JP3413686B2 - Lens barrel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] BACKGROUND OF THE INVENTIONSupports movable lens structure
Provided with a shaft support mechanism for supporting shafts such as guide shafts
Used for camerasIt relates to a lens barrel. [0002] 2. Description of the Related Art For example, video cameras have
Auto focus mechanism that automatically performs focusing
Also, an electric zoom mechanism for changing the magnification is provided.
These auto focus mechanism and electric zoom mechanism
Is moved in the optical axis direction by the driving means inside the
For lens barrel with focus lens and zoom lens
Is achieved. The lens barrel is supported inside the barrel in the optical axis direction.
Lens that are movably mounted on the held guide shafts
The focus lens and zoom lens
To form a movable lens structure.
The moving means is moved along the guide axis. Zoo
The driving means of the lens assembly is the lens system of the video camera.
Determine the Wide end and the Tele end to determine the zoom lens structure.
Is moved with a large moving amount into the lens barrel. did
Therefore, the driving means of the zoom lens structure is generally
This stepping motor is driven by a stepping motor.
-Linear motion converter that converts the rotational motion of the motor into linear motion
It consists of a zoom lens drive unit with
You. On the other hand, driving means for the focus lens structure
Is a CCD solid-state imager with the subject image arranged at the rear end of the lens barrel
Focus lens structure to form an image on the imaging surface of the device
Is moved along the optical axis direction with good responsiveness. others
Therefore, the driving means of the focus lens
It is constituted by an Amota. Linear motor
Physically, it is integrated with the focus lens structure
Coil frame, the yoke arranged on the lens barrel side, and this yaw
With magnets attached to each yoke piece
It is composed of [0005] The linear motor uses a control output from a control unit.
Therefore, when a drive current is supplied to the coil of the coil frame,
Between the coil and yoke corresponding to the direction of the drive current
Produce a bundle. In addition, this magnetic flux
A magnet that moves the structure along the guide axis in the optical axis direction
To generate dynamic propulsion. Therefore, the focus lens
With this magnetic propulsion, the structure moves along the optical axis in the lens barrel.
The object is moved on the imaging surface of the CCD solid-state imaging device
Form an image. The above-described guide shaft is fixed to the lens barrel.
Guide bearings are provided in various places to support
I have. This guide bearing is provided as shown in FIGS.
Of the guide shaft has a hole diameter approximately equal to the outer diameter of the guide shaft.
An id shaft hole 102 is provided. This guide shaft hole 10
2 is a hollow portion 104 in which a guide shaft is fitted and supported.
It is formed in a columnar shape substantially equal to the shape of the shaft. Further, the guide bearing portion 101 is provided with a guide
The diameter of the opening on the opening side of the shaft hole 102 is increased.
Surface funnel-shaped taper 103 is provided, and guide shaft is inserted
Only make it easier. Further, the guide bearing portion 101
When inserting the guide shaft, the bottom of the guide shaft hole 102
The air filled in the hollow space between the guide shaft and the tip
The through hole 105 to be exhausted is located at the bottom of the guide shaft hole 102.
It is provided in the center. In the guide shaft hole 102, the guide shaft is tapered.
It is inserted as it is in a state where it is hit on 103. Guy
When the guide shaft is inserted into the
Empty space 104 between the bottom surface and the tip surface of the guide shaft
Qi is filled. This air is compressed by the guide shaft
Through the through hole 105 and outside the guide bearing portion 101.
Exhausted to As a result, the guide bearing portion 101
When the guide shaft reaches the bottom of the guide shaft hole 102, the guide
Support the shaft. [0009] By the way, a lens barrel
Is a focus lens that is moved at a relatively high speed as described above.
For example, to ensure the sliding property of the
Lubricant with relatively low viscosity such as oil
It has been applied. Therefore, the guide shaft hole 102
The guide shaft with the lubricant attached to the tip surface of the guide shaft
Is inserted, and the lubricant closes the through hole 105 in the bottom part.
