JP7048071B2 - Lens barrel - Google Patents

Description

The present invention relates to an interchangeable lens barrel provided with position detection of a movable lens group such as focusing and zooming by using a brush and an encoder having a pattern formed on a printed circuit board.

In the interchangeable lens barrel, a position detection device for the movable lens group is required to control the position of the movable lens group such as a focus lens and a zooming lens. Patent Document 1 discloses an example of a position detecting device.

In the position detection device disclosed in Patent Document 1, an encoder in which a pattern is formed on a flexible printed substrate is attached to a fixed cylinder, and a brush fixed to a rotating cylinder that rotates on the pattern during zooming or focusing is used. By sliding, the pattern is read and the position of the movable lens group is detected.

Japanese Unexamined Patent Publication No. 2004-37825

However, in the position detection device disclosed in Patent Document 1, when the brush is fixed to the distance ring when the lens barrel is assembled, and then the brush is incorporated into the fixed cylinder, the tip of the brush becomes the fixed cylinder or the like. It has a problem that it bends when it comes into contact with.

Therefore, the position detection device disclosed in Patent Document 1 is a fixed cylinder provided with an encoder in which a pattern is formed on a flexible printed substrate in order to prevent the tip of the brush from bending during assembly. After incorporating the distance ring, the brush was fixed in that order.

Further, there is a problem that the tip of the brush bends when it touches the surrounding parts at the time of disassembling as well as at the time of assembling.

Therefore, when disassembling, remove the brush from the distance ring and then remove the distance ring from the fixed cylinder, which is the opposite of when assembling. In addition, when fixing the brush to the distance ring during assembly, some adjust the contact between the brush and the encoder before fixing it. Then, there is a problem that it is necessary to adjust again every time it is reassembled.

The present invention has been made in view of such a situation, and an object of the present invention is to provide a lens barrel that is easy to assemble and disassemble and that does not damage the tip of the brush.

The first invention, which is a means for solving the above-mentioned problems, includes a lens position detecting means for detecting the position of a movable lens by detecting an electric signal obtained by a change in the contact position between the brush and the pattern electrode. In the lens lens barrel, a rotary cylinder that can rotate around the optical axis in conjunction with an operation in which the user rotates the movable lens in a direction along the optical axis, and the rotary cylinder. The lens has a fixed cylinder that holds the lens in the radial direction, and one of the rotary cylinder and the fixed cylinder is attached with the brush and the claw portion, and the tip portion of the brush is the rotary cylinder and the fixing portion. Protruding to the other side of the cylinder, the claw portion is arranged in phase with the tip portion of the brush and around the optical axis, and the other of the rotating cylinder and the fixed cylinder comes into contact with the brush in the circumferential direction of the optical axis. The pattern electrode is attached and fixed, and a groove is provided around the end of the pattern electrode, the groove is connected to the rotary cylinder and the other of the fixed cylinder by a curved surface, and the claw portion is more than the brush . A lens barrel characterized by projecting into the groove.

The second invention, which is a means for solving the above-mentioned problems, is a lens position detecting means for detecting the position of a movable lens by detecting an electric signal obtained by a change in the contact position between the brush and the pattern electrode. A rotating cylinder that can rotate around the optical axis in conjunction with an operation in which the user rotates the movable lens around the optical axis when the movable lens is moved in a direction along the optical axis. It has a fixed cylinder that holds the rotary cylinder in the radial direction, and the brush is attached to either the rotary cylinder or the fixed cylinder, and the tip of the brush is the rotary cylinder and the fixed cylinder. The other of the rotary cylinder and the fixed cylinder, which protrudes to the other side of the cylinder, has a first groove portion that avoids the brush, and one of the rotary cylinder and the fixed cylinder has a claw portion, and the rotary cylinder has a claw portion. And the other of the fixed cylinder has a second groove portion for guiding the claw portion, and the other of the rotating cylinder and the fixed cylinder is fixed by attaching a pattern electrode that comes into contact with the brush in the optical axis circumferential direction. The first groove portion is located around the end portion of the pattern electrode, and the first groove portion is connected to the other of the rotary cylinder and the fixed cylinder by a curved surface, and is connected to the second groove portion of the claw portion. The amount of protrusion of the lens barrel is larger than the amount of protrusion of the brush to the first groove portion.

