JPH1096847A - Focusing mode switching device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a focusing mode switching device capable of easily and adequately performing manual focusing even though an automatic focusing mode is set. SOLUTION: This focusing mode switching device 1 is loaded on a single lens reflex camera having an automatic focusing mechanism, and constituted of a motor' 2, a speed change mechanism 3, a clutch mechanism 4, a connecting shaft 5, an output shaft 6, a focusing mode switching mechanism 7, a detecting means 8, and a control means 9. When the automatic focusing mode is set by the mechanism 7, a cam member 73 falls, so that the joint 63 of the shaft 6 protrudes from the front surface of a mount 10, and rotational force can be transmitted to a follower shaft 20 of a photographing lens. In the mode, when the focus ring of the photographing lens is manually rotated and operated, the means 8 detects that, and the means 9 controls the operation of a solenoid 41 so that the mechanism 4 interrupts the transmission of power.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a focusing mode switching device mounted on a camera having an automatic focusing mechanism.

[0002]

2. Description of the Related Art A single-lens reflex camera with an interchangeable lens equipped with an automatic focusing mechanism (AF mechanism) for automatically focusing a taking lens is known. In this type of camera, a focusing mode switching mechanism for switching between an automatic focusing mode and a manual focusing mode is provided in order to provide a function for manually focusing the photographing lens without operating the automatic focusing mechanism. Some have been installed.

This focusing mode switching mechanism has a motor disposed on the camera body side, an output shaft for driving a lens, and a power transmission system for transmitting the torque of the motor to the output shaft. The tip of the output shaft is configured to be able to protrude and retract from the mount on the camera body side in accordance with the switching operation of the focusing mode.

When the automatic focus adjustment mode is set, the tip of the output shaft protrudes from the mount, and engages with a driven shaft for driving a lens of an interchangeable lens mounted on the mount to drive the lens. (Focusing).

In the manual focus adjustment mode, the tip of the output shaft is immersed in the mount, the connection with the driven shaft on the interchangeable lens is released, and the focus ring on the interchangeable lens is manually rotated. , Lens driving can be performed.

In the automatic focus adjustment mode, when the automatic focus mechanism is operated by a half-press operation of the release button (the first-stage release switch is turned on) or the like, distance information (or image shift) to the subject detected by the focus position detecting means is detected. amount)
Based on the above, the lens drive amount is calculated, the motor is rotationally driven by the amount of rotation that can execute it, the rotation is transmitted via the power transmission system, the output shaft and the driven shaft connected thereto, The lens is driven and focus is achieved.

By the way, in the camera provided with the above-described focusing mode switching mechanism, when the automatic focusing mode is set, the photographer performs fine adjustment or the like on the automatic focusing state. For this reason, the focus ring may be manually rotated to change the focus, or it may be desirable to perform manual focusing from the beginning.

However, in this case, an operation for switching the focusing mode to the manual focus adjustment mode must be performed, and there is a problem that the operation is complicated. Due to this operation, a photo opportunity may be missed.

Further, even when the focus ring is set to the automatic focus adjustment mode, the focus ring is manually rotated and operated.
It is virtually possible to drive the lens.

However, in this case, since the output shaft of the camera body and the driven shaft of the interchangeable lens are connected, the rotation of the focus ring causes the rotation of the driven shaft, the output shaft, The power is transmitted to the motor via the power transmission system, and a load is applied to the motor (the rotor of the motor is rotated). Therefore, a load is applied to the rotation of the focus ring, making it difficult to operate the focus ring, and is particularly disadvantageous for fine adjustment. In addition, since an electromotive force is generated in the motor, an adverse effect is caused thereby.

[0011]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a focusing mode switching apparatus which can easily and properly perform manual focusing even when an automatic focusing mode is set. Is to do.

[0012]

This and other objects are achieved by the present invention which is defined below as (1) to (7).

(1) a focusing mode switching mechanism for switching between an automatic focusing mode for automatically focusing a taking lens and a manual focusing mode for manually focusing a taking lens; An output shaft for driving the drive shaft, a drive source for rotating the output shaft, detection means for detecting rotation of the output shaft, and transmission / disconnection of power between the drive source and the output shaft. A clutch mechanism that is set to the automatic focus adjustment mode, and in a state where the drive source is inoperative, when the rotation of the output shaft is detected by the detection unit, the clutch mechanism cuts off transmission of power. Control means for controlling the operation of the clutch mechanism as described above.