May be attached. Therefore, the guide shaft hole 102
When the guide shaft is inserted, the internal air is
Is not exhausted from the through hole to the outside of the guide bearing portion 101
It becomes such a state. Therefore, the conventional lens barrel
In this case, the guide shaft hole 102 of the guide bearing portion 101 is
The problem that the id axis cannot be easily inserted
was there. The guide shaft hole 102 is inserted
The lubricant applied to the guide shaft
Gradually accumulates between the bottom surface and the tip surface of the guide shaft
You. This lubricant passes through the through-hole 105 and passes through the guide bearing.
Leakage from the part 101 to the inside of the lens barrel, causing the lens to become dirty
There is a risk. In addition, leakage from the through-hole 105 into the lens barrel
Lubricating oil has high viscosity.
The zoom lens assembly to the stopper
It is said that the joint state will cause malfunction of the zoom lens structure
There was a problem. Further, the conventional lens barrel is provided with a guide bearing.
Center part of the bottom part of the guide shaft hole 102 constituting the part 101
Since the through hole 105 must be provided separately,
There was also a problem that the man-hour increased and it was troublesome. [0013]The present inventionGuide shaft against guide shaft hole
Easy insertion and reduced assembly time
To improve the work efficiency and guide the lubricant.
Movable lens by preventing outflow of bearings
To provide a lens barrel with improved accuracy of the structure
It has been proposed for the purpose. [0014] The above object has been achieved.
The lens barrel according to the present invention has an inner wall in the optical axis direction.guideaxis
A lens barrel integrally formed with a guide bearing portion having a hole,
The end is the guide shaft holeUp to the bottomPlugged and supported
With lubricant appliedCircular cross sectionGuide shaft and
Supported by the guide shaft of
And a movable lens structure that is moved in the direction. Soshi
Guide shaftThe hole is formed when the hollow part is provided in a polygonal shape.
A shaft hole that does not have a through hole in the bottom
Support the outer peripheral surface of the shaft with the inner surface of the guide shaft hole. [0015] According to the lens barrel of the present invention, a guide bearing is provided.
Lubricate the guide shaft hole that constitutes the part and the tip surface of the guide shaft
With the agent attached, the guide shaftTo the bottomPlugged in
You. When the guide shaft is inserted into the guide shaft hole,
Air between the outer peripheral surface and the guide shaft holeInside surfaceIs composed between
Exhaust from the opening side of the guide shaft hole through the gap
By this, it is very easily inserted and supported. On the guide shaft,Movable lens structureThe sliding property of
Lubricant is applied to secure. This lubricant
By inserting the guide shaft into the guide shaft hole,
Collects in this guide shaft hole but does not leak outside
Therefore, the lens and the like are not stained. [0017] BRIEF DESCRIPTION OF THE DRAWINGS FIG.
This will be described in detail with reference to planes. The embodiment is a video camera
Automatic focusing on the subject
Auto focus lens mechanism and electric zoom to change magnification
1 shows a lens barrel 1 having a camera mechanism. The lens barrel 1 is
As shown in FIG. 1, a front lens barrel 3 formed in a cylindrical shape and a corner are formed.
It is configured by combining with a rear barrel 4 formed in a tubular shape.
The lens barrel 2 is provided. The lens barrel 1 is provided as shown in FIGS.
Inside the lens barrel 2 from the front side of the lens barrel 1 to the optical axis.
Along the zoom unit 5 and the iris unit 6
And an intermediate frame 7 and a focus unit 8
Has been established. In the following description, “forward”
Indicates the left side in FIG. 1, and "rear" indicates the right side.
Shall be shown. The front barrel 3 is slightly larger than the rear barrel 4.
It has a large opening diameter. The front lens barrel 3 has an open rear surface.
It is released and on the front surface facing this opening
A first fixed lens holder 3A is provided. this
The first fixed lens holder portion 3A has a
A first fixed lens mounting hole 3B is provided.
First fixed lens group 9 is fixed to lens mounting hole 3B.
