JPH0743774A - Previewing mechanism for camera - Google Patents

Abstract

PURPOSE:To prevent a camera from becoming large in size and to prevent the increase of cost caused by providing a previewing mechanism. CONSTITUTION:This mechanism is provided with a shutter, a mirror and a lever 13 which interlocks with a charging cam member 12 for a diaphragm, and the mechanism is constituted so that the charging cam member 12 may be set on a jump-up inhibiting position for inhibiting the mirror from jumping up and a jump-up permitting position for permitting the mirror to jump up. And at the time of performing a previewing operation, the charging cam member 12 is set on the jump-up inhibiting position while keeping the mirror on a lowered position, then, the diaphragming operation for the diaphragm is performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention lowers the diaphragm, which is normally narrowed down in conjunction with the flip-up of the mirror during shutter release, so that the photographer can confirm the depth of field when using the camera. The present invention relates to a preview mechanism for driving as it is.

[0002]

2. Description of the Related Art Conventionally, in a single-lens reflex camera, the aperture of a lens is generally held in an open position when the mirror is held in a lowered position, and is narrowed down in conjunction with the flip-up of the mirror during shutter release. Has become. Therefore, in the conventional general single-lens reflex camera, a mechanism for holding the mirror in the lowered position and the aperture in the open position before the shutter release is provided, and the holding state is released at the time of the shutter release, and the mirror bounces. The raising and the narrowing of the aperture are performed almost at the same time.

A mechanism for performing such an operation is generally a first switching means which can be set to a locking position for holding the mirror in a lowered position and a locking release position for allowing a flip-up operation. Second switching means that can be set to a locking position that holds the diaphragm of the taking lens in the open position and an unlocking position that allows the aperture operation, and a first position that sets both switching means to the locking position. , And a third switching means capable of setting the position to the second position to be set to the unlocked position. Further, normally, a lever is used as the first and second switching means, a magnet is used as the third switching means, and a magnet is turned on and off when the magnet is turned on and off.
A lever that takes a position is used, and when the magnet is energized, the first and second switching means are set to the unlocked position to drive the diaphragm and the mirror.

On the other hand, in order to perform the preview function, that is, the function for the photographer to confirm the depth of field in the viewfinder, it is necessary to narrow down the aperture while keeping the mirror down. However, in the mechanism described above, when the aperture of the lens is narrowed down, the holding of the position of the mirror in the lowered position is also released, and the subject cannot be observed, so that the photographer can confirm the depth of field. It is necessary not to cancel the holding of the position of the mirror in the lowered position when the aperture is stopped down.

Therefore, in the conventional preview mechanism, in general, another magnet is provided to hold the locked state of the mirror when the preview operation is performed, and the holding force when the magnet is energized holds the mirror in the locked position. I am trying to hold it.

[0006]

However, such a construction requires a dedicated magnet and its accompanying components, which causes the camera to become large-sized and costly. Therefore, the technical problem to be solved by the present invention is
This is to prevent the size of the camera from increasing and the cost from increasing due to the provision of the preview mechanism.

[0007]

A preview mechanism according to the present invention is capable of being set to a locking position for holding a mirror in a lowered position and a locking release position for allowing a flip-up operation.
A switching means, a second switching means that can be set to a locking position that holds the diaphragm of the taking lens at the open position and a locking release position that allows the aperture operation, and a second switching means that sets both switching means to the locking position. A preview for narrowing down an aperture in a state in which a mirror is held in a lowered position in a camera having a first position and a third switching unit capable of setting a second position for setting both switching units to an unlocked position A mechanism, in order to solve the above technical problems,
It is characterized by being configured as follows.

That is, a holding means for holding the mirror in the lowered position is provided, and the holding means is located at a flip-up prohibition position for prohibiting the flip-up operation of the mirror and a flip-up allowance position for permitting the flip-up operation of the mirror. It is configured to be configurable. Further, there is provided control means for setting the third switching means to the second position and the holding means to the flip-up prohibited position during the preview operation.

[0009]

In the above structure, when the preview operation is performed, the cam member serving as the holding unit is set to the flip-up prohibited position of the mirror while the third switching unit is set to the second position by the control unit. Is set. Then,
Although the first switching unit is in the unlocked position, the holding unit prohibits the flip-up operation of the mirror, so that the mirror is held in the lowered position. Further, at this time, since the second switching means is in the lock release position, the diaphragm can be narrowed down. Therefore, it is possible for the photographer to confirm the depth of field in the viewfinder by narrowing down the aperture to a predetermined value while holding the mirror in the lowered position.

According to the above construction, the cam member originally provided in the camera is controlled so as to be switched between two positions, and the preview operation becomes possible only by providing the lever interlocking with the cam member. It is not necessary to provide a magnet or a component accompanying it unlike the above, and therefore, it is possible to prevent the camera from becoming large and the cost from increasing.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A camera equipped with a preview mechanism according to an embodiment of the present invention shown in FIGS. 1 to 21 will be described in detail below. First, the shutter / diaphragm drive mechanism of this camera will be described with reference to FIG. In this mechanism, a large number of parts such as levers, gears and cams are arranged at overlapping positions, and each part is intricately complicated.Therefore, in the figure, the purpose is not to show the vertical relationship of each part, etc. , Different line types are used only for the purpose of clearly showing the shape of each component.

In the figure, 1 is a release magnet fixed in the body of the camera, and 2 is a lever rotatably held by an axis P1. When the release magnet 1 is energized, the release magnet 1 attracts the attracting portion 2a of the lever 2 and rotates the lever 2 counterclockwise about the axis P1 from the position shown in FIG. The release magnet 1 also serves as a magnet for stopping the diaphragm at a predetermined diaphragm value. On the other hand, the lever 2 is urged by a spring (not shown) in the clockwise direction in the figure about the axis P1 (hereinafter, all the rotation directions are the rotation directions in the drawing). The power is set to be weaker than the attraction force of the release magnet 1.

The lever 3 is rotatably held by the shaft P2 and is urged counterclockwise by a spring (not shown). However, in the state before the release, the locking portion 2b formed at one end of the lever 2 and the locking portion 3a of the lever 3 mesh with each other to prevent the lever 3 from rotating counterclockwise. Has become.

The lever 4 is rotatably held by the shaft P3, and is biased counterclockwise by a spring (not shown). Energizing the release magnet 1 causes the lever 3
When the locking portion 3a of the lever 2 and the locking portion 2b of the lever 2 are disengaged and the lever 3 rotates counterclockwise, the surface 3b of the lever 3 contacts the surface 4a of the lever 4 so that the lever 4 rotates clockwise. The urging force of each lever 3 and 4 is defined.

The lever 5 is rotatably held on the same axis P3 as the lever 4, and its tip 5a is engaged with the recess 3c of the lever 3. Therefore, when the engaging portions 2b and 3a are disengaged and the lever 3 rotates counterclockwise, the lever 5 rotates clockwise about the axis P3.

The levers 6 and 7 are both rotatably held by the shaft P4. The lever 6 is biased in the counterclockwise direction by a spring (not shown), and when the lever 6 rotates in the counterclockwise direction, the lever 7 also rotates integrally. When the release magnet 1 is energized, the tip portion 7a of the lever 7 is released.
The levers 6 and 7 are prevented from rotating by being attracted to. When the lever 3 is locked to the lever 2 as shown in FIG. 1, the levers 6 and 7 are stopped by the lever 3 and do not rotate counterclockwise even if the magnet 1 is not energized. When the lever 3 rotates clockwise, the levers 6 and 7 also rotate clockwise.

A gear 8 is arranged substantially at the center of the drawing. The gear 8 has an encoder portion 8a, an aperture stop plate portion 8b, and a locking portion 8c coaxially. Encoder part 8a
Is a substantially disk-shaped member having a large number of radially arranged slits on its outer peripheral edge, and is disposed between the light emitting and receiving parts of a photo coupler (not shown) (reference numeral 52 in FIG. 3, which will be described later) and rotates. Sometimes the photo coupler outputs a pulse signal. The aperture locking plate portion 8b is provided when the lever 7 rotates counterclockwise from the position shown in the drawing.
It is configured to stop the rotation of the gear 8 by meshing with the tip portion 7b of the. When the lever 4 is at the position shown in the figure, the locking portion 8c meshes with the locking portion 4b at the tip thereof to prevent the gear 8 from rotating in the clockwise direction.

On the other hand, the gear 8 meshes with the gear 10 through a reduction gear 9 (large and small gears) (the tip circle diameter is shown by a solid line and the pitch circle diameter is shown by a one-dot chain line for convenience of drawing). Cage, gear 10 is a lever that determines the aperture of the lens
It meshes with (not shown). The throttle lever (not shown) is biased in the throttle direction by a spring (not shown), and the throttle direction corresponds to the clockwise direction of the gear 8.

A gear 11 is arranged on the same axis as the gear 10. The gear 11 has teeth partially formed, and a cam gear member 12 including a plurality of cams and gears.
A gear 12a having the same partial teeth, which constitutes (a motor M (FIG. 3) which will be described later, is driven to rotate clockwise)
It is supposed to mesh with. When the gear 12a rotates clockwise, the gear 11 rotates counterclockwise by a certain angle. At this time, the gear 10 also rotates in the counterclockwise direction, whereby the spring of the above-described throttle lever is charged and the throttle is opened.

Reference numeral 13 denotes a lever for charging a mirror, which will be described later, which is rotatably held by an axis P5,
It is biased counterclockwise by a spring (not shown).
The end surface 13a of the lever 13 is cam surfaces 12b to 12f of the cam gear member 12 (the cam surface 12e is located on the same circumference as the input gear 12j to which the rotation is transmitted from the motor M).
Abut. When the cam gear member 12 rotates in the clockwise direction from the position shown in the drawing, the end surface 13a of the lever 13 is brought into contact with the cam surfaces 12b, 12c, 12d, 12e in order,
It rotates clockwise about the rotation axis P5 against the biasing force of a spring (not shown). Next, when the cam gear member 12 further rotates in the clockwise direction, the lever 13 moves to the end face 13
Since a comes into contact with the cam surfaces 12f, 12b in order from the cam surface 12e, the spring biasing force (not shown) rotates counterclockwise about the axis P5 to return to the state of FIG.

The cam gear member 12 has a cam surface 12i that comes into contact with the front end surface 5b of the lever 5 to rotate the lever 5 counterclockwise about the axis P3 when it rotates clockwise. As described above, since the tip portion 5a of the lever 5 is engaged with the concave portion 3c of the lever 3, the lever 5
Is rotated counterclockwise, the lever 3 moves to the axis P.
Rotate clockwise around 2. When the cam gear member 12 continues to rotate clockwise and the cam surface 12i separates from the tip surface 5b of the lever 5, the lever 3 rotates counterclockwise about the axis P2 by the urging force of a spring (not shown). Since the tip portion 5a of the lever 5 is engaged with the concave portion 3c of the lever 3, the lever 5 is rotated in the clockwise direction about the axis P3 to return to the state of FIG. 1 accordingly.

The cam gear member 12 further has a gear 12g having teeth partially formed. This gear 12g
Engages with the gear portion 18a of the shutter charge gear 18 that constitutes the shutter charge mechanism shown in FIG. The shutter charge gear 18 is biased in the clockwise direction by a spring (not shown), and when the shutter lock by the shutter lock mechanism (not shown) is released,
The spring biasing force causes it to rotate in the clockwise direction, and comes into contact with a stopper (not shown) at the position of FIG. 18 to stop. When the cam gear member 12 rotates clockwise from the position in FIG. 1, the gear 12g meshes with the gear portion 18a of the shutter charge gear 18 (FIG. 19), and the shutter charge gear 1
8 starts rotating counterclockwise against the spring biasing force (not shown). That is, the shutter is charged.

When the gear 12a further rotates in the clockwise direction, the cam surface 12h of the cam gear member 12 and the end surface 18b of the shutter charge gear 18 are slightly before the gear 12g is disengaged from the gear portion 18a of the shutter charge gear 18. Abut (Fig. 20), and the gear 12g and the gear portion 18a
Even if the engagement with is disengaged, the end surface 18b is pushed by the cam surface 12h to rotate the shutter charge gear 18 counterclockwise. While the cam surface 12h of the cam gear member 12 pushes the end surface 18b of the shutter charge gear 18, the shutter charge gear 18 enters the overcharge region, and a shutter locking mechanism (not shown) can be locked (a shutter curtain can be held). Position). At this time, when the gear 12g further rotates and the cam surface 12h disengages from the end surface 18b, the shutter charge gear 18 rotates clockwise by the amount of overcharge by the urging force of a spring (not shown), and the shutter locking mechanism (not shown). Thus, the shutter charge gear 18 is locked together with the shutter curtain at the position shown in FIG.

When the shutter charge gear 18 remains in the state shown in FIG. 17 (that is, without shutter release), when the cam gear member 12 rotates clockwise, the gear 12g of the cam gear member 12 and the gear portion 18a of the chatter charge gear 12 mesh with each other. (Fig. 21), cam surface 12h and end surface 1
Only 8b abuts. At this time, the shutter charge gear 18 is only overcharged in the counterclockwise direction, and when the cam surface 12h of the cam gear member 12 is separated from the end surface 18b of the shutter charge gear 18, the shutter charge gear 18 returns to the state of FIG. Thus, even when the shutter is locked, that is, when the shutter charge gear 18 is in the state shown in FIG. 17, the cam gear member 12
Can rotate without any hindrance.

A position detection switch (S3, S4 (FIG. 3) described later) is provided below the cam gear member 12, and in the state of FIG. 1 in which the end surface 13a of the lever 13 is in contact with the cam surface 12b, the switch is provided. In the state of FIG. 11 in which S3 is turned on and the end surface 13a is in contact with the cam surface 12e, the switch 4
Is set to turn on. Switches S3 and S
4 is configured to be alternately turned on approximately every half circumference as the cam gear member 12 rotates. That is, the position of the cam gear member 12 can be detected at two positions.

