JPH05134164A - Lens-barrel - Google Patents

Abstract

PURPOSE:To always operate a belt connecting mechanism also in the case of manual operation by providing an automatic-manual operation switching means in a mechanical sequence of the belt connecting mechanism and a motor. CONSTITUTION:When a manual operating member is rotated, an output gear 19 meshed with the manual operating member is rotated to rotate a pulley output gear 18 to which the output gear 19 is fixed. On the other hand, the pulley output gear 18 is connected to a pulley gear 16 by a belt 17 as an elastic member. By the tension of the belt 17, the pulley gear 16 and the pulley output gear 18 are forced to rotate while the side pressure is applied to a shaft 12a and a bearing 12b, respectively, that is, they are subjected to frictional force, Accordingly, as the moderate friction is applied to the rotation of the manual operation member, the manual operation feeling, that is, the operation having good manual feeling can be obtained. Since the pulley gear 16 is disconnected from a switching gear 15, the rotation of the manual operation member has no effect on an oscillatory wave motor A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens barrel capable of automatic / manual focus adjustment and the like, and is intended to improve the manual operation feeling during manual focus adjustment, that is, manual taste.

[0002]

2. Description of the Related Art Conventionally, in a lens barrel in which focus adjustment can be selectively performed by an automatic / manual operation mechanism, during automatic focus adjustment, the output of an automatic focusing motor is transmitted to a lens moving means by gear connection. On the other hand, when switching to the manual focus adjustment mode, it is common to disconnect the gear connection from the motor by an external operation, that is, to provide a switching clutch. Then, in that state, the manual ring was rotated to perform the manual focus operation.

[0003]

However, in the above-mentioned conventional example, when the manual focusing mode is switched, the manual focusing ring is disconnected from the motor, so that the manual ring is not loaded. The rotation torque of the ring was too light, which was not very preferable as the manual taste when adjusting the focus with the manual ring. Therefore, the manual ring itself must be configured to generate a friction force, but a friction member must be newly added, which is disadvantageous in terms of cost and space.

On the other hand, in order to make the rotating torque of the manual ring heavy, a lubricating member such as grease may be used. However, since the grease may spread to a portion of other mechanism where the grease cannot be attached, the grease may not be attached. There was a problem that it was difficult to control the coating amount.

[0005]

One example of a concrete means of a lens barrel for realizing the object of the present invention is a driving motor,
Between the power transmission mechanism having a belt coupling mechanism for transmitting the output from the motor, the lens moving means coupled to the output side of the power transmission mechanism to move the lens, and the lens moving means and the belt coupling mechanism. And an automatic / manual operation switching means for holding the connection state of the motor and the belt connection mechanism to be engaged / disengaged, and switching the automatic / manual operation switching means to the manual operation side. In this state, when the lens moving means is moved manually, the belt connecting mechanism is driven.

[0006]

In the lens barrel having the above-described structure, when the rotary barrel holding the focus lens is manually operated during manual operation, the belt connecting mechanism is also driven. That is, you will be able to enjoy good manualness.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on the embodiments shown in the drawings. 1, 2, 3, and 4 show the first embodiment.

FIG. 1 is a sectional view of a motor driving device provided in the lens barrel of the present invention in an automatic focusing mode.
2 is a cross-sectional view in the manual focusing mode, and FIG.
FIG. 3 is a cross-sectional view showing mounting on a lens barrel in each state. In the figure, 1 is a cylindrical vibrating elastic body made of a metal material, 2 is a pressing body made of a metal material having an outer diameter of the same shape as that of the vibrating elastic body 1, and 3a to 3d are outer diameters of the vibrating elastic body 1. The annular piezoelectric element plates 4a to 4d formed to have the same outer diameter as that of the piezoelectric element plates 3a to 3d are electrode plates, and the electrode plates are provided between the vibrating elastic body 1 and the pressing body 2. Four
a to 4d and piezoelectric element plates 3a to 3d are arranged, and the bolt 5 is screwed onto the vibrating elastic body 1 through the holding body 2
These are fixed together to form the stator of the ultrasonic motor A.

The ultrasonic motor A has a stator electrode plate 4a.
By applying alternating voltages having different phases from a power supply circuit (not shown) to 4d to 4d, the piezoelectric element plates 3a to 3d form mechanical vibrations in the stator, and by the combination of these vibrations, a movement like a rope jump is generated in the stator. The rotor 6 described below, which is excited and frictionally contacts the front end portion of the stator, is frictionally driven.

