JPH09211529A - Light quantity adjusting device and optical element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain desired stop aperture with a simple constitution and simple control driving by providing a light quantity adjusting device with a stop aperture set means by which load balanced with driving force occurring in accordance with a driving signal for energizing a driving source is provided and stepwise desired stop aperture can be obtained. SOLUTION: A scene varying member 20 is driven by a driving source 21, and decides the stop aperture for adjusting passing light quantity Ps. The source 21 drives the member 20 to a position balanced with a set load Te in accordance with the driving voltage Vc of a diaphragm control means 22. The means 22 constituted of a driving circuit 40, a control circuit 41, and a driving signal switching circuit 42, decides a desired stop aperture by receiving the luminance signal Ys of a light quantity detector 25 and the data D1 and D4 of a memory 23, outputs the driving voltage Vc corresponding to the stop aperture and driving the source 21 and also makes the memory 23 store the decided stop aperture data D4.

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, a light amount adjusting device of this type has a spring in which a diaphragm plate provided with a plurality of diaphragm openings is wound up manually or by a motor as described in Japanese Patent Laid-Open No. 63-118728. It is configured to switch the aperture opening by charging with the electric power and driving the locking claw that engages with the locking portion provided on the diaphragm plate with the electromagnet and the spring.

Further, the position of the diaphragm plate is detected, and the diaphragm motor is driven by a servomotor which feeds back the detection result to control the diaphragm plate to switch the diaphragm aperture.

Alternatively, as described in Japanese Patent Application Laid-Open No. 1-101525, a stepping motor is used to drive an aperture opening / closing ring and the aperture blades switch the aperture opening.

In addition, there is known one which is configured to switch the aperture opening by a reciprocating motion of an electromagnet and a spring or the like.

[0006]

However, in the above-mentioned conventional example, the winding and locking claw mechanism, the servo motor, the stepping motor, the electromagnet, etc. are used for switching and positioning of the aperture opening. There was a flaw.

1) In the spring winding mechanism and the locking claw mechanism, the servo motor, the stepping motor, etc., the mechanism is complicated, the device becomes large and heavy, the assemblability deteriorates, and the failure rate increases.

(2) In servomotors, stepping motors, etc., the control methods such as negative feedback control and drive pulse train shaping are complicated and difficult, and the control drive circuit becomes large in scale.
There is concern about malfunctions such as mistaken steps or abnormal noise.

(3) With only a reciprocating drive device such as an electromagnet,
Only two apertures are available.

An object of the first invention according to the present application is to obtain a desired diaphragm aperture with a simple control drive having a simple structure.

A second object of the present invention is to arbitrarily set a desired diaphragm aperture.

A third object of the present invention is to make the current levels applied to the aperture and the drive coil correspond one-to-one in one driving direction.

A fourth object of the present invention is to position a desired diaphragm aperture with high accuracy.

A fifth object of the present invention is to make it possible to set a load corresponding to the aperture of the diaphragm with a minimum required simple structure.

A sixth object of the present invention is to provide a diaphragm opening position corresponding to a zero level of a current passing through a drive coil between control position limits of a drive range.

A seventh object of the present invention is to set a load corresponding to a diaphragm opening with a minimum required simple structure without newly using dedicated parts.

An eighth object of the present invention is to set a load corresponding to an arbitrary number of diaphragm apertures at an arbitrary position.

A ninth object of the present invention is to set a load corresponding to a diaphragm aperture with a minimum necessary simple structure without newly using a dedicated part.

A tenth aspect of the present invention is to provide an optical apparatus such as a photographing device capable of easily adjusting the light amount in a plurality of stages by using the light amount adjusting device which realizes such an object.

[0020]

In order to achieve the above object, a first invention according to the present application provides a light quantity varying member for determining a diaphragm aperture for varying the light quantity, and the light quantity varying member. A light amount adjusting device comprising: a driving source for driving; a transmitting means for transmitting a driving force of the driving source to a light amount varying member; and a diaphragm control means for forming a drive signal for energizing the driving source, wherein the driving source A light quantity adjusting device is characterized in that a load that balances with a driving force generated according to a drive signal that is energized is provided and a diaphragm aperture setting unit that obtains a desired diaphragm aperture stepwise is provided.

The drive source is composed of a rotor magnet made of a permanent magnet, a stator yoke made of a ferromagnetic material arranged to face the rotor magnet so as to form an air gap, and a drive coil for exciting the stator yoke. The aperture control means is configured to vary the level of current supplied to the drive coil.

In the above structure, the aperture opening setting means is
For example, when the drive coil is energized with a predetermined current level, the drive source drives the light amount variable member to operate to position it at a desired diaphragm aperture position corresponding thereto.

The second invention is.

In the above structure, the load setting means sets each load at a desired aperture opening position, and the light amount varying member is set in accordance with each current level which is applied to the drive coil which becomes the driving force of the drive source balanced with this load. When the lens is driven, the light amount variable member stops at each position, and operates so as to position at the desired diaphragm aperture position corresponding to it.

In a third aspect of the invention, the aperture opening setting means is
A plurality of loads balanced with a plurality of driving forces of a driving source generated according to the driving signal are set in the respective desired aperture openings.

In the above arrangement, the aperture opening setting means is
A load that gradually increases or decreases is sequentially set at a desired aperture opening position, and according to each current level that is applied to the drive coil that is the driving force of the drive source balanced with this load,
When the light amount variable member is driven from one driving direction, the light amount variable member stops at each corresponding position, and operates so as to be positioned at a desired diaphragm aperture position corresponding thereto.

In a fourth aspect of the present invention, the aperture opening setting means has a relationship between a plurality of types of loads for setting a desired aperture corresponding to the sequential movement of the aperture opening position and loads due to a plurality of driving forces of the drive source. It is characterized in that it is set so as to sequentially increase or decrease in at least one driving direction.

In the above arrangement, the aperture opening setting means is
When a load that rapidly increases or decreases is set at a desired aperture opening position and the light amount variable member is driven in accordance with a wide range of current level that is applied to the drive coil that is the driving force of the drive source balanced with this load, the narrow position At this point, the light amount variable member stops and operates so as to position at the desired aperture opening position corresponding thereto.

A fifth aspect of the invention is characterized in that at least one of the loads set in a desired aperture opening is set by the detent torque generated between the rotor magnet and the stator yoke.

In the above arrangement, the aperture opening setting means is
For example, the light amount varying member is stopped at a position where the driving force of the drive source that drives the light amount varying member according to the current level for energizing the drive coil and the load due to the detent torque are balanced, and the light amount varying member is positioned at the corresponding desired aperture opening position. Operate.

The sixth invention is characterized in that the load set by the detent torque includes a magnetic stable point of the detent torque.

In the above arrangement, the aperture setting means has a detent torque of a zero load that balances the zero driving force of the driving source for driving the light amount variable member in response to the zero current level applied to the driving coil. The light amount variable member stops at the magnetically stable point position, in other words, the light amount variable member is driven / stopped to the magnetically stable point position by the detent torque, and operates so as to be positioned at the corresponding desired aperture opening position. .

A seventh aspect of the invention is characterized in that at least one of the loads set in a desired aperture opening is set by changing the transmission efficiency of the transmission means.

In the above structure, the aperture setting means remarkably reduces or increases the efficiency of transmitting the driving force of the drive source to the light amount variable member at the desired aperture opening position, sets the corresponding load, and balances this load. When the light amount variable member is driven in accordance with each current level that is the driving force of the drive source and is applied to the drive coil, for example, the light amount variable member stops at each position and operates so as to position at the corresponding desired aperture opening position. To do.

The eighth invention is characterized in that at least one of the loads set to a desired aperture opening is set by using the biasing force of the elastic member.

In the above structure, the opening setting means can set a load at an arbitrary position where the biasing force of the spring member, which is an elastic member, can be applied, and the drive coil which is the driving force of the drive source balanced with this load is energized. When the light amount varying member is driven in accordance with the respective current levels, the light amount varying member stops at each position and operates so as to be positioned at a desired diaphragm aperture position corresponding thereto.

