JP2005284144A - Lens-barrel and optical apparatus having lens-barrel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens-barrel which can reduce an occupying area seen from the optical axis direction of a driving part of an optical element, which can be miniaturized, and an optical apparatus which has the lens-barrel therefor. <P>SOLUTION: In a lens-barrel (5, 6, 9) having a plurality of driving parts to drive an optical element, as a plurality of the driving parts, for example, driving parts (16, 29) for driving two or more lenses, a driving part for a light quantity adjusting device (20) or the like are positioned in a line almost parallel to the optical axis direction. Thereby, the cross section seen from the lens optical axis direction is reduced, the driving part can be arranged at the lens inside diameter side, and the lens-barrel can be miniaturized. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a lens barrel having a drive unit that drives optical elements such as a focus lens and a zoom lens in an optical axis direction, and an optical apparatus including the lens barrel.

  Conventional lens barrels are known in which the drive units are arranged so as not to overlap when viewed from the optical axis direction. For example, in what is proposed in Patent Document 1, an arrangement configuration as shown in FIG. 8 is adopted. 8A is a front view of the objective lens as viewed from the object side, FIG. 8B is a rear view of the lens barrel, FIG. 8C is a side view of the lens barrel, and FIG. 8D is a cross-sectional view as viewed from the image side. It is.

  In FIG. 8, 81 is an objective lens, 82 is an iris actuator, 83 is a zoom actuator, 84 is a focus actuator, and 85 is a rear lens barrel. Reference numeral 86 denotes a zoom position detection sensor substrate, and reference numeral 87 denotes a focus position detection sensor substrate. Reference numeral 88 is a zoom lens group frame, 89 is a straight guide bar for the zoom lens group frame 88, 810 is a focus lens group frame, and 811 is a straight guide for the focus lens group frame 810. The bar. Reference numeral 812 denotes a stabilization bar for the zoom lens group frame 88 and the focus lens group frame 810. 813 is a rack and 814 is a screw.

As described above, in the lens barrel disclosed in Patent Document 1, the driving units such as the iris actuator 82, the zoom actuator 83, and the focus actuator 84 are arranged so as not to overlap each other when viewed from the optical axis direction.
Japanese Patent No. 3352295

  However, in the above conventional example, the drive units such as the iris actuator, the zoom actuator, and the focus actuator are arranged so as not to overlap when viewed from the optical axis direction. Space was taken separately, and the lens barrel was increased in size. That is, the guide bar of the lens group frame that uses a space in the optical axis direction, the sleeve portion provided in the lens group frame that fits with these bars, the iris actuator, the zoom actuator, Since it cannot be placed at a position that overlaps the drive unit such as a focus actuator, if these drive units are placed at different positions when viewed from the optical axis direction, the inner diameter side, that is, in the vicinity of the optical element, or the extension of the optical axis There is no space to arrange in the vicinity of the line, and it is necessary to dispose these drive units on the outer diameter side of the lens. Therefore, the area occupied by these drive units as viewed from the optical axis direction of the lens increases, and the lens mirror This was the cause of the large cylinder.

  Therefore, in view of the above problems, the present invention can reduce the occupied area of the optical element driving unit viewed from the optical axis direction, and can reduce the size of the lens barrel. An object of the present invention is to provide an optical apparatus having the same.

The present invention provides a lens barrel configured as follows and an optical apparatus having the lens barrel.
That is, the lens barrel of the present invention has a plurality of optical elements and a plurality of drive units that drive the plurality of optical elements in the optical axis direction, and at least two of the plurality of drive units are It is configured to be arranged on a straight line substantially parallel to the optical axis direction.

  According to the present invention, it is possible to reduce the occupied area of the optical element driving unit viewed from the optical axis direction, and to realize a lens barrel that can be reduced in size, and an optical apparatus having the lens barrel. can do.

  The best mode for carrying out the present invention will be described by the following examples.

[Example 1]
In the first embodiment of the present invention, a lens barrel is configured by applying the above-described configuration of the present invention. In this embodiment, when the configuration of the present invention is applied, at least two of the plurality of driving units described above can be configured by a focus lens driving unit and a zoom lens driving unit. Further, at least two of the plurality of driving units described above can be configured to be disposed at a distance closer to the optical axis than the radius of the lens included in the lens barrel.
In this embodiment, the focus lens, a focus lens drive unit that drives the focus lens in the optical axis direction, a zoom lens, and a zoom lens drive unit that drives the zoom lens in the optical axis direction, , An iris and an iris drive unit that drives the iris for light amount adjustment, and the focus lens drive unit, the zoom lens drive unit, and the iris drive unit are substantially parallel to the optical axis direction. It can be configured to be arranged on a straight line.

Next, these specific configurations will be described with reference to the drawings.
Here, FIG. 1 is a sectional view of the present embodiment, FIG. 2 is a perspective view of the present embodiment viewed obliquely from above in the optical axis direction, and FIG. 3 is an exploded perspective view for explaining the present embodiment. In these drawings, the stepping motor fixed to the first lens barrel, the drive unit of the light amount adjusting device attached to the third lens barrel, and the stepping motor fixed to the fixed barrel are respectively shown in the optical axis direction. A configuration example of this embodiment is shown in which the lens barrel is arranged so as to overlap with the lens barrel so as to reduce the size of the lens barrel.

In these figures, 1 is the first lens group closest to the object side, 2 is the second lens group that moves in the optical axis direction during zooming, 3 is the third lens group, and 4 is when zooming and during focus adjustment. It is the 4th lens group which moves to an optical axis direction.
5 is a fixed lens barrel fixed to a camera body (not shown), 6 is a first lens barrel that holds the first lens group 1 and is joined by a bayonet 5a and a bayonet 6a of the fixed lens barrel 7, and 7 is fixed at both ends. The bar is sandwiched between the lens barrel 5 and the first lens barrel 6 and is rotatably held. The bar has a feed screw portion 7a and a gear portion 7b.

Reference numeral 8 denotes a bar that is rotatably held between both ends of the fixed barrel 5 and the first lens barrel 6, and has a feed screw portion 8a and a gear portion 8b.
9 holds the second lens group 2, the sleeve portion 9 a is engaged with the bar 7, is held so as to be rotatable and movable in the optical axis direction, and the U-groove portion 9 b is engaged with the bar 8 to be restricted in rotation. The second lens barrel 10 is a second lens rack for driving the second lens barrel 9 in the optical axis direction. The second lens barrel 10 is rotatably held by the rack fastening portions 9c and 9d of the second lens barrel 9. Yes.

A rack spring 11 is hung on the second lens rack 10, and the second lens rack 10 is shifted to the second lens barrel 9, and the engagement portion with the feed screw 7 a of the second lens rack 10 is sandwiched between the backlashes. Engage without any problems.
A photo reflector 12 is fixed to the first lens barrel 6 and detects the position of the second lens barrel 9.
13 is a gear holding member fixed to the first lens barrel 6, 14 is a gear held between the first lens barrel 6 and the gear holding member 13, and meshes with the gear 7b of the bar 7, and 15 is the first lens. The gear is held between the lens barrel 6 and the gear holding member 13 and meshes with the gear 14.

A stepping motor 16 is fixed to the first lens barrel 6 with a screw 44 and meshes with the gear 14. This is because when the output gear 16a rotates, the gear 15, the gear 14 and the gear 7b rotate, the feed screw portion 7a rotates, and the second lens rack 9 moves in the optical axis direction by the second lens rack 10. Is configured to do.
Reference numeral 17 denotes a third lens barrel that holds the third lens group 3 and is attached to the fixed barrel 5. Reference numerals 18 and 19 denote screws that fix the third lens barrel 17 to the fixed barrel 5.

