JP2010169734A - Lens device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a so-called retractable lens barrel which has improved optical performance by preventing relative tilt to an optical axis and enhancing decentration accuracy in a photographing optical system comprising a plurality of lens groups, and to provide a photographing device. <P>SOLUTION: A plurality of lens barrels holding the lens groups are connected by a so-called key way structure. It has a backlash-removing structure where the lens barrels are biased by a spring. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention improves the relative tilting and decentering accuracy with respect to the optical axis by connecting a plurality of barrels holding the lens group in a photographing optical system composed of a plurality of lens groups with a so-called key groove structure, The present invention relates to a so-called collapsible lens barrel and a photographing apparatus in which optical performance is improved by a backlash removing structure in which each barrel is biased with a spring.

A digital still that uses a silver halide film to take a photo, and forms an optical image on an image sensor such as a CCD, electrically reads the image information, and records it on a recording medium such as a memory. 2. Description of the Related Art Conventionally, a photographing apparatus such as a camera employs a lens barrel called a so-called collapsible structure, whose optical total length when not photographing is shorter than that during photographing, thereby reducing the size of the photographing apparatus. In recent years, with the increase in the number of pixels, miniaturization, and magnification of the optical system, the sensitivity of each lens group to tilting and decentering has increased, and it has become necessary to increase the accuracy of the lens barrel holding structure. The structure of the lens barrel holding structure is becoming more complicated due to the structure for improving the relative eccentricity of the lens barrels by connecting the key of one lens barrel and the groove of the other lens barrel. (Patent Document 1)
In addition, due to high magnification (6 times to 10 times or more), the optical total length at the time of photographing is extended, and cylindrical members such as a lens barrel for holding the optical system and a cam ring for moving the lens barrel to a desired optical position In order to reduce the overall optical length (collapse) by retracting the tube member during non-photographing, the tube member is retracted more than before, and a more complicated lens barrel holding structure is required. Need to be done without interfering with.
JP 2002-906190 A

  However, in order to retract the lens barrel with a complicated and elongated structure as much as possible without interfering with the holding structure of the other lens barrel, in order to avoid interference with the complicated and elongated lens barrel. Therefore, it is very difficult to satisfy the functions in the limited barrel diameter and the barrel structure.

In order to solve the above problems, the lens device of the present invention is:
A first lens holding member, a second lens holding member, and a third lens holding member supported so as to be capable of moving back and forth along the optical axis;
Engage with each of the first cam follower members installed on the third lens holding member,
A first cam portion for moving the third lens holding member forward and backward along the optical axis to a predetermined position, and a cam member supported rotatably.
The guide key installed on the second lens holding member that engages with the guide groove installed on the first lens holding member and the first cam follower member are in phase with each other on the circumference around the optical axis. It is characterized by being.

  As described above, according to the present invention, even when the lens holding member has a complicated holding structure and an extended total length, the total length and the lens barrel diameter of the lens apparatus when retracted can be reduced. .

  Next, details of the present invention will be described in accordance with the description of the embodiments.

  Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. FIGS. 1 to 14 show a so-called collapsible lens barrel that has a variable magnification optical system having a four-group configuration, and in a non-use state, the distance between the lens groups is shortened compared with that during normal use, thereby greatly reducing the total lens length. FIG. 1 is an exploded perspective view, FIG. 2 is a cross-sectional view when the main part is retracted, FIG. 3 is a cross-sectional view when the main part is at the widest angle (WIDE end), and FIG. 4 is a main part. FIG. 5 is a perspective view of the first group unit and the second group unit at the time of TELE of the embodiment, and FIG. 6 is a perspective view of the second group unit and the third group unit at the time of WIDE of the embodiment. 8 is a perspective view of the moving cam ring and the fixed cylinder of the embodiment, FIG. 9 is a front view of a vibration isolating mechanism configured in the shift unit, and FIG. 7 is a development view of the inner cam of the moving cam ring of the embodiment. FIG. 10 is a development view of the inner cam of the fixed cam ring of the embodiment, and FIG. FIG. 12 is a cross-sectional view of the shift unit, FIG. 13 is a system diagram of a photographing apparatus equipped with the lens barrel of this embodiment, and FIG. 14 is a simplified diagram illustrating the basic configuration of this embodiment. FIG. 15 is a perspective view of the first group unit and shift unit in the retracted state of the present embodiment, and FIG. 16 is a front view of the first group unit and shift unit of the present embodiment.

  L1 is a first lens group, L2 is a second lens group, L3 is a third lens group that moves in a plane perpendicular to the optical axis and performs a shake correction operation, and L4 is in focus operation by moving in the optical axis direction. This is a fourth lens group that performs. Reference numeral 1 denotes a first group unit that is a first lens holding member that holds the first lens group L1, and reference numeral 2 denotes a second group unit that is a second lens holding member that holds the second lens group L2. 3 is a shift unit that is a third lens holding member that allows the third lens group L3 to move within a plane perpendicular to the optical axis, 4 is a 4 group unit that holds the fourth lens group L4, and 5 is the amount of light. A diaphragm shutter unit 6 for adjusting the cam, a cam pin 6 being a first cam follower member having a conical cam follower fixed to the rear end portion of the shift unit 3 by press-fitting or bonding, etc., 8 and 9 are four groups It is a guide bar as a guide rod that supports the unit 4 so as to be movable in the optical axis direction. Reference numeral 11 denotes a CCD holder for positioning and fixing the rear ends of the guide bars 8 and 9 and further mounting an image pickup device such as a CCD. Reference numeral 12 denotes a rear barrel for positioning and fixing the front end portions of the guide bars 8 and 9, and the CCD holder 11 and the rear barrel 12 are fixed by three screws. Reference numeral 16 denotes a focus motor serving as a drive source for moving the fourth group lens barrel back and forth along the optical axis direction. A rack 17 is screwed into a lead screw 16a that rotates coaxially with the rotor of the focus motor 16, and the lead screw rotates. The movement is converted into the straight drive of the fourth group unit 4. The focus motor 16 is fixed to the rear barrel 12 with two screws. Reference numeral 18 denotes a rack spring that biases the backlash between the fourth group unit 4 and the rack 17. Reference numeral 35 denotes a photo interrupter for detecting the initial position of the fourth group unit 4. When the shape of the fourth group lens tube crosses the photo interrupter 35, the light interrupt / transmission of the photo interrupter is switched to detect the initial position.

  Reference numeral 13 denotes a fixed cam ring, which is engaged with a cam groove 13a for moving the moving cam ring 7 forward and backward in the optical axis direction and a key 10h installed on the fixed cylinder 10, so that the fixed cylinder 10 is offset from the optical axis. A guide groove 13b for positioning the core and guiding it straight is provided. The fixed cam ring 13 is fixed to the CCD holder 11 with four screws. Reference numeral 7 denotes a moving cam ring. The cam groove 7c, which is a second cam portion for moving the first group unit 1, the second group unit 2 and the shift unit 3 forward and backward along the optical axis, A cam groove 7b which is a cam portion and a cam groove 7c which is a first cam portion are provided. The movable cam ring 7 is integrally regulated in the optical axis direction by a fixed cylinder 10 and a bayonet structure (not shown), and is linearly guided by a key 10h and a guide groove 13b. The movable cam ring 7 is an outer shape of the fixed cylinder 10. It can advance and retreat in the optical axis direction while rotating about the axis. Reference numeral 14 denotes a Naruto gear that requires a predetermined length so as to be screwed into a gear portion installed on the moving cam ring 7 and to be continuously screwed in the driving range of the moving cam ring 7. The Naruto gear 14 rotates at a fixed position around the Naruto gear shaft 15 sandwiched between the fixed cam ring 13 and the CCD holder 11. The zoom motor unit 28 is fixed to the CCD holder with three screws, and an output gear (not shown) installed in the zoom motor unit 28 and the Naruto gear 14 are screwed together to move the power of the zoom motor unit 28 via the Naruto gear 14. It is configured to transmit to the cam ring 7.

  The cam groove 13a installed in the fixed cam ring 13 is engaged with the cam pin 27 installed in the moving cam ring 7. The cam groove 7a installed in the moving cam ring 7 is connected to the first unit 1 described later. The cam pin 25 that is the second cam follower member installed is the cam pin 26 that is the third cam follower member installed in the second group unit 2 in the cam groove 7b, and the shift unit is the cam groove 7c. The cam pins 6 that are the first cam follower members installed in 3 are engaged with each other, and the moving cam ring 7 that is the cam member is moved forward and backward along the optical axis and centered on the optical axis. The first group unit 1, the second group unit 2, and the shift unit 3 are moved forward and backward relative to each other along the optical axis to perform a zooming operation and retract the entire lens barrel.

  At this time, the cam pins installed in the first group unit 1, the second group unit 2, and the shift unit 3 may be formed integrally with each lens barrel, or another member such as a metal may be used as in this embodiment. It may be fixed by press-fitting or adhesion.

  Next, the details of the support structure of the first group unit 1, the second group unit 2, and the shift unit 3 will be described.

  As shown in FIG. 11, the cam pin 25 disposed near the rear end of the first unit 1 passes through the guide grooves 10a, 10b, and 10c (see FIG. 8) that are evenly installed in the fixed cylinder 10 at 120 ° to move the cam. It engages with a cam groove 7 a installed on the inner diameter of the ring 7. At that time, guide keys 1c and guide grooves 10a, 10b, and 10c arranged at three positions equally 120 ° near the rear end of the first unit 1 are engaged with each other, and the first unit 1 is eccentric with respect to the fixed cylinder 10. The position is decided.

  Similarly, guide keys 2c arranged at three positions equally 120 ° in the vicinity of the rear end of the second group unit 2 are engaged with the guide grooves 10a, 10b, and 10c, respectively, and the second group unit 2 is eccentric with respect to the fixed cylinder 10. The position is decided. The first group unit 1 and the second group unit 2 are each positioned by the same guide groove provided in the fixed cylinder 10 to enhance the eccentricity accuracy with respect to each optical axis. Similarly, in the shift unit 3, the three guide keys 3 a respectively engage with the guide grooves of the fixed cylinder 10. As shown in FIG. 8, the guide grooves that determine the eccentric positions of the first group unit 1 and the second group unit 2 Are eccentrically positioned in the guide grooves 10d, 10f, and 10g (see FIG. 8) having different phases of 60 °.

Here, the cam pins 25 of the first group unit 1 are metal members, and all of the three portions are press-fitted and fixed to the first group unit 1. Two of the three cam pins 6 of the shift unit 3 are the same plastic members as the lens barrel, and are integrally molded with the lens barrel. However, at one place, the cam pin 6 can be biased with respect to the shift unit 3 without play by the coil spring 6a. Two portions of the cam pins 26 of the second group unit 2 are press-fitted and fixed by metal members, and one portion is equipped with a biasing mechanism by a coil spring 26a. (See Fig. 2 and Fig. 12)
As shown in FIGS. 5, 2, 3, and 4, the guide groove 1 a is a guide groove that is installed at three positions equally at 120 ° on the inner diameter of the first group unit 1 and the vicinity of the front end of the second group unit 2. The keys 2b, which are guide keys installed at three locations equally at 120 °, are combined, and the optical axes of the first group unit 1 and the second group unit 2 are forced to coincide with each other. It has become. Similarly, three guide grooves 2d are equally installed at 120 ° equally on the inner diameter of the second group unit 2, and the keys 3b and the guide grooves 2d arranged at three equal 120 ° positions on the front end of the shift unit are combined. In addition, the optical axes of the second group unit 2 and the shift unit 3 are forcibly matched. These keyway alignments always function in shooting and retracted states including TELE and WIDE. For example, in TELE when the distance between the first group unit 1 and the second group unit 2 is maximum. Similarly, the arrangement can be combined.

  With the configuration described above, the first group unit 1, the second group unit 2, and the shift unit 3 are restricted in rotation by the fixed cylinder 10, and are relatively aligned along the cam grooves 7a, 7b, and 7c of the inner diameter of the rotating moving cam ring 7. It can be moved forward and backward.

  FIG. 15 is a perspective view showing the configuration of the first group unit 1, the second group unit 2, and the shift unit 3 when retracted.

  With the above-described configuration, the first group unit 1, the second group unit 2 are along the guide grooves 10a, 10b, and 10c, and the shift unit 3 is along the guide grooves 10d, 10f, and 10g, and each is a shooting position that has become a cam. Move to. When the retracted state as shown in FIG. 15 is obtained, the cam pin 6 of the shift unit 3 enters the width of the guide groove 1 a installed in the first group unit 1.

  The guide groove 1a engages with the key 2b and performs the function of relative eccentric positioning of the first group unit 1 and the second group unit 2. This function is performed using the circumferential width of the guide groove 1a. Even if the first group unit 1 is cut out and the guide groove 1a can be seen, this positioning function is not impaired.

  Even in the retracted state, the guide groove 1a and the key 2b are engaged, but since the key 2b has moved to the object side of the guide groove 1a, the cam pin 6 enters the width of the guide groove 1a when retracted. Of course, they do not interfere with each other.

  As shown in FIG. 16, the cam pins 25 that are the second cam follower members of the first unit 1 are arranged equally 120 ° in three directions, and the cam pins 6 of the shift unit 3 are out of phase with the cam pins 25 by 60 °. Composed of position. This is due to the cam arrangement of the movable cam ring 7 (see FIG. 7). When the cam arrangement of the moving cam ring 7 is taken into consideration, the cam of the shift unit 3 is different in phase with respect to the first group unit 1 and the second group unit 2 in the movement trajectory of the first group unit 1, the second group unit 2 and the shift unit 3. Arrangement is efficient for downsizing both as the inner surface area and the entire length of the movable cam ring 7. In such a cam pin configuration of each unit, the guide groove 1a installed in the first group unit 1 (not shown in FIG. 16) and the key 2b installed in the second group unit are arranged in the same phase as the cam pin 6 of the shift unit 3. A configuration in which the cam pin 6 enters the width of the guide groove 1a described above can be realized.

  Here, the variable magnification optical system having a four-lens unit configuration as in this embodiment has a large variable magnification (for example, 6 times, particularly 10 times or more), and the positional accuracy required for each lens unit is particularly high. In order to maintain the performance, in addition to the above highly accurate lens holding and biasing configuration, the first lens unit L1 is configured to be adjustable in the optical axis direction and the optical axis orthogonal direction.

  The optical adjustment mechanism of the first group barrel 22 that holds the first lens group L1 will be described below.

In FIG. 1, reference numeral 1 b denotes a first group barrel receiving surface installed on the inner diameter of the first group unit 1. A contact surface (not shown) of the first group barrel 22 abuts against the first group barrel receiving surface 1b, and determines the position of the first group unit 1 in the optical axis direction. The first group lens barrel receiving surface 1b is provided at three positions equally 120 °. In the present embodiment, the first group barrel 22 is decentered on a plane orthogonal to the optical axis on the first group barrel receiving surface 1b, and fixed at a predetermined position where appropriate optical performance can be secured. When the adjustment is performed, the shooting state of the lens is TELE. In the optical system of the present embodiment, this is performed in order to appropriately adjust the one-side blur at the time of TELE. In the present embodiment, adhesion is performed in the adjusted method for fixing the lens barrel, but welding or screwing may be used as long as the first group lens barrel 1 can be fixed. Here, the first lens barrel receiving surface 1b is a flat surface, but may be a slope or a curved surface when tilting / tilting adjustment is performed instead of eccentricity adjustment. The first group barrel receiving surface 1b is formed in a plurality of steps having different positions in the optical axis direction, and the position in the optical axis direction can be selected stepwise by rotating the first group barrel 22. It has become. At this time, the first group barrel 22 is configured to be pressed against the first group barrel receiving surface 1b by a first group barrel urging spring 23 fixed to the first group barrel 22. (See Figure 4)
In the assembly of the first unit 1, the above optical adjustment is performed, and then a dust-proof rubber 21 for preventing dust from entering into the lens barrel in FIG. 1 is incorporated, and the front mask 19 is fixed using the front mask sheet metal 20. To do.

  A decorative ring (not shown) is attached to all end faces of the front mask by adhesion or double-sided tape.

  Here, as described above, in this embodiment, the optical adjustment at the time of TELE is performed in order to obtain an appropriate optical performance. For example, when the lens is faced upward, the lens barrel has a backlash in the horizontal state. There is a case in which the optical performance changes due to a change in the offset.

  However, in this embodiment, the force of the coil spring 26a that urges the cam pin 26 mounted on the second group unit 2 is applied to the cam pin 6 mounted on the shift unit 3 via the key 2b and the guide groove 1a. The force of the coil spring 6a that biases the first group unit 1 is transmitted to the first group unit 1 via the key 3b and the guide groove 2d, and the force that biases the first group unit 1 to the moving cam ring 7 is applied. . These urging structures make it possible to maintain the optical performance obtained by adjustment even if the posture of the lens unit changes. Details of this configuration will be described later.

  Next, the cam locus of each group will be described. FIG. 7 is a cam development view of the inner diameter of the movable cam ring 7. FIG. 10 is a cam development view of the inner diameter of the fixed cam ring 13.

  The moving cam ring 7 has a structure in which cam pins 27 arranged at three positions equally 120 ° on the moving cam ring 7 are engaged with the cam groove 13a of FIG. 10 and extended from collapsing to WIDE to TELE. At this time, the cam groove 13a is a flat cam at the retracted, WIDE, and TELE positions.

  Further, the first group unit 1 is configured such that cam pins 25 arranged at three positions equally to the first group unit 1 at 120 ° are engaged with the cam grooves 7a of FIG. However, since the moving cam ring 7 also moves, it moves to the optical position determined by the combined cam of the two cam rings. In the present embodiment, since the movable cam ring 7 is extended from the collapsed state to the TELE, the first group unit 1 is configured to be extended. At this time, the cam groove 7a is a flat cam at the retracted, WIDE, and TELE positions.

  Further, the second group unit 2 is configured such that cam pins 26 arranged at three positions equally to the second group unit 2 at 120 ° are engaged with the cam groove 7b in FIG. 7 and retracted from the retracted state to WIDE, and retracted from WIDE to TELE. It has become. However, since the moving cam ring 7 also moves, it moves to the optical position determined by the combined cam of the two cam rings. In the present embodiment, the second group unit 2 is temporarily extended to the WIDE position, and at the TELE position, the second group unit 2 is moved to the optical position where the second group unit 2 is retracted as compared with WIDE.

  Further, in the third group unit 3, cam pins 6 arranged at three positions at 120 ° equally to the third group unit 3 are engaged with the cam groove 7c of FIG. It is a structure that temporarily retracts and TELE extends compared to WIDE. However, since the moving cam ring 7 also moves, it moves to the optical position determined by the combined cam of the two cam rings. In the present embodiment, the shift unit 3 moves to the optical position where the shift unit 3 is drawn out by telescoping = TELE.

  In the present embodiment, the cam trajectory is described above. However, different cam trajectories that can achieve the amount of movement of each group and the distance between groups depending on the optical type may be used.

  In this embodiment, the cam flat portion is provided at the retracted, WIDE, and TELE positions. However, the cam locus may be configured without the flat portion.

  7d in FIG. 7 is a cam introduction port for introducing the cam pin 25 of the first group unit 1 and the cam pin 26 of the second group unit 2 and the cam pin 6 of the shift unit into the cam groove.

  Reference numeral 13c in FIG. 10 denotes a cam introduction port for introducing the cam pin 27 of the moving cam ring into the cam groove.

  As described above, in this embodiment, the zoom operation from collapsing ⇒ WIDE ⇒ TELE causes the power of the zoom motor unit 28 to rotate the moving cam ring 7 via the Naruto gear 14 to move the moving cam ring 7 itself and the first group. The unit 1, the second group unit 2, and the shift unit 3 are moved in the optical axis direction. At this time, the light shielding fin 2a in FIG. It is detected by a change in electrical output due to light passing through and being blocked. In the present embodiment, it is performed at a predetermined position between collapsing ⇒ WIDE. However, in the cam trajectory configuration in which no flat portion is provided in the above described collapsing, WIDE, and TELE, the position is further extended than TELE. It is also possible to detect at a position further retracted than the retracted. At the time of shooting, this photo interrupter 36 is set as an initial position, and a control function that can detect and count pulses by a pulse generation mechanism (not shown) built in the zoom motor unit 28 and can stop at any position from WIDE to TELE. have.

  As a pulse generation mechanism at this time, a method in which a so-called pulse plate is combined with a photo interrupter or a photo reflector, a method using a step motor, or the like may be used. Also, a system may be used in which a scale is attached to the second group unit 2 or other moving group, and the amount of displacement is detected magnetically and optically.

  FIG. 14 is a simplified diagram illustrating the main points of the configuration of the present embodiment.

  FIG. 14A) shows the relative positional relationship along the optical axis of the first group unit 1, the second group unit 2, and the shift unit 3 during TELE imaging.

  FIG. 14B) shows the relative positional relationship along the optical axis of the first group unit 1, the second group unit 2, and the shift unit 3 during WIDE shooting.

  As described above, the keys, grooves, and cam pins installed in each unit are originally equally arranged at 120 ° in different phases on the lens barrel diameter, but this embodiment will be described in this figure. Therefore, it is a simplified diagram in which keys, grooves, and cam pins are arranged at 180 ° diagonal positions in the same cross section.

  At the time of WIDE shooting in FIG. 14b), the first group unit 1 tends to fall in the direction of F1 around the cam pin 25 due to the weight of the lens barrel or the lens. Since the key 2b is engaged at the position M2 from the cam pin 25 to the object side with respect to the guide groove 1a installed on the inner diameter of the first group unit 1, the second group unit 2 is similar to the first group unit 1. The cam pin 26 tends to fall down in the direction of f1. At this time, the cam pin 26 also falls in the direction of f4, and the cam pin 26 tries to drop out of the cam groove while compressing the coil spring 26a along the taper of the cam groove. However, a force biased by the coil spring 26a to the cam groove is applied to the cam pin 26. Therefore, a force that pushes back the falling of the cam pin 26 acts, and this force acts to push back a series of falls.

  Further, the second unit 2 falls in the direction of f1 around the cam pin 26, and the object side of the cam pin 26 falls in the direction of f2. At this time, since the key 3b is engaged at the position N2 from the cam pin 26 to the image plane side with respect to the guide groove 2d installed on the inner diameter of the second group unit 2, the shift unit 3 is centered on the cam pin 6. It falls in the direction of f3. Then, the cam pin 6 falls in the direction of f5 and tries to drop out from the cam groove along the taper of the cam groove while compressing the coil spring 6a. However, the cam pin 6 is subjected to a force biased by the coil spring 6a to the cam groove. Therefore, a force that pushes the cam pin 6 off is applied, and this force causes a force to reverse a series of falls.

  Next, at the time of TELE photographing in FIG. 14a), the first group unit 1 falls in the direction of K1 around the cam pin 25 due to the weight of the lens barrel and the lens, and falls in the direction of k2 on the object side from the cam pin 25. Since the key 2b is engaged at the position M1 from the cam pin 25 to the image plane side with respect to the guide groove 1a installed on the inner diameter of the first group unit 1, the second group unit is opposite to the first group unit 1. 2 tends to fall in the direction of k3 around the cam pin 26. At this time, the cam pin 26 also falls in the k5 direction, and the cam pin 26 tends to fall out of the cam groove while compressing the coil spring 26a along the taper of the cam groove. However, a force biased by the coil spring 26a to the cam groove is applied to the cam pin 26. Therefore, a force that pushes back the falling of the cam pin 26 acts, and this force acts to push back a series of falls.

  Further, the second group unit 2 falls in the direction of k3 around the cam pin 26. At this time, since the key 3b is engaged at the position N1 from the cam pin 26 to the object side with respect to the guide groove 2d installed on the inner diameter of the second group unit 2, the shift unit 3 is centered on the cam pin 6 and k4. Falls in the direction of. Then, the cam pin 6 falls in the direction of k6 and attempts to drop off from the cam groove along the taper on the k6 side of the cam groove while compressing the coil spring 6a. However, the cam pin 6 is subjected to a force biased by the coil spring 6a to the cam groove. Therefore, a force that pushes back the falling of the cam pin 6 acts, and this force acts to push back a series of falls.

