JPH01169444A - Focal distance switching camera - Google Patents

Abstract

PURPOSE:To prevent a camera device from being larger by stopping the rotation of a switching cam with the engagement of plural stop parts with a stop means for stopping the rotation of the switching cam by engaging with said stop parts. CONSTITUTION:In case of selectively switching a photographic lens to a wide photographing position and a tele photographing position, rotary power of a motor 15 is transmitted to the switching cam 14 of a focal distance switching system and the rotary motion of the switching cam 14 is changed into a rocking motion of switching levers 12 and 13 through the pressing part of the switching cam 14, then the rocking motion of the switching levers 12 and 13 is changed into the reciprocating motion of a master lens. In such a case, the rotation of the switching cam 14 is stopped with the engagement of the stop part for stopping the rotation of the switching cam formed at unequal intervals in the peripheral direction of the cam 14 with the stop means for stopping the rotation of the switching cam by engaging with said stop part.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a focal length switching camera, and more specifically, a camera that transmits the rotational force of a motor to a focal length switching system to switch the focal length of a photographic lens. This relates to a focal length switching camera.

[Conventional technology]

Most of the recent 35mm compact cameras move the conversion lens in and out of the optical axis in conjunction with the movement of the master lens in the optical axis direction. You can select between telephoto shooting (telephoto shooting).

Also, JP-A-60-163010, JP-A No. 61-3543
As described in publications such as No. 5, the rotational force of the film feeding motor is transmitted to the focal length switching system through a clutch mechanism consisting of a planetary gear train. Some cameras have a movable tube that holds a master lens that moves.

[Problem that the invention seeks to solve]

However, for example, the forward movement of the movable tube to be paid out from the body is performed by means such as a coil spring, and the backward movement of the movable tube to be retracted into the body is performed by the rotational force of a motor or the like against the resilient restoring force of the coil spring. If this is done using the motor, there is a problem that the entire device will become larger unless the rotational force of the motor is used efficiently.

Furthermore, when converting the rotational motion of the motor into reciprocating motion via a slider crank mechanism or the like, a crank rotation control mechanism is required to stop the crank at a predetermined position. When this rotation control mechanism is constructed mechanically by means such as levers, it is necessary to rotate each of these levers by one rotation of the crank, and as above, the rotational force of the motor can be used efficiently. Otherwise, there is a problem that the entire device becomes large.

[Purpose of the invention]

The present invention is intended to solve the above-mentioned problems, and provides a focal length switching camera that can efficiently use the rotational force of the motor, suppress the increase in size of the motor, and reduce the size and weight of the entire device. The purpose is to

[Means for solving problems]

In order to achieve the above object, the present invention includes a switching cam arranged in a focal length switching system and rotated by a motor, and a plurality of stops formed on the switching cam at unequal length intervals in the circumferential direction for stopping rotation of the switching cam. a stop means that engages with the stop portion to stop the rotation of the switching cam, a pushing portion eccentrically provided on the switching cam, and a photographing lens that swings in contact with the pushing portion. A switching lever is provided to selectively switch the focal length of the lens.

[Effect]

When switching the focal length, for example, when selectively switching the photographing lens between the wide shooting position and the telephoto shooting position, the rotational force of the motor is transmitted to the switching cam of the focal length switching system, and the rotational movement of the switching cam is controlled. This is converted into a swinging motion of the switching lever via the pushing portion of the switching cam, and this swinging motion of the switching lever is converted into a reciprocating motion of the master lens.

In this case, the rotation of the switching cam is controlled by a stop portion for stopping the rotation of the switching cam formed at unequal length intervals in the circumferential direction of the cam, and a stop that engages with this stop portion to stop the rotation of the switching cam. It is made to stop by matching with the means. Therefore, since the intervals between the stop parts are of unequal length, the rotation at these intervals will be thicker on one side (smaller on the other side).As a result, due to the difference in rotation time and rotation angle between the two, The switching cam can be used to distribute the swinging of the various levers in accordance with the magnitude of the rotation time and rotation angle.For this reason, when the rotation time and rotation angle are larger, the switching cam can be used to By distributing the swinging of various levers, etc.,
These levers and the like are not swung at the same time, and the rotational force of the motor can be used efficiently.

Furthermore, for example, among the movements of the master lens in the optical axis direction, a forward movement to extend the master lens to the front of the body is performed by a coil spring that biases the master lens forward, and a switching lever is used to move the master lens backward to retract it into the body. In this case, the backward movement must be performed against the resilient restoring force of the coil spring. In this case, the rotational force for swinging the switching lever can be increased by bringing the switching lever into contact with the pushing part at a position away from the mounting shaft for backward movement, which requires more rotational force. become able to.

〔Example〕

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

In FIG. 13 showing a focal length switching camera embodying the present invention, a front plate 40 is formed with a cylindrical portion 41 that projects forward. This cylindrical portion 41 is provided with a lens cover opening/closing knob 42, and when this knob is slid, a pair of lens covers 43 and 44 are rotated to open and close the opening 45. Further, the front plate 40 is provided with a tele/wide (hereinafter referred to as Tw) switching knob 46, and when this is pushed down, it switches to wide shooting if the tele shooting state is set, or wide If set to shooting, it can be switched to telephoto shooting. Note that, as will be described later, even if the TW switching knob 46 remains depressed, there is no cyclic switching between tele photography and wide photography.

Further, above the front vi, 40, there is a well-known finder window 4.
8. Distance measuring windows 49a and 49b and a strobe light emitting section 50 are provided, and furthermore, a release button 51 is provided at the top of the front plate 40.

FIG. 1 shows an outline of the optical system. A lens holder 4 holding a master lens 3 is slidably fitted into the movable tube l, and a well-known distance measuring device (not shown) is used to move the lens along the optical axis within the movable tube 1. You can move and adjust the focus. A plate la protrudes from one side of the movable cylinder 1, and a bearing portion 1b is attached to this plate la. This bearing is in part 1b,
A guide rod 2 extending in the direction of the optical axis is inserted through the guide rod 2, and guides the movable barrel 1 as it moves between the telephoto shooting position where the master lens 3 is extended forward and the wide shooting position where the master lens 3 is moved back. . Further, a coil spring 5 is inserted through the guide shaft 2, and urges the movable barrel 1 toward the telephoto shooting position.

A conversion lens 6 is disposed behind the movable barrel 1, and the conversion lens 6 is moved in and out of the optical axis of the master lens 3 by a lens insertion/extraction mechanism 7 linked to the movement of the movable barrel 1. This lens entrance/exit mechanism 7
shows the arm 7 with the conversion lens 6 attached to the tip.
a, a lens in/out gear 7b to which this arm portion 7a is attached, and a gear 7d provided with a swinging arm portion 7c.

Further, a coil spring 7e is hung on the arm portion 7a, and biases the conversion lens 6 in the direction of inserting it into the optical axis.

Further, a behind shutter 8 is arranged behind the conversion lens 6. As is well known, this behind shutter 8 has two shutter blades 8a, 8b@m,
A bin 8d that opens and closes towards a fixed bin 8c that pivotally supports these.
By moving the two shutter blades 8a, 8b
can rotate in opposite directions to open the photographing optical path. Furthermore, a throttle device 74 is attached to the rear part of the movable cylinder 1, as shown in FIGS. 2 and 3.

A TW switching device 10 (see FIG. 4) is provided to move the master lens 3 and conversion lens 6. As will be described in detail later, in this TW switching device 10, the first switching lever 12 swings to move the master lens 3 along the optical axis and insert the conversion lens 6 along the optical axis. In order to move the master lens 3 and the conversion lens 6, as shown in FIG. 1, one end of the first switching lever 12 comes into contact with the cam surface of the second switching lever 13, and A pin 12d provided in the section is inserted into the elongated hole 1c of the plate 1a. The cam formed on the second switching lever 13 includes a non-displacement engaging portion 13a for holding the conversion lens 6 in the retracted position where it is retracted from the optical axis, and a non-displacement engaging portion 13a for rotating the conversion lens 6 to move it toward the optical axis. It consists of a displacement engagement part 13b for insertion, and these are formed continuously. When the second switching lever 13 rotates about the shaft 13c in conjunction with the first switching lever 12, it pushes the arm 7c via the slide lever 9 and rotates the gear 7d.

FIGS. 2 and 3 show a telephoto shooting state and a wide shooting state. A fixed cylinder 55 is disposed within the cylinder portion 41, and the movable cylinder 1 is slidably fitted into the fixed cylinder 55. Further, lens covers 43 and 44 shown in FIG. 13 are rotatably arranged between the cylinder part 41 and the fixed cylinder 55, and are set in a wide shooting state as shown in FIG. At times, the lens cover 43,44 can be opened and closed.

The behind shutters 8a and 8b are connected to the shutter substrate 5.
6, and opens and closes a shutter opening 56a formed in this shutter substrate 56. This shutter board 56 is fixed to the main body part 58 via screws 57, and holes 56b are provided for mounting four fixed cylinders. To attach these fixed cylinders, four legs 55b formed on the fixed cylinder 55 are inserted into the holes 56b, and the fixed cylinder 55 is fixed to the main body part 58 via screws 59.

A presser plate 6o is fixed behind the fixed tube 55, and the guide rod 2 is supported between the presser plate 60 and the fixed tube 55. Also, a plate 6 is attached to the inside of the fixed cylinder 55.
1 is firmly fixed thereto, and a lens ejecting/extracting mechanism 7 is attached thereto.

Next, the TW switching device 10 will be explained with reference to FIGS. 4 to 12. The TW switching knob 46 is connected to the TW subset slider 11 via a lever or the like (not shown).
When the TW switching knob 46 is operated, the TW subset slider 11 is slid to the left in the figure.

The TW switching device 10 includes the first switching lever 12, the second switching lever 13, a switching cam 14 for swinging the first switching lever 12, and a switching cam 14 for rotating the switching cam 14. A motor 15, a motor switch 16 that activates the motor 15 so that the switching cam 14 rotates, a motor switch lever 17 that engages with the switching cam 14 to self-hold the motor switch 16, and a switching operation force. The latch set lever 1 rotates the motor switch lever 17 to turn on the motor switch 16 when the motor switch 16 is applied.

As described above, the motor 15 is used not only for TW switching but also for film feeding (winding and rewinding), and is housed in a spool 15a that winds the film 65. The rotational force of this motor 15 is transmitted via a reduction gear train 19 to a transmission switching mechanism 20 serving as a clutch mechanism. This transmission switching mechanism 20 includes a reduction gear train 19
The sun gear 20a is connected to the sun gear 20a.
an arm (arm portion) 20b coaxially attached to the arm 20b, a planetary gear 20C rotatably attached to the arm 20b and always meshing with the sun gear 20a, and a sun gear 20
When the arm 20b is rotated in the counterclockwise direction in the figure a, the film feeding side gear 20d meshes with the planetary gear 20c at its rotation end position, and the film feeding side gear 20d meshes with the planet gear 20c at the other rotation end position. and a switching cam side gear 20e.

The arm 20b of the transmission switching mechanism 20 has a retaining portion 20f that engages with the retaining portion 27b of the TW set slider 27.
is formed. When the TW set slider 27 is at the initial position before the switching operation, this slider 27
The engaging portion 27b pushes the retaining portion 2Of of the arm 20b, and the arm 20b meshes the planetary gear 20c with the film feeding gear 20d. On the other hand, when switching TW,
The TW set slider 27 is positioned to the left in the figure, and the engaging portion 27b is separated from the engaging portion 2Of. therefore,
At the time of TW switching, the planetary gear 20c rotates clockwise due to the clockwise rotation of the sun gear 20a and meshes with the switching cam side gear 20e. They mesh together.

The film feeding side gear 20d is rotated by a gear 6 fixed to the take-up spool 15a via a gear train (not shown).
7 and a rewinding gear 68 via a one-way clutch (not shown). This rewinding gear 6
A rewinding claw 69 is fixed to the film 6.
5 is connected to a cartridge shaft 71 of a cartridge 70 containing a cartridge.

The switching cam 14 includes a gear portion 14a connected to the switching cam side gear 2゜e via an intermediate gear train 21, a circular cam portion 14b formed at the lower part of the gear portion 14a, and a circular cam portion 14b of the circular cam portion 14b. Retaining pin 14 installed eccentrically on the lower surface
c, and is rotatably attached to a substrate (not shown) via a shaft. The circular cam portion 14b has two notches 14d formed at unequal intervals in the circumferential direction, and the circumferential surface between these two notches 14d includes first and second cam surfaces 14e, 14f (see Figures 11 and 12). The notch 14d is located at the motor switch lever 1.
This is for inserting the engagement protrusion 17a of No.7. Further, the engagement pin 14c is connected to the swing regulating lever 23, as will be described later. The latch set lever 18 and the first switching lever 12 are pushed to swing these levers 23, 18, 12.

The first switching lever 12 has a locking claw portion 12a for restricting the rotation toward the telephoto side (counterclockwise rotation in the figure) of moving the movable barrel 1 forward, and an engagement pin of the switching cam 14. first and second engaging edges 12b, 1 that engage with 14c;
2e, and is rotatably attached to the substrate by an attachment shaft 12c. In addition, this first switching lever 12
As shown in FIG. 1, the movable tube 1 is always urged to rotate toward the telephoto side by a coil spring 5 that urges it forward. A swing regulating lever 23 having a locking protrusion 23a that locks onto the locking claw portion 12a is rotatably attached to the locking claw portion 12a via a mounting shaft 23b. The swing regulating lever 23 has the function of regulating the rotation of the first switching lever 12 toward the telephoto side, and is biased clockwise by a coil spring 23c. The tip 23d of the swing regulating lever 23 is connected to the switching cam 14.
is located within the movement locus of the engagement pin 14c, and is pushed by the engagement pin 14c immediately after the switching cam 14 rotates,
It is configured to be rotated by a predetermined angle counterclockwise in the figure. Therefore, when the switching cam 14 rotates, the swing regulating lever 23 is rotated counterclockwise by the engagement pin 14c, and the engagement between the engagement projection 23a and the engagement claw portion 12a is released. This allows the first switching lever 12 to rotate toward the telephoto side.