(2) The focusing mode switching mechanism includes an operating member and a cam member that is displaced in conjunction with the operation of the operating member, and moves the output shaft in the axial direction with the displacement of the cam member. The focus mode switching device according to the above (1), which is configured to move.

(3) The clutch mechanism constitutes a power transmission path and switches a first gear and a second gear that can mesh with each other between a meshed state and a separated state. Or the focusing mode switching device according to (2).

(4) The clutch mechanism is provided with a solenoid and a pressing member that is connected to a movable portion of the solenoid and that presses the second gear to separate it from the first gear. The focusing mode switching device according to (1).

(5) The focusing mode switching device according to (4), wherein the clutch mechanism includes an urging member for urging the second gear in a direction opposite to a pressing direction of the pressing member.

(6) The control means according to (1) to (5), wherein the control means controls the clutch mechanism, which has interrupted the transmission of the power, to release the interruption due to a predetermined operation. The focus mode switching device according to any one of the above.

(7) A focusing mode switching device for switching between an automatic focusing mode for automatically focusing a taking lens and a manual focusing mode for manually focusing a taking lens. A focusing mode switching device, wherein when the photographing lens is manually driven in a state where the automatic focusing mode is set, the mode is switched to the manual focusing mode.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a focusing mode switching device according to the present invention will be described in detail based on a preferred embodiment shown in the accompanying drawings.

FIG. 1 is a perspective view showing an embodiment of a focusing mode switching device according to the present invention, and FIG. 2 is a partial sectional side view showing a configuration near a cam member in an automatic focusing mode in the focusing mode switching device. FIG. 3 is a partial cross-sectional side view showing the configuration around the cam member in the manual focus adjustment mode in the focusing mode switching device. FIG. 4 is a cross-sectional view taken along line IV-IV in FIG.
5 and 6 are side views showing the configuration of the clutch mechanism in the focusing mode switching device, FIG. 7 is a cross-sectional view taken along the line VII-VII in FIG. 5, and FIG. 8 is a view of the clutch mechanism shown in FIG. It is a front view.

Hereinafter, description will be made with reference to these figures.
For convenience of description, the upper left side in FIG. 1 and the left side in FIGS. 2, 3, 5, and 6 are “proximal ends”, and the lower right side in FIG. 1 and FIGS. 2, 3, 5, and 6 are illustrated. The right side of is called the "tip".

The focusing mode switching device 1 of the present embodiment is mounted on a single-lens reflex camera (camera having a TTL type finder) having an automatic focusing mechanism (AF mechanism), and mainly includes a motor (drive source). 2, a transmission mechanism (power transmission system) 3, a clutch mechanism 4, a connection shaft 5,
An output shaft 6, a focusing mode switching mechanism 7, a detecting means 8,
And control means 9.

The motor 2 is a drive source for rotating the output shaft 6 and thereby moving the focusing lens of the photographing lens in the direction of its optical axis (hereinafter referred to as lens driving). As the motor 2, a motor that can electrically control the amount of rotation, for example, a pulse motor or a DC motor can be used.

The rotation of the rotating shaft 21 of the motor 2 is output after being speed-changed (decelerated) by the speed change mechanism 3 constituted by a gear train. The transmission mechanism 3 includes a small gear 31 fixed to the rotating shaft 21, a spur gear 32 meshed with the small gear 31, a small gear 33 coaxially joined to the spur gear 32, a spur gear 34 meshed with the small gear 31, It comprises a small gear (first gear) 35 coaxially joined to 34 and a spur gear (second gear) 36 meshing with it. The spur gear 36 is fixed to a base end of a movable shaft 52 of the connection shaft 5 described later. These gears 31 to 36 constitute a power transmission path for transmitting the power of the motor 2.

The spur gear 32 is meshed with a spur gear 37 coaxially mounted on the spur gear 32 to rotate an encoder (photo interrupter) 81 of the detecting means 8 described later.

The rotation of the rotary shaft 21 of the motor 2 is transmitted to the output shaft 6 via the clutch mechanism 4 and the connection shaft 5 after being reduced at a predetermined reduction ratio by the transmission mechanism 3.

As shown in FIGS. 5 to 8, the clutch mechanism 4
Has a configuration in which a small gear 35 and a spur gear 36 that can mesh with each other are switched between a meshing state and a separated state.
A pressing member 43 composed of a leaf spring connected to a solenoid 41 and a plunger (movable part) 42 of the solenoid 41
And a biasing member 47 for biasing the spur gear 36 in the proximal direction.

