JPH0584909U - Lens guide device - Google Patents

Abstract

(57) [Abstract] [Purpose] To obtain a lens guide device having a simple structure and easy assembling work, and to obtain a lens guide device capable of efficiently urging a cam pin and making the overall shape compact. . A lens holding frame for holding a lens group is provided with a fitting hole for supporting a cam pin so as to be capable of advancing and retreating outward in the radial direction of the lens group, and a leaf spring locking portion corresponding to the fitting hole. In a lens guide device in which a cam pin is engaged with the other end of a leaf spring whose one end is locked to the leaf spring locking portion and the cam pin is biased to project outward in the radial direction, the leaf spring has one end In a free state in which the portion is locked to the leaf spring locking portion, the other end portion is configured to be different in position from the one end portion and parallel to the optical axis of the lens group.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a lens guide device in which a cam pin fitted in a fitting hole provided in a lens holding frame for holding a lens group is urged radially outward by a leaf spring supported by the lens holding frame. ..

[0002]

[Prior art and its problems]

 This type of lens guide device is widely used for zoom lenses, etc., but in order to ensure that the cam groove and the cam pin come into contact with each other, the cam groove is an inner cam groove, and the cam pin is urged to project radially outward. Is proposed.

Conventionally, in order to urge this cam pin outward, after inserting the compression spring into the cam pin fitting hole, the cam pin is pushed in and the lens group is fitted into the cam ring while aligning the cam pin with the inner cam groove. I was out. However, this work requires skill, and if unfamiliar, the cam pin cannot be fitted properly in the inner cam groove, and the compression spring causes the cam pin to pop out and be lost. Automation was considered difficult.

[0004]

[The purpose of the device]

 An object of the present invention is to solve the conventional problems described above and to obtain a lens guide device having a simple structure and assembly work. A further object of the present invention is to obtain a lens guide device that can efficiently urge the cam pins and make the overall shape compact.

[0005]

[Outline of the device]

 The present invention that achieves the above object, therefore, has a lens holding frame for holding a lens group, a fitting hole for supporting a cam pin so as to be capable of moving forward and backward in the radial direction of the lens group, and a plate corresponding to the fitting hole. A lens guide device is provided with a spring locking portion, and a cam pin is engaged with the other end of a leaf spring having one end locked to the leaf spring locking portion to bias the cam pin to project outward in the radial direction. In the leaf spring, in the free state in which one end of the leaf spring is locked by the leaf spring locking portion, the other end is different in position from the one end and is parallel to the optical axis of the lens group. It is characterized by being configured as follows.

[0006]

【Example】

 The present invention will be described below with reference to the illustrated embodiments. First, the entire zoom lens barrel to which the present invention is applied will be described with reference to FIGS. 5 and 11.

A helicoid ring 12 is fixed to a fixed lens barrel 11 integrated with the camera body, and a female multi-thread screw 12 a of the helicoid ring 12 is attached to a male multi-thread screw 10 a formed on the outer peripheral surface of the cam ring 10. Are screwed together. A female multi-start screw 10b and an inner cam groove 10c are formed inside the cam ring 10, and a male multi-start screw 13a of the front lens barrel 13 is screwed into the female multi-start screw 10b. At the rear end of the cam ring 10, light shielding plates 25, 26 having openings 25d, 26d corresponding to the apertures of the main body of the camera are located, respectively, and are formed above the light shielding plates 25, 26. A guide portion 23b of a rectilinear guide 23 fixed to the camera body is fitted in each of the positioning recesses 25a and 26a and the positioning recess 15b of the rectilinear guide ring 15. Light-shielding plates 25 and 26 are fixed to the linear guide ring 15 with the positioning recesses 25a and 26a aligned with the positioning recess 15b, and the cam ring 10 is rotatably fitted to the linear guide ring 15. To be done. The linear guide 23 is fixed to the fixing member 24 fixed to the camera body side by a screw 22 so that the guide portion 23b is projected along the optical axis direction.

