JPH07120658A - Lens barrel - Google Patents

Abstract

PURPOSE:To improve the assembling efficiency without enlarging a lens barrel and prevent an non-required load from being given to a lens by designing the arrangement of a flexible printed board. CONSTITUTION:In the lens barrel having front and rear lens groups L2, L3 and L4 mutually arranged on the same axis, front and rear electric parts 21, 32, 32a and 53 integrated to the front and rear lens groups L2, L3 and L4, and front and rear flexible printed boards 63, 64 having conductive patterns formed on the surfaces to electrically connect each electric part to an electric part provided on the barrel outer part, at least one lens group being constituted in such a manner as to be drivable in the optical axial direction, the front and rear flexible printed boards 63, 65 are arranged in the lens barrel internal space in the state where they are mutually superposed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens barrel having at least two lens groups that can move relative to each other in the optical axis direction, and more particularly to a plurality of electric components integrated with each lens group by a flexible printed circuit board. The present invention relates to a lens barrel adapted to be electrically connected to the electric component.

[0002]

2. Description of the Related Art Conventionally, a plurality of electric control means (for example, a shutter driving device, a focusing motor, a zooming motor) provided inside a lens barrel is electrically connected to an electric component (control IC) provided outside the barrel. As a means for electrically connecting, a flexible substrate called a so-called flexible printed circuit board (FPC) is used. This kind of FPC
Has one end connected to a substrate inside the lens barrel on which electrical components are mounted, and is routed in a state in which the space inside the lens barrel is bent a plurality of times, and then the substrate whose tip is provided outside the lens barrel (control IC is mounted). As a result, the electrical components inside the lens barrel and the electrical components outside the lens barrel are electrically connected via the wiring pattern on the FPC. By using such an FPC, even when the electric component moves in the optical axis direction due to the movement of the lens group due to zooming or the like, it is possible to deal with it by appropriately deforming the FPC and applying an unreasonable load to the lens group. There is no.

[0003]

However, if a plurality of electric control means inside the lens barrel are connected to electric parts outside the lens barrel by one FPC, the number of wiring patterns on the FPC is very large. Therefore, it is necessary to widen the width of the FPC. When the width of the FPC is widened, when the FPC is stretched in a narrow space in the lens barrel, for example, in parallel with the optical axis, the FPC must be bent around the optical axis in accordance with the curvature of the barrel forming the lens barrel. In this case, it becomes difficult to bend the FPC in the front-rear direction of the optical axis, the assembling work efficiency decreases, and an undesired load is applied to the FPC when the lens group moves, which may cause disconnection.

Therefore, there is known one in which a plurality of electric control means inside the lens barrel are connected to electric parts outside the lens barrel by using different FPCs (Photo Industry Publishing Company, Photo Industry 1990). September issue P81-P83). However, in the device disclosed in this document, since each FPC is drawn out from the front and rear ends of the lens barrel to the outside of the lens barrel, it is necessary to secure a space for drawing out the FPC at both ends of the lens barrel. As a result, there is a problem that the lens barrel becomes large.

The object of the present invention is to improve the assembling work efficiency without increasing the size of the lens barrel by devising the arrangement of the flexible printed circuit board, and to prevent an undesired load from being applied to the lens. It is to provide a cylinder.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1 showing an embodiment, the present invention is directed to front and rear lens units L2, L3 and L4 arranged coaxially with each other, and to the front and rear sides thereof. Front and rear electrical components 21, 3 integrated into rear lens groups L2, L3 and L4, respectively
2, 42a and 53, and front and rear flexible printed circuit boards 63 and 65 each having a conductive pattern formed on the surface for electrically connecting each electric component to an electric component provided outside the lens barrel, It is applied to a lens barrel in which at least one lens group can be driven in the optical axis direction. Then, the front and rear flexible printed boards 63 and 65 are arranged in the space inside the lens barrel in a state of being overlapped with each other, thereby solving the above-mentioned problems. Particularly, in the invention of claim 2, after the rear flexible printed circuit board 65 is routed to the front end side of the lens barrel so as to be substantially parallel to the optical axis, the rear flexible printed circuit board 65 is arranged.
Is bent to the rear of the lens barrel in a state of being overlapped with the front flexible printed circuit board 63. According to the third aspect of the present invention, the flexible printed boards are superposed so that one surface and the other rear surface of the front and rear flexible printed boards 63 and 65 face each other. Further, the invention of claim 4 is the front electric component 2
1, 32, 42a are connected to the front flexible printed circuit board 63 on the front side of the holding member 42 holding the front lens group L2, and the rear electric component 53 is connected to the front side of the holding member 51 holding the rear lens group L4. It is connected to the rear flexible printed circuit board 65.

