JP2618511B2 - camera - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera, and more particularly to a mirror for rotating a reflex mirror in a single-lens reflex camera to a finder observation position and an exposure retract position by rotating a motor in one direction. The present invention relates to a camera having a driving mechanism.

2. Description of the Related Art Conventionally, in a mirror driving mechanism of a single-lens reflex camera, a method of rotating a movable mirror by one-way rotation of a motor is disclosed in JP-A-63-169632.

In this method, the movable mirror is rotated by a spring force from an exposure retracting position (hereinafter, referred to as a mirror-up position) to a finder observation position (hereinafter, a mirror-down position), and is rotated from a mirror-down position to a mirror-up position. This is performed by the driving force of the motor while resisting the spring force of the spring force.

[Problems to be Solved by the Invention] However, in a camera having such a mirror driving mechanism, some difficulties have been pointed out. One of the drawbacks is that a power supply voltage is reduced due to consumption of a battery used as a power supply. Fluctuates and the rotation speed of the motor changes, so the amount of overrun after applying the electric brake to the motor is large when the voltage is high and small when the voltage is low, and the mirror down stop phase of the movable mirror is maintained stably. The point is that you cannot do that.

Another drawback is that when a moving object prediction autofocus mode such as that proposed in JP-A-1-107224 is adopted as the autofocus mode in recent years, it is important to shorten and stabilize the release time lag. The conventional mirror driving mechanism has not always satisfied such a demand.

SUMMARY OF THE INVENTION An object of the present invention is to provide a camera that solves the above-described conventional problems, minimizes the fluctuation of the mirror-up time due to a change in power supply voltage, and realizes a short and stable release time lag. .

[Means for Solving the Problems] A camera for achieving the object of the present invention comprises a movable mirror rotatable between a finder observation position and an exposure retracting position,
A movable mirror operating means for operating the movable mirror between the two positions; a cam member for driving and controlling the movable mirror operating means; a motor for driving the cam member; A phase detecting means having a plurality of energization stop phases for stopping energization of the motor before reaching a stop phase position for stopping and holding the movable mirror at the viewfinder observation position, and driving the cam member. Means for selecting the plurality of energization stop phases according to the voltage of the power supply battery of the motor.

[Operation] In the camera configured as described above, in order to stop the cam member at a predetermined stop phase position, the phase detection means has a plurality of energization stop positions for stopping the energization of the motor and operating the brake. Therefore, the timing of stopping power supply can be changed according to the voltage of the power supply battery of the camera, which is the drive power supply for the motor and the like.

EXAMPLES Hereinafter, the present invention will be described in detail based on examples shown in the drawings.

FIG. 1 is a side view showing an embodiment of the camera of the present invention.
A mirror-down state is shown, and a photographing lens (not shown) is disposed on the left side in the drawing, and the subject light reflected by the movable mirror is reflected upward in the drawing and is guided to a finder optical system (not shown).

A movable mirror 16 is housed in a mirror box (not shown), and pivots 16b protruding from both sides on the base end side are rotatably supported by bearings of the mirror box.
Can be rotated between the mirror down position and the mirror up position shown in FIG. 5, and are respectively positioned at the mirror down position and the mirror up position by stoppers (not shown). A drive pin 16a for transmitting a driving force for raising and lowering the mirror is projected from the movable mirror 16 through a long hole (not shown) formed on a side surface of the mirror box. The rotating mirror 16 is rotated by the second lever 12 to be engaged, which will be described later.

