JPH1082944A - Lens drive - Google Patents

Abstract

(57) [Summary] Although autofocus is possible, when an operation ring is operated, in a mode in which lens driving is performed according to the operation amount of the operation ring (manual priority autofocus mode), Provided is a lens driving device capable of smoothly switching between lens driving by autofocus and lens driving according to an operation amount of an operation ring. A lens driving device that drives a lens according to an operation amount of an operation ring when an operation ring is operated in a mode in which autofocus is possible, and detects an operation amount of the operation ring. Rotary encoder 80
When the operation ring 40 is operated in the mode while the lens is driven to perform the autofocus in the mode, the rotary encoder 8
And a motor 30 for driving the lens according to the operation amount of the operation ring 40 detected by the control unit 0.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for operating an operation ring in a mode in which auto focus is possible.
The present invention relates to a lens driving device that drives a lens according to an operation amount of the operation ring.

[0002]

2. Description of the Related Art Conventionally, a camera capable of performing manual priority autofocus has been known.

[0003] The manual priority autofocus is a method of driving a lens according to the operation amount of the operation ring when the operation ring is operated in a mode in which autofocus is possible. That is, when the manual priority autofocus mode is set for the camera, not only can autofocus be performed, but also if necessary, manual focus adjustment can be further performed.

[0004]

However, in the conventional camera, when switching from auto focus to manual focus adjustment in the manual priority auto focus mode, a dedicated actuator is required.

[0005] Switching by such an actuator not only prolongs the switching time but also complicates the mechanism of the lens barrel by the provision of the actuator.

In view of such a problem, an object of the present invention is to enable auto-focusing. However, when the operation ring is operated, a mode in which the lens is driven in accordance with the operation amount of the operation ring ( In manual priority auto focus mode), lens drive by auto focus,
An object of the present invention is to provide a lens driving device that can smoothly switch between lens driving according to the operation amount of an operation ring.

[0007]

According to one aspect of the present invention for achieving the above object, when the operation ring is operated in a mode in which autofocus is possible, the operation ring is operated in accordance with the operation amount of the operation ring. A lens driving device for driving a lens by operating the operation ring in the mode while detecting the operation amount of the operation ring, and driving the lens to perform autofocus in the mode. A driving force generating means for driving the lens in accordance with the operation amount detected by the detecting means.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an example of a lens barrel to which a lens driving device according to the present invention is applied.

When the lens barrel 100 shown in FIG. 1 is mounted on a camera body 200 (not shown),
When the auto focus only mode (AF mode) in which only auto focus can be performed, the manual focus only mode (MF mode) in which only manual focus can be performed, and when the operation ring 40 is operated although auto focus is possible, One of three modes of a manual priority autofocus mode (M / A mode) in which the lens is driven according to the operation amount of the operation ring 40 is set. The operation ring 40 is a focus ring that is rotated when the user performs focus adjustment.

More specifically, the lens barrel 100 includes a fixed barrel 10 fixed to the camera body 200 and a cam barrel 20 rotatably fitted to the outer periphery of the small diameter portion 10a of the fixed barrel 10.
A motor 30 similarly fixed to the outer periphery of the small-diameter portion 10a using screws or the like; the above-described operating ring 40 rotatably fitted to the outer periphery of the large-diameter portion 10b of the fixed cylinder 10; A switching member 50 slidably mounted on the outer periphery of the cam, a clutch mechanism 60 for switching the connection destination of the cam barrel 20 according to the set position of the switching member 50, and three lens groups (a first lens group 70, a second lens And a third lens group 72). The fixed cylinder 10 is provided with a mount 11. The mount 11 allows the fixed barrel 10 to be detachably attached to the camera body 200. A gear 32 is engaged with a gear 31 provided on a motor shaft of the motor 30. Gear 32
Is provided with a coupler 33. First lens group 7
The lens group 0, the second lens group 71, and the third lens group 72 are sequentially held by lens group holding cylinders 73, 74, and 75. The lens group holding tubes 73 and 75 are fixed to the inner periphery of the fixed tube 10. The lens group holding tube 74 is slidably fitted on the inner periphery of the fixed tube 10. A cam pin 74a is provided on the outer periphery of the lens group holding cylinder 74. Cam pin 74a
Are a straight groove 10c formed in the fixed cylinder 10 and the cam cylinder 2
0 are inserted into both of the cam grooves 20a.
FIG. 2 is a development view of this part.

