JPH08248293A - Lens barrel - Google Patents

Abstract

PURPOSE: To secure a stable moving operation of a movable lens structural body constituting a lens barrel and to maintain the normal moving operation. CONSTITUTION: This lens barrel is provided with a lens barrel 4, a guide shaft 20 supported inside the lens barrel 4, a lens driving means 21 having yoke parts 23 and 29 where a coupling part 23A, outside yoke parts 23C and 24C and inside yoke parts 23B and 24B are formed and a magnet 25 and fixed inside the lens barrel 4, the movable lens structural body 22 having a lens group 26, a lens holder 27, a coil bobbin 28, a coil 29, and a flexible print cable 30, supported by the guide shaft 20 inside the lens barrel 4 and operated to move in an optical axis direction by the lens driving means 21.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens barrel provided in a video camera or the like, and more specifically, a driving current is supplied to a movable lens structure housed movably inside the barrel through a flexible printed cable. And a lens barrel which is adapted to do so.

[0002]

2. Description of the Related Art For example, a video camera is equipped with an autofocus mechanism for automatically focusing on a subject and an electric zoom mechanism for changing the magnification.
The autofocus mechanism and the electric zoom mechanism are achieved by a lens barrel including a focus lens and a zoom lens, which are moved in the optical axis direction by driving means inside the barrel.

In the lens barrel, a movable lens structure is constructed by assembling a focus lens and a zoom lens to a lens holder movably mounted on guide shafts supported in the optical axis direction inside the lens barrel. These lens structures are moved by the drive means along the guide axis. The drive means of the zoom lens structure determines the Wide end and the Tele end of the lens system of the video camera and moves the zoom lens structure into the lens barrel with a large amount of movement. Therefore, the drive means for this zoom lens structure is generally
The zoom lens drive unit includes a stepping motor as a drive source and a rotation-linear motion conversion mechanism that converts the rotational motion of the stepping motor into a linear motion.

On the other hand, as shown in FIG. 6, the drive means of the focus lens structure is provided with a focus lens structure 102 for forming a subject image on the image pickup surface of the CCD solid-state image pickup device arranged at the rear end of the lens barrel. It is moved responsively along the optical axis. Therefore, the focus lens structure 1
The drive unit 02 is generally composed of a linear motor. Specifically, the linear motor includes a coil frame 10 integrally combined with the focus lens structure 102.
3, a yoke 104 disposed on the lens barrel 101 side, and a magnet 105 attached to each yoke piece of this yoke.

When a drive current is supplied to the coil 106 of the coil frame 103 by the control output from the controller, the linear motor causes a magnetic flux to be generated between the coil and the yoke in accordance with the direction of the drive current. Further, the magnetic flux generates a magnetic propulsion force that moves the focus lens structure 102 along the guide shaft 107 in the optical axis direction. Therefore, the focus lens structure 102 is moved in the optical axis direction in the lens barrel 101 by this magnetic propulsion force to form a subject image on the imaging surface of the CCD solid-state imaging device.

The lens barrel 100 has a coil frame 1 integrally combined with the above-mentioned focus lens structure 102.
A flexible printed cable 108 is provided to supply a driving current to the coil 106 of No. 03.
In the lens barrel 101, a cable pull-out portion 109 for pulling out the flexible print cable 108 to the outside of the lens barrel 101 in order to connect the flexible print cable 108 to a power source for supplying a drive current is provided at the outer edge portion of the opening. . Further, the focus lens structure 102 is
A terminal connecting portion 110 for connecting the flexible printed cable 108 is provided on the front surface portion of the lens barrel 101 in the optical axis direction. Both ends of the coil 106 are supported by the terminal connecting portion 110 of the focus lens structure 102.

The flexible printed cable 108 is
The support portion 108A and the connection portion 108B are provided at one end, and the support portion 108 is provided at the cable pullout portion 109 of the lens barrel 101.
A is supported and connected to a power source (not shown).
The tip of 8B is connected. Further, the flexible printed cable 109 is attached to the terminal connecting portion 110 of the focus lens structure 102 with the connecting plate 108C provided at the other end, and is soldered to both ends 106A of the coil 106 drawn out to the connecting terminal portion 110. ing.