The ninth invention is characterized in that at least one of the loads set to a desired aperture opening is set by using the sliding resistance of the light amount variable member.

In the above structure, the aperture setting means sets a corresponding load by significantly reducing or increasing the sliding resistance of the light amount variable member at a desired aperture opening position, and a driving force of a drive source balanced with this load. When the light amount variable member is driven in accordance with the respective current levels applied to the drive coil, the light amount variable member stops at each position, and operates so as to be positioned at the desired diaphragm aperture position corresponding thereto.

A tenth aspect of the present invention is an optical apparatus, characterized in that the above-mentioned light amount adjusting device is used to adjust the light amount to the image plane.

[0040]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) FIG. 1 is a control block diagram showing an embodiment of a light quantity adjusting device of the present invention.

In the figure, 20 is a light amount variable member driven by a drive source 21 and determines a diaphragm aperture for adjusting the passing light amount Ps, and 21 is a light amount variable member according to the drive voltage Vc of the diaphragm control means 22. It is a drive source that drives to a position balanced with the set load Tl.

22 receives the luminance signal Ys of the light amount detecting device 25 and the data D1 and D4 of the memory 23 (or the data D3 of the operating portion) to determine a desired diaphragm aperture, and the drive source 21 corresponding to this diaphragm aperture is determined. The diaphragm aperture data D4 determined while outputting the driving voltage Vc for driving is stored in the memory 23.
The aperture control means for storing the data in a drive circuit 40, a control circuit 41, and a drive signal switching circuit 42.

Reference numeral 23 is a memory for storing the preset aperture opening and the data D1 of the drive signal Va corresponding thereto and the current aperture opening data D4, 24
Is an operation unit that outputs data D3 instructing the aperture opening from the outside by manual operation of the switch.

Reference numeral 25 denotes a luminance signal Y by detecting the passing light amount Ps.
A light amount detection device, which is a CCD that outputs s, is a drive circuit that outputs a drive voltage Vc for driving the drive source 21 in response to the drive signal Va of the drive signal switching circuit 42.

Reference numeral 41 denotes a luminance signal Ys of the light amount detecting device 25, the current diaphragm aperture data D4 of the memory 23, a preset diaphragm aperture and data D1 of the drive signal Va corresponding thereto.
(Or data D3 of the operation unit 24) outputs the data D2 for switching the drive signal Va determined, and stores the newly determined diaphragm aperture data D4 in the memory 23, 42 is the data of the control circuit This is a drive signal switching circuit that receives the D2 and outputs the drive signal Va (hereinafter, the same portions are designated by the same reference numerals, and duplicate description will be omitted).

FIG. 2 shows a circuit diagram of the drive circuit 40 in the block diagram shown in FIG.

In the figure, reference numeral 1 is a drive coil (resistance value Rc) for rotationally driving the rotor magnet 2 by a current Ic supplied by the drive voltage Vc of the diaphragm control means 22,
Reference numeral 2 is a rotor magnet for driving the light amount variable member 20 in accordance with the current Ic passed through the drive coil, and reference numeral 21 is a drive source including the drive coil 1 and the rotor magnet 2.

Reference numeral 40 is a drive circuit including a voltage follower circuit 50 and an inverting circuit 51, 42 is a drive signal switching circuit including a D / A converter, and 50 is a drive signal switching circuit 4
A voltage follower circuit that receives the drive signal Va of No. 2 and voltage-buffers it and supplies it to one terminal of the drive coil 1. Reference numeral 51 inverts the output voltage of the voltage follower circuit 50 with respect to the reference voltage Vf. An inverting circuit that supplies the other terminal.

FIG. 3 is a block diagram of a video 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. And a camera control circuit section 20 including a light amount variable member 6/7.
A light amount variable member for determining a diaphragm aperture consisting of 12.

Reference numeral 24 designates an operation section for manually outputting the data to instruct the enlargement ratio and the focus movement in addition to the aperture value (aperture aperture) by the manual operation of the switch, and 26 designates the video signal from the luminance signal Ys of the light quantity detecting device 25. This is an output video signal processing circuit.

Reference numeral 27 represents the luminance signal Ys of the light amount detecting device 25, the control of the memory 23, the current aperture value (aperture aperture) data, and the information of the zoom motor control section (or the operation section 24).
Auto focus motor 28 according to the output signal of
Is an autofocus control unit for driving the camera to match the focus of the subject.

28 is an autofocus motor for driving a focus lens 29 in accordance with the output signal of the autofocus 27, and 29 is the light amount detecting device 2 for focusing the object.
5, a zoom lens controller 30 for driving the zoom motor 31 based on the output signal of the operation unit 24 and the data of the memory 23 to change the magnification ratio of the image, and a zoom motor control unit 31. A zoom motor for driving the zoom lens 32 according to the output signal of the unit 30, a zoom lens 32 for varying the magnification ratio of the 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.

Reference numeral 1 is a drive coil wound around a coil bobbin 1a and mounted on a stator yoke 3-1. Reference numeral 1a is a coil bobbin for winding the drive coil. Reference numeral 2 is mounted on a rotary shaft 9c of a transmission member 9 and is a stator. York 3-1
3-2 is a rotor magnet which is rotatably arranged with a hollow wall formed in the circumferential portion formed at the tip of the rotor magnet and which is magnetized with two poles in the radial direction. The stator yoke is made of a ferromagnetic material in which magnetic poles 3a having an opening angle of more than 90 degrees are formed in a circumferential portion which is arranged opposite to the rotor magnet 2 via a hollow wall.

3-2 is connected to the stator yoke 3-1 and is a strong magnetic pole 3b having an opening angle of more than 90 degrees formed on the circumferential portion opposed to the rotor magnet 2 via the hollow wall. In the stator yoke made of a magnetic material, the stator yoke 3-1 and the stator yoke 3-2 form a magnetic circuit with the rotor magnet 2, and the magnetic stable point is set to a desired (F8) aperture value which is a drive range. By doing so, the load due to the detent torque is set.

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.
And a stopper 4c that comes into contact with the peripheral portion of the drive pin 9b of the transmission member 9 and a stopper 4d that comes into contact with the peripheral portion of the drive pin 9a of the transmission member 9, and the base plate 5 for supporting and locking each member is provided. Is a cap for the other bearing of the rotary shaft 9c of the transmission member 9.

Reference numeral 6 has a slit 6a for fitting with the drive pin 9a of the transmitting member 9 to transmit the driving force from the transmitting member and a rough surface portion 6b having a significantly large friction coefficient, and adjusts the amount of light passing therethrough. The light amount varying member 6b is a rough surface portion having a remarkably large friction coefficient, which is a load setting means for sliding the light amount varying member 12 within the aperture value range of F16 to F22 to set the load.

Reference numeral 7 is a light quantity varying member for fitting 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 passing light. Reference numeral 8 denotes an aperture case which has an opening 8a for allowing the amount of light to pass therethrough and supports the light amount variable members 6, 7 and 12, and 9 is a drive pin 9a which fits into the slit 6a of the light amount variable member 6.
And the slit 7a of the light amount variable member 7 and the light amount variable member 1
2 has a drive pin 9b that fits into the slit 12a, a rotary shaft 9c into which the rotor magnet 2 is press-fitted, and an operating arm 13c of the spring member 13 and a spring operating pin 9d that abuts in the aperture range of F2 to F4. Rotor magnet 2
Is a transmitting member for transmitting the driving torque of the driving torque to the light amount varying members 6, 7, 12 and the peripheral portions of the driving pins 9b, 9a contact the stoppers 4c, 4d of the main plate 4 so that the driving range and the light amount of the rotor magnet 2 can be changed. It has a function as a regulation means for regulating the movement range of the members 6, 7, and 12.

Reference numeral 10 is a printed circuit board on which the terminals of the drive coil 1 are soldered to receive the drive voltage Vc of the diaphragm control means 22, and 11 is an optical axis of the amount of passing light.

Reference numeral 12 is a light amount variable member for adjusting the amount of light passing therethrough, and has an L-shaped slit 12a that fits with the drive pin 9b of the transmission member 9, and this fitting relationship is F11.
The load can be set by changing the transmission efficiency from 0 to nearly 100% so that the contact is made in the aperture value range of to F22 and not to be made in the range of F2 to F11.

