JP3450762B2 - Optical device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical device such as a camera that can move an optical system between a use position and a storage position.

[0002]

2. Description of the Related Art Conventionally, in a camera in which a plurality of lens groups are moved in the direction of the optical axis to perform a zooming operation and a focus adjusting operation, the lens groups are housed in the camera body when not being photographed, and are retracted so that they can be carried. There is known one having a form suitable for. For such driving, an actuator such as a DC motor is used for the conventional zooming operation, and another actuator such as a step motor is provided for the focus adjusting operation, and the zooming operation is performed for driving to the retracted position. The actuator is further driven to be housed.

[0003]

However, in such a camera, the reference position of the moving lens group is detected by the position detector, and the lens group is driven by a predetermined amount from that position to the retracted position. In this case, in consideration of individual variations in the mounting position of the position detector, the drive amount must be set so that the lens group moves to the retracted position with a margin so that the lens group does not hit the retracted end. Therefore, when retracting the lens group,
There is a problem that a useless space is formed between the lens group and the collapsed end, and miniaturization cannot be sufficiently achieved when the lens is collapsed.

An object of the present invention is to provide an optical device capable of sufficiently reducing the size of an optical system when housed.

[0005]

In order to achieve the above object, the present invention provides a storage end that is movable between a use position and a storage position.
An optical system closest to the optical system, and drive means for driving the optical system,
A detecting means for detecting a reference position of the optical system, the optical
From the reference position where the system is detected by the detection means
The distance between the housing end without that abutting the housing end to the extremely small so as a storage position, rewritable for storing information about the count of the drive means which is obtained by actually measuring each device And a control means for controlling the driving of the driving means according to the information stored in the non-volatile memory.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

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, FIG. 2 is a retracted position, and FIG. 3 is a wide position. Reference numeral 4 indicates a tele position.

Reference numeral 1 is a base which is the base of the lens barrel unit,
The structure of the barrel unit is formed with the fixed barrel 2 fixed to the front end portion by screwing. 3 is a first-group lens barrel,
It holds the lenses 4, 5, and 6. Further, three follower pins 7 each having a tapered portion are press-fitted on the outer peripheral side surface, and a cap 8 is fixed to the front surface by adhesion.

Reference numeral 9 denotes a second-group lens barrel, which has lenses 10, 11, 12
Is held by the diaphragm base plate 14 of the diaphragm unit 13 by means such as adhesion.

FIG. 5 is an exploded perspective view of the diaphragm unit 13.
Two follower portions 14a having a tapered portion at the tip are integrally formed on the outer peripheral portion of the throttle base plate 14, and one movable follower 81 movable in the axial direction is provided, so that a total of three follower portions are provided. Are evenly distributed.

The movable follower 81 has its rear end pressed by a leaf spring 82 to bias the mechanical gap and maintain accuracy. Here, the movable follower 81 is provided at the highest position of the three followers when the camera is in the normal position, whereby the biasing direction and the gravity direction substantially coincide with each other, and a small biasing force is applied. A sufficient biasing effect can be obtained, a space saving effect can be obtained, and a driving load can be reduced.

Reference numeral 83 is a coil wound around a bobbin, and the magnetic flux generated by energizing the coil is yokes 84, 8
A magnetic rotational force is generated in the magnet 87 formed integrally with the arm 86 via the magnetic field.

Numerals 88 and 89 are diaphragm blades, and linear oblong holes 88b to d and 89b to d respectively provided in the diaphragm blades are base plates 1.
It is slidably provided by being guided by four shafts 14b to 14e. Further, the two shaft portions 86a and 86b provided on the arm portion of the arm 86 are provided with the hole portions 88a of the blades 88 and 89,
It is inserted in 89a.

Reference numeral 90 denotes a cap, which holds the coil 83 and the yokes 84, 85 between them and the base plate 14 to fix them, and rotatably holds the arm 86 (and the magnet 87). Reference numeral 91 is a case for preventing the blades 88 and 89 from falling off.

The diaphragm unit 13 is arranged on the inner circumference of a straight guide cylinder 49 which will be described later. Therefore, the coil 83, which requires a certain space in the unit, and the magnet 86 are separately arranged on both sides of the optical axis, and in particular, by making the longitudinal direction thereof coincide with the sliding direction of the blades 88, 89, The arrangement is suitable for the inside of a tubular part such as the straight guide tube, which contributes to downsizing of the device.