[0008]

By the way, since the above-mentioned flexible printed cable 108 has flexibility, as shown by the arrow P in FIG.
When the focus lens structure 102 is moved toward the front surface of the lens barrel 102, the amount of bending gradually increases, and a large reaction force is generated in the direction of the rear surface of the lens barrel 101 in accordance with the amount of this bending. The flexible printed cable 108 is bent into a substantially V shape when the focus lens structure 102 is close to the opening of the lens barrel 101, and the amount of bending is maximized and the reaction force toward the rear surface portion is increased. It will be the maximum.

Therefore, in the lens barrel 100, with the focus lens structure 102 stopped at the designated position,
There is a problem in that the reaction force of the flexible printed cable 108 causes the focus lens structure 102 to shake.

Further, the focus lens structure 102 is caused by the reaction force of the flexible printed cable 108.
A large load is applied when moving. For this reason, the lens barrel 100 requires a larger driving force when the focus lens structure 102 subjected to a large load is moved. Therefore, the lens barrel 100
It is conceivable that the number of turns of the coil 106 is increased or the magnet 105 attached to the lens barrel 101 is made larger. However, the overall outer shape of the lens barrel 100 is further increased and the weight is further increased. The problem arises that Therefore, in the conventional lens barrel 100, there is a problem that the focus lens structure 102 cannot stably move and the focus operation cannot be performed with high accuracy.

The above-mentioned problem of the flexible printed cable 108 is not a problem peculiar to the movement operation of the focus lens structure 102 of the autofocus mechanism mounted on the video camera, and is provided in the lens barrel of other devices. This is also a problem common to flexible printed cables with movable lens structures.

Therefore, it is an object of the present invention to provide a lens barrel in which a reaction force generated by a flexible printed cable is reduced, a stable movement operation of a focus lens structure is ensured, and a normal movement operation is maintained. It was proposed to.

[0013]

A lens barrel according to the present invention that achieves this object includes a lens barrel, a guide shaft supported inside the lens barrel, and outer yoke portions that are mutually connected via a connecting portion. A lens driving unit fixed to the inside of the lens barrel, which has a yoke having an inner yoke portion and a magnet fixed to the yoke, a lens group, a lens holder for holding the lens group, and A coil bobbin provided on the lens holder, and a coil wound around the coil bobbin,
A flexible printed cable to which both ends of the coil are connected, and a movable lens structure which is supported by a guide shaft inside the lens barrel and is moved along the optical axis direction by the lens driving means. .

[0014]

According to the lens barrel of the present invention configured as described above, when the driving current is supplied to the coil combined with the movable lens structure by the flexible printed cable connected to the power source, the lens driving means is provided. The movable lens structure is supported by the guide shaft and moved in the lens barrel by the magnetic thrust generated in the. The lens barrel supports the lead-in portion of the flexible printed cable in the cable lead-out portion of the lens barrel and is opposite to the side surface portion facing the one side surface portion of the lens barrel forming the movable lens structure on the cable lead-out portion side. By connecting one end of the flexible printed cable to the terminal connection portion provided on the side surface, the flexible printed cable is always held in a largely curved state, and the movable lens structure is moved without causing shake. Will be stopped at the specified position.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the present invention will be described in detail below with reference to the drawings. The embodiment shows a lens barrel 1 mounted on a video camera and provided with an autofocus lens mechanism for automatically focusing on a subject and an electric zoom mechanism for changing magnification. The lens barrel 1 is
As shown in FIG. 1, there is provided a lens barrel 2 formed by combining a front lens barrel 3 formed in a cylindrical shape and a rear lens barrel 4 formed in a rectangular tube shape.

As shown in FIGS. 1 to 5, the lens barrel 1 includes a zoom unit 5 and an iris unit 6 inside the barrel 2 in order from the front side of the lens barrel 1 along the optical axis.
The intermediate frame 7 and the focus unit 8 are arranged. In the following description, “front” means the left side in FIG. 1, and “rear” means the right side.

The front lens barrel 3 has a slightly larger opening diameter than the rear lens barrel 4. The front surface of the front lens barrel 3 is open, and the first fixed lens holder portion 3A is provided on the front surface facing the opening. The first fixed lens holder portion 3A is provided with a first fixed lens mounting hole 3B in this central region, and the first fixed lens group 9 is fixed in the first fixed lens mounting hole 3B. . The “fixed lens group” is one or a plurality of lens groups that are not moved in the optical axis direction at the time of shooting and are incorporated in the lens barrel. Also, the front lens barrel 3 is
Inside this, a guide shaft hole 3C for zooming is provided in the corner portions of the front surface portion facing each other.