According to the present invention, it is possible to provide a lens barrel that is easy to assemble and disassemble and that does not damage the tip of the brush.

Sectional drawing of the lens mirror which concerns on embodiment of this invention Configuration diagram at the time of assembling the fixed cylinder, scale ring and its accessory parts according to the embodiment of the present invention. Cross-sectional view in a state where the fixed cylinder and the scale ring according to the embodiment of the present invention are assembled. Enlarged view around the groove in the state where the fixed cylinder and the scale ring according to the embodiment of the present invention are assembled.

Hereinafter, the best mode for carrying out the present invention will be described with reference to the accompanying drawings. The present invention is not limited to this embodiment.

FIG. 1 is a cross-sectional view of the lens barrel of this embodiment. Note that FIG. 1 has been simplified to simplify the description of the present invention. Unless otherwise specified, the left side of each figure is the subject side and the right side is the image side.

In this embodiment, 100 is a lens barrel, 101 is an operation ring rubber, 102 is an operation ring, 103 is a motor base, 104 is a fixed cylinder, 105 is a scale ring, 106 is a rotary cylinder, and 107 is a moving group. Let O be the optical axis of the cylinder 100. The optical axis O is shown only in FIG.

The lens barrel 100 is removable from a camera body (not shown), and the mount portion of the lens barrel 100 and the mount portion of the camera body are connected by a bayonet mechanism or the like.

The operation ring rubber 101 is located on the outer periphery of the operation ring 102 and is integrated with the operation ring 102. Therefore, when the user operates the operation ring rubber 101, the lens barrel is integrated with the operation ring 102. Move in the circumferential direction of 100.

The operation ring 102 is appropriately operated in the circumferential direction when the user adjusts focusing or zooming.

The motor base 103 is located on the optical axis O side of the operation ring 102, and is fastened to the fixed cylinder 104 with screws.

The fixed cylinder 104 is fastened to the motor base 103 with screws. An encoder 1041 having a pattern formed on a flexible printed substrate is attached to the outer peripheral portion of the fixed cylinder 104. Further, a groove portion 1042 and a protrusion portion 1043 are provided.

The scale ring 105 moves in the circumferential direction around the optical axis O of the lens barrel 100 in conjunction with the operation ring 102. Further, a brush 1051 is provided at a portion overlapping with the fixed cylinder 104.

The rotary cylinder 106 moves in the circumferential direction around the optical axis O of the lens barrel 100 in conjunction with the operation ring 102 and the scale ring 105. The input rotation is transmitted to the moving group 107.

The moving group 107 is a lens group that moves when adjusting focusing and zooming. When the user operates the operation ring 102, the moving group 107 to which the input rotation is transmitted moves the lens barrel 100 along the optical axis O.

Next, FIG. 2 is a configuration diagram of the fixed cylinder 104, the scale ring 105, and their accessory parts at the time of assembly. Note that O in FIG. 2 indicates the optical axis of the lens barrel 100.

A position detecting device for detecting the lens position of the moving group 107 will be described with reference to FIG.

In the position detecting device for detecting the lens position of the moving group 107 used in the lens barrel 100 of the present application, the encoder 1041 is attached to the fixed cylinder 104 as described in Patent Document 1, and the end of the encoder 1041 is attached. A groove portion 1042 is provided around the portion. A scale ring 105 is arranged on the outer circumference of the fixed cylinder 104. The scale ring 105 includes a brush 1051.

When the user rotates the operation ring rubber 101 in the circumferential direction about the optical axis O during focusing and zooming adjustment, the rotation is transmitted to the scale ring 105 via the operation ring 102. The scale ring 105 to which the rotation is transmitted rotates in the circumferential direction together with the provided brush 1051. At this time, the tip of the brush 1051 slides on the pattern of the encoder 1041. At the same time, the rotation input by the user is transmitted to the moving group 107 via the rotary cylinder 106, and the moving group 107 moves along the optical axis O.

Therefore, the position of the moving group 107 can be specified by reading the pattern of the encoder 1041 in which the tip of the brush 1051 is stopped.

Next, how to assemble the fixed cylinder 104 and the scale ring 105 will be described with reference to FIG.

