JP2000131729A - Image pickup device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize a diaphragm device arranged inside a lens barrel. SOLUTION: As to the driving device of a light quantity adjusting device by which a pair of light quantity adjusting members 88 and 89 slides in a direction orthogonally crossing with an optical axis, so that diameter is changed; a magnetic circuit constituted of a coil 83 wound to a bobbin, a yoke 84, and a magnet 87 is used, and the members 88 and 89 are driven by an arm 86 provided on the magnet 87, the coil 83 is arranged on one of the sides sandwiching the center of the optical axis in the sliding direction of the members 88 and 89, and also the magnet 87 is arranged on the other side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light amount adjusting device suitable for a retractable zoom camera and an imaging device having a lens barrel driving device.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 18, for example, there has been proposed a light amount adjusting device for changing a diameter of an opening by sliding a plurality of light amount adjusting members.

[0003] 201 is a coil wound around a bobbin.
Reference numerals 202 and 203 denote yokes, and reference numeral 204 denotes an arm provided integrally with a magnet 205. When the arm rotates, the light amount adjusting members 206 and 207 are slid and driven to change the opening diameter.

In recent years, an image pickup apparatus having a solid-state image pickup device such as a video camera or an electronic still camera has a rear focus lens for miniaturization thereof, and the lens drive means is generally used as an image pickup apparatus. Usually, a circular step motor is used.

[0005]

In the prior art example of the light amount adjusting device, the magnetic circuit composed of the coil, yoke and magnet is arranged in a concentrated manner at a position deviated from the optical axis. There were restrictions on the cylinder layout. In particular, it is difficult to reduce the size of a zoom lens barrel, which is commonly used in recent years, and drives a lens group by combining cylindrical members, such as a retractable zoom lens barrel. Was.

Further, a small lens driving means or the like suitable for a rear focus type lens system, particularly suitable for a retractable zoom lens barrel, has not been proposed so far.

[0007]

The invention according to claim 1 is
A plurality of light amount adjusting members guided slidably in a direction perpendicular to the optical axis, a magnetic circuit including a coil, a yoke, and a magnet, and the light amount adjusting member provided on the magnet and rotating integrally therewith. And a coil and a magnet constituting the magnetic circuit are disposed to face each other with the optical axis interposed therebetween, and the magnetic circuit is arranged in a direction substantially orthogonal to the optical axis. It is characterized by extending along.

In this configuration, particularly for a retractable zoom lens barrel in which a lens group is driven by combining a cylindrical member, the zoom lens barrel is disposed inside the cylindrical member, and is arranged in the optical axis direction. Even when the apparatus is configured to move, the apparatus can be arranged without increasing the size.

According to a second aspect of the present invention, there is provided a feeder having a lens barrel movably provided in an optical axis direction, a guide member for guiding the lens barrel in a straight line, and a screw portion for moving the lens barrel. A screw, a driving unit that rotationally drives the feed screw, an imaging element that converts imaged image information into an electric signal, and a holding member that holds the imaging element, wherein the driving unit includes: A magnet provided integrally with the feed screw, and a magnetic circuit including a plurality of coils and a yoke linearly opposed to each other with the magnet interposed therebetween, wherein the magnetic circuit includes one side of the holding member. Characterized by being arranged along.

In this configuration, by arranging the driving means along one side of the image sensor, the size of the apparatus can be reduced, and the integration density of components can be increased.

According to a third aspect of the present invention, a plurality of light amount adjusting members guided slidably in a direction perpendicular to the optical axis;
A magnetic circuit having a coil, a yoke, and a magnet; and an arm provided on the magnet and driving the light amount adjusting member that rotates integrally, the coil and the magnet constituting the magnetic circuit sandwiching an optical axis. A screw portion for moving the lens barrel movable in the optical axis direction while being opposed to each other and guided in a straight line by a light amount adjusting device and a guide member in which the magnetic circuit extends along a direction substantially orthogonal to the optical axis. It is composed of a plurality of coils and yokes linearly opposed to each other with a magnet provided integrally with the feed screw having the magnets, and converts the image information in which the magnets, coils and yokes are imaged into electric signals. Driving means for rotating and driving the feed screw disposed along one side of a holding member for holding the image pickup device. That.