Reference numeral 15 denotes a third-group lens barrel holding a lens 16.
While being guided by the guide bars 17 and 18, its axial position is restricted by a nut 19 having a female screw held by its arm portion, and is tensioned by a tension spring 20 in the retracting direction. The projection 15a of the third group lens barrel 15 is fitted into the slit portion 19a provided on the nut 19, and the rotation thereof is restricted (FIG. 7).

Reference numeral 21 is a screw integrally provided with the magnet 22 and has a male screw portion which is screwed into the female screw portion of the nut 19. A bearing metal 23 is press-fitted into the base 1, and one end of the screw 21 is rotatably fitted therein.

Reference numeral 24 is a step motor for driving the third group lens barrel, and a pair of yokes 25, 26 and a coil 27 wound around a bobbin are linearly opposed to each other so as to sandwich the magnet 22. And is fixed by screwing the yoke plate 28 onto the base 1 (FIG. 6).

In FIG. 7, reference numeral 29 denotes a photo interrupter fixed to the base 1, and a slit plate 30 integrally fixed to the third group lens barrel 15 is arranged at a position where the slit plate of the photo interrupter can move forward and backward. ing. Reference numeral 31 is a cap fixed to the base 1 and includes guide bars 17 and 18
The front end side of is fixed and the screw 21 is rotatably held.

Reference numeral 32 is an image pickup element, which is fixed and held by adhesion or the like on a holding plate 33 which is fixed to the base 1 by screws. Reference numeral 34 denotes a flexible cable, which supplies the photoelectrically converted image signal to a signal processing circuit described later. Reference numeral 35 is a dustproof rubber, and 36 is a low pass filter (LPF), both of which are fixed to the base 1 by adhesion or the like.

A drive ring 37 is rotatably fitted on the outer peripheral portion of the fixed barrel 2. The drive ring 37 has a gear portion 37a on the outer peripheral portion thereof. Reference numeral 38 denotes a DC motor, and as shown in FIG. 8, 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 the gears 40, 41, 42, 43, 44, 4 in order from the gear 39.
5 is transmitted to the gear portion 37 a 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 provided on the inner peripheral portion of the fixed barrel 2.
Are fitted together, and the straight guide cylinder 49 is fitted on the inner periphery thereof.

The drive pin 5 is provided on the outer peripheral portion of the moving cam ring 48.
0 and a follower pin 51 having a tapered portion are erected in three equal parts, and the drive pin 50 penetrates the hole portion 2a of the fixed cylinder 2 and is fitted into the groove portion 37b provided on the inner peripheral side of the drive ring 37. I am fit. Further, the follower pin 51 has a tapered portion at its tip end slidably contacting a tapered cam groove 2 b provided on the inner circumference of the fixed barrel 2. FIG. 9 is an inner development view for explaining the above.

FIG. 10 is a development view of the inner surface of the moving cam ring 48.
Tapered cam grooves 48a and 48b are provided on the inner periphery thereof,
The follower 7 provided on the first-group barrel 3 and the follower 14a (or 8) provided on the diaphragm base plate 14, respectively.
1) is in sliding contact.

At the same time, the side surface of each follower is fitted in the linear grooves 49a and 49b of the linear guide cylinder 49, the position in the rotation direction is restricted, and the rotation of the first group lens barrel 3 and the diaphragm unit 13 is prevented. It regulates and allows straight movement.

The front projection 49c on the outer peripheral portion of the linear guide cylinder 49 is in contact with the groove 48c on the inner periphery of the moving cam ring 48, and the flange portion 49d at the rear end portion is at the end of the moving cam ring 48. The linear guide cylinder 49 is restricted from moving relative to the moving cam ring 48 in the optical axis direction. At the same time, the rear protrusion 49e
Is fitted in a straight groove portion 2c on the inner periphery of the fixed barrel 2 so as to be able to go straight, and its movement in the rotational direction is restricted.

As shown in FIGS. 1 to 6, in the present embodiment, the step motor 24 includes an LPF 3 in the image pickup device 32.
It is unfolded in a straight line along one side of the same height as the height of 6 stacked, and a screw 21 and a magnet 22 are arranged near the center of the one side. As a result, the third group lens barrel 15 can be thinly formed in a flat plate shape, and tubular parts such as the moving cam ring 48 and the linear guide tube 49 can be arranged close to each other, and the device can be downsized.

Further, by aligning the longitudinal direction of the diaphragm unit 13 with the longitudinal direction of the step motor 24, the guide bars 17, 18 and the screw 21 are provided around the diaphragm unit and on the movable cam ring 48. It can be placed in an empty space inside, which can shorten the total length of the device when retracted as shown in FIG.

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

A linear sensor 56 is fixed to the base 1 by screws or the like. The circuit configuration is a variable resistor as shown in FIG. 11A, and when a predetermined voltage is applied between the terminals 1 and 3, the slider 56a slides,
The output of the terminal 2 changes linearly as shown in FIG. Reference numeral 57 denotes a lever that holds the slider 56a on its arm portion 57a and is guided by the guide bar 58. Further, the lever 57 has a follower portion 57b having a tapered portion at its tip, and its side surface is fitted in the groove portion 1a of the base 1.
Reference numeral 59 is a spring that biases the lever. FIG. 12 is a front view of this portion.

FIG. 13 is a developed view of the outer surface of the drive ring 37.
The follower portion 57b of the lever is in sliding contact with the linear cam groove 37c. Further, 37d and 38e are taper cam grooves for zoom driving a finder lens (not shown),
Reference numeral 60 is a follower portion integrally provided with a compensator lens (not shown), and 61 is a variator lens (not shown).
Are integrally formed with the cam groove 37d and 37e, respectively.

In FIGS. 1 and 14, the barrier 54 is rotatably supported about a shaft 63 that is erected on a barrier base 62, and is seen from the front of the apparatus by a closing spring 64 hung on a hook portion 54a thereof. It is biased clockwise. Reference numeral 65 denotes a barrier drive lever, which is rotatably supported around a shaft 66 that is erected on the barrier base 62, and an opening spring 67 is hooked on the hook portion 65a and biased clockwise. Here, the urging forces of the two springs are set like "closing spring 64 << opening spring 67". Also,
A shaft 68 is planted at one end of the barrier drive lever 65 at a position corresponding to one side surface of the barrier 54. A leaf switch 69 is integrally formed, and is fixed to the barrier base 62 with screws. Barrier base 62 is base 1
It is fixed with screws.

FIG. 14 (a) is a view showing a state in which the barrier is closed. The step portion 37f of the drive ring 37 presses the barrier drive lever 65 against the bent portion 65b to open the spring 6.
It is locked in a state of being rotated counterclockwise against the biasing force of 7. The barrier 54 is rotated in the closing direction by the urging force of the closing spring 64, and the bent portion 54b of the barrier 54 is fixed.
It comes into contact with the stopper portion 2d and is in a closed state.

FIG. 15 is a block diagram showing electrical coupling of a camera embodying the present invention. The lens barrel 71 has been described above, and the components included in the drawing have the same numbers as above.

The image signal photoelectrically converted by the image pickup device 32 is subjected to predetermined processing such as color conversion and gamma processing by the signal processing circuit 72, and then recorded in the memory 73 such as a card medium.
The control unit 74 controls the entire camera, and monitors the outputs of the linear sensor 56, the photo interrupter 29, the leaf SW 69, etc. inside the lens barrel while the step motor 2 is being monitored.
4, the DC motor 38, the diaphragm unit 13 are controlled, and the signal processing and the memory are also controlled.

Reference numeral 75 denotes an electrically erasable / recordable non-volatile memory, for which an EEPROM or the like is used.

Reference numeral 76 is a mode dial switch, which can switch and set each function mode such as power-off, photographing mode, reproduction mode, PC connection mode and the like.

The operation of the above arrangement will be described below.

When the DC motor 38 is driven, the drive ring 37 rotates via the gears 39 to 45 as described above (FIG. 8). Since the drive pin 50 of the moving cam ring 48 penetrating the hole 2a of the fixed barrel 2 is fitted into the linear groove 37b formed along the optical axis in the inner peripheral portion of the drive ring 37, the drive ring 37 is driven. The rotation of the ring 37 causes the movable cam ring 48 to rotate via the drive pin 50. However, since the follower pin 51 of the movable cam ring 48 is fitted in the cam groove 2b of the fixed barrel 2, the movable cam ring 48 is fixed. It also moves in the optical axis direction along the second cam 2b (FIG. 9).

When the moving cam ring 48 moves in the optical axis direction,
The linear guide cylinder 49 also moves integrally in the optical axis direction, but does not rotate because it moves only in the optical axis direction because the protrusion 49e on the outer periphery is restricted by the fixed cylindrical groove portion 2c.

When the moving cam ring 48 rotates, the first-group barrel 3
And the second group lens barrel 9 fixed to the aperture unit 13 relatively moves in the optical axis direction in accordance with the lift of the cams 48a and 48b of the moving cam ring 48 along the grooves 49a and 49b of the linear guide cylinders, respectively ( (Fig. 10).

16A and 16B are views showing only the locus of the cam portion. FIG. 16A shows the cam of the fixed barrel 2, and FIG. 16B shows the moving cam ring 48.
The first group lens barrel cam is a second group cam of the movable cam ring 48. (D) is the movement locus of the first group lens barrel, which is the sum of (a) and (b), and (e) is the movement locus of the second group lens barrel, which is the sum of (a) and (c).

On the horizontal axis, W is wide position, T is tele position, and S is
Is the retracted position, and each cam is provided with a flat area from the retracted position S to the position indicated by B. In this way, by driving the DC motor 38, switching between the retracted position and the image capturing position (S to W) and zooming operation (WT to T) in the image capturing range (use position) 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 is interlocked with the zoom operation of the lens barrel. To do.

At the same time, the lever 57 moves along the cam 37c in the optical axis direction to displace the slider 56a of the linear sensor 56 and change its output as shown in FIG. 11 (b). The zoom position can be sequentially detected by detecting this output.

As shown in FIG. 16 (d), the first-group barrel 3 draws a locus that makes a convex reciprocating movement toward the image side between the wide position W and the tele position T. Therefore, by using a non-linear cam between the wide position W and the tele 1T for all of the above three cams, the gradient of each cam can be suppressed to a low level, and the driving load can be reduced. Further, by providing both the cam of the fixed barrel 2 shown in FIG. 16 (a) and the first group cam of the moving cam ring 48 shown in FIG. 16 (b) so as to have a maximum value between the collapsing and wide sides, It becomes possible to disperse the feed-out amount of the first-group barrel 3 to the two cams (a and b), shorten the total length of the fixed barrel 2 and the moving cam ring 48, and reduce the size of the apparatus. Has been realized.

Further, as described above, as shown in FIG. 14A, the step portion 37f of the drive ring 37 locks the barrier drive lever 65b when retracted, but when the drive ring 37 rotates, Accordingly, the locking is released, and the barrier drive lever 65 is rotated clockwise by the urging force of the opening spring 67 to press the side surface of the barrier 54 via the shaft 68.

As described above, since the biasing force of the closing spring 64 is weaker than the biasing force of the opening spring 67, the barrier 54 is rotated counterclockwise to the open state shown in FIG. 14 (b). At this time, the bent portion 54b of the barrier 54 is changed to the leaf switch 69.
Then, the switch 69 is turned on by pressing the section 69a. The opening / closing operation of the barrier 54 is set to be completed in the flat area of each cam shown in S to B of FIG.

When the step motor 24 is driven, the screw 21 rotates via the magnet 22. Nut 1
9 is moved in the optical axis direction because it is restricted by the projection 15a of the third group lens barrel 15 as described above, and the third group lens barrel 15 also moves in the optical axis direction following this to adjust the focus. Third-group lens barrel 15
Within the range of the operation stroke of, the slit plate 30 enters or retracts into the slit portion of the photo interrupter 29 and switches its output, and at this time, the counter of the step motor 24 is reset.

FIG. 17 is a flow chart showing the operation of the camera, and (a) shows the start-up time. When the shooting mode is selected by the mode dial 76 (s101), the control unit determines from the output of the linear sensor whether the zoom position of the lens barrel unit is the retracted position or the wide-to-tele shootable position. (S102).

When the position is wide to tele, s10
Proceed to 7. If it is in the retracted position, the DC motor 38 is driven in the feeding direction by a predetermined amount in s103. This predetermined amount is an amount corresponding to S to B in FIG. 16 described above, where the zoom drive is temporarily stopped and it is detected whether or not the leaf switch 69 is in the on state (s104). When the switch is off, it is considered that an error has occurred and processing such as displaying a warning is performed and further zoom drive is not performed and the step motor 29 is not driven thereafter (s105). If it is on, further zoom drive is performed. The lens barrel is driven to the wide position (s106).

When the extension of the lens barrel to the wide position by the zoom drive is completed, the step motor 24 is driven in the direction of the switching position of the photo interrupter 29 (s1).
07). When the switching of the photo interrupter 29 can be detected, the driving of the step motor 24 is stopped at that position and the count is reset (s108), but if it cannot be detected for some reason, an error is displayed and a warning is displayed. At the same time, further driving of the step motor 24 and zoom driving is prohibited (s109). When the reset operation is completed, the step motor 24 is further driven to a standby position where the focus operation is started, and a standby state in which photographing can be performed is set (s110).

FIG. 17B shows the end of the photographing mode.
When a mode other than the photographing mode such as power off or reproduction mode is selected by the mode dial 76 (s111), the step motor 24 is first driven to move the third group lens barrel 15 to the retracted position (compression completion position) (s112). . This position is adjusted in advance in the manufacturing process individually for each camera, and the step motor 24
Is stored in the non-volatile memory 75 as the count amount from the position where the counter is reset. Next, the DC motor 38 is driven to move the lens barrel to the retracted position (s11
3), the shooting mode is ended (s114).

The state at this time is as shown in FIG. 2 as described above. In the present embodiment, as shown in FIGS. 2 to 4, the driving stroke of the third group lens barrel 15 at the photographing possible position (usage state) is as follows when the second group lens barrel 9 shown in FIG. It overlaps with the retracted position, which does not become a movement area.

Then, as described above, at the start of shooting, 2
The group lens barrel 9 is extended, and then the third group lens barrel 15 is extended to the space vacated by the extension of the second group lens barrel 9, and when the lens barrel is retracted, the third group lens barrel 15 is first retracted to the retracted position. Since the second group lens barrel 9 is driven so as to be retracted into an empty space due to the third group lens barrel 15 being retracted, the distance between the lens barrels during collapse is extremely minimized while avoiding collision between these lens barrels. The size of the optical system can be reduced, and the size of the optical system when stored can be reduced.

At the same time, if a problem occurs in the reset operation of the third group lens barrel 15, the drive of the DC motor 38 and the drive of the step motor 24 can be prohibited to avoid damage to the equipment.

Further, although the switching positions of the photo interrupter usually have individual variations, by storing the retracted position in the memory as described above, the base 1 of the third group lens barrel 15 can be stored.
It can be stored at extremely small intervals while avoiding collision with.

(Correspondence between Invention and Embodiment) In the above embodiment, the third group lens barrel 15 is the optical system of the present invention, the step motor 24 is the driving means of the present invention, and the photo interrupter 29 is the present invention. The detection means stores a count amount from the reference position where the counter of the step motor 24 is reset by the photo interrupter 29 to the retracted position of the third group lens barrel 15 which is individually adjusted in the manufacturing process. Corresponds to the nonvolatile memory of the present invention, and the control unit 74 corresponds to the control means of the present invention.

The above is the correspondence relationship between each configuration of the present invention and each configuration of the embodiments, but the present invention is not limited to the configurations of these embodiments, and the functions shown in the claims or It goes without saying that any structure may be used as long as the functions of the structure of the embodiment can be achieved.

Further, the present invention may be made by combining the above-described embodiments and modified examples, or their technical elements as needed.

The present invention also relates to various types of cameras such as single-lens reflex cameras, lens shutter cameras, video cameras,
Furthermore, for optical devices and other devices other than cameras, further for those cameras, optical devices and other devices, and for devices applied to those cameras, optical devices and other devices, or for elements constituting these. Can also be applied.

Further, the present invention is such that the whole or part of the constitution of the claims or the embodiments forms one device and is combined with another device. It may be present or may be an element constituting the device.

[0063]

As described above, according to the present invention,
It is possible to provide an optical device that can sufficiently reduce the size of an optical system during storage.

[Brief description of drawings]

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

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

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

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

5 is an exploded perspective view of the aperture unit shown in FIG.

6 is an exploded perspective view of the step motor unit of FIG.

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

8 is a diagram showing a zoom drive gear train of FIG. 1. FIG.

9 is a development view of the inner surface of the fixed barrel of FIG. 1. FIG.

10 is a development view of the inner surface of the moving cam ring of FIG.

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

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

FIG. 13 is an outer developed view of the drive ring of FIG.

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

15 is a block diagram showing an electrical configuration of the camera of FIG.

16 is a diagram for explaining the loci of the cam and lens barrel of FIG.

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

[Explanation of symbols]

1 base 2 fixed cylinder 3 1st group lens barrel 9 Second group lens barrel 13 Aperture unit 15 Third group lens barrel 24 step motor unit 32 image sensor 37 drive ring 38 DC motor 48 moving cam rings 49 Straight guide tube 54 Barrier 56 linear sensor

Claims (3)

(57) [Claims] 1. A storage end movable to a use position and a storage position.
A nearest optical system, a driving means for driving the optical system, and detecting means for detecting a reference position of the optical system, the
From the reference position where the optical system is detected by said detecting means to the interval is extremely small becomes like storage position of said storage end without that abutting said storage end, obtained by actually measuring each device A rewritable non-volatile memory that stores information relating to the count amount of the driving means ,
An optical device comprising: a control unit that controls driving of the driving unit according to the information stored in the nonvolatile memory. 2. The optical device is a camera.
The optical device according to claim 1, which is a characteristic . 3. The optical device is a lens barrel
The optical device according to claim 1, wherein: