JPH0812369B2 - Camera with bimorph drive element - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera, and more particularly to a camera having a bimorph drive element that is displaced when a high voltage is applied.

2. Description of the Related Art Conventionally, a camera using the bimorph drive element as described above for driving a photographing lens or a shutter is disclosed in
It is known in JP-A-60-144726 and JP-A-59-204014.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention An object of the present invention is to provide an apparatus capable of easily changing a program diagram of an exposure program in a camera that drives a shutter using such a bimorph driving element. It is in.

Means for Solving the Problems In order to achieve the above object, according to the present invention, since the bimorph driving element is a capacitor in terms of an equivalent circuit, the charging current to this capacitor is changed to change the changing speed of the charging voltage. It was made paying attention to the fact that it is possible to change the displacement speed of the bimorph drive element,
Therefore, the camera according to the present invention has a bimorph drive element that controls opening and closing of a shutter that also serves as an aperture, a charging unit that charges the bimorph drive element, and a current adjusting unit that changes a current for charging, It is characterized in that the exposure program diagram is changed by changing the charging current of the bimorph drive element.

Effect According to the present invention, the exposure program diagram can be easily changed by changing the displacement speed of the bimorph driving element by changing the charging current of the bimorph driving element.

Embodiments Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a block diagram showing an electric circuit used in a camera according to an embodiment of the present invention. In Fig. 1, (1)
Is a microcomputer (hereinafter, referred to as a microcomputer) that performs sequence control and calculation of the camera, and (2) is a photometric circuit that outputs a photometric value (Bv) corresponding to subject brightness as a digital signal to the microcomputer (1). (3) is a film sensitivity reading circuit, and the read film sensitivity value (Sv)
Is output to the microcomputer (1) as a digital signal.
(4) is a film winding circuit including a film winding motor, and (5) is a booster circuit for boosting the low voltage of the power supply battery (MB) to a high voltage. (6) (7) (8)
These are switching circuits for switching whether or not to supply the above high voltage to an exposure control circuit (9), a lens drive circuit (10), and a flash control circuit (11) described later, respectively. (9) is an exposure control circuit that controls the exposure based on the exposure signal from the microcomputer (1), (10) is a lens drive circuit that drives the lens based on the lens drive signal from the microcomputer (1),
(11) is a flash circuit that emits flash light in response to a light emission signal from the microcomputer (1).

(12) is a display circuit in the viewfinder, which provides a low-brightness warning and a display that allows photographing in the viewfinder field.
Reference numeral (13) is a distance measuring circuit for measuring the distance from the camera to the object and outputting the measured distance as a digital signal to the microcomputer (1).

(MB) is the main power supply that supplies power to the circuit of the entire camera,
(BB) is a backup power supply for backing up the microcomputer (1), (D ₁ ) and (D ₂ ) are diodes for preventing reverse charging, and (Tr ₁ ) is an output terminal (OP ₀ ) of the microcomputer (1).
Is a power supply transistor controlled by.

Next, the switches will be described. (S ₀ ) is a lens cover interlock switch that turns “ON” when a lens cover (not shown) is opened, and the microcomputer (1) interrupts when this switch (S ₀ ) turns ON. When the terminal (INT ₁ ) changes from “H” level to “L” level, the “S ₀ ON” routine described later is executed.

(S ₁ ) is a photometric switch that is turned “ON” by pressing the first stroke of a shutter release button (not shown), and the microcomputer (1) is switched from “OFF” to “ON” or “ON” of this switch (S ₁ ). From the change from "" to "OFF", the "S ₁ " interrupt routine described later is executed. (14) is the metering switch (S ₁ ) from "ON" to "OFF" or "OFF" to "ON"
It is a one-shot pulse generation circuit that generates one pulse according to the change due to. (S ₂ ) is "O" when the shutter release button is pressed until the second stroke, which is longer than the first stroke.
Use the release switch to “N” and press “O” of this switch (S ₂ ).
Shooting is started by "N". Furthermore, (S ₃ ) is a one-frame switch that turns “ON” when the winding of one frame of film is completed,
(S ₄ ) is an aperture monitor switch that is turned “ON” just before the exposure is started by driving the shutter in the aperture direction, and is composed of a photocoupler. The output of this photocoupler is normally at "H" level, and when the shutter reaches the initial position, a current flows through the light receiving section and outputs "L" level. That is, the switch (S ₄ ) is for correcting variations in the initial position of the shutter. Therefore, when using a shutter in which the initial position does not vary, it is not necessary separately. (S ₅ ) is a switch that turns “ON” when returning to the initial position after the shutter is closed.

(S ₆ ) and (S ₇ ) are mode switches for setting the exposure mode. In the present embodiment, there are three exposure modes, a narrowing-down mode, a shutter speed priority mode, and a normal mode. Switch (S ₆ ) (S ₇ ) “O”
Either mode is determined by the combination of N and OFF.

Next, the shutter driving mechanism of the lens shutter and the driving method of the shutter used in this embodiment, and the driving mechanism of the lens and the driving method thereof will be briefly described. The shutter and the lens of the present embodiment are configured to be indirectly driven by the bimorph drive element provided in each.

First, FIG. 2 shows a mechanism for driving the shutter. In FIG. 2, (15) and (16) are shutter blades, and these shutter blades (15) and (16) have small holes (15a) (16a) and slots (15c) (16c), respectively. It is rotatably supported by the shaft (17). And, the arm (15b) extended from the shutter blade (15) has a pin (18).
Has been planted. Further, the opening / closing lever (19) having the arms (19a) and (19b) is supported by the shaft (20),
The pin (19c) implanted in the arm (19a) engages with the slots (15c) (16c) of the shutter blade, while the free end of the bimorph drive element (Bi ₁ ) is attached to the arm (19b) by the pin (21). Are connected by. Here, the distance from the shaft (20) to the pin (19c) is about 5 times the distance from the shaft (20) to the pin (21).
Therefore, the operation of the bimorph driving element (Bi ₁ ) is increased to increase the shutter blades (15) (1).
6) is passed on.

In FIG. 2, the bimorph drive element (Bi ₁ ) is supported in a cantilever shape with its left end fixed and the right free end is shown in the enlarged view of FIGS. 3 (a) and 3 (b). As described above, it is connected to the lever (19). FIG. 3 (a) shows a side view of the bimorph drive element (Bi ₁ ), and FIG. 3 (b) shows a top view thereof. In the figure, a bimorph drive element (Bi ₁ ) has a metal substrate (22) and piezoelectric elements (23) (24) arranged on both front and back surfaces thereof, and the tip of the substrate (22) is extended. A bent portion (22a) is formed, and the pin (21) is engaged with the bent portion (22a).

With such a configuration, the bimorph drive element (Bi ₁ )
When the electrodes are short-circuited, the shutter blades (15) (16) are rotated to the closed position via the opening / closing lever (19) as shown in FIG. Rotate the open / close lever (19) to rotate the shutter blades (15) (1
6) Open.

Further, FIG. 4 shows the lens driving mechanism of this embodiment. FIG. 4 (a) is a front view of the lens driving mechanism, and FIG. 4 (b) is a side view thereof. In FIGS. 4 (a) and 4 (b), (L) is a taking lens, and a holding frame (25) integrally holding the taking lens (L) is a feeding guide planted on the base plate (26). A support arm (25a) fitted to the rod (27),
Arms (25
b) and (25c) are supported by the guide rod (27) so as to be movable in the optical axis direction, and are attached to the left side of FIG. 4 (b) by the spring (28), that is, in the feeding direction. Energized,
Each arm (25a) (25b) (25c) is in elastic contact with the cam part (29a) (29a) (29a) of the payout cam ring (29).

