JP3869483B2 - Zoom lens camera with zoom finder - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a zoom lens and a camera including a zoom finder that individually moves at least a front lens group and a rear lens group.
[0002]
[Prior art and its problems]
Since the zoom compact camera is a camera for observing an image of the zoom finder optical system different from the image of the zoom photographing optical system, when the zoom operation means for changing the focal length is operated, the subject at a specific subject distance always ( Usually, it is not necessary to perform zooming while maintaining a focused state on a subject at infinity. Therefore, the degree of freedom of the lens configuration and the lens driving mechanism is increased by moving the entire lens group during zooming and moving and focusing the focusing lens group during focusing.
The zoom lens of a compact camera has a multistage extended barrel structure of two stages or three stages or more for compactness. Such a zoom lens has a backlash in a mechanism for extending the lens barrel, for example, a motor, a gear train, a helicoid, etc., and therefore the entire lens group is moved from the position moved by zooming, and the focusing lens group is moved. However, it may not be in focus. Therefore, during focusing, it is desirable to move not only the focus lens group but the entire lens group so that the entire lens group is reliably disposed at a predetermined focal length position.
[0003]
However, when the entire lens group is moved, if a zoom finder that zooms in conjunction with zooming is provided, the zoom finder zooms each time focus adjustment is performed, making it difficult to observe the subject with the finder.
[0004]
OBJECT OF THE INVENTION
The present invention was made based on the awareness of the problems of conventional zoom lenses. Zooming and zoom finder zooming are performed by moving the entire lens group, and the entire lens group and focusing lens group are moved during focus adjustment. An object of the present invention is to provide a zoom lens camera in which the zoom finder does not change magnification during focus adjustment.
[0005]
SUMMARY OF THE INVENTION
  To achieve this object, the present invention provides a zoom lens including at least a movable front group lens and a rear group lens; and the rear group lens is moved toward and away from the front group lens.LetRear group moving means: the front group lens, the rear group lens and the rear group moving means are integrated.A lens barrel movably held back and forth; driving the lens barrel to move the front group lens, rear group lens and rear group moving means back and forth together for zoomingZoom finder; finder interlocking means for changing the magnification of the zoom finder in conjunction with the whole moving means; and driving the whole moving means to perform zooming control, and driving the whole moving means and the rear group moving means. Control means for adjusting the focus, and the whole moving meansDrives the lens barrel to zoomWhenZoom systemBacklash is caused when the entire moving means zooms the zoom finder through the finder interlocking means.systemSet smaller than the backlash, the control means when adjusting the focusDriving the rear group moving means;The whole moving means,In the direction opposite to the driving direction just before stopping,Zoom systemThan backlashMany and the finderBelow system backlashOnly driveThe front group lens, the rear group lens, and the rear group moving means are integrally moved back and forth within a range in which the zoom finder does not change magnification.Letting,It has the characteristics.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described 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 includes two groups, a front group lens L1 and a rear group lens L2.
[0007]
The camera body includes an overall movement motor drive means 60, a rear group movement motor drive means 61, a zoom operation means 62, a shutter release means 63, a distance measuring device 64, a photometry device 65, an AE motor drive means 66, and these. Control means (CPU) 210 for controlling is provided.
[0008]
When the zoom operation means 62 (wide zoom button 62WB, tele zoom button 62TB) such as a zoom lever provided on the camera body is operated, the control means 210 controls the front group lens L1 with respect to the entire movement motor drive means 60. A movement command for moving the zoom lens including the rear lens group L2 from the wide side to the tele side or a movement command for moving from the tele side to the wide side is given. Receiving this movement command, the total movement motor driving means 60 drives the total movement motor 25 to move the zoom lens from the wide side to the tele side or from the tele side to the wide side. The focal length is changed by the operation of the zoom operation means 62 by the photographer, and is set to an arbitrary focal length. Although not shown, the image magnification of the viewfinder field changes 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 means 62 by observing the change in the image magnification in the viewfinder field. Further, the focal length set by the operation of the zoom operation means 62 can be recognized by a numerical value displayed on the LCD display panel, for example.
[0009]
The control means 210 also drives the overall movement motor 25 driven via the overall movement motor control means 60 and is driven via the rear group movement motor control means 61 when the shutter release means 63 is operated. The rear group moving motor 30 is driven to focus the zoom lens on the subject. The shutter release means 63 is composed of a photometry switch and a release switch that are linked to the release button. When the shutter release means 63 is pressed one step, the photometry switch is turned on, and the control means 310 sends a distance measurement command to the distance measurement device 64 and the photometry device 65. The release switch is turned on by pressing the button two times, and the control means 210 drives the AE motor 29 of the AF / AE shutter unit 21 via the AE motor drive means 66 to operate the shutter 27. . The control unit 210 receives the photometry output from the photometry device 65, drives the AE motor 29, and opens the shutter blade 27a of the shutter 27 for a predetermined time.
