JP2002090798A - Diaphragm device for camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow a diaphragm device for a camera which performs stop operation by moving multiple diaphragm blades by the relation between a cam groove and an engagement pin to perform smooth stop operation by preventing the engagement pin from being caught. SOLUTION: This device is equipped with the diaphragm blades 20 which stops an opening part 10a, a ring member 30 which drives the diaphragm blades, cam grooves 31 to 37 and engagement pins 22a to 22g transmitting the operation of the ring member 30 to the diaphragm blades 20, and a stepping motor 40; when the diaphragm blades 20 are placed in stopping operation and non-stopping operation through the rotation of the ring member 30, movement areas 31b to 37b of the cam grooves 31 to 37 are all made different in position and the diaphragm blades 20 start the stopping operation and finish the non-stopping operation all in different timing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aperture device for a camera for adjusting the exposure of a camera, and more particularly to an aperture device for a camera which performs an aperture operation and a non-aperture operation by interlocking a plurality of aperture blades using a ring member. Related to the device.

[0002]

2. Description of the Related Art As a conventional diaphragm device for a camera, for example, those shown in FIGS. 8 and 9 are known. As shown in the figure, the camera diaphragm apparatus includes a base plate 1 having an opening 1a for exposure, a plurality of diaphragm blades 2 arranged around the opening 1a, and a ring member for driving the plurality of diaphragm blades 2. 3 and a stepping motor 4 for applying a driving force to the ring member 3
Etc. are provided.

As shown in FIGS. 8 and 9, the plurality of diaphragm blades 2 have the same shape, and a support shaft 2a planted in a part thereof is inserted into a support hole of the main plate 1 to be rotatable. And has engagement pins 2b implanted at other positions. On the other hand, as shown in FIG. 9, the ring member 3 is formed in an annular shape so as to substantially overlap with the plurality of aperture blades 2 arranged in an annular shape and in a non-apertured state, and a plurality of cam grooves for receiving the respective engagement pins 2b. 3a. The plurality of cam grooves 3a all have the same shape, and a non-working area 3a 'in which no cam action is performed, and a working area 3 in which the cam action is performed.
a '' and the transition area 3a '''' connecting these areas
Are formed.

That is, the plurality of cam grooves 3a have the same positional relationship among the non-working area 3a ', the transition area 3a''', and the working area 3a ''. When an aperture operation is to be performed by the camera aperture device, the stepping motor 4 is activated, the ring member 3 is rotated clockwise, and the plurality of aperture blades 2 are each brought close to the center, thereby obtaining a desired aperture. Can be caliber.
On the other hand, when performing a non-aperture operation for canceling the aperture operation, the step motor 4 is started in the reverse direction, the ring member 3 is rotated counterclockwise to move the plurality of aperture blades 2 outward in the radial direction. Thus, the opening 1a can be fully opened.

[0005]

By the way, in the aperture operation and the non-aperture operation of the above-mentioned conventional aperture device for a camera, as shown in FIG. 9 in particular, each of the engaging pins 2b of the plurality of aperture blades 2 Non-working area 3a 'to working area 3
When moving to a '' or when moving from the working area 3a '' to the non-working area 3a ', the inflection point (inflection point)
Are all passed simultaneously. Therefore, there is a problem that the engagement pin 2b is easily caught in the transition region 3a '''', the aperture blade 2 is not smoothly interlocked, and it is difficult to reliably perform the aperture operation and the non-aperture operation at desired timing. Also,
In order to forcibly interlock the aperture blade 2 in the stuck state, it is necessary to increase the driving force (torque) of the step motor 4, which leads to an increase in power consumption.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and an object of the present invention is to make it possible to smoothly perform the interlocking operation between a ring member and an aperture blade so that the aperture operation and non-operation can be performed. An object of the present invention is to provide a diaphragm device for a camera that can achieve a smooth diaphragm operation, reduce power consumption, and the like.