Further, the feeding cam ring (29) has three cam portions (29a) (29a) of the same shape, which are arranged 120 ° apart from each other.
(29a) and ratchet pawls (29b) provided all around the perimeter
And the protrusions (29c) (29c) that are separated by 120 °.
(29c) and are supported so as to rotate around the optical axis. The cam ring (29) is prevented from rotating counterclockwise in FIG. 4 (a) by the leaf spring (30) that engages with the ratchet pawl (29b) and can rotate only clockwise. Is.

The feed claw lever (31) has a feed claw (31a) that engages with the ratchet claw (29b) of the cam ring (29), and is rotatably connected to the tip of the bimorph drive element (Bi ₂ ). The feed claw (31
a) is in elastic contact with the ratchet claw (29b). Here, the bimorph drive element (Bi ₂ ) is supported in a cantilever shape by fixing the lower end portion in FIG. 4 (a), and the free end portion is connected to the feed claw lever (31) as described above. There is.

In the initial state shown in FIG. 4 (a), the holding frame (2
The arms (25a) (25b) and (25c) of 5) are in contact with the lower positions of the cam portions (29a) (29a) (29a) of the cam ring (29), respectively. (twenty five)
It is being carried along with. Further, the projection (29c) of the cam ring (29) is engaged with the pin (18) penetrating the elongated hole (26a) of the base plate (26) to close the shutter blades (15) (16). Is locked to.

With this configuration, the bimorph drive element (Bi ₂ )
When a voltage is applied to the electrode of ( ₁ ) and then short-circuited, the bimorph drive element (Bi ₂ ) bends counterclockwise in FIG. 4 (a) and then substantially returns to its initial shape. This one-time vibration causes the feed claw (31a) of the feed claw lever (31) to ride over one of the ratchet claws (29b) and then the ratchet claw (2
Pull 9b) to the right in the figure and rotate the cam ring (29) clockwise by one tooth. When this vibration is repeated, the ratchet pawl (29b) is sequentially fed in the clockwise direction, and the cam portions (29a) (29a) (29a) are moved together with the lens holding frame (25) by a predetermined amount corresponding to the number of feed teeth. (L) is delivered. Since each cam portion (29a) is formed so as to be gradually higher from the bottom while gradually inclining, the urging force of the spring (28) increases as the lens holding frame (25) is extended. However, the acting force required to feed the cam ring (29) by one tooth is not so large.

Here, between the bimorph drive element (Bi ₂ ) and the feed claw (31a), as in the lever (19) shown in FIG. 2,
A lever for increasing the vibration of the bimorph drive element (Bi ₂ ) may be provided.

FIG. 5 shows a modified example of the lens driving mechanism shown in FIG. 4 (a), which includes a spring (32) for urging the cam ring (29) to an initial position and a ratchet pawl () of the cam ring (29). 29b) engaged with one of the locking levers (3) to prevent the cam ring (29) from returning to the initial position.
3) and are provided.

The bimorph drive element (Bi ₂ ) is controlled so as to make a small vibration with a small amplitude and a large vibration with a large amplitude in the counterclockwise direction in the figure. When one small vibration occurs, the feed pawl lever (31) feeds the ratchet pawl (29b) by one tooth. On the other hand, when a large vibration occurs, the tip of the feed claw lever (31) pushes the locking lever (33) against the bias to a position where it is disengaged from the ratchet claw (29b), so that the cam ring (29). Is returned to the initial position by the urging force of the spring (32).

FIG. 6 is a front view showing another modified example of the lens driving mechanism shown in FIG. 4 (a), in which a switch (34) for detecting that the cam ring (29) has rotated to the initial position is provided. I have it.

Here, each of the bimorph drive elements (Bi ₁ ) (Bi ₂ ) has a voltage-displacement amount characteristic as shown in FIG. 7 (a), and when one end is fixed and a voltage is applied, the other end is fixed. Is designed to be displaced. Now, when a positive voltage is applied to one piezoelectric element (B) shown in FIG. 7 (b) to the other piezoelectric element (A), the bimorph drive element (in the direction shown by the arrow in FIG. Bi ₁ ) turns. By this movement,
An amplification lever (20) provided at the end opposite to the fixed end of the bimorph moves, the movement opens and closes the shutter, and the amount of movement determines the exposure amount.

As a method of controlling the movement amount of the bimorph drive element, (a) a method of controlling the applied voltage to control the displacement amount,
(B) A method of monitoring the displacement amount and stopping the application of the voltage when the displacement amount reaches a predetermined displacement amount can be considered. However, in the case of (b), the displacement is monitored (for example, an encoder).
Therefore, the method (a) is used in this embodiment. In this embodiment, as the method (a), the voltage is controlled by accumulating charges in the capacitor component of the bimorph drive element itself,
This voltage is controlled by monitoring the time required for storage.

Next, a circuit diagram including a circuit for controlling the shutter will be described with reference to FIG. The circuit shown in FIG. 8 includes a booster circuit (5) including transistors (Tr ₂ ) to (Tr ₅ ), a resistor (R ₁ ), and a DC-DC converter (DC-DC), and a transistor (T
r ₆₎ ~ consisting (Tr ₁₀₎ switching circuit (6) (7) (8)
And capacitor (C ₂ ) (C ₃ ), voltage detection circuit (BC ₁ ),
The exposure control circuit (9) includes transistors (Tr ₁₁ ) to (Tr ₂₀ ) and a bimorph drive element (Bi ₁ ).

Two boosted voltages are taken out from the secondary winding of the DC-DC converter (DC-DC). Of these, the diode (D ₅ )
And the voltage (V ₅ ) across the transistor (Tr ₁₀ ) is the 10th
The voltage (V ₃ ) is supplied to the flash circuit (11) shown in the figure, and passes through the diode (D ₃ ) and transistor (Tr ₇ ).
(Here, V ₃ <V ₅ ) is supplied to the exposure control circuit (9). In addition, diode (D ₄ ) and transistor (Tr ₈ )
The voltage (V ₄ ) (here, V ₄ = V ₃ ) via is supplied to the lens drive circuit (10) shown in FIG. The exposure control circuit (9) shown in FIG. 8 includes a capacitor (C ₂ ) for accumulating electric charges, a voltage detection circuit (BC ₁ ) for detecting a voltage accumulated in the capacitor (C ₂ ), and a bimorph. Drive element (Bi ₁ )
And a capacitor (C ₃ ) connected in parallel to this bimorph drive element (Bi ₁ ) and a control transistor (Tr ₁₁ ) ~
(Tr ₂₀ ) and.

This voltage detection circuit (BC ₁ ) is "H" if it detects 200V.
Input the level detection signal to the microcomputer (1) input terminal (IP ₈ )
Output to. By inputting this signal, the microcomputer (1) turns off the transistors (Tr ₆ ) (Tr ₇ ) (Tr ₈ ) of the switching circuits (6) (7) ( ₈ ), respectively, and the booster circuit (5) ) Boost transistor (Tr ₂ ) to “OF
"F" to stop boosting.

Next, control transistors (Tr ₁₁ ) to (T ₁₁ ) for applying the voltage thus obtained to the bimorph drive element (Bi ₁ )
r ₂₀ ) will be explained. The shutter of this embodiment is the 11th
As shown in the figure, (a)
(B) (c) Three types of shutter speed (T) and aperture (F)
Value)), and in order to realize this combination, the current flowing through the bimorph drive element (Bi ₁ ) is regulated and the bimorph drive element (Bi ₁ ) is controlled.
The charge to the capacitor component of i ₁ ) is controlled to
The inclination of the exposure program line shown in the figure (combination of aperture and shutter speed) is determined. The exposure amount is controlled by the exposure time.