As shown in FIG. 2, when the mirror 16 is in the mirror-down state, the movable mirror 16 is in contact with the stopper 31 to form a mirror-down position. The movable mirror 16 is rotatably provided on its rear side via the pivot 16c. The sub-mirror 25 rotates about the pivot 16c to a position where it contacts the stopper 32 as shown. The central luminous flux of the subject light on the optical axis 30a entering the camera body through the not-shown photographing lens is reflected by the movable mirror 16 and travels toward the finder optical system.
And the optical axis 30c passing through the half mirror 16 provided on the movable mirror 16, and the central luminous flux of the optical axis 30c passing through the half mirror 16 is totally reflected by the total reflection mirror 27 of the sub-mirror 25 to measure the distance. Guided to unit 28. Distance unit 28
Since various proposals have been made and are well known, a detailed description thereof will be omitted. The sub-mirror 25 is rotated by the spring force of a spring 29 supported by a spring hook 16d of the movable mirror 16. One end of the spring 29 is fixed to the movable mirror 16 and the other end is in contact with the operating portion 25a of the sub-mirror 25. The spring 29 biases the sub-mirror 25 counterclockwise at the mirror-down position, and at the mirror-up position. A toggle reversing mechanism that biases the sub-mirror 25 in the clockwise direction and abuts on the rear surface of the movable mirror 16 is configured. In addition,
In order to operate the toggle inversion operation, a cam member (not shown) is required. However, since this mechanism is publicly known, illustration and description thereof are omitted. In addition, the stopper 31 that regulates the mirror-down position of the sub-mirror 25 is configured by a known adjusting mechanism such as an eccentric pin, for example, so that the mirror-down position of the sub-mirror 25 can be finely adjusted.

A mirror driving mechanism configured to drive the movable mirror 16 configured as described above will be described below with reference to FIGS.

Reference numeral 11 denotes a first lever, and 12 denotes a second lever, each of which is formed in a shape shown in FIG. 3, and a shaft hole of the second lever 12 is rotatable on a support shaft 13 formed on a side surface of the mirror box. By fitting the shaft hole 11a of the first lever 11 rotatably to the shaft portion 12a formed on the periphery of the shaft hole, the fitting length of both levers 11.12 is increased, The first lever 11 and the second lever 12 can be swung while keeping the inclination due to backlash small, and the first lever 11 and the second lever located below the first lever 11 12 can be relatively swung. Reference numeral 15 denotes a pulling spring, one end of which is hooked on a spring hook 11d of the first lever 11 and the other end of which is hooked on a spring hook 12b of the second lever 12.
Of the second lever 12 in a counterclockwise direction and the second lever 12 in a clockwise direction. The first lever 11 and the second lever 12 are moved to the first lever 11 by the spring force of the pulling spring 15.
The contact portion 11e of the lever 11 and the contact portion 12c of the second lever 12 come into contact with each other, so that relative rotation is prevented. The contact portion 11e of the first lever 11 projects toward the lower second lever 12, and the contact portion 12c of the second lever 12 has a height relationship in which the contact portion 11e contacts the corresponding contact portion 11e. The first and second levers 11 and 12c allow the user to confirm the contact and non-contact states of the contact portions 11e and 12c from a peephole 11f formed in the first lever 11. Used for charge checking.

The second lever 12 has a first arm portion 12d and a second arm portion with the drive pin 16a of the movable mirror 16 interposed therebetween at the tip end of rotation.
In the mirror-down position shown in FIG. 1, the first arm 12d abuts on the drive pin 16a so as to prevent the movable mirror 16 from rotating clockwise. As the second lever 12 rotates counterclockwise integrally with the second arm 12e, the second arm 12e
The movable mirror 16 is rotated clockwise from the mirror-down position to the mirror-up position while being in contact with 6a. When the movable mirror 16 is in the mirror-up position, the second lever
When 12 rotates clockwise, the first arm 12d
The movable mirror 16 is rotated counterclockwise while abutting on 6a.

The counterclockwise rotational force of the second lever 12 for rotating the movable mirror 16 from the mirror-down position to the mirror-up position is controlled by the spring hook 11b of the first lever 11 and the spring hook on the side surface of the mirror box. The mirror 14 is provided with the spring force of the mirror-up spring 14 having both ends hung on the portion 14a, and also for rotating the movable mirror 16 from the mirror-up position to the mirror-down position while charging the mirror-up spring 14. The movable mirror 16 in the charged state at the time of applying the clockwise rotation force of the second lever 12 and the mirror down position.
The holding release operation is performed by a mirror driving cam 8 driven by a motor, which will be described below, and a first lever 11 that contacts the cam 8.
This is performed according to the relationship with the cam protruding portion 11c.