The zoom unit 5 includes a zoom guide shaft 1
0 (10A, 10B) and these zoom guide shafts 10
A zoom lens structure 11 penetratingly supported by and movable in the optical axis direction, a zoom lens drive mechanism (not shown) located on the upper surface of the front barrel 3 to drive the zoom lens structure 11, and the zoom The first position detection sensor 12 is located below the lens driving mechanism and near the zoom guide shaft 10 to detect the position of the zoom lens structure 11.

The zoom guide shafts 10 have the same length dimension as each other and have a length dimension sufficient to secure the movement amount of the zoom lens structure 11. Further, a relatively viscous lubricant such as grease is applied to the zoom guide shaft 10.

The zoom lens structure 11 is composed of a zoom lens group 13 and a zoom lens holder 14 which holds the zoom lens group 13, and determines the Wide end and the Tele end of the lens system of the video camera. The “movable lens group” refers to one or a plurality of lens groups that are moved in the optical axis direction in the lens barrel during shooting. The zoom lens group 13 functions as a so-called zoom lens, and is combined with the first fixed lens group 9 to adjust the angle of view.

The zoom lens holder 14 has a disk-shaped outer shape, and its outer diameter is smaller than the inner diameter of the front lens barrel 3. The zoom lens holder 14 is provided with a zoom lens mounting hole 14A in this intermediate region, and the zoom lens group 13 is fixed to this zoom lens mounting hole 14A.

Further, the zoom lens holder 14 is located on this side surface, and the zoom guide bearing portion 14 has a distance dimension which is equal to the distance between the zoom guide shafts 10.
B and 14C are provided facing each other. The zoom guide bearing portions 14B and 14C are formed at positions opposite to each other by 180 ° and penetrate through the zoom guide shaft 10 in the optical axis direction. A position detection piece 14D having a semicircular cross section is formed on the side surface of the zoom lens holder 14 along the zoom guide bearing portion 14B.

The zoom lens drive mechanism (not shown) is composed of a drive motor and a rotation-linear motion conversion mechanism attached to one side surface of the drive motor. The drive motor is
A first flexible printed cable (not shown) connected to a power supply to which a drive current is supplied is connected to the other side surface. A drive current is supplied to the drive motor to rotate it. A stepping motor is used as the drive motor. In the rotation-linear motion conversion mechanism, a driver element engaged with the zoom lens structure 11 is screwed into a rotary shaft whose outer peripheral portion is threaded. In the rotation-linear motion conversion mechanism, when the rotary shaft is rotated, the driver is moved in the optical axis direction.

The first position detecting sensor 12 receives light received over the moving area of the position detecting piece 14D integrally formed with the zoom lens holder 14 in a state where the first flexible printed cable is assembled to the front lens barrel 3. It is composed of an optical detection sensor including an element and a light emitting element.

As shown in FIG. 1, the iris unit 6 includes a base member 15 including a disk-shaped base portion 15A and a motor mounting portion 15B integrally provided on the side surface of the base portion 15A, and the motor mounting portion. 15B and the drive motor 16 attached to it. The base portion 15A of the base member 15 has a diaphragm hole 15 whose optical axis coincides with that of each lens group.
C is formed in the center. Further, in detail, the base portion 15A is configured by stacking two thin disks, and a plurality of diaphragm blades are incorporated inside.

In the iris unit 6, the drive motor 16 is driven by the output from the control unit to drive the diaphragm blades to adjust the aperture size of the diaphragm hole 15C. The amount of light of the lens barrel 1 is adjusted by the operation of the iris unit 6. Of course, the iris unit 6 may be composed of, for example, an iris unit using an electrochromic element.

The intermediate frame 7 includes a second fixed lens group 17 and
It is composed of a second fixed lens holder 18 that holds the second fixed lens group 17. The second fixed lens holder 18 is formed in a substantially rectangular shape, and its outer dimensions are formed to be substantially the same as the outer dimensions of the rear barrel 4. The second fixed lens holder 18 is provided with a second fixed lens mounting hole 18A at the center thereof, and the second fixed lens group 17 is fixed to the second fixed lens mounting hole 18A.
In addition, the second fixed lens holder 18 has a zoom guide shaft hole 18B formed in a corner portion of the rear surface portion. The second fixed lens holder 18 is provided with a focus guide shaft hole 18C at the corner portions of the front surface portion facing each other.

