JP3469981B2 - Light intensity control device and optical equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light amount adjusting device mounted on a photographing device such as a camera and an optical device such as the photographing device.

[0002]

2. Description of the Related Art Conventionally, this type of light amount adjusting device positions a light amount variable member at a regulating position of a moving range of a light amount variable member as described in Japanese Utility Model Laid-Open No. 3-29837 (conventional example 1) and also forms a gap . A magnet is attracted to the narrowed opposing magnetic pole yoke portion, or is biased and held in one direction by a spring member.

In addition, as described in Japanese Patent Application Laid-Open No. 1-101525 (Prior Art 2), a stepping motor is used to position and hold the aperture.

[0004]

However, the above-mentioned conventional example has the following drawbacks.

(1) In the configuration in which the conventional example 1 is biased and held in one direction, a large amount of power is inevitably consumed in order to hold the aperture opening at the position where the other light amount variable member is restricted in the movement range. There is concern about fever.

(2) In the stepping motor and the like of the second conventional example, the aperture opening accuracy at the holding position cannot be expected.

(3) In the stepping motor or the like of the conventional example 2, the control method such as the drive pulse train shaping is complicated and difficult,
The control drive circuit becomes large in scale, and there is concern about malfunctions such as mistaken steps and abnormal noise.

[0008] (4) In the conventional example 2 of a stepping motor or the like, mechanism is complicated, apparatus becomes large in size and weight reduction, also leads to deterioration of the assembly.

The object of the present invention is to reduce the
With the holding power, the light quantity variable member can be opened and closed at small and open positions.
It is to position and hold with high accuracy .

[0010]

[0011]

[0012]

[0013]

[0014]

[0015]

Means for Solving the Problems The present invention has a light amount varying member that determine the aperture for varying the amount of light, a permanent magnet
Consists of a rotor magnet and a drive coil
Wherein a driving source for driving the light quantity variable member that, a transmission means for transmitting the driving force of the driving source to the light quantity variable member, with openings through which light passes is formed, the light
There are two positions for the variable amount member: the open throttle position and the small throttle position.
The rotor magnet drive range.
Rotation of less than 180 degrees between two positioned positions
A base plate having a stopper for limiting the range, and the rotor
The rotor is arranged with a gap between
By providing a magnetically unstable point in the drive range of the Gnet,
Move the rotor magnet away from the magnetically unstable point.
The urging force is generated in the direction of the two positions
With a ferromagnetic material that generates detent torque
However, by switching the energizing direction to the drive coil,
The open aperture position and the small aperture position of the rotor magnet
It is possible to control the movement in one of the two positions.
However, when the drive coil is de-energized
In addition, the light amount variable member is attached by the detent torque.
Open throttle position that is positioned by the stopper by force
It is characterized in that it is positioned and held at the fixed position or small aperture position.
It is a light quantity adjusting device .

The present invention also provides, as the ferromagnetic material,
Note that there are two positions, the open aperture position and the small aperture position.
In each case, between the N pole of the rotor magnet
Ferromagnetic material on which detent torque acts and the rotor mug
The strength of the detent torque acting between the S magnetic pole of the net
Magnetic material is provided on both sides of the rotor magnet
It is characterized by being

[0017]

The present invention also provides the rotor magnet.
Is set to the open aperture position and the front by applying a positive or negative pulsed signal from the aperture control means to the drive coil.
It is characterized in that it moves in one of two positions of the small aperture position .

[0019]

Further , according to the present invention, the open stop position and the
The transmission means is at the two positions of the small aperture position.
It is characterized in that it is brought into contact with and positioned at the position .

[0021]

According to the present invention, the magnetic unstable point is
Wherein set in the open aperture position side <br/> the driving range of the rotor magnet, wherein the Turkey.