The pressing member 43 is provided at its upper end in FIG.
It has a pair of narrow band-shaped and bent pressing portions 44 formed through the center notch, and the bent portion of the pressing portion 44 abuts on the base end surface of the spur gear 36, and the spur gear 36 has a distal end. Press in the direction.

The lower end of the pressing member 43 in FIG. 5 is rotatably supported by a shaft 45, and a notch 46 is formed in a portion above the supporting portion by a predetermined distance. A reduced diameter portion 421 formed at the tip of the plunger 42 is inserted into and engaged with the notch 46.

At the base end of the connection shaft 5, a movable shaft 52 that is extendable and retractable with respect to the shaft main body 51 is inserted. As shown in FIG. 7, the cross section of the movable shaft 52 has a shape in which two opposing circular portions are lost in an arc shape. Although it moves (expands and contracts), it does not slip in the rotational direction, and is configured to be able to transmit rotational force to each other reliably.

The biasing member 47 is constituted by a coil spring.
Disc-shaped flange 53 fixed to shaft body 51
And a spur gear 36 in a compressed state. The urging member 47 urges the spur gear 36 in the base direction, that is, in the direction opposite to the pressing direction of the pressing member 43.

Next, the operation of the clutch mechanism 4 will be described. As shown in FIG. 5, when the solenoid 41 is energized (or is not energized), the plunger 42 is extended, and the pressing member 44 is in a substantially vertical state in FIG.
The pressing force on the spur gear 36 is weak. Therefore, the spur gear 36
Is moved in the proximal direction by the urging force of the urging member 47,
It meshes with the small gear 35. Thereby, the clutch mechanism 4
Is in a state where the power generated by the motor 2 can be transmitted (hereinafter, referred to as a “connection state”).

Also, as shown in FIG.
In the non-energized state (or energized state), the plunger 42 contracts, and the pressing member 44 presses the spur gear 36 toward the distal end against the urging force of the urging member 47 to move. Therefore, the spur gear 36 is separated from the small gear 35. As a result, the clutch mechanism 4 interrupts the transmission of power between the motor 2 and the output shaft 6 (hereinafter, referred to as an “interrupted state”).
Becomes

As shown in FIGS. 2 and 3, a hollow portion 54 is formed at the distal end of the connection shaft 5, and the base end portion 61 of the output shaft 6 is connected to the connection shaft 5 in the hollow portion 54. On the other hand, it is stretchably inserted and connected.

As shown in FIG. 4, the base 61 of the output shaft 6
Has a shape in which two opposing circular portions are lost in an arc shape, and the hollow portion 54 also has a corresponding cross-sectional shape. Thus, the output shaft 6 is configured to move (expand and contract) in the axial direction with respect to the connection shaft 5, but does not slip in the rotational direction, and can surely transmit the rotational force to each other.

An enlarged diameter portion 55 is formed at the tip of the connection shaft 5, and a disc-shaped flange 6 is formed on the output shaft 6.
2 is fixed. Then, the flange 62 and the enlarged diameter portion 5
5, a biasing member 76 composed of a coil spring is installed in a compressed state. The output shaft 6 is urged toward the distal end by the urging member 76.

At the distal end of the output shaft 6, there is provided a joint 63 which can be connected (connected) to a proximal end of a driven shaft 20 of a taking lens driving mechanism described later. This joint 63
It is composed of a protrusion that protrudes in a single character.

Such a focusing mode switching device 1 controls an automatic focusing mode (autofocus mode) for automatically performing focusing (lens driving) of a photographing lens and a manual focusing (lens driving) of a photographing lens. And a focusing mode switching mechanism 7 for switching the mode to a manual focus adjustment mode (manual focus mode).

The focusing mode switching mechanism 7 mainly includes an operating member (focusing mode switching switch) 71 and the operating member 7.
1, a movable block 72 that moves vertically in FIG. 1, a cam member 73 formed on the movable block 72, a driven member 74 that engages with the cam member 73, and a driven member 74. And a positioning member 75 for holding the operation member 71 and the movable block 72 at predetermined positions.

The operating member 71 is exposed to the outside of the camera body, and has irregularities 711 for preventing slippage during operation. The operating member 71 is connected to the movable block 72 by a connecting rod 712.

The positioning member 75 is formed of a plate-like member made of a soft resin or the like, and is fixed to the camera body. A groove 751 extending in the up-down direction in FIG. 1 is formed in the positioning member 75, and in the middle of the groove 751,
Circular holes 752 and 753 are formed at a predetermined distance from each other.

