JPS60258527A - Finder magnification switching device - Google Patents

Abstract

PURPOSE:To switch finder optical systems effectively in a minimum space by moving forward or backward the second finder optical system in the optical axis direction of a finder according as the first finder optical system is inserted to or removed from the finder optical path. CONSTITUTION:The first object lens 56 constituting the first finder optical system and the second object lens 57 constituting the second finder optical system are stored in a finder storage part 1a and are provided on a camera body, and the object lens 57 of the second finder optical system is displaced to the position of the object lens 56 on the finder optical path according as the object lens 56 of the first finder optical system is moved to the evacuating position form the finder optical path by the switching operation of a photographic optical system. Thus, finder optical systems are switched effectively in a minimum space to make the camera small-sized.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD OF THE INVENTION The present invention relates to a finder magnification switching device for a camera having a photographing optical system capable of switching the focal length between a telephoto state, a wide-angle state, etc.

"Background of the Invention" In the above-mentioned cameras, it is necessary to switch the finder optical system in response to switching of the photographing optical system.

In such a case, there is a method of using a zoom finder optical system, but this has the disadvantage that the optical system becomes complicated and expensive.

Furthermore, Japanese Utility Model Application Publication No. 58-98523 discloses a system in which components of the finder optical system are replaced or inserted/removed in conjunction with changing the focal length of the photographic optical system, but the operating mechanism is large and takes up a lot of space. The disadvantage is that it requires a large amount of space and cannot be made compact.

In addition, simply inserting and removing the optical element laterally to switch the finder optical system requires a space for moving and storing the optical element to be inserted and removed, which protrudes laterally, so the camera itself has to be moved and removed laterally. thin 35m+a
This was difficult to adopt in format cameras and automatic focus adjustment cameras with many apertures on the front of the camera. ``Object of the Invention'' The purpose of the present invention is to effectively switch the finder optical system in a minimum space. It is an object of the present invention to provide a finder magnification switching device that solves the problems listed in item 42.

"Structure of the Invention" In order to achieve the above object, the present invention provides a viewfinder magnification switching device for a camera having a photographing optical system capable of changing the focal length; a first finder optical system that can be pushed and retracted between; a second finder optical system that can be displaced in the optical axis direction within the finder optical path; a first finder optical system driving means for pushing the system back; and: displacing the second finder optical system to the position occupied by the first finder optical system in response to a retracting operation of the first finder optical system from the insertion position to the retracted position. A finder magnification switching device comprising: a second finder optical system driving means; Alternatively, the optical function of the finder optical system can be effectively switched even in a narrow space by being displaced to the position occupied by the first finder optical system.

"Example" Hereinafter, one embodiment of the present invention will be described based on the drawings.

As shown in FIGS. 1 and 2, a focal length selection member 2 is provided on the rear surface of the camera body 1, and a switch SWI and a focal length selection member that are connected to a dustproof cover (not shown) are provided inside the camera body 1. A switch SW2 interlocked with the member 2 is provided.

A main optical system 3 is provided on the front side of the camera body 1 so as to be movable in the direction of its optical axis (in the left-right direction in the figure), that is, to be retractable and extendable. Inside the camera body l, a sub optical system 4 is provided in a direction (a direction transverse to the optical axis of the main optical system 3) between a position where it is inserted into the light beam of the main optical system 3, that is, a shooting light beam, and a position where it is withdrawn from the light beam. It is provided so that it can be displaced in the vertical direction (in Figure 1).

A plurality of finder optical systems including a first finder optical system 5 and a second finder optical system 6 are provided in the upper part of the camera body 1, housed in a finder housing 1a.

This finder optical system is disclosed in Japanese Patent Application No. 59-22588, and as shown in FIG. 14, is a reverse Galilean finder capable of changing magnification by a front group 5a and a rear group 5b.

The finder optical system as a whole is wide at the front and narrow at the rear, and a substantially trapezoidal space 7 is formed in the finder storage portion 1a adjacent to the narrowed portion of the finder optical system.

Also, on both sides of the finder optical system are AF (automatic focus adjustment) optical systems 8a and 8b.

The switch SWI is set to be OFF when the dustproof cover covers the main optical system 3, and to be ON when the front surface of the main optical system 3 is open. Further, the switch SW2 is set to be turned on when the focal length selection member 2 is at the telephoto position, and turned off when it is at the wide-angle position.

FIG. 3 is a side view showing the main optical system displacement mechanism and finder magnification switching device of this embodiment.

This figure shows the state when the main optical system 3 is in the extended position. There is an opening 1 in the center of the plywood lO through which the photographing light flux passes.
0a, and in front of it are fixedly installed an aperture/shutter device 11 and a main optical system 3 shown by dashed lines. A motor 12 is fixedly installed on the upper back surface of the plywood lO. Both ends of the rotating shaft penetrate through both end faces of the casing of the motor 12 and protrude, respectively.

A bevel gear 12a (shown in Figure 4) is attached to one end of the rotating shaft.
is permanently installed. This bevel gear 12a has a base plate 10.
A bevel gear 13 pivotally supported is engaged with the gear 13.
A gear 14, which is also pivotally supported on the base plate, meshes with the spur teeth of the base plate.

A through hole is formed in the center of the gear 14, and a female thread is cut in the through hole with the rotation center of the gear 14 as the axis. A male thread cut on the guide shaft 15 is screwed into this female thread.

