JPH09145986A - Lens barrel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To arrange a focusing lock part to a desired position at the time of AF(autofocusing) without causing the cost to rise. SOLUTION: This lens barrel is equipped with a manual focusing ring 4 provided to be manually rotated around an optical axis and rotated to perform focusing operation; a focusing lock part 16 provided on the ring 4, rotated together with the ring 4 by the rotation of the ring 4, and holding a focusing state; and a focusing mode switching part 5 for switching the focusing mode to a manual focusing mode or an autofocusing mode. When the focusing mode is switched to the autofocusing mode side, the ring 4 is not rotated by autofocusing operation but can be rotated manually.

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 switching between auto focus and manual focus.

[0002]

2. Description of the Related Art FIGS. 3 and 4 are sectional views showing the structures of first and second examples of a conventional lens barrel of this type. In the figure, the alternate long and short dash line indicates the optical axis. In FIGS. 3 and 4, the fixing member 101 is a portion forming a base portion of the lens barrel. The left side of the fixing member 101 in the drawing holds a first lens group L1 which is one of the lens groups of the lens barrel,
The right side of the figure has a shape that can be connected to the camera body.

A selector switch 105 is a switch for switching between auto focus (AF) and manual focus (MF), and is attached to the outer peripheral portion of the lens barrel. The lock leaf spring 6 is attached to the changeover switch 105. The lock leaf spring 6 is
The position of the changeover switch 105 is held by engaging with the groove formed in the fixing member 101.

A manual focus ring (hereinafter referred to as "MF
Ring. ) 104 and 204 are for manually rotating around the optical axis when performing a focusing operation during MF, and are attached to the outer peripheral portion of the lens barrel. The focus lock button 16 is a button for stopping the focus operation by pushing it down in the drawing. The focus lock button 16 is arranged in the focus lock holder 17. The focus lock button 16 is biased by a biasing spring 18 in the radial outward direction of the lens barrel. A conductive member 19 is attached below the focus lock button 16. Further, the FPC 20 is attached on the fixing member 101. As a result, by pushing the focus lock button 16 toward the center, the conductive member 19 and the FPC are pressed.
20 comes into contact, and the focus lock signal is turned on.

Further, in the example of FIG. 3, the focus lock button 16 is provided so as to be exposed to the outer surface from a part of the MF ring 104. Therefore, the focus lock button 16 is rotated by the rotation of the MF ring 104 around the optical axis.
It is formed so as to rotate together with the MF ring 104. On the other hand, in the example of FIG. 4, a rotating member 205, which is separate from the MF ring 204 and is rotatable around the optical axis, is provided.
The focus lock button 16 is provided so as to be exposed to the outer surface from a part of the rotary member 205.

The driving force transmission member 7 is rotationally driven during AF and transmits the driving force transmitted from the camera body side to the lens barrel side. The AF rotation member 14 is rotated around the optical axis by the driving force from the driving force transmission member 7. The driving force transmission member 7 and the AF rotation member 14 are gear-coupled. The roller 9 includes an MF ring 104,
Friction contact is made so as to connect 204 and the AF rotating member 14. The roller 9 includes MF rings 104, 204 and A.
It is set so as not to slip with the F rotation member 14. The roller 9 is rotatably supported by a support shaft. The biasing spring 8 causes the AF rotating member 14 to move to the roller 9
The MF rings 104 and 204 are brought into frictional contact with the roller 9 and the roller 9 and the AF rotating member 14 by being urged to the side.

The focus rotation member 2 is used for AF and MF.
It is sometimes rotated around the optical axis, and the MF ring 104,
204 and the inside of the AF rotation member 14. The support shaft of the roller 9 is fixed to the focus rotation member 2. The support shafts of three rollers are fixed to the focus rotation member 2 at equal intervals in the circumferential direction. Further, the focus rotation member 2 is formed with a rectilinear groove extending in the optical axis direction.

The lens group is composed of a first lens group L1, a second lens group L2, and a third lens group L3.
Of these, the second lens unit L2 is a focusing lens unit,
It is arranged between the first lens unit L1 and the third lens unit L3. The second lens unit L2 performs focusing operation by moving in the optical axis direction (horizontal direction in the drawing).

The first lens unit L1 and the third lens unit L3
Are attached to the fixing member 101. The second lens unit L2 is held by the moving frame 12. The pin 11 is fixed to one end of the moving frame 12. Fixing member 101
Has a cam groove formed therein, and the pin 11 penetrates the cam groove. The upper end of the pin 11 is engaged with the straight groove of the focus rotation member 2. Two pins 11 are provided.

When the changeover switch 105 is changed over to the AF side (to the left in the drawing), the changeover switch 105
Is positioned by the lock leaf spring 6 and the groove formed in the fixing member 101, and the left end portion of the changeover switch 105 in the figure and the MF rings 104 and 204 are in contact with each other, and the MF ring 10
4,204 is locked. In this state, the driving force is transmitted to the driving force transmitting member 7, and the driving force transmitting member 7 is rotated. This rotation is transmitted to the AF rotating member 14, and the AF rotating member 14 is rotated around the optical axis. As a result, the roller 9 rolls between the AF rotating member 14 and the MF rings 104 and 204 without slipping. By the rolling motion of the roller 9, the roller 9 itself is moved around the optical axis, so that the focus rotation member 2 is rotated around the optical axis. At this time, the MF rings 104 and 204 maintain the locked state.

As a result, the pin 11 is formed by the rectilinear groove of the focus rotation member 2 and the cam groove of the fixed member 101.
It is moved along the optical axis. Therefore, since the second lens unit L2 is moved in the optical axis direction, the relative positions of the second lens unit L2 and the first lens unit L1 and the third lens unit L3 change, and focusing is performed.

On the other hand, when the changeover switch 105 is changed over to the MF side (rightward in the figure), the changeover switch 105 is positioned by the lock leaf spring 6 and the groove formed in the fixing member 101, and the changeover switch 105 and MF are positioned. The contact state with the rings 104 and 204 is released. Then, the changeover switch 105 and the AF rotating member 14 come into contact with each other, and the AF rotating member 14 is locked. In this state,
When the MF rings 104 and 204 are manually rotated by the photographer, the roller 9 rolls between the MF rings 104 and 204 and the AF rotating member 14 without slipping. At this time, the AF rotation member 14 maintains the locked state. As a result, the focus rotation member 2 is rotated and focusing is performed as in the AF operation described above.

[0013]

However, the above-mentioned conventional lens barrel has the following problems. In the first example of FIG. 3, the M switch is operated in conjunction with the changeover switch 105 during AF.
If the F ring 104 is fixed, there is a problem that the focus lock button 16 is not always fixed at a position where the photographer can easily operate. In order to solve this problem, it is conceivable to provide a plurality of focus lock buttons 16 on the outer peripheral surface of the MF ring 104, but this raises the cost and further reduces the operability during MF.

Further, as in the second example of FIG. 4, the MF ring 2
When the focus lock button 16 is provided on the rotating member 205 separate from 04, the focus lock button 16 is
The MF ring 204 can be arranged at an arbitrary position without depending on the rotation, but there is a problem that the number of parts increases and the cost increases. Further, the rotating member 205
Since it is provided on the outer peripheral portion of the lens barrel, if the focus lock button 16 is arranged at a position where operability is good, there is a problem in that the holdability of the lens barrel deteriorates.
Here, if the rotating member 205 is fixed (unrotatable),
There is a problem that the focus lock button 16 cannot be arranged at a position where it can be easily used by all photographers.

An object of the present invention is to make it possible to dispose the focus lock portion at a desired position during AF without increasing the cost.