[0023]

Further, the present invention, the ferromagnetic material, the open angle of the magnetic pole of the Ru is paired directed disposed on the rotor magnet 90 degrees
Stays with two large ones and two smaller than 90 degrees
It is characterized by being a tayoke . Further, the present invention is
The rotor magnet is rotatably supported on the main plate,
The transmission member as the transmission means is the rotor magnet.
Is provided at the end of the transmission member,
It is characterized by driving . The present invention also provides the above-mentioned strong magnetic
The drive coil wound on the coil bobbin is attached to the elastic material.
And two magnets arranged to face the rotor magnet.
A stator yoke having poles formed thereon,
The two magnetic poles of the
Two positions, the open throttle position and the small throttle position
Generates a detent torque that applies a biasing force in the opposite direction
It is characterized by In addition, the present invention allows the aperture opening to pass through.
Aperture according to the light intensity detected by the light intensity detector
How to energize the drive coil of the diaphragm control means for determining the value
The rotor magnet opens depending on the direction switching.
That in the two position directions, the free-throttle position and the small stop position
It is characterized by moving to each. Further, the present invention is
The rotor magnet and the transmission means are integrally formed.
It is characterized by

[0025]

The present invention also provides an optical apparatus characterized in that the light quantity adjusting device having the above-mentioned construction is used to adjust the quantity of light to the image plane.

[0027]

DETAILED DESCRIPTION OF THE INVENTION

(First Embodiment) FIG. 1 is a control block diagram that best represents the features of the present invention. In FIG. 1, 20 is a drive source 2.
It is a light amount variable member that is driven by 1 and determines a diaphragm aperture for adjusting the passing light amount Ps.

Reference numeral 21 is a drive pulse Vc for the diaphragm control means 22.
A driving source for driving the light amount variable member according to the reference numeral 22 is a luminance signal Ys of the light amount detecting device 25 and data D1.
A desired aperture opening is determined by receiving D4 (or the data D3 of the operating portion), a drive pulse Vc for driving the drive source 21 corresponding to this aperture opening is output, and the determined aperture opening data D4 is stored in the memory 23. It is a diaphragm control unit that is configured to include a drive circuit 40 and a control circuit 41.

Reference numeral 23 denotes a memory for storing a preset aperture opening and control data D1 corresponding to the preset aperture opening and for storing the current aperture opening data D4. Reference numeral 24 denotes data for manually instructing the aperture opening by a switch. D
3 is an operation unit that outputs 3. Reference numeral 25 is a light amount detection device which is a CCD that detects the passing light amount Ps and outputs a luminance signal Ys, and 40 is a drive that receives drive pulse data D2 from the control circuit 41 and outputs a drive pulse Vc for driving the drive source 21. Circuit. Reference numeral 41 denotes drive pulse data determined from the luminance signal Ys of the light amount detecting device 25, the current aperture aperture data D4 of the memory 23, the preset aperture aperture and the corresponding control data D1 (or by the data D3 of the operation unit 24). This is a control circuit that outputs D2 to the drive circuit 40 and stores the newly determined diaphragm aperture data D4 in the memory 23 (hereinafter, the same portions will be denoted by the same reference numerals, and overlapping description will be omitted).

FIG. 2 is a diagram showing the drive circuit of the block diagram of FIG.

In the figure, reference numeral 1 is a drive coil (resistance value Rc) for rotationally driving the rotor magnet 2 by a pulse current Ic which is supplied with a drive pulse voltage Vc of the drive circuit 40 of the aperture control means 22 and 2 is driven. A rotor magnet for driving the light amount variable member 20 in accordance with the pulse current Ic that the coil energizes, and 21 is a drive source including the drive coil 1 and the rotor magnet 2.

40 is a PNP type transistor 50/51, an NPN type transistor 52/53, and an inverting buffer circuit 5.
It is a drive circuit composed of 4 ・ 55 switching circuits.
The applied voltage Va-G by the binary (H: High, L: Low) signal of D2-1 and D2-2 of the drive pulse data D2.
This is a drive circuit that switches ND to apply positive / negative (and zero) drive pulses Vc to the drive coil 1 of the drive source 21.

