JPS63269138A - Focal distance switching type camera - Google Patents

Abstract

PURPOSE:To use the driving force of a motor as the setting of a focusing member which travels with the energization of a spring and to simplify the structure of a movable barrel by incorporating the motor for moving of the movable barrel in the movable barrel. CONSTITUTION:A lens 3 for adjusting a focus, the focusing member 18 which is made to travel in order to locate the lens and a focus member setting mechanism which sets the traveled focusing member 18 in an initial position are respectively provided in the movable barrel 4 and also a movable barrel moving mechanism and a motor which drives the mechanism are provided in the movable barrel 4. And when the motor is normally rotated, the focusing member setting mechanism is made to actuate and when it is inversely rotated the movable barrel moving mechanism is made to actuate. Thus, the structure of the movable barrel can be simplified by effectively utilizing the motor in the movable barrel.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a focal length switching type camera, and more particularly to a camera in which a focus adjustment mechanism is built into a movable barrel that is moved when switching the focal length.

[Conventional technology]

2. Description of the Related Art Some recent compact cameras are known to be able to take pictures at either telephoto or wide angle by switching the focal length of the photographic lens. In such a focal length switching type camera, at least a portion of the photographic lens is held in a movable barrel, and during telephoto shooting, the lens is extended in the optical axis direction to extend the focal length. There are also models that use a motor to move this movable barrel between the wide-angle shooting position and the telephoto shooting position.
It is designed to prevent the movable barrel from being stopped between the two positions and to improve operability when changing the focal length.

In addition, autofocus devices are also used in such focal length switching cameras, and generally a part of the photographic lens held in a movable barrel is positioned according to a distance measurement signal output from an automatic distance measurement device. to adjust the focus. Therefore, a mechanism for positioning a part of the photographic lens to a focus position is required within the movable barrel, and for example, a stepping motor is built into the movable barrel to adjust the focus.

(Problems to be Solved by the Invention) However, when attempting to directly rotate a cam ring etc. using a stepping motor built into a movable tube and thereby control the extension of a lens for focus adjustment, the amount of extension of the lens becomes large. The problem is that the stepping motor is controlled by the distance measurement signal obtained from the distance measurement device and is used only for positioning the lens for focus adjustment.
This problem can be solved by moving the focus member, which is driven by a spring, toward the position obtained in this way, and using the movement of the focus member to move the focus adjustment lens to the in-focus position. However, when such a configuration is adopted, a mechanism for charging the spring must be provided inside the movable barrel each time an image is taken, which further complicates the structure inside the movable barrel.

The present invention was made in view of this background, and by incorporating a motor for moving the movable tube into the movable tube,
It is an object of the present invention to provide a focal length switching type camera in which the driving force of this motor is also used for setting a focus member that runs by spring bias, and the structure of the movable barrel is simplified.

[Means for solving problems]

In order to achieve the above object, the present invention provides a focus adjustment lens, a focus member that is driven to position the lens, and a focus member setting mechanism that sets the driven focus member to an initial position. In addition to being provided inside the movable tube, a movable tube moving mechanism and a motor for driving the same are also provided in the movable tube. and,
When the motor is rotated in the normal direction, the focus member setting mechanism is operated, and when the motor is rotated in the reverse direction, the movable cylinder moving mechanism is operated.

[Effect]

According to the above configuration, when photographing is completed, the focus member setting mechanism is activated by normal rotation of the motor, and the focus plate, which is driven by the spring bias, is set to the initial position, and preparation for the next photographing is completed. Further, when an operation for switching the focal length is performed, the movable barrel moving mechanism is activated by reversing the motor, and the movable barrel moves in the optical axis direction to perform the focal length switching.

An embodiment of the present invention will be described below with reference to the drawings.