The first engagement edge 12b has the shape of a quarter arc of a circle, which is the locus of movement of the outer edge of the engagement pin 14c, and when the switching lever 12 is switched to the telephoto side (when rotated counterclockwise). ) is in contact with the retaining pin 14c. Therefore, due to the rotation of the switching cam 14, the engagement pin 14c is moved to the engagement edge 1.
2b, the first 174 of the switching cam 14
The first switching lever I2 remains in the same position until the end of the rotation, and after 1/4 rotation, the first switching lever 12 is also rotated to the telephoto side as the retaining pin 14c moves. . Further, the second engagement edge 12e is continuous with the first engagement edge 12b and is formed to protrude slightly from the first engagement edge 12b, so that the second engagement edge 12e extends toward the wide side of the switching lever 12. When switching (clockwise rotation), retaining pin 1
4c.

As shown in FIGS. 11 and 12, the non-displacement engaging portion 13a of the second switching lever 13 has a circular arc that is the movement locus of the retaining portion 12f at the tip when the first switching lever 12 rotates. It is formed into a shape, and its length is equal to that of the moving cylinder l.
This is approximately 3/4 of the travel distance of the lever 12 when it moves from the tele side position to the wide side position. The displacement engagement portion 13b is located inside the extension line of the non-displacement engagement portion 13a, and is a substantially triangular recess into which the tip engagement portion 12r of the first switching lever 12 is inserted. Therefore, when the first switching lever 12 moves to approximately 3/4 of its travel stroke, the tip engaging portion 12f and the non-displacement retaining portion 13a come into contact with each other. By simply rotating the switching lever 12, the second switching lever 13
never rotates. When the first switching lever 12 rotates 3/4 or more of its travel stroke, the tip retaining part 12f comes into contact with the displacement retaining part 13b from the non-displacement retaining part 13a, and the coil spring 5 causes the tip to move clockwise in the figure. The second switching lever 13 which is biased to the first switching lever 1
It will rotate clockwise corresponding to the rotational displacement of 2. Therefore, when the movable barrel 1 is moved by more than 374 strokes, the conversion lens 6 is inserted into the optical axis.

The motor switch lever 17 is inserted into the notch 14d of the switching cam 14, and when inserted, the switching cam 14
a locking protrusion 17a that prevents rotation of the locking protrusion 17;
When the motor switch a is located within the notch 14d, the motor switch 1
5 to OFF. This motor switch lever 17 has a retaining protrusion 17a.
is located in the notch 14d to prevent rotation of the cam 14 and turn on the motor switch 16;
The engaging protrusion 17a comes out from within the notch 14d and the switching cam 1
4 is released and the motor switch 16 is turned to O.
It is attached to the board via a shaft 17c so as to be rotatable between the unlocked position and the unlocked position N. Note that the first cam surface 14e and the second cam surface 1 of the switching cam 14
4f have unequal lengths, so the rotation angle of the switching cam 14 changes periodically according to the lengths of these cam surfaces 14e and 14f.

The latch set lever 18 engages with the retaining pin 14c to push the motor switch lever 17 toward the locking position, and also releases the motor switch lever 17 from the locking position when a switching operation force is applied. It is rotated into position. Therefore, the latch set lever 18 includes a latch holding portion 18a that is engaged with the latch lever 25 for switching the motor switch lever 17 to the locking position or the locking release position, and the latch engaging portion 18a and the latch lever. 25
After the locking (latch) is released, the engaging pin 14
The first and second engagement pushing surfaces 18b and 18c rotate the latch set lever 18 clockwise by the pushing motion of c to lock the latch retaining portion 18a and the latch lever 25 again.
It is equipped with

The first engagement pushing surface 18b is a surface that comes into contact with the engagement pin 14c when switching from the wide side to the telephoto side. Further, the second engagement pushing surface 18c is a surface for contacting the retaining pin 14c when switching from the telephoto side to the wide side.

The latch set lever 18 is attached to a mounting shaft 17c of the motor switch lever 17 below the motor switch lever 17.
It is rotatably attached to the board by a coil spring 29, and is biased counterclockwise in the figure by a coil spring 29. Furthermore, the motor switch lever 17 and the latch set lever 1
A torsion spring 24 is interposed between the motor switch lever 17 and the motor switch lever 8 to urge the motor switch lever 17 toward the locking position. Further, the latch lever 25 is urged counterclockwise in the figure by a coil spring 25a.

From the TW switching knob 46 to the motor switch lever 1
7, the leftward movement of the TW subset slider 11 is transmitted to the transmission lever 26, and the TW set slider 27.7 to which this transmission lever 26 is attached. This is done by sequentially transmitting the latch lever 25 to the latch set lever 18.

The transmission lever 26 has a claw 26a that engages with the engagement protrusion 11a of the TW subset slider 11, and is rotatably attached to the TW set slider 27 via a mounting shaft 26b. This transmission lever 26 is biased clockwise in the figure by a coil spring 26c. Further, when the transmission lever 26 is locked with the locking protrusion 11a, which is the locking part of the TW subset slider 11, and moved to near the end of its movement, it hits the transmission lever 26 and engages the lever 26 with its pawl 26a. A lock release pin 30 that swings to release the lock from the mating protrusion 11a is attached to the substrate.

The TW set slider 27 is attached to the substrate by a mounting shaft and an elongated hole through which the shaft passes, so as to be slidable in the same direction as the sliding direction of the TW subset slider 11. This TW set slider 27 and T
The W subset slider 11 is urged rightward in the figure by coil springs 2B and 29.

Next, the operation of this embodiment will be explained.

When photographing, first slide the lens cover opening/closing knob 42 to open the lens covers 43 and 44.

When the lens covers 43 and 44 are moved to the open position, the main switch (not shown) is turned on and the motor 1 is turned on.
5 drive circuit, shutter drive circuit.

The distance measuring device, strobe circuit, etc. are energized.

When the lens covers 43 and 44 are opened, the camera is in a wide-angle photographing state as shown in FIG. 3, and the movable barrel 1 is set in a position where it is retracted and enters the movement range of the arm portion 7a. In this wide shooting state, release button 5
When 1 is pressed, the distance measuring device is activated, and the lens holder 4 is moved along the optical axis according to the subject distance, and the focus of the master lens 3 is adjusted. After this focus adjustment, the behind shutter 8 is operated to expose the film 65. After this shutter operation, the motor 15 rotates, and its rotational force is transmitted to the transmission switching mechanism 20 via the reduction gear train 19. In this transmission switching mechanism 20, since the planetary gear 20c meshes with the film feeding gear 20d, the rotation of the motor 15 is transmitted to the film feeding gear 20d.

The rotation of the film feeding gear 20d is transmitted to the gear 67 via the gear train, so the take-up spool 15a rotates and winds the exposed film 65 around its outer circumference.
Then, the unexposed film pulled out from the cartridge 70 is set at the exposure position. Further, the behind shutter 8 is charged in conjunction with this film winding.

Next, when switching from the wide shooting state shown in FIG. 3 to the tele shooting state shown in FIG. 2, turn the TW switching knob 4.
Just slide 6. This TW switching knob 46
When the TW subset slider 11 is slid, the TW subset slider 11 moves to the left in the drawing, changing from the state shown in FIG. 5 to the state shown in FIG. 6. As a result, the TW set slider 27 also moves to the left in the figure via the transmission lever 26 that is engaged with the retaining protrusion 11a of the TW subset slider 11. Due to this movement, the engaging protrusion 27c of the TW set slider 27 faces the notch 17d of the motor switch lever 17, so that the motor switch lever 17 is allowed to rotate in the counterclockwise direction.

Further, the latch lever 25 is rotated clockwise by the engagement protrusion 27a of the TW set slider 27, and the locked state between the latch lever 25 and the latch set lever 18 is released. As a result, the lunch set lever 18 rotates counterclockwise in the figure, and the motor switch lever 17 also rotates counterclockwise via the torsion spring 24 applied between them, so that its retaining protrusion 17a is disconnected. Get out from within the notch 14d.

This rotation of the motor switch lever 17 turns on the motor switch 16, and the motor 15 is energized and rotates. Due to this rotation of the motor 15, the planetary gear 20c revolves around the sun gear 20a, and the switching cam side gear 20e
mesh with. As a result, the rotational force of the motor 15 is transmitted to the switching cam 14 via the switching cam side gear 20e and the intermediate gear train 21, and the switching cam 14 rotates clockwise.

Note that FIG. 6 shows the state immediately after the TW subset slider 11 has moved to the end of its movement.

As the slider 11 moves to the end of its movement, the transmission lever 26 comes into contact with the locking release pin 30 formed to protrude from the base plate and rotates counterclockwise, thereby causing the locking protrusion 11a
The locking between the and the pawl 26a is released, and the TW set slider 2
7 moves to the right in the figure and attempts to return. but,
The engagement protrusion 27c of the TW set slider 27 is inserted into the notch 17d of the motor switch lever 17 rotated to the unlocking side.
Since the TW set slider 27 becomes locked, the TW set slider 27 does not return completely. Therefore, in this state,
Since the engaging portion 27b is not in contact with the engaging portion 2Of, the state in which the planetary gear 20c is meshed with the film feeding side gear 20e is maintained. Further, although the TW set slider 27 does not return completely, the engagement between the transmission lever 26 and the engagement protrusion 11a of the TW subset slider 11 is released, and the TW subset slider 11 and the TW set slider 27 are disengaged from each other. Since the connection will be severed, press the TW switching knob 4.
Even if 6 is located on the switching side, it is possible to prevent the TW switching from being periodically switched.

When the switching cam 14 begins to rotate clockwise, the locking pin 14c first rotates the swing regulating lever 23 counterclockwise, as shown in FIG. As a result, the locking claw portion 12a of the first switching lever 12 and the locking protrusion 23a of the swing regulating lever 23 are released, so that the first switching lever 12 is rotated around the shaft 12c. rotates clockwise, and its engagement edge 12b engages the engagement pin 14c.
Contact and follow. However, since the engaging edge 12b has a quarter-arc shape, the first switching lever 12 will not be rotated toward the telephoto side until the switching cam 14 completes a quarter rotation.

During this 1/4 rotation, the engagement pin 14c of the switching cam 14 comes into contact with the first engagement pushing surface 18b of the latch set lever 1, so the latch set lever 1 rotates clockwise in the figure. and is returned to the initial position by locking the latch lever 25. By returning the latch set lever to its initial position, the spring 24 is charged, so that the motor switch lever 17 is biased clockwise in the figure.

However, since the tip of the engagement protrusion 17a is in contact with the circumferential surface of the circular cam portion 14b, the motor switch lever 17 cannot rotate clockwise in the figure, and the motor switch 1
6 is maintained in the ON state. Thereby, the motor switch 16 is self-maintained when switching from wide shooting to telephoto shooting.゛As shown in FIG. 8, the first switching lever 12 follows the movement of the retaining pin 14c due to the rotational displacement of approximately 1/4 or more of the switching cam 14 due to the resilient restoring force of the coil spring 5. Rotate counterclockwise.

As a result, the movable barrel 1 is moved forward, and the master lens 3 is set at the wide-angle shooting position. In addition, the positioning of the wide side of the movable cylinder 1 is as shown in FIG.
For example, this is done by the front surface of the movable barrel 1 hitting the fixed barrel 55. Therefore, the movable barrel 1 is moved forward and the fixed barrel 5 is moved forward.
5, the forward movement of the movable cylinder 1 is restricted, and therefore the rotation of the first switching lever 12 is also restricted at this position.

The tip 12f of the first switching lever 12 is in contact with the cam surface of the second switching lever 13 which is biased by the coil spring 7C, so that the second switching lever 13 is in contact with the first switching lever 12. linked to. However, as shown in FIG. 11, the second switching lever 13 is such that the non-displacement retaining portion 13a remains on the first switching lever 12 while the first switching lever 12 rotates by about 3/4. Since it is in contact with the one end 12f, even if the first switching lever 12 rotates, it will not follow this rotation. Then, as shown in FIG. 12, when rotating the remaining 1/4, the one end 12f of the first switching lever 12 is rotated to the second switching lever 13.
Since the second switching lever 13 faces the displacement retaining portion 13b, the second switching lever 13 rapidly rotates about the shaft 13c. When the second switching lever 13 rotates quickly, the lens ejecting/extracting mechanism 7 follows this via the slide lever 9, so the swinging arm 7a rotates counterclockwise and the conversion lens 6 Insert it into the optical axis. Therefore, when the master lens 3 moves to a position sufficiently distant from the conversion lens 6, the conversion lens 6 rotates rapidly, so that these lenses do not interfere.

As shown in FIG. 9, when the switching cam 14 rotates approximately 1/2 or more, the engaging protrusion 17a of the motor switch lever 17 is inserted into the notch 14d, and the motor switch lever 17 is moved to the initial position. Then, the motor switch 16 is turned OFF to stop the motor 15. Further, by returning the motor switch lever 17 to the initial position, the engagement projection 27c of the TW set slider 27 and the notch 17d of the motor switch lever 17 are released from the locked state, and the TW
The set slider 27 also moves rightward in the figure and returns to its initial position as shown in FIG. With this return to the initial position, the retaining portion 2O of the arm 20b of the transmission switching mechanism 20
f is pushed by the engaging portion 27b of the TW set slider 27, rotating the arm 20b counterclockwise. When this arm 20b rotates, the planetary gear 20c is forced to mesh with the film feeding gear 2Od.

Through the above operations, the movable barrel I is changed from the wide shooting state in which the movable barrel I is housed in the fixed barrel 55, as shown in FIG.
is extended forward through the fixed barrel 55, and the conversion lens 6 is inserted on the optical axis behind the movable barrel 1, thereby switching to a telephoto shooting state. This switching from the wide shooting state to the telephoto shooting state is performed using the first cam surface 14e of the switching cam 14. Since this first cam surface 14e is formed longer than the second cam surface 14f, the rotation angle and rotation time of the switching cam 14 are longer than the second cam surface 14f.
is longer than that of the cam surface 14f, and due to this increased rotation time and rotation angle, the swing regulating lever 23. The latch set lever 18 is rocked. Moreover, since these oscillations are performed sequentially,
Since these swings are not concentrated, the load on the motor that rotates the switching cam 14 can be reduced.

Next, it is possible to switch from telephoto shooting to wide shooting using the same operation as for switching from wide shooting to telephoto shooting as described above. That is, when the TW switching knob 46 is slid, the motor switch lever 17 is pulled out from the notch 14a of the switching cam 14, as shown in FIG. 10, and at the same time, the motor switch 16 is turned on. The rotation of the motor 15 is transmitted to the switching cam 14 via a gear train 19 and a transmission switching mechanism 20.

At the beginning of the rotation of the switching cam 14, the second pressing surface 18c of the latch set lever 18 is pushed via the retaining pin 14c to return the latch set lever 18 to the initial position, and the latch set lever is -18 is locked by the latch lever 25. When the switching cam 14 further rotates, the retaining pin 14C hits the engagement edge 12e of the first switching lever 12, so that it resists the resilient restoring force of the coil spring 5 that urges the movable cylinder 1 forward. The engagement pin 14c pushes the first switching lever 12 to rotate it clockwise,
The movable cylinder 1 starts to retreat. At the same time, as the first switching lever 12 is rotated toward the wide shooting side, the tip of the first switching lever 12 pushes the engagement arm 13a of the second switching lever 13. switching lever 1
3 rotates counterclockwise in conjunction with the rotation of the first switching lever 12 to retract the conversion lens 6 from the optical axis via the slide lever 9 and the lens in/out mechanism 7 (
(See Figure 1).

When the switching cam 14 continues to rotate, the first switching lever 12 is further rotated clockwise by the retaining pin 14c. When the first switching lever 12 is pushed clockwise to the maximum extent, the locking claw portion 12a of the first switching lever 12 is moved to the locking protrusion 23a of the swing regulating lever 23, as shown in FIG.
The locking claw portion 12a and the locking protrusion 23a are locked together. As a result, the first switching lever 12 is locked at the telephoto shooting position by the swing regulating lever 23, and cannot be rotated counterclockwise.

Even after this locking, the switching cam 14 rotates slightly, so
The retaining pin 14c moves to a position away from the second latching edge 12e and returns to the state shown in FIG. 5.

The switching cam 14 and the first switching lever 12
When returning to the state shown in the figure, the motor switch lever 17 enters the notch 14d of the control cam 14, so the motor switch 16 is turned off and the TW set slider 20 also returns to its initial state. With this TW set slider 20,
The planetary gear 20c is removed from the switching cam side gear 20e and is forcibly meshed with the film feeding side gear 20d. The switching from the telephoto shooting state to the wide shooting state described above is performed using the second cam surface 14'' of the switching cam 14. Since the master lens 3 is brought into contact with the mounting shaft 12c of the switching lever 12 on the far side when switching from the telephoto shooting position to the wide shooting position, the first switching lever 12 is swung with a large torque. Therefore, the first switching lever 12 can be easily swung against the resilient restoring force of the coil spring 5 that urges the movable cylinder 1 forward.

When all the frames of the film 65 have been photographed, as is well known, the motor 15 automatically starts to reverse rotation, and the rewinding claw 69 is rotated via the transmission switching mechanism 20 (the fourth
(see figure). When this rewind claw 69 rotates, the spool 1
The exposed film 65 wound around 5a is rewound into cartridge 70.

In the above embodiment, the second switching lever 13 is switched in conjunction with the first switching lever 12 to insert the conversion lens 6 into the optical axis of the master lens 3. However, the conversion lens 6 may be inserted into the optical axis using other mechanisms.

Furthermore, in the above embodiment, the photographing lens is composed of the master lens 3 that moves in the optical axis direction when switching the focal length, and the conversion lens 6 that is inserted into the optical axis of the master lens 3 during telephoto shooting. The invention also allows the use of zoom lenses.