50 is OFF at H / L of the output of D2-1.
PNP transistor that turns on, 51 is a PNP transistor that turns off and on with the output H / L of the inverting buffer circuit 55, and 52 has H / L on the output of D2-2 that turns on / of
An NPN transistor for F, 53 is an NPN transistor for turning on / off by H / L of the output of the inverting buffer circuit 54, 54 is an inverting buffer circuit for inverting the output of D2-1 and outputting it to the NPN transistor 53, and 55 is D-2
Is an inverting buffer circuit which inverts the output of the above and outputs it to the PNP transistor 51.

FIG. 3 is a block diagram of a camera equipped with the light quantity adjusting device of this embodiment.

A is a light amount variable member 20, a driving source 21, a light amount detecting device 25, a focus motor 28, and a zoom motor 3.
1 and a lens unit composed of a lens group including a focus lens 29 and a zoom lens 32, B is an aperture control unit 22, a memory 23, an operation unit 24, a video signal processing circuit 26, an autofocus control unit 27, and a zoom motor control unit 30. It is a camera control circuit section composed of and.

Reference numeral 20 is a light amount variable member for determining the aperture opening composed of the light amount variable members 6 and 7, and reference numeral 24 is a manual operation of a switch to externally indicate an aperture value (aperture aperture) as well as an enlargement ratio and a focus movement. Operation unit that outputs the data to be
Reference numeral 26 is a video signal processing circuit for outputting a video signal from the luminance signal Ys of the light amount detecting device 25, and 27 is a light amount detecting device 25.
Luminance signal Ys, control of the memory 23, current aperture value (aperture aperture) data, and information of the zoom motor control unit (or according to the output signal of the operation unit 24) to drive the autofocus motor 28 to focus the object. It is an autofocus control unit for matching.

28 is an autofocus motor for driving the focus lens 29 in accordance with the output signal of the autofocus control unit 27, 29 is a focus lens for matching the focus of the object on the light amount detecting device 25, 30
Is a zoom motor control unit for driving the zoom motor 31 from the output signal of the operation unit 24 and the data of the memory 23 to change the enlargement ratio of the image, and 31 is the zoom motor control unit 3.
A zoom motor for driving the zoom lens 32 in accordance with an output signal of 0, a zoom lens 32 for varying the magnification ratio of an image on the light amount detection device, and a subject 33.

FIG. 4 is an exploded perspective view of the light quantity adjusting device of this embodiment, and FIG. 5 is a plan view of this embodiment.

Reference numeral 1 is a drive coil wound around a coil bobbin 1a and mounted on a stator yoke 3-1. Reference numeral 2 is mounted on a rotary shaft 9c of a transmission member 9 and a stator yoke 3-.
It is a rotor magnet magnetized with two poles in the radial direction and rotatably arranged with a gap in a circumferential portion formed at the tip of 1.3-2.

3-1 is a magnetic pole 3a in which a drive coil is wound, and a notch 3c having an opening angle of more than 90 degrees is provided in a circumferential portion opposed to the rotor magnet 2 with a gap. Stator yoke made of formed ferromagnetic material, 3
-2 is connected to the stator yoke 3-1, stator opening angle in the circumferential portion which is oppositely arranged with a rotor magnet 2 and the gap is made of a ferromagnetic material pole 3b is formed is smaller than 90 degrees In the yoke, both stator yokes 3-1, 3
-2 configures a magnetic circuit with the rotor magnet 2 and sets a magnetic instability point near the open aperture value position within the drive range to set a load due to detent torque.

Reference numeral 4 denotes an opening 4a for allowing the amount of light to pass therethrough, and a bearing 4b for pivotally supporting one of the rotating shafts 9c of the transmission member 9.
A stopper 4c that abuts on the periphery of the drive pin 9b of the transmission member 9 and a stopper 4d that abuts on the periphery of the drive pin 9a of the transmission member 9, which are base plates for supporting and locking each member. . Reference numeral 5 is a cap for the other bearing of the rotary shaft 9c of the transmission member 9.

