JPS59184919A - Mechanical position controller - Google Patents

Abstract

PURPOSE:To secure the control at a desired position for a mechanical element such as a camera shutter control plate, etc. which receives the stepped or stepless setting for its control position, by using a piezoelectric function element which has a bending deformation in response to the applied voltage. CONSTITUTION:When a shutter release button is pushed, a photometric circuit 21 works to deliver the voltage signal in response to the luminance of a subject. When the subject luminance has a medium level, the level of the voltage signal is higher than a reference voltage V2 and lower than the voltage V1 respectively. Therefore a comparator C01 delivers an L signal; while comparators C02 and C03 deliver H signals. In this case, the output of an AND gate A2 is equal to an H signal. Then transistors TR5 and TR2 conduct, and the divided voltage VB is applied to a piezoelectric function element 3. Thus the element 3 has a bending deformation in response to the level of the applied voltage. As a result, a shutter speed control plate moves so that its medium step part is set as opposed to the tip part of a branch bar of a shutter level.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field This invention relates to a camera shutter control board, A? The present invention relates to a mechanical position control device that uses a piezoelectric element to control a mechanical element, such as a lens control plate, whose regulating position is set stepwise or steplessly to a desired position.

Conventional technology As an exposure amount control mechanism in a camera, the deflection angle of a meter pointer that displays subject brightness is detected by a step cam that is linked to the release operation, and the stroke difference is used to adjust the aperture of the shutter aperture blade. The amount of exposure is determined by changing the shutter blades or by controlling the speed by changing the aperture of the shutter blades, or in the case where the shutter blades and diaphragm blades are used together.

Regarding the position control of the AV lens, conventionally, a step cam is provided on the outer periphery of the lens barrel, and a position regulation bin that can interfere with the step cam is displaced in accordance with the output signal from the AF distance measuring mechanism, thereby regulating the position. The lens stop position is determined by selecting the stepped portion of the stepped cam that the pin comes into contact with.

However, since the meter has seven coils, it is bulky, and since the pointer, which is supported in a swinging manner, is simply made to swing by magnetic force, the ability to make the pointer dig in is weak, making it impossible to stably and reliably control its position.

Note that in order to make the pointer swing stably, a larger coil is required and a larger current must be passed through it.

Purpose This invention solves the above-mentioned drawbacks in the conventional example, and provides a piezoelectric element (product name:
We decided to use a pymorph element.

It is highly reliable, easy to configure, and inexpensive, allowing mechanical elements such as camera shutter control boards and AF lens control boards whose regulation positions are set stepwise or steplessly to the desired position. The purpose of this invention is to provide an inexpensive mechanical position control device.

Example A first embodiment of the invention is shown in FIGS. 1 to 3.

The mechanical position control device according to the embodiment is applied to a shutter speed control mechanism in a camera, and in FIG. 1a, lb.

A long hole 1d formed in the middle body.

1e to a pin 2a protruding from the inner wall of the camera housing.

2b (C) is arranged so that it can move forward and backward in its longitudinal direction by engaging.

Reference numeral 3 denotes a piezoelectric actuating element which bends and deforms in a varying amount according to the applied voltage, and its lower end is fixed to the camera housing so that the direction of the bending deformation is aligned with the advance/retreat direction of the shutter speed control board 1, while its upper end is fixed to the camera housing. As shown in FIG. 2, the shutter speed control plate l is engaged with the engagement fork part If at the rear end of the plate l,
The shutter speed control plate 1 moves forward and backward as the piezoelectric element 3 bends and deforms.

Reference numeral 4 denotes a roughly shaped shutter lever having two branch pieces 4a and 4b, one of which is a branch piece 4a (D tip end is stepped portion 1a, Ib at the tip end of the shutter speed control plate 1,
When the middle part is pivoted to the inner wall of the camera housing by means of a pin 5 so as to be in a position facing lc, the middle part is biased counterclockwise by a coil spring 6 connected to the other branch piece 4b. A pin 7 is provided at the tip of the branch piece 4b, and the pin 7 is inserted into the long holes 10a and 10b in the middle body of a pair of shutter blades 9a and 9b whose base ends are pivotally connected to the camera casing with pins 8a and 8b, respectively. When engaged, the pair of shutter blades 9a and 9b rotate in opposite directions as the shutter lever 4 rotates, allowing the shutter to open and close.

Reference numeral 11 denotes a slide plate, and guide elongated holes 11a and llb formed in the middle body of the slide plate are connected to pins 1 protruding from the inner wall of the camera housing.
2a and 12b, it can freely move forward and backward in parallel with the shutter speed control plate 1, and is tensilely biased in one direction by a coil spring 13 connected to one end. A lever 15 is pivotally attached to one side of the slide plate 11 by a pin 14, and the slide plate
1, the protruding piece 15a of the lever 15 contacts the pin 16 of the shutter lever 4, and the shutter lever 4 is rotated clockwise against the coil spring 6. One end of the lever 15 is stopped by a rotation locking pin 17 provided on the slide plate 11 to restrict the lever 15 to a predetermined rotational position with its protruding piece 15a facing downward. It is wound and biased clockwise by a threaded spring 18 whose each end is locked to a pin 17 and one end of the lever 15.

The slide plate 11 is connected to the shutter release button and the film winding mechanism, and the coil spring 1 is connected to the shutter release button and the film winding mechanism.
3, and when the lever 15 reaches a predetermined position where it touches the pin 16 of the shutter lever 4 by 5u), it is stopped by a locking means (not shown). The locking by the locking means is released.

The circuit shown in FIG. 3 is a piezoelectric element drive circuit that applies a predetermined voltage to give a deflection deformation to the E electric element 3, and is a strobe booster that serves as a power source for the strobe LX and the strobe control circuit 19. A predetermined voltage taken out from the circuit 20 through the diode D is connected to one resistor R1e R.
9s Re series circuit with 3 levels of voltage V, VB, Va
a drive stage in which the divided voltages VA, VB, and VC are applied to the piezoelectric element 3 through three branch circuits each having transistors TR1, TRg, and TR connected therebetween; It consists of a control stage which receives a signal of a level corresponding to the brightness of the object outputted from the circuit 2 and turns on the branch circuit corresponding to the signal level among the three branch circuits of the drive stage.

The control stage includes a resistor R12+ 118 * R14+
A photometric circuit is constructed using a reference voltage circuit section in which R18 is connected in series and each molecule V1 t "'!l, vs obtained by dividing the DC power supply voltage VCC into three stages as a reference voltage by the reference electrical circuit section. Comparators 0゜□, 0゜2゜Oo compare the output signals from 20 with these reference voltages.
AND game corresponding to each of these comparators)A□
I A 2 + A s and inverter IxtI*
From such things, it becomes ＼.

Transistor TR1s T R95T R of the drive stage
At the base of e, there is a resistor RB + Re +
Transistors TR'4, TR6,
'FRa is connected to the base of each transistor, and the AND gate I + As e of the control stage is connected.
Al is connected in correspondence with each other.

Next, we will explain the operation of this mechanical position control device.○ When the release button is pressed in the shutter charging state shown in Fig. 1, the photometry circuit 21 operates and outputs a voltage from this circuit at a level corresponding to the brightness of the subject. A signal is output. When the level of this voltage signal corresponds to, for example, medium brightness of the object brightness divided into three levels of high, medium, and low, the level of this voltage signal corresponds to the resistance R14 and Rls of the reference voltage circuit section. A reference voltage V obtained from a series part including
It is larger and smaller than the reference voltage ■1 obtained from the series section including the resistors R1B1B14yB15. Therefore, the comparator 0°1 outputs a D signal (low voltage signal), and the comparator 0°g+o111+ outputs an H signal (high voltage signal). At this time, AND
In the game, the L signal of the comparator C61 is inverted by the inverter, and the H signal of the comparator 002 is inverted.
Since the signal is used as an input signal, its output becomes an H signal, transistors TR, TR9 conduct, and resistor RIIIR becomes conductive.
A divided voltage VB obtained from the series section including m is applied to the piezoelectric effecting element 3.

On the other hand, since the AND gate A1 uses the DC power supply voltage 1 VCC and the L signal of the comparator O6 as input signals,
The output will be the L signal.0 or AND game, then,
Since the H signal of the comparator C6 is inverted by the inverter r[-1, and the H signal of the comparator C6 is the input signal, its output becomes an L signal. Therefore, both transistors TR4 and TR, are not conductive, and the two branch circuits each having transistors TRQ, , TR, in series are not conductive.

The electric current operating element 3 to which the partial voltage VB obtained from the series section including the resistor R9#RI is applied is deflected to the right in FIG. 1 by an amount corresponding to the applied voltage, and the shutter speed control plate 1, the middle step part lb is the shutter lever 4.
The branch piece 4a is moved to a position opposite to the tip of the branch piece 4a.

After the above operation, the slide plate 1 by the above-mentioned locking means is
1 is released, and the slide plate 11 is moved by the coil spring 13.
Due to the tensile action of , it travels to the right in Fig. 1. During this traveling operation, the lever 15 kicks the pin 16 of the shutter lever 4, so the shutter lever 4 rotates clockwise against the coil spring 6. The amount of movement during that time is regulated by the collision of the tip of the branch piece 4a of the shutter lever 4 with the intermediate stage portion 1b of the shutter speed control plate 1, so the shutter blades 9a, 9 follow the rotation of the shutter lever 4.
Time b! The IflJ amount is also regulated, and the shutter speed corresponding to the subject brightness is determined.

After the tip of the branch piece 4a of the shutter lever 4 collides with the intermediate step 1b of the shutter speed control plate 1, the shutter lever 4 is rotated counterclockwise by the action of the coil spring 6, and the shutter is closed by this action. Growth is measured.

Even after the slide plate 11 kicks the pin 16 of the shutter lever 4, the slide plate 11 continues to the right and stops when it hits a regulating member (not shown).

During shutter charging that is performed in conjunction with the film winding operation, the slide plate 11 resists the coil spring 13 and moves to the first position.
Move to the left in the diagram. During this movement, when the protruding piece 15a of the lever 15 hits the pin 16 of the shutter lever 4, the lever 15 rotates counterclockwise against the torsion spring 18, thereby riding over the pin 16. Thereafter, the receiver returns to the rotational position where it is stopped by the rotation stopper 17.

Similarly, when the photometric circuit 21 outputs a voltage signal at a level corresponding to high brightness, the control stage outputs an H signal, and the drive stage transistor TR1 becomes conductive. Voltage VA is applied to the piezoelectric element 3, and due to the deflection deformation of the piezoelectric element 3 at this time, the shutter speed control plate 1 is moved to a position where its step IC faces the tip of the branch piece 4a of the shutter lever 4. Move up.・On the other hand, when the photometric circuit 21 outputs a voltage signal at a level corresponding to low brightness, the AND game
outputs an H signal, the transistor TR in the drive stage becomes conductive, and EEVO is applied to the piezoelectric element 3, and due to the deflection deformation of the piezoelectric element 3 at this time, the shutter speed control plate l moves to a position where its stepped portion 1a faces the tip of the branch piece 4a of the shutter lever 4.

A second embodiment of the invention is shown in FIG.

In the mechanical position control device of this embodiment, the shutter speed control plate 1 in the first embodiment is omitted, and instead, a plurality of stepped portions 4' are provided at the tip of one branch of the shutter shutter bar 4'. A step portion 4'a of the shutter lever 4' forms a, 4'b, and 4'O, and the tip of the piezoelectric element 3 comes into contact with the deflection deformation of the piezoelectric element 3.

4'b and 4'c are interchangeable, thereby making it possible to variably set the shutter speed, and the omission of the shutter speed control plate further simplifies the overall configuration.

The other configurations are the same as those of the first embodiment. - A third embodiment of the invention is shown in FIGS. 5 and 6.

The mechanical position control device of this embodiment is
This is applied to the F lens control mechanism. In FIG. 5, 22 is a lens control plate that is integrated with the lens barrel, and a plurality of stepped portions 22& are formed on a part of its outer periphery.

22b and 22a, and connected to the other part of the outer periphery.
It is biased counterclockwise by a tension spring 23.

In FIG. 5, assuming that the front side of the page is the lens feeding direction, the lens and the lens control plate 22 are linked together so that the larger the counterclockwise rotating claw of the lens control plate 22 is, the larger the lens feeding amount is. Reference numeral 24 designates a position control lever that rotates within the same plane as the lens control plate 22, and one branch piece 24a of the lever 24 is placed in the rotation range of the stepped portions 22a, 22b, and 22a of the lens control plate 22. It is pivotally connected to the camera housing with pin 25 so that it can move forward and backward.

Reference numeral 26 denotes a piezoelectric element, one end of which is fixed to the camera housing in a posture such that its deflection deformation occurs within the rotation plane of the lens control plate 22, while its free end side is fixed to the camera housing as shown in FIG. The position is controlled so that the other branch piece 24b engages with the engagement fork portion 240 of the other branch piece 24b at t<-24, and the one branch piece 24a engages with the engagement fork portion 240 of the other branch piece 24b at the step of the lens control plate 22 according to the deflection deformation of the piezoelectric element 26. It is designed to advance to any of the five rotation areas 22a, 22b, and 22a.

The lens control plate 22 is locked by a locking means (not shown) at the rotational position shown in FIG. 5 when the film winding is completed, and is not locked by the locking means during the release operation. It is linked with the film winding mechanism and the release button so that it is released and rotated counterclockwise by the tension spring 23.