With the movement operation of the operation member 71, the groove 751
When the connecting rod 712 slides inside and fits in the circular holes 752 and 753, the operation member 71 and the movable block 72 are positioned. That is, when the connecting rod 712 is fitted in the circular hole 752, the automatic focus adjustment mode described later is set, and when the connecting rod 712 is fitted in the circular hole 753, the manual focusing mode described later is set.

The cam member 73 formed at one end of the movable block 72 has an inclined surface 732 inclined at a predetermined angle with respect to the moving direction of the movable block 72, and is connected to the lower end of the inclined surface 732 so as to be movable in the moving direction of the movable block 72. It has a cam surface 731 consisting of a parallel surface 733.

The driven member 74 is formed of a plate having a predetermined shape, and is supported so as to be movable in the axial direction of the output shaft 6. The driven member 74 is in contact with the distal end surface of the flange 62 of the output shaft 6 by the urging force of the urging member 76. The driven member 74 has a hole 741 through which the output shaft 6 is inserted. The lower end 742 of the driven member 74 is in contact with the cam surface 731.

The movable block 72 has a plurality of electrical contacts 7
8 is fixed. This brush 7
7 contacts a code plate (not shown) fixed to the camera body, and the position of the electric contact 78 with respect to the code plate, that is, the position of the movable block 72, that is, the conduction pattern corresponding to this position. Whether the focusing mode is the automatic focusing mode or the manual focusing mode can be electrically detected. Note that the detected focusing mode information is input to the control unit 9 and used for display on a display unit (not shown) such as an LED, an LCD, or the like.

A ring-shaped mount 10 is fixed to the front of the camera body. In this mount 10,
A lens-side mount provided at the base end of a lens barrel of a photographic lens (interchangeable lens) not shown is detachably mounted.
A plurality of terminals 11 electrically connected to terminals (not shown) of the lens-side mount to be mounted are provided on the surface of the mount 10.
Is provided. Further, the mount 10 is formed with a hole 12 through which a shaft 14 for fixing a photographing lens is inserted and a hole 13 through which the output shaft 6 is inserted.

The photographing lens has a built-in photographing lens driving mechanism for driving the focusing lens by rotation of the driven shaft 20. The base end of the driven shaft 20 is located near the lens-side mount. When the photographing lens is mounted on the mount 10 on the camera body side and the automatic focus adjustment mode is set,
A joint 63 of the output shaft 6 is fitted with a base end of the driven shaft 20;
In this way, the rotational force of the output shaft 6 can be transmitted to the driven shaft 20.

As shown in FIG. 1, the base end of the shaft 14 is fixed to a lens attaching / detaching button 16 via a support member 15. The lens attaching / detaching button 16 is urged in the distal direction by a spring 17, and in this state, the shaft 14
Protrudes from the surface of the mount 10 by a predetermined length, and engages with the lens-side mount to prevent rotation of the taking lens with respect to the mount 10, that is, detachment from the mount 10.

On the other hand, when the lens attachment / detachment button 16 is pushed in the proximal direction against the urging force of the spring 17, the shaft 14 moves in the same direction, and the tip of the shaft 14 enters the hole 12. . Thus, the rotation of the photographing lens with respect to the mount 10, that is, the mounting of the photographing lens
It can be removed from the device.

One end of a connecting member 18 formed by bending a narrow plate piece as desired is fixed to the supporting member 15. The other end of the connecting member 18 is connected to one end of the driven member 74. It is fixed to. Accordingly, when the detachable button 16 is pressed, the movement of the detachable button 16 in the proximal direction is transmitted to the driven member 74 via the support member 15 and the connecting member 18, and the position of the cam member 73 and the driven member 74 is maintained. 3, the driven member 74 is in the position shown in FIG. 3, the joint 63 of the output shaft 6 is immersed in the hole 13, and the rotation of the taking lens with respect to the mount 10, that is, the removal of the taking lens from the mount 10 becomes possible.

The detecting means 8 is originally provided for detecting the rotation of the motor 2.
Can optically detect the rotation of the output shaft 6, that is, the manual drive of the lens.

The detecting means 8 includes an encoder (photo interrupter) 81 in which slits 82 are formed at equal intervals on the outer periphery of a disk rotating coaxially with the spur gear 37, a light emitting element and light from the light emitting element. A light receiving element that receives light and converts the light into an electric signal is configured by a detection unit 83 that is opposed to the light receiving element via a space through which the outer peripheral portion of the encoder 81 passes.