The guide shaft 15 extends in the optical axis direction, and its end is fixed to the substrate IC of the camera body 1, and its tip is connected to the through hole 1 of the plywood 10.
0b so as to be slidable in the axial direction.

A bevel gear 12b is fixed to the other end of the rotating shaft of the motor 12.

A bevel gear 16 discontinued on the base plate 10 is engaged with this bevel gear 12b, and an input gear 17a of a gear train 17 discontinued on the base plate 10 is engaged with the spur tooth portion of this gear 16.

A through hole is formed in the center of the output gear 17b of the gear train 17, and a female thread is cut in this through hole with the rotation center of the gear 17b as the axis. A male thread cut on the guide shaft 18 is screwed into this female thread. The guide shaft 18 is
It extends in the optical axis direction, and its end is fixed to the substrate IC of the camera body, and its tip is inserted into the through hole 10c of the base plate 10 so as to be slidable in the axial direction.

The amount and direction of rotation of the gear 14, 17b with respect to a certain amount of rotation of the motor are set to be equal, and the conditions for the screwing of the gear 14 and the guide shaft 15 and the screwing of the gear 17b and the guide shaft 18 are also set. are set equal. A guide shaft 18 extending in the optical axis direction is also implanted in the substrate 1c. Guide shaft 18
is inserted into a through hole 10e of an overhang 10d protruding from the back surface of the base plate 10 and a through hole 10f of the base plate 10 so as to be slidable in the axial direction.

With this configuration, when the motor 12 rotates, the gear 14 and the guide shaft 15 are screwed together, and the gear 17b and the guide shaft 18 are screwed together.
By screwing together, the plywood lO moves in parallel in the optical axis direction while remaining perpendicular to the optical axis, and the main optical system 3 fixed thereto
The aperture/shutter device 11 is displaced in the optical axis direction between an extended position and a retracted position.

A printed circuit board 20 is fixed to the right side surface of the base plate 10. A conductive land 20 is provided on the surface of this printed circuit board 20.
a to 20c are provided, and three sliding contact pieces 21 to 23 fixed to the camera body are slidable on these, respectively. The sliding contact piece 21 and the conductor land 20a make up the switch SW3, the sliding contact piece 22 and the conductor land 20b make up the switch SW4, and the sliding contact piece 23 and the conductor land 20c make up the switch SW3.
and configure the switch 5I115, respectively.

The switch SW3 is turned OFF when the main optical system 3 is in the retracted position, the switch SW4 is turned OFF when it is in the extended position, and the switch SW5 is turned OFF when it is located between the retracted position and the extended position. The switches SW3 and SW4 function as limit switches, and cut off the power supply to the motor 12 when the main optical system 3 is displaced to the retracted position or the extended position.

The switch SW5 is a switch that prevents the shutter release from being performed when the main optical system 3 is at a position between the above two positions and a subject image cannot be formed on the film surface, and is a switch that prevents the shutter release from being performed. This is a switch for cutting off power supply to the circuit 31 (shown in FIG. 8).

In addition, the film 24 has a shooting amount 1J1 opened on the substrate 1c.
It is arranged behind d.

FIG. 4 is a perspective view of a sub-optical system attachment/detachment mechanism provided on the back surface of the base plate 10.

In the figure, a reduction gear train 25, a cam gear 26, and a drive member 27 are pivotally supported on the back surface of the base plate 10, and the drive member 27 holds the sub optical system 4. Reduction gear train 2
The input gear 25a of No. 5 meshes with the spur tooth portion of the bevel gear 13, and the final gear 25b of the reduction gear train 25 meshes with the cam gear 26.

The cam gear 26 and the drive member 27 are coaxial, and are coupled via a front cam 28a provided on the end surface of the cam gear 26.

The reduction ratio of the reduction gear train 25 is set as follows. That is, when the main optical system 3 is in the extended position, the sub optical system 4 is placed in the insertion position (shown by a solid line) inserted into the photographing light beam, and when the main optical system 3 is in the extended position, the sub optical system 4 is placed in the inserted position (shown by a solid line). 4 is placed at a retracted position (indicated by a two-dot chain line) where it is retracted from the photographing light beam.

FIG. 5 shows a sectional view of the sub-optical system mounting/detaching mechanism.

In the same figure, the main optical system 3 and the diaphragm/shutter device 11 are fixedly installed on the plywood lO in front of the aperture 10a.
A positioning means 28 for the sub optical system 4 is formed behind a. The positioning means 28 includes an inner cylindrical surface 28a having the optical axis of the main optical system 3 as its axis, a dome-shaped guide surface 28b, and an abutment surface 28c perpendicular to the optical axis of the main optical system 3.

This positioning means 28 can hold a holding cylinder 4a that integrally holds the sub optical system 4, and when the holding tube 4a is held, the optical axis of the sub optical system 4 is aligned with the light of the main optical system 3 in the extended position. The sub optical system 4 is aligned with the optical axis, and the sub optical system 4 is positioned at a predetermined position in the direction of the optical axis.

This front axis alignment is performed by inserting the small cylinder 4c protruding from the front end surface 4b of the holding cylinder 4a into the inner cylinder surface 28a of the positioning stage f 28, and the positioning in the optical axis direction is performed by inserting the small cylinder 4c protruding from the front end surface 4b of the holding cylinder 4a.
This is done by the end surface 4b of the positioning means 28 coming into contact with the contact surface 28c of the positioning means 28.