Next, the mirror mechanism will be described with reference to FIG. First, 21 is a lever rotatably held by the shaft P6. The lever 21 is biased counterclockwise by a spring (not shown), but is prevented from rotating counterclockwise from the position shown by a stopper (not shown). The lever 21 has a surface 21a that can come into contact with the surface 3d of the lever 3 described above (in FIG. 2, the shape is simplified compared to FIG. 1), and when the lever 3 rotates counterclockwise. The surface 3d contacts the surface 21a. The urging force of the lever 3 in the counterclockwise direction is
It is set to be stronger than the urging force of the lever 21 in the counterclockwise direction, and when the lever 3 rotates in the counterclockwise direction, the lever 21 rotates in the clockwise direction.

Reference numeral 22 is a lever rotatably held on the shaft P7. This lever 22 is attached to the shaft P7 by a spring 23.
Although it is urged in a clockwise direction about the center of the lever 22, depending on the position of the lever 22, the end surface 22a of the lever 22 comes into contact with the end surface 21b of the lever 21 to prevent the rotation thereof. The above-mentioned surface 13b of the lever 13 is arranged so as to face the end surface 22b of the lever 22, and when the lever 13 rotates in the clockwise direction, the lever 22
Rotates counterclockwise about the axis P7. Further, a shutter locking release lever (not shown) is arranged so as to face the end 22d of the lever 22, and when the lever 22 rotates clockwise from the position shown in the figure, the end 22d is released by the shutter member. The shutter release gear 18 is brought into contact with the stop release lever to release the shutter charge gear 18 from the locked state (state shown in FIG. 17).

Reference numeral 26 denotes a mirror, which guides the light passing through the taking lens to the finder when it is in the lowered position shown in the drawing.
At the time of shooting, it rises and retracts from the optical path from the shooting lens to the film. 27 is this mirror 26
Is a mirror holder that holds rotatably, is rotatably held on the axis P8, and rotates integrally with the mirror 26.

The lever 22 is provided with a shaft 22c, and one end of a lever 24 is rotatably held around the shaft 22c. The bent portion 24a formed on the other end side of the lever 24 is arranged to face the convex portion 27a provided on the mirror holder 27. And the lever 24
In order to urge the mirror holder 27 to the lowered position when is in the state shown in the figure, a spring 25 is hooked between the convex portion 27a provided on the mirror holder 27 and the hook 24b of the lever 24.

Next, the circuit configuration of this camera will be described with reference to the block diagram shown in FIG. First, what is shown in the center of the figure is a camera control microcomputer (hereinafter referred to as CPU) 50 as a control means for performing functions such as sequence control and exposure calculation control of the camera. It is equipped with various data buses and input / output terminals.

Reference numeral 51 is a photometric circuit for measuring the brightness of an object, which includes a photoelectric conversion element for light reception, an A / D (analog / digital) conversion section, a reference voltage source for A / D conversion, and a CPU 50.
And a data transmission / reception unit, etc., and performs photometry by light transmitted through the taking lens according to a command from the CPU 50, and calculates an aperture value and a shutter speed value at which proper exposure is obtained.

S1 is a photometric switch that is turned on in the first step of pressing down a release button (not shown) that is configured as a two-step push-down type. When the photometric switch S1 is turned on by operating the release button, the CPU 50 Photometric circuit 51
A signal for starting photometry is output to. Further, S2 is a release switch which is turned on in the second step of pressing the release button. When the release switch S2 is turned on in the release possible state, the release operation is executed by the output signal from the CPU 50. The photometric switch S1 is held in the ON state even when the release switch S2 is turned ON. As described above, S3 and S4 are position detection switches for the cam gear member 12, which are alternately turned on every half turn of the cam gear member 12.

SPV is a preview switch. The preview switch SPV is turned on when the photographer presses a preview button (not shown) in order to confirm the depth of field in the viewfinder, and is turned off when the photographer releases the button. When the preview switch is turned on, the aperture is held while holding the mirror in the lowered position. Only the narrowing operation of is performed. SSIL is a shooting mode selection switch, which is a normal shooting mode when turned off and a second shooting mode which will be described later when turned on.
The shooting mode can be switched to. Further, M is a motor, and when the motor is energized, the cam gear member 12 is configured to rotate in the clockwise direction.

RFMg is a release magnet indicated by reference numeral 1 in FIG. Further, 1 CMg and 2 CMg are magnets for holding the front curtain and the rear curtain of the shutter, respectively, and are configured to respectively hold the shutter front curtain and the rear curtain when energized. The shutter speed is the time from turning off the power to the front curtain magnet 1CMg to release the shutter front curtain, and then turning off the power to the rear curtain magnet 2CMg to release the shutter rear curtain. Equivalent to.

Reference numeral 52 is a diaphragm encoder composed of a photocoupler consisting of a light emitting diode 52a and a phototransistor 52b. When the encoder portion 8a of the gear 8 rotates, the light sent from the light emitting diode 52a to the phototransistor 52b is intermittently. Blocked, pulse signal F
P is output. RESET is a reset terminal that is pulled up to the voltage VDD by the resistor R1 and resets the CPU when the signal changes from the L level to the H level. Further, X is a crystal oscillator for giving a clock signal to the CPU 50.

The operation of the camera will be described below with reference to the flowchart. First, the sequence at the time of normal shooting is shown in FIG.
Will be explained. In this sequence, when the photometric switch S1 is turned on by pressing the release button to the first step, the brightness of the subject is measured in step # 101, and the exposure value is calculated based on the measured value to calculate the exposure value. , Determine the proper aperture value and shutter speed.
Next, at step # 102, the release switch S
It is determined whether 2 is on or off, and if it is off, the process returns to step # 101 to repeat photometry and exposure value calculation.

When the release switch S2 is turned on, the process proceeds to step # 103 and the release magnet 1 (RFMG)
Then, electricity is supplied to the shutter front curtain holding magnet 1CMG and the shutter rear curtain holding magnet 2CMG. At this time, in FIG. 1, the lever 2 has a suction portion 2a.
Is attracted by the release magnet 1 and rotates counterclockwise around the axis P1. Therefore, the locked state between the locking portion 2b of the lever 2 and the locking portion 3a of the lever 3 is released, and the lever 3 is rotated counterclockwise by the spring (not shown).

Then, the surface 4a of the lever 4 is pushed by the surface 3b of the lever 3, so that the lever 4 rotates clockwise about the axis P3 against the biasing force of the spring (not shown). Therefore, the locked state of the locking portion 8c of the gear 8 and the locking portion 4b of the lever 4 is released, and the gear 8 is clocked while the diaphragm of the photographing lens is narrowed by the biasing spring of the diaphragm lever (not shown). It rotates in the direction of rotation (Fig. 5). Also,
As the gear 8 rotates, the encoder portion 8a also rotates integrally, so that the pulse signal F from the diaphragm encoder 52 is generated.
P is output. In step # 104, this pulse F
Count P. Release magnet 1 (RF
(Mg) is energized, the lever 3 rotates and the levers 6, 7
However, since the tip 7a of the lever 7 is attracted to the release magnet 1 at this time, the levers 6 and 7 do not rotate counterclockwise.

When the gear 8 starts to rotate, next, in step # 105, the process waits until the number of pulses FP corresponding to the aperture value of the lens is counted.
Proceeding to 106, the power supply to the release magnet 1 (RFMg) is stopped. Then, the levers 6 and 7 simultaneously rotate counterclockwise around the axis P4, and the tip end portion 7b of the lever 7 meshes with the diaphragm stop plate portion 8b of the gear 8 to stop the rotation of the gear 8. It is set to a predetermined value,
The narrowing is completed. The state of the mechanism at this time is shown in FIG.