Reference numeral 13 denotes a spring member which is an elastic member, and has a coil inner diameter 13a for supporting it, a fixed arm 13b for fixing one end thereof, a spring operating pin 9d, and abutting in the aperture value range of F2 to F4. It has an operating arm 13c that operates together while being energized, and energizes the transmission member in the aperture value range of F2 to F4 to set the load.

Here, the drive source 21 is composed of a drive coil 1, a rotor magnet 2, and stator yokes 3-1 and 3-2.

In the present embodiment having the above-mentioned structure, the light amount variable members 6, 7, 12 are used to control F2, F4, F8, F1.
Six stages of aperture openings corresponding to 1 · F16 · F22 are sequentially set within the drive range.

FIG. 5 shows a plan view of the light quantity adjusting device of FIG.

In FIG. 5, the base plate 4 is provided with a spring member fixing pin 4e for mounting and fixing the fixing arm 13b of the spring member 13 and a coil inner diameter 13a for supporting the spring member 13 for supporting. Spring member support pin 4f and a spring member biasing holding pin 4g for holding the actuating arm 13c of the spring member 13 in a charged state so as to be operable in a range limited to the aperture value range of F2 to F4. .

FIG. 6 is a model diagram of the one-phase excitation motor of the present embodiment. Θa is an opening angle larger than 90 degrees of the magnetic pole 3a of the stator yoke 3-1 and Θb is the magnetic pole 3b of the stator yoke 3-2. The opening angle Θc, which is larger than 90 degrees, is the drive regulation range at the N pole position of the rotor magnet 2.

Reference numeral 60 is a restriction position of the open diaphragm at the N pole position of the rotor magnet 2, 61 is a restriction position of the small diaphragm at the N pole position of the rotor magnet 2, and N.
S indicates the magnetic pole polarity position of the magnetized magnetic pole.

X indicates a magnetically 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, and O indicates a magnetically unstable point at the N pole position of the rotor magnet 2. Show.

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 3-1 and 3-2 at that angular position of the magnetic pole, + is the opposite Clockwise direction.

FIG. 7 is a graph of the set load torque at the aperture of each means of this embodiment, and the + direction of the torque is the rotational force in the counterclockwise direction in FIG.

(A) is a graph showing the detent torque in the aperture opening where the load is set by the detent torque of the present embodiment, and the stator yoke 3-1 in which the open angle of the magnetic poles 3a and 3b in FIG. 6 is larger than 90 degrees.・ Set the magnetic stable point (×), which is the zero torque of the detent torque generated between 3-2 and the rotor magnet 2 magnetized with two poles in the radial direction, at the aperture opening position which is the aperture value of F8. However, in other regions, the detent torque acts to bias the rotor magnet 2 to the magnetically stable point.

(B) is a graph showing the load torque at the aperture opening where the load is set by the drive range regulating means of the present embodiment, and one open aperture regulating position 60 (stopper 4d and stopper 4d by the drive range regulating means). The load at the drive pin 9a peripheral portion) is set to the aperture opening position that is the aperture value of F2, and the load at the other small aperture control position 61 (restricted by the stopper 4c and the drive pin 9b peripheral portion) is set to F2.
It is set to the aperture opening position which is the aperture value of 2.

(C) is a graph showing the spring torque at the aperture opening in which the load is set by the urging force of the spring member which is the elastic member of this embodiment. The spring torque of the charged spring member 13 suddenly changes from F4 to F2. The load is set so as to be almost constantly urged in the small aperture direction up to the aperture opening position range which is the aperture value.

(D) is a graph showing the load torque at the aperture opening where the load is set by changing the transmission efficiency of this embodiment, and the L-shaped slit 12a and the drive pin are aperture values from F11 to F22. The load is set so that the drive force of the rotor magnet 2 is transmitted by contacting only up to the opening position range. Here, the arrow indicates the moving direction, and the polarity of the load torque is reversed depending on the moving direction.

(E) is a graph showing the load torque at the aperture opening where the load is set by the sliding resistance of the light amount variable member of the present embodiment, and the rough surface portion 6b and the light amount of the light amount variable member 6 having a significantly large friction coefficient. Variable member 12 is from F16 to F
The load is set so as to slide up to the aperture opening position range which is the aperture value of 22. The arrow indicates the direction of movement,
The polarity of the load torque is reversed depending on the moving direction.

FIG. 8 is a graph of the set load torque in the comprehensive aperture opening of the present embodiment, in which the respective loads shown in FIG. 7 are combined, the arrow indicates the moving direction, and the history of load torque varies depending on the moving direction. Seen.

That is, the load torque is set so as to rapidly increase or decrease with respect to each F value, and the load torque gradually increases in the moving direction from F2 to F22.

In particular, since the load torque from F8 to F22 has a history due to the engagement between the L-shaped slit 12a of the light quantity varying member 12 and the drive pin, the movement to the F value during this period requires moving from the F8 direction. There is.

FIG. 9 is a timing chart of the control signal waveform of the present embodiment. When the drive signal Va of the drive signal switching circuit changes from V1 to V6, the level of the current Ic supplied to the drive coil accordingly changes from I1 to I6. The aperture opening that changes to I6 and is set to the corresponding load torque is determined as the F value from F2 to F22.

In order to determine the aperture of F11 and F16, the drive is controlled so as to move sequentially from F8.

The inversion circuit 5 of the drive circuit 40 outputs the drive signal Va.
If it is made equal to the reference voltage Vf in 1, the energizing current Ic
Becomes a zero level (I3), the light amount control member 20 is driven and moved by the load torque, and the aperture of F8 is reached.

In the above structure, the image pickup light from the subject 33 is the lens group of the lens section A and the light amount variable member 20 (6.
It passes through the aperture opening of 7/12) and forms an image on the light amount detection device 25. In the light quantity detection device 25, the brightness signal Ys is adjusted according to the light quantity of the image pickup light to the aperture control means 22 and the video signal processing circuit 2.
6. Output to 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 passing light amount, 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). To determine the desired aperture value (aperture aperture) from the aperture data D4 and the preset aperture value (aperture aperture) of the memory 23 and the corresponding data D1 of the drive signal Va, and to switch the drive signal Va. And outputs the data D2 to the drive signal switching circuit 42 of the aperture control means 22.

In response to the digital data D2 indicating the drive signal Va, the D / A converter of the drive signal switching circuit 42 converts the digital data D2 into the analog drive signal Va to drive the aperture control means 22. Output to the circuit 40.

In response to the analog drive signal Va, the voltage follower circuit 50 of the drive circuit 40 buffers the drive signal Va and outputs it to one terminal of the drive coil 1 of the drive source 21 and at the same time, inverts the drive circuit 40. Output to the circuit 51.

In the inverting circuit 51, the voltage of one terminal of the drive coil 1 is inverted with respect to the reference voltage Vf and output to the other terminal of the drive coil 1 to drive the drive coil 1 of the drive source 21.
The positive and negative drive voltages Vc can be applied to both ends of the.

The drive coil 1 (resistance: Rc) to which the drive voltage Vc is applied has a current Ic according to the drive voltage Vc.
(Vc / Rc) is energized, and the rotor magnet 2 of the drive source 21 is rotationally driven with a drive torque according to the energized current Ic.

The rotor magnet 2 is driven by the light amount varying member 20 via the transmitting member 9 with a driving torque according to the energizing current Ic.
Drive (6, 7 and 12).

Here, the load torque against the drive torque corresponding to the current Ic of the drive source is set to each aperture value by each means shown in FIG. 7, and each load value is set to each aperture value as shown in FIG. The load torque that increases or decreases more rapidly than between the aperture values is set to sequentially increase in the moving direction of F2 → F22.

Therefore, when the drive torque balanced with the suddenly increasing or decreasing load torque set at each aperture value is applied, the rotor magnet 2 stops at the position corresponding to each aperture value and the light amount variable member 20 ( Position 6/7/12).

