JP3395015B2 - Lens barrel - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a guide member for guiding a lens frame of a lens barrel in a straight line. 2. Description of the Related Art A mechanism for collapsing a lens barrel has been conventionally employed so as to be as small as possible when carried without using a camera. However, in order to further increase the collapsible amount and make the camera thinner. In recent years, a mechanism for double fitting a lens barrel has been widely used in compact cameras. That is, a fixed body fixed to the camera body, a movable body that moves in the optical axis direction while rotating inside the fixed body, a lens frame that holds a lens inside the movable body, and prevents rotation of the lens frame. By providing a guide member, the movable barrel is rotated to move the lens frame linearly in the optical axis direction. Conventionally, various mechanisms have been proposed and put into practical use with respect to this guide member, but each guide member has advantages and disadvantages, and it has not been satisfactory to achieve downsizing while maintaining predetermined performance. FIG. 4 is a schematic view of a first conventional example, in which a fixed barrel 101 and a movable barrel 102 and a movable barrel 102 and a lens frame 103 are helicoidally screwed, and a guide member 104 fixed to the fixed barrel 101. Are engaged with the linear guide portion 103a of the lens frame 103.
Accordingly, when the movable body 102 is rotated, the movable body 102 moves in the optical axis direction along with the rotation, but the lens frame 103 is prevented from rotating by the guide member 104, and moves only in the optical axis direction. In the first conventional example, the configuration of the guide member 104 is relatively simple, but since the guide member 104 must always be engaged with the lens frame 103, there is a problem that a sufficient collapsible amount cannot be obtained. There is. FIG. 5 is a schematic view of a second conventional example, in which a fixed body 111 and a movable body 112 are screwed into a helicoid, and a cam of the movable body 112 (not shown) and a lens frame 113 form a guide cylinder 112. The cam pins 113a are cam-coupled through the cam pins 113a. One end of the guide cylinder 114 is engaged with the linear guide section 111a of the fixed body 111, and the cam pin 113a and the linear guide section 114 of the guide cylinder 114 are engaged.
a is engaged. Therefore, when the movable body 112 is rotated, the movable body 112 moves in the optical axis direction with the rotation, but the rotation of the lens frame 113 is prevented by the guide cylinder 114, and only the movement in the optical axis direction is performed. In the second conventional example, the collapsible amount can be sufficiently obtained, but there is a problem that the lens barrel becomes thick because the movable barrel 112 and the guide cylinder 114 have a double configuration. FIG. 6 is a schematic view of a third conventional example, in which a fixed barrel 121 and a movable barrel 122, and a movable barrel 122 and a lens frame 123 are helicoidally screwed. The second guide member 125 is engaged with one end of the first guide member 124 by engaging with the linear guide portion 123a. Also, the first guide member 1
24 is integrally formed with the movable body 122,
Moves in the optical axis direction with rotation, whereas the first guide member 124 moves only in the optical axis direction and does not rotate.
Therefore, when the movable body 122 is rotated, the movable body 122 moves in the optical axis direction with the rotation, but the lens frame 123 is moved to the first guide member 1.
The rotation is prevented by the 24 and the second guide member 125, and only the movement in the optical axis direction is performed. In the third conventional example, the retracting amount can be sufficiently obtained and the lens barrel can be made thin, but two guide members are required. In addition, the positional accuracy of the lens barrel 123 in the rotation direction is
The positional accuracy between the lens frame 123 and the first guide member 124, the positional accuracy between the first guide member 124 and the second guide member 125, and the positional accuracy between the second guide member 125 and the fixed body 121 are determined at three positions. Therefore, there is a problem that it is difficult to sufficiently guarantee the positional accuracy in the rotation direction. [0006] [SUMMARY OF THE INVENTION The present gun onset Ming is to solve the problems of the prior art, on the amount of retraction can take enough, Kagamido径is thin, the rotating direction of the lens frame Are realized with a simple configuration . [0007] The above-mentioned object is achieved by providing a fixed body provided with a female helicoid and a guide groove on the inner circumference, and a male helicoid provided on the outer circumference to be screwed with the fixed body, and a female helicoid provided on the inner circumference. A movable body provided with a rib protruding in the inner circumferential direction at an end on the film surface side, a male helicoid screwed into the movable body and a guide groove, and a mirror carrying at least one group of photographing lenses Relative to the frame and the movable body
The movable barrel can be moved in the optical axis direction integrally with the movable barrel by rotating the movable barrel, and the lens frame can be moved.
A linear guide member that moves in the optical axis direction.
The advance guide member includes a second member and an object larger than the second member.