[0007]

Function: Front and rear flexible printed circuit boards 6
By providing 3, 65, respectively, the width of each flexible printed circuit board can be minimized, the flexible printed circuit board does not need to be bent around the optical axis, and the flexible printed circuit board can be naturally bent in the front-back direction. . Further, since the flexible printed circuit board is very thin, the flexible printed circuit boards are arranged in the space inside the lens barrel in a state of being superposed on each other, whereby the arrangement space can be minimized. Further, since the flexible printed boards can be pulled out from the same position to the outside of the lens barrel by arranging the flexible printed substrates in an overlapping manner, it is not necessary to provide a space for drawing out before and after the lens barrel.

Incidentally, in the section of means and action for solving the above-mentioned problems for explaining the constitution of the present invention, the drawings of the embodiments are used to make the present invention easy to understand. It is not limited to.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to FIGS. 1 and 2 are side sectional views showing a lens barrel-integrated camera (zoom camera) according to the present embodiment.
Shows a state in which the lens barrel is in the wide-angle position, and FIG. 2 shows a state in which the lens barrel is in the telephoto position. Reference numeral 2 denotes a fixed lens barrel fixed to the camera body 1. The fixed lens barrel 2 has linear grooves 2a and 2b formed in the optical axis direction on the peripheral surface thereof. A cam barrel 3 is rotatably fitted on the outer peripheral surface of the fixed lens barrel 2 and is retained by a ring 4. The rotation of the zoom motor 77 (FIG. 5) is transmitted to the gear portion 3d formed on the outer peripheral surface of the cam barrel 3 via the gear GR, whereby the cam barrel 3 rotates. Further, cam grooves 3a, 3b, 3c are formed on the peripheral surface of the cam barrel 3.

A lens substrate 5 is inserted through the inner peripheral surface of the fixed barrel 2, and a camera shake correction device 100 is held on the substrate 5. The image stabilizing apparatus 100 includes an image stabilizing lens group (hereinafter referred to as an image stabilizing lens) L3 held by a lens holder 6 and a drive mechanism 101 that drives the image stabilizing lens L3. For example, as shown in FIG. 3, an X-direction drive mechanism 10 that drives the anti-vibration lens L3 in the X direction and a Y-direction drive mechanism 20 that drives the anti-vibration lens L3 in the Y direction.
It consists of and. Here, both the X direction and the Y direction are directions orthogonal to the optical axis of the taking lens.

The Y-direction drive mechanism 20 includes a Y-direction motor 21.
And a gear 22 that rotates integrally with the output shaft of the motor 21
And a reduction gear train 23 that reduces the rotation of the gear 22,
A Y-direction shift drive shaft 24 connected to the gear train 23 and a Y-direction drive arm 25 for converting the rotation of the drive shaft 24 into a linear motion.
And have. The Y-direction shift drive shaft 24 is rotatably supported on the substrate 5 by a pair of flanges 24a and 24b, and a gear 24c that meshes with a final gear of the reduction gear train 23 is coupled to an upper portion of the Y-direction shift drive shaft 24 and a lower portion thereof. Male thread 2
4d is formed. The Y-direction drive arm 25 is held in a space formed on the substrate 5 so as to be able to move up and down and not to rotate, and a male screw portion 24d of the drive shaft 24 is screwed to a female screw portion 25a formed on the upper portion thereof.

A holding portion 25b is formed at the lower end of the driving arm 25, and the holding portion 25b is provided via four slider balls 26.
The upper connecting portion of the lens holder 6 is held by b. Therefore, as the drive arm 25 moves up and down, the lens holder 6, that is, the image stabilizing lens L3 is shifted in the Y direction in the drawing. The shift amount depends on the rotation amount of the motor 21. Further, the X-direction drive mechanism 10 is also configured to shift the image stabilizing lens L3 in the X-direction by the same configuration as the Y-direction drive mechanism 20.

A disk 31 having a plurality of concentric holes is rotatably attached to the gear 22, which rotates integrally with the output shaft of the Y-direction motor 21.
Reference numeral 32 is a well-known photo interrupter having a light projecting portion and a light receiving portion that face each other with the hole forming portion of the disc 31 interposed therebetween,
A pulse signal is output each time the photo interrupter 32 detects a hole in the disk 31. Therefore, the rotation amount of the motor (which depends on the shift amount of the image stabilizing lens L3) can be detected by counting the number of pulses. Also, X
A similar disk and photo interrupter are also provided on the direction motor side, and the amount of rotation of the motor is detected by this.

Here, in FIG. 3, one photo interrupter 32 is shown for each of the X and Y directions, but actually two photo interrupters 32 are provided for each direction as shown in FIG. A photo interrupter 32 is provided. The reason why two photo interrupters are used is to detect the moving direction as well as the moving amount of the image stabilizing lens L3. Reference numeral 33 is a spring that biases the lens holder 6 toward the Y-direction drive mechanism 20 and the X-direction drive mechanism 10, respectively.

In FIG. 1, a lens shutter mechanism 40 is integrally attached to the image stabilizing apparatus 100 constructed as described above. The lens shutter mechanism 40 is configured by integrating a shutter blade 41 that also serves as a diaphragm and a drive unit 42 that drives the shutter blade 41, and the drive unit 42 is screwed to the substrate 5 with a screw 43. An electric component 42a such as a motor for driving the shutter blades 41 is mounted on the drive unit 42, and a lens group L2 is held on the inner peripheral surface side of the drive unit 42 via a lens holder 44. Here, the cam follower 5a implanted in the substrate 5
Engages with the cam groove 3b by penetrating the straight groove 2b. A lens holder 45 that holds the lens unit L1 is inserted through the front end side of the fixed lens barrel 2, and a cam follower 45a that is planted on the outer peripheral surface of the lens holder 45 penetrates the rectilinear groove 2a and is engaged with the cam groove 3a.

Further, on the rear side of the fixed lens barrel 2, a lens substrate 51 having a helicoid 51a formed on the inner peripheral surface thereof is inserted, and a cam follower 51b planted on the outer peripheral surface thereof penetrates the rectilinear groove 2b to form a cam. It is engaged with the groove 3c. A lens holder 52 holds the focusing lens L4, and a helicoid 52a formed on the outer peripheral surface of the lens holder 52 is screwed into the helicoid 51a of the lens substrate 51. Further, a gear 53a integral with the output shaft of the focusing motor 53 is screwed into the helicoid 51a.
The lens holder 52 is rotated by the rotation of. When the lens holder 52 rotates, the lens holder 52, that is, the focusing lens L4 moves in the optical axis direction by the action of the helicoids 51a and 52a, whereby focusing is performed. Here, each of the lens groups L1 to L4 described above
The photographic lens optical system is constituted by.

Reference numeral 54 denotes an FPC guide member which extends in the optical axis direction between the image stabilizer 100, the lens shutter mechanism 40 and the lens holder 45, and is held by the camera body 1 slidably in the optical axis direction. . A long hole 54a in the optical axis direction is formed in the guide member 54, and a stepped screw 55 penetrating therethrough is screwed into the lens substrate 51. Therefore, the lens substrate 51 moves in the optical axis direction while being guided by the elongated hole 54a during zooming, which will be described later.
When reaches the front end of the long hole 54a, the lens substrate 51 and the guide member 54 move integrally. 56 more
Is an FPC guide member provided along the inner peripheral surface of the rear portion of the cam barrel 3.

Reference numeral 61 denotes a substantially annular vibration-proof flexible printed circuit board (hereinafter referred to as a vibration-proof FPC) attached to the image stabilizing apparatus 100.
1 is an electrical component (X, Y
The direction motor 21 and each photo interrupter 32) are mounted. Further, the lower part of the FPC 61 is pulled out to the front of the camera along the optical axis through the hole provided in the lens substrate 5, and is soldered to the mounting substrate 62 attached to the left surface (front surface) of the shutter mechanism 40 in the drawing. Connected by. Electrical components 42a in the shutter drive section 42 are connected to the mounting substrate 62 by soldering, and a flexible printed circuit board for a shutter (FP for shutters) for connecting these electrical components 42a to a driver outside the lens barrel.
C) One end of 63 is connected.

An annular mounting substrate 64 is attached to the left surface (front surface) of the lens substrate 51 holding the focusing lens unit L4 in the figure, and the focusing motor 53 is connected to the substrate 64 by soldering.
One end of a focusing flexible printed circuit board (FPC for focusing) 65 for connecting the focusing motor 53 to a driver outside the lens barrel is connected.

As shown in the enlarged view of FIG. 4, the focusing FPC 65 is pulled out toward the front of the camera through the space between the camera shake correction device 100 and the lens shutter mechanism 40 and the FPC guide member 54, and the shutter FPC 63.
It is folded back in the state of being overlapped with. Here, conductive patterns are formed on the surfaces of the FPCs 63 and 65, and the surfaces (coverlay surfaces) 63a and 65a on which the conductive patterns are formed are the mounting boards 62 and 64, respectively.
The FPCs 63 and 65 are connected to the mounting board so as to face the same direction as the soldering surfaces (left surfaces) 62a and 64a. Therefore, each FPC has a cover lay surface of the FPC 65 and the FP.
The back surface of C63 (a surface on which no conductive pattern is formed, which will be referred to as a base surface hereinafter) is overlapped in a state of being opposed.

FPC 63 bent to the rear of the camera,
Reference numeral 65 denotes an FPC while maintaining a state of being superposed on each other.
After passing through the space between the guide member 54 and the lens substrate 45, it is drawn to the rear of the camera, bent again toward the front of the camera, and then passes through the space between the FPC guide member 56 and the cam barrel 3 at the upper side to the lens mirror. It is drawn out of the cylinder, and its tip is guided to the upper part of the camera body 1. A control IC 71 shown in FIG. 5 is mounted on a board 66 fixed to the upper part of the camera body 1, and a zoom driver 72, a shutter driver 73, a camera shake correction motor driver 74 connected to the control IC 71, Image stabilization motor drive amount detection circuit 75
And a focusing motor driver 76 are mounted,
A zoom motor 77 is connected to the zoom driver 72. Then, the tip ends of the FPCs 63 and 65 are pressure-contacted and connected onto the substrate 66 via a pressing plate 67 and a mounting screw 68, respectively.

In FIG. 5, the control IC 71 is also connected with a known photometry circuit 81, a distance measurement circuit 82, and a camera shake sensor 83 for detecting the camera shake amount due to camera shake. The shutter driver 73 is connected to the shutter driving electric component 42a via the mounting board 62 and the shutter FPC 63 described above, and the camera shake correction motor driver 74 and the camera shake correction motor drive amount detection circuit 75 are provided with the image stabilization function. The X and Y direction motors 21 and the photo interrupters 32 in the X and Y directions are connected via the FPC 61, the mounting substrate 62, and the shutter FPC 63, respectively. The camera shake correction motor drive amount detection circuit 75, on the basis of the output of the photo interrupter 32, drives the drive amounts and drive directions of the X and Y direction motors 21, that is, the image stabilizing lens L3.
The moving amount and the moving direction of are detected and input to the control IC 71.