In particular, in order to position at the aperture value positions of F11 and F16, the drive torque is applied so as to move to the aperture value position of F8 (driving torque = 0) and then toward F22.

As to each signal of this control and the aperture opening position, as shown in FIG. 9, the drive torque corresponding to the current Ic applied to the drive coil 1 which is determined by the drive signal Va is set to each aperture value (each aperture value). It stops at each aperture value (each aperture opening) position in balance with the load set for the aperture.

That is, by determining the current Ic to be applied to the drive coil 1 which gives the drive torque balanced with the load torque set to each aperture value, the light amount variable member 20 (6. 7).
・ 12) can be positioned at each aperture value.

The light amount variable members 20 (6, 7 and 12) positioned at the positions corresponding to the respective aperture values determine the aperture opening corresponding to the aperture value.

As a result, the light amount variable member 20 (6, 7 and 12) driven and moved by the drive torque of the drive source 21.
Determines the diaphragm aperture to vary the light amount of the image pickup light passing through the lens group of the lens unit A, and adjusts the image formation light amount of the light amount detection device 25 to an appropriate exposure amount.

When the dial is turned by the operating section 24 to set the aperture value, the aperture control means 22 determines the current Ic to be applied to the drive coil 1 as described above according to the setting information D3 from the operating section 24. The driving voltage Vc is output to the driving source 21, and the driving source 21 is driven to drive the light amount variable member 20.
By moving (6, 7, 12), a desired diaphragm aperture (aperture value) is obtained.

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 unit 24 to set the enlargement ratio, the zoom motor control unit 30 drives the zoom motor 31 in accordance with a signal from the operation unit 24 to move the zoom lens 32, and image pickup is performed. Change the magnification.

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 stores the drive information set in the memory 23 so that the focus does not shift 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 to set the focus movement, the autofocus control section 27 drives the autofocus motor 28 in accordance with the signal from the operation section 24 to move the focus lens 29 to move the focus. Fluctuate.

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.

Further, the restricting position restricted by the restricting means of the transmitting member 9 is within a rotation range of the rotor magnet of 180 degrees or less, preferably 60 degrees.

The present invention is not limited to the above embodiment, the light amount detecting device 25 is an optical sensor such as a solar cell or a photo resistance change element, and an electric power such as an emitter follower is provided at the output stage of the drive circuit 40. Amplifier to which an amplifier circuit is added, Vf of the inversion circuit 51 of the drive circuit 40 is at ground potential (zero), and another terminal of the drive coil 1 is connected to the ground potential (zero) (inversion circuit 51 , The drive signal switching circuit 42 is a switch circuit such as a multiplexer, an analog switch, and a relay circuit, the rotor magnet 2 and the transmission member 9 are integrally molded, and the stator yokes 3-1 and 3-2 are driven. The coil 1 may be detachably integrated. (Second Embodiment) FIGS. 10 and 11 show a second embodiment.

The second embodiment is an embodiment in which the light amount variable member 12 is removed from the first embodiment and the load setting means by transmission efficiency and the load setting means by sliding friction resistance are not used. Is omitted, and only different points will be described.

FIG. 10 is a graph of the set load torque at the aperture opening representing the second embodiment.
The load torque due to the transmission efficiency shown in (a), the load torque due to the detent torque in (a) excluding the load torque due to sliding resistance shown in (e), (b) the load torque due to the control means of the drive range, and (c) 7 is a graph of a combination with a load torque due to the urging force of a spring member that is an elastic member.

For each F value, the load torque is set so as to increase or decrease rapidly, and the load torque gradually increases or decreases regardless of the moving direction. On the other hand, only one load corresponding to each other is set.

FIG. 11 is a timing chart drawing of a control signal waveform representing the second embodiment. When the drive signal Va of the drive signal switching circuit changes from V1 to V6, the current Ic to be supplied to the drive coil accordingly. Level is I
The aperture opening that changes from 1 to I6 and is set to the corresponding load torque is uniquely determined for each aperture value of F2 to F22.

In the above construction, it is not necessary to limit the moving direction as in the first embodiment, and the respective signals of this control and the state of the aperture opening are determined by the drive signal Va as shown in FIG. The drive torque corresponding to the current Ic flowing through the drive coil 1 is balanced with only one load set for each aperture value (each aperture opening) and each aperture value (each aperture opening).
Stop in position.

That is, by determining the current Ic to be applied to the drive coil 1 that gives the drive torque that balances the load torque set to each aperture value, the light amount variable member 20 (6.
7) can be positioned at only one position for each aperture value.

[0111]

As described above, the first embodiment according to the present application is described.
According to the invention, the stepwise desired aperture opening can be easily obtained only by switching the level of the drive signal to be supplied to the drive source.

According to the second invention of the present application, by setting the load with a high degree of freedom, it is possible to easily set a desired aperture opening at an arbitrary position where the load can be set.

According to the third invention of the present application, a desired diaphragm aperture can be easily obtained only by switching the current level applied to the drive coil from one driving direction.

According to the fourth invention of the present application, even if the driving force of the driving source varies according to the current level applied to the driving coil, the change in the load balanced with the driving force sharply increases. Alternatively, since it is reduced, it is possible to obtain a highly accurate light amount adjusting device in which an error such as a deviation from a desired aperture position is small.

According to the fifth invention of the present application, the load can be set with the minimum necessary configuration to obtain a desired aperture opening,
A simple device can be miniaturized.

According to the sixth invention of the present application, the magnetic stable point of the detent torque, which becomes the zero load corresponding to the zero driving force which can be easily realized and has a small error, is set to the desired aperture opening position. Since it is provided, it is possible to easily obtain a desired diaphragm opening with a small error.

According to the seventh invention of the present application, a desired aperture can be obtained by setting a load with the minimum necessary configuration.
A simple device can be miniaturized.

According to the eighth invention of the present application, since the load can be set by the elastic member such as the spring member having a high degree of freedom in setting, the desired aperture opening can be set at an arbitrary position where the load can be set.

According to the ninth invention of the present application, a desired aperture can be obtained by setting a load with the minimum necessary configuration.
A simple device can be miniaturized.

According to the tenth invention of the present application, a plurality of stages of light amount adjustment can be easily realized with high accuracy, and high-quality shooting can be performed by a simple operation.

[Brief description of drawings]

FIG. 1 is a control block diagram of an embodiment of the present invention.

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

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

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

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

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

FIG. 7 is a graph of a set load torque at the aperture of each means of one embodiment of the present invention.

FIG. 8 is a graph of a set load torque at a comprehensive aperture opening according to an embodiment of the present invention.

FIG. 9 is a timing chart diagram of a control signal waveform according to an embodiment of the present invention.

FIG. 10 is a graph of set load torque at the aperture of the second embodiment of the present invention.

FIG. 11 is a timing chart diagram of control signal waveforms according to the second embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Drive coil 2 ... Rotor magnet 3-1, 3-2 ... Stator yoke 9 ... Transmission member 6, 7, 12, 20 ... Light amount variable member 13 ...
Spring member 22 ... Aperture control means 21 ... Drive source

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[Procedure amendment]

[Submission date] September 25, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction contents]

[Document Name] Statement

Title: Light intensity adjusting device and optical instrument

[Claims]

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, a light amount adjusting device of this type has a spring in which a diaphragm plate provided with a plurality of diaphragm openings is wound up manually or by a motor as described in Japanese Patent Laid-Open No. 63-118728. It is configured to switch the aperture opening by charging with the electric power and driving the locking claw that engages with the locking portion provided on the diaphragm plate with the electromagnet and the spring.

Further, the position of the diaphragm plate is detected, and the diaphragm motor is driven by a servomotor which feeds back the detection result to control the diaphragm plate to switch the diaphragm aperture.

Alternatively, as described in Japanese Patent Application Laid-Open No. 1-101525, a stepping motor is used to drive an aperture opening / closing ring and the aperture blades switch the aperture opening.

In addition, there is known one which is configured to switch the aperture opening by a reciprocating motion of an electromagnet and a spring or the like.

