JPH02304426A - Variable power mechanism for camera - Google Patents

Abstract

PURPOSE:To carry out the switching operation of the moving lens of a finder optical system without increasing the number of parts by preventing a driven side rotary member from being unnecessarily rotated just before and after a prescribed angle rotation when the driven side rotary member is rotated by a prescribed angle. CONSTITUTION:A gear part 1e is engaged with a driving gear 42 based on the driving of a driving side rotary member 1, so that the driven side rotary member 41 is rotated by the prescribed angle and the moving lens is moved to a prescribed position. A cam part 1f which abuts on the driven side rotary member 41 after it is rotated by the prescribed angle or on the driving gear 42 and prevents the driven side rotary member 41 from being reversely rotated is consecutively formed on the gear part 1e of the driving side rotary member 1. Thus, the driven side rotary member 41 can be rotated by the prescribed angle by the driving of the driving side rotary member 1 having a photographing optical system. Consequently, a specific transmission mechanism used to rotate the driven side rotary member 41 being a member for the finder optical system is not required. Thus, without increasing the number of parts, the moving lens of a finder optical system is switched.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a camera having at least two photographic optical systems with different focal lengths, in which a movable lens is inserted into the finder optical system in conjunction with the switching operation of the photographic optical systems. This relates to a camera magnification change mechanism that can be removed from the camera.

BACKGROUND OF THE INVENTION Conventionally, in a camera having at least two photographic optical systems with different focal lengths, a movable lens for the finder in the finder optical system is linked to the switching operation of the photographic optical system (moving operation of the V & shadow lens movable lens). A device equipped with a mechanism for moving is being considered.

In that case, a moving mechanism for the moving lens for the photographing lens and a moving mechanism for the moving lens for the finder are provided, and a transmission mechanism for transmitting the driving force of the driving means to the moving mechanism for the photographing lens, and a mechanism for transmitting the driving force to the moving mechanism for the photographing lens are provided. It also includes another transmission mechanism that transmits transmission to the finder movement mechanism.

Problems to be Solved by the Invention However, the structure described above requires a transmission mechanism for transmitting the driving force to each mechanism, so the structure has the disadvantage that the number of parts increases. there were.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned problems, and to provide a camera magnification changing mechanism that can switch the movable lens of the finder optical system without increasing the number of parts. .

Means for Solving the Problems - In order to achieve the object described in F, the present invention forms a gear part that meshes with a drive gear on the drive side rotating member, so that the drive side rotation member is driven to transmit information through the drive gear. When the driven rotating member is rotated by a predetermined angle, the driven rotating member is prevented from unnecessary rotation before or after the rotating operation by the predetermined angle.

A driven side rotating member drive gear that can mesh with the gear portion of the rotating member, and a moving lens for a finder optical system, and is connected to the drive gear and rotates via the drive gear by rotation of the drive side rotating member. and a driven-side rotating member that is driven, and based on the drive of the driving-side rotating member, the driven-side rotating member is rotated by a predetermined angle by the meshing of the gear portion and the driving gear, and the movable lens is rotated by a predetermined angle. The magnification mechanism of the camera that moves the camera to a predetermined position includes a cam portion that comes into contact with the driven rotating member or the driving gear after the predetermined angle rotation operation and prevents reverse rotation of the driven rotating member. It was configured to be formed continuously with the gear portion of the drive side rotating member.

A driven side rotating member drive gear that can mesh with the gear portion of the member, and a moving lens for a finder optical system, and is connected to the drive gear and is rotationally driven via the drive gear by rotation of the drive side rotating member. and a driven rotating member, and based on the driving of the driving rotating member, the driven rotating member is rotated by a predetermined angle due to the meshing of the gear portion and the driving gear, and the movable lens is rotated to a predetermined angle. By using the variable magnification mechanism of the camera to move it to the desired position,
A cam part that comes into contact with the driven rotating member or the driving gear before the predetermined angle rotation operation and prevents rotation of the driven rotating member is formed continuously with the gear part of the driving rotating member. It was configured as follows.

In each of the above configurations, the drive gear has a rotation center that is the same as a rotation center of the driven rotation member, and is connected to the driven rotation member by a spring member, while the rotation center of the drive gear is the same as the rotation center of the driven rotation member. The rotation angle is smaller than the rotation angle of the driven rotating member, and after the driving gear has rotated by a predetermined angle, the driven rotating member charges the spring member to position the driving gear and rotate the driven gear. It is also possible to form an upright wall section on the cam section of the drive-side rotation member to hold the overcharge of the drive-side rotation member.

According to each of the above configurations, it is possible to rotate the driven-side rotating member having the finder optical system movable lens by a predetermined angle by driving the driving-side rotating member having the photographing optical system. Since there is no need for a special transmission mechanism to rotate the member for the finder optical system (driven rotating member), the moving lens of the finder optical system can be switched without increasing the number of parts. I can do it.

Further, according to the configuration of the variable magnification mechanism of the first camera, based on the drive of the driving side rotating member, the driven side rotating member is rotated by a predetermined μm degree due to the meshing of the gear portion and the driving gear. After the movable lens is moved to a predetermined position, the cam portion of the driving side rotating member comes into contact with the driven side rotating member or the driving gear, so that the reverse rotation of the driven side rotating member is effected. can be prevented. Therefore, the movable lens for the finder optical system can be reliably moved to a predetermined position and can be reliably held at that position.

Moreover, since the operating amount of the driven rotating member is determined by the fraction of the drive gear, there is no need to correlate it with the operating amount of the driving rotating member or to provide a separate speed increasing mechanism. Further, since the cam portion of the drive-side rotation member effectively prevents the driven-side rotation member from rotating in reverse, even if the rotation drive operation between the drive-side rotation member and the driven-side rotation member is repeatedly performed. The meshing between the drive gear that drives the driven rotation member and the gear portion of the drive rotation member is less likely to be misaligned.

Further, according to the variable magnification mechanism of the second camera, based on the drive of the driving side rotating member, the driven side rotating member is rotated by a predetermined angle due to the meshing of the gear portion and the driving gear, and the driven side rotating member is rotated by a predetermined angle. Before the movable lens is moved to a predetermined position, the cam portion of the drive-side rotation member comes into contact with the driven-side rotation member or the drive gear, thereby causing the driven-side rotation member to rotate in the rotation direction. can be effectively prevented. Therefore, when rotating the finder optical system movable lens to a predetermined position,
It is possible to effectively prevent the driven-side rotating member from starting rotation before rotational driving, and the rotation of the driven-side rotating member, that is, the movement of the movable lens, can be performed more reliably. Further, since the cam portion of the drive-side rotation member effectively prevents the rotation of the driven-side rotation member during a predetermined angle rotation movement song, the rotation movement of the drive-side rotation member and the driven-side rotation member is repeated. Even if this is done, the meshing between the drive gear that drives the driven rotating member and the gear portion of the driving rotating member is unlikely to be misaligned.