The drive member 27 is slidably supported in the axial direction by a fixed shaft 10g embedded in one plywood lO via a bearing portion 27a. A circumferential groove 27b is formed in the drive member 27 to accommodate the sub optical system 4 in a loosely fitted state.

A flange 4 is provided on the outer periphery of the holding cylinder 4a of the sub-optical system 4 over the entire circumference.
d, and a coil spring 29 is inserted between the inner circumferential groove 27b and the collar 4d. This spring 29 is
Positioning means 2 for sub-optical system 4 brought to the insertion position
It functions to bias in the direction of contact with 8.

A cam gear 26 is also pivotally supported on the shaft 10g, and a sliding contact portion 27c provided at one end of the drive member 27 can slide into a front cam 28a formed on this end surface.

A collar 10h, 1 is provided on the shaft Log so as to sandwich the bearing portion 27a.
A spring 30 is inserted between the collar 10h and the drive member 27. The spring 30 functions to press the sliding portion 27c of the drive member 27 against the cam 28a or to press the front end surface of the bearing portion 27a against the collar 10i.

Members 10j and 10k are implanted in the base plate 10 to lock the free end 27d of the drive member 27, and the locking member 10j locks the drive member 27 when the sub optical system 4 is brought to the insertion position. The locking member 10 locks the swinging of the drive member 27 when the sub optical system 4 is brought to the retracted position.

Further, near the end of the locking member 10, there is a circular hole 10 into which the small cylinder 4C of the sub optical system 4 brought to the retracted position is loosely fitted. L is provided. 4. FIG. 5 shows the state when the sub-optical system 4 is in the insertion position and in the fully inserted position in which it is engaged with the positioning means 28. The sub optical system 4 also takes the following positions.

That is, there is an incompletely inserted position where the small cylinder 4c is pushed up by the front cam 28a and does not engage the positioning means 28, although it is in the insertion position, and the small cylinder 4c is pushed up by the front cam 26a although it is located above the circular hole 10. and a completely retracted position in which the small cylinder 4C has not fallen into the circular hole 11.

FIG. 6 shows a cam diagram of the cam 28a.

The cam 26a has a lifting height of O as the rotation angle e changes from O to el.
A first flat section A where the head does not change from el to e2, a first slope section B where the head increases linearly from O to hl from el to e2, and a second slope section B where the head does not change at hl from e2 to e3. It consists of a flat section ffJJc and a second slope section where the lifting height decreases linearly from hl to O from e3 to 360°.

The cam 28a has three effects on the sub-optical system 4.

The first effect is to displace the sub optical system 4 in the optical axis direction of the main optical system 3 between the complete insertion position and the incomplete insertion position.

The second effect is to displace the sub optical system 4 between the incomplete insertion position and the incomplete retraction position in a direction transverse to the optical axis of the main optical system 3. The third effect is to displace the sub optical system 4 in the optical axis direction of the main optical system 3 between the incompletely retracted position and the completely retracted position. The details will be described later.

FIG. 3 shows a finder magnification switching device.

The first finder optical system 5 is in the insertion position.

As shown in the figure, a rack 51 is erected on the back surface of the base plate 10, and the rack 51 is attached to a guide shaft 51a whose base end is implanted in the base plate 1c and whose front part is loosely fitted into the base plate 10. being guided.

The transmission shaft 5 is attached to the rack $51b carved in the rack 51.
A pinion 52a fixed to the lower end of 2 is engaged,
The transmission shaft 52 passes through a partition plate that blocks light between the photographing optical system and the finder optical system.

A spur gear 52b fixed to the upper end of the transmission shaft 52 is meshed with a reduction gear 53a fixed to the cam plate 53.

A cam groove 54 is carved on the top surface of the cam plate 53.
A driving tooth 53b and a continuous sliding contact edge 53d of the driving tooth 53C2 are formed on the peripheral edge, with one tooth missing from the driving tooth 53b.

A switching drive member 55 is provided adjacent to the cam plate 53 and is pivotally supported by the finder storage portion 1a via a swing shaft 55a. The switching drive member 55 has activation teeth 55 corresponding to the activation teeth 6Ji53b and drive teeth 53c of the cam plate 53.
b, sector-shaped portion 55d having drive teeth 55c, and swing shaft 55;
A cam portion 55g consisting of a first cam surface 55e in a substantially radial direction formed around a and a second cam surface 55f which is a circumferential surface, and a cam portion 55g extending radially from a swing shaft 55a. It consists of an arm 55h.

A first objective lens 56 is fixed to the tip of a support arm 55i extending upward from the tip of the swing arm 55h, and this first objective lens 56 forms a first finder optical system.

The switching drive member 55 is biased clockwise when viewed from the north in FIG. 3 by a spring 55 stretched between it and a pin protruding from the finder housing 1a.

A second objective lens 57 constituting a second finder optical system is swingably supported on a rectilinear frame 58 via a swing shaft 57a.
The rectilinear frame 58 is supported within the finder housing la so as to be movable rectilinearly in the optical axis direction of the finder optical path.

A locking pin 5 protrudes downward/directly from the second objective lens 57
7b and a locking bin 58a protruding downward from the straight frame 58.
A spring 58b is stretched between the second objective lens 57 and
is biased clockwise as seen from the north in Figure 3.
7b is held in contact with the lower side 58c of the rectilinear frame 58 and facing forward.