I have. The “fixed lens group” refers to the light
Only one piece incorporated in the lens barrel without being moved in the axial direction
Or a plurality of lens groups. Also, the front lens barrel 3
Inside this, the opposite corners of the front surface
A guide shaft hole 3C is provided. The zoom unit 5 includes a zoom guide shaft.1
0A, 10BAnd these zoom guide axes10A, 10
BThat can be moved in the optical axis direction by being supported through
The zoom lens is positioned on the upper surface of the lens barrel 11 and the front lens barrel 3.
Zoom lens (not shown) for driving the lens assembly 11
Lens drive mechanism and the lower part of this zoom lens drive mechanism.
Guide shaft 10 for zoomBZoom lens located near
A first position detection sensor 12 for detecting the position of the structure 11;
It is composed of Guide shaft for zoom10A, 10BAre each other
Having a length dimension equal to
11 is long enough to secure the amount of movement
You. Also, a guide shaft for zoom10A, 10BThere is a guri
A relatively high-viscosity lubricant such as wool is applied. The zoom lens structure 11 is a zoom lens group.
13 and a zoom lens holding the zoom lens group 13
Lens holder 14 and a video camera lens system.
Are determined at the Wide end and the Tele end. In addition, "movable
`` Lens group '' refers to the movement of the lens barrel in the optical axis direction during shooting.
One or a plurality of lens groups that are moved. Z
Lens group 13 functions as a so-called zoom lens
In combination with the first fixed lens group 9, the angle of view can be adjusted.
Do. The outer shape of the zoom lens holder 14 is a disk shape.
The outer diameter is larger than the inner diameter of the front lens barrel 3.
It is small. The zoom lens holder 14 is located between
A zoom lens mounting hole 14A is provided in the area, and this zoom
The zoom lens group 13 is fixed to the lens mounting hole 14A.
ing. The zoom lens holder 14 is located on this side.
Guide axis for zoom located on the surface10A, 10B
Guide shaft having a spacing dimension equal to the distance between two axes
Receiving parts 14B and 14C are provided facing each other. Zoo
Guide bearings 14B and 14C are 180 ° apart from each other.
The guide shaft for zooming10
A, 10BAre respectively penetrated in the optical axis direction. Zoom
The guide holder 14 for zoom is provided on the side of the lens holder 14.
A position detecting piece 14D having a semicircular cross section is formed along B.
I have. A zoom lens driving mechanism (not shown) is driven
Motor and attached to one side of this drive motor
It is composed of a rotation-linear motion conversion mechanism. The drive motor is
Illustration connected to a power supply that supplies drive current to the other side
Not the first flexible printed cable is connected
ing. This drive motor rotates when supplied with a drive current.
Driven. In addition, as the drive motor, stepping
A motor is used. The rotation-linear motion conversion mechanism is
The driver engaged with the lens assembly 11 has a thread groove on the outer periphery.
Is screwed into the rotating shaft. Rotation-linear motion conversion
The mechanism is such that when the rotation axis is rotated, the driver
Is moved. The first position detecting sensor 12 has a first frame.
A kibble print cable is attached to the front barrel 3
In the zoom lens holder 14
Light-receiving element and light-emission across the moving area of the position detection piece 14D
It is constituted by an optical detection sensor comprising an element. The iris unit 6 is provided as shown in FIG.
First, a disc-shaped base 15A and one side face of the base 15A
A base member comprising a motor mounting portion 15B protruding from the body
15 and the drive mounted on the motor mounting portion 15B.
And a motor 16. Base of base member 15
A stop hole 15A whose optical axis coincides with each lens group is provided in 15A.
C is formed at the center. The base 15A is
Finely, it is composed of two thin disks stacked on top of each other.
In addition, a plurality of diaphragm blades are incorporated inside. The iris unit 6 has an output from the control unit.
The drive motor 16 is driven by the
The blade is driven to adjust the opening size of the aperture 15C.
You. The lens barrel 1 is used for the operation of the iris unit 6.
