JPH0199011A - Zoom devices such as cameras - Google Patents

Abstract

PURPOSE:To prevent a motor from being left in an electric conduction state by positioning a variable power lens at the telephoto end or the wide end and stopping the motor, when a variable power operation is continued after the variable power lens has reached the telephone end or the wide end. CONSTITUTION:When a telephoto switch 106 turns on and a variable power lens has reached the telephoto end, a controller 100 turns off a transistor 105, and dissipates drawing-down force to an arm of a dividing lever. Accordingly, the lever is turned counterclockwise by force of a spring, and when a notch of a dividing board has moved to a position of the claw, the claw goes into the notch, a switch 36 turns off, and the controller 100 turns off a transistor 91 and stops a motor 60. Thereafter, even if a variable power operation button is pushed continuously, an electromagnetic plunger 87 is annihilated, and also, the motor is stopped, therefore, the variable power lens is positioned at the telephone end and it becomes ineffective to continue the variable power operation.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a zoom device used with optical equipment such as a camera or an observation device, and more specifically, the invention relates to a zoom device that is used with optical equipment such as a camera or an observation device. The present invention relates to an automatic zoom device of the type that varies with two variables.

[Background of the Invention] Various types of zoom lenses are known for use in cameras and the like. The conventional zoom lens that is commonly used is the so-called fixed rear lens type, and this type of zoom lens has a focusing lens, a focusing lens,
It has a structure in which four groups of lenses are arranged: a variable power lens, a correction lens, and a relay lens. This rear lens fixed type zoom lens is easy to determine the position of the focusing lens because the position of the focusing lens is not a function of the position of the variable power lens. It has the advantage of being able to link the lens with the gold-foil lens and allowing stepless zooming, but on the other hand, the front element is very large and heavy, making it difficult to operate due to its large size, and the distance to the subject is limited. Another drawback is that high-speed operation is extremely difficult because the amount of oscillation of the focusing lens is large with respect to fluctuations in .

In contrast to the above-mentioned fixed rear lens zoom lens, a fixed front lens zoom lens is known. Although the latter does not have the disadvantages of fixed rear lens zoom lenses, it has the characteristic that the amount of focusing lens movement changes depending on two variables: the position of the variable magnification lens and the subject distance, so this type of mechanical mechanism (front lens fixed type) is extremely difficult to realize, so even though it is known theoretically, it has not been put into practical use. Also,
In the case of a fixed front lens type, a calculation device such as a microcomputer is required to determine the amount of movement of the focusing lens, but it is possible to calculate the amount of movement of the focusing lens corresponding to any variable magnification lens position and any subject distance. Since this would require a large-capacity, high-speed arithmetic unit, it was difficult to realize from an electronic device perspective.

Therefore, the present inventors have endeavored to develop a practical fixed front lens zoom device in consideration of the current situation, and have recently succeeded in developing a practical fixed front lens zoom device. A novel fixed front lens zoom device developed by the present inventor is
While the variable power lens is moving, the variable power lens is configured to stop only at a plurality of predetermined positions between a position corresponding to the longest focus (tele end) and a position corresponding to the shortest focus (wide end), and The present invention is characterized in that it is configured such that only the amount of movement of the focusing lens in is calculated. This configuration not only prevents the variable magnification lens movement mechanism from becoming complicated, but also eliminates the need for a large-capacity, high-speed arithmetic unit. A type zoom device is realized.

However, the novel zoom device developed by the present inventor still has the following problems that need to be solved.

In a zoom device configured as described above, a fixed position stopping mechanism consisting of an indexing mechanism is used as a variable power drive mechanism to stop the variable power lens only at a plurality of predetermined positions between the wide end and the telephoto end. On the other hand, a well-known cam ring with a cam groove is used as a variable magnification lens movement mechanism, but the known cam ring is a part that is prone to manufacturing errors, so At the wide end, there is a high possibility that the operating time of the fixed position stop mechanism (that is, the stop time of the variable power drive mechanism) and the time when the cam ring reaches the end position of the rotatable range may not match. Therefore, in the above-mentioned zoom device, it is necessary to provide a margin (design margin) for the variable magnification lens sliding mechanism to account for the manufacturing error.

Specifically, in the new zoom device developed by the present inventor, the rotation limit position of the cam ring is set outside the tele end corresponding position and the wide end corresponding position,
Therefore, even when the variable power lens reaches the wide end or telephoto end, when the fixed position stop mechanism does not operate (that is, the variable power drive mechanism does not stop), the cam ring can rotate further.

Therefore, in the zoom device developed by the present inventor, manufacturing errors of the cam ring etc. can be absorbed at the telephoto end and the wide end, but there are differences in the time when the cam ring reaches its rotation limit position and the time at the telephoto end and the wide end. Since there is a time difference between when the fixed position stop mechanism is activated (that is, when the variable power drive mechanism is stopped), there is a problem in that the following phenomenon occurs.

That is, in the zoom device, if the camera user continues to press the variable power operation button even after the variable power lens reaches the telephoto end or wide end during the variable power operation, the fixed position stop mechanism will not operate ( (the power supply to the variable power drive mechanism continues), the variable power lens will no longer be set to the wide end or telephoto end, and the motor that drives the variable power drive mechanism will be left energized. There was a risk of wasting power.

[Object of the Invention] An object of the present invention is to provide a zoom device that is smaller and lighter than a rear lens fixed type zoom device, and to calculate the amount of focusing lens movement more easily and faster than a conventional front lens fixed type zoom device. The purpose of the present invention is to provide a novel zoom device that can perform An object of the present invention is to provide a novel zoom device with a fixed front lens having a structure that prevents a phenomenon in which a motor for moving the lens is left in an energized state.

[Summary of the Invention] In the zoom device according to the present invention, the variable magnification lens is driven so as to stop only at a plurality of predetermined positions between the telephoto end and the wide end, and at the telephoto end and the wide end. The device is characterized in that the focusing lens is positioned at a focusing position determined by two variables: the stopping position of the magnifying lens and the distance to the object, etc., and is particularly characterized by the feature of the device of the present invention. The reason for this is that, in addition to having the above-mentioned configuration, if the zoom lens continues to be operated by the camera user even after it reaches the telephoto end or the wide end, the zoom lens will continue to operate regardless of the continuation of the zoom operation. The lens is forcibly positioned at the telephoto end or wide end, and the motor is stopped.