A rotor 6 has a rear end portion (friction contact portion) 6a.
Is brought into contact with the end portion 1a of the vibrating elastic body 1, and an appropriate frictional force is obtained by pressurization by a pressure spring 10 described later. Reference numeral 7 denotes a rotation output member made of a friction stabilizing material having a gear 7a, and frictionally coupled between the rear end surface and the end surface of the rotor 6. The gear 7a is for transmitting the rotation of the roller 6 to the outside. The friction force of the friction coupling between the rotor 6 and the rotation output member 7 is generated by the pressure spring 10, and the force is generated by the vibrating elastic body 1 and the rotor 6.
It is set so as to be smaller than the frictional force between (and the friction coefficient becomes smaller).

That is, even if a rotational force is externally applied to the rotary output member 7 during automatic focus adjustment, the rotor 6 does not rotate because the frictional force on the stator 6 is larger than the frictional force on the output member 7. Only 7 will rotate. On the other hand, a bearing 8 is provided in the inner diameter portion of the rotation output member 7, and a hollow shaft 9 is fitted in the inner diameter portion of the bearing 8 to allow the rotor 6 and the rotation output member 7 to rotate. The shaft 9 is fitted to the sliding portion 5a of the bolt 5 so as to be aligned with the shaft center of the stator. Reference numeral 10 denotes a pressure spring, which presses the step portion 9a of the shaft 9 to press the bearing 8 by the flange portion 9b, and the pressing force of the vibration elastic body 1 and the rotor 6, and the rotor 6 and the rotation output member 7. The frictional force is generated between them. Pressure spring 1
The pressing force of 0 is generated by inserting the hole portion 11a of the flat plate-shaped holding member 11 into the pin portion 5b formed at the tip of the bolt 5 and fixing it by a known method such as fixing with an adhesive. ing. The above is the configuration of the ultrasonic motor A.

The ultrasonic motor A is fixed by fixing the holding member 11 to the motor base plate 12 which is a fixing member with screws 13 and 14. When supporting the stator of the ultrasonic motor, it is necessary not to affect the vibration excited in the stator, the end of the stator is the antinode position of the vibration, and there is only a radial displacement. Moreover, since the displacement is actually very small, fixing it with the pin portion 5b, which is one end of the stator, does not affect the vibration of the stator.

Reference numeral 15 is a switching gear that meshes with the gear 7a of the rotation output member 7, and a mode switching spring 26 described later is fitted in the groove 15a. Reference numeral 16 denotes a pulley gear which meshes with the switching gear 15 and on which a belt 17 is applied. Reference numeral 18 denotes a pulley output gear on which the belt 17 is applied, and an output gear 19 is fixed to the other end.
Since the belt 17 is made of an elastic member, the pulley gear 16 and the pulley output gear 18 are subjected to lateral pressure by the elastic force of the shaft portion 12a and the bearing portion 12b, respectively.
Therefore, the pulley gear 16 and the pulley output gear 18 rotate while being given a rotational friction. The output of the ultrasonic motor can be transmitted to the lens barrel by rotating the gear 19.

A pulse plate 21 is fixed to the gear 20, and a gear 18 is provided.
This is a pulse gear that meshes with, and the pulse of the pulse plate 21 is read by the photocoupler 22 to detect the movement and position of the rotary cylinder (manual operation member 23) that is a driven member that is rotationally driven by the gear 19, for example. You can do it.

Reference numeral 23 is a manual operation member which is a rotary cylinder for focusing and holds a focus lens L. Reference numeral 24 is a fixed cylinder having a helicoid 24a that is helicoidally coupled with the helicoid portion 23a of the manual operation member 23,
Is a mode switching member for switching between automatic focus adjustment and manual focus adjustment, and 26 is a mode switching spring fixed to the mode switching member 25 with a screw 27, and has a fitting portion 26a fitted into the groove portion 15a of the switching gear 15. On the other hand, at the other end, click section 2 for clicking in the automatic mode or manual mode position.
6b. Reference numeral 28 is a support member having click grooves 28a and 28b into which the click portion 26b of the mode switching spring 26 is inserted and which fixes the fixed cylinder 24 with screws or the like. The automatic focus mode is set when the click portion 26b is inserted into the click groove 28a, and the manual focus mode is set when the click portion 26b is inserted into the click groove 28b.
The motor drive device shown in FIG. 1 is fixed to the fixed barrel 24 with screws 29 as shown in FIG.

Next, the operation will be described. 1 and 2 are diagrams when the automatic focusing mode is set, and FIGS. 3 and 4 are diagrams when the manual focusing mode is set.

First, the operation when the lens barrel is moved by using the vibration wave motor in the automatic focusing mode will be described with reference to FIGS. In this state, the mode switching member 25 is located closer to the left side because the click portion 26b of the mode switching spring 26 is inserted into the click groove 28a.
On the other hand, the switching gear 15 is gear-connected to the pulley gear 16 by the fitting portion 26a of the mode switching spring 26, as shown in FIG. Further, as shown in FIG. 2, the mode switching member 25 is located closer to the left side, so that the drive signal of the drive circuit (not shown) can be sent to the vibration wave motor A. When a lens drive signal is received from a drive circuit (not shown) in this state, an AC voltage is applied to the electrode plates 4a-4d, and the piezoelectric element plates 3a-3d generate mechanical vibrations. As a result, the stator vibrates and the rotor 6 rotates. The rotation output member 7 frictionally coupled by the rotation of the rotor 6 also rotates. The rotation output is transmitted to the switching gear 15 and the pulley gear 16. Since the pulley gear 16 and the pulley output gear 18 are belt-coupled by the belt 17, the rotation of the pulley gear 16 is transmitted to the pulley output gear 18, and the rotation of the output gear 19 rotates the manual operation member (rotary cylinder) 23. Let The focus lens L is arranged on the manual operation member (rotary cylinder) 23, while the helicoid portion 24a and the helicoid portion 23a of the fixed cylinder 24 are helicoidally coupled, so that the manual operation member (rotary cylinder) 23 is Focusing can be performed by moving back and forth while rotating. The position and speed of the rotor 6 and the manual operation member (rotary cylinder) 23 are detected by the pulse gear 2 that meshes with the pulley output gear 18.
With the rotation of 0, the pulse plate 21 and the photo coupler 22 detect.

Next, the operation when the manual operation member 23 is rotated in the manual focusing mode will be described with reference to FIGS. In this state, the mode switching member 25 is located closer to the right side because the click portion 26b of the mode switching spring 26 is inserted into the click groove 28b. On the other hand, the fitting portion 26a of the mode switching spring 26 disconnects the switching gear 15 from the pulley gear 16 and holds it in that state, as shown in FIG.

Further, since the mode switching member 25 is located closer to the right side as shown in FIG. 3, the drive signal of the drive circuit (not shown) is not transmitted to the vibration wave motor A. When the manual operation member 23 is rotated in this state, the helicoid couplings 23a and 24a allow the manual operation member 23 itself to rotate and move back and forth for focusing.

On the other hand, when the manual operation member 23 is rotated, the output gear 19 meshing with the manual operation member 23 is rotated, and the pulley output gear 18 fixed to the output gear 19 is also rotated. On the other hand, as shown in FIG. 3, the pulley output gear 18 is belt-connected to the pulley gear 16 by a belt 17 which is an elastic member. Due to the tension of the belt 17, the pulley gear 16 and the pulley output gear 18 respectively have the shaft 12a,
The bearing 12b rotates while applying a lateral pressure, that is, receiving a frictional force. Therefore, the manual operation member 23
Since an appropriate friction is imparted to the rotation of, it is possible to obtain a manual operation feeling, that is, an operation with a good manual taste. Since the pulley gear 16 is disconnected from the switching gear 15, the rotation of the manual operation member 23 has no influence on the vibration wave motor A.

5 and 6 show a second embodiment.

In the first embodiment, since the manual operation member also serves as the rotary cylinder, the manual operation member rotates even during automatic focus adjustment. However, during automatic focus adjustment, the manual operation member, that is, the manual ring. Needless to say, the structure of the present invention can be mounted on a model that does not rotate.

An example thereof is shown in FIGS. FIG. 5 is a diagram when the manual focusing mode is set. 101 is a switching gear 15
And a contact gear that can be engaged only in manual focusing mode, 10
Reference numeral 2 is a manual input gear that is fixed to the connecting gear 101 and meshes with a gear portion 103a of a manual ring 103 described later. Reference numeral 103 is a manual ring that is fitted to the fixed ring 104 and the support member 28 and is rotatable about the optical axis. Part 1
03a. A fixed ring 104 is fixed to the support member 28. Reference numeral 105 is a rotary cylinder, and the output gear 19
It has a helicoid portion 105a that meshes with. Next, the operation by manual focus adjustment in the manual focusing mode will be described. In this state, the mode switching member 25 is located closer to the right side because the click portion 26b of the mode switching spring 26 is inserted into the click groove 28b.

On the other hand, by the fitting portion 26a of the mode switching spring 26, the switching gear 15 is moved to the connecting gear 101 as shown in FIG.
, And the gear connection with the rotation output member 7 of the vibration wave motor A is disconnected. Further, since the mode switching member 25 is located closer to the right side as shown in FIG. 6,
The drive signal of the drive circuit (not shown) is not transmitted to the ultrasonic motor A. When the manual ring 103 is rotated in this state, the manual input gear 102 meshing with the manual ring 103 is rotated. Communication gear 1 accompanying it
01, the switching gear 15, and the pulley gear 16 rotate. On the other hand, the pulley gear 16 is belt-connected to the pulley output gear 18 by an elastic belt 17. The tension of the belt 17 causes the pulley gear 16 and the pulley output gear 18 to rotate while applying lateral pressure to the shaft 12a and the bearing 12b, that is, receiving a frictional force. The rotation of the pulley output gear 18 depends on the output gear 19
Thus, the rotary cylinder 105 is rotated. The rotating cylinder 105 can be moved back and forth while rotating by helicoid coupling 105a, 24a with the fixed cylinder 24 to perform focusing. Therefore, since the frictional force due to the lateral pressure in the belt connection described above is applied as an appropriate frictional force to the rotation of the manual ring 103, a feeling of manual operation, that is, an operation with a good manual taste can be obtained.

When switching to the automatic focusing mode in this embodiment, the mode switching member 25 is operated to the left side,
Click groove 26 of mode switching spring 26 Click groove 2
8a, while the fitting portion 26a allows the switching gear 1 to be inserted.
5 is separated from the connecting gear 101 and meshed with the rotation output member 7 of the ultrasonic motor A. Thereby, the rotation output member 7, the switching gear 15, the pulley gear 16, the belt 1
7, pulley output gear 18, output gear 19, rotary cylinder 10
5 is mechanically connected to enable automatic focus adjustment.

Further, in each of the above-described embodiments, the focus adjustment has been described as an example, but the zoom adjustment may be performed.

[0027]

As described above, according to the present invention, since the automatic / manual operation switching means is provided in the mechanical sequence of the belt connecting mechanism and the motor, the belt connecting mechanism is always operated even in the manual operation. And the frictional force between the pulley and its shaft due to the tension of the belt can provide an appropriate friction force as a manual ring torque.

Since the output from the motor at the time of automatic focus adjustment is transmitted to the lens moving means via the belt connecting mechanism,
It produces less sound compared to gear connection and can provide silent automatic focusing drive.

Further, since only a part of the gear train is changed to the belt connection, it can be constructed in the same space and cost as the conventional type.

Further, it is possible to prevent the rotation of the manual operation means during the automatic operation.

[Brief description of drawings]

FIG. 1 is a sectional view of a motor driving device incorporated in a lens barrel showing a first embodiment in an automatic focusing mode.

FIG. 2 is a sectional view of the lens barrel of the first embodiment in an automatic focusing mode.

FIG. 3 is a cross-sectional view of the motor driving device incorporated in the lens barrel showing the first embodiment in a manual focusing mode.

FIG. 4 is a sectional view of the lens barrel of the first embodiment in a manual focusing mode.

FIG. 5 is a sectional view of a motor drive unit incorporated in a lens barrel showing a second embodiment in a manual focusing mode.

FIG. 6 is a sectional view of a lens barrel showing a second embodiment.

[Explanation of symbols]

A ... Ultrasonic motor 1 ... Oscillator 6 ... Rotor 7 ... Rotation output member 12 ... Motor base plate 12a ... Shaft 12b ... Bearing 15 ... Switching gear 16 ... Pulley gear 17 ... Belt 18 ... Pulley output gear 19 ... Output gear 23 ... Manual operation Member 24 ... Fixed tube 25 ... Mode switching member 26 ... Mode switching spring 28 ... Support member 101 ... Connection gear 102 ... Manual input gear 103 ... Manual ring 104 ... Fixed ring 105 ... Fixed tube

Claims (3)

[Claims] 1. A driving motor, a power transmission mechanism having a belt coupling mechanism for transmitting an output from the motor, a lens moving means for moving a lens in connection with an output side of the power transmission mechanism, An automatic / manual operation switching means for holding the connection state between the lens moving means and the belt connecting mechanism to enable engagement / disengagement of the connection between the motor and the belt connecting mechanism; A lens barrel characterized in that, when the manual operation switching means is switched to the manual operation side, the belt connecting mechanism is driven when the lens moving means is moved by manual operation. 2. A driving motor, a power transmission mechanism having a belt coupling mechanism for transmitting an output from the motor, a lens moving means for moving a lens by coupling with an output side of the power transmission mechanism, An automatic / manual operation switching means for holding a connection state between the lens moving means and the belt connecting mechanism to enable engagement / disengagement of the connection between the motor and the belt connecting mechanism, and the automatic / manual operation. A lens barrel comprising: a manual operating means for moving the lens moving means via the belt connecting mechanism in a state where the switching means is switched to the manual operating side. 3. The lens barrel according to claim 1 or 2, wherein the driving motor is a rod-shaped ultrasonic motor.