JP3300605B2 - Linear guide mechanism for lens barrel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rectilinear guide mechanism for a lens barrel, and more particularly, to a rectilinear guide mechanism capable of achieving downsizing of a lens barrel while maintaining a predetermined strength.

[0002]

2. Description of the Related Art Conventionally, in joining members using a key and a key groove, first, a key width and a radial height (amount of engagement with the key groove) which are sufficient in strength are set. The dimensions of the peripheral members are determined from. Therefore, the so-called strength member tends to be large.

If the above-described design method is followed for a product (for example, a camera) for which downsizing is an essential requirement, it is extremely difficult to meet the demand for downsizing while maintaining a predetermined strength.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a linear guide mechanism for a lens barrel which can reduce the size of the apparatus while maintaining a predetermined strength based on the above-mentioned problem awareness.

[0005]

SUMMARY OF THE INVENTION A lens according to the present invention for achieving the above object.
The linear guide mechanism of the zoom lens barrel includes an outer cylinder having a linear guide groove parallel to the optical axis on an inner peripheral surface ; a linear member having a radial projection fitted in the linear guide groove, and fitted in the outer cylinder. When; in linear guide mechanism of a lens barrel having, a bottom surface of the rectilinear guide grooves, substantially perpendicular to the plane and without the radial direction, out of the outer cylinder
A notch surface parallel to the bottom surface of the rectilinear guide groove is formed on the peripheral surface , and the distance from the notch surface to the optical axis is outside the outer cylinder.
From above the outer peripheral surface portion where the notched surface is not formed
It is characterized by being shorter than the distance to the optical axis .

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on illustrated embodiments. In this embodiment, the present invention is applied to the lens shutter type zoom lens camera shown in FIG. 13. First, the concept of the zoom lens camera will be described with reference to FIG. The lens configuration is the front group lens L
1 and a rear lens unit L2.

[0007] The camera body includes an overall movement motor control means 60, a rear group movement motor control means 61, and a zoom operation means 6.
2, shutter release means 63, distance measuring device 64, photometric device 65, and AE motor control means 66 are provided.

When the zoom operating means 62 such as a zoom lever provided on the camera body is operated, the whole moving motor control means 60 controls the whole moving motor 25 by a zoom lens comprising a front lens group L1 and a rear lens group L2. A command for moving the camera from the wide side to the tele side, or a command for moving the camera from the tele side to the wide side. The focal length is changed by the operation of the zoom operation unit 62 by the photographer, and is set to an arbitrary focal length. The image magnification of the finder field is changed in conjunction with the focal length change by the zoom operation means 62. Therefore, the photographer can know the change in the focal length due to the operation of the zoom operation unit 62 by observing the change in the image magnification of the finder field. The focal length set by the operation of the zoom operation unit 62 can be recognized by, for example, a numerical value displayed on an LCD display panel (not shown).

When the shutter release means 63 is operated, the whole-group moving motor control means 60 is driven by the rear-group moving motor control means 61.
At the same time, the overall movement motor 25 is driven to focus the zoom lens on the subject. The shutter release means 63
The shutter button is constituted by a release button. When the shutter button is depressed one step, a distance measurement command to the distance measurement device 64 and a photometry command to the photometry device 65 are given. Then, the shutter 27 of the AF / AE shutter unit 21 is operated. The shutter 27 receives the photometric output from the photometric device 65 and opens its shutter blade 27a for a predetermined time.

When operated, the zoom operation means 62 drives the whole movement motor 25 to move the front lens group L1 and the rear lens group L2 integrally. At the same time as this movement, the rear group moving motor 30 may be operated via the rear group moving motor control means 61. However, the important point of this zoom lens camera is that the front group lens L1 and the rear group lens The movement of L2 is not performed by the conventional zooming concept of continuously changing the focal length without moving the focal point position. That is, when the zoom operation means 62 is operated, only the whole movement motor 25 is operated, and the front group lens L
1 and the rear group lens L2 are moved back and forth without changing the air gap between them, and the front group lens L1 and the rear group lens L2 are operated by operating both the overall movement motor 25 and the rear group movement motor 30. Is moved while changing the air gap between the two.

In the embodiment of the present invention, it is impossible that a subject at a specific distance is always in focus. However, in a lens shutter type camera such as this camera which does not observe an image taken by a photographing optical system, the focus is set at the time of shutter release. There is no problem at all if it fits. In the aspect, the front lens group L1 and the rear lens group L2 are moved while allowing the focal position to move, and both the entire moving motor 25 and the rear group moving motor 30 are operated during the shutter release to focus. .