  As described above, whether the TELE or the WIDE is the first group unit, the resultant force of the coil spring 26a installed in the second group unit 2 and the urging force of the coil spring 6a installed in the shift unit 3 is as follows. It plays the function of preventing 1 fall.

  The relationship between the distances M1 and M2 of the key 2b with respect to the cam pin 25 and the distances N1 and N2 of the key 3b with respect to the cam pin 26 is as follows.

M2> M1 (1)
N1> N2 (2)
The greater these distances, the greater the collapse of each unit and the greater the amount of compression of the coil spring.

  In this embodiment, with the magnification change operation from WIDE to TELE, M2 decreases as the key 2b approaches the cam pin 25, and the key 2b becomes M1 through a minimum value near the same position as the cam pin 25. Therefore, the pushing back force of the coil spring 26a due to the fall of the second group unit 2 decreases. N2 increases to N1 when the key 3b moves away from the cam pin 26 through a minimum value near the same position as the cam pin 26. That is, the urging forces of the coil spring 26a and the coil spring 6a can complement each other and obtain a desired urging force (= a force to push back the fall) in any photographing state.

  FIG. 13 is a system diagram of driving of the lens barrel of the photographing apparatus equipped with a lens barrel having a blur correction function and blur correction. 3, 51 is an optical low-pass filter for removing the high frequency component of the spatial frequency of the subject, and 50 is an image sensor for converting an optical image arranged on the focus surface into an electric signal. An electrical signal a read from a certain CCD or CCD 50 is converted into an image signal b by the camera signal processing circuit 52. A microcomputer 53 controls lens driving. When the power is turned on, the microcomputer 53 monitors the outputs of the focus reset circuit 54 and the zoom reset circuit 55, and rotates the respective motors by the focus motor drive circuit 56 and the zoom motor drive circuit 57 so that each lens group is aligned in the optical axis direction. Move to. The outputs of the focus reset circuit 54 and the zoom reset circuit 55 come to the predetermined positions where the respective movable members are set in advance (the light shielding member provided on the movable member shields the light emitting portion of the photo interrupter provided on the fixed portion, Or when the focus is counted, the focus is counted in the microcomputer 53 after the stepping motor is driven, and the zoom is performed with the built-in pulse plate and photo interrupter ( By counting the pulse output (not shown) by the microcomputer 53, the microcomputer 53 can know the absolute position of each lens group. Thereby, accurate focal length information is obtained. This series of operations is referred to as zoom and focus reset operation.

  Reference numeral 58 denotes an aperture driving circuit for driving the aperture device 13, and the area of the aperture diameter 106 (FIG. 12) of the aperture and the ND (not shown) based on the brightness information b of the video signal captured by the microcomputer 53. The light quantity adjustment function such as the amount of engagement of the filter is controlled. In this embodiment, an example in which a CCD is used as an image sensor is shown, but a CMOS may be used.

  Reference numerals 59 and 60 denote PITCH (vertical tilt angle) and YAW (horizontal tilt angle) angle detection circuits of the optical device. The angle detection is performed by, for example, outputting the output of an angular velocity sensor such as a vibration gyroscope fixed to the photographing apparatus. It is done by integrating. The outputs of both circuits 59 and 60, that is, the information on the tilt angle of the photographing apparatus is taken into the microcomputer 53. Reference numerals 61 and 62 denote PITCH (vertical direction) and YAW (horizontal direction) coil drive circuits for moving the third lens unit L3 perpendicularly to the optical axis in order to perform blur correction. The magnet 103b in FIG. 106b and yokes 104b and 105b, the coil 101b is arranged in the gap of the magnetic circuit, and a driving force for shifting the third group lens barrel 102 on which the third lens unit L3 is mounted is generated by a so-called moving coil configuration. Reference numerals 63 and 64 denote PITCH (vertical direction) and YAW (horizontal direction) position detection circuits for detecting the shift amount of the third lens unit L3 with respect to the optical axis. When the third lens unit L3 moves perpendicularly to the optical axis, the passing light beam is bent and the position of the subject image formed on the CCD 50 moves. By controlling the amount of movement of the image at this time by the microcomputer 53 so that the moving amount is the same as the moving direction of the image when the photographing device is actually tilted, Even so, a so-called blur correction in which the image being formed does not move can be realized. In the microcomputer 53, the tilt signal of the photographing apparatus obtained by the PITCH angle detection circuit 59 and the YAW angle detection circuit 60 and the shift amount signal of the third lens unit L3 obtained from the PITCH position detection circuit 63 and the YAW position detection circuit 64 are obtained. Are respectively subtracted and the third lens group L3 is driven by the PITCH coil driving circuit 61 and the YAW coil driving circuit 62 with the signals obtained by amplifying the respective difference signals and performing appropriate phase compensation. By this control, positioning control is performed so that the above difference signal becomes smaller, and the target position is maintained. Further, in this embodiment, since the zooming operation is performed by the relative movement of the first to third lens units, the image movement amount with respect to the shift amount of the third lens unit L3 changes depending on the focal length. The shift amount of the third lens unit L3 is not determined as it is based on the tilt signal of the photographing apparatus obtained by the angle detection circuit 59 and the YAW angle detection circuit 60, and the movement of the image due to the tilt of the photographing apparatus is corrected by correcting the focal length information. It is configured to cancel by shifting the third lens unit L3.

  Although the above is description of an Example, this invention is not limited to the structure of an Example, What kind of thing may be sufficient if it is the structure shown by the claim.

The exploded perspective view of a present Example. Sectional drawing at the time of collapse of a present Example. Sectional drawing at the time of the widest angle (WIDE end) of a present Example. Sectional drawing at the time of the maximum telephoto (TELE end) of a present Example. The perspective view of the 1st group unit at the time of TELE of a present Example, and a 2nd group lens barrel. The perspective view of the 2nd group lens barrel at the time of WIDE of a present Example, and a 3rd group lens barrel. The expanded view of the inner cam of the moving cam ring of a present Example. The perspective view of the moving cam ring and guide cylinder of a present Example. The front view of the vibration proof mechanism comprised in a shift unit. The expanded view of the inner cam of the fixed cam ring of a present Example. The 1st group unit and 2 group unit support block diagram by the fixed cylinder of a present Example. Sectional drawing of a shift unit. 1 is a system diagram of a photographing apparatus equipped with a lens barrel of the present embodiment. BRIEF DESCRIPTION OF THE DRAWINGS The simplified diagram explaining the main points of the configuration of the present embodiment. FIG. 3 is a perspective view of the first unit and the shift unit when retracted according to the present embodiment. The front view of the 1st group unit of this example, and a shift unit.

1 Group 1 unit 1a Guide groove 2 Group 2 unit 2b Key 2d Guide groove 3 Shift unit 3b Key 6 Cam pin 6a Coil spring 7 Moving cam ring 10 Fixed cylinder 13 Fixed cam ring 25 Cam pin 26 Cam pin 26a Coil spring

Claims (3)

A first lens holding member, a second lens holding member, and a third lens holding member supported so as to be capable of moving back and forth along the optical axis;
Engage with each of the first cam follower members installed on the third lens holding member,
A first cam portion for moving the third lens holding member forward and backward along the optical axis to a predetermined position, and a cam member supported rotatably.
The phase of the guide key installed on the second lens holding member that engages with the guide groove installed on the first lens holding member and the circumference of the first cam follower member around the optical axis. A lens device characterized by matching. The lens device according to claim 1, wherein the cam member is
A second cam portion for engaging with a second cam follower member installed on the first lens holding member and for moving the first lens holding member forward and backward along the optical axis to a predetermined position,
A third cam portion that engages with a third cam follower member installed on the second lens holding member, and advances and retracts the second lens holding member to a predetermined position along the optical axis; A lens device.   2. The lens device according to claim 1, wherein the first cam follower member can enter the guide groove when the first lens holding member and the third lens holding member advance and retract. A lens device.