Reference numeral 6 denotes a light amount varying member for adjusting the amount of light passing therethrough, having a slit 6a for fitting with the drive pin 9a of the transmitting member 9 to transmit the driving force from the transmitting member.
Is a light amount variable member for engaging with the drive pin 9b of the transmission member 9 and having a slit 7a for transmitting the driving force from the transmission member, and for adjusting the amount of light passing therethrough.

Reference numeral 8 is a diaphragm case having an opening 8a for allowing the light amount to pass therethrough and supporting the light amount variable members 6 and 7.

Reference numeral 9 denotes a drive pin 9a which fits into the slit 6a of the light quantity varying member 6, a drive pin 9b which fits into the slit 7a of the light quantity varying member 7, and a rotary shaft 9c into which the rotor magnet 2 is press fitted. The transmission means for transmitting the drive torque of the rotor magnet 2 to the light amount variable members 6 and 7, and the drive pins 9b and 9 to the stoppers 4c and 4d of the main plate 4.
The peripheral part of a comes into contact and functions as a restriction means for restricting the drive range of the rotor magnet 2 and the movement range of the light amount variable members 6 and 7.

Reference numeral 10 denotes a printed circuit board on which the terminals of the drive coil 1 are soldered to receive the drive pulse Vc of the diaphragm control means 22, and 11 is an optical axis of the passing light amount. here,
The drive source 21 includes a drive coil 1, a rotor magnet 2, and stator yokes 3-1 and 3-2.

In the present embodiment, the light amount variable members 6 and 7 have aperture openings corresponding to open apertures and small apertures set within the drive range.

FIG. 6 is a model diagram of the one-phase excitation motor of this embodiment.

Θ a is an opening angle of the magnetic pole 3 a of the stator yoke 3-1 that is larger than 90 degrees, θ b is an opening angle that is smaller than 90 degrees of the magnetic pole 3 b of the stator yoke 3-2, and θ c is of the rotor magnet 2. This is the drive regulation range at the N pole position.

Reference numeral 60 is a restriction position of the open diaphragm at the N pole position of the rotor magnet 2, and 61 is a restriction position of the small diaphragm at the N pole position of the rotor magnet 2. Rotor magnet 2
Is a magnetic pole polarity position of the magnetized magnetic pole, and x is a magnetic stable point at the N pole position of the rotor magnet 2 between the rotor magnet 2 and the stator yokes 3-1 and 3-2. ○
Indicates a magnetically unstable point at the N pole position of the rotor magnet 2, and the arrow between XX marks the rotor magnet 2 and the stator yokes 3-1, 3 at the angular position of the N (or S) magnetic pole of the rotor magnet 2. The direction of the detent torque (rotational force at which the rotor magnet tries to stop at the stable position) acting between the −2 magnetic poles is the direction, and + is the counterclockwise direction.

FIG. 7 is a graph of the detent torque magnetic instability of this embodiment and the detent torque at the aperture opening set at the two restricting positions of the restricting means. The + direction of the torque is counterclockwise in FIG. The rotational force in the direction indicates that the detent torque acts so as to move away from the magnetic instability point.

In FIG. 7, the cutout portion 3c shown in FIG.
Of the magnetic poles 3a having an opening angle greater than 90 degrees and the magnetic poles 3b having an opening angle smaller than 90 degrees.
Then, a magnetic instability point (0) is set near the aperture opening position in the drive range so that the magnetic instability (0) is reversed so as to be repulsed by the detent torque generated between the rotor magnets 2 magnetized in the radial direction with two poles and becomes zero torque. It shows the situation.

Here, one of the open stop restriction positions 60 (stopper 4d and drive pin 9a) is controlled by the drive range restriction means.
The regulation by the peripheral portion is set to the aperture opening position which is the aperture value of F2, and the regulation position 61 (stopper 4c) of the other small aperture is set.
And regulation by the peripheral portion of the drive pin 9b) are set to the aperture opening position which is the aperture value of F22, and the detent torque acts so as to bias in the respective regulation position directions.

In particular, since the magnetically unstable point (0) is set near the aperture opening position in the drive range, the detent torque toward the small aperture is large.

FIG. 8 is a timing chart of the control signal waveform of this embodiment. When both D2-1 and D2-2 of the drive pulse data D2 of the control circuit 41 become L, the energizing pulse current Ic of the drive coil 1 is shown. Is energized to a negative level, the diaphragm aperture at the restricting position 61 moves to F22, which is a small diaphragm, and when D2-1 is H and D2-2 is L, the energizing pulse current Ic of the drive coil 1 is zero (nothing). However, it is held at the regulation position 61 by the detent torque (negative one pulse operation).

Similarly, when both D2-1 and D2-2 become H, the energizing pulse current Ic of the drive coil 1 is energized to a positive level, and the diaphragm opening at the regulation position 60 is the open diaphragm F.
Move to 2, D2-1 goes high and D2-2 goes low,
The energizing pulse current Ic of the drive coil 1 is zero (non-energizing), but operates so as to be held at the regulation position 60 by the detent torque (one positive pulse operation, other D2-1.
The combination of D2-2 is prohibited. ).

In the above structure, the image pickup light from the subject 33 is the lens group of the lens unit A and the 6/7 light amount variable member 20.
After passing through the aperture opening, the image is formed on the light amount detection device 25. In the light quantity detection device 25, the luminance signal Y is calculated according to the light quantity of the imaging light.
s is output to the aperture control unit 22, the video signal processing circuit 26, and the autofocus control unit 27.

The control circuit 41 of the aperture control means 22 receives the luminance signal Ys proportional to the above-mentioned amount of passing light, compares the appropriate exposure amount with the luminance signal Ys, and compares the difference between the appropriate exposure amount and the current aperture value of the memory 23 (aperture value). A desired aperture value (aperture aperture) is determined from the aperture data D4, the preset aperture value (aperture aperture) and the corresponding control data D1 in the memory 23, and the drive pulse Vc is output. The drive pulse data D2 is output to the drive circuit 40 of the diaphragm control means 22.

When both D2-1 and D2-2 of the drive pulse data D2 become L in response to the drive pulse data D2, the transistors 50 and 52 are turned on and the transistor 51 is turned on.
53 is turned off, the negative drive pulse Vc is applied to the drive coil 1 of the drive source 21, and the negative drive pulse current Ic
When D2-1 is H and D2-2 is L, the transistors 50, 51, 52 and 53 are OFF, no voltage is applied to the drive coil 1, and the drive pulse current Ic is non-energized. That is, one negative pulse is supplied to the drive coil 1.

Similarly, when D2-1 and D2-2 both become H, the transistors 51 and 53 are turned on, the transistors 50 and 52 are turned off, and a positive drive pulse Vc is applied to the drive coil 1 to make it positive. When the drive pulse current Ic is supplied and D2-1 is H and D2-2 is L, the transistors 50, 51, 52 and 53 are turned off, no voltage is applied to the drive coil 1, and the drive pulse current Ic Is non-energized, and one positive pulse is energized to the drive coil 1.

When the driving coil 1 (resistance: Rc) is supplied with a negative pulse current Ic for generating a sufficient driving torque to overcome the detent torque, the rotor magnet 2 of the driving source 21 is rotationally driven in the small aperture direction. And stops at the regulation position 61, and the light amount variable member 20 is transmitted through the transmission member 9.
After driving (6 · 7) to drive and determine the aperture corresponding to F22, the drive coil 1 is de-energized, but is held at the detent torque.