[0007]

A camera diaphragm apparatus according to the present invention comprises a substrate having an opening for exposure and a substrate arranged rotatably with respect to the substrate and around the opening so as to cooperate with each other. A plurality of diaphragm blades for performing a diaphragm operation of the opening, a ring member rotatably provided with respect to the substrate for driving the plurality of diaphragm blades, and an operation of the ring member transmitted to the plurality of diaphragm blades for interlocking Interlocking means, and a drive source for exerting a driving force on the ring member, a diaphragm device for a camera for performing a diaphragm operation and non-aperture operation to a plurality of aperture blades by rotating the ring member, the interlocking means, It is characterized in that at least some of the plurality of aperture blades are formed so as to start the aperture operation or end the non-aperture operation at a different timing from the other aperture blades. According to this configuration, the ring member is driven,
When the plurality of aperture blades perform the aperture operation or the non-aperture operation (the operation from the aperture state to the non-aperture state), the plurality of aperture blades are not all at the same time, and at least some of the aperture blades are other aperture blades. Since the aperture operation is started or the non-aperture operation is ended at a timing different from that described above, the switching of the operation is performed smoothly, whereby the aperture operation or the non-aperture operation is performed smoothly, and the load on the drive source is reduced. .

In the above structure, the interlocking means is formed in one of the plurality of aperture blades and the ring member so as to correspond to each of the plurality of aperture blades, and has an operation area for transmitting the operation of the ring member, a non-operation area for not transmitting the operation, and A plurality of cam portions having a transition region located between the active region and the non-active region; and a plurality of engagements formed on the other of the plurality of aperture blades and the ring member to engage with each of the plurality of cam portions. And a transition region in each of the plurality of cam portions is formed at a position where the plurality of engagement portions start engaging at different timings with respect to the rotation of the ring member. be able to. According to this configuration, when the ring member is driven and the plurality of aperture blades perform the aperture operation or the non-aperture operation (the operation from the aperture state to the non-aperture state), the non-operation area, the transition area, and the operation. The engaging portion moves the cam portion in the order of the regions, and in the order of the active region, the transition region, and the non-active region. At this time,
Since the plurality of engaging portions pass through the transition region of the cam portion at different timings (begin to engage with the transition region of the cam portion), the squeezing operation or the non-throttle operation is performed smoothly,
The load on the drive source is also reduced.

In the above structure, the plurality of cam portions include a plurality of cam grooves formed in the ring member, and the plurality of engaging portions are formed in the plurality of aperture blades and move to the plurality of cam grooves, respectively. It is possible to adopt a configuration that includes a plurality of engagement pins that are engaged with each other, the plurality of cam grooves have a bent shape in the transition region, and have the transition regions at different positions from each other. According to this configuration, when the ring member is driven and the plurality of aperture blades perform the aperture operation or the non-aperture operation (the operation from the aperture state to the non-aperture state), the non-operation area, the transition area, and the operation. Each engaging pin moves in the corresponding cam groove in the order of the areas, and in the order of the active area, the transition area, and the non-active area. At this time, the plurality of engagement pins are
Since the cam pins pass through the transition areas of the corresponding cam grooves at different timings, the engagement pins are prevented from being caught in the bent transition areas. As a result, the aperture operation or the non-aperture operation is performed smoothly, and the load on the drive source is reduced.

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 7 show an embodiment of a camera diaphragm device according to the present invention.
1 is a plan view showing the overall configuration and one operation mode, FIG. 2 is a cross-sectional view, FIGS. 3 to 5 are plan views showing some components, and FIGS. 6 and 7 are plan views showing one operation mode. It is.
In the drawings, what should be represented by a dotted line is indicated by a solid line for convenience of explanation. As shown in FIGS. 1 and 2, a diaphragm device for a camera according to this embodiment includes a base plate 10 as a substrate having an opening 10 a for exposure, and a base plate 10.
Plural (7 in this case) provided rotatably with respect to
Aperture blade 20, a ring member 30 for driving the plurality of aperture blades 20, a step motor 40 as a drive source for applying a driving force to the ring member 30, and a ring member 30.
A holding plate 50 for holding the pressure is provided as a basic configuration.

As shown in FIG. 1, the base plate 10 has a disk shape, has an opening 10a for exposure at the center thereof, and has seven support holes 10b at equal intervals around the opening 10a. are doing. Further, an annular stepped portion 10c that rotatably supports the ring member 30 is provided radially outside the support hole 10b.