1 is a motor and 2 is a gear fixed to the output shaft of the motor 1. A transmission mechanism 3 transmits the output of the gear 2 to the gear 4. The transmission mechanism 3 is constituted by, for example, a reduction gear train. However, since the transmission mechanism 3 is easily constituted by combining two-stage gears, the constitution is omitted. In addition, in order to drive a plurality of mechanisms by one motor in view of space in the camera body or the like, it is also possible to use the transmission mechanism 3 as a mechanism for switching drive transmission in the forward and reverse directions of rotation of the motor. .

The gear 4 is fixed to the upper end of the transmission shaft 5 and transmits the rotation of the motor 1 to the transmission shaft 5. A worm gear 6 is fixed to the lower end of the transmission shaft 5, and the worm gear 6 meshes with a helical gear 7 having a rotating shaft in the above-described mirror box.
When the motor 1 rotates in a predetermined direction, the helical gear 7 rotates only in a counterclockwise direction indicated by an arrow.

On the front side of the helical gear 7, a mirror driving cam 8 having a shape shown in the figure is provided.
Is fixed, and the mirror driving cam 8 rotates together with the helical gear 7 in the same direction.

In the mirror-down state shown in FIG. 1, the rotation of the motor 1 is stopped, and the first cam contact portion 11c of the first lever 11 is the maximum lift formed in the mirror drive cam 8 in a predetermined R shape. The first lever 11 is prevented from rotating counterclockwise by the urging force of the mirror-up spring 14 in contact with the portion 8a. As described above, the first lever 11 and the second lever 12 rotate integrally while being pulled by the pulling spring 15 in a direction facing each other to a predetermined phase angle. Part 8a
Slightly before the first cam contact portion 11c contacts the
The first arm 12d of the second lever 12 is brought into contact with the drive pin 16a so that the movable mirror 16 is located at the mirror-down position, and the first lever 12d reaches the maximum lift 8a. 11 rotates slightly clockwise against the spring force of the pulling spring 15 while overcharging the mirror-up spring 14, and the second lever 12 mirrors the movable mirror 16 with the spring force of the pulling spring 15 applied. This overcharged state, which is elastically pressed to the down position, can be confirmed from the peephole 11f formed in the first lever 11 as described above, and the contact portions 11e, 12c of both levers 11, 12 can be checked. If there is a predetermined gap, it is determined that the state is an effective overcharge state, and if it is not in contact with or within a predetermined interval, it is adjusted to a predetermined interval.

On the other hand, the helical gear 7 meshes with the helical gear 9 for charging the shutter, and rotates the helical gear 9 clockwise to charge the shutter in synchronization with the driving of the movable mirror 16. A shutter charge cam 10 is fixed to the helical gear 9. Reference numeral 17 denotes a shutter charge lever that can swing about a support shaft 17a. A roller 18 provided at one end and rotatably supported by the support shaft 17b contacts the cam surface of the shutter charge cam 10, and the other end. A roller 19 supported by a support shaft 17c provided on the shutter abuts a charge lever provided on a shutter (not shown). The shutter charge lever 17 charges a shutter (not shown) by rotating counterclockwise, and FIG. 1 holds the shutter in a state where charging is completed.