〔Example〕

In FIG. 2 showing the appearance of a camera using the present invention, a fixed barrel 2 is formed on the front surface of a body l, and a movable barrel 4 holding a photographing lens 3 is supported in the fixed barrel 2 so as to be movable in the direction of the optical axis 3a. has been done. A knob 5 for changing the focal length is provided on the side surface of the fixed barrel 2, and by operating the knob 5, the movable barrel 4 is moved back and forth and set to a mode position for either wide-angle photography or telephoto photography.

The photographing lens 3 is movable in the direction of the optical axis 3a relative to the movable barrel 4 for focus adjustment. In order to adjust the focus of the photographic lens 3, a light projecting section 6 and a light receiving section 7, which constitute an automatic distance measuring device, are provided at the upper front surface of the body 1. As schematically shown in FIG. 3, the light projecting section 6 and the light receiving section 7 are arranged with a base line length apart. The light projecting unit 6 includes a light projecting lens 6a and a light emitting diode 6b that emits near-infrared light, and emits a distance measuring light beam toward the subject when the shutter button 9 is pressed halfway.

The light receiving section 7 includes a filter 7a that cuts visible light and transmits near-infrared light, a light receiving lens 7b, and a light receiving element 7C. The light-receiving element 7C is movable along the focal plane of the light-receiving lens 7b, and by moving it, the light-receiving optical axis of the light-receiving lens 7b can be changed. Then, when the light beam is irradiated from the light projector 6 to the subject, the light receiving element 7c is moved and the position of the light receiving element 7c where the reflected light from the subject is maximized is detected, thereby establishing a correlation with the subject distance. A ranging signal can be obtained.

4 and 5, which schematically show the internal structure of the lens barrel, a fixed frame 10 fixed to the body 1 together with the fixed barrel 2 in FIG. 2 has a movable frame 1 that moves together with the movable barrel 4.
2 is retained. A guide bar 13 fixed to the movable frame 12 engages with a slot 14 of the fixed barrel 10, thereby guiding the movement of the movable frame 12 in the direction of the optical axis 3a.

The movable frame 12 holds a lens barrel 15 in which a photographic lens 3 is incorporated. This lens barrel 15 has a pair of pins 15a extending on both sides, and these pins 15a connect to the movable frame 12.
is engaged with the slot 16 of. Pin 15a and movable frame 1
A spring 17 is applied between the lens barrel 15 and the lens barrel 15, which urges the lens barrel 15 in the backward direction. In addition, the pin 1
One side of the lens barrel 15 passes through the slot 16 and is in sliding contact with the cam surface "18a" of the focus plate 18, which is attached to the side surface of the movable frame 12 so as to be able to rise and fall freely.Thereby, the position of the lens barrel 15 on the optical axis is , can be determined according to the vertical position of the focus plate during the day.

The movable frame 12 is further provided with a shutter unit 20 and holds a lens barrel 22 incorporating a conversion lens 21.

A pin 22 a implanted in the lens barrel 22 passes through a slot 23 vertically provided in the movable frame 12 and engages with a cam groove 24 formed in the fixed frame 10 . When the movable frame 12 is moved to the forward extended position, the lens barrel 22 is lowered by the pin 22a and the cam groove 24, and is moved to a position where it shares the optical axis 3a of the photographic lens 3. Movable frame 12
A movable tube moving mechanism 25 is attached to the bottom of the tube via a bracket 26. This movable cylinder moving mechanism 25 is
This is for moving the movable frame 12 in the optical axis direction according to the set position of the knob 5. Further, the fixed frame IO is provided with microswitches 27 and 28, which are turned on by a protrusion 29 integrally provided on the movable frame 12 when the movable frame 12 moves to the forward position and the backward position, respectively.

Specifically, as shown in FIG. 1, the movable cylinder moving mechanism 25 including the set motor 30 is driven by a drive gear 33 that rotates around a shaft 32 provided on the bracket 26. Interlocking gear 3
4. Set plate 35. A planetary gear 37 that transmits the rotation of the switching gear plate 36 and the drive gear 33 to the interlocking gear 34.
38. The set plate 35 rotates together with the interlocking gear 34 when it rotates in the solid line direction, but rotation in the opposite direction is prohibited by the clutch pawl 43.