Embodiments of the present invention will be described in detail below with reference to FIGS. 1-11.

An electronic still camera equipped with a camera magnification change mechanism according to this embodiment will be described.

FIGS. 1(a) to 1(e) show external views of an electronic still camera which is an embodiment of the present invention. As shown in FIG. 1(c), the front of the camera includes a flash 70, a photometer 80, a part of the viewfinder 40, and a lens barrier 58 in normal conditions.
The visible lens aperture is located. Figure 1 (
As shown in b), a release switch 5, a telephoto switch 3 for changing lenses, and a close-up switch 4 are arranged on the top surface of the camera. Further, as shown in FIG. 1(a), a main switch 90 for turning the power on or off is arranged on the rear surface of the camera. Inside the camera, an image sensor 25 is arranged behind the lens barrier 58 via a photographing lens system, and the image taken by the image sensor 25 is subjected to image processing, and then transferred to a floppy disk set in the camera by a deck section 80. recorded on the disc.

FIG. 1(f) shows a system diagram of the camera of this embodiment. Note that in this figure, a lens barrier drive unit and a lens rear block 2i1a, which will be described later, are omitted for brevity.

The photographic lens system of this embodiment has two main optical systems A (Ia).
, B (Ib), and the position of the main optical system B (I b) on the image sensor 25 side when the main optical system B (I b) is in the photographing optical path (optical path center X). and a rear lens block 2 that holds a sub-optical system C (2c) that is inserted into and removed from the lens.

These two blocks 1.2 are 90° to the lens rotation axis 22.
It is rotatably supported within the range of 1.2
Tomo snap spring 6. +7 makes Oo or 9
It is pressed and fixed at the 0° position.

As shown in Table 1, the photographic optical system of this embodiment can be used as three different types of photographic lenses depending on the positions of the front lens block 1 and the rear lens block 2. Figure 2 is a model representation of the photographic optical system in each state.
FIG. 2(a) shows the state of the wide-angle lens, FIG. 2(b) shows the state of the telephoto lens, and FIG. 2(c) shows the state of the close-up lens.

Table 1 In this example, the photographing lens has a fixed focus in each of the three states, the wide-angle lens is 9/F3.5, the telephoto lens is f20/F3.5, and the close-up lens is f2.
0/F l 6. The reason why the F number of close-up lenses is increased is to widen the depth of field, and because the possible shooting distance (focusing distance) is close, the flash is used when the light is insufficient. I try to take pictures by letting the camera move. FIG. 3 shows the distance that can be photographed with each lens and the screen ratio when photographing a person.

In this embodiment, since the taking lens is in a standard state as a wide-angle lens, two operating members, a telephoto switch 3 and a close-up switch 4, are provided as operating members for changing the magnification. When these operating switches are operated, the photographing lens is switched from the wide-angle lens state to each state, and when the operation of the operating switches 3.4 is stopped, the wide-angle lens state is returned again.

Further, when the photographing lens is a telephoto lens or a close-up lens and the release switch 5 is turned on to take a picture, the lens automatically returns to the wide-angle lens state after exposure is completed.

Further, a lens barrier 58 (see FIG. 6), which will be described later, opens when the release switch 5 is turned on to prevent burn-in of the image sensor 25, and closes after exposure is completed.

That is, in this embodiment, an image sensor that can control the start and end of charge accumulation is used as the imaging element 25, and by changing the accumulation time without using a light amount adjustment means such as an aperture, proper exposure can be achieved. It does not have an aperture because it can be adjusted. For that reason, Lens Barrier 5
If the lens barrier 8 is open all the time, image capture will occur in the image sensor 25 when strong external light is incident, so the lens barrier 58 is opened only during exposure.

Now, the switching operation from the wide-angle lens state to the telephoto lens state will be explained (see FIG. 1 ( ) and FIG. 4).The step numbers in the text are the step numbers in the flowchart of FIG. 1+. As shown in FIG. 11(a), when the photographer turns on the telephoto switch 3 (step S I Ol), the camera microcomputer 6 starts the motor 7 to rotate forward (step S 102). A worm gear 7a is attached to the motor 7 in the example and the figure, and the direction in which the reduction gear 8, which is a worm wheel, is rotated in the direction of the arrow in the figure is the normal rotation of the motor 7, and the opposite direction is the reverse rotation of the motor 7. I will express it as

In addition, for gear trains and rotating bodies other than the motor 7, clockwise rotation represents a forward direction, and counterclockwise rotation represents a reverse direction. When the motor 7 rotates forward in step 5102, the sun gear 9 rotates in the forward direction via the reduction gear 8. When the sun gear 9 rotates in the forward direction, the planetary gear ``0'' meshes with the manual gear lla of the lens switching gear All, which is a four-speed gear, and transmits rotation, so that the lens switching gear All rotates in the forward direction. The lens switching gear All is provided with a lens state detecting means 12, and signals representing three states are outputted from the lens state detecting means 12 during one rotation of the lens switching gear A11.

FIG. 5(a) shows a pattern diagram of a patterned substrate 12a which is one element of the lens state detection means 12 of this embodiment. The lens state detection means 12 detects pattern 1 (12-1) and pattern 2 (12-1) by sliding a section 12b fixed to the lens switching gear All on the pattern board 12a.
2) and the GND line (12-0) to obtain a signal. Taking the rotation angle of the lens state detection means 12 as the horizontal axis, the time when it is electrically connected to the GND line (12-0) is the time when the signal is not electrically electrically connected! Figure 5 (b
), and the relationship between each lens pattern and each lens state is summarized in Table 2.

As can be seen from Table 2, Figure 5(b), the status signals of the wide-angle lens, telephoto lens, and close-up lens are output approximately every 120° (three equal parts of one rotation), and each status signal is output. Since the sections where the lens is in each state are narrower than the sections where the lens is in each state, the photographing lens is always in that state when each state signal is output.

In the close-a-plane lens state, as shown in FIG. 5(b), the section where lens pattern 2 (12-2) becomes Lo is widened. This is related to the operation of returning to the wide-angle lens state in the lens switching operation, which will be described later, but will be briefly explained here first. If the lens pattern l(+2-1
) and lens pattern 2 (12-2) are set to be exactly the same, the lens pattern board! 2a and section 1
2b, a pattern error on the pattern board 12a, an error in the intercept 12b, etc., the signal indicating the state of the wide-angle lens, that is, the lens pattern 1 (12-1) is L.
o signal and lens pattern 2 (12-2) may produce an l-1i signal, which may lead to malfunction, so the telephoto lens state that does not lead to malfunction is shown on both sides of the section where the close-up lens status signal is output. There is a section where signals are issued.

Furthermore, the reason why the pattern for outputting each status signal is varied is that it takes a certain amount of time from when the signal is output from the lens status detection means 12 until the motor 7 stops, and also when the motor 7 stops, the lens This is to ensure that the same status signal is output from the status detection means.

The lens switching operation will be described below with reference to FIG. Figure 4 (b), (d), (f), (h), (j), (1)
are the movements of the front lens block l, respectively, and Fig. 4 (c
), (e), (g), (i), (k), and (m) indicate the operations of the rear lens block 2, respectively. The forward rotation of the motor 7 as described above causes the lens switching gear All to rotate in the forward direction, and when the lens state detection means 12 outputs a telephoto signal to the camera microcomputer 6 (steps 5103 and 5I04), the camera microcomputer 6 7 stops (step 5
lO5). At this time, the segment 12b stops at a point of about 120'' on the lens pattern board 12a, indicating the telephoto lens state.The lens switching gear All and the lens switching gear C14 are both partially toothed gears, and are used for wide-angle lenses. Although the gears are not connected in the state (FIGS. 4(b) and 4(c)), when the lens switching gear A2 starts rotating, the gear portion zb meshes with the gear portion 14c, and the lens switching gear A
ll and the lens switching gear CI4 begin (FIGS. 4(d) and (e)), and both gear portions 11b and +4c are disengaged before the motor 7 stops. Here, the lens switching gear Al, which is a 4-stage gear, transmits meshing rotation from the lens switching gear All to the lens switching gear C14.
(See FIG. 4(a))
. When the lens switching gear CI4 rotates, this gear C
The front lens block 1 rotates around the lens rotation axis 22 due to the meshing between the first gear part 14a of the lens front block 14 and the gear part 1d of the front lens block l. A biasing force is applied to this lens front block l by a snap spring A16, but the lens switching gear All and the lens switching gear C14
When disengaged from the lens, the front lens block l has rotated to such an extent that the direction of the biasing force is reversed. Therefore, the snap spring A16 allows the lens positioning B24 of the block l to the lens front block l.
An urging force acts to suppress and fix the situation. Therefore, the photographing lens is switched to the telephoto lens state, and the lens switching gear C14, which is always connected to the front lens block 1 through the gear parts 1d and 14a, is also shown in FIGS. 4(r) and 4(g). It is fixed in such a position that it can be Further, both the lens switching gear CI4 and the lens switching gear Bla are connected to the second gear portion 14b.
are always connected in gear via the first gear portion 13a and fixed at the positions shown in FIGS. 4(r) and 4(g).

Next, the switching operation from the wide-angle lens state to the close-up lens state will be described. When the photographer turns on the close-up switch 4 (step 5201)
, the camera microcomputer 6 starts the motor 7 to rotate in the normal direction, similar to the switching operation to the telephoto lens state (step 520).
2). Then, similarly to the switching operation from the wide-angle lens state to the close-up lens state, the lens switching gear Al
l rotates in the forward direction. In this case, the motor 7 continues to rotate until the close-up signal is output from the lens state detection means 12. That is, the patterned substrate 12
The above rotation is continued until the section 12b slides on the section a and stops at a position of about 240 degrees.

Similar to the switching operation from the wide-angle lens state to the telephoto lens state, until the telephoto signal is output from the lens state detection means 12, only the front lens block I is rotated, and the main optical system of the photographing lens is rotated. is the main optical system B (l b
). After that, during the rotation until the close-up signal is output, the second output gear portion 11c of the lens switching gear All and the lens switching gear C as shown in FIGS. 4(h) and 4(i).

15, the first gear part 15a and gear part 2d of lens switching gear +C'15 are engaged with the second gear part 15b of
The lens rear block 2, which is gear-coupled with the lens rear block 2, is rotated by the rotation of the lens switching gear C15. When the gears 15a and 2d are disengaged, the rear lens block 2 is pressed and fixed to the lens positioning B24 by the snap spring B17, as shown in FIG. 4(j).
The state shown in (k), that is, the rear lens block 2
is switched to the 90° position. A short time after the gears 15a and 2d are disengaged,
A close-up signal is output from the lens state detection means 12 (steps 5203 and 5204), and the motor 7 is stopped (step S205). By the above operation, the rear lens block 2 is switched to the 90° position, and the sub optical system C (2c) is placed on the image sensor side of the main optical system B (1b).
is inserted, and the switching operation to the close-up lens state is completed.

The following describes the operation when the photographer stops (turns off) the operation of the telephoto switch 3 after switching the photographing lens to the telephoto lens state. In other words, the photographer presses the telephoto switch 3.
When the operation is stopped (step 9106), the camera microcomputer 6 causes the motor 7 to start rotating in the normal direction (step S1).
07), the rotation continues until a wide-angle signal is output from the lens state detection means 12. Because of this operation, it is necessary to devise a pattern in the close-up lens state of the lens state detection means 12 described above. When the motor 7 continues to rotate, the lens switching gear All rotates in the forward direction from the 120° position to the 360° (0°) position. After passing through the state in which the photographing lens is switched to the close-up lens state (Fig. 4 (j), (k)) by the meshing operation of both gear parts 11c and 15b, the state shown in Fig. 4 (1), ( m) lens switching gear A(l
l) Third output gear section 11d and lens switching gear 81
Due to the meshing of the second gear portion 13b of No. 3, the lens switching gear B13 rotates in the opposite direction. Therefore, since the lens switching gear C14, which is always gear-coupled with the lens switching gear B13 via the gear parts +3a and I4b, is rotated in the forward direction, the gear part 14a of the lens switching gear C14 and the gear of the lens front block I are rotated in the forward direction. Through engagement with the portion 1d, the lens front block l rotates in the opposite direction of the switching operation from the wide-angle lens to the telephoto lens. Here again, both the gear parts 11d of the lens switching gear Att and the lens switching gear B13,
13b, the lens front block l is moved to the lens positioning A23 by the snap spring A16.
By being suppressed and fixed, the position is fixed and the lens returns to the state of a wide-angle lens. At this time, a wide-angle signal is output from the lens state detection means 12 (step 5).
108.5109), the motor 7 is in a stopped state (
Step 5IIO).