Here, the current to the bimorph drive element (Bi ₁ ) is regulated by the combination of the transistor (Tr ₁₁ ) (Tr ₁₂ ) and the resistor (Ra), the transistor (Tr ₁₃ ) (T
r ₁₄ ) and a resistor (Rb), and a transistor (Tr ₁₅ ) (Tr ₁₆ ) and a resistor (Rc).
And the resistance value of each resistance (Ra) (Rb) (Rc)
When Ra, Rb, and Rc are set, Ra <Rb <Rc is set, and when the transistors (Tr ₁₁ ) (Tr ₁₂ ) turn on, the 11th
Program line (a) and transistor (Tr ₁₃ ) in the figure
When (Tr ₁₄ ) is “ON”, it follows the program line of (b) shown in FIG. 11, and when the transistors (Tr ₁₅ ) (Tr ₁₆ ) is “ON”, it follows the program line of (c) shown in FIG. 11. Exposure amount is controlled. This will be described later.

The collector side of the bimorph (Bi ₁ ) transistor (Tr ₁₈ ) corresponds to the piezoelectric element (B) of FIG. 7B. now,
Transistor (Tr ₁₁ ) (Tr ₁₂ ) and transistor (T
When r ₁₈ ) is turned “ON”, the piezoelectric element (B) shown in FIG. 7 (a) is grounded, and the piezoelectric element (A) has a voltage of 200V via the resistor (Ra) and the transistor (Tr ₁₂ ). The charge is accumulated in the capacitor component (CBi) of the bimorph drive element (Bi ₁ ) and the capacitor (C ₃ ) provided in parallel with it, and the charging voltage increases, and the bimorph drive element (Bi ₁ ) becomes As the time goes by, the shutter opening waveform becomes like the program line (a) in FIG. Here, this capacitor (C ₃ ) is a bimorph drive element (Bi
It regulates the amount of displacement with respect to time that occurs because the capacitance of the capacitor component (CBi) in ₁ ) is small.

Then, at Figure 11 illustrates the time (t ₁₎ the voltage applied to the bimorph driving element (Bi ₁₎ reaches 200V, bimorph drive elements (Bi ₁₎ keeps this state. Here, if a predetermined exposure amount is reached, for example, at time (t ₂ ) before the applied voltage to the bimorph drive element (Bi ₁ ) reaches 200 V, both transistors (Tr ₁₁ ) and (Tr ₁₂ ) are turned off. After that, the transistor (Tr ₁₇ ) is turned on to short-circuit both ends of the bimorph drive element (Bi ₁ ) and close the shutter. As a result, the shutter closes and the exposure ends, but the shutter is a bimorph drive element (Bi ₁ ).
It does not return to the initial position due to the hysteresis characteristics.

Therefore, in order to return this to the initial position, a reverse voltage is applied to the bimorph drive element (Bi ₁ ). Therefore, turn off the transistor (Tr ₁₈ ) and turn on the transistors (Tr ₁₉ ) and (Tr ₂₀ ) so that the voltage of the piezoelectric element (B) becomes higher than that of the piezoelectric element (A). To However, if a voltage is suddenly applied to the bimorph drive element (Bi ₁ ), the voltage will turn in the opposite direction too much, so the resistance (Rd) will be the collector of the transistor (Tr ₂₀ ) and the piezoelectric element (B) of the bimorph drive element (Bi ₁ ). Put in between. In this way, a voltage is gradually applied to the bimorph drive element (Bi ₁ ) to bend it in the opposite direction. Then, when the shutter is returned to the initial position (this is the "O" of the switch (S ₅ ) provided at the initial position.
N ”), transistor (Tr ₁₉ ) (Tr
₂₀ ) Turn off (Tr ₁₇ ) each and stop applying more voltage. This operation is performed for each photographing.

Next, the diagram showing the relationship between the aperture and the shutter speed with respect to the brightness shown in FIG. 11 will be described. In FIG. 11, the program line (a) is the shutter speed priority type,
The program line (b) shows a normal type, and the program line (c) shows a diaphragm priority type. According to the type set by the operation of the mode switch, the combination of the aperture and the shutter speed shown in this figure can be obtained according to the brightness. For example, subject brightness Bv = 6 and film sensitivity Sv = 5
When (ISO = 100), Av = 4 (F number = 4) and Tv = 7 in the shutter speed priority type program line (a).
(Shutter speed = 1/125), so with the normal type program line (b), Av = 4.5 (F number = 4.8) and
Tv = 6.5 (shutter speed = 1/90), and Av = 5 (F number = 5. In the program line (c) of aperture priority type.
6) and Tv = 6 (shutter speed = 1/60). And
The brightness equivalent to the shutter speed (1/30), which is the limit of camera shake, is Ev = 7.5 for the shutter speed priority type program line (a) and Ev for the normal type program line (b).
v = 8.0, Ev = in the program line (c) of aperture priority type
It is 9.0, and when it becomes darker than that, the shutter speed is closed at this timing and the flash is fired at an appropriate aperture value by the flashmatic. Where Ev
Represents the exposure amount and is defined by Ev = Bv + Sv = Av + Tv.

Next, the drive circuit (10) for the taking lens shown in FIG. 9 will be described. In this embodiment, as described above, the endless type ratchet is driven to change the circular movement into the linear movement to drive the photographing lens, and the lens is driven to a position according to the distance information to the subject. The microcomputer (1) sends necessary pulses to the lens drive circuit (10),
The driving amount of the photographing lens is controlled according to the number of pulses. First, after the exposure operation is completed, the number N1 of pulses required for lens driving for focus adjustment is subtracted from the number N of pulses required for the photographing lens to make one round trip from infinity to the closest distance. The number of pulses N-N1 of the microcomputer (1)
Is sent to the lens drive circuit (10), which returns the lens to the initial position. A circuit for controlling this is the lens drive circuit shown in FIG. This lens drive circuit (10)
In ( ₁ ), the voltage Va corresponding to the amount of displacement required for ratchet feeding is stored in the capacitor (C ₅ ) and the voltage Vb required to return the lens to the initial position is stored in the capacitor (C ₄ ). Then, by turning on the transistor (Tr ₂₄ ), the bimorph drive element (B
The voltage Va accumulated in the capacitor (C ₅ ) is applied to i ₂ ) to displace the bimorph drive element (Bi ₂ ) for driving the lens for focus adjustment. Then, once turn off this transistor (Tr ₂₄ ), turn on the transistor (T
r ₂₃ ) is turned on and the voltage Vb stored in the capacitor (C ₄ ) is applied to the bimorph drive element (Bi ₂ ) in the reverse direction,
Return the bimorph drive element (Bi ₂ ) to the initial position.
This is the number of pulses N-N1 sent from the microcomputer (1).
Just repeat. Here, the transistor (Tr ₂₄ ) is "O" when the output terminal (OP ₁₃ ) of the microcomputer (1) is at "H" level.
When the transistor (Tr ₂₂ ) that becomes “N” turns “ON”, “O”
N ”, and the transistor (Tr ₂₃ ) is the output terminal (OP ₁₃ )
Is a "ON" transistor when it is at "L" level (Tr
It becomes “ON” by “ON” in ₂₁ ). (35) is a delay circuit connected to the output terminal (OP ₁₂ ) of the microcomputer (1). In the last written to the "H" level pulse from the microcomputer (1) the output terminal (OP _13), an output terminal (OP ₁₃₎ is "L" level, which the inverted signal and the output terminal (OP _The AND circuit (AN ₁ ) to which the "H" level signal from ₁₂ ) is input outputs the "H" level signal to turn on the transistors (Tr ₂₁ ) (Tr ₂₃ ) and the bimorph drive element. (Bi ₂₎ a reverse voltage is applied to prevent the displacement in the direction opposite to the displacement direction to be driven bimorph driving element (Bi _2). As a result, the negative voltage is not applied before the positive voltage is applied to the bimorph (Bi ₂ ). In addition, here, the output terminal (OP ₁₂ ) of the microcomputer (1)
It is configured to be "H" level immediately before the pulse is output from the output terminal (OP _13).