Furthermore, when the drive gear 33 rotates in the direction of the solid line, the planetary gears 39 and 40 rotate in the same position around the rotating shaft 41, but when the drive gear 33 rotates in the direction of the broken line, they rotate in the direction of the broken line. Drive gear 33. It performs planetary motion around the interlocking gear 34. In addition, the planetary gear 39
．． Set motor 3 so as not to obstruct the planetary motion of 40
0 is assembled inside the planetary gears 39 and 40, and the lead wire is drawn out through the shaft 32.

A clutch pawl 44 also acts on the switching plate 36, and its rotation in the counterclockwise direction is prohibited. Further, a pin 45 is implanted in the switching plate 36, and a roller 46 is rotatably attached to the pin 45.

An operation plate 48 is integrated with the focal length switching knob 5, and is raised and lowered relative to the fixed frame 10 by operating the knob 5. The movement of the operation plate 48 is guided by a guide roller 49 and positioned by a click ball 50. Arms 48a and 48b are formed on the operation plate 48.

Then, depending on the set position of the knob 5, the arm 48a
, 48b emerges within the rotation locus of the roller 46 provided on the switching plate 42. Further, the set position of the knob 5 can be electrically detected by setting one of the contacts 52a and 52b to ground potential using a conductive piece 51 fixed to the switching plate 48.

A lens drive mechanism 60 for setting the lens barrel 15 holding the close-up lens 3 to a focusing position includes the focus plate 18 which is attached to the movable frame 12 via a guide pin 61 and a slot 62 so as to be able to move up and down, and It includes a stepping motor 66 attached to the fixed frame 1O, and an interlocking plate 63 and a control plate 64, which are also attached to the fixed frame 10 so as to be able to rise and fall by bin-slot engagement. A rack 63a is formed on the lower side of the interlocking plate 63, and a pinion 67 fixed to the drive shaft of the stepping motor 66 is engaged with the rack 63a. Further, a pin 63b is implanted in the lower part of the interlocking plate 63, and an arm 63c is integrally formed in the upper part.

Similar to the interlocking plate 63, the control plate 64 is movably attached to the fixed frame 10 by pin-slot engagement. This control plate 64 is formed with a number of locking claws 64a that corresponds to the number of stages of the focusing position, and furthermore, a control arm 64b that projects forward is integrated into the upper part. Further, a spring 6 is provided between the control plate 64 and the pin 63b of the interlocking plate 63.
8 is applied and the interlocking plate 63 is raised, the control plate 64 is also raised accordingly.

A lock lever 65 is engaged with and disengaged from a locking pawl 64a formed on the control plate 64. This lock lever 65 is biased clockwise by a spring, and under normal conditions, a combination type magnet 70 moves the lock lever 65 toward the locking claw 6 as shown in the figure.
4a. The moment the magnet 70 is energized, it engages with the locking claw 64a due to the bias of the spring.

A pin 18b is implanted on one surface of the focus plate 18. This pin 18b is connected to the focus plate 18 by the spring 7.
In the process of moving upward due to the biasing force 1, the focus plate 18 comes into contact with the control arm 64b, thereby restricting the focus plate 18 from rising. A pin 15a provided on the lens barrel 15 is in sliding contact with the cam surface 18a. And the focus plate 18
By rising, the lens barrel 15 is extended along the optical axis 3a. Note that a locking portion 18c is formed at the upper end of the focus plate 18, and this locking portion 18c is formed in the normal state.
By engaging the locking lever 73 with the lock lever 73, the focus plate 18 is locked from rising. Further, a set portion 18d is provided in the lower part of the focus plate 18 as a semi-circular hollowed out portion, and a set pin 74 implanted in the set gear 34 faces the set portion 18d.

The upper end of the interlocking plate 63 is in contact with a 7-shaped distance measuring lever 75 that is pivoted to the fixed frame 10 and biased counterclockwise. The light-receiving element 7c (see FIG. 3) is fixed to the other arm of the distance-measuring lever 75 so as to receive the reflected light from the subject that has passed through the light-receiving lens 7b.