Further, the focusing motor driver 7
6 includes a mounting substrate 64 and a focusing FPC 65.
The focusing motor 53 is connected via. Further, the control IC 71 is connected to a half-press switch SW1 which is turned on by half-pressing the release button, a release switch SW2 which is turned on by fully-pressing the release button, and zooming switches SW3 and SW4.

The control IC 71 activates the photometry circuit 81 and the distance measuring circuit 82 when the half-push switch SW1 is turned on, and drives the focusing motor 53 based on the detection output of the distance measuring circuit 82 to move the focusing lens L4. Focusing is performed by moving in the optical axis direction.
Further, when the release switch SW2 is turned on, the shutter drive electric component 42a is drive-controlled based on the output of the photometric circuit 81 to open / close the shutter blade 41. further,
During the shutter release, the X- and Y-direction motors 21 are drive-controlled based on the output of the camera shake sensor 83 and the output of the camera shake correction motor drive amount detection circuit 75, so that the image stabilizing lens L3 is appropriately moved in the direction orthogonal to the optical axis. It is moved to prevent image blur caused by camera shake.

Further, zooming switches SW3 and SW4
When is turned on, the control IC 71 drives the zoom motor 77 to rotate the cam barrel 3 via the gear GR. Since the cam grooves 3a, 3b, 3c move as the cam barrel 3 rotates, the lens holder 45, the lens substrates 5, 51 are driven in the optical axis direction via the cam followers 45a, 5a, 53a, respectively. Thus, the lens groups L1 to L4 are driven between the wide-angle position shown in FIG. 1 and the telephoto position shown in FIG. 2 to perform zooming. Each F along with this zooming
Since the PCs 63 and 65 are appropriately deformed as shown in the drawing, an unreasonable load is not applied to the lens groups L1 to L4.

As described above, in the present embodiment, the FPC 63 for connecting the electric components constituting the shutter mechanism 40 and the image stabilizing device 100 to the electric components outside the lens barrel, and the focusing motor 53 are connected to the electric components outside the lens barrel. Since the FPC 65 for connecting to the parts is separately provided, each FPC 63,
The width of 65 can be minimized. Therefore, it is not necessary to bend the FPC around the optical axis, and the FPC can be easily bent in the front-rear direction, and the assemblability can be improved. Further, since the FPC is generally very thin, even if the two FPCs 63 and 65 are overlapped with each other as described above, the FPC does not become so thick, so that the arrangement space can be minimized. In addition, since the FPCs 63 and 65 can be drawn out of the lens barrel from the same position by overlapping the FPCs 63 and 65 with each other, it is not necessary to provide a space for drawing out the FPCs in the front and rear of the lens barrel. The size of the lens barrel can be reduced.

In particular, in this embodiment, both the FPC 63 and the FPC 65 are placed so that the base surface and the coverlay surface of the FPC 65 face each other.
Since the PCs 63 and 65 are overlapped with each other, the configuration shown in FIG.
As shown in, each of the FPCs 63, 65 drawn out of the lens barrel
The tip of the FPC can be pressed and connected on the same surface of the substrate 66 without crossing or twisting.
Assembling is not hindered by the provision of the book.

In the construction of the above embodiment, the lens unit L
2, L3 are the front lens group, the lens group L4 is the rear lens group, the camera shake correction motor 21, the photo interrupter 32, and the shutter driving electric component 42a are the front electric components, and the focusing motor 53 is the rear electric component. Parts
FPC 63 is the front flexible printed circuit board, FPC
65 constitutes the rear flexible printed circuit boards.