Next, the flash circuit (11) shown in FIG. 10 will be described. In FIG. 10, (C ₆₎ is a capacitor for storing emission energy, (BC ₂₎ is a voltage detection circuit for monitoring a charging voltage of the capacitor (C _6), the voltage is the desired voltage of the capacitor (C ₆₎ When it becomes, the charge completion signal is output. This charge completion signal is input to the input terminal (IP
₉ ), which stops the boosting operation by the booster circuit (5). Reference numeral (36) is a light emission control circuit, which changes the charging energy of the capacitor (C ₆ ) according to the light emission signal from the output terminal (OP ₁₄ ) of the microcomputer (1) to the xenon tube (37).
To discharge the light through the xenon tube (37).

The sequence operation of the camera constituted by the above circuits will be described with reference to the flow chart of the microcomputer (1) shown in FIG.

First, when the lens cover or lens cap (not shown) is opened, the switch (S ₀ ) turns “ON”, and the interrupt terminal (INT ₁ ) of the microcomputer (1) changes from “H” level to “L” level. A signal that changes as follows is input, and this signal causes the microcomputer (1) to interrupt, and the flow of the interrupt routine "S ₀ ON" shown in FIG. 12 is executed. The microcomputer (1) first resets various flags and output terminals to "L" level in step # 1 (hereinafter abbreviated as step), and sets the output terminal (OP ₀ ) to "H" level in # 2 to supply power. Turn on the transistor (Tr ₁ ) and supply power to each circuit. Then, in # 3, it is determined whether or not the photometric switch (S ₁ ) is "ON" by detecting the signal of the input terminal (IP ₁ ). When the switch (S ₁ ) is "ON", Go to # 22, and if it is "OFF", go to # 4
Execute the following "S ₁ OFF" routine.

In the "S ₁ OFF" routine, first at # 4, output terminal (O
P ₂ ) is set to “L” level to stop the boosting operation of the booster circuit (5) once, and the output terminal (OP ₁₀ ) is set to “L” level in # 5 and the switching circuit (8) is set to “OFF”. The boosting operation of the flash circuit (11) is also stopped. Then, in # 6, the output terminals (OP ₁₁ ) are used to charge the capacitors (C ₂ ) (C ₄ ) (C ₅ ) for driving both bimorph drive elements (Bi ₁ ) (Bi ₂ ) respectively. To "H" level and switch circuit (6)
(7) is turned “ON”, the output terminal (OP ₂ ) is set to “H” level in # 7, and the transistor (Tr ₂ ) is turned “ON” to start boosting.

When the charging voltage of the capacitor (C ₂ ) for driving the exposure control bimorph drive element (Bi ₁ ) reaches a desired voltage, the voltage detection circuit (BC ₁ ) causes the microcomputer (1) to
Since the charging completion signal is sent to the input terminal (IP ₈ ) of
At 8, the process waits until this charge completion signal is input. When this signal is input, the microcomputer (1) sets the output terminal (OP ₁₁ ) to the "L" level in # 9 and turns off both the switching circuits (6) and (7). At this time, the capacitor (C ₄ )
The voltage charged in (C ₅ ) is the same as the voltage charged in the capacitor (C ₂ ) because the circuit configuration is the same.
Next, the microcomputer (1) sets the output terminal (OP ₆ ) to the “L” level at # 10 to stop the boosting operation of the capacitor (C ₃ ) once, and sets the output terminal (OP ₁₀ ) at the “H” level at # 11. Then, turn on the transistors (Tr ₉ ) (Tr ₁₀ ) of the switching circuit and turn on the capacitor (C ₆ ) of the flash circuit (11). Further, at # 12, the output terminal (OP ₆ ) is set to the “H” level again to start boosting the bimorph driving capacitor (C ₃ ) of the exposure control circuit (9).

Then, in # 13, the charging completion signal is input to the input terminal (IP ₉ ) of the microcomputer (1) while waiting for the charging completion signal to be sent from the voltage detection circuit (BC ₂ ) of the flash circuit (11). If so, the output terminal (OP ₆ ) is set to the “L” level in # 14 to stop the boosting of the bimorph driving capacitor (C ₃ ), and the output terminal (OP ₁₀ ) is switched to the “L” level in # 15. Set the transistor (Tr ₉ ) (Tr ₁₀ ) of the circuit to "O" respectively.
Set to "FF" to stop boosting the capacitor (C ₆ ) of the flash circuit (11), set the output terminal (OP ₀ ) to "L" level in # 16, and set the power supply transistor (Tr ₁ ) to "OFF" to operate. To stop.

The metering switch (S ₁ ) turns from “OFF” to “ON” or “O”.
When the N "to" OFF ", the input is pulse generated from one shot pulse generating circuit (14) to the interrupt terminal (INT ₂₎ of the microcomputer (1). When this interrupt signal is input, the microcomputer (1) executes the flow of the interrupt routine "S ₁ ".

In this interrupt routine "S ₁ ", first in # 17, the microcomputer (1) determines whether or not the photometric switch (S ₁ ) is "ON" by determining the input terminal (IP ₁ ), and the switch (S ₁₎ If “) is“ OFF ”, proceed to # 6. On the other hand, if the metering switch (S ₁ ) is “ON”, output terminal (OP
And ₆₎ to the "L" level to stop the boosting of the bimorph driving capacitor (C _3), further # 19, the output terminal in at _{# 20 (OP 10) (OP} 11) also cut in the "L" level circuit Set all to "OFF". Then, various flags and output terminals are reset in # 21, and the output terminal (OP ₁₁ ) is set to "H" in # 22.
Set the level to the transistor of the switching circuit for bimorph (Tr
₆ ) Turn on (Tr ₇ ) to start boosting the bimorph drive capacitor (C ₃ ), and reset the built-in timer at # 23. This timer measures the time required for the capacitors (C ₂ ) (C ₄ ) (C ₅ ) for the bimorph drive elements (Bi ₁ ) (Bi ₂ ) to complete charging. When the consumption level is estimated and the time required to complete the charging is equal to or longer than a predetermined time, it is determined that the battery consumption level is high, and the voltage detection circuit (BC ₁ ) gives a warning.

And in # 24, the output terminal (OP ₂ ) of the microcomputer (1)
Is set to the "H" level to start the boosting operation of the boosting circuit (5), and in # 25, the charging completion signal from the voltage detecting circuit (BC ₁ ) is waited for. When this charge completion signal is input, the timer is stopped at # 26, and at # 27 and # 28,
The output terminals (OP ₂ ) (OP ₁₁ ) are set to “L” level to stop the boosting operation by the booster circuit (5), and the switching circuit is turned “OFF” to charge the bimorph drive capacitor (C ₃ ). To stop.

In # 29, it is determined whether or not the time T required from # 23 to # 26 measured by the built-in timer is a predetermined time T ₁ or more. Then, if the measured time T is the predetermined time above T _1, the process proceeds to step # 31 after the exhaustion of the battery makes a warning of the battery check in # 30 as being large, the measurement time T is the predetermined time T ₁ If less than, skip # 30 and # 31
I will proceed.

In # 31, a signal indicating the start of the distance measuring operation is output from the output terminal of the microcomputer (1) to the distance measuring circuit (13).
At 32, a signal indicating the start of the photometry operation is output to the photometry circuit (2), and at # 33, the time required for each measurement is waited. Further, the microcomputer (1) reads the film sensitivity Sv from the film sensitivity reading circuit (3) at # 34, reads the photometric value Bv from the photometric circuit (2) at # 35, and Ev = Bv + S at # 326.
The exposure value Ev is calculated by calculating v. Next, the microcomputer (1) reads the distance measurement value from the distance measurement circuit (13) at # 37, and calculates the pulse number N1 required for ratchet drive according to this distance measurement value at # 38.

Next, in # 39, the exposure mode selected by operating the mode switches (S ₆ ) and (S ₇ ) is determined. If it is the normal mode, proceed to # 41 to execute the normal mode subroutine, and the aperture priority mode. Then # 40 to # 42
After that, the aperture priority mode subroutine is executed, and if it is the shutter speed priority mode, the subroutine from # 40 to # 43 is executed and the shutter speed priority mode subroutine is executed.

These three subroutines are shown in FIGS. 13 (a) (b) (c).
Are shown respectively. First, in the normal mode, in the flow of FIG. 13 (a), it is determined in step S1 (hereinafter abbreviated as step) whether the exposure value Ev is 8.0 or more. The exposure time T ₃ corresponding to the program line (b) in FIG. 11 is obtained from Ev. Furthermore, in S3, K ₁ is set as the timing T ₂ for causing the xenon tube (37) of the flash circuit (11) to emit light, which is longer than the time t ₃ shown in FIG. 11, and this normal mode is set in S7. Set the normal mode flag (NMF) shown to "1" and return. On the other hand, if the exposure value (Ev) is less than 8.0 in S1, the flag (FLF) indicating the flash photography mode is set to "1" in S4.
Then, in S5, the aperture value required for flash photography is determined from the distance measurement value based on the flashmatic principle (the flash emission amount is constant here). Then, the time T ₂ corresponding to this aperture value is obtained from the program line (b) in FIG. 11, the exposure time T ₃ at this time is set to 1/30 seconds in # 6, and the normal mode flag (NMF) is set in S7. Set to "1" and return.

When the shutter speed priority mode is set, the 13th
In FIG. 11B, it is determined in S11 whether the exposure value Ev is 7.5 or more. Then, when the exposure value Ev is 7.5 or more, in S12, the exposure time T ₃ is obtained according to the exposure value Ev along the program line (a) shown in FIG. The timing T ₂ for determining the timing of flash light emission in S13 is set to K ₁ in the same manner as described above, and then returns the set shutter speed priority mode flag indicating the shutter speed priority mode (SMF) to "1" in S17. On the other hand, if the exposure value Ev is less than 7.5, S14
In flag indicating the flash photographing mode (FLF) is set to "1", the time T ₂ in accordance with the distance measurement value in S15 obtained from the FIG. 11 program lines (a), the exposure time T ₃ in S16 1 Set to / 30, S
Set the flag (SMF) at 17 and return.

Further, in the aperture priority mode, S2 in FIG.
In 1 it is determined whether the exposure value Ev is 9.0 or more. Then, when the exposure value Ev is 9.0 or more, the exposure time T ₃ is determined based on the program line (c) of FIG. 11 from the exposure value Ev in S22, and S2
At 3, the flash emission timing T _{2 is set} to K ₁ and the process returns. If the exposure value Ev is less than 9.0 in S21, the flag (FLF) indicating the flash photography mode is set to "1" in S24, and S25
The time T ₂ is set according to the measured distance with the program line (c) in FIG.
After obtaining more, the exposure time T _{3 is set} to 1/30 in S26 and the process returns. Here, the method of obtaining the exposure time T ₃ from the calculated exposure value Ev and the timing T _{2 of the} flash emission from the distance measurement value
As a method for obtaining the value, a table (memory) having the exposure value Ev and the distance measurement value as parameters is prepared, and the time T _{3 is} calculated from the table according to the calculated exposure value and the read distance measurement value. , T ₂ should be read respectively.

Returning to FIG. 12, after the exposure time T ₃ and the flash emission timing T ₂ are obtained, the microcomputer (1) returns to # 44.
It is determined whether or not the flag (FLF) indicating the flash photography mode is set, and if it is set, the process proceeds to # 45 to determine the charge completion signal from the voltage detection circuit (BC ₂ ). Then, when charging of the flash emission capacitor (C ₆ ) is not completed, the output terminal (O
P ₁₀₎ to "H" level to to the switching circuit (8) in the "ON" to initiate the boost capacitor (C _6), and the output terminals # 47 (OP ₂₎ to "H" to the to the booster circuit Start the step-up operation of (5), output a low brightness warning signal at # 48, and then output at # 45.
And wait for the capacitor (C ₆ ) to be fully charged.

When charging of the flash light emitting capacitor (C ₆ ) is completed, the output terminals (OP ₂ ) and (OP ₁₀ ) are set to the “L” level by moving to # 49 and # 50, and the boosting operation of the booster circuit (5) is performed. At the same time as stopping, the switching circuit (8) is turned off.
Then, at # 51, the output of the low brightness warning signal is stopped, and #
Go to 52. Even if the flag (FLF) indicating the flash shooting mode is not set in # 44, the process proceeds to # 52 to display that shooting is possible, and in # 53, the release switch (S ₂ )
Wait for is turned on. Then, when the release switch (S ₂ ) turns on, the switches (S ₁ ) are pressed with # 54 and # 55.
Disable interrupts from the interrupt terminals (INT ₁ ) and (INT ₂ ) by (S ₀ ), and proceed to the # 56 “lens drive” subroutine.

This "lens drive" subroutine is shown in Fig. 14,
To explain, first, the output terminal (OP ₁₂ ) of the microcomputer (1) is set to the “H” level in # 100, and the output terminal (O 2) is set in # 101.
P ₁₃₎ the number of pulses N1 generated from, and return the output terminal in a # 102 finishes generating (OP ₁₂₎ to # 57 of Fig. 12 as "L".

Next, the microcomputer (1) proceeds to the "AE" subroutine at # 57. This flowchart is shown in FIG. 15 and explained. First, at # 200, the output terminal (OP ₈ ) is set to the “H” level, and the exposure control bimorph drive element (Bi ₁ ) is connected to one piezoelectric element (B). The applied voltage is 0V. Next, in # 201 and # 202, the exposure mode is determined. In the normal mode, the output terminal (OP ₅ ) is set to "H" level in # 203,
In shutter speed priority mode, output terminal (O
P ₄ ) to "H" level, and if it is the aperture priority mode, # 20
The output terminal (OP ₆ ) is set to "H" level at 5 and the program line (a) shown in Fig. 11 is selected according to the selected exposure mode.
Either (b) or (c) is obtained. Then, in # 206, the shutter starts moving toward the opening and waits for the switch (S ₄ ) to be turned “ON” immediately before the start of exposure. This switch (S ₄ )
When is turned "ON", the internal timer is reset and started in # 207.

Next, # 208 and # 209, and waits for the elapse of the flash timing T ₂ and the calculated exposure time T _3, which is set. Here, when T ₂ <T ₃ , T ₂ passes earlier than T _3, so the process proceeds from # 208 to # 210, and flash light emission is performed at a timing according to T ₂ . And # 21
At 1, wait for the time T ₃ to elapse, and if T ₃ elapses, proceed to # 214 to perform shutter closing control. On the other hand, when T ₂ ≧ T ₃ , T ₃ passes earlier than T _2, so the procedure proceeds from # 209 to # 212, and the flag (FLF) indicating the flash photography mode is set.
It is determined whether or not is set. If the flag (FLF) is set in # 212 and the flash photography mode is set, the flash is fired in # 213 and the shutter closing control of # 214 and below is performed. When not in the flash photography mode,
The shutter closing control is performed without the flash emission of # 213.

In # 214, the output terminal (OP ₄ ) (O
P ₅ ) (OP ₆ ) are set to “L” level to eliminate the voltage applied to the exposure control bimorph drive element (Bi ₁ ),
Further, the output terminal (OP ₇ ) is set to the “H” level at # 215 to short-circuit the bimorph drive element (Bi ₁ ). Then, in # 216, the internal timer of the microcomputer (1) is stopped, and in # 217, the shutter is closed.

Next, in # 218, the output terminal (OP ₈ ) of the microcomputer (1) is set to “L” level, the transistor (Tr ₁₈ ) is set to “OFF”, and in # 219, the output terminal (OP ₉ ) is set to “H” level. Then, a positive voltage is applied to one piezoelectric element (A) of the bimorph drive element (Bi ₁ ) and the other piezoelectric element (B). As a result, a reverse voltage is applied to the bimorph driving element (Bi ₁ ) and the bimorph driving element (Bi ₁ ) moves in the opposite direction.
i ₁ ) is displaced. As a result, the shutter is further driven in the closing direction, and when the initial position is reached, the switch (S ₅ ) indicating this position is turned “ON”. Microcomputer (1)
Waits for this switch (S ₅ ) to turn “ON” at # 220, and when the switch (S ₅ ) turns “ON”, at # 221 the output terminals (OP ₇ ) (OP ₉ ) go to “L”. The level is turned off and the voltage application to the bimorph drive element (Bi ₁ ) is stopped, and the voltage is changed to # 58 in FIG.
Return to

Returning to FIG. 12, the microcomputer (1) subtracts the pulse number N1 required for the above driving from the pulse number N required for the reciprocating movement of the lens in # 58, newly sets it as N1, and again in # 59. Then, the procedure advances to the "lens drive" subroutine shown in FIG. When the "lens drive" subroutine is completed in # 59, the microcomputer ( ₁ ) turns the photometry switch (S ₁ ) to "O" in # 6.
If it is not "ON", it outputs a signal to start winding one frame of film to the motor control circuit (4) at # 61 and finishes winding at # 62. wait. Then, when the switch (S ₃ ) indicating the end of the winding of one frame is turned “ON”, the signal for instructing the stop of the hoisting motor is output to the motor control circuit (4) in # 63 and the switch (# 64) The interrupt by S ₀ ) (S ₁ ) is permitted, and the routine proceeds to the “S ₁ OFF” routine of # 6 and below.

Here, in the above-mentioned embodiment, the endless type ratchet drive is used to drive and return the lens to a predetermined position. However, another embodiment shown below uses the lens driving mechanism shown in FIG.
That is, this mechanism uses the ratchet drive to drive the lens to a predetermined position, which is the same as the previous embodiment,
When returning the lens, the feed claw lever (31) pushes the reverse rotation prevention lock lever (33) to release the lock, and the lens is returned by the force of the spring (32). It is a thing. When unlocking the locking lever (33), a driving force larger than the normal driving force is required because a driving force larger than the normal driving force is required.
It is configured to add Va + Vb to the bimorph drive element (Bi ₂ ).

FIG. 16 shows the configuration of a lens drive circuit for executing this. Compared with the configuration shown in FIG. 9, the configuration shown in FIG.
Capacitor (C ₇ ) and transistor (Tr ₃₀ ) (Tr ₃₁ )
(Tr ₃₂ ) is added, and output terminals (OP ₂₀ ) (OP ₂₁ ) are also added to the microcomputer (1). The operation of this lens drive circuit is shown in FIG. 17 and FIG.
The description will be made with reference to the modified part of the flowchart in FIG. The changed parts are # 56 to # 59 in FIG. 12 and the “lens driving” subroutine shown in FIG. First, steps # 56 to # 59 in FIG. 12 are changed as shown in FIG. First, in # 56 ', the process proceeds to a "lens drive" subroutine to drive the lens to a predetermined position, in # 57' the "AE" subroutine is executed to perform exposure control, and in # 58 ', the exposure is finished. Set the flag (AEEF) and proceed to the "lens drive" subroutine again at # 59 'to reset the lens. Other operations are the same as those in the flowchart of FIG.

On the other hand, in the "lens drive" subroutine shown in FIG. 18, it is first determined at # 300 whether the flag (AEEF) indicating the end of exposure has been set. If not, # 30
At 1, the output terminal (OP ₂₀ ) of the microcomputer (1) is set to "H" level, the transistors (Tr ₃₀ ) (Tr ₃₁ ) are set to "ON", and at # 302, the output terminal (OP ₁₂ ) is set to "H" level. And then # 3
In 03, generate N1 number of pulses from the output terminal (OP ₁₃ ),
At 304 and # 305, the output terminals (OP ₁₂ ) and (OP ₂₀ ) are set to the “L” level, driving is completed, and the process returns. # 300
# 306 when the flag (AEEF) is set in
Then, the output terminal (OP ₂₁ ) is set to the “H” level, the transistor (Tr ₃₂ ) is turned on, and the voltage applied to the fixed end of the bimorph drive element (Bi ₂ ) is set to 0V. Next, at # 307, the output terminal (OP ₁₃ ) is set to the “H” level, and a voltage of Va + Vb is applied to the other end of the bimorph drive element (Bi ₂ ) to increase the displacement amount. In # 308, the time for driving the bimorph drive element (Bi ₂ ) by this displacement is waited, and in # 309, the output terminal (OP ₁₃ ) is set to the “L” level, and the bimorph drive element (Bi ₂ ) is set.
₂ ) Stop applying voltage to. Then, at # 310, the output terminal (OP ₁₂ ) is set to the “H” level, and the bimorph drive element (Bi
₂ ) is short-circuited, and the displacement of the bimorph drive element (Bi ₂ ) is restored. Wait for the time required for this displacement in # 311 and then set the output terminal (OP ₂₁ ) to the “L” level in # 312. To turn off the transistor (Tr ₃₂ ). Furthermore, applying a reverse voltage to the output terminal (OP ₂₀₎ in # 313 in the bimorph driving element in the "H" level (Bi _2), the amount of displacement is further driven in the reverse direction to the bimorph driving element (Bi ₂₎ Return as close to "0" as possible.

Further, in the above embodiment, the bimorph driving capacitor is boosted when the photometric switch (S ₁ ) is "ON", and the time required for this boosting is measured to determine the degree of battery consumption. However, in another example shown below,
When the release switch (S ₂ ) is “ON”, the bimorph driving capacitor is boosted.

Here, since the battery voltage is not stable immediately after the shutter release by "ON" of the release switch (S ₂ ),
It is not desirable to determine the degree of battery consumption by linking the release switch (S ₂ ) to “ON”. Therefore, in order to detect the voltage of the battery, another voltage detection circuit (38) is used in this embodiment.
To provide. A block diagram of the circuit to which this is added is shown in FIG. 19, and this flowchart is shown in FIG. The flowchart of FIG. 20 has two changes compared to that of FIG. One place is to add # 21a and # 21b after # 21,
The voltage of the battery is detected by inputting the signal from the voltage detection circuit (38) at 21a.
21b is a point to warn of low voltage. Therefore, the 12th
# 22 to # 30 in the figure have been deleted. The remaining one place is that after # 55 after the shutter release, a subroutine of "bimorph boosting" for boosting the bimorph driving capacitor is added as # 55a. The details of this subroutine are shown in FIG.

In the "bimorph boosting" subroutine of FIG. 21, first, in # 400, the output terminal (OP ₁₁ ) of the microcomputer (1) is set to "H" level and the switching circuits (6) and (7) are set to "ON" to set the bimorph. Boosting of the driving capacitors (C ₂ ) (C ₄ ) (C ₅ ) is started, and then the output terminal (C ₂ ) is set to “H” level in # 401 to start boosting operation of the booster circuit (5). . Then, in # 402, it waits for the charge completion signal to be sent from the voltage detection circuit (BC ₁ ). If this charge completion signal is input, the microcomputer (1) outputs the output terminal (OP ₂ ) in # 403. "L"
Level to stop the boosting operation of the booster circuit (5),
At 404, the output terminal (OP ₁₁ ) is set to “L” level, the switching circuits (6) and (7) are set to “OFF”, and the boosting of the bimorph drive capacitors (C ₂ ) (C ₄ ) (C ₅ ) is stopped. And return.

Next, another embodiment of the exposure control circuit (9) shown in FIG. 8 is shown in FIG. In the embodiment shown in FIG. 9, the exposure control bimorph drive element (Bi ₁ ) is used by being displaced from the displacement amount “0”. For this, a bimorph drive element (Bi ₁ )
A reverse voltage is applied to and the amount of displacement is "0" due to hysteresis.
The amount that does not return to the position (initial position) is corrected. Therefore, in the embodiment shown in FIG. 22, the amount of displacement due to the hysteresis that remains when the initial position is short-circuited after applying 200V to the bimorph drive element (Bi ₁ ) (point a in FIG. 7 (a)) ) And a displacement from it is used to drive the shutter.
For this reason, a constant voltage is applied to the bimorph drive element (Bi ₁ ) before the shutter release to displace it to a specific position in advance, which eliminates the influence of the change in hysteresis displacement due to the change in applied voltage. That is what it does. A circuit diagram for achieving this is shown in FIG. 22, and this flowchart is shown in FIGS. 23, 24 and 25.
The operation of the circuit shown in each of the drawings and shown in FIG. 22 will be described with reference to this flowchart.

Differences in the circuit diagram of FIG. 22 from the circuit diagram of the previous embodiment shown in FIG. 8 will be described. First, in the exposure control circuit of this embodiment, the bimorph drive element (Bi ₁ )
The transistor (Tr ₄₀ ) is connected in parallel to
The transistors (Tr ₁₇ ) (Tr ₁₈ ) (Tr ₁₉ ) shown in the figure have been deleted. Further, in the present embodiment, the voltage detection circuit for detecting a charging voltage of the bimorph driving capacitor (C ₃₎ and (BC _3), the transistor for controlling the power supply to the charging detection circuit (BC ₃₎ (Tr ₄₁₎ And are newly provided.
And this voltage detection circuit (BC ₃ ) is a capacitor (C ₃ )
When the charging of is completed, it sends the charging completion signal to the input terminal (IP ₁₁ ) of the microcomputer (1). Also a transistor (Tr ₄₀ )
(Tr ₄₁ ) are the output terminals (O
It is controlled by P ₇ ) (OP ₈ ). Then, a microcomputer (1) for controlling the transistor (Tr ₁₉ ) shown in FIG.
The output terminal (OP ₉ ) of is omitted.

First, comparing the flow chart of FIG. 23 with the flow chart of FIG. 12, after # 30, a “bimorph reset” subroutine for resetting the bimorph drive elements (Bi ₁ ) (Bi ₂ ) was provided as # 30a. Is only different. This subroutine is shown in FIG. First, the 24th
In the "Bimorph reset" subroutine shown in the figure, the voltage detection circuit is turned on by setting the output terminal (OP ₈ ) of the microcomputer (1) to "H" level at # 500 to turn the transistor (Tr ₄₁ ) "ON". Power is supplied to (BC ₃ ) to detect the voltage. This detection voltage is a voltage required to move the bimorph drive element (Bi ₁ ) to the above-mentioned initial position. Then, in # 501, the output terminal (OP ₄ ) is set to the “H” level, the transistors (Tr ₁₁ ) and (Tr ₁₂ ) are turned on, and the voltage is applied to the bimorph drive element (Bi ₁ ) via these transistors. Apply bimorph drive element (Bi ₁ )
Drive. And in # 502, voltage detection circuit (BC ₃ )
Waits for the charge completion signal from the input terminal (IP ₁₁ ) to be input, and when this signal is input, the output terminals (OP ₄ ) (OP ₈ ) are sequentially turned to the “L” level at # 503 and # 504. Then, the voltage application to the bimorph drive element (Bi ₁ ) is stopped, and the voltage detection circuit (BC ₃ ) is turned “OFF” to return.

Further, in the present embodiment, the number corresponding to # 57 in FIG.
The contents of the "AE" subroutine shown in # 57 of Figure 23 are changed. The subroutine of "AE" in this embodiment is
Shown in Figure 25. The subroutine "AE" shown in FIG.
It is almost the same as the subroutine shown in the figure, except that
First, since the reverse voltage is not applied to the bimorph drive element (Bi ₁ ), # 200 and # 218 to # 220 are deleted accordingly. Further, in this embodiment, in order to set the bimorph drive element (Bi ₁ ) to the initial position,
The switch (S ₅ ) for detecting the return of the bimorph drive element (Bi ₁ ) to the initial position is not necessary and is not monitored. Along with this change, resetting the output terminal (OP ₉ ) of the microcomputer (1) to "L" at # 221 is also deleted.

Here, in the lens driving mechanism using the endless type ratchet shown in FIGS. 4 (a) and 4 (b) and this control, it is necessary to reciprocate the lens once to return the lens to the initial position. The bimorph drive element (Bi ₂ ) is driven by an amount corresponding to the number of pulses N corresponding to the number of ratchet feeds subtracted from the number of pulses N1 corresponding to the number of feeds required for focus adjustment and driven, This is done by sending a ratchet. However, if the modified example shown in FIG. 6 is used, since the switch (34) for detecting that the lens has been returned to the initial position is provided,
When the switch (34) is turned “ON”, the driving of the bimorph drive element (Bi ₂ ) may be stopped and the movement of the lens may be stopped.

FIG. 26 and FIG. 27 show a modification of the flow chart necessary for controlling this. First, FIG. 26 shows only the changes in the flow chart shown in FIG. 12, the # 58 is deleted as compared with the embodiment shown in FIG. 12, and an exposure completion flag (AEEF) is set instead. The only difference is that step # 58a is added. Further, FIG. 27 shows a modification of the “lens driving” subroutine shown in FIG.