On the other hand, on the mirror mechanism side, since the lever 3 rotates counterclockwise, the surface 3d pushes down the surface 21a of the lever 21 in FIG.
Rotates clockwise about the axis P6. At this time, the locked state between the end surface 21b of the lever 21 and the end surface 22a of the lever 22 is released, and the biasing force of the spring 23 causes the lever 22 to rotate clockwise about the axis P7. Therefore, since the lever 24 moves upward in the drawing, the bent portion 24a of the lever 24 comes into contact with the convex portion 27a of the mirror holder 27 that supports the mirror 26, and the mirror holder 27 is rotated counterclockwise about the axis P8. And the mirror 26 is raised. The lever 22 is prevented from rotating when it comes into contact with a stopper (not shown). At this time,
As shown in FIG. 7, the mirror 26 is raised to a position where it is completely retracted from the optical path from the taking lens to the film surface, and the flip-up operation is completed.

When the lever 22 rotates in the clockwise direction, the end 22d of the lever 22 comes into contact with a shutter lock release lever (not shown) to release the shutter charge gear 18 from the locked state. Therefore, the front and rear curtains of the shutter are allowed to travel, but at this time, since the holding magnets 1CMg and 2CMg are still energized, the front and rear curtains do not travel and the shutter charge gear 18 Only the chimney rotates (Fig. 18). Then, in step # 107, it waits for a predetermined time t1 to elapse after the release magnet RFMg is energized. This time t
1 is the time defined so that the diaphragm is stopped down during that time and the mirror 26 is completely raised.

In step # 108, the shutter front curtain holding magnet 1CMg is de-energized and the shutter front curtain is run. Next, in step # 109, the time t2 defined as the exposure time of the film is waited for, and in step # 110, the shutter rear curtain holding magnet 2CMg is de-energized to allow the shutter rear curtain to travel and the proper shutter speed is set. To expose the film. Then, in step # 111, after the time t3 sufficient for the rear curtain of the shutter to travel, the shutter, the mirror and the aperture are charged.
At 12, the power supply to the motor M is started.

When the motor M is energized, its rotation is transmitted to the cam gear member 12 via a reduction gear (not shown), and
At, the cam gear member 12 rotates in the clockwise direction.
Then, the cam surface 12i contacts the end surface 5b of the lever 5, and the lever 5 is rotated counterclockwise about the axis P3. Since the tip portion 5a of the lever 5 is engaged with the concave portion 3c of the lever 3, when the lever 5 rotates in this way, the lever 3 rotates in the clockwise direction against a spring biasing force (not shown). Further, when the lever 3 rotates, the lever 6 rotates clockwise against the spring biasing force (not shown), and the lever 7 also rotates at the same time.
The engagement state between the front end portion 7b and the aperture stop plate portion 8b of the gear 8 is released. It should be noted that the lever 6 can be rotated further clockwise even after the tip 7a of the lever 7 comes into contact with the release magnet 1 and the lever 7 stops.

At this time, since the release magnet 1 is not already energized, when the locking portion 3a of the lever 3 exceeds the locking portion 2b of the lever 2, the lever 2 is rotated clockwise by the urging force of a spring (not shown). Rotate in the direction. When the cam surface 12i of the cam gear member 12 is separated from the tip surface 5b of the lever 5, the lever 3 tries to rotate counterclockwise about the axis P2 by the urging force of a spring (not shown). Since the locking portion 3a and the locking portion 2b of the lever 2 are engaged, rotation of the lever 3 in the counterclockwise direction is prevented.
On the other hand, since the lever 4 is biased in the counterclockwise direction about the axis P3 by the spring (not shown), the lever 3 rotates in the counterclockwise direction around the axis P2 in the clockwise direction. , Cam surface 8d of gear 8 and lever 4
The front end 4c of the locking surface 4b of the above contacts. Since the lever 3 rotates further clockwise than the position at that time, the surface 3b of the lever 3 and the surface 4a of the lever 4 are separated from each other.

When the cam gear member 12 further rotates in the clockwise direction, the gear 12a of the cam gear member 12 moves to the gear 11a.
, The gear 11 rotates counterclockwise, and the throttle lever (not shown) is charged in the aperture opening direction.
Further, when the gear 11 rotates, the gear 8 further rotates counterclockwise through the gears 10 and 9, and when the diaphragm is completely opened, the locking portion 8c of the gear 8 becomes the locking portion of the lever 4. 4b and the diaphragm is locked in the open position (Fig. 1).

While the diaphragm is being charged, the lever 13
The end surface 13a of the lever moves along the cam surfaces 12c and 12d of the cam gear member 12, whereby the lever 13 rotates in the clockwise direction about the axis P5. At this time, since the end surface 22b of the lever 22 is pushed by the surface 13b of the lever 13, the lever 22 rotates counterclockwise around the axis P7 from the position of FIG. 7, and the lever 24 moves downward accordingly. . When the lever 24 moves downward, the mirror holder 27
Rotates clockwise about the axis P8, and the mirror 2
6 will descend.

When the end surface 22a of the lever 22 exceeds the end surface 21b of the lever 21, since the surface 3d of the lever 3 has already moved upward, the lever 21 is rotated about the axis P6 by the spring biasing force (not shown). It is ready to rotate clockwise. The cam gear member 12 further rotates and the lever 13
When the end surface 13a of the lever abuts on the cam surface 12e of the cam gear member 12, the end surface 13b of the lever 13 becomes the end surface 22b of the lever 22.
Is pushed up most, and at this time, the locking surface 22a of the lever 22 further rotates counterclockwise around the axis P7 from the position shown in FIG. 2, and the lever 21 returns to the locking position shown in FIG.

When the cam gear member 12 further rotates and the end surface 13a of the lever 13 contacts the cam surface 12f of the cam gear member 12, the lever 13 is rotated counterclockwise by the urging force of a spring (not shown) about the axis P5. Rotate in the direction.
When the lever 13 rotates counterclockwise, the lever 22 rotates clockwise around the axis P7 by the urging force of the spring 23, and the locking surface 22a of the lever 22 becomes the locking surface 21b of the lever 21. When abutting, the lever 22 will be in the locked state of FIG. This completes the charging of the mirror 26.

On the other hand, when the aperture is returned to the open state and the mirror is returned to the lowered position (when the contact between the end surface 13a of the lever 13 and the cam surface 12d of the cam gear member 12 is almost finished), the cam gear member 12 is moved to the next position. The gear portion 12g meshes with the gear portion 18a of the shutter charge gear 18 (Fig. 19), and the shutter charge gear 18 is rotated counterclockwise (Fig. 2).
0), charge the shutter. When the cam gear member 12 makes about one rotation from the start of rotation, charging of the shutter is also completed, the end surface 13a of the lever 13 contacts the cam surface 12b of the cam gear member 12, and the switch S3 is turned on.