In FIG. 6, which shows an example of a circuit for controlling the drive of the set motor 30, a driver 80 starts and stops the set motor 3° and controls the rotational direction. The driver 80 receives signals from the game console G4 and the shutter device 81. When the "H" signal is supplied from the shutter device 81, the set motor 3° rotates forward, and a high level signal (
Hereinafter, when r) (referred to as J signal) is supplied, the rotation is reversed. Furthermore, when the signal becomes "L" in both cases, the set motor 30 stops. The shutter device 81 outputs an "H" signal upon receiving the shutter operation completion signal, and outputs an "L" signal when the set plate 35 has made exactly one rotation.

Of course, the set plate 35 may be provided with a contact point for detecting one rotation thereof, and the drive of the set motor 30 may be stopped by an electric signal from the contact point.

Microswitch 27, 28. AND gate GL, NAND gate) G2, and D flip-flop circuit (hereinafter referred to as
FF) 82 is provided to generate a stop signal when the set motor 30 is being rotated in reverse. In other words, when the "H" signal is output from the Nant gate G2 to the clock terminal of the FF82, the ζ terminal output changes from the "H" signal to the "L" signal, and the output of the AND gate G4 becomes "L" and the motor starts. Stop 30. The microswitches 27 and 28 are turned on when the movable frame 12 finishes moving to the telephoto shooting position and the wide-angle shooting position, and at the moment they are turned on, a pulse-shaped "L" is sent to the input end of the Nando Game) G2.
supply the signal. Further, the FF 80 is reset when the rH signal is supplied from the AND gate Gl to the reset terminal, and the output from the ζ terminal changes from "L" to rHJ.

The output of the above-mentioned computer game) Gl changes depending on the connection between the conductive piece 51 fixed to the operation plate 48 and the contact plates 52a and 52b. That is, the conductive piece 51 is the contact plate 52a,
52b, when connected to one of the
Gl outputs an "L" signal and connects the conductive piece 51 to the contact plate 52a.
, 52b, "H" is output to both AND gates G3 and G4, and at the same time, "H" appears at the output terminal of AND gate G1 to reset the FF 82.

The effects of the above configuration are as follows. When the wide-angle shooting mode is set, as shown in FIG. 1, the operation plate 48 is in a raised position, the arm 48b is retracted from the rotational trajectory of the roller 46, and the conductive piece 51 is located at the contact point. 52a. The movable frame 12 is shown in FIGS. 4 and 5.
As shown in the figure, it remains in the retracted position, and the microswitch 28 is turned on. Of course, the movable cylinder 4 is also in the retracted position shown by the solid line in FIG.

When the shutter button 9 is pressed to the first stage, the light emitting diode 6b lights up, and a distance measuring light beam is irradiated onto the subject via the projection lens 6a. At the same time, the stepping motor 66 is driven, and the interlocking plate 63 is raised via the pinion 67 and the rack 63a. As the interlocking plate 63 rises, the distance measuring lever 75 rotates clockwise, and the light receiving element 7C moves behind the light receiving lens 7b in the direction shown by the two-dot chain line in FIG. 3, moving the light receiving optical axis far away. You will now be able to swing from the distance side to the short distance side. Furthermore, as the interlocking plate 63 is raised, the control plate 64 also follows and rises due to the bias of the spring 68.

While the light receiving optical axis is being swung by the movement of the light receiving element 7C, the magnet 70 is energized at the time when the reflected light from the subject is detected by the light receiving element 7C. As a result, the lock lever 65 rotates to the right and engages with the locking pawl 64a of the control plate 64 which is in the middle of being raised, thereby positioning the control plate 64. That is, the control board 64 is positioned in accordance with the timing at which the distance measurement signal is obtained in the process of moving the light receiving element 7C.

As the stepping motor 66 further rotates, the arm 63a integrated with the upper end of the interlocking plate 63 pushes up the free end of the locking lever 73 and rotates it counterclockwise. As a result, the locking of the focus plate 18 is released, and the focus plate 18 is raised by the bias of the spring 71. Then, pin 1 installed on the focus plate 18
The focus plate 18 is positioned by the contact between the focus plate 8b and the control arm 64b. In this way, focus plate 1
8 rises to the position determined by the control arm 64b, the pin 15 in sliding contact with the cam surface 18a
The lens barrel 15 is extended through a, and the focus of the photographic lens 3 is adjusted.

In the focus adjustment operation described above, the driving source for extending the lens barrel 15 is the spring 71, and the stepping motor 66
The driving load of the interlocking plate 63 and the distance measuring lever 75 is added to this, making it very light. Therefore, the stepping motor 66 is not required to have a high output torque, and the stepping motor 66 rotates the distance measuring lever 75 with high precision in accordance with the number of input drive pulses.

After the photograph is taken, rH is sent from the shutter device 81 to the driver 80.
, signals are supplied, the set motor 30 rotates in the normal direction, and each gear rotates in the direction of the solid line as shown in FIG. When the set plate 35 is rotated once in the solid line direction, the set pin 74 is rotated 360 degrees clockwise. In the process of rotating the set pin 74 in this manner, the focus plate 18 whose raised position is regulated by the control arm 64b is pushed down to the lowest position, and at that point the locking lever 73 engages with the locking portion 18c. focus plate 18
is stopped in the lowered position. When the set plate 35 continues to rotate the remaining 180 degrees, the set pin 74 is moved to the top within the set portion lBd, as shown in FIG.
The set motor 30 stops.

After the set motor 30 has stopped, the stepping motor 6
6 is reversed and returned to the initial position. As a result, the interlocking plate 63. The control plate 64 descends to the initial position shown in FIG. 1 and stops, and the distance measuring lever 75 also moves back to the initial position. Furthermore, when the shutter operation is completed, the power to the magnet 70 is cut off, so when the control plate 64 is lowered and the lock lever 65 is turned left by the locking pawl 64a, the permanent magnet of the combination type magnet 70 is turned off. attracts the lock lever 65 and holds it in the illustrated position, and each member is returned to its initial position.

When shooting in telephoto shooting mode, move knob 5 to the index “
Push down so that it aligns with "T". In this way, the operation panel 4
8 is lowered from the position shown by the two-dot chain line to the position shown by the solid line in FIG. When the conductive piece 51 is separated from the contact 52a during this contact switching, the contact 52a also reaches a predetermined potential level, and the antagonal
) The rH signal is input to both input terminals of Gl. and,
FF from AND gate Gl) (FF by J signal output
When 82 is reset, its ζ terminal output changes from rl, J to rH, and the output terminal of AND gate G4 receives r)(
A J signal appears. r HJ from this AND gate G4
When the driver 80 is activated by the signal, the set motor 3
0 is reversed, and the drive gear 33 and the subsequent gears begin to rotate in the direction of the broken line in FIG.

However, since the set plate 35 is prohibited from rotating counterclockwise by the clasp claw 43, the set motor 3
The rotation in the reverse direction of 0 acts to cause the planetary gears 37, 38 to move planetarily along with the rotating shaft 41. The planet gears 37 and 38 are rotated by the set motor 30 and rotate clockwise around the drive gear 33. This planetary motion rotates the switching plate 36 about the shaft 32 in the direction of the dashed arrow.

By the way, when the telephoto shooting mode is set, the operation panel 48
has been moved to the position shown by the solid line in FIG. 7(A), and the arm 48b is now exposed within the rotation locus of the roller 46 rotatably supported by the switching plate 36. When the switching plate 36 rotates clockwise in this state,\
As shown in FIG. 7(B), the roller 46 is connected to the arm 48.
b. Then, as the set motor 30 continues to rotate further, as shown in FIG.
As shown in FIG. 2, due to the reaction force of the roller 46 pressing the arm 48b, the switching plate 36, together with the shaft 32, is pushed to the left from the position shown by the two-dot chain line.