After executing any one of the above-described control modes in response to the operation of the zoom operation means 62, the shutter release means 63 is operated in at least a part of the focal length range of the focal length set by the zoom operation means 62. When this is done, the whole moving motor 25 and the rear group moving motor 30
Are operated to focus on the subject. The amount of movement of the front group lens L1 and the rear group lens L2 by the entire movement motor 25 and the rear group movement motor 30 at this time is not limited to the amount of movement obtained by subject distance information by the distance measuring device 64,
It is determined in consideration of the amount of movement obtained by the focal length information set by the zoom operation means 62. As described above, when the shutter release means 63 is operated and both the overall movement motor 25 and the rear group movement motor 30 are operated to perform the focusing operation, the degree of freedom in controlling the lens position is increased, and the control thereof is performed. Becomes easier.

Note that, theoretically, when the zoom operating means 62 is operated, the entire moving motor 25 and the rear group moving motor 30 are moved.
Without operating any of them, only the view magnification of the finder and the focal length information are changed, and the shutter release means 63
Is operated, the focal length information and the distance measuring device 64
, The front and rear group lenses L1 and L2 are moved to the positions uniquely determined by the focal length information and the subject distance information. It can also be done.

Next, an embodiment in which the zoom lens barrel having the above concept is concretely described mainly with reference to FIGS. 11 and 12. FIG. First, the schematic configuration and operation of the zoom lens barrel 10 will be described.
A movable lens barrel 19, a third movable lens barrel 16, and a fixed lens barrel block 12 are provided. The third movable lens barrel 16 is screwed to the cylindrical portion of the fixed lens barrel block 12, and moves forward and backward in the optical axis direction with rotation. The third movable lens barrel 16 has a rectilinear guide cylinder 17 whose rotation is regulated and moves inward in the optical axis direction, and the second movable lens barrel 19 rotates relative to the rectilinear guide cylinder 17. While moving back and forth in the optical axis direction. First movable lens barrel 2
In the case of 0, the rotation is restricted, and moves in the optical axis direction by the relative rotation with respect to the second movable lens barrel 19. The entire moving motor 25 is fixed to the fixed lens barrel block 12 and has an AE motor 29 and a rear group moving motor 30 mounted thereon.
0 is fixed to the first movable lens barrel 20. The front group lens L1 is a lens having a positive power supported by the lens support cylinder 34, and the rear group lens L2 is a lens support cylinder 5
This is a lens having negative power supported by zero.

The fixed lens barrel block 12 fixed in front of the aperture plate 14 of the camera body has a female helicoid 12a, a plurality of rectilinear guide grooves 12b parallel to the optical axis O, on the inner peripheral surface of the cylindrical portion. have. An engagement protrusion 17c '(see FIGS. 11 and 12) formed on the straight guide cylinder 17 is slidably engaged with one of the plurality of straight guide grooves 12b. The straight guide groove 1 with which the engaging projection 17c 'is engaged.
A code plate 13 having a predetermined pattern is provided at the bottom of 2b.
a is fixed. The code plate 13 a is configured as a part of the flexible printed circuit board 13 located outside the fixed lens barrel block 12. Aperture plate 14
Is an aperture 14a for determining an exposure area on the film.
Having.

On the inner periphery of the cylindrical portion of the fixed lens barrel block 12,
Gear housing 1 bulging radially outward and extending in the optical axis direction
2c is formed (see FIG. 7). This gear storage unit 1
A drive pinion 15 long in the optical axis direction is rotatably housed in 2c. The drive pinion 15 has both ends of the shaft 7 rotatably supported by a support hole 4 provided in the fixed lens barrel block 12 and a support hole 31 a provided in the gear support plate 31. The tooth surface of the drive pinion 15 projects from the inner peripheral surface of the fixed lens barrel block 12.

A third movable barrel 16 is screwed into the inner periphery of the fixed barrel block 12. This third movable lens barrel 16
Has a plurality of linear guide grooves 16 extending in the optical axis direction on the inner peripheral surface.
and a male helicoid 16a that meshes with the female helicoid 12a of the fixed lens barrel block 12 and an outer peripheral gear 16b (see FIG. 6) that meshes with the drive pinion 15 on the outer periphery of the rear end portion. The drive pinion 15 includes a third movable lens barrel 16.
Has an axial length that meshes with the outer peripheral gear 16 in the entire moving range in the optical axis direction.