Therefore, the light amount is adjusted. The iris unit
For 6, for example, using an electrochromic element
Of course, it may be constituted by an iris unit or the like.
It is a theory. The intermediate frame 7 includes a second fixed lens group 17 and
A second fixed lens holding the second fixed lens group 17
And a holder 18. Second fixed lens
The holder 18 is formed in a substantially rectangular shape, and its outer dimensions are
The outer diameter of the lens barrel 4 is substantially equal to the outer diameter. Second
The fixed lens holder 18 has a second fixed lens
And a second fixed lens mounting hole 1A.
The second fixed lens group 17 is fixed to 8A. Ma
In addition, the second fixed lens holder 18 has a rear surface portion.corner
Department, A zoom guide shaft hole 18B is formed. The second fixed lens holder 18 has a rear surface
Opposing partsCornerAnd focus guide shaft hole 1
8C is provided. This focus guide shaft hole 1
8C is a diagonal length as shown in FIGS.
Is a guide axis for focusing, which will be described later.20A, 20BofShaft diameter
Constructed as a slightly larger octagonal shaft hole
Is, There is no through hole in the bottom part as before.
I. The focus guide shaft hole 18C has an opening.
Nozzle with a funnel-shaped section with a large hole diameter on the opening side
An insertion taper 18a is provided. The rear lens barrel 4 has an open front surface.
The CCD solid-state imaging
An image element 19 is provided. Also, the rear barrel 4 is
Opposite sides of the inner surfaceCornerNext, focus gas
An id shaft hole 4A is provided. The rear barrel 4 is at the bottom
A second position detection sensor mounting opening (not shown)
Is provided. The rear barrel 4 is provided with a
The guide shaft hole 4B for zoom is provided on the side of the
I have. The rear barrel 4 is a zoom guide on the front surface.
A substantially U-shaped casing is formed on the bottom side facing the shaft hole 4B.
Cable drawer is provided. The focus unit 8 includes a focusing gear.
Id axis20A, 20BOr housed or fixed in the rear barrel 4
Consists of specified componentsFocus not shown
Slens drive mechanismAnd focus guide axis20A, 2
0BFocused on the optical axis and movable in the optical axis direction
The lens structure 22 and the second position detection sensor of the rear barrel 4
A second position detection cell (not shown) attached to the
And a sensor. Guide axis for focusing20A, 20BIs
The cross section is circular,Check the amount of movement of the focus lens
It has a length dimension sufficient to maintain. Also, focus
Guide shaft20A, 20BMoving at relatively high speed
Ensuring slidability of the focus lens structure 22 to be manufactured
Therefore, lubrication with a relatively low viscosity, such as fluorine-based oil
The agent is evenly applied to the entire guide shaft 20 for focusing.
ing. The focus lens driving mechanism isNot shown
But,MetalFirst yokeas well asThe second yokeAnd these
Fixed to two yokes respectivelymagnetAnd from
Has been established. The focus lens structure 22 is used for focusing.
Holding the lens group 26 and the focus lens group 26
Focus lens holder 27 and this focus lens
A coil bobbin 28 formed integrally with the holder 27;
The coil wound around the coil bobbin 28 and the coil
The second flexible printed cable to which both ends of the
And a bull. Focus lens group 26
Functions as a focus lens and a second fixed lens
Focus adjustment is performed in combination with the group 17. The outer shape of the focus lens holder 27 is rectangular.
The outer dimensions are the inner dimensions of the rear barrel 4
It is smaller. The focus lens holder 27 is
A focus lens mounting hole 27A is provided in this intermediate area.
Focus lens mounting hole 27A.
The lens group 26 is fixed. The focus lens holder 27 is
Positioned on the side of the lubobin 28, the distance
Id axis20A, 20BDistance dimension equal to the distance between axes with
Focus guide bearings 27C and 27D
It is provided facing. Focus Guide Bearing 27
C and 27D are formed at positions 180 ° opposite to each other.
Guide axis for focus20A, 20BEach
Is penetrated. Further, the focus lens holder 27
The focus lens structure 22 is built into the rear barrel 4
A second position (not shown) provided on the rear barrel 4 in the retracted state
Magnet holder at a position facing the position detection sensor
The magnet holder for position detection is
Is installed. The second flexible printed cable is
One end is connected to the terminal connection portion 31 of the focus lens structure 22.
A connecting plate is attached, and both ends of the coil are soldered to this connecting plate.
Is attached. Second flexible printed cable
Is supported through the leading end of the focusing guide shaft 20.
And a support hole for the rear barrel 4
A support portion supported by the cable drawer is provided. No.
The other end of the flexible printed cable is not shown.
Power supply is connected. A second position detection sensor (not shown) is
Second position detection provided in the central region of the bottom surface of the lens barrel 4
It is attached to the sensor attachment port. Second position detection sensor
Is the focus lens holder of the focus lens structure 22.
Magnetic flux generated by the position detection magnet attached to the
The resistance value changes due to the change in density.
To adjust the position of the focus lens structure 22 in the optical axis direction.
To detect. Example lens barrel constructed as described above
The method 1 is described below. The lens barrel 1 is
The focusing guide shaft hole 4A of the rear lens barrel 4
Guide shafts 20 are inserted into cantilever condition
Supported. Also, there is a focus inside the rear barrel 4
First yoke and second yoke of lens drive mechanism 21
But the guide axis for focus20A, 20BParallel and relative
Screwed to the rear surface inside the rear barrel 4
Is Guide axis for focusing20A, 20BTo
Is a focus guide shaft of the focus lens structure 22
By receiving parts 27C and 27D being respectively penetrated,
The focus lens structure 22 can be moved in the optical axis direction.
Is supported. At this time, the focus lens structure 22
Is a focus lens drive fixed inside the rear barrel 4.
Combined with the first yoke and the second yoke of the moving mechanism 21
Is done. Guide axis for focus20A, 20BIs
With the lubricant attached to the tip surface, apply
Guide shaft hole for focusing provided on the rear surface of the frame 7
It is easily applied as it is against the taper 18a of 18C.
Be included. A focus guide shaft hole 18C
Guide shaft for waste20A, 20BButTo the bottomPlugged in
The bottom of the focus guide shaft hole 18C
Guide shaft for carcass20A, 20BBetween the front end of the
The space is filled with air. This air is used for focusing gas.
Id axis20A, 20BCompressed by focus for
Guide shaft20A, 20BofOuter surfaceAnd focus guide
It passes through the gap formed between the inner surface of the shaft hole 18C and the forehead.
The gas is exhausted from the opening side of the focus guide shaft hole 18C. Further, the focus guide shaft hole 18C is
Guide axis for focusing20A, 20BIs inserted
And focus guide axis20A, 20BOn the tip surface of
The attached lubricant is used for the focusing guide shaft hole 18C.
Bottom part and focus guide axis20A, 20BTip face of
Between the parts. This lubricant is
Id axis20A, 20BCompressed by focus for
Inner surface of guide shaft hole 18C and guide shaft 20 for focus
ofOuter surfaceIs filled in the gap generated between. focus
Guide shaft hole 18C until it reaches this bottom.
The focus guide shaft 20 is inserted. By this
hand,The focus guide shaft hole 18C is located on the bottomFour
Guide shaft for waste20A, 20BHas reached focus
Guide shaft20A, 20BI support. The intermediate frame 7 is an inner edge of the front surface of the rear barrel 4.
The side part is fitted into the part. The intermediate frame 7 is
Base 15A of base member 15 constituting iris unit 6
Is fitted. At this time, the iris unit 6
A dynamic motor 16 is located above the rear barrel 4 and
The motor mounting portion 15B of the member 15 is located on the front surface of the rear lens barrel 4.
Screwed to the outer edge. The rear barrel 4 is provided with a zoom guide shaft hole.
4B, zoom guide shaft10A, 10BAre different
It is inserted and supported in a cantilevered state. Guide axis for zoom
10A, 10BFor zooming the zoom lens structure 11
Guide bearing portions 14B and 14C are respectively penetrated.