The rear lens barrel 4 has an opening on its front surface, and a CCD solid-state image pickup device 19 is arranged on its rear surface facing the opening. Further, the rear lens barrel 4 is provided with focusing guide shaft holes 4A at the opposite corners of the inner surface of the rear surface portion. The rear lens barrel 4 is provided with a second position detection sensor mounting port (not shown) in the central region of the bottom surface. The rear lens barrel 4 is provided with a zoom guide shaft hole 4B on the side surfaces of the opposite corner portions of the opening. Further, the rear lens barrel 4 is provided with a cable lead-out portion 4C formed in a substantially U-shape on the bottom surface side facing the zoom guide shaft hole 4B on the front surface portion.

The focus unit 8 includes a focus guide shaft 20 (20A, 20B), a focus lens drive mechanism 21 composed of constituent members housed or fixed in the rear lens barrel 4, and a focus guide shaft 20. The focus lens structure 22 is supported by and is movable in the optical axis direction, and a second position detection sensor (not shown) attached to the second position detection sensor attachment port of the rear lens barrel 4.

The focusing guide shaft 20 has a length dimension sufficient to secure the amount of movement of the focusing lens structure 22. Further, in order to ensure the slidability of the focus lens structure 22 that is moved at a relatively high speed, a relatively low-viscosity lubricant such as fluorine-based oil is applied to the focus guide shaft 20 of the focus guide shaft 20. It is evenly applied throughout.

The focus lens drive mechanism 21 comprises a first yoke 23A and a second yoke 24 made of metal, and magnets 25 fixed to these two yokes.

First yoke 23 and second yoke 24
Are connecting portions 23A and 24A that are screwed to the rear surface inside the rear lens barrel 4, and inner yoke portions 23B and 24B that are formed to rise from one side edge of the connecting portions 23A and 24A in the optical axis direction. The outer yoke portions 23C and 24C are formed in a substantially U shape so as to face the inner yoke portions 23B and 24B and rise from the other side edge of the coupling portions 23A and 24A in the optical axis direction.

The magnet 25 is fixed to the inner surfaces of the first yoke 23A and the second yoke 24 facing the inner yoke portions 23B and 24B of the outer yoke portions 23C and 24C, respectively, by an adhesive or the like. The magnets 25 are magnetized so that the magnetic poles are different in the directions from the outer yoke portions 23C and 24C toward the inner yoke portions 23B and 24B, respectively.
A closed magnetic circuit is formed between C and the inner yoke portions 23B and 24B.

The focus lens structure 22 includes a focus lens group 26, a focus lens holder 27 for holding the focus lens group 26, a coil bobbin 28 formed integrally with the focus lens holder 27,
The coil 29 is wound around the coil bobbin 28, and the second flexible printed cable 30 is connected to both ends 29A of the coil 29. The focus lens group 26 functions as a focus lens,
Focus adjustment is performed in combination with the second fixed lens group 17.

The focus lens holder 27 has a rectangular outer shape, and its outer dimension is smaller than the inner dimension of the rear lens barrel 4. The focus lens holder 27 is
A focus lens mounting hole 27A is provided in this intermediate region, and the focus lens group 26 is fixed in this focus lens mounting hole 27A.

In the focus lens holder 27, when the focus lens structure 22 is combined with the focus lens driving mechanism 21, a penetrating space portion 27B is provided at a position corresponding to the tip of the inner yoke portions 23B and 24B of the yokes 23 and 24. It is provided. The penetrating space portion 27B has an opening dimension slightly larger than the thickness dimension of the tips of the inner yoke portions 23B and 24B, and the focus lens structure 22 is supported by the focusing guide shaft 20 to move in the optical axis direction. At this time, the tip portions of the inner yoke portions 23B and 24B of the focus lens drive mechanism 21 can be penetrated. A coil bobbin 28 is integrally provided on the rear surface side of the focus lens holder 27, and a coil 29 is wound around the outer peripheral portion of the coil bobbin 28.