Further, a position detecting mechanism for detecting the position of the mirror driving cam 8 is provided on the back side coaxially with the helical gear 7, and this mechanism comprises a contact piece 20 fixed to the helical gear 7 and a detection pattern in which the contact piece 20 makes contact. Substrate 21 having 22, 23, 24 on its surface
It is composed of

FIG. 4 is an enlarged plan view of the substrate 21. The detection pattern 22 is supplied with the GND potential from the input section 22c, and is supplied to the signal pattern section 22a via the connection section 22b. The detection pattern 23 includes a signal pattern portion 23a, a connection portion 23b, and an output portion 23c,
The detection pattern 24 includes signal pattern parts 24a and 24b, a connection part 24c, and an output part 24d. The contact piece 20 at the mirror-down position has the signal pattern portions 22a, 23a, and 3 formed in three concentric rows on the line indicated by the contact line 20a.
24a, and determines whether or not the GND potential supplied from the detection pattern 22 is transmitted to the detection patterns 23 and 24. In the following description, as the signals of the detection patterns 23 and 24, the case where the detection pattern 22 is contacted is a _Lo level,
_Hi level. Therefore, the signal pattern portions 22a, 23
In the case where the detection pattern 23 is _Lo and the detection pattern 24 is _{Lo in} FIG. 4 (corresponding to FIG. 1) in which the detection patterns 23 and 24a are in the conductive state and the movable mirror 16 is at the mirror down position. Will be detected.

In the mirror-down position shown in FIG. 1, the first lever 11 is prevented from rotating counterclockwise by the contact between the maximum lift portion 8a of the mirror driving cam 8 and the first cam contact portion 11c. The helical gear 7 starts rotating from this state, and the first cam contact portion of the first lever 11 is rotated by a small amount of rotation.
The contact between the mirror 11c and the mirror driving cam 8 is released, that is, the holding of the movable mirror 16 is released, and the first mirror 11 becomes freely rotatable. Accordingly, the first lever 11 is rotated counterclockwise. At this time, the first lever 11
And the second lever 12 are pulled by the pulling spring 14 so that the contact portions 11e and 12c are in contact with each other and rotate integrally with each other in the counterclockwise rotation.
The second arm portion 12e contacts the drive pin 16a of the movable mirror 16, and rotates the movable mirror 16 clockwise to rotate from the mirror down position to the mirror up position. Second arm 12
FIGS. 3 (c) and (d) show the contact surface of e with the drive pin 16a.
As shown in FIG. 5 and FIG. 5, when the first cam surface 12f and the second cam surface 12g are formed and the second lever 12 starts rotating counterclockwise from the mirror-down state, first, The first cam surface 12f formed in a protruding shape comes into contact with the drive pin 16a, and rotates the movable mirror 16 clockwise. When the camera further rotates and reaches near the mirror up completion, the drive pin 16
The point of contact with a is from the first cam surface 12f to the second cam surface 12g
Move to Then, immediately after that, when the movable mirror 16 contacts the stopper (not shown), the mirror up is completed.
At this time, the second cam surface 12g has an angle to increase the holding force of the movable mirror 16 in the mirror-up state, and the movable mirror rotated to the mirror-up position by the biasing force of the mirror-up spring 14 Prevents bouncing when 16 mirrors are raised. Furthermore, even in the case where the bounce cannot be completely prevented only by the holding force of the second cam surface 12g, the first cam surface 12f acts to completely stop the bounce with a minute amount of bounce, so that the mirror can be raised in a short time. The movable mirror 16 can be stabilized.

In this mirror-up state, the sub-mirror 25 is also rotated counterclockwise by the mechanism described above, and as shown in FIG.
29 makes contact with the rear surface of the movable mirror 16.

Even after the release of the holding of the movable mirror 16 described above, the motor 1 rotates and the helical gear 7 rotates in a predetermined direction, but temporarily stops in the state of FIG.

Further, in the shutter charge, the shutter charge lever 17 rotates clockwise because the roller 18 is disengaged from the maximum lift portion of the shutter charge cam 10, while the roller 19 rotates the shutter charge lever (not shown). The charge holding state has been released. In this state,
A shutter (not shown) can perform an exposure operation.

The position detection mechanism of the mirror driving cam is in the signal detection state shown in FIG. 6 in the mirror up stop state.

The contact piece 20 is in contact with only the signal pattern portion 22a on the contact line 20a.
_Hi level.