[0006]

However, in the above-mentioned conventional example, the winding and locking claw mechanism, the servo motor, the stepping motor, the electromagnet, etc. are used for switching and positioning of the aperture opening. There was a flaw.

(1) Spring winding mechanism and locking claw mechanism
Servo motors, stepping motors, etc., have complicated mechanisms, resulting in larger and heavier devices, worse assembly, and higher failure rates.

(2) In servomotors, stepping motors, etc., the control methods such as negative feedback control and drive pulse train shaping are complicated and difficult, and the control drive circuit becomes large in scale.
There is concern about malfunctions such as mistaken steps or abnormal noise.

(3) With only a reciprocating drive device such as an electromagnet,
Only two apertures are available.

The objects of the first and second inventions of the present application are as follows.
The objective is to obtain a desired diaphragm aperture by simple control drive with a simple structure.

A third object of the present invention is to arbitrarily set a desired aperture opening.

A fourth object of the present invention is to make the current levels applied to the diaphragm aperture and the drive coil correspond one-to-one in one driving direction.

A fifth object of the present invention is to position a desired diaphragm aperture with high accuracy.

A sixth object of the present invention is to make it possible to set a load corresponding to a diaphragm aperture with a minimum required simple structure.

A seventh object of the present invention is to provide a diaphragm opening position corresponding to a zero level of a current supplied to a drive coil between control position limits of a drive range.

An eighth object of the present invention is to set a load corresponding to a diaphragm aperture with a minimum necessary simple structure without newly using a dedicated part.

A ninth object of the present invention is to set a load corresponding to an arbitrary number of aperture openings at an arbitrary position.

An object of the tenth invention of the present application is to set a load corresponding to a diaphragm aperture with a minimum necessary simple structure without newly using a dedicated part.

An eleventh invention of the present application is to provide an optical apparatus such as a photographing device capable of easily adjusting the light amount in a plurality of stages by using the light amount adjusting device which realizes such an object.

[0020]

In order to achieve the above object, a first invention according to the present application provides a light quantity varying member for determining a diaphragm aperture for varying the light quantity, and the light quantity varying member. A light amount adjusting device comprising: a driving source for driving; a transmitting means for transmitting a driving force of the driving source to a light amount varying member; and a diaphragm control means for forming a drive signal for energizing the driving source, wherein the driving source A light quantity adjusting device is characterized in that a load that balances with a driving force generated according to a drive signal that is energized is provided and a diaphragm aperture setting unit that obtains a desired diaphragm aperture stepwise is provided.

Further, in the second invention, the drive source includes a rotor magnet made of a permanent magnet, a stator yoke made of a ferromagnetic material which is arranged to face the rotor magnet and forms an air gap, and the stator yoke. It is constituted by a drive coil for excitation, and the diaphragm control means is capable of varying the level of a current supplied to the drive coil.

In the above structure, the aperture opening setting means is
For example, when the drive coil is energized with a predetermined current level, the drive source drives the light amount variable member to operate to position it at a desired diaphragm aperture position corresponding thereto.

In a third aspect of the invention, the aperture opening setting means is
A plurality of driving forces of a driving source generated according to the driving signal,
Set multiple balancing loads to each of the desired aperture openings
It is characterized by having.

In the above structure, the load setting means sets each load at a desired aperture opening position, and the light amount varying member is set in accordance with each current level which is applied to the drive coil which becomes the driving force of the drive source balanced with this load. When the lens is driven, the light amount variable member stops at each position, and operates so as to position at the desired diaphragm aperture position corresponding to it.

According to a fourth aspect of the invention, the aperture setting means is the above-mentioned.
Set the desired aperture corresponding to the sequential movement of the aperture position
Loads of multiple types and multiple driving forces of the drive source
Relationship increases or decreases sequentially in at least one drive direction.
It is characterized in that it is set to decrease next.

In the above arrangement, the aperture opening setting means is
A load that gradually increases or decreases is sequentially set at a desired aperture opening position, and according to each current level that is applied to the drive coil that is the driving force of the drive source balanced with this load,
When the light amount variable member is driven from one driving direction, the light amount variable member stops at each corresponding position, and operates so as to be positioned at a desired diaphragm aperture position corresponding thereto.

In the fifth invention, the aperture opening setting means is
Note that the change in the load set at the desired aperture opening position is
Rapid increase compared to load change between desired aperture positions
Alternatively, it is set to decrease .

In the above arrangement, the aperture opening setting means is
When a load that rapidly increases or decreases is set at a desired aperture opening position and the light amount variable member is driven in accordance with a wide range of current level that is applied to the drive coil that is the driving force of the drive source balanced with this load, the narrow position At this point, the light amount variable member stops and operates so as to position at the desired aperture opening position corresponding thereto.

A sixth aspect of the invention is characterized in that at least one of the loads set in a desired diaphragm opening is set by the detent torque generated between the rotor magnet and the stator yoke.

In the above arrangement, the aperture opening setting means is
For example, the light amount varying member is stopped at a position where the driving force of the drive source that drives the light amount varying member according to the current level for energizing the drive coil and the load due to the detent torque are balanced, and the light amount varying member is positioned at the corresponding desired aperture opening position. Operate.

A seventh invention is characterized in that the load set by the detent torque includes a magnetic stable point of the detent torque.

In the above arrangement, the aperture setting means has a detent torque of a zero load that balances the zero driving force of the driving source for driving the light amount variable member in response to the zero current level applied to the driving coil. The light amount variable member stops at the magnetically stable point position, in other words, the light amount variable member is driven / stopped to the magnetically stable point position by the detent torque, and operates so as to be positioned at the corresponding desired aperture opening position. .

The eighth invention is characterized in that at least one of the loads set in a desired aperture opening is set by changing the transmission efficiency of the transmission means.

In the above structure, the aperture setting means remarkably reduces or increases the efficiency of transmitting the driving force of the drive source to the light amount variable member at the desired aperture opening position, sets the corresponding load, and balances this load. When the light amount variable member is driven in accordance with each current level that is the driving force of the drive source and is applied to the drive coil, for example, the light amount variable member stops at each position and operates so as to position at the corresponding desired aperture opening position. To do.

A ninth aspect of the invention is characterized in that at least one of the loads set to a desired aperture opening is set by using the biasing force of the elastic member.

In the above structure, the opening setting means can set a load at an arbitrary position where the biasing force of the spring member, which is an elastic member, can be applied, and the drive coil which is the driving force of the drive source balanced with this load is energized. When the light amount varying member is driven in accordance with the respective current levels, the light amount varying member stops at each position and operates so as to be positioned at a desired diaphragm aperture position corresponding thereto.

A tenth aspect of the invention is characterized in that at least one of the loads set to a desired aperture opening is set by using the sliding resistance of the light amount variable member.

In the above structure, the aperture setting means sets a corresponding load by significantly reducing or increasing the sliding resistance of the light amount variable member at a desired aperture opening position, and a driving force of a drive source balanced with this load. When the light amount variable member is driven in accordance with the respective current levels applied to the drive coil, the light amount variable member stops at each position, and operates so as to be positioned at the desired diaphragm aperture position corresponding thereto.

An eleventh aspect of the invention is an optical apparatus characterized in that the amount of light to the image plane is adjusted by using the above-described light amount adjusting device.

[0040]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIG. 1 is a control block diagram showing an embodiment of a light amount adjusting device of the present invention.

In the figure, 20 is a light amount variable member driven by a drive source 21 and determines a diaphragm aperture for adjusting the passing light amount Ps, and 21 is a light amount variable member according to the drive voltage Vc of the diaphragm control means 22. It is a drive source that drives to a position balanced with the set load Te .

22 receives the luminance signal Ys of the light amount detecting device 25 and the data D1 and D4 of the memory 23 (or the data D3 of the operating portion) to determine a desired diaphragm aperture, and the drive source 21 corresponding to this diaphragm aperture is determined. The diaphragm aperture data D4 determined while outputting the driving voltage Vc for driving is stored in the memory 23.
The aperture control means for storing the data in a drive circuit 40, a control circuit 41, and a drive signal switching circuit 42.