Further, a retaining rod 57c protrudingly provided on the lower end surface of the second objective lens 57 extends downward, and its tip is connected to the switching drive member 57c.
It engages with the cam portion 55g of No. 5. The rack 51. Transmission shaft 52. Cam plate 53. Switching drive member 55. The engagement rod 57c and the like constitute a second finder optical system driving means.

On the other hand, rack 51. Transmission shaft 52. The cam plate 53 degree switching drive member 55 and the like constitute a first finder optical system drive means.

The cam groove 54 of the cam plate 53 has a rocking/<-59
A driven pin 5θa protruding from is engaged with the driven pin 5θa. The swing lever 58 has its base end pivoted to the finder housing 1a via a pivot 59b, and is connected between a pin 513c projecting further from the pivot 59b to the end and a pin 1b fixed to the finder housing 1a. A toggle spring 59d that holds the swing lever 58 in the telephoto position and the wide-angle position is tensioned.

The cam groove 54 of the cam plate 53 includes a first circumferential groove 54a that does not operate the driven pin 59a, a drive groove 54b that moves and swings the driven pin 59a, and a drive groove 54b that moves the driven pin 59a to swing the 8-58. It is configured by a second circumferential groove 54c that does not allow

A substantially U-shaped groove 59e is formed at the tip of the swing lever 58, and a vertical movement connecting arm 58d extending downward from a linear movement connecting arm 58d that projects rearward from the linear frame 58 is formed in the groove 59e. The tip of the rod 58e is engaged.

FIG. 8 shows a motor control circuit for driving the optical systems 3 and 4 of this embodiment.

In the figure, the motor 12 is driven by three power supply circuits.

The first path is a path from the positive electrode of the power source E to the switch 5W3 to the switch 5W7a to the motor 12 to the switch 5il1 b to the negative electrode of the power source E. By supplying power through this path, the motor 12 rotates, displacing the main optical system 3 to the retracted position and displacing the sub optical system 4 to the retracted position.

The second path is a path from the positive electrode of the power source E to the switch SW4 to the switch 5W8a to the motor 12 to the switch 5W8b to the negative electrode of the power source E. By supplying power through this path, the motor 12 rotates in the opposite direction to that in the first path, displacing the main optical system 3 to the feeding position and displacing the sub optical system 4.
to the insertion position.

Here Fee 2 5W7a, 5W7b, 5W8a, SW
8b is a semiconductor switch whose opening/closing is controlled by a logic circuit 40 (shown in FIG. 9), which will be described later.

The third path is the automatic focus adjustment/shutter control circuit 31
and the motor 12, and this control circuit 31
The output of the motor 12 causes the motor 12 to rotate forward and reverse, moving the optical system back and forth in the optical axis direction and bringing the optical system into focus.

In the power supply path of this control circuit 31, switches 5W1a and SW5 connected in series are inserted. switch 5W
A semiconductor switch 1a is controlled by the switch swi and is opened and closed in the same phase as the switch swi, and is turned ON only when a dustproof cover (not shown) is in the open position. The switch SW5 is turned on only when the main optical system 3 is at the extended position and the retracted position (when the sub optical system 4 is at the fully inserted position and the fully retracted position). These prevent automatic focus adjustment and shutter operation when the dustproof cover and optical systems 3 and 4 are in positions inappropriate for photographing.

FIG. 9 shows a logic circuit 40 that controls the operation of the motor control circuit of FIG. This logic circuit 4° has a pair of input terminals 40a, 40b and a pair of output terminals 40c, 40.
d. The input terminal 40a is connected to the above switch SW.
The input terminal 40b is connected to the switch S between I and the grounding resistor.
Between W2 and the grounding resistor, the output terminal 40c is connected to the control terminal of the switches 5W7a and 5W7b, and the output terminal 40d is connected to the control terminal of the switches 5W7a and 5W7b.
are connected to the control terminals of the switches 5W8a and 8b, respectively.

The input terminal 40a is at the old GH level when the switch 5till is ON, that is, when the dustproof cover is in the open position, and is at the Low level when the switch SWI is OFF, that is, when the dustproof cover is in the closed position. The input terminal 40b is at the old GH level when the switch SW2 is ON, that is, when the focal length selection member 2 is at the telephoto position, and is at the Low level when the switch SW2 is OFF, that is, when the focal length selection member 2 is at the wide-angle position. becomes.

When the output terminal 40c is at High level, the above switch S
Turn both %17a and 5W7b ON, and turn them both OFF during Low L/Bevel. When the output terminal 40d is at a high level, the switches 5W8a and 5W8b are both turned on and set to L, and both of the switches 5W8a and 5W8b are set to a low level.

An input terminal 40a of the logic circuit 40 is connected to one input terminal of an exclusive OR circuit 40e and one input terminal of a NOR circuit 40f. The input terminal 40b is connected to the other input terminal of the exclusive OR circuit 40e and the other input terminal of the NOR circuit 40f.

The output terminals of both circuits 40e and 40f are connected to both input terminals of OR circuit 40g. OR circuit 4
The output terminal 0g is connected to the output terminal 40c of the logic circuit 4o and the input terminal of the inverter 40h.
The output terminal 0h is connected to the output terminal 40d of the logic circuit 4o.

The table below shows the position of the dustproof cover, the position of the focal length selection member 2, and the switch SWI that changes depending on these positions.
, the state of SW2, the input terminals 40a, 4 of the logic circuit 4o
0b, output terminal 40c, 40d level, switch 5W
The relationship between the states of 7a, 5W7b, 5W8a, and 5W8b, and the positions of the main optical system 3 and the sub optical system 4 is summarized.

(1) As shown in Fig. 1, when the dustproof cover is in the open position, the focal length selection member 2 is in the telephoto position, and the main optical system 3 is already in the extended position, both switches SWI and 3112 are ON. Therefore, the input terminal 40 of the logic circuit 4°
Both a and 40b are at the old gh level. The output terminals of exclusive OR circuit 40e and NOR circuit 40f are Low.
level, and the output terminal f of the OR circuit 40g also becomes low level. Output terminals 40c and 40d of the logic circuit 4o become Low and High/Bell, respectively.

As a result, the switches 5W7a and 5W7b shown in FIG.
is ON to tt6° Since the main optical system 3 is in the extended position, it is shown in Fig. 3. 3. SW4. SW
5 Ha, turn on and off.

There are 0N(7)-like 71 d. Switch 5W7a, 5W7
Since b is OFF, the first path is not formed,
Since the switch SW4 is OFF, the second path is not formed either.

In this case, the main optical system 3 is at the feeding position, and the sub optical system 4 is at the fifth position.
As shown in the figure, they each remain stationary in the fully inserted position in which they are fully engaged with the positioning means 28.

Both optical systems constitute a composite optical system, whose focal length is in the telephoto range. Switches 5Wla and SW5 are both O.
Since it is N, the automatic focus adjustment trI-shutter control circuit 3 is in an operable state, and photography with the telephoto optical system is possible. FIG. 1 shows the state at this time.

In response to the photographing start operation, the motor 12 receives power through the third path and rotates, displacing the optical systems 3 and 4 in the optical axis direction from close range to infinity in the telephoto region, and focusing tAtH.

During the rotation of the motor 12 for focus adjustment in this telephoto range, the front end surface of the bearing portion 27a of the drive member 27 is in contact with the flange 10i due to the biasing force of the spring 3o, so that the sliding contact portion of the drive member 27 2? c merely faces the t51 flat section 1iJ7A of the cam 26a and does not make contact with it. Therefore, the sliding contact portion 27c does not become a load on the motor 12.

Further, the finder optical system also has a first objective lens 58 located in front of a second objective lens 57, and FIGS.
It is in a telephoto state as shown in Figure 514 (^).

97 Main optical system for focus adjustment for distant photography 3. Both the sub-optical system 4 and the plywood 10 are displaced back and forth.

When the force L/plate 53 rotates as a result, the vertical rod 58e of the rectilinear frame 58
e, and the rear end of the guide groove 1f provided in the finder housing 1a, and the starting teeth 53b of the cam plate 53 and the starting teeth 55b of the switching drive member 55 are separated from each other and swing. The vertical pin 59a of the lever 59 moves within the first circumferential groove 54a of the cam 1III54 of the cam plate 53, and the vertical pin 58 is attached to the side wall of the first circumferential groove 54a.
Since point a does not touch, the finder optical system will not be switched or vibrated due to operation.

(2) When the focal length selection member 2 is switched to the wide-angle position from the state shown in FIG. 1, the switch SW2 is turned off and the input terminal 40b of the logic circuit 40 becomes Low level. Since the output terminal of the exclusive OR circuit 40e becomes the old gh level, the output terminal of the OR circuit 40g is inverted to the old gh level, and the output terminal 40c of the logic circuit 40,
40d are inverted to the old GH and Low levels, respectively.

As a result, the switches 5W7a and 5W7b shown in FIG. 8 are ON, and the switches 5W8a and 5W8b are OFF.
Tonal. Since the main optical system 3 is in the extended position, the switches SW3, SW4, SW5 are turned on and off as shown in FIG.

It is in the ON state, and switches 5W7a and 5W7b are ON.
The path i1 is formed, and the motor 12 is started. Therefore, the main optical system 3 begins to be displaced from the extended position toward the retracted position.

The sub-optical system 4 is displaced in the optical axis direction from the complete insertion position (shown in FIG. 5) where it engages with the positioning means 28 during the initial rotation of the motor 12, to the incomplete insertion position where it does not engage with the positioning means 28. Displace. This displacement in the optical axis direction is caused by the movement of the cam 26a into the third position.
This is done by rotating clockwise from the state shown in the figure and pushing the sliding portion 27c of the drive member 27 in the first slope section B.

When the sub optical system 4 reaches the incomplete insertion position, the positioning means 28
When the drive member 27 is disengaged from the drive member 27, it becomes swingable in a direction transverse to the optical axis, so as the motor 12 continues to rotate, the sliding portion 27c is pushed by the first slope section B and the main optical system It swings clockwise in a plane that crosses the optical axis of No. 3.

At this time, the end face of the small cylinder 4C of the sub-optical system 4 slides on the back surface 10m of the plywood 10 perpendicular to the optical axis of the main optical system 3 while swinging in the same direction. When the main optical system 3 approaches the retracted position, the free end 27d of the drive member 27 comes into contact with the IF member 10k and is prevented from swinging, and the sub optical system 4 moves toward the circular hole 10k.
It reaches the incomplete retraction position where it is not inserted into 1.