The movable cylinder moving mechanism 25 including the switching plate 36 moves between the movable frame 1
Since it is held on the bottom surface of switch plate 3,
6 moves to the left, the movable frame 12 moves toward the optical axis 3.
It will be moved forward along a. When the movable frame 12 moves forward, the lens barrel 22 holding the conversion lens 21 moves into the rear of the photographic lens 3.Then, when the movable frame 12 moves forward a predetermined distance, the protrusion 29
This turns on the microswitch 27.

When the microswitch 27 is turned on, the capacitor 27a
The terminal voltage momentarily becomes ground potential (Nando game)
An “L” signal is supplied to the input terminal of G2, and the Nant gate G
An "H" signal appears at the output terminal of 2. The FF 82 is set by the rise of the rH signal from the Nant gate G2, and the output of the ζ terminal is switched from the rH signal to the "L" signal. Since the output of this ζ terminal is supplied to one input terminal of the controller G4, the moment the microswitch 27 is turned on as described above, the output of the controller G4 becomes "L" and the set motor 30 is driven. stops.

Note that, after the terminal voltage of the capacitor 27a momentarily reaches the ground potential as described above, it rises to a predetermined voltage level ("H" signal level) as the capacitor 27a is charged.

When the set motor 30 stops, the photographing lens 3 is extended and positioned together with the movable frame 12 to the telephoto photographing position, and the conversion lens 21 is also set at a predetermined position. In this way, the focal length is extended by combining the photographing lens 3 and the conversion lens 21, and telephoto photography can be performed.

As the movable frame 12 moves forward in this way, the focus plate 18 is also moved in the same direction, but the control arm 64b protruding from the control plate 64 is extended in the optical axis direction in anticipation of the amount of forward movement of the movable frame 12. , since the control arm 64b has reached the movement path of the pin 18b, the stepping motor 66. Each of the interlocking plate 63 and the control plate 64 is connected to the fixed frame 1
Even if it is provided on the 0 side, the lens barrel 15 can be set to the in-focus position by positioning the focus plate 18, as explained in the wide-angle shooting mode.

When a photograph is taken and the shutter operation is completed, the rH signal is supplied from the shutter device 81 to the driver 80. As a result, the set motor 30 rotates in the normal direction, and as described above, each gear after the drive gear 33 rotates in the direction of the solid line in FIG. 1, and the focus plate 18 is charged to the initial position by the set pin 74. Become. Also, focus plate 1
8 is charged to the initial position, the stepping motor 66 is also reversed, and the interlocking plate 63. Each of the control plates 64 is also returned to its initial position.

Knob 5 to return from telephoto shooting mode to wide-angle shooting mode
When it is aligned with the index "W", the operation plate 48 is set to the position shown in FIG. 1, that is, the position shown by the two-dot chain line in FIG. 7(A). When the conductive piece 51 separates from the contact 52b during this setting, the r HJ signal appears at the output terminal of the AND gate Gl, thereby resetting the FF 82. Then, the ζ terminal output of the FF 82 changes from an "L" signal to an "H" signal, and an "H" signal appears at the output terminal of the analogue G4, which is supplied to the driver 80. Therefore, the set motor 30 starts reverse rotation, and the switching plate 3
6 is rotated in the direction of the broken line.

As the switching plate 36 rotates in this way, the roller 46
comes into contact with the arm 48a of the switching plate 36 in the raised position from the right side and presses it. Furthermore, when the switching plate 36 is rotated by the set motor 30, due to the reaction force of the roller 48 pressing the arm 48a,
The switching plate 36 is moved together with the shaft 32 to the right, that is, in the backward direction. As a result, the movable frame 12 comes to be retreated, and the lens barrel 15 moves toward the wide-angle photographing position. Further, as the movable frame 12 retreats, the lens barrel 22' holding the conversion lens 21 is retracted upward along the cam groove 24.

When the movable frame 12 retreats by a certain amount, the protrusion 29 turns on the microswitch 28. At the moment the microswitch 28 is turned on, an "L" signal is supplied to the Nant gate G2, and an "H" signal appears at its output terminal. When the FF 82 is set by the rise of this "H" signal, a "L" signal is output to the ζ terminal, and this "L" signal causes the output of the AND gate G4 to become "L", so the driver 8
0 stops, the rotation of the set motor 30 is also stopped, and the movable frame 12 is set at the wide-angle photographing position.

In the embodiments described above, the distance measuring lever 75 is mechanically displaced by driving the stepping motor 66, and this displacement is used to perform scanning for distance measurement. As is known, the present invention is also applicable to a device that uses a CCD line sensor or the like with an electrical scanning function as the light receiving element 7c for distance measurement, and obtains a distance measurement signal without performing mechanical scanning. can do. In this case, the stepping motor 66 is driven with a number of drive pulses corresponding to the electrically detected ranging signal to position the control plate 64, thereby regulating the position of the focus plate 18. Bye.

〔Effect of the invention〕

As described above, in the focal length switching type camera of the present invention, the movable barrel that is moved for focal length switching includes a motor and a movable barrel moving mechanism driven by the motor;
A focus member setting mechanism is built in, and the movable cylinder moving mechanism and focus member setting mechanism are selectively operated by switching the rotational direction of the motor.

Therefore, in setting the focus member to the initial position while providing a mechanism for reliably setting the focus adjustment lens provided in the movable barrel to the in-focus position using the focus member running under spring bias, The motor for moving the movable tube can also be used, and the structure of the movable tube can be simplified by efficiently utilizing the motor inside the movable tube.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of essential parts showing an embodiment of the present invention. FIG. 2 is an external view of a camera using the present invention. FIG. 3 is a conceptual diagram of a photoelectric distance measuring device. FIG. 4 is a partial sectional view of the lens barrel of a camera using the present invention. 5 is a partially cutaway perspective view schematically showing the lens barrel section of FIG. 4. FIG. FIG. 6 is a block diagram of a motor drive circuit used for moving the movable frame. FIGS. 7(A), 7(B), and 7(C) are action explanatory diagrams of the progress of movement of the movable frame. 2... Fixed barrel ゛3... Photographing lens 4... Movable barrel 10... Fixed frame 12... Movable frame 15... Lens barrel 18... Focus plate 18a... Cam surface 18b... Pin 30... - Set motor 35 - Set plate 36 - Switching plate 48 - Operation plate 63 - Interlocking plate 64 - Control plate 64a - Control arm 65 - Lock lever 66 - Stepping motor.

Claims (3)

[Claims] (1) In a focal length switching type camera equipped with a movable barrel that is moved in the optical axis direction with respect to the camera body in order to switch the focal length of the photographic lens, the lens is held movably in the optical axis direction by the movable barrel. a focus adjustment lens, a focus member that runs on a movable barrel to position the lens at the focusing position, a motor provided on the movable barrel, and a focus member that runs when the motor rotates forward. a focus member setting mechanism provided on a movable tube for setting the focus member to an initial position; and a movable tube movement that moves the movable tube in the optical axis direction to switch the focal length when the motor is reversed. A focal length switching type camera characterized by being equipped with a mechanism. (2) The focus member setting mechanism has a set plate that rotates in conjunction with the normal rotation of the motor, and when this set plate rotates once, the focus member that has traveled by the spring bias is set to the spring bias. 2. The focal length switching type camera according to claim 1, wherein the camera is configured to return to its initial position by resisting the movement. (3) The movable barrel moving mechanism has a switching plate that rotates in conjunction with the reverse rotation of the motor, and the first half rotation of the switching plate advances the movable barrel, and the second half rotation moves the movable barrel backward. A focal length switching type camera according to claim 2, characterized in that the camera is configured as follows.