The focus lens holder 27 is located on the side surface of the coil bobbin 28 and has focus guide bearing portions 27C and 27D facing each other and having a distance equal to the distance between the focus guide shaft 20 and the focus guide shaft. It is provided. Focus guide bearings 27C, 27D
Are formed at positions opposed to each other by 180 °, and the focusing guide shafts 20 are respectively penetrated therethrough.

Further, the focus lens holder 27 includes
In a state where the focus lens structure 22 is incorporated in the rear lens barrel 4, the terminal connecting portion 3 is located on the side surface portion facing the rear surface portion of the rear lens barrel 4 and the bottom surface portion of the coil bobbin 28.
1 is provided. Both ends 29A of the coil 29 are drawn out to the terminal connecting portion 31.

Further, in the focus lens holder 27, the focus lens structure 22 is incorporated in the rear lens barrel 4 at a position facing a second position detection sensor mounting port (not shown) provided in the rear lens barrel 4. A magnet holder is provided, and a position detecting magnet is attached to the magnet holder.

Second flexible printed cable 30
Is a terminal connection portion 31 of the focus lens structure 22 at one end.
Is provided with a connecting plate 30A, and the other end of the support hole 3 is penetrated by the tip of the focusing guide shaft 20.
0B and a support portion 30C fitted in the cable pull-out portion 4C of the rear lens barrel 4 are provided.

The second position detection sensor (not shown) is attached to the second position detection sensor mounting port provided in the central region of the bottom surface of the rear lens barrel 4. The resistance value of the second position detection sensor changes due to the change in the magnetic flux density by the position detection magnet attached to the focus lens holder 27 of the focus lens structure 22, and the change amount is counted and the optical axis of the focus lens structure 22 is counted. Detect the direction position.

A method of assembling the embodiment lens barrel 1 having the above-described structure will be described below. The lens barrel 1 is
The focusing guide shafts 20 are inserted into the focusing guide shaft holes 4A of the rear lens barrel 4 and supported in a cantilevered state. Further, inside the rear lens barrel 4, a first yoke 23 and a second yoke 24 of the focus lens drive mechanism 21 are arranged in parallel to each other in parallel with the focusing guide shaft 20, and the rear lens barrel 4 of the rear lens barrel 4 is provided. It is fixed to the inner rear surface with screws.

The focusing guide shaft 20 has a focusing guide bearing portion 27C of the focusing lens assembly 22,
The focus lens structure 22 is supported so as to be movable in the optical axis direction by penetrating 27D. At this time, the focus lens structure 22 is combined with the first yoke 23A and the second yoke 24 of the focus lens drive mechanism 21 fixed inside the rear barrel 4. The focus lens structure 22 is combined with the focus lens drive mechanism 21, and the inner yoke portions 23B and 24B of the first yoke 23A and the second yoke 24 are penetrated through the penetrating space portion 27B.

The flexible printed cable 30 is connected to the terminal connecting portion 31 of the focus lens structure 22 by the connecting plate 30.
A is attached, and both ends 29A of the coil 29 are soldered to the connecting plate 30A. Further, the flexible printed cable 30 is curved gently and largely, and the support hole 30B is penetrated through the tip portion of the focusing guide shaft 20 which is supported by the rear lens barrel 4 in a cantilever state. The support portion 3 is attached to the cable lead-out portion 4C of 4
0C is fitted and supported. The flexible printed cable 30 is connected at its other end to a power source (not shown) and supplies a drive current to the coil 29.

The focusing guide shaft 20 has a leading end fitted with a focusing guide shaft hole 18C formed in the rear surface of the intermediate frame 7. At this time, the side surface of the intermediate frame 7 is fitted to the inner edge of the front surface of the rear lens barrel 4. The base portion 15A of the base member 15 forming the iris unit 6 is fitted to the front surface portion of the intermediate frame 7. At this time, in the iris unit 6, the drive motor 16 is located above the rear lens barrel 4, and the motor mounting portion 15B of the base member 15 is screwed to the outer edge portion of the front surface portion of the rear lens barrel 4.

The rear lens barrel 4 is supported in a cantilever state by inserting the zoom guide shafts 10 into the zoom guide shaft holes 4B. On the zoom guide shaft 10,
The zoom guide bearing portion 14B of the zoom lens structure 11,
By penetrating 14C, the zoom lens structure 11 is supported so as to be movable in the optical axis direction.

The zoom guide shaft 10 has a zoom guide shaft hole 3C formed in the front surface of the front barrel 3 at its tip. At this time, the front lens barrel 3 is screwed to the inner edge of the opening on the front surface side of the rear lens barrel 4. Finally, the front lens barrel 3 and the rear lens barrel 4 are screwed to the upper portion of a zoom lens drive mechanism (not shown),
The lens barrel 1 is assembled.

In the zoom unit 5 of the lens barrel 1 assembled as described above, when a drive current is supplied to the drive motor constituting the zoom lens drive mechanism from the power source (not shown), the drive motor is rotationally driven. This drive motor
When rotated, the rotary shaft of the rotation-linear motion conversion mechanism that constitutes the zoom lens drive mechanism is rotated. When the rotating shaft is rotated, the driving element assembled to the rotating shaft is moved in the optical axis direction. The driver is moved in the optical axis direction while being supported while being engaged with the zoom lens structure 11.

Therefore, the zoom lens structure 11 is supported by the zoom guide shaft 10 and moved in the optical axis direction by the zoom lens drive mechanism, as indicated by the arrow M in FIG. As a result, the zoom lens group 13 constituting the zoom lens structure 11 adjusts the distance between the zoom lens group 13 and the first fixed lens group 9 provided in the front lens barrel 3, and zoom control is performed.

Further, in the zoom lens structure 11, the position detecting piece 14D passes between the light receiving element and the light emitting element of the first position detecting sensor 12 when the central portion of the front lens barrel 3 is moved. The first position detection sensor 12 detects that the cutoff state between these elements has been released and sends a detection output to the control unit. The rotation operation of the stepping motor is controlled by the output of the position detection sensor 12.

Further, in the focus unit 8, the coil 29 integrated with the focus lens structure 22 forms the outer yoke portions 23C, 24C-magnet 25-inner yoke formed by the magnetic flux emitted from the magnet 25 constituting the focus lens driving mechanism 21. Part 23B, 24B-connecting part 23A, 2
4A—Closes the closed magnetic path that passes through the outer yoke portions 23C and 24C. When a drive current is supplied from a power source (not shown), the coil 29 generates a magnetic flux in a direction corresponding to the direction of the drive current to act on the closed magnetic circuit.

Therefore, the focus lens structure 22
2 is supported by the focusing guide shaft 20 by the magnetic thrust corresponding to the direction of the drive current supplied between the coil 29 and the closed magnetic path, as indicated by the arrow N in FIG. Move to work. As a result, the focus lens group 26 constituting the focus lens structure 22 is adjusted in the distance between the focus lens group 26 and the CCD solid-state image pickup device 19 arranged in the rear lens barrel 4 to perform focus control.
An image that has passed through the focus lens group 26 is captured on the CD solid-state image sensor 19.

Further, as the focus lens structure 22 is supported by the focus guide shaft 20 and moves in the axial direction, the position detection magnet attached to the focus lens holder 27 causes the second lens of the rear barrel 4 to move. By facing the second position detection sensor attached to the position detection sensor mounting port, the magnetic flux density exerted on the second position detection sensor is changed. The second position detection sensor detects the position of the focus lens structure 22 in the optical axis direction by counting the amount of change in the resistance value due to the change in the magnetic flux density.

Therefore, in the focus unit 8,
Based on the detected position of the focus lens assembly 22, the coil 29 of the focus lens drive mechanism 21 is powered on to control the movement operation of the focus lens assembly 22, and the focus lens attached to the focus lens holder 27. Focus control of the group 26 is performed.

Further, as the focus lens structure 22 is supported by the focus guide shaft 20 and moves in the axial direction, the connection plate 30A is connected to the terminal connection portion 31 of the focus lens holder 27, and the rear lens barrel 4 is attached. The amount of bending of the second flexible printed cable 30 in which the support portion 30C is supported by the cable pull-out portion 4C is changed.

Second flexible printed cable 30
As shown in FIG. 5, even when the focus lens structure 22 is moved to the front surface side of the rear lens barrel 4 and the amount of bending gradually changes, the state in which the lens is gently curved is largely maintained. Therefore, the second flexible printed cable 30 is rearwardly generated by the bending when the focus lens structure 22 is moved to the front end portion of the focusing guide shaft 20 and comes close to the front surface portion of the rear lens barrel 4. Lens barrel 4
The reaction force in the optical axis direction of is suppressed to a minimum.