A shutter holding frame 13c having a rear end portion of an annular shutter unit 16 fixed thereto is fixed to the front lens group cylinder 13, and a helicoid ring 17 integrally provided on the inner peripheral portion of the shutter unit 16. A front lens group frame 18 that holds the front lens group is screwed into this. The shutter unit 16 has its drive pin 16a engaged with a driven pin 18a integrated with the front lens group frame 18. As is well known, the drive pin 16a is rotationally driven by an angle according to the distance measurement signal from the distance measuring device, and this rotation is transmitted to the front lens group frame 18 via the driven pin 18a, and the front lens group frame 18 ( While the front lens unit L1) rotates, it moves in the optical axis direction for focusing. The shutter unit 16 opens and closes the shutter blade 16b according to the brightness signal of the subject. In addition, 13f in FIG. 11 is a lens aperture.

As shown in FIGS. 1 to 3 and 11, the rear lens group frame 19 fitted into the cam ring 10 has a lens holding portion 19a for holding the rear lens group L2. A cam pin support leg 49 is formed so as to radially project from the rear lens group L2 in the radial direction from 19a. The cam pin support leg 49 extends vertically from the optical axis O, that is, along a radial direction, and a vertical portion 49a extending forward from the end of the vertical portion 49a in parallel with the optical axis O. , And has a parallel portion 49b which is a straight guide surface. The parallel portion 49b corresponds to the straight guide surface 15a formed on the straight guide ring 15.

Leaf spring engaging portions 53 are formed on the left and right of the front end of the parallel portion 49 b, and the left and right leaf spring engaging portions 53 are respectively formed on one end of the leaf spring 52. A dovetail groove 53a for inserting and holding the wide width portion 52g is formed. The leaf spring has an engaging notch 19d between the left and right engaging portions 53, which engages with a retaining engagement claw 52d formed at the center of the engaging wide portion 52g of the leaf spring 52. Further, a fitting hole 51 is formed in the vertical portion 49a for supporting the cam pin 50 so as to be able to advance and retreat outward in the radial direction of the rear lens group L2.

The cam pin 50 has a small diameter portion 50b slidably fitted in the fitting hole 51, a large diameter portion 50a fitted in the inner cam groove 10c formed on the inner surface of the cam ring 10, and a small diameter portion. It has a narrowed portion 50c that connects the portion 50b and the large diameter portion 50a. Further, a taper surface 50d is formed on the upper portion of the large diameter portion 50a for facilitating the fitting of the cam ring 10 into the inner cam groove 10c.

The leaf spring 52 has the locking wide portions 52g on the left and right of the one end 52a, the retaining locking claw 52d at the center of the left and right locking wide portions 52g, and the other end 52b. In addition, there is a cam pin advancing / retreating hole 52e that gradually expands rearward of the optical axis. The retaining claw 52d for slip-out prevention is formed by slightly bending downward so that it can be engaged with the engagement notch 19d. Further, a cam pin holding portion 52f having a width narrower than that of the cam pin advancing / retreating hole 52e is provided in the rearmost part of the cam pin advancing / retreating hole 52e so as to enable the narrowed portion 50c of the cam pin 50. The leaf spring 52 is connected by a connecting portion 52c in a state where one end 52a and the other end 52b are vertically offset by a predetermined amount in a side view. As a result, the leaf spring 52 is configured such that the other end portion 52b for holding the cam pin 50 is parallel to the optical axis O in the free state in which the leaf spring 52 is locked by the leaf spring locking portion 53.

When the cam pin 50 of the rear lens group frame 19 is fitted in the inner cam groove 10c on the inner surface of the cam ring 10, the rear lens group frame 19 and the shutter holding frame 13c are linearly guided by the linear guide ring 15. It is guided straight ahead by the surface 15a. FIG. 11 shows the rectilinear guide surface 15a of the rectilinear guide ring 15 and the parallel portion 49b which is the rectilinear guide surface of the rear lens group frame 19 which are engaged with each other.

Therefore, the work for assembling the cam pins 50 on the three vertical portions 49a is performed as follows. First, the cam pin 50 is inserted into the cam pin advancing / retreating hole 52e of the leaf spring 52 from the small diameter portion 50b, and the cam pin 50 is fitted into the fitting hole 51 while the leaf spring 52 is playing with the cam pin 50. After this fitting, the wide locking portion 52g is slid into the dovetail groove 53a until the contact portion 52h at the rear end of the wide locking portion 52g contacts the rear end portion of the leaf spring locking portion 53. The shape of the retaining pawl 52d for removal is restored and engages with the engagement notch 19d. As a result, the leaf spring 52 is supported without coming off the leaf spring locking portion 53. At the same time, in the other end portion 52b of the leaf spring 52, the cam pin advance / retreat hole 52e moves forward along the lower end surface of the large diameter portion 50a along the optical axis, so that the cam pin holding portion 52f engages with the cut portion 50c. As a result, the cam pin 50 is held by the cam pin holding portion 52f at the cutout portion 50c, is prevented from coming off the fitting hole 51, and is biased to project outward in the radial direction of the rear lens group frame 19.

By the same operation as above, the cam pins 50 are attached to the three vertical portions 49a. Then, the rear lens group frame 19 is fitted on the cam ring 10. In this case, since the cam pin 50 does not come off even if it is not particularly pressed, a jig or the like is required for the assembling work to the cam ring 10. do not do. At the time of assembly, the front lens group cylinder 13 is inserted into the cam ring 10 with the recess 13b of the front lens group cylinder 13 formed corresponding to the three cam pins 50 being engaged with each cam pin 50. At this time, as shown in FIG. 2, the cam pin 50 has the taper surface 50d along the front end portion 10e of the cam ring 10 and is smoothly pushed into the inner cam groove 10c. It is pushed into the inner cam groove 10c. When the cam pin 50 is pushed into the fitting hole 51 against the urging force of the leaf spring 52, as shown by the chain double-dashed line in FIG. 3, the rear end 52i of the other end 52b is connected to the upper surface of the vertical portion 49a. Since the other end portion 52b is further deformed in the state of being pressed against the plate spring 52, the biasing force of the leaf spring 52 is strengthened, and even if the cam pin 50 is pushed by a strong force, the leaf spring 52 is not plastically deformed. Then, each cam pin 50 is engaged with each inner cam groove 10c without backlash. After the assembling, the front group lens barrel 13 follows the multiple threads 10b and 13a, and the rear group lens frame 19 follows the cam groove 10c by the rotation of the cam ring 10, independently moving in the optical axis direction.

As described above, in the leaf spring 52, the other end 52b is held parallel to the optical axis O in the free state in which the one end 52a is locked by the plate spring locking portion 53, and at the same time, the cam pin is held. The cam pin 50 can be urged to project outward in the radial direction by the other end portion 52 b holding 50. Therefore, as compared with a leaf spring in which the other end portion 52b is not parallel to the optical axis O but is simply tilted upward, the cam pin 50 is more efficient than the other end portion 52b which is parallel to the lower end surface thereof. It can be well biased and the overall shape can be made compact.

In the zoom lens barrel having the above configuration, when the cam ring 10 is rotationally driven, the cam ring 10 itself moves in the optical axis direction in accordance with the relationship between the male multi-thread screw 10a and the female multi-thread screw 12a. At the same time, the front group lens barrel 13 (front group lens L1) is moved in the optical axis direction by the screwing relationship between the female multi-thread screw 10b and the male multi-thread screw 13a and the linear guide mechanism of the shutter holding frame 13c and the linear guide ring 15. Go straight to. When the cam ring 10 rotates, the inner cam groove 10c on the inner surface of the cam ring 10 and the cam pin 50 provided on the rear lens group frame 19 and the rectilinear guide mechanism of the rear lens group frame 19 and the rectilinear guide ring 15 cause a rearward movement of the cam ring 50. The group lens frame 19 (rear group lens L2) moves in the optical axis direction for zooming.

The cam ring 10 has a male multi-thread screw 10a and a plurality of threads of gears 10d parallel to each other, which are located at the rear portion of the cam ring 10. The gear 10d is composed of a spur gear whose teeth are parallel to the axis of the cam ring 10, is inclined in the same direction as the direction of the ridges of the male multi-thread screw 10a, and between the gears 10d, A single thread ridge 10a 'is formed on the male multi-thread screw 10a. In other words, the male multi-thread screw 10a is cut off at a part of its circumferential direction except for one thread 10a ', and the cut portion is provided with a gear 10d. In this embodiment, the multi-start screw 10a is a triple-start screw, and the gear 10d is provided at the cut-off portion of the double-start screw. The axially formed lengths s of the male multi-thread screw 10a, the single thread 10a 'and the gear 10d are the same.

On the inner surface of the helicoid ring 12, a female multi-thread screw 12a and a clearance groove (not shown) corresponding to the male multi-thread screw 10a of the cam ring 10, the single thread 10a 'and the triple gear 10d, respectively. Etc. are formed. That is, the gear 10d moves without contact in the clearance groove when the cam ring 10 rotates in accordance with the engagement of the male multi-thread screw 10a (thread 10a ') and the female multi-thread screw 12a.

Further, the helicoid ring 12 has a notch 12d on its side surface, and a pinion (not shown) located in the notch 12d is meshed with the gear 10d. This pinion has an axial length that allows it to mesh with the three gears 10d at the same time, but at the front and rear moving ends of the cam ring 10, only the rearmost and frontmost gears 10d, respectively. Mesh with. The pinion is located at a fixed position in the cutout 12d and is rotationally driven by a drive motor (not shown).

Next, the adjusting device used in the zoom lens barrel of the present embodiment will be described. This adjusting device includes the zoom mechanism that is zoomed by the rotation of the rotationally driven cam ring 10 and the zoom code plate provided on the inner surface of the front lens barrel 13 that moves straight in the optical axis direction by the zoom mechanism. 36, a brush support member 40 having a zoom brush 41 that contacts the zoom code plate 36 to detect the current focal length, and a brush position adjustment mechanism that adjusts the position of the brush support member 40 in the optical axis direction. It is equipped.

As shown in FIG. 9, pattern contacts are formed on the zoom code plate 36, and during zooming, the zoom code plate 36 advances and retreats in the optical axis direction together with the front lens barrel 13 to zoom in and out. Since the position of the brush 41 is changed, a digital signal corresponding to the current focal length is output to the camera operation control circuit (not shown) based on this position. Based on this focal length signal, data corresponding to the focal length at that time is input to the camera operation control circuit from the data table prepared for each variable information.

An insertion groove 13e is formed in a part of the inner peripheral surface of the front lens barrel 13 in parallel with the optical axis O. One end of the zoom code plate 36 is located on the side of the insertion groove 13e near the photographing opening 13f. An engagement protrusion 13d for engaging the positioning hole 36a formed in the portion is formed. The position of the zoom code plate 36 is determined in parallel with the optical axis direction by engaging the positioning hole 36a with the engaging protrusion 13d, and the back surface thereof is fixed by being stuck to the insertion groove 13e.

As shown in FIG. 10, the brush support member 40 is made of a synthetic resin material formed in an inverted L shape in a side view, and is in contact with a support portion 15 c formed in a part of the rectilinear guide ring 15. It has a contact portion 40b to be positioned and a positioning portion 40c for positioning and supporting the four zoom brushes 41 corresponding to the pattern contacts of the zoom code plate 36. The support portion 15c has an insertion hole 33 into which the mounting screw 31 is inserted, and the contact portion 40b has a female screw hole 40a corresponding to the insertion hole 33. Further, the zoom brush 41 has an output side terminal 41a at one end which should come into contact with the terminal 37a of the flexible substrate 37 when the brush supporting member 40 is mounted on the supporting portion 15c by the mounting screw 31. The other end has an input-side terminal 41b that is in sliding contact with 36.

A spring insertion hole 32 is formed in the support portion 15c so as to be adjacent to the screw insertion hole 33 and penetrates toward the contact portion 40b similarly to the screw insertion hole 33. In the spring insertion hole 32, the separating spring 30 whose one end is in contact with the brush supporting member 40 and the other end is in contact with the light shielding plate 26 is contracted, so that the brush supporting member 40 is supported by the supporting portion 15c. In the state of being supported by the support portion 15c, the support portion 15c is biased in a direction away from the support portion 15c. Accordingly, when the mounting screw 31 is rotated in an appropriate direction and tightened or loosened in a state in which the brush supporting member 40 is supported by the supporting portion 15c, the brush supporting member is caused to respond to the rotation amount of the mounting screw 31. 40, that is, the input side terminal 41b can be slid with respect to the zoom code plate 36. Therefore, by the separating spring 30 for urging the brush supporting member 40 in the direction of separating from the supporting portion 15c, and the mounting screw 31 for supporting the brush supporting member 40 on the supporting portion 15c against the separating spring 30. A brush position adjustment mechanism is configured.