FIG. 7 is a diagram showing a mirror-down completed state during a shutter charging operation.

At the beginning of the start of the mirror-down operation, the second cam contact portion 11g of the first lever 11 contacts the cam portion 8b of the mirror driving cam 8, and the first lever 11 rotates clockwise. The second lever 12 also rotates in the clockwise direction together with the first lever 11, and the first arm 12d of the second lever 12 comes into contact with the drive pin 16a of the movable mirror 16 to move the movable mirror 16 counterclockwise. Rotate in the direction. When the motor 1 further rotates, the first lever 11 rotates counterclockwise until the first cam contact portion 11c contacts the cam portion 8b of the mirror driving cam 8 and the movable mirror 16 contacts the stopper 31. To rotate. Seventh
The figure shows this state, in which the first cam contact portion 11c of the first lever 11 is not in contact with the maximum lift portion 8a of the mirror driving cam 8, and the motor 1 is further rotated to rotate the first lift portion 8a. Of the first lever 11 in the overcharged state, and the first cam contact portion 11 of the first lever 11 is rotated.
c is in contact with the maximum lift portion 8a of the mirror drive cam 8
As shown in the figure, the rotation of the motor 1 stops. The first
The first cam contact portion 11c of the lever 11
The state of energization of the motor 1 before contacting the maximum lift portion 8a will be described later.

Here, when the movable mirror 16 is rotated to the mirror down position, it is conceivable that the movable mirror 16 abuts against the stopper 31 and bounces. However, the first lever 11 is pulled to the overcharge position to resist the spring force of the spring 15. And rotate it,
The second lever 12 engaged with the drive pin 16a of the movable mirror 16 is restrained from bouncing by this spring force, and stops at the mirror down position in a short time.

On the other hand, the shutter charge system is a shutter charge cam
The contact between the roller 10 and the roller 18 has also started, and the shutter charge lever 17 has started to rotate counterclockwise.
Basically, the mirror-down operation is preceded, and then the shutter charge is performed. However, the overlap of the drive loads in FIG. 7 is to set the load to be substantially constant within a range where the maximum load does not increase. is there.

FIG. 8 shows a signal detection state of the position detection mechanism of the mirror driving cam 8 when the mirror down in FIG. 7 is completed. On the contact line 20a of the contact piece 20, the signal pattern portion 2
2a and 24b are in contact, and the detection pattern 23 is at the _Hi level,
The detection pattern 24 is at the _Lo level.

FIG. 9 is a chart showing signal detection states of the detection pattern 23 and the detection pattern 24 in each step during one rotation of the mirror driving cam 8.

In charging completion stopped state shown in FIG. 1 and FIG. 4, as mentioned above, the detection pattern 23, 24 are both at L _o level. Here, in the phase in which the energization of the motor 1 is started and the first cam contact portion 11c of the first lever 11 is released from the maximum lift portion 8a of the mirror driving cam 8, the detection pattern 23 changes from the Lo level. It switched to H _i level. In this phase, the movable mirror 16 starts to move up by the mirror-up spring 14, and becomes stable at the mirror-up position after a predetermined time. That is, by detecting pattern 23 is set a predetermined timer from the state switches from L _o level to H _i-level, it is possible to know the mirror lockup timing irrespective of the power state.

In parallel with this, the motor 1 continues to be energized, and the roller 18 of the shutter charge system is released from the regulation by the shutter charge cam 10, and the detection pattern 24 changes from the _Lo level.
It switched to H _i level. At this time, the power supply to the motor 1 is stopped, the terminals are short-circuited, and the motor 1 is braked to stop in the state shown in FIG.