Therefore, the focus lens structure 22
Since the reaction force of the rear lens barrel 4 of the second flexible printed cable 30 in the optical axis direction is minimized, is stably moved and stopped in a state where no shake occurs.

In the example lens barrel 1 described above,
Connection plate 30 of second flexible printed cable 30
Since A is connected to the terminal connecting portion 31 on the rear surface side of the focus lens structure 22 and the supporting portion 30C is supported by the cable pulling portion 4C on the opening side of the rear lens barrel 4,
The reaction force of the second flexible printed cable 30 on the focus lens structure 22 is reduced. Therefore, in the lens barrel 1, the load during the movement operation of the focus lens structure 22 is reduced and the shake of the focus lens structure 22 is prevented.

Further, in the above-mentioned embodiment, the terminal connecting portion 31 for connecting the second flexible printed cable 30.
Is provided on the rear surface portion of the focus lens structure 22, and a cable lead-out portion 4C for supporting the second flexible printed cable 30 is provided on the bottom surface side of the front surface portion of the rear lens barrel 4 facing the zoom guide shaft hole 4B. However, the terminal connecting portion 31 may be provided on the front surface portion of the focus lens structure 22 and the cable lead-out portion 4C may be provided on the rear surface portion of the rear lens barrel 4 in the vicinity of the focusing guide shaft hole 4A.

[0060]

As described in detail above, according to the lens barrel of the present invention, one end of the flexible printed cable is supported by the cable pull-out portion of the lens barrel, and the flexible printed cable is gently curved greatly. When the other end of the flexible printed cable is connected to the terminal connection part of the lens holder that constitutes the movable lens structure in the closed state, the reaction force of the flexible printed cable is reduced and the load during the moving operation of the movable lens structure is reduced. Is planned. Therefore, the lens barrel can ensure a stable movement operation of the movable lens structure, and can maintain a normal movement operation.

[Brief description of drawings]

FIG. 1 is a sectional side view of a main part of a lens barrel mounted in a video camera shown as an embodiment of the present invention.

FIG. 2 is a main-portion cross-sectional plan view for explaining the configuration of a focus unit provided inside the rear barrel of the lens barrel.

FIG. 3 is a front view illustrating the configuration of a focus unit provided inside the rear lens barrel of the lens barrel.

FIG. 4 is a cross-sectional front view of essential parts for explaining the configuration of a focus lens structure provided in the focus unit of the lens barrel.

FIG. 5 is a cross-sectional side view of essential parts for explaining a state in which a focus lens structure of a focus unit provided inside the rear barrel of the lens barrel moves.

FIG. 6 is a cross-sectional plan view of relevant parts for explaining the configuration of a focus unit provided inside a conventional lens barrel.

[Explanation of symbols]

 1 Lens barrel 2 Lens barrel 3 Front barrel 4 Rear barrel 4C Cable outlet 5 Zoom unit 6 Iris unit 7 Intermediate frame 8 Focus unit 11 Zoom lens structure (movable lens structure) 20 Focus guide shaft 21 Focus lens drive Mechanism (lens driving means) 22 Focus lens structure (movable lens structure) 23 Yoke 24 Yoke 25 Magnet 26 Focus lens group 27 Focus lens holder 28 Coil bobbin 29 Coil 30 Flexible print cable 31 Terminal connection part

Claims (2)

[Claims] 1. A lens barrel, a guide shaft supported inside the lens barrel, a yoke in which an outer yoke portion and an inner yoke portion are mutually formed via a connecting portion, and a magnet fixed to the yoke. And a lens driving means fixed inside the lens barrel, a movable lens group, a lens holder for holding the movable lens group, a coil bobbin provided on the lens holder, and a coil bobbin wound around the coil bobbin. A movable lens structure that has a coil and a flexible printed cable with both ends of the coil connected, is supported by a guide shaft inside the lens barrel, and is moved along the optical axis direction by the lens driving means; A cable lead-out portion is formed on the lens barrel at one side in the optical axis direction, and the lens holder has a coil and a flexible plug that are integrally combined. A lens barrel, wherein a connecting portion of the cement cable is formed is positioned on the other side of the optical axis direction. 2. The lens barrel according to claim 1, wherein the movable lens structure is a focus lens structure having a focus lens group, and the lens driving means is a focus lens driving mechanism.