In FIG. 3, the fixed cylinder 104 and the scale ring 105 are assembled with the scale ring 105 to which the brush 1051 is screwed and the fixed cylinder 104 so that the relationship between the brush 1051 and the encoder 1041 can be seen. It is a figure cut in a vertical plane. The upper left is the subject side and the lower right is the image side.

To assemble, fasten the brush 1051 to the scale ring 105 with a screw or the like. The scale ring 105 integrated with the brush 1051 aligns the tip of the brush 1051 with the groove portion 1042 and the optical axis O in the same phase, and then engages the scale ring 105 with the fixed cylinder 104. At this time, the tip of the brush 1051 does not come into contact with the fixed cylinder 104. Details will be described later.

After engaging the fixed cylinder 104 and the scale ring 105, when the scale ring 105 is rotated clockwise, the tip of the brush 1051 slides on the encoder 1041. The integrated fixed cylinder 104 and scale ring 105 are incorporated into the lens barrel 100.

Next, it will be described with reference to FIG. 4 that the tip of the brush 1051 and the fixed cylinder 104 do not come into contact with each other.

FIG. 4 is a view of the tip of the brush 1051 and the groove 1042 viewed from a position parallel to the optical axis O in a state where the scale ring 105 and the fixed cylinder 104 are assembled as in FIG. Although not shown in FIG. 4, the optical axis O is located on the lower side outside FIG.

The scale ring 105 is provided with a bayonet claw 1052 (hatched portion in FIG. 4) on the inner diameter side. The bayonet claw 1052 is located in phase with the brush 1051 and the optical axis O, and protrudes toward the optical axis O from the tip of the brush 1051 as shown in FIG. Therefore, at the time of assembly, the bayonet claw 1052 acts as a guide by engaging with the groove 1042 before the tip of the brush 1051 comes into contact with the groove 1042. Therefore, the brush 1051 does not come into contact with the groove 1042 or surrounding parts.

Further, after engaging the scale ring 105 with the fixed cylinder 104, when the tip of the brush 1051 is moved onto the encoder 1041 in order to function as a position detecting device, the bayonet claw 1052 becomes the protrusion 1043 of the fixed cylinder 104. Will engage with. As a result, the movement of the scale ring 105 in the direction along the optical axis is restricted, so that the scale ring 105 and the fixed cylinder 104 do not come off.

From the above, the configuration of the present invention solves the problem that the brush 1052 bends due to contact with peripheral parts during assembly.

Further, the groove portion 1042 provided in the fixed cylinder 104 will be described. The side surface of the groove portion 1042 is a curved surface. As a result, when the brush 1051 is moved from the state shown in FIG. 3 or 4 to the state where the brush 1051 slides with the encoder 1041 at the time of assembly (the fixed cylinder 104 is fixed and the scale ring 105 is fixed from the state shown in FIG. 3 or 4). The tip of the brush 1051 moves to the encoder 1041 along the curved surface of the groove 1042, so that there is no risk of the tip of the brush 1051 being bent due to being caught by surrounding parts or the like.

So far, we have described the time of assembly. The time of disassembly is the same as that of assembly.

Another embodiment will be described.

In the examples so far, the brush 1051 and the bayonet claw 1052 are arranged at positions in phase with respect to the optical axis O. As a result, by sharing the groove 1042 of the fixed cylinder 104 both during assembly and disassembly, there was no problem with only one groove 1042. However, even if the brush 1051 and the bayonet claw 1052 are arranged in different phases, the groove portion 1042 is arranged in each. That is, the effect of the present invention can be obtained by arranging the first groove portion and the second groove portion on the circumference of the fixed cylinder 104.

Specifically, it is desirable that the first groove portion used by the brush 1051 at the time of assembly / disassembly is near the end portion of the encoder 1041. This is because if there is a distance between the first groove portion and the encoder 1041, the brush 1051 must be moved to the encoder 1041 by that distance, which is not desirable.

Further, the second groove portion with which the bayonet claw 1052 engages at the time of assembly / disassembly may be located anywhere on the circumference of the fixed cylinder 104 as long as there is no obstacle such as the encoder 1041.

Further, the side surface of the second groove portion used by the bayonet claw 1052 does not have to be a surface because the tip of the brush 1051 does not slide.

