm blade (not shown) of the same shape. Since it moves to the right while being driven by the corresponding cam grooves 35, 36, 37, 38, 39, 310, the corresponding bearing holes 29.
Swing clockwise around 210, 211, 212, 213, 214,
A stopper that operates in the direction of opening the optical path hole 11 and has an engagement protrusion 27 formed on the drive ring 20 formed on the cam ring 30.
The position where it abuts 311 is the fully open position. By the way, as described above, the step motor 40 cannot discontinue step rotation due to its characteristics and set a free position between steps as a stop phase. Therefore, for example, the relative rotation angle of the drive ring 20 with respect to the base member 10 when the rotor shaft 41 is in the stop phase near the fully open position due to the relative mounting angle of the rotor shaft 41 and the rotor pinion 42, etc. There are some differences in Therefore, also in the present embodiment, when the drive ring 20 is at this reference turning angle with reference to the relative turning angle of the drive ring 20 with respect to the base member 10 when the rotor shaft 41 is in the stop phase near the fully open position. So that the diaphragm blades 51 and other diaphragm blades (not shown) have a swing angle corresponding to the desired total aperture diameter.
The relative mounting angle of the cam ring 30 to the base member 10 is finely adjusted during assembly. Fine adjustment of the relative mounting angle of the cam ring 30 to the base member 10 is performed by shifting the mounting long holes 32, 33, 34 formed in the cam ring 30 back and forth. As described above, in the present embodiment, when the drive ring 20 is rotated counterclockwise to the position corresponding to the fully open position, the engaging projection 27 formed on the drive ring 20 is stopped by the stopper 311 formed on the cam ring 30.
Further, the drive ring 20 is restricted from rotating further to the left, but in the case of a cam type blade drive mechanism, the swing angle of the diaphragm blade 51 and other diaphragm blades not shown in the figure is the cam ring of the drive ring 20.
It is determined depending on the turning angle relative to 30, and in this embodiment, the stopper 311 for restricting the left limit of the drive ring 20 is formed on the cam ring 30. Therefore, when the cam ring 30 is attached to the base member 10, if the step angle of the step motor 40 is in the stop phase, the cam ring 30 can be moved back and forth to finely adjust the attachment angle so that the desired opening diameter can be obtained. The position is adjusted,
It is not necessary to adjust the mounting position of the stopper 311 independently. It is also possible to adjust by reverse setup. In other words, with the step motor 40 in the stop phase, the stopper 311
If the mounting angle of the cam ring 30 is adjusted so that the engaging projection 27 and the engaging projection 27 come into contact with each other or have a desired minute interval, the total opening diameter is also adjusted at the same time. In the above description, an example in which the present application is applied to the diaphragm device of a single-lens reflex camera has been shown. However, for example, a device such as a video camera which controls the amount of light passing through the lens by adjusting the aperture, The present invention can be equally applied to any device that cam-drives the blades as a drive source.

【effect】

As described above, according to the present invention, if the mounting position of the cam ring relative to the base member is finely adjusted in accordance with the stop phase of the step motor, the stopper mounting for restricting the fully open position of the drive ring is mounted. Since the fine adjustment of the position is also performed at the same time, it is not necessary to separately adjust the total opening diameter and the stopper mounting position, which reduces the number of steps during assembly. In addition, the chance that an adjustment error will occur is reduced due to the reduction of the number of adjustment points.

[Brief description of drawings]

FIG. 1 is a mechanical view of a diameter adjusting device using a step motor as a drive source according to an embodiment of the present invention, FIG. 2 is a plan view of a base member, FIG. 3 is a plan view of a drive ring, and FIG. The top view of a cam ring. 11 ... Optical path hole, 10 ... Base member 20 ... Drive ring, 27 ... Engagement protrusion 311 ... Stopper, 40 ... Step motor 51 ... Aperture blade, 51a / 52a / 53a / 54a / 55a / 56a …… Cam follower 30 …… Cam ring, 32 ・ 33 ・ 34 …… Long hole 35 ・ 36 ・ 37 ・ 38 ・ 39 ・ 310 …… Cam groove

Claims (1)

[Scope of utility model registration request] 1. A base member in which an optical path hole is formed and a step motor is mounted, and a drive which is supported by the base member so as to freely reciprocate around the optical path hole and which is rotated by transmitting step rotation of the step motor. The ring, a plurality of optical path opening / closing blades of the same shape, which are swingably supported at equal intervals on one end surface of the drive ring and in which cam followers are respectively implanted, and the plurality of optical path opening / closing between the drive ring. A stepping motor having a cam ring, which holds the blades, is formed corresponding to each cam follower planted in each of the plurality of optical path opening / closing blades, and the cam portion is driven by the cam follower, and is fixed to the base member. In the aperture adjusting device using the drive ring as a drive source, the relative fixing position of the cam ring with respect to the base member can be adjusted, and the drive ring can be adjusted. Diameter adjusting device for a stepping motor, wherein a stopper for restricting the pivoting limit corresponding to the fully opened position are formed on the cam ring and the drive source.