According to the above explanation, the rotational force from the motor 7 is applied to both the gear parts 11 of the lens switching gear All and the lens switching gear B13.
d, the lens front block l due to the meshing action of 13b.
However, in this example,
The front lens block 1 and the rear lens block 2 are configured in such a shape that when the front lens block 1 returns from the position in the close-up lens state to the position in the wide-angle lens state, it returns while pushing the rear lens block 2. Therefore, the rear lens block 2 is also returned to the wide-angle lens state,
Lens positioning A2 by snap spring B17
3 and becomes the wide-angle lens state shown in FIGS. 4(b) and 4(c). That is, as shown in FIG. 1O, the rear lens block 2 has a standing wall 2Q, and the standing wall 2
Q overlaps the cylindrical portion 1 of the front lens block 1 in the front-back direction. Therefore, as the front lens block l moves from FIG. 4 (D) to FIG. 4 (12) and FIG. Figure 4(k) to Figure 4(,m
), it moves to Fig. 4(c).

Next, an explanation will be given of the operation when the photographer cancels (turns off) the operation of the close-up switch 4 after switching the photographic lens to the close-up lens state. When the photographer stops operating the close-up switch 4 (step 5)
206), similarly to when the operation of the telephoto switch 3 is stopped in the telephoto lens state, the motor 7 is a lens state detection means! The normal rotation continues until the wide-angle signal is output from 2 (step 5207). In this case, the third output gear lid of the lens switching gear All and the lens switching gear B are connected in the same way as when the operation of the telephoto switch 4 is stopped in the telephoto lens state.
13, the lens front block l and the lens rear block 2 are moved as shown in FIG. 4(b).
After returning to the wide-angle lens state as shown in (c) and outputting a wide-angle signal (steps 8208 and 5209), the motor 7 is stopped (step 5210).

The lens switching operation has been explained above, and the lens switching operation of this embodiment is characterized by a unidirectional loop of wide-angle lens → telephoto lens → close-up lens → wide-angle lens. Lens switching is performed by rotation in only one direction.

Next, the operation when photographing will be described below.

First, the photographer presses the release switch 5 while using the wide-angle lens.
The case where the switch is turned on will be explained based on FIG. 11(c).

When the photographer turns on the release switch 5 (step 5)
301), a signal is input to the camera microcomputer 6, and the camera microcomputer 6 causes the motor 7 to rotate in the opposite direction to that during the lens switching operation (step 53028 and subsequent steps are referred to as reverse rotation). Then, the sun gear 9 rotates in the opposite direction via the reduction gear 8, and the planetary gear 10 moves away from the lens switching gear All and meshes with the barrier drive gear 51. Therefore, rotation is transmitted from the planetary gear 10 to the barrier drive gear 51,
Barrier drive gear 51 rotates in the opposite direction. The barrier drive gear 51 is provided with barrier state detection means 52,
By outputting a barrier open signal to the camera microcomputer 6 at the position of the barrier drive gear 5I corresponding to the barrier open position (
Step 5303), to stop the motor 7
04), the system starts charge accumulation in the photographing element 25 by generating a barrier open signal (step 5305). After the charge accumulation is completed, the camera microcomputer 6 starts the motor 7 to reverse rotation again (step 8306), the barrier drive gear 51 also rotates in the opposite direction, and the barrier drive gear 51 corresponding to the barrier closed position is detected by the barrier position detection means 52. A barrier close signal is output at the position (step 5307)
This causes the motor 7 to stop (step 530B).

Hereinafter, the operation of the lens barrier will be briefly explained based on FIG. 6. FIG. 6(a) shows the barrier open state, and FIG. 6(b) shows the barrier open state. When the barrier drive gear 51 is in the state shown in FIG. 6(a), the barrier close signal is output from the barrier state detection means 52, and the barrier drive gear 51h is in the state shown in FIG. 6(b). At this time, the barrier open signal is output from the barrier state detection means 52.Here, as shown in Table 3 below, the barrier open signal is when the barrier pattern Ih<Lo and the barrier pattern 2 is Hi. Further, the barrier close signal means that barrier pattern 1 is Hi and barrier pattern 2 is Lo.

Table 3 First, the crank mechanism that opens and closes the barrier will be explained.

The lens barrier 58 is interposed between each lens and the image sensor 25 and acts as a barrier guide between a barrier closed position where it blocks light rays entering the image sensor 25 from the lens and a barrier open position where it is retracted from between both members. Move according to the guidance of 59. That is, the protrusion 5 at the lower end of the lens barrier 58 in FIG.
8a moves within the groove of the barrier guide 59,
The lens barrier 58 smoothly moves between the two positions. This lens barrier 58 is always urged toward the barrier closed position by a barrier spring B56. That is, Fig. 6 (g
), the barrier spring B56 is actually a torsion coil spring, and after being charged in the direction of the arrow in FIG. , the other end 56b is locked to the fixed part.

One end 57d of a barrier drive lever B57 is pivotally attached to the upper end of the lens barrier 58 in FIG. As shown in FIG. 6(e), the other end 57c of this barrier drive lever B57
is pivotally attached to the base end portion 54c of the substantially fan-shaped barrier drive connecting plate 54, and has a protrusion 57a on the lower surface of the intermediate portion thereof. The barrier drive connecting plate 54 is provided with a concave groove 54a extending in an arc toward the barrier drive lever side on its surface, and the barrier drive lever B57 is movable along the concave groove 54a within the concave groove 54a. The protrusion 57a is fitted. A barrier drive lever A is provided on the back side of the barrier drive connection plate 54.
One end of 53 is the pivot pin 5 on the lower surface of the barrier drive connecting plate 54.
4d, while the barrier drive lever A53
The other end is connected to the barrier drive gear 51 by means of a pivot pin 51a.
is pivotally mounted on the top surface of the In addition, as shown in FIG. 6 ( ), the barrier drive lever B57 and the barrier drive connection plate 54
The winding part of the barrier spring A55 is fitted concentrically with the pivot shaft of the barrier spring A55, and after being charged as shown by the arrow in FIG.
4b and the protrusion 57a of the barrier drive lever B57.

When the release switch 5 is turned on, the motor 7 starts to rotate in reverse (step 5301), and the barrier drive gear 51 is rotated in the opposite direction (step 5302), the barrier drive gear 51, barrier drive lever A53, barrier drive connection plate 54
A crank mechanism between the two rotates the barrier drive connecting plate 54 in the opposite direction. Then, since the projections 57a and 54b are sandwiched between both ends 55a and 55b of the barrier spring A55, the barrier drive lever B57 also rotates in the same manner as the barrier drive connection plate 54, so that the lens barrier 58 is regulated by the barrier guide 59. 6(a) to 6(b), and a barrier open signal is output from the barrier state detection means 52 to the camera microcomputer 6, and the motor 7 is stopped. (Step 530
4). Further, by outputting this barrier open signal to the camera microcomputer 6, charge accumulation in the image sensor 25 is started (step 5305).

The time from the start to the end of charge accumulation is determined by the result of photometry by the photometer 80, and the camera microcomputer 6 controls the image sensor 25.

When the charge accumulation of the image sensor 25 is completed, the motor 7 starts to rotate in reverse direction again by the camera microcomputer 6 (step 53Q6).
), the barrier drive gear 51 also rotates in the opposite direction again. Here again, the barrier drive gear 51, the barrier drive lever A
53, the barrier drive connection plate 54 is rotated in the forward direction by a crank mechanism between the barrier drive connection plate 54. Then, the barrier drive lever B57 is also rotated by the barrier spring A55 in the same way as the barrier drive connection plate 54, so the lens barrier 58 moves in the closing direction while being regulated by the barrier guide 59, and from FIG. 6(b) to FIG. When the barrier closes as shown in (a) and the barrier close signal is output by the barrier state detection means 52 (step 5307), the motor 7 is stopped by the camera microcomputer 6 (step 8308).
). .

When a force is applied from outside to open the lens barrier 58 while the lens barrier is closed, such as when a photographer tries to forcefully open the lens by hand, the operation is as shown in FIG. 6(c). There are two cases: a case where the barrier drive gear 51 and the planetary gear 10 are engaged, and a case where the barrier drive gear 51 and the planetary gear 10 are not engaged as shown in FIG. 6(d).

First, as shown in FIG. 6(c), when the barrier drive gear 51 is meshed with the planetary gear IO, the gear connection is connected to the motor 7, so the barrier drive gear 5I does not rotate. The barrier drive lever A53 and the barrier drive connection plate 54 also remain fixed. lens barrier 5
8 is opened by an external force, the position of the barrier drive lever B57 also changes due to the movement of the lens barrier 58. As a result, the barrier drive connection plate 54 and the barrier drive connection plate <-B
57 changes, barrier spring A5
5, the two are spring-coupled to prevent breakage. In this state, the barrier spring A55 whose ends are locked to the pivot pin 54d and the protrusion 57a is charged. Therefore, when the external force is removed, the lens drive lever B57 is returned to the closed position by the biasing forces of the barrier spring A55 and barrier spring B56.
The lens barrier 58 is also returned to the closed state.

On the other hand, when the barrier drive gear 51 and the planetary gear 12 are not engaged, as shown in FIG. ) rear drive connecting plate 54,
The positions of the barrier drive lever 33 and the barrier drive gear 51 also change. Since the barrier spring 856 is charged by this external force, when the external force disappears, the biasing force of the barrier spring B56 causes the lens drive lever B57 to
is returned to the closed position, thereby causing the rear 58
Also, the barrier drive connecting plate 54, the barrier drive lever A53, and the barrier drive gear 5 are in the closed state! is also returned to the closed state.

The above operation is performed when the photographer turns on the release switch 5 with a wide-angle lens, but when the photographer turns on the release switch 5 with a telephoto lens, the operation is as follows. That is, when the release switch 5 is turned on (step 5301), the camera microcomputer 6 reverses the motor 7 (step 5302), opens the lens barrier 58 (step 5303), and after the end of exposure, the camera microcomputer 6 reverses the motor 7 again. The operation up to closing the lens barrier 58 is exactly the same as when the release switch 5 is turned on in the wide-angle lens state (steps 8304 to 830B). At the time when the barrier state detection means 52 inputs the barrier close signal to the camera microcomputer 6, the signal from the lens state detection means 2 is a telephoto signal (step S309), so the camera microcomputer 6 controls the motor 7. Start normal rotation (step S31.1).

The operations from this point on are similar to those in the case where the photographer stops operating the telephoto switch in the telephoto lens state described above, and the photographing lens returns to the wide-angle lens state.

Furthermore, when the photographer turns on the release switch 5 while using a close-up lens, turning on the release switch 5 (step 5301) causes the camera microcomputer 6 to reversely operate the motor 7 (step 5302), and the lens barrier 58 (step S303), and after the exposure is completed, the camera microcomputer 6 reverses the motor 7 again (steps 8304 to 8306), and the operation until the lens barrier 58 is closed (steps 5307 and 9308) is to release the camera in the wide-angle lens state. This is exactly the same as when switch 5 is turned on. The camera microcomputer 6 is detected by the barrier state detection means 52.
At the time when the barrier close signal is input, the signal from the lens state detection means 52 is a close-up signal (steps 5309, 5310), so the camera microcomputer 6 starts the motor 7 to rotate normally (step 5311). The operations from this point on are similar to those performed when the photographer cancels the operation of the close-up switch while in the close-up lens state described above, and the photographing lens returns to the wide-angle lens state.

The operation of the lens barrier and photographic lens during photographing has been described above. However, at the time when the barrier state detection means 52 outputs the barrier close signal, the lens state detection means 12 outputs a signal other than the wide-angle signal (telephoto signal, close-up signal, close-up signal, etc.). signal, switching signal) is output (steps 9309, 531
0), the motor 7 is rotated forward by the camera microcomputer 6 (step S311), and the photographing lens is rotated by the lens state detection means 1.
2 until the wide-angle signal is output (steps 5312 to 5314).

Above, in the mechanism for performing each operation, the lens switching operation by the meshing of the partially toothed gears 1101 and 11102 as shown in FIG. 7(a) has been described.
If 01 and 102 have a tooth shape like that shown in Figure 7(a), the first tooth to collide with the other gear will be subject to an impact force, so it will need to be strong. It's coming.

Therefore, as shown in FIG. 7(b), each gear 101, 102
It is safer to fill it with meat.

That is, a built-up portion 101a as shown by diagonal lines is formed between the first tooth totb and the second tooth [01c] of the 111th Olb of the drive side gear riot.

On the other hand, the built-up portion 101 of the driven gear ■102
A notch 102d corresponding to the built-up portion 101a is formed at the tip of the second tooth 102c of the driven gear (2) 102 corresponding to a. Therefore, when both gears 101 and 102 mesh, the above-mentioned notch 102d
and the built-up portion 101a engage so that they face each other,
No equivalent load is applied to the mesh, and the drive side gear 1101
The first tooth 101b is the second tooth 1 of the driven gear 11102.
It can be easily engaged with 02c. In addition, on the side opposite to the second tooth 102c of the first tooth 102b of the driving force side gear ■102 in FIG. Filled portion 102a
It is also possible to form

This portion does not mesh with the first tooth 101b of the drive side gear 1101. In this way, the built-up parts 101a, 1
By forming 02a on each gear 101, 102,
Drive side gear N011 where impact force is applied Drive side gear ■10
It becomes possible to provide sufficient strength to each of the first teeth 101b and 102b.

Next, a viewfinder switching operation that is performed simultaneously with the lens switching operation described above will be explained. The finder optical system is in its standard state when the photographing lens is a telephoto lens, and when the photographing optical system is a wide-angle lens, a wide-angle lens sub-optical system block 41 is placed on the subject side of the finder main optical system. Further, when the photographing optical system is used for close-up, a wedge lens block 45 is inserted on the subject side of the finder main optical system to reduce vararax. The operation will be explained below.

FIGS. 8(a) to 8(r) are diagrams showing the viewfinder switching operation in three states of the photographic lens, and FIG.
a) and (b) are the states of the wide-angle lens, Figure 8 (c)
, (d) is the state of the telephoto lens, Fig. 8 (e), (f)
indicates the state of the close-up lens. For the sake of simplification, FIGS. 8(a), (c), and (e) show the operation of the lens front block 1 and the wide-angle lens sub-optical system block 41, and FIGS. 8(b), (d), (f) shows the operation of the rear block 2 and the wedge lens block 45. FIGS. 8(g) to 8(i) show a mechanism for performing the above switching operation. In the figure, the wide-angle lens sub-optical system block 4
The cylindrical part 41a of 1 has a wedge lens block 45 on the same axis.
The cylindrical portion 45a of the wide-angle con gear 42, and the cylindrical portion 46a of the wedge gear 46 are pivotally connected. The wide-angle con spring 43 and wedge spring 47 are
It is arranged between the wide-angle lens sub-optical system block 41 and the wedge lens block 45. As shown in FIG. 8(h), the wide-angle con spring 43 has its winding portion fitted into the cylindrical portion 41a of the wide-angle con sub-optical system block 41, and both ends 43a and 43b are charged in the direction of the arrow. The projection 41b of the wide-angle con sub-optical system block 41 and the protrusion 42a of the wide-angle con gear 42 are sandwiched therebetween. In addition, the wedge spring 47 is shown in FIG.
As shown in i), the winding part is fitted into the cylindrical part 45a of the wedge lens block 45, and both ends 47a, 4
7b is charged in the direction of the arrow, and the protrusion 45b of the wedge lens block 45 and the protrusion 46a of the wedge gear 46 are sandwiched therebetween.

First, the operation of the wide-angle lens sub-optical system block 41 will be explained. When the front lens block l is in the position shown in FIG. 8(a), the gear part 1e of the front lens block 1 and the wide-angle con gear 42 are engaged, and the wide-angle con sub-optical system block 41 and the wide-angle con gear 42 are engaged with each other. Since the gap is spring-connected by a wide-angle con spring 43, when the wide-angle con spring 43 is charged, the con sub-optical system 41 is pressed against the wide-angle con stopper A (44a) and is kept constant.

When the front lens block l rotates in this state, the front lens block! Since the gear part 1e and the wide-angle con gear 42 are initially engaged, the wide-angle con gear 42 rotates, but the front block of the lens! When the last tooth of the gear part 1e finishes meshing, the last gear of the wide-angle con gear 42 maintains its rotated position without moving backwards by sliding along the cam part 1 of the front lens block l. Figure 8 (c
) and (e), the front lens block l is pressed by the claw portion 1h, which presses one end of the wide-angle con gear 42, charging the wide-angle con spring 43, and the wide-angle con spring 43 is charged. The condenser sub-optical system block 41 is pressed and fixed to the wide-angle condenser stopper B (44b), and is retracted out of the finder optical path (optical path center Y).

Next, the operation of the wedge lens block 45 will be explained. When the rear lens block 2 is in the position shown in FIGS. 8(b) and 8(d), the same condition as in the state of the wide-angle lens sub-optical system block 41 shown in FIGS. 8(c) and 8(e) is performed. In the mechanism, one end of the wedge gear 46 is suppressed by the pressing pawl 2h of the rear lens block 2, thereby charging the wedge spring 47 and pushing the wedge lens block 4.
5 is press-fixed to the wedge stopper B (48b) and retracted out of the finder optical path. Then, when the rear lens block 2 rotates, the first tooth of the wedge gear 46 is
It slides along the cam portion 2'' of the rear lens block 2, and meshing starts from the first tooth of the gear portion 2e of the rear lens block 2, and the last tooth of the wedge gear 46 slides along the cam portion 2'' of the rear lens block 2.
While engaged with the gear portion 2e, the wedge lens block 45 is pressed against the wedge stopper A (48a) by the charge of the wedge spring 47, and inserted into the finder optical path for positioning.

In this example, a wedge lens is used to correct vararax in the close-up lens condition.
A similar effect can be obtained by inserting another field frame into the finder optical path instead of the wedge lens.

With only the lens switching mechanism as explained above, in each state of wide-angle lens, telephoto lens, and close-up lens, lens switching gear All and lens switching gear B1
Since there is no gear connection between the front lens block I and the rear lens block 2, the positions of the front lens block I and the rear lens block 2 are maintained only by the pressing force of snap spring AI6 and snap spring B17, respectively, and there is no impact load etc. on the camera. It is conceivable that if this happens, it will switch to another state.

Therefore, in this embodiment, in order to prevent switching of the photographic lens due to external force, the switching prevention claw A1B shown in FIG.
and a switching prevention claw B20. The operation of this switching prevention pawl A18 will be described below as an example.

The switching prevention pawl A18 is rotatably supported on the rotating shaft A (18a) as shown in FIG.
), as shown in (b), the block in front of the lens! The rear lens block 2 is maintained in a retracted position where it cannot be prevented from rotating. Note that the rear lens block 2 is not shown for simplicity.

When at least one of the front lens block l and the rear lens block 2 is at the 0° position, that is, when it is a wide-angle lens or a telephoto lens, an external force that rotates the front lens block l and the rear lens block 2 in the forward direction. If the inertial force of
As shown in figure (a), the straight line ZI connecting the center of gravity of the switching prevention claw A18 and the rotation axis A (18a) and the lens front block 1 are O.

Since the weight balance is adjusted so that the straight line Z connecting the center of gravity 1g and the lens rotation axis 22 when in the position is approximately parallel, there is an inertia force that causes the switching prevention claw AI8 to rotate in the forward direction. act. The above switching prevention spring A19
The amount of pressing force of the switching prevention pawl AI8, the amount of pressing force of the front lens block 1 due to the snap spring A16, and the amount of pressing force of the rear lens block 2 due to the snap spring B17 are as follows: Since the weight ratio is set almost equal to the weight ratio, when an inertial force that causes the front lens block l and the rear lens block 2 to start rotating is applied, the switching prevention claw A1B also rotates, and the switching prevention claw A! 8. The claws 1i, 2, i (Fig.
(see b)), both lens blocks 1
．． 2 can be prevented from rotating (see FIG. 9(c)).

This inertial force is instantaneous, and when this inertial force disappears, the switching prevention claw A18, the lens front block 1, and the lens rear block 2 are activated by the switching prevention spring A19, the snap spring A16, and the snap spring B17.
is returned to its normal position (see FIG. 9(a)).

The switching prevention claw B20 shown in FIG. 9(e) has the same settings as the lens front block l lens rear block 2, the center of gravity, the rotation axis position, and the force of the spring as the switching prevention claw AI8. , operates in the same way as the switching prevention claw AlB (
FIG. 9(b),(d)). In addition, in the figure, Z is a straight line connecting the center of gravity of the switching prevention claw B20 and the rotating shaft 20a, and 1
j, 2 j (see Figure 8(b)) is the switching prevention claw B2
Furthermore, in this embodiment, an inertial force is applied due to an external force during lens switching operation, and the switching prevention claw A is caught.
1B and switching prevention claw B20 lock the lens front block l lens rear block 2, the motor 7
Since it is conceivable that the motor and the gear train may be destroyed if the motor continues to rotate, a sliding mechanism is provided at the reduction gear 8 to prevent the gear train from being destroyed.

Furthermore, in this embodiment, the photographing lens system is divided into a front lens block and a rear lens block 2, each of which operates independently, so that there is a risk of stray light entering the photographing optical path. For this reason, as shown in Figure 1O, there is a block in front of the lens! A stray light prevention wall protruding in an arc shape is provided on the rear lens block 2 to block stray light. That is, the surface H of the front lens block l facing the rear lens block 2, (
(See FIG. 4(a)), a first annular optical system surrounding the main optical system 1a is shown.
A stray light prevention wall 1k is formed to protrude along the front-rear direction, and the first stray light prevention wall 1 protects the rear lens block 2.
Two second stray light prevention walls 1(!, 1a+) extending in an arc shape around the rotational axis of the second stray light prevention wall 1(!, 1a+) are formed to protrude along the front-rear direction.

In addition, a third stray light prevention wall 2k in an annular shape surrounding the sub optical system 2C is formed on the rear lens block 2 facing the front lens block l (see FIG. 4(a)) so as to protrude along the front-rear direction. At the same time, the third stray light preventing wall 2 extends and the two second stray light preventing walls 117. A fourth stray light prevention wall 2g that always closes the space between Is is formed to protrude along the front-rear direction. By providing such a stray light prevention wall, even when the sub optical system 2c is retracted from the imaging surface side of the main optical system 13 etc. due to the rotation of the lens rear block 2,
The fourth stray light prevention wall 2Q is the second stray light prevention wall 112.
Since the space between Ira and Ira is closed, it is possible to effectively prevent stray light from entering the camera. Therefore, a wide-angle lens (Fig. 110(a)) and a telephoto lens (Fig. 10(b))
, close-up (Fig. 1θ (C)) each state of the lens,
Also, stray light can be prevented even during switching.

According to the above embodiment, the driven side rotating member (
The wide-angle lens sub-optical system block 41 and the wedge lens block 45) can be rotated by a predetermined angle by driving the drive-side rotating members (front lens block 1 and rear lens block 2) that have the photographic optical system, and the viewfinder optical system Since there is no need for a special transmission mechanism for rotating the rotating member (driven rotating member), the movable lens of the finder optical system can be switched without increasing the number of parts.

Further, according to the above embodiment, based on the drive of the lens front block 1 as a driving side rotating member, the gear portion 1e and the wide angle con gear 42 as a driving gear engage with each other, so that the front lens block 1 as a driven side rotating member is rotated by a predetermined angle. After the wide-angle converter sub-optical system block 41 is rotated and the converter lens is moved to a predetermined position, the front lens block l
As for the pressing as a cam part, the claw part ih comes into contact with the wide-angle con gear 42, so the wide-angle con sub-optical system block 4
1 can be effectively prevented from rotating in reverse.

Therefore, the converter lens for the finder optical system can be reliably moved to a predetermined position and can be reliably held at that position.

Moreover, since the operating amount of the wide-angle con sub-optical system block 41 is determined by the fraction of the wide-angle con gear 42, there is no need to correlate it with the operating amount of the front lens block 1 or to provide a separate speed-up mechanism. In addition, the above lens front block 1
The cam portion 1h of the wide-angle lens sub-optical system block 4!
can effectively prevent reverse rotation of the wide-angle lens sub-optical system block 41 and the lens front block l.
Even if the rotational operation is repeated, the meshing between the wide-angle con gear 42 that drives the wide-angle con sub-optical system block 41 and the gear portion 1e of the front lens block l is less likely to become misaligned.

Further, according to the above embodiment, based on the drive of the rear lens block 2 as a drive-side rotating member, the gear portion 2e
The wedge lens block 45 is rotated by a predetermined angle with the wedge gear 46 serving as a driving gear, and before the converter lens is moved to a predetermined position, the rear lens block 2 is rotated by a predetermined angle. Since the claw portion 2h contacts the wedge gear 46 when pressed as a cam portion, rotation of the wedge lens block 45 in the rotational direction can be effectively prevented. Therefore, when rotating the finder optical system converter lens to a predetermined position, before rotationally driving,
It is possible to effectively prevent the wedge lens block 45 from erroneously starting to rotate, and the rotation of the block 45, that is, the movement of the converter lens, can be performed more accurately and reliably using the wedge lens. Further, since the cam portion 2h of the rear lens block 2 can prevent the wedge lens block 45 from rotating before the rotation operation by a predetermined angle, the rotation operation between the wedge lens block 45 and the lens rear block 2 is repeatedly performed. Even if
The engagement between the wedge lens block 45 and the gear portion 2e of the rear lens block 2 is less likely to become misaligned.

Note that the present invention is not limited to the above embodiments,
It can be implemented in various other ways. For example, each cam part 1h, 2 of the lens front block l and the lens rear block 2
h does not come into contact with the wide-angle con gear 42 and the wedge gear 46, but rather with the wide-angle con sub-optical system block 4.
1 and the wedge lens block 45 to prevent the reverse rotation of the front lens block 1 and the rotation of the rear lens block 2 before a predetermined rotation, respectively.

[Brief explanation of the drawing]

FIGS. 1(a) to 1(e) are plan views of an electronic still camera equipped with a variable magnification mechanism according to an embodiment of the present invention, respectively; FIG.
Front view, bottom view, left side view and right side view, Figure 1 (r)
2 is an explanatory diagram showing a drive system provided in the still camera, and FIGS. 2(a) to 2(c) are explanatory diagrams showing the states of a wide-angle lens, a telephoto lens, and a close-up lens, respectively.
Fig. 3 is a diagram showing the photographing distance with each lens and the screen ratio when photographing a person, Fig. 4 (a) is a cross-sectional view of the main part showing the lens switching drive mechanism, Fig. 4 (b), ( d), (f)
, (h), (D, (1) C) are explanatory diagrams showing the operation of the front lens block, respectively, and Fig. 4 (c), (e), (g).
, (i), (k), and (m) are explanatory diagrams showing the operation of the rear lens block, respectively, FIG. 5(a) is a pattern diagram of the pattern board of the lens state detection means, and FIG. 5(b)
6(a) to 6(d) are explanatory diagrams showing the barrier opening and closing operations, respectively. Explanatory diagrams of the mechanism, FIGS. 7(a) and (b) are respectively a front view of a partially toothed gear and a front view when a built-up part is formed on the gear, and FIGS. 8(a) and (b) are respectively An explanatory diagram of the finder switching operation in a wide-angle lens, Fig. 8 (c)
), (d) are respectively explanatory diagrams of the finder switching operation in a telephoto lens, FIG. 8(e) and (D are respectively explanatory diagrams of the finder switching operation in a close-up lens,
FIGS. 8(g) to (i) are explanatory diagrams of the mechanism that performs the finder switching operation, FIGS. 9(a) to (d) are explanatory diagrams of the operation of the switching prevention mechanism, respectively, and FIG. 9(e) 10(a) to (c) are perspective views showing the installation state of the switching prevention spring.
) are explanatory diagrams showing the stray light blocking mechanism, Fig. 2(a),
11B is a flowchart of the lens switching operation, and FIG. 11C is a flowchart of the barrier opening/closing operation. l... Lens front block, Ia, Ib... Main optical system, lk, ILIm... Stray light prevention wall, 2... Lens back block, 2c... Sub optical system, 2, 2Q...・Stray light prevention wall, 3...Telephoto switch, 4...Close-up switch, 5...Release switch, 6...Camera microcomputer, 7...Motor,...Reduction gear, 9...
- Sun gear, 10... Planet gear, 11... Lens switching gear A112... Lens state detection means, 13...
Lens switching gear B, 14... Lens switching gear C115
...Lens switching gear C゛, I6...Snap spring A117...Snap spring B, 18...
Switching prevention claw A119... Switching prevention spring Al2O
...Switching prevention claw B, 21...Switching prevention spring B
, 22...Lens rotation axis, 23...Lens positioning A, 24...Lens positioning B125...Imaging element, 40...Finder part, 41...Wide-angle lens sub-optical system block, 42 ... wide angle con gear, 43... wide angle con spring, 44... wide angle con stopper, 45
...Wedge lens block, 46...Wedge gear,
47... Wedge spring, 48... Wedge stopper, 51... Barrier drive gear, 52... Barrier state detection means, 53... Barrier drive lever, 54...
Barrier drive connecting plate, 55...barrier spring A15
6... Barrier spring B157... Barrier drive lever B158... Lens barrier, 59... Barrier guide, 70... Flash, 71... DC power supply, 80
...Photometry section, 90...Main switch, lot...
・Drive side gear 1. I Ola, l O2a - built-up part, 101b. 102 b-...1st tooth, l 01c, I O2cm
Second tooth, 102... Driven side gear ■, 102d...
Notch. Patent Applicant Minolta Camera Co., Ltd. Agent Patent Attorney: Mr. Maeda and 2 others Figure 1 (0) Figure 1 (b) Figure 1 (C) Figure 1 (d) Figure 1 (el Figure 1) fl Figure 2 (C1-++++++++ Figure 4 (1)
)? Figure 4 (C1) Figure 4 (d) Figure 4 Tel Figure 4 ffl Figure 4 (9) Figure 4 (h) Figure 4 (1) Figure 4 (j+ Figure 4 (kl) Figure 4 (i) Figure 4 (+711 Figure 6 (0) Figure 6 (b) Figure 6 (C) Figure 6 (d) Figure 8 (0) Figure 8 (b) Figure 8 ( c) Figure 8(d)

Claims (3)

[Claims] (1) A drive-side rotating member (1) connected to a photographing optical system and having a partially formed gear part (1e);
A driven side rotating member driving gear (42) that can mesh with the gear portion (1e) of the driving side rotating member (1), and a moving lens for a finder optical system, and the driving gear (
42) and a driven side rotating member (41) which is rotationally driven by the rotation of the driving side rotating member (1) via the driving gear (42), the driving side rotating member (1) , the driven side rotating member (41) is rotated by a predetermined angle by the meshing of the gear portion (1e) and the drive gear (42), and the camera is changed to move the movable lens to a predetermined position. The driven side rotating member (41) after the predetermined angle rotation operation is
) or a cam part (1f) that comes into contact with the driving gear (42) to prevent reverse rotation of the driven rotating member (41) is continuous with the gear part (1e) of the driving rotating member (1). A variable magnification mechanism for a camera, characterized in that the variable magnification mechanism is formed by (2) a drive-side rotating member (2) connected to the photographing optical system and having a partially formed gear part (2e);
A driven side rotating member driving gear (46) that can mesh with the gear portion (2e) of the driving side rotating member (2), and a moving lens for a finder optical system, and the driving gear (
46) and a driven side rotating member (45) that is rotationally driven via the drive gear (46) by rotation of the driving side rotating member (2), the driving side rotating member (2) , the driven side rotating member (45) is rotated by a predetermined angle by the meshing of the gear portion (2e) and the drive gear (46), and the camera is changed to move the movable lens to a predetermined position. As a double mechanism, the driven side rotating member (45
) or a cam portion (2f) that comes into contact with the drive gear (46) to prevent rotation of the driven side rotation member (45) is connected to the gear portion (2e) of the drive side rotation member (2). A variable magnification mechanism for a camera, characterized in that the variable magnification mechanism is configured to form a (3) The drive gear (42, 46) has a rotation center that is the same as the rotation center of the driven rotation member (41, 45), and While connected by spring members (43, 47), the rotation angle of the drive gear (42, 46) is smaller than the rotation angle of the driven side rotation member (41, 45), and the drive gear (4
2, 46) rotates by a predetermined angle, the driven side rotating member (
41, 45) charge the spring members (43, 47) to position the drive gears (42, 46), and also keep the driven rotating members (41, 45) from overcharging. 3. A variable magnification mechanism for a camera according to claim 1 or 2, wherein the portions (1h, 2h) are formed on the cam portions (1f, 2f) of the drive-side rotating members (1, 2).