So far, an embodiment has been described in which the encoder 1041 and the groove portion 1042 are arranged on the fixed cylinder 104, and the brush 1051 and the bayonet claw 1052 are arranged on the scale ring 105. However, there is no problem even if the brush 1051 and the bayonet claw 1052 are arranged on the outer periphery of the fixed cylinder 104, and the encoder 1041 and the groove portion 1042 are arranged on the inner circumference of the scale ring 105.

Further, in another embodiment, the brush 1051 and the bayonet claw 1052 may be arranged separately from the fixed cylinder 104 and the scale ring 105, respectively. In that case, the protrusion 1043 that engages with the bayonet claw 1052 is on the same side as the brush 1051. For example, when the brush 1051 is arranged in the fixed cylinder 104 and the bayonet claw 1052 is arranged in the scale ring 105, the first groove portion is arranged in the scale ring 105, and the second groove portion and the protrusion 1043 are arranged in the fixed cylinder 104.

On the contrary, when the brush 1051 and the bayonet claw 1052 are arranged on the scale ring 105 and the fixed cylinder 104, respectively, the first groove portion is arranged on the fixed cylinder 104, and the second groove portion and the protrusion 1043 are arranged on the scale ring 105.

Further, the embodiment described in the specification of the present application has a configuration in which the scale ring 105 is provided on the outer peripheral side of the fixed cylinder 104 from each drawing. However, the scale ring 105 may be provided on the inner peripheral side of the fixed cylinder 104. In that case, as shown in FIG. 2, the scale ring 105 is divided into a scale portion and a brush 1051 portion, and a rotating cylinder that requires a scale portion and rotates in conjunction with the scale ring is arranged on the outer peripheral side of the fixed cylinder 104. It may be changed as appropriate.

100 Lens barrel 101 Operating ring Rubber 102 Operating ring 103 Motor base 104 Fixed cylinder 1041 Encoder 1042 Groove 1043 Protrusion 105 Scale ring 1051 Brush 1052 Bayonet claw 106 Rotating cylinder 107 Moving group

Claims (2)

In a lens barrel provided with a lens position detecting means for detecting the position of a movable lens by detecting an electric signal obtained by a change in the contact position between the brush and the pattern electrode.
A rotating cylinder that can rotate around the optical axis in conjunction with the operation of the user rotating the movable lens in the direction along the optical axis.
A fixed cylinder that holds the rotary cylinder in the radial direction,
Have,
The brush and the claw portion are attached to either the rotary cylinder or the fixed cylinder.
The tip of the brush protrudes to the other of the rotary cylinder and the fixed cylinder, and
The claw portion is arranged in phase with the tip portion of the brush and around the optical axis.
The pattern electrode that comes into contact with the brush in the circumferential direction of the optical axis is attached and fixed to the other of the rotary cylinder and the fixed cylinder.
A groove is provided around the end of the pattern electrode.
The groove portion is connected to the other of the rotary cylinder and the fixed cylinder by a curved surface.
The lens barrel is characterized in that the claw portion protrudes into the groove portion from the brush portion. In a lens barrel provided with a lens position detecting means for detecting the position of a movable lens by detecting an electric signal obtained by a change in the contact position between the brush and the pattern electrode.
A rotating cylinder that can rotate around the optical axis in conjunction with the operation of the user rotating the movable lens in the direction along the optical axis.
A fixed cylinder that holds the rotary cylinder in the radial direction,
Have,
The brush is attached to either the rotary cylinder or the fixed cylinder.
The tip of the brush protrudes to the other of the rotary cylinder and the fixed cylinder, and
The other of the rotary cylinder and the fixed cylinder has a first groove portion that avoids the brush.
Either the rotary cylinder or the fixed cylinder has a claw portion and has a claw portion.
The other of the rotary cylinder and the fixed cylinder has a second groove portion for guiding the claw portion.
A pattern electrode that comes into contact with the brush in the circumferential direction of the optical axis is attached and fixed to the other of the rotary cylinder and the fixed cylinder.
The first groove portion is located around the end portion of the pattern electrode.
The first groove portion is connected to the other of the rotary cylinder and the fixed cylinder by a curved surface.
A lens barrel characterized in that the amount of protrusion of the claw portion to the second groove portion is larger than the amount of protrusion of the brush to the first groove portion.

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