According to a fourth aspect of the present invention, there is provided an image pickup apparatus wherein the direction of opposition between the coil and the magnet of the magnetic circuit is made to coincide with the sliding direction of the light amount adjusting member.

According to a fifth aspect of the present invention, the driving means includes:
In the imaging apparatus, the lens barrel does not interfere with the lens barrel in the optical axis direction when the lens barrel is closest to the image sensor.

According to a sixth aspect of the present invention, the longitudinal direction of the magnetic circuit of the light amount adjusting device and the longitudinal direction of the driving means are made to coincide with each other.

In this configuration, the longitudinal direction of the magnetic circuit of the light amount adjusting device and the longitudinal direction of the driving means are matched with each other,
The overall length at the time of collapsing can be shortened, and the device can be downsized.

The invention according to claim 7 is characterized in that the light amount adjusting device is disposed in a lens barrel.

The invention according to claim 8 is characterized in that the lens barrel is configured to extend forward from a retracted position in the apparatus main body.

[0018]

FIG. 19 is a sectional view showing an optical arrangement according to an embodiment of the present invention. In the present embodiment, there are three lens groups, a first lens group having a negative refractive power, a second lens group having a positive refractive power, and a third lens group having a positive refractive power, in order from the object side. During zooming from the wide-angle end to the telephoto end, the first unit moves reciprocatingly to the image side, the second unit moves toward the object side, and the third unit moves during zooming.

In this embodiment, a so-called wide-angle short zoom system is basically constituted by the first negative lens unit and the second positive lens unit, and zooming is performed by moving the second positive lens unit. The movement of the image point due to the magnification change is corrected by reciprocating the negative first lens unit. The third positive lens unit is responsible for increasing the refractive power of the photographing lens due to the downsizing of the image sensor, and particularly forms the first lens unit by reducing the refractive power of the short zoom system composed of the first and second lens units. Suppressing the occurrence of aberrations in the lens to achieve good optical performance. Particularly, telecentric imaging on the image side required for a photographing apparatus using a solid-state imaging device or the like is achieved by making the positive third group function as a field lens.

Further, the stop is placed closest to the object side of the second lens group, and the distance between the entrance pupil and the first lens group on the wide-angle side is reduced, thereby increasing the outer diameter of the lens constituting the first lens group. In addition, good optical performance can be obtained without increasing the number of components by canceling off-axis aberrations in the first and third lens units with the apertures disposed on the object side of the two positive lens units.

Further, in the present embodiment, the negative first group is composed of two concave lenses 4 and 5 having concave surfaces facing the image side and a convex lens 6 having a convex surface facing the object side in order from the object side. , The positive second group is composed of three lenses, that is, a convex lens 10, a concave lens 11, and a convex lens 12, in that order from the object side, and the positive third group is composed of a convex lens.

By making each unit compatible with the desired refractive power arrangement and aberration correction, the lens system can be made compact while maintaining good performance. The negative first lens unit has a role of focusing the off-axis chief ray on the center of the stop, and has a large amount of refraction of the off-axis chief ray on the wide-angle side, so that various off-axis aberrations, particularly astigmatism, Distortion tends to occur. Therefore, like a normal wide-angle lens, a concave-convex configuration in which an increase in the lens diameter on the most object side is suppressed, and the negative lens mainly sharing the negative refractive power is refracted by using two lenses of four and five. They are trying to share power.

Each lens constituting the first group has a shape close to a concentric spherical surface centered on the stop center in order to suppress the generation of off-axis aberrations caused by the refraction of off-axis chief rays.
The positive second group has a so-called triplet configuration.
This is because, since the group is largely moved, spherical aberration and coma aberration are removed to some extent in the group alone in order to prevent manufacturing deterioration due to eccentricity between the groups due to manufacturing errors. The most object-side convex lens 1 in the 2 groups
Reference numeral 0 denotes a convex shape on the object side so that off-axis chief rays emitted from the first group are largely refracted and various off-axis aberrations do not occur. Further, the concave lens 11 has a concave surface on the image side, and a negative air lens is formed together with the convex surface of the convex lens 12 on the image side to correct the spherical aberration generated with a large aperture ratio. The third positive lens unit also has a role as a field lens for making the image side telecentric.