Allows the zoom lens structure to move in the optical axis direction
11 are supported. Guide shaft for zoom10A, 10BIs the tip
Guide provided on the front surface of the front lens barrel 3
The shaft hole 3C is fitted. At this time, the front lens barrel 3 is
Screwed to the inner edge of the opening on the front side of the lens barrel 4
You. Finally, the front barrel 3 and the rear barrel 4 are shown in the upper part.
Not shown zoom lens drive mechanism will be screwed
Therefore, the lens barrel 1 is assembled. The lens barrel 1 assembled as described above
The zoom unit 5 is provided with a zoom lens from a power source (not shown).
Drive current is supplied to the drive motor that constitutes the
Then, the drive motor is driven to rotate. This drive motor
Constitutes a zoom lens drive mechanism when rotated.
The rotation axis of the rotation-linear motion conversion mechanism is rotated. rotation
When the shaft is rotated, the drive mounted on the rotating shaft
The child is moved in the optical axis direction. The driver is a zoom lens
In the optical axis direction while engaged with the
You. Therefore, the zoom lens structure 11 is
As shown by an arrow M in FIG.
What is the guide axis for zoom10A, 10BSupported by light
It moves in the axial direction. This allows the zoom lens
The zoom lens group 13 constituting the body 11 is attached to the front barrel 3.
The distance between the first fixed lens group 9 and the first fixed lens group 9 is adjusted.
And zoom control is performed. Further, the zoom lens structure 11 includes a front lens barrel.
When the position detecting piece 14D is moved in the center of
Between the light receiving element and the light emitting element of the first position detection sensor 12
Pass through. The first position detection sensor 12 includes these elements
The detection output is controlled by detecting that the interruption state between
To the department. The stepping motor detects this position.
The rotation operation is controlled by the output of the sensor 12. Therefore, the focus lens structure 22
The figure1As indicated by an arrow N inside, between the coil and the closed magnetic circuit.
Thrust depending on the direction of the supplied drive current
By the guide axis for focus20A, 20BSupported by
Then, it moves in the optical axis direction. At this time, focus
The lens structure 22 has a focus guide shaft.20A, 20
BLubricity applied to the surface ensures slidability
To move. This allows the focus lens structure
The focusing lens group 26 constituting the rear lens barrel 4
Distance from the CCD solid-state imaging device 19
Is adjusted and focus control is performed.
The image passing through the focus lens group 26 on the image sensor 19
An image is taken. The focus lens structure 22 is
Guide shaft for carcass20A, 20BAxially supported by
With the movement operation, the focus lens holder 27
The attached position detection magnet is the second
Position detection attached to the position detection sensor mounting opening
By being opposed to the sensor, this second position detection is performed.
The magnetic flux density exerted on the output sensor is changed. Second location check
The output sensor changes its resistance value due to this change in magnetic flux density.
The amount of change is counted and the focus lens
2 is detected in the optical axis direction. Therefore, in the focus unit 8,
Based on the detected position of the focus lens structure 22
Power required for the coil of the focus lens drive mechanism
Controls the movement of the focus lens structure 22 when it is turned on
The focus lens holder 27
Focus control of the focus lens group 26 is performed. In the lens barrel 1 of the embodiment described above,
Focusing Guy Supporting Focus Lens Structure 22
Axis20A, 20BOf oil such as fluorinated oil
With a relatively low lubricant evenly applied,
The slidability of the focus lens structure 22 is ensured,
To move the cas lens structure 22 at a relatively high speed
Can be. In the lens barrel 1, an intermediate frame 7 is formed.
Guide for focusing on the second fixed lens holder 18
A shaft hole 18C is provided.
8C hollow portion 18b is provided in a regular octagonal cross section
Thereby, the bottom surface of the focusing guide shaft hole 18C is
Guide axis for focus20A, 20BBetween the front end of the
The air filled in the hollow portion 18b of the air becomes easy to be exhausted.