[Embodiments of the invention] The present invention will be described in detail below with reference to the drawings.

FIG. 1 is an exploded perspective view of the mechanical structure of an embodiment of the zoom device according to the present invention.

In the figure, 1 is a cam ring equipped with a gear 2 at its rear end and has cam grooves 3 and 4 formed on its outer circumferential surface;
5 is the 1st group lens (front lens), 6 is the front plate to which the 1st group lens 5 is fixed, 7 is the 2nd group lens for focusing (middle lens), and 8 is the holder to which the 2nd group lens 7 is fixed. , 15 is a rotary ring equipped with a face cam 56 for controlling the position of the holder 8 in the optical axis direction, and 16 rotatably supports the rotary ring 15 and includes a known aperture unit (not shown) such as aperture blades 54. ), the 2nd group base plate carrying 11 is 3
A group lens (rear lens) 12 is a third group base plate to which a third group lens 11 is fixed. 2nd group lens 7 (focusing lens)
2 group base plate 1 supporting a holder 8 carrying a holder 8 and a rotating ring 15 for controlling the positioning of the holder 8
6 and the third group lens 11 for variable magnification are housed in the cam ring 1, and two upper and lower wooden guide bars 9 extend parallel to the optical axis within the cam ring 1. and 10, and the guide bars 9 and 1
It is possible to slide along 0.

23 is a rear base plate, and three support rods 24 to 26 extending parallel to the optical axis are protruded from the front surface of the rear base plate 23.

The support rods 24 to 26 are arranged on the same circumference centered on the optical axis (the center of the rear base plate 23), and the outer circumferential surface of each of the support rods 24 to 26 is a part of the circumferential surface with the same radius of curvature. The cam ring 1 is rotatably fitted on the outer circumferential surface of each of the support rods 24 to 26. The total length of each support rod 24 to 26 is 1
When the cam ring 1 is fitted to each of the support rods 24 to 26,
It has a length that protrudes slightly forward from the front end. Screw holes 24a to 2 drilled in the front end surface of each support rod 24 to 26
6a is a screw insertion hole (blind hole) 6a drilled in the front plate 6
~6C, and are screwed into the screw holes 24a~2fia through the screw insertion holes 6a~6C and screws 59a, 59b, and 59c allow the front base plate 6 to connect to the support rods 24~2.
It is designed to be fastened to the front end surface of 6. That is,
The front plate 6 and the first lens group 5 are fixed to the rear plate 23, and the zoom device of this embodiment has a fixed front lens structure.

The front base plate 6 and the rear base plate 23 have three pairs of holes (4 pairs) aligned with each other.
8,51), (49,52) and (50,53) are drilled. Of these, both ends of the upper guide bar 9 passing through the cam ring 1 are fitted and fixed into the holes 48 and 51, and both ends of the lower guide bar 10, which also passes through the cam ring 1, are fitted and fixed into the holes 49 and 52. Ori,
Also, in the hole 50 and the hole 53, an end portion 1 of a drive shaft 17 for autofocus, which will be described later, also passes through the inside of the cam ring 1.
7a and 17b are rotatably inserted and supported.

The holder 8 carrying the second group lens 7 is suspended at its upper end so as to be slidable relative to the upper guide bar 9, and has a U-shaped member at its lower end that engages with the lower guide bar 10. A notch 8a is formed. Further, a protrusion 55 as a follower that engages with the face cam 56 of the rotary ring 15 is provided on the rear end surface of the holder 8, and a spring 75 that always pulls the holder 8 backward keeps the protrusion 55 on the face. It is pressed against the cam 56.

Rotating ring 1 equipped with face cam 5B on the front side
5 is supported by the 2 group base plate 16 so as to be able to rotate only.
A gear portion 73 that constantly meshes with a gear 18, which will be described later, is formed on the outer peripheral surface of the rotary ring protruding forward from the base plate 16, and a ratchet tooth portion 74 is provided parallel to the gear portion 73. This ratchet tooth portion 74 is a member that engages with a stop lever 19, which will be described later.
Together with 9, it constitutes a device for controlling the rotation stop position of the rotary ring 15 (ie, focusing movement amount control means for the second lens group 7).

A protrusion 57 is formed on the same circumferential surface of the rotary ring as the row of ratchet teeth 74 and at a position slightly apart in the circumferential direction from the row of ratchet ridges 74, and this protrusion 57 is connected to the stop lever as will be explained later. The claw 19a at the tip of the projection 5
This is to bring the armature 21 at the rear end of the stop lever 19 closer to the yoke 20 of the electromagnet 90 when the stop lever 19 rides on the stop lever 7.

The rotating ring 15 is supported by the second group base plate 16 so as to be able to rotate by the same circumferential length as the circumferential length of the face cam 56.
The cluster base plate 16 is provided with a stopper (not shown) that determines the maximum rotation angle range of the rotary ring 15.

A conductor pattern 86 for detecting the rotation angle of the rotary ring 15 (that is, for detecting the amount of movement in the optical axis direction or the amount of protrusion of the second group lens 7) is formed on the front surface of the rotary ring 15. Two contacting pieces 85 are attached to a stationary part (not shown).

The second group base plate 16 carrying the rotating ring 15 is suspended and supported by the upper guide bar 9 so as to be relatively slidable, and has a U for engaging with the lower guide bar 10 so as to be relatively slidable.
A shaped notch 16a is provided on the lower circumferential surface. Further, a pin 13 is protruded from the outer circumferential surface of the second group base plate 16 and is slidably engaged with the cam groove 3 on the outer circumferential surface of the cam ring 1.

Like the second group main plate 16, the third group main plate 12 carrying the third group lens 11 is suspended and supported by the upper guide bar 9 so as to be slidable relative to the lower guide bar 10. A U-shaped notch 12a for engagement is provided on the lower peripheral surface, and a pin 14 is provided on the outer peripheral surface to be slidably inserted into the cam groove 4 of the cam ring 1.