Similarly, when a positive pulse current Ic for generating a sufficient driving torque to overcome the detent torque is applied to the driving coil 1, the rotor magnet 2 is rotationally driven in the direction of the open diaphragm and stopped at the regulating position 60. Then, after the light amount variable member 20 (6, 7) is driven and moved through the transmission member 9 to determine the diaphragm aperture corresponding to F2, the drive coil 1 is in the non-energized state but is held by the detent torque. It

Therefore, when a positive / negative binary one-pulse current Ic sufficient for driving is applied to the drive coil 1, the rotor magnet 2 is stopped at a position corresponding to each aperture value and the light amount variable member 20 is stopped. Position and hold (6, 7).

The light amount variable member 20 (6, 7) positioned at the position corresponding to each aperture value determines the aperture opening corresponding to the aperture value.

As a result, the light amount variable member 20 (6, 7) driven and moved by the drive torque of the drive source 21 determines the aperture and changes the light amount of the imaging light passing through the lens group of the lens unit A. The amount of image formation light of the light amount detection device 25 is adjusted to an appropriate amount of exposure.

When the dial is turned and the aperture value is set in the operation section 24, the aperture control means 22 operates the drive coil 1 in accordance with the setting information D3 from the operation section 24 as described above.
A drive pulse Vc that determines a positive / negative binary pulse current Ic is output to the drive source 21, and the drive source 21 is driven to move the light amount variable member 20 (6, 7) to obtain a desired aperture. Get the aperture (aperture value).

In the autofocus control section, the luminance signal Y
The focus shift is detected from s and the autofocus motor 2
8 is driven to slightly move the focus lens 29 back and forth to determine the moving direction, preset drive control information and aperture value data D4 at this time are retrieved from the memory 23, and the autofocus motor 28 is driven. The focus lens 29 is moved to perform the focus operation, and the focus of the image formation on the light amount detection device 25 is matched.

When the zoom switch is pressed on the operation section 24, the zoom motor control section 30 drives the zoom motor 31 in accordance with a signal from the operation section 24 to move the zoom lens 32 to change the magnification of image pickup.

At this time, zoom operation information is sent from the zoom motor control section 30 to the autofocus control section 27, and the autofocus control section 27 uses the drive information set in the memory 23 so that the focus is not shifted during the zoom operation. Based on this, the autofocus motor 28 is driven to move the focus lens 29 to perform the focus operation.

When the focus dial is turned by the operation section 24, the autofocus control section 27 drives the autofocus motor 28 according to the signal from the operation section 24 to move the focus lens 29 to change the focus.

The video signal processing circuit converts the luminance signal Ys output according to the image pickup light adjusted as described above into a video signal and outputs it.

The regulating position regulated by the regulating means of the transmission member 9 is within a rotation range of the rotor magnet 2 of 180 degrees or less, preferably 60 degrees.

In each of the present embodiments, the light amount detecting device 25 is an optical sensor such as a solar cell or a photoresistance change element, the rotor magnet 2 and the transmission member 9 are integrally molded, and the stator yoke 3-1. 3-2 may be made integral.

[0073]

[0074] In the present embodiment, since the set of magnetic instability point in the vicinity of the opening position, the detent torque is strong for the small aperture position direction, it and the speed of the small aperture position direction Speed
It

(Second Embodiment) In the second embodiment, the magnetic poles 3a and 3b in the stator yoke of the first embodiment are used.
In the example in which only the size of the open angle is changed and a magnetically unstable point is similarly provided in the drive range, the other parts are common.

FIG. 9 shows a model diagram of the one-phase excitation motor of the second embodiment.

Θ d is the magnetic pole 73 of the stator yoke 73-1
The opening angle smaller than 90 degrees of a, θ e is the stator yoke 73
An open angle smaller than 90 degrees of the magnetic pole 73b of −2, θ f is a drive regulation range at the N pole position of the rotor magnet 2.

Reference numeral 70 is a restriction position of the open aperture at the N pole position of the rotor magnet 2, and 71 is a restriction position of the small aperture at the N pole position of the rotor magnet 2.