Guide for the focus of the second fixed lens holder 18
Easy insertion of focus guide shaft 20 into shaft hole 18C
Can be taken. Further, the lens barrel 1 is provided with a focusing lens.
The hollow portion 18b of the id shaft hole 18C is provided in a regular octagonal cross section.
The guide shaft hole 18C for focusing.
Bottom part and focus guide axis20A, 20BBetween
The lubricant filled by the20A,
20BGuide shaft hole 18
Between the inner surface of C and the guide shaft 20 for focusing.Outer surfaceBetween
The second fixed level of the lubricant is
The lens holder 18 is prevented from flowing out. Further, the lens barrel 1 is
Hollow portion 18b of the guide shaft hole 18C has a regular octagonal cross section.
By being provided, the focus guide shaft hole 1 is provided.
There is no need to provide a separate through hole in the center of the bottom of 8C
As a result, the number of assembling steps is reduced, and die machining correction
Is easy. The lens barrel 1 is provided with a focusing guide.
A taper 18a is provided in the opening of the shaft hole 18C.
The guide axis for focus20A, 20BDifference
It is easy to insert. In the above-described embodiment, the intermediate frame 7 is
Focus guide for the second fixed lens holder 18 to be formed
The shaft hole 18C has a regular octagonal cross section.
Is a polygon such as a hexagonal prism or a decagonal prism.formMay be provided in the shape
No. [0060] According to the lens barrel of the present invention, the guide
The hollow part of the guide shaft hole that constitutes theformSet
Reduced assembly man-hours and assembly
Work efficiency has been improved due to ease of use, and lubricant
By preventing the guide bearing from flowing out
Is improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional side view of a main part of a lens barrel mounted on a video camera shown as an embodiment of the present invention. FIG. 2 is a front view showing a focus guide bearing hole of a second fixed lens holder that forms an intermediate frame provided inside the lens barrel. FIG. 3 is a longitudinal sectional view showing a focus guide bearing hole of a second fixed lens holder constituting an intermediate frame provided inside the lens barrel. FIG. 4 is a front view showing a guide bearing hole constituting a guide bearing portion provided inside a conventional lens barrel. FIG. 5 is a longitudinal sectional view showing a guide bearing hole of a guide bearing portion provided inside a conventional lens barrel. [Description of References] 1 lens barrel, 2 barrel, 3 front barrel, 4 rear barrel,
5 zoom unit, 6 iris unit, 7 middle frame,
8 focus unit, 11 zoom lens structure (movable lens structure), 18 second fixed lens holder, 18C
Focus guide shaft hole, 18a Taper of guide shaft hole for focus, 18b Hollow portion of guide shaft hole for focus, 20 Guide shaft for focus, 21 Focus lens drive mechanism (lens drive means), 22 Focus lens assembly (Movable lens assembly) )

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-7-42741 (JP, A) JP-A-61-151510 (JP, A) JP-A-62-150211 (JP, A) 93763 (JP, A) JP-A-62-266220 (JP, A) JP-A-5-142703 (JP, A) JP-A-5-210218 (JP, A) JP-A-5-71809 (JP, U) Japanese Utility Model Application Showa 57-176478 (JP, U) Japanese Utility Model Application Showa 49-139470 (JP, U) Japanese Utility Model Application Hei 5-75715 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G02B 7/02-7/16 G03B 17/00-17/02 F16C 29/00-31/06

Claims (1)

(57) [Claim 1] A lens barrel integrally formed with a guide bearing portion having a guide shaft hole in an optical axis direction on an inner wall, and a tip portion is inserted into a bottom portion of the guide shaft hole. Te and circular cross section of the guide shaft a lubricant is applied while being supported, and a movable lens structure which is movement operation in the optical axis direction by this is supported by the guide shaft lens driving means, the guide shaft hole, hollow Part is provided in a polygonal shape and the bottom
A shaft hole that does not have a through hole in the surface,
A lens barrel, wherein an outer peripheral surface is supported by an inner side surface of the guide shaft hole .