When the clutch mechanism 4 is engaged and the focus ring of the taking lens is manually rotated in any direction to drive the lens, the driven shaft 20 is rotated accordingly, and this rotational force is applied to the driven shaft. 20 and transmitted to the encoder 81 via the connection shaft 5, the spur gear 36, the small gear 35, the spur gear 34, the small gear 33, the spur gear 32 and the spur gear 37,
The encoder 81 is rotated. Thereby, the detection unit 83
Receive the light from the light emitting element intermittently and output a pulse signal. This pulse signal is supplied to the control means 9
Is input to

In the manual focus adjustment mode, the transmission of the torque between the output shaft 6 and the driven shaft 20 is interrupted. Therefore, even if the lens is manually driven, the encoder 81 does not rotate. No pulse signal is generated.

The control means 9 is constituted by, for example, a microcomputer (CPU). The control means 9 mainly controls the drive of the motor 2 for automatic focusing and the operation control of the clutch mechanism 4 based on the detection by the detection means 8. And do.

First, the drive control of the motor 2 will be described. Although not shown, the camera body has a built-in automatic focusing mechanism that is operated by a half-press operation of a release button (a first-stage release switch is turned on) or the like. More specifically, a focus detection optical unit 19 is installed at a position optically equivalent to the film surface below the mirror box of the camera body. As the focus detection optical unit 19, for example, the one described in JP-A-2-210335 can be used, and it has a focus position detection unit using a phase difference detection method. This focus position detecting means includes a pupil division optical system and a solid-state image pickup device (CCD), and a shift amount (image shift amount) of an image forming position with respect to a position optically equivalent to a film surface of a subject image passing through a photographing lens. Is detected optically.

The detected image shift amount is input as focal position information to an arithmetic unit built in the control means 9 and, based on this information, the driving amount of the photographing lens up to the in-focus position, that is, the rotation amount of the motor 2 Is calculated. And control means 9
Controls the driving of the motor 2 so as to execute the calculated rotation amount of the motor 2.

In this embodiment, an example is described in which the phase difference detection method among the passive methods is adopted as the automatic focusing mechanism. However, it is needless to say that the type and method of the automatic focusing mechanism are not limited to this. No.

Next, the operation control of the clutch mechanism 4 will be described with reference to the flowchart shown in FIG.

As a prerequisite, the focusing mode is configured to select one of the automatic focusing mode and the manual focusing mode. In the automatic focusing mode, if the photometry switch is kept on, the object It is assumed that the lens is not driven even if the distance changes.

After turning on the main switch (power switch), the rotation of the encoder 81 is detected (step 10).
1) When it is determined that the rotation of the encoder 81 is present,
That is, when a pulse signal is input from the detection unit 83 to the control unit 9, the operation of the solenoid 41 is controlled as described above to put the clutch mechanism 4 into a disconnected state (step 109), and the process returns to step 101 again. .

If the result of determination in step 101 is that there is no rotation of the encoder 81, it is determined whether or not the photometric switch (the first stage of the release switch) is on (step 102). As a result, when the photometry switch is off, the process returns to step 101 again, and when the photometry switch is on, it is determined whether the focusing mode is the automatic focusing mode or the manual focusing mode (step 103).

If the focus mode is the manual focus adjustment mode, it is determined whether or not the release switch (the second stage of the release switch) is on (step 110). If the release switch is off, the operation is restarted. Returning to step 110, if the release switch is on, a release operation is performed (step 111), and the process returns to step 101 again.

If the result of determination in step 103 is that the focusing mode is the automatic focus adjustment mode, first, as described above, the operation of the solenoid 41 is controlled to bring the clutch mechanism 4 into the connected state (step 104). And then motor 2
Is being driven, that is, whether or not automatic focusing is being performed (step 105).

As a result of the determination in step 105, the motor 2
If the release switch is on, it is determined whether the release switch is on (step 106). If the release switch is off, it is determined whether the photometry switch is on (step 107). Is on,
After performing the release operation (step 114), the process proceeds to step 107.

If the result of determination in step 107 is that the photometry switch is on, the process returns to step 105 again. If the photometry switch is off, the clutch mechanism 4 is connected (step 108), and step 101 is performed again. Return to

As a result of the determination in step 105, the motor 2
Is not driving (unfocused or focused), the rotation of the encoder 81 is detected (step 11).
2) If it is determined that the rotation of the encoder 81 is present, the clutch mechanism 4 is turned off (step 11).
3) Then, proceed to step 107. Step 11
If it is determined in step 2 that there is no rotation of the encoder 81, the process proceeds to step 106.