In this embodiment, an aspherical surface is effectively introduced in order to achieve a further improvement in optical performance while configuring each group with a small number. In the embodiment shown in FIG. 1, the concave surface of the concave lens 4 constituting the first lens unit has an aspheric surface whose positive refracting power becomes strong around the object side, and the correction of astigmatism and distortion on the wide-angle side is particularly effective. Is going. The object side surface of the convex lens that constitutes the third group has an aspheric surface whose positive refractive power becomes weak at the periphery, and contributes to correction of various off-axis aberrations throughout the zoom range. Usually, barrel distortion at the wide-angle end poses a problem for distortion. In the present embodiment, correction is performed not only at the wide-angle end but also over the entire zoom range together with the aspherical surface introduced into the first lens unit.

When photographing an object at a short distance using the zoom lens of the present embodiment, good performance can be obtained by moving the third lens group toward the object.

Hereinafter, numerical values of the present embodiment will be shown.

In the numerical examples, i indicates the order of the surface from the object side, Ri is the radius of curvature of the lens surface, and Di is the i-th lens surface.
Lens thickness and air gap between the i-th surface and the
, Νi denote the refractive index and Abbe number for the d-line, respectively. The two surfaces closest to the image are glass materials such as a face plate. B, C, D, E, and F are aspherical coefficients. The aspherical shape is represented by x = R ｛1−where the displacement in the optical axis direction at the position of height h from the optical axis is x with respect to the surface vertex.
(1-h2 / R2) 1/2｝ + Bh4 + Ch6 + Dh8 +
It is represented by Eh10 + Fh12. Here, R is a radius of curvature.

[Numerical Example 1] This numerical embodiment is a zoom lens having a zoom ratio of 2.5 and an aperture ratio of about 2.8 to 4.0. FIG. 19 is a cross-sectional view, FIGS.
Shows a numerical example.

(Embodiment) FIG. 1 is an exploded perspective view of a lens barrel showing an embodiment of a camera embodying the present invention, FIGS. 2 to 4 are central sectional views, and FIG. 3 shows a wide position, and FIG. 4 shows a tele position.

Reference numeral 1 denotes a base which is a base of the lens barrel unit.
The lens barrel unit structure is formed together with the fixed barrel 2 fixed to the front end by screws. 3 is a first lens barrel,
The lenses 4, 5, and 6 shown in FIG. 19 are held. Three follower pins 7 each having a tapered portion at the end are press-fitted on the outer peripheral side surface, and a cap 8 is fixed to the front surface by bonding.

Reference numeral 9 denotes a two-group lens barrel, and lenses 10, 11, and 12
And is integrally held by the drawing base plate 14 of the drawing unit 13 by means such as bonding.

FIG. 5 is an exploded perspective view of the aperture unit 13.
On the outer peripheral portion of the drawing base plate 14, two follower portions 14a having a tapered portion at the tip are integrally formed, and one movable follower 81 movably provided in the axial direction is provided. Are evenly arranged. The rear end of the movable follower 81 is pressed and urged by a leaf spring 82, whereby the mechanical gap is shifted to maintain the accuracy. Here, the movable follower 81 is provided at a position which is the highest when the camera is in the normal position among the three followers, whereby the direction of the one-sided movement and the direction of gravity are substantially the same, and the movable follower 81 has a small urging force. A sufficient biasing effect can be obtained. The effect of space saving can be obtained and the driving load can be reduced.

Numeral 83 denotes a coil wound around a bobbin.
A magnetic torque is generated in the magnet 87 formed integrally with the arm 86 via the arm 5.

Numerals 88 and 89 are light quantity adjusting members, and linearly elongated holes 88b to 89d and 89b to 89d provided respectively are slidably provided by being guided by shafts 14b to 14e of the base plate 14. Further, two shaft portions 86a and 86b provided on the arm portion of the arm 86 are inserted into holes 88a and 89a of the light amount adjusting members 88 and 89.