[0079] N-S of the rotor magnet 2 pole polarity position of the magnetizing magnetic poles, × magnetically stable point at the N-pole position of the rotor magnet 2 between -2 rotor magnet 2 and the stator yoke 73-1 · 73, A circle indicates a magnetically unstable point at the N pole position of the rotor magnet 2.

The arrow between the circles is the N of the rotor magnet 2.
(Or S) The direction of the detent torque (rotational force at which the rotor magnet tries to stop at the stable position) acting between the magnetic poles of the rotor magnet 2 and the stator yokes 73 −1 and 73 −2 at that angular position of the magnetic pole, + is the opposite Clockwise direction.

FIG. 10 is a graph of the detent torque at the diaphragm aperture set at the two magnetically unstable points of the detent torque and the restriction means of the restriction means of the second embodiment. The arrow indicates that the detent torque acts so as to move away from the magnetically unstable point by the rotational force in the clockwise direction.

In FIG. 10, the magnetic poles 73a and 73 of FIG.
Both b are such that the detent torque generated between the stator yokes 73-1 and 73-2 whose opening angles of the magnetic poles are smaller than 90 degrees and the rotor magnet 2 magnetized to have two poles in the radial direction repels each other. The figure shows that the magnetically unstable point (0) at which the torque is inverted to zero torque is set near the intermediate aperture opening position in the drive range.

Other operations are similar to those of the first embodiment.

[0084] In this embodiment, it is possible to provide a magnetic instability point in the driving range pole simpler stator yokes.

[0085]

As described above, according to the present invention ,
Without energizing the drive source at the open throttle position and the small aperture position
The light quantity variable member can be positioned and held with high accuracy, saving power.
A highly accurate device can be easily realized.

[0086]

[0087]

According to the sixth invention of the present application, the magnetically unstable point can be easily set in the drive range with a simple structure.

[Brief description of drawings]

FIG. 1 is a control block diagram according to a first embodiment of the present invention.

FIG. 2 is a control drive circuit diagram of the first embodiment of the present invention.

FIG. 3 is a block diagram of a camera equipped with the light amount adjusting device according to the first embodiment of the present invention.

FIG. 4 is an exploded perspective view of the first embodiment of the present invention.

FIG. 5 is a plan view of the first embodiment of the present invention.

FIG. 6 is a model diagram of a one-phase excitation motor according to the first embodiment of the present invention.

FIG. 7 is a graph of detent torque in the aperture opening of the first embodiment of the present invention.

FIG. 8 is a timing chart diagram of control signal waveforms according to the first embodiment of the present invention.

FIG. 9 is a model diagram of a one-phase excitation motor according to a second embodiment of the present invention.

FIG. 10 is a graph of detent torque in the aperture opening of the second embodiment of the present invention.

[Explanation of symbols]

1 ... Drive coil 2 ... Rotor magnet 3-1, 3-2 ... Stator yoke 9 ... Transmission member 6, 7 ... Light amount variable member 22 ... Aperture control means 21 ... Drive source

Continuation of the front page (56) Reference JP-A-4-283715 (JP, A) JP-A-7-319007 (JP, A) JP-A-6-186613 (JP, A) JP-A-3-231722 (JP , A) JP 59-115507 (JP, A) JP 2-173730 (JP, A) JP 7-181554 (JP, A) JP 4-291331 (JP, A) JP 3-251071 (JP, A) JP 7-159849 (JP, A) JP 7-181557 (JP, A) JP 7-234434 (JP, A) JP 7-319005 (JP, A) JP 7-319006 (JP, A) JP 7-211529 (JP, A) JP 9-222627 (JP, A) JP 9-244100 (JP, A) JP 9 -325382 (JP, A) JP-A 1-280738 (JP, A) JP-A 1-101525 (JP, A) JP-A 64-59224 (JP, A) JP-A 52-37428 (JP, A) ) JP-A-2002-116478 (JP, A) Actual flat 3-29837 (JP, U) Actual flat 6-37834 ( P, U) JitsuHiraku Akira 60-63827 (JP, U) Tokuoyake Akira 62-6440 (JP, B2) (58 ) investigated the field (Int.Cl. ^7, DB name) G03B 9/04