The piezoelectric element drive circuit for imparting deflection deformation to the piezoelectric element 26 uses the output signal of the photometric circuit 21 as a signal input to the control stage in the circuit of the first embodiment (shown in FIG. 3). The only difference is that an output signal from an AF circuit that detects the distance to the object and outputs a signal at a level corresponding to the distance is applied instead, and the other configurations are exactly the same.

The operation of this mechanical position control device will be explained throughout Europe.

When the release button is pressed in the state shown in FIG. 5, the AF circuit described above operates and outputs a voltage signal at a level corresponding to the distance to the subject. The piezoelectric element drive circuit that receives this output signal performs the same operation as in the first embodiment, and applies a voltage to the piezoelectric element 26 at a level corresponding to the object distance. For example, when the subject distance is in the middle of the three stages of long distance, middle distance, and short distance, an intermediate level voltage VC is applied to the piezoelectric element 26, referring to the circuit shown in FIG. The deflection deformation of the piezoelectric element 26 due to the applied voltage is caused by the position regulating lever 24.
The branch piece 24a is connected to the middle step part 22 of the lens control plate 22.
It is rotated to a position that advances into the rotation range b.

After the above operation, the lens control plate 22 is unlocked by the locking means described above, and the lens control plate 22 (1) is rotated counterclockwise by the action of the tension spring 23, and the intermediate step portion 22b is in the position. The receiver is moved by the branch piece 24a of the regulating lever 24, and the lens is stopped at an extended position corresponding to a medium-distance object.

Similarly, when the output signal of the AF circuit corresponds to a long-distance subject, the branch piece 24a of the position regulation lever 24 is located in the rotation range of the stepped portion 22a, and the output signal of the AF circuit corresponds to a close-distance subject. At this time, the branch piece 24a of the position regulating lever 24 is located in the rotation range of the stepped portion 22'C, and regulates the lens to the corresponding extended position.

In each of the above embodiments, the case of stepwise (three-step) seven-position control has been described, but the piezoelectric actuating elements 3, 26 described above
Since the applied voltage and the amount of deflection displacement are proportional, it is of course applicable to the case of performing stepless position control.

In each of the embodiments described above, by changing the relative position of the step-like cam and the stopper member that engages therewith using the displacement of the piezoelectric actuating elements 3 and 26, it is possible to determine which step of the step-like cam the stopper member engages with. Since I configured it so that you can choose whether to
Distance ti between each step of the stepped cam! By appropriately selecting tut, position control over an arbitrary distance can be achieved with a small displacement of the piezoelectrically active element 3.26.

Effects According to the mechanical position control device of the present invention, the mechanical element is displaceably provided, and the piezoelectric element is flexibly deformed in accordance with the applied voltage and regulates the position of the mechanical element to a selected position according to the amount of deformation. , comprising a position signal generation circuit that outputs a signal that determines the selected position of the mechanical element, and a piezoelectric element drive circuit that applies a voltage to the piezoelectric element according to the output signal of the position signal generation circuit. Since there is no need to place a coil near the piezoelectric element, it can be configured compactly, and one end of the piezoelectric element can be fixed, so even if it receives a shock, the piezoelectric element will not accidentally move. Displacement can be prevented, allowing stable and reliable position regulation. Furthermore, since the tE electrical effecting element consumes less power and can be obtained at low cost, the position control device N with low power consumption can be provided at low cost.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a first embodiment of the present invention, FIG. 2 is a partially enlarged perspective view thereof, FIG. 3 is a diagram showing a piezoelectric element drive circuit thereof, and FIG. FIG. 5 is a diagram showing a third embodiment of the present invention, and FIG. 6 is a partially enlarged perspective view thereof. 1... Shutter speed control board (mechanical element), 1a/l
b, lc...Stepped portion, 3...Piezoelectric effect element, 4'...
・Shutter lever (mechanical element), 4'a, 4'b
, 4'c one-stage part, 21... Photometry circuit (position signal generation circuit), 22... Lens control board (mechanical element), 24
...Position regulating lever, 26...Piezoelectric element applicant Minolta Camera Co., Ltd.

Claims (1)

[Claims] a mechanical element provided to be displaceable; a piezoelectric element that deflects and deforms in response to applied EEK and regulates the position of the mechanical element to a selected position according to the amount of deformation; and a position that outputs a signal that determines the selected position of the mechanical element. A mechanical position control device comprising: a signal generation circuit; and a voltage according to the output signal of the position signal generation circuit;