As shown in FIGS. 4 and 5, the plurality of aperture blades 20 each have a substantially rhombic shape, and are spaced apart from the support pin 21 implanted at one end by a predetermined distance. Pin 22 (22a, 22b, 22c, 22c,
22d, 22e, 22f, 22g), and are all formed as the same. Each of the plurality of aperture blades 20 has a support pin 21 inserted into a support hole 10b of the base plate 10 to be rotatably supported by the base plate 10, and each of the engagement pins 22a to 22g is a ring member. 30 are inserted into the cam grooves (cam portions) 31 to 37 formed in the groove 30, and are guided along the passages of the cam grooves 31 to 37. And a plurality of aperture blades 20
Are arranged so that a part thereof overlaps in a non-apertured state, and as a whole, as shown in FIG.

The ring member 30 is rotated by its rotation.
A plurality of aperture blades 20 perform an aperture operation or a non-aperture operation. As shown in FIG. 4, the aperture blade 20 is formed in an annular shape having an opening 30a having a diameter slightly larger than the opening 10a of the base plate 10 at the center thereof. And a plurality of (here, seven) cam grooves 31 to 37 as cam portions forming a part of interlocking means arranged at substantially equal intervals in the circumferential direction. A gear portion 30b meshed with a two-stage gear 45 (small gear 45b) forming a part of the step motor 40
have. As shown in FIG. 2, the ring member 30 is supported in the radial direction and the axial direction by the step portion 10c of the base plate 10, and furthermore, the pressing plate 5
By attaching 0, it is in a state of being rotatably supported coaxially with the center of the opening 10a.

As shown in FIG. 4, the plurality of cam grooves 31 to 37 each have a non-operating region 31a to 37a which does not perform a cam function (a driving force of the ring member 30 is not transmitted) and a cam function (a ring function). (The driving force of the member 30 is transmitted) and the transition regions 31b to 37b which are located between the non-operation regions 31a to 37a and the operation regions 31c to 37c and connect the two regions. It bends at the positions of the transition areas 31b to 37b to form a substantially rectangular shape as a whole. The plurality of cam grooves 31
As shown in FIG. 3, each of the transition areas 31b to 37b is positioned at a different position, and as shown in FIG.
To 22g, the transition regions 31b, 32b, 33b, 34b, 35b, 36b, 3 with respect to the rotation of the ring member 30.
7b in order. That is, the engagement pins 22a to 22g all pass through the transition areas 31b to 37b at different timings.

Here, the operation of the ring member 30 will be described with respect to one diaphragm blade 20. When the diaphragm blade 20 is at the position shown in FIG. When rotated around, the engagement pin 2
2b is the transition region 32 from the non-working region 32a of the cam groove 32.
After passing through b, it proceeds to the action area 32c. At this time, the aperture blade 20 starts rotating counterclockwise, and as shown in FIG.
When the ring member 30 further rotates and reaches the clockwise rotation end, the aperture blade 20 is positioned in the aperture state in which the aperture 10a is reduced to the smallest diameter in cooperation with the other aperture blades 20. On the other hand, the ring member 30 is shifted from the drawn state shown in FIG.
Rotates counterclockwise, the engaging pin 22b follows the reverse path of the action area 32c, the transition area 32b, and the non-action area 32a, and the aperture blade 20 returns to the non-iris state shown in FIG. .

The above series of operations are performed on all the aperture blades 20. However, since the positions of the transition areas 31b to 37b in the cam grooves 31 to 37 are different, the respective engagement pins 22a to 22g are During the throttle operation, the non-operational regions 31a to 37a to the operation regions 31c to 3c
7c, they all pass through the transition regions 31b to 37b at different timings. On the other hand, during the non-throttle operation, the operation regions 31c to 37c are moved from the non-operation region 31a
To 37a, they all pass through the transition areas 31b to 37b at different timings. By such an interlocking relationship, the engagement pins 22a to 22g are prevented from being caught in the transition areas 31b to 37b, and the aperture blade 20 is smoothly moved.

As shown in FIGS. 1 and 2, a stepping motor 40 as a driving source is a multi-pole magnetized permanent magnet unit 4.
A rotor 41 having a gear 1a and a gear 41b;
, A pair of yokes (stators) 42, 43 arranged so as to face each other, a coil 44 for excitation wound around these yokes 42, 43, and a gear 4 of the rotor 41.
1b, and a two-stage gear 45 integrally provided with a small gear 45b meshing with the gear portion 30b of the ring member 30. These are all attached to the base plate 10 via the holding member 46. Have been. In this step motor 40, the rotor 41 rotates stepwise or continuously in response to an applied power pulse. The rotation angle changes in proportion to the number of input pulses, and the rotor 41 rotates in proportion to the input frequency. The speed changes. Therefore, by appropriately adjusting the directions of the power pulse and the rotating magnetic field, the positioning of the ring member 30 is controlled to a desired angular position.

Next, the operation when the above-mentioned camera diaphragm device is applied to a camera will be described with reference to FIGS. 1, 6 and 7. FIG. Here, for a camera to which the camera aperture device is applied, a photometer for detecting the brightness of the subject light, a control unit (CPU) for controlling the step motor 40 and various controls, and for performing aperture according to the brightness. And a storage unit for storing the control map and the like.

First, this aperture stop for a camera is in a non-stop state in which the aperture blade 20 fully opens the opening 10a as shown in FIG. 1 in a rest state. In this state, if it is determined based on the output signal of the photometer that the aperture 10a needs to be reduced to the maximum, the stepping motor 40 (the rotor 4) is controlled based on the control signal output from the control unit.
1) is rotated (activated) clockwise. Then, the ring member 30 starts rotating clockwise through the two-stage gear 45. By the clockwise rotation of the ring member 30, the engagement pins 22a to 22g located at the moving ends of the non-operating regions 31a to 37a in the cam grooves 31 to 37, respectively.
Moves the non-action areas 31a to 37a by a predetermined distance. In this section, since the driving force of the ring member 30 is not transmitted to the diaphragm blade 20, the diaphragm blade 20 is kept in the initial state. And the transition areas 31b to 3b
7b, and the action areas 31c to 3c to start the aperture operation
Move to 7c.

Here, when the engaging pins 22a to 22g pass through the transition areas 31b to 37b, first, as shown in FIG. 6, the engaging pins 22a pass through the transition area 31b of the cam groove 31, and The engagement pin 22b is moved to the transition region 3 of the cam groove 32.
2b, then the engaging pin 22c passes through the transition region 33b of the cam groove 33, and then the engaging pin 22d
, The engaging pin 22e then passes through the transition area 35b of the cam groove 35, and then the engaging pin 22f
Passes through the transition area 36b of the cam groove 36, and finally, the engagement pin 22g passes through the transition area 37b of the cam groove 37.

That is, the engaging pins 22a to 22g all pass through the transition areas 31b to 37b at different timings (begin to engage with the transition areas 31b to 37b). Therefore, the engaging pins 22a to 22g move to the action areas 31c to 37c smoothly without being caught at the positions of the transition areas 31b to 37b, as compared with the case where they all pass (engage) at the same timing. I do. As a result, the plurality of aperture blades 20 smoothly start the aperture operation, and the load applied to the step motor 40 is maintained at a desired level required for the aperture operation without extremely increasing.

When the ring member 30 continues to rotate clockwise by the further stepping drive of the step motor 40, the engaging pins 22a to 22g continue to move in the action areas 31c to 37c of the cam grooves 31 to 37. With this move,
The seven diaphragm blades 20 rotate counterclockwise around the support pin 21 and approach each other toward the center of the opening 10a, and the engagement pins 22a to 22g move to the moving ends of the action areas 31c to 37c. Leads to. At this time, as shown in FIG. 7, the seven diaphragm blades 20 cooperate with each other to form a diaphragm state in which the opening 10a is maximally squeezed (smaller in diameter).

On the other hand, when releasing the aperture state and returning to the non-aperture state, the step motor 40 is rotated in the reverse direction (counterclockwise) in the state shown in FIG. Then, the ring member 30 starts rotating counterclockwise via the two-stage gear 45. The counterclockwise rotation of the ring member 30 causes the action regions 31c to 3c in the cam grooves 31 to 37 to move.
7c are located at the moving ends of the engaging pins 22a to 22c, respectively.
22g first moves the action areas 31c to 37c by a predetermined distance. In this section, since the driving force of the ring member 30 is transmitted to the aperture blade 20, the aperture blade 20 gradually rotates radially outward from the aperture state while rotating clockwise around the support pin 21. Go away. Then, a non-aperture operation is performed after passing through the transition areas 31b to 37b (operation for shifting from the aperture state to the non-aperture state).
End, and move to the non-action areas 31a to 37a.

Here, when the engagement pins 22a to 22g pass through the transition areas 31b to 37b, the engagement pins 22g are first moved to the transition area 3 of the cam groove 37, contrary to the throttle operation.
7b, then the engaging pin 22f passes through the transition area 36b of the cam groove 36, and then the engaging pin 22e
, The engagement pin 22d passes through the transition area 34b of the cam groove 34, and then the engagement pin 22c.
Passes through the transition region 33b of the cam groove 33, then the engagement pin 22b passes through the transition region 32b of the cam groove 32, and finally, the engagement pin 22a passes through the transition region 31b of the cam groove 31.

That is, the engaging pins 22a to 22g all pass through the transition areas 31b to 37b at different timings (begin to engage with the transition areas 31b to 37b). Therefore, as compared with the case where all pass (engage) at the same timing, the engagement pins 22a to 22g smoothly move to the non-operation areas 31a to 37a without being caught at the transition areas 31b to 37b. Moving. As a result, the plurality of aperture blades 20 smoothly end the non-aperture operation, and the load applied to the step motor 40 is maintained at the desired level required for the non-aperture operation without extremely increasing.

When the ring member 30 continues to rotate counterclockwise by the further stepping drive of the step motor 40,
The engagement pins 22a to 22g continue to move in the non-operating regions 31a to 37a of the cam grooves 31 to 37, and when reaching the moving end, the seven diaphragm blades 20 are opened as shown in FIG. The operation is stopped while maintaining the non-aperture state in which the portion 10a is fully opened.

In the above operation, the ring member 30
Is rotated to the clockwise movement end (the engagement pins 22a to 22a).
22g was moved to the moving end of the action area 31c-37c of the cam groove 31-37), and the operation of narrowing the opening 10a to the maximum was shown. For example, in the middle of increasing the aperture diameter from the state of the maximum aperture. When the squeezed state is formed, the engagement pins 22a to 22g are connected to the action areas 31c of the cam grooves 31 to 37.
By appropriately rotating the ring member 30 so as to move to the middle of the range from 37 to 37c, a desired aperture state can be continuously formed.

In the above embodiment, the ring member 30
The cam grooves 31 to 37 formed in the ring member 30 and the aperture blade 2
Although the configuration including the engagement pins 22a to 22g implanted at 0 is shown, the configuration is not limited to this, and another configuration may be used as long as an interlocking relationship between the two can be obtained. In the above embodiment, the ring member 30 is provided with the cam portions (cam grooves 31 to 37), and the aperture blade 20 is provided with the engaging portions (engaging pins 22a to 22g). An engagement portion is provided on the ring member 30, and the aperture blade 20
The present invention can also be applied to a configuration in which a cam portion (in this case, a band-like projection such as a rib is provided instead of a groove) is provided.

Further, in the above embodiment, the positions of the transition areas 31b to 37b in the plurality of cam grooves 31 to 37 are all different so that all the aperture blades 20 start or stop the aperture operation at different timings. Is terminated, but the position of at least a part (one, two, three, or the like) of the transition regions 31b to 37b in the plurality of cam grooves 31 to 37 is changed to the position of another transition region. The position may be different, and at least some of the aperture blades 20 may start the aperture operation or end the non-aperture operation at a different timing from the other aperture blades 20. Even in this case, it is possible to prevent or suppress the engagement of the engaging portion and the like, and to reduce the load on the step motor 40, as compared with the case where all operate at the same timing.