Since the motor 12 continues to rotate after that, the drive member 2
The sliding contact portion 27c of No. 7 ascends the first slope section B of the cam 28a and reaches the second flat section C. Subsequently, sliding contact part 2
7c slides down the second slope section, but on the way, the front end surface of the receiving shaft portion 27a comes into contact with the collar 10i, so the sliding contact portion 27c separates from the cam 28a.

It faces the first flat section A, but reaches a state where it does not come in contact with it.

Due to the accompanying displacement of the driving member 27 in the optical axis direction, the small cylinder 4C of the sub-optical system 4 is inserted into the circular hole 10 of the base plate 10, and the end surface 4b of the holding cylinder 4a comes into contact with the edge of the circular hole 10JI. They touch each other and reach the fully retracted position. At this time, the main optical system 3 has reached the retraction position.

Note that after the front end surface of the bearing portion 27a comes into contact with the collar 10i and the driving member 27 stops displacing in the optical axis direction,
The biasing force for inserting the sub optical system 4 into the circular hole 10 is provided by the spring 2.
9 supplies.

When the main optical system 3 reaches the retraction position, the switches SW3, SW4, and SW5 shown in FIG. 4 are turned OFF, respectively.
ON.

becomes the state of When switch S%l13 turns OFF,
The first path is cut off and power supply to the motor 12 is stopped. Therefore, the main optical system 3 is stationary at the retracted position, and the sub optical system 4 is stationary at the completely retracted position, so the optical system is composed only of the main optical system 3, and its focal length is in a wide-angle range.

Further, since the switches SW1 and SW5 are both ON, the automatic focus adjustment/shutter control circuit 31 is in an operable state, and photographing with a wide-angle optical system is possible.

In response to the photographing start operation, the motor 12 receives power through the third path and rotates, displacing the main optical system 3 in the optical axis direction between close range and infinity in the wide-angle area, thereby adjusting the focus. During the rotation of the motor 12 for focus adjustment in this wide-angle region, the sliding portion 27c of the drive member 27 only faces the first flat section A and does not contact it, so the drive member 27 does not move and the sub-optical System 4 remains in the fully retracted position.

Then, in response to the change in the above state, the finder optical system is switched as follows by the finder magnification switching device. That is, the first finder optical system 5 is moved from the insertion position to the retracted position.

Since the base plate 10 moves back a lot due to switching from the telephoto state to the wide-angle state, the rack 51 moves back a lot, and the rack teeth 51b, pinion 52a, transmission shaft 52. Spur gear 52
b. The cam plate 53 is largely rotated by the path of the reduction gear 53a.

The rotation of the cam plate 53 causes the activation tooth 53b to push the activation tooth 55b of the fan-shaped portion 55d of the switching drive member 55, and further the driving tooth 53c and the driving tooth 55c engage with each other.
b and the driving tooth 53c and between the starting tooth 55b and the driving tooth 5.
There is one tooth missing between it and 5c, so they start meshing smoothly without interference.

Then, as shown in FIG. 11, the switching drive member 55 is rotated, so the tip of the engagement rod 57c is pushed against the first cam surface 55'e, and the second objective lens 57 is moved along the swing axis 57a. Rotate the center by a set angle counterclockwise when viewed from above in FIG.
When reaching f, the second objective lens 57 is held at a constant angle.

In synchronization with the angular displacement of the second objective lens 57, the first objective lens 5B draws an arc around the cam part 55g together with the switching drive member 55, and brushes the edge of the second objective lens 57 when it faces the front. 12 and 14 (B
).

At this time, the second objective lens 57 is housed in the space 7 formed adjacent to the narrowed part of the finder optical system.

Thereafter, the driven pin 59a of the swing lever 59 reaches the area of the drive groove 54b from the first circumferential groove 54a of the cam groove 54.

Then, the swing lever 58 rotates clockwise about the pivot shaft 511b when viewed from above in FIG.

Split*5ae, driven rod 58e, direct-acting connecting arm 58
The rectilinear frame 58 is pushed forward via d.

When the rectilinear frame 58 is pushed forward, the tip of the retaining rod 57c comes off the second cam surface 55F of the switching drive member 55, so the second objective lens 57 returns to face the front and cam portion 55g. Without interference, the rectilinear frame 58 and the second objective lens 57 are pushed out to the original position of the first objective lens 56, replacing the first objective lens 56, and the swing lever 59
is inverted and held at the wide-angle position by a toggle spring 59d.
The state shown in FIG. 3 to FIG. 14(C) is reached, and a wide-angle finder optical system is formed.

In the wide-angle state, even when the cam plate 53 is rotated for focus adjustment, the vertically moving rod 58e of the rectilinear frame 58 is held between the wall and the front end of the guide fR1f provided in the finder housing 1a. There is.

The driven pin 59a of the swing lever 58 moves within the range of the second circumferential groove 54c of the cam groove 54 of the cam plate 53, and the driven pin 58a does not come into contact with the side wall of the second circumferential groove 54c. Since the vertical pin 58a moves within the area of the second circumferential groove 54c of the cam groove 54, the swing lever 5
9 does not swing, and the fan-shaped portion 5 of the switching drive member 55
The end of the drive tooth 55c of 5d is the sliding contact edge 5 of the cam plate 53.
3d, the second objective lens 57 is not displaced and is stably held.

FIG. 7 is a diagram showing the relationship between the amount of extension of the base plate 10 and the switching state of the photographing optical system and the finder optical system,
The state x of the photographing optical system and the state Y of the finder optical system are made to correspond, with W representing the telephoto state and T representing the wide angle state.

As shown in the figure, even if the amount of plywood lO is small, it is in a correspondingly stable wide-angle state, and the plywood lO is in a stable wide-angle state in area (a).
0 is movable between infinity ■ and close distance lIN in the wide-angle state. When you perform an operation to switch the state, area (b)
The direction of both optical systems is shifted to the telephoto state via the area (C
), the lens enters a stable telephoto state, and can move within region (c) between infinity (2) and close range glN in the telephoto state. The same applies when switching from a telephoto state to a wide-angle state.

(3) When the dustproof cover is displaced from the open position to the closed position from the telephoto state, the switch SWI is turned OFF, the input terminal 40a of the logic circuit 40 becomes Low level, and the output terminal of the exclusive OR circuit 40e is the old GH
level. The following operation is the same as (2), and even though the focal length selection member 2 is at the telephoto position, the main optical system 3
is displaced from the extended position to the retracted position, and the sub optical system 4 is displaced from the fully inserted position to the fully retracted position.

When the main optical system 3 is displaced to the retracted position, the dustproof cover can be displaced to the closed position. When the dustproof cover reaches the closed position, switch 5W1, which is in phase with switch S
Since a is turned off, the power supply to the automatic focus adjustment/shutter control circuit 31 is cut off, and photographing becomes impossible.

Similarly, the finder optical system is also switched from the telephoto position to the wide-angle position.

(4) When the dustproof cover is moved from the wide-angle state to the closed position, the switch 5W1a, which is in phase with the switch swi,
Since it is F, the automatic focus adjustment/shutter control circuit 31
The power supply to the camera will be cut off, making it impossible to take pictures.

(5) When the focal length selection member 5 is switched from the wide-angle state to the telephoto position, the switch SW2 is turned on, and the input terminals 40a and 40b of the logic circuit 40 are both at the old gh level. Exclusive OR circuit 40e, Noah circuit 4
Since the output terminals 0f are both at a low level, the output terminal of the OR circuit 40g is inverted to a low level, and the output terminals 40c and 40d of the logic circuit 40 are I and ow, respectively.

Reverse to old GH level.

As a result, switches 5W7a and 5W7b shown in FIG.
is turned OFF, and switches SI+18a and 5W8b are turned ON. Since the main optical system 3 is in the retraction position, switch SW3 is activated.

SW4 and SW5 are OFF, ON, and ON, respectively.
is in a state of

Since the switches 5W8a and 5W8b are ON and the switch SW4 is ON, the second path is formed,
The motor 12 begins to rotate in the opposite direction to that in (2). Therefore, the main optical system 3 begins to be displaced from the retracted position toward the extended position.

With this initial rotation of the motor 12, the sub optical system 4 is displaced from the completely retracted position in the optical axis direction, out of the circular hole 10, and is displaced to the incompletely retracted position C (shown in FIG. 8). This displacement in the optical axis direction is caused by the rotation of the cam 28a and pushing up the sliding contact portion 27c of the second slope section D/drive member 27. When the sub optical system 4 comes out of the circular hole 10sL, the drive member 27 becomes swingable in a direction transverse to the optical axis of the main optical system 3.

As the motor 12 continues to rotate, the sliding portion 27c is pushed in a direction across the optical axis by the second sloped section, so the drive member 27 swings in the same direction, causing the small cylinder 4c of the sub optical system 4 to move. While the end surface slides on the back surface 1O11''2 of the base plate 10, it moves from the incompletely retracted position to the incompletely inserted position.

When the main optical system 3 approaches the extended position, the free end 27d of the drive member 27 comes into contact with the locking member 10j, its swinging is prevented, and the sub optical system 4 stops at the incompletely inserted position. Since the motor 12 continues to rotate thereafter, the sliding portion 27c of the drive member 27 ascends the second slope section of the cam 26a and reaches the second flat section C.

Next is the sliding contact part 2? c slides down the first slope section B, but on the way, the front end surface of the bearing section 27a comes into contact with the collar 10i, so the sliding section 27c separates from the cam 28a and faces the first flat section A, but makes contact with it. It reaches a state where it doesn't.

Due to the accompanying displacement of the driving member 2.7 in the optical axis direction, the small cylinder 4C of the holding cylinder 4a of the sub optical system 4 is moved to the positioning means 28.
The end face 4b of the holding cylinder 4a abuts against the abutment face 28c of the positioning means 28, and the end face 4b of the holding cylinder 4a abuts against the abutment face 28c of the positioning means 28, and is inserted into the guide face 28a as shown in FIG. At this point, the positioning of the sub optical system 4 is completed. At this time, the main optical system 3 has reached the feeding position.

Note that after the drive member 27 stops displacing in the optical axis direction due to the bearing portion 27a coming into contact with the collar 10i, the biasing force for engaging the sub optical system 4 with the positioning means 28 is generated by the spring 2.
9 supplies.

When the main optical system 3 reaches the extended position, the switches SW3, SW4, and SW5 are in the ON, OFF, and Off states, respectively, as described in (1). switch SW
4 is turned off, the second path is cut off and power supply to the motor 12 is stopped. Therefore, as shown in FIG.

The main optical system 3 is stationary at the extended position, and the sub optical system 4 is stationary at the fully inserted position, forming a composite optical system whose focal length is in the telephoto range. Further, since the switches 5W1a and 3w5 are both ON, the automatic focus 'JR' mode/shutter control circuit 31 is in an operable state, and photography with the telephoto optical system is possible.

In response to the above switching operation, the finder optical system is switched from the wide-angle state to the telephoto state.

That is, when the main optical system 3 and the sub-optical system 4 are switched to the telephoto state, the base plate 10 moves forward a lot, so that the cam plate 53 rotates a lot, contrary to the above. As a result, the vertical movement pin 59a of the swing lever 59 reaches the drive groove 54b from the second circumferential groove 54c of the cam groove 54, and the swing lever 5!3 moves from the state shown in FIGS. 13 and 14(C). The second objective lens 57 and the rectilinear frame 5 rotate counterclockwise.
Pull 8 back.

When the second objective lens 57 and the rectilinear frame 58 move backward, the tip of the engagement rod 57c switches to the cam portion 55 of the switching drive member 55.
12 and 14 CB) in which the second objective lens 57 is held in an angularly inclined state about the swing axis 57a.

In synchronization with this, the drive tooth 53c meshes with the drive tooth 55c, the switching drive member 55 is rotated clockwise, and the first objective lens 5B housed in the space 7 draws an arc around the swing axis 55a. 11 and 1.
The state shown in FIG. 4 (A) is reached. Next, the tip of the retaining rod 57c reaches the first cam surface 55e of the cam portion 55g, and finally the second objective lens 57 faces forward, and the rectilinear frame 58 returns to the front of the second objective lens 57. The telephoto state shown in FIG. 10 is reached.

(6) When the dustproof cover is moved from the state where the dustproof cover is covered to the open position in the telephoto state, the switch SWl is turned on, and the input terminal 4.0a of the logic circuit 40,
40b are both at the old gh level. The following operation is the same as that described in (5).

According to the second embodiment, since the switching of the photographing optical system, the switching of the finder optical system, and the focus adjustment can be performed by sequentially using the rotation of one motor, the driving source of the funeral can be used. This has the advantage that multiple drives can be performed and the camera can be made smaller.

"Effects of the Invention" According to the finder magnification switching device according to the present invention, the finder is configured by a plurality of finder optical systems, and as the first finder optical system is inserted into and removed from the finder optical path,
The second finder optical system moves forward and backward in the direction of the optical axis of the finder, and after the wTJ1 finder optical system retreats from the insertion position, it is displaced to the position it occupied.
The optical system can be effectively switched by a small movement of the finder optical system, and a finder magnification switching device with good performance and fit in a small space can be obtained.

[Brief explanation of drawings]

1 to 14 show an embodiment of the present invention, in which FIG. 1 is a vertical cross-sectional view of the camera, FIG. 2 is a horizontal cross-sectional view of the camera, and FIG. 3 is a perspective view of the internal mechanism of the camera. Figure 4 is a perspective view of the photographic optical system switching mechanism, Figure 5 is a sectional view of the main part, Figure 6 is a cam diagram, and Figure 7 is the amount of plywood extension and the switching state of the photographic optical system and finder optical system. Fig. 8 is a motor control circuit diagram for driving the optical system, Fig. 9 is a logic circuit diagram for controlling the operation of the motor control circuit, and Fig. 10 is a plan view of the finder magnification switching device in the telephoto state. , FIG. 11 and FIG. 12 are plan views in an intermediate state, FIG. 13 is a plan view in a wide-angle state, and FIG. 14 is an explanatory diagram showing a switching state of the finder optical system. l...Camera body 1a...Finder storage section 3.
...Main optical system 4...Sub-optical system 10...Bed plate 12...Motor 2B...Cam gear 27...Drive member 51...Rack 53...Cam plate 55...Switching Drive member 56...1st objective lens 57...bdl, 2nd objective lens Fig. 1 Fig. 5 Fig. 7 (00)
Figure gM72Figure 874 (A) CB) (C)

Claims (1)

[Scope of Claims] (1) In a viewfinder magnification switching device for a camera having a photographing optical system capable of changing the focal length; a first finder optical system; a second finder optical system movable in the optical axis direction within the finder optical path; a first finder that pushes back the first finder optical system in conjunction with a switching operation of the photographing optical system. Optical system driving means: A second finder optical system driving means for displacing the second finder optical system to the position occupied in response to the retracting operation of the first finder optical system from the insertion position to the retracted position. A finder magnification switching device M comprising: (2. In the finder magnification switching device according to claim 1, wherein the second finder optical system is disposed so as to be displaceable from its own position on the displacement locus of the first finder optical system to a position outside the displacement locus; The second finder optical system driving means is configured to displace the second finder optical system from its own position on the displacement locus of the first finder optical system to a position outside the displacement locus while the first finder optical system advances or retreats. A finder magnification switching device characterized by: (3) In the finder magnification switching device according to claim 1, the first finder optical system driving means is configured such that the first finder optical system swings back and forth. (4) In the finder magnification switching device according to claim 1, the first finder optical system driving means is arranged adjacent to a narrowed part of the finder optical system. 1. A finder magnification switching device characterized in that said first finder optical system is retracted into a space formed by said first finder optical system.