On the other hand, as shown in FIG. 6, a sliding groove 38 for accommodating the brush supporting member 40 and the zoom brush 41 is formed in one of the three rectilinear guide surfaces 15a having the supporting portion 15c. Has been done. The sliding groove 38 is formed to have substantially the same size as the width of the brush supporting member 40, and a regulation wall 39 is formed in the substantially central portion thereof. A flat surface 15e is formed on the outer side of the support portion 15c. The terminal 37a of the flexible substrate 37 is placed on the flat surface 15e, and the output side terminal 41a of the zoom brush 41 is placed on the terminal 37a. Is pressed. When the zoom brush 41 is mounted in the sliding groove 38, first, the output side terminal 41a is inserted into the flat surface 15e side, the brush supporting member 40 is fitted in the sliding groove 38, and further the input side terminal 41b of the zoom brush 41 is provided. Is brought into contact with the back surface of the regulation wall 39. At this time, the terminal 37a is sandwiched between the output side terminal 41a and the flat surface 15e. As a result, the zoom brush 41 is connected to the flexible board 37 that is connected to the camera operation control side.

As shown in FIG. 11, guide holes 15d are formed on the left and right of the support portion 15c of the straight guide ring 15, and the guide holes 15d are formed on the left and right sides of the brush support member 40. By inserting the guide protrusion 40d slidably, the input side terminal 41b can be slid very smoothly with respect to the zoom code plate 36 without being displaced.

[0028]

[Effect of the device]

 As described above, according to the lens guide device of the present invention, the work of assembling the lens holding frame to the cam ring can be easily performed without using a special jig or the like. Since it can be prevented from coming off and elastically supported by the leaf spring, the number of parts can be reduced, the structure of the device can be simplified, and automatic assembly is possible. Further, the leaf spring is configured such that, in a free state in which one end of the leaf spring is locked by the leaf spring locking portion, the other end is parallel to the optical axis of the lens group, so that the cam pin is efficiently urged. In addition, the overall shape can be made compact.

[Brief description of drawings]

FIG. 1 is a perspective view showing a main part of a lens guide device according to the present invention.

FIG. 2 is a side view showing a main part of the lens guiding device of FIG.

FIG. 3 is a side view showing a position change of a cam pin when the rear lens group frame is fitted into the cam ring.

FIG. 4 is an enlarged sectional view showing an engaged state of a cam pin with respect to the cam groove of FIG.

FIG. 5 is a cross-sectional view showing an example of a zoom lens barrel to which a rotary feeding mechanism can be applied.

FIG. 6 is an exploded perspective view showing a state in which a cam ring is removed from the adjusting device.

FIG. 7 is a perspective view showing a zoom code plate arrangement structure on the inner surface of the front lens barrel.

8 is a view of the main part of FIG. 7 viewed from above.

FIG. 9 is a diagram showing a zoom code plate alone.

FIG. 10 is a side cross-sectional view showing a zoom code plate, a zoom brush, and a position adjusting mechanism for adjusting the positions thereof.

FIG. 11 is an exploded perspective view of a main part of a zoom lens barrel.

[Explanation of symbols]

 10 cam ring 10c inner cam groove 11 fixed lens barrel 12 17 helicoid ring 13 front group lens barrel 15 straight guide ring 19 rear group lens frame (lens holding frame) 19a lens holding portion 19d engaging notch 23 straight guide 49 cam pin support leg 49a vertical Portion 49b Parallel portion 50 Cam pin 50a Large diameter portion 50b Small diameter portion 50c Constriction portion 50d Tapered surface 51 Fitting hole 52 Leaf spring 52a One end portion 52b Other end portion 52c Connecting portion 52d Locking claw 52e Cam pin advance / retreat hole 52f Cam pin holding Part 52g Wide locking part 53 Leaf spring locking part 53a Dovetail groove L2 Rear group lens L1 Front group lens

Claims (1)

[Scope of utility model registration request] 1. A lens holding frame for holding a lens group is provided with a fitting hole for supporting a cam pin so as to be able to move forward and backward in the radial direction of the lens group, and a leaf spring locking portion corresponding to the fitting hole. ,
In a lens guide device for engaging a cam pin with the other end of a leaf spring whose one end is engaged with the leaf spring engaging portion and forcing the cam pin to project outward in the radial direction, the leaf spring is In a free state in which one end is locked to the leaf spring locking part, the other end is configured so that its position is different from that of the one end and is parallel to the optical axis of the lens group. Lens guide device.