Reference numeral 23 is a memory for storing the preset aperture opening and the data D1 of the drive signal Va corresponding thereto and the current aperture opening data D4, 24
Is an operation unit that outputs data D3 instructing the aperture opening from the outside by manual operation of the switch.

Reference numeral 25 denotes a luminance signal Y by detecting the passing light amount Ps.
A light amount detection device, which is a CCD that outputs s, is a drive circuit that outputs a drive voltage Vc for driving the drive source 21 in response to the drive signal Va of the drive signal switching circuit 42.

Reference numeral 41 denotes a luminance signal Ys of the light amount detecting device 25, the current diaphragm aperture data D4 of the memory 23, a preset diaphragm aperture and data D1 of the drive signal Va corresponding thereto.
(Or data D3 of the operation unit 24) outputs the data D2 for switching the drive signal Va determined, and stores the newly determined diaphragm aperture data D4 in the memory 23, 42 is the data of the control circuit This is a drive signal switching circuit that receives the D2 and outputs the drive signal Va (hereinafter, the same portions are designated by the same reference numerals, and duplicate description will be omitted).

FIG. 2 shows a circuit diagram of the drive circuit 40 in the block diagram shown in FIG.

In the figure, reference numeral 1 is a drive coil (resistance value Rc) for rotationally driving the rotor magnet 2 by a current Ic supplied by the drive voltage Vc of the diaphragm control means 22,
Reference numeral 2 is a rotor magnet for driving the light amount variable member 20 in accordance with the current Ic passed through the drive coil, and reference numeral 21 is a drive source including the drive coil 1 and the rotor magnet 2.

Reference numeral 40 is a drive circuit including a voltage follower circuit 50 and an inverting circuit 51, 42 is a drive signal switching circuit including a D / A converter, and 50 is a drive signal switching circuit 4
A voltage follower circuit that receives the drive signal Va of No. 2 and voltage-buffers it and supplies it to one terminal of the drive coil 1. Reference numeral 51 inverts the output voltage of the voltage follower circuit 50 with respect to the reference voltage Vf. An inverting circuit that supplies the other terminal.

FIG. 3 is a block diagram of a video 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. And a camera control circuit section 20 including a light amount variable member 6/7.
A light amount variable member for determining a diaphragm aperture consisting of 12.

Reference numeral 24 designates an operation section for manually outputting the data to instruct the enlargement ratio and the focus movement in addition to the aperture value (aperture aperture) by the manual operation of the switch, and 26 designates the video signal from the luminance signal Ys of the light quantity detecting device 25. This is an output video signal processing circuit.

Reference numeral 27 represents the luminance signal Ys of the light amount detecting device 25, the control of the memory 23, the current aperture value (aperture aperture) data, and the information of the zoom motor control section (or the operation section 24).
Auto focus motor 28 according to the output signal of
Is an autofocus control unit for driving the camera to match the focus of the subject.

28 is an autofocus motor for driving a focus lens 29 in accordance with the output signal of the autofocus 27, and 29 is the light amount detecting device 2 for focusing the object.
5, a zoom lens controller 30 for driving the zoom motor 31 based on the output signal of the operation unit 24 and the data of the memory 23 to change the magnification ratio of the image, and a zoom motor control unit 31. A zoom motor for driving the zoom lens 32 according to the output signal of the unit 30, a zoom lens 32 for varying the magnification ratio of the 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.

Reference numeral 1 is a drive coil wound around a coil bobbin 1a and mounted on a stator yoke 3-1. Reference numeral 1a is a coil bobbin for winding the drive coil. Reference numeral 2 is mounted on a rotary shaft 9c of a transmission member 9 and is a stator. York 3-1
3-2 is a rotor magnet which is rotatably arranged with a hollow wall formed in the circumferential portion formed at the tip of the rotor magnet and which is magnetized with two poles in the radial direction. The stator yoke is made of a ferromagnetic material in which magnetic poles 3a having an opening angle of more than 90 degrees are formed in a circumferential portion which is arranged opposite to the rotor magnet 2 via a hollow wall.

3-2 is connected to the stator yoke 3-1 and is a strong magnetic pole 3b having an opening angle of more than 90 degrees formed on the circumferential portion opposed to the rotor magnet 2 via the hollow wall. In the stator yoke made of a magnetic material, the stator yoke 3-1 and the stator yoke 3-2 form a magnetic circuit with the rotor magnet 2, and the magnetic stable point is set to a desired (F8) aperture value which is a drive range. By doing so, the load due to the detent torque is set.

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.
And a stopper 4c that comes into contact with the peripheral portion of the drive pin 9b of the transmission member 9 and a stopper 4d that comes into contact with the peripheral portion of the drive pin 9a of the transmission member 9, and the base plate 5 for supporting and locking each member is provided. Is a cap for the other bearing of the rotary shaft 9c of the transmission member 9.

Reference numeral 6 has a slit 6a for fitting with the drive pin 9a of the transmitting member 9 to transmit the driving force from the transmitting member and a rough surface portion 6b having a significantly large friction coefficient, and adjusts the amount of light passing therethrough. The light amount varying member 6b is a rough surface portion having a remarkably large friction coefficient, which is a load setting means for sliding the light amount varying member 12 within the aperture value range of F16 to F22 to set the load.

Reference numeral 7 is a light quantity varying member for fitting 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 passing light. Reference numeral 8 denotes an aperture case which has an opening 8a for allowing the amount of light to pass therethrough and supports the light amount variable members 6, 7 and 12, and 9 is a drive pin 9a which fits into the slit 6a of the light amount variable member 6.
And the slit 7a of the light amount variable member 7 and the light amount variable member 1
2 has a drive pin 9b that fits into the slit 12a, a rotary shaft 9c into which the rotor magnet 2 is press-fitted, and an operating arm 13c of the spring member 13 and a spring operating pin 9d that abuts in the aperture range of F2 to F4. Rotor magnet 2
Is a transmitting member for transmitting the driving torque of the driving torque to the light amount varying members 6, 7, 12 and the peripheral portions of the driving pins 9b, 9a contact the stoppers 4c, 4d of the main plate 4 so that the driving range and the light amount of the rotor magnet 2 can be changed. It has a function as a regulation means for regulating the movement range of the members 6, 7, and 12.

Reference numeral 10 is a printed circuit board on which the terminals of the drive coil 1 are soldered to receive the drive voltage Vc of the diaphragm control means 22, and 11 is an optical axis of the amount of passing light.

Reference numeral 12 is a light amount variable member for adjusting the amount of light passing therethrough, and has an L-shaped slit 12a that fits with the drive pin 9b of the transmission member 9, and this fitting relationship is F11.
The load can be set by changing the transmission efficiency from 0 to nearly 100% so that the contact is made in the aperture value range of to F22 and not to be made in the range of F2 to F11.

Reference numeral 13 denotes a spring member which is an elastic member, and has a coil inner diameter 13a for supporting it, a fixed arm 13b for fixing one end thereof, a spring operating pin 9d, and abutting in the aperture value range of F2 to F4. It has an operating arm 13c that operates together while being energized, and energizes the transmission member in the aperture value range of F2 to F4 to set the load.

Here, the drive source 21 is composed of a drive coil 1, a rotor magnet 2, and stator yokes 3-1 and 3-2.

In the present embodiment having the above-mentioned structure, the light amount variable members 6, 7, 12 are used to control F2, F4, F8, F1.
Six stages of aperture openings corresponding to 1 · F16 · F22 are sequentially set within the drive range.

FIG. 5 shows a plan view of the light quantity adjusting device of FIG.

In FIG. 5, the base plate 4 is provided with a spring member fixing pin 4e for mounting and fixing the fixing arm 13b of the spring member 13 and a coil inner diameter 13a for supporting the spring member 13 for supporting. Spring member support pin 4f and a spring member biasing holding pin 4g for holding the actuating arm 13c of the spring member 13 in a charged state so as to be operable in a range limited to the aperture value range of F2 to F4. .