Thus, the step S113 is waited for the switch S3 to be turned on, and if this is confirmed, the process proceeds to a step # 114 to brake the motor M for a predetermined time t4. As a result, the rotation of the cam gear member 12 is stopped, and the state shown in FIG. 1 is restored. Then, in step # 115, the brake of the motor M is stopped to turn off the power, and in step # 116, the photographing standby state is set.

Next, the preview operation will be described with reference to the flowchart of FIG. The preview operation is an operation of narrowing down the aperture while keeping the mirror in the lowered position so that the photographer can check the depth of field in the viewfinder. By pressing a preview button (not shown), the preview switch of FIG. SPV turns on and boots.

When the switch SPV is turned on, the subject brightness is measured in step # 121, the exposure value is calculated by the exposure calculation, and the aperture and the shutter speed are determined. At step # 122, each magnet RFM first
Instead of energizing g, 1CMg, 2CMg, energization of the motor M is started and the cam gear member 12 is rotated clockwise. Then, the cam surface 12i contacts the end surface 5b of the lever 5, and the lever 5 rotates counterclockwise about the axis P3. When the lever 5 rotates in the counterclockwise direction, since the tip 5a of the lever 5 and the recess 3c of the lever 3 are engaged with each other, the lever 3 resists the spring (not shown) and the shaft P2.
Rotate clockwise around. When the cam gear member 12 further rotates from here and the cam surface 12i moves away from the end surface 5b of the lever 5, the lever 5 rotates clockwise by a spring force (not shown). Further, the lever 3 also rotates counterclockwise by a spring force (not shown), and the locking surface 3a of the lever 3 comes into contact with the locking surface 2b of the lever 2 again, and the lever 3
Is locked.

On the other hand, when the cam gear member 12 rotates in the clockwise direction, the cam surface contacting the end surface 13a of the lever 13 changes from 12b to 12c, 12d, so that the lever 13 is centered on the axis P5 and is not shown. Rotate clockwise against the spring force of. When the lever 13 rotates clockwise in this manner, the end surface 13b of the lever 13 contacts the end surface 22b of the lever 22, and the lever 22 counterclockwise against the biasing force of the springs 23 and 25 about the axis P7. It will rotate in the direction of rotation.

When the cam gear member 12 rotates clockwise, the gear 12a meshes with the gear 11, and the gear 11 rotates counterclockwise. Gear 10 and gear 11
In the state where the diaphragm is not running (the diaphragm is open), the gear 11 does not rotate integrally, but only the gear 11 rotates counterclockwise. When the cam gear member 12 further rotates in the clockwise direction, the gear portion 1 of the cam gear member 12
The meshing between 2a and the gear 11 is disengaged, and the gear 11 is rotated clockwise by a spring force (not shown) to return to the original state, and the state shown in FIG. 9 is obtained.

When the cam gear member 12 rotates clockwise, the cam surface 12e contacts the end surface 13a of the lever 13, and the gear 12a and the gear 11 are disengaged from each other, the switch S is released.
4 turns on. Thus, when the switch S4 is turned on is detected in step # 123, the switch S4
Is turned on, the motor M is braked for a predetermined time t5 in step # 124, and then the brake of the motor M is stopped to turn off the power in step # 125.

After the power supply to the motor M is stopped, the release magnet 1 (RFMg) is supplied with power in step # 126. At this time, in FIG. 9, the attraction portion 2a of the lever 2 is attracted to the release magnet 1 as in the case of the normal release operation, and the lever 2 rotates counterclockwise about the axis P1. Then, the locking state of the locking portion 2b of the lever 2 and the locking portion 3a of the lever 3 is released, so that the lever 3 is rotated counterclockwise by a spring (not shown). As a result, the surface 4a of the lever 4 is pushed by the surface 3b of the lever 3, so that the lever 4 rotates clockwise about the axis P3 against the spring biasing force (not shown),
The locking portion 8c of the gear 8 and the locking portion 4b of the lever 4 are unlocked. Therefore, the gear 8 rotates clockwise, and the diaphragm of the lens is narrowed down (FIG. 11). In addition,
Also at this time, the release magnet 1
The tip 7a of the lever 7 is attracted to the release magnet 1 (RFMg) by energizing (RFMg).
Does not rotate counterclockwise.

Further, since the encoder portion 8a also rotates integrally with the rotation of the gear 8, a pulse FP is output from the diaphragm encoder. In step # 127, this pulse FP is counted, and in step # 128, it is determined whether or not the number of pulses corresponding to the aperture value of the lens is counted. Then, when the predetermined number is counted, step # 1
Proceeding to 29, the power supply to the release magnet 1 (RFMg) is stopped. Then, the levers 6 and 7 simultaneously move to the axis P4.
Is rotated in the counterclockwise direction, the tip claw portion 7b of the lever 7 contacts the diaphragm stop plate portion 8b of the gear 8, the gear 8 stops, and the diaphragm of the lens is set to a predetermined value.

While the aperture is thus narrowed down, on the mirror mechanism side, the lever 3 rotates counterclockwise, so that the surface 3d pushes the surface 21a of the lever 21 in FIG. By rotating clockwise about the axis P6, the locking surface 21b of the lever 21 retracts from the locking position with the locking surface 22a of the lever 22 (FIG. 12). However, at this time, the end surface 22b of the lever 22 is different from the end surface 13b of the lever 13 unlike the case of the normal photographing.
Therefore, the mirror 26 does not rotate in the counterclockwise direction, and the mirror 26 is held in the lowered state as shown in FIG. That is, since the mirror 26 is not flipped up and only the diaphragm is narrowed down, the photographer can confirm the depth of field during this time. As described above, in the preview mechanism of this embodiment, since the preview operation can be performed by switching the position of the cam gear member 12, a dedicated actuator or the like is unnecessary, and it is possible to prevent an increase in size and cost of the camera. .

When the confirmation of the depth of field is completed, the switch SPV is turned off by releasing the preview button. When it is confirmed that the switch SPV is turned off in step # 130, the shutter front curtain holding magnet 1CMg and the rear curtain holding magnet 2CMg are energized to hold both shutter curtains in step # 131. Further, in step # 133, the motor M is energized and the cam gear member 12
Rotate clockwise. Then, lever 13
Since the end surface 13a of the above contacts the cam surface 12f of the cam gear member 12, the lever 13 rotates counterclockwise about the axis P5. While the mirror 26 was held in the lowered position during the preview operation, when the lever 13 rotates counterclockwise in this manner, the lever 22 in FIG.
Is pulled by the spring 23 about the axis P7 and rotates in the clockwise direction, the lever 24 supported by the axis 22c of the lever 22 is pushed up, and the bent portion 24a of the lever 24 becomes a convex portion of the mirror holder 27. Abut 27a,
The mirror holder 27 rotates counterclockwise around the axis P8, and the mirror 26 moves to the retracted position.

When the lever 22 rotates in the clockwise direction, the end 22d of the lever 22 comes into contact with a shutter lock release lever (not shown), and the shutter lock is released. When the shutter is released from the locked state, the shutter charge gear 18 travels as described above, but since both shutter curtain holding magnets 1CMg and 2CMg are energized, the front and rear curtains of the shutter are held. Don't drive up to When the cam gear member 12 rotates and the end surface 13a of the lever 13 comes into contact with the cam surface 12b, the switch S3 is turned on, the shutter / diaphragm drive mechanism is in the state of FIG. 6, and the mirror mechanism is in the state of FIG.

Thus, in step # 133, the switch S
When it is confirmed that No. 3 is turned on, in order to charge the mirror and the diaphragm, the power supply to the motor M is continued in step # 134, and the cam gear member 12 is continuously rotated in the clockwise direction. As a result, when the cam gear member 12 further rotates in the clockwise direction, as in the normal shooting operation,
The cam surface 12i contacts the end surface 5b of the lever 5 and pushes the lever 5, and the lever 5 rotates counterclockwise about the axis P3. Since the tip 5a of the lever 5 and the recess 3c of the lever 3 are engaged, the lever 3 rotates clockwise against the spring biasing force (not shown), and the lever 6 is not shown by the lever 3. It rotates clockwise against the urging force of. Therefore, the lever 7 also rotates clockwise about the axis P4, and the engagement state between the tip end portion 7b of the lever 7 and the aperture stop plate portion 8b of the gear 8 is released.

When the lever 3 rotates and the locking portion 3a exceeds the locking portion 2b of the lever 2, the lever 2 is rotated clockwise by a spring (not shown). When the cam surface 12i of the cam gear member 12 separates from the end surface 5b of the lever 5,
The lever 3 tries to rotate counterclockwise around the axis P2 by the urging force of a spring (not shown), but the locking portion 2b of the lever 2 engages with the locking portion 3a of the lever 3, so the lever 3 Is prevented from rotating counterclockwise. Further, since the lever 4 is biased counterclockwise about the axis P3 by a spring (not shown), the lever 3 rotates counterclockwise about the axis P2 in the clockwise direction. . Therefore, the cam surface 8d of the gear 8 and the tip 4c of the locking surface 4b of the lever 4 come into contact with each other. After that, since the lever 3 further rotates in the clockwise direction, the surface 3b of the lever 3 separates from the surface 4a of the lever 4.

When the cam gear member 12 further rotates clockwise, the gear 12a and the gear 11 of the cam gear member 12 are rotated.
Mesh with each other, the gear 11 rotates counterclockwise, and the aperture is charged in the opening direction. Further, the rotation of the gear 11 is transmitted to the gear 8 via the gear 10 and the gear 9, and the gear 8
Rotates counterclockwise. Then, when the aperture is completely opened, the engagement portion 8c of the gear 8 engages with the engagement portion 4b of the lever 4, and the aperture is held in the open state.

While the throttle is being charged, the lever 13 is driven by the cam surfaces 12c and 12d of the cam gear member 12 so as to move the shaft P to the axis P.
Rotate clockwise around 5 Therefore,
Since the end surface 22b of the lever 22 is pushed by the surface 13b of the lever 13, the lever 22 rotates counterclockwise about the axis P7 and the lever 24 moves downward. Therefore, the mirror holder 27 is pulled by the spring 25 and rotates clockwise about the axis P8, and the mirror 26
Will fall.

At this time, since the surface 3d of the lever 3 has already moved upward, the end surface 22a of the lever 22 is moved to the lever 2
The lever 21 is allowed to rotate counterclockwise beyond the end face 21b of the No. 1 unit. When the cam gear member 12 further rotates and the end surface 13a of the lever 13 comes into contact with the cam surface 12e of the cam gear member 12, the end surface 1 of the lever 13
3b is in the state in which the end surface 22b of the lever 22 is pushed up most. At this time, the locking surface 22a of the lever 22 is further rotated counterclockwise about the axis P7 as compared with the state of FIG. 2, and the lever 21 returns to the locking position of FIG.

When the cam gear member 12 is further rotated, the end surface 13a of the lever 13 is moved to the cam surface 12f of the cam gear member 12.
The lever 13 rotates counterclockwise about the axis P5. Lever 1
When 3 rotates counterclockwise, lever 22 moves spring 23
The locking surface 22a of the lever 22 is rotated clockwise about the axis P7 by the urging force of
The lever 22 is in the locking position shown in FIG.

When the diaphragm returns to the open position and the mirror returns to the lowered position, the gear 12g of the cam gear member 12 meshes with the shutter charge gear 18 next. At this time, since the shutter is not traveling because it is held by the magnets 1CMg and 2CMg, the shutter remains as it is and the gear 18
And the locking mechanism is charged. After that, lever 13
The switch S3 is turned on again when the end surface 13a comes into contact with the cam surface 12b. In step # 135,
In this way, the switch S3 is awaited to be turned on, and when it is confirmed that the switch S3 is turned on, the process proceeds to step # 136 to stop energizing the shutter curtain holding magnets 1CMg, 2CMg.

In step # 137, the brake of the motor M is operated for a predetermined time t4, thereby stopping the rotation of the cam gear member 12. At this time, the cam gear member 12 returns to the state of FIG. Next, Step # 138
Then, the brake operation is stopped and the motor is de-energized, and the photographing standby state is set at step # 139. Although not shown in the flowchart of FIG. 8,
Even if the preview button is operated to perform the preview operation again during the execution of this sequence, the preview operation is not executed unless it is confirmed that the preview switch SPV is once turned off.

In the camera of this embodiment, even when the diaphragm is narrowed down by the preview operation, the shutter release is performed when the release switch S2 is turned on by pressing the release button. The movement of the mechanism at this time is shown in the flowchart of FIG.

First, if the release switch S2 is turned on while the preview switch SPV is on,
The process jumps from the flowchart of FIG. 8 to step # 151 of the flowchart of FIG. 13, energizes each shutter curtain holding magnet 1CMg, 2CMg to hold each shutter curtain, and energizes the motor M in step # 152 to energize the cam gear member. Rotate 12 clockwise. At this time,
The end surface 13 a of the lever 13 is the cam surface 1 of the cam gear member 12.
Since it comes into contact with 2f, the lever 13 rotates counterclockwise around the axis P5 as the cam gear member 12 rotates. The mirror 26 is held in the lowered position during the preview operation, but in this case, the lever 22 is pulled by the spring 23 in accordance with the rotation of the lever 13 in the counterclockwise direction and is rotated in the clockwise direction about the axis P7. As it rotates, the lever 24 supported by the shaft 22c of the lever 22 is pushed up and the bent portion 24a of the lever 24 abuts on the convex portion 27a of the mirror holder 27.
7 rotates counterclockwise about the axis P8 and the mirror 26 moves to the retracted position. That is, the preview operation is canceled.

When the cam gear member 12 further rotates and the end surface 13a of the lever 13 comes into contact with the cam surface 12b of the cam gear member 12, the switch S3 is turned on. When it is confirmed in step # 153 that the switch S3 is thus turned on, the motor M is braked for t4 hours in step # 154, and the motor M is turned off in step # 155. After this, step # 10 in FIG.
Then, the same operation as in the normal photographing is performed.
In this case, if the release switch S2 remains on after the motor M is braked and stopped, the next preview operation is not performed even if the preview switch SPV is on. ing.