The stop lever 19 for controlling the stop position of the rotary ring 15 is an L-shaped lever configured to be rotatable around an axis 19b parallel to the optical axis, and the stop lever 19 is always rotated counterclockwise by a spring 22. energized in the direction. The stop lever 19 is a rotating ring! One arm has a claw 19a that engages with the ratchet teeth 74 of No. 5, and a second armature that is attracted to the yoke 20 of the electromagnet 90 is attached to the other arm. The electromagnetic magnet 90 is a control member for lifting the pawl 19a of the stop lever 19 from the ratchet teeth 74 of the rotary ring 15, and has a yoke 20 and a coil 69 wound around it, and includes electrical components described below. It has become one of the

The electromagnet 90 and the stop lever 19 are supported on a movable support member connected to the second group base plate 16, and when the movable support member moves along the optical axis together with the second group base plate 16, the electromagnet 90 and the stop lever 19 are supported. Stop lever 19
It also moves and hangs together with the second group base plate 16.

Most of the drive shaft 17 for autofocus is configured as a non-cylindrical part with a non-circular cross-sectional shape with a so-called two-sided outer peripheral surface, and a rotating ring 1 is provided in the non-cylindrical part.
A gear 18 that always meshes with the gear portion 73 of No. 5 is fitted so as to be movable only in the axial direction. Further, a gear 27 for transmitting power to the drive shaft 17 is fixed to the rear end 17b of the drive shaft 17.

A conductor pattern plate 78 is attached to the outer peripheral surface of the cam ring 1 to detect the position of the cam ring 1 after rotation has stopped (that is, the focal length after a zooming operation or the change in focal length due to zooming). pattern board 78
Three sliding contact pieces 77a that come into sliding contact with the upper conductor pattern
~77c are attached to a stationary structure (not shown).

Here, the sliding contact pieces 77a to 77c constitute a detection means for detecting the respective axial movement amounts of the second group base plate 16 and the third group base plate 12 when the cam ring 1 is rotated for zooming. These detection means are included in the electrical configuration described later.

A drive mechanism for rotationally driving the gear 27 and the gear 2 of the cam ring 1 is arranged on the outside of the cam ring 1.
The drive mechanism is composed of the following mechanical elements.

60 is a reversible motor for supplying power to gear 2 and gear 27; 32 is a pinion fixed to the shaft of motor 60; 31 is a ring-shaped gear that meshes with pinion 32;
70 is a first sun gear that is rotatably supported relative to the gear 31 within the center hole 63 of the gear 31, and 71 is a second sun gear that meshes with a gear 65 that is a component of the first sun gear 70 and that will be described later. a planetary gear 72 that meshes with one of the constituent gears 72 and can revolve around the center hole 63 of the gear 31;
is arranged on the same axis as the first sun gear 71 and meshes with the gear 67 which is a component of the planetary gear 71.
It's the sun gear. The gear 31, the first sun gear 70, the second sun gear 72, and the planet gear 71 constitute a speed reduction mechanism and transmission switching mechanism.

The first sun gear 70 constitutes a part of the power transmission system to the gear 27, and includes a journal portion 64 that is fitted into the center hole 63 of the gear 31 so as to be relatively rotatable, and a journal portion 64 that is fitted in the center hole 63 of the gear 31 to the front side. It has a gear 65 that protrudes from the outside and meshes with the large gear 58 of the planetary gear 71, and a gear 34 that meshes with the gear 28 that is part of the power transmission system for the gear 27.

The second sun gear 72 constitutes a part of the power transmission system for the gear 2 and the cam ring 1, and includes a gear 33 that meshes with the small gear 67 of the planetary gear 71 and a gear 66 that meshes with the first intermediate gear 30. are doing.

The planetary gear 71 has the two gears 58 and 67 described above, and a shaft 62 common to both gears is fixed on the surface of the gear 31.

As shown in the figure, the power transmission system for the gear 2 includes a second sun gear 72, a first intermediate gear 30 that meshes with the gear 72, a second intermediate gear 61 that meshes with the gear 30, and a second sun gear 61 that meshes with the gear 61 and meshes with the gear 2. A third intermediate gear 29 is provided, and a second intermediate gear 61 is capable of stopping the cam ring 1 at every predetermined rotation angle position (in this embodiment, every rotation of the second intermediate gear 61). A fixed position stop mechanism is coupled.

The fixed position stopping mechanism includes an index disk 68 (namely, an index disk) fixed to the second intermediate gear 61, and a claw 41 that fits into a notch 47 on the outer periphery of the index disk 68.
L-shaped index lever 4 with a at the tip of one arm
1, and the other arm 41b of the lever 41 is configured such that the lever 41 is rotated counterclockwise around its pivot shaft 41c (that is, the claw 41a is always placed in the notch 47 of the indexing plate 68). A spring 42 is locked, which biases it in the direction of entry.

The fixed position stopping mechanism is a mechanism provided to stop the third group lens 11 (variable magnification lens) only at a plurality of predetermined positions during its entire stroke (that is, the length between the telephoto end and the wide end). With this mechanism, the cam ring 1 is stopped only at a predetermined rotational angle position, and the third group lens 1
1 is stopped only at a predetermined position during its entire stroke.

Stop position of 3rd group lens 11 (stop position of 3rd group base plate 12)
The more there are, the closer it gets to stepless zooming, but the stop position is
Even if there are only a few points, there is no significant difference in operational feel compared to stepless zooming. The number of teeth of gear 2 of cam ring 1 and the number of teeth of gear 29 and gear 61 are determined by the number of stop positions of third group lens 11. For example, if four stop positions are provided between the telephoto end and the wide end, the zoom device will be able to set six focal lengths. indexing board 68
The number of teeth of gear 2 and gears 29 and 61 may be determined so that the number of rotations is five.

The tip of the arm 41b of the indexing lever 41 is pressed against one contact piece 36a of the switch 36 by the force of the spring 42, and in the illustrated state where the claw 41a is inserted into the notch 47 of the indexing disc 68, the contact piece 36a is pressed against the contact piece 36a of the switch 36. Piece 36a is the other contact piece 38
When the claw 41a comes out from the notch 47, the contact piece 36a and the contact piece 36b come into contact with each other.

The switch 36 is a switch that controls the energization of the motor 60, as will be explained later, and is turned on when the contact piece 36a and the contact piece 38b are in contact, and turned off when both the contact pieces are separated.
, is the switch. In the state shown in FIG. 1, both contact pieces are separated from each other.