FIG. 6 is a model diagram of the one-phase excitation motor of the present embodiment. Θa is an opening angle larger than 90 degrees of the magnetic pole 3a of the stator yoke 3-1 and Θb is the magnetic pole 3b of the stator yoke 3-2. The opening angle Θc, which is larger than 90 degrees, is the drive regulation range at the N pole position of the rotor magnet 2.

Reference numeral 60 is a restriction position of the open diaphragm at the N pole position of the rotor magnet 2, 61 is a restriction position of the small diaphragm at the N pole position of the rotor magnet 2, and N.
S indicates the magnetic pole polarity position of the magnetized magnetic pole.

X indicates a magnetically 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, and O indicates a magnetically unstable point at the N pole position of the rotor magnet 2. Show.

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 3-1 and 3-2 at that angular position of the magnetic pole, + is the opposite Clockwise direction.

FIG. 7 is a graph of the set load torque at the aperture of each means of this embodiment, and the + direction of the torque is the rotational force in the counterclockwise direction in FIG.

(A) is a graph showing the detent torque in the aperture opening where the load is set by the detent torque of the present embodiment, and the stator yoke 3-1 in which the open angle of the magnetic poles 3a and 3b in FIG. 6 is larger than 90 degrees.・ Set the magnetic stable point (×), which is the zero torque of the detent torque generated between 3-2 and the rotor magnet 2 magnetized with two poles in the radial direction, at the aperture opening position which is the aperture value of F8. However, in other regions, the detent torque acts to bias the rotor magnet 2 to the magnetically stable point.

(B) is a graph showing the load torque at the aperture opening where the load is set by the drive range regulating means of the present embodiment, and one open aperture regulating position 60 (stopper 4d and stopper 4d by the drive range regulating means). The load at the drive pin 9a peripheral portion) is set to the aperture opening position that is the aperture value of F2, and the load at the other small aperture control position 61 (restricted by the stopper 4c and the drive pin 9b peripheral portion) is set to F2.
It is set to the aperture opening position which is the aperture value of 2.

(C) is a graph showing the spring torque at the aperture opening in which the load is set by the urging force of the spring member which is the elastic member of this embodiment. The spring torque of the charged spring member 13 suddenly changes from F4 to F2. The load is set so as to be almost constantly urged in the small aperture direction up to the aperture opening position range which is the aperture value.

(D) is a graph showing the load torque at the aperture opening where the load is set by changing the transmission efficiency of this embodiment, and the L-shaped slit 12a and the drive pin are aperture values from F11 to F22. The load is set so that the drive force of the rotor magnet 2 is transmitted by contacting only up to the opening position range. Here, the arrow indicates the moving direction, and the polarity of the load torque is reversed depending on the moving direction.

(E) is a graph showing the load torque at the aperture opening where the load is set by the sliding resistance of the light amount variable member of the present embodiment, and the rough surface portion 6b and the light amount of the light amount variable member 6 having a significantly large friction coefficient. Variable member 12 is from F16 to F
The load is set so as to slide up to the aperture opening position range which is the aperture value of 22. The arrow indicates the direction of movement,
The polarity of the load torque is reversed depending on the moving direction.

FIG. 8 is a graph of the set load torque in the comprehensive aperture opening of the present embodiment, in which the respective loads shown in FIG. 7 are combined, the arrow indicates the moving direction, and the history of load torque varies depending on the moving direction. Seen.

That is, the load torque is set so as to rapidly increase or decrease with respect to each F value, and the load torque gradually increases in the moving direction from F2 to F22.

In particular, since the load torque from F8 to F22 has a history due to the engagement between the L-shaped slit 12a of the light quantity varying member 12 and the drive pin, the movement to the F value during this period requires moving from the F8 direction. There is.

FIG. 9 is a timing chart of the control signal waveform of the present embodiment. When the drive signal Va of the drive signal switching circuit changes from V1 to V6, the level of the current Ic supplied to the drive coil accordingly changes from I1 to I6. The aperture opening that changes to I6 and is set to the corresponding load torque is determined as the F value from F2 to F22.

In order to determine the aperture of F11 and F16, the drive is controlled so as to move sequentially from F8.

The inversion circuit 5 of the drive circuit 40 outputs the drive signal Va.
If it is made equal to the reference voltage Vf in 1, the energizing current Ic
Becomes a zero level (I3), the light amount control member 20 is driven and moved by the load torque, and the aperture of F8 is reached.

In the above structure, the image pickup light from the subject 33 is the lens group of the lens section A and the light amount variable member 20 (6.
It passes through the aperture opening of 7/12) and forms an image on the light amount detection device 25. In the light quantity detection device 25, the brightness signal Ys is adjusted according to the light quantity of the image pickup light to the aperture control means 22 and the video signal processing circuit 2.
6. Output to 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 passing light amount, 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). To determine the desired aperture value (aperture aperture) from the aperture data D4 and the preset aperture value (aperture aperture) of the memory 23 and the corresponding data D1 of the drive signal Va, and to switch the drive signal Va. And outputs the data D2 to the drive signal switching circuit 42 of the aperture control means 22.

In response to the digital data D2 indicating the drive signal Va, the D / A converter of the drive signal switching circuit 42 converts the digital data D2 into the analog drive signal Va to drive the aperture control means 22. Output to the circuit 40.

In response to the analog drive signal Va, the voltage follower circuit 50 of the drive circuit 40 buffers the drive signal Va and outputs it to one terminal of the drive coil 1 of the drive source 21 and at the same time, inverts the drive circuit 40. Output to the circuit 51.

In the inverting circuit 51, the voltage of one terminal of the drive coil 1 is inverted with respect to the reference voltage Vf and output to the other terminal of the drive coil 1 to drive the drive coil 1 of the drive source 21.
The positive and negative drive voltages Vc can be applied to both ends of the.

The drive coil 1 (resistance: Rc) to which the drive voltage Vc is applied has a current Ic according to the drive voltage Vc.
(Vc / Rc) is energized, and the rotor magnet 2 of the drive source 21 is rotationally driven with a drive torque according to the energized current Ic.

The rotor magnet 2 is driven by the light amount varying member 20 via the transmitting member 9 with a driving torque according to the energizing current Ic.
Drive (6, 7 and 12).

Here, the load torque against the drive torque corresponding to the current Ic of the drive source is set to each aperture value by each means shown in FIG. 7, and each load value is set to each aperture value as shown in FIG. The load torque that increases or decreases more rapidly than between the aperture values is set to sequentially increase in the moving direction of F2 → F22.

Therefore, when the drive torque balanced with the suddenly increasing or decreasing load torque set at each aperture value is applied, the rotor magnet 2 stops at the position corresponding to each aperture value and the light amount variable member 20 ( Position 6/7/12).

In particular, in order to position at the aperture value positions of F11 and F16, the drive torque is applied so as to move to the aperture value position of F8 (driving torque = 0) and then toward F22.

As to each signal of this control and the aperture opening position, as shown in FIG. 9, the drive torque corresponding to the current Ic applied to the drive coil 1 which is determined by the drive signal Va is set to each aperture value (each aperture value). It stops at each aperture value (each aperture opening) position in balance with the load set for the aperture.

That is, by determining the current Ic to be applied to the drive coil 1 which gives the drive torque balanced with the load torque set to each aperture value, the light amount variable member 20 (6. 7).
・ 12) can be positioned at each aperture value.

The light amount variable members 20 (6, 7 and 12) positioned at the positions corresponding to the respective aperture values determine the aperture opening corresponding to the aperture value.

As a result, the light amount variable member 20 (6, 7 and 12) driven and moved by the drive torque of the drive source 21.
Determines the diaphragm aperture to vary the light amount of the image pickup light passing through the lens group of the lens unit A, and adjusts the image formation light amount of the light amount detection device 25 to an appropriate exposure amount.

When the dial is turned by the operating section 24 to set the aperture value, the aperture control means 22 determines the current Ic to be applied to the drive coil 1 as described above according to the setting information D3 from the operating section 24. The driving voltage Vc is output to the driving source 21, and the driving source 21 is driven to drive the light amount variable member 20.
By moving (6, 7, 12), a desired diaphragm aperture (aperture value) is obtained.