Reference numeral 90 denotes a cap which holds and fixes the coil 83 and the yokes 84 and 85 between the base plate 14 and the arm 86 (and the magnet 87) so as to be rotatable. Reference numeral 91 denotes a case for preventing the light amount adjusting members 88 and 89 from falling off.

The aperture unit 13 is arranged on the inner periphery of a rectilinear guide cylinder 49 described later. For this purpose, the coil 83 and the magnet 86 which require a certain space in the unit are separately disposed on both sides of the optical axis, and the longitudinal direction thereof is made to coincide with the sliding direction of the light amount adjusting members 88 and 89. Therefore, the arrangement is suitable for the inside of a cylindrical part such as the straight guide cylinder, which contributes to downsizing of the apparatus.

Reference numeral 15 denotes a third lens barrel holding a lens 16,
While being guided by guide bars 17 and 18 extending in the optical axis direction, the position in the axial direction is regulated by a nut 19 having a female screw held between its arms, and is biased by a tension spring 20 in the retracting direction. . As shown in FIG. 7, a third group barrel 1 is provided in a slit portion 19a provided in the nut 19.
The projection 15a of the fifth is fitted, and the rotation is restricted.

Numeral 21 is a screw provided integrally with the magnet 22 and has a male screw portion screwed with the female screw portion of the nut 19. Reference numeral 23 denotes a bearing metal pressed into the base 1 and one end of the screw 21 is rotatably fitted.

Numeral 24 denotes a step motor for driving the third lens barrel 15, and as shown in FIG.
Two sets of coils 27 wound around bobbins 5 and 26 are arranged so as to face each other linearly so as to sandwich the magnet 22, and are fixed on the base 1 by screwing a yoke plate 28. .

Reference numeral 29 denotes a photointerrupter fixed to the base 1, and a slit plate 30 integrally fixed to the third lens barrel 15 is disposed at a position where the slit plate 30 can advance and retreat to the slit portion of the photointerrupter.

Reference numeral 31 denotes a cap fixed to the base 1.
Fix the distal ends of the guide bars 17 and 18
1 is rotatably held.

Reference numeral 32 denotes an image sensor, which is fixed and held to a holding plate 33 fixed to the base 1 with screws by bonding or the like. Reference numeral 34 denotes a flexible circuit for supplying the photoelectrically converted image signal to a signal processing circuit described later. Numeral 35 denotes dustproof rubber, and numeral 36 denotes a low-pass filter (LPF), both of which are fixed to the base 1 by adhesion or the like. With the image sensor 32 fixed to the base 1, the image sensor 1, the rubber 35, and the low-pass filter 36 are held by a holder 1 ′ of the base 1 provided therearound, and along one side of the holder 1 ′. A magnetic circuit of a motor 24 composed of a coil 25, a yoke, and a magnet is arranged.

A drive ring 37 is rotatably fitted to the outer periphery of the fixed cylinder 2. As shown in FIG.
Has a gear portion 37a in a part thereof. 38 is DC
In the motor, a pinion gear 39 is integrally provided on the output shaft by press fitting or the like. The driving force of the motor 38 is, in order from the gear 39, the gears 40, 41, 42, 43, 44, 4
5 to the gear portion 37a of the drive ring 37.
These gears 40 to 45 are housed in gear boxes 46 and 47 and fixed to the base 1. The motor 38 is also fixed to the gear box 46.

A movable cam ring 48 is fitted on the inner peripheral portion of the fixed cylinder 2, and a linear guide cylinder 49 is fitted on the inner peripheral portion thereof. A drive pin 50 and a follower pin 51 having a tapered portion are set up on the outer periphery of the movable cam ring 48 in three equal parts, and the drive pin 50 penetrates through the hole 2a of the fixed cylinder 2 to drive the drive ring 37.
Is fitted in a groove 37b provided on the inner peripheral side of the groove.

As shown in FIG. 9, the follower pin 51 has a tapered end portion in sliding contact with a tapered cam groove 2b provided on the inner periphery of the fixed cylinder 2. FIG. 9 is an inner development view for explaining the above.