Explaining the "lens drive" subroutine shown in FIG. 27, first, in # 300, it is determined whether or not the exposure completion flag (AEEF) is set, as in the flow shown in FIG. If this flag (AEEF) is not set, the process proceeds to # 302, # 303, # 304. Since this operation is the same as that of the previous embodiment shown in FIG. 18, its explanation is omitted. When the exposure completion flag (AEEF) is set in # 300, the output terminal (OP ₁₂ ) is set to "H" in # 314.
The level is set, and at # 315, one pulse is generated from the output terminal (OP ₁₃ ) and the ratchet is sent by one tooth. And
Switch (3 to indicate that the lens is returning to the initial position with # 316
4) It is judged whether the switch is "ON", and this switch (34)
If is not "ON", go back to # 314
Repeating the operation of the ~ # 316, when the switch (34) is turned "ON", the output terminals (OP ₁₂₎ and then returns to the "L" level. At this time, it is necessary to provide the microcomputer (1) shown in FIG. 1 with an input terminal for detecting "ON" or "OFF" of the switch (34).

Here, in another embodiment of the exposure control circuit shown in FIGS. 22 to 25, a predetermined voltage is applied to the bimorph drive element (Bi ₁ ) in order to make the initial position constant.
However, in the modification shown below, the bimorph drive element (Bi
_As a method of making the initial position of ₁ ) constant, first, a constant voltage is applied to temporarily displace the bimorph drive element (Bi ₁ ) from “0” shown in FIG. The initial position is always kept constant by returning to the hysteresis position with respect to the applied voltage by short-circuiting to.

Therefore, the applied voltage needs to be equal to or higher than the voltage (point c in FIG. 7 (a)) required to drive to the hysteresis position (point a in FIG. 7 (a)) having the maximum voltage used. is there. Of course, this voltage depends on the type of bimorph drive element used and the maximum voltage used.

The exposure control circuit required to implement this method is
It is the same as the figure, and the flowchart showing the operation of the microcomputer (1) is also the same in FIGS. 23 and 25. The difference is that
This is a subroutine of "bimorph reset" in FIG. 24 and is shown in FIG.

In the flowchart of FIG. 28, first in # 500, the microcomputer (1) sets the output terminal (OP ₈ ) to the “H” level to turn on the voltage detection circuit (BC ₃ ), and in # 501, outputs the output terminal (OP). ₄₎ in the "H" level to start charging of the capacitor (C _3). Then, in # 502, the voltage detection circuit (B
C ₃₎ by waiting for the completion of charging is detected in the capacitor (C _3), if the charging voltage is a predetermined voltage of the capacitor (C _3), # 503, the output terminals # 504 (OP ₄₎ ( Turn OFF each OP ₈ ) and wait for the bimorph drive element (Bi ₁ ) to be displaced by a predetermined displacement amount in # 505. And
In # 506, the output terminal (OP ₇ ) is set to "H" level to short-circuit the bimorph drive element (Bi ₁ ), and in # 507, wait for the time to return to the predetermined hysteresis position, then in # 508, output terminal Set (OP ₇ ) to "L" level and return.
The charging voltage at this time may be the voltage as described above. When applying the maximum voltage to be used to the bimorph drive element (Bi ₁ ), the voltage detection circuit (BC ₃ ) shown in Fig. 22 should be used.
Also, the transistor (Tr ₄ ) may be deleted, and # 500 and # 504 in FIG. 27 may be deleted in the flowchart. At this time, as shown in FIG. 4 (a), the shutter is locked so as not to open by the protruding portion (29c) of the cam ring (29) provided in the lens driving mechanism.

Effects of the Invention As described in detail above, the camera according to the present invention changes the current for charging, the bimorph driving element for controlling the opening and closing of the shutter that also serves as the diaphragm, the charging means for charging the bimorph driving element. And a current adjusting means, which is configured to change the exposure program diagram by changing the charging current of the bimorph driving element, and by having such a configuration, the bimorph driving element The exposure program can be changed with a very simple structure by changing the displacement speed of the bimorph drive element by changing the charging current of the.

[Brief description of drawings]

FIG. 1 is a block diagram showing an electric circuit according to an embodiment of the present invention, FIG. 2 is a front view showing an exposure control mechanism thereof, and FIG. 3 (a) is an enlarged side view showing an essential part thereof. 4B is a top view, FIG. 4A is a front view showing the lens drive mechanism, FIG. 4B is a side view thereof, and FIG. 5 is a front view showing another embodiment of the lens drive mechanism. 6 and 6 are front views showing still another embodiment of the lens driving mechanism, FIG. 7 (a) is a graph showing characteristics of the bimorph driving element, and FIG. 7 (b) is a configuration of the bimorph driving element. FIG. 8 is an enlarged view, FIG. 8 is a circuit diagram showing the constitution of the exposure control circuit and the switching circuit of the embodiment shown in FIG. 1, FIG. 9 is a circuit diagram showing the constitution of the lens drive circuit thereof, and FIG. 10 is its flash circuit. Circuit diagram showing the configuration of
FIG. 11 is a program diagram showing the exposure program of this embodiment, FIG. 12 is a flow chart showing the operation of the microcomputer of this embodiment, and FIGS. 13 (a), (b), and (c) are selected by each exposure program. FIG. 14 is a flowchart showing a subroutine of “lens driving”, FIG. 15 is a flowchart showing a subroutine of “AE”, and FIG. 16 is another lens driving circuit. FIG. 17 is a circuit diagram showing an embodiment, FIG. 17 is a flowchart showing changes from the flowchart of FIG. 12 in the embodiment, FIG. 18 is a flowchart showing a subroutine of “lens driving”, and FIG. FIG. 20 is a block diagram showing the entire electric circuit of the embodiment, FIG. 20 is a flow chart showing the operation of the microcomputer, and FIG. 21 is its "bimorph boosting" subroutine. 22 is a flow chart, FIG. 22 is a circuit diagram showing another embodiment of the exposure control circuit, FIG. 23 is a flow chart showing the operation of a microcomputer for using the exposure control circuit of FIG. 22, and FIG. 24 is its "bimorph reset". 25 is a flow chart showing a subroutine of "A".
FIG. 26 is a flow chart showing a subroutine of "E", FIG. 26 is a flow chart showing a change from FIG. 12 in the flow chart of the microcomputer of another embodiment using the lens drive mechanism of FIG. 6, and FIG. 27 is its "lens drive". FIG. 28 is a flowchart showing a subroutine of “Bimorph reset” of still another embodiment. (Bi ₁ ) (Bi ₂ ): Bimorph drive element, (1): Charging means, current adjusting means.

Front page continuation (72) Inventor Michihiro Iwata 2-30 Azuchi-cho, Higashi-ku, Osaka-shi, Osaka, Osaka, Osaka International Building Minolta Camera Co., Ltd. (72) Fumiyo Ishido 2-30 Azuchi-cho, Higashi-ku, Osaka-shi, Osaka Kiyoshi Shin Kitagawa, Minora Camera Co., Ltd. (72) Inventor Tsuji Kanbo, 2-30 Azuchi-cho, Higashi-ku, Osaka-shi, Osaka

Claims (4)

[Claims] 1. A bimorph drive element comprising: a bimorph drive element for controlling opening and closing of a shutter that also serves as an aperture; a charging means for charging the bimorph drive element; and a current adjusting means for changing a current for charging. A camera having a bimorph drive element, which is configured to change an exposure program diagram by changing a charging current. 2. The current adjusting means includes an exposure mode selecting means for selecting one of at least two or more exposure modes,
A camera having a bimorph drive element according to claim 1, further comprising a current setting means for setting a charging current according to a selected exposure mode. 3. The current setting means is configured so as to increase the charging current if the selected exposure mode is a mode in which the shutter speed is emphasized. A camera having a bimorph drive element. 4. A current cutting means for cutting a charging current of a bimorph drive element when a shutter which also serves as an aperture reaches an open aperture state. With a bimorph drive element of.