Is located on the side and is incorporated into the movable barrel
A state in which it is rotated about a fulcrum and sandwiches the rib of the movable body.
A first member screwed to the second member at
A first engaging portion that engages a second member with a guide groove of the fixed cylinder;
And a second engaging portion that engages with the guide groove of the lens frame.
This is achieved by a lens barrel characterized by having a configuration . An embodiment of the present invention will be described in detail with reference to FIGS. 1 and 2. FIG. 1 is an exploded perspective view of a zoom lens barrel according to the present invention, FIG. 2 is a cross-sectional view of the zoom lens barrel, and the upper half of the barrel has a wide focal length, and the lower half has a focal length. It is the figure selected to telephoto. Reference numeral 1 denotes a fixed body integrally fixed to the camera body, and a female helicoid 1a is screwed on an inner periphery thereof.
Straight guides to be described later are provided on the left and right sides of the female helicoid 1a.
A guide groove 1b (corresponding to the guide portion of the fixed barrel) for 21 (part or all of which corresponds to the second member) is provided across the female helicoid. Reference numeral 2 denotes a movable body, on the outer periphery of which a male helicoid 2a screwed with the female helicoid 1a and a large gear 2b are integrally formed, and on the inner periphery, a female helicoid 2c.
And a cam groove 2d (inner cam), and a rib 2e is provided inward of the rear end. When the movable body 2 and the large gear 2b are integrally formed of resin, the large gear 2b is arranged on the rear end face of the movable body 2 so that the molding die is not divided and molded, but is integrally formed in the direction in which the mold is removed. Therefore, highly accurate parts can be manufactured with a simple mold structure. Reference numeral 3 denotes an FC sliding frame to which an FC lens frame 4 holding an FC lens group 5 having a combined focal length of (+) is attached from the front with screws. The outer periphery of the FC sliding frame 3 is provided with a male helicoid 3a screwed with the female helicoid 2c and a guide groove 3b (corresponding to a guide portion of a movable body) for a rectilinear guide 21 to be described later. Hole 3c is formed. Reference numeral 6 denotes an RC sliding frame, which holds an RC lens group 7 having a combined focal length of (-) on the inner periphery, and has a guide groove 6a for a rectilinear guide 21 described later on the outer periphery and a cam groove 2 on the outer periphery.
An RC cam pin 8 that engages with d is buried, and a guide shaft 11 protrudes forward. Reference numeral 13 denotes a shaft spring inserted into the guide shaft 11, and reference numeral 12 denotes an E-shaped retaining ring for preventing the shaft spring 13 from coming off. Reference numeral 21 denotes a linear guide, which slides on the guide groove 1b of the fixed body 1 at left and right protrusions 21a (corresponding to first engagement portions), and allows a drive gear 44 to be described later to be rotatable by another protrusion 21b. Arm 21 that is pivoted and bent forward
At c (corresponding to the second engagement portion), the guide groove 3b and the guide groove 6a slide. 22 is a guide fixing plate (corresponding to the first member) for connecting the movable body 2 and the linear guide 21, 23 is a linear guide
A guide fixing shaft for connecting the movable body 2 to the guide fixing plate 22 and holding the movable body 2 by the rib 2e, and a set screw 24 for holding the linear guide 21 to the guide fixed shaft 23 (the linear guide 21 and the guide
The connecting plate 22 is used as a straight guide member.
This) . Reference numeral 31 denotes a lens barrel drive motor. A propeller 33 for LDP1 is attached to a shaft 32 of the motor. A signal LDP1 is generated by a photointerrupter 34 for LDP1. Reference numeral 35 denotes a pinion directly connected to the motor. The rotation of the motor 31 is controlled by a first gear 36, a second gear 37, a third gear 38, and a fourth gear 42 to a fifth gear 43 provided with a long gear in the optical axis direction. And transmitted to the drive gear 44. The drive gear 44 meshes with the large gear 2b of the movable barrel 2. The shaft of the third gear 38
The LDP2 propeller 40 is attached to 39, and the LDP2
The signal LDP2 is generated by the photointerrupter 41. The signals LDP1 and LDP2 are signals for controlling the lens barrel drive motor. A shutter 52 and a shutter driving motor 53 are mounted on the FC sliding frame 3. Reference numeral 51 denotes an FPC board, which connects a shutter driving motor 53 to a printed board 54 on which electric components on the main body side are mounted. After being connected to the shutter driving motor 53, the FPC board 51 passes through the gap between the arm portion 21c of the rectilinear guide 21 and the inner periphery of the movable barrel 2 behind the camera, and is folded back at the rear end 2f of the movable barrel 2 so that the camera It passes through the gap between the outer periphery of the movable barrel 2 and the fixed barrel 1 forward. A hole 1c is provided in front of the camera from the rear end 2f of the movable body 2 when the movable body 2 is most extended to the fixed body 1.