Reference numeral 20 denotes a light amount adjusting device attached to the third lens barrel 17, and 21 denotes a screw for attaching the light amount adjusting device 20 to the third lens barrel 17.
22 holds the fourth lens group 4, the sleeve portion 22 a is fitted to the bar 8, is held so as to be rotatable and movable in the optical axis direction, and the U-groove portion 22 b is fitted to the bar 7 to restrict rotation. This is a fourth lens barrel.
Reference numeral 23 denotes a fourth lens rack for driving the fourth lens barrel 22 in the optical axis direction. The fourth lens rack 23 is rotatably held by rack holding portions 22c and 22d of the fourth lens barrel 22.

Reference numeral 24 denotes a rack spring hung on the fourth lens rack 23. The fourth lens rack 23 is shifted to the fourth lens barrel 22, and the engagement portion with the feed screw 8a of the fourth lens rack 23 is sandwiched between the back and forth. Engage without any problems.
A photo reflector 25 is fixed to the fourth lens barrel 22 and detects the position of the fourth lens barrel 22.
26 is a gear holding member fixed to the fixed barrel 5, 27 is pinched and held between the fixed barrel 5 and the gear holding member 26, and a gear is engaged with the gear 8b of the bar 8, and 28 is a gear holding member with the fixed barrel 5. The gear is held between the members 26 and meshes with the gear 27.

Reference numeral 29 denotes a stepping motor which is fixed to the fixed barrel 5 with a screw 30 and meshes with the gear 28. As the output gear 29a rotates, the gear 28, the gear 27, and the gear 8a rotate, the feed screw portion 8a rotates, and the fourth lens barrel 22 moves the fourth lens barrel 22 in the optical axis direction. Is configured to do.
Reference numeral 31 denotes a low-pass filter fixed to the fixed barrel 5, and 32 denotes an image pickup element fixed to the fixed barrel 5.

FIG. 4 shows an electrical configuration of the camera body in the imaging apparatus configured using the lens barrel of the present embodiment. In this figure, the same reference numerals as those in FIGS. 1, 2, and 3 are assigned to the components of the lens barrel described in FIGS.
In FIG. 4, reference numeral 33 denotes a drive source for the second lens group 2 and includes a stepping motor 16, a gear 14, a gear 15, a second lens rack 10, a rack spring 11, and the like.
Reference numeral 34 denotes a drive source for the fourth lens group 4, which includes a stepping motor 29, a gear 27, a gear 28, a fourth lens rack 23, a rack spring 24, and the like.
Reference numeral 35 denotes a drive source for the light amount adjusting device 20 disposed between the second lens group 2 and the third lens group 3.

Each of the photo reflectors 12 and 25 detects the absolute position of the second lens group 2 and the fourth lens group 4 in the optical axis direction, arranges the holding frame at the reference position, and then determines the number of operation pulses input to the stepping motor. By continuously counting, movement and position detection of the second lens group 2 and the fourth lens group 4 in the optical axis direction are performed.
Reference numeral 36 denotes a light amount adjustment device encoder, which employs a system in which a Hall element is disposed inside a light amount adjustment drive source 35 such as a motor and detects the rotational positional relationship between the rotor and the stator.

A CPU 37 controls the camera. A camera signal processing circuit 38 performs predetermined amplification, gamma correction, and the like on the output of the image sensor 32. The contrast signal of the video signal subjected to these predetermined processes passes through the AE gate 39 and the AF gate 40. That is, an optimum signal extraction range for exposure determination and focusing is set in this gate in the entire screen. The size of the gate may be variable or a plurality of gates may be provided.
Reference numeral 41 denotes an AF signal processing circuit that processes an AF signal for AF (autofocus), and generates one or a plurality of outputs related to high-frequency components of the video signal. Reference numeral 42 is a zoom switch, and 43 is a zoom tracking memory. The zoom tracking memory 43 stores information on the focusing lens position to be set according to the subject distance and the variator lens position at the time of zooming. Note that the memory in the CPU 37 may be used as the zoom tracking memory.

  For example, when the photographer operates the zoom switch 42, the CPU 37 maintains a predetermined positional relationship between the second lens group 2 and the fourth lens group 4 calculated based on information in the zoom tracking memory 43. In addition, the count value, which is the absolute position of the second lens group 2 in the optical axis direction, the calculated position where the second lens group should be set, and the absolute position of the fourth lens group 4 in the optical axis direction. The second lens group drive source 33 and the fourth lens group drive source 34 are driven and controlled so that a certain counted value and the calculated position where the focus lens is to be set coincide with each other.

In the autofocus operation, the CPU 37 drives and controls the fourth lens group drive source 34 so that the output of the AF signal processing circuit 41 shows a peak.
Further, in order to obtain proper exposure, the CPU 37 sets the average value of the output of the Y signal that has passed through the AE gate 39 as a predetermined value, and the light amount adjusting device drive source so that the output of the light amount adjusting device encoder 36 becomes this predetermined value. 35 is driven and controlled to control the amount of light.

  In the configuration of this embodiment, the stepping motor 16 for driving the second lens group 2 fixed to the first lens barrel 6 has a feed screw portion 7a that is rotated by the rotation of the gear 14 and the gear 15, and the stepping motor The drive unit is configured to be shorter than the extension of 16. Further, the stepping motor 29 for driving the fourth lens group 4 fixed to the fixed barrel 5 is not provided with a feed screw portion 8a that is rotated by the rotation of the gear 27 and the gear 28 and is not on the extension of the stepping motor 29. Is structured short. These two lens driving units are arranged so as to overlap in the optical axis direction. As a result, the cross-sectional area viewed from the lens optical axis direction is reduced, so that the respective driving units do not interfere with each other. Therefore, the driving unit is arranged on the inner diameter side of the lens, that is, the second lens group 2 which is a driven optical element. In the vicinity of the third lens group 3, the first lens group 1 and a part of the drive unit can be arranged so as to overlap each other when viewed from the optical axis direction, and the lens barrel can be downsized.

  In addition, by reducing the speed at the gear connecting portion, even if the output torque is small with a small stepping motor, the torque of the feed screw portion necessary for driving the lens can be obtained. The cylinder can be downsized. In particular, in this embodiment, not only the lens driving unit but also the driving unit of the light amount adjusting device 20 is arranged at a position overlapping the lens driving unit as viewed from the lens optical axis. This reduces the cross-sectional area of the lens driving unit and the driving unit of the light amount adjusting device 20 as viewed from the lens optical axis direction, so that the respective driving units do not interfere with each other. Can be placed on the side. Since the driving unit can be disposed on the inner diameter side, the lens barrel can be reduced in size. In addition, by configuring an optical device using such a lens barrel, the optical device can be downsized as a whole.

[Example 2]
In the second embodiment of the present invention, a lens barrel is configured by applying the above-described configuration of the present invention. In this embodiment, when applying the configuration of the present invention, at least two of the plurality of driving units are arranged at a distance closer to the optical axis than the radius of the optical element; can do. Further, at least two of the plurality of driving units may be arranged at a position farther from the subject than the plurality of optical elements.

Next, these specific configurations will be described with reference to the drawings.
Here, FIG. 5 is a sectional view of the present embodiment, FIG. 6 is a side view of the present embodiment, and FIG. 7 is an exploded perspective view for explaining the present embodiment. In these figures, the driving unit of the light amount adjusting device attached to the third lens barrel, the stepping motor fixed to the fixed barrel, and another stepping motor fixed to the fixed barrel are respectively shown in the optical axis direction. A configuration example of this embodiment is shown in which the lens barrel is arranged so as to overlap with the lens barrel so as to reduce the size of the lens barrel.

  In these figures, 101 is the first lens group closest to the object side, 102 is a second lens group that moves in the optical axis direction during zooming, 103 is a third lens group, and 104 is during zooming and focus adjustment. It is the 4th lens group which moves to an optical axis direction. Reference numeral 105 denotes a fixed barrel fixed to a camera body (not shown), 106 denotes a first lens barrel that holds the first lens group 101 and is coupled by screws 151 and 152 of the fixed barrel 105, and 107 fixes both ends. A bar 108 is held between the lens barrel 105 and the first lens barrel 106, and 108 is a bar which is held between both ends of the fixed lens barrel 105 and the first lens barrel 106.

109 holds the second lens group 102, the sleeve portion 109a is fitted to the bar 107, is held so as to be rotatable and movable in the optical axis direction, and the U-groove portion 109b is fitted to the bar 108 to restrict rotation. The second lens barrel 110 is a second lens rack for driving the second lens barrel 109 in the direction of the optical axis, and is rotatably held by the rack retaining portions 109c and 109d of the second lens barrel 109. Has been. Reference numeral 111 denotes a rack spring hung on the second lens rack 110, and the second lens rack 110 is shifted to the second lens barrel 109.
A photo interrupter 112 detects the position of the second lens barrel 109.

113 is a stepping motor, 114 is a stepping motor holding member to which the stepping motor 113 is attached, and is attached to the fixed barrel 105 by screws 115.
A feed screw 116 meshes with the second lens rack 110 that is biased so as to be sandwiched by the rack spring 111. The feed screw 116 has a gear 116a that meshes with the output gear 113a of the stepping motor 113, and the output gear 113a of the stepping motor 113 rotates. The feed screw 116 is rotated by the gear 116a, and the second lens barrel 109 is moved in the optical axis direction by the second lens rack 110.

Reference numeral 117 denotes a third lens barrel that holds the third lens group 103 and is attached to the fixed barrel 105, 118 denotes a light amount adjustment device attached to the third lens barrel 117, and 119 and 120 denote light amount adjustment devices 118. A screw attached to the third lens barrel 117.
122 holds the fourth lens group 104, the sleeve portion 122 a is fitted to the bar 108, is held so as to be rotatable and movable in the optical axis direction, and the U groove portion 122 b is fitted to the bar 107 to be restricted in rotation. The fourth lens barrel 123, which is a fourth lens rack for driving the fourth lens barrel 122 in the optical axis direction, is rotatably held by a rack retaining portion of the fourth lens barrel 122.
A rack spring 124 is hung on the fourth lens rack 123, and the fourth lens rack 123 is shifted to the fourth lens barrel 122.
A photo interrupter 125 is fixed to the fourth lens barrel 122 and detects the position of the fourth lens barrel 122.

A stepping motor 126 and a stepping motor holding member 127 to which the stepping motor 126 is attached are attached to the fixed barrel 105 by screws 128.
129 is a feed screw that meshes with the fourth lens rack 123 that is biased so as to be sandwiched by the rack spring 124, and has a gear (not shown) that meshes with the output gear 126a of the stepping motor 126, and the output gear 126a of the stepping motor 126 rotates. As a result, the feed screw 129 is rotated by the gear meshed with the output gear 126 a, and the fourth lens barrel 122 is moved in the optical axis direction by the fourth lens rack 123. Reference numeral 130 denotes a holding member that fixes the photo interrupter 112 and the photo interrupter 125 and is attached to the fixed barrel. Reference numeral 131 denotes a low-pass filter fixed to the fixed barrel 105, and 132 denotes an image sensor fixed to the fixed barrel 105.
The electrical configuration of the camera body in the imaging apparatus according to the second embodiment of the present invention is the same as that of the first embodiment except that the photo reflector is changed to a photo interrupter.

  In Embodiment 2 of the present invention, the stepping motor 113 attached to the fixed barrel 105 and the stepping motor 126 attached to the fixed barrel 105 are arranged so as to overlap in the optical axis direction. As a result, the cross-sectional area viewed from the lens optical axis direction is reduced, so that each drive unit does not interfere with each other, so that the drive unit is located on the lens inner diameter side, that is, near the extension line of the optical axis, from the optical axis direction. As a result, it can be arranged at a position overlapping each lens group, and the lens barrel can be downsized. Thereby, a lens barrel can be reduced in size. By configuring the optical apparatus using such a lens barrel, the optical apparatus can be reduced in size as a whole.