In the development of the inner surface of the movable cam ring 48 shown in FIG. 10, tapered cam grooves 48a,
8b, respectively, said followers 7 and 14a
(Or 81) are in sliding contact. At the same time, the side surfaces of the respective followers are aligned with the straight grooves 49a, 49b of the straight guide cylinder 49.
, And its position in the rotation direction is regulated.

The front projection 49c on the outer periphery of the straight guide cylinder 49 is in contact with the groove 48c on the inner periphery of the moving cam ring, and the rear flange portion 49d is in contact with the end of the moving cam ring. This restricts the relative movement of the rectilinear guide cylinder relative to the movable cam ring in the optical axis direction. At the same time, the rear projection 49e is fitted in the straight groove 2c on the inner periphery of the fixed cylinder 2 so as to be able to move straight, and the movement in the rotation direction is restricted.

As shown in FIGS. 1 to 6, the step motor 24 is developed at substantially the same height as the image pickup device 32 and the LPF 36, and is linearly developed along one side thereof. A screw 21 and a magnet 22 are arranged in the vicinity of the center. As a result,
The group lens barrel 15 can be made thin and flat, and cylindrical parts such as the moving cam ring 48 and the linear guide cylinder 49 can be arranged close to each other, so that the apparatus can be downsized.

The guide bars 17 and 18 and the screw 21 are moved around the aperture unit and the moving cam ring 48 by aligning the longitudinal direction of the aperture unit 13 with the longitudinal direction of the step motor 24. It can be arranged in an empty space inside, thereby shortening the overall length of the device when collapsed as shown in FIG.

In FIGS. 1 to 4, reference numeral 52 denotes a cap which holds a dust-proof sheet 53 between itself and the fixed cylinder 2 and has rail portions 52a and 52b on its front surface for guiding a barrier 54 to be described later. Also, the groove 48 of the moving cam ring
A dust-proof sheet 55 is also inserted in c.

In FIGS. 11 and 12, a linear sensor 56 is fixed to the base 1 by screws or the like. The circuit configuration is composed of a variable resistor as shown in FIG. 11A, and when the slider 56a is slid, the output becomes as shown in FIG.
It changes linearly as shown in FIG. Reference numeral 57 denotes a lever for holding the slider 56a between the arms 57a, and is guided by a guide bar 58.

The lever 57 has a follower portion 57b having a tapered portion at the tip, and its side face is fitted in the groove 1a of the base 1. Reference numeral 59 denotes a spring for biasing the lever. FIG. 12 is a front view of this part.

FIG. 13 is a development view of the outer surface of the driving ring 37.
The follower portion 57b of the lever is in sliding contact with the linear cam groove 37c. 37d and 38e are tapered cam grooves for driving a finder lens (not shown) for zooming.
60 is a follower unit provided integrally with a compensator lens (not shown), and 61 is a variator lens (not shown).
Are provided integrally with the cam grooves 37d and 37e.

In FIGS. 1 and 14, the barrier 54 is supported rotatably about a shaft 63 erected on the barrier base 62, and is closed from the front of the apparatus by a closing spring 64 hooked on a hook 54a of the barrier 54. Seemingly biased clockwise.

Reference numeral 65 denotes a barrier drive lever, which is rotatably supported about a shaft 66 erected on the barrier base 62. An opening spring 67 is hooked on the hook portion 65a and is urged clockwise. . Here, the spring force of the two springs is set as "close spring 64 << open spring 67".

A shaft 68 is erected at one end of the barrier drive lever 65 at a position corresponding to one side surface of the barrier 54. 69 is a leaf switch provided by integral molding,
It is fixed to the barrier base 62 by screws. The barrier base 62 is fixed to the base 1 with screws.

FIG. 14A shows a state in which the barrier is closed, and the step 37 f of the drive ring 37 is moved to the barrier drive lever 65.
The barrier drive lever 65 is locked in a state where the barrier drive lever 65 is rotated counterclockwise against the urging force of the opening spring 67 by abutting against the bent portion 65b. The barrier 54 rotates in the closing direction by the urging force of the closing spring 64, and the bent portion 54 b abuts on the stopper 2 d of the fixed cylinder 2 to be in a closed state.

FIG. 15 is a block diagram showing the electrical connection of a camera embodying the present invention. The lens barrel 71 has been described above, and the components included in the drawing are denoted by the same reference numerals.

The image signal photoelectrically converted by the image pickup device 32 is subjected to predetermined processing such as color conversion and gamma processing by a signal processing circuit 72 and then recorded in a memory 73 such as a card type recording medium. The control unit 74 controls the entire camera.
Linear sensor 56 inside the lens barrel, photo interrupter 2
9. The step motor 24, the DC motor 38, and the aperture unit 13 are controlled while monitoring the outputs of the leaf SW 69 and the like, and the signal processing and the memory are also controlled.

Reference numeral 75 denotes an electrically erasable / recordable nonvolatile memory, for example, an EEPROM or the like. Reference numeral 76 denotes a mode dial switch, which can switch and set various function modes such as a power-off mode, a shooting mode, a playback mode, and a PC connection mode.

The operation of the above configuration will be described below.

When the DC motor 38 is driven, the drive ring 37 is rotated via the gears 39 to 45 (FIG. 8) as described above, and the movable cam ring 48 is rotated via the drive pin 50. It also moves in the optical axis direction to move along the cam 2b of the fixed cylinder 2 via 51 (FIG. 9). When the movable cam ring 48 moves in the direction of the optical axis, the linear guide cylinder 49
Also moves in the direction of the optical axis, but moves only in the direction of the optical axis without rotating because the protrusion 49e on the outer periphery is restricted by the fixed cylindrical groove 2c.

When the movable cam ring 48 rotates, the first lens barrel 3
The second lens barrel fixed to the aperture unit 13 relatively moves in the optical axis direction along the grooves 49a and 49b of the rectilinear guide cylinder according to the lifts of the cams 48a and 48b of the movable cam ring 48 (FIG. 10).

FIGS. 16A and 16B show only the trajectory of the cam portion. FIG. 16A shows the cam of the fixed cylinder 2, and FIG.
(C) is a second group cam of the movable cam ring 48. (D) is the movement trajectory of the first lens barrel, which is the sum of (a) and (b), and (e) is the movement trajectory of the second lens barrel, which is the sum of (a) and (c).

W on the horizontal axis is the wide position, T is the tele position, S
Is a retracted position, and each cam is provided with a flat area from the retracted position S to a position indicated by B. In this way, by driving the DC motor 38, switching between the retracted position and the photographable position and the zoom operation in the photographing range are performed.

When the drive ring 37 rotates, the finder lens (not shown) moves in the optical axis direction along the cams 37d and 37e via the followers 60 and 61 as described above, and interlocks with the zoom operation of the lens barrel. I do.

At the same time, the lever 57 moves in the optical axis direction along the cam 37c to displace the slider 56a of the linear sensor 56 and change its output as shown in FIG. By detecting this output, the zoom position can be sequentially detected.

As shown in FIG. 16 (d), the first lens barrel draws a locus of reciprocating movement convex to the image side between wide and tele. Therefore, by making the three cams non-linear between Wide and Tele, the inclination of each cam can be suppressed low, and the driving load can be reduced. In addition, by providing both the fixed cylinder cam (a) and the first cam group (b) of the movable cam ring so as to have a maximum value between the retracted position and the wide position,
The amount of extension of the first lens barrel 3 can be dispersed to the two cams (a and b), the total length of the fixed cylinder 2 and the movable cam ring 48 can be shortened, and the size of the apparatus can be reduced. I have.

As described above, when the drive ring 37 rotates, the stepped portion 37f of the drive ring 37 locks the barrier drive lever 65b (FIG. 14 (a)). The lock is released and the barrier drive lever 6 is released.
5 rotates clockwise by the urging force of the opening spring 67 and presses the side surface of the barrier 54 via the shaft 68. As described above, since the urging force of the closing spring 64 is weaker than the urging force of the opening spring 67, the barrier 54 is rotated in a counterclockwise direction, and FIG.
The open state shown in FIG. At this time, the bent portion 54b of the barrier 54 presses the section 69a of the leaf switch 69, and the switch is turned on. The opening and closing operations of the barrier 54 are set to be completed in the flat areas of the respective cams shown in SB in FIG.