A bottle la is provided protruding from the outer peripheral surface of the front end of the cam ring 1,
A spring 8 attached to a structural member (not shown) is attached to the bottle 1a.
One end of the cam ring 9 is locked, and the cam ring 1 is urged counterclockwise in the figure by the spring 89. This spring 89 is for eliminating backlash in the meshing of the gear 2, the gear 29, and the gear 61 in the illustrated state in which the claw 41a of the indexing lever 41 is inserted into the notch 47 of the indexing plate 68, and the cam ring 1 After the rotation of the cam ring 1 has stopped, the backlash serves to prevent the cam ring 1 from slightly rotating clockwise.

In the configuration shown in FIG. 1, the cam ring 1 and its drive system constitute a variable power lens moving means for moving the third lens group, that is, the variable power lens 11, to an arbitrary variable power position, and the conductive pattern plate 78 and The sliding contact piece 77 constitutes a variable power lens position detection means. On the other hand, the indexing board 68
The index lever 41 constitutes a variable power lens fixed position stopping means for stopping the variable power lens only at a plurality of set positions between the long focal length end (tele end) and the short focal length end (wide end). It constitutes a locking and unlocking means for locking and unlocking the variable magnification lens moving means. Further, the lever 41 has a function as a switch operating means for operating the switch 36, and also has a function as the locking and unlocking means,
Therefore, the lever 41 and the spring 42 constitute sequential operating means for sequentially operating the switch 36 and locking and unlocking the variable magnification lens moving means with a predetermined time difference.

On the other hand, the drive system of the gear 27, the gear 18, the rotary ring 15, and various elements (in other words, a stop lever 19 and τ magnetic magnet 90, face cam 56, conductor pattern 86 and sliding contact piece 85
and the like) constitute a focusing lens moving means.

Further, a variable magnification lens position detection means consisting of a conductive pattern plate 78 and a sliding contact piece 77, a conductive pattern 86 and a sliding contact piece 8
5, a focusing lens position detection means consisting of a switch 36,
An electromagnetic magnet 90, a motor 60, a focusing position calculation means described later, and various signal generation switches described later are electrical components of the zoom device of this embodiment.

FIG. 2 is a diagram schematically showing the electrical configuration of the zoom device of this embodiment and the electrical configuration of a camera equipped with the zoom device of this embodiment.

In FIG. 2, reference numeral 60 refers to the aforementioned motor; reference numerals 91 to 94 refer to transistors constituting a motor drive circuit for controlling current supply and current direction to the motor 60;
9 is a coil of the electromagnetic magnet 90; 95 is a transistor for turning on/off the current supply to the coil 69; R1-R5 are resistors; 96 is a tele selection switch that is turned on when setting the long focus (tele) side optical system; 97 is the wide selection switch that is turned on when the optical system is set to the short focus (wide) side, 98 is the first release switch that is turned on when the camera's release button is pressed down on a half stroke, and 99 is when the release button is pressed on a full stroke. A second release switch is turned on when pressed down, 101 is an initial position detection switch that is closed when the second lens group is in the initial position, and 102 is composed of a conductor pattern 86 of the rotating ring 15 and a contact piece 85 that comes into sliding contact with the conductor pattern 86. This is a focusing lens position detection means.

100 is a control device such as a microcomputer having a calculation unit for calculating a focus position with respect to a variable magnification lens position; 103 is a known distance measuring circuit housed in the camera body;
104 is also a known automatic exposure control circuit (AE circuit)
, is.

Further, 106 is a telephoto end detection switch that detects that the cam ring 1 has reached the telephoto end position, and 107 is a wide end detection switch that detects that the cam ring 1 has reached the wide end position.

In the above configuration, the distance measuring circuit 103, the AE circuit 104, and the switches 98 to 99 are all provided in the camera body (not shown), and the control device 100 is also provided in the camera body. Among these, the switches 96 to 99 and the switch 101, the focus position calculation section in the control device, the control section for controlling the motor 6o, and the control section for controlling the electromagnetic magnet 90 are used in this embodiment. It is an electrical component of the example zoom device.

FIG. 3 is a flowchart of basic control operations in the control device 100. In the same figure, position E, WIDE,
The block labeled RELEASE represents a subroutine for control operations in the case of position H, a subroutine for control operations in the case of WIDE, and a subroutine for control operations in the case of release. These subroutines are shown in FIGS. 4 to 6. It is shown.

Next, the operation of each part of the camera equipped with the zoom device of this embodiment will be explained with reference to FIGS. 1 to 6.

When taking a picture, the camera user must first select whether to take a telephoto shot or a wide-angle shot.

When a power switch (not shown) is turned on and the control device 100 becomes operable, the control device 100 enters a state in which it performs the control operation shown in the flowchart of FIG. 3.

In this state, the user presses, for example, a tele selection button (not shown) to turn on the tele selection switch 96 that is linked to the button.
Then, the control device 100 enters a preparatory state for starting the control operation according to the tele subroutine shown in FIG. 5, line 8.

Next, when the camera user pushes one arm 41b of the indexing lever 41 in FIG. 1 in the direction of arrow A, the switch 36
The contact piece 36a of the switch 3 rises together with the arm 41b in FIG. 1 and comes into contact with the other contact piece 36b.
6 is turned ON. Switch 36 is turned on in control device 100
When the signal is input, the control device 100 generates an output signal that reduces the voltage applied to the base of the transistor 91,
As a result, transistor 91 is turned on and current flows from the emitter to the collector of transistor 91. When a current flows into the collector of the transistor 91, a base current flows into the base of the transistor 92 connected to the collector, so that the transistor 92 is also turned on, and the current flows from the collector of the transistor 92 through the armature of the motor 60. Power supply VBAT is applied to the collector of transistor 92.
A current will flow from there, and the motor 60 will start.

When the wide selection switch 97 is ON/L, the control device 100 generates an output signal to turn on the transistor 93, and when the tele selection switch 96 is turned ON, the control device 100 generates an output signal to turn on the transistor 91. That is, the tele selection switch 96 and the wide selection switch 97 have the functions of selecting the rotation direction of the motor 60 and selecting the control sequence within the control device 100.

As mentioned above, when the photographer presses the telephoto selection button and transistors 91 and 92 are turned on, the motor 60 rotates in the direction that rotates the pinion 32 clockwise in FIG. 1 (this direction is defined as forward rotation). However, at this time, the claw 41a of the indexing lever 41 is still in the notch 47 of the indexing board 68 (i.e., the length of the two arms of the lever 41 and the length of the two switches 36 are not the same). The installation position of the contact piece, the depth of the notch 47 of the indexing board 68, the claw 41
(The length of a, etc. is set so that the timing at which the pawl 41a escapes from the notch key 47 is later than the timing at which the switch 36 is turned on), the gear 61 is in a restrained state, and therefore, the gear 61 is in a restrained state. The two sun gears 72 are held in a locked state.

As described above, when the pinion 32 starts to rotate clockwise in FIG.
1 and its shaft 62 are given a torque that causes them to revolve around the central axis of the gear 31 in a counterclockwise direction. At this time, the large gear 33 in the second sun gear 72 that meshes with the small gear 67 in the planetary gear 71 is indirectly locked in a non-rotatable state as described above, so the second sun gear 72 is Since it does not rotate, the planetary gear 71 rotates counterclockwise around the large gear 33 of the second sun gear 72, so that the gear 71 rotates counterclockwise and revolves in the same direction.

On the other hand, since the small gear 65 in the first sun gear 70 that meshes with the large gear 58 in the planetary gear 71 is not locked, when the gear 58 revolves around the gear 65 while rotating counterclockwise, The gear 65 is rotated clockwise.

Therefore, since the first sun gear 70 is rotated clockwise, the large gear 34 therein is rotated clockwise, the intermediate gear 28 meshing with the gear 34 is rotated counterclockwise, and the gear 27 on the drive shaft 17 is rotated counterclockwise. are rotated clockwise, respectively. As a result, the shaft 17 is also rotated clockwise, and the gear 18 is rotated clockwise, so that the rotating ring 15 having the gear portion 73 that meshes with the gear 18 receives a torque rotating in the counterclockwise direction. Given. Therefore, the rotating ring 15 starts rotating counterclockwise from the position shown in FIG. The rotating ring 15 collides with the stopper and is prevented from rotating, at which point the rotating ring 15 is stopped. When the pawl 19a of the stop lever 19 rides on the protrusion 57, the stop lever 19 is rotated clockwise about its pivot point, so that the armature 21 attached to the lever 19 moves against the coil 69 of the electromagnetic magnet 90. However, since the coil 69 is not energized at this time, the armature 21 is not attracted to the yoke 20.

When the rotation of the rotating ring 15 is blocked by the stopper (not shown), the first sun gear 70 is locked, and the gear 65 stops rotating.

On the other hand, since the claw 41a of the indexing lever 41 escapes from the notch 47 of the indexing plate 68 almost at the same time as the rotating ring 15 stops rotating, the gear 61 and the second sun gear 72 are unlocked. 2 sun gear 72 becomes rotatable.

Note that the suppression operation of the arm 41b of the indexing lever 41 in the direction of arrow A will be continued until the variable power lens reaches the variable power position desired by the camera user. The connection (maintenance) may be performed by mechanical locking means or electromagnetic locking means instead of using the fingers of the camera user.

When the first sun gear 70 is locked and the second sun gear 72 is unlocked as described above, the planetary gear 71 to which the counterclockwise revolving torque is applied is now transferred to the first sun gear 70. In order to start shifting counterclockwise around the small gear 65 inside, the gear 58 meshing with the gear 65 rotates counterclockwise around the shaft 62 and rotates around the central axis of the gear 31. It will revolve counterclockwise. As a result, the second sun gear 72 having the gear 33 meshing with the gear 58 begins to rotate clockwise. Therefore, the gear 30 meshing with the gear 66 moves counterclockwise, the gear 61 moves clockwise, and the gear 29 moves counterclockwise.
Then, the cam ring 1 starts rotating clockwise together with the gear 2. Therefore, the second group main plate 16 and the third group main plate 12, which have the pins 13 and 14 engaged with the cam grooves 3 and 4 of the cam ring 1, are connected to the guide bars 9 and 1o.
While being guided by the cam grooves 3 and 4, the cam grooves 3 and 4 are moved parallel to the optical axis and toward the front by an axial movement amount corresponding to the inclination angle of the respective cam grooves 3 and 4. In this case, when the second group main plate 16 moves parallel to the optical axis according to the inclination angle of the cam groove 3, the rotating ring 15 supported on the second group main plate 16 also moves together with the main plate 16,
Since the second group lens holder 8 having a protrusion 55 pressed against the face cam 56 of the rotating ring 15 by a spring 75 is also moved along the optical axis direction together with the base plate 16, the second group lens 7 also follows the slope of the cam groove 3. It will be moved forward depending on the corner. At this time, the gear part 7 of the rotating ring 15
Since the gear 18 meshing with the gear 3 also slides along the axial direction on the drive shaft 17, the meshing state between the gear portion 73 and the gear 18 is always maintained. Also, the stop lever 19
The movable support member (not shown) supporting the electromagnetic magnet 9o and the movable support member (not shown) supporting the electromagnet 9o are connected to the second group base plate 16 as described above. The base plate 16 also moves together with the base plate 16.

Since the inclination angles of the cam grooves 3 and 4 are different, the rotation of the cam ring 1 causes both the second group lens 7 and the third group lens 11 to move forward in the right direction in FIG. The interval will become smaller. That is,
This means that the focal length of the optical system including both lenses becomes longer.

In the zoom device of the present invention, after the cam ring 1 starts rotating, the rotation of the cam ring 1 is stopped (that is, the lens 7
(and stopping the movement of the index lever 41 in the optical axis direction) is possible by inserting the index lever 41 into the notch key 47 of the index plate 68.
This is only when the claw 41a enters. That is, the claw 41
Even if the force in the direction A is removed from the arm 41b of the indexing bar 41 when the index bar 41 is in sliding contact with the outer peripheral surface of the indexing board 68, the gear 61 will not be locked, and the switch 3
Since the two contact pieces 36a and 3ftb of the cam ring 6 are kept in contact with each other, the motor 60 does not stop, and therefore the rotation of the cam ring 1 continues.

After the camera user removes the force in the direction of arrow A on the arm 41b of the indexing lever 41, when the claw 41a of the lever comes to the position of the notch 47 of the indexing plate 68, the claw 41a moves into the notch 47 by the force of the spring 42. The index board 68 and gear 61 are locked. Subsequently, the arm 41b of the lever 41 pushes down the contact piece 36a of the switch 36 to break contact between the contact piece 36a and the other contact piece 36b, so the switch 36 is turned OFF, and in response, the control device 100 stops the motor 60 by turning off transistors 91 and 92.

By stopping the rotation of the cam ring 1, the movement of the second group lens 7 and the third group lens 11 in the optical axis direction is stopped, and the optical system including both lenses is set to a longer focal length than the initial state.

After the supply of driving force to the cam ring 1 is cut off, a counterclockwise torque is applied to the cam ring 1 by the spring 89, so that backlash in the meshing of the gear 2, the gear 29, and the gear 61 is suppressed. will not wobble from the stopped position.

In the above zooming process, the rotation angle of the cam ring 1, that is, the amount of movement of the second group lens 7 and the amount of movement of the third group lens 11 (
That is, the rotation angle position when the cam ring 1 stops rotating is the position of the second group lens 7 when it stops, and the position of the third group lens 1 when it stops.
(corresponding to position 1) is electrically detected by the relative sliding between the conductive pattern plate 78 on the cam ring 1 and the sliding contact piece 77.

Note that if the zooming operation is performed as described above and the camera user continues to press the zooming operation button even after the zooming lens reaches the telephoto end (that is, the arm 41 of the lever 41
b (kept raised in the direction of arrow A in Figure 1), the cam ring 1 attempts to rotate further beyond the tele end corresponding position, but just before the cam ring 1 exceeds the tele end corresponding position. The telephoto end detection switch 106 shown in FIG. 2 is turned on, and the control device 100 turns off the transistor 91 in response to the signal generated by turning on the switch 106. Therefore, the motor 60 is stopped and the rotation of the cam ring 1 is also stopped, so that the variable power lens is positioned at the telephoto end.

When the zooming operation is completed and the completion is displayed on a display device (not shown), the camera can be released.

Therefore, if the camera user presses the camera's release button and depresses the button first by a half stroke, then the second
The switch 98 shown in the figure is turned on, and the resulting bundled signal is manually input to the control device 100.
starts execution of a subroutine program related to release as shown in FIG. That is, the control device 100
In response to the ON of the switch 98, the distance measuring circuit 103 of FIG. 2 is operated as shown in FIG. 6 to perform distance measurement, and then
Capture and store distance measurement results. When distance measurement is completed, the completion of distance measurement is displayed on a display device (not shown). When the camera user presses the release button further to the full stroke in response to this display, the switch 99 in FIG. 2 is turned ON.
In response to this, the control device 100 first turns on the transistor 95 in FIG. 2, and then turns on the transistor 95.
Turn on 1 and 92.

When the transistor 95 is turned on, a current flows through the coil 69 of the electromagnetic magnet 90 and the coil 69 is excited, so that the armature 21 can be attracted to the yoke 2o.

Now, when the transistors 91 and 92 are turned on, the motor 60 starts rotating in the forward direction (clockwise in FIG. 1), the pinion 32 is rotated clockwise, and the gear 31 is rotated counterclockwise. At this time, since the indexing plate 68 is locked by the indexing lever 41 as shown in FIG. 1, the second sun gear 72 is also locked and cannot rotate.

Therefore, as described above, since the small gear 67 of the planetary gear 71 rolls counterclockwise around the large gear 33 of the sun gear 72, the gear 67 revolves in the direction of movement while rotating counterclockwise. Therefore, the small gear 65 of the first sun gear 7o that meshes with the large gear 58 of the planetary gear 71 is rotated clockwise, and the gear 27 and the drive shaft 17 are rotated clockwise. Therefore, the rotating ring 5 having the gear portion 73 meshing with the gear 18 rotating together with the shaft 17 starts rotating counterclockwise. As a result, the pawl 19a of the stop lever 19 rides on the protrusion 57 as described above, but since the coil 69 of the electromagnetic magnet 90 is energized, the pawl 19a of the stop lever 19 remains pulled up above the ratchet teeth 74. Retained. Furthermore, rotating ring 1
5 rotates counterclockwise and comes into contact with a stopper (not shown), the initial position detection switch 101 shown in FIG.
00 switches the current direction to the motor 60. As a result, the rotating ring 15 starts to rotate clockwise, so the face cam 56 also rotates in the same direction, and the second group lens holder 8
As the protrusion 55 of the face cam 56 gradually moves from the lowest position to the highest position, the holder 8 is pushed forward from the rotating ring 15. The rotation angle of the rotating ring 15 at this time is detected as an electrical pulse signal by the focusing lens position detection means 102 formed by the conductor pattern 86 and the sliding contact piece 85, and the pulse signal is counted by a counter in the control device 100. and compared with the distance measurement results. Since the rotating ring 15 is rotated clockwise by the gear 18 while the count value of the pulses generated from the detection means 102 is not equal to the distance measurement result,
During this time, the protrusion 55 of the second group lens holder 8 moves from the lower position to the higher position of the face cam 56 of the rotating ring 15, and as a result, the holder 8 is pushed forward. When the count value and the distance measurement result become equal, the control device 100 generates a signal to turn off the transistor 95, and as a result, the electromagnetic magnet 9o is demagnetized, so that the stop lever 19 The pawl 19a springs into the ratchet teeth 74 by the force of the spring 22 and stops the rotation of the rotary ring 15 in the clockwise direction. Further, since the control device 100 simultaneously generates a signal to turn off the transistor 91, the transistors 93 and 94 are turned off, and the motor 60 is stopped, and the gear 18 also stops rotating, so the rotating ring 15
Power supply to the equipment will also be stopped.

Next, a signal for operating the AE circuit 104 is generated from the control device 100, and the AE circuit 104 is operated in response to the signal, operating the aperture unit in the second group base plate 16 and the shutter mechanism (not shown) to control exposure and take pictures. will be held.

After photographing (exposure) is completed, when a signal indicating the end of exposure is transmitted from the AE circuit 104 to the control device 100, the control device 100 returns the focusing lens 7 (second group lens) to the initial position and focuses. In order to return the lens moving means to its initial state, a signal is generated to turn on the transistor 91.

When the transistor 91 is turned on in response to this signal, the transistor 92 is also turned on, and as a result, the motor 60 starts rotating clockwise in FIG. At this time, the index board 68 is locked by the index lever 41, so the second
Sun gear 72 is also locked, and therefore, as before, gear 27 will eventually be rotated clockwise in FIG. 1, and rotation ring 15 will begin to rotate counterclockwise. At this time, the pawl 19a of the stop lever 19 is engaged with the ratchet teeth 74;
The teeth are inclined in a direction that allows the rotation ring 15 to rotate counterclockwise even when the pawl 19a is engaged, so even when the pawl 19a is engaged, the counterclockwise rotation of the rotary ring 15 is inhibited. It never happens.

When the rotation ring 15 starts rotating counterclockwise, the projection 55 of the second group holder 8 descends from a high position to a low position on the face cam 56, so that the second group lens 7 gradually retreats rearward. Then, the protrusion 55 is connected to the face cam 5.
When the motor 6 reaches the lowest position, the initial position detection switch 101 is turned on as described above, and this signal causes the motor 60 to stop and the rotating ring 15 to stop as well.

Next, a case where the photographer presses the wide selection button will be explained. When the wide selection switch 97 is turned on, lines 8 enter a preparatory state for starting the control operation according to the wide subroutine shown in FIG. Then, when one arm 41b of the indexing lever 41 in FIG. 1 is pushed in the direction of arrow A, the switch 36 is turned on and the transistor 93
．． 94 is ONL/Holder 60 begins to rotate (reverse) in a direction that rotates pinion 32 counterclockwise. At this time, the sun gear 72 is still held in the locked state as described above. Therefore, the rotating ring 15 is the first
It is driven to rotate clockwise from the state shown in the figure, but the pawl 19a of the stop lever 19 falls into the first tooth of the ratchet teeth 74, so it cannot rotate any further clockwise. It becomes locked. Almost at the same time as this rotating ring 15 stops rotating, the indexing lever 41
Since the gear 61 and the sun gear 72 are unlocked in order for the claw 41a to escape from the notch 47, the second gear 61 and the sun gear 72 are unlocked.
The sun gear 72 becomes rotatable.

As a result, the cam ring 1 is eventually rotationally driven in the counterclockwise direction via the planetary gear 71 to which a clockwise revolving torque is applied. Therefore, the optical system is set to the short focus side. The release operation after the above magnification changing operation is the same as that described above, and will therefore be omitted.

FIG. 7 shows another embodiment of the zoom device of the present invention. This embodiment is characterized in that the sequential operation means includes an electromagnetic plunger 87. In the zoom device of this embodiment, the order operation means includes an indexing lever 41A having an inverted letter shape, and one arm 41 of the lever 41A.
and an electromagnetic plunger 87 having a rod 88 that is engaged with a pin 41e protruding from the edge d, and the electromagnetic plunger 87 is connected to the control device 10 as shown in FIG.
It operates according to a control signal from 0.

As shown in FIG. 7, the lever 41A has a long arm 41b that engages with the contact piece 36a of the switch 36, and an indexing plate 68.
It has an arm with a claw 41a that engages with the notch 47 of the bottle 41e, and a short arm 41d from which the bottle 41e is protruded. It is possible to swing. (The structure other than the sequential operation means is the same as the embodiment shown in FIG. 1, so the explanation will be omitted.) FIG. 2, in which parts indicated by the same reference numerals as in FIG. 2 represent the same configuration as in FIG. 2.

FIGS. 9 and 10 show the control device 1 when a zooming operation is performed in the zoom device having the configuration shown in FIGS. 7 and 8.
1 is a flowchart of a program executed in 00.

In FIG. 8, 105 is a transistor for driving the electromagnetic plunger 87, and the transistor 105 is turned on and off by applying a control signal from the control device 100 to the base of the transistor 105. The signal applied to the transistor 105 is generated when the camera user presses the variable power button, and disappears when the user stops pressing the variable power button.

The magnification changing operation in the apparatus of the embodiment shown in FIG. 7 will be explained with reference to FIGS. 7 to 9.

When the camera user presses a magnification change operation button (not shown) to change the magnification to the telephoto side, the telephoto selection switch 9B is turned on, and in response, the control device 100 selects the transistor 10.
A signal is generated to turn on transistor 105, which turns on transistor 105. Then, the rod 88 of the plunger 87 is pulled down, so that the lever 41A is inserted into the shaft hole 41c of the pivot portion.
It is rotated clockwise in FIG. 7 around . Since the arm 41b of the lever 41A is considerably longer than the other arms 41d, etc., the amount of movement of the tip of the arm 41b is considerably larger than the amount of movement of the claw 41a. The contact piece 36a of 36 contacts the contact piece 36b and the switch 36 is turned on. switch 36 is on
Then, as described above, the control device 100 turns on the transistors 91 and 92 to rotate the motor 60. When the motor 60 is rotated, as described above,
First, power is transmitted to the gear train that follows gear 27,
After the rotating ring 15 is rotated counterclockwise, the rotation of the rotating ring 15 is stopped by a stopper. Immediately after the rotating ring 15 stops rotating, the pawl 41a escapes from the notch 47 of the indexing plate 68, so the gear 61 is unlocked and the power of the motor 60 is transmitted to the gear train including the gear 61. Become. Therefore, the magnification changing operation is performed by rotating the cam ring 1 as described above. After starting the motor 60, the control device 100 monitors whether the telephoto selection switch 96 is turned off, and turns off the transistor 105 if the switch 96 is turned off before the variable magnification lens reaches the telephoto end. This demagnetizes the electromagnetic plunger 87, eliminates the pulling force on the arm 41d of the indexing lever 41A, and allows the claw 41a of the lever 41A to slide into the notch 47 of the indexing board 68. Furthermore, the switch 36 is activated by the lever 41. OF
After being set to F (see the flow on the right side of FIG. 9), the motor 60 is stopped by turning off the transistor 91.