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 unit 24 to set the enlargement ratio, the zoom motor control unit 30 drives the zoom motor 31 in accordance with a signal from the operation unit 24 to move the zoom lens 32, and image pickup is performed. Change the magnification.

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 stores the drive information set in the memory 23 so that the focus does not shift 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 to set the focus movement, the autofocus control section 27 drives the autofocus motor 28 in accordance with the signal from the operation section 24 to move the focus lens 29 to move the focus. Fluctuate.

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.

Further, the restricting position restricted by the restricting means of the transmitting member 9 is within a rotation range of the rotor magnet of 180 degrees or less, preferably 60 degrees.

The present invention is not limited to the above embodiment, the light amount detecting device 25 is an optical sensor such as a solar cell or a photo resistance change element, and an electric power such as an emitter follower is provided at the output stage of the drive circuit 40. Amplifier to which an amplifier circuit is added, Vf of the inversion circuit 51 of the drive circuit 40 is at ground potential (zero), and another terminal of the drive coil 1 is connected to the ground potential (zero) (inversion circuit 51 , The drive signal switching circuit 42 is a switch circuit such as a multiplexer, an analog switch, and a relay circuit, the rotor magnet 2 and the transmission member 9 are integrally molded, and the stator yokes 3-1 and 3-2 are driven. The coil 1 may be detachably integrated. (Second Embodiment) FIGS. 10 and 11 show a second embodiment.

The second embodiment is an embodiment in which the light amount variable member 12 is removed from the first embodiment and the load setting means by transmission efficiency and the load setting means by sliding friction resistance are not used. Is omitted, and only different points will be described.

FIG. 10 is a graph of the set load torque at the aperture opening representing the second embodiment.
The load torque due to the transmission efficiency shown in (a), the load torque due to the detent torque in (a) excluding the load torque due to sliding resistance shown in (e), (b) the load torque due to the control means of the drive range, and (c) 7 is a graph of a combination with a load torque due to the urging force of a spring member that is an elastic member.

For each F value, the load torque is set so as to increase or decrease rapidly, and the load torque gradually increases or decreases regardless of the moving direction. On the other hand, only one load corresponding to each other is set.

FIG. 11 is a timing chart drawing of a control signal waveform representing the second embodiment. When the drive signal Va of the drive signal switching circuit changes from V1 to V6, the current Ic to be supplied to the drive coil accordingly. Level is I
The aperture opening that changes from 1 to I6 and is set to the corresponding load torque is uniquely determined for each aperture value of F2 to F22.

In the above construction, it is not necessary to limit the moving direction as in the first embodiment, and the respective signals of this control and the state of the aperture opening are determined by the drive signal Va as shown in FIG. The drive torque corresponding to the current Ic flowing through the drive coil 1 is balanced with only one load set for each aperture value (each aperture opening) and each aperture value (each aperture opening).
Stop in position.

That is, by determining the current Ic to be applied to the drive coil 1 that gives the drive torque that balances the load torque set to each aperture value, the light amount variable member 20 (6.
7) can be positioned at only one position for each aperture value.

[0111]

As described above, the first embodiment according to the present application is described.
According to the invention, the stepwise desired aperture opening can be easily obtained only by switching the level of the drive signal to be supplied to the drive source.

According to the second invention of the present application, by setting the load with a high degree of freedom, it is possible to easily set a desired aperture opening at an arbitrary position where the load can be set.

According to the third invention of the present application, a desired diaphragm aperture can be easily obtained only by switching the current level applied to the drive coil from one driving direction.

According to the fourth invention of the present application, even if the driving force of the driving source varies according to the current level applied to the driving coil, the change in the load balanced with the driving force sharply increases. Alternatively, since it is reduced, it is possible to obtain a highly accurate light amount adjusting device in which an error such as a deviation from a desired aperture position is small.

According to the fifth invention of the present application, the load can be set with the minimum necessary configuration to obtain a desired aperture opening,
A simple device can be miniaturized.

According to the sixth invention of the present application, the magnetic stable point of the detent torque, which becomes the zero load corresponding to the zero driving force which can be easily realized and has a small error, is set to the desired aperture opening position. Since it is provided, it is possible to easily obtain a desired diaphragm opening with a small error.

According to the seventh invention of the present application, a desired aperture can be obtained by setting a load with the minimum necessary configuration.
A simple device can be miniaturized.

According to the eighth invention of the present application, since the load can be set by the elastic member such as the spring member having a high degree of freedom in setting, the desired aperture opening can be set at an arbitrary position where the load can be set.

According to the ninth invention of the present application, a desired aperture can be obtained by setting a load with the minimum necessary configuration.
A simple device can be miniaturized.

According to the tenth invention of the present application, a plurality of stages of light amount adjustment can be easily realized with high accuracy, and high-quality shooting can be performed by a simple operation.

[Brief description of drawings]

FIG. 1 is a control block diagram of an embodiment of the present invention.

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

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

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

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

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

FIG. 7 is a graph of a set load torque at the aperture of each means of one embodiment of the present invention.

FIG. 8 is a graph of a set load torque at a comprehensive aperture opening according to an embodiment of the present invention.

FIG. 9 is a timing chart diagram of a control signal waveform according to an embodiment of the present invention.

FIG. 10 is a graph of set load torque at the aperture of the second embodiment of the present invention.

FIG. 11 is a timing chart diagram of control signal waveforms according to the second embodiment of the present invention.

[Description of Reference Signs] 1 ... Drive coil 2 ... Rotor magnets 3-1, 3-2 ... Stator yoke 9 ... Transmission member 6, 7, 12, 20 ... Light amount variable member 13.・ ・
Spring member 22 ... Aperture control means 21 ... Drive source

[Procedure amendment 2]

[Document name to be amended] Drawing

[Correction target item name] Figure 9

[Correction method] Change

[Correction contents]

[Figure 9]

Claims (11)

[Claims] 1. A light amount variable member for determining a diaphragm aperture for changing the light amount, a drive source for driving the light amount variable member, and a driving force of the drive source transmitted to the light amount variable member. In a light amount adjusting device having a transmission means and an aperture control means for forming a drive signal for energizing the drive source, a step is provided in which a load that balances with a drive force generated according to the drive signal for energizing the drive source is provided. A device for adjusting the amount of light, characterized in that a stop aperture setting means for obtaining a desired stop aperture is provided. 2. The drive source according to claim 1, wherein the drive source is a rotor magnet made of a permanent magnet, a stator yoke made of a ferromagnetic material arranged to face the rotor magnet to form an air gap, and the stator yoke is excited. And a drive coil for controlling the amount of current flowing through the drive coil. 3. The aperture opening setting means according to claim 1, wherein a plurality of loads balanced with a plurality of driving forces of a drive source generated in response to the drive signal are set in the respective desired aperture openings. A light quantity adjusting device characterized in that 4. The relationship according to claim 3, wherein the aperture opening setting means sets a plurality of types of loads for setting a desired aperture corresponding to the sequential movement of the aperture opening position and loads by a plurality of driving forces of the drive source. Is set so as to sequentially increase or decrease in at least one driving direction. 5. The change of the load set to the desired aperture opening position by the aperture opening setting means in comparison with the change of the load between the desired aperture opening positions,
A light quantity adjusting device, which is set so as to rapidly increase or decrease. 6. The method according to claim 2, 3 or 5, wherein at least one of the loads set in the desired aperture opening is set by a detent torque generated between the rotor magnet and the stator yoke. Light control device. 7. The light amount adjusting device according to claim 6, wherein the load set by the detent torque includes a magnetic stable point of the detent torque. 8. The method according to claim 1, 2, 3, or 5,
At least one of the loads set to the desired aperture opening is set by changing the transmission efficiency of the transmission means. 9. The method according to claim 1, 2, 3, or 5,
At least one of the loads set in the desired aperture opening is set by using the urging force of an elastic member. 10. The load according to claim 1, 2, 3 or 5, wherein at least one of the loads set to the desired aperture opening is set by using a sliding resistance of a light amount variable member. Light control device. 11. An optical apparatus, wherein the light quantity adjusting device according to claim 1 is used to adjust the quantity of light to an image plane.