〔Effect of the invention〕

As explained above, according to the present invention, the rotation of the switching cam that pushes the switching lever for switching the focal length can be controlled by a plurality of stops formed on the cam at unequal intervals in the circumferential direction to stop the rotation of the switching cam. The rotation of the switching cam is stopped by engagement between the switching cams and the stop means that engages with these stop portions to stop the rotation of the switching cam. Therefore, since the intervals between the stop portions are unequal, the rotation of the switching cam at these intervals is such that one rotation is large and the other rotation is small. As a result, since the rotation time and rotation angle between the two are different, it is possible to distribute and selectively use the swinging motions of the various levers commensurate with the rotation time and rotation angle. For this reason, by distributing the swinging of the stopping means consisting of various levers, etc. when the rotation time and rotation angle are larger, it is possible to prevent these levers from swinging at the same time. , the rotational force of the motor can be used efficiently.

Furthermore, for example, among the movements of the master lens in the optical axis direction, a forward movement to extend the master lens to the front of the body is performed by a coil spring that biases the master lens forward, and a switching lever is used to move the master lens backward to retract it into the body. In the case where the rearward movement is performed by pushing, it is necessary to perform the rearward movement against the resilient restoring force of the coil spring. In this case, the rotational force for swinging the switching lever can be increased by bringing the switching lever into contact with the pushing part at a position away from the mounting shaft for backward movement, which requires more rotational force. become able to. Thereby, it is possible to suppress the increase in size of the motor, and it is possible to reduce the size and weight of the entire device.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the main parts of a focal length switching camera according to the present invention. FIG. 2 is a sectional view of the main parts of the focal length switching camera set in a telephoto shooting state. FIG. 3 is a cross-sectional view of the main parts of the focal length switching camera set to a wide shooting state. FIG. 4 is a perspective view showing the TW switching device. FIG. 5 is a plan view of the TW switching device shown in FIG. 4. 6 to 10 are plan views for sequentially explaining the operation of the TW switching device. FIG. 11 is a plan view showing the relationship between the first and second switching levers set in the wide shooting state. Figure 12 shows the first and second cameras set in the telephoto shooting state.
It is a top view which shows a switching lever. FIG. 13 is an external view of the focal length switching camera of the present invention. 1... Moving barrel 3... Master lens 6... Conversion lens 8... Behind shutter 10... TW switching device 11... TW subset slider 12... First switching lever 13...・Second switching lever 14...Switching cam 15...Motor 16...Motor switch 17...Motor switch lever 18...Latch set lever 20...Transmission switching mechanism 23...Rock Dynamic restriction lever 25...Latch lever 26...Transmission lever 27...TW set slider 30...Release pin 46...TW switching knob.

Claims (5)

[Claims] (1) In a focal length switching camera configured to switch the focal length of a photographic lens by transmitting the rotational force of a motor to a focal length switching system, a switching cam arranged in the focal length switching system and rotated by a motor; A plurality of stop parts for stopping the rotation of the switching cam formed at unequal length intervals in the circumferential direction on the switching cam, a stopping means that engages with the stop parts to stop the rotation of the switching cam, and a biasing member on the switching cam. A focal length switching camera comprising a centrally provided pushing part and a switching lever that swings in contact with the pushing part to selectively switch the focal length of a photographic lens. (2) The photographic lens consists of a master lens that moves in the optical axis direction when switching the focal length, and a conversion lens that is inserted into the optical axis of the master lens during telephoto shooting, and these lenses are used for wide-angle shooting and telephoto shooting. 2. The focal length switching camera according to claim 1, wherein the focal length switching camera is configured to be selectively switched between the two positions. (3) The focal length according to claim 2, wherein the switching lever is biased toward the switching cam side by biasing means that biases the master lens toward the telephoto shooting position. Switchable camera. (4) The pushing part of the switching cam and the switching lever are brought into contact on the side near the mounting shaft of the switching lever when switching the master lens from the wide-angle shooting position to the telephoto shooting position,
4. The focal length switching camera according to claim 3, wherein the master lens is brought into contact with the mounting shaft of the switching lever on the far side when switching from the telephoto shooting position to the wide-angle shooting position. (5) The stopping portion is a notch, and the stopping means includes a motor switch lever whose one end is arranged so that it can go in and out within the notch, and a motor switch lever that is turned OFF when the motor switch lever enters the notch. , a motor switch that is turned ON to rotate the motor when the switching cam is pulled out, and a motor switch that is within the rotation range of the pushing part and that is pushed by the pushing part during the rotation of the switching cam and moves to the latched position. A latch set lever, a latch lever that locks the latch set lever when it moves to the latch position, a wide-angle telephoto set lever that unlocks the latch lever when changing the focal length, a latch set lever, and a switch lever. When the latch lever is unlocked, the switch lever is urged to come out of the notch, and when the latch set lever is latched by the latch lever, the switch lever is attached to the switching cam. A focal length switching camera according to any one of claims 1 to 4, characterized in that the camera comprises a spring biased in a direction of entering into the notch.