A linear guide tube 17 is supported on the inner periphery of the third movable lens barrel 16 so as to be integrally movable with the third movable lens barrel 16 in the optical axis direction and relatively rotatable around the optical axis. . The rectilinear guide cylinder 17 includes a rear end flange portion 17d having a plurality of engagement protrusions 17c protruding radially outward on the rear outer periphery,
A retaining flange 1 having a smaller diameter than the flange 17d, which is provided with a slight gap in front of the rear end flange 17d.
7e. A plurality of notches 17f are formed in the circumferential direction of the retaining flange 17e. The third movable lens barrel 16 has a plurality of engaging projections 16d (FIG. 11) protruding radially inward on the inner periphery of the rear end.
d is inserted through the notch 17f so that both flanges 17
It is located in the gap between d and 17e, and is connected to the rectilinear guide tube 17 by rotating relative to the rectilinear guide tube 17. An aperture plate 23 having an opening 23a having substantially the same shape as the aperture 14a is fixed to a rear end surface of the straight guide cylinder 17. The engagement protrusion 17c is slidably engaged with a straight guide groove 12b parallel to the optical axis O of the fixed lens barrel block 12, and its rotation is restricted. The contact terminal 9 for slidingly contacting the code plate 13a and generating a signal corresponding to the focal length during zooming is fixed to the engagement protrusion 17c ', which is one of the engagement protrusions 17c.

The straight guide cylinder 17 also has an inner peripheral surface
A plurality of rectilinear guide grooves 17a parallel to the optical axis O and a plurality of lead grooves 17b penetrating the peripheral wall of the guide cylinder 17 and inclined with respect to the circumferential direction and the optical axis direction are formed.

A second movable lens barrel 19 is fitted on the inner circumference of the straight guide cylinder 17. The second movable lens barrel 19 has a plurality of lead grooves 19 that are inclined on the inner peripheral surface in a direction opposite to the lead grooves 17b.
and a plurality of follower projections 19a having a trapezoidal cross section protruding outward in the radial direction and a follower pin 18 located on the follower projection 19a. The follower pin 18 includes a ring member 18a and a center fixing screw 18b that supports the ring member 18a on a follower projection 19a. The follower projection 19a
Slidably fitted in the lead groove 17b of the straight guide cylinder 17,
The follower pin 18 is provided in the straight guide groove 1 of the third movable lens barrel 16.
6c slidably fits. Therefore, when the third movable lens barrel 16 rotates, the second movable lens barrel 19 rotates and moves straight in the optical axis direction.

A first movable lens barrel 20 is fitted on the inner periphery of the second movable lens barrel 19. The first movable lens barrel 20 engages a plurality of follower pins 24 provided on the outer periphery of a rear end portion with a corresponding inner peripheral lead groove 19c, and a linear guide member 22.
Is guided straight ahead. This straight guide member 22 is
As shown in FIGS. 1 and 2, an annular portion 22a, a pair of guide legs 22b extending from the annular portion 22a in the optical axis direction,
The linear guide groove 1 protrudes radially outward of the annular portion 22a.
A guide leg portion 22b is inserted between the inner peripheral surface of the first movable lens barrel 20 and the AF / AE shutter unit 21 so as to be capable of linearly guiding. are doing.

The annular portion 22a of the straight guide member 22
The second movable lens barrel 19 is coupled to the rear end portion so as to be integrally movable in the optical axis direction and relatively rotatable around the optical axis. The rectilinear guide member 22 has a rear end flange portion 22d having a plurality of engagement protrusions 28 protruding radially outward on a rear outer periphery.
And a retaining flange portion 22c smaller in diameter than the flange portion 22d, provided with a slight gap in front of the rear end flange portion 22d, and a plurality of notches 22e in the circumferential direction of the retaining flange portion 22c. (See FIGS. 1 and 2). The second movable lens barrel 19 has a plurality of engagement projections 19b (see FIGS. 11 and 16; only one is shown in each figure) protruding radially inward on the inner periphery of the rear end portion. The engagement projection 19b is inserted from the notch 22e and positioned in the gap between the two flanges 22c and 22d.
Relative to the straight guide member 22. With the above configuration, when the second movable barrel 19 rotates in the forward and reverse directions, the first movable barrel 20 moves straight forward and backward with respect to the second movable barrel 19 in the optical axis direction while the rotation is restricted. I do.

At the front end of the first movable lens barrel 20, a barrier device 35 having barriers 48a and 48b is mounted.
An AF / AE shutter unit 2 having a shutter 27 including three shutter blades 27a (FIG. 5) on the inner peripheral surface.
1 is fitted and fixed. The AF / AE shutter unit 21 has a plurality of fixing holes 40a (FIG. 3) formed at equal angular intervals on the outer periphery of the shutter mount 40.
The plurality of follower pins 24 also serve as fixing means for the AF / AE shutter unit 21, and are provided in a pin hole 20 a formed in the first movable lens barrel 20 and the fixing hole 40 a.
The follower pin 24 is fitted and fixed, and the shutter unit 21 is fixed to the first movable lens barrel 20 (see FIG. 4). The follower pin 24 can be fixed by, for example, bonding, screwing, or the like. 41 is the first movable lens barrel 20
This is a decorative plate that is fixed to the front end of the display.

The AF / AE shutter unit 21 is shown in FIG.
12, a shutter mount 40, a shutter blade support ring 46 fixed to the rear of the shutter mount 40, and a lens support movably supported with respect to the shutter mount 40. Tube 50 (rear group lens L
2). The front lens L1, the AE motor 29, and the rear group moving motor 30 are supported by the shutter mount 40. The shutter mount 40 has an annular portion having a shooting opening 40d through which the lens support tube 34 is inserted, and three legs 40b extending rearward from the annular portion. Two of the gaps between the three legs 40b are a pair of guide legs 2 of the straight guide member 22.
2b is configured as a rectilinear guide portion 40c which slidably engages and guides the movement.

The shutter mount 40 further includes an AE gear train 45 for transmitting the rotation of the AE motor 29 to the shutter 27.
And the rotation of the rear group moving motor 30 with the screw shaft 4
3 and the photo interrupters 56 and 57 connected to the flexible printed circuit board 6.
Rotating plates 58, 5 having a number of circumferential slits
9 are supported. The photointerrupter 57 and the rotating plate 59 constitute a rear group moving motor encoder for detecting the rotation of the rear group moving motor 30, and the AE motor 29 is formed by the photointerrupter 56 and the rotating plate 58.
An AE motor encoder that detects the rotation of the motor is configured.

Between the shutter mount 40 and the shutter blade support ring 46 fixed to the mount 40, the shutter 2
7, a support member 47 for pivotally supporting the three shutter blades 27a of the shutter 27, and an annular driving member 49 for applying a rotational power to the shutter blades 27a. The annular driving member 49 includes three operation protrusions 49a respectively engaging with the three shutter blades 27a at equal angular intervals. The shutter blade support ring 46 is provided at the front wall with the photographing opening 4.
6a and three support holes 46b provided at equal angular intervals around the photographing opening 46a.
It has a flexure restricting surface 46c that is exposed from 0c and slidably supports the inner peripheral surfaces of the pair of guide legs 22b (see FIGS. 9 and 10).

A support member 47 located in front of the shutter blade support ring 46 includes a photographing opening 47a facing the photographing opening 46a, and three shaft portions 47b (see FIG. 5) facing the three support holes 46b, respectively. (Only parts are shown). Each of the three shutter blades 27a has, at one end, a shaft hole 27b through which the shaft 47b is inserted, and at the other end, a shielding portion that shields the imaging openings 46a, 47a.
An elongated hole 27c is provided between the one end and the other end to allow the operation projection 49a to pass therethrough. The support member 47 includes a shaft portion 47b supporting the shutter blade 27a.
The shutter blade support ring 46 is fixed to the shutter blade support ring 46 in a state of being fitted into the corresponding support hole 46b.

The annular driving member 49 has a gear train 4 on its outer periphery.
5 has a gear portion 49b for receiving rotation from. The support member 47 has three arc grooves 47c in the circumferential direction at positions close to the three shaft portions 47b. The three operation projections 49a of the annular driving member 49 penetrate through the three arc grooves 47c, and the long holes 27 of the respective shutter blades 27a.
c. The shutter blade support ring 46 is inserted from the rear side of the shutter mount 40 while supporting the annular driving member 49, the support member 47, and the shutter 27, and is screwed to the shutter mount 40.

Behind the shutter blade support ring 46, there is disposed a lens support cylinder 50 supported on the shutter mount 40 via slide shafts 51 and 52 so as to be relatively movable. The shutter mount 40 and the lens support cylinder 50 are urged to move in the direction away from each other by the coil spring 3 fitted to the slide shaft 51, thereby eliminating play between them. The drive gear 42a provided in the gear train 42 is restricted from moving in the axial direction, and a female screw is formed on the inner periphery thereof. A screw shaft 43 having one end fixed to the lens support cylinder 50 is screwed to the female screw.
And the screw shaft 43 constitute a feed screw mechanism. Therefore, when the rear group moving motor 30 is driven to rotate and the drive gear 42a rotates forward or backward, the screw shaft 43 advances and retreats with respect to the drive gear 42a, and is supported by the lens support tube 50, that is, the support tube 50. The rear lens group L2 moves relative to the front lens group L1.

At the front of the shutter mount 40, holding members 53, 55 for holding the motors 29, 30 and the like supported by the shutter mount 40 are screwed. The motors 29 and 30 and the photo interrupters 56 and 57 are connected to the flexible printed circuit board 6 having one end fixed to the shutter mount 40. In a state where the first to third movable lens barrels 20, 19, 16 and the AF / AE shutter unit 21 and the like are assembled, an aperture plate 23 is fixed to the rear end face of the straight guide cylinder 17, and the front end of the fixed lens barrel block 12. An annular retaining member 33 is fitted to the portion.

In the present embodiment, the front lens group L1 and the rear lens group L2 are respectively connected to the AF / AE shutter unit 21.
The AE motor 29 and the rear group moving motor 30 are mounted on the unit 21. According to this configuration, there is an advantage that the supporting structure and the driving structure of the front lens unit L1 and the rear lens unit L2 can be simplified, but at least one of the front lens unit L1 and the rear lens unit L2 is
Shutter mount 40, annular drive member 49, support member 4
7, the zoom lens is realized even if the AF / AE shutter unit 21 including the shutter 27 and the shutter blade holding ring 46 is provided as a separate member and is supported by a support member different from the unit.

Next, an example in which the present invention is applied to the fixed lens barrel block 12 and the straight guide cylinder 17 will be described with reference to FIGS. Specifically, the fixed barrel block 12 shown in the perspective view of the fixed barrel block of the zoom lens barrel shown in FIG.
The linear guide groove 12bi, which is one of a plurality of linear guide grooves 12b formed in parallel with the optical axis O, and the engagement projection 17ci, which is one of the plurality of engagement projections 17c, which engages with this. Apply the invention. The rear view of the fixed lens barrel block in FIG. 15 shows an engagement state between the straight guide groove 12bi and the engagement projection 17ci. The engaging projection 17ci is formed in a substantially M-shaped cross section, and the engaging projection 17ci is a projection 1 forming a part of the female helicoid 12a even when the linear guide tube 17 advances and retreats.
It does not abut on 2a '. This projection 12
14A and 18A, the female helicoid 12a is cut off on both sides in the width direction of the linear guide groove 12bi to be discontinuous, and at the center in the width direction of the linear guide groove 12bi, as clearly shown in FIGS. , Formed as projections. Further, FIG. 16 shows the linear guide groove 12bi and the engagement protrusion 17ci.
FIG. 4 is a side sectional view showing an engaged state of FIG.

FIGS. 17 and 18 show the fixed lens barrel block 1.
FIG. 4 is an enlarged cross-sectional view and a plan view showing an engagement state between 2 and a linear guide cylinder 17. FIG. 17 shows a straight guide groove 1 which is one of the straight guide grooves 12b to which the present invention is not applied for comparison.
2bn i and the engagement protrusion 17 which is one of the engagement protrusions 17c.
cni.

The engagement protrusion 17ci has a length t '(amount) from the bottom of the female helicoid 12a and the straight guide groove 12bi.
And has reached the vicinity of the bottom of the housing. The width (key width) of the engagement protrusion 17ci at this time is W ′. Note that FIG.
X1 and X1 shown below indicate the corners of the engagement projection 17ci, and the line segment X1-X1 means the key width W 'corresponding to the groove width of the straight guide groove.