Next, the operation of the focusing mode switching device 1 will be described. The operating member 71 is operated to select the automatic focusing mode or the manual focusing mode. The operation in each mode will be described.

[Automatic focus adjustment mode] As shown in FIGS. 1 and 2, the operation member 71 is positioned below in FIG.
When the connecting rod 712 is fitted into the circular hole 752, the automatic focusing mode is set. In the automatic focus adjustment mode, the lowering of the movable block 72 in accordance with the operation of the operating member 71 causes the cam member 73 to move down in the same manner. As a result, as shown in FIG. 731 is in contact with the upper part of the inclined surface 732. At this time, the output shaft 6 is urged in the distal direction by the urging member 76, and the flange 62 is in contact with the driven member 74 and is stationary. In this state, the joint 63 at the tip of the output shaft 6
Protrudes from the front surface of the mount 10 and fits with the base end of the driven shaft 20 of the photographing lens mounted on the mount 10. Thus, the output shaft 6 and the driven shaft 20 can mutually transmit a rotational force.

In this mode, for example, when a first-stage release switch (light measurement switch / distance measurement switch), not shown, composed of a two-stage switch is turned on, the focus detection optical unit 19 is operated, and the image shift amount is set. Is detected and input to the calculation unit of the control means 9 as focal position information. Based on this information, the drive amount of the lens up to the focus position, that is, the rotation amount of the motor 2 is calculated. And the control means 9
The drive of the motor 2 is controlled to execute the calculated rotation amount of the motor 2.

The rotation of the motor 2 is transmitted to the transmission mechanism 3, the clutch mechanism 4, the connection shaft 5, and the output shaft 6 as described above, and rotates the driven shaft 20 by a predetermined amount. As a result, the lens is driven and focus is achieved.

When such automatic focusing is not performed, that is, when the motor 2 is not operated and the focus ring of the taking lens is manually rotated to drive the lens, it is detected. Detected by means 8. That is, the rotation of the focus ring causes the driven shaft 20 to rotate in a direction corresponding to the rotation direction,
This rotation is transmitted to the encoder 81 via the output shaft 6, the connection shaft 5, the spur gear 36, the small gear 35, the spur gear 34, the small gear 33, the spur gear 32, and the spur gear 37, and the encoder 81 is rotated and detected. The pulse signal is output from the unit 83.

Upon detecting this pulse signal, the control means 9 immediately controls the operation of the solenoid 41 so as to bring the clutch mechanism 4 into the disconnected state. In other words, control is performed so as to switch to the manual focus adjustment mode (the state is different from the manual focus adjustment mode selected by operating the operation member 71, but has a similar function). When the clutch mechanism 4 is in the disengaged state in this manner, the torque of the output shaft 6 and the connection shaft 5 is not transmitted to the motor 2 via the transmission mechanism 3, so that a load for rotating the rotor of the motor 2 is generated. And the lens can be driven manually.

When the automatic focusing is required again, for example, after the photographing is completed (in a standby state for the next photographing), once the release button is released, the release button is half-pressed again (photometry switch). When the distance measurement switch is turned on), the control means 9 controls the operation of the solenoid 41 to return the clutch mechanism 4 to the connected state due to these operations.

In the example shown in FIG. 9, after the clutch mechanism 4 is disconnected, the clutch mechanism 4 is returned to the connected state by turning on the photometric switch. However, as another example, the photometric switch is switched after the clutch mechanism 4 is disconnected. The clutch mechanism may be connected only after the ON and OFF operations of the clutch mechanism are performed.

[Manual Focus Adjustment Mode] When the operation member 71 is positioned above in FIG. 1 and the connecting rod 712 is fitted into the circular hole 753, the manual focus adjustment mode is set. In the manual focus adjustment mode, the cam member 73 is similarly raised by the movement of the movable block 72 accompanying the operation of the operation member 71, and as a result, as shown in FIG. The sliding member 731 slides along the inclined surface 732 and comes into contact with a position beyond the inclined surface 732, that is, a surface 733 parallel to the moving direction of the movable block 72.

As a result, the driven member 74 moves in the proximal direction, the flange 62 is pressed in the same direction against the urging force of the urging member 76, and the output shaft 6 moves a predetermined distance in the same direction. Therefore, the joint 63 at the distal end of the output shaft 6 is immersed in the hole 13 of the mount 10 and the engagement with the base end of the driven shaft 20 is released. Thereby, the output shaft 6 and the driven shaft 20
The transmission of the rotational force is interrupted, and the lens can be manually driven without generating a load for rotating the rotor of the motor 2.

FIG. 10 is a flowchart showing an operation control program of the clutch mechanism in another embodiment of the focusing mode switching apparatus of the present invention. The structure of each part of the device in this embodiment is the same as that of the above-described embodiment, so that the description thereof is omitted, and the operation control of the clutch mechanism 4 will be described below.

As a prerequisite, the focusing mode is configured to select one of the automatic focusing mode and the manual focusing mode. In the automatic focusing mode, if the photometry switch is kept on, the subject It is assumed that the lens is not driven even if the distance changes.

After turning on the main switch (power switch), the rotation of the encoder 81 is detected (step 20).
1) When it is determined that the rotation of the encoder 81 is present,
That is, when a pulse signal is input from the detection unit 83 to the control unit 9, the operation of the solenoid 41 is controlled as described above, the clutch mechanism 4 is turned off (step 209), and the process returns to step 201 again. .

If the result of determination in step 201 is that there is no rotation of the encoder 81, it is determined whether or not the photometric switch (the first stage of the release switch) is on (step 202). As a result, when the photometry switch is off, the process returns to step 201 again, and when the photometry switch is on, it is determined whether the focusing mode is the automatic focusing mode or the manual focusing mode (step 203).

If the focus mode is the manual focus adjustment mode, it is determined whether or not the release switch (second stage of the release switch) is on (step 210). If the release switch is off, the operation is repeated. Returning to step 210, if the release switch is on, a release operation is performed (step 211), and the process returns to step 201 again.

If the result of determination in step 203 is that the focusing mode is the automatic focus adjustment mode, the operation of the solenoid 41 is controlled as described above to bring the clutch mechanism 4 into the connected state (step 204). And then motor 2
It is determined whether or not is being driven, that is, whether or not automatic focusing is being performed (step 205).

As a result of the determination in step 205, the motor 2
If the release switch is on, it is determined whether the release switch is on (step 206). If the release switch is off, it is determined whether the photometry switch is on (step 207). Is on,
After performing the release operation (step 208), the process proceeds to step 207.

If the result of determination in step 207 is that the photometry switch is on, the process returns to step 205 again, and if the photometry switch is off, the process returns to step 201 again.

As a result of the determination in step 205, the motor 2
Is not driving (unfocused or focused), the rotation of the encoder 81 is detected (step 21).
2) If it is determined that there is no rotation of the encoder 81, the process proceeds to step 206.

As a result of step 212, if it is determined that the encoder 81 is rotating, the clutch mechanism 4 is turned off (step 213), and then it is determined whether the photometric switch is on (step 214). If the photometry switch is on, it is further determined whether or not the release switch is on (step 215).

If the result of determination in step 214 is that the photometric switch is off, it is determined again whether the photometric switch is on or off (step 218). If the photometric switch is on, then the release switch is turned on or off. The process proceeds to a determination operation (step 215).

If it is determined in step 215 that the release switch is on, a release operation is performed (step 2).
16) After that, the clutch mechanism 4 is returned to the connected state,
It returns to step 201 again.

In step 215, if the release switch is off, it is determined again whether the photometry switch is on or off (step 219). If the photometry switch is on, the process returns to step 215 again, and the photometry switch is turned off. If so, the process proceeds to step 217, where the clutch mechanism 4
Is returned to the connected state.

In the focusing mode switching apparatus having such a configuration, as shown in step 212 and subsequent steps, the encoder 81
After the clutch mechanism 4 is shut off by detecting the rotation of the lens, the clutch mechanism 4 is returned to the connected state by turning on and off the photometric switch. Therefore, even if the photometric operation is interrupted without releasing after shifting to the manual focus adjustment mode There is an advantage that the clutch mechanism can be returned to the connected state.

Although the present invention has been described based on the illustrated embodiment, the present invention is not limited to this.
Each mechanism, means, and the like constituting the present invention can be replaced with an arbitrary configuration that can exhibit the same function.

[0094]

As described above, according to the focusing mode switching device of the present invention, even when the automatic focusing mode is set, the clutch mechanism is connected between the driving source and the output shaft. By acting to shut off the transmission of power,
Manual focusing can be performed easily, that is, without generating a load on the driving source. Therefore, manual focusing, especially fine adjustment, can be performed accurately.

Further, since no electromotive force is generated in the drive source when manual focusing is performed in the automatic focus adjustment mode, there is no need to devise the electromotive force.
The circuit configuration can be simplified, and the consumption of the driving source can be suppressed.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of a focusing mode switching device of the present invention.

FIG. 2 is a partial cross-sectional side view showing a configuration near a cam member in an automatic focusing mode in the focusing mode switching device.

FIG. 3 is a partial sectional side view showing a configuration near a cam member in a manual focus adjustment mode in the focusing mode switching device.

FIG. 4 is a sectional view taken along line IV-IV in FIG.

FIG. 5 is a side view showing a configuration of a clutch mechanism in the focusing mode switching device.

FIG. 6 is a side view showing a configuration of a clutch mechanism in the focusing mode switching device.

FIG. 7 is a sectional view taken along line VII-VII in FIG. 5;

FIG. 8 is a front view of the clutch mechanism shown in FIG.

FIG. 9 is a flowchart showing an operation control program of a clutch mechanism.

FIG. 10 is a flowchart showing an operation control program of a clutch mechanism in another embodiment of the focusing mode switching device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Focusing mode switching device 2 Motor 21 Rotary shaft 3 Transmission mechanism 31, 32 Spur gear 33 Small gear 34 Spur gear 35 Small gear 36 Spur gear 37 Spur gear 4 Clutch mechanism 41 Solenoid 42 Plunger 421 Reduced diameter part 43 Pressing member 44 Pressing part 45 Shaft 46 Notch 47 Biasing member 5 Connection shaft 51 Shaft main body 52 Movable shaft 53 Flange 54 Hollow part 55 Large diameter part 6 Output shaft 61 Base end 62 Flange 63 Joint 7 Focusing mode switching mechanism 71 Operating member 711 Unevenness 72 Movable block 73 Cam member 731 Cam surface 732 Inclined surface 733 Surface 74 Follower member 741 Hole 742 Lower end 75 Positioning member 751 Groove 752, 753 Circular hole 76 Energizing member 77 Brush 78 Electric contact 8 Detecting means 81 Encoder 82 Detecting section 9 Control means 10 Mount 11 Terminal 12, 13 hole 14 Shaft 15 Support member 16 Lens attach / detach button 17 Spring 18 Connecting member 19 Focus detection optical unit 20 Follower shaft 101-114 Step 201-219 Step

Claims (7)

[Claims] A focusing mode switching mechanism for switching between an automatic focusing mode for automatically focusing a photographic lens and a manual focusing mode for manually focusing a photographic lens; An output shaft for driving; a drive source for rotationally driving the output shaft; a detection unit for detecting rotation of the output shaft; and a transmission / disconnection of power between the drive source and the output shaft. A clutch mechanism, when the automatic focus adjustment mode is set and the drive source is inoperative, and when the rotation of the output shaft is detected by the detection unit, the clutch mechanism cuts off transmission of power. Control means for controlling the operation of the clutch mechanism. 2. A focusing mode switching mechanism comprising: an operation member; and a cam member that is displaced in conjunction with operation of the operation member, and moves the output shaft in the axial direction with the displacement of the cam member. The focusing mode switching device according to claim 1, wherein the focusing mode switching device is configured to perform the focusing operation. 3. The clutch mechanism according to claim 1, wherein the clutch mechanism constitutes a power transmission path and switches a first gear and a second gear that can mesh with each other between a meshed state and a separated state. 3. The focusing mode switching device according to item 1. 4. The clutch mechanism according to claim 3, wherein the clutch mechanism includes a solenoid, and a pressing member connected to a movable portion of the solenoid and pressing the second gear to separate the second gear from the first gear. The focus mode switching device according to any one of the preceding claims. 5. The focusing mode switching device according to claim 4, wherein the clutch mechanism includes an urging member for urging the second gear in a direction opposite to a pressing direction of the pressing member. 6. A control device according to claim 1, wherein said control means controls the clutch mechanism, which has interrupted the transmission of said power, to release said interruption, due to a predetermined operation.
The focusing mode switching device according to any one of the above. 7. A focusing mode switching device for switching between an automatic focusing mode for automatically focusing a photographic lens and a manual focusing mode for manually focusing a photographic lens, A focus mode switching device configured to switch to the manual focus adjustment mode when the photographing lens is manually driven in a state where the focus adjustment mode is set.