As shown in FIG. 2, the rectilinear groove 10c is formed parallel to the optical axis. The cam groove 20a defines a movement locus of the lens group holding cylinder 74 (second lens group 71) during focusing, and is formed so as to cross the rectilinear groove 10c. That is, when the cam barrel 20 rotates around the optical axis, the cam pin 74a of the lens group holding barrel 74
The second lens group 71 moves along the rectilinear groove 10c, and moves in the optical axis direction without rotating around the optical axis. Thus, focusing of the lens barrel 100 is performed. The first lens group 70 and the third lens group 7
For 2, since each lens group holding cylinder is fixed to the inner periphery of the fixed cylinder 20, these positions do not change.

Returning to FIG. 1, the clutch mechanism 60 will be described.

The clutch mechanism 60 includes a gear 62 having a coupler 61, a clutch ring 64 having a pin 63 penetrating through the flange portion 20 b of the cam cylinder 20, a clutch ring 64 fixed to the switching member 50, and a gear 62 and a clutch ring 6.
4 and an engagement member 65 engaged with both of them. A spring 66 having one end fixed to the fixed cylinder 10 is attached to the engagement member 65. The engagement member 65 is always drawn to the right side in the drawing by the force of the spring 66. The fixed cylinder 10 has a stopper 10d
Is provided, so that the engagement member 65 does not move earlier than this. The operation ring 40 is formed with an inward projection 40a. The projection 40 a has a portion cut out in front of the pin 63.

The gear 62 meshes with a gear portion 20c formed on the outer periphery of the cam barrel 20.
Are fitted on the outer periphery of the cam cylinder 20. These members can slide on the cam barrel 20 in parallel with the optical axis. Therefore, when the switching member 50 is slid, the gear 62 and the clutch ring 64 move together with the engagement member 65 in the same direction as the switching member 50.

On the upper surface of the switching member 50, a small switch 51 is provided. AF mode, MF mode,
Switching of the M / A mode is performed through this switch. The switch 51 can be moved with respect to the switching member 50 only between two positions predetermined on the switching member 50. For example, when the switching member 50 is at the position shown in FIG. 1 by the action of the spring 66 and the stopper 10d, the switch 51 is moved only between the two positions of the AF mode setting position and the M / A mode setting position. be able to. On the other hand, when it is desired to set the switch 51 to the MF mode setting position, the switching member 50 itself may be moved to the left while the switch 51 is in the state shown in FIG.

When the switching member 50 is located at the position shown in FIG. 1 (that is, when the switch 51
/ A mode), coupler 3
3 and the coupler 61 are connected, and the pin 6 of the gear 64 is
The tip portion 3 is located just before the notch 40b of the projection 40a. On the other hand, when the switching member 50 moves to the left from the position in FIG. 1 (that is, when the switch 51 is set to the MF mode), the coupler 3
3 and the coupler 61 are disengaged and the pin 6
3 is disposed in the notch 40b of the projection 40a.

Next, a detection means (in this embodiment, the rotary encoder 80) for detecting the operation amount of the operation ring 40 will be described.

The rotary encoder 80 includes a fixed cylinder 10
3 and the operation ring 40. Specifically, FIG.
It is configured as shown in FIG.

That is, the rotary encoder 80
The brush 81 attached to the operation ring 40 and the fixed cylinder 10
And an annular substrate 82 attached to the base plate. On the annular substrate 82, three types of patterns are printed in the circumferential direction as conductor portions. The ground pattern is located on the outermost side, and the A-phase pulse pattern is located inside the ground pattern, and the B-phase pulse pattern is located inside the ground pattern. In each of the A-phase pulse pattern and the B-phase pulse pattern, conducting portions and non-conducting portions are formed alternately. However, as shown in FIG. The tip of the brush 81 is divided into three, and when the operation ring 40 is rotated, these three tips slide on the corresponding patterns. Further, each metal pattern of the brush 81 and the annular substrate 82 is electrically connected to the lens-side CPU 90 as shown in FIG. The lens CPU 90 is built in the lens barrel 100, but is not shown in FIG. 1 because the drawing is complicated.

When the operation ring 40 is rotated, the rotary encoder 80 outputs a signal as shown in FIG.
One pulse signal or two pulse signals as shown in FIG. Specifically, FIG.
The two pulse signals shown in FIG. 5A are output when the brush 81 moves clockwise in FIG.
Are output when the brush 81 moves counterclockwise in FIG. Lens side CP
U90 is the 2 output from the rotary encoder 80.
Of the phases of two pulse signals (that is, an A-phase pulse signal generated by sliding the brush 81 with the A-phase pulse pattern and a B-phase pulse signal generated by sliding the brush 81 with the B-phase pulse pattern). The rotation direction of the operation ring 40 is detected from the deviation, and the rotation speed of the operation ring 40 is calculated from the pulse period.

In addition to the rotary encoder 80, the switch 51 and the motor 30 described above are also connected to the lens side CPU 90. Further, the camera body 200 has a built-in body-side CPU 91, and when the lens barrel 100 is mounted on the camera body 200, the body-side CPU 91 is also electrically connected to the lens-side CPU 90. . The body-side CPU 91 includes switches 93 and 94 interlocked with a release button (not shown).
And the distance measuring circuit 92 are connected. The switch 93 is turned on when the release button is half-pressed, and the switch 9 is turned on.
4 turns ON when the release button is fully pressed.

FIG. 6 shows a schematic configuration of a portion related to focus detection in the optical system built in the camera.

Each of the first lens group 70, the second lens group 71, and the third lens group 72 is as described above. The photographing light obtained through these lens groups is incident on the main mirror 95. . Part of the light that has entered the main mirror 95 passes through the main mirror 95 and is further split by the sub-mirror 97. One of the split lights is directed to the film surface 96, and the other split light is
The light enters the sensor module 98. The sensor module 98 has a built-in distance measuring element that is a part of the above-described distance measuring circuit 92, and light incident on the sensor module 98 is received by the distance measuring element.

Next, the operation of each part of the camera of the present embodiment constituted by the lens barrel 100 and the camera body 200 will be described. When a main switch (not shown) is turned ON in the camera, the flow shown in FIG. 7 is performed.

In step S701, it is detected whether or not the release button has been half-pressed (whether or not the switch 93 has been turned on). The detection is performed by the body-side CPU 91 based on the ON / OFF signal of the switch 93. If the release button has been half-pressed, the flow proceeds to S702.

In S702, it is determined whether the currently set focus mode is the MF mode. If the MF mode has not been set, the process proceeds to S703.

In step S703, it is determined whether the currently set focus mode is the M / A mode. If the M / A mode has been set, the process proceeds to S704.

From the switch 51 of the lens barrel 100,
A signal corresponding to the set position is output to the lens side CPU 90, and the currently set focus mode is determined.
The lens-side CPU 90 performs the processing based on this signal. This determination result is sent to the body-side CPU 91. MF
The setting of each mode of the mode, the AF mode, and the M / A mode is performed by the emphasis operation of the lens CPU 90 and the camera CPU 91 when the switch 51 is switched. That is, these CPUs also function as mode setting means.

In step S704, auto focus is performed.

Specifically, upon receiving a detection signal output from the distance measuring circuit 92, the body-side CPU 91
The amount of defocus is calculated, and the driving amount of the motor 30 is calculated based on the calculation result. Body side CPU 9
The drive amount calculated in 1 is transmitted to the lens-side CPU 90. The lens-side CPU 90 drives the motor 30 using the driving amount.

When the motor 30 is driven, the torque of the motor shaft is transmitted to the gear 62 through the coupled couplers 61 and 63, and the gear 62 rotates the cam barrel 20. The second lens group moves in the direction of the optical axis in accordance with the rotation amount of the cam barrel 20, whereby focusing is performed.

On the other hand, in S705, a pulse signal from the rotary encoder 80 is detected. When the operation ring 40 is rotated, a pulse signal corresponding to the operation amount of the operation ring 40 is output from the rotary encoder 80,
When the lens side CPU 90 receives this pulse signal,
The motor 30 is driven based on the pulse signal. That is, even if the user rotates the operation ring 40, the actual lens driving is performed by the motor 30 as the driving force generating means according to the rotation direction and the rotation speed of the operation ring 40. Focusing in which the motor drives the lens according to the operation amount of the operation ring may be called, for example, power focus.

As described above, according to the present embodiment, there is no need to operate mechanical means when switching from auto-force to manual focus adjustment in the manual priority auto-focus mode. Therefore, the time required for switching can be shortened, and the mechanism of the lens barrel can be simplified.

In S707, it is detected whether or not the release button is half-pressed, and in S708, it is detected whether or not the release button is fully pressed. The detection is performed based on the ON / OFF signals of the switches 93 and 94 on the lens side CP.
U91 does it. If the release button is fully pressed,
Proceed to S710.

In step S710, general exposure processing is performed.

Through steps S702 and S703, even if the currently set focus mode is the M / A mode, M
If it is determined that the mode is not the F mode (that is, the mode is the AF mode), the process of S709 is executed. In S709, the same auto focus as in S704 is performed.