On the other hand, the rectilinear guide groove 12bni reaches and engages near the bottom of the rectilinear guide groove 12bni with a length t (amount) from the bottom of the female helicoid 12a. The width (key width) of the engagement protrusion 17cni at this time is W. The engaging projections 17ci are basically the engaging projections 17cn.
It is assumed that the female helicoid 12a has a strength substantially equal to i and a length (amount) (t ′, t) from the valley bottom of the female helicoid 12a. In addition, X2 and X2 shown in FIG. 17 indicate the corners of the engagement projection 17cni, and the line segment X2-X2 means the key width W corresponding to the groove width of the straight guide groove. And female helicoid 12
Since the lengths (amounts) (t ', t) of the a from the valley bottom are substantially the same, (X1, X1) and (X2, X2) can be considered to be on the same circumference, and there is no problem in practice. In other words, FIG.
7, X1, X1 and the optical axis O, X2, X2 and the optical axis O
Are two isosceles triangles sharing a virtual circumscribed circle CC. Therefore, the corresponding straight guide grooves 12bi, 12b
Both the bottoms of ni are planes orthogonal to the radial direction. In addition, although a circle drawn by the corner of the straight guide groove is formed slightly outward in the radial direction from the corner of these engagement protrusions,
Since the tip of the engagement projection is provided with an amount of protrusion reaching the vicinity of the bottom of the straight guide groove, it is theoretically concentric, but
Since the difference is small, the embodiment according to the present invention will be described focusing on the engagement protrusion.

It is a feature of the present invention that a portion corresponding to the linear guide groove 12bi on the outer peripheral surface of the fixed lens barrel block 12 can be formed in parallel with the bottom of the linear guide groove 12bi while maintaining the above conditions . This will be described below. Although the rectilinear guide cylinder 17 does not rotate itself, the rotation of the third movable barrel 16 transmits its rotational force from the male helicoid 16a to the female helicoid 12a, and the shearing force is received by the plurality of engagement projections 17c. . Female helicoid 12a
If the length from the valley bottom (hung amount) (t't) and the key width W are set to values sufficient to receive the shearing force, there is no problem with the shearing force even if the key width is increased.

As schematically shown in FIG. 19, when the key width X1-X1 (the bottom side of the triangle) is increased,
The intersection with the circumscribed circle CC approaches the optical axis O (the center of the circumscribed circle). That is, the line segment X1-X1 is closer to the optical axis O (center of the circle) than the line segment X2-X2, and if the bottom of the straight guide groove is provided near the tip of the engagement protrusion as described above, this portion The thickness of the fixed lens barrel block 12 is larger than that of the straight guide groove 12bni. For example, in this case, the distance from the outer surface of the fixed lens barrel block 12 to the tip of each engagement protrusion is L1,
Assuming that L2, the difference (L1-L2 = y) in FIG.
Vertical direction (line segment X1-X1 or line segment X2-X from optical axis O)
2 perpendicular direction) and the thickness of the fixed barrel block 12
And the outer surface of this thickened part
Even if it is cut out and formed as a flat surface,
The same wall thickness as the other parts of the buckle 12 can be secured.

Therefore, as shown in FIG.
By removing the outer surface of the fixed lens barrel block 12 by this relatively thick amount (length y) and providing a portion 12x (flat surface) cut out parallel to the bottom of the straight guide groove 12bi, the fixed lens barrel is provided. The block 12 can be reduced in size.

Then, as shown in FIG. 21, when the flat surface PT1 of the patrone storage structure PT is arranged adjacent to the flat surface 12x of the fixed lens barrel block 12, the patrone chamber can be brought closer to the center of the camera. The size can be reduced. The distance H from the center (optical axis O) of the fixed lens barrel block 12 obtained by providing the flat surface 12x to the flat surface, and the fixed lens barrel block 1 without the flat surface 12x
The effect of the present invention can be clearly understood by comparing the distance R from the center (optical axis O) of No. 2 to the outer peripheral surface. The distance H in FIG.
And the distance R represent the dimensions of the same places as those shown in FIG. The upward direction in FIG. 21 is the front direction of the camera.

In this embodiment, the fixed lens barrel block 1
Although the present invention has been described based on 2 and the straight guide cylinder 17, the present invention is not limited to this, and the present invention can be applied to other members using a key connection.

The zoom lens camera operates as follows. When the power switch (not shown) is turned on while the zoom lens barrel 10 is in the lens retracted state shown in FIG. Then, this rotation is transmitted to the drive pinion 15 via the gear train 26 supported by the support portion 32, and the third
Since the movable lens barrel 16 is rotated in the extending direction, the second movable lens barrel 19 and the first movable lens barrel 20 are slightly extended in the optical axis direction together with the third movable lens barrel 16, and the camera widens the zoom lens. The camera is ready for shooting at the end.

In this photographing enabled state, when the zoom operation means 62 is operated to the telephoto side, the whole movement motor 25 is driven to rotate in the forward direction via the whole movement motor control means 60, and is driven via the drive pinion 15 and the outer peripheral gear 16b. To rotate the third movable barrel 16 in the extending direction. Therefore,
The third movable lens barrel 16 is extended from the fixed lens barrel block 12 due to the relationship between the female helicoid 12a and the male helicoid 16a, and at the same time, the straight guide tube 17 is fixed by the relationship between the engagement projection 17c and the straight guide groove 12b. Block 12
With the third movable lens barrel 16 in a state of not rotating relative to the optical axis, it advances forward of the optical axis. At this time, the second movable lens barrel 19
The follower pin 18 is connected to the lead groove 17b and the linear guide groove 1
By simultaneously engaging with the third movable lens barrel 6c, the second movable lens barrel 6 relatively moves in the same direction as the third movable lens barrel 16 and moves forward in the optical axis with respect to the third movable lens barrel 16. The first movable lens barrel 20 is
Since the linear movement guide member 22 guides the linear movement and the follower pin 24 is moved and guided by the lead groove 19 c, the second movable lens barrel 19 and the AF / AE shutter unit 21 are not rotated relative to the fixed lens barrel block 12. Advances ahead of the optical axis.

While the zoom lens barrel 10 is driven in this manner, the rear group moving motor 30 is not driven, so that the front lens group L1 and the rear lens group L2 are integrated with the optical axis while maintaining a constant distance from each other. (See FIG. 8). The focal length set by the zoom operation unit 62 is displayed by a display unit (not shown).

[0044] In any focal length thus set to the zoom operation manual stage 62, when the release button is pushed one step, by metering command is given to the distance measurement command and photometric apparatus 65 in the distance measuring device 64, measuring Distance and photometry are started. Thereafter, when the release button is pressed two stages, both of the rear lens group driving motor 30 and the entire movement motor 25, a moving amount obtained by the object distance information by the distance measuring device 64, it is more set the zoom operation manual stage 62 The AE motor control is performed by moving the front lens group L1 and the rear lens group L2 by the moving amount determined by taking into account the moving amount obtained by the focal length information, to achieve the set focal length, and to focus on the subject. The AE motor 29 rotates the annular driving member 49 in accordance with the subject luminance information from the photometric device 65 via the means 66, and drives the shutter 27 so as to satisfy a predetermined exposure. After the shutter release, the entire moving motor 2
5 and the rear group moving motor 30 are both immediately driven, and the front lens group L1 and the rear lens group L2 are returned to the state before the shutter release.

When the zoom operation means 62 is operated to the wide side, the whole moving motor 25 is driven to rotate in the reverse direction, and the third movement is performed.
The movable lens barrel 16 is rotated in the retracting direction, and is retracted into the fixed lens barrel block 12 together with the rectilinear guide cylinder 17. At the same time, the second movable lens barrel 19 is retracted into the movable lens barrel 16 while rotating in the same direction as the third movable lens barrel 16, and
The movable lens barrel 20 is moved by A with respect to the rotating second movable lens barrel 19.
It is moved together with the F / AE shutter unit 21.
Also during this retraction drive, the rear group moving motor 30 is not driven, as in the above-described retraction drive. When the power switch is turned off after the zoom lens has moved to the wide end position, the zoom lens barrel 10 is moved into the lens storage position shown in FIG.

[0046]

As described above, according to the present invention, the outer cylinder having the straight guide groove parallel to the optical axis on the inner peripheral surface and the radial projection fitted into the straight guide groove are provided. A linear guide mechanism for a lens barrel having a linear member fitted into the outer cylinder, wherein the bottom surface of the linear guide groove is a plane substantially orthogonal to the radial direction, and the linear guide is provided on the outer surface of the outer cylinder. Since the cutout surface parallel to the bottom surface of the groove is formed, even if the member is engaged with the key and the key groove, the size of the device can be reduced while maintaining the predetermined strength of the key.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a main part of an embodiment of a straight guide mechanism to which the present invention is applied.

FIG. 2 is a perspective view showing a state different from FIG. 1 of a main part of the rectilinear guide mechanism.

FIG. 3 is a perspective view showing a main part of a zoom lens barrel according to the embodiment.

FIG. 4 is a perspective view showing a state in which an AF / AE shutter unit of the zoom lens barrel is assembled to a first movable barrel.

FIG. 5 is an exploded perspective view showing main members of an AF / AE shutter unit of the zoom lens barrel.

FIG. 6 is a perspective external view showing a third movable lens barrel of the zoom lens barrel.

FIG. 7 is a front view showing a fixed barrel block of the zoom lens barrel.

FIG. 8 is an upper half sectional view showing a maximum extension state of the zoom lens barrel.

FIG. 9 is an upper half sectional view showing a main part of the zoom lens barrel in a lens housed state.

FIG. 10 is an upper half sectional view showing a main part of the zoom lens barrel in a maximum extended state.

FIG. 11 is an upper half cross-sectional view showing a lens storage state of the entire zoom lens barrel.

FIG. 12 is an exploded perspective view showing the entire zoom lens barrel.

FIG. 13 is a block diagram showing a control system for controlling the operation of the zoom lens barrel.

FIG. 14 is a perspective view of a fixed barrel portion of the zoom lens barrel.

FIG. 15 is a rear view showing a fixed lens barrel block of the zoom lens barrel.

FIG. 16 is a side cross-sectional view showing an engagement state between a linear guide groove and an engagement projection to which the present invention is applied.

FIG. 17 is a cross-sectional view showing an engagement state between a straight guide groove and an engagement projection to which the present invention is applied.

FIG. 18 is a plan view showing an engagement state between a linear guide groove and an engagement projection to which the present invention is applied.

FIG. 19 is a diagram schematically showing an engagement state between a straight guide groove and an engagement protrusion to which the present invention is applied.

FIG. 20 is an enlarged cross-sectional view showing an engagement state between a linear guide groove and an engagement projection to which the present invention is applied.

FIG. 21 is a sectional view showing a fixed lens barrel block and a cartridge housing structure.

[Explanation of symbols]

 Reference Signs List 12 Fixed lens barrel 12a Female helicoid 12bi Straight guide groove 12bni Straight guide groove 12x Flat surface (cutout surface) of fixed lens barrel outer peripheral surface 17 Straight guide tube 17ci Engage projection 17cni Engage projection W ' Width) W Width of the engagement protrusion (key width) t 'The amount of engagement of the engagement protrusion with the linear guide groove (the amount of engagement) t The amount of engagement of the engagement protrusion with the linear guide groove (the amount of engagement)

──────────────────────────────────────────────────続 き Continued on the front page (56) References JP-A-3-158809 (JP, A) JP-A-7-72363 (JP, A) JP-A-6-55109 (JP, U) (58) Field (Int.Cl. ⁷ , DB name) G02B ^7/ 04-7/105

Claims (3)

(57) [Claims] Having a full radial projection fitted in the linear guide grooves, this a full straight member fitted into the outer cylinder; 1. A inner peripheral surface outer cylinder and having parallel linear guide groove and the optical axis having In the rectilinear guide mechanism for a lens barrel, the bottom surface of the rectilinear guide groove is formed as a plane substantially orthogonal to the radial direction, and a cutout surface parallel to the bottom surface of the rectilinear guide groove is formed on the outer peripheral surface of the outer cylinder. and the distance from the cutout surface to the optical axis, of the outer peripheral surface of the outer tube
From the outer peripheral surface portion where the notched surface is not formed, the optical axis
A linear guide mechanism for the lens barrel, which is shorter than the distance to 2. A linear guide for the lens barrel according to claim 1.
In mechanism, the female helicoid, which is further formed on the inner peripheral surface of the outer cylinder; has a male helicoid engaged with the female helicoid, the straight member and the relative rotation is freely optical axis direction and the helicoid ring that moves together The female helicoid of the outer cylinder is cut off on both sides in the width direction of the linear guide groove to be discontinuous, and a part of the female helicoid is provided at the center in the width direction of the linear guide groove. A linear guide mechanism for a lens barrel having projections formed. 3. An outer cylinder having a linear guide groove parallel to the optical axis on an inner peripheral surface; a linear member having a radial projection fitted in the linear guide groove and fitted in the outer cylinder; A female helicoid formed on the inner peripheral surface of the female helicoid; a helicoid ring having a male helicoid meshed with the female helicoid; The female helicoid of the outer cylinder is cut off on both sides in the width direction of the rectilinear guide groove to be discontinuous, and a projection that forms a part of the female helicoid is formed at the center in the width direction of the rectilinear guide groove. A linear guide mechanism for the lens barrel.