The exposure operation is completed, the power supply to the motor 1 is started, and the seventh
Upon reaching the state of FIG, signals of the detection pattern 24 is switched from the H _i-level to L _o level. With this signal, the timing at which the movable mirror 16 and the sub-mirror 25 reach the mirror down position can be accurately known regardless of the power supply state. By providing a predetermined timer at this timing, it is possible to accurately know the timing at which the movable mirror 16 and the sub mirror 25 are stabilized. Detection pattern 24 is switched from L _o level during energization motor 1 to H _i-level, the energization of the motor 1 continues. When the roller 18 in the maximum lift range of the shutter charge cam 10 reaches, switched detection pattern 23 from H _i-level by the signal pattern portion 23a to the L _o level, the further predetermined angle, the detection pattern 24 by the signal pattern portion 24a It switched from H _i-level to L _o level. This signal change corresponds to the mirror driving cam 8 in the state shown in FIG.
In order to stop the operation, the power supply to the motor 1 is stopped, the terminals are short-circuited, and the brake is applied by two different timings: an early timing and a late timing.

That is, when the power supply voltage is high, the rotation speed of the motor 1 is high, and the mirror driving cam 8
Amount run over for even greater, braked with changes at early time points from H _i-level signal pattern 23 to L _o level, stops the mirror driving cam 8 at a predetermined position shown in Figure 1.

On the other hand, if the power supply voltage is low, since low rotational speed of the motor 1, smaller amount of overrun of the mirror drive cam 8 from braked, the H _i-level signal patterns 24
Apply brakes with late changes to _Lo level, first
The mirror driving cam 8 is stopped at a predetermined position shown in FIG.

In the present embodiment, the switching of the brake timing is performed only at two time points. However, it goes without saying that the greater the number of divisions, the more accurate the stop phase. Therefore,
The time from the start of energization of the motor 1 to the start of the mirror-up operation can be kept shorter and more stable even if the power supply voltage changes.

As described above, in this embodiment, the release time lag can be shortened and stabilized, and the mirror can be increased with respect to the transfer frame continuous increase of the fline release system as disclosed in JP-A-61-183631. This configuration is effective because it is possible to accurately grasp the stable timing.

FIG. 10 is a block diagram showing one embodiment of the control circuit of the present embodiment.

100 is a photometric switch which is turned on by a first stroke of a release button (not shown); 101 is a release switch which is turned on by a second stroke of the release button;
The signals 0 and 101 are input to a microprocessor (MPU) 102. The MPU 102 receives a shutter travel completion signal 10 from a means for detecting the completion of travel of the rear curtain of a shutter (not shown).
3. Detection pattern 2 for controlling the power supply to motor 1
Signals 3 and 24 and a film feed signal 104 from a film feed detecting means (not shown) are also input. For the photometry circuit 105 and the distance measurement circuit 106, information on the operation timing is sent from the MPU 102, and the respective outputs are transferred to the MPU 102. The motor 1 and the film feed motor 107 are motor drivers 108 and 109, respectively.
Is driven by the signal of the MPU 102 through the. These motor drivers 108 and 109 have a bridge circuit capable of switching the motor 1 and the film feed motor 107 between forward and reverse energization and switching to an electric brake state forming a short circuit. When the shutter (not shown) is operated, the front curtain (not shown) is started by energizing the shutter front curtain magnet 110 by the signal of 102, and the MPU 102
The second curtain is started by energizing the shutter rear curtain magnet 111 in response to the signal. The interface with the photographic lens camera body (not shown) is not mechanically connected, but is only electrical communication between the MPU 102 and the lens control circuit 112 on the camera body side. However, the power for driving the photographing lens is supplied from the camera body.

The taking lens has an actuator 113 for driving the diaphragm and an actuator 114 for driving the focus, and the MPU 102
And the drive timing is commanded, and driven via the lens control circuit 112.

The control circuit thus configured operates according to the time chart shown in FIG.

This timing chart shows a state in which the photometry switch 100 of the first stroke of the release button (not shown) is turned on, and the second stroke is turned on and connected as it is. The feeding mode can be switched between continuous shooting and single shooting mode by mode setting means (not shown), and this time chart shows a state in which the continuous shooting mode is set. The battery check performs an actual load check in a state where power is supplied to the front curtain magnet 110 and the rear curtain magnet 111 of the shutter. The movable mirror 16 shows a change in the state of up and down. Further, this timing chart shows a state in which auto-focusing is performed while predicting the movement of a moving subject (moving object) and continuous shooting is performed.

Hereinafter, the operation of the camera of this embodiment will be described based on the flowchart shown in FIG. 12 with reference to the timing chart of FIG.

In step (hereinafter abbreviated as S) -1, if the photometry switch 100 is turned on with the power switch (not shown) turned on (S-2), the wake-up operation (S-3).
To operate various types of circuits by operating a DC / DC converter (not shown).

Next, the photometry circuit 105 and the distance measurement circuit 106 are operated (S-
4) Based on the information, the focus drive actuator 114 of the photographing lens is operated to start focus drive (S-5). The details of the distance measurement and the lens focus drive are to perform the lens focus drive by predicting the movement of the moving body as disclosed in JP-A-1-107224, and the description thereof will be omitted.

If the release switch 101 is not turned on in S-6, after a predetermined amount of lens focus driving is completed (S-7), the flow returns to S-4 to perform photometry and distance measurement. If the release switch 101 is turned on during this time, the lens focus drive is stopped (S-8), and the shooting sequence is started.

In the present embodiment, the lens focus drive is stopped halfway to emphasize the release time lag after the release switch 101 is turned on. However, the process may proceed to the shooting sequence after a predetermined amount of lens drive. Further, depending on the state of distance measurement, it may be prohibited to proceed to shooting.

At S-9, a battery check is performed. If the voltage is higher than the predetermined voltage, the BC _Hi flag is set (S-10). If the voltage is lower than the predetermined voltage, the BC _Lo flag is set (S-11).

In S-12, energization of the motor 1 is started. At the same time, a release time lag stabilization 70 ms timer for keeping the release time lag constant is started (S-
13). This timer is set on the basis of the maximum time required for driving the lens aperture, which varies according to the aperture value, and the movable mirror 16 is set so as to complete the upward movement during this time.
This keeps the release time lag constant when performing the above-described moving object prediction autofocus, thereby improving the prediction accuracy.

Then, in order to avoid a rush current when the motor 1 is started, the lens aperture is started with a delay of 15 ms (S-14) (S-15).

In S-16, signal patterns 23 for detecting the phase of the mirror driving cam 8 When turned H _i-level, and starts the mirror-up guaranteeing timer 35ms (S-17). Switching of the H _i-level signal pattern 23 is a raised starting phase of the movable mirror 16.

The energization of the motor 1 continues, and the signal of the detection pattern 24
To stop power supply to the motor 1 When switched to H _i level (S-18), applying an electrical brake (S-19).

When the aperture of the lens is completed (S-20), when the conditions of the mirror up guarantee timer of 35 ms and the release time lag stabilization timer of 70 ms are satisfied (S-21, 2).
2), energizing the shutter front curtain magnet 110 (S
-23), after a predetermined shutter time (S-24), power is supplied to the shutter rear curtain magnet 111 (S-25), and the exposure operation is performed with the front curtain and rear curtain of the shutter preceding.

When the shutter drive completion signal is input in S-26, the power supply to the motor 1 is started (S-27). And
After 15 ms (S-28), the opening operation of the lens aperture is started (S-29).

In S-30, when the opening operation of the lens diaphragm is completed, the power supply to the film feed motor 107 is started to start the film winding (S-31).

In S-32, when the signal of the detection pattern 24 is switched to the L _o level, a mirror-down position stability timer 40ms
Is started (S-33). This is a timer for ensuring that the minute vibration after the movable mirror 16 and the sub-mirror 25 reach the down position is stabilized.

Here, in the continuous shooting mode (S-34), the distance measurement and the photometry operation are started (S-35). If the mode is the single shooting mode, the process proceeds to S-36.

In S-36, when the detection pattern 36 is changed to L _o level, if BC flag stored is at H _i level in S-10, 11, multiplied by the electric brake immediately to the motor 1 (S-3
9) If the BC flag is at the _Lo level, the detection pattern 24 is _Lo
After switching to the level (S-38), the electric brake is applied to the motor 1 (S-39).

In S-40, when the film winding completion is detected by the film winding signal, the film feeding motor 107
Stop the power supply to and apply the electric brake (S-4
1).

In S-42, if the mode is the continuous shooting mode, the process returns to S-2,
If the release switch 101 is ON in S-43, S
The process proceeds to -44, and if it is off, the process returns to S-2.

If the distance measurement and the photometry are completed in S-44, the lens focus drive is started (S-45). After waiting for 15 ms (S-46), the power supply to the motor 1 is started (S-47),
The release time lag stabilization timer 70 ms is started (S-48).

Next, after waiting for 15 ms (S-49), the lens aperture operation is started (S-50).

In S51, when the signal of the detection pattern 23 is switched to the H _i-level, and starts the mirror-up guarantees timer 35ms (S-52). When the signal of the detection pattern 24 is switched to H _i level (S-53), stops the power supply to the motor 1, brakes (S-54).

At S-55, the aperture of the lens is narrowed down,
When the lens focus drive is completed in S-56, the mirror-up guarantee timer 35ms elapses in S-57, and when the release time lag stabilization timer 70ms elapses in S-58,
Returning to S-23, the energizing operation to the shutter front curtain magnet 110 is performed, and a series of operations proceeds based on the above-described flow. In continuous shooting mode, release switch 10
If 1 remains on, shooting is repeatedly executed based on the above flow.

[Effects of the Invention] As described above, according to the present invention, a plurality of motor energization stop phases are provided when the movable mirror is rotated to the finder observation position, and the brake is applied in accordance with a change in the rotation speed of the motor. Since the position can be changed, by selecting the energization stop phase according to the change in the power supply voltage of the motor, the change in the mirror up time can be reduced, the release time lag can be shortened, the stop phase of the cam member, Is obtained.

[Brief description of the drawings]

1 to 12 show an embodiment of a camera according to the present invention. FIG. 1 is a side view of a mirror driving mechanism, showing a mirror-down state. FIG. 2 is a side view of the movable mirror in a mirror down state, FIGS. 3 (a) and 3 (b) are a plan view and a sectional view of a first lever, and FIGS. 3 (c) and 3 (d) are second views. FIG. 4 is a plan view and a sectional view of a lever, FIG. 4 is a plan view of a detection pattern, and shows a state of signal detection in a mirror down stop state, FIG. 5 is a view showing a mirror up stop state of a movable mirror, FIG. 6 is a diagram showing a signal detection state in a mirror up stop state, FIG. 7 is a diagram showing the completion of mirror down of the movable mirror, FIG. 8 is a diagram showing a signal detection state in the completion of mirror down, and FIG. FIG. 10 is a diagram showing a signal detection state during operation of the camera, FIG. 10 is a block diagram showing a control circuit, FIG. 11 is a time chart showing a drive sequence, and FIG. 12 is a flowchart for explaining the operation. 1: motor, 2: gear 3: transmission mechanism, 4: gear 5: transmission shaft, 6: worm gear 7: helical gear, 8: mirror drive cam 9: helical gear 10: shutter charge cam 11, 12: lever, 13: support shaft 14: Mirror up spring 15: Pulling spring, 16: Movable mirror 20: Contact piece 22, 23, 24: Detection pattern.

Claims (1)

(57) [Claims] A movable mirror rotatable between a finder observation position and an exposure retracting position; movable mirror operating means for operating the movable mirror between the two positions; and drive control of the movable mirror operating means. A cam member to be driven, a motor for driving the cam member, and a power supply to the motor before the cam member reaches a stop phase position for stopping and holding the movable mirror at a finder observation position by cooperation with the movable mirror operating means. And a means for selecting the plurality of energization stop phases according to the voltage of a power supply battery of the motor that drives the cam member. Camera.