The PC board 51 is drawn out to the outer periphery of the fixed cylinder 1 through the hole 1c, and is connected to the printed board 54 on the main body side. In addition,
51a is the FPC board 51 at the position where the lens barrel is retracted most.
Is shown. Reference numeral 61 denotes a camera appearance shape, a decorative ring 62 is attached to the movable barrel 2, and a front tube 63 is attached to the FC sliding frame 3. Next, the basic operation of the zoom lens barrel will be described. First, when the drive motor 31 rotates, the driving force is transmitted to the fifth gear 43 through the gear trains 36, 37, 38 and 42, and the fifth gear 43 is transmitted to the drive gear 44 attached to the straight guide 21. , Tell the driving force. The driving gear 44 is the large gear 2b
The movable barrel 2 is rotated, and the movable barrel 2 which is helicoidally screwed with the fixed barrel 1 is moved in the optical axis direction. At this time, the movable barrel 2 moves forward or backward in the optical axis direction depending on the rotation direction of the drive motor 31. A rectilinear guide 21 is integrally attached to the rib 2e of the movable barrel 2 by a guide fixing plate 22, a guide fixing shaft 23, and a set screw 24. The rotation is prevented by the guide groove 1b, and only the movement in the optical axis direction is performed. Similarly, the FC sliding frame 3 is prevented from rotating in the guide groove 3b by the linear guide 21. Since the guide shaft 11 projecting from the RC sliding frame 6 penetrates the FC sliding frame 3, the RC sliding frame 6 is also prevented from rotating together with the FC sliding frame 3. Therefore, when the movable barrel 2 rotates, the FC sliding frame 3 and the movable barrel 2
The RC sliding frame 6, which is cam-coupled with the camshaft, only moves forward or backward in the optical axis direction. The FC sliding frame 3 is about 2
Move at twice the ratio. This ratio is determined by the leads of the inner helicoid and the outer helicoid of the movable body. In the embodiment, the ratios are as described above because they are set to be substantially the same. In addition, with the movement of the movable body 2, the fifth gear
The meshing position between the driving gear 44 and the driving gear 44 changes in the optical axis direction. However, since the fifth gear 43 is a gear provided with long teeth in the optical axis direction, this meshing is always maintained irrespective of the movement of the movable barrel 2. You. The rib 2e of the movable barrel 2 has a bearing surface for receiving the rotation of the movable barrel 2 in addition to preventing the thrust of the rectilinear guide 21 from coming off, thereby preventing deformation of the movable barrel 2 during transmission of driving force. I have. The RC slide frame 6 for holding the RC lens is driven by the cam groove 2d as described above, and its cam shape is changed to the focusing area so that focusing and focal length switching can be driven by the same drive source. , And a focal length switching area. Guide shaft 11 projecting from RC sliding frame 6
Penetrates the FC sliding frame 3 and holds the shaft spring 13 in a compressed state at the tip thereof with the E-shaped retaining ring 12, so that the RC sliding frame 6 is constantly urged by the spring force. Attracted in the direction. Therefore, the cam groove 2d of the movable barrel 2 uses only one side of the cam. Therefore, the width of the cam groove is larger than the width of the cam pin, and the width of the groove has a margin. The elevation angle of the cam groove 2d is set as much as possible on the side to which the force of the shaft spring 13 is applied in order to increase the operation efficiency of the cam, and the elevation angle of the cam groove is asymmetrical in front and rear so that plastic molding can be performed. In addition, the lens moves in the direction in which the spring force increases during focusing, and moves in the direction in which the spring force decreases during zoom-in. Since the cam groove 2d is open in the forward direction of the optical axis, RC
When incorporating the sliding frame 6 into the movable body 2, the sliding frame 6 is assembled from the front of the movable body 2. The RC sliding frame 6 is the FC sliding frame 3
(Including the shutter 52, etc.) via the guide shaft 11, so that the movable barrel 2 can be used as an FC / RC sliding frame unit.