When the step motor 14 is driven, the screw 21 rotates via the magnet 22. Nut 1
Reference numeral 9 moves in the optical axis direction because it is restricted by the projection 15a of the third lens barrel 15 as described above, and the third lens barrel also moves in the optical axis direction following this, thereby performing focus adjustment. Within the range of the operation stroke of the third lens barrel, the slit plate 30 enters or retracts into the slit portion of the photointerrupter 29 and switches its output, at which time the counter is reset.

FIG. 17 is a flowchart showing the operation of the camera. FIG. When the photographing mode is selected by the mode dial 76 (s101), the control unit determines in s102 whether the zoom position of the lens barrel unit is the retracted position or the wide to tele photographable position based on the output of the linear sensor. Determine.

When the position is wide to tele, s10
Go to 7. If it is in the retracted position, the DC motor 38 is driven by a predetermined amount in the feeding direction in s103. The predetermined amount is an amount corresponding to S to B in FIG. 16 described above. Here, the zoom drive is temporarily stopped, and it is detected whether or not the leaf switch 69 is on (s104).

In s104, when the switch is off, it is considered that an error has occurred, and a process such as displaying a warning is performed (s105). When the switch is on, zoom drive is further performed and the lens barrel is extended to the wide position. (S106).

After the zoom drive is completed, the next step motor 29 is moved in the direction of the switching position of the photo interrupter 29.
Is driven (s107). When the switching can be detected, it stops at that position and resets the count (s108).
However, if it cannot be detected for some reason, a warning is displayed indicating that an error has occurred, and at the same time, zoom driving is prohibited (s109). When the reset operation is completed, the apparatus is further driven to the standby position where the focus operation is started, and enters a standby state in which shooting is possible (s110).

FIG. 17B shows the state at the end of the photographing mode.
When a mode other than the photographing mode such as the power-off or the reproduction mode is selected by the mode dial 76 (s111), the step motor 29 is first driven to move the third lens barrel to the collapsing standby position (s112). This position is adjusted in advance in the manufacturing process for each camera individually, and is stored in the nonvolatile memory 75. Next, the DC motor 38 is driven to move the lens barrel to the retracted position (s113), and the photographing mode ends (s11).
4).

The state at this time is as shown in FIG. 2 as described above. As apparent from FIGS. 2 to 4, the drive stroke of the third lens barrel 15 at the photographable position overlaps the retracted position of the second lens barrel 12.

Therefore, as described above, control is performed so that zoom driving is performed first at the start of photographing, and control is performed such that the third lens barrel is always moved to the retractable standby position first when retracted.
Collisions between the lens barrels can be avoided, and the distance between the lens barrels during collapsing can be made extremely small. At the same time, if a malfunction occurs in the reset operation of the third lens barrel, the damage to the device can be avoided by inhibiting the zoom operation.

Although the switching positions of the photointerrupters usually vary widely, by storing the retractable standby position in the memory as described above, it is possible to store the photointerrupters at extremely small intervals while avoiding collision with the base 1. I can do it.

[0079]

According to the first invention of the present application, in particular, a retractable zoom lens barrel in which a lens group is driven by combining cylindrical members is provided inside the cylindrical member. Even if it is arranged and configured to move in the optical axis direction, it can be arranged without increasing the size of the device.

In the second invention of the present application, the size of the device can be reduced.

In the third invention of the present application, the longitudinal direction of the magnetic circuit of the light amount adjusting device is made to coincide with the longitudinal direction of the driving means, so that the overall length at the time of collapsing is shortened and the device can be downsized.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a lens barrel of a camera embodying the present invention.

FIG. 2 is a central sectional view of the lens barrel of FIG. 1 (retracted position).

FIG. 3 is a central sectional view of the lens barrel of FIG. 1 (wide position).

FIG. 4 is a central sectional view of the lens barrel shown in FIG. 1 (telephoto position).