[0016]

In order to solve the above-mentioned problems, the invention of claim 1 is provided so as to be manually rotatable around an optical axis, and a manual focus for performing a focusing operation by being rotated. A ring, provided on the manual focus ring, rotatable with the manual focus ring by rotation of the manual focus ring, and a focus lock unit for maintaining a focused state, and a focus mode of the manual focus mode or And a focus mode switching unit for switching to the autofocus mode, wherein the manual focus ring is not rotated by the autofocus operation and is manually rotatable when being switched to the autofocus mode side. It is characterized by

According to a second aspect of the present invention, in the lens barrel according to the first aspect, the lens barrel is in frictional contact with the manual focus ring so as to be rotatable about the optical axis and is switched to the manual focus mode side, A rotary ring is provided that can rotate integrally with the manual focus ring by frictional contact force with the manual focus ring, and when the mode is switched to the auto focus mode side, only the manual focus ring is rotatably fixed. Is characterized by.

According to a third aspect of the present invention, in the lens barrel according to the second aspect, the lens barrel is driven to rotate about the optical axis during autofocusing, and is fixed when switched to the manual focus mode side. And a rotating ring of
By rolling contact with the rotary ring and the second rotary ring to rotate the rotary ring or the second rotary ring, a rolling motion without sliding with respect to the rotary ring and the second rotary ring. And a rotator that is moved around the optical axis, and rotatably supports the rotator, and movably supports a focus lens group. By moving the rotator around the optical axis, the rotator moves around the optical axis. A focus lens support ring that moves the focus lens group when rotated is provided.

[0019]

DETAILED DESCRIPTION OF THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. 1 and 2 are sectional views showing an embodiment of a lens barrel according to the present invention. FIG. 1 shows a state when switching to the AF mode, and FIG. 2 shows a state when switching to the MF mode. In the lens barrel of FIG. 1, the same parts as those of the lens barrel shown in the conventional example are denoted by the same reference numerals, duplicate explanations will be omitted as appropriate, and parts different from the conventional example will be mainly described.

In FIG. 1, a focus lock button 16 is arranged on a part of the MF ring 4. A female screw is formed on the inner peripheral side of the MF ring 4. On the other hand, the friction setting ring 15 is a member formed in a ring shape, and a male screw is formed on the outer peripheral surface thereof. Then, the female thread of the MF ring 4 and the male thread of the friction setting ring 15 are screwed together.

The MF rotating member 3 is arranged on the inner peripheral side of the MF ring 4. A part of the MF rotating member 3 is in contact with the roller 9. On a part of the outer peripheral surface side of the MF rotating member 3,
A brim portion 3a is provided, and the brim portion 3a and the friction setting ring 15 are in contact with each other. Further, a brim portion 4a is provided on a part of the inner peripheral surface side of the MF ring 4, and a friction spring 21 is arranged between the brim portion 3a and the brim portion 4a. As a result, the MF rotating member 3 is biased toward the friction setting ring 15 side,
The rotating member 3 and the friction setting ring 15 are in frictional contact with each other. Therefore, by changing the mounting position of the friction setting ring 15, the contact force of the MF rotating member 3 with the friction setting ring 15 can be changed.

Next, the operation during AF / MF will be described. First, at the time of AF, the changeover switch 5 is moved to the AF side (left side in the drawing) as shown in FIG. As a result, the changeover switch 5 and the MF rotating member 3 come into contact with each other,
The MF rotating member 3 is locked. In this state, when the driving force is transmitted from the camera body side to the driving force transmission member 7, the AF rotation member 14 is rotated, the roller 9 rolls and moves around the optical axis, and the focus rotation member 2 rotates. Then, the focusing operation is performed. During this operation, the MF rotating member 3 remains locked. Therefore, the MF ring 4 does not rotate.

In this AF mode, the focus lock button 16 may be pushed to keep the in-focus state. At this time, the focus lock button 16 can be arranged at an arbitrary position by rotating the MF ring 4. That is, during AF, the MF ring 4 and the MF rotating member 3
Is in frictional contact with and stopped at a fixed position, but the MF ring 4
If a rotational force is applied to the MF ring 4 with a rotational torque that exceeds the static friction force between the MF ring member 3 and the MF ring member 3, only the MF ring 4 can be rotated.