Next, using the flowchart shown in FIG. 14, the drive system switching mechanism of this embodiment (comprised of cam gear member 12, levers 13, 22, 24, springs 23, 25, motor M, etc.) The operation of switching to the second shooting mode by will be described. In normal shooting mode,
When the mirror holder 27 rotates about the axis P8 when retracted to the retracted position, the lever 22 is pulled by the spring 23 and collides with a stopper (not shown), so that relatively large noise and vibration are likely to occur. is there. With this camera,
When the sound when the mirror is retracted is annoying, such as when shooting in a quiet environment, it is possible to suppress the generation of sound or vibration by selecting the second shooting mode.

Therefore, when the photographing mode selection lever (not shown) is set to the second photographing mode selection position, the photographing mode changeover switch SSIL of FIG. 3 is turned on and the motor M is energized in step # 161 of FIG. Be started. Then, the cam gear member 12 rotates clockwise, the cam surface 12i abuts on the tip surface 5b of the lever 5, and the lever 5 rotates counterclockwise about the axis P3 against a spring (not shown). To do. Since the recess 3c of the lever 3 and the tip 5a of the lever 5 mesh with each other, when the lever 5 rotates counterclockwise, the lever 3 rotates clockwise against the urging force of a spring (not shown).

When the cam gear member 12 further rotates to disengage the cam surface 12i from the tip surface 5b of the lever 5, the lever 5 rotates in the clockwise direction about the axis P3 by the urging force of a spring (not shown). Along with this, the lever 3 also rotates counterclockwise by the urging force of a spring (not shown), and the lever 3
The locking surface 3a of 1 comes into contact with the locking surface 2b of the lever 2 again, and the lever 3 is locked.

On the other hand, when the cam gear member 12 rotates in the clockwise direction as described above, the end surface 13a of the lever 13 comes into contact with the cam surfaces 12c and 12d of the cam gear member 12 in that order. Lever 13 is axis P
It rotates clockwise about 5 as a counter force against a spring force (not shown). Further, as the lever 13 rotates in the clockwise direction, the end surface 13b of the lever 13 is changed to the end surface 22b of the lever 22.
And the lever 22 rotates counterclockwise around the axis P7 against the biasing force of the springs 23 and 25.
(Figure 10).

When the cam gear member 12 rotates in the clockwise direction, the gear 12a meshes with the gear 11, so that the gear 11 rotates in the counterclockwise direction. At this time, when the throttle is not running (charged),
As described above, the gear 10 and the gear 11 do not rotate integrally, but only the gear 11 rotates. When the cam gear member 12 further rotates in the clockwise direction, the gear 12a of the cam gear member 12 and the gear 11 are disengaged from each other, and the gear 11 rotates in the clockwise direction by a spring force (not shown) and returns to the original state.
(Figure 9).

When the cam gear member 12 rotates clockwise and the cam surface 12e comes into contact with the end surface 13a of the lever 13 and the gear 12a disengages from the gear 11, the position detecting switch S4 is turned on. In this way, the position detection switch S
When it is confirmed in step # 162 that 4 has been turned on, the motor M is braked for t9 hours in step # 163, and in step # 164, the brake of the motor M is stopped to turn off the energization, and then in step # 165. The second photographing mode standby state is entered, and the switching to the second photographing mode is completed.

Next, the switching operation from the second photographing mode to the normal photographing mode will be described with reference to the flowchart shown in FIG. When the shooting mode selection lever is set to the normal shooting mode selection position in the second shooting mode standby state shown in FIGS. 9 and 10, the switch SSIL is switched from on to off. Then, step # 171
Then, the energization of the motor M is started, the cam gear member 12 rotates in the clockwise direction, and the end surface 13a of the lever 13 that was in contact with the cam surface 12e comes into contact with the cam surface 12f. Accordingly, the lever 13 rotates counterclockwise about the axis P5 by a spring force (not shown).

When the lever 13 rotates in the counterclockwise direction in this way, the end surface 13b of the lever 13 moves downward, so that the lever 22 whose end surface 22b has been pushed up by the end surface 13b is pushed by the spring 23 to the axis P7. Rotate clockwise around. Then, the locking surface 2 of the lever 22
2a abuts on the locking surface 21b of the lever 21 and the lever 22
Becomes the locked state of FIG. At this time, since the shutter has already been charged, the gear 12g of the cam gear member 12 does not come into contact with the gear portion 18a of the shutter charge gear 18, and the cam surface 12h of the cam gear member 12 does not contact.
Contacts the end surface 18b of the shutter charge gear 18.
As a result, only the shutter charge gear 18 is overcharged (FIG. 21).

When the cam gear member 12 further rotates in the clockwise direction, as shown in FIG. 1, the cam surface 12b and the lever 1 are rotated.
The end face 13a of No. 3 comes into contact, and the position detection switch S3 is turned on. In this way, the position detection switch S3
When it is confirmed in step # 172 that the is turned on,
Next, in step # 173, the brake is applied to the motor M.
After 4 hours, the brake of the motor M is stopped and the power supply to the motor M is stopped in step # 174.
Then, the normal shooting standby state is set (step # 175), and the switching from the second shooting mode to the normal shooting mode is completed. As described above, in the drive system switching mechanism of the present embodiment, since the cam gear member 12 is used, a dedicated motor or the like is not necessary, and therefore, it is possible to prevent the mechanism from becoming complicated and the camera from becoming large.

Next, the release operation in the second photographing mode will be described with reference to the flow chart shown in FIG. First, when the photometric switch S1 is turned on, in step # 181 the subject brightness is measured and the exposure is calculated, and the exposure value is calculated to determine the aperture value and shutter speed. In step # 182, it is determined whether the release switch S2 is on or off. If it is off, the process returns to step # 181 to repeat the photometry.

When it is confirmed that the release switch S2 is turned on, the process proceeds to step # 183, and the release magnet 1 (RFMg), the shutter front curtain holding magnet 1CMg, and the shutter rear curtain holding magnet 2CMg are respectively attached. Energize. At this time, in FIG. 9, the attracting portion 2a of the lever 2 is attracted to the release magnet 1 and the lever 2 rotates counterclockwise about the axis P1. Therefore, the locking portion 2b of the lever 2 and the lever 3
Since the locked state with the locking portion 3a of the
Is rotated counterclockwise about the axis P2 by the urging force of a spring (not shown). Then, the surface 4a of the lever 4
Is pushed by the surface 3b of the lever 3, and the lever 4 rotates clockwise about the axis P3 against the urging force of a spring (not shown). Therefore, the engagement between the engagement portion 8c of the gear 8 and the engagement portion 4b of the lever 4 is released, the gear 8 rotates clockwise, and the aperture of the lens is narrowed down. Also,
When the release magnet 1 (RFMg) is energized, the tip 7a of the lever 7 is attracted to the release magnet 1 (RFMg), so that the levers 6 and 7 do not rotate counterclockwise.

When the gear 8 rotates, the encoder portion 8a also rotates integrally, so that the pulse FP is output. In step # 188, the pulse FP is counted. When it is determined in step # 189 that the number of pulses corresponding to the aperture value of the lens has been counted, the process proceeds to step # 190, and the power supply to the release magnet 1 (RFMg) is stopped. Then, the levers 6 and 7 simultaneously rotate counterclockwise about the axis P4, and the tip claw portion 7b of the lever 7 meshes with the aperture stop plate portion 8b of the gear 8, so that the rotation of the gear 8 stops and the lens The aperture value of is a predetermined value.