Claims (11)

(57) [Claims] 1. A diaphragm aperture for varying the amount of light is determined.
A light quantity variable member that, by the rotor magnet and a drive coil comprising a permanent magnet
A driving source for driving the light amount varying member constructed and transmission means for transmitting the driving force of the driving source to the light quantity variable member, with openings through which light passes is formed, the amount of light allowed
Position the variable member in two positions, the open throttle position and the small throttle position.
Set the drive range of the rotor magnet to the position
Rotation range of 180 degrees or less between two determined positions
And the ground plane having a stopper for restricting the, disposed with a gap relative to the rotor magnet,
Magnetic instability in the drive range of the rotor magnet
The magnetic instability of the rotor magnet is provided by providing points.
Direction of the two positions that are positioned away from the point
A strong force that generates a detent torque that applies a biasing force to
A magnetic material, and by switching the energizing direction to the drive coil,
2 of the open stop position and the small stop position of the magnet
It is possible to control the movement of any of the locations in any position direction, and when the drive coil is de-energized,
The light amount variable member is biased by the detent torque.
To the open throttle position which is positioned by the stopper.
Or a light quantity adjusting device characterized by positioning and holding at a small aperture position . 2. The open stop position as the ferromagnetic material
And at each of the two positions of the small aperture position,
Detent torque between the N pole of the rotor magnet
Ferromagnetic material acting on the magnet and the S magnetic pole of the rotor magnet
The ferromagnetic material on which detent torque acts between
Characterized by being provided on both sides of the rotor magnet
The light amount adjusting device according to claim 1 . 3. The rotor magnet is diaphragm control means.
Positive or negative pulsed signal from the source to the drive coil
2 of the open throttle position and the small throttle position by energizing
Characterized by moving in one of the two positions
The light amount adjusting device according to claim 1 . 4. The open stop position and the small stop position
The transmission means comes into contact with the stopper at several positions.
4. The arrangement according to claim 1, wherein the arrangement is performed.
The light quantity adjusting device as described in 1 above . 5. The magnetically unstable point is the rotor magnet.
<br/> light amount adjusting device according to claim 1, any one of 4 to the set to the open aperture position side, wherein the Turkey <br/> driving range net. Wherein said ferromagnetic material is the open angle of the magnetic pole of the Ru is paired directed disposed rotor magnet and those of larger than 90 degrees
It is a stator yoke provided with two ones smaller than 90 degrees, and any one of claims 1 to 5 characterized by the above-mentioned.
Light amount adjustment device. 7. The rotor magnet rotates on the main plate
And a transmission member as the transmission means is rotatably supported.
It is provided on the rotor magnet and is
2. The light amount varying member is driven, according to claim 1.
7. The light amount adjusting device according to any one of 6 to 6 . 8. The ferromagnetic material is wound on a coil bobbin.
The drive coil is attached to the rotor magnet.
A stator yoke having two magnetic poles facing each other
And The two magnetic poles of the stator yoke are respectively
2 of the open aperture position and the small aperture position on the magnet.
A detent tor that exerts a biasing force in the direction of various positions
8. Any one of claims 1 to 7, characterized in that
The light amount adjusting device according to any one of the above. 9. After passing through the aperture,
Aperture control that determines the aperture value according to the detected light intensity
According to the switching of the energizing direction to the drive coil of the means
The rotor magnet to the open throttle position and the small
Move to each of the two positions of the diaphragm position
The light according to any one of claims 1 to 8, characterized in that
Quantity adjustment device. 10. The rotor magnet and the transmission means
Are integrally molded.
The light amount adjusting device according to any one of 1. 11. An optical apparatus, characterized in that adjusting the amount of light to the image plane with the light amount adjusting device according to any one of claims 1 10.