  According to the configurations of the first and second embodiments of the present invention described above, the driving unit occupies the cross section viewed from the optical axis direction by disposing the lens driving unit so as to overlap in the optical axis direction. Since the portion is reduced and the drive unit can be arranged on the inner diameter side of the lens, the lens barrel can be reduced in size. In addition, an optical device using the lens barrel can be reduced in size. In addition, those in these embodiments can be suitably used for lens barrels or optical devices such as 35 mm film photographic cameras, digital still cameras, and video cameras.

1 is a cross-sectional view illustrating a configuration of a lens barrel in Embodiment 1 of the present invention. The perspective view seen from the optical axis direction diagonally upward of the lens barrel in Example 1 of the present invention. The perspective view disassembled for description of the lens barrel in Embodiment 1 of the present invention. 1 is a diagram illustrating an electrical configuration of a camera body in an imaging apparatus to which a lens barrel in Embodiment 1 of the present invention is applied. Sectional drawing which shows the structure of the lens barrel in Example 2 of this invention. FIG. 6 is a side view showing a configuration of a lens barrel in Embodiment 2 of the present invention. The perspective view disassembled for description of the lens barrel in Embodiment 2 of the present invention. It is a figure which shows the structure of the lens barrel of a prior art example, (a) is the front view seen from the object side of an objective lens, (b) The rear view of a lens barrel, (c) is a side view of a lens barrel, d) is a cross-sectional view seen from the image side.

Explanation of symbols

1: First lens group 2: Second lens group 3: Third lens group 4: Fourth lens group 5: Fixed barrel 5a: Bayonet 6: First lens barrel 6a: Bayonet 7: Bar 7a: Feed screw portion 7b: Gear portion 8: Bar 8a: Feed screw portion 8b: Gear portion 9: Second lens barrel 9a: Sleeve portion 9b: U groove portion 9c: Rack retaining portion 9d: Rack retaining portion 10: Second lens rack 11: Rack spring 12: Photo reflector
13: Gear holding member 14: Gear 15: Gear 16: Stepping motor 16a: Output gear 17: Third lens barrel 18, 19: Screw 20: Light quantity adjusting device 21: Screw 22: Fourth lens barrel 22a: Sleeve portion 22b: U-groove portions 22c, 22d: rack fastening portion 23: fourth lens rack 24: rack spring 25: photo reflector
26: Gear holding member 27: Gear 28: Gear 29: Stepping motor 29a: Output gear 30: Screw 31: Low-pass filter 32: Image sensor

Claims (7)

A plurality of optical elements, and a plurality of drive units for driving the plurality of optical elements in the optical axis direction,
A lens barrel, wherein at least two of the plurality of driving units are arranged on a straight line substantially parallel to the optical axis direction.   The lens barrel according to claim 1, wherein at least two of the plurality of driving units are a focus lens driving unit and a zoom lens driving unit.   The at least two drive units among the plurality of drive units are arranged at a distance closer to the optical axis than a radius of a lens included in the lens barrel. Lens barrel.   The lens barrel according to claim 1, wherein at least two of the plurality of driving units are arranged at a distance closer to the optical axis than a radius of the optical element.   The at least two drive units among the plurality of drive units are arranged at positions farther from the subject than the plurality of optical elements. Lens barrel. Focus lens, focus lens drive unit for driving the focus lens in the optical axis direction, zoom lens, zoom lens drive unit for driving the zoom lens in the optical axis direction, iris, and for light quantity adjustment Having an iris drive unit for driving the eyeless,
The lens barrel, wherein the focus lens driving unit, the zoom lens driving unit, and the iris driving unit are arranged on a straight line substantially parallel to the optical axis direction.   An optical apparatus comprising the lens barrel according to claim 1 and a camera body.

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