During MF, the changeover switch 5 is moved to the MF side (right side in the figure) as shown in FIG. As a result, the contact state between the changeover switch 5 and the MF rotating member 3 is released, the changeover switch 5 and the AF rotating member 14 come into contact with each other, and the AF rotating member 14 is locked.
When the MF ring 4 is manually rotated in this state, the MF ring 4 is rotated.
Since the static friction force by the friction spring 21 acts on the MF rotating member 3 and the MF rotating member 3,
It is rotated integrally with the ring 4. As a result, the roller 9 rolls and moves around the optical axis, the focus rotation member 2 rotates, and a focusing operation is performed. During this operation, the AF rotation member 14 remains locked.

As is apparent from the above operation, the torque TL for rotating the MF ring 4 with respect to the MF rotating member 3 when the MF rotating member 3 is locked during AF.
And a torque TM for rotating the MF ring 4 integrally with the MF rotating member 3 during MF, a relationship of TL> TM is required. The position of the friction setting ring 15 is adjusted so that such a relationship is satisfied, and the MF ring 4 and the M ring are adjusted.
The frictional force with the F rotating member 3 may be set.

[0026]

According to the present invention, firstly, 1 on the MF ring.
Since one focus lock portion is provided, the lens barrel can be constructed at a low cost as compared with a case where a plurality of focus lock portions are provided or a case where it is provided on a rotating member separate from the MF ring. Second
In addition, since the MF ring is not rotated during AF but can be rotated manually, unnecessary rotation of the MF ring during AF can be eliminated and the focus lock portion on the MF ring can be arranged at a position where the photographer can easily use it. . Third, AF
From when using the focus lock in mode,
The MF mode can be quickly switched without changing the lens barrel, and the AF / MF operation can be performed smoothly.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a lens barrel according to the present invention, showing a state when switching to an AF mode.

FIG. 2 is a cross-sectional view showing an embodiment of the lens barrel according to the present invention, showing a state when the lens barrel is switched to the MF mode.

FIG. 3 is a cross-sectional view showing a configuration of a first example of a conventional lens barrel.

FIG. 4 is a sectional view showing a configuration of a second example of a conventional lens barrel.

[Explanation of symbols]

 1 Fixed Member 2 Focus Rotating Member 3 MF Rotating Member 4 MF Ring 5 Changeover Switch 6 Lock Leaf Spring 7 Driving Force Transmission Member 8 Energizing Spring 9 Roller 11 Pin 12 Moving Frame 14 AF Rotating Member 15 Friction Setting Ring 16 Focus Lock Button 19 Conductive member 20 FPC 21 Friction spring L1, L2, L3 Lens group

Claims (3)

[Claims] 1. A rotatably provided around an optical axis,
A manual focus ring for performing a focus operation by being rotated, and provided on the manual focus ring. The manual focus ring can be rotated together with the manual focus ring to maintain a focused state. And a focus mode switching unit for switching the focus mode to the manual focus mode or the auto focus mode.When the manual focus ring is switched to the auto focus mode side, The lens barrel is characterized in that it is not rotated and can be rotated manually. 2. The lens barrel according to claim 1, wherein when the lens barrel is in frictional contact with the manual focus ring so as to be rotatable about the optical axis and is switched to the manual focus mode side, A lens which is rotatable integrally with the manual focus ring by a frictional contact force, and is provided with a rotary ring in which only the manual focus ring is rotatably fixed when switched to the autofocus mode side. Lens barrel. 3. The lens barrel according to claim 2, further comprising: a second rotary ring that is driven to rotate about the optical axis during autofocus and fixed when switched to the manual focus mode side. By rolling contact with the rotary ring and the second rotary ring to rotate the rotary ring or the second rotary ring, a rolling motion without sliding with respect to the rotary ring and the second rotary ring. And a rotator that is moved around the optical axis, and rotatably supports the rotator, and movably supports a focus lens group. By moving the rotator around the optical axis, the rotator moves around the optical axis. By being rotated,
A lens barrel comprising: a focus lens support ring for moving the focus lens group.