If it is determined in step S702 that the currently set focus mode is the MF mode, the flow advances to step S707.

In the MF mode, the coupler 33 and the coupler 61 are in a non-coupled state, and the pin 63 of the gear 64 is disposed in the notch 40b of the projection 40a. Therefore, when the operation ring 40 is rotated, this rotational force is transmitted to the cam cylinder 20 and focusing is performed.

[0040]

According to the present invention, autofocus is possible, but when the operation ring is operated, the lens is driven according to the operation amount of the operation ring (manual priority autofocus mode). In the above, when the operating ring is operated, the driving force generating means drives the lens.
This driving force generating means is also a driving source during auto focus.

With this configuration, it is possible to smoothly switch between lens driving in auto focus and lens driving in accordance with the operation amount of the operation ring without using a complicated mechanism.

[0042]

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view of a lens barrel according to an embodiment of the present invention.

FIG. 2 is a development view of a part of a cam mechanism provided in the lens barrel shown in FIG.

FIG. 3 is a configuration diagram of a rotary encoder included in the lens barrel shown in FIG.

FIG. 4 is a block diagram related to a control system of the camera according to the embodiment of the present invention.

5 is an explanatory diagram showing a waveform of a signal output from the rotary encoder shown in FIG.

FIG. 6 is a block diagram related to an optical system included in the camera according to the embodiment of the present invention.

FIG. 7 is a flowchart illustrating a focusing operation performed by the camera according to the embodiment of the present invention.

[Explanation of symbols]

10: fixed cylinder, 11: mount, 10a: small diameter part,
10b: large diameter portion, 10c: straight groove, 10d: stopper, 20: cam cylinder, 20a: cam groove, 20b: flange portion, 20c: gear portion, 30: motor, 3
1, 32, 62: gear, 33, 61: coupler, 4
0: operation ring, 40a: protrusion, 40b: notch, 5
0: switching member, 51: small switch, 60: clutch mechanism, 63: pin, 64: clutch ring,
65: engagement member, 66: spring, 70: first lens group, 71: second lens group, 72: third lens group, 7
3, 74, 75: lens group holding cylinder, 74a: cam pin, 80: rotary encoder, 81: brush,
82: annular substrate, 90: lens side CPU, 91: body side CPU, 92: distance measuring circuit, 93, 94: switch, 95: main mirror, 96: film surface,
97: sub mirror, 98: sensor module, 1
00: lens barrel, 200: camera body

Claims (5)

[Claims] 1. A lens driving device for driving a lens according to an operation amount of an operation ring when an operation ring is operated in a mode in which auto focus is possible, wherein the operation amount of the operation ring is detected. Detecting means for driving the lens to perform autofocus in the mode, and when the operating ring is operated in the mode, the lens according to the operation amount detected by the detecting means. And a driving force generating means for driving the lens. 2. A mode according to claim 1, wherein said mode enables auto-focusing in response to an external setting operation, and a manual focus-only mode allows said lens to be driven by a rotational force caused by manual operation of said operation ring. A lens driving device further comprising a mode setting means for selectively setting the lens driving mode. 3. The driving force according to claim 2, wherein a cam barrel for rotating the lens in the optical axis direction by rotating about the optical axis is provided, and wherein the mode capable of auto-focusing is set. A transmission mechanism for transmitting the driving force generated by the generation means to the cam barrel, and transmitting the rotational force of the operation ring to the cam cylinder when the manual focus only mode is set. A lens driving device. 4. A lens driving device according to claim 2, wherein said mode setting means can further set an auto-focus only mode in which only auto-focus can be performed. 5. An operating ring capable of rotating operation, a detecting unit for detecting an operation amount of the operating ring, a cam barrel for rotating a lens in an optical axis direction by rotating about an optical axis, and a rotating shaft. Having a motor, a switching member set to one of a plurality of preset positions prepared in advance, and when the switching member is set to a first setting position which is one of the plurality of setting positions, The operation ring and the cam barrel are connected to each other, and the motor shaft and the cam barrel are disconnected from each other, and the switching member is set to a second set position which is one of the plurality of set positions. In this case, the operating ring and the cam cylinder are disconnected from each other, and the clutch mechanism that connects the motor shaft and the cam cylinder is connected. The switching member is located at the second set position. The operation ring rotates when set. A lens drive device comprising: a control device that controls the motor in accordance with the operation amount detected by the detection unit when the rotation operation is performed.