[0030]

As described above, according to the camera diaphragm apparatus of the present invention, a plurality of diaphragm blades and a plurality of diaphragms which are arranged around the aperture and perform the diaphragm operation of the aperture in cooperation with each other. By forming an interlocking means for interlocking a ring member that exerts a driving force on the blade, at least some of the aperture blades start the aperture operation or end the non-aperture operation at a different timing from the other aperture blades. As compared with the case where all of the plurality of aperture blades simultaneously start the aperture operation or end the non-aperture operation, the switching of the operation from the non-aperture to the aperture or from the aperture to the non-aperture is performed smoothly. As a result, the aperture operation or the non-aperture operation by the plurality of aperture blades is smoothly performed as a whole, and the load on the driving source is reduced.

In particular, the interlocking means includes a cam portion (cam groove) comprising a non-operating region, a transition region, and an operating region, and an engaging portion (engaging pin) engaged with the cam portion (cam groove). When the configuration is adopted, the plurality of engaging portions (engaging pins)
Since they pass through the transition region of the cam portion (cam groove) at different timings (begin to engage with the transition region of the cam portion), the throttle operation or the non-throttle operation is performed smoothly, and the load on the drive source is reduced. .

[Brief description of the drawings]

FIG. 1 is a plan view showing an overall configuration of a camera diaphragm device according to the present invention and an operation form thereof.

FIG. 2 is a sectional view of a camera diaphragm device.

FIG. 3 is a plan view showing a ring member and a plurality of aperture blades that constitute a part of the camera aperture device.

FIG. 4 is a plan view showing a relationship between a ring member and one diaphragm blade.

FIG. 5 is a plan view showing a relationship between a ring member and one diaphragm blade.

FIG. 6 is a plan view showing an operation mode of the camera diaphragm device.

FIG. 7 is a plan view showing an operation mode of the camera diaphragm device.

FIG. 8 is a plan view showing a conventional camera diaphragm device.

FIG. 9 is a plan view showing a ring member and a plurality of aperture blades in a conventional camera aperture device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Base plate (substrate) 20 Aperture blade 22 Engagement pin (engagement part) 30 Ring member 31, 32, 33, 34, 35, 36, 37 Cam groove (cam part) 40 Step motor (drive source) 50 Holding plate

Claims (3)

[Claims] 1. A substrate having an opening for exposure, and a plurality of stops arranged around the opening so as to be rotatable with respect to the substrate and performing a stop operation of the opening in cooperation with each other. A blade, a ring member rotatably provided with respect to the substrate to drive the plurality of aperture blades, interlocking means for transmitting an operation of the ring member to the plurality of aperture blades to interlock with each other, and the ring A driving source for exerting a driving force on the member, a camera diaphragm device for performing a diaphragm operation and a non- diaphragm operation to the plurality of diaphragm blades by the rotation of the ring member, wherein the interlocking means, A diaphragm for a camera, characterized in that at least a part of the diaphragm blades is formed so as to start the diaphragm operation or end the non-diaphragmatic operation at a different timing from the other diaphragm blades. Location. 2. The interlocking means is formed in one of the plurality of aperture blades and the ring member so as to correspond to each of the plurality of aperture blades, and has an action area for transmitting the operation of the ring member and a non-operation area for not transmitting the action. A plurality of cam portions having a region and a transition region located between the working region and the non-working region; and being formed on the other of the plurality of diaphragm blades and the ring member to engage with each of the plurality of cam portions. A plurality of transition portions of the plurality of cam portions are formed at positions where the plurality of engagement portions start to be engaged at different timings with respect to the rotation of the ring member. The diaphragm device for a camera according to claim 1, wherein: 3. The plurality of cam portions are formed of a plurality of cam grooves formed in the ring member, and the plurality of engaging portions are formed on each of the plurality of aperture blades to form the plurality of cam grooves. Comprising a plurality of engagement pins movably engaged with each other, wherein the plurality of cam grooves are bent at the transition region, and have the transition region at different positions from each other. The diaphragm device for a camera according to claim 2, wherein: