JPH11271588A - Lens driving device and optical equipment with same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lens driving device that uses plural plungers as inexpensive actuators and drives a lens by one electric circuit which is as simple as possible. SOLUTION: The lens driving device is constituted by providing the plungers 1 and 6 which operate with mutually different current quantities, lens moving mechanisms 3, 10, 4, 11, 9, and 15 which change the optical-axis direction of the lens 5 according to whether those plungers are on or off, and a current quantity setting means which sets the quantities of currents fed to the plungers at the same time according to a target position of the lens.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens driving device for driving a lens for performing focus control or the like.

[0002]

2. Description of the Related Art Many lens driving devices mounted on optical devices such as cameras use an actuator such as a DC motor or a stepping motor as a driving source. However, if an actuator such as a DC motor or a stepping motor is used as a drive source of the lens driving device, the device becomes very expensive, and the control of energizing and stopping the motor tends to be complicated. Therefore, a lens driving device using an inexpensive plunger as a driving source has been proposed.

Here, as a lens driving device using a plunger, a two-stage moving type in which a movable yoke that is displaced depending on whether or not a current is supplied to the plunger moves the lens in the optical axis direction in conjunction with the movable yoke is generally used. However, Japanese Patent Laid-Open No. 5-1
As proposed in Japanese Patent No. 34300, there is also a three-stage movement type lens driving device using a plunger.
This lens drive uses two plungers,
By not energizing both plungers, the lens is positioned at the intermediate position, and by selecting the plunger to be energized, the lens is moved to the extended side position and the retracted side position with respect to the intermediate position.

[0004]

However, in the lens driving device proposed in the above publication, it is necessary to switch the energization of the two plungers, and there is a problem that a complicated switching circuit is required in the electric circuit. is there.

Therefore, in the present invention, a plurality of plungers, which are inexpensive actuators, are used, and the simplest possible one is used.
It is an object of the present invention to provide a lens driving device capable of driving a lens with two electric circuits.

[0006]

In order to achieve the above-mentioned object, the present invention provides a plurality of plungers which are operated with different amounts of current, and an optical axis direction of a lens corresponding to the operation and non-operation of these plungers. A lens driving device is provided by providing a lens moving mechanism for changing the position and a power supply setting means for setting a power supply for simultaneously supplying power to a plurality of plungers according to a target position of the lens.

More specifically, a first power supply which operates at a first amount of power supply is provided.
A plunger and a second plunger that operates with a second current amount larger than the first current amount are provided, and the current amount setting means includes a small current amount equal to or more than the first current amount and smaller than the second current amount. By selectively setting a large amount of current equal to or more than the amount of current, it is possible to perform two-stage switching of the lens position according to the magnitude of the amount of current.

That is, by employing a configuration in which the amount of current that is simultaneously applied to a plurality of plungers is changed by the amount-of-current setting means that is one electric circuit to change the lens position, the configuration of the electric circuit is simplified, The cost of the entire device is reduced.

When the plurality of plungers are not energized, the lens is positioned at a target position different from the target position which is energized and driven by the plurality of plungers.
It is also possible to increase the number of moving stages of the lens without complicating the electric circuit.

As a specific lens moving mechanism,
A first interlocking member urged in one direction along the optical axis and driven in the other direction by actuation of the first plunger; and a second interlocking member connected to the lens and urged in the other direction in the optical axis. A restricting member that is located at a restricting position that restricts the movement of the second interlocking member beyond the predetermined position in the other direction of the optical axis when the second plunger is not operated, and that is retracted from the restricted position by operating the second plunger. When the small energizing amount is set by the energizing amount setting means, the second interlocking member abuts on the regulating member (at the regulating position) and is positioned at the predetermined position, and when the large energizing amount is set, The two interlocking members may be brought into contact with the first interlocking member driven in the other side in the optical axis direction and positioned at a position on the other side in the optical axis direction from the predetermined position. Further, when the energization amounts of the first and second plungers are set to zero by the energization amount setting means, the second interlocking member is moved from the predetermined position by the first interlocking member which has been urged in one direction in the optical axis direction. What is necessary is just to position it in the position of one side in the optical axis direction.

[0011] The lens driving device described above is
If the target position of the lens (focus lens) is set based on focus operation information obtained by detection or measurement, it can be used as a focus control device in an optical device such as a camera.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIGS. 1 to 3 are plan views of a focus lens driving device according to a first embodiment of the present invention, and FIG. FIG. 2 shows a front view (a front view in the optical axis direction) of the device. The focus lens driving device is used by being built in a lens barrel or a barrel portion of a camera.

In these figures, reference numeral 1 denotes a state in which the movable yoke 2 is moved rearward in the optical axis direction when a current of a first magnitude (hereinafter, referred to as a first current, a first amount of current referred to in the claims) is applied. It is a first plunger that operates in a suction direction (A direction in the figure).
Reference numeral 3 denotes a first interlocking lever (first interlocking member referred to in the claims) that is connected to the movable yoke 2 and moves together with the movable yoke 2 in the optical axis direction. Reference numeral 10 denotes a first spring that biases the first interlocking lever 3 forward in the optical axis direction (direction B in the drawing).

Reference numeral 4 denotes a lens holding frame for holding the focus lens 5;
A second interlocking lever (a second interlocking member referred to in the claims) that is connected to the lens holding frame 4 and moves integrally with the lens holding frame 4 in the optical axis direction. Reference numeral 11 denotes a second spring for urging the second interlocking lever 8 rearward in the optical axis direction.

Reference numeral 6 denotes a second plunger for attracting the movable yoke 7 backward in the optical axis direction when a second current (a second current amount in the claims) that is larger than the first current is applied. Reference numeral 9 denotes a regulating lever (a regulating member referred to in the claims) that is connected to the movable yoke 7 and rotates around a shaft 14 in the directions C and D in the figure. Further, reference numeral 15 designates the regulating lever 9 as the second
The third spring urges in the direction (D direction) opposite to the rotation direction (C direction) by the operation of the plunger 6.

Reference numerals 12 and 13 are guide shafts for guiding the lens holding frame 4 and both interlocking levers 3 and 8 in the optical axis direction.
Note that, as shown in FIG.
a, 4b engages with the guide shafts 12, 13, and the two interlocking levers 3, 8 are respectively connected to the guide shafts 1 by the U-shaped portions 3b, 8b.
2 or the guide shaft 13.

FIG. 5 shows the two plungers 1 and 6 described above.
1 shows a configuration of an electric circuit (current supply amount setting means referred to in the claims) for performing simultaneous power supply to the power supply. Reference numeral 17 denotes a CPU for controlling the entire camera, and reference numerals 18 and 19 denote output ports of the CPU 17.

Reference numeral 20 denotes output ports 18 and 19 of the CPU 17.
Is a D / A converter that converts a digital value determined by the above into a corresponding analog voltage, and 21 is a reference voltage generation circuit that generates a reference voltage of the D / A converter 20.

Reference numeral 22 denotes a VB connected to a battery (not shown).
An AT terminal 23 has first and second plungers 1 and 2.
6 is a transistor for driving the transistor 6. 24 is a detection resistor for converting the current flowing through both plungers 1 and 6 into a voltage,
Reference numeral 25 denotes a voltage generated in the detection resistor 24 when the D / A converter 20
Transistor 23 so as to be equal to the D / A output voltage of
This is an OPAMP that drives.

In the electric circuit configured as described above,
The CPU 17 outputs a current flowing through the plungers 1 and 6 to the output port 18 and sets the current in the D / A converter 20. The D / A converter 20 generates a difference between the reference voltage 27 generated by the reference voltage generation circuit 21 and the analog voltage determined by the output port 18 of the CPU 17 as a D / A output voltage 28. OPAMP 25 has an enable terminal and CP
It is controlled by the output port 19 of U17. CPU17
When the output port 19 is set to the enable state, the OP
The AMP 25 starts operating and drives the transistor 23.

The current supplied to the plungers 1 and 6 is as follows: supplied current (A) = (D / A set voltage (V)) / (detection resistance (Ω)).

It should be noted that the ON / OFF of energization is determined by the output port 1
9, the energizing current can be changed at the output port 18.

Next, the operation of the lens driving device configured as described above will be described. First, FIG. 1 shows a state in which electric power is not supplied to both plungers 1 and 6 by an electric circuit. In this state, the first interlocking lever 3 is connected to the first spring 1
It is located forward (in the direction B) in the optical axis direction by the urging force of zero. For this reason, the second interlocking lever 8 and the lens holding frame 4 (the lens 5) urged rearward in the optical axis direction (A direction) by the second spring 11 are connected to the protrusion 8 a formed on the second interlocking lever 8. Abuts on a protruding portion 3a formed on the first interlocking lever 3 to be positioned at the first focus position. Note that this state corresponds to a standby state before autofocus is performed in the camera. In this state, the regulating lever 9 is urged in the direction D by the third spring 15, and is positioned at the regulating position shown in FIG.

Then, auto-focusing is performed, and the CPU 17 moves the lens 5 from the CPU 17 based on a focus detection signal or a distance measurement signal (focus operation information described in claims).
When a signal for moving to the focus position (a predetermined position in the claims) is output, the first current (or a current slightly larger than this) is supplied to both plungers 1 and 6 by an electric circuit. Is supplied. As a result, the first plunger 1 operates, while the second plunger 6 is kept inactive.

When the first plunger 1 operates, the movable yoke 2
Is sucked rearward in the optical axis direction (direction A), the first interlocking lever 3 also moves rearward in the optical axis direction while charging the spring 10 in conjunction with the movable yoke 2, as shown in FIG. As a result, the second interlock lever 8 and the lens holding frame 4 that have been positioned by the first interlock lever 3 until then become
It moves rearward in the optical axis direction by the urging force of the second spring 11. However, the second interlock lever 8 and the lens holding frame 4
After the movement by the predetermined amount, the movement comes into contact with the regulating lever 9 located at the regulating position, and the further backward movement is regulated. Thereby, the second interlock lever 8 and the lens holding frame 4 (lens 5) are positioned at the second focus position.

When a signal for moving the lens 5 to the third focus position is output from the CPU 17 based on the focus detection signal or the distance measurement signal, the second current is supplied to both plungers 1 and 6 by an electric circuit. (Or a slightly larger current: a large amount of current referred to in the claims). Thereby, both the first plunger 1 and the second plunger 6 operate.

As described above, when the first plunger 1 is operated and the movable yoke 2 is sucked rearward in the optical axis direction (direction A), as shown in FIG. The spring 10 is moved rearward in the optical axis direction while charging the spring 10 in conjunction with. As a result, the first interlocking lever 3
The second interlocking lever 8 and the lens holding frame 4 that have been positioned by the second spring 11 move rearward in the optical axis direction by the urging force of the second spring 11.

On the other hand, when the second plunger 6 is actuated and the movable yoke 7 is sucked, the regulating lever 9 rotates around the shaft 14 in the direction C in the figure and is located at the allowable position shown in FIG.

For this reason, the second interlocking lever 8 and the lens holding frame 4 move rearward from the second focus position without being restricted by the restriction lever 9. Thus, the second interlocking lever 8 and the lens holding frame 4 that have moved backward from the second focus position are moved to the first plunger 1.
The projection 8a comes into contact with the projection 3a of the first interlocking lever 3 that has been moved by the operation described above, whereby the first focus lever 3 is positioned at the third focus position. After the focusing is performed as described above, the photographing operation of the camera is performed after waiting for the release operation.

When the power supply to the plungers 1 and 6 is completed, the movable yokes 2 and 7 are released from the suction state. Thus, the first interlocking lever 3 is moved forward (in the direction B) in the optical axis direction by the urging force of the first spring 10. At this time, the first interlocking lever 3 makes the second interlocking lever 8 and the lens holding frame 4 (lens 5) by contact of the protruding portions 3a, 8a.
Is moved forward in the optical axis direction against the urging force of the second spring 11. Thus, the second interlock lever 8 and the lens holding frame 4
(Lens 5) returns to the first focus position.

On the other hand, the regulating lever 9 is rotated about the shaft 14 in the direction D by the urging force of the third spring 15, and returns to the regulating position.

As described above, according to the present embodiment, it is possible to energize the two plungers 1 and 6 at the same time with one electric circuit, and to change the energizing current to connect the lens 5 to the second and the second plungers. The third focus position can be set. In addition, the lens 5 can be set at the first focus position by turning off both the plungers 1 and 6. Also,
Whether or not the current is supplied to the plungers 1 and 6 and the setting of the supplied current can be controlled by the focus detection result or the distance measurement result of the camera.

That is, based on the focus detection result or the distance measurement result, one electric circuit does not energize the two plungers, and energizes the two plungers with a current equal to or more than the first current and less than the second current. By performing control such that a current equal to or more than the current is supplied, focus control can be performed. Therefore, it is possible to realize a three-stage moving type focus lens driving device using an inexpensive plunger and using a simple electric circuit.

In the above embodiment, the plunger is 2
Although the case where a plurality of plungers are used has been described, it is also possible to energize three or four plungers at the same time with one electric circuit. A focus lens driving device of a multi-stage movement type having three or more stages can be realized.

Further, in the above embodiment, the drive device for the focus lens has been described. However, the present invention can be applied to a drive device for a lens other than the focus lens.

[0036]

As described above, according to the present invention,
The configuration is such that the lens position is changed by changing the amount of energization that simultaneously energizes the plurality of plungers by the energization amount setting means, which is one electric circuit, so that the configuration of the electric circuit can be simplified and the overall apparatus can be simplified. The cost can be reduced.

When the plurality of plungers are not energized, if the lens is located at a target position different from the target position at the time of energization, the number of moving stages of the lens can be increased without complicating the structure of the electric circuit. Can be done.

[Brief description of the drawings]

FIG. 1 is a plan view of a focus lens driving device (non-energized state) according to a first embodiment of the present invention.

FIG. 2 is a plan view of the focus lens driving device (in a state where a small current is applied).

FIG. 3 is a plan view of the focus lens driving device (in a state where a large current is supplied).

FIG. 4 is a front view of the focus lens driving device.

FIG. 5 is an electric circuit diagram of the focus lens driving device.

[Explanation of symbols]

 1,6 plunger 2,7 movable yoke 3,8 interlocking lever 3a, 8a projecting part 3b, 8b, 4a, 4b U-shaped part 4 lens holding frame 5 focus lens 9 regulating lever 10,11,15 spring 12,13 guide shaft 16 Engagement pin

Claims (7)

[Claims] 1. A plurality of plungers that operate with different amounts of electricity, a lens moving mechanism that changes the position of the lens in the optical axis direction according to the operation and non-operation of these plungers, and a target position of the lens. A lens drive device comprising: a current-carrying amount setting unit configured to set a current-carrying amount for simultaneously supplying current to the plurality of plungers. A first plunger that operates with a first amount of current; and a second plunger that operates with a second amount of current greater than the first amount of current. 2. The lens driving device according to claim 1, wherein a small amount of current that is equal to or larger than the first amount of current and smaller than the second amount of current and a large amount of current that is equal to or larger than the second amount of current are selectively set. 3. The apparatus according to claim 1, wherein when the plurality of plungers are not energized, the lens is located at a target position different from a target position which is energized and driven by the plurality of plungers. The lens driving device as described in the above. 4. The lens moving mechanism is urged in one direction along the optical axis and is connected to the lens with a first interlocking member driven in the other direction along the optical axis by operation of the first plunger. Second biased to the other side in the optical axis direction
An interlocking member and the second plunger when the second plunger is not actuated;
A restricting member that is located at a restricting position that restricts movement of the interlocking member beyond the predetermined position in the other direction of the optical axis, and that is retracted from the restricting position by operating the second plunger; When the small energizing amount is set by the energizing amount setting means, the regulating member is positioned at the predetermined position, and when the large energizing amount is set, the first interlocking member is driven in the other direction along the optical axis. The lens driving device according to claim 2, wherein the lens driving device is positioned at a position on the other side in the optical axis direction from the predetermined position. 5. When the first and second plungers are not energized, the second interlocking member is moved further in the optical axis direction than the predetermined position by the first interlocking member biased and moved in one direction in the optical axis direction. The lens driving device according to claim 4, wherein the lens driving device is positioned at a position on one side. 6. An optical apparatus comprising the lens driving device according to claim 1. 7. The optical apparatus according to claim 6, wherein the lens is a focus lens, and the target position is set based on focus operation information obtained by detection or measurement.