In the above description, the two FPCs 63 and 65 are superposed on each other, but three or more FPCs integrated with three or more lens groups may be superposed on each other. Further, the electric components in the lens barrel are not limited to those described above, and may be, for example, an encoder for detecting the focal length of the zoom lens or an encoder for detecting the position of the focusing lens. further,
The electric parts in the lens barrel are mounted on the boards 62 and 64, and one ends of the FPCs 63 and 65 are connected to the boards 62 and 64, respectively.
The electric components may be mounted on the FPC integrated with the C63 and C65. In the above description, the lens-integrated camera has been described, but the present invention can be applied to, for example, an interchangeable lens mounted on a single-lens reflex camera. In this case, the tips of a plurality of FPCs that are overlapped with each other are connected to the contacts inside the interchangeable lens, and when the interchangeable lens is mounted on the camera body, the electrical power inside the lens barrel is passed through the contacts and the contacts on the camera body side. The components may be configured to be connected to the electrical components inside the camera body.

[0030]

According to the present invention, since the front and rear flexible printed boards are arranged in the space inside the lens barrel in a state of being superposed on each other, the width of each flexible printed board is minimized. You can
There is no need to bend the flexible printed circuit board around the optical axis. Therefore, the flexible printed circuit board can be bent in the front-rear direction without difficulty, the assembling work efficiency can be improved, and an unreasonable load is not applied when the lens group is moved. In addition, by arranging the flexible printed circuit boards in an overlapping manner, the limited space inside the lens barrel can be efficiently used, and the flexible printed circuit boards can be pulled out from the same position outside the lens barrel. It is not necessary to provide a space for drawing the space in front of and behind the lens barrel, and the lens barrel can be downsized.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a camera having a lens barrel according to the present invention, showing a state in which the lens barrel is in a wide-angle position.

FIG. 2 is a view similar to FIG. 1, showing a state in which the lens barrel is in the telephoto position.

FIG. 3 is a diagram showing details of a camera shake correction device.

FIG. 4 is an enlarged view of a main part of FIG.

FIG. 5 is a diagram showing a configuration of a control system of the camera.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 camera body 2 fixed lens barrel 3 cam barrel 21 camera shake correction motor 32 photo interrupter 40 shutter mechanism 41 shutter blades 42 shutter drive section 42a shutter drive electric parts 54, 56 FPC guide member 61 vibration isolation FPC 63 shutter FPC 63a , 65a Coverlay surface 63b, 65b Base surface 65 Focusing FPC 71 Control IC 100 Image stabilizer 101 Drive mechanism L1 to L4 Lens group

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Junichi Omi 3 2-3 Marunouchi, Chiyoda-ku, Tokyo Stock Company Nikon (72) Inventor Yoshihiro Takeuchi 3 2-3 Marunouchi, Chiyoda-ku, Tokyo Shares Ceremony Company Nikon

Claims (4)

[Claims] 1. A front lens group and a rear lens group, which are arranged coaxially with each other, front and rear electric components respectively integrated with the front lens group and the rear lens group, and the respective electric components outside the lens barrel. A lens barrel including front and rear flexible printed boards having conductive patterns formed on the surfaces thereof for electrically connecting to the provided electric parts, and configured to drive at least one lens group in the optical axis direction. In the lens barrel, the front flexible printed circuit board and the rear flexible printed circuit board are arranged in a space inside the lens barrel while being overlapped with each other. 2. The rear flexible printed circuit board is laid over the front end side of the lens barrel so as to be substantially parallel to the optical axis, and then the rear flexible printed circuit board is superposed on the front flexible printed circuit board. The lens barrel according to claim 1, wherein the lens barrel is bent rearward in the state. 3. The lens barrel according to claim 2, wherein the flexible printed boards are overlapped so that one surface of the front flexible printed circuit board and the back surface of the other flexible printed circuit board face each other. . 4. The front electric component is connected to the front flexible printed circuit board on the front side of a holding member that holds the front lens unit, and the rear electric component holds the rear lens unit. The lens barrel according to claim 3, wherein the lens barrel is connected to the rear flexible printed board on the front side of the member.