FIG. 5 is an exploded perspective view of the aperture unit of FIG. 1;

FIG. 6 is an exploded perspective view of the step motor unit shown in FIG. 1;

FIG. 7 is a front view of a third-group barrel driving unit in FIG. 1;

FIG. 8 is a view showing a zoom drive gear train shown in FIG. 1;

FIG. 9 is an inner developed view of the fixed cylinder of FIG. 1;

FIG. 10 is an inner developed view of the moving cam ring of FIG. 1;

FIG. 11 is a characteristic diagram of the linear sensor of FIG. 1;

FIG. 12 is a front view around the linear sensor of FIG. 11;

FIG. 13 is an external development of the drive ring of FIG. 1;

FIG. 14 is an explanatory view of the barrier opening / closing mechanism of FIG. 1;

FIG. 15 is a block diagram showing an electric configuration of a camera equipped with the lens barrel of FIG. 1;

FIGS. 16A to 16E are views for explaining cams of the lens barrel of FIG. 1 and the trajectory of the barrel.

17 is a flowchart showing a driving sequence of the lens barrel in FIG.

FIG. 18 is a diagram showing a conventional light amount adjusting device.

FIG. 19 is a sectional view showing an optical arrangement.

FIG. 20 is an aberration diagram.

FIG. 21 is an aberration diagram.

FIG. 22 is an aberration diagram.

FIG. 23 is a diagram showing a numerical example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Base 2 ... Fixed barrel 3 ... 1st group barrel 9 ... 2nd group barrel 13 ... Aperture unit 15 ... 3rd group barrel 24 ... Step motor unit 32 ... Image sensor 37 ... Drive ring 38 ... DC motor 48 ... Moving cam Ring 49: straight guide cylinder 54: barrier 56: linear sensor.

Claims (8)

[Claims] 1. A magnetic circuit comprising: a plurality of light amount adjusting members slidably guided in a direction orthogonal to an optical axis; a coil, a yoke, and a magnet; and the magnetic circuit provided on the magnet and integrally rotated. An arm that drives a light amount adjusting member; and an image pickup device including a light amount adjusting device having: a coil and a magnet constituting the magnetic circuit are arranged to face each other with an optical axis interposed therebetween; An imaging device extending along a direction substantially orthogonal to the imaging device. 2. A lens barrel movably provided in an optical axis direction, a guide member for guiding the lens barrel in a straight line, a feed screw having a screw portion for moving the lens barrel, and the feed screw. A driving unit that rotationally drives the imaging device, an imaging element that converts the imaged image information into an electric signal, and a holding member that holds the imaging device, wherein the driving unit is integrated with the feed screw. A magnet provided, and a magnetic circuit including a plurality of coils and a yoke arranged linearly opposed to each other with the magnet interposed therebetween, wherein the magnetic circuit is arranged along one side of the holding member. An imaging device characterized by the above-mentioned. 3. A light amount adjusting member which is slidably guided in a direction perpendicular to an optical axis, a magnetic circuit having a coil, a yoke, and a magnet, and said light amount adjusting member provided on said magnet and integrally rotated. An arm for driving a member, wherein a coil and a magnet constituting the magnetic circuit are arranged to face each other with the optical axis interposed therebetween, and the magnetic circuit extends along a direction substantially orthogonal to the optical axis. A plurality of devices arranged linearly opposite to each other with a magnet integrally provided on a feed screw having a screw portion for moving a lens barrel movable in the optical axis direction guided straight by a guide member. The magnet, the coil, and the yoke are configured along a side of a holding member that holds an image sensor that converts image information formed into an image into an electric signal. A driving means for rotationally driving the feed screw, which is location,
An imaging device comprising: 4. The imaging apparatus according to claim 1, wherein an opposing direction of the coil and the magnet of the magnetic circuit coincides with a sliding direction of the light amount adjusting member. 5. The apparatus according to claim 2, wherein the driving unit does not interfere with the lens barrel in an optical axis direction when the lens barrel is closest to the image sensor. Imaging device. 6. The imaging apparatus according to claim 3, wherein the longitudinal direction of the magnetic circuit of the light amount adjusting device and the longitudinal direction of the driving unit are matched. 7. The imaging device according to claim 1, wherein the light amount adjusting device is disposed in a lens barrel. 8. The imaging apparatus according to claim 1, wherein the lens barrel is configured to extend forward from a retracted position in the apparatus main body.