On the other hand, when the release magnet 1 (RFMg) is energized in step # 183 and the lever 3 rotates counterclockwise about the axis P2, the surface 3d of the lever 3 pushes the surface 21d of the lever 21. The lever 21 rotates clockwise about the axis P6 against the urging force of a spring (not shown). For this reason, the locking surface 21b is retracted from the locking position with the locking surface 22a of the lever 22 as shown in FIG.

Subsequently, when the motor M is energized in step # 184, the cam gear member 12 rotates clockwise, and the surface 13a of the lever 13 that has been in contact with the cam surface 12e until then.
Comes into contact with the cam surface 12f. When the surface 13a comes into contact with the cam surface 12f, the lever 13 rotates counterclockwise about the axis P5.

When the lever 13 rotates counterclockwise in this way, the lever 22 rotates clockwise about the axis P7 by the urging force of the spring 23 at a speed corresponding to the rotation speed of the lever 13. The lever 24 is pushed upward. At this time, the bent portion 24a of the lever 24 contacts the convex portion 27a of the mirror holder 27, the mirror holder 27 rotates counterclockwise about the axis P8, and the mirror 26 moves to the retracted position. Cam gear member 1
2 rotates clockwise, and the end face 13a of the lever 13
When comes into contact with the cam surface 12b, the mirror 26 is moved to the retracted position and the switch S3 is turned on. When it is confirmed in step # 185 that the switch S3 is turned on in this manner, the process proceeds to step # 186, the brake is applied to the motor M for t4 hours, the rotation of the cam gear member 12 is stopped, and further, in step # 187. Stop energizing M.

Steps # 184 to # 187 and steps # 188 to # 191 are performed in parallel, and steps # 187 and # 19 are performed.
When both 1 are completed, the shutter / diaphragm drive mechanism is in the state of FIG. 6, and the mirror drive mechanism is in the state of FIG. 7. After that, the process proceeds to step # 108 in FIG. 4 and moves to the exposure operation as in the normal shooting mode. Until step # 113, the aperture is opened, the mirror is lowered, and the shutter is released as in the normal shooting operation. To charge. When the switch S3 is turned on in step # 113, the process proceeds to step # 161 of FIG. 14 to return to the initial position of the second shooting mode, and the standby state of the second shooting mode is set in step # 165.

As described above, the mirror 2 is used in the normal photographing mode.
6 is retracted by the urging force of the spring 23.
In the photographing mode, the movement of the lever 13 when the surface 13a moves along the cam surface 12f is used to retract the mirror 26. Therefore, when the motor M is subjected to duty driving in which energization on and off are repeatedly performed at a predetermined time ratio, or speed control driving in which energization is turned on and off while monitoring its rotation so that the motor M is driven at a low speed. Since the cam gear member 12 can be rotated slowly, the operations of the levers 13, 22, 24 and the mirror holder 27 can be slowed down. Therefore, the retracting of the mirror 26 can be performed at a low speed, and the impact when the mirror 26 contacts a stopper (not shown) can be mitigated. In the present embodiment, the retracting operation of the mirror is changed to the normal photographing mode in the second photographing mode. However, in the second photographing mode, the motor is used for the purpose of reducing the collision noise of members other than the mirror. The energization of M may be configured to perform duty driving or speed control driving.

[Brief description of drawings]

FIG. 1 is a first operational state diagram of a shutter / aperture drive mechanism of a camera including a preview mechanism according to an embodiment of the present invention.

FIG. 2 is a first operation state diagram of a mirror driving mechanism of this camera.

FIG. 3 is a block diagram showing a circuit configuration of this camera.

FIG. 4 is a flowchart showing an operation during normal shooting.

FIG. 5 is a second operation state diagram of the shutter / diaphragm drive mechanism.

FIG. 6 is a third operation state diagram of the shutter / diaphragm drive mechanism.

FIG. 7 is a second operation state diagram of the mirror driving mechanism.

FIG. 8 is a flowchart showing a preview operation.

FIG. 9 is a fourth operation state diagram of the shutter / diaphragm drive mechanism.

FIG. 10 is a third operation state diagram of the mirror driving mechanism.

FIG. 11 is a fifth operation state diagram of the shutter diaphragm drive mechanism.

FIG. 12 is a fourth operation state diagram of the mirror driving mechanism.

FIG. 13 is a flowchart showing a release operation while the preview function is working.

FIG. 14 is a flowchart showing a switching operation from the normal shooting mode to the second shooting mode.

FIG. 15 is a flowchart showing an operation of switching from the second shooting mode to the normal shooting mode.

FIG. 16 is a flowchart showing a release operation in a second shooting mode.

FIG. 17 is a first operation state diagram of the shutter charge mechanism.

FIG. 18 is a second operation state diagram of the shutter charge mechanism.

FIG. 19 is a third operation state diagram of the shutter charge mechanism.

FIG. 20 is a fourth operation state diagram of the shutter charge mechanism.

FIG. 21 is a fifth operation state diagram of the shutter charge mechanism.

[Explanation of symbols]

1 Release magnet 2-7 Lever 1-4 Fourth switching means 8-11 Gear 8-10 Second switching means 12 Cam gear member
(Holding means) 12b to 12f Cam surface 12g Teeth 12h Cam surface 13 Lever (Holding means) 13a End surface 13b Surface 18 Charge gear 18a Teeth 18b End surface (cam surface) 21,22 Lever 21 First switching means 22b End surface 23 Spring 24 Lever 25 spring 26 mirror 27 mirror holder 50 CPU (control means) 51 photometric circuit 52 aperture encoder M motor

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshitsugu Yamamoto 2-3-13 Azuchi-cho, Chuo-ku, Osaka-shi, Osaka, Osaka International Building Minolta Camera Co., Ltd. (72) Inventor Takahiro Iimori Azuchi, Chuo-ku, Osaka-shi, Osaka 2-13-3 Machi, Osaka International Building Minolta Camera Co., Ltd. (72) Inventor, Hisanori Ito 2-3-3 Azuchi-cho, Chuo-ku, Osaka City, Osaka Prefecture International Building Minolta Camera Co., Ltd.

Claims (1)

[Claims] 1. A first switching means (21) which can be set to a locking position for holding a mirror (26) in a lowered position and a locking release position for allowing a flip-up operation, and an aperture of a taking lens is opened. Second switching means (8, 9, 10) that can be set to a locking position for holding the position and an unlocking position for allowing the narrowing operation
And a first position for setting both switching means (8, 9, 10, 21) to the locking position, and a second position for setting both switching means (8, 9, 10, 21) to the locking release position The third that can be set to and
In a camera equipped with switching means (1, 2, 3, 4), a preview mechanism is used to narrow down the aperture while holding the mirror (26) in the lowered position, and the mirror (26) is lowered to the lowered position. Holding means to hold (12,13)
The holding means is configured to be positionable between a flip-up prohibited position for prohibiting the flip-up operation of the mirror (26) and a flip-up allowed position for allowing the flip-up operation of the mirror (26). A control means (50) for setting the third switching means (1,2,3,4) to the second position and the holding means (12) to the flip-up prohibited position during the preview operation A preview mechanism featuring.