When the RC sliding frame 6 is pulled toward the FC sliding frame 3 at this time, the workability of assembly is good. Further, by forming the FC sliding frame 3 so as to cover the RC sliding frame 6, it is possible to prevent the RC lens group 7 of the RC sliding frame 6 from being scratched. Usually, at the stage of the movable barrel unit including the FC / RC sliding frame unit, the lens performance such as projection resolution is inspected. However, if the movable barrel on the outer surface of the current unit is rotated, the focal length becomes longer. Because you can select and adjust the focus,
Inspection efficiency is very high and does not require large electrical tools. In this state, if the lens performance such as projection resolving power can be inspected, a defect or the like can be detected quickly, and time and cost for disassembly and repair can be saved. This unit has a shutter driver, F
Since the PC and the lens cover do not need to be incorporated, and there is no focusing mechanism, replacement of the FC lens due to a defect caused by the FC lens is easy. After the movable body unit is assembled into the fixed body 1, a rectilinear guide 21 is incorporated, and two guide fixing plates 22 for retaining rotation stoppers of the rectilinear guide 21 are incorporated.
This will be described with reference to FIGS. 3A and 3B. FIG.
In (A), in order to enhance the assembling workability, the two fixing plates 22 are linearly guided one by one by set screws 24 respectively.
After the linear guide 21 is temporarily fixed to the movable body 2 and the movable body 2 is assembled from behind the camera, the linear guide 21 is rotated clockwise around the set screw 24, and the total of the set screw 24 and the set screw 25 as shown in FIG. The linear guide 21 is screwed and connected at six locations. As described above, the straight guide 21 is composed of the fixed body 1 and the FC sliding frame 3 as a single component.
, The straightness accuracy of the FC sliding frame 3 is high, and the efficiency of the driving force for performing the straight running operation is high. The movable barrel 2 moves synchronously with the rectilinear guide 21 in the optical axis direction. A drive gear 44 is attached to the straight guide 21. Therefore, even if the movable barrel 2 moves in the optical axis direction, the position in the optical axis direction with respect to the driving gear does not change.
Has a simple shape having a tooth width only a predetermined length from the rear end face. This is to reduce the size of the large gear 2b in the optical axis direction as much as possible. As described above, according to the present invention, the rectilinear guide member that moves in the optical axis direction prevents the lens frame that also moves in the optical axis direction from rotating. on the take, Kagamido径is thin, it is possible to optical axis positional accuracy of the lens frame is realized with a simple configuration a good lens barrel, further
The first of the straight guide members arranged with the rib of the movable body interposed therebetween
Assemble both the member and the second member from the film side.
To realize a lens barrel with high assembly workability.
It is an effect that is Ru can.

[Brief description of the drawings] FIG. 1 is an exploded perspective view of a lens barrel according to the present invention. FIG. 2 is a cross-sectional view of a lens barrel. FIG. 3 is an explanatory view for assembling a guide fixing plate. FIG. 4 is a schematic diagram of a first prior art. FIG. 5 is a schematic diagram of a second prior art. FIG. 6 is a schematic diagram of a third prior art. [Explanation of symbols] 1 fixed torso 2 movable torso 3 FC sliding frame 4 FC lens frame 5 FC lens 6 RC sliding frame 7 RC lens 8 RC cam pins 11 Guide shaft 21 Straight Guide 22 Guide fixing plate 31 Lens drive motor 33 Propeller for LDP1 34 Photo interrupter for LDP1 40 Propeller for LDP2 41 Photo interrupter for LDP2 43 5th gear 44 Drive gear

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-6-208049 (JP, A) JP-A-4-42617 (JP, U) JP-A-2-19107 (JP, U) JP-A-2,107 27108 (JP, U) Japanese Utility Model Hei 5-30821 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G02B ⁷ /02-7/16 G03B 17/02-17/17

Claims (1)

(57) [Claims 1] A fixed body provided with a female helicoid and a guide groove on the inner circumference, a male helicoid screwed with the fixed body on the outer circumference, and a female helicoid provided on the inner circumference. A movable barrel provided with a rib protruding in the inner circumferential direction at an end on the film surface side, a lens frame having a male helicoid screwed to the movable barrel and a guide groove and carrying at least one group of photographing lenses; are relatively rotatable with respect to the movable body, the movable
A straight-through guide for moving the lens barrel in the optical axis direction while moving the lens barrel in the optical axis direction integrally with the movable barrel by the rotation of the barrel.
And the linear guide member is located on the object side of the second member, and is assembled to the movable barrel.
And is pivoted about a fulcrum on the second member.
Screwed to the second member with the rib of the moving body sandwiched
A first member that engages with the guide groove of the fixed barrel with the second member.
A mating portion and a second engaging portion for engaging with the guide groove of the lens frame.
Lens barrel, wherein the girder is configured.