On the other hand, if the telephoto selection switch 96 continues to be turned on during the zooming operation, the control device 100 monitors whether the telephoto end detection switch 106 is turned on and determines whether the switch 10B is turned on. (that is, when the variable magnification lens reaches the telephoto end), the transistor 105 is turned off.
F and demagnetizes the electromagnetic plunger 87, thereby eliminating the pulling force on the arm 41d of the indexing lever 41A as described above. Therefore, the lever 41A is rotated counterclockwise by the force of the spring 42, and when the notch 47 of the indexing plate 68 moves to the tip of the pawl 41a, the pawl 41a jumps into the notch 47. In this case, when the electromagnetic plunger 87 is demagnetized, the lever 41A
If the claw 41a of the lever 41A is in sliding contact with the outer circumferential surface of the indexing plate 68, the arm 41b of the lever 41A cannot return to its original position, so that the motor 6 will continue to operate even after the electromagnetic plunger 87 is demagnetized.
0 rotates, and the motor 60 does not stop until the notch 47 of the indexing board 68 moves to the position of the claw 41a.Then, when the claw 41a jumps into the notch 47 of the indexing board 68, the switch is activated. 36 is turned off, and the control device 10
0 stops the motor 60 by turning off the transistor 91 (see the flow at the bottom center of FIG. 9). At this time, the camera user is still pressing the variable magnification operation button, but the electromagnetic plunger 87 is demagnetized and the motor 60 is also stopped, regardless of the variable magnification operation by the camera user. It is forced (automatically) positioned at the edge and subsequent continuation of the scaling operation is disabled. Then, when the camera user stops changing the magnification operation, the tele selection switch 96 turns OFF.
Therefore, the control device 100 returns to the initial state in the flowchart of FIG. 3 or enters a release standby mode.

Note that the W of the zoom device having the configuration shown in FIGS. 7 and 8
The magnification change operation in the IDE direction is controlled according to the flowchart in FIG. 10, but the magnification change operation in the ψIDE direction is only changed in that the rotation direction of the motor 60 is reversed in the power direction magnification change operation. Since it is different from the E direction magnification change operation, a detailed explanation of the WIDE direction magnification change operation will be omitted.

The flow on the right side of Fig. 10 is the control operation when the camera user stops the zoom operation before the variable magnification lens reaches the wide end, and the flow on the lower half and left side of the center of Fig. This control operation is performed when the camera user continues to change the magnification even after the magnification lens reaches the wide end.

As explained in the above embodiments, the zoom device of the present invention disables the continuation of the subsequent zooming operation when the variable power lens reaches the telephoto end and the wide end, thereby moving the variable power lens to the telephoto end. Since it is configured to automatically position the camera at the wide end and cut off power to the motor, there is no risk of wasting power.

In the above embodiment, the telephoto end detection and the wide end detection are performed using a simple switch, but a method may also be adopted in which the rotation angle of the cam ring 1 is detected as a pulse signal using a known rotary encoder or the like. Alternatively, a method of directly detecting the linear movement of the variable magnification lens holder may be adopted.

Further, although an example is shown in which an L-shaped bar or a T-shaped bar is used as the sequential operation means, a sequential operation means using a combination of a link mechanism and a viscous damper may be used instead. operating members and indexing board 68
The indexing member may be a completely separate member.

Furthermore, the opening/link of the drive system for the cam ring 1, the lock release means, and the variable power lens fixed position stopping means may be configured as separate devices.

Such various changes and modifications are included within the technical idea of the present invention.

[Effects of the Invention] As explained above, the zoom device of the present invention has a variable power lens moving mechanism that allows the variable power lens to stop only at a plurality of predetermined positions between the telephoto end and the wide end. Since the focusing lens is moved to the focusing lens position with respect to only the stop position of the variable power lens, the present invention enables a fixed front lens type zoom, which was difficult to realize with the conventional concept. The device can be easily realized. In other words, since the zoom device of the present invention is configured to calculate the focusing lens position only for a specific variable magnification lens position, it does not require a large-capacity calculation device, and it does not require a large-capacity calculation device, unlike the one installed in conventional cameras. Since it can be controlled by a relatively small-capacity computing device, it can be manufactured at a lower cost than the conventionally proposed fixed front lens zoom device, and it is also more cost effective than the conventionally known fixed rear lens zoom device. It is small and lightweight, and can be manufactured at low cost.

In addition, in the zoom device of the present invention, when the camera user continues to change the magnification without noticing that the variable magnification lens has reached the wide end or telephoto end, the motor that drives the variable magnification lens is automatically activated. Since the magnification lens is automatically positioned at the telephoto end or the wide end, there is no risk of wasting power.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view of the mechanical structure of a zoom device according to an embodiment of the present invention, and FIG. 2 shows electrical components of the zoom device of FIG. 1 and other electrical components related thereto. FIG. 3 is a flowchart of a program executed in the control device, which is one of the electrical components shown in FIG. 2, and FIGS. 4 to 6 are flowcharts of FIG. 3. 7 is a diagram showing a modified embodiment of a part of the zoom device in FIG. 1, FIG. 8 is a diagram showing the electrical configuration of the device in FIG. 7, and FIG. and FIG. 10 are flowcharts of a magnification change operation program executed within the control device of the zoom device having the configuration of FIGS. 7 and 8. 1...Cam ring 3 and 4...Cam groove 5.
...1st group lens 6...1st group base plate 7...2nd group lens 8...Holder 9 and 10...Guide bar 11...3rd group lens 12...3rd group base plate
13 and 14...Pin 15...Rotating ring
16... 2nd group base plate 17... Focusing lens drive shaft 19... Stop lever 20... Yoke 23...
...Rear base plate 24-26...Support rod 54.
...Aperture blade 55...Protrusion 56...Face cam 57...Protrusion 60...Motor
68... Indexing plates 41 and 41A... Indexing lever 47... Notch 70... First sun gear 71... Planet gear 72... Second sun gear 73... (Rotating ring 15 ) Gear part 74... Ratchet tooth part 90... Electromagnetic magnet 77... Sliding contact piece 78... Conductor pattern plate 85...
Sliding contact piece 86...conductor patterns 91-94
...Transistor 96...Tele selection switch 97
... Wide selection switch 98 ... Second release switch 99 ... Second release switch 100 ... Control device 87 ... Electromagnetic plunger 101 ... Initial position detection switch 106 ... Telephoto end detection switch 107... Wide end detection switch 108... Focusing lens position detection means

Claims (1)

[Claims] (1) A variable power lens moving means for automatically moving a variable power lens according to a variable power operation by a user of a camera, etc., and a variable power drive locking device for locking and unlocking the variable power lens moving means. variable power lens fixed position stopping means having a function of stopping the variable power lens only at a plurality of predetermined positions between a position corresponding to the longest focus and a position corresponding to the shortest focus; limit position detection means for detecting that the corresponding position and the shortest focus corresponding position have been reached, and when an output is generated in the limit position detection means, the variable magnification lens is moved to the maximum focus corresponding position regardless of the continuation of the variable magnification operation. or a limit position forced stop means for forcibly stopping at one of the positions corresponding to the shortest focus.