[0010]
When the zoom operation unit 62 is operated, the control unit 210 drives the entire moving motor 25 to move the front group lens L1 and the rear group lens L2 together. Simultaneously with this movement, the rear group movement motor 30 may be operated via the rear group movement motor control means 61. However, an important point in this zoom lens camera is that the front group lens after receiving the operation of the zoom operation means 62. The movement of L1 and the rear lens group L2 is not performed by the conventional zooming concept in which the focal length is continuously changed without moving the focal position. That is, when the zoom operation means 62 is operated,
(1) A mode in which only the entire moving motor 25 is operated to move the front group lens L1 and the rear group lens L2 back and forth without changing the air distance between them, and
(2) A mode in which both the entire moving motor 25 and the rear group moving motor 30 are operated to move the front group lens L1 and the rear group lens L2 while changing the air distance between them (without considering the focal position);
Is possible.
[0011]
In the mode of (1), it is impossible to always focus on a subject at a specific distance. However, in a lens shutter type camera such as this camera that does not observe an image by a photographing optical system, the focus is not released. There is no problem at all because it only has to match. In the mode (2), the front lens group L1 and the rear lens group L2 are moved while allowing the movement of the focal position. Focusing is performed by operating both the entire moving motor 25 and the rear group moving motor 30 during shutter release.
[0012]
After executing the control mode (1) or (2) according to the operation of the zoom operation means 62, the shutter release means in at least a part of the focal length range set by the zoom operation means 62. When 63 is operated, both the whole moving motor 25 and the rear group moving motor 30 are operated to focus on the subject. At this time, the movement amount of the front group lens L1 and the rear group lens L2 by the whole movement motor 25 and the rear group movement motor 30 is not only the movement amount obtained from the subject distance information by the distance measuring device 64 but also by the zoom operation means 62. It is determined in consideration of the amount of movement obtained from the set focal length information. In this way, when the shutter release means 63 is operated, if both the whole moving motor 25 and the rear group moving motor 30 are operated to perform the focusing operation, a degree of freedom is produced in the control of the lens position. Becomes easier.
[0013]
Theoretically, when the zoom operation unit 62 is operated, neither the overall movement motor 25 nor the rear group movement motor 30 is operated, and only the viewfinder magnification and focal length information of the finder are changed, and the shutter release unit 63 is operated. Is operated, the entire moving motor 25 and the rear group moving motor 30 are simultaneously operated by the focal distance information and the subject distance information by the distance measuring device 64, and are uniquely determined by the focal distance information and the subject distance information. It is also possible to move the front lens group L1 and the rear lens group L2 to the determined positions.
[0014]
Next, a specific embodiment of the zoom lens barrel of the above concept will be described mainly with reference to FIGS. 11 and 12.
First, the schematic configuration and operation of the zoom lens barrel 10 will be described. The first moving barrel 20, the second moving barrel 19, the third moving barrel 16, and the fixed barrel block 12 are provided in order from the front. It has been. The third movable lens barrel 16 is screwed into the cylindrical portion of the fixed lens barrel block 12, and advances and retracts in the optical axis direction as it rotates. The third movable lens barrel 16 has a rectilinear guide tube 17 that is integrally moved in the optical axis direction and whose rotation is restricted, and the second movable lens barrel 19 rotates relative to the rectilinear guide tube 17. While moving forward and backward in the optical axis direction. The rotation of the first moving lens barrel 20 is restricted, and the first moving lens barrel 20 moves back and forth in the optical axis direction by relative rotation with respect to the second moving lens barrel 19. The entire moving motor 25 is fixed to the fixed lens barrel block 12, and the shutter mounting base 40 on which the AE motor 29 and the rear group moving motor 30 are mounted is fixed to the first moving lens barrel 20. The front group lens L1 is a lens having positive power supported by the lens support tube 34, and the rear group lens L2 is a lens having negative power supported by the lens support tube 50.
[0015]
The fixed barrel block 12 fixed in front of the aperture plate 14 of the camera body has a female helicoid 12a and a plurality of rectilinear guide grooves 12b parallel to the optical axis O on the inner peripheral surface of the cylindrical portion. ing. A cord plate 13a having a predetermined pattern is fixed to the bottom of one of the plurality of straight guide grooves 12b. The code plate 13 a is configured as a part of the flexible printed circuit board 13 located outside the fixed barrel block 12. The aperture plate 14 has an aperture 14a that determines an exposure area to the film.
[0016]
The cylindrical portion of the fixed barrel block 12 is formed with a gear housing portion 12c that bulges outward in the radial direction and extends in the optical axis direction (see FIG. 7). A drive pinion 15 that is long in the optical axis direction is rotatably accommodated in the gear accommodating portion 12c. The drive pinion 15 is rotatably supported at both ends of the shaft 7 by a support hole 4 provided in the fixed barrel block 12 and a support hole 31 a provided in the gear support plate 31. The tooth surface of the drive pinion 15 protrudes from the inner peripheral surface of the fixed barrel block 12.
[0017]
A third movable lens barrel 16 is screwed into the inner periphery of the fixed lens barrel block 12. The third movable lens barrel 16 has a plurality of rectilinear guide grooves 16c extending in the optical axis direction on the inner peripheral surface, and a male helicoid 16a meshing with the female helicoid 12a of the fixed lens barrel block 12 on the outer periphery of the rear end portion. The outer peripheral gear 16b (see FIG. 6) meshes with the drive pinion 15. The drive pinion 15 has an axial length that meshes with the outer peripheral gear 16 in the entire movement range of the third moving barrel 16 in the optical axis direction.
[0018]
A rectilinear guide tube 17 is supported on the inner periphery of the third movable lens barrel 16 so as to be movable integrally with the third movable lens barrel 16 in the optical axis direction and relatively rotatable around the optical axis. The rectilinear guide tube 17 is provided on the outer periphery of the rear portion with a rear end flange portion 17d provided with a plurality of engagement protrusions 17c projecting radially outward, and with a slight gap in front of the rear end flange portion 17d. The flange portion 17d has a retaining flange portion 17e having a diameter smaller than that of the flange portion 17d. 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) projecting radially inward on the inner periphery of the rear end portion, and the engaging projections 16d are inserted from the cutout portions 17f. It is located in the gap between the flange portions 17d and 17e, and is coupled to the rectilinear guide tube 17 by rotating relative to the rectilinear guide tube 17. An aperture plate 23 having an opening 23a substantially the same shape as the aperture 14a is fixed to the rear end surface of the rectilinear guide tube 17.
[0019]
The rectilinear guide tube 17 also has a plurality of rectilinear guide grooves 17a parallel to the optical axis O on the inner peripheral surface thereof and penetrates the peripheral wall of the guide tube 17 and is inclined with respect to the circumferential direction and the optical axis direction. A plurality of lead grooves 17b are formed.
[0020]
A second movable lens barrel 19 is fitted on the inner periphery of the rectilinear guide tube 17. The second movable lens barrel 19 has a plurality of lead grooves 19c inclined on the inner peripheral surface opposite to the lead grooves 17b, and has a plurality of trapezoidal cross-sections protruding radially outward on the outer periphery of the rear end portion. It has a follower protrusion 19a and a follower pin 18 located on the follower protrusion 19a. The follower pin 18 includes a ring member 18b and a center fixing screw 18a that supports the ring member 18b on the follower protrusion 19a. The follower protrusion 19a is slidably fitted into the lead groove 17b of the rectilinear guide tube 17, and the follower pin 18 is slidably fitted into the rectilinear guide groove 16c of the third moving barrel 16. Therefore, when the third movable lens barrel 16 rotates, the second movable lens barrel 19 moves straight in the optical axis direction while rotating.
[0021]
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 is guided by a straight guide member 22 by engaging a plurality of follower pins 24 provided on the outer periphery of the rear end portion with a corresponding inner peripheral lead groove 19 c. As shown in FIGS. 1 and 2, the rectilinear guide member 22 protrudes outward in the radial direction of the annular portion 22a, a pair of guide legs 22b extending from the annular portion 22a in the optical axis direction, and the annular portion 22a. And a plurality of engaging projections 28 slidably engaged with the straight guide groove 17 a, and between the inner peripheral surface of the first movable lens barrel 20 and the AF / AE shutter unit 21, the guide legs 22 b Is inserted so that it can be guided straight ahead.
[0022]
The annular portion 22a of the rectilinear guide member 22 is coupled to the rear end portion of the second moving barrel 19 so as to be integrally movable in the optical axis direction and relatively rotatable around the optical axis. The rectilinear guide member 22 is provided on the outer periphery of the rear portion with a rear end flange portion 22d provided with a plurality of engagement protrusions 28 projecting radially outward, and with a slight gap in front of the rear end flange portion 22d. The flange portion 22d has a retaining flange portion 22c having a diameter smaller than that of the flange portion 22d, and has a plurality of cutout portions 22e in the circumferential direction of the retaining flange portion 22c (see FIG. 1). The second movable lens barrel 19 has a plurality of engaging projections 19b (FIG. 11) projecting radially inward on the inner periphery of the rear end portion, and the engaging projections 19b are inserted into the cutout portions 22e. It is located in a gap between the flange portions 22c and 22d, and is coupled to the rectilinear guide member 22 by rotating relative to the rectilinear guide member 22. With the above configuration, the first moving lens barrel 20 moves straight forward and backward in the optical axis direction with respect to the second moving lens barrel 19 while the rotation is restricted when the second moving lens barrel 19 rotates forward and backward. To do.
[0023]
A barrier device 35 having barrier blades 48a and 48b is mounted on the front end of the first moving lens barrel 20, and a shutter 27 including three shutter blades 27a (FIG. 5) is provided on the inner peripheral surface. The AF / AE shutter unit 21 is fitted and fixed. The AF / AE shutter unit 21 has a plurality of fixing holes 40 a (FIG. 3) formed at equal angular intervals on the outer peripheral portion of the shutter mounting base 40. The plurality of follower pins 24 also serve as fixing means for the AF / AE shutter unit 21, and the follower pins 24 are fitted and fixed in the pin holes 20a formed in the first movable lens barrel 20 and the fixing holes 40a. The shutter unit 21 is fixed to the first movable lens barrel 20 (see FIG. 4). The follower pin 24 can be fixed by means such as adhesion or screwing. Reference numeral 41 denotes a decorative plate fixed to the front end portion of the first movable lens barrel 20.
[0024]
As shown in FIGS. 5 and 12, the AF / AE shutter unit 21 has a shutter mounting base 40, a shutter blade support ring 46 fixed to the rear portion of the shutter mounting base 40, and the shutter mounting base 40. And a lens support tube 50 (rear group lens L2) supported relatively movably. The shutter mount 40 supports a front group lens L1, an AE motor 29, and a rear group movement motor 30. The shutter mount 40 includes an annular portion having a photographing opening 40d through which the lens support tube 34 is inserted, and three leg portions 40b extending rearward from the annular portion. Two of the gaps between the three leg portions 40b are configured as a rectilinear guide portion 40c that moves and guides a pair of guide leg portions 22b of the rectilinear guide member 22 slidably.
[0025]
The shutter mount 40 is further connected to an AE gear train 45 that transmits the rotation of the AE motor 29 to the shutter 27, a lens drive gear train 42 that transmits the rotation of the rear group moving motor 30 to the screw shaft 43, and the flexible printed circuit board 6. The photo interrupters 56 and 57 and the rotating plates 58 and 59 provided with a number of slits extending in the radial direction in the circumferential direction are supported. The photo interrupter 57 and the rotating plate 59 constitute a rear group moving motor encoder that detects the rotation of the rear group moving motor 30, and the photo interrupter 56 and the rotating plate 58 are for the AE motor that detects the rotation of the AE motor 29. An encoder is configured.
[0026]
Between the shutter mount 40 and the shutter blade support ring 46 fixed to the mount 40, the shutter 27, a support member 47 pivotally supporting the three shutter blades 27a of the shutter 27, and the shutter blade 27a are rotated. An annular drive member 49 for applying power is located. The annular drive member 49 includes three operation protrusions 49a that are respectively engaged with the three shutter blades 27a at equal angular intervals. The shutter blade support ring 46 has a photographing opening 46a on the front wall portion and three support holes 46b provided at equiangular intervals around the photographing opening 46a, and is exposed from the rectilinear guide portion 40c on the outer peripheral portion. The pair of guide legs 22b has a deflection regulating surface 46c that slidably supports the inner peripheral surfaces (see FIGS. 9 and 10).
[0027]
Further, the support member 47 positioned in front of the shutter blade support ring 46 includes a photographing opening 47a that faces the photographing opening 46a and three shaft portions 47b that respectively face the three support holes 46b (only one place is shown in FIG. 5). ). Each of the three shutter blades 27a has a shaft hole 27b through which the shaft portion 47b is inserted at one end and a shielding portion that shields the photographing openings 46a and 47a at the other end. Between the end portions, there is a long hole 27c through which the operation protrusion 49a is inserted. The support member 47 is fixed to the shutter blade support ring 46 in a state where the shaft portions 47b that respectively support the shutter blades 27a are fitted into the corresponding support holes 46b of the shutter blade support ring 46.
[0028]
The annular drive member 49 has a gear portion 49 b that receives rotation from the gear train 45 on the outer peripheral portion. The support member 47 has three arc grooves 47c along the circumferential direction at positions close to the three shaft portions 47b. The three operation protrusions 49a of the annular drive member 49 penetrate through the three arc grooves 47c and engage with the long holes 27c of the shutter blades 27a. The shutter blade support ring 46 is inserted from the rear side of the shutter mounting base 40 while supporting the annular drive member 49, the support member 47 and the shutter 27, and is screwed to the shutter mounting base 40.
[0029]
  Behind the shutter blade support ring 46 is disposed a lens support tube 50 supported on the shutter mounting base 40 via slide shafts 51 and 52 so as to be relatively movable. The shutter mount 40 and the lens support tube 50 are urged to move away from each other by the coil spring 3 fitted to the slide shaft 51, thereby eliminating the backlash between the two. Further, 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 tube 50 is screwed to the female screw, and the drive gear 42a 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 either forward or backward, the screw shaft 43 moves forward and backward with respect to the drive gear 42a, and the lens support cylinder 50WithThe rear group lens L2 moves relative to the front group lens L1.That is, the lens support tube 50 corresponds to a support lens barrel.
[0030]
At the front portion of the shutter mounting base 40, presser members 53 and 55 for pressing the motors 29 and 30 supported on the shutter mounting base 40 are screwed. Motors 29 and 30 and photo interrupters 56 and 57 are connected to the flexible printed circuit board 6 having one end fixed to the shutter mounting base 40. In a state where the first to third movable lens barrels 20, 19, 16 and the AF / AE shutter unit 21 are assembled, the aperture plate 23 is fixed to the rear end surface of the rectilinear guide tube 17, and the front end of the fixed lens barrel block 12 is used. An annular retaining member 33 is fitted to the portion.
[0031]
  In the above embodiment, the front group lens L1 and the rear group lens L2 supported by the lens support tube 50 are one of the constituent members of the AF / AE shutter unit 21,Rear groupThe drive motor 30 isAF / AE shutterIt is mounted on the unit 21. According to this configuration, there is an advantage that the support structure and the drive structure of the rear lens group L2 can be simplified. However, the rear lens group L2 is connected to the shutter mounting base 40, the annular drive member 49, the support member 47,Shutter 27And shutterBlade support ringThe present zoom lens can be realized even if it is a separate member from the AF / AE shutter unit 21 provided with 46 and the like and is supported by a support member separate from the unit.
[0032]
The zoom lens camera operates as follows by the rotation of the entire movement motor 25 and the rear group movement motor 30. When the zoom lens barrel 10 is retracted most, the entire moving motor 25 rotates in the positive direction when the power switch is turned on. Then, this rotation is transmitted to the drive pinion 15 via the gear train 26 supported by the support portion 32, and the third movable lens barrel 16 is rotated in the feeding direction. The movable lens barrel 20 and the third movable lens barrel 16 are slightly extended in the optical axis direction, and the camera is ready to shoot with the zoom lens positioned at the wide end. At this time, the focal length of the zoom lens composed of the front and rear group lenses L1 and L2 is determined based on the fact that the position of the straight guide tube 17 relative to the fixed barrel block 12 is detected by relative sliding of the code plate 13a and the contact terminal 9. Has been detected.
[0033]
In this photographing enabled state, when the zoom tele switch is turned on, the entire moving motor 25 is driven to rotate in the forward direction, and the third moving lens barrel 16 is rotated in the extending direction via the drive pinion 15 and the outer peripheral gear 16b. Therefore, the third movable barrel 16 is fed out from the fixed barrel block 12 due to the relationship between the female helicoid 12a and the male helicoid 16a, and at the same time, the rectilinear guide barrel 17 is fixed due to the relationship between the engagement protrusion 17c and the rectilinear guide groove 12b. In a state where it does not rotate relative to the lens barrel block 12, it advances forward with the third moving lens barrel 16. At this time, the second movable lens barrel 19 has the follower pin 18 engaged with the lead groove 17b and the rectilinear guide groove 16c at the same time, so that the movable lens barrel 16 rotates relative to the third movable lens barrel 16 in the same direction. Relative to the optical axis. The first movable lens barrel 20 is guided in a straight line by the straight guide member 22, and the follower pin 24 is moved and guided by the lead groove 19c, so that the second movable lens barrel 20 does not rotate relative to the fixed lens barrel block 12. 19 advances forward along with the AF / AE shutter unit 21 along the optical axis. At this time, the focal length of the zoom lens composed of the front and rear group lenses L1 and L2 is determined based on the fact that the position of the straight guide tube 17 relative to the fixed barrel block 12 is detected by relative sliding of the code plate 13a and the contact terminal 9. Has been detected.
[0034]
Since the rear group moving motor 30 is not driven while the zoom lens barrel 10 is driven in this way, the front group lens L1 and the rear group lens L2 move integrally in the optical axis direction while keeping the distance between them constant. (See FIG. 8). The focal length input via the zoom code plate 13a is displayed on the LCD display panel.
[0035]
  Zoom operation means62When the release button is pressed one step at an arbitrary focal length set by, a distance measurement command is given to the distance measuring device 64 and a photometry command is given to the photometry device 65, and the whole moving motor 25 and the rear group moving motor 30 Both move the front lens group L1 and the rear lens group L2 by the amount of movement obtained from the set focal length information and subject distance information by the distance measuring device 64 to set the focal length and focus on the subject. When the release button is pressed twice in this state, the AE motor 29 rotates and drives the annular drive member 49 according to the subject luminance information from the photometry device 65 via the AE motor control circuit 66 to obtain a predetermined exposure. The shutter 27 is driven so as to satisfy. After the shutter release is completed, both the entire moving motor 25 and the rear group moving motor 30 are driven immediately, and the front group lens L1 and the rear group lens L2 are returned to the state before the shutter release.
[0036]
When the zoom wide switch is turned on, the entire moving motor 25 is driven to rotate in the reverse direction, the third moving lens barrel 16 is rotated in the retracting direction, and is retracted into the fixed lens barrel block 12 together with the rectilinear guide tube 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 first movable lens barrel 20 is rotated. On the other hand, it is retracted together with the AF / AE shutter unit 21. Even during this retraction drive, the rear group moving motor 30 is not driven as in the above-described retraction drive.
[0037]
When the zoom lens barrel 10 is moved to the wide end position and then the power switch 212 is turned on and the power is turned off, the zoom lens barrel 10 is shown in FIG. It is carried into the storage position. Before that, the entire movement motor 25 is activated and the rear lens group L2 is moved to the home position.
[0038]
FIG. 14 schematically shows the outline and backlash of the transmission mechanism from the entire movement motor 25 to the front group, rear group lenses L1 and L2 and the zoom finder optical system (variable magnification lens L5) in the present embodiment. It is shown. The front lens group L1 and the rear lens group L3 are translated and zoomed along the optical axis O, and the variable magnification lens L5 is translated along the optical axis O1 to change the magnification (change the image magnification).
[0039]
  In zooming of the optical system of this cameraZoom systemThe backlash is generated by the gear train backlash BL1 by the gear mechanism 341 from the pinion 25a of the entire moving motor 25 to the reduction gear train 26 and the drive pinion 15, and from the drive pinion 15 to the outer peripheral gear 16b (third movable lens barrel 16). By the fixed barrel block 12, the detection backlash BL2 of the zoom code detection mechanism 342 up to the rectilinear guide cylinder 17, and the lens barrel feeding mechanism 343 from the rectilinear guide cylinder 17 to the second movable barrel 19 and the first movable barrel 20 There is a lens barrel backlash BL3. Detection backlash BL2 is the front groupLens L1It is also a backlash involved up to the brush portion 9a for detecting the position of the cord and the code plate 13a.
[0040]
  On the other hand, in zoom operation of zoom finder optical systemFinder systemThe backlash includes a gear train backlash BL1 by the gear mechanism 341, and a finder backlash BL4 by the finder drive mechanism 344 including the drive pinion 15 to the outer peripheral gear 16b (third movable barrel 16) and the finder drive gear 334.Since the gear train backlash BL1 is common to the gear train backlash BL1 in the zoom system backlash, the backlash unique to the finder system backlash is only the finder backlash BL4.
[0041]
  Backlash BL1, BL2, BL3,In BL4Each of the whole moving motors 25Normal when the direction of rotation changesGear mechanism, cam mechanismBacklash is included and detection backlash BL2 and finder backlash BL4 are specific backlashAlsoincluded. Each backlashBL1, BL2, BL3, BL4The size of is schematically shown by the width of each recess in the figure.
[0042]
16 and 17 show an enlarged view of the code plate 13a and the brush portion 9a forming the zoom code and their contact state. The code plate 13a includes four independent electrode patterns ZC0, ZC1, ZC2, and ZC3 formed on the insulating substrate 13b. Since the electrode patterns ZC0, ZC1, ZC2, and ZC3 have a thickness, they rise from the insulating substrate 13b by the thickness. Accordingly, in the brush portion 9a, the curved vertex portion 9d is in sliding contact with the insulating substrate 13b and the electrode pattern, but at the electrode pattern switching position (zoom code on / off switching position), the portion 9e or the portion 9e separated from the vertex portion 9d or The portion 9f contacts and separates from the electrode pattern. Therefore, when the brush portion 9a contacts and separates from the electrode patterns ZC0, ZC1, ZC2, and ZC3, an error of the distance d0 is generated. Therefore, in the present embodiment, the reference position of the front group lens L1 (and the rear group lens L2) is a position (mode) at which the brush portion 9a is turned ON / OFF at the film surface side edge of the electrode patterns ZC0, ZC1, ZC2, and ZC3. In this case, the distance d0 is taken into consideration.
[0043]
FIG. 15 shows the lens position with reference to the apex portion 9d of the brush portion 9a. With reference to this figure and FIG. 14, the operation | movement at the time of zooming of this Embodiment and the operation | movement at the time of focus adjustment are demonstrated.
[0044]
In the present embodiment, in the shooting standby state in which the power is turned on, the camera is stopped at the storage side standby position with respect to the zoom code switching position. For example, when zooming from the wide side to the tele side and stopping, the entire movement motor 25 rotates in the forward direction, and the zoom code is further turned off from the zoom code OFF / ON detection position where the brush portion 9a contacts the zoom code. The entire moving motor 25 is rotated forward and stopped until (a predetermined number of zoom pulses ZP1). This lens position is the folding position. The entire moving motor 25 reverses from this turning position. Then, the entire moving motor 25 is further reversed by a predetermined number of zoom pulses ZP2 from the zoom code ON / OFF detection position where the brush portion 9a comes apart after contacting the zoom code, and then stops. This lens position is the lens standby position.
[0045]
In this tele-zoom, the mechanisms 341, 342, 343, and 345 operate in a state in which the backlashes BL1 to BL4 are removed by sufficient forward rotation of the entire moving motor 25, and the front group and rear group lenses L1 and L2 are moved. The variable magnification lens L5 is moved to the position corresponding to the folding position at the folding position (see FIG. 14A). At this position, the backlashes BL1 to BL4 in the tele direction when the entire moving motor 25 rotates forward are not present.
[0046]
When the entire movement motor 25 reverses from the turn-back position, the gear mechanism 341, the detection mechanism 342, and the lens barrel drive mechanism 343 finish driving the backlashes BL1, BL2, and BL3 at the beginning of the reverse rotation of the entire movement motor 25. The front group lens L1 and the rear group lens L2 are moved to the lens standby position. However, the finder drive mechanism 344 does not lose backlash during the reverse rotation of the entire moving motor 25. That is, at the lens standby position, the variable power lens L5 does not move unless the entire movement motor 25 rotates for at least the finder backlash BL4, and therefore the variable power lens L5 does not move from the position corresponding to the turn-back position (FIG. 14). (See (B)). In the present embodiment, the amount of the finder backlash BL4 is substantially matched with the amount of rotation of the entire moving motor 25 while the front group lens L1 and the rear group lens L2 are moved from the folding position to the standby position.
[0047]
  When zooming from the tele side to the wide side and stopping, the entire moving motor 25 reverses, and the entire moving motor 25 is further moved from the zoom code ON / OFF detection position where the brush portion 9a contacts and separates from the zoom code ZC0. Reverse by the number of zoom pulses (ZP2)Front groupLens L1 andRear groupThe lens L2 is moved to the lens standby position and stopped (see FIG. 14B). This standby state is the same as the standby state during telezooming.
[0048]
With the above operation, the lens stops at the same lens standby position in the same backlash state when tele zooming or wide zooming is performed.
[0049]
At the time of shooting, from this standby state, the front lens group L1 and the rear lens group L2 are moved in the tele direction according to the subject distance (see FIG. 14C), and after shooting is completed, the camera returns to the standby position. The amount of movement is set based on the zoom code OFF / ON detection position. However, the amount of movement of the front group lens L1 and the rear group lens L2 is an amount that does not exceed the folding position. Therefore, even if the entire moving motor moves by a predetermined amount during photographing, the finder zoom lens L5 does not move by the finder backlash BL4, and the finder field of view does not fluctuate.
[0050]
18 to 22 show an embodiment for obtaining the finder backlash BL4. The interlock mechanism of the zoom finder optical system in which the image magnification fluctuates in conjunction with the rotation of the entire movement motor 25 is shown.
[0051]
The rotation of the drive shaft of the overall movement motor 25 is transmitted to the drive pinion 15 via a pinion 25a and a reduction gear train 26 fixed to the drive shaft. The drive pinion 15 meshes with the outer peripheral gear 16 b of the third movable lens barrel 16 and also meshes with the small diameter gear 331 of the double gears 331 and 332. The large-diameter gear 332 interlocked with the small-diameter gear 331 meshes with the outer peripheral gear 333a of the finder interlocking gear ring 333, and further, the outer peripheral gear 333a meshes with the drive gear 334 of the variable magnification mechanism that drives the variable magnification lens of the finder optical system. Yes. That is, the rotation of the entire movement motor 25 is transmitted from the drive pinion 15 to the finder drive gear 334 via the double gears 331 and 332 and the finder interlocking gear ring 333. The finder interlocking gear ring 333 is rotatably fitted to a bearing 33 a that protrudes in a cylindrical shape from the retaining member 33.
[0052]
The shaft 331 a of the small diameter gear 331 is inserted into the shaft hole 332 a of the large diameter gear 332. The shaft 331a is formed with a pair of keys 331b symmetrically across the axis, and the shaft hole 332a is formed with a pair of key grooves 332b into which the pair of keys 331b are respectively fitted. The circumferential width of the key groove 332b is formed wider than the circumferential thickness of the key 331b. That is, while the small-diameter gear 331 rotates in a certain direction, the key 331b abuts against one radial wall of the key groove 332b and the large-diameter gear 332 is integrally driven and rotated, but the small-diameter gear 331 rotates. When the direction is changed, the key 331b is separated from one radial wall of the key groove 332b, and is rotated by a predetermined rotation angle until the key 331b contacts the other radial wall of the key groove 332b. Does not rotate. That is, the viewfinder optical system does not change magnification.
[0053]
Here, the predetermined rotation angle (hereinafter referred to as “delayed interlocking angle”) is such that the small-diameter gear 331 rotates when the entire movement motor 25 drives the lens from the standby position to the set focal length or in-focus position during photographing. It is set larger than the rotation angle. As will be described in detail later, for example, from the state where the lens is stopped at the standby position between the zoom codes, the entire moving motor 25 rotates forward during photographing to advance the front group lens L1 and the rear group lens L2, and the current zoom code. Detecting that the current zoom code is turned OFF while detecting that the first zoom pulse number ZP1 is further rotated forward by a predetermined number of pulses and then moving forward, and thereafter, the entire moving motor 25 is reversed. The delay interlocking angle is set so that the finder optical system does not change magnification while the reverse rotation is reversed by the second zoom pulse ZP2 to return the front lens group L1 and the rear lens group L2 to the standby position.
[0054]
Although details of the finder optical system are not shown, as shown in FIG. 14, the finder zoom lens L5 moves back and forth by the rotation of the finder drive gear 334, and the image magnification changes according to the focal length of the photographing lens. It is a configuration.
[0055]
As described above, in the present embodiment, the entire moving motor 25 is driven to move the front group lens L1 and the rear group lens L2 together during zooming, and the entire moving motor 25 and the rear group moving motor 30 are moved during focus adjustment. Since the front group lens L1 and the rear group lens L2 are moved to the in-focus position by driving, the front group lens L1 and the rear group lens L2 are surely moved to the in-focus position regardless of backlash during focus adjustment. Moreover, the zoom finder does not change magnification.
[0056]
【The invention's effect】
  As is apparent from the above description, the present invention provides a zoom lens including at least a front group lens and a rear group lens.And a zoom finder.When zooming, the front and rear lens groups are moved together by the whole moving means, and the zoom finder is zoomed, and when adjusting the focus, the front lens group and the rear lens group are integrated. In a camera having a zoom lens and a zoom finder for moving the rear group lens relative to the front group lens by the rear group moving unit, the front group lens, the rear group lens, and the rear group moving unit are moved by the whole moving unit. Is set smaller than the finder backlash when the entire moving means zooms the zoom finder via the finder interlocking means, and the control means performs the focus adjustment. The whole moving means is larger than the backlash amount and the finder Since driving amount of less Tsu crush amount, the focal said front lens group at the time of adjustment, the rear lens group and the rear lens group driving means so it moves the zoom finder is not scaled,Ensuring that the front lens group and rear lens group are in focus during focus adjustmentCan be moved toMoreoverOn that occasionSince the zoom finder does not change magnification, accurate focus adjustment and a comfortable finder field can be obtained.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a main part of an embodiment of a linear guide mechanism to which the present invention is applied.
FIG. 2 is a perspective view showing a state different from FIG. 1 of the main part of the linear guide mechanism.
FIG. 3 is a perspective view showing a main part of a zoom lens barrel in the present 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 lens 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 moving 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 cross-sectional view showing the main part of the zoom lens barrel in the lens storage state.
FIG. 10 is an upper half sectional view showing the main part of the zoom lens barrel in the maximum extended state.
FIG. 11 is an upper half sectional view showing a lens housing 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 that controls the operation of the zoom lens barrel;
FIG. 14 schematically shows an outline of a transmission mechanism from the entire moving motor to the front group, rear group lens and zoom finder optical system of the zoom lens camera equipped with the zoom finder of the present invention, and a backlash of the transmission mechanism. FIG.
FIG. 15 is a diagram illustrating a relationship between a zooming operation and a zoom code according to the present embodiment.
FIG. 16 is a plan view showing an outline of a zoom code of the zoom lens camera.
FIG. 17 is an enlarged side view showing the relationship between the zoom code and the brush portion.
FIG. 18 is a front view of a fixed portion of the zoom lens barrel showing an interlocking mechanism between the zoom lens drive system and the zoom finder drive system of the zoom lens camera.
FIG. 19 is an exploded perspective view of a double gear having a delay interlocking action that generates a delay operation (backlash) between the zoom lens drive system and the zoom finder drive system.
FIG. 20 is a perspective view showing a driven-side large-diameter gear in the double gear from the reverse direction.
FIG. 21 is a transverse sectional view of a shaft portion of the double gear.
FIG. 22 is a longitudinal sectional view of the double gear.
[Explanation of symbols]
25 Overall moving motor
60 Whole moving motor control means
62 Zoom operation means
63 Shutter release means
210 CPU (control means)
331 Small diameter gear
331a shaft
331b key
332 Large diameter gear
332a Shaft hole
332b Keyway
333 Finder gearing
341 Gear mechanism
342 Zoom code detection mechanism
343 Lens barrel feeding mechanism
344 Finder drive mechanism (finder interlocking means)
L1 front lens group
L2 Rear lens group
L5 finder optical system (variable lens)

Claims (4)

A zoom lens having at least a movable front group lens and rear group lens;
A rear group moving means for moving the rear group lens toward and away from the front group lens;
A lens barrel in which the front group lens, the rear group lens and the rear group moving means are integrally held so as to be movable back and forth;
Whole moving means for driving the lens barrel and moving the front group lens, the rear group lens and the rear group moving means back and forth integrally to perform zooming ;
Zoom finder;
Finder interlocking means for changing the zoom finder in conjunction with the overall movement means; and
Control means for controlling the zooming by driving the whole moving means, and for adjusting the focus by driving the whole moving means and the rear group moving means;
Zoom system backlash zooming to Rutoki the whole moving means by driving the barrel, than finder system backlash when the entire moving means is zooming the zoom finder via the finder interlocking means Set small,
When the focus adjustment is performed, the control unit drives the rear group moving unit, and moves the entire moving unit in a direction opposite to the driving direction immediately before stopping , more than the zoom system backlash , and the finder. A zoom equipped with a zoom finder, wherein the zoom lens is driven only below the system backlash , and the front group lens, the rear group lens and the rear group moving means are moved back and forth integrally within a range in which the zoom finder does not change magnification. Lens camera. A zoom operation unit, and the control unit drives the overall movement unit in response to an operation of the zoom operation unit, and the focus adjustment is performed when the whole movement unit is driven in the focus adjustment. 2. The zoom lens camera having a zoom finder according to claim 1, wherein the zoom lens camera is stopped after being driven beyond the finder system backlash in a direction opposite to a direction in which the entire moving means is driven. A movable barrel that supports and moves the front group lens, the rear group lens, and the rear group moving unit as a unit, and a rear lens group that supports the rear group lens and is driven relative to the front group lens by the rear group moving unit. A supporting lens barrel,
Detecting means for detecting a focal length according to the position of the movable barrel;
The whole moving means further includes a whole moving motor, a gear mechanism that transmits the rotation of the whole moving motor, and a barrel feeding mechanism that feeds the movable barrel through the gear mechanism,
The zoom lens camera provided with the zoom finder according to claim 1, wherein the finder interlocking means is driven by the gear mechanism. The zoom system backlash when moving the front group lens, the rear group lens, and the rear group moving means by the whole moving means includes a gear train backlash when the whole moving motor drives the gear mechanism, and the gear This is the sum of the lens barrel backlash when the mechanism drives the lens barrel feeding mechanism and the detection backlash of the detecting means for detecting the focal length based on the position of the movable lens barrel, and is used when the zoom finder is scaled. finder system backlash, the gear train backlash and a zoom lens camera having a zoom finder according to claim 3, wherein the sum of the finder backlash of the viewfinder interlocking means.

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